title: Salting a C# MD5 ComputeHash on a stream
body: <p>I can't see any way to salt a MD5.ComputeHash(Stream).
  Am I missing some way of injecting bytes into the HashAlgorithm?</p>
  
  <p>I tried performing a ComputeHash(byte[]) before performing the stream compute, but, unsurprisingly, it had no effect.  Any ideas (apart from modifying the file)?</p>
  
  <p>Thanks for your time.</p>
  
  <p><strong>addendum</strong>
  Just to be a little more specific, I want to use a stream to get a hash on a large file that I don't want to load into memory.</p>
  
  <pre><code>FileInfo myFI= new FileInfo("bigfile.dat");
  FileStream myIFS = piFile.OpenRead();
  MD5 md5 = MD5.Create();
  byte[] hash = md5.ComputeHash ( myIFS );
  myIFS.Close ();
  </code></pre>