Root > Reference > Main routines > __initialize_security_cookie

Procedure __initialize_security_cookie

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Initializes a stack guard cookie.

 

Unit

ELowLevel

 

Syntax

 

Code (Delphi)

procedure __initialize_security_cookie(

out ASecurityCookie: Pointer

);

 

Parameters

ASecurityCookie [out]

Returns transparent "magic" value. This must be a local variable in the function. The local variable must be listed first.

 

Remarks

This function initializes ASecurityCookie argument with some "magic" value, which is supposed to stay unchanged during execution of current routine. If stack corruption occurs (e.g. buffer overflow damages the stack) - then this value will be changed. This change can be detected later by the __security_check_cookie function.

 

This function also protects against overwrites of return address. In other words, if function's return address will be changed/corrupted/overwritten between calls to the __security_check_cookie/__security_check_cookie functions - an error will be triggered.

 

Examples

 

Code (Delphi)

procedure DoSomething;

var

 Cookie: Pointer; // MUST be the first local variable

 // ... other local variables

begin

 __initialize_security_cookie(Cookie);

 

 // ... you normal code for DoSomething goes here

 

 __security_check_cookie(Cookie); // will throw an error if stack corruption is detected

 // or:

 // __security_check_cookie(Cookie, 'Unit1.DoSomething');

 // or:

 // __security_check_cookie(Cookie, PChar(__LOCATION__)); // uses EDebugInfo, not recommended

end;

 

See also



Send feedback... Build date: 2026-03-31
Last edited: 2026-03-31
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