From 14fd7e28018dc7aa27157f237f2c617e684e5c1d Mon Sep 17 00:00:00 2001
From: Kyle Spearrin <kyle.spearrin@gmail.com>
Date: Mon, 11 Mar 2019 23:31:45 -0400
Subject: [PATCH] throttle block messages and base64 encode them

---
 .../AzureQueueBlockIpService.cs               | 17 ++++++++++++----
 src/Core/Utilities/CoreHelpers.cs             | 20 +++++++++++++++++++
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/src/Core/Services/Implementations/AzureQueueBlockIpService.cs b/src/Core/Services/Implementations/AzureQueueBlockIpService.cs
index 5331497d49..00574f39ae 100644
--- a/src/Core/Services/Implementations/AzureQueueBlockIpService.cs
+++ b/src/Core/Services/Implementations/AzureQueueBlockIpService.cs
@@ -2,6 +2,7 @@
 using Microsoft.WindowsAzure.Storage;
 using Microsoft.WindowsAzure.Storage.Queue;
 using System;
+using Bit.Core.Utilities;
 
 namespace Bit.Core.Services
 {
@@ -10,6 +11,7 @@ namespace Bit.Core.Services
         private readonly CloudQueue _blockIpQueue;
         private readonly CloudQueue _unblockIpQueue;
         private bool _didInit = false;
+        private Tuple<string, bool, DateTime> _lastBlock;
 
         public AzureQueueBlockIpService(
             GlobalSettings globalSettings)
@@ -24,13 +26,20 @@ namespace Bit.Core.Services
         public async Task BlockIpAsync(string ipAddress, bool permanentBlock)
         {
             await InitAsync();
-            var blockMessage = new CloudQueueMessage(ipAddress);
-            await _blockIpQueue.AddMessageAsync(blockMessage);
+            var now = DateTime.UtcNow;
+            if(_lastBlock != null && _lastBlock.Item1 == ipAddress && _lastBlock.Item2 == permanentBlock &&
+                (now - _lastBlock.Item3) < TimeSpan.FromMinutes(1))
+            {
+                // Already blocked this IP recently.
+                return;
+            }
 
+            _lastBlock = new Tuple<string, bool, DateTime>(ipAddress, permanentBlock, now);
+            var message = new CloudQueueMessage(CoreHelpers.Base64UrlEncodeString(ipAddress));
+            await _blockIpQueue.AddMessageAsync(message);
             if(!permanentBlock)
             {
-                var unblockMessage = new CloudQueueMessage(ipAddress);
-                await _unblockIpQueue.AddMessageAsync(unblockMessage, null, new TimeSpan(0, 15, 0), null, null);
+                await _unblockIpQueue.AddMessageAsync(message, null, new TimeSpan(0, 15, 0), null, null);
             }
         }
 
diff --git a/src/Core/Utilities/CoreHelpers.cs b/src/Core/Utilities/CoreHelpers.cs
index c390a2acf6..a1a59a6d27 100644
--- a/src/Core/Utilities/CoreHelpers.cs
+++ b/src/Core/Utilities/CoreHelpers.cs
@@ -317,6 +317,26 @@ namespace Bit.Core.Utilities
                 !normalizedSetting.Equals("replace");
         }
 
+        public static string Base64EncodeString(string input)
+        {
+            return Convert.ToBase64String(Encoding.UTF8.GetBytes(input));
+        }
+
+        public static string Base64DecodeString(string input)
+        {
+            return Encoding.UTF8.GetString(Convert.FromBase64String(input));
+        }
+
+        public static string Base64UrlEncodeString(string input)
+        {
+            return Base64UrlEncode(Encoding.UTF8.GetBytes(input));
+        }
+
+        public static string Base64UrlDecodeString(string input)
+        {
+            return Encoding.UTF8.GetString(Base64UrlDecode(input));
+        }
+
         public static string Base64UrlEncode(byte[] input)
         {
             var output = Convert.ToBase64String(input)