2 * AES CBC routines supporting VMX instructions on the Power 8
4 * Copyright (C) 2015 International Business Machines Inc.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 only.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 * Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com>
22 #include <linux/types.h>
23 #include <linux/err.h>
24 #include <linux/crypto.h>
25 #include <linux/delay.h>
27 #include <asm/switch_to.h>
28 #include <crypto/aes.h>
29 #include <crypto/internal/simd.h>
30 #include <crypto/scatterwalk.h>
31 #include <crypto/skcipher.h>
33 #include "aesp8-ppc.h"
35 struct p8_aes_cbc_ctx {
36 struct crypto_sync_skcipher *fallback;
37 struct aes_key enc_key;
38 struct aes_key dec_key;
41 static int p8_aes_cbc_init(struct crypto_tfm *tfm)
43 const char *alg = crypto_tfm_alg_name(tfm);
44 struct crypto_sync_skcipher *fallback;
45 struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
47 fallback = crypto_alloc_sync_skcipher(alg, 0,
48 CRYPTO_ALG_NEED_FALLBACK);
50 if (IS_ERR(fallback)) {
52 "Failed to allocate transformation for '%s': %ld\n",
53 alg, PTR_ERR(fallback));
54 return PTR_ERR(fallback);
57 crypto_sync_skcipher_set_flags(
59 crypto_skcipher_get_flags((struct crypto_skcipher *)tfm));
60 ctx->fallback = fallback;
65 static void p8_aes_cbc_exit(struct crypto_tfm *tfm)
67 struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
70 crypto_free_sync_skcipher(ctx->fallback);
75 static int p8_aes_cbc_setkey(struct crypto_tfm *tfm, const u8 *key,
79 struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
84 ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
85 ret |= aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
90 ret |= crypto_sync_skcipher_setkey(ctx->fallback, key, keylen);
92 return ret ? -EINVAL : 0;
95 static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
96 struct scatterlist *dst,
97 struct scatterlist *src, unsigned int nbytes)
100 struct blkcipher_walk walk;
101 struct p8_aes_cbc_ctx *ctx =
102 crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));
104 if (!crypto_simd_usable()) {
105 SYNC_SKCIPHER_REQUEST_ON_STACK(req, ctx->fallback);
106 skcipher_request_set_sync_tfm(req, ctx->fallback);
107 skcipher_request_set_callback(req, desc->flags, NULL, NULL);
108 skcipher_request_set_crypt(req, src, dst, nbytes, desc->info);
109 ret = crypto_skcipher_encrypt(req);
110 skcipher_request_zero(req);
112 blkcipher_walk_init(&walk, dst, src, nbytes);
113 ret = blkcipher_walk_virt(desc, &walk);
114 while ((nbytes = walk.nbytes)) {
118 aes_p8_cbc_encrypt(walk.src.virt.addr,
120 nbytes & AES_BLOCK_MASK,
121 &ctx->enc_key, walk.iv, 1);
122 disable_kernel_vsx();
126 nbytes &= AES_BLOCK_SIZE - 1;
127 ret = blkcipher_walk_done(desc, &walk, nbytes);
134 static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
135 struct scatterlist *dst,
136 struct scatterlist *src, unsigned int nbytes)
139 struct blkcipher_walk walk;
140 struct p8_aes_cbc_ctx *ctx =
141 crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));
143 if (!crypto_simd_usable()) {
144 SYNC_SKCIPHER_REQUEST_ON_STACK(req, ctx->fallback);
145 skcipher_request_set_sync_tfm(req, ctx->fallback);
146 skcipher_request_set_callback(req, desc->flags, NULL, NULL);
147 skcipher_request_set_crypt(req, src, dst, nbytes, desc->info);
148 ret = crypto_skcipher_decrypt(req);
149 skcipher_request_zero(req);
151 blkcipher_walk_init(&walk, dst, src, nbytes);
152 ret = blkcipher_walk_virt(desc, &walk);
153 while ((nbytes = walk.nbytes)) {
157 aes_p8_cbc_encrypt(walk.src.virt.addr,
159 nbytes & AES_BLOCK_MASK,
160 &ctx->dec_key, walk.iv, 0);
161 disable_kernel_vsx();
165 nbytes &= AES_BLOCK_SIZE - 1;
166 ret = blkcipher_walk_done(desc, &walk, nbytes);
174 struct crypto_alg p8_aes_cbc_alg = {
175 .cra_name = "cbc(aes)",
176 .cra_driver_name = "p8_aes_cbc",
177 .cra_module = THIS_MODULE,
178 .cra_priority = 2000,
179 .cra_type = &crypto_blkcipher_type,
180 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | CRYPTO_ALG_NEED_FALLBACK,
182 .cra_blocksize = AES_BLOCK_SIZE,
183 .cra_ctxsize = sizeof(struct p8_aes_cbc_ctx),
184 .cra_init = p8_aes_cbc_init,
185 .cra_exit = p8_aes_cbc_exit,
187 .ivsize = AES_BLOCK_SIZE,
188 .min_keysize = AES_MIN_KEY_SIZE,
189 .max_keysize = AES_MAX_KEY_SIZE,
190 .setkey = p8_aes_cbc_setkey,
191 .encrypt = p8_aes_cbc_encrypt,
192 .decrypt = p8_aes_cbc_decrypt,