Rename per-user backup/restore commands to backup:user:backup and backup:user:restore

backup:verify accepts a user export path (users/<uid>/<export>): every blob its manifest references
is checked the same way as for a snapshot, shallow or --deep.

The SMB backend is refused at backup:target:add when the native smbclient PECL extension is not
loaded, instead of registering and then failing the first backup with "Seek failed": with only the
smbclient binary files_external falls back to a shell stream that cannot seek.

The per-user integration job now runs on Nextcloud 32-35, not just 35: it calls user_migration's
internal UserMigrationService, whose API may change between versions.

.github/workflows/ci.yml

@@ -60,3 +60,35 @@ jobs:
       - uses: actions/checkout@v4
       - name: Round trip against S3 and SFTP
         run: tests/integration/targets-matrix.sh
+
+  integration-user:
+    # Per-user backup/restore via user_migration (occ backup:user:backup / backup:user:restore),
+    # an optional dependency installed from the app store. It calls user_migration's internal
+    # UserMigrationService, whose API can change between Nextcloud versions, so this runs on every
+    # supported version (not the database, which the main integration job already covers).
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        nextcloud: ['32', '33', '34', '35']
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up a fresh Nextcloud instance
+        run: |
+          docker run -d --name ngbu -e SQLITE_DATABASE=nextcloud -e NEXTCLOUD_ADMIN_USER=admin \
+            -e NEXTCLOUD_ADMIN_PASSWORD=admin-user-roundtrip -e NEXTCLOUD_TRUSTED_DOMAINS=localhost \
+            -v "$PWD:/var/www/html/custom_apps/ng_backup:ro" nextcloud:${{ matrix.nextcloud }}-apache
+          for i in $(seq 1 90); do docker exec -u www-data ngbu php occ status 2>/dev/null | grep -q "installed: true" && break; sleep 4; done
+          docker exec ngbu chown www-data:www-data /var/www/html/custom_apps
+      - name: Per-user backup/restore round trip on Nextcloud ${{ matrix.nextcloud }}
+        run: tests/integration/user-roundtrip.sh "docker exec -u www-data ngbu" /var/www/html/data
+
+  integration-full-restore:
+    # Disaster recovery (occ backup:restore:full) on a SECOND, fresh Nextcloud instance that
+    # never saw the first one, sharing only the backup location. Does not depend on the database
+    # beyond what the main integration job already covers, so this runs once, on one NC version.
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Full restore round trip
+        run: tests/integration/full-restore-roundtrip.sh 35-apache

CHANGELOG.md

@@ -42,3 +42,5 @@ and not implemented yet.
 - No FTP/SMB coverage in CI yet, and no verification/checksum-audit command yet (phase 2).
 - See the "Storage backend experiences" section of the README for provider-specific quirks found
   so far (e.g. Hetzner Storage Box sub-accounts).
+
+[0.1.0-alpha.1]: https://github.com/dillardblom/ng_backup/releases/tag/v0.1.0-alpha.1

PLAN.md

@@ -276,7 +276,7 @@ onderdelen wel en niet terugkomen, op basis van de geregistreerde migrators.
 | `backup:list [--target=]` | herstelpunten |
 | `backup:verify <snapshot> [--deep]` | checksums controleren, optioneel alles ontsleutelen |
 | `backup:restore:file <snapshot> <user> <pad> [--to=]` | bestand/map terugzetten |
-| `backup:restore:user <snapshot> <user> [--to-user=]` | gebruiker terugzetten via user_migration (fase 2) |
+| `backup:user:restore <snapshot> <user> [--to-user=]` | gebruiker terugzetten via user_migration (fase 2) |
 | `backup:restore:full <snapshot>` | volledige restore (fase 2, verse installatie) |
 | `backup:target:add/list/remove/test` | opslagdoelen beheren en testen |
 | `backup:key:export / import` | herstelkit |
@@ -338,6 +338,25 @@ een backup-app die niet betrouwbaar is, is erger dan geen backup-app.
 Volgorde: fase 1 grondig testen, reviewen en debuggen; dan nadenken over 0.1.0-alpha.1. Een
 minimale volledige restore (`occ backup:restore:full` op een verse installatie) komt vóór de beta.
 
+**Roadmap-indeling fase 2 (besluit 2026-10-05):** naar v1.2.0 toewerken met in fase 2:
+1. `backup:restore:full` (disaster recovery, verse installatie) — **klaar** (2026-10-05)
+2. FTP/SMB-ondersteuning — **klaar** (2026-10-06): beide liepen al via files_external's generieke
+   adapter zonder enige ng_backup-code; alleen testdekking toegevoegd
+   (`tests/integration/targets-matrix.sh`) + bevindingen in README ("Storage backend experiences").
+   SMB vereist de `smbclient` PECL-extensie (niet standaard in de Nextcloud-image, in CI nu
+   on-the-fly gebouwd). NFS is geen eigen backend: lokaal mounten + `local`-backend erop richten.
+3. Verificatie/checksum-audit-commando — **klaar** (2026-10-05)
+4. Retentie/prune voor user-exports — **klaar** (2026-10-06): `occ backup:retention --user-last=N`
+   (standaard 3, per installatie, net als de bestaande snapshot-policy), toegepast door
+   `occ backup:prune` (geen prullenbak voor user-exports, in tegenstelling tot snapshots — on-demand,
+   niet het primaire vangnet).
+5. Automatische user-export inpluggen in het reguliere schema (of expliciet besluit dat het on-demand blijft)
+9. SMB/NFS intern testen op de eigen OMV-instantie — nog open (intern, niet in CI)
+
+Doorgeschoven naar **v1.3.0** (fase 3, niet meer fase 2): in-place volledige restore
+(eigen restore-modus i.p.v. onderhoudsmodus) en zelfbediening voor gebruikers (eigen bestanden
+terugzetten vanuit de Files-app).
+
 **Let op (ontdekt 2026-10-05):** Nextcloud's eigen `info.xsd` staat voor `<version>` alleen
 `[0-9]+(\.[0-9]+){0,2}` toe — geen `-alpha`/`-beta`/`-rc`-achtervoegsel. De stabiliteitsaanduiding
 uit deze tabel gaat dus niet in `info.xml` (dat blijft gewoon oplopend, bijv. `0.1.0`), maar in de

README.md

@@ -2,8 +2,10 @@
 
 Encrypted, incremental backups of Nextcloud (database, configuration and data) with restore
 from the web interface. Works without shell access: no external programs, no extra PHP
-extensions beyond sodium. Runs on Nextcloud All-in-One, regular installations and hosted
+extensions beyond sodium for ng_backup itself. Runs on Nextcloud All-in-One, regular
-Nextcloud.
+installations and hosted Nextcloud. (Choosing SMB as a storage backend is the one exception:
+see "Storage backend experiences" below — that requirement comes from files_external, not from
+ng_backup, and applies to any Nextcloud app that writes to an SMB share.)
 
 **Status: in development (phase 1). Not ready for production use.** See `PLAN.md` for the design.
 
@@ -119,6 +121,29 @@ Contributions welcome via PR — add what you ran into with your own provider.
   verified whether this also applies to a Hetzner Storage Box **main** account (only tested with a
   sub-account so far) — if you've tried a main account, please say so in a PR.
 
+- **FTP, server-dependent absolute-path handling:** files_external's FTP backend always builds
+  absolute paths (e.g. `MKD /repo`) for the configured root, never relative ones. `atmoz/sftp`-style
+  `vsftpd` test servers (chrooted) can reject that with a generic "create directory operation
+  failed", even though a plain `ftp_mkdir()` with a *relative* path on the same server succeeds;
+  `pure-ftpd` accepts the absolute form fine. If a working FTP server rejects ng_backup's writes,
+  try a different FTP server implementation before assuming the backend itself is broken.
+
+- **SMB/CIFS *lists* as available with just the `smbclient` CLI binary, but does not actually
+  work for ng_backup without the `smbclient` PECL extension too.** files_external falls back to a
+  shell-wrapped `smbclient` process when the native extension is missing, which registers the
+  backend in `occ backup:target:backends` fine, but that fallback's stream cannot seek. ng_backup
+  reads blobs back by byte range while backing up, so even the very first (small) backup fails
+  with `Seek failed in packs/...`. Install the extension (`libsmbclient-dev` + `pecl install
+  smbclient` + `docker-php-ext-enable smbclient` on Debian-based images), not just the CLI tool —
+  the backend being listed is not proof it will work here. Once the extension is present it works
+  the same as any other backend; no ng_backup-specific config beyond host/share/user/password.
+
+- **NFS is not a files_external backend at all.** Mount the NFS export on the server yourself
+  (e.g. via `/etc/fstab` or a systemd `.mount` unit) and point ng_backup's `local` backend at the
+  mount point; ng_backup never mounts or unmounts anything on its own, so an NFS mount dropping
+  mid-run behaves like any other local-path failure (the run resumes). See PLAN.md 3.5 for why NFS
+  can't be driven from PHP directly.
+
 ## Commands
 
 | Command | Purpose |

appinfo/info.xml

@@ -47,6 +47,11 @@ relying on this for anything.]]></description>
         <command>OCA\NgBackup\Command\KeySlotAdd</command>
         <command>OCA\NgBackup\Command\KeySlotReplace</command>
         <command>OCA\NgBackup\Command\KeySlotRemove</command>
+        <command>OCA\NgBackup\Command\BackupUser</command>
+        <command>OCA\NgBackup\Command\RestoreUser</command>
+        <command>OCA\NgBackup\Command\KeyImport</command>
+        <command>OCA\NgBackup\Command\RestoreFull</command>
+        <command>OCA\NgBackup\Command\Verify</command>
     </commands>
     <settings>
         <admin>OCA\NgBackup\Settings\Admin</admin>

lib/Command/BackupUser.php

@@ -0,0 +1,59 @@
+<?php
+
+declare(strict_types=1);
+
+// SPDX-FileCopyrightText: 2026 Dillard Blom
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+namespace OCA\NgBackup\Command;
+
+use OCA\NgBackup\Service\TargetService;
+use OCA\NgBackup\Service\UserBackupService;
+use OCP\IUserManager;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+final class BackupUser extends Command {
+	public function __construct(
+		private TargetService $targets,
+		private UserBackupService $userBackup,
+		private IUserManager $userManager,
+	) {
+		parent::__construct();
+	}
+
+	protected function configure(): void {
+		$this->setName('backup:user:backup')
+			->setDescription('Back up one user via user_migration (account, settings, files and everything else a migrator covers)')
+			->addArgument('target', InputArgument::REQUIRED, 'Location name or id')
+			->addArgument('user', InputArgument::REQUIRED, 'User id')
+			->setHelp(<<<'HELP'
+Streams a user_migration export straight into the encrypted repository: no zip, no copy in the
+user's own storage. Shares data with the regular backup; this needs the user_migration app
+enabled. The manifest path this prints is what occ backup:user:restore expects.
+
+Example:
+  occ backup:user:backup offsite alice
+HELP);
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output): int {
+		$uid = (string)$input->getArgument('user');
+		$user = $this->userManager->get($uid);
+		if ($user === null) {
+			$output->writeln("<error>No such user: $uid</error>");
+			return 1;
+		}
+		try {
+			$target = $this->targets->get($input->getArgument('target'));
+			$manifest = $this->userBackup->backupUser($target, $user);
+		} catch (\Throwable $e) {
+			$output->writeln('<error>' . $e->getMessage() . '</error>');
+			return 1;
+		}
+		$output->writeln("Backed up <info>$uid</info> to $manifest.");
+		return 0;
+	}
+}

lib/Command/KeyImport.php

@@ -0,0 +1,77 @@
+<?php
+
+declare(strict_types=1);
+
+// SPDX-FileCopyrightText: 2026 Dillard Blom
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+namespace OCA\NgBackup\Command;
+
+use OCA\NgBackup\Service\KeyService;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Question\Question;
+
+final class KeyImport extends Command {
+	public function __construct(
+		private KeyService $keys,
+	) {
+		parent::__construct();
+	}
+
+	protected function configure(): void {
+		$this->setName('backup:key:import')
+			->setDescription('Disaster recovery: adopt the backup key from a recovery kit on a fresh installation')
+			->addArgument('kit-file', InputArgument::REQUIRED, 'The recovery kit file (occ backup:key:kit on the original installation)')
+			->addOption('passphrase-file', null, InputOption::VALUE_REQUIRED, 'Read the passphrase from this file instead of asking')
+			->setHelp(<<<'HELP'
+For a fresh installation only (occ backup:key:init must not have been run here yet). Reads one
+of the kit's passphrase slots to recover the original master key, so occ backup:target:add opens
+the existing repository on the location instead of creating a new, empty one.
+
+Example:
+  occ backup:key:import /root/ng_backup-recovery-kit.json
+  occ backup:target:add offsite sftp -a password::password -o host=... -o user=... -o password=...
+  occ backup:restore:full offsite <snapshot>
+HELP);
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output): int {
+		if ($this->keys->isInitialized()) {
+			$output->writeln('<error>A backup key already exists here (fingerprint ' . $this->keys->fingerprint() . '). occ backup:key:import is only for a fresh installation.</error>');
+			return 1;
+		}
+		$kitFile = (string)$input->getArgument('kit-file');
+		$raw = @file_get_contents($kitFile);
+		if ($raw === false) {
+			$output->writeln("<error>Cannot read $kitFile</error>");
+			return 1;
+		}
+		try {
+			$kit = json_decode($raw, true, 512, JSON_THROW_ON_ERROR);
+		} catch (\JsonException $e) {
+			$output->writeln('<error>Not a valid recovery kit file: ' . $e->getMessage() . '</error>');
+			return 1;
+		}
+		$file = $input->getOption('passphrase-file');
+		if ($file !== null) {
+			$pass = rtrim((string)@file_get_contents($file), "\r\n");
+		} else {
+			$helper = $this->getHelper('question');
+			$q = (new Question('Passphrase of one of the kit\'s slots: '))->setHidden(true)->setHiddenFallback(false);
+			$pass = (string)$helper->ask($input, $output, $q);
+		}
+		try {
+			$this->keys->importRecoveryKit($kit, $pass);
+		} catch (\Throwable $e) {
+			$output->writeln('<error>' . $e->getMessage() . '</error>');
+			return 1;
+		}
+		$output->writeln('Backup key imported, fingerprint <info>' . $this->keys->fingerprint() . '</info>.');
+		$output->writeln('Next: connect the backup location with the same details as before (<info>occ backup:target:add</info>), then <info>occ backup:list</info> and <info>occ backup:restore:full</info>.');
+		return 0;
+	}
+}

