text: /**
   * @file smp.c
   * Security Manager Protocol implementation
   */
  
  /*
   * Copyright (c) 2017 Nordic Semiconductor ASA
   * Copyright (c) 2015-2016 Intel Corporation
   *
   * SPDX-License-Identifier: Apache-2.0
   */
  
  #include <zephyr.h>
  #include <stddef.h>
  #include <errno.h>
  #include <string.h>
  #include <sys/atomic.h>
  #include <sys/util.h>
  #include <sys/byteorder.h>
  #include <debug/stack.h>
  
  #include <net/buf.h>
  #include <bluetooth/hci.h>
  #include <bluetooth/bluetooth.h>
  #include <bluetooth/conn.h>
  #include <bluetooth/buf.h>
  
  #include <tinycrypt/constants.h>
  #include <tinycrypt/aes.h>
  #include <tinycrypt/utils.h>
  #include <tinycrypt/cmac_mode.h>
  
  #define BT_DBG_ENABLED IS_ENABLED(CONFIG_BT_DEBUG_SMP)
  #define LOG_MODULE_NAME bt_smp
  #include "common/log.h"
  
  #include "hci_core.h"
  #include "ecc.h"
  #include "keys.h"
  #include "conn_internal.h"
  #include "l2cap_internal.h"
  #include "smp.h"
  
  #define SMP_TIMEOUT K_SECONDS(30)
  
  #if defined(CONFIG_BT_SIGNING)
  #define SIGN_DIST BT_SMP_DIST_SIGN
  #else
  #define SIGN_DIST 0
  #endif
  
  #if defined(CONFIG_BT_PRIVACY)
  #define ID_DIST BT_SMP_DIST_ID_KEY
  #else
  #define ID_DIST 0
  #endif
  
  #if defined(CONFIG_BT_BREDR)
  #define LINK_DIST BT_SMP_DIST_LINK_KEY
  #else
  #define LINK_DIST 0
  #endif
  
  #define RECV_KEYS (BT_SMP_DIST_ENC_KEY | BT_SMP_DIST_ID_KEY | SIGN_DIST |\
  		   LINK_DIST)
  #define SEND_KEYS (BT_SMP_DIST_ENC_KEY | ID_DIST | SIGN_DIST | LINK_DIST)
  
  #define RECV_KEYS_SC (RECV_KEYS & ~(BT_SMP_DIST_ENC_KEY))
  #define SEND_KEYS_SC (SEND_KEYS & ~(BT_SMP_DIST_ENC_KEY))
  
  #define BR_RECV_KEYS_SC (RECV_KEYS & ~(LINK_DIST))
  #define BR_SEND_KEYS_SC (SEND_KEYS & ~(LINK_DIST))
  
  #define BT_SMP_AUTH_MASK	0x07
  
  #if defined(CONFIG_BT_BONDABLE)
  #define BT_SMP_AUTH_BONDING_FLAGS BT_SMP_AUTH_BONDING
  #else
  #define BT_SMP_AUTH_BONDING_FLAGS 0
  #endif /* CONFIG_BT_BONDABLE */
  
  #if defined(CONFIG_BT_BREDR)
  
  #define BT_SMP_AUTH_MASK_SC	0x2f
  #if defined(CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY)
  #define BT_SMP_AUTH_DEFAULT (BT_SMP_AUTH_BONDING_FLAGS | BT_SMP_AUTH_CT2)
  #else
  #define BT_SMP_AUTH_DEFAULT (BT_SMP_AUTH_BONDING_FLAGS | BT_SMP_AUTH_CT2 |\
  			     BT_SMP_AUTH_SC)
  #endif /* CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY */
  
  #else
  
  #define BT_SMP_AUTH_MASK_SC	0x0f
  #if defined(CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY)
  #define BT_SMP_AUTH_DEFAULT (BT_SMP_AUTH_BONDING_FLAGS)
  #else
  #define BT_SMP_AUTH_DEFAULT (BT_SMP_AUTH_BONDING_FLAGS | BT_SMP_AUTH_SC)
  #endif /* CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY */
  
  #endif /* CONFIG_BT_BREDR */
  
  enum pairing_method {
  	JUST_WORKS,		/* JustWorks pairing */
  	PASSKEY_INPUT,		/* Passkey Entry input */
  	PASSKEY_DISPLAY,	/* Passkey Entry display */
  	PASSKEY_CONFIRM,	/* Passkey confirm */
  	PASSKEY_ROLE,		/* Passkey Entry depends on role */
  	LE_SC_OOB,		/* LESC Out of Band */
  	LEGACY_OOB,		/* Legacy Out of Band */
  };
  
  enum {
  	SMP_FLAG_CFM_DELAYED,	/* if confirm should be send when TK is valid */
  	SMP_FLAG_ENC_PENDING,	/* if waiting for an encryption change event */
  	SMP_FLAG_KEYS_DISTR,	/* if keys distribution phase is in progress */
  	SMP_FLAG_PAIRING,	/* if pairing is in progress */
  	SMP_FLAG_TIMEOUT,	/* if SMP timeout occurred */
  	SMP_FLAG_SC,		/* if LE Secure Connections is used */
  	SMP_FLAG_PKEY_SEND,	/* if should send Public Key when available */
  	SMP_FLAG_DHKEY_PENDING,	/* if waiting for local DHKey */
  	SMP_FLAG_DHKEY_GEN,     /* if generating DHKey */
  	SMP_FLAG_DHKEY_SEND,	/* if should generate and send DHKey Check */
  	SMP_FLAG_USER,		/* if waiting for user input */
  	SMP_FLAG_DISPLAY,       /* if display_passkey() callback was called */
  	SMP_FLAG_OOB_PENDING,	/* if waiting for OOB data */
  	SMP_FLAG_BOND,		/* if bonding */
  	SMP_FLAG_SC_DEBUG_KEY,	/* if Secure Connection are using debug key */
  	SMP_FLAG_SEC_REQ,	/* if Security Request was sent/received */
  	SMP_FLAG_DHCHECK_WAIT,	/* if waiting for remote DHCheck (as slave) */
  	SMP_FLAG_DERIVE_LK,	/* if Link Key should be derived */
  	SMP_FLAG_BR_CONNECTED,	/* if BR/EDR channel is connected */
  	SMP_FLAG_BR_PAIR,	/* if should start BR/EDR pairing */
  	SMP_FLAG_CT2,		/* if should use H7 for keys derivation */
  
  	/* Total number of flags - must be at the end */
  	SMP_NUM_FLAGS,
  };
  
  /* SMP channel specific context */
  struct bt_smp {
  	/* The channel this context is associated with */
  	struct bt_l2cap_le_chan		chan;
  
  	/* Commands that remote is allowed to send */
  	ATOMIC_DEFINE(allowed_cmds, BT_SMP_NUM_CMDS);
  
  	/* Flags for SMP state machine */
  	ATOMIC_DEFINE(flags, SMP_NUM_FLAGS);
  
  	/* Type of method used for pairing */
  	uint8_t				method;
  
  	/* Pairing Request PDU */
  	uint8_t				preq[7];
  
  	/* Pairing Response PDU */
  	uint8_t				prsp[7];
  
  	/* Pairing Confirm PDU */
  	uint8_t				pcnf[16];
  
  	/* Local random number */
  	uint8_t				prnd[16];
  
  	/* Remote random number */
  	uint8_t				rrnd[16];
  
  	/* Temporary key */
  	uint8_t				tk[16];
  
  	/* Remote Public Key for LE SC */
  	uint8_t				pkey[64];
  
  	/* DHKey */
  	uint8_t				dhkey[32];
  
  	/* Remote DHKey check */
  	uint8_t				e[16];
  
  	/* MacKey */
  	uint8_t				mackey[16];
  
  	/* LE SC passkey */
  	uint32_t				passkey;
  
  	/* LE SC passkey round */
  	uint8_t				passkey_round;
  
  	/* LE SC local OOB data */
  	const struct bt_le_oob_sc_data	*oobd_local;
  
  	/* LE SC remote OOB data */
  	const struct bt_le_oob_sc_data	*oobd_remote;
  
  	/* Local key distribution */
  	uint8_t				local_dist;
  
  	/* Remote key distribution */
  	uint8_t				remote_dist;
  
  	/* Delayed work for timeout handling */
  	struct k_delayed_work		work;
  };
  
  static unsigned int fixed_passkey = BT_PASSKEY_INVALID;
  
  #define DISPLAY_FIXED(smp) (IS_ENABLED(CONFIG_BT_FIXED_PASSKEY) && \
  			    fixed_passkey != BT_PASSKEY_INVALID && \
  			    (smp)->method == PASSKEY_DISPLAY)
  
  #if !defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
  /* based on table 2.8 Core Spec 2.3.5.1 Vol. 3 Part H */
  static const uint8_t gen_method_legacy[5 /* remote */][5 /* local */] = {
  	{ JUST_WORKS, JUST_WORKS, PASSKEY_INPUT, JUST_WORKS, PASSKEY_INPUT },
  	{ JUST_WORKS, JUST_WORKS, PASSKEY_INPUT, JUST_WORKS, PASSKEY_INPUT },
  	{ PASSKEY_DISPLAY, PASSKEY_DISPLAY, PASSKEY_INPUT, JUST_WORKS,
  	  PASSKEY_DISPLAY },
  	{ JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS },
  	{ PASSKEY_DISPLAY, PASSKEY_DISPLAY, PASSKEY_INPUT, JUST_WORKS,
  	  PASSKEY_ROLE },
  };
  #endif /* CONFIG_BT_SMP_SC_PAIR_ONLY */
  
  #if !defined(CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY)
  /* based on table 2.8 Core Spec 2.3.5.1 Vol. 3 Part H */
  static const uint8_t gen_method_sc[5 /* remote */][5 /* local */] = {
  	{ JUST_WORKS, JUST_WORKS, PASSKEY_INPUT, JUST_WORKS, PASSKEY_INPUT },
  	{ JUST_WORKS, PASSKEY_CONFIRM, PASSKEY_INPUT, JUST_WORKS,
  	  PASSKEY_CONFIRM },
  	{ PASSKEY_DISPLAY, PASSKEY_DISPLAY, PASSKEY_INPUT, JUST_WORKS,
  	  PASSKEY_DISPLAY },
  	{ JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS },
  	{ PASSKEY_DISPLAY, PASSKEY_CONFIRM, PASSKEY_INPUT, JUST_WORKS,
  	  PASSKEY_CONFIRM },
  };
  #endif /* !CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY */
  
  #if defined(CONFIG_BT_BREDR)
  /* SMP over BR/EDR channel specific context */
  struct bt_smp_br {
  	/* The channel this context is associated with */
  	struct bt_l2cap_br_chan	chan;
  
  	/* Commands that remote is allowed to send */
  	ATOMIC_DEFINE(allowed_cmds, BT_SMP_NUM_CMDS);
  
  	/* Flags for SMP state machine */
  	ATOMIC_DEFINE(flags, SMP_NUM_FLAGS);
  
  	/* Local key distribution */
  	uint8_t			local_dist;
  
  	/* Remote key distribution */
  	uint8_t			remote_dist;
  
  	/* Encryption Key Size used for connection */
  	uint8_t 			enc_key_size;
  
  	/* Delayed work for timeout handling */
  	struct k_delayed_work 	work;
  };
  
  static struct bt_smp_br bt_smp_br_pool[CONFIG_BT_MAX_CONN];
  #endif /* CONFIG_BT_BREDR */
  
  static struct bt_smp bt_smp_pool[CONFIG_BT_MAX_CONN];
  static bool bondable = IS_ENABLED(CONFIG_BT_BONDABLE);
  static bool oobd_present;
  static bool sc_supported;
  static const uint8_t *sc_public_key;
  static K_SEM_DEFINE(sc_local_pkey_ready, 0, 1);
  
  static bool le_sc_supported(void)
  {
  	/*
  	 * If controller based ECC is to be used it must support
  	 * "LE Read Local P-256 Public Key" and "LE Generate DH Key" commands.
  	 * Otherwise LE SC are not supported.
  	 */
  	if (IS_ENABLED(CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY)) {
  		return false;
  	}
  
  	return BT_CMD_TEST(bt_dev.supported_commands, 34, 1) &&
  	       BT_CMD_TEST(bt_dev.supported_commands, 34, 2);
  }
  
  static uint8_t get_io_capa(void)
  {
  	if (!bt_auth) {
  		goto no_callbacks;
  	}
  
  	/* Passkey Confirmation is valid only for LE SC */
  	if (bt_auth->passkey_display && bt_auth->passkey_entry &&
  	    (bt_auth->passkey_confirm || !sc_supported)) {
  		return BT_SMP_IO_KEYBOARD_DISPLAY;
  	}
  
  	/* DisplayYesNo is useful only for LE SC */
  	if (sc_supported && bt_auth->passkey_display &&
  	    bt_auth->passkey_confirm) {
  		return BT_SMP_IO_DISPLAY_YESNO;
  	}
  
  	if (bt_auth->passkey_entry) {
  		if (IS_ENABLED(CONFIG_BT_FIXED_PASSKEY) &&
  		    fixed_passkey != BT_PASSKEY_INVALID) {
  			return BT_SMP_IO_KEYBOARD_DISPLAY;
  		} else {
  			return BT_SMP_IO_KEYBOARD_ONLY;
  		}
  	}
  
  	if (bt_auth->passkey_display) {
  		return BT_SMP_IO_DISPLAY_ONLY;
  	}
  
  no_callbacks:
  	if (IS_ENABLED(CONFIG_BT_FIXED_PASSKEY) &&
  	    fixed_passkey != BT_PASSKEY_INVALID) {
  		return BT_SMP_IO_DISPLAY_ONLY;
  	} else {
  		return BT_SMP_IO_NO_INPUT_OUTPUT;
  	}
  }
  
  #if !defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
  static uint8_t legacy_get_pair_method(struct bt_smp *smp, uint8_t remote_io);
  #endif
  
  static bool smp_keys_check(struct bt_conn *conn)
  {
  	if (atomic_test_bit(conn->flags, BT_CONN_FORCE_PAIR)) {
  		return false;
  	}
  
  	if (!conn->le.keys) {
  		conn->le.keys = bt_keys_find(BT_KEYS_LTK_P256,
  						     conn->id, &conn->le.dst);
  		if (!conn->le.keys) {
  			conn->le.keys = bt_keys_find(BT_KEYS_LTK,
  						     conn->id,
  						     &conn->le.dst);
  		}
  	}
  
  	if (!conn->le.keys ||
  	    !(conn->le.keys->keys & (BT_KEYS_LTK | BT_KEYS_LTK_P256))) {
  		return false;
  	}
  
  	if (conn->required_sec_level > BT_SECURITY_L2 &&
  	    !(conn->le.keys->flags & BT_KEYS_AUTHENTICATED)) {
  		return false;
  	}
  
  	if (conn->required_sec_level > BT_SECURITY_L3 &&
  	    !(conn->le.keys->flags & BT_KEYS_AUTHENTICATED) &&
  	    !(conn->le.keys->keys & BT_KEYS_LTK_P256) &&
  	    !(conn->le.keys->enc_size == BT_SMP_MAX_ENC_KEY_SIZE)) {
  		return false;
  	}
  
  	return true;
  }
  
  static uint8_t get_pair_method(struct bt_smp *smp, uint8_t remote_io)
  {
  #if !defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
  	if (!atomic_test_bit(smp->flags, SMP_FLAG_SC)) {
  		return legacy_get_pair_method(smp, remote_io);
  	}
  #endif
  
  #if !defined(CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY)
  	struct bt_smp_pairing *req, *rsp;
  
  	req = (struct bt_smp_pairing *)&smp->preq[1];
  	rsp = (struct bt_smp_pairing *)&smp->prsp[1];
  
  	if ((req->auth_req & rsp->auth_req) & BT_SMP_AUTH_SC) {
  		/* if one side has OOB data use OOB */
  		if ((req->oob_flag | rsp->oob_flag) & BT_SMP_OOB_DATA_MASK) {
  			return LE_SC_OOB;
  		}
  	}
  
  	if (remote_io > BT_SMP_IO_KEYBOARD_DISPLAY) {
  		return JUST_WORKS;
  	}
  
  	/* if none side requires MITM use JustWorks */
  	if (!((req->auth_req | rsp->auth_req) & BT_SMP_AUTH_MITM)) {
  		return JUST_WORKS;
  	}
  
  	return gen_method_sc[remote_io][get_io_capa()];
  #else
  	return JUST_WORKS;
  #endif
  }
  
  static enum bt_security_err security_err_get(uint8_t smp_err)
  {
  	switch (smp_err) {
  	case BT_SMP_ERR_PASSKEY_ENTRY_FAILED:
  	case BT_SMP_ERR_DHKEY_CHECK_FAILED:
  	case BT_SMP_ERR_NUMERIC_COMP_FAILED:
  	case BT_SMP_ERR_CONFIRM_FAILED:
  		return BT_SECURITY_ERR_AUTH_FAIL;
  	case BT_SMP_ERR_OOB_NOT_AVAIL:
  		return BT_SECURITY_ERR_OOB_NOT_AVAILABLE;
  	case BT_SMP_ERR_AUTH_REQUIREMENTS:
  	case BT_SMP_ERR_ENC_KEY_SIZE:
  		return BT_SECURITY_ERR_AUTH_REQUIREMENT;
  	case BT_SMP_ERR_PAIRING_NOTSUPP:
  	case BT_SMP_ERR_CMD_NOTSUPP:
  		return BT_SECURITY_ERR_PAIR_NOT_SUPPORTED;
  	case BT_SMP_ERR_REPEATED_ATTEMPTS:
  	case BT_SMP_ERR_BREDR_PAIRING_IN_PROGRESS:
  	case BT_SMP_ERR_CROSS_TRANSP_NOT_ALLOWED:
  		return BT_SECURITY_ERR_PAIR_NOT_ALLOWED;
  	case BT_SMP_ERR_INVALID_PARAMS:
  		return BT_SECURITY_ERR_INVALID_PARAM;
  	case BT_SMP_ERR_UNSPECIFIED:
  	default:
  		return BT_SECURITY_ERR_UNSPECIFIED;
  	}
  }
  
  static uint8_t smp_err_get(enum bt_security_err auth_err)
  {
  	switch (auth_err) {
  	case BT_SECURITY_ERR_OOB_NOT_AVAILABLE:
  		return BT_SMP_ERR_OOB_NOT_AVAIL;
  
  	case BT_SECURITY_ERR_AUTH_FAIL:
  	case BT_SECURITY_ERR_AUTH_REQUIREMENT:
  		return BT_SMP_ERR_AUTH_REQUIREMENTS;
  
  	case BT_SECURITY_ERR_PAIR_NOT_SUPPORTED:
  		return BT_SMP_ERR_PAIRING_NOTSUPP;
  
  	case BT_SECURITY_ERR_INVALID_PARAM:
  		return BT_SMP_ERR_INVALID_PARAMS;
  
  	case BT_SECURITY_ERR_PIN_OR_KEY_MISSING:
  	case BT_SECURITY_ERR_PAIR_NOT_ALLOWED:
  	case BT_SECURITY_ERR_UNSPECIFIED:
  		return BT_SMP_ERR_UNSPECIFIED;
  	default:
  		return 0;
  	}
  }
  
  static struct net_buf *smp_create_pdu(struct bt_smp *smp, uint8_t op, size_t len)
  {
  	struct bt_smp_hdr *hdr;
  	struct net_buf *buf;
  	k_timeout_t timeout;
  
  	/* Don't if session had already timed out */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_TIMEOUT)) {
  		timeout = K_NO_WAIT;
  	} else {
  		timeout = SMP_TIMEOUT;
  	}
  
  	/* Use smaller timeout if returning an error since that could be
  	 * caused by lack of buffers.
  	 */
  	buf = bt_l2cap_create_pdu_timeout(NULL, 0, timeout);
  	if (!buf) {
  		/* If it was not possible to allocate a buffer within the
  		 * timeout marked it as timed out.
  		 */
  		atomic_set_bit(smp->flags, SMP_FLAG_TIMEOUT);
  		return NULL;
  	}
  
  	hdr = net_buf_add(buf, sizeof(*hdr));
  	hdr->code = op;
  
  	return buf;
  }
  
  /* Cypher based Message Authentication Code (CMAC) with AES 128 bit
   *
   * Input    : key    ( 128-bit key )
   *          : in     ( message to be authenticated )
   *          : len    ( length of the message in octets )
   * Output   : out    ( message authentication code )
   */
  static int bt_smp_aes_cmac(const uint8_t *key, const uint8_t *in, size_t len,
  			   uint8_t *out)
  {
  	struct tc_aes_key_sched_struct sched;
  	struct tc_cmac_struct state;
  
  	if (tc_cmac_setup(&state, key, &sched) == TC_CRYPTO_FAIL) {
  		return -EIO;
  	}
  
  	if (tc_cmac_update(&state, in, len) == TC_CRYPTO_FAIL) {
  		return -EIO;
  	}
  
  	if (tc_cmac_final(out, &state) == TC_CRYPTO_FAIL) {
  		return -EIO;
  	}
  
  	return 0;
  }
  
  static int smp_d1(const uint8_t *key, uint16_t d, uint16_t r, uint8_t res[16])
  {
  	int err;
  
  	BT_DBG("key %s d %u r %u", bt_hex(key, 16), d, r);
  
  	sys_put_le16(d, &res[0]);
  	sys_put_le16(r, &res[2]);
  	memset(&res[4], 0, 16 - 4);
  
  	err = bt_encrypt_le(key, res, res);
  	if (err) {
  		return err;
  	}
  
  	BT_DBG("res %s", bt_hex(res, 16));
  	return 0;
  }
  
  static int smp_f4(const uint8_t *u, const uint8_t *v, const uint8_t *x,
  		  uint8_t z, uint8_t res[16])
  {
  	uint8_t xs[16];
  	uint8_t m[65];
  	int err;
  
  	BT_DBG("u %s", bt_hex(u, 32));
  	BT_DBG("v %s", bt_hex(v, 32));
  	BT_DBG("x %s z 0x%x", bt_hex(x, 16), z);
  
  	/*
  	 * U, V and Z are concatenated and used as input m to the function
  	 * AES-CMAC and X is used as the key k.
  	 *
  	 * Core Spec 4.2 Vol 3 Part H 2.2.5
  	 *
  	 * note:
  	 * bt_smp_aes_cmac uses BE data and smp_f4 accept LE so we swap
  	 */
  	sys_memcpy_swap(m, u, 32);
  	sys_memcpy_swap(m + 32, v, 32);
  	m[64] = z;
  
  	sys_memcpy_swap(xs, x, 16);
  
  	err = bt_smp_aes_cmac(xs, m, sizeof(m), res);
  	if (err) {
  		return err;
  	}
  
  	sys_mem_swap(res, 16);
  
  	BT_DBG("res %s", bt_hex(res, 16));
  
  	return err;
  }
  
  static int smp_f5(const uint8_t *w, const uint8_t *n1, const uint8_t *n2,
  		  const bt_addr_le_t *a1, const bt_addr_le_t *a2, uint8_t *mackey,
  		  uint8_t *ltk)
  {
  	static const uint8_t salt[16] = { 0x6c, 0x88, 0x83, 0x91, 0xaa, 0xf5,
  					  0xa5, 0x38, 0x60, 0x37, 0x0b, 0xdb,
  					  0x5a, 0x60, 0x83, 0xbe };
  	uint8_t m[53] = { 0x00, /* counter */
  			  0x62, 0x74, 0x6c, 0x65, /* keyID */
  			  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /*n1*/
  			  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  			  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /*2*/
  			  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  			  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* a1 */
  			  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* a2 */
  			  0x01, 0x00 /* length */ };
  	uint8_t t[16], ws[32];
  	int err;
  
  	BT_DBG("w %s", bt_hex(w, 32));
  	BT_DBG("n1 %s", bt_hex(n1, 16));
  	BT_DBG("n2 %s", bt_hex(n2, 16));
  
  	sys_memcpy_swap(ws, w, 32);
  
  	err = bt_smp_aes_cmac(salt, ws, 32, t);
  	if (err) {
  		return err;
  	}
  
  	BT_DBG("t %s", bt_hex(t, 16));
  
  	sys_memcpy_swap(m + 5, n1, 16);
  	sys_memcpy_swap(m + 21, n2, 16);
  	m[37] = a1->type;
  	sys_memcpy_swap(m + 38, a1->a.val, 6);
  	m[44] = a2->type;
  	sys_memcpy_swap(m + 45, a2->a.val, 6);
  
  	err = bt_smp_aes_cmac(t, m, sizeof(m), mackey);
  	if (err) {
  		return err;
  	}
  
  	BT_DBG("mackey %1s", bt_hex(mackey, 16));
  
  	sys_mem_swap(mackey, 16);
  
  	/* counter for ltk is 1 */
  	m[0] = 0x01;
  
  	err = bt_smp_aes_cmac(t, m, sizeof(m), ltk);
  	if (err) {
  		return err;
  	}
  
  	BT_DBG("ltk %s", bt_hex(ltk, 16));
  
  	sys_mem_swap(ltk, 16);
  
  	return 0;
  }
  
  static int smp_f6(const uint8_t *w, const uint8_t *n1, const uint8_t *n2,
  		  const uint8_t *r, const uint8_t *iocap, const bt_addr_le_t *a1,
  		  const bt_addr_le_t *a2, uint8_t *check)
  {
  	uint8_t ws[16];
  	uint8_t m[65];
  	int err;
  
