1OCSERV(8)                                                            OCSERV(8)
2
3
4

NAME

6       ocserv - OpenConnect VPN server
7

SYNOPSIS

9       ocserv options -c [config]
10
11       Openconnect  VPN  server  (ocserv)  is a VPN server compatible with the
12       openconnect VPN client. It follows the AnyConnect VPN protocol which is
13       used by several CISCO routers.
14

DESCRIPTION

16       This a standalone server that reads a configuration file (see below for
17       more details), and waits for client connections. Log messages are redi‐
18       rected to daemon facility.
19
20       The server maintains two connections/channels with the client. The main
21       VPN channel is established over TCP, HTTP and TLS. This is the  control
22       channel  as  well as the backup data channel. After its establishment a
23       UDP channel using DTLS is initiated which serves as the main data chan‐
24       nel.  If  the UDP channel fails to establish or is temporarily unavail‐
25       able the backup channel over TCP/TLS is being used.
26
27       This server supports multiple authentication methods, including PAM and
28       certificate authentication. Authenticated users are assigned an unpriv‐
29       ileged worker process and obtain a networking (tun) device  and  an  IP
30       from a configurable pool of addresses.
31
32       Once  authenticated,  the server provides the client with an IP address
33       and a list of routes that it may access. In order to  allow  high-speed
34       transfers the server does not process or filter packets. It is expected
35       that the server has or will set up  any  required  routes  or  firewall
36       rules.
37
38       It  is possible to separate users into groups, which are either present
39       on their certificate, or presented on login for  the  user  to  choose.
40       That  way  a user may take advantage of the different settings that may
41       apply per group. See the comments on the configuration  file  for  more
42       information.
43
44       It  is  also possible to run hostname-based virtual servers which could
45       support different authentication methods. When multiple virtual servers
46       are  present  clients  are  distinguished by the advertised server name
47       over TLS (SNI). Clients which do not support or sent SNI, are  directed
48       to the default server.
49

OPTIONS

51       -f, --foreground:
52              Do not fork server into background.
53
54       -d, --debug=num:
55              Enable  verbose  network  debugging  information.  num  must  be
56              between zero and 9999.
57
58       -c, --config=FILE:
59              Specify the configuration file for the server.
60
61       -t, --test-config:
62              Test the provided configuration file and exit. A successful exit
63              error code indicates a valid configuration.
64
65       -p, --pid-file=FILE:
66              Specify a PID file for the server.
67
68       -h, --help:
69              Display usage information and exit.
70
71       -v, --version:
72              Output version of program and exit.
73

