auto-select group when a certificate provides enough information

When a certificate contains a single group there is no need to
request the user to select. Auto-select the group.

Resolves: #692

Signed-off-by: Nikos Mavrogiannopoulos <n.mavrogiannopoulos@gmail.com>

tests/certs/user-group-single-cert.pem

@@ -0,0 +1,20 @@
+-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

tests/certs/user-group-single-cert.tmpl

@@ -0,0 +1,7 @@
+dn = "uid=test,ou=onlygroup"
+tls_www_client
+signing_key
+encryption_key
+expiration_days = -1
+activation_date = "2013-06-06 14:51:29"
+serial = 0x6a9b3401

tests/data/test-group-cert-autoselect-filter.config

@@ -0,0 +1,179 @@
+# User authentication method. Could be set multiple times and in that case
+# all should succeed.
+# Options: certificate, pam.
+auth = "certificate"
+#auth = "plain[@SRCDIR@/data/test-group.passwd]"
+#auth = "pam"
+
+isolate-workers = @ISOLATE_WORKERS@
+
+# A banner to be displayed on clients
+#banner = "Welcome"
+
+# Use listen-host to limit to a specific IP or to the IPs of a provided hostname.
+#listen-host = [IP|HOSTNAME]
+
+use-dbus = no
+
+# Limit the number of clients. Unset or set to zero for unlimited.
+#max-clients = 1024
+max-clients = 16
+
+# Limit the number of client connections to one every X milliseconds
+# (X is the provided value). Set to zero for no limit.
+#rate-limit-ms = 100
+
+# Limit the number of identical clients (i.e., users connecting multiple times)
+# Unset or set to zero for unlimited.
+max-same-clients = 2
+
+# TCP and UDP port number
+tcp-port = @PORT@
+udp-port = @PORT@
+
+# Keepalive in seconds
+keepalive = 32400
+
+# Dead peer detection in seconds
+dpd = 440
+
+# MTU discovery (DPD must be enabled)
+try-mtu-discovery = false
+
+# The key and the certificates of the server
+# The key may be a file, or any URL supported by GnuTLS (e.g.,
+# tpmkey:uuid=xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxx;storage=user
+# or pkcs11:object=my-vpn-key;object-type=private)
+#
+# There may be multiple certificate and key pairs and each key
+# should correspond to the preceding certificate.
+server-cert = @SRCDIR@/certs/server-cert.pem
+server-key = @SRCDIR@/certs/server-key.pem
+
+# Diffie-Hellman parameters. Only needed if you require support
+# for the DHE ciphersuites (by default this server supports ECDHE).
+# Can be generated using:
+# certtool --generate-dh-params --outfile /path/to/dh.pem
+#dh-params = /path/to/dh.pem
+
+# If you have a certificate from a CA that provides an OCSP
+# service you may provide a fresh OCSP status response within
+# the TLS handshake. That will prevent the client from connecting
+# independently on the OCSP server.
+# You can update this response periodically using:
+# ocsptool --ask --load-cert=your_cert --load-issuer=your_ca --outfile response
+# Make sure that you replace the following file in an atomic way.
+#ocsp-response = /path/to/ocsp.der
+
+# In case PKCS #11 or TPM keys are used the PINs should be available
+# in files. The srk-pin-file is applicable to TPM keys only (It's the storage
+# root key).
+#pin-file = /path/to/pin.txt
+#srk-pin-file = /path/to/srkpin.txt
+
+# The Certificate Authority that will be used
+# to verify clients if certificate authentication
+# is set.
+ca-cert = @SRCDIR@/certs/ca.pem
+
