Provided by: strongswan_4.2.9-1_i386 bug

NAME

       ipsec pluto - IPsec IKE keying daemon
       ipsec whack - control interface for IPSEC keying daemon

SYNOPSIS

       ipsec pluto [--help] [--version] [--optionsfrom filename] [--nofork]
              [--stderrlog] [--noklips] [--uniqueids] [--interface
              interfacename] [--ikeport portnumber] [--ctlbase path]
              [--secretsfile secretsfile] [--adns pathname] [--lwdnsq
              pathname] [--perpeerlog] [--perpeerlogbase dirname]
              [--debugnone] [--debugall] [--debugraw] [--debugcrypt]
              [--debugparsing] [--debugemitting] [--debugcontrol]
              [--debuglifecycle] [--debugklips] [--debugdns] [--debugoppo]
              [--debugprivate]

       ipsec whack [--help] [--version]

       ipsec whack --name connection-name
              [--id id] [--host ipaddress] [--ikeport portnumber]
              [--nexthop ipaddress] [--client subnet] [--dnskeyondemand]
              [--updown updown]
              --to
              [--id id] [--host ipaddress] [--ikeport portnumber]
              [--nexthop ipaddress] [--client subnet] [--dnskeyondemand]
              [--updown updown]
              [--psk] [--rsasig] [--encrypt] [--authenticate] [--compress]
              [--tunnel] [--pfs] [--disablearrivalcheck] [--ipv4] [--ipv6]
              [--tunnelipv4] [--tunnelipv6] [--ikelifetime seconds]
              [--ipseclifetime seconds] [--rekeymargin seconds]
              [--rekeyfuzz percentage] [--keyingtries count] [--dontrekey]
              [--delete] [--ctlbase path] [--optionsfrom filename]
              [--label string]

       ipsec whack --keyid id [--addkey] [--pubkeyrsa key] [--ctlbase path]
              [--optionsfrom filename] [--label string]

       ipsec whack --myid id

       ipsec whack --listen|--unlisten [--ctlbase path]
              [--optionsfrom filename] [--label string]

       ipsec whack --route|--unroute --name connection-name [--ctlbase path]
              [--optionsfrom filename] [--label string]

       ipsec whack --initiate|--terminate --name connection-name
              [--asynchronous] [--ctlbase path] [--optionsfrom filename]
              [--label string]

       ipsec whack [--tunnelipv4] [--tunnelipv6] --oppohere ipaddress
              --oppothere ipaddress

       ipsec whack --delete --name connection-name [--ctlbase path]
              [--optionsfrom filename] [--label string]

       ipsec whack --deletestate state-number [--ctlbase path]
              [--optionsfrom filename] [--label string]

       ipsec whack [--name connection-name] [--debugnone] [--debugall]
              [--debugraw] [--debugcrypt] [--debugparsing]
              [--debugemitting] [--debugcontrol] [--debuglifecycle]
              [--debugklips] [--debugdns] [--debugoppo] [--debugprivate]
              [--ctlbase path] [--optionsfrom filename] [--label string]

       ipsec whack --status [--ctlbase path] [--optionsfrom filename]
              [--label string]

       ipsec whack --shutdown [--ctlbase path] [--optionsfrom filename]
              [--label string]

DESCRIPTION

       pluto is an IKE (‘‘IPsec Key Exchange’’) daemon.  whack is an auxiliary
       program to allow requests to be made to a running pluto.

       pluto is used to automatically build shared  ‘‘security  associations’’
       on  a  system  that has IPsec, the secure IP protocol.  In other words,
       pluto can eliminate much of the work  of  manual  keying.   The  actual
       secure  transmission of packets is the responsibility of other parts of
       the  system  (see  KLIPS,  the  companion  implementation  of   IPsec).
       ipsec_auto(8)  provides a more convenient interface to pluto and whack.

   IKEs Job
       A Security Association (SA) is an agreement between two  network  nodes
       on  how  to  process  certain  traffic  between  them.  This processing
       involves encapsulation, authentication, encryption, or compression.

       IKE  can  be  deployed  on  a  network  node  to   negotiate   Security
       Associations  for  that  node.   These  IKE  implementations  can  only
       negotiate with other IKE implementations, so IKE must be on  each  node
       that  is  to  be an endpoint of an IKE-negotiated Security Association.
       No other nodes need to be running IKE.

       An IKE instance (i.e. an IKE implementation  on  a  particular  network
       node)  communicates  with another IKE instance using UDP IP packets, so
       there must be a route between the nodes in each direction.

       The negotiation of Security Associations requires a number  of  choices
       that  involve  tradeoffs  between  security,  convenience,  trust,  and
       efficiency.  These are policy issues and are normally specified to  the
       IKE instance by the system administrator.

       IKE deals with two kinds of Security Associations.  The first part of a
       negotiation between IKE instances is to build an ISAKMP SA.  An  ISAKMP
       SA  is  used  to protect communication between the two IKEs.  IPsec SAs
       can then be built by the IKEs - these are used to  carry  protected  IP
       traffic between the systems.

       The negotiation of the ISAKMP SA is known as Phase 1.  In theory, Phase
       1 can be accomplished by a couple of different exchange types,  but  we
       only  implement  one  called  Main  Mode (we don’t implement Aggressive
       Mode).

       Any negotiation under the protection of an  ISAKMP  SA,  including  the
       negotiation  of  IPsec SAs, is part of Phase 2.  The exchange type that
       we use to negotiate an IPsec SA is called Quick Mode.

       IKE instances must be able to authenticate each other as part of  their
       negotiation  of  an  ISAKMP SA.  This can be done by several mechanisms
       described in the draft standards.

       IKE negotiation can be initiated by any instance with  any  other.   If
       both  can  find  an  agreeable  set  of  characteristics for a Security
       Association, and both recognize each others authenticity, they can  set
       up a Security Association.  The standards do not specify what causes an
       IKE instance to initiate a negotiation.

       In summary, an IKE instance is prepared to automate the  management  of
       Security  Associations  in an IPsec environment, but a number of issues
       are considered policy and are left in the system administrator’s hands.

   Pluto
       pluto  is  an  implementation of IKE.  It runs as a daemon on a network
       node.  Currently, this network node must be a LINUX system running  the
       KLIPS implementation of IPsec.

       pluto  only  implements  a  subset  of  IKE.   This is enough for it to
       interoperate  with  other  instances  of  pluto,  and  many  other  IKE
       implementations.  We are working on implementing more of IKE.

       The  policy for acceptable characteristics for Security Associations is
       mostly hardwired into the code of pluto (spdb.c).  Eventually this will
       be  moved  into  a  security policy database with reasonable expressive
       power and more convenience.

       pluto uses shared secrets or RSA signatures to authenticate peers  with
       whom it is negotiating.

       pluto  initiates  negotiation  of  a  Security  Association  when it is
       manually prodded: the program whack is run to trigger  this.   It  will
       also  initiate  a  negotiation  when KLIPS traps an outbound packet for
       Opportunistic Encryption.

       pluto implements ISAKMP  SAs  itself.   After  it  has  negotiated  the
       characteristics  of  an IPsec SA, it directs KLIPS to implement it.  It
       also invokes a  script  to  adjust  any  firewall  and  issue  route(8)
       commands to direct IP packets through KLIPS.

       When pluto shuts down, it closes all Security Associations.

