Upgrade OAuth.php to the latest version.

1 files changed, 516 insertions, 426 deletions

diff --git a/extlib/OAuth.php b/extlib/OAuth.php
index 04984d5fa..e9c4bdfae 100644
--- a/extlib/OAuth.php
+++ b/extlib/OAuth.php
@@ -3,26 +3,26 @@
 
 /* Generic exception class
  */
-class OAuthException extends Exception {/*{{{*/
+class OAuthException extends Exception {
   // pass
-}/*}}}*/
+}
 
-class OAuthConsumer {/*{{{*/
+class OAuthConsumer {
   public $key;
   public $secret;
 
-  function __construct($key, $secret, $callback_url=NULL) {/*{{{*/
+  function __construct($key, $secret, $callback_url=NULL) {
     $this->key = $key;
     $this->secret = $secret;
     $this->callback_url = $callback_url;
-  }/*}}}*/
+  }
 
-  function __toString() {/*{{{*/
+  function __toString() {
     return "OAuthConsumer[key=$this->key,secret=$this->secret]";
-  }/*}}}*/
-}/*}}}*/
+  }
+}
 
-class OAuthToken {/*{{{*/
+class OAuthToken {
   // access tokens and request tokens
   public $key;
   public $secret;
@@ -31,56 +31,77 @@ class OAuthToken {/*{{{*/
    * key = the token
    * secret = the token secret
    */
-  function __construct($key, $secret) {/*{{{*/
+  function __construct($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 to_string() {
+    return "oauth_token=" .
+           OAuthUtil::urlencode_rfc3986($this->key) .
+           "&oauth_token_secret=" .
+           OAuthUtil::urlencode_rfc3986($this->secret);
+  }
 
-  function __toString() {/*{{{*/
+  function __toString() {
     return $this->to_string();
-  }/*}}}*/
-}/*}}}*/
-
-class OAuthSignatureMethod {/*{{{*/
-  public function check_signature(&$request, $consumer, $token, $signature) {
-    $built = $this->build_signature($request, $consumer, $token);
-    return $built == $signature;
-
-    // Check for zero length, although unlikely here
-    if (strlen($built) == 0 || strlen($signature) == 0) {
-      return false;
-    }
-
-    if (strlen($built) != strlen($signature)) {
-      return false;
-    }
+  }
+}
 
-    $result = 0;
+/**
+ * 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();
 
-    // Avoid a timing leak with a (hopefully) time insensitive compare
-    for ($i = 0; $i < strlen($signature); $i++) {
-      $result |= ord($built{$i}) ^ ord($signature{$i});
-    }
+  /**
+   * 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);
 
-    return $result == 0;
+  /**
+   * 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;
   }
-}/*}}}*/
-
-class OAuthSignatureMethod_HMAC_SHA1 extends OAuthSignatureMethod {/*{{{*/
-  function get_name() {/*{{{*/
+}
+
+/**
+ * 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, $token) {/*{{{*/
+  public function build_signature($request, $consumer, $token) {
     $base_string = $request->get_signature_base_string();
     $request->base_string = $base_string;
 
@@ -92,61 +113,74 @@ class OAuthSignatureMethod_HMAC_SHA1 extends OAuthSignatureMethod {/*{{{*/
     $key_parts = OAuthUtil::urlencode_rfc3986($key_parts);
     $key = implode('&', $key_parts);
 
-    return base64_encode( hash_hmac('sha1', $base_string, $key, true));
-  }/*}}}*/
-}/*}}}*/
+    return base64_encode(hash_hmac('sha1', $base_string, $key, true));
+  }
+}
 
-class OAuthSignatureMethod_PLAINTEXT extends OAuthSignatureMethod {/*{{{*/
-  public function get_name() {/*{{{*/
+/**
+ * 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";
-  }/*}}}*/
+  }
 
-  public function build_signature($request, $consumer, $token) {/*{{{*/
-    $sig = array(
-      OAuthUtil::urlencode_rfc3986($consumer->secret)
+  /**
+   * 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 : ""
     );
 
