OpenVPN config without HMAC

client.conf

client
dev tun
proto tcp
remote 1.2.3.4 443

ca ca.crt
cert client1.crt
key client1.key

resolv-retry infinite
nobind
persist-key
persist-tun
auth SHA256
cipher AES-256-CBC
ns-cert-type server
comp-lzo
verb 3

server-setup

#### Ubuntu 14.04 Server
# Update and upgrade system
apt-get update
apt-get upgrade
# Install packages
apt-get install openvpn easy-rsa

## Create OpenVPN server keys
# Copy scripts
cp -r /usr/share/easy-rsa /etc/openvpn/easy-rsa
cd /etc/openvpn/easy-rsa/
source vars
./clean-all
# Create CA. Just press Enter multiple times
./build-ca
# Create server certificate. Just pass all with Enter except last two requests.
# IMPORTANT! You need to answer "y" on "Sign the certificate?" and "1 out of 1 certificate requests certified, commit?"
./build-key-server server
# Create DH file
./build-dh
# Copy keys
cp ./keys/server.crt ./keys/server.key ./keys/ca.crt ./keys/dh2048.pem /etc/openvpn/

## Configure server
# Copy contents of this server.conf above
# Close nano with Ctrl+O
nano /etc/openvpn/server.conf
# Run service
service openvpn restart

## Create client certificate
# You can pass all with Enter except last two.
# IMPORTANT! You need to answer "y" on "Sign the certificate?" and "1 out of 1 certificate requests certified, commit?"
./build-key client1
# Create directory for easy download from /root
mkdir /root/ovpn/
# Copy files needed for client
cp ./keys/ca.crt ./keys/client1.crt ./keys/client1.key /root/ovpn/

## Enable NAT forwarding if disabled
# first of all enable it in current session
sysctl -w net.ipv4.ip_forward=1
# Now uncomment "net.ipv4.ip_forward=1" in sysctl config so this applied after each restart
nano +28 /etc/sysctl.conf
# Check status of forwarding and make sure it's return "1"


## Now you configure NAT for OpenVPN subnet
# Run following commands to apply forwarding rules before restart
iptables -A FORWARD -s 10.9.0.0/24 -j ACCEPT
iptables -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -t nat -A POSTROUTING -s 10.9.0.0/24 -o eth0 -j MASQUERADE
# Now copy exactly same 3 lines into /etc/rc.local so rule will be set on each startup.
# Lines have to be before "exit 0" line
nano +13 /etc/rc.local

server.conf

port 443
proto tcp
dev tun
fast-io
auth SHA256
cipher AES-256-CBC

ca ca.crt
cert server.crt
key server.key
dh dh2048.pem

server 10.9.0.0 255.255.255.0
ifconfig-pool-persist ipp.txt
push "route 10.9.0.0 255.255.255.0"
push "redirect-gateway def1 bypass-dhcp"
push "dhcp-option DNS 8.8.8.8"
push "dhcp-option DNS 8.8.6.6"
keepalive 10 120
comp-lzo
user nobody
group nogroup
persist-key
persist-tun
status openvpn-status.log
verb 3