mirror of
https://git.wownero.com/wownero/wownero.git
synced 2024-08-15 01:03:23 +00:00
232 lines
5.1 KiB
C
232 lines
5.1 KiB
C
/* $OpenBSD: arc4random.c,v 1.41 2014/07/12 13:24:54 deraadt Exp $ */
|
|
|
|
/*
|
|
* Copyright (c) 1996, David Mazieres <dm@uun.org>
|
|
* Copyright (c) 2008, Damien Miller <djm@openbsd.org>
|
|
* Copyright (c) 2013, Markus Friedl <markus@openbsd.org>
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
#include "config.h"
|
|
|
|
/*
|
|
* ChaCha based random number generator for OpenBSD.
|
|
*/
|
|
|
|
#include <fcntl.h>
|
|
#include <limits.h>
|
|
#include <signal.h>
|
|
#include <stdint.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include <sys/types.h>
|
|
#include <sys/param.h>
|
|
#include <sys/time.h>
|
|
#ifndef UB_ON_WINDOWS
|
|
#include <sys/mman.h>
|
|
#endif
|
|
|
|
#define KEYSTREAM_ONLY
|
|
#include "chacha_private.h"
|
|
|
|
#define arc4_min(a, b) ((a) < (b) ? (a) : (b))
|
|
#ifdef __GNUC__
|
|
#define inline __inline
|
|
#else /* !__GNUC__ */
|
|
#define inline
|
|
#endif /* !__GNUC__ */
|
|
|
|
#define KEYSZ 32
|
|
#define IVSZ 8
|
|
#define BLOCKSZ 64
|
|
#define RSBUFSZ (16*BLOCKSZ)
|
|
|
|
/* Marked MAP_INHERIT_ZERO, so zero'd out in fork children. */
|
|
static struct {
|
|
size_t rs_have; /* valid bytes at end of rs_buf */
|
|
size_t rs_count; /* bytes till reseed */
|
|
} *rs;
|
|
|
|
/* Preserved in fork children. */
|
|
static struct {
|
|
chacha_ctx rs_chacha; /* chacha context for random keystream */
|
|
u_char rs_buf[RSBUFSZ]; /* keystream blocks */
|
|
} *rsx;
|
|
|
|
static inline void _rs_rekey(u_char *dat, size_t datlen);
|
|
|
|
static inline void
|
|
_rs_init(u_char *buf, size_t n)
|
|
{
|
|
if (n < KEYSZ + IVSZ)
|
|
return;
|
|
|
|
if (rs == NULL) {
|
|
#ifndef UB_ON_WINDOWS
|
|
if ((rs = mmap(NULL, sizeof(*rs), PROT_READ|PROT_WRITE,
|
|
MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
|
|
abort();
|
|
#ifdef MAP_INHERIT_ZERO
|
|
if (minherit(rs, sizeof(*rs), MAP_INHERIT_ZERO) == -1)
|
|
abort();
|
|
#endif
|
|
#else /* WINDOWS */
|
|
rs = malloc(sizeof(*rs));
|
|
if(!rs)
|
|
abort();
|
|
#endif
|
|
}
|
|
if (rsx == NULL) {
|
|
#ifndef UB_ON_WINDOWS
|
|
if ((rsx = mmap(NULL, sizeof(*rsx), PROT_READ|PROT_WRITE,
|
|
MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
|
|
abort();
|
|
#else /* WINDOWS */
|
|
rsx = malloc(sizeof(*rsx));
|
|
if(!rsx)
|
|
abort();
|
|
#endif
|
|
}
|
|
|
|
chacha_keysetup(&rsx->rs_chacha, buf, KEYSZ * 8, 0);
|
|
chacha_ivsetup(&rsx->rs_chacha, buf + KEYSZ);
|
|
}
|
|
|
|
static void
|
|
_rs_stir(void)
|
|
{
|
|
u_char rnd[KEYSZ + IVSZ];
|
|
|
|
if (getentropy(rnd, sizeof rnd) == -1) {
|
|
#ifdef SIGKILL
|
|
raise(SIGKILL);
