digest headers generator algorithm

digest_auth_client.php

<?php
 
$wwwauth = $argv[1] ;
 
class DigestHeadersGenerator {
 
    public function H($param)
    {
        return md5($param);
    }
 
    public function KD($a,$b)
    {
        return $this->H("$a:$b");
    }
 
    public function parseHttpDigest($digest)
    {
        $data = array();
        $parts = explode(", ", $digest);
 
        foreach ($parts as $element) {
            $bits = explode("=", $element);
            $data[$bits[0]] = str_replace('"','', $bits[1]);
        }
        return $data;
    }
 
    public function headers($wwwauth, $user, $pass, $httpmethod, $uri)
    {
        list($dummy_digest, $value) = split(' ', $wwwauth, 2);
 
        $x = $this->parseHttpDigest($value);
        $realm = $x['realm'];
        $A1 = $this->H("{$user}:{$realm}:{$pass}");
 
        //echo " A1 " . $A1 . "\n" ;
 
        $A2 = $this->H("{$httpmethod}:{$uri}");
 
        //echo " A2 " . $A2 . "\n" ;
 
        if ($x['qop'] == 'auth') {
            $cnonce = time();
            $ncvalue = 1;
 
            $ncbin = (string) decbin( $ncvalue );
            $ncbin = substr("00000000",0,8 - strlen($ncbin)) . $ncbin;
 
            $noncebit = "{$x['nonce']}:{$ncbin}:{$cnonce}:auth:{$A2}";
            $respdig = $this->KD($A1, $noncebit);
        } else {
            # FIX: handle error here
        }
 
        //echo " Response " . $respdig . "\n";
 
        $base  = 'Digest username="'.$user.'", realm="';
        $base .= $x['realm'].'", nonce="'.$x['nonce'].'", opaque="'.$x['opaque'].'",';
        $base .= ' uri="'.$uri.'", cnonce="'.$cnonce;
        $base .= '", nc="'.$ncbin.'", response="'.$respdig.'", qop="auth"';
        return $base;
    }
}
 
function httpDigestGet($wwwauth)
{
    $gen = new DigestHeadersGenerator();
    $username = 'facundo.siquot@gmail.com';
    $password = md5('El Gran Mongo');
    $method   = 'GET';
    $uri      = 'http://ccmebackend.development.com/user-rest';
 
    //echo " md5 passwd " . $password . "\n";
    $authorization = $gen->headers($wwwauth,$username,$password,$method,$uri);
 
    $headers   = array();
    $headers[] = "Authorization: {$authorization}";
    $headers[] = "Accept: application/json"; 
    $headers[] = "Content-Type: application/json" ;
 
    $ch = curl_init();
 
    curl_setopt($ch,CURLOPT_URL,$uri);
    curl_setopt($ch,CURLOPT_RETURNTRANSFER,true);
    curl_setopt($ch,CURLOPT_USERAGENT,'CCME Test Digest Client');
    curl_setopt($ch,CURLOPT_HTTPHEADER,$headers);
    curl_setopt($ch,CURLOPT_HEADER,true);
    curl_setopt($ch,CURLINFO_HEADER_OUT,true);
  
    $output=curl_exec($ch);
    $info = curl_getinfo($ch);
 
    print_r($info['request_header']);
  
    curl_close($ch);
    return $output;
}
 
$response = httpDigestGet($wwwauth);
print_r($response);