pkg-perl-maintainers team mailing list archive

["Luke A. Perkins" <public@xxxxxxxxxx>]

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

-- 
You received this bug notification because you are a member of Debian
Perl Group, which is subscribed to libarchive-zip-perl in Ubuntu.
https://bugs.launchpad.net/bugs/1519207

Title:
  crc32 polynomial documentation

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/libarchive-zip-perl/+bug/1519207/+subscriptions