MakeAbsoluteSD function (securitybaseapi.h)

Article
10/13/2021

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

Syntax

BOOL MakeAbsoluteSD(
  [in]            PSECURITY_DESCRIPTOR pSelfRelativeSecurityDescriptor,
  [out, optional] PSECURITY_DESCRIPTOR pAbsoluteSecurityDescriptor,
  [in, out]       LPDWORD              lpdwAbsoluteSecurityDescriptorSize,
  [out, optional] PACL                 pDacl,
  [in, out]       LPDWORD              lpdwDaclSize,
  [out, optional] PACL                 pSacl,
  [in, out]       LPDWORD              lpdwSaclSize,
  [out, optional] PSID                 pOwner,
  [in, out]       LPDWORD              lpdwOwnerSize,
  [out, optional] PSID                 pPrimaryGroup,
  [in, out]       LPDWORD              lpdwPrimaryGroupSize
);

Parameters

[in] pSelfRelativeSecurityDescriptor

A 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.

[out, optional] pAbsoluteSecurityDescriptor

A 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.

[in, out] lpdwAbsoluteSecurityDescriptorSize

A pointer to a variable that specifies 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.

[out, optional] pDacl

A pointer to a buffer the function fills with the discretionary access control list (DACL) of the absolute-format security descriptor. The main body of the absolute-format security descriptor references this pointer.

[in, out] lpdwDaclSize

A pointer to a variable that specifies the size of the buffer pointed to by the pDacl parameter. If the buffer is not large enough for the access control list (ACL), the function fails and sets this variable to the minimum required size.

[out, optional] pSacl

A pointer to a buffer the function fills with the system access control list (SACL) of the absolute-format security descriptor. The main body of the absolute-format security descriptor references this pointer.

[in, out] lpdwSaclSize

A pointer to a variable that specifies 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.

[out, optional] pOwner

A 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.

[in, out] lpdwOwnerSize

A pointer to a variable that specifies 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.

[out, optional] pPrimaryGroup

A 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.

[in, out] lpdwPrimaryGroupSize

A pointer to a variable that specifies 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 value

If the function succeeds, the function returns nonzero.

If the function fails, it returns zero. To get extended error information, call GetLastError. Possible return codes include, but are not limited to, the following.

Return code/value	Description
ERROR_INSUFFICIENT_BUFFER 0x7A	One or more of the buffers is too small.

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 a 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

Requirement	Value
Minimum supported client	Windows XP [desktop apps \| UWP apps]
Minimum supported server	Windows Server 2003 [desktop apps \| UWP apps]
Target Platform	Windows
Header	securitybaseapi.h (include Windows.h)
Library	Advapi32.lib
DLL	Advapi32.dll