Gilad Ben-Yossef | 747c8ce | 2018-03-06 09:44:42 +0000 | [diff] [blame] | 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 | static const u32 fk[4] = { |
| 20 | 0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc |
| 21 | }; |
| 22 | |
| 23 | static const u8 sbox[256] = { |
| 24 | 0xd6, 0x90, 0xe9, 0xfe, 0xcc, 0xe1, 0x3d, 0xb7, |
| 25 | 0x16, 0xb6, 0x14, 0xc2, 0x28, 0xfb, 0x2c, 0x05, |
| 26 | 0x2b, 0x67, 0x9a, 0x76, 0x2a, 0xbe, 0x04, 0xc3, |
| 27 | 0xaa, 0x44, 0x13, 0x26, 0x49, 0x86, 0x06, 0x99, |
| 28 | 0x9c, 0x42, 0x50, 0xf4, 0x91, 0xef, 0x98, 0x7a, |
| 29 | 0x33, 0x54, 0x0b, 0x43, 0xed, 0xcf, 0xac, 0x62, |
| 30 | 0xe4, 0xb3, 0x1c, 0xa9, 0xc9, 0x08, 0xe8, 0x95, |
| 31 | 0x80, 0xdf, 0x94, 0xfa, 0x75, 0x8f, 0x3f, 0xa6, |
| 32 | 0x47, 0x07, 0xa7, 0xfc, 0xf3, 0x73, 0x17, 0xba, |
| 33 | 0x83, 0x59, 0x3c, 0x19, 0xe6, 0x85, 0x4f, 0xa8, |
| 34 | 0x68, 0x6b, 0x81, 0xb2, 0x71, 0x64, 0xda, 0x8b, |
| 35 | 0xf8, 0xeb, 0x0f, 0x4b, 0x70, 0x56, 0x9d, 0x35, |
| 36 | 0x1e, 0x24, 0x0e, 0x5e, 0x63, 0x58, 0xd1, 0xa2, |
| 37 | 0x25, 0x22, 0x7c, 0x3b, 0x01, 0x21, 0x78, 0x87, |
| 38 | 0xd4, 0x00, 0x46, 0x57, 0x9f, 0xd3, 0x27, 0x52, |
| 39 | 0x4c, 0x36, 0x02, 0xe7, 0xa0, 0xc4, 0xc8, 0x9e, |
| 40 | 0xea, 0xbf, 0x8a, 0xd2, 0x40, 0xc7, 0x38, 0xb5, |
| 41 | 0xa3, 0xf7, 0xf2, 0xce, 0xf9, 0x61, 0x15, 0xa1, |
| 42 | 0xe0, 0xae, 0x5d, 0xa4, 0x9b, 0x34, 0x1a, 0x55, |
| 43 | 0xad, 0x93, 0x32, 0x30, 0xf5, 0x8c, 0xb1, 0xe3, |
| 44 | 0x1d, 0xf6, 0xe2, 0x2e, 0x82, 0x66, 0xca, 0x60, |
| 45 | 0xc0, 0x29, 0x23, 0xab, 0x0d, 0x53, 0x4e, 0x6f, |
| 46 | 0xd5, 0xdb, 0x37, 0x45, 0xde, 0xfd, 0x8e, 0x2f, |
| 47 | 0x03, 0xff, 0x6a, 0x72, 0x6d, 0x6c, 0x5b, 0x51, |
| 48 | 0x8d, 0x1b, 0xaf, 0x92, 0xbb, 0xdd, 0xbc, 0x7f, |
| 49 | 0x11, 0xd9, 0x5c, 0x41, 0x1f, 0x10, 0x5a, 0xd8, |
| 50 | 0x0a, 0xc1, 0x31, 0x88, 0xa5, 0xcd, 0x7b, 0xbd, |
| 51 | 0x2d, 0x74, 0xd0, 0x12, 0xb8, 0xe5, 0xb4, 0xb0, |
| 52 | 0x89, 0x69, 0x97, 0x4a, 0x0c, 0x96, 0x77, 0x7e, |
| 53 | 0x65, 0xb9, 0xf1, 0x09, 0xc5, 0x6e, 0xc6, 0x84, |
| 54 | 0x18, 0xf0, 0x7d, 0xec, 0x3a, 0xdc, 0x4d, 0x20, |
| 55 | 0x79, 0xee, 0x5f, 0x3e, 0xd7, 0xcb, 0x39, 0x48 |
| 56 | }; |
| 57 | |
| 58 | static const u32 ck[] = { |
| 59 | 0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269, |
| 60 | 0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9, |
| 61 | 0xe0e7eef5, 0xfc030a11, 0x181f262d, 0x343b4249, |
| 62 | 0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9, |
| 63 | 0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229, |
| 64 | 0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299, |
| 65 | 0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209, |
| 66 | 0x10171e25, 0x2c333a41, 0x484f565d, 0x646b7279 |
| 67 | }; |
| 68 | |
| 69 | static u32 sm4_t_non_lin_sub(u32 x) |
| 70 | { |
| 71 | int i; |
| 72 | u8 *b = (u8 *)&x; |
| 73 | |
| 74 | for (i = 0; i < 4; ++i) |
| 75 | b[i] = sbox[b[i]]; |
| 76 | |
| 77 | return x; |
| 78 | } |
| 79 | |
| 80 | static u32 sm4_key_lin_sub(u32 x) |
| 81 | { |
| 82 | return x ^ rol32(x, 13) ^ rol32(x, 23); |
| 83 | |
| 84 | } |
