Método Node.js tlsSocket.getCipher()

El método tlsSocket.getCipher() es una interfaz de programación de aplicaciones incorporada de la clase TLSSocket dentro del módulo tls que se utiliza para devolver objetos que contienen información sobre el conjunto de cifrado negociado.

Sintaxis:

const tlsSocket.getCipher()

Parámetros: Este método no acepta ningún parámetro.

Valor devuelto: este método devuelve un objeto que contiene información sobre el conjunto de cifrado negociado.

¿Cómo generar claves privadas y certificados públicos ? 

• Clave privada  
  Paso 1: abra el bloc de notas y copie y pegue la siguiente clave: 

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

• Paso 2: Guardar como clave privada.pem 
   
• Certificado público  
  Paso 1: abra el bloc de notas y copie y pegue la siguiente clave: 

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

• Paso 2: Guardar como public-cert.pem 

Ejemplo 1: Nombre de archivo: index.js 

// Node.js program to demonstrate the
// tlsSocket.getCipher() method
var 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
var options = {
  key: fs.readFileSync('private-key.pem'),
  cert: fs.readFileSync('public-cert.pem'),
  rejectUnauthorized: false
};
 
// Creating and initializing server
var 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
var client = tls.connect(PORT, HOST,
               options, function() {
   
  // Getting local cipher object by
  // using tlsSocket.getCipher() method
  value = client.getCipher();
 
  client.write("Cipher : " + value.name);
   
  client.end(() => {
    console.log("Client closed successfully");
  });
});

Producción:

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

Received: Cipher : TLS_AES_256_GCM_SHA384
Server closed successfully

Ejemplo 2: Nombre de archivo: index.js

// Node.js program to demonstrate the
// tlsSocket.getCipher() method
var 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
var options = {
    key: fs.readFileSync('private-key.pem'),
    cert: fs.readFileSync('public-cert.pem'),
    rejectUnauthorized: false
};
 
// Creating and initializing server
var server = tls.createServer(options,
    function (socket) {
 
        // Getting local cipher object
        // by using tlsSocket.getCipher() method
        value = socket.getCipher();
 
        socket.write("Cipher : " + value.name);
 
        // 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
var 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")
    });
});

Ejecute el archivo index.js con el siguiente comando:

node index.js

Producción:

I'm listening at 127.0.0.1, on port 1337
client is connected
Received: Cipher : TLS_AES_256_GCM_SHA384
client closed successfully
Server closed successfully

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