Removing copyUpdate to see which tests are failing in CI

Signed-off-by: Côme Chilliet <come.chilliet@nextcloud.com>

.eslintrc.js

@@ -49,5 +49,12 @@ module.exports = {
 				'@typescript-eslint/no-explicit-any': 'warn',
 			},
 		},
+		{
+			files: ['*.vue'],
+			rules: {
+				'no-irregular-whitespace': 'off',
+				'vue/no-irregular-whitespace': 'error',
+			},
+		},
 	],
 }

.github/workflows/autocheckers.yml

@@ -52,13 +52,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           extensions: bz2, ctype, curl, dom, fileinfo, gd, iconv, intl, json, libxml, mbstring, openssl, pcntl, posix, session, simplexml, xmlreader, xmlwriter, zip, zlib, sqlite, pdo_sqlite
@@ -81,13 +81,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           extensions: bz2, ctype, curl, dom, fileinfo, gd, iconv, intl, json, libxml, mbstring, openssl, pcntl, posix, session, simplexml, xmlreader, xmlwriter, zip, zlib, sqlite, pdo_sqlite

.github/workflows/block-outdated-3rdparty.yml

@@ -31,7 +31,7 @@ jobs:
               - 'version.php'
 
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
 

.github/workflows/block-unconventional-commits.yml

@@ -27,7 +27,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
 

.github/workflows/codeql.yml

@@ -32,7 +32,7 @@ jobs:
           build-mode: none
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@v5
 
     - name: Initialize CodeQL
       uses: github/codeql-action/init@v3

.github/workflows/command-compile.yml

@@ -103,7 +103,7 @@ jobs:
           key: git-repo
 
       - name: Checkout ${{ needs.init.outputs.head_ref }}
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           # Needed to allow force push later
           persist-credentials: true

.github/workflows/command-pull-3rdparty.yml

@@ -38,7 +38,7 @@ jobs:
         id: comment-branch
 
       - name: Checkout ${{ steps.comment-branch.outputs.head_ref }}
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           fetch-depth: 0

.github/workflows/cypress.yml

@@ -48,7 +48,7 @@ jobs:
           exit 1
 
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           # We need to checkout submodules for 3rdparty
@@ -102,10 +102,10 @@ jobs:
       matrix:
         # Run multiple copies of the current job in parallel
         # Please increase the number or runners as your tests suite grows (0 based index for e2e tests)
-        containers: ['component', 'setup', '0', '1', '2', '3', '4', '5', '6', '7']
+        containers: ['component', 'setup', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
         # Hack as strategy.job-total includes the component and GitHub does not allow math expressions
         # Always align this number with the total of e2e runners (max. index + 1)
-        total-containers: [8]
+        total-containers: [10]
 
     services:
       mysql:

.github/workflows/files-external-ftp.yml

@@ -55,7 +55,7 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
@@ -71,7 +71,7 @@ jobs:
           if [[ "${{ matrix.ftpd }}" == 'pure-ftpd' ]]; then docker run --name ftp -d --net host -e "PUBLICHOST=localhost" -e FTP_USER_NAME=test -e FTP_USER_PASS=test -e FTP_USER_HOME=/home/test -v /tmp/ftp:/home/test -v /tmp/ftp:/etc/pure-ftpd/passwd stilliard/pure-ftpd; fi
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -104,7 +104,7 @@ jobs:
 
       - name: Upload code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.xml
           flags: phpunit-files-external-ftp

.github/workflows/files-external-s3.yml

@@ -64,13 +64,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -104,7 +104,7 @@ jobs:
 
       - name: Upload code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.xml
           flags: phpunit-files-external-s3
@@ -152,13 +152,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -185,7 +185,7 @@ jobs:
 
       - name: Upload code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.xml
           flags: phpunit-files-external-s3

.github/workflows/files-external-sftp.yml

@@ -55,7 +55,7 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
@@ -67,7 +67,7 @@ jobs:
           if [[ '${{ matrix.sftpd }}' == 'openssh' ]]; then docker run -p 2222:22 --name sftp -d -v /tmp/sftp:/home/test atmoz/sftp 'test:test:::data'; fi
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -93,7 +93,7 @@ jobs:
 
       - name: Upload code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.xml
           flags: phpunit-files-external-sftp

.github/workflows/files-external-smb-kerberos.yml

@@ -46,13 +46,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Checkout user_saml
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           repository: nextcloud/user_saml

.github/workflows/files-external-smb.yml

@@ -60,13 +60,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -100,7 +100,7 @@ jobs:
 
       - name: Upload code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.xml
           flags: phpunit-files-external-smb

.github/workflows/files-external-webdav.yml

@@ -60,13 +60,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -97,7 +97,7 @@ jobs:
 
       - name: Upload code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.xml
           flags: phpunit-files-external-webdav

.github/workflows/files-external.yml

@@ -53,13 +53,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -85,7 +85,7 @@ jobs:
 
       - name: Upload code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.xml
           flags: phpunit-files-external-generic

.github/workflows/generate-release-changelog.yml

@@ -24,14 +24,14 @@ jobs:
           require: write
 
       - name: Checkout github_helper
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           repository: nextcloud/github_helper
           path: github_helper
 
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           path: server
@@ -47,8 +47,13 @@ jobs:
           TAGS=$(git log --decorate --oneline | egrep 'tag: ' | sed -r 's/^.+tag: ([^,\)]+)[,\)].+$/\1/g')
           CURRENT_TAG=$(echo "$TAGS" | head -n 1)
 
+          # If current tag is the first beta, we use the previous major RC1
+          if echo "$CURRENT_TAG" | grep -q 'beta1'; then
+            MAJOR=$(echo "$CURRENT_TAG" | sed -E 's/^v([0-9]+).*/\1/')
+            PREV=$((MAJOR - 1))
+            PREVIOUS_TAG="v${PREV}.0.0rc1"
           # Get the previous tag - filter pre-releases only if current tag is stable
-          if echo "$CURRENT_TAG" | grep -q 'rc\|beta\|alpha'; then
+          elif echo "$CURRENT_TAG" | grep -q 'rc\|beta\|alpha'; then
             # Current tag is pre-release, don't filter
             PREVIOUS_TAG=$(echo "$TAGS" | sed -n '2p')
           else
@@ -68,7 +73,7 @@ jobs:
          fi
 
       - name: Set up php 8.2
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 # v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 # v2.35.4
         with:
           php-version: 8.2
           coverage: none

.github/workflows/integration-dav.yml

@@ -53,13 +53,13 @@ jobs:
 
     steps:
         - name: Checkout server
-          uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+          uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
           with:
             persist-credentials: false
             submodules: true
 
         - name: Set up php ${{ matrix.php-versions }}
-          uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+          uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
           with:
             php-version: ${{ matrix.php-versions }}
             # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -70,7 +70,7 @@ jobs:
             GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
         - name: Set up Python
-          uses: LizardByte/actions/actions/setup_python@eddc8fc8b27048e25040e37e3585bd3ef9a968ed # v2025.715.25226
+          uses: LizardByte/actions/actions/setup_python@bff0a193747a3ac7930a665fc1d4b23eba583b99 # v2025.814.40518
           with:
             python-version: '2.7'
 

.github/workflows/integration-litmus.yml

@@ -52,13 +52,13 @@ jobs:
 
     steps:
         - name: Checkout server
-          uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+          uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
           with:
             persist-credentials: false
             submodules: true
 
         - name: Set up php ${{ matrix.php-versions }}
-          uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+          uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
           with:
             php-version: ${{ matrix.php-versions }}
             # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation

.github/workflows/integration-s3-primary.yml

@@ -67,13 +67,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation

.github/workflows/integration-sqlite.yml

@@ -95,14 +95,14 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Checkout Talk app
         if: ${{ matrix.test-suite == 'videoverification_features' }}
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           repository: nextcloud/spreed
@@ -111,7 +111,7 @@ jobs:
 
       - name: Checkout Activity app
         if: ${{ matrix.test-suite == 'sharing_features' }}
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           repository: nextcloud/activity
@@ -119,7 +119,7 @@ jobs:
           ref: ${{ matrix.activity-versions }}
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation

.github/workflows/lint-eslint.yml

@@ -56,7 +56,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
 

.github/workflows/lint-php-cs.yml

@@ -48,12 +48,12 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
 
       - name: Set up php8.1
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 # v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 # v2.35.4
         with:
           php-version: 8.1
           extensions: bz2, ctype, curl, dom, fileinfo, gd, iconv, intl, json, libxml, mbstring, openssl, pcntl, posix, session, simplexml, xmlreader, xmlwriter, zip, zlib, sqlite, pdo_sqlite

.github/workflows/lint-php.yml

@@ -53,12 +53,12 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 # v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 # v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           coverage: none

.github/workflows/lint-stylelint.yml

@@ -25,7 +25,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
 

.github/workflows/node-test.yml

@@ -62,7 +62,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
 
@@ -85,7 +85,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
 
@@ -106,7 +106,7 @@ jobs:
         run: npm run test:coverage --if-present
 
       - name: Collect coverage
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./coverage/lcov.info
 
@@ -125,7 +125,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
 
@@ -155,7 +155,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
 

.github/workflows/node.yml

@@ -56,7 +56,7 @@ jobs:
     name: NPM build
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
 

.github/workflows/npm-audit-fix.yml

@@ -31,7 +31,7 @@ jobs:
     steps:
       - name: Checkout
         id: checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           ref: ${{ matrix.branches }}

.github/workflows/object-storage-azure.yml

@@ -73,13 +73,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -110,7 +110,7 @@ jobs:
 
       - name: Upload code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.xml
           flags: phpunit-azure

.github/workflows/object-storage-s3.yml

@@ -74,13 +74,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -116,7 +116,7 @@ jobs:
 
       - name: Upload code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.xml
           flags: phpunit-s3

.github/workflows/object-storage-swift.yml

@@ -71,13 +71,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -106,7 +106,7 @@ jobs:
 
       - name: Upload code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.xml
           flags: phpunit-swift

.github/workflows/openapi.yml

@@ -26,12 +26,12 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
 
       - name: Set up php
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 # v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 # v2.35.4
         with:
           php-version: '8.1'
           extensions: ctype, curl, dom, fileinfo, gd, json, libxml, mbstring, openssl, pcntl, pdo, posix, session, simplexml, xml, xmlreader, xmlwriter, zip, zlib

.github/workflows/performance.yml

@@ -35,14 +35,14 @@ jobs:
           exit 1
 
       - name: Checkout server before PR
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
           ref: ${{ github.event.pull_request.base.ref }}
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 # v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 # v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           extensions: bz2, ctype, curl, dom, fileinfo, gd, iconv, intl, json, libxml, mbstring, openssl, pcntl, posix, redis, session, simplexml, xmlreader, xmlwriter, zip, zlib, sqlite, pdo_sqlite

.github/workflows/phpunit-32bits.yml

@@ -34,7 +34,7 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
@@ -45,7 +45,7 @@ jobs:
           sudo apt-get install -y ffmpeg imagemagick libmagickcore-6.q16-3-extra
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           extensions: bz2, ctype, curl, dom, fileinfo, gd, iconv, imagick, intl, json, libxml, mbstring, openssl, pcntl, posix, redis, session, simplexml, xmlreader, xmlwriter, zip, zlib, sqlite, pdo_sqlite, apcu, ldap

.github/workflows/phpunit-mariadb.yml

@@ -90,13 +90,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 # v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 # v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -129,7 +129,7 @@ jobs:
 
       - name: Upload db code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.db.xml
           flags: phpunit-mariadb

.github/workflows/phpunit-memcached.yml

@@ -72,13 +72,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -103,7 +103,7 @@ jobs:
 
       - name: Upload code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.xml
           flags: phpunit-memcached

.github/workflows/phpunit-mysql-sharding.yml

@@ -121,13 +121,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -161,7 +161,7 @@ jobs:
 
       - name: Upload db code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.db.xml
           flags: phpunit-mysql

.github/workflows/phpunit-mysql.yml

@@ -90,13 +90,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 # v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 # v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -129,7 +129,7 @@ jobs:
 
       - name: Upload db code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.db.xml
           flags: phpunit-mysql

.github/workflows/phpunit-nodb.yml

@@ -75,13 +75,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -109,7 +109,7 @@ jobs:
 
       - name: Upload nodb code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.nodb.xml
           flags: phpunit-nodb

.github/workflows/phpunit-object-store-primary.yml

@@ -72,13 +72,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           extensions: bz2, ctype, curl, dom, fileinfo, gd, iconv, intl, json, libxml, mbstring, openssl, pcntl, posix, redis, session, simplexml, xmlreader, xmlwriter, zip, zlib, sqlite, pdo_sqlite

.github/workflows/phpunit-oci.yml

@@ -101,13 +101,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 # v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 # v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -133,7 +133,7 @@ jobs:
 
       - name: Upload db code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.db.xml
           flags: phpunit-oci

.github/workflows/phpunit-pgsql.yml

@@ -90,13 +90,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 # v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 # v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -124,7 +124,7 @@ jobs:
 
       - name: Upload db code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.db.xml
           flags: phpunit-postgres

.github/workflows/phpunit-sqlite.yml

@@ -75,13 +75,13 @@ jobs:
 
     steps:
       - name: Checkout server
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php ${{ matrix.php-versions }}
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 # v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 # v2.35.4
         with:
           php-version: ${{ matrix.php-versions }}
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation
@@ -110,7 +110,7 @@ jobs:
 
       - name: Upload db code coverage
         if: ${{ !cancelled() && matrix.coverage }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           files: ./clover.db.xml
           flags: phpunit-sqlite

.github/workflows/reuse.yml

@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest-low
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
 

.github/workflows/static-code-analysis.yml

@@ -28,13 +28,13 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: '8.1'
           extensions: apcu,ctype,curl,dom,fileinfo,ftp,gd,imagick,intl,json,ldap,mbstring,openssl,pdo_sqlite,posix,sqlite,xml,zip
@@ -59,13 +59,13 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: '8.1'
           extensions: ctype,curl,dom,fileinfo,ftp,gd,imagick,intl,json,ldap,mbstring,openssl,pdo_sqlite,posix,sqlite,xml,zip
@@ -94,13 +94,13 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: '8.1'
           extensions: ctype,curl,dom,fileinfo,gd,imagick,intl,json,mbstring,openssl,pdo_sqlite,posix,sqlite,xml,zip
@@ -125,13 +125,13 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
         with:
           persist-credentials: false
           submodules: true
 
       - name: Set up php
-        uses: shivammathur/setup-php@ccf2c627fe61b1b4d924adfcbd19d661a18133a0 #v2.35.2
+        uses: shivammathur/setup-php@ec406be512d7077f68eed36e63f4d91bc006edc4 #v2.35.4
         with:
           php-version: '8.1'
           extensions: ctype,curl,dom,fileinfo,gd,imagick,intl,json,mbstring,openssl,pdo_sqlite,posix,sqlite,xml,zip

.github/workflows/update-cacert-bundle.yml

@@ -22,7 +22,7 @@ jobs:
     name: update-ca-certificate-bundle-${{ matrix.branches }}
 
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           ref: ${{ matrix.branches }}

.github/workflows/update-code-signing-crl.yml

@@ -22,7 +22,7 @@ jobs:
     name: update-code-signing-crl-${{ matrix.branches }}
 
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           ref: ${{ matrix.branches }}

.github/workflows/update-min-supported-desktop.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest-low
 
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
           submodules: true

.htaccess

@@ -60,7 +60,6 @@
 </IfModule>
 
 <IfModule mod_php.c>
-  php_value mbstring.func_overload 0
   php_value default_charset 'UTF-8'
   php_value output_buffering 0
   <IfModule mod_env.c>

.user.ini

@@ -1,7 +1,9 @@
 ; SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
 ; SPDX-FileCopyrightText: 2014-2016 ownCloud, Inc.
 ; SPDX-License-Identifier: AGPL-3.0-only
-mbstring.func_overload=0
+;
+; NOTE: PHP caches this file for 300 seconds by default
+;
 always_populate_raw_post_data=-1
 default_charset='UTF-8'
 output_buffering=0

__mocks__/@nextcloud/axios.ts

@@ -14,4 +14,5 @@ export default {
 	get: async () => ({ status: 200, data: {} }),
 	delete: async () => ({ status: 200, data: {} }),
 	post: async () => ({ status: 200, data: {} }),
+	head: async () => ({ status: 200, data: {} }),
 }

__tests__/mock-window.js

@@ -2,7 +2,13 @@
  * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
  * SPDX-License-Identifier: AGPL-3.0-or-later
  */
-window.OC = { ...window.OC }
+window.OC = {
+	...window.OC,
+	config: {
+		version: '32.0.0',
+		...(window.OC?.config ?? {}),
+	},
+}
 window.OCA = { ...window.OCA }
 window.OCP = { ...window.OCP }
 

apps/cloud_federation_api/lib/Capabilities.php

@@ -9,26 +9,14 @@ declare(strict_types=1);
 
 namespace OCA\CloudFederationAPI;
 
-use NCU\Security\Signature\Exceptions\IdentityNotFoundException;
-use NCU\Security\Signature\Exceptions\SignatoryException;
-use OC\OCM\OCMSignatoryManager;
+use OC\OCM\OCMDiscoveryService;
 use OCP\Capabilities\ICapability;
 use OCP\Capabilities\IInitialStateExcludedCapability;
-use OCP\IAppConfig;
-use OCP\IURLGenerator;
 use OCP\OCM\Exceptions\OCMArgumentException;
-use OCP\OCM\ICapabilityAwareOCMProvider;
-use Psr\Log\LoggerInterface;
 
 class Capabilities implements ICapability, IInitialStateExcludedCapability {
-	public const API_VERSION = '1.1.0';
-
 	public function __construct(
-		private IURLGenerator $urlGenerator,
-		private IAppConfig $appConfig,
-		private ICapabilityAwareOCMProvider $provider,
-		private readonly OCMSignatoryManager $ocmSignatoryManager,
-		private readonly LoggerInterface $logger,
+		private readonly OCMDiscoveryService $ocmDiscoveryService,
 	) {
 	}
 
@@ -39,40 +27,7 @@ class Capabilities implements ICapability, IInitialStateExcludedCapability {
 	 * @throws OCMArgumentException
 	 */
 	public function getCapabilities() {
-		$url = $this->urlGenerator->linkToRouteAbsolute('cloud_federation_api.requesthandlercontroller.addShare');
-		$pos = strrpos($url, '/');
-		if ($pos === false) {
-			throw new OCMArgumentException('generated route should contain a slash character');
-		}
-
-		$this->provider->setEnabled(true);
-		$this->provider->setApiVersion(self::API_VERSION);
-		$this->provider->setCapabilities(['/invite-accepted', '/notifications', '/shares']);
-
-		$this->provider->setEndPoint(substr($url, 0, $pos));
-
-		$resource = $this->provider->createNewResourceType();
-		$resource->setName('file')
-			->setShareTypes(['user', 'group'])
-			->setProtocols(['webdav' => '/public.php/webdav/']);
-
-		$this->provider->addResourceType($resource);
-
-		// Adding a public key to the ocm discovery
-		try {
-			if (!$this->appConfig->getValueBool('core', OCMSignatoryManager::APPCONFIG_SIGN_DISABLED, lazy: true)) {
-				/**
-				 * @experimental 31.0.0
-				 * @psalm-suppress UndefinedInterfaceMethod
-				 */
-				$this->provider->setSignatory($this->ocmSignatoryManager->getLocalSignatory());
-			} else {
-				$this->logger->debug('ocm public key feature disabled');
-			}
-		} catch (SignatoryException|IdentityNotFoundException $e) {
-			$this->logger->warning('cannot generate local signatory', ['exception' => $e]);
-		}
-
-		return ['ocm' => $this->provider->jsonSerialize()];
+		$provider = $this->ocmDiscoveryService->getLocalOCMProvider(false);
+		return ['ocm' => $provider->jsonSerialize()];
 	}
 }

apps/comments/l10n/be.js

@@ -0,0 +1,36 @@
+OC.L10N.register(
+    "comments",
+    {
+    "Comments" : "Каментарыі",
+    "You commented" : "Вы пракаментавалі",
+    "{author} commented" : "{author} пракаментаваў(-ла)",
+    "You commented on %1$s" : "Вы пракаментавалі %1$s",
+    "You commented on {file}" : "Вы пракаментавалі {file}",
+    "%1$s commented on %2$s" : "%1$s пракаментаваў(-ла) %2$s",
+    "{author} commented on {file}" : "{author} пракаментаваў(-ла) {file}",
+    "<strong>Comments</strong> for files" : "<strong>Каментарыі</strong> да файлаў",
+    "Files" : "Файлы",
+    "You were mentioned on \"{file}\", in a comment by an account that has since been deleted" : "Вас згадалі ў каментарыі да \"{file}\" з уліковага запісу, які пазней быў выдалены.",
+    "{user} mentioned you in a comment on \"{file}\"" : "{user} згадаў(-ла) вас у каментарыі да \"{file}\"",
+    "Files app plugin to add comments to files" : "Убудова праграмы Файлы для дадавання каментарыяў да файлаў",
+    "Edit comment" : "Рэдагаваць каментарый",
+    "Delete comment" : "Выдаліць каментарый",
+    "Cancel edit" : "Скасаваць рэдагаванне",
+    "New comment" : "Новы каментарый",
+    "Write a comment …" : "Напішыце каментарый …",
+    "Post comment" : "Апублікаваць каментарый",
+    "@ for mentions, : for emoji, / for smart picker" : "@ - згадкі, : - эмодзі, / - разумны выбар",
+    "Could not reload comments" : "Не ўдалося перазагрузіць каментарыі",
+    "Failed to mark comments as read" : "Не атрымалася пазначыць каментарыі як прачытаныя",
+    "Unable to load the comments list" : "Не ўдалося загрузіць спіс каментарыяў",
+    "No comments yet, start the conversation!" : "Пакуль няма каментарыяў, пачніце размову!",
+    "No more messages" : "Больш паведамленняў няма",
+    "Retry" : "Паўтарыць спробу",
+    "_1 new comment_::_{unread} new comments_" : ["1 новы каментарый","{unread} новыя каментарыі","{unread} новых каментарыяў","{unread} новых каментарыяў"],
+    "Comment" : "Каментарый",
+    "An error occurred while trying to edit the comment" : "Падчас спробы рэдагавання каментарыя ўзнікла памылка",
+    "Comment deleted" : "Каментарый выдалены",
+    "An error occurred while trying to delete the comment" : "Падчас спробы выдалення каментарыя ўзнікла памылка",
+    "An error occurred while trying to create the comment" : "Падчас спробы стварэння каментарыя ўзнікла памылка"
+},
+"nplurals=4; plural=(n%10==1 && n%100!=11 ? 0 : n%10>=2 && n%10<=4 && (n%100<12 || n%100>14) ? 1 : n%10==0 || (n%10>=5 && n%10<=9) || (n%100>=11 && n%100<=14)? 2 : 3);");

