void zrtp_config_defaults(zrtp_config_t* config)
{
zrtp_memset(config, 0, sizeof(zrtp_config_t));
zrtp_memcpy(config->client_id, "ZRTP def. peer", 15);
config->lic_mode = ZRTP_LICENSE_MODE_PASSIVE;
ZSTR_SET_EMPTY(config->def_cache_path);
zrtp_zstrncpyc(ZSTR_GV(config->def_cache_path), "./zrtp_def_cache_path.dat", 25);
config->cache_auto_store = 1; /* cache auto flushing should be enabled by default */
#if (defined(ZRTP_USE_BUILTIN_CACHE) && (ZRTP_USE_BUILTIN_CACHE == 1))
config->cb.cache_cb.on_init = zrtp_def_cache_init;
config->cb.cache_cb.on_down = zrtp_def_cache_down;
config->cb.cache_cb.on_put = zrtp_def_cache_put;
config->cb.cache_cb.on_put_mitm = zrtp_def_cache_put_mitm;
config->cb.cache_cb.on_get = zrtp_def_cache_get;
config->cb.cache_cb.on_get_mitm = zrtp_def_cache_get_mitm;
config->cb.cache_cb.on_set_verified = zrtp_def_cache_set_verified;
config->cb.cache_cb.on_get_verified = zrtp_def_cache_get_verified;
config->cb.cache_cb.on_reset_since = zrtp_def_cache_reset_since;
config->cb.cache_cb.on_presh_counter_set = zrtp_def_cache_set_presh_counter;
config->cb.cache_cb.on_presh_counter_get = zrtp_def_cache_get_presh_counter;
#endif
#if (defined(ZRTP_USE_BUILTIN_SCEHDULER) && (ZRTP_USE_BUILTIN_SCEHDULER == 1))
config->cb.sched_cb.on_init = zrtp_def_scheduler_init;
config->cb.sched_cb.on_down = zrtp_def_scheduler_down;
config->cb.sched_cb.on_call_later = zrtp_def_scheduler_call_later;
config->cb.sched_cb.on_cancel_call_later = zrtp_def_scheduler_cancel_call_later;
config->cb.sched_cb.on_wait_call_later = zrtp_def_scheduler_wait_call_later;
#endif
}
/*----------------------------------------------------------------------------*/
static zrtp_status_t _attach_secret( zrtp_session_t *session,
zrtp_proto_secret_t* psec,
zrtp_shared_secret_t* sec,
uint8_t is_initiator)
{
zrtp_uchar32_t buff;
static const zrtp_string16_t initiator = ZSTR_INIT_WITH_CONST_CSTRING(ZRTP_ROLE_INITIATOR);
static const zrtp_string16_t responder = ZSTR_INIT_WITH_CONST_CSTRING(ZRTP_ROLE_RESPONDER);
const zrtp_string16_t* role = is_initiator ? &initiator : &responder;
const zrtp_string16_t* his_role = is_initiator ? &responder : &initiator;
ZSTR_SET_EMPTY(psec->id);
ZSTR_SET_EMPTY(psec->peer_id);
psec->secret = sec;
/*
* If secret's value is available (from the cache or from SIP) - use hmac;
* use zero-strings in other case.
*/
if (psec->secret) {
session->hash->hmac_truncated( session->hash,
ZSTR_GV(sec->value),
ZSTR_GVP(role),
ZRTP_RSID_SIZE,
ZSTR_GV(psec->id));
session->hash->hmac_truncated( session->hash,
ZSTR_GV(sec->value),
ZSTR_GVP(his_role),
ZRTP_RSID_SIZE,
ZSTR_GV(psec->peer_id));
} else {
psec->id.length = ZRTP_RSID_SIZE;
zrtp_memset(psec->id.buffer, 0, psec->id.length);
psec->peer_id.length = ZRTP_RSID_SIZE;
zrtp_memset(psec->peer_id.buffer, 0, psec->peer_id.length);
}
ZRTP_LOG(3,(_ZTU_,"\tAttach RS id=%s.\n",
hex2str((const char*)psec->id.buffer, psec->id.length, (char*)buff, sizeof(buff))));
ZRTP_LOG(3,(_ZTU_,"\tAttach RS peer_id=%s.\n",
hex2str((const char*)psec->peer_id.buffer, psec->peer_id.length, (char*)buff, sizeof(buff))));
return zrtp_status_ok;
}
static void init_rs_secret_(zrtp_shared_secret_t *sec, unsigned char val_fill) {
char val_buff[ZRTP_HASH_SIZE];
zrtp_memset(val_buff, val_fill, sizeof(val_buff));
ZSTR_SET_EMPTY(sec->value);
zrtp_zstrcpyc(ZSTR_GV(sec->value), val_buff);
sec->_cachedflag = 0;
sec->ttl = 0;
sec->lastused_at = 0;
}
void cache_setup() {
zrtp_status_t status;
/* Delete cache file from previous test if it exists. */
remove(TEST_CACHE_PATH);
secerets_to_delete_count = 0;
ZSTR_SET_EMPTY(g_zrtp_cfg.def_cache_path);
/* Configure and Initialize ZRTP cache */
zrtp_zstrcpyc(ZSTR_GV(g_zrtp_cfg.def_cache_path), TEST_CACHE_PATH);
init_rs_secret_(&rs_my4a, 'a'); init_rs_secret_(&rs_my4b, 'b'); init_rs_secret_(&rs_my4c, 'c');
init_rs_secret_(&rs_my4mitm1, '1'); init_rs_secret_(&rs_my4mitm2, '2');
init_rs_secret_(&rs_my4a_r, 0); init_rs_secret_(&rs_my4b_r, 0); init_rs_secret_(&rs_my4c_r, 0);
init_rs_secret_(&rs_my4mitm1_r, 0); init_rs_secret_(&rs_my4mitm2_r, 0);
