mirror/btstack
1
0
Fork 0
mirror of https://github.com/bluekitchen/btstack.git synced 2025-01-26 03:35:20 +00:00
Code Issues Packages Projects Releases Wiki Activity

sm: use AES Engine for f4 (confirm validation)

Browse Source
This commit is contained in:
Matthias Ringwald 2016-05-27 18:57:59 +02:00
parent aec9414068
commit 688a08f9c2
2 changed files with 103 additions and 83 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

184
src/ble/sm.c
View File

@ -622,20 +622,6 @@ static void aes_cmac(sm_key_t aes_cmac, const sm_key_t key, const uint8_t * data
aes128_calc_cyphertext(key, sm_cmac_y, aes_cmac);
}
static void f4(sm_key_t res, const sm_key256_t u, const sm_key256_t v, const sm_key_t x, uint8_t z){
uint8_t buffer[65];
memcpy(buffer, u, 32);
memcpy(buffer+32, v, 32);
buffer[64] = z;
log_info("f4 key");
log_info_hexdump(x, 16);
log_info("f4 message");
log_info_hexdump(buffer, sizeof(buffer));
aes_cmac(res, x, buffer, sizeof(buffer));
log_info("f4 result");
log_info_hexdump(res, sizeof(sm_key_t));
}
const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE};
const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 };
const uint8_t f5_length[] = { 0x01, 0x00};
@ -1366,16 +1352,76 @@ static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){
sm_conn->sm_le_db_index = le_db_index;
}
static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){
setup->sm_pairing_failed_reason = reason;
sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED;
}
static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){
sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON);
}
#ifdef ENABLE_LE_SECURE_CONNECTIONS
static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){
if (sm_conn->sm_role){
// Responder
sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM;
} else {
// Initiator role
switch (setup->sm_stk_generation_method){
case JUST_WORKS:
sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND;
break;
case NK_BOTH_INPUT: {
// calc Va if numeric comparison
// TODO: use AES Engine to calculate g2
uint8_t value[32];
mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value));
uint32_t va = g2(value, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce) % 1000000;
big_endian_store_32(setup->sm_tk, 12, va);
sm_trigger_user_response(sm_conn);
break;
}
case PK_INIT_INPUT:
case PK_RESP_INPUT:
case OK_BOTH_INPUT:
if (setup->sm_passkey_bit < 20) {
sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION;
} else {
sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND;
}
break;
case OOB:
// TODO: implement SC OOB
break;
}
}
}
static uint8_t sm_sc_cmac_get_byte(uint16_t offset){
return sm_cmac_sc_buffer[offset];
}
static void sm_sc_cmac_done(uint8_t * hash){
log_info("sm_sc_cmac_done: ");
log_info_hexdump(hash, 16);
switch (sm_cmac_connection->sm_engine_state){
case SM_SC_W4_CMAC_FOR_CONFIRMATION:
memcpy(setup->sm_local_confirm, hash, 16);
sm_cmac_connection->sm_engine_state = SM_SC_SEND_CONFIRMATION;
break;
case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION:
// check
if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){
sm_pairing_error(sm_cmac_connection, SM_REASON_CONFIRM_VALUE_FAILED);
break;
}
// next state
sm_sc_state_after_receiving_random(sm_cmac_connection);
break;
default:
log_error("sm_sc_cmac_done in state %u", sm_cmac_connection->sm_engine_state);
break;
@ -1384,7 +1430,7 @@ static void sm_sc_cmac_done(uint8_t * hash){
sm_run();
}
static void f4_engine(sm_connection_t * sm_conn, sm_key_t res, const sm_key256_t u, const sm_key256_t v, const sm_key_t x, uint8_t z){
static void f4_engine(sm_connection_t * sm_conn, const sm_key256_t u, const sm_key256_t v, const sm_key_t x, uint8_t z){
sm_cmac_connection = sm_conn;
memcpy(sm_cmac_sc_buffer, u, 32);
memcpy(sm_cmac_sc_buffer+32, v, 32);
@ -1392,7 +1438,7 @@ static void f4_engine(sm_connection_t * sm_conn, sm_key_t res, const sm_key256_t
log_info("f4 key");
log_info_hexdump(x, 16);
log_info("f4 message");
log_info_hexdump(sm_cmac_sc_buffer, sizeof(sm_cmac_sc_buffer));
log_info_hexdump(sm_cmac_sc_buffer, 65);
sm_cmac_general_start(x, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done);
}
@ -1405,11 +1451,27 @@ static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){
setup->sm_passkey_bit++;
}
#ifdef USE_MBEDTLS_FOR_ECDH
uint8_t value[32];
mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value));
uint8_t local_qx[32];
mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx));