+# The object identifier that will be used to read the user ID in the client certificate.
+# The object identifier should be part of the certificate's DN
+# Useful OIDs are:
+#  CN = 2.5.4.3, UID = 0.9.2342.19200300.100.1.1
+cert-user-oid = 0.9.2342.19200300.100.1.1
+
+# The object identifier that will be used to read the user group in the client
+# certificate. The object identifier should be part of the certificate's DN
+# Useful OIDs are:
+#  OU (organizational unit) = 2.5.4.11
+cert-group-oid = 2.5.4.11
+
+# Only "onlygroup" is an eligible group.  Used to test that auto_select_cert_group()
+# correctly filters cert groups against the configured list.
+select-group = onlygroup
+
+# A revocation list of ca-cert is set
+#crl = /path/to/crl.pem
+
+# GnuTLS priority string
+tls-priorities = "PERFORMANCE:%SERVER_PRECEDENCE:%COMPAT"
+
+# To enforce perfect forward secrecy (PFS) on the main channel.
+#tls-priorities = "NORMAL:%SERVER_PRECEDENCE:%COMPAT:-RSA"
+
+# The time (in seconds) that a client is allowed to stay connected prior
+# to authentication
+auth-timeout = 40
+
+# Script to call when a client connects and obtains an IP
+# Parameters are passed on the environment.
+# REASON, USERNAME, GROUPNAME, HOSTNAME (the hostname selected by client),
+# DEVICE, IP_REAL (the real IP of the client), IP_LOCAL (the local IP
+# in the P-t-P connection), IP_REMOTE (the VPN IP of the client). REASON
+# may be "connect" or "disconnect".
+#connect-script = /usr/bin/myscript
+#disconnect-script = /usr/bin/myscript
+
+# UTMP
+use-utmp = true
+
+# PID file
+pid-file = ./ocserv.pid
+
+# The default server directory. Does not require any devices present.
+#chroot-dir = /path/to/chroot
+
+# socket file used for IPC, will be appended with .PID
+# It must be accessible within the chroot environment (if any)
+socket-file = ./ocserv-socket
+
+# The user the worker processes will be run as. It should be
+# unique (no other services run as this user).
+run-as-user = @USERNAME@
+run-as-group = @GROUP@
+
+# Network settings
+
+device = vpns
+
+# The default domain to be advertised
+default-domain = example.com
+
+ipv4-network = 192.168.1.0
+ipv4-netmask = 255.255.255.0
+# Use the keyword local to advertise the local P-t-P address as DNS server
+ipv4-dns = 192.168.1.1
+
+# The NBNS server (if any)
+#ipv4-nbns = 192.168.2.3
+
+#ipv6-address =
+#ipv6-mask =
+#ipv6-dns =
+
+# Prior to leasing any IP from the pool ping it to verify that
+# it is not in use by another (unrelated to this server) host.
+ping-leases = false
+
+# Leave empty to assign the default MTU of the device
+# mtu =
+
+route = 192.168.1.0/255.255.255.0
+#route = 192.168.5.0/255.255.255.0
+
+#
+# The following options are for (experimental) AnyConnect client
+# compatibility. They are only available if the server is built
+# with --enable-anyconnect
+#
+
+# Client profile xml. A sample file exists in doc/profile.xml.
+# This file must be accessible from inside the worker's chroot.
+# The profile is ignored by the openconnect client.
+#user-profile = profile.xml
+
+# Unless set to false it is required for clients to present their
+# certificate even if they are authenticating via a previously granted
+# cookie. Legacy CISCO clients do not do that, and thus this option
+# should be set for them.
+cisco-client-compat = true

