Added FromCustomAuthorizerAttribute and tests.

Libraries/Amazon.Lambda.Annotations.slnf

@@ -11,9 +11,12 @@
       "src\\Amazon.Lambda.Serialization.SystemTextJson\\Amazon.Lambda.Serialization.SystemTextJson.csproj",
       "test\\Amazon.Lambda.Annotations.SourceGenerators.Tests\\Amazon.Lambda.Annotations.SourceGenerators.Tests.csproj",
       "test\\TestExecutableServerlessApp\\TestExecutableServerlessApp.csproj",
+      "test\\IntegrationTests.Helpers\\IntegrationTests.Helpers.csproj",
+      "test\\TestCustomAuthorizerApp\\TestCustomAuthorizerApp.csproj",
+      "test\\TestCustomAuthorizerApp.IntegrationTests\\TestCustomAuthorizerApp.IntegrationTests.csproj",
       "test\\TestServerlessApp.IntegrationTests\\TestServerlessApp.IntegrationTests.csproj",
       "test\\TestServerlessApp.NET8\\TestServerlessApp.NET8.csproj",
       "test\\TestServerlessApp\\TestServerlessApp.csproj"
     ]
   }
-}
+}

Libraries/src/Amazon.Lambda.Annotations.SourceGenerator/Models/Attributes/AttributeModelBuilder.cs

@@ -54,6 +54,15 @@ public static AttributeModel Build(AttributeData att, GeneratorExecutionContext
                     Type = TypeModelBuilder.Build(att.AttributeClass, context)
                 };
             }
+            else if(att.AttributeClass.Equals(context.Compilation.GetTypeByMetadataName(TypeFullNames.FromCustomAuthorizerAttribute), SymbolEqualityComparer.Default))
+            {
+                var data = FromCustomAuthorizerAttributeBuilder.Build(att);
+                model = new AttributeModel<FromCustomAuthorizerAttribute>
+                {
+                    Data = data,
+                    Type = TypeModelBuilder.Build(att.AttributeClass, context)
+                };
+            }
             else if (att.AttributeClass.Equals(context.Compilation.GetTypeByMetadataName(TypeFullNames.HttpApiAttribute), SymbolEqualityComparer.Default))
             {
                 var data = HttpApiAttributeBuilder.Build(att);

Libraries/src/Amazon.Lambda.Annotations.SourceGenerator/Models/Attributes/FromCustomAuthorizerAttributeBuilder.cs

@@ -0,0 +1,22 @@
+using Amazon.Lambda.Annotations.APIGateway;
+using Microsoft.CodeAnalysis;
+
+namespace Amazon.Lambda.Annotations.SourceGenerator.Models.Attributes
+{
+    public class FromCustomAuthorizerAttributeBuilder
+    {
+        public static FromCustomAuthorizerAttribute Build(AttributeData att)
+        {
+            var data = new FromCustomAuthorizerAttribute();
+            foreach (var pair in att.NamedArguments)
+            {
+                if (pair.Key == nameof(data.Name) && pair.Value.Value is string value)
+                {
+                    data.Name = value;
+                }
+            }
+
+            return data;
+        }
+    }
+}

Libraries/src/Amazon.Lambda.Annotations.SourceGenerator/Templates/APIGatewaySetupParameters.tt

@@ -247,6 +247,157 @@
                 validationErrors.Add($"Value {__request__.Body} at 'body' failed to satisfy constraint: {e.Message}");
             }
 
