6 * Contains functions used to do authentication.
10 * functions/strings.php.
12 * @copyright © 1999-2007 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 * @param string $authz Authorization ID (since 1.5.2)
126 * @return string The response to be sent to the IMAP server
129 function digest_md5_response ($username,$password,$challenge,$service,$host,$authz='') {
130 $result=digest_md5_parse_challenge($challenge);
132 // verify server supports qop=auth
133 // $qop = explode(",",$result['qop']);
134 //if (!in_array("auth",$qop)) {
135 // rfc2831: client MUST fail if no qop methods supported
138 $cnonce = base64_encode(bin2hex(hmac_md5(microtime())));
139 $ncount = "00000001";
141 /* This can be auth (authentication only), auth-int (integrity protection), or
142 auth-conf (confidentiality protection). Right now only auth is supported.
143 DO NOT CHANGE THIS VALUE */
146 $digest_uri_value = $service . '/' . $host;
148 // build the $response_value
149 //FIXME This will probably break badly if a server sends more than one realm
150 $string_a1 = utf8_encode($username).":";
151 $string_a1 .= utf8_encode($result['realm']).":";
152 $string_a1 .= utf8_encode($password);
153 $string_a1 = hmac_md5($string_a1);
154 $A1 = $string_a1 . ":" . $result['nonce'] . ":" . $cnonce;
156 $A1 .= ":" . utf8_encode($authz);
158 $A1 = bin2hex(hmac_md5($A1));
159 $A2 = "AUTHENTICATE:$digest_uri_value";
160 // If qop is auth-int or auth-conf, A2 gets a little extra
161 if ($qop_value != 'auth') {
162 $A2 .= ':00000000000000000000000000000000';
164 $A2 = bin2hex(hmac_md5($A2));
166 $string_response = $result['nonce'] . ':' . $ncount . ':' . $cnonce . ':' . $qop_value;
167 $response_value = bin2hex(hmac_md5($A1.":".$string_response.":".$A2));
169 $reply = 'charset=utf-8,username="' . $username . '",realm="' . $result["realm"] . '",';
170 $reply .= 'nonce="' . $result['nonce'] . '",nc=' . $ncount . ',cnonce="' . $cnonce . '",';
171 $reply .= "digest-uri=\"$digest_uri_value\",response=$response_value";
172 $reply .= ',qop=' . $qop_value;
174 $reply .= ',authzid=' . $authz;
176 $reply = base64_encode($reply);
177 return $reply . "\r\n";
182 * Parse Digest-MD5 challenge.
183 * This function parses the challenge sent during DIGEST-MD5 authentication and
184 * returns an array. See the RFC for details on what's in the challenge string.
186 * @param string $challenge Digest-MD5 Challenge
187 * @return array Digest-MD5 challenge decoded data
190 function digest_md5_parse_challenge($challenge) {
191 $challenge=base64_decode($challenge);
192 while (isset($challenge)) {
193 if ($challenge{0} == ',') { // First char is a comma, must not be 1st time through loop
194 $challenge=substr($challenge,1);
196 $key=explode('=',$challenge,2);
199 if ($challenge{0} == '"') {
200 // We're in a quoted value
201 // Drop the first quote, since we don't care about it
202 $challenge=substr($challenge,1);
203 // Now explode() to the next quote, which is the end of our value
204 $val=explode('"',$challenge,2);
205 $challenge=$val[1]; // The rest of the challenge, work on it in next iteration of loop
206 $value=explode(',',$val[0]);
207 // Now, for those quoted values that are only 1 piece..
208 if (sizeof($value) == 1) {
209 $value=$value[0]; // Convert to non-array
212 // We're in a "simple" value - explode to next comma
213 $val=explode(',',$challenge,2);
214 if (isset($val[1])) {
221 $parsed["$key"]=$value;
222 } // End of while loop
227 * Creates a HMAC digest that can be used for auth purposes
228 * See RFCs 2104, 2617, 2831
229 * Uses mhash() extension if available
231 * @param string $data Data to apply hash function to.
232 * @param string $key Optional key, which, if supplied, will be used to
233 * calculate data's HMAC.
234 * @return string HMAC Digest string
237 function hmac_md5($data, $key='') {
238 if (extension_loaded('mhash')) {
240 $mhash=mhash(MHASH_MD5
,$data);
242 $mhash=mhash(MHASH_MD5
,$data,$key);
247 return pack('H*',md5($data));
249 $key = str_pad($key,64,chr(0x00));
250 if (strlen($key) > 64) {
251 $key = pack("H*",md5($key));
253 $k_ipad = $key ^
str_repeat(chr(0x36), 64) ;
254 $k_opad = $key ^
str_repeat(chr(0x5c), 64) ;
255 /* Heh, let's get recursive. */
256 $hmac=hmac_md5($k_opad . pack("H*",md5($k_ipad . $data)) );
261 * Fillin user and password based on SMTP auth settings.
263 * @param string $user Reference to SMTP username
264 * @param string $pass Reference to SMTP password (unencrypted)
267 function get_smtp_user(&$user, &$pass) {
268 global $username, $smtp_auth_mech,
269 $smtp_sitewide_user, $smtp_sitewide_pass;
271 if ($smtp_auth_mech == 'none') {
274 } elseif ( isset($smtp_sitewide_user) && isset($smtp_sitewide_pass) &&
275 !empty($smtp_sitewide_user)) {
276 $user = $smtp_sitewide_user;
277 $pass = $smtp_sitewide_pass;
280 $pass = sqauth_read_password();