/* It should NOT crash and return OK. */
status = zrtp_def_cache_init(&g_zrtp_cfg);
assert_int_equal(status, zrtp_status_ok);
/* Add few values into it */
printf("==> Add few test entries.\n");
status = zrtp_def_cache_put(ZSTR_GV(zid_my), ZSTR_GV(zid_a), &rs_my4a);
assert_int_equal(status, zrtp_status_ok);
status = zrtp_def_cache_put(ZSTR_GV(zid_my), ZSTR_GV(zid_b), &rs_my4b);
assert_int_equal(status, zrtp_status_ok);
status = zrtp_def_cache_put(ZSTR_GV(zid_my), ZSTR_GV(zid_c), &rs_my4c);
assert_int_equal(status, zrtp_status_ok);
status = zrtp_def_cache_put_mitm(ZSTR_GV(zid_my), ZSTR_GV(zid_mitm1), &rs_my4mitm1);
assert_int_equal(status, zrtp_status_ok);
status = zrtp_def_cache_put_mitm(ZSTR_GV(zid_my), ZSTR_GV(zid_mitm2), &rs_my4mitm2);
assert_int_equal(status, zrtp_status_ok);
status = zrtp_def_cache_put(ZSTR_GV(zid_my), ZSTR_GV(zid_c), &rs_my4c);
assert_int_equal(status, zrtp_status_ok);
/* Close the cache, it should be flushed to the file. */
printf("==> Close the cache.\n");
zrtp_def_cache_down();
printf("==> Open just prepared cache file.\n");
status = zrtp_def_cache_init(&g_zrtp_cfg);
assert_int_equal(status, zrtp_status_ok);
printf("==> Ready for the test!.\n");
}
zrtp_status_t zrtp_session_get(zrtp_session_t *session, zrtp_session_info_t *info)
{
int i=0;
if (!session || !info) {
return zrtp_status_bad_param;
}
zrtp_memset(info, 0, sizeof(zrtp_session_info_t));
ZSTR_SET_EMPTY(info->peer_clientid);
ZSTR_SET_EMPTY(info->peer_version);
ZSTR_SET_EMPTY(info->zid);
ZSTR_SET_EMPTY(info->peer_zid);
ZSTR_SET_EMPTY(info->sas1);
ZSTR_SET_EMPTY(info->sasbin);
ZSTR_SET_EMPTY(info->sas2);
ZSTR_SET_EMPTY(info->auth_name);
ZSTR_SET_EMPTY(info->cipher_name);
ZSTR_SET_EMPTY(info->hash_name);
ZSTR_SET_EMPTY(info->sas_name);
ZSTR_SET_EMPTY(info->pk_name);
info->id = session->id;
zrtp_zstrcpy(ZSTR_GV(info->zid), ZSTR_GV(session->zid));
zrtp_zstrcpy(ZSTR_GV(info->peer_zid), ZSTR_GV(session->peer_zid));
for (i=0; i<ZRTP_MAX_STREAMS_PER_SESSION; i++) {
zrtp_stream_t* full_stream = &session->streams[i];
if ((full_stream->state > ZRTP_STATE_ACTIVE) && !ZRTP_IS_STREAM_FAST(full_stream))
{
zrtp_zstrcpyc(ZSTR_GV(info->pk_name), zrtp_pkt2str[full_stream->pubkeyscheme->base.id-1]);
zrtp_zstrncpyc( ZSTR_GV(info->peer_clientid),
(const char*)full_stream->messages.peer_hello.cliend_id, 16);
zrtp_zstrncpyc( ZSTR_GV(info->peer_version),
(const char*)full_stream->messages.peer_hello.version, 4);
info->secrets_ttl = full_stream->cache_ttl;
}
}
info->sas_is_ready = (session->zrtpsess.length > 0) ? 1 : 0;
if (info->sas_is_ready) {
zrtp_zstrcpy(ZSTR_GV(info->sas1), ZSTR_GV(session->sas1));
zrtp_zstrcpy(ZSTR_GV(info->sas2), ZSTR_GV(session->sas2));
zrtp_zstrcpy(ZSTR_GV(info->sasbin), ZSTR_GV(session->sasbin));
info->sas_is_base256 = (ZRTP_SAS_BASE256 == session->sasscheme->base.id);
info->sas_is_verified = 0;
if (session->zrtp->cb.cache_cb.on_get_verified) {
session->zrtp->cb.cache_cb.on_get_verified( ZSTR_GV(session->zid),
ZSTR_GV(session->peer_zid),
&info->sas_is_verified);
}
zrtp_zstrcpyc(ZSTR_GV(info->hash_name), zrtp_hash2str[session->hash->base.id-1]);
zrtp_zstrcpyc(ZSTR_GV(info->cipher_name), zrtp_cipher2str[session->blockcipher->base.id-1]);
zrtp_zstrcpyc(ZSTR_GV(info->auth_name), zrtp_atl2str[session->authtaglength->base.id-1]);
zrtp_zstrcpyc(ZSTR_GV(info->sas_name), zrtp_sas2str[session->sasscheme->base.id-1]);
info->cached_flags = session->secrets.cached_curr;
info->matches_flags= session->secrets.matches_curr;
info->wrongs_flags = session->secrets.wrongs_curr;
}
return zrtp_status_ok;
}
zrtp_status_t zrtp_init(zrtp_config_t* config, zrtp_global_t** zrtp)
{
zrtp_global_t* new_zrtp;
zrtp_status_t s = zrtp_status_ok;
ZRTP_LOG(3, (_ZTU_,"INITIALIZING LIBZRTP...\n"));
/* Print out configuration setting */
zrtp_print_env_settings(config);
new_zrtp = zrtp_sys_alloc(sizeof(zrtp_global_t));
if (!new_zrtp) {
return zrtp_status_alloc_fail;
}
zrtp_memset(new_zrtp, 0, sizeof(zrtp_global_t));
/*
* Apply configuration according to the config
*/
new_zrtp->lic_mode = config->lic_mode;
new_zrtp->is_mitm = config->is_mitm;