AUTHENTICATION

75       Users can be authenticated in multiple ways, which are explained in the
76       following paragraphs. Connected users can be managed  using  the  occtl
77       tool.
78
79   Password authentication
80       If  your  system  supports Pluggable Authentication Modules (PAM), then
81       ocserv will take advantage of it to password  authenticate  its  users.
82       Otherwise  a  plain  password file similar to the UNIX password file is
83       also supported. In that case the ´ocpasswd´ tool can be  used  for  its
84       management.  Note  that password authentication can be used in conjunc‐
85       tion with certificate authentication.
86
87   GSSAPI authentication
88       ocserv  will  take  advantage  of  the  MIT  Kerberos  project   GSSAPI
89       libraries,  and  allow authentication using any method GSSAPI supports.
90       That is, mainly, Kerberos authentication. That is often more useful  to
91       be combined with PAM or other password authentication methods so that a
92       fallback mechanism can be used when GSSAPI fails (e.g., when  the  user
93       doesn´t  already  have a Kerberos ticket). The GSSAPI authentication is
94       implemented using SPNEGO over HTTP (RFC4559).
95
96   Public key (certificate) authentication
97       Public key authentication allows the user to be  authenticated  by  the
98       possession of the private key that corresponds to a known to the server
99       public key. That allows the  usage  of  common  smart  cards  for  user
100       authentication.
101
102       In ocserv, a certificate authority (CA) is used to sign the client cer‐
103       tificates. That certificate authority can be local, used  only  by  the
104       server  to  sign  its  user´s known public keys which are then given to
105       users in a form of certificates. That authority need also provide a CRL
106       to allow the server to reject the revoked clients (see ca-cert, crl).
107
108       In  certificate  authentication  each client presents a certificate and
109       signs data provided by the server, as part of  TLS  authentication,  to
110       prove  his possession of the corresponding private key. The certificate
111       need also contain user identifying information, for example,  the  user
112       ID  of  the  client must be embedded in the certificate´s Distinguished
113       Name (DN), i.e., in the Common Name, or UID fields. For the  server  to
114       read the name, the cert-user-oid configuration option must be set.
115
116       The  following  examples demonstrate how to use certtool from GnuTLS to
117       generate such CA.
118
119   Generating the CA
120       $ certtool --generate-privkey --outfile ca-key.pem
121       $ cat << _EOF_ >ca.tmpl
122       cn = "VPN CA"
123       organization = "Big Corp"
124       serial = 1
125       expiration_days = -1
126       ca
127       signing_key
128       cert_signing_key
129       crl_signing_key
130       _EOF_
131
132       $ certtool --generate-self-signed --load-privkey ca-key.pem \
133                  --template ca.tmpl --outfile ca-cert.pem
134
135   Generating a local server certificate
136       The following example generates the server key  and  certificate  pair.
137       The  key  generated  is  an RSA one, but different types can be used by
138       specifying the ´ecdsa´ or ´dsa´ options to certtool.
139
140
141
142           $ certtool --generate-privkey --outfile server-key.pem
143           $ cat << _EOF_ >server.tmpl
144           cn = "VPN server"
145           dns_name = "www.example.com"
146           dns_name = "vpn1.example.com"
147           #ip_address = "1.2.3.4"
148           organization = "MyCompany"
149           expiration_days = -1
150           signing_key
151           encryption_key #only if the generated key is an RSA one
152           tls_www_server
153           _EOF_
154
155           $ certtool --generate-certificate --load-privkey server-key.pem \
156                      --load-ca-certificate ca-cert.pem --load-ca-privkey ca-key.pem \
157                      --template server.tmpl --outfile server-cert.pem
158
159
160
161       From this point the clients need ca-cert.pem to  be  able  to  securely
162       connect to the server.
163
164       Note  that  it  is  a better practice to use two separate RSA keys, one
165       with the signing_key option and another with the encryption_key.
166
167   Generating an external CA-signed server certificate
168       $ certtool --generate-privkey --outfile server-key.pem
169       $ cat << _EOF_ >server.tmpl
170       cn = "My server"
171       dns_name = "www.example.com"
172       organization = "MyCompany"
173       expiration_days = -1
174       signing_key
175       encryption_key #only if the generated key is an RSA one
176       tls_www_server
177       _EOF_
178       $ certtool --generate-request --load-privkey server-key.pem \
179                  --template server.tmpl --outfile server-cert.csr
180
181       At this point you need to provide the server-cert.csr to your  CA,  and
182       they will send you the server certificate.
183
184   Generating the client certificates
185       Note  that it is recommended to leave detailed personal information out
186       of the certificate as it is sent in clear  during  TLS  authentication.
187       The  following  process generates a certificate and converts it to PKCS
188       #12 that is protected by a PIN and most clients are able to import (the
189       3DES  cipher is used in the example because it is supported by far more
190       devices than AES).
191
192
193
194           $ certtool --generate-privkey --outfile user-key.pem
195           $ cat << _EOF_ >user.tmpl
196           cn = "user"
197           unit = "admins"
198           expiration_days = 365
199           signing_key
200           tls_www_client
201           _EOF_
202           $ certtool --generate-certificate --load-privkey user-key.pem \
203                      --load-ca-certificate ca-cert.pem --load-ca-privkey ca-key.pem \
204                      --template user.tmpl --outfile user-cert.pem
205
206           $ certtool --to-p12 --load-privkey user-key.pem \
207                      --pkcs-cipher 3des-pkcs12 \
208                      --load-certificate user-cert.pem \
209                      --outfile user.p12 --outder
210
211
212
213   Revoking a client certificate
214       To revoke the previous client certificate, i.e.,  preventing  the  user
215       from  accessing  the VPN resources prior to its certificate expiration,
216       use:
217
218
219
220           $ cat << _EOF_ >crl.tmpl
221           crl_next_update = 365
222           crl_number = 1
223           _EOF_
224           $ cat user-cert.pem >>revoked.pem
225           $ certtool --generate-crl --load-ca-privkey ca-key.pem \
226                      --load-ca-certificate ca-cert.pem --load-certificate revoked.pem \
227                      --template crl.tmpl --outfile crl.pem
228
229
230
231       After that you may want to notify ocserv of the new CRL  by  using  the
232       HUP signal, or wait for it to reload it.
233
234       When  there are no revoked certificates an empty revocation list should
235       be generated as follows.
236
237
238
239           $ certtool --generate-crl --load-ca-privkey ca-key.pem \
240                      --load-ca-certificate ca-cert.pem \
241                      --template crl.tmpl --outfile crl.pem
242
243
244

IMPLEMENTATION NOTES

246       Note that while this  server  utilizes  privilege  separation  and  all
247       authentication  occurs  on the security module, this does not apply for
248       TLS client certificate authentication. That is due to TLS protocol lim‐
249       itation.
250

NETWORKING CONSIDERATIONS

252       In  certain  setups,  where  a firewall may be blocking ICMP responses,
253       setting the MSS of TCP connections to MTU  will  eliminate  the  "black
254       hole"   connection   issues.   See   http://lartc.org/howto/lartc.cook
255       book.mtu-mss.html for instructions to enable it on a Linux system.
256

