Java公钥私钥解密问题
我正在尝试加密和解密消息，如下面的代码中所述。基本上我想用公钥加密消息并将加密的消息从字节数组转换为字符串。并将该字符串解密为原始文本。这是这两种方法。这里加密工作正常，但解密失败（错误是“数据必须从零开始”）。我认为这是因为我将加密的字节数组转换为字符串。
我该如何解决这个问题？ （我想将加密的字节数组作为字符串并使用它进行解密）是否还有其他方法（使用公钥和私钥）
public static String getEncryptedMessage(String publicKeyFilePath,
String plainMessage) {
byte[] encryptedBytes;
try {
Cipher cipher = Cipher.getInstance("RSA");
byte[] publicKeyContentsAsByteArray = getBytesFromFile(publicKeyFilePath);
PublicKey publicKey = getPublicKey(publicKeyContentsAsByteArray);
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
encryptedBytes = cipher.doFinal(plainMessage.getBytes());
return new String(encryptedBytes);
} catch (Throwable t) {
}
}
public static String getDecryptedMessage(
String privateKeyFilePath, String encryptedMessage)
{
byte[] decryptedMessage;
try {
Cipher cipher = Cipher.getInstance("RSA");
byte[] privateKeyContentsAsByteArray = getBytesFromFile(privateKeyFilePath);
PrivateKey privateKey = getPrivateKey(privateKeyContentsAsByteArray);
cipher.init(Cipher.DECRYPT_MODE, privateKey);
decryptedMessage = cipher.doFinal(encryptedMessage.getBytes());
return new String(decryptedMessage);
} catch (Throwable t) {
}
I am trying to encrypt and decrypt a message as mentioned in the below code. Basically I want to encrypt a message with a public key and convert that encrypted message from byte array to String. And decrypt this string into original text. Here are the both methods. Here encryption works fine but decryption fails (error is "Data must start with zero"). I think this is causing because I convert encrypted byte array into String.
How do I solve this? (I want to have encrypted byte array as string and use it for decryption) Is there any other approach (with public and private keys)
public static String getEncryptedMessage(String publicKeyFilePath,
String plainMessage) {
byte[] encryptedBytes;
try {
Cipher cipher = Cipher.getInstance("RSA");
byte[] publicKeyContentsAsByteArray = getBytesFromFile(publicKeyFilePath);
PublicKey publicKey = getPublicKey(publicKeyContentsAsByteArray);
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
encryptedBytes = cipher.doFinal(plainMessage.getBytes());
return new String(encryptedBytes);
} catch (Throwable t) {
}
}
public static String getDecryptedMessage(
String privateKeyFilePath, String encryptedMessage)
{
byte[] decryptedMessage;
try {
Cipher cipher = Cipher.getInstance("RSA");
byte[] privateKeyContentsAsByteArray = getBytesFromFile(privateKeyFilePath);
PrivateKey privateKey = getPrivateKey(privateKeyContentsAsByteArray);
cipher.init(Cipher.DECRYPT_MODE, privateKey);
decryptedMessage = cipher.doFinal(encryptedMessage.getBytes());
return new String(decryptedMessage);
} catch (Throwable t) {
}
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如果您查看此页面（http://www.wikijava.org/wiki/Secret_Key_Cryptography_Tutorial）您需要进行 Base-64 编码以将字节转换为字符串，然后要解密它，您只需对其进行解码然后解密即可。
例如，Base-64 编码使用字节的前 7 位来制作可打印或可通过电子邮件发送的内容。
更新：
我犯了一个错误，再次将其编码为 64 个字符，以便更容易用作可打印的内容。
If you look at this page (http://www.wikijava.org/wiki/Secret_Key_Cryptography_Tutorial) you will need to do base-64 encoding to turn the bytes into a string, then to decrypt it you would just decode it then decrypt.
Base-64 encoding uses the first 7 bits of a byte, to make something that is printable or emailable, for example.
UPDATE:
I made a mistake, there are 64 characters that it would be encoded in, again, in order to make it easier to use as something printable.
为什么不将消息从加密到解密视为字节数组？为什么中间要改成String呢？ （我知道这看起来像是一个问题，但实际上是一个答案......）
Why don't you treat the message as byte array from encryption to decryption? Why changing it to String in the middle? (I know it seems like a question, but it's actually an answer...)
直接对未格式化的数据使用 RSA 可能会使您的应用程序容易受到自适应选择密文攻击。有关详细信息，请参阅应用密码学手册第 8 章，第 288-289 页，CRC Press 的免费书籍。 （如果您真的对密码学感兴趣，购买绑定版是非常值得的-- 您会对价格的质量感到震惊。）
由于这种攻击，大多数集成 RSA 的协议都使用 RSA 来加密随机生成的会话密钥或对具有应该输出的哈希函数进行签名与随机的消息无法区分，或者使用格式非常仔细的消息，而这些消息将无法正确解释。 （有关详细信息，请参阅 HAC 中的注释 8.63。）
Using RSA directly on unformatted data may leave your application vulnerable to an adaptive chosen ciphertext attack. For details please see Chapter 8, pages 288-289, of the Handbook of Applied Cryptography, a freely-available book from CRC Press. (It's well worth buying the bound edition, if you're really interested in cryptography -- you'll be stunned at the quality for the price.)
Because of this attack, most protocols that integrate RSA use RSA for encrypting randomly-generated session keys or signing hash functions with outputs that ought to be indistinguishable from random, OR using very carefully formatted messages that will fail to be correctly interpreted. (See Note 8.63 in HAC for details.)