How to logout when using .htaccess (and .htpasswd) authentication? [duplicate] - php

This question already has answers here:
Closed 13 years ago.
Possible Duplicate:
HTTP authentication logout via PHP
Hi
I have a some functionality on my website protected using .htaccess and .htpasswd.
When users attempt to access this, they get prompt to enter details. They enter their details and get in and can see stuff etc. All works fine.
My question is how do I create a logout functionality for this type of authentication. I know that they can close the browser window to "Logout". But this is not ideal. What would you suggest to me?
Thanks.

Tested on firefox and chrome. What you can do is send the user to http://logout:logout#example.com. This will replace their current username/password with logout/logout (it could be any invalid user/pass combination) and since they now have the wrong username/password, they will have to login again to access the site.
On opera this does not work, because you can have several usernames/passwords at the same time. It didn't work on IE either, because IE does not appear to support http://username:password#example.com URLs.

Browsers usually don't support this, see How do I log out?
Since browsers first started
implementing basic authentication,
website administrators have wanted to
know how to let the user log out.
Since the browser caches the username
and password with the authentication
realm, as described earlier in this
tutorial, this is not a function of
the server configuration, but is a
question of getting the browser to
forget the credential information, so
that the next time the resource is
requested, the username and password
must be supplied again. There are
numerous situations in which this is
desirable, such as when using a
browser in a public location, and not
wishing to leave the browser logged
in, so that the next person can get
into your bank account.
However, although this is perhaps the
most frequently asked question about
basic authentication, thus far none of
the major browser manufacturers have
seen this as being a desirable feature
to put into their products.
Consequently, the answer to this
question is, you can't. Sorry.
There are browser extensions that allow you to clear the HTTP authentication for a site.
For Firefox the WebDeveloper extension (which is one of my favourtie extensions anyway) offers this feature.
The menu for this is Miscellaneous/Clear Private Data/HTTP Authentication.

I ran into this issue several years ago. It is incredibly frustrating to discover there is a problem everyone is having and no one seems to want to solve in a general way.
As noted in Inadequate Logout functionality in HTTP Authentication I think the answer is to change the RFC to allow timeouts and support a log out button. The author's additional suggestion that the server be able to send a "log out" header would actually eliminate the need for any client user agent support since websites could simply include a link on a web page to a URL that returns the necessary response code and/or header to invalidate the current session.

It IS kind of possible to log out. You should implement logout page, which will return HTTP 401, until the user enter BAD login information, and then redirect somewhere else. Browser remembers the latest login information accepted, and therefore overrides correct login.
But this is kinda unusable, cos it needs user's cooperation.

