func (r *DNSProvider) changeRecord(action, fqdn, value string, ttl int) error {
// Find the zone for the given fqdn
zone, err := acme.FindZoneByFqdn(fqdn, []string{r.nameserver})
if err != nil {
return err
}
// Create RR
rr := new(dns.TXT)
rr.Hdr = dns.RR_Header{Name: fqdn, Rrtype: dns.TypeTXT, Class: dns.ClassINET, Ttl: uint32(ttl)}
rr.Txt = []string{value}
rrs := []dns.RR{rr}
// Create dynamic update packet
m := new(dns.Msg)
m.SetUpdate(zone)
switch action {
case "INSERT":
// Always remove old challenge left over from who knows what.
m.RemoveRRset(rrs)
m.Insert(rrs)
case "REMOVE":
m.Remove(rrs)
default:
return fmt.Errorf("Unexpected action: %s", action)
}
// Setup client
c := new(dns.Client)
c.SingleInflight = true
// TSIG authentication / msg signing
if len(r.tsigKey) > 0 && len(r.tsigSecret) > 0 {
m.SetTsig(dns.Fqdn(r.tsigKey), r.tsigAlgorithm, 300, time.Now().Unix())
c.TsigSecret = map[string]string{dns.Fqdn(r.tsigKey): r.tsigSecret}
}
// Send the query
reply, _, err := c.Exchange(m, r.nameserver)
if err != nil {
return fmt.Errorf("DNS update failed: %v", err)
}
if reply != nil && reply.Rcode != dns.RcodeSuccess {
return fmt.Errorf("DNS update failed. Server replied: %s", dns.RcodeToString[reply.Rcode])
}
return nil
}
// Dynamically remove a set of RR records stored in DNS
func (s *Service) RemoveRRset(zone string, rr []dns.RR) error {
m := new(dns.Msg)
m.SetUpdate(zone)
m.SetTsig(dns.Fqdn(s.Key), dns.HmacMD5, 300, time.Now().Unix())
m.RemoveRRset(rr)
h, err := s.ServerPort()
if err != nil {
return err
}
c := new(dns.Client)
c.TsigSecret = map[string]string{dns.Fqdn(s.Key): s.Secret}
r, _, err := c.Exchange(m, h)
if err != nil {
return err
}
if r.Rcode != dns.RcodeSuccess {
return errors.New(fmt.Sprintf("invalid exchange answer"))
}
return nil
}
func TestRFC2136ValidUpdatePacket(t *testing.T) {
acme.ClearFqdnCache()
dns.HandleFunc(rfc2136TestZone, serverHandlerPassBackRequest)
defer dns.HandleRemove(rfc2136TestZone)
server, addrstr, err := runLocalDNSTestServer("127.0.0.1:0", false)
if err != nil {
t.Fatalf("Failed to start test server: %v", err)
}
defer server.Shutdown()
txtRR, _ := dns.NewRR(fmt.Sprintf("%s %d IN TXT %s", rfc2136TestFqdn, rfc2136TestTTL, rfc2136TestValue))
rrs := []dns.RR{txtRR}
m := new(dns.Msg)
m.SetUpdate(rfc2136TestZone)
m.RemoveRRset(rrs)
m.Insert(rrs)
expectstr := m.String()
expect, err := m.Pack()
if err != nil {
t.Fatalf("Error packing expect msg: %v", err)
}
provider, err := NewDNSProvider(addrstr, "", "", "")
if err != nil {
t.Fatalf("Expected NewDNSProvider() to return no error but the error was -> %v", err)
}
if err := provider.Present(rfc2136TestDomain, "", "1234d=="); err != nil {
t.Errorf("Expected Present() to return no error but the error was -> %v", err)
}
rcvMsg := <-reqChan
rcvMsg.Id = m.Id
actual, err := rcvMsg.Pack()
if err != nil {
t.Fatalf("Error packing actual msg: %v", err)
}
if !bytes.Equal(actual, expect) {
tmp := new(dns.Msg)
if err := tmp.Unpack(actual); err != nil {
t.Fatalf("Error unpacking actual msg: %v", err)
}
t.Errorf("Expected msg:\n%s", expectstr)
t.Errorf("Actual msg:\n%v", tmp)
}
}
func (r *RFC2136Provider) RemoveRecord(record utils.DnsRecord) error {
logrus.Debugf("Removing RRset '%s %s'", record.Fqdn, record.Type)
m := new(dns.Msg)
m.SetUpdate(r.zoneName)
rr, err := dns.NewRR(fmt.Sprintf("%s 0 %s 0.0.0.0", record.Fqdn, record.Type))
if err != nil {
return fmt.Errorf("Could not construct RR: %v", err)
}
rrs := make([]dns.RR, 1)
rrs[0] = rr
m.RemoveRRset(rrs)
err = r.sendMessage(m)
if err != nil {
return fmt.Errorf("RFC2136 query failed: %v", err)
}
return nil
}