/* $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_icm_setkey(void *, const uint8_t *, int);
static void aes_icm_crypt(void *, const uint8_t *, uint8_t *);
static void aes_icm_crypt_last(void *, const uint8_t *, uint8_t *, size_t);
static void aes_icm_reinit(void *, const uint8_t *);
static void aes_gcm_reinit(void *, const uint8_t *);
static void aes_ccm_reinit(void *, const uint8_t *);
/* Encryption instances */
struct enc_xform enc_xform_aes_icm = {
.type = CRYPTO_AES_ICM,
.name = "AES-ICM",
.ctxsize = sizeof(struct aes_icm_ctx),
.blocksize = 1,
.native_blocksize = AES_BLOCK_LEN,
.ivsize = AES_BLOCK_LEN,
.minkey = AES_MIN_KEY,
.maxkey = AES_MAX_KEY,
.encrypt = aes_icm_crypt,
.decrypt = aes_icm_crypt,
.setkey = aes_icm_setkey,
.reinit = aes_icm_reinit,
.encrypt_last = aes_icm_crypt_last,
.decrypt_last = aes_icm_crypt_last,
};
struct enc_xform enc_xform_aes_nist_gcm = {
.type = CRYPTO_AES_NIST_GCM_16,
.name = "AES-GCM",
.ctxsize = sizeof(struct aes_icm_ctx),
.blocksize = 1,
.native_blocksize = AES_BLOCK_LEN,
.ivsize = AES_GCM_IV_LEN,
.minkey = AES_MIN_KEY,
.maxkey = AES_MAX_KEY,
.encrypt = aes_icm_crypt,
.decrypt = aes_icm_crypt,
.setkey = aes_icm_setkey,
.reinit = aes_gcm_reinit,
.encrypt_last = aes_icm_crypt_last,
.decrypt_last = aes_icm_crypt_last,
};
struct enc_xform enc_xform_ccm = {
.type = CRYPTO_AES_CCM_16,
.name = "AES-CCM",
.ctxsize = sizeof(struct aes_icm_ctx),
.blocksize = 1,
.native_blocksize = AES_BLOCK_LEN,
.ivsize = AES_CCM_IV_LEN,
.minkey = AES_MIN_KEY, .maxkey = AES_MAX_KEY,
.encrypt = aes_icm_crypt,
.decrypt = aes_icm_crypt,
.setkey = aes_icm_setkey,
.reinit = aes_ccm_reinit,
.encrypt_last = aes_icm_crypt_last,
.decrypt_last = aes_icm_crypt_last,
};
/*
* Encryption wrapper routines.
*/
static void
aes_icm_reinit(void *key, const uint8_t *iv)
{
struct aes_icm_ctx *ctx;
ctx = key;
bcopy(iv, ctx->ac_block, AESICM_BLOCKSIZE);
}
static void
aes_gcm_reinit(void *key, const uint8_t *iv)
{
struct aes_icm_ctx *ctx;
aes_icm_reinit(key, iv);
ctx = key;
/* GCM starts with 2 as counter 1 is used for final xor of tag. */
bzero(&ctx->ac_block[AESICM_BLOCKSIZE - 4], 4);
ctx->ac_block[AESICM_BLOCKSIZE - 1] = 2;
}
static void
aes_ccm_reinit(void *key, const uint8_t *iv)
{
struct aes_icm_ctx *ctx;
ctx = key;
/* CCM has flags, then the IV, then the counter, which starts at 1 */
bzero(ctx->ac_block, sizeof(ctx->ac_block));
/* 3 bytes for length field; this gives a nonce of 12 bytes */
ctx->ac_block[0] = (15 - AES_CCM_IV_LEN) - 1;
bcopy(iv, ctx->ac_block+1, AES_CCM_IV_LEN);
ctx->ac_block[AESICM_BLOCKSIZE - 1] = 1;
}
static void
aes_icm_crypt(void *key, const uint8_t *in, uint8_t *out)
{
struct aes_icm_ctx *ctx;
int i;
ctx = key;
aes_icm_crypt_last(key, in, out, AESICM_BLOCKSIZE);
/* increment counter */
for (i = AESICM_BLOCKSIZE - 1;
i >= 0; i--)
if (++ctx->ac_block[i]) /* continue on overflow */
break;
}
static void
aes_icm_crypt_last(void *key, const uint8_t *in, uint8_t *out, size_t len)
{
struct aes_icm_ctx *ctx;
uint8_t keystream[AESICM_BLOCKSIZE];
int i;
ctx = key;
rijndaelEncrypt(ctx->ac_ek, ctx->ac_nr, ctx->ac_block, keystream);
for (i = 0; i < len; i++)
out[i] = in[i] ^ keystream[i];
explicit_bzero(keystream, sizeof(keystream));
}
static int
aes_icm_setkey(void *sched, const uint8_t *key, int len)
{
struct aes_icm_ctx *ctx;
if (len != 16 && len != 24 && len != 32)
return (EINVAL);
ctx = sched;
ctx->ac_nr = rijndaelKeySetupEnc(ctx->ac_ek, key, len * 8);
return (0);
}
