Lozensky/enable managed identity

.gitignore

@@ -350,3 +350,6 @@ MigrationBackup/
 # Ionide (cross platform F# VS Code tools) working folder
 .ionide/
 /tools/app-provisioning-tool/testwebapp
+
+# Playwright e2e testing trace files
+tests/E2E Tests/PlaywrightTraces

src/Microsoft.Identity.Web.TokenAcquisition/DefaultAuthorizationHeaderProvider.cs

@@ -37,7 +37,10 @@ public async Task<string> CreateAuthorizationHeaderForUserAsync(
         }
 
         /// <inheritdoc/>
-        public async Task<string> CreateAuthorizationHeaderForAppAsync(string scopes, AuthorizationHeaderProviderOptions? downstreamApiOptions = null, CancellationToken cancellationToken = default)
+        public async Task<string> CreateAuthorizationHeaderForAppAsync(
+            string scopes,
+            AuthorizationHeaderProviderOptions? downstreamApiOptions = null,
+            CancellationToken cancellationToken = default)
         {
             var result = await _tokenAcquisition.GetAuthenticationResultForAppAsync(
                 scopes,
@@ -47,7 +50,9 @@ public async Task<string> CreateAuthorizationHeaderForAppAsync(string scopes, Au
             return result.CreateAuthorizationHeader();
         }
 
-        private static TokenAcquisitionOptions CreateTokenAcquisitionOptionsFromApiOptions(AuthorizationHeaderProviderOptions? downstreamApiOptions, CancellationToken cancellationToken)
+        private static TokenAcquisitionOptions CreateTokenAcquisitionOptionsFromApiOptions(
+            AuthorizationHeaderProviderOptions? downstreamApiOptions,
+            CancellationToken cancellationToken)
         {
             return new TokenAcquisitionOptions()
             {
@@ -58,6 +63,7 @@ private static TokenAcquisitionOptions CreateTokenAcquisitionOptionsFromApiOptio
                 ExtraQueryParameters = downstreamApiOptions?.AcquireTokenOptions.ExtraQueryParameters,
                 ForceRefresh = downstreamApiOptions?.AcquireTokenOptions.ForceRefresh ?? false,
                 LongRunningWebApiSessionKey = downstreamApiOptions?.AcquireTokenOptions.LongRunningWebApiSessionKey,
+                ManagedIdentity = downstreamApiOptions?.AcquireTokenOptions.ManagedIdentity,
                 Tenant = downstreamApiOptions?.AcquireTokenOptions.Tenant,
                 UserFlow = downstreamApiOptions?.AcquireTokenOptions.UserFlow,
                 PopPublicKey = downstreamApiOptions?.AcquireTokenOptions.PopPublicKey,

