Add provisioning for aliases

Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>

10 files changed, 297 insertions, 69 deletions

diff --git a/lib/Controller/AliasesController.php b/lib/Controller/AliasesController.php
index 8c1b49ddc..add3efb5f 100644
--- a/lib/Controller/AliasesController.php
+++ b/lib/Controller/AliasesController.php
@@ -72,8 +72,8 @@ class AliasesController extends Controller {
 	 * @NoAdminRequired
 	 * @TrapError
 	 */
-	public function update() {
-		throw new NotImplemented();
+	public function update(int $id, string $alias, string $aliasName): JSONResponse {
+		return new JSONResponse($this->aliasService->update($this->currentUserId, $id, $alias, $aliasName));
 	}
 
 	/**
@@ -84,7 +84,7 @@ class AliasesController extends Controller {
 	 * @return JSONResponse
 	 */
 	public function destroy(int $id): JSONResponse {
-		return new JSONResponse($this->aliasService->delete($id, $this->currentUserId));
+		return new JSONResponse($this->aliasService->delete($this->currentUserId, $id));
 	}
 
 	/**
@@ -116,7 +116,6 @@ class AliasesController extends Controller {
 	 * @throws DoesNotExistException
 	 */
 	public function updateSignature(int $id, string $signature = null): JSONResponse {
-		$this->aliasService->updateSignature($this->currentUserId, $id, $signature);
-		return new JSONResponse();
+		return new JSONResponse($this->aliasService->updateSignature($this->currentUserId, $id, $signature));
 	}
 }
diff --git a/lib/Controller/SettingsController.php b/lib/Controller/SettingsController.php
index 2081ea5bb..dd1a19dc4 100644
--- a/lib/Controller/SettingsController.php
+++ b/lib/Controller/SettingsController.php
@@ -60,6 +60,8 @@ class SettingsController extends Controller {
 			$this->provisioningManager->newProvisioning($data);
 		} catch (ValidationException $e) {
 			return HttpJsonResponse::fail([$e->getFields()]);
+		} catch (\Exception $e) {
+			return HttpJsonResponse::fail([$e->getMessage()]);
 		}
 
 		return new JSONResponse([]);
@@ -67,12 +69,11 @@ class SettingsController extends Controller {
 
 	public function updateProvisioning(int $id, array $data): JSONResponse {
 		try {
-			$this->provisioningManager->updateProvisioning(array_merge(
-				$data,
-				['id' => $id]
-			));
+			$this->provisioningManager->updateProvisioning(array_merge($data, ['id' => $id]));
 		} catch (ValidationException $e) {
 			return HttpJsonResponse::fail([$e->getFields()]);
+		} catch (\Exception $e) {
+			return HttpJsonResponse::fail([$e->getMessage()]);
 		}
 
 		return new JSONResponse([]);
diff --git a/lib/Db/Alias.php b/lib/Db/Alias.php
index e1727a83c..812682678 100644
--- a/lib/Db/Alias.php
+++ b/lib/Db/Alias.php
@@ -24,7 +24,6 @@ declare(strict_types=1);
 namespace OCA\Mail\Db;
 
 use JsonSerializable;
-
 use OCP\AppFramework\Db\Entity;
 
 /**
@@ -36,6 +35,8 @@ use OCP\AppFramework\Db\Entity;
  * @method string getAlias()
  * @method void setSignature(string|null $signature)
  * @method string|null getSignature()
+ * @method void setProvisioningId(int $provisioningId)
+ * @method int|null getProvisioningId()
  */
 class Alias extends Entity implements JsonSerializable {
 
@@ -51,10 +52,18 @@ class Alias extends Entity implements JsonSerializable {
 	/** @var string|null */
 	protected $signature;
 
