mirror of https://github.com/ARMmbed/mbed-os.git
93 lines
2.1 KiB
C
93 lines
2.1 KiB
C
/*
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* Hardware entropy collector for NUC472's RNGA
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*
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* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed under the Apache License, Version 2.0 (the "License"); you may
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* not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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*/
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#if DEVICE_TRNG
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#include <stdlib.h>
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#include <string.h>
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#include "cmsis.h"
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#include "us_ticker_api.h"
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#include "trng_api.h"
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#include "crypto-misc.h"
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/*
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* Get Random number generator.
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*/
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#define PRNG_KEY_SIZE (0x20UL)
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static void trng_get(unsigned char *pConversionData)
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{
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uint32_t *p32ConversionData;
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p32ConversionData = (uint32_t *)pConversionData;
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PRNG_Open(PRNG_KEY_SIZE_256, 1, us_ticker_read());
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crypto_prng_prestart();
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PRNG_Start();
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crypto_prng_wait();
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PRNG_Read(p32ConversionData);
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}
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void trng_init(trng_t *obj)
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{
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(void)obj;
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/* Init crypto module */
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crypto_init();
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PRNG_ENABLE_INT();
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}
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void trng_free(trng_t *obj)
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{
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(void)obj;
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PRNG_DISABLE_INT();
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/* Uninit crypto module */
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crypto_uninit();
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}
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int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)
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{
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(void)obj;
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unsigned char tmpBuff[PRNG_KEY_SIZE];
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size_t cur_length = 0;
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while (length >= sizeof(tmpBuff)) {
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trng_get(output);
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output += sizeof(tmpBuff);
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cur_length += sizeof(tmpBuff);
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length -= sizeof(tmpBuff);
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}
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if (length > 0) {
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trng_get(tmpBuff);
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memcpy(output, tmpBuff, length);
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cur_length += length;
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crypto_zeroize(tmpBuff, sizeof(tmpBuff));
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}
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*output_length = cur_length;
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return 0;
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}
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#endif
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