I want my users to have secure session on my website. What must i store in cookie to recognise each user?
Every time user logs in, cookie value must be changed.
P.S. I want to make a database with cookie values which link to user id.
a session id?
You should store a session ID in the cookie. That said, you should NOT have to do this yourself. Use PHP sessions, it does all the cookie handling for you.
Why do you need to store the session IDs in a database? If you need semi-temporary data to travel with the user during their session, you can use the $_SESSION variable for that. It is documented as part of the guide above.
PHP does not have native support for storing session IDs on the server in a database, you would have to write that yourself, or use a library that already provides that functionality, like CakePHP.
A cookie should be a cryptographic nonce that is used to reference server side state. IE: A session id. All web application platforms have their own session handler. In php you just call session_start() and then use the $_SESSION[] super global.
Related
I am using PHP and Codeigniter to do this. Currently I am just saving a cookie to the user with their username and a $logged_in variable set to true. Then when they try to access a page, I check for the status of their $logged_in, and if they are, they're free to access.
It occurs to me that this may not be the safest way to go about this. Is there a better tactic I should be using?
It's not safe at all. Cookie is considered user input and it can't be trusted in any case.
Use sessions instead.
Also you could use some sort of custom login encrypted code (I'd personally suggest SHA1) that is matched against the login code in the database and is refreshed every, let's say, 5 minutes.
CodeIgniter offers a nice solution to this problem - You can use Database Sessions.
With Database Sessions, all the data you put in a session is stored within your SQL database. The user gets a cookie with a unique session ID that changes on a regular basis. The session ID along with IP and User Agent is used to match up the user with their session data, thus making it impossible for users to tamper with their own session data, and very hard for them to hijack someone else's session.
You can read more about CodeIgniter Database Sessions in the CodeIgniter User Guide.
I'm going to use Codeigniter's session data for my login system, but first I wanted to understand them, so I read the user guide, and from what I understand, Codeigniter's session data are just cookies.
Is this true? which means if the user disables cookies he wont be able to login to any website using Codeigniter's session data?
quoted:
The Session class stores session information for each user as serialized (and optionally encrypted) data in a cookie
So that means I should create my own native PHP session data to make users who disable cookies able to login my website? or Codeigniter's session data are not just cookies?
Yes, the CodeIgniter's inbuilt session class does use cookies, however, even the standard Sessions in PHP need cookies.
Thus, no matter which route you go, CodeIgniter Session, or the standard Session, either ways if the user does not have cookies enabled, Sessions won't work.
The advantage of CodeIgniter's Session class is it automatically encrypts the data as well to prevent cookie tampering, plus allows you to authenticate the cookie against a database.
Sessions in CodeIgniter or any other application using HTTP protocol are best kept track of using cookies. Normally, the session data itself is not stored using cookies, but a key to access this data is, whether the actual session data is stored in server's filesystem or in a database.
PHP allows to set session ID through cookies, POST or GET, but it is preferable to always use cookie or you will be opening doors to session fixation using ini_set('session.use_only_cookies', true). Practically everybody do have cookies enabled.
I am trying to understand security when it comes to session cookies in php. I've been reading a lot about it, but I still lack the specifics. I need the basics, someone to show examples.
For example: Do I place session_regenerate_id() before every session cookie? What more shall I think about. I am asking about specifics in code - examples if possible.
Thank you very much.
I am using 4 session cookies after logging in.
SESSION "site_logged_in" = true
SESSION "site_user_nr" = the number of the user to access user_table_nr
SESSION "site_user_id" = the user's id to use when changing data in tables
SESSION "site_user_name" = the name of the user to display on page
When I check if the user has access, I check if all 4 cookies are set, and if site_logged_in is set to true.
Are there better ways? Do I have the completely wrong idea about this? Can users easily be hacked?
In fact you need to have only one session in your website. When you call session_start() session is being created on server and user automatically gets session cookie. Think like session is a some sort of container that placed on the server, you can put whatever you want in that container. However session cookie is just a key to access that container on the server.
It means that you can safely put some data in the $_SESSION and only the user that have cookie with matching session id can read it.
About users being hacked. Yes they can be hacked as long as you don't use HTTPS connection, because cookies and all other data is being transferred in clear text, so if someone intercept users cookie he can access the data stored in the session.
