Merge pull request #26056 from nextcloud/backport/26031/stable21

[stable21] Allow autocomplete based on phone sync

.drone.yml

@@ -754,6 +754,31 @@ trigger:
     - pull_request
     - push
 
+---
+kind: pipeline
+name: integration-collaboration_features
+
+steps:
+- name: submodules
+  image: docker:git
+  commands:
+    - git submodule update --init
+- name: integration-collaboration_features
+  image: nextcloudci/integration-php7.3:integration-php7.3-2
+  commands:
+    - bash tests/drone-run-integration-tests.sh || exit 0
+    - ./occ maintenance:install --admin-pass=admin --data-dir=/dev/shm/nc_int
+    - cd build/integration
+    - ./run.sh collaboration_features/
+
+trigger:
+  branch:
+    - master
+    - stable*
+  event:
+    - pull_request
+    - push
+
 ---
 kind: pipeline
 name: integration-federation_features

apps/accessibility/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/admin_audit/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/cloud_federation_api/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/comments/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/contactsinteraction/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/dav/appinfo/v1/caldav.php

@@ -27,6 +27,7 @@
  */
 
 // Backends
+use OC\KnownUser\KnownUserService;
 use OCA\DAV\CalDAV\CalDavBackend;
 use OCA\DAV\Connector\LegacyDAVACL;
 use OCA\DAV\CalDAV\CalendarRoot;
@@ -50,6 +51,7 @@ $principalBackend = new Principal(
 	\OC::$server->getUserSession(),
 	\OC::$server->getAppManager(),
 	\OC::$server->query(\OCA\DAV\CalDAV\Proxy\ProxyMapper::class),
+	\OC::$server->get(KnownUserService::class),
 	\OC::$server->getConfig(),
 	'principals/'
 );

apps/dav/appinfo/v1/carddav.php

@@ -27,6 +27,7 @@
  */
 
 // Backends
+use OC\KnownUser\KnownUserService;
 use OCA\DAV\AppInfo\PluginManager;
 use OCA\DAV\CardDAV\AddressBookRoot;
 use OCA\DAV\CardDAV\CardDavBackend;
@@ -53,6 +54,7 @@ $principalBackend = new Principal(
 	\OC::$server->getUserSession(),
 	\OC::$server->getAppManager(),
 	\OC::$server->query(\OCA\DAV\CalDAV\Proxy\ProxyMapper::class),
+	\OC::$server->get(KnownUserService::class),
 	\OC::$server->getConfig(),
 	'principals/'
 );

apps/dav/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/dav/lib/CardDAV/SystemAddressbook.php

@@ -43,8 +43,9 @@ class SystemAddressbook extends AddressBook {
 
 	public function getChildren() {
 		$shareEnumeration = $this->config->getAppValue('core', 'shareapi_allow_share_dialog_user_enumeration', 'yes') === 'yes';
-		$restrictShareEnumeration = $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_to_group', 'no') === 'yes';
-		if (!$shareEnumeration || ($shareEnumeration && $restrictShareEnumeration)) {
+		$shareEnumerationGroup = $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_to_group', 'no') === 'yes';
+		$shareEnumerationPhone = $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_to_phone', 'no') === 'yes';
+		if (!$shareEnumeration || $shareEnumerationGroup || $shareEnumerationPhone) {
 			return [];
 		}
 

apps/dav/lib/Command/CreateCalendar.php

@@ -27,6 +27,7 @@
 
 namespace OCA\DAV\Command;
 
+use OC\KnownUser\KnownUserService;
 use OCA\DAV\CalDAV\CalDavBackend;
 use OCA\DAV\CalDAV\Proxy\ProxyMapper;
 use OCA\DAV\Connector\Sabre\Principal;
@@ -86,6 +87,7 @@ class CreateCalendar extends Command {
 			\OC::$server->getUserSession(),
 			\OC::$server->getAppManager(),
 			\OC::$server->query(ProxyMapper::class),
+			\OC::$server->get(KnownUserService::class),
 			\OC::$server->getConfig()
 		);
 		$random = \OC::$server->getSecureRandom();

apps/dav/lib/Connector/Sabre/Principal.php

@@ -36,6 +36,7 @@
 
 namespace OCA\DAV\Connector\Sabre;
 
+use OC\KnownUser\KnownUserService;
 use OCA\Circles\Exceptions\CircleDoesNotExistException;
 use OCA\DAV\CalDAV\Proxy\ProxyMapper;
 use OCA\DAV\Traits\PrincipalProxyTrait;
@@ -82,27 +83,19 @@ class Principal implements BackendInterface {
 	/** @var ProxyMapper */
 	private $proxyMapper;
 
+	/** @var KnownUserService */
+	private $knownUserService;
+
 	/** @var IConfig */
 	private $config;
 
-	/**
-	 * Principal constructor.
-	 *
-	 * @param IUserManager $userManager
-	 * @param IGroupManager $groupManager
-	 * @param IShareManager $shareManager
-	 * @param IUserSession $userSession
-	 * @param IAppManager $appManager
-	 * @param ProxyMapper $proxyMapper
-	 * @param IConfig $config
-	 * @param string $principalPrefix
-	 */
 	public function __construct(IUserManager $userManager,
 								IGroupManager $groupManager,
 								IShareManager $shareManager,
 								IUserSession $userSession,
 								IAppManager $appManager,
 								ProxyMapper $proxyMapper,
+								KnownUserService $knownUserService,
 								IConfig $config,
 								string $principalPrefix = 'principals/users/') {
 		$this->userManager = $userManager;
@@ -113,6 +106,7 @@ class Principal implements BackendInterface {
 		$this->principalPrefix = trim($principalPrefix, '/');
 		$this->hasGroups = $this->hasCircles = ($principalPrefix === 'principals/users/');
 		$this->proxyMapper = $proxyMapper;
+		$this->knownUserService = $knownUserService;
 		$this->config = $config;
 	}
 
@@ -267,24 +261,25 @@ class Principal implements BackendInterface {
 		}
 
 		$allowEnumeration = $this->shareManager->allowEnumeration();
-		$limitEnumeration = $this->shareManager->limitEnumerationToGroups();
+		$limitEnumerationGroup = $this->shareManager->limitEnumerationToGroups();
+		$limitEnumerationPhone = $this->shareManager->limitEnumerationToPhone();
+		$allowEnumerationFullMatch = $this->shareManager->allowEnumerationFullMatch();
 
 		// If sharing is restricted to group members only,
 		// return only members that have groups in common
 		$restrictGroups = false;
+		$currentUser = $this->userSession->getUser();
 		if ($this->shareManager->shareWithGroupMembersOnly()) {
-			$user = $this->userSession->getUser();
-			if (!$user) {
+			if (!$currentUser instanceof IUser) {
 				return [];
 			}
 
-			$restrictGroups = $this->groupManager->getUserGroupIds($user);
+			$restrictGroups = $this->groupManager->getUserGroupIds($currentUser);
 		}
 
 		$currentUserGroups = [];
-		if ($limitEnumeration) {
-			$currentUser = $this->userSession->getUser();
-			if ($currentUser) {
+		if ($limitEnumerationGroup) {
+			if ($currentUser instanceof IUser) {
 				$currentUserGroups = $this->groupManager->getUserGroupIds($currentUser);
 			}
 		}
@@ -296,20 +291,38 @@ class Principal implements BackendInterface {
 		foreach ($searchProperties as $prop => $value) {
 			switch ($prop) {
 				case '{http://sabredav.org/ns}email-address':
-					$users = $this->userManager->getByEmail($value);
-
 					if (!$allowEnumeration) {
+						if ($allowEnumerationFullMatch) {
+							$users = $this->userManager->getByEmail($value);
 							$users = \array_filter($users, static function (IUser $user) use ($value) {
 								return $user->getEMailAddress() === $value;
 							});
+						} else {
+							$users = [];
+						}
+					} else {
+						$users = $this->userManager->getByEmail($value);
+						$users = \array_filter($users, function (IUser $user) use ($currentUser, $value, $limitEnumerationPhone, $limitEnumerationGroup, $allowEnumerationFullMatch, $currentUserGroups) {
+							if ($allowEnumerationFullMatch && $user->getEMailAddress() === $value) {
+								return true;
 							}
 
-					if ($limitEnumeration) {
-						$users = \array_filter($users, function (IUser $user) use ($currentUserGroups, $value) {
-							return !empty(array_intersect(
+							if ($limitEnumerationPhone
+								&& $currentUser instanceof IUser
+								&& $this->knownUserService->isKnownToUser($currentUser->getUID(), $user->getUID())) {
+								// Synced phonebook match
+								return true;
+							}
+
+							if (!$limitEnumerationGroup) {
+								// No limitation on enumeration, all allowed
+								return true;
+							}
+
+							return !empty($currentUserGroups) && !empty(array_intersect(
 								$this->groupManager->getUserGroupIds($user),
 								$currentUserGroups
-								)) || $user->getEMailAddress() === $value;
+							));
 						});
 					}
 
@@ -328,20 +341,39 @@ class Principal implements BackendInterface {
 					break;
 
 				case '{DAV:}displayname':
-					$users = $this->userManager->searchDisplayName($value, $searchLimit);
 
 					if (!$allowEnumeration) {
+						if ($allowEnumerationFullMatch) {
+							$users = $this->userManager->searchDisplayName($value, $searchLimit);
 							$users = \array_filter($users, static function (IUser $user) use ($value) {
 								return $user->getDisplayName() === $value;
 							});
+						} else {
+							$users = [];
+						}
+					} else {
+						$users = $this->userManager->searchDisplayName($value, $searchLimit);
+						$users = \array_filter($users, function (IUser $user) use ($currentUser, $value, $limitEnumerationPhone, $limitEnumerationGroup, $allowEnumerationFullMatch, $currentUserGroups) {
+							if ($allowEnumerationFullMatch && $user->getDisplayName() === $value) {
+								return true;
 							}
 
-					if ($limitEnumeration) {
-						$users = \array_filter($users, function (IUser $user) use ($currentUserGroups, $value) {
-							return !empty(array_intersect(
+							if ($limitEnumerationPhone
+								&& $currentUser instanceof IUser
+								&& $this->knownUserService->isKnownToUser($currentUser->getUID(), $user->getUID())) {
+								// Synced phonebook match
+								return true;
+							}
+
+							if (!$limitEnumerationGroup) {
+								// No limitation on enumeration, all allowed
+								return true;
+							}
+
+							return !empty($currentUserGroups) && !empty(array_intersect(
 								$this->groupManager->getUserGroupIds($user),
 								$currentUserGroups
-								)) || $user->getDisplayName() === $value;
+							));
 						});
 					}
 

apps/dav/lib/RootCollection.php

@@ -28,6 +28,7 @@
 
 namespace OCA\DAV;
 
+use OC\KnownUser\KnownUserService;
 use OCA\DAV\AppInfo\PluginManager;
 use OCA\DAV\CalDAV\CalDavBackend;
 use OCA\DAV\CalDAV\CalendarRoot;
@@ -70,6 +71,7 @@ class RootCollection extends SimpleCollection {
 			\OC::$server->getUserSession(),
 			\OC::$server->getAppManager(),
 			$proxyMapper,
+			\OC::$server->get(KnownUserService::class),
 			\OC::$server->getConfig()
 		);
 		$groupPrincipalBackend = new GroupPrincipalBackend($groupManager, $userSession, $shareManager, $config);

apps/dav/tests/unit/CalDAV/AbstractCalDavBackend.php

@@ -27,6 +27,7 @@
 
 namespace OCA\DAV\Tests\unit\CalDAV;
 
+use OC\KnownUser\KnownUserService;
 use OCA\DAV\CalDAV\CalDavBackend;
 use OCA\DAV\CalDAV\Proxy\ProxyMapper;
 use OCA\DAV\Connector\Sabre\Principal;
@@ -92,6 +93,7 @@ abstract class AbstractCalDavBackend extends TestCase {
 				$this->createMock(IUserSession::class),
 				$this->createMock(IAppManager::class),
 				$this->createMock(ProxyMapper::class),
+				$this->createMock(KnownUserService::class),
 				$this->createMock(IConfig::class),
 			])
 			->setMethods(['getPrincipalByPath', 'getGroupMembership'])

apps/dav/tests/unit/CardDAV/CardDavBackendTest.php

@@ -33,6 +33,7 @@
 
 namespace OCA\DAV\Tests\unit\CardDAV;
 
+use OC\KnownUser\KnownUserService;
 use OCA\DAV\CalDAV\Proxy\ProxyMapper;
 use OCA\DAV\CardDAV\AddressBook;
 use OCA\DAV\CardDAV\CardDavBackend;
@@ -139,6 +140,7 @@ class CardDavBackendTest extends TestCase {
 				$this->createMock(IUserSession::class),
 				$this->createMock(IAppManager::class),
 				$this->createMock(ProxyMapper::class),
+				$this->createMock(KnownUserService::class),
 				$this->createMock(IConfig::class),
 			])
 			->setMethods(['getPrincipalByPath', 'getGroupMembership'])

apps/dav/tests/unit/Connector/Sabre/PrincipalTest.php

@@ -30,6 +30,7 @@
 
 namespace OCA\DAV\Tests\unit\Connector\Sabre;
 
+use OC\KnownUser\KnownUserService;
 use OC\User\User;
 use OCA\DAV\CalDAV\Proxy\Proxy;
 use OCA\DAV\CalDAV\Proxy\ProxyMapper;
@@ -41,6 +42,7 @@ use OCP\IUser;
 use OCP\IUserManager;
 use OCP\IUserSession;
 use OCP\Share\IManager;
+use PHPUnit\Framework\MockObject\MockObject;
 use Sabre\DAV\PropPatch;
 use Test\TestCase;
 
@@ -67,6 +69,8 @@ class PrincipalTest extends TestCase {
 	/** @var ProxyMapper | \PHPUnit\Framework\MockObject\MockObject */
 	private $proxyMapper;
 
+	/** @var KnownUserService|MockObject */
+	private $knownUserService;
 	/** @var IConfig | \PHPUnit\Framework\MockObject\MockObject */
 	private $config;
 
@@ -77,6 +81,7 @@ class PrincipalTest extends TestCase {
 		$this->userSession = $this->createMock(IUserSession::class);
 		$this->appManager = $this->createMock(IAppManager::class);
 		$this->proxyMapper = $this->createMock(ProxyMapper::class);
+		$this->knownUserService = $this->createMock(KnownUserService::class);
 		$this->config = $this->createMock(IConfig::class);
 
 		$this->connector = new \OCA\DAV\Connector\Sabre\Principal(
@@ -86,6 +91,7 @@ class PrincipalTest extends TestCase {
 			$this->userSession,
 			$this->appManager,
 			$this->proxyMapper,
+			$this->knownUserService,
 			$this->config
 		);
 		parent::setUp();
@@ -442,7 +448,7 @@ class PrincipalTest extends TestCase {
 
 			if ($groupsOnly) {
 				$user = $this->createMock(IUser::class);
-				$this->userSession->expects($this->once())
+				$this->userSession->expects($this->atLeastOnce())
 					->method('getUser')
 					->willReturn($user);
 
