DataFlex

Authenticate an SSH Tunnel with a Private Key

Demonstrates the Chilkat MailMan.SshAuthenticatePk method, which authenticates with the SSH server using public-key authentication after an SSH tunnel has been opened. The first argument is the SSH account name and the second is the SSH private key (an SshKey object). This example opens a tunnel, loads an OpenSSH private key, authenticates with it, and runs a POP3 operation through the tunnel.

Background: SSH public-key authentication replaces a password with a key pair: the public key is installed on the SSH server, and the client proves it holds the matching private key without ever transmitting a secret. This is the preferred method for automated systems — there is no password to embed or rotate, and the key can be revoked server-side. Chilkat reads the key with an SshKey object, which understands common formats such as OpenSSH and PuTTY.

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Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoMailman
    Variant vSshKey
    Handle hoSshKey
    String sKeyText
    Integer iCount
    String sTemp1
    Boolean bTemp1

    Move False To iSuccess

    //  Demonstrates the MailMan.SshAuthenticatePk method, which authenticates with the SSH server
    //  using public-key authentication after an SSH tunnel has been opened.  The 1st argument is
    //  the SSH account name and the 2nd is the SSH private key.

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

    //  Configure the POP3 server connection.  These connections will travel through the tunnel.
    Set ComMailHost Of hoMailman To "pop.example.com"
    Set ComMailPort Of hoMailman To 995
    Set ComPopSsl Of hoMailman To True
    Set ComPopUsername Of hoMailman To "user@example.com"
    Set ComPopPassword Of hoMailman To "myPassword"

    //  Open the SSH tunnel first.
    Get ComSshOpenTunnel Of hoMailman "ssh.example.com" 22 To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoMailman To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Load the SSH private key from an OpenSSH-format key file.
    Get Create (RefClass(cComChilkatSshKey)) To hoSshKey
    If (Not(IsComObjectCreated(hoSshKey))) Begin
        Send CreateComObject of hoSshKey
    End
    Get ComLoadText Of hoSshKey "qa_data/ssh/id_rsa" To sKeyText
    Get ComLastMethodSuccess Of hoSshKey To bTemp1
    If (bTemp1 = False) Begin
        Get ComLastErrorText Of hoSshKey To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComFromOpenSshPrivateKey Of hoSshKey sKeyText To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSshKey To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Authenticate with the SSH server using the private key.
    Get pvComObject of hoSshKey to vSshKey
    Get ComSshAuthenticatePk Of hoMailman "sshUser" vSshKey To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoMailman To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  POP3 operations now travel through the SSH tunnel.
    Get ComGetMailboxCount Of hoMailman To iCount
    If (iCount < 0) Begin
        Showln "Failed to get the mailbox count."
    End
    Else Begin
        Showln "Mailbox count: " iCount
    End

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

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


End_Procedure