|
|
#else
|
|
exit(9); /* windows */
|
|
#endif
|
|
}
|
|
|
|
if (!rs)
|
|
_rs_init(rnd, sizeof(rnd));
|
|
else
|
|
_rs_rekey(rnd, sizeof(rnd));
|
|
explicit_bzero(rnd, sizeof(rnd)); /* discard source seed */
|
|
|
|
/* invalidate rs_buf */
|
|
rs->rs_have = 0;
|
|
memset(rsx->rs_buf, 0, sizeof(rsx->rs_buf));
|
|
|
|
rs->rs_count = 1600000;
|
|
}
|
|
|
|
static inline void
|
|
_rs_stir_if_needed(size_t len)
|
|
{
|
|
#ifndef MAP_INHERIT_ZERO
|
|
static pid_t _rs_pid = 0;
|
|
pid_t pid = getpid();
|
|
|
|
/* If a system lacks MAP_INHERIT_ZERO, resort to getpid() */
|
|
if (_rs_pid == 0 || _rs_pid != pid) {
|
|
_rs_pid = pid;
|
|
if (rs)
|
|
rs->rs_count = 0;
|
|
}
|
|
#endif
|
|
if (!rs || rs->rs_count <= len)
|
|
_rs_stir();
|
|
if (rs->rs_count <= len)
|
|
rs->rs_count = 0;
|
|
else
|
|
rs->rs_count -= len;
|
|
}
|
|
|
|
static inline void
|
|
_rs_rekey(u_char *dat, size_t datlen)
|
|
{
|
|
#ifndef KEYSTREAM_ONLY
|
|
memset(rsx->rs_buf, 0, sizeof(rsx->rs_buf));
|
|
#endif
|
|
/* fill rs_buf with the keystream */
|
|
chacha_encrypt_bytes(&rsx->rs_chacha, rsx->rs_buf,
|
|
rsx->rs_buf, sizeof(rsx->rs_buf));
|
|
/* mix in optional user provided data */
|
|
if (dat) {
|
|
size_t i, m;
|
|
|
|
m = arc4_min(datlen, KEYSZ + IVSZ);
|
|
for (i = 0; i < m; i++)
|
|
rsx->rs_buf[i] ^= dat[i];
|
|
}
|
|
/* immediately reinit for backtracking resistance */
|
|
_rs_init(rsx->rs_buf, KEYSZ + IVSZ);
|
|
memset(rsx->rs_buf, 0, KEYSZ + IVSZ);
|
|
rs->rs_have = sizeof(rsx->rs_buf) - KEYSZ - IVSZ;
|
|
}
|
|
|
|
static inline void
|
|
_rs_random_buf(void *_buf, size_t n)
|
|
{
|
|
u_char *buf = (u_char *)_buf;
|
|
u_char *keystream;
|
|
size_t m;
|
|
|
|
_rs_stir_if_needed(n);
|
|
while (n > 0) {
|
|
if (rs->rs_have > 0) {
|
|
m = arc4_min(n, rs->rs_have);
|
|
keystream = rsx->rs_buf + sizeof(rsx->rs_buf)
|
|
- rs->rs_have;
|
|
memcpy(buf, keystream, m);
|
|
memset(keystream, 0, m);
|
|
buf += m;
|
|
n -= m;
|
|
rs->rs_have -= m;
|
|
}
|
|
if (rs->rs_have == 0)
|
|
_rs_rekey(NULL, 0);
|
|
}
|
|
}
|
|
|
|
static inline void
|
|
_rs_random_u32(uint32_t *val)
|
|
{
|
|
u_char *keystream;
|
|
_rs_stir_if_needed(sizeof(*val));
|
|
if (rs->rs_have < sizeof(*val))
|
|
_rs_rekey(NULL, 0);
|
|
keystream = rsx->rs_buf + sizeof(rsx->rs_buf) - rs->rs_have;
|
|
memcpy(val, keystream, sizeof(*val));
|
|
memset(keystream, 0, sizeof(*val));
|
|
rs->rs_have -= sizeof(*val);
|
|
}
|
|
|
|
uint32_t
|
|
arc4random(void)
|
|
{
|
|
uint32_t val;
|
|
|
|
_ARC4_LOCK();
|
|
_rs_random_u32(&val);
|
|
_ARC4_UNLOCK();
|
|
return val;
|
|
}
|
|
|
|
void
|
|
arc4random_buf(void *buf, size_t n)
|
|
{
|
|
_ARC4_LOCK();
|
|
_rs_random_buf(buf, n);
|
|
_ARC4_UNLOCK();
|
|
}
|