source: stable/HeuristicLab.ExtLibs/HeuristicLab.Cecil/0.9.5/Mono.Cecil-0.9.5/Mono.Cecil/Mono.Cecil.PE/ImageReader.cs

//
// ImageReader.cs
//
// Author:
//   Jb Evain (jbevain@gmail.com)
//
// Copyright (c) 2008 - 2011 Jb Evain
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;
using System.IO;

using Mono.Cecil.Metadata;

using RVA = System.UInt32;

namespace Mono.Cecil.PE {

  sealed class ImageReader : BinaryStreamReader {

    readonly Image image;

    DataDirectory cli;
    DataDirectory metadata;

    public ImageReader (Stream stream)
      : base (stream)
    {
      image = new Image ();

      image.FileName = stream.GetFullyQualifiedName ();
    }

    void MoveTo (DataDirectory directory)
    {
      BaseStream.Position = image.ResolveVirtualAddress (directory.VirtualAddress);
    }

    void MoveTo (uint position)
    {
      BaseStream.Position = position;
    }

    void ReadImage ()
    {
      if (BaseStream.Length < 128)
        throw new BadImageFormatException ();

      // - DOSHeader

      // PE         2
      // Start        58
      // Lfanew       4
      // End          64

      if (ReadUInt16 () != 0x5a4d)
        throw new BadImageFormatException ();

      Advance (58);

      MoveTo (ReadUInt32 ());

      if (ReadUInt32 () != 0x00004550)
        throw new BadImageFormatException ();

      // - PEFileHeader

      // Machine        2
      image.Architecture = ReadArchitecture ();

      // NumberOfSections   2
      ushort sections = ReadUInt16 ();

      // TimeDateStamp    4
      // PointerToSymbolTable 4
      // NumberOfSymbols    4
      // OptionalHeaderSize 2
      Advance (14);

      // Characteristics    2
      ushort characteristics = ReadUInt16 ();

      ushort subsystem;
      ReadOptionalHeaders (out subsystem);
      ReadSections (sections);
      ReadCLIHeader ();
      ReadMetadata ();

      image.Kind = GetModuleKind (characteristics, subsystem);
    }

    TargetArchitecture ReadArchitecture ()
    {
      var machine = ReadUInt16 ();
      switch (machine) {
      case 0x014c:
        return TargetArchitecture.I386;
      case 0x8664:
        return TargetArchitecture.AMD64;
      case 0x0200:
        return TargetArchitecture.IA64;
      }

      throw new NotSupportedException ();
    }

    static ModuleKind GetModuleKind (ushort characteristics, ushort subsystem)
    {
      if ((characteristics & 0x2000) != 0) // ImageCharacteristics.Dll
        return ModuleKind.Dll;

      if (subsystem == 0x2 || subsystem == 0x9) // SubSystem.WindowsGui || SubSystem.WindowsCeGui
        return ModuleKind.Windows;

      return ModuleKind.Console;
    }

    void ReadOptionalHeaders (out ushort subsystem)
    {
      // - PEOptionalHeader
      //   - StandardFieldsHeader

      // Magic        2
      bool pe64 = ReadUInt16 () == 0x20b;

      //            pe32 || pe64

      // LMajor       1
      // LMinor       1
      // CodeSize       4
      // InitializedDataSize  4
      // UninitializedDataSize4
      // EntryPointRVA    4
      // BaseOfCode     4
      // BaseOfData     4 || 0

      //   - NTSpecificFieldsHeader

      // ImageBase      4 || 8
      // SectionAlignment   4
      // FileAlignement   4
      // OSMajor        2
      // OSMinor        2
      // UserMajor      2
      // UserMinor      2
      // SubSysMajor      2
      // SubSysMinor      2
      // Reserved       4
      // ImageSize      4
      // HeaderSize     4
      // FileChecksum     4
      Advance (66);

      // SubSystem      2
      subsystem = ReadUInt16 ();

      // DLLFlags       2
      // StackReserveSize   4 || 8
      // StackCommitSize    4 || 8
      // HeapReserveSize    4 || 8
      // HeapCommitSize   4 || 8
      // LoaderFlags      4
      // NumberOfDataDir    4

      //   - DataDirectoriesHeader

      // ExportTable      8
      // ImportTable      8
      // ResourceTable    8
      // ExceptionTable   8
      // CertificateTable   8
      // BaseRelocationTable  8

      Advance (pe64 ? 90 : 74);

      // Debug        8
      image.Debug = ReadDataDirectory ();

      // Copyright      8
      // GlobalPtr      8
      // TLSTable       8
      // LoadConfigTable    8
      // BoundImport      8
      // IAT          8
      // DelayImportDescriptor8
      Advance (56);