Related

Loggin a user out of a database on browser close PHP/MySQL

I have seen MANY questions on this before online in many places, however, out of about 30 forums and whatnot, NONE of them have had the solution I need, and that includes stackoverflow. If anyone could help me find a reliable solution, it would be greatly appreciated, so thanks in advance!
I'm going to explain my site and situation with as much detail as possible in order to help any who want to help answer my questions. Here is my situation:
I have a website and I use PHP and MySQL. My website is a "private" organization site. In order to allow people access to the site, I send new members of our organization and invite code. The user then visits the website, and the index.php file simply contains a form for logging in as well as a link to the registration pages. New members click the "Register Here" link to begin registration. The first registration page asks for the user's last name and invite code which are checked against a database to make sure that person is on the list and has not yet registered. If they pass the check, they are taken to the next page in which they enter required information (username & password, email address, etc.) as well as some optional information (phone, bio, etc.). If the user creates a valid username and password and has all required fields filled out, their information is stored in a database. Passwords are all salted and hashed properly and securely, so there is no problem there, and the whole registration process works as it should. After registering, the user is taken back to index.php where they can now log into using the username and password they just created. This works as well; when the user logs in, their username and password are checked against the database, and if successful, the user is logged in. When the user is logged in, an ONLINE value in the database is set from False to True. The user is now logged in and can use the site as it is intended. On my site, there is a column that lists users that are currently online (based on the ONLINE value from the database). When the user clicks the "Log Out" button which is located on every page of the site, the logout.php script is run, ending the session and setting the ONLINE value back to False. This all works fine and dandy, however, the problem comes when the user closes the browser without logging out first. This is where I have seen many different "solutions" various places on the internet. I am going to explain why they won't work and why I need a better solution.
The answers I see most often involve some sort of session timeout or destroying sessions, which is irrelevant because of the fact that the session already does, in fact, end when the user closes the browser, but that has no effect on telling other users whether or not that person is currently online. When the session ends, the database won't be updated, which causes a problem due to the fact that a user can only be logged in from a single instance. If a user attempts to log in while their ONLINE value is already set to TRUE, they aren't allowed to log in.
I have also seen suggestions of using a "Last Seen" value instead of an online value, and if a user hasn't had any activity within the past x amount of minutes, log the user out. This won't work, however, for two reasons. 1) That script still has to be running somewhere in order for that to work, meaning another user must be logged in for that to work. That basically means that, if using this method, if a user closes their browser or if they loose connection, they won't be able to log back in until another user logs in. With my organization being a small, locally based organization as it is, there are likely to be many times in which there are no users online. Also, even if another user is logged in, the user whose connection was lost still won't be able to log back in until after x amount of minutes has passed, so if the user accidentally closed their browser and wanted to log back in immediately, they simply wouldn't be able to.
A less frequent solution I came across involved using the onBeforeUnload JavaScript function, but those most definitely will not work due to the fact that those would trigger any time a user clicked on a link or on the "Back" and "Forward" buttons. Also, if the user has JavaScript disabled in their browser, this will not work at all.
The last thing I have seen involves while loops and the connection_aborted function, and this is the only one that seems like it could work, yet I have not seen a very clear description of how this should work, and after spending months experimenting with it, I still have not come up with a reliable solution.
In many forums, I have seen people say that "it's not possible," but that can't be the case considering there are sites that do it somehow. I have tested and experimented with this on several sites. On a site that has users such as Facebook or any forum website, there is a list of "online" users, and in the case that a user closed their browser, their name would no longer appear on the list, so it is possible, even if it can only be achieved through some obscure method. So, if anyone knows of a solution, I would greatly appreciate if you could share some of your wisdom on this subject!
Try creating a Heartbeat mechanism in javascript.
this method would start sending an ajax call to your webmethod on timely basis use.
setInterval(function(){
sendPulse();
},30000);
sendPulse(){
var varUserID = userID;//any unique user identifier that can be found on server side
$.ajax({
url: "Default.php/updateUserStatus",
UserID: varUserID,
type: "POST",
dataType: "json",
contentType: "application/json; charset=utf-8",
success: function (mydata) {
//alert("pulse sent");
}
});
}
On server side, you must have a method with same name and case sensitive parameter. the should be static and marked as webmethod. in this method save the current time for the user. you should have a mechanism to know what users have very old pulse, do this check when a user tries to do something or performs any operation. I have implemented this approach and works very well.
That's the answer: persistent connection between client and server. For this, you will need a TCP connection, like websockets nowadays, or a flash old duplex connection. From here on, TCP takes care of noticing you when someone connects or disconnects. What you got to do is a websocket server (for example) who just traks connections (push and pop from an array), and also a way to respond to a "get_users_online" message. You can access your user's session (read only) via the websocket server, and then see if the user is logged-in (and in this way, you can store his nickname in session, access further from websocket server), see if he is admin (session->is_admin).
Pretty simple, I would say.
Here is the library I've been using: http://socketo.me/ . It uses a library for decoding symfony2 sessions, but for simple applications, you don't need decoding (symfony2 applications encodes sessions, so the websocket server has to decode them).
Big note: Sessions has to be stored externally (not in file system /tmp) like a ORM or NoSql.
Either way, escuse me, but I have to say that that the "Last time" seen is super okey. Most of the sites rely on this. You understood something wrong, you don't need to have a living server for checking "Last time" always, when you request /admin.php?users_online=1 , you make a query where "Last seen > NOW() - 5 minutes" (won't work written like that), so you can even get rid of the "ONLINE" "OFFLINE" field.
I suggest using a websocket approach, it's fun. :)
Good luck!

Only allow access to PHP file through application [duplicate]

This question already has answers here:
Prevent direct access to a php include file
(33 answers)
Closed 9 years ago.
I have a PHP file that queries my database and then returns information in XML format back to my application. Right now, if I just go to the URL in the browser and put in the proper parameters in the URL, the information is shown right to me. Is there a way that I can make the PHP page ONLY accessible through the application(iOS and Android)? I have searched, and the only thing that I can find is making the page only accessible through includes, but I don't see how this would restrict the access if the person figured out the php page that included the file. Any suggestions are appreciated!
Thanks
Almost any restriction you put on it will essentially come down to "Put something in the request that only the application will send".
The basic approach would be "Keep the URL secret". If only the application knows about it, then only the application can make a request to it. Anything else (passwords, API keys, custom HTTP headers, user-agent sniffing, etc) is just complexity around the same concept.
Making the request over HTTPS instead of HTTP will protect the secret from exposure to sniffing.
Nothing can save you from decompilation though.
You could add a custom http header in your client request inside your app with a challenge code. Your script detects the header and verifies the challenge. If the verification is passed, you execute the script, otherwise you return a 403 Forbidden.
Rather not. In fact everyone can insert false data in his browser information and you wouldn't find out if this is Microsoft Internet Explorer on Windows 95 or Chrome on Android phone.
You may try to block by IP number, but this is not blocking application, but the user.
The only idea I have is to use some user/password login things, which only your application would know, but it has its own security holes (like man-in-the-middle).

