crypto/sm4.c

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * SM4, as specified in
   4  * https://tools.ietf.org/id/draft-ribose-cfrg-sm4-10.html
   5  *
   6  * Copyright (C) 2018 ARM Limited or its affiliates.
   7  * Copyright (c) 2021 Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/unaligned.h>
  12 #include <crypto/sm4.h>
  13
  14 static const u32 ____cacheline_aligned fk[4] = {
  15         0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc
  16 };
  17
  18 static const u32 ____cacheline_aligned ck[32] = {
  19         0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269,
  20         0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9,
  21         0xe0e7eef5, 0xfc030a11, 0x181f262d, 0x343b4249,
  22         0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9,
  23         0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229,
  24         0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299,
  25         0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209,
  26         0x10171e25, 0x2c333a41, 0x484f565d, 0x646b7279
  27 };
  28
  29 static const u8 ____cacheline_aligned sbox[256] = {
  30         0xd6, 0x90, 0xe9, 0xfe, 0xcc, 0xe1, 0x3d, 0xb7,
  31         0x16, 0xb6, 0x14, 0xc2, 0x28, 0xfb, 0x2c, 0x05,
  32         0x2b, 0x67, 0x9a, 0x76, 0x2a, 0xbe, 0x04, 0xc3,
  33         0xaa, 0x44, 0x13, 0x26, 0x49, 0x86, 0x06, 0x99,
  34         0x9c, 0x42, 0x50, 0xf4, 0x91, 0xef, 0x98, 0x7a,
  35         0x33, 0x54, 0x0b, 0x43, 0xed, 0xcf, 0xac, 0x62,
  36         0xe4, 0xb3, 0x1c, 0xa9, 0xc9, 0x08, 0xe8, 0x95,
  37         0x80, 0xdf, 0x94, 0xfa, 0x75, 0x8f, 0x3f, 0xa6,
  38         0x47, 0x07, 0xa7, 0xfc, 0xf3, 0x73, 0x17, 0xba,
  39         0x83, 0x59, 0x3c, 0x19, 0xe6, 0x85, 0x4f, 0xa8,
  40         0x68, 0x6b, 0x81, 0xb2, 0x71, 0x64, 0xda, 0x8b,
  41         0xf8, 0xeb, 0x0f, 0x4b, 0x70, 0x56, 0x9d, 0x35,
  42         0x1e, 0x24, 0x0e, 0x5e, 0x63, 0x58, 0xd1, 0xa2,
  43         0x25, 0x22, 0x7c, 0x3b, 0x01, 0x21, 0x78, 0x87,
  44         0xd4, 0x00, 0x46, 0x57, 0x9f, 0xd3, 0x27, 0x52,
  45         0x4c, 0x36, 0x02, 0xe7, 0xa0, 0xc4, 0xc8, 0x9e,
  46         0xea, 0xbf, 0x8a, 0xd2, 0x40, 0xc7, 0x38, 0xb5,
  47         0xa3, 0xf7, 0xf2, 0xce, 0xf9, 0x61, 0x15, 0xa1,
  48         0xe0, 0xae, 0x5d, 0xa4, 0x9b, 0x34, 0x1a, 0x55,
  49         0xad, 0x93, 0x32, 0x30, 0xf5, 0x8c, 0xb1, 0xe3,
  50         0x1d, 0xf6, 0xe2, 0x2e, 0x82, 0x66, 0xca, 0x60,
  51         0xc0, 0x29, 0x23, 0xab, 0x0d, 0x53, 0x4e, 0x6f,
  52         0xd5, 0xdb, 0x37, 0x45, 0xde, 0xfd, 0x8e, 0x2f,
  53         0x03, 0xff, 0x6a, 0x72, 0x6d, 0x6c, 0x5b, 0x51,
  54         0x8d, 0x1b, 0xaf, 0x92, 0xbb, 0xdd, 0xbc, 0x7f,
  55         0x11, 0xd9, 0x5c, 0x41, 0x1f, 0x10, 0x5a, 0xd8,
  56         0x0a, 0xc1, 0x31, 0x88, 0xa5, 0xcd, 0x7b, 0xbd,
  57         0x2d, 0x74, 0xd0, 0x12, 0xb8, 0xe5, 0xb4, 0xb0,
  58         0x89, 0x69, 0x97, 0x4a, 0x0c, 0x96, 0x77, 0x7e,
  59         0x65, 0xb9, 0xf1, 0x09, 0xc5, 0x6e, 0xc6, 0x84,
  60         0x18, 0xf0, 0x7d, 0xec, 0x3a, 0xdc, 0x4d, 0x20,
  61         0x79, 0xee, 0x5f, 0x3e, 0xd7, 0xcb, 0x39, 0x48
  62 };
  63
  64 extern const u32 crypto_sm4_fk[4] __alias(fk);
  65 extern const u32 crypto_sm4_ck[32] __alias(ck);
  66 extern const u8 crypto_sm4_sbox[256] __alias(sbox);
  67
  68 EXPORT_SYMBOL(crypto_sm4_fk);
  69 EXPORT_SYMBOL(crypto_sm4_ck);
  70 EXPORT_SYMBOL(crypto_sm4_sbox);
  71
  72 static inline u32 sm4_t_non_lin_sub(u32 x)
  73 {
  74         u32 out;
  75
  76         out  = (u32)sbox[x & 0xff];
  77         out |= (u32)sbox[(x >> 8) & 0xff] << 8;
  78         out |= (u32)sbox[(x >> 16) & 0xff] << 16;
  79         out |= (u32)sbox[(x >> 24) & 0xff] << 24;
  80
  81         return out;
  82 }
  83
  84 static inline u32 sm4_key_lin_sub(u32 x)
  85 {
  86         return x ^ rol32(x, 13) ^ rol32(x, 23);
  87 }
  88
  89 static inline u32 sm4_enc_lin_sub(u32 x)
  90 {
  91         return x ^ rol32(x, 2) ^ rol32(x, 10) ^ rol32(x, 18) ^ rol32(x, 24);
  92 }
  93
  94 static inline u32 sm4_key_sub(u32 x)
  95 {
  96         return sm4_key_lin_sub(sm4_t_non_lin_sub(x));
  97 }
  98
  99 static inline u32 sm4_enc_sub(u32 x)
 100 {
 101         return sm4_enc_lin_sub(sm4_t_non_lin_sub(x));
 102 }
 103
 104 static inline u32 sm4_round(u32 x0, u32 x1, u32 x2, u32 x3, u32 rk)
 105 {
 106         return x0 ^ sm4_enc_sub(x1 ^ x2 ^ x3 ^ rk);
 107 }
 108
 109
 110 /**
 111  * sm4_expandkey - Expands the SM4 key as described in GB/T 32907-2016
 112  * @ctx:        The location where the computed key will be stored.
