xref: /freebsd/stand/libsa/geli/geliboot_crypto.c (revision 964219664dcec4198441910904fb9064569d174d)
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 
37 int
38 geliboot_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 		switch (enc) {
63 		case 0: /* decrypt */
64 			blks = rijndael_blockDecrypt(&cipher, &aeskey, data,
65 			    datasize * 8, data);
66 			break;
67 		case 1: /* encrypt */
68 			blks = rijndael_blockEncrypt(&cipher, &aeskey, data,
69 			    datasize * 8, data);
70 			break;
71 		}
72 		if (datasize != (blks / 8)) {
73 			printf("Failed to decrypt the entire input: "
74 			    "%u != %zu\n", blks, datasize);
75 			return (1);
76 		}
77 		break;
78 	case CRYPTO_AES_XTS:
79 		xts_len = keysize << 1;
80 		ctxp = &xtsctx;
81 
82 		rijndael_set_key(&ctxp->key1, key, xts_len / 2);
83 		rijndael_set_key(&ctxp->key2, key + (xts_len / 16), xts_len / 2);
84 
85 		enc_xform_aes_xts.reinit((caddr_t)ctxp, iv);
86 
87 		switch (enc) {
88 		case 0: /* decrypt */
89 			for (i = 0; i < datasize; i += AES_XTS_BLOCKSIZE) {
90 				enc_xform_aes_xts.decrypt((caddr_t)ctxp, data + i);
91 			}
92 			break;
93 		case 1: /* encrypt */
94 			for (i = 0; i < datasize; i += AES_XTS_BLOCKSIZE) {
95 				enc_xform_aes_xts.encrypt((caddr_t)ctxp, data + i);
96 			}
97 			break;
98 		}
99 		break;
100 	default:
101 		printf("Unsupported crypto algorithm #%d\n", algo);
102 		return (1);
103 	}
104 
105 	return (0);
106 }
107 
108 static int
109 g_eli_crypto_cipher(u_int algo, int enc, u_char *data, size_t datasize,
110     const u_char *key, size_t keysize)
111 {
112 	u_char iv[keysize];
113 
114 	explicit_bzero(iv, sizeof(iv));
115 	return (geliboot_crypt(algo, enc, data, datasize, key, keysize, iv));
116 }
117 
118 int
119 g_eli_crypto_encrypt(u_int algo, u_char *data, size_t datasize,
120     const u_char *key, size_t keysize)
121 {
122 
123 	/* We prefer AES-CBC for metadata protection. */
124 	if (algo == CRYPTO_AES_XTS)
125 		algo = CRYPTO_AES_CBC;
126 
127 	return (g_eli_crypto_cipher(algo, 1, data, datasize, key, keysize));
128 }
129 
130 int
131 g_eli_crypto_decrypt(u_int algo, u_char *data, size_t datasize,
132     const u_char *key, size_t keysize)
133 {
134 
135 	/* We prefer AES-CBC for metadata protection. */
136 	if (algo == CRYPTO_AES_XTS)
137 		algo = CRYPTO_AES_CBC;
138 
139 	return (g_eli_crypto_cipher(algo, 0, data, datasize, key, keysize));
140 }
141