Inno Header v6 reading almost works

IInnoHeader.cs

@@ -0,0 +1,84 @@
+using System;
+
+namespace InnoPatcher;
+
+internal interface IInnoHeader : IInnoSerializable
+{
+  string? AppName { get; set; }
+  string? AppVerName { get; set; }
+  string? AppId { get; set; }
+  string? AppCopyright { get; set; }
+  string? AppPublisher { get; set; }
+  string? AppPublisherURL { get; set; }
+  string? AppSupportPhone { get; set; }
+  string? AppSupportURL { get; set; }
+  string? AppUpdatesURL { get; set; }
+  string? AppVersion { get; set; }
+  string? DefaultDirName { get; set; }
+  string? DefaultGroupName { get; set; }
+  string? BaseFilename { get; set; }
+  string? UninstallFilesDir { get; set; }
+  string? UninstallDisplayName { get; set; }
+  string? UninstallDisplayIcon { get; set; }
+  string? AppMutex { get; set; }
+  string? DefaultUserInfoName { get; set; }
+  string? DefaultUserInfoOrg { get; set; }
+  string? DefaultUserInfoSerial { get; set; }
+  string? AppReadmeFile { get; set; }
+  string? AppContact { get; set; }
+  string? AppComments { get; set; }
+  string? AppModifyPath { get; set; }
+  string? CreateUninstallRegKey { get; set; }
+  string? Uninstallable { get; set; }
+  string? CloseApplicationsFilter { get; set; }
+  string? SetupMutex { get; set; }
+  string? ChangesEnvironment { get; set; }
+  string? ChangesAssociations { get; set; }
+
+  ReadOnlySpan<byte> LicenseText { get; set; }
+  ReadOnlySpan<byte> InfoBeforeText { get; set; }
+  ReadOnlySpan<byte> InfoAfterText { get; set; }
+  ReadOnlySpan<byte> CompiledCodeText { get; set; }
+
+  int NumLanguageEntries { get; set; }
+  int NumCustomMessageEntries { get; set; }
+  int NumPermissionEntries { get; set; }
+  int NumTypeEntries { get; set; }
+  int NumComponentEntries { get; set; }
+  int NumTaskEntries { get; set; }
+  int NumDirEntries { get; set; }
+  int NumFileEntries { get; set; }
+  int NumFileLocationEntries { get; set; }
+  int NumIconEntries { get; set; }
+  int NumIniEntries { get; set; }
+  int NumRegistryEntries { get; set; }
+  int NumInstallDeleteEntries { get; set; }
+  int NumUninstallDeleteEntries { get; set; }
+  int NumRunEntries { get; set; }
+  int NumUninstallRunEntries { get; set; }
+  InnoVersionData MinVersion { get; set; }
+  InnoVersionData OnlyBelowVersion { get; set; }
+  int BackColor { get; set; }
+  int BackColor2 { get; set; }
+  InnoWizardStyle WizardStyle { get; set; }
+  int WizardSizePercentX { get; set; }
+  int WizardSizePercentY { get; set; }
+  InnoAlphaFormat WizardImageAlphaFormat { get; set; }
+  InnoSha1Digest PasswordHash { get; set; }
+  InnoSalt PasswordSalt { get; set; }
+  long ExtraDiskSpaceRequired { get; set; }
+  int SlicesPerDisk { get; set; }
+  InnoLogMode UninstallLogMode { get; set; }
+  InnoAutoNoYes DirExistsWarning { get; set; }
+  InnoPrivilegesRequired PrivilegesRequired { get; set; }
+  InnoPrivilegesRequiredOverride PrivilegesRequiredOverridesAllowed { get; set; }
+  InnoYesNoAuto ShowLanguageDialog { get; set; }
+  InnoLanguageDetectionMethod LanguageDetectionMethod { get; set; }
+  InnoCompressMethod CompressMethod { get; set; }
+  InnoProcessorArchitecture ArchitecturesAllowed { get; set; }
+  InnoProcessorArchitecture ArchitecturesInstallIn64BitMode { get; set; }
+  InnoDisablePage DisableDirPage { get; set; }
+  InnoDisablePage DisableProgramGroupPage { get; set; }
+  long UninstallDisplaySize { get; set; }
+  InnoHeaderOption Options { get; set; }
+}

IInnoSerializable.cs

@@ -0,0 +1,21 @@
+using System;
+
+namespace InnoPatcher;
+
+/// <summary>
+/// Serializable Inno structure.
+/// </summary>
+internal interface IInnoSerializable {
+  int StringCount { get; }
+  int ByteArrayCount { get; }
+  int PrimitiveSize { get; }
+
+  string? GetString(int idx);
+  void SetString(int idx, string? value);
+
+  ReadOnlySpan<byte> GetByteArray(int idx);
+  void SetByteArray(int idx, ReadOnlySpan<byte> value);
+
+  ReadOnlySpan<byte> GetPrimitive();
+  void SetPrimitive(ReadOnlySpan<byte> raw);
+}

