#include "HGDes.h"
#include "HGInc.h"

/* 初始置换表IP */
static HGByte IP_Table[64] =
{
	57, 49, 41, 33, 25, 17, 9, 1,
	59, 51, 43, 35, 27, 19, 11, 3,
	61, 53, 45, 37, 29, 21, 13, 5,
	63, 55, 47, 39, 31, 23, 15, 7,
	56, 48, 40, 32, 24, 16, 8, 0,
	58, 50, 42, 34, 26, 18, 10, 2,
	60, 52, 44, 36, 28, 20, 12, 4,
	62, 54, 46, 38, 30, 22, 14, 6
};

/* 逆初始置换表IP^-1 */
static HGByte IP_1_Table[64] =
{
	39, 7, 47, 15, 55, 23, 63, 31,
	38, 6, 46, 14, 54, 22, 62, 30,
	37, 5, 45, 13, 53, 21, 61, 29,
	36, 4, 44, 12, 52, 20, 60, 28,
	35, 3, 43, 11, 51, 19, 59, 27,
	34, 2, 42, 10, 50, 18, 58, 26,
	33, 1, 41, 9, 49, 17, 57, 25,
	32, 0, 40, 8, 48, 16, 56, 24
};

/* 扩充置换表E */
static HGByte E_Table[48] =
{
	31, 0, 1, 2, 3, 4,
	3, 4, 5, 6, 7, 8,
	7, 8, 9,10, 11, 12,
	11, 12, 13, 14, 15, 16,
	15, 16, 17, 18, 19, 20,
	19, 20, 21, 22, 23, 24,
	23, 24, 25, 26, 27, 28,
	27, 28, 29, 30, 31, 0
};

/* 置换函数P */
static HGByte P_Table[32] =
{
	15, 6, 19, 20, 28, 11, 27, 16,
	0, 14, 22, 25, 4, 17, 30, 9,
	1, 7, 23, 13, 31, 26, 2, 8,
	18, 12, 29, 5, 21, 10, 3, 24
};

/* S盒 */
static HGByte S[8][4][16] =
{
	/* S1 */
	14,4,13,1,2,15,11,8,3,10,6,12,5,9,0,7,
	0,15,7,4,14,2,13,1,10,6,12,11,9,5,3,8,
	4,1,14,8,13,6,2,11,15,12,9,7,3,10,5,0,
	15,12,8,2,4,9,1,7,5,11,3,14,10,0,6,13,

	/* S2 */
	15,1,8,14,6,11,3,4,9,7,2,13,12,0,5,10,
	3,13,4,7,15,2,8,14,12,0,1,10,6,9,11,5,
	0,14,7,11,10,4,13,1,5,8,12,6,9,3,2,15,
	13,8,10,1,3,15,4,2,11,6,7,12,0,5,14,9,

	/* S3 */
	10,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8,
	13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1,
	13,6,4,9,8,15,3,0,11,1,2,12,5,10,14,7,
	1,10,13,0,6,9,8,7,4,15,14,3,11,5,2,12,

	/* S4 */
	7,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15,
	13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9,
	10,6,9,0,12,11,7,13,15,1,3,14,5,2,8,4,
	3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14,

	/* S5 */
	2,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9,
	14,11,2,12,4,7,13,1,5,0,15,10,3,9,8,6,
	4,2,1,11,10,13,7,8,15,9,12,5,6,3,0,14,
	11,8,12,7,1,14,2,13,6,15,0,9,10,4,5,3,

	/* S6 */
	12,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11,
	10,15,4,2,7,12,9,5,6,1,13,14,0,11,3,8,
	9,14,15,5,2,8,12,3,7,0,4,10,1,13,11,6,
	4,3,2,12,9,5,15,10,11,14,1,7,6,0,8,13,

	/* S7 */
	4,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1,
	13,0,11,7,4,9,1,10,14,3,5,12,2,15,8,6,
	1,4,11,13,12,3,7,14,10,15,6,8,0,5,9,2,
	6,11,13,8,1,4,10,7,9,5,0,15,14,2,3,12,

	/* S8 */
	13,2,8,4,6,15,11,1,10,9,3,14,5,0,12,7,
	1,15,13,8,10,3,7,4,12,5,6,11,0,14,9,2,
	7,11,4,1,9,12,14,2,0,6,10,13,15,3,5,8,
	2,1,14,7,4,10,8,13,15,12,9,0,3,5,6,11
};

/* 置换选择1 */
static HGByte PC_1[56] =
{
	56,48,40,32,24,16,8,
	0,57,49,41,33,25,17,
	9,1,58,50,42,34,26,
	18,10,2,59,51,43,35,
	62,54,46,38,30,22,14,
	6,61,53,45,37,29,21,
	13,5,60,52,44,36,28,
	20,12,4,27,19,11,3
};

/* 置换选择2 */
static HGByte PC_2[48] =
{
	13,16,10,23,0,4,2,27,
	14,5,20,9,22,18,11,3,
	25,7,15,6,26,19,12,1,
	40,51,30,36,46,54,29,39,
	50,44,32,46,43,48,38,55,
	33,52,45,41,49,35,28,31
};

