We have released the new stable version of Rspamd today. It includes couple of important fixes and improvements. Here is the list of the most important ones.

Base64 decoding fix

We have found and resolved a serious flaw in the current base64 decoder in Rspamd. It could lead to the corrupted output in case if decoder finds out some non base64 characters, for example, spaces or newlines. This bug could affect statistics, fuzzy checks and couple of other fields in Rspamd. Hence, we recommend to update to 1.5.3 as soon as possible.

Redis history

This release includes experimental feature that allows to save history in Redis. There is the initial WebUI support of this feature, however, it is not now enabled by default. In future, we plan to enable it and to enchance history with a set of new options:

• displaying of sender and recipient in history table;
• support of symbols options;
• clustered history;
• dynamic load of history rows;
• compressed history;

All these features are implemented for the backend part (namely, Rspamd controller) but it still requires some major rework of the web interface itself, therefore, this work is postponed till the next version.

Dkim plugin improvements

DKIM signing module now supports the type of private key passed to the module: in addition to PEM format stored in a file, DKIM signing now supports raw keys, base64 encoded keys and PEM keys from raw strings.

DKIM signing now also supports maps for selecting domains to sign.

Other plugins improvements

• greylist plugin now supports excluding low-scoring messages from greylisting
• whitelist plugin can now load list of maps
• ratelimit plugin now excludes greylisted messages
• metadata exporter uses rule-specific settings for emails
• metadata exporter can now use non-ASCII characters in reports

Rules update

Here is the list of rules that are fixed or reworked:

• URI_COUNT_ODD rule now excludes visual URLs which reduces its FP rate
• RCPT_COUNT* and HAS_X_PRIO* rules are reworked to the normal Rspamd symbols conventions
• misc.lua has been split to multiple modules that share the common rules

Other bugs fixes

• imported important fixes for ac-trie module
• fixed local networks proxying
• fixed memory corruption in periodic tasks during worker cleanup phase
• fixed subject rewriting
• improved zstd lua API to avoid extra reallocation