InnoAlphaFormat.cs

@@ -0,0 +1,6 @@
+namespace InnoPatcher;
+
+internal  enum InnoAlphaFormat {
+  // Must be same as Graphics.TAlphaFormat
+  Ignored, Defined, Premultiplied
+}

InnoAutoNoYes.cs

@@ -0,0 +1,5 @@
+namespace InnoPatcher;
+
+internal enum InnoAutoNoYes {
+  Auto, No, Yes
+}

InnoCompressMethod.cs

@@ -0,0 +1,13 @@
+namespace InnoPatcher;
+
+internal enum InnoCompressMethod {
+  Stored, Zip, Bzip, LZMA, LZMA2
+}
+
+internal enum InnoCompressMethod4205 {
+  Stored, Bzip, LZMA
+}
+
+internal enum InnoCompressMethodPre4205 {
+  Zip, Bzip, LZMA
+}

InnoDisablePage.cs

@@ -0,0 +1,5 @@
+namespace InnoPatcher;
+
+internal enum InnoDisablePage {
+  Auto, No, Yes
+}

InnoHeaderOption.cs

@@ -0,0 +1,30 @@
+namespace InnoPatcher;
+
+[Flags]
+public enum InnoHeaderOption {
+  DisableStartupPrompt = 0x000001,
+  Uninstallable = 0x000002,
+  CreateAppDir = 0x000004,
+  DisableDirPage = 0x000008,
+  DisableProgramGroupPage = 0x000010,
+  AllowNoIcons = 0x000020,
+  AlwaysRestart = 0x000040,
+  AlwaysUsePersonalGroup = 0x000080,
+  WindowVisible = 0x000100,
+  WindowShowCaption = 0x000200,
+  WindowResizable = 0x000400,
+  WindowStartMaximized = 0x000800,
+  EnableDirDoesntExistWarning = 0x001000,
+  DisableAppendDir = 0x002000,
+  Password = 0x004000,
+  AllowRootDirectory = 0x008000,
+  DisableFinishedPage = 0x010000,
+  AdminPrivilegesRequired = 0x020000,
+  AlwaysCreateUninstallIcon = 0x040000,
+  ChangesAssociations = 0x080000,
+  CreateUninstallRegKey = 0x100000,
+  UsePreviousAppDir = 0x200000,
+  BackColorHorizontal = 0x400000,
+  UsePreviousGroup = 0x800000,
+  UpdateUninstallLogAppName = 0x1000000,
+}

