2502999acd
Keep xform.c as a meta-file including the broken out bits existing code that includes xform.c continues to work as normal Individual algorithms can now be reused elsewhere, including outside of the kernel Reviewed by: bapt (previous version), gnn, delphij Approved by: secteam MFC after: 1 week Sponsored by: ScaleEngine Inc. Differential Revision: https://reviews.freebsd.org/D4674
165 lines
4.5 KiB
C
165 lines
4.5 KiB
C
/* $OpenBSD: xform.c,v 1.16 2001/08/28 12:20:43 ben Exp $ */
|
|
/*-
|
|
* The authors of this code are John Ioannidis (ji@tla.org),
|
|
* Angelos D. Keromytis (kermit@csd.uch.gr),
|
|
* Niels Provos (provos@physnet.uni-hamburg.de) and
|
|
* Damien Miller (djm@mindrot.org).
|
|
*
|
|
* This code was written by John Ioannidis for BSD/OS in Athens, Greece,
|
|
* in November 1995.
|
|
*
|
|
* Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
|
|
* by Angelos D. Keromytis.
|
|
*
|
|
* Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
|
|
* and Niels Provos.
|
|
*
|
|
* Additional features in 1999 by Angelos D. Keromytis.
|
|
*
|
|
* AES XTS implementation in 2008 by Damien Miller
|
|
*
|
|
* Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
|
|
* Angelos D. Keromytis and Niels Provos.
|
|
*
|
|
* Copyright (C) 2001, Angelos D. Keromytis.
|
|
*
|
|
* Copyright (C) 2008, Damien Miller
|
|
* Copyright (c) 2014 The FreeBSD Foundation
|
|
* All rights reserved.
|
|
*
|
|
* Portions of this software were developed by John-Mark Gurney
|
|
* under sponsorship of the FreeBSD Foundation and
|
|
* Rubicon Communications, LLC (Netgate).
|
|
*
|
|
* Permission to use, copy, and modify this software with or without fee
|
|
* is hereby granted, provided that this entire notice is included in
|
|
* all copies of any software which is or includes a copy or
|
|
* modification of this software.
|
|
* You may use this code under the GNU public license if you so wish. Please
|
|
* contribute changes back to the authors under this freer than GPL license
|
|
* so that we may further the use of strong encryption without limitations to
|
|
* all.
|
|
*
|
|
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
|
|
* IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
|
|
* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
|
|
* MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
|
|
* PURPOSE.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <opencrypto/xform_enc.h>
|
|
|
|
static int aes_xts_setkey(u_int8_t **, u_int8_t *, int);
|
|
static void aes_xts_encrypt(caddr_t, u_int8_t *);
|
|
static void aes_xts_decrypt(caddr_t, u_int8_t *);
|
|
static void aes_xts_zerokey(u_int8_t **);
|
|
static void aes_xts_reinit(caddr_t, u_int8_t *);
|
|
|
|
/* Encryption instances */
|
|
struct enc_xform enc_xform_aes_xts = {
|
|
CRYPTO_AES_XTS, "AES-XTS",
|
|
AES_BLOCK_LEN, AES_XTS_IV_LEN, AES_XTS_MIN_KEY, AES_XTS_MAX_KEY,
|
|
aes_xts_encrypt,
|
|
aes_xts_decrypt,
|
|
aes_xts_setkey,
|
|
aes_xts_zerokey,
|
|
aes_xts_reinit
|
|
};
|
|
|
|
/*
|
|
* Encryption wrapper routines.
|
|
*/
|
|
static void
|
|
aes_xts_reinit(caddr_t key, u_int8_t *iv)
|
|
{
|
|
struct aes_xts_ctx *ctx = (struct aes_xts_ctx *)key;
|
|
u_int64_t blocknum;
|
|
u_int i;
|
|
|
|
/*
|
|
* Prepare tweak as E_k2(IV). IV is specified as LE representation
|
|
* of a 64-bit block number which we allow to be passed in directly.
|
|
*/
|
|
bcopy(iv, &blocknum, AES_XTS_IVSIZE);
|
|
for (i = 0; i < AES_XTS_IVSIZE; i++) {
|
|
ctx->tweak[i] = blocknum & 0xff;
|
|
blocknum >>= 8;
|
|
}
|
|
/* Last 64 bits of IV are always zero */
|
|
bzero(ctx->tweak + AES_XTS_IVSIZE, AES_XTS_IVSIZE);
|
|
|
|
rijndael_encrypt(&ctx->key2, ctx->tweak, ctx->tweak);
|
|
}
|
|
|
|
static void
|
|
aes_xts_crypt(struct aes_xts_ctx *ctx, u_int8_t *data, u_int do_encrypt)
|
|
{
|
|
u_int8_t block[AES_XTS_BLOCKSIZE];
|
|
u_int i, carry_in, carry_out;
|
|
|
|
for (i = 0; i < AES_XTS_BLOCKSIZE; i++)
|
|
block[i] = data[i] ^ ctx->tweak[i];
|
|
|
|
if (do_encrypt)
|
|
rijndael_encrypt(&ctx->key1, block, data);
|
|
else
|
|
rijndael_decrypt(&ctx->key1, block, data);
|
|
|
|
for (i = 0; i < AES_XTS_BLOCKSIZE; i++)
|
|
data[i] ^= ctx->tweak[i];
|
|
|
|
/* Exponentiate tweak */
|
|
carry_in = 0;
|
|
for (i = 0; i < AES_XTS_BLOCKSIZE; i++) {
|
|
carry_out = ctx->tweak[i] & 0x80;
|
|
ctx->tweak[i] = (ctx->tweak[i] << 1) | (carry_in ? 1 : 0);
|
|
carry_in = carry_out;
|
|
}
|
|
if (carry_in)
|
|
ctx->tweak[0] ^= AES_XTS_ALPHA;
|
|
bzero(block, sizeof(block));
|
|
}
|
|
|
|
static void
|
|
aes_xts_encrypt(caddr_t key, u_int8_t *data)
|
|
{
|
|
aes_xts_crypt((struct aes_xts_ctx *)key, data, 1);
|
|
}
|
|
|
|
static void
|
|
aes_xts_decrypt(caddr_t key, u_int8_t *data)
|
|
{
|
|
aes_xts_crypt((struct aes_xts_ctx *)key, data, 0);
|
|
}
|
|
|
|
static int
|
|
aes_xts_setkey(u_int8_t **sched, u_int8_t *key, int len)
|
|
{
|
|
struct aes_xts_ctx *ctx;
|
|
|
|
if (len != 32 && len != 64)
|
|
return EINVAL;
|
|
|
|
*sched = KMALLOC(sizeof(struct aes_xts_ctx), M_CRYPTO_DATA,
|
|
M_NOWAIT | M_ZERO);
|
|
if (*sched == NULL)
|
|
return ENOMEM;
|
|
ctx = (struct aes_xts_ctx *)*sched;
|
|
|
|
rijndael_set_key(&ctx->key1, key, len * 4);
|
|
rijndael_set_key(&ctx->key2, key + (len / 2), len * 4);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
aes_xts_zerokey(u_int8_t **sched)
|
|
{
|
|
bzero(*sched, sizeof(struct aes_xts_ctx));
|
|
KFREE(*sched, M_CRYPTO_DATA);
|
|
*sched = NULL;
|
|
}
|