php exec() rsync ssh to remote server not working - php

I am trying to rsync file from local to remote server.
When i do this on console it works:
rsync -avzhe ssh /var/www/folder1/file5
root#192.168.56.74:/var/www/folder2
but when i do this on my php and run the php script, it doesn't work:
$rysncCommand = "rsync -avzhe ssh /var/www/folder1/file5 root#192.168.56.74:/var/www/folder2";
shell_exec($rysncCommand);
There is no error shown, so i can't really tell what is the error. Is there something wrong with my php script?

First, you need to check if you need to be a root or (sudo user) for running rsync.
If yes then exec() command will only work if it is run by same user on php-cli (not on browser by Apache user). i.e. Which user you are loggined into shell for run rsync.
If it is root or any elavated permission user with sudo permission then, This rsync command may not be available to apache/www-data user which is working when php script run from browser.
So You try to make a normal user and login through it, Then try rsync if you are successful then it may be interesting to see what are other problems can be, But if you getting access/permission denied then obviously you can not run this script at-least on browser.
Besides this One more thing permission may not be directly related to rsync command itself but with folder /etc/test/ which is owned by root user in normal scenario.
For more details you can check this Stack Overflow Link .

Related

Git pull “permission denied” when using shell_exec in PHP

I'm trying to make a hook on bitbucket, that executes a php file, and this file executes the pull command:
shell_exec('/usr/local/cpanel/3rdparty/bin/git pull');
The pull command works fine on the SSH console, but the PHP returns the error:
Permission denied (publickey). fatal: Could not read from remote
repository.
Please make sure you have the correct access rights and the repository
exists.
The command --version shows the path to git is right, whoiami returns the same user on both, so I don't know if it is a permission issue.
What can be going wrong?
Edit: An additional issue: the alias I added for git don't work on PHP, only the full path as above. Via terminal it works just fine. Maybe it's the same reason why the key don't work in php.
Edit 2: $PATH is different on both.
When you run this command within a PHP script you are not running the command as yourself:
shell_exec('/usr/local/cpanel/3rdparty/bin/git pull');
The reason it works from the terminal console is you run the command as yourself from the console. But on a web server, you are not the user running the command. Remember: When you run PHP on a web server, it is a an Apache module. Meaning the web server user—which could be www-data, root or even apache on some systems—is running the PHP script which then runs the shell_exec command.
So it would never work as you have it setup. Perhaps you can kludge something together that would allow a key-pair to be used by the web server for these purposes, but that seems like a security risk waiting to happen.

Executing commands in php as root user in arch linux

i am using arch linux. i want to execute the php file which changes the ip of the system. i did
ifconfig eth0 192.168.163.137
in the terminal and it works fine. the same i tried doing with
shell_exec('ifconfig eth0 192.168.163.137');
in a php file and tried opening the page from a remotely located web browser from another pc connected via router. teh page displays nothing and the code also doesnt execute. i guess its the problem with the user executing it.apache is executing it. so i want it to be run by the root.can anyone please guide me to the execution of my code. i even installed sudo and just put
shell_exec('sudo ifconfig......');
it too doesnt execute...please help...thanku..:)
Sudo normally requires an interactive shell to enter your password. That's obviously not going to happen in a PHP script. If you're sure you know what you're doing and you've got your security issues covered, try allowing the Apache user to run sudo without a password, but only for certain commands.
For example, adding the following line in your sudoers file will allow Apache to run sudo without a password, only for the ifconfig command.
apache ALL=NOPASSWD: /sbin/ifconfig
Adjust the path and add any arguments to suit your needs.
Caution:
There might still be complications due to the way PHP calls shell commands.
Remember that it's very risky to allow the web server to run commands as root!
Probably a better alternative:
Write a shell script with the suid bit to make it run as root no matter who calls it.
shell_exec
This function is disabled when PHP is running in safe mode.
Documentation : http://php.net/manual/en/function.shell-exec.php
So, maybe try tweaking your php.ini file?
Write the commands to a queue and have cron pick them up, validate them (only allow known good requests), and run them, then mark that queue complete with the date and result.
Your end-user can then click/wait for update using ajax.