InnoHeaderV6.cs

@@ -0,0 +1,236 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace InnoPatcher;
+
+sealed class InnoHeaderV6 : IInnoHeader, IInnoSerializable
+{
+  public string? AppName { get; set; }
+  public string? AppVerName { get; set; }
+  public string? AppId { get; set; }
+  public string? AppCopyright { get; set; }
+  public string? AppPublisher { get; set; }
+  public string? AppPublisherURL { get; set; }
+  public string? AppSupportPhone { get; set; }
+  public string? AppSupportURL { get; set; }
+  public string? AppUpdatesURL { get; set; }
+  public string? AppVersion { get; set; }
+  public string? DefaultDirName { get; set; }
+  public string? DefaultGroupName { get; set; }
+  public string? BaseFilename { get; set; }
+  public string? UninstallFilesDir { get; set; }
+  public string? UninstallDisplayName { get; set; }
+  public string? UninstallDisplayIcon { get; set; }
+  public string? AppMutex { get; set; }
+  public string? DefaultUserInfoName { get; set; }
+  public string? DefaultUserInfoOrg { get; set; }
+  public string? DefaultUserInfoSerial { get; set; }
+  public string? AppReadmeFile { get; set; }
+  public string? AppContact { get; set; }
+  public string? AppComments { get; set; }
+  public string? AppModifyPath { get; set; }
+  public string? CreateUninstallRegKey { get; set; }
+  public string? Uninstallable { get; set; }
+  public string? CloseApplicationsFilter { get; set; }
+  public string? SetupMutex { get; set; }
+  public string? ChangesEnvironment { get; set; }
+  public string? ChangesAssociations { get; set; }
+
+  private byte[]? _licenseText;
+  public ReadOnlySpan<byte> LicenseText { get => _licenseText; set { _licenseText = value.ToArray(); } }
+  private byte[]? _infoBeforeText;
+  public ReadOnlySpan<byte> InfoBeforeText { get => _infoBeforeText; set { _infoBeforeText = value.ToArray(); } }
+  private byte[]? _infoAfterText;
+  public ReadOnlySpan<byte> InfoAfterText { get => _infoAfterText; set { _infoAfterText = value.ToArray(); } }
+  private byte[]? _compiledCodeText;
+  public ReadOnlySpan<byte> CompiledCodeText { get => _compiledCodeText; set { _compiledCodeText = value.ToArray(); } }
+
+  private Primitives _primitives;
+
+  public int NumLanguageEntries { get => _primitives.NumLanguageEntries; set => _primitives.NumLanguageEntries = value; }
+  public int NumCustomMessageEntries { get => _primitives.NumCustomMessageEntries; set => _primitives.NumCustomMessageEntries = value; }
+  public int NumPermissionEntries { get => _primitives.NumPermissionEntries; set => _primitives.NumPermissionEntries = value; }
+  public int NumTypeEntries { get => _primitives.NumTypeEntries; set => _primitives.NumTypeEntries = value; }
+  public int NumComponentEntries { get => _primitives.NumComponentEntries; set => _primitives.NumComponentEntries = value; }
+  public int NumTaskEntries { get => _primitives.NumTaskEntries; set => _primitives.NumTaskEntries = value; }
+  public int NumDirEntries { get => _primitives.NumDirEntries; set => _primitives.NumDirEntries = value; }
+  public int NumFileEntries { get => _primitives.NumFileEntries; set => _primitives.NumFileEntries = value; }
+  public int NumFileLocationEntries { get => _primitives.NumFileLocationEntries; set => _primitives.NumFileLocationEntries = value; }
+  public int NumIconEntries { get => _primitives.NumIconEntries; set => _primitives.NumIconEntries = value; }
+  public int NumIniEntries { get => _primitives.NumIniEntries; set => _primitives.NumIniEntries = value; }
+  public int NumRegistryEntries { get => _primitives.NumRegistryEntries; set => _primitives.NumRegistryEntries = value; }
+  public int NumInstallDeleteEntries { get => _primitives.NumInstallDeleteEntries; set => _primitives.NumInstallDeleteEntries = value; }
+  public int NumUninstallDeleteEntries { get => _primitives.NumUninstallDeleteEntries; set => _primitives.NumUninstallDeleteEntries = value; }
+  public int NumRunEntries { get => _primitives.NumRunEntries; set => _primitives.NumRunEntries = value; }
+  public int NumUninstallRunEntries { get => _primitives.NumUninstallRunEntries; set => _primitives.NumUninstallRunEntries = value; }
+  public InnoVersionData MinVersion { get => _primitives.MinVersion; set => _primitives.MinVersion = value; }
+  public InnoVersionData OnlyBelowVersion { get => _primitives.OnlyBelowVersion; set => _primitives.OnlyBelowVersion = value; }
+  public int BackColor { get => _primitives.BackColor; set => _primitives.BackColor = value; }
+  public int BackColor2 { get => _primitives.BackColor2; set => _primitives.BackColor2 = value; }
+  public InnoWizardStyle WizardStyle { get => _primitives.WizardStyle; set => _primitives.WizardStyle = value; }
+  public int WizardSizePercentX { get => _primitives.WizardSizePercentX; set => _primitives.WizardSizePercentX = value; }
+  public int WizardSizePercentY { get => _primitives.WizardSizePercentY; set => _primitives.WizardSizePercentY = value; }
+  public InnoAlphaFormat WizardImageAlphaFormat { get => _primitives.WizardImageAlphaFormat; set => _primitives.WizardImageAlphaFormat = value; }
+  public InnoSha1Digest PasswordHash { get => _primitives.PasswordHash; set => _primitives.PasswordHash = value; }
+  public InnoSalt PasswordSalt { get => _primitives.PasswordSalt; set => _primitives.PasswordSalt = value; }
+  public long ExtraDiskSpaceRequired { get => _primitives.ExtraDiskSpaceRequired; set => _primitives.ExtraDiskSpaceRequired = value; }
+  public int SlicesPerDisk { get => _primitives.SlicesPerDisk; set => _primitives.SlicesPerDisk = value; }
+  public InnoLogMode UninstallLogMode { get => _primitives.UninstallLogMode; set => _primitives.UninstallLogMode = value; }
+  public InnoAutoNoYes DirExistsWarning { get => _primitives.DirExistsWarning; set => _primitives.DirExistsWarning = value; }
+  public InnoPrivilegesRequired PrivilegesRequired { get => _primitives.PrivilegesRequired; set => _primitives.PrivilegesRequired = value; }
+  public InnoPrivilegesRequiredOverride PrivilegesRequiredOverridesAllowed { get => _primitives.PrivilegesRequiredOverridesAllowed; set => _primitives.PrivilegesRequiredOverridesAllowed = value; }
+  public InnoYesNoAuto ShowLanguageDialog { get => _primitives.ShowLanguageDialog; set => _primitives.ShowLanguageDialog = value; }
+  public InnoLanguageDetectionMethod LanguageDetectionMethod { get => _primitives.LanguageDetectionMethod; set => _primitives.LanguageDetectionMethod = value; }
