java javax.crypto.BadPaddingException：未知块类型
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javax.crypto.BadPaddingException: unknown block type
提问by Dilshan
I am trying to simulate asymmetric key system. I use following code to generate key pairs, encrypt, decrypt passwords. I have a distributed environment and for the moment I save the keys generated in a file system. I know that is not secure but its just for testing purposes.
我正在尝试模拟非对称密钥系统。我使用以下代码生成密钥对、加密、解密密码。我有一个分布式环境，目前我将生成的密钥保存在文件系统中。我知道这不安全，但仅用于测试目的。
private static SecureRandom random = new SecureRandom();
static {
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
}
protected synchronized void generateKeys() throws InvalidKeyException, IllegalBlockSizeException,
BadPaddingException, NoSuchAlgorithmException, NoSuchProviderException,
NoSuchPaddingException {
KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA", "BC");
generator.initialize(256, random);
KeyPair pair = generator.generateKeyPair();
Key pubKey = pair.getPublic();
Key privKey = pair.getPrivate();
//store public key
try {
storeKey(pubKey, Constants.KEY_PATH.concat(Constants.SERVER_PREFIX.concat("-publickey")));
} catch (Exception e) {
e.printStackTrace();
DBLogger.logMessage(e.toString(), Status.KEY_GENERATION_ERROR);
}
//store private key
try {
storeKey(privKey, Constants.KEY_PATH.concat(Constants.SERVER_PREFIX.concat("-privatekey")));
} catch (Exception e) {
e.printStackTrace();
DBLogger.logMessage(e.toString(), Status.KEY_GENERATION_ERROR);
}
}
protected synchronized String encryptUsingPublicKey(String plainText) throws IllegalBlockSizeException, BadPaddingException,
NoSuchAlgorithmException, NoSuchProviderException, NoSuchPaddingException, InvalidKeyException,
FileNotFoundException, IOException, ClassNotFoundException {
Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding", "BC");
cipher.init(Cipher.ENCRYPT_MODE, readKey(Constants.KEY_PATH.concat(Constants.SERVER_PREFIX.concat("-publickey"))), random);
byte[] cipherText = cipher.doFinal(plainText.getBytes());
System.out.println("cipher: " + new String(cipherText));
return new String(cipherText);
}
protected synchronized String decryptUsingPrivatekey(String cipherText) throws NoSuchAlgorithmException,
NoSuchProviderException, NoSuchPaddingException, InvalidKeyException, FileNotFoundException,
IOException, ClassNotFoundException, IllegalBlockSizeException, BadPaddingException {
Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding", "BC");
cipher.init(Cipher.DECRYPT_MODE, readKey(Constants.KEY_PATH.concat(Constants.SERVER_PREFIX.concat("-privatekey"))));
byte[] plainText = cipher.doFinal(cipherText.getBytes());
System.out.println("plain : " + new String(plainText));
return new String(plainText);
}
public static void main(String[] args) {
KeyGenerator keyGenerator = new KeyGenerator();
try {
keyGenerator.deleteAllKeys(Constants.KEY_PATH);
keyGenerator.generateKeys();
String cipherText = keyGenerator.encryptUsingPrivateKey("dilshan");
keyGenerator.decryptUsingPublickey(cipherText);
// String cipherText = keyGenerator.encryptUsingPublicKey("dilshan1");
// keyGenerator.decryptUsingPrivatekey(cipherText);
} catch (Exception e) {
e.printStackTrace();
DBLogger.logMessage(e.toString(), Status.KEY_GENERATION_ERROR);
}
}
This works perfectly well in most of the time. But some times it generates following error. This happens occasionally. Most of the time this works so I have no issue is with the code. I belive this is something to do with the serialization/serialization process to file system. Help is appreciated.
这在大多数情况下都非常有效。但有时它会产生以下错误。这种情况偶尔会发生。大多数情况下这是有效的，所以我对代码没有问题。我相信这与文件系统的序列化/序列化过程有关。帮助表示赞赏。
Note : I am using bouncycastle.
注意：我正在使用 bouncycastle。
Error is as follows,
错误如下，
javax.crypto.BadPaddingException: unknown block type
at org.bouncycastle.jcajce.provider.asymmetric.rsa.CipherSpi.engineDoFinal(Unknown Source)
at javax.crypto.Cipher.doFinal(DashoA13*..)
at com.dilshan.ttp.web.KeyGenerator.decryptUsingPublickey(KeyGenerator.java:105)
at com.dilshan.ttp.web.KeyGenerator.main(KeyGenerator.java:150)
Happens at,
发生在，
byte[] plainText = cipher.doFinal(cipherText.getBytes());
in decryptUsingPrivatekey method.
在decryptUsingPrivatekey 方法中。
回答by Henry
The cipher text is binary data. If you convert it to a Stringusing the default encoding it is very likely that you encounter byte sequences that cannot be represented by a character. Thus, during decryption when you convert the Stringback to a byte array you don't end up with the same bytes and the decryption fails.
密文是二进制数据。如果String使用默认编码将其转换为 a ，则很可能会遇到无法由字符表示的字节序列。因此，在解密期间，当您将其转换String回字节数组时，您最终不会得到相同的字节并且解密失败。
To solve that, don't convert the cipher text to a string, instead carry the byte[] around.
为了解决这个问题，不要将密文转换为字符串，而是随身携带 byte[] 。
