Solved
I figured out who the current user was using PHP and managed to set the new directories' owner to be the user the PHP scripts are executed from. However, this was still causing issues as some other commands (used to determine who the current user was) weren't working. This highlighted that the problem was that my PHP distribution was configured to be in safe mode.
I disabled safe mode and the commands provided by Ed Manet allowed me to add/edit/remove the files as desired, without the shortcut of just having everything be 777 permissions.
Thanks for the help!
Original Post
I have a web application that stores some data on the server. This involves creating and removing both directories and files (as well modifying existing files) in PHP. The main problem I'm having is do with the permissions required to perform such actions.
If I set existing files' permissions to 777, then the PHP script can edit them just fine (although I know this isn't an optimal solution as it's insecure). The script can also create and remove directories just fine (when they have 777 permissions at least), but no matter what I do I cannot get the script to create new files.
I've done some searching around and it appears that I need to elevate the PHP "user" to a user that has the required priviliges. However, when it comes to server configuration and permissions I'm essentially a beginner. How would I change to a different user to perform the required actions? Is it possible to do this mid-script and use PHP's fopen() and chmod() functions as normal? Or would I have to spawn an entirely new process using a shell command, somehow getting that external program executing with the correct privileges?
To summarise, I need a new of creating, modifying and deleting files/directories in a we b server using PHP, by assigning adequate permissions to the files and privileges to the PHP user. I am unsure on how to do this.
Thank you.
What I would do is change ownership of the folder that the PHP has to create files in to the account that runs the PHP process. Then you don't need to open up permissions so much.
So if this is a Linux system and the webserver is run by a user called "apache":
chown -R apache /path/to/the/files
Then change permissions to owner read/write
chmod -R 644 /path/to/the/files
Related
I am currently attempting to write a simple web page to store emails in a database. I am on a server which is not mine (but does run Apache), so I do not have root access, so I have opted to use SQLite3. The goal is to use PHP to INSERT into the database, however, I continue to encounter the issue with the database being owned by me and the PHP attempting to access using the user "apache" which leads to a "readonly" error. Since I am not root, I cannot chown the database file and even when I chmod 777, it has no effect. The conclusion I came to was to have the PHP script create the database itself (under the user apache) but now I do not have write access to the file. Is it okay for me to just allow apache to own the database or is there some better way to do this?
SQLite is a library, i.e., it's just a bunch of code that runs inside the web server process. This means that accesses to the database file behave just like any other file access from Apache.
The web server process needs to be able to access the file itself, and to create the journal rollback file in the same directory.
chmod 777 is a bad because every user on that machine can do anything to the database. It would be a better idea to have the database file and the directory belong to a group that has you and apache as members.
If the server's administrator will not create such a group, then you could have apache as the owner, and add a backdoor (sufficiently protected) to your web app to allow overwriting the database with a new file.
With a PHP application deployed on Elastic Beanstalk, EC2, I've been using git and eb to manage my environment instances and all files. I need to change the permissions on a file directory to make it writable but git doesn't take care of transferring directory permissions. What's the simplest/fastest way to get this done from a mac?
Filezilla takes a long time to configure. I can SSH into my EC2 instance but still not sure how to change the permissions for my directory.
Login via SSH and type next.
Change permissions:
sudo su - # log-in as superuser*
chmod 755 /path/to/your/directory
# If you just want to allow Apache to write in directory then set 666 permissions
**If you're an owner of directory, you don't need to log-in as superuser.*
Change the owner if you need:
sudo su -
chown user:group /path/to/directory
UPDATE:
Thanks to jamieb for the correction in comments. Really I've unswered to particular gtech's question:
how to change the permissions for my directory
But of course in my opinion it's better to give permissions to e.g. apache (or www-data) user to that directory which you want to write in, to avoid such problems.
You have to do this from within your application itself. In your case, it would probably make the most sense to throw a try/catch block around the write operation and if an exception is thrown, adjust the permissions using PHP's chmod() function.
FYI, there's a pretty good chance that you don't want to be doing this though. Persistent data needs to be stored either in your database or S3 (in the case of files). Storing data locally in each instance's filesystem is a good way to lose that data the next time you do a code deployment, an autoscale event happens, or your rebuilt the environment. It can also cause problems because you're never sure which instance serves each request due to the Elastic Load Balancer.
Is there a way to properly set folder permissions via PHP on a Windows filesystem, such as granting user A full access, and user B read-only on folder \\fileserver\shares\users\A\
I can't seem to find any PHP functions for Windows filesystems for PHP
Any ideas?
Despite using the Unix file permission syntax, PHP's chmod() function does work in Windows (I just tested it).
If your user A was the file owner and user B wasn't then it would be easy to grant one set of permissions to user A and different permissions to user B. You can set the owner of a file using the chown() function (again, Unix-like syntax, but works with Windows, subject to your PHP program having sufficient permissions to itself to make the change).
Hope that helps.
If you have the ability to call command-line processes, you could use SetACL (if you need very detailed control) otherwise, CACLS is built in.
When I download a file with curl through php I cannot seem to be able to delete it afterwards through ftp. I can delete it through the php script, but that's not exactly perfect. If the file isn't downloaded via curl, but still via php I can delete the file, it's just ones downloaded via curl that I cannot delete. When I try to run chown() through php on the file it gives me a permissions error. I've tested the same php script on multiple other servers and it works fine there, it's just this particular one it doesn't work on. Maybe it has something to do with php configuration and permissions but I'm not 100% on that.
Sounds like it is saved with the file owner being the user account of the web server. A non-privileged account can't chown to a different user, either, so that explains why chown fails... Try having PHP execute chmod 777 on the file before you delete it.
When you create a file it is usually owned by the Apache user (or whatever app server you use). The FTP user however is not the same one most of the time. You can fix this by adding the FTP user to the Apache group (or the other way around). Sometimes they already share a group (like on many plesk environments) so making files readable and writeable for that shared group may solve the issue.
How can you allow a PHP script to write to a file with high-security restrictions, such as only allowing a single user to write to it?
The difficulty seems to be that a PHP script is running as a low-permissions user (maybe apache, or www, or nobody?), and even if I chown apache the_writable_file, the directory it's in might not be writable for the low-level user. In general, what's the usual way that PHP can work with local files in a secure way?
Unfortunately, in shared hosts that use mod_php, there is no way to restrict access to secure files to your web app and login user.
The solution is to run your web app as your login user. When you do that, UNIX file permissions can correctly lock everyone else out. There are several ways to implement that, including SuExec, suPHP, or running PHP with FastCGI with mod_fcgid or mod_proxy_fcgid. FastCGI is my favorite way.
Another solution is to use a dedicated host or virtual private server.
Sure, chgrp apache the_writable_file and chmod g+w the_writable_file. After that, only your secure user and the apache user will be able to write to the file. Since the apache user is typically forbidden from logging in, you only have to worry about web users writing to your secure file using through the http daemon.
All the containing folders need to have execute permissions.
For example, if the file's in /foo/bar/the_writable_file, the directories "foo" and "bar" both need to have executable permission to access the_writable_file, even if they don't have read/write permission.