ZSTR_SET_EMPTY(new_zrtp->def_cache_path);
zrtp_zstrcpy(ZSTR_GV(new_zrtp->def_cache_path), ZSTR_GV(config->def_cache_path));
zrtp_memcpy(&new_zrtp->cb, &config->cb, sizeof(zrtp_callback_t));
new_zrtp->cache_auto_store = config->cache_auto_store;
ZSTR_SET_EMPTY(new_zrtp->client_id);
zrtp_memset(new_zrtp->client_id.buffer, ' ', sizeof(zrtp_client_id_t));
zrtp_zstrncpyc( ZSTR_GV(new_zrtp->client_id),
(const char*)config->client_id,
sizeof(zrtp_client_id_t));
/*
* General Initialization
*/
init_mlist(&new_zrtp->sessions_head);
zrtp_mutex_init(&new_zrtp->sessions_protector);
init_mlist(&new_zrtp->hash_head);
init_mlist(&new_zrtp->cipher_head);
init_mlist(&new_zrtp->atl_head);
init_mlist(&new_zrtp->pktype_head);
init_mlist(&new_zrtp->sas_head);
/* Init RNG context */
s = zrtp_init_rng(new_zrtp);
if (zrtp_status_ok != s) {
ZRTP_LOG(1, (_ZTU_,"ERROR! zrtp_init_rng() failed:%s.\n", zrtp_log_status2str(s)));
return zrtp_status_rng_fail;
}
/* Initialize SRTP engine */
s = zrtp_srtp_init(new_zrtp);
if (zrtp_status_ok != s) {
ZRTP_LOG(1, (_ZTU_,"ERROR! zrtp_srtp_init() failed:<%s>\n", zrtp_log_status2str(s)));
return zrtp_status_fail;
}
if (new_zrtp->cb.cache_cb.on_init) {
s = new_zrtp->cb.cache_cb.on_init(new_zrtp);
if (zrtp_status_ok != s) {
ZRTP_LOG(1, (_ZTU_,"ERROR! cache on_init() callback failed <%s>\n", zrtp_log_status2str(s)));
zrtp_srtp_down(new_zrtp);
return zrtp_status_fail;
}
}
if (new_zrtp->cb.sched_cb.on_init) {
s = new_zrtp->cb.sched_cb.on_init(new_zrtp);
if (zrtp_status_ok != s) {
ZRTP_LOG(1, (_ZTU_,"ERROR! scheduler on_init() callback failed <%s>\n", zrtp_log_status2str(s)));
zrtp_srtp_down(new_zrtp);
return zrtp_status_fail;
}
}
/* Load default crypto-components */
zrtp_prepare_pkt(new_zrtp);
zrtp_defaults_sas(new_zrtp);
zrtp_defaults_pkt(new_zrtp);
zrtp_defaults_atl(new_zrtp);
zrtp_defaults_aes_cipher(new_zrtp);
zrtp_defaults_hash(new_zrtp);
*zrtp = new_zrtp;
ZRTP_LOG(3, (_ZTU_,"INITIALIZING LIBZRTP - DONE\n"));
return s;
}
/*----------------------------------------------------------------------------*/
zrtp_status_t zrtp_stream_attach(zrtp_session_t *session, zrtp_stream_t** stream)
{
uint32_t i = 0;
zrtp_status_t s = zrtp_status_fail;
zrtp_stream_t* new_stream = NULL;
ZRTP_LOG(3, (_ZTU_,"ATTACH NEW STREAM to sID=%d:\n", session->id));
/*
* Initialize first unused stream. If there are no available streams return error.
*/
zrtp_mutex_lock(session->streams_protector);
for (i=0; i<ZRTP_MAX_STREAMS_PER_SESSION; i++) {
if (ZRTP_STATE_NONE == session->streams[i].state) {
new_stream = &session->streams[i];
zrtp_memset(new_stream, 0, sizeof(zrtp_stream_t));
break;
}
}
zrtp_mutex_unlock(session->streams_protector);
if (!new_stream) {
ZRTP_LOG(1, (_ZTU_,"\tWARNING! Can't attach one more stream. Limit is reached."
" Use #ZRTP_MAX_STREAMS_PER_SESSION. sID=%u\n", session->id));
return zrtp_status_alloc_fail;
}
/*
* Initialize the private data stream with default initial values
*/
zrtp_mutex_init(&new_stream->stream_protector);
_zrtp_change_state(new_stream, ZRTP_STATE_ACTIVE);
new_stream->mode = ZRTP_STREAM_MODE_CLEAR;
new_stream->id = session->zrtp->streams_count++;
new_stream->session = session;
new_stream->zrtp = session->zrtp;
new_stream->mitm_mode = ZRTP_MITM_MODE_UNKN;
new_stream->is_hello_received = 0;
ZSTR_SET_EMPTY(new_stream->cc.hmackey);
ZSTR_SET_EMPTY(new_stream->cc.peer_hmackey);
ZSTR_SET_EMPTY(new_stream->cc.zrtp_key);
ZSTR_SET_EMPTY(new_stream->cc.peer_zrtp_key);
new_stream->dh_cc.initialized_with = ZRTP_COMP_UNKN;
bnBegin(&new_stream->dh_cc.peer_pv);
ZSTR_SET_EMPTY(new_stream->dh_cc.dhss);
ZRTP_LOG(3, (_ZTU_,"\tEmpty slot was found - initializing new stream with ID=%u.\n", new_stream->id));
do {
zrtp_string32_t hash_buff = ZSTR_INIT_EMPTY(hash_buff);
zrtp_hash_t *hash = zrtp_comp_find(ZRTP_CC_HASH, ZRTP_HASH_SHA256, new_stream->zrtp);
s = zrtp_status_algo_fail;
if (sizeof(uint16_t) != zrtp_randstr( new_stream->zrtp,
(uint8_t*)&new_stream->media_ctx.high_out_zrtp_seq,
sizeof(uint16_t))) {
break;
}
/*
* Compute and store message hashes to prevent DoS attacks.
