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profanity/src/omemo/omemo.c

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/*
* omemo.c
* vim: expandtab:ts=4:sts=4:sw=4
*
* Copyright (C) 2019 Paul Fariello <paul@fariello.eu>
* Copyright (C) 2019 - 2021 Michael Vetter <jubalh@iodoru.org>
*
* This file is part of Profanity.
*
* Profanity 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.
*
* Profanity 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 Profanity. If not, see <https://www.gnu.org/licenses/>.
*
* In addition, as a special exception, the copyright holders give permission to
* link the code of portions of this program with the OpenSSL library under
* certain conditions as described in each individual source file, and
* distribute linked combinations including the two.
*
* You must obey the GNU General Public License in all respects for all of the
* code used other than OpenSSL. If you modify file(s) with this exception, you
* may extend this exception to your version of the file(s), but you are not
* obligated to do so. If you do not wish to do so, delete this exception
* statement from your version. If you delete this exception statement from all
* source files in the program, then also delete it here.
*
*/
#include "config.h"
#include <sys/time.h>
#include <sys/stat.h>
#include <assert.h>
#include <errno.h>
#include <glib.h>
#include <pthread.h>
#include <signal/key_helper.h>
#include <signal/protocol.h>
#include <signal/signal_protocol.h>
#include <signal/session_builder.h>
#include <signal/session_cipher.h>
#include "config/account.h"
#include "config/files.h"
#include "config/preferences.h"
#include "log.h"
#include "omemo/crypto.h"
#include "omemo/omemo.h"
#include "omemo/store.h"
#include "ui/ui.h"
#include "ui/window_list.h"
#include "xmpp/connection.h"
#include "xmpp/muc.h"
#include "xmpp/omemo.h"
#include "xmpp/roster_list.h"
#include "xmpp/xmpp.h"
#define AESGCM_URL_NONCE_LEN (2 * OMEMO_AESGCM_NONCE_LENGTH)
#define AESGCM_URL_KEY_LEN (2 * OMEMO_AESGCM_KEY_LENGTH)
static gboolean loaded;
static void _generate_pre_keys(int count);
static void _generate_signed_pre_key(void);
static gboolean _load_identity(void);
static void _load_trust(void);
static void _load_sessions(void);
static void _load_known_devices(void);
static void _lock(void* user_data);
static void _unlock(void* user_data);
static void _omemo_log(int level, const char* message, size_t len, void* user_data);
static gboolean _handle_own_device_list(const char* const jid, GList* device_list);
static gboolean _handle_device_list_start_session(const char* const jid, GList* device_list);
static char* _omemo_fingerprint(ec_public_key* identity, gboolean formatted);
static unsigned char* _omemo_fingerprint_decode(const char* const fingerprint, size_t* len);
static char* _omemo_unformat_fingerprint(const char* const fingerprint_formatted);
static void _cache_device_identity(const char* const jid, uint32_t device_id, ec_public_key* identity);
static void _g_hash_table_free(GHashTable* hash_table);
static void _acquire_sender_devices_list(void);
typedef gboolean (*OmemoDeviceListHandler)(const char* const jid, GList* device_list);
struct omemo_context_t
{
pthread_mutexattr_t attr;
pthread_mutex_t lock;
signal_context* signal;
uint32_t device_id;
GHashTable* device_list;
GHashTable* device_list_handler;
ratchet_identity_key_pair* identity_key_pair;
uint32_t registration_id;
uint32_t signed_pre_key_id;
signal_protocol_store_context* store;
GHashTable* session_store;
GHashTable* pre_key_store;
GHashTable* signed_pre_key_store;
identity_key_store_t identity_key_store;
GString* identity_filename;
GKeyFile* identity_keyfile;
GString* trust_filename;
GKeyFile* trust_keyfile;
GString* sessions_filename;
GKeyFile* sessions_keyfile;
GHashTable* known_devices;
GString* known_devices_filename;
GKeyFile* known_devices_keyfile;
GHashTable* fingerprint_ac;
};
static omemo_context omemo_ctx;
void
omemo_init(void)
{
log_info("[OMEMO] initialising");
if (omemo_crypto_init() != 0) {
cons_show("Error initializing OMEMO crypto: gcry_check_version() failed");
}
pthread_mutexattr_init(&omemo_ctx.attr);
pthread_mutexattr_settype(&omemo_ctx.attr, PTHREAD_MUTEX_RECURSIVE);
pthread_mutex_init(&omemo_ctx.lock, &omemo_ctx.attr);
omemo_ctx.fingerprint_ac = g_hash_table_new_full(g_str_hash, g_str_equal, free, (GDestroyNotify)autocomplete_free);
}
void
omemo_close(void)
{
if (omemo_ctx.fingerprint_ac) {
g_hash_table_destroy(omemo_ctx.fingerprint_ac);
omemo_ctx.fingerprint_ac = NULL;
}
}
void
omemo_on_connect(ProfAccount* account)
{
GError* error = NULL;
if (signal_context_create(&omemo_ctx.signal, &omemo_ctx) != 0) {
cons_show("Error initializing OMEMO context");
return;
}
if (signal_context_set_log_function(omemo_ctx.signal, _omemo_log) != 0) {
cons_show("Error initializing OMEMO log");
}
signal_crypto_provider crypto_provider = {
.random_func = omemo_random_func,
.hmac_sha256_init_func = omemo_hmac_sha256_init_func,
.hmac_sha256_update_func = omemo_hmac_sha256_update_func,
.hmac_sha256_final_func = omemo_hmac_sha256_final_func,
.hmac_sha256_cleanup_func = omemo_hmac_sha256_cleanup_func,
.sha512_digest_init_func = omemo_sha512_digest_init_func,
.sha512_digest_update_func = omemo_sha512_digest_update_func,
.sha512_digest_final_func = omemo_sha512_digest_final_func,
.sha512_digest_cleanup_func = omemo_sha512_digest_cleanup_func,
.encrypt_func = omemo_encrypt_func,
.decrypt_func = omemo_decrypt_func,
.user_data = NULL
};
if (signal_context_set_crypto_provider(omemo_ctx.signal, &crypto_provider) != 0) {
cons_show("Error initializing OMEMO crypto: unable to set crypto provider");
return;
}
signal_context_set_locking_functions(omemo_ctx.signal, _lock, _unlock);
signal_protocol_store_context_create(&omemo_ctx.store, omemo_ctx.signal);
omemo_ctx.session_store = session_store_new();
signal_protocol_session_store session_store = {
.load_session_func = load_session,
.get_sub_device_sessions_func = get_sub_device_sessions,
.store_session_func = store_session,
.contains_session_func = contains_session,
.delete_session_func = delete_session,
.delete_all_sessions_func = delete_all_sessions,
.destroy_func = NULL,
.user_data = omemo_ctx.session_store
};
signal_protocol_store_context_set_session_store(omemo_ctx.store, &session_store);
omemo_ctx.pre_key_store = pre_key_store_new();
signal_protocol_pre_key_store pre_key_store = {
.load_pre_key = load_pre_key,
.store_pre_key = store_pre_key,
.contains_pre_key = contains_pre_key,
.remove_pre_key = remove_pre_key,
.destroy_func = NULL,
.user_data = omemo_ctx.pre_key_store
};
signal_protocol_store_context_set_pre_key_store(omemo_ctx.store, &pre_key_store);
omemo_ctx.signed_pre_key_store = signed_pre_key_store_new();
signal_protocol_signed_pre_key_store signed_pre_key_store = {
.load_signed_pre_key = load_signed_pre_key,
.store_signed_pre_key = store_signed_pre_key,
.contains_signed_pre_key = contains_signed_pre_key,
.remove_signed_pre_key = remove_signed_pre_key,
.destroy_func = NULL,
.user_data = omemo_ctx.signed_pre_key_store
};
signal_protocol_store_context_set_signed_pre_key_store(omemo_ctx.store, &signed_pre_key_store);
identity_key_store_new(&omemo_ctx.identity_key_store);
signal_protocol_identity_key_store identity_key_store = {
.get_identity_key_pair = get_identity_key_pair,