+	/** @var int|null */
+	protected $provisioningId;
+
 	public function __construct() {
 		$this->addType('accountId', 'int');
 		$this->addType('name', 'string');
 		$this->addType('alias', 'string');
+		$this->addType('provisioningId', 'int');
+	}
+
+	public function isProvisioned(): bool {
+		return $this->getProvisioningId() !== null;
 	}
 
 	public function jsonSerialize(): array {
@@ -63,6 +72,7 @@ class Alias extends Entity implements JsonSerializable {
 			'name' => $this->getName(),
 			'alias' => $this->getAlias(),
 			'signature' => $this->getSignature(),
+			'provisioned' => $this->isProvisioned(),
 		];
 	}
 }
diff --git a/lib/Db/AliasMapper.php b/lib/Db/AliasMapper.php
index bf2e17b5d..ad95fc5b6 100644
--- a/lib/Db/AliasMapper.php
+++ b/lib/Db/AliasMapper.php
@@ -41,7 +41,7 @@ class AliasMapper extends QBMapper {
 	 */
 	public function find(int $aliasId, string $currentUserId): Alias {
 		$qb = $this->db->getQueryBuilder();
-		$qb->select('aliases.*')
+		$qb->select('aliases.*', 'accounts.provisioning_id')
 			->from($this->getTableName(), 'aliases')
 			->join('aliases', 'mail_accounts', 'accounts', $qb->expr()->eq('aliases.account_id', 'accounts.id'))
 			->where(
@@ -55,6 +55,24 @@ class AliasMapper extends QBMapper {
 	}
 
 	/**
+	 * @throws DoesNotExistException
+	 */
+	public function findByAlias(string $alias, string $currentUserId): Alias {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('aliases.*', 'accounts.provisioning_id')
+			->from($this->getTableName(), 'aliases')
+			->join('aliases', 'mail_accounts', 'accounts', $qb->expr()->eq('aliases.account_id', 'accounts.id'))
+			->where(
+				$qb->expr()->andX(
+					$qb->expr()->eq('accounts.user_id', $qb->createNamedParameter($currentUserId)),
+					$qb->expr()->eq('aliases.alias', $qb->createNamedParameter($alias))
+				)
+			);
+
+		return $this->findEntity($qb);
+	}
+
+	/**
 	 * @param int $accountId
 	 * @param string $currentUserId
 	 *
@@ -62,7 +80,7 @@ class AliasMapper extends QBMapper {
 	 */
 	public function findAll(int $accountId, string $currentUserId): array {
 		$qb = $this->db->getQueryBuilder();
-		$qb->select('aliases.*')
+		$qb->select('aliases.*', 'accounts.provisioning_id')
 			->from($this->getTableName(), 'aliases')
 			->join('aliases', 'mail_accounts', 'accounts', $qb->expr()->eq('aliases.account_id', 'accounts.id'))
 			->where(
@@ -89,6 +107,29 @@ class AliasMapper extends QBMapper {
 		$query->execute();
 	}
 