   Before Running Pluto
       pluto  runs  as  a  daemon  with userid root.  Before running it, a few
       things must be set up.

       pluto requires KLIPS, the FreeS/WAN implementation of  IPsec.   All  of
       the components of KLIPS and pluto should be installed.

       pluto  supports  multiple  public  networks (that is, networks that are
       considered insecure and thus need to have their  traffic  encrypted  or
       authenticated).   It  discovers the public interfaces to use by looking
       at all interfaces that are configured (the --interface  option  can  be
       used to limit the interfaces considered).  It does this only when whack
       tells it to --listen, so the interfaces must  be  configured  by  then.
       Each  interface  with a name of the form ipsec[0-9] is taken as a KLIPS
       virtual public interface.  Another network interface with the  same  IP
       address  (there  should be only one) is taken as the corresponding real
       public interface.  ifconfig(8) with the -a flag will show the name  and
       status of each network interface.

       pluto  requires  a  database of preshared secrets and RSA private keys.
       This is described in the ipsec.secrets(5).  pluto is told of RSA public
       keys  via  whack  commands.  If the connection is Opportunistic, and no
       RSA public key is known, pluto will attempt to fetch RSA keys using the
       Domain Name System.

   Setting up KLIPS for pluto
       The  most  basic  network topology that pluto supports has two security
       gateways negotiating on behalf of client subnets.  The diagram of RGB’s
       testbed is a good example (see klips/doc/rgb_setup.txt).

       The  file  INSTALL  in the base directory of this distribution explains
       how to start setting up the whole system, including KLIPS.

       Make sure that the security gateways have routes to each  other.   This
       is  usually  covered  by  the  default  route,  but may require issuing
       route(8) commands.  The route must go through a particular IP interface
       (we  will  assume  it is eth0, but it need not be).  The interface that
       connects the security gateway to its client must be a different one.

       It is necessary to issue a ipsec_tncfg(8) command on each gateway.  The
       required command is:

          ipsec tncfg --attach --virtual ipsec0 --physical eth0

       A  command  to set up the ipsec0 virtual interface will also need to be
       run.  It will have the same parameters as the command used  to  set  up
       the  physical  interface  to  which  it  has  just been connected using
       ipsec_tncfg(8).

   ipsec.secrets file
       A pluto daemon and another IKE daemon (for example, another instance of
       pluto)  must convince each other that they are who they are supposed to
       be  before  any  negotiation  can  succeed.   This  authentication   is
       accomplished  by  using either secrets that have been shared beforehand
       (manually) or by using RSA signatures.  There are other techniques, but
       they have not been implemented in pluto.

       The  file  /etc/ipsec.secrets is used to keep preshared secret keys and
       RSA private keys  for  authentication  with  other  IKE  daemons.   For
       debugging, there is an argument to the pluto command to use a different
       file.  This file is described in ipsec.secrets(5).

   Running Pluto
       To fire up the daemon, just type pluto (be sure to be  running  as  the
       superuser).   The default IKE port number is 500, the UDP port assigned
       by IANA for IKE Daemons.  pluto must be run by the superuser to be able
       to use the UDP 500 port.

       pluto  attempts  to create a lockfile with the name /var/run/pluto.pid.
       If the lockfile cannot be created, pluto exits - this prevents multiple
       plutos from competing  Any ‘‘leftover’’ lockfile must be removed before
       pluto will run.  pluto writes its pid into this file  so  that  scripts
       can  find  it.  This lock will not function properly if it is on an NFS
       volume (but sharing locks  on  multiple  machines  doesn’t  make  sense
       anyway).

       pluto  then  forks  and  the  parent  exits.   This is the conventional
       ‘‘daemon fork’’.  It can make debugging awkward, so there is an  option
       to suppress this fork.

       All   logging,   including  diagnostics,  is  sent  to  syslog(3)  with
       facility=authpriv; it decides where to put these messages (possibly  in
       /var/log/secure).   Since this too can make debugging awkward, there is
       an option to steer logging to stderr.

       If the --perpeerlog option is given, then pluto will open  a  log  file
       per  connection.  By  default,  this  is  in  /var/log/pluto/peer, in a
       subdirectory formed by turning all dot (.) [IPv4} or colon  (:)  [IPv6]
       into slashes (/).

       The base directory can be changed with the --perpeerlogbase.

       Once pluto is started, it waits for requests from whack.

   Plutos Internal State
       To  understand  how  to use pluto, it is helpful to understand a little
       about its internal state.  Furthermore, the terminology  is  needed  to
       decipher some of the diagnostic messages.

       The   (potential)   connection   database  describes  attributes  of  a
       connection.  These include the IP addresses of  the  hosts  and  client
       subnets  and the security characteristics desired.  pluto requires this
       information (simply called a connection) before it  can  respond  to  a
       request  to  build  an  SA.  Each connection is given a name when it is
       created, and all references are made using this name.

       During the IKE exchange to build  an  SA,  the  information  about  the
       negotiation  is  represented  in  a  state  object.   Each state object
       reflects how far the negotiation has reached.  Once the negotiation  is
       complete  and the SA established, the state object remains to represent
       the SA.  When the SA is terminated,  the  state  object  is  discarded.
       Each State object is given a serial number and this is used to refer to
       the state objects in logged messages.

       Each state object corresponds to a connection and can be thought of  as
       an instantiation of that connection.  At any particular time, there may
       be  any  number  of  state  objects  corresponding  to   a   particular
       connection.   Often  there is one representing an ISAKMP SA and another
       representing an IPsec SA.

       KLIPS hooks into the routing code in a LINUX  kernel.   Traffic  to  be
       processed  by  an  IPsec  SA  must be directed through KLIPS by routing
       commands.  Furthermore, the processing to be done is specified by ipsec
       eroute(8) commands.  pluto takes the responsibility of managing both of
       these special kinds of routes.

       Each connection may be routed, and must be while it has  an  IPsec  SA.
       The   connection  specifies  the  characteristics  of  the  route:  the
       interface on this machine,  the  ‘‘gateway’’  (the  nexthop),  and  the
       peer’s client subnet.  Two connections may not be simultaneously routed
       if they are for  the  same  peer’s  client  subnet  but  use  different
       interfaces  or  gateways  (pluto’s  logic does not reflect any advanced
       routing capabilities).

       Each eroute is associated with the state object for an IPsec SA because
       it  has the particular characteristics of the SA.  Two eroutes conflict
       if they specify the identical local  and  remote  clients  (unlike  for
       routes, the local clients are taken into account).

       When pluto needs to install a route for a connection, it must make sure
       that no conflicting route is in  use.   If  another  connection  has  a
       conflicting  route,  that route will be taken down, as long as there is
       no IPsec SA instantiating that connection.  If there is such  an  IPsec
       SA, the attempt to install a route will fail.

       There  is  an  exception.   If  pluto, as Responder, needs to install a
       route to a fixed client subnet for a connection, and there is already a
       conflicting  route,  then  the  SAs using the route are deleted to make
       room for the new SAs.  The rationale is  that  the  new  connection  is
       probably  more current.  The need for this usually is a product of Road
       Warrior connections (these are explained later; they cannot be used  to
       initiate).

       When  pluto  needs  to  install  an eroute for an IPsec SA (for a state
       object), first the state object’s connection must be  routed  (if  this
       cannot  be  done,  the  eroute  and  SA  will  not be installed).  If a
       conflicting eroute is already in  place  for  another  connection,  the
       eroute  and  SA  will  not  be  installed  (but  note  that the routing
       exception  mentioned  above  may  have  already   deleted   potentially
       conflicting  SAs).  If another IPsec SA for the same connection already
       has an eroute, all its outgoing  traffic  is  taken  over  by  the  new
       eroute.    The   incoming   traffic  will  still  be  processed.   This
       characteristic is exploited during rekeying.