| 85 | |
| 86 | static u32 sm4_enc_lin_sub(u32 x) |
| 87 | { |
| 88 | return x ^ rol32(x, 2) ^ rol32(x, 10) ^ rol32(x, 18) ^ rol32(x, 24); |
| 89 | } |
| 90 | |
| 91 | static u32 sm4_key_sub(u32 x) |
| 92 | { |
| 93 | return sm4_key_lin_sub(sm4_t_non_lin_sub(x)); |
| 94 | } |
| 95 | |
| 96 | static u32 sm4_enc_sub(u32 x) |
| 97 | { |
| 98 | return sm4_enc_lin_sub(sm4_t_non_lin_sub(x)); |
| 99 | } |
| 100 | |
| 101 | static u32 sm4_round(const u32 *x, const u32 rk) |
| 102 | { |
| 103 | return x[0] ^ sm4_enc_sub(x[1] ^ x[2] ^ x[3] ^ rk); |
| 104 | } |
| 105 | |
| 106 | |
| 107 | /** |
| 108 | * crypto_sm4_expand_key - Expands the SM4 key as described in GB/T 32907-2016 |
| 109 | * @ctx: The location where the computed key will be stored. |
| 110 | * @in_key: The supplied key. |
| 111 | * @key_len: The length of the supplied key. |
| 112 | * |
| 113 | * Returns 0 on success. The function fails only if an invalid key size (or |
| 114 | * pointer) is supplied. |
| 115 | */ |
| 116 | int crypto_sm4_expand_key(struct crypto_sm4_ctx *ctx, const u8 *in_key, |
| 117 | unsigned int key_len) |
| 118 | { |
| 119 | u32 rk[4], t; |
| 120 | const u32 *key = (u32 *)in_key; |
| 121 | int i; |
| 122 | |
| 123 | if (key_len != SM4_KEY_SIZE) |
| 124 | return -EINVAL; |
| 125 | |
| 126 | for (i = 0; i < 4; ++i) |
| 127 | rk[i] = get_unaligned_be32(&key[i]) ^ fk[i]; |
| 128 | |
| 129 | for (i = 0; i < 32; ++i) { |
| 130 | t = rk[0] ^ sm4_key_sub(rk[1] ^ rk[2] ^ rk[3] ^ ck[i]); |
| 131 | ctx->rkey_enc[i] = t; |
| 132 | rk[0] = rk[1]; |
| 133 | rk[1] = rk[2]; |
| 134 | rk[2] = rk[3]; |
| 135 | rk[3] = t; |
| 136 | } |
| 137 | |
| 138 | for (i = 0; i < 32; ++i) |
| 139 | ctx->rkey_dec[i] = ctx->rkey_enc[31 - i]; |
| 140 | |
| 141 | return 0; |
| 142 | } |
| 143 | EXPORT_SYMBOL_GPL(crypto_sm4_expand_key); |
| 144 | |
| 145 | /** |
| 146 | * crypto_sm4_set_key - Set the AES key. |
| 147 | * @tfm: The %crypto_tfm that is used in the context. |
| 148 | * @in_key: The input key. |
| 149 | * @key_len: The size of the key. |
| 150 | * |
| 151 | * Returns 0 on success, on failure the %CRYPTO_TFM_RES_BAD_KEY_LEN flag in tfm |
| 152 | * is set. The function uses crypto_sm4_expand_key() to expand the key. |
| 153 | * &crypto_sm4_ctx _must_ be the private data embedded in @tfm which is |
| 154 | * retrieved with crypto_tfm_ctx(). |
| 155 | */ |
| 156 | int crypto_sm4_set_key(struct crypto_tfm *tfm, const u8 *in_key, |
| 157 | unsigned int key_len) |
| 158 | { |
| 159 | struct crypto_sm4_ctx *ctx = crypto_tfm_ctx(tfm); |
| 160 | u32 *flags = &tfm->crt_flags; |
| 161 | int ret; |
| 162 | |
| 163 | ret = crypto_sm4_expand_key(ctx, in_key, key_len); |
| 164 | if (!ret) |
| 165 | return 0; |
| 166 | |
| 167 | *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; |
| 168 | return -EINVAL; |
| 169 | } |
| 170 | EXPORT_SYMBOL_GPL(crypto_sm4_set_key); |
| 171 | |
| 172 | static void sm4_do_crypt(const u32 *rk, u32 *out, const u32 *in) |
| 173 | { |
| 174 | u32 x[4], i, t; |
| 175 | |
| 176 | for (i = 0; i < 4; ++i) |
