1718932 - Add BigInt64Array and BigUint64Array support to crypto.getRandomValues

Status: RESOLVED FIXED

(Core :: DOM: Web Crypto, enhancement)

Description

[Timothy Gu [:TimothyGu]]

Given

const b = new BigInt64Array(10);
crypto.getRandomValues(b);

I would expect b to be filled with randomly generated 64-bit integers. However, instead I get

Uncaught DOMException: The type of an object is incompatible with the expected type of the parameter associated to the object

Spec change is pending on https://github.com/w3c/webcrypto/issues/255. WPTs are in bug 1718919.

Comment 1

[Benjamin Beurdouche [:beurdouche]]

I am curious about the motivation to have signed integers here?

Comment 2

[Timothy Gu [:TimothyGu]]

There isn’t a real reason to prevent signed integers from working. BigInt64Array interprets uniformly random bytes as a uniform distribution on [-2^63, 2^63 - 1], which is what people expect. Same with Int8Array, Int16Array, and Int32Array, which are all already supported by crypto.getRandomValues.

What the check was intended to prevent was using Float32Array and Float64Array, since uniformly random bytes do not lead to a uniform distribution for IEEE floating-point numbers. There is no such concern with BigInt64Array or BigUint64Array.

Comment 3

[Timothy Gu [:TimothyGu]]

Attachment: Bug 1718932 - Support Big(U)Int64Array in crypto.getRandomValues. r=keeler

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/23e2efb39391
Support Big(U)Int64Array in crypto.getRandomValues. r=keeler

Comment 5

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/23e2efb39391