ipsec: T1210: add RADIUS authentication for remote-access IKEv2 VPN

set vpn ipsec remote-access connection rw authentication client-mode 'eap-radius'
set vpn ipsec remote-access connection rw authentication id '192.0.2.1'
set vpn ipsec remote-access connection rw authentication server-mode 'x509'
set vpn ipsec remote-access connection rw authentication x509 ca-certificate 'CAcert_Class_3_Root'
set vpn ipsec remote-access connection rw authentication x509 certificate 'vyos'
set vpn ipsec remote-access connection rw esp-group 'ESP-RW'
set vpn ipsec remote-access connection rw ike-group 'IKE-RW'
set vpn ipsec remote-access connection rw local-address '192.0.2.1'
set vpn ipsec remote-access connection rw pool 'ra-rw-ipv4'
set vpn ipsec remote-access connection rw unique 'never'

set vpn ipsec remote-access pool ra-rw-ipv4 name-server '192.0.2.2'
set vpn ipsec remote-access pool ra-rw-ipv4 prefix '192.168.22.0/24'

set vpn ipsec remote-access radius nas-identifier 'fooo'
set vpn ipsec remote-access radius server 172.16.100.10 key 'secret'

4 files changed, 165 insertions, 13 deletions

diff --git a/Makefile b/Makefile
index 32bc58be0..c8f6ac7c9 100644
--- a/Makefile
+++ b/Makefile
@@ -27,7 +27,10 @@ interface_definitions: $(config_xml_obj)
 	find $(BUILD_DIR)/interface-definitions -type f -name "*.xml" | xargs -I {} $(CURDIR)/scripts/build-command-templates {} $(CURDIR)/schema/interface_definition.rng $(TMPL_DIR) || exit 1
 
