orchid/renewal/service.go

509 lines
15 KiB
Go

package renewal
import (
"bytes"
"crypto/rsa"
"crypto/tls"
"crypto/x509"
"database/sql"
_ "embed"
"encoding/pem"
"errors"
"fmt"
"github.com/MrMelon54/orchid/pebble"
"github.com/go-acme/lego/v4/certificate"
"github.com/go-acme/lego/v4/challenge"
"github.com/go-acme/lego/v4/challenge/dns01"
"github.com/go-acme/lego/v4/lego"
"github.com/go-acme/lego/v4/providers/dns/duckdns"
"github.com/go-acme/lego/v4/providers/dns/namesilo"
"github.com/go-acme/lego/v4/registration"
"io"
"log"
"net/http"
"os"
"path/filepath"
"sync"
"time"
)
var (
ErrUnsupportedDNSProvider = errors.New("unsupported DNS provider")
//go:embed find-next-cert.sql
findNextCertSql string
//go:embed create-tables.sql
createTableCertificates string
)
// overrides only used in testing
var testDnsOptions interface {
challenge.Provider
GetDnsAddrs() []string
}
// Service manages the scheduled renewal of certificates stored in the database
// and outputs the latest certificates to the certDir folder. If the certificate
// does not have a key already defined in keyDir then a new key is generated.
//
// The service makes use of an HTTP ACME challenge provider, and a DNS ACME
// challenge provider. These ensure the `.wellknown/acme-challenges` files and
// `_acme-challenges` TXT records are updated to validate the ownership of the
// specified domains.
type Service struct {
db *sql.DB
httpAcme challenge.Provider
certTicker *time.Ticker
certDone chan struct{}
caAddr string
caCert []byte
transport http.RoundTripper
renewLock *sync.Mutex
leAccount *Account
certDir string
keyDir string
insecure bool
}
// NewService creates a new certificate renewal service.
func NewService(wg *sync.WaitGroup, db *sql.DB, httpAcme challenge.Provider, leConfig LetsEncryptConfig, certDir, keyDir string) (*Service, error) {
r := &Service{
db: db,
httpAcme: httpAcme,
certTicker: time.NewTicker(time.Minute * 10),
certDone: make(chan struct{}),
renewLock: &sync.Mutex{},
leAccount: &Account{
email: leConfig.Account.Email,
},
certDir: certDir,
keyDir: keyDir,
insecure: leConfig.insecure,
}
// make certDir and keyDir
err := os.MkdirAll(certDir, os.ModePerm)
if err != nil {
return nil, fmt.Errorf("failed to create certDir '%s': %w", certDir, err)
}
err = os.MkdirAll(keyDir, os.ModePerm)
if err != nil {
return nil, fmt.Errorf("failed to create certDir '%s': %w", certDir, err)
}
// load lets encrypt private key
err = r.resolveLEPrivKey(leConfig.Account.PrivateKey)
if err != nil {
return nil, fmt.Errorf("failed to resolve LetsEncrypt account private key: %w", err)
}
// init domains table
_, err = r.db.Exec(createTableCertificates)
if err != nil {
return nil, fmt.Errorf("failed to create certificates table: %w", err)
}
// resolve CA information
r.resolveCADirectory(leConfig.Directory)
err = r.resolveCACertificate(leConfig.Certificate)
if err != nil {
return nil, fmt.Errorf("failed to resolve CA certificate: %w", err)
}
// start the background routine
wg.Add(1)
go r.renewalRoutine(wg)
return r, nil
}
// Shutdown the renewal service.
func (s *Service) Shutdown() {
log.Println("[Renewal] Shutting down certificate renewal service")
close(s.certDone)
}
// resolveLEPrivKey resolves the private key for the LetsEncrypt account.
// If the string is a path to a file then the contents of the file is read.
func (s *Service) resolveLEPrivKey(a string) error {
p, _ := pem.Decode([]byte(a))
if p == nil {
return fmt.Errorf("failed to parse pem encoding")
}
if p.Type != "RSA PRIVATE KEY" {
return fmt.Errorf("invalid key types: %s", p.Type)
}
key, err := x509.ParsePKCS1PrivateKey(p.Bytes)
if err != nil {
return fmt.Errorf("failed to parse key: %w", err)
}
s.leAccount.key = key
return err
}
// resolveCADirectory resolves the certificate authority directory URL.
