freebsd-dev/stand/geli/geliboot_crypto.c
2017-11-14 23:02:19 +00:00

141 lines
4.0 KiB
C

/*-
* Copyright (c) 2005-2010 Pawel Jakub Dawidek <pjd@FreeBSD.org>
* Copyright (c) 2015 Allan Jude <allanjude@FreeBSD.org>
* 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.
* 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 AUTHORS AND CONTRIBUTORS ``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 AUTHORS OR CONTRIBUTORS 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 <stdio.h>
#include <string.h>
#include <strings.h>
#include "geliboot_internal.h"
#include "geliboot.h"
int
geliboot_crypt(u_int algo, int enc, u_char *data, size_t datasize,
const u_char *key, size_t keysize, u_char *iv)
{
keyInstance aeskey;
cipherInstance cipher;
struct aes_xts_ctx xtsctx, *ctxp;
size_t xts_len;
int err, blks, i;
switch (algo) {
case CRYPTO_AES_CBC:
err = rijndael_makeKey(&aeskey, !enc, keysize,
(const char *)key);
if (err < 0) {
printf("Failed to setup decryption keys: %d\n", err);
return (err);
}
err = rijndael_cipherInit(&cipher, MODE_CBC, iv);
if (err < 0) {
printf("Failed to setup IV: %d\n", err);
return (err);
}
switch (enc) {
case 0: /* decrypt */
blks = rijndael_blockDecrypt(&cipher, &aeskey, data,
datasize * 8, data);
break;
case 1: /* encrypt */
blks = rijndael_blockEncrypt(&cipher, &aeskey, data,
datasize * 8, data);
break;
}
if (datasize != (blks / 8)) {
printf("Failed to decrypt the entire input: "
"%u != %u\n", blks, datasize);
return (1);
}
break;
case CRYPTO_AES_XTS:
xts_len = keysize << 1;
ctxp = &xtsctx;
rijndael_set_key(&ctxp->key1, key, xts_len / 2);
rijndael_set_key(&ctxp->key2, key + (xts_len / 16), xts_len / 2);
enc_xform_aes_xts.reinit((caddr_t)ctxp, iv);
switch (enc) {
case 0: /* decrypt */
for (i = 0; i < datasize; i += AES_XTS_BLOCKSIZE) {
enc_xform_aes_xts.decrypt((caddr_t)ctxp, data + i);
}
break;
case 1: /* encrypt */
for (i = 0; i < datasize; i += AES_XTS_BLOCKSIZE) {
enc_xform_aes_xts.encrypt((caddr_t)ctxp, data + i);
}
break;
}
break;
default:
printf("Unsupported crypto algorithm #%d\n", algo);
return (1);
}
return (0);
}
static int
g_eli_crypto_cipher(u_int algo, int enc, u_char *data, size_t datasize,
const u_char *key, size_t keysize)
{
u_char iv[keysize];
explicit_bzero(iv, sizeof(iv));
return (geliboot_crypt(algo, enc, data, datasize, key, keysize, iv));
}
int
g_eli_crypto_encrypt(u_int algo, u_char *data, size_t datasize,
const u_char *key, size_t keysize)
{
/* We prefer AES-CBC for metadata protection. */
if (algo == CRYPTO_AES_XTS)
algo = CRYPTO_AES_CBC;
return (g_eli_crypto_cipher(algo, 1, data, datasize, key, keysize));
}
int
g_eli_crypto_decrypt(u_int algo, u_char *data, size_t datasize,
const u_char *key, size_t keysize)
{
/* We prefer AES-CBC for metadata protection. */
if (algo == CRYPTO_AES_XTS)
algo = CRYPTO_AES_CBC;
return (g_eli_crypto_cipher(algo, 0, data, datasize, key, keysize));
}