'basic'|'digest'|'basic digest' * 'realm' => * 'digest_domains' => Space-delimited list of URIs * 'nonce_timeout' => * 'use_opaque' => Whether to send the opaque value in the header * 'alogrithm' => See $_supportedAlgos. Default: MD5 * 'proxy_auth' => Whether to do authentication as a Proxy * @throws Zend_Auth_Adapter_Exception */ public function __construct(array $config) { if (!extension_loaded('hash')) { /** * @see Zend_Auth_Adapter_Exception */ #require_once 'Zend/Auth/Adapter/Exception.php'; throw new Zend_Auth_Adapter_Exception(__CLASS__ . ' requires the \'hash\' extension'); } $this->_request = null; $this->_response = null; $this->_ieNoOpaque = false; if (empty($config['accept_schemes'])) { /** * @see Zend_Auth_Adapter_Exception */ #require_once 'Zend/Auth/Adapter/Exception.php'; throw new Zend_Auth_Adapter_Exception('Config key \'accept_schemes\' is required'); } $schemes = explode(' ', $config['accept_schemes']); $this->_acceptSchemes = array_intersect($schemes, $this->_supportedSchemes); if (empty($this->_acceptSchemes)) { /** * @see Zend_Auth_Adapter_Exception */ #require_once 'Zend/Auth/Adapter/Exception.php'; throw new Zend_Auth_Adapter_Exception('No supported schemes given in \'accept_schemes\'. Valid values: ' . implode(', ', $this->_supportedSchemes)); } // Double-quotes are used to delimit the realm string in the HTTP header, // and colons are field delimiters in the password file. if (empty($config['realm']) || !ctype_print($config['realm']) || strpos($config['realm'], ':') !== false || strpos($config['realm'], '"') !== false) { /** * @see Zend_Auth_Adapter_Exception */ #require_once 'Zend/Auth/Adapter/Exception.php'; throw new Zend_Auth_Adapter_Exception('Config key \'realm\' is required, and must contain only printable ' . 'characters, excluding quotation marks and colons'); } else { $this->_realm = $config['realm']; } if (in_array('digest', $this->_acceptSchemes)) { if (empty($config['digest_domains']) || !ctype_print($config['digest_domains']) || strpos($config['digest_domains'], '"') !== false) { /** * @see Zend_Auth_Adapter_Exception */ #require_once 'Zend/Auth/Adapter/Exception.php'; throw new Zend_Auth_Adapter_Exception('Config key \'digest_domains\' is required, and must contain ' . 'only printable characters, excluding quotation marks'); } else { $this->_domains = $config['digest_domains']; } if (empty($config['nonce_timeout']) || !is_numeric($config['nonce_timeout'])) { /** * @see Zend_Auth_Adapter_Exception */ #require_once 'Zend/Auth/Adapter/Exception.php'; throw new Zend_Auth_Adapter_Exception('Config key \'nonce_timeout\' is required, and must be an ' . 'integer'); } else { $this->_nonceTimeout = (int) $config['nonce_timeout']; } // We use the opaque value unless explicitly told not to if (isset($config['use_opaque']) && false == (bool) $config['use_opaque']) { $this->_useOpaque = false; } else { $this->_useOpaque = true; } if (isset($config['algorithm']) && in_array($config['algorithm'], $this->_supportedAlgos)) { $this->_algo = $config['algorithm']; } else { $this->_algo = 'MD5'; } } // Don't be a proxy unless explicitly told to do so if (isset($config['proxy_auth']) && true == (bool) $config['proxy_auth']) { $this->_imaProxy = true; // I'm a Proxy } else { $this->_imaProxy = false; } } /** * Setter for the _basicResolver property * * @param Zend_Auth_Adapter_Http_Resolver_Interface $resolver * @return Zend_Auth_Adapter_Http Provides a fluent interface */ public function setBasicResolver(Zend_Auth_Adapter_Http_Resolver_Interface $resolver) { $this->_basicResolver = $resolver; return $this; } /** * Getter for the _basicResolver property * * @return Zend_Auth_Adapter_Http_Resolver_Interface */ public function getBasicResolver() { return $this->_basicResolver; } /** * Setter for the _digestResolver property * * @param Zend_Auth_Adapter_Http_Resolver_Interface $resolver * @return Zend_Auth_Adapter_Http