]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blame - crypto/cbc.c
Merge branch 'work.uaccess' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[mirror_ubuntu-bionic-kernel.git] / crypto / cbc.c
CommitLineData
db131ef9
HX
1/*
2 * CBC: Cipher Block Chaining mode
3 *
cc868d82 4 * Copyright (c) 2006-2016 Herbert Xu <herbert@gondor.apana.org.au>
db131ef9
HX
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
9 * any later version.
10 *
11 */
12
cc868d82 13#include <crypto/cbc.h>
79c65d17 14#include <crypto/internal/skcipher.h>
db131ef9
HX
15#include <linux/err.h>
16#include <linux/init.h>
17#include <linux/kernel.h>
50b6544e 18#include <linux/log2.h>
db131ef9 19#include <linux/module.h>
db131ef9
HX
20#include <linux/slab.h>
21
22struct crypto_cbc_ctx {
23 struct crypto_cipher *child;
db131ef9
HX
24};
25
79c65d17 26static int crypto_cbc_setkey(struct crypto_skcipher *parent, const u8 *key,
db131ef9
HX
27 unsigned int keylen)
28{
79c65d17 29 struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(parent);
db131ef9
HX
30 struct crypto_cipher *child = ctx->child;
31 int err;
32
33 crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
79c65d17 34 crypto_cipher_set_flags(child, crypto_skcipher_get_flags(parent) &
db131ef9
HX
35 CRYPTO_TFM_REQ_MASK);
36 err = crypto_cipher_setkey(child, key, keylen);
79c65d17
HX
37 crypto_skcipher_set_flags(parent, crypto_cipher_get_flags(child) &
38 CRYPTO_TFM_RES_MASK);
db131ef9
HX
39 return err;
40}
41
79c65d17
HX
42static inline void crypto_cbc_encrypt_one(struct crypto_skcipher *tfm,
43 const u8 *src, u8 *dst)
44{
45 struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
46
47 crypto_cipher_encrypt_one(ctx->child, dst, src);
48}
49
50static int crypto_cbc_encrypt(struct skcipher_request *req)
db131ef9 51{
79c65d17
HX
52 return crypto_cbc_encrypt_walk(req, crypto_cbc_encrypt_one);
53}
54
79c65d17
HX
55static inline void crypto_cbc_decrypt_one(struct crypto_skcipher *tfm,
56 const u8 *src, u8 *dst)
57{
58 struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
59
60 crypto_cipher_decrypt_one(ctx->child, dst, src);
61}
62
63static int crypto_cbc_decrypt(struct skcipher_request *req)
64{
65 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
66 struct skcipher_walk walk;
db131ef9
HX
67 int err;
68
79c65d17 69 err = skcipher_walk_virt(&walk, req, false);
db131ef9 70
79c65d17
HX
71 while (walk.nbytes) {
72 err = crypto_cbc_decrypt_blocks(&walk, tfm,
73 crypto_cbc_decrypt_one);
74 err = skcipher_walk_done(&walk, err);
db131ef9
HX
75 }
76
77 return err;
78}
79
79c65d17 80static int crypto_cbc_init_tfm(struct crypto_skcipher *tfm)
db131ef9 81{
79c65d17
HX
82 struct skcipher_instance *inst = skcipher_alg_instance(tfm);
83 struct crypto_spawn *spawn = skcipher_instance_ctx(inst);
84 struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
2e306ee0 85 struct crypto_cipher *cipher;
db131ef9 86
2e306ee0
HX
87 cipher = crypto_spawn_cipher(spawn);
88 if (IS_ERR(cipher))
89 return PTR_ERR(cipher);
db131ef9 90
2e306ee0 91 ctx->child = cipher;
db131ef9
HX
92 return 0;
93}
94
79c65d17 95static void crypto_cbc_exit_tfm(struct crypto_skcipher *tfm)
