The story has been updated with the following:<p>&quot;Apple issued a new, stronger (SHA-2) Mac App Store certificate in September, before the older (SHA-1) one expired, as planned. The new Mac App Store certificate was using the current, strong SHA-2 algorithm. However, some apps were running receipt validation code using very old versions of OpenSSL that don’t support SHA-2.<p>OpenSSL started supporting SHA-2 in 2005, which is why Apple didn’t foresee this issue.&quot;