Provided by: libstrongswan_5.6.2-1ubuntu2.9_amd64 bug

NAME

       strongswan.conf - strongSwan configuration file

DESCRIPTION

       While  the  ipsec.conf(5)  configuration  file  is  well  suited  to  define  IPsec related configuration
       parameters, it is not useful for other strongSwan applications to read options from this file.  The  file
       is  hard  to  parse  and  only  ipsec  starter is capable of doing so. As the number of components of the
       strongSwan project is continually growing, a more flexible configuration file was  needed,  one  that  is
       easy to extend and can be used by all components. With strongSwan 4.2.1 strongswan.conf(5) was introduced
       which meets these requirements.

SYNTAX

       The format of the strongswan.conf file consists of hierarchical sections and a list of key/value pairs in
       each section. Each section has a name, followed by C-Style curly brackets defining the section body. Each
       section body contains a set of subsections and key/value pairs:

            settings := (section|keyvalue)*
            section  := name { settings }
            keyvalue := key = value\n

       Values must be terminated by a newline.

       Comments  are  possible  using  the  #-character,  but be careful: The parser implementation is currently
       limited and does not like brackets in comments.

       Section names and keys may contain any printable character except:

            . { } # \n \t space

       An example file in this format might look like this:

            a = b
            section-one {
                 somevalue = asdf
                 subsection {
                      othervalue = xxx
                 }
                 # yei, a comment
                 yetanother = zz
            }
            section-two {
                 x = 12
            }

       Indentation is optional, you may use tabs or spaces.

INCLUDING FILES

       Using the include statement it is possible to include other files into strongswan.conf, e.g.

            include /some/path/*.conf

       If the file name is not an absolute path, it is considered to be relative to the directory  of  the  file
       containing  the  include  statement.  The  file name may include shell wildcards (see sh(1)).  Also, such
       inclusions can be nested.

       Sections loaded from included files extend  previously  loaded  sections;  already  existing  values  are
       replaced.   It is important to note that settings are added relative to the section the include statement
       is in.

       As an example, the following three files result in the same final config as the one given above:

            a = b
            section-one {
                 somevalue = before include
                 include include.conf
            }
            include other.conf

       include.conf:
            # settings loaded from this file are added to section-one
            # the following replaces the previous value
            somevalue = asdf
            subsection {
                 othervalue = yyy
            }
            yetanother = zz

       other.conf:
            # this extends section-one and subsection
            section-one {
                 subsection {
                      # this replaces the previous value
                      othervalue = xxx
                 }
            }
            section-two {
                 x = 12
            }

READING VALUES

       Values are accessed using a dot-separated section list and a key.  With reference to the  example  above,
       accessing section-one.subsection.othervalue will return xxx.

DEFINED KEYS

       The  following  keys  are currently defined (using dot notation). The default value (if any) is listed in
       brackets after the key.

       aikgen.load []
              Plugins to load in ipsec aikgen tool.

       attest.database []
              File measurement information database URI. If it contains a password,  make  sure  to  adjust  the
              permissions of the config file accordingly.

       attest.load []
              Plugins to load in ipsec attest tool.

       charon
              Options for the charon IKE daemon.

              Note:  Many  of the options in this section also apply to charon-cmd and other charon derivatives.
              Just use their respective name (e.g.  charon-cmd instead of charon).  For  many  options  defaults
              can be defined in the libstrongswan section.

       charon.accept_unencrypted_mainmode_messages [no]
              Accept unencrypted ID and HASH payloads in IKEv1 Main Mode.

              Some  implementations  send the third Main Mode message unencrypted, probably to find the PSKs for
              the specified ID for authentication. This is very similar to Aggressive Mode,  and  has  the  same
              security  implications:  A  passive  attacker  can  sniff the negotiated Identity, and start brute
              forcing the PSK using the HASH payload.

              It is recommended to keep this option to no, unless you know exactly what the implications are and
              require compatibility to such devices (for example, some SonicWall boxes).

       charon.block_threshold [5]
              Maximum number of half-open IKE_SAs for a single peer IP.

       charon.cache_crls [no]
              Whether Certificate Revocation Lists (CRLs) fetched via HTTP or  LDAP  should  be  saved  under  a
              unique   file   name  derived  from  the  public  key  of  the  Certification  Authority  (CA)  to
              /etc/ipsec.d/crls (stroke) or /etc/swanctl/x509crl (vici), respectively.

       charon.cert_cache [yes]
              Whether relations in validated certificate chains should be cached in memory.

       charon.cisco_unity [no]
              Send Cisco Unity vendor ID payload (IKEv1 only).

       charon.close_ike_on_child_failure [no]
              Close the IKE_SA if setup of the CHILD_SA along with IKE_AUTH failed.

       charon.cookie_threshold [10]
              Number of half-open IKE_SAs that activate the cookie mechanism.

       charon.crypto_test.bench [no]
              Benchmark crypto algorithms and order them by efficiency.

       charon.crypto_test.bench_size [1024]
              Buffer size used for crypto benchmark.

       charon.crypto_test.bench_time [50]
              Number of iterations to test each algorithm.

       charon.crypto_test.on_add [no]
              Test crypto algorithms during registration (requires test vectors  provided  by  the  test-vectors
              plugin).

       charon.crypto_test.on_create [no]
              Test crypto algorithms on each crypto primitive instantiation.

       charon.crypto_test.required [no]
              Strictly require at least one test vector to enable an algorithm.

       charon.crypto_test.rng_true [no]
              Whether to test RNG with TRUE quality; requires a lot of entropy.

       charon.delete_rekeyed [no]
              Delete  CHILD_SAs  right  after  they got successfully rekeyed (IKEv1 only). Reduces the number of
              stale CHILD_SAs in scenarios with a lot of rekeyings. However,  this  might  cause  problems  with
              implementations that continue to use rekeyed SAs until they expire.

       charon.delete_rekeyed_delay [5]
              Delay  in  seconds  until  inbound  IPsec SAs are deleted after rekeyings (IKEv2 only). To process
              delayed packets the inbound part of a CHILD_SA is kept installed up to the  configured  number  of
              seconds  after  it got replaced during a rekeying. If set to 0 the CHILD_SA will be kept installed
              until it expires (if no lifetime is set it will be destroyed immediately).

       charon.dh_exponent_ansi_x9_42 [yes]
              Use ANSI X9.42 DH exponent size or optimum size matched to cryptographic strength.

       charon.dlopen_use_rtld_now [no]
              Use RTLD_NOW with dlopen when loading plugins and IMV/IMCs to reveal missing symbols immediately.

       charon.dns1 []
              DNS server assigned to peer via configuration payload (CP).

       charon.dns2 []
              DNS server assigned to peer via configuration payload (CP).

       charon.dos_protection [yes]
              Enable Denial of Service protection using cookies and aggressiveness checks.

       charon.ecp_x_coordinate_only [yes]
              Compliance with the errata for RFC 4753.

       charon.filelog
              Section to define file loggers, see LOGGER CONFIGURATION in strongswan.conf(5).

       charon.filelog.<filename>
              <filename> is the full path to the log file.

       charon.filelog.<filename>.<subsystem> [<default>]
              Loglevel for a specific subsystem.

       charon.filelog.<filename>.append [yes]
              If this option is enabled log entries are appended to the existing file.

       charon.filelog.<filename>.default [1]
              Specifies the default loglevel to be used  for  subsystems  for  which  no  specific  loglevel  is
              defined.

       charon.filelog.<filename>.flush_line [no]
              Enabling this option disables block buffering and enables line buffering.

       charon.filelog.<filename>.ike_name [no]
              Prefix each log entry with the connection name and a unique numerical identifier for each IKE_SA.

       charon.filelog.<filename>.time_add_ms [no]
              Adds  the  milliseconds  within  the  current  second  after the timestamp (separated by a dot, so
              time_format should end with %S or %T).

       charon.filelog.<filename>.time_format []
              Prefix each log entry with  a  timestamp.  The  option  accepts  a  format  string  as  passed  to
              strftime(3).

       charon.flush_auth_cfg [no]
              If  enabled  objects  used  during authentication (certificates, identities etc.)  are released to
              free memory once an IKE_SA is established. Enabling this might conflict with  plugins  that  later
              need access to e.g. the used certificates.

       charon.follow_redirects [yes]
              Whether to follow IKEv2 redirects (RFC 5685).

       charon.fragment_size [1280]
              Maximum  size  (complete  IP datagram size in bytes) of a sent IKE fragment when using proprietary
              IKEv1 or standardized IKEv2 fragmentation, defaults to 1280 (use 0  for  address  family  specific
              default values, which uses a lower value for IPv4).  If specified this limit is used for both IPv4
              and IPv6.

       charon.group []
              Name of the group the daemon changes to after startup.

       charon.half_open_timeout [30]
              Timeout in seconds for connecting IKE_SAs (also see IKE_SA_INIT DROPPING).

       charon.hash_and_url [no]
              Enable hash and URL support.

       charon.host_resolver.max_threads [3]
              Maximum number of concurrent resolver threads (they are terminated if unused).

       charon.host_resolver.min_threads [0]
              Minimum number of resolver threads to keep around.

       charon.i_dont_care_about_security_and_use_aggressive_mode_psk [no]
              If  enabled  responders  are  allowed  to use IKEv1 Aggressive Mode with pre-shared keys, which is
              discouraged due to security concerns (offline attacks on the openly transmitted hash of the PSK).

       charon.ignore_acquire_ts [no]
              If this is disabled the traffic selectors from the kernel's acquire events, which are derived from
              the triggering packet, are prepended to the traffic selectors from  the  configuration  for  IKEv2
              connection. By enabling this, such specific traffic selectors will be ignored and only the ones in
              the  config  will be sent. This always happens for IKEv1 connections as the protocol only supports
              one set of traffic selectors per CHILD_SA.

       charon.ignore_routing_tables []
              A space-separated list of routing tables to be excluded from route lookups.

       charon.ikesa_limit [0]
              Maximum number of IKE_SAs that can be established at the same time before new connection  attempts
              are blocked.

       charon.ikesa_table_segments [1]
              Number of exclusively locked segments in the hash table.

       charon.ikesa_table_size [1]
              Size of the IKE_SA hash table.

       charon.imcv
              Defaults for options in this section can be configured in the libimcv section.

       charon.imcv.assessment_result [yes]
              Whether IMVs send a standard IETF Assessment Result attribute.

       charon.imcv.database []
              Global  IMV policy database URI. If it contains a password, make sure to adjust the permissions of
              the config file accordingly.