+	/**
+	 * Delete all provisioned aliases for the given uid
+	 *
+	 * Exception for Nextcloud 20: \Doctrine\DBAL\DBALException
+	 * Exception for Nextcloud 21 and newer: \OCP\DB\Exception
+	 *
+	 * @TODO: Change throws to \OCP\DB\Exception once Mail does not support Nextcloud 20.
+	 *
+	 * @throws \Exception
+	 */
+	public function deleteProvisionedAliasesByUid(string $uid): void {
+		$qb = $this->db->getQueryBuilder();
+
+		$qb->delete($this->getTableName(), 'aliases')
+			->join('aliases', 'mail_accounts', 'accounts', 'accounts.id = aliases.account_id')
+			->where(
+				$qb->expr()->eq('accounts.user_id', $qb->createNamedParameter($uid)),
+				$qb->expr()->isNotNull('provisioning_id')
+			);
+
+		$qb->execute();
+	}
+
 	public function deleteOrphans(): void {
 		$qb1 = $this->db->getQueryBuilder();
 		$idsQuery = $qb1->select('a.id')
diff --git a/lib/Db/Provisioning.php b/lib/Db/Provisioning.php
index 97d3c7a81..b29afa91c 100644
--- a/lib/Db/Provisioning.php
+++ b/lib/Db/Provisioning.php
@@ -60,6 +60,12 @@ use OCP\IUser;
  * @method void setSieveSslMode(?string $sieveSslMode)
  * @method string|null getSieveUser()
  * @method void setSieveUser(?string $sieveUser)
+ * @method array getAliases()
+ * @method void setAliases(array $aliases)
+ * @method bool getLdapAliasesProvisioning()
+ * @method void setLdapAliasesProvisioning(bool $ldapAliasesProvisioning)
+ * @method string|null getLdapAliasesAttribute()
+ * @method void setLdapAliasesAttribute(?string $ldapAliasesAttribute)
  */
 class Provisioning extends Entity implements JsonSerializable {
 	public const WILDCARD = '*';
@@ -79,13 +85,18 @@ class Provisioning extends Entity implements JsonSerializable {
 	protected $sieveHost;
 	protected $sievePort;
 	protected $sieveSslMode;
+	protected $aliases = [];
+	protected $ldapAliasesProvisioning;
+	protected $ldapAliasesAttribute;
 
 	public function __construct() {
 		$this->addType('imapPort', 'integer');
 		$this->addType('smtpPort', 'integer');
 		$this->addType('sieveEnabled', 'boolean');
 		$this->addType('sievePort', 'integer');
+		$this->addType('ldapAliasesProvisioning', 'boolean');
 	}
+
 	/**
 	 * @return array
 	 */
@@ -107,6 +118,9 @@ class Provisioning extends Entity implements JsonSerializable {
 			'sieveHost' => $this->getSieveHost(),
 			'sievePort' => $this->getSievePort(),
 			'sieveSslMode' => $this->getSieveSslMode(),
+			'aliases' => $this->getAliases(),
+			'ldapAliasesProvisioning' => $this->getLdapAliasesProvisioning(),
+			'ldapAliasesAttribute' => $this->getLdapAliasesAttribute(),
 		];
 	}
 
diff --git a/lib/Db/ProvisioningMapper.php b/lib/Db/ProvisioningMapper.php
index 09eec6281..0daca261f 100644
--- a/lib/Db/ProvisioningMapper.php
+++ b/lib/Db/ProvisioningMapper.php
@@ -51,11 +51,11 @@ class ProvisioningMapper extends QBMapper {
 	 *
 	 * @return Provisioning[]
 	 */
-	public function getAll() : array {
+	public function getAll(): array {
 		$qb = $this->db->getQueryBuilder();
 		$qb = $qb->select('*')
-				->from($this->getTableName())
-				->orderBy('provisioning_domain', 'desc');
+			->from($this->getTableName())
+			->orderBy('provisioning_domain', 'desc');
 		try {
 			return $this->findEntities($qb);
 		} catch (DoesNotExistException $e) {
@@ -69,7 +69,7 @@ class ProvisioningMapper extends QBMapper {
 	 * @return Provisioning
 	 * @throws ValidationException
 	 */
-	public function validate(array $data) : Provisioning {
+	public function validate(array $data): Provisioning {
 		$exception = new ValidationException();
 
 		if (!isset($data['provisioningDomain']) || $data['provisioningDomain'] === '') {
@@ -103,11 +103,17 @@ class ProvisioningMapper extends QBMapper {
 			$exception->setField('smtpSslMode', false);
 		}
 
+		$ldapAliasesProvisioning = (bool)($data['ldapAliasesProvisioning'] ?? false);
+		$ldapAliasesAttribute = $data['ldapAliasesAttribute'] ?? '';
+
+		if ($ldapAliasesProvisioning && empty($ldapAliasesAttribute)) {
+			$exception->setField('ldapAliasesAttribute', false);
+		}
+
 		if (!empty($exception->getFields())) {
 			throw $exception;
 		}
 
