validator: integrate validator-config for data validation

Change-Id: I782964f8d6ce9134b2b849425a13b82aef741e2f
refs #1479
diff --git a/repo-ng.conf.sample b/repo-ng.conf.sample
index 31a508e..aa4a6b3 100644
--- a/repo-ng.conf.sample
+++ b/repo-ng.conf.sample
@@ -34,8 +34,8 @@
 
   validator
   {
-    ; This rule is just an example of validation of signed interests for commands.
-    ; User could define its own rule for signed command interest or data to be inserted
+    ; These rule is just an example of validation of signed interests for commands and data.
+    ; User could define its own rule for signed interest or data to be inserted
     ; according to Validator Configuration File Format.
     ; (http://redmine.named-data.net/projects/ndn-cxx/wiki/CommandValidatorConf)
     rule
@@ -62,5 +62,30 @@
         }
       }
     }
+
+    rule
+    {
+      id "Simple Rule For Data"
+      for data
+      filter
+      {
+        type name
+        name /example/data/1
+        relation is-prefix-of
+      }
+      checker
+      {
+        type fixed-signer
+        sig-type rsa-sha256
+        signer
+        {
+          type file
+          ; repo-ng.cert.sample is just a non-existent certificate.
+          ; User should create its own certification using Security Tool.
+          ; (http://redmine.named-data.net/projects/ndn-cxx/wiki/SecurityTools)
+          file-name "repo-ng.cert.sample"
+        }
+      }
+    }
   }
 }
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