lego/providers/dns/desec/desec.go
2021-02-28 02:23:28 +00:00

180 lines
5.3 KiB
Go

// Package desec implements a DNS provider for solving the DNS-01 challenge using deSEC DNS.
package desec
import (
"errors"
"fmt"
"net/http"
"time"
"github.com/go-acme/lego/v4/challenge/dns01"
"github.com/go-acme/lego/v4/platform/config/env"
"github.com/nrdcg/desec"
)
// Environment variables names.
const (
envNamespace = "DESEC_"
EnvToken = envNamespace + "TOKEN"
EnvTTL = envNamespace + "TTL"
EnvPropagationTimeout = envNamespace + "PROPAGATION_TIMEOUT"
EnvPollingInterval = envNamespace + "POLLING_INTERVAL"
EnvHTTPTimeout = envNamespace + "HTTP_TIMEOUT"
)
// https://github.com/desec-io/desec-stack/issues/216
// https://desec.readthedocs.io/_/downloads/en/latest/pdf/
const defaultTTL int = 3600
// Config is used to configure the creation of the DNSProvider.
type Config struct {
Token string
PropagationTimeout time.Duration
PollingInterval time.Duration
TTL int
HTTPClient *http.Client
}
// NewDefaultConfig returns a default configuration for the DNSProvider.
func NewDefaultConfig() *Config {
return &Config{
TTL: env.GetOrDefaultInt(EnvTTL, defaultTTL),
PropagationTimeout: env.GetOrDefaultSecond(EnvPropagationTimeout, dns01.DefaultPropagationTimeout),
PollingInterval: env.GetOrDefaultSecond(EnvPollingInterval, dns01.DefaultPollingInterval),
HTTPClient: &http.Client{
Timeout: env.GetOrDefaultSecond(EnvHTTPTimeout, 30*time.Second),
},
}
}
// DNSProvider implements the challenge.Provider interface.
type DNSProvider struct {
config *Config
client *desec.Client
}
// NewDNSProvider returns a DNSProvider instance configured for deSEC.
// Credentials must be passed in the environment variable: DESEC_TOKEN.
func NewDNSProvider() (*DNSProvider, error) {
values, err := env.Get(EnvToken)
if err != nil {
return nil, fmt.Errorf("desec: %w", err)
}
config := NewDefaultConfig()
config.Token = values[EnvToken]
return NewDNSProviderConfig(config)
}
// NewDNSProviderConfig return a DNSProvider instance configured for deSEC.
func NewDNSProviderConfig(config *Config) (*DNSProvider, error) {
if config == nil {
return nil, errors.New("desec: the configuration of the DNS provider is nil")
}
if config.Token == "" {
return nil, errors.New("desec: incomplete credentials, missing token")
}
opts := desec.NewDefaultClientOptions()
if config.HTTPClient != nil {
opts.HTTPClient = config.HTTPClient
}
client := desec.New(config.Token, opts)
return &DNSProvider{config: config, client: client}, nil
}
// Timeout returns the timeout and interval to use when checking for DNS propagation.
// Adjusting here to cope with spikes in propagation times.
func (d *DNSProvider) Timeout() (timeout, interval time.Duration) {
return d.config.PropagationTimeout, d.config.PollingInterval
}
// Present creates a TXT record using the specified parameters.
func (d *DNSProvider) Present(domain, token, keyAuth string) error {
fqdn, value := dns01.GetRecord(domain, keyAuth)
quotedValue := fmt.Sprintf(`"%s"`, value)
authZone, err := dns01.FindZoneByFqdn(fqdn)
if err != nil {
return fmt.Errorf("desec: could not find zone for domain %q and fqdn %q : %w", domain, fqdn, err)
}
recordName := getRecordName(fqdn, authZone)
domainName := dns01.UnFqdn(authZone)
rrSet, err := d.client.Records.Get(domainName, recordName, "TXT")
if err != nil {
var nf *desec.NotFound
if !errors.As(err, &nf) {
return fmt.Errorf("desec: failed to get records: domainName=%s, recordName=%s: %w", domainName, recordName, err)
}
// Not found case -> create
_, err = d.client.Records.Create(desec.RRSet{
Domain: domainName,
SubName: recordName,
Type: "TXT",
Records: []string{quotedValue},
TTL: d.config.TTL,
})
if err != nil {
return fmt.Errorf("desec: failed to create records: domainName=%s, recordName=%s: %w", domainName, recordName, err)
}
return nil
}
// update
records := append(rrSet.Records, quotedValue)
_, err = d.client.Records.Update(domainName, recordName, "TXT", desec.RRSet{Records: records})
if err != nil {
return fmt.Errorf("desec: failed to update records: domainName=%s, recordName=%s: %w", domainName, recordName, err)
}
return nil
}
// CleanUp removes the TXT record matching the specified parameters.
func (d *DNSProvider) CleanUp(domain, token, keyAuth string) error {
fqdn, value := dns01.GetRecord(domain, keyAuth)
authZone, err := dns01.FindZoneByFqdn(fqdn)
if err != nil {
return fmt.Errorf("desec: could not find zone for domain %q and fqdn %q : %w", domain, fqdn, err)
}
recordName := getRecordName(fqdn, authZone)
domainName := dns01.UnFqdn(authZone)
rrSet, err := d.client.Records.Get(domainName, recordName, "TXT")
if err != nil {
return fmt.Errorf("desec: failed to get records: domainName=%s, recordName=%s: %w", domainName, recordName, err)
}
records := make([]string, 0)
for _, record := range rrSet.Records {
if record != fmt.Sprintf(`"%s"`, value) {
records = append(records, record)
}
}
_, err = d.client.Records.Update(domainName, recordName, "TXT", desec.RRSet{Records: records})
if err != nil {
return fmt.Errorf("desec: failed to update records: domainName=%s, recordName=%s: %w", domainName, recordName, err)
}
return nil
}
func getRecordName(fqdn, authZone string) string {
return fqdn[0 : len(fqdn)-len(authZone)-1]
}