mirror of
https://github.com/rspamd/rspamd.git
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189 lines
6.0 KiB
Lua
189 lines
6.0 KiB
Lua
--[[
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Copyright (c) 2018, Vsevolod Stakhov <vsevolod@highsecure.ru>
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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]]--
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--[[[
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-- @module clamav
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-- This module contains clamav access functions
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--]]
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local lua_util = require "lua_util"
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local tcp = require "rspamd_tcp"
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local upstream_list = require "rspamd_upstream_list"
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local rspamd_util = require "rspamd_util"
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local rspamd_logger = require "rspamd_logger"
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local common = require "lua_scanners/common"
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local N = "clamav"
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local default_message = '${SCANNER}: virus found: "${VIRUS}"'
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local function clamav_config(opts)
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local clamav_conf = {
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name = N,
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scan_mime_parts = true,
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scan_text_mime = false,
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scan_image_mime = false,
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default_port = 3310,
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log_clean = false,
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timeout = 5.0, -- FIXME: this will break task_timeout!
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detection_category = "virus",
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retransmits = 2,
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cache_expire = 3600, -- expire redis in one hour
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message = default_message,
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}
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clamav_conf = lua_util.override_defaults(clamav_conf, opts)
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if not clamav_conf.prefix then
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clamav_conf.prefix = 'rs_' .. clamav_conf.name .. '_'
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end
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if not clamav_conf.log_prefix then
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if clamav_conf.name:lower() == clamav_conf.type:lower() then
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clamav_conf.log_prefix = clamav_conf.name
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else
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clamav_conf.log_prefix = clamav_conf.name .. ' (' .. clamav_conf.type .. ')'
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end
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end
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if not clamav_conf['servers'] then
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rspamd_logger.errx(rspamd_config, 'no servers defined')
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return nil
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end
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clamav_conf['upstreams'] = upstream_list.create(rspamd_config,
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clamav_conf['servers'],
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clamav_conf.default_port)
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if clamav_conf['upstreams'] then
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lua_util.add_debug_alias('antivirus', clamav_conf.name)
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return clamav_conf
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end
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rspamd_logger.errx(rspamd_config, 'cannot parse servers %s',
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clamav_conf['servers'])
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return nil
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end
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local function clamav_check(task, content, digest, rule)
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local function clamav_check_uncached ()
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local upstream = rule.upstreams:get_upstream_round_robin()
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local addr = upstream:get_addr()
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local retransmits = rule.retransmits
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local header = rspamd_util.pack("c9 c1 >I4", "zINSTREAM", "\0",
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#content)
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local footer = rspamd_util.pack(">I4", 0)
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local function clamav_callback(err, data)
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if err then
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-- set current upstream to fail because an error occurred
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upstream:fail()
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-- retry with another upstream until retransmits exceeds
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if retransmits > 0 then
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retransmits = retransmits - 1
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-- Select a different upstream!
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upstream = rule.upstreams:get_upstream_round_robin()
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addr = upstream:get_addr()
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lua_util.debugm(rule.name, task, '%s: error: %s; retry IP: %s; retries left: %s',
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rule.log_prefix, err, addr, retransmits)
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tcp.request({
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task = task,
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host = addr:to_string(),
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port = addr:get_port(),
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timeout = rule['timeout'],
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callback = clamav_callback,
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data = { header, content, footer },
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stop_pattern = '\0'
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})
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else
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rspamd_logger.errx(task, '%s: failed to scan, maximum retransmits exceed', rule.log_prefix)
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common.yield_result(task, rule, 'failed to scan and retransmits exceed', 0.0, 'fail')
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end
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else
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upstream:ok()
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data = tostring(data)
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local cached
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lua_util.debugm(rule.name, task, '%s: got reply: %s',
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rule.log_prefix, data)
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if data == 'stream: OK' then
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cached = 'OK'
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if rule['log_clean'] then
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rspamd_logger.infox(task, '%s: message or mime_part is clean',
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rule.log_prefix)
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else
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lua_util.debugm(rule.name, task, '%s: message or mime_part is clean', rule.log_prefix)
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end
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else
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local vname = string.match(data, 'stream: (.+) FOUND')
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if string.find(vname, '^Heuristics%.Encrypted') then
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rspamd_logger.errx(task, '%s: File is encrypted', rule.log_prefix)
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common.yield_result(task, rule, 'File is encrypted: '.. vname, 0.0, 'encrypted')
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cached = 'encrypted'
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elseif string.find(vname, '^Heuristics%.OLE2%.ContainsMacros') then
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rspamd_logger.errx(task, '%s: ClamAV Found an OLE2 Office Macro', rule.log_prefix)
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common.yield_result(task, rule, vname, 0.0, 'macro')
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elseif string.find(vname, '^Heuristics%.Limits%.Exceeded') then
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rspamd_logger.errx(task, '%s: ClamAV Limits Exceeded', rule.log_prefix)
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common.yield_result(task, rule, 'Limits Exceeded: '.. vname, 0.0, 'fail')
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elseif vname then
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common.yield_result(task, rule, vname)
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cached = vname
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else
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rspamd_logger.errx(task, '%s: unhandled response: %s', rule.log_prefix, data)
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common.yield_result(task, rule, 'unhandled response:' .. vname, 0.0, 'fail')
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end
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end
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if cached then
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common.save_cache(task, digest, rule, cached)
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end
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end
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end
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tcp.request({
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task = task,
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host = addr:to_string(),
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port = addr:get_port(),
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timeout = rule['timeout'],
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callback = clamav_callback,
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data = { header, content, footer },
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stop_pattern = '\0'
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})
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end
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if common.condition_check_and_continue(task, content, rule, digest, clamav_check_uncached) then
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return
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else
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clamav_check_uncached()
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end
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end
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return {
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type = 'antivirus',
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description = 'clamav antivirus',
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configure = clamav_config,
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check = clamav_check,
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name = N
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}
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