Protected items serve for storing data (dump, string, number) as well as regular memory fields but at the same time they are protected by hardware read/write locks.
The status of a protected item can be programmed and further controlled from within the application. Besides, the protected items technology provides for accessing the item contents and updating the item without rewriting the whole dongle memory.
Several Guardant API functions serve for operating with protected items from within the application: GrdPI_Activate, GrdPI_Deactivate, GrdPI _Update, and GrdPI_Read.
The dialog of creating a protected item is made in the form of a wizard containing several pages:
- Add protected item (new field)
- Protected item properties
- Protected item contents
Click [Next] to move to the next page after completing the current dialog.
Creating
For the modern dongles, the size of protected item is arbitrary; for the old models – 1 – 255+ service fields.
Execute menu command Edit | Add new field to create a protected item.
Select Protected item field type in Add new field dialog box that will appear and assign its name and size:
Properties
Protected item properties window contains flags controlling the services of protected items:
The services allow for:
- Setting the status of protected item (active/inactive) and further control of the status from within the application or through remote update
- Accessing item contents and updating it without affecting (rewriting) the rest of the memory (compare with hardware locks ideology).
Size of protected item data:
- The statistical information on the size of protected item appears in the lower part of Protected item properties dialog box (indicating the selected number representation).
- The size of protected item descriptor is the total of sizes of its components: determinant and set of services.
Editing
Protected item contents dialog box is a hexadecimal editor for entering and modifying the protected item data:
The data is entered directly into the editor window in hexadecimal form or as a character set.
Protected item contents dialog box control elements:
| Interface element | Description of purpose |
|---|---|
| Hexadecimal editor window | Allow to enter protected item value |
| [Load] button | Load dump from *.dmp file |
| [Save] button | Save dump into *.dmp file |
| OEM flag | Select Windows/DOS encoding. Windows (ANSI) encoding is used by default – OEM option is off. |
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After editing the protected item contents and clicking [Finish] button the dialog box will close and a new protected item will appear in the list of mask fields. Whereas GrdUtil.exe will automatically assign an index number* to the algorithm and correct the boundary of hardware locks considering the added protected item.
Now all you have to do is write the mask into the dongle and the newly created protected item will be available for use.