#endif
f4_engine(sm_conn, setup->sm_local_confirm, value, setup->sm_peer_qx, setup->sm_local_nonce, z);
f4_engine(sm_conn, local_qx, setup->sm_peer_qx, setup->sm_local_nonce, z);
}
static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){
uint8_t z = 0;
if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){
// some form of passkey
uint32_t pk = big_endian_read_32(setup->sm_tk, 12);
// sm_passkey_bit was increased before sending confirm value
z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1);
}
#ifdef USE_MBEDTLS_FOR_ECDH
uint8_t local_qx[32];
mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx));
#endif
f4_engine(sm_conn, setup->sm_peer_qx, local_qx, setup->sm_peer_nonce, z);
}
#endif
static void sm_run(void){
@ -1681,6 +1743,12 @@ static void sm_run(void){
connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION;
sm_sc_calculate_local_confirm(connection);
break;
case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION:
if (!sm_cmac_ready()) break;
connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION;
sm_sc_calculate_remote_confirm(connection);
break;
#endif
// initiator side
case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: {
@ -2581,6 +2649,17 @@ static inline int sm_calc_actual_encryption_key_size(int other){
return sm_max_encryption_key_size;
}
static int sm_passkey_used(stk_generation_method_t method){
switch (method){
case PK_RESP_INPUT:
case PK_INIT_INPUT:
case OK_BOTH_INPUT:
return 1;
default:
return 0;
}
}
/**
* @return ok
*/
@ -2603,16 +2682,6 @@ static int sm_validate_stk_generation_method(void){
}
}
// helper for sm_pdu_handler, calls sm_run on exit
static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){
setup->sm_pairing_failed_reason = reason;
sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED;
}
static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){
sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON);
}
static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){
if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){
@ -2822,64 +2891,13 @@ static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uin
reverse_128(&packet[1], setup->sm_peer_nonce);
// validate confirm value if Cb = f4(Pkb, Pka, Nb, z)
uint8_t z = 0;
int passkey_entry = 0;
if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){
// some form of passkey
passkey_entry = 1;
uint32_t pk = big_endian_read_32(setup->sm_tk, 12);
// sm_passkey_bit was increased before sending confirm value
z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1);
}
// only check for JUST WORK/NC in initiator role AND passkey entry
int passkey_entry = sm_passkey_used(setup->sm_stk_generation_method);
if (sm_conn->sm_role || passkey_entry) {
sm_key_t confirm_value;
#ifdef USE_MBEDTLS_FOR_ECDH
uint8_t local_qx[32];
mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx));
f4(confirm_value, setup->sm_peer_qx, local_qx, setup->sm_peer_nonce, z);
#endif
if (0 != memcmp(confirm_value, setup->sm_peer_confirm, 16)){
sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED);
break;
}
sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION;
}
if (sm_conn->sm_role){
// Responder
sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM;
} else {
// Initiator role
switch (setup->sm_stk_generation_method){
case JUST_WORKS:
sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND;
break;
case NK_BOTH_INPUT: {
// calc Va if numeric comparison
// TODO: use AES Engine to calculate g2
uint8_t value[32];
mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value));
uint32_t va = g2(value, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce) % 1000000;
big_endian_store_32(setup->sm_tk, 12, va);
sm_trigger_user_response(sm_conn);
break;
}
case PK_INIT_INPUT:
case PK_RESP_INPUT:
case OK_BOTH_INPUT:
if (setup->sm_passkey_bit < 20) {
sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION;
} else {
sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND;
}
break;
case OOB:
// TODO: implement SC OOB
break;
}
}
sm_sc_state_after_receiving_random(sm_conn);
break;
case SM_SC_W4_DHKEY_CHECK_COMMAND:

2
src/hci.h
View File

@ -308,6 +308,8 @@ typedef enum {
SM_SC_W2_CMAC_FOR_CONFIRMATION,
SM_SC_W4_CMAC_FOR_CONFIRMATION,
SM_SC_SEND_CONFIRMATION,
SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION,
SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION,
SM_SC_W4_CONFIRMATION,
SM_SC_SEND_PAIRING_RANDOM,
SM_SC_W4_PAIRING_RANDOM,