Provides a fluent interface */ public function setDigestResolver(Zend_Auth_Adapter_Http_Resolver_Interface $resolver) { $this->_digestResolver = $resolver; return $this; } /** * Getter for the _digestResolver property * * @return Zend_Auth_Adapter_Http_Resolver_Interface */ public function getDigestResolver() { return $this->_digestResolver; } /** * Setter for the Request object * * @param Zend_Controller_Request_Http $request * @return Zend_Auth_Adapter_Http Provides a fluent interface */ public function setRequest(Zend_Controller_Request_Http $request) { $this->_request = $request; return $this; } /** * Getter for the Request object * * @return Zend_Controller_Request_Http */ public function getRequest() { return $this->_request; } /** * Setter for the Response object * * @param Zend_Controller_Response_Http $response * @return Zend_Auth_Adapter_Http Provides a fluent interface */ public function setResponse(Zend_Controller_Response_Http $response) { $this->_response = $response; return $this; } /** * Getter for the Response object * * @return Zend_Controller_Response_Http */ public function getResponse() { return $this->_response; } /** * Authenticate * * @throws Zend_Auth_Adapter_Exception * @return Zend_Auth_Result */ public function authenticate() { if (empty($this->_request) || empty($this->_response)) { /** * @see Zend_Auth_Adapter_Exception */ #require_once 'Zend/Auth/Adapter/Exception.php'; throw new Zend_Auth_Adapter_Exception('Request and Response objects must be set before calling ' . 'authenticate()'); } if ($this->_imaProxy) { $getHeader = 'Proxy-Authorization'; } else { $getHeader = 'Authorization'; } $authHeader = $this->_request->getHeader($getHeader); if (!$authHeader) { return $this->_challengeClient(); } list($clientScheme) = explode(' ', $authHeader); $clientScheme = strtolower($clientScheme); // The server can issue multiple challenges, but the client should // answer with only the selected auth scheme. if (!in_array($clientScheme, $this->_supportedSchemes)) { $this->_response->setHttpResponseCode(400); return new Zend_Auth_Result( Zend_Auth_Result::FAILURE_UNCATEGORIZED, array(), array('Client requested an incorrect or unsupported authentication scheme') ); } // client sent a scheme that is not the one required if (!in_array($clientScheme, $this->_acceptSchemes)) { // challenge again the client return $this->_challengeClient(); } switch ($clientScheme) { case 'basic': $result = $this->_basicAuth($authHeader); break; case 'digest': $result = $this->_digestAuth($authHeader); break; default: /** * @see Zend_Auth_Adapter_Exception */ #require_once 'Zend/Auth/Adapter/Exception.php'; throw new Zend_Auth_Adapter_Exception('Unsupported authentication scheme'); } return $result; } /** * Challenge Client * * Sets a 401 or 407 Unauthorized response code, and creates the * appropriate Authenticate header(s) to prompt for credentials. * * @return Zend_Auth_Result Always returns a non-identity Auth result */ protected function _challengeClient() { if ($this->_imaProxy) { $statusCode = 407; $headerName = 'Proxy-Authenticate'; } else { $statusCode = 401; $headerName = 'WWW-Authenticate'; } $this->_response->setHttpResponseCode($statusCode); // Send a challenge in each acceptable authentication scheme if (in_array('basic', $this->_acceptSchemes)) { $this->_response->setHeader($headerName, $this->_basicHeader()); } if (in_array('digest', $this->_acceptSchemes)) { $this->_response->setHeader($headerName, $this->_digestHeader()); } return new Zend_Auth_Result( Zend_Auth_Result::FAILURE_CREDENTIAL_INVALID, array(), array('Invalid or absent credentials; challenging client') ); } /** * Basic Header * * Generates a Proxy- or WWW-Authenticate header value in the Basic * authentication scheme. * * @return string Authenticate header value */ protected function _basicHeader() { return 'Basic realm="' . $this->_realm . '"'; } /** * Digest Header * * Generates a Proxy- or WWW-Authenticate header value in the Digest * authentication scheme. * * @return string Authenticate header value */ protected function _digestHeader() { $wwwauth = 'Digest realm="' . $this->_realm . '", ' . 