Add oracle delay provided by a command line arugment

Author: hckr

Program.cs

@@ -1,22 +1,32 @@
-using System.Diagnostics;
+using System.Net.Mime;
+using System.Linq;
+using System.Diagnostics;
 using System;
 using System.Text;
+using Mono.Options;
 
 namespace Padding_Oracle_Attack
 {
     class PaddingOracleAttack
     {
         private static RemoteServerMock server = new RemoteServerMock();
 
-        public static void Main()
+        public static void Main(String[] args)
         {
-            Console.WriteLine("Enter plaintext:");
+            Console.WriteLine("~~ Padding Oracle Attack Demo ~~");
+
+            HandleConfigurationArguments(args);
+
+            Console.WriteLine("Oracle response delay set to {0} ms.", server.OracleDelayMilliseconds);
+
+            Console.WriteLine("\nEnter plaintext:");
             string plaintext = Console.ReadLine();
 
             byte[] encrypted = server.Encrypt(plaintext);
             var blocks = ByteUtils.SliceIntoBlocks(encrypted);
 
             Console.WriteLine("\nCiphertext blocks (base64):\n{0}", String.Join("\n", blocks.ConvertAll(block => Convert.ToBase64String(block))));
+
             Console.WriteLine("\nPadding oracle attack results:");
             Console.WriteLine("(first block cannot be decrypted)");
 
@@ -36,12 +46,39 @@ public static void Main()
             var decodedBlocksCount = blocks.Count - 1;
             Console.WriteLine("\nDecoded {0} blocks.", decodedBlocksCount);
 
-            if (decodedBlocksCount > 0) {
+            if (decodedBlocksCount > 0)
+            {
                 var timeElapsed = stopwatch.Elapsed;
-                Console.WriteLine("Time elapsed: {0}, avg {1:0.0} ms per block", timeElapsed.ToString(), timeElapsed.Divide(decodedBlocksCount).TotalMilliseconds);
+                Console.WriteLine("Time elapsed: {0}, avg {1:0.000} s per block", timeElapsed.ToString(), timeElapsed.Divide(decodedBlocksCount).TotalMilliseconds / 1000);
             }
         }
 
+        private static void HandleConfigurationArguments(String[] args)
+        {
+            OptionSet arguments = new OptionSet();
+            arguments.Add("d|delay=", "oracle delay in milliseconds for each padding request", (uint d) => server.OracleDelayMilliseconds = d);
+            arguments.Add("h|help", "displays this message", _ => {
+                arguments.WriteOptionDescriptions(Console.Out);
+                Environment.Exit(0);
+            });
+
+            try
+            {
+                var rest = arguments.Parse(args);
+                if (rest.Count == 0) {
+                    return;
+                }
+                Console.WriteLine("Unrecognized arguments: {0}", String.Join(",", rest));
+            }
+            catch (OptionException e)
+            {
+                Console.WriteLine(e.Message);
+            }
+
+            arguments.WriteOptionDescriptions(Console.Out);
+            Environment.Exit(1);
+        }
+
         private static string DecryptBlock(byte[] block, byte[] previousBlock)
         {
             byte[] decrypted = new byte[block.Length];

RemoteServerMock.cs

@@ -1,3 +1,4 @@
+using System.Threading;
 using System.IO;
 using System.Security.Cryptography;
 
@@ -6,6 +7,7 @@ namespace Padding_Oracle_Attack
     class RemoteServerMock
     {
         private Aes aesAlg = Aes.Create();
+        public uint OracleDelayMilliseconds { get; set; } = 0;
 
         public RemoteServerMock()
         {
@@ -37,6 +39,11 @@ public byte[] Encrypt(string plaintext)
 
         public bool IsPaddingCorrect(byte[] ciphertext)
         {
+            if (OracleDelayMilliseconds > 0)
+            {
+                Thread.Sleep((int)OracleDelayMilliseconds);
+            }
+
             try
             {
                 ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);

padding-oracle-attack.csproj

@@ -5,4 +5,8 @@
     <TargetFramework>netcoreapp2.0</TargetFramework>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="Mono.Options" Version="5.3.0.1" />
+  </ItemGroup>
+
 </Project>