xmppc/src/mode/openpgp.c
DebXWoody 24eab6f6e0
Bugfix OpenPGP / Key Lookup / signers
* Iterate list of UIDs for Key Lookup
 * Clean and set signers in context

Issue: #7 #8
2020-05-02 06:51:41 +02:00

275 lines
8.8 KiB
C

/*!
* @file openpgp.c
*
* vim: expandtab:ts=2:sts=2:sw=2
*
* @authors
* Copyright (C) 2020 Anoxinon e.V.
*
* @copyright
* This file is part of xmppc.
*
* xmppc 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.
*
* xmppc 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 Foobar. If not, see <http://www.gnu.org/licenses/>.
*
* German
*
* Diese Datei ist Teil von xmppc.
*
* xmppc ist Freie Software: Sie können es unter den Bedingungen
* der GNU General Public License, wie von der Free Software Foundation,
* Version 3 der Lizenz oder (nach Ihrer Wahl) jeder neueren
* veröffentlichten Version, weiter verteilen und/oder modifizieren.
*
* xmppc wird in der Hoffnung, dass es nützlich sein wird, aber
* OHNE JEDE GEWÄHRLEISTUNG, bereitgestellt; sogar ohne die implizite
* Gewährleistung der MARKTFÄHIGKEIT oder EIGNUNG FÜR EINEN BESTIMMTEN ZWECK.
* Siehe die GNU General Public License für weitere Details.
*
* Sie sollten eine Kopie der GNU General Public License zusammen mit diesem
* Programm erhalten haben. Wenn nicht, siehe <https://www.gnu.org/licenses/>.
*/
#define _GNU_SOURCE
#include "openpgp.h"
#include "string.h"
#include <locale.h>
#include <stdlib.h>
#include <glib.h>
#include <gpgme.h>
static void _openpgp_send_text(xmppc_t *xmppc, char* to, char* text);
static xmpp_stanza_t* _openpgp_signcrypt(xmppc_t *xmppc, char* to, char* text);
static char* _openpgp_gpg_signcrypt(xmppc_t *xmppc, char* recipient, char* message);
static gpgme_error_t _openpgp_lookup_key(xmppc_t *xmppc, char* name, gpgme_ctx_t* ctx, gpgme_key_t* key);
void openpgp_execute_command(xmppc_t *xmppc, int argc, char *argv[]) {
if(argc > 0) {
if(strcmp("signcrypt", argv[0]) == 0) {
_openpgp_send_text(xmppc, argv[1], argv[2]);
} else {
logError(xmppc, "Unbekanner Befehl: %s\n", argv[0]);
}
}
xmpp_disconnect(xmppc->conn);
}
void _openpgp_send_text(xmppc_t *xmppc, char* to, char* text) {
xmpp_conn_t *conn = xmppc->conn;
xmpp_stanza_t *message;
char* id = xmpp_uuid_gen(xmppc->ctx);
message = xmpp_message_new(xmpp_conn_get_context(conn), NULL, to, id);
xmpp_message_set_body(message, "This message is *encrypted* with OpenPGP (See :XEP:`0373`)");
xmpp_stanza_t *openpgp = xmpp_stanza_new(xmppc->ctx);
xmpp_stanza_set_name(openpgp, "openpgp");
xmpp_stanza_set_ns(openpgp, "urn:xmpp:openpgp:0");
xmpp_stanza_t * signcrypt = _openpgp_signcrypt(xmppc, to, text);
char* c;
size_t s;
xmpp_stanza_to_text(signcrypt, &c,&s);
char* signcrypt_e = _openpgp_gpg_signcrypt(xmppc,to, c);
if( signcrypt_e == NULL ) {
logError(xmppc, "Message not signcrypted.\n");
return;
}
// BASE64_OPENPGP_MESSAGE
xmpp_stanza_t* base64_openpgp_message = xmpp_stanza_new(xmppc->ctx);
xmpp_stanza_set_text(base64_openpgp_message,signcrypt_e);
xmpp_stanza_add_child(openpgp, base64_openpgp_message);
xmpp_stanza_add_child(message, openpgp);
xmpp_stanza_to_text(message, &c,&s);
xmpp_send(conn, message);
}
xmpp_stanza_t* _openpgp_signcrypt(xmppc_t *xmppc, char* to, char* text) {
time_t now = time(NULL);
struct tm* tm = localtime(&now);
char buf[255];
strftime(buf, sizeof(buf), "%FT%T%z", tm);
int randnr = rand() % 5;
char rpad_data[randnr];
for(int i = 0; i < randnr-1; i++) {
rpad_data[i] = 'c';
}
rpad_data[randnr-1] = '\0';
// signcrypt
xmpp_stanza_t *signcrypt = xmpp_stanza_new(xmppc->ctx);
xmpp_stanza_set_name(signcrypt, "signcrypt");
xmpp_stanza_set_ns(signcrypt, "urn:xmpp:openpgp:0");
// to
xmpp_stanza_t *s_to = xmpp_stanza_new(xmppc->ctx);
xmpp_stanza_set_name(s_to, "to");
xmpp_stanza_set_attribute(s_to, "jid", to);
// time
xmpp_stanza_t *time = xmpp_stanza_new(xmppc->ctx);
xmpp_stanza_set_name(time, "time");
xmpp_stanza_set_attribute(time, "stamp", buf);
xmpp_stanza_set_name(time, "time");
// rpad
xmpp_stanza_t *rpad = xmpp_stanza_new(xmppc->ctx);
xmpp_stanza_set_name(rpad, "rpad");
xmpp_stanza_t *rpad_text = xmpp_stanza_new(xmppc->ctx);
