可能重复：
“javax.crypto.BadPaddingException: Data must start with zero” exception.
我试图将加密和解密方法的用法分成两个不同的类。但是，当我解密字符串时，我遇到了上述异常。
以下是我的代码：
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import javax.crypto.Cipher;
public class EncryptAndDecrypt {
/**
*
*/
public static Cipher createCipher () throws Exception{
Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
return cipher;
}
public static KeyPair generateKey () throws NoSuchAlgorithmException{
KeyPairGenerator keyGen = KeyPairGenerator.getInstance ("RSA");
keyGen.initialize(1024);
KeyPair key = keyGen.generateKeyPair();
return key;
}
public static byte [] encrypt (String str, Cipher cip, KeyPair key) {
byte [] cipherText = null;
try {
byte [] plainText = str.getBytes("UTF8");
cip.init(Cipher.ENCRYPT_MODE, key.getPublic());
cipherText = cip.doFinal(plainText);
}
catch (Exception e) {
e.printStackTrace();
}
return cipherText;
}
public static String decrypt (byte [] c, Cipher cip, KeyPair key) throws Exception {
cip.init(Cipher.DECRYPT_MODE, key.getPrivate());
byte [] decryptedPlainText = cip.doFinal (c);// exception occurred here
String decryptedPlainStr = new String (decryptedPlainText, "UTF8");
return decryptedPlainStr;
}
}
// A separate class that uses the encrypt method in EncryptAndDecrypt
public class EncryptionApp {
public static void main (String [] args) {
System.out.println (getEncrypted());
}
public static byte [] getEncrypted () {
byte [] encyptedByte = null;
try {
String plainText = "hello";
Cipher cip = EncryptAndDecrypt.createCipher();
KeyPair key = EncryptAndDecrypt.generateKey();
encyptedByte = EncryptAndDecrypt.encrypt(plainText, cip, key);
String str = new String (encyptedByte, "UTF8");
System.out.println (str);
}
catch (Exception e) {
e.printStackTrace();
}
return encyptedByte;
}
}
public class DecryptedApp {
/**
* A separate class to use the decrypt method in EncryptAndDecrypt
*/
public static void main(String[] args) {
System.out.println (useDecrypted ());
}
public static String useDecrypted () {
String decryptedText = null;
try {
Cipher cip = EncryptAndDecrypt.createCipher();
KeyPair key = EncryptAndDecrypt.generateKey();
byte [] encrypted = EncryptionApp.getEncrypted();
System.out.println (encrypted);
decryptedText = EncryptAndDecrypt.decrypt(encrypted, cip, key) ;
}
catch (Exception e) {
e.printStackTrace();
} return decryptedText;
}
}