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import { concat, uint64be } from '../lib/buffer_utils.ts'import type { EncryptFunction } from './interfaces.d.ts'import checkIvLength from '../lib/check_iv_length.ts'import checkCekLength from './check_cek_length.ts'import crypto, { isCryptoKey } from './webcrypto.ts'import { checkEncCryptoKey } from '../lib/crypto_key.ts'import invalidKeyInput from '../lib/invalid_key_input.ts'import { JOSENotSupported } from '../util/errors.ts'
async function cbcEncrypt(  enc: string,  plaintext: Uint8Array,  cek: Uint8Array | CryptoKey,  iv: Uint8Array,  aad: Uint8Array,) {  if (!(cek instanceof Uint8Array)) {    throw new TypeError(invalidKeyInput(cek, 'Uint8Array'))  }  const keySize = parseInt(enc.substr(1, 3), 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 }}
async function gcmEncrypt(  enc: string,  plaintext: Uint8Array,  cek: Uint8Array | CryptoKey,  iv: Uint8Array,  aad: Uint8Array,) {  let encKey: CryptoKey  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(      {        // @ts-ignore        additionalData: aad,        iv,        name: 'AES-GCM',        tagLength: 128,      },      encKey,      plaintext,    ),  )
  const tag = encrypted.slice(-16)  const ciphertext = encrypted.slice(0, -16)
  return { ciphertext, tag }}
const encrypt: EncryptFunction = async (  enc: string,  plaintext: Uint8Array,  cek: unknown,  iv: Uint8Array,  aad: Uint8Array,) => {  if (!isCryptoKey(cek) && !(cek instanceof Uint8Array)) {    throw new TypeError(invalidKeyInput(cek, 'CryptoKey', 'Uint8Array'))  }
  checkIvLength(enc, iv)
  switch (enc) {    case 'A128CBC-HS256':    case 'A192CBC-HS384':    case 'A256CBC-HS512':      if (cek instanceof Uint8Array) checkCekLength(cek, parseInt(enc.substr(-3), 10))      return cbcEncrypt(enc, plaintext, cek, iv, aad)    case 'A128GCM':    case 'A192GCM':    case 'A256GCM':      if (cek instanceof Uint8Array) checkCekLength(cek, parseInt(enc.substr(1, 3), 10))      return gcmEncrypt(enc, plaintext, cek, iv, aad)    default:      throw new JOSENotSupported('Unsupported JWE Content Encryption Algorithm')  }}
export default encrypt