What is wrong with crypto.getRandomValues in Internet Explorer 11?

Question

The following code generates 3 random numbers by using window.crypto.getRandomValues. According to the developer's documentation (Microsoft MSDN and Mozilla MDN), this should work both in IE and in Chrome.

But in reality it works only in Chrome, not Internet Explorer 11. According to Microsoft, this code should work - they have given a similar code sample as the one listed below (see MSDN link above).

What is wrong? And how can it be fixed so it will work in both browsers?

var randomValuesArray = new Int32Array(3);
var crypto = window.crypto;
crypto.getRandomValues(randomValuesArray);

var outputString = "";
for (var i = 0; i < randomValuesArray.length; i++) {
  if (i > 0) outputString += ",";
  outputString += randomValuesArray[i];
}
console.log(outputString);

Try this snippet in Chrome first, there it shows correctly something like

-513632982,-694446670,-254182938

as log text.

Then, copy this question's URL and try it in Internet Explorer 11 - there it is showing:

Error: { "message": "Unable to get property 'getRandomValues' of undefined or null >reference", "filename": "https://stacksnippets.net/js", "lineno": 15, "colno": 2 }

or

Error: { "message": "Script error.", "filename": "https://stacksnippets.net/js", "lineno": 0, "colno": 0 }

---

Some background: While trying out this code to generate Guids in Javascript, I found the issue described in this question.

---

Updates:

• According to James Thorpe's excellent answer below, I fixed the Guids in JavaScript source code.
• Newer browsers from Microsoft like Edge Version 96.0.1054.43 don't show this issue any more. But it is still good to use the answer provided below to maintain best possible compatibility.

Alverson

Don't have IE handy to test, but maybe it's a compatibility mode thing? (Edit: ah, no, unlikely, given that it's running on a Stack snippet) – Sharl

Yes, I have installed both Chrome and IE 11 on my PC. – Alverson

You edited the link to the MDN in while I was answering - the first line of code on that page shows how to get hold of it in IE11 – Masterwork

@JamesThorpe - sorry, and yes you are right. But don't worry, your answer counts because it fixes the issue. Thank you for your help! – Alverson

Answer 1

According to the MDN, this feature is considered experimental in IE11. As such, it is prefixed with ms, and is accessible via window.msCrypto:

var randomValuesArray = new Int32Array(3);
var crypto = window.crypto || window.msCrypto;
crypto.getRandomValues(randomValuesArray);

var outputString = "";
for (var i = 0; i < randomValuesArray.length; i++) {
  if (i > 0) outputString += ",";
  outputString += randomValuesArray[i];
}
console.log(outputString);

Masterwork

Answer 2

The getRandomValues function is only supported in Internet Explorer 11. I had to add the following meta tag in the header section of the web page to allow Internet Explorer to choose what version of IE the page should be rendered with.

<meta http-equiv="X-UA-Compatible" content="IE=11">

Pesky