openvpn-easyrsa Cookbook

Installs openvpn and easy-rsa and uses the latter to configure the ca, server, dh and all the other bits, so you can start the server right away.

Using easy-rsa you can also add user-certificates fairly easy - ./easy-rsa build-client-full client1.

The layout and deployment also offers an integration with the Certificate/User management tool https://github.com/flant/ovpn-admin

If you upgrade from the sous-chef openvpn cookbook or consider so, read the CHANGELOG.md - we have massive changes and you will need to start your pki from scratch - there is no other upgrade path.

Easy-rsa

You can use easy-rsa after the deployment to run any renewals or easy-rsa specific commands in

cd /etc/openvpn/easy-rsa
./easy-rsa show-ca
./easy-rsa gen-crl

# create a client certificate
./easy-rsa build-client-full client1

Ovpn-Admin

The layout deployed by this cookbook and the compliance against easy-rsa offers a sleek integration with https://github.com/flant/ovpn-admin - a GUI to maintain, add and revoke user certificates (and download the client config).

You need to configure this variables to be compatible out of the box

EASYRSA_PATH=/etc/openvpn/easy-rsa/pki
OVPN_INDEX_PATH=/etc/openvpn/easy-rsa/pki/index.txt

Attributes

These attributes are set by the cookbook by default.

node['openvpn']['client_cn'] - The client's Common Name used with the openvpn::client recipe (essentially a standalone recipe) for the client certificate and key.
node['openvpn']['type'] - Valid values are 'client' (currently a work in progress), 'server' or 'server-bridge'. Default is 'server' and it will create a routed IP tunnel, and use the 'tun' device. 'server-bridge' will create an ethernet bridge and requires a tap0 device bridged with the ethernet interface, and is beyond the scope of this cookbook.
node['openvpn']['subnet'] - Used for server mode to configure a VPN subnet to draw client addresses. Default is 10.8.0.0, which is what the sample OpenVPN config package uses.
node['openvpn']['netmask'] - Netmask for the subnet, default is 255.255.0.0.
node['openvpn']['gateway'] - FQDN for the VPN gateway server. Default is node['fqdn'].
node['openvpn']['push_routes'] - Array of routes to to push to clients (as push statements) in the server.conf, e.g. '192.168.0.0 255.255.255.0'. Default is empty.
node['openvpn']['push_options'] - Array of options to push to clients in the server.conf, e.g. [["dhcp-option DNS", ["8.8.8.8"]]]. Default is empty.
node['openvpn']['configure_default_server'] - Boolean. Set this to false if you want to create all of your "conf" files with the LWRP.
node['openvpn']['git_package'] - Boolean. Whether to use the openvpn-git package (Arch Linux only, default false).
node['openvpn']['server_verification'] - Server certificate verification directive, can be anything mentioned in official doc. By default nil.
node['openvpn']['config']['local'] - IP to listen on, defaults to node['ipaddress']
node['openvpn']['config']['proto'] - Valid values are 'udp' or 'tcp', defaults to 'udp'.
node['openvpn']['config']['port'] - Port to listen on, defaults to '1194'.
node['openvpn']['config']['log'] - Server log file. Default /var/log/openvpn.log
node['openvpn']['config']['script-security'] - Script Security setting to use in server config. Default is 1. The "up" script will not be included in the configuration if this is 0 or 1. Set it to 2 to use the "up" script.

The following attributes are used to populate the easy-rsa vars file. Defaults are the same as the vars file that ships with OpenVPN.

node['openvpn']['key']['ca_expire'] - In how many days should the root CA key expire - CA_EXPIRE.
node['openvpn']['key']['expire'] - In how many days should certificates expire - KEY_EXPIRE.
node['openvpn']['key"]['size'] - Default key size, set to 2048 if paranoid but will slow down TLS negotiation performance - KEY_SIZE.

The following are for the default values for fields place in the certificate from the vars file. Do not leave these blank.

node['openvpn']['key']['country'] - KEY_COUNTRY
node['openvpn']['key']['province'] - KEY_PROVINCE
node['openvpn']['key']['city'] - KEY_CITY
node['openvpn']['key']['org'] - KEY_ORG
node['openvpn']['key']['email'] - KEY_EMAIL

The following lets you specify the message digest used for generating certificates by OpenVPN

node['openvpn']['key']['message_digest'] - Default is sha256 for a high-level of security.

The CRL will be generated, and refreshed automatically, allowing you to revoke certificates

node['openvpn']['key']['crl_expire'] - In how many days should the CRL expire? Will be refreshed after half of this time

Configure a shared tls key - will be located at /etc/openvpn/easy-rsa/pki/ta.key

node['openvpn']['tls']['generate_tls_shared_key'] - set to true to configure a shared tls key (tls-auth)

Recipes

`openvpn::default`

Installs the OpenVPN package only.

