1<?php
2
3/**
4 * This is the HMACSHA1 implementation for the OpenID library.
5 *
6 * PHP versions 4 and 5
7 *
8 * LICENSE: See the COPYING file included in this distribution.
9 *
10 * @access private
11 * @package OpenID
12 * @author JanRain, Inc. <openid@janrain.com>
13 * @copyright 2005-2008 Janrain, Inc.
14 * @license http://www.apache.org/licenses/LICENSE-2.0 Apache
15 */
16
17require_once 'Auth/OpenID.php';
18
19/**
20 * SHA1_BLOCKSIZE is this module's SHA1 blocksize used by the fallback
21 * implementation.
22 */
23define('Auth_OpenID_SHA1_BLOCKSIZE', 64);
24
25function Auth_OpenID_SHA1($text)
26{
27    if (function_exists('hash') &&
28        function_exists('hash_algos') &&
29        (in_array('sha1', hash_algos()))) {
30        // PHP 5 case (sometimes): 'hash' available and 'sha1' algo
31        // supported.
32        return hash('sha1', $text, true);
33    } else if (function_exists('sha1')) {
34        // PHP 4 case: 'sha1' available.
35        $hex = sha1($text);
36        $raw = '';
37        for ($i = 0; $i < 40; $i += 2) {
38            $hexcode = substr($hex, $i, 2);
39            $charcode = (int)base_convert($hexcode, 16, 10);
40            $raw .= chr($charcode);
41        }
42        return $raw;
43    } else {
44        // Explode.
45        trigger_error('No SHA1 function found', E_USER_ERROR);
46        return false;
47    }
48}
49
50/**
51 * Compute an HMAC/SHA1 hash.
52 *
53 * @access private
54 * @param string $key The HMAC key
55 * @param string $text The message text to hash
56 * @return string $mac The MAC
57 */
58function Auth_OpenID_HMACSHA1($key, $text)
59{
60    if (Auth_OpenID::bytes($key) > Auth_OpenID_SHA1_BLOCKSIZE) {
61        $key = Auth_OpenID_SHA1($key);
62    }
63
64    if (function_exists('hash_hmac') &&
65        function_exists('hash_algos') &&
66        (in_array('sha1', hash_algos()))) {
67        return hash_hmac('sha1', $text, $key, true);
68    }
69    // Home-made solution
70
71    $key = str_pad($key, Auth_OpenID_SHA1_BLOCKSIZE, chr(0x00));
72    $ipad = str_repeat(chr(0x36), Auth_OpenID_SHA1_BLOCKSIZE);
73    $opad = str_repeat(chr(0x5c), Auth_OpenID_SHA1_BLOCKSIZE);
74    $hash1 = Auth_OpenID_SHA1(($key ^ $ipad) . $text);
75    $hmac = Auth_OpenID_SHA1(($key ^ $opad) . $hash1);
76    return $hmac;
77}
78
79if (function_exists('hash') &&
80    function_exists('hash_algos') &&
81    (in_array('sha256', hash_algos()))) {
82    function Auth_OpenID_SHA256($text)
83    {
84        // PHP 5 case: 'hash' available and 'sha256' algo supported.
85        return hash('sha256', $text, true);
86    }
87    define('Auth_OpenID_SHA256_SUPPORTED', true);
88} else {
89    define('Auth_OpenID_SHA256_SUPPORTED', false);
90}
91
92if (function_exists('hash_hmac') &&
93    function_exists('hash_algos') &&
94    (in_array('sha256', hash_algos()))) {
95
96    function Auth_OpenID_HMACSHA256($key, $text)
97    {
98        // Return raw MAC (not hex string).
99        return hash_hmac('sha256', $text, $key, true);
100    }
101
102    define('Auth_OpenID_HMACSHA256_SUPPORTED', true);
103} else {
104    define('Auth_OpenID_HMACSHA256_SUPPORTED', false);
105}
106
107