title: What is Peer Certificate?
body: <p><a href="https://stackoverflow.com/questions/21264255/how-to-make-https-post-request-from-android-to-different-port-not-443">I have this problem</a> with HTTPS requests on android - <em>No peer certificate</em>. I've mentioned that Google are flood with people's question about this problem. Sad enough that <strong>NONE</strong> of that question has answer which works for me.</p>
  
  <p>But at least I want to know a <strong>cause</strong> of that error. I couldn't even find what is it - peer certificate. And when that error could appear? I have error even on normal secured sites which has valid certificate. Why is it invalid when doing request from android?</p>
  
  <p>P.S. I don't want to see answers like "you should trust all certificates". No, I shouldn't. I want my application act like normal browser which works silently when certificate is valid otherwise notify user about certificate problem.</p>