Add files via upload

Author: izmanaveed

encryption.cpp

@@ -0,0 +1,45 @@
+#include<iostream>
+#include<string.h>
+#include<stdlib.h>
+#include<time.h>
+using namespace std;
+void encrypt (char x[]);
+void decrypt (char y[]);
+void R();
+int r;
+main()
+{
+	char a [100];
+	cout<<"Enter text to be encrypted"<<endl;
+	cin.getline(a,100);
+	cout<<"Key used for encryption will be: "<<endl;
+	R();
+	cout<<"The encrypted text is: "<<endl;
+	encrypt(a);
+	cout<<a<<endl;
+	cout<<"The decrypted text is:"<<endl;
+	decrypt(a);	
+	cout<<a<<endl;
+
+}
+void R()
+{
+	srand (time(NULL));
+	r=rand() %26+1;
+	cout<<r<<endl;
+}
+void encrypt(char x[])
+{
+	for (int i=0; x[i]!='\0'; i++)
+	{
+		x[i]=x[i]+r;
+	}
+}
+void decrypt (char y[])
+{
+	for (int j=0; y[j]!='\0'; j++)
+	{
+		y[j]=y[j]-r;
+	}
+}
+

final.cpp

@@ -0,0 +1,91 @@
+#include<iostream>
+#include<string.h>
+#include<stdlib.h>
+#include<time.h>
+#include<fstream>
+using namespace std;
+void encrypt (char x[],int l);
+void decrypt (char y[], int l);
+int read (char f[]);
+void R();
+int r;
+char s[100];
+main()
+{   
+	int L,a,sl;
+	cout<<"Press 1 to encrypt and decrypt file OR press 2 to encypt and decrypt text entered by user"<<endl;
+	cin>>a;
+   {
+	 if (a==1)
+    {
+    	char t[100];
+		cout<<"Enter file name you wish to encrypt"<<endl;
+		cin>>t;
+		cout<<"Key used for encryption will be: "<<endl;
+		R();		
+		L=read(t);
+		cout<<"Length of this text file is: "<<L-1<<endl;
+		encrypt(s,L);
+		decrypt(s,L);
+}
+	if (a==2)
+	{
+	char u[100];
+	cout<<"Enter text you wish to encrypt: "<<endl;
+	cin>>u;
+	cout<<"Key used for encryption will be: "<<endl;
+	R();	
+	encrypt(s,L);
+	decrypt(s,L);
+	}
+}
+}
+void R()
+{
+	srand (time(NULL));
+	r=rand() %26+1;
+	cout<<r<<endl;
+}
+int read(char f[])
+{	
+	int i=0;
+	int len=0;
+	ifstream myfile (f);
+	if (myfile.is_open()) 
+	{ 
+	myfile>>noskipws;
+	 while ( !myfile.eof())
+          {
+                myfile >> s[i];
+                cout<<s[i];
+                i++;
+				len++; 
+    }
+	cout<<endl;
+	}
+	else  
+	{
+	cout << "File does not exist"<<endl;
+	exit (1);
+}
+	return len;
+}
+
+void encrypt(char x[], int l)
+{
+	for (int i=0; i<=l; i++)
+	{
+		x[i]=x[i]+r;
+	}
+	cout<<"Encrypted Text is"<<endl;
+	cout<<x<<endl;
+}
+void decrypt (char y[], int l)
+{
+	for (int j=0; j<=l; j++)
+	{
+		y[j]=y[j]-r;
+	}
+	cout<<"Decrypted Text is"<<endl;
+	cout<<y<<endl;
+}