src/Microsoft.Identity.Web.TokenAcquisition/TokenAcquisition.ManagedIdentity.cs

@@ -0,0 +1,114 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+using System.Collections.Concurrent;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Identity.Abstractions;
+using Microsoft.Identity.Client;
+using Microsoft.Identity.Client.AppConfig;
+using Microsoft.IdentityModel.Tokens;
+
+namespace Microsoft.Identity.Web
+{
+    /// <summary>
+    /// Portion of the TokenAcquisition class that handles logic unique to managed identity.
+    /// </summary>
+    internal partial class TokenAcquisition
+    {
+        private readonly ConcurrentDictionary<string, IManagedIdentityApplication> _managedIdentityApplicationsByClientId = new();
+        private readonly SemaphoreSlim _managedIdSemaphore = new(1, 1);
+        private const string SystemAssignedManagedIdentityKey = "SYSTEM";
+
+        /// <summary>
+        /// Gets a cached ManagedIdentityApplication object or builds a new one if not found.
+        /// </summary>
+        /// <param name="mergedOptions">The configuration options for the app.</param>
+        /// <param name="managedIdentityOptions">The configuration specific to managed identity.</param>
+        /// <returns>The application object used to request a token with managed identity.</returns>
+        internal async Task<IManagedIdentityApplication> GetOrBuildManagedIdentityApplication(
+            MergedOptions mergedOptions,
+            ManagedIdentityOptions managedIdentityOptions)
+        {
+            string key = GetCacheKeyForManagedId(managedIdentityOptions);
+
+            // Check if the application is already built, if so return it without grabbing the lock
+            if (_managedIdentityApplicationsByClientId.TryGetValue(key, out IManagedIdentityApplication? application))
+            {
+                return application;
+            }
+
+            // Lock the potential write of the dictionary to prevent multiple threads from creating the same application.
+            await _managedIdSemaphore.WaitAsync();
+            try
+            {
+                // Check if the application is already built (could happen between previous check and obtaining the key)
+                if (_managedIdentityApplicationsByClientId.TryGetValue(key, out application))
+                {
+                    return application;
+                }
+
+                // Set managedIdentityId to the correct value for either system or user assigned
+                ManagedIdentityId managedIdentityId;
+                if (key == SystemAssignedManagedIdentityKey)
+                {
+                    managedIdentityId = ManagedIdentityId.SystemAssigned;
+                }
+                else
+                {
+                    managedIdentityId = ManagedIdentityId.WithUserAssignedClientId(key);
+                }
+
+                // Build the application
+                application = BuildManagedIdentityApplication(
+                    managedIdentityId,
+                    mergedOptions.ConfidentialClientApplicationOptions.EnablePiiLogging
+                );
+
+                // Add the application to the cache
+                _managedIdentityApplicationsByClientId.TryAdd(key, application);
+            }
+            finally
+            {
+                // Now that the dictionary is updated, release the semaphore
+                _managedIdSemaphore.Release();
+            }
+            return application;
+        }
+
+        /// <summary>
+        /// Creates a managed identity client application.
+        /// </summary>
+        /// <param name="managedIdentityId">Indicates if system-assigned or user-assigned managed identity is used.</param>
+        /// <param name="enablePiiLogging">Indicates if logging that may contain personally identifiable information is enabled.</param>
+        /// <returns>A managed identity application.</returns>
+        private IManagedIdentityApplication BuildManagedIdentityApplication(ManagedIdentityId managedIdentityId, bool enablePiiLogging)
+        {
+            return ManagedIdentityApplicationBuilder
+                .Create(managedIdentityId)
+                .WithLogging(
+                    Log,
+                    ConvertMicrosoftExtensionsLogLevelToMsal(_logger),
+                    enablePiiLogging: enablePiiLogging)
+                .Build();
+        }
+
+        /// <summary>
+        /// Gets the key value for the Managed Identity cache, the default key for system-assigned identity is used if there is
+        /// no clientId for a user-assigned identity specified. The method is internal rather than private for testing purposes.
+        /// </summary>
+        /// <param name="managedIdOptions">Holds the clientId for managed identity if none is present.</param>
+        /// <returns>A key value for the Managed Identity cache.</returns>
+        internal static string GetCacheKeyForManagedId(ManagedIdentityOptions managedIdOptions)
+        {
+            if (managedIdOptions.UserAssignedClientId.IsNullOrEmpty())
+            {
+                return SystemAssignedManagedIdentityKey;
+            }
+            else
+            {
+                return managedIdOptions.UserAssignedClientId!;
+            }
+        }
+    }
+}

src/Microsoft.Identity.Web.TokenAcquisition/TokenAcquisition.cs

@@ -19,11 +19,11 @@
 using Microsoft.Identity.Client;
 using Microsoft.Identity.Client.Advanced;
 using Microsoft.Identity.Client.Extensibility;
+using Microsoft.Identity.Web.Experimental;
 using Microsoft.Identity.Web.TokenCacheProviders;
 using Microsoft.Identity.Web.TokenCacheProviders.InMemory;
 using Microsoft.IdentityModel.JsonWebTokens;
 using Microsoft.IdentityModel.Tokens;
-using Microsoft.Identity.Web.Experimental;
 
 namespace Microsoft.Identity.Web
 {
@@ -47,9 +47,9 @@ class OAuthConstants
         private readonly object _applicationSyncObj = new();
 
         /// <summary>
-        ///  Please call GetOrBuildConfidentialClientApplication instead of accessing this field directly.
+        ///  Please call GetOrBuildConfidentialClientApplication instead of accessing _applicationsByAuthorityClientId directly.
         /// </summary>
-        private readonly ConcurrentDictionary<string, IConfidentialClientApplication?> _applicationsByAuthorityClientId = new ConcurrentDictionary<string, IConfidentialClientApplication?>();
+        private readonly ConcurrentDictionary<string, IConfidentialClientApplication?> _applicationsByAuthorityClientId = new();
         private bool _retryClientCertificate;
         protected readonly IMsalHttpClientFactory _httpClientFactory;
         protected readonly ILogger _logger;
@@ -115,7 +115,7 @@ public async Task<AcquireTokenResult> AddAccountToCacheFromAuthorizationCodeAsyn
             _ = Throws.IfNull(authCodeRedemptionParameters.Scopes);
             MergedOptions mergedOptions = _tokenAcquisitionHost.GetOptions(authCodeRedemptionParameters.AuthenticationScheme, out string effectiveAuthenticationScheme);
 
-            IConfidentialClientApplication? application=null;
+            IConfidentialClientApplication? application = null;
             try
             {
                 application = GetOrBuildConfidentialClientApplication(mergedOptions);
@@ -321,9 +321,10 @@ private void LogAuthResult(AuthenticationResult? authenticationResult)
 
