Ssh – Restricted SFTP-only access to a single directory using OpenSSH

Yes, it is possible. You have to use the "ChrootDirectory" directive. ( man sshd_config ). If you want to chroot only a specific user and your ssh version has sftp builtin:

Match user the_user_you_want_to_chroot
         ChrootDirectory /home/whatever/%u
         ForceCommand internal-sftp

( Be sure to check the manpage as it can be different )

Starting with version 4.9 OpenSSH (not available in centos 5.x but ChrootDirectory feature was backported) has an internal-sftp subsystem:

Subsystem sftp internal-sftp

And then block other uses:

Match group sftponly
     ChrootDirectory /upload/%u
     X11Forwarding no
     AllowTcpForwarding no
     AllowAgentForwarding no
     ForceCommand internal-sftp

Add your users to the sftponly group. The chroot directory must be owned by root, and cannot be group-writeable, so create a subdirectory for each user, e.g. uploads or home/$username that's owned by the appropriate user (if you match their home directory, it will be the default working directory when connecting). I'd also set /bin/false as the user's shell.

As an example, users can then upload single files with:

sftp username@hostname <<< 'put filename.ext uploads/'

(scp will hopefully soon be modified to use sftp so this will become easier)