* Generate H0 as a random nonce and compute H1, H2 and H3
* using the leftmost 128 bits from every hash.
* Then insert these directly into the message structures.
*/
zrtp_memset(&new_stream->messages, 0, sizeof(new_stream->messages));
ZSTR_SET_EMPTY(new_stream->messages.h0);
ZSTR_SET_EMPTY(new_stream->messages.signaling_hash);
/* Generate Random nonce, compute H1 and store in the DH packet */
new_stream->messages.h0.length = (uint16_t)zrtp_randstr( new_stream->zrtp,
(unsigned char*)new_stream->messages.h0.buffer,
ZRTP_MESSAGE_HASH_SIZE);
if (ZRTP_MESSAGE_HASH_SIZE != new_stream->messages.h0.length) {
break;
}
s = hash->hash(hash, ZSTR_GV(new_stream->messages.h0), ZSTR_GV(hash_buff));
if (zrtp_status_ok != s) {
break;
}
zrtp_memcpy(new_stream->messages.dhpart.hash, hash_buff.buffer, ZRTP_MESSAGE_HASH_SIZE);
/* Compute H2 for the Commit */
s = hash->hash_c(hash, (char*)new_stream->messages.dhpart.hash, ZRTP_MESSAGE_HASH_SIZE, ZSTR_GV(hash_buff));
if (zrtp_status_ok != s) {
break;
}
zrtp_memcpy(new_stream->messages.commit.hash, hash_buff.buffer, ZRTP_MESSAGE_HASH_SIZE);
/* Compute H3 for the Hello message */
s = hash->hash_c(hash, (char*)new_stream->messages.commit.hash, ZRTP_MESSAGE_HASH_SIZE, ZSTR_GV(hash_buff));
if (zrtp_status_ok != s) {
break;
}
zrtp_memcpy(new_stream->messages.hello.hash, hash_buff.buffer, ZRTP_MESSAGE_HASH_SIZE);
s = zrtp_status_ok;
} while (0);
if (zrtp_status_ok != s) {
ZRTP_LOG(1, (_ZTU_,"\tERROR! Fail to compute messages hashes <%s>.\n", zrtp_log_status2str(s)));
return s;
}
/*
* Preparing HELLO based on user's profile
*/
ZRTP_LOG(3, (_ZTU_,"\tPreparing ZRTP Hello according to the Session profile.\n"));
{
zrtp_packet_Hello_t* hello = &new_stream->messages.hello;
uint8_t i = 0;
int8_t* comp_ptr = NULL;
/* Set Protocol Version and ClientID */
zrtp_memcpy(hello->version, ZRTP_PROTOCOL_VERSION, ZRTP_VERSION_SIZE);
zrtp_memcpy(hello->cliend_id, session->zrtp->client_id.buffer, session->zrtp->client_id.length);
/* Set flags. */
hello->pasive = (ZRTP_LICENSE_MODE_PASSIVE == session->zrtp->lic_mode) ? 1 : 0;
hello->uflag = (ZRTP_LICENSE_MODE_UNLIMITED == session->zrtp->lic_mode) ? 1 : 0;
hello->mitmflag = session->zrtp->is_mitm;
hello->sigflag = 0;
zrtp_memcpy(hello->zid, session->zid.buffer, session->zid.length);
comp_ptr = (int8_t*)hello->comp;
i = 0;
while ( session->profile.hash_schemes[i]) {
zrtp_memcpy( comp_ptr,
zrtp_comp_id2type(ZRTP_CC_HASH, session->profile.hash_schemes[i++]),
ZRTP_COMP_TYPE_SIZE );
comp_ptr += ZRTP_COMP_TYPE_SIZE;
}
hello->hc = i;
i = 0;
while (session->profile.cipher_types[i]) {
zrtp_memcpy( comp_ptr,
zrtp_comp_id2type(ZRTP_CC_CIPHER, session->profile.cipher_types[i++]),
ZRTP_COMP_TYPE_SIZE );
comp_ptr += ZRTP_COMP_TYPE_SIZE;
}
hello->cc = i;
i = 0;
while (session->profile.auth_tag_lens[i] ) {
zrtp_memcpy( comp_ptr,
zrtp_comp_id2type(ZRTP_CC_ATL, session->profile.auth_tag_lens[i++]),
ZRTP_COMP_TYPE_SIZE );
comp_ptr += ZRTP_COMP_TYPE_SIZE;
}
hello->ac = i;
i = 0;
while (session->profile.pk_schemes[i] ) {
zrtp_memcpy( comp_ptr,
zrtp_comp_id2type(ZRTP_CC_PKT, session->profile.pk_schemes[i++]),
ZRTP_COMP_TYPE_SIZE );
comp_ptr += ZRTP_COMP_TYPE_SIZE;
}
hello->kc = i;
i = 0;
while (session->profile.sas_schemes[i]) {
zrtp_memcpy( comp_ptr,
zrtp_comp_id2type(ZRTP_CC_SAS, session->profile.sas_schemes[i++]),
ZRTP_COMP_TYPE_SIZE );
comp_ptr += ZRTP_COMP_TYPE_SIZE;
}
hello->sc = i;
/*
* Hmac will appear at the end of the message, after the dynamic portion.
* i is the length of the dynamic part.
