Fixing key defaulting regression (#9307)

Author: mathewc

src/WebJobs.Script.WebHost/Security/Authentication/Jwt/ScriptJwtBearerExtensions.cs

@@ -3,7 +3,6 @@
 
 using System.Linq;
 using System.Security.Claims;
-using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Authentication;
@@ -73,15 +72,11 @@ public static AuthenticationBuilder AddScriptJwtBearer(this AuthenticationBuilde
 
         private static TokenValidationParameters CreateTokenValidationParameters()
         {
+            var signingKeys = SecretsUtility.GetTokenIssuerSigningKeys();
             var result = new TokenValidationParameters();
-            if (SecretsUtility.TryGetEncryptionKey(out string key))
+            if (signingKeys.Length > 0)
             {
-                // TODO: Once ScriptSettingsManager is gone, Audience and Issuer should be pulled from configuration.
-                result.IssuerSigningKeys = new SecurityKey[]
-                {
-                    new SymmetricSecurityKey(key.ToKeyBytes()),
-                    new SymmetricSecurityKey(Encoding.UTF8.GetBytes(key))
-                };
+                result.IssuerSigningKeys = signingKeys;
                 result.ValidateAudience = true;
                 result.ValidateIssuer = true;
                 result.ValidAudiences = new string[]

src/WebJobs.Script.WebHost/Security/SecretsUtility.cs

@@ -2,8 +2,11 @@
 // Licensed under the MIT License. See License.txt in the project root for license information.
 
 using System;
+using System.Collections.Generic;
 using System.Linq;
+using System.Text;
 using Microsoft.Azure.Web.DataProtection;
+using Microsoft.IdentityModel.Tokens;
 
 namespace Microsoft.Azure.WebJobs.Script.WebHost
 {
@@ -68,6 +71,30 @@ public static byte[] GetEncryptionKey(IEnvironment environment = null)
             return key.ToKeyBytes();
         }
 
+        public static SymmetricSecurityKey[] GetTokenIssuerSigningKeys()
+        {
+            List<SymmetricSecurityKey> signingKeys = new List<SymmetricSecurityKey>();
+
+            // first we want to use the DataProtection APIs to get the default key,
+            // which will return any user specified AzureWebEncryptionKey with precedence
+            // over the platform default key
+            string defaultKey = Util.GetDefaultKeyValue();
+            if (defaultKey != null)
+            {
+                signingKeys.Add(new SymmetricSecurityKey(defaultKey.ToKeyBytes()));
+                signingKeys.Add(new SymmetricSecurityKey(Encoding.UTF8.GetBytes(defaultKey)));
+            }
+
+            // next we want to ensure a key is also added for the platform default key
+            // if it wasn't already added above
+            if (SecretsUtility.TryGetEncryptionKey(out string key) && !string.Equals(key, defaultKey))
+            {
+                signingKeys.Add(new SymmetricSecurityKey(key.ToKeyBytes()));
+            }
+
+            return signingKeys.ToArray();
+        }
+
         public static byte[] ToKeyBytes(this string hexOrBase64)
         {
             // only support 32 bytes (256 bits) key length

test/WebJobs.Script.Tests.Integration/WebHostEndToEnd/SWAEndToEndTests.cs

@@ -1,17 +1,19 @@
-using Microsoft.Azure.WebJobs.Script.WebHost;
-using Microsoft.Azure.WebJobs.Script.WebHost.Management;
-using Microsoft.Azure.WebJobs.Script.WebHost.Security;
-using Microsoft.Azure.WebJobs.Script.Workers.Rpc;
-using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.DependencyInjection.Extensions;
-using Newtonsoft.Json;
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the MIT License. See License.txt in the project root for license information.
+
 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Net;
 using System.Net.Http;
 using System.Net.Http.Headers;
 using System.Threading.Tasks;
+using Microsoft.Azure.WebJobs.Script.WebHost;
+using Microsoft.Azure.WebJobs.Script.WebHost.Management;
+using Microsoft.Azure.WebJobs.Script.Workers.Rpc;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using Newtonsoft.Json;
 using Xunit;
 
 namespace Microsoft.Azure.WebJobs.Script.Tests.Integration.WebHostEndToEnd
@@ -68,7 +70,7 @@ public async Task InvokeFunction_FunctionLevel_ValidToken_Succeeds(string header
         {
             // if an admin token is passed, the function invocation succeeds
             HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get, "api/HttpTrigger-FunctionAuth?code=test");
-            string token = _fixture.Host.GenerateAdminJwtToken();
+            string token = GetSWAAdminJwtToken();
 
             if (string.Compare(nameof(HttpRequestHeader.Authorization), headerName) == 0)
             {
@@ -83,6 +85,16 @@ public async Task InvokeFunction_FunctionLevel_ValidToken_Succeeds(string header
             response.EnsureSuccessStatusCode();
         }
 
+        private string GetSWAAdminJwtToken()
+        {
+            // Ensure we use AzureWebEncryptionKey to generate tokens, as that's what SWA does
+            string keyValue = _fixture.SWAEncryptionKey;
+            byte[] keyBytes = keyValue.ToKeyBytes();
+            string token = _fixture.Host.GenerateAdminJwtToken(key: keyBytes);
+
+            return token;
+        }
+
         [Fact]
         public async Task SyncTriggers_Succeeds()
         {
@@ -109,19 +121,28 @@ public class TestFixture : EndToEndTestFixture
 
             public TestFixture() : base(@"TestScripts\CSharp", "csharp", RpcWorkerConstants.DotNetLanguageWorkerName, addTestSettings: false)
             {
+                // SWA generates their own key and sets via AzureWebEncryptionKey
+                // This should take precedence over the default key
                 var testKeyBytes = TestHelpers.GenerateKeyBytes();
                 var testKey = TestHelpers.GenerateKeyHexString(testKeyBytes);
+                SWAEncryptionKey = testKey;
+
+                // Default key provisioned by Antares and available via WEBSITE_AUTH_ENCRYPTION_KEY
+                var defaultTestKeyBytes = TestHelpers.GenerateKeyBytes();
+                var defaultTestKey = TestHelpers.GenerateKeyHexString(defaultTestKeyBytes);
 
                 var settings = new Dictionary<string, string>()
                 {
                     { "AzureWebEncryptionKey", testKey },
-                    { EnvironmentSettingNames.WebSiteAuthEncryptionKey, testKey },
+                    { EnvironmentSettingNames.WebSiteAuthEncryptionKey, defaultTestKey },
                     { "AzureWebJobsStorage", null },
                     { EnvironmentSettingNames.AzureWebsiteName, "testsite" }
                 };
                 _scopedEnvironment = new TestScopedEnvironmentVariable(settings);
             }
 
+            public string SWAEncryptionKey { get; }
+
             public override void ConfigureScriptHost(IWebJobsBuilder webJobsBuilder)
             {
                 base.ConfigureScriptHost(webJobsBuilder);