DataFlex

Use a TLS Client Certificate

Demonstrates the Chilkat MailMan.SetSslClientCert method, which sets the client-side certificate to use for SSL/TLS connections. This is typically not required — most SSL/TLS connections authenticate the server only. This example loads a client certificate from a PFX and uses it when connecting.

Background: In an ordinary TLS handshake only the server presents a certificate, and the client proves who it is later with a password. Mutual TLS adds a second leg: the client also presents a certificate, so it is authenticated cryptographically at the transport layer. Some corporate or high-security mail servers require this. Because the client must prove possession of the key, the certificate needs its private key — hence loading from a PFX.

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DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoMailman
    Variant vCert
    Handle hoCert
    String sTemp1

    Move False To iSuccess

    //  Demonstrates the MailMan.SetSslClientCert method, which sets the client-side certificate
    //  to use for SSL/TLS connections.  This is typically not required -- most SSL/TLS
    //  connections authenticate the server only.

    Get Create (RefClass(cComChilkatMailMan)) To hoMailman
    If (Not(IsComObjectCreated(hoMailman))) Begin
        Send CreateComObject of hoMailman
    End

    //  Configure the SMTP server connection.
    Set ComSmtpHost Of hoMailman To "smtp.example.com"
    Set ComSmtpPort Of hoMailman To 465
    Set ComSmtpSsl Of hoMailman To True
    Set ComSmtpUsername Of hoMailman To "user@example.com"
    Set ComSmtpPassword Of hoMailman To "myPassword"

    //  Load the client certificate (with its private key) from a PFX file.
    Get Create (RefClass(cComChilkatCert)) To hoCert
    If (Not(IsComObjectCreated(hoCert))) Begin
        Send CreateComObject of hoCert
    End
    Get ComLoadPfxFile Of hoCert "qa_data/certs/client.pfx" "pfx_password" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoCert To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Use this certificate to identify the client during the TLS handshake.
    Get pvComObject of hoCert to vCert
    Get ComSetSslClientCert Of hoMailman vCert To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoMailman To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComVerifySmtpLogin Of hoMailman To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoMailman To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Connected using a TLS client certificate."

    //  Note: The path "qa_data/certs/client.pfx" is a relative local filesystem path,
    //  relative to the current working directory of the running application.


End_Procedure