NetScaler SSL A+ Secured VIPs

Below¬†are the steps I followed to score an A+ with Qualys while working on a new XenMobile ūüôā and NetScaler Unified Gateway deployment.

There are some caveats however since Citrix is now delivering TLS1.2 with TLS_FALLBACK-protection across all NetScaler products.  Good right? well if you are running a version below 10.5.57.7.nc you will need to update your NS appliances.

10.5.57.7.nc is available to all NetScaler and NetScaler Gateway customers.  With this release and above, you now can achieve and A+ regardless of the hardware platform including VPX running on your own hypervisor, MPX or SDX .

Environment:

  • Citrix NetsScaler 11.0Build 63.16.nc
  • XenMobile 10.3
  • StoreFront 3.0

Lets gets started:

Bind specific Ciphers to your SSL vServer, then disable RC4 by creating our own Cipher Group.

Please note TLS1-AES-256-CBC-SHA is needed to support older SOCKS-clients such as Receivers prior to 4.2.100 running on Windows and several others.  This includes the XenMobile WorxMail client in STA-mode.

In the future this might change as Citrix moves forward with TLS1.2 support across their products.

set ssl vserver portal_netscaler -tls1 ENABLED
set ssl vserver portal_netscaler -tls11 DISABLED
set ssl vserver portal_netscaler -tls12 ENABLED
set ssl vserver portal_netscaler -ssl2 DISABLED
set ssl vserver portal_netscaler -ssl3 DISABLED
unbind ssl vserver portal_netscaler -cipherName ALL
bind ssl vserver portal_netscaler -cipherName TLS1-ECDHE-RSA-AES256-SHA
bind ssl vserver portal_netscaler -cipherName TLS1.2-ECDHE-RSA-AES-256-SHA384
bind ssl vserver portal_netscaler -cipherName TLS1.2-ECDHE-RSA-AES-128-SHA256
bind ssl vserver portal_netscaler -cipherName TLS1-AES-256-CBC-SHA

Crate a new Cipher Group from the default Cipher Group and disable the RC4 suite as you will be capped to a B.  There are some weaknesses with the  RC4 Cipher Suite that could enable an attacker to decrypt the key stream.  You can read more on how an attack against TLS/RC4 is possible by reviewing this PDF (http://cr.yp.to/talks/2013.03.12/slides.pdf)

add ssl cipher DEFAULT_no_RC4
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1-AES-256-CBC-SHA
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1-AES-128-CBC-SHA
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1.2-AES-256-SHA256
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1.2-AES-128-SHA256
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1.2-AES256-GCM-SHA384
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1.2-AES128-GCM-SHA256
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1-ECDHE-RSA-AES256-SHA
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1-ECDHE-RSA-AES128-SHA
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1.2-ECDHE-RSA-AES-256-SHA384
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1.2-ECDHE-RSA-AES-128-SHA256
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1.2-ECDHE-RSA-AES256-GCM-SHA384
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1.2-ECDHE-RSA-AES128-GCM-SHA256
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1.2-DHE-RSA-AES-256-SHA256
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1.2-DHE-RSA-AES-128-SHA256
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1.2-DHE-RSA-AES256-GCM-SHA384
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1.2-DHE-RSA-AES128-GCM-SHA256
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1-DHE-RSA-AES-256-CBC-SHA
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1-DHE-RSA-AES-128-CBC-SHA
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1-DHE-DSS-AES-256-CBC-SHA
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1-DHE-DSS-AES-128-CBC-SHA
bind ssl cipher DEFAULT_no_RC4 -cipherName TLS1-ECDHE-RSA-DES-CBC3-SHA
bind ssl cipher DEFAULT_no_RC4 -cipherName SSL3-EDH-RSA-DES-CBC3-SHA
bind ssl cipher DEFAULT_no_RC4 -cipherName SSL3-EDH-DSS-DES-CBC3-SHA
bind ssl cipher DEFAULT_no_RC4 -cipherName SSL3-DES-CBC3-SHA

Bind the new SSL Cipher Group to your vServer

bind ssl vserver portal_netscaler -cipherName DEFAULT_no_RC4

The above will get you to an A- Score:

ssl_a_minus

You can also enable Forward Secrecy,¬†with¬†the new firmware it’s now possible to enable PFS for all modern Clients/Browser and receive an A+

Follow the instructions below and score A+

https://blog.cjharms.info/2014/05/enable-forward-secrecy-and-secure.html

ssl_a_plus

Hope this helps ūüôā

Disclaimer:

I do not accept any responsibility or liability for the accuracy, content, completeness, legality, or reliability of the information contained on this website.