FILES

258   ocserv´s configuration file format
259       By default, if no other file is specified, ocserv looks for its config‐
260       uration  file at /etc/ocserv/ocserv.conf. An example configuration file
261       follows.
262
263
264
265           ### The following directives do not change with server reload.
266
267           # User authentication method. To require multiple methods to be
268           # used for the user to login, add multiple auth directives. The values
269           # in the ´auth´ directive are AND composed (if multiple all must
270           # succeed).
271           # Available options: certificate, plain, pam, radius, gssapi.
272           # Note that authentication methods utilizing passwords cannot be
273           # combined (e.g., the plain, pam or radius methods).
274
275           # certificate:
276           #  This indicates that all connecting users must present a certificate.
277           #  The username and user group will be then extracted from it (see
278           #  cert-user-oid and cert-group-oid). The certificate to be accepted
279           #  it must be signed by the CA certificate as specified in ´ca-cert´ and
280           #  it must not be listed in the CRL, as specified by the ´crl´ option.
281           #
282           # pam[gid-min=1000]:
283           #  This enabled PAM authentication of the user. The gid-min option is used
284           # by auto-select-group option, in order to select the minimum valid group ID.
285           #
286           # plain[passwd=/etc/ocserv/ocpasswd,otp=/etc/ocserv/users.otp]
287           #  The plain option requires specifying a password file which contains
288           # entries of the following format.
289           # "username:groupname1,groupname2:encoded-password"
290           # One entry must be listed per line, and ´ocpasswd´ should be used
291           # to generate password entries. The ´otp´ suboption allows one to specify
292           # an oath password file to be used for one time passwords; the format of
293           # the file is described in https://github.com/archiecobbs/mod-authn-otp/wiki/UsersFile
294           #
295           # radius[config=/etc/radiusclient/radiusclient.conf,groupconfig=true,nas-identifier=name]:
296           #  The radius option requires specifying freeradius-client configuration
297           # file. If the groupconfig option is set, then config-per-user/group will be overridden,
298           # and all configuration will be read from radius. That also includes the
299           # Acct-Interim-Interval, and Session-Timeout values.
300           #
301           # See doc/README-radius.md for the supported radius configuration atributes.
302           #
303           # gssapi[keytab=/etc/key.tab,require-local-user-map=true,tgt-freshness-time=900]
304           #  The gssapi option allows one to use authentication methods supported by GSSAPI,
305           # such as Kerberos tickets with ocserv. It should be best used as an alternative
306           # to PAM (i.e., have pam in auth and gssapi in enable-auth), to allow users with
307           # tickets and without tickets to login. The default value for require-local-user-map
308           # is true. The ´tgt-freshness-time´ if set, it would require the TGT tickets presented
309           # to have been issued within the provided number of seconds. That option is used to
310           # restrict logins even if the KDC provides long time TGT tickets.
311
312           #auth = "pam"
313           #auth = "pam[gid-min=1000]"
314           #auth = "plain[passwd=./sample.passwd,otp=./sample.otp]"
315           auth = "plain[passwd=./sample.passwd]"
316           #auth = "certificate"
317           #auth = "radius[config=/etc/radiusclient/radiusclient.conf,groupconfig=true]"
318
319           # Specify alternative authentication methods that are sufficient
320           # for authentication. That is, if set, any of the methods enabled
321           # will be sufficient to login, irrespective of the main ´auth´ entries.
322           # When multiple options are present, they are OR composed (any of them
323           # succeeding allows login).
324           #enable-auth = "certificate"
325           #enable-auth = "gssapi"
326           #enable-auth = "gssapi[keytab=/etc/key.tab,require-local-user-map=true,tgt-freshness-time=900]"
327
328           # Accounting methods available:
329           # radius: can be combined with any authentication method, it provides
330           #      radius accounting to available users (see also stats-report-time).
331           #
332           # pam: can be combined with any authentication method, it provides
333           #      a validation of the connecting user´s name using PAM. It is
334           #      superfluous to use this method when authentication is already
335           #      PAM.
336           #
337           # Only one accounting method can be specified.
338           #acct = "radius[config=/etc/radiusclient/radiusclient.conf]"
339
340           # Use listen-host to limit to specific IPs or to the IPs of a provided
341           # hostname.
342           #listen-host = [IP|HOSTNAME]
343
344           # Use udp-listen-host to limit udp to specific IPs or to the IPs of a provided
345           # hostname. if not set, listen-host will be used
346           #udp-listen-host = [IP|HOSTNAME]
347
348           # When the server has a dynamic DNS address (that may change),
349           # should set that to true to ask the client to resolve again on
350           # reconnects.
351           #listen-host-is-dyndns = true
352
353           # move the listen socket within the specified network namespace
354           # listen-netns = "foo"
355
356           # TCP and UDP port number
357           tcp-port = 443
358           udp-port = 443
359
360           # Accept connections using a socket file. It accepts HTTP
361           # connections (i.e., without SSL/TLS unlike its TCP counterpart),
362           # and uses it as the primary channel. That option is experimental
363           # and it has many known issues.
364           #  * It can only be combined with certificate authentication, when receiving
365           #    channel information through proxy protocol (see listen-proxy-proto)
366           #  * It cannot derive any keys needed for the DTLS session (hence no support for dtls-psk)
367           #  * It cannot enforce the framing of the SSL/TLS packets, and that
368           #    breaks assumptions held by several openconnect clients.
369           # This option is not recommended for use, and may be removed
370           # in the future.
371           #
372           #listen-clear-file = /var/run/ocserv-conn.socket
373