       charon.imcv.os_info.default_password_enabled [no]
              Manually set whether a default password is enabled

       charon.imcv.os_info.name []
              Manually set the name of the client OS (e.g. Ubuntu).

       charon.imcv.os_info.version []
              Manually set the version of the client OS (e.g. 12.04 i686).

       charon.imcv.policy_script [ipsec _imv_policy]
              Script called for each TNC connection to generate IMV policies.

       charon.inactivity_close_ike [no]
              Whether to close IKE_SA if the only CHILD_SA closed due to inactivity.

       charon.init_limit_half_open [0]
              Limit new connections based on the current number of half open IKE_SAs, see  IKE_SA_INIT  DROPPING
              in strongswan.conf(5).

       charon.init_limit_job_load [0]
              Limit new connections based on the number of jobs currently queued for processing (see IKE_SA_INIT
              DROPPING).

       charon.initiator_only [no]
              Causes charon daemon to ignore IKE initiation requests.

       charon.install_routes [yes]
              Install routes into a separate routing table for established IPsec tunnels.

       charon.install_virtual_ip [yes]
              Install virtual IP addresses.

       charon.install_virtual_ip_on []
              The  name of the interface on which virtual IP addresses should be installed. If not specified the
              addresses will be installed on the outbound interface.

       charon.integrity_test [no]
              Check daemon, libstrongswan and plugin integrity at startup.

       charon.interfaces_ignore []
              A comma-separated list of  network  interfaces  that  should  be  ignored,  if  interfaces_use  is
              specified this option has no effect.

       charon.interfaces_use []
              A  comma-separated  list of network interfaces that should be used by charon. All other interfaces
              are ignored.

       charon.keep_alive [20s]
              NAT keep alive interval.

       charon.leak_detective.detailed [yes]
              Includes source file names and line numbers in leak detective output.

       charon.leak_detective.usage_threshold [10240]
              Threshold in bytes for leaks to be reported (0 to report all).

       charon.leak_detective.usage_threshold_count [0]
              Threshold in number of allocations for leaks to be reported (0 to report all).

       charon.load []
              Plugins to load in the IKE daemon charon.

       charon.load_modular [no]
              If  enabled,  the  list  of   plugins   to   load   is   determined   via   the   value   of   the
              charon.plugins.<name>.load  options.  In addition to a simple boolean flag that option may take an
              integer value indicating the priority of a plugin, which would influence the order of a plugin  in
              the  plugin  list  (the  default  is  1). If two plugins have the same priority their order in the
              default  plugin  list  is  preserved.  Enabled  plugins  not  found  in  that  list  are   ordered
              alphabetically before other plugins with the same priority.

       charon.make_before_break [no]
              Initiate  IKEv2  reauthentication  with a make-before-break instead of a break-before-make scheme.
              Make-before-break uses overlapping IKE and CHILD_SA during reauthentication  by  first  recreating
              all  new  SAs  before deleting the old ones. This behavior can be beneficial to avoid connectivity
              gaps during reauthentication, but requires support for overlapping SAs by  the  peer.   strongSwan
              can handle such overlapping SAs since version 5.3.0.

       charon.max_ikev1_exchanges [3]
              Maximum number of IKEv1 phase 2 exchanges per IKE_SA to keep state about and track concurrently.

       charon.max_packet [10000]
              Maximum packet size accepted by charon.

       charon.multiple_authentication [yes]
              Enable multiple authentication exchanges (RFC 4739).

       charon.nbns1 []
              WINS servers assigned to peer via configuration payload (CP).

       charon.nbns2 []
              WINS servers assigned to peer via configuration payload (CP).

       charon.plugin.ha.buflen [2048]
              Buffer  size  for  received  HA  messages. For IKEv1 the public DH factors are also transmitted so
              depending on the DH group the HA messages can get quite big (the default  should  be  fine  up  to
              modp4096).

       charon.plugins.addrblock.strict [yes]
              If  set  to  yes,  a  subject certificate without an addrblock extension is rejected if the issuer
              certificate has such an addrblock extension. If set to no, subject certificates issued without the
              addrblock extension are accepted without any traffic selector checks and no policy is enforced  by
              the plugin.

       charon.plugins.android_log.loglevel [1]
              Loglevel for logging to Android specific logger.

       charon.plugins.attr
              Section  to  specify  arbitrary  attributes  that are assigned to a peer via configuration payload
              (CP).

       charon.plugins.attr.<attr> []
              <attr> can be either address, netmask, dns, nbns, dhcp, subnet,  split-include,  split-exclude  or
              the  numeric  identifier  of the attribute type. The assigned value can be an IPv4/IPv6 address, a
              subnet in CIDR notation or an arbitrary value depending on the attribute type.  For some attribute
              types multiple values may be specified as a comma separated list.

       charon.plugins.attr-sql.crash_recovery [yes]
              Release all online leases during startup.  Disable this to  share  the  DB  between  multiple  VPN
              gateways.

       charon.plugins.attr-sql.database []
              Database  URI  for  attr-sql plugin used by charon. If it contains a password, make sure to adjust
              the permissions of the config file accordingly.

       charon.plugins.attr-sql.lease_history [yes]
              Enable logging of SQL IP pool leases.

       charon.plugins.bliss.use_bliss_b [yes]
              Use the enhanced BLISS-B key generation and signature algorithm.

       charon.plugins.bypass-lan.interfaces_ignore []
              A comma-separated list of network interfaces for which connected subnets  should  be  ignored,  if
              interfaces_use is specified this option has no effect.

       charon.plugins.bypass-lan.interfaces_use []
              A comma-separated list of network interfaces for which connected subnets should be considered. All
              other interfaces are ignored.

       charon.plugins.certexpire.csv.cron []
              Cron style string specifying CSV export times.

       charon.plugins.certexpire.csv.empty_string []
              String to use in empty intermediate CA fields.

       charon.plugins.certexpire.csv.fixed_fields [yes]
              Use a fixed intermediate CA field count.

       charon.plugins.certexpire.csv.force [yes]
              Force export of all trustchains we have a private key for.

       charon.plugins.certexpire.csv.format [%d:%m:%Y]
              strftime(3) format string to export expiration dates as.

       charon.plugins.certexpire.csv.local []
              strftime(3) format string for the CSV file name to export local certificates to.

       charon.plugins.certexpire.csv.remote []
              strftime(3) format string for the CSV file name to export remote certificates to.

       charon.plugins.certexpire.csv.separator [,]
              CSV field separator.

       charon.plugins.coupling.file []
              File to store coupling list to.

       charon.plugins.coupling.hash [sha1]
              Hashing algorithm to fingerprint coupled certificates.

       charon.plugins.coupling.max [1]
              Maximum number of coupling entries to create.

       charon.plugins.curl.redir [-1]
              Maximum  number  of redirects followed by the plugin, set to 0 to disable following redirects, set
              to -1 for no limit.

       charon.plugins.dhcp.force_server_address [no]
              Always use the configured server address. This might be helpful if the DHCP  server  runs  on  the
              same  host  as strongSwan, and the DHCP daemon does not listen on the loopback interface.  In that
              case the server cannot be reached via unicast (or even 255.255.255.255) as that  would  be  routed
              via  loopback.  Setting  this  option  to  yes  and  configuring the local broadcast address (e.g.
              192.168.0.255) as server address might work.

       charon.plugins.dhcp.identity_lease [no]
              Derive user-defined MAC address from hash of IKE identity.

       charon.plugins.dhcp.interface []
              Interface name the plugin uses for address allocation. The default is to bind to any (0.0.0.0) and
              let the system decide which way to route the packets to the DHCP server.

       charon.plugins.dhcp.server [255.255.255.255]
              DHCP server unicast or broadcast IP address.

       charon.plugins.dnscert.enable [no]
              Enable fetching of CERT RRs via DNS.

       charon.plugins.duplicheck.enable [yes]
              Enable duplicheck plugin (if loaded).

       charon.plugins.duplicheck.socket [unix://${piddir}/charon.dck]
              Socket provided by the duplicheck plugin.

       charon.plugins.eap-aka.request_identity [yes]

       charon.plugins.eap-aka-3gpp.seq_check []
              Enable to activate sequence check of the AKA SQN values in order to trigger resync cycles.

       charon.plugins.eap-aka-3gpp2.seq_check []
              Enable to activate sequence check of the AKA SQN values in order to trigger resync cycles.

       charon.plugins.eap-dynamic.prefer_user [no]
              If enabled the EAP methods proposed in an EAP-Nak message sent by the peer are preferred over  the
              methods registered locally.

       charon.plugins.eap-dynamic.preferred []
              The  preferred  EAP  method(s) to be used.  If it is not given the first registered method will be
              used initially.  If a comma separated list is given the methods  are  tried  in  the  given  order
              before trying the rest of the registered methods.

       charon.plugins.eap-gtc.backend [pam]
              XAuth backend to be used for credential verification.

       charon.plugins.eap-peap.fragment_size [1024]
              Maximum size of an EAP-PEAP packet.

       charon.plugins.eap-peap.include_length [no]
              Include length in non-fragmented EAP-PEAP packets.

       charon.plugins.eap-peap.max_message_count [32]
              Maximum number of processed EAP-PEAP packets (0 = no limit).

       charon.plugins.eap-peap.phase2_method [mschapv2]
              Phase2 EAP client authentication method.

       charon.plugins.eap-peap.phase2_piggyback [no]
              Phase2 EAP Identity request piggybacked by server onto TLS Finished message.

       charon.plugins.eap-peap.phase2_tnc [no]
              Start phase2 EAP TNC protocol after successful client authentication.

       charon.plugins.eap-peap.request_peer_auth [no]
              Request peer authentication based on a client certificate.

       charon.plugins.eap-radius.accounting [no]
              Send RADIUS accounting information to RADIUS servers.

       charon.plugins.eap-radius.accounting_close_on_timeout [yes]
              Close the IKE_SA if there is a timeout during interim RADIUS accounting updates.

       charon.plugins.eap-radius.accounting_interval [0]
              Interval  in  seconds for interim RADIUS accounting updates, if not specified by the RADIUS server
              in the Access-Accept message.

       charon.plugins.eap-radius.accounting_requires_vip [no]
              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.

       charon.plugins.eap-radius.accounting_send_class [no]
              If  enabled,  adds the Class attributes received in Access-Accept message to the RADIUS accounting
              messages.

       charon.plugins.eap-radius.class_group [no]
              Use the class attribute sent in the RADIUS-Accept message as group membership information that  is
              compared to the groups specified in the rightgroups option in ipsec.conf(5).

       charon.plugins.eap-radius.close_all_on_timeout [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.

