replace ad-hoc response handler with Util.response

lib/check-signature.js

@@ -9,39 +9,43 @@ const Nacl = require('tweetnacl/nacl-fast');
 console.log('New child process', process.pid);
 
 process.on('message', function (data) {
-    console.log('In process', process.pid);
-    console.log(+new Date(), "Message received by subprocess");
+    //console.log('In process', process.pid);
+    //console.log(+new Date(), "Message received by subprocess");
     if (!data || !data.key || !data.msg || !data.txid) {
-        process.send({
+        return void process.send({
             error:'E_INVAL'
         });
-        return;
     }
     const txid = data.txid;
 
-    const signedMsg = Nacl.util.decodeBase64(data.msg);
+    var signedMsg;
+    try {
+        signedMsg = Nacl.util.decodeBase64(data.msg);
+    } catch (e) {
+        return void process.send({
+            txid: txid,
+            error: 'E_BAD_MESSAGE',
+        });
+    }
+
     var validateKey;
     try {
         validateKey = Nacl.util.decodeBase64(data.key);
     } catch (e) {
-        process.send({
+        return void process.send({
             txid: txid,
             error:'E_BADKEY'
         });
-        return;
     }
     // validate the message
     const validated = Nacl.sign.open(signedMsg, validateKey);
     if (!validated) {
-        process.send({
+        return void process.send({
             txid: txid,
             error:'FAILED'
         });
-        return;
     }
-    console.log(+new Date(), "Verification done in the subprocess");
     process.send({
         txid: txid,
-        success: true
     });
 });