functions/auth.php

   1 <?php
   2
   3 /**
   4  * auth.php
   5  *
   6  * Copyright (c) 1999-2003 The SquirrelMail Project Team
   7  * Licensed under the GNU GPL. For full terms see the file COPYING.
   8  *
   9  * Contains functions used to do authentication.
  10  *
  11  * $Id$
  12  * @package squirrelmail
  13  */
  14
  15 /** Put in a safety net here, in case a naughty admin didn't run conf.pl when they upgraded */
  16
  17 if (! isset($smtp_auth_mech)) {
  18   $smtp_auth_mech = 'none';
  19 }
  20
  21 if (! isset($imap_auth_mech)) {
  22   $imap_auth_mech = 'login';
  23 }
  24
  25 if (! isset($use_imap_tls)) {
  26   $use_imap_tls = false;
  27 }
  28
  29 if (! isset($use_smtp_tls)) {
  30   $use_smtp_tls = false;
  31 }
  32
  33 function is_logged_in() {
  34
  35     if ( sqsession_is_registered('user_is_logged_in') ) {
  36         return;
  37     } else {
  38         global $PHP_SELF, $session_expired_post,
  39                $session_expired_location;
  40
  41         /*  First we store some information in the new session to prevent
  42          *  information-loss.
  43          */
  44
  45         $session_expired_post = $_POST;
  46         $session_expired_location = $PHP_SELF;
  47         if (!sqsession_is_registered('session_expired_post')) {
  48            sqsession_register($session_expired_post,'session_expired_post');
  49         }
  50         if (!sqsession_is_registered('session_expired_location')) {
  51            sqsession_register($session_expired_location,'session_expired_location');
  52         }
  53         include_once( SM_PATH . 'functions/display_messages.php' );
  54         logout_error( _("You must be logged in to access this page.") );
  55         exit;
  56     }
  57 }
  58
  59 function cram_md5_response ($username,$password,$challenge) {
  60
  61 /* Given the challenge from the server, supply the response using
  62    cram-md5 (See RFC 2195 for details)
  63 */
  64 $challenge=base64_decode($challenge);
  65 $hash=bin2hex(hmac_md5($challenge,$password));
  66 $response=base64_encode($username . " " . $hash) . "\r\n";
  67 return $response;
  68 }
  69
  70 function digest_md5_response ($username,$password,$challenge,$service,$host) {
  71 /* Given the challenge from the server, calculate and return the response-string
  72    for digest-md5 authentication.  (See RFC 2831 for more details) */
  73   $result=digest_md5_parse_challenge($challenge);
  74
  75 // verify server supports qop=auth
  76   // $qop = explode(",",$result['qop']);
  77   //if (!in_array("auth",$qop)) {
  78     // rfc2831: client MUST fail if no qop methods supported
  79    // return false;
  80   //}
  81   $cnonce = base64_encode(bin2hex(hmac_md5(microtime())));
  82   $ncount = "00000001";
  83
  84   /* This can be auth (authentication only), auth-int (integrity protection), or
  85      auth-conf (confidentiality protection).  Right now only auth is supported.
  86          DO NOT CHANGE THIS VALUE */
  87   $qop_value = "auth";
  88
  89   $digest_uri_value = $service . '/' . $host;
  90
  91   // build the $response_value
  92   //FIXME This will probably break badly if a server sends more than one realm
  93   $string_a1 = utf8_encode($username).":";
  94   $string_a1 .= utf8_encode($result['realm']).":";
  95   $string_a1 .= utf8_encode($password);
  96   $string_a1 = hmac_md5($string_a1);
  97   $A1 = $string_a1 . ":" . $result['nonce'] . ":" . $cnonce;
  98   $A1 = bin2hex(hmac_md5($A1));
  99   $A2 = "AUTHENTICATE:$digest_uri_value";
 100   // If qop is auth-int or auth-conf, A2 gets a little extra
 101   if ($qop_value != 'auth') {
 102     $A2 .= ':00000000000000000000000000000000';
 103   }
 104   $A2 = bin2hex(hmac_md5($A2));
 105
 106   $string_response = $result['nonce'] . ':' . $ncount . ':' . $cnonce . ':' . $qop_value;
 107   $response_value = bin2hex(hmac_md5($A1.":".$string_response.":".$A2));
 108
 109   $reply = 'charset=utf-8,username="' . $username . '",realm="' . $result["realm"] . '",';
 110   $reply .= 'nonce="' . $result['nonce'] . '",nc=' . $ncount . ',cnonce="' . $cnonce . '",';
 111   $reply .= "digest-uri=\"$digest_uri_value\",response=$response_value";
 112   $reply .= ',qop=' . $qop_value;
 113   $reply = base64_encode($reply);
 114   return $reply . "\r\n";
 115
 116 }
 117
 118 function digest_md5_parse_challenge($challenge) {
 119 /* This function parses the challenge sent during DIGEST-MD5 authentication and
 120    returns an array. See the RFC for details on what's in the challenge string.
 121 */
 122   $challenge=base64_decode($challenge);
 123   while (isset($challenge)) {
 124     if ($challenge{0} == ',') { // First char is a comma, must not be 1st time through loop
 125       $challenge=substr($challenge,1);
 126     }
 127     $key=explode('=',$challenge,2);
 128     $challenge=$key[1];
 129     $key=$key[0];
 130     if ($challenge{0} == '"') {
 131       // We're in a quoted value
 132       // Drop the first quote, since we don't care about it
 133       $challenge=substr($challenge,1);
 134       // Now explode() to the next quote, which is the end of our value
 135       $val=explode('"',$challenge,2);
 136       $challenge=$val[1]; // The rest of the challenge, work on it in next iteration of loop
 137       $value=explode(',',$val[0]);
 138       // Now, for those quoted values that are only 1 piece..
 139       if (sizeof($value) == 1) {
 140         $value=$value[0];  // Convert to non-array
 141       }
 142     } else {
 143       // We're in a "simple" value - explode to next comma
 144       $val=explode(',',$challenge,2);
 145       if (isset($val[1])) {
 146                 $challenge=$val[1];
 147           } else {
 148             unset($challenge);
 149           }
 150       $value=$val[0];
 151     }
 152     $parsed["$key"]=$value;
 153   } // End of while loop
 154   return $parsed;
 155 }
 156
 157 function hmac_md5($data, $key='') {
 158     // Creates a HMAC digest that can be used for auth purposes
 159     // See RFCs 2104, 2617, 2831
 160     // Uses mhash() extension if available
 161     if (extension_loaded('mhash')) {
 162       if ($key== '') {
 163         $mhash=mhash(MHASH_MD5,$data);
 164       } else {
 165         $mhash=mhash(MHASH_MD5,$data,$key);
 166       }
 167       return $mhash;
 168     }
 169     if (!$key) {
 170          return pack('H*',md5($data));
 171     }
 172     $key = str_pad($key,64,chr(0x00));
 173     if (strlen($key) > 64) {
 174         $key = pack("H*",md5($key));
 175     }
 176     $k_ipad =  $key ^ str_repeat(chr(0x36), 64) ;
 177     $k_opad =  $key ^ str_repeat(chr(0x5c), 64) ;
 178     /* Heh, let's get recursive. */
 179     $hmac=hmac_md5($k_opad . pack("H*",md5($k_ipad . $data)) );
 180     return $hmac;
 181 }
 182
 183 ?>