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
}
// If cert/key files are specified, and found, use them.
// If cert/key files are specified, not found, and the default values, generate
// them (self-signed CA used as a cert), and use them.
// If cert/key files are not specified, use Let's Encrypt.
func setupTLS(ws *webserver.Server, config *serverinit.Config, hostname string) {
cert, key := config.OptionalString("httpsCert", ""), config.OptionalString("httpsKey", "")
if !config.OptionalBool("https", true) {
return
}
if (cert != "") != (key != "") {
exitf("httpsCert and httpsKey must both be either present or absent")
}
defCert := osutil.DefaultTLSCert()
defKey := osutil.DefaultTLSKey()
const hint = "You must add this certificate's fingerprint to your client's trusted certs list to use it. Like so:\n\"trustedCerts\": [\"%s\"],"
if cert == defCert && key == defKey {
_, err1 := wkfs.Stat(cert)
_, err2 := wkfs.Stat(key)
if err1 != nil || err2 != nil {
if os.IsNotExist(err1) || os.IsNotExist(err2) {
sig, err := httputil.GenSelfTLSFiles(hostname, defCert, defKey)
if err != nil {
exitf("Could not generate self-signed TLS cert: %q", err)
}
log.Printf(hint, sig)
} else {
exitf("Could not stat cert or key: %q, %q", err1, err2)
}
}
}
if cert == "" && key == "" {
// Use Let's Encrypt if no files are specified, and we have a usable hostname.
if netutil.IsFQDN(hostname) {
m := autocert.Manager{
Prompt: autocert.AcceptTOS,
HostPolicy: autocert.HostWhitelist(hostname),
Cache: autocert.DirCache(osutil.DefaultLetsEncryptCache()),
}
log.Print("TLS enabled, with Let's Encrypt")
ws.SetTLS(webserver.TLSSetup{
CertManager: m.GetCertificate,
})
return
}
// Otherwise generate new certificates
sig, err := httputil.GenSelfTLSFiles(hostname, defCert, defKey)
if err != nil {
exitf("Could not generate self signed creds: %q", err)
}
log.Printf(hint, sig)
cert = defCert
key = defKey
}
data, err := wkfs.ReadFile(cert)
if err != nil {
exitf("Failed to read pem certificate: %s", err)
}
sig, err := httputil.CertFingerprint(data)
if err != nil {
exitf("certificate error: %v", err)
}
log.Printf("TLS enabled, with SHA-256 certificate fingerprint: %v", sig)
ws.SetTLS(webserver.TLSSetup{
CertFile: cert,
KeyFile: key,
})
}