I am trying to backup all the files on our server using some SSH commands via PHP and I have a script working to some extent.
The problem is that only some of the folders actually contain any files but the folder structure seems to be correct though.
This is the script I am using:
<?php
$output = `cd /
ls -al
tar -cf /home/b/a/backup/web/public_html/archive.tar home/*`;
echo "<pre>$output</pre>";
?>
I cant even view the files via SSH commands, an example of this is the test account. If I use the following command I am unable to view the website files.
<?php
$output = `cd /home/t/e/test/
ls -alRh`;
echo "<pre>$output</pre>";
?>
But if I use the same commands on the a different account I am able to see and download of the website files.
Is this a permission problem or am I missing something in my script?
Thanks
ls -l / | grep home
the output will be like this:
lrwxr-xr-x 1 root wheel 8 Mar 30 14:13 home -> usr/home
In my case, the owner is root, and the root user its primary group is wheel, so now we add www-data user to wheel group so he can list files in there:
usermod -a -G wheel www-data
You can download some files because they located in directory owned by www-data user, and when you can't, www-data has no permission in that.
I think it permission problem, try to give apache user(or what you set it) permission to read /home/* directory's.
To find the user name that used by apache service run this:
For linux:
egrep -iw --color=auto 'user|group' /etc/httpd/conf/httpd.conf
For FreeBSD:
egrep -iw --color=auto '^user|^group' /usr/local/etc/apache22/httpd.conf
My guess is that PHP is running in a chroot.
If you just want to execute a backup, consider doing it in a different language. Especially if it is just a sequence of UNIX commands, write a shell script. Perhaps more details on what this script will be used for and who is providing and maintaining your hosting will be useful.
Related
I want to allow users to execute a bash script that contains sensitive data. Thus, I don't want them to have reading permissions. A 'direct' solution seems to be impossible, but I may have found a workaround in the expect man page:
Create the Expect script (that contains the secret data) as usual.
Make its permissions be 750 (-rwxr-x---) and owned by a trusted group,
i.e., a group which is allowed to read it. If necessary, create a new
group for this purpose. Next, create a /bin/sh script with permissions
2751 (-rwxr-s--x) owned by the same group as before.
I've tried to replicate this as follows:
In a folder, I have two scripts:
script.sh:
#!/bin/sh
echo "targetscript echo"
runscript.sh:
#!/bin/sh
echo "runscript echo"
groups
./script.sh
I gave them the rights as suggested in the man page:
groupadd scriptrunner
chown {myusername}:scriptrunner runscript.sh
chmod 2751 runscript.sh
chown root:scriptrunner script.sh
chmod 750 script.sh
The output of ls -l appears to be alright:
-rwxr-s--x. 1 {myusername} scriptrunner 51 Aug 25 13:04 runscript.sh
-rwxr-x---. 1 root scriptrunner 35 Aug 25 13:01 script.sh
However, when I run ./runscript.sh without root, I get the following error:
runscript echo
{myusername} wheel
./runscript.sh: line 4: ./script.sh: Permission denied
I don't know what went wrong. Can anyone help me?
I'll go back to the root problem as I think it's easier to solve without the expect hack.
So, what you need is having the execute permission on your script but not the reading permission. That is only possible for binaries (i.e. not interpreted scripts)- see details here https://unix.stackexchange.com/questions/34202/can-a-script-be-executable-but-not-readable
So maybe you'll be better off by first compiling your bash script into a binary (with shc - see here https://unix.stackexchange.com/questions/64762/how-to-convert-a-shell-script-into-a-binary-executable) and then set the execute only permission on the binary. Afterwards your users should be able to execute (but not read) the binary.
I'm having trouble to run a bash file using PHP.
PHP File :
chdir('/var/www/PATH/inc/bash/');
exec('./status.sh argument, $output);
Bash File :
#!/bin/bash
echo 'test' >> /var/www/PATH/inc/bashOutput/test.txt
PHP File (ls -al handler.func.php) :
-rw-r--r-- 1 root root 461 Jul 5 11:35 handler.func.php
Bash File (ls -al status.sh) :
-rwxr-xr-x 1 root root 255 Jul 5 11:39 status.sh
Script is working using through root with SSH.
I'm not a pro on Linux.
But I think it's a problem come with the file owner.
But I have already done some damages in the past with "chown" so If it is indead the problem I would prefer some guidance from more experienced people.
Thanks for you help,
Konorr.
Script is working using through root with SSH. There is the problem. When a PHP script run via a web request it usually runs as the user www-data. In anycase <?php exec('./status.sh argument, $output);?> in a security hole. Most server admins would have this disabled.
Your other option is to put sudo in your exec function exec('sudo bash /var/www/PATH/inc/bash/status.sh'). Along with running the script with an absolute path bash /var/www/PATH/inc/bash/status.sh
Why can't you run a cron on your script?
Thanks for you answer but unfortunatly it didn't worked for me.
I search a litle more about file owners.
