Support for H7 function for key derivation (1fb7de76) · Commits · e / os / android_packages_modules_Bluetooth

system/stack/include/btm_api_types.h

+6 −5

Original line number	Diff line number	Diff line
		@@ -1638,12 +1638,13 @@ typedef uint8_t tBTM_LE_KEY_TYPE;
		typedef uint8_t tBTM_LE_AUTH_REQ;
		#define BTM_LE_SC_SUPPORT_BIT SMP_SC_SUPPORT_BIT /* (1 << 3) */
		#define BTM_LE_KP_SUPPORT_BIT SMP_KP_SUPPORT_BIT /* (1 << 4) */
		#define BTM_LE_H7_SUPPORT_BIT SMP_H7_SUPPORT_BIT /* (1 << 5) */

		#define BTM_LE_AUTH_REQ_SC_ONLY SMP_AUTH_SC_ENC_ONLY /* 1 << 3 */
		#define BTM_LE_AUTH_REQ_SC_BOND SMP_AUTH_SC_GB /* 1001 */
		#define BTM_LE_AUTH_REQ_SC_MITM SMP_AUTH_SC_MITM_NB /* 1100 */
		#define BTM_LE_AUTH_REQ_SC_MITM_BOND SMP_AUTH_SC_MITM_GB /* 1101 */
		#define BTM_LE_AUTH_REQ_MASK SMP_AUTH_MASK /* 0x1D */
		#define BTM_LE_AUTH_REQ_SC_ONLY SMP_AUTH_SC_ENC_ONLY /* 00101000 */
		#define BTM_LE_AUTH_REQ_SC_BOND SMP_AUTH_SC_GB /* 00101001 */
		#define BTM_LE_AUTH_REQ_SC_MITM SMP_AUTH_SC_MITM_NB /* 00101100 */
		#define BTM_LE_AUTH_REQ_SC_MITM_BOND SMP_AUTH_SC_MITM_GB /* 00101101 */
		#define BTM_LE_AUTH_REQ_MASK SMP_AUTH_MASK /* 0x3D */

		/* LE security level */
		#define BTM_LE_SEC_NONE SMP_SEC_NONE

system/stack/include/smp_api_types.h

+9 −6

Original line number	Diff line number	Diff line
		@@ -128,10 +128,11 @@ typedef uint8_t tSMP_OOB_DATA_TYPE;
		#define SMP_AUTH_YN_BIT (1 << 2)
		#define SMP_SC_SUPPORT_BIT (1 << 3)
		#define SMP_KP_SUPPORT_BIT (1 << 4)
		#define SMP_H7_SUPPORT_BIT (1 << 5)

		#define SMP_AUTH_MASK \
		(SMP_AUTH_GEN_BOND \| SMP_AUTH_YN_BIT \| SMP_SC_SUPPORT_BIT \| \
		SMP_KP_SUPPORT_BIT)
		SMP_KP_SUPPORT_BIT \| SMP_H7_SUPPORT_BIT)

		#define SMP_AUTH_BOND SMP_AUTH_GEN_BOND

		@@ -149,18 +150,20 @@ typedef uint8_t tSMP_OOB_DATA_TYPE;
		#define SMP_AUTH_GB_IOCAP (SMP_AUTH_GEN_BOND \| SMP_AUTH_YN_BIT)

		/* Secure Connections, no MITM, no Bonding */
		#define SMP_AUTH_SC_ENC_ONLY (SMP_SC_SUPPORT_BIT)
		#define SMP_AUTH_SC_ENC_ONLY (SMP_H7_SUPPORT_BIT \| SMP_SC_SUPPORT_BIT)

		/* Secure Connections, no MITM, Bonding */
		#define SMP_AUTH_SC_GB (SMP_SC_SUPPORT_BIT \| SMP_AUTH_GEN_BOND)
		#define SMP_AUTH_SC_GB \
		(SMP_H7_SUPPORT_BIT \| SMP_SC_SUPPORT_BIT \| SMP_AUTH_GEN_BOND)

		/* Secure Connections, MITM, no Bonding */
		#define SMP_AUTH_SC_MITM_NB \
		(SMP_SC_SUPPORT_BIT \| SMP_AUTH_YN_BIT \| SMP_AUTH_NO_BOND)
		(SMP_H7_SUPPORT_BIT \| SMP_SC_SUPPORT_BIT \| SMP_AUTH_YN_BIT \| SMP_AUTH_NO_BOND)

		/* Secure Connections, MITM, Bonding */
		#define SMP_AUTH_SC_MITM_GB \
		(SMP_SC_SUPPORT_BIT \| SMP_AUTH_YN_BIT \| SMP_AUTH_GEN_BOND)
		(SMP_H7_SUPPORT_BIT \| SMP_SC_SUPPORT_BIT \| SMP_AUTH_YN_BIT \| \
		SMP_AUTH_GEN_BOND)

		/* All AuthReq RFU bits are set to 1 - NOTE: reserved bit in Bonding_Flags is
		* not set */

system/stack/smp/smp_act.cc

+11 −2

Original line number	Diff line number	Diff line
		@@ -209,14 +209,16 @@ void smp_send_app_cback(tSMP_CB* p_cb, tSMP_INT_DATA* p_data) {
		p_cb->loc_enc_size = cb_data.io_req.max_key_size;
		p_cb->local_i_key = cb_data.io_req.init_keys;
		p_cb->local_r_key = cb_data.io_req.resp_keys;
		p_cb->loc_auth_req \|= SMP_H7_SUPPORT_BIT;

		p_cb->local_i_key &= ~SMP_SEC_KEY_TYPE_LK;
		p_cb->local_r_key &= ~SMP_SEC_KEY_TYPE_LK;

