public static void Initialize(ClientCryptData cryptData, byte[] inputK)
{
Blowfish.SetKey(inputK, cryptData.Key);
using (var md5 = MD5.Create())
Array.Copy(md5.ComputeHash(inputK), cryptData.MD5, 0x10);
Array.Copy(inputK, cryptData.K, 0x40);
}
public static bool Decrypt(byte[] data, int offset, int length, ClientCryptData cryptData = null)
{
if (length % 8 != 0)
{
throw new ArgumentOutOfRangeException(nameof(length), "The lenght must be a multiple of 8!");
}
Blowfish.Decrypt(data, offset, length);
return(VerifyChecksum(data, offset, length));
}
public static bool Decrypt(byte[] data, int offset, int length, ClientCryptData cryptData)
{
if (length % 8 != 0)
{
throw new ArgumentOutOfRangeException(nameof(length), "The lenght must be a multiple of 8!");
}
var uintData = new uint[length / 4];
Buffer.BlockCopy(data, offset, uintData, 0, length);
var x = SwitchEndianInt(BitConverter.ToUInt32(cryptData.MD5, 0));
var y = SwitchEndianInt(BitConverter.ToUInt32(cryptData.MD5, 4));
for (var i = 0; i < (length / 8); ++i)
{
//Switch endian first
var a2 = i * 2;
uintData[a2] = SwitchEndianInt(uintData[a2]);
uintData[a2 + 1] = SwitchEndianInt(uintData[a2 + 1]);
//Store new XOR
var x2 = uintData[a2];
var y2 = uintData[a2 + 1];
Blowfish.Decrypt(uintData, a2, cryptData.Key);
uintData[a2] ^= x;
uintData[a2 + 1] ^= y;
//Update XOR
x = x2;
y = y2;
//Switch endian now
uintData[a2] = SwitchEndianInt(uintData[a2]);
uintData[a2 + 1] = SwitchEndianInt(uintData[a2 + 1]);
}
Buffer.BlockCopy(uintData, 0, data, offset, length);
return(true);
}
public static void Encrypt(byte[] data, int offset, ref int length, int maxLength, ClientCryptData cryptData = null)
{
var oldLen = length;
// Make the length a multiple of 8
var rem = length % 8;
if (rem != 0)
{
length += 8 - rem;
}
if (length + 8 > maxLength)
{
throw new ArgumentOutOfRangeException(nameof(length), "The length can't exceed the maximal buffer length!");
}
// Fill up extra padding bytes
for (var i = oldLen; i < length; ++i)
{
data[offset + i] = 0xCC;
}
// Add checksum bytes to the length
length += 8;
AppendChecksum(data, offset, length);
Blowfish.Encrypt(data, offset, length);
}
public static void Encrypt(byte[] data, int offset, ref int length, int maxLength, ClientCryptData cryptData)
{
var oldLen = length;
// Make the length a multiple of 8
var rem = length % 8;
if (rem != 0)
{
length += 8 - rem;
}
if (length > maxLength)
{
throw new ArgumentOutOfRangeException(nameof(length), "The length can't exceed the maximal buffer length!");
}
// Fill up extra padding bytes
for (var i = oldLen; i < length; ++i)
{
data[offset + i] = 0xCC;
}
var uintData = new uint[length / 4];
Buffer.BlockCopy(data, offset, uintData, 0, length);
var x = SwitchEndianInt(BitConverter.ToUInt32(cryptData.MD5, 0));
var y = SwitchEndianInt(BitConverter.ToUInt32(cryptData.MD5, 4));
for (var i = 0; i < (length / 8); ++i)
{
var a2 = i * 2;
uintData[a2] = SwitchEndianInt(uintData[a2]);
uintData[a2 + 1] = SwitchEndianInt(uintData[a2 + 1]);
uintData[a2] ^= x;
uintData[a2 + 1] ^= y;
Blowfish.Encrypt(uintData, a2, cryptData.Key);
x = uintData[a2];
y = uintData[a2 + 1];
uintData[a2] = SwitchEndianInt(uintData[a2]);
uintData[a2 + 1] = SwitchEndianInt(uintData[a2 + 1]);
}
Buffer.BlockCopy(uintData, 0, data, offset, length);
}