It might be required sometime to prevent a user or all users with a specific role from accessing the WordPress admin panel. It’s not tough. Let’s think that we want that all users with author role will not be able to access the admin panel. All you have to do is just add the following … Continue reading How to prevent someone or some role from accessing the WordPress admin panel
Rsync is one of the most popular tools to synchronize data between two computers, and used mostly in taking backups using this sync feature. It’s easy to use and only uploads the changed files when a sync is necessary, so it’s effective in saving bandwidth and time too. To run rsync, you need root or a properly privileged user which can access that specific path in the remote machine. And to setup this privilege, you can either use a should-never-be-used root account or an user chrooted using a jail shell. But if, by any chance, current machine is compromised then remote machine is compromised too. Because anyone can connect to your remote machine using those credentials from the current machine. To avoid plain text credentials (or the credentials written in a shell script), people usually use ssh keys to establish a connection between two machines. Still, your remote machine is unsecured if anything goes wrong in the current machine from where you’re taking the backup.
So a fullproof solution is to use ssh keys and properly chroot the remote user so that it can only access the backup files and nothing else. However, setting up a jailed shell is a not-for-everyone type task and takes time and experience to accomplish properly. So here is a quick work around that you can implement in your remote machine to prevent the connecting user from doing anything malicious but only tasks those are needed to perform the rsync backup. Let’s see how we can do that
Before continuing, let’s name our two machines. The one which should be backed up, lets name that Workstation. And the one which is storing the backups is BackupServer. Also for now, let’s assume that you are backing up complete “/var/www” folder in the WorkStation.
Step 1: Create SSH key in the BackupServer
Log into the BackupServer and run the following command in ssh terminal. But remember, if you already have a key in ~/.ssh/id_rsa.pub then IGNORE IGNORE IGNORE this step.
ssh-keygen -t rsa
It will prompt for a passphrase, REMEMBER to just hit the enter without typing anything.
Step 2: Display and Copy the SSH key from BackupServer
Run the following command to display the ssh public key in the terminal, and then copy it.
Continue reading “Automated Rsync – without compromising security”
Created a screencast to show how you can create phar files, most importantly personalized phar files to store some information inside it and protect it using user’s password. Those information is usable only when user providers a correct password. For packaging, I used http://box-project.org which is an excellent phar packager. I’ve also used two functions … Continue reading Create personalized phar files in PHP
Sometime, you may need to log in an user manually from code, instead of generic form based log in. To do it, you need to use Two Security component “UsernamePasswordToken” and “InteractiveLoginEvent”. We will also use another exception object “UsernameNotFoundException” if the user is not found. [sourcecode language=”php”] use Symfony\Component\Security\Core\Authentication\Token\UsernamePasswordToken; use Symfony\Component\Security\Http\Event\InteractiveLoginEvent; use Symfony\Component\Security\Core\Exception\UsernameNotFoundException; [/sourcecode] … Continue reading How to login a user programatically in Symfony2
Ok, Facebook Groups has a huge security flaw by which any group member can pretend to be anyone else in that group, and post in the group on behalf of that user. It is FATAL. I’ve reported to Facebook and I hope they should take immediate action for it. I had disclosed it in details … Continue reading Massive security flaw in Facebook and why should they fix it immediately before I take your girlfriend out to dinner tonight
Long story short, I was developing a Facebook page application which runs from inside a page tab. Such applications runs inside an iframe on Facebook Fanpage. Everything was going perfectly, until, we started checking it in IE!! The symptoms were simple, PHP Session is not working when user logs in. The application works perfectly in … Continue reading Story about Blue E, iFramed Web Application, Wastage of 6 hours, Missed Lunch and what not!