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 */
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
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
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
76 static int __init sm4_init(void)
77 {
78 return crypto_register_alg(&sm4_alg);
79 }
80
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
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