Solutions for InfoPath web service connection problems behind SSL enabled TMG or hardware Load Balancer in Sharepoint 2010

Hi Everyone,

In this article i will explain a well known problem about web service connection problem on your sharepoint servers behind SSL offload Load Balancer or TMG reverse proxy enabled topologies.

What is SSL Offload and Acceleration:
Depending on the workload, processing the encryption and authentication requirements of an SSL request can become a major part of the demand on the Web Server’s CPU and as the demand increases the users will see slower response times. To remove this demand from the Web Server a Load Balancer may be used to terminate the SSL at the Load Balancer. Some Load Balancer appliances include specialized hardware to process SSL. When a Load Balancer terminates the SSL connections the requests are converted from HTTPS to HTTP in the Load Balancer before being passed to the Web Server. So long as the Load Balancer itself is not overloaded this feature will not noticeably degrade the performance perceived by the end users.

For More information about Reverse proxy publishing: http://technet.microsoft.com/en-us/library/cc261814(office.12).aspx
So lets explain our topology. We have 2 WFE server and a Hardware Load Balancer.

WFE01 : Sharepoint Web Front End Server  which serving blog.bugrapostaci.com and our custom web service
/_layouts/CustomWebService/myservice.asmx
IP: 192.168.10.2

WFE02: Sharepoint Web Front End Server  which serving blog.bugrapostaci.com and our custom web service
/_layouts/CustomWebService/myservice.asmx
IP:192.168.10.3

HLB : Hardware load balacer device which is configured SSL Offload.

for this topology needed configuration fallowing Alternate Access Mappings …

Internal URL:  https://blog.bugrapostaci.com
Zone: Default
Public URL for zone:
https://blog.bugrapostaci.com  

Internal UR: http://blog.bugrapostaci.com  
Zone: Default
Public URL for zone: https://blog.bugrapostaci.com  

For more information about How do I configure a load balancer to accept only SSL requests please read fallowing article:
http://www.sharepointpromag.com/article/sharepoint/configure-a-load-balancer-to-accept-only-ssl-requests
Ok. If you establish your AAM correctly, you can able to browse our sharepoint site well. First of all all client computer in your domain must use HTTPS protocol for browsing
our portal even if they write http://blog.bugrapostaci.com it will redirected to SSL httpS://blog.bugrapostaci.com according AAM configuration. But on the server’s browsers i mean if you connect to WFE1 or WFE2 you can not browse the site with using SSL because there is not any SSL implementation configured on your sharepoint servers.(also this is which we want for performace) unless redirect to outside port of HLB which is mostly prohibited for security. So you can browse your portal using HTTP protocol only on WFE server’s browsers reversly client action.

Ok so far so good What is the problem ?
You have a developer machine outside of the server farm and can able to create Infopath Web Forms using Sharepoint Designer or Infopath 2010  .And they can publish their form to sharepoint and see all forms are working correctly by instead of SSL communication. But what if one of the InfoPath form needs to connect a web service which is already publishing on our sharepoint portal “/_layouts/CustomWebService/myservice.asmx” it can be built in sharepoint web service too but in this scenario is customized asmx file.

You will get the 5566 connection problem when you try to open this infopath form after publish to server.

Why ?
Because when you working with your infopath form in InfoPath2010 (in client machine) you can able to configure your web service connection with HTTPS.
For example https://blog.bugrapostaci.com/_layouts/CustomWebService/myservice.asmx
if you test form your client computer’s browser you can see WSDL without any problem.
yes on client machine you can able to reach this service without any error and develop your form as you want.But After you deploy/publish it to sharepoint server the form
(also publish ends successfully)  and assume that the user request this form ,wfe server process the pipeline and requests to connect webservice for getting data not the client !!! So as i told you before there is not any SSL connection can be done in server network but your published web service url is starting with https , and all requestes are redirected HTTPS according Alternate Access Mappings. You got the problem 🙂

So what we could do for resolving this issue

The first solution 

you can configure a rule for HLB (if it is configurable) that server request can over through directly load balancer by using https .mean you should allow the server requests pass through HLB even if requester machine itself. (But this time you may encounter with double-hop scenario).But somehow if you can not configure your LB or prohibited by security reson or faced with double hop  you need second solution which is a little complicated.

