Implement initial crypto.subtle.decrypt() for "AES-CBC"

apps/tests/src/crypto.test.ts

@@ -9,6 +9,14 @@ function toHex(arr: ArrayBuffer) {
 		.join('');
 }
 
+function fromHex(hex: string): ArrayBuffer {
+	const arr = new Uint8Array(hex.length / 2);
+	for (let i = 0; i < hex.length; i += 2) {
+		arr[i / 2] = parseInt(hex.substr(i, 2), 16);
+	}
+	return arr.buffer;
+}
+
 test('`crypto.getRandomValues()`', () => {
 	const arr = new Uint8Array(5);
 	assert.equal(toHex(arr.buffer), '0000000000');
@@ -49,4 +57,71 @@ test("`crypto.subtle.digest('sha-512')`", async () => {
 	);
 });
 
+test("`crypto.subtle.importKey()` with 'raw' format and 'AES-CBC' algorithm`", async () => {
+	const keyData = new Uint8Array([
+		188, 136, 184, 200, 227, 200, 149, 203, 33, 186, 60, 145, 54, 19, 92, 88,
+	]);
+
+	const key = await crypto.subtle.importKey(
+		'raw',
+		keyData,
+		{ name: 'AES-CBC' },
+		false,
+		['encrypt', 'decrypt'],
+	);
+
+	assert.instance(key, CryptoKey);
+	assert.equal(key.algorithm.name, 'AES-CBC');
+	// @ts-expect-error `length` is not defined on `KeyAlgorithm`
+	assert.equal(key.algorithm.length, 128);
+});
+
+test("`crypto.subtle.encrypt()` with 'AES-CBC' algorithm`", async () => {
+	const keyData = new Uint8Array([
+		188, 136, 184, 200, 227, 200, 149, 203, 33, 186, 60, 145, 54, 19, 92, 88,
+	]);
+	const iv = new Uint8Array([
+		38, 89, 172, 231, 98, 165, 172, 212, 137, 184, 41, 162, 105, 26, 119, 158,
+	]);
+
+	const key = await crypto.subtle.importKey(
+		'raw',
+		keyData,
+		{ name: 'AES-CBC' },
+		false,
+		['encrypt'],
+	);
+
+	const ciphertext = await crypto.subtle.encrypt(
+		{ name: 'AES-CBC', iv: iv.buffer },
+		key,
+		new TextEncoder().encode('hello'),
+	);
+
+	assert.instance(ciphertext, ArrayBuffer);
+	assert.equal(toHex(ciphertext), '4b4fddd4b88f2e6a36500f89aa177d0d');
+});
+
+test("`crypto.subtle.decrypt()` with 'AES-CBC' algorithm`", async () => {
+	const keyData = new Uint8Array([
+		188, 136, 184, 200, 227, 200, 149, 203, 33, 186, 60, 145, 54, 19, 92, 88,
+	]);
+	const iv = new Uint8Array([
+		38, 89, 172, 231, 98, 165, 172, 212, 137, 184, 41, 162, 105, 26, 119, 158,
+	]);
+
+	const key = await crypto.subtle.importKey('raw', keyData, 'AES-CBC', false, [
+		'decrypt',
+	]);
+
+	const plaintext = await crypto.subtle.decrypt(
+		{ name: 'AES-CBC', iv },
+		key,
+		fromHex('4b4fddd4b88f2e6a36500f89aa177d0d'),
+	);
+
+	assert.instance(plaintext, ArrayBuffer);
+	assert.equal(new TextDecoder().decode(new Uint8Array(plaintext)), 'hello');
+});
+
 test.run();

packages/runtime/src/$.ts

@@ -39,7 +39,7 @@ import type { URL, URLSearchParams } from './polyfills/url';
 import type { DOMPoint, DOMPointInit } from './dompoint';
 import type { DOMMatrix, DOMMatrixReadOnly, DOMMatrixInit } from './dommatrix';
 import type { Gamepad, GamepadButton } from './navigator/gamepad';
-import type { CryptoKey } from './crypto';
+import type { CryptoKey, SubtleCrypto } from './crypto';
 import type { Algorithm } from './types';
 import type { PromiseState } from '@nx.js/inspect';
 
@@ -127,6 +127,7 @@ export interface Init {
 		keyUsages: KeyUsage[],
 	): CryptoKey;
 	cryptoKeyInit(c: ClassOf<CryptoKey>): void;
+	cryptoSubtleInit(c: ClassOf<SubtleCrypto>): void;
 	cryptoEncrypt(
 		algorithm: Algorithm,
 		key: CryptoKey,

packages/runtime/src/crypto.ts

@@ -5,6 +5,7 @@ import {
 	bufferSourceToArrayBuffer,
 	createInternal,
 	def,
+	stub,
 } from './utils';
 import { CryptoKey } from './crypto/crypto-key';
 import type {
@@ -140,6 +141,14 @@ export class SubtleCrypto implements globalThis.SubtleCrypto {
 		assertInternalConstructor(arguments);
 	}
 
+	/**
+	 * Decrypts some encrypted data.
+	 *
+	 * It takes as arguments a key to decrypt with, some optional extra parameters, and the data to decrypt (also known as "ciphertext").
+	 *
+	 * @returns A Promise which will be fulfilled with the decrypted data (also known as "plaintext") as an `ArrayBuffer`.
+	 * @see https://developer.mozilla.org/docs/Web/API/SubtleCrypto/decrypt
+	 */
 	decrypt(
 		algorithm:
 			| AlgorithmIdentifier
@@ -150,7 +159,7 @@ export class SubtleCrypto implements globalThis.SubtleCrypto {
 		key: CryptoKey,
 		data: BufferSource,
 	): Promise<ArrayBuffer> {
-		throw new Error('Method not implemented.');
+		stub();
 	}
 
 	deriveBits(
@@ -278,6 +287,12 @@ export class SubtleCrypto implements globalThis.SubtleCrypto {
 		throw new Error('Method not implemented.');
 	}
 
+	/**
+	 * Takes as input a key in an external, portable format and gives you a
+	 * {@link CryptoKey} object that you can use in the Web Crypto API.
+	 *
+	 * @see https://developer.mozilla.org/docs/Web/API/SubtleCrypto/importKey
+	 */
 	importKey(
 		format: 'jwk',
 		keyData: JsonWebKey,
@@ -381,6 +396,7 @@ export class SubtleCrypto implements globalThis.SubtleCrypto {
 		throw new Error('Method not implemented.');
 	}
 }
+$.cryptoSubtleInit(SubtleCrypto);
 def(SubtleCrypto);
 
 function normalizeAlgorithm(algorithm: AlgorithmIdentifier): Algorithm {