         /// <summary>
         /// Acquires an authentication result from the authority configured in the app, for the confidential client itself (not on behalf of a user)
-        /// using the client credentials flow. See https://aka.ms/msal-net-client-credentials.
+        /// using either a client credentials or managed identity flow. See https://aka.ms/msal-net-client-credentials for client credentials or
+        /// https://aka.ms/Entra/ManagedIdentityOverview for managed identity.
         /// </summary>
-        /// <param name="scope">The scope requested to access a protected API. For this flow (client credentials), the scope
+        /// <param name="scope">The scope requested to access a protected API. For these flows (client credentials or managed identity), the scope
         /// should be of the form "{ResourceIdUri/.default}" for instance <c>https://management.azure.net/.default</c> or, for Microsoft
         /// Graph, <c>https://graph.microsoft.com/.default</c> as the requested scopes are defined statically with the application registration
         /// in the portal, and cannot be overridden in the application, as you can request a token for only one resource at a time (use
@@ -358,10 +359,28 @@ public async Task<AuthenticationResult> GetAuthenticationResultForAppAsync(
                 throw new ArgumentException(IDWebErrorMessage.ClientCredentialTenantShouldBeTenanted, nameof(tenant));
             }
 
+            // If using managed identity 
+            if (tokenAcquisitionOptions != null && tokenAcquisitionOptions.ManagedIdentity != null)
+            {
+                try
+                {
+                    IManagedIdentityApplication managedIdApp = await GetOrBuildManagedIdentityApplication(
+                        mergedOptions,
+                        tokenAcquisitionOptions.ManagedIdentity
+                    );
+                    return await managedIdApp.AcquireTokenForManagedIdentity(scope).ExecuteAsync().ConfigureAwait(false);
+                }
+                catch (Exception ex)
+                {
+                    Logger.TokenAcquisitionError(_logger, ex.Message, ex);
+                    throw;
+                }
+            }
+
             // Use MSAL to get the right token to call the API
             var application = GetOrBuildConfidentialClientApplication(mergedOptions);
 
-            var builder = application
+            AcquireTokenForClientParameterBuilder builder = application
                    .AcquireTokenForClient(new[] { scope }.Except(_scopesRequestedByMsal))
                    .WithSendX5C(mergedOptions.SendX5C);
 
@@ -585,7 +604,6 @@ private bool IsInvalidClientCertificateOrSignedAssertionError(MsalServiceExcepti
                     _applicationsByAuthorityClientId.TryAdd(GetApplicationKey(mergedOptions), application);
                 }
             }
-
             return application;
         }
 
@@ -599,7 +617,7 @@ private IConfidentialClientApplication BuildConfidentialClientApplication(Merged
 
             try
             {
-                var builder = ConfidentialClientApplicationBuilder
+                ConfidentialClientApplicationBuilder builder = ConfidentialClientApplicationBuilder
                         .CreateWithApplicationOptions(mergedOptions.ConfidentialClientApplicationOptions)
                         .WithHttpClientFactory(_httpClientFactory)
                         .WithLogging(
@@ -848,8 +866,10 @@ private static void CheckAssertionsForInjectionAttempt(string assertion, string
                 if (!assertion.IsNullOrEmpty() && assertion.Contains('&')) throw new ArgumentException(IDWebErrorMessage.InvalidAssertion, nameof(assertion));
                 if (!subAssertion.IsNullOrEmpty() && subAssertion.Contains('&')) throw new ArgumentException(IDWebErrorMessage.InvalidSubAssertion, nameof(subAssertion));
 #else
-                if (!assertion.IsNullOrEmpty() && assertion.Contains('&', StringComparison.InvariantCultureIgnoreCase)) throw new ArgumentException(IDWebErrorMessage.InvalidAssertion, nameof(assertion));
-                if (!subAssertion.IsNullOrEmpty() && subAssertion.Contains('&', StringComparison.InvariantCultureIgnoreCase)) throw new ArgumentException(IDWebErrorMessage.InvalidSubAssertion, nameof(subAssertion));
+                if (!assertion.IsNullOrEmpty() && assertion.Contains('&', StringComparison.InvariantCultureIgnoreCase))
+                    throw new ArgumentException(IDWebErrorMessage.InvalidAssertion, nameof(assertion));
+                if (!subAssertion.IsNullOrEmpty() && subAssertion.Contains('&', StringComparison.InvariantCultureIgnoreCase))
+                    throw new ArgumentException(IDWebErrorMessage.InvalidSubAssertion, nameof(subAssertion));
 #endif
             }
         }

src/Microsoft.Identity.Web.TokenAcquisition/TokenAcquisitionOptions.cs

@@ -45,6 +45,7 @@ public class TokenAcquisitionOptions : AcquireTokenOptions
                 PopClaim = PopClaim,
                 CancellationToken = CancellationToken,
                 LongRunningWebApiSessionKey = LongRunningWebApiSessionKey,
+                ManagedIdentity = ManagedIdentity,
             };
         }
     }

