Is PKCS#7 format supported by Mac OS X 10.6 to 10.7?

Hi,

Couple of questions on Mac OS X 10.6 to 10.7.

1) Can a Mac OS X 10.6 to 10.7 version supports PKCS#7 format for SSL certificate installation?

2) If PKCS#7 format is supported, is the file extension .p7b file?

Thanks!

J