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nest-open-source / nest-cam / 4320010 / flouride_bluetooth / fc3bdd73ab4b02696d611dd86fec6ae187c3a043 / . / bt / stack / smp / smp_keys.cc
blob: 1d65f74ca8578c282b2e8c81f33e0781840d5ea0 [file] [log] [blame]
/******************************************************************************
*
* Copyright (C) 1999-2012 Broadcom Corporation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
******************************************************************************/
/******************************************************************************
*
* This file contains security manager protocol utility functions
*
******************************************************************************/
#include "bt_target.h"
#if (SMP_INCLUDED == TRUE)
#if (SMP_DEBUG == TRUE)
#include <stdio.h>
#endif
#include <string.h>
#include "bt_utils.h"
#include "btm_ble_api.h"
#include "smp_int.h"
#include "btm_int.h"
#include "btm_ble_int.h"
#include "hcimsgs.h"
#include "aes.h"
#include "p_256_ecc_pp.h"
#include "device/include/controller.h"
#include "osi/include/osi.h"
#ifndef SMP_MAX_ENC_REPEAT
#define SMP_MAX_ENC_REPEAT 3
#endif
static void smp_rand_back(tBTM_RAND_ENC *p);
static void smp_generate_confirm(tSMP_CB *p_cb, tSMP_INT_DATA *p_data);
static void smp_generate_ltk_cont(tSMP_CB *p_cb, tSMP_INT_DATA *p_data);
static void smp_generate_y(tSMP_CB *p_cb, tSMP_INT_DATA *p);
static void smp_generate_rand_vector (tSMP_CB *p_cb, tSMP_INT_DATA *p);
static void smp_process_stk(tSMP_CB *p_cb, tSMP_ENC *p);
static void smp_calculate_comfirm_cont(tSMP_CB *p_cb, tSMP_ENC *p);
static void smp_process_confirm(tSMP_CB *p_cb, tSMP_ENC *p);
static void smp_process_compare(tSMP_CB *p_cb, tSMP_ENC *p);
static void smp_process_ediv(tSMP_CB *p_cb, tSMP_ENC *p);
static bool smp_calculate_legacy_short_term_key(tSMP_CB *p_cb, tSMP_ENC *output);
static void smp_continue_private_key_creation(tSMP_CB *p_cb, tBTM_RAND_ENC *p);
static void smp_process_private_key(tSMP_CB *p_cb);
static void smp_finish_nonce_generation(tSMP_CB *p_cb);
static void smp_process_new_nonce(tSMP_CB *p_cb);
#define SMP_PASSKEY_MASK 0xfff00000
void smp_debug_print_nbyte_little_endian(uint8_t *p, const uint8_t *key_name, uint8_t len)
{
#if (SMP_DEBUG == TRUE)
int ind;
int col_count = 32;
int row_count;
uint8_t p_buf[512];
SMP_TRACE_WARNING("%s(LSB ~ MSB):", key_name);
memset(p_buf, 0, sizeof(p_buf));
row_count = len % col_count ? len / col_count + 1: len / col_count;
ind = 0;
for (int row = 0; row < row_count; row++)
{
for (int column = 0, x = 0; (ind < len) && (column < col_count); column++, ind++)
{
x += snprintf((char *)&p_buf[x], sizeof(p_buf) - x, "%02x ", p[ind]);
}
SMP_TRACE_WARNING(" [%03d]: %s", row * col_count, p_buf);
}
#endif
}
void smp_debug_print_nbyte_big_endian (uint8_t *p, const uint8_t *key_name, uint8_t len)
{
#if (SMP_DEBUG == TRUE)
uint8_t p_buf[512];
SMP_TRACE_WARNING("%s(MSB ~ LSB):", key_name);
memset(p_buf, 0, sizeof(p_buf));
int ind = 0;
int ncols = 32; /* num entries in one line */
int nrows; /* num lines */
nrows = len % ncols ? len / ncols + 1: len / ncols;
for (int row = 0; row < nrows; row++)
{
for (int col = 0, x = 0; (ind < len) && (col < ncols); col++, ind++)
{
x += snprintf ((char *)&p_buf[len-x-1], sizeof(p_buf) - (len-x-1), "%02x ", p[ind]);
}
SMP_TRACE_WARNING("[%03d]: %s", row * ncols, p_buf);
}
#endif
}
/*******************************************************************************
**
** Function smp_encrypt_data
**
** Description This function is called to encrypt data.
** It uses AES-128 encryption algorithm.
** Plain_text is encrypted using key, the result is at p_out.
**
** Returns void
**
*******************************************************************************/
bool smp_encrypt_data (uint8_t *key, uint8_t key_len,
uint8_t *plain_text, uint8_t pt_len,
tSMP_ENC *p_out)
{
aes_context ctx;
uint8_t *p_start = NULL;
uint8_t *p = NULL;
uint8_t *p_rev_data = NULL; /* input data in big endilan format */
uint8_t *p_rev_key = NULL; /* input key in big endilan format */
uint8_t *p_rev_output = NULL; /* encrypted output in big endilan format */
SMP_TRACE_DEBUG ("%s", __func__);
if ( (p_out == NULL ) || (key_len != SMP_ENCRYT_KEY_SIZE) )
{
SMP_TRACE_ERROR ("%s failed", __func__);
return false;
}
p_start = (uint8_t *)osi_calloc(SMP_ENCRYT_DATA_SIZE * 4);
if (pt_len > SMP_ENCRYT_DATA_SIZE)
pt_len = SMP_ENCRYT_DATA_SIZE;
p = p_start;
ARRAY_TO_STREAM (p, plain_text, pt_len); /* byte 0 to byte 15 */
p_rev_data = p = p_start + SMP_ENCRYT_DATA_SIZE; /* start at byte 16 */
REVERSE_ARRAY_TO_STREAM (p, p_start, SMP_ENCRYT_DATA_SIZE); /* byte 16 to byte 31 */
p_rev_key = p; /* start at byte 32 */
REVERSE_ARRAY_TO_STREAM (p, key, SMP_ENCRYT_KEY_SIZE); /* byte 32 to byte 47 */
#if (SMP_DEBUG == TRUE && SMP_DEBUG_VERBOSE == TRUE)
smp_debug_print_nbyte_little_endian(key, (const uint8_t *)"Key", SMP_ENCRYT_KEY_SIZE);
smp_debug_print_nbyte_little_endian(p_start, (const uint8_t *)"Plain text", SMP_ENCRYT_DATA_SIZE);
#endif
p_rev_output = p;
aes_set_key(p_rev_key, SMP_ENCRYT_KEY_SIZE, &ctx);
aes_encrypt(p_rev_data, p, &ctx); /* outputs in byte 48 to byte 63 */
p = p_out->param_buf;
REVERSE_ARRAY_TO_STREAM (p, p_rev_output, SMP_ENCRYT_DATA_SIZE);
#if (SMP_DEBUG == TRUE && SMP_DEBUG_VERBOSE == TRUE)
smp_debug_print_nbyte_little_endian(p_out->param_buf, (const uint8_t *)"Encrypted text", SMP_ENCRYT_KEY_SIZE);
#endif
p_out->param_len = SMP_ENCRYT_KEY_SIZE;
p_out->status = HCI_SUCCESS;
p_out->opcode = HCI_BLE_ENCRYPT;
osi_free(p_start);
return true;
}
/*******************************************************************************
**
** Function smp_generate_passkey
**
** Description This function is called to generate passkey.
**
** Returns void
**
*******************************************************************************/
void smp_generate_passkey(tSMP_CB *p_cb,
UNUSED_ATTR tSMP_INT_DATA *p_data)
{
SMP_TRACE_DEBUG ("%s", __func__);
p_cb->rand_enc_proc_state = SMP_GEN_TK;
/* generate MRand or SRand */
btsnd_hcic_ble_rand((void *)smp_rand_back);
}
/*******************************************************************************
**
** Function smp_proc_passkey
**
** Description This function is called to process a passkey.
**
** Returns void
**
*******************************************************************************/
void smp_proc_passkey(tSMP_CB *p_cb , tBTM_RAND_ENC *p)
{
uint8_t *tt = p_cb->tk;
tSMP_KEY key;
uint32_t passkey; /* 19655 test number; */
uint8_t *pp = p->param_buf;
SMP_TRACE_DEBUG ("%s", __func__);
STREAM_TO_UINT32(passkey, pp);
passkey &= ~SMP_PASSKEY_MASK;
/* truncate by maximum value */
while (passkey > BTM_MAX_PASSKEY_VAL)
passkey >>= 1;
/* save the TK */
memset(p_cb->tk, 0, BT_OCTET16_LEN);
UINT32_TO_STREAM(tt, passkey);
key.key_type = SMP_KEY_TYPE_TK;
key.p_data = p_cb->tk;
if (p_cb->p_callback)
{
(*p_cb->p_callback)(SMP_PASSKEY_NOTIF_EVT, p_cb->pairing_bda, (tSMP_EVT_DATA *)&passkey);
}
if (p_cb->selected_association_model == SMP_MODEL_SEC_CONN_PASSKEY_DISP)
{
smp_sm_event(&smp_cb, SMP_KEY_READY_EVT, &passkey);
}
else
{
smp_sm_event(p_cb, SMP_KEY_READY_EVT, (tSMP_INT_DATA *)&key);
