js: Making objects inmutable

--

* An Object.freeze should stop any malicious third party from changing
  objects' methods once the objects are instantiated (see unittest for
  an approach that would have worked before)
  - An initialized gpgmejs- object doesn't have a '_Keyring' property
    anymore (it still has its 'Keyring')
  - The internal expect='base64' needed to be turned into a method.

1 files changed, 12 insertions, 2 deletions

diff --git a/lang/js/src/Message.js b/lang/js/src/Message.js
index c0b6ed57..e2c07344 100644
--- a/lang/js/src/Message.js
+++ b/lang/js/src/Message.js
@@ -36,7 +36,7 @@ export function createMessage(operation){
         return gpgme_error('PARAM_WRONG');
     }
     if (permittedOperations.hasOwnProperty(operation)){
-        return new GPGME_Message(operation);
+        return Object.freeze(new GPGME_Message(operation));
     } else {
         return gpgme_error('MSG_WRONG_OP');
     }
@@ -56,11 +56,21 @@ export class GPGME_Message {
             op: operation,
             chunksize: 1023* 1024
         };
+        let expected = null;
 
         this.getOperation = function(){
             return _msg.op;
         };
 
+        this.setExpect = function(value){
+            if (value === 'base64'){
+                expected = value;
+            }
+        };
+        this.getExpect = function(){
+            return expected;
+        };
+
         /**
          * The maximum size of responses from gpgme in bytes. As of July 2018,
          * most browsers will only accept answers up to 1 MB of size.
@@ -204,7 +214,7 @@ export class GPGME_Message {
             return new Promise(function(resolve, reject) {
                 if (me.isComplete() === true) {
 
-                    let conn  = new Connection;
+                    let conn  = Object.freeze(new Connection);
                     conn.post(me).then(function(response) {
                         resolve(response);
                     }, function(reason) {