enc.cpp

aes加密与des加密（包括三重des加密与cbc工作模式）

#include <stdio.h>
#include <stdlib.h>

#include <string.h>
#include <assert.h>

#include "enc.h"

void GetSubKey(bool subkey[16][48],const char Key[8]);
void PC1_func(bool output[56],bool input[64]);
void PC2_func(bool output[48],bool input[56]);
void IP1_func(bool output[64],bool input[64]);
void IP2_func(bool output[64],bool input[64]);
void E_func(bool output[48],bool input[32]);
void P_func(bool output[32],bool input[32]);
void S_func(bool output[32], const bool input[48]);
void ByteToBit(bool *output, const char *input, int bits);
void BitToByte(char *output, const bool *input, int bits);
void leftshift(bool *output,bool *input, int len, int loop);
void F_func(bool output[32],bool R0[32], const bool K[48]);
void Xor(bool *InA, const bool *InB, int len);

//iv--初始向量,CBC模式用到,一般模式iv为0
void DESEnc(char output[8], char input[8], bool subkey[16][48], char iv[64]);
void DESDec(char output[8], char input[8], bool subkey[16][48], char iv[64]);

//////////////////////////////////////////////////////////////////////////

// initial permutation IP
const static char 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
};
// final permutation IP^-1 
const static char IPR_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
};
// expansion operation matrix
const static char E_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
};
// 32-bit permutation function P used on the output of the S-boxes 
const static char P_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
};
// permuted choice table (key) 
const static char PC1_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
};
// permuted choice key (table) 
const static char PC2_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
};
// number left rotations of pc1 
const static char LOOP_Table[16] = {
	1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1
};
// The (in)famous S-boxes 
const static char S_Box[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
};

//////////////////////////////////////////////////////////////////////////

/*密钥正确*/
void GetSubKey(bool subkey[16][48],const char key[8])
{
	assert(subkey!=NULL&&key!=NULL);

	bool bitkey[64];
	ByteToBit(bitkey,key,64);

	bool pc1key[56];
	PC1_func(pc1key,bitkey);

	bool KC[16][28],KD[16][28],KCD[16][56];
	memcpy(KC[0],&pc1key[0],28);
	memcpy(KD[0],&pc1key[28],28);
	
	for(int i=0;i<16;i++)
	{
		leftshift(KC[i+1],KC[i],28,LOOP_Table[i]);
		leftshift(KD[i+1],KD[i],28,LOOP_Table[i]);

		memcpy(&KCD[i][0],KC[i+1],28);
		memcpy(&KCD[i][28],KD[i+1],28);

		PC2_func(subkey[i],KCD[i]);
		
		/*
		printf("\nsubkey[%02d]:{ ",i);
		char tmp[6];
		BitToByte(tmp,subkey[i],48);
		for(int j=0;j<6;j++)
		{
			printf("%d ",tmp[j]);
		}
		printf("}\n");
		*/
	}
}

void PC1_func(bool output[56],bool input[64])
{
	for(int i=0;i<56;i++)
	{
		output[i] = input[PC1_Table[i]-1];
	}
}

void PC2_func(bool output[48],bool input[56])
{
	for(int i=0;i<48;i++)
	{
		output[i] = input[PC2_Table[i]-1];
	}
}

void IP1_func(bool output[64],bool input[64])
{
	for(int i=0;i<64;i++)
	{
		output[i] = input[IP_Table[i]-1];
	}
}

void IP2_func(bool output[64],bool input[64])
{
	for(int i=0;i<64;i++)
	{
		output[i] = input[IPR_Table[i]-1];
	}	
}

void E_func(bool output[48],bool input[32])
{
	for(int i=0;i<48;i++)
	{
		output[i] = input[E_Table[i]-1];
	}	
}

void P_func(bool output[32],bool input[32])
{
	for(int i=0;i<32;i++)
	{
		output[i] = input[P_Table[i]-1];
	}	
}

void S_func(bool output[32], const bool input[48])
{
    for(char i=0,j,k; i<8; i++,input+=6,output+=4) 
	{
        j = (input[0]<<1) + input[5];
        k = (input[1]<<3) + (input[2]<<2) + (input[3]<<1) + input[4];
		ByteToBit(output, &S_Box[i][j][k], 4);
    }
}

void leftshift(bool *output,bool *input, int len, int loop)
{
	memcpy(output,input,len);

	bool tmp[255];
    memcpy(tmp,output,loop);
    memcpy(output,output+loop,len-loop);
    memcpy(output+len-loop,tmp,loop);
}

void F_func(bool output[32],bool R[32], const bool K[48])
{
    bool MR[48];
	E_func(MR,R);
    Xor(MR, K, 48);
	bool tmp[32];
    S_func(tmp,MR);
	P_func(output,tmp);
}

void Xor(bool *InA, const bool *InB, int len)
{
    for(int i=0; i<len; ++i)
	{
		InA[i] ^= InB[i];
	}
}

void ByteToBit(bool *output, const char *input, int bits)
{
	for(int i=0;i<bits;++i)
	{
		output[i] = ( input[i/8] >> ( i&7 ) ) & 1;//i%8
	}
}

void BitToByte(char *output, const bool *input, int bits)
{
	memset(output,0,bits/8);
    for(int i=0; i<bits; ++i)
	{
		output[i/8] |= input[i] << ( i&7 );
	}  
}