       All of these routing characteristics are expected change when KLIPS  is
       modified to use the firewall hooks in the LINUX 2.4.x kernel.

   Using Whack
       whack  is  used  to  command a running pluto.  whack uses a UNIX domain
       socket to speak to pluto (by default, /var/pluto.ctl).

       whack has an  intricate  argument  syntax.   This  syntax  allows  many
       different  functions to be specified.  The help form shows the usage or
       version information.  The connection form gives pluto a description  of
       a  potential  connection.  The public key form informs pluto of the RSA
       public key for a potential peer.  The delete form deletes a  connection
       description  and  all  SAs  corresponding to it.  The listen form tells
       pluto to start or stop listening  on  the  public  interfaces  for  IKE
       requests  from peers.  The route form tells pluto to set up routing for
       a connection; the unroute form undoes this.  The  initiate  form  tells
       pluto  to negotiate an SA corresponding to a connection.  The terminate
       form tells pluto to remove  all  SAs  corresponding  to  a  connection,
       including those being negotiated.  The status form displays the pluto’s
       internal state.  The debug form tells pluto to change the selection  of
       debugging output ‘‘on the fly’’.  The shutdown form tells pluto to shut
       down, deleting all SAs.

       Most options are specific to one of the forms, and  will  be  described
       with that form.  There are three options that apply to all forms.

       --ctlbase path
              path.ctl is used as the UNIX domain socket for talking to pluto.
              This option facilitates debugging.

       --optionsfrom filename
              adds the contents of the file to the argument list.

       --label string
              adds the string to all error messages generated by whack.

       The help form of whack is self-explanatory.

       --help display the usage message.

       --version
              display the version of whack.

       The connection form describes a potential connection to  pluto.   pluto
       needs  to  know  what  connections  can and should be negotiated.  When
       pluto is the initiator, it needs to know what to propose.   When  pluto
       is  the  responder,  it  needs  to  know enough to decide whether is is
       willing to set up the proposed connection.

       The description of a potential connection can specify a large number of
       details.   Each connection has a unique name.  This name will appear in
       a updown shell command, so it should not contain punctuation that would
       make the command ill-formed.

       --name connection-name

       The  topology  of  a  connection is symmetric, so to save space here is
       half a picture:

          client_subnet<-->host:ikeport<-->nexthop<---

       A similar trick is used in the flags.  The same flag names are used for
       both ends.  Those before the --to flag describe the left side and those
       afterwards describe the right side.  When pluto  attempts  to  use  the
       connection, it decides whether it is the left side or the right side of
       the connection, based on the IP numbers of its interfaces.

       --id id
              the identity of the end.  Currently, this can be an  IP  address
              (specified  as  dotted quad or as a Fully Qualified Domain Name,
              which will be resolved immediately)  or  as  a  Fully  Qualified
              Domain  Name itself (prefixed by ‘‘@’’ to signify that it should
              not be resolved), or as user@FQDN, or as the magic value  %myid.
              Pluto  only  authenticates the identity, and does not use it for
              addressing, so, for example, an IP address need not be  the  one
              to  which  packets are to be sent.  If the option is absent, the
              identity defaults to the IP address specified by --host.   %myid
              allows  the identity to be separately specified (by the pluto or
              whack  option  --myid  or  by  the  ipsec.conf(5)  config  setup
              parameter  myid).   Otherwise,  pluto  tries to guess what %myid
              should stand for: the IP address  of  %defaultroute,  if  it  is
              supported  by  a  suitable  TXT record in the reverse domain for
              that IP address, or the system’s hostname, if it is supported by
              a suitable TXT record in its forward domain.

       --host ipaddress

       --host %any

       --host %opportunistic
              the  IP address of the end (generally the public interface).  If
              pluto is to act as a responder for  IKE  negotiations  initiated
              from  unknown  IP  addresses (the ‘‘Road Warrior’’ case), the IP
              address should be specified as  %any  (currently,  the  obsolete
              notation  0.0.0.0  is  also  accepted for this).  If pluto is to
              opportunistically initiate the connection, use %opportunistic

       --ikeport portnumber
              the UDP port that IKE listens to on that host.  The  default  is
              500.   (pluto on this machine uses the port specified by its own
              command line argument, so this only affects  where  pluto  sends
              messages.)

       --nexthop ipaddress
              where to route packets for the peer’s client (presumably for the
              peer too, but it  will  not  be  used  for  this).   When  pluto
              installs  an  IPsec  SA, it issues a route command.  It uses the
              nexthop as the gateway.  The default is the  peer’s  IP  address
              (this  can  be  explicitly  written  as  %direct;  the  obsolete
              notation 0.0.0.0 is accepted).   This  option  is  necessary  if
              pluto’s host’s interface used for sending packets to the peer is
              neither point-to-point nor directly connected to the peer.

       --client subnet
              the subnet for which the IPsec traffic will be destined.  If not
              specified,  the  host  will  be  the  client.  The subnet can be
              specified in any of the forms supported  by  ipsec_atosubnet(3).
              The  general  form is address/mask.  The address can be either a
              domain  name  or  four  decimal  numbers   (specifying   octets)
              separated  by  dots.   The most convenient form of the mask is a
              decimal integer, specifying the number of leading  one  bits  in
              the mask.  So, for example, 10.0.0.0/8 would specify the class A
              network ‘‘Net 10’’.

       --dnskeyondemand]
              specifies that when an RSA public key is needed to  authenticate
              this host, and it isn’t already known, fetch it from DNS.

       --updown updown
              specifies  an  external  shell  command to be run whenever pluto
              brings up or down a connection.  The script is used to  build  a
              shell  command,  so  it  may  contain positional parameters, but
              ought not to have punctuation that  would  cause  the  resulting
              command to be ill-formed.  The default is ipsec _updown.

       --to   separates  the  specification  of the left and right ends of the
              connection.

       The potential connection description also specifies characteristics  of
       rekeying and security.

       --psk  Propose and allow preshared secret authentication for IKE peers.
              This authentication requires that each side use the same secret.
              May be combined with --rsasig; at least one must be specified.

       --rsasig
              Propose  and  allow  RSA  signatures  for  authentication of IKE
              peers.  This authentication requires that each side have have  a
              private key of its own and know the public key of its peer.  May
              be combined with --psk; at least one must be specified.

       --encrypt
              All proposed or accepted IPsec SAs will  include  non-null  ESP.
              The actual choices of transforms are wired into pluto.

       --authenticate
              All  proposed IPsec SAs will include AH.  All accepted IPsec SAs
              will include AH or ESP with authentication.  The actual  choices
              of  transforms are wired into pluto.  Note that this has nothing
              to do with IKE authentication.

       --compress
              All proposed IPsec SAs will include IPCOMP (compression).   This
              will  be ignored if KLIPS is not configured with IPCOMP support.

       --tunnel
              the IPsec SA should use tunneling.  Implicit if the  SA  is  for
              clients.  Must only be used with --authenticate or --encrypt.

       --ipv4 The  host addresses will be interpreted as IPv4 addresses.  This
              is the default.  Note that for a connection, all host  addresses
              must  be of the same Address Family (IPv4 and IPv6 use different
              Address Families).