xmpp_stanza_set_text(rpad_text, rpad_data);
// payload
xmpp_stanza_t *payload= xmpp_stanza_new(xmppc->ctx);
xmpp_stanza_set_name(payload, "payload");
// body
xmpp_stanza_t *body = xmpp_stanza_new(xmppc->ctx);
xmpp_stanza_set_name(body, "body");
xmpp_stanza_set_ns(body, "jabber:client");
// text
xmpp_stanza_t *body_text = xmpp_stanza_new(xmppc->ctx);
xmpp_stanza_set_text(body_text, text);
xmpp_stanza_add_child(signcrypt,s_to);
xmpp_stanza_add_child(signcrypt,time);
xmpp_stanza_add_child(signcrypt,rpad);
xmpp_stanza_add_child(rpad,rpad_text);
xmpp_stanza_add_child(signcrypt,payload);
xmpp_stanza_add_child(payload, body);
xmpp_stanza_add_child(body, body_text);
return signcrypt;
}
char* _openpgp_gpg_signcrypt(xmppc_t *xmppc, char* recipient, char* message) {
setlocale (LC_ALL, "");
gpgme_check_version (NULL);
gpgme_set_locale (NULL, LC_CTYPE, setlocale (LC_CTYPE, NULL));
gpgme_ctx_t ctx;
gpgme_error_t error = gpgme_new (&ctx);
if(GPG_ERR_NO_ERROR != error ) {
printf("gpgme_new: %d\n", error);
return NULL;
}
error = gpgme_set_protocol(ctx, GPGME_PROTOCOL_OPENPGP);
if(error != 0) {
logError(xmppc,"GpgME Error: %s\n", gpgme_strerror(error));
}
gpgme_set_armor(ctx,0);
gpgme_set_textmode(ctx,0);
gpgme_set_offline(ctx,1);
gpgme_set_keylist_mode(ctx, GPGME_KEYLIST_MODE_LOCAL);
if(error != 0) {
logError(xmppc,"GpgME Error: %s\n", gpgme_strerror(error));
}
gpgme_key_t recp[3];
recp[0] = NULL,
recp[1] = NULL;
const char *jid = xmpp_conn_get_jid(xmppc->conn);
char* xmpp_jid_me = alloca( (strlen(jid)+6) * sizeof(char) );
char* xmpp_jid_recipient = alloca( (strlen(recipient)+6) * sizeof(char) );
strcpy(xmpp_jid_me, "xmpp:");
strcpy(xmpp_jid_recipient, "xmpp:");
strcat(xmpp_jid_me, jid);
strcat(xmpp_jid_recipient,recipient);
gpgme_signers_clear(ctx);
// lookup own key
error = _openpgp_lookup_key(xmppc,xmpp_jid_me, &ctx, &recp[0]);
if(error != 0) {
logError(xmppc,"Key not found for %s. GpgME Error: %s\n", xmpp_jid_me, gpgme_strerror(error));
return NULL;
}
error = gpgme_signers_add(ctx,recp[0]);
if(error != 0) {
logError(xmppc,"gpgme_signers_add %s. GpgME Error: %s\n", xmpp_jid_me, gpgme_strerror(error));
return NULL;
}
// lookup key of recipient
error = _openpgp_lookup_key(xmppc,xmpp_jid_recipient, &ctx, &recp[1]);
if(error != 0) {
logError(xmppc,"Key not found for %s. GpgME Error: %s\n", xmpp_jid_recipient, gpgme_strerror(error));
return NULL;
}
recp[2] = NULL;
logInfo(xmppc, "%s <%s>\n", recp[0]->uids->name, recp[0]->uids->email);
logInfo(xmppc, "%s <%s>\n", recp[1]->uids->name, recp[1]->uids->email);
#ifdef XMPPC_DEVELOPMENT
gpgme_encrypt_flags_t flags = GPGME_ENCRYPT_ALWAYS_TRUST;
#else
gpgme_encrypt_flags_t flags = 0;
#endif
gpgme_data_t plain;
gpgme_data_t cipher;
error = gpgme_data_new (&plain);
if(error != 0) {
logError(xmppc,"GpgME Error: %s\n", gpgme_strerror(error));
return NULL;
}
error = gpgme_data_new_from_mem(&plain, message, strlen(message),0);
if(error != 0) {
logError(xmppc,"GpgME Error: %s\n", gpgme_strerror(error));
return NULL;
}
error = gpgme_data_new (&cipher);
if(error != 0) {
logError(xmppc,"GpgME Error: %s\n", gpgme_strerror(error));
return NULL;
}
error = gpgme_op_encrypt_sign ( ctx, recp, flags, plain, cipher);
if(error != 0) {
logError(xmppc,"GpgME Error: %s\n", gpgme_strerror(error));
return NULL;
}
size_t len;
char *cipher_str = gpgme_data_release_and_get_mem(cipher, &len);
char* result = g_base64_encode( (unsigned char*) cipher_str,len);
gpgme_key_release (recp[0]);
gpgme_key_release (recp[1]);
gpgme_release (ctx);
return result;
}
gpgme_error_t _openpgp_lookup_key(xmppc_t *xmppc,char* name, gpgme_ctx_t* ctx, gpgme_key_t* key) {
logDebug(xmppc, "Looking for key: %s ...\n", name);
gpgme_error_t error = gpgme_op_keylist_start (*ctx, NULL, 0);
while (!error) {
error = gpgme_op_keylist_next (*ctx, key);
if(!error) {
gpgme_user_id_t uids = (*key)->uids;
while (uids) {
if(strcmp(uids->name, name) == 0) {
logDebug(xmppc, "Key found: %s ...\n", uids->name);
return error;
}
uids=uids->next;
}
} else {
gpgme_key_release((*key));
}
}
return error;
}