Script for CIRC running on Chrome/Chromium based on https://github.com/flackr/circ/tree/master/example_scripts (password does not persist if you uninstall and install this script)

auto_identify.js

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//jslint vars:   true // change from block comment to line comment if you want to ignore a jslint option
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/*jslint debug:  true */
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/* change from block comment to line comment when running jslint
function setName() {} function setDescription() {} function send() {} function loadFromStorage() {} function updatePasswords() {} function handlePrivateMessage() {} function propagate() {} function shouldAutoIdentify() {} function autoIdentify() {} function nickServPasswordIsVisible() {} function snoopPassword() {} function hideNickServPassword() {} function saveToStorage() {} function getHiddenPasswordText() {} function sendEvent() {}
*/
//change above from block comment to line comment when running jslint

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setName('auto_identify');
setDescription('hides NickServ password and automatically identifies on startup');

send('hook_message', 'privmsg');
loadFromStorage();

// Keeps track of the last NickServ password used in each server.
var serverPasswords = {};

this.onMessage = function (e) {
  if (e.type === 'system' && e.name === 'loaded' && e.args[0]) {
    updatePasswords(e.args[0]);
  } else if (e.type === 'message' && e.name === 'privmsg') {
    handlePrivateMessage(e);
  } else {
    propagate(e);
  }
};

var handlePrivateMessage = function (event) {
  var source = event.args[0], message = event.args[1];
  if (source.toLowerCase() !== 'nickserv') {
    propagate(event);
  } else if (shouldAutoIdentify(event.context, message)) {
    propagate(event);
    autoIdentify(event.context, message);
  } else if (nickServPasswordIsVisible(message)) {
    propagate(event, 'none');
    snoopPassword(event.context, message);
    hideNickServPassword(event);
  } else {
    propagate(event);
  }
};

var shouldAutoIdentify = function (context, message) {
  return message.indexOf('nickname is registered') >= 0 &&
      serverPasswords[context.server];
};

var autoIdentify = function (context) {
  //message is not used - jonasbits
  var pw = serverPasswords[context.server];
  send(context, 'message', 'notice', 'Automatically identifying nickname with NickServ...');
  send(context, 'command', 'raw', 'PRIVMSG', 'NickServ', '"identify', pw + '"');
};

var nickServPasswordIsVisible = function (message) {
  var words = message.split(' ');
  return words.length === 2 && words[0].toLowerCase() === 'identify';
};

var snoopPassword = function (context, message) {
  var password = message.split(' ')[1];
  serverPasswords[context.server] = password;
  saveToStorage(serverPasswords);
};

var hideNickServPassword = function (event) {
  var words = event.args[1].split(' ');
  words[1] = getHiddenPasswordText(words[1].length);
  event.args[1] = words.join(' ');
  sendEvent(event);
};

var getHiddenPasswordText = function (length) {
  var hiddenPasswordText = '', i = 0;
  for (i = 0; i < length; i += 1) {
    hiddenPasswordText += '*';
  }
  return hiddenPasswordText;
};

var updatePasswords = function (loadedPasswords) {
  var server;
  for (server in loadedPasswords) {
    if (loadedPasswords.hasOwnProperty(server)) {
      if (!serverPasswords[server]) {
        serverPasswords[server] = loadedPasswords[server];
      }
    }
  }
};