private static bool ExecuteCommandBinding(object sender, ExecutedRoutedEventArgs e, CommandBinding commandBinding)
{
// Asserting a permission in the case that the command was user initiated
// and the command is a secure command. We can do this safely because at
// the time the binding was setup, we demanded the permission.
ISecureCommand secureCommand = e.Command as ISecureCommand;
bool elevate = e.UserInitiated && (secureCommand != null) && (secureCommand.UserInitiatedPermission != null);
if (elevate)
{
secureCommand.UserInitiatedPermission.Assert(); //BlessedAssert
}
try
{
commandBinding.OnExecuted(sender, e);
}
finally
{
if (elevate)
{
CodeAccessPermission.RevertAssert();
}
}
return(e.Handled);
}
void CheckSecureCommand(ICommand command, InputGesture gesture)
{
// In v3.5, only ApplicationCommands.Paste was treated as ISecureCommand,
// causing the below demand to fail if a binding for it was created. As
// there's no provable security vulnerability and for backwards compat
// reasons, we special-case Cut and Copy not to be subject to this check
// even though they have been promoted to ISecureCommand in v4.0.
ISecureCommand secure = command as ISecureCommand;
if (secure != null &&
command != ApplicationCommands.Cut &&
command != ApplicationCommands.Copy)
{
secure.UserInitiatedPermission.Demand();
}
}
void CheckSecureCommand(ICommand command, InputGesture gesture)
{
// In v3.5, only ApplicationCommands.Paste was treated as ISecureCommand,
// causing the below demand to fail if a binding for it was created. As
// there's no provable security vulnerability and for backwards compat
// reasons, we special-case Cut and Copy not to be subject to this check
// even though they have been promoted to ISecureCommand in v4.0.
//
// See Dev10 bug 815844 on reevaluating the threat model around protection
// of key bindings. The following demand may be unnecessary or misguided.
ISecureCommand secure = command as ISecureCommand;
if (secure != null &&
command != ApplicationCommands.Cut &&
command != ApplicationCommands.Copy)
{
secure.UserInitiatedPermission.Demand();
}
}