version info in response headers

src/Api/Startup.cs

@@ -158,11 +158,8 @@ namespace Bit.Api
                 })
                 .AddDebug();
 
-            // Forwarded headers
-            if(!env.IsDevelopment())
-            {
-                app.UseForwardedHeadersForAzure();
-            }
+            // Default Middleware
+            app.UseDefaultMiddleware(env);
 
             if(!globalSettings.SelfHosted)
             {

src/Billing/Startup.cs

@@ -69,11 +69,8 @@ namespace Bit.Billing
                 app.UseDeveloperExceptionPage();
             }
 
-            // Forwarded headers
-            if(!env.IsDevelopment())
-            {
-                app.UseForwardedHeadersForAzure();
-            }
+            // Default Middleware
+            app.UseDefaultMiddleware(env);
 
             app.UseMvc();
         }

src/Core/Models/Api/Response/VersionResponseModel.cs

@@ -1,5 +1,5 @@
 using System;
-using System.Reflection;
+using Bit.Core.Utilities;
 
 namespace Bit.Core.Models.Api
 {
@@ -8,13 +8,12 @@ namespace Bit.Core.Models.Api
         public VersionResponseModel()
             : base("version")
         {
-            Version = Assembly.GetEntryAssembly()
-                .GetCustomAttribute<AssemblyInformationalVersionAttribute>()
-                .InformationalVersion;
-            VersionInt = Convert.ToInt32(Version.Replace(".", string.Empty));
+            var info = CoreHelpers.GetVersionInfo();
+            Version = info.version;
+            VersionWeight = info.versionWeight;
         }
 
         public string Version { get; set; }
-        public int VersionInt { get; set; }
+        public int VersionWeight { get; set; }
     }
 }

src/Core/Utilities/CoreHelpers.cs

@@ -19,6 +19,8 @@ namespace Bit.Core.Utilities
         private static readonly long _baseDateTicks = new DateTime(1900, 1, 1).Ticks;
         private static readonly DateTime _epoc = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
         private static readonly Random _random = new Random();
+        private static string _version;
+        private static int _versionWeight;
 
         /// <summary>
         /// Generate sequential Guid for Sql Server.
@@ -372,5 +374,26 @@ namespace Bit.Core.Utilities
 
             return val.ToString();
         }
+
+        public static (string version, int versionWeight) GetVersionInfo()
+        {
+            if(string.IsNullOrWhiteSpace(_version))
+            {
+                _version = Assembly.GetEntryAssembly()
+                    .GetCustomAttribute<AssemblyInformationalVersionAttribute>()
+                    .InformationalVersion;
+
+                var dashIndex = _version.IndexOf('-');
+                var trimmedVersion = dashIndex > 0 ? _version.Substring(0, dashIndex) : _version;
+
+                var semVerParts = trimmedVersion.Split('.').Reverse().ToArray();
+                for(var i = 0; i < semVerParts.Length; i++)
+                {
+                    _versionWeight += (i + 1) * Convert.ToInt32(semVerParts[i]);
+                }
+            }
+
+            return (_version, _versionWeight);
+        }
     }
 }

src/Core/Utilities/ServiceCollectionExtensions.cs

@@ -15,12 +15,14 @@ using Microsoft.AspNetCore.HttpOverrides;
 using Microsoft.AspNetCore.Identity;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.AspNetCore.Http;
 #if NET461
 using Microsoft.WindowsAzure.Storage;
 #endif
 using System;
 using System.IO;
 using SqlServerRepos = Bit.Core.Repositories.SqlServer;
+using System.Threading.Tasks;
 
 namespace Bit.Core.Utilities
 {
@@ -267,19 +269,35 @@ namespace Bit.Core.Utilities
             return globalSettings;
         }
 
-        public static void UseForwardedHeadersForAzure(this IApplicationBuilder app)
+        public static void UseDefaultMiddleware(this IApplicationBuilder app, IHostingEnvironment env)
         {
-            // ref: https://github.com/aspnet/Docs/issues/2384
-            var forwardOptions = new ForwardedHeadersOptions
+            if(!env.IsDevelopment())
             {
-                ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto,
-                RequireHeaderSymmetry = false
-            };
+                // Adjust headers for proxy.
+                // ref: https://github.com/aspnet/Docs/issues/2384
+                var forwardOptions = new ForwardedHeadersOptions
+                {
+                    ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto,
+                    RequireHeaderSymmetry = false
+                };
+                forwardOptions.KnownNetworks.Clear();
+                forwardOptions.KnownProxies.Clear();
+                app.UseForwardedHeaders(forwardOptions);
+            }
 
-            forwardOptions.KnownNetworks.Clear();
-            forwardOptions.KnownProxies.Clear();
+            // Add version information to response headers
+            app.Use(async (httpContext, next) =>
+            {
+                httpContext.Response.OnStarting((state) =>
+                {
+                    var info = CoreHelpers.GetVersionInfo();
+                    httpContext.Response.Headers.Append("Version", info.version);
+                    httpContext.Response.Headers.Append("VersionWeight", info.versionWeight.ToString());
+                    return Task.FromResult(0);
+                }, null);
 
-            app.UseForwardedHeaders(forwardOptions);
+                await next.Invoke();
+            });
         }
     }
 }

src/Identity/Startup.cs

@@ -72,11 +72,8 @@ namespace Bit.Identity
                 .AddConsole()
                 .AddDebug();
 
-            // Forwarded headers
-            if(!env.IsDevelopment())
-            {
-                app.UseForwardedHeadersForAzure();
-            }
+            // Default Middleware
+            app.UseDefaultMiddleware(env);
 
             // Add IdentityServer to the request pipeline.
             app.UseIdentityServer();