+  public InnoCompressMethod CompressMethod { get => _primitives.CompressMethod; set => _primitives.CompressMethod = value; }
+  public InnoProcessorArchitecture ArchitecturesAllowed { get => _primitives.ArchitecturesAllowed; set => _primitives.ArchitecturesAllowed = value; }
+  public InnoProcessorArchitecture ArchitecturesInstallIn64BitMode { get => _primitives.ArchitecturesInstallIn64BitMode; set => _primitives.ArchitecturesInstallIn64BitMode = value; }
+  public InnoDisablePage DisableDirPage { get => _primitives.DisableDirPage; set => _primitives.DisableDirPage = value; }
+  public InnoDisablePage DisableProgramGroupPage { get => _primitives.DisableProgramGroupPage; set => _primitives.DisableProgramGroupPage = value; }
+  public long UninstallDisplaySize { get => _primitives.UninstallDisplaySize; set => _primitives.UninstallDisplaySize = value; }
+  public InnoHeaderOption Options { get => _primitives.Options; set => _primitives.Options = value; }
+
+  #region IInnoSerializable Members
+
+  public int StringCount => 30;
+  public int ByteArrayCount => 4;
+  public int PrimitiveSize => Marshal.SizeOf<Primitives>();
+
+  public string? GetString(int idx)
+  {
+    switch (idx)
+    {
+      case 0: return AppName;
+      case 1: return AppVerName;
+      case 2: return AppId;
+      case 3: return AppCopyright;
+      case 4: return AppPublisher;
+      case 5: return AppPublisherURL;
+      case 6: return AppSupportPhone;
+      case 7: return AppSupportURL;
+      case 8: return AppUpdatesURL;
+      case 9: return AppVersion;
+      case 10: return DefaultDirName;
+      case 11: return DefaultGroupName;
+      case 12: return BaseFilename;
+      case 13: return UninstallFilesDir;
+      case 14: return UninstallDisplayName;
+      case 15: return UninstallDisplayIcon;
+      case 16: return AppMutex;
+      case 17: return DefaultUserInfoName;
+      case 18: return DefaultUserInfoOrg;
+      case 19: return DefaultUserInfoSerial;
+      case 20: return AppReadmeFile;
+      case 21: return AppContact;
+      case 22: return AppComments;
+      case 23: return AppModifyPath;
+      case 24: return CreateUninstallRegKey;
+      case 25: return Uninstallable;
+      case 26: return CloseApplicationsFilter;
+      case 27: return SetupMutex;
+      case 28: return ChangesEnvironment;
+      case 29: return ChangesAssociations;
+      default: throw new ArgumentOutOfRangeException();
+    }
+  }
+
+  public void SetString(int idx, string? value)
+  {
+    switch (idx)
+    {
+      case 0: AppName = value; break;
+      case 1: AppVerName = value; break;
+      case 2: AppId = value; break;
+      case 3: AppCopyright = value; break;
+      case 4: AppPublisher = value; break;
+      case 5: AppPublisherURL = value; break;
+      case 6: AppSupportPhone = value; break;
+      case 7: AppSupportURL = value; break;
+      case 8: AppUpdatesURL = value; break;
+      case 9: AppVersion = value; break;
+      case 10: DefaultDirName = value; break;
+      case 11: DefaultGroupName = value; break;
+      case 12: BaseFilename = value; break;
+      case 13: UninstallFilesDir = value; break;
+      case 14: UninstallDisplayName = value; break;
+      case 15: UninstallDisplayIcon = value; break;
+      case 16: AppMutex = value; break;
+      case 17: DefaultUserInfoName = value; break;
+      case 18: DefaultUserInfoOrg = value; break;
+      case 19: DefaultUserInfoSerial = value; break;
+      case 20: AppReadmeFile = value; break;
+      case 21: AppContact = value; break;
+      case 22: AppComments = value; break;
+      case 23: AppModifyPath = value; break;
+      case 24: CreateUninstallRegKey = value; break;
+      case 25: Uninstallable = value; break;
+      case 26: CloseApplicationsFilter = value; break;
+      case 27: SetupMutex = value; break;
+      case 28: ChangesEnvironment = value; break;
+      case 29:  ChangesAssociations = value; break;
+      default: throw new ArgumentOutOfRangeException();
+    }
+  }
+
+  public ReadOnlySpan<byte> GetByteArray(int idx)
+  {
+    switch (idx) {
+      case 0: return _licenseText;
+      case 1: return _infoBeforeText;
+      case 2: return _infoAfterText;
+      case 3: return _compiledCodeText;
+      default: throw new ArgumentOutOfRangeException();
+    }
+  }
+
+  public void SetByteArray(int idx, ReadOnlySpan<byte> value)
+  {
+    switch (idx) {
+      case 0: _licenseText = value.ToArray(); break;
+      case 1: _infoBeforeText = value.ToArray(); break;
+      case 2: _infoAfterText = value.ToArray(); break;
+      case 3: _compiledCodeText = value.ToArray(); break;
+      default: throw new ArgumentOutOfRangeException();
+    }
+  }
+
+  public ReadOnlySpan<byte> GetPrimitive()
+  {
+    return MemoryMarshal.Cast<Primitives, byte>(new ReadOnlySpan<Primitives>(ref _primitives));
+  }
+
+  public void SetPrimitive(ReadOnlySpan<byte> raw)
+  {
+    _primitives = MemoryMarshal.Cast<byte, Primitives>(raw)[0];
+  }
+
+  #endregion
+
+  [StructLayout(LayoutKind.Sequential, Pack = 1)]
+  struct Primitives {
+    internal int NumLanguageEntries, NumCustomMessageEntries, NumPermissionEntries,
+        NumTypeEntries, NumComponentEntries, NumTaskEntries, NumDirEntries,
+        NumFileEntries, NumFileLocationEntries, NumIconEntries, NumIniEntries,
+        NumRegistryEntries, NumInstallDeleteEntries, NumUninstallDeleteEntries,
+        NumRunEntries, NumUninstallRunEntries; // Integer
+    internal InnoVersionData MinVersion, OnlyBelowVersion;
+    internal int BackColor, BackColor2; // Longint
+    internal InnoWizardStyle WizardStyle;
+    internal int WizardSizePercentX, WizardSizePercentY; // Integer
+    internal InnoAlphaFormat WizardImageAlphaFormat;
+    internal InnoSha1Digest PasswordHash;
+    internal InnoSalt PasswordSalt; // TSetupSalt
+    internal long ExtraDiskSpaceRequired; // Integer64
+    internal int SlicesPerDisk; // Integer
+    internal InnoLogMode UninstallLogMode;
+    internal InnoAutoNoYes DirExistsWarning;
+    internal InnoPrivilegesRequired PrivilegesRequired;
+    internal InnoPrivilegesRequiredOverride PrivilegesRequiredOverridesAllowed;
+    internal InnoYesNoAuto ShowLanguageDialog;
+    internal InnoLanguageDetectionMethod LanguageDetectionMethod;
+    internal InnoCompressMethod CompressMethod;
+    internal InnoProcessorArchitecture ArchitecturesAllowed, ArchitecturesInstallIn64BitMode;
+    internal InnoDisablePage DisableDirPage, DisableProgramGroupPage;
+    internal long UninstallDisplaySize; // Integer64
+    internal InnoHeaderOption Options;
+  }
+}

