Version Info (RT_VERSIONINFO)

The RT_VERSIONINFO resource type stores metadata describing product names, version numbers and copyright holders that are associated to a Portable Executable (PE) file.

The relevant code for reading and writing version information can be found in the following namespace:

using AsmResolver.PE.Win32Resources.Version;

AsmResolver represents version metadata using the VersionInfoResource class. In the following, basic usage of this class is described.

Creating Version Info

Creating a new version info resource can be done using the constructor of VersionInfoResource:

var versionInfo = new VersionInfoResource();

By default, this creates a language-neutral version info (LCID: 0). To customize this, use the constructor overload:

var versionInfo = new VersionInfoResource(lcid: 1033);

Reading Version Info

To extract existing version information from a Portable Executable file, you will need to access the root resource directory of a PEImage. Then, the main version info directory can be obtained using the FromDirectory factory method:

PEImage image = ...;
var versionInfo = VersionInfoResource.FromDirectory(image.Resources);

If the executable contains multiple version info entries for different languages, use the FindAllFromDirectory method instead:

PEImage image = ...;
var versionInfos = VersionInfoResource.FindAllFromDirectory(image.Resources);

To retrieve version info with a specific language identifier (LCID), use the FromDirectory overload accepting an extra parameter:

PEImage image = ...;
var versionInfo = VersionInfoResource.FromDirectory(image.Resources, lcid: 1033);

Fixed File Version Info

Every version info resource starts with a fixed file version info header, exposed via the FixedVersionInfo property.

Console.WriteLine($"File Version:    {versionInfo.FixedVersionInfo.FileVersion}");
Console.WriteLine($"Product Version: {versionInfo.FixedVersionInfo.ProductVersion}");
Console.WriteLine($"Target OS:       {versionInfo.FixedVersionInfo.FileOS}");

All properties in this object are mutable, and thus can be modified to change the version info of the PE file.

String and Var Tables

Version info metadata may also contain additional string tables that can contain arbitrary strings. The way they are organized in optional blobs after the fixed version info, in good PE file format fashion with a good amount of redundancy.

String tables are stored in StringFileInfo instances, which can be created or extracted as follows:

var stringInfo = new StringFileInfo();
versionInfo.AddEntry(stringInfo);

var stringInfo = versionInfo.GetChild<StringFileInfo>(StringFileInfo.StringFileInfoKey);

A single string table can then be created as follows:

var stringTable = new StringTable(languageIdentifier: 1033, codePage: 1200);
stringInfo.Tables.Add(stringTable);

var stringTable = stringInfo.Tables[0];

String tables contain information such as product name and copyright information:

Console.WriteLine($"Product Name: {stringTable[StringTable.ProductNameKey]}");
Console.WriteLine($"Copyright:    {stringTable[StringTable.LegalCopyrightKey]}");

Each string table is accompanied with a VarTable, stored in the VarFileInfo blob, containing both the language identifier and code page:

var varInfo = new VarFileInfo();
versionInfo.AddEntry(varTable);

var varTable = new VarTable();
varTable.Values.Add(1033u | 1200u << 16);
varInfo.Tables.Add(varTable);

Writing Version Info

To serialize the (modified) version info metadata back to the resources of a PE image, use the InsertIntoDirectory method:

PEImage image = ...;
VersionInfoResource versionInfo = ...;
versionInfo.InsertIntoDirectory(image.Resources);