Microsoft KB Archive/839913

= When you use a Outlook Web Access client to access an Exchange Server 2003 computer, you may receive an &quot;HTTP 403.4&quot; error message =

Article ID: 839913

Article Last Modified on 10/25/2007

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APPLIES TO


 * Microsoft Exchange Server 2003 Enterprise Edition
 * Microsoft Exchange Server 2003 Standard Edition

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Important This article contains information about how to modify the registry. Make sure to back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows registry





SYMPTOMS
When you use a Microsoft Outlook Web Access client computer to access a Microsoft Exchange Server 2003 computer that is configure for Forms Based Authentication (FBA), you may receive the following error message:

The page must be viewed over a secure channel

The page you are trying to access is secured with Secure Sockets Layer (SSL).

Please try the following:

Type https:// at the beginning of the address you are attempting to reach and press ENTER.

HTTP Error 403.4 - Forbidden: SSL is required to view this resource.

Internet Information Services (IIS)



CAUSE
This problem occurs if the OWA client accesses the Exchange 2003 computer through a third-party firewall server. For example, you use the following URL:

https:// /exchange

The SSL hardware accelerator that is installed in the third-party firewall decrypts the request and then passes the following URL to the Exchange 2003 computer:

http:// /exchange

Then, Exchange 2003 returns the following URL to the OWA client:

http:// /exchange

When the OWA client uses this URL to log on to the Exchange 2003 computer, you receive an &quot;HTTP Error 403.4&quot; error message.



RESOLUTION
Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

The hotfix for Exchange 2003 without Service Pack 1
A supported hotfix is now available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:

http://go.microsoft.com/?linkid=6294451

Note If additional issues occur or any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. To create a separate service request, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

File information
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.    Date         Time   Version            Size    File name --  19-Apr-2004  06:49  6.5.6980.82        67,584  Owaauth.dll

The hotfix for Exchange 2003 Service Pack 1
A supported hotfix is now available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:

http://go.microsoft.com/?linkid=6294451

Note If additional issues occur or any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. To create a separate service request, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

File information
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.     Date         Time   Version            Size    File name --  15-Jun-2004  17:07  6.5.7232.1         67,584  Owaauth.dll You must create the SSLOffloaded registry entry for both hotfixes to work. To do this, follow these steps:
 * 1) Click Start, click Run, type regedt32.exe, and then click OK.
 * 2) Locate, and then click the following registry subkey:
 * 3) On the Edit menu, point to New, and then click DWORD Value.
 * 4) Type SSLOffloaded for the name of the new registry entry.
 * 5) Right-click SSLOffloaded, and then click Modify.
 * 6) Type 1 in the Value Data box, click Decimal, and then click OK.
 * 7) Close Registry Editor.

If you are using front-end servers and back-end servers, you only have to add this registry entry to the front-end server. If you are using only back-end servers, you have to add this registry entry to the back-end server.



WORKAROUND
To work around this problem, manually change the URL. To do this, type https:// /exchange/ in the Address bar in Microsoft Internet Explorer.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.



MORE INFORMATION
If you monitor the traffic that is captured between the third-party firewall and the Exchange 2003 computer, you notice a frame that is sent from the Exchange 2003 computer to the third-party firewall. This frame contains the following information about the location of the logon.asp page:

HTTP/1.1 302 Moved Temporarily Location:

Set-Cookie: sessionid=; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT

Set-Cookie: cadata=; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT

Connection: close

Content-Length: 0

Note This problem does not occur if Exchange 2003 is configured with Microsoft Internet Security and Acceleration (ISA) Server 2000 or with Microsoft Internet Security and Acceleration Server 2004. ISA Server can send a corrected URL back to the OWA client.

