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, 16 insertions, 0 deletions

diff --git a/lang/js/unittests.js b/lang/js/unittests.js
index 6228993b..3304b1eb 100644
--- a/lang/js/unittests.js
+++ b/lang/js/unittests.js
@@ -253,6 +253,22 @@ function unittests (){
                 expect(key.fingerprint.code).to.equal('KEY_INVALID');
             }
         });
+
+        it('Overwriting getFingerprint does not work', function(){
+            const evilFunction = function(){
+                return 'bad Data';
+            };
+            let key = createKey(kp.validKeyFingerprint, true);
+            expect(key.fingerprint).to.equal(kp.validKeyFingerprint);
+            try {
+                key.getFingerprint = evilFunction;
+            }
+            catch(e) {
+                expect(e).to.be.an.instanceof(TypeError);
+            }
+            expect(key.fingerprint).to.equal(kp.validKeyFingerprint);
+            expect(key.getFingerprint).to.not.equal(evilFunction);
+        });
         // TODO: tests for subkeys
         // TODO: tests for userids
         // TODO: some invalid tests for key/keyring