1 /* SPDX-License-Identifier: BSD-2-Clause */ 2 /* 3 * Copyright (c) 2019, Linaro Limited 4 */ 5 6 #ifndef __KERNEL_HUK_SUBKEY_H 7 #define __KERNEL_HUK_SUBKEY_H 8 9 #include <tee_api_types.h> 10 #include <types_ext.h> 11 #include <utee_defines.h> 12 13 /* 14 * enum huk_subkey_usage - subkey usage identifier 15 * @HUK_SUBKEY_RPMB: RPMB key 16 * @HUK_SUBKEY_SSK: Secure Storage key 17 * @HUK_SUBKEY_DIE_ID: Representing the die ID 18 * 19 * Add more identifiers as needed, be careful to not change the already 20 * assigned numbers as that will affect the derived subkey. 21 */ 22 enum huk_subkey_usage { 23 /* 24 * All IDs are explicitly assigned to make it easier to keep then 25 * constant. 26 */ 27 HUK_SUBKEY_RPMB = 0, 28 HUK_SUBKEY_SSK = 1, 29 HUK_SUBKEY_DIE_ID = 2, 30 }; 31 32 #define HUK_SUBKEY_MAX_LEN TEE_SHA256_HASH_SIZE 33 34 /* 35 * huk_subkey_derive() - Derive a subkey from the hardware unique key 36 * @usage: Intended usage of the subkey 37 * @const_data: Constant data to generate different subkeys with 38 * the same usage 39 * @const_data_len: Length of constant data 40 * @subkey: Generated subkey 41 * @subkey_len: Required size of the subkey, sizes larger than 42 * HUK_SUBKEY_MAX_LEN are not accepted. 43 * 44 * Returns a subkey derived from the hardware unique key. Given the same 45 * input the same subkey is returned each time. 46 * 47 * Return TEE_SUCCES on success or an error code on failure. 48 */ 49 TEE_Result huk_subkey_derive(enum huk_subkey_usage usage, 50 const void *const_data, size_t const_data_len, 51 uint8_t *subkey, size_t subkey_len); 52 53 54 #endif /*__KERNEL_HUK_SUBKEY_H*/ 55