code.cpp

base64邮箱加密解密源码

#include <stdio.h>
#include <iostream.h>
#include <string.h>

char BASE64[64]={'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
	'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',
	'0','1','2','3','4','5','6','7','8','9','+','/'};

int main(void)
{
   FILE *in, *out;
   char filename[20];
   cout << "Please Input the file to decode:\n ";
   cin >> filename;
   if ((in = fopen(filename, "rb")) == NULL){
//   if ((in = fopen("e:\\cxh\\mail\\ding.wav", "rb")) == NULL){
      fprintf(stderr, "Cannot open input file.\n");
      return 1;
   }
   cout << "Please Input the file to save decoded:\n ";
   cin >> filename;
   if ((out = fopen(filename, "wt")) == NULL){
      fprintf(stderr, "Cannot open output file.\n");
      return 1;
   }

   unsigned long int ConvertChar=0;
   unsigned long int MASK=63;
   unsigned int InChar=0;
   unsigned int OutChar;
   unsigned long int TotalInChar = 0;
   int i;
   while (!feof(in)){
	   fgetc(in);
	   TotalInChar++;
   }
   TotalInChar-=1;;
   printf("%d",TotalInChar);
   rewind(in);
   for(i=0;i<TotalInChar/3;i++){
      InChar = fgetc(in);
      ConvertChar = InChar;
      InChar = fgetc(in);
      ConvertChar = ConvertChar*256 + InChar;
//      ConvertChar = ConvertChar << 8 + InChar;
      InChar = fgetc(in);
      ConvertChar = ConvertChar*256 + InChar;
//      ConvertChar = ConvertChar << 8 + InChar;
	  OutChar = ConvertChar >> 18;
      fputc(BASE64[OutChar], out);
//	  printf("%c/t",BASE64[OutChar]);
	  OutChar = (ConvertChar >> 12) & MASK;
      fputc(BASE64[OutChar], out);
//	  printf("%c/t",BASE64[OutChar]);
	  OutChar = (ConvertChar >> 6) & MASK;
      fputc(BASE64[OutChar], out);
//	  printf("%c/t",BASE64[OutChar]);
	  OutChar = ConvertChar & MASK;
      fputc(BASE64[OutChar], out);
//	  printf("%c/t",BASE64[OutChar]);
	  /*if(i/13>0 && i%13==0){
		fputc('=', out);
		fputc('=', out);
		fputc('=', out);
		fputc('=', out);
	  }*/
   }

   
   if(TotalInChar%3 == 1){
      InChar = fgetc(in);
      ConvertChar = InChar;
      ConvertChar = ConvertChar*256;
	  OutChar = (ConvertChar >> 6) & MASK;
      fputc(BASE64[OutChar], out);
	  OutChar = ConvertChar & MASK;
      fputc(BASE64[OutChar], out);
      fputc('=', out);
      fputc('=', out);
   }
   if(TotalInChar%3 == 2){
      InChar = fgetc(in);
      ConvertChar = InChar;
      InChar = fgetc(in);
      ConvertChar = ConvertChar*256 + InChar;
	  OutChar = (ConvertChar >> 12) & MASK;
      fputc(BASE64[OutChar], out);
	  OutChar = (ConvertChar >> 6) & MASK;
      fputc(BASE64[OutChar], out);
	  OutChar = ConvertChar & MASK;
      fputc(BASE64[OutChar], out);
      fputc('=', out);
   }
      fputc('=', out);
      fputc('=', out);
      fputc('=', out);
      fputc('=', out);

   fclose(in);
   fclose(out);
   printf("write ok !");
   return 0;
}