RtlCreateSecurityDescriptor - NtDoc

Native API online documentation, based on the System Informer (formerly Process Hacker) phnt headers
#ifndef _NTRTL_H

//
// Security Descriptors
//

/**
 * The RtlCreateSecurityDescriptor routine initializes a new absolute-format security descriptor.
 * On return, the security descriptor is initialized with no system ACL, no discretionary ACL, no owner, no primary group, and all control flags set to zero.
 * 
 * \param SecurityDescriptor Pointer to the buffer for the \ref SECURITY_DESCRIPTOR to be initialized.
 * \param Revision Specifies the revision level to assign to the security descriptor. Set this parameter to SECURITY_DESCRIPTOR_REVISION.
 * @return NTSTATUS Successful or errant status.
 * @see https://learn.microsoft.com/en-us/windows-hardware/drivers/ddi/wdm/nf-wdm-rtlcreatesecuritydescriptor
 */
NTSYSAPI
NTSTATUS
NTAPI
RtlCreateSecurityDescriptor(
    _Out_ PSECURITY_DESCRIPTOR SecurityDescriptor,
    _In_ ULONG Revision
    );

#endif

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This function is documented in Windows Driver Kit.