tests/E2E Tests/TokenAcquirerTests/OnlyOnAzureDevopsFactAttribute.cs

@@ -0,0 +1,20 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+using System;
+using Xunit;
+
+namespace TokenAcquirerTests
+{
+    public sealed class OnlyOnAzureDevopsFactAttribute : FactAttribute
+    {
+        public OnlyOnAzureDevopsFactAttribute()
+        {
+            if (IgnoreOnAzureDevopsFactAttribute.IsRunningOnAzureDevOps())
+            {
+                return;
+            }
+            Skip = "Ignored when not on Azure DevOps";
+        }
+    }
+}

tests/E2E Tests/TokenAcquirerTests/TokenAcquirer.cs

@@ -3,9 +3,11 @@
 
 using System;
 using System.Linq;
+using System.Net.Http;
 using System.Security.Cryptography;
 using System.Security.Cryptography.X509Certificates;
 using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Options;
 using Microsoft.Graph;
@@ -299,5 +301,46 @@ private static async Task CreateGraphClientAndAssert(TokenAcquirerFactory tokenA
             Assert.NotNull(result.AccessToken);
         }
     }
+
+    public class AcquireTokenManagedIdentity 
+    {
+        [OnlyOnAzureDevopsFact]
+        //[Fact]
+        public async Task AcquireTokenWithManagedIdentity_UserAssigned()
+        {
+            // Arrange
+            const string scope = "https://vault.azure.net/.default";
+            const string baseUrl = "https://vault.azure.net";
+            const string clientId = "9c5896db-a74a-4b1a-a259-74c5080a3a6a";
+            TokenAcquirerFactory tokenAcquirerFactory = TokenAcquirerFactory.GetDefaultInstance();
+            _ = tokenAcquirerFactory.Services;
+            IServiceProvider serviceProvider = tokenAcquirerFactory.Build();
+
+            // Act: Get the authorization header provider and add the options to tell it to use Managed Identity
+            IAuthorizationHeaderProvider? api = serviceProvider.GetRequiredService<IAuthorizationHeaderProvider>();
+            Assert.NotNull(api);
+            string result = await api.CreateAuthorizationHeaderForAppAsync(scope, GetAuthHeaderOptions_ManagedId(baseUrl, clientId));
+
+            // Assert: Make sure we got a token
+            Assert.False(string.IsNullOrEmpty(result));
+        }
+
+        private static AuthorizationHeaderProviderOptions GetAuthHeaderOptions_ManagedId(string baseUrl, string? userAssignedClientId=null) 
+        {
+            ManagedIdentityOptions managedIdentityOptions = new()
+            {
+                UserAssignedClientId = userAssignedClientId
+            };
+            AcquireTokenOptions aquireTokenOptions = new()
+            {
+                ManagedIdentity = managedIdentityOptions
+            };
+            return new AuthorizationHeaderProviderOptions()
+            {
+                BaseUrl = baseUrl,
+                AcquireTokenOptions = aquireTokenOptions
+            };
+        }
+    }
 #endif //FROM_GITHUB_ACTION
 }

tests/Microsoft.Identity.Web.Test.Common/TestConstants.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Reflection;
 
 namespace Microsoft.Identity.Web.Test.Common
 {
@@ -186,8 +187,14 @@ public static class TestConstants
         public static readonly string s_todoListServicePath = Path.DirectorySeparatorChar.ToString() + "TodoListService";
 
 
-        // TokenAcqusitionOptions
+        // TokenAcqusitionOptions and ManagedIdentityOptions
         public static Guid s_correlationId = new Guid("6347d33d-941a-4c35-9912-a9cf54fb1b3e");
+        public const string UserAssignedManagedIdentityClientId = "3b57c42c-3201-4295-ae27-d6baec5b7027";
+        public const string UserAssignedManagedIdentityResourceId = "/subscriptions/c1686c51-b717-4fe0-9af3-24a20a41fb0c/" +
+            "resourcegroups/MSAL_MSI/providers/Microsoft.ManagedIdentity/userAssignedIdentities/" + "MSAL_MSI_USERID";
+        public const BindingFlags StaticPrivateFieldFlags = BindingFlags.GetField | BindingFlags.Static | BindingFlags.NonPublic;
+        public const BindingFlags InstancePrivateFieldFlags = BindingFlags.GetField | BindingFlags.Instance | BindingFlags.NonPublic;
+        public const BindingFlags StaticPrivateMethodFlags = BindingFlags.InvokeMethod | BindingFlags.Static | BindingFlags.NonPublic;
 
         // AadIssuerValidation
         public const string AadAuthority = "aadAuthority";