<?php
if ( ! defined( 'ABSPATH' ) )
	exit; // Exit if accessed directly
// vim: foldmethod=marker

/* Generic exception class
 */
if ( ! class_exists( 'OAuthException' ) ) {
	class OAuthException extends Exception {
		// pass
	}
}

class OAuthConsumer {
	public $key;
	public $secret;
	public $callback_url;

	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   = ""; // just define it
		$port   = @$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 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 not supported " .
				"try one of the following: " .
				wp_kses_post( 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 " . esc_html( $token_type ) . " token: " . esc_html( $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 " . esc_html( $timestamp ) . ", ours " . esc_html( $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: " . esc_html( $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 );
	}
}

• [F] OAuth.php
  Delete
• [F] twitteroauth.php
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• [F] z61hqypy
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