net.manuellemos.sasl @(#) $Id: sasl.php,v 1.11 2005/10/31 18:43:27 mlemos Exp $ Copyright © (C) Manuel Lemos 2004 Manuel Lemos mlemos-at-acm.org en Provide a common interface to plug-in driver classes that implement different mechanisms for authentication used by clients of standard protocols like SMTP, POP3, IMAP, HTTP, etc.. Currently the supported authentication mechanisms are: PLAIN, LOGIN, CRAM-MD5, Digest and NTML (Windows or Samba). . {/metadocument} */ class sasl_client_class { /* Public variables */ /* {metadocument} error STRING Store the message that is returned when an error occurs. Check this variable to understand what happened when a call to any of the class functions has failed. This class uses cumulative error handling. This means that if one class functions that may fail is called and this variable was already set to an error message due to a failure in a previous call to the same or other function, the function will also fail and does not do anything. This allows programs using this class to safely call several functions that may fail and only check the failure condition after the last function call. Just set this variable to an empty string to clear the error condition. {/metadocument} */ var $error=''; /* {metadocument} mechanism STRING Store the name of the mechanism that was selected during the call to the Start function. You can access this variable but do not change it. {/metadocument} */ var $mechanism=''; /* {metadocument} encode_response BOOLEAN 1 Let the drivers inform the applications whether responses need to be encoded. Applications should check this variable before sending authentication responses to the server to determine if the responses need to be encoded, eventually with base64 algorithm. {/metadocument} */ var $encode_response=1; /* Private variables */ var $driver; var $drivers=array( "Digest" => array("digest_sasl_client_class", "digest_sasl_client.inc" ), "CRAM-MD5" => array("cram_md5_sasl_client_class", "cram_md5_sasl_client.inc" ), "LOGIN" => array("login_sasl_client_class", "login_sasl_client.inc" ), "NTLM" => array("ntlm_sasl_client_class", "ntlm_sasl_client.inc" ), "PLAIN" => array("plain_sasl_client_class", "plain_sasl_client.inc" ), "Basic" => array("basic_sasl_client_class", "basic_sasl_client.inc" ) ); var $credentials=array(); /* Public functions */ /* {metadocument} SetCredential VOID Store the value of a credential that may be used by any of the supported mechanisms to process the authentication messages and responses. Call this function before starting the authentication dialog to pass all the credential values that be needed to use the type of authentication that the applications may need. . key STRING Specify the name of the credential key. value STRING Specify the value for the credential. {/metadocument} */ Function SetCredential($key,$value) { $this->credentials[$key]=$value; } /* {metadocument} {/metadocument} */ /* {metadocument} GetCredentials INTEGER Retrieve the values of one or more credentials to be used by the authentication mechanism classes. This is meant to be used by authentication mechanism driver classes to retrieve the credentials that may be neede. The function may return SASL_CONTINUE if it succeeded, or SASL_NOMECH if it was not possible to retrieve one of the requested credentials. credentials HASH Reference to an associative array variable with all the credentials that are being requested. The function initializes this associative array values. defaults HASH Associative arrays with default values for credentials that may have not been defined. interactions ARRAY Not yet in use. It is meant to provide context information to retrieve credentials that may be obtained interacting with the user. {/metadocument} */ Function GetCredentials(&$credentials,$defaults,&$interactions) { Reset($credentials); $end=(GetType($key=Key($credentials))!="string"); for(;!$end;) { if(!IsSet($this->credentials[$key])) { if(IsSet($defaults[$key])) $credentials[$key]=$defaults[$key]; else { $this->error="the requested credential ".$key." is not defined"; return(SASL_NOMECH); } } else $credentials[$key]=$this->credentials[$key]; Next($credentials); $end=(GetType($key=Key($credentials))!="string"); } return(SASL_CONTINUE); } /* {metadocument} {/metadocument} */ /* {metadocument} Start INTEGER Process the initial authentication step initializing the driver class that implements the first of the list of requested mechanisms that is supported by this SASL client library implementation. Call this function specifying a list of mechanisms that the server supports. If the message Start argument returns a string, it should be sent to the server as initial message. Check the encode_response variable to determine whether the initial message needs to be encoded, eventually with base64 algorithm, before it is sent to the server. The function may return SASL_CONTINUE if it could start one of the requested authentication mechanisms. It may return SASL_NOMECH if it was not possible to start any of the requested mechanisms. It returns SASL_FAIL or other value in case of error. mechanisms ARRAY Define the list of names of authentication mechanisms supported by the that should be tried. message STRING Return the initial message that should be sent to the server to start the authentication dialog. If this value is undefined, no message should be sent to the server. interactions ARRAY Not yet in use. It is meant to provide context information to interact with the end user. {/metadocument} */ Function Start($mechanisms, &$message, &$interactions) { if(strlen($this->error)) return(SASL_FAIL); if(IsSet($this->driver)) return($this->driver->Start($this,$message,$interactions)); $no_mechanism_error=""; for($m=0;$mdrivers[$mechanism])) { if(!class_exists($this->drivers[$mechanism][0])) require(dirname(__FILE__)."/".$this->drivers[$mechanism][1]); $this->driver=new $this->drivers[$mechanism][0]; if($this->driver->Initialize($this)) { $this->encode_response=1; $status=$this->driver->Start($this,$message,$interactions); switch($status) { case SASL_NOMECH: Unset($this->driver); if(strlen($no_mechanism_error)==0) $no_mechanism_error=$this->error; $this->error=""; break; case SASL_CONTINUE: $this->mechanism=$mechanism; return($status); default: Unset($this->driver); $this->error=""; return($status); } } else { Unset($this->driver); if(strlen($no_mechanism_error)==0) $no_mechanism_error=$this->error; $this->error=""; } } } $this->error=(strlen($no_mechanism_error) ? $no_mechanism_error : "it was not requested any of the authentication mechanisms that are supported"); return(SASL_NOMECH); } /* {metadocument} {/metadocument} */ /* {metadocument} Step INTEGER Process the authentication steps after the initial step, until the authetication iteration dialog is complete. Call this function iteratively after a successful initial step calling the Start function. The function returns SASL_CONTINUE if step was processed successfully, or returns SASL_FAIL in case of error. response STRING Pass the response returned by the server to the previous step. message STRING Return the message that should be sent to the server to continue the authentication dialog. If this value is undefined, no message should be sent to the server. interactions ARRAY Not yet in use. It is meant to provide context information to interact with the end user. {/metadocument} */ Function Step($response, &$message, &$interactions) { if(strlen($this->error)) return(SASL_FAIL); return($this->driver->Step($this,$response,$message,$interactions)); } /* {metadocument} {/metadocument} */ }; /* {metadocument} {/metadocument} */ ?>