'domain="' . $this->_domains . '", ' . 'nonce="' . $this->_calcNonce() . '", ' . ($this->_useOpaque ? 'opaque="' . $this->_calcOpaque() . '", ' : '') . 'algorithm="' . $this->_algo . '", ' . 'qop="' . implode(',', $this->_supportedQops) . '"'; return $wwwauth; } /** * Basic Authentication * * @param string $header Client's Authorization header * @throws Zend_Auth_Adapter_Exception * @return Zend_Auth_Result */ protected function _basicAuth($header) { if (empty($header)) { /** * @see Zend_Auth_Adapter_Exception */ #require_once 'Zend/Auth/Adapter/Exception.php'; throw new Zend_Auth_Adapter_Exception('The value of the client Authorization header is required'); } if (empty($this->_basicResolver)) { /** * @see Zend_Auth_Adapter_Exception */ #require_once 'Zend/Auth/Adapter/Exception.php'; throw new Zend_Auth_Adapter_Exception('A basicResolver object must be set before doing Basic ' . 'authentication'); } // Decode the Authorization header $auth = substr($header, strlen('Basic ')); $auth = base64_decode($auth); if (!$auth) { /** * @see Zend_Auth_Adapter_Exception */ #require_once 'Zend/Auth/Adapter/Exception.php'; throw new Zend_Auth_Adapter_Exception('Unable to base64_decode Authorization header value'); } // See ZF-1253. Validate the credentials the same way the digest // implementation does. If invalid credentials are detected, // re-challenge the client. if (!ctype_print($auth)) { return $this->_challengeClient(); } // Fix for ZF-1515: Now re-challenges on empty username or password $creds = array_filter(explode(':', $auth)); if (count($creds) != 2) { return $this->_challengeClient(); } $password = $this->_basicResolver->resolve($creds[0], $this->_realm); if ($password && $this->_secureStringCompare($password, $creds[1])) { $identity = array('username'=>$creds[0], 'realm'=>$this->_realm); return new Zend_Auth_Result(Zend_Auth_Result::SUCCESS, $identity); } else { return $this->_challengeClient(); } } /** * Digest Authentication * * @param string $header Client's Authorization header * @throws Zend_Auth_Adapter_Exception * @return Zend_Auth_Result Valid auth result only on successful auth */ protected function _digestAuth($header) { if (empty($header)) { /** * @see Zend_Auth_Adapter_Exception */ #require_once 'Zend/Auth/Adapter/Exception.php'; throw new Zend_Auth_Adapter_Exception('The value of the client Authorization header is required'); } if (empty($this->_digestResolver)) { /** * @see Zend_Auth_Adapter_Exception */ #require_once 'Zend/Auth/Adapter/Exception.php'; throw new Zend_Auth_Adapter_Exception('A digestResolver object must be set before doing Digest authentication'); } $data = $this->_parseDigestAuth($header); if ($data === false) { $this->_response->setHttpResponseCode(400); return new Zend_Auth_Result( Zend_Auth_Result::FAILURE_UNCATEGORIZED, array(), array('Invalid Authorization header format') ); } // See ZF-1052. This code was a bit too unforgiving of invalid // usernames. Now, if the username is bad, we re-challenge the client. if ('::invalid::' == $data['username']) { return $this->_challengeClient(); } // Verify that the client sent back the same nonce if ($this->_calcNonce() != $data['nonce']) { return $this->_challengeClient(); } // The opaque value is also required to match, but of course IE doesn't // play ball. if (!