I need to Encrypt XML message (it comes as String) using AES 256 with 32 bytes key. I have tried the following (from http://aesencryption.net/) :
import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.binary.Base64;
/**
Aes encryption
*/
public class AES
{
private static SecretKeySpec secretKey ;
private static byte[] key ;
private static String decryptedString;
private static String encryptedString;
public static void setKey(String myKey){
MessageDigest sha = null;
try {
key = myKey.getBytes("UTF-8");
System.out.println(key.length);
sha = MessageDigest.getInstance("SHA-1");
key = sha.digest(key);
key = Arrays.copyOf(key, 16); // use only first 128 bit
System.out.println(key.length);
System.out.println(new String(key,"UTF-8"));
secretKey = new SecretKeySpec(key, "AES");
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static String getDecryptedString() {
return decryptedString;
}
public static void setDecryptedString(String decryptedString) {
AES.decryptedString = decryptedString;
}
public static String getEncryptedString() {
return encryptedString;
}
public static void setEncryptedString(String encryptedString) {
AES.encryptedString = encryptedString;
}
public static String encrypt(String strToEncrypt)
{
try
{
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
setEncryptedString(Base64.encodeBase64String(cipher.doFinal(strToEncrypt.getBytes("UTF-8"))));
}
catch (Exception e)
{
System.out.println("Error while encrypting: "+e.toString());
}
return null;
}
public static String decrypt(String strToDecrypt)
{
try
{
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
cipher.init(Cipher.DECRYPT_MODE, secretKey);
setDecryptedString(new String(cipher.doFinal(Base64.decodeBase64(strToDecrypt))));
}
catch (Exception e)
{
System.out.println("Error while decrypting: "+e.toString());
}
return null;
}
public static void main(String args[])
{
final String strToEncrypt = "My text to encrypt";
final String strPssword = "C0BAE23DF8B51807B3E17D21925FADF273A70181E1D81B8EDE6C76A5C1F1716E";
AES.setKey(strPssword);
AES.encrypt(strToEncrypt.trim());
System.out.println("String to Encrypt: " + strToEncrypt);
System.out.println("Encrypted: " + AES.getEncryptedString());
final String strToDecrypt = AES.getEncryptedString();
AES.decrypt(strToDecrypt.trim());
System.out.println("String To Decrypt : " + strToDecrypt);
System.out.println("Decrypted : " + AES.getDecryptedString());
}
}
I tried to change key array lenght from 16 to 32 and used a larger input String
(I think that's 32 lenght key) but that doesn't work.
key = Arrays.copyOf(key, 32);
Message to encrypt will be as simple as:
<Estructure>
<General>GENERAL DATA</General>
</Estructure>
<Datos>
<DATE>20140606</DATE>
</Datos>
When I run that I get the following Exception:
Error while encrypting: java.security.InvalidKeyException: Illegal key size or default parameters
It works perfectly when using 16 byte Lenght key. How can I make it work with 32 bytes?
