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Herbert Xudb131ef2006-09-21 11:44:08 +10001/*
2 * CBC: Cipher Block Chaining mode
3 *
Herbert Xucc868d82016-11-22 20:08:42 +08004 * Copyright (c) 2006-2016 Herbert Xu <herbert@gondor.apana.org.au>
Herbert Xudb131ef2006-09-21 11:44:08 +10005 *
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
Marcelo Cerrie6c2e652017-02-27 09:38:25 -030013#include <crypto/algapi.h>
Herbert Xucc868d82016-11-22 20:08:42 +080014#include <crypto/cbc.h>
Herbert Xu79c65d12016-11-22 20:08:39 +080015#include <crypto/internal/skcipher.h>
Herbert Xudb131ef2006-09-21 11:44:08 +100016#include <linux/err.h>
17#include <linux/init.h>
18#include <linux/kernel.h>
Herbert Xu50b65442007-11-20 17:36:00 +080019#include <linux/log2.h>
Herbert Xudb131ef2006-09-21 11:44:08 +100020#include <linux/module.h>
Herbert Xudb131ef2006-09-21 11:44:08 +100021#include <linux/slab.h>
22
23struct crypto_cbc_ctx {
24 struct crypto_cipher *child;
Herbert Xudb131ef2006-09-21 11:44:08 +100025};
26
Herbert Xu79c65d12016-11-22 20:08:39 +080027static int crypto_cbc_setkey(struct crypto_skcipher *parent, const u8 *key,
Herbert Xudb131ef2006-09-21 11:44:08 +100028 unsigned int keylen)
29{
Herbert Xu79c65d12016-11-22 20:08:39 +080030 struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(parent);
Herbert Xudb131ef2006-09-21 11:44:08 +100031 struct crypto_cipher *child = ctx->child;
32 int err;
33
34 crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
Herbert Xu79c65d12016-11-22 20:08:39 +080035 crypto_cipher_set_flags(child, crypto_skcipher_get_flags(parent) &
Herbert Xudb131ef2006-09-21 11:44:08 +100036 CRYPTO_TFM_REQ_MASK);
37 err = crypto_cipher_setkey(child, key, keylen);
Herbert Xu79c65d12016-11-22 20:08:39 +080038 crypto_skcipher_set_flags(parent, crypto_cipher_get_flags(child) &
39 CRYPTO_TFM_RES_MASK);
Herbert Xudb131ef2006-09-21 11:44:08 +100040 return err;
41}
42
Herbert Xu79c65d12016-11-22 20:08:39 +080043static inline void crypto_cbc_encrypt_one(struct crypto_skcipher *tfm,
44 const u8 *src, u8 *dst)
Herbert Xudb131ef2006-09-21 11:44:08 +100045{
Herbert Xu79c65d12016-11-22 20:08:39 +080046 struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
47
48 crypto_cipher_encrypt_one(ctx->child, dst, src);
49}
50
51static int crypto_cbc_encrypt(struct skcipher_request *req)
52{
53 return crypto_cbc_encrypt_walk(req, crypto_cbc_encrypt_one);
54}
55
Herbert Xu79c65d12016-11-22 20:08:39 +080056static inline void crypto_cbc_decrypt_one(struct crypto_skcipher *tfm,
57 const u8 *src, u8 *dst)
58{
59 struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
60
61 crypto_cipher_decrypt_one(ctx->child, dst, src);
62}
63
64static int crypto_cbc_decrypt(struct skcipher_request *req)
65{
66 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
67 struct skcipher_walk walk;
Herbert Xudb131ef2006-09-21 11:44:08 +100068 int err;
69
Herbert Xu79c65d12016-11-22 20:08:39 +080070 err = skcipher_walk_virt(&walk, req, false);
Herbert Xudb131ef2006-09-21 11:44:08 +100071
Herbert Xu79c65d12016-11-22 20:08:39 +080072 while (walk.nbytes) {
73 err = crypto_cbc_decrypt_blocks(&walk, tfm,