-    if ($token) {
-      array_push($sig, OAuthUtil::urlencode_rfc3986($token->secret));
-    } else {
-      array_push($sig, '');
-    }
-
-    $raw = implode("&", $sig);
-    // for debug purposes
-    $request->base_string = $raw;
-
-    return OAuthUtil::urlencode_rfc3986($raw);
-  }/*}}}*/
-}/*}}}*/
+    $key_parts = OAuthUtil::urlencode_rfc3986($key_parts);
+    $key = implode('&', $key_parts);
+    $request->base_string = $key;
 
-class OAuthSignatureMethod_RSA_SHA1 extends OAuthSignatureMethod {/*{{{*/
-  public function get_name() {/*{{{*/
+    return $key;
+  }
+}
+
+/**
+ * The RSA-SHA1 signature method uses the RSASSA-PKCS1-v1_5 signature algorithm as defined in 
+ * [RFC3447] section 8.2 (more simply known as PKCS#1), using SHA-1 as the hash function for 
+ * EMSA-PKCS1-v1_5. It is assumed that the Consumer has provided its RSA public key in a 
+ * verified way to the Service Provider, in a manner which is beyond the scope of this 
+ * specification.
+ *   - Chapter 9.3 ("RSA-SHA1")
+ */
+abstract class OAuthSignatureMethod_RSA_SHA1 extends OAuthSignatureMethod {
+  public function get_name() {
     return "RSA-SHA1";
-  }/*}}}*/
-
-  protected function fetch_public_cert(&$request) {/*{{{*/
-    // not implemented yet, 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
-    throw Exception("fetch_public_cert not implemented");
-  }/*}}}*/
-
-  protected function fetch_private_cert(&$request) {/*{{{*/
-    // not implemented yet, ideas are:
-    // (1) do a lookup in a table of trusted certs keyed off of consumer
-    //
-    // either way should return a string representation of the certificate
-    throw Exception("fetch_private_cert not implemented");
-  }/*}}}*/
-
-  public function build_signature(&$request, $consumer, $token) {/*{{{*/
+  }
+
+  // Up to the SP to implement this lookup of keys. Possible ideas are:
+  // (1) do a lookup in a table of trusted certs keyed off of consumer
+  // (2) fetch via http using a url provided by the requester
+  // (3) some sort of specific discovery code based on request
+  //
+  // Either way should return a string representation of the certificate
+  protected abstract function fetch_public_cert(&$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);
 
@@ -154,19 +188,19 @@ class OAuthSignatureMethod_RSA_SHA1 extends OAuthSignatureMethod {/*{{{*/
     $privatekeyid = openssl_get_privatekey($cert);
 
     // Sign using the key
-    $ok = openssl_sign($base_string, $signature, $privatekeyid);   
+    $ok = openssl_sign($base_string, $signature, $privatekeyid);
 
     // Release the key resource
     openssl_free_key($privatekeyid);
-  
+
     return base64_encode($signature);
-  } /*}}}*/
+  }
 
-  public function check_signature(&$request, $consumer, $token, $signature) {/*{{{*/
+  public function check_signature($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);
 
@@ -174,143 +208,145 @@ class OAuthSignatureMethod_RSA_SHA1 extends OAuthSignatureMethod {/*{{{*/
     $publickeyid = openssl_get_publickey($cert);
 
     // Check the computed signature against the one passed in the query
-    $ok = openssl_verify($base_string, $decoded_sig, $publickeyid);   
+    $ok = openssl_verify($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;
+class OAuthRequest {
+  protected $parameters;
+  protected $http_method;
+  protected $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 $parameters = array();
+  function __construct($http_method, $http_url, $parameters=NULL) {
+    $parameters = ($parameters) ? $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'];
-    
-    $request_headers = OAuthRequest::get_headers();
+  public static function from_request($http_method=NULL, $http_url=NULL, $parameters=NULL) {
+    $scheme = (!isset($_SERVER['HTTPS']) || $_SERVER['HTTPS'] != "on")
+              ? 'http'
+              : 'https';
+    $http_url = ($http_url) ? $http_url : $scheme .
+                              '://' . $_SERVER['HTTP_HOST'] .
+                              ':' .
+                              $_SERVER['SERVER_PORT'] .
+                              $_SERVER['REQUEST_URI'];
+    $http_method = ($http_method) ? $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 ($http_method == "POST"
+          &&  isset($request_headers['Content-Type'])
+          && 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);
+      }
 
