6 * Contains functions used to do authentication. Library depends on
7 * functions from functions/global.php, functions/i18n.php and
8 * functions/strings.php.
10 * @copyright © 1999-2006 The SquirrelMail Project Team
11 * @license http://opensource.org/licenses/gpl-license.php GNU Public License
13 * @package squirrelmail
20 * Function is similar to is_logged_in() function. If user is logged in, function
21 * returns true. If user is not logged in or session is expired, function saves $_POST
22 * and $PHP_SELF in session and returns false. POST information is saved in
23 * 'session_expired_post' variable, PHP_SELF is saved in 'session_expired_location'.
25 * Script that uses this function instead of is_logged_in() function, must handle user
30 function sqauth_is_logged_in() {
31 if ( sqsession_is_registered('user_is_logged_in') ) {
34 global $PHP_SELF, $session_expired_post, $session_expired_location;
36 // First we store some information in the new session to prevent
39 $session_expired_post = $_POST;
40 $session_expired_location = $PHP_SELF;
41 if (!sqsession_is_registered('session_expired_post')) {
42 sqsession_register($session_expired_post,'session_expired_post');
44 if (!sqsession_is_registered('session_expired_location')) {
45 sqsession_register($session_expired_location,'session_expired_location');
53 * Reads and decodes stored user password information
55 * Direct access to password information is deprecated.
56 * @return string password in plain text
59 function sqauth_read_password() {
60 sqgetGlobalVar('key', $key, SQ_COOKIE
);
61 sqgetGlobalVar('onetimepad', $onetimepad,SQ_SESSION
);
63 return OneTimePadDecrypt($key, $onetimepad);
67 * Saves or updates user password information
69 * This function is used to update password information that SquirrelMail
70 * stores during existing web session. It does not modify password stored
71 * in authentication system used by IMAP server.
73 * Function must be called before any html output started. Direct access
74 * to password information is deprecated. Saved password information is
75 * available only to next executed SquirrelMail script. If your script needs
76 * access to saved password after sqauth_save_password() call, use returned
78 * @param string $pass password
79 * @return string password encrypted with OTP. In case script wants to access
80 * password information before reloading page.
83 function sqauth_save_password($pass) {
84 sqgetGlobalVar('base_uri', $base_uri, SQ_SESSION
);
86 $onetimepad = OneTimePadCreate(strlen($pass));
87 sqsession_register($onetimepad,'onetimepad');
88 $key = OneTimePadEncrypt($pass, $onetimepad);
89 sqsetcookie('key', $key, false, $base_uri);
94 * Given the challenge from the server, supply the response using cram-md5 (See
95 * RFC 2195 for details)
97 * @param string $username User ID
98 * @param string $password User password supplied by User
99 * @param string $challenge The challenge supplied by the server
100 * @return string The response to be sent to the IMAP server
103 function cram_md5_response ($username,$password,$challenge) {
104 $challenge=base64_decode($challenge);
105 $hash=bin2hex(hmac_md5($challenge,$password));
106 $response=base64_encode($username . " " . $hash) . "\r\n";
111 * Return Digest-MD5 response.
112 * Given the challenge from the server, calculate and return the
113 * response-string for digest-md5 authentication. (See RFC 2831 for more
116 * @param string $username User ID
117 * @param string $password User password supplied by User
118 * @param string $challenge The challenge supplied by the server
119 * @param string $service The service name, usually 'imap'; it is used to
120 * define the digest-uri.
121 * @param string $host The host name, usually the server's FQDN; it is used to
122 * define the digest-uri.
123 * @return string The response to be sent to the IMAP server
126 function digest_md5_response ($username,$password,$challenge,$service,$host) {
127 $result=digest_md5_parse_challenge($challenge);
129 // verify server supports qop=auth
130 // $qop = explode(",",$result['qop']);
131 //if (!in_array("auth",$qop)) {
132 // rfc2831: client MUST fail if no qop methods supported
135 $cnonce = base64_encode(bin2hex(hmac_md5(microtime())));
136 $ncount = "00000001";
138 /* This can be auth (authentication only), auth-int (integrity protection), or
139 auth-conf (confidentiality protection). Right now only auth is supported.
