[Tokend-Dev] How to clear Safari SSL cache

Hi, everyone! I found after I plug out my ccid reader and after my tokend process exits normally, I can still visit the SSL web page. How can I clear the SSL login cache after plug out the reader or smardcard? I found there's a certificate identity preference item left in the Keychain, how can I delete the certificate identity preference item using Keychain API or some shell scripts. Thank you!