Merge commit 'be3e8236086165e5e45a5a10783823874b3f3ebd' as 'lib/vscode'

lib/vscode/src/vs/base/node/crypto.ts

@@ -0,0 +1,38 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as fs from 'fs';
+import * as crypto from 'crypto';
+import { once } from 'vs/base/common/functional';
+
+export async function checksum(path: string, sha1hash: string | undefined): Promise<void> {
+	const checksumPromise = new Promise<string | undefined>((resolve, reject) => {
+		const input = fs.createReadStream(path);
+		const hash = crypto.createHash('sha1');
+		input.pipe(hash);
+
+		const done = once((err?: Error, result?: string) => {
+			input.removeAllListeners();
+			hash.removeAllListeners();
+
+			if (err) {
+				reject(err);
+			} else {
+				resolve(result);
+			}
+		});
+
+		input.once('error', done);
+		input.once('end', done);
+		hash.once('error', done);
+		hash.once('data', (data: Buffer) => done(undefined, data.toString('hex')));
+	});
+
+	const hash = await checksumPromise;
+
+	if (hash !== sha1hash) {
+		throw new Error('Hash mismatch');
+	}
+}