ZeroTierOne/attic/historic/anode/libanode/secure_random.c
2017-05-04 10:42:22 -07:00

89 lines
2.9 KiB
C

/* libanode: the Anode C reference implementation
* Copyright (C) 2009-2010 Adam Ierymenko <adam.ierymenko@gmail.com>
*
* 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/>. */
#include <stdlib.h>
#include <stdio.h>
#include "impl/aes.h"
#include "impl/misc.h"
#include "anode.h"
#ifdef WINDOWS
#include <windows.h>
#include <wincrypt.h>
#endif
struct AnodeSecureRandomImpl
{
AnodeAesExpandedKey key;
unsigned char state[ANODE_AES_BLOCK_SIZE];
unsigned char block[ANODE_AES_BLOCK_SIZE];
unsigned int ptr;
};
AnodeSecureRandom *AnodeSecureRandom_new()
{
unsigned char keybuf[ANODE_AES_KEY_SIZE + ANODE_AES_BLOCK_SIZE + ANODE_AES_BLOCK_SIZE];
unsigned int i;
struct AnodeSecureRandomImpl *srng;
#ifdef WINDOWS
HCRYPTPROV hProv;
if (CryptAcquireContext(&hProv,NULL,NULL,PROV_RSA_FULL,CRYPT_VERIFYCONTEXT|CRYPT_SILENT)) {
CryptGenRandom(hProv,sizeof(keybuf),keybuf);
CryptReleaseContext(hProv,0);
}
#else
FILE *urandf = fopen("/dev/urandom","rb");
if (urandf) {
fread((void *)keybuf,sizeof(keybuf),1,urandf);
fclose(urandf);
}
#endif
for(i=0;i<sizeof(keybuf);++i)
keybuf[i] ^= (unsigned char)(Anode_rand() >> 5);
srng = malloc(sizeof(struct AnodeSecureRandomImpl));
Anode_aes256_expand_key(keybuf,&srng->key);
for(i=0;i<ANODE_AES_BLOCK_SIZE;++i)
srng->state[i] = keybuf[ANODE_AES_KEY_SIZE + i];
for(i=0;i<ANODE_AES_BLOCK_SIZE;++i)
srng->block[i] = keybuf[ANODE_AES_KEY_SIZE + ANODE_AES_KEY_SIZE + i];
srng->ptr = ANODE_AES_BLOCK_SIZE;
return (AnodeSecureRandom *)srng;
}
void AnodeSecureRandom_gen_bytes(AnodeSecureRandom *srng,void *buf,long count)
{
long i,j;
for(i=0;i<count;++i) {
if (((struct AnodeSecureRandomImpl *)srng)->ptr == ANODE_AES_BLOCK_SIZE) {
Anode_aes256_encrypt(&((struct AnodeSecureRandomImpl *)srng)->key,((struct AnodeSecureRandomImpl *)srng)->state,((struct AnodeSecureRandomImpl *)srng)->state);
for(j=0;j<ANODE_AES_KEY_SIZE;++j)
((struct AnodeSecureRandomImpl *)srng)->block[j] ^= ((struct AnodeSecureRandomImpl *)srng)->state[j];
((struct AnodeSecureRandomImpl *)srng)->ptr = 0;
}
((unsigned char *)buf)[i] = ((struct AnodeSecureRandomImpl *)srng)->block[((struct AnodeSecureRandomImpl *)srng)->ptr++];
}
}
void AnodeSecureRandom_delete(AnodeSecureRandom *srng)
{
free(srng);
}