| 1 | <?php |
| 2 | |
| 3 | /** |
| 4 | * auth.php |
| 5 | * |
| 6 | * Copyright (c) 1999-2005 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 | * @version $Id$ |
| 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 | /** |
| 34 | * Check if user has previously logged in to the Squirrelmail session. If user |
| 35 | * has not logged in, execution will stop inside this function. |
| 36 | * |
| 37 | * @return int A positive value is returned if user has previously logged in |
| 38 | * successfully. |
| 39 | */ |
| 40 | function is_logged_in() { |
| 41 | |
| 42 | if ( sqsession_is_registered('user_is_logged_in') ) { |
| 43 | return; |
| 44 | } else { |
| 45 | global $PHP_SELF, $session_expired_post, |
| 46 | $session_expired_location, $squirrelmail_language; |
| 47 | |
| 48 | /* First we store some information in the new session to prevent |
| 49 | * information-loss. |
| 50 | */ |
| 51 | |
| 52 | $session_expired_post = $_POST; |
| 53 | $session_expired_location = $PHP_SELF; |
| 54 | if (!sqsession_is_registered('session_expired_post')) { |
| 55 | sqsession_register($session_expired_post,'session_expired_post'); |
| 56 | } |
| 57 | if (!sqsession_is_registered('session_expired_location')) { |
| 58 | sqsession_register($session_expired_location,'session_expired_location'); |
| 59 | } |
| 60 | include_once( SM_PATH . 'functions/display_messages.php' ); |
| 61 | set_up_language($squirrelmail_language, true); |
| 62 | logout_error( _("You must be logged in to access this page.") ); |
| 63 | exit; |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | /** |
| 68 | * Given the challenge from the server, supply the response using cram-md5 (See |
| 69 | * RFC 2195 for details) |
| 70 | * |
| 71 | * @param string $username User ID |
| 72 | * @param string $password User password supplied by User |
| 73 | * @param string $challenge The challenge supplied by the server |
| 74 | * @return string The response to be sent to the IMAP server |
| 75 | * |
| 76 | */ |
| 77 | function cram_md5_response ($username,$password,$challenge) { |
| 78 | $challenge=base64_decode($challenge); |
| 79 | $hash=bin2hex(hmac_md5($challenge,$password)); |
| 80 | $response=base64_encode($username . " " . $hash) . "\r\n"; |
| 81 | return $response; |
| 82 | } |
| 83 | |
| 84 | /** |
| 85 | * Return Digest-MD5 response. |
| 86 | * Given the challenge from the server, calculate and return the |
| 87 | * response-string for digest-md5 authentication. (See RFC 2831 for more |
| 88 | * details) |
| 89 | * |
| 90 | * @param string $username User ID |
| 91 | * @param string $password User password supplied by User |
| 92 | * @param string $challenge The challenge supplied by the server |
| 93 | * @param string $service The service name, usually 'imap'; it is used to |
| 94 | * define the digest-uri. |
| 95 | * @param string $host The host name, usually the server's FQDN; it is used to |
| 96 | * define the digest-uri. |
| 97 | * @return string The response to be sent to the IMAP server |
| 98 | */ |
| 99 | function digest_md5_response ($username,$password,$challenge,$service,$host) { |
| 100 | $result=digest_md5_parse_challenge($challenge); |
| 101 | |
| 102 | // verify server supports qop=auth |
| 103 | // $qop = explode(",",$result['qop']); |
| 104 | //if (!in_array("auth",$qop)) { |
| 105 | // rfc2831: client MUST fail if no qop methods supported |
| 106 | // return false; |
| 107 | //} |
| 108 | $cnonce = base64_encode(bin2hex(hmac_md5(microtime()))); |
| 109 | $ncount = "00000001"; |
| 110 | |
| 111 | /* This can be auth (authentication only), auth-int (integrity protection), or |
| 112 | auth-conf (confidentiality protection). Right now only auth is supported. |
| 113 | DO NOT CHANGE THIS VALUE */ |
| 114 | $qop_value = "auth"; |
| 115 | |
| 116 | $digest_uri_value = $service . '/' . $host; |
| 117 | |
| 118 | // build the $response_value |
| 119 | //FIXME This will probably break badly if a server sends more than one realm |
| 120 | $string_a1 = utf8_encode($username).":"; |
| 121 | $string_a1 .= utf8_encode($result['realm']).":"; |
| 122 | $string_a1 .= utf8_encode($password); |
| 123 | $string_a1 = hmac_md5($string_a1); |
| 124 | $A1 = $string_a1 . ":" . $result['nonce'] . ":" . $cnonce; |
| 125 | $A1 = bin2hex(hmac_md5($A1)); |
| 126 | $A2 = "AUTHENTICATE:$digest_uri_value"; |
| 127 | // If qop is auth-int or auth-conf, A2 gets a little extra |
| 128 | if ($qop_value != 'auth') { |
| 129 | $A2 .= ':00000000000000000000000000000000'; |
