Updated cookie encryption/decryption to use openssl instead of mcrypt…

… where supported.
StartupAPI · Nov 20, 2017 · c2f9ab2 · c2f9ab2
1 parent 8ff38f4
commit c2f9ab2
Showing 1 changed file with 46 additions and 7 deletions.
diff --git a/classes/CookieStorage.php b/classes/CookieStorage.php
@@ -65,12 +65,36 @@ public static function padkey($key, $bits = 256)
         return $newkey;
     }
 
+    public static function getOpenSSLCipher() {
+      $ciphers = array_intersect(array(
+        'AES-256-CTR',
+        'AES-256-CFB',
+        'AES-128-CFB',
+      ), openssl_get_cipher_methods());
+
+      if (empty($ciphers)) {
+        throw new Exception('No usable ciphers available');
+      }
+
+      return array_shift($ciphers);
+    }
+
     public static function encrypt($key, $str)
     {
-        $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
+        if (function_exists('openssl_encrypt')) {
-        $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
+          $cipher = self::getOpenSSLCipher();
-        $data = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, self::padkey($key, 256), $str, MCRYPT_MODE_ECB, $iv);
+          $iv_len = openssl_cipher_iv_length($cipher);
-        return base64_encode($data);
+          $iv = openssl_random_pseudo_bytes($iv_len);
+          $data = openssl_encrypt($str, $cipher, $key, $options=OPENSSL_RAW_DATA, $iv);
+          $hmac = hash_hmac('sha256', $data, $key, $as_binary=true);
+          return base64_encode($iv.$hmac.$data);
+        } else {
+          $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
+          $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
+          $data = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, self::padkey($key, 256), $str, MCRYPT_MODE_ECB, $iv);
+          return base64_encode($data);
+        }
+
     }
 
     public static function decrypt($key, $data)
@@ -79,9 +103,24 @@ public static function decrypt($key, $data)
             return false;
         }
 
-        $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
+        if (function_exists('openssl_encrypt')) {
-        $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
+          $cipher = self::getOpenSSLCipher();
-        return mcrypt_decrypt(MCRYPT_RIJNDAEL_256, self::padkey($key, 256), $data, MCRYPT_MODE_ECB, $iv);
+          $iv_len = openssl_cipher_iv_length($cipher);
+          $iv = substr($data, 0, $iv_len);
+          $hmac = substr($data, $iv_len, $sha2len=32);
+          $ciphertext_raw = substr($data, $iv_len+$sha2len);
+          $original_plaintext = openssl_decrypt($ciphertext_raw, $cipher, $key, $options=OPENSSL_RAW_DATA, $iv);
+          $calcmac = hash_hmac('sha256', $ciphertext_raw, $key, $as_binary=true);
+          if (hash_equals($hmac, $calcmac)) {
+            return $original_plaintext;
+          } else {
+            return null;
+          }
+        } else {
+          $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
+          $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
+          return mcrypt_decrypt(MCRYPT_RIJNDAEL_256, self::padkey($key, 256), $data, MCRYPT_MODE_ECB, $iv);
+        }
     }
 
     public function getDefaults()