gPass/firefox_webextension/background.js

/*
  Copyright (C) 2013-2020 Grégory Soutadé

  This file is part of gPass.

  gPass is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  gPass is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with gPass.  If not, see <http://www.gnu.org/licenses/>.
*/

var browser = browser || chrome;
var protocol_version = 4;
var account_url = null;
var crypto_v2_logins_size = 0;

function _notification(message, data)
{
    if (message !== data)
	message += data;

    options = {
	type: "basic",
	title : "gPass",
	message : message,
	iconUrl:browser.extension.getURL("icons/gpass_icon_64.png")
    };

    browser.notifications.create("gPass", options, function(){});

    window.setTimeout(function() {browser.notifications.clear("gPass", function(){})}, 2000);
}

async function generate_request(domain, login, mkey, iv, old)
{
    if (old)
    {
	var v = "@@" + domain + ";" + login;
	debug("will encrypt " + v);
	enc = encrypt_ecb(mkey, v);
    }
    else
    {
	var v = domain + ";" + login;
	debug("will encrypt " + v);
	while ((v.length % 16))
	    v += "\0";
	hash = await digest(v);
	v += hash.slice(8, 24);
	enc = encrypt_cbc(mkey, iv, v);
    }
    return enc;
}

async function ask_server(logins, domain, wdomain, mkey, sendResponse, options)
{
    account_url = await get_preference("account_url");

    var salt = parseURI.parseUri(account_url);
    salt = salt["host"] + salt["path"];

    debug("salt " + salt);

    pbkdf2_level = await get_preference("pbkdf2_level");

    global_iv = await simple_pbkdf2(salt, mkey, pbkdf2_level);
    global_iv = global_iv.slice(0, 16);
    mkey = crypto_pbkdf2(mkey, salt, pbkdf2_level);

    debug("global_iv " + a2hex(global_iv));

    keys = "";
    for(key_index=0, a=0; a<logins.length; a++, key_index++)
    {
	enc = await generate_request(domain, logins[a], mkey, global_iv, 0);
	keys += (keys.length != 0) ? "&" : "";
	keys += "k" + key_index + "=" + a2hex(enc);

	if (wdomain != "")
	{
	    enc = await generate_request(wdomain, logins[a], mkey, global_iv, 0);
	    keys += (keys.length != 0) ? "&" : "";
	    keys += "k" + (++key_index) + "=" + a2hex(enc);
	}
    }

    crypto_v2_logins_size = key_index;
    if (await get_preference("crypto_v1_compatible"))
    {
	for(a=0; a<logins.length; a++, key_index++)
	{
	    enc = await generate_request(domain, logins[a], mkey, global_iv, 1);
	    keys += (keys.length != 0) ? "&" : "";
	    keys += "k" + key_index + "=" + a2hex(enc);

	    if (wdomain != "")
	    {
		enc = await generate_request(wdomain, logins[a], mkey, global_iv, 1);
		keys += (keys.length != 0) ? "&" : "";
		keys += "k" + (++key_index) + "=" + a2hex(enc);
	    }
	}
    }
    debug("Keys " + keys);

    var gPassRequest = new XMLHttpRequest();

    var ret = SERVER.OK;

    // gPassRequest.addEventListener("progress", function(evt) { ; }, false);
    gPassRequest.addEventListener("load", async function(evt) {
	var ciphered_password = "";
	var clear_password = "";
	var server_pbkdf2_level = 0;
	var server_version = 0;
	var matched_key = 0;

	var r = this.responseText.split("\n");
	debug("resp " + r);

	for(var a=0; a<r.length; a++)
	{
	    debug("Analyse " + r[a]);

	    params = r[a].split("=");
	    if (params.length != 2 && params[0] != "<end>")
	    {
		_notification("Error : It seems that it's not a gPass server",
			      this.responseText);
		ret = SERVER.FAILED;
		break;
	    }

	    switch(params[0])
	    {
		case "protocol":
		debug("protocol : " + params[1]);

		if (params[1].indexOf("gpass-") != 0)
		{
		    _notification("Error : It seems that it's not a gPass server",
				  this.responseText);
		    ret = SERVER.FAILED;
		    break;
		}

		server_protocol_version = params[1].match(/\d+/)[0];

		if (server_protocol_version > protocol_version)
		{
		    _notification("Protocol version not supported, please upgrade your addon", "");
		    ret = SERVER.FAILED;
		}
		else
		{
		    switch (server_protocol_version)
		    {
			case 2:
			server_pbkdf2_level = 1000;
			break;
			case 3:
			// Version 3 : nothing special to do
			case 4:
			// Version 4 : nothing special to do
			break;
		    }
		}
		break;
		case "matched_key":
		matched_key = params[1];
		case "pass":
		ciphered_password = params[1];
		break;
		case "pkdbf2_level":
		case "pbkdf2_level":
		server_pbkdf2_level = parseInt(params[1].match(/\d+/)[0], 10);
		if (server_pbkdf2_level != NaN &&
		    server_pbkdf2_level != pbkdf2_level &&
		    server_pbkdf2_level >= 1000) // Minimum level for PBKDF2 !
		    {
			debug("New pbkdf2 level " + server_pbkdf2_level);
			pbkdf2_level = server_pbkdf2_level;
			set_preference("pbkdf2_level", pbkdf2_level);
			ret = SERVER.RESTART_REQUEST;
		    }
		break;
		case "<end>":
		break;
		default:
		debug("Unknown command " + params[0]);

