(Visual FoxPro) 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.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loFtp
LOCAL lnSuccess
LOCAL loCert

* This example requires the Chilkat API to have been previously unlocked.
* See Global Unlock Sample for sample code.

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Ftp2')
loFtp = CreateObject('Chilkat.Ftp2')

loFtp.Hostname = "ftp.myftpserver.com"
loFtp.Username = "myUsername"
loFtp.Password = "myPassword"

* Establish an AUTH SSL secure channel after connection
* on the standard FTP port 21.
loFtp.AuthSsl = 1

* The Ssl property is for establishing an implicit SSL connection
* on port 990.  Do not set it.
loFtp.Ssl = 0

* 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:
loFtp.RequireSslCertVerify = 1

* You may also set a requirement.  In this example,
* the certificate's Common Name (CN) must match the
* required string exactly:
loFtp.SetSslCertRequirement("subjectcn","Chilkat Software, Inc.")

* Connect and login to the FTP server.
lnSuccess = loFtp.Connect()
IF (lnSuccess <> 1) THEN
    ? loFtp.LastErrorText
    RELEASE loFtp
    CANCEL
ELSE
    * LastErrorText contains information even when
    * successful. This allows you to visually verify
    * that the secure connection actually occurred.
    ? loFtp.LastErrorText
ENDIF

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

loCert = loFtp.GetSslServerCert()
IF (loFtp.LastMethodSuccess <> 1) THEN
    ? "No server certificate!"
ELSE
    * Display the distinguished name of the SSL cert.
    ? loCert.SubjectDN
ENDIF

? "Secure FTP Channel Established!"

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

lnSuccess = loFtp.Disconnect()

RELEASE loFtp