 

NetScaler Gateway 11 footer customization

Ran into difficulties customizing a new NetScaler 11 Gateway.  Although I was happy to finally be able to apply themes per NetScaler Gateway vServer, I quickly saw that this new option presents new challenges if you are looking to customize beyond what the themes allow.

Our goal was to add footer information on the front page in order to provide Help Desk contact info, a Citrix Receiver download link and the RSA Self Service portal.   With NS 11, the problem is that the index.html file is no longer constructed the same as it was with 10.x.

Lets understand this a bit more.

With NetScaler Gateway 11, the logon form and pretty much the entire index.html body, is generated by 2 javascript files (gateway_login_view.js and gateway_login_form_view.js).

  1. gateway_login_view.js Рcreates the body and tables for the actual form
  2. gateway_login_form_view.js Рcreates the form itself, username and password fields, domain dropdown box, etc.

This naturally creates a headache if you are use to working with the 10.x firmware.  As with 10.x you can accomplish most of the customization by directly modifying the index.html file, and creating a custom global policy user interface.  On the other hand, this presented a challenge if you had to run multiple Gateway vServers  with a custom UI, and you had to get pretty creative on how to overcome  it.

For NS 11, I read a post where someone was struggling with a similar situation, luckily it pointed me in the right direction.  The post suggested to modify or create a new gateway_login_view.js  and/or gateway_login_form_view.js (you can read the post here).  

Rather than modifying existing code or creating new files then having to deal with responder policies, etc.  I figure I try to do this via the NetScaler Rewrite Policies and Actions to make it look something like the picture below.

ns11_rw_final

Environment:

  • Citrix NetsScaler 11.0Build 63.16.nc
  • StoreFront 3.0
  • RSA 8.1

Let’s get started.

  1. Add links at the bottom of the authentication page, unfortunately rewrite actions have a¬†255 character limit which you can easily bypass¬†by adding “+” to the expression. Click here to view/download the syntax as WordPress messes with it.

2. Enable the EULA box by default:

add rewrite action ns_gtw_eula_checked_action replace_all “http.RES.BODY(120000).SET_TEXT_MODE(ignorecase)” “\”type=\’checkbox\’ checked\”” -pattern “type=\’checkbox\'”
add rewrite policy ns_gtw_eula_checked_pol “HTTP.REQ.URL.CONTAINS(\”gateway_login_form_view.js\”)” ns_gtw_eula_checked_action
bind vpn vserver portal_netscaler -policy ns_gtw_eula_checked_pol -priority 110 -gotoPriorityExpression NEXT -type RESPONSE

3. Enable the Logon Button by default:

add rewrite action ns_gtw_LogonAutoEnable_rw_act replace_all “http.RES.BODY(120000).SET_TEXT_MODE(ignorecase)” “\”\’disabled\’:\’\’\”” -pattern “\’disabled\’:\’disabled\'”
add rewrite policy ns_gtw_LogonAutoEnable_rw_pol “HTTP.REQ.URL.CONTAINS(\”gateway_login_form_view.js\”)” ns_gtw_LogonAutoEnable_rw_act
bind vpn vserver portal_netscaler -policy ns_gtw_LogonAutoEnable_rw_pol -priority 120 -gotoPriorityExpression END -type RESPONSE

Hope this helps ūüôā

Disclaimer:

I do not accept any responsibility or liability for the accuracy, content, completeness, legality, or reliability of the information contained on this website.

Automatic NetScaler Gateway 11 EULA Acceptance

With the new release of Citrix NetScaler 11, we now have the  option to setup an End User License Agreement for users prior to logging in.  After getting the NetScaler Gateway configured and enabling EULA policies, I thought it would be useful to have the check box enabled, and the Log On button turned on by default.

Below are the steps on how to set up Rewrite Policies and Rewrite Actions on the NetScaler to automatically check  the EULA acceptance box, as well as turn on the Log on button.

