xref: /kernel/linux/linux-6.6/crypto/ecb.c (revision 62306a36) 
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ECB: Electronic CodeBook mode
4 *
5 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
6 */
7
8#include <crypto/algapi.h>
9#include <crypto/internal/cipher.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/module.h>
15
16static int crypto_ecb_crypt(struct skcipher_request *req,
17			    struct crypto_cipher *cipher,
18			    void (*fn)(struct crypto_tfm *, u8 *, const u8 *))
19{
20	const unsigned int bsize = crypto_cipher_blocksize(cipher);
21	struct skcipher_walk walk;
22	unsigned int nbytes;
23	int err;
24
25	err = skcipher_walk_virt(&walk, req, false);
26
27	while ((nbytes = walk.nbytes) != 0) {
28		const u8 *src = walk.src.virt.addr;
29		u8 *dst = walk.dst.virt.addr;
30
31		do {
32			fn(crypto_cipher_tfm(cipher), dst, src);
33
34			src += bsize;
35			dst += bsize;
36		} while ((nbytes -= bsize) >= bsize);
37
38		err = skcipher_walk_done(&walk, nbytes);
39	}
40
41	return err;
42}
43
44static int crypto_ecb_encrypt(struct skcipher_request *req)
45{
46	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
47	struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
48
49	return crypto_ecb_crypt(req, cipher,
50				crypto_cipher_alg(cipher)->cia_encrypt);
51}
52
53static int crypto_ecb_decrypt(struct skcipher_request *req)
54{
55	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
56	struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
57
58	return crypto_ecb_crypt(req, cipher,
59				crypto_cipher_alg(cipher)->cia_decrypt);
60}
61
62static int crypto_ecb_create(struct crypto_template *tmpl, struct rtattr **tb)
63{
64	struct skcipher_instance *inst;
65	int err;
66
67	inst = skcipher_alloc_instance_simple(tmpl, tb);
68	if (IS_ERR(inst))
69		return PTR_ERR(inst);
70
71	inst->alg.ivsize = 0; /* ECB mode doesn't take an IV */
72
73	inst->alg.encrypt = crypto_ecb_encrypt;
74	inst->alg.decrypt = crypto_ecb_decrypt;
75
76	err = skcipher_register_instance(tmpl, inst);
77	if (err)
78		inst->free(inst);
79
80	return err;
81}
82
83static struct crypto_template crypto_ecb_tmpl = {
84	.name = "ecb",
85	.create = crypto_ecb_create,
86	.module = THIS_MODULE,
87};
88
89static int __init crypto_ecb_module_init(void)
90{
91	return crypto_register_template(&crypto_ecb_tmpl);
92}
93
94static void __exit crypto_ecb_module_exit(void)
95{
96	crypto_unregister_template(&crypto_ecb_tmpl);
97}
98
99subsys_initcall(crypto_ecb_module_init);
100module_exit(crypto_ecb_module_exit);
101
102MODULE_LICENSE("GPL");
103MODULE_DESCRIPTION("ECB block cipher mode of operation");
104MODULE_ALIAS_CRYPTO("ecb");
105