-
 		$provisioning = new Provisioning();
 		$provisioning->setId($data['id'] ?? null);
 		$provisioning->setProvisioningDomain($data['provisioningDomain']);
@@ -127,14 +133,17 @@ class ProvisioningMapper extends QBMapper {
 		$provisioning->setSievePort($data['sievePort'] ?? null);
 		$provisioning->setSieveSslMode($data['sieveSslMode'] ?? '');
 
+		$provisioning->setLdapAliasesProvisioning($ldapAliasesProvisioning);
+		$provisioning->setLdapAliasesAttribute($ldapAliasesAttribute);
+
 		return $provisioning;
 	}
 
 	public function get(int $id): ?Provisioning {
 		$qb = $this->db->getQueryBuilder();
 		$qb = $qb->select('*')
-				->from($this->getTableName())
-				->where($qb->expr()->eq('id', $qb->createNamedParameter($id), IQueryBuilder::PARAM_INT));
+			->from($this->getTableName())
+			->where($qb->expr()->eq('id', $qb->createNamedParameter($id), IQueryBuilder::PARAM_INT));
 		try {
 			return $this->findEntity($qb);
 		} catch (DoesNotExistException $e) {
diff --git a/lib/Migration/Version1101Date20210616141806.php b/lib/Migration/Version1101Date20210616141806.php
new file mode 100644
index 000000000..0687b9091
--- /dev/null
+++ b/lib/Migration/Version1101Date20210616141806.php
@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OCA\Mail\Migration;
+
+use Closure;
+use Doctrine\DBAL\Schema\SchemaException;
+use OCP\DB\ISchemaWrapper;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+
+class Version1101Date20210616141806 extends SimpleMigrationStep {
+	/**
+	 * @throws SchemaException
+	 */
+	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+
+		$provisioningTable = $schema->getTable('mail_provisionings');
+		$provisioningTable->addColumn('ldap_aliases_provisioning', 'boolean', [
+			'notnull' => false,
+			'default' => false
+		]);
+		$provisioningTable->addColumn('ldap_aliases_attribute', 'string', [
+			'notnull' => false,
+			'length' => 255,
+			'default' => '',
+		]);
+
+		return $schema;
+	}
+}
diff --git a/lib/Service/AliasesService.php b/lib/Service/AliasesService.php
index db21e1388..7d308b97c 100644
--- a/lib/Service/AliasesService.php
+++ b/lib/Service/AliasesService.php
@@ -26,6 +26,7 @@ namespace OCA\Mail\Service;
 use OCA\Mail\Db\Alias;
 use OCA\Mail\Db\AliasMapper;
 use OCA\Mail\Db\MailAccountMapper;
+use OCA\Mail\Exception\ClientException;
 use OCP\AppFramework\Db\DoesNotExistException;
 
 class AliasesService {
@@ -81,15 +82,17 @@ class AliasesService {
 	}
 
 	/**
-	 * @param int $aliasId
-	 * @param String $currentUserId
-	 * @return Alias
+	 * @throws ClientException
 	 * @throws DoesNotExistException
 	 */
-	public function delete(int $aliasId, string $currentUserId): Alias {
-		$alias = $this->aliasMapper->find($aliasId, $currentUserId);
-		$this->aliasMapper->delete($alias);
-		return $alias;
+	public function delete(string $userId, int $aliasId): Alias {
+		$entity = $this->aliasMapper->find($aliasId, $userId);
+
+		if ($entity->isProvisioned()) {
+			throw new ClientException('Deleting a provisioned alias is not allowed.');
+		}
+
+		return $this->aliasMapper->delete($entity);
 	}
 
