gost.cpp

各种加密算法的集合

#include "pch.h" 
#include "gost.h" 
 
NAMESPACE_BEGIN(CryptoPP) 
 
// these are the S-boxes given in Applied Cryptography 2nd Ed., p. 333 
const byte GOST::sBox[8][16]={ 
	{4, 10, 9, 2, 13, 8, 0, 14, 6, 11, 1, 12, 7, 15, 5, 3}, 
	{14, 11, 4, 12, 6, 13, 15, 10, 2, 3, 8, 1, 0, 7, 5, 9}, 
	{5, 8, 1, 13, 10, 3, 4, 2, 14, 15, 12, 7, 6, 0, 9, 11}, 
	{7, 13, 10, 1, 0, 8, 9, 15, 14, 4, 6, 12, 11, 2, 5, 3}, 
	{6, 12, 7, 1, 5, 15, 13, 8, 4, 10, 9, 14, 0, 3, 11, 2}, 
	{4, 11, 10, 0, 7, 2, 1, 13, 3, 6, 8, 5, 9, 12, 15, 14}, 
	{13, 11, 4, 1, 3, 15, 5, 9, 0, 10, 14, 7, 6, 8, 2, 12}, 
	{1, 15, 13, 0, 5, 7, 10, 4, 9, 2, 3, 14, 6, 11, 8, 12}}; 
 
/*	// these are the S-boxes given in the GOST source code listing in Applied 
	// Cryptography 2nd Ed., p. 644.  they appear to be from the DES S-boxes 
	{13,  2,  8,  4,  6, 15, 11,  1, 10,  9,  3, 14,  5,  0, 12,  7 }, 
	{ 4, 11,  2, 14, 15,  0,  8, 13,  3, 12,  9,  7,  5, 10,  6,  1 }, 
	{12,  1, 10, 15,  9,  2,  6,  8,  0, 13,  3,  4, 14,  7,  5, 11 }, 
	{ 2, 12,  4,  1,  7, 10, 11,  6,  8,  5,  3, 15, 13,  0, 14,  9 }, 
	{ 7, 13, 14,  3,  0,  6,  9, 10,  1,  2,  8,  5, 11, 12,  4, 15 }, 
	{10,  0,  9, 14,  6,  3, 15,  5,  1, 13, 12,  7, 11,  4,  2,  8 }, 
	{15,  1,  8, 14,  6, 11,  3,  4,  9,  7,  2, 13, 12,  0,  5, 10 }, 
	{14,  4, 13,  1,  2, 15, 11,  8,  3, 10,  6, 12,  5,  9,  0,  7 }};  
*/ 
 
bool GOST::sTableCalculated = false; 
word32 GOST::sTable[4][256]; 
 
GOST::GOST(const byte *userKey, CipherDir) 
	: key(8) 
{ 
	PrecalculateSTable(); 
 
	for (int j=0;j<8;j++) 
		key[j] = ((word32)userKey[4*j+3]<<24) | ((word32)userKey[4*j+2]<<16)  
			   | ((word32)userKey[4*j+1]<<8) | ((word32)userKey[4*j+0]); 
} 
 
void GOST::PrecalculateSTable() 
{ 
	if (!sTableCalculated) 
	{ 
		for (unsigned i = 0; i < 4; i++) 
			for (unsigned j = 0; j < 256; j++)  
			{ 
				word32 temp = sBox[2*i][j%16] | (sBox[2*i+1][j/16] << 4); 
				sTable[i][j] = rotl(temp, (11+8*i)%32); 
			} 
 
		sTableCalculated=true; 
	} 
} 
 
#define f(x)  ( t=x,												\ 
				sTable[3][GETBYTE(t, 3)] ^ sTable[2][GETBYTE(t, 2)]	\ 
			  ^ sTable[1][GETBYTE(t, 1)] ^ sTable[0][GETBYTE(t, 0)]	) 
 
void GOSTEncryption::ProcessBlock(const byte *inBlock, byte * outBlock) const 
{ 
	register word32 n1, n2, t; 
 
#ifdef IS_LITTLE_ENDIAN 
	n1 = *(word32 *)inBlock; 
	n2 = *(word32 *)(inBlock+4); 
#else 
	n1 = byteReverse(*(word32 *)inBlock); 
	n2 = byteReverse(*(word32 *)(inBlock+4)); 
#endif 
 
	for (unsigned i=0; i<3; i++) 
	{ 
		n2 ^= f(n1+key[0]); 
		n1 ^= f(n2+key[1]); 
		n2 ^= f(n1+key[2]); 
		n1 ^= f(n2+key[3]); 
		n2 ^= f(n1+key[4]); 
		n1 ^= f(n2+key[5]); 
		n2 ^= f(n1+key[6]); 
		n1 ^= f(n2+key[7]); 
	} 
 
	n2 ^= f(n1+key[7]); 
	n1 ^= f(n2+key[6]); 
	n2 ^= f(n1+key[5]); 
	n1 ^= f(n2+key[4]); 
	n2 ^= f(n1+key[3]); 
	n1 ^= f(n2+key[2]); 
	n2 ^= f(n1+key[1]); 
	n1 ^= f(n2+key[0]); 
 
#ifdef IS_LITTLE_ENDIAN 
	*(word32 *)outBlock = n2; 
	*(word32 *)(outBlock+4) = n1; 
#else 
	*(word32 *)outBlock = byteReverse(n2); 
	*(word32 *)(outBlock+4) = byteReverse(n1); 
#endif 
} 
 
void GOSTDecryption::ProcessBlock(const byte *inBlock, byte * outBlock) const 
{ 
	register word32 n1, n2, t; 
 
#ifdef IS_LITTLE_ENDIAN 
	n1 = *(word32 *)inBlock; 
	n2 = *(word32 *)(inBlock+4); 
#else 
	n1 = byteReverse(*(word32 *)inBlock); 
	n2 = byteReverse(*(word32 *)(inBlock+4)); 
#endif 
 
	n2 ^= f(n1+key[0]); 
	n1 ^= f(n2+key[1]); 
	n2 ^= f(n1+key[2]); 
	n1 ^= f(n2+key[3]); 
	n2 ^= f(n1+key[4]); 
	n1 ^= f(n2+key[5]); 
	n2 ^= f(n1+key[6]); 
	n1 ^= f(n2+key[7]); 
 
	for (unsigned i=0; i<3; i++) 
	{ 
		n2 ^= f(n1+key[7]); 
		n1 ^= f(n2+key[6]); 
		n2 ^= f(n1+key[5]); 
		n1 ^= f(n2+key[4]); 
		n2 ^= f(n1+key[3]); 
		n1 ^= f(n2+key[2]); 
		n2 ^= f(n1+key[1]); 
		n1 ^= f(n2+key[0]); 
	} 
 
#ifdef IS_LITTLE_ENDIAN 
	*(word32 *)outBlock = n2; 
	*(word32 *)(outBlock+4) = n1; 
#else 
	*(word32 *)outBlock = byteReverse(n2); 
	*(word32 *)(outBlock+4) = byteReverse(n1); 
#endif 
} 
 
NAMESPACE_END