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Diffstat (limited to 'program/lib/Auth/SASL/SCRAM.php')
| -rw-r--r-- | program/lib/Auth/SASL/SCRAM.php | 306 |
1 files changed, 0 insertions, 306 deletions
diff --git a/program/lib/Auth/SASL/SCRAM.php b/program/lib/Auth/SASL/SCRAM.php deleted file mode 100644 index cbca500e4..000000000 --- a/program/lib/Auth/SASL/SCRAM.php +++ /dev/null @@ -1,306 +0,0 @@ -<?php -// +-----------------------------------------------------------------------+ -// | Copyright (c) 2011 Jehan | -// | All rights reserved. | -// | | -// | Redistribution and use in source and binary forms, with or without | -// | modification, are permitted provided that the following conditions | -// | are met: | -// | | -// | o Redistributions of source code must retain the above copyright | -// | notice, this list of conditions and the following disclaimer. | -// | o Redistributions in binary form must reproduce the above copyright | -// | notice, this list of conditions and the following disclaimer in the | -// | documentation and/or other materials provided with the distribution.| -// | o The names of the authors may not be used to endorse or promote | -// | products derived from this software without specific prior written | -// | permission. | -// | | -// | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | -// | "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | -// | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | -// | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | -// | OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | -// | SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | -// | LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | -// | DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | -// | THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | -// | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | -// | OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | -// | | -// +-----------------------------------------------------------------------+ -// | Author: Jehan <jehan.marmottard@gmail.com | -// +-----------------------------------------------------------------------+ -// -// $Id$ - -/** -* Implementation of SCRAM-* SASL mechanisms. -* SCRAM mechanisms have 3 main steps (initial response, response to the server challenge, then server signature -* verification) which keep state-awareness. Therefore a single class instanciation must be done and reused for the whole -* authentication process. -* -* @author Jehan <jehan.marmottard@gmail.com> -* @access public -* @version 1.0 -* @package Auth_SASL -*/ - -require_once('Auth/SASL/Common.php'); - -class Auth_SASL_SCRAM extends Auth_SASL_Common -{ - /** - * Construct a SCRAM-H client where 'H' is a cryptographic hash function. - * - * @param string $hash The name cryptographic hash function 'H' as registered by IANA in the "Hash Function Textual - * Names" registry. - * @link http://www.iana.org/assignments/hash-function-text-names/hash-function-text-names.xml "Hash Function Textual - * Names" - * format of core PHP hash function. - * @access public - */ - function __construct($hash) - { - // Though I could be strict, I will actually also accept the naming used in the PHP core hash framework. - // For instance "sha1" is accepted, while the registered hash name should be "SHA-1". - $hash = strtolower($hash); - $hashes = array('md2' => 'md2', - 'md5' => 'md5', - 'sha-1' => 'sha1', - 'sha1' => 'sha1', - 'sha-224' > 'sha224', - 'sha224' > 'sha224', - 'sha-256' => 'sha256', - 'sha256' => 'sha256', - 'sha-384' => 'sha384', - 'sha384' => 'sha384', - 'sha-512' => 'sha512', - 'sha512' => 'sha512'); - if (function_exists('hash_hmac') && isset($hashes[$hash])) - { - $this->hash = create_function('$data', 'return hash("' . $hashes[$hash] . '", $data, TRUE);'); - $this->hmac = create_function('$key,$str,$raw', 'return hash_hmac("' . $hashes[$hash] . '", $str, $key, $raw);'); - } - elseif ($hash == 'md5') - { - $this->hash = create_function('$data', 'return md5($data, true);'); - $this->hmac = array($this, '_HMAC_MD5'); - } - elseif (in_array($hash, array('sha1', 'sha-1'))) - { - $this->hash = create_function('$data', 'return sha1($data, true);'); - $this->hmac = array($this, '_HMAC_SHA1'); - } - else - return PEAR::raiseError('Invalid SASL mechanism type'); - } - - /** - * Provides the (main) client response for SCRAM-H. - * - * @param string $authcid Authentication id (username) - * @param string $pass Password - * @param string $challenge The challenge sent by the server. - * If the challenge is NULL or an empty string, the result will be the "initial response". - * @param string $authzid Authorization id (username to proxy as) - * @return string|false The response (binary, NOT base64 encoded) - * @access public - */ - public function getResponse($authcid, $pass, $challenge = NULL, $authzid = NULL) - { - $authcid = $this->_formatName($authcid); - if (empty($authcid)) - { - return false; - } - if (!empty($authzid)) - { - $authzid = $this->_formatName($authzid); - if (empty($authzid)) - { - return false; - } - } - - if (empty($challenge)) - { - return $this->_generateInitialResponse($authcid, $authzid); - } - else - { - return $this->_generateResponse($challenge, $pass); - } - - } - - /** - * Prepare a name for inclusion in a SCRAM response. - * - * @param string $username a name to be prepared. - * @return string the reformated name. - * @access private - */ - private function _formatName($username) - { - // TODO: prepare through the SASLprep profile of the stringprep algorithm. - // See RFC-4013. - - $username = str_replace('=', '=3D', $username); - $username = str_replace(',', '=2C', $username); - return $username; - } - - /** - * Generate the initial response which can be either sent directly in the first message or as a response to an empty - * server challenge. - * - * @param string $authcid Prepared authentication identity. - * @param string $authzid Prepared authorization identity. - * @return string The SCRAM response to send. - * @access private - */ - private function _generateInitialResponse($authcid, $authzid) - { - $init_rep = ''; - $gs2_cbind_flag = 'n,'; // TODO: support channel binding. - $this->gs2_header = $gs2_cbind_flag . (!empty($authzid)? 