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Diffstat (limited to 'addon/statusnet/OAuth.php')
-rw-r--r-- | addon/statusnet/OAuth.php | 874 |
1 files changed, 874 insertions, 0 deletions
diff --git a/addon/statusnet/OAuth.php b/addon/statusnet/OAuth.php new file mode 100644 index 000000000..67a94c479 --- /dev/null +++ b/addon/statusnet/OAuth.php @@ -0,0 +1,874 @@ +<?php +// vim: foldmethod=marker + +/* Generic exception class + */ +class OAuthException extends Exception { + // pass +} + +class OAuthConsumer { + public $key; + public $secret; + + function __construct($key, $secret, $callback_url=NULL) { + $this->key = $key; + $this->secret = $secret; + $this->callback_url = $callback_url; + } + + function __toString() { + return "OAuthConsumer[key=$this->key,secret=$this->secret]"; + } +} + +class OAuthToken { + // access tokens and request tokens + public $key; + public $secret; + + /** + * key = the token + * secret = the token secret + */ + function __construct($key, $secret) { + $this->key = $key; + $this->secret = $secret; + } + + /** + * generates the basic string serialization of a token that a server + * would respond to request_token and access_token calls with + */ + function to_string() { + return "oauth_token=" . + OAuthUtil::urlencode_rfc3986($this->key) . + "&oauth_token_secret=" . + OAuthUtil::urlencode_rfc3986($this->secret); + } + + function __toString() { + return $this->to_string(); + } +} + +/** + * A class for implementing a Signature Method + * See section 9 ("Signing Requests") in the spec + */ +abstract class OAuthSignatureMethod { + /** + * Needs to return the name of the Signature Method (ie HMAC-SHA1) + * @return string + */ + abstract public function get_name(); + + /** + * Build up the signature + * NOTE: The output of this function MUST NOT be urlencoded. + * the encoding is handled in OAuthRequest when the final + * request is serialized + * @param OAuthRequest $request + * @param OAuthConsumer $consumer + * @param OAuthToken $token + * @return string + */ + abstract public function build_signature($request, $consumer, $token); + + /** + * Verifies that a given signature is correct + * @param OAuthRequest $request + * @param OAuthConsumer $consumer + * @param OAuthToken $token + * @param string $signature + * @return bool + */ + public function check_signature($request, $consumer, $token, $signature) { + $built = $this->build_signature($request, $consumer, $token); + return $built == $signature; + } +} + +/** + * The HMAC-SHA1 signature method uses the HMAC-SHA1 signature algorithm as defined in [RFC2104] + * where the Signature Base String is the text and the key is the concatenated values (each first + * encoded per Parameter Encoding) of the Consumer Secret and Token Secret, separated by an '&' + * character (ASCII code 38) even if empty. + * - Chapter 9.2 ("HMAC-SHA1") + */ +class OAuthSignatureMethod_HMAC_SHA1 extends OAuthSignatureMethod { + function get_name() { + return "HMAC-SHA1"; + } + + public function build_signature($request, $consumer, $token) { + $base_string = $request->get_signature_base_string(); + $request->base_string = $base_string; + + $key_parts = array( + $consumer->secret, + ($token) ? $token->secret : "" + ); + + $key_parts = OAuthUtil::urlencode_rfc3986($key_parts); + $key = implode('&', $key_parts); + + return base64_encode(hash_hmac('sha1', $base_string, $key, true)); + } +} + +/** + * The PLAINTEXT method does not provide any security protection and SHOULD only be used + * over a secure channel such as HTTPS. It does not use the Signature Base String. + * - Chapter 9.4 ("PLAINTEXT") + */ +class OAuthSignatureMethod_PLAINTEXT extends OAuthSignatureMethod { + public function get_name() { + return "PLAINTEXT"; + } + + /** + * oauth_signature is set to the concatenated encoded values of the Consumer Secret and + * Token Secret, separated by a '&' character (ASCII code 38), even if either secret is + * empty. The result MUST be encoded again. + * - Chapter 9.4.1 ("Generating Signatures") + * + * Please note that the second encoding MUST NOT happen in the SignatureMethod, as + * OAuthRequest handles this! + */ + public function build_signature($request, $consumer, $token) { + $key_parts = array( + $consumer->secret, + ($token) ? $token->secret : "" + ); + + $key_parts = OAuthUtil::urlencode_rfc3986($key_parts); + $key = implode('&', $key_parts); + $request->base_string = $key; + + return $key; + } +} + +/** + * The RSA-SHA1 signature method uses the RSASSA-PKCS1-v1_5 signature algorithm as defined in + * [RFC3447] section 8.2 (more simply known as PKCS#1), using SHA-1 as the hash function for + * EMSA-PKCS1-v1_5. It is assumed that the Consumer has provided its RSA public key in a + * verified way to the Service Provider, in a manner which is beyond the scope of this + * specification. + * - Chapter 9.3 ("RSA-SHA1") + */ +abstract class OAuthSignatureMethod_RSA_SHA1 extends OAuthSignatureMethod { + public function get_name() { + return "RSA-SHA1"; + } + + // Up to the SP to implement this lookup of keys. Possible ideas are: + // (1) do a lookup in a table of trusted certs keyed off of consumer + // (2) fetch via http using a url provided by the requester + // (3) some sort of specific discovery code based on request + // + // Either way should return a string representation of the certificate + protected abstract function fetch_public_cert(&$request); + + // Up to the SP to implement this lookup of keys. Possible ideas are: + // (1) do a lookup in a table of trusted certs keyed off of consumer + // + // Either way should return a string representation of the certificate + protected abstract function fetch_private_cert(&$request); + + public function build_signature($request, $consumer, $token) { + $base_string = $request->get_signature_base_string(); + $request->base_string = $base_string; + + // Fetch the private key cert based on the request + $cert = $this->fetch_private_cert($request); + + // Pull the private key ID from the certificate + $privatekeyid = openssl_get_privatekey($cert); + + // Sign using the key + $ok = openssl_sign($base_string, $signature, $privatekeyid); + + // Release the key resource + openssl_free_key($privatekeyid); + + return base64_encode($signature); + } + + public function check_signature($request, $consumer, $token, $signature) { + $decoded_sig = base64_decode($signature); + + $base_string = $request->get_signature_base_string(); + + // Fetch the public key cert based on the request + $cert = $this->fetch_public_cert($request); + + // Pull the public key ID from the certificate + $publickeyid = openssl_get_publickey($cert); + + // Check the computed signature against the one passed in the query + $ok = openssl_verify($base_string, $decoded_sig, $publickeyid); + + // Release the key resource + openssl_free_key($publickeyid); + + return $ok == 1; + } +} + +class OAuthRequest { + private $parameters; + private $http_method; + private $http_url; + // for debug purposes + public $base_string; + public static $version = '1.0'; + public static $POST_INPUT = 'php://input'; + + function __construct($http_method, $http_url, $parameters=NULL) { + @$parameters or $parameters = array(); + $parameters = array_merge( OAuthUtil::parse_parameters(parse_url($http_url, PHP_URL_QUERY)), $parameters); + $this->parameters = $parameters; + $this->http_method = $http_method; + $this->http_url = $http_url; + } + + + /** + * attempt to build up a request from what was passed to the server + */ + public static function from_request($http_method=NULL, $http_url=NULL, $parameters=NULL) { + $scheme = (!isset($_SERVER['HTTPS']) || $_SERVER['HTTPS'] != "on") + ? 'http' + : 'https'; + @$http_url or $http_url = $scheme . + '://' . $_SERVER['HTTP_HOST'] . + ':' . + $_SERVER['SERVER_PORT'] . + $_SERVER['REQUEST_URI']; + @$http_method or $http_method = $_SERVER['REQUEST_METHOD']; + + // We weren't handed any parameters, so let's find the ones relevant to + // this request. + // If you run XML-RPC or similar you should use this to provide your own + // parsed parameter-list + if (!