+<#
+                }
+            }
+            else if (parameter.Attributes.Any(att => att.Type.FullName == TypeFullNames.FromCustomAuthorizerAttribute))
+            {
+                var fromAuthorizerAttribute = parameter.Attributes?.FirstOrDefault(att => att.Type.FullName == TypeFullNames.FromCustomAuthorizerAttribute) as AttributeModel<Amazon.Lambda.Annotations.APIGateway.FromCustomAuthorizerAttribute>;
+
+                // Use parameter name as key, if Name has not specified explicitly in the attribute definition.
+                var authKey = fromAuthorizerAttribute?.Data?.Name ?? parameter.Name;
+                // REST API and HTTP API v1 both use APIGatewayProxyRequest where RequestContext.Authorizer is a dictionary.
+                // Only HTTP API v2 uses APIGatewayHttpApiV2ProxyRequest with RequestContext.Authorizer.Lambda as the dictionary.
+                if(restApiAttribute != null || httpApiAttribute?.Data.Version == Amazon.Lambda.Annotations.APIGateway.HttpApiVersion.V1)
+                {
+#>
+            var <#= parameter.Name #> = default(<#= parameter.Type.FullName #>);
+            if (__request__.RequestContext?.Authorizer == null || __request__.RequestContext?.Authorizer.ContainsKey("<#= authKey #>") == false)
+            {
+                var __unauthorized__ = new <#= restApiAttribute != null || httpApiAttribute?.Data.Version == Amazon.Lambda.Annotations.APIGateway.HttpApiVersion.V1 ? "Amazon.Lambda.APIGatewayEvents.APIGatewayProxyResponse" : "Amazon.Lambda.APIGatewayEvents.APIGatewayHttpApiV2ProxyResponse" #>
+                {                    
+                    Headers = new Dictionary<string, string>
+                    {
+                        {"Content-Type", "application/json"},
+                        {"x-amzn-ErrorType", "AccessDeniedException"}
+                    },
+                    StatusCode = 401
+                };
+<#
+                    if(_model.LambdaMethod.ReturnsIHttpResults)
+                    {
+#>
+                var __unauthorizedStream__ = new System.IO.MemoryStream();
+                serializer.Serialize(__unauthorized__, __unauthorizedStream__);
+                __unauthorizedStream__.Position = 0;
+                return __unauthorizedStream__;
+<#
+                    }
+                    else
+                    {
+#>
+                return __unauthorized__;
+<#
+                    }
+#>
+            }
+
+            try
+            {
+                var __authValue_<#= parameter.Name #>__ = __request__.RequestContext.Authorizer["<#= authKey #>"];
+                <#= parameter.Name #> = (<#= parameter.Type.FullName #>)Convert.ChangeType(__authValue_<#= parameter.Name #>__?.ToString(), typeof(<#= parameter.Type.FullNameWithoutAnnotations #>));
+            }
+            catch (Exception e) when (e is InvalidCastException || e is FormatException || e is OverflowException || e is ArgumentException)
+            {
+                var __unauthorized__ = new <#= restApiAttribute != null || httpApiAttribute?.Data.Version == Amazon.Lambda.Annotations.APIGateway.HttpApiVersion.V1 ? "Amazon.Lambda.APIGatewayEvents.APIGatewayProxyResponse" : "Amazon.Lambda.APIGatewayEvents.APIGatewayHttpApiV2ProxyResponse" #>
+                {                    
+                    Headers = new Dictionary<string, string>
+                    {
+                        {"Content-Type", "application/json"},
+                        {"x-amzn-ErrorType", "AccessDeniedException"}
+                    },
+                    StatusCode = 401
+                };
+<#
+                    if(_model.LambdaMethod.ReturnsIHttpResults)
+                    {
+#>
+                var __unauthorizedStream__ = new System.IO.MemoryStream();
+                serializer.Serialize(__unauthorized__, __unauthorizedStream__);
+                __unauthorizedStream__.Position = 0;
+                return __unauthorizedStream__;
+<#
+                    }
+                    else
+                    {
+#>
+                return __unauthorized__;
+<#
+                    }
+#>
+            }
+
+<#
+                }
+                else
+                {
+#>
+            var <#= parameter.Name #> = default(<#= parameter.Type.FullName #>);
+            if (__request__.RequestContext?.Authorizer?.Lambda == null || __request__.RequestContext?.Authorizer?.Lambda.ContainsKey("<#= authKey #>") == false)
+            {
+                var __unauthorized__ = new <#= restApiAttribute != null || httpApiAttribute?.Data.Version == Amazon.Lambda.Annotations.APIGateway.HttpApiVersion.V1 ? "Amazon.Lambda.APIGatewayEvents.APIGatewayProxyResponse" : "Amazon.Lambda.APIGatewayEvents.APIGatewayHttpApiV2ProxyResponse" #>
+                {                    
+                    Headers = new Dictionary<string, string>
+                    {
+                        {"Content-Type", "application/json"},
+                        {"x-amzn-ErrorType", "AccessDeniedException"}
+                    },
+                    StatusCode = 401
+                };
+<#
+                    if(_model.LambdaMethod.ReturnsIHttpResults)
+                    {
+#>
+                var __unauthorizedStream__ = new System.IO.MemoryStream();
+                serializer.Serialize(__unauthorized__, __unauthorizedStream__);
+                __unauthorizedStream__.Position = 0;
+                return __unauthorizedStream__;
+<#
+                    }
+                    else
+                    {
+#>
+                return __unauthorized__;
+<#
+                    }
+#>
+            }
+
+            try
+            {
+                var __authValue_<#= parameter.Name #>__ = __request__.RequestContext.Authorizer.Lambda["<#= authKey #>"];
+                <#= parameter.Name #> = (<#= parameter.Type.FullName #>)Convert.ChangeType(__authValue_<#= parameter.Name #>__?.ToString(), typeof(<#= parameter.Type.FullNameWithoutAnnotations #>));
+            }
+            catch (Exception e) when (e is InvalidCastException || e is FormatException || e is OverflowException || e is ArgumentException)
+            {
+                var __unauthorized__ = new <#= restApiAttribute != null || httpApiAttribute?.Data.Version == Amazon.Lambda.Annotations.APIGateway.HttpApiVersion.V1 ? "Amazon.Lambda.APIGatewayEvents.APIGatewayProxyResponse" : "Amazon.Lambda.APIGatewayEvents.APIGatewayHttpApiV2ProxyResponse" #>
+                {                    
+                    Headers = new Dictionary<string, string>
+                    {
+                        {"Content-Type", "application/json"},
+                        {"x-amzn-ErrorType", "AccessDeniedException"}
+                    },
+                    StatusCode = 401
+                };
+<#
+                    if(_model.LambdaMethod.ReturnsIHttpResults)
+                    {
+#>
+                var __unauthorizedStream__ = new System.IO.MemoryStream();
+                serializer.Serialize(__unauthorized__, __unauthorizedStream__);
+                __unauthorizedStream__.Position = 0;
+                return __unauthorizedStream__;
+<#
+                    }
+                    else
+                    {
+#>
+                return __unauthorized__;
+<#
+                    }
+#>
+            }
+
 <#
                 }
             }
@@ -315,4 +466,4 @@
 
