OwlCyberSecurity - MANAGER

Edit File: ZIP spec.txt

Here are the notes I made while working through the ZIP file specification. For each file: local file header signature 4 bytes (0x04034b50) version needed to extract 2 bytes general purpose bit flag 2 bytes compression method 2 bytes last mod file time 2 bytes last mod file date 2 bytes crc-32 4 bytes compressed size 4 bytes uncompressed size 4 bytes file name length 2 bytes extra field length 2 bytes |sig |v |g |c |t |d |crc |csz |usz |n |x | PK.. ## 00 00 ?? ?? xxxx ???? ???? ?? 00 <file name><file data> Central directory: central file header signature 4 bytes (0x02014b50) version made by 2 bytes version needed to extract 2 bytes * general purpose bit flag 2 bytes * compression method 2 bytes * last mod file time 2 bytes * last mod file date 2 bytes * crc-32 4 bytes * compressed size 4 bytes * uncompressed size 4 bytes * file name length 2 bytes * extra field length 2 bytes * file comment length 2 bytes disk number start 2 bytes internal file attributes 2 bytes external file attributes 4 bytes relative offset of local header 4 bytes file name (variable size) extra field (variable size) file comment (variable size) |sig |vm|vx|g |c |d |t |crc |csz |usz |n |x |cm|dn|ia|xa |roff| PK.. ## ## 00 00 ?? ?? xxxx ???? ???? ?? 00 00 00 00 xxxx ???? End of central directory: end of central dir signature 4 bytes (0x06054b50) number of this disk 2 bytes number of the disk with the start of the central directory 2 bytes total number of entries in the central directory on this disk 2 bytes total number of entries in the central directory 2 bytes size of the central directory 4 bytes offset of start of central directory with respect to the starting disk number 4 bytes .ZIP file comment length 2 bytes .ZIP file comment (variable size) |sig |n1|n2|e |ne|size|off |cm| PK.. 00 00 ?? ?? ???? ???? 00