des.cpp

des delphi算发原代码

#include "stdafx.h"
#include "des.h"

// 初始置换表 (IP)
static BYTE bInitSwapTable[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
} ;

// 初始逆置换表 (IP-1)
static BYTE bInitReSwapTable[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
} ;

// 位扩展表32-->48 (E)
static BYTE bBitExternTable[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
} ;

// 32位置换表--用于F的尾置换 (P)
static BYTE bTailSwapTable[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
} ;

// 8个S盒 (S)
static BYTE SB[8][4][16] = {
	{
		14, 4, 13, 1, 1, 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
	},
		
	{
		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
	},
	
	{
		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
	},
	
	{
		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
	},
	
	{
		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
	},
	
	{
		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
	},
	
	{
		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
	},
	
	{
		13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 13, 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
	}
} ;

// 置换选择表一 (PC-1)
static BYTE bSelSwapTable_1[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
} ;

// 置换选择表二 (PC-2)
static BYTE bSelSwapTable_2[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
} ;

// 位掩码表
static BYTE bBitMask[8] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 } ;

#define TestBit(pByte,nBitIndex) pByte[(nBitIndex)>>3]&pByte[(~(nBitIndex))&7]
#define SetBit1(pByte,nBitIndex) pByte[(nBitIndex)>>3]|=pByte[(~(nBitIndex))&7]
#define SetBit0(pByte,nBitIndex) pByte[(nBitIndex)>>3]&=(~(pByte[(~(nBitIndex))&7]))

//
// DES加密
//
void CDES::DES_Encrypt ( )
{
	this->DES_SysInit() ;
	this->DESGenSubKey () ;

	this->DESInitSwap () ;
	for ( BYTE i = 1; i <= 16; i++ )
		this->DESSingleTurn ( i, true ) ;
	this->DESInitReSwap () ;
}

//
// DES解密
//
void CDES::DES_Decrypt ( )
{
	this->DES_SysInit() ;
	this->DESGenSubKey () ;

	this->DESInitSwap () ;
	for ( BYTE i = 1; i <= 16; i++ )
		this->DESSingleTurn ( i, false ) ;
	this->DESInitReSwap () ;
}

//
// 初始置换
//
void CDES::DESInitSwap ( )
{
	// R[16]-L[16] 构成64位，经初始逆置换
	for ( UINT i = 0; i < 32; i++ )
	{
		if ( bOriMsg[(bInitSwapTable[i]-1)>>3] & bBitMask[(~(bInitSwapTable[i]-1))&7] )
			this->LMsg[0][i>>3] |= bBitMask[(~i)&7] ;
		else
			this->LMsg[0][i>>3] &= ( ~(bBitMask[(~i)&7]) );

		if ( bOriMsg[(bInitSwapTable[i+32]-1)>>3] & bBitMask[(~(bInitSwapTable[i+32]-1))&7] )
			this->RMsg[0][i>>3] |= bBitMask[(~i)&7] ;
		else
			this->RMsg[0][i>>3] &= ( ~(bBitMask[(~i)&7]) );
	}
}

// 
// 初始逆置换
//
void CDES::DESInitReSwap ()
{
	// R[16]-L[16] 构成64位，经初始逆置换
	for ( UINT i = 0; i < 64; i++ )
	{
		if ( bInitReSwapTable[i] <= 32 )
		{
			if ( RMsg[16][(bInitReSwapTable[i]-1)>>3] & bBitMask[(~(bInitReSwapTable[i]-1))&7] )
				this->bCryptedMsg[i>>3] |= bBitMask[(~i)&7] ;
			else
				this->bCryptedMsg[i>>3] &= ( ~(bBitMask[(~i)&7]) ) ;
		}
		else
		{
			if ( LMsg[16][(bInitReSwapTable[i]-32-1)>>3] & bBitMask[(~(bInitReSwapTable[i]-32-1))&7] )
				this->bCryptedMsg[i>>3] |= bBitMask[(~i)&7] ;
			else
				this->bCryptedMsg[i>>3] &= ( ~(bBitMask[(~i)&7]) ) ;
		}
	}
}

