CVE-2020-16155: CPAN::Checksums

• NAME
• SYNOPSIS
• INCOMPATIBILITY ALERT
• DESCRIPTION
  • Global Variables in package CPAN::Checksums
• PREREQUISITES
• BUGS
• AUTHOR
• COPYRIGHT & LICENSE
• SEE ALSO

NAME

CPAN::Checksums - Write a CHECKSUMS file for a directory as on CPAN

SYNOPSIS

  use CPAN::Checksums qw(updatedir);
  my $success = updatedir($directory, $root);

INCOMPATIBILITY ALERT

Since version 1.0 the generation of the attribute shortname is turned off by default. It was too slow and was not used as far as I know, and above all, it could fail on large directories. The shortname feature can still be turned on by setting the global variable $TRY_SHORTNAME to a true value.

DESCRIPTION

$success = updatedir($dir[, $root])

$dir is a directory. Updatedir() writes a CHECKSUMS file into that directory, unless a previously written CHECKSUMS file is there that is still valid. Returns 2 if a new CHECKSUMS file has been written, 1 if a valid CHECKSUMS file is already there, otherwise dies.

If $root is given, the hash entry with the key cpan_path is relative to this root directory.

Note: since version 2.0 updatedir on empty directories behaves just the same. In older versions it silently did nothing.

Global Variables in package CPAN::Checksums

$IGNORE_MATCH

If the global variable $IGNORE_MATCH is set, then all files matching this expression will be completely ignored and will not be included in the CPAN CHECKSUMS files. Per default this variable is set to

    qr{(?i-xsm:readme$)}

$CAUTION

Setting the global variable $CAUTION causes updatedir() to report changes of files in the attributes size, mtime, md5, or md5-ungz to STDERR.

$TRY_SHORTNAME

By setting the global variable $TRY_SHORTNAME to a true value, you can tell updatedir() to include an attribute shortname in the resulting hash that is 8.3-compatible. Please note, that updatedir() in this case may be slow and may even fail on large directories, because it will always only try 1000 iterations to find a name that is not yet taken and then give up.

$SIGNING_KEY

Setting the global variable $SIGNING_KEY makes the generated CHECKSUMS file to be clear-signed by the command specified in $SIGNING_PROGRAM (defaults to gpg --clearsign --default-key ), passing the signing key as an extra argument. The resulting CHECKSUMS file should look like:

    0&&<<''; # this PGP-signed message is also valid perl
    -----BEGIN PGP SIGNED MESSAGE-----
    Hash: SHA1

    # CHECKSUMS file written on ... by CPAN::Checksums (v...)
    $cksum = {
        ...
    };

    __END__
    -----BEGIN PGP SIGNATURE-----
    ...
    -----END PGP SIGNATURE-----

note that the actual data remains intact, but two extra lines are added to make it legal for both OpenPGP and perl syntax.

$MIN_MTIME_CHECKSUMS

If the global variable $MIN_MTIME_CHECKSUMS is set, then updatedir will renew signatures on checksum files that have an older mtime than the given value.

PREREQUISITES

DirHandle, IO::File, Digest::MD5, Digest::SHA, Compress::Bzip2, Compress::Zlib, File::Spec, Data::Dumper, Data::Compare, File::Temp

BUGS

If updatedir is interrupted, it may leave a temporary file lying around. These files have the File::Temp template CHECKSUMS.XXXX and should be harvested by a cronjob.

AUTHOR

Andreas Koenig, [email protected]; GnuPG support by Autrijus Tang

COPYRIGHT & LICENSE

Copyright © 2002-2008 Andreas Koenig, Audrey Tang, Steve Peters.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO

perl(1).