Improve typing as suggested by review

Signed-off-by: Côme Chilliet <come.chilliet@nextcloud.com>

apps/encryption/lib/Crypto/Crypt.php

@@ -153,9 +153,6 @@ class Crypt {
 		return openssl_pkey_new($config);
 	}
 
-	/**
-	 * get openSSL Config
-	 */
 	private function getOpenSSLConfig(): array {
 		$config = ['private_key_bits' => 4096];
 		$config = array_merge(
@@ -217,13 +214,9 @@ class Crypt {
 	}
 
 	/**
-	 * @param string $plainContent
-	 * @param string $iv
-	 * @param string $passPhrase
-	 * @param string $cipher
 	 * @throws EncryptionFailedException
 	 */
-	private function encrypt($plainContent, $iv, $passPhrase = '', $cipher = self::DEFAULT_CIPHER): string {
+	private function encrypt(string $plainContent, string $iv, string $passPhrase = '', string $cipher = self::DEFAULT_CIPHER): string {
 		$options = $this->useLegacyBase64Encoding ? 0 : OPENSSL_RAW_DATA;
 		$encryptedContent = openssl_encrypt($plainContent,
 			$cipher,
@@ -311,19 +304,11 @@ class Crypt {
 		return self::LEGACY_CIPHER;
 	}
 
-	/**
-	 * @param string $encryptedContent
-	 * @param string $iv
-	 */
-	private function concatIV($encryptedContent, $iv): string {
+	private function concatIV(string $encryptedContent, string $iv): string {
 		return $encryptedContent . '00iv00' . $iv;
 	}
 
-	/**
-	 * @param string $encryptedContent
-	 * @param string $signature
-	 */
-	private function concatSig($encryptedContent, $signature): string {
+	private function concatSig(string $encryptedContent, string $signature): string {
 		return $encryptedContent . '00sig00' . $signature;
 	}
 
@@ -331,10 +316,8 @@ class Crypt {
 	 * Note: This is _NOT_ a padding used for encryption purposes. It is solely
 	 * used to achieve the PHP stream size. It has _NOTHING_ to do with the
 	 * encrypted content and is not used in any crypto primitive.
-	 *
-	 * @param string $data
 	 */
-	private function addPadding($data): string {
+	private function addPadding(string $data): string {
 		return $data . 'xxx';
 	}
 
@@ -514,12 +497,9 @@ class Crypt {
 
 
 	/**
-	 * remove padding
-	 *
-	 * @param string $padded
 	 * @param bool $hasSignature did the block contain a signature, in this case we use a different padding
 	 */
-	private function removePadding($padded, $hasSignature = false): string|false {
+	private function removePadding(string $padded, bool $hasSignature = false): string|false {
 		if ($hasSignature === false && substr($padded, -2) === 'xx') {
 			return substr($padded, 0, -2);
 		} elseif ($hasSignature === true && substr($padded, -3) === 'xxx') {
@@ -532,11 +512,8 @@ class Crypt {
 	 * split meta data from encrypted file
 	 * Note: for now, we assume that the meta data always start with the iv
 	 *       followed by the signature, if available
-	 *
-	 * @param string $catFile
-	 * @param string $cipher
 	 */
-	private function splitMetaData($catFile, $cipher): array {
+	private function splitMetaData(string $catFile, string $cipher): array {
 		if ($this->hasSignature($catFile, $cipher)) {
 			$catFile = $this->removePadding($catFile, true);
 			$meta = substr($catFile, -93);
@@ -561,11 +538,9 @@ class Crypt {
 	/**
 	 * check if encrypted block is signed
 	 *
-	 * @param string $catFile
-	 * @param string $cipher
 	 * @throws GenericEncryptionException
 	 */
-	private function hasSignature($catFile, $cipher): bool {
+	private function hasSignature(string $catFile, string $cipher): bool {
 		$skipSignatureCheck = $this->config->getSystemValueBool('encryption_skip_signature_check', false);
 
 		$meta = substr($catFile, -93);