Initial Upload

lib/Helper/Pbkdf2Hash.php

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+<?php
+/*
+ * Spring Signage Ltd - http://www.springsignage.com
+ * Copyright (C) 2016 Spring Signage Ltd
+ * (PasswordStorage.php)
+ */
+
+
+namespace Xibo\Helper;
+
+use Xibo\Support\Exception\InvalidArgumentException;
+
+/**
+ * Class Pbkdf2Hash
+ * @package Xibo\Helper
+ */
+class Pbkdf2Hash
+{
+    // These constants may be changed without breaking existing hashes.
+    const PBKDF2_HASH_ALGORITHM = 'sha256';
+    const PBKDF2_ITERATIONS = 1000;
+    const PBKDF2_SALT_BYTES = 24;
+    const PBKDF2_HASH_BYTES = 24;
+
+    // These constants define the encoding and may not be changed.
+    const HASH_SECTIONS = 4;
+    const HASH_ALGORITHM_INDEX = 0;
+    const HASH_ITERATION_INDEX = 1;
+    const HASH_SALT_INDEX = 2;
+    const HASH_PBKDF2_INDEX = 3;
+
+    /**
+     * @param string $password
+     * @param string $hash
+     * @return bool
+     * @throws InvalidArgumentException
+     */
+    public static function verifyPassword($password, $hash)
+    {
+        $params = explode(':', $hash);
+        if (count($params) < self::HASH_SECTIONS) {
+            throw new InvalidArgumentException(__('Invalid password hash - not enough hash sections'));
+        }
+
+        $pbkdf2 = base64_decode($params[self::HASH_PBKDF2_INDEX]);
+
+        // Check to see if the hash created from the provided password is the same as the hash we have stored already
+        return (self::slowEquals(
+            $pbkdf2,
+            self::pbkdf2(
+                $params[self::HASH_ALGORITHM_INDEX],
+                $password,
+                $params[self::HASH_SALT_INDEX],
+                (int)$params[self::HASH_ITERATION_INDEX],
+                strlen($pbkdf2),
+                true
+            )
+        ));
+    }
+
+    /**
+     * Compares two strings $a and $b in length-constant time.
+     * @param string $a
+     * @param string $b
+     * @return bool
+     */
+    private static function slowEquals($a, $b)
+    {
+        $diff = strlen($a) ^ strlen($b);
+        for($i = 0; $i < strlen($a) && $i < strlen($b); $i++)
+        {
+            $diff |= ord($a[$i]) ^ ord($b[$i]);
+        }
+        return $diff === 0;
+    }
+
+    /**
+     * PBKDF2 key derivation function as defined by RSA's PKCS #5: https://www.ietf.org/rfc/rfc2898.txt
+     *
+     * 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
+     *
+     * @param string $algorithm The hash algorithm to use. Recommended: SHA256
+     * @param string $password The password.
+     * @param string $salt A salt that is unique to the password.
+     * @param int $count Iteration count. Higher is better, but slower. Recommended: At least 1000.
+     * @param int $key_length The length of the derived key in bytes.
+     * @param bool $raw_output If true, the key is returned in raw binary format. Hex encoded otherwise.
+     * @return string A $key_length-byte key derived from the password and salt.
+     * @throws InvalidArgumentException
+     */
+    public static function pbkdf2($algorithm, $password, $salt, $count, $key_length, $raw_output = false)
+    {
+        $algorithm = strtolower($algorithm);
+        if (!in_array($algorithm, hash_algos(), true))
+            throw new InvalidArgumentException('PBKDF2 ERROR: Invalid hash algorithm.');
+        if ($count <= 0 || $key_length <= 0)
+            throw new InvalidArgumentException('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));
+    }
+}