I'm trying to avoid 777 permissions for a directory that handles file uploads on a Linux server. PHP/Apache must be able to write to this particular directory, but I don't want to make it world-writable.
What're the best-practices for this?
I am not too familiar with the CLI, so my attempts to solve this using chgrp and chown have not yielded any results.
Thanks!
ACLs if supported. You could do something as simple as setfacl -R -m u:www-data:rwx,d:u:www-data:rwx /path/to/directory to allow apache to write to that specific directory (and all later created directories as well)
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I am trying to open/read and copy/delete files on the disk in a Linux-system, using a PHP-script. The files remain in Billy's directory (/home/billy/uploads), all sent by FTP. They have basic rights (rw on the user only) and are owned by, according to 'ls -lr', by billy:billy.
Trying to fopen or copy the file does not work, neither chown or chmod using PHP.
How can I make the 'PHP-user', www-data, to do what I want? What is need to be done? I set the owner of the containing directory, 'uploads', to be www-data, but no luck there.
A quick but dirty way would be to loosen the safety on "billy's" home files. You still can make other files non readable to others, but you have to keep it in mind.
First, (using user billy, sudo rights or root) make /home/billy/ accessible to others, but only this: remove any rights (read-write-execute) from anyone else:
chmod og-rwx /home/billy/*
chmod 755 /home/billy/
second, make uploads writable and accessible to others:
chmod 777 /home/billy/uploads/
if you want existing content to be visible you might need something like
chmod -R og+r /home/billy/uploads/*
So I have a PHP file located in /var/www/html/test.php and I have it run the code shell_exec('touch /home/pi/Desktop/test_file')
However, the webpage displays fine but when I check the apache log files, I always get permission denied. I understand that apache is running as www-data user and my main user pi probably have some permission clash (I'm new to this stuff).
I tried many options I found on-line, the most promising was here, which suggested I run the commands:
sudo chown -R pi:www-data /home/pi/Desktop
sudo chmod -R g+s /home/pi/Desktop
...but I still get permission denied. Can anyone please suggest what permissions I may need to still configure? I want to ensure security, but at the same time need my PHP file to be able to create new files. I used the Desktop as an example directory, but really I don't care which directory, I just need a directory. I tried touching a file within /var/www/html, but that was permission denied as well. Thanks!
if your apache process is running as www-data, and the file ownership is pi:www-data, you probably need to run this chmod:
sudo chmod -R g+w /home/pi/Dekstop
First, setting the group as www-data won't matter if the files are not group writable. Mode 755 will ensure apache can read the files, but the www-data user would still not be able to write.
Secondly, using "g+w" adds group write without messing with any of the other bits. [644 becomes 664, and 755 becomes 775)]. This way you can safely adjust permissions recursively, without making files executable that shouldn't be.
Incidentally, sudo chmod g+s ... is probably not what you want. That will instead set the sgid bit, and not the group write bit.
First of all, why the heck are you using shell_exec to create a file? PHP has it's own touch() function that will do that for you. You can also create files just by opening a nonexistent file using certain modes (ie, fopen("myfile", "w"))
Using exec to create your files is surely messing with your permissions.
You need to find out which user PHP is running as and chown to that user. You can find that out by running get_current_user().
Then you need to change the permissions with chmod. There's an example in the comments so I won't repeat it. Good luck. Stop using shell_exec.
Forgive me for my simple question but how do you make it writable?
I read it it needs to be change to for example: for timthumbs or http://shiftingpixel.com/2008/03/03/smart-image-resizer/
"Make your imagecache directory is writable by the web server (usually chmod 775)"
So I just call the function or what?
Usually, it's a bad idea to chmod 755 directories without some serious forethought. On your webserver, there will be a user that the web server software runs as, usually something like www-data or apache. You can chown -R apache /path/to/your/cache/dir and that way PHP can write to that directory.
EDIT: To clarify, these are commands you would run from a shell on your webserver, such as via SSH. They are not PHP functions. Your web host should have more information about how you can get shell access.
chmod is a command line unix/linux command. You'd access it via an SSH console or you should be able to modify with whatever mechanism you're using to upload the files with (SSH, SFTP, FTP, etc)
Use the chmod command to change folder permissions
chmod 775 foldername
or if you are using FTP, you can use filezilla (right click on folder, and type 775 in the permissions)
I'm trying to create XML sitemaps for my website from my PHP application. The idea is to either create a new file or overwrite an existing file. When I call fopen, I get the following error:
[function.fopen]: failed to open stream: Permission denied
I'm trying to write to the webroot and its permissions are: 755. This means that the owner has write permission, right? What do I need to do to make my script be able to write to this folder? 777 would be a bad thing, right? Can I run my script as owner somehow?
