6 * Contains functions used to do authentication.
10 * functions/strings.php.
12 * @copyright © 1999-2006 The SquirrelMail Project Team
13 * @license http://opensource.org/licenses/gpl-license.php GNU Public License
15 * @package squirrelmail
20 * Detect whether user is logged in
22 * Function is similar to is_logged_in() function. If user is logged in, function
23 * returns true. If user is not logged in or session is expired, function saves $_POST
24 * and $PHP_SELF in session and returns false. POST information is saved in
25 * 'session_expired_post' variable, PHP_SELF is saved in 'session_expired_location'.
27 * Script that uses this function instead of is_logged_in() function, must handle user
32 function sqauth_is_logged_in() {
33 if ( sqsession_is_registered('user_is_logged_in') ) {
37 // First we store some information in the new session to prevent
39 sqGetGlobalVar('PHP_SELF', $PHP_SELF, SQ_SERVER
);
41 $session_expired_post = $_POST;
42 $session_expired_location = $PHP_SELF;
43 if (!sqsession_is_registered('session_expired_post')) {
44 sqsession_register($session_expired_post,'session_expired_post');
46 if (!sqsession_is_registered('session_expired_location')) {
47 sqsession_register($session_expired_location,'session_expired_location');
49 session_write_close();
55 * Reads and decodes stored user password information
57 * Direct access to password information is deprecated.
58 * @return string password in plain text
61 function sqauth_read_password() {
62 sqgetGlobalVar('key', $key, SQ_COOKIE
);
63 sqgetGlobalVar('onetimepad', $onetimepad,SQ_SESSION
);
65 return OneTimePadDecrypt($key, $onetimepad);
69 * Saves or updates user password information
71 * This function is used to update password information that SquirrelMail
72 * stores during existing web session. It does not modify password stored
73 * in authentication system used by IMAP server.
75 * Function must be called before any html output started. Direct access
76 * to password information is deprecated. Saved password information is
77 * available only to next executed SquirrelMail script. If your script needs
78 * access to saved password after sqauth_save_password() call, use returned
80 * @param string $pass password
81 * @return string password encrypted with OTP. In case script wants to access
82 * password information before reloading page.
85 function sqauth_save_password($pass) {
86 sqgetGlobalVar('base_uri', $base_uri, SQ_SESSION
);
88 $onetimepad = OneTimePadCreate(strlen($pass));
89 sqsession_register($onetimepad,'onetimepad');
90 $key = OneTimePadEncrypt($pass, $onetimepad);
91 sqsetcookie('key', $key, false, $base_uri);
96 * Given the challenge from the server, supply the response using cram-md5 (See
97 * RFC 2195 for details)
99 * @param string $username User ID
100 * @param string $password User password supplied by User
101 * @param string $challenge The challenge supplied by the server
102 * @return string The response to be sent to the IMAP server
105 function cram_md5_response ($username,$password,$challenge) {
106 $challenge=base64_decode($challenge);
107 $hash=bin2hex(hmac_md5($challenge,$password));
108 $response=base64_encode($username . " " . $hash) . "\r\n";
113 * Return Digest-MD5 response.
114 * Given the challenge from the server, calculate and return the
115 * response-string for digest-md5 authentication. (See RFC 2831 for more
118 * @param string $username User ID
119 * @param string $password User password supplied by User
120 * @param string $challenge The challenge supplied by the server
121 * @param string $service The service name, usually 'imap'; it is used to
122 * define the digest-uri.
123 * @param string $host The host name, usually the server's FQDN; it is used to
124 * define the digest-uri.
125 * @return string The response to be sent to the IMAP server
128 function digest_md5_response ($username,$password,$challenge,$service,$host) {
129 $result=digest_md5_parse_challenge($challenge);
131 // verify server supports qop=auth
132 // $qop = explode(",",$result['qop']);
133 //if (!in_array("auth",$qop)) {
134 // rfc2831: client MUST fail if no qop methods supported
137 $cnonce = base64_encode(bin2hex(hmac_md5(microtime())));
138 $ncount = "00000001";
140 /* This can be auth (authentication only), auth-int (integrity protection), or
141 auth-conf (confidentiality protection). Right now only auth is supported.
