package org.jboss.seam.wiki.util;
import java.security.MessageDigest;
import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.AutoCreate;
/**
* Not super safe, should use a random salt, prepended later on the digest.
* Should also iterate the hashing a few thousand times to make brute force
* attacks more difficult. Oh well, probably good enough for storing things
* in an internal database.
* <p/>
*/
@Name("hashUtil")
@AutoCreate
public class Hash {
String hashFunction = "MD5";
String charset = "UTF-8";
private static final char[] DIGITS = {
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
};
public String hash(String text) {
try {
MessageDigest md = MessageDigest.getInstance(hashFunction);
md.update(text.getBytes(charset));
byte[] raw = md.digest();
return new String(encodeHex(raw));
}
catch (Exception e) {
throw new RuntimeException(e);
}
}
public String getCharset() {
return charset;
}
public void setCharset(String charset) {
this.charset = charset;
}
public String getHashFunction() {
return hashFunction;
}
public void setHashFunction(String hashFunction) {
this.hashFunction = hashFunction;
}
public static char[] encodeHex(byte[] data) {
int l = data.length;
char[] out = new char[l << 1];
// two characters form the hex value.
for (int i = 0, j = 0; i < l; i++) {
out[j++] = DIGITS[(0xF0 & data[i]) >>> 4];
out[j++] = DIGITS[0x0F & data[i]];
}
return out;
}
}