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targets/TARGET_NUVOTON/TARGET_NUC472/trng_api.c@180:b0033dcd6934, 2017-12-07 (annotated)

Committer:
AnnaBridge
Date:
Thu Dec 07 14:01:42 2017 +0000
Revision:
180:b0033dcd6934
Parent:
163:74e0ce7f98e8
Child:
181:96ed750bd169
mbed-dev library. Release version 157

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 149:156823d33999 1 /*
<> 149:156823d33999 2 * Hardware entropy collector for NUC472's RNGA
<> 149:156823d33999 3 *
<> 149:156823d33999 4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
<> 149:156823d33999 5 * SPDX-License-Identifier: Apache-2.0
<> 149:156823d33999 6 *
<> 149:156823d33999 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
<> 149:156823d33999 8 * not use this file except in compliance with the License.
<> 149:156823d33999 9 * You may obtain a copy of the License at
<> 149:156823d33999 10 *
<> 149:156823d33999 11 * http://www.apache.org/licenses/LICENSE-2.0
<> 149:156823d33999 12 *
<> 149:156823d33999 13 * Unless required by applicable law or agreed to in writing, software
<> 149:156823d33999 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
<> 149:156823d33999 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 149:156823d33999 16 * See the License for the specific language governing permissions and
<> 149:156823d33999 17 * limitations under the License.
<> 149:156823d33999 18 *
<> 149:156823d33999 19 */
<> 149:156823d33999 20
<> 149:156823d33999 21 #if DEVICE_TRNG
<> 149:156823d33999 22
<> 149:156823d33999 23 #include <stdlib.h>
<> 149:156823d33999 24 #include <string.h>
<> 149:156823d33999 25 #include "cmsis.h"
<> 149:156823d33999 26 #include "NUC472_442.h"
<> 149:156823d33999 27 #include "us_ticker_api.h"
<> 149:156823d33999 28 #include "trng_api.h"
<> 149:156823d33999 29
<> 149:156823d33999 30 /*
<> 149:156823d33999 31 * Get Random number generator.
<> 149:156823d33999 32 */
AnnaBridge 180:b0033dcd6934 33
AnnaBridge 180:b0033dcd6934 34 #define PRNG_KEY_SIZE (0x20UL)
AnnaBridge 180:b0033dcd6934 35
<> 149:156823d33999 36 static volatile int g_PRNG_done;
Anna Bridge 163:74e0ce7f98e8 37 volatile int g_AES_done;
<> 149:156823d33999 38
AnnaBridge 180:b0033dcd6934 39 /* Implementation that should never be optimized out by the compiler */
AnnaBridge 180:b0033dcd6934 40 static void trng_zeroize( void *v, size_t n ) {
AnnaBridge 180:b0033dcd6934 41 volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0;
AnnaBridge 180:b0033dcd6934 42 }
AnnaBridge 180:b0033dcd6934 43
<> 149:156823d33999 44 void CRYPTO_IRQHandler()
<> 149:156823d33999 45 {
<> 149:156823d33999 46 if (PRNG_GET_INT_FLAG()) {
<> 149:156823d33999 47 g_PRNG_done = 1;
<> 149:156823d33999 48 PRNG_CLR_INT_FLAG();
Anna Bridge 163:74e0ce7f98e8 49 } else if (AES_GET_INT_FLAG()) {
Anna Bridge 163:74e0ce7f98e8 50 g_AES_done = 1;
Anna Bridge 163:74e0ce7f98e8 51 AES_CLR_INT_FLAG();
<> 149:156823d33999 52 }
<> 149:156823d33999 53 }
<> 149:156823d33999 54
<> 149:156823d33999 55 static void trng_get(unsigned char *pConversionData)
<> 149:156823d33999 56 {
<> 149:156823d33999 57 uint32_t *p32ConversionData;
<> 149:156823d33999 58
<> 149:156823d33999 59 p32ConversionData = (uint32_t *)pConversionData;
<> 149:156823d33999 60
<> 149:156823d33999 61 PRNG_Open(PRNG_KEY_SIZE_256, 1, us_ticker_read());
<> 149:156823d33999 62 PRNG_Start();
<> 149:156823d33999 63 while (!g_PRNG_done);
<> 149:156823d33999 64
<> 149:156823d33999 65 PRNG_Read(p32ConversionData);
<> 149:156823d33999 66 }
<> 149:156823d33999 67
<> 149:156823d33999 68 void trng_init(trng_t *obj)
<> 149:156823d33999 69 {
<> 149:156823d33999 70 (void)obj;
<> 149:156823d33999 71 /* Unlock protected registers */
<> 149:156823d33999 72 SYS_UnlockReg();
<> 149:156823d33999 73 /* Enable IP clock */
<> 149:156823d33999 74 CLK_EnableModuleClock(CRPT_MODULE);
<> 149:156823d33999 75
<> 149:156823d33999 76 /* Lock protected registers */
<> 149:156823d33999 77 SYS_LockReg();
<> 149:156823d33999 78
<> 149:156823d33999 79 NVIC_EnableIRQ(CRPT_IRQn);
<> 149:156823d33999 80 PRNG_ENABLE_INT();
<> 149:156823d33999 81 }
<> 149:156823d33999 82
<> 149:156823d33999 83 void trng_free(trng_t *obj)
<> 149:156823d33999 84 {
<> 149:156823d33999 85 (void)obj;
<> 149:156823d33999 86 PRNG_DISABLE_INT();
<> 149:156823d33999 87 NVIC_DisableIRQ(CRPT_IRQn);
<> 149:156823d33999 88 }
<> 149:156823d33999 89
<> 149:156823d33999 90 int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)
<> 149:156823d33999 91 {
<> 149:156823d33999 92 (void)obj;
AnnaBridge 180:b0033dcd6934 93 unsigned char tmpBuff[PRNG_KEY_SIZE];
AnnaBridge 180:b0033dcd6934 94 size_t cur_length = 0;
AnnaBridge 180:b0033dcd6934 95
AnnaBridge 180:b0033dcd6934 96 while (length >= sizeof(tmpBuff)) {
AnnaBridge 180:b0033dcd6934 97 trng_get(output);
AnnaBridge 180:b0033dcd6934 98 output += sizeof(tmpBuff);
AnnaBridge 180:b0033dcd6934 99 cur_length += sizeof(tmpBuff);
AnnaBridge 180:b0033dcd6934 100 length -= sizeof(tmpBuff);
AnnaBridge 180:b0033dcd6934 101 }
AnnaBridge 180:b0033dcd6934 102 if (length > 0) {
<> 149:156823d33999 103 trng_get(tmpBuff);
AnnaBridge 180:b0033dcd6934 104 memcpy(output, tmpBuff, length);
AnnaBridge 180:b0033dcd6934 105 cur_length += length;
AnnaBridge 180:b0033dcd6934 106 trng_zeroize(tmpBuff, sizeof(tmpBuff));
<> 149:156823d33999 107 }
AnnaBridge 180:b0033dcd6934 108 *output_length = cur_length;
<> 149:156823d33999 109 return 0;
<> 149:156823d33999 110 }
<> 149:156823d33999 111
<> 149:156823d33999 112 #endif
<> 149:156823d33999 113