jose/dist/node/esm/runtime/aeskw.js
2021-10-18 14:06:42 +02:00

50 lines
2.1 KiB
JavaScript

import { Buffer } from 'buffer';
import { KeyObject, createDecipheriv, createCipheriv } from 'crypto';
import { JOSENotSupported } from '../util/errors.js';
import { concat } from '../lib/buffer_utils.js';
import getSecretKey from './secret_key.js';
import { isCryptoKey } from './webcrypto.js';
import { checkEncCryptoKey } from '../lib/crypto_key.js';
import isKeyObject from './is_key_object.js';
import invalidKeyInput from '../lib/invalid_key_input.js';
import supported from './ciphers.js';
function checkKeySize(key, alg) {
if (key.symmetricKeySize << 3 !== parseInt(alg.substr(1, 3), 10)) {
throw new TypeError(`Invalid key size for alg: ${alg}`);
}
}
function ensureKeyObject(key, alg, usage) {
if (isKeyObject(key)) {
return key;
}
if (key instanceof Uint8Array) {
return getSecretKey(key);
}
if (isCryptoKey(key)) {
checkEncCryptoKey(key, alg, usage);
return KeyObject.from(key);
}
throw new TypeError(invalidKeyInput(key, 'KeyObject', 'CryptoKey', 'Uint8Array'));
}
export const wrap = async (alg, key, cek) => {
const size = parseInt(alg.substr(1, 3), 10);
const algorithm = `aes${size}-wrap`;
if (!supported(algorithm)) {
throw new JOSENotSupported(`alg ${alg} is not supported either by JOSE or your javascript runtime`);
}
const keyObject = ensureKeyObject(key, alg, 'wrapKey');
checkKeySize(keyObject, alg);
const cipher = createCipheriv(algorithm, keyObject, Buffer.alloc(8, 0xa6));
return concat(cipher.update(cek), cipher.final());
};
export const unwrap = async (alg, key, encryptedKey) => {
const size = parseInt(alg.substr(1, 3), 10);
const algorithm = `aes${size}-wrap`;
if (!supported(algorithm)) {
throw new JOSENotSupported(`alg ${alg} is not supported either by JOSE or your javascript runtime`);
}
const keyObject = ensureKeyObject(key, alg, 'unwrapKey');
checkKeySize(keyObject, alg);
const cipher = createDecipheriv(algorithm, keyObject, Buffer.alloc(8, 0xa6));
return concat(cipher.update(encryptedKey), cipher.final());
};