traefik/acme.go
Emile Vauge 6e484e5c2d
add let's encrypt support
Signed-off-by: Emile Vauge <emile@vauge.com>
2016-03-21 20:15:28 +01:00

337 lines
10 KiB
Go

/*
Copyright
*/
package main
import (
"crypto"
"crypto/rand"
"crypto/rsa"
"crypto/tls"
"crypto/x509"
"encoding/json"
"errors"
"fmt"
log "github.com/Sirupsen/logrus"
"github.com/containous/traefik/middlewares"
"github.com/gorilla/mux"
"github.com/xenolf/lego/acme"
"io/ioutil"
fmtlog "log"
"net"
"net/http"
"net/http/httputil"
"net/url"
"os"
"time"
)
// ACMEAccount is used to store lets encrypt registration info
type ACMEAccount struct {
Email string
Registration *acme.RegistrationResource
PrivateKey []byte
CertificatesMap DomainsCertificates
}
// DomainsCertificates stores a certificate for multiple domains
type DomainsCertificates []DomainsCertificate
func (dc DomainsCertificates) getCertificateForDomain(domainToFind string) (*AcmeCertificate, bool) {
for _, domainsCertificate := range dc {
for _, domain := range domainsCertificate.Domains {
if domain == domainToFind {
return domainsCertificate.Certificate, true
}
}
}
return nil, false
}
// DomainsCertificate contains a certificate for multiple domains
type DomainsCertificate struct {
Domains []string
Certificate *AcmeCertificate
}
// GetEmail returns email
func (a ACMEAccount) GetEmail() string {
return a.Email
}
// GetRegistration returns lets encrypt registration resource
func (a ACMEAccount) GetRegistration() *acme.RegistrationResource {
return a.Registration
}
// GetPrivateKey returns private key
func (a ACMEAccount) 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
}
// AcmeCertificate is used to store certificate info
type AcmeCertificate struct {
Domain string
CertURL string
CertStableURL string
PrivateKey []byte
Certificate []byte
}
func (a *ACME) createACMEConfig(router *middlewares.HandlerSwitcher, proxyRouter *middlewares.HandlerSwitcher) (*tls.Config, error) {
acme.Logger = fmtlog.New(ioutil.Discard, "", 0)
if len(a.StorageFile) == 0 {
return nil, errors.New("Empty StorageFile, please provide a filenmae for certs storage")
}
// if certificates in storage, load them
if fileInfo, err := os.Stat(a.StorageFile); err == nil && fileInfo.Size() != 0 {
// load account
acmeAccount, err := a.loadACMEAccount(a)
if err != nil {
return nil, err
}
// build client
client, err := a.buildACMEClient(acmeAccount)
if err != nil {
return nil, err
}
config := &tls.Config{}
config.Certificates = []tls.Certificate{}
for _, certificateResource := range acmeAccount.CertificatesMap {
cert, err := tls.X509KeyPair(certificateResource.Certificate.Certificate, certificateResource.Certificate.PrivateKey)
if err != nil {
return nil, err
}
leaf, err := x509.ParseCertificate(cert.Certificate[0])
if err != nil {
return nil, err
}
// <= 30 days left, renew certificate
if leaf.NotAfter.Before(time.Now().Add(time.Duration(24 * 30 * time.Hour))) {
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 nil, err
}
log.Debugf("Renewed certificate %s", renewedCert.Domain)
certificateResource.Certificate = &AcmeCertificate{
Domain: renewedCert.Domain,
CertURL: renewedCert.CertURL,
CertStableURL: renewedCert.CertStableURL,
PrivateKey: renewedCert.PrivateKey,
Certificate: renewedCert.Certificate,
}
if err = a.saveACMEAccount(acmeAccount); err != nil {
return nil, err
}
cert, err = tls.X509KeyPair(renewedCert.Certificate, renewedCert.PrivateKey)
if err != nil {
return nil, err
}
}
config.Certificates = append(config.Certificates, cert)
}
config.BuildNameToCertificate()
if a.OnDemand {
config.GetCertificate = func(clientHello *tls.ClientHelloInfo) (*tls.Certificate, error) {
if !router.GetHandler().Match(&http.Request{URL: &url.URL{}, Host: clientHello.ServerName}, &mux.RouteMatch{}) {
return nil, nil
}
return a.loadCertificateOnDemand(client, acmeAccount, clientHello, proxyRouter)
}
}
return config, nil
}
log.Infof("Loading ACME certificates...")
// Create a user. New accounts need an email and private key to start
privateKey, err := rsa.GenerateKey(rand.Reader, 4096)
if err != nil {
return nil, err
}
acmeAccount := &ACMEAccount{
Email: a.Email,
PrivateKey: x509.MarshalPKCS1PrivateKey(privateKey),
}
client, err := a.buildACMEClient(acmeAccount)
if err != nil {
return nil, err
}
//client.SetTLSAddress(acmeConfig.TLSAddress)
// New users will need to register; be sure to save it
reg, err := client.Register()
if err != nil {
return nil, err
}
acmeAccount.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 nil, err
}
config := &tls.Config{}
config.Certificates = []tls.Certificate{}
acmeAccount.CertificatesMap = []DomainsCertificate{}
for _, domain := range a.Domains {
domains := append([]string{domain.Main}, domain.SANs...)
