DataFlex

Initiate an SSH Key Re-Exchange

Demonstrates the Chilkat Ssh.ReKey method, which initiates an SSH key re-exchange and waits for it to complete. It takes no arguments. Either the client or the server may trigger rekeying at any time.

Background: Rekeying periodically replaces the session keys to limit how much data is protected by any single key. RFC 4253 recommends it after roughly one gigabyte of transfer or one hour, whichever comes first. In practice servers initiate this automatically and Chilkat handles it transparently, so calling ReKey explicitly is rarely necessary.

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DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoSsh
    Integer iSshPort
    String sPassword
    String sTemp1

    Move False To iSuccess

    //  Demonstrates the Ssh.ReKey method, which initiates an SSH key re-exchange and waits for it to
    //  complete.  It takes no arguments.  In normal use the server initiates rekeying as needed and
    //  Chilkat handles it transparently.

    Get Create (RefClass(cComChilkatSsh)) To hoSsh
    If (Not(IsComObjectCreated(hoSsh))) Begin
        Send CreateComObject of hoSsh
    End

    //  Connect to the SSH server.  Port 22 is the usual SSH port.
    Move 22 To iSshPort
    Get ComConnect Of hoSsh "ssh.example.com" iSshPort To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Normally you would not hard-code the password in source.  You should instead obtain it
    //  from an interactive prompt, environment variable, or a secrets vault.
    Move "mySshPassword" To sPassword

    Get ComAuthenticatePw Of hoSsh "mySshLogin" sPassword To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Explicitly initiate a key re-exchange on the live connection.
    Get ComReKey Of hoSsh To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Key re-exchange complete."

    Send ComDisconnect To hoSsh


End_Procedure