]> git.mxchange.org Git - friendica-addons.git/blobdiff - statusnet/library/OAuth1.php
Move StatusNet addon dependencies in own library subfolder
[friendica-addons.git] / statusnet / library / OAuth1.php
diff --git a/statusnet/library/OAuth1.php b/statusnet/library/OAuth1.php
new file mode 100644 (file)
index 0000000..57481f5
--- /dev/null
@@ -0,0 +1,891 @@
+<?php
+// vim: foldmethod=marker
+
+/* Generic exception class
+ */
+if (!class_exists('OAuthException')) {
+       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;
+
+         public $expires;
+         public $scope;
+         public $uid;
+
+         /**
+          * key = the token
+          * secret = the token secret
+          */
+         function __construct($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, $token);
+               //echo "<pre>"; var_dump($signature, $built, ($built == $signature)); killme();
+               return ($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);
+
+
+               $r = base64_encode(hash_hmac('sha1', $base_string, $key, true));
+               return $r;
+         }
+       }
+
+       /**
+        * The PLAINTEXT method does not provide any security protection and SHOULD only be used
+        * over a secure channel such as HTTPS. It does not use the Signature Base String.
+        *   - Chapter 9.4 ("PLAINTEXT")
+        */
+       class OAuthSignatureMethod_PLAINTEXT extends OAuthSignatureMethod {
+         public function get_name() {
+               return "PLAINTEXT";
+         }
+
+         /**
+          * oauth_signature is set to the concatenated encoded values of the Consumer Secret and
+          * Token Secret, separated by a '&' character (ASCII code 38), even if either secret is
+          * empty. The result MUST be encoded again.
+          *   - Chapter 9.4.1 ("Generating Signatures")
+          *
+          * Please note that the second encoding MUST NOT happen in the SignatureMethod, as
+          * OAuthRequest handles this!
+          */
+         public function build_signature($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);
+                 }
+
+               }
+               // fix for friendica redirect system
+
+               $http_url =  substr($http_url, 0, strpos($http_url,$parameters['pagename'])+strlen($parameters['pagename']));
+               unset( $parameters['pagename'] );
+
+               //echo "<pre>".__function__."\n"; var_dump($http_method, $http_url, $parameters, $_SERVER['REQUEST_URI']); killme();
+               return new OAuthRequest($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 $out;
+         }
+
+         /**
+          * builds the data one would send in a POST request
+          */
+         public function to_postdata($raw = false) {
+               if ($raw)
+                 return($this->parameters);
+               else
+                 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);
+               //echo __file__.__line__.__function__."<pre>"; var_dump($consumer); die();
+               $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);
+         }
+       }
+}