140 DO NOT CHANGE THIS VALUE */
143 $digest_uri_value = $service . '/' . $host;
145 // build the $response_value
146 //FIXME This will probably break badly if a server sends more than one realm
147 $string_a1 = utf8_encode($username).":";
148 $string_a1 .= utf8_encode($result['realm']).":";
149 $string_a1 .= utf8_encode($password);
150 $string_a1 = hmac_md5($string_a1);
151 $A1 = $string_a1 . ":" . $result['nonce'] . ":" . $cnonce;
152 $A1 = bin2hex(hmac_md5($A1));
153 $A2 = "AUTHENTICATE:$digest_uri_value";
154 // If qop is auth-int or auth-conf, A2 gets a little extra
155 if ($qop_value != 'auth') {
156 $A2 .= ':00000000000000000000000000000000';
158 $A2 = bin2hex(hmac_md5($A2));
160 $string_response = $result['nonce'] . ':' . $ncount . ':' . $cnonce . ':' . $qop_value;
161 $response_value = bin2hex(hmac_md5($A1.":".$string_response.":".$A2));
163 $reply = 'charset=utf-8,username="' . $username . '",realm="' . $result["realm"] . '",';
164 $reply .= 'nonce="' . $result['nonce'] . '",nc=' . $ncount . ',cnonce="' . $cnonce . '",';
165 $reply .= "digest-uri=\"$digest_uri_value\",response=$response_value";
166 $reply .= ',qop=' . $qop_value;
167 $reply = base64_encode($reply);
168 return $reply . "\r\n";
173 * Parse Digest-MD5 challenge.
174 * This function parses the challenge sent during DIGEST-MD5 authentication and
175 * returns an array. See the RFC for details on what's in the challenge string.
177 * @param string $challenge Digest-MD5 Challenge
178 * @return array Digest-MD5 challenge decoded data
181 function digest_md5_parse_challenge($challenge) {
182 $challenge=base64_decode($challenge);
183 while (isset($challenge)) {
184 if ($challenge{0} == ',') { // First char is a comma, must not be 1st time through loop
185 $challenge=substr($challenge,1);
187 $key=explode('=',$challenge,2);
190 if ($challenge{0} == '"') {
191 // We're in a quoted value
192 // Drop the first quote, since we don't care about it
193 $challenge=substr($challenge,1);
194 // Now explode() to the next quote, which is the end of our value
195 $val=explode('"',$challenge,2);
196 $challenge=$val[1]; // The rest of the challenge, work on it in next iteration of loop
197 $value=explode(',',$val[0]);
198 // Now, for those quoted values that are only 1 piece..
199 if (sizeof($value) == 1) {
200 $value=$value[0]; // Convert to non-array
203 // We're in a "simple" value - explode to next comma
204 $val=explode(',',$challenge,2);
205 if (isset($val[1])) {
212 $parsed["$key"]=$value;
213 } // End of while loop
218 * Creates a HMAC digest that can be used for auth purposes
219 * See RFCs 2104, 2617, 2831
220 * Uses mhash() extension if available
222 * @param string $data Data to apply hash function to.
223 * @param string $key Optional key, which, if supplied, will be used to
224 * calculate data's HMAC.
225 * @return string HMAC Digest string
228 function hmac_md5($data, $key='') {
229 if (extension_loaded('mhash')) {
231 $mhash=mhash(MHASH_MD5
,$data);
233 $mhash=mhash(MHASH_MD5
,$data,$key);
238 return pack('H*',md5($data));
240 $key = str_pad($key,64,chr(0x00));
241 if (strlen($key) > 64) {
242 $key = pack("H*",md5($key));
244 $k_ipad = $key ^
str_repeat(chr(0x36), 64) ;
245 $k_opad = $key ^
str_repeat(chr(0x5c), 64) ;
246 /* Heh, let's get recursive. */
247 $hmac=hmac_md5($k_opad . pack("H*",md5($k_ipad . $data)) );
252 * Fillin user and password based on SMTP auth settings.
254 * @param string $user Reference to SMTP username
255 * @param string $pass Reference to SMTP password (unencrypted)
258 function get_smtp_user(&$user, &$pass) {
259 global $username, $smtp_auth_mech,
260 $smtp_sitewide_user, $smtp_sitewide_pass;
262 if ($smtp_auth_mech == 'none') {
265 } elseif ( isset($smtp_sitewide_user) && isset($smtp_sitewide_pass) ) {
266 $user = $smtp_sitewide_user;
267 $pass = $smtp_sitewide_pass;
270 $pass = sqauth_read_password();