Refactor multiple paddings support and other

Author: hckr

PaddingOracleDecryptor.cs

@@ -1,7 +1,5 @@
 using System;
 using System.Text;
-using System.Reflection;
-using System.Security.Cryptography;
 
 namespace Padding_Oracle_Attack
 {
@@ -13,13 +11,9 @@ class PaddingOracleDecryptor
         public PaddingOracleDecryptor(RemoteServerMock oracle)
         {
             this.oracle = oracle;
-
-            PaddingMode paddingMode = oracle.Padding;
-            // TODO: ugly, but works!
-            paddingValueProvider = (int pos, int paddingLength, int blockLength) => (byte)(typeof(PaddingValueProviders).GetMethod(Enum.GetName(typeof(PaddingMode), paddingMode)).Invoke(null, new object[] { pos, paddingLength, blockLength }));
+            paddingValueProvider = PaddingValueProviders.GetFromMode(oracle.Padding);
         }
 
-
         public string DecryptBlock(byte[] block, byte[] previousBlock)
         {
             byte[] decrypted = new byte[block.Length];

PaddingValueProviders.cs

@@ -1,9 +1,22 @@
+using System;
+using System.Security.Cryptography;
+
 namespace Padding_Oracle_Attack
 {
     public delegate byte PaddingValueProvider(int pos, int paddingLength, int blockLength);
 
     class PaddingValueProviders
     {
+        public static PaddingValueProvider GetFromMode(PaddingMode paddingMode) {
+            switch (paddingMode) {
+                case PaddingMode.PKCS7:
+                    return PKCS7;
+                case PaddingMode.ANSIX923:
+                    return ANSIX923;
+            }
+            throw new NotImplementedException(Enum.GetName(typeof(PaddingMode), paddingMode) + " is not supported.");
+        }
+
         public static byte PKCS7(int pos, int paddingLength, int blockLength)
         {
             return (byte)paddingLength;

Program.cs

@@ -1,16 +1,15 @@
-using System.Security.Cryptography;
-using System.Net.Mime;
-using System.Linq;
+using System;
 using System.Diagnostics;
-using System;
-using System.Text;
+using System.Security.Cryptography;
 using Mono.Options;
 
 namespace Padding_Oracle_Attack
 {
     class PaddingOracleAttack
     {
-        private static RemoteServerMock server = new RemoteServerMock(PaddingMode.PKCS7);
+        // change the padding used by the oracle below (decryptor uses the same as the server/oracle)
+        private const PaddingMode paddingMode = PaddingMode.PKCS7;
+        private static RemoteServerMock server = new RemoteServerMock(paddingMode);
         private static PaddingOracleDecryptor decryptor = new PaddingOracleDecryptor(server);
 
         public static void Main(String[] args)

RemoteServerMock.cs

@@ -1,5 +1,5 @@
-using System.Threading;
 using System.IO;
+using System.Threading;
 using System.Security.Cryptography;
 
 namespace Padding_Oracle_Attack