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implement sm_encryption_key_size

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matthias.ringwald@gmail.com 2014-01-06 12:07:15 +00:00
parent 8155cab62e
commit 9218acdc65
1 changed files with 21 additions and 9 deletions
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30
ble/sm.c
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@ -182,7 +182,6 @@ static uint8_t sm_accepted_stk_generation_methods;
static uint8_t sm_max_encryption_key_size;
static uint8_t sm_min_encryption_key_size;
static uint8_t sm_encryption_key_size;
static uint8_t sm_s_auth_req = 0;
static uint8_t sm_s_io_capabilities = IO_CAPABILITY_UNKNOWN;
static uint8_t sm_s_request_security = 0;
@ -202,6 +201,8 @@ static int sm_central_ah_calculation_active;
//
static uint8_t sm_s_addr_type;
static bd_addr_t sm_s_address;
static uint8_t sm_actual_encryption_key_size;
static uint8_t sm_connection_encrypted;
// PER INSTANCE DATA
@ -1086,9 +1087,9 @@ static void sm_packet_handler(uint8_t packet_type, uint16_t handle, uint8_t *pac
}
// min{}
sm_encryption_key_size = sm_max_encryption_key_size;
sm_actual_encryption_key_size = sm_max_encryption_key_size;
if (sm_m_max_encryption_key_size < sm_max_encryption_key_size){
sm_encryption_key_size = sm_m_max_encryption_key_size;
sm_actual_encryption_key_size = sm_m_max_encryption_key_size;
}
// setup key distribution
@ -1275,6 +1276,8 @@ static void sm_event_packet_handler (void * connection, uint8_t packet_type, uin
printf("Incoming connection, own address ");
print_bd_addr(sm_s_address);
sm_connection_encrypted = 0;
// request security
if (sm_s_request_security){
sm_state_responding = SM_STATE_SEND_SECURITY_REQUEST;
@ -1310,10 +1313,10 @@ static void sm_event_packet_handler (void * connection, uint8_t packet_type, uin
// re-establish used key encryption size
if (sm_max_encryption_key_size == sm_min_encryption_key_size){
sm_encryption_key_size = sm_max_encryption_key_size;
sm_actual_encryption_key_size = sm_max_encryption_key_size;
} else {
// no db for encryption size hack: encryption size is stored in lowest nibble of sm_s_rand
sm_encryption_key_size = (sm_s_rand[7] & 0x0f) + 1;
sm_actual_encryption_key_size = (sm_s_rand[7] & 0x0f) + 1;
}
log_info("LTK Request: recalculating with ediv 0x%04x", sm_s_ediv);
@ -1338,7 +1341,10 @@ static void sm_event_packet_handler (void * connection, uint8_t packet_type, uin
break;
case HCI_EVENT_ENCRYPTION_CHANGE:
log_info("Connection encrypted");
if (sm_response_handle != READ_BT_16(packet, 3)) break;
sm_connection_encrypted = packet[5];
log_info("Eencryption state change: %u", sm_connection_encrypted);
if (!sm_connection_encrypted) break;
if (sm_state_responding == SM_STATE_PH2_W4_CONNECTION_ENCRYPTED) {
sm_state_responding = SM_STATE_PH3_GET_RANDOM;
}
@ -1444,7 +1450,7 @@ static void sm_event_packet_handler (void * connection, uint8_t packet_type, uin
break;
case SM_STATE_PH2_W4_STK:
swap128(&packet[6], sm_s_ltk);
sm_truncate_key(sm_s_ltk, sm_encryption_key_size);
sm_truncate_key(sm_s_ltk, sm_actual_encryption_key_size);
print_key("stk", sm_s_ltk);
sm_state_responding = SM_STATE_PH2_SEND_STK;
break;
@ -1486,7 +1492,7 @@ static void sm_event_packet_handler (void * connection, uint8_t packet_type, uin
break;
case SM_STATE_PH4_LTK_W4_ENC:
swap128(&packet[6], sm_s_ltk);
sm_truncate_key(sm_s_ltk, sm_encryption_key_size);
sm_truncate_key(sm_s_ltk, sm_actual_encryption_key_size);
print_key("ltk", sm_s_ltk);
sm_state_responding = SM_STATE_PH4_SEND_LTK;
break;
@ -1554,7 +1560,7 @@ static void sm_event_packet_handler (void * connection, uint8_t packet_type, uin
case SM_STATE_PH3_W4_RANDOM:
swap64(&packet[6], sm_s_rand);
// no db for encryption size hack: encryption size is stored in lowest nibble of sm_s_rand
sm_s_rand[7] = (sm_s_rand[7] & 0xf0) + (sm_encryption_key_size - 1);
sm_s_rand[7] = (sm_s_rand[7] & 0xf0) + (sm_actual_encryption_key_size - 1);
sm_state_responding = SM_STATE_PH3_GET_DIV;
break;
case SM_STATE_PH3_W4_DIV:
@ -1658,6 +1664,12 @@ void sm_init(){
l2cap_register_packet_handler(sm_event_packet_handler);
}
// @returns 0 if not encrypted, 7-16 otherwise
int sm_encryption_key_size(uint8_t addr_type, bd_addr_t address){
if (!sm_connection_encrypted) return 0;
return sm_actual_encryption_key_size;
}
// GAP Bonding API
static int sm_get_connection(uint8_t addr_type, bd_addr_t address){
// TODO compare to current connection