1/*!
2 * @file pgp.c
3 *
4 * vim: expandtab:ts=2:sts=2:sw=2
5 *
6 * @authors
7 * Copyright (C) 2020 Anoxinon e.V.
8 *
9 * @copyright
10 * This file is part of xmppc.
11 *
12 * xmppc is free software: you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation, either version 3 of the License, or
15 * (at your option) any later version.
16 *
17 * xmppc is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with Foobar. If not, see <http://www.gnu.org/licenses/>.
24 *
25 * German
26 *
27 * Diese Datei ist Teil von xmppc.
28 *
29 * xmppc ist Freie Software: Sie können es unter den Bedingungen
30 * der GNU General Public License, wie von der Free Software Foundation,
31 * Version 3 der Lizenz oder (nach Ihrer Wahl) jeder neueren
32 * veröffentlichten Version, weiter verteilen und/oder modifizieren.
33 *
34 * xmppc wird in der Hoffnung, dass es nützlich sein wird, aber
35 * OHNE JEDE GEWÄHRLEISTUNG, bereitgestellt; sogar ohne die implizite
36 * Gewährleistung der MARKTFÄHIGKEIT oder EIGNUNG FÜR EINEN BESTIMMTEN ZWECK.
37 * Siehe die GNU General Public License für weitere Details.
38 *
39 * Sie sollten eine Kopie der GNU General Public License zusammen mit diesem
40 * Programm erhalten haben. Wenn nicht, siehe <https://www.gnu.org/licenses/>.
41 */
42
43#define _GNU_SOURCE
44
45#include "pgp.h"
46#include "string.h"
47
48#include <locale.h>
49#include <stdlib.h>
50#include <gpgme.h>
51
52#define PGP_BEGIN "-----BEGIN PGP MESSAGE-----"
53#define PGP_END "-----END PGP MESSAGE-----"
54
55static char* _pgp_encrypt_message(xmppc_t *xmppc, char* recipient, char* message);
56static char* _pgp_remove_PGP_MESSAGE_comment(const char* message);
57
58static void _pgp_send_text(xmppc_t *xmppc, char* to, char* text);
59
60void pgp_execute_command(xmppc_t *xmppc, int argc, char *argv[]) {
61 if(argc > 0) {
62 if(strcmp("chat", argv[0]) == 0) {
63 _pgp_send_text(xmppc, argv[1], argv[2]);
64 } else {
65 logError(xmppc, "Unbekanner Befehl: %s\n", argv[0]);
66 }
67 }
68 sleep(10);
69 xmpp_disconnect(xmppc->conn);
70}
71
72void _pgp_send_text(xmppc_t *xmppc, char* to, char* text) {
73 xmpp_conn_t *conn = xmppc->conn;
74 xmpp_stanza_t *message;
75 char* id = xmpp_uuid_gen(xmppc->ctx);
76 message = xmpp_message_new(xmpp_conn_get_context(conn), "chat", to, id);
77 int res = xmpp_message_set_body(message, "This message is *encrypted* with PGP (See :XEP:`27`)");
78 if(res == 0) {
79 xmpp_stanza_t *x = xmpp_stanza_new(xmppc->ctx);
80 xmpp_stanza_set_name(x, "x");
81 xmpp_stanza_set_ns(x, "jabber:x:encrypted");
82 xmpp_stanza_t *b = xmpp_stanza_new(xmppc->ctx);
83 char* encrypt_text = _pgp_encrypt_message(xmppc, to,text);
84 if(encrypt_text == NULL) {
85 logError(xmppc,"Encrypting of message failed.\n");
86 return;
87 }
88 xmpp_stanza_set_text(b,encrypt_text);
89 xmpp_stanza_add_child(x, b);
90 xmpp_stanza_add_child(message, x);
91 xmpp_stanza_t *e = xmpp_stanza_new(xmppc->ctx);
92 xmpp_stanza_set_name(e, "encryption");
