aboutsummaryrefslogtreecommitdiff
path: root/crypto/sm4.c
blob: 2c44193bc27e4a0369a795ed641a6e32ca33cb6b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * SM4, as specified in
 * https://tools.ietf.org/id/draft-ribose-cfrg-sm4-10.html
 *
 * Copyright (C) 2018 ARM Limited or its affiliates.
 * Copyright (c) 2021 Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
 */

#include <linux/module.h>
#include <asm/unaligned.h>
#include <crypto/sm4.h>

static const u32 ____cacheline_aligned fk[4] = {
	0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc
};

static const u32 ____cacheline_aligned ck[32] = {
	0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269,
	0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9,
	0xe0e7eef5, 0xfc030a11, 0x181f262d, 0x343b4249,
	0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9,
	0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229,
	0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299,
	0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209,
	0x10171e25, 0x2c333a41, 0x484f565d, 0x646b7279
};

static const u8 ____cacheline_aligned sbox[256] = {
	0xd6, 0x90, 0xe9, 0xfe, 0xcc, 0xe1, 0x3d, 0xb7,
	0x16, 0xb6, 0x14, 0xc2, 0x28, 0xfb, 0x2c, 0x05,
	0x2b, 0x67, 0x9a, 0x76, 0x2a, 0xbe, 0x04, 0xc3,
	0xaa, 0x44, 0x13, 0x26, 0x49, 0x86, 0x06, 0x99,
	0x9c, 0x42, 0x50, 0xf4, 0x91, 0xef, 0x98, 0x7a,
	0x33, 0x54, 0x0b, 0x43, 0xed, 0xcf, 0xac, 0x62,
	0xe4, 0xb3, 0x1c, 0xa9, 0xc9, 0x08, 0xe8, 0x95,
	0x80, 0xdf, 0x94, 0xfa, 0x75, 0x8f, 0x3f, 0xa6,
	0x47, 0x07, 0xa7, 0xfc, 0xf3, 0x73, 0x17, 0xba,
	0x83, 0x59, 0x3c, 0x19, 0xe6, 0x85, 0x4f, 0xa8,
	0x68, 0x6b, 0x81, 0xb2, 0x71, 0x64, 0xda, 0x8b,
	0xf8, 0xeb, 0x0f, 0x4b, 0x70, 0x56, 0x9d, 0x35,
	0x1e, 0x24, 0x0e, 0x5e, 0x63, 0x58, 0xd1, 0xa2,
	0x25, 0x22, 0x7c, 0x3b, 0x01, 0x21, 0x78, 0x87,
	0xd4, 0x00, 0x46, 0x57, 0x9f, 0xd3, 0x27, 0x52,
	0x4c, 0x36, 0x02, 0xe7, 0xa0, 0xc4, 0xc8, 0x9e,
	0xea, 0xbf, 0x8a, 0xd2, 0x40, 0xc7, 0x38, 0xb5,
	0xa3, 0xf7, 0xf2, 0xce, 0xf9, 0x61, 0x15, 0xa1,
	0xe0, 0xae, 0x5d, 0xa4, 0x9b, 0x34, 0x1a, 0x55,
	0xad, 0x93, 0x32, 0x30, 0xf5, 0x8c, 0xb1, 0xe3,
	0x1d, 0xf6, 0xe2, 0x2e, 0x82, 0x66, 0xca, 0x60,
	0xc0, 0x29, 0x23, 0xab, 0x0d, 0x53, 0x4e, 0x6f,
	0xd5, 0xdb, 0x37, 0x45, 0xde, 0xfd, 0x8e, 0x2f,
	0x03, 0xff, 0x6a, 0x72, 0x6d, 0x6c, 0x5b, 0x51,
	0x8d, 0x1b, 0xaf, 0x92, 0xbb, 0xdd, 0xbc, 0x7f,
	0x11, 0xd9, 0x5c, 0x41, 0x1f, 0x10, 0x5a, 0xd8,
	0x0a, 0xc1, 0x31, 0x88, 0xa5, 0xcd, 0x7b, 0xbd,
	0x2d, 0x74, 0xd0, 0x12, 0xb8, 0xe5, 0xb4, 0xb0,
	0x89, 0x69, 0x97, 0x4a, 0x0c, 0x96, 0x77, 0x7e,
	0x65, 0xb9, 0xf1, 0x09, 0xc5, 0x6e, 0xc6, 0x84,
	0x18, 0xf0, 0x7d, 0xec, 0x3a, 0xdc, 0x4d, 0x20,
	0x79, 0xee, 0x5f, 0x3e, 0xd7, 0xcb, 0x39, 0x48
};

extern const u32 crypto_sm4_fk[4] __alias(fk);
extern const u32 crypto_sm4_ck[32] __alias(ck);
extern const u8 crypto_sm4_sbox[256] __alias(sbox);

