package acme import ( "crypto" "crypto/rand" "crypto/rsa" "crypto/tls" "crypto/x509" "encoding/json" "errors" "fmt" log "github.com/Sirupsen/logrus" "github.com/xenolf/lego/acme" "io/ioutil" fmtlog "log" "os" "reflect" "sync" "time" ) // Account is used to store lets encrypt registration info type Account struct { Email string Registration *acme.RegistrationResource PrivateKey []byte DomainsCertificate DomainsCertificates } // GetEmail returns email func (a Account) GetEmail() string { return a.Email } // GetRegistration returns lets encrypt registration resource func (a Account) GetRegistration() *acme.RegistrationResource { return a.Registration } // GetPrivateKey returns private key func (a Account) GetPrivateKey() crypto.PrivateKey { if privateKey, err := x509.ParsePKCS1PrivateKey(a.PrivateKey); err == nil { return privateKey } log.Errorf("Cannot unmarshall private key %+v", a.PrivateKey) return nil } // Certificate is used to store certificate info type Certificate struct { Domain string CertURL string CertStableURL string PrivateKey []byte Certificate []byte } // DomainsCertificates stores a certificate for multiple domains type DomainsCertificates struct { Certs []*DomainsCertificate lock *sync.RWMutex } func (dc *DomainsCertificates) init() error { if dc.lock == nil { dc.lock = &sync.RWMutex{} } dc.lock.Lock() defer dc.lock.Unlock() for _, domainsCertificate := range dc.Certs { tlsCert, err := tls.X509KeyPair(domainsCertificate.Certificate.Certificate, domainsCertificate.Certificate.PrivateKey) if err != nil { return err } domainsCertificate.tlsCert = &tlsCert } return nil } func (dc *DomainsCertificates) renewCertificates(acmeCert *Certificate, domain Domain) error { dc.lock.Lock() defer dc.lock.Unlock() for _, domainsCertificate := range dc.Certs { if reflect.DeepEqual(domain, domainsCertificate.Domains) { domainsCertificate.Certificate = acmeCert tlsCert, err := tls.X509KeyPair(acmeCert.Certificate, acmeCert.PrivateKey) if err != nil { return err } domainsCertificate.tlsCert = &tlsCert return nil } } return errors.New("Certificate to renew not found for domain " + domain.Main) } func (dc *DomainsCertificates) addCertificateForDomains(acmeCert *Certificate, domain Domain) (*DomainsCertificate, error) { dc.lock.Lock() defer dc.lock.Unlock() tlsCert, err := tls.X509KeyPair(acmeCert.Certificate, acmeCert.PrivateKey) if err != nil { return nil, err } cert := DomainsCertificate{Domains: domain, Certificate: acmeCert, tlsCert: &tlsCert} dc.Certs = append(dc.Certs, &cert) return &cert, nil } func (dc *DomainsCertificates) getCertificateForDomain(domainToFind string) (*DomainsCertificate, bool) { dc.lock.RLock() defer dc.lock.RUnlock() for _, domainsCertificate := range dc.Certs { domains := []string{} domains = append(domains, domainsCertificate.Domains.Main) domains = append(domains, domainsCertificate.Domains.SANs...) for _, domain := range domains { if domain == domainToFind { return domainsCertificate, true } } } return nil, false } func (dc *DomainsCertificates) exists(domainToFind Domain) (*DomainsCertificate, bool) { dc.lock.RLock() defer dc.lock.RUnlock() for _, domainsCertificate := range dc.Certs { if reflect.DeepEqual(domainToFind, domainsCertificate.Domains) { return domainsCertificate, true } } return nil, false } // DomainsCertificate contains a certificate for multiple domains type DomainsCertificate struct { Domains Domain Certificate *Certificate tlsCert *tls.Certificate } func (dc *DomainsCertificate) needRenew() bool { for _, c := range dc.tlsCert.Certificate { crt, err := x509.ParseCertificate(c) if err != nil { // If there's an error, we assume the cert is broken, and needs update return true } // <= 7 days left, renew certificate if crt.NotAfter.Before(time.Now().Add(time.Duration(24 * 7 * time.Hour))) { return true } } return false } // ACME allows to connect to lets encrypt and retrieve certs type ACME struct { Email string Domains []Domain StorageFile string OnDemand bool CAServer string EntryPoint string storageLock sync.RWMutex } // Domain holds a domain name with SANs type Domain struct { Main string SANs []string } // CreateConfig creates a tls.config from using ACME configuration func (a *ACME) CreateConfig(tlsConfig *tls.Config, CheckOnDemandDomain func(domain string) bool) error { acme.Logger = fmtlog.New(ioutil.Discard, "", 0) if len(a.StorageFile) == 0 { return errors.New("Empty StorageFile, please provide a filenmae for certs storage") } log.Debugf("Generating default certificate...") if len(tlsConfig.Certificates) == 0 { // no certificates in TLS config, so we add a default one cert, err := generateDefaultCertificate() if err != nil { return err } tlsConfig.Certificates = append(tlsConfig.Certificates, *cert) } var account *Account var needRegister bool // if certificates in storage, load them if fileInfo, err := os.Stat(a.StorageFile); err == nil && fileInfo.Size() != 0 { log.Infof("Loading ACME certificates...") // load account account, err = a.loadAccount(a) if err != nil { return err } } else { log.Infof("Generating ACME Account...") // Create a user. New accounts need an email and private key to start privateKey, err := rsa.GenerateKey(rand.Reader, 4096) if err != nil { return err } account = &Account{ Email: a.Email, PrivateKey: x509.MarshalPKCS1PrivateKey(privateKey), } account.DomainsCertificate = DomainsCertificates{Certs: []*DomainsCertificate{}, lock: &sync.RWMutex{}} needRegister = true } client, err := a.buildACMEClient(account) if err != nil { return err } client.ExcludeChallenges([]acme.Challenge{acme.HTTP01, acme.DNS01}) wrapperChallengeProvider := newWrapperChallengeProvider() client.SetChallengeProvider(acme.TLSSNI01, wrapperChallengeProvider) if needRegister { // New users will need to register; be sure to save it reg, err := client.Register() if err != nil { return err } account.Registration = reg } // The client has a URL to the current Let's Encrypt Subscriber // Agreement. The user will need to agree to it. err = client.AgreeToTOS() if err != nil { return err } go a.retrieveCertificates(client, account) tlsConfig.GetCertificate = func(clientHello *tls.ClientHelloInfo) (*tls.Certificate, error) { if challengeCert, ok := wrapperChallengeProvider.getCertificate(clientHello.ServerName); ok { return challengeCert, nil } if domainCert, ok := account.DomainsCertificate.getCertificateForDomain(clientHello.ServerName); ok { return domainCert.tlsCert, nil } if a.OnDemand { if CheckOnDemandDomain != nil && !CheckOnDemandDomain(clientHello.ServerName) { return nil, nil } return a.loadCertificateOnDemand(client, account, clientHello) } return nil, nil } ticker := time.NewTicker(24 * time.Hour) go func() { for { select { case <-ticker.C: if err := a.renewCertificates(client, account); err != nil { log.Errorf("Error renewing ACME certificate %+v: %s", account, err.Error()) } } } }() return nil } func (a *ACME) retrieveCertificates(client *acme.Client, account *Account) { log.Infof("Retrieving ACME certificates...") for _, domain := range a.Domains { // check if cert isn't already loaded if _, exists := account.DomainsCertificate.exists(domain); !exists { domains := []string{} domains = append(domains, domain.Main) domains = append(domains, domain.SANs...) certificateResource, err := a.getDomainsCertificates(client, domains) if err != nil { log.Errorf("Error getting ACME certificate for domain %s: %s", domains, err.Error()) continue } _, err = account.DomainsCertificate.addCertificateForDomains(certificateResource, domain) if err != nil { log.Errorf("Error adding