Ask for HTTP authentication only when user is trying to authenticate

What I think of is detecting authentication attempt and logging user in using PHP and standart HTTP credentials without bugging him with popup, when he does not try to login. That may sound easy, but we must keep in mind, that browsers check whether site is requesting authentication, and when it does not, they are bugging user with warning and they also send no data.
Is there any bypass? Any trick?
QUESTION SUMMARY:
I want url http://example.com/site to work wihout any promts and popups. User will see the site as anonymous.
I want url http://user:password#example.com/site to work without any popups too. User will see the site as user
To answer your question: no there is no way around it. The browser will not send the authentication information if it has not been requested by the website, and as you have discovered, it will also show an annoying security warning to the user. You should bite the bullet and use a GET param.

Automated Download of URL Content from site requiring cookies

I'm attempting to automatically download content at regular time intervals from a site requiring users to log in. The content I'm seeking to download is a small .js file (<10 kb).
As the site will display the desired data only when I'm logged in, I'm unable to simply use functions such as urlwrite (in MATLAB) to download the data.
I'm not sure whether the libcurl library in PHP would be able to solve the problem easily.
As suggested in the answer to this similar question (Fetching data from a site requiring POST data?), I've tried to use the Zend_Http_Client, but haven't been able to get it to work.
In summary, I'd like help on automatically downloading URL content from a site requiring user log-in (and presumably submission of cookies).
In addition to this, I'd appreciate advice on which software is best for automated download of such data at regular time intervals.
(If you do require the exact URL I am trying to download from to test a solution, please leave a comment below.)
It depends on the type of login the site uses. If it uses HTTP authentication you use curl option CURLOPT_HTTPAUTH (see setopt, http://php.net/manual/en/function.curl-setopt.php) Otherwise, as said, you use COOKIEJAR and possible COOKIEFILE.
Another option is the standalone utility wget. The FAQ contains a nice explanation of both login methods http://wget.addictivecode.org/FrequentlyAskedQuestions#password-protected
If this is the first time you use curl: don't forget to set CURL_RETURNTRANSFER to true (if false the content is send to stdout) and CURL_HEADER to false to get the content without headers.
I your only concern is login, rather than cookies in general. Check the answer to this question : How do I use libcurl to login to a secure website and get at the html behind the login

Any idea how to do (1) php authentication (2) launch a flex app which knows the user has already been authenticated

Almost everything is in the title :
Here's what I'd like to do :
A nice html page with a php authentication process (http first then https & so on)
Launch a flex app which knows (I don't know how (this is the actual question !)) the user has already been authenticated and display his/her stuff he/she has to do for the day (or whatever...).
Of course if someone try to call directly the flex app I would display an "authentication error" message and then redirect to the authentication page.
I'm sorry for my English which is perfectible.
I was thinking about the session cookie : first authenticate then ass a variable on the server side, something like :
$_SESSION['authenticate']=true
Then, on the flex side, just send the cookie and ask if the user is properly authenticated, something like calling a php web page like :
https://is_authenticated.php?php_session=xxxx
Thank you
Olivier
What are you using on the server side? Remember that you shouldn't do anything in the flex application other then send the SESSION ID along with any requests. Any time where the client checks security, you have a bug. The server must validate the session and determine if the request is allowed.
It sounded in your last comment that you are worried about people manually calling a web page. Each page must check to see if the user is authenticated. I don't know your specific application, but you may try looking at AMFPHP and see how they do session authentication. Good luck!
Your on the right track!
You could use session-authentication, these links might help you out:
http://www.zend.com/zend/spotlight/sessionauth7may.php
http://www.tizag.com/phpT/phpsessions.php
There is also the possibility to use http-authentication
http://se2.php.net/features.http-auth
however http-authentication is not as flexible as session-authentication, and also means some more configuration on the serverside.I would therefore recommend you to stick with sessions.
This is exactly what I would do.. A few things to consider from a security standpoint:
If your php service (from flex) gets an unknown session token, always generate a new one. This also applies to your PHP application and is often overlooked.
I would generate the swf with javascript, and manually insert the session cookie using javascript. This way people won't download and safe (or cache) your php pages with sessions that are invalid in the future.
Even better would be to use a separate token other than the session, and on the server figure out what the session id was based on this flex token.

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