+/**
+ * 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;
+}
+
+/**
+ * Given the challenge from the server, supply the response using cram-md5 (See
+ * RFC 2195 for details)
+ *
+ * @param string $username User ID
+ * @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);
+ $hash=bin2hex(hmac_md5($challenge,$password));
+ $response=base64_encode($username . " " . $hash) . "\r\n";
+ return $response;
+}
+
+/**
+ * Return Digest-MD5 response.
+ * Given the challenge from the server, calculate and return the
+ * response-string for digest-md5 authentication. (See RFC 2831 for more
+ * details)
+ *
+ * @param string $username User ID
+ * @param string $password User password supplied by User
+ * @param string $challenge The challenge supplied by the server
+ * @param string $service The service name, usually 'imap'; it is used to
+ * 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,$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']);
+ //if (!in_array("auth",$qop)) {
+ // rfc2831: client MUST fail if no qop methods supported
+ // return false;
+ //}
+ $cnonce = base64_encode(bin2hex(hmac_md5(microtime())));
+ $ncount = "00000001";
+
+ /* This can be auth (authentication only), auth-int (integrity protection), or
+ auth-conf (confidentiality protection). Right now only auth is supported.
+ DO NOT CHANGE THIS VALUE */
+ $qop_value = "auth";
+
+ $digest_uri_value = $service . '/' . $host;
+
+ // build the $response_value
+ //FIXME This will probably break badly if a server sends more than one realm
+ $string_a1 = utf8_encode($username).":";
+ $string_a1 .= utf8_encode($result['realm']).":";
+ $string_a1 .= utf8_encode($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
+ if ($qop_value != 'auth') {
+ $A2 .= ':00000000000000000000000000000000';
+ }
+ $A2 = bin2hex(hmac_md5($A2));
+
+ $string_response = $result['nonce'] . ':' . $ncount . ':' . $cnonce . ':' . $qop_value;
+ $response_value = bin2hex(hmac_md5($A1.":".$string_response.":".$A2));
+
+ $reply = 'charset=utf-8,username="' . $username . '",realm="' . $result["realm"] . '",';
+ $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";
+
+}
+
+/**
+ * Parse Digest-MD5 challenge.
+ * This function parses the challenge sent during DIGEST-MD5 authentication and
+ * returns an array. See the RFC for details on what's in the challenge string.
+ *
+ * @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);
+ $parsed = array();
+ while (!empty($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] == '"') {
+ // We're in a quoted value
+ // Drop the first quote, since we don't care about it
+ $challenge=substr($challenge,1);
+ // Now explode() to the next quote, which is the end of our value
+ $val=explode('"',$challenge,2);
+ $challenge=$val[1]; // The rest of the challenge, work on it in next iteration of loop
+ $value=explode(',',$val[0]);
+ // Now, for those quoted values that are only 1 piece..
+ if (sizeof($value) == 1) {
+ $value=$value[0]; // Convert to non-array
+ }
+ } else {
+ // We're in a "simple" value - explode to next comma
+ $val=explode(',',$challenge,2);
+ if (isset($val[1])) {
+ $challenge=$val[1];
+ } else {
+ unset($challenge);
+ }
+ $value=$val[0];
+ }
+ $parsed["$key"]=$value;
+ } // End of while loop
+ return $parsed;
+}
+
+/**
+ * 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);
+
+ return $mhash;
+ }
+
+
+ // or, our own implementation...
+ //
+ if (!$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;
+
+}
+
+/**
+ * Fillin user and password based on SMTP auth settings.
+ *
+ * @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,
+ $smtp_sitewide_user, $smtp_sitewide_pass;
+
+ if ($smtp_auth_mech == 'none') {
+ $user = '';
+ $pass = '';
+ } elseif ( isset($smtp_sitewide_user) && isset($smtp_sitewide_pass) &&
+ !empty($smtp_sitewide_user)) {
+ $user = $smtp_sitewide_user;
+ $pass = $smtp_sitewide_pass;
+ } else {
+ $user = $username;
+ $pass = sqauth_read_password();
+ }
+
+ // 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);
+}