Take advantage of platform features in Microsoft Authentication extension (#166066)

extensions/microsoft-authentication/src/cryptoUtils.ts

@@ -0,0 +1,45 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+import { base64Encode } from './node/buffer';
+import { crypto } from './node/crypto';
+
+export function randomUUID() {
+	return crypto.randomUUID();
+}
+
+function dec2hex(dec: number): string {
+	return ('0' + dec.toString(16)).slice(-2);
+}
+
+export function generateCodeVerifier(): string {
+	const array = new Uint32Array(56 / 2);
+	crypto.getRandomValues(array);
+	return Array.from(array, dec2hex).join('');
+}
+
+function sha256(plain: string | undefined) {
+	const encoder = new TextEncoder();
+	const data = encoder.encode(plain);
+	return crypto.subtle.digest('SHA-256', data);
+}
+
+function base64urlencode(a: ArrayBuffer) {
+	let str = '';
+	const bytes = new Uint8Array(a);
+	const len = bytes.byteLength;
+	for (let i = 0; i < len; i++) {
+		str += String.fromCharCode(bytes[i]);
+	}
+	return base64Encode(str)
+		.replace(/\+/g, '-')
+		.replace(/\//g, '_')
+		.replace(/=+$/, '');
+}
+
+export async function generateCodeChallenge(v: string) {
+	const hashed = await sha256(v);
+	const base64encoded = base64urlencode(hashed);
+	return base64encoded;
+}