Hello.
I'm working on a project that requires some data to be encrypted with AES 128. My encryption works fine but when I decrypt I get an Exception in thread "main" javax.crypto.IllegalBlockSizeException: Input length not multiple of 16 bytes exception.
Code:
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
public class AESCipher {
private final String INCORRECT_PASSWORD_LENGTH = "The password provided must be a length of " +
"16 bytes.";
private String password;
private SecretKeySpec key;
private Cipher cipher;
/**
* Generate the key from the password.
*/
private void generateKey() throws Exception {
key = new SecretKeySpec(this.password.getBytes(), "AES");
cipher = Cipher.getInstance("AES/CBC/NoPadding");
}
/**
* Encrypt the data.
* @param plainText
* The data to encrypt.
* @return
* Encrypted data.
* @throws Exception
* Exception if something went wrong.
*/
public String encrypt(String plainText) throws Exception {
byte[] cipherText;
int cipherTextLength;
cipher.init(Cipher.ENCRYPT_MODE, key);
cipherText = new byte[cipher.getOutputSize(plainText.getBytes().length)];
cipherTextLength = cipher.update(plainText.getBytes(), 0, plainText.getBytes().length,
cipherText, 0);
cipherTextLength += cipher.doFinal(cipherText, cipherTextLength);
System.out.println(new String(cipherText));
return new String(cipherText);
}
/**
* Decrypts the data.
* @param cipherText
* The data to decrypt.
* @return
* Decrypted data.
* @throws Exception
* Exception if something went wrong.
*/
public String decrypt(String cipherText) throws Exception {
byte[] plainText;
int plainTextLength;
cipher.init(Cipher.DECRYPT_MODE, key);
plainText = new byte[cipher.getOutputSize(cipherText.getBytes().length)];
plainTextLength = cipher.update(cipherText.getBytes(), 0, cipherText.getBytes().length,
plainText, 0);
plainTextLength += cipher.doFinal(plainText, plainTextLength);
System.out.println(new String(plainText));
return new String(plainText);
}
/**
* Class initializer for AES encryption.
* @param password
* The password that will be used to encrypt the data.
* @throws EncryptionException
* If something went wrong during initialization, encryption and/or decryption.
*/
public AESCipher(String password) throws EncryptionException {
if(password.length() != 16) {
throw new EncryptionException(INCORRECT_PASSWORD_LENGTH);
}
this.password = password;
try {
generateKey();
} catch(Exception error) {
throw new EncryptionException(error.getMessage());
}
}
}
Main method code:
public static void main(String[] args) throws Exception {
AESCipher aes = new AESCipher("abcdfjlwrd1esfjl");
String str = aes.encrypt("hello");
aes.decrypt(str);
}
What is wrong and how do I fix it.