//
// 产生子密钥
//
void CDES::DESGenSubKey ( )
{
	memset ( this->bSubKey, 0, sizeof(this->bSubKey) ) ;

	// 置换选择一
	BYTE bByteIndex, bBitIndex, bTemp[7] = {0} ;
	for ( UINT i = 0; i < 56; i++ )
	{
		bByteIndex	= ( bSelSwapTable_1[i] - 1 ) / 8 ;
		bBitIndex	= 7 - ( bSelSwapTable_1[i] - 1 ) % 8 ;
		if ( this->bKey[bByteIndex] & bBitMask[bBitIndex] )
			bTemp[i>>3] |= bBitMask[(~i)&7] ;
	}

	// 产生子密钥过程
	BYTE bTempKey[7] = {0} ;
	for ( UINT uTurn = 1; uTurn <= 16; uTurn ++ )
	{
		UINT bShiftBit = 2 ;
		if ( uTurn == 1 || uTurn == 2 || uTurn == 9 || uTurn == 16 )
			bShiftBit = 1 ;

		// 循环移位
		for ( i = bShiftBit; i < (28+bShiftBit); i++ )
		{
			if ( bTemp[(i%28)>>3] & bBitMask[(~(i%28))&7] )
				bTempKey[(i-bShiftBit)>>3] |= bBitMask[(~(i-bShiftBit))&7] ;

			if ( bTemp[(i%28+28)>>3] & bBitMask[(~(i%28+28))&7] )
				bTempKey[(i+28-bShiftBit)>>3] |= bBitMask[(~(i+28-bShiftBit))&7] ;
		}

		// 置换选择二
		for ( i = 0; i < 48; i++ )
		{
			bByteIndex	= ( bSelSwapTable_2[i] - 1 ) / 8 ;
			bBitIndex	= 7 - ( bSelSwapTable_2[i] - 1 ) % 8 ;

			if ( bTempKey[bByteIndex] & bBitMask[bBitIndex] )
				this->bSubKey[uTurn][i>>3] |= bBitMask[(~i)&7] ;
		}

		//cout << "turn " << uTurn << "\t :  " ;
		//this->Output ( bTempKey, 7 ) ;

		memcpy ( bTemp, bTempKey, 7 ) ;
		memset ( bTempKey, 0, sizeof(bTempKey) ) ;
	}
}

//
// DES的单轮加密过程
//
void CDES::DESSingleTurn ( BYTE nTurnIndex, BOOL bMode )
{
	// L[n] = R[n-1]
	for ( UINT i = 0; i < 4; i++ )
		LMsg[nTurnIndex][i] = RMsg[nTurnIndex-1][i] ;
	
	// DES的F函数，（内部处理：R[n] = F( R[n-1], k[n] )）
	this->DES_f ( nTurnIndex, bMode ) ;
	
	// R[n] = L[n-1] xor F( R[n-1], k[n] ) ;
	for ( i = 0; i < 4; i++ )
		RMsg[nTurnIndex][i] ^= LMsg[nTurnIndex-1][i] ;
}

//
// DES的F函数
//
void CDES::DES_f ( BYTE bTurnIndex, BOOL bMode )
{
	PBYTE	R = RMsg[bTurnIndex-1] ;
	BYTE	bTemp[6] = {0} ;
	BYTE	C[4] = {0} ;
	
	// 扩展 R --> E(R)，结果保存在bTemp
	for ( BYTE i = 0; i < 48; i++ )
	{
		if ( R[(bBitExternTable[i]-1)>>3] & bBitMask[(~(bBitExternTable[i]-1))&7] )
			bTemp[i>>3] |= bBitMask[(~i)&7] ;
		else
			bTemp[i>>3] &= ( ~(bBitMask[(~i)&7]) );
	}
	
