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/sm4.h>
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/types.h>
14 #include <linux/errno.h>
15 #include <linux/crypto.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  */
sm4_setkey(struct crypto_tfm * tfm,const u8 * in_key,unsigned int key_len)31 static 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 
sm4_encrypt(struct crypto_tfm * tfm,u8 * out,const u8 * in)41 static 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 
sm4_decrypt(struct crypto_tfm * tfm,u8 * out,const u8 * in)50 static 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 
57 static 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 
sm4_init(void)76 static int __init sm4_init(void)
77 {
78 	return crypto_register_alg(&sm4_alg);
79 }
80 
sm4_fini(void)81 static void __exit sm4_fini(void)
82 {
83 	crypto_unregister_alg(&sm4_alg);
84 }
85 
86 subsys_initcall(sm4_init);
87 module_exit(sm4_fini);
88 
89 MODULE_DESCRIPTION("SM4 Cipher Algorithm");
90 MODULE_LICENSE("GPL v2");
91 MODULE_ALIAS_CRYPTO("sm4");
92 MODULE_ALIAS_CRYPTO("sm4-generic");
93