1/*	$OpenBSD: xform.c,v 1.16 2001/08/28 12:20:43 ben Exp $	*/
2/*-
3 * The authors of this code are John Ioannidis (ji@tla.org),
4 * Angelos D. Keromytis (kermit@csd.uch.gr),
5 * Niels Provos (provos@physnet.uni-hamburg.de) and
6 * Damien Miller (djm@mindrot.org).
7 *
8 * This code was written by John Ioannidis for BSD/OS in Athens, Greece,
9 * in November 1995.
10 *
11 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
12 * by Angelos D. Keromytis.
13 *
14 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
15 * and Niels Provos.
16 *
17 * Additional features in 1999 by Angelos D. Keromytis.
18 *
19 * AES XTS implementation in 2008 by Damien Miller
20 *
21 * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
22 * Angelos D. Keromytis and Niels Provos.
23 *
24 * Copyright (C) 2001, Angelos D. Keromytis.
25 *
26 * Copyright (C) 2008, Damien Miller
27 * Copyright (c) 2014 The FreeBSD Foundation
28 * All rights reserved.
29 *
30 * Portions of this software were developed by John-Mark Gurney
31 * under sponsorship of the FreeBSD Foundation and
32 * Rubicon Communications, LLC (Netgate).
33 *
34 * Permission to use, copy, and modify this software with or without fee
35 * is hereby granted, provided that this entire notice is included in
36 * all copies of any software which is or includes a copy or
37 * modification of this software.
38 * You may use this code under the GNU public license if you so wish. Please
39 * contribute changes back to the authors under this freer than GPL license
40 * so that we may further the use of strong encryption without limitations to
41 * all.
42 *
43 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
44 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
45 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
46 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
47 * PURPOSE.
48 */
49
50#include <sys/cdefs.h>
51__FBSDID("$FreeBSD$");
52
53#include <opencrypto/xform_enc.h>
54
55static	int aes_icm_setkey(u_int8_t **, u_int8_t *, int);
56static	void aes_icm_crypt(caddr_t, u_int8_t *);
57static	void aes_icm_zerokey(u_int8_t **);
58static	void aes_icm_reinit(caddr_t, u_int8_t *);
59static	void aes_gcm_reinit(caddr_t, u_int8_t *);
60static	void aes_ccm_reinit(caddr_t, u_int8_t *);
61
62/* Encryption instances */
63struct enc_xform enc_xform_aes_icm = {
64	CRYPTO_AES_ICM, "AES-ICM",
65	AES_BLOCK_LEN, AES_BLOCK_LEN, AES_MIN_KEY, AES_MAX_KEY,
66	aes_icm_crypt,
67	aes_icm_crypt,
68	aes_icm_setkey,
69	aes_icm_zerokey,
70	aes_icm_reinit,
71};
72
73struct enc_xform enc_xform_aes_nist_gcm = {
74	CRYPTO_AES_NIST_GCM_16, "AES-GCM",
75	AES_ICM_BLOCK_LEN, AES_GCM_IV_LEN, AES_MIN_KEY, AES_MAX_KEY,
76	aes_icm_crypt,
77	aes_icm_crypt,
78	aes_icm_setkey,
79	aes_icm_zerokey,
80	aes_gcm_reinit,
81};
82
83struct enc_xform enc_xform_ccm = {
84	.type = CRYPTO_AES_CCM_16,
85	.name = "AES-CCM",
86	.blocksize = AES_ICM_BLOCK_LEN, .ivsize = AES_CCM_IV_LEN,
87	.minkey = AES_MIN_KEY, .maxkey = AES_MAX_KEY,
88	.encrypt = aes_icm_crypt,
89	.decrypt = aes_icm_crypt,
90	.setkey = aes_icm_setkey,
91	.zerokey = aes_icm_zerokey,
92	.reinit = aes_ccm_reinit,
93};
94
95/*
96 * Encryption wrapper routines.
97 */
98static void
99aes_icm_reinit(caddr_t key, u_int8_t *iv)
100{
101	struct aes_icm_ctx *ctx;
102
103	ctx = (struct aes_icm_ctx *)key;
104	bcopy(iv, ctx->ac_block, AESICM_BLOCKSIZE);
105}
106
107static void
108aes_gcm_reinit(caddr_t key, u_int8_t *iv)
109{
110	struct aes_icm_ctx *ctx;
111
112	aes_icm_reinit(key, iv);
113
114	ctx = (struct aes_icm_ctx *)key;
115	/* GCM starts with 2 as counter 1 is used for final xor of tag. */
116	bzero(&ctx->ac_block[AESICM_BLOCKSIZE - 4], 4);
117	ctx->ac_block[AESICM_BLOCKSIZE - 1] = 2;
118}
119
120static void
121aes_ccm_reinit(caddr_t key, u_int8_t *iv)
122{
123	struct aes_icm_ctx *ctx;
124
125	ctx = (struct aes_icm_ctx*)key;
126
127	/* CCM has flags, then the IV, then the counter, which starts at 1 */
128	bzero(ctx->ac_block, sizeof(ctx->ac_block));
129	/* 3 bytes for length field; this gives a nonce of 12 bytes */
130	ctx->ac_block[0] = (15 - AES_CCM_IV_LEN) - 1;
131	bcopy(iv, ctx->ac_block+1, AES_CCM_IV_LEN);
132	ctx->ac_block[AESICM_BLOCKSIZE - 1] = 1;
133}
134
135static void
136aes_icm_crypt(caddr_t key, u_int8_t *data)
137{
138	struct aes_icm_ctx *ctx;
139	u_int8_t keystream[AESICM_BLOCKSIZE];
140	int i;
141
142	ctx = (struct aes_icm_ctx *)key;
143	rijndaelEncrypt(ctx->ac_ek, ctx->ac_nr, ctx->ac_block, keystream);
144	for (i = 0; i < AESICM_BLOCKSIZE; i++)
145		data[i] ^= keystream[i];
146	explicit_bzero(keystream, sizeof(keystream));
147
148	/* increment counter */
149	for (i = AESICM_BLOCKSIZE - 1;
150	     i >= 0; i--)
151		if (++ctx->ac_block[i])   /* continue on overflow */
152			break;
153}
154
155static int
156aes_icm_setkey(u_int8_t **sched, u_int8_t *key, int len)
157{
158	struct aes_icm_ctx *ctx;
159
160	if (len != 16 && len != 24 && len != 32)
161		return EINVAL;
162
163	*sched = KMALLOC(sizeof(struct aes_icm_ctx), M_CRYPTO_DATA,
164	    M_NOWAIT | M_ZERO);
165	if (*sched == NULL)
166		return ENOMEM;
167
168	ctx = (struct aes_icm_ctx *)*sched;
169	ctx->ac_nr = rijndaelKeySetupEnc(ctx->ac_ek, (u_char *)key, len * 8);
170	return 0;
171}
172
173static void
174aes_icm_zerokey(u_int8_t **sched)
175{
176
177	bzero(*sched, sizeof(struct aes_icm_ctx));
178	KFREE(*sched, M_CRYPTO_DATA);
179	*sched = NULL;
180}
181