avr-crypto-lib/noekeon/noekeon_prng.c

68 lines
1.6 KiB
C

/* noekeon_prng.c */
/*
* This file is part of the AVR-Crypto-Lib.
* Copyright (C) 2006, 2007, 2008 Daniel Otte (daniel.otte@rub.de)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* \author Daniel Otte
* \date 2008-08-24
* \license GPLv3 or later
* \brief random number generator based on noekeon running in CFB-mode
*
*/
#include "noekeon.h"
#include "memxor.h"
#include <stdint.h>
#include <string.h>
static uint8_t random_state[16];
static uint8_t random_key[16];
static uint8_t i=0;
uint8_t random8(void){
static uint8_t sr[16];
if(i==0){
noekeon_enc(random_state, random_key);
memcpy(sr, random_state, 16);
i=15;
return sr[15];
}
--i;
return sr[i];
}
void random_block(void* dest){
i=0;
noekeon_enc(random_state, random_key);
memcpy(dest, random_state, 16);
}
void srandom32(uint32_t seed){
memcpy(random_key, &seed, 4);
}
void random_seed(const void* buffer){
memcpy(random_key, buffer, 16);
}
void random_add(const void* buffer){
memxor(random_key, buffer, 16);
}