  	BT_DBG("w %s", bt_hex(w, 16));
  	BT_DBG("n1 %s", bt_hex(n1, 16));
  	BT_DBG("n2 %s", bt_hex(n2, 16));
  	BT_DBG("r %s", bt_hex(r, 16));
  	BT_DBG("io_cap %s", bt_hex(iocap, 3));
  	BT_DBG("a1 %s", bt_hex(a1, 7));
  	BT_DBG("a2 %s", bt_hex(a2, 7));
  
  	sys_memcpy_swap(m, n1, 16);
  	sys_memcpy_swap(m + 16, n2, 16);
  	sys_memcpy_swap(m + 32, r, 16);
  	sys_memcpy_swap(m + 48, iocap, 3);
  
  	m[51] = a1->type;
  	memcpy(m + 52, a1->a.val, 6);
  	sys_memcpy_swap(m + 52, a1->a.val, 6);
  
  	m[58] = a2->type;
  	memcpy(m + 59, a2->a.val, 6);
  	sys_memcpy_swap(m + 59, a2->a.val, 6);
  
  	sys_memcpy_swap(ws, w, 16);
  
  	err = bt_smp_aes_cmac(ws, m, sizeof(m), check);
  	if (err) {
  		return err;
  	}
  
  	BT_DBG("res %s", bt_hex(check, 16));
  
  	sys_mem_swap(check, 16);
  
  	return 0;
  }
  
  static int smp_g2(const uint8_t u[32], const uint8_t v[32],
  		  const uint8_t x[16], const uint8_t y[16], uint32_t *passkey)
  {
  	uint8_t m[80], xs[16];
  	int err;
  
  	BT_DBG("u %s", bt_hex(u, 32));
  	BT_DBG("v %s", bt_hex(v, 32));
  	BT_DBG("x %s", bt_hex(x, 16));
  	BT_DBG("y %s", bt_hex(y, 16));
  
  	sys_memcpy_swap(m, u, 32);
  	sys_memcpy_swap(m + 32, v, 32);
  	sys_memcpy_swap(m + 64, y, 16);
  
  	sys_memcpy_swap(xs, x, 16);
  
  	/* reuse xs (key) as buffer for result */
  	err = bt_smp_aes_cmac(xs, m, sizeof(m), xs);
  	if (err) {
  		return err;
  	}
  	BT_DBG("res %s", bt_hex(xs, 16));
  
  	memcpy(passkey, xs + 12, 4);
  	*passkey = sys_be32_to_cpu(*passkey) % 1000000;
  
  	BT_DBG("passkey %u", *passkey);
  
  	return 0;
  }
  
  static uint8_t get_encryption_key_size(struct bt_smp *smp)
  {
  	struct bt_smp_pairing *req, *rsp;
  
  	req = (struct bt_smp_pairing *)&smp->preq[1];
  	rsp = (struct bt_smp_pairing *)&smp->prsp[1];
  
  	/*
  	 * The smaller value of the initiating and responding devices maximum
  	 * encryption key length parameters shall be used as the encryption key
  	 * size.
  	 */
  	return MIN(req->max_key_size, rsp->max_key_size);
  }
  
  /* Check that if a new pairing procedure with an existing bond will not lower
   * the established security level of the bond.
   */
  static bool update_keys_check(struct bt_smp *smp, struct bt_keys *keys)
  {
  	if (IS_ENABLED(CONFIG_BT_SMP_DISABLE_LEGACY_JW_PASSKEY) &&
  	    !atomic_test_bit(smp->flags, SMP_FLAG_SC) &&
  	    smp->method != LEGACY_OOB) {
  		return false;
  	}
  
  	if (IS_ENABLED(CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY) &&
  	    smp->method != LEGACY_OOB) {
  		return false;
  	}
  
  	if (!keys ||
  	    !(keys->keys & (BT_KEYS_LTK_P256 | BT_KEYS_LTK))) {
  		return true;
  	}
  
  	if (keys->enc_size > get_encryption_key_size(smp)) {
  		return false;
  	}
  
  	if ((keys->keys & BT_KEYS_LTK_P256) &&
  	    !atomic_test_bit(smp->flags, SMP_FLAG_SC)) {
  		return false;
  	}
  
  	if ((keys->flags & BT_KEYS_AUTHENTICATED) &&
  	     smp->method == JUST_WORKS) {
  		return false;
  	}
  
  	if (!IS_ENABLED(CONFIG_BT_SMP_ALLOW_UNAUTH_OVERWRITE) &&
  	    (!(keys->flags & BT_KEYS_AUTHENTICATED)
  	     && smp->method == JUST_WORKS)) {
  		return false;
  	}
  
  	return true;
  }
  
  static bool update_debug_keys_check(struct bt_smp *smp)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  
  	if (!conn->le.keys) {
  		conn->le.keys = bt_keys_get_addr(conn->id, &conn->le.dst);
  	}
  
  	if (!conn->le.keys ||
  	    !(conn->le.keys->keys & (BT_KEYS_LTK_P256 | BT_KEYS_LTK))) {
  		return true;
  	}
  
  	if (conn->le.keys->flags & BT_KEYS_DEBUG) {
  		return true;
  	}
  
  	return false;
  }
  
  #if defined(CONFIG_BT_PRIVACY) || defined(CONFIG_BT_SIGNING) || \
  	!defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
  /* For TX callbacks */
  static void smp_pairing_complete(struct bt_smp *smp, uint8_t status);
  #if defined(CONFIG_BT_BREDR)
  static void smp_pairing_br_complete(struct bt_smp_br *smp, uint8_t status);
  #endif
  
  static void smp_check_complete(struct bt_conn *conn, uint8_t dist_complete)
  {
  	struct bt_l2cap_chan *chan;
  
  	if (conn->type == BT_CONN_TYPE_LE) {
  		struct bt_smp *smp;
  
  		chan = bt_l2cap_le_lookup_tx_cid(conn, BT_L2CAP_CID_SMP);
  		__ASSERT(chan, "No SMP channel found");
  
  		smp = CONTAINER_OF(chan, struct bt_smp, chan);
  		smp->local_dist &= ~dist_complete;
  
  		/* if all keys were distributed, pairing is done */
  		if (!smp->local_dist && !smp->remote_dist) {
  			smp_pairing_complete(smp, 0);
  		}
  
  		return;
  	}
  
  #if defined(CONFIG_BT_BREDR)
  	if (conn->type == BT_CONN_TYPE_BR) {
  		struct bt_smp_br *smp;
  
  		chan = bt_l2cap_le_lookup_tx_cid(conn, BT_L2CAP_CID_BR_SMP);
  		__ASSERT(chan, "No SMP channel found");
  
  		smp = CONTAINER_OF(chan, struct bt_smp_br, chan);
  		smp->local_dist &= ~dist_complete;
  
  		/* if all keys were distributed, pairing is done */
  		if (!smp->local_dist && !smp->remote_dist) {
  			smp_pairing_br_complete(smp, 0);
  		}
  	}
  #endif
  }
  #endif
  
  #if defined(CONFIG_BT_PRIVACY)
  static void smp_id_sent(struct bt_conn *conn, void *user_data)
  {
  	smp_check_complete(conn, BT_SMP_DIST_ID_KEY);
  }
  #endif /* CONFIG_BT_PRIVACY */
  
  #if defined(CONFIG_BT_SIGNING)
  static void smp_sign_info_sent(struct bt_conn *conn, void *user_data)
  {
  	smp_check_complete(conn, BT_SMP_DIST_SIGN);
  }
  #endif /* CONFIG_BT_SIGNING */
  
  #if defined(CONFIG_BT_BREDR)
  static int smp_h6(const uint8_t w[16], const uint8_t key_id[4], uint8_t res[16])
  {
  	uint8_t ws[16];
  	uint8_t key_id_s[4];
  	int err;
  
  	BT_DBG("w %s", bt_hex(w, 16));
  	BT_DBG("key_id %s", bt_hex(key_id, 4));
  
  	sys_memcpy_swap(ws, w, 16);
  	sys_memcpy_swap(key_id_s, key_id, 4);
  
  	err = bt_smp_aes_cmac(ws, key_id_s, 4, res);
  	if (err) {
  		return err;
  	}
  
  	BT_DBG("res %s", bt_hex(res, 16));
  
  	sys_mem_swap(res, 16);
  
  	return 0;
  }
  
  static int smp_h7(const uint8_t salt[16], const uint8_t w[16], uint8_t res[16])
  {
  	uint8_t ws[16];
  	uint8_t salt_s[16];
  	int err;
  
  	BT_DBG("w %s", bt_hex(w, 16));
  	BT_DBG("salt %s", bt_hex(salt, 16));
  
  	sys_memcpy_swap(ws, w, 16);
  	sys_memcpy_swap(salt_s, salt, 16);
  
  	err = bt_smp_aes_cmac(salt_s, ws, 16, res);
  	if (err) {
  		return err;
  	}
  
  	BT_DBG("res %s", bt_hex(res, 16));
  
  	sys_mem_swap(res, 16);
  
  	return 0;
  }
  
  static void sc_derive_link_key(struct bt_smp *smp)
  {
  	/* constants as specified in Core Spec Vol.3 Part H 2.4.2.4 */
  	static const uint8_t lebr[4] = { 0x72, 0x62, 0x65, 0x6c };
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_keys_link_key *link_key;
  	uint8_t ilk[16];
  
  	BT_DBG("");
  
  	/* TODO handle errors? */
  
  	/*
  	 * At this point remote device identity is known so we can use
  	 * destination address here
  	 */
  	link_key = bt_keys_get_link_key(&conn->le.dst.a);
  	if (!link_key) {
  		return;
  	}
  
  	if (atomic_test_bit(smp->flags, SMP_FLAG_CT2)) {
  		/* constants as specified in Core Spec Vol.3 Part H 2.4.2.4 */
  		static const uint8_t salt[16] = { 0x31, 0x70, 0x6d, 0x74,
  					       0x00, 0x00, 0x00, 0x00,
  					       0x00, 0x00, 0x00, 0x00,
  					       0x00, 0x00, 0x00, 0x00 };
  
  		if (smp_h7(salt, conn->le.keys->ltk.val, ilk)) {
  			bt_keys_link_key_clear(link_key);
  			return;
  		}
  	} else {
  		/* constants as specified in Core Spec Vol.3 Part H 2.4.2.4 */
  		static const uint8_t tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 };
  
  		if (smp_h6(conn->le.keys->ltk.val, tmp1, ilk)) {
  			bt_keys_link_key_clear(link_key);
  			return;
  		}
  	}
  
  	if (smp_h6(ilk, lebr, link_key->val)) {
  		bt_keys_link_key_clear(link_key);
  	}
  
  	link_key->flags |= BT_LINK_KEY_SC;
  
  	if (conn->le.keys->flags & BT_KEYS_AUTHENTICATED) {
  		link_key->flags |= BT_LINK_KEY_AUTHENTICATED;
  	} else {
  		link_key->flags &= ~BT_LINK_KEY_AUTHENTICATED;
  	}
  }
  
  static void smp_br_reset(struct bt_smp_br *smp)
  {
  	k_delayed_work_cancel(&smp->work);
  
  	atomic_set(smp->flags, 0);
  	atomic_set(smp->allowed_cmds, 0);
  
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_REQ);
  }
  
  static void smp_pairing_br_complete(struct bt_smp_br *smp, uint8_t status)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_keys *keys;
  	bt_addr_le_t addr;
  
  	BT_DBG("status 0x%x", status);
  
  	/* For dualmode devices LE address is same as BR/EDR address
  	 * and is of public type.
  	 */
  	bt_addr_copy(&addr.a, &conn->br.dst);
  	addr.type = BT_ADDR_LE_PUBLIC;
  	keys = bt_keys_find_addr(conn->id, &addr);
  
  	if (status) {
  		if (keys) {
  			bt_keys_clear(keys);
  		}
  
  		if (bt_auth && bt_auth->pairing_failed) {
  			bt_auth->pairing_failed(smp->chan.chan.conn,
  						security_err_get(status));
  		}
  	} else {
  		bool bond_flag = atomic_test_bit(smp->flags, SMP_FLAG_BOND);
  
  		if (bond_flag && keys) {
  			bt_keys_store(keys);
  		}
  
  		if (bt_auth && bt_auth->pairing_complete) {
  			bt_auth->pairing_complete(smp->chan.chan.conn,
  						  bond_flag);
  		}
  	}
  
  	smp_br_reset(smp);
  }
  
  static void smp_br_timeout(struct k_work *work)
  {
  	struct bt_smp_br *smp = CONTAINER_OF(work, struct bt_smp_br, work);
  
  	BT_ERR("SMP Timeout");
  
  	smp_pairing_br_complete(smp, BT_SMP_ERR_UNSPECIFIED);
  	atomic_set_bit(smp->flags, SMP_FLAG_TIMEOUT);
  }
  
  static void smp_br_send(struct bt_smp_br *smp, struct net_buf *buf,
  			bt_conn_tx_cb_t cb)
  {
  	bt_l2cap_send_cb(smp->chan.chan.conn, BT_L2CAP_CID_BR_SMP, buf, cb,
  			 NULL);
  	k_delayed_work_submit(&smp->work, SMP_TIMEOUT);
  }
  
  static void bt_smp_br_connected(struct bt_l2cap_chan *chan)
  {
  	struct bt_smp_br *smp = CONTAINER_OF(chan, struct bt_smp_br, chan);
  
  	BT_DBG("chan %p cid 0x%04x", chan,
  	       CONTAINER_OF(chan, struct bt_l2cap_br_chan, chan)->tx.cid);
  
  	atomic_set_bit(smp->flags, SMP_FLAG_BR_CONNECTED);
  
  	/*
  	 * if this flag is set it means pairing was requested before channel
  	 * was connected
  	 */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_BR_PAIR)) {
  		bt_smp_br_send_pairing_req(chan->conn);
  	}
  }
  
  static void bt_smp_br_disconnected(struct bt_l2cap_chan *chan)
  {
  	struct bt_smp_br *smp = CONTAINER_OF(chan, struct bt_smp_br, chan);
  
  	BT_DBG("chan %p cid 0x%04x", chan,
  	       CONTAINER_OF(chan, struct bt_l2cap_br_chan, chan)->tx.cid);
  
  	k_delayed_work_cancel(&smp->work);
  
  	(void)memset(smp, 0, sizeof(*smp));
  }
  
  static void smp_br_init(struct bt_smp_br *smp)
  {
  	/* Initialize SMP context without clearing L2CAP channel context */
  	(void)memset((uint8_t *)smp + sizeof(smp->chan), 0,
  		     sizeof(*smp) - (sizeof(smp->chan) + sizeof(smp->work)));
  
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_FAIL);
  }
  
  static void smp_br_derive_ltk(struct bt_smp_br *smp)
  {
  	/* constants as specified in Core Spec Vol.3 Part H 2.4.2.5 */
  	static const uint8_t brle[4] = { 0x65, 0x6c, 0x72, 0x62 };
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_keys_link_key *link_key = conn->br.link_key;
  	struct bt_keys *keys;
  	bt_addr_le_t addr;
  	uint8_t ilk[16];
  
  	BT_DBG("");
  
  	if (!link_key) {
  		return;
  	}
  
  	if (IS_ENABLED(CONFIG_BT_SMP_FORCE_BREDR) && conn->encrypt != 0x02) {
  		BT_WARN("Using P192 Link Key for P256 LTK derivation");
  	}
  
  	/*
  	 * For dualmode devices LE address is same as BR/EDR address and is of
  	 * public type.
  	 */
  	bt_addr_copy(&addr.a, &conn->br.dst);
  	addr.type = BT_ADDR_LE_PUBLIC;
  
  	keys = bt_keys_get_type(BT_KEYS_LTK_P256, conn->id, &addr);
  	if (!keys) {
  		BT_ERR("Unable to get keys for %s", bt_addr_le_str(&addr));
  		return;
  	}
  
  	if (atomic_test_bit(smp->flags, SMP_FLAG_CT2)) {
  		/* constants as specified in Core Spec Vol.3 Part H 2.4.2.5 */
  		static const uint8_t salt[16] = { 0x32, 0x70, 0x6d, 0x74,
  					       0x00, 0x00, 0x00, 0x00,
  					       0x00, 0x00, 0x00, 0x00,
  					       0x00, 0x00, 0x00, 0x00 };
  
  		if (smp_h7(salt, link_key->val, ilk)) {
  			bt_keys_link_key_clear(link_key);
  			return;
  		}
  	} else {
  		/* constants as specified in Core Spec Vol.3 Part H 2.4.2.5 */
  		static const uint8_t tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 };
  
  		if (smp_h6(link_key->val, tmp2, ilk)) {
  			bt_keys_clear(keys);
  			return;
  		}
  	}
  
  	if (smp_h6(ilk, brle, keys->ltk.val)) {
  		bt_keys_clear(keys);
  		return;
  	}
  
  	(void)memset(keys->ltk.ediv, 0, sizeof(keys->ltk.ediv));
  	(void)memset(keys->ltk.rand, 0, sizeof(keys->ltk.rand));
  	keys->enc_size = smp->enc_key_size;
  
  	if (link_key->flags & BT_LINK_KEY_AUTHENTICATED) {
  		keys->flags |= BT_KEYS_AUTHENTICATED;
  	} else {
  		keys->flags &= ~BT_KEYS_AUTHENTICATED;
  	}
  
  	BT_DBG("LTK derived from LinkKey");
  }
  
  static struct net_buf *smp_br_create_pdu(struct bt_smp_br *smp, uint8_t op,
  					 size_t len)
  {
  	struct bt_smp_hdr *hdr;
  	struct net_buf *buf;
  	k_timeout_t timeout;
  
  	/* Don't if session had already timed out */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_TIMEOUT)) {
  		timeout = K_NO_WAIT;
  	} else {
  		timeout = SMP_TIMEOUT;
  	}
  
  	/* Use smaller timeout if returning an error since that could be
  	 * caused by lack of buffers.
  	 */
  	buf = bt_l2cap_create_pdu_timeout(NULL, 0, timeout);
  	if (!buf) {
  		/* If it was not possible to allocate a buffer within the
  		 * timeout marked it as timed out.
  		 */
  		atomic_set_bit(smp->flags, SMP_FLAG_TIMEOUT);
  		return NULL;
  	}
  
  	hdr = net_buf_add(buf, sizeof(*hdr));
  	hdr->code = op;
  
  	return buf;
  }
  
  static void smp_br_distribute_keys(struct bt_smp_br *smp)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_keys *keys;
  	bt_addr_le_t addr;
  
  	/*
  	 * For dualmode devices LE address is same as BR/EDR address and is of
  	 * public type.
  	 */
  	bt_addr_copy(&addr.a, &conn->br.dst);
  	addr.type = BT_ADDR_LE_PUBLIC;
  
  	keys = bt_keys_get_addr(conn->id, &addr);
  	if (!keys) {
  		BT_ERR("No keys space for %s", bt_addr_le_str(&addr));
  		return;
  	}
  
  #if defined(CONFIG_BT_PRIVACY)
  	if (smp->local_dist & BT_SMP_DIST_ID_KEY) {
  		struct bt_smp_ident_info *id_info;
  		struct bt_smp_ident_addr_info *id_addr_info;
  		struct net_buf *buf;
  
  		smp->local_dist &= ~BT_SMP_DIST_ID_KEY;
  
  		buf = smp_br_create_pdu(smp, BT_SMP_CMD_IDENT_INFO,
  					sizeof(*id_info));
  		if (!buf) {
  			BT_ERR("Unable to allocate Ident Info buffer");
  			return;
  		}
  
  		id_info = net_buf_add(buf, sizeof(*id_info));
  		memcpy(id_info->irk, bt_dev.irk[conn->id], 16);
  
  		smp_br_send(smp, buf, NULL);
  
  		buf = smp_br_create_pdu(smp, BT_SMP_CMD_IDENT_ADDR_INFO,
  				     sizeof(*id_addr_info));
  		if (!buf) {
  			BT_ERR("Unable to allocate Ident Addr Info buffer");
  			return;
  		}
  
  		id_addr_info = net_buf_add(buf, sizeof(*id_addr_info));
  		bt_addr_le_copy(&id_addr_info->addr, &bt_dev.id_addr[conn->id]);
  
  		smp_br_send(smp, buf, smp_id_sent);
  	}
  #endif /* CONFIG_BT_PRIVACY */
  
  #if defined(CONFIG_BT_SIGNING)
  	if (smp->local_dist & BT_SMP_DIST_SIGN) {
  		struct bt_smp_signing_info *info;
  		struct net_buf *buf;
  
  		smp->local_dist &= ~BT_SMP_DIST_SIGN;
  
  		buf = smp_br_create_pdu(smp, BT_SMP_CMD_SIGNING_INFO,
  					sizeof(*info));
  		if (!buf) {
  			BT_ERR("Unable to allocate Signing Info buffer");
  			return;
  		}
  
  		info = net_buf_add(buf, sizeof(*info));
  
  		if (bt_rand(info->csrk, sizeof(info->csrk))) {
  			BT_ERR("Unable to get random bytes");
  			return;
  		}
  
  		if (atomic_test_bit(smp->flags, SMP_FLAG_BOND)) {
  			bt_keys_add_type(keys, BT_KEYS_LOCAL_CSRK);
  			memcpy(keys->local_csrk.val, info->csrk, 16);
  			keys->local_csrk.cnt = 0U;
  		}
  
  		smp_br_send(smp, buf, smp_sign_info_sent);
  	}
  #endif /* CONFIG_BT_SIGNING */
  }
  
  static bool smp_br_pairing_allowed(struct bt_smp_br *smp)
  {
  	if (smp->chan.chan.conn->encrypt == 0x02) {
  		return true;
  	}
  
  	if (IS_ENABLED(CONFIG_BT_SMP_FORCE_BREDR) &&
  	    smp->chan.chan.conn->encrypt == 0x01) {
  		BT_WARN("Allowing BR/EDR SMP with P-192 key");
  		return true;
  	}
  
  	return false;
  }
  
  static uint8_t smp_br_pairing_req(struct bt_smp_br *smp, struct net_buf *buf)
  {
  	struct bt_smp_pairing *req = (void *)buf->data;
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_smp_pairing *rsp;
  	struct net_buf *rsp_buf;
  	uint8_t max_key_size;
  
  	BT_DBG("");
  
  	/*
  	 * If a Pairing Request is received over the BR/EDR transport when
  	 * either cross-transport key derivation/generation is not supported or
  	 * the BR/EDR transport is not encrypted using a Link Key generated
  	 * using P256, a Pairing Failed shall be sent with the error code
  	 * "Cross-transport Key Derivation/Generation not allowed" (0x0E)."
  	 */
  	if (!smp_br_pairing_allowed(smp)) {
  		return BT_SMP_ERR_CROSS_TRANSP_NOT_ALLOWED;
  	}
  
  	max_key_size = bt_conn_enc_key_size(conn);
  	if (!max_key_size) {
  		BT_DBG("Invalid encryption key size");
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	if (req->max_key_size != max_key_size) {
  		return BT_SMP_ERR_ENC_KEY_SIZE;
  	}
  
  	rsp_buf = smp_br_create_pdu(smp, BT_SMP_CMD_PAIRING_RSP, sizeof(*rsp));
  	if (!rsp_buf) {
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	smp_br_init(smp);
  	smp->enc_key_size = max_key_size;
  
  	/*
  	 * If Secure Connections pairing has been initiated over BR/EDR, the IO
  	 * Capability, OOB data flag and Auth Req fields of the SM Pairing
  	 * Request/Response PDU shall be set to zero on transmission, and
  	 * ignored on reception.
  	 */
  	rsp = net_buf_add(rsp_buf, sizeof(*rsp));
  
  	rsp->auth_req = 0x00;
  	rsp->io_capability = 0x00;
  	rsp->oob_flag = 0x00;
  	rsp->max_key_size = max_key_size;
  	rsp->init_key_dist = (req->init_key_dist & BR_RECV_KEYS_SC);
  	rsp->resp_key_dist = (req->resp_key_dist & BR_RECV_KEYS_SC);
  
  	smp->local_dist = rsp->resp_key_dist;
  	smp->remote_dist = rsp->init_key_dist;
  
  	smp_br_send(smp, rsp_buf, NULL);
  
  	atomic_set_bit(smp->flags, SMP_FLAG_PAIRING);
  
  	/* derive LTK if requested and clear distribution bits */
  	if ((smp->local_dist & BT_SMP_DIST_ENC_KEY) &&
  	    (smp->remote_dist & BT_SMP_DIST_ENC_KEY)) {
  		smp_br_derive_ltk(smp);
  	}
  	smp->local_dist &= ~BT_SMP_DIST_ENC_KEY;
  	smp->remote_dist &= ~BT_SMP_DIST_ENC_KEY;
  
  	/* BR/EDR acceptor is like LE Slave and distributes keys first */
  	smp_br_distribute_keys(smp);
  
  	if (smp->remote_dist & BT_SMP_DIST_ID_KEY) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_IDENT_INFO);
  	} else if (smp->remote_dist & BT_SMP_DIST_SIGN) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_SIGNING_INFO);
  	}
  
  	/* if all keys were distributed, pairing is done */
  	if (!smp->local_dist && !smp->remote_dist) {
  		smp_pairing_br_complete(smp, 0);
  	}
  
  	return 0;
  }
  
  static uint8_t smp_br_pairing_rsp(struct bt_smp_br *smp, struct net_buf *buf)
  {
  	struct bt_smp_pairing *rsp = (void *)buf->data;
  	struct bt_conn *conn = smp->chan.chan.conn;
  	uint8_t max_key_size;
  