apps/comments/l10n/be.json

@@ -0,0 +1,34 @@
+{ "translations": {
+    "Comments" : "Каментарыі",
+    "You commented" : "Вы пракаментавалі",
+    "{author} commented" : "{author} пракаментаваў(-ла)",
+    "You commented on %1$s" : "Вы пракаментавалі %1$s",
+    "You commented on {file}" : "Вы пракаментавалі {file}",
+    "%1$s commented on %2$s" : "%1$s пракаментаваў(-ла) %2$s",
+    "{author} commented on {file}" : "{author} пракаментаваў(-ла) {file}",
+    "<strong>Comments</strong> for files" : "<strong>Каментарыі</strong> да файлаў",
+    "Files" : "Файлы",
+    "You were mentioned on \"{file}\", in a comment by an account that has since been deleted" : "Вас згадалі ў каментарыі да \"{file}\" з уліковага запісу, які пазней быў выдалены.",
+    "{user} mentioned you in a comment on \"{file}\"" : "{user} згадаў(-ла) вас у каментарыі да \"{file}\"",
+    "Files app plugin to add comments to files" : "Убудова праграмы Файлы для дадавання каментарыяў да файлаў",
+    "Edit comment" : "Рэдагаваць каментарый",
+    "Delete comment" : "Выдаліць каментарый",
+    "Cancel edit" : "Скасаваць рэдагаванне",
+    "New comment" : "Новы каментарый",
+    "Write a comment …" : "Напішыце каментарый …",
+    "Post comment" : "Апублікаваць каментарый",
+    "@ for mentions, : for emoji, / for smart picker" : "@ - згадкі, : - эмодзі, / - разумны выбар",
+    "Could not reload comments" : "Не ўдалося перазагрузіць каментарыі",
+    "Failed to mark comments as read" : "Не атрымалася пазначыць каментарыі як прачытаныя",
+    "Unable to load the comments list" : "Не ўдалося загрузіць спіс каментарыяў",
+    "No comments yet, start the conversation!" : "Пакуль няма каментарыяў, пачніце размову!",
+    "No more messages" : "Больш паведамленняў няма",
+    "Retry" : "Паўтарыць спробу",
+    "_1 new comment_::_{unread} new comments_" : ["1 новы каментарый","{unread} новыя каментарыі","{unread} новых каментарыяў","{unread} новых каментарыяў"],
+    "Comment" : "Каментарый",
+    "An error occurred while trying to edit the comment" : "Падчас спробы рэдагавання каментарыя ўзнікла памылка",
+    "Comment deleted" : "Каментарый выдалены",
+    "An error occurred while trying to delete the comment" : "Падчас спробы выдалення каментарыя ўзнікла памылка",
+    "An error occurred while trying to create the comment" : "Падчас спробы стварэння каментарыя ўзнікла памылка"
+},"pluralForm" :"nplurals=4; plural=(n%10==1 && n%100!=11 ? 0 : n%10>=2 && n%10<=4 && (n%100<12 || n%100>14) ? 1 : n%10==0 || (n%10>=5 && n%10<=9) || (n%100>=11 && n%100<=14)? 2 : 3);"
+}

apps/contactsinteraction/composer/composer/autoload_classmap.php

@@ -16,5 +16,6 @@ return array(
     'OCA\\ContactsInteraction\\Db\\RecentContact' => $baseDir . '/../lib/Db/RecentContact.php',
     'OCA\\ContactsInteraction\\Db\\RecentContactMapper' => $baseDir . '/../lib/Db/RecentContactMapper.php',
     'OCA\\ContactsInteraction\\Listeners\\ContactInteractionListener' => $baseDir . '/../lib/Listeners/ContactInteractionListener.php',
+    'OCA\\ContactsInteraction\\Listeners\\UserDeletedListener' => $baseDir . '/../lib/Listeners/UserDeletedListener.php',
     'OCA\\ContactsInteraction\\Migration\\Version010000Date20200304152605' => $baseDir . '/../lib/Migration/Version010000Date20200304152605.php',
 );

apps/contactsinteraction/composer/composer/autoload_static.php

@@ -31,6 +31,7 @@ class ComposerStaticInitContactsInteraction
         'OCA\\ContactsInteraction\\Db\\RecentContact' => __DIR__ . '/..' . '/../lib/Db/RecentContact.php',
         'OCA\\ContactsInteraction\\Db\\RecentContactMapper' => __DIR__ . '/..' . '/../lib/Db/RecentContactMapper.php',
         'OCA\\ContactsInteraction\\Listeners\\ContactInteractionListener' => __DIR__ . '/..' . '/../lib/Listeners/ContactInteractionListener.php',
+        'OCA\\ContactsInteraction\\Listeners\\UserDeletedListener' => __DIR__ . '/..' . '/../lib/Listeners/UserDeletedListener.php',
         'OCA\\ContactsInteraction\\Migration\\Version010000Date20200304152605' => __DIR__ . '/..' . '/../lib/Migration/Version010000Date20200304152605.php',
     );
 

apps/contactsinteraction/lib/AppInfo/Application.php

@@ -9,11 +9,13 @@ declare(strict_types=1);
 namespace OCA\ContactsInteraction\AppInfo;
 
 use OCA\ContactsInteraction\Listeners\ContactInteractionListener;
+use OCA\ContactsInteraction\Listeners\UserDeletedListener;
 use OCP\AppFramework\App;
 use OCP\AppFramework\Bootstrap\IBootContext;
 use OCP\AppFramework\Bootstrap\IBootstrap;
 use OCP\AppFramework\Bootstrap\IRegistrationContext;
 use OCP\Contacts\Events\ContactInteractedWithEvent;
+use OCP\User\Events\UserDeletedEvent;
 
 class Application extends App implements IBootstrap {
 	public const APP_ID = 'contactsinteraction';
@@ -24,6 +26,7 @@ class Application extends App implements IBootstrap {
 
 	public function register(IRegistrationContext $context): void {
 		$context->registerEventListener(ContactInteractedWithEvent::class, ContactInteractionListener::class);
+		$context->registerEventListener(UserDeletedEvent::class, UserDeletedListener::class);
 	}
 
 	public function boot(IBootContext $context): void {

apps/contactsinteraction/lib/Db/RecentContactMapper.php

@@ -112,4 +112,14 @@ class RecentContactMapper extends QBMapper {
 
 		$delete->executeStatement();
 	}
+
+	public function deleteByUserId(string $uid): void {
+		$qb = $this->db->getQueryBuilder();
+
+		$delete = $qb
+			->delete($this->getTableName())
+			->where($qb->expr()->eq('actor_uid', $qb->createNamedParameter($uid)));
+
+		$delete->executeStatement();
+	}
 }

apps/contactsinteraction/lib/Listeners/UserDeletedListener.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\ContactsInteraction\Listeners;
+
+use OCA\ContactsInteraction\Db\RecentContactMapper;
+use OCP\EventDispatcher\Event;
+use OCP\EventDispatcher\IEventListener;
+use OCP\User\Events\UserDeletedEvent;
+
+/**
+ * @template-implements IEventListener<Event|UserDeletedEvent>
+ */
+class UserDeletedListener implements IEventListener {
+
+	public function __construct(
+		private readonly RecentContactMapper $recentContactMapper,
+	) {
+	}
+
+	#[\Override]
+	public function handle(Event $event): void {
+		if (!($event instanceof UserDeletedEvent)) {
+			return;
+		}
+
+		$this->recentContactMapper->deleteByUserId($event->getUser()->getUID());
+	}
+}

apps/dashboard/openapi.json

@@ -267,6 +267,34 @@
                                 }
                             }
                         }
+                    },
+                    "401": {
+                        "description": "Current user is not logged in",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object",
+                                    "required": [
+                                        "ocs"
+                                    ],
+                                    "properties": {
+                                        "ocs": {
+                                            "type": "object",
+                                            "required": [
+                                                "meta",
+                                                "data"
+                                            ],
+                                            "properties": {
+                                                "meta": {
+                                                    "$ref": "#/components/schemas/OCSMeta"
+                                                },
+                                                "data": {}
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
                     }
                 }
             }
@@ -363,6 +391,34 @@
                                 }
                             }
                         }
+                    },
+                    "401": {
+                        "description": "Current user is not logged in",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object",
+                                    "required": [
+                                        "ocs"
+                                    ],
+                                    "properties": {
+                                        "ocs": {
+                                            "type": "object",
+                                            "required": [
+                                                "meta",
+                                                "data"
+                                            ],
+                                            "properties": {
+                                                "meta": {
+                                                    "$ref": "#/components/schemas/OCSMeta"
+                                                },
+                                                "data": {}
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
                     }
                 }
             }
@@ -427,6 +483,34 @@
                                 }
                             }
                         }
+                    },
+                    "401": {
+                        "description": "Current user is not logged in",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object",
+                                    "required": [
+                                        "ocs"
+                                    ],
+                                    "properties": {
+                                        "ocs": {
+                                            "type": "object",
+                                            "required": [
+                                                "meta",
+                                                "data"
+                                            ],
+                                            "properties": {
+                                                "meta": {
+                                                    "$ref": "#/components/schemas/OCSMeta"
+                                                },
+                                                "data": {}
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
                     }
                 }
             }
@@ -499,6 +583,34 @@
                                 }
                             }
                         }
+                    },
+                    "401": {
+                        "description": "Current user is not logged in",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object",
+                                    "required": [
+                                        "ocs"
+                                    ],
+                                    "properties": {
+                                        "ocs": {
+                                            "type": "object",
+                                            "required": [
+                                                "meta",
+                                                "data"
+                                            ],
+                                            "properties": {
+                                                "meta": {
+                                                    "$ref": "#/components/schemas/OCSMeta"
+                                                },
+                                                "data": {}
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
                     }
                 }
             },
@@ -591,6 +703,34 @@
                                 }
                             }
                         }
+                    },
+                    "401": {
+                        "description": "Current user is not logged in",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object",
+                                    "required": [
+                                        "ocs"
+                                    ],
+                                    "properties": {
+                                        "ocs": {
+                                            "type": "object",
+                                            "required": [
+                                                "meta",
+                                                "data"
+                                            ],
+                                            "properties": {
+                                                "meta": {
+                                                    "$ref": "#/components/schemas/OCSMeta"
+                                                },
+                                                "data": {}
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
                     }
                 }
             }
@@ -663,6 +803,34 @@
                                 }
                             }
                         }
+                    },
+                    "401": {
+                        "description": "Current user is not logged in",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object",
+                                    "required": [
+                                        "ocs"
+                                    ],
+                                    "properties": {
+                                        "ocs": {
+                                            "type": "object",
+                                            "required": [
+                                                "meta",
+                                                "data"
+                                            ],
+                                            "properties": {
+                                                "meta": {
+                                                    "$ref": "#/components/schemas/OCSMeta"
+                                                },
+                                                "data": {}
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
                     }
                 }
             },
@@ -755,6 +923,34 @@
                                 }
                             }
                         }
+                    },
+                    "401": {
+                        "description": "Current user is not logged in",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object",
+                                    "required": [
+                                        "ocs"
+                                    ],
+                                    "properties": {
+                                        "ocs": {
+                                            "type": "object",
+                                            "required": [
+                                                "meta",
+                                                "data"
+                                            ],
+                                            "properties": {
+                                                "meta": {
+                                                    "$ref": "#/components/schemas/OCSMeta"
+                                                },
+                                                "data": {}
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
                     }
                 }
             }

apps/dav/appinfo/info.xml

@@ -10,7 +10,7 @@
 	<name>WebDAV</name>
 	<summary>WebDAV endpoint</summary>
 	<description>WebDAV endpoint</description>
-	<version>1.34.1</version>
+	<version>1.34.2</version>
 	<licence>agpl</licence>
 	<author>owncloud.org</author>
 	<namespace>DAV</namespace>
@@ -30,6 +30,7 @@
 		<job>OCA\DAV\BackgroundJob\EventReminderJob</job>
 		<job>OCA\DAV\BackgroundJob\CalendarRetentionJob</job>
 		<job>OCA\DAV\BackgroundJob\PruneOutdatedSyncTokensJob</job>
+		<job>OCA\DAV\BackgroundJob\FederatedCalendarPeriodicSyncJob</job>
 	</background-jobs>
 
 	<repair-steps>
@@ -66,6 +67,7 @@
 		<command>OCA\DAV\Command\ExportCalendar</command>
 		<command>OCA\DAV\Command\FixCalendarSyncCommand</command>
 		<command>OCA\DAV\Command\GetAbsenceCommand</command>
+		<command>OCA\DAV\Command\ImportCalendar</command>
 		<command>OCA\DAV\Command\ListAddressbooks</command>
 		<command>OCA\DAV\Command\ListCalendarShares</command>
 		<command>OCA\DAV\Command\ListCalendars</command>

apps/dav/appinfo/v1/caldav.php

@@ -10,6 +10,8 @@ use OC\KnownUser\KnownUserService;
 use OCA\DAV\CalDAV\CalDavBackend;
 use OCA\DAV\CalDAV\CalendarRoot;
 use OCA\DAV\CalDAV\DefaultCalendarValidator;
+use OCA\DAV\CalDAV\Federation\FederatedCalendarFactory;
+use OCA\DAV\CalDAV\Federation\FederatedCalendarMapper;
 use OCA\DAV\CalDAV\Proxy\ProxyMapper;
 use OCA\DAV\CalDAV\Schedule\IMipPlugin;
 use OCA\DAV\CalDAV\Security\RateLimitingPlugin;
@@ -29,6 +31,7 @@ use OCP\IRequest;
 use OCP\ISession;
 use OCP\IUserManager;
 use OCP\IUserSession;
+use OCP\L10N\IFactory as IL10NFactory;
 use OCP\Security\Bruteforce\IThrottler;
 use OCP\Security\ISecureRandom;
 use OCP\Server;
@@ -61,6 +64,9 @@ $random = Server::get(ISecureRandom::class);
 $logger = Server::get(LoggerInterface::class);
 $dispatcher = Server::get(IEventDispatcher::class);
 $config = Server::get(IConfig::class);
+$l10nFactory = Server::get(IL10NFactory::class);
+$davL10n = $l10nFactory->get('dav');
+$federatedCalendarFactory = Server::get(FederatedCalendarFactory::class);
 
 $calDavBackend = new CalDavBackend(
 	$db,
@@ -71,6 +77,8 @@ $calDavBackend = new CalDavBackend(
 	$dispatcher,
 	$config,
 	Server::get(\OCA\DAV\CalDAV\Sharing\Backend::class),
+	Server::get(FederatedCalendarMapper::class),
+	Server::get(\OCP\ICacheFactory::class),
 	true
 );
 
@@ -81,7 +89,7 @@ $sendInvitations = Server::get(IConfig::class)->getAppValue('dav', 'sendInvitati
 $principalCollection = new \Sabre\CalDAV\Principal\Collection($principalBackend);
 $principalCollection->disableListing = !$debugging; // Disable listing
 
-$addressBookRoot = new CalendarRoot($principalBackend, $calDavBackend, 'principals', $logger);
+$addressBookRoot = new CalendarRoot($principalBackend, $calDavBackend, 'principals', $logger, $davL10n, $config, $federatedCalendarFactory);
 $addressBookRoot->disableListing = !$debugging; // Disable listing
 
 $nodes = [
@@ -96,7 +104,7 @@ $server->httpRequest->setUrl(Server::get(IRequest::class)->getRequestUri());
 $server->setBaseUri($baseuri);
 
 // Add plugins
-$server->addPlugin(new MaintenancePlugin(Server::get(IConfig::class), \OC::$server->getL10N('dav')));
+$server->addPlugin(new MaintenancePlugin(Server::get(IConfig::class), $davL10n));
 $server->addPlugin(new \Sabre\DAV\Auth\Plugin($authBackend));
 $server->addPlugin(new \Sabre\CalDAV\Plugin());
 

apps/dav/composer/composer/autoload_classmap.php

@@ -19,6 +19,8 @@ return array(
     'OCA\\DAV\\BackgroundJob\\CleanupOrphanedChildrenJob' => $baseDir . '/../lib/BackgroundJob/CleanupOrphanedChildrenJob.php',
     'OCA\\DAV\\BackgroundJob\\DeleteOutdatedSchedulingObjects' => $baseDir . '/../lib/BackgroundJob/DeleteOutdatedSchedulingObjects.php',
     'OCA\\DAV\\BackgroundJob\\EventReminderJob' => $baseDir . '/../lib/BackgroundJob/EventReminderJob.php',
+    'OCA\\DAV\\BackgroundJob\\FederatedCalendarPeriodicSyncJob' => $baseDir . '/../lib/BackgroundJob/FederatedCalendarPeriodicSyncJob.php',
+    'OCA\\DAV\\BackgroundJob\\FederatedCalendarSyncJob' => $baseDir . '/../lib/BackgroundJob/FederatedCalendarSyncJob.php',
     'OCA\\DAV\\BackgroundJob\\GenerateBirthdayCalendarBackgroundJob' => $baseDir . '/../lib/BackgroundJob/GenerateBirthdayCalendarBackgroundJob.php',
     'OCA\\DAV\\BackgroundJob\\OutOfOfficeEventDispatcherJob' => $baseDir . '/../lib/BackgroundJob/OutOfOfficeEventDispatcherJob.php',
     'OCA\\DAV\\BackgroundJob\\PruneOutdatedSyncTokensJob' => $baseDir . '/../lib/BackgroundJob/PruneOutdatedSyncTokensJob.php',
@@ -66,9 +68,27 @@ return array(
     'OCA\\DAV\\CalDAV\\EventReaderRDate' => $baseDir . '/../lib/CalDAV/EventReaderRDate.php',
     'OCA\\DAV\\CalDAV\\EventReaderRRule' => $baseDir . '/../lib/CalDAV/EventReaderRRule.php',
     'OCA\\DAV\\CalDAV\\Export\\ExportService' => $baseDir . '/../lib/CalDAV/Export/ExportService.php',
+    'OCA\\DAV\\CalDAV\\Federation\\CalendarFederationConfig' => $baseDir . '/../lib/CalDAV/Federation/CalendarFederationConfig.php',
+    'OCA\\DAV\\CalDAV\\Federation\\CalendarFederationNotifier' => $baseDir . '/../lib/CalDAV/Federation/CalendarFederationNotifier.php',
+    'OCA\\DAV\\CalDAV\\Federation\\CalendarFederationProvider' => $baseDir . '/../lib/CalDAV/Federation/CalendarFederationProvider.php',
+    'OCA\\DAV\\CalDAV\\Federation\\FederatedCalendar' => $baseDir . '/../lib/CalDAV/Federation/FederatedCalendar.php',
+    'OCA\\DAV\\CalDAV\\Federation\\FederatedCalendarAuth' => $baseDir . '/../lib/CalDAV/Federation/FederatedCalendarAuth.php',
+    'OCA\\DAV\\CalDAV\\Federation\\FederatedCalendarEntity' => $baseDir . '/../lib/CalDAV/Federation/FederatedCalendarEntity.php',
+    'OCA\\DAV\\CalDAV\\Federation\\FederatedCalendarFactory' => $baseDir . '/../lib/CalDAV/Federation/FederatedCalendarFactory.php',
+    'OCA\\DAV\\CalDAV\\Federation\\FederatedCalendarImpl' => $baseDir . '/../lib/CalDAV/Federation/FederatedCalendarImpl.php',
+    'OCA\\DAV\\CalDAV\\Federation\\FederatedCalendarMapper' => $baseDir . '/../lib/CalDAV/Federation/FederatedCalendarMapper.php',
+    'OCA\\DAV\\CalDAV\\Federation\\FederatedCalendarSyncService' => $baseDir . '/../lib/CalDAV/Federation/FederatedCalendarSyncService.php',
+    'OCA\\DAV\\CalDAV\\Federation\\FederationSharingService' => $baseDir . '/../lib/CalDAV/Federation/FederationSharingService.php',
+    'OCA\\DAV\\CalDAV\\Federation\\Protocol\\CalendarFederationProtocolV1' => $baseDir . '/../lib/CalDAV/Federation/Protocol/CalendarFederationProtocolV1.php',
+    'OCA\\DAV\\CalDAV\\Federation\\Protocol\\CalendarProtocolParseException' => $baseDir . '/../lib/CalDAV/Federation/Protocol/CalendarProtocolParseException.php',
+    'OCA\\DAV\\CalDAV\\Federation\\Protocol\\ICalendarFederationProtocol' => $baseDir . '/../lib/CalDAV/Federation/Protocol/ICalendarFederationProtocol.php',
+    'OCA\\DAV\\CalDAV\\Federation\\RemoteUserCalendarHome' => $baseDir . '/../lib/CalDAV/Federation/RemoteUserCalendarHome.php',
     'OCA\\DAV\\CalDAV\\FreeBusy\\FreeBusyGenerator' => $baseDir . '/../lib/CalDAV/FreeBusy/FreeBusyGenerator.php',
     'OCA\\DAV\\CalDAV\\ICSExportPlugin\\ICSExportPlugin' => $baseDir . '/../lib/CalDAV/ICSExportPlugin/ICSExportPlugin.php',
     'OCA\\DAV\\CalDAV\\IRestorable' => $baseDir . '/../lib/CalDAV/IRestorable.php',
+    'OCA\\DAV\\CalDAV\\Import\\ImportService' => $baseDir . '/../lib/CalDAV/Import/ImportService.php',
+    'OCA\\DAV\\CalDAV\\Import\\TextImporter' => $baseDir . '/../lib/CalDAV/Import/TextImporter.php',
+    'OCA\\DAV\\CalDAV\\Import\\XmlImporter' => $baseDir . '/../lib/CalDAV/Import/XmlImporter.php',
     'OCA\\DAV\\CalDAV\\Integration\\ExternalCalendar' => $baseDir . '/../lib/CalDAV/Integration/ExternalCalendar.php',
     'OCA\\DAV\\CalDAV\\Integration\\ICalendarProvider' => $baseDir . '/../lib/CalDAV/Integration/ICalendarProvider.php',
     'OCA\\DAV\\CalDAV\\InvitationResponse\\InvitationResponseServer' => $baseDir . '/../lib/CalDAV/InvitationResponse/InvitationResponseServer.php',
@@ -113,6 +133,8 @@ return array(
     'OCA\\DAV\\CalDAV\\Sharing\\Backend' => $baseDir . '/../lib/CalDAV/Sharing/Backend.php',
     'OCA\\DAV\\CalDAV\\Sharing\\Service' => $baseDir . '/../lib/CalDAV/Sharing/Service.php',
     'OCA\\DAV\\CalDAV\\Status\\StatusService' => $baseDir . '/../lib/CalDAV/Status/StatusService.php',
+    'OCA\\DAV\\CalDAV\\SyncService' => $baseDir . '/../lib/CalDAV/SyncService.php',
+    'OCA\\DAV\\CalDAV\\SyncServiceResult' => $baseDir . '/../lib/CalDAV/SyncServiceResult.php',
     'OCA\\DAV\\CalDAV\\TimeZoneFactory' => $baseDir . '/../lib/CalDAV/TimeZoneFactory.php',
     'OCA\\DAV\\CalDAV\\TimezoneService' => $baseDir . '/../lib/CalDAV/TimezoneService.php',
     'OCA\\DAV\\CalDAV\\TipBroker' => $baseDir . '/../lib/CalDAV/TipBroker.php',
@@ -166,6 +188,7 @@ return array(
     'OCA\\DAV\\Command\\ExportCalendar' => $baseDir . '/../lib/Command/ExportCalendar.php',
     'OCA\\DAV\\Command\\FixCalendarSyncCommand' => $baseDir . '/../lib/Command/FixCalendarSyncCommand.php',
     'OCA\\DAV\\Command\\GetAbsenceCommand' => $baseDir . '/../lib/Command/GetAbsenceCommand.php',
+    'OCA\\DAV\\Command\\ImportCalendar' => $baseDir . '/../lib/Command/ImportCalendar.php',
     'OCA\\DAV\\Command\\ListAddressbooks' => $baseDir . '/../lib/Command/ListAddressbooks.php',
     'OCA\\DAV\\Command\\ListCalendarShares' => $baseDir . '/../lib/Command/ListCalendarShares.php',
     'OCA\\DAV\\Command\\ListCalendars' => $baseDir . '/../lib/Command/ListCalendars.php',
@@ -239,6 +262,7 @@ return array(
     'OCA\\DAV\\DAV\\CustomPropertiesBackend' => $baseDir . '/../lib/DAV/CustomPropertiesBackend.php',
     'OCA\\DAV\\DAV\\GroupPrincipalBackend' => $baseDir . '/../lib/DAV/GroupPrincipalBackend.php',
     'OCA\\DAV\\DAV\\PublicAuth' => $baseDir . '/../lib/DAV/PublicAuth.php',
+    'OCA\\DAV\\DAV\\RemoteUserPrincipalBackend' => $baseDir . '/../lib/DAV/RemoteUserPrincipalBackend.php',
     'OCA\\DAV\\DAV\\Sharing\\Backend' => $baseDir . '/../lib/DAV/Sharing/Backend.php',
     'OCA\\DAV\\DAV\\Sharing\\IShareable' => $baseDir . '/../lib/DAV/Sharing/IShareable.php',
     'OCA\\DAV\\DAV\\Sharing\\Plugin' => $baseDir . '/../lib/DAV/Sharing/Plugin.php',
@@ -300,6 +324,7 @@ return array(
     'OCA\\DAV\\Listener\\BirthdayListener' => $baseDir . '/../lib/Listener/BirthdayListener.php',
     'OCA\\DAV\\Listener\\CalendarContactInteractionListener' => $baseDir . '/../lib/Listener/CalendarContactInteractionListener.php',
     'OCA\\DAV\\Listener\\CalendarDeletionDefaultUpdaterListener' => $baseDir . '/../lib/Listener/CalendarDeletionDefaultUpdaterListener.php',
+    'OCA\\DAV\\Listener\\CalendarFederationNotificationListener' => $baseDir . '/../lib/Listener/CalendarFederationNotificationListener.php',
     'OCA\\DAV\\Listener\\CalendarObjectReminderUpdaterListener' => $baseDir . '/../lib/Listener/CalendarObjectReminderUpdaterListener.php',
     'OCA\\DAV\\Listener\\CalendarPublicationListener' => $baseDir . '/../lib/Listener/CalendarPublicationListener.php',
     'OCA\\DAV\\Listener\\CalendarShareUpdateListener' => $baseDir . '/../lib/Listener/CalendarShareUpdateListener.php',
@@ -307,6 +332,7 @@ return array(
     'OCA\\DAV\\Listener\\ClearPhotoCacheListener' => $baseDir . '/../lib/Listener/ClearPhotoCacheListener.php',
     'OCA\\DAV\\Listener\\DavAdminSettingsListener' => $baseDir . '/../lib/Listener/DavAdminSettingsListener.php',
     'OCA\\DAV\\Listener\\OutOfOfficeListener' => $baseDir . '/../lib/Listener/OutOfOfficeListener.php',
+    'OCA\\DAV\\Listener\\SabrePluginAuthInitListener' => $baseDir . '/../lib/Listener/SabrePluginAuthInitListener.php',
     'OCA\\DAV\\Listener\\SubscriptionListener' => $baseDir . '/../lib/Listener/SubscriptionListener.php',
     'OCA\\DAV\\Listener\\TrustedServerRemovedListener' => $baseDir . '/../lib/Listener/TrustedServerRemovedListener.php',
     'OCA\\DAV\\Listener\\UserEventsListener' => $baseDir . '/../lib/Listener/UserEventsListener.php',
@@ -355,6 +381,7 @@ return array(
     'OCA\\DAV\\Migration\\Version1029Date20231004091403' => $baseDir . '/../lib/Migration/Version1029Date20231004091403.php',
     'OCA\\DAV\\Migration\\Version1030Date20240205103243' => $baseDir . '/../lib/Migration/Version1030Date20240205103243.php',
     'OCA\\DAV\\Migration\\Version1031Date20240610134258' => $baseDir . '/../lib/Migration/Version1031Date20240610134258.php',
+    'OCA\\DAV\\Migration\\Version1034Date20250605132605' => $baseDir . '/../lib/Migration/Version1034Date20250605132605.php',
     'OCA\\DAV\\Migration\\Version1034Date20250813093701' => $baseDir . '/../lib/Migration/Version1034Date20250813093701.php',
     'OCA\\DAV\\Model\\ExampleEvent' => $baseDir . '/../lib/Model/ExampleEvent.php',
     'OCA\\DAV\\Paginate\\LimitedCopyIterator' => $baseDir . '/../lib/Paginate/LimitedCopyIterator.php',
@@ -371,6 +398,7 @@ return array(
     'OCA\\DAV\\Search\\TasksSearchProvider' => $baseDir . '/../lib/Search/TasksSearchProvider.php',
     'OCA\\DAV\\Server' => $baseDir . '/../lib/Server.php',
     'OCA\\DAV\\ServerFactory' => $baseDir . '/../lib/ServerFactory.php',
+    'OCA\\DAV\\Service\\ASyncService' => $baseDir . '/../lib/Service/ASyncService.php',
     'OCA\\DAV\\Service\\AbsenceService' => $baseDir . '/../lib/Service/AbsenceService.php',
     'OCA\\DAV\\Service\\ExampleContactService' => $baseDir . '/../lib/Service/ExampleContactService.php',
     'OCA\\DAV\\Service\\ExampleEventService' => $baseDir . '/../lib/Service/ExampleEventService.php',

