Use the ICIClientSettings interface SetSSL method to allow a user to connect using SSL over FTP. Use the same method to prohibit the user from making SSL connections. Refer to User Connection Protocols for an illustration of how this and other Client Settings Interface Methods and Properties can be accessed in the Administrator interface.
Signature:
HRESULT SetSSL([in] SFTPAdvBool val);
0 = Prohibit
1 = Allow
-2 = Inherit