       --ipv6 The host addresses (including nexthop) will  be  interpreted  as
              IPv6  addresses.  Note that for a connection, all host addresses
              must be of the same Address Family (IPv4 and IPv6 use  different
              Address Families).

       --tunnelipv4
              The client addresses will be interpreted as IPv4 addresses.  The
              default is to match what the host will be.  This does not  imply
              --tunnel  so  the  flag  can  be  safely  used when no tunnel is
              actually specified.  Note that  for  a  connection,  all  tunnel
              addresses must be of the same Address Family.

       --tunnelipv6
              The client addresses will be interpreted as IPv6 addresses.  The
              default is to match what the host will be.  This does not  imply
              --tunnel  so  the  flag  can  be  safely  used when no tunnel is
              actually specified.  Note that  for  a  connection,  all  tunnel
              addresses must be of the same Address Family.

       --pfs  There  should  be  Perfect Forward Secrecy - new keying material
              will be generated for each IPsec SA rather  than  being  derived
              from  the ISAKMP SA keying material.  Since the group to be used
              cannot be negotiated (a dubious feature of the standard),  pluto
              will  propose  the  same group that was used during Phase 1.  We
              don’t implement a stronger form of PFS which would require  that
              the ISAKMP SA be deleted after the IPSEC SA is negotiated.

       --disablearrivalcheck
              If  the  connection  is a tunnel, allow packets arriving through
              the tunnel to have any source and destination addresses.

       If none of the --encrypt, --authenticate, --compress, or --pfs flags is
       given, the initiating the connection will only build an ISAKMP SA.  For
       such a connection, client subnets have  no  meaning  and  must  not  be
       specified.

       More  work  is needed to allow for flexible policies.  Currently policy
       is hardwired in the source file spdb.c.  The ISAKMP SAs may use  Oakley
       groups  MODP1024  and  MODP1536;  3DES  encryption;  SHA1-96 and MD5-96
       authentication.  The IPsec SAs may use 3DES and MD5-96 or  SHA1-96  for
       ESP,  or  just  MD5-96 or SHA1-96 for AH.  IPCOMP Compression is always
       Deflate.

       --ikelifetime seconds
              how long pluto will propose that an  ISAKMP  SA  be  allowed  to
              live.   The  default  is  10800 (three hours) and the maximum is
              86400 (one day).  This option will not affect what is  accepted.
              pluto will reject proposals that exceed the maximum.

       --ipseclifetime seconds
              how long pluto will propose that an IPsec SA be allowed to live.
              The default is 3600 (one hour) and the  maximum  is  86400  (one
              day).  This option will not affect what is accepted.  pluto will
              reject proposals that exceed the maximum.

       --rekeymargin seconds
              how long before an SA’s expiration should pluto try to negotiate
              a  replacement  SA.   This  will  only  happen  if pluto was the
              initiator.  The default is 540 (nine minutes).

       --rekeyfuzz percentage
              maximum  size  of  random  component  to  add  to   rekeymargin,
              expressed  as  a percentage of rekeymargin.  pluto will select a
              delay uniformly distributed within this range.  By default,  the
              percentage  will  be  100.   If  greater determinism is desired,
              specify 0.  It may be appropriate for the percentage to be  much
              larger than 100.

       --keyingtries count
              how  many  times pluto should try to negotiate an SA, either for
              the first time or for rekeying.  A value of 0 is interpreted  as
              a very large number: never give up.  The default is three.

       --dontrekey
              A  misnomer.   Only  rekey a connection if we were the Initiator
              and there was recent traffic on the existing  connection.   This
              applies  to  Phase  1  and  Phase 2.  This is currently the only
              automatic way for a connection to terminate.  It may  be  useful
              with Road Warrior or Opportunistic connections.
              Since   SA   lifetime  negotiation  is  take-it-or-leave  it,  a
              Responder normally uses the shorter of  the  negotiated  or  the
              configured lifetime.  This only works because if the lifetime is
              shorter than negotiated, the Responder will  rekey  in  time  so
              that  everything  works.  This interacts badly with --dontrekey.
              In this case, the Responder will end up rekeying  to  rectify  a
              shortfall  in  an  IPsec  SA  lifetime;  for  an  ISAKMP SA, the
              Responder will accept the negotiated lifetime.

       --delete
              when used  in  the  connection  form,  it  causes  any  previous
              connection  with  this  name  to  be  deleted before this one is
              added.  Unlike a normal delete, no  diagnostic  is  produced  if
              there  was  no  previous  connection  to delete.  Any routing in
              place for the connection is undone.

       The delete form deletes a named  connection  description  and  any  SAs
       established  or  negotiations  initiated  using  this  connection.  Any
       routing in place for the connection is undone.

       --delete

       --name connection-name

       The deletestate form deletes the state object with the specified serial
       number.    This   is  useful  for  selectively  deleting  instances  of
       connections.

       --deletestate state-number

       The route form of the whack command tells pluto to set up routing for a
       connection.  Although like a traditional route, it uses an ipsec device
       as a virtual interface.  Once routing is set up,  no  packets  will  be
       sent ‘‘in the clear’’ to the peer’s client specified in the connection.
       A TRAP shunt eroute will be installed; if outbound traffic  is  caught,
       Pluto  will  initiate  the  connection.  An explicit whack route is not
       always needed: if it hasn’t  been  done  when  an  IPsec  SA  is  being
       installed, one will be automatically attempted.

       When a routing is attempted for a connection, there must not already be
       a routing for a different connection with the same subnet but different
       interface  or destination, or if there is, it must not be being used by
       an IPsec SA.  Otherwise the attempt will fail.

       --route

       --name connection-name

       The unroute form of the whack command tells pluto to  undo  a  routing.
       pluto  will  refuse if an IPsec SA is using the connection.  If another
       connection is sharing the same routing,  it  will  be  left  in  place.
       Without   a  routing,  packets  will  be  sent  without  encryption  or
       authentication.

       --unroute

       --name connection-name

       The initiate form tells pluto to initiate a  negotiation  with  another
       pluto  (or  other  IKE  daemon)  according  to  the  named  connection.
       Initiation requires a route that --route would provide; if none  is  in
       place at the time an IPsec SA is being installed, pluto attempts to set
       one up.

       --initiate

       --name connection-name

       --asynchronous

       The initiate form of the whack  command  will  relay  back  from  pluto
       status information via the UNIX domain socket (unless --asynchronous is
       specified).  The status information is meant to look a  bit  like  that
       from  FTP.   Currently  whack  simply  copies this to stderr.  When the
       request is finished (eg. the SAs are established or  pluto  gives  up),
       pluto closes the channel, causing whack to terminate.

       The opportunistic initiate form is mainly used for debugging.

       --tunnelipv4

       --tunnelipv6

       --oppohere ip-address

       --oppothere ip-address

       This  will  cause  pluto  to  attempt  to  opportunistically initiate a
       connection from here to the there, even if a previous attempt had  been
       made.  The whack log will show the progress of this attempt.

       The terminate form tells pluto to delete any SAs that use the specified
       connection and to stop  any  negotiations  in  process.   It  does  not
       prevent  new  negotiations  from  starting  (the  delete  form has this
       effect).

       --terminate

       --name connection-name

       The public key for informs pluto of the RSA public key for a  potential
       peer.   Private  keys  must  be  kept  secret,  so  they  are  kept  in
       ipsec.secrets(5).

