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Diffstat (limited to 'sm4.c')
-rw-r--r-- | sm4.c | 223 |
1 files changed, 223 insertions, 0 deletions
@@ -0,0 +1,223 @@ +/* sm4.c + + Copyright (C) 2022 Tianjia Zhang <tianjia.zhang@linux.alibaba.com> + + This file is part of GNU Nettle. + + GNU Nettle is free software: you can redistribute it and/or + modify it under the terms of either: + + * the GNU Lesser General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at your + option) any later version. + + or + + * the GNU General Public License as published by the Free + Software Foundation; either version 2 of the License, or (at your + option) any later version. + + or both in parallel, as here. + + GNU Nettle is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received copies of the GNU General Public License and + the GNU Lesser General Public License along with this program. If + not, see http://www.gnu.org/licenses/. +*/ + +#if HAVE_CONFIG_H +# include "config.h" +#endif + +#include <assert.h> +#include <string.h> + +#include "sm4.h" + +#include "macros.h" + + +static const uint32_t fk[4] = +{ + 0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc +}; + +static const uint32_t 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 uint8_t 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 +}; + +static uint32_t +sm4_t_non_lin_sub(uint32_t x) +{ + uint32_t out; + + out = (uint32_t)sbox[x & 0xff]; + out |= (uint32_t)sbox[(x >> 8) & 0xff] << 8; + out |= (uint32_t)sbox[(x >> 16) & 0xff] << 16; + out |= (uint32_t)sbox[(x >> 24) & 0xff] << 24; + + return out; +} + +static uint32_t +sm4_key_lin_sub(uint32_t x) +{ + return x ^ ROTL32(13, x) ^ ROTL32(23, x); +} + +static uint32_t +sm4_enc_lin_sub(uint32_t x) +{ + return x ^ ROTL32(2, x) ^ ROTL32(10, x) ^ ROTL32(18, x) ^ ROTL32(24, x); +} + +static uint32_t +sm4_key_sub(uint32_t x) +{ + return sm4_key_lin_sub(sm4_t_non_lin_sub(x)); +} + +static uint32_t +sm4_enc_sub(uint32_t x) +{ + return sm4_enc_lin_sub(sm4_t_non_lin_sub(x)); +} + +static uint32_t +sm4_round(uint32_t x0, uint32_t x1, uint32_t x2, uint32_t x3, uint32_t rk) +{ + return x0 ^ sm4_enc_sub(x1 ^ x2 ^ x3 ^ rk); +} + +static void +sm4_set_key(struct sm4_ctx *ctx, const uint8_t *key, int encrypt) +{ + uint32_t rk0, rk1, rk2, rk3; + unsigned i; + + rk0 = READ_UINT32(key + 0) ^ fk[0]; + rk1 = READ_UINT32(key + 4) ^ fk[1]; + rk2 = READ_UINT32(key + 8) ^ fk[2]; + rk3 = READ_UINT32(key + 12) ^ fk[3]; + + for (i = 0; i < 32; i += 4) + { + rk0 ^= sm4_key_sub(rk1 ^ rk2 ^ rk3 ^ ck[i + 0]); + rk1 ^= sm4_key_sub(rk2 ^ rk3 ^ rk0 ^ ck[i + 1]); + rk2 ^= sm4_key_sub(rk3 ^ rk0 ^ rk1 ^ ck[i + 2]); + rk3 ^= sm4_key_sub(rk0 ^ rk1 ^ rk2 ^ ck[i + 3]); + + if (encrypt) + { + ctx->rkey[i + 0] = rk0; + ctx->rkey[i + 1] = rk1; + ctx->rkey[i + 2] = rk2; + ctx->rkey[i + 3] = rk3; + } + else + { + ctx->rkey[31 - 0 - i] = rk0; + ctx->rkey[31 - 1 - i] = rk1; + ctx->rkey[31 - 2 - i] = rk2; + ctx->rkey[31 - 3 - i] = rk3; + } + } +} + +void +sm4_set_encrypt_key(struct sm4_ctx *ctx, const uint8_t *key) +{ + sm4_set_key(ctx, key, 1); +} + +void +sm4_set_decrypt_key(struct sm4_ctx *ctx, const uint8_t *key) +{ + sm4_set_key(ctx, key, 0); +} + +void +sm4_crypt(const struct sm4_ctx *context, + size_t length, + uint8_t *dst, + const uint8_t *src) +{ + const uint32_t *rk = context->rkey; + + assert( !(length % SM4_BLOCK_SIZE) ); + + for ( ; length; length -= SM4_BLOCK_SIZE) + { + uint32_t x0, x1, x2, x3; + unsigned i; + + x0 = READ_UINT32(src + 0 * 4); + x1 = READ_UINT32(src + 1 * 4); + x2 = READ_UINT32(src + 2 * 4); + x3 = READ_UINT32(src + 3 * 4); + + for (i = 0; i < 32; i += 4) + { + x0 = sm4_round(x0, x1, x2, x3, rk[i + 0]); + x1 = sm4_round(x1, x2, x3, x0, rk[i + 1]); + x2 = sm4_round(x2, x3, x0, x1, rk[i + 2]); + x3 = sm4_round(x3, x0, x1, x2, rk[i + 3]); + } + + WRITE_UINT32(dst + 0 * 4, x3); + WRITE_UINT32(dst + 1 * 4, x2); + WRITE_UINT32(dst + 2 * 4, x1); + WRITE_UINT32(dst + 3 * 4, x0); + + src += SM4_BLOCK_SIZE; + dst += SM4_BLOCK_SIZE; + } +} |