main.js

var gmail = null;
/*
 * Wait for the Gmail object to be ready
 */
function refresh(f) {
    if ((/in/.test(document.readyState)) || (typeof Gmail === undefined)) {
        setTimeout('refresh(' + f + ')', 10);
    } else {
        f();
    }
}

var check_failure = function() {
    var id = null,
        raw_email = null,
        spoof = false;

    console.log('[Phish Detect] Scanning email...');

    // Get the email ID from the url
    id = window.location.hash.split('/').pop(),

        // Get the "original email", which contains headers
        raw_email = gmail.get.email_source(id),

        // Check for softfail and hardfail
        spoof = (/=fail/.test(raw_email) || /=softfail/.test(raw_email) || /=neutral/.test(raw_email));

    // If failure, alert user
    if (spoof) {
        alert('This email may be a phishing attempt. Please take caution when handling the contents of the email, such as clicking links.');
        console.log('This could be a phishing email!');
    } else {
        alert('not a phishing email');
    }
};

var main = function() {
    console.log('[Phish Detect] Gmail object defined. Ready to protect.');

    gmail = new Gmail();
    gmail.observe.after('open_email', check_failure);
};

// Wait for for document and Gmail objects to be ready
refresh(main);