}
}
/*******************************************************************************
**
** Function smp_generate_stk
**
** Description This function is called to generate STK calculated by running
** AES with the TK value as key and a concatenation of the random
** values.
**
** Returns void
**
*******************************************************************************/
void smp_generate_stk(tSMP_CB *p_cb,
UNUSED_ATTR tSMP_INT_DATA *p_data)
{
tSMP_ENC output;
tSMP_STATUS status = SMP_PAIR_FAIL_UNKNOWN;
SMP_TRACE_DEBUG ("%s", __func__);
if (p_cb->le_secure_connections_mode_is_used)
{
SMP_TRACE_WARNING ("FOR LE SC LTK IS USED INSTEAD OF STK");
output.param_len = SMP_ENCRYT_KEY_SIZE;
output.status = HCI_SUCCESS;
output.opcode = HCI_BLE_ENCRYPT;
memcpy(output.param_buf, p_cb->ltk, SMP_ENCRYT_DATA_SIZE);
}
else if (!smp_calculate_legacy_short_term_key(p_cb, &output))
{
SMP_TRACE_ERROR("%s failed", __func__);
smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &status);
return;
}
smp_process_stk(p_cb, &output);
}
/*******************************************************************************
**
** Function smp_generate_srand_mrand_confirm
**
** Description This function is called to start the second pairing phase by
** start generating random number.
**
**
** Returns void
**
*******************************************************************************/
void smp_generate_srand_mrand_confirm(tSMP_CB *p_cb,
UNUSED_ATTR tSMP_INT_DATA *p_data)
{
SMP_TRACE_DEBUG ("%s", __func__);
p_cb->rand_enc_proc_state = SMP_GEN_SRAND_MRAND;
/* generate MRand or SRand */
btsnd_hcic_ble_rand((void *)smp_rand_back);
}
/*******************************************************************************
**
** Function smp_generate_rand_cont
**
** Description This function is called to generate another 64 bits random for
** MRand or Srand.
**
** Returns void
**
*******************************************************************************/
void smp_generate_rand_cont(tSMP_CB *p_cb,
UNUSED_ATTR tSMP_INT_DATA *p_data)
{
SMP_TRACE_DEBUG ("%s", __func__);
p_cb->rand_enc_proc_state = SMP_GEN_SRAND_MRAND_CONT;
/* generate 64 MSB of MRand or SRand */
btsnd_hcic_ble_rand((void *)smp_rand_back);
}
/*******************************************************************************
**
** Function smp_generate_ltk
**
** Description This function is called:
** - in legacy pairing - to calculate LTK, starting with DIV
** generation;
** - in LE Secure Connections pairing over LE transport - to process LTK
** already generated to encrypt LE link;
** - in LE Secure Connections pairing over BR/EDR transport - to start
** BR/EDR Link Key processing.
**
** Returns void
**
*******************************************************************************/
void smp_generate_ltk(tSMP_CB *p_cb,
UNUSED_ATTR tSMP_INT_DATA *p_data)
{
bool div_status;
SMP_TRACE_DEBUG ("%s", __func__);
if (smp_get_br_state() == SMP_BR_STATE_BOND_PENDING)
{
smp_br_process_link_key(p_cb, NULL);
return;
}
else if (p_cb->le_secure_connections_mode_is_used)
{
smp_process_secure_connection_long_term_key();
return;
}
div_status = btm_get_local_div(p_cb->pairing_bda, &p_cb->div);
if (div_status)
{
smp_generate_ltk_cont(p_cb, NULL);
}
else
{
SMP_TRACE_DEBUG ("Generate DIV for LTK");
p_cb->rand_enc_proc_state = SMP_GEN_DIV_LTK;
/* generate MRand or SRand */
btsnd_hcic_ble_rand((void *)smp_rand_back);
}
}
/*******************************************************************************
**
** Function smp_compute_csrk
**
** Description This function is called to calculate CSRK
**
**
** Returns void
**
*******************************************************************************/
void smp_compute_csrk(tSMP_CB *p_cb,
UNUSED_ATTR tSMP_INT_DATA *p_data)
{
BT_OCTET16 er;
uint8_t buffer[4]; /* for (r || DIV) r=1*/
uint16_t r=1;
uint8_t *p=buffer;
tSMP_ENC output;
tSMP_STATUS status = SMP_PAIR_FAIL_UNKNOWN;
SMP_TRACE_DEBUG ("smp_compute_csrk div=%x", p_cb->div);
BTM_GetDeviceEncRoot(er);
/* CSRK = d1(ER, DIV, 1) */
UINT16_TO_STREAM(p, p_cb->div);
UINT16_TO_STREAM(p, r);
if (!SMP_Encrypt(er, BT_OCTET16_LEN, buffer, 4, &output))
{
SMP_TRACE_ERROR("smp_generate_csrk failed");
if (p_cb->smp_over_br)
{
smp_br_state_machine_event(p_cb, SMP_BR_AUTH_CMPL_EVT, &status);
}
else
{
smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &status);
}
}
else
{
memcpy((void *)p_cb->csrk, output.param_buf, BT_OCTET16_LEN);
smp_send_csrk_info(p_cb, NULL);
}
}
/*******************************************************************************
**
** Function smp_generate_csrk
**
** Description This function is called to calculate CSRK, starting with DIV
** generation.
**
**
** Returns void
**
*******************************************************************************/
void smp_generate_csrk(tSMP_CB *p_cb,
UNUSED_ATTR tSMP_INT_DATA *p_data)
{
bool div_status;
SMP_TRACE_DEBUG ("smp_generate_csrk");
div_status = btm_get_local_div(p_cb->pairing_bda, &p_cb->div);
if (div_status)
{
smp_compute_csrk(p_cb, NULL);
}
else
{
SMP_TRACE_DEBUG ("Generate DIV for CSRK");
p_cb->rand_enc_proc_state = SMP_GEN_DIV_CSRK;
btsnd_hcic_ble_rand((void *)smp_rand_back);
}
}
/*******************************************************************************
** Function smp_concatenate_peer
** add pairing command sent from local device into p1.
*******************************************************************************/
void smp_concatenate_local( tSMP_CB *p_cb, uint8_t **p_data, uint8_t op_code)
{
uint8_t *p = *p_data;
SMP_TRACE_DEBUG ("%s", __func__);
UINT8_TO_STREAM(p, op_code);
UINT8_TO_STREAM(p, p_cb->local_io_capability);
UINT8_TO_STREAM(p, p_cb->loc_oob_flag);
UINT8_TO_STREAM(p, p_cb->loc_auth_req);
UINT8_TO_STREAM(p, p_cb->loc_enc_size);
UINT8_TO_STREAM(p, p_cb->local_i_key);
UINT8_TO_STREAM(p, p_cb->local_r_key);
*p_data = p;
}
/*******************************************************************************
** Function smp_concatenate_peer
** add pairing command received from peer device into p1.
*******************************************************************************/
void smp_concatenate_peer( tSMP_CB *p_cb, uint8_t **p_data, uint8_t op_code)
{
uint8_t *p = *p_data;
SMP_TRACE_DEBUG ("smp_concatenate_peer ");
UINT8_TO_STREAM(p, op_code);
UINT8_TO_STREAM(p, p_cb->peer_io_caps);
UINT8_TO_STREAM(p, p_cb->peer_oob_flag);
UINT8_TO_STREAM(p, p_cb->peer_auth_req);
UINT8_TO_STREAM(p, p_cb->peer_enc_size);
UINT8_TO_STREAM(p, p_cb->peer_i_key);
UINT8_TO_STREAM(p, p_cb->peer_r_key);
*p_data = p;
}
/*******************************************************************************
**
** Function smp_gen_p1_4_confirm
**
** Description Generate Confirm/Compare Step1:
** p1 = pres || preq || rat' || iat'
**
** Returns void
**
*******************************************************************************/
void smp_gen_p1_4_confirm( tSMP_CB *p_cb, BT_OCTET16 p1)
{
uint8_t *p = (uint8_t *)p1;
tBLE_ADDR_TYPE addr_type = 0;
BD_ADDR remote_bda;
SMP_TRACE_DEBUG ("smp_gen_p1_4_confirm");
if (!BTM_ReadRemoteConnectionAddr(p_cb->pairing_bda, remote_bda, &addr_type))
{
SMP_TRACE_ERROR("can not generate confirm for unknown device");
return;
}
BTM_ReadConnectionAddr( p_cb->pairing_bda, p_cb->local_bda, &p_cb->addr_type);
if (p_cb->role == HCI_ROLE_MASTER)
{
/* LSB : rat': initiator's(local) address type */
UINT8_TO_STREAM(p, p_cb->addr_type);
/* LSB : iat': responder's address type */
UINT8_TO_STREAM(p, addr_type);
/* concatinate preq */
smp_concatenate_local(p_cb, &p, SMP_OPCODE_PAIRING_REQ);
/* concatinate pres */
smp_concatenate_peer(p_cb, &p, SMP_OPCODE_PAIRING_RSP);
}
else
{
/* LSB : iat': initiator's address type */
UINT8_TO_STREAM(p, addr_type);
/* LSB : rat': responder's(local) address type */
UINT8_TO_STREAM(p, p_cb->addr_type);
/* concatinate preq */
smp_concatenate_peer(p_cb, &p, SMP_OPCODE_PAIRING_REQ);
/* concatinate pres */
smp_concatenate_local(p_cb, &p, SMP_OPCODE_PAIRING_RSP);
}
#if (SMP_DEBUG == TRUE)
SMP_TRACE_DEBUG("p1 = pres || preq || rat' || iat'");
smp_debug_print_nbyte_little_endian ((uint8_t *)p1, (const uint8_t *)"P1", 16);
#endif
}
/*******************************************************************************
**
** Function smp_gen_p2_4_confirm
**
** Description Generate Confirm/Compare Step2:
** p2 = padding || ia || ra
**
** Returns void
**
*******************************************************************************/
void smp_gen_p2_4_confirm( tSMP_CB *p_cb, BT_OCTET16 p2)
{
uint8_t *p = (uint8_t *)p2;
BD_ADDR remote_bda;
tBLE_ADDR_TYPE addr_type = 0;
if (!BTM_ReadRemoteConnectionAddr(p_cb->pairing_bda, remote_bda, &addr_type))
{
SMP_TRACE_ERROR("can not generate confirm p2 for unknown device");
return;
}
SMP_TRACE_DEBUG ("smp_gen_p2_4_confirm");
memset(p, 0, sizeof(BT_OCTET16));
if (p_cb->role == HCI_ROLE_MASTER)
{
/* LSB ra */
BDADDR_TO_STREAM(p, remote_bda);
/* ia */
BDADDR_TO_STREAM(p, p_cb->local_bda);
}
else
{
/* LSB ra */
BDADDR_TO_STREAM(p, p_cb->local_bda);
/* ia */
BDADDR_TO_STREAM(p, remote_bda);
}
#if (SMP_DEBUG == TRUE)
SMP_TRACE_DEBUG("p2 = padding || ia || ra");
smp_debug_print_nbyte_little_endian(p2, (const uint8_t *)"p2", 16);
