Provided by: libstrongswan_5.7.2-1ubuntu3_amd64 bug


       strongswan.conf - strongSwan configuration file


       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


       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.

       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.


       It is possible to inherit settings and sections from  another  section.  This  feature  is
       mainly  useful  in  swanctl.conf  (which  uses  the  same  file format).  The syntax is as

            section    := name : references { settings }
            references := absname[, absname]*
            absname    := name[.name]*

       All key/value pairs and all subsections of the referenced sections will  be  inherited  by
       the  section that references them via their absolute name. Values may be overridden in the
       section or any of its sub-sections (use an empty  assignment  to  clear  a  value  so  its
       default  value,  if  any, will apply). It is currently not possible to limit the inclusion
       level or clear/remove inherited sub-sections.

       If the order is important (e.g. for auth rounds in a connection, if round is not used), it
       should  be noted that inherited settings/sections will follow those defined in the current
       section (if multiple sections are  referenced,  their  settings  are  enumerated  left  to

       References  are  evaluated  dynamically  at runtime, so referring to sections later in the
       config file or included via other files is no problem.

       Here is an example of how this might look like:

            conn-defaults {
                 # default settings for all conns (e.g. a cert, or IP pools)
            eap-defaults {
                 # defaults if eap is used (e.g. a remote auth round)
            child-defaults {
                 # defaults for child configs (e.g. traffic selectors)
            connections {
                 conn-a : conn-defaults, eap-defaults {
                      # set/override stuff specific to this connection
                      children {
                           child-a : child-defaults {
                                # set/override stuff specific to this child
                 conn-b : conn-defaults {
                      # set/override stuff specific to this connection
                      children {
                           child-b : child-defaults {
                                # set/override stuff specific to this child
                 conn-c : connections.conn-a {
                      # everything is inherited, including everything conn-a
                      # already inherits from the sections it and its
                      # sub-section reference


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

            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

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

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

            # this extends section-one and subsection
            section-one {
                 subsection {
                      # this replaces the previous value
                      othervalue = xxx
            section-two {
                 x = 12


       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.


       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.

              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

              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),

       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]
              Time in ms during which crypto algorithm performance is measured.

       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.

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

              <name>  may  be  the  full  path  to  the  log  file if it only contains characters
              permitted in section names. Is ignored if path is specified.

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

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

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

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

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

       charon.filelog.<name>.path []
              Optional path to the log file. Overrides the section name. Must be used if the path
              contains characters that aren't allowed in section names.

       charon.filelog.<name>.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.<name>.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. []
              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.

              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 []
              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

       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.

              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
     as that would be routed via loopback. Setting this option  to  yes
              and configuring the local broadcast address (e.g. as server address
              might work.

       charon.plugins.dhcp.identity_lease [no]
              Derive user-defined MAC address from hash of IKE identity and send client  identity
              DHCP option.

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

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

       charon.plugins.dhcp.use_server_port [no]
              Use the DHCP server port (67) as source port, instead of the DHCP client port (68),
              when a unicast server address is configured and the plugin  acts  as  relay  agent.
              When  replying  in  this  mode the DHCP server will always send packets to the DHCP
              server port and if no process binds that port an ICMP  port  unreachables  will  be
              sent  back,  which  might  be  problematic  for  some DHCP servers.  To avoid that,
              enabling this option will cause the plugin to bind the DHCP server port to send its
              requests  when  acting  as  relay  agent. This is not necessary if a DHCP server is
              already running on the same host and might even  cause  conflicts  (and  since  the
              server port is already bound, ICMPs should not be an issue).

       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

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

       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

       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 []
              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

       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.

              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.station_id_with_port [yes]
              Whether to include the UDP  port  in  the  Called-  and  Calling-Station-Id  RADIUS

              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

              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.

              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

       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.

              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

       charon.plugins.kernel-pfkey.route_via_internal [no]
              Whether to use the internal or external interface in installed routes. The internal
              interface is the one where the IP address contained in the local  traffic  selector
              is located, the external interface is the one over which the destination address of
              the IPsec tunnel can be reached. This is not relevant if virtual IPs are used,  for
              which a TUN device is created that's used in the routes.

       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]

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

              Section that contains key/value pairs with address pools (in CIDR notation) to  use
              for a specific network interface e.g. eth0 =

       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

       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 []
              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

       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 []
              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

       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

       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.

              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.

              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. [no]
              Whether to save ESP keys. [no]
              Whether to save IKE keys. [no]
              Whether to load the plugin. []
              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

       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). [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.fips_186_4 [no]
              Is  the  TPM  2.0  FIPS-186-4  compliant,  forcing e.g. the use of the default salt
              length instead of maximum salt length with RSAPSS padding. [device|tabrmd]
              Name of TPM 2.0 TCTI library. Valid values: tabrmd, device or mssim.  Defaults  are
              device  if  the  /dev/tpmrm0  in-kernel TPM 2.0 resource manager device exists, and
              tabrmd otherwise, requiring the d-bus based TPM  2.0  access  broker  and  resource
              manager to be available.

       charon.plugins.tpm.tcti.opts [/dev/tpmrm0|<none>]
              Options  for the TPM 2.0 TCTI library. Defaults are /dev/tpmrm0 if the TCTI library
              name is device and no options otherwise.

       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

       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

       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

       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.

              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

       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.

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

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

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

              <facility> is one of the supported syslog facilities, see LOGGER  CONFIGURATION  in

       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.

              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

       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

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

       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.

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

       libimcv.plugins.imc-swima.subscriptions [no]
              Accept SW Inventory or SW Events subscriptions.

       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-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. [strongSwan Project]
              Name of the tagCreator entity.

       libimcv.swid_gen.tag_creator.regid []
              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.

              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. [strongSwan Project]
              Name of the tagCreator entity.

       sec-updater.swid_gen.tag_creator.regid []
              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/]
              strongTNC 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.

              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.


       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

       There are currently two types of loggers:

       File loggers
              Log directly to  a  file  and  are  defined  by  specifying  an  arbitrarily  named
              subsection  in  the charon.filelog section. The full path to the file is configured
              in the path setting of that subsection, however, if  it  only  contains  characters
              permitted  in section names, the setting may also be omitted and the path specified
              as name of the subsection. To log to the console the two special  filenames  stdout
              and stderr may 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.

       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

       -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 what's 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

            charon {
                 filelog {
                      charon {
                           path = /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


       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.

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

              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).

       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).

       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.


       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

       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


       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  indicates  the  client
       number, the second the authentication round (if multiple authentication rounds are used).

       For  PSK authentication, FQDN identities are used. The server uses, the
       client uses an identity in the form

       For EAP authentication, the client uses a NAI in the form

       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.

       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

       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 =
                           # 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


       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


       The variables used above are configured as follows:

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


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


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


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