Queue ip addresses for block whenever they exceed the rate limit too much

src/Api/Middleware/CustomIpRateLimitMiddleware.cs

@@ -1,6 +1,8 @@
 using AspNetCoreRateLimit;
 using Bit.Api.Models.Response;
+using Bit.Core.Services;
 using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Caching.Memory;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using Newtonsoft.Json;
@@ -11,17 +13,25 @@ namespace Bit.Api.Middleware
     public class CustomIpRateLimitMiddleware : IpRateLimitMiddleware
     {
         private readonly IpRateLimitOptions _options;
+        private readonly IMemoryCache _memoryCache;
+        private readonly IBlockIpService _blockIpService;
+        private readonly ILogger<IpRateLimitMiddleware> _logger;
 
         public CustomIpRateLimitMiddleware(
+            IMemoryCache memoryCache,
+            IBlockIpService blockIpService,
             RequestDelegate next,
             IOptions<IpRateLimitOptions> options,
             IRateLimitCounterStore counterStore,
             IIpPolicyStore policyStore,
             ILogger<IpRateLimitMiddleware> logger,
-            IIpAddressParser ipParser = null
-            ) : base(next, options, counterStore, policyStore, logger, ipParser)
+            IIpAddressParser ipParser = null)
+            : base(next, options, counterStore, policyStore, logger, ipParser)
         {
+            _memoryCache = memoryCache;
+            _blockIpService = blockIpService;
             _options = options.Value;
+            _logger = logger;
         }
 
         public override Task ReturnQuotaExceededResponse(HttpContext httpContext, RateLimitRule rule, string retryAfter)
@@ -35,5 +45,27 @@ namespace Bit.Api.Middleware
             var errorModel = new ErrorResponseModel { Message = message };
             return httpContext.Response.WriteAsync(JsonConvert.SerializeObject(errorModel));
         }
+
+        public override void LogBlockedRequest(HttpContext httpContext, ClientRequestIdentity identity,
+            RateLimitCounter counter, RateLimitRule rule)
+        {
+            base.LogBlockedRequest(httpContext, identity, counter, rule);
+            var key = $"blockedIp_{identity.ClientIp}";
+
+            int blockedCount;
+            _memoryCache.TryGetValue(key, out blockedCount);
+
+            blockedCount++;
+            if(blockedCount > 10)
+            {
+                _blockIpService.BlockIpAsync(identity.ClientIp, false);
+                _logger.LogDebug("Blocked " + identity.ClientIp);
+            }
+            else
+            {
+                _memoryCache.Set(key, blockedCount,
+                    new MemoryCacheEntryOptions().SetSlidingExpiration(new System.TimeSpan(0, 5, 0)));
+            }
+        }
     }
 }

src/Api/Startup.cs

@@ -138,6 +138,7 @@ namespace Bit.Api
             services.AddScoped<IUserService, UserService>();
             services.AddScoped<IPushService, PushService>();
             services.AddScoped<IDeviceService, DeviceService>();
+            services.AddScoped<IBlockIpService, AzureBlockIpService>();
 
             // Cors
             services.AddCors(config =>

src/Api/settings.json

@@ -23,6 +23,9 @@
       "gcmSenderId": "SECRET",
       "gcmApiKey": "SECRET",
       "gcmAppPackageName": "com.x8bit.bitwarden"
+    },
+    "storage": {
+      "connectionString": "SECRET"
     }
   },
   "IpRateLimitOptions": {

src/Core/GlobalSettings.cs

@@ -8,14 +8,19 @@
         public virtual SqlServerSettings SqlServer { get; set; } = new SqlServerSettings();
         public virtual MailSettings Mail { get; set; } = new MailSettings();
         public virtual LoggrSettings Loggr { get; set; } = new LoggrSettings();
-        public virtual CacheSettings Cache { get; set; } = new CacheSettings();
         public virtual PushSettings Push { get; set; } = new PushSettings();
+        public virtual StorageSettings Storage { get; set; } = new StorageSettings();
 
         public class SqlServerSettings
         {
             public string ConnectionString { get; set; }
         }
 
+        public class StorageSettings
+        {
+            public string ConnectionString { get; set; }
+        }
+
         public class MailSettings
         {
             public string ApiKey { get; set; }
@@ -28,12 +33,6 @@
             public string ApiKey { get; set; }
         }
 
-        public class CacheSettings
-        {
-            public string ConnectionString { get; set; }
-            public int Database { get; set; }
-        }
-
         public class PushSettings
         {
             public string ApnsCertificateThumbprint { get; set; }

src/Core/Services/AzureBlockIpService.cs

@@ -0,0 +1,37 @@
+using System.Threading.Tasks;
+using Microsoft.WindowsAzure.Storage;
+using Microsoft.WindowsAzure.Storage.Queue;
+using System;
+
+namespace Bit.Core.Services
+{
+    public class AzureBlockIpService : IBlockIpService
+    {
+        private CloudQueue _blockIpQueue;
+        private CloudQueue _unblockIpQueue;
+
+        public AzureBlockIpService(
+            GlobalSettings globalSettings)
+        {
+            var storageAccount = CloudStorageAccount.Parse(globalSettings.Storage.ConnectionString);
+            var queueClient = storageAccount.CreateCloudQueueClient();
+
+            _blockIpQueue = queueClient.GetQueueReference("blockip");
+            _blockIpQueue.CreateIfNotExists();
+
+            _unblockIpQueue = queueClient.GetQueueReference("unblockip");
+            _unblockIpQueue.CreateIfNotExists();
+        }
+
+        public async Task BlockIpAsync(string ipAddress, bool permanentBlock)
+        {
+            var message = new CloudQueueMessage(ipAddress);
+            await _blockIpQueue.AddMessageAsync(message);
+
+            if(!permanentBlock)
+            {
+                await _unblockIpQueue.AddMessageAsync(message, null, new TimeSpan(12, 0, 0), null, null);
+            }
+        }
+    }
+}

src/Core/Services/IBlockIpService.cs

@@ -0,0 +1,10 @@
+using System;
+using System.Threading.Tasks;
+
+namespace Bit.Core.Services
+{
+    public interface IBlockIpService
+    {
+        Task BlockIpAsync(string ipAddress, bool permanentBlock);
+    }
+}

src/Core/project.json

@@ -8,7 +8,8 @@
     "DataTableProxy": "1.2.0",
     "Sendgrid": "6.3.4",
     "StackExchange.Redis": "1.0.488",
-    "PushSharp": "4.0.10"
+    "PushSharp": "4.0.10",
+    "WindowsAzure.Storage": "7.2.1"
   },
 
   "frameworks": {