Hallo!
Hab hier ne Klasse die n Text mittels RSA verschlüsselt. Die Verschlüsselung klappt (jedenfalls schmiert das Programm nicht ab). Bei der Entschlüsselung läuft allerdings anscheinend was schief, sodass ich immer eine NullPointerException bekomme.
Ich hoffe ihr könnt mir helfen!
Danke schonmal!
Hab hier ne Klasse die n Text mittels RSA verschlüsselt. Die Verschlüsselung klappt (jedenfalls schmiert das Programm nicht ab). Bei der Entschlüsselung läuft allerdings anscheinend was schief, sodass ich immer eine NullPointerException bekomme.
Java:
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import javax.crypto.Cipher;
public class RsaCipher {
private static KeyPair key = null;
public static void main(String[] args) {
generateKey();
String text = "Pferde fressen keinen Gurkensalat";
String encrypted = encrypt(text, key.getPublic());
String decrypted = decrypt(text.getBytes(), key.getPrivate());
System.out.println("Encrypted: " + encrypted);
System.out.println("Decrypted: " + decrypted);
}
private static void generateKey() {
KeyPairGenerator keyGen = null;
try {
keyGen = KeyPairGenerator.getInstance("RSA");
keyGen.initialize(1024);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
key = keyGen.generateKeyPair();
}
public static String encrypt(String text, PublicKey pubKey) {
byte[] cipherText = null;
try {
// get an RSA cipher object and print the provider
final Cipher cipher = Cipher.getInstance("RSA");
// encrypt the plain text using the public key
cipher.init(Cipher.ENCRYPT_MODE, pubKey);
cipherText = cipher.doFinal(text.getBytes());
} catch (Exception e) {
e.printStackTrace();
}
return new String(cipherText);
}
public static String decrypt(byte[] text, PrivateKey priKey) {
byte[] dectyptedText = null;
try {
// get an RSA cipher object and print the provider
final Cipher cipher = Cipher.getInstance("RSA");
// decrypt the text using the private key
cipher.init(Cipher.DECRYPT_MODE, priKey);
dectyptedText = cipher.doFinal(text);
} catch (Exception ex) {
ex.printStackTrace();
}
return new String(dectyptedText);
}
}
Code:
javax.crypto.BadPaddingException: Decryption error
at sun.security.rsa.RSAPadding.unpadV15(Unknown Source)
at sun.security.rsa.RSAPadding.unpad(Unknown Source)
at com.sun.crypto.provider.RSACipher.doFinal(RSACipher.java:363)
at com.sun.crypto.provider.RSACipher.engineDoFinal(RSACipher.java:389)
at javax.crypto.Cipher.doFinal(Cipher.java:2165)
at RsaCipher.decrypt(RsaCipher.java:66)
at RsaCipher.main(RsaCipher.java:18)
Exception in thread "main" java.lang.NullPointerException
at java.lang.String.<init>(Unknown Source)
at RsaCipher.decrypt(RsaCipher.java:72)
at RsaCipher.main(RsaCipher.java:18)Ich hoffe ihr könnt mir helfen!
Danke schonmal!