The default behavior is to have users select the box every time prior to¬†authenticating to the NetScaler Gateway ūüė¶

unchecked_eula

Environment:

  • Citrix NetsScaler 11.0Build 63.16.nc
  • StoreFront 3.0
  • RSA 8.1

Fix:

Enable the check box

add rewrite action ns_gtw_eula_checked_action replace_all “http.RES.BODY(120000).SET_TEXT_MODE(ignorecase)” “\”type=\’checkbox\’ checked\”” -pattern “type=\’checkbox\'”
add rewrite policy ns_gtw_eula_checked_pol “HTTP.REQ.URL.CONTAINS(\”gateway_login_form_view.js\”)” ns_gtw_eula_checked_action
bind vpn vserver name_of_your_ns_gtw_vip -policy ns_gtw_eula_checked_pol -priority 100 -gotoPriorityExpression NEXT -type RESPONSE

Enable the Logon button РBy default this is disabled in the gateway_login_form_view.js file

add rewrite action ns_gtw_LogonAutoEnable_rw_act replace_all “http.RES.BODY(120000).SET_TEXT_MODE(ignorecase)” “\”\’disabled\’:\’\’\”” -pattern “\’disabled\’:\’disabled\'”
add rewrite policy ns_gtw_LogonAutoEnable_rw_pol “HTTP.REQ.URL.CONTAINS(\”gateway_login_form_view.js\”)” ns_gtw_LogonAutoEnable_rw_act
bind vpn vserver name_of_your_ns_gtw_vip -policy ns_gtw_LogonAutoEnable_rw_pol -priority 110 -gotoPriorityExpression NEXT -type RESPONSE

Final result – The Checkbox and Logon box will be enabled when users go to the NetScaler Gateway site.

Disclaimer:

I do not accept any responsibility or liability for the accuracy, content, completeness, legality, or reliability of the information contained on this website.

Provide Citrix Receiver download link on NetScaler Gateway authentication page based on Client OS

While working on a new StoreFront/NetScaler Gateway implementation, I was asked to provide a Citrix Receiver link on the NetScaler Gateway authentication page, although I thought this was a pretty simple task, I figure we would make this fancier and detect the Client OS then provide the proper Citrix Receiver the company wanted to deploy.

Before you get started, I suggest reading the articles below.  These guides will give you a great understanding on the steps necessary to modify the NetScaler Gateway logon page.

Remember that the changes will be lost if the NetScaler reboots, so please make sure to follow the steps below after you are done.

Apply customization:

Putty in to NS

  • shell
  • mkdir /var/ns_gui_custom
  • cd /netscaler
  • tar -cvzf /var/ns_gui_custom/customtheme.tar.gz ns_gui/*

Now apply the package to your AGEE sites

  • In the configuration utility, under¬†the Configuration tab, expand ‚ÄúNetScaler Gateway‚ÄĚ and then click ‚ÄúGlobal Settings‚Äú.
  • In the details pane, under Settings, click Change global settings.
  • In Global NetScaler Gateway Settings, click the Client Experience tab.
  • Next to UI theme, click Custom and then click OK.
  • Save NS config and done!

Read these before getting started:

Environment:

  • Citrix NetsScaler 10.5 Safe Harbor Build 56.22.nc
  • StoreFront 2.6

Lets get started ūüôā

Goals:

  • Create Receiver Download link based on OS (Windows, Mac, iOS and Linux)
  • Create Support Contact information
  • Create footer information

The final look (had to blur company info, logos and links)

final_page

Back up the index.html file under /var/netscaler/gui/vpn.  In this case this deployment is already set up with the StoreFront 3.0 look and feel, so I just need to mess with the index.html

Around line 15.  Lets add some CSS so we can then use to display the text.  Your code should look like this

<style type=”text/css”>
body
{
display : none;
visibility: hidden;
}

#auth-footer-disclaimer-wrapper {
width: 100%;
position: absolute;
bottom: 10px;
text-align: center;
}

#auth-footer-disclaimer {
color: white;
width: 80%;
margin: 0px auto;
font-family: tahoma, helvetica, arial;
font-size: 7pt;
}

#auth-footer-help-info {
color: white;
width: 80%;
margin: 0px auto;
font-family: tahoma, helvetica, arial;
font-size: 10pt;
}
#auth-footer-qrc-links {
color: white;
position: relative;
text-align: center;
font-family: source sans pro, segoe ui, arial;
font-size: 10pt;
padding: 10px;
}

#auth-footer-qrc-links a, a:link, a:visited {
color: white;
text-decoration: underline;
}

#auth-footer-qrc-links a:hover {
color: white;
text-decoration: underline;
}

</style>

Now lets create that java script for browser detection script to detect the presentation of ICA client download links

Inset this around line 87 after

function setFocus(obj)
{
if (obj != null) {
obj.focus();
}
}

You will need to insert the javascript here. ¬†However WordPress is not allowing me to display it ūüė¶

Take a look at the index.html file link

Now around line 236, look for

div id=”logonbelt-bottomshadow”

Then inset the code to call the CSS you used as well as the link and text you defined before

<!– Display Citrix Receiver link // –>
<div id=”auth-footer-qrc-links”>

document.write(dlLink);

Here is the entire Index.html file

Disclaimer:

I do not accept any responsibility or liability for the accuracy, content, completeness, legality, or reliability of the information contained on this website.

