(VB.NET UWP/WinRT) 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 Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

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

Dim ftp As New Chilkat.Ftp2

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


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


Debug.WriteLine("Secure FTP Channel Established!")

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

success = Await ftp.DisconnectAsync()