Provided by: libstrongswan_5.9.6-1ubuntu2_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_private_algs [no]
              Deliberately  violate  the  IKE standard's requirement and allow the use of private
              algorithm identifiers, even if the peer implementation is unknown.

       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  (including  unprocessed  IKE_SA_INITs)  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.check_current_path [no]
              By default, after detecting any changes to interfaces and/or addresses no action is
              taken  if  the  current  path  to the remote peer still looks usable. Enabling this
              option will use DPD to check if the path actually still works,  or,  for  instance,
              the peer removed the state after a longer phase without connectivity.  It will also
              trigger a MOBIKE update if NAT mappings were removed during the downtime.

       charon.cisco_flexvpn [no]
              Send the Cisco FlexVPN vendor ID payload, which is required in order to make  Cisco
              brand  devices  allow negotiating a local traffic selector (from strongSwan's point
              of view) that is not the  assigned  virtual  IP  address  if  such  an  address  is
              requested  by    strongSwan.  Sending the Cisco FlexVPN vendor ID prevents the peer
              from narrowing the initiator's  local  traffic  selector  and  allows  it  to  e.g.
              negotiate  a  TS  of  == instead.  This has been tested with a
              "tunnel mode ipsec ipv4" Cisco template but should also work for GRE encapsulation.

       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 [30]
              Number of half-open IKE_SAs (including unprocessed IKE_SA_INITs) that activate  the
              cookie mechanism.

       charon.cookie_threshold_ip [3]
              Number  of half-open IKE_SAs (including unprocessed IKE_SA_INITs) for a single peer
              IP 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.

              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>.log_level [no]
              Add the log level of each message after the subsystem (e.g. [IKE2]).

       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.force_eap_only_authentication [no]
              Violate  RFC  5998 and use EAP-only authentication even if the peer did not send an
              EAP_ONLY_AUTHENTICATION notify during IKE_AUTH.

       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.keep_alive_dpd_margin [0s]
              Number  of  seconds  the  keep  alive interval may be exceeded before a DPD is sent
              instead of a NAT keep alive (0 to disable).  This is only useful if a clock is used
              that includes time spent suspended (e.g. CLOCK_BOOTTIME).

       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.plugins.addrblock.depth [-1]
              RFC3779  requires that all addrblocks claimed by a certificate must be contained in
              the addrblock extension of the issuer certificate, up to the root CA.  The  default
              depth setting of -1 enforces this.

              In  practice,  third  party  (root)  CAs  may not contain the extension, making the
              addrblock extension unusable under such CAs. By limiting the validation depth, only
              a  certain  level  of  issuer  certificates  are  validated  for  proper  addrblock
              extensions: A depth of 0 does not check any issuer certificate extensions, a  depth
              of 1 only the direct issuer of the end entity certificate is checkend, and so on.

       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.botan.internal_rng_only [no]
              If  enabled,  only  Botan's  internal  RNG  will  be  used  throughout  the plugin.
              Otherwise, and if supported by  Botan,  rng_t  implementations  provided  by  other
              loaded plugins will be used as RNG.

       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.drbg.max_drbg_requests [4294967294]
              Number of pseudo-random bit requests from the DRBG before  an  automatic  reseeding

       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.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.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.hw_offload_feature_interface [lo]
              If  the  kernel  supports hardware offloading, the plugin needs to find the feature
              flag which represents hardware offloading support for network  devices.  Using  the
              loopback  device  for  this  purpose  is  usually  fine,  since it should always be
              present. For rare cases in which the loopback device cannot be used to  obtain  the
              appropriate  feature  flag,  this  option  can  be  used  to specify an alternative
              interface for offload feature detection.

       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.mtu [1400]
              MTU to set on TUN devices created for virtual IPs.

       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 initiations 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 initiator 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 and INTERNAL_IPV6_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.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.   With  OpenSSL  before  3.0,  the  supported  values are
              disabled(0), enabled(1) and Suite B enabled(2).  With OpenSSL 3+, any  value  other
              than  0  will  explicitly  load  the  fips  and base providers (load_legacy will be
              ignored). The latter still requires the config in  fipsmodule.cnf  (e.g.   for  the
              module's  MAC), but allows explicitly loading the provider if it's not activated in
              that config.

       charon.plugins.openssl.load_legacy [yes]
              Load the legacy provider in OpenSSL 3+ for algorithms like MD4,  DES,  or  Blowfish
              (the first two are required for EAP-MSCHAPv2). If disabled, the default provider is
              loaded, or those configured in the OpenSSL config (e.g. the fips provider).

       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.ek_handle []
              Handle of the RSA or ECC Endorsement Key (EK) to be used to set up an authenticated
              session with a TPM 2.0 (e.g. 0x81010001).

       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. For  security  reasons  enable  only  if  an
              authenticated session can be set up (see ek_handle option).

       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.wolfssl.fips_mode [no]
              Enable to prevent loading the plugin if wolfSSL is not in FIPS mode.

       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, permanent IPv6 source addresses are preferred over temporary ones (RFC
              4941), to make connections more stable. Enable this option to reverse this.

              It also affects which IPv6 addresses  are  announced  as  additional  addresses  if
              MOBIKE  is used.  If the option is disabled, only permanent addresses are sent, and
              only temporary ones if it is enabled.

       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.rdn_matching [strict]
              How  RDNs in subject DNs of certificates are matched against configured identities.
              Possible values are strict (the default), reordered, and relaxed.  With strict  the
              number,  type  and  order of all RDNs has to match, wildcards (*) for the values of
              RDNs are allowed (that's the case for all three  variants).  Using  reordered  also
              matches  DNs if the RDNs appear in a different order, the number and type still has
              to match. Finally, relaxed also allows matches of DNs that contain more  RDNs  than
              the configured identity (missing RDNs are treated like a wildcard match).

              Note  that reordered and relaxed impose a considerable overhead on memory usage and
              runtime, in particular, for mismatches, compared to strict.

       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_label [0x0000000000000000]
              Value mixed into the local IKE SPIs after applying spi_mask.

       charon.spi_mask [0x0000000000000000]
              Mask  applied  to  local  IKE  SPIs  before  mixing  in spi_label (bits set will be
              replaced with spi_label).

       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.<facility>.log_level [no]
              Add the log level of each message after the subsystem (e.g. [IKE2]).

       charon.syslog.<facility>.map_level [-1]
              The default setting of -1 passes all messages  to  syslog  using  a  log  level  of
              LOG_INFO. A non-negative value maps the strongSwan specific loglevels (0..4) to the
              syslog level  starting  at  the  specified  number.  For  example,  a  value  of  5
              (LOG_NOTICE)  maps  strongSwan  loglevel  0 to LOG_NOTICE, level 1 to LOG_INFO, and
              levels 2, 3 and 4 to LOG_DEBUG. This allows (additional) filtering of log  messages
              on the syslog server.

       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.ke_group []
              List of TLS key exchange groups.

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

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

       charon.tls.send_certreq_authorities [yes]
              Whether to include CAs in a server's CertificateRequest message. May be disabled if
              clients can't handle a long list of CAs.

       charon.tls.signature []
              List of TLS signature schemes.

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

       charon.tls.version_max [1.2]
              Maximum TLS version to negotiate.

       charon.tls.version_min [1.2]
              Minimum TLS version to negotiate.

       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.hash_algorithm [sha384]
              Preferred measurement hash algorithm.

       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.pcr_padding [no]
              Whether to pad IMA SHA1 measurements values when extending into SHA256 PCR bank.

       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 [sha384]
              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    libstrongswan 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.