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Displaying Source Code(s)
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File Encryption Program in C.
--------------------------------------------------------------------------------
Description : A not So simple program that demonstrates the
usage of
functions, points, arrays, and file I/O. Has one problem, will
leave a
random character at the end of the decrypted file, but other
than that, it
works fine.
/* 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<BR>);
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.<BR>);
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<BR>);
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.<BR>);
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!!!<BR>);
printf("Enter 1 to Encrypt / 2 to Decrypt<BR>);
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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123
Eng