ecc.c

C语言

	if((chlong>=7)&&(chlong%7!=0))        //剩余字符的存放
	{
		if(chlong%7 < 4)           //剩余字符少余4个时，只需一个mp_digit单元存放
		{
			for(j=chlong-1;j>=i;j--)
			{
			   *temp |= (mp_digit)(ch[j] & 255);
               *temp <<= (mp_digit)CHAR_BIT;
			}
			*temp >>= (mp_digit)8;
			a->used=chlong*2/7+1;
		}
		else
		{                       //剩余字符不小于4个时，需两个mp_digit单元存放
			i+=4;
            *temp |= (mp_digit)(ch[i-1] & yy);
		    *temp <<= (mp_digit)CHAR_BIT;
            *temp |= (mp_digit)(ch[i-2] & 255);
		    *temp <<= (mp_digit)CHAR_BIT;
            *temp |= (mp_digit)(ch[i-3] & 255);
		    *temp <<= (mp_digit)CHAR_BIT;
            *temp++ |= (mp_digit)(ch[i-4] & 255); //存放被切分的字符的低四位

            
            for(j=chlong-1;j>=i;j--)
			{  
			   *temp |= (mp_digit)(ch[j] & 255);
			   *temp <<= (mp_digit)CHAR_BIT;			                
			}
            *temp >>= (mp_digit)4;
            *temp |= (mp_digit)((ch[i-1] & 255) >> 4);  //存放被切分的字符的高四位
            
			a->used=chlong*2/7+2;
		}

	}
	else
	{
	   a->used=chlong*2/7;
	}
	return MP_OKAY;
}


void Ecc_encipher(mp_int *qx,mp_int *qy, mp_int *px, mp_int *py,mp_int *a,mp_int *p){

	mp_int mx, my;
	mp_int c1x, c1y;
	mp_int c2x, c2y;
    mp_int r;
	mp_int tempx, tempy;
    bool zero=false;
    FILE *fp,*fq;
	int i;
    char miwenx[280]={0};
    char miweny[280]={0};
	char stemp[650]={0};


	mp_init(&mx);
	mp_init(&my);
	mp_init(&c1x);
	mp_init(&c1y);
	mp_init(&c2x);
	mp_init(&c2y);
    mp_init(&r);
	mp_init(&tempx);
	mp_init(&tempy);

	GetPrime(&r, 100);

	char filehead[60],filefoot[20],filename[85]={0};
    cout<<"File to encrypt(e.g:  c:\\code\\ecc\\test  ):"<<endl;
	cin>>filehead;
    cout<<"Extension(e.g:  .txt  ):"<<endl;
	cin>>filefoot;
	strcpy(filename,filehead);
	strcat(filename,filefoot);
	

//打开要加密文件
	if((fp=fopen(filename,"rb"))==NULL)
	{
		printf("can not open the file!");
		exit(1);
	}

	unsigned int FileLong=0;//文件字符长度
	char ChTem;//临时字符变
	int Frequency=0;
	int Residue=0;

    while( !feof(fp) )//找文件字符长度
	{
		ChTem = fgetc( fp );
		FileLong++;
	}
    --FileLong;


	Frequency = FileLong/EN_LONG;
	Residue = FileLong%EN_LONG;

	int enlongtemp=EN_LONG/2;
	//printf("%d\n",Frequency);  
	//printf("%d\n",Residue);  

	char filemi[85];
	strcpy(filemi,filehead);
	strcat(filemi,"en");
	strcat(filemi,filefoot);
    

 //打开保存密文文件
    if((fq=fopen(filemi,"wb"))==NULL)
	{
		 printf("can not open the file!\n");
		 exit(1);
	}

    printf("\nencrypting...\n");


	rewind(fp);
	for(i=0; i<Frequency; i++)
	{   
  
	    fread(miwenx,1,enlongtemp,fp);//读入字符串
	    miwenx[enlongtemp]=char(255);

		fread(miweny,1,enlongtemp,fp);//读入字符串
	    miweny[enlongtemp]=char(255);

        putin(&mx, miwenx,enlongtemp+1);//文件存入 		
		putin(&my, miweny,enlongtemp+1);//文件存入

