title: the best implementation of RFC 2104 HMAC-SHA1
body: <p>What is the best implementation of RFC 2104 HMAC-SHA1 alg. in php?
  I have read <a href="http://us2.php.net/manual/en/function.hash-hmac.php" rel="nofollow">http://us2.php.net/manual/en/function.hash-hmac.php</a> but when I try them I get<br>
  different results.<br>
  Thank's</p>