main.cpp

#include <iostream>
#include <string>
#include <chrono>
#include "RSA.h"

using namespace std;
using namespace std::chrono;

int main() {
    cout << "=== RSA Algorithm Implementation ===" << endl << endl;
    
    // Test key generation with different bit lengths
    vector<int> testBitLengths = {128, 256, 512, 768, 1024, 2048, 4096};
    
    cout << "=== Parallel RSA Key Generation Performance Test ===" << endl;
    cout << "Using multi-threading for parallel prime generation (p and q generated simultaneously)" << endl << endl;
    
    for (int bitLength : testBitLengths) {
        cout << "Testing RSA-" << bitLength << " key generation..." << endl;
        
        // Actual test run
        // auto start = high_resolution_clock::now();
        
        try {
            auto start = high_resolution_clock::now();
            RSA::KeyPair keys = RSA::generateKeyPair(bitLength);
            
            auto end = high_resolution_clock::now();
            auto duration = duration_cast<milliseconds>(end - start);
            
            cout << "✓ Key generation completed in " << duration.count() << " ms" << endl;
            if (duration.count() < 1000) {
                cout << "  (Performance target: < 1000 ms for RSA-768) ✓" << endl;
            }
            BigInteger n_copy = keys.n;
            BigInteger e_copy = keys.e;
            BigInteger d_copy = keys.d;
            cout << "Public Key (n): " << string(n_copy) << endl;
            cout << "Public Exponent (e): " << string(e_copy) << endl;
            string d_str = string(d_copy);
            cout << "Private Exponent (d): " << d_str.substr(0, min(50, (int)d_str.length())) << "..." << endl;
            cout << endl;
            
            // Test encryption and decryption
            string testMessage = "Hello, RSA! This is a test message for RSA encryption.";
            cout << "Original message: " << testMessage << endl;
            
            string encrypted = RSA::encrypt(testMessage, keys.n, keys.e);
            cout << "Encrypted: " << encrypted.substr(0, 100) << "..." << endl;
            
            string decrypted = RSA::decrypt(encrypted, keys.n, keys.d);
            cout << "Decrypted: " << decrypted << endl;
            
            if (decrypted == testMessage) {
                cout << "✓ Encryption/Decryption test PASSED" << endl;
            } else {
                cout << "✗ Encryption/Decryption test FAILED" << endl;
            }
            cout << endl;
            
            // Test digital signature
            string messageToSign = "This is a message to sign.";
            cout << "Message to sign: " << messageToSign << endl;
            
            string signature = RSA::sign(messageToSign, keys.n, keys.d);
            cout << "Signature: " << signature.substr(0, 100) << "..." << endl;
            
            bool verified = RSA::verify(messageToSign, signature, keys.n, keys.e);
            if (verified) {
                cout << "✓ Signature verification PASSED" << endl;
            } else {
                cout << "✗ Signature verification FAILED" << endl;
            }
            
            // Test with wrong message
            bool wrongVerified = RSA::verify("Wrong message", signature, keys.n, keys.e);
            if (!wrongVerified) {
                cout << "✓ Signature verification (wrong message) correctly REJECTED" << endl;
            } else {
                cout << "✗ Signature verification (wrong message) incorrectly ACCEPTED" << endl;
            }
            
        } catch (const exception& e) {
            cout << "Error: " << e.what() << endl;
        }
        
        cout << "\n" << string(60, '-') << "\n\n";
    }
    
    // Test with user input
    cout << "Enter a message to encrypt (or press Enter to skip): ";
    string userMessage;
    getline(cin, userMessage);
    
    if (!userMessage.empty()) {
        cout << "\nGenerating keys for your message..." << endl;
        auto start = high_resolution_clock::now();
        RSA::KeyPair userKeys = RSA::generateKeyPair(768);
        auto end = high_resolution_clock::now();
        auto duration = duration_cast<milliseconds>(end - start);
        
        cout << "Keys generated in " << duration.count() << " ms" << endl;
        
        string encrypted = RSA::encrypt(userMessage, userKeys.n, userKeys.e);
        cout << "Encrypted message: " << encrypted << endl;
        
        string decrypted = RSA::decrypt(encrypted, userKeys.n, userKeys.d);
        cout << "Decrypted message: " << decrypted << endl;
        
        string signature = RSA::sign(userMessage, userKeys.n, userKeys.d);
        cout << "Digital signature: " << signature << endl;
        
        bool verified = RSA::verify(userMessage, signature, userKeys.n, userKeys.e);
        cout << "Signature verified: " << (verified ? "Yes" : "No") << endl;
    }
    
    return 0;
}