How do I login to a XEN session from a C# program using a secure string password?

I contacted Citrix.

The Xen API does not provide a mechanism for logging into a session using a secure string password.

So, I ended up using a C# program that executes two PowerShell scripts that do support a secure string password.

See the code below.

Notes:

I have the 7.1.1 XenServerPSModule installed in %USERPROFILE%\Documents\WindowsPowerShell\Modules\XenServerPSModule. This module provides the Connect-XenServer cmdlet

I created the xml credentials file using PowerShell get-credentials followed by using export-clixml

I loaded the requisite System.Management.Automation reference by installing Microsoft.PowerShell.5.ReferenceAssemblies from NuGet

form1.cs (form has just a button)

using System;
using System.Windows.Forms;
using XenSnapshotsXenAccess;

namespace Create_XenSnapshotsUi
{
    public partial class Form1 : Form
    {
        XenSessionAccess xenSession = null;

        public Form1()
        {
            InitializeComponent();
        }

        private void Button1_Click(object sender, EventArgs e)
        {

            xenSession = new XenSessionAccess("https://xxx.xx.x.x", @"C:\foo\xml_credentials.xml");

            xenSession.Logout();

        }
    }
}

XenSessionAccess class

using System;
using System.Collections.ObjectModel;
using System.Management.Automation;
using System.Management.Automation.Runspaces;
using XenAPI;

namespace XenSnapshotsXenAccess
{
    public class XenSessionAccess
    {
        private Session xenSession = null;

        public Session XenSession { get => xenSession; set => xenSession = value; }

        public void Logout()
        {
            if (XenSession != null)
            {
                XenSession.logout(XenSession);
            }
        }

        public XenSessionAccess(string poolMasterServerUrl, string xml_creds_path)
        {
            Collection<PSObject> results = null;
            PSCredential psCredential = null;

            //https://learn.microsoft.com/en-us/powershell/developer/hosting/creating-an-initialsessionstate

            //Createdefault2* loads only the commands required to host Windows PowerShell (the commands from the Microsoft.PowerShell.Core module.
            InitialSessionState initialSessionState = InitialSessionState.CreateDefault2();

            using (Runspace runSpace = RunspaceFactory.CreateRunspace(initialSessionState))
            {
                runSpace.Open();

                using (PowerShell powerShell = PowerShell.Create())
                {
                    powerShell.Runspace = runSpace;
                    powerShell.AddCommand("Import-CliXml");

                    powerShell.AddArgument(xml_creds_path);
                    results = powerShell.Invoke();

                    if (results.Count == 1)
                    {
                        PSObject psOutput = results[0];
                        //cast the result to a PSCredential object
                        psCredential = (PSCredential)psOutput.BaseObject;
                    }
                    else
                    {
                        throw new System.Exception("Could not obtain pool master server credentials");
                    }
                }

                runSpace.Close();
            }

            initialSessionState = InitialSessionState.CreateDefault2();
            initialSessionState.ImportPSModule(new string[] { "XenServerPSModule" });
            initialSessionState.ExecutionPolicy = Microsoft.PowerShell.ExecutionPolicy.Unrestricted;

            SessionStateVariableEntry psCredential_var = new SessionStateVariableEntry("psCredential", psCredential, "Credentials to log into pool master server");
            initialSessionState.Variables.Add(psCredential_var);

            SessionStateVariableEntry poolUrl_var = new SessionStateVariableEntry("poolUrl", poolMasterServerUrl, "Url of pool master server");
            initialSessionState.Variables.Add(poolUrl_var);

            using (Runspace runSpace = RunspaceFactory.CreateRunspace(initialSessionState))
            {
                runSpace.Open();

                using (PowerShell powerShell = PowerShell.Create())
                {
                    powerShell.Runspace = runSpace;
                    powerShell.AddScript(@"$psCredential | Connect-XenServer -url $poolUrl -SetDefaultSession -PassThru");
                    results = powerShell.Invoke();
                }

                if (results.Count == 1)
                {
                    PSObject psOutput = results[0];
                    //cast the result to a XenAPI.Session object
                    XenSession = (Session)psOutput.BaseObject;
                }
                else
                {
                    throw new System.Exception(String.Format("Could not create session for {0}", poolMasterServerUrl));
                }

                runSpace.Close();
            }
        }
    }
}