1
0
forked from infra/ansible
infra/roles/dns-extern/files/updatepolicy.lua

59 lines
2.1 KiB
Lua

function loadaliasesfromfile()
local env = { alias = {} }
local f,err = loadfile("/etc/powerdns/updatepolicy.aliases", "t", env)
if f then
f() -- run the loaded code in the prepared env for safety reasons
pdnslog("Successfully loaded alias config", pdns.loglevels.Debug)
else
pdnslog("Failed to load alias config: "..err, pdns.loglevels.Warning)
end
return env.alias
end
function getacmedomains(domain)
-- Add domain as the first entry to the list
local domains = {[0] = "_acme-challenge."..domain}
local counter = 1
-- Load additional alias domains from config file
local aliases = loadaliasesfromfile()
if aliases[domain] ~= nil then
for _,alias in pairs(aliases[domain]) do
domains[counter] = "_acme-challenge."..alias
counter = counter + 1
end
end
-- Return all challenge domains
return domains
end
function updatepolicy(input)
-- Check for valid TSIG key or fail
local key = input:getTsigName()
local keyname = nil
if key == nil or not pcall(function() keyname = key:toString() end) or keyname == "" then
-- fail on no key (and work around the possible odd exception with pcall)
pdnslog("No TSIG key found. Update rejected.", pdns.loglevels.Error)
return false
end
-- Process ACME keys
local pos,_,domain = string.find(keyname, "^acme%-(.+)")
if pos ~= nil then
for _,acmedomain in pairs(getacmedomains(domain)) do
pdnslog("Validating against "..acmedomain, pdns.loglevels.Debug)
if input:getQType() == pdns.TXT and input:getQName():toString():lower() == acmedomain:lower() then
-- valid acme key with matching domain matches name and TXT
pdnslog("ACME TSIG '"..keyname.."' key found and request matches domain or known aliases. Update permitted.")
return true
end
end
-- acme key and no valid match
pdnslog("ACME TSIG '"..keyname.."' key found but request does not match domain or known aliases. Update rejected.", pdns.loglevels.Error)
return false
end
-- Process other keys with the normal default policy result
pdnslog("TSIG Key '"..keyname.."' found. Update permitted.")
return true
end