*/
i = (hello->hc + hello->cc + hello->ac + hello->kc + hello->sc) * ZRTP_COMP_TYPE_SIZE;
_zrtp_packet_fill_msg_hdr( new_stream,
ZRTP_HELLO,
ZRTP_HELLO_STATIC_SIZE + i + ZRTP_HMAC_SIZE,
&hello->hdr);
}
*stream = new_stream;
ZRTP_LOG(3, (_ZTU_,"ATTACH NEW STREAM - DONE.\n"));
return zrtp_status_ok;
}
/*----------------------------------------------------------------------------*/
zrtp_status_t zrtp_session_init( zrtp_global_t* zrtp,
zrtp_profile_t* profile,
zrtp_zid_t zid,
zrtp_signaling_role_t role,
zrtp_session_t **session)
{
uint32_t i = 0;
zrtp_status_t s = zrtp_status_fail;
zrtp_session_t* new_session = NULL;
if (!zrtp) {
return zrtp_status_bad_param;
}
new_session = zrtp_sys_alloc(sizeof(zrtp_session_t));
if (!new_session) {
return zrtp_status_alloc_fail;
}
zrtp_memset(new_session, 0, sizeof(zrtp_session_t));
new_session->id = zrtp->sessions_count++;
{
zrtp_uchar32_t buff;
ZRTP_LOG(3, (_ZTU_,"START SESSION INITIALIZATION. sID=%u.\n", new_session->id));
ZRTP_LOG(3, (_ZTU_,"ZID=%s.\n", hex2str((const char*)zid, sizeof(zrtp_uchar12_t), (char*)buff, sizeof(buff)) ));
}
do {
/*
* Apply profile for the stream context: set flags and prepare Hello packet.
* If profile structure isn't provided, generate default.
*/
if (!profile) {
ZRTP_LOG(1, (_ZTU_,"Profile in NULL - loading default one.\n"));
zrtp_profile_defaults(&new_session->profile, zrtp);
} else {
ZRTP_LOG(1, (_ZTU_,"Loading User's profile:\n"));
if (zrtp_status_ok != zrtp_profile_check(profile, zrtp)) {
ZRTP_LOG(1, (_ZTU_,"ERROR! Can't apply wrong profile to the session sID=%u.\n", new_session->id));
break;
}
/* Adjust user's settings: force SHA-384 hash for ECDH-384P */
if (zrtp_profile_find(profile, ZRTP_CC_PKT, ZRTP_PKTYPE_EC384P) > 0) {
ZRTP_LOG(3, (_ZTU_,"User wants ECDH384 - auto-adjust profile to use SHA-384.\n"));
profile->hash_schemes[0] = ZRTP_HASH_SHA384;
profile->hash_schemes[1] = ZRTP_HASH_SHA256;
profile->hash_schemes[2] = 0;
}
zrtp_memcpy(&new_session->profile, profile, sizeof(zrtp_profile_t));
{
int i;
ZRTP_LOG(3, (_ZTU_," allowclear: %s\n", profile->allowclear?"ON":"OFF"));
ZRTP_LOG(3, (_ZTU_," autosecure: %s\n", profile->autosecure?"ON":"OFF"));
ZRTP_LOG(3, (_ZTU_," disclose_bit: %s\n", profile->disclose_bit?"ON":"OFF"));
ZRTP_LOG(3, (_ZTU_," signal. role: %s\n", zrtp_log_sign_role2str(role)));
ZRTP_LOG(3, (_ZTU_," TTL: %u\n", profile->cache_ttl));
ZRTP_LOG(3, (_ZTU_," SAS schemes: "));
i=0;
while (profile->sas_schemes[i]) {
ZRTP_LOGC(3, ("%.4s ", zrtp_comp_id2type(ZRTP_CC_SAS, profile->sas_schemes[i++])));
}
ZRTP_LOGC(3, ("\n")); ZRTP_LOG(1, (_ZTU_," Ciphers: "));
i=0;
while (profile->cipher_types[i]) {
ZRTP_LOGC(3, ("%.4s ", zrtp_comp_id2type(ZRTP_CC_CIPHER, profile->cipher_types[i++])));
}
ZRTP_LOGC(3, ("\n")); ZRTP_LOG(1, (_ZTU_," PK schemes: "));
i=0;
while (profile->pk_schemes[i]) {
ZRTP_LOGC(3, ("%.4s ", zrtp_comp_id2type(ZRTP_CC_PKT, profile->pk_schemes[i++])));
}
ZRTP_LOGC(3, ("\n")); ZRTP_LOG(1, (_ZTU_," ATL: "));
i=0;
while (profile->auth_tag_lens[i]) {
ZRTP_LOGC(3, ("%.4s ", zrtp_comp_id2type(ZRTP_CC_ATL, profile->auth_tag_lens[i++])));
}
ZRTP_LOGC(3, ("\n")); ZRTP_LOG(1, (_ZTU_," Hashes: "));
i=0;
while (profile->hash_schemes[i]) {
ZRTP_LOGC(3, ("%.4s ", zrtp_comp_id2type(ZRTP_CC_HASH, profile->hash_schemes[i++])));
}
ZRTP_LOGC(3, ("\n"));
}
}
/* Set ZIDs */
ZSTR_SET_EMPTY(new_session->zid);
ZSTR_SET_EMPTY(new_session->peer_zid);
zrtp_zstrncpyc(ZSTR_GV(new_session->zid), (const char*)zid, sizeof(zrtp_zid_t));
new_session->zrtp = zrtp;
new_session->signaling_role = role;
new_session->mitm_alert_detected = 0;
/*
* Allocate memory for holding secrets and initialize with random values.
* Actual values will be written from the cache at the beginning of the protocol.