lib/Command/Prune.php

@@ -37,6 +37,20 @@ final class Prune extends Command {
 		$output->writeln('Policy: ' . json_encode($this->prune->policy()->toArray()) . ($dry ? ' (dry run)' : ''));
 		$rc = 0;
 		foreach ($targets as $t) {
+			// User exports first: Repository::prune()'s blob garbage collection (run as part of
+			// apply() below) scans the users/ manifests still on the location at that point, so
+			// forgetting one here lets its now-unused blobs be freed in this same pass.
+			try {
+				$ru = $this->prune->applyUserExports($t, $dry);
+			} catch (\Throwable $e) {
+				$output->writeln('<error>' . $t->getName() . ' (user exports): ' . $e->getMessage() . '</error>');
+				$rc = 1;
+				continue;
+			}
+			if ($ru['forgotten'] !== []) {
+				$output->writeln(sprintf('<info>%s</info>: %s %d user export(s) for %d user(s)',
+					$t->getName(), $dry ? 'would forget' : 'forgot', count($ru['forgotten']), count($ru['kept'])));
+			}
 			try {
 				$r = $this->prune->apply($t, $dry);
 			} catch (\Throwable $e) {

lib/Command/RestoreFull.php

@@ -0,0 +1,71 @@
+<?php
+
+declare(strict_types=1);
+
+// SPDX-FileCopyrightText: 2026 Dillard Blom
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+namespace OCA\NgBackup\Command;
+
+use OCA\NgBackup\Service\RestoreFullService;
+use OCA\NgBackup\Service\TargetService;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+final class RestoreFull extends Command {
+	public function __construct(
+		private TargetService $targets,
+		private RestoreFullService $restoreFull,
+	) {
+		parent::__construct();
+	}
+
+	protected function configure(): void {
+		$this->setName('backup:restore:full')
+			->setDescription('Disaster recovery: restore the database, data directory and config on a fresh installation')
+			->addArgument('target', InputArgument::REQUIRED, 'Location name or id')
+			->addArgument('snapshot', InputArgument::REQUIRED, 'Snapshot id (see backup:list)')
+			->setHelp(<<<'HELP'
+For a FRESH Nextcloud installation only, same major version as the backup, right after
+occ maintenance:install, occ backup:key:import and occ backup:target:add -- before anyone else
+uses this instance.
+
+Every app that was enabled when the snapshot was taken must already be installed here (its
+database tables must exist before the restore can write into them); the command lists what is
+missing and refuses to continue rather than guess.
+
+Steps: the database is replaced (consistent, in one transaction); the data directory is restored
+directly in place; config.php is merged in -- everything from the backup except the database
+connection and data directory settings, which stay as occ maintenance:install configured them
+here. Other files under config/ (if any) are not restored.
+
+Afterwards: check trusted_domains and overwritehost/overwriteprotocol match this server, and
+occ maintenance:repair.
+
+Example:
+  occ backup:restore:full offsite 537bf7e9c1a4...
+HELP);
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output): int {
+		try {
+			$target = $this->targets->get($input->getArgument('target'));
+			$snapshot = (string)$input->getArgument('snapshot');
+			$result = $this->restoreFull->restoreFull($target, $snapshot);
+		} catch (\Throwable $e) {
+			$output->writeln('<error>' . $e->getMessage() . '</error>');
+			return 1;
+		}
+		$output->writeln(sprintf(
+			'Database restored (<info>%d</info> tables, <info>%d</info> unchanged), config merged (<info>%d</info> keys), <info>%d</info> data files restored.',
+			count($result['dbReport']['restored']),
+			count($result['dbReport']['skipped']),
+			$result['configKeys'],
+			$result['dataFiles'],
+		));
+		$output->writeln('Next: check trusted_domains and overwritehost/overwriteprotocol match this server, then occ maintenance:repair.');
+		return 0;
+	}
+}

lib/Command/RestoreUser.php

@@ -0,0 +1,57 @@
+<?php
+
+declare(strict_types=1);
+
+// SPDX-FileCopyrightText: 2026 Dillard Blom
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+namespace OCA\NgBackup\Command;
+
+use OCA\NgBackup\Service\TargetService;
+use OCA\NgBackup\Service\UserRestoreService;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+
+final class RestoreUser extends Command {
+	public function __construct(
+		private TargetService $targets,
+		private UserRestoreService $userRestore,
+	) {
+		parent::__construct();
+	}
+
+	protected function configure(): void {
+		$this->setName('backup:user:restore')
+			->setDescription('Restore a user from a user_migration export (see backup:user:backup)')
+			->addArgument('target', InputArgument::REQUIRED, 'Location name or id')
+			->addArgument('manifest', InputArgument::REQUIRED, 'Manifest path printed by backup:user:backup (users/<uid>/<exportId>)')
+			->addOption('mode', 'm', InputOption::VALUE_REQUIRED, 'replace or as-backup', UserRestoreService::MODE_REPLACE)
+			->setHelp(<<<'HELP'
+Never imports over a live account. Modes:
+  replace    (default) safety-exports the current account first, then deletes and recreates it
+             fresh from the backup, under the same user id
+  as-backup  restores into a new account "<uid>-bak" (or "-bak-2", ...) instead, so an admin can
+             compare and transfer by hand; Nextcloud cannot rename a user id, so the backup gets
+             the new name, never the existing account
+
+Example:
+  occ backup:user:restore offsite users/alice/20261005T120000Z-ab12cd34
+  occ backup:user:restore offsite users/alice/20261005T120000Z-ab12cd34 --mode=as-backup
+HELP);
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output): int {
+		try {
+			$target = $this->targets->get($input->getArgument('target'));
+			$user = $this->userRestore->restoreUser($target, (string)$input->getArgument('manifest'), (string)$input->getOption('mode'));
+		} catch (\Throwable $e) {
+			$output->writeln('<error>' . $e->getMessage() . '</error>');
+			return 1;
+		}
+		$output->writeln('Restored <info>' . $user->getUID() . '</info>.');
+		return 0;
+	}
+}

lib/Command/Retention.php

@@ -28,7 +28,8 @@ final class Retention extends Command {
 			->addOption('daily', null, InputOption::VALUE_REQUIRED, 'Keep one per day for the last N days with a backup')
 			->addOption('weekly', null, InputOption::VALUE_REQUIRED, 'Keep one per week for N weeks')
 			->addOption('monthly', null, InputOption::VALUE_REQUIRED, 'Keep one per month for N months')
-			->setHelp("Example: occ backup:retention --last=3 --daily=7 --weekly=4 --monthly=12");
+			->addOption('user-last', null, InputOption::VALUE_REQUIRED, 'Keep the newest N of each user\'s own exports (occ backup:user:backup)')
+			->setHelp("Example: occ backup:retention --last=3 --daily=7 --weekly=4 --monthly=12 --user-last=3");
 	}
 
 	protected function execute(InputInterface $input, OutputInterface $output): int {
@@ -48,7 +49,16 @@ final class Retention extends Command {
 				return 1;
 			}
 		}
+		if ($input->getOption('user-last') !== null) {
+			try {
+				$this->prune->setUserExportRetention((int)$input->getOption('user-last'));
+			} catch (\InvalidArgumentException $e) {
+				$output->writeln('<error>' . $e->getMessage() . '</error>');
+				return 1;
+			}
+		}
 		$output->writeln(sprintf('Keep the last %d, plus one per day for %d days, per week for %d weeks, per month for %d months.', $p['last'], $p['daily'], $p['weekly'], $p['monthly']));
+		$output->writeln(sprintf('Keep the newest %d of each user\'s own exports.', $this->prune->userExportRetention()));
 		return 0;
 	}
 }

lib/Command/Verify.php

@@ -0,0 +1,75 @@
+<?php
+
+declare(strict_types=1);
+
+// SPDX-FileCopyrightText: 2026 Dillard Blom
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+namespace OCA\NgBackup\Command;
+
+use OCA\NgBackup\Service\TargetService;
+use OCA\NgBackup\Service\VerifyService;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+
+final class Verify extends Command {
+	public function __construct(
+		private TargetService $targets,
+		private VerifyService $verify,
+	) {
+		parent::__construct();
+	}
+
+	protected function configure(): void {
+		$this->setName('backup:verify')
+			->setDescription('Checksum audit of a snapshot: every blob it needs must be in the (freshly re-checked) index and its pack present')
+			->addArgument('target', InputArgument::REQUIRED, 'Location name or id')
+			->addArgument('snapshot', InputArgument::REQUIRED, 'Snapshot id (see backup:list)')
+			->addOption('deep', null, InputOption::VALUE_NONE, 'Also download and decrypt every blob (verifies its authentication tag and content hash, not just that it is listed); much slower')
+			->setHelp(<<<'HELP'
+Without --deep this re-downloads and re-authenticates the index (never trusting the local cache)
+and confirms every blob the snapshot needs is listed and its pack is present -- fast, no blob
+content is read, so it cannot by itself catch a truncated or bit-rotted pack. With --deep every
+blob is also downloaded and decrypted, which fails loudly on exactly that even if the index still
+lists it -- the same verification an actual restore would do, run here deliberately instead of
+waiting to find out during one.
+
+Run this periodically (cron, picking a sample of recent snapshots) rather than only right before
+you'd need to rely on a restore.
+
+Examples:
+  occ backup:verify offsite 537bf7e9c1a4...
+  occ backup:verify offsite 537bf7e9c1a4... --deep
+HELP);
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output): int {
+		try {
+			$target = $this->targets->get($input->getArgument('target'));
+			$ref = (string)$input->getArgument('snapshot');
+			$deep = (bool)$input->getOption('deep');
+			$result = str_starts_with($ref, 'users/')
+				? $this->verify->verifyUserExport($target, $ref, $deep)
+				: $this->verify->verify($target, $ref, $deep);
+		} catch (\Throwable $e) {
+			$output->writeln('<error>' . $e->getMessage() . '</error>');
+			return 1;
+		}
+		$output->writeln(sprintf('%d files, %d blobs checked%s.', $result['filesChecked'], $result['blobsChecked'],
+			$deep ? sprintf(' (%.1f MiB decrypted)', $result['bytesChecked'] / 1048576) : ''));
+		if ($result['missing'] !== []) {
+			$output->writeln('<error>' . count($result['missing']) . ' blob(s) missing from the index:</error> ' . implode(', ', $result['missing']));
+		}
+		if ($result['failed'] !== []) {
+			$output->writeln('<error>' . count($result['failed']) . ' blob(s) failed verification (corrupted or tampered):</error> ' . implode(', ', $result['failed']));
+		}
+		if ($result['missing'] === [] && $result['failed'] === []) {
+			$output->writeln('<info>OK</info>');
+			return 0;
+		}
+		return 1;
+	}
+}

lib/Repository/Catalog.php

@@ -28,6 +28,8 @@ final class Catalog {
 	public array $snapshots = [];
 	/** @var array<string, true> */
 	public array $trash = [];
+	/** @var array<string, true> manifest path => true, for a per-user export (users/<uid>/<exportId>) */
+	public array $userExports = [];
 	public string $hash = '';
 
 	public function __construct(
@@ -39,7 +41,7 @@ final class Catalog {
 	}
 
 	/** Load and verify the newest catalog; create the first one for repositories that have none. */
-	public function load(callable $listSnapshots, callable $listTrash): void {
+	public function load(callable $listSnapshots, callable $listTrash, callable $listUserExports): void {
 		$gens = $this->generations();
 		if ($gens === []) {
 			// First use (new or pre-catalog repository): adopt the current state as generation 1.
@@ -49,6 +51,7 @@ final class Catalog {
 			}
 			$this->snapshots = array_fill_keys($listSnapshots(), true);
 			$this->trash = array_fill_keys($listTrash(), true);
+			$this->userExports = array_fill_keys($listUserExports(), true);
 			$this->write();
 			return;
 		}
@@ -76,6 +79,9 @@ final class Catalog {
 		$this->hash = $hash;
 		$this->snapshots = array_fill_keys($data['snapshots'], true);
 		$this->trash = array_fill_keys($data['trash'], true);
+		// Catalogs written before user exports existed have no such key: default to empty rather
+		// than adopting the location's current users/ listing (that would skip verification).
+		$this->userExports = array_fill_keys($data['userExports'] ?? [], true);
 		$this->anchor?->set($this->repositoryId, $this->gen, $this->hash);
 	}
 
