title: How can I read confidence data (password) in a Chrome extension?
body: <p>I'm trying to improve this <a href="https://chrome.google.com/webstore/detail/cplkacpelaknlngmmhfkhoanmlfgjokf" rel="nofollow">Chrome extension</a>
  to add the following functionality.</p>
  
  <p>When the user click or focus on a password box ( <code>&lt;input type="password" /&gt;</code>), a dialog appears. The user can type in his password. After that the extension automatically calculate encrypted password, and fill into the password box.</p>
  
  <p>Firstly, I implement it by modifying DOM, add a jQuery UI dialog. But I realize that this may have some security risk. The web page can iterate through the whole page, find my password box and get its value. Is this right? If is, how can I read password safely?</p>
  
  <p>I also try to find a way to programmatically "click" the page action or browser action to show a password box. But seems forbidden by Chrome. No such interface.</p>