*/
new_session->secrets.rs1 = _zrtp_alloc_shared_secret(new_session);
new_session->secrets.rs2 = _zrtp_alloc_shared_secret(new_session);
new_session->secrets.auxs = _zrtp_alloc_shared_secret(new_session);
new_session->secrets.pbxs = _zrtp_alloc_shared_secret(new_session);
if ( !new_session->secrets.rs1 || !new_session->secrets.rs2 ||
!new_session->secrets.auxs || !new_session->secrets.pbxs) {
ZRTP_LOG(1, (_ZTU_,"ERROR! Can't allocate shared secrets sID=%u\n.", new_session->id));
s = zrtp_status_alloc_fail;
break;
}
/* Initialize SAS values */
ZSTR_SET_EMPTY(new_session->sas1);
ZSTR_SET_EMPTY(new_session->sas2);
ZSTR_SET_EMPTY(new_session->sasbin);
ZSTR_SET_EMPTY(new_session->zrtpsess);
/* Clear all stream structures */
for (i=0; i<ZRTP_MAX_STREAMS_PER_SESSION ; i++) {
new_session->streams[i].state = ZRTP_STATE_NONE;
new_session->streams[i].prev_state = ZRTP_STATE_NONE;
new_session->streams[i].mode = ZRTP_STREAM_MODE_UNKN;
}
/* Initialize synchronization objects */
s = zrtp_mutex_init(&new_session->streams_protector);
if (zrtp_status_ok != s) {
ZRTP_LOG(1, (_ZTU_,"ERROR! can't initialize Stream protector. sID=%u.\n", new_session->id));
break;
}
s = zrtp_mutex_init(&new_session->init_protector);
if (zrtp_status_ok != s) {
ZRTP_LOG(1, (_ZTU_,"ERROR! can't initialize Init protector. sID=%u.\n", new_session->id));
break;
}
s = zrtp_status_ok;
} while (0);
if (zrtp_status_ok != s) {
zrtp_sys_free(new_session);
return s;
}
/* Add new session to the global list */
zrtp_mutex_lock(zrtp->sessions_protector);
mlist_add(&zrtp->sessions_head, &new_session->_mlist);
zrtp_mutex_unlock(zrtp->sessions_protector);
*session = new_session;
ZRTP_LOG(3, (_ZTU_,"Session initialization - DONE. sID=%u.\n\n", new_session->id));
return zrtp_status_ok;
}
zrtp_status_t _zrtp_protocol_init(zrtp_stream_t *stream, uint8_t is_initiator, zrtp_protocol_t **protocol)
{
zrtp_protocol_t *new_proto = NULL;
zrtp_status_t s = zrtp_status_ok;
ZRTP_LOG(3,(_ZTU_,"\tInit %s Protocol ID=%u mode=%s...\n",
is_initiator ? "INITIATOR's" : "RESPONDER's", stream->id, zrtp_log_mode2str(stream->mode)));
/* Destroy previous protocol structure (Responder or Preshared) */
if (*protocol) {
_zrtp_protocol_destroy(*protocol);
*protocol = NULL;
}
/* Allocate memory for all branching structures */
do
{
new_proto = zrtp_sys_alloc(sizeof(zrtp_protocol_t));
if (!new_proto) {
s = zrtp_status_alloc_fail;
break;
}
zrtp_memset(new_proto, 0, sizeof(zrtp_protocol_t));
new_proto->cc = zrtp_sys_alloc(sizeof(zrtp_proto_crypto_t));
if (!new_proto->cc) {
s = zrtp_status_alloc_fail;
break;
}
zrtp_memset(new_proto->cc, 0, sizeof(zrtp_proto_crypto_t));
/* Create and Initialize DH crypto context (for DH streams only) */
if (ZRTP_IS_STREAM_DH(stream)) {
if (stream->dh_cc.initialized_with != stream->pubkeyscheme->base.id) {
stream->pubkeyscheme->initialize(stream->pubkeyscheme, &stream->dh_cc);
stream->dh_cc.initialized_with = stream->pubkeyscheme->base.id;
}
}
/* Initialize main structure at first: functions pointers and generate nonce */
new_proto->type = is_initiator ? ZRTP_STATEMACHINE_INITIATOR : ZRTP_STATEMACHINE_RESPONDER;
new_proto->context = stream;
/* Initialize protocol crypto context and prepare it for further usage */
ZSTR_SET_EMPTY(new_proto->cc->kdf_context);
ZSTR_SET_EMPTY(new_proto->cc->s0);
ZSTR_SET_EMPTY(new_proto->cc->mes_hash);
ZSTR_SET_EMPTY(new_proto->cc->hv);
ZSTR_SET_EMPTY(new_proto->cc->peer_hv);
if (ZRTP_IS_STREAM_DH(stream)) {
_attach_secret(stream->session, &new_proto->cc->rs1, stream->session->secrets.rs1, is_initiator);
_attach_secret(stream->session, &new_proto->cc->rs2, stream->session->secrets.rs2, is_initiator);
_attach_secret(stream->session, &new_proto->cc->auxs, stream->session->secrets.auxs, is_initiator);
_attach_secret(stream->session, &new_proto->cc->pbxs, stream->session->secrets.pbxs, is_initiator);
}
s = zrtp_status_ok;
*protocol = new_proto;
} while (0);
if (s != zrtp_status_ok) {
ZRTP_LOG(1,(_ZTU_,"\tERROR! _zrtp_protocol_attach() with code %s.\n", zrtp_log_status2str(s)));
if (new_proto && new_proto->cc) {
zrtp_sys_free(new_proto->cc);
}
if (new_proto) {
zrtp_sys_free(new_proto);
}
*protocol = NULL;
}
return s;
}
/*----------------------------------------------------------------------------*/
zrtp_status_t _zrtp_set_public_value( zrtp_stream_t *stream,
int is_initiator)
{
/*
* This function performs the following actions according to ZRTP draft 5.6
* a) Computes total hash;
* b) Calculates DHResult;
* c) Computes final stream key S0, based on DHSS and retained secrets;
* d) Computes HMAC Key and ZRTP key;
* e) Computes srtp keys and salts and creates srtp session.