/* 对左移次数的规定 */
static HGByte MOVE_TIMES[16] = { 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1 };


static int ByteToBit8(HGByte ch, HGByte bit[8])
{
	for (int cnt = 0; cnt < 8; cnt++)
	{
		*(bit + cnt) = (ch >> cnt) & 1;
	}

	return 0;
}

static int Bit8ToByte(const HGByte bit[8], HGByte* ch)
{
	if (NULL == ch)
		return -1;

	*ch = 0;
	for (int cnt = 0; cnt < 8; cnt++)
	{
		*ch |= *(bit + cnt) << cnt;
	}

	return 0;
}

static int Byte8ToBit64(const HGByte ch[8], HGByte bit[64])
{
	for (int cnt = 0; cnt < 8; cnt++)
	{
		ByteToBit8(*(ch + cnt), bit + (cnt << 3));
	}

	return 0;
}

static int Bit64ToByte8(HGByte bit[64], HGByte ch[8])
{
	memset(ch, 0, 8);
	for (int cnt = 0; cnt < 8; cnt++)
	{
		Bit8ToByte(bit + (cnt << 3), ch + cnt);
	}

	return 0;
}

/* 密钥置换1 */
static int DES_PC1_Transform(HGByte key[64], HGByte tempbts[56])
{
	for (int cnt = 0; cnt < 56; cnt++)
	{
		tempbts[cnt] = key[PC_1[cnt]];
	}

	return 0;
}

/* 密钥置换2 */
static int DES_PC2_Transform(HGByte key[56], HGByte tempbts[48])
{
	for (int cnt = 0; cnt < 48; cnt++)
	{
		tempbts[cnt] = key[PC_2[cnt]];
	}

	return 0;
}

/* 循环左移 */
static int DES_ROL(HGByte data[56], int time)
{
	HGByte temp[56];
	HGByte temp2[28];

	/* 保存将要循环移动到右边的位 */
	memcpy(temp, data, time);
	memcpy(temp + time, data + 28, time);

	/* 前28位移动 */
	//memcpy(data, data + time, 28 - time);
	memcpy(temp2, data + time, 28 - time);
	memcpy(data, temp2, 28 - time);
	memcpy(data + 28 - time, temp, time);

	/* 后28位移动 */
	//memcpy(data + 28, data + 28 + time, 28 - time);
	memcpy(temp2, data + 28 + time, 28 - time);
	memcpy(data + 28, temp2, 28 - time);
	memcpy(data + 56 - time, temp + time, time);

	return 0;
}

/* 生成子密钥 */
static int DES_MakeSubKeys(HGByte key[64], HGByte subKeys[16][48])
{
	HGByte temp[56];
	DES_PC1_Transform(key, temp); /* PC1置换 */

	for (int cnt = 0; cnt < 16; cnt++)
	{
		/* 16轮跌代，产生16个子密钥 */
		DES_ROL(temp, MOVE_TIMES[cnt]); /* 循环左移 */
		DES_PC2_Transform(temp, subKeys[cnt]); /* PC2置换，产生子密钥 */
	}

	return 0;
}

/* IP置换 */
static int DES_IP_Transform(HGByte data[64])
{
	HGByte temp[64];
	for (int cnt = 0; cnt < 64; cnt++)
	{
		temp[cnt] = data[IP_Table[cnt]];
	}

	memcpy(data, temp, 64);
	return 0;
}

/* IP逆置换 */
static int DES_IP_1_Transform(HGByte data[64])
{
	HGByte temp[64];
	for (int cnt = 0; cnt < 64; cnt++)
	{
		temp[cnt] = data[IP_1_Table[cnt]];
	}

	memcpy(data, temp, 64);
	return 0;
}

/* 扩展置换 */
static int DES_E_Transform(HGByte data[48])
{
	HGByte temp[48];
	for (int cnt = 0; cnt < 48; cnt++)
	{
		temp[cnt] = data[E_Table[cnt]];
	}

	memcpy(data, temp, 48);
	return 0;
}

/* P置换 */
static int DES_P_Transform(HGByte data[32])
{
	HGByte temp[32];
	for (int cnt = 0; cnt < 32; cnt++)
	{
		temp[cnt] = data[P_Table[cnt]];
	}

	memcpy(data, temp, 32);
	return 0;
}

/* 异或 */
static int DES_XOR(HGByte R[48], HGByte L[48], int count)
{
	for (int cnt = 0; cnt < count; cnt++)
	{
		R[cnt] ^= L[cnt];
	}

	return 0;
}

/* S盒置换 */
static int DES_SBOX(HGByte data[48])
{
	for (int cnt = 0; cnt < 8; cnt++)
	{
		int cur1 = cnt * 6;
		int cur2 = cnt << 2;

		/* 计算在S盒中的行与列 */
		int line = (data[cur1] << 1) + data[cur1 + 5];
		int row = (data[cur1 + 1] << 3) + (data[cur1 + 2] << 2) + (data[cur1 + 3] << 1) + data[cur1 + 4];
		int output = S[cnt][line][row];