.get_local_registration_id = get_local_registration_id,
.save_identity = save_identity,
.is_trusted_identity = is_trusted_identity,
.destroy_func = NULL,
.user_data = &omemo_ctx.identity_key_store
};
signal_protocol_store_context_set_identity_key_store(omemo_ctx.store, &identity_key_store);
loaded = FALSE;
omemo_ctx.device_list = g_hash_table_new_full(g_str_hash, g_str_equal, free, (GDestroyNotify)g_list_free);
omemo_ctx.device_list_handler = g_hash_table_new_full(g_str_hash, g_str_equal, free, NULL);
omemo_ctx.known_devices = g_hash_table_new_full(g_str_hash, g_str_equal, free, (GDestroyNotify)_g_hash_table_free);
gchar* omemo_dir = files_get_account_data_path(DIR_OMEMO, account->jid);
omemo_ctx.identity_filename = g_string_new(omemo_dir);
g_string_append(omemo_ctx.identity_filename, "/identity.txt");
omemo_ctx.trust_filename = g_string_new(omemo_dir);
g_string_append(omemo_ctx.trust_filename, "/trust.txt");
omemo_ctx.sessions_filename = g_string_new(omemo_dir);
g_string_append(omemo_ctx.sessions_filename, "/sessions.txt");
omemo_ctx.known_devices_filename = g_string_new(omemo_dir);
g_string_append(omemo_ctx.known_devices_filename, "/known_devices.txt");
errno = 0;
int res = g_mkdir_with_parents(omemo_dir, S_IRWXU);
if (res == -1) {
const char* errmsg = strerror(errno);
if (errmsg) {
log_error("[OMEMO] error creating directory: %s, %s", omemo_dir, errmsg);
} else {
log_error("[OMEMO] creating directory: %s", omemo_dir);
}
}
g_free(omemo_dir);
omemo_devicelist_subscribe();
omemo_ctx.identity_keyfile = g_key_file_new();
omemo_ctx.trust_keyfile = g_key_file_new();
omemo_ctx.sessions_keyfile = g_key_file_new();
omemo_ctx.known_devices_keyfile = g_key_file_new();
if (g_key_file_load_from_file(omemo_ctx.identity_keyfile, omemo_ctx.identity_filename->str, G_KEY_FILE_KEEP_COMMENTS, &error)) {
if (!_load_identity()) {
return;
}
} else if (error->code != G_FILE_ERROR_NOENT) {
log_warning("[OMEMO] error loading identity from: %s, %s", omemo_ctx.identity_filename->str, error->message);
g_error_free(error);
return;
}
error = NULL;
if (g_key_file_load_from_file(omemo_ctx.trust_keyfile, omemo_ctx.trust_filename->str, G_KEY_FILE_KEEP_COMMENTS, &error)) {
_load_trust();
} else if (error->code != G_FILE_ERROR_NOENT) {
log_warning("[OMEMO] error loading trust from: %s, %s", omemo_ctx.trust_filename->str, error->message);
g_error_free(error);
} else {
log_warning("[OMEMO] no such file: %s", omemo_ctx.trust_filename->str);
g_error_free(error);
}
error = NULL;
if (g_key_file_load_from_file(omemo_ctx.sessions_keyfile, omemo_ctx.sessions_filename->str, G_KEY_FILE_KEEP_COMMENTS, &error)) {
_load_sessions();
} else if (error->code != G_FILE_ERROR_NOENT) {
log_warning("[OMEMO] error loading sessions from: %s, %s", omemo_ctx.sessions_filename->str, error->message);
g_error_free(error);
} else {
log_warning("[OMEMO] no such file: %s", omemo_ctx.trust_filename->str);
g_error_free(error);
}
error = NULL;
if (g_key_file_load_from_file(omemo_ctx.known_devices_keyfile, omemo_ctx.known_devices_filename->str, G_KEY_FILE_KEEP_COMMENTS, &error)) {
_load_known_devices();
} else if (error->code != G_FILE_ERROR_NOENT) {
log_warning("[OMEMO] error loading known devices from: %s, %s", omemo_ctx.known_devices_filename->str, error->message);
g_error_free(error);
} else {
log_warning("[OMEMO] no such file: %s", omemo_ctx.trust_filename->str);
g_error_free(error);
}
}
void
omemo_on_disconnect(void)
{
if (!loaded) {
return;
}
_g_hash_table_free(omemo_ctx.signed_pre_key_store);
_g_hash_table_free(omemo_ctx.pre_key_store);
_g_hash_table_free(omemo_ctx.device_list_handler);
g_string_free(omemo_ctx.identity_filename, TRUE);
g_key_file_free(omemo_ctx.identity_keyfile);
g_string_free(omemo_ctx.trust_filename, TRUE);
g_key_file_free(omemo_ctx.trust_keyfile);
g_string_free(omemo_ctx.sessions_filename, TRUE);
g_key_file_free(omemo_ctx.sessions_keyfile);
_g_hash_table_free(omemo_ctx.session_store);
g_string_free(omemo_ctx.known_devices_filename, TRUE);
g_key_file_free(omemo_ctx.known_devices_keyfile);
}
void
omemo_generate_crypto_materials(ProfAccount* account)
{
if (loaded) {
return;
}
log_info("Generate long term OMEMO cryptography materials");
/* Device ID */
gcry_randomize(&omemo_ctx.device_id, 4, GCRY_VERY_STRONG_RANDOM);
omemo_ctx.device_id &= 0x7fffffff;
g_key_file_set_uint64(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_IDENTITY, OMEMO_STORE_KEY_DEVICE_ID, omemo_ctx.device_id);
log_info("[OMEMO] device id: %d", omemo_ctx.device_id);
/* Identity key */
signal_protocol_key_helper_generate_identity_key_pair(&omemo_ctx.identity_key_pair, omemo_ctx.signal);
ec_public_key_serialize(&omemo_ctx.identity_key_store.public, ratchet_identity_key_pair_get_public(omemo_ctx.identity_key_pair));
char* identity_key_public = g_base64_encode(signal_buffer_data(omemo_ctx.identity_key_store.public), signal_buffer_len(omemo_ctx.identity_key_store.public));
g_key_file_set_string(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_IDENTITY, OMEMO_STORE_KEY_IDENTITY_KEY_PUBLIC, identity_key_public);
g_free(identity_key_public);
ec_private_key_serialize(&omemo_ctx.identity_key_store.private, ratchet_identity_key_pair_get_private(omemo_ctx.identity_key_pair));
char* identity_key_private = g_base64_encode(signal_buffer_data(omemo_ctx.identity_key_store.private), signal_buffer_len(omemo_ctx.identity_key_store.private));
g_key_file_set_string(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_IDENTITY, OMEMO_STORE_KEY_IDENTITY_KEY_PRIVATE, identity_key_private);
g_free(identity_key_private);
/* Registration ID */
signal_protocol_key_helper_generate_registration_id(&omemo_ctx.registration_id, 0, omemo_ctx.signal);
g_key_file_set_uint64(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_IDENTITY, OMEMO_STORE_KEY_REGISTRATION_ID, omemo_ctx.registration_id);
/* Pre keys */
_generate_pre_keys(100);
/* Signed pre key */
_generate_signed_pre_key();
omemo_identity_keyfile_save();
loaded = TRUE;
omemo_publish_crypto_materials();
omemo_start_sessions();
}
void
omemo_publish_crypto_materials(void)
{
log_debug("[OMEMO] publish crypto materials");
if (loaded != TRUE) {
cons_show("OMEMO: cannot publish crypto materials before they are generated");
log_error("[OMEMO] cannot publish crypto materials before they are generated");
return;
}
omemo_bundle_publish(true);
}
static void
_acquire_sender_devices_list(void)
{
char* barejid = connection_get_barejid();
g_hash_table_insert(omemo_ctx.device_list_handler, strdup(barejid), _handle_own_device_list);
omemo_devicelist_request(barejid);
free(barejid);
}
void
omemo_start_sessions(void)
{
// before any session may be started, a list on
// available sender devices must be acquired
log_debug("[OMEMO] Acquiring sender devices list");
_acquire_sender_devices_list();
GSList* contacts = roster_get_contacts(ROSTER_ORD_NAME);
if (contacts) {
GSList* curr;
for (curr = contacts; curr != NULL; curr = g_slist_next(curr)) {
PContact contact = curr->data;
const char* jid = p_contact_barejid(contact);
omemo_start_session(jid);
}
g_slist_free(contacts);
}
}
void
omemo_start_session(const char* const barejid)
{
if (omemo_loaded()) {
log_debug("[OMEMO] start session with %s", barejid);
GList* device_list = g_hash_table_lookup(omemo_ctx.device_list, barejid);
if (!device_list) {
log_debug("[OMEMO] missing device list for %s", barejid);