$parameters) { + // Find request headers + $request_headers = OAuthUtil::get_headers(); + + // Parse the query-string to find GET parameters + $parameters = OAuthUtil::parse_parameters($_SERVER['QUERY_STRING']); + + // It's a POST request of the proper content-type, so parse POST + // parameters and add those overriding any duplicates from GET + if ($http_method == "POST" + && @strstr($request_headers["Content-Type"], + "application/x-www-form-urlencoded") + ) { + $post_data = OAuthUtil::parse_parameters( + file_get_contents(self::$POST_INPUT) + ); + $parameters = array_merge($parameters, $post_data); + } + + // We have a Authorization-header with OAuth data. Parse the header + // and add those overriding any duplicates from GET or POST + if (@substr($request_headers['Authorization'], 0, 6) == "OAuth ") { + $header_parameters = OAuthUtil::split_header( + $request_headers['Authorization'] + ); + $parameters = array_merge($parameters, $header_parameters); + } + + } + + return new OAuthRequest($http_method, $http_url, $parameters); + } + + /** + * pretty much a helper function to set up the request + */ + public static function from_consumer_and_token($consumer, $token, $http_method, $http_url, $parameters=NULL) { + @$parameters or $parameters = array(); + $defaults = array("oauth_version" => OAuthRequest::$version, + "oauth_nonce" => OAuthRequest::generate_nonce(), + "oauth_timestamp" => OAuthRequest::generate_timestamp(), + "oauth_consumer_key" => $consumer->key); + if ($token) + $defaults['oauth_token'] = $token->key; + + $parameters = array_merge($defaults, $parameters); + + return new OAuthRequest($http_method, $http_url, $parameters); + } + + public function set_parameter($name, $value, $allow_duplicates = true) { + if ($allow_duplicates && isset($this->parameters[$name])) { + // We have already added parameter(s) with this name, so add to the list + if (is_scalar($this->parameters[$name])) { + // This is the first duplicate, so transform scalar (string) + // into an array so we can add the duplicates + $this->parameters[$name] = array($this->parameters[$name]); + } + + $this->parameters[$name][] = $value; + } else { + $this->parameters[$name] = $value; + } + } + + public function get_parameter($name) { + return isset($this->parameters[$name]) ? $this->parameters[$name] : null; + } + + public function get_parameters() { + return $this->parameters; + } + + public function unset_parameter($name) { + unset($this->parameters[$name]); + } + + /** + * The request parameters, sorted and concatenated into a normalized string. + * @return string + */ + public function get_signable_parameters() { + // Grab all parameters + $params = $this->parameters; + + // Remove oauth_signature if present + // Ref: Spec: 9.1.1 ("The oauth_signature parameter MUST be excluded.") + if (isset($params['oauth_signature'])) { + unset($params['oauth_signature']); + } + + return OAuthUtil::build_http_query($params); + } + + /** + * Returns the base string of this request + * + * The base string defined as the method, the url + * and the parameters (normalized), each urlencoded + * and the concated with &. + */ + public function get_signature_base_string() { + $parts = array( + $this->get_normalized_http_method(), + $this->get_normalized_http_url(), + $this->get_signable_parameters() + ); + + $parts = OAuthUtil::urlencode_rfc3986($parts); + + return implode('&', $parts); + } + + /** + * just uppercases the http method + */ + public function get_normalized_http_method() { + return strtoupper($this->http_method); + } + + /** + * parses the url and rebuilds it to be + * scheme://host/path + */ + public function get_normalized_http_url() { + $parts = parse_url($this->http_url); + + $port = @$parts['port']; + $scheme = $parts['scheme']; + $host = $parts['host']; + $path = @$parts['path']; + + $port or $port = ($scheme == 'https') ? '443' : '80'; + + if (($scheme == 'https' && $port != '443') + || ($scheme == 'http' && $port != '80')) { + $host = "$host:$port"; + } + return "$scheme://$host$path"; + } + + /** + * builds a url usable for a GET request + */ + public function to_url() { + $post_data = $this->to_postdata(); + $out = $this->get_normalized_http_url(); + if ($post_data) { + $out .= '?'.$post_data; + } + return $out; + } + + /** + * builds the data one would send in a POST request + */ + public function to_postdata() { + return OAuthUtil::build_http_query($this->parameters); + } + + /** + * builds the Authorization: header + */ + public function to_header($realm=null) { + $first = true; + if($realm) { + $out = 'Authorization: OAuth realm="' . OAuthUtil::urlencode_rfc3986($realm) . '"'; + $first = false; + } else + $out = 'Authorization: OAuth'; + + $total = array(); + foreach ($this->parameters as $k => $v) { + if (substr($k, 0, 5) != "oauth") continue; + if (is_array($v)) { + throw new OAuthException('Arrays not supported in headers'); + } + $out .