I did few changes
I made in these change :
chown -R www-data:www-data /var/www/PATH
usermod -a -G www-data user
chgrp -R www-data /var/www/PATH
chmod 2750 /var/www/PATH
chmod 2750 /var/www/PATH/inc/bash
It wasn't yet working till I removed the sudo from the EXEC function.
So I don't know from which point my problem was already fixed.
I followed this article : www-data permissions?
Thanks for you time and in the hope it can help someone else.
I'm trying to display my PIs temperatures in a website that I can access anywhere at any time.
So far I've been able to get the CPU and GPU temps working. However my HDD temp won't show in the browser. It works fine in terminal.
Here is a pic:
As you'll notice I didn't have the GPU temp showing either, however this was fixed by using the following command:
sudo usermod -G video www-data
I haven't been successful in getting this to work for smartmoxntools, though.
Does anyone know how to make it work?
Also, is it safe to have these in an external website? Can hackers inject php code to run shell commands using it?
in order to run some root privileged command in website, you need to put www-data in your /etc/sudoers to allow the www-data to run as root for the command, here is the line you need in /etc/sudoers:
www-data ALL=(root) NOPASSWD: /usr/sbin/smartctl
When executing under your web server, your script will probably have a different PATH configured, so it will run differently from how it runs in the Terminal.
Try putting the full path to smartctl in your script, e.g.
sudo /usr/local/bin/smartctl -A -d sat /dev/sda | awk '/^194/ {print $10}'
I want to execute a Bash script present on the system from a PHP script. I have two scripts present on the system. One of them is a PHP script called client.php present at /var/www/html and the other is a Bash script called testscript present at /home/testuser.
My client.php script looks like
<?php
$message=shell_exec("/home/testuser/testscript 2>&1");
print_r($message);
?>
My testscript looks like
#!/bin/bash
echo "Testscript run succesful"
When i do the following on terminal
php client.php
I get the following output on terminal
Testscript run successful
But when i open the page at
http://serverdomain/client.php
I get the following output
sh: /home/testuser/testscript: Permission denied
I get this error even after I did chmod +x testscript.
How do I get it to work from the browser? Please help.
I would have a directory somewhere called scripts under the WWW folder so that it's not reachable from the web but is reachable by PHP.
e.g. /var/www/scripts/testscript
Make sure the user/group for your testscript is the same as your webfiles. For instance if your client.php is owned by apache:apache, change the bash script to the same user/group using chown. You can find out what your client.php and web files are owned by doing ls -al.
Then run
<?php
$message=shell_exec("/var/www/scripts/testscript 2>&1");
print_r($message);
?>
EDIT:
If you really want to run a file as root from a webserver you can try this binary wrapper below. Check out this solution for the same thing you want to do.
Execute root commands via PHP
Without really knowing the complexity of the setup, I like the sudo route.
First, you must configure sudo to permit your webserver to sudo run the given command as root. Then, you need to have the script that the webserver shell_exec's(testscript) run the command with sudo.
For A Debian box with Apache and sudo:
Configure sudo:
As root, run the following to edit a new/dedicated configuration file for sudo:
visudo -f /etc/sudoers.d/Webserver
(or whatever you want to call your file in /etc/sudoers.d/)
Add the following to the file:
www-data ALL = (root) NOPASSWD: <executable_file_path>
where <executable_file_path> is the command that you need to be able to run as root with the full path in its name(say /bin/chown for the chown executable). If the executable will be run with the same arguments every time, you can add its arguments right after the executable file's name to further restrict its use.
For example, say we always want to copy the same file in the /root/ directory, we would write the following:
www-data ALL = (root) NOPASSWD: /bin/cp /root/test1 /root/test2
Modify the script(testscript):
Edit your script such that sudo appears before the command that requires root privileges(say sudo /bin/chown ... or sudo /bin/cp /root/test1 /root/test2). Make sure that the arguments specified in the sudo configuration file exactly match the arguments used with the executable in this file.
So, for our example above, we would have the following in the script:
sudo /bin/cp /root/test1 /root/test2
If you are still getting permission denied, the script file and it's parent directories' permissions may not allow the webserver to execute the script itself.
Thus, you need to move the script to a more appropriate directory and/or change the script and parent directory's permissions to allow execution by www-data(user or group), which is beyond the scope of this tutorial.
Keep in mind:
When configuring sudo, the objective is to permit the command in it's most restricted form. For example, instead of permitting the general use of the cp command, you only allow the cp command if the arguments are, say, /root/test1 /root/test2. This means that cp's arguments(and cp's functionality cannot be altered).
I was struggling with this exact issue for three days. I had set permissions on the script to 755. I had been calling my script as follows.
<?php
$outcome = shell_exec('/tmp/clearUp.sh');
echo $outcome;
?>
My script was as follows.
#!bin/bash
find . -maxdepth 1 -name "search*.csv" -mmin +0 -exec rm {} \;
I was getting no output or feedback. The change I made to get the script to run was to add a cd to tmp inside the script:
#!bin/bash
cd /tmp;
find . -maxdepth 1 -name "search*.csv" -mmin +0 -exec rm {} \;
This was more by luck than judgement but it is now working perfectly. I hope this helps.
