DataFlex

SFTP Authenticate with a Private Key

Demonstrates the Chilkat SFtp.AuthenticatePk method, which authenticates the connected session using public-key authentication. The first argument is the username and the second is an SshKey private key. The matching public key must already be authorized for the account on the server.

Note: The private-key path is relative to the application's current working directory. Supply the path to your own key file.

Background: Public-key authentication is the standard for unattended SFTP transfers: the private key stays on the client, the server trusts the corresponding public key, and no reusable password crosses the wire. The SshKey object imports keys in several formats — this example loads an OpenSSH private key. For an encrypted key, set its Password property before importing.

Chilkat DataFlex Downloads

Download Chilkat for DataFlex

DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoSftp
    Integer iPort
    Variant vPrivKey
    Handle hoPrivKey
    String sKeyText
    String sTemp1
    Boolean bTemp1

    Move False To iSuccess

    //  Demonstrates the SFtp.AuthenticatePk method, which authenticates the connected session using
    //  public-key authentication.  The 1st argument is the username and the 2nd is an SshKey private
    //  key.  The matching public key must already be authorized for the account on the server.

    Get Create (RefClass(cComChilkatSFtp)) To hoSftp
    If (Not(IsComObjectCreated(hoSftp))) Begin
        Send CreateComObject of hoSftp
    End

    //  Step 1: Connect the SSH transport.  Port 22 is the usual port.
    Move 22 To iPort
    Get ComConnect Of hoSftp "sftp.example.com" iPort To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSftp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Load the SSH private key.  LoadText reads the file's text, which is then imported.
    Get Create (RefClass(cComChilkatSshKey)) To hoPrivKey
    If (Not(IsComObjectCreated(hoPrivKey))) Begin
        Send CreateComObject of hoPrivKey
    End
    Get ComLoadText Of hoPrivKey "qa_data/id_rsa" To sKeyText
    Get ComLastMethodSuccess Of hoPrivKey To bTemp1
    If (bTemp1 = False) Begin
        Get ComLastErrorText Of hoPrivKey To sTemp1
        Showln sTemp1
        Procedure_Return
    End

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

    Get pvComObject of hoPrivKey to vPrivKey
    Get ComAuthenticatePk Of hoSftp "mySshLogin" vPrivKey To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSftp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Step 3: Open the SFTP subsystem.  This must be done after authentication and before any
    //  file or directory operations.
    Get ComInitializeSftp Of hoSftp To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSftp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Authenticated with a private key."

    Send ComDisconnect To hoSftp


End_Procedure