Java LDAP-确定用户是否在给定组中？

Question

我们使用Java LDAP API通过LDAP将用户登录到Active
Directory。我们希望增强登录功能，以进一步检查用户是否在给定的AD组中。有谁知道如何做到这一点？

当前代码：

import javax.naming.*;
import javax.naming.ldap.*;

LdapContext ctx = null;
Hashtable env = new Hashtable();
env.put(Context.INITIAL_CONTEXT_FACTORY,"com.sun.jndi.ldap.LdapCtxFactory");
env.put(Context.SECURITY_AUTHENTICATION,"simple");
env.put(Context.PROVIDER_URL, Config.get("ldap-url"));

try {
    Control[] connCtls = new Control[] {new FastBindConnectionControl()};
    ctx = new InitialLdapContext(env, connCtls);
    ctx.addToEnvironment(Context.SECURITY_PRINCIPAL, "DOMAIN\\" + username);
    ctx.addToEnvironment(Context.SECURITY_CREDENTIALS, password);
    ctx.reconnect(connCtls);
    /* TODO: Only return true if user is in group "ABC" */
    return true; //User authenticated
} catch (Exception e) {
    return false; //User could NOT be authenticated
} finally {
    ...
}

更新 ：请参阅下面的解决方案。

Answer 1

我们用下面的类解决了这个问题。只需调用authenticate方法：

import java.text.MessageFormat;
import java.util.*;    
import javax.naming.*;    
import org.apache.log4j.Level;

public class LdapGroupAuthenticator {
    public static final String DISTINGUISHED_NAME = "distinguishedName";
    public static final String CN = "cn";
    public static final String MEMBER = "member";
    public static final String MEMBER_OF = "memberOf";
    public static final String SEARCH_BY_SAM_ACCOUNT_NAME = "(SAMAccountName={0})";
    public static final String SEARCH_GROUP_BY_GROUP_CN = "(&(objectCategory=group)(cn={0}))";

    /*
     * Prepares and returns CN that can be used for AD query
     * e.g. Converts "CN=**Dev - Test Group" to "**Dev - Test Group"
     * Converts CN=**Dev - Test Group,OU=Distribution Lists,DC=DOMAIN,DC=com to "**Dev - Test Group"
     */
    public static String getCN(String cnName) {
        if (cnName != null && cnName.toUpperCase().startsWith("CN=")) {
            cnName = cnName.substring(3);
        }
        int position = cnName.indexOf(',');
        if (position == -1) {
            return cnName;
        } else {
            return cnName.substring(0, position);
        }
    }
    public static boolean isSame(String target, String candidate) {
        if (target != null && target.equalsIgnoreCase(candidate)) {
            return true;
        }
        return false;
    }

    public static boolean authenticate(String domain, String username, String password) {
        Hashtable env = new Hashtable();
        env.put(Context.INITIAL_CONTEXT_FACTORY,"com.sun.jndi.ldap.LdapCtxFactory");
        env.put(Context.PROVIDER_URL, "ldap://1.2.3.4:389");
        env.put(Context.SECURITY_AUTHENTICATION, "simple");
        env.put(Context.SECURITY_PRINCIPAL, domain + "\\" + username);
        env.put(Context.SECURITY_CREDENTIALS, password);
        DirContext ctx = null;
        String defaultSearchBase = "DC=DOMAIN,DC=com";
        String groupDistinguishedName = "DN=CN=DLS-APP-MyAdmin-C,OU=DLS File Permissions,DC=DOMAIN,DC=com";

        try {
            ctx = new InitialDirContext(env);

            // userName is SAMAccountName
            SearchResult sr = executeSearchSingleResult(ctx, SearchControls.SUBTREE_SCOPE, defaultSearchBase,
                    MessageFormat.format( SEARCH_BY_SAM_ACCOUNT_NAME, new Object[] {username}),
                    new String[] {DISTINGUISHED_NAME, CN, MEMBER_OF}
                    );

            String groupCN = getCN(groupDistinguishedName);
            HashMap processedUserGroups = new HashMap();
            HashMap unProcessedUserGroups = new HashMap();

            // Look for and process memberOf
            Attribute memberOf = sr.getAttributes().get(MEMBER_OF);
            if (memberOf != null) {
                for ( Enumeration e1 = memberOf.getAll() ; e1.hasMoreElements() ; ) {
                    String unprocessedGroupDN = e1.nextElement().toString();
                    String unprocessedGroupCN = getCN(unprocessedGroupDN);
                    // Quick check for direct membership
                    if (isSame (groupCN, unprocessedGroupCN) && isSame (groupDistinguishedName, unprocessedGroupDN)) {
                        Log.info(username + " is authorized.");
                        return true;
                    } else {
                        unProcessedUserGroups.put(unprocessedGroupDN, unprocessedGroupCN);
                    }
                }
                if (userMemberOf(ctx, defaultSearchBase, processedUserGroups, unProcessedUserGroups, groupCN, groupDistinguishedName)) {
                    Log.info(username + " is authorized.");
                    return true;
                }
            }

