Oauth signature generator failure - php

Question

I am using php cURL to PUT some informations (Authorization type: Oauth 1.0),
my problem is about generate the unique signature using the consumer_secret and access_token and encoded URL and the '&' also,
I tried to use two methods to generate it but the cURL response is: The signature is invalid. Verify and try again.
this is my last method to generate the signature:
// ------------- START GENERATE SIGNATURE -------------
$oauth = array(
"OAuth oauth_consumer_key=".$this->consumer_key.",
oauth_token=".$this->access_token.",
oauth_signature_method=".$this->signature_method.",
oauth_timestamp=".$timestimp.",
oauth_nonce=".$nonce.",
oauth_version=".$this->version.""
);
$base_info = $this->buildBaseString($this->url, 'PUT', $oauth) .'&';
$composite_key = rawurlencode($this->consumer_secret) . '&' . rawurlencode($this->access_token);
$oauth_signature = base64_encode(hash_hmac('sha1', $base_info, $composite_key, true));
// ------------- END GENERATE SIGNATURE -------------
and this is the buildBaseString function
function buildBaseString($baseURI, $method, $params)
{
$r = array();
ksort($params);
foreach($params as $key=>$value){
$r[] = "$key=" . rawurlencode($value);
}
return $method."&" . rawurlencode($baseURI) . '&' . rawurlencode(implode('&', $r));
}
I need help please.
thanks.