@@ -564,6 +570,10 @@ class PrincipalTest extends TestCase {
 			->method('shareWithGroupMembersOnly')
 			->willReturn(false);
 
+		$this->shareManager->expects($this->once())
+			->method('allowEnumerationFullMatch')
+			->willReturn(true);
+
 		$user2 = $this->createMock(IUser::class);
 		$user2->method('getUID')->willReturn('user2');
 		$user2->method('getDisplayName')->willReturn('User 2');
@@ -586,6 +596,27 @@ class PrincipalTest extends TestCase {
 			['{DAV:}displayname' => 'User 2']));
 	}
 
+	public function testSearchPrincipalWithEnumerationDisabledDisplaynameOnFullMatch() {
+		$this->shareManager->expects($this->once())
+			->method('shareAPIEnabled')
+			->willReturn(true);
+
+		$this->shareManager->expects($this->once())
+			->method('allowEnumeration')
+			->willReturn(false);
+
+		$this->shareManager->expects($this->once())
+			->method('shareWithGroupMembersOnly')
+			->willReturn(false);
+
+		$this->shareManager->expects($this->once())
+			->method('allowEnumerationFullMatch')
+			->willReturn(false);
+
+		$this->assertEquals([], $this->connector->searchPrincipals('principals/users',
+			['{DAV:}displayname' => 'User 2']));
+	}
+
 	public function testSearchPrincipalWithEnumerationDisabledEmail() {
 		$this->shareManager->expects($this->once())
 			->method('shareAPIEnabled')
@@ -599,6 +630,10 @@ class PrincipalTest extends TestCase {
 			->method('shareWithGroupMembersOnly')
 			->willReturn(false);
 
+		$this->shareManager->expects($this->once())
+			->method('allowEnumerationFullMatch')
+			->willReturn(true);
+
 		$user2 = $this->createMock(IUser::class);
 		$user2->method('getUID')->willReturn('user2');
 		$user2->method('getDisplayName')->willReturn('User 2');
@@ -621,6 +656,28 @@ class PrincipalTest extends TestCase {
 			['{http://sabredav.org/ns}email-address' => 'user2@foo.bar']));
 	}
 
+	public function testSearchPrincipalWithEnumerationDisabledEmailOnFullMatch() {
+		$this->shareManager->expects($this->once())
+			->method('shareAPIEnabled')
+			->willReturn(true);
+
+		$this->shareManager->expects($this->once())
+			->method('allowEnumeration')
+			->willReturn(false);
+
+		$this->shareManager->expects($this->once())
+			->method('shareWithGroupMembersOnly')
+			->willReturn(false);
+
+		$this->shareManager->expects($this->once())
+			->method('allowEnumerationFullMatch')
+			->willReturn(false);
+
+
+		$this->assertEquals([], $this->connector->searchPrincipals('principals/users',
+			['{http://sabredav.org/ns}email-address' => 'user2@foo.bar']));
+	}
+
 	public function testSearchPrincipalWithEnumerationLimitedDisplayname() {
 		$this->shareManager->expects($this->at(0))
 			->method('shareAPIEnabled')

apps/encryption/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/federatedfilesharing/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/federation/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/files/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/files_sharing/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/files_trashbin/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/files_versions/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/files_versions/lib/AppInfo/Application.php

@@ -27,6 +27,7 @@
 
 namespace OCA\Files_Versions\AppInfo;
 
+use OC\KnownUser\KnownUserService;
 use OCA\DAV\CalDAV\Proxy\ProxyMapper;
 use OCA\DAV\Connector\Sabre\Principal;
 use OCA\Files\Event\LoadAdditionalScriptsEvent;
@@ -72,6 +73,7 @@ class Application extends App implements IBootstrap {
 				$server->getUserSession(),
 				$server->getAppManager(),
 				$server->get(ProxyMapper::class),
+				$server->get(KnownUserService::class),
 				$server->getConfig()
 			);
 		});

apps/lookup_server_connector/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/oauth2/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/provisioning_api/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/provisioning_api/composer/composer/autoload_classmap.php

@@ -14,6 +14,7 @@ return array(
     'OCA\\Provisioning_API\\Controller\\GroupsController' => $baseDir . '/../lib/Controller/GroupsController.php',
     'OCA\\Provisioning_API\\Controller\\UsersController' => $baseDir . '/../lib/Controller/UsersController.php',
     'OCA\\Provisioning_API\\FederatedShareProviderFactory' => $baseDir . '/../lib/FederatedShareProviderFactory.php',
+    'OCA\\Provisioning_API\\Listener\\UserDeletedListener' => $baseDir . '/../lib/Listener/UserDeletedListener.php',
     'OCA\\Provisioning_API\\Middleware\\Exceptions\\NotSubAdminException' => $baseDir . '/../lib/Middleware/Exceptions/NotSubAdminException.php',
     'OCA\\Provisioning_API\\Middleware\\ProvisioningApiMiddleware' => $baseDir . '/../lib/Middleware/ProvisioningApiMiddleware.php',
 );

apps/provisioning_api/composer/composer/autoload_static.php

@@ -29,6 +29,7 @@ class ComposerStaticInitProvisioning_API
         'OCA\\Provisioning_API\\Controller\\GroupsController' => __DIR__ . '/..' . '/../lib/Controller/GroupsController.php',
         'OCA\\Provisioning_API\\Controller\\UsersController' => __DIR__ . '/..' . '/../lib/Controller/UsersController.php',
         'OCA\\Provisioning_API\\FederatedShareProviderFactory' => __DIR__ . '/..' . '/../lib/FederatedShareProviderFactory.php',
+        'OCA\\Provisioning_API\\Listener\\UserDeletedListener' => __DIR__ . '/..' . '/../lib/Listener/UserDeletedListener.php',
         'OCA\\Provisioning_API\\Middleware\\Exceptions\\NotSubAdminException' => __DIR__ . '/..' . '/../lib/Middleware/Exceptions/NotSubAdminException.php',
         'OCA\\Provisioning_API\\Middleware\\ProvisioningApiMiddleware' => __DIR__ . '/..' . '/../lib/Middleware/ProvisioningApiMiddleware.php',
     );

apps/provisioning_api/lib/AppInfo/Application.php

@@ -29,6 +29,7 @@
 namespace OCA\Provisioning_API\AppInfo;
 
 use OC\Group\Manager as GroupManager;
+use OCA\Provisioning_API\Listener\UserDeletedListener;
 use OCA\Provisioning_API\Middleware\ProvisioningApiMiddleware;
 use OCA\Settings\Mailer\NewUserMailHelper;
 use OCP\AppFramework\App;
@@ -47,6 +48,7 @@ use OCP\L10N\IFactory;
 use OCP\Mail\IMailer;
 use OCP\Security\ICrypto;
 use OCP\Security\ISecureRandom;
+use OCP\User\Events\UserDeletedEvent;
 use OCP\Util;
 use Psr\Container\ContainerInterface;
 
@@ -56,6 +58,8 @@ class Application extends App implements IBootstrap {
 	}
 
 	public function register(IRegistrationContext $context): void {
+		$context->registerEventListener(UserDeletedEvent::class, UserDeletedListener::class);
+
 		$context->registerService(NewUserMailHelper::class, function (ContainerInterface $c) {
 			return new NewUserMailHelper(
 				$c->get(Defaults::class),

apps/provisioning_api/lib/Controller/UsersController.php

@@ -49,6 +49,7 @@ use libphonenumber\PhoneNumberUtil;
 use OC\Accounts\AccountManager;
 use OC\Authentication\Token\RemoteWipe;
 use OC\HintException;
+use OC\KnownUser\KnownUserService;
 use OCA\Provisioning_API\FederatedShareProviderFactory;
 use OCA\Settings\Mailer\NewUserMailHelper;
 use OCP\Accounts\IAccountManager;
@@ -89,6 +90,8 @@ class UsersController extends AUserData {
 	private $secureRandom;
 	/** @var RemoteWipe */
 	private $remoteWipe;
+	/** @var KnownUserService */
+	private $knownUserService;
 	/** @var IEventDispatcher */
 	private $eventDispatcher;
 
@@ -107,6 +110,7 @@ class UsersController extends AUserData {
 								FederatedShareProviderFactory $federatedShareProviderFactory,
 								ISecureRandom $secureRandom,
 								RemoteWipe $remoteWipe,
+								KnownUserService $knownUserService,
 								IEventDispatcher $eventDispatcher) {
 		parent::__construct($appName,
 							$request,
@@ -125,6 +129,7 @@ class UsersController extends AUserData {
 		$this->federatedShareProviderFactory = $federatedShareProviderFactory;
 		$this->secureRandom = $secureRandom;
 		$this->remoteWipe = $remoteWipe;
+		$this->knownUserService = $knownUserService;
 		$this->eventDispatcher = $eventDispatcher;
 	}
 
@@ -230,6 +235,13 @@ class UsersController extends AUserData {
 			return new DataResponse([], Http::STATUS_BAD_REQUEST);
 		}
 
+		/** @var IUser $user */
+		$user = $this->userSession->getUser();
+		$knownTo = $user->getUID();
+
+		// Cleanup all previous entries and only allow new matches
+		$this->knownUserService->deleteKnownTo($knownTo);
+
 		$normalizedNumberToKey = [];
 		foreach ($search as $key => $phoneNumbers) {
 			foreach ($phoneNumbers as $phone) {
@@ -267,6 +279,7 @@ class UsersController extends AUserData {
 		foreach ($userMatches as $phone => $userId) {
 			// Not using the ICloudIdManager as that would run a search for each contact to find the display name in the address book
 			$matches[$normalizedNumberToKey[$phone]] = $userId . '@' . $cloudUrl;
+			$this->knownUserService->storeIsKnownToUser($knownTo, $userId);
 		}
 
 		return new DataResponse($matches);
@@ -664,6 +677,10 @@ class UsersController extends AUserData {
 					$userAccount[$key]['value'] = $value;
 					try {
 						$this->accountManager->updateUser($targetUser, $userAccount, true);
+
+						if ($key === IAccountManager::PROPERTY_PHONE) {
+							$this->knownUserService->deleteByContactUserId($targetUser->getUID());
+						}
 					} catch (\InvalidArgumentException $e) {
 						throw new OCSException('Invalid ' . $e->getMessage(), 102);
 					}

apps/provisioning_api/lib/Listener/UserDeletedListener.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2020 Joas Schilling <coding@schilljs.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\Provisioning_API\Listener;
+
+use OC\KnownUser\KnownUserService;
+use OCP\EventDispatcher\Event;
+use OCP\EventDispatcher\IEventListener;
+use OCP\User\Events\UserDeletedEvent;
+
+class UserDeletedListener implements IEventListener {
+
+	/** @var KnownUserService */
+	private $service;
+
+	public function __construct(KnownUserService $service) {
+		$this->service = $service;
+	}
+
+	public function handle(Event $event): void {
+		if (!($event instanceof UserDeletedEvent)) {
+			// Unrelated
+			return;
+		}
+
+		$user = $event->getUser();
+
+		// Delete all entries of this user
+		$this->service->deleteKnownTo($user->getUID());
+
+		// Delete all entries that other users know this user
+		$this->service->deleteByContactUserId($user->getUID());
+	}
+}

apps/provisioning_api/tests/Controller/UsersControllerTest.php

@@ -44,6 +44,7 @@ use Exception;
 use OC\Accounts\AccountManager;
 use OC\Authentication\Token\RemoteWipe;
 use OC\Group\Manager;
+use OC\KnownUser\KnownUserService;
 use OC\SubAdmin;
 use OCA\FederatedFileSharing\FederatedShareProvider;
 use OCA\Provisioning_API\Controller\UsersController;
@@ -102,6 +103,8 @@ class UsersControllerTest extends TestCase {
 	private $secureRandom;
 	/** @var RemoteWipe|MockObject */
 	private $remoteWipe;
+	/** @var KnownUserService|MockObject */
+	private $knownUserService;
 	/** @var IEventDispatcher */
 	private $eventDispatcher;
 
@@ -122,6 +125,7 @@ class UsersControllerTest extends TestCase {
 		$this->federatedShareProviderFactory = $this->createMock(FederatedShareProviderFactory::class);
 		$this->secureRandom = $this->createMock(ISecureRandom::class);
 		$this->remoteWipe = $this->createMock(RemoteWipe::class);
+		$this->knownUserService = $this->createMock(KnownUserService::class);
 		$this->eventDispatcher = $this->createMock(IEventDispatcher::class);
 
 		$this->api = $this->getMockBuilder(UsersController::class)
@@ -141,6 +145,7 @@ class UsersControllerTest extends TestCase {
 				$this->federatedShareProviderFactory,
 				$this->secureRandom,
 				$this->remoteWipe,
+				$this->knownUserService,
 				$this->eventDispatcher,
 			])
 			->setMethods(['fillStorageInfo'])
@@ -405,6 +410,7 @@ class UsersControllerTest extends TestCase {
 				$this->federatedShareProviderFactory,
 				$this->secureRandom,
 				$this->remoteWipe,
+				$this->knownUserService,
 				$this->eventDispatcher,
 			])
 			->setMethods(['editUser'])
@@ -1399,6 +1405,13 @@ class UsersControllerTest extends TestCase {
 	 * @param array $expected
 	 */
 	public function testSearchByPhoneNumbers(string $location, array $search, int $status, ?array $searchUsers, ?array $userMatches, array $expected) {
+		$knownTo = 'knownTo';
+		$user = $this->createMock(IUser::class);
+		$user->method('getUID')
+			->willReturn($knownTo);
+		$this->userSession->method('getUser')
+			->willReturn($user);
+
 		if ($searchUsers === null) {
 			$this->accountManager->expects($this->never())
 				->method('searchUsers');
@@ -1407,6 +1420,14 @@ class UsersControllerTest extends TestCase {
 				->method('searchUsers')
 				->with(IAccountManager::PROPERTY_PHONE, $searchUsers)
 				->willReturn($userMatches);
+
+			$this->knownUserService->expects($this->once())
+				->method('deleteKnownTo')
+				->with($knownTo);
+
+			$this->knownUserService->expects($this->exactly(count($expected)))
+				->method('storeIsKnownToUser')
+				->with($knownTo, $this->anything());
 		}
 
 		$this->urlGenerator->method('getAbsoluteURL')
@@ -3228,6 +3249,7 @@ class UsersControllerTest extends TestCase {
 				$this->federatedShareProviderFactory,
 				$this->secureRandom,
 				$this->remoteWipe,
+				$this->knownUserService,
 				$this->eventDispatcher,
 			])
 			->setMethods(['getUserData'])
@@ -3294,6 +3316,7 @@ class UsersControllerTest extends TestCase {
 				$this->federatedShareProviderFactory,
 				$this->secureRandom,
 				$this->remoteWipe,
+				$this->knownUserService,
 				$this->eventDispatcher,
 			])
 			->setMethods(['getUserData'])

apps/settings/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/settings/js/admin.js

