title: Build PEM file by having ec public key coordinates
body: <p>I try to create an elliptic public key by calculate the point on curve from a given number ( my private key ), so I have the coordinates <code>(x,y)</code> of elliptic curve point<br></p>
  
  <p>I get the coordinates by</p>
  
  <pre><code>myPublicKeyCoordinates = myPrivateKeyValue * GPointOnCurve
  </code></pre>
  
  <p>How can i build the <code>PEM</code> ( or <code>DER</code> ) file for my public key?</p>
  
  <p>I don't care about language (<code>java, python, javascript, ...</code>) <br>
  because i want to known how build the file ( even if i write every single byte... )</p>