InnoLanguageDetectionMethod.cs

@@ -0,0 +1,5 @@
+namespace InnoPatcher;
+
+internal enum InnoLanguageDetectionMethod {
+  UILanguage, Locale, None
+}

InnoLoader.cs

@@ -70,7 +70,7 @@ sealed class InnoLoader {
 
   public Version Version => _version;
 
-  internal int Version2 => _version.Major * 1000 + _version.Minor * 100 + _version.Revision;
+  internal int Version2 => _version.Major * 1000 + _version.Minor * 100 + _version.Build;
 
   public bool IsUnicode => _isUnicode;
 
@@ -78,7 +78,7 @@ sealed class InnoLoader {
 
   public InnoSetup GetSetup() {
     _file.Seek(_offsets.Offset0 + HeaderSize, SeekOrigin.Begin);
-    if (!InnoSetup.TryParse(_file, Version2, out InnoSetup result))
+    if (!InnoSetup.TryParse(_file, Version2, out InnoSetup? result))
       throw new FormatException("Failed to parse Inno Setup");
     return result;
   }
@@ -199,7 +199,7 @@ sealed class InnoLoader {
     }
   }
 
-  [StructLayout(LayoutKind.Sequential)]
+  [StructLayout(LayoutKind.Sequential, Pack = 1)]
   struct InnoLoaderOffsetTableV6 {
     internal uint TotalSize; // Minimum expected size of setup.exe
     internal uint OffsetEXE; // Offset of compressed setup.e32
@@ -224,7 +224,7 @@ sealed class InnoLoader {
     }
   }
 
-  [StructLayout(LayoutKind.Sequential)]
+  [StructLayout(LayoutKind.Sequential, Pack = 1)]
   struct InnoLoaderOffsetTableV7 {
     internal uint TotalSize; // Minimum expected size of setup.exe
     internal uint OffsetEXE; // Offset of compressed setup.e32
@@ -248,7 +248,7 @@ sealed class InnoLoader {
     }
   }
 
-  [StructLayout(LayoutKind.Sequential)]
+  [StructLayout(LayoutKind.Sequential, Pack = 1)]
   struct InnoLoaderOffsetTableV8 {
     internal uint Version; // SetupLdrOffsetTableVersion
     internal uint TotalSize; // Minimum expected size of setup.exe

InnoLogMode.cs

@@ -0,0 +1,5 @@
+namespace InnoPatcher;
+
+internal enum InnoLogMode {
+  Append, New, Overwrite
+}

InnoPrivilegesRequired.cs

@@ -0,0 +1,5 @@
+namespace InnoPatcher;
+
+internal enum InnoPrivilegesRequired {
+  None, PowerUser, Admin, Lowest
+}

InnoPrivilegesRequiredOverride.cs

@@ -0,0 +1,7 @@
+namespace InnoPatcher;
+
+[Flags]
+internal enum InnoPrivilegesRequiredOverride {
+  CommandLine = 0x01,
+  Dialog = 0x02,
+}

InnoProcessorArchitecture.cs

@@ -0,0 +1,10 @@
+namespace InnoPatcher;
+
+[Flags]
+public enum InnoProcessorArchitecture {
+  Unknown = 0x01,
+  X86 = 0x02,
+  X64 = 0x04,
+  IA64 = 0x08,
+  ARM64 = 0x10,
+}

