OAuthRequest.php

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<?php

namespace ceLTIc\LTI\OAuth;

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)
    {
        $parameters = ($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;
    }

    public static function from_request($http_method = null, $http_url = null, $parameters = null)
    {
        if (!$http_url) {
            if (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && ($_SERVER['HTTP_X_FORWARDED_PROTO'] === 'https')) {
                $_SERVER['HTTPS'] = 'on';
                if (isset($_SERVER['HTTP_X_FORWARDED_HOST'])) {
                    $_SERVER['HTTP_HOST'] = $_SERVER['HTTP_X_FORWARDED_HOST'];
                }
                if ($_SERVER['SERVER_PORT'] == 80) {
                    $_SERVER['SERVER_PORT'] = 443;
                }
            }
            $scheme = (!isset($_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
            if (isset($_SERVER['QUERY_STRING'])) {
                $parameters = OAuthUtil::parse_parameters($_SERVER['QUERY_STRING']);
            } else {
                $parameters = array();
            }

            if (($http_method == "POST" && isset($request_headers['Content-Type']) && stristr($request_headers['Content-Type'],
                    'application/x-www-form-urlencoded')) || !empty($_POST)) {
                // It's a POST request of the proper content-type, so parse POST
                // parameters and add those overriding any duplicates from GET
                $post_data = OAuthUtil::parse_parameters(file_get_contents(self::$POST_INPUT));
                $parameters = array_merge_recursive($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 (isset($request_headers['Authorization']) && substr($request_headers['Authorization'], 0, 6) == 'OAuth ') {
                $header_parameters = OAuthUtil::split_header($request_headers['Authorization']);
                $parameters = array_merge_recursive($parameters, $header_parameters);
            }
        }

        return new OAuthRequest($http_method, $http_url, $parameters);
    }

    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);

        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]);
    }

    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);
    }

    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);
    }

    public function get_normalized_http_method()
    {
        return strtoupper($this->http_method);
    }

    public function get_normalized_http_url()
    {
        $parts = parse_url($this->http_url);

        $scheme = (isset($parts['scheme'])) ? $parts['scheme'] : 'http';
        $port = (isset($parts['port'])) ? $parts['port'] : (($scheme == 'https') ? '443' : '80');
        $host = (isset($parts['host'])) ? strtolower($parts['host']) : '';
        $path = (isset($parts['path'])) ? $parts['path'] : '';

        if (($scheme == 'https' && $port != '443') || ($scheme == 'http' && $port != '80')) {
            $host = "$host:$port";
        }

        return "$scheme://$host$path";
    }

    public function to_url()
    {
        $post_data = $this->to_postdata();
        $out = $this->get_normalized_http_url();
        if ($post_data) {
            $out .= '?' . $post_data;
        }

        return $out;
    }

    public function to_postdata()
    {
        return OAuthUtil::build_http_query($this->parameters);
    }

    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;
    }

    private static function generate_timestamp()
    {
        return time();
    }

    private static function generate_nonce()
    {
        $mt = microtime();
        $rand = mt_rand();

        return md5($mt . $rand); // md5s look nicer than numbers
    }

}