374           # The user the worker processes will be run as. This should be a dedicated
375           # unprivileged user (e.g., ´ocserv´) and no other services should run as this
376           # user.
377           run-as-user = nobody
378           run-as-group = daemon
379
380           # socket file used for IPC with occtl. You only need to set that,
381           # if you use more than a single servers.
382           #occtl-socket-file = /var/run/occtl.socket
383
384           # socket file used for server IPC (worker-main), will be appended with .PID
385           # It must be accessible within the chroot environment (if any), so it is best
386           # specified relatively to the chroot directory.
387           socket-file = /var/run/ocserv-socket
388
389           # The default server directory. Does not require any devices present.
390           #chroot-dir = /var/lib/ocserv
391
392           # The key and the certificates of the server
393           # The key may be a file, or any URL supported by GnuTLS (e.g.,
394           # tpmkey:uuid=xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxx;storage=user
395           # or pkcs11:object=my-vpn-key;object-type=private)
396           #
397           # The server-cert file may contain a single certificate, or
398           # a sorted certificate chain.
399           # There may be multiple server-cert and server-key directives,
400           # but each key should correspond to the preceding certificate.
401           # The certificate files will be reloaded when changed allowing for in-place
402           # certificate renewal (they are checked and reloaded periodically;
403           # a SIGHUP signal to main server will force reload).
404
405           #server-cert = /etc/ocserv/server-cert.pem
406           #server-key = /etc/ocserv/server-key.pem
407           server-cert = ../tests/certs/server-cert.pem
408           server-key = ../tests/certs/server-key.pem
409
410           # Diffie-Hellman parameters. Only needed if for old (pre 3.6.0
411           # versions of GnuTLS for supporting DHE ciphersuites.
412           # Can be generated using:
413           # certtool --generate-dh-params --outfile /etc/ocserv/dh.pem
414           #dh-params = /etc/ocserv/dh.pem
415
416           # In case PKCS #11, TPM or encrypted keys are used the PINs should be available
417           # in files. The srk-pin-file is applicable to TPM keys only, and is the
418           # storage root key.
419           #pin-file = /etc/ocserv/pin.txt
420           #srk-pin-file = /etc/ocserv/srkpin.txt
421
422           # The password or PIN needed to unlock the key in server-key file.
423           # Only needed if the file is encrypted or a PKCS #11 object. This
424           # is an alternative method to pin-file.
425           #key-pin = 1234
426
427           # The SRK PIN for TPM.
428           # This is an alternative method to srk-pin-file.
429           #srk-pin = 1234
430
431           # The Certificate Authority that will be used to verify
432           # client certificates (public keys) if certificate authentication
433           # is set.
434           #ca-cert = /etc/ocserv/ca.pem
435           ca-cert = ../tests/certs/ca.pem
436
437
438           ### All configuration options below this line are reloaded on a SIGHUP.
439           ### The options above, will remain unchanged. Note however, that the
440           ### server-cert, server-key, dh-params and ca-cert options will be reloaded
441           ### if the provided file changes, on server reload. That allows certificate
442           ### rotation, but requires the server key to remain the same for seamless
443           ### operation. If the server key changes on reload, there may be connection
444           ### failures during the reloading time.
445
446
447           # Whether to enable seccomp/Linux namespaces worker isolation. That restricts the number of
448           # system calls allowed to a worker process, in order to reduce damage from a
449           # bug in the worker process. It is available on Linux systems at a performance cost.
450           # The performance cost is roughly 2% overhead at transfer time (tested on a Linux 3.17.8).
451           # Note however, that process isolation is restricted to the specific libc versions
452           # the isolation was tested at. If you get random failures on worker processes, try
453           # disabling that option and report the failures you, along with system and debugging
454           # information at: https://gitlab.com/ocserv/ocserv/issues
455           isolate-workers = true
456
457           # A banner to be displayed on clients after connection
458           #banner = "Welcome"
459
460           # A banner to be displayed on clients before connection
461           #pre-login-banner = "Welcome"
462
463           # Limit the number of clients. Unset or set to zero for unlimited.
464           #max-clients = 1024
465           max-clients = 16
466
467           # Limit the number of identical clients (i.e., users connecting
468           # multiple times). Unset or set to zero for unlimited.
469           max-same-clients = 2
470
471           # When the server receives connections from a proxy, like haproxy
472           # which supports the proxy protocol, set this to obtain the correct
473           # client addresses. The proxy protocol would then be expected in
474           # the TCP or UNIX socket (not the UDP one). Although both v1
475           # and v2 versions of proxy protocol are supported, the v2 version
476           # is recommended as it is more efficient in parsing.
477           #listen-proxy-proto = true
478
479           # Rate limit the number of incoming connections to one every X milliseconds
480           # (X is the provided value), as the secmod backlog grows. This
481           # makes the server more resilient (and prevents connection failures) on
482           # multiple concurrent connections. Set to zero for no limit.
483           rate-limit-ms = 100
484
485           # Stats report time. The number of seconds after which each
486           # worker process will report its usage statistics (number of
487           # bytes transferred etc). This is useful when accounting like
488           # radius is in use.
489           #stats-report-time = 360
490
491           # Stats reset time. The period of time statistics kept by main/sec-mod
492           # processes will be reset. These are the statistics shown by cmd
493           # ´occtl show stats´. For daily: 86400, weekly: 604800
494           # This is unrelated to stats-report-time.
495           server-stats-reset-time = 604800
496
497           # Keepalive in seconds
498           keepalive = 32400
499
500           # Dead peer detection in seconds.