@@ -83,7 +89,8 @@ final class Catalog {
 	public function write(): void {
 		$next = $this->gen + 1;
 		$plain = json_encode(['repository' => $this->repositoryId, 'gen' => $next, 'time' => gmdate('c'), 'prev' => $this->hash,
-			'snapshots' => array_keys($this->snapshots), 'trash' => array_keys($this->trash)], JSON_THROW_ON_ERROR);
+			'snapshots' => array_keys($this->snapshots), 'trash' => array_keys($this->trash),
+			'userExports' => array_keys($this->userExports)], JSON_THROW_ON_ERROR);
 		$encrypted = $this->cipher->encryptString($plain, $this->ad($next));
 		$stream = fopen('php://memory', 'w+b');
 		fwrite($stream, $encrypted);

lib/Repository/Repository.php

@@ -91,7 +91,8 @@ final class Repository {
 		$this->catalog = new Catalog($this->backend, $this->cipher, $this->repositoryId, $anchor);
 		$this->catalog->load(
 			fn () => array_map('basename', $this->backend->list('snapshots')),
-			fn () => array_map('basename', $this->backend->list('trash/info')));
+			fn () => array_map('basename', $this->backend->list('trash/info')),
+			fn () => $this->backend->list('users'));
 	}
 
 	/** Refuse uploads that would make the stored data larger than this (null = no limit). */
@@ -189,8 +190,15 @@ final class Repository {
 		return ['snapshot' => $snapshotId] + $stats;
 	}
 
-	/** Restore a snapshot (or only paths starting with $prefix) into a local directory. */
+	/**
-	public function restore(string $snapshotId, string $target, string $prefix = ''): int {
+	 * Restore a snapshot (or only paths starting with $prefix) into a local directory.
+	 *
+	 * @param bool $stripPrefix write "$target/<path without $prefix>" instead of
+	 *             "$target/<full logical path>" (disaster recovery: restoring e.g. "data/" or
+	 *             "config/" directly into the real data/config directory, not a subdirectory
+	 *             named after the prefix). Ignored when $prefix is '' (nothing to strip).
+	 */
+	public function restore(string $snapshotId, string $target, string $prefix = '', bool $stripPrefix = false): int {
 		if ($prefix !== '' && !self::isSafePath(rtrim($prefix, '/'))) {
 			throw new RepositoryException('Invalid path prefix');
 		}
@@ -199,7 +207,8 @@ final class Repository {
 			if ($prefix !== '' && !str_starts_with($entry['p'], $prefix)) {
 				continue;
 			}
-			$dest = rtrim($target, '/') . '/' . $entry['p'];
+			$relPath = ($stripPrefix && $prefix !== '') ? substr($entry['p'], strlen(rtrim($prefix, '/')) + 1) : $entry['p'];
+			$dest = rtrim($target, '/') . '/' . $relPath;
 			if (!is_dir(dirname($dest))) {
 				mkdir(dirname($dest), 0700, true);
 			}
@@ -374,6 +383,50 @@ final class Repository {
 		$this->backend->delete('trash/info/' . $snapshotId);
 	}
 
+	/** Record a user_migration export's manifest in the catalog (rollback-protected like a snapshot). */
+	public function recordUserExport(string $manifestPath): void {
+		$this->catalog->userExports[$manifestPath] = true;
+		$this->catalog->write();
+	}
+
+	/**
+	 * User export manifests according to the verified catalog, newest first. A manifest the
+	 * catalog lists but the location no longer has means it was deleted or hidden behind NG
+	 * Backup's back, same as a missing snapshot (see listSnapshots()).
+	 *
+	 * @return list<string>
+	 */
+	public function listUserExports(?string $uid = null): array {
+		$prefix = $uid !== null ? 'users/' . $uid . '/' : 'users/';
+		$out = [];
+		foreach (array_keys($this->catalog->userExports) as $path) {
+			if (!str_starts_with($path, $prefix)) {
+				continue;
+			}
+			if (!$this->backend->exists($path)) {
+				throw new RepositoryException("User export $path is missing on the location (deleted or hidden outside NG Backup)");
+			}
+			$out[] = $path;
+		}
+		sort($out, SORT_STRING);
+		return array_reverse($out);
+	}
+
+	/** Whether $manifestPath is a user export the verified catalog actually recorded. */
+	public function isRecordedUserExport(string $manifestPath): bool {
+		return isset($this->catalog->userExports[$manifestPath]);
+	}
+
+	/** Permanently delete a user export. Its blobs are freed by the next prune() like any other. */
+	public function forgetUserExport(string $manifestPath): void {
+		if (!isset($this->catalog->userExports[$manifestPath])) {
+			throw new RepositoryException("$manifestPath is not a recorded user export");
+		}
+		$this->backend->delete($manifestPath);
+		unset($this->catalog->userExports[$manifestPath]);
+		$this->catalog->write();
+	}
+
 	/** @return array<string, array{forgottenAt:int, by:string, db:?string, dbInTrash:?string, time:?string, label:string}> */
 	public function trash(): array {
 		$out = [];
@@ -609,6 +662,117 @@ final class Repository {
 		return $this->streamEntries($snapshotId);
 	}
 
+	/**
+	 * Checksum audit of a snapshot: every blob it references (files and the database dump, when
+	 * the snapshot has one) must be in the index, freshly re-downloaded and re-authenticated from
+	 * the location rather than trusted from the local cache (same reasoning as prune()), and its
+	 * pack must still be present. With $deep, each blob is also downloaded and decrypted, which
+	 * verifies its AEAD authentication tag and its content hash against the blob id (loadBlob()
+	 * already does both on every real read -- this just does it for everything in the snapshot,
+	 * deliberately, rather than relying on it to come up during a later restore). A blob
+	 * referenced by more than one file is only checked once; a missing database manifest is a
+	 * failure, not something to silently skip over.
+	 *
+	 * @param ?callable $heartbeat called after every blob (shallow) or every blob read (deep);
+	 *        callers use it to keep a time-boxed lease alive during a large audit
+	 * @return array{filesChecked:int, blobsChecked:int, bytesChecked:int, missing:list<string>, failed:list<string>}
+	 */
+	public function verify(string $snapshotId, bool $deep = false, ?callable $heartbeat = null): array {
+		$heartbeat ??= static function (): void {
+		};
+		$this->index->load(true);
+		$stats = ['filesChecked' => 0, 'blobsChecked' => 0, 'bytesChecked' => 0, 'missing' => [], 'failed' => []];
+		$seen = [];
+		$packSeen = []; // pack id => exists on the backend; avoids one exists() call per blob
+		foreach ($this->streamEntries($snapshotId) as $entry) {
+			$stats['filesChecked']++;
+			foreach ($entry['b'] as $id) {
+				if (isset($seen[$id])) {
+					continue;
+				}
+				$seen[$id] = true;
+				$this->verifyBlob($id, $deep, $stats, $packSeen);
+				$heartbeat();
+			}
+		}
+		$meta = $this->snapshotMeta($snapshotId);
+		if (isset($meta['db']) && is_string($meta['db'])) {
+			if (!$this->backend->exists($meta['db'])) {
+				$stats['missing'][] = $meta['db'];
+			} else {
+				$dbManifest = json_decode($this->getObject($meta['db']), true, 512, JSON_THROW_ON_ERROR);
+				foreach ($dbManifest['tables'] as $info) {
+					foreach ($info['blobs'] as $id) {
+						if (isset($seen[$id])) {
+							continue;
+						}
+						$seen[$id] = true;
+						$this->verifyBlob($id, $deep, $stats, $packSeen);
+						$heartbeat();
+					}
+				}
+			}
+		}
+		return $stats;
+	}
+
+	/**
+	 * Same checks as verify(), for a user export: every blob its manifest references must be in
+	 * the freshly re-authenticated index with its pack present; $deep also decrypts each.
+	 *
+	 * @return array{filesChecked:int, blobsChecked:int, bytesChecked:int, missing:list<string>, failed:list<string>}
+	 */
+	public function verifyUserExport(string $manifestPath, bool $deep = false, ?callable $heartbeat = null): array {
+		if (!$this->isRecordedUserExport($manifestPath)) {
+			throw new RepositoryException("$manifestPath is not a recorded user export for this location");
+		}
+		$heartbeat ??= static function (): void {
+		};
+		$this->index->load(true);
+		$stats = ['filesChecked' => 0, 'blobsChecked' => 0, 'bytesChecked' => 0, 'missing' => [], 'failed' => []];
+		$seen = [];
+		$packSeen = [];
+		$manifest = json_decode($this->getObject($manifestPath), true, 512, JSON_THROW_ON_ERROR);
+		foreach ($manifest['entries'] as $entry) {
+			if (($entry['t'] ?? '') !== 'f') {
+				continue;
+			}
+			$stats['filesChecked']++;
+			foreach ($entry['b'] ?? [] as $id) {
+				if (isset($seen[$id])) {
+					continue;
+				}
+				$seen[$id] = true;
+				$this->verifyBlob($id, $deep, $stats, $packSeen);
+				$heartbeat();
+			}
+		}
+		return $stats;
+	}
+
+	/** @param array<string, bool> $packSeen */
+	private function verifyBlob(string $id, bool $deep, array &$stats, array &$packSeen): void {
+		if (!$this->index->has($id)) {
+			$stats['missing'][] = $id;
+			return;
+		}
+		[$pack] = $this->index->get($id);
+		$packExists = $packSeen[$pack] ??= $this->backend->exists('packs/' . substr($pack, 0, 2) . '/' . $pack);
+		if (!$packExists) {
+			$stats['missing'][] = $id;
+			return;
+		}
+		$stats['blobsChecked']++;
+		if (!$deep) {
+			return;
+		}
+		try {
+			$stats['bytesChecked'] += strlen($this->loadBlob($id));
+		} catch (\Throwable) {
+			$stats['failed'][] = $id;
+		}
+	}
+
 	/** The meta record (first line) of a snapshot. */
 	public function snapshotMeta(string $snapshotId): array {
 		$plain = fopen('php://temp/maxmemory:' . (4 * 1048576), 'w+b');

lib/Service/KeyService.php

@@ -71,6 +71,84 @@ final class KeyService {
 		$this->cached = $keys;
 	}
 
+	/**
+	 * Disaster recovery on a fresh installation: adopt the master key from a recovery kit
+	 * (occ backup:key:kit on the original installation) instead of generating a new one.
+	 * Afterwards occ backup:target:add opens the existing repository on the location with this
+	 * key, instead of creating a new, empty one.
+	 *
+	 * @param array<string, mixed> $kit as produced by recoveryKit()
+	 * @throws \OCA\NgBackup\Crypto\CryptoException wrong passphrase, or a damaged/foreign kit
+	 */
+	public function importRecoveryKit(array $kit, #[\SensitiveParameter] string $passphrase): void {
+		if ($this->isInitialized()) {
+			throw new \RuntimeException('A backup key already exists');
+		}
+		if (!isset($kit['wrapped_key'])) {
+			throw new \InvalidArgumentException('Not a NG Backup recovery kit file');
+		}
+		$keys = KeyRing::unwrapAny($kit['wrapped_key'], $passphrase);
+		$this->appConfig->setValueString(Application::APP_ID, self::KEY_MASTER,
+			$this->crypto->encrypt(base64_encode($keys->exportMasterKey())), true, true);
+		$this->cached = $keys;
+		$this->appConfig->setValueString(Application::APP_ID, self::KEY_WRAPPED, json_encode($kit['wrapped_key'], JSON_THROW_ON_ERROR), true, true);
+		$this->appConfig->setValueString(Application::APP_ID, self::KEY_FINGERPRINT, $this->fingerprintOf($keys), true);
+		$this->appConfig->setValueInt(Application::APP_ID, self::KEY_DELETE_DELAY, self::DEFAULT_DELETE_DELAY, true);
+		$this->appConfig->setValueInt(Application::APP_ID, self::KEY_KIT_VERSION, (int)($kit['kit_version'] ?? 1), true);
+		// Having and successfully using a real kit file is stronger proof than the normal
+		// download-and-confirm flow it replaces.
+		$this->confirmRecoveryKit('cli-import');
+	}
+
+	/**
+	 * The master key and the recovery kit code are stored encrypted with Nextcloud's own
+	 * instance secret (ICrypto), not with themselves; the wrapped key is not (it is sealed with
+	 * the admin's passphrase instead), but Nextcloud's own AppConfig additionally encrypts any
+	 * "sensitive" value with the instance secret regardless, underneath whatever we store. So
+	 * changing that secret (occ backup:restore:full merging config.php) would otherwise leave
+	 * all three permanently undecryptable. Call $applySecretChange (which must be the only thing
+	 * that changes the secret) through here instead: all three are decrypted first, then
+	 * re-encrypted under whatever secret is active once $applySecretChange returns.
+	 *
+	 * Not crash-safe: a process kill between the delete and the re-save of one of these keys
+	 * would leave it missing rather than merely stale. Disaster recovery is run once, by hand,
+	 * right after occ maintenance:install; a dedicated two-phase write is not justified yet for
+	 * that narrow a window.
+	 */
+	public function reencryptForSecretRotation(callable $applySecretChange): mixed {
+		$master = $this->appConfig->getValueString(Application::APP_ID, self::KEY_MASTER, '', true);
+		$wrapped = $this->appConfig->getValueString(Application::APP_ID, self::KEY_WRAPPED, '', true);
+		$kitCodeRaw = $this->appConfig->getValueString(Application::APP_ID, self::KEY_KIT_CODE, '', true);
+		$kitCode = $kitCodeRaw !== '' ? json_decode($kitCodeRaw, true, 512, JSON_THROW_ON_ERROR) : null;
+		$masterPlain = $master !== '' ? $this->crypto->decrypt($master) : null;
+		$kitCodePlain = $kitCode !== null && isset($kitCode['code']) ? $this->crypto->decrypt($kitCode['code']) : null;
+
+		$result = $applySecretChange();
+		$this->cached = null; // the master key is about to be re-saved; do not keep the pre-rotation copy
+
+		// Nextcloud's own AppConfig additionally encrypts a "sensitive" value itself (tied to
+		// the same secret, underneath our own encrypt() above); setValueString() on an existing
+		// key reads the old value first to compare, which would try to decrypt it with the new
+		// secret and fail the same way. Delete first so there is nothing to compare against.
+		if ($masterPlain !== null) {
+			$this->appConfig->deleteKey(Application::APP_ID, self::KEY_MASTER);
+			$this->appConfig->setValueString(Application::APP_ID, self::KEY_MASTER, $this->crypto->encrypt($masterPlain), true, true);
+		}
+		if ($wrapped !== '') {
+			// Already plaintext JSON here: getValueString() above transparently undid
+			// AppConfig's own sensitive-value encryption; there is no encrypt() of our own to
+			// redo (wrapping is sealed with the passphrase, not the instance secret).
+			$this->appConfig->deleteKey(Application::APP_ID, self::KEY_WRAPPED);
+			$this->appConfig->setValueString(Application::APP_ID, self::KEY_WRAPPED, $wrapped, true, true);
+		}
+		if ($kitCodePlain !== null) {
+			$kitCode['code'] = $this->crypto->encrypt($kitCodePlain);
+			$this->appConfig->deleteKey(Application::APP_ID, self::KEY_KIT_CODE);
+			$this->appConfig->setValueString(Application::APP_ID, self::KEY_KIT_CODE, json_encode($kitCode, JSON_THROW_ON_ERROR), true, true);
+		}
+		return $result;
+	}
+
 	public function keyRing(): KeyRing {
 		if ($this->cached === null) {
 			$enc = $this->appConfig->getValueString(Application::APP_ID, self::KEY_MASTER, '', true);

