Rspamd 1.3.3 has been released

2016-08-15 00:00:00 +0200

The new stable version of Rspamd is available: 1.3.3. This release includes a couple of critical bugs fixes and important improvements. We recommend to update Rspamd to version 1.3.3 as soon as possible due to a serious error in fuzzy hashes processing.

Important fuzzy hashes incompatibility

There was a serious bug in fuzzy check plugin when using transport encryption and the default fuzzy key. Since encryption is enabled in the default configuration, all users should consider updating their Rspamd packages. Another important consequence of this bug is that the private fuzzy storages should be relearned because of a wrong key used for hashing. To summarize, here is a list of issues for different types of fuzzy storages:

  1. For private fuzzy storages that are used without encryption_key nothing has changed and everything should work as desired
  2. For storages with explicit fuzzy_key everything should work as desired with the exception of attachments hashes: they no longer use custom fuzzy_key for performance and architecture reasons. So it is recommended to relearn such a storage after upgrading to 1.3.3
  3. For storages without explicit fuzzy_key but with encryption_key the recommended action is to upgrade to 1.3.3 and relearn a storage since all old hashes won’t be recognized (there won’t be any false positive hits however).

Rspamd.com fuzzy storage has changed hashing algorithm

Users of rspamd.com storage should either use the provided default configuration for fuzzy_check plugin or update their custom configuration to include the following line in the rule for rspamd.com storage:

rule "rspamd.com" {
  algorithm = "mumhash";
  # The rest of the configuration
}

The default rule provided by Rspamd distribution is now the following:

rule "rspamd.com" {
  algorithm = "mumhash";
  servers = "rspamd.com:11335";
  encryption_key = "icy63itbhhni8bq15ntp5n5symuixf73s1kpjh6skaq4e7nx5fiy";
  symbol = "FUZZY_UNKNOWN";
  mime_types = ["application/*"];
  max_score = 20.0;
  read_only = yes;
  skip_unknown = yes;
  fuzzy_map = {
    FUZZY_DENIED {
      max_score = 20.0;
      flag = 1;
    }
    FUZZY_PROB {
      max_score = 10.0;
      flag = 2;
    }
    FUZZY_WHITE {
      max_score = 2.0;
      flag = 3;
    }
  }
}

Failure to update hashing algorithm will cause Rspamd not to find any hits in the rspamd.com storage.

Support for Redis maps in the Multimap plugin

There is now Redis support in the Multimap plugin. With this feature you can create maps that can be easily scaled and frequently modified. For example, you could use it for temporary records that work as DNS blacklists but using Redis storage.

Hyperscan cache important fix

This version contains an important fix for Hyperscan caching inconsistency. After rules change, there were no checks against sanity of regexp ids stored in the cache. In turn, that caused random regexps misdetections and false positive detections. In version 1.3.3 Rspamd checks every single ID using checksum and recompiles the whole cached file when a checksum is invalid.

SARBL URL black list support has been added to the default configuration

Rspamd now will check URLs using SARBL list to detect bad or phishing domains in messages.

Lua API improvements

There are number of improvements in Lua API shipped with Rspamd:

  • util.get_tld function has been fixed to find the longest possible TLD
  • rspamd_url now allows initialization of the library and provides a simpler API to parse URLs in strings
  • rspamd_cryptobox now provides a one step hashing API
  • util.strequal_caseless function now works as intended
  • rspamd_redis now returns nil for data when Redis returns NIL (e.g. when a key is not found)
  • rspamd_http now always performs DNS request even when maximum number of DNS requests for a message has been reached

Prefilters and postfilters registered in Rspamd are now executed in order defined by their priority:

  • Prefilters with higher priority are executed first
  • Postfilters with higher priority are executed last

Rspamd 1.3.2 has been released

2016-08-08 00:00:00 +0200

The next stable version of Rspamd, 1.3.2, is now available. It contains many improvements, bug fixes and another integration method: Communigate Pro helper. Here are the main improvements added in this version:

Important bug fixes

There was a bug introduced in 1.3.0 related to multiple value header processing which broke, for instance, the processing of multiple SMTP recipients. This issue has been fixed in 1.3.2.

Attributes in HTML tags are now HTML decoded to avoid polluting other elements.

The last element in DMARC records is now correctly parsed.

Hfilter module has been reworked to reduce false positive hits rate for hostnames and SMTP helo values.

SPF plugin features

Rspamd now recognizes DNS failures when resolving SPF records and abstains from caching failed lookups. There is now a new symbol R_SPF_DNSFAIL that is inserted when there was a DNS error during resolving of a SPF record. Furthermore, Rspamd will not insert R_SPF_DENY if there was an error looking up records required by policy.

Better HTML support

There are a couple of features and important bugs fixes for HTML parser introduced in Rspamd 1.3.2. There is new HTML block elements parser that can deal with colors in HTML documents and, in particular, with named colors. Secondly, parsed HTML tags now contain the length of the content enclosed within the tag. And finally, the Lua API is improved with a new foreach_tag method that allows traversing across particular HTML tags examining their content. The existing HTML related rules are updated accordingly to deal with HTML spam better using the new API.

