xref: /kernel/linux/linux-5.10/crypto/ecb.c (revision 8c2ecf20) 
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/skcipher.h>
10#include <linux/err.h>
11#include <linux/init.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14
15static int crypto_ecb_crypt(struct skcipher_request *req,
16			    struct crypto_cipher *cipher,
17			    void (*fn)(struct crypto_tfm *, u8 *, const u8 *))
18{
19	const unsigned int bsize = crypto_cipher_blocksize(cipher);
20	struct skcipher_walk walk;
21	unsigned int nbytes;
22	int err;
23
24	err = skcipher_walk_virt(&walk, req, false);
25
26	while ((nbytes = walk.nbytes) != 0) {
27		const u8 *src = walk.src.virt.addr;
28		u8 *dst = walk.dst.virt.addr;
29
30		do {
31			fn(crypto_cipher_tfm(cipher), dst, src);
32
33			src += bsize;
34			dst += bsize;
35		} while ((nbytes -= bsize) >= bsize);
36
37		err = skcipher_walk_done(&walk, nbytes);
38	}
39
40	return err;
41}
42
43static int crypto_ecb_encrypt(struct skcipher_request *req)
44{
45	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
46	struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
47
48	return crypto_ecb_crypt(req, cipher,
49				crypto_cipher_alg(cipher)->cia_encrypt);
50}
51
52static int crypto_ecb_decrypt(struct skcipher_request *req)
53{
54	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
55	struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
56
57	return crypto_ecb_crypt(req, cipher,
58				crypto_cipher_alg(cipher)->cia_decrypt);
59}
60
61static int crypto_ecb_create(struct crypto_template *tmpl, struct rtattr **tb)
62{
63	struct skcipher_instance *inst;
64	int err;
65
66	inst = skcipher_alloc_instance_simple(tmpl, tb);
67	if (IS_ERR(inst))
68		return PTR_ERR(inst);
69
70	inst->alg.ivsize = 0; /* ECB mode doesn't take an IV */
71
72	inst->alg.encrypt = crypto_ecb_encrypt;
73	inst->alg.decrypt = crypto_ecb_decrypt;
74
75	err = skcipher_register_instance(tmpl, inst);
76	if (err)
77		inst->free(inst);
78
79	return err;
80}
81
82static struct crypto_template crypto_ecb_tmpl = {
83	.name = "ecb",
84	.create = crypto_ecb_create,
85	.module = THIS_MODULE,
86};
87
88static int __init crypto_ecb_module_init(void)
89{
90	return crypto_register_template(&crypto_ecb_tmpl);
91}
92
93static void __exit crypto_ecb_module_exit(void)
94{
95	crypto_unregister_template(&crypto_ecb_tmpl);
96}
97
98subsys_initcall(crypto_ecb_module_init);
99module_exit(crypto_ecb_module_exit);
100
101MODULE_LICENSE("GPL");
102MODULE_DESCRIPTION("ECB block cipher mode of operation");
103MODULE_ALIAS_CRYPTO("ecb");
104