  	BT_DBG("");
  
  	max_key_size = bt_conn_enc_key_size(conn);
  	if (!max_key_size) {
  		BT_DBG("Invalid encryption key size");
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	if (rsp->max_key_size != max_key_size) {
  		return BT_SMP_ERR_ENC_KEY_SIZE;
  	}
  
  	smp->local_dist &= rsp->init_key_dist;
  	smp->remote_dist &= rsp->resp_key_dist;
  
  	smp->local_dist &= SEND_KEYS_SC;
  	smp->remote_dist &= RECV_KEYS_SC;
  
  	/* slave distributes its keys first */
  
  	if (smp->remote_dist & BT_SMP_DIST_ID_KEY) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_IDENT_INFO);
  	} else if (smp->remote_dist & BT_SMP_DIST_SIGN) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_SIGNING_INFO);
  	}
  
  	/* derive LTK if requested and clear distribution bits */
  	if ((smp->local_dist & BT_SMP_DIST_ENC_KEY) &&
  	    (smp->remote_dist & BT_SMP_DIST_ENC_KEY)) {
  		smp_br_derive_ltk(smp);
  	}
  	smp->local_dist &= ~BT_SMP_DIST_ENC_KEY;
  	smp->remote_dist &= ~BT_SMP_DIST_ENC_KEY;
  
  	/* Pairing acceptor distributes it's keys first */
  	if (smp->remote_dist) {
  		return 0;
  	}
  
  	smp_br_distribute_keys(smp);
  
  	/* if all keys were distributed, pairing is done */
  	if (!smp->local_dist && !smp->remote_dist) {
  		smp_pairing_br_complete(smp, 0);
  	}
  
  	return 0;
  }
  
  static uint8_t smp_br_pairing_failed(struct bt_smp_br *smp, struct net_buf *buf)
  {
  	struct bt_smp_pairing_fail *req = (void *)buf->data;
  
  	BT_ERR("reason 0x%x", req->reason);
  
  	smp_pairing_br_complete(smp, req->reason);
  	smp_br_reset(smp);
  
  	/* return no error to avoid sending Pairing Failed in response */
  	return 0;
  }
  
  static uint8_t smp_br_ident_info(struct bt_smp_br *smp, struct net_buf *buf)
  {
  	struct bt_smp_ident_info *req = (void *)buf->data;
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_keys *keys;
  	bt_addr_le_t addr;
  
  	BT_DBG("");
  
  	/* TODO should we resolve LE address if matching RPA is connected? */
  
  	/*
  	 * For dualmode devices LE address is same as BR/EDR address and is of
  	 * public type.
  	 */
  	bt_addr_copy(&addr.a, &conn->br.dst);
  	addr.type = BT_ADDR_LE_PUBLIC;
  
  	keys = bt_keys_get_type(BT_KEYS_IRK, conn->id, &addr);
  	if (!keys) {
  		BT_ERR("Unable to get keys for %s", bt_addr_le_str(&addr));
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	memcpy(keys->irk.val, req->irk, sizeof(keys->irk.val));
  
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_IDENT_ADDR_INFO);
  
  	return 0;
  }
  
  static uint8_t smp_br_ident_addr_info(struct bt_smp_br *smp,
  				      struct net_buf *buf)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_smp_ident_addr_info *req = (void *)buf->data;
  	bt_addr_le_t addr;
  
  	BT_DBG("identity %s", bt_addr_le_str(&req->addr));
  
  	/*
  	 * For dual mode device identity address must be same as BR/EDR address
  	 * and be of public type. So if received one doesn't match BR/EDR
  	 * address we fail.
  	 */
  
  	bt_addr_copy(&addr.a, &conn->br.dst);
  	addr.type = BT_ADDR_LE_PUBLIC;
  
  	if (bt_addr_le_cmp(&addr, &req->addr)) {
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	smp->remote_dist &= ~BT_SMP_DIST_ID_KEY;
  
  	if (smp->remote_dist & BT_SMP_DIST_SIGN) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_SIGNING_INFO);
  	}
  
  	if (conn->role == BT_CONN_ROLE_MASTER && !smp->remote_dist) {
  		smp_br_distribute_keys(smp);
  	}
  
  	/* if all keys were distributed, pairing is done */
  	if (!smp->local_dist && !smp->remote_dist) {
  		smp_pairing_br_complete(smp, 0);
  	}
  
  	return 0;
  }
  
  #if defined(CONFIG_BT_SIGNING)
  static uint8_t smp_br_signing_info(struct bt_smp_br *smp, struct net_buf *buf)
  {
  	struct bt_smp_signing_info *req = (void *)buf->data;
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_keys *keys;
  	bt_addr_le_t addr;
  
  	BT_DBG("");
  
  	/*
  	 * For dualmode devices LE address is same as BR/EDR address and is of
  	 * public type.
  	 */
  	bt_addr_copy(&addr.a, &conn->br.dst);
  	addr.type = BT_ADDR_LE_PUBLIC;
  
  	keys = bt_keys_get_type(BT_KEYS_REMOTE_CSRK, conn->id, &addr);
  	if (!keys) {
  		BT_ERR("Unable to get keys for %s", bt_addr_le_str(&addr));
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	memcpy(keys->remote_csrk.val, req->csrk, sizeof(keys->remote_csrk.val));
  
  	smp->remote_dist &= ~BT_SMP_DIST_SIGN;
  
  	if (conn->role == BT_CONN_ROLE_MASTER && !smp->remote_dist) {
  		smp_br_distribute_keys(smp);
  	}
  
  	/* if all keys were distributed, pairing is done */
  	if (!smp->local_dist && !smp->remote_dist) {
  		smp_pairing_br_complete(smp, 0);
  	}
  
  	return 0;
  }
  #else
  static uint8_t smp_br_signing_info(struct bt_smp_br *smp, struct net_buf *buf)
  {
  	return BT_SMP_ERR_CMD_NOTSUPP;
  }
  #endif /* CONFIG_BT_SIGNING */
  
  static const struct {
  	uint8_t  (*func)(struct bt_smp_br *smp, struct net_buf *buf);
  	uint8_t  expect_len;
  } br_handlers[] = {
  	{ }, /* No op-code defined for 0x00 */
  	{ smp_br_pairing_req,      sizeof(struct bt_smp_pairing) },
  	{ smp_br_pairing_rsp,      sizeof(struct bt_smp_pairing) },
  	{ }, /* pairing confirm not used over BR/EDR */
  	{ }, /* pairing random not used over BR/EDR */
  	{ smp_br_pairing_failed,   sizeof(struct bt_smp_pairing_fail) },
  	{ }, /* encrypt info not used over BR/EDR */
  	{ }, /* master ident not used over BR/EDR */
  	{ smp_br_ident_info,       sizeof(struct bt_smp_ident_info) },
  	{ smp_br_ident_addr_info,  sizeof(struct bt_smp_ident_addr_info) },
  	{ smp_br_signing_info,     sizeof(struct bt_smp_signing_info) },
  	/* security request not used over BR/EDR */
  	/* public key not used over BR/EDR */
  	/* DHKey check not used over BR/EDR */
  };
  
  static int smp_br_error(struct bt_smp_br *smp, uint8_t reason)
  {
  	struct bt_smp_pairing_fail *rsp;
  	struct net_buf *buf;
  
  	/* reset context and report */
  	smp_br_reset(smp);
  
  	buf = smp_br_create_pdu(smp, BT_SMP_CMD_PAIRING_FAIL, sizeof(*rsp));
  	if (!buf) {
  		return -ENOBUFS;
  	}
  
  	rsp = net_buf_add(buf, sizeof(*rsp));
  	rsp->reason = reason;
  
  	/*
  	 * SMP timer is not restarted for PairingFailed so don't use
  	 * smp_br_send
  	 */
  	bt_l2cap_send(smp->chan.chan.conn, BT_L2CAP_CID_SMP, buf);
  
  	return 0;
  }
  
  static int bt_smp_br_recv(struct bt_l2cap_chan *chan, struct net_buf *buf)
  {
  	struct bt_smp_br *smp = CONTAINER_OF(chan, struct bt_smp_br, chan);
  	struct bt_smp_hdr *hdr;
  	uint8_t err;
  
  	if (buf->len < sizeof(*hdr)) {
  		BT_ERR("Too small SMP PDU received");
  		return 0;
  	}
  
  	hdr = net_buf_pull_mem(buf, sizeof(*hdr));
  	BT_DBG("Received SMP code 0x%02x len %u", hdr->code, buf->len);
  
  	/*
  	 * If SMP timeout occurred "no further SMP commands shall be sent over
  	 * the L2CAP Security Manager Channel. A new SM procedure shall only be
  	 * performed when a new physical link has been established."
  	 */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_TIMEOUT)) {
  		BT_WARN("SMP command (code 0x%02x) received after timeout",
  			hdr->code);
  		return 0;
  	}
  
  	if (hdr->code >= ARRAY_SIZE(br_handlers) ||
  	    !br_handlers[hdr->code].func) {
  		BT_WARN("Unhandled SMP code 0x%02x", hdr->code);
  		smp_br_error(smp, BT_SMP_ERR_CMD_NOTSUPP);
  		return 0;
  	}
  
  	if (!atomic_test_and_clear_bit(smp->allowed_cmds, hdr->code)) {
  		BT_WARN("Unexpected SMP code 0x%02x", hdr->code);
  		smp_br_error(smp, BT_SMP_ERR_UNSPECIFIED);
  		return 0;
  	}
  
  	if (buf->len != br_handlers[hdr->code].expect_len) {
  		BT_ERR("Invalid len %u for code 0x%02x", buf->len, hdr->code);
  		smp_br_error(smp, BT_SMP_ERR_INVALID_PARAMS);
  		return 0;
  	}
  
  	err = br_handlers[hdr->code].func(smp, buf);
  	if (err) {
  		smp_br_error(smp, err);
  	}
  
  	return 0;
  }
  
  static bool br_sc_supported(void)
  {
  	if (IS_ENABLED(CONFIG_BT_SMP_FORCE_BREDR)) {
  		BT_WARN("Enabling BR/EDR SMP without BR/EDR SC support");
  		return true;
  	}
  
  	return BT_FEAT_SC(bt_dev.features);
  }
  
  static int bt_smp_br_accept(struct bt_conn *conn, struct bt_l2cap_chan **chan)
  {
  	static const struct bt_l2cap_chan_ops ops = {
  		.connected = bt_smp_br_connected,
  		.disconnected = bt_smp_br_disconnected,
  		.recv = bt_smp_br_recv,
  	};
  	int i;
  
  	/* Check BR/EDR SC is supported */
  	if (!br_sc_supported()) {
  		return -ENOTSUP;
  	}
  
  	BT_DBG("conn %p handle %u", conn, conn->handle);
  
  	for (i = 0; i < ARRAY_SIZE(bt_smp_pool); i++) {
  		struct bt_smp_br *smp = &bt_smp_br_pool[i];
  
  		if (smp->chan.chan.conn) {
  			continue;
  		}
  
  		smp->chan.chan.ops = &ops;
  
  		*chan = &smp->chan.chan;
  
  		k_delayed_work_init(&smp->work, smp_br_timeout);
  		smp_br_reset(smp);
  
  		return 0;
  	}
  
  	BT_ERR("No available SMP context for conn %p", conn);
  
  	return -ENOMEM;
  }
  
  static struct bt_smp_br *smp_br_chan_get(struct bt_conn *conn)
  {
  	struct bt_l2cap_chan *chan;
  
  	chan = bt_l2cap_br_lookup_rx_cid(conn, BT_L2CAP_CID_BR_SMP);
  	if (!chan) {
  		BT_ERR("Unable to find SMP channel");
  		return NULL;
  	}
  
  	return CONTAINER_OF(chan, struct bt_smp_br, chan);
  }
  
  int bt_smp_br_send_pairing_req(struct bt_conn *conn)
  {
  	struct bt_smp_pairing *req;
  	struct net_buf *req_buf;
  	uint8_t max_key_size;
  	struct bt_smp_br *smp;
  
  	smp = smp_br_chan_get(conn);
  	if (!smp) {
  		return -ENOTCONN;
  	}
  
  	/* SMP Timeout */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_TIMEOUT)) {
  		return -EIO;
  	}
  
  	/* pairing is in progress */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_PAIRING)) {
  		return -EBUSY;
  	}
  
  	/* check if we are allowed to start SMP over BR/EDR */
  	if (!smp_br_pairing_allowed(smp)) {
  		return 0;
  	}
  
  	/* Channel not yet connected, will start pairing once connected */
  	if (!atomic_test_bit(smp->flags, SMP_FLAG_BR_CONNECTED)) {
  		atomic_set_bit(smp->flags, SMP_FLAG_BR_PAIR);
  		return 0;
  	}
  
  	max_key_size = bt_conn_enc_key_size(conn);
  	if (!max_key_size) {
  		BT_DBG("Invalid encryption key size");
  		return -EIO;
  	}
  
  	smp_br_init(smp);
  	smp->enc_key_size = max_key_size;
  
  	req_buf = smp_br_create_pdu(smp, BT_SMP_CMD_PAIRING_REQ, sizeof(*req));
  	if (!req_buf) {
  		return -ENOBUFS;
  	}
  
  	req = net_buf_add(req_buf, sizeof(*req));
  
  	/*
  	 * If Secure Connections pairing has been initiated over BR/EDR, the IO
  	 * Capability, OOB data flag and Auth Req fields of the SM Pairing
  	 * Request/Response PDU shall be set to zero on transmission, and
  	 * ignored on reception.
  	 */
  
  	req->auth_req = 0x00;
  	req->io_capability = 0x00;
  	req->oob_flag = 0x00;
  	req->max_key_size = max_key_size;
  	req->init_key_dist = BR_SEND_KEYS_SC;
  	req->resp_key_dist = BR_RECV_KEYS_SC;
  
  	smp_br_send(smp, req_buf, NULL);
  
  	smp->local_dist = BR_SEND_KEYS_SC;
  	smp->remote_dist = BR_RECV_KEYS_SC;
  
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_RSP);
  
  	atomic_set_bit(smp->flags, SMP_FLAG_PAIRING);
  
  	return 0;
  }
  #endif /* CONFIG_BT_BREDR */
  
  static void smp_reset(struct bt_smp *smp)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  
  	k_delayed_work_cancel(&smp->work);
  
  	smp->method = JUST_WORKS;
  	atomic_set(smp->allowed_cmds, 0);
  	atomic_set(smp->flags, 0);
  
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    conn->role == BT_HCI_ROLE_MASTER) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_SECURITY_REQUEST);
  		return;
  	}
  
  	if (IS_ENABLED(CONFIG_BT_PERIPHERAL)) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_REQ);
  	}
  }
  
  static uint8_t hci_err_get(enum bt_security_err err)
  {
  	switch (err) {
  	case BT_SECURITY_ERR_SUCCESS:
  		return BT_HCI_ERR_SUCCESS;
  	case BT_SECURITY_ERR_AUTH_FAIL:
  		return BT_HCI_ERR_AUTH_FAIL;
  	case BT_SECURITY_ERR_PIN_OR_KEY_MISSING:
  		return BT_HCI_ERR_PIN_OR_KEY_MISSING;
  	case BT_SECURITY_ERR_PAIR_NOT_SUPPORTED:
  		return BT_HCI_ERR_PAIRING_NOT_SUPPORTED;
  	case BT_SECURITY_ERR_PAIR_NOT_ALLOWED:
  		return BT_HCI_ERR_PAIRING_NOT_ALLOWED;
  	case BT_SECURITY_ERR_INVALID_PARAM:
  		return BT_HCI_ERR_INVALID_PARAM;
  	default:
  		return BT_HCI_ERR_UNSPECIFIED;
  	}
  }
  
  /* Note: This function not only does set the status but also calls smp_reset
   * at the end which clears any flags previously set.
   */
  static void smp_pairing_complete(struct bt_smp *smp, uint8_t status)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  
  	BT_DBG("status 0x%x", status);
  
  	if (!status) {
  #if defined(CONFIG_BT_BREDR)
  		/*
  		 * Don't derive if Debug Keys are used.
  		 * TODO should we allow this if BR/EDR is already connected?
  		 */
  		if (atomic_test_bit(smp->flags, SMP_FLAG_DERIVE_LK) &&
  		    (!atomic_test_bit(smp->flags, SMP_FLAG_SC_DEBUG_KEY) ||
  		     IS_ENABLED(CONFIG_BT_STORE_DEBUG_KEYS))) {
  			sc_derive_link_key(smp);
  		}
  #endif /* CONFIG_BT_BREDR */
  		bool bond_flag = atomic_test_bit(smp->flags, SMP_FLAG_BOND);
  
  		if (IS_ENABLED(CONFIG_BT_LOG_SNIFFER_INFO)) {
  			bt_keys_show_sniffer_info(conn->le.keys, NULL);
  		}
  
  		if (bond_flag) {
  			bt_keys_store(conn->le.keys);
  		}
  
  		if (bt_auth && bt_auth->pairing_complete) {
  			bt_auth->pairing_complete(conn, bond_flag);
  		}
  	} else {
  		enum bt_security_err security_err = security_err_get(status);
  
  		/* Clear the key pool entry in case of pairing failure if the
  		 * keys already existed before the pairing procedure or the
  		 * pairing failed during key distribution.
  		 */
  		if (conn->le.keys &&
  		    (!conn->le.keys->enc_size ||
  		     atomic_test_bit(smp->flags, SMP_FLAG_KEYS_DISTR))) {
  			bt_keys_clear(conn->le.keys);
  			conn->le.keys = NULL;
  		}
  
  		if (!atomic_test_bit(smp->flags, SMP_FLAG_KEYS_DISTR)) {
  			bt_conn_security_changed(conn,
  						 hci_err_get(security_err),
  						 security_err);
  		}
  
  		if (bt_auth && bt_auth->pairing_failed) {
  			bt_auth->pairing_failed(conn, security_err);
  		}
  	}
  
  	smp_reset(smp);
  
  	if (conn->sec_level != conn->required_sec_level) {
  		bt_smp_start_security(conn);
  	}
  }
  
  static void smp_timeout(struct k_work *work)
  {
  	struct bt_smp *smp = CONTAINER_OF(work, struct bt_smp, work);
  
  	BT_ERR("SMP Timeout");
  
  	smp_pairing_complete(smp, BT_SMP_ERR_UNSPECIFIED);
  
  	/* smp_pairing_complete clears flags so setting timeout flag must come
  	 * after it.
  	 */
  	atomic_set_bit(smp->flags, SMP_FLAG_TIMEOUT);
  }
  
  static void smp_send(struct bt_smp *smp, struct net_buf *buf,
  		     bt_conn_tx_cb_t cb, void *user_data)
  {
  	bt_l2cap_send_cb(smp->chan.chan.conn, BT_L2CAP_CID_SMP, buf, cb, NULL);
  	k_delayed_work_submit(&smp->work, SMP_TIMEOUT);
  }
  
  static int smp_error(struct bt_smp *smp, uint8_t reason)
  {
  	struct bt_smp_pairing_fail *rsp;
  	struct net_buf *buf;
  
  	if (atomic_test_bit(smp->flags, SMP_FLAG_PAIRING) ||
  	    atomic_test_bit(smp->flags, SMP_FLAG_ENC_PENDING) ||
  	    atomic_test_bit(smp->flags, SMP_FLAG_SEC_REQ)) {
  		/* reset context and report */
  		smp_pairing_complete(smp, reason);
  	}
  
  	buf = smp_create_pdu(smp, BT_SMP_CMD_PAIRING_FAIL, sizeof(*rsp));
  	if (!buf) {
  		return -ENOBUFS;
  	}
  
  	rsp = net_buf_add(buf, sizeof(*rsp));
  	rsp->reason = reason;
  
  	/* SMP timer is not restarted for PairingFailed so don't use smp_send */
  	bt_l2cap_send(smp->chan.chan.conn, BT_L2CAP_CID_SMP, buf);
  
  	return 0;
  }
  
  static uint8_t smp_send_pairing_random(struct bt_smp *smp)
  {
  	struct bt_smp_pairing_random *req;
  	struct net_buf *rsp_buf;
  
  	rsp_buf = smp_create_pdu(smp, BT_SMP_CMD_PAIRING_RANDOM, sizeof(*req));
  	if (!rsp_buf) {
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	req = net_buf_add(rsp_buf, sizeof(*req));
  	memcpy(req->val, smp->prnd, sizeof(req->val));
  
  	smp_send(smp, rsp_buf, NULL, NULL);
  
  	return 0;
  }
  
  #if !defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
  static void xor_128(const uint8_t p[16], const uint8_t q[16], uint8_t r[16])
  {
  	size_t len = 16;
  
  	while (len--) {
  		*r++ = *p++ ^ *q++;
  	}
  }
  
  static int smp_c1(const uint8_t k[16], const uint8_t r[16],
  		  const uint8_t preq[7], const uint8_t pres[7],
  		  const bt_addr_le_t *ia, const bt_addr_le_t *ra,
  		  uint8_t enc_data[16])
  {
  	uint8_t p1[16], p2[16];
  	int err;
  
  	BT_DBG("k %s", bt_hex(k, 16));
  	BT_DBG("r %s", bt_hex(r, 16));
  	BT_DBG("ia %s", bt_addr_le_str(ia));
  	BT_DBG("ra %s", bt_addr_le_str(ra));
  	BT_DBG("preq %s", bt_hex(preq, 7));
  	BT_DBG("pres %s", bt_hex(pres, 7));
  
  	/* pres, preq, rat and iat are concatenated to generate p1 */
  	p1[0] = ia->type;
  	p1[1] = ra->type;
  	memcpy(p1 + 2, preq, 7);
  	memcpy(p1 + 9, pres, 7);
  
  	BT_DBG("p1 %s", bt_hex(p1, 16));
  
  	/* c1 = e(k, e(k, r XOR p1) XOR p2) */
  
  	/* Using enc_data as temporary output buffer */
  	xor_128(r, p1, enc_data);
  
  	err = bt_encrypt_le(k, enc_data, enc_data);
  	if (err) {
  		return err;
  	}
  
  	/* ra is concatenated with ia and padding to generate p2 */
  	memcpy(p2, ra->a.val, 6);
  	memcpy(p2 + 6, ia->a.val, 6);
  	(void)memset(p2 + 12, 0, 4);
  
  	BT_DBG("p2 %s", bt_hex(p2, 16));
  
  	xor_128(enc_data, p2, enc_data);
  
  	return bt_encrypt_le(k, enc_data, enc_data);
  }
  #endif /* !CONFIG_BT_SMP_SC_PAIR_ONLY */
  
  static uint8_t smp_send_pairing_confirm(struct bt_smp *smp)
  {
  	struct bt_smp_pairing_confirm *req;
  	struct net_buf *buf;
  	uint8_t r;
  
  	switch (smp->method) {
  	case PASSKEY_CONFIRM:
  	case JUST_WORKS:
  		r = 0U;
  		break;
  	case PASSKEY_DISPLAY:
  	case PASSKEY_INPUT:
  		/*
  		 * In the Passkey Entry protocol, the most significant
  		 * bit of Z is set equal to one and the least
  		 * significant bit is made up from one bit of the
  		 * passkey e.g. if the passkey bit is 1, then Z = 0x81
  		 * and if the passkey bit is 0, then Z = 0x80.
  		 */
  		r = (smp->passkey >> smp->passkey_round) & 0x01;
  		r |= 0x80;
  		break;
  	default:
  		BT_ERR("Unknown pairing method (%u)", smp->method);
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	buf = smp_create_pdu(smp, BT_SMP_CMD_PAIRING_CONFIRM, sizeof(*req));
  	if (!buf) {
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	req = net_buf_add(buf, sizeof(*req));
  
  	if (smp_f4(sc_public_key, smp->pkey, smp->prnd, r, req->val)) {
  		net_buf_unref(buf);
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	smp_send(smp, buf, NULL, NULL);
  
  	atomic_clear_bit(smp->flags, SMP_FLAG_CFM_DELAYED);
  
  	return 0;
  }
  
  #if !defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
  static void smp_ident_sent(struct bt_conn *conn, void *user_data)
  {
  	smp_check_complete(conn, BT_SMP_DIST_ENC_KEY);
  }
  
  static void legacy_distribute_keys(struct bt_smp *smp)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_keys *keys = conn->le.keys;
  
  	if (smp->local_dist & BT_SMP_DIST_ENC_KEY) {
  		struct bt_smp_encrypt_info *info;
  		struct bt_smp_master_ident *ident;
  		struct net_buf *buf;
  		/* Use struct to get randomness in single call to bt_rand */
  		struct {
  			uint8_t key[16];
  			uint8_t rand[8];
  			uint8_t ediv[2];
  		} rand;
  
  		if (bt_rand((void *)&rand, sizeof(rand))) {
  			BT_ERR("Unable to get random bytes");
  			return;
  		}
  
  		buf = smp_create_pdu(smp, BT_SMP_CMD_ENCRYPT_INFO,
  				     sizeof(*info));
  		if (!buf) {
  			BT_ERR("Unable to allocate Encrypt Info buffer");
  			return;
  		}
  
  		info = net_buf_add(buf, sizeof(*info));
  