lib/Service/PruneService.php

@@ -98,6 +98,83 @@ final class PruneService {
 		return 'ng_backup/target/' . $target->getId();
 	}
 
+	/**
+	 * A separate, short-lived exclusive lock serializing writes to the catalog itself. The
+	 * per-target lock above only keeps readers/writers out while a cleanup runs; it does not
+	 * stop two SHARED holders (e.g. two concurrent per-user backups, or one alongside a full
+	 * backup) from both reading the same catalog generation and racing to write the next one,
+	 * silently dropping whichever's change loses. The full-backup path avoids this today only
+	 * because a Run row makes concurrent runs for the same target mutually exclusive; per-user
+	 * backup/restore has no such row, so it takes this lock around the catalog write itself.
+	 */
+	public static function catalogLockKey(Target $target): string {
+		return self::lockKey($target) . '/catalog';
+	}
+
+	/** How many of each user's own exports (occ backup:user:backup) to keep, newest first. */
+	public function userExportRetention(): int {
+		return $this->appConfig->getValueInt(Application::APP_ID, 'user_export_retention', 3);
+	}
+
+	public function setUserExportRetention(int $keep): void {
+		if ($keep < 1) {
+			throw new \InvalidArgumentException('Keep at least the last export');
+		}
+		$old = $this->userExportRetention();
+		$this->appConfig->setValueInt(Application::APP_ID, 'user_export_retention', $keep);
+		if ($old !== $keep) {
+			$this->alerts->securityEvent('user_export_retention_changed', ['keep' => (string)$keep]);
+		}
+	}
+
+	/**
+	 * Forgets a user's older exports once more than userExportRetention() exist for them,
+	 * newest first; no trash, unlike a full snapshot (occ backup:user:backup is on-demand, not
+	 * yet the primary safety net the deletion delay protects).
+	 *
+	 * @return array{kept: array<string, list<string>>, forgotten: list<string>}
+	 */
+	public function applyUserExports(Target $target, bool $dryRun = false): array {
+		if ($target->getAppendOnly()) {
+			throw new \RuntimeException('Location ' . $target->getName() . ' is append-only: NG Backup does not delete anything there');
+		}
+		$lease = $this->lockExclusive($target, 1800);
+		try {
+			$repo = $this->targets->repository($target);
+			$keep = $this->userExportRetention();
+			$byUser = [];
+			foreach ($repo->listUserExports() as $path) {
+				$uid = explode('/', $path)[1] ?? '';
+				$manifest = json_decode($repo->getObject($path), true, 512, JSON_THROW_ON_ERROR);
+				$byUser[$uid][$path] = (int)strtotime((string)($manifest['time'] ?? '@0'));
+			}
+			$kept = [];
+			$forget = [];
+			foreach ($byUser as $uid => $times) {
+				arsort($times);
+				$i = 0;
+				foreach (array_keys($times) as $path) {
+					if ($i++ < $keep) {
+						$kept[$uid][] = $path;
+					} else {
+						$forget[] = $path;
+					}
+				}
+			}
+			if (!$dryRun) {
+				foreach ($forget as $path) {
+					$repo->forgetUserExport($path);
+				}
+				if ($forget !== []) {
+					$this->alerts->securityEvent('user_exports_forgotten', ['target' => $target->getName(), 'count' => (string)count($forget)], false);
+				}
+			}
+			return ['kept' => $kept, 'forgotten' => $forget];
+		} finally {
+			$this->leases->release($lease);
+		}
+	}
+
 	public function policy(): RetentionPolicy {
 		return RetentionPolicy::fromArray(json_decode($this->appConfig->getValueString(Application::APP_ID, 'retention', '{}'), true) ?: []);
 	}

lib/Service/RestoreFullService.php

@@ -0,0 +1,225 @@
+<?php
+
+declare(strict_types=1);
+
+// SPDX-FileCopyrightText: 2026 Dillard Blom
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+namespace OCA\NgBackup\Service;
+
+use OCA\NgBackup\Db\DbDumper;
+use OCA\NgBackup\Db\Target;
+use OCP\App\IAppManager;
+use OCP\IConfig;
+use OCP\IDBConnection;
+use OCP\Lock\LockedException;
+
+/**
+ * Disaster recovery on a fresh Nextcloud installation (same major version): replace the
+ * database, restore the data directory and merge the backed-up config.php, see PLAN.md 3.7.
+ *
+ * Deliberately NOT handled yet (phase 3): restoring in place over a live, already-used
+ * installation. The admin is expected to run this once, right after occ maintenance:install and
+ * occ backup:key:import/backup:target:add, before anyone else touches the instance.
+ */
+final class RestoreFullService {
+	/**
+	 * Config keys that must keep pointing at THIS installation's actual, already-working
+	 * database and data directory (set by occ maintenance:install), never at the old server's.
+	 */
+	private const CONNECTION_KEYS = [
+		'dbtype', 'dbhost', 'dbport', 'dbname', 'dbuser', 'dbpassword', 'dbpersistent',
+		'dbtableprefix', 'dbdriveroptions', 'datadirectory',
+	];
+
+	public function __construct(
+		private TargetService $targets,
+		private RestoreService $restore,
+		private LeaseService $leases,
+		private IConfig $config,
+		private IDBConnection $db,
+		private IAppManager $appManager,
+		private KeyService $keys,
+	) {
+	}
+
+	/**
+	 * Whether this installation can receive $snapshotId: same Nextcloud major version, and every
+	 * app that was enabled at backup time already installed here (its tables must exist before
+	 * the database restore can write into them).
+	 *
+	 * @return array{ok:bool, currentMajor:string, snapshotMajor:string, missingApps:list<string>}
+	 */
+	public function checkCompatibility(Target $target, string $snapshotId): array {
+		$meta = $this->targets->repository($target)->snapshotMeta($snapshotId);
+		$currentMajor = explode('.', $this->config->getSystemValueString('version'))[0];
+		$snapshotMajor = explode('.', (string)($meta['nextcloud'] ?? ''))[0];
+		$enabled = array_flip($this->appManager->getEnabledApps());
+		$missingApps = array_values(array_diff(array_keys($meta['apps'] ?? []), array_keys($enabled)));
+		return [
+			'ok' => $currentMajor === $snapshotMajor && $missingApps === [],
+			'currentMajor' => $currentMajor,
+			'snapshotMajor' => $snapshotMajor,
+			'missingApps' => $missingApps,
+		];
+	}
+
+	/** @return array{dbReport:array, dataFiles:int, configKeys:int} */
+	public function restoreFull(Target $target, string $snapshotId): array {
+		$check = $this->checkCompatibility($target, $snapshotId);
+		if (!$check['ok']) {
+			throw new \RuntimeException($this->describeBlockers($check));
+		}
+		return $this->withSharedLock($target, function () use ($target, $snapshotId) {
+			$repo = $this->targets->repository($target);
+			$meta = $repo->snapshotMeta($snapshotId);
+
+			$dbReport = null;
+			if (isset($meta['db'])) {
+				$manifest = json_decode($repo->getObject($meta['db']), true, 512, JSON_THROW_ON_ERROR);
+				$prefix = $this->config->getSystemValueString('dbtableprefix', 'oc_');
+				// ng_backup's own tables (and its own rows in the shared appconfig table) must
+				// survive this restore untouched: they describe the backup/key/target that is
+				// actively performing it right now, on THIS installation, not the one that was
+				// backed up. Overwriting them mid-restore would pull the rug from under it.
+				foreach (array_keys($manifest['tables']) as $table) {
+					/** @var string $table */
+					if (str_starts_with($table, $prefix . 'ngb_')) {
+						unset($manifest['tables'][$table]);
+					}
+				}
+				// Sequences are keyed separately from tables; excluding a table does not exclude
+				// its sequence, which would otherwise rewind a retained ngb_* table's sequence
+				// below its current ids (PostgreSQL only -- see DbDumper::restoreSequences()).
+				foreach (array_keys($manifest['sequences'] ?? []) as $seq) {
+					/** @var string $seq */
+					if (str_starts_with((string)($manifest['sequences'][$seq]['table'] ?? ''), $prefix . 'ngb_')) {
+						unset($manifest['sequences'][$seq]);
+					}
+				}
+				$ownAppConfig = $this->preserveOwnAppConfig();
+				$dumper = new DbDumper($this->db->getInner(), $prefix);
+				try {
+					$dumper->restore($repo, $manifest, $dbReport);
+				} finally {
+					$this->restoreOwnAppConfig($ownAppConfig);
+				}
+			}
+
+			// Read (but do not yet apply) the backed-up config.php before touching the data
+			// directory: once applied, 'secret' may differ from what ng_backup's own Target
+			// options were encrypted with (see restoreFull()'s docblock), and every further
+			// repository access through $this->targets would fail to decrypt them.
+			$backupConfig = $this->fetchBackupConfig($target, $snapshotId);
+
+			$dataDir = rtrim($this->config->getSystemValueString('datadirectory'), '/');
+			$dataFiles = $this->restore->restoreToDirectory($target, $snapshotId, 'data', $dataDir, stripPrefix: true);
+
+			// Last step: nothing after this may need $this->targets->repository($target) again.
+			if ($backupConfig !== []) {
+				$this->targets->reencryptOptionsAround(
+					fn (): mixed => $this->keys->reencryptForSecretRotation(fn (): mixed => $this->config->setSystemValues($backupConfig)),
+				);
+			}
+
+			return ['dbReport' => $dbReport ?? ['skipped' => [], 'restored' => []], 'dataFiles' => $dataFiles, 'configKeys' => count($backupConfig)];
+		});
+	}
+
+	/** @return array<string, mixed> config.php's $CONFIG from the backup, minus the connection keys */
+	private function fetchBackupConfig(Target $target, string $snapshotId): array {
+		$tmp = sys_get_temp_dir() . '/ngb-restore-config-' . bin2hex(random_bytes(6));
+		try {
+			$this->restore->restoreToDirectory($target, $snapshotId, 'config', $tmp, stripPrefix: true);
+			$path = $tmp . '/config.php';
+			if (!is_file($path)) {
+				return []; // nothing to merge; the live config.php stays as occ maintenance:install made it
+			}
+			$backupConfig = (static function () use ($path): array {
+				$CONFIG = [];
+				include $path;
+				return $CONFIG;
+			})();
+			foreach (self::CONNECTION_KEYS as $key) {
+				unset($backupConfig[$key]);
+			}
+			return $backupConfig;
+		} finally {
+			$this->rmrf($tmp);
+		}
+	}
+
+	/** @return list<array<string, mixed>> raw appconfig rows (appid, configkey, configvalue, type, lazy) */
+	private function preserveOwnAppConfig(): array {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('*')->from('appconfig')
+			->where($qb->expr()->eq('appid', $qb->createNamedParameter(\OCA\NgBackup\AppInfo\Application::APP_ID)));
+		/** @var list<array<string, mixed>> */
+		return $qb->executeQuery()->fetchAll();
+	}
+
+	/**
+	 * @param list<array<string, mixed>> $rows raw appconfig rows, as returned by preserveOwnAppConfig()
+	 *
+	 * Runs in its own transaction (DbDumper::restore() already committed its own by the time
+	 * this is called): not a full guarantee against a crash spanning both, but means this step
+	 * itself cannot leave ng_backup's appconfig rows half deleted, half reinserted.
+	 */
+	private function restoreOwnAppConfig(array $rows): void {
+		$this->db->beginTransaction();
+		try {
+			$qb = $this->db->getQueryBuilder();
+			$qb->delete('appconfig')
+				->where($qb->expr()->eq('appid', $qb->createNamedParameter(\OCA\NgBackup\AppInfo\Application::APP_ID)));
+			$qb->executeStatement();
+			foreach ($rows as $row) {
+				$ins = $this->db->getQueryBuilder();
+				$ins->insert('appconfig')->values([
+					'appid' => $ins->createNamedParameter($row['appid']),
+					'configkey' => $ins->createNamedParameter($row['configkey']),
+					'configvalue' => $ins->createNamedParameter($row['configvalue']),
+					'type' => $ins->createNamedParameter($row['type'], \OCP\DB\QueryBuilder\IQueryBuilder::PARAM_INT),
+					'lazy' => $ins->createNamedParameter($row['lazy'], \OCP\DB\QueryBuilder\IQueryBuilder::PARAM_INT),
+				]);
+				$ins->executeStatement();
+			}
+			$this->db->commit();
+		} catch (\Throwable $e) {
+			$this->db->rollBack();
+			throw $e;
+		}
+	}
+
+	private function rmrf(string $dir): void {
+		if (!is_dir($dir)) {
+			return;
+		}
+		foreach (new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($dir, \FilesystemIterator::SKIP_DOTS), \RecursiveIteratorIterator::CHILD_FIRST) as $f) {
+			$f->isDir() ? rmdir($f->getPathname()) : unlink($f->getPathname());
+		}
+		rmdir($dir);
+	}
+
+	private function describeBlockers(array $check): string {
+		$parts = [];
+		if ($check['currentMajor'] !== $check['snapshotMajor']) {
+			$parts[] = "this installation is Nextcloud {$check['currentMajor']}, the backup is from {$check['snapshotMajor']} (same major version required)";
+		}
+		if ($check['missingApps'] !== []) {
+			$parts[] = 'install these apps first (their tables must exist before the database restore can use them): '
+				. implode(', ', array_map(fn (string $a) => "occ app:install $a", $check['missingApps']));
+		}
+		return implode('; ', $parts);
+	}
+
+	private function withSharedLock(Target $target, callable $fn): mixed {
+		try {
+			// No progress from DbDumper::restore()/Repository::restore() to refresh this lease
+			// against; a very large instance could in theory outrun this TTL (same limitation as
+			// RestoreService::restoreToDirectory(), see also UserBackupService).
+			return $this->leases->with(PruneService::lockKey($target), LeaseService::SHARED, 7200, $fn);
+		} catch (LockedException) {
+			throw new \RuntimeException('A cleanup of ' . $target->getName() . ' is in progress; try again later');
+		}
+	}
+}

