Enable SSL VPN on FortiGate and Connect It With FortiClient (Free Lab) – 51 Security

1 VPN -> SSL-VPN Settings

Most settings are default. But you will need to add interface on the listen list. Ideally, change Listen on Port to a different port from 443. In this example, I am using 4443. 

note: Default tunnel user range is only 10 ip addresses. If you have more than 10, you might want to increase it by customizing a larger range there.

2 Autentication/Portal mapping

Change All Other Users/Groups to have tunnel-access to Portal.

You can have an admin group / users to have full-access to Portal. 

3 SSL VPN Client Address Range

By default, it is automatically assigned by FortiGate.

In the above screenshot, it uses automatically assign range: 10.212.134.200 -10.212.134.210

The range can be customized for larger numbers based on your usage. 

Use Fortinet_Factory Server Certificate

 To make lab as simple as we can, we are gonna use Fortinet_Factory cert.

It is possible to directly create your own certificate using Let’s Encrypt. 

You might get this cert warning message when you access the portal by using default cert since it wont be able verified:

Policies and Users

1 SSL VPN > LAN

This firewall rule is to allow SSL VPN network to access LAN (Internal) networks.

You will need to choose incoming interface, outgoing interface, source (including users), destination, and services. Others, you can keep it as default. 

You can use NAT with outgoing interface address, which is your FortiGate LAN interface IP, or you can completely disable NAT. 

Logging is also can be enabled for all sessions. 

Here is how the SSL VPN Firewall Policy rule looks like:

2 Remote Users and Group

Create a Remote Users group. Add a couple of remote users into this group. 

3 Check Forwarded Log since we enabled all sessions logging

1 Send SSL-VPN Configuration

2 Download FortiClient

https://www.fortinet.com/support/product-downloads

3 Install FortiClient

Double click the downloaded installation file “FortiClientVPNOnlineInstaller.exe” and follow installation wizard to complete installation.

4 Configure FortiClient to connect to remote FortiGate SSLVPN Gateway 

Make sure put right public ip address and SSLVPN Port. 

Enable SSL VPN Web Portal

Note:https://community.fortinet.com/t5/FortiGate/Technical-Tip-SSL-VPN-web-mode-showing-403-Forbidden-error/ta-p/297377

FortiGate # show vpn ssl web portal 
config vpn ssl web portal
    edit "full-access"
        set tunnel-mode enable
        set ipv6-tunnel-mode enable
        set web-mode enable
        set ip-pools "SSLVPN_TUNNEL_ADDR1"
        set ipv6-pools "SSLVPN_TUNNEL_IPv6_ADDR1"
    next
    edit "web-access"
        set web-mode enable
    next
    edit "tunnel-access"
        set tunnel-mode enable
        set ipv6-tunnel-mode enable
        set ip-pools "SSLVPN_TUNNEL_ADDR1"
        set ipv6-pools "SSLVPN_TUNNEL_IPv6_ADDR1"
    next
end

FortiGate # 

C:\Users\WDAGUtilityAccount>ping 10.0.3.4

Pinging 10.0.3.4 with 32 bytes of data:
Reply from 10.0.3.4: bytes=32 time=39ms TTL=63
Reply from 10.0.3.4: bytes=32 time=47ms TTL=63
Reply from 10.0.3.4: bytes=32 time=38ms TTL=63
Reply from 10.0.3.4: bytes=32 time=38ms TTL=63

Ping statistics for 10.0.3.4:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 38ms, Maximum = 47ms, Average = 40ms

C:\Users\WDAGUtilityAccount>tracert 10.0.3.4

Tracing route to 10.0.3.4 over a maximum of 30 hops

  1    33 ms    36 ms    37 ms  10.212.134.200
  2    34 ms    35 ms    34 ms  10.0.3.4

Trace complete.

Note: The routing address override settings will be pushed to Forticlient machine’s routing table.

You can check them using “route print” command from CMD window once you connected your Forticlient to Fortigate. 

2. Add one route into your FortiGate routing tables. 

The gateway will be the Azure LAN network’s default gateway .1 ip address.

3. Firewall Rule in the FortiGate policy enabled NAT on LAN interface.

That is important in some cases to make your traffic passing through firewall. 

Password expiration policy for SSL VPN local user

Note: https://community.fortinet.com/t5/FortiGate/Technical-Tip-Password-expiration-policy-for-SSL-VPN-local-user/ta-p/192723

To configure SSL VPN users to change their password in the local user database before it expires

The password policy is used to configure the password renewal frequency (every 2 days for instance) and the warning that normally occurs the day before the expiration date. Password policy can be applied to any local user password.

The password policy cannot be applied to a user group or a local remote user such as LDAP/RADIUS/TACACS+.

In FortiOS 7.0, users are warned as per warn-days set and they have to renew their password before it get expire, which is based on the expire-days mentioned in the password policy. The user cannot renew the password and need to contact the FortiGate administrator for assistance. 

In FortiOS 6.2, users are warned one day before the expiry date of the password and they have one day to renew it. When the password is expired, the user cannot renew the password and need to contact the FortiGate administrator for assistance.

In FortiOS 6.0/5.6, users are warned one day before the expiry date of the password. Users can still renew the password even after the password has expired.

Configure and assign the password policy using the CLI

The following commands are used to configure a password policy that includes an expiration date and a warning time. 

#config user password-policy
    edit “pwpolicy1”          <- password policy name.
        set expire-days 5     <- password expiry.
        set warn-days 3       <- warning notification for password going to be expire soon.
        set expired-password-renewal disable  <- if enable this option is, after the password expires, still end user can renew the password, with no need to depend upon FortiGate Administrator. 
    next

end

Assign the password policy to the newly created user.

#config user local

    edit “sslvpnuser1”     <- local username.
        set type password
        set passwd-policy “pwpolicy1”    <- applying password policy.
        set passwd-time 2021-11-26 22:46:15    <- the default start time for the password, this is the time when the user was created.
        set passwd  xyz   <- password.
    next
end

Once the user is reached warn-days, the user will get the below prompt, while connecting to SSL VPN by entering old username and password. It will redirect to enter a new password for the same.

Once a user changes his password,  ‘passwd-time‘ will get changed again. 

# config user local

    edit “sslvpnuser1”

     set type password
     set passwd-policy “pwpolicy1”
     set passwd-time 2021-11-30 23:34:30  <- passwd-time has been changed.
     set passwd ENC +sddai212=

    next

end

Note that, currently, the Password renewal for local users when using the Dial IPSec VPN is not supported.

As to the password complexity policy to apply to SSL VPN Users, here are some documents we can reference to: