/// <summary>
/// Validate the header and CRC-32 of this structure.
/// </summary>
/// <returns>True if the structure is valid.</returns>
/// <remarks></remarks>
public bool Validate()
{
bool ValidateRet = default;
var mm = new MemPtr();
mm.FromStruct(this);
mm.UIntAt(4L) = 0U;
// validate the crc and the signature moniker
ValidateRet = HeaderCRC32 == mm.CalculateCrc32() && Signature == 0x5452415020494645;
mm.Free();
return(ValidateRet);
}
/// <summary>
/// Retrieve the partition table of a GPT-layout disk, manually.
/// Must be Administrator.
/// </summary>
/// <param name="inf">DiskDeviceInfo object to the physical disk to read.</param>
/// <param name="gptInfo">Receives the drive layout information.</param>
/// <returns>True if successful.</returns>
/// <remarks></remarks>
public static bool ReadRawGptDisk(string devicePath, ref RAW_GPT_DISK gptInfo)
{
// Demand Administrator for accessing a raw disk.
AppDomain.CurrentDomain.SetPrincipalPolicy(PrincipalPolicy.WindowsPrincipal);
// Dim principalPerm As New PrincipalPermission(Nothing, "Administrators")
// principalPerm.Demand()
var hfile = IO.CreateFile(devicePath, IO.GENERIC_READ | IO.GENERIC_WRITE, IO.FILE_SHARE_READ | IO.FILE_SHARE_WRITE, IntPtr.Zero, IO.OPEN_EXISTING, IO.FILE_FLAG_NO_BUFFERING | IO.FILE_FLAG_RANDOM_ACCESS, IntPtr.Zero);
if (hfile == DevProp.INVALID_HANDLE_VALUE)
{
return(false);
}
DISK_GEOMETRY_EX geo = default;
// get the disk geometry to retrieve the sector (LBA) size.
if (!DiskGeometry(hfile, ref geo))
{
User32.CloseHandle(hfile);
return(false);
}
// sector size (usually 512 bytes)
uint bps = geo.Geometry.BytesPerSector;
uint br = 0U;
long lp = 0L;
long lp2 = 0L;
var mm = new MemPtr(bps * 2L);
IO.SetFilePointerEx(hfile, 0L, ref lp, IO.FilePointerMoveMethod.Begin);
IO.ReadFile(hfile, mm.Handle, bps * 2, ref br, IntPtr.Zero);
var mbr = new RAW_MBR();
var gpt = new RAW_GPT_HEADER();
RAW_GPT_PARTITION[] gpp = null;
// read the master boot record.
mbr = mm.ToStructAt <RAW_MBR>(446L);
// read the GPT structure header.
gpt = mm.ToStructAt <RAW_GPT_HEADER>(bps);
// check the partition header CRC.
if (gpt.IsValid)
{
long lr = br;
// seek to the LBA of the partition information.
IO.SetFilePointerEx(hfile, (uint)(bps * gpt.PartitionEntryLBA), ref lr, IO.FilePointerMoveMethod.Begin);
br = (uint)lr;
// calculate the size of the partition table buffer.
lp = gpt.NumberOfPartitions * gpt.PartitionEntryLength;
// byte align to the sector size.
if (lp % bps != 0L)
{
lp += bps - lp % bps;
}
// bump up the memory pointer.
mm.ReAlloc(lp);
mm.ZeroMemory();
// read the partition information into the pointer.
IO.ReadFile(hfile, mm.Handle, (uint)lp, ref br, IntPtr.Zero);
// check the partition table CRC.
if (mm.CalculateCrc32() == gpt.PartitionArrayCRC32)
{
// disk is valid.
lp = (uint)Marshal.SizeOf <RAW_GPT_PARTITION>();
br = 0U;
int i;
int c = (int)gpt.NumberOfPartitions;
gpp = new RAW_GPT_PARTITION[c + 1];
// populate the drive information.
for (i = 0; i < c; i++)
{
gpp[i] = mm.ToStructAt <RAW_GPT_PARTITION>(lp2);
// break on empty GUID, we are past the last partition.
if (gpp[i].PartitionTypeGuid == Guid.Empty)
{
break;
}
lp2 += lp;
}
// trim off excess records from the array.
if (i < c)
{
if (i == 0)
{
gpp = Array.Empty <RAW_GPT_PARTITION>();
}
else
{
Array.Resize(ref gpp, i);
}
}
}
}
// free the resources.
mm.Free();
User32.CloseHandle(hfile);
// if gpp is nothing then some error occurred somewhere and we did not succeed.
if (gpp is null)
{
return(false);
}
// create a new RAW_GPT_DISK structure.
gptInfo = new RAW_GPT_DISK();
gptInfo.Header = gpt;
gptInfo.Partitions = gpp;
// we have succeeded.
return(true);
}