gnu-social/extlib/OAuth.php

790 lines
23 KiB
PHP

<?php
// vim: foldmethod=marker
/* Generic exception class
*/
class OAuthException extends Exception {/*{{{*/
// pass
}/*}}}*/
class OAuthConsumer {/*{{{*/
public $key;
public $secret;
function __construct($key, $secret, $callback_url=NULL) {/*{{{*/
$this->key = $key;
$this->secret = $secret;
$this->callback_url = $callback_url;
}/*}}}*/
function __toString() {/*{{{*/
return "OAuthConsumer[key=$this->key,secret=$this->secret]";
}/*}}}*/
}/*}}}*/
class OAuthToken {/*{{{*/
// access tokens and request tokens
public $key;
public $secret;
/**
* key = the token
* secret = the token secret
*/
function __construct($key, $secret) {/*{{{*/
$this->key = $key;
$this->secret = $secret;
}/*}}}*/
/**
* generates the basic string serialization of a token that a server
* would respond to request_token and access_token calls with
*/
function to_string() {/*{{{*/
return "oauth_token=" . OAuthUtil::urlencode_rfc3986($this->key) .
"&oauth_token_secret=" . OAuthUtil::urlencode_rfc3986($this->secret);
}/*}}}*/
function __toString() {/*{{{*/
return $this->to_string();
}/*}}}*/
}/*}}}*/
class OAuthSignatureMethod {/*{{{*/
public function check_signature(&$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;
}
$result = 0;
// Avoid a timing leak with a (hopefully) time insensitive compare
for ($i = 0; $i < strlen($signature); $i++) {
$result |= ord($built{$i}) ^ ord($signature{$i});
}
return $result == 0;
}
}/*}}}*/
class OAuthSignatureMethod_HMAC_SHA1 extends OAuthSignatureMethod {/*{{{*/
function get_name() {/*{{{*/
return "HMAC-SHA1";
}/*}}}*/
public function build_signature($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, $key, true));
}/*}}}*/
}/*}}}*/
class OAuthSignatureMethod_PLAINTEXT extends OAuthSignatureMethod {/*{{{*/
public function get_name() {/*{{{*/
return "PLAINTEXT";
}/*}}}*/
public function build_signature($request, $consumer, $token) {/*{{{*/
$sig = array(
OAuthUtil::urlencode_rfc3986($consumer->secret)
);
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);
}/*}}}*/
}/*}}}*/
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) {/*{{{*/
$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 $version = '1.0';
function __construct($http_method, $http_url, $parameters=NULL) {/*{{{*/
@$parameters or $parameters = array();
$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'];
$request_headers = OAuthRequest::get_headers();
// let the library user override things however they'd like, if they know
// which parameters to use then go for it, for example XMLRPC might want to
// do this
if ($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, $_POST);
}
// next check for the auth header, we need to do some extra stuff
// if that is the case, namely suck in the parameters from GET or POST
// so that we can include them in the signature
if (@substr($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 $req;
}/*}}}*/
/**
* pretty much a helper function to set up the request
*/
public static function from_consumer_and_token($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);
$parameters = array_merge($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] = $value;
}/*}}}*/
public function get_parameter($name) {/*{{{*/
return isset($this->parameters[$name]) ? $this->parameters[$name] : null;
}/*}}}*/
public function get_parameters() {/*{{{*/
return $this->parameters;
}/*}}}*/
/**
* 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 &.
*
* @return string
*/
public function get_signable_parameters() {/*{{{*/
// Grab all parameters
$params = $this->parameters;
// Remove oauth_signature if present
if (isset($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);
}/*}}}*/
/**
* 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);
$port = isset($parts['port']) ? $parts['port'] : null;
$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() {/*{{{*/
$out = $this->get_normalized_http_url() . "?";
$out .= $this->to_postdata();
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;
}/*}}}*/
/**
* builds the Authorization: header
*/
public function to_header() {/*{{{*/
$out ='Authorization: OAuth realm=""';
$total = array();
foreach ($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) . '"';
}
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());
$signature = $this->build_signature($signature_method, $consumer, $token);
$this->set_parameter("oauth_signature", $signature);
}/*}}}*/
public function build_signature($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 . $rand); // md5s look nicer than numbers
}/*}}}*/
/**
* util function for turning the Authorization: header into
* parameters, has to do some unescaping
*/
private static function split_header($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 {/*{{{*/
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);
$new_token = $this->data_store->new_request_token($consumer);
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);
$new_token = $this->data_store->new_access_token($token, $consumer);
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) {
$version = 1.0;
}
if ($version && $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) {
$signature_method = "PLAINTEXT";
}
if (!in_array($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) {/*{{{*/
// verify that timestamp is recentish
$now = time();
if ($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) {/*{{{*/
// 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) {/*{{{*/
// return a new token attached to this consumer
}/*}}}*/
function new_access_token($token, $consumer) {/*{{{*/
// 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');
}/*}}}*/
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 $obj;
}/*}}}*/
function lookup_token($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;
}
return $obj;
}/*}}}*/
function lookup_nonce($consumer, $token, $nonce, $timestamp) {/*{{{*/
if (dba_exists("nonce_$nonce", $this->dbh)) {
return TRUE;
} else {
dba_insert("nonce_$nonce", "1", $this->dbh);
return FALSE;
}
}/*}}}*/
function new_token($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 $token;
}/*}}}*/
function new_request_token($consumer) {/*{{{*/
return $this->new_token($consumer, "request");
}/*}}}*/
function new_access_token($token, $consumer) {/*{{{*/
$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($input)));
} else {
return '';
}
}/*}}}*/
// This decode function isn't taking into consideration the above
// modifications to the encoding process. However, this method doesn't
// seem to be used anywhere so leaving it as is.
public static function urldecode_rfc3986($string) {/*{{{*/
return rawurldecode($string);
}/*}}}*/
}/*}}}*/
?>