H4CK3R 4/hacker04/04_HACK04.ISO/src/PHP/validateemail.php3.txt

Text File | 2002-05-06 | 8.5 KB | 288 lines

<?php

/*


validateEmail() by Shane Y. Gibson

This is version validateEmail() augments the work that Jon Stevens originally wrote by (almost) fully documenting the code, and expands the $return array to include more (useful) information. An example chunk of code is also provided


 Originally
 By: Jon S. Stevens [e-mail]
 Copyright 1998 Jon S. Stevens, Clear Ink
 This code has all the normal disclaimers.
 It is free for any use, just keep the credits intact.

 Enacements and modifications:

           By:  Shane Y. Gibson  [e-mail]
 Organization:  The Unix Network Archives (http://www.tuna.org./)
         Date:  November 16th, 1998
      Changes:  Added **all** comments, as original code lacked them.
                Added some return codes to include a bit more description
                for useability.

 I disclaim nothing...nor do I claim anything...but
 it would be nice if you included this disclaimer...

*/

/*  This function takes in an email address (say '[e-mail]')
 *  and tests to see if it's a valid email address.
 *
 *  An array with the results is passed back to the caller.
 *
 *  Possible result codes for the array items are:
 *
 *  Item 0:  [true|false]        true for valid email address
 *                    false for NON-valid email address
 *
 *  Item 1:  [SMTP Code]        if a valid MX mail server found, then
 *                    fill this array in with failed SMTP
 *                    reply codes
 *
 *  Item 2:  [true|false]        true for valid mail server found for
 *                    host/domain
 *                    false if no valid mail server found
 *
 *  Item 3:  [MX server]        if a valid MX host was found and
 *                    connected to then fill in this item
 *                    with the MX server hostname
 *
 *  EXAMPLE code for use is at the very end of this function.
 */

function validateEmail ( $email )
{
    // used for SMTP HELO argument
    global $SERVER_NAME;

    // initialize our return array, populating with default values
    $return = array ( false, "", "", "" );

    // assign our user part and domain parts respectively to seperate             // variables
    list ( $user, $domain )  = split ( "@", $email, 2 );

    // split up the domain name into sub-parts
    $arr = explode ( ".", $domain );

    // figure out how many parts to the host/domain name portion there are
    $count = count ( $arr );

    // get our Top-Level Domain portion (i.e. foobar.org)
    $tld = $arr[$count - 2] . "." . $arr[$count - 1];

    // check that an MX record exists for Top-Level Domain, and if so
    // start our email address checking
    if ( checkdnsrr ( $tld, "MX" ) )
    {
        // Okay...valid dns reverse record; test that MX record for
        // host exists, and then fill the 'mxhosts' and 'weight'
        // arrays with the correct information
        //
        if ( getmxrr ( $tld, $mxhosts, $weight ) )
        {
            // sift through the 'mxhosts' connecting to each host
            for ( $i = 0; $i < count ( $mxhosts ); $i++ )
            {
                // open socket on port 25 to mxhosts, setting                         // returned file pointer to the variable 'fp'
                $fp = fsockopen ( $mxhosts[$i], 25 );

                // if the 'fp' was set, then goto work
                if ( $fp )
                {
                    // work variables
                    $s = 0;
                    $c = 0;
                    $out = "";

                    // set our created socket for 'fp' to
                    // non-blocking mode
                    // so our fgets() calls will return
                    // right away
                    set_socket_blocking ( $fp, false );

                    // as long as our 'out' variable has a
                    // null value ("")
                    // keep looping (do) until we get
                    // something
                    //
                    do
                    {
                        // output of the stream assigned
                        // to 'out' variable
                        $out = fgets ( $fp, 2500 );

                        // if we get an "220" code (service ready code (i.e greeting))
                        // increment our work (code (c)) variable, and null
                        // out our output variable for a later loop test
                        //
                        if ( ereg ( "^220", $out ) )
                        {
                            $s = 0;
                            $out = "";
                            $c++;
                            $return[2] = true;
                            $return[3] = $mxhosts[$i];
                        }
                        // elseif c is greater than 0
                        // and 'out' is null (""),
                        // we got a code back from some
                        // server, and we've passed
                        // through this loop at least
                        // once
                        //
                        else if ( ( $c > 0 ) && ( $out == "" ) )
                        {
                            $return[2] = true;
                            break;
                        }