= ($first) ? ' ' : ','; + $out .= OAuthUtil::urlencode_rfc3986($k) . + '="' . + OAuthUtil::urlencode_rfc3986($v) . + '"'; + $first = false; + } + return $out; + } + + public function __toString() { + return $this->to_url(); + } + + + public function sign_request($signature_method, $consumer, $token) { + $this->set_parameter( + "oauth_signature_method", + $signature_method->get_name(), + false + ); + $signature = $this->build_signature($signature_method, $consumer, $token); + $this->set_parameter("oauth_signature", $signature, false); + } + + public function build_signature($signature_method, $consumer, $token) { + $signature = $signature_method->build_signature($this, $consumer, $token); + return $signature; + } + + /** + * util function: current timestamp + */ + private static function generate_timestamp() { + return time(); + } + + /** + * util function: current nonce + */ + private static function generate_nonce() { + $mt = microtime(); + $rand = mt_rand(); + + return md5($mt . $rand); // md5s look nicer than numbers + } +} + +class OAuthServer { + protected $timestamp_threshold = 300; // in seconds, five minutes + protected $version = '1.0'; // hi blaine + protected $signature_methods = array(); + + protected $data_store; + + function __construct($data_store) { + $this->data_store = $data_store; + } + + public function add_signature_method($signature_method) { + $this->signature_methods[$signature_method->get_name()] = + $signature_method; + } + + // high level functions + + /** + * process a request_token request + * returns the request token on success + */ + public function fetch_request_token(&$request) { + $this->get_version($request); + + $consumer = $this->get_consumer($request); + + // no token required for the initial token request + $token = NULL; + + $this->check_signature($request, $consumer, $token); + + // Rev A change + $callback = $request->get_parameter('oauth_callback'); + $new_token = $this->data_store->new_request_token($consumer, $callback); + + return $new_token; + } + + /** + * process an access_token request + * returns the access token on success + */ + public function fetch_access_token(&$request) { + $this->get_version($request); + + $consumer = $this->get_consumer($request); + + // requires authorized request token + $token = $this->get_token($request, $consumer, "request"); + + $this->check_signature($request, $consumer, $token); + + // Rev A change + $verifier = $request->get_parameter('oauth_verifier'); + $new_token = $this->data_store->new_access_token($token, $consumer, $verifier); + + return $new_token; + } + + /** + * verify an api call, checks all the parameters + */ + public function verify_request(&$request) { + $this->get_version($request); + $consumer = $this->get_consumer($request); + $token = $this->get_token($request, $consumer, "access"); + $this->check_signature($request, $consumer, $token); + return array($consumer, $token); + } + + // Internals from here + /** + * version 1 + */ + private function get_version(&$request) { + $version = $request->get_parameter("oauth_version"); + if (!$version) { + // Service Providers MUST assume the protocol version to be 1.0 if this parameter is not present. + // Chapter 7.0 ("Accessing Protected Ressources") + $version = '1.0'; + } + if ($version !== $this->version) { + throw new OAuthException("OAuth version '$version' not supported"); + } + return $version; + } + + /** + * figure out the signature with some defaults + */ + private function get_signature_method(&$request) { + $signature_method = + @$request->get_parameter("oauth_signature_method"); + + if (!