HashUtils.java

   1 package be.nikiroo.utils;
   2
   3 import java.io.UnsupportedEncodingException;
   4 import java.security.MessageDigest;
   5 import java.security.NoSuchAlgorithmException;
   6
   7 /**
   8  * Small class to easily hash some values in a few different ways.
   9  * <p>
  10  * Does <b>not</b> handle the salt itself, you have to add it yourself.
  11  *
  12  * @author niki
  13  */
  14 public class HashUtils {
  15         /**
  16          * Hash the given value.
  17          *
  18          * @param value
  19          *            the value to hash
  20          *
  21          * @return the hash that can be used to confirm a value
  22          *
  23          * @throws RuntimeException
  24          *             if UTF-8 support is not available (!) or SHA-512 support is
  25          *             not available
  26          * @throws NullPointerException
  27          *             if email or pass is NULL
  28          */
  29         static public String sha512(String value) {
  30                 return hash("SHA-512", value);
  31         }
  32
  33         /**
  34          * Hash the given value.
  35          *
  36          * @param value
  37          *            the value to hash
  38          *
  39          * @return the hash that can be used to confirm the a value
  40          *
  41          * @throws RuntimeException
  42          *             if UTF-8 support is not available (!) or MD5 support is not
  43          *             available
  44          * @throws NullPointerException
  45          *             if email or pass is NULL
  46          */
  47         static public String md5(String value) {
  48                 return hash("MD5", value);
  49         }
  50
  51         /**
  52          * Hash the given value.
  53          *
  54          * @param algo
  55          *            the hash algorithm to use ("MD5" and "SHA-512" are supported)
  56          * @param value
  57          *            the value to hash
  58          *
  59          * @return the hash that can be used to confirm a value
  60          *
  61          * @throws RuntimeException
  62          *             if UTF-8 support is not available (!) or the algorithm
  63          *             support is not available
  64          * @throws NullPointerException
  65          *             if email or pass is NULL
  66          */
  67         static private String hash(String algo, String value) {
  68                 try {
  69                         MessageDigest md = MessageDigest.getInstance(algo);
  70                         md.update(value.getBytes("UTF-8"));
  71                         byte byteData[] = md.digest();
  72
  73                         StringBuffer hexString = new StringBuffer();
  74                         for (int i = 0; i < byteData.length; i++) {
  75                                 String hex = Integer.toHexString(0xff & byteData[i]);
  76                                 if (hex.length() % 2 == 1)
  77                                         hexString.append('0');
  78                                 hexString.append(hex);
  79                         }
  80
  81                         return hexString.toString();
  82                 } catch (NoSuchAlgorithmException e) {
  83                         throw new RuntimeException(algo + " hashing not available", e);
  84                 } catch (UnsupportedEncodingException e) {
  85                         throw new RuntimeException(
  86                                         "UTF-8 encoding is required in a compatible JVM", e);
  87                 }
  88         }
  89 }