		/* 化为2进制 */
		data[cur2] = (output & 0X08) >> 3;
		data[cur2 + 1] = (output & 0X04) >> 2;
		data[cur2 + 2] = (output & 0X02) >> 1;
		data[cur2 + 3] = output & 0x01;
	}

	return 0;
}

/* 交换 */
static int DES_Swap(HGByte left[32], HGByte right[32])
{
	HGByte temp[32];
	memcpy(temp, left, 32);
	memcpy(left, right, 32);
	memcpy(right, temp, 32);

	return 0;
}

/* 加密单个分组 */
static int DES_EncryptBlock(HGByte plainBlock[8], HGByte subKeys[16][48], HGByte cipherBlock[8])
{
	HGByte plainBits[64];
	HGByte copyRight[48];

	Byte8ToBit64(plainBlock, plainBits);
	/* 初始置换（IP置换） */
	DES_IP_Transform(plainBits);

	/* 16轮迭代 */
	for (int cnt = 0; cnt < 16; cnt++)
	{
		memcpy(copyRight, plainBits + 32, 32);

		/* 将右半部分进行扩展置换，从32位扩展到48位 */
		DES_E_Transform(copyRight);
		/* 将右半部分与子密钥进行异或操作 */
		DES_XOR(copyRight, subKeys[cnt], 48);
		/* 异或结果进入S盒，输出32位结果 */
		DES_SBOX(copyRight);
		/* P置换 */
		DES_P_Transform(copyRight);
		/* 将明文左半部分与右半部分进行异或 */
		DES_XOR(plainBits, copyRight, 32);

		if (cnt != 15)
		{
			/* 最终完成左右部的交换 */
			DES_Swap(plainBits, plainBits + 32);
		}
	}

	/* 逆初始置换（IP^1置换） */
	DES_IP_1_Transform(plainBits);
	Bit64ToByte8(plainBits, cipherBlock);
	return 0;
}


/* 解密单个分组 */

static int DES_DecryptBlock(HGByte cipherBlock[8], HGByte subKeys[16][48], HGByte plainBlock[8])
{
	HGByte cipherBits[64];
	HGByte copyRight[48];

	Byte8ToBit64(cipherBlock, cipherBits);
	/* 初始置换（IP置换） */
	DES_IP_Transform(cipherBits);

	/* 16轮迭代 */
	for (int cnt = 15; cnt >= 0; cnt--)
	{
		memcpy(copyRight, cipherBits + 32, 32);

		/* 将右半部分进行扩展置换，从32位扩展到48位 */
		DES_E_Transform(copyRight);
		/* 将右半部分与子密钥进行异或操作 */
		DES_XOR(copyRight, subKeys[cnt], 48);
		/* 异或结果进入S盒，输出32位结果 */
		DES_SBOX(copyRight);
		/* P置换 */
		DES_P_Transform(copyRight);
		/* 将明文左半部分与右半部分进行异或 */
		DES_XOR(cipherBits, copyRight, 32);

		if (cnt != 0)
		{
			/* 最终完成左右部的交换 */
			DES_Swap(cipherBits, cipherBits + 32);
		}
	}

	/* 逆初始置换（IP^1置换） */
	DES_IP_1_Transform(cipherBits);
	Bit64ToByte8(cipherBits, plainBlock);
	return 0;
}


HGResult HGAPI HGBase_DesEncrypt(HGByte* data, HGUInt size, const HGByte* key)
{
	if (NULL == data || 0 == size || 0 != size % 8 || NULL == key)
	{
		return HGBASE_ERR_INVALIDARG;
	}

	HGByte bKey[64];
	HGByte subKeys[16][48];
	HGByte plainBlock[8];

	/* 将密钥转换为二进制流 */
	Byte8ToBit64(key, bKey);
	/* 生成子密钥 */
	DES_MakeSubKeys(bKey, subKeys);

	HGByte* p = data;
	HGByte* pe = data + size;
	while (p < pe)
	{
		memcpy(plainBlock, p, 8);
		DES_EncryptBlock(plainBlock, subKeys, p);
		p += 8;
	}

	return HGBASE_ERR_OK;
}

HGResult HGAPI HGBase_DesDecrypt(HGByte* data, HGUInt size, const HGByte* key)
{
	if (NULL == data || 0 == size || 0 != size % 8 || NULL == key)
	{
		return HGBASE_ERR_INVALIDARG;
	}

	HGByte bKey[64];
	HGByte subKeys[16][48];
	HGByte cipherBlock[8];

	/* 将密钥转换为二进制流 */
	Byte8ToBit64(key, bKey);
	/* 生成子密钥 */
	DES_MakeSubKeys(bKey, subKeys);

	HGByte* p = data;
	HGByte* pe = data + size;
	while (p < pe)
	{
		memcpy(cipherBlock, p, 8);
		DES_DecryptBlock(cipherBlock, subKeys, p);
		p += 8;
	}

	return HGBASE_ERR_OK;
}