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(rk: 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(rk: 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(alg: &sm4_alg);
79}
80
81static void __exit sm4_fini(void)
82{
83 crypto_unregister_alg(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

source code of linux/crypto/sm4_generic.c