fix C_WaitForSlotEvent: it should be a Library- instead of a Slot-method

add simple test for C_WaitForSlotEvent

lib/pkcs11/library.rb

@@ -86,6 +86,20 @@ def all_slots
       slots(false)
     end
 
+    alias unwrapped_C_WaitForSlotEvent C_WaitForSlotEvent
+
+    # Waits for a slot event, such as token insertion or token removal, to occur.
+    #
+    # @param [Integer] flags  determines whether or not the C_WaitForSlotEvent call blocks (i.e., waits
+    #    for a slot event to occur);
+    #    At present, the only flag defined for use in the flags argument is PKCS11::CKF_DONT_BLOCK
+    # @return [Slot, nil] the slot that the event occurred in; nil if no event occured (CKR_NO_EVENT)
+    def C_WaitForSlotEvent(flags=0)
+      slot = unwrapped_C_WaitForSlotEvent(flags)
+      slot ? Slot.new(self, slot) : nil
+    end
+    alias wait_for_slot_event C_WaitForSlotEvent
+
     # Finalize and unload the library. If not called explicit, the library is freed by the GC.
     def close
       self.C_Finalize

lib/pkcs11/slot.rb

@@ -29,22 +29,13 @@ def C_GetSlotInfo
       @pk.C_GetSlotInfo(@slot)
     end
     alias info C_GetSlotInfo
-    
+
     # Obtains information about a particular token in the system.
     # @return [PKCS11::CK_TOKEN_INFO]
     def C_GetTokenInfo
       @pk.C_GetTokenInfo(@slot)
     end
     alias token_info C_GetTokenInfo
-
-    # Waits for a slot event, such as token insertion or token removal, to
-    # occur.
-    # @param flags determines whether or not the C_WaitForSlotEvent call blocks (i.e., waits
-    #   for a slot event to occur);
-    def C_WaitForSlotEvent(flags)
-      @pk.C_WaitForSlotEvent(@slot, flags)
-    end
-    alias wait_for_event C_WaitForSlotEvent
 
     # C_GetMechanismList is used to obtain a list of mechanism types supported by a token.
     # @return [Array<PKCS11::CKM_*>]
@@ -75,7 +66,7 @@ def C_InitToken(pin, label)
       self
     end
     alias init_token C_InitToken
-    
+
     # Opens a Session between an application and a token in a particular slot.
     #
     # @param [Integer] flags  indicates the type of session. Default is read-only,
@@ -99,7 +90,7 @@ def C_OpenSession(flags=CKF_SERIAL_SESSION)
       end
     end
     alias open C_OpenSession
-    
+
     # Closes all sessions an application has with a token.
     # @return [PKCS11::Slot]
     def C_CloseAllSessions

test/test_pkcs11.rb

@@ -57,4 +57,15 @@ def test_C_Initialize_with_Hash
     pk.info
     pk.close
   end
+
+  def test_wait_for_slot_event
+    open
+    # Softokn's C_WaitForSlotEvent() currently raises PKCS11::CKR_FUNCTION_NOT_SUPPORTED.
+    # So just check, that the call goes to softokn at all.
+    begin
+      pk.wait_for_slot_event
+    rescue PKCS11::Error
+    end
+    close
+  end
 end