| 130 | } |
| 131 | $A2 = bin2hex(hmac_md5($A2)); |
| 132 | |
| 133 | $string_response = $result['nonce'] . ':' . $ncount . ':' . $cnonce . ':' . $qop_value; |
| 134 | $response_value = bin2hex(hmac_md5($A1.":".$string_response.":".$A2)); |
| 135 | |
| 136 | $reply = 'charset=utf-8,username="' . $username . '",realm="' . $result["realm"] . '",'; |
| 137 | $reply .= 'nonce="' . $result['nonce'] . '",nc=' . $ncount . ',cnonce="' . $cnonce . '",'; |
| 138 | $reply .= "digest-uri=\"$digest_uri_value\",response=$response_value"; |
| 139 | $reply .= ',qop=' . $qop_value; |
| 140 | $reply = base64_encode($reply); |
| 141 | return $reply . "\r\n"; |
| 142 | |
| 143 | } |
| 144 | |
| 145 | /** |
| 146 | * Parse Digest-MD5 challenge. |
| 147 | * This function parses the challenge sent during DIGEST-MD5 authentication and |
| 148 | * returns an array. See the RFC for details on what's in the challenge string. |
| 149 | * |
| 150 | * @param string $challenge Digest-MD5 Challenge |
| 151 | * @return array Digest-MD5 challenge decoded data |
| 152 | */ |
| 153 | function digest_md5_parse_challenge($challenge) { |
| 154 | $challenge=base64_decode($challenge); |
| 155 | while (isset($challenge)) { |
| 156 | if ($challenge{0} == ',') { // First char is a comma, must not be 1st time through loop |
| 157 | $challenge=substr($challenge,1); |
| 158 | } |
| 159 | $key=explode('=',$challenge,2); |
| 160 | $challenge=$key[1]; |
| 161 | $key=$key[0]; |
| 162 | if ($challenge{0} == '"') { |
| 163 | // We're in a quoted value |
| 164 | // Drop the first quote, since we don't care about it |
| 165 | $challenge=substr($challenge,1); |
| 166 | // Now explode() to the next quote, which is the end of our value |
| 167 | $val=explode('"',$challenge,2); |
| 168 | $challenge=$val[1]; // The rest of the challenge, work on it in next iteration of loop |
| 169 | $value=explode(',',$val[0]); |
| 170 | // Now, for those quoted values that are only 1 piece.. |
| 171 | if (sizeof($value) == 1) { |
| 172 | $value=$value[0]; // Convert to non-array |
| 173 | } |
| 174 | } else { |
| 175 | // We're in a "simple" value - explode to next comma |
| 176 | $val=explode(',',$challenge,2); |
| 177 | if (isset($val[1])) { |
| 178 | $challenge=$val[1]; |
| 179 | } else { |
| 180 | unset($challenge); |
| 181 | } |
| 182 | $value=$val[0]; |
| 183 | } |
| 184 | $parsed["$key"]=$value; |
| 185 | } // End of while loop |
| 186 | return $parsed; |
| 187 | } |
| 188 | |
| 189 | /** |
| 190 | * Creates a HMAC digest that can be used for auth purposes |
| 191 | * See RFCs 2104, 2617, 2831 |
| 192 | * Uses mhash() extension if available |
| 193 | * |
| 194 | * @param string $data Data to apply hash function to. |
| 195 | * @param string $key Optional key, which, if supplied, will be used to |
| 196 | * calculate data's HMAC. |
| 197 | * @return string HMAC Digest string |
| 198 | */ |
| 199 | function hmac_md5($data, $key='') { |
| 200 | if (extension_loaded('mhash')) { |
| 201 | if ($key== '') { |
| 202 | $mhash=mhash(MHASH_MD5,$data); |
| 203 | } else { |
| 204 | $mhash=mhash(MHASH_MD5,$data,$key); |
| 205 | } |
| 206 | return $mhash; |
| 207 | } |
| 208 | if (!$key) { |
| 209 | return pack('H*',md5($data)); |
| 210 | } |
| 211 | $key = str_pad($key,64,chr(0x00)); |
| 212 | if (strlen($key) > 64) { |
| 213 | $key = pack("H*",md5($key)); |
| 214 | } |
| 215 | $k_ipad = $key ^ str_repeat(chr(0x36), 64) ; |
| 216 | $k_opad = $key ^ str_repeat(chr(0x5c), 64) ; |
| 217 | /* Heh, let's get recursive. */ |
| 218 | $hmac=hmac_md5($k_opad . pack("H*",md5($k_ipad . $data)) ); |
| 219 | return $hmac; |
| 220 | } |
| 221 | |
| 222 | /** |
| 223 | * Fillin user and password based on SMTP auth settings. |
| 224 | * |
| 225 | * @param string $user Reference to SMTP username |
| 226 | * @param string $pass Reference to SMTP password (unencrypted) |
| 227 | */ |
| 228 | function get_smtp_user(&$user, &$pass) { |
| 229 | global $username, $smtp_auth_mech, |
| 230 | $smtp_sitewide_user, $smtp_sitewide_pass; |
| 231 | |
| 232 | if ($smtp_auth_mech == 'none') { |
| 233 | $user = ''; |
| 234 | $pass = ''; |
| 235 | } elseif ( isset($smtp_sitewide_user) && isset($smtp_sitewide_pass) ) { |
| 236 | $user = $smtp_sitewide_user; |
| 237 | $pass = $smtp_sitewide_pass; |
| 238 | } else { |
| 239 | global $key, $onetimepad; |
| 240 | $user = $username; |
| 241 | $pass = OneTimePadDecrypt($key, $onetimepad); |
| 242 | } |
| 243 | } |
| 244 | |
| 245 | ?> |