Re: Back to Basics - Re: [PHP] Re: for the security minded web developer - secure way to login?

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Brilliant. Someone who understood my intentions :) It's not only a good
exercise but also useful. Once done in PHP and various JS frameworks, we
could port it to other languages. Would suggest to support as many as we can
because they all have pros and cons. PHP first tho :) . Maybe just good old
javascript as a start although the frameworks make it a lot easier. Who on
earth has Javascript turned off these days anyway? I don't know anyone who
is that paranoid. Sorry if someone here is but i believe if you are scared
of javascript you might as well not turn on a computer. There are always
going to be security holes.

Good on ya mate. Looks ok as an approach. Didn't look into all the details
though. I would suggest to put it under the MIT License as LGPL and GPL are
kind of restrictive as to the usage. Donations welcome of course :P.

If you want to host/version control the source code somewhere, i can offer a
git repository on my hosting or setup svn for you if you prefer that. Please
no CVS, i hate it. Just let me know if you need it.

I can also help with some development at some stage. I also believe that the
approach that i suggested would actually work well, even with a salt in the
original password hash. Maybe that salt should be hashed with a timestamp or
the same random salt as well lol. Computing a hash is not that expensive but
sending the salt might make it quite insecure because then an attacker knows
it. But i guess the salt's intension is primarily that an attacker cannot
use a pre-computed hash database from dictionaries. So maybe just sending it
is fine.

I might draw some diagrams and put them online somewhere to make it a bit
easier to understand.

Regards,
Tim

Tim-Hinnerk Heuer

http://www.ihostnz.com
Katharine Hepburn  - "Life is hard. After all, it kills you."

2009/2/16 Rene Veerman <rene7705@xxxxxxxxx>

> Just for this case, where authentication of the server isn't an issue, and
> things like deployment cost are,
>
> i'd like to propose that we on this list look again at securing login/pass
> through onewayHash functions, in an otherwise non-ssl environment.
>
> i hate to be a critic of the community here, but isn't this insistence on
> SSL a bit eh... lazy?
>
> here's a starter for a onewayHash-based login crypto:
>
> and think that with a proper layout of authentication architecture, one can
> really secure a login system without having the administrative overhead of
> installing SSL everywhere, and the monetary cost for a SSL certificate for
> each domain.
>
> I wish to code such a solution into a really-free library (so probably LGPL
> or GPL + MIT) over the next 2 to 5 months.
> This library would be a complete SQL, PHP & javascript package (jQuery
> "plugged in"), targetted for the novice programmer.
>
> I'm halfway (or more?) there, i think.
> For my own CMS, i have taken the following approach, which i'd like to hear
> your improvements on:
>
> (For onewayHash() i have MD5 and SHA256 implementations in both JS and
> PHP..)
>
> //// SQL:
>
> create table users (
> user_id                   integer,
> user_login_name      varchar(250),
> user_login_hash      varchar(250),
> user_password_hash   varchar(250),
> ....other fields....
> primary key (user_id)
> );
>
> create table preferences (
> pref_system_hash   varchar(250)
> ....
> );
>
> //// PHP (pseudo-code) , on system installation:
>  preferences.pref_system_hash = onewayHash ( randomStringLength(100) );
>
> //// PHP , on user-create:
>
>  users[user_id].user_login_hash = onewayHash(user_login_name +
> preferences.pref_system_hash);
>  users[user_id].user_password_hash = onewayHash ("someGooodPasswordNot" +
> preferences.pref_system_hash);
>
> //// PHP, on request of a login form:
>
>  challenge = makeNewChallenge ();
>      //checks since when [browser IP] has last received a new challenge, if
> < threshold : make a new challenge. else return old challenge.
>     //a challenge is a random string (+ special chars) pushed through the
> onewayHash function.
>
>  html = '
>     <form id="loginForm">
>        <input type="hidden" id="sh" name="sh"
> value="preferences.pref_system_hash">
>        <input type="hidden" id="ch" name="ch" value="challenge">
>        <input id="plain_user" name="plain_user"/>
>        <input id="plain_pass" name="plain_pass"/>
>        <input type="hidden" id="user_hash" name="user_hash"/>
>        <input type="hidden" id="pass_hash" name="pass_hash"/>
>     </form>
>  ';
>  sendHTMLtoBrowser (html);
>
> //// Javascript: on page with login form:
>
>  jQuery('#loginForm').submit (function () {
>        var sh = jQuery('#sh')[0]; //same for ch, plain_user, plain_pass,
> all the inputs in the html form.
>        ....
>
>        user_hash = onewayHash ( onewayHash ( plain_user.value + sh.value )
> + challenge );
>        //same for pass_hash basically
>
>        plain_user.value = ''; //clear out the plain text fields so they
> dont get transmitted (same for plain_pass ofcourse)
>
>        jQuery.ajax ( /* submit login form through POST, handle results */ )
>  }
>
>
> //// PHP, on receiving the login form data:
>
>     // walk through all the records in users table, for each, calculate:
>        user_hash = onewayHash ( users[user_id].user_login_hash + challenge
> );
>        pass_hash = onewayHash ( users[user_id].user_password_hash +
> challenge );
>
>     // if they match what was sent, then it's the user we're looking for
> with the right password, so their $_SESSION['authenticated_user'] = updated.
>
> ////
>
>
> If you have a completely alternative way of securing a non-ssl login form,
> i'd like to hear about it too.
>
>
>
>
> Michael A. Peters wrote:
>
>> Colin Guthrie wrote:
>>
>>> 'Twas brillig, and German Geek at 15/02/09 22:32 did gyre and gimble:
>>>
>>>> Please enlighten me why it is so expensive? Is it maybe just the hassle
>>>> of
>>>> setting it up?
>>>>
>>>
>>> The whole thing is about trust. Getting a certificate is nothing if the
>>> system is not backed up by a trust system. If a CA was setup that gave out
>>> certificates willy nilly to all and sundry, then this element of trust is
>>> lost.
>>>
>>
>> Cheap CA's do exist. They have crappy web sites and send you all kinds of
>> junk mail etc. if you use them - but they do exist.
>>
>> I might end up just paying godaddy - I think they charge $12.00 / year,
>> but since I already register through them, they already have my address etc.
>>
>> But the problem I have with FF3 is that I shouldn't have to.
>> I don't need to prove to the user that I am really me, and I don't want to
>> use a cert that some other organization has control over and can choose to
>> revoke at any time. I just the flipping password encrypted by SSL so that
>> when Betty who uses the same password for everything (it's amazing how many
>> people do) logs onto my server while she has coffee at Starbucks, her
>> uname/password isn't sniffed giving Cracker Jack access to Betty's PayPal
>> account.
>>
>> If Cracker Jack wants to do a man in the middle attack - as long as Betty
>> has already connected to me before, her browser will still inform her that
>> the certificate doesn't match - whether or not I am self signed, so the man
>> in the middle attack is really not the big deal FireFox makes it out to be.
>>
>> What they should do is a simple notification telling the user they can't
>> verify the website is who it claims to be, and a link for more info if the
>> user wants more info.
>>
>> But alas, that has nothing to do with php, so I apologize to the list.
>>
>> Anyway, back on topic - if you want to encrypt login, use SSL.
>> You can self sign for free.
>> If you don't want the FireFox 3 issue, there are a few free and plenty of
>> cheap certificate authorties that FireFox recognizes.
>>
>>
>
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