Using sarciszewski/php-future for polyfill in PHP < 5.6

composer.json

@@ -20,8 +20,9 @@
         }
     ],
     "require": {
-        "php": ">=5.3.0",
-        "ext-mcrypt": "*"
+        "php": ">=5.4.0",
+        "ext-mcrypt": "*",
+		"sarciszewski/php-future": "0.4.*"
     },
     "require-dev": {
 		"rncryptor/spec": "3.0.1",

lib/bootstrap.php

@@ -2,53 +2,3 @@
 
 require dirname(__FILE__) . '/RNCryptor/Autoloader.php';
 RNCryptor_Autoloader::register();
-
-if (!function_exists('hash_pbkdf2')) {
-
-	/**
-	 * Based on pbkdf2() from https://defuse.ca/php-pbkdf2.htm. Made signature-compatible with hash_pbkdf2() in PHP5.5
-	 *
-	 * PBKDF2 key derivation function as defined by RSA's PKCS #5: https://www.ietf.org/rfc/rfc2898.txt
-	 * $algorithm - The hash algorithm to use. Recommended: SHA256
-	 * $password - The password.
-	 * $salt - A salt that is unique to the password.
-	 * $count - Iteration count. Higher is better, but slower. Recommended: At least 1000.
-	 * $key_length - The length of the derived key in bytes.
-	 * $raw_output - If true, the key is returned in raw binary format. Hex encoded otherwise.
-	 * Returns: A $key_length-byte key derived from the password and salt.
-	 *
-	 * Test vectors can be found here: https://www.ietf.org/rfc/rfc6070.txt
-	 *
-	 * This implementation of PBKDF2 was originally created by https://defuse.ca
-	 * With improvements by http://www.variations-of-shadow.com
-	 */
-	function hash_pbkdf2($algorithm, $password, $salt, $count, $key_length = 0, $raw_output = false)
-	{
-		$algorithm = strtolower($algorithm);
-		if(!in_array($algorithm, hash_algos(), true))
-			die('PBKDF2 ERROR: Invalid hash algorithm.');
-		if($count <= 0 || $key_length <= 0)
-			die('PBKDF2 ERROR: Invalid parameters.');
-
-		$hash_length = strlen(hash($algorithm, "", true));
-		$block_count = ceil($key_length / $hash_length);
-
-		$output = "";
-		for($i = 1; $i <= $block_count; $i++) {
-			// $i encoded as 4 bytes, big endian.
-			$last = $salt . pack("N", $i);
-			// first iteration
-			$last = $xorsum = hash_hmac($algorithm, $last, $password, true);
-			// perform the other $count - 1 iterations
-			for ($j = 1; $j < $count; $j++) {
-				$xorsum ^= ($last = hash_hmac($algorithm, $last, $password, true));
-			}
-			$output .= $xorsum;
-		}
-
-		if($raw_output)
-			return substr($output, 0, $key_length);
-		else
-			return bin2hex(substr($output, 0, $key_length));
-	}
-}