X-Git-Url: https://vcs.fsf.org/?p=squirrelmail.git;a=blobdiff_plain;f=functions%2Fauth.php;h=d1d73ea07884ac08784c36b97e7008b0e24afb09;hp=f713746a8496259fd276baad0dbd44324e9e138c;hb=1710ad6563993035601d94fe96f68c9b964e866c;hpb=4b4abf93a9624311afef0c385023724ee46a2b60

diff --git a/functions/auth.php b/functions/auth.php
index f713746a..d1d73ea0 100644
--- a/functions/auth.php
+++ b/functions/auth.php
@@ -4,70 +4,136 @@
  * auth.php
  *
  * Contains functions used to do authentication.
+ * 
+ * Dependencies:
+ *  functions/global.php
+ *  functions/strings.php.
  *
- * @copyright © 1999-2005 The SquirrelMail Project Team
+ * @copyright 1999-2021 The SquirrelMail Project Team
  * @license http://opensource.org/licenses/gpl-license.php GNU Public License
  * @version $Id$
  * @package squirrelmail
  */
 
-/** Put in a safety net here, in case a naughty admin didn't run conf.pl when they upgraded */
 
-if (! isset($smtp_auth_mech)) {
-    $smtp_auth_mech = 'none';
-}
+/**
+ * Detect whether user is logged in
+ *
+ * Function is similar to is_logged_in() function. If user is logged in, function
+ * returns true. If user is not logged in or session is expired, function saves $_POST
+ * and PAGE_NAME in session and returns false. POST information is saved in
+ * 'session_expired_post' variable, PAGE_NAME is saved in 'session_expired_location'.
+ *
+ * This function optionally checks the referrer of this page request.  If the
+ * administrator wants to impose a check that the referrer of this page request
+ * is another page on the same domain (otherwise, the page request is likely
+ * the result of a XSS or phishing attack), then they need to specify the
+ * acceptable referrer domain in a variable named $check_referrer in
+ * config/config.php (or the configuration tool) for which the value is
+ * usually the same as the $domain setting (for example:
+ *    $check_referrer = 'example.com';
+ * However, in some cases (where proxy servers are in use, etc.), the
+ * acceptable referrer might be different.  If $check_referrer is set to
+ * "###DOMAIN###", then the current value of $domain is used (useful in
+ * situations where $domain might change at runtime (when using the Login
+ * Manager plugin to host multiple domains with one SquirrelMail installation,
+ * for example)):
+ *    $check_referrer = '###DOMAIN###';
+ * NOTE HOWEVER, that referrer checks are not foolproof - they can be spoofed
+ * by browsers, and some browsers intentionally don't send them, in which
+ * case SquirrelMail silently ignores referrer checks.  
+ *
+ * Script that uses this function instead of is_logged_in() function, must handle user
+ * level messages.
+ * @return boolean
+ * @since 1.5.1
+ */
+function sqauth_is_logged_in() {
 
-if (! isset($imap_auth_mech)) {
-    $imap_auth_mech = 'login';
-}
+    global $check_referrer, $domain;
+    if (!sqgetGlobalVar('HTTP_REFERER', $referrer, SQ_SERVER)) $referrer = '';
+    if ($check_referrer == '###DOMAIN###') $check_referrer = $domain;
+    if (!empty($check_referrer)) {
+        $ssl_check_referrer = 'https://' . $check_referrer;
+        $plain_check_referrer = 'http://' . $check_referrer;
+    }
+    if (sqsession_is_registered('user_is_logged_in')
+     && (!$check_referrer || empty($referrer)
+      || ($check_referrer && !empty($referrer)
+       && (strpos(strtolower($referrer), strtolower($plain_check_referrer)) === 0
+        || strpos(strtolower($referrer), strtolower($ssl_check_referrer)) === 0)))) {
+        return true;
+    }
 
