telebit/internal/dns01/dns01.go

232 lines
6.2 KiB
Go

// Package dns01 implements a DNS provider for solving the DNS-01 challenge through a HTTP server.
package dns01
// Adapted from https://github.com/go-acme/lego/blob/master/providers/dns/httpreq/httpreq.go
import (
"bytes"
"context"
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"log"
"net/http"
"net/url"
"path"
"time"
"github.com/coolaj86/certmagic"
"github.com/go-acme/lego/v3/challenge"
"github.com/go-acme/lego/v3/challenge/dns01"
"github.com/go-acme/lego/v3/platform/config/env"
"github.com/mholt/acmez/acme"
)
// Environment variables names.
const (
envNamespace = "API_"
EnvEndpoint = envNamespace + "ENDPOINT"
EnvToken = envNamespace + "TOKEN"
EnvPropagationTimeout = envNamespace + "PROPAGATION_TIMEOUT"
EnvPollingInterval = envNamespace + "POLLING_INTERVAL"
EnvHTTPTimeout = envNamespace + "HTTP_TIMEOUT"
)
type dnsChallenge struct {
Domain string `json:"domain"`
Hostname string `json:"hostname"`
Token string `json:"token"`
KeyAuth string `json:"key_authorization"`
KeyAuthDigest string `json:"key_authorization_digest"`
}
// Config is used to configure the creation of the DNSProvider.
type Config struct {
Endpoint *url.URL
Token string
PropagationTimeout time.Duration
PollingInterval time.Duration
HTTPClient *http.Client
}
// NewDefaultConfig returns a default configuration for the DNSProvider.
func NewDefaultConfig() *Config {
return &Config{
PropagationTimeout: env.GetOrDefaultSecond(EnvPropagationTimeout, dns01.DefaultPropagationTimeout),
PollingInterval: env.GetOrDefaultSecond(EnvPollingInterval, dns01.DefaultPollingInterval),
HTTPClient: &http.Client{
Timeout: env.GetOrDefaultSecond(EnvHTTPTimeout, 15*time.Second),
},
}
}
// DNSProvider implements the challenge.Provider interface.
type DNSProvider struct {
config *Config
}
// NewDNSProvider returns a DNSProvider instance.
func NewDNSProvider() (*DNSProvider, error) {
values, err := env.Get(EnvEndpoint)
if err != nil {
return nil, fmt.Errorf("dns01 api: %w", err)
}
endpoint, err := url.Parse(values[EnvEndpoint])
if err != nil {
return nil, fmt.Errorf("dns01 api: %w", err)
}
config := NewDefaultConfig()
config.Token = env.GetOrFile(EnvToken)
config.Endpoint = endpoint
return NewDNSProviderConfig(config)
}
// NewDNSProviderConfig return a DNSProvider.
func NewDNSProviderConfig(config *Config) (*DNSProvider, error) {
if config == nil {
return nil, errors.New("api: the configuration of the DNS provider is nil")
}
if config.Endpoint == nil {
return nil, errors.New("api: the endpoint is missing")
}
return &DNSProvider{config: config}, 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 to fulfill the dns-01 challenge.
func (d *DNSProvider) Present(domain, token, keyAuth string) error {
msg := getDNSChallenge(domain, token, keyAuth)
err := d.doRequest(http.MethodPost, fmt.Sprintf("/%s", msg.Domain), msg)
if err != nil {
return fmt.Errorf("api: %w", err)
}
return nil
}
// CleanUp removes the TXT record matching the specified parameters.
func (d *DNSProvider) CleanUp(domain, token, keyAuth string) error {
msg := getDNSChallenge(domain, token, keyAuth)
err := d.doRequest(
http.MethodDelete,
fmt.Sprintf("/%s/%s/%s", msg.Domain, msg.Token, msg.KeyAuth),
nil,
)
if err != nil {
return fmt.Errorf("api: %w", err)
}
return nil
}
func getDNSChallenge(domain, token, keyAuth string) *dnsChallenge {
hostname, digest := dns01.GetRecord(domain, keyAuth)
return &dnsChallenge{
Domain: domain,
Hostname: hostname,
Token: token,
KeyAuth: keyAuth,
KeyAuthDigest: digest,
}
}
func (d *DNSProvider) doRequest(method, uri string, msg interface{}) error {
reqBody := &bytes.Buffer{}
if nil != msg {
err := json.NewEncoder(reqBody).Encode(msg)
if err != nil {
return err
}
}
newURI := path.Join(d.config.Endpoint.EscapedPath(), uri)
endpoint, err := d.config.Endpoint.Parse(newURI)
if err != nil {
return err
}
req, err := http.NewRequest(method, endpoint.String(), reqBody)
if err != nil {
return err
}
req.Header.Set("Content-Type", "application/json")
if len(d.config.Token) > 0 {
req.Header.Set("Authorization", "Bearer "+d.config.Token)
}
resp, err := d.config.HTTPClient.Do(req)
if err != nil {
return err
}
defer resp.Body.Close()
if resp.StatusCode >= http.StatusBadRequest {
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
return fmt.Errorf("%d: failed to read response body: %w", resp.StatusCode, err)
}
return fmt.Errorf("%d: request failed: %v", resp.StatusCode, string(body))
}
return nil
}
// NewSolver creates a new Solver
func NewSolver(provider challenge.Provider) (lego *Solver) {
return &Solver{
provider: provider,
dnsChecker: certmagic.DNS01Solver{},
}
}
// Solver wraps a Lego DNS Provider for CertMagic
type Solver struct {
provider challenge.Provider
//option legoDns01.ChallengeOption
dnsChecker certmagic.DNS01Solver
}
// Present creates a DNS-01 Challenge Token
func (s *Solver) Present(ctx context.Context, ch acme.Challenge) error {
log.Println("Present DNS-01 challenge solution for", ch.Identifier.Value)
return s.provider.Present(ch.Identifier.Value, ch.Token, ch.KeyAuthorization)
}
// CleanUp deletes a DNS-01 Challenge Token
func (s *Solver) CleanUp(ctx context.Context, ch acme.Challenge) error {
log.Println("CleanUp DNS-01 challenge solution for", ch.Identifier.Value)
c := make(chan error)
go func() {
c <- s.provider.CleanUp(ch.Identifier.Value, ch.Token, ch.KeyAuthorization)
}()
select {
case err := <-c:
return err
case <-ctx.Done():
return errors.New("cancelled")
}
}
// Wait blocks until the TXT record created in Present() appears in
// authoritative lookups, i.e. until it has propagated, or until
// timeout, whichever is first.
func (s *Solver) Wait(ctx context.Context, ch acme.Challenge) error {
log.Println("Wait on DNS-01 challenge self-verification for", ch.Identifier.Value)
return s.dnsChecker.Wait(ctx, ch)
}