src/com/gitblit/LdapUserService.java - gitblit - Git at Google

 /*
  * Copyright 2012 John Crygier
  * Copyright 2012 gitblit.com
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package com.gitblit;

 import java.io.File;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.security.GeneralSecurityException;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicLong;

 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import com.gitblit.Constants.AccountType;
 import com.gitblit.models.TeamModel;
 import com.gitblit.models.UserModel;
 import com.gitblit.utils.ArrayUtils;
 import com.gitblit.utils.StringUtils;
 import com.unboundid.ldap.sdk.Attribute;
 import com.unboundid.ldap.sdk.ExtendedResult;
 import com.unboundid.ldap.sdk.LDAPConnection;
 import com.unboundid.ldap.sdk.LDAPException;
 import com.unboundid.ldap.sdk.LDAPSearchException;
 import com.unboundid.ldap.sdk.ResultCode;
 import com.unboundid.ldap.sdk.SearchResult;
 import com.unboundid.ldap.sdk.SearchResultEntry;
 import com.unboundid.ldap.sdk.SearchScope;
 import com.unboundid.ldap.sdk.extensions.StartTLSExtendedRequest;
 import com.unboundid.util.ssl.SSLUtil;
 import com.unboundid.util.ssl.TrustAllTrustManager;

 /**
  * Implementation of an LDAP user service.
  *
  * @author John Crygier
  */
 public class LdapUserService extends GitblitUserService {

 	public static final Logger logger = LoggerFactory.getLogger(LdapUserService.class);

 	private IStoredSettings settings;
     private AtomicLong lastLdapUserSync = new AtomicLong(0L);

 	public LdapUserService() {
 		super();
 	}

  	private long getSynchronizationPeriod() {
         final String cacheDuration = settings.getString(Keys.realm.ldap.ldapCachePeriod, "2 MINUTES");
         try {
             final String[] s = cacheDuration.split(" ", 2);
             long duration = Long.parseLong(s[0]);
             TimeUnit timeUnit = TimeUnit.valueOf(s[1]);
             return timeUnit.toMillis(duration);
         } catch (RuntimeException ex) {
             throw new IllegalArgumentException(Keys.realm.ldap.ldapCachePeriod + " must have format '<long> <TimeUnit>' where <TimeUnit> is one of 'MILLISECONDS', 'SECONDS', 'MINUTES', 'HOURS', 'DAYS'");
         }
     }

 	@Override
 	public void setup(IStoredSettings settings) {
 		this.settings = settings;
 		String file = settings.getString(Keys.realm.ldap.backingUserService, "${baseFolder}/users.conf");
 		File realmFile = GitBlit.getFileOrFolder(file);

 		serviceImpl = createUserService(realmFile);
 		logger.info("LDAP User Service backed by " + serviceImpl.toString());

 		synchronizeLdapUsers();
 	}

 	protected synchronized void synchronizeLdapUsers() {
         final boolean enabled = settings.getBoolean(Keys.realm.ldap.synchronizeUsers.enable, false);
         if (enabled) {
             if (System.currentTimeMillis() > (lastLdapUserSync.get() + getSynchronizationPeriod())) {
             	logger.info("Synchronizing with LDAP @ " + settings.getRequiredString(Keys.realm.ldap.server));
                 final boolean deleteRemovedLdapUsers = settings.getBoolean(Keys.realm.ldap.synchronizeUsers.removeDeleted, true);
                 LDAPConnection ldapConnection = getLdapConnection();
                 if (ldapConnection != null) {
                     try {
                         String accountBase = settings.getString(Keys.realm.ldap.accountBase, "");
                         String uidAttribute = settings.getString(Keys.realm.ldap.uid, "uid");
                         String accountPattern = settings.getString(Keys.realm.ldap.accountPattern, "(&(objectClass=person)(sAMAccountName=${username}))");
                         accountPattern = StringUtils.replace(accountPattern, "${username}", "*");

                         SearchResult result = doSearch(ldapConnection, accountBase, accountPattern);
                         if (result != null && result.getEntryCount() > 0) {
                             final Map<String, UserModel> ldapUsers = new HashMap<String, UserModel>();

                             for (SearchResultEntry loggingInUser : result.getSearchEntries()) {

                                 final String username = loggingInUser.getAttribute(uidAttribute).getValue();
                                 logger.debug("LDAP synchronizing: " + username);

                                 UserModel user = getUserModel(username);
                                 if (user == null) {
                                     user = new UserModel(username);
                                 }

