title: Generate HMAC-SHA256 hash with BouncyCastle
body: <p>I need to generate a HMAC-SHA256 hash in a PCL (developing for Xamarin Forms) which doesn't support the .NET built-in HMAC/cryptography classes, so I'm working with BouncyCastle to implement my cryptography classes.</p>
  
  <p>I need to generate a HMAC-SHA256 hash, but I haven't been able to find any example on Google, nor does BouncyCastle seem to have any documentation for this. Can anyone help me out?</p>