diff --git a/lib/vmpooler/api/helpers.rb b/lib/vmpooler/api/helpers.rb
index f76cbce..7575b6d 100644
--- a/lib/vmpooler/api/helpers.rb
+++ b/lib/vmpooler/api/helpers.rb
@@ -54,35 +54,63 @@ module Vmpooler
         return false
       end
 
+      def authenticate_ldap(port, host, user_object, base, username_str, password_str)
+        require 'rubygems'
+        require 'net/ldap'
+
+        ldap = Net::LDAP.new(
+          :host => host,
+          :port => port,
+          :encryption => {
+            :method => :start_tls,
+            :tls_options => { :ssl_version => 'TLSv1' }
+          },
+          :base => base,
+          :auth => {
+            :method => :simple,
+            :username => "#{user_object}=#{username_str},#{base}",
+            :password => password_str
+          }
+        )
+
+        return true if ldap.bind
+        return false
+      end
+
       def authenticate(auth, username_str, password_str)
         case auth['provider']
           when 'dummy'
             return (username_str != password_str)
           when 'ldap'
-            require 'rubygems'
-            require 'net/ldap'
+            ldap_base = auth[:ldap]['base']
+            ldap_port = auth[:ldap]['port'] || 389
 
-            ldap = Net::LDAP.new(
-              :host => auth[:ldap]['host'],
-              :port => auth[:ldap]['port'] || 389,
-              :encryption => {
-                :method => :start_tls,
-                :tls_options => { :ssl_version => 'TLSv1' }
-              },
-              :base => auth[:ldap]['base'],
-              :auth => {
-                :method => :simple,
-                :username => "#{auth[:ldap]['user_object']}=#{username_str},#{auth[:ldap]['base']}",
-                :password => password_str
-              }
-            )
-
-            if ldap.bind
-              return true
+            if ldap_base.is_a? Array
+              ldap_base.each do |search_base|
+                result = authenticate_ldap(
+                  ldap_port,
+                  auth[:ldap]['host'],
+                  auth[:ldap]['user_object'],
+                  search_base,
+                  username_str,
+                  password_str,
+                )
+                return true if result == true
+              end
+            else
+              result = authenticate_ldap(
+                ldap_port,
+                auth[:ldap]['host'],
+                auth[:ldap]['user_object'],
+                ldap_base,
+                username_str,
+                password_str,
+              )
+              return result
             end
-        end
 
-        return false
+            return false
+          end
       end
 
       def export_tags(backend, hostname, tags)
diff --git a/spec/integration/api/v1/config_spec.rb b/spec/integration/api/v1/config_spec.rb
index abcfdb1..e5136d7 100644
--- a/spec/integration/api/v1/config_spec.rb
+++ b/spec/integration/api/v1/config_spec.rb
@@ -1,16 +1,6 @@
 require 'spec_helper'
 require 'rack/test'
 
-module Vmpooler
-  class API
-    module Helpers
-      def authenticate(auth, username_str, password_str)
-        username_str == 'admin' and password_str == 's3cr3t'
-      end
-    end
-  end
-end
-
 describe Vmpooler::API::V1 do
   include Rack::Test::Methods
 
diff --git a/spec/integration/api/v1/status_spec.rb b/spec/integration/api/v1/status_spec.rb
index 2f2f1ba..3ec6cfc 100644
--- a/spec/integration/api/v1/status_spec.rb
+++ b/spec/integration/api/v1/status_spec.rb
@@ -1,16 +1,6 @@
 require 'spec_helper'
 require 'rack/test'
 
-module Vmpooler
-  class API
-    module Helpers
-      def authenticate(auth, username_str, password_str)
-        username_str == 'admin' and password_str == 's3cr3t'
-      end
-    end
-  end
-end
-
 def has_set_tag?(vm, tag, value)
   value == redis.hget("vmpooler__vm__#{vm}", "tag:#{tag}")
 end
diff --git a/spec/integration/api/v1/vm_hostname_spec.rb b/spec/integration/api/v1/vm_hostname_spec.rb
index f5dce5b..f8ade07 100644
--- a/spec/integration/api/v1/vm_hostname_spec.rb
+++ b/spec/integration/api/v1/vm_hostname_spec.rb
@@ -1,16 +1,6 @@
 require 'spec_helper'
 require 'rack/test'
 