tests/data/test-group-cert-autoselect.config

@@ -0,0 +1,175 @@
+# User authentication method. Could be set multiple times and in that case
+# all should succeed.
+# Options: certificate, pam.
+auth = "certificate"
+#auth = "plain[@SRCDIR@/data/test-group.passwd]"
+#auth = "pam"
+
+isolate-workers = @ISOLATE_WORKERS@
+
+# A banner to be displayed on clients
+#banner = "Welcome"
+
+# Use listen-host to limit to a specific IP or to the IPs of a provided hostname.
+#listen-host = [IP|HOSTNAME]
+
+use-dbus = no
+
+# Limit the number of clients. Unset or set to zero for unlimited.
+#max-clients = 1024
+max-clients = 16
+
+# Limit the number of client connections to one every X milliseconds
+# (X is the provided value). Set to zero for no limit.
+#rate-limit-ms = 100
+
+# Limit the number of identical clients (i.e., users connecting multiple times)
+# Unset or set to zero for unlimited.
+max-same-clients = 2
+
+# TCP and UDP port number
+tcp-port = @PORT@
+udp-port = @PORT@
+
+# Keepalive in seconds
+keepalive = 32400
+
+# Dead peer detection in seconds
+dpd = 440
+
+# MTU discovery (DPD must be enabled)
+try-mtu-discovery = false
+
+# The key and the certificates of the server
+# The key may be a file, or any URL supported by GnuTLS (e.g.,
+# tpmkey:uuid=xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxx;storage=user
+# or pkcs11:object=my-vpn-key;object-type=private)
+#
+# There may be multiple certificate and key pairs and each key
+# should correspond to the preceding certificate.
+server-cert = @SRCDIR@/certs/server-cert.pem
+server-key = @SRCDIR@/certs/server-key.pem
+
+# Diffie-Hellman parameters. Only needed if you require support
+# for the DHE ciphersuites (by default this server supports ECDHE).
+# Can be generated using:
+# certtool --generate-dh-params --outfile /path/to/dh.pem
+#dh-params = /path/to/dh.pem
+
+# If you have a certificate from a CA that provides an OCSP
+# service you may provide a fresh OCSP status response within
+# the TLS handshake. That will prevent the client from connecting
+# independently on the OCSP server.
+# You can update this response periodically using:
+# ocsptool --ask --load-cert=your_cert --load-issuer=your_ca --outfile response
+# Make sure that you replace the following file in an atomic way.
+#ocsp-response = /path/to/ocsp.der
+
+# In case PKCS #11 or TPM keys are used the PINs should be available
+# in files. The srk-pin-file is applicable to TPM keys only (It's the storage
+# root key).
+#pin-file = /path/to/pin.txt
+#srk-pin-file = /path/to/srkpin.txt
+
+# The Certificate Authority that will be used
+# to verify clients if certificate authentication
+# is set.
+ca-cert = @SRCDIR@/certs/ca.pem
+
+# The object identifier that will be used to read the user ID in the client certificate.
+# The object identifier should be part of the certificate's DN
+# Useful OIDs are:
+#  CN = 2.5.4.3, UID = 0.9.2342.19200300.100.1.1
+cert-user-oid = 0.9.2342.19200300.100.1.1
+
+# The object identifier that will be used to read the user group in the client
+# certificate. The object identifier should be part of the certificate's DN
+# Useful OIDs are:
+#  OU (organizational unit) = 2.5.4.11
+cert-group-oid = 2.5.4.11
+
+# A revocation list of ca-cert is set
+#crl = /path/to/crl.pem
+
+# GnuTLS priority string
+tls-priorities = "PERFORMANCE:%SERVER_PRECEDENCE:%COMPAT"
+
+# To enforce perfect forward secrecy (PFS) on the main channel.
+#tls-priorities = "NORMAL:%SERVER_PRECEDENCE:%COMPAT:-RSA"
+
+# The time (in seconds) that a client is allowed to stay connected prior
+# to authentication
+auth-timeout = 40
+
+# Script to call when a client connects and obtains an IP
+# Parameters are passed on the environment.
+# REASON, USERNAME, GROUPNAME, HOSTNAME (the hostname selected by client),
+# DEVICE, IP_REAL (the real IP of the client), IP_LOCAL (the local IP
+# in the P-t-P connection), IP_REMOTE (the VPN IP of the client). REASON
+# may be "connect" or "disconnect".
+#connect-script = /usr/bin/myscript
+#disconnect-script = /usr/bin/myscript
+
+# UTMP
+use-utmp = true
+
+# PID file
+pid-file = ./ocserv.pid
+
+# The default server directory. Does not require any devices present.
+#chroot-dir = /path/to/chroot
+
+# socket file used for IPC, will be appended with .PID
+# It must be accessible within the chroot environment (if any)
+socket-file = ./ocserv-socket
+
+# The user the worker processes will be run as. It should be
+# unique (no other services run as this user).
+run-as-user = @USERNAME@
+run-as-group = @GROUP@
+
+# Network settings
+
+device = vpns
+
+# The default domain to be advertised
+default-domain = example.com
+
+ipv4-network = 192.168.1.0
+ipv4-netmask = 255.255.255.0
+# Use the keyword local to advertise the local P-t-P address as DNS server
+ipv4-dns = 192.168.1.1
+
+# The NBNS server (if any)
+#ipv4-nbns = 192.168.2.3
+
+#ipv6-address =
+#ipv6-mask =
+#ipv6-dns =
+
+# Prior to leasing any IP from the pool ping it to verify that
+# it is not in use by another (unrelated to this server) host.
+ping-leases = false
+
+# Leave empty to assign the default MTU of the device
+# mtu =
+
+route = 192.168.1.0/255.255.255.0
+#route = 192.168.5.0/255.255.255.0
+
+#
+# The following options are for (experimental) AnyConnect client
+# compatibility. They are only available if the server is built
+# with --enable-anyconnect
+#
+
+# Client profile xml. A sample file exists in doc/profile.xml.
+# This file must be accessible from inside the worker's chroot.
+# The profile is ignored by the openconnect client.
+#user-profile = profile.xml
+
+# Unless set to false it is required for clients to present their
+# certificate even if they are authenticating via a previously granted
+# cookie. Legacy CISCO clients do not do that, and thus this option
+# should be set for them.
+cisco-client-compat = true