Executing a command line using php shell_exec() for initiating a camera on the server

I am using opencv for initiating the camera on my arch linux. Its getting initiated and works well when I actually do it from the command line on the server itself.
I want to initialize it using php. I tried doing it using shell_exec from PHP.
My PHP file looks like:
<?php
$output=shell_exec('LD_LIBRARY_PATH=usr/local/lib ./a.out 0 2>&1 1>/dev/null');
echo $output;
?>
It gives this output:
ERROR: capture is NULL
I am running this through my windows web browser as a client and the opencv and the related files are on the server that is my arch linux.
I want to start the camera and capture images when I run this php file from the windows web browser, but when executed it throws the error as mentioned.
While this may work when you are SSHed into your server. The webserver user is most likely different than the user you login as. Popular user ids/groups that webservers run as on Linux machines are http, www-data, nobody, and others.
From this point you have two options.
You can make sure the script you are trying to run from PHP (and all of it's children, if any) is able to be run by the webserver user.
You can modify your /etc/sudoers file which gives the webserver user access to elevate permissions for that script only. (NOTE: This potentially opens up security holes so be careful).
To find out what user your webserver runs as execute this: ps aux
Take a look at the output and the first column in the output lists the user that that process is running at. Here's an excerpt of my webserver (nginx) on one of my boxes:
www-data 26852 0.0 0.0 29768 3840 ? S Jun04 0:50 nginx: worker process
You can see that nginx runs with the user www-data here. You can also execute the command with grep to help you find the process quicker. Grep will only show you those lines which match what you send to it. Here's an example: ps aux | grep nginx
Ok now that you know what user the webserver is running as, let's try giving that user access to the script. Let's say your script is foo and is located in /usr/local/bin. You would do the following commands:
chown www-data /usr/local/bin/foo
After changing ownership on the file try to rerun your command again from your PHP page and see if it works.
For completeness I also said you could give your webserver user sudo privileges to that file. To do that you would need to append the following line to the bottom of your /etc/sudoers file:
www-data ALL= NOPASSWD: /usr/local/bin/foo
Then your shell_exec command could switch to this:
shell_exec('sudo /usr/local/bin/foo');
Please keep in mind that doing this would allow your webserver user to run the script as root which is incredibly dangerous in a variety of situations. However, the camera may require elevated permissions to work. I'm not sure what the permissions requirements are on the camera setup you are trying to invoke.
Good luck. Hope this helps!

PHP shell_exec - using RSYNC as root without password

I'm trying to create a PHP web interface for a staging->production publishing script. The web interface is secure (intranet,passworded etc) so I am happy to for apache act as the root user to perform the rsync. There is no password for the root user, a keyfile is used for SSH access.
I have tried sudo-ing the rysnc command in the shell script...
sudo rsync --verbose --recursive --times --perms --links --delete /tmp/dir1/* /tmp/dir2/
And allowing apache to run rsync by adding the following to the sudoers file...
apache ALL=(ALL) NOPASSWD:/usr/bin/rsync
I am using PHP shell_exec to invoke the script...
$result = shell_exec('bash /tmp/syncscript.sh 2>&1');
I get the following error...
sorry, you must have a tty to run sudo
How can I setup so I can run the rsync command as though I were the root user?
Thanks!
You might want to try what i wrote in this post if you want to use SUDO from PHP. It solved all my problems and i have a similar setup to yours, i have a DEV server internally but i want it to do things that only root can...
How to use exec() in php in combination with ssh 'hostname' command?
Good luck
In the end went for a non-sudo approach to this problem. Used phpseclib to get a connection to the box as a user that could do what I needed (not apache). And then made sure that the dirs/files that were being targetted in the rsync operation were accessible to this user.
Seems simple now I look back on it.

svn update with php and ssl

I want to do SVN update easier - with calling PHP script.
I created PHP script:
$cmd = "svn update https://___/svn/website /var/www/html/website/ 2>&1";
exec($cmd, $out);
As the user running the script is apache (not root), I get some permission errors.
If I change the owner of every directory to apache (or chrown everything to 777) I have another problem. Because I use https protocol user apache should permanently accept certificate of the svn server. I tried to do "su - apache" and accept certificate but OS says that "apache" is not valid user. I also dont know how could I accept certificate with exec() function.
Any idea? How can I make svn update-ing easier?
Is the error telling you that the user isn't a valid svn user? If apache is the user running httpd, you should be able to su to it. This is the script I use:
/usr/bin/svn --config-dir=/home/user/.subversion --username=svnuser --password=svnpass update
once the password is saved you can remove it from the command. Again, make sure the user/pass above is a valid SVN user.
Lately I've actually migrated to using Hudson for svn updates as you can schedule it as well as run manually and do a bunch of other tasks, plus you can view the svn logs for each commit as well as any console errors.
Why not use php svn functions instead of (insecure) exec?
http://www.php.net/manual/en/function.svn-auth-set-parameter.php has good examples for authentification options.
Use getent apache on the shell. This will return the shell of apache. Most likely, it is /bin/nologin or /bin/false. Change this to /bin/bash. You'll also need to specify the home directory and create it on the file system.
UPDATE: getent apache will actually return the entry in the /etc/passwd file for the apache user. The last token in this string is the shell.

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