/**
* {@inheritDoc}
*/
public function buildSignature(Request $request, Consumer $consumer, Token $token = null)
{
$signatureBase = $request->getSignatureBaseString();
$parts = array($consumer->secret, null !== $token ? $token->secret : "");
$parts = Util::urlencodeRfc3986($parts);
$key = implode('&', $parts);
return base64_encode(hash_hmac('sha1', $signatureBase, $key, true));
}
