LoginProcess

Steps:

1.  POST form.elements['username'].value to https://steamcommunity.com/login/getrsakey/
    var results = transport.responseJSON;
    var pubKey = RSA.getPublicKey( results.publickey_mod, results.publickey_exp );
    var encryptedPassword = RSA.encrypt( form.elements['password'].value, pubKey );

2.
var results = transport.responseJSON;
    POST
        password: encryptedPassword,
        username: form.elements['username'].value,
        emailauth: form.elements['emailauth'].value,
        captchagid: form.elements['captchagid'].value,
        captcha_text: form.elements['captcha_text'].value,
        emailsteamid: form.elements['emailsteamid'].value,
        rsatimestamp: results.timestamp
    to https://steamcommunity.com/login/dologin/

3.
var results = transport.responseJSON;
    if ( results.login_complete ) { good }
    else
        if ( results.captcha_needed && results.captcha_gid )
        else if ( results.emailauth_needed )
            {
                if this happens, the user gets an e-mail. We can set
                    "document.forms['logon'].elements['emailauth'].value = $('authcode').value;"
                and all will be well
            }