Technical Tip: SAML SP for VPN authentication

[Shilpa1]

Description
When a FortiGate is configured as a service provider (SP), create an authentication profile that uses SAML for both firewall and SSL VPN web portal authentication is possible.
Once the firewall is authenticated, entering SAML credentials is not required for SSL VPN web portal authentication.

This article describes SAML SP for VPN authentication by configuring FortiGate as an SP and FortiAuthenticator as the IdP server.

Solution
The following example uses a FortiGate as an SP and FortiAuthenticator as the IdP server:

To configure firewall authentication.

Configure the FortiGate SP to be a SAML user.

# config user saml
    edit "fac-firewall"
        set entity-id "http://10.2.2.2:1000/saml/metadata/"
        set single-sign-on-url "https://10.2.2.2:1003/saml/login/"
        set single-logout-url "https://10.2.2.2:1003/saml/logout/"
        set idp-entity-id "http://172.18.58.93:443/saml-idp/bbbbbb/metadata/"
        set idp-single-sign-on-url "https://172.18.58.93:443/saml-idp/bbbbbb/login/"
        set idp-single-logout-url "https://172.18.58.93:443/saml-idp/bbbbbb/logout/"
        set idp-cert "REMOTE_Cert_3"
        set user-name "username"
        set group-name "group"
    next
end

Add the SAML user to the user group (optionally, you can configure group matching).

# config user group
    edit "saml_firewall"
        set member "fac-firewall"
# config match
    edit 1
    set server-name "fac-firewall"
    set group-name "user_group1"
next
end
next
end

Add the SAML user group to a firewall policy.

# config firewall policy
    edit 2
        set srcintf "port3"
        set dstintf "port1"
        set srcaddr "all"
        set dstaddr "pc4"
        set action accept
        set schedule "always"
        set service "ALL"
        set logtraffic all
        set fsso disable
        set groups "saml_firewall" "group_local"
        set users "first"
        set nat enable
    next
end

Configure the FortiAuthenticator IdP as needed.

Run HTTP/HTTPS authentication for a remote user.

The SAML login page appears.

To configure SSL VPN web portal authentication.

Configure the FortiGate SP to be a SAML user.

# config user saml
    edit "fac-sslvpn"
        set entity-id "https://10.2.2.2:10443/remote/saml/metadata/"
        set single-sign-on-url "https://10.2.2.2:10443/remote/saml/login/"
        set single-logout-url "https://10.2.2.2:10443/remote/saml/logout/"
        set idp-entity-id "http://172.18.58.93:443/saml-idp/ssssss/metadata/"
        set idp-single-sign-on-url "https://172.18.58.93:443/saml-idp/ssssss/login/"
        set idp-single-logout-url "https://172.18.58.93:443/saml-idp/ssssss/logout/"
        set idp-cert "REMOTE_Cert_3"
        set user-name "username"
    next
end

Add the SAML user to the user group (group matching may also be configured).

# config user group
    edit "saml_sslvpn"
        set member "fac-sslvpn"
    next
end

Configure SSL VPN.

# config vpn ssl settings
    set servercert "Fortinet_Factory"
    set tunnel-ip-pools "SSLVPN_TUNNEL_ADDR1"
    set tunnel-ipv6-pools "SSLVPN_TUNNEL_IPv6_ADDR1"
    set source-interface "port3"
    set source-address "all"
    set source-address6 "all"
    set default-portal "full-access"
# config authentication-rule
    edit 1
        set groups "saml_sslvpn"
        set portal "web-access"
    next
end
end

Add the SAML user group to a firewall policy.

# config firewall policy
    edit 8
        set srcintf "ssl.vdom1"
        set dstintf "port1"
        set srcaddr "all"
        set dstaddr "all"
        set action accept
        set schedule "always"
        set service "ALL"
        set groups "local" "saml_sslvpn"
        set nat enable
    next
end

Configure the FortiAuthenticator IdP as needed.

Run SSL VPN web mode authentication for a remote user.

The SAML login page appears.