$this->_ieNoOpaque && $this->_calcOpaque() != $data['opaque']) { return $this->_challengeClient(); } // Look up the user's password hash. If not found, deny access. // This makes no assumptions about how the password hash was // constructed beyond that it must have been built in such a way as // to be recreatable with the current settings of this object. $ha1 = $this->_digestResolver->resolve($data['username'], $data['realm']); if ($ha1 === false) { return $this->_challengeClient(); } // If MD5-sess is used, a1 value is made of the user's password // hash with the server and client nonce appended, separated by // colons. if ($this->_algo == 'MD5-sess') { $ha1 = hash('md5', $ha1 . ':' . $data['nonce'] . ':' . $data['cnonce']); } // Calculate h(a2). The value of this hash depends on the qop // option selected by the client and the supported hash functions switch ($data['qop']) { case 'auth': $a2 = $this->_request->getMethod() . ':' . $data['uri']; break; case 'auth-int': // Should be REQUEST_METHOD . ':' . uri . ':' . hash(entity-body), // but this isn't supported yet, so fall through to default case default: /** * @see Zend_Auth_Adapter_Exception */ #require_once 'Zend/Auth/Adapter/Exception.php'; throw new Zend_Auth_Adapter_Exception('Client requested an unsupported qop option'); } // Using hash() should make parameterizing the hash algorithm // easier $ha2 = hash('md5', $a2); // Calculate the server's version of the request-digest. This must // match $data['response']. See RFC 2617, section 3.2.2.1 $message = $data['nonce'] . ':' . $data['nc'] . ':' . $data['cnonce'] . ':' . $data['qop'] . ':' . $ha2; $digest = hash('md5', $ha1 . ':' . $message); // If our digest matches the client's let them in, otherwise return // a 401 code and exit to prevent access to the protected resource. if ($this->_secureStringCompare($digest, $data['response'])) { $identity = array('username'=>$data['username'], 'realm'=>$data['realm']); return new Zend_Auth_Result(Zend_Auth_Result::SUCCESS, $identity); } else { return $this->_challengeClient(); } } /** * Calculate Nonce * * @return string The nonce value */ protected function _calcNonce() { // Once subtle consequence of this timeout calculation is that it // actually divides all of time into _nonceTimeout-sized sections, such // that the value of timeout is the point in time of the next // approaching "boundary" of a section. This allows the server to // consistently generate the same timeout (and hence the same nonce // value) across requests, but only as long as one of those // "boundaries" is not crossed between requests. If that happens, the // nonce will change on its own, and effectively log the user out. This // would be surprising if the user just logged in. $timeout = ceil(time() / $this->_nonceTimeout) * $this->_nonceTimeout; $nonce = hash('md5', $timeout . ':' . $this->_request->getServer('HTTP_USER_AGENT') . ':' . __CLASS__); return $nonce; } /** * Calculate Opaque * * The opaque string can be anything; the client must return it exactly as * it was sent. It may be useful to store data in this string in some * applications. Ideally, a new value for this would be generated each time * a WWW-Authenticate header is sent (in order to reduce predictability), * but we would have to be able to create the same exact value across at * least two separate requests from the same client. * * @return string The opaque value */ protected function _calcOpaque() { return hash('md5', 'Opaque Data:' . __CLASS__); } /** * Parse Digest Authorization header * * @param string $header Client's Authorization: HTTP header * @return array|false Data elements from header, or false if any part of * the header is invalid */ protected function _parseDigestAuth($header) { $temp = null; $data = array(); // See ZF-1052. Detect invalid usernames instead of just returning a // 400 code. $ret = preg_match('/username="([^"]+)"/', $header, $temp); if (!$ret || empty($temp[1]) || !ctype_print($temp[1]) || strpos($temp[1], ':') !== false) { $data['username'] = '::invalid::'; } else { $data['username'] = $temp[1]; } $temp = null; $ret = preg_match('/realm="([^"]+)"/', $header, $temp); if (!$ret || empty($temp[1])) { return false; } if (!ctype_print($temp[1]) || strpos($temp[1], ':') !