Some time ago I wrote a post on how to get a Cisco IP-Sec VPN working with client certificates on OS-X Lion. Now I upgraded to Mavericks and of course this broke my VPN connection again. Fortunately a friend already had the same problem on Mountain Lion and his fix also worked on Mavericks. To get my connections working on Mavericks I followed the instructions from my previous post: . After that I had to “allow all applications to access this item” on the certificate in Keychain.
Also see the last comment in https://discussions.apple.com/thread/4158642?start=15&tstart=0 saying to allow all access to the cert in Keychain.
I had already set the cert to be always “Trusted” but you have to expand the cert to get to the private key and always “Allow” access to it. It’s a different setting.