I successfully managed to create a guest-sftp-account on a friends raspbian. I have a folder shared, which is the new root for the user sftpguest. Here he only has read-rights. Inside this folder, there's a folder upload, where he's allowed to write files. Login is working through a modified /etc/ssh/sshd.conf.
But now, the "real users", e.g. user pi, which log in to the whole filesystem via ssh, cannot login via sftp anymore, which is essential, because he wants to mount the whole filesystem in his nautilus or use the full filesystem via Windows Filezilla.
How can I manage to provide both things?
/etc/ssh/sshd.conf: (only what differs to standard)
Subsystem sftp interal-sftp UsePAM yes Match User sftpguest ChrootDirectory /media/Daten/shared ForceCommand internal-sftp