1// SPDX-License-Identifier: GPL-2.0
2
3/*
4 * SM4 Cipher Algorithm.
5 *
6 * Copyright (C) 2018 ARM Limited or its affiliates.
7 * All rights reserved.
8 */
9
10#include <crypto/algapi.h>
11#include <crypto/sm4.h>
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/types.h>
15#include <linux/errno.h>
16#include <asm/byteorder.h>
17#include <asm/unaligned.h>
18
19/**
20 * sm4_setkey - Set the SM4 key.
21 * @tfm:	The %crypto_tfm that is used in the context.
22 * @in_key:	The input key.
23 * @key_len:	The size of the key.
24 *
25 * This function uses sm4_expandkey() to expand the key.
26 * &sm4_ctx _must_ be the private data embedded in @tfm which is
27 * retrieved with crypto_tfm_ctx().
28 *
29 * Return: 0 on success; -EINVAL on failure (only happens for bad key lengths)
30 */
31static int sm4_setkey(struct crypto_tfm *tfm, const u8 *in_key,
32		       unsigned int key_len)
33{
34	struct sm4_ctx *ctx = crypto_tfm_ctx(tfm);
35
36	return sm4_expandkey(ctx, in_key, key_len);
37}
38
39/* encrypt a block of text */
40
41static void sm4_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
42{
43	const struct sm4_ctx *ctx = crypto_tfm_ctx(tfm);
44
45	sm4_crypt_block(ctx->rkey_enc, out, in);
46}
47
48/* decrypt a block of text */
49
50static void sm4_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
51{
52	const struct sm4_ctx *ctx = crypto_tfm_ctx(tfm);
53
54	sm4_crypt_block(ctx->rkey_dec, out, in);
55}
56
57static struct crypto_alg sm4_alg = {
58	.cra_name		=	"sm4",
59	.cra_driver_name	=	"sm4-generic",
60	.cra_priority		=	100,
61	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
62	.cra_blocksize		=	SM4_BLOCK_SIZE,
63	.cra_ctxsize		=	sizeof(struct sm4_ctx),
64	.cra_module		=	THIS_MODULE,
65	.cra_u			=	{
66		.cipher = {
67			.cia_min_keysize	=	SM4_KEY_SIZE,
68			.cia_max_keysize	=	SM4_KEY_SIZE,
69			.cia_setkey		=	sm4_setkey,
70			.cia_encrypt		=	sm4_encrypt,
71			.cia_decrypt		=	sm4_decrypt
72		}
73	}
74};
75
76static int __init sm4_init(void)
77{
78	return crypto_register_alg(&sm4_alg);
79}
80
81static void __exit sm4_fini(void)
82{
83	crypto_unregister_alg(&sm4_alg);
84}
85
86subsys_initcall(sm4_init);
87module_exit(sm4_fini);
88
89MODULE_DESCRIPTION("SM4 Cipher Algorithm");
90MODULE_LICENSE("GPL v2");
91MODULE_ALIAS_CRYPTO("sm4");
92MODULE_ALIAS_CRYPTO("sm4-generic");
93