Facebook SDK for Unity not executing piped commands

I'm trying to get the Facebook SDK for Unity running, but it seems to be bugged at some places(even with the latest build and latest Unity install).

The bug I'm concerned with - and this seems to be more of a general Mono/C#/.NET problem - is that when they try to check if openSSL is installed they try to execute a piped command which seems to cause some problems with System.Diagnostics.Process. The code is as follows:

         // This is abbreviated code to show the use case.
         command = "echo \"xxx\" | openssl base64";
         var proc = new Process();
         proc.StartInfo.FileName = "cmd";
         proc.StartInfo.Arguments = "/C \"" + command +"\"";
         proc.StartInfo.UseShellExecute = false;
         proc.StartInfo.CreateNoWindow = true;
         proc.Start();
         proc.WaitForExit();
         
         // Process code is 1

Though if I execute this command in cmd/bash/sh it executes fine. And if I split the command it is again executed in C# - but then without the pipe operator. There's another command that uses piping which again does not work.

My PATH is properly set-up as you can see here: C:\Program Files\Sublime Text 2;C:\Program Files\Java\jdk1.7.0_07\bin;C:\Program Files\MongoDB 2.6 Standard\bin;C:\Program Files (x86)\Git\bin;C:\OpenSSL-Win32\bin;C:\Windows\System32

My question is, it seems that many people got this package working. Is it just my machine, did I forget something? Is there a simple solution to fix this?

A big thanks in advance.