--[[ Copyright (c) 2018, Vsevolod Stakhov 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 savapi -- This module contains avira savapi antivirus 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 module_name = "sophos" local default_message = '${SCANNER}: virus found: "${VIRUS}"' local function sophos_config(opts) local sophos_conf = { module_name = module_name, scan_mime_parts = true, scan_text_mime = false, scan_image_mime = false, default_port = 4010, timeout = 15.0, log_clean = false, retransmits = 2, cache_expire = 3600, -- expire redis in one hour message = default_message, savdi_report_encrypted = false, detection_category = "virus", savdi_report_oversize = false, } sophos_conf = lua_util.override_defaults(sophos_conf, opts) if not sophos_conf.prefix then sophos_conf.prefix = 'rs_' .. sophos_conf.name .. '_' end if not sophos_conf.log_prefix then if sophos_conf.name:lower() == sophos_conf.type:lower() then sophos_conf.log_prefix = sophos_conf.name else sophos_conf.log_prefix = sophos_conf.name .. ' (' .. sophos_conf.type .. ')' end end if not sophos_conf['servers'] then rspamd_logger.errx(rspamd_config, 'no servers defined') return nil end sophos_conf['upstreams'] = upstream_list.create(rspamd_config, sophos_conf['servers'], sophos_conf.default_port) if sophos_conf['upstreams'] then lua_util.add_debug_alias('antivirus', sophos_conf.module_name) return sophos_conf end rspamd_logger.errx(rspamd_config, 'cannot parse servers %s', sophos_conf['servers']) return nil end local function sophos_check(task, content, digest, rule) local function sophos_check_uncached () local upstream = rule.upstreams:get_upstream_round_robin() local addr = upstream:get_addr() local retransmits = rule.retransmits local protocol = 'SSSP/1.0\n' local streamsize = string.format('SCANDATA %d\n', #content) local bye = 'BYE\n' local function sophos_callback(err, data, conn) if err then -- set current upstream to fail because an error occurred upstream:fail() -- retry with another upstream until retransmits exceeds if retransmits > 0 then retransmits = retransmits - 1 -- Select a different upstream! upstream = rule.upstreams:get_upstream_round_robin() addr = upstream:get_addr() lua_util.debugm(rule.module_name, task, '%s [%s]: retry IP: %s', rule['symbol'], rule['type'], addr) tcp.request({ task = task, host = addr:to_string(), port = addr:get_port(), timeout = rule['timeout'], callback = sophos_callback, data = { protocol, streamsize, content, bye } }) else rspamd_logger.errx(task, '%s [%s]: failed to scan, maximum retransmits exceed', rule['symbol'], rule['type']) task:insert_result(rule['symbol_fail'], 0.0, 'failed to scan and retransmits exceed') end else upstream:ok() data = tostring(data) lua_util.debugm(rule.module_name, task, '%s [%s]: got reply: %s', rule['symbol'], rule['type'], data) local vname = string.match(data, 'VIRUS (%S+) ') if vname then common.yield_result(task, rule, vname) common.save_av_cache(task, digest, rule, vname) else if string.find(data, 'DONE OK') then if rule['log_clean'] then rspamd_logger.infox(task, '%s: message or mime_part is clean', rule.log_prefix) else lua_util.debugm(rule.module_name, task, '%s: message or mime_part is clean', rule.log_prefix) end common.save_av_cache(task, digest, rule, 'OK') -- not finished - continue elseif string.find(data, 'ACC') or string.find(data, 'OK SSSP') then conn:add_read(sophos_callback) -- set pseudo virus if configured, else do nothing since it's no fatal elseif string.find(data, 'FAIL 0212') then rspamd_logger.infox(task, 'Message is ENCRYPTED (0212 SOPHOS_SAVI_ERROR_FILE_ENCRYPTED): %s', data) if rule['savdi_report_encrypted'] then common.yield_result(task, rule, "SAVDI_FILE_ENCRYPTED") common.save_av_cache(task, digest, rule, "SAVDI_FILE_ENCRYPTED") end -- set pseudo virus if configured, else set fail since part was not scanned elseif string.find(data, 'REJ 4') then if rule['savdi_report_oversize'] then rspamd_logger.infox(task, 'SAVDI: Message is OVERSIZED (SSSP reject code 4): %s', data) common.yield_result(task, rule, "SAVDI_FILE_OVERSIZED") common.save_av_cache(task, digest, rule, "SAVDI_FILE_OVERSIZED") else rspamd_logger.errx(task, 'SAVDI: Message is OVERSIZED (SSSP reject code 4): %s', data) task:insert_result(rule['symbol_fail'], 0.0, 'Message is OVERSIZED (SSSP reject code 4):' .. data) end -- excplicitly set REJ1 message when SAVDIreports a protocol error elseif string.find(data, 'REJ 1') then rspamd_logger.errx(task, 'SAVDI (Protocol error (REJ 1)): %s', data) task:insert_result(rule['symbol_fail'], 0.0, 'SAVDI (Protocol error (REJ 1)):' .. data) else rspamd_logger.errx(task, 'unhandled response: %s', data) task:insert_result(rule['symbol_fail'], 0.0, 'unhandled response') end end end end tcp.request({ task = task, host = addr:to_string(), port = addr:get_port(), timeout = rule['timeout'], callback = sophos_callback, data = { protocol, streamsize, content, bye } }) end if common.need_av_check(task, content, rule) then if common.check_av_cache(task, digest, rule, sophos_check_uncached) then return else sophos_check_uncached() end end end return { type = 'antivirus', description = 'sophos antivirus', configure = sophos_config, check = sophos_check, name = module_name }