AES加密代碼



public class EncryptUtil {
 // --------------------部分代碼-----------

 /**
  * AES加密
  *
  * @param key
  *            密鑰信息
  * @param content
  *            待加密信息
  */
 public static byte[] encodeAES(byte[] key, byte[] content) throws Exception {
  // 不是16的倍數的，補足
  int base = 16;
  if (key.length % base != 0) {
   int groups = key.length / base + (key.length % base != 0 ? 1 : 0);
   byte[] temp = new byte[groups * base];
   Arrays.fill(temp, (byte) 0);
   System.arraycopy(key, 0, temp, 0, key.length);
   key = temp;
  }

  SecretKey secretKey = new SecretKeySpec(key, "AES");
  IvParameterSpec iv = new IvParameterSpec(new byte[] { 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0 });
  Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
  cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);
  byte[] tgtBytes = cipher.doFinal(content);
  return tgtBytes;
 }

 /**
  * AES解密
  *
  * @param key
  *            密鑰信息
  * @param content
  *            待加密信息
  * @return
  * @throws Exception
  */
 public static byte[] decodeAES(byte[] key, byte[] content) throws Exception {
  // 不是16的倍數的，補足
  int base = 16;
  if (key.length % base != 0) {
   int groups = key.length / base + (key.length % base != 0 ? 1 : 0);
   byte[] temp = new byte[groups * base];
   Arrays.fill(temp, (byte) 0);
   System.arraycopy(key, 0, temp, 0, key.length);
   key = temp;
  }

  SecretKey secretKey = new SecretKeySpec(key, "AES");
  IvParameterSpec iv = new IvParameterSpec(new byte[] { 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0 });
  Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
  cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
  byte[] tgtBytes = cipher.doFinal(content);
  return tgtBytes;
 }
 
 
 
 
 //身份驗證使用這個方法。
 public static String encryptAES(String content, String key) {
  try {
   return bytesToHexString(encodeAES(key.getBytes(),
     content.getBytes()));
  } catch (Exception e) {
   return null;
  }
 }

 public static String decryptAES(String content, String key) {
  try {
   byte[] contentByte = hexStringToByte(content);
   return new String(decodeAES(key.getBytes(), contentByte),
     "UTF-8");
  } catch (Exception e) {
   return null;
  }
 }

 
 /**
  * 把字節數組轉換成16進制字符串
  *
  * @parambArray
  * @return
  */
 public static String bytesToHexString(byte[] bArray) {
  StringBuffer sb = new StringBuffer(bArray.length);
  String sTemp;
  for (int i = 0; i<bArray.length; i++) {
   sTemp = Integer.toHexString(0xFF &bArray[i]);
   if (sTemp.length() < 2)
    sb.append(0);
   sb.append(sTemp.toUpperCase());
  }
  return sb.toString();
 }

 /*
  * 把16進制字符串轉換成字節數組
 *
  * @param hex
  *
  * @return
  */
 public static byte[] hexStringToByte(String hex) {
  int len = (hex.length() / 2);
  byte[] result = new byte[len];
  char[] achar = hex.toCharArray();
  for (int i = 0; i<len; i++) {
   int pos = i * 2;
   result[i] = (byte) (toByte(achar[pos]) << 4 | toByte(achar[pos + 1]));
  }
  return result;
 }

 private static byte toByte(char c) {
  byte b = (byte) "0123456789ABCDEF".indexOf(c);
  return b;
 }
}