apps/dav/composer/composer/autoload_static.php

@@ -34,6 +34,8 @@ class ComposerStaticInitDAV
         'OCA\\DAV\\BackgroundJob\\CleanupOrphanedChildrenJob' => __DIR__ . '/..' . '/../lib/BackgroundJob/CleanupOrphanedChildrenJob.php',
         'OCA\\DAV\\BackgroundJob\\DeleteOutdatedSchedulingObjects' => __DIR__ . '/..' . '/../lib/BackgroundJob/DeleteOutdatedSchedulingObjects.php',
         'OCA\\DAV\\BackgroundJob\\EventReminderJob' => __DIR__ . '/..' . '/../lib/BackgroundJob/EventReminderJob.php',
+        'OCA\\DAV\\BackgroundJob\\FederatedCalendarPeriodicSyncJob' => __DIR__ . '/..' . '/../lib/BackgroundJob/FederatedCalendarPeriodicSyncJob.php',
+        'OCA\\DAV\\BackgroundJob\\FederatedCalendarSyncJob' => __DIR__ . '/..' . '/../lib/BackgroundJob/FederatedCalendarSyncJob.php',
         'OCA\\DAV\\BackgroundJob\\GenerateBirthdayCalendarBackgroundJob' => __DIR__ . '/..' . '/../lib/BackgroundJob/GenerateBirthdayCalendarBackgroundJob.php',
         'OCA\\DAV\\BackgroundJob\\OutOfOfficeEventDispatcherJob' => __DIR__ . '/..' . '/../lib/BackgroundJob/OutOfOfficeEventDispatcherJob.php',
         'OCA\\DAV\\BackgroundJob\\PruneOutdatedSyncTokensJob' => __DIR__ . '/..' . '/../lib/BackgroundJob/PruneOutdatedSyncTokensJob.php',
@@ -81,9 +83,27 @@ class ComposerStaticInitDAV
         'OCA\\DAV\\CalDAV\\EventReaderRDate' => __DIR__ . '/..' . '/../lib/CalDAV/EventReaderRDate.php',
         'OCA\\DAV\\CalDAV\\EventReaderRRule' => __DIR__ . '/..' . '/../lib/CalDAV/EventReaderRRule.php',
         'OCA\\DAV\\CalDAV\\Export\\ExportService' => __DIR__ . '/..' . '/../lib/CalDAV/Export/ExportService.php',
+        'OCA\\DAV\\CalDAV\\Federation\\CalendarFederationConfig' => __DIR__ . '/..' . '/../lib/CalDAV/Federation/CalendarFederationConfig.php',
+        'OCA\\DAV\\CalDAV\\Federation\\CalendarFederationNotifier' => __DIR__ . '/..' . '/../lib/CalDAV/Federation/CalendarFederationNotifier.php',
+        'OCA\\DAV\\CalDAV\\Federation\\CalendarFederationProvider' => __DIR__ . '/..' . '/../lib/CalDAV/Federation/CalendarFederationProvider.php',
+        'OCA\\DAV\\CalDAV\\Federation\\FederatedCalendar' => __DIR__ . '/..' . '/../lib/CalDAV/Federation/FederatedCalendar.php',
+        'OCA\\DAV\\CalDAV\\Federation\\FederatedCalendarAuth' => __DIR__ . '/..' . '/../lib/CalDAV/Federation/FederatedCalendarAuth.php',
+        'OCA\\DAV\\CalDAV\\Federation\\FederatedCalendarEntity' => __DIR__ . '/..' . '/../lib/CalDAV/Federation/FederatedCalendarEntity.php',
+        'OCA\\DAV\\CalDAV\\Federation\\FederatedCalendarFactory' => __DIR__ . '/..' . '/../lib/CalDAV/Federation/FederatedCalendarFactory.php',
+        'OCA\\DAV\\CalDAV\\Federation\\FederatedCalendarImpl' => __DIR__ . '/..' . '/../lib/CalDAV/Federation/FederatedCalendarImpl.php',
+        'OCA\\DAV\\CalDAV\\Federation\\FederatedCalendarMapper' => __DIR__ . '/..' . '/../lib/CalDAV/Federation/FederatedCalendarMapper.php',
+        'OCA\\DAV\\CalDAV\\Federation\\FederatedCalendarSyncService' => __DIR__ . '/..' . '/../lib/CalDAV/Federation/FederatedCalendarSyncService.php',
+        'OCA\\DAV\\CalDAV\\Federation\\FederationSharingService' => __DIR__ . '/..' . '/../lib/CalDAV/Federation/FederationSharingService.php',
+        'OCA\\DAV\\CalDAV\\Federation\\Protocol\\CalendarFederationProtocolV1' => __DIR__ . '/..' . '/../lib/CalDAV/Federation/Protocol/CalendarFederationProtocolV1.php',
+        'OCA\\DAV\\CalDAV\\Federation\\Protocol\\CalendarProtocolParseException' => __DIR__ . '/..' . '/../lib/CalDAV/Federation/Protocol/CalendarProtocolParseException.php',
+        'OCA\\DAV\\CalDAV\\Federation\\Protocol\\ICalendarFederationProtocol' => __DIR__ . '/..' . '/../lib/CalDAV/Federation/Protocol/ICalendarFederationProtocol.php',
+        'OCA\\DAV\\CalDAV\\Federation\\RemoteUserCalendarHome' => __DIR__ . '/..' . '/../lib/CalDAV/Federation/RemoteUserCalendarHome.php',
         'OCA\\DAV\\CalDAV\\FreeBusy\\FreeBusyGenerator' => __DIR__ . '/..' . '/../lib/CalDAV/FreeBusy/FreeBusyGenerator.php',
         'OCA\\DAV\\CalDAV\\ICSExportPlugin\\ICSExportPlugin' => __DIR__ . '/..' . '/../lib/CalDAV/ICSExportPlugin/ICSExportPlugin.php',
         'OCA\\DAV\\CalDAV\\IRestorable' => __DIR__ . '/..' . '/../lib/CalDAV/IRestorable.php',
+        'OCA\\DAV\\CalDAV\\Import\\ImportService' => __DIR__ . '/..' . '/../lib/CalDAV/Import/ImportService.php',
+        'OCA\\DAV\\CalDAV\\Import\\TextImporter' => __DIR__ . '/..' . '/../lib/CalDAV/Import/TextImporter.php',
+        'OCA\\DAV\\CalDAV\\Import\\XmlImporter' => __DIR__ . '/..' . '/../lib/CalDAV/Import/XmlImporter.php',
         'OCA\\DAV\\CalDAV\\Integration\\ExternalCalendar' => __DIR__ . '/..' . '/../lib/CalDAV/Integration/ExternalCalendar.php',
         'OCA\\DAV\\CalDAV\\Integration\\ICalendarProvider' => __DIR__ . '/..' . '/../lib/CalDAV/Integration/ICalendarProvider.php',
         'OCA\\DAV\\CalDAV\\InvitationResponse\\InvitationResponseServer' => __DIR__ . '/..' . '/../lib/CalDAV/InvitationResponse/InvitationResponseServer.php',
@@ -128,6 +148,8 @@ class ComposerStaticInitDAV
         'OCA\\DAV\\CalDAV\\Sharing\\Backend' => __DIR__ . '/..' . '/../lib/CalDAV/Sharing/Backend.php',
         'OCA\\DAV\\CalDAV\\Sharing\\Service' => __DIR__ . '/..' . '/../lib/CalDAV/Sharing/Service.php',
         'OCA\\DAV\\CalDAV\\Status\\StatusService' => __DIR__ . '/..' . '/../lib/CalDAV/Status/StatusService.php',
+        'OCA\\DAV\\CalDAV\\SyncService' => __DIR__ . '/..' . '/../lib/CalDAV/SyncService.php',
+        'OCA\\DAV\\CalDAV\\SyncServiceResult' => __DIR__ . '/..' . '/../lib/CalDAV/SyncServiceResult.php',
         'OCA\\DAV\\CalDAV\\TimeZoneFactory' => __DIR__ . '/..' . '/../lib/CalDAV/TimeZoneFactory.php',
         'OCA\\DAV\\CalDAV\\TimezoneService' => __DIR__ . '/..' . '/../lib/CalDAV/TimezoneService.php',
         'OCA\\DAV\\CalDAV\\TipBroker' => __DIR__ . '/..' . '/../lib/CalDAV/TipBroker.php',
@@ -181,6 +203,7 @@ class ComposerStaticInitDAV
         'OCA\\DAV\\Command\\ExportCalendar' => __DIR__ . '/..' . '/../lib/Command/ExportCalendar.php',
         'OCA\\DAV\\Command\\FixCalendarSyncCommand' => __DIR__ . '/..' . '/../lib/Command/FixCalendarSyncCommand.php',
         'OCA\\DAV\\Command\\GetAbsenceCommand' => __DIR__ . '/..' . '/../lib/Command/GetAbsenceCommand.php',
+        'OCA\\DAV\\Command\\ImportCalendar' => __DIR__ . '/..' . '/../lib/Command/ImportCalendar.php',
         'OCA\\DAV\\Command\\ListAddressbooks' => __DIR__ . '/..' . '/../lib/Command/ListAddressbooks.php',
         'OCA\\DAV\\Command\\ListCalendarShares' => __DIR__ . '/..' . '/../lib/Command/ListCalendarShares.php',
         'OCA\\DAV\\Command\\ListCalendars' => __DIR__ . '/..' . '/../lib/Command/ListCalendars.php',
@@ -254,6 +277,7 @@ class ComposerStaticInitDAV
         'OCA\\DAV\\DAV\\CustomPropertiesBackend' => __DIR__ . '/..' . '/../lib/DAV/CustomPropertiesBackend.php',
         'OCA\\DAV\\DAV\\GroupPrincipalBackend' => __DIR__ . '/..' . '/../lib/DAV/GroupPrincipalBackend.php',
         'OCA\\DAV\\DAV\\PublicAuth' => __DIR__ . '/..' . '/../lib/DAV/PublicAuth.php',
+        'OCA\\DAV\\DAV\\RemoteUserPrincipalBackend' => __DIR__ . '/..' . '/../lib/DAV/RemoteUserPrincipalBackend.php',
         'OCA\\DAV\\DAV\\Sharing\\Backend' => __DIR__ . '/..' . '/../lib/DAV/Sharing/Backend.php',
         'OCA\\DAV\\DAV\\Sharing\\IShareable' => __DIR__ . '/..' . '/../lib/DAV/Sharing/IShareable.php',
         'OCA\\DAV\\DAV\\Sharing\\Plugin' => __DIR__ . '/..' . '/../lib/DAV/Sharing/Plugin.php',
@@ -315,6 +339,7 @@ class ComposerStaticInitDAV
         'OCA\\DAV\\Listener\\BirthdayListener' => __DIR__ . '/..' . '/../lib/Listener/BirthdayListener.php',
         'OCA\\DAV\\Listener\\CalendarContactInteractionListener' => __DIR__ . '/..' . '/../lib/Listener/CalendarContactInteractionListener.php',
         'OCA\\DAV\\Listener\\CalendarDeletionDefaultUpdaterListener' => __DIR__ . '/..' . '/../lib/Listener/CalendarDeletionDefaultUpdaterListener.php',
+        'OCA\\DAV\\Listener\\CalendarFederationNotificationListener' => __DIR__ . '/..' . '/../lib/Listener/CalendarFederationNotificationListener.php',
         'OCA\\DAV\\Listener\\CalendarObjectReminderUpdaterListener' => __DIR__ . '/..' . '/../lib/Listener/CalendarObjectReminderUpdaterListener.php',
         'OCA\\DAV\\Listener\\CalendarPublicationListener' => __DIR__ . '/..' . '/../lib/Listener/CalendarPublicationListener.php',
         'OCA\\DAV\\Listener\\CalendarShareUpdateListener' => __DIR__ . '/..' . '/../lib/Listener/CalendarShareUpdateListener.php',
@@ -322,6 +347,7 @@ class ComposerStaticInitDAV
         'OCA\\DAV\\Listener\\ClearPhotoCacheListener' => __DIR__ . '/..' . '/../lib/Listener/ClearPhotoCacheListener.php',
         'OCA\\DAV\\Listener\\DavAdminSettingsListener' => __DIR__ . '/..' . '/../lib/Listener/DavAdminSettingsListener.php',
         'OCA\\DAV\\Listener\\OutOfOfficeListener' => __DIR__ . '/..' . '/../lib/Listener/OutOfOfficeListener.php',
+        'OCA\\DAV\\Listener\\SabrePluginAuthInitListener' => __DIR__ . '/..' . '/../lib/Listener/SabrePluginAuthInitListener.php',
         'OCA\\DAV\\Listener\\SubscriptionListener' => __DIR__ . '/..' . '/../lib/Listener/SubscriptionListener.php',
         'OCA\\DAV\\Listener\\TrustedServerRemovedListener' => __DIR__ . '/..' . '/../lib/Listener/TrustedServerRemovedListener.php',
         'OCA\\DAV\\Listener\\UserEventsListener' => __DIR__ . '/..' . '/../lib/Listener/UserEventsListener.php',
@@ -370,6 +396,7 @@ class ComposerStaticInitDAV
         'OCA\\DAV\\Migration\\Version1029Date20231004091403' => __DIR__ . '/..' . '/../lib/Migration/Version1029Date20231004091403.php',
         'OCA\\DAV\\Migration\\Version1030Date20240205103243' => __DIR__ . '/..' . '/../lib/Migration/Version1030Date20240205103243.php',
         'OCA\\DAV\\Migration\\Version1031Date20240610134258' => __DIR__ . '/..' . '/../lib/Migration/Version1031Date20240610134258.php',
+        'OCA\\DAV\\Migration\\Version1034Date20250605132605' => __DIR__ . '/..' . '/../lib/Migration/Version1034Date20250605132605.php',
         'OCA\\DAV\\Migration\\Version1034Date20250813093701' => __DIR__ . '/..' . '/../lib/Migration/Version1034Date20250813093701.php',
         'OCA\\DAV\\Model\\ExampleEvent' => __DIR__ . '/..' . '/../lib/Model/ExampleEvent.php',
         'OCA\\DAV\\Paginate\\LimitedCopyIterator' => __DIR__ . '/..' . '/../lib/Paginate/LimitedCopyIterator.php',
@@ -386,6 +413,7 @@ class ComposerStaticInitDAV
         'OCA\\DAV\\Search\\TasksSearchProvider' => __DIR__ . '/..' . '/../lib/Search/TasksSearchProvider.php',
         'OCA\\DAV\\Server' => __DIR__ . '/..' . '/../lib/Server.php',
         'OCA\\DAV\\ServerFactory' => __DIR__ . '/..' . '/../lib/ServerFactory.php',
+        'OCA\\DAV\\Service\\ASyncService' => __DIR__ . '/..' . '/../lib/Service/ASyncService.php',
         'OCA\\DAV\\Service\\AbsenceService' => __DIR__ . '/..' . '/../lib/Service/AbsenceService.php',
         'OCA\\DAV\\Service\\ExampleContactService' => __DIR__ . '/..' . '/../lib/Service/ExampleContactService.php',
         'OCA\\DAV\\Service\\ExampleEventService' => __DIR__ . '/..' . '/../lib/Service/ExampleEventService.php',

apps/dav/l10n/eu.js

@@ -194,6 +194,7 @@ OC.L10N.register(
     "Second Last" : "Azken aurrekoa",
     "Third Last" : "Hirugarren azkena",
     "Fourth Last" : "Laugarren azkena",
+    "Fifth Last" : "Bosgarren azkena",
     "Contacts" : "Kontaktuak",
     "{actor} created address book {addressbook}" : "{actor}-(e)k {addressbook} helbide-liburua sortu du ",
     "You created address book {addressbook}" : "{addressbook} helbide-liburua sortu duzu",

apps/dav/l10n/eu.json

@@ -192,6 +192,7 @@
     "Second Last" : "Azken aurrekoa",
     "Third Last" : "Hirugarren azkena",
     "Fourth Last" : "Laugarren azkena",
+    "Fifth Last" : "Bosgarren azkena",
     "Contacts" : "Kontaktuak",
     "{actor} created address book {addressbook}" : "{actor}-(e)k {addressbook} helbide-liburua sortu du ",
     "You created address book {addressbook}" : "{addressbook} helbide-liburua sortu duzu",

apps/dav/l10n/nl.js

@@ -127,6 +127,20 @@ OC.L10N.register(
     "_In a week on %1$s_::_In %n weeks on %1$s_" : ["Over een week op %1$s","Over %n weken op %1$s"],
     "_In a month on %1$s_::_In %n months on %1$s_" : ["Over een maand op %1$s","Over %n maanden op %1$s"],
     "_In a year on %1$s_::_In %n years on %1$s_" : ["Over een jaar op %1$s","Over %n jaar op %1$s"],
+    "In the past on %1$s then on %2$s" : "In het verleden op %1$s dan op %2$s",
+    "_In a minute on %1$s then on %2$s_::_In %n minutes on %1$s then on %2$s_" : ["Over een minuut op %1$s dan op %2$s","Over %n minuten op %1$s dan op %2$s"],
+    "_In a hour on %1$s then on %2$s_::_In %n hours on %1$s then on %2$s_" : ["Over een uur op %1$s dan op %2$s","Over %n uren op %1$s dan op %2$s"],
+    "_In a day on %1$s then on %2$s_::_In %n days on %1$s then on %2$s_" : ["Over een dag op %1$s dan op %2$s","Over %n dagen op %1$s dan op %2$s"],
+    "_In a week on %1$s then on %2$s_::_In %n weeks on %1$s then on %2$s_" : ["Over een week op %1$s dan op %2$s","Over %n weken op %1$s dan op %2$s"],
+    "_In a month on %1$s then on %2$s_::_In %n months on %1$s then on %2$s_" : ["Over een maand op %1$s dan op %2$s","Over %n maanden op %1$s dan op %2$s"],
+    "_In a year on %1$s then on %2$s_::_In %n years on %1$s then on %2$s_" : ["Over een jaar op %1$s dan op %2$s","Over %n jaren op %1$s dan op %2$s"],
+    "In the past on %1$s then on %2$s and %3$s" : "In het verleden op %1$s dan op %2$s en %3$s",
+    "_In a minute on %1$s then on %2$s and %3$s_::_In %n minutes on %1$s then on %2$s and %3$s_" : ["Over een minuut op %1$s dan op %2$s en %3$s","Over %n minuten op %1$s dan op %2$s en %3$s"],
+    "_In a hour on %1$s then on %2$s and %3$s_::_In %n hours on %1$s then on %2$s and %3$s_" : ["Over een uur op %1$s dan op %2$s en %3$s","Over %n uren op %1$s dan op %2$s en %3$s"],
+    "_In a day on %1$s then on %2$s and %3$s_::_In %n days on %1$s then on %2$s and %3$s_" : ["Over een dag op %1$s dan op %2$s en %3$s","Over %n dagen op %1$s dan op %2$s en %3$s"],
+    "_In a week on %1$s then on %2$s and %3$s_::_In %n weeks on %1$s then on %2$s and %3$s_" : ["Over een week op %1$s dan op %2$s en %3$s","Over %n weken op %1$s dan op %2$s en %3$s"],
+    "_In a month on %1$s then on %2$s and %3$s_::_In %n months on %1$s then on %2$s and %3$s_" : ["Over een maand op %1$s dan op %2$s en %3$s","Over %n maanden op %1$s then on %2$s and %3$s"],
+    "_In a year on %1$s then on %2$s and %3$s_::_In %n years on %1$s then on %2$s and %3$s_" : ["Over een jaar op %1$s dan op %2$s en %3$s","Over %n jaren op %1$s dan op %2$s en %3$s"],
     "Cancelled: %1$s" : "Geannuleerd: %1$s",
     "\"%1$s\" has been canceled" : "\"%1$s\" is geannuleerd",
     "Re: %1$s" : "Re: %1$s",

