Create the Directory Structure Create the following directory structure:

arduino Copy code contacto/ ├── config/ │ └── db.js ├── models/ │ └── Contact.js ├── routes/ │ ├── auth.js │ ├── contact.js ├── middleware/ │ └── auth.js ├── utils/ │ ├── encryption.js ├── .env └── server.js 3. Configure MongoDB Connection config/db.js:

js

const mongoose = require('mongoose'); require('dotenv').config();

const connectDB = async () => { try { await mongoose.connect(process.env.MONGO_URI, { useNewUrlParser: true, useUnifiedTopology: true, }); console.log('MongoDB connected...'); } catch (err) { console.error(err.message); process.exit(1); } };

module.exports = connectDB; 4. Define the Contact Model models/Contact.js:

js

const mongoose = require('mongoose');

const ContactSchema = new mongoose.Schema({ name: { type: String, required: true }, phone: { type: Number, required: true }, email: { type: String, default: null }, linkedin: { type: String, default: null }, twitter: { type: String, default: null } });

module.exports = mongoose.model('Contact', ContactSchema); 5. Create Middleware for Authentication middleware/auth.js:

js

const jwt = require('jsonwebtoken'); require('dotenv').config();

module.exports = function (req, res, next) { const token = req.header('x-auth-token'); if (!token) { return res.status(401).json({ msg: 'No token, authorization denied' }); }

try { const decoded = jwt.verify(token, process.env.JWT_SECRET); req.user = decoded.user; next(); } catch (err) { res.status(401).json({ msg: 'Token is not valid' }); } }; 6. Create Utility Functions for Encryption utils/encryption.js:

js

const crypto = require('crypto'); require('dotenv').config();

const algorithm = 'aes-256-cbc'; const key = crypto.randomBytes(32); const iv = crypto.randomBytes(16);

const encrypt = (text) => { let cipher = crypto.createCipheriv(algorithm, Buffer.from(key), iv); let encrypted = cipher.update(text); encrypted = Buffer.concat([encrypted, cipher.final()]); return { iv: iv.toString('hex'), encryptedData: encrypted.toString('hex') }; };

const decrypt = (text) => { let iv = Buffer.from(text.iv, 'hex'); let encryptedText = Buffer.from(text.encryptedData, 'hex'); let decipher = crypto.createDecipheriv(algorithm, Buffer.from(key), iv); let decrypted = decipher.update(encryptedText); decrypted = Buffer.concat([decrypted, decipher.final()]); return decrypted.toString(); };

module.exports = { encrypt, decrypt }; 7. Define the Routes routes/auth.js:

js

const express = require('express'); const jwt = require('jsonwebtoken'); const bcrypt = require('bcryptjs'); require('dotenv').config();

const router = express.Router();

// Dummy credentials const dummyUser = { username: 'saltman', password: bcrypt.hashSync('oai1122', 10) };

// Login API router.post('/login', (req, res) => { const { username, password } = req.body;

if (username !== dummyUser.username) { return res.status(400).json({ msg: 'Invalid credentials' }); }

const isMatch = bcrypt.compareSync(password, dummyUser.password); if (!isMatch) { return res.status(400).json({ msg: 'Invalid credentials' }); }

const payload = { user: { id: dummyUser.username } };

jwt.sign(payload, process.env.JWT_SECRET, { expiresIn: '1h' }, (err, token) => { if (err) throw err; res.json({ token }); }); });

module.exports = router; routes/contact.js:

js

const express = require('express'); const { v4: uuidv4 } = require('uuid'); const auth = require('../middleware/auth'); const Contact = require('../models/Contact'); const { encrypt, decrypt } = require('../utils/encryption');

const router = express.Router();

// Create contact API router.post('/create', auth, async (req, res) => { const { name, phone, email, linkedin, twitter } = req.body;

const newContact = new Contact({ id: uuidv4(), name: encrypt(name).encryptedData, phone: encrypt(phone.toString()).encryptedData, email: email ? encrypt(email).encryptedData : null, linkedin: linkedin ? encrypt(linkedin).encryptedData : null, twitter: twitter ? encrypt(twitter).encryptedData : null });

try { const contact = await newContact.save(); res.json({ msg: 'Contact created successfully', contact }); } catch (err) { res.status(500).json({ msg: 'Server error' }); } });

// Edit contact API router.put('/edit', auth, async (req, res) => { const { name, email, linkedin, twitter } = req.body;

try { let contact = await Contact.findOne({ name: encrypt(name).encryptedData }); if (!contact) { return res.status(404).json({ msg: 'Contact not found' }); }

if (email) contact.email = encrypt(email).encryptedData;
if (linkedin) contact.linkedin = encrypt(linkedin).encryptedData;
if (twitter) contact.twitter = encrypt(twitter).encryptedData;

await contact.save();
res.json({ msg: 'Contact updated successfully', contact });

} catch (err) { res.status(500).json({ msg: 'Server error' }); } });

// Search contact API router.post('/search', auth, async (req, res) => { const { search_token } = req.body;

try { let contacts = await Contact.find(); contacts = contacts.filter(contact => decrypt(contact.name).includes(search_token)); if (contacts.length === 0) { return res.status(404).json({ msg: 'No contacts found' }); }

res.json(contacts.map(contact => ({
    id: contact.id,
    name: decrypt(contact.name),
    phone: decrypt(contact.phone),
    email: contact.email ? decrypt(contact.email) : null,
    linkedin: contact.linkedin ? decrypt(contact.linkedin) : null,
    twitter: contact.twitter ? decrypt(contact.twitter) : null
})));

} catch (err) { res.status(500).json({ msg: 'Server error' }); } });

module.exports = router; 8. Create the Main Server File server.js:

js

const express = require('express'); const connectDB = require('./config/db'); const bodyParser = require('body-parser'); require('dotenv').config();

const app = express();

// Connect to database connectDB();

// Middleware app.use(bodyParser.json());

// Routes app.use('/api/auth', require('./routes/auth')); app.use('/api/contact', require('./routes/contact'));

const PORT = process.env.PORT || 5000;

app.listen(PORT, () => console.log(Server started on port ${PORT})); 9. Environment Variables .env:

makefile

MONGO_URI=your_mongodb_atlas_connection_string JWT_SECRET=as2809 10. Testing with Postman Login API: Send a POST request to http://localhost:5000/api/auth/login with JSON body:

json

{ "username": "saltman", "password": "oai1122" }

json

{ "name": "Billy Butcher", "phone": 144888, "email": null, "linkedin": null, "twitter": null } I

json

{ "name": "Billy Butcher", "twitter": "anti_vought01" }