501           # Note that when the client is behind a NAT this value
502           # needs to be short enough to prevent the NAT disassociating
503           # his UDP session from the port number. Otherwise the client
504           # could have his UDP connection stalled, for several minutes.
505           dpd = 90
506
507           # Dead peer detection for mobile clients. That needs to
508           # be higher to prevent such clients being awaken too
509           # often by the DPD messages, and save battery.
510           # The mobile clients are distinguished from the header
511           # ´X-AnyConnect-Identifier-Platform´.
512           mobile-dpd = 1800
513
514           # If using DTLS, and no UDP traffic is received for this
515           # many seconds, attempt to send future traffic over the TCP
516           # connection instead, in an attempt to wake up the client
517           # in the case that there is a NAT and the UDP translation
518           # was deleted. If this is unset, do not attempt to use this
519           # recovery mechanism.
520           switch-to-tcp-timeout = 25
521
522           # MTU discovery (DPD must be enabled)
523           try-mtu-discovery = false
524
525           # If you have a certificate from a CA that provides an OCSP
526           # service you may provide a fresh OCSP status response within
527           # the TLS handshake. That will prevent the client from connecting
528           # independently on the OCSP server.
529           # You can update this response periodically using:
530           # ocsptool --ask --load-cert=your_cert --load-issuer=your_ca --outfile response
531           # Make sure that you replace the following file in an atomic way.
532           #ocsp-response = /etc/ocserv/ocsp.der
533
534           # The object identifier that will be used to read the user ID in the client
535           # certificate. The object identifier should be part of the certificate´s DN
536           # Useful OIDs are:
537           #  CN = 2.5.4.3, UID = 0.9.2342.19200300.100.1.1, SAN(rfc822name)
538           cert-user-oid = 0.9.2342.19200300.100.1.1
539
540           # The object identifier that will be used to read the user group in the
541           # client certificate. The object identifier should be part of the certificate´s
542           # DN. If the user may belong to multiple groups, then use multiple such fields
543           # in the certificate´s DN. Useful OIDs are:
544           #  OU (organizational unit) = 2.5.4.11
545           #cert-group-oid = 2.5.4.11
546
547           # The revocation list of the certificates issued by the ´ca-cert´ above.
548           # See the manual to generate an empty CRL initially. The CRL will be reloaded
549           # periodically when ocserv detects a change in the file. To force a reload use
550           # SIGHUP.
551           #crl = /etc/ocserv/crl.pem
552
553           # Uncomment this to enable compression negotiation (LZS, LZ4).
554           #compression = true
555
556           # Set the minimum size under which a packet will not be compressed.
557           # That is to allow low-latency for VoIP packets. The default size
558           # is 256 bytes. Modify it if the clients typically use compression
559           # as well of VoIP with codecs that exceed the default value.
560           #no-compress-limit = 256
561
562           # GnuTLS priority string; note that SSL 3.0 is disabled by default
563           # as there are no openconnect (and possibly anyconnect clients) using
564           # that protocol. The string below does not enforce perfect forward
565           # secrecy, in order to be compatible with legacy clients.
566           #
567           # Note that the most performant ciphersuites are the moment are the ones
568           # involving AES-GCM. These are very fast in x86 and x86-64 hardware, and
569           # in addition require no padding, thus taking full advantage of the MTU.
570           # For that to be taken advantage of, the openconnect client must be
571           # used, and the server must be compiled against GnuTLS 3.2.7 or later.
572           # Use "gnutls-cli --benchmark-tls-ciphers", to see the performance
573           # difference with AES_128_CBC_SHA1 (the default for anyconnect clients)
574           # in your system.
575
576           tls-priorities = "NORMAL:%SERVER_PRECEDENCE:%COMPAT:-VERS-SSL3.0:-VERS-TLS1.0:-VERS-TLS1.1"
577
578           # More combinations in priority strings are available, check
579           # http://gnutls.org/manual/html_node/Priority-Strings.html
580           # E.g., the string below enforces perfect forward secrecy (PFS)
581           # on the main channel.
582           #tls-priorities = "NORMAL:%SERVER_PRECEDENCE:%COMPAT:-RSA:-VERS-SSL3.0:-ARCFOUR-128"
583
584           # That option requires the established DTLS channel to use the same
585           # cipher as the primary TLS channel. This cannot be combined with
586           # listen-clear-file since the ciphersuite information is not available
587           # in that configuration. Note also, that this option implies that
588           # dtls-legacy option is false; this option cannot be enforced
589           # in the legacy/compat protocol.
590           #match-tls-dtls-ciphers = true
591
592           # The time (in seconds) that a client is allowed to stay connected prior
593           # to authentication
594           auth-timeout = 240
595
596           # The time (in seconds) that a client is allowed to stay idle (no traffic)
597           # before being disconnected. Unset to disable.
598           #idle-timeout = 1200
599
600           # The time (in seconds) that a client is allowed to stay connected
601           # Unset to disable. When set a client will be disconnected after being
602           # continuously connected for this amount of time, and its cookies will
603           # be invalidated (i.e., re-authentication will be required).
604           #session-timeout = 86400
605
606           # The time (in seconds) that a mobile client is allowed to stay idle (no
607           # traffic) before being disconnected. Unset to disable.
608           #mobile-idle-timeout = 2400
609
610           # The time (in seconds) that a client is not allowed to reconnect after
611           # a failed authentication attempt.
612           min-reauth-time = 300
613
614           # Banning clients in ocserv works with a point system. IP addresses
615           # that get a score over that configured number are banned for
616           # min-reauth-time seconds. By default a wrong password attempt is 10 points,
617           # a KKDCP POST is 1 point, and a connection is 1 point. Note that
618           # due to difference processes being involved the count of points
