UnivNautes

<?php

/*

 * cram_md5_sasl_client.php

 *

 * @(#) $Id: cram_md5_sasl_client.php,v 1.3 2004/11/17 08:00:37 mlemos Exp $

 *

 */

define("SASL_CRAM_MD5_STATE_START",             0);

define("SASL_CRAM_MD5_STATE_RESPOND_CHALLENGE", 1);

define("SASL_CRAM_MD5_STATE_DONE",              2);

class cram_md5_sasl_client_class

{

	var $credentials=array();

	var $state=SASL_CRAM_MD5_STATE_START;

	Function Initialize(&$client)

	{

		return(1);

	}

	Function HMACMD5($key,$text)

	{

		$key=(strlen($key)<64 ? str_pad($key,64,"\0") : substr($key,0,64));

		return(md5((str_repeat("\x5c", 64)^$key).pack("H32", md5((str_repeat("\x36", 64)^$key).$text))));

	}

	Function Start(&$client, &$message, &$interactions)

	{

		if($this->state!=SASL_CRAM_MD5_STATE_START)

		{

			$client->error="CRAM-MD5 authentication state is not at the start";

			return(SASL_FAIL);

		}

		$this->credentials=array(

			"user"=>"",

			"password"=>""

		);

		$defaults=array();

		$status=$client->GetCredentials($this->credentials,$defaults,$interactions);

		if($status==SASL_CONTINUE)

			$this->state=SASL_CRAM_MD5_STATE_RESPOND_CHALLENGE;

		Unset($message);

		return($status);

	}

	Function Step(&$client, $response, &$message, &$interactions)

	{

		switch($this->state)

		{

			case SASL_CRAM_MD5_STATE_RESPOND_CHALLENGE:

				$message=$this->credentials["user"]." ".$this->HMACMD5($this->credentials["password"], $response);

				$this->state=SASL_CRAM_MD5_STATE_DONE;

				break;

			case SASL_CRAM_MD5_STATE_DONE:

				$client->error="CRAM-MD5 authentication was finished without success";

				return(SASL_FAIL);

			default:

				$client->error="invalid CRAM-MD5 authentication step state";

				return(SASL_FAIL);

		}

		return(SASL_CONTINUE);

	}

};

?>