//
// If "production" or "prod" then the LetsEncrypt production directory is used.
//
// If "staging" then the LetsEncrypt staging directory is used.
//
// Otherwise, the string is assumed to be a value directory URL (used for testing
// with pebble).
func (s *Service) resolveCADirectory(dir string) {
switch dir {
case "production", "prod":
s.caAddr = lego.LEDirectoryProduction
case "staging":
s.caAddr = lego.LEDirectoryStaging
default:
s.caAddr = dir
}
}
// resolveCACertificate resolves the certificate authority root certificate.
//
// If "default" is used then the internal library lego defaults to the
// LetsEncrypt production root certificate.
//
// If "pebble" is used then the pebble certificate is used.
func (s *Service) resolveCACertificate(cert string) error {
switch cert {
case "default":
// no nothing
case "pebble":
s.caCert = pebble.RawCert
case "insecure":
s.caCert = []byte{0x00}
default:
s.caCert = []byte(cert)
}
if s.caCert != nil {
if bytes.Compare([]byte{0x00}, s.caCert) == 0 {
t := http.DefaultTransport.(*http.Transport).Clone()
t.TLSClientConfig.InsecureSkipVerify = true
s.transport = t
} else {
caPool := x509.NewCertPool()
if !caPool.AppendCertsFromPEM(s.caCert) {
return fmt.Errorf("failed to add certificate to CA cert pool")
}
t := http.DefaultTransport.(*http.Transport).Clone()
t.TLSClientConfig = &tls.Config{RootCAs: caPool}
s.transport = t
}
}
return nil
}
var ErrAlreadyRenewing = errors.New("already renewing")
// renewalRoutine is the main loop which makes used of certTicker to constantly
// check if the existing certificates are up-to-date.
func (s *Service) renewalRoutine(wg *sync.WaitGroup) {
// Upon leaving the function stop the ticker and clear the WaitGroup.
defer func() {
s.certTicker.Stop()
log.Println("[Renewal] Stopped certificate renewal service")
wg.Done()
}()
// Do an initial check and refuse to start if any errors occur.
log.Println("[Renewal] Doing quick certificate check before starting...")
err := s.renewalCheck()
if err != nil {
log.Println("[Renewal] Certificate check, should not error first try: ", err)
return
}
// Logging or something
log.Println("[Renewal] Initial check complete, continually checking every 10 minutes...")
// Main loop
for {
select {
case <-s.certDone:
// Exit if certDone has closed
return
case <-s.certTicker.C:
// Start a new check in a separate routine
go func() {
// run a renewal check and log errors, but ignore ErrAlreadyRenewing
err := s.renewalCheck()
if err != nil && err != ErrAlreadyRenewing {
log.Println("[Renewal] Certificate check, an error occurred: ", err)
}
}()
}
}
}
// renewalCheck runs a locked renewal check, this only returns and unlocks once a
// renewal finishes or if no certificate needs to renew.
