http://wiki.swganh.org/index.php?action=history&feed=atom&title=SWG_Packet_FooterSWG Packet Footer - Revision history2026-04-10T23:16:25ZRevision history for this page on the wikiMediaWiki 1.26.4http://wiki.swganh.org/index.php?title=SWG_Packet_Footer&diff=2307&oldid=prevSnow at 07:30, 21 December 20062006-12-21T07:30:18Z<p></p>
<p><b>New page</b></p><div>=Packet Footers=<br />
<br />
Every packet in SWG, regardless wether it is just SOE Protocol, just an SWG Packet, or a combination of the both, has a footer.<br />
<br />
The footer's format is as follows:<br />
<pre><br />
[Compression Flag: 1 byte][CRC value:2 bytes]<br />
total of 3 bytes<br />
[CompFlag][CRC1][CRC2]<br />
</pre><br />
<br />
The checksum algorithm used is a seeded CRC32 checksum of all the data in a packet EXCEPT the crc value located in the footer<br />
(so that includes the compression flag). The CRC is calculated after the compression and then encryption are both applied.<br />
<br />
<br />
The compression used is a default level ZLIB compression applied on the data BETWEEN the SOE opcode(part of the SOE Protocol) and the footer. So far no record has been made of a compressed packet that is NOT inside the SOE Protocol. If the packet is compressed, the Compression Flag (CompFlag) is a 1. Uncompressed packets have a Compression Flag (CompFlag) of 0.</div>Snow