                                 if (!supportsTeamMembershipChanges())
                                     getTeamsFromLdap(ldapConnection, username, loggingInUser, user);

                                 // Get User Attributes
                                 setUserAttributes(user, loggingInUser);

                                 // store in map
                                 ldapUsers.put(username.toLowerCase(), user);
                             }

                             if (deleteRemovedLdapUsers) {
                                 logger.debug("detecting removed LDAP users...");

                                 for (UserModel userModel : super.getAllUsers()) {
                                     if (ExternalAccount.equals(userModel.password)) {
                                         if (! ldapUsers.containsKey(userModel.username)) {
                                             logger.info("deleting removed LDAP user " + userModel.username + " from backing user service");
                                             super.deleteUser(userModel.username);
                                         }
                                     }
                                 }
                             }

                             super.updateUserModels(ldapUsers.values());

                             if (!supportsTeamMembershipChanges()) {
                                 final Map<String, TeamModel> userTeams = new HashMap<String, TeamModel>();
                                 for (UserModel user : ldapUsers.values()) {
                                     for (TeamModel userTeam : user.teams) {
                                         userTeams.put(userTeam.name, userTeam);
                                     }
                                 }
                                 updateTeamModels(userTeams.values());
                             }
                         }
                         lastLdapUserSync.set(System.currentTimeMillis());
                     } finally {
                         ldapConnection.close();
                     }
                 }
             }
         }
     }

 	private LDAPConnection getLdapConnection() {
 		try {
 			URI ldapUrl = new URI(settings.getRequiredString(Keys.realm.ldap.server));
 			String bindUserName = settings.getString(Keys.realm.ldap.username, "");
 			String bindPassword = settings.getString(Keys.realm.ldap.password, "");
 			int ldapPort = ldapUrl.getPort();

 			if (ldapUrl.getScheme().equalsIgnoreCase("ldaps")) {	// SSL
 				if (ldapPort == -1)	// Default Port
 					ldapPort = 636;

 				SSLUtil sslUtil = new SSLUtil(new TrustAllTrustManager());
 				return new LDAPConnection(sslUtil.createSSLSocketFactory(), ldapUrl.getHost(), ldapPort, bindUserName, bindPassword);
 			} else {
 				if (ldapPort == -1)	// Default Port
 					ldapPort = 389;

 				LDAPConnection conn = new LDAPConnection(ldapUrl.getHost(), ldapPort, bindUserName, bindPassword);

 				if (ldapUrl.getScheme().equalsIgnoreCase("ldap+tls")) {
 					SSLUtil sslUtil = new SSLUtil(new TrustAllTrustManager());

 					ExtendedResult extendedResult = conn.processExtendedOperation(
 						new StartTLSExtendedRequest(sslUtil.createSSLContext()));

 					if (extendedResult.getResultCode() != ResultCode.SUCCESS) {
 						throw new LDAPException(extendedResult.getResultCode());
 					}
 				}
 				return conn;
 			}
 		} catch (URISyntaxException e) {
 			logger.error("Bad LDAP URL, should be in the form: ldap(s|+tls)://<server>:<port>", e);
 		} catch (GeneralSecurityException e) {
 			logger.error("Unable to create SSL Connection", e);
 		} catch (LDAPException e) {
 			logger.error("Error Connecting to LDAP", e);
 		}

 		return null;
 	}

 	/**
 	 * Credentials are defined in the LDAP server and can not be manipulated
 	 * from Gitblit.
 	 *
 	 * @return false
 	 * @since 1.0.0
 	 */
 	@Override
 	public boolean supportsCredentialChanges() {
 		return false;
 	}

 	/**
 	 * If no displayName pattern is defined then Gitblit can manage the display name.
 	 *
 	 * @return true if Gitblit can manage the user display name
 	 * @since 1.0.0
 	 */
 	@Override
 	public boolean supportsDisplayNameChanges() {
 		return StringUtils.isEmpty(settings.getString(Keys.realm.ldap.displayName, ""));
 	}

 	/**
 	 * If no email pattern is defined then Gitblit can manage the email address.
 	 *
 	 * @return true if Gitblit can manage the user email address
 	 * @since 1.0.0
 	 */
 	@Override
 	public boolean supportsEmailAddressChanges() {
 		return StringUtils.isEmpty(settings.getString(Keys.realm.ldap.email, ""));
 	}