-    // let the library user override things however they'd like, if they know
-    // which parameters to use then go for it, for example XMLRPC might want to
-    // do this
-    if ($parameters) {
-      $req = new OAuthRequest($http_method, $http_url, $parameters);
-    } else {
-      // collect request parameters from query string (GET) and post-data (POST) if appropriate (note: POST vars have priority)
-      $req_parameters = $_GET;
-      if ($http_method == "POST" &&
-        ( @strstr($request_headers["Content-Type"], "application/x-www-form-urlencoded") || @strstr($_ENV["CONTENT_TYPE"], "application/x-www-form-urlencoded") )) {
-        $req_parameters = array_merge($req_parameters, $_POST);
+      // We have a Authorization-header with OAuth data. Parse the header
+      // and add those overriding any duplicates from GET or POST
+      if (isset($request_headers['Authorization']) && substr($request_headers['Authorization'], 0, 6) == 'OAuth ') {
+        $header_parameters = OAuthUtil::split_header(
+          $request_headers['Authorization']
+        );
+        $parameters = array_merge($parameters, $header_parameters);
       }
 
-      // next check for the auth header, we need to do some extra stuff
-      // if that is the case, namely suck in the parameters from GET or POST
-      // so that we can include them in the signature
-      if (@substr($request_headers['Authorization'], 0, 6) == "OAuth ") {
-        $header_parameters = OAuthRequest::split_header($request_headers['Authorization']);
-        $parameters = array_merge($req_parameters, $header_parameters);
-        $req = new OAuthRequest($http_method, $http_url, $parameters);
-      } else $req = new OAuthRequest($http_method, $http_url, $req_parameters);
     }
 
-    return $req;
-  }/*}}}*/
+    return new OAuthRequest($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 $parameters = array();
+  public static function from_consumer_and_token($consumer, $token, $http_method, $http_url, $parameters=NULL) {
+    $parameters = ($parameters) ?  $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);
 
-    if ($token) {
-      $parameters['oauth_token'] = $token->key;
-    }
     return new OAuthRequest($http_method, $http_url, $parameters);
-  }/*}}}*/
+  }
 
-  public function set_parameter($name, $value) {/*{{{*/
-    $this->parameters[$name] = $value;
-  }/*}}}*/
+  public function set_parameter($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]);
+      }
 
-  public function get_parameter($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() {/*{{{*/
+  public function get_parameters() {
     return $this->parameters;
-  }/*}}}*/
+  }
+
+  public function unset_parameter($name) {
+    unset($this->parameters[$name]);
+  }
 
   /**
-   * Returns the normalized parameters of the request
-   * 
-   * This will be all (except oauth_signature) parameters,
-   * sorted first by key, and if duplicate keys, then by
-   * value.
-   *
-   * The returned string will be all the key=value pairs
-   * concated by &.
-   * 
+   * The request parameters, sorted and concatenated into a normalized string.
    * @return string
    */
-  public function get_signable_parameters() {/*{{{*/
+  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']);
     }
-		
-    // Urlencode both keys and values
-    $keys = OAuthUtil::urlencode_rfc3986(array_keys($params));
-    $values = OAuthUtil::urlencode_rfc3986(array_values($params));
-    $params = array_combine($keys, $values);
-
-    // Sort by keys (natsort)
-    uksort($params, 'strcmp');
 
