static unsigned int
alt_arc4_getword(void)
{
unsigned int val;
val = ((unsigned int) alt_arc4_getbyte()) << 24;
val |= ((unsigned int) alt_arc4_getbyte()) << 16;
val |= ((unsigned int) alt_arc4_getbyte()) << 8;
val |= ((unsigned int) alt_arc4_getbyte());
return val;
}
static crypto_uint4
alt_arc4_getword(void)
{
crypto_uint4 val;
val = ((crypto_uint4) alt_arc4_getbyte()) << 24;
val |= ((crypto_uint4) alt_arc4_getbyte()) << 16;
val |= ((crypto_uint4) alt_arc4_getbyte()) << 8;
val |= ((crypto_uint4) alt_arc4_getbyte());
return val;
}
static void
alt_arc4_stir(void)
{
int i;
unsigned char rnd[128];
if (!rs_initialized) {
alt_arc4_init();
rs_initialized = 1;
}
if (random_data_source_fd != -1) {
safe_read(random_data_source_fd, rnd, sizeof rnd);
} else {
#ifdef HAVE_RANDOM_DEV
_exit(1);
#else
size_t i = (size_t) 0U;
# ifdef HAVE_ARC4RANDOM
u_int32_t r;
do {
r = arc4random();
memcpy(&rnd[i], &r, (size_t) 4U);
i += (size_t) 4U;
} while (i < sizeof(rnd));
# elif defined(HAVE_RANDOM)
unsigned short r;
do {
r = (unsigned short) random();
rnd[i++] = r & 0xFF;
rnd[i++] = (r << 8) & 0xFF;
} while (i < sizeof(rnd));
# else
unsigned char r;
do {
r = (unsigned char) rand();
rnd[i++] = r;
} while (i < sizeof(rnd));
# endif
#endif
}
alt_arc4_addrandom(rnd, sizeof(rnd));
/*
* Discard early keystream, as per recommendations in:
* http://www.wisdom.weizmann.ac.il/~itsik/RC4/Papers/Rc4_ksa.ps
*/
for (i = 0; i < 256; i++) {
(void) alt_arc4_getbyte();
}
alt_arc4_count = 1600000;
}
void
alt_arc4random_buf(void *_buf, size_t n)
{
unsigned char *buf = (unsigned char *)_buf;
_alt_arc4_LOCK();
alt_arc4_stir_if_needed();
while (n--) {
if (--alt_arc4_count <= 0) {
alt_arc4_stir();
}
buf[n] = alt_arc4_getbyte();
}
_alt_arc4_UNLOCK();
}
