/* ====================================================================
 * Copyright (c) 2014 - 2019 The GmSSL Project.  All rights reserved.
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 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the GmSSL Project.
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 *    guanzhi1980@gmail.com.
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 * 5. Products derived from this software may not be called "GmSSL"
 *    nor may "GmSSL" appear in their names without prior written
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 *    "This product includes software developed by the GmSSL Project
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 * ====================================================================
 */

#include "sms4_lcl.h"
#include <sm4.h>
#include <stdint.h>

static uint FK[4] = {
	0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc,
};

static uint 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,
};


#define L32_(x)					\
	((x) ^ 					\
	ROL32((x), 13) ^			\
	ROL32((x), 23))

#define ENC_ROUND(x0, x1, x2, x3, x4, i)	\
	x4 = x1 ^ x2 ^ x3 ^ *(CK + i);		\
	x4 = S32(x4);				\
	x4 = x0 ^ L32_(x4);			\
	*(rk + i) = x4

#define DEC_ROUND(x0, x1, x2, x3, x4, i)	\
	x4 = x1 ^ x2 ^ x3 ^ *(CK + i);		\
	x4 = S32(x4);				\
	x4 = x0 ^ L32_(x4);			\
	*(rk + 31 - i) = x4

void sms4_set_encrypt_key(sms4_key_t *key, const unsigned char user_key[16])
{
	uint *rk = key->rk;
	uint x0, x1, x2, x3, x4;

	x0 = GETU32(user_key) ^ FK[0];
	x1 = GETU32(user_key + 4) ^ FK[1];
	x2 = GETU32(user_key + 8) ^ FK[2];
	x3 = GETU32(user_key + 12) ^ FK[3];

#define ROUND ENC_ROUND
	ROUNDS(x0, x1, x2, x3, x4);
#undef ROUND

	x0 = x1 = x2 = x3 = x4 = 0;
}

void sms4_set_decrypt_key(sms4_key_t *key, const unsigned char user_key[16])
{
	uint *rk = key->rk;
	uint x0, x1, x2, x3, x4;

	x0 = GETU32(user_key) ^ FK[0];
	x1 = GETU32(user_key + 4) ^ FK[1];
	x2 = GETU32(user_key + 8) ^ FK[2];
	x3 = GETU32(user_key + 12) ^ FK[3];

#define ROUND DEC_ROUND
	ROUNDS(x0, x1, x2, x3, x4);
#undef ROUND

	x0 = x1 = x2 = x3 = x4 = 0;
}