freebsd-nq/sys/dev/random/hash.c
Mark Murray 4d87a031c0 Large upgrade to the entropy device; mainly inspired by feedback
from many folk.

o The reseed process is now a kthread. With SMPng, kthreads are
  pre-emptive, so the annoying jerkiness of the mouse is gone.

o The data structures are protected by mutexes now, not splfoo()/splx().

o The cryptographic routines are broken out into their own subroutines.
  this facilitates review, and possible replacement if that is ever
  found necessary.

Thanks to:		kris, green, peter, jasone, grog, jhb
Forgotten to thank:	You know who you are; no offense intended.
2000-09-10 13:52:19 +00:00

122 lines
3.6 KiB
C

/*-
* Copyright (c) 2000 Mark R V Murray
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer
* in this position and unchanged.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/queue.h>
#include <sys/libkern.h>
#include <sys/mbuf.h>
#include <sys/random.h>
#include <sys/time.h>
#include <sys/types.h>
#include <crypto/blowfish/blowfish.h>
#include <dev/randomdev/hash.h>
#include <dev/randomdev/yarrow.h>
/* initialise the hash by copying in some supplied data */
void
yarrow_hash_init(struct yarrowhash *context, void *data, size_t size)
{
size_t count;
count = size > KEYSIZE ? KEYSIZE : size;
memset(context->hash, 0xff, KEYSIZE);
memcpy(context->hash, data, count);
}
/* Do a Davies-Meyer hash using a block cipher.
* H_0 = I
* H_i = E_M_i(H_i-1) ^ H_i-1
*/
void
yarrow_hash_iterate(struct yarrowhash *context, void *data, size_t size)
{
u_char keybuffer[KEYSIZE], temp[KEYSIZE];
size_t count;
int iteration, last, i;
iteration = 0;
last = 0;
for (;;) {
if (size <= KEYSIZE)
last = 1;
count = size > KEYSIZE ? KEYSIZE : size;
memcpy(keybuffer, &((u_char *)data)[iteration], count);
memset(&keybuffer[KEYSIZE - count], 0xff, count);
BF_set_key(&context->hashkey, count,
&((u_char *)data)[iteration]);
BF_cbc_encrypt(context->hash, temp, KEYSIZE, &context->hashkey,
context->ivec, BF_ENCRYPT);
for (i = 0; i < KEYSIZE; i++)
context->hash[i] ^= temp[i];
if (last)
break;
iteration += KEYSIZE;
size -= KEYSIZE;
}
}
/* Conclude by returning a pointer to the data */
void
yarrow_hash_finish(struct yarrowhash *context, void *buf)
{
memcpy(buf, context->hash, sizeof(context->hash));
}
/* Initialise the encryption routine by setting up the key schedule */
void
yarrow_encrypt_init(struct yarrowkey *context, void *data, size_t size)
{
size_t count;
count = size > KEYSIZE ? KEYSIZE : size;
BF_set_key(&context->key, size, data);
}
/* Encrypt the supplied data using the key schedule preset in the context */
void
yarrow_encrypt(struct yarrowkey *context, void *d_in, void *d_out, size_t size)
{
size_t count;
int iteration, last;
last = 0;
for (iteration = 0;; iteration += KEYSIZE) {
if (size <= KEYSIZE)
last = 1;
count = size > KEYSIZE ? KEYSIZE : size;
BF_cbc_encrypt(&((u_char *)d_in)[iteration],
&((u_char *)d_out)[iteration], count, &context->key,
context->ivec, BF_ENCRYPT);
if (last)
break;
size -= KEYSIZE;
}
}