@@ -144,6 +144,8 @@ window.addEventListener('DOMContentLoaded', function(){
 
 	$('#shareapi_allow_share_dialog_user_enumeration').on('change', function() {
 		$('#shareapi_restrict_user_enumeration_to_group_setting').toggleClass('hidden', !this.checked);
+		$('#shareapi_restrict_user_enumeration_to_phone_setting').toggleClass('hidden', !this.checked);
+		$('#shareapi_restrict_user_enumeration_combinewarning_setting').toggleClass('hidden', !this.checked);
 	})
 
 	$('#allowLinks').change(function() {

apps/settings/lib/Controller/UsersController.php

@@ -42,6 +42,7 @@ use OC\AppFramework\Http;
 use OC\Encryption\Exceptions\ModuleDoesNotExistsException;
 use OC\ForbiddenException;
 use OC\Group\Manager as GroupManager;
+use OC\KnownUser\KnownUserService;
 use OC\L10N\Factory;
 use OC\Security\IdentityProof\Manager;
 use OC\User\Manager as UserManager;
@@ -96,6 +97,8 @@ class UsersController extends Controller {
 	private $jobList;
 	/** @var IManager */
 	private $encryptionManager;
+	/** @var KnownUserService */
+	private $knownUserService;
 	/** @var IEventDispatcher */
 	private $dispatcher;
 
@@ -116,6 +119,7 @@ class UsersController extends Controller {
 		Manager $keyManager,
 		IJobList $jobList,
 		IManager $encryptionManager,
+		KnownUserService $knownUserService,
 		IEventDispatcher $dispatcher
 	) {
 		parent::__construct($appName, $request);
@@ -132,6 +136,7 @@ class UsersController extends Controller {
 		$this->keyManager = $keyManager;
 		$this->jobList = $jobList;
 		$this->encryptionManager = $encryptionManager;
+		$this->knownUserService = $knownUserService;
 		$this->dispatcher = $dispatcher;
 	}
 
@@ -363,6 +368,19 @@ class UsersController extends Controller {
 									?string $twitter = null,
 									?string $twitterScope = null
 	) {
+		$user = $this->userSession->getUser();
+		if (!$user instanceof IUser) {
+			return new DataResponse(
+				[
+					'status' => 'error',
+					'data' => [
+						'message' => $this->l10n->t('Invalid user')
+					]
+				],
+				Http::STATUS_UNAUTHORIZED
+			);
+		}
+
 		$email = strtolower($email);
 		if (!empty($email) && !$this->mailer->validateMailAddress($email)) {
 			return new DataResponse(
@@ -375,8 +393,9 @@ class UsersController extends Controller {
 				Http::STATUS_UNPROCESSABLE_ENTITY
 			);
 		}
-		$user = $this->userSession->getUser();
+
 		$data = $this->accountManager->getUser($user);
+		$beforeData = $data;
 		$data[IAccountManager::PROPERTY_AVATAR] = ['scope' => $avatarScope];
 		if ($this->config->getSystemValue('allow_user_to_change_display_name', true) !== false) {
 			$data[IAccountManager::PROPERTY_DISPLAYNAME] = ['value' => $displayname, 'scope' => $displaynameScope];
@@ -393,6 +412,9 @@ class UsersController extends Controller {
 		}
 		try {
 			$data = $this->saveUserSettings($user, $data);
+			if ($beforeData[IAccountManager::PROPERTY_PHONE]['value'] !== $data[IAccountManager::PROPERTY_PHONE]['value']) {
+				$this->knownUserService->deleteByContactUserId($user->getUID());
+			}
 			return new DataResponse(
 				[
 					'status' => 'success',

apps/settings/lib/Settings/Admin/Sharing.php

@@ -73,6 +73,8 @@ class Sharing implements ISettings {
 			'allowResharing' => $this->config->getAppValue('core', 'shareapi_allow_resharing', 'yes'),
 			'allowShareDialogUserEnumeration' => $this->config->getAppValue('core', 'shareapi_allow_share_dialog_user_enumeration', 'yes'),
 			'restrictUserEnumerationToGroup' => $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_to_group', 'no'),
+			'restrictUserEnumerationToPhone' => $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_to_phone', 'no'),
+			'restrictUserEnumerationFullMatch' => $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_full_match', 'yes'),
 			'enforceLinkPassword' => Util::isPublicLinkPasswordRequired(),
 			'onlyShareWithGroupMembers' => $this->shareManager->shareWithGroupMembersOnly(),
 			'shareAPIEnabled' => $this->config->getAppValue('core', 'shareapi_enabled', 'yes'),

apps/settings/templates/settings/admin/sharing.php

@@ -163,7 +163,7 @@
 			<?php if ($_['allowShareDialogUserEnumeration'] === 'yes') {
 	print_unescaped('checked="checked"');
 } ?> />
-		<label for="shareapi_allow_share_dialog_user_enumeration"><?php p($l->t('Allow username autocompletion in share dialog (if this is disabled the full username or email address needs to be entered)'));?></label><br />
+		<label for="shareapi_allow_share_dialog_user_enumeration"><?php p($l->t('Allow username autocompletion in share dialog'));?></label><br />
 	</p>
 
 	<p id="shareapi_restrict_user_enumeration_to_group_setting" class="indent <?php if ($_['shareAPIEnabled'] === 'no' || $_['allowShareDialogUserEnumeration'] === 'no') {
@@ -173,7 +173,31 @@
 			<?php if ($_['restrictUserEnumerationToGroup'] === 'yes') {
 	print_unescaped('checked="checked"');
 } ?> />
-		<label for="shareapi_restrict_user_enumeration_to_group"><?php p($l->t('Restrict username autocompletion to users within the same groups'));?></label><br />
+		<label for="shareapi_restrict_user_enumeration_to_group"><?php p($l->t('Allow username autocompletion to users within the same groups'));?></label><br />
+	</p>
+
+	<p id="shareapi_restrict_user_enumeration_to_phone_setting" class="indent <?php if ($_['shareAPIEnabled'] === 'no' || $_['allowShareDialogUserEnumeration'] === 'no') {
+	p('hidden');
+}?>">
+		<input type="checkbox" name="shareapi_restrict_user_enumeration_to_phone" value="1" id="shareapi_restrict_user_enumeration_to_phone" class="checkbox"
+			<?php if ($_['restrictUserEnumerationToPhone'] === 'yes') {
+	print_unescaped('checked="checked"');
+} ?> />
+		<label for="shareapi_restrict_user_enumeration_to_phone"><?php p($l->t('Allow username autocompletion to users based on phonebook matches'));?></label><br />
+	</p>
+	<p id="shareapi_restrict_user_enumeration_combinewarning_setting" class="indent <?php if ($_['shareAPIEnabled'] === 'no' || $_['allowShareDialogUserEnumeration'] === 'no') {
+	p('hidden');
+}?>">
+		<em><?php p($l->t('If autocompletion "same group" and "phonebook matches" are enabled a match in either is enough to show the user.'));?></em><br />
+	</p>
+	<p id="shareapi_restrict_user_enumeration_full_match_setting" class="indent <?php if ($_['shareAPIEnabled'] === 'no') {
+	p('hidden');
+}?>">
+		<input type="checkbox" name="shareapi_restrict_user_enumeration_full_match" value="1" id="shareapi_restrict_user_enumeration_full_match" class="checkbox"
+				<?php if ($_['restrictUserEnumerationFullMatch'] === 'yes') {
+	print_unescaped('checked="checked"');
+} ?> />
+		<label for="shareapi_restrict_user_enumeration_full_match"><?php p($l->t('Allow username autocompletion when entering the full name or email address (ignoring missing phonebook match and being in the same group)'));?></label><br />
 	</p>
 
 	<p>

apps/settings/tests/Controller/UsersControllerTest.php

@@ -32,6 +32,7 @@ namespace OCA\Settings\Tests\Controller;
 use OC\Accounts\AccountManager;
 use OC\Encryption\Exceptions\ModuleDoesNotExistsException;
 use OC\Group\Manager;
+use OC\KnownUser\KnownUserService;
 use OCA\Settings\Controller\UsersController;
 use OCP\Accounts\IAccountManager;
 use OCP\App\IAppManager;
@@ -91,6 +92,8 @@ class UsersControllerTest extends \Test\TestCase {
 	private $securityManager;
 	/** @var  IManager | \PHPUnit\Framework\MockObject\MockObject */
 	private $encryptionManager;
+	/** @var KnownUserService|\PHPUnit\Framework\MockObject\MockObject */
+	private $knownUserService;
 	/** @var  IEncryptionModule  | \PHPUnit\Framework\MockObject\MockObject */
 	private $encryptionModule;
 	/** @var IEventDispatcher|\PHPUnit\Framework\MockObject\MockObject */
@@ -111,6 +114,7 @@ class UsersControllerTest extends \Test\TestCase {
 		$this->securityManager = $this->getMockBuilder(\OC\Security\IdentityProof\Manager::class)->disableOriginalConstructor()->getMock();
 		$this->jobList = $this->createMock(IJobList::class);
 		$this->encryptionManager = $this->createMock(IManager::class);
+		$this->knownUserService = $this->createMock(KnownUserService::class);
 		$this->dispatcher = $this->createMock(IEventDispatcher::class);
 
 		$this->l->method('t')
@@ -147,6 +151,7 @@ class UsersControllerTest extends \Test\TestCase {
 				$this->securityManager,
 				$this->jobList,
 				$this->encryptionManager,
+				$this->knownUserService,
 				$this->dispatcher
 			);
 		} else {
@@ -168,6 +173,7 @@ class UsersControllerTest extends \Test\TestCase {
 						$this->securityManager,
 						$this->jobList,
 						$this->encryptionManager,
+						$this->knownUserService,
 						$this->dispatcher
 					]
 				)->setMethods($mockedMethods)->getMock();

apps/settings/tests/Settings/Admin/SharingTest.php

@@ -64,95 +64,29 @@ class SharingTest extends TestCase {
 
 	public function testGetFormWithoutExcludedGroups() {
 		$this->config
-			->expects($this->at(0))
 			->method('getAppValue')
-			->with('core', 'shareapi_exclude_groups_list', '')
-			->willReturn('');
-		$this->config
-			->expects($this->at(1))
-			->method('getAppValue')
-			->with('core', 'shareapi_allow_group_sharing', 'yes')
-			->willReturn('yes');
-		$this->config
-			->expects($this->at(2))
-			->method('getAppValue')
-			->with('core', 'shareapi_allow_links', 'yes')
-			->willReturn('yes');
-		$this->config
-			->expects($this->at(3))
-			->method('getAppValue')
-			->with('core', 'shareapi_allow_public_upload', 'yes')
-			->willReturn('yes');
-		$this->config
-			->expects($this->at(4))
-			->method('getAppValue')
-			->with('core', 'shareapi_allow_resharing', 'yes')
-			->willReturn('yes');
-		$this->config
-			->expects($this->at(5))
-			->method('getAppValue')
-			->with('core', 'shareapi_allow_share_dialog_user_enumeration', 'yes')
-			->willReturn('yes');
-		$this->config
-			->expects($this->at(6))
-			->method('getAppValue')
-			->with('core', 'shareapi_restrict_user_enumeration_to_group', 'no')
-			->willReturn('no');
-		$this->config
-			->expects($this->at(7))
-			->method('getAppValue')
-			->with('core', 'shareapi_enabled', 'yes')
-			->willReturn('yes');
-		$this->config
-			->expects($this->at(8))
-			->method('getAppValue')
-			->with('core', 'shareapi_default_expire_date', 'no')
-			->willReturn('no');
-		$this->config
-			->expects($this->at(9))
-			->method('getAppValue')
-			->with('core', 'shareapi_expire_after_n_days', '7')
-			->willReturn('7');
-		$this->config
-			->expects($this->at(10))
-			->method('getAppValue')
-			->with('core', 'shareapi_enforce_expire_date', 'no')
-			->willReturn('no');
-		$this->config
-			->expects($this->at(11))
-			->method('getAppValue')
-			->with('core', 'shareapi_exclude_groups', 'no')
-			->willReturn('no');
-		$this->config
-			->expects($this->at(12))
-			->method('getAppValue')
-			->with('core', 'shareapi_public_link_disclaimertext', null)
-			->willReturn('Lorem ipsum');
-		$this->config
-			->expects($this->at(13))
-			->method('getAppValue')
-			->with('core', 'shareapi_enable_link_password_by_default', 'no')
-			->willReturn('yes');
-		$this->config
-			->expects($this->at(14))
-			->method('getAppValue')
-			->with('core', 'shareapi_default_permissions', Constants::PERMISSION_ALL)
-			->willReturn(Constants::PERMISSION_ALL);
-		$this->config
-			->expects($this->at(15))
-			->method('getAppValue')
-			->with('core', 'shareapi_default_internal_expire_date', 'no')
-			->willReturn('no');
-		$this->config
-			->expects($this->at(16))
-			->method('getAppValue')
-			->with('core', 'shareapi_internal_expire_after_n_days', '7')
-			->willReturn('7');
-		$this->config
-			->expects($this->at(17))
-			->method('getAppValue')
-			->with('core', 'shareapi_enforce_internal_expire_date', 'no')
-			->willReturn('no');
+			->willReturnMap([
+				['core', 'shareapi_exclude_groups_list', '', ''],
+				['core', 'shareapi_allow_group_sharing', 'yes', 'yes'],
+				['core', 'shareapi_allow_links', 'yes', 'yes'],
+				['core', 'shareapi_allow_public_upload', 'yes', 'yes'],
+				['core', 'shareapi_allow_resharing', 'yes', 'yes'],
+				['core', 'shareapi_allow_share_dialog_user_enumeration', 'yes', 'yes'],
+				['core', 'shareapi_restrict_user_enumeration_to_group', 'no', 'no'],
+				['core', 'shareapi_restrict_user_enumeration_to_phone', 'no', 'no'],
+				['core', 'shareapi_restrict_user_enumeration_full_match', 'yes', 'yes'],
+				['core', 'shareapi_enabled', 'yes', 'yes'],
+				['core', 'shareapi_default_expire_date', 'no', 'no'],
+				['core', 'shareapi_expire_after_n_days', '7', '7'],
+				['core', 'shareapi_enforce_expire_date', 'no', 'no'],
+				['core', 'shareapi_exclude_groups', 'no', 'no'],
+				['core', 'shareapi_public_link_disclaimertext', null, 'Lorem ipsum'],
+				['core', 'shareapi_enable_link_password_by_default', 'no', 'yes'],
+				['core', 'shareapi_default_permissions', Constants::PERMISSION_ALL, Constants::PERMISSION_ALL],
+				['core', 'shareapi_default_internal_expire_date', 'no', 'no'],
+				['core', 'shareapi_internal_expire_after_n_days', '7', '7'],
+				['core', 'shareapi_enforce_internal_expire_date', 'no', 'no'],
+			]);
 
