RegGetKeySecurity function (winreg.h)

The RegGetKeySecurity function retrieves a copy of the security descriptor protecting the specified open registry key.


LSTATUS RegGetKeySecurity(
  [in]            HKEY                 hKey,
  [in]            SECURITY_INFORMATION SecurityInformation,
  [out, optional] PSECURITY_DESCRIPTOR pSecurityDescriptor,
  [in, out]       LPDWORD              lpcbSecurityDescriptor


[in] hKey

A handle to an open key for which to retrieve the security descriptor.

[in] SecurityInformation

A SECURITY_INFORMATION value that indicates the requested security information.

[out, optional] pSecurityDescriptor

A pointer to a buffer that receives a copy of the requested security descriptor.

[in, out] lpcbSecurityDescriptor

A pointer to a variable that specifies the size, in bytes, of the buffer pointed to by the pSecurityDescriptor parameter. When the function returns, the variable contains the number of bytes written to the buffer.

Return value

If the function succeeds, the function returns ERROR_SUCCESS.

If the function fails, it returns a nonzero error code defined in WinError.h. You can use the FormatMessage function with the FORMAT_MESSAGE_FROM_SYSTEM flag to get a generic description of the error.


If the buffer specified by the pSecurityDescriptor parameter is too small, the function returns ERROR_INSUFFICIENT_BUFFER and the lpcbSecurityDescriptor parameter contains the number of bytes required for the requested security descriptor.

To read the owner, group, or discretionary access control list (DACL) from the key's security descriptor, the calling process must have been granted READ_CONTROL access when the handle was opened. To get READ_CONTROL access, the caller must be the owner of the key or the key's DACL must grant the access.

To read the system access control list (SACL) from the security descriptor, the calling process must have been granted ACCESS_SYSTEM_SECURITY access when the key was opened. The correct way to get this access is to enable the SE_SECURITY_NAME privilege in the caller's current token, open the handle for ACCESS_SYSTEM_SECURITY access, and then disable the privilege.


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

See also


Low-level Access Control

Low-level Access Control Functions