		_notification("Error : It seems that it's not a gPass server",
			      this.responseText);
		ret = SERVER.FAILED;
		break;
	    }
	}

	if (ret != SERVER.OK)
	{
	    sendResponse({"value": ret, options:options});
	    return;
	}

	if (ciphered_password != "")
	{
	    debug("Ciphered password : " + ciphered_password);
	    if (matched_key >= crypto_v2_logins_size)
		// Crypto v1
	    {
		clear_password = await decrypt_ecb(mkey, hex2a(ciphered_password));
		// Remove trailing \0 and salt
		clear_password = clear_password.replace(/\0*$/, "");
		clear_password = clear_password.substr(0, clear_password.length-3);
	    }
	    else
	    {
		clear_password = await decrypt_cbc(mkey, global_iv, hex2a(ciphered_password));
		clear_password = clear_password.replace(/\0*$/, "");
		clear_password = clear_password.substr(3, clear_password.length);
	    }
	    debug("Clear password " + clear_password);
	}
	else
	{
	    debug("No password found");

	    ret = SERVER.FAILED;

	    _notification("No password found in database", "")
	}

	sendResponse({"value": ret, "password":clear_password, "options":options});
    }, false);
    gPassRequest.addEventListener("error", function(evt) {
	debug("error");
	ret = false;
	_notification("Error");
    }, false);
    debug("connect to " + account_url);
    gPassRequest.open("POST", account_url, true);
    gPassRequest.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8');
    gPassRequest.send(keys);

    return true;
}

function url_block_callback(details)
{
    // debug(JSON.stringify(details));
    if (details.requestBody)
    {
	if (details.requestBody.formData)
	{
	    for (var key in details.requestBody.formData)
	    {
		for(var idx in details.requestBody.formData[key])
		{
		    value = details.requestBody.formData[key][idx];
		    if (value.startsWith("@@") ||
			value.startsWith("@_"))
			return {cancel: true};
		}
	    }
	}

	/*
	// Analyse POST parameters
	if (details.method == "POST" && details.requestBody.raw)
	{
	alert(details.requestBody.raw);
	var postedString = decodeURIComponent(String.fromCharCode.apply(null,
        new Uint8Array(details.requestBody.raw[0].bytes)));
	if (postedString.indexOf("=@@") != -1 ||
	postedString.indexOf("=@_") != -1)
	return {cancel: true};
	}
	*/
    }

    return {cancel: false};
}

function url_unblock_callback(details)
{
    return {cancel: false};
}

function update_gpass_icon(iconId, tabId)
{
    debug("update_gpass_icon");

    icon_infos = {"tabId":tabId};
    icon_name = "";
    
    switch (iconId)
    {
	case GPASS_ICON.NORMAL: break;
	case GPASS_ICON.DISABLED:
	icon_name = "_disabled";
	break;
	case GPASS_ICON.ACTIVATED:
	icon_name = "_activated";
	break;
	default:
    }
    
    icon_infos["path"] = {
	16:"icons/gpass" + icon_name + "_icon_16.png",
	32:"icons/gpass" + icon_name + "_icon_32.png",
	64:"icons/gpass" + icon_name + "_icon_64.png",
	128:"icons/gpass" + icon_name + "_icon_128.png",
    };

    browser.browserAction.setIcon(icon_infos);
}

function is_gpass_enabled(uri)
{
    var domain = parseURI.parseUri(uri);
    domain = domain["host"];
    debug("Is gpass enabled for " + domain + " ?");
    return get_preference("disable-" + domain);
}

function save_gpass_enable_config(uri, enable)
{
    var domain = parseURI.parseUri(uri);
    domain = domain["host"];

    key = "disable-" + domain;
    if (enable)
    {
	debug("Enable gpass for " + domain);
	delete_preference(key);
    }
    else
    {
	debug("Disable gpass for " + domain);
	set_preference(key, true);
    }
}

function _block_url(tabs, callback)
{
    options = {
	urls:[tabs[0].url],
	"types":["main_frame"]
    };

    if (tabs.length)
    {
	options["tabId"] = tabs[0].id;
	options["windowId"] = tabs[0].windowId;
    }

    browser.webRequest.onBeforeRequest.addListener(
	url_block_callback,
	options,
	["blocking", "requestBody"]);

    return true;