*/
zrtp_session_t *session = stream->session;
zrtp_proto_crypto_t* cc = stream->protocol->cc;
void* hash_ctx = NULL;
static const zrtp_string32_t hmac_keyi_label = ZSTR_INIT_WITH_CONST_CSTRING(ZRTP_INITIATOR_HMAKKEY_STR);
static const zrtp_string32_t hmac_keyr_label = ZSTR_INIT_WITH_CONST_CSTRING(ZRTP_RESPONDER_HMAKKEY_STR);
static const zrtp_string32_t srtp_mki_label = ZSTR_INIT_WITH_CONST_CSTRING(ZRTP_INITIATOR_KEY_STR);
static const zrtp_string32_t srtp_msi_label = ZSTR_INIT_WITH_CONST_CSTRING(ZRTP_INITIATOR_SALT_STR);
static const zrtp_string32_t srtp_mkr_label = ZSTR_INIT_WITH_CONST_CSTRING(ZRTP_RESPONDER_KEY_STR);
static const zrtp_string32_t srtp_msr_label = ZSTR_INIT_WITH_CONST_CSTRING(ZRTP_RESPONDER_SALT_STR);
static const zrtp_string32_t zrtp_keyi_label = ZSTR_INIT_WITH_CONST_CSTRING(ZRTP_INITIATOR_ZRTPKEY_STR);
static const zrtp_string32_t zrtp_keyr_label = ZSTR_INIT_WITH_CONST_CSTRING(ZRTP_RESPONDER_ZRTPKEY_STR);
uint32_t cipher_key_length = (ZRTP_CIPHER_AES128 == session->blockcipher->base.id) ? 16 : 32;
const zrtp_string32_t *output_mk_label;
const zrtp_string32_t *output_ms_label;
const zrtp_string32_t *input_mk_label;
const zrtp_string32_t *input_ms_label;
const zrtp_string32_t *hmac_key_label;
const zrtp_string32_t *peer_hmac_key_label;
const zrtp_string32_t *zrtp_key_label;
const zrtp_string32_t *peer_zrtp_key_label;
/* Define roles and prepare structures */
if (is_initiator) {
output_mk_label = &srtp_mki_label;
output_ms_label = &srtp_msi_label;
input_mk_label = &srtp_mkr_label;
input_ms_label = &srtp_msr_label;
hmac_key_label = &hmac_keyi_label;
peer_hmac_key_label = &hmac_keyr_label;
zrtp_key_label = &zrtp_keyi_label;
peer_zrtp_key_label = &zrtp_keyr_label;
} else {
output_mk_label = &srtp_mkr_label;
output_ms_label = &srtp_msr_label;
input_mk_label = &srtp_mki_label;
input_ms_label = &srtp_msi_label;
hmac_key_label = &hmac_keyr_label;
peer_hmac_key_label = &hmac_keyi_label;
zrtp_key_label = &zrtp_keyr_label;
peer_zrtp_key_label = &zrtp_keyi_label;
}
ZRTP_LOG(3, (_ZTU_,"---------------------------------------------------\n"));
ZRTP_LOG(3,(_ZTU_,"\tSWITCHING TO SRTP. ID=%u\n", zrtp_log_mode2str(stream->mode), stream->id));
ZRTP_LOG(3,(_ZTU_,"\tI %s\n", is_initiator ? "Initiator" : "Responder"));
/*
* Compute total messages hash:
* total_hash = hash(Hello of responder | Commit | DHPart1 | DHPart2) for DH streams
* total_hash = hash(Hello of responder | Commit ) for Fast modes.
*/
{
uint8_t* tok = NULL;
uint16_t tok_len = 0;
hash_ctx = session->hash->hash_begin(session->hash);
if (0 == hash_ctx) {
return zrtp_status_fail;
}
tok = is_initiator ? (uint8_t*)&stream->messages.peer_hello : (uint8_t*) &stream->messages.hello;
tok_len = is_initiator ? stream->messages.peer_hello.hdr.length : stream->messages.hello.hdr.length;
tok_len = zrtp_ntoh16(tok_len)*4;
session->hash->hash_update(session->hash, hash_ctx, (const int8_t*)tok, tok_len);
tok = is_initiator ? (uint8_t*)&stream->messages.commit : (uint8_t*)&stream->messages.peer_commit;
tok_len = is_initiator ? stream->messages.commit.hdr.length : stream->messages.peer_commit.hdr.length;
tok_len = zrtp_ntoh16(tok_len)*4;
session->hash->hash_update(session->hash, hash_ctx, (const int8_t*)tok, tok_len);
if (ZRTP_IS_STREAM_DH(stream))
{
tok = (uint8_t*) (is_initiator ? &stream->messages.peer_dhpart : &stream->messages.dhpart);
tok_len = is_initiator ? stream->messages.peer_dhpart.hdr.length : stream->messages.dhpart.hdr.length;
tok_len = zrtp_ntoh16(tok_len)*4;
session->hash->hash_update(session->hash, hash_ctx, (const int8_t*)tok, tok_len);
tok = (uint8_t*)(is_initiator ? &stream->messages.dhpart : &stream->messages.peer_dhpart);
tok_len = is_initiator ? stream->messages.dhpart.hdr.length : stream->messages.peer_dhpart.hdr.length;
tok_len = zrtp_ntoh16(tok_len)*4;
session->hash->hash_update(session->hash, hash_ctx, (const int8_t*)tok, tok_len);
}
session->hash->hash_end(session->hash, hash_ctx, ZSTR_GV(cc->mes_hash));
hash_ctx = NULL;
} /* total hash computing */
/* Total Hash is ready and we can create KDF_Context */
zrtp_zstrcat(ZSTR_GV(cc->kdf_context), is_initiator ? ZSTR_GV(session->zrtp->zid) : ZSTR_GV(session->peer_zid));
zrtp_zstrcat(ZSTR_GV(cc->kdf_context), is_initiator ? ZSTR_GV(session->peer_zid) : ZSTR_GV(session->zrtp->zid));
