Простой шифровальщик файлов

Написан на C:

Code:

#include <stdio.h>

main(int  argc, char *argv[])
{
 
  //char key[100],fname[100],ename[100];
  unsigned char key[100],fname[100],ename[100];
  FILE *fpi,*fpo,*fopen();
  int kkk[100];
  int i,j,k,c,p,pw_len,fn_len;

  printf("\n  ** File encryption/decryption program **\n\n");
  printf("  This program will take a password and filename ending in .E\n");
  printf("  and will decrypt the file to a file with the .E suffix removed.\n");
  printf("  If given a filename not ending in .E it will encrypt the file.\n");

  if(argc == 1)
    {
      printf("\nEnter the password: ");
      fgets(key,100,stdin);
      // Need to strip off the EOL
      pw_len=strlen(key);
      key[pw_len-1]='\0';

      printf("\nEnter the filename: ");
      fgets(fname,100,stdin);
      fn_len=strlen(fname);
      fname[fn_len-1]='\0';
    }
  else if(argc == 3)
    {
      strcpy(key,argv[1]);
      strcpy(fname,argv[2]);
    }
  else
    {
      printf("\n  ** Error!: Usage is %s <password> <filename>\n", argv[0]);
      exit(1);
    }

  pw_len=strlen(key)-1;
  for(i=0;i<pw_len;i++)
    {
      kkk[i]=(int)key[i];
    }

  fn_len=strlen(fname);
 
  if (fname[fn_len-2]=='.' && fname[fn_len-1]=='E')
    // Decrypt mode
    {
      //strncpy(ename,fname,(fn_len-3));
      strcpy(ename,fname);
      ename[fn_len-2]='\0';
      printf("\nThe output file will be named: %s\n",ename);
    }
  else{
    //Encrypt mode
    strncpy(ename,fname,fn_len);
    ename[fn_len]='.';
    ename[fn_len+1]='E';
    ename[fn_len+2]='\0';
    printf("\nThe output file will be named: %s\n",ename);
  }
 

  if((fpi=fopen(fname,"r"))==NULL)
    {
      printf("\nError - file %s not found",fname);
      exit(1);
    }
  if((fpo=fopen(ename,"w"))==NULL)
    {
      printf("\nError - file %s not opened",ename);
      exit(1);
    }

  j=0;
 
  while((c = getc(fpi)) != EOF)
    {
      if(j == pw_len) j=0;
      p=c^kkk[j];
      putc(p,fpo);
      j++;
    }

}

Бинарники Win/Linux и исходник: https://yadi.sk/d/fyGGv2FM1ZCy5Q
Неплохо было написать еще и брут для него.

 

Чем BestCrypt плох? Или TrueCrypt?