this week i did some research about the gnome-keyring's API and wrote some test codes.
1.diving into the manuals and APIs of gnome-keyring, especially
the section of "Gnome Keyring Certificates and Encryption Keys"
2.contact with my mentor and discuss the implementation of the GPG Key-selection, but have no reply:(
Next week plan
1.do some programming about the certificates management, i would try to implement a draft.
2.research the UI of smime, and begin to thinking about the UI.