 	/**
@@ -105,16 +108,29 @@ class AliasesService {
 	}
 
 	/**
+	 * Update alias and name
+	 *
+	 * @throws DoesNotExistException
+	 */
+	public function update(string $userId, int $aliasId, string $alias, string $aliasName): Alias {
+		$entity = $this->aliasMapper->find($aliasId, $userId);
+
+		if (!$entity->isProvisioned()) {
+			$entity->setAlias($alias);
+		}
+		$entity->setName($aliasName);
+
+		return $this->aliasMapper->update($entity);
+	}
+
+	/**
 	 * Update signature for alias
 	 *
-	 * @param string $userId
-	 * @param int $aliasId
-	 * @param string|null $signature
 	 * @throws DoesNotExistException
 	 */
-	public function updateSignature(string $userId, int $aliasId, string $signature = null): void {
-		$alias = $this->find($aliasId, $userId);
-		$alias->setSignature($signature);
-		$this->aliasMapper->update($alias);
+	public function updateSignature(string $userId, int $aliasId, string $signature = null): Alias {
+		$entity = $this->find($aliasId, $userId);
+		$entity->setSignature($signature);
+		return $this->aliasMapper->update($entity);
 	}
 }
diff --git a/lib/Service/Provisioning/Manager.php b/lib/Service/Provisioning/Manager.php
index 8cc9c2e06..6f06c330e 100644
--- a/lib/Service/Provisioning/Manager.php
+++ b/lib/Service/Provisioning/Manager.php
@@ -24,6 +24,8 @@ declare(strict_types=1);
 namespace OCA\Mail\Service\Provisioning;
 
 use Horde_Mail_Rfc822_Address;
+use OCA\Mail\Db\Alias;
+use OCA\Mail\Db\AliasMapper;
 use OCA\Mail\Db\MailAccount;
 use OCA\Mail\Db\MailAccountMapper;
 use OCA\Mail\Db\Provisioning;
@@ -33,6 +35,8 @@ use OCP\AppFramework\Db\DoesNotExistException;
 use OCP\AppFramework\Db\MultipleObjectsReturnedException;
 use OCP\IUser;
 use OCP\IUserManager;
+use OCP\LDAP\ILDAPProvider;
+use OCP\LDAP\ILDAPProviderFactory;
 use OCP\Security\ICrypto;
 use Psr\Log\LoggerInterface;
 
@@ -50,6 +54,12 @@ class Manager {
 	/** @var ICrypto */
 	private $crypto;
 
+	/** @var ILDAPProviderFactory */
+	private $ldapProviderFactory;
+
+	/** @var AliasMapper */
+	private $aliasMapper;
+
 	/** @var LoggerInterface */
 	private $logger;
 
@@ -57,11 +67,15 @@ class Manager {
 								ProvisioningMapper $provisioningMapper,
 								MailAccountMapper $mailAccountMapper,
 								ICrypto $crypto,
+								ILDAPProviderFactory $ldapProviderFactory,
+								AliasMapper $aliasMapper,
 								LoggerInterface $logger) {
 		$this->userManager = $userManager;
 		$this->provisioningMapper = $provisioningMapper;
 		$this->mailAccountMapper = $mailAccountMapper;
 		$this->crypto = $crypto;
+		$this->ldapProviderFactory = $ldapProviderFactory;
+		$this->aliasMapper = $aliasMapper;
 		$this->logger = $logger;
 	}
 