       charon.plugins.eap-radius.dae.enable [no]
              Enables support for the Dynamic Authorization Extension (RFC 5176).

       charon.plugins.eap-radius.dae.listen [0.0.0.0]
              Address to listen for DAE messages from the RADIUS server.

       charon.plugins.eap-radius.dae.port [3799]
              Port to listen for DAE requests.

       charon.plugins.eap-radius.dae.secret []
              Shared secret used to verify/sign DAE messages. If set, make sure to adjust the permissions of the
              config file accordingly.

       charon.plugins.eap-radius.eap_start [no]
              Send EAP-Start instead of EAP-Identity to start RADIUS conversation.

       charon.plugins.eap-radius.filter_id [no]
              If the RADIUS tunnel_type attribute with value ESP is received, use the filter_id  attribute  sent
              in  the  RADIUS-Accept  message  as  group  membership  information that is compared to the groups
              specified in the rightgroups option in ipsec.conf(5).

       charon.plugins.eap-radius.forward.ike_to_radius []
              RADIUS attributes to be forwarded from IKEv2 to RADIUS  (can  be  defined  by  name  or  attribute
              number,  a  colon can be used to specify vendor-specific attributes, e.g. Reply-Message, or 11, or
              36906:12).

       charon.plugins.eap-radius.forward.radius_to_ike []
              Same as charon.plugins.eap-radius.forward.ike_to_radius but from RADIUS  to  IKEv2,  a  strongSwan
              specific private notify (40969) is used to transmit the attributes.

       charon.plugins.eap-radius.id_prefix []
              Prefix to EAP-Identity, some AAA servers use a IMSI prefix to select the EAP method.

       charon.plugins.eap-radius.nas_identifier [strongSwan]
              NAS-Identifier to include in RADIUS messages.

       charon.plugins.eap-radius.port [1812]
              Port of RADIUS server (authentication).

       charon.plugins.eap-radius.retransmit_base [1.4]
              Base to use for calculating exponential back off.

       charon.plugins.eap-radius.retransmit_timeout [2.0]
              Timeout in seconds before sending first retransmit.

       charon.plugins.eap-radius.retransmit_tries [4]
              Number of times to retransmit a packet before giving up.

       charon.plugins.eap-radius.secret []
              Shared  secret  between  RADIUS and NAS. If set, make sure to adjust the permissions of the config
              file accordingly.

       charon.plugins.eap-radius.server []
              IP/Hostname of RADIUS server.

       charon.plugins.eap-radius.servers
              Section to specify multiple RADIUS servers. The  nas_identifier,  secret,  sockets  and  port  (or
              auth_port)  options  can  be  specified  for each server. A server's IP/Hostname can be configured
              using the address option.  The acct_port [1813] option can be used to specify the  port  used  for
              RADIUS  accounting.  For  each  RADIUS server a priority can be specified using the preference [0]
              option.  The  retransmission  time  for  each  server   can   set   set   using   retransmit_base,
              retransmit_timeout and retransmit_tries.

       charon.plugins.eap-radius.sockets [1]
              Number of sockets (ports) to use, increase for high load.

       charon.plugins.eap-radius.xauth
              Section  to  configure  multiple XAuth authentication rounds via RADIUS. The subsections define so
              called authentication profiles with arbitrary names. In each profile section  one  or  more  XAuth
              types can be configured, with an assigned message. For each type a separate XAuth exchange will be
              initiated  and  all  replies  get  concatenated  into the User-Password attribute, which then gets
              verified over RADIUS.

              Available XAuth types are password, passcode, nextpin, and answer.  This type is not  relevant  to
              strongSwan  or  the  AAA  server,  but  the  client  may  show  a different dialog (along with the
              configured message).

              To use the configured profiles, they have  to  be  configured  in  the  respective  connection  in
              ipsec.conf(5)  by  appending  the  profile  name, separated by a colon, to the xauth-radius XAauth
              backend configuration in rightauth or rightauth2, for instance, rightauth2=xauth-radius:profile.

       charon.plugins.eap-sim.request_identity [yes]

       charon.plugins.eap-simaka-sql.database []

       charon.plugins.eap-simaka-sql.remove_used [no]

       charon.plugins.eap-tls.fragment_size [1024]
              Maximum size of an EAP-TLS packet.

       charon.plugins.eap-tls.include_length [yes]
              Include length in non-fragmented EAP-TLS packets.

       charon.plugins.eap-tls.max_message_count [32]
              Maximum number of processed EAP-TLS packets (0 = no limit).

       charon.plugins.eap-tnc.max_message_count [10]
              Maximum number of processed EAP-TNC packets (0 = no limit).

       charon.plugins.eap-tnc.protocol [tnccs-2.0]
              IF-TNCCS protocol version to be used (tnccs-1.1, tnccs-2.0, tnccs-dynamic).

       charon.plugins.eap-ttls.fragment_size [1024]
              Maximum size of an EAP-TTLS packet.

       charon.plugins.eap-ttls.include_length [yes]
              Include length in non-fragmented EAP-TTLS packets.

       charon.plugins.eap-ttls.max_message_count [32]
              Maximum number of processed EAP-TTLS packets (0 = no limit).

       charon.plugins.eap-ttls.phase2_method [md5]
              Phase2 EAP client authentication method.

       charon.plugins.eap-ttls.phase2_piggyback [no]
              Phase2 EAP Identity request piggybacked by server onto TLS Finished message.

       charon.plugins.eap-ttls.phase2_tnc [no]
              Start phase2 EAP TNC protocol after successful client authentication.

       charon.plugins.eap-ttls.phase2_tnc_method [pt]
              Phase2 EAP TNC transport protocol (pt as IETF standard or legacy tnc)

       charon.plugins.eap-ttls.request_peer_auth [no]
              Request peer authentication based on a client certificate.

       charon.plugins.error-notify.socket [unix://${piddir}/charon.enfy]
              Socket provided by the error-notify plugin.

       charon.plugins.ext-auth.script []
              Command to pass to the system shell for peer authorization. Authorization is considered successful
              if the command executes normally with an exit code of  zero.  For  all  other  exit  codes  IKE_SA
              authorization is rejected.

              The  following environment variables get passed to the script: IKE_UNIQUE_ID: The IKE_SA numerical
              unique identifier.  IKE_NAME: The peer configuration connection name.  IKE_LOCAL_HOST:  Local  IKE
              IP   address.   IKE_REMOTE_HOST:  Remote  IKE  IP  address.   IKE_LOCAL_ID:  Local  IKE  identity.
              IKE_REMOTE_ID: Remote IKE identity.  IKE_REMOTE_EAP_ID: Remote EAP or XAuth identity, if used.

       charon.plugins.forecast.groups [224.0.0.1,224.0.0.22,224.0.0.251,224.0.0.252,239.255.255.250]
              Comma separated list of multicast groups to join locally. The local  host  receives  and  forwards
              packets in the local LAN for joined multicast groups only.  Packets matching the list of multicast
              groups get forwarded to connected clients. The default group includes host multicasts, IGMP, mDNS,
              LLMNR and SSDP/WS-Discovery, and is usually a good choice for Windows clients.

       charon.plugins.forecast.interface []
              Name  of  the  local  interface  to  listen for broadcasts messages to forward. If no interface is
              configured, the first usable interface is used, which is usually just fine for single-homed hosts.
              If your host has multiple interfaces, set this option to the  local  LAN  interface  you  want  to
              forward broadcasts from/to.

       charon.plugins.forecast.reinject []
              Comma  separated  list  of  CHILD_SA  configuration  names  for  which  to perform multi/broadcast
              reinjection. For clients connecting over such a configuration, any multi/broadcast  received  over
              the  tunnel  gets  reinjected  to  all  active tunnels. This makes the broadcasts visible to other
              peers, and for examples allows clients to see others shares. If disabled, multi/broadcast messages
              received over a tunnel are injected to the local network only, but not to other IPsec clients.

       charon.plugins.gcrypt.quick_random [no]
              Use faster random numbers in gcrypt; for testing only, produces weak keys!

       charon.plugins.ha.autobalance [0]
              Interval in seconds to automatically balance handled segments between nodes. Set to 0 to disable.

       charon.plugins.ha.fifo_interface [yes]

       charon.plugins.ha.heartbeat_delay [1000]

       charon.plugins.ha.heartbeat_timeout [2100]

       charon.plugins.ha.local []

       charon.plugins.ha.monitor [yes]

       charon.plugins.ha.pools []

       charon.plugins.ha.remote []

       charon.plugins.ha.resync [yes]

       charon.plugins.ha.secret []

       charon.plugins.ha.segment_count [1]

       charon.plugins.ipseckey.enable [no]
              Enable fetching of IPSECKEY RRs via DNS.

       charon.plugins.kernel-libipsec.allow_peer_ts [no]
              Allow that the remote traffic selector equals the IKE peer. The route installed for  such  traffic
              (via  TUN  device) usually prevents further IKE traffic. The fwmark options for the kernel-netlink
              and socket-default plugins can be used to circumvent that problem.

       charon.plugins.kernel-netlink.buflen [<min(PAGE_SIZE, 8192)>]
              Buffer size for received Netlink messages.

       charon.plugins.kernel-netlink.force_receive_buffer_size [no]
              If the maximum Netlink socket receive buffer in  bytes  set  by  receive_buffer_size  exceeds  the
              system-wide  maximum  from  /proc/sys/net/core/rmem_max,  this  option can be used to override the
              limit.  Enabling this option requires special privileges (CAP_NET_ADMIN).

       charon.plugins.kernel-netlink.fwmark []
              Firewall mark to set on the routing rule that directs traffic to our routing table. The format  is
              [!]mark[/mask],  where  the  optional  exclamation  mark  inverts  the meaning (i.e. the rule only
              applies to packets that don't match the mark).

       charon.plugins.kernel-netlink.ignore_retransmit_errors [no]
              Whether to ignore errors potentially resulting from a retransmission.

       charon.plugins.kernel-netlink.mss [0]
              MSS to set on installed routes, 0 to disable.

       charon.plugins.kernel-netlink.mtu [0]
              MTU to set on installed routes, 0 to disable.

       charon.plugins.kernel-netlink.parallel_route [no]
              Whether to perform concurrent Netlink ROUTE queries on a single socket. While parallel queries can
              improve throughput, it has more overhead. On vanilla Linux, DUMP queries fail with EBUSY and  must
              be retried, further decreasing performance.

       charon.plugins.kernel-netlink.parallel_xfrm [no]
              Whether to perform concurrent Netlink XFRM queries on a single socket.