 	# XXX: delete top level node.def's that now live in other packages
-	rm -f $(TMPL_DIR)/firewall/node.def
+	# IPSec VPN EAP-RADIUS does not support source-address
+	rm -rf $(TMPL_DIR)/vpn/ipsec/remote-access/radius/source-address
+	# T3568: firewall is yet not migrated to XML and Python - this is only a dummy
+	rm -rf $(TMPL_DIR)/firewall/node.def
 	rm -rf $(TMPL_DIR)/nfirewall
 	# XXX: test if there are empty node.def files - this is not allowed as these
 	# could mask help strings or mandatory priority statements
diff --git a/data/templates/ipsec/charon/eap-radius.conf.tmpl b/data/templates/ipsec/charon/eap-radius.conf.tmpl
new file mode 100644
index 000000000..5ec35c988
--- /dev/null
+++ b/data/templates/ipsec/charon/eap-radius.conf.tmpl
@@ -0,0 +1,115 @@
+eap-radius {
+    # Send RADIUS accounting information to RADIUS servers.
+    # accounting = no
+
+    # Close the IKE_SA if there is a timeout during interim RADIUS accounting
+    # updates.
+    # accounting_close_on_timeout = yes
+
+    # Interval in seconds for interim RADIUS accounting updates, if not
+    # specified by the RADIUS server in the Access-Accept message.
+    # accounting_interval = 0
+
+    # If enabled, accounting is disabled unless an IKE_SA has at least one
+    # virtual IP. Only for IKEv2, for IKEv1 a virtual IP is strictly necessary.
+    # accounting_requires_vip = no
+
+    # If enabled, adds the Class attributes received in Access-Accept message to
+    # the RADIUS accounting messages.
+    # accounting_send_class = no
+
+    # Use class attributes in Access-Accept messages as group membership
+    # information.
+    # class_group = no
+
+    # Closes all IKE_SAs if communication with the RADIUS server times out. If
+    # it is not set only the current IKE_SA is closed.
+    # close_all_on_timeout = no
+
+    # Send EAP-Start instead of EAP-Identity to start RADIUS conversation.
+    # eap_start = no
+
+    # Use filter_id attribute as group membership information.
+    # filter_id = no
+
+    # Prefix to EAP-Identity, some AAA servers use a IMSI prefix to select the
+    # EAP method.
+    # id_prefix =
+
+    # Whether to load the plugin. Can also be an integer to increase the
+    # priority of this plugin.
+    load = yes
+
+    # NAS-Identifier to include in RADIUS messages.
+    nas_identifier = {{ remote_access.radius.nas_identifier if remote_access is defined and remote_access.radius is defined and remote_access.radius.nas_identifier is defined else 'strongSwan' }}
+
+    # Port of RADIUS server (authentication).
+    # port = 1812
+
+    # Base to use for calculating exponential back off.
+    # retransmit_base = 1.4
+
+    # Timeout in seconds before sending first retransmit.
+    # retransmit_timeout = 2.0
+
+    # Number of times to retransmit a packet before giving up.
+    # retransmit_tries = 4
+
+    # Shared secret between RADIUS and NAS. If set, make sure to adjust the
+    # permissions of the config file accordingly.
+    # secret =
+
+    # IP/Hostname of RADIUS server.
+    # server =
+
+    # Number of sockets (ports) to use, increase for high load.
+    # sockets = 1
+
+    # Whether to include the UDP port in the Called- and Calling-Station-Id
+    # RADIUS attributes.
+    # station_id_with_port = yes
+
+    dae {
+        # Enables support for the Dynamic Authorization Extension (RFC 5176).
+        # enable = no
+
+        # Address to listen for DAE messages from the RADIUS server.
+        # listen = 0.0.0.0
+
+        # Port to listen for DAE requests.
+        # port = 3799
+
+        # Shared secret used to verify/sign DAE messages. If set, make sure to
+        # adjust the permissions of the config file accordingly.
+        # secret =
+    }
+
+    forward {
+        # RADIUS attributes to be forwarded from IKEv2 to RADIUS.
+        # ike_to_radius =
+
+        # Same as ike_to_radius but from RADIUS to IKEv2.
+        # radius_to_ike =
+    }
+
+    # Section to specify multiple RADIUS servers.
+    servers {
+{%  if remote_access is defined and remote_access.radius is defined and remote_access.radius.server is defined %}
+{%    for server, server_options in remote_access.radius.server.items() if server_options.disable is not defined %}
+        {{ server | replace('.', '-') }} {
+            address = {{ server }}
+            secret = {{ server_options.key }}
+            auth_port = {{ server_options.port }}
+{%      if server_options.disable_accounting is not defined %}
+            acct_port = {{ server_options.port | int +1 }}
+{%  endif %}
+            sockets = 20
+        }
+{%    endfor %}
+{%  endif %}
+    }
+
+    # Section to configure multiple XAuth authentication rounds via RADIUS.
+    xauth {
+    }
+}
diff --git a/interface-definitions/vpn_ipsec.xml.in b/interface-definitions/vpn_ipsec.xml.in
index 858adb13a..165fdfdf3 100644
--- a/interface-definitions/vpn_ipsec.xml.in
+++ b/interface-definitions/vpn_ipsec.xml.in
@@ -703,18 +703,22 @@
                         <properties>
                           <help>Client authentication mode</help>
                           <completionHelp>
-                            <list>eap-tls eap-mschapv2</list>
+                            <list>eap-tls eap-mschapv2 eap-radius</list>
                           </completionHelp>
                           <valueHelp>
                             <format>eap-tls</format>
-                            <description>EAP-TLS</description>
+                            <description>Client uses EAP-TLS authentication</description>
                           </valueHelp>
                           <valueHelp>
                             <format>eap-mschapv2</format>
-                            <description>EAP-MSCHAPv2</description>
+                            <description>Client uses EAP-MSCHAPv2 authentication</description>
+                          </valueHelp>
+                          <valueHelp>
+                            <format>eap-radius</format>
+                            <description>Client uses EAP-RADIUS authentication</description>
                           </valueHelp>
                           <constraint>
-                            <regex>^(eap-tls|eap-mschapv2)$</regex>
+                            <regex>^(eap-tls|eap-mschapv2|eap-radius)$</regex>
                           </constraint>
                         </properties>
                         <defaultValue>eap-mschapv2</defaultValue>
@@ -872,6 +876,17 @@
                   #include <include/accel-ppp/name-server.xml.i>
                 </children>
               </tagNode>
+              #include <include/radius-server-ipv4.xml.i>
+              <node name="radius">
+                <children>
+                  #include <include/radius-nas-identifier.xml.i>
+                  <tagNode name="server">
+                    <children>
+                      #include <include/accel-ppp/radius-additions-disable-accounting.xml.i>
+                    </children>
+                 </tagNode>
+                </children>
+              </node>
             </children>
           </node>
           <node name="site-to-site">
diff --git a/src/conf_mode/vpn_ipsec.py b/src/conf_mode/vpn_ipsec.py
index 123380827..a4cd33e64 100755
--- a/src/conf_mode/vpn_ipsec.py
+++ b/src/conf_mode/vpn_ipsec.py
@@ -49,13 +49,14 @@ airbag.enable()
 dhcp_wait_attempts = 2
 dhcp_wait_sleep = 1
 
