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IStackWalk.Assert Method

Asserts that the calling code can access the resource identified by the current permission object, even if callers higher in the stack have not been granted permission to access the resource.

[Visual Basic]
Sub Assert()
void Assert();
void Assert();
function Assert();


Exception Type Condition
SecurityException The calling code does not have SecurityPermissionFlag.Assertion.


Calling Assert stops the permission check on callers higher in the call stack. Therefore, even if these callers do not have the requisite permissions, they can still access resources. An assertion is effective only if the code that calls Assert passes the security check for the permission that it is asserting.

A call to Assert is effective until the calling code returns to its caller or until a subsequent call to Assert renders the previous assertion ineffective. Also, RevertAssert or RevertAll removes a pending Assert.

Assert is ignored for a permission not granted because a demand for that permission will not succeed. However, if code lower on the call stack calls Demand for that permission, a SecurityException is thrown when the stack walk reaches the code that tried to call Assert. This happens because the code that called Assert has not been granted the permission, even though it tried to Assert it.

CAUTION   Because calling Assert removes the requirement that all code in the call chain must be granted permission to access the specified resource, it can open up security vulnerabilities if used incorrectly or inappropriately. Therefore, it should be used with great caution.


Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

See Also

IStackWalk Interface | IStackWalk Members | System.Security Namespace | Assert | Overriding Security Checks