Add TLS support

Fixes #20.

Change-Id: I9c6b4ff3195f05e8a3c17d6704ee06b1f77db562

cmd/vaind/main.go

@@ -55,6 +55,9 @@ const usage = "vaind [init] <dbname>"
 
 type config struct {
 	Port int
+
+	Cert string
+	Key  string
 }
 
 func main() {
@@ -114,8 +117,17 @@ func main() {
 	sm := http.NewServeMux()
 	vain.NewServer(sm, db)
 	addr := fmt.Sprintf(":%d", c.Port)
+
+	if c.Cert == "" || c.Key == "" {
+		log.Printf("INSECURE MODE")
 		if err := http.ListenAndServe(addr, sm); err != nil {
 			log.Printf("problem with http server: %v", err)
 			os.Exit(1)
 		}
+	} else {
+		if err := http.ListenAndServeTLS(addr, c.Cert, c.Key, sm); err != nil {
+			log.Printf("problem with http server: %v", err)
+			os.Exit(1)
+		}
+	}
 }

server.go

@@ -130,7 +130,11 @@ func (s *Server) register(w http.ResponseWriter, req *http.Request) {
 		http.Error(w, err.Message, err.Code)
 		return
 	}
-	log.Printf("http://%s/api/v0/confirm/%+v", req.Host, tok)
+	proto := "https"
+	if req.TLS == nil {
+		proto = "http"
+	}
+	log.Printf("%s://%s/api/v0/confirm/%+v", proto, req.Host, tok)
 	fmt.Fprintf(w, "please check your email\n")
 }