// Own devices are handled by _handle_own_device_list
// We won't add _handle_device_list_start_session for ourself
char* mybarejid = connection_get_barejid();
if (g_strcmp0(mybarejid, barejid) != 0) {
g_hash_table_insert(omemo_ctx.device_list_handler, strdup(barejid), _handle_device_list_start_session);
}
free(mybarejid);
omemo_devicelist_request(barejid);
return;
}
GList* device_id;
for (device_id = device_list; device_id != NULL; device_id = device_id->next) {
omemo_bundle_request(barejid, GPOINTER_TO_INT(device_id->data), omemo_start_device_session_handle_bundle, free, strdup(barejid));
}
}
}
void
omemo_start_muc_sessions(const char* const roomjid)
{
GList* members = muc_members(roomjid);
GList* iter;
for (iter = members; iter != NULL; iter = iter->next) {
Jid* jid = jid_create(iter->data);
omemo_start_session(jid->barejid);
jid_destroy(jid);
}
g_list_free(members);
}
gboolean
omemo_loaded(void)
{
return loaded;
}
uint32_t
omemo_device_id(void)
{
return omemo_ctx.device_id;
}
void
omemo_identity_key(unsigned char** output, size_t* length)
{
signal_buffer* buffer = NULL;
ec_public_key_serialize(&buffer, ratchet_identity_key_pair_get_public(omemo_ctx.identity_key_pair));
*length = signal_buffer_len(buffer);
*output = malloc(*length);
memcpy(*output, signal_buffer_data(buffer), *length);
signal_buffer_free(buffer);
}
void
omemo_signed_prekey(unsigned char** output, size_t* length)
{
session_signed_pre_key* signed_pre_key;
signal_buffer* buffer = NULL;
if (signal_protocol_signed_pre_key_load_key(omemo_ctx.store, &signed_pre_key, omemo_ctx.signed_pre_key_id) != SG_SUCCESS) {
*output = NULL;
*length = 0;
return;
}
ec_public_key_serialize(&buffer, ec_key_pair_get_public(session_signed_pre_key_get_key_pair(signed_pre_key)));
SIGNAL_UNREF(signed_pre_key);
*length = signal_buffer_len(buffer);
*output = malloc(*length);
memcpy(*output, signal_buffer_data(buffer), *length);
signal_buffer_free(buffer);
}
void
omemo_signed_prekey_signature(unsigned char** output, size_t* length)
{
session_signed_pre_key* signed_pre_key;
if (signal_protocol_signed_pre_key_load_key(omemo_ctx.store, &signed_pre_key, omemo_ctx.signed_pre_key_id) != SG_SUCCESS) {
*output = NULL;
*length = 0;
return;
}
*length = session_signed_pre_key_get_signature_len(signed_pre_key);
*output = malloc(*length);
memcpy(*output, session_signed_pre_key_get_signature(signed_pre_key), *length);
SIGNAL_UNREF(signed_pre_key);
}
void
omemo_prekeys(GList** prekeys, GList** ids, GList** lengths)
{
GHashTableIter iter;
gpointer id;
g_hash_table_iter_init(&iter, omemo_ctx.pre_key_store);
while (g_hash_table_iter_next(&iter, &id, NULL)) {
session_pre_key* pre_key;
int ret;
ret = signal_protocol_pre_key_load_key(omemo_ctx.store, &pre_key, GPOINTER_TO_INT(id));
if (ret != SG_SUCCESS) {
continue;
}
signal_buffer* public_key;
ec_public_key_serialize(&public_key, ec_key_pair_get_public(session_pre_key_get_key_pair(pre_key)));
SIGNAL_UNREF(pre_key);
size_t length = signal_buffer_len(public_key);
unsigned char* prekey_value = malloc(length);
memcpy(prekey_value, signal_buffer_data(public_key), length);
signal_buffer_free(public_key);
*prekeys = g_list_append(*prekeys, prekey_value);
*ids = g_list_append(*ids, GINT_TO_POINTER(id));
*lengths = g_list_append(*lengths, GINT_TO_POINTER(length));
}
}
void
omemo_set_device_list(const char* const from, GList* device_list)
{
log_debug("[OMEMO] Setting device list for %s", from);
Jid* jid;
if (from) {
jid = jid_create(from);
} else {
jid = jid_create(connection_get_fulljid());
}
g_hash_table_insert(omemo_ctx.device_list, strdup(jid->barejid), device_list);
OmemoDeviceListHandler handler = g_hash_table_lookup(omemo_ctx.device_list_handler, jid->barejid);
if (handler) {
gboolean keep = handler(jid->barejid, device_list);
if (!keep) {
g_hash_table_remove(omemo_ctx.device_list_handler, jid->barejid);
}
} else {
log_debug("[OMEMO] No Device List Handler for %s", from);
}
// OMEMO trustmode ToFu
if (g_strcmp0(prefs_get_string(PREF_OMEMO_TRUST_MODE), "firstusage") == 0) {
log_debug("[OMEMO] Checking firstusage state for %s", jid->barejid);
GHashTable* trusted = g_hash_table_lookup(omemo_ctx.identity_key_store.trusted, jid->barejid);
if (trusted) {
if (g_hash_table_size(trusted) > 0) {
log_debug("[OMEMO] Found trusted device for %s - skip firstusage", jid->barejid);
return;
}
} else {
if (device_list) {
cons_show("OMEMO: No trusted devices found for %s", jid->barejid);
GList* device_id;
for (device_id = device_list; device_id != NULL; device_id = device_id->next) {
GHashTable* known_identities = g_hash_table_lookup(omemo_ctx.known_devices, jid->barejid);
if (known_identities) {
GList* fp = NULL;
for (fp = g_hash_table_get_keys(known_identities); fp != NULL; fp = fp->next) {
if (device_id->data == g_hash_table_lookup(known_identities, fp->data)) {
cons_show("OMEMO: Adding firstusage trust for %s device %d - Fingerprint %s", jid->barejid, device_id->data, omemo_format_fingerprint(fp->data));
omemo_trust(jid->barejid, omemo_format_fingerprint(fp->data));
}
}
}
}
}
}
}
jid_destroy(jid);
}
GKeyFile*
omemo_identity_keyfile(void)
{
return omemo_ctx.identity_keyfile;
}
void
omemo_identity_keyfile_save(void)
{
GError* error = NULL;
if (!g_key_file_save_to_file(omemo_ctx.identity_keyfile, omemo_ctx.identity_filename->str, &error)) {
log_error("[OMEMO] error saving identity to: %s, %s", omemo_ctx.identity_filename->str, error->message);
}
}
GKeyFile*
omemo_trust_keyfile(void)
{
return omemo_ctx.trust_keyfile;
}
void
omemo_trust_keyfile_save(void)
{
GError* error = NULL;
if (!g_key_file_save_to_file(omemo_ctx.trust_keyfile, omemo_ctx.trust_filename->str, &error)) {
log_error("[OMEMO] error saving trust to: %s, %s", omemo_ctx.trust_filename->str, error->message);
}
}
GKeyFile*
omemo_sessions_keyfile(void)
{
return omemo_ctx.sessions_keyfile;
}
void
omemo_sessions_keyfile_save(void)
{
GError* error = NULL;
if (!g_key_file_save_to_file(omemo_ctx.sessions_keyfile, omemo_ctx.sessions_filename->str, &error)) {
log_error("[OMEMO] error saving sessions to: %s, %s", omemo_ctx.sessions_filename->str, error->message);
}
}
void
omemo_known_devices_keyfile_save(void)
{
GError* error = NULL;
if (!g_key_file_save_to_file(omemo_ctx.known_devices_keyfile, omemo_ctx.known_devices_filename->str, &error)) {
log_error("[OMEMO] error saving known devices to: %s, %s", omemo_ctx.known_devices_filename->str, error->message);
}
}
void
omemo_start_device_session(const char* const jid, uint32_t device_id,
GList* prekeys, uint32_t signed_prekey_id,
const unsigned char* const signed_prekey_raw, size_t signed_prekey_len,
const unsigned char* const signature, size_t signature_len,
const unsigned char* const identity_key_raw, size_t identity_key_len)
{
log_debug("[OMEMO] Starting device session for %s with device %d", jid, device_id);
signal_protocol_address address = {
.name = jid,
.name_len = strlen(jid),
.device_id = device_id,
};
ec_public_key* identity_key;
curve_decode_point(&identity_key, identity_key_raw, identity_key_len, omemo_ctx.signal);
_cache_device_identity(jid, device_id, identity_key);
gboolean trusted = is_trusted_identity(&address, (uint8_t*)identity_key_raw, identity_key_len, &omemo_ctx.identity_key_store);
log_debug("[OMEMO] Trust %s (%d): %d", jid, device_id, trusted);
if ((g_strcmp0(prefs_get_string(PREF_OMEMO_TRUST_MODE), "blind") == 0) && !trusted) {