74 crypto_cbc_decrypt_one);
75 err = skcipher_walk_done(&walk, err);
Herbert Xudb131ef2006-09-21 11:44:08 +100076 }
77
78 return err;
79}
80
Herbert Xu79c65d12016-11-22 20:08:39 +080081static int crypto_cbc_init_tfm(struct crypto_skcipher *tfm)
Herbert Xudb131ef2006-09-21 11:44:08 +100082{
Herbert Xu79c65d12016-11-22 20:08:39 +080083 struct skcipher_instance *inst = skcipher_alg_instance(tfm);
84 struct crypto_spawn *spawn = skcipher_instance_ctx(inst);
85 struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
Herbert Xu2e306ee2006-12-17 10:05:58 +110086 struct crypto_cipher *cipher;
Herbert Xudb131ef2006-09-21 11:44:08 +100087
Herbert Xu2e306ee2006-12-17 10:05:58 +110088 cipher = crypto_spawn_cipher(spawn);
89 if (IS_ERR(cipher))
90 return PTR_ERR(cipher);
Herbert Xudb131ef2006-09-21 11:44:08 +100091
Herbert Xu2e306ee2006-12-17 10:05:58 +110092 ctx->child = cipher;
Herbert Xudb131ef2006-09-21 11:44:08 +100093 return 0;
94}
95
Herbert Xu79c65d12016-11-22 20:08:39 +080096static void crypto_cbc_exit_tfm(struct crypto_skcipher *tfm)
Herbert Xudb131ef2006-09-21 11:44:08 +100097{
Herbert Xu79c65d12016-11-22 20:08:39 +080098 struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
99
Herbert Xudb131ef2006-09-21 11:44:08 +1000100 crypto_free_cipher(ctx->child);
101}
102
Herbert Xu79c65d12016-11-22 20:08:39 +0800103static void crypto_cbc_free(struct skcipher_instance *inst)
Herbert Xudb131ef2006-09-21 11:44:08 +1000104{
Herbert Xu79c65d12016-11-22 20:08:39 +0800105 crypto_drop_skcipher(skcipher_instance_ctx(inst));
106 kfree(inst);
107}
108
109static int crypto_cbc_create(struct crypto_template *tmpl, struct rtattr **tb)
110{
111 struct skcipher_instance *inst;
Marcelo Cerrie6c2e652017-02-27 09:38:25 -0300112 struct crypto_attr_type *algt;
Herbert Xu79c65d12016-11-22 20:08:39 +0800113 struct crypto_spawn *spawn;
Herbert Xudb131ef2006-09-21 11:44:08 +1000114 struct crypto_alg *alg;
Marcelo Cerrie6c2e652017-02-27 09:38:25 -0300115 u32 mask;
Herbert Xuebc610e2007-01-01 18:37:02 +1100116 int err;
Herbert Xudb131ef2006-09-21 11:44:08 +1000117
Herbert Xu79c65d12016-11-22 20:08:39 +0800118 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER);
Herbert Xuebc610e2007-01-01 18:37:02 +1100119 if (err)
Herbert Xu79c65d12016-11-22 20:08:39 +0800120 return err;
121
122 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
123 if (!inst)
124 return -ENOMEM;
Herbert Xuebc610e2007-01-01 18:37:02 +1100125
Marcelo Cerrie6c2e652017-02-27 09:38:25 -0300126 algt = crypto_get_attr_type(tb);
127 err = PTR_ERR(algt);
128 if (IS_ERR(algt))
129 goto err_free_inst;
130
131 mask = CRYPTO_ALG_TYPE_MASK |
132 crypto_requires_off(algt->type, algt->mask,
133 CRYPTO_ALG_NEED_FALLBACK);
134
135 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, mask);
Herbert Xu79c65d12016-11-22 20:08:39 +0800136 err = PTR_ERR(alg);
Herbert Xudb131ef2006-09-21 11:44:08 +1000137 if (IS_ERR(alg))
Herbert Xu79c65d12016-11-22 20:08:39 +0800138 goto err_free_inst;
Herbert Xudb131ef2006-09-21 11:44:08 +1000139
Herbert Xu79c65d12016-11-22 20:08:39 +0800140 spawn = skcipher_instance_ctx(inst);
