www-apps/pmwiki/cookbook/AesCrypt/JavaAesCryptTest/src/main/java/org/pmwiki/cookbook/aescrypt/Decrypt.java

   1 package org.pmwiki.cookbook.aescrypt;
   2
   3
   4 import javax.crypto.Cipher;
   5 import javax.crypto.spec.IvParameterSpec;
   6 import javax.crypto.spec.SecretKeySpec;
   7 import org.apache.commons.codec.binary.Base64;
   8 import org.apache.commons.codec.digest.DigestUtils;
   9
  10 /*
  11  * To change this template, choose Tools | Templates
  12  * and open the template in the editor.
  13  */
  14
  15 /**
  16  *
  17  * @author ludek
  18  * @author $Author$
  19  * @version $Rev$
  20  */
  21 public class Decrypt {
  22
  23     public static void main(String[] args)throws Exception
  24     {
  25         String password = "TopSecret";
  26         //String encrypted = "AAAAAAAAAABHtF/GUuR5r+R8gBpKzVQv3FT2osanEmZD1DvoR3m3sQ==";
  27         String encrypted = "AAAAAAAAAABHtF8=";
  28
  29         byte dataIn[] = Base64.decodeBase64(encrypted);
  30         byte nonce[] = new byte[16];
  31         byte enc[] = new byte[dataIn.length - 8];
  32
  33         System.arraycopy(dataIn, 0, nonce, 0, 8);
  34         System.arraycopy(dataIn, 8, enc, 0, dataIn.length - 8);
  35
  36         byte[] keyData = DigestUtils.sha256(password);
  37         SecretKeySpec key = new SecretKeySpec(keyData, "AES");
  38
  39         Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding");
  40         IvParameterSpec ivSpec = new IvParameterSpec(nonce);
  41         cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);
  42         byte[] resultData = cipher.doFinal(enc);
  43         System.out.println(new String(resultData));
  44     }
  45
  46 }