From b5b6bba5e405bb62e080596e3d2e8cb6f1f7cca1 Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Mon, 19 Oct 2020 17:27:29 +0200
Subject: [PATCH] Add "tls load" frontend directive

---
 directives.go   | 36 +++++++++++++++++++++++++++++++++++-
 server.go       | 19 ++++++++++++++-----
 tlstunnel.1.scd | 11 ++++++++++-
 3 files changed, 59 insertions(+), 7 deletions(-)

diff --git a/directives.go b/directives.go
index f9308c4..83730d1 100644
--- a/directives.go
+++ b/directives.go
@@ -1,6 +1,7 @@
 package tlstunnel
 
 import (
+	"crypto/tls"
 	"fmt"
 	"net"
 	"net/url"
@@ -40,13 +41,23 @@ func parseFrontend(srv *Server, d *scfg.Directive) error {
 		return err
 	}
 
+	unmanaged := false
+	tlsDirective := d.Children.Get("tls")
+	if tlsDirective != nil {
+		var err error
+		unmanaged, err = parseFrontendTLS(srv, tlsDirective)
+		if err != nil {
+			return err
+		}
+	}
+
 	for _, addr := range d.Params {
 		host, port, err := net.SplitHostPort(addr)
 		if err != nil {
 			return fmt.Errorf("failed to parse frontend address %q: %v", addr, err)
 		}
 
-		if host != "" {
+		if host != "" && !unmanaged {
 			srv.ManagedNames = append(srv.ManagedNames, host)
 		}
 
@@ -96,6 +107,29 @@ func parseBackend(backend *Backend, d *scfg.Directive) error {
 	return nil
 }
 
+func parseFrontendTLS(srv *Server, d *scfg.Directive) (unmanaged bool, err error) {
+	for _, child := range d.Children {
+		switch child.Name {
+		case "load":
+			var certPath, keyPath string
+			if err := child.ParseParams(&certPath, &keyPath); err != nil {
+				return false, err
+			}
+
+			cert, err := tls.LoadX509KeyPair(certPath, keyPath)
+			if err != nil {
+				return false, fmt.Errorf("directive \"load\": %v", err)
+			}
+
+			srv.UnmanagedCerts = append(srv.UnmanagedCerts, cert)
+			unmanaged = true
+		default:
+			return false, fmt.Errorf("unknown %q directive", child.Name)
+		}
+	}
+	return unmanaged, nil
+}
+
 func parseTLS(srv *Server, d *scfg.Directive) error {
 	for _, child := range d.Children {
 		switch child.Name {
diff --git a/server.go b/server.go
index b9c3a0d..21154a7 100644
--- a/server.go
+++ b/server.go
@@ -16,11 +16,14 @@ import (
 )
 
 type Server struct {
-	Listeners    map[string]*Listener // indexed by listening address
-	Frontends    []*Frontend
-	ManagedNames []string
-	ACMEManager  *certmagic.ACMEManager
-	ACMEConfig   *certmagic.Config
+	Listeners map[string]*Listener // indexed by listening address
+	Frontends []*Frontend
+
+	ManagedNames   []string
+	UnmanagedCerts []tls.Certificate
+
+	ACMEManager *certmagic.ACMEManager
+	ACMEConfig  *certmagic.Config
 }
 
 func NewServer() *Server {
@@ -55,6 +58,12 @@ func (srv *Server) RegisterListener(addr string) *Listener {
 }
 
 func (srv *Server) Start() error {
+	for _, cert := range srv.UnmanagedCerts {
+		if err := srv.ACMEConfig.CacheUnmanagedTLSCertificate(cert, nil); err != nil {
+			return err
+		}
+	}
+
 	if err := srv.ACMEConfig.ManageAsync(context.Background(), srv.ManagedNames); err != nil {
 		return fmt.Errorf("failed to manage TLS certificates: %v", err)
 	}
diff --git a/tlstunnel.1.scd b/tlstunnel.1.scd
index ae781ec..0107577 100644
--- a/tlstunnel.1.scd
+++ b/tlstunnel.1.scd
@@ -55,9 +55,18 @@ The following directives are supported:
 		The _+proxy_ suffix can be added to the URI scheme to forward
 		connection metadata via the PROXY protocol.
 
+	*tls* { ... }
+		Customise frontend-specific TLS configuration.
+
+		The tls directive supports the following sub-directives:
+
+		*load* <cert> <key>
+			Load certificates and private keys from PEM files.
+
+			This disables automatic TLS.
 
 *tls* { ... }
-	Customise TLS configuration.
+	Customise global TLS configuration.
 
 	The tls directive supports the following sub-directives: