Node.js tls.getCiphers() Method

The tls.getCiphers() is an inbuilt application programming interface of class TLS within tls module which is used to return the array of the supported TLS ciphers.

Syntax:

const tls.getCiphers()

Parameters: This method does not accept any parameter.

Return Value: This method returns the array of the supported TLS ciphers.

How to generate a Private key and Public certificate?

• Private key: Open Notepad and copy and paste the following key:  

-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----

• Now save the filename as a private key.pem
• Public certificate: Open Notepad and copy and paste the following key:  

-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

• Now save the filename as public-cert.pem

Example 1: Filename: index.js

javascript

// Node.js program to demonstrate the
// tls.getCiphers() method
const tls = require('tls'),
    fs = require('fs'),

    // Port and host address for server
    PORT = 1337,
    HOST = '127.0.0.1',
    value = null;

// Private key and public certificate for access
const options = {
    key: fs.readFileSync('private-key.pem'),
    cert: fs.readFileSync('public-cert.pem'),
    rejectUnauthorized: false
};

// Creating and initializing server
const server = tls.createServer(options, function (socket) {

    // Print the data that we received
    socket.on('data', function (data) {
        console.log('\nReceived: %s ',
            data.toString().replace(/(\n)/gm, ""));
    });

    // Stopping the server
    // by using the close() method
    server.close(() => {
        console.log("Server closed successfully");
    });
});

// Start listening on a specific port and address
// by using listen() method
server.listen(PORT, HOST, function () {
    console.log("I'm listening at %s, on port %s", HOST, PORT);
});

// Creating and initializing client
const client = tls.connect(PORT, HOST, options, function () {

    // Getting list of cipher
    // by using tls.getCiphers() method
    value = tls.getCiphers();

    client.write(" Cipher : " + value[12]);

    client.end(() => {
        console.log("Client closed successfully");
    });
});

Run the index.js file using the following command:

node index.js

Output:

I'm listening at 127.0.0.1, on port 1337
Client closed successfully

Received:  Cipher : dhe-psk-chacha20-poly1305
Server closed successfully

Example 2: Filename: index.js

javascript

// Node.js program to demonstrate the
// tls.getCiphers() method
const tls = require('tls'),
    fs = require('fs'),

    // Port and host address for server
    PORT = 1337,
    HOST = '127.0.0.1';

// Private key and public certificate for access
const options = {
    key: fs.readFileSync('private-key.pem'),
    cert: fs.readFileSync('public-cert.pem'),
    rejectUnauthorized: false
};

// Creating and initializing server
const server = tls.createServer(options, function (socket) {

    // Getting list of cipher
    // by using tls.getCiphers() method
    value = tls.getCiphers();

    socket.write(" Cipher : " + value[12]);

    // Stopping the server
    // by using the close() method
    server.close(() => {
        console.log("Server closed successfully")
    });
});

// Start listening on a specific port and address
// by using listen() method
server.listen(PORT, HOST, function () {
    console.log("I'm listening at %s, on port %s", HOST, PORT);
});

// Creating and initializing client
const client = tls.connect(PORT, HOST, options, function () {
    console.log("client is connected");
});

client.on("data", function (data) {

    console.log('Received: %s',
        data.toString().replace(/(\n)/gm, ""));

    // Close the connection after receiving the message
    client.end(() => {
        console.log("client closed successfully")
    });
});

Run the index.js file using the following command:

node index.js

Output:

I'm listening at 127.0.0.1, on port 1337
client is connected
Received:  Cipher : dhe-psk-chacha20-poly1305
client closed successfully
Server closed successfully

Reference: https://nodejs.org/dist/latest-v12.x/docs/api/tls.html#tls_tls_getciphers