tests/meson.build

@@ -147,7 +147,8 @@ if have_cwrap
     'haproxy-proxyproto', 'haproxy-proxyproto-v1',
     'drain-server', 'drain-server-fail',
     'test-ignore-querystring-of-post',
-    'test-group-cert', 'test-fork', 'test-pass-svc', 'test-cert-svc',
+    'test-group-cert', 'test-group-cert-autoselect',
+    'test-fork', 'test-pass-svc', 'test-cert-svc',
     'test-secmod-kill', 'test-syslog-facility',
   ]
 

tests/test-group-cert-autoselect

@@ -0,0 +1,291 @@
+#!/bin/bash
+#
+# Copyright (C) 2026 Nikos Mavrogiannopoulos
+#
+# This file is part of ocserv.
+#
+# ocserv is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation; either version 2 of the License, or (at
+# your option) any later version.
+#
+# ocserv is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GnuTLS; if not, write to the Free Software Foundation,
+# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+SERV="${SERV:-../src/ocserv}"
+srcdir=${srcdir:-.}
+NO_NEED_ROOT=1
+HEAD=$(mktemp)
+POST=$(mktemp)
+OUTFILE=$(mktemp)
+
+. `dirname $0`/common.sh
+
+eval "${GETPORT}"
+
+echo "Testing cert-group auto-selection (#692)"
+
+# Reproducer for #692: when cert-group-oid is configured and the client
+# certificate carries exactly one group, and no "select-group" list is
+# configured (so there is nothing to disambiguate), the server must not
+# force an extra "select your group" round trip before completing
+# authentication.
+
+function finish {
+  set +e
+  echo " * Cleaning up..."
+  test -n "${CONFIG}" && rm -f ${CONFIG} >/dev/null 2>&1
+  rm -f $HEAD $POST $OUTFILE >/dev/null 2>&1
+  cleanup
+}
+trap finish EXIT
+
+update_config test-group-cert-autoselect.config
+launch_simple_sr_server -d 1 -f -c ${CONFIG}
+PID=$!
+wait_server $PID
+
+TARGET=https://$ADDRESS:$PORT
+
+cat >$HEAD <<_EOF
+Accept-Encoding:identity
+X-Transcend-Version:1
+X-Aggregate-Auth:1
+Connection:close
+_EOF
+
+echo " * Sanity check: explicit group-select with a single certificate group"
+
+# Sanity check: explicitly selecting the (only) certificate group works
+# and completes authentication immediately.
+cat >$POST <<_EOF
+<?xml version="1.0" encoding="UTF-8"?>
+<config-auth client="vpn" type="init" aggregate-auth-version="2">
+<group-select>onlygroup</group-select>
+</config-auth>
+_EOF
+
+LD_PRELOAD=libsocket_wrapper.so curl -i -A 'OpenConnect VPN Agent v9.12' \
+	-H @$HEAD -k \
+	--cert ${srcdir}/certs/user-group-single-cert.pem \
+	--key ${srcdir}/certs/user-group-key.pem \
+	-d@$POST $TARGET >$OUTFILE
+
+grep 'auth id="success"' $OUTFILE >/dev/null
+if test $? != 0; then
+	echo "Explicit group selection did not complete authentication"
+	echo "==========================================================="
+	cat $OUTFILE
+	exit 1
+fi
+
+grep "Set-Cookie: webvpncontext=" $OUTFILE >/dev/null
+if test $? != 0; then
+	echo "Explicit group selection did not result in a session cookie"
+	echo "============================================================="
+	cat $OUTFILE
+	exit 1
+fi
+
+echo " * OK: explicit group selection completed authentication"
+
+echo " * Reproducer: single eligible certificate group, no group-select sent"
+
+# The actual reproducer: the client certificate has exactly one group
+# (OU=onlygroup) and the server has no "select-group" list configured
+# (so the single certificate group is unambiguous). Authenticate without
+# sending a <group-select> at all, as a first-contact AnyConnect client
