Files
BinaryObjectScanner/BurnOutSharp/External/libmspack/CHM/_CHMHeader.cs
2022-05-22 23:46:29 -07:00

119 lines
3.8 KiB
C#

/* This file is part of libmspack.
* (C) 2003-2004 Stuart Caie.
*
* libmspack is free software; you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License (LGPL) version 2.1
*
* For further details, see the file COPYING.LIB distributed with libmspack
*/
using System;
namespace LibMSPackSharp.CHM
{
internal class _CHMHeader
{
#region Fields
/// <summary>
/// "ITSF"
/// </summary>
/// <remarks>0x0000</remarks>
public uint Signature { get; private set; }
/// <summary>
/// The version of the CHM file format used in this file.
/// </summary>
/// <remarks>0x0004</remarks>
public uint Version { get; private set; }
/// <summary>
/// UNKNOWN
/// </summary>
/// <remarks>0x0008</remarks>
public uint HeaderLen { get; private set; }
/// <summary>
/// UNKNOWN
/// </summary>
/// <remarks>0x000C</remarks>
public uint Unknown1 { get; private set; }
/// <summary>
/// The "timestamp" of the CHM helpfile.
/// </summary>
/// <remarks>
/// 0x0010
///
/// It is the lower 32 bits of a 64-bit value representing the number of
/// centiseconds since 1601-01-01 00:00:00 UTC, plus 42. It is not useful
/// as a timestamp, but it is useful as a semi-unique ID.
/// </remarks>
public uint Timestamp { get; private set; }
/// <summary>
/// The default Language and Country ID (LCID) of the user who ran the
/// HTMLHelp Compiler. This is not the language of the CHM file itself.
/// </summary>
/// <remarks>0x0014</remarks>
public uint LanguageID { get; private set; }
/// <summary>
/// Header GUID 1
/// </summary>
/// <remarks>0x0018</remarks>
public Guid GUID1 { get; private set; }
/// <summary>
/// Header GUID 2
/// </summary>
/// <remarks>0x0028</remarks>
public Guid GUID2 { get; private set; }
/// <summary>
/// Total size of the CHM header in bytes
/// </summary>
public const int Size = 0x0038;
#endregion
/// <summary>
/// Private constructor
/// </summary>
private _CHMHeader() { }
/// <summary>
/// Create a _CHMHeader from a byte array, if possible
/// </summary>
public static Error Create(byte[] buffer, out _CHMHeader header)
{
header = null;
if (buffer == null || buffer.Length < Size)
return Error.MSPACK_ERR_READ;
header = new _CHMHeader();
header.Signature = BitConverter.ToUInt32(buffer, 0x0000);
if (header.Signature != 0x46535449)
return Error.MSPACK_ERR_SIGNATURE;
// Expect version less than or equal to 3, but don't validate
header.Version = BitConverter.ToUInt32(buffer, 0x0004);
header.HeaderLen = BitConverter.ToUInt32(buffer, 0x0008);
header.Unknown1 = BitConverter.ToUInt32(buffer, 0x000C);
header.Timestamp = BitConverter.ToUInt32(buffer, 0x0010);
header.LanguageID = BitConverter.ToUInt32(buffer, 0x0014);
header.GUID1 = new Guid(new ReadOnlySpan<byte>(buffer, 0x0018, 0x10).ToArray());
if (header.GUID1 != Guid.Parse("7C01FD10-7BAA-11D0-9E0C-00A0-C922-E6EC"))
return Error.MSPACK_ERR_SIGNATURE;
header.GUID2 = new Guid(new ReadOnlySpan<byte>(buffer, 0x0028, 0x10).ToArray());
if (header.GUID2 != Guid.Parse("7C01FD11-7BAA-11D0-9E0C-00A0-C922-E6EC"))
return Error.MSPACK_ERR_SIGNATURE;
return Error.MSPACK_ERR_OK;
}
}
}