It's a simple problem. When you are running from terminal, you are running the php file from terminal as a privileged user. When you go to the php from your web browser, the php script is being run as the web server user which does not have permissions to execute files in your home directory. In Ubuntu, the www-data user is the apache web server user. If you're on ubuntu you would have to do the following:
chown yourusername:www-data /home/testuser/testscript
chmod g+x /home/testuser/testscript
what the above does is transfers user ownership of the file to you, and gives the webserver group ownership of it. the next command gives the group executable permission to the file. Now the next time you go ahead and do it from the browser, it should work.
I want to execute a Bash script present on the system from a PHP script. I have two scripts present on the system. One of them is a PHP script called client.php present at /var/www/html and the other is a Bash script called testscript present at /home/testuser.
My client.php script looks like
<?php
$message=shell_exec("/home/testuser/testscript 2>&1");
print_r($message);
?>
My testscript looks like
#!/bin/bash
echo "Testscript run succesful"
When i do the following on terminal
php client.php
I get the following output on terminal
Testscript run successful
But when i open the page at
http://serverdomain/client.php
I get the following output
sh: /home/testuser/testscript: Permission denied
I get this error even after I did chmod +x testscript.
How do I get it to work from the browser? Please help.
I would have a directory somewhere called scripts under the WWW folder so that it's not reachable from the web but is reachable by PHP.
e.g. /var/www/scripts/testscript
Make sure the user/group for your testscript is the same as your webfiles. For instance if your client.php is owned by apache:apache, change the bash script to the same user/group using chown. You can find out what your client.php and web files are owned by doing ls -al.
Then run
<?php
$message=shell_exec("/var/www/scripts/testscript 2>&1");
print_r($message);
?>
EDIT:
If you really want to run a file as root from a webserver you can try this binary wrapper below. Check out this solution for the same thing you want to do.
Execute root commands via PHP
Without really knowing the complexity of the setup, I like the sudo route.
First, you must configure sudo to permit your webserver to sudo run the given command as root. Then, you need to have the script that the webserver shell_exec's(testscript) run the command with sudo.
For A Debian box with Apache and sudo:
Configure sudo:
As root, run the following to edit a new/dedicated configuration file for sudo:
visudo -f /etc/sudoers.d/Webserver
(or whatever you want to call your file in /etc/sudoers.d/)
Add the following to the file:
www-data ALL = (root) NOPASSWD: <executable_file_path>
where <executable_file_path> is the command that you need to be able to run as root with the full path in its name(say /bin/chown for the chown executable). If the executable will be run with the same arguments every time, you can add its arguments right after the executable file's name to further restrict its use.
For example, say we always want to copy the same file in the /root/ directory, we would write the following:
www-data ALL = (root) NOPASSWD: /bin/cp /root/test1 /root/test2
Modify the script(testscript):
Edit your script such that sudo appears before the command that requires root privileges(say sudo /bin/chown ... or sudo /bin/cp /root/test1 /root/test2). Make sure that the arguments specified in the sudo configuration file exactly match the arguments used with the executable in this file.
So, for our example above, we would have the following in the script:
sudo /bin/cp /root/test1 /root/test2
If you are still getting permission denied, the script file and it's parent directories' permissions may not allow the webserver to execute the script itself.
Thus, you need to move the script to a more appropriate directory and/or change the script and parent directory's permissions to allow execution by www-data(user or group), which is beyond the scope of this tutorial.
Keep in mind:
When configuring sudo, the objective is to permit the command in it's most restricted form. For example, instead of permitting the general use of the cp command, you only allow the cp command if the arguments are, say, /root/test1 /root/test2. This means that cp's arguments(and cp's functionality cannot be altered).
I was struggling with this exact issue for three days. I had set permissions on the script to 755. I had been calling my script as follows.
<?php
$outcome = shell_exec('/tmp/clearUp.sh');
echo $outcome;
?>
My script was as follows.
#!bin/bash
find . -maxdepth 1 -name "search*.csv" -mmin +0 -exec rm {} \;
I was getting no output or feedback. The change I made to get the script to run was to add a cd to tmp inside the script:
#!bin/bash
cd /tmp;
find . -maxdepth 1 -name "search*.csv" -mmin +0 -exec rm {} \;
This was more by luck than judgement but it is now working perfectly. I hope this helps.
It's a simple problem. When you are running from terminal, you are running the php file from terminal as a privileged user. When you go to the php from your web browser, the php script is being run as the web server user which does not have permissions to execute files in your home directory. In Ubuntu, the www-data user is the apache web server user. If you're on ubuntu you would have to do the following:
chown yourusername:www-data /home/testuser/testscript
chmod g+x /home/testuser/testscript
what the above does is transfers user ownership of the file to you, and gives the webserver group ownership of it. the next command gives the group executable permission to the file. Now the next time you go ahead and do it from the browser, it should work.