619           # will not be real-time precise.
620           #
621           # Score banning cannot be reliably used when receiving proxied connections
622           # locally from an HTTP server (i.e., when listen-clear-file is used).
623           #
624           # Set to zero to disable.
625           max-ban-score = 80
626
627           # The time (in seconds) that all score kept for a client is reset.
628           ban-reset-time = 1200
629
630           # In case you´d like to change the default points.
631           #ban-points-wrong-password = 10
632           #ban-points-connection = 1
633           #ban-points-kkdcp = 1
634
635           # Cookie timeout (in seconds)
636           # Once a client is authenticated he´s provided a cookie with
637           # which he can reconnect. That cookie will be invalidated if not
638           # used within this timeout value. This cookie remains valid, during
639           # the user´s connected time, and after user disconnection it
640           # remains active for this amount of time. That setting should allow a
641           # reasonable amount of time for roaming between different networks.
642           cookie-timeout = 300
643
644           # If this is enabled (not recommended) the cookies will stay
645           # valid even after a user manually disconnects, and until they
646           # expire. This may improve roaming with some broken clients.
647           #persistent-cookies = true
648
649           # Whether roaming is allowed, i.e., if true a cookie is
650           # restricted to a single IP address and cannot be re-used
651           # from a different IP.
652           deny-roaming = false
653
654           # ReKey time (in seconds)
655           # ocserv will ask the client to refresh keys periodically once
656           # this amount of seconds is elapsed. Set to zero to disable (note
657           # that, some clients fail if rekey is disabled).
658           rekey-time = 172800
659
660           # ReKey method
661           # Valid options: ssl, new-tunnel
662           #  ssl: Will perform an efficient rehandshake on the channel allowing
663           #       a seamless connection during rekey.
664           #  new-tunnel: Will instruct the client to discard and re-establish the channel.
665           #       Use this option only if the connecting clients have issues with the ssl
666           #       option.
667           rekey-method = ssl
668
669           # Script to call when a client connects and obtains an IP.
670           # The following parameters are passed on the environment.
671           # REASON, VHOST, USERNAME, GROUPNAME, DEVICE, IP_REAL (the real IP of the client),
672           # REMOTE_HOSTNAME (the remotely advertised hostname), IP_REAL_LOCAL
673           # (the local interface IP the client connected), IP_LOCAL
674           # (the local IP in the P-t-P connection), IP_REMOTE (the VPN IP of the client),
675           # IPV6_LOCAL (the IPv6 local address if there are both IPv4 and IPv6
676           # assigned), IPV6_REMOTE (the IPv6 remote address), IPV6_PREFIX, and
677           # ID (a unique numeric ID); REASON may be "connect" or "disconnect".
678           # In addition the following variables OCSERV_ROUTES (the applied routes for this
679           # client), OCSERV_NO_ROUTES, OCSERV_DNS (the DNS servers for this client),
680           # will contain a space separated list of routes or DNS servers. A version
681           # of these variables with the 4 or 6 suffix will contain only the IPv4 or
682           # IPv6 values. The connect script must return zero as exit code, or the
683           # client connection will be refused.
684
685           # The disconnect script will receive the additional values: STATS_BYTES_IN,
686           # STATS_BYTES_OUT, STATS_DURATION that contain a 64-bit counter of the bytes
687           # output from the tun device, and the duration of the session in seconds.
688
689           #connect-script = /usr/bin/myscript
690           #disconnect-script = /usr/bin/myscript
691
692           # This script is to be called when the client´s advertised hostname becomes
693           # available. It will contain REASON with "host-update" value and the
694           # variable REMOTE_HOSTNAME in addition to the connect variables.
695
696           #host-update-script = /usr/bin/myhostnamescript
697
698           # UTMP
699           # Register the connected clients to utmp. This will allow viewing
700           # the connected clients using the command ´who´.
701           #use-utmp = true
702
703           # Whether to enable support for the occtl tool (i.e., either through D-BUS,
704           # or via a unix socket).
705           use-occtl = true
706
707           # PID file. It can be overridden in the command line.
708           pid-file = /var/run/ocserv.pid
709
710           # Set the protocol-defined priority (SO_PRIORITY) for packets to
711           # be sent. That is a number from 0 to 6 with 0 being the lowest
712           # priority. Alternatively this can be used to set the IP Type-
713           # Of-Service, by setting it to a hexadecimal number (e.g., 0x20).
714           # This can be set per user/group or globally.
715           #net-priority = 3
716
717           # Set the VPN worker process into a specific cgroup. This is Linux
718           # specific and can be set per user/group or globally.
719           #cgroup = "cpuset,cpu:test"
720
721           #
722           # Network settings
723           #
724
725           # The name to use for the tun device
726           device = vpns
727
728           # Whether the generated IPs will be predictable, i.e., IP stays the
729           # same for the same user when possible.
730           predictable-ips = true
731
732           # The default domain to be advertised. Multiple domains (functional on
733           # openconnect clients) can be provided in a space separated list.
734           default-domain = example.com
735           #default-domain = "example.com one.example.com"
736
737           # The pool of addresses that leases will be given from. If the leases
738           # are given via Radius, or via the explicit-ip? per-user config option then
739           # these network values should contain a network with at least a single
740           # address that will remain under the full control of ocserv (that is
741           # to be able to assign the local part of the tun device address).
742           # Note that, you could use addresses from a subnet of your LAN network if you
743           # enable [proxy arp in the LAN interface](http://ocserv.gitlab.io/www/recipes-ocserv-pseudo-bridge.html);
744           # in that case it is recommended to set ping-leases to true.
