same54_crypto_trng.c
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1 /**
2  * @file same54_crypto_trng.c
3  * @brief SAME54 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 "sam.h"
36 #include "core/crypto.h"
39 #include "debug.h"
40 
41 //Check crypto library configuration
42 #if (SAME54_CRYPTO_TRNG_SUPPORT == ENABLED)
43 
44 
45 /**
46  * @brief TRNG module initialization
47  * @return Error code
48  **/
49 
51 {
52  //Enable TRNG peripheral clock
53  MCLK_REGS->MCLK_APBCMASK |= MCLK_APBCMASK_TRNG_Msk;
54  //Enable TRNG
55  TRNG_REGS->TRNG_CTRLA |= TRNG_CTRLA_ENABLE_Msk;
56 
57  //Successful initialization
58  return NO_ERROR;
59 }
60 
61 
62 /**
63  * @brief Get random data from the TRNG module
64  * @param[out] data Buffer where to store random data
65  * @param[in] length Number of random bytes to generate
66  **/
67 
69 {
70  size_t i;
71  uint32_t value;
72 
73  //Initialize variable
74  value = 0;
75 
76  //Acquire exclusive access to the TRNG module
78 
79  //Generate random data
80  for(i = 0; i < length; i++)
81  {
82  //Generate a new 32-bit random value when necessary
83  if((i % 4) == 0)
84  {
85  //Wait for the TRNG to contain a valid data
86  while((TRNG_REGS->TRNG_INTFLAG & TRNG_INTFLAG_DATARDY_Msk) == 0)
87  {
88  }
89 
90  //Get the 32-bit random value
91  value = TRNG_REGS->TRNG_DATA;
92  }
93 
94  //Copy random byte
95  data[i] = value & 0xFF;
96  //Shift the 32-bit random value
97  value >>= 8;
98  }
99 
100  //Release exclusive access to the TRNG module
102 
103  //Successful processing
104  return NO_ERROR;
105 }
106 
107 #endif
General definitions for cryptographic algorithms.
Debugging facilities.
error_t
Error codes.
Definition: error.h:43
@ NO_ERROR
Success.
Definition: error.h:44
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 same54CryptoMutex
Definition: same54_crypto.c:45
SAME54 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.
SAME54 true random number generator.
uint8_t length
Definition: tcp.h:368
uint8_t value[]
Definition: tcp.h:369