SCP Upload / Download only access for Linux

SCP-Upload-Download-only-access-Linux

## Server Setup
# SSH commands for creating user and download upload directories

groupadd backupusers
useradd -g backupusers -s /sbin/nologin backupuser
mkdir -p /mnt/SystemAdmin/BackupStorage/{upload,download}
chown backupuser:backupusers /mnt/SystemAdmin/BackupStorage/{upload,download}
chown root:root /mnt/SystemAdmin/BackupStorage
chmod 755 /mnt/SystemAdmin/BackupStorage

echo "
Match User backupuser
	AuthorizedKeysFile /mnt/SystemAdmin/AuthorizedKeys/BackupUser
	ForceCommand internal-sftp
	PasswordAuthentication no
	ChrootDirectory /mnt/SystemAdmin/BackupStorage
	PermitTunnel no
	AllowAgentForwarding no
	AllowTcpForwarding no
	X11Forwarding no
" >> /etc/ssh/sshd_config

# Paste your generated SSH key below
mkdir -p /mnt/SystemAdmin/AuthorizedKeys
cat > /mnt/SystemAdmin/AuthorizedKeys/BackupUser << EOF
ssh-ed25519 yourlongsshkeygoeshere BackupUser
EOF

chmod 0600 /mnt/SystemAdmin/AuthorizedKeys/BackupUser
chown -R backupuser:backupusers /mnt/SystemAdmin/AuthorizedKeys/BackupUser
systemctl restart sshd

## Client Setup
# Now the SCP command to download from remote server
## Downloading individual files
scp -i /pathtosshkey/id_ed25519_BackupUser backupuser@remoteserver.com:/download/remotefile.zip /home/username/Downloads

## Full directory download
scp -i /pathtosshkey/id_ed25519_BackupUser -r backupuser@remoteserver.com:/download/ /home/username/Downloads