-if (! isset($use_imap_tls)) {
-    $use_imap_tls = false;
-}
+    //  First we store some information in the new session to prevent
+    //  information-loss.
+    $session_expired_post = $_POST;
+    if (defined('PAGE_NAME'))
+        $session_expired_location = PAGE_NAME;
+    else
+        $session_expired_location = '';
+
+    if (!sqsession_is_registered('session_expired_post')) {
+        sqsession_register($session_expired_post,'session_expired_post');
+    }
+    if (!sqsession_is_registered('session_expired_location')) {
+        sqsession_register($session_expired_location,'session_expired_location');
+    }
 
-if (! isset($use_smtp_tls)) {
-    $use_smtp_tls = false;
+    session_write_close();
+
+    return false;
 }
 
 /**
- * Check if user has previously logged in to the SquirrelMail session.  If user
- * has not logged in, execution will stop inside this function.
+ * Reads and decodes stored user password information
  *
- * @return int A positive value is returned if user has previously logged in
- * successfully.
+ * Direct access to password information is deprecated.
+ * @return string password in plain text
+ * @since 1.5.1
  */
-function is_logged_in() {
+function sqauth_read_password() {
+    global $currentHookName;
+    if ($currentHookName == 'login_verified') global $key;
 
-    if ( sqsession_is_registered('user_is_logged_in') ) {
-        return;
-    } else {
-        global $PHP_SELF, $session_expired_post,
-               $session_expired_location, $squirrelmail_language;
-
-        //  First we store some information in the new session to prevent
-        //  information-loss.
-        //
-        $session_expired_post = $_POST;
-        $session_expired_location = $PHP_SELF;
-        if (!sqsession_is_registered('session_expired_post')) {
-            sqsession_register($session_expired_post,'session_expired_post');
-        }
-        if (!sqsession_is_registered('session_expired_location')) {
-            sqsession_register($session_expired_location,'session_expired_location');
-        }
+    sqgetGlobalVar('key',         $key,       SQ_COOKIE);
+    sqgetGlobalVar('onetimepad',  $onetimepad,SQ_SESSION);
 
-        // signout page will deal with users who aren't logged
-        // in on its own; don't show error here
-        //
-        if (strpos($PHP_SELF, 'signout.php') !== FALSE) {
-           return;
-        }
+    return OneTimePadDecrypt($key, $onetimepad);
+}
 
-        include_once( SM_PATH . 'functions/display_messages.php' );
-        set_up_language($squirrelmail_language, true);
-        logout_error( _("You must be logged in to access this page.") );
-        exit;
-    }
+/**
+ * Saves or updates user password information
+ *
+ * This function is used to update the password information that
+ * SquirrelMail stores in the existing PHP session. It does NOT 
+ * modify the password stored in the authentication system used
+ * by the IMAP server.
+ *
+ * This function must be called before any html output is started.
+ * Direct access to password information is deprecated. The saved
+ * password information is available only to the SquirrelMail script
+ * that is called/executed AFTER the current one. If your script
+ * needs access to the saved password after a sqauth_save_password()
+ * call, use the returned OTP encrypted key.
+ *
+ * @param string $pass password
+ *
+ * @return string Password encrypted with OTP. In case the script
+ *                wants to access the password information before
+ *                the end of its execution.
+ *
+ * @since 1.5.1
+ *
+ */
+function sqauth_save_password($pass) {
+    sqgetGlobalVar('base_uri',    $base_uri,   SQ_SESSION);
+
+    $onetimepad = OneTimePadCreate(strlen($pass));
+    sqsession_register($onetimepad,'onetimepad');
+    $key = OneTimePadEncrypt($pass, $onetimepad);
+    sqsetcookie('key', $key, false, $base_uri);
+    return $key;
 }
 
