From 1b7b6418f1a499c74e66884e0b82d5fe8976657a Mon Sep 17 00:00:00 2001
From: Frank Denis <github@pureftpd.org>
Date: Sun, 14 Jan 2018 00:08:46 +0100
Subject: [PATCH] Restrict the set of resolvers used from a remote source

---
 dnscrypt-proxy/config.go           | 20 ++++++++++++++++++--
 dnscrypt-proxy/dnscrypt-proxy.toml |  2 +-
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/dnscrypt-proxy/config.go b/dnscrypt-proxy/config.go
index 972136e3..ac538e71 100644
--- a/dnscrypt-proxy/config.go
+++ b/dnscrypt-proxy/config.go
@@ -4,6 +4,7 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"strings"
 	"time"
 
 	"github.com/BurntSushi/toml"
@@ -112,12 +113,18 @@ func ConfigLoad(proxy *Proxy, config_file string) error {
 			dlog.Criticalf("Unable use source [%s]: [%s]", sourceName, err)
 			continue
 		}
-		proxy.registeredServers = append(proxy.registeredServers, registeredServers...)
+		for _, registeredServer := range registeredServers {
+			if !includesName(config.ServerNames, registeredServer.name) {
+				continue
+			}
+			dlog.Infof("Adding [%s] to the set of wanted resolvers", registeredServer.name)
+			proxy.registeredServers = append(proxy.registeredServers, registeredServer)
+		}
 	}
 	for _, serverName := range config.ServerNames {
 		serverConfig, ok := config.ServersConfig[serverName]
 		if !ok {
-			return fmt.Errorf("No definitions found for server [%v]", serverName)
+			continue
 		}
 		var stamp ServerStamp
 		var err error
@@ -137,3 +144,12 @@ func ConfigLoad(proxy *Proxy, config_file string) error {
 	}
 	return nil
 }
+
+func includesName(names []string, name string) bool {
+	for _, found := range names {
+		if strings.EqualFold(found, name) {
+			return true
+		}
+	}
+	return false
+}
diff --git a/dnscrypt-proxy/dnscrypt-proxy.toml b/dnscrypt-proxy/dnscrypt-proxy.toml
index a0accccd..0336568b 100644
--- a/dnscrypt-proxy/dnscrypt-proxy.toml
+++ b/dnscrypt-proxy/dnscrypt-proxy.toml
@@ -11,7 +11,7 @@
 ## List of servers to use
 ## If this line is commented, all registered servers will be used
 
-server_names = ["dnscrypt.org-fr"]
+server_names = ["dnscrypt.org-fr", "adguard-dns"]
 
 
 ## List of local addresses and ports to listen to. Can be IPv4 and/or IPv6.