       --keyid id
              specififies the identity of the peer  for  which  a  public  key
              should  be  used.   Its form is identical to the identity in the
              connection.  If no public key is specified,  pluto  attempts  to
              find  KEY  records  from  DNS  for the id (if a FQDN) or through
              reverse lookup (if an IP  address).   Note  that  there  several
              interesting ways in which this is not secure.

       --addkey
              specifies that the new key is added to the collection; otherwise
              the new key replaces any old ones.

       --pubkeyrsa key
              specifies the value of the RSA public key.  It is a sequence  of
              bytes  as  described  in RFC 2537 ‘‘RSA/MD5 KEYs and SIGs in the
              Domain Name System (DNS)’’.  It is denoted in a way suitable for
              ipsec_ttodata(3).   For  example,  a base 64 numeral starts with
              0s.

       The listen form tells pluto to start listening for IKE requests on  its
       public  interfaces.  To avoid race conditions, it is normal to load the
       appropriate connections into pluto before allowing it  to  listen.   If
       pluto  isn’t listening, it is pointless to initiate negotiations, so it
       will refuse requests to do so.  Whenever the listen form is used, pluto
       looks  for  public  interfaces  and will notice when new ones have been
       added and when old ones have been removed.  This is  also  the  trigger
       for  pluto  to  read the ipsec.secrets file.  So listen may useful more
       than once.

       --listen
              start listening for IKE traffic on public interfaces.

       --unlisten
              stop listening for IKE traffic on public interfaces.

       The status form will display information about the  internal  state  of
       pluto:  information  about  each potential connection, about each state
       object, and  about  each  shunt  that  pluto  is  managing  without  an
       associated connection.

       --status

       The  shutdown  form is the proper way to shut down pluto.  It will tear
       down the SAs on this machine that pluto has negotiated.   It  does  not
       inform its peers, so the SAs on their machines remain.

       --shutdown

   Examples
       It  would  be normal to start pluto in one of the system initialization
       scripts.  It needs to be run by the superuser.  Generally, no arguments
       are needed.  To run in manually, the superuser can simply type

          ipsec pluto

       The  command  will immediately return, but a pluto process will be left
       running, waiting for requests from whack or a peer.

       Using whack, several potential connections would be described:

          ipsec whack --name silly --host 127.0.0.1 --to --host 127.0.0.2
              --ikelifetime 900 --ipseclifetime 800 --keyingtries 3

       Since  this  silly connection description specifies neither encryption,
       authentication, nor tunneling, it could only be used  to  establish  an
       ISAKMP SA.

          ipsec whack --name secret --host 10.0.0.1 --client 10.0.1.0/24 --to
              --host 10.0.0.2 --client 10.0.2.0/24 --encrypt

       This is something that must be done on both sides.  If the  other  side
       is  pluto,  the  same  whack  command  could be used on it (the command
       syntax is designed to not distinguish which end is ours).

       Now that the connections  are  specified,  pluto  is  ready  to  handle
       requests  and  replies  via  the public interfaces.  We must tell it to
       discover those interfaces and start accepting messages from peers:

          ipsec whack --listen

       If we don’t immediately wish to bring up a  secure  connection  between
       the  two  clients,  we  might  wish  to  prevent insecure traffic.  The
       routing form asks pluto to cause the packets sent from  our  client  to
       the  peer’s  client to be routed through the ipsec0 device; if there is
       no SA, they will be discarded:

          ipsec whack --route secret

       Finally, we are ready to get pluto to initiate negotiation for an IPsec
       SA (and implicitly, an ISAKMP SA):

          ipsec whack --initiate --name secret

       A small log of interesting events will appear on standard output (other
       logging is sent to syslog).

       whack can also be used to terminate pluto cleanly, tearing down all SAs
       that it has negotiated.

          ipsec whack --shutdown

       Notification  of  any  IPSEC SA deletion, but not ISAKMP SA deletion is
       sent to the peer.  Unfortunately, such Notification  is  not  reliable.
       Furthermore, pluto itself ignores Notifications.

   The updown command
       Whenever  pluto  brings  a connection up or down, it invokes the updown
       command.  This command is specified using the  --updown  option.   This
       allows for customized control over routing and firewall manipulation.

       The  updown  is  invoked  for five different operations.  Each of these
       operations can be for our client subnet or for our host itself.

       prepare-host or prepare-client
              is  run  before  bringing  up  a  new  connection  if  no  other
              connection  with  the  same  clients  is up.  Generally, this is
              useful for deleting a route that might have been set  up  before
              pluto was run or perhaps by some agent not known to pluto.

       route-host or route-client
              is  run  when  bringing  up  a  connection for a new peer client
              subnet (even if prepare-host or prepare-client  was  run).   The
              command  should install a suitable route.  Routing decisions are
              based only on the destination (peer’s  client)  subnet  address,
              unlike eroutes which discriminate based on source too.

       unroute-host or unroute-client
              is  run  when bringing down the last connection for a particular
              peer client subnet.  It  should  undo  what  the  route-host  or
              route-client did.

       up-host or up-client
              is  run  when  bringing up a tunnel eroute with a pair of client
              subnets that does  not  already  have  a  tunnel  eroute.   This
              command  should  install  firewall  rules as appropriate.  It is
              generally a good idea to  allow  IKE  messages  (UDP  port  500)
              travel between the hosts.

       down-host or down-client
              is  run  when  bringing  down  the  eroute  for a pair of client
              subnets.   This  command  should  delete   firewall   rules   as
              appropriate.   Note that there may remain some inbound IPsec SAs
              with these client subnets.

       The script is passed a large number of environment variables to specify
       what needs to be done.

       PLUTO_VERSION
              indicates  what  version  of this interface is being used.  This
              document describes version 1.1.   This  is  upwardly  compatible
              with version 1.0.

       PLUTO_VERB
              specifies  the  name  of the operation to be performed (prepare-
              host,r prepare-client, up-host, up-client, down-host,  or  down-
              client).  If the address family for security gateway to security
              gateway communications is IPv6, then a suffix of -v6 is added to
              the verb.

       PLUTO_CONNECTION
              is the name of the connection for which we are routing.

       PLUTO_NEXT_HOP
              is  the  next  hop  to  which packets bound for the peer must be
              sent.

       PLUTO_INTERFACE
              is the name of the ipsec interface to be used.

       PLUTO_ME
              is the IP address of our host.

       PLUTO_MY_CLIENT
              is the IP address / count of our client subnet.  If  the  client
              is  just  the host, this will be the host’s own IP address / max
              (where max is 32 for IPv4 and 128 for IPv6).

       PLUTO_MY_CLIENT_NET
              is the IP address of our client net.  If the client is just  the
              host, this will be the host’s own IP address.

       PLUTO_MY_CLIENT_MASK
              is the mask for our client net.  If the client is just the host,
              this will be 255.255.255.255.

       PLUTO_PEER
              is the IP address of our peer.

       PLUTO_PEER_CLIENT
              is the IP address / count of the peer’s client subnet.   If  the
              client  is just the peer, this will be the peer’s own IP address
              / max (where max is 32 for IPv4 and 128 for IPv6).

       PLUTO_PEER_CLIENT_NET
              is the IP address of the peer’s client net.  If  the  client  is
              just the peer, this will be the peer’s own IP address.

       PLUTO_PEER_CLIENT_MASK
              is  the  mask  for the peer’s client net.  If the client is just
              the peer, this will be 255.255.255.255.

       All output sent by the script to  stderr  or  stdout  is  logged.   The
       script should return an exit status of 0 if and only if it succeeds.

