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| 1 | +/** |
| 2 | + * \file atecc608a_se.c |
| 3 | + * \brief Secure element driver implementation for ATECC508A and ATECC509A. |
| 4 | + */ |
| 5 | + |
| 6 | +/* |
| 7 | + * Copyright (C) 2019, ARM Limited, All Rights Reserved |
| 8 | + * SPDX-License-Identifier: Apache-2.0 |
| 9 | + * |
| 10 | + * Licensed under the Apache License, Version 2.0 (the "License"); you may |
| 11 | + * not use this file except in compliance with the License. |
| 12 | + * You may obtain a copy of the License at |
| 13 | + * |
| 14 | + * http://www.apache.org/licenses/LICENSE-2.0 |
| 15 | + * |
| 16 | + * Unless required by applicable law or agreed to in writing, software |
| 17 | + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| 18 | + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 19 | + * See the License for the specific language governing permissions and |
| 20 | + * limitations under the License. |
| 21 | + */ |
| 22 | +#include "atecc608a_se.h" |
| 23 | +#include "atca_helpers.h" |
| 24 | + |
| 25 | +#ifdef DEBUG_PRINT |
| 26 | +#include <stdio.h> |
| 27 | +#endif |
| 28 | + |
| 29 | +#include <stdbool.h> |
| 30 | +#include <stdint.h> |
| 31 | + |
| 32 | +/* Uncomment to print results on success */ |
| 33 | +//#define DEBUG_PRINT |
| 34 | + |
| 35 | +/** This macro checks if the result of an `expression` is equal to an |
| 36 | + * `expected` value and sets a `status` variable of type `psa_status_t` to |
| 37 | + * `PSA_SUCCESS`. If they are not equal, the `status` is set to |
| 38 | + * `psa_error instead`, and the code jumps to the `exit` label. */ |
| 39 | +#define ASSERT_STATUS(expression, expected, psa_error) \ |
| 40 | + do \ |
| 41 | + { \ |
| 42 | + ATCA_STATUS ASSERT_result = (expression); \ |
| 43 | + ATCA_STATUS ASSERT_expected = (expected); \ |
| 44 | + if ((ASSERT_result) != (ASSERT_expected)) \ |
| 45 | + { \ |
| 46 | + status = (psa_error); \ |
| 47 | + goto exit; \ |
| 48 | + } \ |
| 49 | + status = PSA_SUCCESS; \ |
| 50 | + } while(0) |
| 51 | + |
| 52 | +/** Check if an ATCA operation is successful, translate the error otherwise. */ |
| 53 | +#define ASSERT_SUCCESS(expression) ASSERT_STATUS(expression, ATCA_SUCCESS, \ |
| 54 | + atecc608a_to_psa_error(ASSERT_result)) |
| 55 | + |
| 56 | +/** Does the same as the macro above, but without the error translation and for |
| 57 | + * the PSA return code - PSA_SUCCESS.*/ |
| 58 | +#define ASSERT_SUCCESS_PSA(expression) ASSERT_STATUS(expression, PSA_SUCCESS, \ |
| 59 | + ASSERT_result) |
| 60 | + |
| 61 | +static ATCAIfaceCfg atca_iface_config = { |
| 62 | + .iface_type = ATCA_I2C_IFACE, |
| 63 | + .devtype = ATECC608A, |
| 64 | + .atcai2c.slave_address = 0xC0, |
| 65 | + .atcai2c.bus = 2, |
| 66 | + .atcai2c.baud = 400000, |
| 67 | + .wake_delay = 1500, |
| 68 | + .rx_retries = 20, |
| 69 | +}; |
| 70 | + |
| 71 | +psa_status_t atecc608a_to_psa_error(ATCA_STATUS ret) |
| 72 | +{ |
| 73 | + switch (ret) |