@@ -85,6 +99,75 @@ class Manager {
 	}
 
 	/**
+	 * Delete orphaned aliases for the given account.
+	 *
+	 * A alias is orphaned if not listed in newAliases anymore
+	 * (=> the provisioning configuration does contain it anymore)
+	 *
+	 * Exception for Nextcloud 20: \Doctrine\DBAL\DBALException
+	 * Exception for Nextcloud 21 and newer: \OCP\DB\Exception
+	 *
+	 * @TODO: Change throws to \OCP\DB\Exception once Mail requires Nextcloud 21 or above
+	 *
+	 * @throws \Exception
+	 */
+	private function deleteOrphanedAliases(string $userId, int $accountId, array $newAliases): void {
+		$existingAliases = $this->aliasMapper->findAll($accountId, $userId);
+		foreach ($existingAliases as $existingAlias) {
+			if (!in_array($existingAlias->getAlias(), $newAliases, true)) {
+				$this->aliasMapper->delete($existingAlias);
+			}
+		}
+	}
+
+	/**
+	 * Create new aliases for the given account.
+	 *
+	 * Exception for Nextcloud 20: \Doctrine\DBAL\DBALException
+	 * Exception for Nextcloud 21 and newer: \OCP\DB\Exception
+	 *
+	 * @TODO: Change throws to \OCP\DB\Exception once Mail requires Nextcloud 21 or above
+	 *
+	 * @throws \Exception
+	 */
+	private function createNewAliases(string $userId, int $accountId, array $newAliases, string $displayName): void {
+		foreach ($newAliases as $newAlias) {
+			try {
+				$this->aliasMapper->findByAlias($newAlias, $userId);
+			} catch (DoesNotExistException $e) {
+				$alias = new Alias();
+				$alias->setAccountId($accountId);
+				$alias->setName($displayName);
+				$alias->setAlias($newAlias);
+				$this->aliasMapper->insert($alias);
+			}
+		}
+	}
+
+	/**
+	 * @throws \Exception if user id was not found in LDAP
+	 *
+	 * @TODO: Remove psalm-suppress once Mail requires Nextcloud 22 or above
+	 */
+	public function ldapAliasesIntegration(Provisioning $provisioning, IUser $user): Provisioning {
+		if ($user->getBackendClassName() !== 'LDAP' || $provisioning->getLdapAliasesProvisioning() === false || empty($provisioning->getLdapAliasesAttribute())) {
+			return $provisioning;
+		}
+
+		/** @psalm-suppress UndefinedInterfaceMethod */
+		if ($this->ldapProviderFactory->isAvailable() === false) {
+			$this->logger->debug('Request to provision mail aliases but ldap not available');
+			return $provisioning;
+		}
+
+		$ldapProvider = $this->ldapProviderFactory->getLDAPProvider();
+		/** @psalm-suppress UndefinedInterfaceMethod */
+		$provisioning->setAliases($ldapProvider->getMultiValueUserAttribute($user->getUID(), $provisioning->getLdapAliasesAttribute()));
+
+		return $provisioning;
+	}
+
+	/**
 	 * @param Provisioning[] $provisionings
 	 */
 	public function provisionSingleUser(array $provisionings, IUser $user): bool {
@@ -96,57 +179,69 @@ class Manager {
 
 		try {
 			// TODO: match by UID only, catch multiple objects returned below and delete all those accounts
-			$existing = $this->mailAccountMapper->findProvisionedAccount($user);
+			$mailAccount = $this->mailAccountMapper->findProvisionedAccount($user);
 
-			$this->mailAccountMapper->update(
-				$this->updateAccount($user, $existing, $provisioning)
+			$mailAccount = $this->mailAccountMapper->update(
+				$this->updateAccount($user, $mailAccount, $provisioning)
 			);
-			return true;
-		} catch (DoesNotExistException $e) {
+		} catch (DoesNotExistException | MultipleObjectsReturnedException $e) {
+			if ($e instanceof MultipleObjectsReturnedException) {
+				// This is unlikely to happen but not impossible.
+				// Let's wipe any existing accounts and start fresh
+				$this->aliasMapper->deleteProvisionedAliasesByUid($user->getUID());
+				$this->mailAccountMapper->deleteProvisionedAccountsByUid($user->getUID());
+			}
+
 			// Fine, then we create a new one
-			$new = new MailAccount();
-			$new->setUserId($user->getUID());
+			$mailAccount = new MailAccount();
+			$mailAccount->setUserId($user->getUID());
 