-swanctl_dir    = '/etc/swanctl'
-ipsec_conf     = '/etc/ipsec.conf'
-ipsec_secrets  = '/etc/ipsec.secrets'
-charon_conf = '/etc/strongswan.d/charon.conf'
-charon_dhcp_conf = '/etc/strongswan.d/charon/dhcp.conf'
-interface_conf = '/etc/strongswan.d/interfaces_use.conf'
-swanctl_conf   = f'{swanctl_dir}/swanctl.conf'
+swanctl_dir        = '/etc/swanctl'
+ipsec_conf         = '/etc/ipsec.conf'
+ipsec_secrets      = '/etc/ipsec.secrets'
+charon_conf        = '/etc/strongswan.d/charon.conf'
+charon_dhcp_conf   = '/etc/strongswan.d/charon/dhcp.conf'
+charon_radius_conf = '/etc/strongswan.d/charon/eap-radius.conf'
+interface_conf     = '/etc/strongswan.d/interfaces_use.conf'
+swanctl_conf       = f'{swanctl_dir}/swanctl.conf'
 
 default_install_routes = 'yes'
 
@@ -110,6 +111,12 @@ def get_config(config=None):
             ipsec['remote_access']['connection'][rw] = dict_merge(default_values,
               ipsec['remote_access']['connection'][rw])
 
+    if 'remote_access' in ipsec and 'radius' in ipsec['remote_access'] and 'server' in ipsec['remote_access']['radius']:
+        default_values = defaults(base + ['remote-access', 'radius', 'server'])
+        for server in ipsec['remote_access']['radius']['server']:
+            ipsec['remote_access']['radius']['server'][server] = dict_merge(default_values,
+                ipsec['remote_access']['radius']['server'][server])
+
     ipsec['dhcp_no_address'] = {}
     ipsec['install_routes'] = 'no' if conf.exists(base + ["options", "disable-route-autoinstall"]) else default_install_routes
     ipsec['interface_change'] = leaf_node_changed(conf, base + ['interface'])
@@ -263,6 +270,12 @@ def verify(ipsec):
                     if 'pre_shared_secret' not in ra_conf['authentication']:
                         raise ConfigError(f"Missing pre-shared-key on {name} remote-access config")
 
+
+                if 'client_mode' in ra_conf['authentication']:
+                    if ra_conf['authentication']['client_mode'] == 'eap-radius':
+                        if 'radius' not in ipsec['remote_access'] or 'server' not in ipsec['remote_access']['radius'] or len(ipsec['remote_access']['radius']['server']) == 0:
+                            raise ConfigError('RADIUS authentication requires at least one server')
+
                 if 'pool' in ra_conf:
                     if 'dhcp' in ra_conf['pool'] and len(ra_conf['pool']) > 1:
                         raise ConfigError(f'Can not use both DHCP and a predefined address pool for "{name}"!')
@@ -297,6 +310,10 @@ def verify(ipsec):
                         if v4_addr_and_exclude or v6_addr_and_exclude:
                            raise ConfigError('Must use both IPv4 or IPv6 addresses for pool prefix and exclude prefixes!')
 
+        if 'radius' in ipsec['remote_access'] and 'server' in ipsec['remote_access']['radius']:
+            for server, server_config in ipsec['remote_access']['radius']['server'].items():
+                if 'key' not in server_config:
+                    raise ConfigError(f'Missing RADIUS secret key for server "{server}"')
 
     if 'site_to_site' in ipsec and 'peer' in ipsec['site_to_site']:
         for peer, peer_conf in ipsec['site_to_site']['peer'].items():
@@ -449,7 +466,8 @@ def generate(ipsec):
     cleanup_pki_files()
 
     if not ipsec:
-        for config_file in [ipsec_conf, ipsec_secrets, charon_dhcp_conf, interface_conf, swanctl_conf]:
+        for config_file in [ipsec_conf, ipsec_secrets, charon_dhcp_conf,
+                            charon_radius_conf, interface_conf, swanctl_conf]:
             if os.path.isfile(config_file):
                 os.unlink(config_file)
         render(charon_conf, 'ipsec/charon.tmpl', {'install_routes': default_install_routes})
@@ -518,6 +536,7 @@ def generate(ipsec):
     render(ipsec_secrets, 'ipsec/ipsec.secrets.tmpl', ipsec)
     render(charon_conf, 'ipsec/charon.tmpl', ipsec)
     render(charon_dhcp_conf, 'ipsec/charon/dhcp.conf.tmpl', ipsec)
+    render(charon_radius_conf, 'ipsec/charon/eap-radius.conf.tmpl', ipsec)
     render(interface_conf, 'ipsec/interfaces_use.conf.tmpl', ipsec)
     render(swanctl_conf, 'ipsec/swanctl.conf.tmpl', ipsec)