function oauth_hmacsha1($key, $data) {
      return base64_encode(hmacsha1($key, $data));
  }
  function hmacsha1($key,$data) {
      $blocksize=64;
      $hashfunc='sha1';
      if (strlen($key)>$blocksize)
          $key=pack('H*', $hashfunc($key));
      $key=str_pad($key,$blocksize,chr(0x00));
      $ipad=str_repeat(chr(0x36),$blocksize);
      $opad=str_repeat(chr(0x5c),$blocksize);
      $hmac = pack(
                  'H*',$hashfunc(
                      ($key^$opad).pack(
                          'H*',$hashfunc(
                              ($key^$ipad).$data
                          )
                      )
                  )
              );
      return $hmac;
  }