varhttpSysAssembly=typeof(Microsoft.AspNetCore.Server.HttpSys.HttpSysOptions).Assembly;varhttpSysPropertyFeatureType=httpSysAssembly.GetType("Microsoft.AspNetCore.Server.HttpSys.IHttpSysRequestPropertyFeature");varhttpSysPropertyFeature=context.Features[httpSysPropertyFeatureType]!;varmethod=httpSysPropertyFeature.GetType().GetMethod("TryGetTlsClientHello",BindingFlags.Instance|BindingFlags.Public|BindingFlags.NonPublic);// invoke first time to get required sizebyte[]bytes=Array.Empty<byte>();varparameters=newobject[]{bytes,0};varres=(bool)method.Invoke(httpSysPropertyFeature,parameters);// fetching out parameter only works by looking into parameters array of objectsvarbytesReturned=(int)parameters[1];bytes=ArrayPool<byte>.Shared.Rent(bytesReturned);parameters=[bytes,0];// correct input nowres=(bool)method.Invoke(httpSysPropertyFeature,parameters);// this is the span representing the TLS Client Hello bytes onlyvartlsClientHelloBytes=((byte[])parameters[0]).AsSpan(0,bytesReturned);awaitcontext.Response.WriteAsync($"TlsBytes:{string.Join(" ",tlsClientHelloBytes.Slice(0,10).ToArray())}; full length ={bytesReturned}");ArrayPool<byte>.Shared.Return(bytes);