                        // else increment our 's'
                        // counter
                        else
                        { $s++;    }

                        // and if 's' is 9999, break, to
                        // keep from looping
                        // infinetly
                        if ( $s == 9999 ) { break; }

                    } while ( $out == "" );

                    // reset our file pointer to blocking
                    // mode, so we wait
                    // for communication to finish before
                    // moving on...
                    set_socket_blocking ( $fp, true );

                    // talk to the MX mail server,
                    // validating ourself (HELO)
                    fputs ( $fp, "HELO $SERVER_NAME\n" );

                    // get the mail servers reply, assign to
                    // 'output' (ignored)
                    $output = fgets ( $fp, 2000 );

                    // give a bogus "MAIL FROM:" header to
                    // the server
                    fputs ( $fp, "MAIL FROM: <info@" . $tld . ">\n" );

                    // get output again (ignored)
                    $output = fgets ( $fp, 2000 );

                    // give RCPT TO: header for the email
                    // address we are testing
                    fputs ( $fp, "RCPT TO: <$email>\n" );

                    // get final output for validity testing
                    // (used)
                    $output = fgets ( $fp, 2000 );

                    // test the reply code from the mail
                    // server for the 250 (okay) code
                    if ( ereg ( "^250", $output ) )
                    {
                        // set our true/false(ness)
                        // array item for testing
                        $return[0] = true;
                    }
                    else
                    {
                        // otherwise, bogus address,
                        // fillin the 2nd array item
                        // with the mail servers reply
                        // code for user to test if they
                        // want
                        $return[0] = false;
                        $return[1] = $output;
                    }

                    // tell the mail server we are done
                    // talking to it
                    fputs ( $fp, "QUIT\n" );

                    // close the file pointer
                    fclose( $fp );

                    // if we got a good value break,
                    // otherwise, we'll keep
                    // trying MX records until we get a good
                    // value, or we
                    // exhaust our possible MX servers
                    if ( $return[0] == true )
                    { break; }
                }
            }
        }
    } else {
    // No MX record appears for the specified Top-Level Domain; possibly
    // an invalid host/domain name was specified.
        $return[0] = false;
        $return[1] = "Invalid email address (bad domain name)";
        $return[2] = false;
    } // end if checkdnsrr()

    // return the array for the user to test against
    return $return;
}
?>

<?php
    // Here is an example chunk of code...  Normally, you'd call the
    // validate email with a form or some other method to provide
    // the input email address
    //
    //  NOTE:  You need to delete the /* and */ comment entries

/*
// Minimal HTML code to test validateEmail() function.  Save this
// to a file to test...try different email addresses in the
// 'email_address' variable field to see how it behaves.
//
<html>
<head>
<tilte> Validate an email address. </title>
</head>

<body bgcolor="#000000" TEXT="#FFFFCC" LINK="#33CCFF" VLINK="#9999CC" ALINK="#FFFF00">

// Assumes that you put the validateEmail() function in a file
// named "validateEmail.php3", which is in the current directory
<?php  include( "validateEmail.php3" );

    $email_address = "[e-mail]";
    $val_results = array( "", "" );

    $val_results = validateEmail( $email_address );

    if ( $val_results[0] == true )
        {
            $value = "<font color=\"green\">a valid</font>";
        } else {
            $value = "<font color=\"red\">not a valid</font>";
        }

   // print debugging info
    print( "<br>Debugging Info:<br><br>" );
    print( "<pre>" );
    print( "(valid/not valid)                   <font color=\"white\">value</font> is: " . $value. "<br>");
    print( "(true/false valid email)   <font color=\"white\">val_results[0]</font> is: " . $val_results[0] . "<br>");
    print( "(SMTP code if false)       <font color=\"white\">val_results[1]</font> is: " . $val_results[1] . "<br>");
    print( "(true/false valid MX host) <font color=\"white\">val_results[2]</font> is: " . $val_results[2] . "<br>");
    print( "(MX host that answered)    <font color=\"white\">val_results[3]</font> is: " . $val_results[3] . "<br>");
    print( "</pre>" );
    print( "<pre>true is represented by a 1 (one)<br>false is represented by null output</pre><br>");
    // end debugging info

    print( "The address <font color=\"white\"><tt>" . $email_address . "</tt></font> is " . $value . " email address.");
*/

?>

</body>
</html>