Added option searchScope

Allow users to specify the scope if they wish. Default is still 'sub'.

lib/ldapauth.js

@@ -30,6 +30,8 @@ var format = require('util').format;
  *    adminPassword {String} Password for adminDn.
  *    searchBase {String} The base DN from which to search for users by
  *        username. E.g. 'ou=users,o=example.com'
+ *    searchScope {String} Optional, default 'sub'. Scope of the search, one
+ *        of 'base', 'one', or 'sub'.
  *    searchFilter {String} LDAP search filter with which to find a user by
  *        username, e.g. '(uid={{username}})'. Use the literal '{{username}}'
  *        to have the given username be interpolated in for the LDAP
@@ -60,6 +62,8 @@ function LdapAuth(opts) {
 
   this.log = opts.log4js && opts.log4js.getLogger('ldapauth');
 
+  this.opts.searchScope || (this.opts.searchScope = 'sub')
+
   if (opts.cache) {
     var Cache = require('./cache');
     this.userCache = new Cache(100, 300, this.log, 'user');
@@ -136,7 +140,7 @@ LdapAuth.prototype._findUser = function (username, callback) {
       return callback(err);
 
     var searchFilter = self.opts.searchFilter.replace(/{{username}}/g, username);
-    var opts = {filter: searchFilter, scope: 'sub'};
+    var opts = {filter: searchFilter, scope: self.opts.searchScope};
     if (self.opts.searchAttributes) {
       opts.attributes = self.opts.searchAttributes;
     }