summaryrefslogtreecommitdiff
path: root/lang/js/src/Message.js
blob: 9f6abb751baeb8b5ce5fd35f325b4798820fc9bb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
/* 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 <http://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'));
            }
        });
    }

}