deno/js/get_random_values.ts
2019-05-17 14:03:01 -04:00

35 lines
1.1 KiB
TypeScript

// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
import * as msg from "gen/cli/msg_generated";
import * as flatbuffers from "./flatbuffers";
import * as dispatch from "./dispatch";
import { assert } from "./util";
function req(
typedArray: ArrayBufferView
): [flatbuffers.Builder, msg.Any, flatbuffers.Offset, ArrayBufferView] {
const builder = flatbuffers.createBuilder();
const inner = msg.GetRandomValues.createGetRandomValues(builder);
return [builder, msg.Any.GetRandomValues, inner, typedArray];
}
/** Synchronously collects cryptographically secure random values. The
* underlying CSPRNG in use is Rust's `rand::rngs::ThreadRng`.
*
* const arr = new Uint8Array(32);
* crypto.getRandomValues(arr);
*/
export function getRandomValues<
T extends
| Int8Array
| Uint8Array
| Uint8ClampedArray
| Int16Array
| Uint16Array
| Int32Array
| Uint32Array
>(typedArray: T): T {
assert(typedArray !== null, "Input must not be null");
assert(typedArray.length <= 65536, "Input must not be longer than 65536");
dispatch.sendSync(...req(typedArray as ArrayBufferView));
return typedArray;
}