Implementation of P_SHA1 algorithm in PHP

Question

we are trying to implement a function P_SHA1 means PHP. The pattern of the function written in Python. But, unfortunately, something is not working properly. Here is the imp

Answer 1

This is based on the C# method included in a reply to "signing SOAP message request via ADFS". I have successfully used it to sign SOAP requests and get the response I want.

function psha1($clientSecret, $serverSecret, $sizeBits = 256)
{
    $sizeBytes = $sizeBits / 8;

    $hmacKey = $clientSecret;
    $hashSize = 160; // HMAC_SHA1 length is always 160
    $bufferSize = $hashSize / 8 + strlen($serverSecret);
    $i = 0;

    $b1 = $serverSecret;
    $b2 = "";
    $temp = null;
    $psha = array();

    while ($i < $sizeBytes) {
        $b1 = hash_hmac('SHA1', $b1, $hmacKey, true);
        $b2 = $b1 . $serverSecret;
        $temp = hash_hmac('SHA1', $b2, $hmacKey, true);

        for ($j = 0; $j < strlen($temp); $j++) {
            if ($i < $sizeBytes) {
                $psha[$i] = $temp[$j];
                $i++;
            } else {
                break;
            }
        }
    }

    return implode("", $psha);
}

One thing of importance to note is that the client secret and server secret should be base64 decoded before being passed to this function.