	    Ecc_points_mul(&c2x,&c2y,px,py,&r,a,p);//加密
	    Ecc_points_mul(&tempx,&tempy,qx,qy,&r,a,p); 
	    Two_points_add(&mx,&my,&tempx,&tempy,&c1x,&c1y,a,zero,p);

        //保存密文      
	    chmistore(&c1x,fq); 
		chmistore(&c1y,fq);
		chmistore(&c2x,fq);
		chmistore(&c2y,fq);

	}
	//剩余字符处理
	if ( Residue > 0)
	{
	     if (Residue <= enlongtemp ) 
		{
			fread(miwenx,1,Residue,fp);//读入字符串
			miwenx[Residue]=char(255);
     
			putin(&mx, miwenx,Residue+1);//文件存入 

			mp_zero(&my);
        
		}
		else
		{

			fread(miwenx,1,enlongtemp,fp);//读入字符串
			miwenx[enlongtemp]=char(255);
        

			fread(miweny,1,Residue-enlongtemp,fp);//读入字符串
			miweny[Residue-enlongtemp]=char(255);

			 putin(&mx, miwenx,enlongtemp+1);//文件存入 

			putin(&my, miweny,Residue-enlongtemp+1);//文件存入 
		}

		Ecc_points_mul(&c2x,&c2y,px,py,&r,a,p);//加密

	    Ecc_points_mul(&tempx,&tempy,qx,qy,&r,a,p); 

        
		Two_points_add(&mx,&my,&tempx,&tempy,&c1x,&c1y,a,zero,p);

	 
        //保存密文      
	    chmistore(&c1x,fq); 

		chmistore(&c1y,fq);

		chmistore(&c2x,fq);

		chmistore(&c2y,fq);  
	}

	
		cout<<"\nok!encrypted!"<<endl;
	    cout<<"Saved in binary"<<endl;
	    cout<<"Patch:  "<<filemi<<endl ;


	    fclose(fq);
        fclose(fp);
        mp_clear(&mx);
		mp_clear(&my);
	    mp_clear(&c1x);
	    mp_clear(&c1y);
	    mp_clear(&c2x);
	    mp_clear(&c2y);
        mp_clear(&r);
	    mp_clear(&tempx);
		mp_clear(&tempy);
     

}

//取密文

int miwendraw(mp_int *a,char *ch,int chlong)
{
    mp_digit *temp;
    int i,j,res;

    if(a->alloc<chlong/4)
	{
		if((res=mp_grow(a,chlong/4))!=MP_OKAY)
			return res;
	}

	a->alloc=chlong/4;
    a->sign=0;
	mp_zero(a);
	temp=a->dp;
	i=0;

	for(j=0;j<chlong/4;j++)
	{
		i+=4;
		*temp |= (mp_digit)(ch[i-4] & 255);
		*temp <<= (mp_digit)CHAR_BIT;
        *temp |= (mp_digit)(ch[i-3] & 255);
		*temp <<= (mp_digit)CHAR_BIT;
        *temp |= (mp_digit)(ch[i-2] & 255);
		*temp <<= (mp_digit)CHAR_BIT;
        *temp++ |= (mp_digit)(ch[i-1] & 255); 
	}
    a->used=chlong/4;
    return MP_OKAY;
}