lib/Service/RestoreService.php

@@ -149,15 +149,21 @@ final class RestoreService {
 		return ['restored' => $restored, 'trashed' => $trashed, 'target' => $uid . ':' . $userFolder->getRelativePath($dest->getPath())];
 	}
 
-	/** Raw restore of any snapshot path to a local directory (administrators, disaster recovery). */
+	/**
-	public function restoreToDirectory(Target $target, string $snapshotId, string $prefix, string $directory): int {
+	 * Raw restore of any snapshot path to a local directory (administrators, disaster recovery).
+	 *
+	 * @param bool $stripPrefix write into $directory itself instead of $directory/$prefix (see
+	 *             Repository::restore()); used to restore "data/" or "config/" straight into the
+	 *             real data/config directory for occ backup:restore:full.
+	 */
+	public function restoreToDirectory(Target $target, string $snapshotId, string $prefix, string $directory, bool $stripPrefix = false): int {
 		if ($prefix !== '' && !Repository::isSafePath($prefix)) {
 			throw new \InvalidArgumentException('Invalid path: ' . $prefix);
 		}
 		if (!is_dir($directory) && !mkdir($directory, 0750, true) && !is_dir($directory)) {
 			throw new \RuntimeException("Cannot create $directory");
 		}
-		return $this->withSharedLock($target, fn () => $this->targets->repository($target)->restore($snapshotId, $directory, trim($prefix, '/') === '' ? '' : trim($prefix, '/') . '/'), 3600);
+		return $this->withSharedLock($target, fn () => $this->targets->repository($target)->restore($snapshotId, $directory, trim($prefix, '/') === '' ? '' : trim($prefix, '/') . '/', $stripPrefix), 3600);
 	}
 
 	private function writeFile(Repository $repo, Folder $dest, string $relPath, array $entry): void {

lib/Service/TargetService.php

@@ -10,10 +10,13 @@ namespace OCA\NgBackup\Service;
 use OCA\NgBackup\Backend\ExternalStorageFactory;
 use OCA\NgBackup\Backend\IBackend;
 use OCA\NgBackup\Backend\StorageBackend;
+use OCA\NgBackup\Db\Snapshot;
+use OCA\NgBackup\Db\SnapshotMapper;
 use OCA\NgBackup\Db\Target;
 use OCA\NgBackup\Db\TargetMapper;
 use OCA\NgBackup\Repository\Repository;
 use OCP\App\IAppManager;
+use OCP\AppFramework\Db\DoesNotExistException;
 use OCP\Security\ICrypto;
 use OCP\Server;
 
@@ -30,6 +33,7 @@ final class TargetService {
 		private IAppManager $appManager,
 		private \OCA\NgBackup\Db\DbIndexCache $indexCache,
 		private \OCA\NgBackup\Db\AppConfigCatalogAnchor $anchor,
+		private SnapshotMapper $snapshots,
 	) {
 	}
 
@@ -49,6 +53,12 @@ final class TargetService {
 		if (!preg_match('/^[A-Za-z0-9][A-Za-z0-9 _.-]{0,63}$/', $name)) {
 			throw new \InvalidArgumentException('Name: letters, digits, space, _ . - (max 64)');
 		}
+		// Without the native extension files_external falls back to the smbclient binary, which
+		// registers fine but cannot seek: the first backup then fails with "Seek failed". Refuse
+		// up front instead of letting the admin find out from a failed run.
+		if ($backend === 'smb' && !extension_loaded('smbclient')) {
+			throw new \InvalidArgumentException('The SMB backend needs the PHP smbclient extension (pecl install smbclient); the smbclient binary alone cannot seek and every backup would fail');
+		}
 		try {
 			$this->mapper->findByName($name);
 			throw new \InvalidArgumentException("A target named '$name' already exists");
@@ -78,7 +88,62 @@ final class TargetService {
 		$target->setBasePath(trim($basePath, '/'));
 		$target->setRepositoryId($repo->id());
 		$target->setCreatedAt(time());
-		return ['target' => $this->mapper->insert($target), 'created' => $created];
+		$target = $this->mapper->insert($target);
+		if (!$created) {
+			// Disaster recovery: occ backup:list reads this local cache, not the repository
+			// directly, so a snapshot made by another installation must be backfilled here too.
+			$this->adoptSnapshots($target, $repo);
+		}
+		return ['target' => $target, 'created' => $created];
+	}
+
+	/**
+	 * A target's options are encrypted with Nextcloud's own instance secret (ICrypto), not
+	 * ng_backup's key, so changing that secret (occ backup:restore:full merging config.php)
+	 * would otherwise leave every target permanently undecryptable. Call $applySecretChange
+	 * (which must be the only thing that changes the secret) through here instead: every
+	 * target's options are decrypted first, then re-encrypted under whatever secret is active
+	 * once $applySecretChange returns.
+	 */
+	public function reencryptOptionsAround(callable $applySecretChange): mixed {
+		$plain = [];
+		foreach ($this->mapper->findAll() as $target) {
+			$plain[$target->getId()] = $this->options($target);
+		}
+		$result = $applySecretChange();
+		foreach ($this->mapper->findAll() as $target) {
+			if (!isset($plain[$target->getId()])) {
+				continue; // added by $applySecretChange itself; nothing to re-encrypt
+			}
+			$target->setOptions($this->crypto->encrypt(json_encode($plain[$target->getId()], JSON_THROW_ON_ERROR)));
+			$this->mapper->update($target);
+		}
+		return $result;
+	}
+
+	private function adoptSnapshots(Target $target, Repository $repo): void {
+		foreach ($repo->listSnapshots() as $snapshotId) {
+			try {
+				$this->snapshots->findOne($target->getId(), $snapshotId);
+				continue; // already known locally
+			} catch (DoesNotExistException) {
+			}
+			// One unreadable/corrupt snapshot must not stop the rest of the location's
+			// snapshots from being backfilled, nor abort adding the target itself.
+			try {
+				$meta = $repo->snapshotMeta($snapshotId);
+				$s = new Snapshot();
+				$s->setTargetId($target->getId());
+				$s->setSnapshotId($snapshotId);
+				$s->setKind((string)($meta['kind'] ?? 'full'));
+				$s->setLabel(($meta['label'] ?? '') !== '' ? $meta['label'] : null);
+				$s->setCreatedAt((int)strtotime((string)($meta['time'] ?? 'now')));
+				$s->setFiles((int)($meta['stats']['files'] ?? 0));
+				$s->setBytes((int)($meta['stats']['bytes'] ?? 0));
+				$this->snapshots->insert($s);
+			} catch (\Throwable) {
+			}
+		}
 	}
 
 	/** @return list<Target> */

lib/Service/UserBackupService.php

@@ -0,0 +1,69 @@
+<?php
+
+declare(strict_types=1);
+
+// SPDX-FileCopyrightText: 2026 Dillard Blom
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+namespace OCA\NgBackup\Service;
+
+use OCA\NgBackup\Db\Target;
+use OCA\NgBackup\UserMigration\RepositoryExportDestination;
+use OCA\NgBackup\UserMigration\UserMigrationServiceLocator;
+use OCP\IUser;
+use OCP\Lock\LockedException;
+use OCP\UserMigration\UserMigrationException;
+
+/**
+ * Per-user backup via user_migration: every registered migrator's export streams straight into
+ * the encrypted repository (no zip, no copy in the user's own storage, see
+ * RepositoryExportDestination). Shares blobs with the full backup; prune() keeps a user export's
+ * blobs referenced through its manifest under users/<uid>/.
+ *
+ * user_migration is an optional dependency (unlike files_external): without it, only this
+ * per-user backup/restore is unavailable, the full backup still works.
+ */
+final class UserBackupService {
+	public function __construct(
+		private TargetService $targets,
+		private LeaseService $leases,
+		private UserMigrationServiceLocator $locator,
+	) {
+	}
+
+	/** @throws UserMigrationException when user_migration is not enabled, or the export itself fails */
+	public function backupUser(Target $target, IUser $user): string {
+		$service = $this->locator->get();
+		return $this->withSharedLock($target, function () use ($target, $user, $service) {
+			$repo = $this->targets->repository($target);
+			$dest = new RepositoryExportDestination($repo, $user->getUID());
+			$service->export($dest, $user);
+			// A short exclusive lock around the catalog write only: the shared lock above
+			// allows another concurrent backup (full or per-user) to be reading the same
+			// catalog generation at the same time, and both writing the next one would let
+			// one silently overwrite the other's addition.
+			$this->withCatalogLock($target, fn () => $repo->recordUserExport($dest->manifestPath()));
+			return $dest->manifestPath();
+		});
+	}
+
+	private function withSharedLock(Target $target, callable $fn): mixed {
+		try {
+			// UserMigrationService::export() exposes no progress, so unlike
+			// RestoreService::restoreUserFiles() this lease cannot be refreshed mid-call; a very
+			// large account could in theory outrun this TTL. Resumable, step-based per-user
+			// backup (like the main BackupService run) is a possible future improvement.
+			return $this->leases->with(PruneService::lockKey($target), LeaseService::SHARED, 3600, $fn);
+		} catch (LockedException) {
+			throw new \RuntimeException('A cleanup of ' . $target->getName() . ' is in progress; try again later');
+		}
+	}
+
+	private function withCatalogLock(Target $target, callable $fn): mixed {
+		try {
+			return $this->leases->with(PruneService::catalogLockKey($target), LeaseService::EXCLUSIVE, 30, $fn);
+		} catch (LockedException) {
+			throw new \RuntimeException('Another catalog write for ' . $target->getName() . ' is in progress; try again');
+		}
+	}
+}

