func setupTLS(ws *webserver.Server, conf *config) error {
if conf.HTTPSCert != "" && conf.HTTPSKey != "" {
ws.SetTLS(webserver.TLSSetup{
CertFile: conf.HTTPSCert,
KeyFile: conf.HTTPSKey,
})
return nil
}
if !conf.CertManager {
return nil
}
// As all requests to the publisher are proxied through Camlistore's app
// handler, it makes sense to assume that both Camlistore and the publisher
// are behind the same domain name. Therefore, it follows that
// camlistored's autocert is the one actually getting a cert (and answering
// the challenge) for the both of them. Plus, if they run on the same host
// (default setup), they can't both listen on 443 to answer the TLS-SNI
// challenge.
// TODO(mpl): however, camlistored and publisher could be running on
// different hosts, in which case we need to find a way for camlistored to
// share its autocert cache with publisher. But I think that can wait a
// later CL.
hostname := os.Getenv("CAMLI_API_HOST")
hostname = strings.TrimPrefix(hostname, "https://")
hostname = strings.SplitN(hostname, "/", 2)[0]
hostname = strings.SplitN(hostname, ":", 2)[0]
if !netutil.IsFQDN(hostname) {
return fmt.Errorf("cannot ask Let's Encrypt for a cert because %v is not a fully qualified domain name", hostname)
}
logger.Print("TLS enabled, with Let's Encrypt")
// TODO(mpl): we only want publisher to use the same cache as
// camlistored, and we don't actually need an autocert.Manager.
// So we could just instantiate an autocert.DirCache, and generate
// from there a *tls.Certificate, but it looks like it would mean
// extracting quite a bit of code from the autocert pkg to do it properly.
// Instead, I've opted for using an autocert.Manager (even though it's
// never going to reply to any challenge), but with NOOP for Put and
// Delete, just to be on the safe side. It's simple enough, but there's
// still a catch: there's no ServerName in the clientHello we get, so we
// reinject one so we can simply use the autocert.Manager.GetCertificate
// method as the way to get the certificate from the cache. Is that OK?
m := autocert.Manager{
Prompt: autocert.AcceptTOS,
HostPolicy: autocert.HostWhitelist(hostname),
Cache: roCertCacheDir(osutil.DefaultLetsEncryptCache()),
}
ws.SetTLS(webserver.TLSSetup{
CertManager: func(clientHello *tls.ClientHelloInfo) (*tls.Certificate, error) {
if clientHello.ServerName == "" {
clientHello.ServerName = hostname
}
return m.GetCertificate(clientHello)
},
})
return nil
}
func (srv *Server) newTLSConfig(cfg ServerConfig) *tls.Config {
tlsConfig := utils.SecureTLSConfig()
if cfg.AutocertDNSName == "" {
// No official DNS name, no certificate.
tlsConfig.GetCertificate = func(clientHello *tls.ClientHelloInfo) (*tls.Certificate, error) {
cert, _ := srv.localCertificate(clientHello.ServerName)
return cert, nil
}
return tlsConfig
}
m := autocert.Manager{
Prompt: autocert.AcceptTOS,
Cache: srv.state.AutocertCache(),
HostPolicy: autocert.HostWhitelist(cfg.AutocertDNSName),
}
if cfg.AutocertURL != "" {
m.Client = &acme.Client{
DirectoryURL: cfg.AutocertURL,
}
}
tlsConfig.GetCertificate = func(clientHello *tls.ClientHelloInfo) (*tls.Certificate, error) {
logger.Infof("getting certificate for server name %q", clientHello.ServerName)
// Get the locally created certificate and whether it's appropriate
// for the SNI name. If not, we'll try to get an acme cert and
// fall back to the local certificate if that fails.
cert, shouldUse := srv.localCertificate(clientHello.ServerName)
if shouldUse {
return cert, nil
}
acmeCert, err := m.GetCertificate(clientHello)
if err == nil {
return acmeCert, nil
}
logger.Errorf("cannot get autocert certificate for %q: %v", clientHello.ServerName, err)
return cert, nil
}
return tlsConfig
}