diff --git a/default/serverspec/os_spec.rb b/default/serverspec/os_spec.rb
new file mode 100644
index 0000000..5a4d7a7
--- /dev/null
+++ b/default/serverspec/os_spec.rb
@@ -0,0 +1,114 @@
+# encoding: utf-8
+
+require 'spec_helper'
+
+RSpec.configure do |c|
+  c.filter_run_excluding skipOn: backend(Serverspec::Commands::Base).check_os[:family]
+end
+
+# GIS: Req 3.21-4
+describe command('find / -name \'.rhosts\' | wc -l ') do
+  its(:stdout) { should match(/^0/) }
+end
+
+# GIS: Req 3.21-4
+describe command('find / -name \'hosts.equiv\' | wc -l ') do
+  its(:stdout) { should match(/^0/) }
+end
+
+# GIS: Req 3.21-7
+describe file('/etc/shadow') do
+  it { should be_owned_by 'root' }
+end
+
+# GIS: Req 3.21-7
+describe file('/etc/shadow') do
+  it { should be_mode 600 }
+end
+
+# GIS: Req 3.21-8
+describe command('echo $PATH | grep -ci \'\.\'') do
+  its(:stdout) { should match(/^0/) }
+end
+
+# GIS: Req 3.21-8
+describe file('/etc/login.defs') do
+  its(:content) { should match(%r{^ENV_SUPATH\s+PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin}) }
+end
+
+# GIS: Req 3.21-8
+describe file('/etc/login.defs') do
+  its(:content) { should match(%r{^ENV_PATH\s+PATH=/usr/local/bin:/usr/bin:/bin}) }
+end
+
+# GIS: Req 3.21-10
+describe file('/etc/login.defs') do
+  its(:content) { should match(/^UMASK +027/) }
+end
+
+# GIS: Req 3.21-12
+describe 'SUID/ SGID whitelist check' do
+  it 'found only whitelist suid/sgid' do
+    whitelist  = [
+      # whitelist as provided by NSA
+      '/bin/mount', '/bin/ping', '/bin/su', '/bin/umount', '/sbin/pam_timestamp_check',
+      '/sbin/unix_chkpwd', '/usr/bin/at', '/usr/bin/gpasswd', '/usr/bin/locate',
+      '/usr/bin/newgrp', '/usr/bin/passwd', '/usr/bin/ssh-agent', '/usr/libexec/utempter/utempter', '/usr/sbin/lockdev',
+      '/usr/sbin/sendmail.sendmail', '/usr/bin/expiry',
+      # whitelist ipv6
+      '/bin/ping6', '/usr/bin/traceroute6.iputils',
+      # whitelist nfs
+      '/sbin/mount.nfs', '/sbin/umount.nfs',
+      # whitelist nfs4
+      '/sbin/mount.nfs4', '/sbin/umount.nfs4',
+      # whitelist cron
+      '/usr/bin/crontab',
+      # whitelist consolemssaging
+      '/usr/bin/wall', '/usr/bin/write',
+      # whitelist: only SGID with utmp group for multi-session access
+      #            impact is limited; installation/usage has some remaining risk
+      '/usr/bin/screen',
+      # whitelist locate
+      '/usr/bin/mlocate',
+      # whitelist usermanagement
+      '/usr/bin/chage', '/usr/bin/chfn', '/usr/bin/chsh',
+      # whitelist fuse
+      '/bin/fusermount',
+      # whitelist pkexec
+      '/usr/bin/pkexec',
+      # whitelist sudo
+      '/usr/bin/sudo', '/usr/bin/sudoedit',
+      # whitelist postfix
+      '/usr/sbin/postdrop', '/usr/sbin/postqueue',
+      # whitelist apache
+      '/usr/sbin/suexec',
+      # whitelist squid
+      '/usr/lib/squid/ncsa_auth', '/usr/lib/squid/pam_auth',
+      # whitelist kerberos
+      '/usr/kerberos/bin/ksu',
+      # whitelist pam_caching
+      '/usr/sbin/ccreds_validate',
+      # whitelist Xorg
+      '/usr/bin/Xorg',                                              # xorg
+      '/usr/bin/X',                                                 # xorg
+      '/usr/lib/dbus-1.0/dbus-daemon-launch-helper',                # freedesktop ipc
+      '/usr/lib/vte/gnome-pty-helper',                              # gnome
+      '/usr/lib/libvte9/gnome-pty-helper',                          # gnome
+      '/usr/lib/libvte-2.90-9/gnome-pty-helper'                     # gnome
+    ]
+    actual = command('find / -perm -4000 -o -perm -2000 -type f ! -path \'/proc/*\' -print 2>/dev/null | grep -v \'^find:\'').stdout.split(/\r?\n/)
+    (actual - whitelist).count.should be 0
+  end
+end
+
+# GIS: Req 3.21-16
+describe 'Unique uid' do
+  it 'check for unique uids' do
+    actual = command('cat /etc/passwd | cut -d \':\' -f 3').stdout.split(/\r?\n/)
+    hm = actual.each_with_object(Hash.new(0)) { |d, counts| counts[d] += 1 }
+    hm.each do |k, v|
+      str = "User: UID #{k} instances: "
+      ("#{str}#{v}").should eq("#{str}1")
+    end
+  end
+end
diff --git a/default/serverspec/sysctl_spec.rb b/default/serverspec/sysctl_spec.rb
index 5cb6226..bc75d8d 100644
--- a/default/serverspec/sysctl_spec.rb
+++ b/default/serverspec/sysctl_spec.rb
@@ -207,43 +207,3 @@ describe 'ExecShield' do
     its(:value) { should eq 2 }
   end
 end
-
-# GIS: Req 3.21-4
-describe command('find / -name \'.rhosts\' | wc -l ') do
-  its(:stdout) { should match(/^0/) }
-end
-
-# GIS: Req 3.21-4
-describe command('find / -name \'hosts.equiv\' | wc -l ') do
-  its(:stdout) { should match(/^0/) }
-end
-
-# GIS: Req 3.21-7
-describe file('/etc/shadow') do
-  it { should be_owned_by 'root' }
-end
-
-# GIS: Req 3.21-7
-describe file('/etc/shadow') do
-  it { should be_mode 600 }
-end
-
-# GIS: Req 3.21-8
-describe command('echo $PATH | grep -ci \'\.\'') do
-  its(:stdout) { should match(/^0/) }
-end
-
-# GIS: Req 3.21-8
-describe file('/etc/login.defs') do
-  its(:content) { should match(%r{^ENV_SUPATH\s+PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin}) }
-end
-
-# GIS: Req 3.21-8
-describe file('/etc/login.defs') do
-  its(:content) { should match(%r{^ENV_PATH\s+PATH=/usr/local/bin:/usr/bin:/bin}) }
-end
-
-# GIS: Req 3.21-10
-describe file('/etc/login.defs') do
-  its(:content) { should match(/^UMASK +027/) }
-end