(Node.js) FTP Connect, Examine Server Certificate, and then Authenticate

Demonstrates how to connect to an FTP server, examine the server's SSL/TLS certificate, and then, if it meets the application's security requirements, proceed to authenticate.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

    // This example assumes Chilkat Ftp2 to have been previously unlocked.
    // See Unlock Ftp2 for sample code.

    var ftp = new chilkat.Ftp2();

    ftp.Hostname = "www.authtls-ftps-server.com";
    ftp.Username = "FTP_LOGIN";
    ftp.Password = "FTP_PASSWORD";
    ftp.AuthTls = true;
    ftp.Port = 21;

    // Connect to the FTP server using explicit TLS (AUTH TLS).
    var success = ftp.ConnectOnly();
    if (success !== true) {
        console.log(ftp.LastErrorText);
        return;
    }

    // Get the FTP server's certificate.
    // serverCert: Cert
    var serverCert = ftp.GetSslServerCert();
    if (ftp.LastMethodSuccess !== true) {
        console.log(ftp.LastErrorText);
        return;
    }

    // Now that we have the certificate, we can check it in any way we desire.
    // (See the online reference documentation for the certificate object's methods
    // and properties)...

    // Assuming the certificate is OK, proceed to authenticate with the FTP server.
    success = ftp.LoginAfterConnectOnly();
    if (success !== true) {
        console.log(ftp.LastErrorText);
        return;
    }

    // 
    // Proceed with uploading/download files, etc...
    // 

    ftp.Disconnect();
    console.log("Success.");

}

chilkatExample();