       charon.plugins.kernel-netlink.policy_update [no]
              Whether to always use XFRM_MSG_UPDPOLICY to install policies.

       charon.plugins.kernel-netlink.port_bypass [no]
              Whether  to  use  port  or  socket based IKE XFRM bypass policies. IKE bypass policies are used to
              exempt IKE traffic from XFRM processing. The default socket based policies are  directly  tied  to
              the  IKE  UDP  sockets,  port  based policies use global XFRM bypass policies for the used IKE UDP
              ports.

       charon.plugins.kernel-netlink.process_rules [no]
              Whether to process changes in routing rules to trigger roam events. This is currently only  useful
              if  the  kernel  based route lookup is used (i.e. if route installation is disabled or an inverted
              fwmark match is configured).

       charon.plugins.kernel-netlink.receive_buffer_size [0]
              Maximum Netlink socket receive buffer in bytes. This value controls  how  many  bytes  of  Netlink
              messages   can   be   received   on   a   Netlink   socket.   The   default   value   is   set  by
              /proc/sys/net/core/rmem_default. The specified value cannot exceed the  system-wide  maximum  from
              /proc/sys/net/core/rmem_max, unless force_receive_buffer_size is enabled.

       charon.plugins.kernel-netlink.retries [0]
              Number of Netlink message retransmissions to send on timeout.

       charon.plugins.kernel-netlink.roam_events [yes]
              Whether to trigger roam events when interfaces, addresses or routes change.

       charon.plugins.kernel-netlink.set_proto_port_transport_sa [no]
              Whether  to  set  protocol  and ports in the selector installed on transport mode IPsec SAs in the
              kernel. While doing so enforces policies for inbound traffic, it also prevents the use of a single
              IPsec SA by more than one traffic selector.

       charon.plugins.kernel-netlink.spdh_thresh
              XFRM policy hashing threshold configuration for IPv4 and IPv6.

              The section defines hashing thresholds to configure in the  kernel  during  daemon  startup.  Each
              address family takes a threshold for the local subnet of an IPsec policy (src in out-policies, dst
              in  in-  and  forward-policies)  and  the  remote  subnet  (dst  in  out-policies,  src in in- and
              forward-policies).

              If the subnet has more or equal net bits than the threshold, the first threshold bits are used  to
              calculate a hash to lookup the policy.

              Policy  hashing  thresholds  are  not  supported  before Linux 3.18 and might conflict with socket
              policies before Linux 4.8.

       charon.plugins.kernel-netlink.spdh_thresh.ipv4.lbits [32]
              Local subnet XFRM policy hashing threshold for IPv4.

       charon.plugins.kernel-netlink.spdh_thresh.ipv4.rbits [32]
              Remote subnet XFRM policy hashing threshold for IPv4.

       charon.plugins.kernel-netlink.spdh_thresh.ipv6.lbits [128]
              Local subnet XFRM policy hashing threshold for IPv6.

       charon.plugins.kernel-netlink.spdh_thresh.ipv6.rbits [128]
              Remote subnet XFRM policy hashing threshold for IPv6.

       charon.plugins.kernel-netlink.timeout [0]
              Netlink message retransmission timeout, 0 to disable retransmissions.

       charon.plugins.kernel-netlink.xfrm_acq_expires [165]
              Lifetime of XFRM acquire state created by the kernel when traffic matches a trap policy. The value
              gets written to /proc/sys/net/core/xfrm_acq_expires.  Indirectly controls the delay  between  XFRM
              acquire  messages triggered by the kernel for a trap policy. The same value is used as timeout for
              SPIs allocated by the kernel. The default value equals the total   retransmission timeout for  IKE
              messages, see IKEv2 RETRANSMISSION in strongswan.conf(5).

       charon.plugins.kernel-pfkey.events_buffer_size [0]
              Size  of the receive buffer for the event socket (0 for default size). Because events are received
              asynchronously installing e.g. lots of policies may require a larger buffer than  the  default  on
              certain platforms in order to receive all messages.

       charon.plugins.kernel-pfroute.vip_wait [1000]
              Time in ms to wait until virtual IP addresses appear/disappear before failing.

       charon.plugins.led.activity_led []

       charon.plugins.led.blink_time [50]

       charon.plugins.load-tester
              Section to configure the load-tester plugin, see LOAD TESTS in strongswan.conf(5) for details.

       charon.plugins.load-tester.addrs
              Section  that contains key/value pairs with address pools (in CIDR notation) to use for a specific
              network interface e.g. eth0 = 10.10.0.0/16.

       charon.plugins.load-tester.addrs_keep [no]
              Whether to keep dynamic addresses even after the associated SA got terminated.

       charon.plugins.load-tester.addrs_prefix [16]
              Network prefix length to use when installing dynamic addresses. If set to -1 the full  address  is
              used (i.e. 32 or 128).

       charon.plugins.load-tester.ca_dir []
              Directory to load (intermediate) CA certificates from.

       charon.plugins.load-tester.child_rekey [600]
              Seconds to start CHILD_SA rekeying after setup.

       charon.plugins.load-tester.crl []
              URI to a CRL to include as certificate distribution point in generated certificates.

       charon.plugins.load-tester.delay [0]
              Delay between initiatons for each thread.

       charon.plugins.load-tester.delete_after_established [no]
              Delete an IKE_SA as soon as it has been established.

       charon.plugins.load-tester.digest [sha1]
              Digest algorithm used when issuing certificates.

       charon.plugins.load-tester.dpd_delay [0]
              DPD delay to use in load test.

       charon.plugins.load-tester.dynamic_port [0]
              Base port to be used for requests (each client uses a different port).

       charon.plugins.load-tester.eap_password [default-pwd]
              EAP secret to use in load test.

       charon.plugins.load-tester.enable [no]
              Enable  the  load  testing  plugin.   WARNING:  Never enable this plugin on productive systems. It
              provides preconfigured credentials and allows an attacker to authenticate as any user.

       charon.plugins.load-tester.esp [aes128-sha1]
              CHILD_SA proposal to use for load tests.

       charon.plugins.load-tester.fake_kernel [no]
              Fake the kernel interface to allow load-testing against self.

       charon.plugins.load-tester.ike_rekey [0]
              Seconds to start IKE_SA rekeying after setup.

       charon.plugins.load-tester.init_limit [0]
              Global limit of concurrently established SAs during load test.

       charon.plugins.load-tester.initiator [0.0.0.0]
              Address to initiate from.

       charon.plugins.load-tester.initiator_auth [pubkey]
              Authentication method(s) the intiator uses.

       charon.plugins.load-tester.initiator_id []
              Initiator ID used in load test.

       charon.plugins.load-tester.initiator_match []
              Initiator ID to match against as responder.

       charon.plugins.load-tester.initiator_tsi []
              Traffic selector on initiator side, as proposed by initiator.

       charon.plugins.load-tester.initiator_tsr []
              Traffic selector on responder side, as proposed by initiator.

       charon.plugins.load-tester.initiators [0]
              Number of concurrent initiator threads to use in load test.

       charon.plugins.load-tester.issuer_cert []
              Path to the issuer certificate (if not configured a hard-coded default value is used).

       charon.plugins.load-tester.issuer_key []
              Path to private key that is used to issue certificates (if not  configured  a  hard-coded  default
              value is used).

       charon.plugins.load-tester.iterations [1]
              Number of IKE_SAs to initiate by each initiator in load test.

       charon.plugins.load-tester.mode [tunnel]
              IPsec mode to use, one of tunnel, transport, or beet.

       charon.plugins.load-tester.pool []
              Provide INTERNAL_IPV4_ADDRs from a named pool.

       charon.plugins.load-tester.preshared_key [<default-psk>]
              Preshared key to use in load test.

       charon.plugins.load-tester.proposal [aes128-sha1-modp768]
              IKE proposal to use in load test.

       charon.plugins.load-tester.request_virtual_ip [no]
              Request an INTERNAL_IPV4_ADDR from the server.

       charon.plugins.load-tester.responder [127.0.0.1]
              Address to initiation connections to.

       charon.plugins.load-tester.responder_auth [pubkey]
              Authentication method(s) the responder uses.

       charon.plugins.load-tester.responder_id []
              Responder ID used in load test.

       charon.plugins.load-tester.responder_tsi [initiator_tsi]
              Traffic selector on initiator side, as narrowed by responder.

       charon.plugins.load-tester.responder_tsr [initiator_tsr]
              Traffic selector on responder side, as narrowed by responder.

       charon.plugins.load-tester.shutdown_when_complete [no]
              Shutdown the daemon after all IKE_SAs have been established.

       charon.plugins.load-tester.socket [unix://${piddir}/charon.ldt]
              Socket provided by the load-tester plugin.

       charon.plugins.load-tester.version [0]
              IKE version to use (0 means use IKEv2 as initiator and accept any version as responder).

       charon.plugins.lookip.socket [unix://${piddir}/charon.lkp]
              Socket provided by the lookip plugin.

       charon.plugins.ntru.max_drbg_requests [4294967294]
              Number of pseudo-random bit requests from the DRBG before an automatic reseeding occurs.

       charon.plugins.ntru.parameter_set [optimum]
              The  following  parameter  sets  are  available:  x9_98_speed,  x9_98_bandwidth, x9_98_balance and
              optimum, the last set not being part of the X9.98 standard but having the best performance.

       charon.plugins.openssl.engine_id [pkcs11]
              ENGINE ID to use in the OpenSSL plugin.

       charon.plugins.openssl.fips_mode [0]
              Set OpenSSL FIPS mode: disabled(0), enabled(1), Suite B enabled(2).

       charon.plugins.osx-attr.append [yes]
              Whether DNS servers are appended to existing entries, instead of replacing them.

       charon.plugins.p-cscf.enable
              Section to enable requesting P-CSCF server addresses for individual connections.

       charon.plugins.p-cscf.enable.<conn> [no]
              <conn> is the name of a connection with an ePDG from which to  request  P-CSCF  server  addresses.
              Requests will be sent for addresses of the same families for which internal IPs are requested.

       charon.plugins.pkcs11.modules
              List of available PKCS#11 modules.

       charon.plugins.pkcs11.modules.<name>.load_certs [yes]
              Whether to automatically load certificates from tokens.

       charon.plugins.pkcs11.modules.<name>.os_locking [no]
              Whether OS locking should be enabled for this module.

       charon.plugins.pkcs11.modules.<name>.path []
              Full path to the shared object file of this PKCS#11 module.

       charon.plugins.pkcs11.reload_certs [no]
              Reload certificates from all tokens if charon receives a SIGHUP.

