RegisterSigV4aProvider doesn't work with AOT

[jamiewinder]

Describe the bug

I have a simple AOT application which sending an event to EventBridge using a global endpoint.

If I run this application, I get an error at runtime:

Unhandled Exception: Amazon.RuntimeDependencies.MissingRuntimeDependencyException: Operation failed because of a missing runtime dependency. In Native AOT builds runtime dependencies can not be dynamically loaded from assembles. Instead the runtime dependency needs to be explicitly registered. To complete this operation register an instance of Amazon.Extensions.CrtIntegration.CrtAWS4aSigner from package AWSSDK.Extensions.CrtIntegration using the operation Amazon.RuntimeDependencies.GlobalRuntimeDependencyRegistry.Instance.RegisterSigV4aProvider.

If I add what I believe to be the required code (see repro below) I get another error:

Unhandled Exception: System.TypeInitializationException: A type initializer threw an exception. To determine which type, inspect the InnerException's StackTrace property.
---> System.NullReferenceException: Object reference not set to an instance of an object.
at Aws.Crt.NativeAPI.BindImplD + 0x65
at Aws.Crt.Auth.AwsSigner.API..cctor() + 0x19

Could be I'm doing something wrong, but the registration matches what the error tells me to do.

Regression Issue

• Select this option if this issue appears to be a regression.

Expected Behavior

RegisterSigV4aProvider should allow Event Bridge global endpoints to be used.

Current Behavior

RegisterSigV4aProvider results in another error.

Reproduction Steps

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net8.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
    <PublishAot>true</PublishAot>
    <InvariantGlobalization>true</InvariantGlobalization>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="AWSSDK.EventBridge" Version="4.0.3.5" />
    <PackageReference Include="AWSSDK.Extensions.CrtIntegration" Version="4.0.0" />
  </ItemGroup>

</Project>

using Amazon.EventBridge;
using Amazon.EventBridge.Model;
using Amazon.Extensions.CrtIntegration;
using Amazon.RuntimeDependencies;

GlobalRuntimeDependencyRegistry.Instance.RegisterSigV4aProvider(context =>
{
    return new CrtAWS4aSigner(context.SigV4aCrtSignerContextData.SignPayload);
});

var client = new AmazonEventBridgeClient();

var request = new PutEventsRequest
{
    EndpointId = "my-endpoint-id",
    Entries =
    [
        new PutEventsRequestEntry
        {
            Detail = "TEST",
            DetailType = "MyDetailType",
            Source = "MySource",
            EventBusName = "default"
        }
    ]
};

var response = await client.PutEventsAsync(request);

Console.WriteLine(response.HttpStatusCode);

If this is published and ran, the error will occur.

Possible Solution

No response

Additional Information/Context

No response

AWS .NET SDK and/or Package version used

AWSSDK.EventBridge 4.0.3.5
AWSSDK.Extensions.CrtIntegration 4.0.0

Targeted .NET Platform

.NET 8

Operating System and version

Windows 10 / Linux

[normj]

@jamiewinder This is a miss on our part that we haven't worked with the team that owns the dependent AWSCRT NuGet packages that provide the SigV4a implementation. The AWSCRT packages provide a native C implementation of the SigV4a algorithm.

With V4 of the SDK we now have all of the required crypto algorithms we need to make a .NET based SigV4a implementation. We are working on getting that work scheduled which will make it easier to have a trim safe SigV4a implementation. Until then that probably means SigV4a based operations will not be accessible for Native AOT.

[teo-tsirpanis]

The exception originates from AWSCRT, whose .NET interop code is not very friendly to AOT. I have thought about fixing it, but with the managed SigV4a signer in sight (#3923) it's better to focus on removing the AWSCRT dependency for SigV4a in the first place.

I would suggest to close this issue and open one in https://github.com/awslabs/aws-crt-dotnet; the same problem also exists with CRT's checksum APIs.