 		$expected = new TemplateResponse(
 			'settings',
@@ -164,6 +98,8 @@ class SharingTest extends TestCase {
 				'allowResharing' => 'yes',
 				'allowShareDialogUserEnumeration' => 'yes',
 				'restrictUserEnumerationToGroup' => 'no',
+				'restrictUserEnumerationToPhone' => 'no',
+				'restrictUserEnumerationFullMatch' => 'yes',
 				'enforceLinkPassword' => false,
 				'onlyShareWithGroupMembers' => false,
 				'shareAPIEnabled' => 'yes',
@@ -188,96 +124,29 @@ class SharingTest extends TestCase {
 
 	public function testGetFormWithExcludedGroups() {
 		$this->config
-			->expects($this->at(0))
 			->method('getAppValue')
-			->with('core', 'shareapi_exclude_groups_list', '')
-			->willReturn('["NoSharers","OtherNoSharers"]');
-		$this->config
-			->expects($this->at(1))
-			->method('getAppValue')
-			->with('core', 'shareapi_allow_group_sharing', 'yes')
-			->willReturn('yes');
-		$this->config
-			->expects($this->at(2))
-			->method('getAppValue')
-			->with('core', 'shareapi_allow_links', 'yes')
-			->willReturn('yes');
-		$this->config
-			->expects($this->at(3))
-			->method('getAppValue')
-			->with('core', 'shareapi_allow_public_upload', 'yes')
-			->willReturn('yes');
-		$this->config
-			->expects($this->at(4))
-			->method('getAppValue')
-			->with('core', 'shareapi_allow_resharing', 'yes')
-			->willReturn('yes');
-		$this->config
-			->expects($this->at(5))
-			->method('getAppValue')
-			->with('core', 'shareapi_allow_share_dialog_user_enumeration', 'yes')
-			->willReturn('yes');
-		$this->config
-			->expects($this->at(6))
-			->method('getAppValue')
-			->with('core', 'shareapi_restrict_user_enumeration_to_group', 'no')
-			->willReturn('no');
-		$this->config
-			->expects($this->at(7))
-			->method('getAppValue')
-			->with('core', 'shareapi_enabled', 'yes')
-			->willReturn('yes');
-		$this->config
-			->expects($this->at(8))
-			->method('getAppValue')
-			->with('core', 'shareapi_default_expire_date', 'no')
-			->willReturn('no');
-		$this->config
-			->expects($this->at(9))
-			->method('getAppValue')
-			->with('core', 'shareapi_expire_after_n_days', '7')
-			->willReturn('7');
-		$this->config
-			->expects($this->at(10))
-			->method('getAppValue')
-			->with('core', 'shareapi_enforce_expire_date', 'no')
-			->willReturn('no');
-		$this->config
-			->expects($this->at(11))
-			->method('getAppValue')
-			->with('core', 'shareapi_exclude_groups', 'no')
-			->willReturn('yes');
-		$this->config
-			->expects($this->at(12))
-			->method('getAppValue')
-			->with('core', 'shareapi_public_link_disclaimertext', null)
-			->willReturn('Lorem ipsum');
-		$this->config
-			->expects($this->at(13))
-			->method('getAppValue')
-			->with('core', 'shareapi_enable_link_password_by_default', 'no')
-			->willReturn('yes');
-		$this->config
-			->expects($this->at(14))
-			->method('getAppValue')
-			->with('core', 'shareapi_default_permissions', Constants::PERMISSION_ALL)
-			->willReturn(Constants::PERMISSION_ALL);
-		$this->config
-			->expects($this->at(15))
-			->method('getAppValue')
-			->with('core', 'shareapi_default_internal_expire_date', 'no')
-			->willReturn('no');
-		$this->config
-			->expects($this->at(16))
-			->method('getAppValue')
-			->with('core', 'shareapi_internal_expire_after_n_days', '7')
-			->willReturn('7');
-		$this->config
-			->expects($this->at(17))
-			->method('getAppValue')
-			->with('core', 'shareapi_enforce_internal_expire_date', 'no')
-			->willReturn('no');
-
+			->willReturnMap([
+				['core', 'shareapi_exclude_groups_list', '', '["NoSharers","OtherNoSharers"]'],
+				['core', 'shareapi_allow_group_sharing', 'yes', 'yes'],
+				['core', 'shareapi_allow_links', 'yes', 'yes'],
+				['core', 'shareapi_allow_public_upload', 'yes', 'yes'],
+				['core', 'shareapi_allow_resharing', 'yes', 'yes'],
+				['core', 'shareapi_allow_share_dialog_user_enumeration', 'yes', 'yes'],
+				['core', 'shareapi_restrict_user_enumeration_to_group', 'no', 'no'],
+				['core', 'shareapi_restrict_user_enumeration_to_phone', 'no', 'no'],
+				['core', 'shareapi_restrict_user_enumeration_full_match', 'yes', 'yes'],
+				['core', 'shareapi_enabled', 'yes', 'yes'],
+				['core', 'shareapi_default_expire_date', 'no', 'no'],
+				['core', 'shareapi_expire_after_n_days', '7', '7'],
+				['core', 'shareapi_enforce_expire_date', 'no', 'no'],
+				['core', 'shareapi_exclude_groups', 'no', 'yes'],
+				['core', 'shareapi_public_link_disclaimertext', null, 'Lorem ipsum'],
+				['core', 'shareapi_enable_link_password_by_default', 'no', 'yes'],
+				['core', 'shareapi_default_permissions', Constants::PERMISSION_ALL, Constants::PERMISSION_ALL],
+				['core', 'shareapi_default_internal_expire_date', 'no', 'no'],
+				['core', 'shareapi_internal_expire_after_n_days', '7', '7'],
+				['core', 'shareapi_enforce_internal_expire_date', 'no', 'no'],
+			]);
 
 		$expected = new TemplateResponse(
 			'settings',
@@ -289,6 +158,8 @@ class SharingTest extends TestCase {
 				'allowResharing' => 'yes',
 				'allowShareDialogUserEnumeration' => 'yes',
 				'restrictUserEnumerationToGroup' => 'no',
+				'restrictUserEnumerationToPhone' => 'no',
+				'restrictUserEnumerationFullMatch' => 'yes',
 				'enforceLinkPassword' => false,
 				'onlyShareWithGroupMembers' => false,
 				'shareAPIEnabled' => 'yes',

apps/sharebymail/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/systemtags/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/testing/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/twofactor_backupcodes/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/updatenotification/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/user_ldap/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/user_status/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

apps/workflowengine/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

build/integration/collaboration_features/autocomplete.feature

@@ -0,0 +1,218 @@
+Feature: autocomplete
+  Background:
+    Given using api version "2"
+    And group "commongroup" exists
+    And user "admin" belongs to group "commongroup"
+    And user "auto" exists
+    And user "autocomplete" exists
+    And user "autocomplete2" exists
+    And user "autocomplete2" belongs to group "commongroup"
+
+  Scenario: getting autocomplete
+    Given As an "admin"
+    When get autocomplete for "auto"
+      | id | source |
+      | auto | users |
+      | autocomplete | users |
+      | autocomplete2 | users |
+    When parameter "shareapi_restrict_user_enumeration_full_match" of app "core" is set to "no"
+    Then get autocomplete for "auto"
+      | id | source |
+      | auto | users |
+      | autocomplete | users |
+      | autocomplete2 | users |
+
+
+  Scenario: getting autocomplete without enumeration
+    Given As an "admin"
+    When parameter "shareapi_allow_share_dialog_user_enumeration" of app "core" is set to "no"
+    Then get autocomplete for "auto"
+      | id | source |
+      | auto | users |
+    Then get autocomplete for "autocomplete"
+      | id | source |
+      | autocomplete | users |
+    When parameter "shareapi_restrict_user_enumeration_full_match" of app "core" is set to "no"
+    Then get autocomplete for "auto"
+      | id | source |
+    Then get autocomplete for "autocomplete"
+      | id | source |
+
+
+  Scenario: getting autocomplete with limited enumeration by group
+    Given As an "admin"
+    When parameter "shareapi_restrict_user_enumeration_to_group" of app "core" is set to "yes"
+    Then get autocomplete for "auto"
+      | id | source |
+      | auto | users |
+      | autocomplete2 | users |
+    Then get autocomplete for "autocomplete"
+      | id | source |
+      | autocomplete | users |
+      | autocomplete2 | users |
+    Then get autocomplete for "autocomplete2"
+      | id | source |
+      | autocomplete2 | users |
+    When parameter "shareapi_restrict_user_enumeration_full_match" of app "core" is set to "no"
+    Then get autocomplete for "autocomplete"
+      | id | source |
+      | autocomplete2 | users |
+    Then get autocomplete for "autocomplete2"
+      | id | source |
+      | autocomplete2 | users |
+
+
+  Scenario: getting autocomplete with limited enumeration by phone
+    Given As an "admin"
+    When parameter "shareapi_restrict_user_enumeration_to_phone" of app "core" is set to "yes"
+    Then get autocomplete for "auto"
+      | id | source |
+      | auto | users |
+
+    # autocomplete stores their phone number
+    Given As an "autocomplete"
+    And sending "PUT" to "/cloud/users/autocomplete" with
+      | key | phone |
+      | value | +49 711 / 25 24 28-90 |
+    And the HTTP status code should be "200"
+    And the OCS status code should be "200"
+
+    Given As an "admin"
+    Then get autocomplete for "auto"
+      | id | source |
+      | auto | users |
+
+    # admin populates they have the phone number
+    When search users by phone for region "DE" with
+      | random-string1 | 0711 / 252 428-90 |
+    Then get autocomplete for "auto"
+      | id | source |
+      | auto | users |
+      | autocomplete | users |
+
+    When parameter "shareapi_restrict_user_enumeration_full_match" of app "core" is set to "no"
+    Then get autocomplete for "auto"
+      | id | source |
+      | autocomplete | users |
+
+
+  Scenario: getting autocomplete with limited enumeration by group or phone
+    Given As an "admin"
+    When parameter "shareapi_restrict_user_enumeration_to_group" of app "core" is set to "yes"
+    And parameter "shareapi_restrict_user_enumeration_to_phone" of app "core" is set to "yes"
+
+    # autocomplete stores their phone number
+    Given As an "autocomplete"
+    And sending "PUT" to "/cloud/users/autocomplete" with
+      | key | phone |
+      | value | +49 711 / 25 24 28-90 |
+    And the HTTP status code should be "200"
+    And the OCS status code should be "200"
+    # admin populates they have the phone number
+    Given As an "admin"
+    When search users by phone for region "DE" with
+      | random-string1 | 0711 / 252 428-90 |
+
+    Then get autocomplete for "auto"
+      | id | source |
+      | auto | users |
+      | autocomplete | users |
+      | autocomplete2 | users |
+
+    When parameter "shareapi_restrict_user_enumeration_full_match" of app "core" is set to "no"
+    Then get autocomplete for "auto"
+      | id | source |
+      | autocomplete | users |
+      | autocomplete2 | users |
+
+
+  Scenario: getting autocomplete with limited enumeration but sharing is group restricted
+    Given As an "admin"
+    When parameter "shareapi_restrict_user_enumeration_to_group" of app "core" is set to "yes"
+    And parameter "shareapi_restrict_user_enumeration_to_phone" of app "core" is set to "yes"
+
+    # autocomplete stores their phone number
+    Given As an "autocomplete"
+    And sending "PUT" to "/cloud/users/autocomplete" with
+      | key | phone |
+      | value | +49 711 / 25 24 28-90 |
+    And the HTTP status code should be "200"
+    And the OCS status code should be "200"
+    # admin populates they have the phone number
+    Given As an "admin"
+    When search users by phone for region "DE" with
+      | random-string1 | 0711 / 252 428-90 |
+
+    Then get autocomplete for "auto"
+      | id | source |
+      | auto | users |
+      | autocomplete | users |
+      | autocomplete2 | users |
+    When parameter "shareapi_only_share_with_group_members" of app "core" is set to "yes"
+    Then get autocomplete for "auto"
+      | id | source |
+      | autocomplete2 | users |
+
+
+  Scenario: getting autocomplete with limited enumeration by phone but user changes it
+    Given As an "admin"
+    When parameter "shareapi_restrict_user_enumeration_to_phone" of app "core" is set to "yes"
+    Then get autocomplete for "auto"
+      | id | source |
+      | auto | users |
+
+    # autocomplete stores their phone number
+    Given As an "autocomplete"
+    And sending "PUT" to "/cloud/users/autocomplete" with
+      | key | phone |
+      | value | +49 711 / 25 24 28-90 |
+    And the HTTP status code should be "200"
+    And the OCS status code should be "200"
+
+    Given As an "admin"
+    Then get autocomplete for "auto"
+      | id | source |
+      | auto | users |
+
+    # admin populates they have the phone number
+    When search users by phone for region "DE" with
+      | random-string1 | 0711 / 252 428-90 |
+    Then get autocomplete for "auto"
+      | id | source |
+      | auto | users |
+      | autocomplete | users |
+
+    # autocomplete changes their phone number
+    Given As an "autocomplete"
+    And sending "PUT" to "/cloud/users/autocomplete" with
+      | key | phone |
+      | value | +49 711 / 25 24 28-91 |
+    And the HTTP status code should be "200"
+    And the OCS status code should be "200"
+
+    Given As an "admin"
+    Then get autocomplete for "auto"
+      | id | source |
+      | auto | users |
+
+    # admin populates they have the new phone number
+    When search users by phone for region "DE" with
+      | random-string1 | 0711 / 252 428-91 |
+    Then get autocomplete for "auto"
+      | id | source |
+      | auto | users |
+      | autocomplete | users |
+
+
+  Scenario: getting autocomplete without enumeration and sharing is group restricted
+    Given As an "admin"
+    When parameter "shareapi_allow_share_dialog_user_enumeration" of app "core" is set to "no"
+    And parameter "shareapi_only_share_with_group_members" of app "core" is set to "yes"
+
+    Then get autocomplete for "auto"
+      | id | source |
+    Then get autocomplete for "autocomplete"
+      | id | source |
+    Then get autocomplete for "autocomplete2"
+      | id | source |
+      | autocomplete2 | users |

build/integration/config/behat.yml

@@ -45,6 +45,16 @@ default:
               - admin
               - admin
             regular_user_password: 123456
+    collaboration:
+      paths:
+        - "%paths.base%/../collaboration_features"
+      contexts:
+        - CollaborationContext:
+            baseUrl:  http://localhost:8080/ocs/
+            admin:
+              - admin
+              - admin
+            regular_user_password: 123456
     sharees:
       paths:
         - "%paths.base%/../sharees_features"