 

 

NetScaler Gateway front page √† la StoreFront 3.0

Below are the steps on how to brand the NetScaler Gateway front page to look similar to the new release of StoreFront 3.0.

If you are enabling the VPN (AKA Client Choices), then I also suggest you read my Citrix NetScaler Gateway Client Choices branding post.  And finaly take a peek at my previous post on Customizing Citrix NetScaler Gateway 10.5 logon page with Dual Factor Authentication,

Please note I tested this on several 10.1 Firmware Releases as well as the 10.5 Safe Harbor Build 56.22.nc release.

Environment 

  • Citrix NetsScaler 10.5 Safe Harbor Build 56.22.nc
  • StoreFront 2.6

Lets take a look at the Default Logon Page to be utilized with Citrix Web Interface 5.x (not 5.4) to match the carbon-black look and feel

ns_gateway_default

Ok now lets make this Green Bubble, once you apply the changes, you will notice the files will change under /var/netscaler/gui/vpn

Head over to your NS management IP:

Go under NetScaler > NetScaler Gateway > Global Settings and click on “Change Global settings”
Now click on the “Client Experience” Tab and change the “UI Theme” from “Default” to “Green Bubble”

This will update the authentication page to the horrendous looking Bubble Green theme

ns_gateway_green

Now lets have some fun ūüėõ

Backup the entire  /var/netscaler/gui/vpn directory

Since I am using second factor authentication for this roll out, we need to modify the login.js file in order to customize the password fields

ns_password

 

Around line 89 you will see the showpwd function, this will need to be manipulated so it does not displays the word “Password: 1” but rather something as simple as “Password:” or whatever you like. ¬†Your code should look this this.

function ns_showpwd_greenbubble()
{
var pwc = ns_getcookie(“pwcount”);
document.write(‘<div class=”field CredentialTypepassword”><div class=”left”><label class=”label plain”><SPAN>’ + _(“Password”));

// Original password settings with Password: 1
// if ( pwc == 2 ) { document.write(‘&nbsp;1’); }
// Removes password value 1 when using dual factor

if ( pwc == 2 ) { document.write(‘&nbsp;’); }
document.write(‘:</SPAN></label></div>’);
document.write(‘<div class=”right”><input class=”prePopulatedCredential” autocomplete=”off” spellcheck=”false” type=”Password” title=”‘ + _(“Enter password”) + ‘” name=”passwd” size=”30″ maxlength=”127″></div></div>’);
if ( pwc == 2 ) {
document.write(‘<div class=”field CredentialTypepassword”><div class=”left”><label class=”label plain”><SPAN>’ + _(“Password2″) + ‘</SPAN></label></div><div class=”right”><input class=”prePopulatedCredential” autocomplete=”off” spellcheck=”false” type=”Password” title=”‘ + _(“Enter password”) + ‘” name=”passwd1″ size=”30″ maxlength=”127″></div></div>’);
}
UnsetCookie(“pwcount”);
}

Now lets modify the “Password 2:” entry by heading over to the¬†“en.xml” under the “resources” folder

Around line 83 change the “Password2″ String to something like “RSA Code”

<String id=”Password2″>RSA Code:</String>

Ok that takes care of the Password fields ūüôā

ns_password2

 

Now lets modify some CSS. ¬†Head over to “ctxs.authentication.css” in the “css” folder

Lets add that funky shadow border StoreFront 2.6 has, which by default it is missing

ns_no_shadow_border

 

Around line look for “#logonbelt-topshadow” and “#logonbelt-bottomshadow” and lets add the shadow pics StoreFront uses.

Your code should look like this when you are done, make sure you copy those files from the StoreFront servers under the media directory on your StoreFront site (Ex:¬†c:\inetpub\wwwroot\Citrix\NetScalerGatewayWeb\media\) copy both¬†Screen_shadow_top.png and¬†Screen_shadow_bottom.png to the “media”folder on your NS.

