mbed official / mbed-dev

mbed library sources. Supersedes mbed-src.

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

targets/TARGET_NUVOTON/TARGET_M2351/trng_api.c@189:f392fc9709a3, 2019-02-20 (annotated)

Committer:
AnnaBridge
Date:
Wed Feb 20 22:31:08 2019 +0000
Revision:
189:f392fc9709a3
Parent:
187:0387e8f68319 
mbed library release version 165

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AnnaBridge 187:0387e8f68319 1 /* mbed Microcontroller Library
AnnaBridge 187:0387e8f68319 2 * Copyright (c) 2017-2018 Nuvoton
AnnaBridge 187:0387e8f68319 3 *
AnnaBridge 187:0387e8f68319 4 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 187:0387e8f68319 5 * you may not use this file except in compliance with the License.
AnnaBridge 187:0387e8f68319 6 * You may obtain a copy of the License at
AnnaBridge 187:0387e8f68319 7 *
AnnaBridge 187:0387e8f68319 8 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 187:0387e8f68319 9 *
AnnaBridge 187:0387e8f68319 10 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 187:0387e8f68319 11 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 187:0387e8f68319 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 187:0387e8f68319 13 * See the License for the specific language governing permissions and
AnnaBridge 187:0387e8f68319 14 * limitations under the License.
AnnaBridge 187:0387e8f68319 15 */
AnnaBridge 187:0387e8f68319 16
AnnaBridge 187:0387e8f68319 17 #if DEVICE_TRNG
AnnaBridge 187:0387e8f68319 18
AnnaBridge 187:0387e8f68319 19 #include <stdlib.h>
AnnaBridge 187:0387e8f68319 20 #include <string.h>
AnnaBridge 187:0387e8f68319 21 #include "cmsis.h"
AnnaBridge 187:0387e8f68319 22 #include "us_ticker_api.h"
AnnaBridge 187:0387e8f68319 23 #include "trng_api.h"
AnnaBridge 187:0387e8f68319 24 #include "crypto-misc.h"
AnnaBridge 187:0387e8f68319 25
AnnaBridge 187:0387e8f68319 26
AnnaBridge 187:0387e8f68319 27 /*
AnnaBridge 187:0387e8f68319 28 * Get Random number generator.
AnnaBridge 187:0387e8f68319 29 */
AnnaBridge 187:0387e8f68319 30
AnnaBridge 187:0387e8f68319 31 #define PRNG_KEY_SIZE (0x20UL)
AnnaBridge 187:0387e8f68319 32
AnnaBridge 187:0387e8f68319 33 static void trng_get(unsigned char *pConversionData)
AnnaBridge 187:0387e8f68319 34 {
AnnaBridge 187:0387e8f68319 35 uint32_t *p32ConversionData;
AnnaBridge 187:0387e8f68319 36
AnnaBridge 187:0387e8f68319 37 p32ConversionData = (uint32_t *)pConversionData;
AnnaBridge 187:0387e8f68319 38
AnnaBridge 187:0387e8f68319 39 PRNG_Open(CRYPTO_MODBASE(), PRNG_KEY_SIZE_256, 1, us_ticker_read());
AnnaBridge 187:0387e8f68319 40 crypto_prng_prestart();
AnnaBridge 187:0387e8f68319 41 PRNG_Start(CRYPTO_MODBASE());
AnnaBridge 187:0387e8f68319 42 crypto_prng_wait();
AnnaBridge 187:0387e8f68319 43
AnnaBridge 187:0387e8f68319 44 PRNG_Read(CRYPTO_MODBASE(), p32ConversionData);
AnnaBridge 187:0387e8f68319 45 }
AnnaBridge 187:0387e8f68319 46
AnnaBridge 187:0387e8f68319 47 void trng_init(trng_t *obj)
AnnaBridge 187:0387e8f68319 48 {
AnnaBridge 187:0387e8f68319 49 (void)obj;
AnnaBridge 187:0387e8f68319 50
AnnaBridge 187:0387e8f68319 51 /* Init crypto module */
AnnaBridge 187:0387e8f68319 52 crypto_init();
AnnaBridge 187:0387e8f68319 53
AnnaBridge 187:0387e8f68319 54 PRNG_ENABLE_INT(CRYPTO_MODBASE());
AnnaBridge 187:0387e8f68319 55 }
AnnaBridge 187:0387e8f68319 56
AnnaBridge 187:0387e8f68319 57 void trng_free(trng_t *obj)
AnnaBridge 187:0387e8f68319 58 {
AnnaBridge 187:0387e8f68319 59 (void)obj;
AnnaBridge 187:0387e8f68319 60
AnnaBridge 187:0387e8f68319 61 PRNG_DISABLE_INT(CRYPTO_MODBASE());
AnnaBridge 187:0387e8f68319 62
AnnaBridge 187:0387e8f68319 63 /* Uninit crypto module */
AnnaBridge 187:0387e8f68319 64 crypto_uninit();
AnnaBridge 187:0387e8f68319 65 }
AnnaBridge 187:0387e8f68319 66
AnnaBridge 187:0387e8f68319 67 int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)
AnnaBridge 187:0387e8f68319 68 {
AnnaBridge 187:0387e8f68319 69 (void)obj;
AnnaBridge 187:0387e8f68319 70 unsigned char tmpBuff[PRNG_KEY_SIZE];
AnnaBridge 187:0387e8f68319 71 size_t cur_length = 0;
AnnaBridge 187:0387e8f68319 72
AnnaBridge 187:0387e8f68319 73 while (length >= sizeof(tmpBuff)) {
AnnaBridge 187:0387e8f68319 74 trng_get(output);
AnnaBridge 187:0387e8f68319 75 output += sizeof(tmpBuff);
AnnaBridge 187:0387e8f68319 76 cur_length += sizeof(tmpBuff);
AnnaBridge 187:0387e8f68319 77 length -= sizeof(tmpBuff);
AnnaBridge 187:0387e8f68319 78 }
AnnaBridge 187:0387e8f68319 79 if (length > 0) {
AnnaBridge 187:0387e8f68319 80 trng_get(tmpBuff);
AnnaBridge 187:0387e8f68319 81 memcpy(output, tmpBuff, length);
AnnaBridge 187:0387e8f68319 82 cur_length += length;
AnnaBridge 187:0387e8f68319 83 crypto_zeroize(tmpBuff, sizeof(tmpBuff));
AnnaBridge 187:0387e8f68319 84 }
AnnaBridge 187:0387e8f68319 85 *output_length = cur_length;
AnnaBridge 187:0387e8f68319 86 return 0;
AnnaBridge 187:0387e8f68319 87 }
AnnaBridge 187:0387e8f68319 88
AnnaBridge 187:0387e8f68319 89 #endif