745           ipv4-network = 192.168.1.0
746           ipv4-netmask = 255.255.255.0
747
748           # An alternative way of specifying the network:
749           #ipv4-network = 192.168.1.0/24
750
751           # The IPv6 subnet that leases will be given from.
752           #ipv6-network = fda9:4efe:7e3b:03ea::/48
753
754           # Specify the size of the network to provide to clients. It is
755           # generally recommended to provide clients with a /64 network in
756           # IPv6, but any subnet may be specified. To provide clients only
757           # with a single IP use the prefix 128.
758           #ipv6-subnet-prefix = 128
759           #ipv6-subnet-prefix = 64
760
761           # Whether to tunnel all DNS queries via the VPN. This is the default
762           # when a default route is set.
763           #tunnel-all-dns = true
764
765           # The advertized DNS server. Use multiple lines for
766           # multiple servers.
767           # dns = fc00::4be0
768           dns = 192.168.1.2
769
770           # The NBNS server (if any)
771           #nbns = 192.168.1.3
772
773           # The domains over which the provided DNS should be used. Use
774           # multiple lines for multiple domains.
775           #split-dns = example.com
776
777           # Prior to leasing any IP from the pool ping it to verify that
778           # it is not in use by another (unrelated to this server) host.
779           # Only set to true, if there can be occupied addresses in the
780           # IP range for leases.
781           ping-leases = false
782
783           # Use this option to set a link MTU value to the incoming
784           # connections. Unset to use the default MTU of the TUN device.
785           # Note that the MTU is negotiated using the value set and the
786           # value sent by the peer.
787           #mtu = 1420
788
789           # Unset to enable bandwidth restrictions (in bytes/sec). The
790           # setting here is global, but can also be set per user or per group.
791           #rx-data-per-sec = 40000
792           #tx-data-per-sec = 40000
793
794           # The number of packets (of MTU size) that are available in
795           # the output buffer. The default is low to improve latency.
796           # Setting it higher will improve throughput.
797           #output-buffer = 10
798
799           # Routes to be forwarded to the client. If you need the
800           # client to forward routes to the server, you may use the
801           # config-per-user/group or even connect and disconnect scripts.
802           #
803           # To set the server as the default gateway for the client just
804           # comment out all routes from the server, or use the special keyword
805           # ´default´.
806
807           route = 10.10.10.0/255.255.255.0
808           route = 192.168.0.0/255.255.0.0
809           #route = fef4:db8:1000:1001::/64
810           #route = default
811
812           # Subsets of the routes above that will not be routed by
813           # the server.
814
815           no-route = 192.168.5.0/255.255.255.0
816
817           # Note the that following two firewalling options currently are available
818           # in Linux systems with iptables software.
819
820           # If set, the script /usr/bin/ocserv-fw will be called to restrict
821           # the user to its allowed routes and prevent him from accessing
822           # any other routes. In case of defaultroute, the no-routes are restricted.
823           # All the routes applied by ocserv can be reverted using /usr/bin/ocserv-fw
824           # --removeall. This option can be set globally or in the per-user configuration.
825           #restrict-user-to-routes = true
826
827           # This option implies restrict-user-to-routes set to true. If set, the
828           # script /usr/bin/ocserv-fw will be called to restrict the user to
829           # access specific ports in the network. This option can be set globally
830           # or in the per-user configuration.
831           #restrict-user-to-ports = "tcp(443), tcp(80), udp(443), sctp(99), tcp(583), icmp(), icmpv6()"
832
833           # You could also use negation, i.e., block the user from accessing these ports only.
834           #restrict-user-to-ports = "!(tcp(443), tcp(80))"
835
836           # When set to true, all client´s iroutes are made visible to all
837           # connecting clients except for the ones offering them. This option
838           # only makes sense if config-per-user is set.
839           #expose-iroutes = true
840
841           # Groups that a client is allowed to select from.
842           # A client may belong in multiple groups, and in certain use-cases
843           # it is needed to switch between them. For these cases the client can
844           # select prior to authentication. Add multiple entries for multiple groups.
845           # The group may be followed by a user-friendly name in brackets.
846           #select-group = group1
847           #select-group = group2[My special group]
848
849           # The name of the (virtual) group that if selected it would assign the user
850           # to its default group.
851           #default-select-group = DEFAULT
852
853           # Instead of specifying manually all the allowed groups, you may instruct
854           # ocserv to scan all available groups and include the full list.
855           #auto-select-group = true
856
857           # Configuration files that will be applied per user connection or
858           # per group. Each file name on these directories must match the username
859           # or the groupname.
860           # The options allowed in the configuration files are dns, nbns,
861           #  ipv?-network, ipv4-netmask, rx/tx-data-per-sec, iroute, route, no-route,
862           #  explicit-ipv4, explicit-ipv6, net-priority, deny-roaming, no-udp,
863           #  keepalive, dpd, mobile-dpd, max-same-clients, tunnel-all-dns,
864           #  restrict-user-to-routes, cgroup, stats-report-time,
865           #  mtu, idle-timeout, mobile-idle-timeout, restrict-user-to-ports,
866           #  split-dns and session-timeout.
867           #
868           # Note that the ´iroute´ option allows one to add routes on the server
869           # based on a user or group. The syntax depends on the input accepted
870           # by the commands route-add-cmd and route-del-cmd (see below). The no-udp
871           # is a boolean option (e.g., no-udp = true), and will prevent a UDP session
872           # for that specific user or group. The hostname option will set a
873           # hostname to override any proposed by the user. Note also, that, any
874           # routes, no-routes, DNS or NBNS servers present will overwrite the global ones.
