PureBasic

Verify FTP SSL Server Certificate

See more FTP Examples

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. PureBasic

IncludeFile "CkFtp2.pb"
IncludeFile "CkCert.pb"

Procedure ChilkatExample()

    success.i = 0

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

    ftp.i = CkFtp2::ckCreate()
    If ftp.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkFtp2::setCkHostname(ftp, "ftp.myftpserver.com")
    CkFtp2::setCkUsername(ftp, "myUsername")
    CkFtp2::setCkPassword(ftp, "myPassword")

    ; Establish an AUTH SSL secure channel after connection
    ; on the standard FTP port 21.
    CkFtp2::setCkAuthSsl(ftp, 1)

    ; The Ssl property is for establishing an implicit SSL connection
    ; on port 990.  Do not set it.
    CkFtp2::setCkSsl(ftp, 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:
    CkFtp2::setCkRequireSslCertVerify(ftp, 1)

    ; You may also set a requirement.  In this example,
    ; the certificate's Common Name (CN) must match the
    ; required string exactly:
    CkFtp2::ckSetSslCertRequirement(ftp,"subjectcn","Chilkat Software, Inc.")

    ; Connect and login to the FTP server.
    success = CkFtp2::ckConnect(ftp)
    If success = 0
        Debug CkFtp2::ckLastErrorText(ftp)
        CkFtp2::ckDispose(ftp)
        ProcedureReturn
    EndIf

    ; After logging on, you may examine the FTP server's cert:
    cert.i = CkCert::ckCreate()
    If cert.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkFtp2::ckGetServerCert(ftp,cert)
    If success = 0
        Debug "No server certificate!"
    Else
        ; Display the distinguished name of the SSL cert.
        Debug CkCert::ckSubjectDN(cert)
    EndIf

    Debug "Secure FTP Channel Established!"

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

    success = CkFtp2::ckDisconnect(ftp)


    CkFtp2::ckDispose(ftp)
    CkCert::ckDispose(cert)


    ProcedureReturn
EndProcedure