apps/dav/l10n/nl.json

@@ -125,6 +125,20 @@
     "_In a week on %1$s_::_In %n weeks on %1$s_" : ["Over een week op %1$s","Over %n weken op %1$s"],
     "_In a month on %1$s_::_In %n months on %1$s_" : ["Over een maand op %1$s","Over %n maanden op %1$s"],
     "_In a year on %1$s_::_In %n years on %1$s_" : ["Over een jaar op %1$s","Over %n jaar op %1$s"],
+    "In the past on %1$s then on %2$s" : "In het verleden op %1$s dan op %2$s",
+    "_In a minute on %1$s then on %2$s_::_In %n minutes on %1$s then on %2$s_" : ["Over een minuut op %1$s dan op %2$s","Over %n minuten op %1$s dan op %2$s"],
+    "_In a hour on %1$s then on %2$s_::_In %n hours on %1$s then on %2$s_" : ["Over een uur op %1$s dan op %2$s","Over %n uren op %1$s dan op %2$s"],
+    "_In a day on %1$s then on %2$s_::_In %n days on %1$s then on %2$s_" : ["Over een dag op %1$s dan op %2$s","Over %n dagen op %1$s dan op %2$s"],
+    "_In a week on %1$s then on %2$s_::_In %n weeks on %1$s then on %2$s_" : ["Over een week op %1$s dan op %2$s","Over %n weken op %1$s dan op %2$s"],
+    "_In a month on %1$s then on %2$s_::_In %n months on %1$s then on %2$s_" : ["Over een maand op %1$s dan op %2$s","Over %n maanden op %1$s dan op %2$s"],
+    "_In a year on %1$s then on %2$s_::_In %n years on %1$s then on %2$s_" : ["Over een jaar op %1$s dan op %2$s","Over %n jaren op %1$s dan op %2$s"],
+    "In the past on %1$s then on %2$s and %3$s" : "In het verleden op %1$s dan op %2$s en %3$s",
+    "_In a minute on %1$s then on %2$s and %3$s_::_In %n minutes on %1$s then on %2$s and %3$s_" : ["Over een minuut op %1$s dan op %2$s en %3$s","Over %n minuten op %1$s dan op %2$s en %3$s"],
+    "_In a hour on %1$s then on %2$s and %3$s_::_In %n hours on %1$s then on %2$s and %3$s_" : ["Over een uur op %1$s dan op %2$s en %3$s","Over %n uren op %1$s dan op %2$s en %3$s"],
+    "_In a day on %1$s then on %2$s and %3$s_::_In %n days on %1$s then on %2$s and %3$s_" : ["Over een dag op %1$s dan op %2$s en %3$s","Over %n dagen op %1$s dan op %2$s en %3$s"],
+    "_In a week on %1$s then on %2$s and %3$s_::_In %n weeks on %1$s then on %2$s and %3$s_" : ["Over een week op %1$s dan op %2$s en %3$s","Over %n weken op %1$s dan op %2$s en %3$s"],
+    "_In a month on %1$s then on %2$s and %3$s_::_In %n months on %1$s then on %2$s and %3$s_" : ["Over een maand op %1$s dan op %2$s en %3$s","Over %n maanden op %1$s then on %2$s and %3$s"],
+    "_In a year on %1$s then on %2$s and %3$s_::_In %n years on %1$s then on %2$s and %3$s_" : ["Over een jaar op %1$s dan op %2$s en %3$s","Over %n jaren op %1$s dan op %2$s en %3$s"],
     "Cancelled: %1$s" : "Geannuleerd: %1$s",
     "\"%1$s\" has been canceled" : "\"%1$s\" is geannuleerd",
     "Re: %1$s" : "Re: %1$s",

apps/dav/lib/AppInfo/Application.php

@@ -13,6 +13,7 @@ use OCA\DAV\CalDAV\AppCalendar\AppCalendarPlugin;
 use OCA\DAV\CalDAV\CachedSubscriptionProvider;
 use OCA\DAV\CalDAV\CalendarManager;
 use OCA\DAV\CalDAV\CalendarProvider;
+use OCA\DAV\CalDAV\Federation\CalendarFederationProvider;
 use OCA\DAV\CalDAV\Reminder\NotificationProvider\AudioProvider;
 use OCA\DAV\CalDAV\Reminder\NotificationProvider\EmailProvider;
 use OCA\DAV\CalDAV\Reminder\NotificationProvider\PushProvider;
@@ -36,6 +37,7 @@ use OCA\DAV\Events\CalendarUpdatedEvent;
 use OCA\DAV\Events\CardCreatedEvent;
 use OCA\DAV\Events\CardDeletedEvent;
 use OCA\DAV\Events\CardUpdatedEvent;
+use OCA\DAV\Events\SabrePluginAuthInitEvent;
 use OCA\DAV\Events\SubscriptionCreatedEvent;
 use OCA\DAV\Events\SubscriptionDeletedEvent;
 use OCA\DAV\Listener\ActivityUpdaterListener;
@@ -44,6 +46,7 @@ use OCA\DAV\Listener\AddressbookListener;
 use OCA\DAV\Listener\BirthdayListener;
 use OCA\DAV\Listener\CalendarContactInteractionListener;
 use OCA\DAV\Listener\CalendarDeletionDefaultUpdaterListener;
+use OCA\DAV\Listener\CalendarFederationNotificationListener;
 use OCA\DAV\Listener\CalendarObjectReminderUpdaterListener;
 use OCA\DAV\Listener\CalendarPublicationListener;
 use OCA\DAV\Listener\CalendarShareUpdateListener;
@@ -51,6 +54,7 @@ use OCA\DAV\Listener\CardListener;
 use OCA\DAV\Listener\ClearPhotoCacheListener;
 use OCA\DAV\Listener\DavAdminSettingsListener;
 use OCA\DAV\Listener\OutOfOfficeListener;
+use OCA\DAV\Listener\SabrePluginAuthInitListener;
 use OCA\DAV\Listener\SubscriptionListener;
 use OCA\DAV\Listener\TrustedServerRemovedListener;
 use OCA\DAV\Listener\UserEventsListener;
@@ -82,6 +86,7 @@ use OCP\Config\BeforePreferenceSetEvent;
 use OCP\Contacts\IManager as IContactsManager;
 use OCP\DB\Events\AddMissingIndicesEvent;
 use OCP\Federation\Events\TrustedServerRemovedEvent;
+use OCP\Federation\ICloudFederationProviderManager;
 use OCP\IUserSession;
 use OCP\Server;
 use OCP\Settings\Events\DeclarativeSettingsGetValueEvent;
@@ -198,6 +203,12 @@ class Application extends App implements IBootstrap {
 		$context->registerEventListener(UserChangedEvent::class, UserEventsListener::class);
 		$context->registerEventListener(UserUpdatedEvent::class, UserEventsListener::class);
 
+		$context->registerEventListener(SabrePluginAuthInitEvent::class, SabrePluginAuthInitListener::class);
+
+		$context->registerEventListener(CalendarObjectCreatedEvent::class, CalendarFederationNotificationListener::class);
+		$context->registerEventListener(CalendarObjectUpdatedEvent::class, CalendarFederationNotificationListener::class);
+		$context->registerEventListener(CalendarObjectDeletedEvent::class, CalendarFederationNotificationListener::class);
+
 		$context->registerNotifierService(Notifier::class);
 
 		$context->registerCalendarProvider(CalendarProvider::class);
@@ -213,7 +224,6 @@ class Application extends App implements IBootstrap {
 		$context->registerDeclarativeSettings(SystemAddressBookSettings::class);
 		$context->registerEventListener(DeclarativeSettingsGetValueEvent::class, DavAdminSettingsListener::class);
 		$context->registerEventListener(DeclarativeSettingsSetValueEvent::class, DavAdminSettingsListener::class);
-
 	}
 
 	public function boot(IBootContext $context): void {
@@ -223,6 +233,7 @@ class Application extends App implements IBootstrap {
 		$context->injectFn($this->registerContactsManager(...));
 		$context->injectFn($this->registerCalendarManager(...));
 		$context->injectFn($this->registerCalendarReminders(...));
+		$context->injectFn($this->registerCloudFederationProvider(...));
 	}
 
 	public function registerContactsManager(IContactsManager $cm, IAppContainer $container): void {
@@ -279,4 +290,14 @@ class Application extends App implements IBootstrap {
 			$logger->error($ex->getMessage(), ['exception' => $ex]);
 		}
 	}
+
+	public function registerCloudFederationProvider(
+		ICloudFederationProviderManager $manager,
+	): void {
+		$manager->addCloudFederationProvider(
+			CalendarFederationProvider::PROVIDER_ID,
+			'Calendar Federation',
+			static fn () => Server::get(CalendarFederationProvider::class),
+		);
+	}
 }

apps/dav/lib/BackgroundJob/FederatedCalendarPeriodicSyncJob.php

@@ -0,0 +1,62 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\BackgroundJob;
+
+use OCA\DAV\CalDAV\Federation\CalendarFederationConfig;
+use OCA\DAV\CalDAV\Federation\FederatedCalendarMapper;
+use OCA\DAV\CalDAV\Federation\FederatedCalendarSyncService;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\BackgroundJob\TimedJob;
+use Psr\Http\Client\ClientExceptionInterface;
+use Psr\Log\LoggerInterface;
+
+class FederatedCalendarPeriodicSyncJob extends TimedJob {
+	private const DOWNLOAD_LIMIT = 500;
+
+	public function __construct(
+		ITimeFactory $time,
+		private readonly FederatedCalendarSyncService $syncService,
+		private readonly FederatedCalendarMapper $federatedCalendarMapper,
+		private readonly CalendarFederationConfig $calendarFederationConfig,
+		private readonly LoggerInterface $logger,
+	) {
+		parent::__construct($time);
+
+		$this->setTimeSensitivity(self::TIME_SENSITIVE);
+		$this->setAllowParallelRuns(false);
+		$this->setInterval(3600);
+	}
+
+	protected function run($argument): void {
+		if (!$this->calendarFederationConfig->isFederationEnabled()) {
+			return;
+		}
+
+		$downloadedEvents = 0;
+		$oneHourAgo = $this->time->getTime() - 3600;
+		$calendars = $this->federatedCalendarMapper->findUnsyncedSinceBefore($oneHourAgo);
+		foreach ($calendars as $calendar) {
+			try {
+				$downloadedEvents += $this->syncService->syncOne($calendar);
+			} catch (ClientExceptionInterface $e) {
+				$name = $calendar->getUri();
+				$this->logger->error("Failed to sync federated calendar $name: " . $e->getMessage(), [
+					'exception' => $e,
+					'calendar' => $calendar->toCalendarInfo(),
+				]);
+			}
+
+			// Prevent stalling the background job queue for too long
+			if ($downloadedEvents >= self::DOWNLOAD_LIMIT) {
+				break;
+			}
+		}
+	}
+}

apps/dav/lib/BackgroundJob/FederatedCalendarSyncJob.php

@@ -0,0 +1,67 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\BackgroundJob;
+
+use OCA\DAV\CalDAV\Federation\CalendarFederationConfig;
+use OCA\DAV\CalDAV\Federation\FederatedCalendarMapper;
+use OCA\DAV\CalDAV\Federation\FederatedCalendarSyncService;
+use OCP\AppFramework\Db\DoesNotExistException;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\BackgroundJob\QueuedJob;
+use Psr\Http\Client\ClientExceptionInterface;
+use Psr\Log\LoggerInterface;
+
+class FederatedCalendarSyncJob extends QueuedJob {
+	public const ARGUMENT_ID = 'id';
+
+	public function __construct(
+		ITimeFactory $time,
+		private readonly FederatedCalendarSyncService $syncService,
+		private readonly FederatedCalendarMapper $federatedCalendarMapper,
+		private readonly CalendarFederationConfig $calendarFederationConfig,
+		private readonly LoggerInterface $logger,
+	) {
+		parent::__construct($time);
+
+		$this->setAllowParallelRuns(false);
+	}
+
+	protected function run($argument): void {
+		if (!$this->calendarFederationConfig->isFederationEnabled()) {
+			return;
+		}
+
+		$id = $argument[self::ARGUMENT_ID] ?? null;
+		if (!is_numeric($id)) {
+			return;
+		}
+
+		$id = (int)$id;
+		try {
+			$calendar = $this->federatedCalendarMapper->find($id);
+		} catch (DoesNotExistException $e) {
+			return;
+		}
+
+		try {
+			$this->syncService->syncOne($calendar);
+		} catch (ClientExceptionInterface $e) {
+			$name = $calendar->getUri();
+			$this->logger->error("Failed to sync federated calendar $name: " . $e->getMessage(), [
+				'exception' => $e,
+				'calendar' => $calendar->toCalendarInfo(),
+			]);
+
+			// Let the periodic background job pick up the calendar at a later point
+			$calendar->setLastSync(1);
+			$this->federatedCalendarMapper->update($calendar);
+		}
+	}
+}

apps/dav/lib/CalDAV/AppCalendar/AppCalendarPlugin.php

@@ -11,6 +11,7 @@ namespace OCA\DAV\CalDAV\AppCalendar;
 
 use OCA\DAV\CalDAV\CachedSubscriptionImpl;
 use OCA\DAV\CalDAV\CalendarImpl;
+use OCA\DAV\CalDAV\Federation\FederatedCalendarImpl;
 use OCA\DAV\CalDAV\Integration\ExternalCalendar;
 use OCA\DAV\CalDAV\Integration\ICalendarProvider;
 use OCP\Calendar\IManager;
@@ -51,7 +52,11 @@ class AppCalendarPlugin implements ICalendarProvider {
 		return array_values(
 			array_filter($this->manager->getCalendarsForPrincipal($principalUri, $calendarUris), function ($c) {
 				// We must not provide a wrapper for DAV calendars
-				return ! (($c instanceof CalendarImpl) || ($c instanceof CachedSubscriptionImpl));
+				return !(
+					($c instanceof CalendarImpl)
+					|| ($c instanceof CachedSubscriptionImpl)
+					|| ($c instanceof FederatedCalendarImpl)
+				);
 			})
 		);
 	}

apps/dav/lib/CalDAV/CalDavBackend.php

@@ -12,6 +12,8 @@ use DateTimeImmutable;
 use DateTimeInterface;
 use Generator;
 use OCA\DAV\AppInfo\Application;
+use OCA\DAV\CalDAV\Federation\FederatedCalendarEntity;
+use OCA\DAV\CalDAV\Federation\FederatedCalendarMapper;
 use OCA\DAV\CalDAV\Sharing\Backend;
 use OCA\DAV\Connector\Sabre\Principal;
 use OCA\DAV\DAV\Sharing\IShareable;
@@ -41,6 +43,8 @@ use OCP\Calendar\Exceptions\CalendarException;
 use OCP\DB\Exception;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\EventDispatcher\IEventDispatcher;
+use OCP\ICache;
+use OCP\ICacheFactory;
 use OCP\IConfig;
 use OCP\IDBConnection;
 use OCP\IUserManager;
@@ -110,6 +114,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 
 	public const CALENDAR_TYPE_CALENDAR = 0;
 	public const CALENDAR_TYPE_SUBSCRIPTION = 1;
+	public const CALENDAR_TYPE_FEDERATED = 2;
 
 	public const PERSONAL_CALENDAR_URI = 'personal';
 	public const PERSONAL_CALENDAR_NAME = 'Personal';
@@ -199,6 +204,8 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 	private string $dbObjectInvitationsTable = 'calendar_invitations';
 	private array $cachedObjects = [];
 
+	private readonly ICache $publishStatusCache;
+
 	public function __construct(
 		private IDBConnection $db,
 		private Principal $principalBackend,
@@ -208,8 +215,11 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 		private IEventDispatcher $dispatcher,
 		private IConfig $config,
 		private Sharing\Backend $calendarSharingBackend,
+		private FederatedCalendarMapper $federatedCalendarMapper,
+		ICacheFactory $cacheFactory,
 		private bool $legacyEndpoint = false,
 	) {
+		$this->publishStatusCache = $cacheFactory->createInMemory();
 	}
 
 	/**
@@ -535,7 +545,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 				'{' . Plugin::NS_CALDAV . '}supported-calendar-component-set' => new SupportedCalendarComponentSet($components),
 				'{' . Plugin::NS_CALDAV . '}schedule-calendar-transp' => new ScheduleCalendarTransp($row['transparent']?'transparent':'opaque'),
 				'{' . \OCA\DAV\DAV\Sharing\Plugin::NS_OWNCLOUD . '}owner-principal' => $this->convertPrincipal($row['principaluri'], $this->legacyEndpoint),
-				'{' . \OCA\DAV\DAV\Sharing\Plugin::NS_OWNCLOUD . '}read-only' => (int)$row['access'] === Backend::ACCESS_READ,
+				'{' . \OCA\DAV\DAV\Sharing\Plugin::NS_OWNCLOUD . '}read-only' => true,
 				'{' . \OCA\DAV\DAV\Sharing\Plugin::NS_OWNCLOUD . '}public' => (int)$row['access'] === self::ACCESS_PUBLIC,
 			];
 
@@ -600,7 +610,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 			'{' . Plugin::NS_CALDAV . '}supported-calendar-component-set' => new SupportedCalendarComponentSet($components),
 			'{' . Plugin::NS_CALDAV . '}schedule-calendar-transp' => new ScheduleCalendarTransp($row['transparent']?'transparent':'opaque'),
 			'{' . \OCA\DAV\DAV\Sharing\Plugin::NS_OWNCLOUD . '}owner-principal' => $this->convertPrincipal($row['principaluri'], !$this->legacyEndpoint),
-			'{' . \OCA\DAV\DAV\Sharing\Plugin::NS_OWNCLOUD . '}read-only' => (int)$row['access'] === Backend::ACCESS_READ,
+			'{' . \OCA\DAV\DAV\Sharing\Plugin::NS_OWNCLOUD . '}read-only' => true,
 			'{' . \OCA\DAV\DAV\Sharing\Plugin::NS_OWNCLOUD . '}public' => (int)$row['access'] === self::ACCESS_PUBLIC,
 		];
 
@@ -919,6 +929,8 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 	 * @return void
 	 */
 	public function deleteCalendar($calendarId, bool $forceDeletePermanently = false) {
+		$this->publishStatusCache->remove((string)$calendarId);
+
 		$this->atomic(function () use ($calendarId, $forceDeletePermanently): void {
 			// The calendar is deleted right away if this is either enforced by the caller
 			// or the special contacts birthday calendar or when the preference of an empty
@@ -1408,10 +1420,12 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 				$shares = $this->getShares($calendarId);
 
 				$this->dispatcher->dispatchTyped(new CalendarObjectCreatedEvent($calendarId, $calendarRow, $shares, $objectRow));
-			} else {
+			} elseif ($calendarType === self::CALENDAR_TYPE_SUBSCRIPTION) {
 				$subscriptionRow = $this->getSubscriptionById($calendarId);
 
 				$this->dispatcher->dispatchTyped(new CachedCalendarObjectCreatedEvent($calendarId, $subscriptionRow, [], $objectRow));
+			} elseif ($calendarType === self::CALENDAR_TYPE_FEDERATED) {
+				// TODO: implement custom event for federated calendars
 			}
 
 			return '"' . $extraData['etag'] . '"';
@@ -1468,10 +1482,12 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 					$shares = $this->getShares($calendarId);
 
 					$this->dispatcher->dispatchTyped(new CalendarObjectUpdatedEvent($calendarId, $calendarRow, $shares, $objectRow));
-				} else {
+				} elseif ($calendarType === self::CALENDAR_TYPE_SUBSCRIPTION) {
 					$subscriptionRow = $this->getSubscriptionById($calendarId);
 
 					$this->dispatcher->dispatchTyped(new CachedCalendarObjectUpdatedEvent($calendarId, $subscriptionRow, [], $objectRow));
+				} elseif ($calendarType === self::CALENDAR_TYPE_FEDERATED) {
+					// TODO: implement custom event for federated calendars
 				}
 			}
 
@@ -1978,6 +1994,8 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 
 		if (isset($calendarInfo['source'])) {
 			$calendarType = self::CALENDAR_TYPE_SUBSCRIPTION;
+		} elseif (isset($calendarInfo['federated'])) {
+			$calendarType = self::CALENDAR_TYPE_FEDERATED;
 		} else {
 			$calendarType = self::CALENDAR_TYPE_CALENDAR;
 		}
@@ -2424,7 +2442,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 	 * @param string $uid
 	 * @return string|null
 	 */
-	public function getCalendarObjectByUID($principalUri, $uid) {
+	public function getCalendarObjectByUID($principalUri, $uid, $calendarUri = null) {
 		$query = $this->db->getQueryBuilder();
 		$query->selectAlias('c.uri', 'calendaruri')->selectAlias('co.uri', 'objecturi')
 			->from('calendarobjects', 'co')
@@ -2432,6 +2450,11 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 			->where($query->expr()->eq('c.principaluri', $query->createNamedParameter($principalUri)))
 			->andWhere($query->expr()->eq('co.uid', $query->createNamedParameter($uid)))
 			->andWhere($query->expr()->isNull('co.deleted_at'));
+
+		if ($calendarUri !== null) {
+			$query->andWhere($query->expr()->eq('c.uri', $query->createNamedParameter($calendarUri)));
+		}
+
 		$stmt = $query->executeQuery();
 		$row = $stmt->fetch();
 		$stmt->closeCursor();
@@ -3192,6 +3215,10 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 		return $this->calendarSharingBackend->getShares($resourceId);
 	}
 
+	public function getSharesByShareePrincipal(string $principal): array {
+		return $this->calendarSharingBackend->getSharesByShareePrincipal($principal);
+	}
+
 	public function preloadShares(array $resourceIds): void {
 		$this->calendarSharingBackend->preloadShares($resourceIds);
 	}
@@ -3202,7 +3229,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 	 * @return string|null
 	 */
 	public function setPublishStatus($value, $calendar) {
-		return $this->atomic(function () use ($value, $calendar) {
+		$publishStatus = $this->atomic(function () use ($value, $calendar) {
 			$calendarId = $calendar->getResourceId();
 			$calendarData = $this->getCalendarById($calendarId);
 
@@ -3230,13 +3257,21 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 			$this->dispatcher->dispatchTyped(new CalendarUnpublishedEvent($calendarId, $calendarData));
 			return null;
 		}, $this->db);
+
+		$this->publishStatusCache->set((string)$calendar->getResourceId(), $publishStatus ?? false);
+		return $publishStatus;
 	}
 
 	/**
 	 * @param Calendar $calendar
-	 * @return mixed
+	 * @return string|false
 	 */
 	public function getPublishStatus($calendar) {
+		$cached = $this->publishStatusCache->get((string)$calendar->getResourceId());
+		if ($cached !== null) {
+			return $cached;
+		}
+
 		$query = $this->db->getQueryBuilder();
 		$result = $query->select('publicuri')
 			->from('dav_shares')
@@ -3244,9 +3279,46 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 			->andWhere($query->expr()->eq('access', $query->createNamedParameter(self::ACCESS_PUBLIC)))
 			->executeQuery();
 
