esp32_crypto_trng.c
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1 /**
2  * @file esp32_crypto_trng.c
3  * @brief ESP32 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 "esp_random.h"
36 #include "esp_private/periph_ctrl.h"
37 #include "core/crypto.h"
40 #include "debug.h"
41 
42 //Check crypto library configuration
43 #if (ESP32_CRYPTO_TRNG_SUPPORT == ENABLED)
44 
45 
46 /**
47  * @brief RNG module initialization
48  **/
49 
50 void esp32RngInit(void)
51 {
52  //Enable RNG module
53  periph_module_enable(PERIPH_RNG_MODULE);
54 }
55 
56 
57 /**
58  * @brief Get random data from the TRNG module
59  * @param[out] data Buffer where to store random data
60  * @param[in] length Number of random bytes to generate
61  **/
62 
64 {
65  size_t i;
66  uint32_t value;
67 
68  //Initialize variable
69  value = 0;
70 
71  //Acquire exclusive access to the RNG module
73 
74  //Generate random data
75  for(i = 0; i < length; i++)
76  {
77  //Generate a new 32-bit random value when necessary
78  if((i % 4) == 0)
79  {
80  //Get the 32-bit random value
81  value = esp_random();
82  }
83 
84  //Copy random byte
85  data[i] = value & 0xFF;
86  //Shift the 32-bit random value
87  value >>= 8;
88  }
89 
90  //Release exclusive access to the RNG module
92 
93  //Successful processing
94  return NO_ERROR;
95 }
96 
97 #endif
General definitions for cryptographic algorithms.
Debugging facilities.
error_t
Error codes.
Definition: error.h:43
@ NO_ERROR
Success.
Definition: error.h:44
OsMutex esp32CryptoMutex
Definition: esp32_crypto.c:45
ESP32 hardware cryptographic accelerator.
error_t trngGetRandomData(uint8_t *data, size_t length)
Get random data from the TRNG module.
void esp32RngInit(void)
RNG module initialization.
ESP32 true random number generator.
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.
uint8_t length
Definition: tcp.h:368
uint8_t value[]
Definition: tcp.h:369