| 74 | + { |
| 75 | + case ATCA_SUCCESS: |
| 76 | + case ATCA_RX_NO_RESPONSE: |
| 77 | + case ATCA_WAKE_SUCCESS: |
| 78 | + return PSA_SUCCESS; |
| 79 | + case ATCA_BAD_PARAM: |
| 80 | + case ATCA_INVALID_ID: |
| 81 | + return PSA_ERROR_INVALID_ARGUMENT; |
| 82 | + case ATCA_ASSERT_FAILURE: |
| 83 | + return PSA_ERROR_TAMPERING_DETECTED; |
| 84 | + case ATCA_SMALL_BUFFER: |
| 85 | + return PSA_ERROR_BUFFER_TOO_SMALL; |
| 86 | + case ATCA_RX_CRC_ERROR: |
| 87 | + case ATCA_RX_FAIL: |
| 88 | + case ATCA_STATUS_CRC: |
| 89 | + case ATCA_RESYNC_WITH_WAKEUP: |
| 90 | + case ATCA_PARITY_ERROR: |
| 91 | + case ATCA_TX_TIMEOUT: |
| 92 | + case ATCA_RX_TIMEOUT: |
| 93 | + case ATCA_TOO_MANY_COMM_RETRIES: |
| 94 | + case ATCA_COMM_FAIL: |
| 95 | + case ATCA_TIMEOUT: |
| 96 | + case ATCA_TX_FAIL: |
| 97 | + case ATCA_NO_DEVICES: |
| 98 | + return PSA_ERROR_COMMUNICATION_FAILURE; |
| 99 | + case ATCA_UNIMPLEMENTED: |
| 100 | + return PSA_ERROR_NOT_SUPPORTED; |
| 101 | + case ATCA_ALLOC_FAILURE: |
| 102 | + return PSA_ERROR_INSUFFICIENT_MEMORY; |
| 103 | + case ATCA_BAD_OPCODE: |
| 104 | + case ATCA_CONFIG_ZONE_LOCKED: |
| 105 | + case ATCA_DATA_ZONE_LOCKED: |
| 106 | + case ATCA_NOT_LOCKED: |
| 107 | + case ATCA_WAKE_FAILED: |
| 108 | + case ATCA_STATUS_UNKNOWN: |
| 109 | + case ATCA_STATUS_ECC: |
| 110 | + case ATCA_STATUS_SELFTEST_ERROR: |
| 111 | + case ATCA_CHECKMAC_VERIFY_FAILED: |
| 112 | + case ATCA_PARSE_ERROR: |
| 113 | + case ATCA_FUNC_FAIL: |
| 114 | + case ATCA_GEN_FAIL: |
| 115 | + case ATCA_EXECUTION_ERROR: |
| 116 | + case ATCA_HEALTH_TEST_ERROR: |
| 117 | + case ATCA_INVALID_SIZE: |
| 118 | + default: |
| 119 | + return PSA_ERROR_HARDWARE_FAILURE; |
| 120 | + } |
| 121 | +} |
| 122 | + |
| 123 | +psa_status_t atecc608a_init() |
| 124 | +{ |
| 125 | + return atecc608a_to_psa_error(atcab_init(&atca_iface_config)); |
| 126 | +} |
| 127 | + |
| 128 | +psa_status_t atecc608a_deinit() |
| 129 | +{ |
| 130 | + return atecc608a_to_psa_error(atcab_release()); |
| 131 | +} |
| 132 | + |
| 133 | +static psa_status_t atecc608a_export_public_key(psa_key_slot_number_t key, |
| 134 | + uint8_t *p_data, size_t data_size, |
| 135 | + size_t *p_data_length) |
| 136 | +{ |
| 137 | + const size_t key_data_len = 65; |
| 138 | + const uint16_t slot = key; |
| 139 | + psa_status_t status = PSA_ERROR_GENERIC_ERROR; |
| 140 | + |
| 141 | + if (data_size < key_data_len) |
| 142 | + { |
| 143 | + return PSA_ERROR_BUFFER_TOO_SMALL; |
| 144 | + } |
| 145 | + |
| 146 | + ASSERT_SUCCESS_PSA(atecc608a_init()); |
| 147 | + |
| 148 | + /* atcab_get_pubkey returns concatenated x and y values, and the desired |
| 149 | + format is 0x04 + x + y. We start at &p_data[1] and add a 0x04 at p_data[0]. */ |
| 150 | + ASSERT_SUCCESS(atcab_get_pubkey(slot, &p_data[1])); |
| 151 | + |
| 152 | + p_data[0] = 4; |
| 153 | + *p_data_length = key_data_len; |
| 154 | + |
| 155 | +#ifdef DEBUG_PRINT |
| 156 | + printf("atecc608a_export_key - pubkey size %d:\n", *p_data_length); |