The Second Solution

1)  You can add another Host header to your site from IIS console which is using protocol of HTTP
http://myblogserviceDo not add any AAM record for it. If you create an AAM record it will rewrite your service url as https again.

2) Adding host file record of all request can be redirected to same machine (for preventing double hop)
For WFE1  ->   192.168.10.2    wfe1
For WFE2  ->  192.168.10.3    wfe2

3) Give only the developer machines to direct access http://myblogservice for able to create their infopath form correctly.

4) Enable Cross Domain options for InfoPath Services.
Central Administration –> General Application Settings –> InfoPath Forms Services –> Configure InfoPath Forms Services:
Note :If this is an administrator-approved form template, the security level of the form must be set to full trustAbout  InfoPath Security Model:
http://msdn.microsoft.com/en-us/library/bb251020(v=office.12).aspx

5) Create and use Data Connection Library for storing infopath connection information
How to: Create and Use a Data Connection Library
http://msdn.microsoft.com/en-us/library/ms772101.aspx

6) Configure your InfoPath forms as use connections udcx files. And use your new host header for connecting web service like
http://myblogservice/_Layouts/CustomWebService/myservice.asmx

7) And publish your forms.

If you completed all steps correctly, when a user browse an infopath form from your site one of wfe server handle the request by using https when the server need to connect
web service it will use http protocol which can be used by servers and you can able to browse your infopath for correctly without any connection error.

Advertisements

how to remove unnecessery handler mappings from Sharepoint 2010 web application for security purpose

This article explains how to restrict or remove unnecessary handler mappings for  Microsoft SharePoint Foundation web application in the Integrated Request Pipeline of Internet Information Services (IIS) .

As you know Sharepoint has modifed the pipeline for more information about Why Sharepoint modifing the request pipeline please read this topic :
http://msdn.microsoft.com/en-us/library/ee537834.aspx

For a general web application you can modify pipleline using:

  • Pipeline Changes at the ASP.NET Framework Level: Sharepoint  does not change any thing for this level that mean sharepoint makes no changes to the machine.config file or the global web.config file.
  • Pipeline Changes at the IIS Configuration Level : The modifications on applicationhost.config file.This file is located in the %WinDir%\System32\inetsrv\config\ directory and it contains registrations of the IIS Web sites and application pools on the server, as well as some settings that apply to all Web applications on the Web server. The settings in applicationhost.config are primarily oriented to the parts of the pipeline that are contributed by IIS, whereas the machine.config and the global web.config files contain settings that are primarily oriented to the parts of the integrated request pipeline that are contributed by ASP.NET.
  • Pipeline Changes at the SharePoint Web Application Level: The modifications on web.config files.
  • Pipeline Changes at the Directory Level : The modifications on directory levels still using web.config files.Particular physical or virtual directories in an IIS Web site can also have their own web.config file to add new settings or override inherited settings. The new settings and overrides, of course, apply only to HTTP requests for resources located within the directory and its subdirectories.

Important ! :In this article scope of “Pipeline Changes at the IIS Configuration Level” so get backup your applicationhost.config file before do anything in %WinDir%\System32\inetsrv\config\

Bellowed configuration is for standart sharepoint web application so if you have some custom codes that need extra handler please add needed handlers to list.

For removing handler mappings

1) open your IIS console.
2) select your Sharepoint Web Application
3) Click Handler Mappings.

And Remove unneceserry handler mappings by selecting and clicking remove button on iis console.

 The handlers in  picture below are the needed ones so don’t delete them.

So sharepoint is not use any .net framework 4.0 components and the other iis default isapi extentions.
Always make a test that your site is working correctly. For testing use these starting points:

  • Test Pages
  • Test System Pages
  • Test File Upload
  • Test Search
  • Test Sharepoint Designer Connection
  • Add your custom test items.

see you next articles.