freebsd-skq/sys/dev/random/hash.c
markm ad4dd3b5a2 Very large makeover of the /dev/random driver.
o Separate the kernel stuff from the Yarrow algorithm. Yarrow is now
  well contained in one source file and one header.

o Replace the Blowfish-based crypto routines with Rijndael-based ones.
  (Rijndael is the new AES algorithm). The huge improvement in
  Rijndael's key-agility over Blowfish means that this is an
  extremely dramatic improvement in speed, and makes a heck of
  a difference in its (lack of) CPU load.

o Clean up the sysctl's. At BDE's prompting, I have gone back to
  static sysctls.

o Bug fixes. The streamlining of the crypto stuff enabled me to
  find and fix some bugs. DES also found a bug in the reseed routine
  which is fixed.

o Change the way reseeds clear "used" entropy. Previously, only the
  source(s) that caused a reseed were cleared. Now all sources in the
  relevant pool(s) are cleared.

o Code tidy-up. Mostly to make it (nearly) 80-column compliant.
2001-03-10 12:51:55 +00:00

118 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/random.h>
#include <sys/types.h>
#include <crypto/rijndael/rijndael.h>
#include <dev/random/hash.h>
/* initialise the hash by zeroing it */
void
yarrow_hash_init(struct yarrowhash *context)
{
rijndael_cipherInit(&context->cipher, MODE_CBC, NULL);
bzero(context->hash, KEYSIZE);
context->partial = 0;
}
/* 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 temp[KEYSIZE];
u_int i, j;
for (i = 0; i < size; i++) {
context->accum[context->partial++] = ((u_char *)(data))[i];
if (context->partial == (KEYSIZE - 1)) {
rijndael_makeKey(&context->hashkey, DIR_ENCRYPT,
KEYSIZE*8, context->accum);
rijndael_blockEncrypt(&context->cipher,
&context->hashkey, context->hash,
KEYSIZE*8, temp);
for (j = 0; j < KEYSIZE; j++)
context->hash[j] ^= temp[j];
bzero(context->accum, KEYSIZE);
context->partial = 0;
}
}
}
/* Conclude by returning the hash in the supplied /buf/ which must be
* KEYSIZE bytes long. Trailing data (less than KEYSIZE bytes) are
* not forgotten.
*/
void
yarrow_hash_finish(struct yarrowhash *context, void *buf)
{
u_char temp[KEYSIZE];
int i;
if (context->partial) {
rijndael_makeKey(&context->hashkey, DIR_ENCRYPT,
KEYSIZE*8, context->accum);
rijndael_blockEncrypt(&context->cipher,
&context->hashkey, context->hash,
KEYSIZE*8, temp);
for (i = 0; i < KEYSIZE; i++)
context->hash[i] ^= temp[i];
}
memcpy(buf, context->hash, KEYSIZE);
bzero(context->hash, KEYSIZE);
}
/* Initialise the encryption routine by setting up the key schedule
* from the supplied /key/ which must be KEYSIZE bytes of binary
* data.
*/
void
yarrow_encrypt_init(struct yarrowkey *context, void *data)
{
rijndael_cipherInit(&context->cipher, MODE_CBC, NULL);
rijndael_makeKey(&context->key, DIR_ENCRYPT, KEYSIZE*8, data);
}
/* Encrypt the supplied data using the key schedule preset in the context.
* KEYSIZE bytes are encrypted from /d_in/ to /d_out/.
*/
void
yarrow_encrypt(struct yarrowkey *context, void *d_in, void *d_out)
{
rijndael_blockEncrypt(&context->cipher, &context->key, d_in,
KEYSIZE*8, d_out);
}