Verify FTP SSL Server Certificate

This example demonstrates how to verify the FTP server's certificate and authenticity. The intent is to verify the authenticity of the server before passing a login/password to it.

Download 32-bit Chilkat FTP2 ActiveX (.msi)

Download All 32-bit Chilkat ActiveX Components (.zip)

Download All 64-bit Chilkat ActiveX Components (.zip)

<?php

$ftp = new COM("Chilkat.Ftp2");

//  Any string unlocks the component for the 1st 30-days.
$success = $ftp->UnlockComponent('Anything for 30-day trial');
if ($success != true) {
    print $ftp->lastErrorText() . "\n";
    exit;
}

$ftp->Hostname = 'ftp.myftpserver.com';
$ftp->Username = 'myUsername';
$ftp->Password = 'myPassword';

//  Establish an AUTH SSL secure channel after connection
//  on the standard FTP port 21.
$ftp->AuthSsl = true;

//  The Ssl property is for establishing an implicit SSL connection
//  on port 990.  Do not set it.
$ftp->Ssl = false;

//  Indicate that the FTP server must have a verifiable SSL certificate.
//  Do not accept self-signed certs or certificates that are
//  expired, revoked, or cannot be verified to a root authority:
$ftp->RequireSslCertVerify = true;

//  You may also set a requirement.  In this example,
//  the certificate's Common Name (CN) must match the
//  required string exactly:
$ftp->SetSslCertRequirement('subjectcn','Chilkat Software, Inc.');

//  Connect and login to the FTP server.
$success = $ftp->Connect();
if ($success != true) {
    print $ftp->lastErrorText() . "\n";
    exit;
}
else {
    //  LastErrorText contains information even when
    //  successful. This allows you to visually verify
    //  that the secure connection actually occurred.
    print $ftp->lastErrorText() . "\n";
}

//  After logging on, you may examine the FTP server's cert:

$cert = $ftp->GetSslServerCert();
if (is_null($cert)) {
    print 'No server certificate!' . "\n";
}
else {
    //  Display the distinguished name of the SSL cert.
    print $cert->subjectDN() . "\n";
}

print 'Secure FTP Channel Established!' . "\n";

//  Do whatever you're doing to do ...
//  upload files, download files, etc...

$ftp->Disconnect();
?>