-		$row = $result->fetch();
+		$publishStatus = $result->fetchOne();
+		$result->closeCursor();
+
+		$this->publishStatusCache->set((string)$calendar->getResourceId(), $publishStatus);
+		return $publishStatus;
+	}
+
+	/**
+	 * @param int[] $resourceIds
+	 */
+	public function preloadPublishStatuses(array $resourceIds): void {
+		$query = $this->db->getQueryBuilder();
+		$result = $query->select('resourceid', 'publicuri')
+			->from('dav_shares')
+			->where($query->expr()->in(
+				'resourceid',
+				$query->createNamedParameter($resourceIds, IQueryBuilder::PARAM_INT_ARRAY),
+				IQueryBuilder::PARAM_INT_ARRAY,
+			))
+			->andWhere($query->expr()->eq(
+				'access',
+				$query->createNamedParameter(self::ACCESS_PUBLIC, IQueryBuilder::PARAM_INT),
+				IQueryBuilder::PARAM_INT,
+			))
+			->executeQuery();
+
+		$hasPublishStatuses = [];
+		while ($row = $result->fetch()) {
+			$this->publishStatusCache->set((string)$row['resourceid'], $row['publicuri']);
+			$hasPublishStatuses[(int)$row['resourceid']] = true;
+		}
+
+		// Also remember resources with no publish status
+		foreach ($resourceIds as $resourceId) {
+			if (!isset($hasPublishStatuses[$resourceId])) {
+				$this->publishStatusCache->set((string)$resourceId, false);
+			}
+		}
+
 		$result->closeCursor();
-		return $row ? reset($row) : false;
 	}
 
 	/**
@@ -3565,7 +3637,9 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 			$uri = $calendarInfo['principaluri'];
 		}
 
-		$principalInformation = $this->principalBackend->getPrincipalByPath($uri);
+		$principalInformation = $this->principalBackend->getPrincipalPropertiesByPath($uri, [
+			'{DAV:}displayname',
+		]);
 		if (isset($principalInformation['{DAV:}displayname'])) {
 			$calendarInfo[$displaynameKey] = $principalInformation['{DAV:}displayname'];
 		}
@@ -3687,4 +3761,20 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 			}
 		}, $this->db);
 	}
+
+	/**
+	 * @return array<string, mixed>[]
+	 */
+	public function getFederatedCalendarsForUser(string $principalUri): array {
+		$federatedCalendars = $this->federatedCalendarMapper->findByPrincipalUri($principalUri);
+		return array_map(
+			static fn (FederatedCalendarEntity $entity) => $entity->toCalendarInfo(),
+			$federatedCalendars,
+		);
+	}
+
+	public function getFederatedCalendarByUri(string $principalUri, string $uri): ?array {
+		$federatedCalendar = $this->federatedCalendarMapper->findByUri($principalUri, $uri);
+		return $federatedCalendar?->toCalendarInfo();
+	}
 }

apps/dav/lib/CalDAV/Calendar.php

@@ -64,6 +64,10 @@ class Calendar extends \Sabre\CalDAV\Calendar implements IRestorable, IShareable
 		return $this->calendarInfo['uri'];
 	}
 
+	protected function getCalendarType(): int {
+		return CalDavBackend::CALENDAR_TYPE_CALENDAR;
+	}
+
 	/**
 	 * {@inheritdoc}
 	 * @throws Forbidden
@@ -197,7 +201,7 @@ class Calendar extends \Sabre\CalDAV\Calendar implements IRestorable, IShareable
 			$this->getOwner() . '/calendar-proxy-read',
 			$this->getOwner() . '/calendar-proxy-write',
 			parent::getOwner(),
-			'principals/system/public'
+			'principals/system/public',
 		];
 		/** @var list<array{privilege: string, principal: string, protected: bool}> $acl */
 		$acl = array_filter($acl, function (array $rule) use ($allowedPrincipals): bool {
@@ -247,7 +251,7 @@ class Calendar extends \Sabre\CalDAV\Calendar implements IRestorable, IShareable
 	}
 
 	public function getChild($name) {
-		$obj = $this->caldavBackend->getCalendarObject($this->calendarInfo['id'], $name);
+		$obj = $this->caldavBackend->getCalendarObject($this->calendarInfo['id'], $name, $this->getCalendarType());
 
 		if (!$obj) {
 			throw new NotFound('Calendar object not found');
@@ -263,7 +267,7 @@ class Calendar extends \Sabre\CalDAV\Calendar implements IRestorable, IShareable
 	}
 
 	public function getChildren() {
-		$objs = $this->caldavBackend->getCalendarObjects($this->calendarInfo['id']);
+		$objs = $this->caldavBackend->getCalendarObjects($this->calendarInfo['id'], $this->getCalendarType());
 		$children = [];
 		foreach ($objs as $obj) {
 			if ($obj['classification'] === CalDavBackend::CLASSIFICATION_PRIVATE && $this->isShared()) {
@@ -276,7 +280,7 @@ class Calendar extends \Sabre\CalDAV\Calendar implements IRestorable, IShareable
 	}
 
 	public function getMultipleChildren(array $paths) {
-		$objs = $this->caldavBackend->getMultipleCalendarObjects($this->calendarInfo['id'], $paths);
+		$objs = $this->caldavBackend->getMultipleCalendarObjects($this->calendarInfo['id'], $paths, $this->getCalendarType());
 		$children = [];
 		foreach ($objs as $obj) {
 			if ($obj['classification'] === CalDavBackend::CLASSIFICATION_PRIVATE && $this->isShared()) {
@@ -289,7 +293,7 @@ class Calendar extends \Sabre\CalDAV\Calendar implements IRestorable, IShareable
 	}
 
 	public function childExists($name) {
-		$obj = $this->caldavBackend->getCalendarObject($this->calendarInfo['id'], $name);
+		$obj = $this->caldavBackend->getCalendarObject($this->calendarInfo['id'], $name, $this->getCalendarType());
 		if (!$obj) {
 			return false;
 		}
@@ -301,7 +305,7 @@ class Calendar extends \Sabre\CalDAV\Calendar implements IRestorable, IShareable
 	}
 
 	public function calendarQuery(array $filters) {
-		$uris = $this->caldavBackend->calendarQuery($this->calendarInfo['id'], $filters);
+		$uris = $this->caldavBackend->calendarQuery($this->calendarInfo['id'], $filters, $this->getCalendarType());
 		if ($this->isShared()) {
 			return array_filter($uris, function ($uri) {
 				return $this->childExists($uri);

apps/dav/lib/CalDAV/CalendarHome.php

@@ -8,6 +8,7 @@
 namespace OCA\DAV\CalDAV;
 
 use OCA\DAV\AppInfo\PluginManager;
+use OCA\DAV\CalDAV\Federation\FederatedCalendarFactory;
 use OCA\DAV\CalDAV\Integration\ExternalCalendar;
 use OCA\DAV\CalDAV\Integration\ICalendarProvider;
 use OCA\DAV\CalDAV\Trashbin\TrashbinHome;
@@ -37,12 +38,14 @@ class CalendarHome extends \Sabre\CalDAV\CalendarHome {
 
 	/** @var PluginManager */
 	private $pluginManager;
+
 	private ?array $cachedChildren = null;
 
 	public function __construct(
 		BackendInterface $caldavBackend,
 		array $principalInfo,
 		private LoggerInterface $logger,
+		private FederatedCalendarFactory $federatedCalendarFactory,
 		private bool $returnCachedSubscriptions,
 	) {
 		parent::__construct($caldavBackend, $principalInfo);
@@ -102,6 +105,15 @@ class CalendarHome extends \Sabre\CalDAV\CalendarHome {
 
 		if ($this->caldavBackend instanceof CalDavBackend) {
 			$objects[] = new TrashbinHome($this->caldavBackend, $this->principalInfo);
+
+			$federatedCalendars = $this->caldavBackend->getFederatedCalendarsForUser(
+				$this->principalInfo['uri'],
+			);
+			foreach ($federatedCalendars as $federatedCalendarInfo) {
+				$objects[] = $this->federatedCalendarFactory->createFederatedCalendar(
+					$federatedCalendarInfo,
+				);
+			}
 		}
 
 		// If the backend supports subscriptions, we'll add those as well,
@@ -147,13 +159,22 @@ class CalendarHome extends \Sabre\CalDAV\CalendarHome {
 			return new TrashbinHome($this->caldavBackend, $this->principalInfo);
 		}
 
-		// Calendar - this covers all "regular" calendars, but not shared
-		// only check if the method is available
+		// Only check if the methods are available
 		if ($this->caldavBackend instanceof CalDavBackend) {
+			// Calendar - this covers all "regular" calendars, but not shared
 			$calendar = $this->caldavBackend->getCalendarByUri($this->principalInfo['uri'], $name);
 			if (!empty($calendar)) {
 				return new Calendar($this->caldavBackend, $calendar, $this->l10n, $this->config, $this->logger);
 			}
+
+			// Federated calendar
+			$federatedCalendar = $this->caldavBackend->getFederatedCalendarByUri(
+				$this->principalInfo['uri'],
+				$name,
+			);
+			if ($federatedCalendar !== null) {
+				return $this->federatedCalendarFactory->createFederatedCalendar($federatedCalendar);
+			}
 		}
 
 		// Fallback to cover shared calendars

apps/dav/lib/CalDAV/CalendarImpl.php

@@ -11,6 +11,7 @@ namespace OCA\DAV\CalDAV;
 use Generator;
 use OCA\DAV\CalDAV\Auth\CustomPrincipalPlugin;
 use OCA\DAV\CalDAV\InvitationResponse\InvitationResponseServer;
+use OCA\DAV\Connector\Sabre\Server;
 use OCP\Calendar\CalendarExportOptions;
 use OCP\Calendar\Exceptions\CalendarException;
 use OCP\Calendar\ICalendarExport;
@@ -23,11 +24,12 @@ use OCP\Constants;
 use Sabre\CalDAV\Xml\Property\ScheduleCalendarTransp;
 use Sabre\DAV\Exception\Conflict;
 use Sabre\VObject\Component\VCalendar;
-use Sabre\VObject\Component\VEvent;
 use Sabre\VObject\Component\VTimeZone;
 use Sabre\VObject\ITip\Message;
+use Sabre\VObject\ParseException;
 use Sabre\VObject\Property;
 use Sabre\VObject\Reader;
+
 use function Sabre\Uri\split as uriSplit;
 
 class CalendarImpl implements ICreateFromString, IHandleImipMessage, ICalendarIsWritable, ICalendarIsShared, ICalendarExport, ICalendarIsEnabled {
@@ -39,6 +41,9 @@ class CalendarImpl implements ICreateFromString, IHandleImipMessage, ICalendarIs
 	) {
 	}
 
+	private const DAV_PROPERTY_USER_ADDRESS = '{http://sabredav.org/ns}email-address';
+	private const DAV_PROPERTY_USER_ADDRESSES = '{urn:ietf:params:xml:ns:caldav}calendar-user-address-set';
+
 	/**
 	 * @return string defining the technical unique key
 	 * @since 13.0.0
@@ -54,6 +59,14 @@ class CalendarImpl implements ICreateFromString, IHandleImipMessage, ICalendarIs
 		return $this->calendarInfo['uri'];
 	}
 
+	/**
+	 * @return string the principal URI of the calendar owner
+	 * @since 32.0.0
+	 */
+	public function getPrincipalUri(): string {
+		return $this->calendarInfo['principaluri'];
+	}
+
 	/**
 	 * In comparison to getKey() this function returns a human readable (maybe translated) name
 	 * @since 13.0.0
@@ -161,7 +174,7 @@ class CalendarImpl implements ICreateFromString, IHandleImipMessage, ICalendarIs
 	private function createFromStringInServer(
 		string $name,
 		string $calendarData,
-		\OCA\DAV\Connector\Sabre\Server $server,
+		Server $server,
 	): void {
 		/** @var CustomPrincipalPlugin $plugin */
 		$plugin = $server->getPlugin('auth');
@@ -209,58 +222,93 @@ class CalendarImpl implements ICreateFromString, IHandleImipMessage, ICalendarIs
 	 * @throws CalendarException
 	 */
 	public function handleIMipMessage(string $name, string $calendarData): void {
-		$server = $this->getInvitationResponseServer();
-
-		/** @var CustomPrincipalPlugin $plugin */
-		$plugin = $server->getServer()->getPlugin('auth');
-		// we're working around the previous implementation
-		// that only allowed the public system principal to be used
-		// so set the custom principal here
-		$plugin->setCurrentPrincipal($this->calendar->getPrincipalURI());
 
+		try {
+			/** @var VCalendar $vObject|null */
+			$vObject = Reader::read($calendarData);
+		} catch (ParseException $e) {
+			throw new CalendarException('iMip message could not be processed because an error occurred while parsing the iMip message', 0, $e);
+		}
+		// validate the iMip message
+		if (!isset($vObject->METHOD)) {
+			throw new CalendarException('iMip message contains no valid method');
+		}
+		if (!isset($vObject->VEVENT)) {
+			throw new CalendarException('iMip message contains no event');
+		}
+		if (!isset($vObject->VEVENT->UID)) {
+			throw new CalendarException('iMip message event dose not contain a UID');
+		}
+		if (!isset($vObject->VEVENT->ORGANIZER)) {
+			throw new CalendarException('iMip message event dose not contain an organizer');
+		}
+		if (!isset($vObject->VEVENT->ATTENDEE)) {
+			throw new CalendarException('iMip message event dose not contain an attendee');
+		}
 		if (empty($this->calendarInfo['uri'])) {
 			throw new CalendarException('Could not write to calendar as URI parameter is missing');
 		}
-		// Force calendar change URI
-		/** @var Schedule\Plugin $schedulingPlugin */
-		$schedulingPlugin = $server->getServer()->getPlugin('caldav-schedule');
-		// Let sabre handle the rest
-		$iTipMessage = new Message();
-		/** @var VCalendar $vObject */
-		$vObject = Reader::read($calendarData);
-		/** @var VEvent $vEvent */
-		$vEvent = $vObject->{'VEVENT'};
-
-		if ($vObject->{'METHOD'} === null) {
-			throw new CalendarException('No Method provided for scheduling data. Could not process message');
-		}
-
-		if (!isset($vEvent->{'ORGANIZER'}) || !isset($vEvent->{'ATTENDEE'})) {
-			throw new CalendarException('Could not process scheduling data, neccessary data missing from ICAL');
-		}
-		$organizer = $vEvent->{'ORGANIZER'}->getValue();
-		$attendee = $vEvent->{'ATTENDEE'}->getValue();
-
-		$iTipMessage->method = $vObject->{'METHOD'}->getValue();
-		if ($iTipMessage->method === 'REQUEST') {
-			$iTipMessage->sender = $organizer;
-			$iTipMessage->recipient = $attendee;
-		} elseif ($iTipMessage->method === 'REPLY') {
-			if ($server->isExternalAttendee($vEvent->{'ATTENDEE'}->getValue())) {
-				$iTipMessage->recipient = $organizer;
-			} else {
-				$iTipMessage->recipient = $attendee;
+		// construct dav server
+		$server = $this->getInvitationResponseServer();
+		/** @var CustomPrincipalPlugin $authPlugin */
+		$authPlugin = $server->getServer()->getPlugin('auth');
+		// we're working around the previous implementation
+		// that only allowed the public system principal to be used
+		// so set the custom principal here
+		$authPlugin->setCurrentPrincipal($this->calendar->getPrincipalURI());
+		// retrieve all users addresses
+		$userProperties = $server->getServer()->getProperties($this->calendar->getPrincipalURI(), [ self::DAV_PROPERTY_USER_ADDRESS, self::DAV_PROPERTY_USER_ADDRESSES ]);
+		$userAddress = 'mailto:' . ($userProperties[self::DAV_PROPERTY_USER_ADDRESS] ?? null);
+		$userAddresses = $userProperties[self::DAV_PROPERTY_USER_ADDRESSES]->getHrefs() ?? [];
+		$userAddresses = array_map('strtolower', array_map('urldecode', $userAddresses));
+		// validate the method, recipient and sender
+		$imipMethod = strtoupper($vObject->METHOD->getValue());
+		if (in_array($imipMethod, ['REPLY', 'REFRESH'], true)) {
+			// extract sender (REPLY and REFRESH method should only have one attendee)
+			$sender = strtolower($vObject->VEVENT->ATTENDEE->getValue());
+			// extract and verify the recipient
+			$recipient = strtolower($vObject->VEVENT->ORGANIZER->getValue());
+			if (!in_array($recipient, $userAddresses, true)) {
+				throw new CalendarException('iMip message dose not contain an organizer that matches the user');
 			}
-			$iTipMessage->sender = $attendee;
-		} elseif ($iTipMessage->method === 'CANCEL') {
-			$iTipMessage->recipient = $attendee;
-			$iTipMessage->sender = $organizer;
+			// if the recipient address is not the same as the user address this means an alias was used
+			// the iTip broker uses the users primary email address during processing
+			if ($userAddress !== $recipient) {
+				$recipient = $userAddress;
+			}
+		} elseif (in_array($imipMethod, ['PUBLISH', 'REQUEST', 'ADD', 'CANCEL'], true)) {
+			// extract sender
+			$sender = strtolower($vObject->VEVENT->ORGANIZER->getValue());
+			// extract and verify the recipient
+			foreach ($vObject->VEVENT->ATTENDEE as $attendee) {
+				$recipient = strtolower($attendee->getValue());
+				if (in_array($recipient, $userAddresses, true)) {
+					break;
+				}
+				$recipient = null;
+			}
+			if ($recipient === null) {
+				throw new CalendarException('iMip message dose not contain an attendee that matches the user');
+			}
+			// if the recipient address is not the same as the user address this means an alias was used
+			// the iTip broker uses the users primary email address during processing
+			if ($userAddress !== $recipient) {
+				$recipient = $userAddress;
+			}
+		} else {
+			throw new CalendarException('iMip message contains a method that is not supported: ' . $imipMethod);
 		}
-		$iTipMessage->uid = isset($vEvent->{'UID'}) ? $vEvent->{'UID'}->getValue() : '';
-		$iTipMessage->component = 'VEVENT';
-		$iTipMessage->sequence = isset($vEvent->{'SEQUENCE'}) ? (int)$vEvent->{'SEQUENCE'}->getValue() : 0;
-		$iTipMessage->message = $vObject;
-		$server->server->emit('schedule', [$iTipMessage]);
+		// generate the iTip message
+		$iTip = new Message();
+		$iTip->method = $imipMethod;
+		$iTip->sender = $sender;
+		$iTip->recipient = $recipient;
+		$iTip->component = 'VEVENT';
+		$iTip->uid = $vObject->VEVENT->UID->getValue();
+		$iTip->sequence = isset($vObject->VEVENT->SEQUENCE) ? (int)$vObject->VEVENT->SEQUENCE->getValue() : 1;
+		$iTip->message = $vObject;
+
+		$server->server->emit('schedule', [$iTip]);
 	}
 
 	public function getInvitationResponseServer(): InvitationResponseServer {

apps/dav/lib/CalDAV/CalendarObject.php

@@ -53,7 +53,8 @@ class CalendarObject extends \Sabre\CalDAV\CalendarObject {
 		}
 
 		// shows as busy if event is declared confidential
-		if ($this->objectData['classification'] === CalDavBackend::CLASSIFICATION_CONFIDENTIAL) {
+		if ($this->objectData['classification'] === CalDavBackend::CLASSIFICATION_CONFIDENTIAL
+			&& ($this->isPublic() || !$this->canWrite())) {
 			$this->createConfidentialObject($vObject);
 		}
 
@@ -135,6 +136,10 @@ class CalendarObject extends \Sabre\CalDAV\CalendarObject {
 		return true;
 	}
 
+	private function isPublic(): bool {
+		return $this->calendarInfo['{http://owncloud.org/ns}public'] ?? false;
+	}
+
 	public function getCalendarId(): int {
 		return (int)$this->objectData['calendarid'];
 	}

apps/dav/lib/CalDAV/CalendarProvider.php

@@ -8,6 +8,7 @@ declare(strict_types=1);
  */
 namespace OCA\DAV\CalDAV;
 
+use OCA\DAV\CalDAV\Federation\FederatedCalendarImpl;
 use OCA\DAV\Db\Property;
 use OCA\DAV\Db\PropertyMapper;
 use OCP\Calendar\ICalendarProvider;
@@ -27,17 +28,24 @@ class CalendarProvider implements ICalendarProvider {
 	}
 
 	public function getCalendars(string $principalUri, array $calendarUris = []): array {
-
+		/** @var array{uri: string, principaluri: string}[] $calendarInfos */
 		$calendarInfos = $this->calDavBackend->getCalendarsForUser($principalUri) ?? [];
+		/** @var array{uri: string, principaluri: string}[] $federatedCalendarInfos */
+		$federatedCalendarInfos = $this->calDavBackend->getFederatedCalendarsForUser($principalUri);
 
 		if (!empty($calendarUris)) {
 			$calendarInfos = array_filter($calendarInfos, function ($calendar) use ($calendarUris) {
 				return in_array($calendar['uri'], $calendarUris);
 			});
+
+			$federatedCalendarInfos = array_filter($federatedCalendarInfos, function ($federatedCalendar) use ($calendarUris) {
+				return in_array($federatedCalendar['uri'], $calendarUris);
+			});
 		}
 
 		$additionalProperties = $this->getAdditionalPropertiesForCalendars($calendarInfos);
 		$iCalendars = [];
+
 		foreach ($calendarInfos as $calendarInfo) {
 			$user = str_replace('principals/users/', '', $calendarInfo['principaluri']);
 			$path = 'calendars/' . $user . '/' . $calendarInfo['uri'];
@@ -51,6 +59,20 @@ class CalendarProvider implements ICalendarProvider {
 				$this->calDavBackend,
 			);
 		}
+
+		$additionalFederatedProps = $this->getAdditionalPropertiesForCalendars(
+			$federatedCalendarInfos,
+		);
+		foreach ($federatedCalendarInfos as $calendarInfo) {
+			$user = str_replace('principals/users/', '', $calendarInfo['principaluri']);
+			$path = 'calendars/' . $user . '/' . $calendarInfo['uri'];
+			if (isset($additionalFederatedProps[$path])) {
+				$calendarInfo = array_merge($calendarInfo, $additionalProperties[$path]);
+			}
+
+			$iCalendars[] = new FederatedCalendarImpl($calendarInfo, $this->calDavBackend);
+		}
+
 		return $iCalendars;
 	}
 

apps/dav/lib/CalDAV/CalendarRoot.php

@@ -7,8 +7,15 @@
  */
 namespace OCA\DAV\CalDAV;
 
+use OCA\DAV\CalDAV\Federation\FederatedCalendarFactory;
+use OCA\DAV\CalDAV\Federation\RemoteUserCalendarHome;
+use OCA\DAV\Connector\Sabre\Principal;
+use OCA\DAV\DAV\RemoteUserPrincipalBackend;
+use OCP\IConfig;
+use OCP\IL10N;
 use Psr\Log\LoggerInterface;
 use Sabre\CalDAV\Backend;
+use Sabre\DAV\Exception\NotFound;
 use Sabre\DAVACL\PrincipalBackend;
 
 class CalendarRoot extends \Sabre\CalDAV\CalendarRoot {
@@ -19,15 +26,30 @@ class CalendarRoot extends \Sabre\CalDAV\CalendarRoot {
 		Backend\BackendInterface $caldavBackend,
 		$principalPrefix,
 		private LoggerInterface $logger,
+		private IL10N $l10n,
+		private IConfig $config,
+		private FederatedCalendarFactory $federatedCalendarFactory,
 	) {
 		parent::__construct($principalBackend, $caldavBackend, $principalPrefix);
 	}
 
 	public function getChildForPrincipal(array $principal) {
+		[$prefix] = \Sabre\Uri\split($principal['uri']);
+		if ($prefix === RemoteUserPrincipalBackend::PRINCIPAL_PREFIX) {
+			return new RemoteUserCalendarHome(
+				$this->caldavBackend,
+				$principal,
+				$this->l10n,
+				$this->config,
+				$this->logger,
+			);
+		}
+
 		return new CalendarHome(
 			$this->caldavBackend,
 			$principal,
 			$this->logger,
+			$this->federatedCalendarFactory,
 			array_key_exists($principal['uri'], $this->returnCachedSubscriptions)
 		);
 	}
@@ -40,10 +62,35 @@ class CalendarRoot extends \Sabre\CalDAV\CalendarRoot {
 			return $parts[1];
 		}
 