#endif
}
/*******************************************************************************
**
** Function smp_calculate_comfirm
**
** Description This function is called to calculate Confirm value.
**
** Returns void
**
*******************************************************************************/
void smp_calculate_comfirm (tSMP_CB *p_cb, BT_OCTET16 rand,
UNUSED_ATTR BD_ADDR bda)
{
BT_OCTET16 p1;
tSMP_ENC output;
tSMP_STATUS status = SMP_PAIR_FAIL_UNKNOWN;
SMP_TRACE_DEBUG ("smp_calculate_comfirm ");
/* generate p1 = pres || preq || rat' || iat' */
smp_gen_p1_4_confirm(p_cb, p1);
/* p1 = rand XOR p1 */
smp_xor_128(p1, rand);
smp_debug_print_nbyte_little_endian ((uint8_t *)p1, (const uint8_t *)"P1' = r XOR p1", 16);
/* calculate e(k, r XOR p1), where k = TK */
if (!SMP_Encrypt(p_cb->tk, BT_OCTET16_LEN, p1, BT_OCTET16_LEN, &output))
{
SMP_TRACE_ERROR("smp_generate_csrk failed");
smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &status);
}
else
{
smp_calculate_comfirm_cont(p_cb, &output);
}
}
/*******************************************************************************
**
** Function smp_calculate_comfirm_cont
**
** Description This function is called when SConfirm/MConfirm is generated
** proceed to send the Confirm request/response to peer device.
**
** Returns void
**
*******************************************************************************/
static void smp_calculate_comfirm_cont(tSMP_CB *p_cb, tSMP_ENC *p)
{
BT_OCTET16 p2;
tSMP_ENC output;
tSMP_STATUS status = SMP_PAIR_FAIL_UNKNOWN;
SMP_TRACE_DEBUG ("smp_calculate_comfirm_cont ");
#if (SMP_DEBUG == TRUE)
SMP_TRACE_DEBUG("Confirm step 1 p1' = e(k, r XOR p1) Generated");
smp_debug_print_nbyte_little_endian (p->param_buf, (const uint8_t *)"C1", 16);
#endif
smp_gen_p2_4_confirm(p_cb, p2);
/* calculate p2 = (p1' XOR p2) */
smp_xor_128(p2, p->param_buf);
smp_debug_print_nbyte_little_endian ((uint8_t *)p2, (const uint8_t *)"p2' = C1 xor p2", 16);
/* calculate: Confirm = E(k, p1' XOR p2) */
if (!SMP_Encrypt(p_cb->tk, BT_OCTET16_LEN, p2, BT_OCTET16_LEN, &output))
{
SMP_TRACE_ERROR("smp_calculate_comfirm_cont failed");
smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &status);
}
else
{
switch (p_cb->rand_enc_proc_state)
{
case SMP_GEN_CONFIRM:
smp_process_confirm(p_cb, &output);
break;
case SMP_GEN_COMPARE:
smp_process_compare(p_cb, &output);
break;
}
}
}
/*******************************************************************************
**
** Function smp_generate_confirm
**
** Description This function is called when a 48 bits random number is generated
** as SRand or MRand, continue to calculate Sconfirm or MConfirm.
**
** Returns void
**
*******************************************************************************/
static void smp_generate_confirm(tSMP_CB *p_cb,
UNUSED_ATTR tSMP_INT_DATA *p_data)
{
SMP_TRACE_DEBUG ("%s", __func__);
p_cb->rand_enc_proc_state = SMP_GEN_CONFIRM;
smp_debug_print_nbyte_little_endian ((uint8_t *)p_cb->rand, (const uint8_t *)"local rand", 16);
smp_calculate_comfirm(p_cb, p_cb->rand, p_cb->pairing_bda);
}
/*******************************************************************************
**
** Function smp_generate_compare
**
** Description This function is called to generate SConfirm for Slave device,
** or MSlave for Master device. This function can be also used for
** generating Compare number for confirm value check.
**
** Returns void
**
*******************************************************************************/
void smp_generate_compare (tSMP_CB *p_cb,
UNUSED_ATTR tSMP_INT_DATA *p_data)
{
SMP_TRACE_DEBUG ("smp_generate_compare ");
p_cb->rand_enc_proc_state = SMP_GEN_COMPARE;
smp_debug_print_nbyte_little_endian ((uint8_t *)p_cb->rrand, (const uint8_t *)"peer rand", 16);
smp_calculate_comfirm(p_cb, p_cb->rrand, p_cb->local_bda);
}
/*******************************************************************************
**
** Function smp_process_confirm
**
** Description This function is called when SConfirm/MConfirm is generated
** proceed to send the Confirm request/response to peer device.
**
** Returns void
**
*******************************************************************************/
static void smp_process_confirm(tSMP_CB *p_cb, tSMP_ENC *p)
{
tSMP_KEY key;
SMP_TRACE_DEBUG ("%s", __func__);
memcpy(p_cb->confirm, p->param_buf, BT_OCTET16_LEN);
#if (SMP_DEBUG == TRUE)
SMP_TRACE_DEBUG("Confirm Generated");
smp_debug_print_nbyte_little_endian ((uint8_t *)p_cb->confirm, (const uint8_t *)"Confirm", 16);
#endif
key.key_type = SMP_KEY_TYPE_CFM;
key.p_data = p->param_buf;
smp_sm_event(p_cb, SMP_KEY_READY_EVT, &key);
}
/*******************************************************************************
**
** Function smp_process_compare
**
** Description This function is called when Compare is generated using the
** RRand and local BDA, TK information.
**
** Returns void
**
*******************************************************************************/
static void smp_process_compare(tSMP_CB *p_cb, tSMP_ENC *p)
{
tSMP_KEY key;
SMP_TRACE_DEBUG ("smp_process_compare ");
#if (SMP_DEBUG == TRUE)
SMP_TRACE_DEBUG("Compare Generated");
smp_debug_print_nbyte_little_endian (p->param_buf, (const uint8_t *)"Compare", 16);
#endif
key.key_type = SMP_KEY_TYPE_CMP;
key.p_data = p->param_buf;
smp_sm_event(p_cb, SMP_KEY_READY_EVT, &key);
}
/*******************************************************************************
**
** Function smp_process_stk
**
** Description This function is called when STK is generated
** proceed to send the encrypt the link using STK.
**
** Returns void
**
*******************************************************************************/
static void smp_process_stk(tSMP_CB *p_cb, tSMP_ENC *p)
{
tSMP_KEY key;
SMP_TRACE_DEBUG ("smp_process_stk ");
#if (SMP_DEBUG == TRUE)
SMP_TRACE_ERROR("STK Generated");
#endif
smp_mask_enc_key(p_cb->loc_enc_size, p->param_buf);
key.key_type = SMP_KEY_TYPE_STK;
key.p_data = p->param_buf;
smp_sm_event(p_cb, SMP_KEY_READY_EVT, &key);
}
/*******************************************************************************
**
** Function smp_generate_ltk_cont
**
** Description This function is to calculate LTK = d1(ER, DIV, 0)= e(ER, DIV)
**
** Returns void
**
*******************************************************************************/
static void smp_generate_ltk_cont(tSMP_CB *p_cb,
UNUSED_ATTR tSMP_INT_DATA *p_data)
{
BT_OCTET16 er;
tSMP_ENC output;
tSMP_STATUS status = SMP_PAIR_FAIL_UNKNOWN;
SMP_TRACE_DEBUG ("%s", __func__);
BTM_GetDeviceEncRoot(er);
/* LTK = d1(ER, DIV, 0)= e(ER, DIV)*/
if (!SMP_Encrypt(er, BT_OCTET16_LEN, (uint8_t *)&p_cb->div,
sizeof(uint16_t), &output))
{
SMP_TRACE_ERROR("%s failed", __func__);
smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &status);
}
else
{
/* mask the LTK */
smp_mask_enc_key(p_cb->loc_enc_size, output.param_buf);
memcpy((void *)p_cb->ltk, output.param_buf, BT_OCTET16_LEN);
smp_generate_rand_vector(p_cb, NULL);
}
}
/*******************************************************************************
**
** Function smp_generate_y
**
** Description This function is to proceed generate Y = E(DHK, Rand)
**
** Returns void
**
*******************************************************************************/
static void smp_generate_y(tSMP_CB *p_cb,
UNUSED_ATTR tSMP_INT_DATA *p)
{
BT_OCTET16 dhk;
tSMP_ENC output;
tSMP_STATUS status = SMP_PAIR_FAIL_UNKNOWN;
SMP_TRACE_DEBUG ("smp_generate_y ");
BTM_GetDeviceDHK(dhk);
if (!SMP_Encrypt(dhk, BT_OCTET16_LEN, p_cb->enc_rand,
BT_OCTET8_LEN, &output))
{
SMP_TRACE_ERROR("smp_generate_y failed");
smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &status);
}
else
{
smp_process_ediv(p_cb, &output);
