Merci Jérôme, we resolved the solution by writing the following class. It's not super but does the job:
import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
public class IPEncryptor
{
public static String MD5(String ip)
throws NoSuchAlgorithmException, UnsupportedEncodingException
{
MessageDigest md;
md = MessageDigest.getInstance("MD5");
byte[] md5hash = new byte[32];
byte[] ipParts = parseIP(ip);
md.update(ipParts, 0, ipParts.length);
md5hash = md.digest();
return convertToHex(md5hash);
}
private static String convertToHex(byte[] data)
{
StringBuffer buf = new StringBuffer();
for (int i = 0; i < data.length; i++)
{
int halfbyte = (data[i] >>> 4) & 0x0F;
int two_halfs = 0;
do
{
if ((0 <= halfbyte) && (halfbyte <= 9))
buf.append((char) ('0' + halfbyte));
else
buf.append((char) ('a' + (halfbyte - 10)));
halfbyte = data[i] & 0x0F;
} while(two_halfs++ < 1);
}
return buf.toString();
}
// Parses the input
private static byte[] parseIP(String address)
{
String[] addressParts = address.split(":");
String[] ipParts = addressParts[0].split("\\.");
int portHiByte = Integer.parseInt(addressParts[1]) / 256;
int portLoByte = Integer.parseInt(addressParts[1]) % 256;
int i = 0;
int j = 0;
byte[] ip = new byte[16];
ip[i++] = 0;
ip[i++] = 2;
ip[i++] = (byte)portHiByte;
ip[i++] = (byte)portLoByte;
for (j = 0; j < ipParts.length; j++, i++)
{
ip[i] = (byte)Integer.parseInt(ipParts[j]);
}
// pad the rest with ZEROs
for (; i < ip.length; ++i)
{
ip[i] = 0;
}
return ip;
}
}