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Editing: lua_auth_results.lua
--[[ Copyright (c) 2016-2026, Vsevolod Stakhov <vsevolod@rspamd.com> 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. ]]-- local rspamd_util = require "rspamd_util" local lua_util = require "lua_util" local default_settings = { spf_symbols = { pass = 'R_SPF_ALLOW', fail = 'R_SPF_FAIL', softfail = 'R_SPF_SOFTFAIL', neutral = 'R_SPF_NEUTRAL', temperror = 'R_SPF_DNSFAIL', none = 'R_SPF_NA', permerror = 'R_SPF_PERMFAIL', }, dmarc_symbols = { pass = 'DMARC_POLICY_ALLOW', permerror = 'DMARC_BAD_POLICY', temperror = 'DMARC_DNSFAIL', none = 'DMARC_NA', reject = 'DMARC_POLICY_REJECT', softfail = 'DMARC_POLICY_SOFTFAIL', quarantine = 'DMARC_POLICY_QUARANTINE', }, arc_symbols = { pass = 'ARC_ALLOW', permerror = 'ARC_INVALID', temperror = 'ARC_DNSFAIL', none = 'ARC_NA', reject = 'ARC_REJECT', }, dkim_symbols = { none = 'R_DKIM_NA', }, add_smtp_user = true, } local exports = { default_settings = default_settings } local local_hostname = rspamd_util.get_hostname() local function gen_auth_results(task, settings) local auth_results, hdr_parts = {}, {} if not settings then settings = default_settings end local auth_types = { dkim = settings.dkim_symbols, dmarc = settings.dmarc_symbols, spf = settings.spf_symbols, arc = settings.arc_symbols, } local common = { symbols = {} } local mta_hostname = task:get_request_header('MTA-Name') or task:get_request_header('MTA-Tag') if mta_hostname then mta_hostname = tostring(mta_hostname) else mta_hostname = local_hostname end table.insert(hdr_parts, mta_hostname) for auth_type, symbols in pairs(auth_types) do for key, sym in pairs(symbols) do if not common.symbols.sym then local s = task:get_symbol(sym) if not s then common.symbols[sym] = false else common.symbols[sym] = s if not auth_results[auth_type] then auth_results[auth_type] = { key } else table.insert(auth_results[auth_type], key) end if auth_type ~= 'dkim' then break end end end end end local dkim_results = task:get_dkim_results() -- For each signature we set authentication results -- dkim=neutral (body hash did not verify) header.d=example.com header.s=sel header.b=fA8VVvJ8; -- dkim=neutral (body hash did not verify) header.d=example.com header.s=sel header.b=f8pM8o90; for _, dres in ipairs(dkim_results) do local ar_string = 'none' if dres.result == 'reject' then ar_string = 'fail' -- imply failure, not neutral elseif dres.result == 'allow' then ar_string = 'pass' elseif dres.result == 'bad record' or dres.result == 'permerror' or dres.result == 'permfail' then ar_string = 'permerror' elseif dres.result == 'tempfail' then ar_string = 'temperror' end local hdr = {} hdr[1] = string.format('dkim=%s', ar_string) if dres.fail_reason then hdr[#hdr + 1] = string.format('(%s)', lua_util.maybe_smtp_quote_value(dres.fail_reason)) end if dres.domain then hdr[#hdr + 1] = string.format('header.d=%s', lua_util.maybe_smtp_quote_value(dres.domain)) end if dres.selector then hdr[#hdr + 1] = string.format('header.s=%s', lua_util.maybe_smtp_quote_value(dres.selector)) end if dres.bhash then hdr[#hdr + 1] = string.format('header.b=%s', lua_util.maybe_smtp_quote_value(dres.bhash)) end table.insert(hdr_parts, table.concat(hdr, ' ')) end if #dkim_results == 0 then -- We have no dkim results, so check for DKIM_NA symbol if common.symbols[settings.dkim_symbols.none] then table.insert(hdr_parts, 'dkim=none') end end for auth_type, keys in pairs(auth_results) do for _, key in ipairs(keys) do local hdr = '' if auth_type == 'dmarc' then local opts = common.symbols[auth_types['dmarc'][key]][1]['options'] or {} hdr = hdr .. 'dmarc=' if key == 'reject' or key == 'quarantine' or key == 'softfail' then hdr = hdr .. 'fail' else hdr = hdr .. lua_util.maybe_smtp_quote_value(key) end if key == 'pass' then hdr = hdr .. ' (policy=' .. lua_util.maybe_smtp_quote_value(opts[2]) .. ')' hdr = hdr .. ' header.from=' .. lua_util.maybe_smtp_quote_value(opts[1]) elseif key ~= 'none' then local t = { opts[1]:match('^([^%s]+) : (.*)$') } if #t > 0 then local dom = t[1] local rsn = t[2] if rsn then hdr = string.format('%s reason=%s', hdr, lua_util.maybe_smtp_quote_value(rsn)) end hdr = string.format('%s header.from=%s', hdr, lua_util.maybe_smtp_quote_value(dom)) end if key == 'softfail' then hdr = hdr .. ' (policy=none)' else hdr = hdr .. ' (policy=' .. lua_util.maybe_smtp_quote_value(key) .. ')' end end table.insert(hdr_parts, hdr) elseif auth_type == 'arc' then if common.symbols[auth_types['arc'][key]][1] then local opts = common.symbols[auth_types['arc'][key]][1]['options'] or {} for _, v in ipairs(opts) do hdr = string.format('%s%s=%s (%s)', hdr, auth_type, lua_util.maybe_smtp_quote_value(key), lua_util.maybe_smtp_quote_value(v)) table.insert(hdr_parts, hdr) end end elseif auth_type == 'spf' then -- Main type local sender local sender_type local smtp_from = task:get_from({ 'smtp', 'orig' }) if