1/*-
2 * Copyright (c) 2005-2010 Pawel Jakub Dawidek <pjd@FreeBSD.org>
3 * Copyright (c) 2015 Allan Jude <allanjude@FreeBSD.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD$
28 */
29
30#include <stdio.h>
31#include <string.h>
32#include <strings.h>
33
34#include "geliboot_internal.h"
35#include "geliboot.h"
36
37int
38geliboot_crypt(u_int algo, int enc, u_char *data, size_t datasize,
39    const u_char *key, size_t keysize, u_char *iv)
40{
41	keyInstance aeskey;
42	cipherInstance cipher;
43	struct aes_xts_ctx xtsctx, *ctxp;
44	size_t xts_len;
45	int err, blks, i;
46
47	switch (algo) {
48	case CRYPTO_AES_CBC:
49		err = rijndael_makeKey(&aeskey, !enc, keysize,
50		    (const char *)key);
51		if (err < 0) {
52			printf("Failed to setup decryption keys: %d\n", err);
53			return (err);
54		}
55
56		err = rijndael_cipherInit(&cipher, MODE_CBC, iv);
57		if (err < 0) {
58			printf("Failed to setup IV: %d\n", err);
59			return (err);
60		}
61
62		if (enc == 0) {
63			/* decrypt */
64			blks = rijndael_blockDecrypt(&cipher, &aeskey, data,
65			    datasize * 8, data);
66		} else {
67			/* encrypt */
68			blks = rijndael_blockEncrypt(&cipher, &aeskey, data,
69			    datasize * 8, data);
70		}
71		if (datasize != (blks / 8)) {
72			printf("Failed to decrypt the entire input: "
73			    "%u != %zu\n", blks, datasize);
74			return (1);
75		}
76		break;
77	case CRYPTO_AES_XTS:
78		xts_len = keysize << 1;
79		ctxp = &xtsctx;
80
81		rijndael_set_key(&ctxp->key1, key, xts_len / 2);
82		rijndael_set_key(&ctxp->key2, key + (xts_len / 16), xts_len / 2);
83
84		enc_xform_aes_xts.reinit((caddr_t)ctxp, iv);
85
86		switch (enc) {
87		case 0: /* decrypt */
88			for (i = 0; i < datasize; i += AES_XTS_BLOCKSIZE) {
89				enc_xform_aes_xts.decrypt((caddr_t)ctxp, data + i);
90			}
91			break;
92		case 1: /* encrypt */
93			for (i = 0; i < datasize; i += AES_XTS_BLOCKSIZE) {
94				enc_xform_aes_xts.encrypt((caddr_t)ctxp, data + i);
95			}
96			break;
97		}
98		break;
99	default:
100		printf("Unsupported crypto algorithm #%d\n", algo);
101		return (1);
102	}
103
104	return (0);
105}
106
107static int
108g_eli_crypto_cipher(u_int algo, int enc, u_char *data, size_t datasize,
109    const u_char *key, size_t keysize)
110{
111	u_char iv[keysize];
112
113	explicit_bzero(iv, sizeof(iv));
114	return (geliboot_crypt(algo, enc, data, datasize, key, keysize, iv));
115}
116
117int
118g_eli_crypto_encrypt(u_int algo, u_char *data, size_t datasize,
119    const u_char *key, size_t keysize)
120{
121
122	/* We prefer AES-CBC for metadata protection. */
123	if (algo == CRYPTO_AES_XTS)
124		algo = CRYPTO_AES_CBC;
125
126	return (g_eli_crypto_cipher(algo, 1, data, datasize, key, keysize));
127}
128
129int
130g_eli_crypto_decrypt(u_int algo, u_char *data, size_t datasize,
131    const u_char *key, size_t keysize)
132{
133
134	/* We prefer AES-CBC for metadata protection. */
135	if (algo == CRYPTO_AES_XTS)
136		algo = CRYPTO_AES_CBC;
137
138	return (g_eli_crypto_cipher(algo, 0, data, datasize, key, keysize));
139}
140