Apple isn't as forgetful as we had thought when one of the company's security certificates expired and left users locked out of their Mac apps.

That little incident caused a small uproar online especially on Twitter when users had to either delete and reinstall their apps, or, when that didn't work, restart their Macs.

Most of that has blown over by now though, and Apple just released a statement saying that it had after all expected that specific certificate to fail. In a letter released to developers, the company apologized "for any inconvenience brought to [them] and [their] customers."

If Apple had, in fact, known that the security certificate was going to expire beforehand, what happened then? In the email to developers, the Cupertino-based company stated that it had actually issued a new security certificate for the one that was going to expire back in September. This new security certificate used a stronger form of security (SHA-2) than the old security certificate's outdated SHA-1 hashing algorithm.

Unfortunately, as we all know by now, users still experienced errors when the switcheroo between the two security certificates occurred. Either users were confronted with a caching issue with the Mac App store so they were forced to restart their Macs an reauthenticate with the Mac App Store to clear out the old cache, or apps were using an older version of OpenSSL that didn't support the newer SHA-2 security feature.

The first issue irked a lot of users especially those who couldn't remember their passwords because they had stored them in 1Password which was an app affected by the mix-up at the Mac App Store. Even when some users had restarted their Mac and signed in all over again into the Mac App Store, they still continued to face problems with their apps. As for the second issue, Apple says it has already reverted the SHA-2 certificate back to a newer SHA-1 certificate, but considering the circumstances, that may even seem like a step backward in terms of security.

Nonetheless, Apple comments in the email that "most of the issues are now resolved" but some users may still encounter a glitch or two. At best, the company says it'll have a patch ready for the next OS X update that should finally clear things up.

Photo: Cristiano Betta | Flickr