Tag Archives: sftp

SFTP allow user to login via SFTP

Linux,

If we are just allowing both on AllowUsers in file /etc/ssh/sshd_config, new users won’t be allowed to access the server.

So!, lets edit it a add the new user. Find AllowUser line and add it there.

sudo nano /etc/ssh/sshd_config

This should look something like

#PermitRootLogin without-password
PermitRootLogin no
StrictModes yes
AllowUsers bofh newuser

Save and Exit!
Restart SSH

service ssh restart

Now the user!

addgroup --system filetransf

usermod -G filetransf username
chown root:root /home/username
chmod 755 /home/username

cd /home/username
chown username:filetransf *

 

Hooray!

 

fatal: no matching mac found

Linux, ,

One of my clients was trying to connect, for the first time, on his brand new server..
Somehow he wasn’t able to connect….

He showed me the following *log/report*…

Status:    Waiting to retry...
Status:    Connecting to 37.XX.XX.XX...
Response:  fzSftp started
Command:   open "[email protected]" 22
Error:     Server unexpectedly closed network connection
Error:     Could not connect to server

and this is the auth.log on the server…

fatal: no matching mac found: client hmac-sha1,hmac-sha1-96,hmac-md5 server [email protected],hmac-sha2-256-$

Solution?
Update the SFTP client – in this case filezilla -.

Readings?
https://forum.filezilla-project.org/viewtopic.php?t=31738
https://en.wikibooks.org/wiki/OpenSSH/Logging

SFTP/SSH Write failed: Broken pipe

Linux, , ,

I was trying to access via SFTP and SSH to a host, and I was getting some strange errors…
yesterday it was okay….

ssh [email protected]
[email protected]'s password:
Write failed: Broken pipe

I’v sshed with other user and changed to a root user.
Had to read the auth.log file to figure out what was going on.

root@sd-11111:/home/mike# tail -f /var/log/auth.log

So… this is what I got.

May 28 13:45:31 sd-11111 sshd[1676]: Accepted password for mike from 84.91.4.220 port 59004 ssh2
May 28 13:45:31 sd-11111 sshd[1676]: pam_unix(sshd:session): session opened for user mike by (uid=0)
May 28 13:45:31 sd-11111 systemd-logind[447]: Removed session 4.
May 28 13:45:31 sd-11111 systemd-logind[447]: New session 5 of user mike.
May 28 13:45:32 sd-11111 sshd[1694]: fatal: bad ownership or modes for chroot directory "/home/mike"
May 28 13:45:32 sd-11111 sshd[1676]: pam_unix(sshd:session): session closed for user mike

The solution was to do the following…

root@sd-11111:/home# sudo chown root:root /home/mike/
root@sd-11111:/home# sudo chmod 755 /home/mike/

 

 

SFTP – Restrain/Lock/Jail the user to their home

Linux, ,
Create the user and their home
cd /home
mkdir username
useradd -d /home/username -M -N -g users username
sudo chown root:root /home/username
sudo chmod 755 /home/username
Edit /etc/ssh/sshd_config
nano /etc/ssh/sshd_config

Search for “lib/openssh/sftp-server” and make it like

#Subsystem sftp /usr/lib/openssh/sftp-server
Subsystem sftp internal-sftp

Add the following lines bellow it…

Match User username
    ChrootDirectory /home/username
    ForceCommand internal-sftp
Restart SSH
service ssh restart

More readings
http://www.techrepublic.com/blog/linux-and-open-source/chroot-users-with-openssh-an-easier-way-to-confine-users-to-their-home-directories/
http://superuser.com/questions/370953/how-to-not-allow-user-outside-of-home-directory-with-sftp