void noise_get_heavy(void (*func) (void *, int))
{
noise_get_light(func);
noise_get_processes(func);
read_random_seed(func);
/* Update the seed immediately, in case another instance uses it. */
random_save_seed();
}
static void random_stir(void)
{
word32 block[HASHINPUT / sizeof(word32)];
word32 digest[HASHSIZE / sizeof(word32)];
int i, j, k;
/*
* noise_get_light will call random_add_noise, which may call
* back to here. Prevent recursive stirs.
*/
if (pool.stir_pending)
return;
pool.stir_pending = TRUE;
noise_get_light(random_add_noise);
SHATransform((word32 *) pool.incoming, (word32 *) pool.incomingb);
pool.incomingpos = 0;
/*
* Chunks of this code are blatantly endianness-dependent, but
* as it's all random bits anyway, WHO CARES?
*/
memcpy(digest, pool.incoming, sizeof(digest));
/*
* Make two passes over the pool.
*/
for (i = 0; i < 2; i++) {
/*
* We operate SHA in CFB mode, repeatedly adding the same
* block of data to the digest. But we're also fiddling
* with the digest-so-far, so this shouldn't be Bad or
* anything.
*/
memcpy(block, pool.pool, sizeof(block));
/*
* Each pass processes the pool backwards in blocks of
* HASHSIZE, just so that in general we get the output of
* SHA before the corresponding input, in the hope that
* things will be that much less predictable that way
* round, when we subsequently return bytes ...
*/
for (j = POOLSIZE; (j -= HASHSIZE) >= 0;) {
/*
* XOR the bit of the pool we're processing into the
* digest.
*/
for (k = 0; k < sizeof(digest) / sizeof(*digest); k++)
digest[k] ^= ((word32 *) (pool.pool + j))[k];
/*
* Munge our unrevealed first block of the pool into
* it.
*/
SHATransform(digest, block);
/*
* Stick the result back into the pool.
*/
for (k = 0; k < sizeof(digest) / sizeof(*digest); k++)
((word32 *) (pool.pool + j))[k] = digest[k];
}
}
/*
* Might as well save this value back into `incoming', just so
* there'll be some extra bizarreness there.
*/
SHATransform(digest, block);
memcpy(pool.incoming, digest, sizeof(digest));
pool.poolpos = sizeof(pool.incoming);
pool.stir_pending = FALSE;
}