Trouble With the Keychain on a Mac

Just as your keyring accesses the places you go, your Mac OS Keychain stores your access information.

The Mac OS X Keychain stores passwords and other private information, including the security certificates that validate online merchant websites and other secured browsing destinations. The Keychain Access utility application enables you to view and manage passwords you've stored through Apple's Safari browser and during other online activities, such as downloading or uploading files through a File Transfer Protocol program. Keychain problems can cause problems in a wide range of Macintosh activities and applications -- but most of the problems can be resolved quickly if you know how.

Secure Web Browsing

Your Keychain stores the certificates issued by the third-party authorities responsible for authenticating secured websites. These certificates assure that the data you send when you communicate securely on the Web remain secure in transit and arrive at a legitimate destination. Whether you use Apple's Safari or another browser such as Firefox, Opera or iCab, your browser consults the certificates stored on your computer to validate that the sites you visit really are what they say they are. If your Keychain data or preferences become corrupted, your browser can't access the certificates it needs and may crash as a result.

Login Details

Because your Keychain stores your username and password information for the secure destinations you visit, problems with your Keychain can spell trouble logging in to sites for which you've stored your access details. If your browser suddenly starts requiring you to enter user names and passwords you know you've stored, these symptoms often point to Keychain problems. Some browsers, including Mozilla Firefox, store passwords in their preferences, so it's important to differentiate between Keychain corruption and browser problems.

Migration Assistant

When you buy a new Mac, Apple's Migration Assistant helps you transfer settings, preferences and applications from your old computer to your new system. This process can reduce the amount of time you spend setting up a new machine and preserve setup details for essential programs, including Apple Mail. Unfortunately, sometimes the migration doesn't succeed completely. If you experience persistent browser- and login-related problems on a new Mac immediately after you've migrated from an old system, your Keychain data may not have transferred correctly.

Operating System Updates

Apple issues periodic updates to current versions Mac OS X, improving functionality, resolving bugs and adding features. Depending on how you apply them and whether they install correctly, these updates can leave bad operating-system behavior in their wake. If you notice Keychain-related problems right after you apply an OS X update, it may be time to tidy up your Keychain preferences.

Repairing Your Keychain

Apple's Keychain Access application includes a Keychain First Aid function. After you bring up the First Aid dialog box in Keychain Access, you can launch a verification procedure that checks for corrupt entries and tries to repair them. If you're left with entries you can't reclaim, or your Mac continues to misbehave after you instigate repairs, you may be forced to delete your Keychain preference file, remove troublesome Keychain entries, substitute files from a current system backup or reset your Keychain to its defaults in Keychain First Aid. Although a reset cures problems with the Keychain itself, it also empties it out, leaving you to recreate your saved items one by one.

References

• Comodo: HTTPS: What It Is and How It Works
• Mac OS X Hints: Corrupt Keychain Entries Can Cause Safari Crashes
• MacFixIt -- CNet Reviews: Tutorial: Keychain Issues; Resolving
• Mac OS X Hints: 10.4: Fix System Keychain Corruption After Migration
• TechRepublic: Snow Leopard Keychain and Password Administration 101
• MacFixIt -- CNet Reviews: Mac OS X 10.4.3 Special Report: Keychain Problems -- Passwords not Recognized, etc. -- How to Fix
• Macworld: Further Cures for a Funky Keychain
• Apple Inc.: Mac OS X: Keychain Access Asks for Keychain "Login" After Changing Login Password