void DESEnc(char output[8], char input[8], bool subkey[16][48], char iv[64])
{
    bool bitinput[64],bitoutput[64];
	ByteToBit(bitinput,input,64);

	bool achIV[64];
	if(iv)
	{
		ByteToBit(achIV,iv,64);
		Xor(bitinput,achIV,64);
	}

	bool ip_input[64];
	IP1_func(ip_input,bitinput);

	bool L[17][32],R[17][32];
	memcpy(L[0],&ip_input[0],32);
	memcpy(R[0],&ip_input[32],32);

	for(int i=0;i<16;i++)
	{
		memcpy(L[i+1],R[i],32);
		bool f_tmp[32];
		F_func(f_tmp,R[i],subkey[i]);
		Xor(f_tmp,L[i],32);
		memcpy(R[i+1],f_tmp,32);
	}

	bool LR[64];
	memcpy(&LR[0],R[16],32);
	memcpy(&LR[32],L[16],32);

	IP2_func(bitoutput,LR);

	BitToByte(output,bitoutput,64);
}

void DESDec(char output[8], char input[8], bool subkey[16][48], char iv[64])
{
    bool bitinput[64],bitoutput[64];
	ByteToBit(bitinput,input,64);
	
	bool ip_input[64];
	IP1_func(ip_input,bitinput);
	
	bool L[17][32],R[17][32];
	memcpy(R[16],&ip_input[0],32);
	memcpy(L[16],&ip_input[32],32);
	
	for(int i=15;i>=0;i--)
	{
		memcpy(R[i],L[i+1],32);
		bool f_tmp[32];
		F_func(f_tmp,R[i],subkey[i]);
		Xor(f_tmp,R[i+1],32);
		memcpy(L[i],f_tmp,32);
	}
	
	bool LR[64];
	memcpy(&LR[0],L[0],32);
	memcpy(&LR[32],R[0],32);
	
	IP2_func(bitoutput,LR);
	
	bool achIV[64];
	if(iv)
	{
		ByteToBit(achIV,iv,64);
		Xor(bitoutput,achIV,64);
	}
	
	BitToByte(output,bitoutput,64);
}

bool DesBlockEnc(char *output, char *input, int datalen, const char *key)
{
    if( !( output && input && key && (datalen=(datalen+7)&0xfffffff8) ) ) 
	{
		return false;
	}

	bool subkey[16][48];
	GetSubKey(subkey,key);
	
	for(int i=0,j=datalen>>3; i<j; i++,output+=8,input+=8)
	{
		DESEnc(output, input, subkey, NULL);
	}
	
	return true;
}

bool DesBlockDec(char *output, char *input, int datalen, const char *key)
{
    if( !( output && input && key && (datalen=(datalen+7)&0xfffffff8) ) ) 
	{
		return false;
	}
	
	bool subkey[16][48];
	GetSubKey(subkey,key);
	
	for(int i=0,j=datalen>>3; i<j; i++,output+=8,input+=8)
	{
		DESDec(output, input, subkey, NULL);
	}
	
	return true;
}

//key1与key3一般相等
bool DesBlockThriceEnc(char *output, char *input, int datalen, const char *key1,const char *key2,const char *key3)
{
	assert(key1&&key2);
	
    DesBlockEnc(output,input,datalen,key1);
	DesBlockDec(output,output,datalen,key2);
	if(key3)
	{
		DesBlockEnc(output,output,datalen,key3);
	}
	else
	{
		DesBlockEnc(output,output,datalen,key1);
	}
	
	return true;
}

//key1与key3一般相等
bool DesBlockThriceDec(char *output, char *input, int datalen, const char *key1,const char *key2,const char *key3)
{
	assert(key1&&key2);
	
	if(key3)
	{
		DesBlockDec(output,input,datalen,key3);
	}
	else
	{
		DesBlockDec(output,input,datalen,key1);
	}
	DesBlockEnc(output,output,datalen,key2);
	DesBlockDec(output,output,datalen,key1);
	
	return true;
}

bool DesBlockEncCBC(char *output, char *input, int datalen, const char *key, char *iv)
{
	assert(iv!=NULL);

	if( !( output && input && key && (datalen=(datalen+7)&0xfffffff8) ) ) 
	{
		return false;
	}
	
	bool subkey[16][48];
	GetSubKey(subkey,key);
	
	for(int i=0,j=datalen>>3; i<j; i++,output+=8,input+=8)
	{
		if(i==0)
		{
			DESEnc(output, input, subkey, iv);
		}
		else
		{
			DESEnc(output, input, subkey, output-8);
		}
	}
	
	return true;
}

bool DesBlockDecCBC(char *output, char *input, int datalen, const char *key, char *iv)
{
	assert(iv!=NULL);
	
	if( !( output && input && key && (datalen=(datalen+7)&0xfffffff8) ) ) 
	{
		return false;
	}
	
	bool subkey[16][48];
	GetSubKey(subkey,key);
	
	for(int i=0,j=datalen>>3; i<j; i++,output+=8,input+=8)
	{
		if(i==0)
		{
			DESDec(output, input, subkey, iv);
		}
		else
		{
			DESDec(output, input, subkey, input-8);
		}
	}
	
	return true;
}