  		/* distributed only enc_size bytes of key */
  		memcpy(info->ltk, rand.key, keys->enc_size);
  		if (keys->enc_size < sizeof(info->ltk)) {
  			(void)memset(info->ltk + keys->enc_size, 0,
  				     sizeof(info->ltk) - keys->enc_size);
  		}
  
  		smp_send(smp, buf, NULL, NULL);
  
  		buf = smp_create_pdu(smp, BT_SMP_CMD_MASTER_IDENT,
  				     sizeof(*ident));
  		if (!buf) {
  			BT_ERR("Unable to allocate Master Ident buffer");
  			return;
  		}
  
  		ident = net_buf_add(buf, sizeof(*ident));
  		memcpy(ident->rand, rand.rand, sizeof(ident->rand));
  		memcpy(ident->ediv, rand.ediv, sizeof(ident->ediv));
  
  		smp_send(smp, buf, smp_ident_sent, NULL);
  
  		if (atomic_test_bit(smp->flags, SMP_FLAG_BOND)) {
  			bt_keys_add_type(keys, BT_KEYS_SLAVE_LTK);
  
  			memcpy(keys->slave_ltk.val, rand.key,
  			       sizeof(keys->slave_ltk.val));
  			memcpy(keys->slave_ltk.rand, rand.rand,
  			       sizeof(keys->slave_ltk.rand));
  			memcpy(keys->slave_ltk.ediv, rand.ediv,
  			       sizeof(keys->slave_ltk.ediv));
  		}
  	}
  }
  #endif /* !CONFIG_BT_SMP_SC_PAIR_ONLY */
  
  static uint8_t bt_smp_distribute_keys(struct bt_smp *smp)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_keys *keys = conn->le.keys;
  
  	if (!keys) {
  		BT_ERR("No keys space for %s", bt_addr_le_str(&conn->le.dst));
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  #if !defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
  	/* Distribute legacy pairing specific keys */
  	if (!atomic_test_bit(smp->flags, SMP_FLAG_SC)) {
  		legacy_distribute_keys(smp);
  	}
  #endif /* !CONFIG_BT_SMP_SC_PAIR_ONLY */
  
  #if defined(CONFIG_BT_PRIVACY)
  	if (smp->local_dist & BT_SMP_DIST_ID_KEY) {
  		struct bt_smp_ident_info *id_info;
  		struct bt_smp_ident_addr_info *id_addr_info;
  		struct net_buf *buf;
  
  		buf = smp_create_pdu(smp, BT_SMP_CMD_IDENT_INFO,
  				     sizeof(*id_info));
  		if (!buf) {
  			BT_ERR("Unable to allocate Ident Info buffer");
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		id_info = net_buf_add(buf, sizeof(*id_info));
  		memcpy(id_info->irk, bt_dev.irk[conn->id], 16);
  
  		smp_send(smp, buf, NULL, NULL);
  
  		buf = smp_create_pdu(smp, BT_SMP_CMD_IDENT_ADDR_INFO,
  				     sizeof(*id_addr_info));
  		if (!buf) {
  			BT_ERR("Unable to allocate Ident Addr Info buffer");
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		id_addr_info = net_buf_add(buf, sizeof(*id_addr_info));
  		bt_addr_le_copy(&id_addr_info->addr, &bt_dev.id_addr[conn->id]);
  
  		smp_send(smp, buf, smp_id_sent, NULL);
  	}
  #endif /* CONFIG_BT_PRIVACY */
  
  #if defined(CONFIG_BT_SIGNING)
  	if (smp->local_dist & BT_SMP_DIST_SIGN) {
  		struct bt_smp_signing_info *info;
  		struct net_buf *buf;
  
  		buf = smp_create_pdu(smp, BT_SMP_CMD_SIGNING_INFO,
  				     sizeof(*info));
  		if (!buf) {
  			BT_ERR("Unable to allocate Signing Info buffer");
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		info = net_buf_add(buf, sizeof(*info));
  
  		if (bt_rand(info->csrk, sizeof(info->csrk))) {
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		if (atomic_test_bit(smp->flags, SMP_FLAG_BOND)) {
  			bt_keys_add_type(keys, BT_KEYS_LOCAL_CSRK);
  			memcpy(keys->local_csrk.val, info->csrk, 16);
  			keys->local_csrk.cnt = 0U;
  		}
  
  		smp_send(smp, buf, smp_sign_info_sent, NULL);
  	}
  #endif /* CONFIG_BT_SIGNING */
  
  	return 0;
  }
  
  #if defined(CONFIG_BT_PERIPHERAL)
  static uint8_t send_pairing_rsp(struct bt_smp *smp)
  {
  	struct bt_smp_pairing *rsp;
  	struct net_buf *rsp_buf;
  
  	rsp_buf = smp_create_pdu(smp, BT_SMP_CMD_PAIRING_RSP, sizeof(*rsp));
  	if (!rsp_buf) {
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	rsp = net_buf_add(rsp_buf, sizeof(*rsp));
  	memcpy(rsp, smp->prsp + 1, sizeof(*rsp));
  
  	smp_send(smp, rsp_buf, NULL, NULL);
  
  	return 0;
  }
  #endif /* CONFIG_BT_PERIPHERAL */
  
  static uint8_t smp_pairing_accept_query(struct bt_conn *conn,
  				    struct bt_smp_pairing *pairing)
  {
  #if defined(CONFIG_BT_SMP_APP_PAIRING_ACCEPT)
  	if (bt_auth && bt_auth->pairing_accept) {
  		const struct bt_conn_pairing_feat feat = {
  			.io_capability = pairing->io_capability,
  			.oob_data_flag = pairing->oob_flag,
  			.auth_req = pairing->auth_req,
  			.max_enc_key_size = pairing->max_key_size,
  			.init_key_dist = pairing->init_key_dist,
  			.resp_key_dist = pairing->resp_key_dist
  		};
  
  		return smp_err_get(bt_auth->pairing_accept(conn, &feat));
  	}
  #endif /* CONFIG_BT_SMP_APP_PAIRING_ACCEPT */
  	return 0;
  }
  
  #if !defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
  static int smp_s1(const uint8_t k[16], const uint8_t r1[16],
  		  const uint8_t r2[16], uint8_t out[16])
  {
  	/* The most significant 64-bits of r1 are discarded to generate
  	 * r1' and the most significant 64-bits of r2 are discarded to
  	 * generate r2'.
  	 * r1' is concatenated with r2' to generate r' which is used as
  	 * the 128-bit input parameter plaintextData to security function e:
  	 *
  	 *    r' = r1' || r2'
  	 */
  	memcpy(out, r2, 8);
  	memcpy(out + 8, r1, 8);
  
  	/* s1(k, r1 , r2) = e(k, r') */
  	return bt_encrypt_le(k, out, out);
  }
  
  static uint8_t legacy_get_pair_method(struct bt_smp *smp, uint8_t remote_io)
  {
  	struct bt_smp_pairing *req, *rsp;
  	uint8_t method;
  
  	if (remote_io > BT_SMP_IO_KEYBOARD_DISPLAY) {
  		return JUST_WORKS;
  	}
  
  	req = (struct bt_smp_pairing *)&smp->preq[1];
  	rsp = (struct bt_smp_pairing *)&smp->prsp[1];
  
  	/* if both sides have OOB data use OOB */
  	if ((req->oob_flag & rsp->oob_flag) & BT_SMP_OOB_DATA_MASK) {
  		return LEGACY_OOB;
  	}
  
  	/* if none side requires MITM use JustWorks */
  	if (!((req->auth_req | rsp->auth_req) & BT_SMP_AUTH_MITM)) {
  		return JUST_WORKS;
  	}
  
  	method = gen_method_legacy[remote_io][get_io_capa()];
  
  	/* if both sides have KeyboardDisplay capabilities, initiator displays
  	 * and responder inputs
  	 */
  	if (method == PASSKEY_ROLE) {
  		if (smp->chan.chan.conn->role == BT_HCI_ROLE_MASTER) {
  			method = PASSKEY_DISPLAY;
  		} else {
  			method = PASSKEY_INPUT;
  		}
  	}
  
  	return method;
  }
  
  static uint8_t legacy_request_tk(struct bt_smp *smp)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_keys *keys;
  	uint32_t passkey;
  
  	/*
  	 * Fail if we have keys that are stronger than keys that will be
  	 * distributed in new pairing. This is to avoid replacing authenticated
  	 * keys with unauthenticated ones.
  	  */
  	keys = bt_keys_find_addr(conn->id, &conn->le.dst);
  	if (keys && (keys->flags & BT_KEYS_AUTHENTICATED) &&
  	    smp->method == JUST_WORKS) {
  		BT_ERR("JustWorks failed, authenticated keys present");
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	switch (smp->method) {
  	case LEGACY_OOB:
  		if (bt_auth && bt_auth->oob_data_request) {
  			struct bt_conn_oob_info info = {
  				.type = BT_CONN_OOB_LE_LEGACY,
  			};
  
  			atomic_set_bit(smp->flags, SMP_FLAG_USER);
  			bt_auth->oob_data_request(smp->chan.chan.conn, &info);
  		} else {
  			return BT_SMP_ERR_OOB_NOT_AVAIL;
  		}
  
  		break;
  	case PASSKEY_DISPLAY:
  		if (IS_ENABLED(CONFIG_BT_FIXED_PASSKEY) &&
  		    fixed_passkey != BT_PASSKEY_INVALID) {
  			passkey = fixed_passkey;
  		} else  {
  			if (bt_rand(&passkey, sizeof(passkey))) {
  				return BT_SMP_ERR_UNSPECIFIED;
  			}
  
  			passkey %= 1000000;
  		}
  
  		if (IS_ENABLED(CONFIG_BT_LOG_SNIFFER_INFO)) {
  			BT_INFO("Legacy passkey %u", passkey);
  		}
  
  		if (bt_auth && bt_auth->passkey_display) {
  			atomic_set_bit(smp->flags, SMP_FLAG_DISPLAY);
  			bt_auth->passkey_display(conn, passkey);
  		}
  
  		sys_put_le32(passkey, smp->tk);
  
  		break;
  	case PASSKEY_INPUT:
  		atomic_set_bit(smp->flags, SMP_FLAG_USER);
  		bt_auth->passkey_entry(conn);
  		break;
  	case JUST_WORKS:
  		break;
  	default:
  		BT_ERR("Unknown pairing method (%u)", smp->method);
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	return 0;
  }
  
  static uint8_t legacy_send_pairing_confirm(struct bt_smp *smp)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_smp_pairing_confirm *req;
  	struct net_buf *buf;
  
  	buf = smp_create_pdu(smp, BT_SMP_CMD_PAIRING_CONFIRM, sizeof(*req));
  	if (!buf) {
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	req = net_buf_add(buf, sizeof(*req));
  
  	if (smp_c1(smp->tk, smp->prnd, smp->preq, smp->prsp,
  		   &conn->le.init_addr, &conn->le.resp_addr, req->val)) {
  		net_buf_unref(buf);
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	smp_send(smp, buf, NULL, NULL);
  
  	atomic_clear_bit(smp->flags, SMP_FLAG_CFM_DELAYED);
  
  	return 0;
  }
  
  #if defined(CONFIG_BT_PERIPHERAL)
  static uint8_t legacy_pairing_req(struct bt_smp *smp)
  {
  	uint8_t ret;
  
  	BT_DBG("");
  
  	ret = legacy_request_tk(smp);
  	if (ret) {
  		return ret;
  	}
  
  	/* ask for consent if pairing is not due to sending SecReq*/
  	if ((DISPLAY_FIXED(smp) || smp->method == JUST_WORKS) &&
  	    !atomic_test_bit(smp->flags, SMP_FLAG_SEC_REQ) &&
  	    bt_auth && bt_auth->pairing_confirm) {
  		atomic_set_bit(smp->flags, SMP_FLAG_USER);
  		bt_auth->pairing_confirm(smp->chan.chan.conn);
  		return 0;
  	}
  
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_CONFIRM);
  	return send_pairing_rsp(smp);
  }
  #endif /* CONFIG_BT_PERIPHERAL */
  
  static uint8_t legacy_pairing_random(struct bt_smp *smp)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  	uint8_t tmp[16];
  	int err;
  
  	BT_DBG("");
  
  	/* calculate confirmation */
  	err = smp_c1(smp->tk, smp->rrnd, smp->preq, smp->prsp,
  		     &conn->le.init_addr, &conn->le.resp_addr, tmp);
  	if (err) {
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	BT_DBG("pcnf %s", bt_hex(smp->pcnf, 16));
  	BT_DBG("cfm %s", bt_hex(tmp, 16));
  
  	if (memcmp(smp->pcnf, tmp, sizeof(smp->pcnf))) {
  		return BT_SMP_ERR_CONFIRM_FAILED;
  	}
  
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    conn->role == BT_HCI_ROLE_MASTER) {
  		uint8_t ediv[2], rand[8];
  
  		/* No need to store master STK */
  		err = smp_s1(smp->tk, smp->rrnd, smp->prnd, tmp);
  		if (err) {
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		/* Rand and EDiv are 0 for the STK */
  		(void)memset(ediv, 0, sizeof(ediv));
  		(void)memset(rand, 0, sizeof(rand));
  		if (bt_conn_le_start_encryption(conn, rand, ediv, tmp,
  						get_encryption_key_size(smp))) {
  			BT_ERR("Failed to start encryption");
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		atomic_set_bit(smp->flags, SMP_FLAG_ENC_PENDING);
  
  		if (IS_ENABLED(CONFIG_BT_SMP_USB_HCI_CTLR_WORKAROUND)) {
  			if (smp->remote_dist & BT_SMP_DIST_ENC_KEY) {
  				atomic_set_bit(smp->allowed_cmds,
  					       BT_SMP_CMD_ENCRYPT_INFO);
  			} else if (smp->remote_dist & BT_SMP_DIST_ID_KEY) {
  				atomic_set_bit(smp->allowed_cmds,
  					       BT_SMP_CMD_IDENT_INFO);
  			} else if (smp->remote_dist & BT_SMP_DIST_SIGN) {
  				atomic_set_bit(smp->allowed_cmds,
  					       BT_SMP_CMD_SIGNING_INFO);
  			}
  		}
  
  		return 0;
  	}
  
  	if (IS_ENABLED(CONFIG_BT_PERIPHERAL)) {
  		err = smp_s1(smp->tk, smp->prnd, smp->rrnd, tmp);
  		if (err) {
  			BT_ERR("Calculate STK failed");
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		memcpy(smp->tk, tmp, sizeof(smp->tk));
  		BT_DBG("generated STK %s", bt_hex(smp->tk, 16));
  
  		atomic_set_bit(smp->flags, SMP_FLAG_ENC_PENDING);
  
  		return smp_send_pairing_random(smp);
  	}
  
  	return 0;
  }
  
  static uint8_t legacy_pairing_confirm(struct bt_smp *smp)
  {
  	BT_DBG("");
  
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    smp->chan.chan.conn->role == BT_HCI_ROLE_MASTER) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_CONFIRM);
  		return legacy_send_pairing_confirm(smp);
  	}
  
  	if (IS_ENABLED(CONFIG_BT_PERIPHERAL)) {
  		if (!atomic_test_bit(smp->flags, SMP_FLAG_USER)) {
  			atomic_set_bit(smp->allowed_cmds,
  				       BT_SMP_CMD_PAIRING_RANDOM);
  			return legacy_send_pairing_confirm(smp);
  		}
  
  		atomic_set_bit(smp->flags, SMP_FLAG_CFM_DELAYED);
  	}
  
  	return 0;
  }
  
  static void legacy_user_tk_entry(struct bt_smp *smp)
  {
  	if (!atomic_test_and_clear_bit(smp->flags, SMP_FLAG_CFM_DELAYED)) {
  		return;
  	}
  
  	/* if confirm failed ie. due to invalid passkey, cancel pairing */
  	if (legacy_pairing_confirm(smp)) {
  		smp_error(smp, BT_SMP_ERR_PASSKEY_ENTRY_FAILED);
  		return;
  	}
  
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    smp->chan.chan.conn->role == BT_HCI_ROLE_MASTER) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_CONFIRM);
  		return;
  	}
  
  	if (IS_ENABLED(CONFIG_BT_PERIPHERAL)) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_RANDOM);
  	}
  }
  
  static void legacy_passkey_entry(struct bt_smp *smp, unsigned int passkey)
  {
  	passkey = sys_cpu_to_le32(passkey);
  	memcpy(smp->tk, &passkey, sizeof(passkey));
  
  	legacy_user_tk_entry(smp);
  }
  
  static uint8_t smp_encrypt_info(struct bt_smp *smp, struct net_buf *buf)
  {
  	BT_DBG("");
  
  	if (atomic_test_bit(smp->flags, SMP_FLAG_BOND)) {
  		struct bt_smp_encrypt_info *req = (void *)buf->data;
  		struct bt_conn *conn = smp->chan.chan.conn;
  		struct bt_keys *keys;
  
  		keys = bt_keys_get_type(BT_KEYS_LTK, conn->id, &conn->le.dst);
  		if (!keys) {
  			BT_ERR("Unable to get keys for %s",
  			       bt_addr_le_str(&conn->le.dst));
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		memcpy(keys->ltk.val, req->ltk, 16);
  	}
  
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_MASTER_IDENT);
  
  	return 0;
  }
  
  static uint8_t smp_master_ident(struct bt_smp *smp, struct net_buf *buf)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  	uint8_t err;
  
  	BT_DBG("");
  
  	if (atomic_test_bit(smp->flags, SMP_FLAG_BOND)) {
  		struct bt_smp_master_ident *req = (void *)buf->data;
  		struct bt_keys *keys;
  
  		keys = bt_keys_get_type(BT_KEYS_LTK, conn->id, &conn->le.dst);
  		if (!keys) {
  			BT_ERR("Unable to get keys for %s",
  			       bt_addr_le_str(&conn->le.dst));
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		memcpy(keys->ltk.ediv, req->ediv, sizeof(keys->ltk.ediv));
  		memcpy(keys->ltk.rand, req->rand, sizeof(req->rand));
  
  		smp->remote_dist &= ~BT_SMP_DIST_ENC_KEY;
  	}
  
  	if (smp->remote_dist & BT_SMP_DIST_ID_KEY) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_IDENT_INFO);
  	} else if (smp->remote_dist & BT_SMP_DIST_SIGN) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_SIGNING_INFO);
  	}
  
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    conn->role == BT_HCI_ROLE_MASTER && !smp->remote_dist) {
  		err = bt_smp_distribute_keys(smp);
  		if (err) {
  			return err;
  		}
  	}
  
  	/* if all keys were distributed, pairing is done */
  	if (!smp->local_dist && !smp->remote_dist) {
  		smp_pairing_complete(smp, 0);
  	}
  
  	return 0;
  }
  
  #if defined(CONFIG_BT_CENTRAL)
  static uint8_t legacy_pairing_rsp(struct bt_smp *smp)
  {
  	uint8_t ret;
  
  	BT_DBG("");
  
  	ret = legacy_request_tk(smp);
  	if (ret) {
  		return ret;
  	}
  
  	/* ask for consent if this is due to received SecReq */
  	if ((DISPLAY_FIXED(smp) || smp->method == JUST_WORKS) &&
  	    atomic_test_bit(smp->flags, SMP_FLAG_SEC_REQ) &&
  	    bt_auth && bt_auth->pairing_confirm) {
  		atomic_set_bit(smp->flags, SMP_FLAG_USER);
  		bt_auth->pairing_confirm(smp->chan.chan.conn);
  		return 0;
  	}
  
  	if (!atomic_test_bit(smp->flags, SMP_FLAG_USER)) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_CONFIRM);
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_KEYPRESS_NOTIFICATION);
  		return legacy_send_pairing_confirm(smp);
  	}
  
  	atomic_set_bit(smp->flags, SMP_FLAG_CFM_DELAYED);
  
  	return 0;
  }
  #endif /* CONFIG_BT_CENTRAL */
  #else
  static uint8_t smp_encrypt_info(struct bt_smp *smp, struct net_buf *buf)
  {
  	return BT_SMP_ERR_CMD_NOTSUPP;
  }
  
  static uint8_t smp_master_ident(struct bt_smp *smp, struct net_buf *buf)
  {
  	return BT_SMP_ERR_CMD_NOTSUPP;
  }
  #endif /* !CONFIG_BT_SMP_SC_PAIR_ONLY */
  
  static int smp_init(struct bt_smp *smp)
  {
  	/* Initialize SMP context without clearing L2CAP channel context */
  	(void)memset((uint8_t *)smp + sizeof(smp->chan), 0,
  		     sizeof(*smp) - (sizeof(smp->chan) + sizeof(smp->work)));
  
  	/* Generate local random number */
  	if (bt_rand(smp->prnd, 16)) {
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	BT_DBG("prnd %s", bt_hex(smp->prnd, 16));
  
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_FAIL);
  
  #if !defined(CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY)
  	sc_public_key = bt_pub_key_get();
  #endif
  
  	return 0;
  }
  
  void bt_set_bondable(bool enable)
  {
  	bondable = enable;
  }
  
  void bt_set_oob_data_flag(bool enable)
  {
  	oobd_present = enable;
  }
  
  static uint8_t get_auth(struct bt_conn *conn, uint8_t auth)
  {
  	if (sc_supported) {
  		auth &= BT_SMP_AUTH_MASK_SC;
  	} else {
  		auth &= BT_SMP_AUTH_MASK;
  	}
  
  	if ((get_io_capa() == BT_SMP_IO_NO_INPUT_OUTPUT) ||
  	    (!IS_ENABLED(CONFIG_BT_SMP_ENFORCE_MITM) &&
  	    (conn->required_sec_level < BT_SECURITY_L3))) {
  		auth &= ~(BT_SMP_AUTH_MITM);
  	} else {
  		auth |= BT_SMP_AUTH_MITM;
  	}
  
  	if (bondable) {
  		auth |= BT_SMP_AUTH_BONDING;
  	} else {
  		auth &= ~BT_SMP_AUTH_BONDING;
  	}
  
  	return auth;
  }
  
  static uint8_t remote_sec_level_reachable(struct bt_smp *smp)
  {
  	bt_security_t sec = smp->chan.chan.conn->required_sec_level;
  
  	if (IS_ENABLED(CONFIG_BT_SMP_SC_ONLY)) {
  		sec = BT_SECURITY_L4;
  	}
  	if (IS_ENABLED(CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY)) {
  		sec = BT_SECURITY_L3;
  	}
  
  	switch (sec) {
  	case BT_SECURITY_L1:
  	case BT_SECURITY_L2:
  		return 0;
  
  	case BT_SECURITY_L4:
  		if (get_encryption_key_size(smp) != BT_SMP_MAX_ENC_KEY_SIZE) {
  			return BT_SMP_ERR_ENC_KEY_SIZE;
  		}
  
  		if (!atomic_test_bit(smp->flags, SMP_FLAG_SC)) {
  			return BT_SMP_ERR_AUTH_REQUIREMENTS;
  		}
  		__fallthrough;
  	case BT_SECURITY_L3:
  		if (smp->method == JUST_WORKS) {
  			return BT_SMP_ERR_AUTH_REQUIREMENTS;
  		}
  
  		return 0;
  	default:
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  }
  
  static bool sec_level_reachable(struct bt_conn *conn)
  {
  	switch (conn->required_sec_level) {
  	case BT_SECURITY_L1:
  	case BT_SECURITY_L2:
  		return true;
  	case BT_SECURITY_L3:
  		return get_io_capa() != BT_SMP_IO_NO_INPUT_OUTPUT ||
  		       (bt_auth && bt_auth->oob_data_request);
  	case BT_SECURITY_L4:
  		return (get_io_capa() != BT_SMP_IO_NO_INPUT_OUTPUT ||
  			(bt_auth && bt_auth->oob_data_request)) && sc_supported;
  	default:
  		return false;
  	}
  }
  
  static struct bt_smp *smp_chan_get(struct bt_conn *conn)
  {
  	struct bt_l2cap_chan *chan;
  
  	chan = bt_l2cap_le_lookup_rx_cid(conn, BT_L2CAP_CID_SMP);
  	if (!chan) {
  		BT_ERR("Unable to find SMP channel");
  		return NULL;
  	}
  
  	return CONTAINER_OF(chan, struct bt_smp, chan);
  }
  
  bool bt_smp_request_ltk(struct bt_conn *conn, uint64_t rand, uint16_t ediv, uint8_t *ltk)
  {
  	struct bt_smp *smp;
  	uint8_t enc_size;
  
  	smp = smp_chan_get(conn);
  	if (!smp) {
  		return false;
  	}
  
  	/*
  	 * Both legacy STK and LE SC LTK have rand and ediv equal to zero.
  	 * If pairing is in progress use the TK for encryption.
  	 */
  	if (ediv == 0U && rand == 0U &&
  	    atomic_test_bit(smp->flags, SMP_FLAG_PAIRING) &&
  	    atomic_test_bit(smp->flags, SMP_FLAG_ENC_PENDING)) {
  		enc_size = get_encryption_key_size(smp);
  
