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