So what happens when you try to extract a unencrypted 7z archive using
the internal decoder? Does that work?
On 9/14/2016 8:10 AM, Hoyer-Reuther, Christian wrote:
Hello,
our mailserver run amavisd-new-2.10.1 on Debian Jessie. Regarding encrypted
archives I configured $undecipherable_subject_tag = '+++Virus scan failed+++ '
so the recipient is notified that the archive could not be scanned.
But when 7z or 7za is used as decoder of an encrypted archive then the subject
is not modified.
According to the release notes this problem seems to be fixed in amavisd-new-2.11.0
("updated decoder for 7z archives to improve handling of encrypted content; based on
a patch by Markus Benning").
I don't know if 2.11.0 will be available on Jessie (or at least the fix for
7z), but for the moment I use the internal decoder for zip files as a
workaround. Then it works and the subject is modified.
I would like to know if there are any drawbacks when I use the internal decoder
instead of 7z for zip files.
Regards,
Christian
A few details follow:
Debian Jessie package versions:
ii amavisd-new1:2.10.1-2~deb8u1 all
ii p7zip-full 9.20.1~dfsg.1-4.1+deb8u2amd64
Test with 7z:
amavis[6356]: (06356-01) (!!)collect_results from [6416] (/usr/bin/7z): exit 2
\n7-Zip [64] 9.20 Copyright (c) 1999-2010 Igor Pavlov 2010-11-18\np7zip
Version 9.20 (locale=C,Utf16=off,
HugeFiles=on,8 CPUs)\n\nProcessing archive:
/var/lib/amavis/tmp/amavis-20160914T130733-06356-PkD36RYR/parts/p002\n\nExtracting
eicar.txt\nEnter password (will not be echoed) : CRC Failed in encrypted
file. Wrong password?\n\nSub items Errors: 1\n\n
Test with 7za:
amavis[6566]: (06566-01) (!!)collect_results from [6610] (/usr/bin/7za): exit 2
\n7-Zip (A) [64] 9.20 Copyright (c) 1999-2010 Igor Pavlov 2010-11-18\np7zip
Version 9.20 (locale=C,
Utf16=off,HugeFiles=on,8 CPUs)\n\nProcessing archive:
/var/lib/amavis/tmp/amavis-20160914T131036-06566-OSv3L3u_/parts/p002\n\nExtracting
eicar.txt\nEnter password (will not be echoed) : CRC Failed in
encrypted file. Wrong password?\n\nSub items Errors: 1\n\n
Test with internal decoder:
amavis[6804]: (06804-01) do_unzip: p002, 1 members are encrypted, none
extracted, archive retained
decoders and subject tag settings in /etc/amavis/conf.d/50-user:
$gzip = 'gzip';
$bzip2 = 'bzip2';
$lzop = 'lzop';
$rpm2cpio = ['rpm2cpio.pl','rpm2cpio'];
$cabextract = ['7z', 'cabextract'];
$uncompress = ['uncompress', 'gzip -d', 'zcat'];
$unfreeze = ['unfreeze', 'freeze -d', 'melt', 'fcat'];
$arc= ['nomarch', 'arc'];
$unarj = ['arj', 'unarj'];
$unrar = ['rar', 'unrar'];
$zoo= 'zoo';
$lha= 'lha';
$pax= 'pax';
$cpio = 'cpio';
$ar = 'ar';
$ripole = 'ripole';
$dspam = 'dspam';
unshift(@decoders,
# ['zip', \&Amavis::Unpackers::do_7zip, ['7z','7za'] ],
['zip', \&Amavis::Unpackers::do_unzip],
);
$undecipherable_subject_tag = '+++Virus scan failed+++ ';
decoders log at amavis startup:
amavis[6803]: Internal decoder for .zip
amavis[6803]: Internal decoder for .mail
amavis[6803]: No ext program for .F, tried: unfreeze, freeze -d, melt, fcat
amavis[6803]: Found decoder for.Zat /bin/uncompress
amavis[6803]: Found decoder for.gz at /bin/gzip -d
amavis[6803]: Internal decoder for .gz (backup, not used)
amavis[6803]: Found decoder for.bz2 at /bin/bzip2 -d
amavis[6803]: Found decoder for.xz at /usr/bin/xz -dc
amavis[6803]: Found decoder for.lzma at /usr/bin/xz -dc --format=lzma
amavis[6803]: Found decoder for.lrz at /usr/bin/lrzip -q -k -d -o -
amavis[6803]: Found decoder for.lzo at /usr/bin/lzop -d
amavis[6803]: Found decoder for.lz4 at /usr/bin/lz4c -d
amavis[6803]: Found decoder for.rpm at /usr/bin/rpm2cpio
amavis[6803]: Found decoder for.cpio at /bin/pax
amavis[6803]: Found decoder for.tar at /bin/pax
amavis[6803]: Found decoder for.deb at /usr/bin/ar
amavis[6803]: Found decoder for.rar at /usr/bin/unrar
amavis[6803]: Found decoder for.arj at /usr/bin/arj
amavis[6803]: Found decoder for.arc at /usr/bin/nomarch
amavis[6803]: Found decoder for.zoo at /usr/bin/zoo
amavis[6803]: Found decoder for.doc at /usr/bin/ripole
amavis[6803]: Found decoder for.cab at /usr/bin/7z
amavis[6803]: Internal decoder for .tnef
amavis[6803]: Found decoder for.zip at /usr/bin/7za (backup, not used)
amavis[6803]: Found decoder for.kmz at /usr/bin/7za
amavis[6803]: Internal decoder for .zip (backup, not used)
amavis[6803]: Internal decoder for .kmz (backup, not used)
amavis[6803]: Found decoder for.7z at /usr/bin/7za
amavis[6803]: Found decoder for.gz at /usr/bin/7za (backup, not used)
amavis[6803]: Found decoder for.bz2 at /usr/bin/7za (backup, not used)
amavis[6803]: Found decoder for.Zat /usr/bin/7za (backup, not used)
amavis[6803]: Found decoder for.tar at /usr/bin/7za (b