build/integration/features/bootstrap/BasicStructure.php

@@ -202,6 +202,40 @@ trait BasicStructure {
 		}
 	}
 
+	/**
+	 * @param string $verb
+	 * @param string $url
+	 * @param TableNode|array|null $body
+	 * @param array $headers
+	 */
+	protected function sendRequestForJSON(string $verb, string $url, $body = null, array $headers = []): void {
+		$fullUrl = $this->baseUrl . "v{$this->apiVersion}.php" . $url;
+		$client = new Client();
+		$options = [];
+		if ($this->currentUser === 'admin') {
+			$options['auth'] = ['admin', 'admin'];
+		} elseif (strpos($this->currentUser, 'guest') !== 0) {
+			$options['auth'] = [$this->currentUser, self::TEST_PASSWORD];
+		}
+		if ($body instanceof TableNode) {
+			$fd = $body->getRowsHash();
+			$options['form_params'] = $fd;
+		} elseif (is_array($body)) {
+			$options['form_params'] = $body;
+		}
+
+		$options['headers'] = array_merge($headers, [
+			'OCS-ApiRequest' => 'true',
+			'Accept' => 'application/json',
+		]);
+
+		try {
+			$this->response = $client->{$verb}($fullUrl, $options);
+		} catch (ClientException $ex) {
+			$this->response = $ex->getResponse();
+		}
+	}
+
 	/**
 	 * @When /^sending "([^"]*)" with exact url to "([^"]*)"$/
 	 * @param string $verb

build/integration/features/bootstrap/CollaborationContext.php

@@ -0,0 +1,72 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2021, Joas Schilling <coding@schilljs.com>
+ *
+ * @author Joas Schilling <coding@schilljs.com>
+ *
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program. If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+use Behat\Behat\Context\Context;
+use Behat\Gherkin\Node\TableNode;
+use PHPUnit\Framework\Assert;
+
+require __DIR__ . '/../../vendor/autoload.php';
+
+class CollaborationContext implements Context {
+	use Provisioning;
+	use AppConfiguration;
+
+	/**
+	 * @Then /^get autocomplete for "([^"]*)"$/
+	 * @param TableNode|null $formData
+	 */
+	public function getAutocomplete(string $search, TableNode $formData): void {
+		$query = $search === 'null' ? null : $search;
+
+		$this->sendRequestForJSON('GET', '/core/autocomplete/get?itemType=files&itemId=123&search=' . $query, [
+			'itemType' => 'files',
+			'itemId' => '123',
+			'search' => $query,
+		]);
+		$this->theHTTPStatusCodeShouldBe(200);
+
+		$data = json_decode($this->response->getBody()->getContents(), true);
+		$suggestions = $data['ocs']['data'];
+
+		Assert::assertCount(count($formData->getHash()), $suggestions, 'Suggestion count does not match');
+		Assert::assertEquals($formData->getHash(), array_map(static function ($suggestion, $expected) {
+			$data = [];
+			if (isset($expected['id'])) {
+				$data['id'] = $suggestion['id'];
+			}
+			if (isset($expected['source'])) {
+				$data['source'] = $suggestion['source'];
+			}
+			return $data;
+		}, $suggestions, $formData->getHash()));
+	}
+
+	protected function resetAppConfigs(): void {
+		$this->deleteServerConfig('core', 'shareapi_allow_share_dialog_user_enumeration');
+		$this->deleteServerConfig('core', 'shareapi_restrict_user_enumeration_to_group');
+		$this->deleteServerConfig('core', 'shareapi_restrict_user_enumeration_to_phone');
+		$this->deleteServerConfig('core', 'shareapi_restrict_user_enumeration_full_match');
+		$this->deleteServerConfig('core', 'shareapi_only_share_with_group_members');
+	}
+}

core/Migrations/Version21000Date20210309185126.php

@@ -0,0 +1,69 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2021 Joas Schilling <coding@schilljs.com>
+ *
+ * @author Joas Schilling <coding@schilljs.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+namespace OC\Core\Migrations;
+
+use Closure;
+use Doctrine\DBAL\Types\Types;
+use OCP\DB\ISchemaWrapper;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+
+class Version21000Date20210309185126 extends SimpleMigrationStep {
+	/**
+	 * @param IOutput $output
+	 * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
+	 * @param array $options
+	 * @return null|ISchemaWrapper
+	 */
+	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+
+		if (!$schema->hasTable('known_users')) {
+			$table = $schema->createTable('known_users');
+
+			// Auto increment id
+			$table->addColumn('id', Types::BIGINT, [
+				'autoincrement' => true,
+				'notnull' => true,
+			]);
+
+			$table->addColumn('known_to', Types::STRING, [
+				'notnull' => true,
+				'length' => 255,
+			]);
+			$table->addColumn('known_user', Types::STRING, [
+				'notnull' => true,
+				'length' => 255,
+			]);
+
+			$table->setPrimaryKey(['id']);
+			$table->addIndex(['known_to'], 'ku_known_to');
+			return $schema;
+		}
+
+		return null;
+	}
+}

lib/composer/composer/ClassLoader.php

@@ -311,8 +311,10 @@ class ClassLoader
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
 
         if (null === $this->vendorDir) {
-            //no-op
-        } elseif ($prepend) {
+            return;
+        }
+
+        if ($prepend) {
             self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
         } else {
             unset(self::$registeredLoaders[$this->vendorDir]);

lib/composer/composer/autoload_classmap.php

@@ -950,6 +950,7 @@ return array(
     'OC\\Core\\Migrations\\Version21000Date20201120141228' => $baseDir . '/core/Migrations/Version21000Date20201120141228.php',
     'OC\\Core\\Migrations\\Version21000Date20201202095923' => $baseDir . '/core/Migrations/Version21000Date20201202095923.php',
     'OC\\Core\\Migrations\\Version21000Date20210119195004' => $baseDir . '/core/Migrations/Version21000Date20210119195004.php',
+    'OC\\Core\\Migrations\\Version21000Date20210309185126' => $baseDir . '/core/Migrations/Version21000Date20210309185126.php',
     'OC\\Core\\Notification\\CoreNotifier' => $baseDir . '/core/Notification/CoreNotifier.php',
     'OC\\Core\\Service\\LoginFlowV2Service' => $baseDir . '/core/Service/LoginFlowV2Service.php',
     'OC\\DB\\Adapter' => $baseDir . '/lib/private/DB/Adapter.php',
@@ -1168,6 +1169,9 @@ return array(
     'OC\\IntegrityCheck\\Helpers\\FileAccessHelper' => $baseDir . '/lib/private/IntegrityCheck/Helpers/FileAccessHelper.php',
     'OC\\IntegrityCheck\\Iterator\\ExcludeFileByNameFilterIterator' => $baseDir . '/lib/private/IntegrityCheck/Iterator/ExcludeFileByNameFilterIterator.php',
     'OC\\IntegrityCheck\\Iterator\\ExcludeFoldersByPathFilterIterator' => $baseDir . '/lib/private/IntegrityCheck/Iterator/ExcludeFoldersByPathFilterIterator.php',
+    'OC\\KnownUser\\KnownUser' => $baseDir . '/lib/private/KnownUser/KnownUser.php',
+    'OC\\KnownUser\\KnownUserMapper' => $baseDir . '/lib/private/KnownUser/KnownUserMapper.php',
+    'OC\\KnownUser\\KnownUserService' => $baseDir . '/lib/private/KnownUser/KnownUserService.php',
     'OC\\L10N\\Factory' => $baseDir . '/lib/private/L10N/Factory.php',
     'OC\\L10N\\L10N' => $baseDir . '/lib/private/L10N/L10N.php',
     'OC\\L10N\\L10NString' => $baseDir . '/lib/private/L10N/L10NString.php',

lib/composer/composer/autoload_static.php

@@ -979,6 +979,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\Core\\Migrations\\Version21000Date20201120141228' => __DIR__ . '/../../..' . '/core/Migrations/Version21000Date20201120141228.php',
         'OC\\Core\\Migrations\\Version21000Date20201202095923' => __DIR__ . '/../../..' . '/core/Migrations/Version21000Date20201202095923.php',
         'OC\\Core\\Migrations\\Version21000Date20210119195004' => __DIR__ . '/../../..' . '/core/Migrations/Version21000Date20210119195004.php',
+        'OC\\Core\\Migrations\\Version21000Date20210309185126' => __DIR__ . '/../../..' . '/core/Migrations/Version21000Date20210309185126.php',
         'OC\\Core\\Notification\\CoreNotifier' => __DIR__ . '/../../..' . '/core/Notification/CoreNotifier.php',
         'OC\\Core\\Service\\LoginFlowV2Service' => __DIR__ . '/../../..' . '/core/Service/LoginFlowV2Service.php',
         'OC\\DB\\Adapter' => __DIR__ . '/../../..' . '/lib/private/DB/Adapter.php',
@@ -1197,6 +1198,9 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\IntegrityCheck\\Helpers\\FileAccessHelper' => __DIR__ . '/../../..' . '/lib/private/IntegrityCheck/Helpers/FileAccessHelper.php',
         'OC\\IntegrityCheck\\Iterator\\ExcludeFileByNameFilterIterator' => __DIR__ . '/../../..' . '/lib/private/IntegrityCheck/Iterator/ExcludeFileByNameFilterIterator.php',
         'OC\\IntegrityCheck\\Iterator\\ExcludeFoldersByPathFilterIterator' => __DIR__ . '/../../..' . '/lib/private/IntegrityCheck/Iterator/ExcludeFoldersByPathFilterIterator.php',
+        'OC\\KnownUser\\KnownUser' => __DIR__ . '/../../..' . '/lib/private/KnownUser/KnownUser.php',
+        'OC\\KnownUser\\KnownUserMapper' => __DIR__ . '/../../..' . '/lib/private/KnownUser/KnownUserMapper.php',
+        'OC\\KnownUser\\KnownUserService' => __DIR__ . '/../../..' . '/lib/private/KnownUser/KnownUserService.php',
         'OC\\L10N\\Factory' => __DIR__ . '/../../..' . '/lib/private/L10N/Factory.php',
         'OC\\L10N\\L10N' => __DIR__ . '/../../..' . '/lib/private/L10N/L10N.php',
         'OC\\L10N\\L10NString' => __DIR__ . '/../../..' . '/lib/private/L10N/L10NString.php',

lib/private/Collaboration/Collaborators/MailPlugin.php

@@ -27,6 +27,7 @@
 
 namespace OC\Collaboration\Collaborators;
 
+use OC\KnownUser\KnownUserService;
 use OCP\Collaboration\Collaborators\ISearchPlugin;
 use OCP\Collaboration\Collaborators\ISearchResult;
 use OCP\Collaboration\Collaborators\SearchResultType;
@@ -40,8 +41,16 @@ use OCP\IUserSession;
 use OCP\Share\IShare;
 
 class MailPlugin implements ISearchPlugin {
-	protected $shareeEnumeration;
+	/* @var bool */
 	protected $shareWithGroupOnly;
+	/* @var bool */
+	protected $shareeEnumeration;
+	/* @var bool */
+	protected $shareeEnumerationInGroupOnly;
+	/* @var bool */
+	protected $shareeEnumerationPhone;
+	/* @var bool */
+	protected $shareeEnumerationFullMatch;
 
 	/** @var IManager */
 	private $contactsManager;
@@ -52,20 +61,29 @@ class MailPlugin implements ISearchPlugin {
 
 	/** @var IGroupManager */
 	private $groupManager;
-
+	/** @var KnownUserService */
+	private $knownUserService;
 	/** @var IUserSession */
 	private $userSession;
 
-	public function __construct(IManager $contactsManager, ICloudIdManager $cloudIdManager, IConfig $config, IGroupManager $groupManager, IUserSession $userSession) {
+	public function __construct(IManager $contactsManager,
+								ICloudIdManager $cloudIdManager,
+								IConfig $config,
+								IGroupManager $groupManager,
+								KnownUserService $knownUserService,
+								IUserSession $userSession) {
 		$this->contactsManager = $contactsManager;
 		$this->cloudIdManager = $cloudIdManager;
 		$this->config = $config;
 		$this->groupManager = $groupManager;
+		$this->knownUserService = $knownUserService;
 		$this->userSession = $userSession;
 
 		$this->shareeEnumeration = $this->config->getAppValue('core', 'shareapi_allow_share_dialog_user_enumeration', 'yes') === 'yes';
 		$this->shareWithGroupOnly = $this->config->getAppValue('core', 'shareapi_only_share_with_group_members', 'no') === 'yes';
 		$this->shareeEnumerationInGroupOnly = $this->shareeEnumeration && $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_to_group', 'no') === 'yes';
+		$this->shareeEnumerationPhone = $this->shareeEnumeration && $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_to_phone', 'no') === 'yes';
+		$this->shareeEnumerationFullMatch = $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_full_match', 'yes') === 'yes';
 	}
 
 	/**
@@ -77,6 +95,8 @@ class MailPlugin implements ISearchPlugin {
 	 * @since 13.0.0
 	 */
 	public function search($search, $limit, $offset, ISearchResult $searchResult) {
+		$currentUserId = $this->userSession->getUser()->getUID();
+
 		$result = $userResults = ['wide' => [], 'exact' => []];
 		$userType = new SearchResultType('users');
 		$emailType = new SearchResultType('emails');
@@ -120,7 +140,7 @@ class MailPlugin implements ISearchPlugin {
 								continue;
 							}
 						}
-						if ($exactEmailMatch) {
+						if ($exactEmailMatch && $this->shareeEnumerationFullMatch) {
 							try {
 								$cloud = $this->cloudIdManager->resolveCloudId($contact['CLOUD'][0]);
 							} catch (\InvalidArgumentException $e) {
@@ -152,8 +172,12 @@ class MailPlugin implements ISearchPlugin {
 								continue;
 							}
 
-							$addToWide = !$this->shareeEnumerationInGroupOnly;
-							if ($this->shareeEnumerationInGroupOnly) {
+							$addToWide = !($this->shareeEnumerationInGroupOnly || $this->shareeEnumerationPhone);
+							if (!$addToWide && $this->shareeEnumerationPhone && $this->knownUserService->isKnownToUser($currentUserId, $contact['UID'])) {
+								$addToWide = true;
+							}
+
+							if (!$addToWide && $this->shareeEnumerationInGroupOnly) {
 								$addToWide = false;
 								$userGroups = $this->groupManager->getUserGroupIds($this->userSession->getUser());
 								foreach ($userGroups as $userGroup) {
@@ -181,7 +205,7 @@ class MailPlugin implements ISearchPlugin {
 					}
 
 					if ($exactEmailMatch
-						|| isset($contact['FN']) && strtolower($contact['FN']) === $lowerSearch) {
+						|| (isset($contact['FN']) && strtolower($contact['FN']) === $lowerSearch)) {
 						if ($exactEmailMatch) {
 							$searchResult->markExactIdMatch($emailType);
 						}

lib/private/Collaboration/Collaborators/UserPlugin.php

@@ -32,6 +32,7 @@
 
 namespace OC\Collaboration\Collaborators;
 