+# would. Authentication must complete directly, without an extra
+# "Please select your group" prompt.
+cat >$POST <<_EOF
+<?xml version="1.0" encoding="UTF-8"?>
+<config-auth client="vpn" type="init" aggregate-auth-version="2">
+<version who="vpn">4.8.03036</version>
+</config-auth>
+_EOF
+
+LD_PRELOAD=libsocket_wrapper.so curl -i -A 'OpenConnect VPN Agent v9.12' \
+	-H @$HEAD -k \
+	--cert ${srcdir}/certs/user-group-single-cert.pem \
+	--key ${srcdir}/certs/user-group-key.pem \
+	-d@$POST $TARGET >$OUTFILE
+
+grep "Please select your group" $OUTFILE >/dev/null
+if test $? = 0; then
+	echo "Server asked to select a group despite the certificate"
+	echo "containing a single, unambiguous group and no configured"
+	echo "select-group list (issue #692)"
+	echo "=========================================================="
+	cat $OUTFILE
+	exit 1
+fi
+
+grep 'auth id="success"' $OUTFILE >/dev/null
+if test $? != 0; then
+	echo "Authentication did not complete with the certificate's"
+	echo "sole group automatically selected"
+	echo "========================================================"
+	cat $OUTFILE
+	exit 1
+fi
+
+grep "Set-Cookie: webvpncontext=" $OUTFILE >/dev/null
+if test $? != 0; then
+	echo "Automatic group selection did not result in a session cookie"
+	echo "=============================================================="
+	cat $OUTFILE
+	exit 1
+fi
+
+echo " * OK: certificate's sole group was auto-selected, no prompt sent"
+
+echo " * Ambiguous case: multiple eligible certificate groups, no group-select sent"
+
+# Ambiguous case: the client certificate carries multiple groups
+# (OU=group1, group2, group3, group4) and the server has no
+# "select-group" list configured, so all of them are eligible and there
+# is no single unambiguous group to auto-select. The server must still
+# prompt the client to select a group.
+cat >$POST <<_EOF
+<?xml version="1.0" encoding="UTF-8"?>
+<config-auth client="vpn" type="init" aggregate-auth-version="2">
+<version who="vpn">4.8.03036</version>
+</config-auth>
+_EOF
+
+LD_PRELOAD=libsocket_wrapper.so curl -i -A 'OpenConnect VPN Agent v9.12' \
+	-H @$HEAD -k \
+	--cert ${srcdir}/certs/user-group-cert.pem \
+	--key ${srcdir}/certs/user-group-key.pem \
+	-d@$POST $TARGET >$OUTFILE
+
+grep "Please select your group" $OUTFILE >/dev/null
+if test $? != 0; then
+	echo "Server did not ask to select a group despite the certificate"
+	echo "containing multiple, ambiguous groups and no configured"
+	echo "select-group list"
+	echo "=========================================================="
+	cat $OUTFILE
+	exit 1
+fi
+
+# ocserv always sends a Set-Cookie: webvpncontext= header, even to clear
+# a non-existing one (webvpncontext=; expires=...1970...). Only a
+# non-empty cookie value indicates a completed session.
+grep -E "Set-Cookie: webvpncontext=[^;[:space:]]" $OUTFILE >/dev/null
+if test $? = 0; then
+	echo "Ambiguous group selection unexpectedly resulted in a session cookie"
+	echo "====================================================================="
+	cat $OUTFILE
+	exit 1
+fi
+
+echo " * OK: ambiguous certificate groups still require group selection"
+
+# -----------------------------------------------------------------------
+# Restart the server with select-group = onlygroup to exercise the inner
+# filtering loop in auto_select_cert_group().