InnoSalt.cs

@@ -0,0 +1,9 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace InnoPatcher;
+
+[StructLayout(LayoutKind.Sequential)]
+internal struct InnoSalt {
+  internal ulong _x0;
+}

InnoSetup.cs

@@ -1,18 +1,27 @@
 using System;
 using System.Diagnostics.CodeAnalysis;
 using System.Runtime.InteropServices;
+
 using SevenZip.Compression.LZMA;
 
+using StringBuilder = System.Text.StringBuilder;
+
 namespace InnoPatcher;
 
 sealed class InnoSetup {
   private const int BlockSize = 4096 + 4;
   private const int CompressionPropertiesLength = 5;
 
+  private readonly IInnoHeader _header;
+
+  private InnoSetup(IInnoHeader header) {
+    this._header = header;
+  }
+
   internal static bool TryParse(Stream file, int innoVersion, [NotNullWhen(true)] out InnoSetup? result) {
     result = null;
 
-    byte[] headerB = new byte[Marshal.SizeOf<Header>()];
+    byte[] headerB = new byte[Marshal.SizeOf<BlocksHeader>()];
     int read, offset = 0;
     while ((read = file.Read(headerB, offset, headerB.Length - offset)) != 0)
       offset += read;
@@ -20,56 +29,294 @@ sealed class InnoSetup {
       return false;
     
     // Read header
-    Header header = MemoryMarshal.Cast<byte, Header>(headerB)[0];
+    BlocksHeader blocksHeader = MemoryMarshal.Cast<byte, BlocksHeader>(headerB)[0];
     ReadOnlySpan<byte> headerB2 = headerB;
-    if (!InnoLoader.VerifyCRC(headerB2.Slice(4), header.CRC))
+    if (!InnoLoader.VerifyCRC(headerB2.Slice(4), blocksHeader.CRC))
       return false;
 
-    if (header.Compressed != 0 && innoVersion < 4105)
+    if (blocksHeader.Compressed != 0 && innoVersion < 4105)
       throw new NotImplementedException("Zlib decompression not implemented.");
 
-    // Decode
-    Decoder decoder = new Decoder();
-    MemoryStream a = new MemoryStream();
-    byte[] blockB = new byte[BlockSize];
-    bool decoderInitialized = false;
-    for (uint toRead = header.StoredSize; toRead > 0;) {
-      int blockSize = toRead > BlockSize ? BlockSize : (int)toRead;
-      offset = 0;
-      while ((read = file.Read(blockB, offset, blockSize - offset)) != 0)
-        offset += read;
-      if (offset < blockSize)
-        return false;
+    Stream data = new FixedBlockReadStream(file, blocksHeader.StoredSize);
+    if (blocksHeader.Compressed != 0)
+      data = new CompressedReadStream(data);
 
-      ReadOnlySpan<byte> blockData = blockB;
-      uint blockCRC = MemoryMarshal.Cast<byte, uint>(blockData.Slice(0, 4))[0];
-      blockData = blockData.Slice(4);
-      
-      if (!InnoLoader.VerifyCRC(blockData, blockCRC))
-        return false;
+    // Parse
+    InnoSerializer ser = new InnoSerializer();
+    IInnoHeader header = CreateHeader(innoVersion);
+    ser.Deserialize(data, header);
 
-      if (header.Compressed != 0) {
-        if (!decoderInitialized) {
-          decoder.SetDecoderProperties(blockData.Slice(0, CompressionPropertiesLength).ToArray());
-          blockData = blockData.Slice(CompressionPropertiesLength);
-          decoderInitialized = true;
-        }
-
-        decoder.Code(new MemoryStream(blockB, blockSize - blockData.Length, blockData.Length), a, blockData.Length, 84158, null);
-      } else
-        a.Write(blockData);
-
-      toRead -= (uint)blockSize;
-    }
-
-    result = null;
-    return false;
+    result = new InnoSetup(header);
+    return true;
   }
 
