I’m almost done with my deeper review of the firewall, but discovered something ugly in the process of podcasting and firewall testing.
If you enable the firewall in the “Set access for specific services and applications” mode, Leopard digitally signs applications on launch that aren’t already signed via Apple’s mechanism.
If that application happens to change during runtime, as Skype seems to, the signature no longer matches and the application won’t run. There are no dialogs or warnings- the icon just dances on the dock for a few bounces then disappears.
I went to podcast last night and had this happen. Reinstalling it fixed the problem, but then it hit again today. I looked in my console and saw the following:
Nov 1 16:09:34 CrashBook [0x0-0x27027].com.skype.skype[387]: Check 1 failed. Can’t run Skype
Googling that error returns some threads in Skype forums that indicate this is a known issue related to the firewall and code signing.
A reinstall fixes it, but this is, obviously, a bit of a problem.
I’m somewhat surprised this hasn’t made the rounds yet.
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16 Replies to “Leopard Firewall + Code Signing Breaks Skype (And Other Applications)”
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[…] Originally Posted by analogika Maybe I”m being stupid, but what the hell does keeping the port for Skype open in the firewall by default (by designating Skype an "essential service") have to do with code signing? Leopard Firewall + Code Signing Breaks Skype (And Other Applications) | securosis.com […]
[…] + rand + ”?" type="text/javascript">x3C/script>”); Mogull traced the issue to the firewall’s (application security) code signing features. Leopard signs […]
[…] traced the issue to the firewall’s (application security) code signing features. Leopard signs […]
[…] Když opomineme vypnutý firewall, je s firewallem ještě jeden signifikantní problém. Skype. Když si firewall zapnete (System Preferences – Security) a nemáte nastaveno Allow all incoming connections a používáte Skype, dojde za nějakou dobu k nepříjemné události: Skype odmítne fungovat. Na chvíli pomůže reinstalace, po nějaké další blíže nejisté době nepomůže ani ta. Securosis.com […]
[…] über eine nachlässige Standardeinstellung hinaus. Der IT-Sicherheitsberater Rich Mogull beschreibt in seinem Blog, dass eine einmal aktivierte Leopard-Firewall auf dem Mac installierte Programme beschädigen […]