Create dh.cpp

dh.cpp

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+// DeffieHellman.cpp
+//8-13-19
+//Tyler Perkins
+//Basic client server implementation of DH Key exchange
+//Not secure in the slightest, just a POC
+//Despagettified 8-22-19
+
+#include <iostream>
+#include <math.h>
+#include <cstdlib>
+#include <time.h>
+
+using namespace std;
+
+class server {
+//this is the server, he just genorates the public values and thats it
+public:
+	int g, n;
+	int otherKey;
+
+	server() {
+		//make the public values g and n, and create our private value
+		cout << "Constructing Server..." << endl;
+		//make n
+		srand(time(NULL));
+		n = rand();
+		cout << "n is " << n << endl;
+
+		//make g
+		g = primeGen();
+		cout << "g is " << g << endl;
+
+		//genorate a non zero private value
+		while (true) {
+			privateServerKey = rand() % n;
+			if (privateServerKey != 0) {
+				break;
+			}
+		}
+		cout << "SERVER private value is " << privateServerKey << endl;
+	}
+
+	~server() {
+		cout << "Deconstructing Server..." << endl;
+
+	}
+	
+	//retreive values from the client
+	void getValue(int type, int value) {
+		//key: 1 - otherprivatekey
+		//2 - compiled key
+
+		switch (type) {
+		case 1:
+			//otherprivatekey
+			forignServerValue = value;
+		case 2:
+			//final value
+			finalValue = value;
+		}
+		cout << "SERVER received value" << endl;
+	}
+
+	//compute first value "otherkey"
+	int findOtherKey() {
+		otherKey = (g ^ privateServerKey) % n;
+		cout << "SERVER otherkey is " << otherKey << endl;
+		return otherKey;
+	}
+
+	int findFinalValue() {
+		finalValue = (forignServerValue ^ privateServerKey) % n;
+		cout << "SERVER final shared secret is " << finalValue << endl;
+		return finalValue;
+	}
+
+private:
+	int maxKey = 200;
+	int privateServerKey;
+	int finalValue;
+	int forignServerValue;
+
+	int primeGen() {
+
+		while (true) {
+			srand(time(NULL));
+			int randomNumber = (rand() % maxKey);
+			bool isPrime = true;
+
+			//check for prime number
+			for (int i = 2; i <= randomNumber / 2; ++i) {
+
+				//this will catch nonprimes
+				if (randomNumber % i == 0 || randomNumber == 0 ) {
+
+					isPrime = false;
+				}
+				//all else will loop till the for loop ends which confirms a prime number
+			}
+
+			if (isPrime) {
+				return randomNumber;
+			}
+			
+		}
+		//this should never be reached
+		return 0;
+	}
+};
+
+class client {
+//this is the client machine will be not genorating the numbers but just connects to the server
+public:
+	int g, n;
+	int otherKey;
+	client(int g1, int n1) {
+		//receive the 2 public numbers, g and n, and create our private key
+		srand(time(NULL));
+		cout << "Constructing Client..." << endl;
+		g = g1;
+		n = n1;
+		//cout << "client received g as " << g << endl;
+		//cout << "client received n as " << n << endl;
+
+		//genorate a non zero private value
+		while (true) {
+			privateServerKey = rand() % n;
+			if (privateServerKey != 0) {
+				break;
+			}
+		}
+		cout << "CLIENT private value is " << privateServerKey << endl;
+	}
+
+	~client() {
+		cout << "Deconstructing Client..." << endl;
+
+	}
+
+	//retreive values from server
+	void getValue(int type, int value) {
+		//key: 1 - otherprivatekey
+		//2 - compiled key
+
+		switch (type) {
+			case 1:
+				//otherprivatekey
+				forignServerValue = value;
+			case 2:
+				//final value
+				finalValue = value;
+		}
+		cout << "CLIENT received value" << endl;
+	}
+	
+	//compute first value "otherkey"
+	int findOtherKey() {
+		otherKey = (g ^ privateServerKey) % n;
+		cout << "CLIENT othervalue is " << otherKey << endl;
+		return otherKey;
+	}
+
+	int findFinalValue() {
+		finalValue = (forignServerValue ^ privateServerKey) % n;
+		cout << "CLIENT final shared secret is " << finalValue << endl;
+		return finalValue;
+	}
+	
+
+private:
+	int privateServerKey;
+	int forignServerValue;
+	int finalValue;
+};
+
+int main(int argc, char **argv)
+{
+    //declare vars
+
+	//create 2 objects, client and server
+	server testServer;
+	//pass g and n to the client. these are public information
+	client testClient(testServer.g,testServer.n);
+
+	//g, n, a, and b are all made; calculate otherkey, or A and B, then send them
+	//give client its otherkey
+	testClient.getValue(1, testServer.findOtherKey());
+	testServer.getValue(1, testClient.findOtherKey());
+
+	//calculate shared secret
+	testClient.findFinalValue();
+	testServer.findFinalValue();
+
+	return 0;
+}