Safari prompts multiple times for my certificate

Question

Safari prompts me multiple times for my certificate, but never lets me access the certificate-protected page. This occurs on some MIT certificate-protected websites, but not others. How can I resolve this?

Answer

Some of MIT's certificate-protected sites require CertAid. If you already have CertAid installed, and are seeing multiple prompts for your certificate, try the following steps:

(note: before you begin, make sure that you don't have any expired or duplicate certificates in addition to your valid one.)

1. Download the CertAid tool from:
   http://web.mit.edu/swrt/certaid.html
   but don't run it just yet.
2. Quit Safari
3. Go to Applications > Utilities > Keychain Access
4. In the Category section, click on All Items.
5. Select the column label "Kind" to sort the items by kind.
6. Delete all identity preferences. (Alternate: delete all identity preferences for MIT sites.)
7. Run the CertAid tool, choosing Update List to download a current list of websites to configure.
8. Clear the cache in Safari (Safari >> Empty Cache)
9. Close all Safari windows
10. Relaunch Safari and try again to access the site.