lib/Service/UserRestoreService.php

@@ -0,0 +1,137 @@
+<?php
+
+declare(strict_types=1);
+
+// SPDX-FileCopyrightText: 2026 Dillard Blom
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+namespace OCA\NgBackup\Service;
+
+use OCA\NgBackup\Db\Target;
+use OCA\NgBackup\UserMigration\RepositoryExportDestination;
+use OCA\NgBackup\UserMigration\RepositoryImportSource;
+use OCA\NgBackup\UserMigration\UserMigrationServiceLocator;
+use OCP\EventDispatcher\IEventDispatcher;
+use OCP\Files\Events\Node\FilesystemTornDownEvent;
+use OCP\IUser;
+use OCP\IUserManager;
+use OCP\Lock\LockedException;
+use OCP\Security\ISecureRandom;
+use OCP\UserMigration\UserMigrationException;
+
+/**
+ * Restoring a user from a user_migration export (see UserBackupService), never over an existing
+ * account:
+ *  - replace: a safety export of the current state goes into the repository first, then the
+ *    account is deleted and recreated fresh from the backup, under the same uid;
+ *  - as-backup: the backup is restored into a new account "<uid>-bak" (or "-bak-2", ...) instead,
+ *    so an admin can compare and transfer by hand. Nextcloud cannot rename a uid, so the *backup*
+ *    gets the new name, never the existing account.
+ */
+final class UserRestoreService {
+	public const MODE_REPLACE = 'replace';
+	public const MODE_AS_BACKUP = 'as-backup';
+
+	public function __construct(
+		private TargetService $targets,
+		private LeaseService $leases,
+		private UserMigrationServiceLocator $locator,
+		private IUserManager $userManager,
+		private ISecureRandom $random,
+		private IEventDispatcher $events,
+	) {
+	}
+
+	/** @throws UserMigrationException when user_migration is not enabled, or the restore itself fails */
+	public function restoreUser(Target $target, string $manifestPath, string $mode = self::MODE_REPLACE): IUser {
+		$service = $this->locator->get();
+		return $this->withSharedLock($target, function () use ($target, $manifestPath, $mode, $service): IUser {
+			$repo = $this->targets->repository($target);
+			// Only ever read a manifest the verified catalog actually recorded: a path alone
+			// (even one this app generated before) proves nothing about it still being current
+			// or genuine once the catalog's rollback protection is supposed to vouch for it.
+			if (!$repo->isRecordedUserExport($manifestPath)) {
+				throw new \InvalidArgumentException("$manifestPath is not a recorded user export for this location");
+			}
+			$source = new RepositoryImportSource($repo, $manifestPath);
+			$originalUid = $source->getOriginalUid();
+
+			if ($mode === self::MODE_AS_BACKUP) {
+				$backupUid = $this->freeBackupUid($originalUid);
+				$user = $this->userManager->createUser($backupUid, $this->random->generate(32));
+				if ($user === false) {
+					throw new \RuntimeException("Could not create the account $backupUid");
+				}
+				try {
+					return $service->import($source, $user);
+				} catch (\Throwable $e) {
+					// A partially-imported, never-used account left behind is strictly worse
+					// than no account at all; the original source account was never touched.
+					$user->delete();
+					throw $e;
+				}
+			}
+
+			if ($mode !== self::MODE_REPLACE) {
+				throw new \InvalidArgumentException("Unknown restore mode: $mode");
+			}
+			$existing = $this->userManager->get($originalUid);
+			$safetyManifestPath = null;
+			if ($existing !== null) {
+				// Never import over a live account: export its current state first, so nothing
+				// is lost if the restore turns out to be the wrong choice.
+				$safety = new RepositoryExportDestination($repo, $originalUid);
+				$service->export($safety, $existing);
+				$safetyManifestPath = $safety->manifestPath();
+				// Same race as UserBackupService::backupUser(): serialize the catalog write
+				// itself against any other concurrent backup/restore for this target.
+				$this->withCatalogLock($target, fn () => $repo->recordUserExport($safetyManifestPath));
+				if (!$existing->delete()) {
+					throw new \RuntimeException("Could not delete the existing account $originalUid before restoring; its safety export is at $safetyManifestPath");
+				}
+				// IRootFolder caches a Folder per uid for the lifetime of this process; without
+				// this it would still hand the just-deleted account's (now storage-less) folder
+				// to the import below, and every write would fail.
+				$this->events->dispatchTyped(new FilesystemTornDownEvent());
+			}
+			try {
+				return $service->import($source, null);
+			} catch (\Throwable $e) {
+				// The original account is already gone at this point (or never existed); a
+				// failure here can only be reported, not undone in place. Its safety export
+				// (if any) is the recovery path, already recorded above.
+				throw new UserMigrationException(
+					"Could not restore $originalUid" . ($safetyManifestPath !== null ? "; its safety export is at $safetyManifestPath" : '') . ': ' . $e->getMessage(),
+					0,
+					$e,
+				);
+			}
+		});
+	}
+
+	private function freeBackupUid(string $uid): string {
+		$candidate = $uid . '-bak';
+		for ($n = 2; $this->userManager->userExists($candidate); $n++) {
+			$candidate = $uid . '-bak-' . $n;
+		}
+		return $candidate;
+	}
+
+	private function withSharedLock(Target $target, callable $fn): mixed {
+		try {
+			// See UserBackupService::withSharedLock(): UserMigrationService exposes no progress,
+			// so this lease cannot be refreshed mid-call.
+			return $this->leases->with(PruneService::lockKey($target), LeaseService::SHARED, 3600, $fn);
+		} catch (LockedException) {
+			throw new \RuntimeException('A cleanup of ' . $target->getName() . ' is in progress; try again later');
+		}
+	}
+
+	private function withCatalogLock(Target $target, callable $fn): mixed {
+		try {
+			return $this->leases->with(PruneService::catalogLockKey($target), LeaseService::EXCLUSIVE, 30, $fn);
+		} catch (LockedException) {
+			throw new \RuntimeException('Another catalog write for ' . $target->getName() . ' is in progress; try again');
+		}
+	}
+}

lib/Service/VerifyService.php

@@ -0,0 +1,48 @@
+<?php
+
+declare(strict_types=1);
+
+// SPDX-FileCopyrightText: 2026 Dillard Blom
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+namespace OCA\NgBackup\Service;
+
+use OCA\NgBackup\Db\Target;
+use OCP\Lock\LockedException;
+
+/** Checksum audit of a snapshot (occ backup:verify), see Repository::verify(). */
+final class VerifyService {
+	public function __construct(
+		private TargetService $targets,
+		private LeaseService $leases,
+	) {
+	}
+
+	/** @return array{filesChecked:int, blobsChecked:int, bytesChecked:int, missing:list<string>, failed:list<string>} */
+	public function verify(Target $target, string $snapshotId, bool $deep = false): array {
+		return $this->run($target, $deep, fn (\OCA\NgBackup\Repository\Repository $repo, callable $heartbeat): array => $repo->verify($snapshotId, $deep, $heartbeat));
+	}
+
+	/** @return array{filesChecked:int, blobsChecked:int, bytesChecked:int, missing:list<string>, failed:list<string>} */
+	public function verifyUserExport(Target $target, string $manifestPath, bool $deep = false): array {
+		return $this->run($target, $deep, fn (\OCA\NgBackup\Repository\Repository $repo, callable $heartbeat): array => $repo->verifyUserExport($manifestPath, $deep, $heartbeat));
+	}
+
+	private function run(Target $target, bool $deep, callable $fn): array {
+		$ttl = $deep ? 600 : 300;
+		try {
+			return $this->leases->with(PruneService::lockKey($target), LeaseService::SHARED, $ttl, function (callable $refresh) use ($target, $deep, $ttl, $fn): array {
+				$last = time();
+				$heartbeat = function () use ($refresh, $ttl, &$last): void {
+					if (time() - $last >= intdiv($ttl, 2)) {
+						$refresh();
+						$last = time();
+					}
+				};
+				return $fn($this->targets->repository($target), $heartbeat);
+			});
+		} catch (LockedException) {
+			throw new \RuntimeException('A cleanup of ' . $target->getName() . ' is in progress; try again later');
+		}
+	}
+}

lib/UserMigration/RepositoryExportDestination.php

@@ -65,11 +65,14 @@ final class RepositoryExportDestination implements IExportDestination {
 				if ($stream === false) {
 					throw new \RuntimeException('Cannot read ' . $node->getPath());
 				}
+				try {
 					$this->addFileAsStream($target, $stream);
+				} finally {
 					fclose($stream);
 				}
 			}
 		}
+	}
 
 	public function setMigratorVersions(array $versions): void {
 		$this->versions = $versions;

lib/UserMigration/RepositoryImportSource.php

@@ -109,11 +109,18 @@ final class RepositoryImportSource implements IImportSource {
 						$destination->newFile($name, $stream);
 					}
 				} finally {
+					// putContent()/newFile() already close the stream once they've consumed it:
+					// despite the @return resource docblock above, $stream is no longer a
+					// resource by the time we get here (verified against a real storage; a
+					// double fclose() throws a TypeError on PHP 8).
+					/** @psalm-suppress RedundantConditionGivenDocblockType */
+					if (is_resource($stream)) {
 						fclose($stream);
 					}
 				}
 			}
 		}
+	}
 
 	public function getMigratorVersions(): array {
 		return $this->manifest['versions'];

lib/UserMigration/UserMigrationServiceLocator.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+// SPDX-FileCopyrightText: 2026 Dillard Blom
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+namespace OCA\NgBackup\UserMigration;
+
+use OCP\App\IAppManager;
+use OCP\Server;
+use OCP\UserMigration\UserMigrationException;
+
+/**
+ * Resolves user_migration's own (internal, non-public) UserMigrationService on demand.
+ *
+ * Unlike files_external, user_migration is an optional dependency: without it, only per-user
+ * backup/restore is unavailable, the full backup still works. The class is never autoloaded by
+ * composer; everything that touches it is behind this one class.
+ */
+final class UserMigrationServiceLocator {
+	public function __construct(
+		private IAppManager $appManager,
+	) {
+	}
+
+	/** @throws UserMigrationException when user_migration is not enabled anywhere */
+	public function get(): object {
+		if (!$this->appManager->isEnabledForAnyone('user_migration')) {
+			throw new UserMigrationException('The user_migration app is not enabled; per-user backup/restore is unavailable');
+		}
+		$this->appManager->loadApp('user_migration');
+		return Server::get(\OCA\UserMigration\Service\UserMigrationService::class);
+	}
+}

psalm-baseline.xml

@@ -49,6 +49,11 @@
       <code><![CDATA[ask]]></code>
     </UndefinedInterfaceMethod>
   </file>
+  <file src="lib/Command/KeyImport.php">
+    <UndefinedInterfaceMethod>
+      <code><![CDATA[ask]]></code>
+    </UndefinedInterfaceMethod>
+  </file>
   <file src="lib/Command/KeyInit.php">
     <UndefinedInterfaceMethod>
       <code><![CDATA[ask]]></code>
@@ -455,6 +460,17 @@
       <code><![CDATA[array{kept: array<string, list<string>>, forgotten: list<string>, purged: list<string>, prune: array}]]></code>
     </MoreSpecificReturnType>
   </file>
+  <file src="lib/Service/RestoreFullService.php">
+    <EmptyArrayAccess>
+      <code><![CDATA[$backupConfig[$key]]]></code>
+    </EmptyArrayAccess>
+    <UndefinedInterfaceMethod>
+      <code><![CDATA[getInner]]></code>
+    </UndefinedInterfaceMethod>
+    <UnresolvableInclude>
+      <code><![CDATA[include $path]]></code>
+    </UnresolvableInclude>
+  </file>
   <file src="lib/Service/RestoreService.php">
     <LessSpecificReturnStatement>
       <code><![CDATA[array_values($children)]]></code>

psalm.xml

@@ -31,8 +31,17 @@
             <errorLevel type="suppress">
                 <!-- Provided by files_external at runtime; not a composer dependency (PLAN.md 3.5). -->
                 <referencedClass name="OCA\Files_External\**" />
+                <!-- Provided by user_migration at runtime, an optional dependency (PLAN.md 3.8). -->
+                <referencedClass name="OCA\UserMigration\**" />
             </errorLevel>
         </UndefinedClass>
+        <UndefinedDocblockClass>
+            <errorLevel type="suppress">
+                <!-- Server::get()'s templated return type resolving the users_migration class-string
+                     constant below; same reason as the UndefinedClass suppression above. -->
+                <referencedClass name="OCA\UserMigration\**" />
+            </errorLevel>
+        </UndefinedDocblockClass>
         <!-- The #[\Override] attribute convention (PHP 8.3+) adds no behaviour; this app supports
              PHP 8.1+, and applying it to every interface-implementing method project-wide is pure
              ceremony with no bug-catching value, so it's suppressed rather than papered over. -->

