Remember current cipher

Signed-off-by: J0WI <J0WI@users.noreply.github.com>

Author: J0WI

apps/encryption/lib/Crypto/Crypt.php

@@ -89,6 +89,9 @@ class Crypt {
 	/** @var IL10N */
 	private $l;
 
+	/** @var string */
+	private $currentCipher;
+
 	/** @var bool */
 	private $supportLegacy;
 
@@ -248,26 +251,40 @@ private function encrypt($plainContent, $iv, $passPhrase = '', $cipher = self::D
 	}
 
 	/**
-	 * return Cipher either from config.php or the default cipher defined in
+	 * return cipher either from config.php or the default cipher defined in
 	 * this class
 	 *
 	 * @return string
 	 */
-	public function getCipher() {
-		$cipher = $this->config->getSystemValue('cipher', self::DEFAULT_CIPHER);
-		if (!isset(self::SUPPORTED_CIPHERS_AND_KEY_SIZE[$cipher])) {
-			$this->logger->warning(
-				sprintf(
-					'Unsupported cipher (%s) defined in config.php supported. Falling back to %s',
-					$cipher,
-					self::DEFAULT_CIPHER
-				),
-				['app' => 'encryption']
-			);
-			$cipher = self::DEFAULT_CIPHER;
+	private function getCachedCipher() {
+		if (!isset($this->currentCipher)) {
+			// Get cipher either from config.php or the default cipher defined in this class
+			$cipher = $this->config->getSystemValue('cipher', self::DEFAULT_CIPHER);
+			if (!isset(self::SUPPORTED_CIPHERS_AND_KEY_SIZE[$cipher])) {
+				$this->logger->warning(
+					sprintf(
+						'Unsupported cipher (%s) defined in config.php supported. Falling back to %s',
+						$cipher,
+						self::DEFAULT_CIPHER
+					),
+					['app' => 'encryption']
+				);
+				$cipher = self::DEFAULT_CIPHER;
+			}
+
+			// Remember current cipher to avoid frequent lookups
+			$this->currentCipher = $cipher;
 		}
+		return $this->currentCipher;
+	}
 
-		return $cipher;
+	/**
+	 * return current encryption cipher
+	 *
+	 * @return string
+	 */
+	public function getCipher() {
+		return $this->getCachedCipher();
 	}
 
 	/**
@@ -577,7 +594,7 @@ private function hasSignature($catFile, $cipher) {
 			throw new GenericEncryptionException('Missing Signature', $this->l->t('Missing Signature'));
 		}
 
-		// enforce signature for the new 'CTR' ciphers
+		// Enforce signature for the new 'CTR' ciphers
 		if (!$skipSignatureCheck && $signaturePosition === false && stripos($cipher, 'ctr') !== false) {
 			throw new GenericEncryptionException('Missing Signature', $this->l->t('Missing Signature'));
 		}