db131ef9 96{
79c65d17
HX
97 struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
98
db131ef9
HX
99 crypto_free_cipher(ctx->child);
100}
101
79c65d17 102static void crypto_cbc_free(struct skcipher_instance *inst)
db131ef9 103{
79c65d17
HX
104 crypto_drop_skcipher(skcipher_instance_ctx(inst));
105 kfree(inst);
106}
107
108static int crypto_cbc_create(struct crypto_template *tmpl, struct rtattr **tb)
109{
110 struct skcipher_instance *inst;
111 struct crypto_spawn *spawn;
db131ef9 112 struct crypto_alg *alg;
ebc610e5
HX
113 int err;
114
79c65d17 115 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER);
ebc610e5 116 if (err)
79c65d17
HX
117 return err;
118
119 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
120 if (!inst)
121 return -ENOMEM;
db131ef9 122
ebc610e5
HX
123 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
124 CRYPTO_ALG_TYPE_MASK);
79c65d17 125 err = PTR_ERR(alg);
db131ef9 126 if (IS_ERR(alg))
79c65d17 127 goto err_free_inst;
db131ef9 128
79c65d17
HX
129 spawn = skcipher_instance_ctx(inst);
130 err = crypto_init_spawn(spawn, alg, skcipher_crypto_instance(inst),
131 CRYPTO_ALG_TYPE_MASK);
132 crypto_mod_put(alg);
133 if (err)
134 goto err_free_inst;
135
136 err = crypto_inst_setname(skcipher_crypto_instance(inst), "cbc", alg);
137 if (err)
138 goto err_drop_spawn;
50b6544e 139
79c65d17
HX
140 err = -EINVAL;
141 if (!is_power_of_2(alg->cra_blocksize))
142 goto err_drop_spawn;
db131ef9 143
79c65d17
HX
144 inst->alg.base.cra_priority = alg->cra_priority;
145 inst->alg.base.cra_blocksize = alg->cra_blocksize;
146 inst->alg.base.cra_alignmask = alg->cra_alignmask;
db131ef9 147
79c65d17
HX
148 inst->alg.ivsize = alg->cra_blocksize;
149 inst->alg.min_keysize = alg->cra_cipher.cia_min_keysize;
150 inst->alg.max_keysize = alg->cra_cipher.cia_max_keysize;
db131ef9 151
79c65d17 152 inst->alg.base.cra_ctxsize = sizeof(struct crypto_cbc_ctx);
db131ef9 153
79c65d17
HX
154 inst->alg.init = crypto_cbc_init_tfm;
155 inst->alg.exit = crypto_cbc_exit_tfm;
db131ef9 156
79c65d17
HX
157 inst->alg.setkey = crypto_cbc_setkey;
158 inst->alg.encrypt = crypto_cbc_encrypt;
159 inst->alg.decrypt = crypto_cbc_decrypt;
db131ef9 160
79c65d17 161 inst->free = crypto_cbc_free;
db131ef9 162
79c65d17
HX
163 err = skcipher_register_instance(tmpl, inst);
164 if (err)
165 goto err_drop_spawn;
166
167out:
168 return err;
169
170err_drop_spawn:
171 crypto_drop_spawn(spawn);
172err_free_inst:
db131ef9 173 kfree(inst);
79c65d17 174 goto out;
db131ef9
HX
175}
176
177static struct crypto_template crypto_cbc_tmpl = {
178 .name = "cbc",
79c65d17 179 .create = crypto_cbc_create,
db131ef9
HX
180 .module = THIS_MODULE,
181};
182
183static int __init crypto_cbc_module_init(void)
184{
185 return crypto_register_template(&crypto_cbc_tmpl);
186}
187
188static void __exit crypto_cbc_module_exit(void)
189{
190 crypto_unregister_template(&crypto_cbc_tmpl);
191}
192
193module_init(crypto_cbc_module_init);
194module_exit(crypto_cbc_module_exit);
195
196MODULE_LICENSE("GPL");
197MODULE_DESCRIPTION("CBC block cipher algorithm");
4943ba16 198MODULE_ALIAS_CRYPTO("cbc");