Series of functions and classes for using SSRS to run reports from inside an ASP.NET Core application

EndpointBehavior.cs

using System.ServiceModel.Channels;
using System.ServiceModel.Description;
using System.ServiceModel.Dispatcher;

internal class ReportingServicesEndpointBehavior : IEndpointBehavior
{
    public void AddBindingParameters(ServiceEndpoint endpoint, BindingParameterCollection bindingParameters) { }

    public void ApplyClientBehavior(ServiceEndpoint endpoint, ClientRuntime clientRuntime)
    {
        clientRuntime.ClientMessageInspectors.Add(new ReportingServicesExecutionInspector());
    }

    public void ApplyDispatchBehavior(ServiceEndpoint endpoint, EndpointDispatcher endpointDispatcher) { }

    public void Validate(ServiceEndpoint endpoint) { }
}

MessageInspector.cs

using System.ServiceModel.Channels;
using System.ServiceModel.Description;
using System.ServiceModel.Dispatcher;

internal class ReportingServicesExecutionInspector : IClientMessageInspector
{
    private MessageHeaders headers;

    public void AfterReceiveReply(ref Message reply, object correlationState)
    {
        var index = reply.Headers.FindHeader("ExecutionHeader", "http://schemas.microsoft.com/sqlserver/2005/06/30/reporting/reportingservices");
        if (index >= 0 && headers == null)
        {
            headers = new MessageHeaders(MessageVersion.Soap11);
            headers.CopyHeaderFrom(reply, reply.Headers.FindHeader("ExecutionHeader", "http://schemas.microsoft.com/sqlserver/2005/06/30/reporting/reportingservices"));
        }
    }

    public object BeforeSendRequest(ref Message request, IClientChannel channel)
    {
        if(headers != null)
            request.Headers.CopyHeadersFrom(headers);

        return Guid.NewGuid(); //https://msdn.microsoft.com/en-us/library/system.servicemodel.dispatcher.iclientmessageinspector.beforesendrequest(v=vs.110).aspx#Anchor_0
    }
}

ReportFunctions.cs

/*
The below code depends on you having the supporting WCF reference to a SSRS endpoint already in your project. This can be done using
https://marketplace.visualstudio.com/items?itemName=WCFCORETEAM.VisualStudioWCFConnectedService
--or--
using SvcUtil.exe
*/

public async Task<byte[]> RenderReport(string report, IDictionary<string, object> parameters, string exportFormat = null)
{
    //My binding setup, since ASP.NET Core apps don't use a web.config file
    var binding = new BasicHttpBinding(BasicHttpSecurityMode.TransportCredentialOnly);
    binding.Security.Transport.ClientCredentialType = HttpClientCredentialType.Ntlm;
    binding.MaxReceivedMessageSize = 10485760; //I wanted a 10MB size limit on response to allow for larger PDFs

    //Create the execution service SOAP Client
    var rsExec = new ReportExecutionServiceSoapClient(binding, new EndpointAddress(reportingServicesUrl));

    //Setup access credentials. I use windows credentials, yours may differ
    var clientCredentials = new NetworkCredential(reportingServicesUserName, reportingServicesPassword, reportingServicesDomain);
    rsExec.ClientCredentials.Windows.AllowedImpersonationLevel = System.Security.Principal.TokenImpersonationLevel.Impersonation;
    rsExec.ClientCredentials.Windows.ClientCredential = clientCredentials;

    //This handles the problem of "Missing session identifier"
    rsExec.Endpoint.Behaviors.Add(new ReportingServicesEndpointBehavior());

    //Load the report
    var taskLoadReport = await rsExec.LoadReportAsync(report, null);

    //Set the parameteres asked for by the report
    var reportParameters = taskLoadReport.Parameters.Where(x => parameters.ContainsKey(x.Name)).Select(x => new ParameterValue() { Name = x.Name, Value = parameters[x.Name].ToString() }).ToArray();
    await rsExec.SetExecutionParametersAsync(reportParameters, "en-us");

    //run the report
    const string deviceInfo = @"<DeviceInfo><Toolbar>False</Toolbar></DeviceInfo>";
    var response = await rsExec.RenderAsync(new RenderRequest(exportFormat ?? "PDF", deviceInfo));

    //spit out the result
    return response.Result;
}