(DataFlex) 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

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoFtp
    Boolean iSuccess
    Variant vCert
    Handle hoCert
    String sTemp1
    Boolean bTemp1

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

    Get Create (RefClass(cComChilkatFtp2)) To hoFtp
    If (Not(IsComObjectCreated(hoFtp))) Begin
        Send CreateComObject of hoFtp
    End

    Set ComHostname Of hoFtp To "ftp.myftpserver.com"
    Set ComUsername Of hoFtp To "myUsername"
    Set ComPassword Of hoFtp To "myPassword"

    // Establish an AUTH SSL secure channel after connection
    // on the standard FTP port 21.
    Set ComAuthSsl Of hoFtp To True

    // The Ssl property is for establishing an implicit SSL connection
    // on port 990.  Do not set it.
    Set ComSsl Of hoFtp To 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:
    Set ComRequireSslCertVerify Of hoFtp To True

    // You may also set a requirement.  In this example,
    // the certificate's Common Name (CN) must match the
    // required string exactly:
    Send ComSetSslCertRequirement To hoFtp "subjectcn" "Chilkat Software, Inc."

    // Connect and login to the FTP server.
    Get ComConnect Of hoFtp To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoFtp To sTemp1
        Showln sTemp1
        Procedure_Return
    End
    Else Begin
        // LastErrorText contains information even when
        // successful. This allows you to visually verify
        // that the secure connection actually occurred.
        Get ComLastErrorText Of hoFtp To sTemp1
        Showln sTemp1
    End

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

    Get ComGetSslServerCert Of hoFtp To vCert
    If (IsComObject(vCert)) Begin
        Get Create (RefClass(cComChilkatCert)) To hoCert
        Set pvComObject Of hoCert To vCert
    End
    Get ComLastMethodSuccess Of hoFtp To bTemp1
    If (bTemp1 <> True) Begin
        Showln "No server certificate!"
    End
    Else Begin
        // Display the distinguished name of the SSL cert.
        Get ComSubjectDN Of hoCert To sTemp1
        Showln sTemp1
    End

    Showln "Secure FTP Channel Established!"

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

    Get ComDisconnect Of hoFtp To iSuccess


End_Procedure