mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-12-18 12:28:09 +00:00
101 lines
2.4 KiB
C
101 lines
2.4 KiB
C
/**
|
|
* Copyright (c) 2013-2014 Tomas Dzetkulic
|
|
* Copyright (c) 2013-2014 Pavol Rusnak
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining
|
|
* a copy of this software and associated documentation files (the "Software"),
|
|
* to deal in the Software without restriction, including without limitation
|
|
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
|
|
* and/or sell copies of the Software, and to permit persons to whom the
|
|
* Software is furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included
|
|
* in all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
|
|
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
|
|
* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
|
|
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
|
|
* OTHER DEALINGS IN THE SOFTWARE.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#ifdef _WIN32
|
|
#include <time.h>
|
|
#else
|
|
#include <assert.h>
|
|
#endif
|
|
|
|
#include "rand.h"
|
|
|
|
static FILE *frand = NULL;
|
|
|
|
int finalize_rand(void)
|
|
{
|
|
#ifdef _WIN32
|
|
return 0;
|
|
#else
|
|
if (!frand) return 0;
|
|
int err = fclose(frand);
|
|
frand = NULL;
|
|
return err;
|
|
#endif
|
|
}
|
|
|
|
uint32_t random32(void)
|
|
{
|
|
#ifdef _WIN32
|
|
srand((unsigned)time(NULL));
|
|
return ((rand() % 0xFF) | ((rand() % 0xFF) << 8) | ((rand() % 0xFF) << 16) | ((rand() % 0xFF) << 24));
|
|
#else
|
|
uint32_t r;
|
|
size_t len = sizeof(r);
|
|
if (!frand) {
|
|
frand = fopen("/dev/urandom", "r");
|
|
}
|
|
size_t len_read = fread(&r, 1, len, frand);
|
|
(void)len_read;
|
|
assert(len_read == len);
|
|
return r;
|
|
#endif
|
|
}
|
|
|
|
uint32_t random_uniform(uint32_t n)
|
|
{
|
|
uint32_t x, max = 0xFFFFFFFF - (0xFFFFFFFF % n);
|
|
while ((x = random32()) >= max);
|
|
return x / (max / n);
|
|
}
|
|
|
|
void random_buffer(uint8_t *buf, size_t len)
|
|
{
|
|
#ifdef _WIN32
|
|
srand((unsigned)time(NULL));
|
|
size_t i;
|
|
for (i = 0; i < len; i++) {
|
|
buf[i] = rand() % 0xFF;
|
|
}
|
|
#else
|
|
if (!frand) {
|
|
frand = fopen("/dev/urandom", "r");
|
|
}
|
|
size_t len_read = fread(buf, 1, len, frand);
|
|
(void)len_read;
|
|
assert(len_read == len);
|
|
#endif
|
|
}
|
|
|
|
void random_permute(char *str, size_t len)
|
|
{
|
|
int i, j;
|
|
char t;
|
|
for (i = len - 1; i >= 1; i--) {
|
|
j = random_uniform(i + 1);
|
|
t = str[j];
|
|
str[j] = str[i];
|
|
str[i] = t;
|
|
}
|
|
}
|