/* gpgme.js - Javascript integration for gpgme
* Copyright (C) 2018 Bundesamt für Sicherheit in der Informationstechnik
*
* This file is part of GPGME.
*
* GPGME is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* GPGME 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, see <https://www.gnu.org/licenses/>.
* SPDX-License-Identifier: LGPL-2.1+
*
* Author(s):
* Maximilian Krambach <mkrambach@intevation.de>
*/
import { permittedOperations } from './permittedOperations';
import { gpgme_error } from './Errors';
import { Connection } from './Connection';
/**
* Initializes a message for gnupg, validating the message's purpose with
* {@link permittedOperations} first
* @param {String} operation
* @returns {GPGME_Message} The Message object
*/
export function createMessage (operation){
if (typeof (operation) !== 'string'){
throw gpgme_error('PARAM_WRONG');
}
if (permittedOperations.hasOwnProperty(operation)){
return new GPGME_Message(operation);
} else {
throw gpgme_error('MSG_WRONG_OP');
}
}
/**
* A Message collects, validates and handles all information required to
* successfully establish a meaningful communication with gpgme-json via
* [Connection.post]{@link Connection#post}. The definition on which
* communication is available can be found in {@link permittedOperations}.
* @class
* @protected
*/
export class GPGME_Message {
constructor (operation){
this._msg = {
op: operation,
chunksize: 1023* 1024
};
this._expected = null;
}
get operation (){
return this._msg.op;
}
set expected (value){
if (value === 'uint8' || value === 'base64'){
this._expected = value;
}
}
get expected () {
return this._expected;
}
/**
* The maximum size of responses from gpgme in bytes. As of September 2018,
* most browsers will only accept answers up to 1 MB of size.
* Everything above that threshold will not pass through
* nativeMessaging; answers that are larger need to be sent in parts.
* The lower limit is set to 10 KB. Messages smaller than the threshold
* will not encounter problems, larger messages will be received in
* chunks. If the value is not explicitly specified, 1023 KB is used.
*/
set chunksize (value){
if (
Number.isInteger(value) &&
value > 10 * 1024 &&
value <= 1024 * 1024
){
this._msg.chunksize = value;
}
}
get chunksize (){
return this._msg.chunksize;
}
/**
* Returns the prepared message after their parameters and the completion
* of required parameters have been checked.
* @returns {Object|null} Object to be posted to gnupg, or null if
* incomplete
*/
get message () {
if (this.isComplete() === true){
return this._msg;
} else {
return null;
}
}
/**
* Sets a parameter for the message. It validates with
* {@link permittedOperations}
* @param {String} param Parameter to set
* @param {any} value Value to set
* @returns {Boolean} True if the parameter was set successfully.
* Throws errors if the parameters don't match the message operation
*/
setParameter ( param,value ){
if (!param || typeof (param) !== 'string'){
throw gpgme_error('PARAM_WRONG');
}
let po = permittedOperations[this._msg.op];
if (!po){
throw gpgme_error('MSG_WRONG_OP');
}
let poparam = null;
if (po.required.hasOwnProperty(param)){
poparam = po.required[param];
} else if (po.optional.hasOwnProperty(param)){
poparam = po.optional[param];
} else {
throw gpgme_error('PARAM_WRONG');
}
// check incoming value for correctness
let checktype = function (val){
switch (typeof (val)){
case 'string':
if (poparam.allowed.indexOf(typeof (val)) >= 0
&& val.length > 0) {
return true;
}
throw gpgme_error('PARAM_WRONG');
case 'number':
if (
poparam.allowed.indexOf('number') >= 0
&& isNaN(value) === false){
return true;
}
throw gpgme_error('PARAM_WRONG');
case 'boolean':
if (poparam.allowed.indexOf('boolean') >= 0){
return true;
}
throw gpgme_error('PARAM_WRONG');
case 'object':
if (Array.isArray(val)){
if (poparam.array_allowed !== true){
throw gpgme_error('PARAM_WRONG');
}
for (let i=0; i < val.length; i++){
let res = checktype(val[i]);
if (res !== true){
return res;
}
}
if (val.length > 0) {
return true;
}
} else if (val instanceof Uint8Array){
if (poparam.allowed.indexOf('Uint8Array') >= 0){
return true;
}
throw gpgme_error('PARAM_WRONG');
} else {
throw gpgme_error('PARAM_WRONG');
}
break;
default:
throw gpgme_error('PARAM_WRONG');
}
};
let typechecked = checktype(value);
if (typechecked !== true){
return typechecked;
}
if (poparam.hasOwnProperty('allowed_data')){
if (poparam.allowed_data.indexOf(value) < 0){
return gpgme_error('PARAM_WRONG');
}
}
this._msg[param] = value;
return true;
}
/**
* Check if the message has the minimum requirements to be sent, that is
* all 'required' parameters according to {@link permittedOperations}.
* @returns {Boolean} true if message is complete.
*/
isComplete (){
if (!this._msg.op){
return false;
}
let reqParams = Object.keys(
permittedOperations[this._msg.op].required);
let msg_params = Object.keys(this._msg);
for (let i=0; i < reqParams.length; i++){
if (msg_params.indexOf(reqParams[i]) < 0){
return false;
}
}
return true;
}
/**
* Sends the Message via nativeMessaging and resolves with the answer.
* @returns {Promise<Object>} GPGME response
* @async
*/
post (){
let me = this;
return new Promise(function (resolve, reject) {
if (me.isComplete() === true) {
let conn = new Connection;
conn.post(me).then(function (response) {
resolve(response);
}, function (reason) {
reject(reason);
});
}
else {
reject(gpgme_error('MSG_INCOMPLETE'));
}
});
}
}