Always use a security token for logging users. This security token could be generated by using crypt(). After logging users in, change the security token periodically until they log out. Also keep the server backup of all the session variables including the security token (in a database). This would also help you to track user login history.
One more personal suggestion: Never use any data from the database as session variables without encrypting it with any of the hashing functions or functions like crypt().
The session information is stored server-side. What you should check is that they're logged in, and that they exists/can log in (in case of deletions/bans).
As you're checking they exist/can log in, you can pull the other information from the database such as name, nr and so on. All you really need is a key called 'logged_in_user' or something that stores the ID of the logged in user. As Alex Amiryan said, the cookie can be copied, so you might also want to store the IP address of the last accessing view in the session, so you can try to ensure security.
Sorry for the newbie question! I'm making a small website that allows users to create their own accounts. It's not a banking system, and it's unlikely that someone would want to hack it. That said, I am trying to make it reasonably secure, as there are plenty of bored script kiddies out there.
Could someone describe a basic workflow for a user logging in and having a cookie set that will keep them logged in for 30 days?
At the moment I have the following:
Validate and sanitize inputted data.
Check supplied credentials against bcrypt hashed password in DB.
If correct then call "Login" function.
Login function:
a. Delete any session data from DB with userID (table with two columns: SessionString and UserID).
b. Add new session data to DB (newy random generated string and UserID).
c. Write random generated string and UserID to cookie.
d. Set $_SESSION("UserID") with $userID.
But although the two cookies are being created and written to, the $_SESSION("UserID") remains blank... I'm guessing because I can't write to $_SESSION any time I like?
And even once that's fixed, how do I use the data stored in the cookie to log a user in? I'm guessing I don't want to go to the DB on every page load. And it will still require me to create a database object to see if the credentials in the cookie are ok. Is this the right way to this?
Once again, apologies for the newbie question!
UPDATE:
Yes, I do understand the difference between $_SESSION variables and a cookies. I also have session_start() at the top of every page (right after <php with no blank lines). $_SESSION("UserID") just remains blank.
Here's the code from the top of the page:
<?php
session_start();
if(!isset($_SESSION['initiated'])) {
session_regenerate_id();
$_SESSION['initiated'] = true;
}
Thanks for the help.
First off, there is an important difference between a session and a cookie. When you use the $_SESSION[".."] you are creating a session (which lives on the server, compared to a cookie which lives on the client), even though the browser uses a cookie to keep track of the session id. To create a cookie you would use the setcookie() method.
That said, I would recommend you to read through this article which is a step-by-step guide on how to create a secure login script, with persistence using a cookie for a "Remember me"-feature. Describe how to do it in detail would be to extensive for an SO answer im afraid.
Side note:
To be able to write to the session, you might have to call session_start(); prior to getting or setting a session variable using $_SESSION[".."].
Did you write a custom session handler that has your session-files stored in the db? I guess you don't.
If you want to use $_SESSION you have to also do session_start(). When using PHP sessions the cookie to identify the user will be set for you. You will also get session files created in your /tmp directory. That's the location your variables and anything you assign to $_SESSION will be stored.
Unless you define a custom session handler, that will manage the location of the session files, you won't need to query your database. Just save the users credentials in $_SESSION.
See this Tutorial on how to use PHP sessions.
PS: You access arrays like this: $_SESSION["UserID"], not with ().
you might want want to look at this article in which i have already discussed about various types of session hijacking and how you could avoid it.
session security in php
I`m going to implement a login feature to a website that I`m building ... I have two options while implementing, cookies and sessions.
Which will be better to use for each of these scenarios?
Remember Me.
Sign In/Login.
Shall I use sessions or cookies? or both?
If both, how can I create, store and load cookies? And how can I add the cookies to the session?
Session is used with login and this is the standard way to do the login thing.
Remember cookies and session both are different.
Of course session uses cookie to identify the session of current user.
and the remember me works on cookies save the userid and pass in cookies and implement remember me.
You can create cookies with php function setcookie() and for your second question session create a cookie by itself and maintain the session id as cookie value so don't need to handle session cookie by yourself.
For the case that you mentioned, you certainly have to use both.
Session is needed for server side verification while cookies are needed storing information in the client side.
Here are the links for Sessions and Cookies from PHP Site.