| 177 | x[i] = get_unaligned_be32(&in[i]); |
| 178 | |
| 179 | for (i = 0; i < 32; ++i) { |
| 180 | t = sm4_round(x, rk[i]); |
| 181 | x[0] = x[1]; |
| 182 | x[1] = x[2]; |
| 183 | x[2] = x[3]; |
| 184 | x[3] = t; |
| 185 | } |
| 186 | |
| 187 | for (i = 0; i < 4; ++i) |
| 188 | put_unaligned_be32(x[3 - i], &out[i]); |
| 189 | } |
| 190 | |
| 191 | /* encrypt a block of text */ |
| 192 | |
Ard Biesheuvel | 8da02bf | 2018-04-25 14:20:45 +0200 | [diff] [blame] | 193 | void crypto_sm4_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) |
Gilad Ben-Yossef | 747c8ce | 2018-03-06 09:44:42 +0000 | [diff] [blame] | 194 | { |
| 195 | const struct crypto_sm4_ctx *ctx = crypto_tfm_ctx(tfm); |
| 196 | |
| 197 | sm4_do_crypt(ctx->rkey_enc, (u32 *)out, (u32 *)in); |
| 198 | } |
Ard Biesheuvel | 8da02bf | 2018-04-25 14:20:45 +0200 | [diff] [blame] | 199 | EXPORT_SYMBOL_GPL(crypto_sm4_encrypt); |
Gilad Ben-Yossef | 747c8ce | 2018-03-06 09:44:42 +0000 | [diff] [blame] | 200 | |
| 201 | /* decrypt a block of text */ |
| 202 | |
Ard Biesheuvel | 8da02bf | 2018-04-25 14:20:45 +0200 | [diff] [blame] | 203 | void crypto_sm4_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) |
Gilad Ben-Yossef | 747c8ce | 2018-03-06 09:44:42 +0000 | [diff] [blame] | 204 | { |
| 205 | const struct crypto_sm4_ctx *ctx = crypto_tfm_ctx(tfm); |
| 206 | |
| 207 | sm4_do_crypt(ctx->rkey_dec, (u32 *)out, (u32 *)in); |
| 208 | } |
Ard Biesheuvel | 8da02bf | 2018-04-25 14:20:45 +0200 | [diff] [blame] | 209 | EXPORT_SYMBOL_GPL(crypto_sm4_decrypt); |
Gilad Ben-Yossef | 747c8ce | 2018-03-06 09:44:42 +0000 | [diff] [blame] | 210 | |
| 211 | static struct crypto_alg sm4_alg = { |
| 212 | .cra_name = "sm4", |
| 213 | .cra_driver_name = "sm4-generic", |
| 214 | .cra_priority = 100, |
| 215 | .cra_flags = CRYPTO_ALG_TYPE_CIPHER, |
| 216 | .cra_blocksize = SM4_BLOCK_SIZE, |
| 217 | .cra_ctxsize = sizeof(struct crypto_sm4_ctx), |
| 218 | .cra_module = THIS_MODULE, |
| 219 | .cra_u = { |
| 220 | .cipher = { |
| 221 | .cia_min_keysize = SM4_KEY_SIZE, |
| 222 | .cia_max_keysize = SM4_KEY_SIZE, |
| 223 | .cia_setkey = crypto_sm4_set_key, |
Ard Biesheuvel | 8da02bf | 2018-04-25 14:20:45 +0200 | [diff] [blame] | 224 | .cia_encrypt = crypto_sm4_encrypt, |
| 225 | .cia_decrypt = crypto_sm4_decrypt |
Gilad Ben-Yossef | 747c8ce | 2018-03-06 09:44:42 +0000 | [diff] [blame] | 226 | } |
| 227 | } |
| 228 | }; |
| 229 | |
| 230 | static int __init sm4_init(void) |
| 231 | { |
| 232 | return crypto_register_alg(&sm4_alg); |
| 233 | } |
| 234 | |
| 235 | static void __exit sm4_fini(void) |
| 236 | { |
| 237 | crypto_unregister_alg(&sm4_alg); |
| 238 | } |
| 239 | |
Eric Biggers | c4741b2 | 2019-04-11 21:57:42 -0700 | [diff] [blame] | 240 | subsys_initcall(sm4_init); |
Gilad Ben-Yossef | 747c8ce | 2018-03-06 09:44:42 +0000 | [diff] [blame] | 241 | module_exit(sm4_fini); |
| 242 | |
| 243 | MODULE_DESCRIPTION("SM4 Cipher Algorithm"); |
| 244 | MODULE_LICENSE("GPL v2"); |
| 245 | MODULE_ALIAS_CRYPTO("sm4"); |
| 246 | MODULE_ALIAS_CRYPTO("sm4-generic"); |