      // CLIHeader      8
      cli = ReadDataDirectory ();

      if (cli.IsZero)
        throw new BadImageFormatException ();

      // Reserved       8
      Advance (8);
    }

    string ReadAlignedString (int length)
    {
      int read = 0;
      var buffer = new char [length];
      while (read < length) {
        var current = ReadByte ();
        if (current == 0)
          break;

        buffer [read++] = (char) current;
      }

      Advance (-1 + ((read + 4) & ~3) - read);

      return new string (buffer, 0, read);
    }

    string ReadZeroTerminatedString (int length)
    {
      int read = 0;
      var buffer = new char [length];
      var bytes = ReadBytes (length);
      while (read < length) {
        var current = bytes [read];
        if (current == 0)
          break;

        buffer [read++] = (char) current;
      }

      return new string (buffer, 0, read);
    }

    void ReadSections (ushort count)
    {
      var sections = new Section [count];

      for (int i = 0; i < count; i++) {
        var section = new Section ();

        // Name
        section.Name = ReadZeroTerminatedString (8);

        // VirtualSize    4
        Advance (4);

        // VirtualAddress 4
        section.VirtualAddress = ReadUInt32 ();
        // SizeOfRawData  4
        section.SizeOfRawData = ReadUInt32 ();
        // PointerToRawData 4
        section.PointerToRawData = ReadUInt32 ();

        // PointerToRelocations   4
        // PointerToLineNumbers   4
        // NumberOfRelocations    2
        // NumberOfLineNumbers    2
        // Characteristics      4
        Advance (16);

        sections [i] = section;

        if (section.Name == ".reloc")
          continue;

        ReadSectionData (section);
      }

      image.Sections = sections;
    }

    void ReadSectionData (Section section)
    {
      var position = BaseStream.Position;

      MoveTo (section.PointerToRawData);

      var length = (int) section.SizeOfRawData;
      var data = new byte [length];
      int offset = 0, read;

      while ((read = Read (data, offset, length - offset)) > 0)
        offset += read;

      section.Data = data;

      BaseStream.Position = position;
    }

    void ReadCLIHeader ()
    {
      MoveTo (cli);

      // - CLIHeader

      // Cb           4
      // MajorRuntimeVersion    2
      // MinorRuntimeVersion    2
      Advance (8);

      // Metadata         8
      metadata = ReadDataDirectory ();
      // Flags          4
      image.Attributes = (ModuleAttributes) ReadUInt32 ();
      // EntryPointToken      4
      image.EntryPointToken = ReadUInt32 ();
      // Resources        8
      image.Resources = ReadDataDirectory ();
      // StrongNameSignature    8
      // CodeManagerTable     8
      // VTableFixups       8
      // ExportAddressTableJumps  8
      // ManagedNativeHeader    8
    }

    void ReadMetadata ()
    {
      MoveTo (metadata);

      if (ReadUInt32 () != 0x424a5342)
        throw new BadImageFormatException ();

      // MajorVersion     2
      // MinorVersion     2
      // Reserved       4
      Advance (8);

      var version = ReadZeroTerminatedString (ReadInt32 ());
      image.Runtime = version.ParseRuntime ();

      // Flags    2
      Advance (2);

      var streams = ReadUInt16 ();

      var section = image.GetSectionAtVirtualAddress (metadata.VirtualAddress);
      if (section == null)
        throw new BadImageFormatException ();

      image.MetadataSection = section;

      for (int i = 0; i < streams; i++)
        ReadMetadataStream (section);

      if (image.TableHeap != null)
        ReadTableHeap ();
    }

    void ReadMetadataStream (Section section)
    {
      // Offset   4
      uint start = metadata.VirtualAddress - section.VirtualAddress + ReadUInt32 (); // relative to the section start

      // Size     4
      uint size = ReadUInt32 ();

      var name = ReadAlignedString (16);
      switch (name) {
      case "#~":
      case "#-":
        image.TableHeap = new TableHeap (section, start, size);
        break;
      case "#Strings":
        image.StringHeap = new StringHeap (section, start, size);
        break;
      case "#Blob":
        image.BlobHeap = new BlobHeap (section, start, size);
        break;
      case "#GUID":
        image.GuidHeap = new GuidHeap (section, start, size);
        break;
      case "#US":
        image.UserStringHeap = new UserStringHeap (section, start, size);
        break;
      }
    }

    void ReadTableHeap ()
    {
      var heap = image.TableHeap;

      uint start = heap.Section.PointerToRawData;

      MoveTo (heap.Offset + start);

      // Reserved     4
      // MajorVersion   1
      // MinorVersion   1
      Advance (6);

      // HeapSizes    1
      var sizes = ReadByte ();

      // Reserved2    1
      Advance (1);