	// E(R) xor K，结果保存在bTemp
	for ( i = 0; i < 6; i++ )
	{
		if ( bMode )
			bTemp[i] ^= this->bSubKey[bTurnIndex][i] ;
		else
			bTemp[i] ^= this->bSubKey[17-bTurnIndex][i] ;
	}
	
	BYTE bStartPos = 0, bTarPos = 0, bTarValue ;
	BYTE bRowIndex = 0, bColIndex = 0 ;
	for ( BYTE bBoxIndex = 0; bBoxIndex < 8; bBoxIndex ++ )
	{
		// 确定行值
		if ( bTemp[bStartPos>>3] & bBitMask[(~bStartPos)&7] )
			bColIndex += 2 ;
		if ( bTemp[(bStartPos+5)>>3] & bBitMask[(~(bStartPos+5))&7] )
			bColIndex += 1 ;
		
		// 确定列值
		if ( bTemp[(bStartPos+1)>>3] & bBitMask[(~(bStartPos+1))&7] )
			bRowIndex += 8 ;
		if ( bTemp[(bStartPos+2)>>3] & bBitMask[(~(bStartPos+2))&7] )
			bRowIndex += 4 ;
		if ( bTemp[(bStartPos+3)>>3] & bBitMask[(~(bStartPos+3))&7] )
			bRowIndex += 2 ;
		if ( bTemp[(bStartPos+4)>>3] & bBitMask[(~(bStartPos+4))&7] )
			bRowIndex += 1 ;
		
		// 在S(i)盒中由上面行列所对应的值bTarValue
		bTarValue = SB[bBoxIndex][bColIndex][bRowIndex] ;
		
		// 把bTarValue转化成对应的C(i)
		if ( bTarValue >= 8 )
		{
			C[bTarPos>>3] |= bBitMask[(~bTarPos)&7] ;
			bTarValue -= 8 ;
		}
		if ( bTarValue >= 4 )
		{
			C[(bTarPos+1)>>3] |= bBitMask[(~(bTarPos+1))&7] ;
			bTarValue -= 4 ;
		}
		if ( bTarValue >= 2 )
		{
			C[(bTarPos+2)>>3] |= bBitMask[(~(bTarPos+2))&7] ;
			bTarValue -= 2 ;
		}
		if ( bTarValue >= 1 )
		{
			C[(bTarPos+3)>>3] |= bBitMask[(~(bTarPos+3))&7] ;
			bTarValue -= 1 ;
		}		
	
		bRowIndex	= bColIndex = 0 ;
		bStartPos	+= 6 ;
		bTarPos		+= 4 ;
	}
	
	// 尾置换
	for ( i = 0; i < 32; i++ )
	{
		if ( C[(bTailSwapTable[i]-1)>>3] & bBitMask[(~(bTailSwapTable[i]-1))&7] )
			this->RMsg[bTurnIndex][i>>3] |= bBitMask[(~i)&7] ;
		else
			this->RMsg[bTurnIndex][i>>3] &= ( ~(bBitMask[(~i)&7]) );
	}
}

void CDES::DES_SysInit ()
{
	memset ( LMsg,		0, sizeof(LMsg) ) ;
	memset ( RMsg,		0, sizeof(RMsg) ) ;
	memset ( bSubKey,	0, sizeof(bSubKey) ) ;
	memset ( bCryptedMsg,	0, sizeof(bCryptedMsg) ) ; 
}

void CDES::DES_SetOriMsg ( PBYTE pMsg, UINT uLen )
{
	memset ( this->bOriMsg, 0, sizeof(this->bOriMsg) ) ;
	memcpy ( this->bOriMsg, pMsg, uLen ) ;
}

void CDES::DES_SetKey ( PBYTE pKey, UINT uLen )
{
	memset ( this->bKey, 0, sizeof(this->bKey) ) ;
	memcpy ( this->bKey, pKey, uLen ) ;
}