char* fp = _omemo_fingerprint(identity_key, TRUE);
cons_show("Blind trust for %s device %d (%s)", jid, device_id, fp);
omemo_trust(jid, fp);
free(fp);
trusted = TRUE;
}
if (!trusted) {
log_debug("[OMEMO] We don't trust device %d for %s\n", device_id, jid);
goto out;
}
if (!contains_session(&address, omemo_ctx.session_store)) {
log_debug("[OMEMO] There is no Session for %s ( %d) ,... building session.", address.name, address.device_id);
int res;
session_pre_key_bundle* bundle;
signal_protocol_address* address;
address = malloc(sizeof(signal_protocol_address));
address->name = strdup(jid);
address->name_len = strlen(jid);
address->device_id = device_id;
session_builder* builder;
res = session_builder_create(&builder, omemo_ctx.store, address, omemo_ctx.signal);
if (res != 0) {
log_error("[OMEMO] cannot create session builder for %s device %d", jid, device_id);
goto out;
}
int prekey_index;
gcry_randomize(&prekey_index, sizeof(int), GCRY_STRONG_RANDOM);
prekey_index %= g_list_length(prekeys);
omemo_key_t* prekey = g_list_nth_data(prekeys, prekey_index);
ec_public_key* prekey_public;
curve_decode_point(&prekey_public, prekey->data, prekey->length, omemo_ctx.signal);
ec_public_key* signed_prekey;
curve_decode_point(&signed_prekey, signed_prekey_raw, signed_prekey_len, omemo_ctx.signal);
res = session_pre_key_bundle_create(&bundle, 0, device_id, prekey->id, prekey_public, signed_prekey_id, signed_prekey, signature, signature_len, identity_key);
if (res != 0) {
log_error("[OMEMO] cannot create pre key bundle for %s device %d", jid, device_id);
goto out;
}
res = session_builder_process_pre_key_bundle(builder, bundle);
if (res != 0) {
log_error("[OMEMO] cannot process pre key bundle for %s device %d", jid, device_id);
goto out;
}
log_debug("[OMEMO] create session with %s device %d", jid, device_id);
} else {
log_debug("[OMEMO] session with %s device %d exists", jid, device_id);
}
out:
SIGNAL_UNREF(identity_key);
}
char*
omemo_on_message_send(ProfWin* win, const char* const message, gboolean request_receipt, gboolean muc, const char* const replace_id)
{
char* id = NULL;
int res;
Jid* jid = jid_create(connection_get_fulljid());
GList* keys = NULL;
unsigned char* key;
unsigned char* iv;
unsigned char* ciphertext;
unsigned char* tag;
unsigned char* key_tag;
size_t ciphertext_len, tag_len;
ciphertext_len = strlen(message);
ciphertext = malloc(ciphertext_len);
tag_len = AES128_GCM_TAG_LENGTH;
tag = gcry_malloc_secure(tag_len);
key_tag = gcry_malloc_secure(AES128_GCM_KEY_LENGTH + AES128_GCM_TAG_LENGTH);
key = gcry_random_bytes_secure(AES128_GCM_KEY_LENGTH, GCRY_VERY_STRONG_RANDOM);
iv = gcry_random_bytes_secure(AES128_GCM_IV_LENGTH, GCRY_VERY_STRONG_RANDOM);
res = aes128gcm_encrypt(ciphertext, &ciphertext_len, tag, &tag_len, (const unsigned char* const)message, strlen(message), iv, key);
if (res != 0) {
log_error("[OMEMO][SEND] cannot encrypt message");
goto out;
}
memcpy(key_tag, key, AES128_GCM_KEY_LENGTH);
memcpy(key_tag + AES128_GCM_KEY_LENGTH, tag, AES128_GCM_TAG_LENGTH);
// List of barejids of the recipients of this message
GList* recipients = NULL;
if (muc) {
ProfMucWin* mucwin = (ProfMucWin*)win;
assert(mucwin->memcheck == PROFMUCWIN_MEMCHECK);
GList* members = muc_members(mucwin->roomjid);
GList* iter;
for (iter = members; iter != NULL; iter = iter->next) {
Jid* jid = jid_create(iter->data);
recipients = g_list_append(recipients, strdup(jid->barejid));
jid_destroy(jid);
}
g_list_free(members);
} else {
ProfChatWin* chatwin = (ProfChatWin*)win;
assert(chatwin->memcheck == PROFCHATWIN_MEMCHECK);
recipients = g_list_append(recipients, strdup(chatwin->barejid));
}
GList* device_ids_iter;
omemo_ctx.identity_key_store.recv = false;
// Encrypt keys for the recipients
GList* recipients_iter;
for (recipients_iter = recipients; recipients_iter != NULL; recipients_iter = recipients_iter->next) {
GList* recipient_device_id = NULL;
recipient_device_id = g_hash_table_lookup(omemo_ctx.device_list, recipients_iter->data);
if (!recipient_device_id) {
log_warning("[OMEMO][SEND] cannot find device ids for %s", recipients_iter->data);
win_println(win, THEME_ERROR, "!", "Can't find a OMEMO device id for %s.\n", recipients_iter->data);
continue;
}
for (device_ids_iter = recipient_device_id; device_ids_iter != NULL; device_ids_iter = device_ids_iter->next) {
int res;
ciphertext_message* ciphertext;
session_cipher* cipher;
signal_protocol_address address = {
.name = recipients_iter->data,
.name_len = strlen(recipients_iter->data),
.device_id = GPOINTER_TO_INT(device_ids_iter->data)
};
// Don't encrypt for this device (according to
// <https://xmpp.org/extensions/xep-0384.html#encrypt>).
// Yourself as recipients in case of MUC
char* mybarejid = connection_get_barejid();
if (!g_strcmp0(mybarejid, recipients_iter->data)) {
if (GPOINTER_TO_INT(device_ids_iter->data) == omemo_ctx.device_id) {
free(mybarejid);
log_debug("[OMEMO][SEND] Skipping %d (my device) ", GPOINTER_TO_INT(device_ids_iter->data));
continue;
}
}
free(mybarejid);
log_debug("[OMEMO][SEND] recipients with device id %d for %s", GPOINTER_TO_INT(device_ids_iter->data), recipients_iter->data);
res = session_cipher_create(&cipher, omemo_ctx.store, &address, omemo_ctx.signal);
if (res != SG_SUCCESS) {
log_error("[OMEMO][SEND] cannot create cipher for %s device id %d - code: %d", address.name, address.device_id, res);
continue;
}
res = session_cipher_encrypt(cipher, key_tag, AES128_GCM_KEY_LENGTH + AES128_GCM_TAG_LENGTH, &ciphertext);
session_cipher_free(cipher);
if (res != SG_SUCCESS) {
log_info("[OMEMO][SEND] cannot encrypt key for %s device id %d - code: %d", address.name, address.device_id, res);
continue;
}
signal_buffer* buffer = ciphertext_message_get_serialized(ciphertext);
omemo_key_t* key = malloc(sizeof(omemo_key_t));
key->length = signal_buffer_len(buffer);
key->data = malloc(key->length);
memcpy(key->data, signal_buffer_data(buffer), key->length);
key->device_id = GPOINTER_TO_INT(device_ids_iter->data);
key->prekey = ciphertext_message_get_type(ciphertext) == CIPHERTEXT_PREKEY_TYPE;
keys = g_list_append(keys, key);
SIGNAL_UNREF(ciphertext);
}
}
g_list_free_full(recipients, free);
// Don't send the message if no key could be encrypted.
// (Since none of the recipients would be able to read the message.)
if (keys == NULL) {
win_println(win, THEME_ERROR, "!", "This message cannot be decrypted for any recipient.\n"
"You should trust your recipients' device fingerprint(s) using \"/omemo fingerprint trust FINGERPRINT\".\n"
"It could also be that the key bundle of the recipient(s) have not been received. "
"In this case, you could try \"omemo end\", \"omemo start\", and send the message again.");
goto out;
}
// Encrypt keys for the sender
if (!muc) {
GList* sender_device_id = g_hash_table_lookup(omemo_ctx.device_list, jid->barejid);
for (device_ids_iter = sender_device_id; device_ids_iter != NULL; device_ids_iter = device_ids_iter->next) {
int res;
ciphertext_message* ciphertext;
session_cipher* cipher;
signal_protocol_address address = {
.name = jid->barejid,
.name_len = strlen(jid->barejid),
.device_id = GPOINTER_TO_INT(device_ids_iter->data)
};
log_debug("[OMEMO][SEND][Sender] Sending to device %d for %s ", address.device_id, address.name);
// Don't encrypt for this device (according to
// <https://xmpp.org/extensions/xep-0384.html#encrypt>).