      // Valid      8
      heap.Valid = ReadInt64 ();

      // Sorted     8
      heap.Sorted = ReadInt64 ();

      for (int i = 0; i < TableHeap.TableCount; i++) {
        if (!heap.HasTable ((Table) i))
          continue;

        heap.Tables [i].Length = ReadUInt32 ();
      }

      SetIndexSize (image.StringHeap, sizes, 0x1);
      SetIndexSize (image.GuidHeap, sizes, 0x2);
      SetIndexSize (image.BlobHeap, sizes, 0x4);

      ComputeTableInformations ();
    }

    static void SetIndexSize (Heap heap, uint sizes, byte flag)
    {
      if (heap == null)
        return;

      heap.IndexSize = (sizes & flag) > 0 ? 4 : 2;
    }

    int GetTableIndexSize (Table table)
    {
      return image.GetTableIndexSize (table);
    }

    int GetCodedIndexSize (CodedIndex index)
    {
      return image.GetCodedIndexSize (index);
    }

    void ComputeTableInformations ()
    {
      uint offset = (uint) BaseStream.Position - image.MetadataSection.PointerToRawData; // header

      int stridx_size = image.StringHeap.IndexSize;
      int blobidx_size = image.BlobHeap != null ? image.BlobHeap.IndexSize : 2;

      var heap = image.TableHeap;
      var tables = heap.Tables;

      for (int i = 0; i < TableHeap.TableCount; i++) {
        var table = (Table) i;
        if (!heap.HasTable (table))
          continue;

