103 lines
2.0 KiB
C
103 lines
2.0 KiB
C
/**
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* @file rpa.c
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* Resolvable Private Address Generation and Resolution
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*/
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/*
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* Copyright (c) 2017 Nordic Semiconductor ASA
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* Copyright (c) 2015-2016 Intel Corporation
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <zephyr.h>
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#include <stddef.h>
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#include <errno.h>
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#include <string.h>
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#include <atomic.h>
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#include <misc/util.h>
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#include <misc/byteorder.h>
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#include <misc/stack.h>
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#include <tinycrypt/constants.h>
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#include <tinycrypt/aes.h>
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#include <tinycrypt/utils.h>
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#include <tinycrypt/cmac_mode.h>
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#define BT_DBG_ENABLED IS_ENABLED(CONFIG_BT_DEBUG_RPA)
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#define LOG_MODULE_NAME bt_rpa
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#include "common/log.h"
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static int ah(const u8_t irk[16], const u8_t r[3], u8_t out[3])
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{
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u8_t res[16];
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int err;
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BT_DBG("irk %s, r %s", bt_hex(irk, 16), bt_hex(r, 3));
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/* r' = padding || r */
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memcpy(res, r, 3);
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(void)memset(res + 3, 0, 13);
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err = bt_encrypt_le(irk, res, res);
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if (err) {
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return err;
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}
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/* The output of the random address function ah is:
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* ah(h, r) = e(k, r') mod 2^24
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* The output of the security function e is then truncated to 24 bits
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* by taking the least significant 24 bits of the output of e as the
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* result of ah.
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*/
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memcpy(out, res, 3);
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return 0;
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}
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#if defined(CONFIG_BT_SMP) || defined(CONFIG_BT_CTLR_PRIVACY)
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bool bt_rpa_irk_matches(const u8_t irk[16], const bt_addr_t *addr)
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{
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u8_t hash[3];
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int err;
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BT_DBG("IRK %s bdaddr %s", bt_hex(irk, 16), bt_addr_str(addr));
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err = ah(irk, addr->val + 3, hash);
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if (err) {
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return false;
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}
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return !memcmp(addr->val, hash, 3);
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}
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#endif
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#if defined(CONFIG_BT_PRIVACY) || defined(CONFIG_BT_CTLR_PRIVACY)
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int bt_rpa_create(const u8_t irk[16], bt_addr_t *rpa)
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{
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int err;
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err = bt_rand(rpa->val + 3, 3);
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if (err) {
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return err;
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}
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BT_ADDR_SET_RPA(rpa);
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err = ah(irk, rpa->val + 3, rpa->val);
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if (err) {
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return err;
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}
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BT_DBG("Created RPA %s", bt_addr_str((bt_addr_t *)rpa->val));
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return 0;
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}
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#else
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int bt_rpa_create(const u8_t irk[16], bt_addr_t *rpa)
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{
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return -ENOTSUP;
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}
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#endif /* CONFIG_BT_PRIVACY */
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