       charon.plugins.pkcs11.use_dh [no]
              Whether the PKCS#11 modules should be used for DH and ECDH (see use_ecc option).

       charon.plugins.pkcs11.use_ecc [no]
              Whether the PKCS#11 modules should be used for ECDH and ECDSA public key operations. ECDSA private
              keys can be used regardless of this option.

       charon.plugins.pkcs11.use_hasher [no]
              Whether the PKCS#11 modules should be used to hash data.

       charon.plugins.pkcs11.use_pubkey [no]
              Whether  the PKCS#11 modules should be used for public key operations, even for keys not stored on
              tokens.

       charon.plugins.pkcs11.use_rng [no]
              Whether the PKCS#11 modules should be used as RNG.

       charon.plugins.radattr.dir []
              Directory where RADIUS attributes are stored in client-ID specific files.

       charon.plugins.radattr.message_id [-1]
              Attributes are added to all IKE_AUTH messages by default (-1), or only  to  the  IKE_AUTH  message
              with the given IKEv2 message ID.

       charon.plugins.random.random [${random_device}]
              File to read random bytes from.

       charon.plugins.random.strong_equals_true [no]
              If set to yes the RNG_STRONG class reads random bytes from the same source as the RNG_TRUE class.

       charon.plugins.random.urandom [${urandom_device}]
              File to read pseudo random bytes from.

       charon.plugins.resolve.file [/etc/resolv.conf]
              File where to add DNS server entries.

       charon.plugins.resolve.resolvconf.iface_prefix [lo.inet.ipsec.]
              Prefix used for interface names sent to resolvconf(8).  The nameserver address is appended to this
              prefix  to  make  it  unique.   The result has to be a valid interface name according to the rules
              defined by resolvconf.  Also, it should have a high priority according to  the  order  defined  in
              interface-order(5).

       charon.plugins.revocation.enable_crl [yes]
              Whether CRL validation should be enabled.

       charon.plugins.revocation.enable_ocsp [yes]
              Whether OCSP validation should be enabled.

       charon.plugins.save-keys.esp [no]
              Whether to save ESP keys.

       charon.plugins.save-keys.ike [no]
              Whether to save IKE keys.

       charon.plugins.save-keys.load [no]
              Whether to load the plugin.

       charon.plugins.save-keys.wireshark_keys []
              Directory where the keys are stored in the format supported by Wireshark. IKEv1 keys are stored in
              the  ikev1_decryption_table  file.  IKEv2 keys are stored in the ikev2_decryption_table file. Keys
              for ESP CHILD_SAs are stored in the esp_sa file.

       charon.plugins.socket-default.fwmark []
              Firewall mark to set on outbound packets.

       charon.plugins.socket-default.set_source [yes]
              Set source address on outbound packets, if possible.

       charon.plugins.socket-default.set_sourceif [no]
              Force sending interface on outbound packets,  if  possible.  This  allows  using  IPv6  link-local
              addresses as tunnel endpoints.

       charon.plugins.socket-default.use_ipv4 [yes]
              Listen on IPv4, if possible.

       charon.plugins.socket-default.use_ipv6 [yes]
              Listen on IPv6, if possible.

       charon.plugins.sql.database []
              Database  URI  for  charon's  SQL  plugin.  If  it  contains  a  password, make sure to adjust the
              permissions of the config file accordingly.

       charon.plugins.sql.loglevel [-1]
              Loglevel for logging to SQL database.

       charon.plugins.stroke.allow_swap [yes]
              Analyze addresses/hostnames in left|right to detect which side is  local  and  swap  configuration
              options if necessary. If disabled left is always local.

       charon.plugins.stroke.ignore_missing_ca_basic_constraint [no]
              Treat  certificates  in ipsec.d/cacerts and ipsec.conf ca sections as CA certificates even if they
              don't contain a CA basic constraint.

       charon.plugins.stroke.max_concurrent [4]
              Maximum number of stroke messages handled concurrently.

       charon.plugins.stroke.prevent_loglevel_changes [no]
              If enabled log level changes via stroke socket are not allowed.

       charon.plugins.stroke.secrets_file [${sysconfdir}/ipsec.secrets]
              Location of the ipsec.secrets file

       charon.plugins.stroke.socket [unix://${piddir}/charon.ctl]
              Socket provided by the stroke plugin.

       charon.plugins.stroke.timeout [0]
              Timeout in ms for any stroke command. Use 0 to disable the timeout.

       charon.plugins.systime-fix.interval [0]
              Interval in seconds to check system time for validity. 0 disables the check.

       charon.plugins.systime-fix.reauth [no]
              Whether to use reauth or delete if an invalid cert lifetime is detected.

       charon.plugins.systime-fix.threshold []
              Threshold date where system time is considered valid. Disabled if not specified.

       charon.plugins.systime-fix.threshold_format [%Y]
              strptime(3) format used to parse threshold option.

       charon.plugins.systime-fix.timeout [0s]
              How long to wait for a valid system time if an interval is configured. 0 to recheck indefinitely.

       charon.plugins.tnc-ifmap.client_cert []
              Path to X.509 certificate file of IF-MAP client.

       charon.plugins.tnc-ifmap.client_key []
              Path to private key file of IF-MAP client.

       charon.plugins.tnc-ifmap.device_name []
              Unique name of strongSwan server as a PEP and/or PDP device.

       charon.plugins.tnc-ifmap.renew_session_interval [150]
              Interval in seconds between periodic IF-MAP RenewSession requests.

       charon.plugins.tnc-ifmap.server_cert []
              Path to X.509 certificate file of IF-MAP server.

       charon.plugins.tnc-ifmap.server_uri [https://localhost:8444/imap]
              URI of the form [https://]servername[:port][/path].

       charon.plugins.tnc-ifmap.username_password []
              Credentials of IF-MAP client of the form username:password.  If  set,  make  sure  to  adjust  the
              permissions of the config file accordingly.

       charon.plugins.tnc-imc.dlclose [yes]
              Unload IMC after use.

       charon.plugins.tnc-imc.preferred_language [en]
              Preferred language for TNC recommendations.

       charon.plugins.tnc-imv.dlclose [yes]
              Unload IMV after use.

       charon.plugins.tnc-imv.recommendation_policy [default]
              TNC recommendation policy, one of default, any, or all.

       charon.plugins.tnc-pdp.pt_tls.enable [yes]
              Enable PT-TLS protocol on the strongSwan PDP.

       charon.plugins.tnc-pdp.pt_tls.port [271]
              PT-TLS server port the strongSwan PDP is listening on.

       charon.plugins.tnc-pdp.radius.enable [yes]
              Enable RADIUS protocol on the strongSwan PDP.

       charon.plugins.tnc-pdp.radius.method [ttls]
              EAP tunnel method to be used.

       charon.plugins.tnc-pdp.radius.port [1812]
              RADIUS server port the strongSwan PDP is listening on.

       charon.plugins.tnc-pdp.radius.secret []
              Shared  RADIUS  secret between strongSwan PDP and NAS. If set, make sure to adjust the permissions
              of the config file accordingly.

       charon.plugins.tnc-pdp.server []
              Name of the strongSwan PDP as contained in the AAA certificate.

       charon.plugins.tnc-pdp.timeout []
              Timeout in seconds before closing incomplete connections.

       charon.plugins.tnccs-11.max_message_size [45000]
              Maximum size of a PA-TNC message (XML & Base64 encoding).

       charon.plugins.tnccs-20.max_batch_size [65522]
              Maximum size of a PB-TNC batch (upper limit via PT-EAP = 65529).

       charon.plugins.tnccs-20.max_message_size [65490]
              Maximum size of a PA-TNC message (upper limit via PT-EAP = 65497).

       charon.plugins.tnccs-20.mutual [no]
              Enable PB-TNC mutual protocol.

       charon.plugins.tnccs-20.tests.pb_tnc_noskip [no]
              Send an unsupported PB-TNC message type with the NOSKIP flag set.

       charon.plugins.tnccs-20.tests.pb_tnc_version [2]
              Send a PB-TNC batch with a modified PB-TNC version.

       charon.plugins.tpm.use_rng [no]
              Whether the TPM should be used as RNG.

       charon.plugins.unbound.dlv_anchors []
              File to read trusted keys for DLV (DNSSEC Lookaside Validation) from. It uses the same  format  as
              trust_anchors.   Only  one  DLV  can be configured, which is then used as a root trusted DLV, this
              means that it is a lookaside for the root.

       charon.plugins.unbound.resolv_conf [/etc/resolv.conf]
              File to read DNS resolver configuration from.

       charon.plugins.unbound.trust_anchors [/etc/ipsec.d/dnssec.keys]
              File to read DNSSEC trust anchors from (usually root zone KSK). The format  of  the  file  is  the
              standard DNS Zone file format, anchors can be stored as DS or DNSKEY entries in the file.

       charon.plugins.updown.dns_handler [no]
              Whether the updown script should handle DNS servers assigned via IKEv1 Mode Config or IKEv2 Config
              Payloads (if enabled they can't be handled by other plugins, like resolve)

       charon.plugins.vici.socket [unix://${piddir}/charon.vici]
              Socket the vici plugin serves clients.

       charon.plugins.whitelist.enable [yes]
              Enable loaded whitelist plugin.

       charon.plugins.whitelist.socket [unix://${piddir}/charon.wlst]
              Socket provided by the whitelist plugin.

       charon.plugins.xauth-eap.backend [radius]
              EAP plugin to be used as backend for XAuth credential verification.

       charon.plugins.xauth-pam.pam_service [login]
              PAM service to be used for authentication.

       charon.plugins.xauth-pam.session [no]
              Open/close a PAM session for each active IKE_SA.

       charon.plugins.xauth-pam.trim_email [yes]
              If an email address is received as an XAuth username, trim it to just the username part.

       charon.port [500]
              UDP port used locally. If set to 0 a random port will be allocated.

       charon.port_nat_t [4500]
              UDP  port  used  locally in case of NAT-T. If set to 0 a random port will be allocated.  Has to be
              different from charon.port, otherwise a random port will be allocated.

       charon.prefer_best_path [no]
              By default, charon keeps SAs on the routing path with addresses it previously used if that path is
              still usable. By setting this option to yes, it tries more aggressively to update SAs with  MOBIKE
              on  routing  priority  changes  using  the  cheapest  path.  This  adds  more noise, but allows to
              dynamically adapt SAs to routing priority changes. This option has no  effect  if  MOBIKE  is  not
              supported or disabled.