'a=' . $authzid : '') . ','; - - // I must generate a client nonce and "save" it for later comparison on second response. - $this->cnonce = $this->_getCnonce(); - // XXX: in the future, when mandatory and/or optional extensions are defined in any updated RFC, - // this message can be updated. - $this->first_message_bare = 'n=' . $authcid . ',r=' . $this->cnonce; - return $this->gs2_header . $this->first_message_bare; - } - - /** - * Parses and verifies a non-empty SCRAM challenge. - * - * @param string $challenge The SCRAM challenge - * @return string|false The response to send; false in case of wrong challenge or if an initial response has not - * been generated first. - * @access private - */ - private function _generateResponse($challenge, $password) - { - // XXX: as I don't support mandatory extension, I would fail on them. - // And I simply ignore any optional extension. - $server_message_regexp = "#^r=([\x21-\x2B\x2D-\x7E]+),s=((?:[A-Za-z0-9/+]{4})*(?:[A-Za-z0-9]{3}=|[A-Xa-z0-9]{2}==)?),i=([0-9]*)(,[A-Za-z]=[^,])*$#"; - if (!isset($this->cnonce, $this->gs2_header) - || !preg_match($server_message_regexp, $challenge, $matches)) - { - return false; - } - $nonce = $matches[1]; - $salt = base64_decode($matches[2]); - if (!$salt) - { - // Invalid Base64. - return false; - } - $i = intval($matches[3]); - - $cnonce = substr($nonce, 0, strlen($this->cnonce)); - if ($cnonce <> $this->cnonce) - { - // Invalid challenge! Are we under attack? - return false; - } - - $channel_binding = 'c=' . base64_encode($this->gs2_header); // TODO: support channel binding. - $final_message = $channel_binding . ',r=' . $nonce; // XXX: no extension. - - // TODO: $password = $this->normalize($password); // SASLprep profile of stringprep. - $saltedPassword = $this->hi($password, $salt, $i); - $this->saltedPassword = $saltedPassword; - $clientKey = call_user_func($this->hmac, $saltedPassword, "Client Key", TRUE); - $storedKey = call_user_func($this->hash, $clientKey, TRUE); - $authMessage = $this->first_message_bare . ',' . $challenge . ',' . $final_message; - $this->authMessage = $authMessage; - $clientSignature = call_user_func($this->hmac, $storedKey, $authMessage, TRUE); - $clientProof = $clientKey ^ $clientSignature; - $proof = ',p=' . base64_encode($clientProof); - - return $final_message . $proof; - } - - /** - * SCRAM has also a server verification step. On a successful outcome, it will send additional data which must - * absolutely be checked against this function. If this fails, the entity which we are communicating with is probably - * not the server as it has not access to your ServerKey. - * - * @param string $data The additional data sent along a successful outcome. - * @return bool Whether the server has been authenticated. - * If false, the client must close the connection and consider to be under a MITM attack. - * @access public - */ - public function processOutcome($data) - { - $verifier_regexp = '#^v=((?:[A-Za-z0-9/+]{4})*(?:[A-Za-z0-9]{3}=|[A-Xa-z0-9]{2}==)?)$#'; - if (!isset($this->saltedPassword, $this->authMessage) - || !preg_match($verifier_regexp, $data, $matches)) - { - // This cannot be an outcome, you never sent the challenge's response. - return false; - } - - $verifier = $matches[1]; - $proposed_serverSignature = base64_decode($verifier); - $serverKey = call_user_func($this->hmac, $this->saltedPassword, "Server Key", true); - $serverSignature = call_user_func($this->hmac, $serverKey, $this->authMessage, TRUE); - return ($proposed_serverSignature === $serverSignature); - } - - /** - * Hi() call, which is essentially PBKDF2 (RFC-2898) with HMAC-H() as the pseudorandom function. - * - * @param string $str The string to hash. - * @param string $hash The hash value. - * @param int $i The iteration count. - * @access private - */ - private function hi($str, $salt, $i) - { - $int1 = "\0\0\0\1"; - $ui = call_user_func($this->hmac, $str, $salt . $int1, true); - $result = $ui; - for ($k = 1; $k < $i; $k++) - { - $ui = call_user_func($this->hmac, $str, $ui, true); - $result = $result ^ $ui; - } - return $result; - } - - - /** - * Creates the client nonce for the response - * - * @return string The cnonce value - * @access private - * @author Richard Heyes <richard@php.net> - */ - private function _getCnonce() - { - // TODO: I reused the nonce function from the DigestMD5 class. - // I should probably make this a protected function in Common. - if (@file_exists('/dev/urandom') && $fd = @fopen('/dev/urandom', 'r')) { - return base64_encode(fread($fd, 32)); - - } elseif (@file_exists('/dev/random') && $fd = @fopen('/dev/random', 'r')) { - return base64_encode(fread($fd, 32)); - - } else { - $str = ''; - for ($i=0; $i<32; $i++) { - $str .= chr(mt_rand(0, 255)); - } - - return base64_encode($str); - } - } - -} - -?> |