aes cbc ,secret key 为 128bit
decrypt(ciphertext: ArrayBuffer | Uint8Array,iv: ArrayBuffer | Uint8Array,): Promise<ArrayBuffer>
encrypt(plaintext: ArrayBuffer | Uint8Array,iv: ArrayBuffer | Uint8Array,): Promise<ArrayBuffer>
private
initCryptoKey(force?: boolean): Promise<void>
parseKey(serverKey: ArrayBuffer): Promise<CryptoKey>