142 DO NOT CHANGE THIS VALUE */
145 $digest_uri_value = $service . '/' . $host;
147 // build the $response_value
148 //FIXME This will probably break badly if a server sends more than one realm
149 $string_a1 = utf8_encode($username).":";
150 $string_a1 .= utf8_encode($result['realm']).":";
151 $string_a1 .= utf8_encode($password);
152 $string_a1 = hmac_md5($string_a1);
153 $A1 = $string_a1 . ":" . $result['nonce'] . ":" . $cnonce;
154 $A1 = bin2hex(hmac_md5($A1));
155 $A2 = "AUTHENTICATE:$digest_uri_value";
156 // If qop is auth-int or auth-conf, A2 gets a little extra
157 if ($qop_value != 'auth') {
158 $A2 .= ':00000000000000000000000000000000';
160 $A2 = bin2hex(hmac_md5($A2));
162 $string_response = $result['nonce'] . ':' . $ncount . ':' . $cnonce . ':' . $qop_value;
163 $response_value = bin2hex(hmac_md5($A1.":".$string_response.":".$A2));
165 $reply = 'charset=utf-8,username="' . $username . '",realm="' . $result["realm"] . '",';
166 $reply .= 'nonce="' . $result['nonce'] . '",nc=' . $ncount . ',cnonce="' . $cnonce . '",';
167 $reply .= "digest-uri=\"$digest_uri_value\",response=$response_value";
168 $reply .= ',qop=' . $qop_value;
169 $reply = base64_encode($reply);
170 return $reply . "\r\n";
175 * Parse Digest-MD5 challenge.
176 * This function parses the challenge sent during DIGEST-MD5 authentication and
177 * returns an array. See the RFC for details on what's in the challenge string.
179 * @param string $challenge Digest-MD5 Challenge
180 * @return array Digest-MD5 challenge decoded data
183 function digest_md5_parse_challenge($challenge) {
184 $challenge=base64_decode($challenge);
185 while (isset($challenge)) {
186 if ($challenge{0} == ',') { // First char is a comma, must not be 1st time through loop
187 $challenge=substr($challenge,1);
189 $key=explode('=',$challenge,2);
192 if ($challenge{0} == '"') {
193 // We're in a quoted value
194 // Drop the first quote, since we don't care about it
195 $challenge=substr($challenge,1);
196 // Now explode() to the next quote, which is the end of our value
197 $val=explode('"',$challenge,2);
198 $challenge=$val[1]; // The rest of the challenge, work on it in next iteration of loop
199 $value=explode(',',$val[0]);
200 // Now, for those quoted values that are only 1 piece..
201 if (sizeof($value) == 1) {
202 $value=$value[0]; // Convert to non-array
205 // We're in a "simple" value - explode to next comma
206 $val=explode(',',$challenge,2);
207 if (isset($val[1])) {
214 $parsed["$key"]=$value;
215 } // End of while loop
220 * Creates a HMAC digest that can be used for auth purposes
221 * See RFCs 2104, 2617, 2831
222 * Uses mhash() extension if available
224 * @param string $data Data to apply hash function to.
225 * @param string $key Optional key, which, if supplied, will be used to
226 * calculate data's HMAC.
227 * @return string HMAC Digest string
230 function hmac_md5($data, $key='') {
231 if (extension_loaded('mhash')) {
233 $mhash=mhash(MHASH_MD5
,$data);
235 $mhash=mhash(MHASH_MD5
,$data,$key);
240 return pack('H*',md5($data));
242 $key = str_pad($key,64,chr(0x00));
243 if (strlen($key) > 64) {
244 $key = pack("H*",md5($key));
246 $k_ipad = $key ^
str_repeat(chr(0x36), 64) ;
247 $k_opad = $key ^
str_repeat(chr(0x5c), 64) ;
248 /* Heh, let's get recursive. */
249 $hmac=hmac_md5($k_opad . pack("H*",md5($k_ipad . $data)) );
254 * Fillin user and password based on SMTP auth settings.
256 * @param string $user Reference to SMTP username
257 * @param string $pass Reference to SMTP password (unencrypted)
260 function get_smtp_user(&$user, &$pass) {
261 global $username, $smtp_auth_mech,
262 $smtp_sitewide_user, $smtp_sitewide_pass;
264 if ($smtp_auth_mech == 'none') {
267 } elseif ( isset($smtp_sitewide_user) && isset($smtp_sitewide_pass) &&
268 !empty($smtp_sitewide_user)) {
269 $user = $smtp_sitewide_user;
270 $pass = $smtp_sitewide_pass;
273 $pass = sqauth_read_password();