title: How do you create an instance of RsaSecurityKey from a SSL key file
body: <p>I have a RSA private key in the format as stated in <a href="https://www.rfc-editor.org/rfc/rfc7468#section-10" rel="nofollow noreferrer">RFC 7468</a> and a library I'm using requires an instance of <code>SecurityKey</code> none of the constructor's seem to accept strings in this format, nor any of the accepted arguments for it's constructor seem to accept this format.</p>