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import { concat, uint64be } from './buffer_utils.js';
import checkIvLength from './check_iv_length.js';
import checkCekLength from './check_cek_length.js';
import { checkEncCryptoKey } from './crypto_key.js';
import invalidKeyInput from './invalid_key_input.js';
import generateIv from './iv.js';
import { JOSENotSupported } from '../util/errors.js';
import { isCryptoKey } from './is_key_like.js';
async function cbcEncrypt(enc, plaintext, cek, iv, aad) {
if (!(cek instanceof Uint8Array)) {
throw new TypeError(invalidKeyInput(cek, 'Uint8Array'));
}
const keySize = parseInt(enc.slice(1, 4), 10);
const encKey = await crypto.subtle.importKey('raw', cek.subarray(keySize >> 3), 'AES-CBC', false, ['encrypt']);
const macKey = await crypto.subtle.importKey('raw', cek.subarray(0, keySize >> 3), {
hash: `SHA-${keySize << 1}`,
name: 'HMAC',
}, false, ['sign']);
const ciphertext = new Uint8Array(await crypto.subtle.encrypt({
iv,
name: 'AES-CBC',
}, encKey, plaintext));
const macData = concat(aad, iv, ciphertext, uint64be(aad.length << 3));
const tag = new Uint8Array((await crypto.subtle.sign('HMAC', macKey, macData)).slice(0, keySize >> 3));
return { ciphertext, tag, iv };
}
async function gcmEncrypt(enc, plaintext, cek, iv, aad) {
let encKey;
if (cek instanceof Uint8Array) {
encKey = await crypto.subtle.importKey('raw', cek, 'AES-GCM', false, ['encrypt']);
}
else {
checkEncCryptoKey(cek, enc, 'encrypt');
encKey = cek;
}
const encrypted = new Uint8Array(await crypto.subtle.encrypt({
additionalData: aad,
iv,
name: 'AES-GCM',
tagLength: 128,
}, encKey, plaintext));
const tag = encrypted.slice(-16);
const ciphertext = encrypted.slice(0, -16);
return { ciphertext, tag, iv };
}
export default async (enc, plaintext, cek, iv, aad) => {
if (!isCryptoKey(cek) && !(cek instanceof Uint8Array)) {
throw new TypeError(invalidKeyInput(cek, 'CryptoKey', 'KeyObject', 'Uint8Array', 'JSON Web Key'));
}
if (iv) {
checkIvLength(enc, iv);
}
else {
iv = generateIv(enc);
}
switch (enc) {
case 'A128CBC-HS256':
case 'A192CBC-HS384':
case 'A256CBC-HS512':
if (cek instanceof Uint8Array) {
checkCekLength(cek, parseInt(enc.slice(-3), 10));
}
return cbcEncrypt(enc, plaintext, cek, iv, aad);
case 'A128GCM':
case 'A192GCM':
case 'A256GCM':
if (cek instanceof Uint8Array) {
checkCekLength(cek, parseInt(enc.slice(1, 4), 10));
}
return gcmEncrypt(enc, plaintext, cek, iv, aad);
default:
throw new JOSENotSupported('Unsupported JWE Content Encryption Algorithm');
}
};
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