func (s *Service) renewalCheck() error {
if !s.renewLock.TryLock() {
return ErrAlreadyRenewing
}
defer s.renewLock.Unlock()
// check for running out certificates in the database
localData, err := s.findNextCertificateToRenew()
if err != nil {
return fmt.Errorf("failed to find a certificate to renew: %w", err)
}
// no certificates to update
if localData == nil {
return nil
}
// renew the certificate from the collected data
err = s.renewCert(localData)
if err != nil {
return err
}
// renew succeeded
log.Printf("[Renewal] Updated certificate %d successfully\n", localData.id)
return nil
}
// findNextCertificateToRenew finds a certificate to update
func (s *Service) findNextCertificateToRenew() (*localCertData, error) {
d := &localCertData{}
// sql or something, the query is in `find-next-cert.sql`
row, err := s.db.Query(findNextCertSql)
if err != nil {
return nil, fmt.Errorf("failed to run query: %w", err)
}
defer row.Close()
// if next fails no rows were found
if !row.Next() {
return nil, nil
}
// scan the first row
err = row.Scan(&d.id, &d.notAfter, &d.dns.name, &d.dns.token)
switch err {
case nil:
// no nothing
break
case io.EOF:
// no certificate to update
return nil, nil
default:
return nil, fmt.Errorf("failed to scan table row: %w", err)
}
return d, nil
}
func (s *Service) fetchDomains(localData *localCertData) ([]string, error) {
// more sql: this one just grabs all the domains for a certificate
query, err := s.db.Query(`SELECT domain FROM certificate_domains WHERE cert_id = ?`, localData.id)
if err != nil {
return nil, fmt.Errorf("failed to fetch domains for certificate: %d: %w", localData.id, err)
}
// convert query responses to a string slice
domains := make([]string, 0)
for query.Next() {
var domain string
err := query.Scan(&domain)
if err != nil {
return nil, fmt.Errorf("failed to scan row from domains table: %d: %w", localData.id, err)
}
domains = append(domains, domain)
}
// if no domains were found then the renewal will fail
if len(domains) == 0 {
return nil, fmt.Errorf("no domains registered for certificate: %d", localData.id)
}
return domains, nil
}
func (s *Service) setupLegoClient(localData *localCertData) (*lego.Client, error) {
// create lego config and change the certificate authority directory URL and the
// http.Client transport if an alternative is provided
config := lego.NewConfig(s.leAccount)
config.CADirURL = s.caAddr
if s.transport != nil {
config.HTTPClient.Transport = s.transport
}
// create lego client from the config
client, err := lego.NewClient(config)
if err != nil {
return nil, fmt.Errorf("failed to generate client: %w", err)
}
// set http challenge provider
_ = client.Challenge.SetHTTP01Provider(s.httpAcme)
// if testDnsOptions is defined then set up the test provider
if testDnsOptions != nil {
// set up the dns provider used during tests and disable propagation as no dns
// will validate these tests
dnsAddrs := testDnsOptions.GetDnsAddrs()
log.Printf("Using testDnsOptions with DNS server: %v\n", dnsAddrs)
_ = client.Challenge.SetDNS01Provider(testDnsOptions, dns01.AddRecursiveNameservers(dnsAddrs), dns01.DisableCompletePropagationRequirement())
} else if localData.dns.name.Valid && localData.dns.token.Valid {
// if the dns name and token are "valid" meaning non-null in this case
// set up the specific dns provider requested
dnsProv, err := s.getDnsProvider(localData.dns.name.String, localData.dns.token.String)
if err != nil {
return nil, fmt.Errorf("failed to resolve dns provider: %w", err)
}
_ = client.Challenge.SetDNS01Provider(dnsProv)
}
// make sure the LetsEncrypt account is registered
register, err := client.Registration.Register(registration.RegisterOptions{TermsOfServiceAgreed: true})
if err != nil {
return nil, fmt.Errorf("failed to update account registration: %w", err)
}
// return and use the client
s.leAccount.reg = register
return client, nil
}
// getDnsProvider loads a DNS challenge provider using the provided name and
// token
func (s *Service) getDnsProvider(name, token string) (challenge.Provider, error) {
switch name {
case "duckdns":
config := duckdns.NewDefaultConfig()
config.Token = token
return duckdns.NewDNSProviderConfig(config)
case "namesilo":
config := namesilo.NewDefaultConfig()
config.APIKey = token
return namesilo.NewDNSProviderConfig(config)
default:
return nil, ErrUnsupportedDNSProvider
}
}
// getPrivateKey reads the private key for the specified certificate id
func (s *Service) getPrivateKey(id uint64) (*rsa.PrivateKey, error) {
privKeyBytes, err := os.ReadFile(filepath.Join(s.keyDir, fmt.Sprintf("%d.key.pem", id)))
if err != nil {
return nil, err
}
return x509.ParsePKCS1PrivateKey(privKeyBytes)
}
// renewCert sets the renewing state in the database, calls renewCertInternal,
// updates the NotAfter/NotBefore columns in the database and writes the
// certificate to the certDir directory.