tests/Unit/Repository/UserExportTest.php

@@ -0,0 +1,109 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OCA\NgBackup\Tests\Unit\Repository;
+
+use OCA\NgBackup\Backend\LocalBackend;
+use OCA\NgBackup\Crypto\KeyRing;
+use OCA\NgBackup\Repository\ICatalogAnchor;
+use OCA\NgBackup\Repository\Repository;
+use OCA\NgBackup\Repository\RepositoryException;
+use OCA\NgBackup\Tests\Unit\TempDirTrait;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Repository::recordUserExport/listUserExports/forgetUserExport: the catalog side of a
+ * user_migration export (see RepositoryExportDestination/RepositoryImportSource, which this
+ * does not exercise directly since they implement OCP\UserMigration interfaces not available to
+ * plain PHPUnit; that round trip is covered by tests/integration/user-roundtrip.sh instead).
+ */
+class UserExportTest extends TestCase {
+	use TempDirTrait;
+
+	private LocalBackend $backend;
+	private KeyRing $keys;
+	private ICatalogAnchor $anchor;
+	private string $root;
+
+	protected function setUp(): void {
+		$this->root = $this->tempDir();
+		$this->backend = new LocalBackend($this->root);
+		$this->keys = KeyRing::generate();
+		$this->anchor = new class implements ICatalogAnchor {
+			public array $data = [];
+			public function get(string $r): ?array { return $this->data[$r] ?? null; }
+			public function set(string $r, int $g, string $h): void { $this->data[$r] = ['gen' => $g, 'hash' => $h]; }
+		};
+	}
+
+	private function open(): Repository {
+		return Repository::openWithKey($this->backend, $this->keys, null, $this->anchor);
+	}
+
+	/** Stands in for an export destination's close(): a manifest object plus a catalog record. */
+	private function putManifest(Repository $repo, string $path): void {
+		$repo->putObject($path, json_encode(['uid' => 'alice']));
+		$repo->recordUserExport($path);
+	}
+
+	public function testRecordAndListSurviveAReopen(): void {
+		$repo = Repository::initWithKey($this->backend, $this->keys, $this->keys->wrap('pw'), $this->anchor);
+		$this->putManifest($repo, 'users/alice/20261005T120000Z-aaaa0001');
+
+		$again = $this->open();
+		$this->assertSame(['users/alice/20261005T120000Z-aaaa0001'], $again->listUserExports());
+		$this->assertSame(['users/alice/20261005T120000Z-aaaa0001'], $again->listUserExports('alice'));
+		$this->assertSame([], $again->listUserExports('bob'));
+	}
+
+	public function testListIsNewestFirst(): void {
+		$repo = Repository::initWithKey($this->backend, $this->keys, $this->keys->wrap('pw'), $this->anchor);
+		$this->putManifest($repo, 'users/alice/20261005T120000Z-aaaa0001');
+		$this->putManifest($repo, 'users/alice/20261006T120000Z-aaaa0002');
+
+		$this->assertSame(
+			['users/alice/20261006T120000Z-aaaa0002', 'users/alice/20261005T120000Z-aaaa0001'],
+			$repo->listUserExports('alice'),
+		);
+	}
+
+	public function testForgetRemovesItFromTheCatalogAndLocation(): void {
+		$repo = Repository::initWithKey($this->backend, $this->keys, $this->keys->wrap('pw'), $this->anchor);
+		$path = 'users/alice/20261005T120000Z-aaaa0001';
+		$this->putManifest($repo, $path);
+
+		$repo->forgetUserExport($path);
+
+		$this->assertSame([], $repo->listUserExports());
+		$this->assertFalse($this->backend->exists($path));
+	}
+
+	public function testForgetRejectsAPathNotInTheCatalog(): void {
+		$repo = Repository::initWithKey($this->backend, $this->keys, $this->keys->wrap('pw'), $this->anchor);
+		$this->expectException(RepositoryException::class);
+		$repo->forgetUserExport('users/nobody/not-a-real-export');
+	}
+
+	public function testIsRecordedUserExport(): void {
+		$repo = Repository::initWithKey($this->backend, $this->keys, $this->keys->wrap('pw'), $this->anchor);
+		$path = 'users/alice/20261005T120000Z-aaaa0001';
+		$this->putManifest($repo, $path);
+
+		$this->assertTrue($repo->isRecordedUserExport($path));
+		$this->assertFalse($repo->isRecordedUserExport('users/alice/not-the-real-one'));
+	}
+
+	public function testListingDetectsAManifestRemovedBehindItsBack(): void {
+		// A catalog-listed export whose object disappeared from the location (deleted or
+		// hidden outside NG Backup) must be detected, the same as a missing snapshot.
+		$repo = Repository::initWithKey($this->backend, $this->keys, $this->keys->wrap('pw'), $this->anchor);
+		$path = 'users/alice/20261005T120000Z-aaaa0001';
+		$this->putManifest($repo, $path);
+		$this->backend->delete($path);
+
+		$this->expectException(RepositoryException::class);
+		$this->expectExceptionMessage('missing on the location');
+		$repo->listUserExports();
+	}
+}

tests/Unit/Repository/VerifyTest.php

@@ -0,0 +1,95 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OCA\NgBackup\Tests\Unit\Repository;
+
+use OCA\NgBackup\Backend\LocalBackend;
+use OCA\NgBackup\Crypto\KeyRing;
+use OCA\NgBackup\Repository\Repository;
+use OCA\NgBackup\Tests\Unit\TempDirTrait;
+use PHPUnit\Framework\TestCase;
+
+class VerifyTest extends TestCase {
+	use TempDirTrait;
+
+	private LocalBackend $backend;
+	private KeyRing $keys;
+	private string $root;
+	private string $src;
+
+	protected function setUp(): void {
+		$this->root = $this->tempDir();
+		$this->backend = new LocalBackend($this->root);
+		$this->keys = KeyRing::generate();
+		$this->src = $this->tempDir();
+		file_put_contents("$this->src/a", random_bytes(100000));
+		file_put_contents("$this->src/b", random_bytes(100000));
+	}
+
+	private function open(): Repository {
+		return Repository::openWithKey($this->backend, $this->keys, null, null);
+	}
+
+	public function testShallowVerifyPassesOnAHealthyRepository(): void {
+		$repo = Repository::initWithKey($this->backend, $this->keys, $this->keys->wrap('pw'));
+		$s = $repo->backupDirectory($this->src);
+
+		$result = $this->open()->verify($s['snapshot']);
+
+		$this->assertSame(2, $result['filesChecked']);
+		$this->assertGreaterThanOrEqual(1, $result['blobsChecked']);
+		$this->assertSame(0, $result['bytesChecked']); // not downloaded without --deep
+		$this->assertSame([], $result['missing']);
+		$this->assertSame([], $result['failed']);
+	}
+
+	public function testDeepVerifyDownloadsAndCountsBytes(): void {
+		$repo = Repository::initWithKey($this->backend, $this->keys, $this->keys->wrap('pw'));
+		$s = $repo->backupDirectory($this->src);
+
+		$result = $this->open()->verify($s['snapshot'], deep: true);
+
+		$this->assertSame(200000, $result['bytesChecked']);
+		$this->assertSame([], $result['missing']);
+		$this->assertSame([], $result['failed']);
+	}
+
+	public function testShallowVerifyDetectsAMissingPack(): void {
+		$repo = Repository::initWithKey($this->backend, $this->keys, $this->keys->wrap('pw'));
+		$s = $repo->backupDirectory($this->src);
+		foreach ($this->backend->list('packs') as $pack) {
+			$this->backend->delete($pack);
+		}
+
+		$result = $this->open()->verify($s['snapshot']);
+
+		$this->assertNotSame([], $result['missing']);
+	}
+
+	public function testVerifyFailsOnAMissingDatabaseManifest(): void {
+		$repo = Repository::initWithKey($this->backend, $this->keys, $this->keys->wrap('pw'));
+		$repo->writeSnapshot('snap-no-db', ['time' => gmdate('c'), 'db' => 'db/does-not-exist'], []);
+
+		$result = $this->open()->verify('snap-no-db');
+
+		$this->assertSame(['db/does-not-exist'], $result['missing']);
+	}
+
+	public function testDeepVerifyDetectsATamperedPack(): void {
+		$repo = Repository::initWithKey($this->backend, $this->keys, $this->keys->wrap('pw'));
+		$s = $repo->backupDirectory($this->src);
+		$packs = $this->backend->list('packs');
+		$this->assertNotEmpty($packs);
+		$path = $this->root . '/' . $packs[0];
+		$bytes = file_get_contents($path);
+		// Flip a byte well inside the file, away from any header, so decryption's own
+		// authentication tag catches it (this must fail loudly, not just "do nothing").
+		$bytes[(int)(strlen($bytes) / 2)] = chr(~ord($bytes[(int)(strlen($bytes) / 2)]) & 0xFF);
+		file_put_contents($path, $bytes);
+
+		$result = $this->open()->verify($s['snapshot'], deep: true);
+
+		$this->assertNotSame([], $result['failed']);
+	}
+}

tests/integration/full-restore-roundtrip.sh

@@ -0,0 +1,86 @@
+#!/bin/bash
+# Disaster recovery: occ backup:key:import + backup:target:add + backup:restore:full on a
+# SECOND, fresh Nextcloud instance that never saw the first one, sharing only the backup
+# location (a local directory, bind-mounted into both containers) -- see PLAN.md 3.7.
+# Usage: full-restore-roundtrip.sh <nextcloud-image-tag>
+#   e.g. full-restore-roundtrip.sh 35-apache
+set -euo pipefail
+IMAGE="nextcloud:${1:-35-apache}"
+APP=$(cd "$(dirname "$0")/../.." && pwd)
+NET=ngb-frt-net
+SHARED=$(mktemp -d)
+chmod 777 "$SHARED"
+fail() { echo "FAIL: $*"; exit 1; }
+ok() { echo "ok   $*"; }
+
+cleanup() {
+	docker rm -fv ngb-frt-origin ngb-frt-restore >/dev/null 2>&1 || true
+	docker network rm "$NET" >/dev/null 2>&1 || true
+	docker run --rm -v "$SHARED:/target" alpine sh -c 'rm -rf /target/*' >/dev/null 2>&1 || true
+	rmdir "$SHARED" 2>/dev/null || true
+	rm -f /tmp/ngb-frt-kit.json /tmp/ngb-frt-pass
+}
+trap cleanup EXIT
+
+run_on() { docker exec -u www-data "$1" php occ "${@:2}"; }
+
+docker network create "$NET" >/dev/null
+docker run -d --name ngb-frt-origin --network "$NET" -e SQLITE_DATABASE=nextcloud \
+	-e NEXTCLOUD_ADMIN_USER=admin -e NEXTCLOUD_ADMIN_PASSWORD=admin \
+	-v "$APP:/var/www/html/custom_apps/ng_backup:ro" -v "$SHARED:/mnt/shared" "$IMAGE" >/dev/null
+for i in $(seq 1 90); do run_on ngb-frt-origin status 2>/dev/null | grep -q "installed: true" && break; sleep 3; done
+docker exec ngb-frt-origin chown www-data:www-data /var/www/html/custom_apps
+run_on ngb-frt-origin app:enable ng_backup >/dev/null
+ok "origin instance up"
+
+docker exec ngb-frt-origin sh -c "printf 'full restore roundtrip passphrase 2026\n' > /tmp/pass"
+run_on ngb-frt-origin backup:key:init --passphrase-file=/tmp/pass --label=CI >/dev/null || fail "key init"
+run_on ngb-frt-origin backup:key:kit --output=/tmp/kit.json >/dev/null
+CODE=$(run_on ngb-frt-origin backup:key:kit | php -r 'echo json_decode(stream_get_contents(STDIN), true)["confirmation_code"];')
+run_on ngb-frt-origin backup:key:confirm -u admin --code="$CODE" --confirm="Yes, I confirm" >/dev/null || fail "confirm"
+run_on ngb-frt-origin backup:target:add offsite local -a null::null -o datadir=/mnt/shared --path=repo >/dev/null || fail "target add"
+ok "key, kit and location on the origin"
+
+NC_PASS=$(openssl rand -hex 16)
+docker exec -u www-data -e OC_PASS="$NC_PASS" ngb-frt-origin php occ user:add --password-from-env frtest >/dev/null
+docker exec ngb-frt-origin sh -c "mkdir -p /var/www/html/data/frtest/files/Docs && head -c 200000 /dev/urandom > /var/www/html/data/frtest/files/Docs/report.bin && echo 'hello disaster recovery' > /var/www/html/data/frtest/files/Docs/note.txt && chown -R www-data:www-data /var/www/html/data/frtest"
+run_on ngb-frt-origin files:scan frtest >/dev/null
+RUN_OUT=$(run_on ngb-frt-origin backup:run offsite -l disaster-test)
+SNAP=$(printf '%s\n' "$RUN_OUT" | head -1 | awk -F'snapshot ' '{print $2}' | tr -d ',')
+[ -n "$SNAP" ] || fail "no snapshot id from backup:run"
+ok "test data backed up, snapshot $SNAP"
+
+docker cp ngb-frt-origin:/tmp/kit.json /tmp/ngb-frt-kit.json
+docker exec ngb-frt-origin sh -c "cat /tmp/pass" > /tmp/ngb-frt-pass
+docker run -d --name ngb-frt-restore --network "$NET" -e SQLITE_DATABASE=nextcloud \
+	-e NEXTCLOUD_ADMIN_USER=admin -e NEXTCLOUD_ADMIN_PASSWORD=admin \
+	-v "$APP:/var/www/html/custom_apps/ng_backup:ro" -v "$SHARED:/mnt/shared" "$IMAGE" >/dev/null
+for i in $(seq 1 90); do run_on ngb-frt-restore status 2>/dev/null | grep -q "installed: true" && break; sleep 3; done
+docker exec ngb-frt-restore chown www-data:www-data /var/www/html/custom_apps
+run_on ngb-frt-restore app:enable ng_backup >/dev/null
+docker cp /tmp/ngb-frt-kit.json ngb-frt-restore:/tmp/kit.json
+docker exec ngb-frt-restore chmod 644 /tmp/kit.json
+docker cp /tmp/ngb-frt-pass ngb-frt-restore:/tmp/pass
+ok "fresh restore instance up"
+
+run_on ngb-frt-restore backup:key:import /tmp/kit.json --passphrase-file=/tmp/pass >/dev/null || fail "key import"
+run_on ngb-frt-restore backup:target:add offsite local -a null::null -o datadir=/mnt/shared --path=repo >/dev/null || fail "target add on the restore instance"
+run_on ngb-frt-restore backup:list offsite | grep -q "$SNAP" || fail "the origin's snapshot is not listed after connecting the location"
+ok "recovery kit imported, existing repository adopted, snapshot visible"
+
+run_on ngb-frt-restore backup:restore:full offsite "$SNAP" >/dev/null || fail "restore:full"
+ok "backup:restore:full completed"
+
+# Everything below must work in a FRESH occ process (a new PHP process per docker exec), since
+# earlier bugs here only showed up after config.php's secret was rewritten mid-restore.
+run_on ngb-frt-restore backup:status >/dev/null || fail "backup:status fails after restore (own key/target undecryptable?)"
+run_on ngb-frt-restore user:list | grep -q frtest || fail "the backed-up user is missing from the restored database"
+docker exec ngb-frt-restore test -f /var/www/html/data/frtest/files/Docs/note.txt || fail "restored file is missing"
+[ "$(docker exec ngb-frt-restore cat /var/www/html/data/frtest/files/Docs/note.txt)" = "hello disaster recovery" ] || fail "restored file content differs"
+run_on ngb-frt-restore files:scan frtest >/dev/null || fail "files:scan fails after restore"
+ok "database, files and ng_backup's own state are all intact and usable after the restore"
+
+run_on ngb-frt-restore backup:run offsite -l post-restore-check >/dev/null || fail "a new backup after the restore fails"
+ok "the restored instance can run a new backup of its own"
+
+echo "FULL RESTORE ROUNDTRIP PASS"

tests/integration/roundtrip.sh

@@ -49,6 +49,11 @@ SUM_AFTER=$($X sh -c "cd $DATA/$U/files && find . -type f -print0 | sort -z | xa
 $X sh -c "ls $DATA/$U/files_trashbin/files/ | grep -q '^extra.txt'" || fail "extra file not in trash"
 ok "restore new-folder and replace: files identical, extra file in the trash"
 
