How to run a PowerShell script from C# as non-elevated user

Question

I'm trying to run a PowerShell script from a C# application and I need the script to run when my C# app is running as a non-admin user (e.g. Network Service or some other domain account).

Previously, I was using the following code:

using (RunspaceInvoke invoker = new RunspaceInvoke())
{
    // load the powershell module
    invoker.Invoke("Import-Module MyModule");

    // run the cmdlet defined in the module 
    invoker.Invoke("MyCmdlet");
}

I don't know whether this is the best approach for running cmdlets defined in a module (please teach me if there's a better way!). In any case, this works perfectly if I'm running as an administrative user. I tried running this as Network Service, however, and I got an unfriendly error in the constructor of RunspaceInvoke:

Requested registry access is not allowed.

Is there a way I can run my PowerShell cmdlets as a non-elevated user such as Network Service? I do not need or desire to access the registry. The cmdlet itself also does not require elevated privileges.

Answer 1

We use a version of the below. The "script" parameter is the PS script to run. We use this from a custom command line so that we can mix c# commands with some written in PS. "results" can be used to capture the evaluation of your script. The "out-default" line means that the output of the PS script is written to the console. A version of this can instead capture the output to a TextBox or similar if you have a WinForm of WPF app.

public void run(string script)
{
    IEnumerable<PSObject> results;
    var config = RunspaceConfiguration.Create();
    var host = new ScriptHost();
    using (var runspace = RunspaceFactory.CreateRunspace(host, config))
    {
        runspace.Open();
        runspace.SessionStateProxy.SetVariable("prog", this);

        using (var pipeline = runspace.CreatePipeline())
        {
            if (!string.IsNullOrEmpty(scriptPath))
                pipeline.Commands.AddScript(string.Format("$env:path = \"{0};\" + $env:path", scriptPath));

            pipeline.Commands.AddScript(script);

            var outDefault = new Command("out-default");
            outDefault.MergeMyResults(PipelineResultTypes.Error, PipelineResultTypes.Output);
            pipeline.Commands.Add(outDefault);

            results = pipeline.Invoke();
        }
    }
}