 	/**
 	 * If the LDAP server will maintain team memberships then LdapUserService
 	 * will not allow team membership changes.  In this scenario all team
 	 * changes must be made on the LDAP server by the LDAP administrator.
 	 *
 	 * @return true or false
 	 * @since 1.0.0
 	 */
 	public boolean supportsTeamMembershipChanges() {
 		return !settings.getBoolean(Keys.realm.ldap.maintainTeams, false);
 	}

 	@Override
 	protected AccountType getAccountType() {
 		 return AccountType.LDAP;
 	}

 	@Override
 	public UserModel authenticate(String username, char[] password) {
 		if (isLocalAccount(username)) {
 			// local account, bypass LDAP authentication
 			return super.authenticate(username, password);
 		}

 		String simpleUsername = getSimpleUsername(username);

 		LDAPConnection ldapConnection = getLdapConnection();
 		if (ldapConnection != null) {
 			try {
 				// Find the logging in user's DN
 				String accountBase = settings.getString(Keys.realm.ldap.accountBase, "");
 				String accountPattern = settings.getString(Keys.realm.ldap.accountPattern, "(&(objectClass=person)(sAMAccountName=${username}))");
 				accountPattern = StringUtils.replace(accountPattern, "${username}", escapeLDAPSearchFilter(simpleUsername));

 				SearchResult result = doSearch(ldapConnection, accountBase, accountPattern);
 				if (result != null && result.getEntryCount() == 1) {
 					SearchResultEntry loggingInUser = result.getSearchEntries().get(0);
 					String loggingInUserDN = loggingInUser.getDN();

 					if (isAuthenticated(ldapConnection, loggingInUserDN, new String(password))) {
 						logger.debug("LDAP authenticated: " + username);

 						UserModel user = null;
 						synchronized (this) {
 							user = getUserModel(simpleUsername);
 							if (user == null)	// create user object for new authenticated user
 								user = new UserModel(simpleUsername);

 							// create a user cookie
 							if (StringUtils.isEmpty(user.cookie) && !ArrayUtils.isEmpty(password)) {
 								user.cookie = StringUtils.getSHA1(user.username + new String(password));
 							}

 							if (!supportsTeamMembershipChanges())
 								getTeamsFromLdap(ldapConnection, simpleUsername, loggingInUser, user);

 							// Get User Attributes
 							setUserAttributes(user, loggingInUser);

 							// Push the ldap looked up values to backing file
 							super.updateUserModel(user);
 							if (!supportsTeamMembershipChanges()) {
 								for (TeamModel userTeam : user.teams)
 									updateTeamModel(userTeam);
 							}
 						}

 						return user;
 					}
 				}
 			} finally {
 				ldapConnection.close();
 			}
 		}
 		return null;
 	}

 	/**
 	 * Set the admin attribute from team memberships retrieved from LDAP.
 	 * If we are not storing teams in LDAP and/or we have not defined any
 	 * administrator teams, then do not change the admin flag.
 	 *
 	 * @param user
 	 */
 	private void setAdminAttribute(UserModel user) {
 		if (!supportsTeamMembershipChanges()) {
 			List<String> admins = settings.getStrings(Keys.realm.ldap.admins);
 			// if we have defined administrative teams, then set admin flag
 			// otherwise leave admin flag unchanged
 			if (!ArrayUtils.isEmpty(admins)) {
 				user.canAdmin = false;
 				for (String admin : admins) {
 					if (admin.startsWith("@")) { // Team
 						if (user.getTeam(admin.substring(1)) != null)
 							user.canAdmin = true;
 					} else
 						if (user.getName().equalsIgnoreCase(admin))
 							user.canAdmin = true;
 				}
 			}
 		}
 	}

 	private void setUserAttributes(UserModel user, SearchResultEntry userEntry) {
 		// Is this user an admin?
 		setAdminAttribute(user);

 		// Don't want visibility into the real password, make up a dummy
 		user.password = ExternalAccount;
 		user.accountType = getAccountType();

 		// Get full name Attribute
 		String displayName = settings.getString(Keys.realm.ldap.displayName, "");
 		if (!StringUtils.isEmpty(displayName)) {
 			// Replace embedded ${} with attributes
 			if (displayName.contains("${")) {
 				for (Attribute userAttribute : userEntry.getAttributes())
 					displayName = StringUtils.replace(displayName, "${" + userAttribute.getName() + "}", userAttribute.getValue());

 				user.displayName = displayName;
 			} else {
 				Attribute attribute = userEntry.getAttribute(displayName);
 				if (attribute != null && attribute.hasValue()) {
 					user.displayName = attribute.getValue();
 				}
 			}
 		}