+# Checksum audit: shallow (index presence) and deep (download, decrypt, verify every blob).
+occ backup:verify ci "$SNAP" | grep -q "^OK$" || fail "shallow verify"
+occ backup:verify ci "$SNAP" --deep | grep -q "^OK$" || fail "deep verify"
+ok "shallow and deep checksum audit"
+
 # Database dump/restore round trip (all tables, checksums, sequences on PostgreSQL).
 $X php -d memory_limit=512M "$APPS/ng_backup/spikes/03-db-dump.php" /tmp/ngb-rt-db | grep "ALL PASS" >/dev/null || fail "database round trip"
 ok "database dump and restore"

tests/integration/targets-matrix.sh

@@ -1,17 +1,25 @@
 #!/bin/bash
-# Round trip of NG Backup against real S3 (s3mock) and SFTP backends, through files_external's own
+# Round trip of NG Backup against real S3 (s3mock), SFTP, FTP and SMB backends, through
-# backend/auth classes, same as a production location would use. Backend correctness does not
+# files_external's own backend/auth classes, same as a production location would use. Backend
-# depend on the Nextcloud version or database, so this runs once (not matrixed across NC/DB),
+# correctness does not depend on the Nextcloud version or database, so this runs once (not
-# on a recent Nextcloud with sqlite. Each backend gets its own fresh Nextcloud container, since
+# matrixed across NC/DB), on a recent Nextcloud with sqlite. Each backend gets its own fresh
-# NG Backup's key can only be initialised once per instance.
+# Nextcloud container, since NG Backup's key can only be initialised once per instance.
 # Usage: tests/integration/targets-matrix.sh [nextcloud-version]
 set -euo pipefail
 V=${1:-35}
 APP=$(cd "$(dirname "$0")/../.." && pwd)
 NET=ngb-targets-net
+SMB_IMAGE=ngb-targets-smb-nc
+SMB_BUILD_DIR=$(mktemp -d)
 RESULTS=()
 
-cleanup() { docker rm -fv ngb-targets-nc-s3 ngb-targets-nc-sftp ngb-targets-s3 ngb-targets-sftp >/dev/null 2>&1; docker network rm "$NET" >/dev/null 2>&1; }
+cleanup() {
+  docker rm -fv ngb-targets-nc-s3 ngb-targets-nc-sftp ngb-targets-nc-ftp ngb-targets-nc-smb \
+    ngb-targets-s3 ngb-targets-sftp ngb-targets-ftp ngb-targets-smb >/dev/null 2>&1 || true
+  docker rmi "$SMB_IMAGE" >/dev/null 2>&1 || true
+  docker network rm "$NET" >/dev/null 2>&1 || true
+  rm -rf "$SMB_BUILD_DIR"
+}
 trap cleanup EXIT
 
 wait_tcp() { # host port
@@ -19,11 +27,11 @@ wait_tcp() { # host port
     || { echo "FAIL: $1:$2 never came up"; exit 1; }
 }
 
-start_nc() { # container-name
+start_nc() { # container-name [image]
   docker run -d --name "$1" --network "$NET" \
     -e NEXTCLOUD_ADMIN_USER=admin -e NEXTCLOUD_ADMIN_PASSWORD=admin-targets-pw -e NEXTCLOUD_TRUSTED_DOMAINS=localhost \
     -e SQLITE_DATABASE=nextcloud \
-    -v "$APP:/var/www/html/custom_apps/ng_backup:ro" nextcloud:$V-apache >/dev/null
+    -v "$APP:/var/www/html/custom_apps/ng_backup:ro" "${2:-nextcloud:$V-apache}" >/dev/null
   for i in $(seq 1 90); do docker exec -u www-data "$1" php occ status 2>/dev/null | grep -q "installed: true" && break; sleep 4; done
   docker exec "$1" chown www-data:www-data /var/www/html/custom_apps
   echo "=== NC $V / sqlite ($1): $(docker exec -u www-data "$1" php occ -V 2>/dev/null)"
@@ -51,8 +59,37 @@ docker run -d --name ngb-targets-s3 --network "$NET" \
 docker run -d --name ngb-targets-sftp --network "$NET" \
   atmoz/sftp ngbackup:ngbackuppw:::upload >/dev/null
 
+# stilliard/pure-ftpd: delfer/alpine-ftp-server (vsftpd) was tried first and rejects the absolute
+# paths files_external's FTP backend always builds, inside this server's chroot specifically --
+# not a files_external bug (confirmed with plain php ftp_mkdir()), but pure-ftpd sidesteps it.
+docker run -d --name ngb-targets-ftp --network "$NET" \
+  -e "FTP_USER_NAME=ngbackup" -e "FTP_USER_PASS=ngbackuppw" -e "FTP_USER_HOME=/home/ngbackup" \
+  -e "PUBLICHOST=ngb-targets-ftp" \
+  stilliard/pure-ftpd >/dev/null
+
+# dperson/samba. The *native* smbclient PECL extension is required: files_external's shell-based
+# fallback (just the smbclient CLI binary) still registers this backend, but its stream cannot
+# seek, and ng_backup reads blobs back by byte range while backing up -- confirmed live, that
+# fallback fails the very first (small) backup with "Seek failed in packs/...". The extension is
+# not in the stock nextcloud image (needs libsmbclient-dev + a compile), so this backend gets its
+# own small image, built once here, in its own directory (never /tmp directly: that would send
+# every unrelated file under /tmp to the docker daemon as build context).
+cat > "$SMB_BUILD_DIR/Dockerfile" <<EOF
+FROM nextcloud:$V-apache
+RUN apt-get update -qq && apt-get install -y -qq libsmbclient-dev >/dev/null \\
+  && pecl install smbclient >/dev/null 2>&1 \\
+  && docker-php-ext-enable smbclient \\
+  && apt-get clean
+EOF
+docker build -q -t "$SMB_IMAGE" "$SMB_BUILD_DIR" >/dev/null
+docker run -d --name ngb-targets-smb --network "$NET" \
+  -e USERID=1000 -e GROUPID=1000 \
+  dperson/samba -p -u "ngbackup;ngbackuppw" -s "backup;/share;yes;no;no;ngbackup" >/dev/null
+
 wait_tcp ngb-targets-s3 9090
 wait_tcp ngb-targets-sftp 22
+wait_tcp ngb-targets-ftp 21
+wait_tcp ngb-targets-smb 445
 
 start_nc ngb-targets-nc-s3
 run "S3 (s3mock)" ngb-targets-nc-s3 "amazons3 -a amazons3::accesskey -o bucket=ngbackups -o hostname=ngb-targets-s3 -o port=9090 -o region=us-east-1 -o use_ssl=false -o use_path_style=true -o key=test -o secret=test"
@@ -60,6 +97,12 @@ run "S3 (s3mock)" ngb-targets-nc-s3 "amazons3 -a amazons3::accesskey -o bucket=n
 start_nc ngb-targets-nc-sftp
 run "SFTP" ngb-targets-nc-sftp "sftp -a password::password -o host=ngb-targets-sftp -o root=/upload -o user=ngbackup -o password=ngbackuppw"
 
+start_nc ngb-targets-nc-ftp
+run "FTP" ngb-targets-nc-ftp "ftp -a password::password -o host=ngb-targets-ftp -o user=ngbackup -o password=ngbackuppw"
+
+start_nc ngb-targets-nc-smb "$SMB_IMAGE"
+run "SMB" ngb-targets-nc-smb "smb -a password::password -o host=ngb-targets-smb -o share=backup -o user=ngbackup -o password=ngbackuppw"
+
 printf '%s\n' "${RESULTS[@]}"
 printf '%s\n' "${RESULTS[@]}" | grep -q FAIL && exit 1
 exit 0

tests/integration/user-roundtrip.sh

@@ -0,0 +1,71 @@
+#!/bin/bash
+# Per-user backup/restore round trip via user_migration (optional dependency, see PLAN.md 3.8):
+# occ backup:user:backup / occ backup:user:restore --mode=as-backup|replace.
+# Usage: user-roundtrip.sh "<command prefix to run occ/php as the web user>" <datadir> [target-args]
+#   e.g. user-roundtrip.sh "docker exec -u www-data ngb-nc35-pgsql" /var/www/html/data
+set -euo pipefail
+X="$1"; DATA="$2"
+TARGET_ARGS="${3:-local -a null::null -o datadir=/tmp/ngb-urt-target}"
+occ() { $X php occ "$@"; }
+fail() { echo "FAIL: $*"; exit 1; }
+ok() { echo "ok   $*"; }
+U=ngbutest-$RANDOM
+
+occ app:enable ng_backup >/dev/null
+if ! occ app:install user_migration >/dev/null 2>&1 && ! occ app:enable user_migration >/dev/null 2>&1; then
+	echo "SKIP: user_migration is not available (no network, or the app store is unreachable) -- per-user backup/restore not tested"
+	exit 0
+fi
+sleep 8 # APCu app config cache
+
+$X sh -c "printf 'user roundtrip passphrase 2026\n' > /tmp/ngb-urt-pass && mkdir -p /tmp/ngb-urt-target"
+occ backup:key:init --passphrase-file=/tmp/ngb-urt-pass --label=CI --delete-delay-days=7 >/dev/null || fail "key init"
+CODE=$(occ backup:key:kit | php -r 'echo json_decode(stream_get_contents(STDIN), true)["confirmation_code"];')
+occ backup:key:confirm -u admin --code="$CODE" --confirm="Yes, I confirm" >/dev/null || fail "confirm"
+ok "key, kit code and confirmation"
+
+occ backup:target:add ci $TARGET_ARGS --path=repo >/dev/null || fail "target add"
+ok "location added"
+
+$X sh -c "OC_PASS='User-roundtrip-pw-2026' php occ user:add --password-from-env $U >/dev/null"
+$X sh -c "mkdir -p $DATA/$U/files/Docs && for i in 1 2 3; do head -c 100000 /dev/urandom > $DATA/$U/files/Docs/f\$i.bin; done"
+occ files:scan "$U" >/dev/null
+SUM_BEFORE=$($X sh -c "cd $DATA/$U/files && find . -type f -print0 | sort -z | xargs -0 md5sum | md5sum")
+
+MANIFEST=$(occ backup:user:backup ci "$U" | sed -n 's/.* to \(.*\)\.$/\1/p')
+[ -n "$MANIFEST" ] || fail "backup:user:backup printed no manifest path"
+ok "backed up $U to $MANIFEST"
+
+# as-backup: restore into <uid>-bak; the original account must stay untouched.
+occ backup:user:restore ci "$MANIFEST" --mode=as-backup >/dev/null || fail "restore as-backup"
+occ files:scan "$U-bak" >/dev/null
+SUM_BAK=$($X sh -c "cd $DATA/$U-bak/files && find . -type f -print0 | sort -z | xargs -0 md5sum | md5sum")
+[ "$SUM_BEFORE" = "$SUM_BAK" ] || fail "the <uid>-bak account's files differ from the original"
+occ user:delete "$U-bak" >/dev/null
+$X sh -c "[ -d '$DATA/$U/files/Docs' ]" || fail "the original account should be untouched by an as-backup restore"
+ok "as-backup restores into <uid>-bak, byte-identical, original account untouched"
+
+# replace: damage the account, then restore it in place under the same uid.
+$X sh -c "rm '$DATA/$U/files/Docs/f1.bin' && echo damaged > '$DATA/$U/files/Docs/f1.bin'"
+occ files:scan "$U" >/dev/null
+occ backup:user:restore ci "$MANIFEST" --mode=replace >/dev/null || fail "restore replace"
+occ files:scan "$U" >/dev/null
+SUM_AFTER=$($X sh -c "cd $DATA/$U/files && find . -type f -print0 | sort -z | xargs -0 md5sum | md5sum")
+[ "$SUM_BEFORE" = "$SUM_AFTER" ] || fail "files differ after a replace restore"
+ok "replace restores the original content under the same uid, byte-identical"
+
+# Retention: $U now has the manual export above plus the automatic safety-export the replace
+# restore made of it just before deleting it (4 total after these two more), then --user-last=2
+# must forget exactly the 2 oldest.
+sleep 1.1 # exportId is time-based to the second; force each one to be distinct
+occ backup:user:backup ci "$U" >/dev/null || fail "third backup:user:backup"
+sleep 1.1
+occ backup:user:backup ci "$U" >/dev/null || fail "fourth backup:user:backup"
+occ backup:retention --user-last=2 >/dev/null || fail "retention --user-last"
+PRUNE_OUT=$(occ backup:prune ci)
+echo "$PRUNE_OUT" | grep -q "forgot 2 user export(s) for 1 user(s)" || fail "prune did not forget the expected two user exports"
+ok "user-export retention forgets exactly the exports over the keep count"
+
+occ user:delete "$U" >/dev/null
+$X sh -c "rm -rf /tmp/ngb-urt-target /tmp/ngb-urt-pass"
+echo "USER ROUNDTRIP PASS"