idea.cpp

可以实现RIJNDEAL和IDEA 2种加密方法的完整程序,还可以看到加密的所用时间的情况

#include "StdAfx.h"
#include "Idea.h"

# define maxim 65537
# define fuyi  65536
# define one   65535
# define round     8

CIdea::CIdea(void)
{
}

CIdea::~CIdea(void)
{
}

void CIdea::Init( short unsigned uskey[] )
{
	key(uskey,Z);           /*   generate encryption subkeys Z[i][r]   */
	de_key(Z,DK);            /*   compute decryption subkeys DK[i][r]  */
}

bool CIdea::Encrypt( unsigned XX[], unsigned YY[])
{
	unsigned XXX[5],YYY[5];
	XXX[1] = XX[0];
	XXX[2] = XX[1];
	XXX[3] = XX[2];
	XXX[4] = XX[3];
	cip(XXX,YYY,Z);             /*     encipher XX to YY with key Z      */
	YY[0] = YYY[1];
	YY[1] = YYY[2];
	YY[2] = YYY[3];
	YY[3] = YYY[4];
	return 1;
}

bool CIdea::Decrypt( unsigned XX[], unsigned YY[] )
{
	unsigned XXX[5],YYY[5];
	XXX[1] = XX[0];
	XXX[2] = XX[1];
	XXX[3] = XX[2];
	XXX[4] = XX[3];
	cip(XXX,YYY,DK);             /*     encipher XX to YY with key Z      */
	YY[0] = YYY[1];
	YY[1] = YYY[2];
	YY[2] = YYY[3];
	YY[3] = YYY[4];
	return 1;
}

void CIdea::cip ( unsigned In[5], unsigned Out[5], unsigned Z[7][10] )
{
	unsigned  int r, x1, x2, x3, x4, kk, t1, t2, a;

	x1=In[1]; x2=In[2]; x3=In[3]; x4=In[4];
	for (r=1; r<=8; r++)   /*  the round function  */
	{
		/*   the group operation on 64-bits block  */
		x1 = mul(x1,Z[1][r]);        x4 = mul(x4,Z[4][r]);
		x2 = (x2 + Z[2][r]) & one;     x3 = ( x3 + Z[3][r] ) & one;
		/*   the function of the MA structure      */
		kk = mul( Z[5][r], (x1^x3) );
		t1 = mul( Z[6][r], ( kk + (x2^x4)) & one );
		t2 = ( kk + t1 ) & one;
		/*   the involutary permutation PI         */
		x1 = x1^t1;    x4 = x4^t2;
		a = x2^t2;    x2 = x3^t1;   x3 = a;
	}
	/*   the output transformation            */
	Out[1] = mul (x1, Z[1][round+1] );
	Out[4] = mul (x4, Z[4][round+1] );
	Out[2] = (x3 + Z[2][round+1] ) & one;
	Out[3] = (x2 + Z[3][round+1] ) & one;
}

unsigned CIdea::mul ( unsigned a, unsigned b)
{     
	long int p;
	long unsigned q;
	if ( a==0 ) p = maxim-b;
	else if ( b==0 )  p = maxim-a;  
	else
	{   
		q=(unsigned long)a*(unsigned long)b;
		p=(q & one) - (q>>16);  if (p<=0) p=p+maxim;
	}
	return ( unsigned ) ( p & one );
}

unsigned CIdea::inv ( unsigned xin)
{
	long  n1, n2, q, r, b1, b2, t;
	if ( xin == 0 ) b2 = 0;
	else 
	{
		n1=maxim; n2=xin; b2=1; b1=0;
		do 
		{
			r = (n1 % n2);
			q = (n1-r)/n2;
			if ( r== 0)
			{ 
				if ( b2<0 )
					b2 = maxim+b2; 
			}
			else 
			{ 
				n1=n2; 
				n2=r; 
				t=b2; 
				b2=b1-q*b2; 
				b1=t; 
			}
		}while ( r !=0 );
	}
	return ( unsigned) b2;
}

void CIdea::key ( short unsigned uskey[9], unsigned Z[7][10] )
{
	short unsigned	S[54];
	int i,j,r;
	for ( i =1; i<9; i++ ) S[i-1] = uskey[i];
	 /*    shifts     */
	for ( i = 8; i<54; i++ )
	 {
		if ( (i+2)%8 == 0)      /* for S[14], S[22], ... */
		    S[i] = ( S[i-7]<<9 )^( S[i-14]>>7 ) & one;
		else if ( (i+1)%8 == 0)  /* for S[15], S[23], .. */
		    S[i] = ( S[i-15]<<9 )^( S[i-14]>>7 ) & one;
	    else                     /* for other  S[i]       */
		    S[i] = ( S[i-7]<<9 )^( S[i-6]>>7 ) & one;
	    }
	 /*  get subkeys    */
	for ( r=1; r<=round+1; r++ ) 
	{
		for ( j=1; j<7; j++ )
		{
			Z[j][r] = S[ 6*(r-1) + j-1];
		}
	}
}

void CIdea::de_key ( unsigned Z[7][10], unsigned DK[7][10] )
{
	int j;
	for ( j = 1; j<=round+1; j++ )
	{  
		DK[1][round-j+2] = inv (Z[1][j]);
		DK[4][round-j+2] = inv (Z[4][j]);
		if (j==1 || j==round+1 ) 
		{
			DK[2][round-j+2] = ( fuyi-Z[2][j] ) & one;
			DK[3][round-j+2] = ( fuyi-Z[3][j] ) & one;
		}
		else 
		{
			DK[2][round-j+2] = ( fuyi-Z[3][j] ) & one;
			DK[3][round-j+2] = ( fuyi-Z[2][j] ) & one;
		}
	}
	for ( j=1; j<=round+1; j++ )
	{ 
		DK[5][round+1-j] = Z[5][j]; 
		DK[6][round+1-j] = Z[6][j]; 
	}
}