 		// Get email address Attribute
 		String email = settings.getString(Keys.realm.ldap.email, "");
 		if (!StringUtils.isEmpty(email)) {
 			if (email.contains("${")) {
 				for (Attribute userAttribute : userEntry.getAttributes())
 					email = StringUtils.replace(email, "${" + userAttribute.getName() + "}", userAttribute.getValue());

 				user.emailAddress = email;
 			} else {
 				Attribute attribute = userEntry.getAttribute(email);
 				if (attribute != null && attribute.hasValue()) {
 					user.emailAddress = attribute.getValue();
 				}
 			}
 		}
 	}

 	private void getTeamsFromLdap(LDAPConnection ldapConnection, String simpleUsername, SearchResultEntry loggingInUser, UserModel user) {
 		String loggingInUserDN = loggingInUser.getDN();

 		user.teams.clear();		// Clear the users team memberships - we're going to get them from LDAP
 		String groupBase = settings.getString(Keys.realm.ldap.groupBase, "");
 		String groupMemberPattern = settings.getString(Keys.realm.ldap.groupMemberPattern, "(&(objectClass=group)(member=${dn}))");

 		groupMemberPattern = StringUtils.replace(groupMemberPattern, "${dn}", escapeLDAPSearchFilter(loggingInUserDN));
 		groupMemberPattern = StringUtils.replace(groupMemberPattern, "${username}", escapeLDAPSearchFilter(simpleUsername));

 		// Fill in attributes into groupMemberPattern
 		for (Attribute userAttribute : loggingInUser.getAttributes())
 			groupMemberPattern = StringUtils.replace(groupMemberPattern, "${" + userAttribute.getName() + "}", escapeLDAPSearchFilter(userAttribute.getValue()));

 		SearchResult teamMembershipResult = doSearch(ldapConnection, groupBase, groupMemberPattern);
 		if (teamMembershipResult != null && teamMembershipResult.getEntryCount() > 0) {
 			for (int i = 0; i < teamMembershipResult.getEntryCount(); i++) {
 				SearchResultEntry teamEntry = teamMembershipResult.getSearchEntries().get(i);
 				String teamName = teamEntry.getAttribute("cn").getValue();

 				TeamModel teamModel = getTeamModel(teamName);
 				if (teamModel == null)
 					teamModel = createTeamFromLdap(teamEntry);

 				user.teams.add(teamModel);
 				teamModel.addUser(user.getName());
 			}
 		}
 	}

 	private TeamModel createTeamFromLdap(SearchResultEntry teamEntry) {
 		TeamModel answer = new TeamModel(teamEntry.getAttributeValue("cn"));
 		// potentially retrieve other attributes here in the future

 		return answer;
 	}

 	private SearchResult doSearch(LDAPConnection ldapConnection, String base, String filter) {
 		try {
 			return ldapConnection.search(base, SearchScope.SUB, filter);
 		} catch (LDAPSearchException e) {
 			logger.error("Problem Searching LDAP", e);

 			return null;
 		}
 	}

 	private boolean isAuthenticated(LDAPConnection ldapConnection, String userDn, String password) {
 		try {
 			// Binding will stop any LDAP-Injection Attacks since the searched-for user needs to bind to that DN
 			ldapConnection.bind(userDn, password);
 			return true;
 		} catch (LDAPException e) {
 			logger.error("Error authenticating user", e);
 			return false;
 		}
 	}

     @Override
     public List<String> getAllUsernames() {
         synchronizeLdapUsers();
         return super.getAllUsernames();
     }

     @Override
     public List<UserModel> getAllUsers() {
         synchronizeLdapUsers();
         return super.getAllUsers();
     }

 	/**
 	 * Returns a simple username without any domain prefixes.
 	 *
 	 * @param username
 	 * @return a simple username
 	 */
 	protected String getSimpleUsername(String username) {
 		int lastSlash = username.lastIndexOf('\\');
 		if (lastSlash > -1) {
 			username = username.substring(lastSlash + 1);
 		}

