mbed official / mbed-dev

mbed library sources. Supersedes mbed-src.

Dependents:   Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more

targets/TARGET_Cypress/TARGET_PSOC6/trng_api.c@189:f392fc9709a3, 2019-02-20 (annotated)

Committer:
AnnaBridge
Date:
Wed Feb 20 22:31:08 2019 +0000
Revision:
189:f392fc9709a3
mbed library release version 165

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AnnaBridge 189:f392fc9709a3 1 /* mbed Microcontroller Library
AnnaBridge 189:f392fc9709a3 2 * Copyright (c) 2019 Cypress Semiconductor Corporation
AnnaBridge 189:f392fc9709a3 3 * SPDX-License-Identifier: Apache-2.0
AnnaBridge 189:f392fc9709a3 4 *
AnnaBridge 189:f392fc9709a3 5 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 189:f392fc9709a3 6 * you may not use this file except in compliance with the License.
AnnaBridge 189:f392fc9709a3 7 * You may obtain a copy of the License at
AnnaBridge 189:f392fc9709a3 8 *
AnnaBridge 189:f392fc9709a3 9 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 189:f392fc9709a3 10 *
AnnaBridge 189:f392fc9709a3 11 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 189:f392fc9709a3 12 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 189:f392fc9709a3 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 189:f392fc9709a3 14 * See the License for the specific language governing permissions and
AnnaBridge 189:f392fc9709a3 15 * limitations under the License.
AnnaBridge 189:f392fc9709a3 16 */
AnnaBridge 189:f392fc9709a3 17
AnnaBridge 189:f392fc9709a3 18 /* Hardware entropy collector for the PSoC6A families */
AnnaBridge 189:f392fc9709a3 19
AnnaBridge 189:f392fc9709a3 20 #if DEVICE_TRNG
AnnaBridge 189:f392fc9709a3 21
AnnaBridge 189:f392fc9709a3 22 #include "trng_api.h"
AnnaBridge 189:f392fc9709a3 23 #include "psoc6_utils.h"
AnnaBridge 189:f392fc9709a3 24 #include "cy_crypto_core_trng.h"
AnnaBridge 189:f392fc9709a3 25
AnnaBridge 189:f392fc9709a3 26 /* Initialization polynomial values fro True Random Generator */
AnnaBridge 189:f392fc9709a3 27 #define GARO31_INITSTATE (0x04c11db7u)
AnnaBridge 189:f392fc9709a3 28 #define FIRO31_INITSTATE (0x04c11db7u)
AnnaBridge 189:f392fc9709a3 29
AnnaBridge 189:f392fc9709a3 30 #define MAX_TRNG_BIT_SIZE (32UL)
AnnaBridge 189:f392fc9709a3 31
AnnaBridge 189:f392fc9709a3 32 void trng_init(trng_t *obj)
AnnaBridge 189:f392fc9709a3 33 {
AnnaBridge 189:f392fc9709a3 34 (void)obj;
AnnaBridge 189:f392fc9709a3 35
AnnaBridge 189:f392fc9709a3 36 cy_reserve_crypto(CY_CRYPTO_TRNG_HW);
AnnaBridge 189:f392fc9709a3 37 }
AnnaBridge 189:f392fc9709a3 38
AnnaBridge 189:f392fc9709a3 39 void trng_free(trng_t *obj)
AnnaBridge 189:f392fc9709a3 40 {
AnnaBridge 189:f392fc9709a3 41 /* Deinitialization is not needed for the driver */
AnnaBridge 189:f392fc9709a3 42 (void)obj;
AnnaBridge 189:f392fc9709a3 43
AnnaBridge 189:f392fc9709a3 44 cy_free_crypto(CY_CRYPTO_TRNG_HW);
AnnaBridge 189:f392fc9709a3 45 }
AnnaBridge 189:f392fc9709a3 46
AnnaBridge 189:f392fc9709a3 47 int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)
AnnaBridge 189:f392fc9709a3 48 {
AnnaBridge 189:f392fc9709a3 49 int ret = 0;
AnnaBridge 189:f392fc9709a3 50 *output_length = 0;
AnnaBridge 189:f392fc9709a3 51
AnnaBridge 189:f392fc9709a3 52 /* temporary random data buffer */
AnnaBridge 189:f392fc9709a3 53 uint32_t random;
AnnaBridge 189:f392fc9709a3 54
AnnaBridge 189:f392fc9709a3 55 (void)obj;
AnnaBridge 189:f392fc9709a3 56
AnnaBridge 189:f392fc9709a3 57 /* Get Random byte */
AnnaBridge 189:f392fc9709a3 58 while ((*output_length < length) && (ret == 0)) {
AnnaBridge 189:f392fc9709a3 59 if (Cy_Crypto_Core_Trng(CRYPTO, GARO31_INITSTATE, FIRO31_INITSTATE, MAX_TRNG_BIT_SIZE, &random) != CY_CRYPTO_SUCCESS) {
AnnaBridge 189:f392fc9709a3 60 ret = -1;
AnnaBridge 189:f392fc9709a3 61 } else {
AnnaBridge 189:f392fc9709a3 62 for (uint8_t i = 0; (i < 4) && (*output_length < length) ; i++) {
AnnaBridge 189:f392fc9709a3 63 *output++ = ((uint8_t *)&random)[i];
AnnaBridge 189:f392fc9709a3 64 *output_length += 1;
AnnaBridge 189:f392fc9709a3 65 }
AnnaBridge 189:f392fc9709a3 66 }
AnnaBridge 189:f392fc9709a3 67 }
AnnaBridge 189:f392fc9709a3 68 random = 0uL;
AnnaBridge 189:f392fc9709a3 69
AnnaBridge 189:f392fc9709a3 70 return (ret);
AnnaBridge 189:f392fc9709a3 71 }
AnnaBridge 189:f392fc9709a3 72
AnnaBridge 189:f392fc9709a3 73 #endif