func (s *Service) renewCert(localData *localCertData) error {
// database synchronous state
s.setRenewing(localData.id, true, false)
// run internal renewal code and log errors
cert, certBytes, err := s.renewCertInternal(localData)
if err != nil {
s.setRenewing(localData.id, false, true)
return fmt.Errorf("failed to renew cert %d: %w", localData.id, err)
}
// set the NotAfter/NotBefore in the database
_, err = s.db.Exec(`UPDATE certificates SET renewing = 0, renew_failed = 0, not_after = ?, updated_at = ? WHERE id = ?`, cert.NotAfter, cert.NotBefore, localData.id)
if err != nil {
return fmt.Errorf("failed to update cert %d in database: %w", localData.id, err)
}
// write out the certificate file
err = s.writeCertFile(localData.id, certBytes)
if err != nil {
return fmt.Errorf("failed to write cert file: %w", err)
}
return nil
}
// renewCertInternal handles each stage of fetching the certificate private key,
// fetching the domains slice, setting up the lego client, obtaining a renewed
// certificate, decoding and parsing the certificate.
func (s *Service) renewCertInternal(localData *localCertData) (*x509.Certificate, []byte, error) {
// read private key file
privKey, err := s.getPrivateKey(localData.id)
if err != nil {
return nil, nil, fmt.Errorf("failed to open private key: %w", err)
}
// fetch domains for this certificate
domains, err := s.fetchDomains(localData)
if err != nil {
return nil, nil, fmt.Errorf("failed to update cert: %w", err)
}
// setup client for requesting a new certificate
client, err := s.setupLegoClient(localData)
if err != nil {
return nil, nil, fmt.Errorf("failed to generate a client: %w", err)
}
// obtain new certificate - this call will hang until a certificate is ready
obtain, err := client.Certificate.Obtain(certificate.ObtainRequest{
Domains: domains,
PrivateKey: privKey,
Bundle: true,
})
if err != nil {
return nil, nil, fmt.Errorf("failed to obtain replacement certificate: %w", err)
}
// extract the certificate data from pem encoding
p, _ := pem.Decode(obtain.Certificate)
if p.Type != "CERTIFICATE" {
return nil, nil, fmt.Errorf("invalid certificate type '%s'", p.Type)
}
// parse the obtained certificate
parseCert, err := x509.ParseCertificate(p.Bytes)
if err != nil {
return nil, nil, fmt.Errorf("failed to parse new certificate: %w", err)
}
// return the parsed and raw bytes
return parseCert, obtain.Certificate, nil
}
// setRenewing sets the renewing and failed states in the database for a
// specified certifcate id.
func (s *Service) setRenewing(id uint64, renewing, failed bool) {
_, err := s.db.Exec("UPDATE certificates SET renewing = ?, renew_failed = ? WHERE id = ?", renewing, failed, id)
if err != nil {
log.Printf("[Renewal] Failed to set renewing/failed mode in database %d: %s\n", id, err)
}
}
// writeCertFile writes the output certificate file and renames the current one
// to include `-old` in the name.
func (s *Service) writeCertFile(id uint64, certBytes []byte) error {
oldPath := filepath.Join(s.certDir, fmt.Sprintf("%d-old.cert.pem", id))
newPath := filepath.Join(s.certDir, fmt.Sprintf("%d.cert.pem", id))
// move certificate file to old name
err := os.Rename(newPath, oldPath)
if err != nil && !os.IsNotExist(err) {
return fmt.Errorf("failed to rename cert file '%s' => '%s': %w", newPath, oldPath, err)
}
// create new certificate file
openCertFile, err := os.Create(newPath)
if err != nil {
return fmt.Errorf("failed to create cert file '%s': %s", newPath, err)
}
defer openCertFile.Close()
// write certificate bytes
_, err = openCertFile.Write(certBytes)
if err != nil {
return fmt.Errorf("failed to write cert file '%s': %s", newPath, err)
}
return nil
}