CoreDes.cpp

#include "CoreDes.h"
BYTE    mask[8] = {0x80,0x40,0x20,0x10,0x08,0x04,0x02,0x1};
void IP(BIT64 *text)
{
	BYTE    ip_table[64] = { 58, 50, 42, 34, 26, 18, 10, 2,
		60, 52, 44, 36, 28, 20, 12, 4,
		62, 54, 46, 38, 30, 22, 14, 6,
		64, 56, 48, 40, 32, 24, 16, 8,
		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 };
	BYTE    i;
	BIT64   t;
	t.dw[0] = t.dw[1] = 0;
	for(i=0;i<64;i++)
	{
		BYTE    temp = ip_table[i] -1;
		if((text->b[temp/8] & mask[temp%8]) != 0)
			t.b[i/8] |= mask[i%8];
	}
	text->dw[0] = t.dw[0];
	text->dw[1] = t.dw[1];
}
void FP(BIT64 *text)
{
	BYTE    fp_table[64] = { 40,  8, 48, 16, 56, 24, 64, 32,
		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 };
	BYTE    i;
	BIT64   t;
	t.dw[0] = t.dw[1] = 0;
	for(i=0;i<64;i++)
	{
		BYTE    temp = fp_table[i] -1;
		if(text->b[temp/8] & mask[temp%8])
			t.b[i/8] |= mask[i%8];
	}
	text->dw[0] = t.dw[0];
	text->dw[1] = t.dw[1];
}
void MakeKey(BIT64 key, BIT64 keys[16])
{
	BYTE    i,j;
	BYTE    shift[16] = {1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};
	BYTE    init_table[56] = { 57, 49, 41, 33, 25, 17,  9,
		1, 58, 50, 42, 34, 26, 18,
		10,  2, 59, 51, 43, 35, 27,
		19, 11,  3, 60, 52, 44, 36,
		63, 55, 47, 39, 31, 23, 15,
		7, 62, 54, 46, 38, 30, 22,
		14,  6, 61, 53, 45, 37, 29,
		21, 13,  5, 28, 20, 12,  4 };
	BYTE    replace_table[48] = { 14, 17, 11, 24,  1,  5,
		3, 28, 15,  6, 21, 10,
		23, 19, 12,  4, 26,  8,
		16,  7, 27, 20, 13,  2,
		41, 52, 31, 37, 47, 55,
		30, 40, 51, 45, 33, 48,
		44, 49, 39, 56, 34, 53,
		46, 42, 50, 36, 29, 32 };
	BIT64   bit;
	/* PC-1 */
	bit.dw[0] = bit.dw[1] = 0;
	for(i=0;i<28;i++)
	{
		BYTE    temp = init_table[i] -1;
		if(key.b[temp/8] & mask[temp % 8])
			bit.b[i/8] |= mask[i%8];
		temp = init_table[i+28] -1;
		if(key.b[temp/8] & mask[temp % 8])
			bit.b[i/8 + 4] |= mask[i%8];
	}
	/* round 16 key */
	for(i=0;i<16;i++)
	{
		for(j=0;j<shift[i];j++)
		{
			BYTE temp = (BYTE)(bit.b[0] & 0x80);
			bit.b[0] <<= 1;
			if(bit.b[1] & 0x80)
				bit.b[0] += 1;
			bit.b[1] <<= 1;
			if(bit.b[2] & 0x80)
				bit.b[1] += 1;
			bit.b[2] <<= 1;
			if(bit.b[3] & 0x80)
				bit.b[2] += 1;
			bit.b[3] <<= 1;
			if(temp)
				bit.b[3] += 0x10;
			temp = (BYTE)(bit.b[4] & 0x80);
			bit.b[4] <<= 1;
			if(bit.b[5] & 0x80)
				bit.b[4] += 1;
			bit.b[5] <<= 1;
			if(bit.b[6] & 0x80)
				bit.b[5] += 1;
			bit.b[6] <<= 1;
			if(bit.b[7] & 0x80)
				bit.b[6] += 1;