+		if ($this->principalPrefix === RemoteUserPrincipalBackend::PRINCIPAL_PREFIX) {
+			return 'remote-calendars';
+		}
+
 		return parent::getName();
 	}
 
 	public function enableReturnCachedSubscriptions(string $principalUri): void {
 		$this->returnCachedSubscriptions['principals/users/' . $principalUri] = true;
 	}
+
+	public function childExists($name) {
+		if (!($this->principalBackend instanceof Principal)) {
+			return parent::childExists($name);
+		}
+
+		// Fetch the most shallow version of the principal just to determine if it exists
+		$principalInfo = $this->principalBackend->getPrincipalPropertiesByPath(
+			$this->principalPrefix . '/' . $name,
+			[],
+		);
+		if ($principalInfo === null) {
+			return false;
+		}
+
+		try {
+			return $this->getChildForPrincipal($principalInfo) !== null;
+		} catch (NotFound $e) {
+			return false;
+		}
+	}
 }

apps/dav/lib/CalDAV/EmbeddedCalDavServer.php

@@ -13,6 +13,7 @@ use OCA\DAV\AppInfo\PluginManager;
 use OCA\DAV\CalDAV\Auth\CustomPrincipalPlugin;
 use OCA\DAV\CalDAV\Auth\PublicPrincipalPlugin;
 use OCA\DAV\CalDAV\Publishing\PublishPlugin;
+use OCA\DAV\CalDAV\Schedule\IMipPlugin;
 use OCA\DAV\Connector\Sabre\AnonymousOptionsPlugin;
 use OCA\DAV\Connector\Sabre\BlockLegacyClientPlugin;
 use OCA\DAV\Connector\Sabre\CachingTree;
@@ -94,7 +95,7 @@ class EmbeddedCalDavServer {
 			Server::get(IURLGenerator::class)
 		));
 		if ($appConfig->getValueString('dav', 'sendInvitations', 'yes') === 'yes') {
-			$this->server->addPlugin(Server::get(\OCA\DAV\CalDAV\Schedule\IMipPlugin::class));
+			$this->server->addPlugin(Server::get(IMipPlugin::class));
 		}
 
 		// collection preload plugin

apps/dav/lib/CalDAV/Federation/CalendarFederationConfig.php

@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\CalDAV\Federation;
+
+use OCP\AppFramework\Services\IAppConfig;
+
+class CalendarFederationConfig {
+	public function __construct(
+		private readonly IAppConfig $appConfig,
+	) {
+	}
+
+	public function isFederationEnabled(): bool {
+		return $this->appConfig->getAppValueBool('enableCalendarFederation', true);
+	}
+}

apps/dav/lib/CalDAV/Federation/CalendarFederationNotifier.php

@@ -0,0 +1,68 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\CalDAV\Federation;
+
+use OCP\Federation\ICloudFederationFactory;
+use OCP\Federation\ICloudFederationProviderManager;
+use OCP\Federation\ICloudId;
+use OCP\Http\Client\IResponse;
+use OCP\IURLGenerator;
+use OCP\OCM\Exceptions\OCMProviderException;
+
+class CalendarFederationNotifier {
+	public const NOTIFICATION_SYNC_CALENDAR = 'SYNC_CALENDAR';
+
+	public const PROP_SYNC_CALENDAR_SHARE_WITH = 'shareWith';
+	public const PROP_SYNC_CALENDAR_CALENDAR_URL = 'calendarUrl';
+
+	public function __construct(
+		private readonly ICloudFederationFactory $federationFactory,
+		private readonly ICloudFederationProviderManager $federationManager,
+		private readonly IURLGenerator $url,
+	) {
+	}
+
+	/**
+	 * Notify a remote server to sync a calendar.
+	 *
+	 * @param ICloudId $shareWith The cloud id of the remote sharee.
+	 * @return IResponse
+	 *
+	 * @throws OCMProviderException If sending the notification fails.
+	 */
+	public function notifySyncCalendar(
+		ICloudId $shareWith,
+		string $calendarOwner,
+		string $calendarName,
+		string $sharedSecret,
+	): IResponse {
+		$sharedWithEncoded = base64_encode($shareWith->getId());
+		$relativeCalendarUrl = "remote-calendars/$sharedWithEncoded/{$calendarName}_shared_by_$calendarOwner";
+		$calendarUrl = $this->url->linkTo('', 'remote.php') . "/dav/$relativeCalendarUrl";
+		$calendarUrl = $this->url->getAbsoluteURL($calendarUrl);
+
+		$notification = $this->federationFactory->getCloudFederationNotification();
+		$notification->setMessage(
+			self::NOTIFICATION_SYNC_CALENDAR,
+			CalendarFederationProvider::CALENDAR_RESOURCE,
+			CalendarFederationProvider::PROVIDER_ID,
+			[
+				'sharedSecret' => $sharedSecret,
+				self::PROP_SYNC_CALENDAR_SHARE_WITH => $shareWith->getId(),
+				self::PROP_SYNC_CALENDAR_CALENDAR_URL => $calendarUrl,
+			],
+		);
+
+		return $this->federationManager->sendCloudNotification(
+			$shareWith->getRemote(),
+			$notification,
+		);
+	}
+}

apps/dav/lib/CalDAV/Federation/CalendarFederationProvider.php

@@ -0,0 +1,203 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\CalDAV\Federation;
+
+use OCA\DAV\BackgroundJob\FederatedCalendarSyncJob;
+use OCA\DAV\CalDAV\Federation\Protocol\CalendarFederationProtocolV1;
+use OCA\DAV\CalDAV\Federation\Protocol\ICalendarFederationProtocol;
+use OCA\DAV\DAV\Sharing\Backend as DavSharingBackend;
+use OCP\AppFramework\Http;
+use OCP\BackgroundJob\IJobList;
+use OCP\Constants;
+use OCP\Federation\Exceptions\BadRequestException;
+use OCP\Federation\Exceptions\ProviderCouldNotAddShareException;
+use OCP\Federation\ICloudFederationProvider;
+use OCP\Federation\ICloudFederationShare;
+use OCP\Federation\ICloudIdManager;
+use OCP\Share\Exceptions\ShareNotFound;
+use Psr\Log\LoggerInterface;
+
+class CalendarFederationProvider implements ICloudFederationProvider {
+	public const PROVIDER_ID = 'calendar';
+	public const CALENDAR_RESOURCE = 'calendar';
+	public const USER_SHARE_TYPE = 'user';
+
+	public function __construct(
+		private readonly LoggerInterface $logger,
+		private readonly FederatedCalendarMapper $federatedCalendarMapper,
+		private readonly CalendarFederationConfig $calendarFederationConfig,
+		private readonly IJobList $jobList,
+		private readonly ICloudIdManager $cloudIdManager,
+	) {
+	}
+
+	public function getShareType(): string {
+		return self::PROVIDER_ID;
+	}
+
+	public function shareReceived(ICloudFederationShare $share): string {
+		if (!$this->calendarFederationConfig->isFederationEnabled()) {
+			$this->logger->debug('Received a federation invite but federation is disabled');
+			throw new ProviderCouldNotAddShareException(
+				'Server does not support calendar federation',
+				'',
+				Http::STATUS_SERVICE_UNAVAILABLE,
+			);
+		}
+
+		if (!in_array($share->getShareType(), $this->getSupportedShareTypes(), true)) {
+			$this->logger->debug('Received a federation invite for invalid share type');
+			throw new ProviderCouldNotAddShareException(
+				'Support for sharing with non-users not implemented yet',
+				'',
+				Http::STATUS_NOT_IMPLEMENTED,
+			);
+			// TODO: Implement group shares
+		}
+
+		$rawProtocol = $share->getProtocol();
+		switch ($rawProtocol[ICalendarFederationProtocol::PROP_VERSION]) {
+			case CalendarFederationProtocolV1::VERSION:
+				try {
+					$protocol = CalendarFederationProtocolV1::parse($rawProtocol);
+				} catch (Protocol\CalendarProtocolParseException $e) {
+					throw new ProviderCouldNotAddShareException(
+						'Invalid protocol data (v1)',
+						'',
+						Http::STATUS_BAD_REQUEST,
+					);
+				}
+				$calendarUrl = $protocol->getUrl();
+				$displayName = $protocol->getDisplayName();
+				$color = $protocol->getColor();
+				$access = $protocol->getAccess();
+				$components = $protocol->getComponents();
+				break;
+			default:
+				throw new ProviderCouldNotAddShareException(
+					'Unknown protocol version',
+					'',
+					Http::STATUS_BAD_REQUEST,
+				);
+		}
+
+		if (!$calendarUrl || !$displayName) {
+			throw new ProviderCouldNotAddShareException(
+				'Incomplete protocol data',
+				'',
+				Http::STATUS_BAD_REQUEST,
+			);
+		}
+
+		// TODO: implement read-write sharing
+		$permissions = match ($access) {
+			DavSharingBackend::ACCESS_READ => Constants::PERMISSION_READ,
+			default => throw new ProviderCouldNotAddShareException(
+				"Unsupported access value: $access",
+				'',
+				Http::STATUS_BAD_REQUEST,
+			),
+		};
+
+		// The calendar uri is the local name of the calendar. As such it must not contain slashes.
+		// Just use the hashed url for simplicity here.
+		// Example: calendars/foo-bar-user/<calendar-uri>
+		$calendarUri = hash('md5', $calendarUrl);
+
+		$sharedWithPrincipal = 'principals/users/' . $share->getShareWith();
+
+		// Delete existing incoming federated share first
+		$this->federatedCalendarMapper->deleteByUri($sharedWithPrincipal, $calendarUri);
+
+		$calendar = new FederatedCalendarEntity();
+		$calendar->setPrincipaluri($sharedWithPrincipal);
+		$calendar->setUri($calendarUri);
+		$calendar->setRemoteUrl($calendarUrl);
+		$calendar->setDisplayName($displayName);
+		$calendar->setColor($color);
+		$calendar->setToken($share->getShareSecret());
+		$calendar->setSharedBy($share->getSharedBy());
+		$calendar->setSharedByDisplayName($share->getSharedByDisplayName());
+		$calendar->setPermissions($permissions);
+		$calendar->setComponents($components);
+		$calendar = $this->federatedCalendarMapper->insert($calendar);
+
+		$this->jobList->add(FederatedCalendarSyncJob::class, [
+			FederatedCalendarSyncJob::ARGUMENT_ID => $calendar->getId(),
+		]);
+
+		return (string)$calendar->getId();
+	}
+
+	public function notificationReceived(
+		$notificationType,
+		$providerId,
+		array $notification,
+	): array {
+		if ($providerId !== self::PROVIDER_ID) {
+			throw new BadRequestException(['providerId']);
+		}
+
+		switch ($notificationType) {
+			case CalendarFederationNotifier::NOTIFICATION_SYNC_CALENDAR:
+				return $this->handleSyncCalendarNotification($notification);
+			default:
+				return [];
+		}
+	}
+
+	/**
+	 * @return string[]
+	 */
+	public function getSupportedShareTypes(): array {
+		return [self::USER_SHARE_TYPE];
+	}
+
+	/**
+	 * @throws BadRequestException If notification props are missing.
+	 * @throws ShareNotFound If the notification is not related to a known share.
+	 */
+	private function handleSyncCalendarNotification(array $notification): array {
+		$sharedSecret = $notification['sharedSecret'];
+		$shareWithRaw = $notification[CalendarFederationNotifier::PROP_SYNC_CALENDAR_SHARE_WITH] ?? null;
+		$calendarUrl = $notification[CalendarFederationNotifier::PROP_SYNC_CALENDAR_CALENDAR_URL] ?? null;
+
+		if ($shareWithRaw === null || $shareWithRaw === '') {
+			throw new BadRequestException([CalendarFederationNotifier::PROP_SYNC_CALENDAR_SHARE_WITH]);
+		}
+
+		if ($calendarUrl === null || $calendarUrl === '') {
+			throw new BadRequestException([CalendarFederationNotifier::PROP_SYNC_CALENDAR_CALENDAR_URL]);
+		}
+
+		try {
+			$shareWith = $this->cloudIdManager->resolveCloudId($shareWithRaw);
+		} catch (\InvalidArgumentException $e) {
+			throw new ShareNotFound('Invalid sharee cloud id');
+		}
+
+		$calendars = $this->federatedCalendarMapper->findByRemoteUrl(
+			$calendarUrl,
+			'principals/users/' . $shareWith->getUser(),
+			$sharedSecret,
+		);
+		if (empty($calendars)) {
+			throw new ShareNotFound('Calendar is not shared with the sharee');
+		}
+
+		foreach ($calendars as $calendar) {
+			$this->jobList->add(FederatedCalendarSyncJob::class, [
+				FederatedCalendarSyncJob::ARGUMENT_ID => $calendar->getId(),
+			]);
+		}
+
+		return [];
+	}
+}

apps/dav/lib/CalDAV/Federation/FederatedCalendar.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\CalDAV\Federation;
+
+use OCA\DAV\CalDAV\CalDavBackend;
+use OCA\DAV\CalDAV\Calendar;
+use OCP\IConfig;
+use OCP\IL10N;
+use Psr\Log\LoggerInterface;
+use Sabre\CalDAV\Backend;
+
+class FederatedCalendar extends Calendar {
+	public function __construct(
+		Backend\BackendInterface $caldavBackend,
+		$calendarInfo,
+		IL10N $l10n,
+		IConfig $config,
+		LoggerInterface $logger,
+		private readonly FederatedCalendarMapper $federatedCalendarMapper,
+	) {
+		parent::__construct($caldavBackend, $calendarInfo, $l10n, $config, $logger);
+	}
+
+	public function delete() {
+		$this->federatedCalendarMapper->deleteById($this->getResourceId());
+	}
+
+	protected function getCalendarType(): int {
+		return CalDavBackend::CALENDAR_TYPE_FEDERATED;
+	}
+}

apps/dav/lib/CalDAV/Federation/FederatedCalendarAuth.php

@@ -0,0 +1,81 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\CalDAV\Federation;
+
+use OCA\DAV\DAV\RemoteUserPrincipalBackend;
+use OCA\DAV\DAV\Sharing\SharingMapper;
+use OCP\Defaults;
+use Sabre\DAV\Auth\Backend\BackendInterface;
+use Sabre\HTTP\Auth\Basic as BasicAuth;
+use Sabre\HTTP\RequestInterface;
+use Sabre\HTTP\ResponseInterface;
+
+class FederatedCalendarAuth implements BackendInterface {
+	private readonly string $realm;
+
+	public function __construct(
+		private readonly SharingMapper $sharingMapper,
+	) {
+		$defaults = new Defaults();
+		$this->realm = $defaults->getName();
+	}
+
+	/**
+	 * @return string|null A principal uri if the given combination of user and pass is valid and null otherwise.
+	 */
+	private function validateUserPass(
+		string $requestPath,
+		string $username,
+		string $password,
+	): ?string {
+		$remoteUserPrincipalUri = RemoteUserPrincipalBackend::PRINCIPAL_PREFIX . "/$username";
+		[, $remoteUserPrincipalId] = \Sabre\Uri\split($remoteUserPrincipalUri);
+
+		$rows = $this->sharingMapper->getSharedCalendarsForRemoteUser(
+			$remoteUserPrincipalUri,
+			$password,
+		);
+
+		// Is the requested calendar actually shared with the remote user?
+		foreach ($rows as $row) {
+			$ownerPrincipalUri = $row['principaluri'];
+			[, $ownerUserId] = \Sabre\Uri\split($ownerPrincipalUri);
+			$shareUri = $row['uri'] . '_shared_by_' . $ownerUserId;
+			if (str_starts_with($requestPath, "remote-calendars/$remoteUserPrincipalId/$shareUri")) {
+				// Yes? -> return early
+				return $remoteUserPrincipalUri;
+			}
+		}
+
+		return null;
+	}
+
+	public function check(RequestInterface $request, ResponseInterface $response): array {
+		if (!str_starts_with($request->getPath(), 'remote-calendars/')) {
+			return [false, 'This request is not for a federated calendar'];
+		}
+
+		$auth = new BasicAuth($this->realm, $request, $response);
+		$userpass = $auth->getCredentials();
+		if ($userpass === null || count($userpass) !== 2) {
+			return [false, "No 'Authorization: Basic' header found. Either the client didn't send one, or the server is misconfigured"];
+		}
+		$principal = $this->validateUserPass($request->getPath(), $userpass[0], $userpass[1]);
+		if ($principal === null) {
+			return [false, 'Username or password was incorrect'];
+		}
+
+		return [true, $principal];
+	}
+
+	public function challenge(RequestInterface $request, ResponseInterface $response): void {
+		// No special challenge is needed here
+	}
+}

apps/dav/lib/CalDAV/Federation/FederatedCalendarEntity.php

@@ -0,0 +1,101 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\CalDAV\Federation;
+
+use OCA\DAV\DAV\RemoteUserPrincipalBackend;
+use OCP\AppFramework\Db\Entity;
+use OCP\DB\Types;
+use Sabre\CalDAV\Xml\Property\SupportedCalendarComponentSet;
+
+/**
+ * @method string getPrincipaluri()
+ * @method void setPrincipaluri(string $principaluri)
+ * @method string getUri()
+ * @method void setUri(string $uri)
+ * @method string getDisplayName()
+ * @method void setDisplayName(string $displayName)
+ * @method string|null getColor()
+ * @method void setColor(string|null $color)
+ * @method int getPermissions()
+ * @method void setPermissions(int $permissions)
+ * @method int getSyncToken()
+ * @method void setSyncToken(int $syncToken)
+ * @method string getRemoteUrl()
+ * @method void setRemoteUrl(string $remoteUrl)
+ * @method string getToken()
+ * @method void setToken(string $token)
+ * @method int|null getLastSync()
+ * @method void setLastSync(int|null $lastSync)
+ * @method string getSharedBy()
+ * @method void setSharedBy(string $sharedBy)
+ * @method string getSharedByDisplayName()
+ * @method void setSharedByDisplayName(string $sharedByDisplayName)
+ * @method string getComponents()
+ * @method void setComponents(string $components)
+ */
+class FederatedCalendarEntity extends Entity {
+	protected string $principaluri = '';
+	protected string $uri = '';
+	protected string $displayName = '';
+	protected ?string $color = null;
+	protected int $permissions = 0;
+	protected int $syncToken = 0;
+	protected string $remoteUrl = '';
+	protected string $token = '';
+	protected ?int $lastSync = null;
+	protected string $sharedBy = '';
+	protected string $sharedByDisplayName = '';
+	protected string $components = '';
+
+	public function __construct() {
+		$this->addType('principaluri', Types::STRING);
+		$this->addType('uri', Types::STRING);
+		$this->addType('color', Types::STRING);
+		$this->addType('displayName', Types::STRING);
+		$this->addType('permissions', Types::INTEGER);
+		$this->addType('syncToken', Types::INTEGER);
+		$this->addType('remoteUrl', Types::STRING);
+		$this->addType('token', Types::STRING);
+		$this->addType('lastSync', Types::INTEGER);
+		$this->addType('sharedBy', Types::STRING);
+		$this->addType('sharedByDisplayName', Types::STRING);
+		$this->addType('components', Types::STRING);
+	}
+
+	public function getSyncTokenForSabre(): string {
+		return 'http://sabre.io/ns/sync/' . $this->getSyncToken();
+	}
+
+	public function getSharedByPrincipal(): string {
+		return RemoteUserPrincipalBackend::PRINCIPAL_PREFIX . '/' . base64_encode($this->getSharedBy());
+	}
+
+	public function getSupportedCalendarComponentSet(): SupportedCalendarComponentSet {
+		$components = explode(',', $this->getComponents());
+		return new SupportedCalendarComponentSet($components);
+	}
+
+	public function toCalendarInfo(): array {
+		return [
+			'id' => $this->getId(),
+			'uri' => $this->getUri(),
+			'principaluri' => $this->getPrincipaluri(),
+			'federated' => 1,
+
+			'{DAV:}displayname' => $this->getDisplayName(),
+			'{http://sabredav.org/ns}sync-token' => $this->getSyncToken(),
+			'{' . \Sabre\CalDAV\Plugin::NS_CALENDARSERVER . '}getctag' => $this->getSyncTokenForSabre(),
+			'{' . \Sabre\CalDAV\Plugin::NS_CALDAV . '}supported-calendar-component-set' => $this->getSupportedCalendarComponentSet(),
+			'{' . \OCA\DAV\DAV\Sharing\Plugin::NS_OWNCLOUD . '}owner-principal' => $this->getSharedByPrincipal(),
+			// TODO: implement read-write sharing
+			'{' . \OCA\DAV\DAV\Sharing\Plugin::NS_OWNCLOUD . '}read-only' => 1
+		];
+	}
+}

apps/dav/lib/CalDAV/Federation/FederatedCalendarFactory.php

@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\CalDAV\Federation;
+
+use OCA\DAV\AppInfo\Application;
+use OCA\DAV\CalDAV\CalDavBackend;
+use OCP\IConfig;
+use OCP\IL10N;
+use OCP\L10N\IFactory as IL10NFactory;
+use Psr\Log\LoggerInterface;
+
+class FederatedCalendarFactory {
+	private readonly IL10N $l10n;
+
+	public function __construct(
+		private readonly CalDavBackend $caldavBackend,
+		private readonly IConfig $config,
+		private readonly LoggerInterface $logger,
+		private readonly FederatedCalendarMapper $federatedCalendarMapper,
+		IL10NFactory $l10nFactory,
+	) {
+		$this->l10n = $l10nFactory->get(Application::APP_ID);
+	}
+
+	public function createFederatedCalendar(array $calendarInfo): FederatedCalendar {
+		return new FederatedCalendar(
+			$this->caldavBackend,
+			$calendarInfo,
+			$this->l10n,
+			$this->config,
+			$this->logger,
+			$this->federatedCalendarMapper,
+		);
+	}
+}

apps/dav/lib/CalDAV/Federation/FederatedCalendarImpl.php

@@ -0,0 +1,73 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\CalDAV\Federation;
+
+use OCA\DAV\CalDAV\CalDavBackend;
+use OCP\Calendar\ICalendar;
+use OCP\Calendar\ICalendarIsEnabled;
+use OCP\Calendar\ICalendarIsShared;
+use OCP\Calendar\ICalendarIsWritable;
+use OCP\Constants;
+
+class FederatedCalendarImpl implements ICalendar, ICalendarIsShared, ICalendarIsWritable, ICalendarIsEnabled {
+	public function __construct(
+		private readonly array $calendarInfo,
+		private readonly CalDavBackend $calDavBackend,
+	) {
+	}
+
+	public function getKey(): string {
+		return (string)$this->calendarInfo['id'];
+	}
+
+	public function getUri(): string {
+		return $this->calendarInfo['uri'];
+	}
+
+	public function getDisplayName(): ?string {
+		return $this->calendarInfo['{DAV:}displayname'];
+	}
+
+	public function getDisplayColor(): ?string {
+		return $this->calendarInfo['{http://apple.com/ns/ical/}calendar-color'];
+	}
+
+	public function search(string $pattern, array $searchProperties = [], array $options = [], ?int $limit = null, ?int $offset = null): array {
+		return $this->calDavBackend->search(
+			$this->calendarInfo,
+			$pattern,
+			$searchProperties,
+			$options,
+			$limit,
+			$offset,
+		);
+	}
+
+	public function getPermissions(): int {
+		// TODO: implement read-write sharing
+		return Constants::PERMISSION_READ;
+	}
+
+	public function isDeleted(): bool {
+		return false;
+	}
+
+	public function isShared(): bool {
+		return true;
+	}
+
+	public function isWritable(): bool {
+		return false;
+	}
+
+	public function isEnabled(): bool {
+		return $this->calendarInfo['{http://owncloud.org/ns}calendar-enabled'] ?? true;
+	}
+}