       charon.prefer_configured_proposals [yes]
              Prefer  locally configured proposals for IKE/IPsec over supplied ones as responder (disabling this
              can avoid keying retries due to INVALID_KE_PAYLOAD notifies).

       charon.prefer_temporary_addrs [no]
              By default public IPv6 addresses are preferred over temporary ones (RFC 4941), to make connections
              more stable. Enable this option to reverse this.

       charon.process_route [yes]
              Process RTM_NEWROUTE and RTM_DELROUTE events.

       charon.processor.priority_threads
              Section to configure the number of reserved threads per priority class see JOB PRIORITY MANAGEMENT
              in strongswan.conf(5).

       charon.receive_delay [0]
              Delay in ms for receiving packets, to simulate larger RTT.

       charon.receive_delay_request [yes]
              Delay request messages.

       charon.receive_delay_response [yes]
              Delay response messages.

       charon.receive_delay_type [0]
              Specific IKEv2 message type to delay, 0 for any.

       charon.replay_window [32]
              Size of the AH/ESP replay window, in packets.

       charon.retransmit_base [1.8]
              Base to use for calculating exponential back off, see IKEv2 RETRANSMISSION in strongswan.conf(5).

       charon.retransmit_jitter [0]
              Maximum jitter in percent to apply randomly to calculated retransmission timeout (0 to disable).

       charon.retransmit_limit [0]
              Upper limit in seconds for calculated retransmission timeout (0 to disable).

       charon.retransmit_timeout [4.0]
              Timeout in seconds before sending first retransmit.

       charon.retransmit_tries [5]
              Number of times to retransmit a packet before giving up.

       charon.retry_initiate_interval [0]
              Interval in seconds to use when retrying to initiate an IKE_SA (e.g. if DNS resolution failed),  0
              to disable retries.

       charon.reuse_ikesa [yes]
              Initiate CHILD_SA within existing IKE_SAs (always enabled for IKEv1).

       charon.routing_table []
              Numerical routing table to install routes to.

       charon.routing_table_prio []
              Priority of the routing table.

       charon.rsa_pss [no]
              Whether to use RSA with PSS padding instead of PKCS#1 padding by default.

       charon.send_delay [0]
              Delay in ms for sending packets, to simulate larger RTT.

       charon.send_delay_request [yes]
              Delay request messages.

       charon.send_delay_response [yes]
              Delay response messages.

       charon.send_delay_type [0]
              Specific IKEv2 message type to delay, 0 for any.

       charon.send_vendor_id [no]
              Send strongSwan vendor ID payload

       charon.signature_authentication [yes]
              Whether to enable Signature Authentication as per RFC 7427.

       charon.signature_authentication_constraints [yes]
              If  enabled, signature schemes configured in rightauth, in addition to getting used as constraints
              against signature schemes employed in the certificate chain, are also used as constraints  against
              the signature scheme used by peers during IKEv2.

       charon.spi_max [0xcfffffff]
              The upper limit for SPIs requested from the kernel for IPsec SAs.

       charon.spi_min [0xc0000000]
              The  lower  limit  for  SPIs requested from the kernel for IPsec SAs. Should not be set lower than
              0x00000100 (256), as SPIs between 1 and 255 are reserved by IANA.

       charon.start-scripts
              Section containing a list of scripts (name = path) that are executed when the daemon is started.

       charon.stop-scripts
              Section containing a list of  scripts  (name  =  path)  that  are  executed  when  the  daemon  is
              terminated.

       charon.syslog
              Section to define syslog loggers, see LOGGER CONFIGURATION in strongswan.conf(5).

       charon.syslog.<facility>
              <facility>   is   one   of   the   supported   syslog  facilities,  see  LOGGER  CONFIGURATION  in
              strongswan.conf(5).

       charon.syslog.<facility>.<subsystem> [<default>]
              Loglevel for a specific subsystem.

       charon.syslog.<facility>.default [1]
              Specifies the default loglevel to be used  for  subsystems  for  which  no  specific  loglevel  is
              defined.

       charon.syslog.<facility>.ike_name [no]
              Prefix each log entry with the connection name and a unique numerical identifier for each IKE_SA.

       charon.syslog.identifier []
              Global  identifier  used  for an openlog(3) call, prepended to each log message by syslog.  If not
              configured, openlog(3) is not called, so the value will  depend  on  system  defaults  (often  the
              program name).

       charon.threads [16]
              Number  of  worker  threads  in  charon.  Several  of these are reserved for long running tasks in
              internal modules and plugins. Therefore, make sure you don't set this value too low. The number of
              idle worker threads listed in ipsec statusall might be used as indicator on the number of reserved
              threads.

       charon.tls.cipher []
              List of TLS encryption ciphers.

       charon.tls.key_exchange []
              List of TLS key exchange methods.

       charon.tls.mac []
              List of TLS MAC algorithms.

       charon.tls.suites []
              List of TLS cipher suites.

       charon.tnc.tnc_config [/etc/tnc_config]
              TNC IMC/IMV configuration file.

       charon.user []
              Name of the user the daemon changes to after startup.

       charon.x509.enforce_critical [yes]
              Discard certificates with unsupported or unknown critical extensions.

       charon-nm.ca_dir [<default>]
              Directory from which to load CA certificates if no certificate is configured.

       charon-systemd.journal
              Section to configure native systemd journal logger, very similar to the syslog logger as described
              in LOGGER CONFIGURATION in strongswan.conf(5).

       charon-systemd.journal.<subsystem> [<default>]
              Loglevel for a specific subsystem.

       charon-systemd.journal.default [1]
              Specifies the default loglevel to be used  for  subsystems  for  which  no  specific  loglevel  is
              defined.

       imv_policy_manager.command_allow []
              Shell command to be executed with recommendation allow.

       imv_policy_manager.command_block []
              Shell command to be executed with all other recommendations.

       imv_policy_manager.database []
              Database URI for the database that stores the package information. If it contains a password, make
              sure to adjust the permissions of the config file accordingly.

       imv_policy_manager.load [sqlite]
              Plugins to load in IMV policy manager.

       libimcv.debug_level [1]
              Debug level for a stand-alone libimcv library.

       libimcv.load [random nonce gmp pubkey x509]
              Plugins to load in IMC/IMVs with stand-alone libimcv library.

       libimcv.plugins.imc-attestation.aik_blob []
              AIK encrypted private key blob file.

       libimcv.plugins.imc-attestation.aik_cert []
              AIK certificate file.

       libimcv.plugins.imc-attestation.aik_handle []
              AIK object handle.

       libimcv.plugins.imc-attestation.aik_pubkey []
              AIK public key file.

       libimcv.plugins.imc-attestation.mandatory_dh_groups [yes]
              Enforce mandatory Diffie-Hellman groups.

       libimcv.plugins.imc-attestation.nonce_len [20]
              DH nonce length.

       libimcv.plugins.imc-attestation.pcr17_after []
              PCR17 value after measurement.

       libimcv.plugins.imc-attestation.pcr17_before []
              PCR17 value before measurement.

       libimcv.plugins.imc-attestation.pcr17_meas []
              Dummy measurement value extended into PCR17 if the TBOOT log is not available.

       libimcv.plugins.imc-attestation.pcr18_after []
              PCR18 value after measurement.

       libimcv.plugins.imc-attestation.pcr18_before []
              PCR18 value before measurement.

       libimcv.plugins.imc-attestation.pcr18_meas []
              Dummy measurement value extended into PCR17 if the TBOOT log is not available.

       libimcv.plugins.imc-attestation.pcr_info [no]
              Whether to send pcr_before and pcr_after info.

       libimcv.plugins.imc-attestation.use_quote2 [yes]
              Use Quote2 AIK signature instead of Quote signature.

       libimcv.plugins.imc-attestation.use_version_info [no]
              Version Info is included in Quote2 signature.

       libimcv.plugins.imc-hcd.push_info [yes]
              Send quadruple info without being prompted.

       libimcv.plugins.imc-hcd.subtypes []
              Section to define PWG HCD PA subtypes.

       libimcv.plugins.imc-hcd.subtypes.<section> []
              Defines  a  PWG  HCD  PA  subtype  section.  Recognized subtype section names are system, control,
              marker, finisher, interface and scanner.

       libimcv.plugins.imc-hcd.subtypes.<section>.<sw_type> []
              Defines  a  software  type  section.  Recognized  software  type  section  names   are   firmware,
              resident_application and user_application.

       libimcv.plugins.imc-hcd.subtypes.<section>.<sw_type>.<software> []
              Defines a software section having an arbitrary name.

       libimcv.plugins.imc-hcd.subtypes.<section>.<sw_type>.<software>.name []
              Name of the software installed on the hardcopy device.

       libimcv.plugins.imc-hcd.subtypes.<section>.<sw_type>.<software>.patches []
              String  describing  all  patches  applied  to  the  given  software  on  this hardcopy device. The
              individual patches are separated by a newline character '\n'.

       libimcv.plugins.imc-hcd.subtypes.<section>.<sw_type>.<software>.string_version []
              String describing the version of the given software on this hardcopy device.

       libimcv.plugins.imc-hcd.subtypes.<section>.<sw_type>.<software>.version []
              Hex-encoded version string with a length of 16 octets  consisting  of  the  fields  major  version
              number  (4  octets),  minor version number (4 octets), build number (4 octets), service pack major
              number (2 octets) and service pack minor number (2 octets).

       libimcv.plugins.imc-hcd.subtypes.<section>.attributes_natural_language [en]
              Variable length natural language tag conforming to RFC 5646 specifies the language to be  used  in
              the health assessment message of a given subtype.

       libimcv.plugins.imc-hcd.subtypes.system.certification_state []
              Hex-encoded certification state.

       libimcv.plugins.imc-hcd.subtypes.system.configuration_state []
              Hex-encoded configuration state.

       libimcv.plugins.imc-hcd.subtypes.system.machine_type_model []
              String specifying the machine type and model of the hardcopy device.

       libimcv.plugins.imc-hcd.subtypes.system.pstn_fax_enabled [no]
              Specifies if a PSTN facsimile interface is installed and enabled on the hardcopy device.

       libimcv.plugins.imc-hcd.subtypes.system.time_source []
              String specifying the hostname of the network time server used by the hardcopy device.

       libimcv.plugins.imc-hcd.subtypes.system.user_application_enabled [no]
              Specifies if users can dynamically download and execute applications on the hardcopy device.

       libimcv.plugins.imc-hcd.subtypes.system.user_application_persistence_enabled [no]
              Specifies  if  user  dynamically  downloaded  applications can persist outside the boundaries of a
              single job on the hardcopy device.

