This sample program illustrates how the AOCE Digital Signature
Manager may be used to sign and verify the contents of entire
files or individual objects. It also shows how to integrate Digital
Signatures into the Think Class Library organizational structure.
Note, however, that this sample does not demonstrate the proper human interface for signed objects. Also, you should carefully consider whether your application needs to sign its documents.
The sample was built by extending the Think Class Library
“TinyEdit” example. The DemoApp and DemoEditDoc classes are subclasses of CEditApp and CEditDoc respectively, while
DemoMain.c replaces TinyEdit.c and the other classes are new.
This sample requires Think C 6.0 and Think Class Library 1.1.3.
It does not compile under Think C 5.0.4. Full directions for
building the demo are in the file "!Building This Demo.note"
The sample adds two menu options to the File menu:
• “Open and Verify File…” opens a signed file.
It verifies the digital signature and opens the
file read-only. (Signing a file sets the "locked"
flag: if you try opening it using the Open menu
option, you'll get an error message.
• “Save, Close, and Sign File…” saves the current
contents of the window as a new file, then signs
that file using your registered Digital Signature.
The sample also adds a new menu, Signed Object Demo that
illustrates how your applications can sign individual
objects, such as the state of checkboxes and radio
buttons. The Signed Object Demo does not, however,
illustrate the proper human interface for signed objects.