`openvpn::install`

Installs the OpenVPN package only.

`openvpn::server`

Installs and configures OpenVPN as a server. Installs easy-rsa and configures all needed certificates for the server.

`openvpn::service`

Manages the OpenVPN system service (there is no need to use this recipe directly in your run_list).

Usage

Create a role for the OpenVPN server. See above for attributes that can be entered here.

name "openvpn"
description "The server that runs OpenVPN"
run_list("recipe[openvpn::server]")
override_attributes(
  "openvpn" => {
    "gateway" => "vpn.example.com",
    "subnet" => "10.8.0.0",
    "netmask" => "255.255.0.0",
    "key" => {
      "country" => "US",
      "province" => "CA",
      "city" => "SanFrancisco",
      "org" => "Fort-Funston",
      "email" => "me@example.com"
    }
  }
)

Note: If you are using a Red Hat EL distribution, the EPEL repository is automatically enabled by Chef's recipe[yum::epel] to install the openvpn package.

To push routes to clients, add node['openvpn']['push_routes] as an array attribute, e.g. if the internal network is 192.168.100.0/24:

override_attributes(
  "openvpn" => {
    "push_routes" => [
      "192.168.100.0 255.255.255.0"
    ]
  }
)

To push other options to clients, use the node['openvpn']['push_options'] attribute and set an array of hashes or strings. For example:

override_attributes(
  "openvpn" => {
    "push_options" => {
      "dhcp-option" => [
        "DOMAIN domain.local",
        "DOMAIN-SEARCH domain.local"
      ],
      "string-option" => "string value"
    }
  }
)

This will render a config file that looks like:

push "dhcp-option DOMAIN domain.local"
push "dhcp-option DOMAIN-SEARCH domain.local"
push "string-option string value"

This cookbook also provides an 'up' script that runs when OpenVPN is started. This script is for setting up firewall rules and kernel networking parameters as needed for your environment. Modify to suit your needs, upload the cookbook and re-run chef on the openvpn server. For example, you'll probably want to enable IP forwarding (sample Linux setting is commented out). The attribute node['openvpn']["script_security"] must be set to 2 or higher to use this otherwise openvpn server startup will fail.

#S Resources

openvpn_config

Given a hash of config options it writes out individual openvpn config files.

If you don't want to use the default "server.conf" from the default recipe, set node['openvpn']["configure_default_server"] to false, then use this resource to configure things as you like.

Example

.pem files should be provided before (e.g.: cookbook_file)

openvpn_conf 'myvpn' do
  config({
    'client' => '',
    'dev' => 'tun',
    'proto' => 'tcp',
    'remote' => '1.2.3.4 443',
    'cipher' => 'AES-128-CBC',
    'tls-cipher' => 'DHE-RSA-AES256-SHA',
    'auth' => 'SHA1',
    'nobind' => '',
    'resolv-retry' => 'infinite',
    'persist-key' => '',
    'persist-tun' => '',
    'ca' => "/etc/openvpn/myvpn/ca.pem",
    'cert' => "/etc/openvpn/myvpn/cert.pem",
    'key' => "/etc/openvpn/myvpn/key.pem",
    'comp-lzo' => '',
    'verb' => false,
    'auth-user-pass' => "/etc/openvpn/myvpn/login.conf",
  })
end

# for systemd based systems
service 'openvpn@myvpn' do
  action [:start, :enable]
end

Customizing Server Configuration

To further customize the server configuration, there are two templates that can be modified in this cookbook.

templates/default/server.conf.erb
templates/default/server.up.sh.erb

The first is the OpenVPN server configuration file. Modify to suit your needs for more advanced features of OpenVPN. The second is an up script run when OpenVPN starts. This is where you can add firewall rules, enable IP forwarding and other OS network settings required for OpenVPN. Attributes in the cookbook are provided as defaults, you can add more via the openvpn role if you need them.

SSL Certificates

Some of the easy-rsa tools are copied to /etc/openvpn/easy-rsa to provide the minimum to generate the certificates using the default and users recipes. We provide a Rakefile to make it easier to generate client certificate sets if you're not using the data bags above. To generate new client certificates you will need rake installed (either as a gem or a package), then run:

cd /etc/openvpn/easy-rsa
source ./vars
easyrsa show-ca

Credits

The work here is based on https://github.com/sous-chefs/openvpn See all the old contributors, bakers and sponsors there.

EugenMayer / openvpn