       libimcv.plugins.imc-hcd.subtypes.system.vendor_name []
              String specifying the manufacturer of the hardcopy device.

       libimcv.plugins.imc-hcd.subtypes.system.vendor_smi_code []
              Integer specifying the globally unique 24-bit  SMI  code  assigned  to  the  manufacturer  of  the
              hardcopy device.

       libimcv.plugins.imc-os.device_cert []
              Manually set the path to the client device certificate (e.g.  /etc/pts/aikCert.der)

       libimcv.plugins.imc-os.device_handle []
              Manually set handle to a private key bound to a smartcard or TPM (e.g.  0x81010004)

       libimcv.plugins.imc-os.device_id []
              Manually      set     the     client     device     ID     in     hexadecimal     format     (e.g.
              1083f03988c9762703b1c1080c2e46f72b99cc31)

       libimcv.plugins.imc-os.device_pubkey []
              Manually set the path to the client device public key (e.g. /etc/pts/aikPub.der)

       libimcv.plugins.imc-os.push_info [yes]
              Send operating system info without being prompted.

       libimcv.plugins.imc-scanner.push_info [yes]
              Send open listening ports without being prompted.

       libimcv.plugins.imc-swid.swid_directory [${prefix}/share]
              Directory where SWID tags are located.

       libimcv.plugins.imc-swid.swid_full [no]
              Include file information in the XML-encoded SWID tags.

       libimcv.plugins.imc-swid.swid_pretty [no]
              Generate XML-encoded SWID tags with pretty indentation.

       libimcv.plugins.imc-swima.eid_epoch [0x11223344]
              Set 32 bit epoch value for event IDs manually if software collector database is not available.

       libimcv.plugins.imc-swima.swid_database []
              URI to software collector database containing event timestamps,  software  creation  and  deletion
              events  and  collected  software  identifiers.  If it contains a password, make sure to adjust the
              permissions of the config file accordingly.

       libimcv.plugins.imc-swima.swid_directory [${prefix}/share]
              Directory where SWID tags are located.

       libimcv.plugins.imc-swima.swid_full [no]
              Include file information in the XML-encoded SWID tags.

       libimcv.plugins.imc-swima.swid_pretty [no]
              Generate XML-encoded SWID tags with pretty indentation.

       libimcv.plugins.imc-test.additional_ids [0]
              Number of additional IMC IDs.

       libimcv.plugins.imc-test.command [none]
              Command to be sent to the Test IMV.

       libimcv.plugins.imc-test.dummy_size [0]
              Size of dummy attribute to be sent to the Test IMV (0 = disabled).

       libimcv.plugins.imc-test.retry [no]
              Do a handshake retry.

       libimcv.plugins.imc-test.retry_command []
              Command to be sent to the Test IMV in the handshake retry.

       libimcv.plugins.imv-attestation.cadir []
              Path to directory with AIK cacerts.

       libimcv.plugins.imv-attestation.dh_group [ecp256]
              Preferred Diffie-Hellman group.

       libimcv.plugins.imv-attestation.hash_algorithm [sha256]
              Preferred measurement hash algorithm.

       libimcv.plugins.imv-attestation.mandatory_dh_groups [yes]
              Enforce mandatory Diffie-Hellman groups.

       libimcv.plugins.imv-attestation.min_nonce_len [0]
              DH minimum nonce length.

       libimcv.plugins.imv-os.remediation_uri []
              URI pointing to operating system remediation instructions.

       libimcv.plugins.imv-scanner.remediation_uri []
              URI pointing to scanner remediation instructions.

       libimcv.plugins.imv-swid.rest_api_timeout [120]
              Timeout of SWID REST API HTTP POST transaction.

       libimcv.plugins.imv-swid.rest_api_uri []
              HTTP URI of the SWID REST API.

       libimcv.plugins.imv-swima.rest_api.timeout [120]
              Timeout of SWID REST API HTTP POST transaction.

       libimcv.plugins.imv-swima.rest_api.uri []
              HTTP URI of the SWID REST API.

       libimcv.plugins.imv-test.rounds [0]
              Number of IMC-IMV retry rounds.

       libimcv.stderr_quiet [no]
              Disable output to stderr with a stand-alone libimcv library.

       libimcv.swid_gen.command [/usr/local/bin/swid_generator]
              SWID generator command to be executed.

       libimcv.swid_gen.tag_creator.name [strongSwan Project]
              Name of the tagCreator entity.

       libimcv.swid_gen.tag_creator.regid [strongswan.org]
              regid of the tagCreator entity.

       manager.database []
              Credential database URI for  manager.  If  it  contains  a  password,  make  sure  to  adjust  the
              permissions of the config file accordingly.

       manager.debug [no]
              Enable debugging in manager.

       manager.load []
              Plugins to load in manager.

       manager.socket []
              FastCGI socket of manager, to run it statically.

       manager.threads [10]
              Threads to use for request handling.

       manager.timeout [15m]
              Session timeout for manager.

       medsrv.database []
              Mediation  server  database URI. If it contains a password, make sure to adjust the permissions of
              the config file accordingly.

       medsrv.debug [no]
              Debugging in mediation server web application.

       medsrv.dpd [5m]
              DPD timeout to use in mediation server plugin.

       medsrv.load []
              Plugins to load in mediation server plugin.

       medsrv.password_length [6]
              Minimum password length required for mediation server user accounts.

       medsrv.rekey [20m]
              Rekeying time on mediation connections in mediation server plugin.

       medsrv.socket []
              Run Mediation server web application statically on socket.

       medsrv.threads [5]
              Number of thread for mediation service web application.

       medsrv.timeout [15m]
              Session timeout for mediation service.

       pki.load []
              Plugins to load in ipsec pki tool.

       pool.database []
              Database URI for the database that stores IP pools and configuration attributes.  If it contains a
              password, make        sure to adjust the permissions of the config file accordingly.

       pool.load []
              Plugins to load in ipsec pool tool.

       scepclient.load []
              Plugins to load in ipsec scepclient tool.

       sec-updater
              Options for the sec-updater tool.

       sec-updater.database []
              Global IMV policy database URI. If it contains a password, make sure to adjust the permissions  of
              the config file accordingly.

       sec-updater.load []
              Plugins to load in sec-updater tool.

       sec-updater.swid_gen.command [/usr/local/bin/swid_generator]
              SWID generator command to be executed.

       sec-updater.swid_gen.tag_creator.name [strongSwan Project]
              Name of the tagCreator entity.

       sec-updater.swid_gen.tag_creator.regid [strongswan.org]
              regid of the tagCreator entity.

       sec-updater.tmp.deb_file [/tmp/sec-updater.deb]
              Temporary storage for downloaded deb package file.

       sec-updater.tmp.tag_file [/tmp/sec-updater.tag]
              Temporary storage for generated SWID tags.

       sec-updater.tnc_manage_command [/var/www/tnc/manage.py]
              strongTNC manage.py command used to import SWID tags.

       starter.config_file [${sysconfdir}/ipsec.conf]
              Location of the ipsec.conf file

       starter.load_warning [yes]
              Disable charon plugin load option warning.

       sw-collector
              Options for the sw-collector tool.

       sw-collector.database []
              URI  to  software  collector  database containing event timestamps, software creation and deletion
              events and collected software identifiers. If it contains a password,  make  sure  to  adjust  the
              permissions of the config file accordingly.

       sw-collector.first_file [/var/log/bootstrap.log]
              Path pointing to file created when the Linux OS was installed.

       sw-collector.first_time [0000-00-00T00:00:00Z]
              Time in UTC when the Linux OS was installed.

       sw-collector.history []
              Path pointing to apt history.log file.

       sw-collector.load []
              Plugins to load in sw-collector tool.

       sw-collector.rest_api.timeout [120]
              Timeout of REST API HTTP POST transaction.

       sw-collector.rest_api.uri []
              HTTP URI of the central collector's REST API.

       swanctl.load []
              Plugins to load in swanctl.

       swanctl.socket [unix://${piddir}/charon.vici]
              VICI socket to connect to by default.

LOGGER CONFIGURATION

       Options  in  strongswan.conf(5)  provide a much more flexible way to configure loggers for the IKE daemon
       charon than using the charondebug option in ipsec.conf(5).

       Note: If any loggers are specified in strongswan.conf, charondebug does not have any effect.

       There are currently two types of loggers:

       File loggers
              Log directly to a file and are defined by specifying the full path to the file  as  subsection  in
              the  charon.filelog section. To log to the console the two special filenames stdout and stderr can
              be used.

       Syslog loggers
              Log into a syslog facility and are defined by specifying the facility to log to as the name  of  a
              subsection  in the charon.syslog section. The following facilities are currently supported: daemon
              and auth.

       Multiple loggers can be defined for each type with different log verbosity for the  different  subsystems
       of the daemon.

   Subsystems
       dmn    Main daemon setup/cleanup/signal handling

       mgr    IKE_SA manager, handling synchronization for IKE_SA access

       ike    IKE_SA

       chd    CHILD_SA

       job    Jobs queueing/processing and thread pool management

       cfg    Configuration management and plugins

       knl    IPsec/Networking kernel interface

       net    IKE network communication

       asn    Low-level encoding/decoding (ASN.1, X.509 etc.)

       enc    Packet encoding/decoding encryption/decryption operations

       tls    libtls library messages

       esp    libipsec library messages

       lib    libstrongwan library messages

       tnc    Trusted Network Connect

       imc    Integrity Measurement Collector

       imv    Integrity Measurement Verifier

       pts    Platform Trust Service

   Loglevels
       -1     Absolutely silent

       0      Very basic auditing logs, (e.g. SA up/SA down)

       1      Generic control flow with errors, a good default to see whats going on

       2      More detailed debugging control flow

       3      Including RAW data dumps in Hex

       4      Also include sensitive material in dumps, e.g. keys

   Example
            charon {
                 filelog {
                      /var/log/charon.log {
                           time_format = %b %e %T
                           append = no
                           default = 1
                      }
                      stderr {
                           ike = 2
                           knl = 3
                           ike_name = yes
                      }
                 }
                 syslog {
                      # enable logging to LOG_DAEMON, use defaults
                      daemon {
                      }
                      # minimalistic IKE auditing logging to LOG_AUTHPRIV
                      auth {
                           default = -1
                           ike = 0
                      }
                 }
            }

JOB PRIORITY MANAGEMENT

       Some  operations  in  the  IKEv2  daemon charon are currently implemented synchronously and blocking. Two
       examples for such operations are communication with a RADIUS server via EAP-RADIUS, or fetching  CRL/OCSP
       information  during  certificate  chain verification. Under high load conditions, the thread pool may run
       out of available threads, and some more important jobs, such as liveness checking, may not  get  executed
       in time.