- [StructLayout(LayoutKind.Sequential, Pack = 1)]
-  struct Header {
+  public string? AppName => _header.AppName;
+  public string? AppVerName => _header.AppVerName;
+  public string? AppId => _header.AppId;
+  public string? AppCopyright => _header.AppCopyright;
+  public string? AppPublisher => _header.AppPublisher;
+  public string? AppPublisherURL => _header.AppPublisherURL;
+  public string? AppSupportPhone => _header.AppSupportPhone;
+  public string? AppSupportURL => _header.AppSupportURL;
+  public string? AppUpdatesURL => _header.AppUpdatesURL;
+  public string? AppVersion => _header.AppVersion;
+
+  private static IInnoHeader CreateHeader(int version) {
+    if (version >= 6000 && version <= 7000)
+      return new InnoHeaderV6();
+    else
+      throw new NotSupportedException($"Header format for version {version} is not supported.");
+  }
+
+  [StructLayout(LayoutKind.Sequential, Pack = 1)]
+  struct BlocksHeader {
     internal uint CRC;
     internal uint StoredSize; // Total bytes written, including the CRCs
     internal byte Compressed; // True if data is compressed, False if not
   }
+
+  sealed class InnoSerializer {
+    private byte[] _buffer = new byte[512];
+
+    internal void Deserialize(Stream src, IInnoSerializable dst) {
+      StringBuilder sb = new StringBuilder();
+      for (int i = 0, j = dst.StringCount; i < j; i++) {
+        int byteLen = ReadInt32(src);
+        sb.Clear();
+        sb.EnsureCapacity(byteLen / 2);
+        ReadString(src, sb, byteLen);
+        dst.SetString(i, sb.ToString());
+      }
+
+      for (int i = 0, j = dst.ByteArrayCount; i < j; i++) {
+        int len = ReadInt32(src);
+        byte[] value = new byte[len];
+        ReadByteArray(src, value, len);
+        dst.SetByteArray(i, value);
+      }
+
+      int size = dst.PrimitiveSize;
+      if (_buffer.Length < size) {
+        int doubleSize = _buffer.Length * 2;
+        _buffer = new byte[doubleSize >= size ? doubleSize : size];
+      }
+      ReadByteArray(src, _buffer, size);
+      ReadOnlySpan<byte> buffer = _buffer;
+      dst.SetPrimitive(buffer.Slice(0, size));
+    }
+
+    private int ReadInt32(Stream a) {
+      int read, offset = 0;
+      byte[] buffer = _buffer;
+      while (offset < 4 && (read = a.Read(buffer, offset, 4 - offset)) != 0)
+        offset += read;
+      if (offset < 4)
+        throw new EndOfStreamException();
+      ReadOnlySpan<byte> buffer2 = buffer;
+      return MemoryMarshal.Cast<byte, int>(buffer2.Slice(0, 4))[0];
+    }
+
+    private void ReadString(Stream src, StringBuilder dst, int byteLen) {
+      int read;
+      byte[] buffer = _buffer;
+      ReadOnlySpan<char> bufferC = MemoryMarshal.Cast<byte, char>(buffer);
+      bool splitChar = false;
+      while (byteLen != 0 && (read = src.Read(buffer, splitChar ? 1 : 0, Math.Min(byteLen, buffer.Length))) != 0) {
+        if (splitChar)
+          read++;
+        dst.Append(bufferC.Slice(0, read / 2));
+
+        splitChar = (read & 1) != 0;
+        if (splitChar) {
+          buffer[0] = buffer[read - 1];
+          read--;
+        }
+
+        byteLen -= read;
+      }
+      if (byteLen != 0)
+        throw new EndOfStreamException();
+    }
+
+    private void ReadByteArray(Stream src, byte[] dst, int len) {
+      int read, offset = 0;
+      while (offset < len && (read = src.Read(dst, offset, len - offset)) != 0)
+        offset += read;
+      if (offset != len)
+        throw new EndOfStreamException();
+    }
+  }
+
+  /// <summary>
+  /// Reads underlying stream composed of fixed-sized CRC protected blocks.
+  /// </summary>
+  sealed class FixedBlockReadStream : Stream {
+    private readonly Stream _inner;
+    private readonly byte[] _buffer;
+    private int _bufferOffset;
+    private int _bufferLeft;
+    private uint _innerLeft;
+
+    internal FixedBlockReadStream(Stream inner, uint innerLength) {
+      this._inner = inner;
+      this._innerLeft = innerLength;
+      this._buffer = new byte[BlockSize];
+    }
+
+    public override bool CanRead => true;
+    public override bool CanSeek => false;
+    public override bool CanWrite => false;
+    public override long Length => throw new NotSupportedException();
+    public override long Position { get => throw new NotSupportedException(); set => throw new NotSupportedException(); }
+
+    public override int Read(byte[] buffer, int offset, int count) {
+      if (buffer == null)
+        throw new ArgumentNullException();
+      if (offset < 0 || count < 0 || buffer.Length - offset < count)
+        throw new ArgumentOutOfRangeException();
+      
+      int result = 0;
+      while (count > 0) {
+        if (_bufferLeft == 0) {
+          if (_innerLeft == 0)
+            return result;
+          ReadBlock();
+        }
+
+        int toCopy = count;
+        if (toCopy > _bufferLeft)
+          toCopy = _bufferLeft;
+        Buffer.BlockCopy(_buffer, _bufferOffset, buffer, offset, toCopy);
+        _bufferOffset += toCopy;
+        _bufferLeft -= toCopy;
+        offset += toCopy;
+        count -= toCopy;
+        result += toCopy;
+      }
+      return result;
+    }
+
+    public override int ReadByte() {
+      if (_bufferLeft == 0) {
+        if (_innerLeft == 0)
+          return -1;
+        ReadBlock();
+      }
+
+      _bufferLeft--;
+      return _buffer[_bufferOffset++];
+    }
+
+    private void ReadBlock() {
+      if (_bufferLeft != 0)
+        throw new InvalidOperationException();
+
+      int blockSize = _innerLeft > BlockSize ? BlockSize : (int)_innerLeft;
+      int read, offset = 0;
+      while ((read = _inner.Read(_buffer, offset, blockSize - offset)) != 0)
+        offset += read;
+      if (offset < blockSize)
+        throw new IOException();
+
+      ReadOnlySpan<byte> blockData = _buffer;
+      uint blockCRC = MemoryMarshal.Cast<byte, uint>(blockData.Slice(0, 4))[0];
+      blockData = blockData.Slice(4);
+      if (!InnoLoader.VerifyCRC(blockData, blockCRC))
+        throw new IOException();
+
+      _bufferOffset = 4; // skip CRC
+      _bufferLeft = blockSize - 4; // minus CRC
+    }
+
+    public override void Write(byte[] buffer, int offset, int count) {
+      throw new NotSupportedException();
+    }
+
+    public override void SetLength(long value) {
+      throw new NotSupportedException();
+    }
+
+    public override long Seek(long offset, SeekOrigin origin) {
+      throw new NotSupportedException();
+    }
+
+    public override void Flush() {
+      throw new NotSupportedException();
+    }
+  }
+
+  /// <summary>
+  /// Reads underlying LZMA compressed stream and decompresses it.
+  /// </summary>
+  sealed class CompressedReadStream : Stream {
+    private readonly Stream _inner;
+    private readonly Decoder _decoder;
+    private byte[]? _singleByteBuffer;
+    private MemoryStream? _singleByteStream;
+    private long _outOffset;
+
+    internal CompressedReadStream(Stream inner) {
+      this._inner = inner;
+      this._decoder = new Decoder();
+
+      byte[] props = new byte[CompressionPropertiesLength];
+      int read, offset = 0;
+      while ((read = inner.Read(props, offset, props.Length - offset)) != 0)
+        offset += read;
+      if (offset != props.Length)
+        throw new IOException();
+      _decoder.SetDecoderProperties(props);
+
+      _decoder.Code(inner, Stream.Null, -1, 0, null, noInit: false, isLast: false);
+    }
+
+    public override bool CanRead => true;
+    public override bool CanSeek => false;
+    public override bool CanWrite => false;
+    public override long Length => throw new NotSupportedException();
+    public override long Position { get => throw new NotSupportedException(); set => throw new NotSupportedException(); }
+
+    public override int Read(byte[] buffer, int offset, int count) {
+      if (buffer == null)
+        throw new ArgumentNullException();
+      if (offset < 0 || count < 0 || buffer.Length - offset < count)
+        throw new ArgumentOutOfRangeException();
+
+      MemoryStream result = new MemoryStream(buffer, offset, count, writable: true);
+      _decoder.Code(_inner, result, -1, _outOffset + count, null, noInit: true, isLast: false);
+      int read = (int)result.Position;
+      _outOffset += read;
+      return read;
+    }
+
+    public override int ReadByte() {
+      if (_singleByteBuffer == null || _singleByteStream == null) {
+        _singleByteBuffer = new byte[1];
+        _singleByteStream = new MemoryStream(_singleByteBuffer, 0, 1, writable: true);
+      }
+      _singleByteStream.SetLength(0);
+
+      _decoder.Code(_inner, _singleByteStream, -1, _outOffset + 1, null, noInit: true, isLast: false);
+      int read = (int)_singleByteStream.Position;
+      _outOffset += read;
+
+      return read == 0 ? -1 : _singleByteBuffer[0];
+    }
+
+    public override void Write(byte[] buffer, int offset, int count) {
+      throw new NotSupportedException();
+    }
+
+    public override void SetLength(long value) {
+      throw new NotSupportedException();
+    }
+
+    public override long Seek(long offset, SeekOrigin origin) {
+      throw new NotSupportedException();
+    }
+
+    public override void Flush() {
+      throw new NotSupportedException();
+    }
+  }
 }

