Bionic Buffalo Tech Note #66: File Identification Headers
the unstructured parts of the identification information for the application, organization,
and owner
The identification magic number, header version, and header options contain the following fields:
offset
length
type
description
0
8
octet sequence
magic number or sequence; must be
a4 bc dd a0 a5 e6 44 58
8
4
unsigned integer
header format version (currently A.0.8.2, represented
as
0x01000802
)
12
4
unsigned integer
required software version to read this header
(currently the same as above)
16
4
unsigned integer
total length of identification header (including
padding for alignment; see below)
20
4
unsigned integer
header CRC or checksum correction value
24
1
unsigned integer
header CRC or checksum correction type:
0 -
none
1 -
simple checksum (total =
0xffffffff
)
2 -
CRC-32 (total =
0
)
25
7
octet sequence
option flags and values, currently unused and must be
set to zeroes
The total length of the above information is 32 octets. Integers in the header (including in the structures
below) are all stored in network (big-endian) byte order.
The fixed information for each aspect (application, organization, and owner) contains the following
fields:
offset
length
type
description
x + 0
16
octet sequence
UUID (created by
uuidgen
or by an equivalent
function)
x + 16
16
octet sequence
serial number (assigned as required when each file
must be uniquely or somewhat uniquely identified)
x + 32
4
unsigned integer
type of file (used to distinguish among several types,
when necessary)
x + 36
4
unsigned integer
number of file (used when several similar files must
be counted or labelled)
x + 40
4
unsigned integer
version number of software used to create this file
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