Example function for how to obtain an access token for Microsoft Entra using the Web Account Manager (WAM) broker in Windows

Get-EntraAccessTokenWithWAM.ps1

Function Get-EntraAccessTokenWithWAM {
    [CmdletBinding()]
    param (
        [Parameter()]
        [string]
        $ClientId = "14d82eec-204b-4c2f-b7e8-296a70dab67e", # Microsoft Graph PowerShell
        [Parameter()]
        [string[]]
        $Scopes = "https://graph.microsoft.com/.default",
        [Parameter()]
        [string]
        $RedirectUri = "http://localhost"
    )

    # Makre sure we're running in PowerShell Core edition
    If ($PSEdition -ne "Core")
    {
        Write-Warning "This function is only supported in PowerShell Core"
        return
    }

    # Check for Az.Accounts module
    $AzAccountsModule = Get-Module -Name Az.Accounts -ListAvailable
    If ($null -eq $AzAccountsModule)
    {
        try 
        {
            Install-Module -Name Az.Accounts -Force -AllowClobber -Scope CurrentUser -Repository PSGallery -ErrorAction Stop    
        }
        catch 
        {
            throw "Failed to install Az.Accounts module: $_"
        }
    }
    
    # Import Az.Accounts module
    try 
    {
        Import-Module Az.Accounts -ErrorAction Stop    
    }
    catch 
    {
        throw $_
    }

    # Find the location of the Azure.Common assembly
    $LoadedAssemblies = [System.AppDomain]::CurrentDomain.GetAssemblies() | Select -ExpandProperty Location
    $AzureCommon = $LoadedAssemblies | 
        Where-Object { $_ -match "\\Modules\\Az.Accounts\\" -and $_ -match "Microsoft.Azure.Common" }
    $AzureCommonLocation = $AzureCommon.TrimEnd("Microsoft.Azure.Common.dll")

    # Locate the required assemblies
    $mima = Get-ChildItem -Path $AzureCommonLocation -Filter "Microsoft.IdentityModel.Abstractions.dll" -Recurse -File | Select -ExpandProperty FullName
    $mic = Get-ChildItem -Path $AzureCommonLocation -Filter "Microsoft.Identity.Client.dll" -Recurse -File | Select -ExpandProperty FullName
    $micb = Get-ChildItem -Path $AzureCommonLocation -Filter "Microsoft.Identity.Client.Broker.dll" -Recurse -File | Select -ExpandProperty FullName
    $micni = Get-ChildItem -Path $AzureCommonLocation -Filter "Microsoft.Identity.Client.NativeInterop.dll" -Recurse -File | Select -ExpandProperty FullName
    $micem = Get-ChildItem -Path $AzureCommonLocation -Filter "Microsoft.Identity.Client.Extensions.Msal.dll" -Recurse -File | Select -ExpandProperty FullName
    $sscpd = Get-ChildItem -Path $AzureCommonLocation -Filter "System.Security.Cryptography.ProtectedData.dll" -Recurse -File | Select -ExpandProperty FullName
    # This next one need to come from the .Net Core installation being used
    $RuntimeFrameworkMajorVersion = [System.Runtime.InteropServices.RuntimeInformation]::FrameworkDescription.Split()[-1].Split(".")[0]
    $dotNetDirectory = Get-ChildItem -Path "C:\Program Files\dotnet\packs\Microsoft.NETCore.App.Ref" -Filter "$RuntimeFrameworkMajorVersion.*" -Directory | 
        Sort-Object -Property Name -Descending | Select -First 1
    $sdts = Get-ChildItem -Path $dotNetDirectory -Filter "System.Diagnostics.TraceSource.dll" -Recurse -File | Select -ExpandProperty FullName
    
    # Load the assemblies
    try 
    {
        [void][System.Reflection.Assembly]::LoadFrom($mima)
        [void][System.Reflection.Assembly]::LoadFrom($mic)
        [void][System.Reflection.Assembly]::LoadFrom($micb)
        [void][System.Reflection.Assembly]::LoadFrom($micni)
        [void][System.Reflection.Assembly]::LoadFrom($sscpd)
        [void][System.Reflection.Assembly]::LoadFrom($sdts)
        [void][System.Reflection.Assembly]::LoadFrom($micem)
    }
    catch 
    {
        throw $_
    }

    # C# code to do the work since PS will not recognize the .WithBroker() extension method from the broker library
    $code = @"
using System;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.Identity.Client;
using Microsoft.Identity.Client.Broker;
using Microsoft.IdentityModel.Abstractions;
using Microsoft.Identity.Client.NativeInterop;
using Microsoft.Identity.Client.Extensions.Msal;

public class PublicClientAppHelper
{
    // This gets the window handle of the console window
    [DllImport("user32.dll", ExactSpelling = true)]
    public static extern IntPtr GetAncestor(IntPtr hwnd, GetAncestorFlags flags);

