C string encryption XOR & base64

[JIHAD]

Exemplu de criptare XOR.

String -> base64 -> XOR -> base64.

avem si encryption key.

se compileaza. se executa ./enc -e string ptr. criptare si ./enc -d hash ptr. decriptare

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

#define TABLELEN        63
#define BUFFFERLEN      128

#define ENCODERLEN      4
#define ENCODEROPLEN    0
#define ENCODERBLOCKLEN 3

#define PADDINGCHAR     '='
#define BASE64CHARSET   "ABCDEFGHIJKLMNOPQRSTUVWXYZ"\
                        "abcdefghijklmnopqrstuvwxyz"\
                        "0123456789"\
                        "+/";
char key[100]="pass123";

int Base64Encode(char *input, char *output, int oplen);
int encodeblock(char *input, char *output, int oplen);
int Base64Decode(char *input, char *output, int oplen);
int decodeblock(char *input, char *output, int oplen);
int decodeblock(char *input, char *output, int oplen){
   int rc = 0;
   char decodedstr[ENCODERLEN + 1] = "";

   decodedstr[0] = input[0] << 2 | input[1] >> 4;
   decodedstr[1] = input[1] << 4 | input[2] >> 2;
   decodedstr[2] = input[2] << 6 | input[3] >> 0;
   strncat(output, decodedstr, oplen-strlen(output));

   return rc;
}

int Base64Decode(char *input, char *output, int oplen){
   char *charval = 0;
   char decoderinput[ENCODERLEN + 1] = "";
   char encodingtabe[TABLELEN + 1] = BASE64CHARSET;
   int index = 0, asciival = 0, computeval = 0, iplen = 0, rc = 0;

   iplen = strlen(input);
   while(index < iplen){
      asciival = (int)input[index];
      if(asciival == PADDINGCHAR){
         rc = decodeblock(decoderinput, output, oplen);
         break;
      }else{
         charval = strchr(encodingtabe, asciival);
         if(charval){
            decoderinput[computeval] = charval - encodingtabe;
            computeval = (computeval + 1) % 4;
            if(computeval == 0){
               rc = decodeblock(decoderinput, output, oplen);
               decoderinput[0] = decoderinput[1] =
               decoderinput[2] = decoderinput[3] = 0;
            }
         }
      }
      index++;
   }

   return rc;
}

int encodeblock(char *input, char *output, int oplen){
   int rc = 0, iplen = 0;
   char encodedstr[ENCODERLEN + 1] = "";
   char encodingtabe[TABLELEN + 1] = BASE64CHARSET;

   iplen = strlen(input);
   encodedstr[0] = encodingtabe[ input[0] >> 2 ];
   encodedstr[1] = encodingtabe[ ((input[0] & 0x03) << 4) |
                                 ((input[1] & 0xf0) >> 4) ];
   encodedstr[2] = (iplen > 1 ? encodingtabe[ ((input[1] & 0x0f) << 2) |
                                              ((input[2] & 0xc0) >> 6) ] : PADDINGCHAR);
   encodedstr[3] = (iplen > 2 ? encodingtabe[ input[2] & 0x3f ] : PADDINGCHAR);
   strncat(output, encodedstr, oplen-strlen(output));

   return rc;
}

int Base64Encode(char *input, char *output, int oplen){
   int rc = 0;
   int index = 0, ipindex = 0, iplen = 0;
   char encoderinput[ENCODERBLOCKLEN + 1] = "";

   iplen = strlen(input);
   while(ipindex < iplen){
      for(index = 0; index < 3; index++){
         if(ipindex < iplen){
            encoderinput[index] = input[ipindex];
         }else{
            encoderinput[index] = 0;
         }
         ipindex++;
      }
      rc = encodeblock(encoderinput, output, oplen);
   }

   return rc;
}

int main(int argc, char **argv) {
   int rc = 0;
   char encodedoutput[BUFFFERLEN + 1] = "";
   char decodedoutput[BUFFFERLEN + 1] = "";
   int i;



if(strcmp(argv[1],"-e")==0)
{
   encrypt(argv[2],encodedoutput );
   printf ("%s \n", encodedoutput);
}
if(strcmp(argv[1],"-d")==0)
{
   decrypt(argv[2],decodedoutput );
   printf ("%s \n", decodedoutput);
}

}

int encrypt(char *inputs, char encodedoutput[BUFFFERLEN + 1], char decodedoutput[BUFFFERLEN + 1]){
   char encodedoutput1[BUFFFERLEN + 1] = "";
   int i;
   int rc = 0;
   rc = Base64Encode(inputs, encodedoutput1, BUFFFERLEN);   
   for(i=0; i<strlen(encodedoutput1); i++)
   {
      encodedoutput1[i]=encodedoutput1[i]^key[i]; 
   }
   rc = Base64Encode(encodedoutput1, encodedoutput, BUFFFERLEN);
   return 0;
}


int decrypt(char *inputs, char encodedoutput[BUFFFERLEN + 1], char decodedoutput[BUFFFERLEN + 1]){
   char decodedoutput1[BUFFFERLEN + 1] = "";
   int i;
   int rc = 0;
   rc = Base64Decode(inputs, decodedoutput1, BUFFFERLEN);
   for(i=0; i<strlen(decodedoutput1); i++)
   {
      decodedoutput1[i]=decodedoutput1[i]^key[i]; 
   }
   rc = Base64Decode(decodedoutput1, decodedoutput, BUFFFERLEN);
   return 0;
}