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 SM4 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 * This function uses crypto_sm4_expand_key() to expand the key. 152 * &crypto_sm4_ctx _must_ be the private data embedded in @tfm which is 153 * retrieved with crypto_tfm_ctx(). 154 * 155 * Return: 0 on success; -EINVAL on failure (only happens for bad key lengths) 156 */ 157 int crypto_sm4_set_key(struct crypto_tfm *tfm, const u8 *in_key, 158 unsigned int key_len) 159 { 160 struct crypto_sm4_ctx *ctx = crypto_tfm_ctx(tfm); 161 162 return crypto_sm4_expand_key(ctx, in_key, key_len); 163 } 164 EXPORT_SYMBOL_GPL(crypto_sm4_set_key); 165 166 static void sm4_do_crypt(const u32 *rk, u32 *out, const u32 *in) 167 { 168 u32 x[4], i, t; 169 170 for (i = 0; i < 4; ++i) 171 x[i] = get_unaligned_be32(&in[i]); 172 173 for (i = 0; i < 32; ++i) { 174 t = sm4_round(x, rk[i]); 175 x[0] = x[1]; 176 x[1] = x[2]; 177 x[2] = x[3]; 178 x[3] = t; 179 } 180 181 for (i = 0; i < 4; ++i) 182 put_unaligned_be32(x[3 - i], &out[i]); 183 } 184 185 /* encrypt a block of text */ 186 187 void crypto_sm4_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) 188 { 189 const struct crypto_sm4_ctx *ctx = crypto_tfm_ctx(tfm); 190 191 sm4_do_crypt(ctx->rkey_enc, (u32 *)out, (u32 *)in); 192 } 193 EXPORT_SYMBOL_GPL(crypto_sm4_encrypt); 194 195 /* decrypt a block of text */ 196 197 void crypto_sm4_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) 198 { 199 const struct crypto_sm4_ctx *ctx = crypto_tfm_ctx(tfm); 200 201 sm4_do_crypt(ctx->rkey_dec, (u32 *)out, (u32 *)in); 202 } 203 EXPORT_SYMBOL_GPL(crypto_sm4_decrypt); 204 205 static struct crypto_alg sm4_alg = { 206 .cra_name = "sm4", 207 .cra_driver_name = "sm4-generic", 208 .cra_priority = 100, 209 .cra_flags = CRYPTO_ALG_TYPE_CIPHER, 210 .cra_blocksize = SM4_BLOCK_SIZE, 211 .cra_ctxsize = sizeof(struct crypto_sm4_ctx), 212 .cra_module = THIS_MODULE, 213 .cra_u = { 214 .cipher = { 215 .cia_min_keysize = SM4_KEY_SIZE, 216 .cia_max_keysize = SM4_KEY_SIZE, 217 .cia_setkey = crypto_sm4_set_key, 218 .cia_encrypt = crypto_sm4_encrypt, 219 .cia_decrypt = crypto_sm4_decrypt 220 } 221 } 222 }; 223 224 static int __init sm4_init(void) 225 { 226 return crypto_register_alg(&sm4_alg); 227 } 228 229 static void __exit sm4_fini(void) 230 { 231 crypto_unregister_alg(&sm4_alg); 232 } 233 234 subsys_initcall(sm4_init); 235 module_exit(sm4_fini); 236 237 MODULE_DESCRIPTION("SM4 Cipher Algorithm"); 238 MODULE_LICENSE("GPL v2"); 239 MODULE_ALIAS_CRYPTO("sm4"); 240 MODULE_ALIAS_CRYPTO("sm4-generic"); 241