Skip to main content

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;
}


Popular posts from this blog

Putimage function in c

putimage function outputs a bit image onto the screen. Declaration:- void putimage(int left, int top, void *ptr, int op); putimage puts the bit image previously saved with getimage back onto the screen, with the upper left corner of the image placed at (left, top). ptr points to the area in memory where the source image is stored. The op argument specifies a operator that controls how the color for each destination pixel on screen is computed, based on pixel already on screen and the corresponding source pixel in memory. c smiling face animation This animation using c draws a smiling face which appears at random position on screen. See output below the code, it will help you in understanding the code easily. C programming code #include<graphics.h> #include<conio.h> #include<stdlib.h>   main() { int gd = DETECT, gm, area, temp1, temp2, left = 25, top = 75; void *p;   initgraph(&gd,&gm,"C:\\TC\\BGI");   setcolor(YELLOW)...

What are selection statements in C++ ? If and Switch

There are several statements that we can use in C++ programming that help in choosing a set of instructions for using the code depending upon an expression truth value.  What are Selection Statements in C++? As mentioned above there are several statements that we can use to choose a set of pre-defined instructions within a program in any section of the program as per the need. These are called selection statements in C++  In C++ Program there are two types of Selection statements  1. If  2. Switch  The If Statement of C++ To understand "if statement" let's look at an example.  Example - If you have 10 rupees then you can buy the chocolate.  Here, there is a condition in buying chocolate, if you have 10 rupees then only you can buy it.  This shows that the If is a condition which can be true or false, If it is false it won't be executed, in this example, if you don't have 10 rupees i.e. the condition is false you cant buy the chocolate.  So, I...

C++ Program to find the sum, difference, product and quotient of two integers

#include <iostream.h> #include <conio.h> void main() {   clrscr();   int x = 10;   int y = 2;   int sum, difference, product, quotient;   sum = x + y;   difference = x - y;   product = x * y;   quotient = x / y;   cout << "The sum of " << x << " & " << y << " is " << sum << "." << endl;   cout << "The difference of " << x << " & " << "y <<  is " << difference << "." << endl;   cout << "The product of " << x << " & " << y << " is " << product << "." << endl;   cout << "The quotient of " << x << " & " << y << " is " << quotient << "." << endl;   getch(); }