VS2015 Renci SSH.NET Unable to kill a process on AIX server with PowerBroker access

[BRoetzer]

Hi guys,

Tried this question on StackOverflow with no luck, giving it a shot here:

I'm trying to develop a Windows Form in VB.NET which can connect to an AIX server and retrieve the PID#'s for certain processes. The PID#'s are then stored in a DataGrid. The Windows Form also needs to be able to kill those PIDs if the user clicks a button on the form. The hitch is the PIDs are running as a different user account than the account I am using to SSH into the server with. The account I am using does however have PowerBroker access to the user account which owns the PIDs. I'm using Renci SSH.NET

Code to get the PID (this works fine and loads the PIDS into my DataGrid):

Private Sub getKILLPID()
    Dim newDataRow = killGrid.Rows(0)
    Dim pid As String
    Dim child As String
    Dim connInfo As New Renci.SshNet.PasswordConnectionInfo(ApplicationVariablesModule.serverName, ApplicationVariablesModule.psUsername, ApplicationVariablesModule.psPassword)
    Dim sshClient As New Renci.SshNet.SshClient(connInfo)
    Dim cmd As Renci.SshNet.SshCommand
    Using sshClient
        sshClient.Connect()
        cmd = sshClient.RunCommand("ps -ef | grep process_name  | grep -v grep | awk '{print $2}'")
        pid = cmd.Result.ToString
        cmd = sshClient.RunCommand("ps -ef | grep process_name  | grep -v grep | awk '{print $3}'")
        child = cmd.Result.ToString
        If pid.Length < 1 Then
            newDataRow.Cells(1).Value = "DOWN"
            newDataRow.Cells(2).Value = "n/a"
        Else
            newDataRow.Cells(1).Value = pid
            newDataRow.Cells(2).Value = child
        End If

Code which is failing to kill the PIDs:

Dim connInfo As New Renci.SshNet.PasswordConnectionInfo(ApplicationVariablesModule.serverName, ApplicationVariablesModule.psUsername, ApplicationVariablesModule.psPassword)
    Dim sshClient As New Renci.SshNet.SshClient(connInfo)
    Dim cmd As Renci.SshNet.SshCommand

        Using sshClient
            sshClient.Connect()
            cmd = sshClient.RunCommand("pbrun -u username /usr/bin/kill -9 " & pid)
            sshClient.Disconnect()
        End Using
End Sub

After I click on the button on the windows form nothing happens. If I login to the AIX server using PuTTy I can still see the process running. If I issue the exact same command thru PuTTy it works fine. I've checked the .sh_history file on the AIX server and there is no evidence the command was even executed on the server.

One other thing I've tried is to just write a .ksh script on the AIX server and let it kill the processes:

pids=`ps -ef | grep process_name | grep -v grep | awk '{print $2}'`
if [[ $pids != "" ]] then
  pbrun -u user /usr/bin/kill -9 $pids
  if [[ $? -ne 0 ]] then
    echo "Error killing process: $pids \n">>/home/user/logs/kill.log
    echo "Return code was: $?">>/home/user/logs/kill.log
    exit -1
 else
    echo "All process were successfully killed!\n">>/home/user/logs/kill.log
 fi
fi

Again, if I execute this .ksh script directly on the AIX server logging in via PuTTy w/ SSH it runs fine. But when I attempt to execute the script with SSH.NET thru my VB form

cmd = sshClient.RunCommand("cd /home/user/scripts; ./kill_process.ksh;")

it throws the error:

servername:/home/user/logs $ cat kill.log
Fri Aug 17 15:06:51 CDT 2018
Error killing process: 9699556

Return code was: 0

So my hunch is the problem lies somewhere in the permissions allowed between the Renci.dll used in my VBP Project and the AIX server.
I've read similar posts online about people having trouble with ssh.net and issuing SUDO commands, and the answer is always because sudo is interactive and requires username and password you need a TTY emulator. However in my scenario I'm using powerbroker to change user accounts and hence no password is required to be given interactively. Anyone come across this scenario before or know any work-arounds?