$signature_method) { + // According to chapter 7 ("Accessing Protected Ressources") the signature-method + // parameter is required, and we can't just fallback to PLAINTEXT + throw new OAuthException('No signature method parameter. This parameter is required'); + } + + if (!in_array($signature_method, + array_keys($this->signature_methods))) { + throw new OAuthException( + "Signature method '$signature_method' not supported " . + "try one of the following: " . + implode(", ", array_keys($this->signature_methods)) + ); + } + return $this->signature_methods[$signature_method]; + } + + /** + * try to find the consumer for the provided request's consumer key + */ + private function get_consumer(&$request) { + $consumer_key = @$request->get_parameter("oauth_consumer_key"); + if (!$consumer_key) { + throw new OAuthException("Invalid consumer key"); + } + + $consumer = $this->data_store->lookup_consumer($consumer_key); + if (!$consumer) { + throw new OAuthException("Invalid consumer"); + } + + return $consumer; + } + + /** + * try to find the token for the provided request's token key + */ + private function get_token(&$request, $consumer, $token_type="access") { + $token_field = @$request->get_parameter('oauth_token'); + $token = $this->data_store->lookup_token( + $consumer, $token_type, $token_field + ); + if (!$token) { + throw new OAuthException("Invalid $token_type token: $token_field"); + } + return $token; + } + + /** + * all-in-one function to check the signature on a request + * should guess the signature method appropriately + */ + private function check_signature(&$request, $consumer, $token) { + // this should probably be in a different method + $timestamp = @$request->get_parameter('oauth_timestamp'); + $nonce = @$request->get_parameter('oauth_nonce'); + + $this->check_timestamp($timestamp); + $this->check_nonce($consumer, $token, $nonce, $timestamp); + + $signature_method = $this->get_signature_method($request); + + $signature = $request->get_parameter('oauth_signature'); + $valid_sig = $signature_method->check_signature( + $request, + $consumer, + $token, + $signature + ); + + if (!$valid_sig) { + throw new OAuthException("Invalid signature"); + } + } + + /** + * check that the timestamp is new enough + */ + private function check_timestamp($timestamp) { + if( ! $timestamp ) + throw new OAuthException( + 'Missing timestamp parameter. The parameter is required' + ); + + // verify that timestamp is recentish + $now = time(); + if (abs($now - $timestamp) > $this->timestamp_threshold) { + throw new OAuthException( + "Expired timestamp, yours $timestamp, ours $now" + ); + } + } + + /** + * check that the nonce is not repeated + */ + private function check_nonce($consumer, $token, $nonce, $timestamp) { + if( ! $nonce ) + throw new OAuthException( + 'Missing nonce parameter. The parameter is required' + ); + + // verify that the nonce is uniqueish + $found = $this->data_store->lookup_nonce( + $consumer, + $token, + $nonce, + $timestamp + ); + if ($found) { + throw new OAuthException("Nonce already used: $nonce"); + } + } + +} + +class OAuthDataStore { + function lookup_consumer($consumer_key) { + // implement me + } + + function lookup_token($consumer, $token_type, $token) { + // implement me + } + + function lookup_nonce($consumer, $token, $nonce, $timestamp) { + // implement me + } + + function new_request_token($consumer, $callback = null) { + // return a new token attached to this consumer + } + + function new_access_token($token, $consumer, $verifier = null) { + // return a new access token attached to this consumer + // for the user associated with this token if the request token + // is authorized + // should also invalidate the request token + } + +} + +class OAuthUtil { + public static function urlencode_rfc3986($input) { + if (is_array($input)) { + return array_map(array('OAuthUtil', 'urlencode_rfc3986'), $input); + } else if (is_scalar($input)) { + return str_replace( + '+', + ' ', + str_replace('%7E', '~', rawurlencode($input)) + ); + } else { + return ''; + } +} + + + // This decode function isn't taking into consideration the above + // modifications to the encoding process. However, this method doesn't + // seem to be used anywhere so leaving it as is. + public static function urldecode_rfc3986($string) { + return urldecode($string); + } + + // Utility function for turning the Authorization: header into + // parameters, has to do some unescaping + // Can filter out any non-oauth parameters if needed (default behaviour) + public static function split_header($header, $only_allow_oauth_parameters = true) { + $pattern = '/(([-_a-z]*)=("([^"]*)"|([^,]*)),?)