Resolving SSL certificate issues

This article applies to:

• WebMarshal 6.X or 7.X
• HTTPS Content Inspection

Question:

• WebMarshal blocks HTTPS sites
• Message: Certificate Chain is not Trusted

Information:

When WebMarshal HTTPS Content Inspection is enabled, WebMarshal attempts to check the validity of the SSL certificates used by each website.

Validation may be unsuccessful if the required Root Certificate and in some cases Intermediate Certificates are not present in the correct certificate stores on each WebMarshal processing server.

Causes:

1. Newer Windows releases install a very limited set of SSL CA certificates by default.
   • To resolve this issue, you can install updated CA certificates from Windows Update. See Trustwave Knowledge Base article 21016. 
   • Note that WebMarshal does not automatically retrieve root certificates in most cases.
2. In rare cases a required certificate for a site may not be included in the Microsoft certificate package.
   • To resolve this issue, log on to the WebMarshal processing server as an administrator. Using Internet Explorer, browse to the site in question WITHOUT passing through WebMarshal content inspection.
   • When prompted, install (trust) required certificates. Normally, when you browse as an administrator, these certificates will be correctly installed in the computer certificate store and will be available to WebMarshal services.

You can also add certificates or verify the location of certificates using the MMC Certificates snap-in.

1. Run Microsoft Management Console (MMC.exe)
2. Choose to add a snapin and select the Certificates snap-in. Choose to manage certificates for the Computer account. 
3. Add the Certificates snap-in again and choose to manage certificates for the current user account.
   • You can check for the presence of certificates in the Computer section (for instance in Trusted Root Certification Authorities > Certificates.)
   • If required, you can copy certificates from the User section to the Computer section.

After adding certificates, restart the WebMarshal Proxy service. Remember to repeat these steps on each WebMarshal processing server.

Notes:

• WebMarshal 6.8 and above addresses some additional issues with determination of certificate validity.
• From time to time Microsoft includes additional Root Certificates in Windows Update. Trustwave recommends that you schedule update of Root Certificates.
• WebMarshal currently checks certificate status only for the leaf certificate and not for root certificates.