apps/dav/lib/CalDAV/Federation/FederatedCalendarMapper.php

@@ -0,0 +1,209 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\CalDAV\Federation;
+
+use OCP\AppFramework\Db\DoesNotExistException;
+use OCP\AppFramework\Db\MultipleObjectsReturnedException;
+use OCP\AppFramework\Db\QBMapper;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\IDBConnection;
+
+/** @template-extends QBMapper<FederatedCalendarEntity>  */
+class FederatedCalendarMapper extends QBMapper {
+	public const TABLE_NAME = 'calendars_federated';
+
+	public function __construct(
+		IDBConnection $db,
+		private readonly ITimeFactory $time,
+	) {
+		parent::__construct($db, self::TABLE_NAME, FederatedCalendarEntity::class);
+	}
+
+	/**
+	 * @throws DoesNotExistException If there is no federated calendar with the given id.
+	 */
+	public function find(int $id): FederatedCalendarEntity {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('*')
+			->from(self::TABLE_NAME)
+			->where($qb->expr()->eq(
+				'id',
+				$qb->createNamedParameter($id, IQueryBuilder::PARAM_INT),
+				IQueryBuilder::PARAM_INT,
+			));
+		return $this->findEntity($qb);
+	}
+
+	/**
+	 * @return FederatedCalendarEntity[]
+	 */
+	public function findByPrincipalUri(string $principalUri): array {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('*')
+			->from(self::TABLE_NAME)
+			->where($qb->expr()->eq(
+				'principaluri',
+				$qb->createNamedParameter($principalUri, IQueryBuilder::PARAM_STR),
+				IQueryBuilder::PARAM_STR,
+			));
+		return $this->findEntities($qb);
+	}
+
+	public function findByUri(string $principalUri, string $uri): ?FederatedCalendarEntity {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('*')
+			->from(self::TABLE_NAME)
+			->where($qb->expr()->eq(
+				'principaluri',
+				$qb->createNamedParameter($principalUri, IQueryBuilder::PARAM_STR),
+				IQueryBuilder::PARAM_STR,
+			))
+			->andWhere($qb->expr()->eq(
+				'uri',
+				$qb->createNamedParameter($uri, IQueryBuilder::PARAM_STR),
+				IQueryBuilder::PARAM_STR,
+			));
+
+		try {
+			return $this->findEntity($qb);
+		} catch (DoesNotExistException $e) {
+			return null;
+		} catch (MultipleObjectsReturnedException $e) {
+			// Should never happen
+			return null;
+		}
+	}
+
+	/**
+	 * @return FederatedCalendarEntity[]
+	 */
+	public function findUnsyncedSinceBefore(int $beforeTimestamp): array {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('*')
+			->from(self::TABLE_NAME)
+			->where($qb->expr()->lt(
+				'last_sync',
+				$qb->createNamedParameter($beforeTimestamp, IQueryBuilder::PARAM_INT),
+				IQueryBuilder::PARAM_INT,
+			))
+			// Omit unsynced calendars for now as they are synced by a separate job
+			->andWhere($qb->expr()->isNotNull('last_sync'));
+		return $this->findEntities($qb);
+	}
+
+	public function deleteById(int $id): void {
+		$qb = $this->db->getQueryBuilder();
+		$qb->delete(self::TABLE_NAME)
+			->where($qb->expr()->eq(
+				'id',
+				$qb->createNamedParameter($id, IQueryBuilder::PARAM_INT),
+				IQueryBuilder::PARAM_INT,
+			));
+		$qb->executeStatement();
+	}
+
+	public function updateSyncTime(int $id): void {
+		$now = $this->time->getTime();
+
+		$qb = $this->db->getQueryBuilder();
+		$qb->update(self::TABLE_NAME)
+			->set('last_sync', $qb->createNamedParameter($now, IQueryBuilder::PARAM_INT))
+			->where($qb->expr()->eq(
+				'id',
+				$qb->createNamedParameter($id, IQueryBuilder::PARAM_INT),
+				IQueryBuilder::PARAM_INT,
+			));
+		$qb->executeStatement();
+	}
+
+	public function updateSyncTokenAndTime(int $id, int $syncToken): void {
+		$now = $this->time->getTime();
+
+		$qb = $this->db->getQueryBuilder();
+		$qb->update(self::TABLE_NAME)
+			->set('sync_token', $qb->createNamedParameter($syncToken, IQueryBuilder::PARAM_INT))
+			->set('last_sync', $qb->createNamedParameter($now, IQueryBuilder::PARAM_INT))
+			->where($qb->expr()->eq(
+				'id',
+				$qb->createNamedParameter($id, IQueryBuilder::PARAM_INT),
+				IQueryBuilder::PARAM_INT,
+			));
+		$qb->executeStatement();
+	}
+
+	/**
+	 * @return \Generator<mixed, FederatedCalendarEntity>
+	 */
+	public function findAll(): \Generator {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('*')
+			->from(self::TABLE_NAME);
+
+		$result = $qb->executeQuery();
+		while ($row = $result->fetch()) {
+			yield $this->mapRowToEntity($row);
+		}
+		$result->closeCursor();
+	}
+
+	public function countAll(): int {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select($qb->func()->count('*'))
+			->from(self::TABLE_NAME);
+		$result = $qb->executeQuery();
+		$count = (int)$result->fetchOne();
+		$result->closeCursor();
+		return $count;
+	}
+
+	public function deleteByUri(string $principalUri, string $uri): void {
+		$qb = $this->db->getQueryBuilder();
+		$qb->delete(self::TABLE_NAME)
+			->where($qb->expr()->eq(
+				'principaluri',
+				$qb->createNamedParameter($principalUri, IQueryBuilder::PARAM_STR),
+				IQueryBuilder::PARAM_STR,
+			))
+			->andWhere($qb->expr()->eq(
+				'uri',
+				$qb->createNamedParameter($uri, IQueryBuilder::PARAM_STR),
+				IQueryBuilder::PARAM_STR,
+			));
+
+		$qb->executeStatement();
+	}
+
+	/**
+	 * @return FederatedCalendarEntity[]
+	 */
+	public function findByRemoteUrl(string $remoteUrl, string $principalUri, string $token): array {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('*')
+			->from(self::TABLE_NAME)
+			->where($qb->expr()->eq(
+				'remote_url',
+				$qb->createNamedParameter($remoteUrl, IQueryBuilder::PARAM_STR),
+				IQueryBuilder::PARAM_STR,
+			))
+			->andWhere($qb->expr()->eq(
+				'principaluri',
+				$qb->createNamedParameter($principalUri, IQueryBuilder::PARAM_STR),
+				IQueryBuilder::PARAM_STR,
+			))
+			->andWhere($qb->expr()->eq(
+				'token',
+				$qb->createNamedParameter($token, IQueryBuilder::PARAM_STR),
+				IQueryBuilder::PARAM_STR,
+			));
+
+		return $this->findEntities($qb);
+	}
+}

apps/dav/lib/CalDAV/Federation/FederatedCalendarSyncService.php

@@ -0,0 +1,76 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\CalDAV\Federation;
+
+use OCA\DAV\CalDAV\SyncService as CalDavSyncService;
+use OCP\Federation\ICloudIdManager;
+use Psr\Http\Client\ClientExceptionInterface;
+use Psr\Log\LoggerInterface;
+
+class FederatedCalendarSyncService {
+	private const SYNC_TOKEN_PREFIX = 'http://sabre.io/ns/sync/';
+
+	public function __construct(
+		private readonly FederatedCalendarMapper $federatedCalendarMapper,
+		private readonly LoggerInterface $logger,
+		private readonly CalDavSyncService $syncService,
+		private readonly ICloudIdManager $cloudIdManager,
+	) {
+	}
+
+	/**
+	 * @return int Downloaded event count (created or updated).
+	 *
+	 * @throws ClientExceptionInterface If syncing the calendar fails.
+	 */
+	public function syncOne(FederatedCalendarEntity $calendar): int {
+		[,, $sharedWith] = explode('/', $calendar->getPrincipaluri());
+		$calDavUser = $this->cloudIdManager->getCloudId($sharedWith, null)->getId();
+		$remoteUrl = $calendar->getRemoteUrl();
+		$syncToken = $calendar->getSyncTokenForSabre();
+
+		// Need to encode the cloud id as it might contain a colon which is not allowed in basic
+		// auth according to RFC 7617
+		$calDavUser = base64_encode($calDavUser);
+
+		$syncResponse = $this->syncService->syncRemoteCalendar(
+			$remoteUrl,
+			$calDavUser,
+			$calendar->getToken(),
+			$syncToken,
+			$calendar,
+		);
+
+		$newSyncToken = $syncResponse->getSyncToken();
+
+		// Check sync token format and extract the actual sync token integer
+		$matches = [];
+		if (!preg_match('/^http:\/\/sabre\.io\/ns\/sync\/([0-9]+)$/', $newSyncToken, $matches)) {
+			$this->logger->error("Failed to sync federated calendar at $remoteUrl: New sync token has unexpected format: $newSyncToken", [
+				'calendar' => $calendar->toCalendarInfo(),
+				'newSyncToken' => $newSyncToken,
+			]);
+			return 0;
+		}
+
+		$newSyncToken = (int)$matches[1];
+		if ($newSyncToken !== $calendar->getSyncToken()) {
+			$this->federatedCalendarMapper->updateSyncTokenAndTime(
+				$calendar->getId(),
+				$newSyncToken,
+			);
+		} else {
+			$this->logger->debug("Sync Token for $remoteUrl unchanged from previous sync");
+			$this->federatedCalendarMapper->updateSyncTime($calendar->getId());
+		}
+
+		return $syncResponse->getDownloadedEvents();
+	}
+}

apps/dav/lib/CalDAV/Federation/FederationSharingService.php

@@ -0,0 +1,180 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\CalDAV\Federation;
+
+use OCA\DAV\CalDAV\Federation\Protocol\CalendarFederationProtocolV1;
+use OCA\DAV\DAV\RemoteUserPrincipalBackend;
+use OCA\DAV\DAV\Sharing\IShareable;
+use OCA\DAV\DAV\Sharing\SharingMapper;
+use OCP\AppFramework\Http;
+use OCP\Federation\ICloudFederationFactory;
+use OCP\Federation\ICloudFederationProviderManager;
+use OCP\IURLGenerator;
+use OCP\IUserManager;
+use OCP\OCM\Exceptions\OCMProviderException;
+use OCP\Security\ISecureRandom;
+use Psr\Log\LoggerInterface;
+use Sabre\CalDAV\Calendar;
+
+// TODO: Convert this to an abstract service like the addressbook/calendar sharing services once we
+//       support addressbook federation as well.
+class FederationSharingService {
+	public function __construct(
+		private readonly ICloudFederationProviderManager $federationManager,
+		private readonly ICloudFederationFactory $federationFactory,
+		private readonly IUserManager $userManager,
+		private readonly IURLGenerator $url,
+		private readonly LoggerInterface $logger,
+		private readonly ISecureRandom $random,
+		private readonly SharingMapper $sharingMapper,
+	) {
+	}
+
+	/**
+	 * Decode a (base64) encoded remote user principal and return the remote user's cloud id. Will
+	 * return null if the given principal is not belonging to a remote user (or has an invalid
+	 * format).
+	 *
+	 * The remote user/cloud id needs to be encoded as it might contain slashes.
+	 */
+	private function decodeRemoteUserPrincipal(string $principal): ?string {
+		// Expected format: principals/remote-users/abcdef123
+		[$prefix, $collection, $encodedId] = explode('/', $principal);
+		if ($prefix !== 'principals' || $collection !== 'remote-users') {
+			return null;
+		}
+
+		$decodedId = base64_decode($encodedId);
+		if (!is_string($decodedId)) {
+			return null;
+		}
+
+		return $decodedId;
+	}
+
+	/**
+	 * Send a calendar share to a remote instance and create a federated share locally if it is
+	 * accepted.
+	 *
+	 * @param IShareable $shareable The calendar to be shared.
+	 * @param string $principal The principal to share with (should be a remote user principal).
+	 * @param int $access The access level. The remote serve might reject it.
+	 */
+	public function shareWith(IShareable $shareable, string $principal, int $access): void {
+		$baseError = 'Failed to create federated calendar share: ';
+
+		// 1. Validate share data
+		$shareWith = $this->decodeRemoteUserPrincipal($principal);
+		if ($shareWith === null) {
+			$this->logger->error($baseError . 'Principal of sharee is not belonging to a remote user', [
+				'shareable' => $shareable->getName(),
+				'encodedShareWith' => $principal,
+			]);
+			return;
+		}
+
+		[,, $ownerUid] = explode('/', $shareable->getOwner());
+		$owner = $this->userManager->get($ownerUid);
+		if ($owner === null) {
+			$this->logger->error($baseError . 'Shareable is not owned by a user on this server', [
+				'shareable' => $shareable->getName(),
+				'shareWith' => $shareWith,
+			]);
+			return;
+		}
+
+		// Need a calendar instance to extract properties for the protocol
+		$calendar = $shareable;
+		if (!($calendar instanceof Calendar)) {
+			$this->logger->error($baseError . 'Shareable is not a calendar', [
+				'shareable' => $shareable->getName(),
+				'owner' => $owner,
+				'shareWith' => $shareWith,
+			]);
+			return;
+		}
+
+		$getProp = static fn (string $prop) => $calendar->getProperties([$prop])[$prop] ?? null;
+
+		$displayName = $getProp('{DAV:}displayname') ?? '';
+
+		$token = $this->random->generate(32);
+		$share = $this->federationFactory->getCloudFederationShare(
+			$shareWith,
+			$shareable->getName(),
+			$displayName,
+			CalendarFederationProvider::PROVIDER_ID,
+			// Resharing is not possible so the owner is always the sharer
+			$owner->getCloudId(),
+			$owner->getDisplayName(),
+			$owner->getCloudId(),
+			$owner->getDisplayName(),
+			$token,
+			CalendarFederationProvider::USER_SHARE_TYPE,
+			CalendarFederationProvider::CALENDAR_RESOURCE,
+		);
+
+		// 2. Send share to federated instance
+		$shareWithEncoded = base64_encode($shareWith);
+		$relativeCalendarUrl = "remote-calendars/$shareWithEncoded/" . $calendar->getName() . '_shared_by_' . $ownerUid;
+		$calendarUrl = $this->url->linkTo('', 'remote.php') . "/dav/$relativeCalendarUrl";
+		$calendarUrl = $this->url->getAbsoluteURL($calendarUrl);
+		$protocol = new CalendarFederationProtocolV1();
+		$protocol->setUrl($calendarUrl);
+		$protocol->setDisplayName($displayName);
+		$protocol->setColor($getProp('{http://apple.com/ns/ical/}calendar-color'));
+		$protocol->setAccess($access);
+		$protocol->setComponents(implode(',', $getProp(
+			'{urn:ietf:params:xml:ns:caldav}supported-calendar-component-set')?->getValue() ?? [],
+		));
+		$share->setProtocol([
+			// Preserve original protocol contents
+			...$share->getProtocol(),
+			...$protocol->toProtocol(),
+		]);
+
+		try {
+			$response = $this->federationManager->sendCloudShare($share);
+		} catch (OCMProviderException $e) {
+			$this->logger->error($baseError . $e->getMessage(), [
+				'exception' => $e,
+				'owner' => $owner->getUID(),
+				'calendar' => $shareable->getName(),
+				'shareWith' => $shareWith,
+			]);
+			return;
+		}
+
+		if ($response->getStatusCode() !== Http::STATUS_CREATED) {
+			$this->logger->error($baseError . 'Server replied with code ' . $response->getStatusCode(), [
+				'responseBody' => $response->getBody(),
+				'owner' => $owner->getUID(),
+				'calendar' => $shareable->getName(),
+				'shareWith' => $shareWith,
+			]);
+			return;
+		}
+
+		// 3. Create a local DAV share to track the token for authentication
+		$shareWithPrincipalUri = RemoteUserPrincipalBackend::PRINCIPAL_PREFIX . '/' . $shareWithEncoded;
+		$this->sharingMapper->deleteShare(
+			$shareable->getResourceId(),
+			'calendar',
+			$shareWithPrincipalUri,
+		);
+		$this->sharingMapper->shareWithToken(
+			$shareable->getResourceId(),
+			'calendar',
+			$access,
+			$shareWithPrincipalUri,
+			$token,
+		);
+	}
+}

apps/dav/lib/CalDAV/Federation/Protocol/CalendarFederationProtocolV1.php

@@ -0,0 +1,125 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\CalDAV\Federation\Protocol;
+
+class CalendarFederationProtocolV1 implements ICalendarFederationProtocol {
+	public const VERSION = 'v1';
+
+	public const PROP_URL = 'url';
+	public const PROP_DISPLAY_NAME = 'displayName';
+	public const PROP_COLOR = 'color';
+	public const PROP_ACCESS = 'access';
+	public const PROP_COMPONENTS = 'components';
+
+	private string $url = '';
+	private string $displayName = '';
+	private ?string $color = null;
+	private int $access = 0;
+	private string $components = '';
+
+	/**
+	 * @throws CalendarProtocolParseException If parsing the raw protocol array fails.
+	 */
+	public static function parse(array $rawProtocol): self {
+		if ($rawProtocol[self::PROP_VERSION] !== self::VERSION) {
+			throw new CalendarProtocolParseException('Unknown protocol version');
+		}
+
+		$url = $rawProtocol[self::PROP_URL] ?? null;
+		if (!is_string($url)) {
+			throw new CalendarProtocolParseException('URL is missing or not a string');
+		}
+
+		$displayName = $rawProtocol[self::PROP_DISPLAY_NAME] ?? null;
+		if (!is_string($displayName)) {
+			throw new CalendarProtocolParseException('Display name is missing or not a string');
+		}
+
+		$color = $rawProtocol[self::PROP_COLOR] ?? null;
+		if (!is_string($color) && $color !== null) {
+			throw new CalendarProtocolParseException('Color is set but not a string');
+		}
+
+		$access = $rawProtocol[self::PROP_ACCESS] ?? null;
+		if (!is_int($access)) {
+			throw new CalendarProtocolParseException('Access is missing or not an integer');
+		}
+
+		$components = $rawProtocol[self::PROP_COMPONENTS] ?? null;
+		if (!is_string($components)) {
+			throw new CalendarProtocolParseException('Supported calendar components are missing or not a string');
+		}
+
+		$protocol = new self();
+		$protocol->setUrl($url);
+		$protocol->setDisplayName($displayName);
+		$protocol->setColor($color);
+		$protocol->setAccess($access);
+		$protocol->setComponents($components);
+		return $protocol;
+	}
+
+	#[\Override]
+	public function toProtocol(): array {
+		return [
+			self::PROP_VERSION => $this->getVersion(),
+			self::PROP_URL => $this->getUrl(),
+			self::PROP_DISPLAY_NAME => $this->getDisplayName(),
+			self::PROP_COLOR => $this->getColor(),
+			self::PROP_ACCESS => $this->getAccess(),
+			self::PROP_COMPONENTS => $this->getComponents(),
+		];
+	}
+
+	#[\Override]
+	public function getVersion(): string {
+		return self::VERSION;
+	}
+
+	public function getUrl(): string {
+		return $this->url;
+	}
+
+	public function setUrl(string $url): void {
+		$this->url = $url;
+	}
+
+	public function getDisplayName(): string {
+		return $this->displayName;
+	}
+
+	public function setDisplayName(string $displayName): void {
+		$this->displayName = $displayName;
+	}
+
+	public function getColor(): ?string {
+		return $this->color;
+	}
+
+	public function setColor(?string $color): void {
+		$this->color = $color;
+	}
+
+	public function getAccess(): int {
+		return $this->access;
+	}
+
+	public function setAccess(int $access): void {
+		$this->access = $access;
+	}
+
+	public function getComponents(): string {
+		return $this->components;
+	}
+
+	public function setComponents(string $components): void {
+		$this->components = $components;
+	}
+}

apps/dav/lib/CalDAV/Federation/Protocol/CalendarProtocolParseException.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\CalDAV\Federation\Protocol;
+
+class CalendarProtocolParseException extends \Exception {
+}

apps/dav/lib/CalDAV/Federation/Protocol/ICalendarFederationProtocol.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\CalDAV\Federation\Protocol;
+
+interface ICalendarFederationProtocol {
+	public const PROP_VERSION = 'version';
+
+	/**
+	 * Get the version of this protocol implementation.
+	 */
+	public function getVersion(): string;
+
+	/**
+	 * Convert the protocol to an associative array to be sent to a remote instance.
+	 * The resulting array still needs to be merged with the base protocol from the share!
+	 */
+	public function toProtocol(): array;
+}

apps/dav/lib/CalDAV/Federation/RemoteUserCalendarHome.php

@@ -0,0 +1,67 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\CalDAV\Federation;
+
+use OCA\DAV\CalDAV\Calendar;
+use OCP\IConfig;
+use OCP\IL10N;
+use Psr\Log\LoggerInterface;
+use Sabre\CalDAV\Backend;
+use Sabre\CalDAV\CalendarHome;
+use Sabre\DAV\Exception\NotFound;
+
+class RemoteUserCalendarHome extends CalendarHome {
+	public function __construct(
+		Backend\BackendInterface $caldavBackend,
+		$principalInfo,
+		private readonly IL10N $l10n,
+		private readonly IConfig $config,
+		private readonly LoggerInterface $logger,
+	) {
+		parent::__construct($caldavBackend, $principalInfo);
+	}
+
+	public function getChild($name) {
+		// Remote users can only have incoming shared calendars so we can skip the rest of a regular
+		// calendar home
+		foreach ($this->caldavBackend->getCalendarsForUser($this->principalInfo['uri']) as $calendar) {
+			if ($calendar['uri'] === $name) {
+				return new Calendar(
+					$this->caldavBackend,
+					$calendar,
+					$this->l10n,
+					$this->config,
+					$this->logger,
+				);
+			}
+		}
+
+		throw new NotFound("Node with name $name could not be found");
+	}
+
+	public function getChildren(): array {
+		$objects = [];
+
+		// Remote users can only have incoming shared calendars so we can skip the rest of a regular
+		// calendar home
+		$calendars = $this->caldavBackend->getCalendarsForUser($this->principalInfo['uri']);
+		foreach ($calendars as $calendar) {
+			$objects[] = new Calendar(
+				$this->caldavBackend,
+				$calendar,
+				$this->l10n,
+				$this->config,
+				$this->logger,
+			);
+		}
+
+		return $objects;
+	}
+}