       Pluto  waits  for  the  script  to  finish  and  will  not do any other
       processing while it is waiting.  The script may assume that pluto  will
       not  change  anything  while  the script runs.  The script should avoid
       doing anything that takes much time and it should not issue any command
       that requires processing by pluto.  Either of these activities could be
       performed by a background subprocess of the script.

   Rekeying
       When an SA that was initiated by pluto has only a bit of lifetime left,
       pluto  will  initiate the creation of a new SA.  This applies to ISAKMP
       and IPsec SAs.  The rekeying will be initiated when the SA’s  remaining
       lifetime is less than the rekeymargin plus a random percentage, between
       0 and rekeyfuzz, of the rekeymargin.

       Similarly, when an SA that was initiated by the peer has only a bit  of
       lifetime   left,   pluto  will  try  to  initiate  the  creation  of  a
       replacement.  To give preference to the initiator, this  rekeying  will
       only  be  initiated  when  the  SA’s  remaining  lifetime  is  half  of
       rekeymargin.  If rekeying is done by the responder, the roles  will  be
       reversed:  the  responder  for the old SA will be the initiator for the
       replacement.  The former initiator might  also  initiate  rekeying,  so
       there may be redundant SAs created.  To avoid these complications, make
       sure that rekeymargin is generous.

       One risk of having the former responder initiate is that  perhaps  none
       of  its  proposals is acceptable to the former initiator (they have not
       been used in a successful negotiation).  To reduce the chances of  this
       happening,  and  to  prevent  loss of security, the policy settings are
       taken from the old SA (this is the case even if the former initiator is
       initiating).  These may be stricter than those of the connection.

       pluto  will  not  rekey  an SA if that SA is not the most recent of its
       type (IPsec or ISAKMP)  for  its  potential  connection.   This  avoids
       creating redundant SAs.

       The  random  component  in the rekeying time (rekeyfuzz) is intended to
       make certain pathological patterns of rekeying unstable.  If both sides
       decide  to  rekey  at the same time, twice as many SAs as necessary are
       created.  This could become a stable pattern without the randomness.

       Another more important case occurs when a security gateway has SAs with
       many  other security gateways.  Each of these connections might need to
       be rekeyed at the same time.  This would cause a high peek  requirement
       for   resources  (network  bandwidth,  CPU  time,  entropy  for  random
       numbers).  The rekeyfuzz can be used to stagger the rekeying times.

       Once a new set of SAs  has  been  negotiated,  pluto  will  never  send
       traffic  on  a  superseded  one.  Traffic will be accepted on an old SA
       until it expires.

   Selecting a Connection When Responding: Road Warrior Support
       When pluto receives an initial Main Mode message, it  needs  to  decide
       which  connection  this  message  is for.  It picks based solely on the
       source and destination IP addresses of the  message.   There  might  be
       several  connections  with  suitable IP addresses, in which case one of
       them is arbitrarily chosen.  (The ISAKMP SA proposal contained  in  the
       message could be taken into account, but it is not.)

       The ISAKMP SA is negotiated before the parties pass further identifying
       information,  so  all  ISAKMP  SA  characteristics  specified  in   the
       connection description should be the same for every connection with the
       same two host IP addresses.  At the  moment,  the  only  characteristic
       that might differ is authentication method.

       Up  to  this  point, all configuring has presumed that the IP addresses
       are known to all parties ahead of time.  This will not work when either
       end is mobile (or assigned a dynamic IP address for other reasons).  We
       call this situation ‘‘Road Warrior’’.  It is fairly tricky and has some
       important  limitations, most of which are features of the IKE protocol.

       Only the initiator may be mobile: the initiator may have an  IP  number
       unknown  to the responder.  When the responder doesn’t recognize the IP
       address on the first Main Mode packet, it looks for a  connection  with
       itself  as  one  end  and %any as the other.  If it cannot find one, it
       refuses to negotiate.  If it does find  one,  it  creates  a  temporary
       connection  that  is  a  duplicate except with the %any replaced by the
       source IP address from the packet; if there was no  identity  specified
       for the peer, the new IP address will be used.

       When  pluto  is  using  one of these temporary connections and needs to
       find the preshared secret or RSA private key in ipsec.secrets, and  and
       the  connection specified no identity for the peer, %any is used as its
       identity.  After all, the real IP address was apparently unknown to the
       configuration, so it is unreasonable to require that it be used in this
       table.

       Part way into the Phase 1 (Main Mode) negotiation using  one  of  these
       temporary  connection  descriptions,  pluto will be receive an Identity
       Payload.   At  this  point,  pluto  checks  for  a   more   appropriate
       connection,  one with an identity for the peer that matches the payload
       but which would use the same keys so-far used for  authentication.   If
       it  finds  one,  it  will  switch to using this better connection (or a
       temporary derived from this, if it has %any for the peer’s IP address).
       It  may  even  turn out that no connection matches the newly discovered
       identity, including the current connection;  if  so,  pluto  terminates
       negotiation.

       Unfortunately,  if  preshared  secret authentication is being used, the
       Identity Payload is encrypted using this secret, so the secret must  be
       selected  by  the  responder without knowing this payload.  This limits
       there to being at most  one  preshared  secret  for  all  Road  Warrior
       systems  connecting  to a host.  RSA Signature authentications does not
       require that the responder know how to select  the  initiator’s  public
       key  until after the initiator’s Identity Payload is decoded (using the
       responder’s private key, so that must be preselected).

       When pluto is responding to a Quick Mode negotiation via one  of  these
       temporary  connection  descriptions,  it may well find that the subnets
       specified  by  the  initiator  don’t  match  those  in  the   temporary
       connection  description.   If  so,  it  will look for a connection with
       matching subnets, its own host address, a  peer  address  of  %any  and
       matching  identities.   If  it finds one, a new temporary connection is
       derived from this one and used for the Quick Mode negotiation of  IPsec
       SAs.  If it does not find one, pluto terminates negotiation.

       Be  sure  to specify an appropriate nexthop for the responder to send a
       message to  the  initiator:  pluto  has  no  way  of  guessing  it  (if
       forwarding  isn’t  required, use an explicit %direct as the nexthop and
       the IP address of  the  initiator  will  be  filled  in;  the  obsolete
       notation 0.0.0.0 is still accepted).

       pluto  has  no  special  provision for the initiator side.  The current
       (possibly dynamic) IP address and nexthop  must  be  used  in  defining
       connections.    These   must  be  properly  configured  each  time  the
       initiator’s IP address changes.  pluto has  no  mechanism  to  do  this
       automatically.

       Although  we  call  this Road Warrior Support, it could also be used to
       support  encrypted  connections   with   anonymous   initiators.    The
       responder’s organization could announce the preshared secret that would
       be used with unrecognized initiators and let anyone connect.  Of course
       the initiator’s identity would not be authenticated.

       If  any  Road Warrior connections are supported, pluto cannot reject an
       exchange initiated by an unknown host until it has determined that  the
       secret  is not shared or the signature is invalid.  This must await the
       third Main Mode  message  from  the  initiator.   If  no  Road  Warrior
       connection is supported, the first message from an unknown source would
       be  rejected.   This   has   implications   for   ease   of   debugging
       configurations and for denial of service attacks.