		SMP_TRACE_WARNING(
		"for SMP over BR max_key_size: 0x%02x,\
		local_i_key: 0x%02x, local_r_key: 0x%02x",
		p_cb->loc_enc_size, p_cb->local_i_key, p_cb->local_r_key);
		local_i_key: 0x%02x, local_r_key: 0x%02x, p_cb->loc_auth_req: 0x%02x",
		p_cb->loc_enc_size, p_cb->local_i_key, p_cb->local_r_key,
		p_cb->loc_auth_req);

		smp_br_state_machine_event(p_cb, SMP_BR_KEYS_RSP_EVT, NULL);
		break;
		@@ -845,6 +847,13 @@ void smp_br_check_authorization_request(tSMP_CB* p_cb, tSMP_INT_DATA* p_data) {
		p_cb->local_r_key &= (SMP_SEC_KEY_TYPE_ID \| SMP_SEC_KEY_TYPE_CSRK);
		}

		/* Check if H7 function needs to be used for key derivation*/
		if ((p_cb->loc_auth_req & SMP_H7_SUPPORT_BIT) &&
		(p_cb->peer_auth_req & SMP_H7_SUPPORT_BIT)) {
		p_cb->key_derivation_h7_used = TRUE;
		}
		SMP_TRACE_DEBUG("%s: use h7 = %d", __func__, p_cb->key_derivation_h7_used);

		SMP_TRACE_DEBUG(
		"%s rcvs upgrades: i_keys=0x%x r_keys=0x%x "
		"(i-initiator r-responder)",

system/stack/smp/smp_int.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -299,6 +299,7 @@ typedef struct {
		/* either in Secure Connections mode or not at all */
		tSMP_ASSO_MODEL selected_association_model;
		bool le_secure_connections_mode_is_used;
		bool key_derivation_h7_used;
		bool le_sc_kp_notif_is_used;
		tSMP_SC_KEY_TYPE local_keypress_notification;
		tSMP_SC_KEY_TYPE peer_keypress_notification;
		@@ -528,6 +529,7 @@ extern 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* f3);
		extern bool smp_calculate_h6(uint8_t* w, uint8_t* keyid, uint8_t* h2);
		extern bool smp_calculate_h7(uint8_t* salt, uint8_t* w, uint8_t* h2);
		#if (SMP_DEBUG == TRUE)
		extern void smp_debug_print_nbyte_little_endian(uint8_t* p,
		const char* key_name,

system/stack/smp/smp_keys.cc

+59 −5

Original line number	Diff line number	Diff line
		@@ -1634,6 +1634,8 @@ 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;
		BT_OCTET16 salt = {0x31, 0x70, 0x6D, 0x74, 0x00, 0x00, 0x00, 0x00,
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};

		SMP_TRACE_DEBUG("%s", __func__);

		@@ -1659,6 +1661,9 @@ bool smp_calculate_link_key_from_long_term_key(tSMP_CB* p_cb) {
		BT_OCTET16 intermediate_link_key;
		bool ret = true;

		if (p_cb->key_derivation_h7_used)
		ret = smp_calculate_h7((uint8_t*)salt, p_cb->ltk, intermediate_link_key);
		else
		ret = smp_calculate_h6(p_cb->ltk, (uint8_t)"1pmt" / reversed "tmp1" */,
		intermediate_link_key);
		if (!ret) {
		@@ -1724,6 +1729,8 @@ 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];
		BT_OCTET16 salt = {0x32, 0x70, 0x6D, 0x74, 0x00, 0x00, 0x00, 0x00,
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};

		SMP_TRACE_DEBUG("%s", __func__);

		@@ -1754,9 +1761,14 @@ bool smp_calculate_long_term_key_from_link_key(tSMP_CB* p_cb) {
		REVERSE_ARRAY_TO_STREAM(p1, p2, 16);

		BT_OCTET16 intermediate_long_term_key;
		if (p_cb->key_derivation_h7_used) {
		ret = smp_calculate_h7((uint8_t*)salt, rev_link_key,
		intermediate_long_term_key);
		} else {
		/* "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__);
		@@ -1849,6 +1861,48 @@ bool smp_calculate_h6(uint8_t* w, uint8_t* keyid, uint8_t* c) {
		return ret;
		}

		/*******************************************************************************
		**
		** Function smp_calculate_h7
		**
		** Description The function calculates
		** C = h7(SALT, W) = AES-CMAC (W)
		** SALT
		** where
		** input: W is 128 bit,
		** SALT is 128 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_h7(uint8_t* salt, uint8_t* w, uint8_t* c) {
		SMP_TRACE_DEBUG("%s", __FUNCTION__);

		uint8_t key[BT_OCTET16_LEN];
		uint8_t* p = key;
		ARRAY_TO_STREAM(p, salt, BT_OCTET16_LEN);

		uint8_t msg_len = BT_OCTET16_LEN /* msg size */;
		uint8_t msg[BT_OCTET16_LEN];
		p = msg;
		ARRAY_TO_STREAM(p, w, BT_OCTET16_LEN);

		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", __FUNCTION__);
		ret = false;
		}

		p = c;
		ARRAY_TO_STREAM(p, cmac, BT_OCTET16_LEN);
		return ret;
		}

		/**
		* This function generates nonce.
		*/