  		/*
  		 * We keep both legacy STK and LE SC LTK in TK.
  		 * Also use only enc_size bytes of key for encryption.
  		 */
  		memcpy(ltk, smp->tk, enc_size);
  		if (enc_size < BT_SMP_MAX_ENC_KEY_SIZE) {
  			(void)memset(ltk + enc_size, 0,
  				     BT_SMP_MAX_ENC_KEY_SIZE - enc_size);
  		}
  
  		atomic_set_bit(smp->flags, SMP_FLAG_ENC_PENDING);
  		return true;
  	}
  
  	if (!conn->le.keys) {
  		conn->le.keys = bt_keys_find(BT_KEYS_LTK_P256, conn->id,
  					     &conn->le.dst);
  		if (!conn->le.keys) {
  			conn->le.keys = bt_keys_find(BT_KEYS_SLAVE_LTK,
  						     conn->id, &conn->le.dst);
  		}
  	}
  
  	if (ediv == 0U && rand == 0U &&
  	    conn->le.keys && (conn->le.keys->keys & BT_KEYS_LTK_P256)) {
  		enc_size = conn->le.keys->enc_size;
  
  		memcpy(ltk, conn->le.keys->ltk.val, enc_size);
  		if (enc_size < BT_SMP_MAX_ENC_KEY_SIZE) {
  			(void)memset(ltk + enc_size, 0,
  				     BT_SMP_MAX_ENC_KEY_SIZE - enc_size);
  		}
  
  		atomic_set_bit(smp->flags, SMP_FLAG_ENC_PENDING);
  		return true;
  	}
  
  #if !defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
  	if (conn->le.keys && (conn->le.keys->keys & BT_KEYS_SLAVE_LTK) &&
  	    !memcmp(conn->le.keys->slave_ltk.rand, &rand, 8) &&
  	    !memcmp(conn->le.keys->slave_ltk.ediv, &ediv, 2)) {
  		enc_size = conn->le.keys->enc_size;
  
  		memcpy(ltk, conn->le.keys->slave_ltk.val, enc_size);
  		if (enc_size < BT_SMP_MAX_ENC_KEY_SIZE) {
  			(void)memset(ltk + enc_size, 0,
  				     BT_SMP_MAX_ENC_KEY_SIZE - enc_size);
  		}
  
  		atomic_set_bit(smp->flags, SMP_FLAG_ENC_PENDING);
  		return true;
  	}
  #endif /* !CONFIG_BT_SMP_SC_PAIR_ONLY */
  
  	if (atomic_test_bit(smp->flags, SMP_FLAG_SEC_REQ)) {
  		/* Notify higher level that security failed if security was
  		 * initiated by slave.
  		 */
  		bt_conn_security_changed(conn, BT_HCI_ERR_PIN_OR_KEY_MISSING,
  					 BT_SECURITY_ERR_PIN_OR_KEY_MISSING);
  	}
  
  	smp_reset(smp);
  	return false;
  }
  
  #if defined(CONFIG_BT_PERIPHERAL)
  static int smp_send_security_req(struct bt_conn *conn)
  {
  	struct bt_smp *smp;
  	struct bt_smp_security_request *req;
  	struct net_buf *req_buf;
  
  	BT_DBG("");
  	smp = smp_chan_get(conn);
  	if (!smp) {
  		return -ENOTCONN;
  	}
  
  	/* SMP Timeout */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_TIMEOUT)) {
  		return -EIO;
  	}
  
  	/* pairing is in progress */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_PAIRING)) {
  		return -EBUSY;
  	}
  
  	if (atomic_test_bit(smp->flags, SMP_FLAG_ENC_PENDING)) {
  		return -EBUSY;
  	}
  
  	/* early verify if required sec level if reachable */
  	if (!(sec_level_reachable(conn) || smp_keys_check(conn))) {
  		return -EINVAL;
  	}
  
  	if (!conn->le.keys) {
  		conn->le.keys = bt_keys_get_addr(conn->id, &conn->le.dst);
  		if (!conn->le.keys) {
  			return -ENOMEM;
  		}
  	}
  
  	if (smp_init(smp) != 0) {
  		return -ENOBUFS;
  	}
  
  	req_buf = smp_create_pdu(smp, BT_SMP_CMD_SECURITY_REQUEST,
  				 sizeof(*req));
  	if (!req_buf) {
  		return -ENOBUFS;
  	}
  
  	req = net_buf_add(req_buf, sizeof(*req));
  	req->auth_req = get_auth(conn, BT_SMP_AUTH_DEFAULT);
  
  	/* SMP timer is not restarted for SecRequest so don't use smp_send */
  	bt_l2cap_send(conn, BT_L2CAP_CID_SMP, req_buf);
  
  	atomic_set_bit(smp->flags, SMP_FLAG_SEC_REQ);
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_REQ);
  
  	return 0;
  }
  
  static uint8_t smp_pairing_req(struct bt_smp *smp, struct net_buf *buf)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_smp_pairing *req = (void *)buf->data;
  	struct bt_smp_pairing *rsp;
  	uint8_t err;
  
  	BT_DBG("");
  
  	if ((req->max_key_size > BT_SMP_MAX_ENC_KEY_SIZE) ||
  	    (req->max_key_size < BT_SMP_MIN_ENC_KEY_SIZE)) {
  		return BT_SMP_ERR_ENC_KEY_SIZE;
  	}
  
  	if (!conn->le.keys) {
  		conn->le.keys = bt_keys_get_addr(conn->id, &conn->le.dst);
  		if (!conn->le.keys) {
  			BT_DBG("Unable to get keys for %s",
  			       bt_addr_le_str(&conn->le.dst));
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  	}
  
  	/* If we already sent a security request then the SMP context
  	 * is already initialized.
  	 */
  	if (!atomic_test_bit(smp->flags, SMP_FLAG_SEC_REQ)) {
  		int ret = smp_init(smp);
  
  		if (ret) {
  			return ret;
  		}
  	}
  
  	/* Store req for later use */
  	smp->preq[0] = BT_SMP_CMD_PAIRING_REQ;
  	memcpy(smp->preq + 1, req, sizeof(*req));
  
  	/* create rsp, it will be used later on */
  	smp->prsp[0] = BT_SMP_CMD_PAIRING_RSP;
  	rsp = (struct bt_smp_pairing *)&smp->prsp[1];
  
  	rsp->auth_req = get_auth(conn, req->auth_req);
  	rsp->io_capability = get_io_capa();
  	rsp->oob_flag = oobd_present ? BT_SMP_OOB_PRESENT :
  				       BT_SMP_OOB_NOT_PRESENT;
  	rsp->max_key_size = BT_SMP_MAX_ENC_KEY_SIZE;
  	rsp->init_key_dist = (req->init_key_dist & RECV_KEYS);
  	rsp->resp_key_dist = (req->resp_key_dist & SEND_KEYS);
  
  	if ((rsp->auth_req & BT_SMP_AUTH_SC) &&
  	    (req->auth_req & BT_SMP_AUTH_SC)) {
  		atomic_set_bit(smp->flags, SMP_FLAG_SC);
  
  		rsp->init_key_dist &= RECV_KEYS_SC;
  		rsp->resp_key_dist &= SEND_KEYS_SC;
  	}
  
  	if ((rsp->auth_req & BT_SMP_AUTH_CT2) &&
  	    (req->auth_req & BT_SMP_AUTH_CT2)) {
  		atomic_set_bit(smp->flags, SMP_FLAG_CT2);
  	}
  
  	smp->local_dist = rsp->resp_key_dist;
  	smp->remote_dist = rsp->init_key_dist;
  
  	if ((rsp->auth_req & BT_SMP_AUTH_BONDING) &&
  	    (req->auth_req & BT_SMP_AUTH_BONDING)) {
  		atomic_set_bit(smp->flags, SMP_FLAG_BOND);
  	} else if (IS_ENABLED(CONFIG_BT_BONDING_REQUIRED)) {
  		/* Reject pairing req if not both intend to bond */
  		BT_DBG("Bonding required");
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	atomic_set_bit(smp->flags, SMP_FLAG_PAIRING);
  
  	smp->method = get_pair_method(smp, req->io_capability);
  
  	if (!update_keys_check(smp, conn->le.keys)) {
  		return BT_SMP_ERR_AUTH_REQUIREMENTS;
  	}
  
  	err = remote_sec_level_reachable(smp);
  	if (err) {
  		return err;
  	}
  
  	if (!atomic_test_bit(smp->flags, SMP_FLAG_SC)) {
  #if defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
  		return BT_SMP_ERR_AUTH_REQUIREMENTS;
  #else
  		if (IS_ENABLED(CONFIG_BT_SMP_APP_PAIRING_ACCEPT)) {
  			err = smp_pairing_accept_query(conn, req);
  			if (err) {
  				return err;
  			}
  		}
  
  		return legacy_pairing_req(smp);
  #endif /* CONFIG_BT_SMP_SC_PAIR_ONLY */
  	}
  
  	if (IS_ENABLED(CONFIG_BT_SMP_APP_PAIRING_ACCEPT)) {
  		err = smp_pairing_accept_query(conn, req);
  		if (err) {
  			return err;
  		}
  	}
  
  	if ((DISPLAY_FIXED(smp) || smp->method == JUST_WORKS) &&
  	    !atomic_test_bit(smp->flags, SMP_FLAG_SEC_REQ) &&
  	    bt_auth && bt_auth->pairing_confirm) {
  		atomic_set_bit(smp->flags, SMP_FLAG_USER);
  		bt_auth->pairing_confirm(conn);
  		return 0;
  	}
  
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PUBLIC_KEY);
  	return send_pairing_rsp(smp);
  }
  #else
  static uint8_t smp_pairing_req(struct bt_smp *smp, struct net_buf *buf)
  {
  	return BT_SMP_ERR_CMD_NOTSUPP;
  }
  #endif /* CONFIG_BT_PERIPHERAL */
  
  static uint8_t sc_send_public_key(struct bt_smp *smp)
  {
  	struct bt_smp_public_key *req;
  	struct net_buf *req_buf;
  
  	req_buf = smp_create_pdu(smp, BT_SMP_CMD_PUBLIC_KEY, sizeof(*req));
  	if (!req_buf) {
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	req = net_buf_add(req_buf, sizeof(*req));
  
  	memcpy(req->x, sc_public_key, sizeof(req->x));
  	memcpy(req->y, &sc_public_key[32], sizeof(req->y));
  
  	smp_send(smp, req_buf, NULL, NULL);
  
  	if (IS_ENABLED(CONFIG_BT_USE_DEBUG_KEYS)) {
  		atomic_set_bit(smp->flags, SMP_FLAG_SC_DEBUG_KEY);
  	}
  
  	return 0;
  }
  
  #if defined(CONFIG_BT_CENTRAL)
  static int smp_send_pairing_req(struct bt_conn *conn)
  {
  	struct bt_smp *smp;
  	struct bt_smp_pairing *req;
  	struct net_buf *req_buf;
  
  	BT_DBG("");
  
  	smp = smp_chan_get(conn);
  	if (!smp) {
  		return -ENOTCONN;
  	}
  
  	/* SMP Timeout */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_TIMEOUT)) {
  		return -EIO;
  	}
  
  	/* A higher security level is requested during the key distribution
  	 * phase, once pairing is complete a new pairing procedure will start.
  	 */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_KEYS_DISTR)) {
  		return 0;
  	}
  
  	/* pairing is in progress */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_PAIRING)) {
  		return -EBUSY;
  	}
  
  	/* Encryption is in progress */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_ENC_PENDING)) {
  		return -EBUSY;
  	}
  
  	/* early verify if required sec level if reachable */
  	if (!sec_level_reachable(conn)) {
  		return -EINVAL;
  	}
  
  	if (!conn->le.keys) {
  		conn->le.keys = bt_keys_get_addr(conn->id, &conn->le.dst);
  		if (!conn->le.keys) {
  			return -ENOMEM;
  		}
  	}
  
  	if (smp_init(smp)) {
  		return -ENOBUFS;
  	}
  
  	req_buf = smp_create_pdu(smp, BT_SMP_CMD_PAIRING_REQ, sizeof(*req));
  	if (!req_buf) {
  		return -ENOBUFS;
  	}
  
  	req = net_buf_add(req_buf, sizeof(*req));
  
  	req->auth_req = get_auth(conn, BT_SMP_AUTH_DEFAULT);
  	req->io_capability = get_io_capa();
  	req->oob_flag = oobd_present ? BT_SMP_OOB_PRESENT :
  				       BT_SMP_OOB_NOT_PRESENT;
  	req->max_key_size = BT_SMP_MAX_ENC_KEY_SIZE;
  	req->init_key_dist = SEND_KEYS;
  	req->resp_key_dist = RECV_KEYS;
  
  	smp->local_dist = SEND_KEYS;
  	smp->remote_dist = RECV_KEYS;
  
  	/* Store req for later use */
  	smp->preq[0] = BT_SMP_CMD_PAIRING_REQ;
  	memcpy(smp->preq + 1, req, sizeof(*req));
  
  	smp_send(smp, req_buf, NULL, NULL);
  
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_RSP);
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_SECURITY_REQUEST);
  	atomic_set_bit(smp->flags, SMP_FLAG_PAIRING);
  
  	return 0;
  }
  
  static uint8_t smp_pairing_rsp(struct bt_smp *smp, struct net_buf *buf)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_smp_pairing *rsp = (void *)buf->data;
  	struct bt_smp_pairing *req = (struct bt_smp_pairing *)&smp->preq[1];
  	uint8_t err;
  
  	BT_DBG("");
  
  	if ((rsp->max_key_size > BT_SMP_MAX_ENC_KEY_SIZE) ||
  	    (rsp->max_key_size < BT_SMP_MIN_ENC_KEY_SIZE)) {
  		return BT_SMP_ERR_ENC_KEY_SIZE;
  	}
  
  	smp->local_dist &= rsp->init_key_dist;
  	smp->remote_dist &= rsp->resp_key_dist;
  
  	/* Store rsp for later use */
  	smp->prsp[0] = BT_SMP_CMD_PAIRING_RSP;
  	memcpy(smp->prsp + 1, rsp, sizeof(*rsp));
  
  	if ((rsp->auth_req & BT_SMP_AUTH_SC) &&
  	    (req->auth_req & BT_SMP_AUTH_SC)) {
  		atomic_set_bit(smp->flags, SMP_FLAG_SC);
  	}
  
  	if ((rsp->auth_req & BT_SMP_AUTH_CT2) &&
  	    (req->auth_req & BT_SMP_AUTH_CT2)) {
  		atomic_set_bit(smp->flags, SMP_FLAG_CT2);
  	}
  
  	if ((rsp->auth_req & BT_SMP_AUTH_BONDING) &&
  	    (req->auth_req & BT_SMP_AUTH_BONDING)) {
  		atomic_set_bit(smp->flags, SMP_FLAG_BOND);
  	} else if (IS_ENABLED(CONFIG_BT_BONDING_REQUIRED)) {
  		/* Reject pairing req if not both intend to bond */
  		BT_DBG("Bonding required");
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	smp->method = get_pair_method(smp, rsp->io_capability);
  
  	if (!update_keys_check(smp, conn->le.keys)) {
  		return BT_SMP_ERR_AUTH_REQUIREMENTS;
  	}
  
  	err = remote_sec_level_reachable(smp);
  	if (err) {
  		return err;
  	}
  
  	if (!atomic_test_bit(smp->flags, SMP_FLAG_SC)) {
  #if defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
  		return BT_SMP_ERR_AUTH_REQUIREMENTS;
  #else
  		if (IS_ENABLED(CONFIG_BT_SMP_APP_PAIRING_ACCEPT)) {
  			err = smp_pairing_accept_query(conn, rsp);
  			if (err) {
  				return err;
  			}
  		}
  
  		return legacy_pairing_rsp(smp);
  #endif /* CONFIG_BT_SMP_SC_PAIR_ONLY */
  	}
  
  	smp->local_dist &= SEND_KEYS_SC;
  	smp->remote_dist &= RECV_KEYS_SC;
  
  	if (IS_ENABLED(CONFIG_BT_SMP_APP_PAIRING_ACCEPT)) {
  		err = smp_pairing_accept_query(conn, rsp);
  		if (err) {
  			return err;
  		}
  	}
  
  	if ((DISPLAY_FIXED(smp) || smp->method == JUST_WORKS) &&
  	    atomic_test_bit(smp->flags, SMP_FLAG_SEC_REQ) &&
  	    bt_auth && bt_auth->pairing_confirm) {
  		atomic_set_bit(smp->flags, SMP_FLAG_USER);
  		bt_auth->pairing_confirm(conn);
  		return 0;
  	}
  
  	if (!sc_public_key) {
  		atomic_set_bit(smp->flags, SMP_FLAG_PKEY_SEND);
  		return 0;
  	}
  
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PUBLIC_KEY);
  	atomic_clear_bit(smp->allowed_cmds, BT_SMP_CMD_SECURITY_REQUEST);
  
  	return sc_send_public_key(smp);
  }
  #else
  static uint8_t smp_pairing_rsp(struct bt_smp *smp, struct net_buf *buf)
  {
  	return BT_SMP_ERR_CMD_NOTSUPP;
  }
  #endif /* CONFIG_BT_CENTRAL */
  
  static uint8_t smp_pairing_confirm(struct bt_smp *smp, struct net_buf *buf)
  {
  	struct bt_smp_pairing_confirm *req = (void *)buf->data;
  
  	BT_DBG("");
  
  	atomic_clear_bit(smp->flags, SMP_FLAG_DISPLAY);
  
  	memcpy(smp->pcnf, req->val, sizeof(smp->pcnf));
  
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    smp->chan.chan.conn->role == BT_HCI_ROLE_MASTER) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_RANDOM);
  		return smp_send_pairing_random(smp);
  	}
  
  	if (!IS_ENABLED(CONFIG_BT_PERIPHERAL)) {
  		return 0;
  	}
  
  #if !defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
  	if (!atomic_test_bit(smp->flags, SMP_FLAG_SC)) {
  		return legacy_pairing_confirm(smp);
  	}
  #endif /* !CONFIG_BT_SMP_SC_PAIR_ONLY */
  
  	switch (smp->method) {
  	case PASSKEY_DISPLAY:
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_RANDOM);
  		return smp_send_pairing_confirm(smp);
  	case PASSKEY_INPUT:
  		if (atomic_test_bit(smp->flags, SMP_FLAG_USER)) {
  			atomic_set_bit(smp->flags, SMP_FLAG_CFM_DELAYED);
  			return 0;
  		}
  
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_RANDOM);
  		return smp_send_pairing_confirm(smp);
  	case JUST_WORKS:
  	case PASSKEY_CONFIRM:
  	default:
  		BT_ERR("Unknown pairing method (%u)", smp->method);
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  }
  
  static uint8_t sc_smp_send_dhkey_check(struct bt_smp *smp, const uint8_t *e)
  {
  	struct bt_smp_dhkey_check *req;
  	struct net_buf *buf;
  
  	BT_DBG("");
  
  	buf = smp_create_pdu(smp, BT_SMP_DHKEY_CHECK, sizeof(*req));
  	if (!buf) {
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	req = net_buf_add(buf, sizeof(*req));
  	memcpy(req->e, e, sizeof(req->e));
  
  	smp_send(smp, buf, NULL, NULL);
  
  	return 0;
  }
  
  #if defined(CONFIG_BT_CENTRAL)
  static uint8_t compute_and_send_master_dhcheck(struct bt_smp *smp)
  {
  	uint8_t e[16], r[16];
  
  	(void)memset(r, 0, sizeof(r));
  
  	switch (smp->method) {
  	case JUST_WORKS:
  	case PASSKEY_CONFIRM:
  		break;
  	case PASSKEY_DISPLAY:
  	case PASSKEY_INPUT:
  		memcpy(r, &smp->passkey, sizeof(smp->passkey));
  		break;
  	case LE_SC_OOB:
  		if (smp->oobd_remote) {
  			memcpy(r, smp->oobd_remote->r, sizeof(r));
  		}
  		break;
  	default:
  		BT_ERR("Unknown pairing method (%u)", smp->method);
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	/* calculate LTK and mackey */
  	if (smp_f5(smp->dhkey, smp->prnd, smp->rrnd,
  		   &smp->chan.chan.conn->le.init_addr,
  		   &smp->chan.chan.conn->le.resp_addr, smp->mackey,
  		   smp->tk)) {
  		BT_ERR("Calculate LTK failed");
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  	/* calculate local DHKey check */
  	if (smp_f6(smp->mackey, smp->prnd, smp->rrnd, r, &smp->preq[1],
  		   &smp->chan.chan.conn->le.init_addr,
  		   &smp->chan.chan.conn->le.resp_addr, e)) {
  		BT_ERR("Calculate local DHKey check failed");
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_DHKEY_CHECK);
  	return sc_smp_send_dhkey_check(smp, e);
  }
  #endif /* CONFIG_BT_CENTRAL */
  
  #if defined(CONFIG_BT_PERIPHERAL)
  static uint8_t compute_and_check_and_send_slave_dhcheck(struct bt_smp *smp)
  {
  	uint8_t re[16], e[16], r[16];
  	uint8_t err;
  
  	(void)memset(r, 0, sizeof(r));
  
  	switch (smp->method) {
  	case JUST_WORKS:
  	case PASSKEY_CONFIRM:
  		break;
  	case PASSKEY_DISPLAY:
  	case PASSKEY_INPUT:
  		memcpy(r, &smp->passkey, sizeof(smp->passkey));
  		break;
  	case LE_SC_OOB:
  		if (smp->oobd_remote) {
  			memcpy(r, smp->oobd_remote->r, sizeof(r));
  		}
  		break;
  	default:
  		BT_ERR("Unknown pairing method (%u)", smp->method);
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	/* calculate LTK and mackey */
  	if (smp_f5(smp->dhkey, smp->rrnd, smp->prnd,
  		   &smp->chan.chan.conn->le.init_addr,
  		   &smp->chan.chan.conn->le.resp_addr, smp->mackey,
  		   smp->tk)) {
  		BT_ERR("Calculate LTK failed");
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	/* calculate local DHKey check */
  	if (smp_f6(smp->mackey, smp->prnd, smp->rrnd, r, &smp->prsp[1],
  		   &smp->chan.chan.conn->le.resp_addr,
  		   &smp->chan.chan.conn->le.init_addr, e)) {
  		BT_ERR("Calculate local DHKey check failed");
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	if (smp->method == LE_SC_OOB) {
  		if (smp->oobd_local) {
  			memcpy(r, smp->oobd_local->r, sizeof(r));
  		} else {
  			memset(r, 0, sizeof(r));
  		}
  	}
  
  	/* calculate remote DHKey check */
  	if (smp_f6(smp->mackey, smp->rrnd, smp->prnd, r, &smp->preq[1],
  		   &smp->chan.chan.conn->le.init_addr,
  		   &smp->chan.chan.conn->le.resp_addr, re)) {
  		BT_ERR("Calculate remote DHKey check failed");
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	/* compare received E with calculated remote */
  	if (memcmp(smp->e, re, 16)) {
  		return BT_SMP_ERR_DHKEY_CHECK_FAILED;
  	}
  
  	/* send local e */
  	err = sc_smp_send_dhkey_check(smp, e);
  	if (err) {
  		return err;
  	}
  
  	atomic_set_bit(smp->flags, SMP_FLAG_ENC_PENDING);
  	return 0;
  }
  #endif /* CONFIG_BT_PERIPHERAL */
  
  static void bt_smp_dhkey_ready(const uint8_t *dhkey);
  static uint8_t smp_dhkey_generate(struct bt_smp *smp)
  {
  	int err;
  
  	atomic_set_bit(smp->flags, SMP_FLAG_DHKEY_GEN);
  	err = bt_dh_key_gen(smp->pkey, bt_smp_dhkey_ready);
  	if (err) {
  		atomic_clear_bit(smp->flags, SMP_FLAG_DHKEY_GEN);
  
  		BT_ERR("Failed to generate DHKey");
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	return 0;
  }
  
  static uint8_t smp_dhkey_ready(struct bt_smp *smp, const uint8_t *dhkey)
  {
  	if (!dhkey) {
  		return BT_SMP_ERR_DHKEY_CHECK_FAILED;
  	}
  
  	atomic_clear_bit(smp->flags, SMP_FLAG_DHKEY_PENDING);
  	memcpy(smp->dhkey, dhkey, 32);
  
  	/* wait for user passkey confirmation */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_USER)) {
  		atomic_set_bit(smp->flags, SMP_FLAG_DHKEY_SEND);
  		return 0;
  	}
  
  	/* wait for remote DHKey Check */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_DHCHECK_WAIT)) {
  		atomic_set_bit(smp->flags, SMP_FLAG_DHKEY_SEND);
  		return 0;
  	}
  
  	if (atomic_test_bit(smp->flags, SMP_FLAG_DHKEY_SEND)) {
  #if defined(CONFIG_BT_CENTRAL)
  		if (smp->chan.chan.conn->role == BT_HCI_ROLE_MASTER) {
  			return compute_and_send_master_dhcheck(smp);
  		}
  