if (address.device_id == omemo_ctx.device_id) {
continue;
}
res = session_cipher_create(&cipher, omemo_ctx.store, &address, omemo_ctx.signal);
if (res != 0) {
log_info("[OMEMO][SEND][Sender] cannot create cipher for %s device id %d", address.name, address.device_id);
continue;
}
res = session_cipher_encrypt(cipher, key_tag, AES128_GCM_KEY_LENGTH + AES128_GCM_TAG_LENGTH, &ciphertext);
session_cipher_free(cipher);
if (res != 0) {
log_info("[OMEMO][SEND][Sender] cannot encrypt key for %s device id %d", address.name, address.device_id);
continue;
}
signal_buffer* buffer = ciphertext_message_get_serialized(ciphertext);
omemo_key_t* key = malloc(sizeof(omemo_key_t));
key->length = signal_buffer_len(buffer);
key->data = malloc(key->length);
memcpy(key->data, signal_buffer_data(buffer), key->length);
key->device_id = GPOINTER_TO_INT(device_ids_iter->data);
key->prekey = ciphertext_message_get_type(ciphertext) == CIPHERTEXT_PREKEY_TYPE;
keys = g_list_append(keys, key);
SIGNAL_UNREF(ciphertext);
}
}
// Send the message
if (muc) {
ProfMucWin* mucwin = (ProfMucWin*)win;
assert(mucwin->memcheck == PROFMUCWIN_MEMCHECK);
id = message_send_chat_omemo(mucwin->roomjid, omemo_ctx.device_id, keys, iv, AES128_GCM_IV_LENGTH, ciphertext, ciphertext_len, request_receipt, TRUE, replace_id);
} else {
ProfChatWin* chatwin = (ProfChatWin*)win;
assert(chatwin->memcheck == PROFCHATWIN_MEMCHECK);
id = message_send_chat_omemo(chatwin->barejid, omemo_ctx.device_id, keys, iv, AES128_GCM_IV_LENGTH, ciphertext, ciphertext_len, request_receipt, FALSE, replace_id);
}
out:
jid_destroy(jid);
g_list_free_full(keys, (GDestroyNotify)omemo_key_free);
free(ciphertext);
gcry_free(key);
gcry_free(iv);
gcry_free(tag);
gcry_free(key_tag);
return id;
}
char*
omemo_on_message_recv(const char* const from_jid, uint32_t sid,
const unsigned char* const iv, size_t iv_len, GList* keys,
const unsigned char* const payload, size_t payload_len, gboolean muc, gboolean* trusted)
{
unsigned char* plaintext = NULL;
Jid* sender = NULL;
Jid* from = jid_create(from_jid);
if (!from) {
log_error("[OMEMO][RECV] Invalid jid %s", from_jid);
goto out;
}
int res;
GList* key_iter;
omemo_key_t* key = NULL;
for (key_iter = keys; key_iter != NULL; key_iter = key_iter->next) {
if (((omemo_key_t*)key_iter->data)->device_id == omemo_ctx.device_id) {
key = key_iter->data;
break;
}
}
if (!key) {
log_warning("[OMEMO][RECV] received a message with no corresponding key");
goto out;
}
if (muc) {
GList* roster = muc_roster(from->barejid);
GList* iter;
for (iter = roster; iter != NULL; iter = iter->next) {
Occupant* occupant = (Occupant*)iter->data;
if (g_strcmp0(occupant->nick, from->resourcepart) == 0) {
sender = jid_create(occupant->jid);
break;
}
}
g_list_free(roster);
if (!sender) {
log_warning("[OMEMO][RECV] cannot find MUC message sender fulljid");
goto out;
}
} else {
sender = jid_create(from->barejid);
}
session_cipher* cipher;
signal_buffer* plaintext_key;
signal_protocol_address address = {
.name = sender->barejid,
.name_len = strlen(sender->barejid),
.device_id = sid
};
res = session_cipher_create(&cipher, omemo_ctx.store, &address, omemo_ctx.signal);
if (res != 0) {
log_error("[OMEMO][RECV] cannot create session cipher");
goto out;
}
if (key->prekey) {
log_debug("[OMEMO][RECV] decrypting message with prekey");
pre_key_signal_message* message;
ec_public_key* their_identity_key;
signal_buffer* identity_buffer = NULL;
omemo_ctx.identity_key_store.recv = true;
pre_key_signal_message_deserialize(&message, key->data, key->length, omemo_ctx.signal);
their_identity_key = pre_key_signal_message_get_identity_key(message);
res = session_cipher_decrypt_pre_key_signal_message(cipher, message, NULL, &plaintext_key);
omemo_ctx.identity_key_store.recv = false;
/* Perform a real check of the identity */
ec_public_key_serialize(&identity_buffer, their_identity_key);
*trusted = is_trusted_identity(&address, signal_buffer_data(identity_buffer),
signal_buffer_len(identity_buffer), &omemo_ctx.identity_key_store);
/* Replace used pre_key in bundle */
uint32_t pre_key_id = pre_key_signal_message_get_pre_key_id(message);
ec_key_pair* ec_pair;
session_pre_key* new_pre_key;
curve_generate_key_pair(omemo_ctx.signal, &ec_pair);
session_pre_key_create(&new_pre_key, pre_key_id, ec_pair);
signal_protocol_pre_key_store_key(omemo_ctx.store, new_pre_key);
SIGNAL_UNREF(new_pre_key);
SIGNAL_UNREF(message);
SIGNAL_UNREF(ec_pair);
omemo_bundle_publish(true);
if (res == 0) {
/* Start a new session */
log_debug("[OMEMO][RECV] Res is 0 => omemo_bundle_request");
omemo_bundle_request(sender->barejid, sid, omemo_start_device_session_handle_bundle, free, strdup(sender->barejid));
}
} else {
log_debug("[OMEMO][RECV] decrypting message with existing session");
signal_message* message = NULL;
res = signal_message_deserialize(&message, key->data, key->length, omemo_ctx.signal);
if (res < 0) {
log_error("[OMEMO][RECV] cannot deserialize message");
} else {
res = session_cipher_decrypt_signal_message(cipher, message, NULL, &plaintext_key);
*trusted = true;
SIGNAL_UNREF(message);
}
}
session_cipher_free(cipher);
if (res != 0) {
log_error("[OMEMO][RECV] cannot decrypt message key");
goto out;
}
if (signal_buffer_len(plaintext_key) != AES128_GCM_KEY_LENGTH + AES128_GCM_TAG_LENGTH) {
log_error("[OMEMO][RECV] invalid key length");
signal_buffer_free(plaintext_key);
goto out;
}
size_t plaintext_len = payload_len;
plaintext = malloc(plaintext_len + 1);
res = aes128gcm_decrypt(plaintext, &plaintext_len, payload, payload_len, iv,
iv_len, signal_buffer_data(plaintext_key),
signal_buffer_data(plaintext_key) + AES128_GCM_KEY_LENGTH);
signal_buffer_free(plaintext_key);
if (res != 0) {
log_error("[OMEMO][RECV] cannot decrypt message: %s", gcry_strerror(res));
free(plaintext);
plaintext = NULL;
goto out;
}
plaintext[plaintext_len] = '\0';
out:
jid_destroy(from);
jid_destroy(sender);
return (char*)plaintext;
}
char*
omemo_format_fingerprint(const char* const fingerprint)
{
char* output = malloc(strlen(fingerprint) + strlen(fingerprint) / 8);
int i, j;
for (i = 0, j = 0; i < strlen(fingerprint); i++) {
if (i > 0 && i % 8 == 0) {
output[j++] = '-';
}
output[j++] = fingerprint[i];
}
output[j] = '\0';
return output;
}
static char*
_omemo_unformat_fingerprint(const char* const fingerprint_formatted)
{
/* Unformat fingerprint */
char* fingerprint = malloc(strlen(fingerprint_formatted));
int i;
int j;
for (i = 0, j = 0; fingerprint_formatted[i] != '\0'; i++) {
if (!g_ascii_isxdigit(fingerprint_formatted[i])) {
continue;
}
fingerprint[j++] = fingerprint_formatted[i];
}
fingerprint[j] = '\0';
return fingerprint;
}
char*
omemo_own_fingerprint(gboolean formatted)
{
ec_public_key* identity = ratchet_identity_key_pair_get_public(omemo_ctx.identity_key_pair);
return _omemo_fingerprint(identity, formatted);
}
GList*
omemo_known_device_identities(const char* const jid)
{
GHashTable* known_identities = g_hash_table_lookup(omemo_ctx.known_devices, jid);
if (!known_identities) {
return NULL;
}
return g_hash_table_get_keys(known_identities);
}
gboolean
omemo_is_trusted_identity(const char* const jid, const char* const fingerprint)
{
GHashTable* known_identities = g_hash_table_lookup(omemo_ctx.known_devices, jid);
if (!known_identities) {
return FALSE;
}
