added HMAC support to PassHash class FS#2794

2 files changed, 69 insertions, 0 deletions

diff --git a/_test/tests/inc/PassHash.test.php b/_test/tests/inc/PassHash.test.php
new file mode 100644
index 000000000..b6cb07090
--- /dev/null
+++ b/_test/tests/inc/PassHash.test.php
@@ -0,0 +1,22 @@
+<?php
+
+/**
+ * Class PassHash_test
+ *
+ * most tests are in auth_password.test.php
+ */
+class PassHash_test extends PHPUnit_Framework_TestCase {
+
+    function test_hmac(){
+        // known hashes taken from https://code.google.com/p/yii/issues/detail?id=1942
+        $this->assertEquals('df08aef118f36b32e29d2f47cda649b6', PassHash::hmac('md5','data','secret'));
+        $this->assertEquals('9818e3306ba5ac267b5f2679fe4abd37e6cd7b54', PassHash::hmac('sha1','data','secret'));
+
+        // known hashes from https://en.wikipedia.org/wiki/Hash-based_message_authentication_code
+        $this->assertEquals('74e6f7298a9c2d168935f58c001bad88', PassHash::hmac('md5','',''));
+        $this->assertEquals('fbdb1d1b18aa6c08324b7d64b71fb76370690e1d', PassHash::hmac('sha1','',''));
+        $this->assertEquals('80070713463e7749b90c2dc24911e275', PassHash::hmac('md5','The quick brown fox jumps over the lazy dog','key'));
+        $this->assertEquals('de7c9b85b8b78aa6bc8a7a36f70a90701c9db4d9', PassHash::hmac('sha1','The quick brown fox jumps over the lazy dog','key'));
+
+    }
+}
\ No newline at end of file
diff --git a/inc/PassHash.class.php b/inc/PassHash.class.php
index 080fb4778..61bd74939 100644
--- a/inc/PassHash.class.php
+++ b/inc/PassHash.class.php
@@ -494,4 +494,51 @@ class PassHash {
         $this->init_salt($salt, 8, false);
         return ':B:'.$salt.':'.md5($salt.'-'.md5($clear));
     }
+
+    /**
+     * Wraps around native hash_hmac() or reimplents it
+     *
+     * This is not directly used as password hashing method, and thus isn't callable via the
+     * verify_hash() method. It should be used to create signatures and might be used in other
+     * password hashing methods.
+     *
+     * @see hash_hmac()
+     * @author KC Cloyd
+     * @link http://www.php.net/manual/en/function.hash-hmac.php#93440
+     *
+     * @param string $algo Name of selected hashing algorithm (i.e. "md5", "sha256", "haval160,4",
+     *                     etc..) See hash_algos() for a list of supported algorithms.
+     * @param string $data Message to be hashed.
+     * @param string $key  Shared secret key used for generating the HMAC variant of the message digest.
+     * @param bool $raw_output When set to TRUE, outputs raw binary data. FALSE outputs lowercase hexits.
+     *
+     * @return string
+     */
+    public static function hmac($algo, $data, $key, $raw_output = false) {
+        // use native function if available and not in unit test
+        if(function_exists('hash_hmac') && !defined('SIMPLE_TEST')){
+            return hash_hmac($algo, $data, $key, $raw_output);
+        }
+
+        $algo = strtolower($algo);
+        $pack = 'H' . strlen($algo('test'));
+        $size = 64;
+        $opad = str_repeat(chr(0x5C), $size);
+        $ipad = str_repeat(chr(0x36), $size);
+
+        if(strlen($key) > $size) {
+            $key = str_pad(pack($pack, $algo($key)), $size, chr(0x00));
+        } else {
+            $key = str_pad($key, $size, chr(0x00));
+        }
+
+        for($i = 0; $i < strlen($key) - 1; $i++) {
+            $opad[$i] = $opad[$i] ^ $key[$i];
+            $ipad[$i] = $ipad[$i] ^ $key[$i];
+        }
+
+        $output = $algo($opad . pack($pack, $algo($ipad . $data)));
+
+        return ($raw_output) ? pack($pack, $output) : $output;
+    }
 }