tao-test/app/taoLtiBasicOutcome/includes/ims-blti/OAuth.php

894 lines
26 KiB
PHP

<?php
// vim: foldmethod=marker
$OAuth_last_computed_signature = false;
if (!class_exists('OAuthException')) {
/* 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 == $signature;
}
}
class OAuthSignatureMethod_HMAC_SHA1 extends OAuthSignatureMethod
{
function get_name()
{
return "HMAC-SHA1";
}
public function build_signature($request, $consumer, $token)
{
global $OAuth_last_computed_signature;
$OAuth_last_computed_signature = false;
$base_string = $request->get_signature_base_string();
$request->base_string = $base_string;
$key_parts = [
$consumer->secret,
($token) ? $token->secret : ""
];
$key_parts = OAuthUtil::urlencode_rfc3986($key_parts);
$key = implode('&', $key_parts);
$computed_signature = base64_encode(hash_hmac('sha1', $base_string, $key, true));
$OAuth_last_computed_signature = $computed_signature;
return $computed_signature;
}
}
class OAuthSignatureMethod_PLAINTEXT extends OAuthSignatureMethod
{
public function get_name()
{
return "PLAINTEXT";
}
public function build_signature($request, $consumer, $token)
{
$sig = [
OAuthUtil::urlencode_rfc3986($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';
public static $POST_INPUT = 'php://input';
function __construct($http_method, $http_url, $parameters = null)
{
@$parameters or $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';
$port = "";
if (
$_SERVER['SERVER_PORT'] != "80" && $_SERVER['SERVER_PORT'] != "443" &&
strpos(':', $_SERVER['HTTP_HOST']) < 0
) {
$port = ':' . $_SERVER['SERVER_PORT'] ;
}
@$http_url or $http_url = $scheme .
'://' . $_SERVER['HTTP_HOST'] .
$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']);
$ourpost = $_POST;
// Deal with magic_quotes
// http://www.php.net/manual/en/security.magicquotes.disabling.php
if (get_magic_quotes_gpc()) {
$outpost = [];
foreach ($_POST as $k => $v) {
$v = stripslashes($v);
$ourpost[$k] = $v;
}
}
// Add POST Parameters if they exist
$parameters = array_merge($parameters, $ourpost);
// We have a Authorization-header with OAuth data. Parse the header
// and add those overriding any duplicates from GET or POST
if (@substr($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 = [];
$defaults = ["oauth_version" => OAuthRequest::$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);
// Parse the query-string to find and add GET parameters
$parts = parse_url($http_url);
if (isset($parts['query'])) {
$qparms = OAuthUtil::parse_parameters($parts['query']);
$parameters = array_merge($qparms, $parameters);
}
return new OAuthRequest($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] = [$this->parameters[$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 = [
$this->get_normalized_http_method(),
$this->get_normalized_http_url(),
$this->get_signable_parameters()
];
$parts = OAuthUtil::urlencode_rfc3986($parts);
return implode('&', $parts);
}
/**
* just uppercases the http method
*/
public function get_normalized_http_method()
{
return strtoupper($this->http_method);
}
/**
* parses the url and rebuilds it to be
* scheme://host/path
*/
public function get_normalized_http_url()
{
$parts = parse_url($this->http_url);
$port = @$parts['port'];
$scheme = $parts['scheme'];
$host = $parts['host'];
$path = @$parts['path'];
$port or $port = ($scheme == 'https') ? '443' : '80';
if (
($scheme == 'https' && $port != '443')
|| ($scheme == 'http' && $port != '80')
) {
$host = "$host:$port";
}
return "$scheme://$host$path";
}
/**
* builds a url usable for a GET request
*/
public function to_url()
{
$post_data = $this->to_postdata();
$out = $this->get_normalized_http_url();
if ($post_data) {
$out .= '?' . $post_data;
}
return $out;
}
/**
* builds the data one would send in a POST request
*/
public function to_postdata()
{
return OAuthUtil::build_http_query($this->parameters);
}
/**
* builds the Authorization: header
*/
public function to_header()
{
$out = 'Authorization: OAuth realm=""';
$total = [];
foreach ($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(),
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 = [];
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)
{
global $OAuth_last_computed_signature;
$OAuth_last_computed_signature = false;
$this->get_version($request);
$consumer = $this->get_consumer($request);
$token = $this->get_token($request, $consumer, "access");
$this->check_signature($request, $consumer, $token);
return [$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');
if (!$token_field) {
return false;
}
$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
global $OAuth_last_computed_signature;
$OAuth_last_computed_signature = false;
$timestamp = @$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) {
$ex_text = "Invalid signature";
if ($OAuth_last_computed_signature) {
$ex_text = $ex_text . " ours= $OAuth_last_computed_signature yours=$signature";
}
throw new OAuthException($ex_text);
}
}
/**
* check that the timestamp is new enough
*/
private function check_timestamp($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, $consumer)
{
// return a new access token attached to this consumer
// for the user associated with this token if the request token
// is authorized
// should also invalidate the request token
}
}
class OAuthUtil
{
public static function urlencode_rfc3986($input)
{
if (is_array($input)) {
return array_map(['OAuthUtil', 'urlencode_rfc3986'], $input);
} elseif (is_scalar($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;
$params = [];
while (preg_match($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
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
$out = [];
foreach ($_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 [];
}
$pairs = split('&', $input);
$parsed_parameters = [];
foreach ($pairs as $pair) {
$split = split('=', $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] = [$parsed_parameters[$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');
$pairs = [];
foreach ($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);
}
}