}
}
/*******************************************************************************
**
** Function smp_generate_rand_vector
**
** Description This function is called when LTK is generated, send state machine
** event to SMP.
**
** Returns void
**
*******************************************************************************/
static void smp_generate_rand_vector (tSMP_CB *p_cb,
UNUSED_ATTR tSMP_INT_DATA *p)
{
/* generate EDIV and rand now */
/* generate random vector */
SMP_TRACE_DEBUG ("smp_generate_rand_vector ");
p_cb->rand_enc_proc_state = SMP_GEN_RAND_V;
btsnd_hcic_ble_rand((void *)smp_rand_back);
}
/*******************************************************************************
**
** Function smp_process_ediv
**
** Description This function is to calculate EDIV = Y xor DIV
**
** Returns void
**
*******************************************************************************/
static void smp_process_ediv(tSMP_CB *p_cb, tSMP_ENC *p)
{
tSMP_KEY key;
uint8_t *pp= p->param_buf;
uint16_t y;
SMP_TRACE_DEBUG ("smp_process_ediv ");
STREAM_TO_UINT16(y, pp);
/* EDIV = Y xor DIV */
p_cb->ediv = p_cb->div ^ y;
/* send LTK ready */
SMP_TRACE_ERROR("LTK ready");
key.key_type = SMP_KEY_TYPE_LTK;
key.p_data = p->param_buf;
smp_sm_event(p_cb, SMP_KEY_READY_EVT, &key);
}
/*******************************************************************************
**
** Function smp_calculate_legacy_short_term_key
**
** Description The function calculates legacy STK.
**
** Returns false if out of resources, true in other cases.
**
*******************************************************************************/
bool smp_calculate_legacy_short_term_key(tSMP_CB *p_cb, tSMP_ENC *output)
{
BT_OCTET16 ptext;
uint8_t *p = ptext;
SMP_TRACE_DEBUG ("%s", __func__);
memset(p, 0, BT_OCTET16_LEN);
if (p_cb->role == HCI_ROLE_MASTER)
{
memcpy(p, p_cb->rand, BT_OCTET8_LEN);
memcpy(&p[BT_OCTET8_LEN], p_cb->rrand, BT_OCTET8_LEN);
}
else
{
memcpy(p, p_cb->rrand, BT_OCTET8_LEN);
memcpy(&p[BT_OCTET8_LEN], p_cb->rand, BT_OCTET8_LEN);
}
bool encrypted;
/* generate STK = Etk(rand|rrand)*/
encrypted = SMP_Encrypt( p_cb->tk, BT_OCTET16_LEN, ptext, BT_OCTET16_LEN, output);
if (!encrypted)
{
SMP_TRACE_ERROR("%s failed", __func__);
}
return encrypted;
}
/*******************************************************************************
**
** Function smp_create_private_key
**
** Description This function is called to create private key used to
** calculate public key and DHKey.
** The function starts private key creation requesting controller
** to generate [0-7] octets of private key.
**
** Returns void
**
*******************************************************************************/
void smp_create_private_key(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
{
SMP_TRACE_DEBUG ("%s",__func__);
p_cb->rand_enc_proc_state = SMP_GENERATE_PRIVATE_KEY_0_7;
btsnd_hcic_ble_rand((void *)smp_rand_back);
}
/*******************************************************************************
**
** Function smp_use_oob_private_key
**
** Description This function is called
** - to save the secret key used to calculate the public key used
** in calculations of commitment sent OOB to a peer
** - to use this secret key to recalculate the public key and
** start the process of sending this public key to the peer
** if secret/public keys have to be reused.
** If the keys aren't supposed to be reused, continue from the
** point from which request for OOB data was issued.
**
** Returns void
**
*******************************************************************************/
void smp_use_oob_private_key(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
{
SMP_TRACE_DEBUG ("%s req_oob_type: %d, role: %d",
__func__, p_cb->req_oob_type, p_cb->role);
switch (p_cb->req_oob_type)
{
case SMP_OOB_BOTH:
case SMP_OOB_LOCAL:
SMP_TRACE_DEBUG("%s restore secret key", __func__)
memcpy(p_cb->private_key, p_cb->sc_oob_data.loc_oob_data.private_key_used, BT_OCTET32_LEN);
smp_process_private_key(p_cb);
break;
default:
SMP_TRACE_DEBUG("%s create secret key anew", __func__);
smp_set_state(SMP_STATE_PAIR_REQ_RSP);
smp_decide_association_model(p_cb, NULL);
break;
}
}
/*******************************************************************************
**
** Function smp_continue_private_key_creation
**
** Description This function is used to continue private key creation.
**
** Returns void
**
*******************************************************************************/
void smp_continue_private_key_creation (tSMP_CB *p_cb, tBTM_RAND_ENC *p)
{
uint8_t state = p_cb->rand_enc_proc_state & ~0x80;
SMP_TRACE_DEBUG ("%s state=0x%x", __func__, state);
switch (state)
{
case SMP_GENERATE_PRIVATE_KEY_0_7:
memcpy((void *)p_cb->private_key, p->param_buf, p->param_len);
p_cb->rand_enc_proc_state = SMP_GENERATE_PRIVATE_KEY_8_15;
btsnd_hcic_ble_rand((void *)smp_rand_back);
break;
case SMP_GENERATE_PRIVATE_KEY_8_15:
memcpy((void *)&p_cb->private_key[8], p->param_buf, p->param_len);
p_cb->rand_enc_proc_state = SMP_GENERATE_PRIVATE_KEY_16_23;
btsnd_hcic_ble_rand((void *)smp_rand_back);
break;
case SMP_GENERATE_PRIVATE_KEY_16_23:
memcpy((void *)&p_cb->private_key[16], p->param_buf, p->param_len);
p_cb->rand_enc_proc_state = SMP_GENERATE_PRIVATE_KEY_24_31;
btsnd_hcic_ble_rand((void *)smp_rand_back);
break;
case SMP_GENERATE_PRIVATE_KEY_24_31:
memcpy((void *)&p_cb->private_key[24], p->param_buf, p->param_len);
smp_process_private_key (p_cb);
break;
default:
break;
}
return;
}
/*******************************************************************************
**
** Function smp_process_private_key
**
** Description This function processes private key.
** It calculates public key and notifies SM that private key /
** public key pair is created.
**
** Returns void
**
*******************************************************************************/
void smp_process_private_key(tSMP_CB *p_cb)
{
Point public_key;
BT_OCTET32 private_key;
SMP_TRACE_DEBUG ("%s", __func__);
memcpy(private_key, p_cb->private_key, BT_OCTET32_LEN);
ECC_PointMult(&public_key, &(curve_p256.G), (uint32_t*) private_key, KEY_LENGTH_DWORDS_P256);
memcpy(p_cb->loc_publ_key.x, public_key.x, BT_OCTET32_LEN);
memcpy(p_cb->loc_publ_key.y, public_key.y, BT_OCTET32_LEN);
smp_debug_print_nbyte_little_endian (p_cb->private_key, (const uint8_t *)"private",
BT_OCTET32_LEN);
smp_debug_print_nbyte_little_endian (p_cb->loc_publ_key.x, (const uint8_t *)"local public(x)",
BT_OCTET32_LEN);
smp_debug_print_nbyte_little_endian (p_cb->loc_publ_key.y, (const uint8_t *)"local public(y)",
BT_OCTET32_LEN);
p_cb->flags |= SMP_PAIR_FLAG_HAVE_LOCAL_PUBL_KEY;
smp_sm_event(p_cb, SMP_LOC_PUBL_KEY_CRTD_EVT, NULL);
}
/*******************************************************************************
**
** Function smp_compute_dhkey
**
** Description The function:
** - calculates a new public key using as input local private
** key and peer public key;
** - saves the new public key x-coordinate as DHKey.
**
** Returns void
**
*******************************************************************************/
void smp_compute_dhkey (tSMP_CB *p_cb)
{
Point peer_publ_key, new_publ_key;
BT_OCTET32 private_key;
SMP_TRACE_DEBUG ("%s", __func__);
memcpy(private_key, p_cb->private_key, BT_OCTET32_LEN);
memcpy(peer_publ_key.x, p_cb->peer_publ_key.x, BT_OCTET32_LEN);
memcpy(peer_publ_key.y, p_cb->peer_publ_key.y, BT_OCTET32_LEN);
ECC_PointMult(&new_publ_key, &peer_publ_key, (uint32_t*) private_key, KEY_LENGTH_DWORDS_P256);
memcpy(p_cb->dhkey, new_publ_key.x, BT_OCTET32_LEN);
smp_debug_print_nbyte_little_endian (p_cb->dhkey, (const uint8_t *)"Old DHKey",
BT_OCTET32_LEN);
smp_debug_print_nbyte_little_endian (p_cb->private_key, (const uint8_t *)"private",
BT_OCTET32_LEN);
smp_debug_print_nbyte_little_endian (p_cb->peer_publ_key.x, (const uint8_t *)"rem public(x)",
BT_OCTET32_LEN);
smp_debug_print_nbyte_little_endian (p_cb->peer_publ_key.y, (const uint8_t *)"rem public(y)",
BT_OCTET32_LEN);
smp_debug_print_nbyte_little_endian (p_cb->dhkey, (const uint8_t *)"Reverted DHKey",
BT_OCTET32_LEN);
