Java RSA加密

Question

我试图来回编码一个简单的字符串"测试".

public static String encode(Key publicKey, String data) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException {

    byte[] byteData = data.getBytes(); // convert string to byte array

    Cipher cipher = Cipher.getInstance(ALGORITHM); // create conversion processing object
    cipher.init(Cipher.ENCRYPT_MODE, publicKey); // initialize object's mode and key

    byte[] encryptedByteData = cipher.doFinal(byteData); // use object for encryption

    return new String(encryptedByteData); // convert encrypted byte array to string and return it

}

public static String decode(Key privateKey, String data) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException {

    byte[] byteData = data.getBytes(); // convert string to byte array

    Cipher cipher = Cipher.getInstance(ALGORITHM); // create conversion processing object
    cipher.init(Cipher.DECRYPT_MODE, privateKey); // initialize object's mode and key

    System.out.println(byteData.length);

    byte[] decryptedByteData = cipher.doFinal(byteData); // use object for decryption

    return new String(decryptedByteData); // convert decrypted byte array to string and return it

}

但是,尽管加密工作正常(ALGORITHM是"RSA"),但在尝试解密我刚从加密"test"获得的字符串时,我得到以下异常:

javax.crypto.IllegalBlockSizeException:数据不得超过256个字节

我应该将加密的字节分成256块,以便能够解密吗？

Answer 1

您无法将随机字节可靠地转换为a String.结果取决于运行此命令的计算机上的默认字符编码.使用许多编码时,密文将被破坏,信息将丢失.

修改您的代码以使用byte[]替代('doFinal()`方法的结果.

如果需要将其转换为byte[]字符串,请使用Base-64之类的编码.