    [DllImport("kernel32.dll")]
    public static extern IntPtr GetConsoleWindow();

    public enum GetAncestorFlags
    {   
        GetParent = 1,
        GetRoot = 2,
        GetRootOwner = 3
    }

    public static IntPtr GetConsoleOrTerminalWindow()
    {
        IntPtr consoleHandle = GetConsoleWindow();
        IntPtr handle = GetAncestor(consoleHandle, GetAncestorFlags.GetRootOwner);
        
        return handle;
    }    
    
    // Setup a cache for the tokens
    private static BrokerOptions brokerOptions = new BrokerOptions(BrokerOptions.OperatingSystems.Windows);
    private static string cacheFileName = "msalcache.bin";
    private static string cacheFilePath = Path.Combine(MsalCacheHelper.UserRootDirectory, cacheFileName);
    private static string cacheDir = Path.GetDirectoryName(cacheFilePath);
    private static StorageCreationProperties storageProperties = new StorageCreationPropertiesBuilder(cacheFileName, cacheDir).Build();

    // Method for retrieving the access token
    public static async Task<string> GetAccessTokenWithWAM(string clientId, string redirectUri, string[] scopes)
    {
        IPublicClientApplication publicClientApp = PublicClientApplicationBuilder.Create(clientId)
            .WithBroker(brokerOptions)
            .WithParentActivityOrWindow(GetConsoleOrTerminalWindow)
            .WithRedirectUri(redirectUri)
            .Build();

        var cacheHelper = await MsalCacheHelper.CreateAsync(storageProperties).ConfigureAwait(false);
        cacheHelper.RegisterCache(publicClientApp.UserTokenCache);

        var accounts = await publicClientApp.GetAccountsAsync();
        var existingAccount = accounts.FirstOrDefault();

        AuthenticationResult result;
        CancellationTokenSource cancellationTokenSource = new CancellationTokenSource(TimeSpan.FromSeconds(90)); // Automatic cancellation after 90 seconds

        // try the cache first, fallback to interactive if necessary
        try
        {
            result = existingAccount != null
                ? await publicClientApp.AcquireTokenSilent(scopes, existingAccount).ExecuteAsync(cancellationTokenSource.Token)
                : await publicClientApp.AcquireTokenInteractive(scopes).ExecuteAsync(cancellationTokenSource.Token);
        }
        catch (MsalUiRequiredException)
        {
            result = await publicClientApp.AcquireTokenInteractive(scopes).ExecuteAsync(cancellationTokenSource.Token);
        }

        return result.AccessToken;
    }
}
"@
    # List of assemblies we need to reference
    $assemblies = @($mima, $mic, $micb, $micni, $micem, $sscpd, $sdts, "netstandard", "System.Linq")
    
    # Get the access token
    try 
    {
        # If the type already exists in the current session
        $token = [PublicClientAppHelper]::GetAccessTokenWithWAM($ClientId, $RedirectUri, $Scopes).GetAwaiter().GetResult()
        return $token
    }
    catch 
    {
        if ($_.FullyQualifiedErrorId -eq "TypeNotFound")
        {
            try 
            {
                # Add the type if it doesn't exist yet
                Add-Type -ReferencedAssemblies $assemblies -TypeDefinition $code -Language CSharp -ErrorAction Stop
                $token = [PublicClientAppHelper]::GetAccessTokenWithWAM($ClientId, $RedirectUri, $Scopes).GetAwaiter().GetResult()
                return $token
            }
            catch 
            {
                throw $_
            }
        }
        else 
        {
            throw $_    
        }
    }
}

## Example usage ##
# Obtain an access token for the Microsoft Graph API using the Microsoft Graph PowerShell SDK app
Get-EntraAccessTokenWithWAM
# Obtain an access token for the Azure SQL Database using the Azure CLI app
Get-EntraAccessTokenWithWAM -Scopes "https://database.windows.net/.default" -ClientId "04b07795-8ddb-461a-bbee-02f9e1bf7b46"
# Obtain an access token for the Azure SQL Database using the Azure PowerShell app
Get-EntraAccessTokenWithWAM -Scopes "https://database.windows.net/.default" -ClientId "1950a258-227b-4e31-a9cf-717495945fc2"

Getting below error when trying: Exception: C:\temp\Get-EntraAccessTokenWithWAM.ps1:73 Line | 73 | [void][System.Reflection.Assembly]::LoadFrom($sdts) | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | Exception calling "LoadFrom" with "1" argument(s): "Value cannot be null. (Parameter 'assemblyFile')"

Check lines 60-63 - make sure it can find "System.Diagnostics.TraceSource.dll" in your .Net core install directory