141 err = crypto_init_spawn(spawn, alg, skcipher_crypto_instance(inst),
142 CRYPTO_ALG_TYPE_MASK);
Herbert Xu79c65d12016-11-22 20:08:39 +0800143 if (err)
Pan Bian2f946052018-11-22 18:00:16 +0800144 goto err_put_alg;
Herbert Xu79c65d12016-11-22 20:08:39 +0800145
146 err = crypto_inst_setname(skcipher_crypto_instance(inst), "cbc", alg);
147 if (err)
148 goto err_drop_spawn;
149
150 err = -EINVAL;
Herbert Xu50b65442007-11-20 17:36:00 +0800151 if (!is_power_of_2(alg->cra_blocksize))
Herbert Xu79c65d12016-11-22 20:08:39 +0800152 goto err_drop_spawn;
Herbert Xu50b65442007-11-20 17:36:00 +0800153
Herbert Xu79c65d12016-11-22 20:08:39 +0800154 inst->alg.base.cra_priority = alg->cra_priority;
155 inst->alg.base.cra_blocksize = alg->cra_blocksize;
156 inst->alg.base.cra_alignmask = alg->cra_alignmask;
Herbert Xudb131ef2006-09-21 11:44:08 +1000157
Herbert Xu79c65d12016-11-22 20:08:39 +0800158 inst->alg.ivsize = alg->cra_blocksize;
159 inst->alg.min_keysize = alg->cra_cipher.cia_min_keysize;
160 inst->alg.max_keysize = alg->cra_cipher.cia_max_keysize;
Herbert Xudb131ef2006-09-21 11:44:08 +1000161
Herbert Xu79c65d12016-11-22 20:08:39 +0800162 inst->alg.base.cra_ctxsize = sizeof(struct crypto_cbc_ctx);
Herbert Xudb131ef2006-09-21 11:44:08 +1000163
Herbert Xu79c65d12016-11-22 20:08:39 +0800164 inst->alg.init = crypto_cbc_init_tfm;
165 inst->alg.exit = crypto_cbc_exit_tfm;
Herbert Xudb131ef2006-09-21 11:44:08 +1000166
Herbert Xu79c65d12016-11-22 20:08:39 +0800167 inst->alg.setkey = crypto_cbc_setkey;
168 inst->alg.encrypt = crypto_cbc_encrypt;
169 inst->alg.decrypt = crypto_cbc_decrypt;
Herbert Xudb131ef2006-09-21 11:44:08 +1000170
Herbert Xu79c65d12016-11-22 20:08:39 +0800171 inst->free = crypto_cbc_free;
Herbert Xudb131ef2006-09-21 11:44:08 +1000172
Herbert Xu79c65d12016-11-22 20:08:39 +0800173 err = skcipher_register_instance(tmpl, inst);
174 if (err)
175 goto err_drop_spawn;
Pan Bian2f946052018-11-22 18:00:16 +0800176 crypto_mod_put(alg);
Herbert Xu79c65d12016-11-22 20:08:39 +0800177
178out:
179 return err;
180
181err_drop_spawn:
182 crypto_drop_spawn(spawn);
Pan Bian2f946052018-11-22 18:00:16 +0800183err_put_alg:
184 crypto_mod_put(alg);
Herbert Xu79c65d12016-11-22 20:08:39 +0800185err_free_inst:
Herbert Xudb131ef2006-09-21 11:44:08 +1000186 kfree(inst);
Herbert Xu79c65d12016-11-22 20:08:39 +0800187 goto out;
Herbert Xudb131ef2006-09-21 11:44:08 +1000188}
189
190static struct crypto_template crypto_cbc_tmpl = {
191 .name = "cbc",
Herbert Xu79c65d12016-11-22 20:08:39 +0800192 .create = crypto_cbc_create,
Herbert Xudb131ef2006-09-21 11:44:08 +1000193 .module = THIS_MODULE,
194};
195
196static int __init crypto_cbc_module_init(void)
197{
198 return crypto_register_template(&crypto_cbc_tmpl);
199}
200
201static void __exit crypto_cbc_module_exit(void)
202{
203 crypto_unregister_template(&crypto_cbc_tmpl);
204}
205
206module_init(crypto_cbc_module_init);
207module_exit(crypto_cbc_module_exit);
208
209MODULE_LICENSE("GPL");
210MODULE_DESCRIPTION("CBC block cipher algorithm");
Kees Cook4943ba12014-11-24 16:32:38 -0800211MODULE_ALIAS_CRYPTO("cbc");