diff options
Diffstat (limited to 'lualib/lua_scanners/spamassassin.lua')
| -rw-r--r-- | lualib/lua_scanners/spamassassin.lua | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/lualib/lua_scanners/spamassassin.lua b/lualib/lua_scanners/spamassassin.lua new file mode 100644 index 0000000..f425924 --- /dev/null +++ b/lualib/lua_scanners/spamassassin.lua @@ -0,0 +1,213 @@ +--[[ +Copyright (c) 2022, Vsevolod Stakhov <vsevolod@rspamd.com> +Copyright (c) 2019, Carsten Rosenberg <c.rosenberg@heinlein-support.de> + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. +]]-- + +--[[[ +-- @module spamassassin +-- This module contains spamd access functions. +--]] + +local lua_util = require "lua_util" +local tcp = require "rspamd_tcp" +local upstream_list = require "rspamd_upstream_list" +local rspamd_logger = require "rspamd_logger" +local common = require "lua_scanners/common" + +local N = 'spamassassin' + +local function spamassassin_config(opts) + + local spamassassin_conf = { + N = N, + scan_mime_parts = false, + scan_text_mime = false, + scan_image_mime = false, + default_port = 783, + timeout = 15.0, + log_clean = false, + retransmits = 2, + cache_expire = 3600, -- expire redis in one hour + symbol = "SPAMD", + message = '${SCANNER}: Spamassassin bulk message found: "${VIRUS}"', + detection_category = "spam", + default_score = 1, + action = false, + extended = false, + symbol_type = 'postfilter', + dynamic_scan = true, + } + + spamassassin_conf = lua_util.override_defaults(spamassassin_conf, opts) + + if not spamassassin_conf.prefix then + spamassassin_conf.prefix = 'rs_' .. spamassassin_conf.name .. '_' + end + + if not spamassassin_conf.log_prefix then + if spamassassin_conf.name:lower() == spamassassin_conf.type:lower() then + spamassassin_conf.log_prefix = spamassassin_conf.name + else + spamassassin_conf.log_prefix = spamassassin_conf.name .. ' (' .. spamassassin_conf.type .. ')' + end + end + + if not spamassassin_conf.servers then + rspamd_logger.errx(rspamd_config, 'no servers defined') + + return nil + end + + spamassassin_conf.upstreams = upstream_list.create(rspamd_config, + spamassassin_conf.servers, + spamassassin_conf.default_port) + + if spamassassin_conf.upstreams then + lua_util.add_debug_alias('external_services', spamassassin_conf.N) + return spamassassin_conf + end + + rspamd_logger.errx(rspamd_config, 'cannot parse servers %s', + spamassassin_conf.servers) + return nil +end + +local function spamassassin_check(task, content, digest, rule) + local function spamassassin_check_uncached () + local upstream = rule.upstreams:get_upstream_round_robin() + local addr = upstream:get_addr() + local retransmits = rule.retransmits + + -- Build the spamd query + -- https://svn.apache.org/repos/asf/spamassassin/trunk/spamd/PROTOCOL + local request_data = { + "HEADERS SPAMC/1.5\r\n", + "User: root\r\n", + "Content-length: " .. #content .. "\r\n", + "\r\n", + content, + } + + local function spamassassin_callback(err, data) + + local function spamassassin_requery(error) + + -- retry with another upstream until retransmits exceeds + if retransmits > 0 then + + retransmits = retransmits - 1 + + lua_util.debugm(rule.N, task, '%s: Request Error: %s - retries left: %s', + rule.log_prefix, error, retransmits) + + -- Select a different upstream! + upstream = rule.upstreams:get_upstream_round_robin() + addr = upstream:get_addr() + + lua_util.debugm(rule.N, task, '%s: retry IP: %s:%s', + rule.log_prefix, addr, addr:get_port()) + + tcp.request({ + task = task, + host = addr:to_string(), + port = addr:get_port(), + upstream = upstream, + timeout = rule['timeout'], + data = request_data, + callback = spamassassin_callback, + }) + else + rspamd_logger.errx(task, '%s: failed to scan, maximum retransmits ' .. + 'exceed - err: %s', rule.log_prefix, error) + common.yield_result(task, rule, 'failed to scan and retransmits exceed: ' .. error, 0.0, 'fail') + end + end + + if err then + + spamassassin_requery(err) + + else + --lua_util.debugm(rule.N, task, '%s: returned result: %s', rule.log_prefix, data) + + --[[ + patterns tested against Spamassassin 3.4.6 + + X-Spam-Status: No, score=1.1 required=5.0 tests=HTML_MESSAGE,MIME_HTML_ONLY, + TVD_RCVD_SPACE_BRACKET,UNPARSEABLE_RELAY autolearn=no + autolearn_force=no version=3.4.6 + ]] -- + local header = string.gsub(tostring(data), "[\r\n]+[\t ]", " ") + --lua_util.debugm(rule.N, task, '%s: returned header: %s', rule.log_prefix, header) + + local symbols = "" + local spam_score = 0 + for s in header:gmatch("[^\r\n]+") do + if string.find(s, 'X%-Spam%-Status: %S+, score') then + local pattern_symbols = "X%-Spam%-Status: %S+, score%=([%-%d%.]+)%s.*tests%=(.*,?)(%s*%S+)%sautolearn.*" + spam_score = string.gsub(s, pattern_symbols, "%1") + symbols = string.gsub(s, pattern_symbols, "%2%3") + symbols = string.gsub(symbols, "%s", "") + end + end + + lua_util.debugm(rule.N, task, '%s: spam_score: %s, symbols: %s, int spam_score: |%s|, type spam_score: |%s|', + rule.log_prefix, spam_score, symbols, tonumber(spam_score), type(spam_score)) + + if tonumber(spam_score) > 0 and #symbols > 0 and symbols ~= "none" then + + if rule.extended == false then + common.yield_result(task, rule, symbols, spam_score) + common.save_cache(task, digest, rule, symbols, spam_score) + else + local symbols_table = lua_util.str_split(symbols, ",") + lua_util.debugm(rule.N, task, '%s: returned symbols as table: %s', rule.log_prefix, symbols_table) + + common.yield_result(task, rule, symbols_table, spam_score) + common.save_cache(task, digest, rule, symbols_table, spam_score) + end + else + common.save_cache(task, digest, rule, 'OK') + common.log_clean(task, rule, 'no spam detected - spam score: ' .. spam_score .. ', symbols: ' .. symbols) + end + end + end + + tcp.request({ + task = task, + host = addr:to_string(), + port = addr:get_port(), + upstream = upstream, + timeout = rule['timeout'], + data = request_data, + callback = spamassassin_callback, + }) + end + + if common.condition_check_and_continue(task, content, rule, digest, spamassassin_check_uncached) then + return + else + spamassassin_check_uncached() + end + +end + +return { + type = { N, 'spam', 'scanner' }, + description = 'spamassassin spam scanner', + configure = spamassassin_config, + check = spamassassin_check, + name = N +} |