DataFlex

Get the SMTP or POP3 Server's TLS Certificate

Demonstrates the Chilkat MailMan.GetServerCert method, which gets the digital certificate presented by the SMTP or POP3 server for the current SSL/TLS connection and stores it in a Cert object. Pass true for the SMTP server's certificate or false for the POP3 server's. This example connects to the SMTP server and prints the certificate's subject and issuer.

Background: During a TLS handshake the server presents a certificate proving its identity, and the client validates it against trusted authorities. Retrieving that certificate lets you inspect it yourself — checking the subject, issuer, or expiration for auditing, logging, or certificate-pinning style checks. It must be called while a TLS connection is established, since the certificate belongs to that specific session.

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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.GetServerCert method, which gets the digital certificate
    //  presented by the SMTP or POP3 server for the current SSL/TLS connection.  Pass True for
    //  the SMTP server's certificate, or False for the POP3 server's certificate.

    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"

    //  Establish the TLS connection.
    Get ComSmtpConnect Of hoMailman To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoMailman To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Get the certificate the SMTP server presented (useSmtp = True).
    Get Create (RefClass(cComChilkatCert)) To hoCert
    If (Not(IsComObjectCreated(hoCert))) Begin
        Send CreateComObject of hoCert
    End
    Get pvComObject of hoCert to vCert
    Get ComGetServerCert Of hoMailman True vCert To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoMailman To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComSubjectCN Of hoCert To sTemp1
    Showln "Server certificate subject (CN): " sTemp1
    Get ComIssuerCN Of hoCert To sTemp1
    Showln "Issued by: " sTemp1

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



End_Procedure