-			$this->mailAccountMapper->insert(
-				$this->updateAccount($user, $new, $provisioning)
+			$mailAccount = $this->mailAccountMapper->insert(
+				$this->updateAccount($user, $mailAccount, $provisioning)
 			);
-			return true;
-		} catch (MultipleObjectsReturnedException $e) {
-			// This is unlikely to happen but not impossible.
-			// Let's wipe any existing accounts and start fresh
-			$this->mailAccountMapper->deleteProvisionedAccountsByUid($user->getUID());
+		}
 
-			$new = new MailAccount();
-			$new->setUserId($user->getUID());
+		// @TODO: Remove method_exists once Mail requires Nextcloud 22 or above
+		if (method_exists(ILDAPProvider::class, 'getMultiValueUserAttribute')) {
+			try {
+				$provisioning = $this->ldapAliasesIntegration($provisioning, $user);
+			} catch (\Throwable $e) {
+				$this->logger->warning('Request to provision mail aliases failed', ['exception' => $e]);
+				// return here to avoid provisioning of aliases.
+				return true;
+			}
 
-			$this->mailAccountMapper->insert(
-				$this->updateAccount($user, $new, $provisioning)
-			);
-			return true;
+			try {
+				$this->deleteOrphanedAliases($user->getUID(), $mailAccount->getId(), $provisioning->getAliases());
+			} catch (\Throwable $e) {
+				$this->logger->warning('Deleting orphaned aliases failed', ['exception' => $e]);
+			}
+
+			try {
+				$this->createNewAliases($user->getUID(), $mailAccount->getId(), $provisioning->getAliases(), $user->getDisplayName());
+			} catch (\Throwable $e) {
+				$this->logger->warning('Creating new aliases failed', ['exception' => $e]);
+			}
 		}
-		return false;
+
+		return true;
 	}
 
+	/**
+	 * @throws ValidationException
+	 * @throws \Exception
+	 */
 	public function newProvisioning(array $data): void {
-		try {
-			$provisioning = $this->provisioningMapper->validate(
-				$data
-			);
-		} catch (ValidationException $e) {
-			throw $e;
-		}
+		$provisioning = $this->provisioningMapper->validate($data);
 		$this->provisioningMapper->insert($provisioning);
 	}
 
+	/**
+	 * @throws ValidationException
+	 * @throws \Exception
+	 */
 	public function updateProvisioning(array $data): void {
-		try {
-			$provisioning = $this->provisioningMapper->validate(
-				$data
-			);
-		} catch (ValidationException $e) {
-			throw $e;
-		}
-
+		$provisioning = $this->provisioningMapper->validate($data);
 		$this->provisioningMapper->update($provisioning);
 	}
 
diff --git a/lib/Settings/AdminSettings.php b/lib/Settings/AdminSettings.php
index 2a8d0fd4e..428201244 100644
--- a/lib/Settings/AdminSettings.php
+++ b/lib/Settings/AdminSettings.php
@@ -29,6 +29,7 @@ use OCA\Mail\AppInfo\Application;
 use OCA\Mail\Service\Provisioning\Manager as ProvisioningManager;
 use OCP\AppFramework\Http\TemplateResponse;
 use OCP\IInitialStateService;
+use OCP\LDAP\ILDAPProvider;
 use OCP\Settings\ISettings;
 
 class AdminSettings implements ISettings {
@@ -52,6 +53,14 @@ class AdminSettings implements ISettings {
 			$this->provisioningManager->getConfigs()
 		);
 
+		$this->initialStateService->provideLazyInitialState(
+			Application::APP_ID,
+			'ldap_aliases_integration',
+			function () {
+				return method_exists(ILDAPProvider::class, 'getMultiValueUserAttribute');
+			}
+		);
+
 		return new TemplateResponse(Application::APP_ID, 'settings-admin');
 	}