Question

I want to read an exe file in my C# code then decode as base64.

I am doing it like this

FileStream fr = new FileStream(@"c:\1.exe", FileMode.Open, FileAccess.Read, FileShare.Read);
StreamReader sr = new StreamReader(fr);
fr.Read(data, 0, count);

But the problem is that when I write this file the written file gets corrupted.
When analyzing in hex workshop code value 20 in hex is being replaced by 0.

Answer 1

A StreamReader should be used only with text files. With binary files you need to use directly a FileStream or:

byte[] buffer = File.ReadAllBytes(@"c:\1.exe");
string base64Encoded = Convert.ToBase64String(buffer);
// TODO: do something with the bas64 encoded string

buffer = Convert.FromBase64String(base64Encoded);
File.WriteAllBytes(@"c:\2.exe", buffer);