-    // Generate key=value pairs
-    $pairs = array();
-    foreach ($params as $key=>$value ) {
-      if (is_array($value)) {
-        // If the value is an array, it's because there are multiple 
-        // with the same key, sort them, then add all the pairs
-        natsort($value);
-        foreach ($value as $v2) {
-          $pairs[] = $key . '=' . $v2;
-        }
-      } else {
-        $pairs[] = $key . '=' . $value;
-      }
-    }
-		
-    // Return the pairs, concated with &
-    return implode('&', $pairs);
-  }/*}}}*/
+    return OAuthUtil::build_http_query($params);
+  }
 
   /**
    * Returns the base string of this request
@@ -319,7 +355,7 @@ class OAuthRequest {/*{{{*/
    * and the parameters (normalized), each urlencoded
    * and the concated with &.
    */
-  public function get_signature_base_string() {/*{{{*/
+  public function get_signature_base_string() {
     $parts = array(
       $this->get_normalized_http_method(),
       $this->get_normalized_http_url(),
@@ -329,185 +365,141 @@ class OAuthRequest {/*{{{*/
     $parts = OAuthUtil::urlencode_rfc3986($parts);
 
     return implode('&', $parts);
-  }/*}}}*/
+  }
 
   /**
    * just uppercases the http method
    */
-  public function get_normalized_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() {/*{{{*/
+  public function get_normalized_http_url() {
     $parts = parse_url($this->http_url);
 
-    $port = isset($parts['port']) ? $parts['port'] : null;
-    $scheme = $parts['scheme'];
-    $host = $parts['host'];
-    $path = @$parts['path'];
-
-    $port or $port = ($scheme == 'https') ? '443' : '80';
+    $scheme = (isset($parts['scheme'])) ? $parts['scheme'] : 'http';
+    $port = (isset($parts['port'])) ? $parts['port'] : (($scheme == 'https') ? '443' : '80');
+    $host = (isset($parts['host'])) ? $parts['host'] : '';
+    $path = (isset($parts['path'])) ? $parts['path'] : '';
 
     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() {/*{{{*/
-    $out = $this->get_normalized_http_url() . "?";
-    $out .= $this->to_postdata();
+  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
-   *
-   * TODO(morten.fangel):
-   * this function might be easily replaced with http_build_query()
-   * and corrections for rfc3986 compatibility.. but not sure
    */
-  public function to_postdata() {/*{{{*/
-    $total = array();
-    foreach ($this->parameters as $k => $v) {
-      if (is_array($v)) {
-        foreach ($v as $va) {
-          $total[] = OAuthUtil::urlencode_rfc3986($k) . "[]=" . OAuthUtil::urlencode_rfc3986($va);
-        }
-      } else {
-        $total[] = OAuthUtil::urlencode_rfc3986($k) . "=" . OAuthUtil::urlencode_rfc3986($v);
-      }
-    }
-    $out = implode("&", $total);
-    return $out;
-  }/*}}}*/
+  public function to_postdata() {
+    return OAuthUtil::build_http_query($this->parameters);
+  }
 
   /**
    * builds the Authorization: header
    */
-  public function to_header() {/*{{{*/
-    $out ='Authorization: OAuth realm=""';
+  public function to_header($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');
-      $out .= ',' . OAuthUtil::urlencode_rfc3986($k) . '="' . OAuthUtil::urlencode_rfc3986($v) . '"';
+      if (is_array($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() {/*{{{*/
+  public function __toString() {
     return $this->to_url();
-  }/*}}}*/
+  }
 
 
-  public function sign_request($signature_method, $consumer, $token) {/*{{{*/
-    $this->set_parameter("oauth_signature_method", $signature_method->get_name());
+  public function sign_request($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);
-  }/*}}}*/
+    $this->set_parameter("oauth_signature", $signature, false);
+  }
 
-  public function build_signature($signature_method, $consumer, $token) {/*{{{*/
+  public function build_signature($signature_method, $consumer, $token) {
     $signature = $signature_method->build_signature($this, $consumer, $token);
     return $signature;
-  }/*}}}*/
+  }
 