ACME certificate for domain %s: %s", domains, err.Error()) continue } if err = a.saveAccount(account); err != nil { log.Errorf("Error Saving ACME account %+v: %s", account, err.Error()) continue } } } log.Infof("Retrieved ACME certificates") } func (a *ACME) renewCertificates(client *acme.Client, account *Account) error { for _, certificateResource := range account.DomainsCertificate.Certs { if certificateResource.needRenew() { log.Debugf("Renewing certificate %+v", certificateResource.Domains) renewedCert, err := client.RenewCertificate(acme.CertificateResource{ Domain: certificateResource.Certificate.Domain, CertURL: certificateResource.Certificate.CertURL, CertStableURL: certificateResource.Certificate.CertStableURL, PrivateKey: certificateResource.Certificate.PrivateKey, Certificate: certificateResource.Certificate.Certificate, }, false) if err != nil { return err } log.Debugf("Renewed certificate %+v", certificateResource.Domains) renewedACMECert := &Certificate{ Domain: renewedCert.Domain, CertURL: renewedCert.CertURL, CertStableURL: renewedCert.CertStableURL, PrivateKey: renewedCert.PrivateKey, Certificate: renewedCert.Certificate, } err = account.DomainsCertificate.renewCertificates(renewedACMECert, certificateResource.Domains) if err != nil { return err } if err = a.saveAccount(account); err != nil { return err } } } return nil } func (a *ACME) buildACMEClient(Account *Account) (*acme.Client, error) { caServer := "https://acme-v01.api.letsencrypt.org/directory" if len(a.CAServer) > 0 { caServer = a.CAServer } client, err := acme.NewClient(caServer, Account, acme.RSA4096) if err != nil { return nil, err } return client, nil } func (a *ACME) loadCertificateOnDemand(client *acme.Client, Account *Account, clientHello *tls.ClientHelloInfo) (*tls.Certificate, error) { if certificateResource, ok := Account.DomainsCertificate.getCertificateForDomain(clientHello.ServerName); ok { return certificateResource.tlsCert, nil } Certificate, err := a.getDomainsCertificates(client, []string{clientHello.ServerName}) if err != nil { return nil, err } log.Debugf("Got certificate on demand for domain %s", clientHello.ServerName) cert, err := Account.DomainsCertificate.addCertificateForDomains(Certificate, Domain{Main: clientHello.ServerName}) if err != nil { return nil, err } if err = a.saveAccount(Account); err != nil { return nil, err } return cert.tlsCert, nil } func (a *ACME) loadAccount(acmeConfig *ACME) (*Account, error) { a.storageLock.RLock() defer a.storageLock.RUnlock() Account := Account{ DomainsCertificate: DomainsCertificates{}, } file, err := ioutil.ReadFile(acmeConfig.StorageFile) if err != nil { return nil, err } if err := json.Unmarshal(file, &Account); err != nil { return nil, err } err = Account.DomainsCertificate.init() if err != nil { return nil, err } log.Infof("Loaded ACME config from storage %s", acmeConfig.StorageFile) return &Account, nil } func (a *ACME) saveAccount(Account *Account) error { a.storageLock.Lock() defer a.storageLock.Unlock() // write account to file data, err := json.MarshalIndent(Account, "", " ") if err != nil { return err } return ioutil.WriteFile(a.StorageFile, data, 0644) } func (a *ACME) getDomainsCertificates(client *acme.Client, domains []string) (*Certificate, error) { log.Debugf("Loading ACME certificates %s...", domains) bundle := false certificate, failures := client.ObtainCertificate(domains, bundle, nil) if len(failures) > 0 { log.Error(failures) return nil, fmt.Errorf("Cannot obtain certificates %s+v", failures) } log.Debugf("Loaded ACME certificates %s", domains) return &Certificate{ Domain: certificate.Domain, CertURL: certificate.CertURL, CertStableURL: certificate.CertStableURL, PrivateKey: certificate.PrivateKey, Certificate: certificate.Certificate, }, nil }