[perl #60246] broken regex behavior for strings produced by decrypt from Crypt::Rijndael

# New Ticket Created by  vvv@vsu.ru 
# Please include the string:  [perl #60246]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=60246 >



This is a bug report for perl from vvv@vsu.ru,
generated with the help of perlbug 1.36 running under perl 5.10.0.


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[Please enter your report here]

in the below test file, the string $plain is produced by the decrypt method
of Crypt::Rijndael, and $plain is equal to "This is a test\002\002",
but nevertheless attempting to strip the trailing padding with
s/\002+$//; does not work, and also if i would use $plain =~ m/(.)$/;
perl would not set $1 to \002 but will leave it undefined.
so the string $plain has some "strange" representation inside the perl.

it may be caused by Crypt::Rijndael, but in any case it looks like perl's core
behavior is broken, if such things are possible.

#############################################################################
#!/usr/bin/perl

use strict;
use Crypt::Rijndael;

my $encrypted = pack("H*","89bc70c0c151354857d0fe5d2976fc36");
my $key = pack("H*","430b26a3d7102f725ef604373651c6f0");
my $cipher = Crypt::Rijndael->new($key, Crypt::Rijndael::MODE_CBC());
my $plain = $cipher->decrypt($encrypted);
die if $plain ne "This is a test\002\002";
# so $plain ends with \002\002 indeed
print "plain: ".unpack("H*",$plain)."\n";
$plain =~ s/\002+$//;
# the above should have stripped two trailing \002 characters but it did not:
print "plain: ".unpack("H*",$plain)."\n";
#############################################################################

[Please do not change anything below this line]
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---
Flags:
    category=library
    severity=high
---
Site configuration information for perl 5.10.0:

Configured by Debian Project at Tue Sep 30 16:11:07 UTC 2008.

Summary of my perl5 (revision 5 version 10 subversion 0) configuration:
  Platform:
    osname=linux, osvers=2.6.26.1, archname=i486-linux-gnu-thread-multi
    uname='linux ninsei 2.6.26.1 #1 smp preempt sun aug 3 22:34:07 pdt 2008 i686 gnulinux '
    config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -Dcccdlflags=-fPIC -Darchname=i486-linux-gnu -Dprefix=/usr -Dprivlib=/usr/share/perl/5.10 -Darchlib=/usr/lib/perl/5.10 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.10.0 -Dsitearch=/usr/local/lib/perl/5.10.0 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Dsiteman3dir=/usr/local/man/man3 -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Ud_ualarm -Uusesfio -Uusenm -DDEBUGGING=-g -Doptimize=-O2 -Duseshrplib -Dlibperl=libperl.so.5.10.0 -Dd_dosuid -des'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=define, usemultiplicity=define
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=undef, use64bitall=undef, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2 -g',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fno-strict-aliasing -pipe -I/usr/local/include'
    ccversion='', gccversion='4.3.2', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=4, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib /usr/lib64
    libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt
    perllibs=-ldl -lm -lpthread -lc -lcrypt
    libc=/lib/libc-2.7.so, so=so, useshrplib=true, libperl=libperl.so.5.10.0
    gnulibc_version='2.7'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -O2 -g -L/usr/local/lib'

Locally applied patches:
    

---
@INC for perl 5.10.0:
    /etc/perl
    /usr/local/lib/perl/5.10.0
    /usr/local/share/perl/5.10.0
    /usr/lib/perl5
    /usr/share/perl5
    /usr/lib/perl/5.10
    /usr/share/perl/5.10
    /usr/local/lib/site_perl
    .

---
Environment for perl 5.10.0:
    HOME=/home/vvv
    LANG=en_US.UTF-8
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/home/vvv/bin:/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/games
    PERL_BADLANG (unset)
    SHELL=/bin/bash

• [perl #60246] broken regex behavior for strings produced by decrypt from Crypt::Rijndael by perlbug-followup
• Re: [perl #60246] broken regex behavior for strings produced by decrypt from Crypt::Rijndael by Nicholas Clark