The server.addContext() is an inbuilt application programming interface of class Socket within tls module which is used to add the security context for the use of the client.
Syntax:
server.addContext(hostname, context)
Parameters: This method takes the following argument as a parameter:
- hostname: A server name indicating hostname.
- context: Any of the properties from the tls.createSecureContext() options arguments.
Return Value: This method does not return any value.
How to generate private keys and public certificates?
Private key: Open Notepad and copy and paste the following key:
-----BEGIN RSA PRIVATE KEY----- MIICXQIBAAKBgQC38R9wXcUbhOd44FavgmE5R3K4JeYOHLnI7dUq1B8/Gv7l3SOg JKef/m9gM1KvUx951mapXGtcWgwB08J3vUE2YOZ4tWJArrVZES0BI/RmFAyhQFP5 HcWl3LSM9LRihP98F33oIkKaCxA5LxOrkgpV4HrUzIKTABDYah7RPex1WQIDAQAB AoGBAIXR71xxa9gUfc5L7+TqBs+EMmrUb6Vusp8CoGXzQvRHMJCMrMFySV0131Nu o0YYRDsAh1nJefYLMNcXd1BjqI+qY8IeRsxaY+9CB2KKGVVDO2uLdurdC2ZdlWXT Vwr3dDoyR0trnXJMmH2ijTeO6bush8HuXxvxJBjvEllM5QYxAkEA3jwny9JP+RFu 0rkqPBe/wi5pXpPl7PUtdNAGrh6S5958wUoR4f9bvwmTBv1nQzExKWu4EIp+7vjJ fBeRZhnBvQJBANPjjge8418PS9zAFyKlITq6cxmM4gOWeveQZwXVNvav0NH+OKdQ sZnnDiG26JWmnD/B8Audu97LcxjxcWI8Jc0CQEYA5PhLU229lA9EzI0JXhoozIBC TlcKFDuLm88VSmlHqDyqvF9YNOpEdc/p2rFLuZS2ndB4D+vu6mjwc5iZ3HECQCxy GBHRclQ3Ti9w76lpv+2kvI4IekRMZWDWnnWfwta+DGxwCgw2pfpleBZkWqdBepb5 JFQbcxQJ0wvRYXo8qaUCQQCgTvWswBj6OTP7LTvBlU1teAN2Lnrk/N5AYHZIXW6m nUG9lYvH7DztWDTioXMrruPF7bdXfZOVJD8t0I4OUzvC -----END RSA PRIVATE KEY-----
Save the file as a private key.pem
Public certificate: Open Notepad and copy and paste the following key:
-----BEGIN CERTIFICATE----- MIICfzCCAegCCQDxxeXw914Y2DANBgkqhkiG9w0BAQsFADCBgzELMAkGA1UEBhMC SU4xEzARBgNVBAgMCldlc3RiZW5nYWwxEDAOBgNVBAcMB0tvbGthdGExFDASBgNV BAoMC1BhbmNvLCBJbmMuMRUwEwYDVQQDDAxSb2hpdCBQcmFzYWQxIDAeBgkqhkiG 9w0BCQEWEXJvZm9mb2ZAZ21haWwuY29tMB4XDTIwMDkwOTA1NTExN1oXDTIwMTAw OTA1NTExN1owgYMxCzAJBgNVBAYTAklOMRMwEQYDVQQIDApXZXN0YmVuZ2FsMRAw DgYDVQQHDAdLb2xrYXRhMRQwEgYDVQQKDAtQYW5jbywgSW5jLjEVMBMGA1UEAwwM Um9oaXQgUHJhc2FkMSAwHgYJKoZIhvcNAQkBFhFyb2ZvZm9mQGdtYWlsLmNvbTCB nzANBgkqhkiG9w0BAQEFAAOBjQAwgYkCgYEAt/EfcF3FG4TneOBWr4JhOUdyuCXm Dhy5yO3VKtQfPxr+5d0joCSnn/5vYDNSr1MfedZmqVxrXFoMAdPCd71BNmDmeLVi QK61WREtASP0ZhQMoUBT+R3Fpdy0jPS0YoT/fBd96CJCmgsQOS8Tq5IKVeB61MyC kwAQ2Goe0T3sdVkCAwEAATANBgkqhkiG9w0BAQsFAAOBgQATe6ixdAjoV7BSHgRX bXM2+IZLq8kq3s7ck0EZrRVhsivutcaZwDXRCCinB+OlPedbzXwNZGvVX0nwPYHG BfiXwdiuZeVJ88ni6Fm6RhoPtu2QF1UExfBvSXuMBgR+evp+e3QadNpGx6Ppl1aC hWF6W2H9+MAlU7yvtmCQQuZmfQ== -----END CERTIFICATE-----
Save the file as public-cert.pem
Example 1: Filename: index.js
// Node.js program to demonstrate the // server.addContext() 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) {
// Print the data that we received
socket.on( "data" , function (data) {
console.log( '\nReceived: %s ' ,
data.toString().replace(/(\n)/gm, "" ));
});
});
// Adding context into the server server.addContext( '127.0.0.2' , options.key);
console.log( "context is added" );
// Start listening on a specific // port and address server.listen(PORT, HOST, function () {
console.log( "I'm listening at %s, "
+ "on port %s" , HOST, PORT);
}); // When an error occurs, show it. server.on( "error" , function (error) {
console.error(error);
// Close the connection after the
// error occurred.
// server.destroy();
}); server.on( "end" , () => {
server.end();
//server.destroy();
}) // Creating and initializing client const client = tls.connect(PORT, HOST, options, function () {
// Check if the authorization worked
if (client.authorized) {
console.log( "Connection authorized"
+ " by a Certificate Authority." );
} else {
console.log( "Connection not authorized: "
+ client.authorizationError)
}
// Send a friendly message
client.write(
"I am the client sending you a message." );
client.end();
});
client.on( "close" , function () {
console.log( "Connection closed" );
}); // When an error occurs, show it. client.on( "error" , function (error) {
console.error(error);
// Close the connection after
// the error occurred.
client.destroy();
}); |
Output:
context is added I'm listening at 127.0.0.1, on port 1337 Connection not authorized: DEPTH_ZERO_SELF_SIGNED_CERT Received: I am the client sending you a message. Connection closed
Example 2: Filename: index.js
// Node.js program to demonstrate the // server.addcontext() 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) {
// Print the data that we received
socket.on( 'data' , function (data) {
console.log( '\nReceived: %s ' ,
data.toString()
.replace(/(\n)/gm, "" ));
});
});
// Adding context into the server // by using addContext() method server.addContext( '127.0.0.2' , options.key);
console.log( "context is added" );
// Start listening on a specific // port and address 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 () {
// Send a friendly message
client.write( "I am the client "
+ "sending you a message." );
client.end();
});
|
Run the index.js file using the following command:
node index.js
Output:
context is added I'm listening at 127.0.0.1, on port 1337 Received: I am the client sending you a message.
Reference: https://nodejs.org/dist/latest-v12.x/docs/api/tls.html#tls_server_addcontext_hostname_context