void* device_id = g_hash_table_lookup(known_identities, fingerprint);
if (!device_id) {
return FALSE;
}
signal_protocol_address address = {
.name = jid,
.name_len = strlen(jid),
.device_id = GPOINTER_TO_INT(device_id),
};
size_t fingerprint_len;
unsigned char* fingerprint_raw = _omemo_fingerprint_decode(fingerprint, &fingerprint_len);
unsigned char djb_type[] = { '\x05' };
signal_buffer* buffer = signal_buffer_create(djb_type, 1);
buffer = signal_buffer_append(buffer, fingerprint_raw, fingerprint_len);
gboolean trusted = is_trusted_identity(&address, signal_buffer_data(buffer), signal_buffer_len(buffer), &omemo_ctx.identity_key_store);
log_debug("[OMEMO] Device trusted %s (%d): %d", jid, GPOINTER_TO_INT(device_id), trusted);
free(fingerprint_raw);
signal_buffer_free(buffer);
return trusted;
}
static char*
_omemo_fingerprint(ec_public_key* identity, gboolean formatted)
{
int i;
signal_buffer* identity_public_key;
ec_public_key_serialize(&identity_public_key, identity);
size_t identity_public_key_len = signal_buffer_len(identity_public_key);
unsigned char* identity_public_key_data = signal_buffer_data(identity_public_key);
/* Skip first byte corresponding to signal DJB_TYPE */
identity_public_key_len--;
identity_public_key_data = &identity_public_key_data[1];
char* fingerprint = malloc(identity_public_key_len * 2 + 1);
for (i = 0; i < identity_public_key_len; i++) {
fingerprint[i * 2] = (identity_public_key_data[i] & 0xf0) >> 4;
fingerprint[i * 2] += '0';
if (fingerprint[i * 2] > '9') {
fingerprint[i * 2] += 0x27;
}
fingerprint[(i * 2) + 1] = identity_public_key_data[i] & 0x0f;
fingerprint[(i * 2) + 1] += '0';
if (fingerprint[(i * 2) + 1] > '9') {
fingerprint[(i * 2) + 1] += 0x27;
}
}
fingerprint[i * 2] = '\0';
signal_buffer_free(identity_public_key);
if (!formatted) {
return fingerprint;
} else {
char* formatted_fingerprint = omemo_format_fingerprint(fingerprint);
free(fingerprint);
return formatted_fingerprint;
}
}
static unsigned char*
_omemo_fingerprint_decode(const char* const fingerprint, size_t* len)
{
unsigned char* output = malloc(strlen(fingerprint) / 2 + 1);
int i;
int j;
for (i = 0, j = 0; i < strlen(fingerprint);) {
if (!g_ascii_isxdigit(fingerprint[i])) {
i++;
continue;
}
output[j] = g_ascii_xdigit_value(fingerprint[i++]) << 4;
output[j] |= g_ascii_xdigit_value(fingerprint[i++]);
j++;
}
*len = j;
return output;
}
void
omemo_trust(const char* const jid, const char* const fingerprint_formatted)
{
size_t len;
GHashTable* known_identities = g_hash_table_lookup(omemo_ctx.known_devices, jid);
if (!known_identities) {
log_warning("[OMEMO] cannot trust unknown device: %s", fingerprint_formatted);
cons_show("Cannot trust unknown device: %s", fingerprint_formatted);
return;
}
char* fingerprint = _omemo_unformat_fingerprint(fingerprint_formatted);
uint32_t device_id = GPOINTER_TO_INT(g_hash_table_lookup(known_identities, fingerprint));
free(fingerprint);
if (!device_id) {
log_warning("[OMEMO] cannot trust unknown device: %s", fingerprint_formatted);
cons_show("Cannot trust unknown device: %s", fingerprint_formatted);
return;
}
/* TODO should not hardcode DJB_TYPE here
* should instead store identity key in known_identities along with
* device_id */
signal_protocol_address address = {
.name = jid,
.name_len = strlen(jid),
.device_id = device_id,
};
unsigned char* fingerprint_raw = _omemo_fingerprint_decode(fingerprint_formatted, &len);
unsigned char djb_type[] = { '\x05' };
signal_buffer* buffer = signal_buffer_create(djb_type, 1);
buffer = signal_buffer_append(buffer, fingerprint_raw, len);
save_identity(&address, signal_buffer_data(buffer), signal_buffer_len(buffer), &omemo_ctx.identity_key_store);
free(fingerprint_raw);
signal_buffer_free(buffer);
omemo_bundle_request(jid, device_id, omemo_start_device_session_handle_bundle, free, strdup(jid));
}
void
omemo_untrust(const char* const jid, const char* const fingerprint_formatted)
{
size_t len;
unsigned char* identity = _omemo_fingerprint_decode(fingerprint_formatted, &len);
GHashTableIter iter;
gpointer key, value;
GHashTable* trusted = g_hash_table_lookup(omemo_ctx.identity_key_store.trusted, jid);
if (!trusted) {
free(identity);
return;
}
g_hash_table_iter_init(&iter, trusted);
while (g_hash_table_iter_next(&iter, &key, &value)) {
signal_buffer* buffer = value;
unsigned char* original = signal_buffer_data(buffer);
/* Skip DJB_TYPE byte */
original++;
if ((signal_buffer_len(buffer) - 1) == len && memcmp(original, identity, len) == 0) {
g_hash_table_remove(trusted, key);
}
}
free(identity);
char* fingerprint = _omemo_unformat_fingerprint(fingerprint_formatted);
/* Remove existing session */
GHashTable* known_identities = g_hash_table_lookup(omemo_ctx.known_devices, jid);
if (!known_identities) {
log_error("[OMEMO] cannot find known device while untrusting a fingerprint");
goto out;
}
uint32_t device_id = GPOINTER_TO_INT(g_hash_table_lookup(known_identities, fingerprint));
if (!device_id) {
log_error("[OMEMO] cannot find device id while untrusting a fingerprint");
goto out;
}
signal_protocol_address address = {
.name = jid,
.name_len = strlen(jid),
.device_id = device_id
};
delete_session(&address, omemo_ctx.session_store);
/* Remove from keyfile */
char* device_id_str = g_strdup_printf("%d", device_id);
g_key_file_remove_key(omemo_ctx.trust_keyfile, jid, device_id_str, NULL);
g_free(device_id_str);
omemo_trust_keyfile_save();
out:
free(fingerprint);
}
static void
_lock(void* user_data)
{
omemo_context* ctx = (omemo_context*)user_data;
pthread_mutex_lock(&ctx->lock);
}
static void
_unlock(void* user_data)
{
omemo_context* ctx = (omemo_context*)user_data;
pthread_mutex_unlock(&ctx->lock);
}
static void
_omemo_log(int level, const char* message, size_t len, void* user_data)
{
switch (level) {
case SG_LOG_ERROR:
log_error("[OMEMO][SIGNAL] %s", message);
break;
case SG_LOG_WARNING:
log_warning("[OMEMO][SIGNAL] %s", message);
break;
case SG_LOG_NOTICE:
case SG_LOG_INFO:
log_debug("[OMEMO][SIGNAL] %s", message);
break;
case SG_LOG_DEBUG:
log_debug("[OMEMO][SIGNAL] %s", message);
break;
}
}
static gboolean
_handle_own_device_list(const char* const jid, GList* device_list)
{
// We didn't find the own device id -> publish
if (!g_list_find(device_list, GINT_TO_POINTER(omemo_ctx.device_id))) {
cons_show("Could not find own OMEMO device ID. Going to publish own device ID: %d", GINT_TO_POINTER(omemo_ctx.device_id));
log_debug("[OMEMO] No device ID for our device. Publishing device list");
device_list = g_list_copy(device_list);
device_list = g_list_append(device_list, GINT_TO_POINTER(omemo_ctx.device_id));
g_hash_table_insert(omemo_ctx.device_list, strdup(jid), device_list);
omemo_devicelist_publish(device_list);
}
log_debug("[OMEMO] Request OMEMO Bundles for our devices");
GList* device_id;
for (device_id = device_list; device_id != NULL; device_id = device_id->next) {
omemo_bundle_request(jid, GPOINTER_TO_INT(device_id->data), omemo_start_device_session_handle_bundle, free, strdup(jid));
}
return TRUE;
}
static gboolean
_handle_device_list_start_session(const char* const jid, GList* device_list)
{
log_debug("[OMEMO] Start session for %s - device_list", jid);
omemo_start_session(jid);
return FALSE;
}
void
omemo_key_free(omemo_key_t* key)
{
if (key == NULL) {