}
/*******************************************************************************
**
** Function smp_calculate_local_commitment
**
** Description The function calculates and saves local commmitment in CB.
**
** Returns void
**
*******************************************************************************/
void smp_calculate_local_commitment(tSMP_CB *p_cb)
{
uint8_t random_input;
SMP_TRACE_DEBUG("%s", __func__);
switch (p_cb->selected_association_model)
{
case SMP_MODEL_SEC_CONN_JUSTWORKS:
case SMP_MODEL_SEC_CONN_NUM_COMP:
if (p_cb->role == HCI_ROLE_MASTER)
SMP_TRACE_WARNING ("local commitment calc on master is not expected \
for Just Works/Numeric Comparison models");
smp_calculate_f4(p_cb->loc_publ_key.x, p_cb->peer_publ_key.x, p_cb->rand, 0,
p_cb->commitment);
break;
case SMP_MODEL_SEC_CONN_PASSKEY_ENT:
case SMP_MODEL_SEC_CONN_PASSKEY_DISP:
random_input = smp_calculate_random_input(p_cb->local_random, p_cb->round);
smp_calculate_f4(p_cb->loc_publ_key.x, p_cb->peer_publ_key.x, p_cb->rand,
random_input, p_cb->commitment);
break;
case SMP_MODEL_SEC_CONN_OOB:
SMP_TRACE_WARNING ("local commitment calc is expected for OOB model BEFORE pairing");
smp_calculate_f4(p_cb->loc_publ_key.x, p_cb->loc_publ_key.x, p_cb->local_random, 0,
p_cb->commitment);
break;
default:
SMP_TRACE_ERROR("Association Model = %d is not used in LE SC",
p_cb->selected_association_model);
return;
}
SMP_TRACE_EVENT ("local commitment calculation is completed");
}
/*******************************************************************************
**
** Function smp_calculate_peer_commitment
**
** Description The function calculates and saves peer commmitment at the
** provided output buffer.
**
** Returns void
**
*******************************************************************************/
void smp_calculate_peer_commitment(tSMP_CB *p_cb, BT_OCTET16 output_buf)
{
uint8_t ri;
SMP_TRACE_DEBUG ("%s", __func__);
switch (p_cb->selected_association_model)
{
case SMP_MODEL_SEC_CONN_JUSTWORKS:
case SMP_MODEL_SEC_CONN_NUM_COMP:
if (p_cb->role == HCI_ROLE_SLAVE)
SMP_TRACE_WARNING ("peer commitment calc on slave is not expected \
for Just Works/Numeric Comparison models");
smp_calculate_f4(p_cb->peer_publ_key.x, p_cb->loc_publ_key.x, p_cb->rrand, 0,
output_buf);
break;
case SMP_MODEL_SEC_CONN_PASSKEY_ENT:
case SMP_MODEL_SEC_CONN_PASSKEY_DISP:
ri = smp_calculate_random_input(p_cb->peer_random, p_cb->round);
smp_calculate_f4(p_cb->peer_publ_key.x, p_cb->loc_publ_key.x, p_cb->rrand, ri,
output_buf);
break;
case SMP_MODEL_SEC_CONN_OOB:
smp_calculate_f4(p_cb->peer_publ_key.x, p_cb->peer_publ_key.x, p_cb->peer_random, 0,
output_buf);
break;
default:
SMP_TRACE_ERROR("Association Model = %d is not used in LE SC",
p_cb->selected_association_model);
return;
}
SMP_TRACE_EVENT ("peer commitment calculation is completed");
}
/*******************************************************************************
**
** Function smp_calculate_f4
**
** Description The function calculates
** C = f4(U, V, X, Z) = AES-CMAC (U||V||Z)
** X
** where
** input: U is 256 bit,
** V is 256 bit,
** X is 128 bit,
** Z is 8 bit,
** output: C is 128 bit.
**
** Returns void
**
** Note The LSB is the first octet, the MSB is the last octet of
** the AES-CMAC input/output stream.
**
*******************************************************************************/
void smp_calculate_f4(uint8_t *u, uint8_t *v, uint8_t *x, uint8_t z, uint8_t *c)
{
uint8_t msg_len = BT_OCTET32_LEN /* U size */ + BT_OCTET32_LEN /* V size */ + 1 /* Z size */;
uint8_t msg[BT_OCTET32_LEN + BT_OCTET32_LEN + 1];
uint8_t key[BT_OCTET16_LEN];
uint8_t cmac[BT_OCTET16_LEN];
uint8_t *p = NULL;
#if (SMP_DEBUG == TRUE)
uint8_t *p_prnt = NULL;
#endif
SMP_TRACE_DEBUG ("%s", __func__);
#if (SMP_DEBUG == TRUE)
p_prnt = u;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"U", BT_OCTET32_LEN);
p_prnt = v;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"V", BT_OCTET32_LEN);
p_prnt = x;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"X", BT_OCTET16_LEN);
p_prnt = &z;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"Z", 1);
#endif
p = msg;
UINT8_TO_STREAM(p, z);
ARRAY_TO_STREAM(p, v, BT_OCTET32_LEN);
ARRAY_TO_STREAM(p, u, BT_OCTET32_LEN);
#if (SMP_DEBUG == TRUE)
p_prnt = msg;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"M", msg_len);
#endif
p = key;
ARRAY_TO_STREAM(p, x, BT_OCTET16_LEN);
#if (SMP_DEBUG == TRUE)
p_prnt = key;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"K", BT_OCTET16_LEN);
#endif
aes_cipher_msg_auth_code(key, msg, msg_len, BT_OCTET16_LEN, cmac);
#if (SMP_DEBUG == TRUE)
p_prnt = cmac;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"AES_CMAC", BT_OCTET16_LEN);
#endif
p = c;
ARRAY_TO_STREAM(p, cmac, BT_OCTET16_LEN);
}
/*******************************************************************************
**
** Function smp_calculate_numeric_comparison_display_number
**
** Description The function calculates and saves number to display in numeric
** comparison association mode.
**
** Returns void
**
*******************************************************************************/
void smp_calculate_numeric_comparison_display_number(tSMP_CB *p_cb,
tSMP_INT_DATA *p_data)
{
SMP_TRACE_DEBUG ("%s", __func__);
if (p_cb->role == HCI_ROLE_MASTER)
{
p_cb->number_to_display =
smp_calculate_g2(p_cb->loc_publ_key.x, p_cb->peer_publ_key.x, p_cb->rand,
p_cb->rrand);
}
else
{
p_cb->number_to_display =
smp_calculate_g2(p_cb->peer_publ_key.x, p_cb->loc_publ_key.x, p_cb->rrand,
p_cb->rand);
}
if (p_cb->number_to_display >= (BTM_MAX_PASSKEY_VAL + 1))
{
uint8_t reason;
reason = p_cb->failure = SMP_PAIR_FAIL_UNKNOWN;
smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &reason);
return;
}
SMP_TRACE_EVENT("Number to display in numeric comparison = %d", p_cb->number_to_display);
p_cb->cb_evt = SMP_NC_REQ_EVT;
smp_sm_event(p_cb, SMP_SC_DSPL_NC_EVT, &p_cb->number_to_display);
return;
}
/*******************************************************************************
**
** Function smp_calculate_g2
**
** Description The function calculates
** g2(U, V, X, Y) = AES-CMAC (U||V||Y) mod 2**32 mod 10**6
** X
** and
** Vres = g2(U, V, X, Y) mod 10**6
** where
** input: U is 256 bit,
** V is 256 bit,
** X is 128 bit,
** Y is 128 bit,
**
** Returns Vres.
** Expected value has to be in the range [0 - 999999] i.e. [0 - 0xF423F].
** Vres = 1000000 means that the calculation fails.
**
** Note The LSB is the first octet, the MSB is the last octet of
** the AES-CMAC input/output stream.
**
*******************************************************************************/
uint32_t smp_calculate_g2(uint8_t *u, uint8_t *v, uint8_t *x, uint8_t *y)
{
uint8_t msg_len = BT_OCTET32_LEN /* U size */ + BT_OCTET32_LEN /* V size */
+ BT_OCTET16_LEN /* Y size */;
uint8_t msg[BT_OCTET32_LEN + BT_OCTET32_LEN + BT_OCTET16_LEN];
uint8_t key[BT_OCTET16_LEN];
uint8_t cmac[BT_OCTET16_LEN];
uint8_t *p = NULL;
uint32_t vres;
#if (SMP_DEBUG == TRUE)
uint8_t *p_prnt = NULL;
#endif
SMP_TRACE_DEBUG ("%s", __func__);
p = msg;
ARRAY_TO_STREAM(p, y, BT_OCTET16_LEN);
ARRAY_TO_STREAM(p, v, BT_OCTET32_LEN);
ARRAY_TO_STREAM(p, u, BT_OCTET32_LEN);
#if (SMP_DEBUG == TRUE)
p_prnt = u;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"U", BT_OCTET32_LEN);
p_prnt = v;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"V", BT_OCTET32_LEN);
p_prnt = x;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"X", BT_OCTET16_LEN);
p_prnt = y;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"Y", BT_OCTET16_LEN);
#endif
p = key;
ARRAY_TO_STREAM(p, x, BT_OCTET16_LEN);
#if (SMP_DEBUG == TRUE)
p_prnt = key;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"K", BT_OCTET16_LEN);
#endif
if(!aes_cipher_msg_auth_code(key, msg, msg_len, BT_OCTET16_LEN, cmac))
{
SMP_TRACE_ERROR("%s failed",__func__);
return (BTM_MAX_PASSKEY_VAL + 1);
}
#if (SMP_DEBUG == TRUE)
p_prnt = cmac;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"AES-CMAC", BT_OCTET16_LEN);
#endif
/* vres = cmac mod 2**32 mod 10**6 */
p = &cmac[0];
STREAM_TO_UINT32(vres, p);
#if (SMP_DEBUG == TRUE)
p_prnt = (uint8_t *) &vres;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"cmac mod 2**32", 4);
#endif
while (vres > BTM_MAX_PASSKEY_VAL)
vres -= (BTM_MAX_PASSKEY_VAL + 1);
#if (SMP_DEBUG == TRUE)
p_prnt = (uint8_t *) &vres;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"cmac mod 2**32 mod 10**6", 4);
#endif
SMP_TRACE_ERROR("Value for numeric comparison = %d", vres);
return vres;
