/// <summary>
/// Query a variable buffer from the object.
/// </summary>
/// <typeparam name="T">The type of structure to return.</typeparam>
/// <param name="info_class">The information class to query.</param>
/// <param name="default_value">A default value for the query.</param>
/// <param name="throw_on_error">True to throw on error.</param>
/// <returns>The result of the query.</returns>
/// <exception cref="NtException">Thrown on error.</exception>
public virtual NtResult <SafeStructureInOutBuffer <T> > QueryBuffer <T>(Q info_class, T default_value, bool throw_on_error) where T : new()
{
NtStatus status;
int return_length;
// First try base size before trying to reallocate.
using (var buffer = default_value.ToBuffer())
{
status = QueryInformation(info_class, buffer, out return_length);
if (status.IsSuccess())
{
return(status.CreateResult(false, () => buffer.Detach()));
}
}
if (!IsInvalidBufferStatus(status))
{
return(status.CreateResultFromError <SafeStructureInOutBuffer <T> >(throw_on_error));
}
// If the function returned a length then trust it.
if (return_length > 0 && GetTrustReturnLength(info_class))
{
using (var buffer = new SafeStructureInOutBuffer <T>(default_value, return_length, false))
{
return(QueryInformation(info_class, buffer, out return_length).CreateResult(throw_on_error, () => buffer.Detach()));
}
}
// Function length can't be trusted, we'll need to brute force it.
return_length = GetSmallestPower2(Marshal.SizeOf(typeof(T)));
int max_length = GetMaximumBruteForceLength(info_class);
while (return_length < max_length)
{
using (var buffer = new SafeStructureInOutBuffer <T>(default_value, return_length, false))
{
status = QueryInformation(info_class, buffer, out int dummy_length);
if (status.IsSuccess())
{
return(status.CreateResult(throw_on_error, () => buffer.Detach()));
}
else if (!IsInvalidBufferStatus(status))
{
return(status.CreateResultFromError <SafeStructureInOutBuffer <T> >(throw_on_error));
}
return_length *= 2;
}
}
return(NtStatus.STATUS_BUFFER_TOO_SMALL.CreateResultFromError <SafeStructureInOutBuffer <T> >(throw_on_error));
}
private NtResult <SafeHGlobalBuffer> CreateAbsoluteSecurityDescriptor(bool throw_on_error)
{
byte[] dacl = Dacl?.ToByteArray();
byte[] sacl = Sacl?.ToByteArray();
byte[] owner = Owner?.Sid.ToArray();
byte[] group = Group?.Sid.ToArray();
int total_size = GetLength(dacl) + GetLength(sacl) + GetLength(owner) + GetLength(group);
using (var sd_buffer = new SafeStructureInOutBuffer <SecurityDescriptorStructure>(total_size, true))
{
NtStatus status = NtRtl.RtlCreateSecurityDescriptor(sd_buffer, Revision);
if (!status.IsSuccess())
{
return(status.CreateResultFromError <SafeHGlobalBuffer>(throw_on_error));
}
SecurityDescriptorControl control = Control & SecurityDescriptorControl.ValidControlSetMask;
status = NtRtl.RtlSetControlSecurityDescriptor(sd_buffer, control, control);
if (!status.IsSuccess())
{
return(status.CreateResultFromError <SafeHGlobalBuffer>(throw_on_error));
}
int current_ofs = 0;
if (Dacl != null)
{
IntPtr ptr = UpdateBuffer(sd_buffer, Dacl.NullAcl ? null : dacl, ref current_ofs);
status = NtRtl.RtlSetDaclSecurityDescriptor(sd_buffer, true, ptr, Dacl.Defaulted);
if (!status.IsSuccess())
{
return(status.CreateResultFromError <SafeHGlobalBuffer>(throw_on_error));
}
}
if (Sacl != null)
{
IntPtr ptr = UpdateBuffer(sd_buffer, Sacl.NullAcl ? null : sacl, ref current_ofs);
status = NtRtl.RtlSetSaclSecurityDescriptor(sd_buffer, true, ptr, Sacl.Defaulted);
if (!status.IsSuccess())
{
return(status.CreateResultFromError <SafeHGlobalBuffer>(throw_on_error));
}
}
if (Owner != null)
{
IntPtr ptr = UpdateBuffer(sd_buffer, owner, ref current_ofs);
status = NtRtl.RtlSetOwnerSecurityDescriptor(sd_buffer, ptr, Owner.Defaulted);
if (!status.IsSuccess())
{
return(status.CreateResultFromError <SafeHGlobalBuffer>(throw_on_error));
}
}
if (Group != null)
{
IntPtr ptr = UpdateBuffer(sd_buffer, group, ref current_ofs);
status = NtRtl.RtlSetGroupSecurityDescriptor(sd_buffer, ptr, Group.Defaulted);
if (!status.IsSuccess())
{
return(status.CreateResultFromError <SafeHGlobalBuffer>(throw_on_error));
}
}
return(status.CreateResult <SafeHGlobalBuffer>(throw_on_error, () => sd_buffer.Detach()));
}
}