       Although  a  Road  Warrior  connection  must be initiated by the mobile
       side, the other side can and will rekey using the temporary  connection
       it  has  created.  If the Road Warrior wishes to be able to disconnect,
       it is probably wise to set --keyingtries to 1 in the connection on  the
       non-mobile   side  to  prevent  it  trying  to  rekey  the  connection.
       Unfortunately,  there  is  no  mechanism  to  unroute  the   connection
       automatically.

   Debugging
       pluto  accepts several optional arguments, useful mostly for debugging.
       Except for --interface, each should appear at most once.

       --interface interfacename
              specifies that the named real public network interface should be
              considered.   The interface name specified should not be ipsecN.
              If the option doesn’t appear, all interfaces are considered.  To
              specify  several  interfaces, use the option once for each.  One
              use of this option is to specify which interface should be  used
              when two or more share the same IP address.

       --ikeport port-number
              changes  the UDP port that pluto will use (default, specified by
              IANA: 500)

       --ctlbase path
              basename for control files.   path.ctl  is  the  socket  through
              which  whack  communicates with pluto.  path.pid is the lockfile
              to  prevent  multiple   pluto   instances.    The   default   is
              /var/run/pluto).

       --secretsfile file
              specifies   the   file   for  authentication  secrets  (default:
              /etc/ipsec.secrets).  This name is subject to ‘‘globbing’’ as in
              sh(1), so every file with a matching name is processed.  Quoting
              is  generally  needed  to  prevent  the  shell  from  doing  the
              globbing.

       --adns pathname

       --lwdnsq pathname
              specifies  where to find pluto’s helper program for asynchronous
              DNS lookup.  pluto can  be  built  to  use  one  of  two  helper
              programs:  _pluto_adns  or lwdnsq.  You must use the program for
              which it was built.  By default, pluto will look for the program
              in  $IPSEC_DIR  (if  that  environment  variable is defined) or,
              failing that, in the same directory as pluto.

       --nofork
              disable ‘‘daemon fork’’ (default  is  to  fork).   In  addition,
              after  the  lock  file and control socket are created, print the
              line ‘‘Pluto initialized’’ to standard out.

       --noklips
              don’t actually implement negotiated IPsec SAs

       --uniqueids
              if this option has been selected, whenever a new  ISAKMP  SA  is
              established,  any  connection  with  the  same  Peer  ID  but  a
              different Peer IP address is unoriented (causing all its SAs  to
              be deleted).  This helps clean up dangling SAs when a connection
              is lost and then regained at another IP address.

       --stderrlog
              log goes to standard out {default is to use syslogd(8))

       For example

       pluto --secretsfile ipsec.secrets  --ctlbase pluto.base  --ikeport 8500
       --nofork --noklips --stderrlog

       lets one test pluto without using the superuser account.

       pluto  is  willing  to  produce  a  prodigious  amount   of   debugging
       information.   To  do  so, it must be compiled with -DDEBUG.  There are
       several classes of debugging output,  and  pluto  may  be  directed  to
       produce  a  selection  of  them.   All  lines  of  debugging output are
       prefixed with ‘‘| ’’ to distinguish them from error messages.

       When pluto is invoked, it may  be  given  arguments  to  specify  which
       classes to output.  The current options are:

       --debug-raw
              show the raw bytes of messages

       --debug-crypt
              show the encryption and decryption of messages

       --debug-parsing
              show the structure of input messages

       --debug-emitting
              show the structure of output messages

       --debug-control
              show pluto’s decision making

       --debug-lifecycle
              [this option is temporary] log more detail of lifecycle of SAs

       --debug-klips
              show pluto’s interaction with KLIPS

       --debug-dns
              show pluto’s interaction with DNS for KEY and TXT records

       --debug-oppo
              show  why  pluto  didn’t  find  a  suitable  DNS  TXT  record to
              authorize opportunistic initiation

       --debug-all
              all of the above

       --debug-private
              allow debugging output with private keys.

       --debug-none
              none of the above

       The debug form of the whack command will  change  the  selection  in  a
       running  pluto.  If a connection name is specified, the flags are added
       whenever pluto has identified that it is dealing with that  connection.
       Unfortunately,  this  is  often  part  way  into  the  operation  being
       observed.

       For example, to start a pluto with a display of the structure of  input
       and output:

              pluto --debug-emitting --debug-parsing

       To later change this pluto to only display raw bytes:

              whack --debug-raw

       For testing, SSH’s IKE test page is quite useful:

              http://isakmp-test.ssh.fi/

       Hint:  ISAKMP  SAs are often kept alive by IKEs even after the IPsec SA
       is established.   This  allows  future  IPsec  SA’s  to  be  negotiated
       directly.   If  one  of the IKEs is restarted, the other may try to use
       the ISAKMP SA but the new IKE won’t know about it.  This  can  lead  to
       much  confusion.   pluto  is  not yet smart enough to get out of such a
       mess.

   Plutos Behaviour When Things Go Wrong
       When pluto doesn’t understand or accept a message, it just ignores  the
       message.   It  is  not  yet capable of communicating the problem to the
       other  IKE  daemon  (in  the  future  it  might  use  Notifications  to
       accomplish this in many cases).  It does log a diagnostic.

       When pluto gets no response from a message, it resends the same message
       (a message will be sent at most three times).  This is appropriate: UDP
       is unreliable.

       When  pluto  gets  a  message  that it has already seen, there are many
       cases when it notices and discards it.  This  too  is  appropriate  for
       UDP.

       Combine  these  three  rules,  and  you  can  explain  many  apparently
       mysterious behaviours.  In a pluto  log,  retrying  isn’t  usually  the
       interesting  event.   The critical thing is either earlier (pluto got a
       message which it didn’t like and so ignored, so it was  still  awaiting
       an  acceptable message and got impatient) or on the other system (pluto
       didn’t send a reply because it wasn’t happy with the previous message).

   Notes
       If   pluto   is   compiled  without  -DKLIPS,  it  negotiates  Security
       Associations but never ask the kernel to put them in  place  and  never
       makes  routing  changes.   This  allows  pluto  to be tested on systems
       without KLIPS, but makes it rather useless.

       Each IPsec SA is assigned an SPI, a 32-bit number used to refer to  the
       SA.   The  IKE  protocol lets the destination of the SA choose the SPI.
       The range 0 to 0xFF is reserved for IANA.  Pluto also  avoids  choosing
       an  SPI in the range 0x100 to 0xFFF, leaving these SPIs free for manual
       keying.  Remember that the peer, if not pluto, may well chose  SPIs  in
       this range.

   Policies
       This catalogue of policies may be of use when trying to configure Pluto
       and another IKE implementation to interoperate.

       In Phase 1, only  Main  Mode  is  supported.   We  are  not  sure  that
       Aggressive Mode is secure.  For one thing, it does not support identity
       protection.  It may allow more severe Denial Of Service attacks.

       No Informational Exchanges are supported.  These are optional and since
       their  delivery  is  not assured, they must not matter.  It is the case
       that some IKE implementations won’t interoperate without  Informational
       Exchanges, but we feel they are broken.

       No  Informational  Payloads  are  supported.   These  are optional, but
       useful.  It is of concern that these payloads are not authenticated  in
       Phase 1, nor in those Phase 2 messages authenticated with HASH(3).

       · Diffie  Hellman  Groups  MODP  1024  and  MODP  1536  (2  and  5) are
         supported.  Group MODP768 (1) is not  supported  because  it  is  too
         weak.

       · Host  authetication  can  be  done  by  RSA  Signatures or Pre-Shared
         Secrets.

       · 3DES  CBC  (Cypher  Block  Chaining  mode)  is  the  only  encryption
         supported, both for ISAKMP SAs and IPSEC SAs.