 <#
         }
-#>
+#>

Libraries/src/Amazon.Lambda.Annotations.SourceGenerator/TypeFullNames.cs

@@ -31,6 +31,7 @@ public static class TypeFullNames
         public const string FromHeaderAttribute = "Amazon.Lambda.Annotations.APIGateway.FromHeaderAttribute";
         public const string FromBodyAttribute = "Amazon.Lambda.Annotations.APIGateway.FromBodyAttribute";
         public const string FromRouteAttribute = "Amazon.Lambda.Annotations.APIGateway.FromRouteAttribute";
+        public const string FromCustomAuthorizerAttribute = "Amazon.Lambda.Annotations.APIGateway.FromCustomAuthorizerAttribute";
 
         public const string SQSEvent = "Amazon.Lambda.SQSEvents.SQSEvent";
         public const string SQSBatchResponse = "Amazon.Lambda.SQSEvents.SQSBatchResponse";

Libraries/src/Amazon.Lambda.Annotations/APIGateway/FromCustomAuthorizerAttribute.cs

@@ -0,0 +1,19 @@
+using System;
+
+namespace Amazon.Lambda.Annotations.APIGateway
+{
+    /// <summary>
+    /// Maps this parameter to a custom authorizer item
+    /// </summary>
+    /// <remarks>
+    /// Will try to get the specified key from Custom Authorizer values
+    /// </remarks>
+    [AttributeUsage(AttributeTargets.Parameter)]
+    public class FromCustomAuthorizerAttribute : Attribute, INamedAttribute
+    {
+        /// <summary>
+        /// Key of the value
+        /// </summary>
+        public string Name { get; set; }
+    }
+}

Libraries/src/Amazon.Lambda.Annotations/README.md

@@ -894,6 +894,22 @@ parameter to the `LambdaFunction` must be the event object and the event source
     * Map method parameter to HTTP request body. If parameter is a complex type then request body will be assumed to be JSON and deserialized into the type.
 * FromServices
     * Map method parameter to registered service in IServiceProvider
+* FromCustomAuthorizer
+    * Map method parameter to a custom authorizer context value. Use the `Name` property to specify the key in the authorizer context if it differs from the parameter name. Returns HTTP 401 Unauthorized if the key is not found or type conversion fails.
+
+Example using `FromCustomAuthorizer` to access values set by a custom Lambda authorizer:
+```csharp
+[LambdaFunction]
+[HttpApi(LambdaHttpMethod.Get, "/api/protected")]
+public async Task ProtectedEndpoint(
+    [FromCustomAuthorizer(Name = "userId")] string userId,
+    [FromCustomAuthorizer(Name = "tenantId")] int tenantId,
+    ILambdaContext context)
+{
+    context.Logger.LogLine($"User {userId} from tenant {tenantId}");
+    // userId and tenantId are automatically extracted from the custom authorizer context
+}
+```
 
 ### Customizing responses for API Gateway Lambda functions
 
@@ -940,4 +956,4 @@ The content type is determined using the following rules.
 
 ## Project References
 
-If API Gateway event attributes, such as `RestAPI` or `HttpAPI`, are being used then a package reference to `Amazon.Lambda.APIGatewayEvents` must be added to the project, otherwise the project will not compile. We do not include it by default in order to keep the `Amazon.Lambda.Annotations` library lightweight. 
+If API Gateway event attributes, such as `RestAPI` or `HttpAPI`, are being used then a package reference to `Amazon.Lambda.APIGatewayEvents` must be added to the project, otherwise the project will not compile. We do not include it by default in order to keep the `Amazon.Lambda.Annotations` library lightweight.

Libraries/test/Amazon.Lambda.Annotations.SourceGenerators.Tests/Amazon.Lambda.Annotations.SourceGenerators.Tests.csproj

@@ -168,6 +168,9 @@
     </ItemGroup>
 
     <ItemGroup>
+      <None Remove="Snapshots\ServerlessTemplates\authorizerHttpApi.template" />
+      <None Remove="Snapshots\ServerlessTemplates\authorizerHttpApiV1.template" />
+      <None Remove="Snapshots\ServerlessTemplates\authorizerRest.template" />
       <None Remove="Snapshots\ServerlessTemplates\customizeResponse.template" />
       <None Remove="Snapshots\ServerlessTemplates\dynamicexample.template" />
       <None Remove="Snapshots\ServerlessTemplates\intrinsicexample.template" />