zrtp_zstrcat(ZSTR_GV(cc->kdf_context), ZSTR_GV(cc->mes_hash));
/* Derive stream key S0 according to key exchange scheme */
if (zrtp_status_ok != _derive_s0(stream, is_initiator)) {
return zrtp_status_fail;
}
/*
* Compute HMAC keys. These values will be used after confirmation:
* hmackeyi = KDF(s0, "Initiator HMAC key", KDF_Context, negotiated hash length)
* hmackeyr = KDF(s0, "Responder HMAC key", KDF_Context, negotiated hash length)
*/
_zrtp_kdf( stream,
ZSTR_GV(cc->s0),
ZSTR_GVP(hmac_key_label),
ZSTR_GV(stream->protocol->cc->kdf_context),
session->hash->digest_length,
ZSTR_GV(stream->cc.hmackey));
_zrtp_kdf( stream,
ZSTR_GV(cc->s0),
ZSTR_GVP(peer_hmac_key_label),
ZSTR_GV(stream->protocol->cc->kdf_context),
session->hash->digest_length,
ZSTR_GV(stream->cc.peer_hmackey));
/*
* Computing ZRTP keys for protection of the Confirm packet:
* zrtpkeyi = KDF(s0, "Initiator ZRTP key", KDF_Context, negotiated AES key length)
* zrtpkeyr = KDF(s0, "Responder ZRTP key", KDF_Context, negotiated AES key length)
*/
_zrtp_kdf( stream,
ZSTR_GV(cc->s0),
ZSTR_GVP(zrtp_key_label),
ZSTR_GV(stream->protocol->cc->kdf_context),
cipher_key_length,
ZSTR_GV(stream->cc.zrtp_key));
_zrtp_kdf( stream,
ZSTR_GV(cc->s0),
ZSTR_GVP(peer_zrtp_key_label),
ZSTR_GV(stream->protocol->cc->kdf_context),
cipher_key_length,
ZSTR_GV(stream->cc.peer_zrtp_key));
#if (defined(ZRTP_DEBUG_ZRTP_KEYS) && ZRTP_DEBUG_ZRTP_KEYS == 1)
{
char print_buff[256];
ZRTP_LOG(3,(_ZTU_,"\t Messages hash:%s\n", hex2str(cc->mes_hash.buffer, cc->mes_hash.length, print_buff, sizeof(print_buff))));
ZRTP_LOG(3,(_ZTU_,"\t S0:%s\n", hex2str(cc->s0.buffer, cc->s0.length, print_buff, sizeof(print_buff))));
ZRTP_LOG(3,(_ZTU_,"\t ZRTP Sess:%s\n", hex2str(session->zrtpsess.buffer, session->zrtpsess.length, print_buff, sizeof(print_buff))));
ZRTP_LOG(3,(_ZTU_,"\t hmackey:%s\n", hex2str(stream->cc.hmackey.buffer, stream->cc.hmackey.length, print_buff, sizeof(print_buff))));
ZRTP_LOG(3,(_ZTU_,"\t peer_hmackeyr:%s\n", hex2str(stream->cc.peer_hmackey.buffer, stream->cc.peer_hmackey.length, print_buff, sizeof(print_buff))));
ZRTP_LOG(3,(_ZTU_,"\t ZRTP key:%s\n", hex2str(stream->cc.zrtp_key.buffer, stream->cc.zrtp_key.length, print_buff, sizeof(print_buff))));
ZRTP_LOG(3,(_ZTU_,"\t Peer ZRTP key:%s\n", hex2str(stream->cc.peer_zrtp_key.buffer, stream->cc.peer_zrtp_key.length, print_buff, sizeof(print_buff))));
}
#endif
/*
* Preparing SRTP crypto engine:
* srtpkeyi = KDF(s0, "Initiator SRTP master key", KDF_Context, negotiated AES key length)
* srtpsalti = KDF(s0, "Initiator SRTP master salt", KDF_Context, 112)
* srtpkeyr = KDF(s0, "Responder SRTP master key", KDF_Context, negotiated AES key length)
* srtpsaltr = KDF(s0, "Responder SRTP master salt", KDF_Context, 112)
*/
{
zrtp_srtp_profile_t iprof;
zrtp_srtp_profile_t oprof;
ZSTR_SET_EMPTY(iprof.salt);
ZSTR_SET_EMPTY(iprof.key);
iprof.rtp_policy.cipher = session->blockcipher;
iprof.rtp_policy.auth_tag_len = session->authtaglength;
iprof.rtp_policy.hash = zrtp_comp_find(ZRTP_CC_HASH, ZRTP_SRTP_HASH_HMAC_SHA1, session->zrtp);
iprof.rtp_policy.auth_key_len = 20;
iprof.rtp_policy.cipher_key_len = cipher_key_length;
zrtp_memcpy(&iprof.rtcp_policy, &iprof.rtp_policy, sizeof(iprof.rtcp_policy));
iprof.dk_cipher = session->blockcipher;
zrtp_memcpy(&oprof, &iprof, sizeof(iprof));
_zrtp_kdf( stream,
ZSTR_GV(cc->s0),
ZSTR_GVP(input_mk_label),
ZSTR_GV(stream->protocol->cc->kdf_context),
cipher_key_length,
ZSTR_GV(iprof.key));
_zrtp_kdf( stream,
ZSTR_GV(cc->s0),
ZSTR_GVP(input_ms_label),
ZSTR_GV(stream->protocol->cc->kdf_context),
14,
ZSTR_GV(iprof.salt));
_zrtp_kdf( stream,
ZSTR_GV(cc->s0),
ZSTR_GVP(output_mk_label),
ZSTR_GV(stream->protocol->cc->kdf_context),
cipher_key_length,
ZSTR_GV(oprof.key));
_zrtp_kdf( stream,
ZSTR_GV(cc->s0),
ZSTR_GVP(output_ms_label),
ZSTR_GV(stream->protocol->cc->kdf_context),
14,
ZSTR_GV(oprof.salt));
stream->protocol->_srtp = zrtp_srtp_create(session->zrtp->srtp_global, &iprof, &oprof);
/* Profiles and keys in them are not needed anymore - clear them */
zrtp_memset(&iprof, 0, sizeof(iprof));
zrtp_memset(&oprof, 0, sizeof(oprof));
if (!stream->protocol->_srtp) {
ZRTP_LOG(1,(_ZTU_,"\tERROR! Can't initialize SRTP engine. ID=%u\n", stream->id));
return zrtp_status_fail;
}
} /* SRTP initialization */
return zrtp_status_ok;
}