+use OC\KnownUser\KnownUserService;
 use OCP\Collaboration\Collaborators\ISearchPlugin;
 use OCP\Collaboration\Collaborators\ISearchResult;
 use OCP\Collaboration\Collaborators\SearchResultType;
@@ -46,8 +47,14 @@ use OCP\UserStatus\IManager as IUserStatusManager;
 class UserPlugin implements ISearchPlugin {
 	/* @var bool */
 	protected $shareWithGroupOnly;
+	/* @var bool */
 	protected $shareeEnumeration;
+	/* @var bool */
 	protected $shareeEnumerationInGroupOnly;
+	/* @var bool */
+	protected $shareeEnumerationPhone;
+	/* @var bool */
+	protected $shareeEnumerationFullMatch;
 
 	/** @var IConfig */
 	private $config;
@@ -57,33 +64,30 @@ class UserPlugin implements ISearchPlugin {
 	private $userSession;
 	/** @var IUserManager */
 	private $userManager;
+	/** @var KnownUserService */
+	private $knownUserService;
 	/** @var IUserStatusManager */
 	private $userStatusManager;
 
-	/**
-	 * UserPlugin constructor.
-	 *
-	 * @param IConfig $config
-	 * @param IUserManager $userManager
-	 * @param IGroupManager $groupManager
-	 * @param IUserSession $userSession
-	 * @param IUserStatusManager $userStatusManager
-	 */
 	public function __construct(IConfig $config,
 								IUserManager $userManager,
 								IGroupManager $groupManager,
 								IUserSession $userSession,
+								KnownUserService $knownUserService,
 								IUserStatusManager $userStatusManager) {
 		$this->config = $config;
 
 		$this->groupManager = $groupManager;
 		$this->userSession = $userSession;
 		$this->userManager = $userManager;
+		$this->knownUserService = $knownUserService;
 		$this->userStatusManager = $userStatusManager;
 
 		$this->shareWithGroupOnly = $this->config->getAppValue('core', 'shareapi_only_share_with_group_members', 'no') === 'yes';
 		$this->shareeEnumeration = $this->config->getAppValue('core', 'shareapi_allow_share_dialog_user_enumeration', 'yes') === 'yes';
 		$this->shareeEnumerationInGroupOnly = $this->shareeEnumeration && $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_to_group', 'no') === 'yes';
+		$this->shareeEnumerationPhone = $this->shareeEnumeration && $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_to_phone', 'no') === 'yes';
+		$this->shareeEnumerationFullMatch = $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_full_match', 'yes') === 'yes';
 	}
 
 	public function search($search, $limit, $offset, ISearchResult $searchResult) {
@@ -91,6 +95,7 @@ class UserPlugin implements ISearchPlugin {
 		$users = [];
 		$hasMoreResults = false;
 
+		$currentUserId = $this->userSession->getUser()->getUID();
 		$currentUserGroups = $this->groupManager->getUserGroupIds($this->userSession->getUser());
 		if ($this->shareWithGroupOnly) {
 			// Search in all the groups this user is part of
@@ -148,6 +153,7 @@ class UserPlugin implements ISearchPlugin {
 
 
 			if (
+				$this->shareeEnumerationFullMatch &&
 				$lowerSearch !== '' && (strtolower($uid) === $lowerSearch ||
 				strtolower($userDisplayName) === $lowerSearch ||
 				strtolower($userEmail) === $lowerSearch)
@@ -168,11 +174,16 @@ class UserPlugin implements ISearchPlugin {
 				];
 			} else {
 				$addToWideResults = false;
-				if ($this->shareeEnumeration && !$this->shareeEnumerationInGroupOnly) {
+				if ($this->shareeEnumeration &&
+					!($this->shareeEnumerationInGroupOnly || $this->shareeEnumerationPhone)) {
 					$addToWideResults = true;
 				}
 
-				if ($this->shareeEnumerationInGroupOnly) {
+				if ($this->shareeEnumerationPhone && $this->knownUserService->isKnownToUser($currentUserId, $user->getUID())) {
+					$addToWideResults = true;
+				}
+
+				if (!$addToWideResults && $this->shareeEnumerationInGroupOnly) {
 					$commonGroups = array_intersect($currentUserGroups, $this->groupManager->getUserGroupIds($user));
 					if (!empty($commonGroups)) {
 						$addToWideResults = true;
@@ -195,7 +206,7 @@ class UserPlugin implements ISearchPlugin {
 			}
 		}
 
-		if ($offset === 0 && !$foundUserById) {
+		if ($this->shareeEnumerationFullMatch && $offset === 0 && !$foundUserById) {
 			// On page one we try if the search result has a direct hit on the
 			// user id and if so, we add that to the exact match list
 			$user = $this->userManager->get($search);

lib/private/Contacts/ContactsMenu/ContactsStore.php

@@ -31,6 +31,7 @@
 
 namespace OC\Contacts\ContactsMenu;
 
+use OC\KnownUser\KnownUserService;
 use OCP\Contacts\ContactsMenu\IContactsStore;
 use OCP\Contacts\ContactsMenu\IEntry;
 use OCP\Contacts\IManager;
@@ -53,20 +54,19 @@ class ContactsStore implements IContactsStore {
 	/** @var IGroupManager */
 	private $groupManager;
 
-	/**
-	 * @param IManager $contactsManager
-	 * @param IConfig $config
-	 * @param IUserManager $userManager
-	 * @param IGroupManager $groupManager
-	 */
+	/** @var KnownUserService */
+	private $knownUserService;
+
 	public function __construct(IManager $contactsManager,
 								IConfig $config,
 								IUserManager $userManager,
-								IGroupManager $groupManager) {
+								IGroupManager $groupManager,
+								KnownUserService $knownUserService) {
 		$this->contactsManager = $contactsManager;
 		$this->config = $config;
 		$this->userManager = $userManager;
 		$this->groupManager = $groupManager;
+		$this->knownUserService = $knownUserService;
 	}
 
 	/**
@@ -103,7 +103,7 @@ class ContactsStore implements IContactsStore {
 	}
 
 	/**
-	 * Filters the contacts. Applies 3 filters:
+	 * Filters the contacts. Applied filters:
 	 *  1. filter the current user
 	 *  2. if the `shareapi_allow_share_dialog_user_enumeration` config option is
 	 * enabled it will filter all local users
@@ -122,20 +122,22 @@ class ContactsStore implements IContactsStore {
 									array $entries,
 									$filter) {
 		$disallowEnumeration = $this->config->getAppValue('core', 'shareapi_allow_share_dialog_user_enumeration', 'yes') !== 'yes';
-		$restrictEnumeration = $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_to_group', 'no') === 'yes';
+		$restrictEnumerationGroup = $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_to_group', 'no') === 'yes';
+		$restrictEnumerationPhone = $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_to_phone', 'no') === 'yes';
+		$allowEnumerationFullMatch = $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_full_match', 'yes') === 'yes';
 		$excludedGroups = $this->config->getAppValue('core', 'shareapi_exclude_groups', 'no') === 'yes';
 
 		// whether to filter out local users
 		$skipLocal = false;
-		// whether to filter out all users which doesn't have the same group as the current user
-		$ownGroupsOnly = $this->config->getAppValue('core', 'shareapi_only_share_with_group_members', 'no') === 'yes' || $restrictEnumeration;
+		// whether to filter out all users which don't have a common group as the current user
+		$ownGroupsOnly = $this->config->getAppValue('core', 'shareapi_only_share_with_group_members', 'no') === 'yes';
 
 		$selfGroups = $this->groupManager->getUserGroupIds($self);
 
 		if ($excludedGroups) {
 			$excludedGroups = $this->config->getAppValue('core', 'shareapi_exclude_groups_list', '');
 			$decodedExcludeGroups = json_decode($excludedGroups, true);
-			$excludeGroupsList = ($decodedExcludeGroups !== null) ? $decodedExcludeGroups : [];
+			$excludeGroupsList = $decodedExcludeGroups ?? [];
 
 			if (count(array_intersect($excludeGroupsList, $selfGroups)) !== 0) {
 				// a group of the current user is excluded -> filter all local users
@@ -145,47 +147,80 @@ class ContactsStore implements IContactsStore {
 
 		$selfUID = $self->getUID();
 
-		return array_values(array_filter($entries, function (IEntry $entry) use ($self, $skipLocal, $ownGroupsOnly, $selfGroups, $selfUID, $disallowEnumeration, $filter) {
-			if ($skipLocal && $entry->getProperty('isLocalSystemBook') === true) {
+		return array_values(array_filter($entries, function (IEntry $entry) use ($skipLocal, $ownGroupsOnly, $selfGroups, $selfUID, $disallowEnumeration, $restrictEnumerationGroup, $restrictEnumerationPhone, $allowEnumerationFullMatch, $filter) {
+			if ($entry->getProperty('UID') === $selfUID) {
 				return false;
 			}
 
+			if ($entry->getProperty('isLocalSystemBook')) {
+				if ($skipLocal) {
+					return false;
+				}
+
+				$checkedCommonGroupAlready = false;
+
 				// Prevent enumerating local users
-			if ($disallowEnumeration && $entry->getProperty('isLocalSystemBook')) {
-				$filterUser = true;
+				if ($disallowEnumeration) {
+					if (!$allowEnumerationFullMatch) {
+						return false;
+					}
+
+					$filterOutUser = true;
 
 					$mailAddresses = $entry->getEMailAddresses();
 					foreach ($mailAddresses as $mailAddress) {
 						if ($mailAddress === $filter) {
-						$filterUser = false;
+							$filterOutUser = false;
 							break;
 						}
 					}
 
 					if ($entry->getProperty('UID') && $entry->getProperty('UID') === $filter) {
-					$filterUser = false;
+						$filterOutUser = false;
 					}
 
-				if ($filterUser) {
+					if ($filterOutUser) {
+						return false;
+					}
+				} elseif ($restrictEnumerationPhone || $restrictEnumerationGroup) {
+					$canEnumerate = false;
+					if ($restrictEnumerationPhone) {
+						$canEnumerate = $this->knownUserService->isKnownToUser($selfUID, $entry->getProperty('UID'));
+					}
+
+					if (!$canEnumerate && $restrictEnumerationGroup) {
+						$user = $this->userManager->get($entry->getProperty('UID'));
+
+						if ($user === null) {
+							return false;
+						}
+
+						$contactGroups = $this->groupManager->getUserGroupIds($user);
+						$canEnumerate = !empty(array_intersect($contactGroups, $selfGroups));
+						$checkedCommonGroupAlready = true;
+					}
+
+					if (!$canEnumerate) {
 						return false;
 					}
 				}
 
-			if ($ownGroupsOnly && $entry->getProperty('isLocalSystemBook') === true) {
-				$uid = $this->userManager->get($entry->getProperty('UID'));
+				if ($ownGroupsOnly && !$checkedCommonGroupAlready) {
+					$user = $this->userManager->get($entry->getProperty('UID'));
 
-				if ($uid === null) {
+					if (!$user instanceof IUser) {
 						return false;
 					}
 
-				$contactGroups = $this->groupManager->getUserGroupIds($uid);
-				if (count(array_intersect($contactGroups, $selfGroups)) === 0) {
+					$contactGroups = $this->groupManager->getUserGroupIds($user);
+					if (empty(array_intersect($contactGroups, $selfGroups))) {
 						// no groups in common, so shouldn't see the contact
 						return false;
 					}
 				}
+			}
 
-			return $entry->getProperty('UID') !== $selfUID;
+			return true;
 		}));
 	}
 

lib/private/KnownUser/KnownUser.php

@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2021 Joas Schilling <coding@schilljs.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\KnownUser;
+
+use OCP\AppFramework\Db\Entity;
+
+/**
+ * @method void setKnownTo(string $knownTo)
+ * @method string getKnownTo()
+ * @method void setKnownUser(string $knownUser)
+ * @method string getKnownUser()
+ */
+class KnownUser extends Entity {
+
+	/** @var string */
+	protected $knownTo;
+
+	/** @var string */
+	protected $knownUser;
+
+	public function __construct() {
+		$this->addType('knownTo', 'string');
+		$this->addType('knownUser', 'string');
+	}
+}

lib/private/KnownUser/KnownUserMapper.php

@@ -0,0 +1,87 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2021 Joas Schilling <coding@schilljs.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\KnownUser;
+
+use OCP\AppFramework\Db\QBMapper;
+use OCP\IDBConnection;
+
+/**
+ * @method KnownUser mapRowToEntity(array $row)
+ */
+class KnownUserMapper extends QBMapper {
+
+	/**
+	 * @param IDBConnection $db
+	 */
+	public function __construct(IDBConnection $db) {
+		parent::__construct($db, 'known_users', KnownUser::class);
+	}
+
+	/**
+	 * @param string $knownTo
+	 * @return int Number of deleted entities
+	 */
+	public function deleteKnownTo(string $knownTo): int {
+		$query = $this->db->getQueryBuilder();
+		$query->delete($this->getTableName())
+			->where($query->expr()->eq('known_to', $query->createNamedParameter($knownTo)));
+
+		return (int) $query->execute();
+	}
+
+	/**
+	 * @param string $knownUser
+	 * @return int Number of deleted entities
+	 */
+	public function deleteKnownUser(string $knownUser): int {
+		$query = $this->db->getQueryBuilder();
+		$query->delete($this->getTableName())
+			->where($query->expr()->eq('known_user', $query->createNamedParameter($knownUser)));
+
+		return (int) $query->execute();
+	}
+
+	/**
+	 * Returns all "known users" for the given "known to" user
+	 *
+	 * @param string $knownTo
+	 * @return KnownUser[]
+	 */
+	public function getKnownUsers(string $knownTo): array {
+		$query = $this->db->getQueryBuilder();
+		$query->select('*')
+			->from($this->getTableName())
+			->where($query->expr()->eq('known_to', $query->createNamedParameter($knownTo)));
+
+		return $this->findEntities($query);
+	}
+
+	public function createKnownUserFromRow(array $row): KnownUser {
+		return $this->mapRowToEntity([
+			'id' => $row['s_id'],
+			'known_to' => $row['known_to'],
+			'known_user' => $row['known_user'],
+		]);
+	}
+}

lib/private/KnownUser/KnownUserService.php

@@ -0,0 +1,87 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2021 Joas Schilling <coding@schilljs.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\KnownUser;
+
+class KnownUserService {
+	/** @var KnownUserMapper */
+	protected $mapper;
+	/** @var array */
+	protected $knownUsers = [];
+
+	public function __construct(KnownUserMapper $mapper) {
+		$this->mapper = $mapper;
+	}
+
+	/**
+	 * Delete all matches where the given user is the owner of the phonebook
+	 *
+	 * @param string $knownTo
+	 * @return int Number of deleted matches
+	 */
+	public function deleteKnownTo(string $knownTo): int {
+		return $this->mapper->deleteKnownTo($knownTo);
+	}
+
+	/**
+	 * Delete all matches where the given user is the one in the phonebook
+	 *
+	 * @param string $contactUserId
+	 * @return int Number of deleted matches
+	 */
+	public function deleteByContactUserId(string $contactUserId): int {
+		return $this->mapper->deleteKnownUser($contactUserId);
+	}
+
+	/**
+	 * Store a match because $knownTo has $contactUserId in his phonebook
+	 *
+	 * @param string $knownTo User id of the owner of the phonebook
+	 * @param string $contactUserId User id of the contact in the phonebook
+	 */
+	public function storeIsKnownToUser(string $knownTo, string $contactUserId): void {
+		$entity = new KnownUser();
+		$entity->setKnownTo($knownTo);
+		$entity->setKnownUser($contactUserId);
+		$this->mapper->insert($entity);
+	}
+
+	/**
+	 * Check if $contactUserId is in the phonebook of $knownTo
+	 *
+	 * @param string $knownTo User id of the owner of the phonebook
+	 * @param string $contactUserId User id of the contact in the phonebook
+	 * @return bool
+	 */
+	public function isKnownToUser(string $knownTo, string $contactUserId): bool {
+		if (!isset($this->knownUsers[$knownTo])) {
+			$entities = $this->mapper->getKnownUsers($knownTo);
+			$this->knownUsers[$knownTo] = [];
+			foreach ($entities as $entity) {
+				$this->knownUsers[$knownTo][$entity->getKnownUser()] = true;
+			}
+		}
+
+		return isset($this->knownUsers[$knownTo][$contactUserId]);
+	}
+}

lib/private/Share20/Manager.php

@@ -1822,6 +1822,15 @@ class Manager implements IManager {
 			$this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_to_group', 'no') === 'yes';
 	}
 
