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File Encryption Program in C.




WARNING : 
                             do not give the have the same sourcefile and
                             destinationfile, encrypting or decrypting, this bug will be worked
                     out as i get more interested in file encryption

#include <stdio.h>

#define ENCRYPTION_FORMULA  (int) Byte + 25
#define DECRYPTION_FORMULA  (int) Byte - 25

int Encrypt(char * FILENAME, char * NEW_FILENAME)
{
//printf("Loaded Encrypt
");
FILE *inFile;  //Declare inFile
FILE *outFile;  //Declare outFile

char Byte;
char newByte;
int n;


printf("1");
int i=0;

inFile = fopen(FILENAME,"rb");
outFile = fopen(NEW_FILENAME, "w");

if(inFile==NULL)
printf("Error: Can't Open inFile");

if(outFile==NULL)
{
printf("Error: Can't open outFile.
");
return 1;
}
else
{

printf("File Opened, Encrypting");
while(1)
{
printf(".");


if(Byte!=EOF)
{
Byte=fgetc(inFile);
// printf("%d",Byte);
newByte=Byte+25;

fputc(newByte,outFile);

}

else
{
printf("
End of File");
break;
}
}
fclose(inFile);
fclose(outFile);

}
}

int Decrypt (char *FILENAME, char *NEW_FILENAME)
{
//printf("Loaded Decrypt
");
FILE *inFile; //Declare inFile
FILE *outFile;       //Declare outFile

char Byte;
char newByte;
printf("2");
int i=0;

inFile = fopen(FILENAME,"rb");
outFile = fopen(NEW_FILENAME, "w");

if(inFile==NULL)
printf("Error: Can't Open inFile");

if(outFile==NULL)
{
printf("Error: Can't open outFile.
");
return 1;
}
else
{

printf("File Opened, Decrypting");
while(1)
{
printf(".");


if(Byte!=EOF)
{
Byte=fgetc(inFile);
// printf("%d",Byte);
newByte=Byte-25;

fputc(newByte,outFile);

}

else
{
printf("
End of File");
break;
}
}
fclose(inFile);
fclose(outFile);

}
}

int main()
{
char encFile[200];
char newencFile[200];
char decFile[200];
char newdecFile[200];

int choice;

printf("NOTE: you must Decrypt the file with the same file
extension!!!
");
printf("Enter 1 to Encrypt  / 2 to Decrypt
");
scanf("%d",&choice);

switch(choice)
{
case 1:
printf("Enter the Source Filename:  ");
scanf("%s",&encFile);
printf("Enter the Destination Filename:   ");
scanf("%s",&newencFile);
Encrypt(encFile, newencFile);
break;
case 2:
printf("Enter the Source Filename:   ");
scanf("%s",&decFile);
printf("Enter the Destination Filename:   ");
scanf("%s",&newdecFile);
Decrypt(decFile, newdecFile);
break;

}

return 0;
}


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