dovecot - Dec 2013 - Possible pigeonhole dealing with negative numerical values

Using dovecot 2.2.9 and pigeonhole 0.4.2

The system is a Xen VM running Arch Linux x86_64, presently up to date,
on an XFS filesystem in an LVM2 partition. After recently updating my
mail server, I found that a sieve rule I had which would check
X-Spam-Score for a value over a certain number, in my case 2.5.    In my
most recent update, negative values would trip the rule.

Here's the rule in question:

# rule:[Spam Filter Subject]
if anyof (header :contains "Subject" "[SPAM]", header :value
"gt"
:comparator "i;as
cii-numeric" "X-Spam-Score" "2.5")
{
    fileinto "Spam Box";
    stop;
}


I have a successful work-around by checking the numerical value and also
insuring that the header doesn't contain a '-', and things work as
they
should.    Possible the bug could be in my Sieve interface, which is a
RoundCube plugin.   Otherwise things are working great.

If there's anything I can add, please let me know.   Thanks!

-Sam


dovecot -n output:

# 2.2.9: /etc/dovecot/dovecot.conf
# OS: Linux 3.12.4-1-ARCH x86_64  xfs
auth_cache_size = 512 k
auth_cache_ttl = 10 mins
auth_mechanisms = plain login
auth_verbose = yes
default_internal_user = mailstore
first_valid_gid = 50
first_valid_uid = 50
hostname = tacomatelematics.com
last_valid_gid = 50
last_valid_uid = 50
lda_mailbox_autocreate = yes
mail_gid = 50
mail_location = maildir:/var/spool/mail/%d/%n/Maildir/
mail_privileged_group = postfix
mail_uid = 50
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope
encoded-character vacation subaddress comparator-i;ascii-numeric
relational regex imap4flags copy include variables body enotify
environment mailbox date ihave
namespace {
  inbox = yes
  location   prefix   separator = .
  type = private
}
passdb {
  args = /etc/dovecot/dovecot-sql.conf.ext
  driver = sql
}
plugin {
  sieve = ~/.dovecot.sieve
  sieve_dir = ~/sieve
}
postmaster_address = postmaster at tacomatelematics.com
protocols = imap pop3 lmtp sieve
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0666
    user = postfix
  }
  unix_listener auth-master {
    group = mailstore
    mode = 01130
    user = mailstore
  }
  unix_listener auth-userdb {
    group = mailstore
    mode = 0600
    user = mailstore
  }
}
service managesieve-login {
  inet_listener sieve {
    port = 4190
  }
  inet_listener sieve_deprecated {
    port = 2000
  }
}
ssl_cert = </etc/certificate.pem
ssl_key = </etc/certificate.pem
userdb {
  args = /etc/dovecot/dovecot-sql.conf.ext
  driver = sql
}
protocol lmtp {
  mail_plugins = " sieve"
}
protocol lda {
  mail_plugins = " sieve"
}

On 12/14/2013 7:05 PM, Sam Mulvey wrote:
> Using dovecot 2.2.9 and pigeonhole 0.4.2
>
> The system is a Xen VM running Arch Linux x86_64, presently up to date,
> on an XFS filesystem in an LVM2 partition. After recently updating my
> mail server, I found that a sieve rule I had which would check
> X-Spam-Score for a value over a certain number, in my case 2.5.    In my
> most recent update, negative values would trip the rule.
>
> Here's the rule in question:
>
> # rule:[Spam Filter Subject]
> if anyof (header :contains "Subject" "[SPAM]", header
:value "gt"
> :comparator "i;as
> cii-numeric" "X-Spam-Score" "2.5")
> {
>     fileinto "Spam Box";
>     stop;
> }

http://tools.ietf.org/html/rfc5231#section-3 :

`Note: the "i;ascii-numeric"  comparator does not support negative
numbers.`
> I have a successful work-around by checking the numerical value and also
> insuring that the header doesn't contain a '-', and things work
as they
> should.    Possible the bug could be in my Sieve interface, which is a
> RoundCube plugin.   Otherwise things are working great.
>
> If there's anything I can add, please let me know.   Thanks!
Checking for a minus is a good workaround.

However, there is also a special set of nice Sieve extensions for the
purpose of checking spam score: http://tools.ietf.org/html/rfc5235 . It
requires some configuration at the server
(http://wiki2.dovecot.org/Pigeonhole/Sieve/Extensions/SpamtestVirustest), so
it may not always be available. Of course, Roundcube also needs to
support it for it to be useful, but I am not sure whether it can
normally use those extensions. A quick peek at the sources of the
managesieve plugin shows that it probably doesn't support the spamtest
extension:

https://github.com/roundcube/roundcubemail/blob/master/plugins/managesieve/lib/Roundcube/rcube_sieve_script.php#L29

I also took a quick peek at the source code of JohnDoh's sieverules
plugin for RoundCube, and it looks like that one does have support for
it. Note that that is a different (more feature-rich) Sieve plugin than
the managesieve plugin included in the RoundCube distribution itself.

Regards,

Stephan.