HexaEightMiddleware 1.6.55

HexaEight Middleware

How To Use This Library

Sample Middleware Code (Startup and Configuration Section)

public class Startup
{
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.Add(new ServiceDescriptor(typeof(HexaEightResource), new HexaEightResource("18ADCEA59T56FE1427ABC652763DFC47134BDFDBC", "https://tokenserverurl:8443")));
            services.AddSingleton<IAuthenticationService, AuthenticationMiddleware>();
            services.AddAuthentication();
            services.AddAuthorization();
            services.AddCors();
            services.AddControllers();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            //Enable CORS for all origns including credentials. We will validate the user agents in the authentication section
            app.UseCors(x => x
                .AllowAnyMethod()
                .AllowAnyHeader()
                .SetIsOriginAllowed(origin => true)
                .AllowCredentials());

            //Add HexaEight Middleware first in the pipeline so that valid request can be authenticated.

            app.UseMiddleware<HexaEightEngine.Middleware>();
            app.UseRouting();
            app.Use(async (context, next) =>
            {
                await next();

                if (context.Response.StatusCode == (int)HttpStatusCode.Unauthorized)
                {
                    context.Response.StatusCode = (int)HttpStatusCode.OK;
                    await context.Response.Body.WriteAsync(Encoding.UTF8.GetBytes("UnAuthorized - Access Denied"));
                }

            });

            app.UseAuthentication();
            app.UseAuthorization();
            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }
}

Sample Weather Controller Code with Authorization for Get and Post

    public class WeatherForecast
    {
        public DateTime Date { get; set; }

        public int TemperatureC { get; set; }

        public int TemperatureF => 32 + (int)(TemperatureC / 0.5556);

        public string Summary { get; set; }
        
        public bool isauthenticated { get; set; }
        public string loggedinuser { get; set; }
        public string location { get; set; }


    }

namespace HexaEight_Middleware_SampleDemo.Controllers
{
    [ApiController]
    [Route("[controller]")]
    public class WeatherForecastController : ControllerBase
    {
        private static readonly string[] Summaries = new[]
        {
            "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"
        };


        private static readonly string[] locations = new[]
        {
            "Aberdeen", "Anacortes","Arlington", "Auburn","Battle Ground","Bellevue","Bellingham","Bonney Lake","Bothell","Bremerton","Burien"
        };

        private readonly ILogger<WeatherForecastController> _logger;

        public WeatherForecastController(ILogger<WeatherForecastController> logger)
        {
            _logger = logger;
        }

        [HttpGet]
        public IEnumerable<WeatherForecast> Get()
        {
            var rng = new Random();
            return Enumerable.Range(1, 5).Select(index => new WeatherForecast
            {
                isauthenticated = false,
                loggedinuser = "",
                Date = DateTime.Now.AddDays(index),
                TemperatureC = rng.Next(-20, 55),
                location = locations[rng.Next(locations.Length)],
                 Summary = Summaries[rng.Next(Summaries.Length)]
            })
            .ToArray();
        }

        [HttpGet("{resource}")]
        [Authorize(AuthenticationSchemes = "Bearer")]
        public IEnumerable<WeatherForecast> Get(string resource)
        {
            var rng = new Random();
                return Enumerable.Range(1, 1).Select(index => new WeatherForecast
                {
                    isauthenticated = true,
                    loggedinuser = HttpContext.User.Identity.Name.ToString(),
                    Date = DateTime.Now.AddDays(index),
                    TemperatureC = rng.Next(-20, 55),
                    location = resource,
                    Summary = Summaries[rng.Next(Summaries.Length)]
                })
                .ToArray();
        }


        [HttpPost("{resource}")]
        [Authorize(AuthenticationSchemes = "Bearer")]
        public async Task<IEnumerable<WeatherForecast>> Post(string resource)
        {

            string body = "";
            using (StreamReader stream = new StreamReader(HttpContext.Request.Body))
            {
                body = await stream.ReadToEndAsync();
            }
            body = body.ToString().TrimEnd('\0').Trim();

            var rng = new Random();
            return Enumerable.Range(1, 1).Select(index => new WeatherForecast
            {
                isauthenticated = true,
                loggedinuser = HttpContext.User.Identity.Name.ToString(),
                Date = DateTime.Now.AddDays(index),
                TemperatureC = rng.Next(-20, 55),
                location = body,
                Summary = Summaries[rng.Next(Summaries.Length)]
            })
            .ToArray();
        }


    }
}

Sample Authentication Middleware Code For Additional Authorization

public class AuthenticationMiddleware : IAuthenticationService
{
        static string ComputeSHA512(string s)
        {
            StringBuilder sb = new StringBuilder();
            using (SHA512 sha512 = SHA512.Create())
            {
                byte[] hashValue = sha512.ComputeHash(Encoding.UTF8.GetBytes(s));
                foreach (byte b in hashValue)
                {
                    sb.Append($"{b:X2}");
                }
            }

            return sb.ToString();
        }
        public Task<AuthenticateResult> AuthenticateAsync(HttpContext context, string scheme)
        {
            try
            {
                if (context.User.Identity.IsAuthenticated && context.User.Identity.AuthenticationType == "HexaEight Identity")
                {

                    try
                    {
                        // Check 1: Weed out MITM. This will ensure replaying the same request through some other orign wont work.
                        // Note: This Check wont work for desktop and mobile client apps since orign is expected to be null. Use Check 2 to validate the request
                        if (ComputeSHA512(context.Request.Headers["Origin"].FirstOrDefault().Trim().Replace("https://", "").Replace("http://", "").ToLower()) != context.User.Claims.FirstOrDefault(c => c.Type == "OriginHash").Value)
                        {
                            return Task.FromResult(AuthenticateResult.Fail("UnAuthorized Request - Access Denied"));
                        }
                    }
                    catch { }

                    // Check 2: Validate if the request origniated through list a list of accepted user agents/client applications hash values.
                    // For example if you are expecting api requests from www.client.com, www.thirdparty.com you will add the 512 hash of www.client.com to below list.
                    // For Mobile and Desktop apps, generate the 512 Hash of the executuable and add it below.
                    var listofclienthashes = new string[] { "B5E57824692A50458E29E1E35FCAFE1F55DE18C35DBE0901B5AF887BAC068D08E3B34CEA2B722395D0E4CDFC1292D5E8950894D9FFFB48E834026789CC5F1DCA" };

                    if (!listofclienthashes.Any(s => s.Contains(context.User.Claims.FirstOrDefault(c => c.Type == "OriginHash").Value)))
                    {
                        return Task.FromResult(AuthenticateResult.Fail("UnAuthorized User Agent - Access Denied"));
                    }

                    // Check3 : Validate if the request is more than X seconds, if so reject the request.
                    // The below test tests to see if the request is received after 10 seconds, if so the requst is rejected
                    if (Int64.Parse((context.User.Claims.FirstOrDefault(c => c.Type == "RequestReceivedAt").Value)) - Int64.Parse((context.User.Claims.FirstOrDefault(c => c.Type == "RequestTimeStamp").Value)) > 10)
                    {
                        return Task.FromResult(AuthenticateResult.Fail("Expired Request - Access Denied"));
                    }

                    // TBD -> Check 4 : While Check3 will Prevent most replay attacks, using a  bloom filter based on 'RequestHash' value available in the user claims, can repel all replay attacks

                    AuthenticationTicket at = new AuthenticationTicket(context.User, "HexaEight");
                    return Task.FromResult(AuthenticateResult.Success(at));
                }
                return Task.FromResult(AuthenticateResult.Fail("UnAuthorized"));
            }
            catch
            {
                return Task.FromResult(AuthenticateResult.Fail("UnAuthorized"));
            }


        }

        public Task ChallengeAsync(HttpContext context, string scheme, AuthenticationProperties properties)
        {
            context.Response.StatusCode = (int)HttpStatusCode.Unauthorized;
            return Task.CompletedTask;
        }

        public Task ForbidAsync(HttpContext context, string scheme, AuthenticationProperties properties)
        {
            throw new NotImplementedException();
        }

        public Task SignInAsync(HttpContext context, string scheme, ClaimsPrincipal principal, AuthenticationProperties properties)
        {

            return Task.CompletedTask;
        }

        public Task SignOutAsync(HttpContext context, string scheme, AuthenticationProperties properties)
        {
            throw new NotImplementedException();
        }
}

NOTE: Please be aware that, at the moment, HexaEight Middleware accommodates Controller responses ONLY in Array or IEnumerable formats.