Generating Signatures for the Authentication Header in PHP - Paypal - php

Question

Having recently finished the process of having created the script that retrieves permissions from a account holder I now find that I have to convert the retrieved access token and token secret (from the GetAccessToken response) to the API signature in order to create a X-PAYPAL-AUTHORIZATION header.
The X-PAYPAL-AUTHORIZATION header contains:
A timestamp
The access token from the GetAccessToken response
A signature generated from the following information:
Your API username
Your API password
The access token from the GetAccessToken response
The token secret from the GetAccessToken response
The endpoint for the PayPal API operation's request, such as https://api.paypal.com/nvp
HTTPS delivery method, such as POST
Request parameters associated with the request
The problem is I can't find how to generate the signature. There are no guides in PHP (JAVA and Ruby).
I did however note the line in the guide I followed (first link) to retrieve the permissions:
PayPal provides SDKs that you can use to generate authentication header signatures for Java, PHP, and .NET. When you use the SDK, you will get two values, such as the following:
But what followed was the JAVA guide and I could not find anything amongth Paypal's SDKs.
Any help would be greatly appreciated!

Answer 1

This documentation actually cuts out the function from their PHP SDK that should do it for you.
private function generateAuthString($apiCred, $accessToken, $tokenSecret, $endpoint)
{
$callerUid = $apiCred->getUserName();
$callerPswd = $apiCred->getPassword();
$auth = new AuthSignature();
$response = $auth->genSign($callerUid,$callerPswd,$accessToken,$tokenSecret,'POST',$endpoint);
$authString =
"token=".$accessToken.
",signature=".$response['oauth_signature'].
",timestamp=".$response['oauth_timestamp'];
return $authString;
}