Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * CBC: Cipher Block Chaining mode
4 *
5 * Copyright (c) 2006-2016 Herbert Xu <herbert@gondor.apana.org.au>
6 */
7
8#include <crypto/algapi.h>
9#include <crypto/cbc.h>
10#include <crypto/internal/skcipher.h>
11#include <linux/err.h>
12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/log2.h>
15#include <linux/module.h>
16
17static inline void crypto_cbc_encrypt_one(struct crypto_skcipher *tfm,
18 const u8 *src, u8 *dst)
19{
20 crypto_cipher_encrypt_one(skcipher_cipher_simple(tfm), dst, src);
21}
22
23static int crypto_cbc_encrypt(struct skcipher_request *req)
24{
25 return crypto_cbc_encrypt_walk(req, crypto_cbc_encrypt_one);
26}
27
28static inline void crypto_cbc_decrypt_one(struct crypto_skcipher *tfm,
29 const u8 *src, u8 *dst)
30{
31 crypto_cipher_decrypt_one(skcipher_cipher_simple(tfm), dst, src);
32}
33
34static int crypto_cbc_decrypt(struct skcipher_request *req)
35{
36 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
37 struct skcipher_walk walk;
38 int err;
39
40 err = skcipher_walk_virt(&walk, req, false);
41
42 while (walk.nbytes) {
43 err = crypto_cbc_decrypt_blocks(&walk, tfm,
44 crypto_cbc_decrypt_one);
45 err = skcipher_walk_done(&walk, err);
46 }
47
48 return err;
49}
50
51static int crypto_cbc_create(struct crypto_template *tmpl, struct rtattr **tb)
52{
53 struct skcipher_instance *inst;
54 struct crypto_alg *alg;
55 int err;
56
57 inst = skcipher_alloc_instance_simple(tmpl, tb, &alg);
58 if (IS_ERR(inst))
59 return PTR_ERR(inst);
60
61 err = -EINVAL;
62 if (!is_power_of_2(alg->cra_blocksize))
63 goto out_free_inst;
64
65 inst->alg.encrypt = crypto_cbc_encrypt;
66 inst->alg.decrypt = crypto_cbc_decrypt;
67
68 err = skcipher_register_instance(tmpl, inst);
69 if (err)
70 goto out_free_inst;
71 goto out_put_alg;
72
73out_free_inst:
74 inst->free(inst);
75out_put_alg:
76 crypto_mod_put(alg);
77 return err;
78}
79
80static struct crypto_template crypto_cbc_tmpl = {
81 .name = "cbc",
82 .create = crypto_cbc_create,
83 .module = THIS_MODULE,
84};
85
86static int __init crypto_cbc_module_init(void)
87{
88 return crypto_register_template(&crypto_cbc_tmpl);
89}
90
91static void __exit crypto_cbc_module_exit(void)
92{
93 crypto_unregister_template(&crypto_cbc_tmpl);
94}
95
96subsys_initcall(crypto_cbc_module_init);
97module_exit(crypto_cbc_module_exit);
98
99MODULE_LICENSE("GPL");
100MODULE_DESCRIPTION("CBC block cipher mode of operation");
101MODULE_ALIAS_CRYPTO("cbc");