/// <summary>
/// Encrypt data using MapleStory's AES method
/// </summary>
/// <param name="iv">IV to use for encryption</param>
/// <param name="data">data to encrypt</param>
/// <param name="length">length of data</param>
/// <param name="key">the AES key to use</param>
/// <returns>Crypted data</returns>
public static byte[] AesCrypt(byte[] iv, byte[] data, int length, byte[] key)
{
var crypto = new AesManaged
{
KeySize = 256,
Key = key,
Mode = CipherMode.ECB // Should be OFB, but this works too
};
using (var memStream = new MemoryStream())
{
using (var cryptoStream = new CryptoStream(memStream, crypto.CreateEncryptor(), CryptoStreamMode.Write))
{
var remaining = length;
var size = 0x5B0;
var start = 0;
while (remaining > 0)
{
var myIv = MapleCrypto.MultiplyBytes(iv, 4, 4);
if (remaining < size)
{
size = remaining;
}
for (var x = start; x < start + size; x++)
{
if ((x - start) % myIv.Length == 0)
{
cryptoStream.Write(myIv, 0, myIv.Length);
var newIv = memStream.ToArray();
Array.Copy(newIv, myIv, myIv.Length);
memStream.Position = 0;
}
data[x] ^= myIv[(x - start) % myIv.Length];
}
start += size;
remaining -= size;
size = 0x5B4;
}
}
}
return(data);
}
/// <summary>
/// Encrypt data using MapleStory's AES method
/// </summary>
/// <param name="IV">IV to use for encryption</param>
/// <param name="data">data to encrypt</param>
/// <param name="length">length of data</param>
/// <param name="key">the AES key to use</param>
/// <returns>Crypted data</returns>
public static byte[] AesCrypt(byte[] IV, byte[] data, int length, byte[] key)
{
AesManaged crypto = new AesManaged
{
KeySize = 256, //in bits
Key = key,
Mode = CipherMode.ECB // Should be OFB, but this works too
};
using (MemoryStream memStream = new MemoryStream())
{
using (CryptoStream cryptoStream = new CryptoStream(memStream, crypto.CreateEncryptor(), CryptoStreamMode.Write))
{
int remaining = length;
int llength = 0x5B0;
int start = 0;
while (remaining > 0)
{
byte[] myIV = MapleCrypto.MultiplyBytes(IV, 4, 4);
if (remaining < llength)
{
llength = remaining;
}
for (int x = start; x < (start + llength); x++)
{
if ((x - start) % myIV.Length == 0)
{
cryptoStream.Write(myIV, 0, myIV.Length);
byte[] newIV = memStream.ToArray();
Array.Copy(newIV, myIV, myIV.Length);
memStream.Position = 0;
}
data[x] ^= myIV[(x - start) % myIV.Length];
}
start += llength;
remaining -= llength;
llength = 0x5B4;
}
}
}
return(data);
}