freebsd-dev/sys/dev/random/hash.c
Mark Murray bbf09ad887 Upgrade the random device to use a "real" hash instead of building
one out of a block cipher. This has 2 advantages:
1) The code is _much_ simpler
2) We aren't committing our security to one algorithm (much as we
   may think we trust AES).

While I'm here, make an explicit reseed do a slow reseed instead
of a fast; this is in line with what the original paper suggested.
2002-07-15 13:58:35 +00:00

81 lines
2.6 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 <crypto/rijndael/rijndael.h>
#include <crypto/sha2/sha2.h>
#include <dev/random/hash.h>
/* initialise the hash */
void
yarrow_hash_init(struct yarrowhash *context)
{
SHA256_Init(&context->sha);
}
/* iterate the hash */
void
yarrow_hash_iterate(struct yarrowhash *context, void *data, size_t size)
{
SHA256_Update(&context->sha, data, size);
}
/* 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)
{
SHA256_Final(buf, &context->sha);
}
/* 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);
}