InnoSha1Digest.cs

@@ -0,0 +1,9 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace InnoPatcher;
+
+[StructLayout(LayoutKind.Sequential, Pack = 1)]
+internal struct InnoSha1Digest {
+  internal uint _x0, _x1, _x2, _x3, _x4;
+}

InnoVersionData.cs

@@ -0,0 +1,10 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace InnoPatcher;
+
+[StructLayout(LayoutKind.Sequential, Pack = 1)]
+internal struct InnoVersionData {
+  int WinVersion, NTVersion; // Cardinal
+  ushort NTServicePack; // Word
+}

InnoWizardStyle.cs

@@ -0,0 +1,5 @@
+namespace InnoPatcher;
+
+internal enum InnoWizardStyle {
+  Classic, Modern
+}

InnoYesNoAuto.cs

@@ -0,0 +1,5 @@
+namespace InnoPatcher;
+
+internal enum InnoYesNoAuto {
+  Yes, No, Auto
+}

Program.cs

@@ -6,7 +6,8 @@ class Program {
       InnoLoader loader = InnoLoader.FromPE(exe);
       Console.WriteLine($"Inno Loader {loader.Version}" + (loader.IsUnicode ? " (Unicode)" : ""));
 
-      loader.GetSetup();
+      InnoSetup setup = loader.GetSetup();
+      Console.WriteLine($"Inno Setup {setup.AppName} [{setup.AppVersion}] ({setup.AppId})");
     }
   }
 }