return;
}
free(key->data);
free(key);
}
char*
omemo_fingerprint_autocomplete(const char* const search_str, gboolean previous, void* context)
{
Autocomplete ac = g_hash_table_lookup(omemo_ctx.fingerprint_ac, context);
if (ac != NULL) {
return autocomplete_complete(ac, search_str, FALSE, previous);
} else {
return NULL;
}
}
void
omemo_fingerprint_autocomplete_reset(void)
{
gpointer value;
GHashTableIter iter;
g_hash_table_iter_init(&iter, omemo_ctx.fingerprint_ac);
while (g_hash_table_iter_next(&iter, NULL, &value)) {
Autocomplete ac = value;
autocomplete_reset(ac);
}
}
gboolean
omemo_automatic_start(const char* const recipient)
{
gboolean result = FALSE;
char* account_name = session_get_account_name();
ProfAccount* account = accounts_get_account(account_name);
prof_omemopolicy_t policy;
if (account->omemo_policy) {
// check default account setting
if (g_strcmp0(account->omemo_policy, "manual") == 0) {
policy = PROF_OMEMOPOLICY_MANUAL;
}
if (g_strcmp0(account->omemo_policy, "opportunistic") == 0) {
policy = PROF_OMEMOPOLICY_AUTOMATIC;
}
if (g_strcmp0(account->omemo_policy, "always") == 0) {
policy = PROF_OMEMOPOLICY_ALWAYS;
}
} else {
// check global setting
char* pref_omemo_policy = prefs_get_string(PREF_OMEMO_POLICY);
// pref defaults to manual
policy = PROF_OMEMOPOLICY_AUTOMATIC;
if (strcmp(pref_omemo_policy, "manual") == 0) {
policy = PROF_OMEMOPOLICY_MANUAL;
} else if (strcmp(pref_omemo_policy, "always") == 0) {
policy = PROF_OMEMOPOLICY_ALWAYS;
}
g_free(pref_omemo_policy);
}
switch (policy) {
case PROF_OMEMOPOLICY_MANUAL:
result = FALSE;
break;
case PROF_OMEMOPOLICY_AUTOMATIC:
if (g_list_find_custom(account->omemo_enabled, recipient, (GCompareFunc)g_strcmp0)) {
result = TRUE;
} else if (g_list_find_custom(account->omemo_disabled, recipient, (GCompareFunc)g_strcmp0)) {
result = FALSE;
} else {
result = FALSE;
}
break;
case PROF_OMEMOPOLICY_ALWAYS:
if (g_list_find_custom(account->omemo_disabled, recipient, (GCompareFunc)g_strcmp0)) {
result = FALSE;
} else {
result = TRUE;
}
break;
}
account_free(account);
return result;
}
static gboolean
_load_identity(void)
{
GError* error = NULL;
log_info("[OMEMO] Loading OMEMO identity");
/* Device ID */
error = NULL;
omemo_ctx.device_id = g_key_file_get_uint64(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_IDENTITY, OMEMO_STORE_KEY_DEVICE_ID, &error);
if (error != NULL) {
log_error("[OMEMO] cannot load device id: %s", error->message);
return FALSE;
}
log_debug("[OMEMO] device id: %d", omemo_ctx.device_id);
/* Registration ID */
error = NULL;
omemo_ctx.registration_id = g_key_file_get_uint64(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_IDENTITY, OMEMO_STORE_KEY_REGISTRATION_ID, &error);
if (error != NULL) {
log_error("[OMEMO] cannot load registration id: %s", error->message);
return FALSE;
}
/* Identity key */
error = NULL;
char* identity_key_public_b64 = g_key_file_get_string(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_IDENTITY, OMEMO_STORE_KEY_IDENTITY_KEY_PUBLIC, &error);
if (!identity_key_public_b64) {
log_error("[OMEMO] cannot load identity public key: %s", error->message);
return FALSE;
}
size_t identity_key_public_len;
unsigned char* identity_key_public = g_base64_decode(identity_key_public_b64, &identity_key_public_len);
g_free(identity_key_public_b64);
omemo_ctx.identity_key_store.public = signal_buffer_create(identity_key_public, identity_key_public_len);
error = NULL;
char* identity_key_private_b64 = g_key_file_get_string(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_IDENTITY, OMEMO_STORE_KEY_IDENTITY_KEY_PRIVATE, &error);
if (!identity_key_private_b64) {
log_error("[OMEMO] cannot load identity private key: %s", error->message);
return FALSE;
}
size_t identity_key_private_len;
unsigned char* identity_key_private = g_base64_decode(identity_key_private_b64, &identity_key_private_len);
g_free(identity_key_private_b64);
omemo_ctx.identity_key_store.private = signal_buffer_create(identity_key_private, identity_key_private_len);
ec_public_key* public_key;
curve_decode_point(&public_key, identity_key_public, identity_key_public_len, omemo_ctx.signal);
ec_private_key* private_key;
curve_decode_private_point(&private_key, identity_key_private, identity_key_private_len, omemo_ctx.signal);
ratchet_identity_key_pair_create(&omemo_ctx.identity_key_pair, public_key, private_key);
g_free(identity_key_public);
g_free(identity_key_private);
char** keys = NULL;
int i;
/* Pre keys */
i = 0;
keys = g_key_file_get_keys(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_PREKEYS, NULL, NULL);
if (keys) {
for (i = 0; keys[i] != NULL; i++) {
char* pre_key_b64 = g_key_file_get_string(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_PREKEYS, keys[i], NULL);
size_t pre_key_len;
unsigned char* pre_key = g_base64_decode(pre_key_b64, &pre_key_len);
g_free(pre_key_b64);
signal_buffer* buffer = signal_buffer_create(pre_key, pre_key_len);
g_free(pre_key);
g_hash_table_insert(omemo_ctx.pre_key_store, GINT_TO_POINTER(strtoul(keys[i], NULL, 10)), buffer);
}
g_strfreev(keys);
}
/* Ensure we have at least 100 pre keys */
if (i < 100) {
_generate_pre_keys(100 - i);
}
/* Signed pre keys */
i = 0;
keys = g_key_file_get_keys(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_SIGNED_PREKEYS, NULL, NULL);
if (keys) {
for (i = 0; keys[i] != NULL; i++) {
char* signed_pre_key_b64 = g_key_file_get_string(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_SIGNED_PREKEYS, keys[i], NULL);
size_t signed_pre_key_len;
unsigned char* signed_pre_key = g_base64_decode(signed_pre_key_b64, &signed_pre_key_len);
g_free(signed_pre_key_b64);
signal_buffer* buffer = signal_buffer_create(signed_pre_key, signed_pre_key_len);
g_free(signed_pre_key);
g_hash_table_insert(omemo_ctx.signed_pre_key_store, GINT_TO_POINTER(strtoul(keys[i], NULL, 10)), buffer);
omemo_ctx.signed_pre_key_id = strtoul(keys[i], NULL, 10);
}
g_strfreev(keys);
}
if (i == 0) {
_generate_signed_pre_key();
}
loaded = TRUE;
omemo_identity_keyfile_save();
omemo_start_sessions();
return TRUE;
}
static void
_load_trust(void)
{
char** keys = NULL;
char** groups = g_key_file_get_groups(omemo_ctx.trust_keyfile, NULL);
if (groups) {
int i;
for (i = 0; groups[i] != NULL; i++) {
GHashTable* trusted;
trusted = g_hash_table_lookup(omemo_ctx.identity_key_store.trusted, groups[i]);
if (!trusted) {
trusted = g_hash_table_new_full(g_direct_hash, g_direct_equal, NULL, (GDestroyNotify)signal_buffer_free);
g_hash_table_insert(omemo_ctx.identity_key_store.trusted, strdup(groups[i]), trusted);
}
keys = g_key_file_get_keys(omemo_ctx.trust_keyfile, groups[i], NULL, NULL);
int j;
for (j = 0; keys[j] != NULL; j++) {
char* key_b64 = g_key_file_get_string(omemo_ctx.trust_keyfile, groups[i], keys[j], NULL);
size_t key_len;
unsigned char* key = g_base64_decode(key_b64, &key_len);
g_free(key_b64);
signal_buffer* buffer = signal_buffer_create(key, key_len);
g_free(key);
uint32_t device_id = strtoul(keys[j], NULL, 10);
g_hash_table_insert(trusted, GINT_TO_POINTER(device_id), buffer);
}
g_strfreev(keys);
}
g_strfreev(groups);
}
}
static void
_load_sessions(void)
{
int i;
char** groups = g_key_file_get_groups(omemo_ctx.sessions_keyfile, NULL);
if (groups) {
for (i = 0; groups[i] != NULL; i++) {
int j;
GHashTable* device_store = NULL;
