Last night I was trying to get a VeriSign issued SSL certificate installed on my ASA using Cisco ASDM 6.2. I installed the Intermediate CA and the CA certificates all installed. I then imported the SSL certificate into the “Configuration -> Device Management -> Manage Certificates -> Identity Certificates” but it did not seem to work. I kept getting an error “Failed to parse or verify imported certificate”. The certificate was in the .p7b form. Changing the format of the certificate to X.509 Base64 Encoded format resulted in acceptance of the certificate.
I sincerely hope that Cisco alters its error messages to accurately reflect that .p7b is not a format supported by them.

Update: This link has the information on how to install SSL certificates on ASA: