Authenticating against Active Directory

Code to check that user credentials are valid

package myservlets;
 
import java.util.*;
import javax.naming.*;
import javax.naming.directory.*;
 
public class QueryNewAd {
 
 public String checkPass(String SERVER, String USERNAME, String PASS){
String server = "";
String userName = "";
String pass = "";
 
server = SERVER;
userName = USERNAME;
pass = PASS;
 
 
 
 try {
    Hashtable env = new Hashtable();
    env.put(Context.INITIAL_CONTEXT_FACTORY,
             "com.sun.jndi.ldap.LdapCtxFactory");
    env.put(Context.PROVIDER_URL,
             "LDAP://"+server+".camping.goldfinger.ac.uk:389"); //replace with your server URL/IP
             //only DIGEST-MD5 works with our Windows Active Directory
    env.put(Context.SECURITY_AUTHENTICATION,
             "DIGEST-MD5"); //No other SALS worked with me
    env.put(Context.SECURITY_PRINCIPAL,
            userName); // specify the username ONLY to let Microsoft Happy
    env.put(Context.SECURITY_CREDENTIALS, pass);   //the password
 
    DirContext ctx = new InitialDirContext(env);
 
    ctx.close();
 
  } catch(NamingException ne) {
    return "fail";
}
 
  //if no exception, the user is already authenticated.
    return "success";
}}
 
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