device_store = g_hash_table_lookup(omemo_ctx.session_store, groups[i]);
if (!device_store) {
device_store = g_hash_table_new_full(g_direct_hash, g_direct_equal, NULL, (GDestroyNotify)signal_buffer_free);
g_hash_table_insert(omemo_ctx.session_store, strdup(groups[i]), device_store);
}
char** keys = g_key_file_get_keys(omemo_ctx.sessions_keyfile, groups[i], NULL, NULL);
for (j = 0; keys[j] != NULL; j++) {
uint32_t id = strtoul(keys[j], NULL, 10);
char* record_b64 = g_key_file_get_string(omemo_ctx.sessions_keyfile, groups[i], keys[j], NULL);
size_t record_len;
unsigned char* record = g_base64_decode(record_b64, &record_len);
g_free(record_b64);
signal_buffer* buffer = signal_buffer_create(record, record_len);
g_free(record);
g_hash_table_insert(device_store, GINT_TO_POINTER(id), buffer);
}
g_strfreev(keys);
}
g_strfreev(groups);
}
}
static void
_load_known_devices(void)
{
int i;
char** groups = g_key_file_get_groups(omemo_ctx.known_devices_keyfile, NULL);
if (groups) {
for (i = 0; groups[i] != NULL; i++) {
int j;
GHashTable* known_identities = NULL;
known_identities = g_hash_table_lookup(omemo_ctx.known_devices, groups[i]);
if (!known_identities) {
known_identities = g_hash_table_new_full(g_str_hash, g_str_equal, free, NULL);
g_hash_table_insert(omemo_ctx.known_devices, strdup(groups[i]), known_identities);
}
char** keys = g_key_file_get_keys(omemo_ctx.known_devices_keyfile, groups[i], NULL, NULL);
for (j = 0; keys[j] != NULL; j++) {
uint32_t device_id = strtoul(keys[j], NULL, 10);
char* fingerprint = g_key_file_get_string(omemo_ctx.known_devices_keyfile, groups[i], keys[j], NULL);
g_hash_table_insert(known_identities, strdup(fingerprint), GINT_TO_POINTER(device_id));
g_free(fingerprint);
}
g_strfreev(keys);
}
g_strfreev(groups);
}
}
static void
_cache_device_identity(const char* const jid, uint32_t device_id, ec_public_key* identity)
{
GHashTable* known_identities = g_hash_table_lookup(omemo_ctx.known_devices, jid);
if (!known_identities) {
known_identities = g_hash_table_new_full(g_str_hash, g_str_equal, free, NULL);
g_hash_table_insert(omemo_ctx.known_devices, strdup(jid), known_identities);
}
char* fingerprint = _omemo_fingerprint(identity, FALSE);
log_debug("[OMEMO] cache identity for %s:%d: %s", jid, device_id, fingerprint);
g_hash_table_insert(known_identities, strdup(fingerprint), GINT_TO_POINTER(device_id));
char* device_id_str = g_strdup_printf("%d", device_id);
g_key_file_set_string(omemo_ctx.known_devices_keyfile, jid, device_id_str, fingerprint);
g_free(device_id_str);
omemo_known_devices_keyfile_save();
Autocomplete ac = g_hash_table_lookup(omemo_ctx.fingerprint_ac, jid);
if (ac == NULL) {
ac = autocomplete_new();
g_hash_table_insert(omemo_ctx.fingerprint_ac, strdup(jid), ac);
}
char* formatted_fingerprint = omemo_format_fingerprint(fingerprint);
autocomplete_add(ac, formatted_fingerprint);
free(formatted_fingerprint);
free(fingerprint);
}
static void
_g_hash_table_free(GHashTable* hash_table)
{
g_hash_table_remove_all(hash_table);
g_hash_table_unref(hash_table);
}
static void
_generate_pre_keys(int count)
{
unsigned int start;
gcry_randomize(&start, sizeof(unsigned int), GCRY_VERY_STRONG_RANDOM);
signal_protocol_key_helper_pre_key_list_node* pre_keys_head;
signal_protocol_key_helper_generate_pre_keys(&pre_keys_head, start, count, omemo_ctx.signal);
signal_protocol_key_helper_pre_key_list_node* p;
for (p = pre_keys_head; p != NULL; p = signal_protocol_key_helper_key_list_next(p)) {
session_pre_key* prekey = signal_protocol_key_helper_key_list_element(p);
signal_protocol_pre_key_store_key(omemo_ctx.store, prekey);
}
signal_protocol_key_helper_key_list_free(pre_keys_head);
}
static void
_generate_signed_pre_key(void)
{
session_signed_pre_key* signed_pre_key;
struct timeval tv;
gettimeofday(&tv, NULL);
unsigned long long timestamp = (unsigned long long)(tv.tv_sec) * 1000 + (unsigned long long)(tv.tv_usec) / 1000;
omemo_ctx.signed_pre_key_id = 1;
signal_protocol_key_helper_generate_signed_pre_key(&signed_pre_key, omemo_ctx.identity_key_pair, omemo_ctx.signed_pre_key_id, timestamp, omemo_ctx.signal);
signal_protocol_signed_pre_key_store_key(omemo_ctx.store, signed_pre_key);
SIGNAL_UNREF(signed_pre_key);
}
void
omemo_free(void* a)
{
gcry_free(a);
}
char*
omemo_encrypt_file(FILE* in, FILE* out, off_t file_size, int* gcry_res)
{
unsigned char* key = gcry_random_bytes_secure(
OMEMO_AESGCM_KEY_LENGTH,
GCRY_VERY_STRONG_RANDOM);
// Create nonce/IV with random bytes.
unsigned char nonce[OMEMO_AESGCM_NONCE_LENGTH];
gcry_create_nonce(nonce, OMEMO_AESGCM_NONCE_LENGTH);
char* fragment = aes256gcm_create_secure_fragment(key, nonce);
*gcry_res = aes256gcm_crypt_file(in, out, file_size, key, nonce, true);
if (*gcry_res != GPG_ERR_NO_ERROR) {
gcry_free(fragment);
fragment = NULL;
}
gcry_free(key);
return fragment;
}
void
_bytes_from_hex(const char* hex, size_t hex_size,
unsigned char* bytes, size_t bytes_size)
{
const unsigned char ht[] = {
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, // 01234567
0x08, 0x09, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 89:;<=>?
0x00, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x00, // @ABCDEFG
};
const size_t ht_size = sizeof(ht);
unsigned char b0;
unsigned char b1;
memset(bytes, 0, bytes_size);
for (int i = 0; (i < hex_size) && (i / 2 < bytes_size); i += 2) {
b0 = ((unsigned char)hex[i + 0] & 0x1f) ^ 0x10;
b1 = ((unsigned char)hex[i + 1] & 0x1f) ^ 0x10;
if (b0 <= ht_size && b1 <= ht_size) {
bytes[i / 2] = (unsigned char)(ht[b0] << 4) | ht[b1];
}
}
}
gcry_error_t
omemo_decrypt_file(FILE* in, FILE* out, off_t file_size, const char* fragment)
{
char nonce_hex[AESGCM_URL_NONCE_LEN];
char key_hex[AESGCM_URL_KEY_LEN];
const int nonce_pos = 0;
const int key_pos = AESGCM_URL_NONCE_LEN;
memcpy(nonce_hex, &(fragment[nonce_pos]), AESGCM_URL_NONCE_LEN);
memcpy(key_hex, &(fragment[key_pos]), AESGCM_URL_KEY_LEN);
unsigned char nonce[OMEMO_AESGCM_NONCE_LENGTH];
unsigned char* key = gcry_malloc_secure(OMEMO_AESGCM_KEY_LENGTH);
_bytes_from_hex(nonce_hex, AESGCM_URL_NONCE_LEN,
nonce, OMEMO_AESGCM_NONCE_LENGTH);
_bytes_from_hex(key_hex, AESGCM_URL_KEY_LEN,
key, OMEMO_AESGCM_KEY_LENGTH);
gcry_error_t crypt_res;
crypt_res = aes256gcm_crypt_file(in, out, file_size, key, nonce, false);
gcry_free(key);
return crypt_res;
}
int
omemo_parse_aesgcm_url(const char* aesgcm_url,
char** https_url,
char** fragment)
{
CURLUcode ret;
CURLU* url = curl_url();
// Required to allow for the "aesgcm://" scheme that OMEMO Media Sharing
// uses.
unsigned int curl_flags = CURLU_NON_SUPPORT_SCHEME;
ret = curl_url_set(url, CURLUPART_URL, aesgcm_url, curl_flags);
if (ret) {
goto out;
}
ret = curl_url_get(url, CURLUPART_FRAGMENT, fragment, curl_flags);
if (ret) {
goto out;
}
if (strlen(*fragment) != AESGCM_URL_NONCE_LEN + AESGCM_URL_KEY_LEN) {
ret = 1;
goto out;
}
// Clear fragment from HTTPS URL as it's not required for download.
ret = curl_url_set(url, CURLUPART_FRAGMENT, NULL, curl_flags);
if (ret) {
goto out;
}
ret = curl_url_set(url, CURLUPART_SCHEME, "https", curl_flags);
if (ret) {
goto out;
}
ret = curl_url_get(url, CURLUPART_URL, https_url, curl_flags);
if (ret) {
goto out;
}
out:
curl_url_cleanup(url);
return ret;
}
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