  #endif /* CONFIG_BT_CENTRAL */
  
  #if defined(CONFIG_BT_PERIPHERAL)
  		return  compute_and_check_and_send_slave_dhcheck(smp);
  #endif /* CONFIG_BT_PERIPHERAL */
  	}
  
  	return 0;
  }
  
  static struct bt_smp *smp_find(int flag)
  {
  	for (int i = 0; i < ARRAY_SIZE(bt_smp_pool); i++) {
  		if (atomic_test_bit(bt_smp_pool[i].flags, flag)) {
  			return &bt_smp_pool[i];
  		}
  	}
  
  	return NULL;
  }
  
  static void bt_smp_dhkey_ready(const uint8_t *dhkey)
  {
  	BT_DBG("%p", dhkey);
  	int err;
  
  	struct bt_smp *smp = smp_find(SMP_FLAG_DHKEY_GEN);
  	if (smp) {
  		atomic_clear_bit(smp->flags, SMP_FLAG_DHKEY_GEN);
  		err = smp_dhkey_ready(smp, dhkey);
  		if (err) {
  			smp_error(smp, err);
  		}
  	}
  
  	err = 0;
  	do {
  		smp = smp_find(SMP_FLAG_DHKEY_PENDING);
  		if (smp) {
  			err = smp_dhkey_generate(smp);
  			if (err) {
  				smp_error(smp, err);
  			}
  		}
  	} while (smp && err);
  }
  
  static uint8_t sc_smp_check_confirm(struct bt_smp *smp)
  {
  	uint8_t cfm[16];
  	uint8_t r;
  
  	switch (smp->method) {
  	case LE_SC_OOB:
  		return 0;
  	case PASSKEY_CONFIRM:
  	case JUST_WORKS:
  		r = 0U;
  		break;
  	case PASSKEY_DISPLAY:
  	case PASSKEY_INPUT:
  		/*
  		 * In the Passkey Entry protocol, the most significant
  		 * bit of Z is set equal to one and the least
  		 * significant bit is made up from one bit of the
  		 * passkey e.g. if the passkey bit is 1, then Z = 0x81
  		 * and if the passkey bit is 0, then Z = 0x80.
  		 */
  		r = (smp->passkey >> smp->passkey_round) & 0x01;
  		r |= 0x80;
  		break;
  	default:
  		BT_ERR("Unknown pairing method (%u)", smp->method);
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	if (smp_f4(smp->pkey, sc_public_key, smp->rrnd, r, cfm)) {
  		BT_ERR("Calculate confirm failed");
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	BT_DBG("pcnf %s", bt_hex(smp->pcnf, 16));
  	BT_DBG("cfm %s", bt_hex(cfm, 16));
  
  	if (memcmp(smp->pcnf, cfm, 16)) {
  		return BT_SMP_ERR_CONFIRM_FAILED;
  	}
  
  	return 0;
  }
  
  static bool le_sc_oob_data_req_check(struct bt_smp *smp)
  {
  	struct bt_smp_pairing *req = (struct bt_smp_pairing *)&smp->preq[1];
  
  	return ((req->oob_flag & BT_SMP_OOB_DATA_MASK) == BT_SMP_OOB_PRESENT);
  }
  
  static bool le_sc_oob_data_rsp_check(struct bt_smp *smp)
  {
  	struct bt_smp_pairing *rsp = (struct bt_smp_pairing *)&smp->prsp[1];
  
  	return ((rsp->oob_flag & BT_SMP_OOB_DATA_MASK) == BT_SMP_OOB_PRESENT);
  }
  
  static void le_sc_oob_config_set(struct bt_smp *smp,
  				 struct bt_conn_oob_info *info)
  {
  	bool req_oob_present = le_sc_oob_data_req_check(smp);
  	bool rsp_oob_present = le_sc_oob_data_rsp_check(smp);
  	int oob_config = BT_CONN_OOB_NO_DATA;
  
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    smp->chan.chan.conn->role == BT_HCI_ROLE_MASTER) {
  		oob_config = req_oob_present ? BT_CONN_OOB_REMOTE_ONLY :
  					       BT_CONN_OOB_NO_DATA;
  
  		if (rsp_oob_present) {
  			oob_config = (oob_config == BT_CONN_OOB_REMOTE_ONLY) ?
  				     BT_CONN_OOB_BOTH_PEERS :
  				     BT_CONN_OOB_LOCAL_ONLY;
  		}
  	} else if (IS_ENABLED(CONFIG_BT_PERIPHERAL)) {
  		oob_config = req_oob_present ? BT_CONN_OOB_LOCAL_ONLY :
  					       BT_CONN_OOB_NO_DATA;
  
  		if (rsp_oob_present) {
  			oob_config = (oob_config == BT_CONN_OOB_LOCAL_ONLY) ?
  				     BT_CONN_OOB_BOTH_PEERS :
  				     BT_CONN_OOB_REMOTE_ONLY;
  		}
  	}
  
  	info->lesc.oob_config = oob_config;
  }
  
  static uint8_t smp_pairing_random(struct bt_smp *smp, struct net_buf *buf)
  {
  	struct bt_smp_pairing_random *req = (void *)buf->data;
  	uint32_t passkey;
  	uint8_t err;
  
  	BT_DBG("");
  
  	memcpy(smp->rrnd, req->val, sizeof(smp->rrnd));
  
  #if !defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
  	if (!atomic_test_bit(smp->flags, SMP_FLAG_SC)) {
  		return legacy_pairing_random(smp);
  	}
  #endif /* !CONFIG_BT_SMP_SC_PAIR_ONLY */
  
  #if defined(CONFIG_BT_CENTRAL)
  	if (smp->chan.chan.conn->role == BT_HCI_ROLE_MASTER) {
  		err = sc_smp_check_confirm(smp);
  		if (err) {
  			return err;
  		}
  
  		switch (smp->method) {
  		case PASSKEY_CONFIRM:
  			/* compare passkey before calculating LTK */
  			if (smp_g2(sc_public_key, smp->pkey, smp->prnd,
  				   smp->rrnd, &passkey)) {
  				return BT_SMP_ERR_UNSPECIFIED;
  			}
  
  			atomic_set_bit(smp->flags, SMP_FLAG_USER);
  			atomic_set_bit(smp->flags, SMP_FLAG_DHKEY_SEND);
  			bt_auth->passkey_confirm(smp->chan.chan.conn, passkey);
  			return 0;
  		case JUST_WORKS:
  			break;
  		case LE_SC_OOB:
  			break;
  		case PASSKEY_DISPLAY:
  		case PASSKEY_INPUT:
  			smp->passkey_round++;
  			if (smp->passkey_round == 20U) {
  				break;
  			}
  
  			if (bt_rand(smp->prnd, 16)) {
  				return BT_SMP_ERR_UNSPECIFIED;
  			}
  
  			atomic_set_bit(smp->allowed_cmds,
  				       BT_SMP_CMD_PAIRING_CONFIRM);
  			return smp_send_pairing_confirm(smp);
  		default:
  			BT_ERR("Unknown pairing method (%u)", smp->method);
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		/* wait for DHKey being generated */
  		if (atomic_test_bit(smp->flags, SMP_FLAG_DHKEY_PENDING)) {
  			atomic_set_bit(smp->flags, SMP_FLAG_DHKEY_SEND);
  			return 0;
  		}
  
  		return compute_and_send_master_dhcheck(smp);
  	}
  #endif /* CONFIG_BT_CENTRAL */
  
  #if defined(CONFIG_BT_PERIPHERAL)
  	switch (smp->method) {
  	case PASSKEY_CONFIRM:
  		if (smp_g2(smp->pkey, sc_public_key, smp->rrnd, smp->prnd,
  			   &passkey)) {
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		atomic_set_bit(smp->flags, SMP_FLAG_USER);
  		bt_auth->passkey_confirm(smp->chan.chan.conn, passkey);
  		break;
  	case JUST_WORKS:
  		break;
  	case PASSKEY_DISPLAY:
  	case PASSKEY_INPUT:
  		err = sc_smp_check_confirm(smp);
  		if (err) {
  			return err;
  		}
  
  		atomic_set_bit(smp->allowed_cmds,
  			       BT_SMP_CMD_PAIRING_CONFIRM);
  		err = smp_send_pairing_random(smp);
  		if (err) {
  			return err;
  		}
  
  		smp->passkey_round++;
  		if (smp->passkey_round == 20U) {
  			atomic_set_bit(smp->allowed_cmds, BT_SMP_DHKEY_CHECK);
  			atomic_set_bit(smp->flags, SMP_FLAG_DHCHECK_WAIT);
  			return 0;
  		}
  
  		if (bt_rand(smp->prnd, 16)) {
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		return 0;
  	case LE_SC_OOB:
  		/* Step 6: Select random N */
  		if (bt_rand(smp->prnd, 16)) {
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		if (bt_auth && bt_auth->oob_data_request) {
  			struct bt_conn_oob_info info = {
  				.type = BT_CONN_OOB_LE_SC,
  				.lesc.oob_config = BT_CONN_OOB_NO_DATA,
  			};
  
  			le_sc_oob_config_set(smp, &info);
  
  			smp->oobd_local = NULL;
  			smp->oobd_remote = NULL;
  
  			atomic_set_bit(smp->flags, SMP_FLAG_OOB_PENDING);
  			bt_auth->oob_data_request(smp->chan.chan.conn, &info);
  
  			return 0;
  		} else {
  			return BT_SMP_ERR_OOB_NOT_AVAIL;
  		}
  	default:
  		BT_ERR("Unknown pairing method (%u)", smp->method);
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_DHKEY_CHECK);
  	atomic_set_bit(smp->flags, SMP_FLAG_DHCHECK_WAIT);
  	return smp_send_pairing_random(smp);
  #else
  	return BT_SMP_ERR_PAIRING_NOTSUPP;
  #endif /* CONFIG_BT_PERIPHERAL */
  }
  
  static uint8_t smp_pairing_failed(struct bt_smp *smp, struct net_buf *buf)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_smp_pairing_fail *req = (void *)buf->data;
  
  	BT_ERR("reason 0x%x", req->reason);
  
  	if (atomic_test_and_clear_bit(smp->flags, SMP_FLAG_USER) ||
  	    atomic_test_and_clear_bit(smp->flags, SMP_FLAG_DISPLAY)) {
  		if (bt_auth && bt_auth->cancel) {
  			bt_auth->cancel(conn);
  		}
  	}
  
  	smp_pairing_complete(smp, req->reason);
  
  	/* return no error to avoid sending Pairing Failed in response */
  	return 0;
  }
  
  static uint8_t smp_ident_info(struct bt_smp *smp, struct net_buf *buf)
  {
  	BT_DBG("");
  
  	if (atomic_test_bit(smp->flags, SMP_FLAG_BOND)) {
  		struct bt_smp_ident_info *req = (void *)buf->data;
  		struct bt_conn *conn = smp->chan.chan.conn;
  		struct bt_keys *keys;
  
  		keys = bt_keys_get_type(BT_KEYS_IRK, conn->id, &conn->le.dst);
  		if (!keys) {
  			BT_ERR("Unable to get keys for %s",
  			       bt_addr_le_str(&conn->le.dst));
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		memcpy(keys->irk.val, req->irk, 16);
  	}
  
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_IDENT_ADDR_INFO);
  
  	return 0;
  }
  
  static uint8_t smp_ident_addr_info(struct bt_smp *smp, struct net_buf *buf)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_smp_ident_addr_info *req = (void *)buf->data;
  	uint8_t err;
  
  	BT_DBG("identity %s", bt_addr_le_str(&req->addr));
  
  	if (!bt_addr_le_is_identity(&req->addr)) {
  		BT_ERR("Invalid identity %s", bt_addr_le_str(&req->addr));
  		BT_ERR(" for %s", bt_addr_le_str(&conn->le.dst));
  		return BT_SMP_ERR_INVALID_PARAMS;
  	}
  
  	if (bt_addr_le_cmp(&conn->le.dst, &req->addr) != 0) {
  		struct bt_keys *keys = bt_keys_find_addr(conn->id, &req->addr);
  
  		if (keys) {
  			if (!update_keys_check(smp, keys)) {
  				return BT_SMP_ERR_UNSPECIFIED;
  			}
  
  			bt_keys_clear(keys);
  		}
  	}
  
  	if (atomic_test_bit(smp->flags, SMP_FLAG_BOND)) {
  		const bt_addr_le_t *dst;
  		struct bt_keys *keys;
  
  		keys = bt_keys_get_type(BT_KEYS_IRK, conn->id, &conn->le.dst);
  		if (!keys) {
  			BT_ERR("Unable to get keys for %s",
  			       bt_addr_le_str(&conn->le.dst));
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		/*
  		 * We can't use conn->dst here as this might already contain
  		 * identity address known from previous pairing. Since all keys
  		 * are cleared on re-pairing we wouldn't store IRK distributed
  		 * in new pairing.
  		 */
  		if (conn->role == BT_HCI_ROLE_MASTER) {
  			dst = &conn->le.resp_addr;
  		} else {
  			dst = &conn->le.init_addr;
  		}
  
  		if (bt_addr_le_is_rpa(dst)) {
  			/* always update last use RPA */
  			bt_addr_copy(&keys->irk.rpa, &dst->a);
  
  			/*
  			 * Update connection address and notify about identity
  			 * resolved only if connection wasn't already reported
  			 * with identity address. This may happen if IRK was
  			 * present before ie. due to re-pairing.
  			 */
  			if (!bt_addr_le_is_identity(&conn->le.dst)) {
  				bt_addr_le_copy(&keys->addr, &req->addr);
  				bt_addr_le_copy(&conn->le.dst, &req->addr);
  
  				bt_conn_identity_resolved(conn);
  			}
  		}
  
  		bt_id_add(keys);
  	}
  
  	smp->remote_dist &= ~BT_SMP_DIST_ID_KEY;
  
  	if (smp->remote_dist & BT_SMP_DIST_SIGN) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_SIGNING_INFO);
  	}
  
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    conn->role == BT_HCI_ROLE_MASTER && !smp->remote_dist) {
  		err = bt_smp_distribute_keys(smp);
  		if (err) {
  			return err;
  		}
  	}
  
  	/* if all keys were distributed, pairing is done */
  	if (!smp->local_dist && !smp->remote_dist) {
  		smp_pairing_complete(smp, 0);
  	}
  
  	return 0;
  }
  
  #if defined(CONFIG_BT_SIGNING)
  static uint8_t smp_signing_info(struct bt_smp *smp, struct net_buf *buf)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  	uint8_t err;
  
  	BT_DBG("");
  
  	if (atomic_test_bit(smp->flags, SMP_FLAG_BOND)) {
  		struct bt_smp_signing_info *req = (void *)buf->data;
  		struct bt_keys *keys;
  
  		keys = bt_keys_get_type(BT_KEYS_REMOTE_CSRK, conn->id,
  					&conn->le.dst);
  		if (!keys) {
  			BT_ERR("Unable to get keys for %s",
  			       bt_addr_le_str(&conn->le.dst));
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		memcpy(keys->remote_csrk.val, req->csrk,
  		       sizeof(keys->remote_csrk.val));
  	}
  
  	smp->remote_dist &= ~BT_SMP_DIST_SIGN;
  
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    conn->role == BT_HCI_ROLE_MASTER && !smp->remote_dist) {
  		err = bt_smp_distribute_keys(smp);
  		if (err) {
  			return err;
  		}
  	}
  
  	/* if all keys were distributed, pairing is done */
  	if (!smp->local_dist && !smp->remote_dist) {
  		smp_pairing_complete(smp, 0);
  	}
  
  	return 0;
  }
  #else
  static uint8_t smp_signing_info(struct bt_smp *smp, struct net_buf *buf)
  {
  	return BT_SMP_ERR_CMD_NOTSUPP;
  }
  #endif /* CONFIG_BT_SIGNING */
  
  #if defined(CONFIG_BT_CENTRAL)
  static uint8_t smp_security_request(struct bt_smp *smp, struct net_buf *buf)
  {
  	struct bt_conn *conn = smp->chan.chan.conn;
  	struct bt_smp_security_request *req = (void *)buf->data;
  	uint8_t auth;
  
  	BT_DBG("");
  
  	/* A higher security level is requested during the key distribution
  	 * phase, once pairing is complete a new pairing procedure will start.
  	 */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_KEYS_DISTR)) {
  		return 0;
  	}
  
  	if (atomic_test_bit(smp->flags, SMP_FLAG_PAIRING)) {
  		/* We have already started pairing process */
  		return 0;
  	}
  
  	if (atomic_test_bit(smp->flags, SMP_FLAG_ENC_PENDING)) {
  		/* We have already started encryption procedure */
  		return 0;
  	}
  
  	if (sc_supported) {
  		auth = req->auth_req & BT_SMP_AUTH_MASK_SC;
  	} else {
  		auth = req->auth_req & BT_SMP_AUTH_MASK;
  	}
  
  	if (IS_ENABLED(CONFIG_BT_SMP_SC_PAIR_ONLY) &&
  	    !(auth & BT_SMP_AUTH_SC)) {
  		return BT_SMP_ERR_AUTH_REQUIREMENTS;
  	}
  
  	if (IS_ENABLED(CONFIG_BT_BONDING_REQUIRED) &&
  	    !(bondable && (auth & BT_SMP_AUTH_BONDING))) {
  		/* Reject security req if not both intend to bond */
  		BT_DBG("Bonding required");
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	if (conn->le.keys) {
  		/* Make sure we have an LTK to encrypt with */
  		if (!(conn->le.keys->keys & (BT_KEYS_LTK_P256 | BT_KEYS_LTK))) {
  			goto pair;
  		}
  	} else {
  		conn->le.keys = bt_keys_find(BT_KEYS_LTK_P256, conn->id,
  					     &conn->le.dst);
  		if (!conn->le.keys) {
  			conn->le.keys = bt_keys_find(BT_KEYS_LTK, conn->id,
  						     &conn->le.dst);
  		}
  	}
  
  	if (!conn->le.keys) {
  		goto pair;
  	}
  
  	/* if MITM required key must be authenticated */
  	if ((auth & BT_SMP_AUTH_MITM) &&
  	    !(conn->le.keys->flags & BT_KEYS_AUTHENTICATED)) {
  		if (get_io_capa() != BT_SMP_IO_NO_INPUT_OUTPUT) {
  			BT_INFO("New auth requirements: 0x%x, repairing",
  				auth);
  			goto pair;
  		}
  
  		BT_WARN("Unsupported auth requirements: 0x%x, repairing",
  			auth);
  		goto pair;
  	}
  
  	/* if LE SC required and no p256 key present repair */
  	if ((auth & BT_SMP_AUTH_SC) &&
  	    !(conn->le.keys->keys & BT_KEYS_LTK_P256)) {
  		BT_INFO("New auth requirements: 0x%x, repairing", auth);
  		goto pair;
  	}
  
  	if (bt_conn_le_start_encryption(conn, conn->le.keys->ltk.rand,
  					conn->le.keys->ltk.ediv,
  					conn->le.keys->ltk.val,
  					conn->le.keys->enc_size) < 0) {
  		BT_ERR("Failed to start encryption");
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	atomic_set_bit(smp->flags, SMP_FLAG_ENC_PENDING);
  
  	return 0;
  pair:
  	if (smp_send_pairing_req(conn) < 0) {
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	atomic_set_bit(smp->flags, SMP_FLAG_SEC_REQ);
  
  	return 0;
  }
  #else
  static uint8_t smp_security_request(struct bt_smp *smp, struct net_buf *buf)
  {
  	return BT_SMP_ERR_CMD_NOTSUPP;
  }
  #endif /* CONFIG_BT_CENTRAL */
  
  static uint8_t generate_dhkey(struct bt_smp *smp)
  {
  	if (IS_ENABLED(CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY)) {
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	atomic_set_bit(smp->flags, SMP_FLAG_DHKEY_PENDING);
  	if (!smp_find(SMP_FLAG_DHKEY_GEN)) {
  		return smp_dhkey_generate(smp);
  	}
  
  	return 0;
  }
  
  static uint8_t display_passkey(struct bt_smp *smp)
  {
  	if (IS_ENABLED(CONFIG_BT_FIXED_PASSKEY) &&
  	    fixed_passkey != BT_PASSKEY_INVALID) {
  		smp->passkey = fixed_passkey;
  	} else {
  		if (bt_rand(&smp->passkey, sizeof(smp->passkey))) {
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		smp->passkey %= 1000000;
  	}
  
  	smp->passkey_round = 0U;
  
  	if (bt_auth && bt_auth->passkey_display) {
  		atomic_set_bit(smp->flags, SMP_FLAG_DISPLAY);
  		bt_auth->passkey_display(smp->chan.chan.conn, smp->passkey);
  	}
  
  	smp->passkey = sys_cpu_to_le32(smp->passkey);
  
  	return 0;
  }
  
  #if defined(CONFIG_BT_PERIPHERAL)
  static uint8_t smp_public_key_slave(struct bt_smp *smp)
  {
  	uint8_t err;
  
  	if (!atomic_test_bit(smp->flags, SMP_FLAG_SC_DEBUG_KEY) &&
  	    memcmp(smp->pkey, sc_public_key, 64) == 0) {
  		BT_WARN("Remote is using identical public key");
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	err = sc_send_public_key(smp);
  	if (err) {
  		return err;
  	}
  
  	switch (smp->method) {
  	case PASSKEY_CONFIRM:
  	case JUST_WORKS:
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_RANDOM);
  
  		err = smp_send_pairing_confirm(smp);
  		if (err) {
  			return err;
  		}
  		break;
  	case PASSKEY_DISPLAY:
  		err = display_passkey(smp);
  		if (err) {
  			return err;
  		}
  
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_CONFIRM);
  		break;
  	case PASSKEY_INPUT:
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_CONFIRM);
  		atomic_set_bit(smp->flags, SMP_FLAG_USER);
  		bt_auth->passkey_entry(smp->chan.chan.conn);
  		break;
  	case LE_SC_OOB:
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_RANDOM);
  		break;
  	default:
  		BT_ERR("Unknown pairing method (%u)", smp->method);
  		return BT_SMP_ERR_UNSPECIFIED;
  	}
  
  	return generate_dhkey(smp);
  }
  #endif /* CONFIG_BT_PERIPHERAL */
  
  static uint8_t smp_public_key(struct bt_smp *smp, struct net_buf *buf)
  {
  	struct bt_smp_public_key *req = (void *)buf->data;
  	uint8_t err;
  
  	BT_DBG("");
  
  	memcpy(smp->pkey, req->x, 32);
  	memcpy(&smp->pkey[32], req->y, 32);
  
  	/* mark key as debug if remote is using it */
  	if (bt_pub_key_is_debug(smp->pkey)) {
  		BT_INFO("Remote is using Debug Public key");
  		atomic_set_bit(smp->flags, SMP_FLAG_SC_DEBUG_KEY);
  
  		/* Don't allow a bond established without debug key to be
  		 * updated using LTK generated from debug key.
  		 */
  		if (!update_debug_keys_check(smp)) {
  			return BT_SMP_ERR_AUTH_REQUIREMENTS;
  		}
  	}
  
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    smp->chan.chan.conn->role == BT_HCI_ROLE_MASTER) {
  		if (!atomic_test_bit(smp->flags, SMP_FLAG_SC_DEBUG_KEY) &&
  		    memcmp(smp->pkey, sc_public_key, 64) == 0) {
  			BT_WARN("Remote is using identical public key");
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		switch (smp->method) {
  		case PASSKEY_CONFIRM:
  		case JUST_WORKS:
  			atomic_set_bit(smp->allowed_cmds,
  				       BT_SMP_CMD_PAIRING_CONFIRM);
  			break;
  		case PASSKEY_DISPLAY:
  			err = display_passkey(smp);
  			if (err) {
  				return err;
  			}
  
  			atomic_set_bit(smp->allowed_cmds,
  				       BT_SMP_CMD_PAIRING_CONFIRM);
  
  			atomic_set_bit(smp->allowed_cmds,
  				       BT_SMP_KEYPRESS_NOTIFICATION);
  
  			err = smp_send_pairing_confirm(smp);
  			if (err) {
  				return err;
  			}
  			break;
  		case PASSKEY_INPUT:
  			atomic_set_bit(smp->flags, SMP_FLAG_USER);
  			bt_auth->passkey_entry(smp->chan.chan.conn);
  
  			atomic_set_bit(smp->allowed_cmds,
  				       BT_SMP_KEYPRESS_NOTIFICATION);
  
  			break;
  		case LE_SC_OOB:
  			/* Step 6: Select random N */
  			if (bt_rand(smp->prnd, 16)) {
  				return BT_SMP_ERR_UNSPECIFIED;
  			}
  
  			if (bt_auth && bt_auth->oob_data_request) {
  				struct bt_conn_oob_info info = {
  					.type = BT_CONN_OOB_LE_SC,
  					.lesc.oob_config = BT_CONN_OOB_NO_DATA,
  				};
  
  				le_sc_oob_config_set(smp, &info);
  
  				smp->oobd_local = NULL;
  				smp->oobd_remote = NULL;
  
  				atomic_set_bit(smp->flags,
  					       SMP_FLAG_OOB_PENDING);
  				bt_auth->oob_data_request(smp->chan.chan.conn,
  							  &info);
  			} else {
  				return BT_SMP_ERR_OOB_NOT_AVAIL;
  			}
  			break;
  		default:
  			BT_ERR("Unknown pairing method (%u)", smp->method);
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		return generate_dhkey(smp);
  	}
  
  #if defined(CONFIG_BT_PERIPHERAL)
  	if (!sc_public_key) {
  		atomic_set_bit(smp->flags, SMP_FLAG_PKEY_SEND);
  		return 0;
  	}
  
  	err = smp_public_key_slave(smp);
  	if (err) {
  		return err;
  	}
  #endif /* CONFIG_BT_PERIPHERAL */
  
  	return 0;
  }
  
  static uint8_t smp_dhkey_check(struct bt_smp *smp, struct net_buf *buf)
  {
  	struct bt_smp_dhkey_check *req = (void *)buf->data;
  
  	BT_DBG("");
  
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    smp->chan.chan.conn->role == BT_HCI_ROLE_MASTER) {
  		uint8_t e[16], r[16], enc_size;
  		uint8_t ediv[2], rand[8];
  
  		(void)memset(r, 0, sizeof(r));
  
  		switch (smp->method) {
  		case JUST_WORKS:
  		case PASSKEY_CONFIRM:
  			break;
  		case PASSKEY_DISPLAY:
  		case PASSKEY_INPUT:
  			memcpy(r, &smp->passkey, sizeof(smp->passkey));
  			break;
  		case LE_SC_OOB:
  			if (smp->oobd_local) {
  				memcpy(r, smp->oobd_local->r, sizeof(r));
  			}
  			break;
  		default:
  			BT_ERR("Unknown pairing method (%u)", smp->method);
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		/* calculate remote DHKey check for comparison */
  		if (smp_f6(smp->mackey, smp->rrnd, smp->prnd, r, &smp->prsp[1],
  			   &smp->chan.chan.conn->le.resp_addr,
  			   &smp->chan.chan.conn->le.init_addr, e)) {
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		if (memcmp(e, req->e, 16)) {
  			return BT_SMP_ERR_DHKEY_CHECK_FAILED;
  		}
  
  		enc_size = get_encryption_key_size(smp);
  