+	public function limitEnumerationToPhone(): bool {
+		return $this->allowEnumeration() &&
+			$this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_to_phone', 'no') === 'yes';
+	}
+
+	public function allowEnumerationFullMatch(): bool {
+		return $this->config->getAppValue('core', 'shareapi_restrict_user_enumeration_full_match', 'yes') === 'yes';
+	}
+
 	/**
 	 * Copied from \OC_Util::isSharingDisabledForUser
 	 *

lib/public/Share/IManager.php

@@ -384,6 +384,22 @@ interface IManager {
 	 */
 	public function limitEnumerationToGroups(): bool;
 
+	/**
+	 * Check if user enumeration is limited to the phonebook matches
+	 *
+	 * @return bool
+	 * @since 21.0.1
+	 */
+	public function limitEnumerationToPhone(): bool;
+
+	/**
+	 * Check if user enumeration is allowed to return on full match
+	 *
+	 * @return bool
+	 * @since 21.0.1
+	 */
+	public function allowEnumerationFullMatch(): bool;
+
 	/**
 	 * Check if sharing is disabled for the given user
 	 *

tests/acceptance/features/bootstrap/SettingsContext.php

@@ -71,16 +71,16 @@ class SettingsContext implements Context, ActorAwareInterface {
 		// forThe()->checkbox("Restrict username...") can not be used here; that
 		// would return the checkbox itself, but the element that the user
 		// interacts with is the label.
-		return Locator::forThe()->xpath("//label[normalize-space() = 'Restrict username autocompletion to users within the same groups']")->
-				describedAs("Restrict username autocompletion to groups checkbox in Sharing section in Administration Sharing Settings");
+		return Locator::forThe()->xpath("//label[normalize-space() = 'Allow username autocompletion to users within the same groups']")->
+				describedAs("Allow username autocompletion to users within the same groups checkbox in Sharing section in Administration Sharing Settings");
 	}
 
 	/**
 	 * @return Locator
 	 */
 	public static function restrictUsernameAutocompletionToGroupsCheckboxInput() {
-		return Locator::forThe()->checkbox("Restrict username autocompletion to users within the same groups")->
-				describedAs("Restrict username autocompletion to groups checkbox input in Sharing section in Administration Sharing Settings");
+		return Locator::forThe()->checkbox("Allow username autocompletion to users within the same groups")->
+				describedAs("Allow username autocompletion to users within the same groups checkbox input in Sharing section in Administration Sharing Settings");
 	}
 
 	/**

tests/lib/Collaboration/Collaborators/MailPluginTest.php

@@ -26,6 +26,7 @@ namespace Test\Collaboration\Collaborators;
 use OC\Collaboration\Collaborators\MailPlugin;
 use OC\Collaboration\Collaborators\SearchResult;
 use OC\Federation\CloudIdManager;
+use OC\KnownUser\KnownUserService;
 use OCP\Collaboration\Collaborators\SearchResultType;
 use OCP\Contacts\IManager;
 use OCP\Federation\ICloudIdManager;
@@ -55,6 +56,9 @@ class MailPluginTest extends TestCase {
 	/** @var  IGroupManager|\PHPUnit\Framework\MockObject\MockObject */
 	protected $groupManager;
 
+	/** @var  KnownUserService|\PHPUnit\Framework\MockObject\MockObject */
+	protected $knownUserService;
+
 	/** @var  IUserSession|\PHPUnit\Framework\MockObject\MockObject */
 	protected $userSession;
 
@@ -64,6 +68,7 @@ class MailPluginTest extends TestCase {
 		$this->config = $this->createMock(IConfig::class);
 		$this->contactsManager = $this->createMock(IManager::class);
 		$this->groupManager = $this->createMock(IGroupManager::class);
+		$this->knownUserService = $this->createMock(KnownUserService::class);
 		$this->userSession = $this->createMock(IUserSession::class);
 		$this->cloudIdManager = new CloudIdManager($this->contactsManager);
 
@@ -71,7 +76,14 @@ class MailPluginTest extends TestCase {
 	}
 
 	public function instantiatePlugin() {
-		$this->plugin = new MailPlugin($this->contactsManager, $this->cloudIdManager, $this->config, $this->groupManager, $this->userSession);
+		$this->plugin = new MailPlugin(
+			$this->contactsManager,
+			$this->cloudIdManager,
+			$this->config,
+			$this->groupManager,
+			$this->knownUserService,
+			$this->userSession
+		);
 	}
 
 	/**

tests/lib/Collaboration/Collaborators/UserPluginTest.php

@@ -25,6 +25,7 @@ namespace Test\Collaboration\Collaborators;
 
 use OC\Collaboration\Collaborators\SearchResult;
 use OC\Collaboration\Collaborators\UserPlugin;
+use OC\KnownUser\KnownUserService;
 use OCP\Collaboration\Collaborators\ISearchResult;
 use OCP\IConfig;
 use OCP\IGroup;
@@ -49,6 +50,9 @@ class UserPluginTest extends TestCase {
 	/** @var  IUserSession|\PHPUnit\Framework\MockObject\MockObject */
 	protected $session;
 
+	/** @var  KnownUserService|\PHPUnit\Framework\MockObject\MockObject */
+	protected $knownUserService;
+
 	/** @var IUserStatusManager|\PHPUnit\Framework\MockObject\MockObject */
 	protected $userStatusManager;
 
@@ -78,6 +82,8 @@ class UserPluginTest extends TestCase {
 
 		$this->session = $this->createMock(IUserSession::class);
 
+		$this->knownUserService = $this->createMock(KnownUserService::class);
+
 		$this->userStatusManager = $this->createMock(IUserStatusManager::class);
 
 		$this->searchResult = new SearchResult();
@@ -93,6 +99,7 @@ class UserPluginTest extends TestCase {
 			$this->userManager,
 			$this->groupManager,
 			$this->session,
+			$this->knownUserService,
 			$this->userStatusManager
 		);
 	}

tests/lib/Contacts/ContactsMenu/ContactsStoreTest.php

@@ -26,11 +26,13 @@
 namespace Tests\Contacts\ContactsMenu;
 
 use OC\Contacts\ContactsMenu\ContactsStore;
+use OC\KnownUser\KnownUserService;
 use OCP\Contacts\IManager;
 use OCP\IConfig;
 use OCP\IGroupManager;
 use OCP\IUser;
 use OCP\IUserManager;
+use PHPUnit\Framework\MockObject\MockObject;
 use Test\TestCase;
 
 class ContactsStoreTest extends TestCase {
@@ -44,6 +46,8 @@ class ContactsStoreTest extends TestCase {
 	private $groupManager;
 	/** @var IConfig|\PHPUnit\Framework\MockObject\MockObject */
 	private $config;
+	/** @var KnownUserService|MockObject */
+	private $knownUserService;
 
 	protected function setUp(): void {
 		parent::setUp();
@@ -52,7 +56,14 @@ class ContactsStoreTest extends TestCase {
 		$this->userManager = $this->createMock(IUserManager::class);
 		$this->groupManager = $this->createMock(IGroupManager::class);
 		$this->config = $this->createMock(IConfig::class);
-		$this->contactsStore = new ContactsStore($this->contactsManager, $this->config, $this->userManager, $this->groupManager);
+		$this->knownUserService = $this->createMock(KnownUserService::class);
+		$this->contactsStore = new ContactsStore(
+			$this->contactsManager,
+			$this->config,
+			$this->userManager,
+			$this->groupManager,
+			$this->knownUserService
+		);
 	}
 
 	public function testGetContactsWithoutFilter() {
@@ -171,29 +182,16 @@ class ContactsStoreTest extends TestCase {
 	}
 
 	public function testGetContactsWhenUserIsInExcludeGroups() {
-		$this->config->expects($this->at(0))->method('getAppValue')
-			->with($this->equalTo('core'), $this->equalTo('shareapi_allow_share_dialog_user_enumeration'), $this->equalTo('yes'))
-			->willReturn('yes');
-
-		$this->config->expects($this->at(1))
+		$this->config
 			->method('getAppValue')
-			->with($this->equalTo('core'), $this->equalTo('shareapi_restrict_user_enumeration_to_group'), $this->equalTo('no'))
-			->willReturn('no');
-
-		$this->config->expects($this->at(2))
-			->method('getAppValue')
-			->with($this->equalTo('core'), $this->equalTo('shareapi_exclude_groups'), $this->equalTo('no'))
-			->willReturn('yes');
-
-		$this->config->expects($this->at(3))
-			->method('getAppValue')
-			->with($this->equalTo('core'), $this->equalTo('shareapi_only_share_with_group_members'), $this->equalTo('no'))
-			->willReturn('yes');
-
-		$this->config->expects($this->at(4))
-			->method('getAppValue')
-			->with($this->equalTo('core'), $this->equalTo('shareapi_exclude_groups_list'), $this->equalTo(''))
-			->willReturn('["group1", "group5", "group6"]');
+			->willReturnMap([
+				['core', 'shareapi_allow_share_dialog_user_enumeration', 'yes', 'yes'],
+				['core', 'shareapi_restrict_user_enumeration_to_group', 'no', 'no'],
+				['core', 'shareapi_restrict_user_enumeration_to_phone', 'no', 'no'],
+				['core', 'shareapi_exclude_groups', 'no', 'yes'],
+				['core', 'shareapi_only_share_with_group_members', 'no', 'yes'],
+				['core', 'shareapi_exclude_groups_list', '', '["group1", "group5", "group6"]'],
+			]);
 
 		/** @var IUser|\PHPUnit\Framework\MockObject\MockObject $currentUser */
 		$currentUser = $this->createMock(IUser::class);
@@ -228,22 +226,15 @@ class ContactsStoreTest extends TestCase {
 	}
 
 	public function testGetContactsOnlyShareIfInTheSameGroup() {
-		$this->config->expects($this->at(0))->method('getAppValue')
-			->with($this->equalTo('core'), $this->equalTo('shareapi_allow_share_dialog_user_enumeration'), $this->equalTo('yes'))
-			->willReturn('yes');
-
-		$this->config->expects($this->at(1)) ->method('getAppValue')
-			->with($this->equalTo('core'), $this->equalTo('shareapi_restrict_user_enumeration_to_group'), $this->equalTo('no'))
-			->willReturn('no');
-
-		$this->config->expects($this->at(2)) ->method('getAppValue')
-			->with($this->equalTo('core'), $this->equalTo('shareapi_exclude_groups'), $this->equalTo('no'))
-			->willReturn('no');
-
-		$this->config->expects($this->at(3))
+		$this->config
 			->method('getAppValue')
-			->with($this->equalTo('core'), $this->equalTo('shareapi_only_share_with_group_members'), $this->equalTo('no'))
-			->willReturn('yes');
+			->willReturnMap([
+				['core', 'shareapi_allow_share_dialog_user_enumeration', 'yes', 'yes'],
+				['core', 'shareapi_restrict_user_enumeration_to_group', 'no', 'no'],
+				['core', 'shareapi_restrict_user_enumeration_to_phone', 'no', 'no'],
+				['core', 'shareapi_exclude_groups', 'no', 'no'],
+				['core', 'shareapi_only_share_with_group_members', 'no', 'yes'],
+			]);
 
 		/** @var IUser|\PHPUnit\Framework\MockObject\MockObject $currentUser */
 		$currentUser = $this->createMock(IUser::class);
@@ -314,22 +305,15 @@ class ContactsStoreTest extends TestCase {
 	}
 
 	public function testGetContactsOnlyEnumerateIfInTheSameGroup() {
-		$this->config->expects($this->at(0))->method('getAppValue')
-			->with($this->equalTo('core'), $this->equalTo('shareapi_allow_share_dialog_user_enumeration'), $this->equalTo('yes'))
-			->willReturn('yes');
-
-		$this->config->expects($this->at(1)) ->method('getAppValue')
-			->with($this->equalTo('core'), $this->equalTo('shareapi_restrict_user_enumeration_to_group'), $this->equalTo('no'))
-			->willReturn('yes');
-
-		$this->config->expects($this->at(2)) ->method('getAppValue')
-			->with($this->equalTo('core'), $this->equalTo('shareapi_exclude_groups'), $this->equalTo('no'))
-			->willReturn('no');
-
-		$this->config->expects($this->at(3))
+		$this->config
 			->method('getAppValue')
-			->with($this->equalTo('core'), $this->equalTo('shareapi_only_share_with_group_members'), $this->equalTo('no'))
-			->willReturn('no');
+			->willReturnMap([
+				['core', 'shareapi_allow_share_dialog_user_enumeration', 'yes', 'yes'],
+				['core', 'shareapi_restrict_user_enumeration_to_group', 'no', 'yes'],
+				['core', 'shareapi_restrict_user_enumeration_to_phone', 'no', 'no'],
+				['core', 'shareapi_exclude_groups', 'no', 'no'],
+				['core', 'shareapi_only_share_with_group_members', 'no', 'yes'],
+			]);
 
 		/** @var IUser|\PHPUnit\Framework\MockObject\MockObject $currentUser */
 		$currentUser = $this->createMock(IUser::class);
@@ -399,10 +383,312 @@ class ContactsStoreTest extends TestCase {
 		$this->assertEquals('contact', $entries[2]->getProperty('UID'));
 	}
 