== false) { return false; } else { $data['realm'] = $temp[1]; } $temp = null; $ret = preg_match('/nonce="([^"]+)"/', $header, $temp); if (!$ret || empty($temp[1])) { return false; } if (!ctype_xdigit($temp[1])) { return false; } else { $data['nonce'] = $temp[1]; } $temp = null; $ret = preg_match('/uri="([^"]+)"/', $header, $temp); if (!$ret || empty($temp[1])) { return false; } // Section 3.2.2.5 in RFC 2617 says the authenticating server must // verify that the URI field in the Authorization header is for the // same resource requested in the Request Line. $rUri = @parse_url($this->_request->getRequestUri()); $cUri = @parse_url($temp[1]); if (false === $rUri || false === $cUri) { return false; } else { // Make sure the path portion of both URIs is the same if ($rUri['path'] != $cUri['path']) { return false; } // Section 3.2.2.5 seems to suggest that the value of the URI // Authorization field should be made into an absolute URI if the // Request URI is absolute, but it's vague, and that's a bunch of // code I don't want to write right now. $data['uri'] = $temp[1]; } $temp = null; $ret = preg_match('/response="([^"]+)"/', $header, $temp); if (!$ret || empty($temp[1])) { return false; } if (32 != strlen($temp[1]) || !ctype_xdigit($temp[1])) { return false; } else { $data['response'] = $temp[1]; } $temp = null; // The spec says this should default to MD5 if omitted. OK, so how does // that square with the algo we send out in the WWW-Authenticate header, // if it can easily be overridden by the client? $ret = preg_match('/algorithm="?(' . $this->_algo . ')"?/', $header, $temp); if ($ret && !empty($temp[1]) && in_array($temp[1], $this->_supportedAlgos)) { $data['algorithm'] = $temp[1]; } else { $data['algorithm'] = 'MD5'; // = $this->_algo; ? } $temp = null; // Not optional in this implementation $ret = preg_match('/cnonce="([^"]+)"/', $header, $temp); if (!$ret || empty($temp[1])) { return false; } if (!ctype_print($temp[1])) { return false; } else { $data['cnonce'] = $temp[1]; } $temp = null; // If the server sent an opaque value, the client must send it back if ($this->_useOpaque) { $ret = preg_match('/opaque="([^"]+)"/', $header, $temp); if (!$ret || empty($temp[1])) { // Big surprise: IE isn't RFC 2617-compliant. if (false !== strpos($this->_request->getHeader('User-Agent'), 'MSIE')) { $temp[1] = ''; $this->_ieNoOpaque = true; } else { return false; } } // This implementation only sends MD5 hex strings in the opaque value if (!$this->_ieNoOpaque && (32 != strlen($temp[1]) || !ctype_xdigit($temp[1]))) { return false; } else { $data['opaque'] = $temp[1]; } $temp = null; } // Not optional in this implementation, but must be one of the supported // qop types $ret = preg_match('/qop="?(' . implode('|', $this->_supportedQops) . ')"?/', $header, $temp); if (!$ret || empty($temp[1])) { return false; } if (!in_array($temp[1], $this->_supportedQops)) { return false; } else { $data['qop'] = $temp[1]; } $temp = null; // Not optional in this implementation. The spec says this value // shouldn't be a quoted string, but apparently some implementations // quote it anyway. See ZF-1544. $ret = preg_match('/nc="?([0-9A-Fa-f]{8})"?/', $header, $temp); if (!$ret || empty($temp[1])) { return false; } if (8 != strlen($temp[1]) || !ctype_xdigit($temp[1])) { return false; } else { $data['nc'] = $temp[1]; } $temp = null; return $data; } /** * Securely compare two strings for equality while avoided C level memcmp() * optimisations capable of leaking timing information useful to an attacker * attempting to iteratively guess the unknown string (e.g. password) being * compared against. * * @param string $a * @param string $b * @return bool */ protected function _secureStringCompare($a, $b) { if (strlen($a) !== strlen($b)) { return false; } $result = 0; for ($i = 0; $i < strlen($a); $i++) { $result |= ord($a[$i]) ^ ord($b[$i]); } return $result == 0; } }