   /**
    * util function: current timestamp
    */
-  private static function generate_timestamp() {/*{{{*/
+  private static function generate_timestamp() {
     return time();
-  }/*}}}*/
+  }
 
   /**
    * util function: current nonce
    */
-  private static function generate_nonce() {/*{{{*/
+  private static function generate_nonce() {
     $mt = microtime();
     $rand = mt_rand();
 
     return md5($mt . $rand); // md5s look nicer than numbers
-  }/*}}}*/
-
-  /**
-   * util function for turning the Authorization: header into
-   * parameters, has to do some unescaping
-   */
-  private static function split_header($header) {/*{{{*/
-    $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];
-      $params[$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
-   */
-  private 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
-      return apache_request_headers();
-    }
-    // otherwise we don't have apache and are just going to have to hope
-    // that $_SERVER actually contains what we need
-    $out = array();
-    foreach ($_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;
-  }/*}}}*/
-}/*}}}*/
+  }
+}
 
-class OAuthServer {/*{{{*/
+class OAuthServer {
   protected $timestamp_threshold = 300; // in seconds, five minutes
-  protected $version = 1.0;             // hi blaine
+  protected $version = '1.0';             // hi blaine
   protected $signature_methods = array();
 
   protected $data_store;
 
-  function __construct($data_store) {/*{{{*/
+  function __construct($data_store) {
     $this->data_store = $data_store;
-  }/*}}}*/
+  }
+
+  public function add_signature_method($signature_method) {
+    $this->signature_methods[$signature_method->get_name()] =
+      $signature_method;
+  }
 
-  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(&$request) {/*{{{*/
+  public function fetch_request_token(&$request) {
     $this->get_version($request);
 
     $consumer = $this->get_consumer($request);
@@ -517,16 +509,18 @@ class OAuthServer {/*{{{*/
 
     $this->check_signature($request, $consumer, $token);
 
-    $new_token = $this->data_store->new_request_token($consumer);
+    // 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(&$request) {/*{{{*/
+  public function fetch_access_token(&$request) {
     $this->get_version($request);
 
     $consumer = $this->get_consumer($request);
@@ -534,63 +528,76 @@ class OAuthServer {/*{{{*/
     // requires authorized request token
     $token = $this->get_token($request, $consumer, "request");
 
-
     $this->check_signature($request, $consumer, $token);
 
-    $new_token = $this->data_store->new_access_token($token, $consumer);
+    // 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(&$request) {/*{{{*/
+  public function verify_request(&$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(&$request) {/*{{{*/
+  private function get_version(&$request) {
     $version = $request->get_parameter("oauth_version");
     if (!$version) {
-      $version = 1.0;
+      // 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 && $version != $this->version) {
+    if ($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");
+  private function get_signature_method($request) {
+    $signature_method = $request instanceof OAuthRequest 
+        ? $request->get_parameter("oauth_signature_method")
+        : NULL;
+
     if (!$signature_method) {
-      $signature_method = "PLAINTEXT";
+      // According to chapter 7 ("Accessing Protected Ressources") the signature-method
+      // parameter is required, and we can't just fallback to PLAINTEXT
+      throw new OAuthException('No signature method parameter. This parameter is required');
     }
-    if (!in_array($signature_method, 
+
+    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))
-      );      
+        "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");
+  private function get_consumer($request) {
+    $consumer_key = $request instanceof OAuthRequest 
+        ? $request->get_parameter("oauth_consumer_key")
+        : NULL;
+
     if (!$consumer_key) {
       throw new OAuthException("Invalid consumer key");
     }
@@ -601,13 +608,16 @@ class OAuthServer {/*{{{*/
     }
 