        int size;
        switch (table) {
        case Table.Module:
          size = 2  // Generation
            + stridx_size // Name
            + (image.GuidHeap.IndexSize * 3); // Mvid, EncId, EncBaseId
          break;
        case Table.TypeRef:
          size = GetCodedIndexSize (CodedIndex.ResolutionScope) // ResolutionScope
            + (stridx_size * 2);  // Name, Namespace
          break;
        case Table.TypeDef:
          size = 4  // Flags
            + (stridx_size * 2) // Name, Namespace
            + GetCodedIndexSize (CodedIndex.TypeDefOrRef) // BaseType
            + GetTableIndexSize (Table.Field) // FieldList
            + GetTableIndexSize (Table.Method); // MethodList
          break;
        case Table.FieldPtr:
          size = GetTableIndexSize (Table.Field); // Field
          break;
        case Table.Field:
          size = 2  // Flags
            + stridx_size // Name
            + blobidx_size; // Signature
          break;
        case Table.MethodPtr:
          size = GetTableIndexSize (Table.Method);  // Method
          break;
        case Table.Method:
          size = 8  // Rva 4, ImplFlags 2, Flags 2
            + stridx_size // Name
            + blobidx_size  // Signature
            + GetTableIndexSize (Table.Param); // ParamList
          break;
        case Table.ParamPtr:
          size = GetTableIndexSize (Table.Param); // Param
          break;
        case Table.Param:
          size = 4  // Flags 2, Sequence 2
            + stridx_size;  // Name
          break;
        case Table.InterfaceImpl:
          size = GetTableIndexSize (Table.TypeDef)  // Class
            + GetCodedIndexSize (CodedIndex.TypeDefOrRef);  // Interface
          break;
        case Table.MemberRef:
          size = GetCodedIndexSize (CodedIndex.MemberRefParent) // Class
            + stridx_size // Name
            + blobidx_size; // Signature
          break;
        case Table.Constant:
          size = 2  // Type
            + GetCodedIndexSize (CodedIndex.HasConstant)  // Parent
            + blobidx_size; // Value
          break;
        case Table.CustomAttribute:
          size = GetCodedIndexSize (CodedIndex.HasCustomAttribute)  // Parent
            + GetCodedIndexSize (CodedIndex.CustomAttributeType)  // Type
            + blobidx_size; // Value
          break;
        case Table.FieldMarshal:
          size = GetCodedIndexSize (CodedIndex.HasFieldMarshal) // Parent
            + blobidx_size; // NativeType
          break;
        case Table.DeclSecurity:
          size = 2  // Action
            + GetCodedIndexSize (CodedIndex.HasDeclSecurity)  // Parent
            + blobidx_size; // PermissionSet
          break;
        case Table.ClassLayout:
          size = 6  // PackingSize 2, ClassSize 4
            + GetTableIndexSize (Table.TypeDef);  // Parent
          break;
        case Table.FieldLayout:
          size = 4  // Offset
            + GetTableIndexSize (Table.Field);  // Field
          break;
        case Table.StandAloneSig:
          size = blobidx_size;  // Signature
          break;
        case Table.EventMap:
          size = GetTableIndexSize (Table.TypeDef)  // Parent
            + GetTableIndexSize (Table.Event);  // EventList
          break;
        case Table.EventPtr:
          size = GetTableIndexSize (Table.Event); // Event
          break;
        case Table.Event:
          size = 2  // Flags
            + stridx_size // Name
            + GetCodedIndexSize (CodedIndex.TypeDefOrRef);  // EventType
          break;
        case Table.PropertyMap:
          size = GetTableIndexSize (Table.TypeDef)  // Parent
            + GetTableIndexSize (Table.Property); // PropertyList
          break;
        case Table.PropertyPtr:
          size = GetTableIndexSize (Table.Property);  // Property
          break;
        case Table.Property:
          size = 2  // Flags
            + stridx_size // Name
            + blobidx_size; // Type
          break;
        case Table.MethodSemantics:
          size = 2  // Semantics
            + GetTableIndexSize (Table.Method)  // Method
            + GetCodedIndexSize (CodedIndex.HasSemantics);  // Association
          break;
        case Table.MethodImpl:
          size = GetTableIndexSize (Table.TypeDef)  // Class
            + GetCodedIndexSize (CodedIndex.MethodDefOrRef) // MethodBody
            + GetCodedIndexSize (CodedIndex.MethodDefOrRef);  // MethodDeclaration
          break;
        case Table.ModuleRef:
          size = stridx_size; // Name
          break;
        case Table.TypeSpec:
          size = blobidx_size;  // Signature
          break;
        case Table.ImplMap:
          size = 2  // MappingFlags
            + GetCodedIndexSize (CodedIndex.MemberForwarded)  // MemberForwarded
            + stridx_size // ImportName
            + GetTableIndexSize (Table.ModuleRef);  // ImportScope
          break;
        case Table.FieldRVA:
          size = 4  // RVA
            + GetTableIndexSize (Table.Field);  // Field
          break;
        case Table.EncLog:
        case Table.EncMap:
          size = 4;
          break;
        case Table.Assembly:
          size = 16 // HashAlgId 4, Version 4 * 2, Flags 4
            + blobidx_size  // PublicKey
            + (stridx_size * 2);  // Name, Culture
          break;
        case Table.AssemblyProcessor:
          size = 4; // Processor
          break;
        case Table.AssemblyOS:
          size = 12;  // Platform 4, Version 2 * 4
          break;
        case Table.AssemblyRef:
          size = 12 // Version 2 * 4 + Flags 4
            + (blobidx_size * 2)  // PublicKeyOrToken, HashValue
            + (stridx_size * 2);  // Name, Culture
          break;
        case Table.AssemblyRefProcessor:
          size = 4  // Processor
            + GetTableIndexSize (Table.AssemblyRef);  // AssemblyRef
          break;
        case Table.AssemblyRefOS:
          size = 12 // Platform 4, Version 2 * 4
            + GetTableIndexSize (Table.AssemblyRef);  // AssemblyRef
          break;
        case Table.File:
          size = 4  // Flags
            + stridx_size // Name
            + blobidx_size; // HashValue
          break;
        case Table.ExportedType:
          size = 8  // Flags 4, TypeDefId 4
            + (stridx_size * 2) // Name, Namespace
            + GetCodedIndexSize (CodedIndex.Implementation);  // Implementation
          break;
        case Table.ManifestResource:
          size = 8  // Offset, Flags
            + stridx_size // Name
            + GetCodedIndexSize (CodedIndex.Implementation);  // Implementation
          break;
        case Table.NestedClass:
          size = GetTableIndexSize (Table.TypeDef)  // NestedClass
            + GetTableIndexSize (Table.TypeDef);  // EnclosingClass
          break;
        case Table.GenericParam:
          size = 4  // Number, Flags
            + GetCodedIndexSize (CodedIndex.TypeOrMethodDef)  // Owner
            + stridx_size;  // Name
          break;
        case Table.MethodSpec:
          size = GetCodedIndexSize (CodedIndex.MethodDefOrRef)  // Method
            + blobidx_size; // Instantiation
          break;
        case Table.GenericParamConstraint:
          size = GetTableIndexSize (Table.GenericParam) // Owner
            + GetCodedIndexSize (CodedIndex.TypeDefOrRef);  // Constraint
          break;
        default:
          throw new NotSupportedException ();
        }

        tables [i].RowSize = (uint) size;
        tables [i].Offset = offset;

        offset += (uint) size * tables [i].Length;
      }
    }

    public static Image ReadImageFrom (Stream stream)
    {
      try {
        var reader = new ImageReader (stream);
        reader.ReadImage ();
        return reader.image;
      } catch (EndOfStreamException e) {
        throw new BadImageFormatException (stream.GetFullyQualifiedName (), e);
      }
    }
  }
}