decrypt private key for public shares correctly

apps/encryption/lib/crypto/crypt.php

@@ -231,7 +231,7 @@ class Crypt {
 	 * @param string $password
 	 * @return bool|string
 	 */
-	public function decryptPrivateKey($privateKey, $password) {
+	public function decryptPrivateKey($privateKey, $password = '') {
 
 		$header = $this->parseHeader($privateKey);
 
@@ -273,7 +273,7 @@ class Crypt {
 	 * @return string
 	 * @throws DecryptionFailedException
 	 */
-	public function symmetricDecryptFileContent($keyFileContents, $passPhrase = '', $cipher = self::DEFAULT_CIPHER) {
+	public function symmetricDecryptFileContent($keyFileContents, $passPhrase, $cipher = self::DEFAULT_CIPHER) {
 		// Remove Padding
 		$noPadding = $this->removePadding($keyFileContents);
 

apps/encryption/lib/keymanager.php

@@ -337,7 +337,7 @@ class KeyManager {
 			$uid = $this->getPublicShareKeyId();
 			$shareKey = $this->getShareKey($path, $uid);
 			$privateKey = $this->keyStorage->getSystemUserKey($this->publicShareKeyId . '.privateKey');
-			$privateKey = $this->crypt->symmetricDecryptFileContent($privateKey);
+			$privateKey = $this->crypt->decryptPrivateKey($privateKey);
 		} else {
 			$shareKey = $this->getShareKey($path, $uid);
 			$privateKey = $this->session->getPrivateKey();

apps/encryption/tests/lib/KeyManagerTest.php

@@ -268,7 +268,7 @@ class KeyManagerTest extends TestCase {
 			->willReturn(true);
 
 		$this->cryptMock->expects($this->once())
-			->method('symmetricDecryptFileContent')
+			->method('decryptPrivateKey')
 			->willReturn(true);
 
 		$this->cryptMock->expects($this->once())