diff --git a/sources/tech/20140723 How to configure chroot SFTP in Linux.md b/sources/tech/20140723 How to configure chroot SFTP in Linux.md new file mode 100644 index 0000000000..8c6f80e601 --- /dev/null +++ b/sources/tech/20140723 How to configure chroot SFTP in Linux.md @@ -0,0 +1,89 @@ +How to configure chroot SFTP in Linux +================================================================================ +There are **some scenario** where system admin wants only few users should be allowed to transfer files to Linux boxes not ssh. We can achieve this by setting up **SFTP** in chroot environment. + +### Background of SFTP & chroot : ### + +**SFTP** stands for **SSH File Transfer protocol or Secure File Transfer Protocol**. SFTP provides file access, file transfer, and file management functionalities over any reliable data stream. When we configure SFTP in chroot environment , then only allowed users will be limited to their **home directory** , or we can say allowed users will be in jail like environment where they can’t even change their directory. + +In article we will configure **Chroot SFTP in RHEL 6.X** & **CentOS 6.X**. We have one user ‘**Jack**’ , this users will be allowed to transfer files on linux box but no ssh access. + +### Step:1 Create a group ### + + [root@localhost ~]# groupadd sftp_users + +### Step:2 Assign the secondary group(sftp_users) to the user. ### + +If the users doesn’t exist on system , use below command : + + [root@localhost ~]# useradd -G sftp_users -s /sbin/nologin jack + [root@localhost ~]# passwd jack + +For **already existing users** , use below usermod command : + + [root@localhost ~]# usermod –G sftp_users -s /sbin/nologin jack + +**Note** : if you want to change the **default home directory** of users , then use ‘**-d**’ option in useradd and usermod command and set the **correct permissions**. + +### Step:3 Now edit the config file “/etc/ssh/sshd_config” ### + + # vi /etc/ssh/sshd_config + #comment out the below line and add a line like below + #Subsystem sftp /usr/libexec/openssh/sftp-server + Subsystem sftp internal-sftp + + # add Below lines at the end of file + Match Group sftp_users + X11Forwarding no + AllowTcpForwarding no + ChrootDirectory %h + ForceCommand internal-sftp + +#### Where : #### + +- **Match Group sftp_users** – This indicates that the following lines will be matched only for users who belong to group sftp_users +- **ChrootDirectory %h** – This is the path(default user's home directory) that will be used for chroot after the user is authenticated. So, for Jack, this will be /home/jack. +- **ForceCommand internal-sftp** – This forces the execution of the internal-sftp and ignores any command that are mentioned in the ~/.ssh/rc file. + +Restart the ssh service + + # service sshd restart + +### Step:4 Set the Permissions : ### + + [root@localhost ~]# chmod 755 /home/jack + [root@localhost ~]# chown root /home/jack + [root@localhost ~]# chgrp -R sftp_users /home/jack + +If You want that jack user should be allowed to upload files , then create a upload folder with the below permissions , + + [root@localhost jack]# mkdir /home/jack/upload + [root@localhost jack]# chown jack. /home/jack upload/ + +### Step:5 Now try to access the system & do testing ### + +Try to access the system via ssh + +![](http://www.linuxtechi.com/wp-content/uploads/2014/07/ssh-try.png) + +As You can see below jack user is logged in via SFTP and can't change the directory becuase of chroot environment. + +![](http://www.linuxtechi.com/wp-content/uploads/2014/07/sftp-login.png) + +Now do the **uploading and downloading** testing as shown below: + +![](http://www.linuxtechi.com/wp-content/uploads/2014/07/sftp-upload-download.png) + +As we can see above , both uploading & downloading working fine for jack user. + +-------------------------------------------------------------------------------- + +via: http://www.linuxtechi.com/configure-chroot-sftp-in-linux/ + +原文作者:[Pradeep Kumar][a] + +译者:[译者ID](https://github.com/译者ID) 校对:[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译,[Linux中国](http://linux.cn/) 荣誉推出 + +[a]:http://www.linuxtechi.com/author/pradeep/ \ No newline at end of file