这个加密代码有什么问题？

Question

我有以下生成AES-128一次性密钥的代码。之后，我使用从证书读取的RSA公钥加密此一次性密钥。加密的字节总是0.为什么？

// Generate a one-time key 
    KeyGenerator keyGenerator = KeyGenerator.getInstance("AES"); 
    keyGenerator.init(128); 
    SecretKey oneTimeKey = keyGenerator.generateKey(); 
    System.out.println("Encrypted bytes length: " + oneTimeKey.getEncoded().length); // prints "Plain bytes length: 16" 

    // Retrieve public key from certificate 
    FileInputStream fileInputStream = new FileInputStream("D:\\test.cer"); 
    CertificateFactory factory = CertificateFactory.getInstance("X.509"); 
    X509Certificate certificate = (X509Certificate) factory.generateCertificate(fileInputStream); 
    PublicKey publicKey = certificate.getPublicKey(); 

    // Encrypt one-time key using the public key. 
    Cipher cipher = Cipher.getInstance("RSA"); 
    cipher.init(Cipher.ENCRYPT_MODE, publicKey); 
    ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(); 
    CipherOutputStream cipherOutputStream = new CipherOutputStream(byteArrayOutputStream, cipher); 
    cipherOutputStream.write(oneTimeKey.getEncoded(), 0, oneTimeKey.getEncoded().length); 

    // Retrieve the encrypted bytes. 
    System.out.println("Encrypted bytes length: " + byteArrayOutputStream.toByteArray().length); // prints "Encrypted bytes length: 0" 
    cipherOutputStream.close(); 

Answer 1

尝试在获取字节数组之前刷新密码输出流。