MarkRobertJohnson

var ms = new MemoryStream(secureEnvelopeBytes);
var xRdr = new XmlTextReader(ms);

var message = Message.CreateMessage(xRdr, int.MaxValue, MessageVersion.Soap12);
var securityHeader = message.Headers.FirstOrDefault(x => x.Name == "Security");
if (securityHeader != null)
{
	var securityElement = XElement.Parse(securityHeader.ToString());
	var binarySecurityToken = securityElement.Descendants(
		XName.Get("BinarySecurityToken", "http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd")).Single();

MarkRobertJohnson

#requires -version 2.0
Add-Type @"
public class Shift {
   public static int   Right(int x,   int count) { return x >> count; }
   public static uint  Right(uint x,  int count) { return x >> count; }
   public static long  Right(long x,  int count) { return x >> count; }
   public static ulong Right(ulong x, int count) { return x >> count; }
   public static int    Left(int x,   int count) { return x << count; }
   public static uint   Left(uint x,  int count) { return x << count; }
   public static long   Left(long x,  int count) { return x << count; }