     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');
+  private function get_token($request, $consumer, $token_type="access") {
+    $token_field = $request instanceof OAuthRequest
+         ? $request->get_parameter('oauth_token')
+         : NULL;
+
     $token = $this->data_store->lookup_token(
       $consumer, $token_type, $token_field
     );
@@ -615,175 +625,255 @@ class OAuthServer {/*{{{*/
       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, $token) {/*{{{*/
+  private function check_signature($request, $consumer, $token) {
     // this should probably be in a different method
-    $timestamp = @$request->get_parameter('oauth_timestamp');
-    $nonce = @$request->get_parameter('oauth_nonce');
+    $timestamp = $request instanceof OAuthRequest
+        ? $request->get_parameter('oauth_timestamp')
+        : NULL;
+    $nonce = $request instanceof OAuthRequest
+        ? $request->get_parameter('oauth_nonce')
+        : NULL;
 
     $this->check_timestamp($timestamp);
     $this->check_nonce($consumer, $token, $nonce, $timestamp);
 
     $signature_method = $this->get_signature_method($request);
 
-    $signature = $request->get_parameter('oauth_signature');    
+    $signature = $request->get_parameter('oauth_signature');
     $valid_sig = $signature_method->check_signature(
-      $request, 
-      $consumer, 
-      $token, 
+      $request,
+      $consumer,
+      $token,
       $signature
     );
 
     if (!$valid_sig) {
       throw new OAuthException("Invalid signature");
     }
-  }/*}}}*/
+  }
 
   /**
    * check that the timestamp is new enough
    */
-  private function check_timestamp($timestamp) {/*{{{*/
+  private function check_timestamp($timestamp) {
+    if( ! $timestamp )
+      throw new OAuthException(
+        'Missing timestamp parameter. The parameter is required'
+      );
+    
     // verify that timestamp is recentish
     $now = time();
-    if ($now - $timestamp > $this->timestamp_threshold) {
-      throw new OAuthException("Expired timestamp, yours $timestamp, ours $now");
+    if (abs($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, $timestamp) {/*{{{*/
+  private function check_nonce($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);
+    $found = $this->data_store->lookup_nonce(
+      $consumer,
+      $token,
+      $nonce,
+      $timestamp
+    );
     if ($found) {
       throw new OAuthException("Nonce already used: $nonce");
     }
-  }/*}}}*/
-
-
+  }
 
-}/*}}}*/
+}
 
-class OAuthDataStore {/*{{{*/
-  function lookup_consumer($consumer_key) {/*{{{*/
+class OAuthDataStore {
+  function lookup_consumer($consumer_key) {
     // implement me
-  }/*}}}*/
+  }
 
-  function lookup_token($consumer, $token_type, $token) {/*{{{*/
+  function lookup_token($consumer, $token_type, $token) {
     // implement me
-  }/*}}}*/
+  }
 
-  function lookup_nonce($consumer, $token, $nonce, $timestamp) {/*{{{*/
+  function lookup_nonce($consumer, $token, $nonce, $timestamp) {
     // implement me
-  }/*}}}*/
+  }
 
-  function new_request_token($consumer) {/*{{{*/
+  function new_request_token($consumer, $callback = null) {
     // return a new token attached to this consumer
-  }/*}}}*/
+  }
 
-  function new_access_token($token, $consumer) {/*{{{*/
+  function new_access_token($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
-  }/*}}}*/
-
-}/*}}}*/
-
-
-/*  A very naive dbm-based oauth storage
- */
-class SimpleOAuthDataStore extends OAuthDataStore {/*{{{*/
-  private $dbh;
+  }
 
-  function __construct($path = "oauth.gdbm") {/*{{{*/
-    $this->dbh = dba_popen($path, 'c', 'gdbm');
-  }/*}}}*/
+}
+
+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 '';
+  }
+}
 