apps/dav/lib/CalDAV/Import/ImportService.php

@@ -0,0 +1,334 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCA\DAV\CalDAV\Import;
+
+use Exception;
+use Generator;
+use InvalidArgumentException;
+use OCA\DAV\CalDAV\CalDavBackend;
+use OCA\DAV\CalDAV\CalendarImpl;
+use OCP\Calendar\CalendarImportOptions;
+use Sabre\VObject\Component\VCalendar;
+use Sabre\VObject\Node;
+use Sabre\VObject\Reader;
+use Sabre\VObject\UUIDUtil;
+
+/**
+ * Calendar Import Service
+ */
+class ImportService {
+
+	/** @var resource */
+	private $source;
+
+	public function __construct(
+		private CalDavBackend $backend,
+	) {
+	}
+
+	/**
+	 * Executes import with appropriate object generator based on format
+	 *
+	 * @param resource $source
+	 *
+	 * @return array<string,array<string,string|array<string>>>
+	 *
+	 * @throws \InvalidArgumentException
+	 */
+	public function import($source, CalendarImpl $calendar, CalendarImportOptions $options): array {
+		if (!is_resource($source)) {
+			throw new InvalidArgumentException('Invalid import source must be a file resource');
+		}
+
+		$this->source = $source;
+
+		switch ($options->getFormat()) {
+			case 'ical':
+				return $this->importProcess($calendar, $options, $this->importText(...));
+				break;
+			case 'jcal':
+				return $this->importProcess($calendar, $options, $this->importJson(...));
+				break;
+			case 'xcal':
+				return $this->importProcess($calendar, $options, $this->importXml(...));
+				break;
+			default:
+				throw new InvalidArgumentException('Invalid import format');
+		}
+	}
+
+	/**
+	 * Generates object stream from a text formatted source (ical)
+	 *
+	 * @return Generator<\Sabre\VObject\Component\VCalendar>
+	 */
+	private function importText(): Generator {
+		$importer = new TextImporter($this->source);
+		$structure = $importer->structure();
+		$sObjectPrefix = $importer::OBJECT_PREFIX;
+		$sObjectSuffix = $importer::OBJECT_SUFFIX;
+		// calendar properties
+		foreach ($structure['VCALENDAR'] as $entry) {
+			if (!str_ends_with($entry, "\n") || !str_ends_with($entry, "\r\n")) {
+				$sObjectPrefix .= PHP_EOL;
+			}
+		}
+		// calendar time zones
+		$timezones = [];
+		foreach ($structure['VTIMEZONE'] as $tid => $collection) {
+			$instance = $collection[0];
+			$sObjectContents = $importer->extract((int)$instance[2], (int)$instance[3]);
+			$vObject = Reader::read($sObjectPrefix . $sObjectContents . $sObjectSuffix);
+			$timezones[$tid] = clone $vObject->VTIMEZONE;
+		}
+		// calendar components
+		// for each component type, construct a full calendar object with all components
+		// that match the same UID and appropriate time zones that are used in the components
+		foreach (['VEVENT', 'VTODO', 'VJOURNAL'] as $type) {
+			foreach ($structure[$type] as $cid => $instances) {
+				/** @var array<int,VCalendar> $instances */
+				// extract all instances of component and unserialize to object
+				$sObjectContents = '';
+				foreach ($instances as $instance) {
+					$sObjectContents .= $importer->extract($instance[2], $instance[3]);
+				}
+				/** @var VCalendar $vObject */
+				$vObject = Reader::read($sObjectPrefix . $sObjectContents . $sObjectSuffix);
+				// add time zones to object
+				foreach ($this->findTimeZones($vObject) as $zone) {
+					if (isset($timezones[$zone])) {
+						$vObject->add(clone $timezones[$zone]);
+					}
+				}
+				yield $vObject;
+			}
+		}
+	}
+
+	/**
+	 * Generates object stream from a xml formatted source (xcal)
+	 *
+	 * @return Generator<\Sabre\VObject\Component\VCalendar>
+	 */
+	private function importXml(): Generator {
+		$importer = new XmlImporter($this->source);
+		$structure = $importer->structure();
+		$sObjectPrefix = $importer::OBJECT_PREFIX;
+		$sObjectSuffix = $importer::OBJECT_SUFFIX;
+		// calendar time zones
+		$timezones = [];
+		foreach ($structure['VTIMEZONE'] as $tid => $collection) {
+			$instance = $collection[0];
+			$sObjectContents = $importer->extract((int)$instance[2], (int)$instance[3]);
+			$vObject = Reader::readXml($sObjectPrefix . $sObjectContents . $sObjectSuffix);
+			$timezones[$tid] = clone $vObject->VTIMEZONE;
+		}
+		// calendar components
+		// for each component type, construct a full calendar object with all components
+		// that match the same UID and appropriate time zones that are used in the components
+		foreach (['VEVENT', 'VTODO', 'VJOURNAL'] as $type) {
+			foreach ($structure[$type] as $cid => $instances) {
+				/** @var array<int,VCalendar> $instances */
+				// extract all instances of component and unserialize to object
+				$sObjectContents = '';
+				foreach ($instances as $instance) {
+					$sObjectContents .= $importer->extract($instance[2], $instance[3]);
+				}
+				/** @var VCalendar $vObject */
+				$vObject = Reader::readXml($sObjectPrefix . $sObjectContents . $sObjectSuffix);
+				// add time zones to object
+				foreach ($this->findTimeZones($vObject) as $zone) {
+					if (isset($timezones[$zone])) {
+						$vObject->add(clone $timezones[$zone]);
+					}
+				}
+				yield $vObject;
+			}
+		}
+	}
+
+	/**
+	 * Generates object stream from a json formatted source (jcal)
+	 *
+	 * @return Generator<\Sabre\VObject\Component\VCalendar>
+	 */
+	private function importJson(): Generator {
+		/** @var VCALENDAR $importer */
+		$importer = Reader::readJson($this->source);
+		// calendar time zones
+		$timezones = [];
+		foreach ($importer->VTIMEZONE as $timezone) {
+			$tzid = $timezone->TZID?->getValue();
+			if ($tzid !== null) {
+				$timezones[$tzid] = clone $timezone;
+			}
+		}
+		// calendar components
+		foreach ($importer->getBaseComponents() as $base) {
+			$vObject = new VCalendar;
+			$vObject->VERSION = clone $importer->VERSION;
+			$vObject->PRODID = clone $importer->PRODID;
+			// extract all instances of component
+			foreach ($importer->getByUID($base->UID->getValue()) as $instance) {
+				$vObject->add(clone $instance);
+			}
+			// add time zones to object
+			foreach ($this->findTimeZones($vObject) as $zone) {
+				if (isset($timezones[$zone])) {
+					$vObject->add(clone $timezones[$zone]);
+				}
+			}
+			yield $vObject;
+		}
+	}
+
+	/**
+	 * Searches through all component properties looking for defined timezones
+	 *
+	 * @return array<string>
+	 */
+	private function findTimeZones(VCalendar $vObject): array {
+		$timezones = [];
+		foreach ($vObject->getComponents() as $vComponent) {
+			if ($vComponent->name !== 'VTIMEZONE') {
+				foreach (['DTSTART', 'DTEND', 'DUE', 'RDATE', 'EXDATE'] as $property) {
+					if (isset($vComponent->$property?->parameters['TZID'])) {
+						$tid = $vComponent->$property->parameters['TZID']->getValue();
+						$timezones[$tid] = true;
+					}
+				}
+			}
+		}
+		return array_keys($timezones);
+	}
+
+	/**
+	 * Import objects
+	 *
+	 * @since 32.0.0
+	 *
+	 * @param CalendarImportOptions $options
+	 * @param callable $generator<CalendarImportOptions>: Generator<\Sabre\VObject\Component\VCalendar>
+	 *
+	 * @return array<string,array<string,string|array<string>>>
+	 */
+	public function importProcess(CalendarImpl $calendar, CalendarImportOptions $options, callable $generator): array {
+		$calendarId = $calendar->getKey();
+		$calendarUri = $calendar->getUri();
+		$principalUri = $calendar->getPrincipalUri();
+		$outcome = [];
+		foreach ($generator() as $vObject) {
+			$components = $vObject->getBaseComponents();
+			// determine if the object has no base component types
+			if (count($components) === 0) {
+				$errorMessage = 'One or more objects discovered with no base component types';
+				if ($options->getErrors() === $options::ERROR_FAIL) {
+					throw new InvalidArgumentException('Error importing calendar data: ' . $errorMessage);
+				}
+				$outcome['nbct'] = ['outcome' => 'error', 'errors' => [$errorMessage]];
+				continue;
+			}
+			// determine if the object has more than one base component type
+			// object can have multiple base components with the same uid
+			// but we need to make sure they are of the same type
+			if (count($components) > 1) {
+				$type = $components[0]->name;
+				foreach ($components as $entry) {
+					if ($type !== $entry->name) {
+						$errorMessage = 'One or more objects discovered with multiple base component types';
+						if ($options->getErrors() === $options::ERROR_FAIL) {
+							throw new InvalidArgumentException('Error importing calendar data: ' . $errorMessage);
+						}
+						$outcome['mbct'] = ['outcome' => 'error', 'errors' => [$errorMessage]];
+						continue 2;
+					}
+				}
+			}
+			// determine if the object has a uid
+			if (!isset($components[0]->UID)) {
+				$errorMessage = 'One or more objects discovered without a UID';
+				if ($options->getErrors() === $options::ERROR_FAIL) {
+					throw new InvalidArgumentException('Error importing calendar data: ' . $errorMessage);
+				}
+				$outcome['noid'] = ['outcome' => 'error', 'errors' => [$errorMessage]];
+				continue;
+			}
+			$uid = $components[0]->UID->getValue();
+			// validate object
+			if ($options->getValidate() !== $options::VALIDATE_NONE) {
+				$issues = $this->componentValidate($vObject, true, 3);
+				if ($options->getValidate() === $options::VALIDATE_SKIP && $issues !== []) {
+					$outcome[$uid] = ['outcome' => 'error', 'errors' => $issues];
+					continue;
+				} elseif ($options->getValidate() === $options::VALIDATE_FAIL && $issues !== []) {
+					throw new InvalidArgumentException('Error importing calendar data: UID <' . $uid . '> - ' . $issues[0]);
+				}
+			}
+			// create or update object in the data store
+			$objectId = $this->backend->getCalendarObjectByUID($principalUri, $uid, $calendarUri);
+			$objectData = $vObject->serialize();
+			try {
+				if ($objectId === null) {
+					$objectId = UUIDUtil::getUUID();
+					$this->backend->createCalendarObject(
+						$calendarId,
+						$objectId,
+						$objectData
+					);
+					$outcome[$uid] = ['outcome' => 'created'];
+				} else {
+					[$cid, $oid] = explode('/', $objectId);
+					if ($options->getSupersede()) {
+						$this->backend->updateCalendarObject(
+							$calendarId,
+							$oid,
+							$objectData
+						);
+						$outcome[$uid] = ['outcome' => 'updated'];
+					} else {
+						$outcome[$uid] = ['outcome' => 'exists'];
+					}
+				}
+			} catch (Exception $e) {
+				$errorMessage = $e->getMessage();
+				if ($options->getErrors() === $options::ERROR_FAIL) {
+					throw new Exception('Error importing calendar data: UID <' . $uid . '> - ' . $errorMessage, 0, $e);
+				}
+				$outcome[$uid] = ['outcome' => 'error', 'errors' => [$errorMessage]];
+			}
+		}
+
+		return $outcome;
+	}
+
+	/**
+	 * Validate a component
+	 *
+	 * @param VCalendar $vObject
+	 * @param bool $repair attempt to repair the component
+	 * @param int $level minimum level of issues to return
+	 * @return list<mixed>
+	 */
+	private function componentValidate(VCalendar $vObject, bool $repair, int $level): array {
+		// validate component(S)
+		$issues = $vObject->validate(Node::PROFILE_CALDAV);
+		// attempt to repair
+		if ($repair && count($issues) > 0) {
+			$issues = $vObject->validate(Node::REPAIR);
+		}
+		// filter out messages based on level
+		$result = [];
+		foreach ($issues as $key => $issue) {
+			if (isset($issue['level']) && $issue['level'] >= $level) {
+				$result[] = $issue['message'];
+			}
+		}
+
+		return $result;
+	}
+}

apps/dav/lib/CalDAV/Import/TextImporter.php

@@ -0,0 +1,156 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCA\DAV\CalDAV\Import;
+
+use Exception;
+
+class TextImporter {
+
+	public const OBJECT_PREFIX = 'BEGIN:VCALENDAR' . PHP_EOL;
+	public const OBJECT_SUFFIX = PHP_EOL . 'END:VCALENDAR';
+	private const COMPONENT_TYPES = ['VEVENT', 'VTODO', 'VJOURNAL', 'VTIMEZONE'];
+
+	private bool $analyzed = false;
+	private array $structure = ['VCALENDAR' => [], 'VEVENT' => [], 'VTODO' => [], 'VJOURNAL' => [], 'VTIMEZONE' => []];
+
+	/**
+	 * @param resource $source
+	 */
+	public function __construct(
+		private $source,
+	) {
+		// Ensure that source is a stream resource
+		if (!is_resource($source) || get_resource_type($source) !== 'stream') {
+			throw new Exception('Source must be a stream resource');
+		}
+	}
+
+	/**
+	 * Analyzes the source data and creates a structure of components
+	 */
+	private function analyze() {
+		$componentStart = null;
+		$componentEnd = null;
+		$componentId = null;
+		$componentType = null;
+		$tagName = null;
+		$tagValue = null;
+
+		// iterate through the source data line by line
+		fseek($this->source, 0);
+		while (!feof($this->source)) {
+			$data = fgets($this->source);
+			// skip empty lines
+			if ($data === false || empty(trim($data))) {
+				continue;
+			}
+			// lines with whitespace at the beginning are continuations of the previous line
+			if (ctype_space($data[0]) === false) {
+				// detect the line TAG
+				// detect the first occurrence of ':' or ';'
+				$colonPos = strpos($data, ':');
+				$semicolonPos = strpos($data, ';');
+				if ($colonPos !== false && $semicolonPos !== false) {
+					$splitPosition = min($colonPos, $semicolonPos);
+				} elseif ($colonPos !== false) {
+					$splitPosition = $colonPos;
+				} elseif ($semicolonPos !== false) {
+					$splitPosition = $semicolonPos;
+				} else {
+					continue;
+				}
+				$tagName = strtoupper(trim(substr($data, 0, $splitPosition)));
+				$tagValue = trim(substr($data, $splitPosition + 1));
+				$tagContinuation = false;
+			} else {
+				$tagContinuation = true;
+				$tagValue .= trim($data);
+			}
+
+			if ($tagContinuation === false) {
+				// check line for component start, remember the position and determine the type
+				if ($tagName === 'BEGIN' && in_array($tagValue, self::COMPONENT_TYPES, true)) {
+					$componentStart = ftell($this->source) - strlen($data);
+					$componentType = $tagValue;
+				}
+				// check line for component end, remember the position
+				if ($tagName === 'END' && $componentType === $tagValue) {
+					$componentEnd = ftell($this->source);
+				}
+				// check line for component id
+				if ($componentStart !== null && ($tagName === 'UID' || $tagName === 'TZID')) {
+					$componentId = $tagValue;
+				}
+			} else {
+				// check line for component id
+				if ($componentStart !== null && ($tagName === 'UID' || $tagName === 'TZID')) {
+					$componentId = $tagValue;
+				}
+			}
+			// any line(s) not inside a component are VCALENDAR properties
+			if ($componentStart === null) {
+				if ($tagName !== 'BEGIN' && $tagName !== 'END' && $tagValue === 'VCALENDAR') {
+					$components['VCALENDAR'][] = $data;
+				}
+			}
+			// if component start and end are found, add the component to the structure
+			if ($componentStart !== null && $componentEnd !== null) {
+				if ($componentId !== null) {
+					$this->structure[$componentType][$componentId][] = [
+						$componentType,
+						$componentId,
+						$componentStart,
+						$componentEnd
+					];
+				} else {
+					$this->structure[$componentType][] = [
+						$componentType,
+						$componentId,
+						$componentStart,
+						$componentEnd
+					];
+				}
+				$componentId = null;
+				$componentType = null;
+				$componentStart = null;
+				$componentEnd = null;
+			}
+		}
+	}
+
+	/**
+	 * Returns the analyzed structure of the source data
+	 * the analyzed structure is a collection of components organized by type,
+	 * each entry is a collection of instances
+	 * [
+	 *  'VEVENT' => [
+	 *    '7456f141-b478-4cb9-8efc-1427ba0d6839' => [
+	 *      ['VEVENT', '7456f141-b478-4cb9-8efc-1427ba0d6839', 0, 100 ],
+	 *      ['VEVENT', '7456f141-b478-4cb9-8efc-1427ba0d6839', 100, 200 ]
+	 *    ]
+	 *  ]
+	 * ]
+	 */
+	public function structure(): array {
+		if (!$this->analyzed) {
+			$this->analyze();
+		}
+		return $this->structure;
+	}
+
+	/**
+	 * Extracts a string chuck from the source data
+	 *
+	 * @param int $start starting byte position
+	 * @param int $end ending byte position
+	 */
+	public function extract(int $start, int $end): string {
+		fseek($this->source, $start);
+		return fread($this->source, $end - $start);
+	}
+}

apps/dav/lib/CalDAV/Import/XmlImporter.php

@@ -0,0 +1,173 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCA\DAV\CalDAV\Import;
+
+use Exception;
+use XMLParser;
+
+class XmlImporter {
+
+	public const OBJECT_PREFIX = '<?xml version="1.0" encoding="UTF-8"?><icalendar xmlns="urn:ietf:params:xml:ns:icalendar-2.0"><vcalendar><components>';
+	public const OBJECT_SUFFIX = '</components></vcalendar></icalendar>';
+	private const COMPONENT_TYPES = ['VEVENT', 'VTODO', 'VJOURNAL', 'VTIMEZONE'];
+
+	private bool $analyzed = false;
+	private array $structure = ['VCALENDAR' => [], 'VEVENT' => [], 'VTODO' => [], 'VJOURNAL' => [], 'VTIMEZONE' => []];
+	private int $praseLevel = 0;
+	private array $prasePath = [];
+	private ?int $componentStart = null;
+	private ?int $componentEnd = null;
+	private int $componentLevel = 0;
+	private ?string $componentId = null;
+	private ?string $componentType = null;
+	private bool $componentIdProperty = false;
+
+	/**
+	 * @param resource $source
+	 */
+	public function __construct(
+		private $source,
+	) {
+		// Ensure that source is a stream resource
+		if (!is_resource($source) || get_resource_type($source) !== 'stream') {
+			throw new Exception('Source must be a stream resource');
+		}
+	}
+
+	/**
+	 * Analyzes the source data and creates a structure of components
+	 */
+	private function analyze() {
+		$this->praseLevel = 0;
+		$this->prasePath = [];
+		$this->componentStart = null;
+		$this->componentEnd = null;
+		$this->componentLevel = 0;
+		$this->componentId = null;
+		$this->componentType = null;
+		$this->componentIdProperty = false;
+		// Create the parser and assign tag handlers
+		$parser = xml_parser_create();
+		xml_set_object($parser, $this);
+		xml_set_element_handler($parser, $this->tagStart(...), $this->tagEnd(...));
+		xml_set_default_handler($parser, $this->tagContents(...));
+		// iterate through the source data chuck by chunk to trigger the handlers
+		@fseek($this->source, 0);
+		while ($chunk = fread($this->source, 4096)) {
+			if (!xml_parse($parser, $chunk, feof($this->source))) {
+				throw new Exception(
+					xml_error_string(xml_get_error_code($parser))
+					. ' At line: '
+					. xml_get_current_line_number($parser)
+				);
+			}
+		}
+		//Free up the parser
+		xml_parser_free($parser);
+	}
+
+	/**
+	 * Handles start of tag events from the parser for all tags
+	 */
+	private function tagStart(XMLParser $parser, string $tag, array $attributes): void {
+		// add the tag to the path tracker and increment depth the level
+		$this->praseLevel++;
+		$this->prasePath[$this->praseLevel] = $tag;
+		// determine if the tag is a component type and remember the byte position
+		if (in_array($tag, self::COMPONENT_TYPES, true)) {
+			$this->componentStart = xml_get_current_byte_index($parser) - (strlen($tag) + 1);
+			$this->componentType = $tag;
+			$this->componentLevel = $this->praseLevel;
+		}
+		// determine if the tag is a sub tag of the component and an id property
+		if ($this->componentStart !== null
+			&& ($this->componentLevel + 2) === $this->praseLevel
+			&& ($tag === 'UID' || $tag === 'TZID')
+		) {
+			$this->componentIdProperty = true;
+		}
+	}
+
+	/**
+	 * Handles end of tag events from the parser for all tags
+	 */
+	private function tagEnd(XMLParser $parser, string $tag): void {
+		// if the end tag matched the component type or the component id property
+		// then add the component to the structure
+		if ($tag === 'UID' || $tag === 'TZID') {
+			$this->componentIdProperty = false;
+		} elseif ($this->componentType === $tag) {
+			$this->componentEnd = xml_get_current_byte_index($parser);
+			if ($this->componentId !== null) {
+				$this->structure[$this->componentType][$this->componentId][] = [
+					$this->componentType,
+					$this->componentId,
+					$this->componentStart,
+					$this->componentEnd,
+					implode('/', $this->prasePath)
+				];
+			} else {
+				$this->structure[$this->componentType][] = [
+					$this->componentType,
+					$this->componentId,
+					$this->componentStart,
+					$this->componentEnd,
+					implode('/', $this->prasePath)
+				];
+			}
+			$this->componentStart = null;
+			$this->componentEnd = null;
+			$this->componentId = null;
+			$this->componentType = null;
+			$this->componentIdProperty = false;
+		}
+		// remove the tag from the path tacker and depth the level
+		unset($this->prasePath[$this->praseLevel]);
+		$this->praseLevel--;
+	}
+
+	/**
+	 * Handles tag contents events from the parser for all tags
+	 */
+	private function tagContents(XMLParser $parser, string $data): void {
+		if ($this->componentIdProperty) {
+			$this->componentId = $data;
+		}
+	}
+
+	/**
+	 * Returns the analyzed structure of the source data
+	 * the analyzed structure is a collection of components organized by type,
+	 * each entry is a collection of instances
+	 * [
+	 *  'VEVENT' => [
+	 *    '7456f141-b478-4cb9-8efc-1427ba0d6839' => [
+	 *      ['VEVENT', '7456f141-b478-4cb9-8efc-1427ba0d6839', 0, 100 ],
+	 *      ['VEVENT', '7456f141-b478-4cb9-8efc-1427ba0d6839', 100, 200 ]
+	 *    ]
+	 *  ]
+	 * ]
+	 */
+	public function structure(): array {
+		if (!$this->analyzed) {
+			$this->analyze();
+		}
+		return $this->structure;
+	}
+
+	/**
+	 * Extracts a string chuck from the source data
+	 *
+	 * @param int $start starting byte position
+	 * @param int $end ending byte position
+	 */
+	public function extract(int $start, int $end): string {
+		fseek($this->source, $start);
+		return fread($this->source, $end - $start);
+	}
+}

apps/dav/lib/CalDAV/Publishing/PublishPlugin.php

@@ -6,7 +6,9 @@
  */
 namespace OCA\DAV\CalDAV\Publishing;
 
+use OCA\DAV\CalDAV\CalDavBackend;
 use OCA\DAV\CalDAV\Calendar;
+use OCA\DAV\CalDAV\CalendarHome;
 use OCA\DAV\CalDAV\Publishing\Xml\Publisher;
 use OCP\AppFramework\Http;
 use OCP\IConfig;
@@ -91,6 +93,20 @@ class PublishPlugin extends ServerPlugin {
 	}
 
 	public function propFind(PropFind $propFind, INode $node) {
+		if ($node instanceof CalendarHome && $propFind->getDepth() === 1) {
+			$backend = $node->getCalDAVBackend();
+			if ($backend instanceof CalDavBackend) {
+				$calendars = array_filter(
+					$node->getChildren(),
+					static fn ($child) => $child instanceof Calendar,
+				);
+				$resourceIds = array_map(
+					static fn (Calendar $calendar) => $calendar->getResourceId(),
+					$calendars,
+				);
+				$backend->preloadPublishStatuses($resourceIds);
+			}
+		}
 		if ($node instanceof Calendar) {
 			$propFind->handle('{' . self::NS_CALENDARSERVER . '}publish-url', function () use ($node) {
 				if ($node->getPublishStatus()) {