HOW TO: Enable SGC on Internet Information Server

SUMMARY

This article describes how to enable Server Gated Cryptography (SGC) on a computer that is running Internet Information Server (IIS).

NOTE: Microsoft Internet Information Server (IIS) version 4.0 and Microsoft Internet Information Services (IIS) version 5.0 require no special modifications. You must only request an SGC certificate for SGC to be functional with IIS version 4.0 and IIS version 5.0. See the Request an SGC Certificate section for more information.

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Install Schannel.dll and Sgcinst.exe

1. Install the following two executable files:
   • Schannel.dll
   • Sgcinst.exe
   These files are contained in the self-extracting Sgcschannel.exe file. To access this file, visit the following Microsoft Web site:

   ftp://ftp.microsoft.com/bussys/winnt/winnt-public/misc/sgcschannel/

   Copy Sgcschannel.exe in a temporary directory on your Windows NT server. Running this file unpacks the following files:
   
   
   • Schannel.dll
   • Sgcinst.exe
   • License.txt
   • Readme.txt
2. Install this version of Schannel.dll in the %windir%\system32 directory, where %windir% is your Windows installation directory. Typically, this is C:\Winnt. Note that Schannel.dll already exists in this directory. This DLL is loaded at boot time and may not be copied over. To install the SGC Schannel.dll file, you must first rename the existing Schannel.dll file. You can do this from a command prompt or by using Windows Explorer. Microsoft recommends that you rename it to Schannel.sp3 so that it is available if you decide to remove the SGC capability later. After you do this, copy the SGC Schannel.dll file to the %windir%\system32 directory.
3. Copy Sgcinst.exe to a working directory. This can be put in any location; however, Microsoft recommends that you copy it to %windir%\system32, so that it will be in your standard path for executable programs. The application is a utility to help in installing SGC certificates in existing versions of IIS.

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Enable Server Gated Cryptography

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

NOTE: You do not have to add the EnableSGC DWORD value in Microsoft Internet Information Server (IIS) version 4.0 from the NT Option Pack or Microsoft Internet Information Services (IIS) version 5.0 that is included with Windows 2000. In IIS versions 4.0 and 5.0, 1024-bit certificates are supported natively.

1. Click Start, and then click Run.
2. Type Regedt32, and then click OK.
3. In Registry Editor, expand HKEY_LOCAL_MACHINE, and then locate the following subkey:

   System\CurrentControlSet\Control\SecurityProviders

4. Click to select SCHANNEL.
5. On the Edit menu, click New, and then click DWORD Value. A new value appears in the right pane.
6. Type EnableSGC, and then press ENTER.
7. Right-click EnableSGC, and then click Modify.
8. In the Edit DWord Value dialog box, type 1, and then click OK.
9. Click Registry, and then click Exit to close Registry Editor.
10. Restart the computer.

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Request an SGC Certificate

An SGC certificate can be requested by using the process that is described in the IIS Key Manager documentation. Generating a request for an SGC certificate is no different from the process for requesting a standard server identification certificate. Note that the keys that are associated with SGC certificates must be 1024 bits in length.

NOTE: You must also provide any additional information that is requested by the certification authority to validate your application.

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Install the SGC Certificate

The procedure to install the SGC certificate is different for IIS 3.0, IIS 4.0, and IIS 5.0.

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IIS 3.0

Installing an SGC certificate with IIS 3.0 is a two-step process.

VeriSign and other certification authorities that currently issue server identification certificates return the server certificate as a base-64 encoded x.509v3 certificate.

To more effectively control issuance of the SGC certificates, VeriSign has created an intermediate, or issuing, certification authority for SGC certificates. This requires that a certificate chain be returned to the IIS computer. This chain includes both the SGC server certificate and the intermediate certification authority certificate in a base-64 encoded PKCS-7 data structure. With current IIS releases, this must be preprocessed before you install the SGC server certificate by using IIS Key Manager.

Sgcinst.exe performs the required preprocessing. It accepts a base-64 encoded PKCS-7 data structure, installs the intermediate certification authority certificate, and creates a base-64 encoded x.509v3 certificate file that contains only the SGC server certificate. This output file may then be loaded for IIS by using Key Manager.

To install a base-64 encoded PKCS-7 data structure from VeriSign or another certification authority that returns a PKCS-7 certificate chain, follow these steps:

1. Retrieve the PKCS-7 certificate from the certification authority and save it to a temporary directory on the IIS computer. Microsoft recommends that you save this file with a .pk7 file name extension.
2. Run Sgcinst.exe with the PKCS-7 certificate chain file as the input file and a file name to hold the base-64 encoded x.509v3 SGC server certificate as the output file.
   
   To do this, open a command prompt window on the Windows NT Server computer, locate the directory that contains the certificate files, and then type the following command, where input file is the file that contains the base-64 encoded PKCS-7 certificate chain (that is, the file that is received from the certification authority) and output file is the file that will hold the base-64 encoded x.509v3 SGC server certificate:

   sgcinst input fileoutput file

   If the certification authority certificate chain is saved to a file named Sgccert.pk7, the Sgcinst command is as follows:

   sgcinst sgccert.pk7 sgccert.cer

   NOTE: If the input file is not a properly-formatted base-64 encoded PKCS-7, you receive the following error message:
   Error in reading input file: <inputfilename>
3. Install the output file by using IIS Key Manager. See your IIS documentation if you need help with this operation.

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IIS 4.0

For additional information about how to install a certificate on IIS 4.0, click the article number below to view the article in the Microsoft Knowledge Base: back to the top

IIS 5.0

For more information about how to install a certificate on IIS 5.0, see the "Installing the Certificate and Setting Up an SSL Web Site" section of the following Microsoft Knowledge Base article: back to the top

Notes

It is critical that the input file to the Sgcinst program is properly formatted. A properly-formatted input file contains only ASCII printable characters (base-64 encoding ensures this). The following is an example of a correct input file:

   -----BEGIN CERTIFICATE-----
   MIIFHjCCBIegAwIBAgIQTvLRLEwlvniwCz0g3ZENcDANBgkqhkiG9w0BAQQFADCB
   .
   .
   .
   PU/rJbU8kEvm1tCZXJIHQem6
   -----END CERTIFICATE-----
				

where the period (.) characters indicate multiple lines that are similar to the second line. Additional lines of text can come before the line that contains the text "BEGIN CERTIFICATE". For example, an e-mail header that comes before the certificate data does not cause a problem. If you manually save the certificate chain that is returned by the certification authority, make sure to include the lines that contain "BEGIN CERTIFCATE" and "END CERTIFICATE", as indicated.

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