}
/*******************************************************************************
**
** Function smp_calculate_f5
**
** Description The function provides two AES-CMAC that are supposed to be used as
** - MacKey (MacKey is used in pairing DHKey check calculation);
** - LTK (LTK is used to ecrypt the link after completion of Phase 2
** and on reconnection, to derive BR/EDR LK).
** The function inputs are W, N1, N2, A1, A2.
** F5 rules:
** - the value used as key in MacKey/LTK (T) is calculated
** (function smp_calculate_f5_key(...));
** The formula is:
** T = AES-CMAC (W)
** salt
** where salt is internal parameter of smp_calculate_f5_key(...).
** - MacKey and LTK are calculated as AES-MAC values received with the
** key T calculated in the previous step and the plaintext message
** built from the external parameters N1, N2, A1, A2 and the internal
** parameters counter, keyID, length.
** The function smp_calculate_f5_mackey_or_long_term_key(...) is used in the
** calculations.
** The same formula is used in calculation of MacKey and LTK and the
** same parameter values except the value of the internal parameter
** counter:
** - in MacKey calculations the value is 0;
** - in LTK calculations the value is 1.
** MacKey = AES-CMAC (Counter=0||keyID||N1||N2||A1||A2||Length=256)
** T
** LTK = AES-CMAC (Counter=1||keyID||N1||N2||A1||A2||Length=256)
** T
** The parameters are
** input:
** W is 256 bits,
** N1 is 128 bits,
** N2 is 128 bits,
** A1 is 56 bit,
** A2 is 56 bit.
** internal:
** Counter is 8 bits, its value is 0 for MacKey,
** 1 for LTK;
** KeyId is 32 bits, its value is
** 0x62746c65 (MSB~LSB);
** Length is 16 bits, its value is 0x0100
** (MSB~LSB).
** output:
** MacKey is 128 bits;
** LTK is 128 bits
**
** Returns false if out of resources, true in other cases.
**
** Note The LSB is the first octet, the MSB is the last octet of
** the AES-CMAC input/output stream.
**
*******************************************************************************/
bool smp_calculate_f5(uint8_t *w, uint8_t *n1, uint8_t *n2, uint8_t *a1, uint8_t *a2,
uint8_t *mac_key, uint8_t *ltk)
{
BT_OCTET16 t; /* AES-CMAC output in smp_calculate_f5_key(...), key in */
/* smp_calculate_f5_mackey_or_long_term_key(...) */
#if (SMP_DEBUG == TRUE)
uint8_t *p_prnt = NULL;
#endif
/* internal parameters: */
/*
counter is 0 for MacKey,
is 1 for LTK
*/
uint8_t counter_mac_key[1] = {0};
uint8_t counter_ltk[1] = {1};
/*
keyID 62746c65
*/
uint8_t key_id[4] = {0x65, 0x6c, 0x74, 0x62};
/*
length 0100
*/
uint8_t length[2] = {0x00, 0x01};
SMP_TRACE_DEBUG ("%s", __func__);
#if (SMP_DEBUG == TRUE)
p_prnt = w;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"W", BT_OCTET32_LEN);
p_prnt = n1;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"N1", BT_OCTET16_LEN);
p_prnt = n2;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"N2", BT_OCTET16_LEN);
p_prnt = a1;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"A1", 7);
p_prnt = a2;
smp_debug_print_nbyte_little_endian (p_prnt,(const uint8_t *) "A2", 7);
#endif
if (!smp_calculate_f5_key(w, t))
{
SMP_TRACE_ERROR("%s failed to calc T",__func__);
return false;
}
#if (SMP_DEBUG == TRUE)
p_prnt = t;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"T", BT_OCTET16_LEN);
#endif
if (!smp_calculate_f5_mackey_or_long_term_key(t, counter_mac_key, key_id, n1, n2, a1, a2,
length, mac_key))
{
SMP_TRACE_ERROR("%s failed to calc MacKey", __func__);
return false;
}
#if (SMP_DEBUG == TRUE)
p_prnt = mac_key;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"MacKey", BT_OCTET16_LEN);
#endif
if (!smp_calculate_f5_mackey_or_long_term_key(t, counter_ltk, key_id, n1, n2, a1, a2,
length, ltk))
{
SMP_TRACE_ERROR("%s failed to calc LTK",__func__);
return false;
}
#if (SMP_DEBUG == TRUE)
p_prnt = ltk;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"LTK", BT_OCTET16_LEN);
#endif
return true;
}
/*******************************************************************************
**
** Function smp_calculate_f5_mackey_or_long_term_key
**
** Description The function calculates the value of MacKey or LTK by the rules
** defined for f5 function.
** At the moment exactly the same formula is used to calculate
** LTK and MacKey.
** The difference is the value of input parameter Counter:
** - in MacKey calculations the value is 0;
** - in LTK calculations the value is 1.
** The formula:
** mac = AES-CMAC (Counter||keyID||N1||N2||A1||A2||Length)
** T
** where
** input: T is 256 bits;
** Counter is 8 bits, its value is 0 for MacKey,
** 1 for LTK;
** keyID is 32 bits, its value is 0x62746c65;
** N1 is 128 bits;
** N2 is 128 bits;
** A1 is 56 bits;
** A2 is 56 bits;
** Length is 16 bits, its value is 0x0100
** output: LTK is 128 bit.
**
** Returns false if out of resources, true in other cases.
**
** Note The LSB is the first octet, the MSB is the last octet of
** the AES-CMAC input/output stream.
**
*******************************************************************************/
bool smp_calculate_f5_mackey_or_long_term_key(uint8_t *t, uint8_t *counter,
uint8_t *key_id, uint8_t *n1, uint8_t *n2, uint8_t *a1, uint8_t *a2,
uint8_t *length, uint8_t *mac)
{
uint8_t *p = NULL;
uint8_t cmac[BT_OCTET16_LEN];
uint8_t key[BT_OCTET16_LEN];
uint8_t msg_len = 1 /* Counter size */ + 4 /* keyID size */ +
BT_OCTET16_LEN /* N1 size */ + BT_OCTET16_LEN /* N2 size */ +
7 /* A1 size*/ + 7 /* A2 size*/ + 2 /* Length size */;
uint8_t msg[1 + 4 + BT_OCTET16_LEN + BT_OCTET16_LEN + 7 + 7 + 2];
bool ret = true;
#if (SMP_DEBUG == TRUE)
uint8_t *p_prnt = NULL;
#endif
SMP_TRACE_DEBUG ("%s", __func__);
#if (SMP_DEBUG == TRUE)
p_prnt = t;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"T", BT_OCTET16_LEN);
p_prnt = counter;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"Counter", 1);
p_prnt = key_id;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"KeyID", 4);
p_prnt = n1;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"N1", BT_OCTET16_LEN);
p_prnt = n2;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"N2", BT_OCTET16_LEN);
p_prnt = a1;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"A1", 7);
p_prnt = a2;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"A2", 7);
p_prnt = length;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"Length", 2);
#endif
p = key;
ARRAY_TO_STREAM(p, t, BT_OCTET16_LEN);
#if (SMP_DEBUG == TRUE)
p_prnt = key;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"K", BT_OCTET16_LEN);
#endif
p = msg;
ARRAY_TO_STREAM(p, length, 2);
ARRAY_TO_STREAM(p, a2, 7);
ARRAY_TO_STREAM(p, a1, 7);
ARRAY_TO_STREAM(p, n2, BT_OCTET16_LEN);
ARRAY_TO_STREAM(p, n1, BT_OCTET16_LEN);
ARRAY_TO_STREAM(p, key_id, 4);
ARRAY_TO_STREAM(p, counter, 1);
#if (SMP_DEBUG == TRUE)
p_prnt = msg;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"M", msg_len);
#endif
if (!aes_cipher_msg_auth_code(key, msg, msg_len, BT_OCTET16_LEN, cmac))
{
SMP_TRACE_ERROR("%s failed", __func__);
ret = false;
}
#if (SMP_DEBUG == TRUE)
p_prnt = cmac;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"AES-CMAC", BT_OCTET16_LEN);
#endif
p = mac;
ARRAY_TO_STREAM(p, cmac, BT_OCTET16_LEN);
return ret;
}
/*******************************************************************************
**
** Function smp_calculate_f5_key
**
** Description The function calculates key T used in calculation of
** MacKey and LTK (f5 output is defined as MacKey || LTK).
** T = AES-CMAC (W)
** salt
** where
** Internal: salt is 128 bit.
** input: W is 256 bit.
** Output: T is 128 bit.
**
** Returns false if out of resources, true in other cases.
**
** Note The LSB is the first octet, the MSB is the last octet of
** the AES-CMAC input/output stream.
**
*******************************************************************************/
bool smp_calculate_f5_key(uint8_t *w, uint8_t *t)
{
uint8_t *p = NULL;
/* Please see 2.2.7 LE Secure Connections Key Generation Function f5 */
/*
salt: 6C88 8391 AAF5 A538 6037 0BDB 5A60 83BE
*/
BT_OCTET16 salt = {
0xBE, 0x83, 0x60, 0x5A, 0xDB, 0x0B, 0x37, 0x60,
0x38, 0xA5, 0xF5, 0xAA, 0x91, 0x83, 0x88, 0x6C
};
#if (SMP_DEBUG == TRUE)
uint8_t *p_prnt = NULL;
#endif
SMP_TRACE_DEBUG ("%s", __func__);
#if (SMP_DEBUG == TRUE)
p_prnt = salt;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"salt", BT_OCTET16_LEN);
p_prnt = w;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"W", BT_OCTET32_LEN);
#endif
BT_OCTET16 key;
BT_OCTET32 msg;
p = key;
ARRAY_TO_STREAM(p, salt, BT_OCTET16_LEN);
p = msg;
ARRAY_TO_STREAM(p, w, BT_OCTET32_LEN);
#if (SMP_DEBUG == TRUE)
p_prnt = key;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"K", BT_OCTET16_LEN);
p_prnt = msg;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"M", BT_OCTET32_LEN);
#endif
BT_OCTET16 cmac;
bool ret = true;
if (!aes_cipher_msg_auth_code(key, msg, BT_OCTET32_LEN, BT_OCTET16_LEN, cmac))
{
SMP_TRACE_ERROR("%s failed", __func__);
ret = false;
}
#if (SMP_DEBUG == TRUE)
p_prnt = cmac;
smp_debug_print_nbyte_little_endian (p_prnt, (const uint8_t *)"AES-CMAC", BT_OCTET16_LEN);
#endif
p = t;
ARRAY_TO_STREAM(p, cmac, BT_OCTET16_LEN);
return ret;
