Public bug reported:
The crc32 polynomial needs to be documented in the man page. There are
multiple CRC polynomials that are defined in the community for 32-bit
calculations. It is my understanding that the polynomial is the ANSI
X3.66 CRC-32 or 0x104C11DB7. Another deficiency in the documentation is
the initial value of the CRC and the Endean-ness of the binary data.
Changing this library function will be next to impossible; however,
documentation of these items will enable us to correlate results on
other platforms.
Other unexplainable results:
1) Providing a 4 byte binary file with all zeros reports a value of "2144df1c".
This implies an initial value of 0x2144df1c.
2) Providing a 4 byte binary file with the value of 0x1c, 0xdf, 0x44, 0x21
reports a value of "6522df69".
3) Providing a 4 byte binary file with the value of 0x21, 0x44, 0xdf, 0x1c
reports a value of "5cf8b7c4".
Since neither #2 or #3 cause crc32 to report a value of "00000000", the
CRC calculator inside this utility is inconsistent with all of the CRC
algorithms I know of.
Release: Ubuntu 14.04.3 LTS Release: 14.04
libarchive-zip-perl:
Installed: 1.30-7
Candidate: 1.30-7
Version table:
*** 1.30-7 0
500 http://us.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
100 /var/lib/dpkg/status
ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: libarchive-zip-perl 1.30-7
ProcVersionSignature: Ubuntu 3.13.0-32.57-generic 3.13.11.4
Uname: Linux 3.13.0-32-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.16
Architecture: amd64
Date: Mon Nov 23 21:08:00 2015
InstallationDate: Installed on 2015-01-23 (305 days ago)
InstallationMedia: Ubuntu-Server 14.04.1 LTS "Trusty Tahr" - Release amd64
(20140722.3)
PackageArchitecture: all
ProcEnviron:
TERM=xterm
PATH=(custom, no user)
XDG_RUNTIME_DIR=<set>
LANG=en_US.UTF-8
SHELL=/usr/bin/tcsh
SourcePackage: libarchive-zip-perl
UpgradeStatus: No upgrade log present (probably fresh install)
** Affects: libarchive-zip-perl (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug trusty
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https://bugs.launchpad.net/bugs/1519207
Title:
crc32 polynomial documentation
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