stm32u5xx_crypto_trng.c
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1 /**
2  * @file stm32u5xx_crypto_trng.c
3  * @brief STM32U5 true random number generator
4  *
5  * @section License
6  *
7  * SPDX-License-Identifier: GPL-2.0-or-later
8  *
9  * Copyright (C) 2010-2024 Oryx Embedded SARL. All rights reserved.
10  *
11  * This file is part of CycloneCRYPTO Open.
12  *
13  * This program is free software; you can redistribute it and/or
14  * modify it under the terms of the GNU General Public License
15  * as published by the Free Software Foundation; either version 2
16  * of the License, or (at your option) any later version.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21  * GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software Foundation,
25  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
26  *
27  * @author Oryx Embedded SARL (www.oryx-embedded.com)
28  * @version 2.4.0
29  **/
30 
31 //Switch to the appropriate trace level
32 #define TRACE_LEVEL CRYPTO_TRACE_LEVEL
33 
34 //Dependencies
35 #include "stm32u5xx.h"
36 #include "stm32u5xx_hal.h"
37 #include "core/crypto.h"
40 #include "debug.h"
41 
42 //Check crypto library configuration
43 #if (STM32U5XX_CRYPTO_TRNG_SUPPORT == ENABLED)
44 
45 //Global variable
46 static RNG_HandleTypeDef RNG_Handle;
47 
48 
49 /**
50  * @brief TRNG module initialization
51  * @return Error code
52  **/
53 
55 {
56  HAL_StatusTypeDef status;
57 
58  //Enable RNG peripheral clock
59  __HAL_RCC_RNG_CLK_ENABLE();
60 
61  //Set instance
62  RNG_Handle.Instance = RNG;
63 
64  //Reset RNG module
65  status = HAL_RNG_DeInit(&RNG_Handle);
66 
67  //Check status code
68  if(status == HAL_OK)
69  {
70  //Initialize RNG module
71  status = HAL_RNG_Init(&RNG_Handle);
72  }
73 
74  //Return status code
75  return (status == HAL_OK) ? NO_ERROR : ERROR_FAILURE;
76 }
77 
78 
79 /**
80  * @brief Get random data from the TRNG module
81  * @param[out] data Buffer where to store random data
82  * @param[in] length Number of random bytes to generate
83  **/
84 
86 {
87  size_t i;
88  uint32_t value;
89  HAL_StatusTypeDef status;
90 
91  //Initialize status code
92  status = HAL_OK;
93 
94  //Acquire exclusive access to the RNG module
96 
97  //Generate random data
98  for(i = 0; i < length; i++)
99  {
100  //Generate a new 32-bit random value when necessary
101  if((i % 4) == 0)
102  {
103  //Get 32-bit random value
104  status = HAL_RNG_GenerateRandomNumber(&RNG_Handle, &value);
105  //Check status code
106  if(status != HAL_OK)
107  {
108  break;
109  }
110  }
111 
112  //Copy random byte
113  data[i] = value & 0xFF;
114  //Shift the 32-bit random value
115  value >>= 8;
116  }
117 
118  //Release exclusive access to the RNG module
120 
121  //Return status code
122  return (status == HAL_OK) ? NO_ERROR : ERROR_FAILURE;
123 }
124 
125 #endif
General definitions for cryptographic algorithms.
Debugging facilities.
error_t
Error codes.
Definition: error.h:43
@ NO_ERROR
Success.
Definition: error.h:44
@ ERROR_FAILURE
Generic error code.
Definition: error.h:45
uint8_t data[]
Definition: ethernet.h:222
void osAcquireMutex(OsMutex *mutex)
Acquire ownership of the specified mutex object.
void osReleaseMutex(OsMutex *mutex)
Release ownership of the specified mutex object.
OsMutex stm32u5xxCryptoMutex
STM32U5 hardware cryptographic accelerator.
error_t trngGetRandomData(uint8_t *data, size_t length)
Get random data from the TRNG module.
error_t trngInit(void)
TRNG module initialization.
STM32U5 true random number generator.
uint8_t length
Definition: tcp.h:368
uint8_t value[]
Definition: tcp.h:369