 		return username;
 	}

 	// From: https://www.owasp.org/index.php/Preventing_LDAP_Injection_in_Java
 	public static final String escapeLDAPSearchFilter(String filter) {
 		StringBuilder sb = new StringBuilder();
 		for (int i = 0; i < filter.length(); i++) {
 			char curChar = filter.charAt(i);
 			switch (curChar) {
 			case '\\':
 				sb.append("\\5c");
 				break;
 			case '*':
 				sb.append("\\2a");
 				break;
 			case '(':
 				sb.append("\\28");
 				break;
 			case ')':
 				sb.append("\\29");
 				break;
 			case '\u0000':
 				sb.append("\\00");
 				break;
 			default:
 				sb.append(curChar);
 			}
 		}
 		return sb.toString();
 	}
 }
	/*
	* Copyright 2012 John Crygier
	* Copyright 2012 gitblit.com
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	package com.gitblit;

	import java.io.File;
	import java.net.URI;
	import java.net.URISyntaxException;
	import java.security.GeneralSecurityException;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Map;
	import java.util.concurrent.TimeUnit;
	import java.util.concurrent.atomic.AtomicLong;

	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;

	import com.gitblit.Constants.AccountType;
	import com.gitblit.models.TeamModel;
	import com.gitblit.models.UserModel;
	import com.gitblit.utils.ArrayUtils;
	import com.gitblit.utils.StringUtils;
	import com.unboundid.ldap.sdk.Attribute;
	import com.unboundid.ldap.sdk.ExtendedResult;
	import com.unboundid.ldap.sdk.LDAPConnection;
	import com.unboundid.ldap.sdk.LDAPException;
	import com.unboundid.ldap.sdk.LDAPSearchException;
	import com.unboundid.ldap.sdk.ResultCode;
	import com.unboundid.ldap.sdk.SearchResult;
	import com.unboundid.ldap.sdk.SearchResultEntry;
	import com.unboundid.ldap.sdk.SearchScope;
	import com.unboundid.ldap.sdk.extensions.StartTLSExtendedRequest;
	import com.unboundid.util.ssl.SSLUtil;
	import com.unboundid.util.ssl.TrustAllTrustManager;

	/**
	* Implementation of an LDAP user service.
	*
	* @author John Crygier
	*/
	public class LdapUserService extends GitblitUserService {

	public static final Logger logger = LoggerFactory.getLogger(LdapUserService.class);

	private IStoredSettings settings;
	private AtomicLong lastLdapUserSync = new AtomicLong(0L);

	public LdapUserService() {
	super();
	}

	private long getSynchronizationPeriod() {
	final String cacheDuration = settings.getString(Keys.realm.ldap.ldapCachePeriod, "2 MINUTES");
	try {
	final String[] s = cacheDuration.split(" ", 2);
	long duration = Long.parseLong(s[0]);
	TimeUnit timeUnit = TimeUnit.valueOf(s[1]);
	return timeUnit.toMillis(duration);
	} catch (RuntimeException ex) {
	throw new IllegalArgumentException(Keys.realm.ldap.ldapCachePeriod + " must have format '<long> <TimeUnit>' where <TimeUnit> is one of 'MILLISECONDS', 'SECONDS', 'MINUTES', 'HOURS', 'DAYS'");
	}
	}

	@Override
	public void setup(IStoredSettings settings) {
	this.settings = settings;
	String file = settings.getString(Keys.realm.ldap.backingUserService, "${baseFolder}/users.conf");
	File realmFile = GitBlit.getFileOrFolder(file);

	serviceImpl = createUserService(realmFile);
	logger.info("LDAP User Service backed by " + serviceImpl.toString());

	synchronizeLdapUsers();
	}

	protected synchronized void synchronizeLdapUsers() {
	final boolean enabled = settings.getBoolean(Keys.realm.ldap.synchronizeUsers.enable, false);
	if (enabled) {
	if (System.currentTimeMillis() > (lastLdapUserSync.get() + getSynchronizationPeriod())) {
	logger.info("Synchronizing with LDAP @ " + settings.getRequiredString(Keys.realm.ldap.server));
	final boolean deleteRemovedLdapUsers = settings.getBoolean(Keys.realm.ldap.synchronizeUsers.removeDeleted, true);
	LDAPConnection ldapConnection = getLdapConnection();
	if (ldapConnection != null) {
	try {
	String accountBase = settings.getString(Keys.realm.ldap.accountBase, "");
	String uidAttribute = settings.getString(Keys.realm.ldap.uid, "uid");
	String accountPattern = settings.getString(Keys.realm.ldap.accountPattern, "(&(objectClass=person)(sAMAccountName=${username}))");
	accountPattern = StringUtils.replace(accountPattern, "${username}", "*");

