How do a LDAP search/authenticate against this LDAP in Java

Question

I am playing with LDAP and Java search. Here's my LDIF export with a simple organization

version: 1

dn: dc=example,dc=com
objectClass: organization
objectClass: dcObject
objectClass: top
dc: example
o: MyOrganization
description: Test Description

dn: ou=people, dc=example,dc=com
objectClass: organizationalUnit
objectClass: top
ou: people
description: All users in demo company

dn: cn=Johnny Doe,ou=people,dc=example,dc=com
objectClass: organizationalPerson
objectClass: person
objectClass: inetOrgPerson
objectClass: top
cn: Johnny Doe
sn: Johnny
homephone: 123-456-7890
mail: [email protected]
ou: Development
uid: jjohnny
userpassword:: johnny

dn: cn=Samuel Johnson,ou=people,dc=example,dc=com
objectClass: organizationalPerson
objectClass: person
objectClass: inetOrgPerson
objectClass: top
cn: Samuel Johnson
sn: Samuel
homephone: 123-456-7890
mail: [email protected]
ou: Accounts
uid: ssam
userpassword:: sammy

How do I run a Java snippet to get all users from the LDAP server? There's no authentication set-up on my Apache DS Directory Server.

Hashtable env = new Hashtable(11);
env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
env.put(Context.PROVIDER_URL, "ldap://localhost:10389/dc=example,dc=com");
env.put(Context.SECURITY_AUTHENTICATION, "none");

try {
    // Create initial context
    DirContext ctx = new InitialDirContext(env);
    Object obj = new Object();
    // want to print all users from the LDAP server
    System.out.println(obj.toString());
    ctx.close();
}

Solution 1

try {
    LdapContext ctx = new InitialLdapContext(env, null);
    ctx.setRequestControls(null);
    NamingEnumeration<?> namingEnum = ctx.search("ou=people,dc=example,dc=com", "(objectclass=user)", getSimpleSearchControls());
    while (namingEnum.hasMore ()) {
        SearchResult result = (SearchResult) namingEnum.next ();    
        Attributes attrs = result.getAttributes ();
        System.out.println(attrs.get("cn"));

    } 
    namingEnum.close();
} catch (Exception e) {
    e.printStackTrace();
}

private SearchControls getSimpleSearchControls() {
    SearchControls searchControls = new SearchControls();
    searchControls.setSearchScope(SearchControls.SUBTREE_SCOPE);
    searchControls.setTimeLimit(30000);
    //String[] attrIDs = {"objectGUID"};
    //searchControls.setReturningAttributes(attrIDs);
    return searchControls;
}

Solution 2

Another approach is using UnboundID. Its api is very readable and shorter

Create a Ldap Connection

public static LDAPConnection getConnection() throws LDAPException {
    // host, port, username and password
    return new LDAPConnection("com.example.local", 389, "[email protected]", "admin");
}

Get filter result

public static List<SearchResultEntry> getResults(LDAPConnection connection, String baseDN, String filter) throws LDAPSearchException {
    SearchResult searchResult;

    if (connection.isConnected()) {
        searchResult = connection.search(baseDN, SearchScope.ONE, filter);

        return searchResult.getSearchEntries();
    }

    return null;
}

Get all Oragnization Units and Containers

String baseDN = "DC=com,DC=example,DC=local";
String filter = "(&(|(objectClass=organizationalUnit)(objectClass=container)))";

LDAPConnection connection = getConnection();        
List<SearchResultEntry> results = getResults(connection, baseDN, filter);

Get a specific Organization Unit

String baseDN = "DC=com,DC=example,DC=local";
String dn = "CN=Users,DC=com,DC=example,DC=local";

String filterFormat = "(&(|(objectClass=organizationalUnit)(objectClass=container))(distinguishedName=%s))";
String filter = String.format(filterFormat, dn);

LDAPConnection connection =  getConnection();

List<SearchResultEntry> results = getResults(connection, baseDN, filter);

Get all users under an Organizational Unit

String baseDN = "CN=Users,DC=com,DC=example,DC=local";
String filter = "(&(objectClass=user)(!(objectCategory=computer)))";

LDAPConnection connection =  getConnection();       
List<SearchResultEntry> results = getResults(connection, baseDN, filter);

Get a specific user under an Organization Unit

String baseDN = "CN=Users,DC=com,DC=example,DC=local";
String userDN = "CN=abc,CN=Users,DC=com,DC=example,DC=local";

String filterFormat = "(&(objectClass=user)(distinguishedName=%s))";
String filter = String.format(filterFormat, userDN);

LDAPConnection connection =  getConnection();
List<SearchResultEntry> results = getResults(connection, baseDN, filter);

Display result

for (SearchResultEntry e : results) {
    System.out.println("name: " + e.getAttributeValue("name"));
}

Solution 3

You can also use the following code :

package com.agileinfotech.bsviewer.ldap;

import java.util.Hashtable;
import java.util.ResourceBundle;

import javax.naming.Context;
import javax.naming.NamingException;
import javax.naming.directory.DirContext;
import javax.naming.directory.InitialDirContext;

public class LDAPLoginAuthentication {
    public LDAPLoginAuthentication() {
        // TODO Auto-generated constructor
    }

    ResourceBundle resBundle = ResourceBundle.getBundle("settings");

    @SuppressWarnings("unchecked")
    public String authenticateUser(String username, String password) {
        String strUrl = "success";
        Hashtable env = new Hashtable(11);
        boolean b = false;
        String Securityprinciple = "cn=" + username + "," + resBundle.getString("UserSearch");
        env.put(Context.INITIAL_CONTEXT_FACTORY, resBundle.getString("InitialContextFactory"));
        env.put(Context.PROVIDER_URL, resBundle.getString("Provider_url"));
        env.put(Context.SECURITY_AUTHENTICATION, "simple");
        env.put(Context.SECURITY_PRINCIPAL, Securityprinciple);
        env.put(Context.SECURITY_CREDENTIALS, password);

        try {
            // Create initial context
            DirContext ctx = new InitialDirContext(env);
            // Close the context when we're done
            b = true;
            ctx.close();

        } catch (NamingException e) {
            b = false;
        } finally {
            if (b) {
                strUrl = "success";
            } else {
                strUrl = "failer";
            }
        }
        return strUrl;
    }
}

Comments

[Mossroy]

CAUTION, be aware that this implementation might allow users to authenticate with an empty password. See stackoverflow.com/questions/12359831/… . Depending on the LDAP server implementation, you will also need to check that the password parameter is not empty.

[DavidS]

This question has an answer that demonstrates authentication: stackoverflow.com/questions/12317205/…

[SatyaTNV]

Do I need to create and close LDAPConnection per each request?