C#

<br />
public byte[] SecureSerialize(byte[] key, byte[] iv)<br />
{<br />
	byte[] streamBuffer = new byte[BufferSize];<br />
<br />
	MemoryStream ms = new MemoryStream(streamBuffer);<br />
	ms.WriteByte((byte)encrypted);<br />
<br />
	RijndaelManaged rij = new RijndaelManaged();<br />
	CryptoStream cs = new CryptoStream(ms, rij.CreateEncryptor(key, iv), CryptoStreamMode.Write);<br />
<br />
	BinaryFormatter bf = new BinaryFormatter();<br />
	bf.Serialize(cs, this);<br />
<br />
	SHA1Managed hashAlg = new SHA1Managed();<br />
	byte[] hash = hashAlg.ComputeHash(streamBuffer, 0, (int)ms.Position);<br />
	bf.Serialize(ms, hash);<br />
<br />
	byte[] returnBuffer = new byte[(int)ms.Position];<br />
	Array.Copy(streamBuffer, 0, returnBuffer, 0, (int)ms.Position);<br />
<br />
	return returnBuffer;<br />
}<br />
<br />
public static UdpMessage SecureDeserialize(byte[] msg, byte[] key, byte[] iv)<br />
{<br />
	MemoryStream ms = new MemoryStream(msg);<br />
	byte enc = (byte)ms.ReadByte();<br />
<br />
	RijndaelManaged rij = new RijndaelManaged();<br />
	CryptoStream cs = new CryptoStream(ms, rij.CreateDecryptor(key, iv), CryptoStreamMode.Read);<br />
<br />
	BinaryFormatter bf = new BinaryFormatter();<br />
	UdpMessage message = (UdpMessage)bf.Deserialize(cs); //  <<<----This fails<br />
<br />
	message.encrypted = (Encryption)enc;<br />
<br />
	SHA1Managed hashAlg = new SHA1Managed();<br />
	byte[] calculatedHash = hashAlg.ComputeHash(msg, 0, (int)ms.Position);<br />
	byte[] msgHash = (byte[])bf.Deserialize(ms);<br />
	for (int i = 0 ; i < calculatedHash.Length ; i++)<br />
		if (calculatedHash[i] != msgHash[i])<br />
			throw new CryptographicException("Hash missmatch");<br />
<br />
	return message;<br />
}<br />

using System;

namespace leppie
{
  public class Hashtable
  {
    struct bucket
    {
      internal object key;
      internal object val;
    }

    private int size;
    private bucket[] buckets;
    private static readonly uint[] primes = { // i wonder where they came from :)
      11,17,23,29,37,47,59,71,89,107,131,163,197,239,293,353,431,521,631,761,919,
      1103,1327,1597,1931,2333,2801,3371,4049,4861,5839,7013,8419,10103,12143,14591,
      17519,21023,25229,30293,36353,43627,52361,62851,75431,90523, 108631, 130363,
      156437, 187751, 225307, 270371, 324449, 389357, 467237, 560689, 672827, 807403,
      968897, 1162687, 1395263, 1674319, 2009191, 2411033, 2893249, 3471899, 4166287,
      4999559, 5999471, 7199369 };

    public Hashtable()
    {
      size = 0;
      buckets = new bucket[0];
    }

    private static uint Hash(object key)
    { 
      return (uint) key.GetHashCode();
    }

    private static bool compare(object key1, object key2)
    {
      return key1.Equals(key2);
    }

    private uint GetCap()
    {
      uint i = 0, l = 0;
      for (;i < size;i++)
        l += primes[i];
      return l;
    }

    private int AddBucketSet()
    {
      bucket[] newbuckets = new bucket[GetCap() + primes[size]];
      Array.Copy(buckets, newbuckets, buckets.Length);
      buckets = newbuckets;
      return ++size;
    }

    public void Add(object key, object value)
    {
      for (uint i = 0, pos = 0, hash = Hash(key); i < size;i++)
      {
        pos += hash % primes[i];
        if (buckets[pos].key == null)
        {
          buckets[pos].key = key;
          buckets[pos].val = value;
          return;
        }
      }
      /* too small */
      AddBucketSet();

      /* just do it again */
      Add(key, value);
    }

    public bool Contains(object key)
    {
      for (uint i = 0, pos = 0, hash = Hash(key); i < size;i++)
      {
        pos += hash % primes[i];
        if (compare(buckets[pos].key,key))
          return true;
      }
      return false;
    }

    public object this[object key]
    {
      get 
      {
        for (uint i = 0, pos = 0, hash = Hash(key); i < size;i++)
        {
          pos += hash % primes[i];
          if (compare(buckets[pos].key, key))
            return buckets[pos].val;
        }
        return null;
      }
      set 
      {
        if (!Contains(key))
          Add(key, value);
        else
        {
          for (uint i = 0, pos = 0, hash = Hash(key); i < size;i++)
          {
            pos += hash % primes[i];
            if (compare(buckets[pos].key,key))
              buckets[pos].val = value;
          }
        }
      }
    }
  }
}