}
/*******************************************************************************
**
** Function smp_calculate_local_dhkey_check
**
** Description The function calculates and saves local device DHKey check
** value in CB.
** Before doing this it calls smp_calculate_f5_mackey_and_long_term_key(...).
** to calculate MacKey and LTK.
** MacKey is used in dhkey calculation.
**
** Returns void
**
*******************************************************************************/
void smp_calculate_local_dhkey_check(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
{
uint8_t iocap[3], a[7], b[7];
SMP_TRACE_DEBUG ("%s", __func__);
smp_calculate_f5_mackey_and_long_term_key(p_cb);
smp_collect_local_io_capabilities(iocap, p_cb);
smp_collect_local_ble_address(a, p_cb);
smp_collect_peer_ble_address(b, p_cb);
smp_calculate_f6(p_cb->mac_key, p_cb->rand, p_cb->rrand, p_cb->peer_random, iocap, a, b,
p_cb->dhkey_check);
SMP_TRACE_EVENT ("local DHKey check calculation is completed");
}
/*******************************************************************************
**
** Function smp_calculate_peer_dhkey_check
**
** Description The function calculates peer device DHKey check value.
**
** Returns void
**
*******************************************************************************/
void smp_calculate_peer_dhkey_check(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
{
uint8_t iocap[3], a[7], b[7];
BT_OCTET16 param_buf;
bool ret;
tSMP_KEY key;
tSMP_STATUS status = SMP_PAIR_FAIL_UNKNOWN;
SMP_TRACE_DEBUG ("%s", __func__);
smp_collect_peer_io_capabilities(iocap, p_cb);
smp_collect_local_ble_address(a, p_cb);
smp_collect_peer_ble_address(b, p_cb);
ret = smp_calculate_f6(p_cb->mac_key, p_cb->rrand, p_cb->rand, p_cb->local_random, iocap,
b, a, param_buf);
if (ret)
{
SMP_TRACE_EVENT ("peer DHKey check calculation is completed");
#if (SMP_DEBUG == TRUE)
smp_debug_print_nbyte_little_endian (param_buf, (const uint8_t *)"peer DHKey check",
BT_OCTET16_LEN);
#endif
key.key_type = SMP_KEY_TYPE_PEER_DHK_CHCK;
key.p_data = param_buf;
smp_sm_event(p_cb, SMP_SC_KEY_READY_EVT, &key);
}
else
{
SMP_TRACE_EVENT ("peer DHKey check calculation failed");
smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &status);
}
}
/*******************************************************************************
**
** Function smp_calculate_f6
**
** Description The function calculates
** C = f6(W, N1, N2, R, IOcap, A1, A2) = AES-CMAC (N1||N2||R||IOcap||A1||A2)
** W
** where
** input: W is 128 bit,
** N1 is 128 bit,
** N2 is 128 bit,
** R is 128 bit,
** IOcap is 24 bit,
** A1 is 56 bit,
** A2 is 56 bit,
** output: C is 128 bit.
**
** Returns false if out of resources, true in other cases.
**
** Note The LSB is the first octet, the MSB is the last octet of
** the AES-CMAC input/output stream.
**
*******************************************************************************/
bool smp_calculate_f6(uint8_t *w, uint8_t *n1, uint8_t *n2, uint8_t *r, uint8_t *iocap, uint8_t *a1,
uint8_t *a2, uint8_t *c)
{
uint8_t *p = NULL;
uint8_t msg_len = BT_OCTET16_LEN /* N1 size */ + BT_OCTET16_LEN /* N2 size */ +
BT_OCTET16_LEN /* R size */ + 3 /* IOcap size */ + 7 /* A1 size*/
+ 7 /* A2 size*/;
uint8_t msg[BT_OCTET16_LEN + BT_OCTET16_LEN + BT_OCTET16_LEN + 3 + 7 + 7];
#if (SMP_DEBUG == TRUE)
uint8_t *p_print = NULL;
#endif
SMP_TRACE_DEBUG ("%s", __func__);
#if (SMP_DEBUG == TRUE)
p_print = w;
smp_debug_print_nbyte_little_endian (p_print, (const uint8_t *)"W", BT_OCTET16_LEN);
p_print = n1;
smp_debug_print_nbyte_little_endian (p_print, (const uint8_t *)"N1", BT_OCTET16_LEN);
p_print = n2;
smp_debug_print_nbyte_little_endian (p_print, (const uint8_t *)"N2", BT_OCTET16_LEN);
p_print = r;
smp_debug_print_nbyte_little_endian (p_print, (const uint8_t *)"R", BT_OCTET16_LEN);
p_print = iocap;
smp_debug_print_nbyte_little_endian (p_print, (const uint8_t *)"IOcap", 3);
p_print = a1;
smp_debug_print_nbyte_little_endian (p_print, (const uint8_t *)"A1", 7);
p_print = a2;
smp_debug_print_nbyte_little_endian (p_print, (const uint8_t *)"A2", 7);
#endif
uint8_t cmac[BT_OCTET16_LEN];
uint8_t key[BT_OCTET16_LEN];
p = key;
ARRAY_TO_STREAM(p, w, BT_OCTET16_LEN);
#if (SMP_DEBUG == TRUE)
p_print = key;
smp_debug_print_nbyte_little_endian (p_print, (const uint8_t *)"K", BT_OCTET16_LEN);
#endif
p = msg;
ARRAY_TO_STREAM(p, a2, 7);
ARRAY_TO_STREAM(p, a1, 7);
ARRAY_TO_STREAM(p, iocap, 3);
ARRAY_TO_STREAM(p, r, BT_OCTET16_LEN);
ARRAY_TO_STREAM(p, n2, BT_OCTET16_LEN);
ARRAY_TO_STREAM(p, n1, BT_OCTET16_LEN);
#if (SMP_DEBUG == TRUE)
p_print = msg;
smp_debug_print_nbyte_little_endian (p_print, (const uint8_t *)"M", msg_len);
#endif
bool ret = true;
if(!aes_cipher_msg_auth_code(key, msg, msg_len, BT_OCTET16_LEN, cmac))
{
SMP_TRACE_ERROR("%s failed", __func__);
ret = false;
}
#if (SMP_DEBUG == TRUE)
p_print = cmac;
smp_debug_print_nbyte_little_endian (p_print, (const uint8_t *)"AES-CMAC", BT_OCTET16_LEN);
#endif
p = c;
ARRAY_TO_STREAM(p, cmac, BT_OCTET16_LEN);
return ret;
}
/*******************************************************************************
**
** Function smp_calculate_link_key_from_long_term_key
**
** Description The function calculates and saves BR/EDR link key derived from
** LE SC LTK.
**
** Returns false if out of resources, true in other cases.
**
*******************************************************************************/
bool smp_calculate_link_key_from_long_term_key(tSMP_CB *p_cb)
{
tBTM_SEC_DEV_REC *p_dev_rec;
BD_ADDR bda_for_lk;
tBLE_ADDR_TYPE conn_addr_type;
SMP_TRACE_DEBUG ("%s", __func__);
if (p_cb->id_addr_rcvd && p_cb->id_addr_type == BLE_ADDR_PUBLIC)
{
SMP_TRACE_DEBUG ("Use rcvd identity address as BD_ADDR of LK rcvd identity address");
memcpy(bda_for_lk, p_cb->id_addr, BD_ADDR_LEN);
}
else if ((BTM_ReadRemoteConnectionAddr(p_cb->pairing_bda, bda_for_lk, &conn_addr_type)) &&
conn_addr_type == BLE_ADDR_PUBLIC)
{
SMP_TRACE_DEBUG ("Use rcvd connection address as BD_ADDR of LK");
}
else
{
SMP_TRACE_WARNING ("Don't have peer public address to associate with LK");
return false;
}
if ((p_dev_rec = btm_find_dev (p_cb->pairing_bda)) == NULL)
{
SMP_TRACE_ERROR("%s failed to find Security Record", __func__);
return false;
}
BT_OCTET16 intermediate_link_key;
bool ret = true;
ret = smp_calculate_h6(p_cb->ltk, (uint8_t *)"1pmt" /* reversed "tmp1" */,intermediate_link_key);
if (!ret)
{
SMP_TRACE_ERROR("%s failed to derive intermediate_link_key", __func__);
return ret;
}
BT_OCTET16 link_key;
ret = smp_calculate_h6(intermediate_link_key, (uint8_t *) "rbel" /* reversed "lebr" */, link_key);
if (!ret)
{
SMP_TRACE_ERROR("%s failed", __func__);
}
else
{
uint8_t link_key_type;
if (btm_cb.security_mode == BTM_SEC_MODE_SC)
{
/* Secure Connections Only Mode */
link_key_type = BTM_LKEY_TYPE_AUTH_COMB_P_256;
}
else if (controller_get_interface()->supports_secure_connections())
{
/* both transports are SC capable */
if (p_cb->sec_level == SMP_SEC_AUTHENTICATED)
link_key_type = BTM_LKEY_TYPE_AUTH_COMB_P_256;
else
link_key_type = BTM_LKEY_TYPE_UNAUTH_COMB_P_256;
}
else if (btm_cb.security_mode == BTM_SEC_MODE_SP)
{
/* BR/EDR transport is SSP capable */
if (p_cb->sec_level == SMP_SEC_AUTHENTICATED)
link_key_type = BTM_LKEY_TYPE_AUTH_COMB;
else
link_key_type = BTM_LKEY_TYPE_UNAUTH_COMB;
}
else
{
SMP_TRACE_ERROR ("%s failed to update link_key. Sec Mode = %d, sm4 = 0x%02x",
__func__, btm_cb.security_mode, p_dev_rec->sm4);
return false;
}
link_key_type += BTM_LTK_DERIVED_LKEY_OFFSET;
uint8_t *p;
BT_OCTET16 notif_link_key;
p = notif_link_key;
ARRAY16_TO_STREAM(p, link_key);
btm_sec_link_key_notification (bda_for_lk, notif_link_key, link_key_type);
SMP_TRACE_EVENT ("%s is completed", __func__);
}
return ret;
