xref: /freebsd/stand/libsa/geli/geliboot_crypto.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
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 
28 #include <stdio.h>
29 #include <string.h>
30 #include <strings.h>
31 
32 #include "geliboot_internal.h"
33 #include "geliboot.h"
34 
35 int
36 geliboot_crypt(u_int algo, geli_op_t enc, u_char *data, size_t datasize,
37     const u_char *key, size_t keysize, u_char *iv)
38 {
39 	keyInstance aeskey;
40 	cipherInstance cipher;
41 	struct aes_xts_ctx xtsctx, *ctxp;
42 	size_t xts_len;
43 	int err, blks;
44 
45 	switch (algo) {
46 	case CRYPTO_AES_CBC:
47 		err = rijndael_makeKey(&aeskey, !enc, keysize,
48 		    (const char *)key);
49 		if (err < 0) {
50 			printf("Failed to setup crypo keys: %d\n", err);
51 			return (err);
52 		}
53 
54 		err = rijndael_cipherInit(&cipher, MODE_CBC, iv);
55 		if (err < 0) {
56 			printf("Failed to setup IV: %d\n", err);
57 			return (err);
58 		}
59 
60 		switch (enc) {
61 		case GELI_DECRYPT:
62 			blks = rijndael_blockDecrypt(&cipher, &aeskey, data,
63 			    datasize * 8, data);
64 			break;
65 		case GELI_ENCRYPT:
66 			blks = rijndael_blockEncrypt(&cipher, &aeskey, data,
67 			    datasize * 8, data);
68 			break;
69 		}
70 		if (datasize != (blks / 8)) {
71 			printf("Failed to %s the entire input: %u != %zu\n",
72 			    enc ? "decrypt" : "encrypt",
73 			    blks, datasize);
74 			return (1);
75 		}
76 		break;
77 	case CRYPTO_AES_XTS:
78 		xts_len = keysize << 1;
79 		ctxp = &xtsctx;
80 
81 		enc_xform_aes_xts.setkey(ctxp, key, xts_len / 8);
82 		enc_xform_aes_xts.reinit(ctxp, iv, AES_XTS_IV_LEN);
83 
84 		switch (enc) {
85 		case GELI_DECRYPT:
86 			enc_xform_aes_xts.decrypt_multi(ctxp, data, data,
87 			    datasize);
88 			break;
89 		case GELI_ENCRYPT:
90 			enc_xform_aes_xts.encrypt_multi(ctxp, data, data,
91 			    datasize);
92 			break;
93 		}
94 		break;
95 	default:
96 		printf("Unsupported crypto algorithm #%d\n", algo);
97 		return (1);
98 	}
99 
100 	return (0);
101 }
102 
103 static int
104 g_eli_crypto_cipher(u_int algo, geli_op_t enc, u_char *data, size_t datasize,
105     const u_char *key, size_t keysize)
106 {
107 	u_char iv[G_ELI_IVKEYLEN];
108 
109 	explicit_bzero(iv, sizeof(iv));
110 	return (geliboot_crypt(algo, enc, data, datasize, key, keysize, iv));
111 }
112 
113 int
114 g_eli_crypto_encrypt(u_int algo, u_char *data, size_t datasize,
115     const u_char *key, size_t keysize)
116 {
117 
118 	/* We prefer AES-CBC for metadata protection. */
119 	if (algo == CRYPTO_AES_XTS)
120 		algo = CRYPTO_AES_CBC;
121 
122 	return (g_eli_crypto_cipher(algo, GELI_ENCRYPT, data, datasize, key,
123 	    keysize));
124 }
125 
126 int
127 g_eli_crypto_decrypt(u_int algo, u_char *data, size_t datasize,
128     const u_char *key, size_t keysize)
129 {
130 
131 	/* We prefer AES-CBC for metadata protection. */
132 	if (algo == CRYPTO_AES_XTS)
133 		algo = CRYPTO_AES_CBC;
134 
135 	return (g_eli_crypto_cipher(algo, GELI_DECRYPT, data, datasize, key,
136 	    keysize));
137 }
138