+	public function testGetContactsOnlyEnumerateIfPhoneBookMatch() {
+		$this->config
+			->method('getAppValue')
+			->willReturnMap([
+				['core', 'shareapi_allow_share_dialog_user_enumeration', 'yes', 'yes'],
+				['core', 'shareapi_restrict_user_enumeration_to_group', 'no', 'no'],
+				['core', 'shareapi_restrict_user_enumeration_to_phone', 'no', 'yes'],
+				['core', 'shareapi_exclude_groups', 'no', 'no'],
+				['core', 'shareapi_only_share_with_group_members', 'no', 'no'],
+			]);
+
+		/** @var IUser|\PHPUnit\Framework\MockObject\MockObject $currentUser */
+		$currentUser = $this->createMock(IUser::class);
+		$currentUser->expects($this->once())
+			->method('getUID')
+			->willReturn('user001');
+
+		$this->groupManager->expects($this->at(0))
+			->method('getUserGroupIds')
+			->with($this->equalTo($currentUser))
+			->willReturn(['group1', 'group2', 'group3']);
+
+		$this->knownUserService->method('isKnownToUser')
+			->willReturnMap([
+				['user001', 'user1', true],
+				['user001', 'user2', true],
+				['user001', 'user3', false],
+			]);
+
+		$this->contactsManager->expects($this->once())
+			->method('search')
+			->with($this->equalTo(''), $this->equalTo(['FN', 'EMAIL']))
+			->willReturn([
+				[
+					'UID' => 'user1',
+					'isLocalSystemBook' => true
+				],
+				[
+					'UID' => 'user2',
+					'isLocalSystemBook' => true
+				],
+				[
+					'UID' => 'user3',
+					'isLocalSystemBook' => true
+				],
+				[
+					'UID' => 'contact',
+				],
+			]);
+
+		$entries = $this->contactsStore->getContacts($currentUser, '');
+
+		$this->assertCount(3, $entries);
+		$this->assertEquals('user1', $entries[0]->getProperty('UID'));
+		$this->assertEquals('user2', $entries[1]->getProperty('UID'));
+		$this->assertEquals('contact', $entries[2]->getProperty('UID'));
+	}
+
+	public function testGetContactsOnlyEnumerateIfPhoneBookMatchWithOwnGroupsOnly() {
+		$this->config
+			->method('getAppValue')
+			->willReturnMap([
+				['core', 'shareapi_allow_share_dialog_user_enumeration', 'yes', 'yes'],
+				['core', 'shareapi_restrict_user_enumeration_to_group', 'no', 'no'],
+				['core', 'shareapi_restrict_user_enumeration_to_phone', 'no', 'yes'],
+				['core', 'shareapi_exclude_groups', 'no', 'no'],
+				['core', 'shareapi_only_share_with_group_members', 'no', 'yes'],
+			]);
+
+		/** @var IUser|\PHPUnit\Framework\MockObject\MockObject $currentUser */
+		$currentUser = $this->createMock(IUser::class);
+		$currentUser->expects($this->once())
+			->method('getUID')
+			->willReturn('user001');
+
+		$this->groupManager->expects($this->at(0))
+			->method('getUserGroupIds')
+			->with($this->equalTo($currentUser))
+			->willReturn(['group1', 'group2', 'group3']);
+
+		$user1 = $this->createMock(IUser::class);
+		$this->userManager->expects($this->at(0))
+			->method('get')
+			->with('user1')
+			->willReturn($user1);
+		$this->groupManager->expects($this->at(1))
+			->method('getUserGroupIds')
+			->with($this->equalTo($user1))
+			->willReturn(['group1']);
+		$user2 = $this->createMock(IUser::class);
+		$this->userManager->expects($this->at(1))
+			->method('get')
+			->with('user2')
+			->willReturn($user2);
+		$this->groupManager->expects($this->at(2))
+			->method('getUserGroupIds')
+			->with($this->equalTo($user2))
+			->willReturn(['group2', 'group3']);
+		$user3 = $this->createMock(IUser::class);
+		$this->userManager->expects($this->at(2))
+			->method('get')
+			->with('user3')
+			->willReturn($user3);
+		$this->groupManager->expects($this->at(3))
+			->method('getUserGroupIds')
+			->with($this->equalTo($user3))
+			->willReturn(['group8', 'group9']);
+
+		$this->knownUserService->method('isKnownToUser')
+			->willReturnMap([
+				['user001', 'user1', true],
+				['user001', 'user2', true],
+				['user001', 'user3', true],
+			]);
+
+		$this->contactsManager->expects($this->once())
+			->method('search')
+			->with($this->equalTo(''), $this->equalTo(['FN', 'EMAIL']))
+			->willReturn([
+				[
+					'UID' => 'user1',
+					'isLocalSystemBook' => true
+				],
+				[
+					'UID' => 'user2',
+					'isLocalSystemBook' => true
+				],
+				[
+					'UID' => 'user3',
+					'isLocalSystemBook' => true
+				],
+				[
+					'UID' => 'contact',
+				],
+			]);
+
+		$entries = $this->contactsStore->getContacts($currentUser, '');
+
+		$this->assertCount(3, $entries);
+		$this->assertEquals('user1', $entries[0]->getProperty('UID'));
+		$this->assertEquals('user2', $entries[1]->getProperty('UID'));
+		$this->assertEquals('contact', $entries[2]->getProperty('UID'));
+	}
+
+	public function testGetContactsOnlyEnumerateIfPhoneBookOrSameGroup() {
+		$this->config
+			->method('getAppValue')
+			->willReturnMap([
+				['core', 'shareapi_allow_share_dialog_user_enumeration', 'yes', 'yes'],
+				['core', 'shareapi_restrict_user_enumeration_to_group', 'no', 'yes'],
+				['core', 'shareapi_restrict_user_enumeration_to_phone', 'no', 'yes'],
+				['core', 'shareapi_exclude_groups', 'no', 'no'],
+				['core', 'shareapi_only_share_with_group_members', 'no', 'no'],
+			]);
+
+		/** @var IUser|\PHPUnit\Framework\MockObject\MockObject $currentUser */
+		$currentUser = $this->createMock(IUser::class);
+		$currentUser->expects($this->once())
+			->method('getUID')
+			->willReturn('user001');
+
+		$this->groupManager->expects($this->at(0))
+			->method('getUserGroupIds')
+			->with($this->equalTo($currentUser))
+			->willReturn(['group1', 'group2', 'group3']);
+
+		$user1 = $this->createMock(IUser::class);
+		$this->userManager->expects($this->at(0))
+			->method('get')
+			->with('user1')
+			->willReturn($user1);
+		$this->groupManager->expects($this->at(1))
+			->method('getUserGroupIds')
+			->with($this->equalTo($user1))
+			->willReturn(['group1']);
+
+		$this->knownUserService->method('isKnownToUser')
+			->willReturnMap([
+				['user001', 'user1', false],
+				['user001', 'user2', true],
+				['user001', 'user3', true],
+			]);
+
+		$this->contactsManager->expects($this->once())
+			->method('search')
+			->with($this->equalTo(''), $this->equalTo(['FN', 'EMAIL']))
+			->willReturn([
+				[
+					'UID' => 'user1',
+					'isLocalSystemBook' => true
+				],
+				[
+					'UID' => 'user2',
+					'isLocalSystemBook' => true
+				],
+				[
+					'UID' => 'user3',
+					'isLocalSystemBook' => true
+				],
+				[
+					'UID' => 'contact',
+				],
+			]);
+
+		$entries = $this->contactsStore->getContacts($currentUser, '');
+
+		$this->assertCount(4, $entries);
+		$this->assertEquals('user1', $entries[0]->getProperty('UID'));
+		$this->assertEquals('user2', $entries[1]->getProperty('UID'));
+		$this->assertEquals('user3', $entries[2]->getProperty('UID'));
+		$this->assertEquals('contact', $entries[3]->getProperty('UID'));
+	}
+
+	public function testGetContactsOnlyEnumerateIfPhoneBookOrSameGroupInOwnGroupsOnly() {
+		$this->config
+			->method('getAppValue')
+			->willReturnMap([
+				['core', 'shareapi_allow_share_dialog_user_enumeration', 'yes', 'yes'],
+				['core', 'shareapi_restrict_user_enumeration_to_group', 'no', 'yes'],
+				['core', 'shareapi_restrict_user_enumeration_to_phone', 'no', 'yes'],
+				['core', 'shareapi_exclude_groups', 'no', 'no'],
+				['core', 'shareapi_only_share_with_group_members', 'no', 'yes'],
+			]);
+
+		/** @var IUser|\PHPUnit\Framework\MockObject\MockObject $currentUser */
+		$currentUser = $this->createMock(IUser::class);
+		$currentUser->expects($this->once())
+			->method('getUID')
+			->willReturn('user001');
+
+		$this->groupManager->expects($this->at(0))
+			->method('getUserGroupIds')
+			->with($this->equalTo($currentUser))
+			->willReturn(['group1', 'group2', 'group3']);
+
+		$user1 = $this->createMock(IUser::class);
+		$this->userManager->expects($this->at(0))
+			->method('get')
+			->with('user1')
+			->willReturn($user1);
+		$this->groupManager->expects($this->at(1))
+			->method('getUserGroupIds')
+			->with($this->equalTo($user1))
+			->willReturn(['group1']);
+		$user2 = $this->createMock(IUser::class);
+		$this->userManager->expects($this->at(1))
+			->method('get')
+			->with('user2')
+			->willReturn($user2);
+		$this->groupManager->expects($this->at(2))
+			->method('getUserGroupIds')
+			->with($this->equalTo($user2))
+			->willReturn(['group2', 'group3']);
+		$user3 = $this->createMock(IUser::class);
+		$this->userManager->expects($this->at(2))
+			->method('get')
+			->with('user3')
+			->willReturn($user3);
+		$this->groupManager->expects($this->at(3))
+			->method('getUserGroupIds')
+			->with($this->equalTo($user3))
+			->willReturn(['group8', 'group9']);
+
+		$this->knownUserService->method('isKnownToUser')
+			->willReturnMap([
+				['user001', 'user1', false],
+				['user001', 'user2', true],
+				['user001', 'user3', true],
+			]);
+
+		$this->contactsManager->expects($this->once())
+			->method('search')
+			->with($this->equalTo(''), $this->equalTo(['FN', 'EMAIL']))
+			->willReturn([
+				[
+					'UID' => 'user1',
+					'isLocalSystemBook' => true
+				],
+				[
+					'UID' => 'user2',
+					'isLocalSystemBook' => true
+				],
+				[
+					'UID' => 'user3',
+					'isLocalSystemBook' => true
+				],
+				[
+					'UID' => 'contact',
+				],
+			]);
+
+		$entries = $this->contactsStore->getContacts($currentUser, '');
+
+		$this->assertCount(3, $entries);
+		$this->assertEquals('user1', $entries[0]->getProperty('UID'));
+		$this->assertEquals('user2', $entries[1]->getProperty('UID'));
+		$this->assertEquals('contact', $entries[2]->getProperty('UID'));
+	}
+
 	public function testGetContactsWithFilter() {
-		$this->config->expects($this->at(0))->method('getAppValue')
-			->with($this->equalTo('core'), $this->equalTo('shareapi_allow_share_dialog_user_enumeration'), $this->equalTo('yes'))
-			->willReturn('no');
+		$this->config
+			->method('getAppValue')
+			->willReturnMap([
+				['core', 'shareapi_allow_share_dialog_user_enumeration', 'yes', 'no'],
+				['core', 'shareapi_restrict_user_enumeration_full_match', 'yes', 'yes'],
+			]);
 
 		/** @var IUser|\PHPUnit\Framework\MockObject\MockObject $user */
 		$user = $this->createMock(IUser::class);
@@ -483,6 +769,90 @@ class ContactsStoreTest extends TestCase {
 		], $entry[0]->getEMailAddresses());
 	}
 
+	public function testGetContactsWithFilterWithoutFullMatch() {
+		$this->config
+			->method('getAppValue')
+			->willReturnMap([
+				['core', 'shareapi_allow_share_dialog_user_enumeration', 'yes', 'no'],
+				['core', 'shareapi_restrict_user_enumeration_full_match', 'yes', 'no'],
+			]);
+
+		/** @var IUser|\PHPUnit\Framework\MockObject\MockObject $user */
+		$user = $this->createMock(IUser::class);
+		$this->contactsManager->expects($this->any())
+			->method('search')
+			->willReturn([
+				[
+					'UID' => 'a567',
+					'FN' => 'Darren Roner',
+					'EMAIL' => [
+						'darren@roner.au',
+					],
+					'isLocalSystemBook' => true,
+				],
+				[
+					'UID' => 'john',
+					'FN' => 'John Doe',
+					'EMAIL' => [
+						'john@example.com',
+					],
+					'isLocalSystemBook' => true,
+				],
+				[
+					'FN' => 'Anne D',
+					'EMAIL' => [
+						'anne@example.com',
+					],
+					'isLocalSystemBook' => false,
+				],
+			]);
+		$user->expects($this->any())
+			->method('getUID')
+			->willReturn('user123');
+
+		// Complete match on UID should not match
+		$entry = $this->contactsStore->getContacts($user, 'a567');
+		$this->assertSame(1, count($entry));
+		$this->assertEquals([
+			'anne@example.com'
+		], $entry[0]->getEMailAddresses());
+
+		// Partial match on UID should not match
+		$entry = $this->contactsStore->getContacts($user, 'a56');
+		$this->assertSame(1, count($entry));
+		$this->assertEquals([
+			'anne@example.com'
+		], $entry[0]->getEMailAddresses());
+
+		// Complete match on email should not match
+		$entry = $this->contactsStore->getContacts($user, 'john@example.com');
+		$this->assertSame(1, count($entry));
+		$this->assertEquals([
+			'anne@example.com'
+		], $entry[0]->getEMailAddresses());
+
+		// Partial match on email should not match
+		$entry = $this->contactsStore->getContacts($user, 'john@example.co');
+		$this->assertSame(1, count($entry));
+		$this->assertEquals([
+			'anne@example.com'
+		], $entry[0]->getEMailAddresses());
+
+		// Match on FN should not match
+		$entry = $this->contactsStore->getContacts($user, 'Darren Roner');
+		$this->assertSame(1, count($entry));
+		$this->assertEquals([
+			'anne@example.com'
+		], $entry[0]->getEMailAddresses());
+
+		// Don't filter users in local addressbook
+		$entry = $this->contactsStore->getContacts($user, 'Anne D');
+		$this->assertSame(1, count($entry));
+		$this->assertEquals([
+			'anne@example.com'
+		], $entry[0]->getEMailAddresses());
+	}
+
 	public function testFindOneUser() {
 		$this->config->expects($this->at(0))->method('getAppValue')
 			->with($this->equalTo('core'), $this->equalTo('shareapi_allow_share_dialog_user_enumeration'), $this->equalTo('yes'))

version.php

@@ -30,7 +30,7 @@
 // between betas, final and RCs. This is _not_ the public version number. Reset minor/patchlevel
 // when updating major/minor version number.
 
-$OC_Version = [21, 0, 0, 18];
+$OC_Version = [21, 0, 0, 19];
 
 // The human readable string
 $OC_VersionString = '21.0.0';