Thanks.
Yep, as you've said, using 777 could be huge mistake. The webserver doesn't run with the same user as you use to create files and folders.
You have some options:
Run the sitemap creation as a cronjob, using an user with rights to write there, other than the apache user.
Put the sitemap in another directory, and the set up a 302 Redirect or a symlink. In this case, if you have a security issue that let's someone to write your sitemap.xml, at least they'll not be able to create another file with a more dangerous extensions (like PHP, which may result in a site intrusion).
Make a rewrite rule to redirect any hit to sitemap.xml, to a php script that outputs the appropriate XML.
Good luck!
I'm a beginner and I had this problem as well. I am using Ubuntu linux w/ php and apache
Write a php script w/ the following: <?php exec('whoami'); ?> and run it on your server. This tells you who the current user of the script is
SSH to your server.
Make a group that has read and write access to the files you need.
Make group have read, write, and execute on folders you need.
Make the current user you found in the first step, part of the group that has access to the files you need.
Restart Apache: sudo apachectl restart
main commands you need are:
groupadd: Create a new group
usermod: add your user to a new group
chgrp: changes files / folders to group you specify
chmod: changes permissions on the files / folders you specify.
All the commands you need are here: http://www.yolinux.com/TUTORIALS/LinuxTutorialManagingGroups.html
If you have ACL enabled on the webroot partition just grant the web server username full rights
setfacl -m u:apache:rwx /var/www/html
Replace apache with the web server username and /var/www/html with your webroot location.
had the same problem
Looks like apache is running as nobody in the nobody group
so if you do a
useradd -G nobody youruser
chown -R youruser:nobody .
Then change the permission to 0775
chmod -R 0775 .
or you may add nobody to your usergroup
useradd -G nobody yourgroup
this be a better solution
Does it work with group write enabled (i.e. 775)?
Check your group permissions for the directory the file is in. As long as your PHP user (usually www-data) is part of that group, and it's the only user, you should be fine with 775 (or even 774).
Like Pascal said!
just find your apache user
<?php exec'whoami'; ?>
and then
useradd -G username username2
chown -R username:username2 .
chmod -R 0775 .
And its done!
Thank you Pascal!
777 is pretty normal, because PHP does not run as you, it runs as a PHP user, Apache, etc. The fact is, your webhost should have a higher set of permissions that prevents other users from writing/deleting your files.
I want my PHP software to be able to auto update. For this to work, I need PHP to be able to write into files both existing and non-existing (create). Will it always work if I just CHMOD the target files to be 0777 and then write into it? Or does the PHP/Apache/wtvr process need to be the owner of the file?
Sometimes when people upload using an FTP account, the owner might be different from the PHP process, is this a problem?
Edit: I'm building a PHP application, I can't know on which configurations the app will run on, and I can't modify any server related settings. I can do what PHP can do, like chown(), chmod().
I have one server where, when files are uploaded through FTP, the ownership of the file changes to the ftp user which has caused a few permission problems in the past.
We use groups to get round this
For example, you could create a usergroup for accessing the files and add apache plus each of your ftp users to the group:
usermod -a -G appUpdaters www
usermod -a -G appUpdaters ftp1
usermod -a -G appUpdaters ftp2
etc...
Then you can chown the file/folders to a user + group and chmod to 775
chown www.appUpdaters foldername
chmod 775 foldername
That way if the ownership changes to ftp1.appUpdaters or ftp2.appUpdaters, the other users can still write to the file.
Like I say, I don't seem to need this on all the servers I use so I guess whether you do or not depends on your server config. If you do decide to use groups tho, I find this link comes in handy sometimes
http://www.cyberciti.biz/faq/howto-linux-add-user-to-group/
Make the folder that you want to upload into owned by your www server. Then your php script will be able to write into that folder if it's chmodded 755.
# chown www somefolder
# chmod 755 !$
(Don't make other stuff in your web files owned by www).