 /**
@@ -78,7 +144,7 @@ function is_logged_in() {
  * @param string $password User password supplied by User
  * @param string $challenge The challenge supplied by the server
  * @return string The response to be sent to the IMAP server
- *
+ * @since 1.4.0
  */
 function cram_md5_response ($username,$password,$challenge) {
     $challenge=base64_decode($challenge);
@@ -100,10 +166,13 @@ function cram_md5_response ($username,$password,$challenge) {
  *   define the digest-uri.
  * @param string $host The host name, usually the server's FQDN; it is used to
  *   define the digest-uri.
+ * @param string $authz Authorization ID (since 1.5.2)
  * @return string The response to be sent to the IMAP server
+ * @since 1.4.0
  */
-function digest_md5_response ($username,$password,$challenge,$service,$host) {
+function digest_md5_response ($username,$password,$challenge,$service,$host,$authz='') {
     $result=digest_md5_parse_challenge($challenge);
+    //FIXME we should check that $result contains the expected values that we use below
 
     // verify server supports qop=auth
     // $qop = explode(",",$result['qop']);
@@ -128,6 +197,9 @@ function digest_md5_response ($username,$password,$challenge,$service,$host) {
     $string_a1 .= utf8_encode($password);
     $string_a1 = hmac_md5($string_a1);
     $A1 = $string_a1 . ":" . $result['nonce'] . ":" . $cnonce;
+    if(!empty($authz)) {
+        $A1 .= ":" . utf8_encode($authz);
+    }
     $A1 = bin2hex(hmac_md5($A1));
     $A2 = "AUTHENTICATE:$digest_uri_value";
     // If qop is auth-int or auth-conf, A2 gets a little extra
@@ -143,6 +215,9 @@ function digest_md5_response ($username,$password,$challenge,$service,$host) {
     $reply .= 'nonce="' . $result['nonce'] . '",nc=' . $ncount . ',cnonce="' . $cnonce . '",';
     $reply .= "digest-uri=\"$digest_uri_value\",response=$response_value";
     $reply .= ',qop=' . $qop_value;
+    if(!empty($authz)) {
+        $reply .= ',authzid=' . $authz;
+    }
     $reply = base64_encode($reply);
     return $reply . "\r\n";
 
@@ -155,17 +230,19 @@ function digest_md5_response ($username,$password,$challenge,$service,$host) {
  *
  * @param string $challenge Digest-MD5 Challenge
  * @return array Digest-MD5 challenge decoded data
+ * @since 1.4.0
  */
 function digest_md5_parse_challenge($challenge) {
     $challenge=base64_decode($challenge);
-    while (isset($challenge)) {
-        if ($challenge{0} == ',') { // First char is a comma, must not be 1st time through loop
+    $parsed = array();
+    while (!empty($challenge)) {
+        if ($challenge[0] == ',') { // First char is a comma, must not be 1st time through loop
             $challenge=substr($challenge,1);
         }
         $key=explode('=',$challenge,2);
         $challenge=$key[1];
         $key=$key[0];
-        if ($challenge{0} == '"') {
+        if ($challenge[0] == '"') {
             // We're in a quoted value
             // Drop the first quote, since we don't care about it
             $challenge=substr($challenge,1);
@@ -193,36 +270,70 @@ function digest_md5_parse_challenge($challenge) {
 }
 