875
876           #config-per-user = /etc/ocserv/config-per-user/
877           #config-per-group = /etc/ocserv/config-per-group/
878
879           # When config-per-xxx is specified and there is no group or user that
880           # matches, then utilize the following configuration.
881           #default-user-config = /etc/ocserv/defaults/user.conf
882           #default-group-config = /etc/ocserv/defaults/group.conf
883
884           # The system command to use to setup a route. %{R} will be replaced with the
885           # route/mask, %{RI} with the route in CIDR format, and %{D} with the (tun) device.
886           #
887           # The following example is from linux systems. %{R} should be something
888           # like 192.168.2.0/255.255.255.0 and %{RI} 192.168.2.0/24 (the argument of iroute).
889
890           #route-add-cmd = "ip route add %{R} dev %{D}"
891           #route-del-cmd = "ip route delete %{R} dev %{D}"
892
893           # This option allows one to forward a proxy. The special keywords ´%{U}´
894           # and ´%{G}´, if present will be replaced by the username and group name.
895           #proxy-url = http://example.com/
896           #proxy-url = http://example.com/%{U}/
897
898           # This option allows you to specify a URL location where a client can
899           # post using MS-KKDCP, and the message will be forwarded to the provided
900           # KDC server. That is a translation URL between HTTP and Kerberos.
901           # In MIT kerberos you´ll need to add in realms:
902           #   EXAMPLE.COM = {
903           #     kdc = https://ocserv.example.com/KdcProxy
904           #     http_anchors = FILE:/etc/ocserv-ca.pem
905           #   }
906           # In some distributions the krb5-k5tls plugin of kinit is required.
907           #
908           # The following option is available in ocserv, when compiled with GSSAPI support.
909
910           #kkdcp = "SERVER-PATH KERBEROS-REALM PROTOCOL@SERVER:PORT"
911           #kkdcp = "/KdcProxy KERBEROS.REALM udp@127.0.0.1:88"
912           #kkdcp = "/KdcProxy KERBEROS.REALM tcp@127.0.0.1:88"
913           #kkdcp = "/KdcProxy KERBEROS.REALM tcp@[::1]:88"
914
915           # Client profile xml. This can be used to advertise alternative servers
916           # to the client. A minimal file can be:
917           # <?xml version="1.0" encoding="UTF-8"?>
918           # <AnyConnectProfile xmlns="http://schemas.xmlsoap.org/encoding/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://schemas.xmlsoap.org/encoding/ AnyConnectProfile.xsd">
919           #   <ServerList>
920           #       <HostEntry>
921           #               <HostName>VPN Server name</HostName>
922           #               <HostAddress>localhost</HostAddress>
923           #       </HostEntry>
924           #   </ServerList>
925           # </AnyConnectProfile>
926           #
927           # Other fields may be used by some of the CISCO clients.
928           # This file must be accessible from inside the worker´s chroot.
929           # Note that:
930           #  (1) enabling this option is not recommended as it will allow the
931           #      worker processes to open arbitrary files (when isolate-workers is
932           #      set to true).
933           #  (2) This option cannot be set per-user or per-group; only the global
934           #      version is being sent to client.
935           #user-profile = profile.xml
936
937           #
938           # The following options are for (experimental) AnyConnect client
939           # compatibility.
940
941           # This option will enable the pre-draft-DTLS version of DTLS, and
942           # will not require clients to present their certificate on every TLS
943           # connection. It must be set to true to support legacy CISCO clients
944           # and openconnect clients < 7.08. When set to true, it implies dtls-legacy = true.
945           cisco-client-compat = true
946
947           # This option allows one to disable the DTLS-PSK negotiation (enabled by default).
948           # The DTLS-PSK negotiation was introduced in ocserv 0.11.5 to deprecate
949           # the pre-draft-DTLS negotiation inherited from AnyConnect. It allows the
950           # DTLS channel to negotiate its ciphers and the DTLS protocol version.
951           #dtls-psk = false
952
953           # This option allows one to disable the legacy DTLS negotiation (enabled by default,
954           # but that may change in the future).
955           # The legacy DTLS uses a pre-draft version of the DTLS protocol and was
956           # from AnyConnect protocol. It has several limitations, that are addressed
957           # by the dtls-psk protocol supported by openconnect 7.08+.
958           dtls-legacy = true
959
960           #Advanced options
961
962           # Option to allow sending arbitrary custom headers to the client after
963           # authentication and prior to VPN tunnel establishment. You shouldn´t
964           # need to use this option normally; if you do and you think that
965           # this may help others, please send your settings and reason to
966           # the openconnect mailing list. The special keywords ´%{U}´
967           # and ´%{G}´, if present will be replaced by the username and group name.
968           #custom-header = "X-My-Header: hi there"
969
970
971
972           # An example virtual host with different authentication methods serviced
973           # by this server.
974
975           [vhost:www.example.com]
976           auth = "certificate"
977
978           ca-cert = ../tests/certs/ca.pem
979
980           # The certificate set here must include a ´dns_name´ corresponding to
981           # the virtual host name.
982
983           server-cert = ../tests/certs/server-cert-secp521r1.pem
984           server-key = ../tests/certs/server-key-secp521r1.pem
985
986           ipv4-network = 192.168.2.0
987           ipv4-netmask = 255.255.255.0
988
989           cert-user-oid = 0.9.2342.19200300.100.1.1
990
991           # To enable load-balancer connection draining, set server-drain-ms to a value
992           # higher than your load-balancer health probe interval.
993           # server-drain-ms = 15000
994
995
996

SEE ALSO

998       occtl(8), ocpasswd(8), openconnect(8)
999
1001       Copyright (C) 2013-2018 Nikos Mavrogiannopoulos and others, all  rights
1002       reserved.  This  program is released under the terms of the GNU General
1003       Public License, version 2.
1004

AUTHORS

1006       Written by Nikos Mavrogiannopoulos. Many people have contributed to it.
1007
1008
1009
1010                                September 2020                       OCSERV(8)
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