       To  prevent  thread starvation in such situations job priorities were introduced.  The job processor will
       reserve some threads for higher priority jobs, these  threads  are  not  available  for  lower  priority,
       locking jobs.

   Implementation
       Currently 4 priorities have been defined, and they are used in charon as follows:

       CRITICAL
              Priority for long-running dispatcher jobs.

       HIGH   INFORMATIONAL exchanges, as used by liveness checking (DPD).

       MEDIUM Everything not HIGH/LOW, including IKE_SA_INIT processing.

       LOW    IKE_AUTH message processing. RADIUS and CRL fetching block here

       Although  IKE_SA_INIT  processing  is  computationally expensive, it is explicitly assigned to the MEDIUM
       class. This allows charon to do the DH exchange while other threads are blocked in IKE_AUTH.  To  prevent
       the daemon from accepting more IKE_SA_INIT requests than it can handle, use IKE_SA_INIT DROPPING.

       The  thread  pool  processes  jobs strictly by priority, meaning it will consume all higher priority jobs
       before looking for ones with lower priority. Further, it  reserves  threads  for  certain  priorities.  A
       priority  class  having  reserved  n  threads will always have n threads available for this class (either
       currently processing a job, or waiting for one).

   Configuration
       To ensure that there are always enough threads available for  higher  priority  tasks,  threads  must  be
       reserved for each priority class.

       charon.processor.priority_threads.critical [0]
              Threads reserved for CRITICAL priority class jobs

       charon.processor.priority_threads.high [0]
              Threads reserved for HIGH priority class jobs

       charon.processor.priority_threads.medium [0]
              Threads reserved for MEDIUM priority class jobs

       charon.processor.priority_threads.low [0]
              Threads reserved for LOW priority class jobs

       Let's consider the following configuration:

            charon {
                 processor {
                      priority_threads {
                           high = 1
                           medium = 4
                      }
                 }
            }

       With  this  configuration,  one  thread  is  reserved for HIGH priority tasks. As currently only liveness
       checking and stroke message processing is  done  with  high  priority,  one  or  two  threads  should  be
       sufficient.

       The  MEDIUM  class  mostly  processes non-blocking jobs. Unless your setup is experiencing many blocks in
       locks while accessing shared resources, threads for one or two times the number of CPU cores is fine.

       It is usually not required to reserve threads for CRITICAL jobs. Jobs in this class rarely return and  do
       not release their thread to the pool.

       The  remaining  threads are available for LOW priority jobs. Reserving threads does not make sense (until
       we have an even lower priority).

   Monitoring
       To see what the threads are actually doing, invoke ipsec statusall.  Under high load, something like this
       will show up:

            worker threads: 2 or 32 idle, 5/1/2/22 working,
                 job queue: 0/0/1/149, scheduled: 198

       From 32 worker threads,

       2      are currently idle.

       5      are running CRITICAL priority jobs (dispatching from sockets, etc.).

       1      is currently handling a HIGH priority job. This is actually the thread  currently  providing  this
              information via stroke.

       2      are handling MEDIUM priority jobs, likely IKE_SA_INIT or CREATE_CHILD_SA messages.

       22     are  handling  LOW  priority  jobs,  probably  waiting for an EAP-RADIUS response while processing
              IKE_AUTH messages.

       The job queue load shows how many jobs are queued for each priority,  ready  for  execution.  The  single
       MEDIUM priority job will get executed immediately, as we have two spare threads reserved for MEDIUM class
       jobs.

IKE_SA_INIT DROPPING

       If  a  responder receives more connection requests per seconds than it can handle, it does not make sense
       to accept more IKE_SA_INIT messages. And if they are queued but can't get processed in  time,  an  answer
       might be sent after the client has already given up and restarted its connection setup. This additionally
       increases the load on the responder.

       To  limit  the  responder  load  resulting  from new connection attempts, the daemon can drop IKE_SA_INIT
       messages just after reception. There are two mechanisms to decide if this should happen, configured  with
       the following options:

       charon.init_limit_half_open [0]
              Limit based on the number of half open IKE_SAs. Half open IKE_SAs are SAs in connecting state, but
              not yet established.

       charon.init_limit_job_load [0]
              Limit based on the number of jobs currently queued for processing (sum over all job priorities).

       The  second limit includes load from other jobs, such as rekeying. Choosing a good value is difficult and
       depends on the hardware and expected load.

       The first limit is simpler to calculate, but includes  the  load  from  new  connections  only.  If  your
       responder is capable of negotiating 100 tunnels/s, you might set this limit to 1000. The daemon will then
       drop  new  connection  attempts  if  generating a response would require more than 10 seconds. If you are
       allowing for a maximum response time of  more  than  30  seconds,  consider  adjusting  the  timeout  for
       connecting  IKE_SAs  (charon.half_open_timeout).   A  responder,  by  default,  deletes  an IKE_SA if the
       initiator does not establish it within 30 seconds. Under high load, a higher value might be required.

LOAD TESTS

       To do stability testing and performance optimizations, the IKE daemon  charon  provides  the  load-tester
       plugin.  This plugin allows one to setup thousands of tunnels concurrently against the daemon itself or a
       remote host.

       WARNING:  Never  enable  the  load-testing  plugin  on  productive  systems.  It  provides  preconfigured
       credentials and allows an attacker to authenticate as any user.

   Configuration details
       For  public key authentication, the responder uses the "CN=srv, OU=load-test, O=strongSwan" identity. For
       the initiator, each connection attempt uses a different identity in  the  form  "CN=c1-r1,  OU=load-test,
       O=strongSwan",  where  the first number inidicates the client number, the second the authentication round
       (if multiple authentication rounds are used).

       For PSK authentication, FQDN identities are used. The server uses srv.strongswan.org, the client uses  an
       identity in the form c1-r1.strongswan.org.

       For EAP authentication, the client uses a NAI in the form 100000000010001@strongswan.org.

       To configure multiple authentication rounds, concatenate multiple methods using, e.g.
            initiator_auth = pubkey|psk|eap-md5|eap-aka

       The  responder  uses  a hardcoded certificate based on a 1024-bit RSA key.  This certificate additionally
       serves as CA certificate. A peer uses the same private key, but generates client certificates  on  demand
       signed by the CA certificate. Install the Responder/CA certificate on the remote host to authenticate all
       clients.

       To  speed  up  testing,  the load tester plugin implements a special Diffie-Hellman implementation called
       modpnull. By setting
            proposal = aes128-sha1-modpnull
       this wicked fast DH implementation is used. It does not provide any security at all, but  allows  one  to
       run tests without DH calculation overhead.

   Examples
       In the simplest case, the daemon initiates IKE_SAs against itself using the loopback interface. This will
       actually establish double the number of IKE_SAs, as the daemon is initiator and responder for each IKE_SA
       at the same time.  Installation of IPsec SAs would fail, as each SA gets installed twice. To simulate the
       correct  behavior,  a  fake  kernel  interface can be enabled which does not install the IPsec SAs at the
       kernel level.

       A simple loopback configuration might look like this:

            charon {
                 # create new IKE_SAs for each CHILD_SA to simulate
                 # different clients
                 reuse_ikesa = no
                 # turn off denial of service protection
                 dos_protection = no

                 plugins {
                      load-tester {
                           # enable the plugin
                           enable = yes
                           # use 4 threads to initiate connections
                           # simultaneously
                           initiators = 4
                           # each thread initiates 1000 connections
                           iterations = 1000
                           # delay each initiation in each thread by 20ms
                           delay = 20
                           # enable the fake kernel interface to
                           # avoid SA conflicts
                           fake_kernel = yes
                      }
                 }
            }

       This will initiate 4000 IKE_SAs within 20 seconds. You may increase the delay value if your box  can  not
       handle  that  much  load,  or  decrease  it  to  put more load on it. If the daemon starts retransmitting
       messages your box probably can not handle all connection attempts.

       The plugin also allows one to test against a remote host. This might help to test against  a  real  world
       configuration. A connection setup to do stress testing of a gateway might look like this:

            charon {
                 reuse_ikesa = no
                 threads = 32

                 plugins {
                      load-tester {
                           enable = yes
                           # 10000 connections, ten in parallel
                           initiators = 10
                           iterations = 1000
                           # use a delay of 100ms, overall time is:
                           # iterations * delay = 100s
                           delay = 100
                           # address of the gateway
                           remote = 1.2.3.4
                           # IKE-proposal to use
                           proposal = aes128-sha1-modp1024
                           # use faster PSK authentication instead
                           # of 1024bit RSA
                           initiator_auth = psk
                           responder_auth = psk
                           # request a virtual IP using configuration
                           # payloads
                           request_virtual_ip = yes
                           # enable CHILD_SA every 60s
                           child_rekey = 60
                      }
                 }
            }

IKEv2 RETRANSMISSION

       Retransmission timeouts in the IKEv2 daemon charon can be configured globally using the three keys listed
       below:

              charon.retransmit_base [1.8]
              charon.retransmit_timeout [4.0]
              charon.retransmit_tries [5]
              charon.retransmit_jitter [0]
              charon.retransmit_limit [0]

       The following algorithm is used to calculate the timeout:

            relative timeout = retransmit_timeout * retransmit_base ^ (n-1)

       Where  n  is  the  current  retransmission  count.  The  calculated  timeout  can't exceed the configured
       retransmit_limit (if any), which is useful if the number of retries is high.

       If a jitter in percent is configured, the timeout is modified as follows:

            relative timeout -= random(0, retransmit_jitter * relative timeout)

       Using the default values, packets are retransmitted in:

       Retransmission   Relative Timeout   Absolute Timeout
       ─────────────────────────────────────────────────────
       1                              4s                 4s
       2                              7s                11s
       3                             13s                24s
       4                             23s                47s
       5                             42s                89s
       giving up                     76s               165s

VARIABLES

       The variables used above are configured as follows:

       ${piddir}               /var/run
       ${prefix}               /usr
       ${random_device}        /dev/random
       ${urandom_device}       /dev/urandom

FILES

       /etc/strongswan.conf       configuration file
       /etc/strongswan.d/         directory containing included config snippets
       /etc/strongswan.d/charon/  plugin specific config snippets

SEE ALSO

       ipsec.conf(5), ipsec.secrets(5), ipsec(8), charon-cmd(8)

HISTORY

       Written for the strongSwan project by Tobias Brunner, Andreas Steffen and Martin Willi.

5.6.2                                                                                         STRONGSWAN.CONF(5)