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(void *, const uint8_t *, int);
56static	void aes_icm_crypt(void *, const uint8_t *, uint8_t *);
57static	void aes_icm_crypt_last(void *, const uint8_t *, uint8_t *, size_t);
58static	void aes_icm_reinit(void *, const uint8_t *);
59static	void aes_gcm_reinit(void *, const uint8_t *);
60static	void aes_ccm_reinit(void *, const uint8_t *);
61
62/* Encryption instances */
63struct enc_xform enc_xform_aes_icm = {
64	.type = CRYPTO_AES_ICM,
65	.name = "AES-ICM",
66	.ctxsize = sizeof(struct aes_icm_ctx),
67	.blocksize = 1,
68	.native_blocksize = AES_BLOCK_LEN,
69	.ivsize = AES_BLOCK_LEN,
70	.minkey = AES_MIN_KEY,
71	.maxkey = AES_MAX_KEY,
72	.encrypt = aes_icm_crypt,
73	.decrypt = aes_icm_crypt,
74	.setkey = aes_icm_setkey,
75	.reinit = aes_icm_reinit,
76	.encrypt_last = aes_icm_crypt_last,
77	.decrypt_last = aes_icm_crypt_last,
78};
79
80struct enc_xform enc_xform_aes_nist_gcm = {
81	.type = CRYPTO_AES_NIST_GCM_16,
82	.name = "AES-GCM",
83	.ctxsize = sizeof(struct aes_icm_ctx),
84	.blocksize = 1,
85	.native_blocksize = AES_BLOCK_LEN,
86	.ivsize = AES_GCM_IV_LEN,
87	.minkey = AES_MIN_KEY,
88	.maxkey = AES_MAX_KEY,
89	.encrypt = aes_icm_crypt,
90	.decrypt = aes_icm_crypt,
91	.setkey = aes_icm_setkey,
92	.reinit = aes_gcm_reinit,
93	.encrypt_last = aes_icm_crypt_last,
94	.decrypt_last = aes_icm_crypt_last,
95};
96
97struct enc_xform enc_xform_ccm = {
98	.type = CRYPTO_AES_CCM_16,
99	.name = "AES-CCM",
100	.ctxsize = sizeof(struct aes_icm_ctx),
101	.blocksize = 1,
102	.native_blocksize = AES_BLOCK_LEN,
103	.ivsize = AES_CCM_IV_LEN,
104	.minkey = AES_MIN_KEY, .maxkey = AES_MAX_KEY,
105	.encrypt = aes_icm_crypt,
106	.decrypt = aes_icm_crypt,
107	.setkey = aes_icm_setkey,
108	.reinit = aes_ccm_reinit,
109	.encrypt_last = aes_icm_crypt_last,
110	.decrypt_last = aes_icm_crypt_last,
111};
112
113/*
114 * Encryption wrapper routines.
115 */
116static void
117aes_icm_reinit(void *key, const uint8_t *iv)
118{
119	struct aes_icm_ctx *ctx;
120
121	ctx = key;
122	bcopy(iv, ctx->ac_block, AESICM_BLOCKSIZE);
123}
124
125static void
126aes_gcm_reinit(void *key, const uint8_t *iv)
127{
128	struct aes_icm_ctx *ctx;
129
130	aes_icm_reinit(key, iv);
131
132	ctx = key;
133	/* GCM starts with 2 as counter 1 is used for final xor of tag. */
134	bzero(&ctx->ac_block[AESICM_BLOCKSIZE - 4], 4);
135	ctx->ac_block[AESICM_BLOCKSIZE - 1] = 2;
136}
137
138static void
139aes_ccm_reinit(void *key, const uint8_t *iv)
140{
141	struct aes_icm_ctx *ctx;
142
143	ctx = key;
144
145	/* CCM has flags, then the IV, then the counter, which starts at 1 */
146	bzero(ctx->ac_block, sizeof(ctx->ac_block));
147	/* 3 bytes for length field; this gives a nonce of 12 bytes */
148	ctx->ac_block[0] = (15 - AES_CCM_IV_LEN) - 1;
149	bcopy(iv, ctx->ac_block+1, AES_CCM_IV_LEN);
150	ctx->ac_block[AESICM_BLOCKSIZE - 1] = 1;
151}
152
153static void
154aes_icm_crypt(void *key, const uint8_t *in, uint8_t *out)
155{
156	struct aes_icm_ctx *ctx;
157	int i;
158
159	ctx = key;
160	aes_icm_crypt_last(key, in, out, AESICM_BLOCKSIZE);
161
162	/* increment counter */
163	for (i = AESICM_BLOCKSIZE - 1;
164	     i >= 0; i--)
165		if (++ctx->ac_block[i])   /* continue on overflow */
166			break;
167}
168
169static void
170aes_icm_crypt_last(void *key, const uint8_t *in, uint8_t *out, size_t len)
171{
172	struct aes_icm_ctx *ctx;
173	uint8_t keystream[AESICM_BLOCKSIZE];
174	int i;
175
176	ctx = key;
177	rijndaelEncrypt(ctx->ac_ek, ctx->ac_nr, ctx->ac_block, keystream);
178	for (i = 0; i < len; i++)
179		out[i] = in[i] ^ keystream[i];
180	explicit_bzero(keystream, sizeof(keystream));
181}
182
183static int
184aes_icm_setkey(void *sched, const uint8_t *key, int len)
185{
186	struct aes_icm_ctx *ctx;
187
188	if (len != 16 && len != 24 && len != 32)
189		return (EINVAL);
190
191	ctx = sched;
192	ctx->ac_nr = rijndaelKeySetupEnc(ctx->ac_ek, key, len * 8);
193	return (0);
194}
195