 /**
- * Creates a HMAC digest that can be used for auth purposes
- * See RFCs 2104, 2617, 2831
- * Uses mhash() extension if available
- *
- * @param string $data Data to apply hash function to.
- * @param string $key Optional key, which, if supplied, will be used to
- * calculate data's HMAC.
- * @return string HMAC Digest string
- */
+  * Creates a HMAC digest that can be used for authentication purposes
+  * See RFCs 2104, 2617, 2831
+  *
+  * Uses PHP's Hash extension if available (enabled by default in PHP
+  * 5.1.2+ - see http://www.php.net/manual/en/hash.requirements.php
+  * or, if installed on earlier PHP versions, the PECL hash module -
+  * see http://pecl.php.net/package/hash
+  *
+  * Otherwise, will attempt to use the Mhash extension - see
+  * http://www.php.net/manual/en/mhash.requirements.php
+  *
+  * Finally, a fall-back custom implementation is used if none of
+  * the above are available.
+  *
+  * @param string $data The data to be encoded/hashed
+  * @param string $key The (shared) secret key that will be used
+  *                    to build the keyed hash.  This argument is
+  *                    technically optional, but only for internal
+  *                    use (when the custom hash implementation is
+  *                    being used) - external callers should always
+  *                    specify a value for this argument.
+  *
+  * @return string The HMAC-MD5 digest string
+  * @since 1.4.0
+  *
+  */
 function hmac_md5($data, $key='') {
+
+    // use PHP's native Hash extension if possible
+    //
+    if (function_exists('hash_hmac'))
+        return pack('H*', hash_hmac('md5', $data, $key));
+
+
+    // otherwise, use (obsolete) mhash extension if available
+    //
     if (extension_loaded('mhash')) {
-        if ($key== '') {
-            $mhash=mhash(MHASH_MD5,$data);
-        } else {
-            $mhash=mhash(MHASH_MD5,$data,$key);
-        }
+
+        if ($key == '')
+            $mhash = mhash(MHASH_MD5, $data);
+        else
+            $mhash = mhash(MHASH_MD5, $data, $key);
+
         return $mhash;
     }
-    if (!$key) {
-        return pack('H*',md5($data));
-    }
-    $key = str_pad($key,64,chr(0x00));
-    if (strlen($key) > 64) {
-        $key = pack("H*",md5($key));
-    }
-    $k_ipad =  $key ^ str_repeat(chr(0x36), 64) ;
-    $k_opad =  $key ^ str_repeat(chr(0x5c), 64) ;
-    /* Heh, let's get recursive. */
-    $hmac=hmac_md5($k_opad . pack("H*",md5($k_ipad . $data)) );
+
+
+    // or, our own implementation...
+    //
+    if (!$key)
+        return pack('H*', md5($data));
+
+    $key = str_pad($key, 64, chr(0x00));
+
+    if (strlen($key) > 64)
+        $key = pack("H*", md5($key));
+
+    $k_ipad = $key ^ str_repeat(chr(0x36), 64);
+    $k_opad = $key ^ str_repeat(chr(0x5c), 64);
+
+    $hmac = hmac_md5($k_opad . pack('H*', md5($k_ipad . $data)));
+
     return $hmac;
+
 }
 
 /**
@@ -230,6 +341,7 @@ function hmac_md5($data, $key='') {
  *
  * @param string $user Reference to SMTP username
  * @param string $pass Reference to SMTP password (unencrypted)
+ * @since 1.4.11
  */
 function get_smtp_user(&$user, &$pass) {
     global $username, $smtp_auth_mech,
@@ -238,14 +350,25 @@ function get_smtp_user(&$user, &$pass) {
     if ($smtp_auth_mech == 'none') {
         $user = '';
         $pass = '';
-    } elseif ( isset($smtp_sitewide_user) && isset($smtp_sitewide_pass) ) {
+    } elseif ( isset($smtp_sitewide_user) && isset($smtp_sitewide_pass) &&
+               !empty($smtp_sitewide_user)) {
         $user = $smtp_sitewide_user;
         $pass = $smtp_sitewide_pass;
     } else {
-        global $key, $onetimepad;
         $user = $username;
-        $pass = OneTimePadDecrypt($key, $onetimepad);
+        $pass = sqauth_read_password();
     }
-}
 
-?>
\ No newline at end of file
+    // plugin authors note: override $user or $pass by
+    // directly changing the arguments array contents 
+    // in your plugin e.g., $args[0] = 'new_username';
+    //
+    // NOTE: there is another hook in class/deliver/Deliver_SMTP.class.php
+    // called "smtp_authenticate" that allows a plugin to run its own
+    // custom authentication routine - this hook here is thus slightly
+    // mis-named but is too old to change.  Be careful that you do not
+    // confuse your hook names.
+    //
+    $temp = array(&$user, &$pass);
+    do_hook('smtp_auth', $temp);
+}