	SearchResult result = doSearch(ldapConnection, accountBase, accountPattern);
	if (result != null && result.getEntryCount() > 0) {
	final Map<String, UserModel> ldapUsers = new HashMap<String, UserModel>();

	for (SearchResultEntry loggingInUser : result.getSearchEntries()) {

	final String username = loggingInUser.getAttribute(uidAttribute).getValue();
	logger.debug("LDAP synchronizing: " + username);

	UserModel user = getUserModel(username);
	if (user == null) {
	user = new UserModel(username);
	}

	if (!supportsTeamMembershipChanges())
	getTeamsFromLdap(ldapConnection, username, loggingInUser, user);

	// Get User Attributes
	setUserAttributes(user, loggingInUser);

	// store in map
	ldapUsers.put(username.toLowerCase(), user);
	}

	if (deleteRemovedLdapUsers) {
	logger.debug("detecting removed LDAP users...");

	for (UserModel userModel : super.getAllUsers()) {
	if (ExternalAccount.equals(userModel.password)) {
	if (! ldapUsers.containsKey(userModel.username)) {
	logger.info("deleting removed LDAP user " + userModel.username + " from backing user service");
	super.deleteUser(userModel.username);
	}
	}
	}
	}

	super.updateUserModels(ldapUsers.values());

	if (!supportsTeamMembershipChanges()) {
	final Map<String, TeamModel> userTeams = new HashMap<String, TeamModel>();
	for (UserModel user : ldapUsers.values()) {
	for (TeamModel userTeam : user.teams) {
	userTeams.put(userTeam.name, userTeam);
	}
	}
	updateTeamModels(userTeams.values());
	}
	}
	lastLdapUserSync.set(System.currentTimeMillis());
	} finally {
	ldapConnection.close();
	}
	}
	}
	}
	}

	private LDAPConnection getLdapConnection() {
	try {
	URI ldapUrl = new URI(settings.getRequiredString(Keys.realm.ldap.server));
	String bindUserName = settings.getString(Keys.realm.ldap.username, "");
	String bindPassword = settings.getString(Keys.realm.ldap.password, "");
	int ldapPort = ldapUrl.getPort();

	if (ldapUrl.getScheme().equalsIgnoreCase("ldaps")) { // SSL
	if (ldapPort == -1) // Default Port
	ldapPort = 636;

	SSLUtil sslUtil = new SSLUtil(new TrustAllTrustManager());
	return new LDAPConnection(sslUtil.createSSLSocketFactory(), ldapUrl.getHost(), ldapPort, bindUserName, bindPassword);
	} else {
	if (ldapPort == -1) // Default Port
	ldapPort = 389;

	LDAPConnection conn = new LDAPConnection(ldapUrl.getHost(), ldapPort, bindUserName, bindPassword);

	if (ldapUrl.getScheme().equalsIgnoreCase("ldap+tls")) {
	SSLUtil sslUtil = new SSLUtil(new TrustAllTrustManager());

	ExtendedResult extendedResult = conn.processExtendedOperation(
	new StartTLSExtendedRequest(sslUtil.createSSLContext()));

	if (extendedResult.getResultCode() != ResultCode.SUCCESS) {
	throw new LDAPException(extendedResult.getResultCode());
	}
	}
	return conn;
	}
	} catch (URISyntaxException e) {
	logger.error("Bad LDAP URL, should be in the form: ldap(s\|+tls)://<server>:<port>", e);
	} catch (GeneralSecurityException e) {
	logger.error("Unable to create SSL Connection", e);
	} catch (LDAPException e) {
	logger.error("Error Connecting to LDAP", e);
	}

	return null;
	}

	/**
	* Credentials are defined in the LDAP server and can not be manipulated
	* from Gitblit.
	*
	* @return false
	* @since 1.0.0
	*/
	@Override
	public boolean supportsCredentialChanges() {
	return false;
	}

	/**
	* If no displayName pattern is defined then Gitblit can manage the display name.
	*
	* @return true if Gitblit can manage the user display name
	* @since 1.0.0
	*/
	@Override
	public boolean supportsDisplayNameChanges() {
	return StringUtils.isEmpty(settings.getString(Keys.realm.ldap.displayName, ""));
	}

	/**
	* If no email pattern is defined then Gitblit can manage the email address.
	*
	* @return true if Gitblit can manage the user email address
	* @since 1.0.0
	*/
	@Override
	public boolean supportsEmailAddressChanges() {
	return StringUtils.isEmpty(settings.getString(Keys.realm.ldap.email, ""));
	}


