/// <summary>
/// Constructs the map from assembly string to its filename.
///
/// Roslyn doesn't record the relationship between a filename and its assembly
/// information, so we need to retrieve this information manually.
/// </summary>
private void SetReferencePaths()
{
foreach (var reference in compilation.References.OfType <PortableExecutableReference>())
{
try
{
var refPath = reference.FilePath;
/* This method is significantly faster and more lightweight than using
* System.Reflection.Assembly.ReflectionOnlyLoadFrom. It is also allows
* loading the same assembly from different locations.
*/
using var pereader = new System.Reflection.PortableExecutable.PEReader(new FileStream(refPath, FileMode.Open, FileAccess.Read, FileShare.Read));
var metadata = pereader.GetMetadata();
string assemblyIdentity;
unsafe
{
var reader = new System.Reflection.Metadata.MetadataReader(metadata.Pointer, metadata.Length);
var def = reader.GetAssemblyDefinition();
assemblyIdentity = reader.GetString(def.Name) + " " + def.Version;
}
extractor.SetAssemblyFile(assemblyIdentity, refPath);
}
catch (Exception ex) // lgtm[cs/catch-of-all-exceptions]
{
extractor.Message(new Message("Exception reading reference file", reference.FilePath, null, ex.StackTrace));
}
}
}
/// <summary>
/// Reads the assembly info from a file.
/// This uses System.Reflection.Metadata, which is a very performant and low-level
/// library. This is very convenient when scanning hundreds of DLLs at a time.
/// </summary>
/// <param name="filename">The full filename of the assembly.</param>
/// <returns>The information about the assembly.</returns>
public static AssemblyInfo ReadFromFile(string filename)
{
var result = new AssemblyInfo()
{
Filename = filename
};
try
{
/* This method is significantly faster and more lightweight than using
* System.Reflection.Assembly.ReflectionOnlyLoadFrom. It also allows
* loading the same assembly from different locations.
*/
using (var pereader = new System.Reflection.PortableExecutable.PEReader(new FileStream(filename, FileMode.Open, FileAccess.Read, FileShare.Read)))
using (var sha1 = new SHA1CryptoServiceProvider())
{
var metadata = pereader.GetMetadata();
unsafe
{
var reader = new System.Reflection.Metadata.MetadataReader(metadata.Pointer, metadata.Length);
var def = reader.GetAssemblyDefinition();
// This is how you compute the public key token from the full public key.
// The last 8 bytes of the SHA1 of the public key.
var publicKey = reader.GetBlobBytes(def.PublicKey);
var publicKeyToken = sha1.ComputeHash(publicKey);
var publicKeyString = new StringBuilder();
foreach (var b in publicKeyToken.Skip(12).Reverse())
{
publicKeyString.AppendFormat("{0:x2}", b);
}
result.Name = reader.GetString(def.Name);
result.Version = def.Version;
result.Culture = def.Culture.IsNil ? "neutral" : reader.GetString(def.Culture);
result.PublicKeyToken = publicKeyString.ToString();
result.Valid = true;
}
}
}
catch (BadImageFormatException)
{
// The DLL wasn't an assembly -> result.Valid = false.
}
catch (InvalidOperationException)
{
// Some other failure -> result.Valid = false.
}
return(result);
}
private static Version GetAssemblyVersion(string path)
{
if (!string.IsNullOrEmpty(path) && File.Exists(path))
{
using (var fileStream = File.OpenRead(path))
{
using (var peReader = new System.Reflection.PortableExecutable.PEReader(fileStream))
{
var mdMemoryBlock = peReader.GetMetadata();
unsafe
{
var metadataReader = new System.Reflection.Metadata.MetadataReader(
mdMemoryBlock.Pointer,
mdMemoryBlock.Length);
var asmDef = metadataReader.GetAssemblyDefinition();
return(asmDef.Version);
}
}
}
}
return(null);
}