EXPORT_SYMBOL(crypto_sm4_fk);
EXPORT_SYMBOL(crypto_sm4_ck);
EXPORT_SYMBOL(crypto_sm4_sbox);

static inline u32 sm4_t_non_lin_sub(u32 x)
{
	u32 out;

	out  = (u32)sbox[x & 0xff];
	out |= (u32)sbox[(x >> 8) & 0xff] << 8;
	out |= (u32)sbox[(x >> 16) & 0xff] << 16;
	out |= (u32)sbox[(x >> 24) & 0xff] << 24;

	return out;
}

static inline u32 sm4_key_lin_sub(u32 x)
{
	return x ^ rol32(x, 13) ^ rol32(x, 23);
}

static inline u32 sm4_enc_lin_sub(u32 x)
{
	return x ^ rol32(x, 2) ^ rol32(x, 10) ^ rol32(x, 18) ^ rol32(x, 24);
}

static inline u32 sm4_key_sub(u32 x)
{
	return sm4_key_lin_sub(sm4_t_non_lin_sub(x));
}

static inline u32 sm4_enc_sub(u32 x)
{
	return sm4_enc_lin_sub(sm4_t_non_lin_sub(x));
}

static inline u32 sm4_round(u32 x0, u32 x1, u32 x2, u32 x3, u32 rk)
{
	return x0 ^ sm4_enc_sub(x1 ^ x2 ^ x3 ^ rk);
}


/**
 * sm4_expandkey - Expands the SM4 key as described in GB/T 32907-2016
 * @ctx:	The location where the computed key will be stored.
 * @in_key:	The supplied key.
 * @key_len:	The length of the supplied key.
 *
 * Returns 0 on success. The function fails only if an invalid key size (or
 * pointer) is supplied.
 */
int sm4_expandkey(struct sm4_ctx *ctx, const u8 *in_key,
			  unsigned int key_len)
{
	u32 rk[4];
	const u32 *key = (u32 *)in_key;
	int i;

	if (key_len != SM4_KEY_SIZE)
		return -EINVAL;

	rk[0] = get_unaligned_be32(&key[0]) ^ fk[0];
	rk[1] = get_unaligned_be32(&key[1]) ^ fk[1];
	rk[2] = get_unaligned_be32(&key[2]) ^ fk[2];
	rk[3] = get_unaligned_be32(&key[3]) ^ fk[3];

	for (i = 0; i < 32; i += 4) {
		rk[0] ^= sm4_key_sub(rk[1] ^ rk[2] ^ rk[3] ^ ck[i + 0]);
		rk[1] ^= sm4_key_sub(rk[2] ^ rk[3] ^ rk[0] ^ ck[i + 1]);
		rk[2] ^= sm4_key_sub(rk[3] ^ rk[0] ^ rk[1] ^ ck[i + 2]);
		rk[3] ^= sm4_key_sub(rk[0] ^ rk[1] ^ rk[2] ^ ck[i + 3]);

		ctx->rkey_enc[i + 0] = rk[0];
		ctx->rkey_enc[i + 1] = rk[1];
		ctx->rkey_enc[i + 2] = rk[2];
		ctx->rkey_enc[i + 3] = rk[3];
		ctx->rkey_dec[31 - 0 - i] = rk[0];
		ctx->rkey_dec[31 - 1 - i] = rk[1];
		ctx->rkey_dec[31 - 2 - i] = rk[2];
		ctx->rkey_dec[31 - 3 - i] = rk[3];
	}

	return 0;
}
EXPORT_SYMBOL_GPL(sm4_expandkey);

/**
 * sm4_crypt_block - Encrypt or decrypt a single SM4 block
 * @rk:		The rkey_enc for encrypt or rkey_dec for decrypt
 * @out:	Buffer to store output data
 * @in: 	Buffer containing the input data
 */
void sm4_crypt_block(const u32 *rk, u8 *out, const u8 *in)
{
	u32 x[4], i;

	x[0] = get_unaligned_be32(in + 0 * 4);
	x[1] = get_unaligned_be32(in + 1 * 4);
	x[2] = get_unaligned_be32(in + 2 * 4);
	x[3] = get_unaligned_be32(in + 3 * 4);

	for (i = 0; i < 32; i += 4) {
		x[0] = sm4_round(x[0], x[1], x[2], x[3], rk[i + 0]);
		x[1] = sm4_round(x[1], x[2], x[3], x[0], rk[i + 1]);
		x[2] = sm4_round(x[2], x[3], x[0], x[1], rk[i + 2]);
		x[3] = sm4_round(x[3], x[0], x[1], x[2], rk[i + 3]);
	}

	put_unaligned_be32(x[3 - 0], out + 0 * 4);
	put_unaligned_be32(x[3 - 1], out + 1 * 4);
	put_unaligned_be32(x[3 - 2], out + 2 * 4);
	put_unaligned_be32(x[3 - 3], out + 3 * 4);
}
EXPORT_SYMBOL_GPL(sm4_crypt_block);

MODULE_DESCRIPTION("Generic SM4 library");
MODULE_LICENSE("GPL v2");