//实现将mp_int数a中的比特串还原为字符串并赋给字符串ch：
int chdraw(mp_int *a,char *ch)
{
	int i,j;
	mp_digit *temp,xx,yy;

	temp=a->dp;
	i=0;
	yy=(mp_digit)255;  //用于位与运算，取八位比特串
	xx=(mp_digit)15;  //用于位与运算，取四位比特串

	for(j=0;j<a->used/2;j++)  //以两个单元为循环，把两个单元的比特串赋给7个字符
	{
		i+=7;
        ch[i-4]=(char)(*++temp & xx);
        ch[i-3]=(char)((*temp >> (mp_digit)4) & yy);	
		ch[i-2]=(char)((*temp >> (mp_digit)12) & yy);
        ch[i-1]=(char)((*temp-- >> (mp_digit)20) & yy);

		ch[i-7]=(char)(*temp & yy);
		ch[i-6]=(char)((*temp >> (mp_digit)8) & yy);
		ch[i-5]=(char)((*temp >> (mp_digit)16) & yy);
		ch[i-4] <<= 4;
		ch[i-4]+=(char)((*temp++ >> (mp_digit)24) & xx);
		temp++;
	}
	if(a->used%2!=0)  //剩于一个单元的处理
	{
		ch[i++] = (char)(*temp & yy);
		ch[i++] = (char)((*temp >> (mp_digit)8) & yy);
		ch[i++] = (char)((*temp >> (mp_digit)16) & yy);
	}
	--i;
    while(int(ch[i]&0xFF) != 255 && i>0) i--;
	return i;
   
}

void Ecc_decipher(mp_int *k, mp_int *a,mp_int *p){

	mp_int c1x, c1y;
	mp_int c2x, c2y;
    mp_int tempx, tempy;
	mp_int mx, my;
    mp_int temp;

	mp_init(&temp);
	mp_init(&c1x);
	mp_init(&c1y);
    mp_init(&c2x);
	mp_init(&c2y);
	mp_init(&tempx);
	mp_init(&tempy);
    mp_init(&mx);
	mp_init(&my);

	mp_int tempzero;
	mp_init(&tempzero);

    int i, kk;
	char stemp[700]={0};
    FILE *fp,*fq;
    bool zero=false;


	char filehead[60],filefoot[20],filename[85]={0};
    cout<<"File to decrypt(e.g:  c:\\code\\ecc\\testen  ):"<<endl;
	cin>>filehead;
    cout<<"Extension(e.g:  .txt  ):"<<endl;
	cin>>filefoot;
	strcpy(filename,filehead);
	strcat(filename,filefoot);

    printf("\ndecrypting\n");

    if((fp=fopen(filename,"rb"))==NULL)
	{
		 printf("can not open the file!");
		 exit(1);
	}
 
   //打开保存解密结果文件
    char filemi[80];
	strcpy(filemi, filehead);
	strcat(filemi, "de");
    strcat(filemi, filefoot);

    if((fq=fopen(filemi,"wb"))==NULL)
	{
		 printf("can not open the file!");
		 exit(1);
	}


	rewind(fp);
    while(!feof(fp))
	{
         i=0;
		 while(1)
		{
		     stemp[i]=fgetc(fp);
		     if(i%4==0)
			{
                 if(int(stemp[i]&0xFF) == 255 ) goto L1;
			}
		    i++;
		}
		     
L1:     miwendraw(&c1x, stemp, i);
         i=0;
		 while(1)
		{
		     stemp[i]=fgetc(fp);
		     if(i%4==0)
			{
                 if(int(stemp[i]&0xFF) == 255 ) goto L2;
			}
		    i++;
		}
		     
L2:     miwendraw(&c1y, stemp, i);
	     i=0;
		 while(1)
		{
		     stemp[i]=fgetc(fp);
		     if(i%4==0)
			{
                 if(int(stemp[i]&0xFF) == 255 ) goto L3;
			}
		    i++;
		}
		     
L3:     miwendraw(&c2x, stemp, i);
	            i=0;
		 while(1)
		{
		     stemp[i]=fgetc(fp);
		     if(i%4==0)
			{
                 if(int(stemp[i]&0xFF) == 255 ) goto L4;
			}
		    i++;
		}
		     
L4:     miwendraw(&c2y, stemp, i);

	    mp_zero(&tempzero);
        if(mp_cmp(&c1x, &tempzero)==0) break;