Improved settings matches for authorized users

It is now possible to match any authorized user when applying user settings. It might be useful for applying different settings to authenticated users:

outbound {
  priority = high;
  id = "outbound";
  authenticated = true;

  apply {
    groups_disabled = ["hfilter", "spf", "dkim", "rbl"];
  }
}

Redis integration fix

Rspamd no longer uses the KEYS pattern* command for getting statistics. It was found that this command literally kills Redis performance on large data sets. This mechanism has been reworked to avoid KEYS command.

DKIM support improvements

DKIM signing has been fixed with additional tests added. rspamc utility can now use a DKIM signature header passed by Rspamd to sign email in --mime mode. DKIM header folding issues have been found and fixed in Rspamd 1.3.2.

URL detection fixes

Rspamd now tries to search for a longest possible suffix when matching TLD parts to distinguish between common suffixes of different length, for example .net and .in.net.

Rspamd 1.3.1 has been released

2016-08-01 00:00:00 +0200

We have released new updates for Rspamd and Rmilter: 1.3.1 and 1.9.1 accordingly. There are a couple of important bugfixes and some useful new features in these releases.

Systemd activation has been removed from Rspamd and Rmilter

Over the recent years, we have experienced constant issues reported by users about Systemd socket activation. This feature seems to be completely broken in systems with both IPv4/IPv6 enabled. Moreover, it seems to be harmful as Rspamd setup time is quite significant whilst socket activation is mostly intended for interactive on-demand daemons. Socket activation has been added under the pressure of Debian packaging rules, though Rspamd is completely rotten in Debian official repos and we strongly discourage Debian users from using the official Debian packages. While we are still looking for a new Debian maintainer for Rspamd, I can declare that there will be no sockets activation enabled by default in Rspamd nor Rmilter.

The switch to standalone mode should be transparent for users. The only significant difference is use of rspamd.service instead of rspamd.socket in service management commands. In some cases you might need to restart Rmilter after upgrade (for example, in Debian Jessie):

systemctl restart rmilter.service

Rmilter crash on BSD systems

There was a bug that was caused by use of pthread_specific variables. Unfortunately, libmilter is poorly designed and can destroy or move certain threads which causes horrific errors. Linux is somehow not affected, however, there is still use-after-free bug with this approach. In Rmilter 1.9.1, this issue has been fixed.

New multimap features in Rspamd

The multimap module has been significantly updated in Rspamd 1.3.1. It now supports maps that are checked conditionally depending on combinations of other symbols. There is now also support for multiple symbols and scores per map. A new hostname map type has been added to support matching of hostnames. Many new tests have been written to cover multimap functions and to provide resistance against regressions.

Greylisting fixes in Rspamd

There are a couple of fixes in the greylisting module, including authenticated users whitelisting, general logic fixes and restoration of selective greylisting.

Critical issue with Catena password scheme

There was a regression in 1.3 that prevented Catena password encryption scheme from being correctly read by the controller. It has been fixed in 1.3.1, so Catena passwords (those with $2$ prefix) could be used again.

Critical fix for Hyperscan cache

There was a race condition when a worker that writes Hyperscan file was killed in the middle of this process. Afterwards, a cache file was left in an inconsistent state which wasn’t detected or corrected on subsequent Rspamd runs. That caused multiple issues with regular expressions processing, including false and failed matches on arbitrary texts. Since 1.3.1, Rspamd strictly ensures that a Hyperscan cache file has been correctly written to the filesystem.

Message size limit in Rspamd

We now limit the incoming size of a message to prevent crashes on insane input. By default, this limit is set to 50Mb, however it can be changed by max_message setting in the options section:

# local.d/options.inc
max_message = 100Mb;

Rspamd configuration files includes logic

From this version, the behaviour of local.d and override.d is consistent with their description: values in local.d add values to the existing configuration overwriting the same keys, and values from override.d overwrites the whole sections. For example, if we have the original configuration that looks like this:

# orig.conf
rule "something" {
  key1 = value1;
  key2 = {
    subkey1 = "subvalue1";
  }
}
rule "other" {
  key3 = value3;
}

and some local.d/orig.conf that looks like this:

# local.d/orig.conf
rule "something" {
  key1 = other_value; # overwrite "value1"
  key2 = {
    subkey2 = "subvalue2"; # append new value
  }
}
rule "local" { # add new rule
  key_local = "value_local";
}

then we will have the following merged configuration:

# config with local.d/orig.conf
rule "something" {
  key1 = other_value; # from local
  key2 = {
    subkey1 = "subvalue1";
    subkey2 = "subvalue2"; # from local
  }
}
rule "other" {
  key3 = value3;
}
rule "local" { # from local
  key_local = "value_local";
}

If you have the same config but in override.d directory, then it will completely override all rules defined in the original file:

# config with override.d/orig.conf
rule "something" {
  key1 = other_value;
  key2 = {
    subkey2 = "subvalue2";
}
rule "local" {
  key_local = "value_local";
}

Other bugfixes and improvements

There are couple of other important bugfixes and improvements including a critical fix for extracting values from the top received header. The test framework has been improved with new functional tests and better integration with CircleCI.