title: Session lost when redirect from Facebook's login at https when developing an iPhone app
body: <p><strong>Hi</strong>, everyone</p>
  
  <p>I am developing an iPhone app which could login with Facebook, Twitter account by users.</p>
  
  <p>I am using the server-side flow to deal with the login process.<br>
  Of course, I also set the <em>Website URL</em> at Facebook(oauth2.0) side and <em>Callback URL</em> at Twitter(oauth1.0a) side and with no problem when using <em>http</em>.</p>
  
  <p>Our company contracted for a ssl. Then, I changed the <em>http</em> to <em>https</em> in the Facebook side or Twitter side, and changed my post url for login from <em>http</em> to <em>https</em>.<br>
  But when redirect from theirs login screen, I lost all data in session which I stored such as token information before login.</p>
  
  <p>For test, I am also using browser(IE) to check the login behavior, and it has no problem both at <em>http</em> and <em>https</em> cases.</p>
  
  <p>Bay the way, whatever the client is browser(IE) or iPhone app, the server-side source code is the same.</p>
  
  <p>So what is the problem, please?</p>