+# -----------------------------------------------------------------------
+cleanup
+mkdir -p $SOCKDIR
+
+echo "Testing cert-group auto-selection with select-group filter (#692)"
+
+update_config test-group-cert-autoselect-filter.config
+launch_simple_sr_server -d 1 -f -c ${CONFIG}
+PID=$!
+wait_server $PID
+
+TARGET=https://$ADDRESS:$PORT
+
+echo " * Filtered match: cert group is in select-group list, no group-select sent"
+
+# select-group = onlygroup is configured; the client certificate carries
+# exactly one group (OU=onlygroup) which is in the list.  The eligible set
+# has exactly one entry, so the server must auto-select it and complete
+# authentication without an extra round trip.
+cat >$POST <<_EOF
+<?xml version="1.0" encoding="UTF-8"?>
+<config-auth client="vpn" type="init" aggregate-auth-version="2">
+<version who="vpn">4.8.03036</version>
+</config-auth>
+_EOF
+
+LD_PRELOAD=libsocket_wrapper.so curl -i -A 'OpenConnect VPN Agent v9.12' \
+	-H @$HEAD -k \
+	--cert ${srcdir}/certs/user-group-single-cert.pem \
+	--key ${srcdir}/certs/user-group-key.pem \
+	-d@$POST $TARGET >$OUTFILE
+
+grep "Please select your group" $OUTFILE >/dev/null
+if test $? = 0; then
+	echo "Server prompted for group despite cert's sole group being in"
+	echo "the configured select-group list (select-group filter path)"
+	echo "=========================================================="
+	cat $OUTFILE
+	exit 1
+fi
+
+grep 'auth id="success"' $OUTFILE >/dev/null
+if test $? != 0; then
+	echo "Authentication did not complete with cert group auto-selected"
+	echo "from the configured select-group list"
+	echo "=============================================================="
+	cat $OUTFILE
+	exit 1
+fi
+
+grep "Set-Cookie: webvpncontext=" $OUTFILE >/dev/null
+if test $? != 0; then
+	echo "Filtered auto-selection did not result in a session cookie"
+	echo "============================================================"
+	cat $OUTFILE
+	exit 1
+fi
+
+echo " * OK: cert group in select-group list was auto-selected"
+
+echo " * Filtered non-match: cert groups not in select-group list, no group-select sent"
+
+# select-group = onlygroup is configured; the client certificate carries
+# four groups (OU=group1..4), none of which match "onlygroup".  The eligible
+# set is empty, so the server must fall back to the group selection prompt.
+cat >$POST <<_EOF
+<?xml version="1.0" encoding="UTF-8"?>
+<config-auth client="vpn" type="init" aggregate-auth-version="2">
+<version who="vpn">4.8.03036</version>
+</config-auth>
+_EOF
+
+LD_PRELOAD=libsocket_wrapper.so curl -i -A 'OpenConnect VPN Agent v9.12' \
+	-H @$HEAD -k \
+	--cert ${srcdir}/certs/user-group-cert.pem \
+	--key ${srcdir}/certs/user-group-key.pem \
+	-d@$POST $TARGET >$OUTFILE
+
+grep "Please select your group" $OUTFILE >/dev/null
+if test $? != 0; then
+	echo "Server did not prompt for group despite none of the cert's"
+	echo "groups matching the configured select-group list"
+	echo "=========================================================="
+	cat $OUTFILE
+	exit 1
+fi
+
+grep -E "Set-Cookie: webvpncontext=[^;[:space:]]" $OUTFILE >/dev/null
+if test $? = 0; then
+	echo "Non-matching cert groups unexpectedly resulted in a session cookie"
+	echo "==================================================================="
+	cat $OUTFILE
+	exit 1
+fi
+
+echo " * OK: cert groups not in select-group list still require group selection"
+
+exit 0