OpenConnect

OpenConnect-compatible server feature is available from this release. Openconnect VPN supports SSL connection and offers full network access. SSL VPN network extension connects the end-user system to the corporate network with access controls based only on network layer information, such as destination IP address and port number. So, it provides safe communication for all types of device traffic across public networks and private networks, also encrypts the traffic with SSL protocol.

The remote user will use the openconnect client to connect to the router and will receive an IP address from a VPN pool, allowing full access to the network.

Configuration

SSL Certificates

We need to generate the certificate which authenticates users who attempt to access the network resource through the SSL VPN tunnels. The following commands will create a self signed certificates and will be stored in configuration:

run generate pki ca install <CA name>
run generate pki certificate sign <CA name> install <Server name>

We can also create the certificates using Cerbort which is an easy-to-use client that fetches a certificate from Let’s Encrypt an open certificate authority launched by the EFF, Mozilla, and others and deploys it to a web server.

sudo certbot certonly --standalone --preferred-challenges http -d <domain name>

Server Configuration

set vpn openconnect authentication local-users username <user> password <pass>
set vpn openconnect authentication mode <local password|radius>
set vpn openconnect network-settings client-ip-settings subnet <subnet>
set vpn openconnect network-settings name-server <address>
set vpn openconnect network-settings name-server <address>
set vpn openconnect ssl ca-certificate <pki-ca-name>
set vpn openconnect ssl certificate <pki-cert-name>
set vpn openconnect ssl passphrase <pki-password>

2FA OTP support

Instead of password only authentication, 2FA password authentication + OTP key can be used. Alternatively, OTP authentication only, without a password, can be used. To do this, an OTP configuration must be added to the configuration above:

set vpn openconnect authentication mode local <password-otp|otp>
set vpn openconnect authentication local-users username <user> otp <key>
set vpn openconnect authentication local-users username <user> interval <interval (optional)>
set vpn openconnect authentication local-users username <user> otp-length <otp-length (optional)>
set vpn openconnect authentication local-users username <user> token-type <token-type (optional)>

For generating an OTP key in VyOS, you can use the CLI command (operational mode):

generate openconnect username <user> otp-key hotp-time

Verification

[email protected]:~$ sh openconnect-server sessions
interface    username    ip             remote IP    RX       TX         state      uptime
-----------  ----------  -------------  -----------  -------  ---------  ---------  --------
sslvpn0      tst         172.20.20.198  192.168.6.1  0 bytes  152 bytes  connected  3s

Note

It is compatible with Cisco (R) AnyConnect (R) clients.

Example

SSL Certificates generation

Follow the instructions to generate CA cert (in configuration mode):

[email protected]# run generate pki ca install ca-ocserv
Enter private key type: [rsa, dsa, ec] (Default: rsa)
Enter private key bits: (Default: 2048)
Enter country code: (Default: GB) US
Enter state: (Default: Some-State) Delaware
Enter locality: (Default: Some-City) Mycity
Enter organization name: (Default: VyOS) MyORG
Enter common name: (Default: vyos.io) oc-ca
Enter how many days certificate will be valid: (Default: 1825) 3650
Note: If you plan to use the generated key on this router, do not encrypt the private key.
Do you want to encrypt the private key with a passphrase? [y/N] N
2 value(s) installed. Use "compare" to see the pending changes, and "commit" to apply.
[edit]

Follow the instructions to generate server cert (in configuration mode):

[email protected]# run generate pki certificate sign ca-ocserv install srv-ocserv
Do you already have a certificate request? [y/N] N
Enter private key type: [rsa, dsa, ec] (Default: rsa)
Enter private key bits: (Default: 2048)
Enter country code: (Default: GB) US
Enter state: (Default: Some-State) Delaware
Enter locality: (Default: Some-City) Mycity
Enter organization name: (Default: VyOS) MyORG
Enter common name: (Default: vyos.io) oc-srv
Do you want to configure Subject Alternative Names? [y/N] N
Enter how many days certificate will be valid: (Default: 365) 1830
Enter certificate type: (client, server) (Default: server)
Note: If you plan to use the generated key on this router, do not encrypt the private key.
Do you want to encrypt the private key with a passphrase? [y/N] N
2 value(s) installed. Use "compare" to see the pending changes, and "commit" to apply.
[edit]

Each of the install command should be applied to the configuration and commited before using under the openconnect configuration:

[email protected]# commit
[edit]
[email protected]# save
Saving configuration to '/config/config.boot'...
Done
[edit]

Openconnect Configuration

Simple setup with one user added and password authentication:

set vpn openconnect authentication local-users username tst password 'OC_bad_Secret'
set vpn openconnect authentication mode local password
set vpn openconnect network-settings client-ip-settings subnet '172.20.20.0/24'
set vpn openconnect network-settings name-server '10.1.1.1'
set vpn openconnect network-settings name-server '10.1.1.2'
set vpn openconnect ssl ca-certificate 'ca-ocserv'
set vpn openconnect ssl certificate 'srv-ocserv'

Adding a 2FA with an OTP-key

First the OTP keys must be generated and sent to the user and to the configuration:

[email protected]:~$ generate openconnect username tst otp-key hotp-time
# You can share it with the user, he just needs to scan the QR in his OTP app
# username:  tst
# OTP KEY:  5PA4SGYTQSGOBO3H3EQSSNCUNZAYAPH2
# OTP URL:  otpauth://totp/[email protected]?secret=5PA4SGYTQSGOBO3H3EQSSNCUNZAYAPH2&digits=6&period=30
█████████████████████████████████████████
█████████████████████████████████████████
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████ █   █ █▀ █▄▄▀▀▀▄█  ▄▄▀▄ █ █   █ ████
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████ ▀▀ ▀ ▄█▄ ▀ ▀▄ ▄█▀ ▄█ ▄▀▀▄██    █████
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████ █ ▀█▄▄█▄ ▀ ▄▄▀▀  ▀ █▄█▀████ █▀ ▀████
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████ █   █ █ ▀▄██▄▄▀█▄▀▄██▄▀  ▄  ▀██▀████
████ █▄▄▄█ █ ██▀▄▄  ▀▄▄▀█▀ ▀█ ▄▀█ ▀██████
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# To add this OTP key to configuration, run the following commands:
set vpn openconnect authentication local-users username tst otp key 'ebc1c91b13848ce0bb67d9212934546e41803cfa'

Next it is necessary to configure 2FA for OpenConnect:

set vpn openconnect authentication mode local password-otp
set vpn openconnect authentication local-users username tst otp key 'ebc1c91b13848ce0bb67d9212934546e41803cfa'

Now when connecting the user will first be asked for the password and then the OTP key.

Warning

When using Time-based one-time password (TOTP) (OTP HOTP-time), be sure that the time on the server and the OTP token generator are synchronized by NTP

To display the configured OTP user settings, use the command:

show openconnect-server user <username> otp <full|key-b32|key-hex|qrcode|uri>