javax.crypto.BadPaddingException: Given final block not properly padded - This is the error which I've got. I do not know why. My code seems to be alright. The key is the same during encrypting and decrypting. What I can say is that none of the already answered questions contain solution for my problem. Here is my code:
public String decrypt(String text) throws Exception {
String key = "SiadajerSiadajer"; // 128 bit key
// Create key and cipher
Key aesKey = new SecretKeySpec(key.getBytes(), "AES");
Cipher cipher = Cipher.getInstance("AES");
// encrypt the text
byte[]encrypted = text.getBytes();
cipher.init(Cipher.DECRYPT_MODE, aesKey);
String decrypted = new String(cipher.doFinal(encrypted)); //Here is the error
return decrypted;
}
And the encryption mechanism in php
function encrypt($data, $size)
{
$length = $size - strlen($data) % $size;
return $data . str_repeat(chr($length), $length);
}
function decrypt($data)
{
return substr($data, 0, -ord($data[strlen($data) - 1]));
}
$key = "SiadajerSiadajer";
$iv_size = 16; // 128 bits
$iv = openssl_random_pseudo_bytes($iv_size, $strong);
$name = openssl_encrypt(encrypt($name, 16), 'AES-256-CBC', $key, 0, $iv);
EDIT
Now in the php part my code is:
$key = "SiadajerSiadajer";
$iv_size = 16; // 128 bits
$iv = openssl_random_pseudo_bytes($iv_size, $strong);
$EIV = base64_encode($iv);
$name = openssl_encrypt(encrypt($name, 16), 'AES-256-CBC', $key, 0, $EIV);
And it gives me warning:Warning: openssl_encrypt(): IV passed is 24 bytes long which is longer than the 16 expected by selected cipher, truncating in C:\xampp2\htdocs\standardfinalinserting.php on line 68
And in Java part my decryption method is exactly like in the answer for my question but after running it gives me an error: java.security.InvalidKeyException: Illegal key size on the line:
cipher.init(Cipher.DECRYPT_MODE, aesKey, ivParameterSpec);
EDIT 2:
So this is my whole Main class. It contains your whole Java code example
public class Main {
private byte[] padKey(byte[] key) {
byte[] paddedKey = new byte[32];
System.arraycopy(key, 0, paddedKey, 0, key.length);
return paddedKey;
}
private byte[] unpad(byte[] data) {
byte[] unpaddedData = new byte[data.length - data[data.length - 1]];
System.arraycopy(data, 0, unpaddedData, 0, unpaddedData.length);
return unpaddedData;
}
public String decrypt(String encodedJoinedData) throws Exception {
// Base64-decode the joined data
byte[] joinedData = Base64.decode(encodedJoinedData);
// Get IV and encrypted data
byte[] iv = new byte[16];
System.arraycopy(joinedData, 0, iv, 0, iv.length);
byte[] encryptedData = new byte[joinedData.length - iv.length];
System.arraycopy(joinedData, iv.length, encryptedData, 0, encryptedData.length);
// Pad key
byte[] key = padKey("SiadajerSiadajer".getBytes());
Key aesKey = new SecretKeySpec(key, "AES");
// Specify CBC-mode
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
cipher.init(Cipher.DECRYPT_MODE, aesKey, ivParameterSpec); //HERE IS THE ERROR
// Decrypt data
byte[] decryptedData = cipher.doFinal(encryptedData);
// Remove custom padding
byte[] unpaddedData = unpad(decryptedData);
return new String(unpaddedData);
}
public static void main(String[] args) throws Exception {
// TODO Auto-generated method stub
String encodedJoinedData = "RB6Au33KGOF1/z3BQKqievUmh81Y8q4uw7s4vEs9xurQmNZAKwmhRQtS9wGYKQj8cJaPpK2xaDzx3RppQ8PsM/rQ9/p0Lme+x75dozBEbmFn6Q9eCXOCiCivVsKzZ8Vz";
String decryptedData = new Main().decrypt(encodedJoinedData);
System.out.println(decryptedData + " - " + decryptedData.length());
}
}
Running the code results in error:
Exception in thread "main" java.security.InvalidKeyException: Illegal key size
at javax.crypto.Cipher.checkCryptoPerm(Cipher.java:1039)
at javax.crypto.Cipher.implInit(Cipher.java:805)
at javax.crypto.Cipher.chooseProvider(Cipher.java:864)
at javax.crypto.Cipher.init(Cipher.java:1396)
at javax.crypto.Cipher.init(Cipher.java:1327)
at com.dd.escuel.Main.decrypt(Main.java:43)
at com.dd.escuel.Main.main(Main.java:57)