       · MD5  and SHA1 hashing are supported for packet authentication in both
         kinds of SAs.

       · The ESP, AH, or AH plus ESP are supported.  If, and only if,  AH  and
         ESP  are  combined,  the  ESP  need  not  have its own authentication
         component.   The  selection  is  controlled  by  the  --encrypt   and
         --authenticate flags.

       · Each  of  these  may be combined with IPCOMP Deflate compression, but
         only if the potential connection specifies compression  and  only  if
         KLIPS is configured with IPCOMP support.

       · The  IPSEC  SAs  may  be tunnel or transport mode, where appropriate.
         The --tunnel flag controls this when pluto is initiating.

       · When responding to an ISAKMP  SA  proposal,  the  maximum  acceptable
         lifetime  is  eight  hours.   The  default  is one hour.  There is no
         minimum.   The  --ikelifetime  flag  controls  this  when  pluto   is
         initiating.

       · When  responding  to  an  IPSEC  SA  proposal, the maximum acceptable
         lifetime is one day.  The  default  is  eight  hours.   There  is  no
         minimum.   The  --ipseclifetime  flag  controls  this  when  pluto is
         initiating.

       · PFS is acceptable, and  will  be  proposed  if  the  --pfs  flag  was
         specified.   The DH group proposed will be the same as negotiated for
         Phase 1.

SIGNALS

       Pluto  responds  to  SIGHUP  by  issuing  a  suggestion  that   ‘‘whack
       --listen’’ might have been intended.

       Pluto exits when it recieves SIGTERM.

EXIT STATUS

       pluto normally forks a daemon process, so the exit status is normally a
       very preliminary result.

       0      means that all is OK so far.

       1      means that something was wrong.

       10     means that the lock file already exists.

       If whack detects a problem, it will return an exit status of 1.  If  it
       received  progress  messages from pluto, it returns as status the value
       of the numeric prefix from the last such message that was not a message
       sent  to  syslog or a comment (but the prefix for success is treated as
       0).  Otherwise, the exit status is 0.

FILES

       /var/run/pluto.pid
       /var/run/pluto.ctl
       /etc/ipsec.secrets
       $IPSEC_LIBDIR/_pluto_adns
       $IPSEC_EXECDIR/lwdnsq
       /dev/urandom

ENVIRONMENT

       IPSEC_LIBDIR
       IPSEC_EXECDIR
       IPSECmyid

SEE ALSO

       The rest of the FreeS/WAN distribution, in particular ipsec(8).

       ipsec_auto(8) is designed to make using pluto more pleasant.  Use it!

       ipsec.secrets(5) describes the format of the secrets file.

       ipsec_atoaddr(3), part of the  FreeS/WAN  distribution,  describes  the
       forms  that  IP  addresses  may  take.  ipsec_atosubnet(3), part of the
       FreeS/WAN distribution, describes the forms that subnet specifications.

       For  more  information  on  IPsec,  the  mailing list, and the relevant
       documents, see:

              http://www.ietf.cnri.reston.va.us/html.charters/ipsec-
              charter.html

       At the time of writing, the most relevant IETF RFCs are:

              RFC2409 The Internet Key Exchange (IKE)

              RFC2408   Internet   Security  Association  and  Key  Management
              Protocol (ISAKMP)

              RFC2407 The Internet IP Security Domain  of  Interpretation  for
              ISAKMP

       The  FreeS/WAN  web site <htp://www.freeswan.org> and the mailing lists
       described there.

HISTORY

       This code is released under the GPL terms.  See the  accompanying  file
       COPYING-2.0  for  more details.  The GPL does NOT apply to those pieces
       of code written by others which  are  included  in  this  distribution,
       except as noted by the individual authors.

       This   software  was  originally  written  for  the  FreeS/WAN  project
       <http://www.freeswan.org>      by      Angelos       D.       Keromytis
       (angelos@dsl.cis.upenn.edu),  in  May/June  1997,  in  Athens,  Greece.
       Thanks go to John Ioannidis for his help.

       It is currently (2000)  being  developed  and  maintained  by  D.  Hugh
       Redelmeier (hugh@mimosa.com), in Canada.  The regulations of Greece and
       Canada allow us to make the code freely redistributable.

       Kai  Martius  (admin@imib.med.tu-dresden.de)  contributed  the  initial
       version of the code supporting PFS.

       Richard   Guy   Briggs   <rgb@conscoop.ottawa.on.ca>  and  Peter  Onion
       <ponion@srd.bt.co.uk> added the PFKEY2 support.

       We gratefully acknowledge that we use  parts  of  Eric  Young’s  libdes
       package; see ../libdes/COPYRIGHT.

BUGS

       pluto  is  a work-in-progress.  It currently has many limitations.  For
       example, it ignores notification messages  that  it  receives,  and  it
       generates only Delete Notifications and those only for IPSEC SAs.

       pluto  does  not  support  the  Commit  Flag.  The Commit Flag is a bad
       feature of the IKE protocol.  It isn’t protected --  neither  encrypted
       nor  authenticated.   A  man in the middle could turn it on, leading to
       DoS.   We  just  ignore  it,  with  a  warning.   This  should  let  us
       interoperate with implementations that insist on it, with minor damage.

       pluto does not check that the SA returned by the Responder is  actually
       one  that was proposed.  It only checks that the SA is acceptable.  The
       difference is not large, but can show  up  in  attributes  such  as  SA
       lifetime.

       There  is  no good way for a connection to be automatically terminated.
       This is a problem for Road Warrior and Opportunistic connections.   The
       --dontrekey  option  does prevent the SAs from being rekeyed on expiry.
       Additonally, if a Road Warrior connection has a client  subnet  with  a
       fixed  IP  address, a negotiation with that subnet will cause any other
       connection instantiations  with  that  same  subnet  to  be  unoriented
       (deleted, in effect).  See also the --uniqueids option for an extension
       of this.

       When pluto sends a message  to  a  peer  that  has  disappeared,  pluto
       receives  incomplete  information  from  the  kernel,  so  it  logs the
       unsatisfactory message ‘‘some IKE message we  sent  has  been  rejected
       with ECONNREFUSED (kernel supplied no details)’’.  John Denker suggests
       that this command is useful for  tracking  down  the  source  of  these
       problems:
            tcpdump -i eth0 icmp[0] != 8 and icmp[0] != 0
       Substitute your public interface for eth0 if it is different.

       The  word ‘‘authenticate’’ is used for two different features.  We must
       authenticate each IKE peer to the other.  This is an important task  of
       Phase  1.  Each packet must be authenticated, both in IKE and in IPsec,
       and the method for IPsec is negotiated as an AH SA or part  of  an  ESP
       SA.   Unfortunately,  the  protocol has no mechanism for authenticating
       the Phase 2 identities.

       Bugs should be reported to the <users@lists.freeswan.org> mailing list.
       Caution:  we  cannot  accept  actual code from US residents, or even US
       citizens living outside the US,  because  that  would  bring  FreeS/WAN
       under  US export law.  Some other countries cause similar problems.  In
       general, we would prefer that you send detailed problem reports  rather
       than  code:   we want FreeS/WAN to be unquestionably freely exportable,
       which means being very careful about where the code comes from, and for
       a   small  bug  fix,  that  is  often  more  time-consuming  than  just
       reinventing the fix ourselves.

                                 28 March 1999                  IPSEC_PLUTO(8)