            Log.info(username + " is NOT authorized.");
            return false;
        } catch (AuthenticationException e) {
            Log.info(username + " is NOT authenticated");
            return false;
        } catch (NamingException e) {
            throw new SystemException(e);
        } finally {
            if (ctx != null) {
                try {
                    ctx.close();
                } catch (NamingException e) {
                    throw new SystemException(e);
                }
            }
        }
    }

    public static boolean userMemberOf(DirContext ctx, String searchBase, HashMap processedUserGroups, HashMap unProcessedUserGroups, String groupCN, String groupDistinguishedName) throws NamingException {
        HashMap newUnProcessedGroups = new HashMap();
        for (Iterator entry = unProcessedUserGroups.keySet().iterator(); entry.hasNext();) {
            String  unprocessedGroupDistinguishedName = (String) entry.next();
            String unprocessedGroupCN = (String)unProcessedUserGroups.get(unprocessedGroupDistinguishedName);
            if ( processedUserGroups.get(unprocessedGroupDistinguishedName) != null) {
                Log.info("Found  : " + unprocessedGroupDistinguishedName +" in processedGroups. skipping further processing of it..." );
                // We already traversed this.
                continue;
            }
            if (isSame (groupCN, unprocessedGroupCN) && isSame (groupDistinguishedName, unprocessedGroupDistinguishedName)) {
                Log.info("Found Match DistinguishedName : " + unprocessedGroupDistinguishedName +", CN : " + unprocessedGroupCN );
                return true;
            }
        }

        for (Iterator entry = unProcessedUserGroups.keySet().iterator(); entry.hasNext();) {
            String  unprocessedGroupDistinguishedName = (String) entry.next();
            String unprocessedGroupCN = (String)unProcessedUserGroups.get(unprocessedGroupDistinguishedName);

            processedUserGroups.put(unprocessedGroupDistinguishedName, unprocessedGroupCN);

            // Fetch Groups in unprocessedGroupCN and put them in newUnProcessedGroups
            NamingEnumeration ns = executeSearch(ctx, SearchControls.SUBTREE_SCOPE, searchBase,
                    MessageFormat.format( SEARCH_GROUP_BY_GROUP_CN, new Object[] {unprocessedGroupCN}),
                    new String[] {CN, DISTINGUISHED_NAME, MEMBER_OF});

            // Loop through the search results
            while (ns.hasMoreElements()) {
                SearchResult sr = (SearchResult) ns.next();

                // Make sure we're looking at correct distinguishedName, because we're querying by CN
                String userDistinguishedName = sr.getAttributes().get(DISTINGUISHED_NAME).get().toString();
                if (!isSame(unprocessedGroupDistinguishedName, userDistinguishedName)) {
                    Log.info("Processing CN : " + unprocessedGroupCN + ", DN : " + unprocessedGroupDistinguishedName +", Got DN : " + userDistinguishedName +", Ignoring...");
                    continue;
                }

                Log.info("Processing for memberOf CN : " + unprocessedGroupCN + ", DN : " + unprocessedGroupDistinguishedName);
                // Look for and process memberOf
                Attribute memberOf = sr.getAttributes().get(MEMBER_OF);
                if (memberOf != null) {
                    for ( Enumeration e1 = memberOf.getAll() ; e1.hasMoreElements() ; ) {
                        String unprocessedChildGroupDN = e1.nextElement().toString();
                        String unprocessedChildGroupCN = getCN(unprocessedChildGroupDN);
                        Log.info("Adding to List of un-processed groups : " + unprocessedChildGroupDN +", CN : " + unprocessedChildGroupCN);
                        newUnProcessedGroups.put(unprocessedChildGroupDN, unprocessedChildGroupCN);
                    }
                }
            }
        }
        if (newUnProcessedGroups.size() == 0) {
            Log.info("newUnProcessedGroups.size() is 0. returning false...");
            return false;
        }

        //  process unProcessedUserGroups
        return userMemberOf(ctx, searchBase, processedUserGroups, newUnProcessedGroups, groupCN, groupDistinguishedName);
    }

    private static NamingEnumeration executeSearch(DirContext ctx, int searchScope,  String searchBase, String searchFilter, String[] attributes) throws NamingException {
        // Create the search controls
        SearchControls searchCtls = new SearchControls();

        // Specify the attributes to return
        if (attributes != null) {
            searchCtls.setReturningAttributes(attributes);
        }

        // Specify the search scope
        searchCtls.setSearchScope(searchScope);

        // Search for objects using the filter
        NamingEnumeration result = ctx.search(searchBase, searchFilter,searchCtls);
        return result;
    }

    private static SearchResult executeSearchSingleResult(DirContext ctx, int searchScope,  String searchBase, String searchFilter, String[] attributes) throws NamingException {
        NamingEnumeration result = executeSearch(ctx, searchScope,  searchBase, searchFilter, attributes);

        SearchResult sr = null;
        // Loop through the search results
        while (result.hasMoreElements()) {
            sr = (SearchResult) result.next();
            break;
        }
        return sr;
    }
}