			bit.b[7] <<= 1;
			if(temp)
				bit.b[7] += 0x10;
		}
		/* Compress and transpose  ==> 48 bit */
		keys[i].dw[0] = 0;
		keys[i].dw[1] = 0;
		for(j=0;j<48;j++)
		{
			BYTE    temp = replace_table[j] -1;
			if(temp < 28)
			{
				if(bit.b[temp / 8] & mask[temp%8])
					keys[i].b[j/6] |= mask[j%6];
			} else {
				temp = temp - 28;
				if(bit.b[temp/8 + 4] & mask[temp % 8])
					keys[i].b[j/6] |= mask[j%6];
			}
		}
	}
}
void RoundFunction(BIT64 key, BIT64 *text)
{
	BIT64   a;
	BIT64   t;
	BYTE    i,j;
	BYTE    expand_table[48] = { 32,  1,  2,  3,  4,  5,
		4,  5,  6,  7,  8,  9,
		8,  9, 10, 11, 12, 13,
		12, 13, 14, 15, 16, 17,
		16, 17, 18, 19, 20, 21,
		20, 21, 22, 23, 24, 25,
		24, 25, 26, 27, 28, 29,
		28, 29, 30, 31, 32,  1 };
	BYTE    tp_table[32] = { 16,  7, 20, 21,
		29, 12, 28, 17,
		1, 15, 23, 26,
		5, 18, 31, 10,
		2,  8, 24, 14,
		32, 27,  3,  9,
		19, 13, 30,  6,
		22, 11,  4, 25 };
	BYTE    s_table[8][64] = {
		{
			14,  0,  4, 15, 13,  7,  1,  4,  2, 14, 15,  2, 11, 13,  8,  1,
			3, 10, 10,  6,  6, 12, 12, 11,  5,  9,  9,  5,  0,  3,  7,  8,
			4, 15,  1, 12, 14,  8,  8,  2, 13,  4,  6,  9,  2,  1, 11,  7,
			15,  5, 12, 11,  9,  3,  7, 14,  3, 10, 10,  0,  5,  6,  0, 13
		}, {
			15,  3,  1, 13,  8,  4, 14,  7,  6, 15, 11,  2,  3,  8,  4, 14,
			9, 12,  7,  0,  2,  1, 13, 10, 12,  6,  0,  9,  5, 11, 10,  5,
			0, 13, 14,  8,  7, 10, 11,  1, 10,  3,  4, 15, 13,  4,  1,  2,
			5, 11,  8,  6, 12,  7,  6, 12,  9,  0,  3,  5,  2, 14, 15,  9
		}, {
			10, 13,  0,  7,  9,  0, 14,  9,  6,  3,  3,  4, 15,  6,  5, 10,
			1,  2, 13,  8, 12,  5,  7, 14, 11, 12,  4, 11,  2, 15,  8,  1,
			13,  1,  6, 10,  4, 13,  9,  0,  8,  6, 15,  9,  3,  8,  0,  7,
			11,  4,  1, 15,  2, 14, 12,  3,  5, 11, 10,  5, 14,  2,  7, 12
		}, {
			7, 13, 13,  8, 14, 11,  3,  5,  0,  6,  6, 15,  9,  0, 10,  3,
			1,  4,  2,  7,  8,  2,  5, 12, 11,  1, 12, 10,  4, 14, 15,  9,
			10,  3,  6, 15,  9,  0,  0,  6, 12, 10, 11,  1,  7, 13, 13,  8,
			15,  9,  1,  4,  3,  5, 14, 11,  5, 12,  2,  7,  8,  2,  4, 14
		}, {
			2, 14, 12, 11,  4,  2,  1, 12,  7,  4, 10,  7, 11, 13,  6,  1,
			8,  5,  5,  0,  3, 15, 15, 10, 13,  3,  0,  9, 14,  8,  9,  6,
			4, 11,  2,  8,  1, 12, 11,  7, 10,  1, 13, 14,  7,  2,  8, 13,
			15,  6,  9, 15, 12,  0,  5,  9,  6, 10,  3,  4,  0,  5, 14,  3
		}, {
			12, 10,  1, 15, 10,  4, 15,  2,  9,  7,  2, 12,  6,  9,  8,  5,