| 157 | + atcab_printbin_sp(p_data, *p_data_length); |
| 158 | +#endif |
| 159 | + |
| 160 | +exit: |
| 161 | + atecc608a_deinit(); |
| 162 | + return status; |
| 163 | +} |
| 164 | + |
| 165 | +static psa_status_t atecc608a_asymmetric_sign(psa_key_slot_number_t key_slot, |
| 166 | + psa_algorithm_t alg, |
| 167 | + const uint8_t *p_hash, |
| 168 | + size_t hash_length, |
| 169 | + uint8_t *p_signature, |
| 170 | + size_t signature_size, |
| 171 | + size_t *p_signature_length) |
| 172 | +{ |
| 173 | + const uint16_t key_id = key_slot; |
| 174 | + psa_status_t status = PSA_ERROR_GENERIC_ERROR; |
| 175 | + |
| 176 | + /* We can only do ECDSA on SHA-256 */ |
| 177 | + if (alg != PSA_ALG_ECDSA(PSA_ALG_SHA_256) && alg != PSA_ALG_ECDSA_ANY) |
| 178 | + { |
| 179 | + return PSA_ERROR_NOT_SUPPORTED; |
| 180 | + } |
| 181 | + |
| 182 | + if (hash_length != 32) |
| 183 | + { |
| 184 | + /* The driver only supports signing things of length 32. */ |
| 185 | + return PSA_ERROR_NOT_SUPPORTED; |
| 186 | + } |
| 187 | + |
| 188 | + if (signature_size < ATCA_SIG_SIZE) |
| 189 | + { |
| 190 | + return PSA_ERROR_BUFFER_TOO_SMALL; |
| 191 | + } |
| 192 | + |
| 193 | + ASSERT_SUCCESS_PSA(atecc608a_init()); |
| 194 | + |
| 195 | + /* Signature will be returned here. Format is R and S integers in |
| 196 | + * big-endian format. 64 bytes for P256 curve. */ |
| 197 | + ASSERT_SUCCESS(atcab_sign(key_id, p_hash, p_signature)); |
| 198 | + |
| 199 | + *p_signature_length = ATCA_SIG_SIZE; |
| 200 | + |
| 201 | +#ifdef DEBUG_PRINT |
| 202 | + printf("atecc608a_asymmetric_sign - signature size %d:\n", *p_signature_length); |
| 203 | + atcab_printbin_sp(p_signature, *p_signature_length); |
| 204 | +#endif |
| 205 | + |
| 206 | +exit: |
| 207 | + atecc608a_deinit(); |
| 208 | + return status; |
| 209 | +} |
| 210 | + |
| 211 | + |
| 212 | +#define PSA_ATECC608A_LIFETIME 0xdeadbeefU |
| 213 | + |
| 214 | +static psa_drv_se_asymmetric_t atecc608a_asymmetric = |
| 215 | +{ |
| 216 | + .p_sign = &atecc608a_asymmetric_sign, |
| 217 | + .p_verify = 0, |
| 218 | + .p_encrypt = 0, |
| 219 | + .p_decrypt = 0, |
| 220 | +}; |
| 221 | + |
| 222 | +static psa_drv_se_key_management_t atecc608a_key_management = |
| 223 | +{ |
| 224 | + .p_import = 0, |
| 225 | + .p_generate = 0, |
| 226 | + .p_destroy = 0, |
| 227 | + /* So far there is no public key export function in the API, so use this instead */ |
| 228 | + .p_export = &atecc608a_export_public_key, |
| 229 | +}; |
| 230 | + |
| 231 | +psa_drv_se_info_t atecc608a_drv_info = |
| 232 | +{ |
| 233 | + .lifetime = PSA_ATECC608A_LIFETIME, |
| 234 | + .p_key_management = &atecc608a_key_management, |
| 235 | + .p_mac = 0, |
| 236 | + .p_cipher = 0, |
| 237 | + .p_asym = &atecc608a_asymmetric, |
| 238 | + .p_aead = 0, |
| 239 | + .p_derive = 0, |
| 240 | + .slot_min = 0, |
| 241 | + .slot_max = 0, |
| 242 | +}; |
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