tools: add certification check

If the server disable the anonymous connection option, it accept a client only if the CA of the client matches the CA of the server.
Else (anonymous connection option enabled), the server accept any request.

Change-Id: I6ff6ec72d6f6452ce50fd8aa35896ff7117be6c0
diff --git a/tools/dsh/dsh.yaml b/tools/dsh/dsh.yaml
index 54e13ab..a023aa3 100644
--- a/tools/dsh/dsh.yaml
+++ b/tools/dsh/dsh.yaml
@@ -6,3 +6,4 @@
 turn_realm: "ring"
 binary: "bash"
 CA: HOME/.dhtnet # Change this to the path of the CA directory
+anonymous: false