title: How can I convert RSA PlblicKey XML to PEM format
body: <p>I receive a RSA Key from C# server through httprequest,<p>
  But so many Encrypt lib need PEM format.<p>
  I find a solution at this<p>
  <a href="https://stackoverflow.com/questions/18835132/xml-to-pem-in-node-js">XML to PEM in Node.js</a><p>
  But I can't use it in my Javscript H5 Project, 
  Have any other solution?</p>