PAK File Format

PAK File

PAK files are archives of data used by RIFT. The manifest file contains references to PAK files and entries within the manifest contain offsets within those PAK files. This allows a client to download individual files directly out of the PAK using HTTP range headers.

File format

Little endian.

Consists of a file header followed by an entry block and finally data.

Header

Bytes/Offset	Content	Comment
4 bytes	Integer	File version
4 bytes	Integer	File size in bytes
4 bytes	Integer	Size of the header in bytes
4 bytes	integer	Size of the entry block in bytes. Each entry is 60 bytes in size.

Entry block

Bytes/Offset	Content	Comment
4 bytes	Integer	Unknown
4 bytes	Integer	Unknown
4 bytes	Integer	Unknown
4 bytes	bytes	Filename hash- FNV1
4 bytes	Integer	Unknown
4 bytes	Integer	Compressed size of the entry in bytes
4 bytes	Integer	Uncompressed size of the entry in bytes
4 bytes	Integer	Unknown
4 bytes	Integer	Offset from the start of the file in bytes the data for this entry is at
24 bytes		Unknown - possibly reserved for SHA hash?

Data

The data is either compressed or uncompressed, you can determine if it is compressed by comparing the compressed and uncompressed size of the entry, if they are equal the data is uncompressed.

If compressed, LZMA2 is generally used.