/'; + $offset = 0; + $params = array(); + while (preg_match($pattern, $header, $matches, PREG_OFFSET_CAPTURE, $offset) > 0) { + $match = $matches[0]; + $header_name = $matches[2][0]; + $header_content = (isset($matches[5])) ? $matches[5][0] : $matches[4][0]; + if (preg_match('/^oauth_/', $header_name) || !$only_allow_oauth_parameters) { + $params[$header_name] = OAuthUtil::urldecode_rfc3986($header_content); + } + $offset = $match[1] + strlen($match[0]); + } + + if (isset($params['realm'])) { + unset($params['realm']); + } + + return $params; + } + + // helper to try to sort out headers for people who aren't running apache + public static function get_headers() { + if (function_exists('apache_request_headers')) { + // we need this to get the actual Authorization: header + // because apache tends to tell us it doesn't exist + $headers = apache_request_headers(); + + // sanitize the output of apache_request_headers because + // we always want the keys to be Cased-Like-This and arh() + // returns the headers in the same case as they are in the + // request + $out = array(); + foreach( $headers AS $key => $value ) { + $key = str_replace( + " ", + "-", + ucwords(strtolower(str_replace("-", " ", $key))) + ); + $out[$key] = $value; + } + } else { + // otherwise we don't have apache and are just going to have to hope + // that $_SERVER actually contains what we need + $out = array(); + if( isset($_SERVER['CONTENT_TYPE']) ) + $out['Content-Type'] = $_SERVER['CONTENT_TYPE']; + if( isset($_ENV['CONTENT_TYPE']) ) + $out['Content-Type'] = $_ENV['CONTENT_TYPE']; + + foreach ($_SERVER as $key => $value) { + if (substr($key, 0, 5) == "HTTP_") { + // this is chaos, basically it is just there to capitalize the first + // letter of every word that is not an initial HTTP and strip HTTP + // code from przemek + $key = str_replace( + " ", + "-", + ucwords(strtolower(str_replace("_", " ", substr($key, 5)))) + ); + $out[$key] = $value; + } + } + } + return $out; + } + + // This function takes a input like a=b&a=c&d=e and returns the parsed + // parameters like this + // array('a' => array('b','c'), 'd' => 'e') + public static function parse_parameters( $input ) { + if (!isset($input) || !$input) return array(); + + $pairs = explode('&', $input); + + $parsed_parameters = array(); + foreach ($pairs as $pair) { + $split = explode('=', $pair, 2); + $parameter = OAuthUtil::urldecode_rfc3986($split[0]); + $value = isset($split[1]) ? OAuthUtil::urldecode_rfc3986($split[1]) : ''; + + if (isset($parsed_parameters[$parameter])) { + // We have already recieved parameter(s) with this name, so add to the list + // of parameters with this name + + if (is_scalar($parsed_parameters[$parameter])) { + // This is the first duplicate, so transform scalar (string) into an array + // so we can add the duplicates + $parsed_parameters[$parameter] = array($parsed_parameters[$parameter]); + } + + $parsed_parameters[$parameter][] = $value; + } else { + $parsed_parameters[$parameter] = $value; + } + } + return $parsed_parameters; + } + + public static function build_http_query($params) { + if (!$params) return ''; + + // Urlencode both keys and values + $keys = OAuthUtil::urlencode_rfc3986(array_keys($params)); + $values = OAuthUtil::urlencode_rfc3986(array_values($params)); + $params = array_combine($keys, $values); + + // Parameters are sorted by name, using lexicographical byte value ordering. + // Ref: Spec: 9.1.1 (1) + uksort($params, 'strcmp'); + + $pairs = array(); + foreach ($params as $parameter => $value) { + if (is_array($value)) { + // If two or more parameters share the same name, they are sorted by their value + // Ref: Spec: 9.1.1 (1) + natsort($value); + foreach ($value as $duplicate_value) { + $pairs[] = $parameter . '=' . $duplicate_value; + } + } else { + $pairs[] = $parameter . '=' . $value; + } + } + // For each parameter, the name is separated from the corresponding value by an '=' character (ASCII code 61) + // Each name-value pair is separated by an '&' character (ASCII code 38) + return implode('&', $pairs); + } +} + +?> |