93 xmpp_stanza_set_ns(e, "urn:xmpp:eme:0");
94 xmpp_stanza_set_attribute(e, "namespace", "jabber:x:encrypted");
95 xmpp_stanza_add_child(message, e);
96 xmpp_send(conn, message);
97 }
98}
99
100char* _pgp_encrypt_message(xmppc_t *xmppc, char* recipient, char* message) {
101 setlocale (LC_ALL, "");
102 gpgme_check_version (NULL);
103 gpgme_set_locale (NULL, LC_CTYPE, setlocale (LC_CTYPE, NULL));
104 gpgme_ctx_t ctx;
105 gpgme_error_t error = gpgme_new (&ctx);
106 if(GPG_ERR_NO_ERROR != error ) {
107 printf("gpgme_new: %d\n", error);
108 return NULL;
109 }
110 error = gpgme_set_protocol(ctx, GPGME_PROTOCOL_OPENPGP);
111 if(error != 0) {
112 logError(xmppc,"GpgME Error: %s\n", gpgme_strerror(error));
113 }
114 gpgme_set_armor(ctx,1);
115 gpgme_set_textmode(ctx,1);
116 gpgme_set_offline(ctx,1);
117 gpgme_set_keylist_mode(ctx, GPGME_KEYLIST_MODE_LOCAL);
118
119 gpgme_key_t recp[3];
120
121 // Key for sender
122 const char *jid = xmpp_conn_get_jid(xmppc->conn);
123 logInfo(xmppc, "Looking up pgp key for %s\n", jid);
124 error = gpgme_get_key(ctx, jid, &(recp[0]), 0);
125 if(error != 0) {
126 logError(xmppc,"Public key not found for %s. GpgME Error: %s\n", jid, gpgme_strerror(error));
127 return NULL;
128 }
129
130 // Key for recipient
131 logInfo(xmppc, "Looking up pgp key for %s\n", recipient);
132 error = gpgme_get_key(ctx, recipient, &(recp[1]), 0);
133 if(error != 0) {
134 logError(xmppc,"Key not found for %s. GpgME Error: %s\n", recipient, gpgme_strerror(error));
135 return NULL;
136 }
137 recp[2] = NULL;
138
139 logInfo(xmppc, "%s <%s>\n", recp[0]->uids->name, recp[0]->uids->email);
140 logInfo(xmppc, "%s <%s>\n", recp[1]->uids->name, recp[1]->uids->email);
141
142 gpgme_encrypt_flags_t flags = 0;
143 gpgme_data_t plain;
144 gpgme_data_t cipher;
145
146 error = gpgme_data_new (&plain);
147 if(error != 0) {
148 logError(xmppc,"GpgME Error: %s\n", gpgme_strerror(error));
149 }
150
151 error = gpgme_data_new_from_mem(&plain, message, strlen(message),0);
152 if(error != 0) {
153 logError(xmppc,"GpgME Error: %s\n", gpgme_strerror(error));
154 }
155 error = gpgme_data_new (&cipher);
156 if(error != 0) {
157 logError(xmppc,"GpgME Error: %s\n", gpgme_strerror(error));
158 }
159
160 error = gpgme_op_encrypt ( ctx, recp, flags, plain, cipher);
161 if(error != 0) {
162 logError(xmppc,"GpgME Error: %s\n", gpgme_strerror(error));
163 }
164 size_t len;
165 char *cipher_str = gpgme_data_release_and_get_mem(cipher, &len);
166 char* result = NULL;
167 if(len > 0 ){
168 result = _pgp_remove_PGP_MESSAGE_comment(cipher_str);
169 }
170
171 gpgme_key_release (recp[0]);
172 gpgme_key_release (recp[1]);
173 gpgme_release (ctx);
174 return result;
175}
176
177static char* _pgp_remove_PGP_MESSAGE_comment(const char* message) {
178 char* tmp = strndupa(message, strlen(message) - (strlen(PGP_END)+1));
179 tmp = tmp+((strlen(PGP_BEGIN) +1) * sizeof(char));
180 char* result = malloc(strlen(tmp)+1);
181 strcpy(result, tmp);
182 return result;
183}