Platform SDK: Access Control

MakeAbsoluteSD

The MakeAbsoluteSD function creates a security descriptor in absolute format by using a security descriptor in self-relative format as a template.

BOOL MakeAbsoluteSD(
  PSECURITY_DESCRIPTOR pSelfRelativeSD, // self-relative SD
  PSECURITY_DESCRIPTOR pAbsoluteSD,     // absolute SD
  LPDWORD lpdwAbsoluteSDSize,           // absolute SD size
  PACL pDacl,                           // DACL
  LPDWORD lpdwDaclSize,                 // size of DACL
  PACL pSacl,                           // SACL
  LPDWORD lpdwSaclSize,                 // size of SACL
  PSID pOwner,                          // owner SID
  LPDWORD lpdwOwnerSize,                // size of owner SID
  PSID pPrimaryGroup,                   // primary-group SID
  LPDWORD lpdwPrimaryGroupSize          // size of group SID
);

Parameters

pSelfRelativeSD
[in] Pointer to a SECURITY_DESCRIPTOR structure in self-relative format. The function creates an absolute-format version of this security descriptor without modifying the original security descriptor.
pAbsoluteSD
[out] Pointer to a buffer that the function fills with the main body of an absolute-format security descriptor. This information is formatted as a SECURITY_DESCRIPTOR structure.
lpdwAbsoluteSDSize
[out] Pointer to a variable specifying the size of the buffer pointed to by the pAbsoluteSD parameter. If the buffer is not large enough for the security descriptor, the function fails and sets this variable to the minimum required size.
pDacl
[out] Pointer to a buffer the function fills with the discretionary access-control list (ACL) of the absolute-format security descriptor. The main body of the absolute-format security descriptor references this pointer.
lpdwDaclSize
[out] Pointer to a variable specifying the size of the buffer pointed to by the pDacl parameter. If the buffer is not large enough for the ACL, the function fails and sets this variable to the minimum required size.
pSacl
[out] Pointer to a buffer the function fills with the system ACL of the absolute-format security descriptor. The main body of the absolute-format security descriptor references this pointer.
lpdwSaclSize
[out] Pointer to a variable specifying the size of the buffer pointed to by the pSacl parameter. If the buffer is not large enough for the ACL, the function fails and sets this variable to the minimum required size.
pOwner
[out] Pointer to a buffer the function fills with the security identifier (SID) of the owner of the absolute-format security descriptor. The main body of the absolute-format security descriptor references this pointer.
lpdwOwnerSize
[out] Pointer to a variable specifying the size of the buffer pointed to by the pOwner parameter. If the buffer is not large enough for the SID, the function fails and sets this variable to the minimum required size.
pPrimaryGroup
[out] Pointer to a buffer the function fills with the SID of the absolute-format security descriptor's primary group. The main body of the absolute-format security descriptor references this pointer.
lpdwPrimaryGroupSize
[out] Pointer to a variable specifying the size of the buffer pointed to by the pPrimaryGroup parameter. If the buffer is not large enough for the SID, the function fails and sets this variable to the minimum required size.

Return Values

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

A security descriptor in absolute format contains pointers to the information it contains, rather than the information itself. A security descriptor in self-relative format contains the information in a contiguous block of memory. In a self-relative security descriptor, a SECURITY_DESCRIPTOR structure always starts the information, but the security descriptor's other components can follow the structure in any order. Instead of using memory addresses, the components of the self-relative security descriptor are identified by offsets from the beginning of the security descriptor. This format is useful when an security descriptor must be stored on a floppy disk or transmitted by means of a communications protocol.

A server that copies secured objects to various media can use the MakeAbsoluteSD function to create an absolute security descriptor from a self-relative security descriptor and the MakeSelfRelativeSD function to create a self-relative security descriptor from an absolute security descriptor.

Requirements

  Windows NT/2000: Requires Windows NT 3.1 or later.
  Header: Declared in Winbase.h; include Windows.h.
  Library: Use Advapi32.lib.

See Also

Low-Level Access-Control Overview, Low-Level Access Control Functions, ACL, MakeSelfRelativeSD, SECURITY_DESCRIPTOR