			0,  6, 13,  1,  3, 13,  4, 14, 14,  0,  7, 11,  5,  3, 11,  8,
			9,  4, 14,  3, 15,  2,  5, 12,  2,  9,  8,  5, 12, 15,  3, 10,
			7, 11,  0, 14,  4,  1, 10,  7,  1,  6, 13,  0, 11,  8,  6, 13
		}, {
			4, 13, 11,  0,  2, 11, 14,  7, 15,  4,  0,  9,  8,  1, 13, 10,
			3, 14, 12,  3,  9,  5,  7, 12,  5,  2, 10, 15,  6,  8,  1,  6,
			1,  6,  4, 11, 11, 13, 13,  8, 12,  1,  3,  4,  7, 10, 14,  7,
			10,  9, 15,  5,  6,  0,  8, 15,  0, 14,  5,  2,  9,  3,  2, 12,
		}, {
			13,  1,  2, 15,  8, 13,  4,  8,  6, 10, 15,  3, 11,  7,  1,  4,
			10, 12,  9,  5,  3,  6, 14, 11,  5,  0,  0, 14, 12,  9,  7,  2,
			7,  2, 11,  1,  4, 14,  1,  7,  9,  4, 12, 10, 14,  8,  2, 13,
			0, 15,  6, 12, 10,  9, 13,  0, 15,  3,  3,  5,  5,  6,  8, 11,
		}
	};
	/* Expand */
	t.dw[0] = t.dw[1] = 0;
	for(i=0;i<48;i++)
	{
		j = expand_table[i] + 31;
		if(text->b[j/8] & mask[j%8])
		{
			t.b[i/6] |= mask[i%6];
		}
	}
    /* XOR */
	for(i=0;i<8;i++)
	{
		t.b[i] ^= key.b[i];
	}
	/* S-BOX */
	a.dw[0] = a.dw[1] = 0;
	for(i=0;i<8;i++)
	{
		if(i%2 == 0)
			a.b[i/2] = s_table[i][t.b[i]>>2] << 4;
		else
			a.b[i/2] += s_table[i][t.b[i]>>2];
	}
	/* Transpose */
	t.dw[0] = t.dw[1] = 0;
	for(i=0;i<32;i++)
	{
		BYTE    temp = tp_table[i] -1;
		if(a.b[temp / 8] & mask[temp%8])
			t.b[i/8] |= mask[i%8];
	}
	text->dw[0] ^= t.dw[0];
}
void des_encryption(BIT64 key, BIT64 plain, BIT64 *out)
{
    BIT64   keys[16];
	BYTE    i;
	DWORD   t;
    /* Make Key */
    MakeKey(key,keys);
	/* Plain -> Out */
	out->dw[0] = plain.dw[0];
	out->dw[1] = plain.dw[1];
    /* IP */
    IP(out);
    /* Round 16 */
    for(i=0;i<16;i++)
    {
        /* Function */
        RoundFunction(keys[i],out);
        /* Swap */
		t = out->dw[0];
		out->dw[0] = out->dw[1];
		out->dw[1] = t;
    }
    /* Reset Swap */
	t = out->dw[0];
	out->dw[0] = out->dw[1];
	out->dw[1] = t;
    /* IP(-1) */
    FP(out);
}
void des_decryption(BIT64 key, BIT64 plain, BIT64 *out)
{
    BIT64   keys[16];
	BYTE    i;
	DWORD   t;
    /* Make Key */
    MakeKey(key,keys);
	/* Plain -> Out */
	out->dw[0] = plain.dw[0];
	out->dw[1] = plain.dw[1];
    /* IP */
    IP(out);
    /* Round 16 */
    for(i=0;i<16;i++)
    {
        /* Function */
        RoundFunction(keys[15-i],out);
        /* Swap */
		t = out->dw[0];
		out->dw[0] = out->dw[1];
		out->dw[1] = t;
    }
    /* Reset Swap */
	t = out->dw[0];
	out->dw[0] = out->dw[1];
	out->dw[1] = t;
    /* IP(-1) */
    FP(out);
}