RSA Encryption / Decryption does not work

[Markus Schmider]

Hello,
to try out Java security features I have written the following class (I know I would not be really usefull, just for trying the API):

public class RSAEncrypter {
	
	private KeyPair keyPair;

	public RSAEncrypter() {
		super();
		try {
			KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
			keyPairGenerator.initialize(1024);
			this.keyPair = keyPairGenerator.generateKeyPair();
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}
		
	}
	
	public byte[] encrypt(String message) {
		byte[] encrypted = null;
		try {
			Cipher cipher = Cipher.getInstance("RSA");
			cipher.init(Cipher.ENCRYPT_MODE, this.keyPair.getPublic());
			encrypted = cipher.doFinal();
		} catch (NoSuchAlgorithmException e) {
			
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			
			e.printStackTrace();
		} catch (InvalidKeyException e) {
			
			e.printStackTrace();
		} catch (IllegalBlockSizeException e) {
			
			e.printStackTrace();
		} catch (BadPaddingException e) {
			
			e.printStackTrace();
		}
		return encrypted;
	}
	
	public String decrypte(byte[] encrypted) {
		byte[] decrypted = null;
		try {
			Cipher cipher = Cipher.getInstance("RSA");
			cipher.init(Cipher.DECRYPT_MODE, this.keyPair.getPrivate());
			decrypted = cipher.doFinal(encrypted);
		} catch (NoSuchAlgorithmException e) {
			
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			
			e.printStackTrace();
		} catch (InvalidKeyException e) {
			
			e.printStackTrace();
		} catch (IllegalBlockSizeException e) {
			
			e.printStackTrace();
		} catch (BadPaddingException e) {
			
			e.printStackTrace();
		}
		return new String(decrypted);
		
	}
	

}

I call it with the following code

RSAEncrypter rsaEncrypter = new RSAEncrypter();
String message = "Vivamus mea Lesbia";
String encryptedMessage = rsaEncrypter.encrypt(message);
System.out.println("Encypted");
System.out.println(new String(encryptedMessage));
System.out.println("Decrypted");
String decrypted = rsaEncrypter.decrypte(encryptedMessage);
System.out.println(decrypted);

However the original messages is not restored.
decrypted contains a String of zero-length.

Where is the mistake??

Thanks for any input,

Hans

[Rob Spoor]

Check out line 22.

[Markus Schmider]

I must be blind...

Thanks a lot

encrypted = cipher.doFinal(message.getBytes());

[Rob Spoor]

You're welcome