1 /* 2 * Copyright (c) 2019 Bose Corporation 3 * Copyright (c) 2021-2022 Nordic Semiconductor ASA 4 * 5 * SPDX-License-Identifier: Apache-2.0 6 */ 7 8 #include <stddef.h> 9 #include <zephyr/types.h> 10 11 #include <zephyr/bluetooth/audio/csip.h> 12 13 #define BT_CSIP_CRYPTO_KEY_SIZE 16 14 #define BT_CSIP_CRYPTO_SALT_SIZE 16 15 #define BT_CSIP_CRYPTO_PRAND_SIZE 3 16 #define BT_CSIP_CRYPTO_HASH_SIZE 3 17 18 /** 19 * @brief Private Set Unique identifier hash function sih. 20 * 21 * The RSI hash function sih is used to generate a hash value that is 22 * used in RSIs - Used by the Coordinated Set Identification service and 23 * profile. 24 * 25 * @param sirk 16 byte LS byte first SIRK 26 * @param r 3 byte LS byte first random value 27 * @param out 3 byte LS byte first output buffer 28 * @return int 0 on success, any other value indicates a failure. 29 */ 30 int bt_csip_sih(const uint8_t sirk[BT_CSIP_SET_SIRK_SIZE], 31 uint8_t r[BT_CSIP_CRYPTO_PRAND_SIZE], 32 uint8_t out[BT_CSIP_CRYPTO_HASH_SIZE]); 33 34 /** 35 * @brief SIRK encryption function sef 36 * 37 * The SIRK encryption function sef is used by the server to encrypt the SIRK 38 * with a key K. The value of K depends on the transport on which the pairing 39 * between the client and the server was performed. 40 * 41 * If the pairing was performed on BR/EDR, K is equal to the Link Key shared by 42 * the server and the client. 43 * K = Link Key. 44 * 45 * If the pairing was performed on LE, the 64 LSBs of K correspond to the 64 46 * LSBs of the IRK that the server sent to the client during the Phase 3 47 * (Transport Specific Key Distribution) of the pairing procedure (see Volume 3, 48 * Part H, Section 2.1 in [2]), and the 64 MSBs of K correspond to the 64 MSBs 49 * of the LTK shared by the server and client. That is, 50 * K = LTK_64-127 || IRK_0-63 51 * 52 * @param k 16-byte key. 53 * @param sirk The unencrypted SIRK. 54 * @param out_sirk The encrypted SIRK. 55 * @return int 0 on success, any other value indicates a failure. 56 */ 57 int bt_csip_sef(const uint8_t k[BT_CSIP_CRYPTO_KEY_SIZE], 58 const uint8_t sirk[BT_CSIP_SET_SIRK_SIZE], 59 uint8_t out_sirk[BT_CSIP_SET_SIRK_SIZE]); 60 61 /** 62 * @brief SIRK decryption function sdf 63 * 64 * The SIRK decryption function sdf is used by the client to decrypt the SIRK 65 * with a key K. The value of K depends on the transport on which the pairing 66 * between the client and the server was performed. 67 * 68 * If the pairing was performed on BR/EDR, K is equal to the Link Key shared by 69 * the server and the client. 70 * K = Link Key. 71 * 72 * If the pairing was performed on LE, the 64 LSBs of K correspond to the 64 73 * LSBs of the IRK that the server sent to the client during the Phase 3 74 * (Transport Specific Key Distribution) of the pairing procedure (see Volume 3, 75 * Part H, Section 2.1 in [2]), and the 64 MSBs of K correspond to the 64 MSBs 76 * of the LTK shared by the server and client. That is, 77 * K = LTK_64-127 || IRK_0-63 78 * 79 * @param k 16-byte key. 80 * @param sirk The encrypted SIRK. 81 * @param out_sirk The decrypted SIRK. 82 * @return int 0 on success, any other value indicates a failure. 83 */ 84 int bt_csip_sdf(const uint8_t k[BT_CSIP_CRYPTO_KEY_SIZE], 85 const uint8_t enc_sirk[BT_CSIP_SET_SIRK_SIZE], 86 uint8_t out_sirk[BT_CSIP_SET_SIRK_SIZE]); 87