certificateResource, err := a.getDomainsCertificates(client, domains, proxyRouter)
if err != nil {
return nil, err
}
cert, err := tls.X509KeyPair(certificateResource.Certificate, certificateResource.PrivateKey)
if err != nil {
return nil, err
}
config.Certificates = append(config.Certificates, cert)
acmeAccount.CertificatesMap = append(acmeAccount.CertificatesMap, DomainsCertificate{Domains: domains, Certificate: certificateResource})
}
// BuildNameToCertificate parses the CommonName and SubjectAlternateName fields
// in each certificate and populates the config.NameToCertificate map.
config.BuildNameToCertificate()
if a.OnDemand {
config.GetCertificate = func(clientHello *tls.ClientHelloInfo) (*tls.Certificate, error) {
if !router.GetHandler().Match(&http.Request{URL: &url.URL{}, Host: clientHello.ServerName}, &mux.RouteMatch{}) {
return nil, nil
}
return a.loadCertificateOnDemand(client, acmeAccount, clientHello, proxyRouter)
}
}
if err = a.saveACMEAccount(acmeAccount); err != nil {
return nil, err
}
return config, nil
}
func (a *ACME) buildACMEClient(acmeAccount *ACMEAccount) (*acme.Client, error) {
// A client facilitates communication with the CA server. This CA URL is
// configured for a local dev instance of Boulder running in Docker in a VM.
caServer := "https://acme-v01.api.letsencrypt.org/directory"
if len(a.CAServer) > 0 {
caServer = a.CAServer
}
client, err := acme.NewClient(caServer, acmeAccount, acme.RSA4096)
if err != nil {
return nil, err
}
return client, nil
}
// Ask the kernel for a free open port that is ready to use
func (a *ACME) getFreePort() (string, error) {
addr, err := net.ResolveTCPAddr("tcp", "127.0.0.1:0")
if err != nil {
return "", err
}
l, err := net.ListenTCP("tcp", addr)
if err != nil {
return "", err
}
defer l.Close()
return l.Addr().String(), nil
}
func (a *ACME) loadCertificateOnDemand(client *acme.Client, acmeAccount *ACMEAccount, clientHello *tls.ClientHelloInfo, proxyRouter *middlewares.HandlerSwitcher) (*tls.Certificate, error) {
if certificateResource, ok := acmeAccount.CertificatesMap.getCertificateForDomain(clientHello.ServerName); ok {
cert, err := tls.X509KeyPair(certificateResource.Certificate, certificateResource.PrivateKey)
if err != nil {
return nil, err
}
return &cert, nil
}
certificateResource, err := a.getDomainsCertificates(client, []string{clientHello.ServerName}, proxyRouter)
if err != nil {
return nil, err
}
log.Debugf("Got certificate on demand for domain %s", clientHello.ServerName)
acmeAccount.CertificatesMap = append(acmeAccount.CertificatesMap, DomainsCertificate{Domains: []string{clientHello.ServerName}, Certificate: certificateResource})
if err = a.saveACMEAccount(acmeAccount); err != nil {
return nil, err
}
cert, err := tls.X509KeyPair(certificateResource.Certificate, certificateResource.PrivateKey)
if err != nil {
return nil, err
}
return &cert, nil
}
func (a *ACME) loadACMEAccount(acmeConfig *ACME) (*ACMEAccount, error) {
a.storageLock.Lock()
defer a.storageLock.Unlock()
acmeAccount := ACMEAccount{
CertificatesMap: DomainsCertificates{},
}
file, err := ioutil.ReadFile(acmeConfig.StorageFile)
if err != nil {
return nil, err
}
if err := json.Unmarshal(file, &acmeAccount); err != nil {
return nil, err
}
log.Infof("Loaded ACME config from storage %s", acmeConfig.StorageFile)
return &acmeAccount, nil
}
func (a *ACME) saveACMEAccount(acmeAccount *ACMEAccount) error {
a.storageLock.Lock()
defer a.storageLock.Unlock()
// write account to file
data, err := json.MarshalIndent(acmeAccount, "", " ")
if err != nil {
return err
}
return ioutil.WriteFile(a.StorageFile, data, 0644)
}
func (a *ACME) getDomainsCertificates(client *acme.Client, domains []string, proxyRouter *middlewares.HandlerSwitcher) (*AcmeCertificate, error) {
var proxyRoute *mux.Route
proxyRoute = proxyRouter.GetHandler().Get("9141156b44763db2a504b8c63cf6f81c")
if proxyRoute == nil {
proxyRoute = proxyRouter.GetHandler().NewRoute().PathPrefix("/.well-known/acme-challenge/").Name("9141156b44763db2a504b8c63cf6f81c")
}
url, err := url.Parse("http://127.0.0.1:5002")
if err != nil {
return nil, err
}
reverseProxy := httputil.NewSingleHostReverseProxy(url)
proxyRoute.Handler(reverseProxy)
defer proxyRoute.Handler(http.NotFoundHandler())
// The acme library takes care of completing the challenges to obtain the certificate(s).
// Of course, the hostnames must resolve to this machine or it will fail.
log.Debugf("Loading ACME certificates %s", domains)
bundle := false
client.ExcludeChallenges([]acme.Challenge{acme.TLSSNI01, acme.DNS01})
client.SetHTTPAddress("127.0.0.1:5002")
certificate, failures := client.ObtainCertificate(domains, bundle, nil)
if len(failures) > 0 {
log.Error(failures)
return nil, fmt.Errorf("Cannot obtain certificates %s+v", failures)
}
return &AcmeCertificate{
Domain: certificate.Domain,
CertURL: certificate.CertURL,
CertStableURL: certificate.CertStableURL,
PrivateKey: certificate.PrivateKey,
Certificate: certificate.Certificate,
}, nil
}