smtp_from and smtp_from[1] and smtp_from[1]['addr'] ~= '' and smtp_from[1]['addr'] ~= nil then sender = lua_util.maybe_smtp_quote_value(smtp_from[1]['addr']) sender_type = 'smtp.mailfrom' else local helo = task:get_helo() if helo then sender = lua_util.maybe_smtp_quote_value(helo) sender_type = 'smtp.helo' end end if sender and sender_type then -- Comment line local comment = '' if key == 'pass' then comment = string.format('%s: domain of %s designates %s as permitted sender', mta_hostname, sender, tostring(task:get_from_ip() or 'unknown')) elseif key == 'fail' then comment = string.format('%s: domain of %s does not designate %s as permitted sender', mta_hostname, sender, tostring(task:get_from_ip() or 'unknown')) elseif key == 'neutral' or key == 'softfail' then comment = string.format('%s: %s is neither permitted nor denied by domain of %s', mta_hostname, tostring(task:get_from_ip() or 'unknown'), sender) elseif key == 'permerror' then comment = string.format('%s: domain of %s uses mechanism not recognized by this client', mta_hostname, sender) elseif key == 'temperror' then comment = string.format('%s: error in processing during lookup of %s: DNS error', mta_hostname, sender) elseif key == 'none' then comment = string.format('%s: domain of %s has no SPF policy when checking %s', mta_hostname, sender, tostring(task:get_from_ip() or 'unknown')) end hdr = string.format('%s=%s (%s) %s=%s', auth_type, key, comment, sender_type, sender) else hdr = string.format('%s=%s', auth_type, key) end table.insert(hdr_parts, hdr) end end end local u = task:get_user() local smtp_from = task:get_from({ 'smtp', 'orig' }) if u and smtp_from then local hdr = { [1] = 'auth=pass' } if settings['add_smtp_user'] then table.insert(hdr, 'smtp.auth=' .. lua_util.maybe_smtp_quote_value(u)) end if smtp_from[1]['addr'] then table.insert(hdr, 'smtp.mailfrom=' .. lua_util.maybe_smtp_quote_value(smtp_from[1]['addr'])) end table.insert(hdr_parts, table.concat(hdr, ' ')) end if #hdr_parts > 0 then if #hdr_parts == 1 then hdr_parts[2] = 'none' end return table.concat(hdr_parts, '; ') end return nil end exports.gen_auth_results = gen_auth_results -- Shared LPeg primitives for AR/AAR parsing (built once on first use) local ar_lpeg_atoms local function get_ar_lpeg_atoms() if ar_lpeg_atoms then return ar_lpeg_atoms end local lpeg = require "lpeg" local P, S, V, C, Ct, Cg, Cf = lpeg.P, lpeg.S, lpeg.V, lpeg.C, lpeg.Ct, lpeg.Cg, lpeg.Cf local space = S(" \t") ^ 0 local doublequoted = space * P '"' * ((1 - S '"\r\n\f\\') + (P '\\' * 1)) ^ 0 * '"' * space local comment = space * P { "(" * ((1 - S "()") + V(1)) ^ 0 * ")" } * space local name = C((1 - S('=(" \t')) ^ 1) * space local pair = Cg(name * "=" * space * name) * space -- Single AR element grammar: "dkim=pass (comment) header.d=example.com" → table local elt_grammar = Cf(Ct("") * (pair + comment + doublequoted) ^ 1, rawset) -- AAR header split grammar: splits on ";" while respecting comments and quotes. -- Each captured element is the raw text between semicolons (trimmed). local safe_char = (comment + doublequoted + (1 - S ";")) -- consume one "safe" token local element = C(safe_char ^ 1) -- capture the raw text of one element local sep = P ";" * space local aar_split_grammar = Ct(space * element * (sep * element) ^ 0) ar_lpeg_atoms = { elt_grammar = elt_grammar, aar_split_grammar = aar_split_grammar, } return ar_lpeg_atoms end -- Parse a single AR element (e.g. "dkim=pass header.d=example.com") into a kv table local function parse_ar_element(elt) return get_ar_lpeg_atoms().elt_grammar:match(elt) end exports.parse_ar_element = parse_ar_element -- Split an AAR header value into elements by ";" while respecting comments and -- quoted strings, then parse each element. Returns { i = <number>, -- ar = { {method=result, ...}, ... } } or nil on failure. local function parse_aar_header(decoded) local atoms = get_ar_lpeg_atoms() local elts = atoms.aar_split_grammar:match(decoded) if not elts or #elts == 0 then return nil end local result = {} for _, raw_elt in ipairs(elts) do local trimmed = raw_elt:match("^%s*(.-)%s*$") if trimmed and #trimmed > 0 and trimmed:match("^i%s*=%s*%d+$") then -- ARC instance tag local v = trimmed:match("^i%s*=%s*(%d+)$") result.i = v else -- Try to parse as an AR element (method=result prop=value ...) local ar_elt = atoms.elt_grammar:match(trimmed) if ar_elt then if not result.ar then result.ar = {} end table.insert(result.ar, ar_elt) end -- Elements without '=' (like authserv-id) are silently skipped end end return result end exports.parse_aar_header = parse_aar_header local function get_ar_hostname(ar_value) if not ar_value or ar_value == '' then return nil end local hostname = ar_value:match('^%s*([^;%s%(]+)') if hostname then return hostname:lower() end return nil end exports.get_ar_hostname = get_ar_hostname return exports
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