added ua comment validator

install/generator-cyphernode/generators/app/index.js

@@ -8,6 +8,8 @@ const path = require("path");
 const featureChoices = require(path.join(__dirname, "features.json"));
 const coinstring = require('coinstring');
 
+const uaCommentRegexp = /^[a-zA-Z0-9 \.,:_\?@]+$/
+
 let prompters = [];
 const normalizedPath = path.join(__dirname, "prompters");
 fs.readdirSync(normalizedPath).forEach(function(file) {
@@ -128,6 +130,13 @@ module.exports = class extends Generator {
     return true;
   }
 
+  _UACommentValidator( comment ) {
+    if( !uaCommentRegexp.test( comment ) ) {
+      throw new Error('Unsafe characters in UA comment. Please use only a-z, A-Z, 0-9, SPACE and .,:_?@');
+    }
+    return true;
+  }
+
   _trimFilter( input ) {
     return (input+"").trim();
   }

install/generator-cyphernode/generators/app/prompters/100_bitcoin.js

@@ -73,6 +73,7 @@ module.exports = {
       name: 'bitcoin_uacomment',
       default: utils._getDefault( 'bitcoin_uacomment' ),
       message: prefix()+'Any UA comment?'+'\n',
+      validate: utils._UACommentValidator
     }];
   },
   env: function( props ) {