 113  * @in_key:     The supplied key.
 114  * @key_len:    The length of the supplied key.
 115  *
 116  * Returns 0 on success. The function fails only if an invalid key size (or
 117  * pointer) is supplied.
 118  */
 119 int sm4_expandkey(struct sm4_ctx *ctx, const u8 *in_key,
 120                           unsigned int key_len)
 121 {
 122         u32 rk[4];
 123         const u32 *key = (u32 *)in_key;
 124         int i;
 125
 126         if (key_len != SM4_KEY_SIZE)
 127                 return -EINVAL;
 128
 129         rk[0] = get_unaligned_be32(&key[0]) ^ fk[0];
 130         rk[1] = get_unaligned_be32(&key[1]) ^ fk[1];
 131         rk[2] = get_unaligned_be32(&key[2]) ^ fk[2];
 132         rk[3] = get_unaligned_be32(&key[3]) ^ fk[3];
 133
 134         for (i = 0; i < 32; i += 4) {
 135                 rk[0] ^= sm4_key_sub(rk[1] ^ rk[2] ^ rk[3] ^ ck[i + 0]);
 136                 rk[1] ^= sm4_key_sub(rk[2] ^ rk[3] ^ rk[0] ^ ck[i + 1]);
 137                 rk[2] ^= sm4_key_sub(rk[3] ^ rk[0] ^ rk[1] ^ ck[i + 2]);
 138                 rk[3] ^= sm4_key_sub(rk[0] ^ rk[1] ^ rk[2] ^ ck[i + 3]);
 139
 140                 ctx->rkey_enc[i + 0] = rk[0];
 141                 ctx->rkey_enc[i + 1] = rk[1];
 142                 ctx->rkey_enc[i + 2] = rk[2];
 143                 ctx->rkey_enc[i + 3] = rk[3];
 144                 ctx->rkey_dec[31 - 0 - i] = rk[0];
 145                 ctx->rkey_dec[31 - 1 - i] = rk[1];
 146                 ctx->rkey_dec[31 - 2 - i] = rk[2];
 147                 ctx->rkey_dec[31 - 3 - i] = rk[3];
 148         }
 149
 150         return 0;
 151 }
 152 EXPORT_SYMBOL_GPL(sm4_expandkey);
 153
 154 /**
 155  * sm4_crypt_block - Encrypt or decrypt a single SM4 block
 156  * @rk:         The rkey_enc for encrypt or rkey_dec for decrypt
 157  * @out:        Buffer to store output data
 158  * @in:         Buffer containing the input data
 159  */
 160 void sm4_crypt_block(const u32 *rk, u8 *out, const u8 *in)
 161 {
 162         u32 x[4], i;
 163
 164         x[0] = get_unaligned_be32(in + 0 * 4);
 165         x[1] = get_unaligned_be32(in + 1 * 4);
 166         x[2] = get_unaligned_be32(in + 2 * 4);
 167         x[3] = get_unaligned_be32(in + 3 * 4);
 168
 169         for (i = 0; i < 32; i += 4) {
 170                 x[0] = sm4_round(x[0], x[1], x[2], x[3], rk[i + 0]);
 171                 x[1] = sm4_round(x[1], x[2], x[3], x[0], rk[i + 1]);
 172                 x[2] = sm4_round(x[2], x[3], x[0], x[1], rk[i + 2]);
 173                 x[3] = sm4_round(x[3], x[0], x[1], x[2], rk[i + 3]);
 174         }
 175
 176         put_unaligned_be32(x[3 - 0], out + 0 * 4);
 177         put_unaligned_be32(x[3 - 1], out + 1 * 4);
 178         put_unaligned_be32(x[3 - 2], out + 2 * 4);
 179         put_unaligned_be32(x[3 - 3], out + 3 * 4);
 180 }
 181 EXPORT_SYMBOL_GPL(sm4_crypt_block);
 182
 183 MODULE_DESCRIPTION("Generic SM4 library");
 184 MODULE_LICENSE("GPL v2");