-  function __destruct() {/*{{{*/
-    dba_close($this->dbh);
-  }/*}}}*/
 
-  function lookup_consumer($consumer_key) {/*{{{*/
-    $rv = dba_fetch("consumer_$consumer_key", $this->dbh);
-    if ($rv === FALSE) {
-      return NULL;
-    }
-    $obj = unserialize($rv);
-    if (!($obj instanceof OAuthConsumer)) {
-      return NULL;
-    }
-    return $obj;
-  }/*}}}*/
+  // This decode function isn't taking into consideration the above
+  // modifications to the encoding process. However, this method doesn't
+  // seem to be used anywhere so leaving it as is.
+  public static function urldecode_rfc3986($string) {
+    return urldecode($string);
+  }
 
-  function lookup_token($consumer, $token_type, $token) {/*{{{*/
-    $rv = dba_fetch("${token_type}_${token}", $this->dbh);
-    if ($rv === FALSE) {
-      return NULL;
-    }
-    $obj = unserialize($rv);
-    if (!($obj instanceof OAuthToken)) {
-      return NULL;
+  // Utility function for turning the Authorization: header into
+  // parameters, has to do some unescaping
+  // Can filter out any non-oauth parameters if needed (default behaviour)
+  // May 28th, 2010 - method updated to tjerk.meesters for a speed improvement.
+  //                  see http://code.google.com/p/oauth/issues/detail?id=163
+  public static function split_header($header, $only_allow_oauth_parameters = true) {
+    $params = array();
+    if (preg_match_all('/('.($only_allow_oauth_parameters ? 'oauth_' : '').'[a-z_-]*)=(:?"([^"]*)"|([^,]*))/', $header, $matches)) {
+      foreach ($matches[1] as $i => $h) {
+        $params[$h] = OAuthUtil::urldecode_rfc3986(empty($matches[3][$i]) ? $matches[4][$i] : $matches[3][$i]);
+      }
+      if (isset($params['realm'])) {
+        unset($params['realm']);
+      }
     }
-    return $obj;
-  }/*}}}*/
+    return $params;
+  }
 
-  function lookup_nonce($consumer, $token, $nonce, $timestamp) {/*{{{*/
-    if (dba_exists("nonce_$nonce", $this->dbh)) {
-      return TRUE;
+  // 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] = $value;
+      }
     } else {
-      dba_insert("nonce_$nonce", "1", $this->dbh);
-      return FALSE;
+      // 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] = $value;
+        }
+      }
     }
-  }/*}}}*/
-
-  function new_token($consumer, $type="request") {/*{{{*/
-    $key = md5(time());
-    $secret = time() + time();
-    $token = new OAuthToken($key, md5(md5($secret)));
-    if (!dba_insert("${type}_$key", serialize($token), $this->dbh)) {
-      throw new OAuthException("doooom!");
+    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 $token;
-  }/*}}}*/
+    return $parsed_parameters;
+  }
 
-  function new_request_token($consumer) {/*{{{*/
-    return $this->new_token($consumer, "request");
-  }/*}}}*/
+  public static function build_http_query($params) {
+    if (!$params) return '';
 
-  function new_access_token($token, $consumer) {/*{{{*/
+    // Urlencode both keys and values
+    $keys = OAuthUtil::urlencode_rfc3986(array_keys($params));
+    $values = OAuthUtil::urlencode_rfc3986(array_values($params));
+    $params = array_combine($keys, $values);
 
-    $token = $this->new_token($consumer, 'access');
-    dba_delete("request_" . $token->key, $this->dbh);
-    return $token;
-  }/*}}}*/
-}/*}}}*/
-
-class OAuthUtil {/*{{{*/
-  public static function urlencode_rfc3986($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($input)));
-	} else {
-		return '';
-	}
-  }/*}}}*/
-    
+    // Parameters are sorted by name, using lexicographical byte value ordering.
+    // Ref: Spec: 9.1.1 (1)
+    uksort($params, 'strcmp');
 
-  // 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($string) {/*{{{*/
-    return rawurldecode($string);
-  }/*}}}*/
-}/*}}}*/
+    $pairs = array();
+    foreach ($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)
+        // June 12th, 2010 - changed to sort because of issue 164 by hidetaka
+        sort($value, SORT_STRING);
+        foreach ($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);
+  }
+}
 
 ?>