#ifndef _NTRTL_H

/**
 * The RtlValidRelativeSecurityDescriptor routine checks the validity of a self-relative security descriptor.
 *
 * \param SecurityDescriptorInput A pointer to the buffer that contains the security descriptor in self-relative format.
 * The buffer must begin with a SECURITY_DESCRIPTOR structure, which is followed by the rest of the security descriptor data.
 * \param SecurityDescriptorLength The size of the SecurityDescriptorInput structure.
 * \param RequiredInformation A SECURITY_INFORMATION value that specifies the information that is required to be contained in the security descriptor.
 * \return RtlValidRelativeSecurityDescriptor returns TRUE if the security descriptor is valid and includes the information that the RequiredInformation parameter specifies. Otherwise, this routine returns FALSE.
 * \see https://learn.microsoft.com/en-us/windows-hardware/drivers/ddi/wdm/nf-wdm-rtlvalidrelativesecuritydescriptor
 */
_Check_return_
NTSYSAPI
BOOLEAN
NTAPI
RtlValidRelativeSecurityDescriptor(
    _In_reads_bytes_(SecurityDescriptorLength) PSECURITY_DESCRIPTOR SecurityDescriptorInput,
    _In_ ULONG SecurityDescriptorLength,
    _In_ SECURITY_INFORMATION RequiredInformation
    );

#endif
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// wdm.h

NTSYSAPI BOOLEAN RtlValidRelativeSecurityDescriptor(
  [in] PSECURITY_DESCRIPTOR SecurityDescriptorInput,
  [in] ULONG                SecurityDescriptorLength,
  [in] SECURITY_INFORMATION RequiredInformation
);
View the official Windows Driver Kit DDI reference