#!/bin/bash
##
# update and upgrade server
##
apt-get update
apt-get upgrade -y
apt-get dist-upgrade -y
apt-get autoremove -y

##
# create new user to admin server via ssh
##
USER="YourName"
PASSWORD="GiveMeYourPassBaby"
HOME="/home/$USER"
HOSTNAME="www.example.com"
SSH_KEY="PasteYourSSHKeyHere"
###############################################################################
# HOW TO GENERATE SSH_KEY === >
# on your local machine open terminal and type:
# ssh-keygen -t rsa -b 4096 -C "your_email@example.com"
# Now appears the text: generating public/private rsa key pair.
# Enter a file in which to save the key (/Users/you/.ssh/id_rsa): [Press enter]
# Enter passphrase (empty for no passphrase): [Type a passphrase]
# Enter same passphrase again: [Type passphrase again]
# cat ~/.ssh/id_rsa.pub copy and paste in SSH_KEY !!!
###############################################################################
# quietly add a user without password
adduser --system --quiet --shell=/bin/bash --home=$HOME --gecos '$USER' --group $USER
usermod -aG sudo $USER
# set password
echo "$USER:$PASSWORD" | chpasswd

##
# create authorized_keys access on the server
##
# create authorized_keys access on the server
mkdir -p $HOME/.ssh
chmod 700 $HOME/.ssh
echo "$SSH_KEY" >> $HOME/.ssh/authorized_keys
chown $USER:$USER $HOME/.ssh*
chown $USER:$USER $HOME/.ssh/authorized_keys
chmod 600 $HOME/.ssh/authorized_keys
rm /etc/ssh/sshd_config
cat <<EOF > /etc/ssh/sshd_config
# Package generated configuration file
# See the sshd_config(5) manpage for details

# What ports, IPs and protocols we listen for
Port 22
# Use these options to restrict which interfaces/protocols sshd will bind to
#ListenAddress ::
#ListenAddress 0.0.0.0
Protocol 2
# HostKeys for protocol version 2
HostKey /etc/ssh/ssh_host_rsa_key
HostKey /etc/ssh/ssh_host_dsa_key
HostKey /etc/ssh/ssh_host_ecdsa_key
HostKey /etc/ssh/ssh_host_ed25519_key
#Privilege Separation is turned on for security
UsePrivilegeSeparation yes

# Lifetime and size of ephemeral version 1 server key
KeyRegenerationInterval 3600
ServerKeyBits 1024

# Logging
SyslogFacility AUTH
LogLevel INFO

# Authentication:
LoginGraceTime 120
PermitRootLogin no
StrictModes yes

RSAAuthentication yes
PubkeyAuthentication yes
AuthorizedKeysFile	%h/.ssh/authorized_keys

# Don't read the user's ~/.rhosts and ~/.shosts files
IgnoreRhosts yes
# For this to work you will also need host keys in /etc/ssh_known_hosts
RhostsRSAAuthentication no
# similar for protocol version 2
HostbasedAuthentication no
# Uncomment if you don't trust ~/.ssh/known_hosts for RhostsRSAAuthentication
#IgnoreUserKnownHosts yes

# To enable empty passwords, change to yes (NOT RECOMMENDED)
PermitEmptyPasswords no

# Change to yes to enable challenge-response passwords (beware issues with
# some PAM modules and threads)
ChallengeResponseAuthentication no

# Change to no to disable tunnelled clear text passwords
PasswordAuthentication no

# Kerberos options
#KerberosAuthentication no
#KerberosGetAFSToken no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes

# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCredentials yes

X11Forwarding yes
X11DisplayOffset 10
PrintMotd no
PrintLastLog yes
TCPKeepAlive yes
#UseLogin no

#MaxStartups 10:30:60
#Banner /etc/issue.net

# Allow client to pass locale environment variables
AcceptEnv LANG LC_*

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

# Set this to 'yes' to enable PAM authentication, account processing,
# and session processing. If this is enabled, PAM authentication will
# be allowed through the ChallengeResponseAuthentication and
# PasswordAuthentication.  Depending on your PAM configuration,
# PAM authentication via ChallengeResponseAuthentication may bypass
# the setting of "PermitRootLogin without-password".
# If you just want the PAM account and session checks to run without
# PAM authentication, then enable this but set PasswordAuthentication
# and ChallengeResponseAuthentication to 'no'.
UsePAM yes
EOF
systemctl reload sshd
hostname $HOSTNAME