(C++) 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.

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#include <CkFtp2.h>
#include <CkCert.h>

void ChilkatSample(void)
    {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkFtp2 ftp;

    ftp.put_Hostname("ftp.myftpserver.com");
    ftp.put_Username("myUsername");
    ftp.put_Password("myPassword");

    // Establish an AUTH SSL secure channel after connection
    // on the standard FTP port 21.
    ftp.put_AuthSsl(true);

    // The Ssl property is for establishing an implicit SSL connection
    // on port 990.  Do not set it.
    ftp.put_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.put_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.
    bool success = ftp.Connect();
    if (success != true) {
        std::cout << ftp.lastErrorText() << "\r\n";
        return;
    }
    else {
        // LastErrorText contains information even when
        // successful. This allows you to visually verify
        // that the secure connection actually occurred.
        std::cout << ftp.lastErrorText() << "\r\n";
    }

    // After logging on, you may examine the FTP server's cert:
    CkCert *cert = 0;
    cert = ftp.GetSslServerCert();
    if (ftp.get_LastMethodSuccess() != true) {
        std::cout << "No server certificate!" << "\r\n";
    }
    else {
        // Display the distinguished name of the SSL cert.
        std::cout << cert->subjectDN() << "\r\n";
    }

    std::cout << "Secure FTP Channel Established!" << "\r\n";

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

    success = ftp.Disconnect();
    }