-module Vmpooler
-  class API
-    module Helpers
-      def authenticate(auth, username_str, password_str)
-        username_str == 'admin' and password_str == 's3cr3t'
-      end
-    end
-  end
-end
-
 def has_set_tag?(vm, tag, value)
   value == redis.hget("vmpooler__vm__#{vm}", "tag:#{tag}")
 end
diff --git a/spec/integration/api/v1/vm_spec.rb b/spec/integration/api/v1/vm_spec.rb
index 0c14561..387ecd0 100644
--- a/spec/integration/api/v1/vm_spec.rb
+++ b/spec/integration/api/v1/vm_spec.rb
@@ -1,16 +1,6 @@
 require 'spec_helper'
 require 'rack/test'
 
-module Vmpooler
-  class API
-    module Helpers
-      def authenticate(auth, username_str, password_str)
-        username_str == 'admin' and password_str == 's3cr3t'
-      end
-    end
-  end
-end
-
 describe Vmpooler::API::V1 do
   include Rack::Test::Methods
 
diff --git a/spec/integration/api/v1/vm_template_spec.rb b/spec/integration/api/v1/vm_template_spec.rb
index aaabf4a..72fef36 100644
--- a/spec/integration/api/v1/vm_template_spec.rb
+++ b/spec/integration/api/v1/vm_template_spec.rb
@@ -1,16 +1,6 @@
 require 'spec_helper'
 require 'rack/test'
 
-module Vmpooler
-  class API
-    module Helpers
-      def authenticate(auth, username_str, password_str)
-        username_str == 'admin' and password_str == 's3cr3t'
-      end
-    end
-  end
-end
-
 describe Vmpooler::API::V1 do
   include Rack::Test::Methods
 
diff --git a/spec/unit/api/helpers_spec.rb b/spec/unit/api/helpers_spec.rb
index 7e75045..4b36542 100644
--- a/spec/unit/api/helpers_spec.rb
+++ b/spec/unit/api/helpers_spec.rb
@@ -1,4 +1,5 @@
 require 'spec_helper'
+require 'net/ldap'
 
 # A class for testing purposes that includes the Helpers.
 # this is impersonating V1's `helpers do include Helpers end`
@@ -238,4 +239,172 @@ describe Vmpooler::API::Helpers do
     end
   end
 