}
/*******************************************************************************
**
** Function smp_calculate_long_term_key_from_link_key
**
** Description The function calculates and saves SC LTK derived from BR/EDR
** link key.
**
** Returns false if out of resources, true in other cases.
**
*******************************************************************************/
bool smp_calculate_long_term_key_from_link_key(tSMP_CB *p_cb)
{
bool ret = true;
tBTM_SEC_DEV_REC *p_dev_rec;
uint8_t rev_link_key[16];
SMP_TRACE_DEBUG ("%s", __func__);
if ((p_dev_rec = btm_find_dev (p_cb->pairing_bda)) == NULL)
{
SMP_TRACE_ERROR("%s failed to find Security Record",__func__);
return false;
}
uint8_t br_link_key_type;
if ((br_link_key_type = BTM_SecGetDeviceLinkKeyType (p_cb->pairing_bda))
== BTM_LKEY_TYPE_IGNORE)
{
SMP_TRACE_ERROR("%s failed to retrieve BR link type",__func__);
return false;
}
if ((br_link_key_type != BTM_LKEY_TYPE_AUTH_COMB_P_256) &&
(br_link_key_type != BTM_LKEY_TYPE_UNAUTH_COMB_P_256))
{
SMP_TRACE_ERROR("%s LE SC LTK can't be derived from LK %d",
__func__, br_link_key_type);
return false;
}
uint8_t *p1;
uint8_t *p2;
p1 = rev_link_key;
p2 = p_dev_rec->link_key;
REVERSE_ARRAY_TO_STREAM(p1, p2, 16);
BT_OCTET16 intermediate_long_term_key;
/* "tmp2" obtained from the spec */
ret = smp_calculate_h6(rev_link_key, (uint8_t *) "2pmt" /* reversed "tmp2" */,
intermediate_long_term_key);
if (!ret)
{
SMP_TRACE_ERROR("%s failed to derive intermediate_long_term_key",__func__);
return ret;
}
/* "brle" obtained from the spec */
ret = smp_calculate_h6(intermediate_long_term_key, (uint8_t *) "elrb" /* reversed "brle" */,
p_cb->ltk);
if (!ret)
{
SMP_TRACE_ERROR("%s failed",__func__);
}
else
{
p_cb->sec_level = (br_link_key_type == BTM_LKEY_TYPE_AUTH_COMB_P_256)
? SMP_SEC_AUTHENTICATED : SMP_SEC_UNAUTHENTICATE;
SMP_TRACE_EVENT ("%s is completed",__func__);
}
return ret;
}
/*******************************************************************************
**
** Function smp_calculate_h6
**
** Description The function calculates
** C = h6(W, KeyID) = AES-CMAC (KeyID)
** W
** where
** input: W is 128 bit,
** KeyId is 32 bit,
** output: C is 128 bit.
**
** Returns false if out of resources, true in other cases.
**
** Note The LSB is the first octet, the MSB is the last octet of
** the AES-CMAC input/output stream.
**
*******************************************************************************/
bool smp_calculate_h6(uint8_t *w, uint8_t *keyid, uint8_t *c)
{
#if (SMP_DEBUG == TRUE)
uint8_t *p_print = NULL;
#endif
SMP_TRACE_DEBUG ("%s",__func__);
#if (SMP_DEBUG == TRUE)
p_print = w;
smp_debug_print_nbyte_little_endian (p_print, (const uint8_t *)"W", BT_OCTET16_LEN);
p_print = keyid;
smp_debug_print_nbyte_little_endian (p_print, (const uint8_t *)"keyID", 4);
#endif
uint8_t *p = NULL;
uint8_t key[BT_OCTET16_LEN];
p = key;
ARRAY_TO_STREAM(p, w, BT_OCTET16_LEN);
#if (SMP_DEBUG == TRUE)
p_print = key;
smp_debug_print_nbyte_little_endian (p_print, (const uint8_t *)"K", BT_OCTET16_LEN);
#endif
uint8_t msg_len = 4 /* KeyID size */;
uint8_t msg[4];
p = msg;
ARRAY_TO_STREAM(p, keyid, 4);
#if (SMP_DEBUG == TRUE)
p_print = msg;
smp_debug_print_nbyte_little_endian (p_print,(const uint8_t *) "M", msg_len);
#endif
bool ret = true;
uint8_t cmac[BT_OCTET16_LEN];
if (!aes_cipher_msg_auth_code(key, msg, msg_len, BT_OCTET16_LEN, cmac))
{
SMP_TRACE_ERROR("%s failed",__func__);
ret = false;
}
#if (SMP_DEBUG == TRUE)
p_print = cmac;
smp_debug_print_nbyte_little_endian (p_print, (const uint8_t *)"AES-CMAC", BT_OCTET16_LEN);
#endif
p = c;
ARRAY_TO_STREAM(p, cmac, BT_OCTET16_LEN);
return ret;
}
/*******************************************************************************
**
** Function smp_start_nonce_generation
**
** Description This function starts nonce generation.
**
** Returns void
**
*******************************************************************************/
void smp_start_nonce_generation(tSMP_CB *p_cb)
{
SMP_TRACE_DEBUG("%s", __func__);
p_cb->rand_enc_proc_state = SMP_GEN_NONCE_0_7;
btsnd_hcic_ble_rand((void *)smp_rand_back);
}
/*******************************************************************************
**
** Function smp_finish_nonce_generation
**
** Description This function finishes nonce generation.
**
** Returns void
**
*******************************************************************************/
void smp_finish_nonce_generation(tSMP_CB *p_cb)
{
SMP_TRACE_DEBUG("%s", __func__);
p_cb->rand_enc_proc_state = SMP_GEN_NONCE_8_15;
btsnd_hcic_ble_rand((void *)smp_rand_back);
}
/*******************************************************************************
**
** Function smp_process_new_nonce
**
** Description This function notifies SM that it has new nonce.
**
** Returns void
**
*******************************************************************************/
void smp_process_new_nonce(tSMP_CB *p_cb)
{
SMP_TRACE_DEBUG ("%s round %d", __func__, p_cb->round);
smp_sm_event(p_cb, SMP_HAVE_LOC_NONCE_EVT, NULL);
}
/*******************************************************************************
**
** Function smp_rand_back
**
** Description This function is to process the rand command finished,
** process the random/encrypted number for further action.
**
** Returns void
**
*******************************************************************************/
static void smp_rand_back(tBTM_RAND_ENC *p)
{
tSMP_CB *p_cb = &smp_cb;
uint8_t *pp = p->param_buf;
uint8_t failure = SMP_PAIR_FAIL_UNKNOWN;
uint8_t state = p_cb->rand_enc_proc_state & ~0x80;
SMP_TRACE_DEBUG ("%s state=0x%x", __func__, state);
if (p && p->status == HCI_SUCCESS)
{
switch (state)
{
case SMP_GEN_SRAND_MRAND:
memcpy((void *)p_cb->rand, p->param_buf, p->param_len);
smp_generate_rand_cont(p_cb, NULL);
break;
case SMP_GEN_SRAND_MRAND_CONT:
memcpy((void *)&p_cb->rand[8], p->param_buf, p->param_len);
smp_generate_confirm(p_cb, NULL);
break;
case SMP_GEN_DIV_LTK:
STREAM_TO_UINT16(p_cb->div, pp);
smp_generate_ltk_cont(p_cb, NULL);
break;
case SMP_GEN_DIV_CSRK:
STREAM_TO_UINT16(p_cb->div, pp);
smp_compute_csrk(p_cb, NULL);
break;
case SMP_GEN_TK:
smp_proc_passkey(p_cb, p);
break;
case SMP_GEN_RAND_V:
memcpy(p_cb->enc_rand, p->param_buf, BT_OCTET8_LEN);
smp_generate_y(p_cb, NULL);
break;
case SMP_GENERATE_PRIVATE_KEY_0_7:
case SMP_GENERATE_PRIVATE_KEY_8_15:
case SMP_GENERATE_PRIVATE_KEY_16_23:
case SMP_GENERATE_PRIVATE_KEY_24_31:
smp_continue_private_key_creation(p_cb, p);
break;
case SMP_GEN_NONCE_0_7:
memcpy((void *)p_cb->rand, p->param_buf, p->param_len);
smp_finish_nonce_generation(p_cb);
break;
case SMP_GEN_NONCE_8_15:
memcpy((void *)&p_cb->rand[8], p->param_buf, p->param_len);
smp_process_new_nonce(p_cb);
break;
}
return;
}
SMP_TRACE_ERROR("%s key generation failed: (%d)", __func__, p_cb->rand_enc_proc_state);
smp_sm_event(p_cb, SMP_AUTH_CMPL_EVT, &failure);
}
#endif