(Visual Basic 6.0) 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

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

Dim ftp As New ChilkatFtp2

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 = 1

' The Ssl property is for establishing an implicit SSL connection
' on port 990.  Do not set it.
ftp.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:
ftp.RequireSslCertVerify = 1

' 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.
Dim success As Long
success = ftp.Connect()
If (success <> 1) Then
    Debug.Print ftp.LastErrorText
    Exit Sub
Else
    ' LastErrorText contains information even when
    ' successful. This allows you to visually verify
    ' that the secure connection actually occurred.
    Debug.Print ftp.LastErrorText
End If

' After logging on, you may examine the FTP server's cert:
Dim cert As ChilkatCert
Set cert = ftp.GetSslServerCert()
If (ftp.LastMethodSuccess <> 1) Then
    Debug.Print "No server certificate!"
Else
    ' Display the distinguished name of the SSL cert.
    Debug.Print cert.SubjectDN
End If

Debug.Print "Secure FTP Channel Established!"

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

success = ftp.Disconnect()