+  describe '#authenticate' do
+    let(:username_str) { 'admin' }
+    let(:password_str) { 's3cr3t' }
+
+    context 'with dummy provider' do
+      let(:auth) {
+        {
+          'provider': 'dummy'
+        }
+      }
+      it 'should return true' do
+        expect(subject).to receive(:authenticate).with(auth, username_str, password_str).and_return(true)
+
+        subject.authenticate(auth, username_str, password_str)
+      end
+    end
+
+    context 'with ldap provider' do
+      let(:host) { 'ldap.example.com' }
+      let(:base) { 'ou=user,dc=test,dc=com' }
+      let(:user_object) { 'uid' }
+      let(:auth) {
+        {
+          'provider' => 'ldap',
+          ldap: {
+            'host' => host,
+            'base' => base,
+            'user_object' => user_object
+          }
+        }
+      }
+      let(:default_port) { 389 }
+      it 'should attempt ldap authentication' do
+        expect(subject).to receive(:authenticate_ldap).with(default_port, host, user_object, base, username_str, password_str)
+
+        subject.authenticate(auth, username_str, password_str)
+      end
+
+      it 'should return true when authentication is successful' do
+        expect(subject).to receive(:authenticate_ldap).with(default_port, host, user_object, base, username_str, password_str).and_return(true)
+
+        expect(subject.authenticate(auth, username_str, password_str)).to be true
+      end
+
+      it 'should return false when authentication fails' do
+        expect(subject).to receive(:authenticate_ldap).with(default_port, host, user_object, base, username_str, password_str).and_return(false)
+
+        expect(subject.authenticate(auth, username_str, password_str)).to be false
+      end
+
+      context 'with an alternate port' do
+        let(:alternate_port) { 636 }
+        before(:each) do
+          auth[:ldap]['port'] = alternate_port
+        end
+
+        it 'should specify the alternate port when authenticating' do
+          expect(subject).to receive(:authenticate_ldap).with(alternate_port, host, user_object, base, username_str, password_str)
+
+          subject.authenticate(auth, username_str, password_str)
+        end
+      end
+
+      context 'with multiple search bases' do
+        let(:base) {
+          [
+            'ou=user,dc=test,dc=com',
+            'ou=service,ou=user,dc=test,dc=com'
+          ]
+        }
+        before(:each) do
+          auth[:ldap]['base'] = base
+        end
+
+        it 'should attempt to bind with each base' do
+          expect(subject).to receive(:authenticate_ldap).with(default_port, host, user_object, base[0], username_str, password_str)
+          expect(subject).to receive(:authenticate_ldap).with(default_port, host, user_object, base[1], username_str, password_str)
+
+          subject.authenticate(auth, username_str, password_str)
+        end
+
+        it 'should not search the second base when the first binds' do
+          expect(subject).to receive(:authenticate_ldap).with(default_port, host, user_object, base[0], username_str, password_str).and_return(true)
+          expect(subject).to_not receive(:authenticate_ldap).with(default_port, host, user_object, base[1], username_str, password_str)
+
+          subject.authenticate(auth, username_str, password_str)
+        end
+
+        it 'should search the second base when the first bind fails' do
+          expect(subject).to receive(:authenticate_ldap).with(default_port, host, user_object, base[0], username_str, password_str).and_return(false)
+          expect(subject).to receive(:authenticate_ldap).with(default_port, host, user_object, base[1], username_str, password_str)
+
+          subject.authenticate(auth, username_str, password_str)
+        end
+
+        it 'should return true when any bind succeeds' do
+          expect(subject).to receive(:authenticate_ldap).with(default_port, host, user_object, base[0], username_str, password_str).and_return(false)
+          expect(subject).to receive(:authenticate_ldap).with(default_port, host, user_object, base[1], username_str, password_str).and_return(true)
+
+          expect(subject.authenticate(auth, username_str, password_str)).to be true
+        end
+
+        it 'should return false when all bind attempts fail' do
+          expect(subject).to receive(:authenticate_ldap).with(default_port, host, user_object, base[0], username_str, password_str).and_return(false)
+          expect(subject).to receive(:authenticate_ldap).with(default_port, host, user_object, base[1], username_str, password_str).and_return(false)
+
+          expect(subject.authenticate(auth, username_str, password_str)).to be false
+        end
+      end
+
+    end
+
+    context 'with unknown provider' do
+      let(:auth) {
+        {
+          'provider': 'mystery'
+        }
+      }
+      it 'should return false' do
+        expect(subject).to receive(:authenticate).with(auth, username_str, password_str).and_return(false)
+        subject.authenticate(auth, username_str, password_str)
+      end
+    end
+  end
+
+  describe '#authenticate_ldap' do
+    let(:port) { 389 }
+    let(:host) { 'ldap.example.com' }
+    let(:user_object) { 'uid' }
+    let(:base) { 'ou=users,dc=example,dc=com' }
+    let(:username_str) { 'admin' }
+    let(:password_str) { 's3cr3t' }
+    let(:ldap) { double('ldap') }
+    it 'should create a new ldap connection' do
+      allow(ldap).to receive(:bind)
+      expect(Net::LDAP).to receive(:new).with(
+        :host => host,
+        :port => port,
+        :encryption => {
+          :method => :start_tls,
+          :tls_options => { :ssl_version => 'TLSv1' }
+        },
+        :base => base,
+        :auth => {
+          :method => :simple,
+          :username => "#{user_object}=#{username_str},#{base}",
+          :password => password_str
+        }
+      ).and_return(ldap)
+
+      subject.authenticate_ldap(port, host, user_object, base, username_str, password_str)
+    end
+
+    it 'should return true when a bind is successful' do
+      expect(Net::LDAP).to receive(:new).and_return(ldap)
+      expect(ldap).to receive(:bind).and_return(true)
+
+      expect(subject.authenticate_ldap(port, host, user_object, base, username_str, password_str)).to be true
+    end
+
+    it 'should return false when a bind fails' do
+      expect(Net::LDAP).to receive(:new).and_return(ldap)
+      expect(ldap).to receive(:bind).and_return(false)
+
+      expect(subject.authenticate_ldap(port, host, user_object, base, username_str, password_str)).to be false
+    end
+  end
+
 end