#logonbelt-topshadow {
background: url(“../media/Screen_shadow_top.png”) no-repeat transparent;
position: relative;
top: 205px;
margin: 0 auto;
width: 1009px;
height: 15px;
}

#logonbelt-bottomshadow {
background: url(“../media/Screen_shadow_bottom.png”) no-repeat transparent;
position: relative;
bottom: 0;
margin: 205px auto 0;
width: 1009px;
height: 15px;
}

Now lets change that darn green vertical bar, which is actually a pic that Citrix calls in their code.

ns_greenbar

Look for “#logonbox-container”, you will need to crank up that Photoshop or whatever image utility you use, and paint it the color you like, then point to the new file. ¬†As you can tell Citrix is using a file called “VerticalGreenBarOnly.png” under the media folder. ¬†Make changes and upload the new pic file and make a call to it in the CSS. ¬†Your code should look like this.

#logonbox-container
{
/* background: url(“../media/VerticalGreenBarOnly.png”) repeat-y scroll 0 0 transparent; */
background: url(“../media/VerticalPurpleBarOnly.png“) repeat-y scroll 0 0 transparent; */
min-height: 230px;
margin: auto;
min-width: 654px;
position: relative;
top: 205px;
}

Now lets use that StoreFront 3.0 background file, head over to your X1 installaton and grab the bg_x1.jpg file under your Sites deployment (Ex: C:\inetpub\wwwroot\Citrix\PrivateCloudWeb\media)

Upload bg_x1 to the media folder on your NS and make a call to it under “#authentication” ¬†Your code should look like this when you are done.

#authentication
{
background-image: url(‘../media/bg_x1.jpg’);
background-size: cover;
height: 100%;
width: 100%;
}

Now lets go after that logo.  You will need to mess around with the height and width and top settings based on the size of the log you are using.

Upload your company log to the media folder on NS, then head to the “#logonbox-logoimage” section and make a call to it. ¬†Your code will look something like this when you are done.

#logonbox-logoimage
{
background-image: url(“../media/company_logo.png”);
border: 0 none;
float: right;
height: 43px;
position: absolute;
right: 69%;
top: 92px;
width: 354px;
}

Now lets make this work with IE11, and force the index.html file to render with IE9. Lets also change the default “NetScaler Gateway” Tab to match your company name. ¬†In my case I am also loading a custom ico file when you save the link.

Open the index.html file and modify the code so it looks something like this

<HEAD><TITLE>Name of your Company</TITLE>

<META http-equiv=”X-UA-Compatible” content=”IE=EmulateIE9″ />

<link rel=”SHORTCUT ICON” href=”/vpn/images/company_icon.ico” type=”image/vnd.microsoft.icon”>

Almost done, except that the background picture you used “bg_x1.jpg” is not dynamic, meaning it will display a static size and will not re-size on the screen based on the browser size, and you get this very annoying scroll bar at the bottom right.

ns_non_dynamic_back

The reason is Citrix is using 9px as a margin to allocate that green bar “background: url(“../media/VerticalGreenBarOnly.png”) repeat-y scroll 0 0 transparent;” So lets delete that margin and also make the background image cover the browser screen. ¬†Your code should¬†look like this

#logonbox-innerbox {
background: url(“../media/Screen_SemiTranslucent.png”);
display: table;
height:242px;
position: relative;
width: 100%;
/* margin-left: 9px; Remove margin on the right. Makes the front page scroll ūüė¶ */
}

#authentication
{
background-image: url(‘../media/bg_x1.jpg’);
background-size: cover;
height: 100%;
width: 100%;
}

We are done.  End result will look something like this.  Hope this helps and please remember to do the following or your will lose your work when the Netscaler is rebooted

Open Putty and log in as nsroot, then type (Note the name of the compressed file, this needs to match “customtheme.tar.gz“)

  • shell
  • mkdir /var/ns_gui_custom
  • cd /netscaler
  • tar -cvzf /var/ns_gui_custom/customtheme.tar.gz ns_gui/*

Now apply the package to your AGEE sites

  • In the configuration utility, under¬†the Configuration tab, expand ‚ÄúNetScaler Gateway‚ÄĚ and then click ‚ÄúGlobal Settings‚Äú.
  • In the details pane, under Settings, click Change global settings.
  • In Global NetScaler Gateway Settings, click the Client Experience tab.
  • Next to UI theme, click Custom and then click OK.
  • Save NS config and done!

ns_final

 

Disclaimer:

I do not accept any responsibility or liability for the accuracy, content, completeness, legality, or reliability of the information contained on this website.