Java Decryption Algorithm SWG

gistfile1.java

public static byte[] Decrypt(byte[] pData, int len, int nCrcSeed) {
		nCrcSeed = Integer.reverseBytes(nCrcSeed);
		// System.out.println("Decrypt.  Original buffer: ");
		// printPacketData(pData);
		int offset = 0;
		int[] Data;
		byte[] byteData;
		if (pData[0] == 0) {
			len -= 4;
			offset = 2;
		} else {
			len -= 3;
			offset = 1;
		}
		int blockCount = (len) / 4;
		int byteCount = (len) % 4;
		if (byteCount < 0 || blockCount < 0) {
			return pData;
		}
		Data = new int[blockCount];
		byteData = new byte[byteCount];
		ByteArrayInputStream bIn = new ByteArrayInputStream(pData);
		DataInputStream dIn = new DataInputStream(bIn);
		byte[] header = new byte[offset];
		int iTemp = 0;
		try {
			dIn.read(header, 0, offset);
			for (int i = 0; i < blockCount; i++) {
				Data[i] = dIn.readInt();
				iTemp = Data[i]; // iTemp == encrypted data.
				Data[i] ^= nCrcSeed; // Decrypt the data.

				nCrcSeed = iTemp; // CRC seed now equals the encrypted data.
			}
			nCrcSeed = Integer.reverseBytes(nCrcSeed); // WTF? This is why I
														// prefer Java -- I SEE
														// NOWHERE WHERE IT SAYS
														// TO DO THIS IN THE
														// ORIGINAL C++
														// ALGORITHM.
			for (int i = 0; i < byteCount; i++) {
				byte originalByte = dIn.readByte();
				iTemp = (originalByte ^ nCrcSeed);
				byteData[i] = (byte) iTemp;
			}
			ByteArrayOutputStream bOut = new ByteArrayOutputStream();
			DataOutputStream dOut = new DataOutputStream(bOut);
			dOut.write(header);
			for (int i = 0; i < Data.length; i++) {
				dOut.writeInt(Data[i]);
			}
			for (int i = 0; i < byteData.length; i++) {
				dOut.writeByte(byteData[i]);
			}
			for (int i = pData.length - 2; i < pData.length; i++) {
				dOut.writeByte(pData[i]);
			}
			// System.out.println("Finished decrypt.  Packet data: " );
			byte[] toReturn = bOut.toByteArray();
			// printPacketData(toReturn);
			return toReturn;
		} catch (Exception e) {
			System.out.println("Error decrypting packet: " + e.toString());
			e.printStackTrace();
			return pData;
		}
	}