Introduce isReadyForUser and verify in file transfer ownership - fixes #23786

3 files changed, 20 insertions, 0 deletions

diff --git a/apps/encryption/lib/crypto/encryption.php b/apps/encryption/lib/crypto/encryption.php
index 907a6437f5b..6eff66e72be 100644
--- a/apps/encryption/lib/crypto/encryption.php
+++ b/apps/encryption/lib/crypto/encryption.php
@@ -547,4 +547,17 @@ class Encryption implements IEncryptionModule {
 		return $path;
 	}
 
+	/**
+	 * Check if the module is ready to be used by that specific user.
+	 * In case a module is not ready - because e.g. key pairs have not been generated
+	 * upon login this method can return false before any operation starts and might
+	 * cause issues during operations.
+	 *
+	 * @param string $user
+	 * @return boolean
+	 * @since 9.1.0
+	 */
+	public function isReadyForUser($user) {
+		return $this->keyManager->userHasKeys($user);
+	}
 }
diff --git a/apps/encryption/lib/keymanager.php b/apps/encryption/lib/keymanager.php
index 12fa5f92bd5..0accfb7900a 100644
--- a/apps/encryption/lib/keymanager.php
+++ b/apps/encryption/lib/keymanager.php
@@ -493,6 +493,7 @@ class KeyManager {
 	 */
 	public function userHasKeys($userId) {
 		$privateKey = $publicKey = true;
+		$exception = null;
 
 		try {
 			$this->getPrivateKey($userId);
diff --git a/apps/files/command/transferownership.php b/apps/files/command/transferownership.php
index 6bf2fae6bdf..1f46efdde0d 100644
--- a/apps/files/command/transferownership.php
+++ b/apps/files/command/transferownership.php
@@ -97,6 +97,12 @@ class TransferOwnership extends Command {
 			$output->writeln("<error>Unknown destination user $this->destinationUser</error>");
 			return;
 		}
+		
+		// target user has to be ready
+		if (!\OC::$server->getEncryptionManager()->isReadyForUser($this->destinationUser)) {
+			$output->writeln("<error>The target user is not ready to accept files. The user has at least to be logged in once.</error>");
+			return;
+		}
 
 		$date = date('c');
 		$this->finalTarget = "$this->destinationUser/files/transferred from $this->sourceUser on $date";