  		/* Rand and EDiv are 0 */
  		(void)memset(ediv, 0, sizeof(ediv));
  		(void)memset(rand, 0, sizeof(rand));
  		if (bt_conn_le_start_encryption(smp->chan.chan.conn, rand, ediv,
  						smp->tk, enc_size) < 0) {
  			BT_ERR("Failed to start encryption");
  			return BT_SMP_ERR_UNSPECIFIED;
  		}
  
  		atomic_set_bit(smp->flags, SMP_FLAG_ENC_PENDING);
  
  		if (IS_ENABLED(CONFIG_BT_SMP_USB_HCI_CTLR_WORKAROUND)) {
  			if (smp->remote_dist & BT_SMP_DIST_ID_KEY) {
  				atomic_set_bit(smp->allowed_cmds,
  					       BT_SMP_CMD_IDENT_INFO);
  			} else if (smp->remote_dist & BT_SMP_DIST_SIGN) {
  				atomic_set_bit(smp->allowed_cmds,
  					       BT_SMP_CMD_SIGNING_INFO);
  			}
  		}
  
  		return 0;
  	}
  
  #if defined(CONFIG_BT_PERIPHERAL)
  	if (smp->chan.chan.conn->role == BT_HCI_ROLE_SLAVE) {
  		atomic_clear_bit(smp->flags, SMP_FLAG_DHCHECK_WAIT);
  		memcpy(smp->e, req->e, sizeof(smp->e));
  
  		/* wait for DHKey being generated */
  		if (atomic_test_bit(smp->flags, SMP_FLAG_DHKEY_PENDING)) {
  			atomic_set_bit(smp->flags, SMP_FLAG_DHKEY_SEND);
  			return 0;
  		}
  
  		/* waiting for user to confirm passkey */
  		if (atomic_test_bit(smp->flags, SMP_FLAG_USER)) {
  			atomic_set_bit(smp->flags, SMP_FLAG_DHKEY_SEND);
  			return 0;
  		}
  
  		return compute_and_check_and_send_slave_dhcheck(smp);
  	}
  #endif /* CONFIG_BT_PERIPHERAL */
  
  	return 0;
  }
  
  static uint8_t smp_keypress_notif(struct bt_smp *smp, struct net_buf *buf)
  {
  	ARG_UNUSED(smp);
  	ARG_UNUSED(buf);
  
  	BT_DBG("");
  
  	/* Ignore packets until keypress notifications are fully supported. */
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_KEYPRESS_NOTIFICATION);
  	return 0;
  }
  
  static const struct {
  	uint8_t  (*func)(struct bt_smp *smp, struct net_buf *buf);
  	uint8_t  expect_len;
  } handlers[] = {
  	{ }, /* No op-code defined for 0x00 */
  	{ smp_pairing_req,         sizeof(struct bt_smp_pairing) },
  	{ smp_pairing_rsp,         sizeof(struct bt_smp_pairing) },
  	{ smp_pairing_confirm,     sizeof(struct bt_smp_pairing_confirm) },
  	{ smp_pairing_random,      sizeof(struct bt_smp_pairing_random) },
  	{ smp_pairing_failed,      sizeof(struct bt_smp_pairing_fail) },
  	{ smp_encrypt_info,        sizeof(struct bt_smp_encrypt_info) },
  	{ smp_master_ident,        sizeof(struct bt_smp_master_ident) },
  	{ smp_ident_info,          sizeof(struct bt_smp_ident_info) },
  	{ smp_ident_addr_info,     sizeof(struct bt_smp_ident_addr_info) },
  	{ smp_signing_info,        sizeof(struct bt_smp_signing_info) },
  	{ smp_security_request,    sizeof(struct bt_smp_security_request) },
  	{ smp_public_key,          sizeof(struct bt_smp_public_key) },
  	{ smp_dhkey_check,         sizeof(struct bt_smp_dhkey_check) },
  	{ smp_keypress_notif,      sizeof(struct bt_smp_keypress_notif) },
  };
  
  static int bt_smp_recv(struct bt_l2cap_chan *chan, struct net_buf *buf)
  {
  	struct bt_smp *smp = CONTAINER_OF(chan, struct bt_smp, chan);
  	struct bt_smp_hdr *hdr;
  	uint8_t err;
  
  	if (buf->len < sizeof(*hdr)) {
  		BT_ERR("Too small SMP PDU received");
  		return 0;
  	}
  
  	hdr = net_buf_pull_mem(buf, sizeof(*hdr));
  	BT_DBG("Received SMP code 0x%02x len %u", hdr->code, buf->len);
  
  	/*
  	 * If SMP timeout occurred "no further SMP commands shall be sent over
  	 * the L2CAP Security Manager Channel. A new SM procedure shall only be
  	 * performed when a new physical link has been established."
  	 */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_TIMEOUT)) {
  		BT_WARN("SMP command (code 0x%02x) received after timeout",
  			hdr->code);
  		return 0;
  	}
  
  	/*
  	 * Bluetooth Core Specification Version 5.2, Vol 3, Part H, page 1667:
  	 * If a packet is received with a Code that is reserved for future use
  	 * it shall be ignored.
  	 */
  	if (hdr->code >= ARRAY_SIZE(handlers)) {
  		BT_WARN("Received reserved SMP code 0x%02x", hdr->code);
  		return 0;
  	}
  
  	if (!handlers[hdr->code].func) {
  		BT_WARN("Unhandled SMP code 0x%02x", hdr->code);
  		smp_error(smp, BT_SMP_ERR_CMD_NOTSUPP);
  		return 0;
  	}
  
  	if (!atomic_test_and_clear_bit(smp->allowed_cmds, hdr->code)) {
  		BT_WARN("Unexpected SMP code 0x%02x", hdr->code);
  		/* Don't send error responses to error PDUs */
  		if (hdr->code != BT_SMP_CMD_PAIRING_FAIL) {
  			smp_error(smp, BT_SMP_ERR_UNSPECIFIED);
  		}
  		return 0;
  	}
  
  	if (buf->len != handlers[hdr->code].expect_len) {
  		BT_ERR("Invalid len %u for code 0x%02x", buf->len, hdr->code);
  		smp_error(smp, BT_SMP_ERR_INVALID_PARAMS);
  		return 0;
  	}
  
  	err = handlers[hdr->code].func(smp, buf);
  	if (err) {
  		smp_error(smp, err);
  	}
  
  	return 0;
  }
  
  static void bt_smp_pkey_ready(const uint8_t *pkey)
  {
  	int i;
  
  	BT_DBG("");
  
  	sc_public_key = pkey;
  
  	if (!pkey) {
  		BT_WARN("Public key not available");
  		return;
  	}
  
  	k_sem_give(&sc_local_pkey_ready);
  
  	for (i = 0; i < ARRAY_SIZE(bt_smp_pool); i++) {
  		struct bt_smp *smp = &bt_smp_pool[i];
  		uint8_t err;
  
  		if (!atomic_test_bit(smp->flags, SMP_FLAG_PKEY_SEND)) {
  			continue;
  		}
  
  		if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  		    smp->chan.chan.conn->role == BT_HCI_ROLE_MASTER) {
  			err = sc_send_public_key(smp);
  			if (err) {
  				smp_error(smp, err);
  			}
  
  			atomic_set_bit(smp->allowed_cmds,
  				       BT_SMP_CMD_PUBLIC_KEY);
  			continue;
  		}
  
  #if defined(CONFIG_BT_PERIPHERAL)
  		err = smp_public_key_slave(smp);
  		if (err) {
  			smp_error(smp, err);
  		}
  #endif /* CONFIG_BT_PERIPHERAL */
  	}
  }
  
  static void bt_smp_connected(struct bt_l2cap_chan *chan)
  {
  	struct bt_smp *smp = CONTAINER_OF(chan, struct bt_smp, chan);
  
  	BT_DBG("chan %p cid 0x%04x", chan,
  	       CONTAINER_OF(chan, struct bt_l2cap_le_chan, chan)->tx.cid);
  
  	k_delayed_work_init(&smp->work, smp_timeout);
  	smp_reset(smp);
  }
  
  static void bt_smp_disconnected(struct bt_l2cap_chan *chan)
  {
  	struct bt_smp *smp = CONTAINER_OF(chan, struct bt_smp, chan);
  	struct bt_keys *keys = chan->conn->le.keys;
  
  	BT_DBG("chan %p cid 0x%04x", chan,
  	       CONTAINER_OF(chan, struct bt_l2cap_le_chan, chan)->tx.cid);
  
  	k_delayed_work_cancel(&smp->work);
  
  	if (atomic_test_bit(smp->flags, SMP_FLAG_PAIRING) ||
  	    atomic_test_bit(smp->flags, SMP_FLAG_ENC_PENDING) ||
  	    atomic_test_bit(smp->flags, SMP_FLAG_SEC_REQ)) {
  		/* reset context and report */
  		smp_pairing_complete(smp, BT_SMP_ERR_UNSPECIFIED);
  	}
  
  	if (keys) {
  		/*
  		 * If debug keys were used for pairing remove them.
  		 * No keys indicate no bonding so free keys storage.
  		 */
  		if (!keys->keys || (!IS_ENABLED(CONFIG_BT_STORE_DEBUG_KEYS) &&
  		    (keys->flags & BT_KEYS_DEBUG))) {
  			bt_keys_clear(keys);
  		}
  	}
  
  	(void)memset(smp, 0, sizeof(*smp));
  }
  
  static void bt_smp_encrypt_change(struct bt_l2cap_chan *chan,
  				  uint8_t hci_status)
  {
  	struct bt_smp *smp = CONTAINER_OF(chan, struct bt_smp, chan);
  	struct bt_conn *conn = chan->conn;
  
  	BT_DBG("chan %p conn %p handle %u encrypt 0x%02x hci status 0x%02x",
  	       chan, conn, conn->handle, conn->encrypt, hci_status);
  
  	if (!atomic_test_and_clear_bit(smp->flags, SMP_FLAG_ENC_PENDING)) {
  		/* We where not waiting for encryption procedure.
  		 * This happens when encrypt change is called to notify that
  		 * security has failed before starting encryption.
  		 */
  		return;
  	}
  
  	if (hci_status) {
  		if (atomic_test_bit(smp->flags, SMP_FLAG_PAIRING)) {
  			uint8_t smp_err = smp_err_get(
  				bt_security_err_get(hci_status));
  
  			/* Fail as if it happened during key distribution */
  			atomic_set_bit(smp->flags, SMP_FLAG_KEYS_DISTR);
  			smp_pairing_complete(smp, smp_err);
  		}
  
  		return;
  	}
  
  	if (!conn->encrypt) {
  		return;
  	}
  
  	/* We were waiting for encryption but with no pairing in progress.
  	 * This can happen if paired slave sent Security Request and we
  	 * enabled encryption.
  	 */
  	if (!atomic_test_bit(smp->flags, SMP_FLAG_PAIRING)) {
  		smp_reset(smp);
  		return;
  	}
  
  	/* derive BR/EDR LinkKey if supported by both sides */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_SC)) {
  		if ((smp->local_dist & BT_SMP_DIST_LINK_KEY) &&
  		    (smp->remote_dist & BT_SMP_DIST_LINK_KEY)) {
  			/*
  			 * Link Key will be derived after key distribution to
  			 * make sure remote device identity is known
  			 */
  			atomic_set_bit(smp->flags, SMP_FLAG_DERIVE_LK);
  		}
  		/*
  		 * Those are used as pairing finished indicator so generated
  		 * but not distributed keys must be cleared here.
  		 */
  		smp->local_dist &= ~BT_SMP_DIST_LINK_KEY;
  		smp->remote_dist &= ~BT_SMP_DIST_LINK_KEY;
  	}
  
  	if (smp->remote_dist & BT_SMP_DIST_ENC_KEY) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_ENCRYPT_INFO);
  	} else if (smp->remote_dist & BT_SMP_DIST_ID_KEY) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_IDENT_INFO);
  	} else if (smp->remote_dist & BT_SMP_DIST_SIGN) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_SIGNING_INFO);
  	}
  
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    IS_ENABLED(CONFIG_BT_PRIVACY) &&
  	    !(smp->remote_dist & BT_SMP_DIST_ID_KEY)) {
  		/* To resolve directed advertising we need our local IRK
  		 * in the controllers resolving list, add it now since the
  		 * peer has no identity key.
  		 */
  		bt_id_add(conn->le.keys);
  	}
  
  	atomic_set_bit(smp->flags, SMP_FLAG_KEYS_DISTR);
  
  	/* Slave distributes it's keys first */
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    conn->role == BT_HCI_ROLE_MASTER && smp->remote_dist) {
  		return;
  	}
  
  	if (IS_ENABLED(CONFIG_BT_TESTING)) {
  		/* Avoid the HCI-USB race condition where HCI data and
  		 * HCI events can be re-ordered, and pairing information appears
  		 * to be sent unencrypted.
  		 */
  		k_sleep(K_MSEC(100));
  	}
  
  	if (bt_smp_distribute_keys(smp)) {
  		return;
  	}
  
  	/* if all keys were distributed, pairing is done */
  	if (!smp->local_dist && !smp->remote_dist) {
  		smp_pairing_complete(smp, 0);
  	}
  }
  
  #if defined(CONFIG_BT_SIGNING) || defined(CONFIG_BT_SMP_SELFTEST)
  /* Sign message using msg as a buffer, len is a size of the message,
   * msg buffer contains message itself, 32 bit count and signature,
   * so total buffer size is len + 4 + 8 octets.
   * API is Little Endian to make it suitable for Bluetooth.
   */
  static int smp_sign_buf(const uint8_t *key, uint8_t *msg, uint16_t len)
  {
  	uint8_t *m = msg;
  	uint32_t cnt = UNALIGNED_GET((uint32_t *)&msg[len]);
  	uint8_t *sig = msg + len;
  	uint8_t key_s[16], tmp[16];
  	int err;
  
  	BT_DBG("Signing msg %s len %u key %s", bt_hex(msg, len), len,
  	       bt_hex(key, 16));
  
  	sys_mem_swap(m, len + sizeof(cnt));
  	sys_memcpy_swap(key_s, key, 16);
  
  	err = bt_smp_aes_cmac(key_s, m, len + sizeof(cnt), tmp);
  	if (err) {
  		BT_ERR("Data signing failed");
  		return err;
  	}
  
  	sys_mem_swap(tmp, sizeof(tmp));
  	memcpy(tmp + 4, &cnt, sizeof(cnt));
  
  	/* Swap original message back */
  	sys_mem_swap(m, len + sizeof(cnt));
  
  	memcpy(sig, tmp + 4, 12);
  
  	BT_DBG("sig %s", bt_hex(sig, 12));
  
  	return 0;
  }
  #endif
  
  #if defined(CONFIG_BT_SIGNING)
  int bt_smp_sign_verify(struct bt_conn *conn, struct net_buf *buf)
  {
  	struct bt_keys *keys;
  	uint8_t sig[12];
  	uint32_t cnt;
  	int err;
  
  	/* Store signature incl. count */
  	memcpy(sig, net_buf_tail(buf) - sizeof(sig), sizeof(sig));
  
  	keys = bt_keys_find(BT_KEYS_REMOTE_CSRK, conn->id, &conn->le.dst);
  	if (!keys) {
  		BT_ERR("Unable to find Remote CSRK for %s",
  		       bt_addr_le_str(&conn->le.dst));
  		return -ENOENT;
  	}
  
  	/* Copy signing count */
  	cnt = sys_cpu_to_le32(keys->remote_csrk.cnt);
  	memcpy(net_buf_tail(buf) - sizeof(sig), &cnt, sizeof(cnt));
  
  	BT_DBG("Sign data len %zu key %s count %u", buf->len - sizeof(sig),
  	       bt_hex(keys->remote_csrk.val, 16), keys->remote_csrk.cnt);
  
  	err = smp_sign_buf(keys->remote_csrk.val, buf->data,
  			   buf->len - sizeof(sig));
  	if (err) {
  		BT_ERR("Unable to create signature for %s",
  		       bt_addr_le_str(&conn->le.dst));
  		return -EIO;
  	}
  
  	if (memcmp(sig, net_buf_tail(buf) - sizeof(sig), sizeof(sig))) {
  		BT_ERR("Unable to verify signature for %s",
  		       bt_addr_le_str(&conn->le.dst));
  		return -EBADMSG;
  	}
  
  	keys->remote_csrk.cnt++;
  
  	return 0;
  }
  
  int bt_smp_sign(struct bt_conn *conn, struct net_buf *buf)
  {
  	struct bt_keys *keys;
  	uint32_t cnt;
  	int err;
  
  	keys = bt_keys_find(BT_KEYS_LOCAL_CSRK, conn->id, &conn->le.dst);
  	if (!keys) {
  		BT_ERR("Unable to find local CSRK for %s",
  		       bt_addr_le_str(&conn->le.dst));
  		return -ENOENT;
  	}
  
  	/* Reserve space for data signature */
  	net_buf_add(buf, 12);
  
  	/* Copy signing count */
  	cnt = sys_cpu_to_le32(keys->local_csrk.cnt);
  	memcpy(net_buf_tail(buf) - 12, &cnt, sizeof(cnt));
  
  	BT_DBG("Sign data len %u key %s count %u", buf->len,
  	       bt_hex(keys->local_csrk.val, 16), keys->local_csrk.cnt);
  
  	err = smp_sign_buf(keys->local_csrk.val, buf->data, buf->len - 12);
  	if (err) {
  		BT_ERR("Unable to create signature for %s",
  		       bt_addr_le_str(&conn->le.dst));
  		return -EIO;
  	}
  
  	keys->local_csrk.cnt++;
  
  	return 0;
  }
  #else
  int bt_smp_sign_verify(struct bt_conn *conn, struct net_buf *buf)
  {
  	return -ENOTSUP;
  }
  
  int bt_smp_sign(struct bt_conn *conn, struct net_buf *buf)
  {
  	return -ENOTSUP;
  }
  #endif /* CONFIG_BT_SIGNING */
  
  int bt_smp_irk_get(uint8_t *ir, uint8_t *irk)
  {
  	uint8_t invalid_ir[16] = { 0 };
  
  	if (!memcmp(ir, invalid_ir, 16)) {
  		return -EINVAL;
  	}
  
  	return smp_d1(ir, 1, 0, irk);
  }
  
  #if defined(CONFIG_BT_SMP_SELFTEST)
  /* Test vectors are taken from RFC 4493
   * https://tools.ietf.org/html/rfc4493
   * Same mentioned in the Bluetooth Spec.
   */
  static const uint8_t key[] = {
  	0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6,
  	0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c
  };
  
  static const uint8_t M[] = {
  	0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96,
  	0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
  	0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c,
  	0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
  	0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11,
  	0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
  	0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17,
  	0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10
  };
  
  static int aes_test(const char *prefix, const uint8_t *key, const uint8_t *m,
  		    uint16_t len, const uint8_t *mac)
  {
  	uint8_t out[16];
  
  	BT_DBG("%s: AES CMAC of message with len %u", prefix, len);
  
  	bt_smp_aes_cmac(key, m, len, out);
  	if (!memcmp(out, mac, 16)) {
  		BT_DBG("%s: Success", prefix);
  	} else {
  		BT_ERR("%s: Failed", prefix);
  		return -1;
  	}
  
  	return 0;
  }
  
  static int smp_aes_cmac_test(void)
  {
  	uint8_t mac1[] = {
  		0xbb, 0x1d, 0x69, 0x29, 0xe9, 0x59, 0x37, 0x28,
  		0x7f, 0xa3, 0x7d, 0x12, 0x9b, 0x75, 0x67, 0x46
  	};
  	uint8_t mac2[] = {
  		0x07, 0x0a, 0x16, 0xb4, 0x6b, 0x4d, 0x41, 0x44,
  		0xf7, 0x9b, 0xdd, 0x9d, 0xd0, 0x4a, 0x28, 0x7c
  	};
  	uint8_t mac3[] = {
  		0xdf, 0xa6, 0x67, 0x47, 0xde, 0x9a, 0xe6, 0x30,
  		0x30, 0xca, 0x32, 0x61, 0x14, 0x97, 0xc8, 0x27
  	};
  	uint8_t mac4[] = {
  		0x51, 0xf0, 0xbe, 0xbf, 0x7e, 0x3b, 0x9d, 0x92,
  		0xfc, 0x49, 0x74, 0x17, 0x79, 0x36, 0x3c, 0xfe
  	};
  	int err;
  
  	err = aes_test("Test aes-cmac0", key, M, 0, mac1);
  	if (err) {
  		return err;
  	}
  
  	err = aes_test("Test aes-cmac16", key, M, 16, mac2);
  	if (err) {
  		return err;
  	}
  
  	err = aes_test("Test aes-cmac40", key, M, 40, mac3);
  	if (err) {
  		return err;
  	}
  
  	err = aes_test("Test aes-cmac64", key, M, 64, mac4);
  	if (err) {
  		return err;
  	}
  
  	return 0;
  }
  
  static int sign_test(const char *prefix, const uint8_t *key, const uint8_t *m,
  		     uint16_t len, const uint8_t *sig)
  {
  	uint8_t msg[len + sizeof(uint32_t) + 8];
  	uint8_t orig[len + sizeof(uint32_t) + 8];
  	uint8_t *out = msg + len;
  	int err;
  
  	BT_DBG("%s: Sign message with len %u", prefix, len);
  
  	(void)memset(msg, 0, sizeof(msg));
  	memcpy(msg, m, len);
  	(void)memset(msg + len, 0, sizeof(uint32_t));
  
  	memcpy(orig, msg, sizeof(msg));
  
  	err = smp_sign_buf(key, msg, len);
  	if (err) {
  		return err;
  	}
  
  	/* Check original message */
  	if (!memcmp(msg, orig, len + sizeof(uint32_t))) {
  		BT_DBG("%s: Original message intact", prefix);
  	} else {
  		BT_ERR("%s: Original message modified", prefix);
  		BT_DBG("%s: orig %s", prefix, bt_hex(orig, sizeof(orig)));
  		BT_DBG("%s: msg %s", prefix, bt_hex(msg, sizeof(msg)));
  		return -1;
  	}
  
  	if (!memcmp(out, sig, 12)) {
  		BT_DBG("%s: Success", prefix);
  	} else {
  		BT_ERR("%s: Failed", prefix);
  		return -1;
  	}
  
  	return 0;
  }
  
  static int smp_sign_test(void)
  {
  	const uint8_t sig1[] = {
  		0x00, 0x00, 0x00, 0x00, 0xb3, 0xa8, 0x59, 0x41,
  		0x27, 0xeb, 0xc2, 0xc0
  	};
  	const uint8_t sig2[] = {
  		0x00, 0x00, 0x00, 0x00, 0x27, 0x39, 0x74, 0xf4,
  		0x39, 0x2a, 0x23, 0x2a
  	};
  	const uint8_t sig3[] = {
  		0x00, 0x00, 0x00, 0x00, 0xb7, 0xca, 0x94, 0xab,
  		0x87, 0xc7, 0x82, 0x18
  	};
  	const uint8_t sig4[] = {
  		0x00, 0x00, 0x00, 0x00, 0x44, 0xe1, 0xe6, 0xce,
  		0x1d, 0xf5, 0x13, 0x68
  	};
  	uint8_t key_s[16];
  	int err;
  
