Common Data Security Architecture (CDSA) White Paper

Appendix G 125
ZIP format
G ZIP format
The credential file used to ensure data integrity is a ZIP-formatted file, whose format is
provided in this Appendix. Format information was downloaded from
http://www.goice.co.jp/member/mo/formats/zip.html.
Byte order: Little-endian
Overall zipfile format:
[Local file header + Compressed data [+ Extended local header]?]*
[Central directory]*
[End of central directory record]
Local file header:
Offset Length Contents
0 4 bytes Local file header signature (0x04034b50)
4 2 bytes Version needed to extract
6 2 bytes General purpose bit flag
8 2 bytes Compression method
10 2 bytes Last mod file time
12 2 bytes Last mod file date
14 4 bytes CRC-32
18 4 bytes Compressed size (n)
22 4 bytes Uncompressed size
26 2 bytes Filename length (f)
28 2 bytes Extra field length (e)
(f)bytes Filename
(e)bytes Extra field
(n)bytes Compressed data
Extended local header:
Offset Length Contents
0 4 bytes Extended Local file header signature (0x08074b50)