Add support for NativeAot

[wu-yafeng]

NativeAot support #34

[wu-yafeng]

I conducted manual testing based on the FIDOUI program and it looks good.

I think it's necessary to enable Github Action for PR

[wu-yafeng]

Consider upgrade to net10 for IsAotCompatible assembly metadata support.

see https://learn.microsoft.com/en-us/dotnet/core/deploying/native-aot/?tabs=windows%2Cnet8#verify-referenced-assemblies-are-aot-compatible

The IsAotCompatible assembly metadata was introduced in .NET 10. Libraries that were published targeting earlier versions of .NET won't have this attribute, even if they were built with true.

[MichaelGrafnetter]

Thanks for the PR, @wu-yafeng . I suspect that migration from DllImport to LibraryImport would need to be done as well to support AOT.

[wu-yafeng]

I am not good at the P/Invoke, but I have reviewed some articles and complied some work that needs tobe done to migrate from DllImport to LibraryImport:

• replace DllImport to LibraryImport
• Implement CustomMarshaller for non-bittable class (such as RelyingPartyInformation.)

Example:

 [LibraryImport(WebAuthn, EntryPoint = "WebAuthNAuthenticatorMakeCredential")]
 [DefaultDllImportSearchPaths(DllImportSearchPath.System32)]
 public static partial HResult AuthenticatorMakeCredential(
     WindowHandle windowHandle,
     [MarshalUsing(typeof(ReplyingPartyInformationMarshaler))] RelyingPartyInformation rpInformation,
     ... // other parameter with MarshalUsing
 );


[CustomMarshaller(typeof(RelyingPartyInformation), MarshalMode.Default, typeof(ReplyingPartyInformationMarshaler))]
internal static unsafe class ReplyingPartyInformationMarshaler
{
    internal static IntPtr ConvertToUnmanaged(RelyingPartyInformation rpInfo)
    {
        var structure = new WEBAUTHN_RP_ENTITY_INFORMATION()
        {
            dwVersion = (uint)rpInfo.Version,
            pwszIcon = Utf16StringMarshaller.ConvertToUnmanaged(rpInfo.Icon),
            pwszId = Utf16StringMarshaller.ConvertToUnmanaged(rpInfo.Id),
            pwszName = Utf16StringMarshaller.ConvertToUnmanaged(rpInfo.Name),
        };

        IntPtr result = Marshal.AllocHGlobal(Marshal.SizeOf<WEBAUTHN_RP_ENTITY_INFORMATION>());

        Marshal.StructureToPtr(structure, result, false);

        return result;
    }

    public static void Free(IntPtr ptr)
    {
        Marshal.FreeHGlobal(ptr);
    }

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
    partial struct WEBAUTHN_RP_ENTITY_INFORMATION
    {
        internal uint dwVersion;
        internal ushort* pwszIcon;
        internal ushort* pwszId;
        internal ushort* pwszName;
    }
}

[MichaelGrafnetter]

@wu-yafeng You are right. P/Invoke without memory leaks was the hardest thing to implement. Duplicate method signatures are needed as well, see a code snippet from a different project of mine:

#if NET7_0_OR_GREATER
    [LibraryImport("Advapi.dll", SetLastError = true)]
    internal static partial NtStatus LsaClose(IntPtr handle);
#else
    [DllImport("Advapi.dll", SetLastError = true)]
    internal static extern NtStatus LsaClose(IntPtr handle);
#endif