	/**
	* If the LDAP server will maintain team memberships then LdapUserService
	* will not allow team membership changes. In this scenario all team
	* changes must be made on the LDAP server by the LDAP administrator.
	*
	* @return true or false
	* @since 1.0.0
	*/
	public boolean supportsTeamMembershipChanges() {
	return !settings.getBoolean(Keys.realm.ldap.maintainTeams, false);
	}

	@Override
	protected AccountType getAccountType() {
	return AccountType.LDAP;
	}

	@Override
	public UserModel authenticate(String username, char[] password) {
	if (isLocalAccount(username)) {
	// local account, bypass LDAP authentication
	return super.authenticate(username, password);
	}

	String simpleUsername = getSimpleUsername(username);

	LDAPConnection ldapConnection = getLdapConnection();
	if (ldapConnection != null) {
	try {
	// Find the logging in user's DN
	String accountBase = settings.getString(Keys.realm.ldap.accountBase, "");
	String accountPattern = settings.getString(Keys.realm.ldap.accountPattern, "(&(objectClass=person)(sAMAccountName=${username}))");
	accountPattern = StringUtils.replace(accountPattern, "${username}", escapeLDAPSearchFilter(simpleUsername));

	SearchResult result = doSearch(ldapConnection, accountBase, accountPattern);
	if (result != null && result.getEntryCount() == 1) {
	SearchResultEntry loggingInUser = result.getSearchEntries().get(0);
	String loggingInUserDN = loggingInUser.getDN();

	if (isAuthenticated(ldapConnection, loggingInUserDN, new String(password))) {
	logger.debug("LDAP authenticated: " + username);

	UserModel user = null;
	synchronized (this) {
	user = getUserModel(simpleUsername);
	if (user == null) // create user object for new authenticated user
	user = new UserModel(simpleUsername);

	// create a user cookie
	if (StringUtils.isEmpty(user.cookie) && !ArrayUtils.isEmpty(password)) {
	user.cookie = StringUtils.getSHA1(user.username + new String(password));
	}

	if (!supportsTeamMembershipChanges())
	getTeamsFromLdap(ldapConnection, simpleUsername, loggingInUser, user);

	// Get User Attributes
	setUserAttributes(user, loggingInUser);

	// Push the ldap looked up values to backing file
	super.updateUserModel(user);
	if (!supportsTeamMembershipChanges()) {
	for (TeamModel userTeam : user.teams)
	updateTeamModel(userTeam);
	}
	}

	return user;
	}
	}
	} finally {
	ldapConnection.close();
	}
	}
	return null;
	}

	/**
	* Set the admin attribute from team memberships retrieved from LDAP.
	* If we are not storing teams in LDAP and/or we have not defined any
	* administrator teams, then do not change the admin flag.
	*
	* @param user
	*/
	private void setAdminAttribute(UserModel user) {
	if (!supportsTeamMembershipChanges()) {
	List<String> admins = settings.getStrings(Keys.realm.ldap.admins);
	// if we have defined administrative teams, then set admin flag
	// otherwise leave admin flag unchanged
	if (!ArrayUtils.isEmpty(admins)) {
	user.canAdmin = false;
	for (String admin : admins) {
	if (admin.startsWith("@")) { // Team
	if (user.getTeam(admin.substring(1)) != null)
	user.canAdmin = true;
	} else
	if (user.getName().equalsIgnoreCase(admin))
	user.canAdmin = true;
	}
	}
	}
	}

	private void setUserAttributes(UserModel user, SearchResultEntry userEntry) {
	// Is this user an admin?
	setAdminAttribute(user);

	// Don't want visibility into the real password, make up a dummy
	user.password = ExternalAccount;
	user.accountType = getAccountType();

	// Get full name Attribute
	String displayName = settings.getString(Keys.realm.ldap.displayName, "");
	if (!StringUtils.isEmpty(displayName)) {
	// Replace embedded ${} with attributes
	if (displayName.contains("${")) {
	for (Attribute userAttribute : userEntry.getAttributes())
	displayName = StringUtils.replace(displayName, "${" + userAttribute.getName() + "}", userAttribute.getValue());

	user.displayName = displayName;
	} else {
	Attribute attribute = userEntry.getAttribute(displayName);
	if (attribute != null && attribute.hasValue()) {
	user.displayName = attribute.getValue();
	}
	}
	}