        Ecc_points_mul(&tempx, &tempy, &c2x, &c2y, k, a, p); 

        mp_neg(&tempy, &temp);
        Two_points_add(&c1x,&c1y,&tempx,&temp,&mx,&my,a,zero,p);
	    
		int chtem;
	    chtem=chdraw(&mx,stemp);//从ming中取出字符串
     

		//保存解密结果
    
		for(kk=0;kk<chtem;kk++)
		{
	         fprintf(fq,"%c",stemp[kk]);
			       
		}

	    chtem=chdraw(&my,stemp);//从ming中取出字符串
    
	         
	     //保存解密结果
		  for(kk=0;kk<chtem;kk++)
		{
	          fprintf(fq,"%c",stemp[kk]);
			
		}
		  
	    
	}

   	cout<<"\nok!decrypted!"<<endl;
	cout<<"Patch:  "<<filemi<<endl;

    fclose(fq);
    fclose(fp);
    mp_clear(&c1x);
	mp_clear(&c1y);
	mp_clear(&c2x);
	mp_clear(&c2y);
    mp_clear(&tempx);
	mp_clear(&tempy);
	mp_clear(&mx);
	mp_clear(&my);
    mp_clear(&temp);


}



/*以下为libtomath库*/
#ifdef BN_MP_INIT_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis
 *
 * LibTomMath is a library that provides multiple-precision
 * integer arithmetic as well as number theoretic functionality.
 *
 * The library was designed directly after the MPI library by
 * Michael Fromberger but has been written from scratch with
 * additional optimizations in place.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, [e-mail], http://libtom.org
 */

/* init a new mp_int */
int mp_init (mp_int * a)
{
  int i;

  /* allocate memory required and clear it */
  a->dp = OPT_CAST(mp_digit) XMALLOC (sizeof (mp_digit) * MP_PREC);
  if (a->dp == NULL) {
    return MP_MEM;
  }

  /* set the digits to zero */
  for (i = 0; i < MP_PREC; i++) {
      a->dp[i] = 0;
  }

  /* set the used to zero, allocated digits to the default precision
   * and sign to positive */
  a->used  = 0;
  a->alloc = MP_PREC;
  a->sign  = MP_ZPOS;

  return MP_OKAY;
}
#endif

/* $Source: /cvs/libtom/libtommath/bn_mp_init.c,v $ */
/* $Revision: 1.4 $ */
/* $Date: 2006/12/28 01:25:13 $ */



#ifdef BN_MP_TORADIX_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis
 *
 * LibTomMath is a library that provides multiple-precision
 * integer arithmetic as well as number theoretic functionality.
 *
 * The library was designed directly after the MPI library by
 * Michael Fromberger but has been written from scratch with
 * additional optimizations in place.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, [e-mail], http://libtom.org
 */

/* stores a bignum as a ASCII string in a given radix (2..64) */
int mp_toradix (mp_int * a, char *str, int radix)
{
  int     res, digs;
  mp_int  t;
  mp_digit d;
  char   *_s = str;

  /* check range of the radix */
  if (radix < 2 || radix > 64) {
    return MP_VAL;
  }

  /* quick out if its zero */
  if (mp_iszero(a) == 1) {
     *str++ = '0';
     *str = '\0';
     return MP_OKAY;
  }

  if ((res = mp_init_copy (&t, a)) != MP_OKAY) {
    return res;
  }

  /* if it is negative output a - */
  if (t.sign == MP_NEG) {
    ++_s;
    *str++ = '-';
    t.sign = MP_ZPOS;
  }

  digs = 0;
  while (mp_iszero (&t) == 0) {
    if ((res = mp_div_d (&t, (mp_digit) radix, &t, &d)) != MP_OKAY) {
      mp_clear (&t);
      return res;
    }
    *str++ = mp_s_rmap[d];
    ++digs;
  }