diff --git a/src/cryptoki.hxx b/src/cryptoki.hxx
index 9f2d02e..3e52a8d 100644
--- a/src/cryptoki.hxx
+++ b/src/cryptoki.hxx
@@ -19,6 +19,7 @@
 #include <cstdlib> // malloc/free
 #include <cstring> // memset
 #include <iomanip>
+#include <memory>
 
 #include <iostream> // debug
 
@@ -217,15 +218,31 @@ namespace cryptoki {
   };
   typedef std::map<CK_ATTRIBUTE_TYPE, Attribute> AttributeMap;
   typedef std::vector<Attribute> AttributeList;
-  
+
+//   class Class {
+//     public:
+//       CK_OBJECT_CLASS class;
+//   };
+
+  //class 
 
 //   //! Map Attribute Class to type
 //   /*! @todo to be completed ... */
+//   #define CRYPTOKI_DECLARE_ATTR(ATTR_ID, TYPE) \
+//     template<> class AttributeType<ATTR_ID> { \
+//       public: typedef TYPE Type; \
+//     }
 //   template<CK_ATTRIBUTE_TYPE Attribute> class AttributeType {};
-//   template<> class AttributeType<CKA_CLASS> {
-//     public: typedef CK_OBJECT_CLASS Type;
-//     public: typedef Type Param;
-//   };
+//   CRYPTOKI_DECLARE_ATTR(CKA_CLASS, CK_OBJECT_CLASS);
+//   CRYPTOKI_DECLARE_ATTR(CKA_HW_FEATURE_TYPE, CK_HW_FEATURE);
+//   CRYPTOKI_DECLARE_ATTR(CKA_VALUE, FixString<16>);
+//   CRYPTOKI_DECLARE_ATTR(CKA_RESET_ON_INIT, CK_BBOOL);
+//   CRYPTOKI_DECLARE_ATTR(CKA_HAS_RESET, CK_BBOOL);
+// //   CRYPTOKI_DECLARE_ATTR(CKA_VALUE, ); - byte array
+// //   CRYPTOKI_DECLARE_ATTR(, );
+// //   CRYPTOKI_DECLARE_ATTR(, );
+// //   CRYPTOKI_DECLARE_ATTR(, );
+// //   CRYPTOKI_DECLARE_ATTR(, );
 //   template<> class AttributeType<CKA_KEY_TYPE> {
 //     public: typedef CK_KEY_TYPE Type;
 //     public: typedef Type Param;
@@ -238,10 +255,7 @@ namespace cryptoki {
 //     public: typedef CKA_BYTE Type;
 //     public: typedef std::string Param;
 //   };
-//   template<> class AttributeType<> {
-//     public: typedef  Type;
-//     public: typedef Type Param;
-//   };
+//   #undef CRYPTOKI_DECLARE_ATTR
 
   template<std::string::size_type SIZE>
       class FixString: public std::string {
@@ -582,15 +596,6 @@ namespace cryptoki {
           if (!std::uncaught_exception()) throw;
         }
       }
-      
-      /*! @todo Not implemented:
-          @code
-      bool finalize() {
-        //! calls @c C_Finalize
-        return check(_slot._init->_fn->C_Finalize(CK_VOID_PTR),
-                     CRYPTOKI_FN_LOG("C_Finalize"));
-      }
-
 
       /*! @name                                            C Like Error Handling
 
@@ -785,6 +790,7 @@ namespace cryptoki {
   class Session {
     private:
 
+      friend class Login;
       friend class Object;
 
       Slot& _slot;
@@ -819,6 +825,11 @@ namespace cryptoki {
 
       //! Closes actual session
       ~Session() {
+        try {
+          _login.reset();
+        } catch (...) {
+          if (!std::uncaught_exception()) throw;
+        }
         try {
           //! calls @c C_CloseSession
           check(_slot._init->_fn->C_CloseSession(_session),
@@ -1098,25 +1109,46 @@ namespace cryptoki {
       }
           @endcode */
 
-      /*! @todo Not implemented:
-          @code
-      bool login() {
-        //! calls @c C_Login
-        return check(_slot._init->_fn->C_Login(_session, CK_USER_TYPE, CK_CHAR_PTR, CK_ULONG),
-                     CRYPTOKI_FN_LOG("C_Login"));
-      }
-          @endcode */
+      class Login {
+          
+        public:
+          
+          Login(Session& session,
+                const std::string& pin,
+                CK_USER_TYPE userType=CKU_USER): _session(session) {
+            //! calls @c C_Login
+            _session.check(_session._slot._init->_fn->C_Login
+                           (_session._session, userType,
+                            (CK_CHAR*)pin.c_str(),
+                            pin.size()),
+                           CRYPTOKI_FN_LOG("C_Login"));
+          }
 
-      /*! @todo Not implemented:
-          @code
-      bool logout() {
-        //! calls @c C_Logout
-        return check(_slot._init->_fn->C_Logout(_session),
-                     CRYPTOKI_FN_LOG("C_Logout"));
-      }
-          @endcode */
+          ~Login() {
+            try {
+              //! calls @c C_Logout
+              _session.check(_session._slot._init->_fn->C_Logout
+                             (_session._session),
+                             CRYPTOKI_FN_LOG("C_Logout"));
+            } catch (...) {
+              if (!std::uncaught_exception()) throw;
+            }
+          }
+          
+        private:
 
+          Session& _session;
+          
+      };
 
+      void login(const std::string& pin, CK_USER_TYPE userType=CKU_USER) {
+        _login = std::auto_ptr<Login>(new Login(*this, pin, userType));
+      }
+      void logout() {
+        _login.reset();
+      }
+      std::auto_ptr<Login> _login;
+      
       /*! @todo Not implemented:
           @code
       bool seedrandom() {