Get assembly linker timestamp

AssemblyExtensions+LinkerTimestamp.cs

using System;
using System.Collections.Concurrent;
using System.IO;
using System.Reflection;
 
public static class AssemblyExtensions
{
    private const int PortableExecutableHeaderLocationOffset = 60;
    private const int LinkerTimestampLocationOffset = 8;
 
    private static readonly ConcurrentDictionary<Assembly, DateTime?> LinkerTimestampCache =
        new ConcurrentDictionary<Assembly, DateTime?>();
 
    public static DateTime? GetAssemblyLinkerTimestamp(this Assembly assembly)
    {
        return LinkerTimestampCache.GetOrAdd(assembly, GetAssemblyLinkerTimestampInternal);
    }
 
    private static DateTime? GetAssemblyLinkerTimestampInternal(Assembly assembly)
    {
        string filePath;
 
        try
        {
            filePath = assembly.Location;
        }
        catch { return null;}
 
        if (string.IsNullOrWhiteSpace(filePath)) { return null; }
 
        var buffer = new byte[2048];
        int bytesRead;
 
        try
        {
            using (var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read))
            {
                bytesRead = fileStream.Read(buffer, 0, buffer.Length);
            }
        }
        catch { return null; }
 
        if (bytesRead < PortableExecutableHeaderLocationOffset + 4) { return null; }
 
        var portableExecutableHeaderLocation = BitConverter.ToInt32(buffer, PortableExecutableHeaderLocationOffset);
        var linkerTimestampLocation = portableExecutableHeaderLocation + LinkerTimestampLocationOffset;
 
        if (bytesRead < linkerTimestampLocation + 4) { return null; }
 
        var linkerTimestamp = BitConverter.ToInt32(buffer, linkerTimestampLocation);
        var convertedLinkerTimestamp = new DateTime(1970, 1, 1, 0, 0, 0).AddSeconds(linkerTimestamp);
        var localLinkerTimestamp = convertedLinkerTimestamp.ToLocalTime();
 
        return localLinkerTimestamp;
    }
}