}

function _query_tabs_block_url(tabs)
{
    return _block_url(tabs, url_block_callback);
}

function _query_tabs_unblock_url(tabs)
{
    return _block_url(tabs, url_unblock_callback);
}

function _query_tabs_is_gpass_enabled(tabs, sendResponse)
{
    if (tabs.length)
    {
	is_gpass_enabled(tabs[0].url).then(
	    function (key_present) {
		enabled = (key_present == null);
		update_gpass_icon((enabled)?GPASS_ICON.ENABLED:GPASS_ICON.DISABLED, tabs[0].id);
		sendResponse({"enabled":enabled});
	    }
	);
    }
    else
    {
	debug("No cur tab");
	sendResponse({"enabled":true});
    }

    return true;
}

function _query_tabs_update_icon(tabs, iconId)
{
    if (tabs.length)
    {
	update_gpass_icon(iconId, tabs[0].id);
    }
}

function gpass_switch_enable(tab)
{
    is_gpass_enabled(tab.url).then(
	function (key_present)
	{
	    enabled = (key_present == null);
	    // Do switch
	    enabled = !enabled;
	    if (enabled)
	    {
		parameters = {type:"blockForms"};
		debug("Now enabled");
	    }
	    else
	    {
		parameters = {type:"unblockForms"};
		debug("Now disabled");
	    }

	    save_gpass_enable_config(tab.url, enabled);
	    update_gpass_icon((enabled)?GPASS_ICON.ENABLED:GPASS_ICON.DISABLED, tab.id);
	    browser.tabs.sendMessage(tab.id, parameters);
	});
}

function extension_load()
{
    browser.runtime.onMessage.addListener(
	function(request, sender, sendResponse) {
	    if (request.type == "password")
	    {
		var domain = parseURI.parseUri(request.domain);
		domain = domain["host"];
		var wdomain = wildcard_domain(domain);

		ask_server(request.logins, domain,
			   wdomain, request.mkey,
			   sendResponse, request.options);

    		return true;
	    }
	    else if (request.type == "notification")
	    {
		_notification(request.options.message, request.options.data);
	    }
	    else if (request.type == "getServerAddress")
	    {
		get_preference("account_url").then(
		    function (address) {
			sendResponse({"value" : address});
		    });
		return true;
	    }
	    else if (request.type == "block_url")
	    {
		browser.tabs.query({active:true, currentWindow:true}, _query_tabs_block_url);
	    }
	    else if (request.type == "unblock_url")
	    {
		browser.tabs.query({active:true, currentWindow:true}, _query_tabs_unblock_url);
	    }
	    else if (request.type == "is_gpass_enabled")
	    {
		browser.tabs.query({active:true, currentWindow:true},
				   function cb(tabs) {
				       _query_tabs_is_gpass_enabled(tabs, sendResponse);
				   });
		return true;
	    }
	    else if (request.type == "switch_enable")
	    {
		debug("Switch enable");
		browser.tabs.query({active:true, currentWindow:true},
				   function cb(tabs) {
				       _query_tabs_switch_enable(tabs, sendResponse)
				   });
		return true;
	    }
	    else if (request.type == "update_icon")
	    {
		debug("update_icon");
		browser.tabs.query({active:true, currentWindow:true},
				   function cb(tabs) {
				       _query_tabs_update_icon(tabs, request.icon_id);
				   });
	    }
	    else
	    {
		debug("Unknown message " + request.type);
	    }
	}
    );

    if (!browser.menus && browser.contextMenus)
	browser.menus = browser.contextMenus;
    
    browser.menus.create({
	id: 'settings',
	title: 'gPass Settings',
	contexts: ['browser_action']
    });

    /* Not supported by Chrome */
    if (browser.menus.onShown)
	title = 'disable gPass for this website';
    else
	title = 'disable or enable gPass for this website';
    
    browser.menus.create({
	id: 'switch_enable',
	title: title,
	contexts: ['browser_action']
    });

    browser.menus.onClicked.addListener(
	function(info, tab) {
	    switch (info.menuItemId) {
	    case 'settings':
		browser.runtime.openOptionsPage();
		break;

	    case 'switch_enable':
		gpass_switch_enable(tab);
		break;
	    }
	}
    );
    
    if (browser.menus.onShown)
    {
	browser.menus.onShown.addListener(
	    function(info, tab) {
		is_gpass_enabled(tab.url).then(
		    function (key_present) {
			enabled = (key_present == null);
			if (enabled)
			    title = 'disable gPass for this website';
			else
			    title = 'enable gPass for this website';
			browser.menus.update("switch_enable",
					     {
						 "title":title
					     }
					    );
			browser.menus.refresh();
		    }
		);
	    }
	);
    }
}

async function self_test()
{
    mkey = crypto_pbkdf2("password", "salt", 4096);
    res = await encrypt_ecb(mkey, "DDDDDDDDDDDDDDDD");

    reference = new Uint8Array([0xc4, 0x76, 0x01, 0x07, 0xa1, 0xc0, 0x2f, 0x22, 0xee, 0xbe, 0x60,
				0xff, 0x65, 0x33, 0x5b, 0x9e]);
    if (res != ab2str(reference))
    {
    	console.log("Self test ERROR !");
    }
    else
    	console.log("Self test OK !");
}

//self_test();

extension_load();