	// Get email address Attribute
	String email = settings.getString(Keys.realm.ldap.email, "");
	if (!StringUtils.isEmpty(email)) {
	if (email.contains("${")) {
	for (Attribute userAttribute : userEntry.getAttributes())
	email = StringUtils.replace(email, "${" + userAttribute.getName() + "}", userAttribute.getValue());

	user.emailAddress = email;
	} else {
	Attribute attribute = userEntry.getAttribute(email);
	if (attribute != null && attribute.hasValue()) {
	user.emailAddress = attribute.getValue();
	}
	}
	}
	}

	private void getTeamsFromLdap(LDAPConnection ldapConnection, String simpleUsername, SearchResultEntry loggingInUser, UserModel user) {
	String loggingInUserDN = loggingInUser.getDN();

	user.teams.clear(); // Clear the users team memberships - we're going to get them from LDAP
	String groupBase = settings.getString(Keys.realm.ldap.groupBase, "");
	String groupMemberPattern = settings.getString(Keys.realm.ldap.groupMemberPattern, "(&(objectClass=group)(member=${dn}))");

	groupMemberPattern = StringUtils.replace(groupMemberPattern, "${dn}", escapeLDAPSearchFilter(loggingInUserDN));
	groupMemberPattern = StringUtils.replace(groupMemberPattern, "${username}", escapeLDAPSearchFilter(simpleUsername));

	// Fill in attributes into groupMemberPattern
	for (Attribute userAttribute : loggingInUser.getAttributes())
	groupMemberPattern = StringUtils.replace(groupMemberPattern, "${" + userAttribute.getName() + "}", escapeLDAPSearchFilter(userAttribute.getValue()));

	SearchResult teamMembershipResult = doSearch(ldapConnection, groupBase, groupMemberPattern);
	if (teamMembershipResult != null && teamMembershipResult.getEntryCount() > 0) {
	for (int i = 0; i < teamMembershipResult.getEntryCount(); i++) {
	SearchResultEntry teamEntry = teamMembershipResult.getSearchEntries().get(i);
	String teamName = teamEntry.getAttribute("cn").getValue();

	TeamModel teamModel = getTeamModel(teamName);
	if (teamModel == null)
	teamModel = createTeamFromLdap(teamEntry);

	user.teams.add(teamModel);
	teamModel.addUser(user.getName());
	}
	}
	}

	private TeamModel createTeamFromLdap(SearchResultEntry teamEntry) {
	TeamModel answer = new TeamModel(teamEntry.getAttributeValue("cn"));
	// potentially retrieve other attributes here in the future

	return answer;
	}

	private SearchResult doSearch(LDAPConnection ldapConnection, String base, String filter) {
	try {
	return ldapConnection.search(base, SearchScope.SUB, filter);
	} catch (LDAPSearchException e) {
	logger.error("Problem Searching LDAP", e);

	return null;
	}
	}

	private boolean isAuthenticated(LDAPConnection ldapConnection, String userDn, String password) {
	try {
	// Binding will stop any LDAP-Injection Attacks since the searched-for user needs to bind to that DN
	ldapConnection.bind(userDn, password);
	return true;
	} catch (LDAPException e) {
	logger.error("Error authenticating user", e);
	return false;
	}
	}

	@Override
	public List<String> getAllUsernames() {
	synchronizeLdapUsers();
	return super.getAllUsernames();
	}

	@Override
	public List<UserModel> getAllUsers() {
	synchronizeLdapUsers();
	return super.getAllUsers();
	}

	/**
	* Returns a simple username without any domain prefixes.
	*
	* @param username
	* @return a simple username
	*/
	protected String getSimpleUsername(String username) {
	int lastSlash = username.lastIndexOf('\\');
	if (lastSlash > -1) {
	username = username.substring(lastSlash + 1);
	}

	return username;
	}

	// From: https://www.owasp.org/index.php/Preventing_LDAP_Injection_in_Java
	public static final String escapeLDAPSearchFilter(String filter) {
	StringBuilder sb = new StringBuilder();
	for (int i = 0; i < filter.length(); i++) {
	char curChar = filter.charAt(i);
	switch (curChar) {
	case '\\':
	sb.append("\\5c");
	break;
	case '*':
	sb.append("\\2a");
	break;
	case '(':
	sb.append("\\28");
	break;
	case ')':
	sb.append("\\29");
	break;
	case '\u0000':
	sb.append("\\00");
	break;
	default:
	sb.append(curChar);
	}
	}
	return sb.toString();
	}
	}