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trezor-firmware/rand.c
2015-01-23 06:05:38 -08:00

58 lines
1.6 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>
#include <assert.h>
#include "rand.h"
static FILE *f;
void init_rand(void)
{
f = fopen("/dev/urandom", "r");
}
int finalize_rand(void)
{
int err = fclose(f);
f = NULL;
return err;
}
uint32_t random32(void)
{
uint32_t r;
size_t len = sizeof(r);
size_t len_read = fread(&r, 1, len, f);
assert(len_read == len);
return r;
}
void random_buffer(uint8_t *buf, size_t len)
{
size_t len_read = fread(buf, 1, len, f);
assert(len_read == len);
}