  	/* Use the same key as aes-cmac but swap bytes */
  	sys_memcpy_swap(key_s, key, 16);
  
  	err = sign_test("Test sign0", key_s, M, 0, sig1);
  	if (err) {
  		return err;
  	}
  
  	err = sign_test("Test sign16", key_s, M, 16, sig2);
  	if (err) {
  		return err;
  	}
  
  	err = sign_test("Test sign40", key_s, M, 40, sig3);
  	if (err) {
  		return err;
  	}
  
  	err = sign_test("Test sign64", key_s, M, 64, sig4);
  	if (err) {
  		return err;
  	}
  
  	return 0;
  }
  
  static int smp_f4_test(void)
  {
  	uint8_t u[32] = { 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
  			  0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
  			  0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
  			  0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
  	uint8_t v[32] = { 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
  			  0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
  			  0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
  			  0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
  	uint8_t x[16] = { 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
  			  0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
  	uint8_t z = 0x00;
  	uint8_t exp[16] = { 0x2d, 0x87, 0x74, 0xa9, 0xbe, 0xa1, 0xed, 0xf1,
  			    0x1c, 0xbd, 0xa9, 0x07, 0xf1, 0x16, 0xc9, 0xf2 };
  	uint8_t res[16];
  	int err;
  
  	err = smp_f4(u, v, x, z, res);
  	if (err) {
  		return err;
  	}
  
  	if (memcmp(res, exp, 16)) {
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static int smp_f5_test(void)
  {
  	uint8_t w[32] = { 0x98, 0xa6, 0xbf, 0x73, 0xf3, 0x34, 0x8d, 0x86,
  			  0xf1, 0x66, 0xf8, 0xb4, 0x13, 0x6b, 0x79, 0x99,
  			  0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
  			  0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
  	uint8_t n1[16] = { 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
  			   0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
  	uint8_t n2[16] = { 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
  			   0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
  	bt_addr_le_t a1 = { .type = 0x00,
  			    .a.val = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56 } };
  	bt_addr_le_t a2 = { .type = 0x00,
  			    .a.val = {0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7 } };
  	uint8_t exp_ltk[16] = { 0x38, 0x0a, 0x75, 0x94, 0xb5, 0x22, 0x05,
  				0x98, 0x23, 0xcd, 0xd7, 0x69, 0x11, 0x79,
  				0x86, 0x69 };
  	uint8_t exp_mackey[16] = { 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f,
  				   0xfd, 0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1,
  				   0x65, 0x29 };
  	uint8_t mackey[16], ltk[16];
  	int err;
  
  	err = smp_f5(w, n1, n2, &a1, &a2, mackey, ltk);
  	if (err) {
  		return err;
  	}
  
  	if (memcmp(mackey, exp_mackey, 16) || memcmp(ltk, exp_ltk, 16)) {
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static int smp_f6_test(void)
  {
  	uint8_t w[16] = { 0x20, 0x6e, 0x63, 0xce, 0x20, 0x6a, 0x3f, 0xfd,
  			  0x02, 0x4a, 0x08, 0xa1, 0x76, 0xf1, 0x65, 0x29 };
  	uint8_t n1[16] = { 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
  			   0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
  	uint8_t n2[16] = { 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
  			   0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
  	uint8_t r[16] = { 0xc8, 0x0f, 0x2d, 0x0c, 0xd2, 0x42, 0xda, 0x08,
  			  0x54, 0xbb, 0x53, 0xb4, 0x3b, 0x34, 0xa3, 0x12 };
  	uint8_t io_cap[3] = { 0x02, 0x01, 0x01 };
  	bt_addr_le_t a1 = { .type = 0x00,
  			    .a.val = { 0xce, 0xbf, 0x37, 0x37, 0x12, 0x56 } };
  	bt_addr_le_t a2 = { .type = 0x00,
  			    .a.val = {0xc1, 0xcf, 0x2d, 0x70, 0x13, 0xa7 } };
  	uint8_t exp[16] = { 0x61, 0x8f, 0x95, 0xda, 0x09, 0x0b, 0x6c, 0xd2,
  			    0xc5, 0xe8, 0xd0, 0x9c, 0x98, 0x73, 0xc4, 0xe3 };
  	uint8_t res[16];
  	int err;
  
  	err = smp_f6(w, n1, n2, r, io_cap, &a1, &a2, res);
  	if (err)
  		return err;
  
  	if (memcmp(res, exp, 16))
  		return -EINVAL;
  
  	return 0;
  }
  
  static int smp_g2_test(void)
  {
  	uint8_t u[32] = { 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,
  			  0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,
  			  0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,
  			  0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20 };
  	uint8_t v[32] = { 0xfd, 0xc5, 0x7f, 0xf4, 0x49, 0xdd, 0x4f, 0x6b,
  			  0xfb, 0x7c, 0x9d, 0xf1, 0xc2, 0x9a, 0xcb, 0x59,
  			  0x2a, 0xe7, 0xd4, 0xee, 0xfb, 0xfc, 0x0a, 0x90,
  			  0x9a, 0xbb, 0xf6, 0x32, 0x3d, 0x8b, 0x18, 0x55 };
  	uint8_t x[16] = { 0xab, 0xae, 0x2b, 0x71, 0xec, 0xb2, 0xff, 0xff,
  			  0x3e, 0x73, 0x77, 0xd1, 0x54, 0x84, 0xcb, 0xd5 };
  	uint8_t y[16] = { 0xcf, 0xc4, 0x3d, 0xff, 0xf7, 0x83, 0x65, 0x21,
  			  0x6e, 0x5f, 0xa7, 0x25, 0xcc, 0xe7, 0xe8, 0xa6 };
  	uint32_t exp_val = 0x2f9ed5ba % 1000000;
  	uint32_t val;
  	int err;
  
  	err = smp_g2(u, v, x, y, &val);
  	if (err) {
  		return err;
  	}
  
  	if (val != exp_val) {
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  #if defined(CONFIG_BT_BREDR)
  static int smp_h6_test(void)
  {
  	uint8_t w[16] = { 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
  			  0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
  	uint8_t key_id[4] = { 0x72, 0x62, 0x65, 0x6c };
  	uint8_t exp_res[16] = { 0x99, 0x63, 0xb1, 0x80, 0xe2, 0xa9, 0xd3, 0xe8,
  				0x1c, 0xc9, 0x6d, 0xe7, 0x02, 0xe1, 0x9a, 0x2d};
  	uint8_t res[16];
  	int err;
  
  	err = smp_h6(w, key_id, res);
  	if (err) {
  		return err;
  	}
  
  	if (memcmp(res, exp_res, 16)) {
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static int smp_h7_test(void)
  {
  	uint8_t salt[16] = { 0x31, 0x70, 0x6d, 0x74, 0x00, 0x00, 0x00, 0x00,
  			     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
  	uint8_t w[16] = { 0x9b, 0x7d, 0x39, 0x0a, 0xa6, 0x10, 0x10, 0x34,
  			  0x05, 0xad, 0xc8, 0x57, 0xa3, 0x34, 0x02, 0xec };
  	uint8_t exp_res[16] = { 0x11, 0x70, 0xa5, 0x75, 0x2a, 0x8c, 0x99, 0xd2,
  				0xec, 0xc0, 0xa3, 0xc6, 0x97, 0x35, 0x17, 0xfb};
  	uint8_t res[16];
  	int err;
  
  	err = smp_h7(salt, w, res);
  	if (err) {
  		return err;
  	}
  
  	if (memcmp(res, exp_res, 16)) {
  		return -EINVAL;
  	}
  
  	return 0;
  }
  #endif /* CONFIG_BT_BREDR */
  
  static int smp_self_test(void)
  {
  	int err;
  
  	err = smp_aes_cmac_test();
  	if (err) {
  		BT_ERR("SMP AES-CMAC self tests failed");
  		return err;
  	}
  
  	err = smp_sign_test();
  	if (err) {
  		BT_ERR("SMP signing self tests failed");
  		return err;
  	}
  
  	err = smp_f4_test();
  	if (err) {
  		BT_ERR("SMP f4 self test failed");
  		return err;
  	}
  
  	err = smp_f5_test();
  	if (err) {
  		BT_ERR("SMP f5 self test failed");
  		return err;
  	}
  
  	err = smp_f6_test();
  	if (err) {
  		BT_ERR("SMP f6 self test failed");
  		return err;
  	}
  
  	err = smp_g2_test();
  	if (err) {
  		BT_ERR("SMP g2 self test failed");
  		return err;
  	}
  
  #if defined(CONFIG_BT_BREDR)
  	err = smp_h6_test();
  	if (err) {
  		BT_ERR("SMP h6 self test failed");
  		return err;
  	}
  
  	err = smp_h7_test();
  	if (err) {
  		BT_ERR("SMP h7 self test failed");
  		return err;
  	}
  #endif /* CONFIG_BT_BREDR */
  
  	return 0;
  }
  #else
  static inline int smp_self_test(void)
  {
  	return 0;
  }
  #endif
  
  int bt_smp_auth_passkey_entry(struct bt_conn *conn, unsigned int passkey)
  {
  	struct bt_smp *smp;
  	uint8_t err;
  
  	smp = smp_chan_get(conn);
  	if (!smp) {
  		return -EINVAL;
  	}
  
  	if (!atomic_test_and_clear_bit(smp->flags, SMP_FLAG_USER)) {
  		return -EINVAL;
  	}
  
  #if !defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
  	if (!atomic_test_bit(smp->flags, SMP_FLAG_SC)) {
  		legacy_passkey_entry(smp, passkey);
  		return 0;
  	}
  #endif /* !CONFIG_BT_SMP_SC_PAIR_ONLY */
  
  	smp->passkey = sys_cpu_to_le32(passkey);
  
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    smp->chan.chan.conn->role == BT_HCI_ROLE_MASTER) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_CONFIRM);
  		err = smp_send_pairing_confirm(smp);
  		if (err) {
  			smp_error(smp, BT_SMP_ERR_PASSKEY_ENTRY_FAILED);
  			return 0;
  		}
  		return 0;
  	}
  
  	if (IS_ENABLED(CONFIG_BT_PERIPHERAL) &&
  	    atomic_test_bit(smp->flags, SMP_FLAG_CFM_DELAYED)) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_RANDOM);
  		err = smp_send_pairing_confirm(smp);
  		if (err) {
  			smp_error(smp, BT_SMP_ERR_PASSKEY_ENTRY_FAILED);
  			return 0;
  		}
  	}
  
  	return 0;
  }
  
  int bt_smp_auth_passkey_confirm(struct bt_conn *conn)
  {
  	struct bt_smp *smp;
  
  	smp = smp_chan_get(conn);
  	if (!smp) {
  		return -EINVAL;
  	}
  
  	if (!atomic_test_and_clear_bit(smp->flags, SMP_FLAG_USER)) {
  		return -EINVAL;
  	}
  
  	/* wait for DHKey being generated */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_DHKEY_PENDING)) {
  		atomic_set_bit(smp->flags, SMP_FLAG_DHKEY_SEND);
  		return 0;
  	}
  
  	/* wait for remote DHKey Check */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_DHCHECK_WAIT)) {
  		atomic_set_bit(smp->flags, SMP_FLAG_DHKEY_SEND);
  		return 0;
  	}
  
  	if (atomic_test_bit(smp->flags, SMP_FLAG_DHKEY_SEND)) {
  		uint8_t err;
  
  #if defined(CONFIG_BT_CENTRAL)
  		if (smp->chan.chan.conn->role == BT_HCI_ROLE_MASTER) {
  			err = compute_and_send_master_dhcheck(smp);
  			if (err) {
  				smp_error(smp, err);
  			}
  			return 0;
  		}
  #endif /* CONFIG_BT_CENTRAL */
  
  #if defined(CONFIG_BT_PERIPHERAL)
  		err = compute_and_check_and_send_slave_dhcheck(smp);
  		if (err) {
  			smp_error(smp, err);
  		}
  #endif /* CONFIG_BT_PERIPHERAL */
  	}
  
  	return 0;
  }
  
  #if !defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
  int bt_smp_le_oob_set_tk(struct bt_conn *conn, const uint8_t *tk)
  {
  	struct bt_smp *smp;
  
  	smp = smp_chan_get(conn);
  	if (!smp || !tk) {
  		return -EINVAL;
  	}
  
  	BT_DBG("%s", bt_hex(tk, 16));
  
  	if (!atomic_test_and_clear_bit(smp->flags, SMP_FLAG_USER)) {
  		return -EINVAL;
  	}
  
  	if (IS_ENABLED(CONFIG_BT_LOG_SNIFFER_INFO)) {
  		uint8_t oob[16];
  
  		sys_memcpy_swap(oob, tk, 16);
  		BT_INFO("Legacy OOB data 0x%s", bt_hex(oob, 16));
  	}
  
  	memcpy(smp->tk, tk, 16*sizeof(uint8_t));
  
  	legacy_user_tk_entry(smp);
  
  	return 0;
  }
  #endif /* !defined(CONFIG_BT_SMP_SC_PAIR_ONLY) */
  
  int bt_smp_le_oob_generate_sc_data(struct bt_le_oob_sc_data *le_sc_oob)
  {
  	int err;
  
  	if (!le_sc_supported()) {
  		return -ENOTSUP;
  	}
  
  	if (!sc_public_key) {
  		err = k_sem_take(&sc_local_pkey_ready, K_FOREVER);
  		if (err) {
  			return err;
  		}
  	}
  
  	if (IS_ENABLED(CONFIG_BT_OOB_DATA_FIXED)) {
  		uint8_t rand_num[] = {
  			0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
  			0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
  		};
  
  		memcpy(le_sc_oob->r, rand_num, sizeof(le_sc_oob->r));
  	} else {
  		err = bt_rand(le_sc_oob->r, 16);
  		if (err) {
  			return err;
  		}
  	}
  
  	err = smp_f4(sc_public_key, sc_public_key, le_sc_oob->r, 0,
  		     le_sc_oob->c);
  	if (err) {
  		return err;
  	}
  
  	return 0;
  }
  
  #if !defined(CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY)
  static bool le_sc_oob_data_check(struct bt_smp *smp, bool oobd_local_present,
  				 bool oobd_remote_present)
  {
  	bool req_oob_present = le_sc_oob_data_req_check(smp);
  	bool rsp_oob_present = le_sc_oob_data_rsp_check(smp);
  
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    smp->chan.chan.conn->role == BT_HCI_ROLE_MASTER) {
  		if ((req_oob_present != oobd_remote_present) &&
  		    (rsp_oob_present != oobd_local_present)) {
  			return false;
  		}
  	} else if (IS_ENABLED(CONFIG_BT_PERIPHERAL)) {
  		if ((req_oob_present != oobd_local_present) &&
  		    (rsp_oob_present != oobd_remote_present)) {
  			return false;
  		}
  	}
  
  	return true;
  }
  
  static int le_sc_oob_pairing_continue(struct bt_smp *smp)
  {
  	if (smp->oobd_remote) {
  		int err;
  		uint8_t c[16];
  
  		err = smp_f4(smp->pkey, smp->pkey, smp->oobd_remote->r, 0, c);
  		if (err) {
  			return err;
  		}
  
  		bool match = (memcmp(c, smp->oobd_remote->c, sizeof(c)) == 0);
  
  		if (!match) {
  			smp_error(smp, BT_SMP_ERR_CONFIRM_FAILED);
  			return 0;
  		}
  	}
  
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    smp->chan.chan.conn->role == BT_HCI_ROLE_MASTER) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PAIRING_RANDOM);
  	} else if (IS_ENABLED(CONFIG_BT_PERIPHERAL)) {
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_DHKEY_CHECK);
  		atomic_set_bit(smp->flags, SMP_FLAG_DHCHECK_WAIT);
  	}
  
  	return smp_send_pairing_random(smp);
  }
  
  int bt_smp_le_oob_set_sc_data(struct bt_conn *conn,
  			      const struct bt_le_oob_sc_data *oobd_local,
  			      const struct bt_le_oob_sc_data *oobd_remote)
  {
  	struct bt_smp *smp;
  
  	smp = smp_chan_get(conn);
  	if (!smp) {
  		return -EINVAL;
  	}
  
  	if (!le_sc_oob_data_check(smp, (oobd_local != NULL),
  				  (oobd_remote != NULL))) {
  		return -EINVAL;
  	}
  
  	if (!atomic_test_and_clear_bit(smp->flags, SMP_FLAG_OOB_PENDING)) {
  		return -EINVAL;
  	}
  
  	smp->oobd_local = oobd_local;
  	smp->oobd_remote = oobd_remote;
  
  	return le_sc_oob_pairing_continue(smp);
  }
  
  int bt_smp_le_oob_get_sc_data(struct bt_conn *conn,
  			      const struct bt_le_oob_sc_data **oobd_local,
  			      const struct bt_le_oob_sc_data **oobd_remote)
  {
  	struct bt_smp *smp;
  
  	smp = smp_chan_get(conn);
  	if (!smp) {
  		return -EINVAL;
  	}
  
  	if (!smp->oobd_local && !smp->oobd_remote) {
  		return -ESRCH;
  	}
  
  	if (oobd_local) {
  		*oobd_local = smp->oobd_local;
  	}
  
  	if (oobd_remote) {
  		*oobd_remote = smp->oobd_remote;
  	}
  
  	return 0;
  }
  #endif /* !CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY */
  
  int bt_smp_auth_cancel(struct bt_conn *conn)
  {
  	struct bt_smp *smp;
  
  	smp = smp_chan_get(conn);
  	if (!smp) {
  		return -EINVAL;
  	}
  
  	if (!atomic_test_and_clear_bit(smp->flags, SMP_FLAG_USER)) {
  		return -EINVAL;
  	}
  
  	BT_DBG("");
  
  	switch (smp->method) {
  	case PASSKEY_INPUT:
  	case PASSKEY_DISPLAY:
  		return smp_error(smp, BT_SMP_ERR_PASSKEY_ENTRY_FAILED);
  	case PASSKEY_CONFIRM:
  		return smp_error(smp, BT_SMP_ERR_CONFIRM_FAILED);
  	case LE_SC_OOB:
  	case LEGACY_OOB:
  		return smp_error(smp, BT_SMP_ERR_OOB_NOT_AVAIL);
  	case JUST_WORKS:
  		return smp_error(smp, BT_SMP_ERR_UNSPECIFIED);
  	default:
  		BT_ERR("Unknown pairing method (%u)", smp->method);
  		return 0;
  	}
  }
  
  #if !defined(CONFIG_BT_SMP_SC_PAIR_ONLY)
  int bt_smp_auth_pairing_confirm(struct bt_conn *conn)
  {
  	struct bt_smp *smp;
  
  	smp = smp_chan_get(conn);
  	if (!smp) {
  		return -EINVAL;
  	}
  
  	if (!atomic_test_and_clear_bit(smp->flags, SMP_FLAG_USER)) {
  		return -EINVAL;
  	}
  
  	if (IS_ENABLED(CONFIG_BT_CENTRAL) &&
  	    conn->role == BT_CONN_ROLE_MASTER) {
  		if (!atomic_test_bit(smp->flags, SMP_FLAG_SC)) {
  			atomic_set_bit(smp->allowed_cmds,
  				       BT_SMP_CMD_PAIRING_CONFIRM);
  			return legacy_send_pairing_confirm(smp);
  		}
  
  		if (!sc_public_key) {
  			atomic_set_bit(smp->flags, SMP_FLAG_PKEY_SEND);
  			return 0;
  		}
  
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PUBLIC_KEY);
  		return sc_send_public_key(smp);
  	}
  
  #if defined(CONFIG_BT_PERIPHERAL)
  	if (!atomic_test_bit(smp->flags, SMP_FLAG_SC)) {
  		atomic_set_bit(smp->allowed_cmds,
  			       BT_SMP_CMD_PAIRING_CONFIRM);
  		return send_pairing_rsp(smp);
  	}
  
  	atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_PUBLIC_KEY);
  	if (send_pairing_rsp(smp)) {
  		return -EIO;
  	}
  #endif /* CONFIG_BT_PERIPHERAL */
  
  	return 0;
  }
  #else
  int bt_smp_auth_pairing_confirm(struct bt_conn *conn)
  {
  	/* confirm_pairing will never be called in LE SC only mode */
  	return -EINVAL;
  }
  #endif /* !CONFIG_BT_SMP_SC_PAIR_ONLY */
  
  #if defined(CONFIG_BT_FIXED_PASSKEY)
  int bt_passkey_set(unsigned int passkey)
  {
  	if (passkey == BT_PASSKEY_INVALID) {
  		fixed_passkey = BT_PASSKEY_INVALID;
  		return 0;
  	}
  
  	if (passkey > 999999) {
  		return -EINVAL;
  	}
  
  	fixed_passkey = passkey;
  	return 0;
  }
  #endif /* CONFIG_BT_FIXED_PASSKEY */
  
  int bt_smp_start_security(struct bt_conn *conn)
  {
  	switch (conn->role) {
  #if defined(CONFIG_BT_CENTRAL)
  	case BT_HCI_ROLE_MASTER:
  	{
  		int err;
  		struct bt_smp *smp;
  
  		smp = smp_chan_get(conn);
  		if (!smp) {
  			return -ENOTCONN;
  		}
  
  		if (!smp_keys_check(conn)) {
  			return smp_send_pairing_req(conn);
  		}
  
  		/* pairing is in progress */
  		if (atomic_test_bit(smp->flags, SMP_FLAG_PAIRING)) {
  			return -EBUSY;
  		}
  
  		/* Encryption is in progress */
  		if (atomic_test_bit(smp->flags, SMP_FLAG_ENC_PENDING)) {
  			return -EBUSY;
  		}
  
  		/* LE SC LTK and legacy master LTK are stored in same place */
  		err = bt_conn_le_start_encryption(conn,
  						  conn->le.keys->ltk.rand,
  						  conn->le.keys->ltk.ediv,
  						  conn->le.keys->ltk.val,
  						  conn->le.keys->enc_size);
  		if (err) {
  			return err;
  		}
  
  		atomic_set_bit(smp->allowed_cmds, BT_SMP_CMD_SECURITY_REQUEST);
  		atomic_set_bit(smp->flags, SMP_FLAG_ENC_PENDING);
  		return 0;
  	}
  #endif /* CONFIG_BT_CENTRAL && CONFIG_BT_SMP */
  #if defined(CONFIG_BT_PERIPHERAL)
  	case BT_HCI_ROLE_SLAVE:
  		return smp_send_security_req(conn);
  #endif /* CONFIG_BT_PERIPHERAL && CONFIG_BT_SMP */
  	default:
  		return -EINVAL;
  	}
  }
  
  void bt_smp_update_keys(struct bt_conn *conn)
  {
  	struct bt_smp *smp;
  
  	smp = smp_chan_get(conn);
  	if (!smp) {
  		return;
  	}
  
  	if (!atomic_test_bit(smp->flags, SMP_FLAG_PAIRING)) {
  		return;
  	}
  
  	/*
  	 * If link was successfully encrypted cleanup old keys as from now on
  	 * only keys distributed in this pairing or LTK from LE SC will be used.
  	 */
  	if (conn->le.keys) {
  		bt_keys_clear(conn->le.keys);
  	}
  
  	conn->le.keys = bt_keys_get_addr(conn->id, &conn->le.dst);
  	if (!conn->le.keys) {
  		BT_ERR("Unable to get keys for %s",
  		       bt_addr_le_str(&conn->le.dst));
  		smp_error(smp, BT_SMP_ERR_UNSPECIFIED);
  		return;
  	}
  
  	/* mark keys as debug */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_SC_DEBUG_KEY)) {
  		conn->le.keys->flags |= BT_KEYS_DEBUG;
  	}
  
  	/*
  	 * store key type deducted from pairing method used
  	 * it is important to store it since type is used to determine
  	 * security level upon encryption
  	 */
  	switch (smp->method) {
  	case PASSKEY_DISPLAY:
  	case PASSKEY_INPUT:
  	case PASSKEY_CONFIRM:
  	case LE_SC_OOB:
  	case LEGACY_OOB:
  		conn->le.keys->flags |= BT_KEYS_AUTHENTICATED;
  		break;
  	case JUST_WORKS:
  	default:
  		/* unauthenticated key, clear it */
  		conn->le.keys->flags &= ~BT_KEYS_AUTHENTICATED;
  		break;
  	}
  
  	conn->le.keys->enc_size = get_encryption_key_size(smp);
  
  	/*
  	 * Store LTK if LE SC is used, this is safe since LE SC is mutually
  	 * exclusive with legacy pairing. Other keys are added on keys
  	 * distribution.
  	 */
  	if (atomic_test_bit(smp->flags, SMP_FLAG_SC)) {
  		conn->le.keys->flags |= BT_KEYS_SC;
  
  		if (atomic_test_bit(smp->flags, SMP_FLAG_BOND)) {
  			bt_keys_add_type(conn->le.keys, BT_KEYS_LTK_P256);
  			memcpy(conn->le.keys->ltk.val, smp->tk,
  			       sizeof(conn->le.keys->ltk.val));
  			(void)memset(conn->le.keys->ltk.rand, 0,
  				     sizeof(conn->le.keys->ltk.rand));
  			(void)memset(conn->le.keys->ltk.ediv, 0,
  				     sizeof(conn->le.keys->ltk.ediv));
  		}
  	} else {
  		conn->le.keys->flags &= ~BT_KEYS_SC;
  	}
  }
  
  static int bt_smp_accept(struct bt_conn *conn, struct bt_l2cap_chan **chan)
  {
  	int i;
  	static const struct bt_l2cap_chan_ops ops = {
  		.connected = bt_smp_connected,
  		.disconnected = bt_smp_disconnected,
  		.encrypt_change = bt_smp_encrypt_change,
  		.recv = bt_smp_recv,
  	};
  
  	BT_DBG("conn %p handle %u", conn, conn->handle);
  
  	for (i = 0; i < ARRAY_SIZE(bt_smp_pool); i++) {
  		struct bt_smp *smp = &bt_smp_pool[i];
  
  		if (smp->chan.chan.conn) {
  			continue;
  		}
  
  		smp->chan.chan.ops = &ops;
  
  		*chan = &smp->chan.chan;
  
  		return 0;
  	}
  
  	BT_ERR("No available SMP context for conn %p", conn);
  
  	return -ENOMEM;
  }
  
  BT_L2CAP_CHANNEL_DEFINE(smp_fixed_chan, BT_L2CAP_CID_SMP, bt_smp_accept, NULL);
  #if defined(CONFIG_BT_BREDR)
  BT_L2CAP_CHANNEL_DEFINE(smp_br_fixed_chan, BT_L2CAP_CID_BR_SMP,
  			bt_smp_br_accept, NULL);
  #endif /* CONFIG_BT_BREDR */
  
  int bt_smp_init(void)
  {
  	static struct bt_pub_key_cb pub_key_cb = {
  		.func           = bt_smp_pkey_ready,
  	};
  
  	sc_supported = le_sc_supported();
  	if (IS_ENABLED(CONFIG_BT_SMP_SC_PAIR_ONLY) && !sc_supported) {
  		BT_ERR("SC Pair Only Mode selected but LE SC not supported");
  		return -ENOENT;
  	}
  
  	if (IS_ENABLED(CONFIG_BT_SMP_USB_HCI_CTLR_WORKAROUND)) {
  		BT_WARN("BT_SMP_USB_HCI_CTLR_WORKAROUND is enabled, which "
  			"exposes a security vulnerability!");
  	}
  
  	BT_DBG("LE SC %s", sc_supported ? "enabled" : "disabled");
  
  	if (!IS_ENABLED(CONFIG_BT_SMP_OOB_LEGACY_PAIR_ONLY)) {
  		bt_pub_key_gen(&pub_key_cb);
  	}
  
  	return smp_self_test();
  }
  