Provided by: keyutils_1.2-7_i386 bug

NAME

       keyctl - Key management facility control

SYNOPSIS

       keyctl show
       keyctl add <type> <desc> <data> <keyring>
       keyctl padd <type> <desc> <keyring>
       keyctl request <type> <desc> [<dest_keyring>]
       keyctl request2 <type> <desc> <info> [<dest_keyring>]
       keyctl prequest2 <type> <desc> [<dest_keyring>]
       keyctl update <key> <data>
       keyctl pupdate <key>
       keyctl newring <name> <keyring>
       keyctl revoke <key>
       keyctl clear <keyring>
       keyctl link <key> <keyring>
       keyctl unlink <key> <keyring>
       keyctl search <keyring> <type> <desc> [<dest_keyring>]
       keyctl read <key>
       keyctl pipe <key>
       keyctl print <key>
       keyctl list <keyring>
       keyctl rlist <keyring>
       keyctl describe <keyring>
       keyctl rdescribe <keyring> [sep]
       keyctl chown <key> <uid>
       keyctl chgrp <key> <gid>
       keyctl setperm <key> <mask>
       keyctl session
       keyctl session - [<prog> <arg1> <arg2> ...]
       keyctl session <name> [<prog> <arg1> <arg2> ...]
       keyctl instantiate <key> <data> <keyring>
       keyctl pinstantiate <key> <keyring>
       keyctl negate <key> <timeout> <keyring>
       keyctl timeout <key> <timeout>

DESCRIPTION

       This  program is used to control the key management facility in various
       ways using a variety of subcommands.

KEY IDENTIFIERS

       The key identifiers passed to or returned from keyctl are, in  general,
       positive integers. There are, however, some special values with special
       meanings that can be passed as arguments:

       (*) No key: 0

       (*) Thread keyring: @t or -1

       Each thread may have its own keyring. This is  searched  first,  before
       all  others. The thread keyring is replaced by (v)fork, exec and clone.

       (*) Process keyring: @p or -2

       Each process (thread group) may have its own keyring.  This  is  shared
       between  all  members  of a group and will be searched after the thread
       keyring. The process keyring is replaced by (v)fork and exec.

       (*) Session keyring: @s or -3

       Each process subscribes to a session keyring that is  inherited  across
       (v)fork,  exec  and  clone. This is searched after the process keyring.
       Session keyrings can be named and an extant keyring can  be  joined  in
       place of a process’s current session keyring.

       (*) User specific keyring: @u or -4

       This  keyring is shared between all the processes owned by a particular
       user. It isn’t searched directly, but is normally linked  to  from  the
       session keyring.

       (*) User default session keyring: @us or -5

       This  is  the  default  session  keyring  for  a particular user. Login
       processes that change to a particular user will bind  to  this  session
       until another session is set.

       (*) Group specific keyring: @g or -6

       This  is  a  place  holder  for  a  group  specific keyring, but is not
       actually implemented yet in the kernel.

       (*) Assumed request_key authorisation key: @a or -7

       This selects the authorisation key provided to the request_key() helper
       to  permit it to access the callers keyrings and instantiate the target
       key.

COMMAND SYNTAX

       Any non-ambiguous shortening of a command name may be used in  lieu  of
       the full command name. This facility should not be used in scripting as
       new commands may be added in future that then cause ambiguity.

       (*) Show process keyrings

       keyctl show

       This command recursively shows what keyrings a process is subscribed to
       and what keys and keyrings they contain.

       (*) Add a key to a keyring

       keyctl add <type> <desc> <data> <keyring>
       keyctl padd <type> <desc> <keyring>

       This  command  creates  a  key  of  the specified type and description;
       instantiates it with the given data and attaches it  to  the  specified
       keyring. It then prints the new key’s ID on stdout:

              testbox>keyctl add user mykey stuff @u
              26

       The  padd  variant of the command reads the data from stdin rather than
       taking it from the command line:

              testbox>echo -n stuff | keyctl padd user mykey @u
              26

       (*) Request a key

       keyctl request <type> <desc> [<dest_keyring>]
       keyctl request2 <type> <desc> <info> [<dest_keyring>]
       keyctl prequest2 <type> <desc> [<dest_keyring>]

       These three commands request the lookup of a key of the given type  and
       description. The process’s keyrings will be searched, and if a match is
       found the matching key’s ID  will  be  printed  to  stdout;  and  if  a
       destination  keyring  is  given,  the key will be added to that keyring
       also.

       If there is no key, the first command  will  simply  return  the  error
       ENOKEY  and  fail.  The second and third commands will create a partial
       key with the type and description, and call  out  to  /sbin/request-key
       with  that  key  and  the  extra  information  supplied. This will then
       attempt to instantiate the key in some manner, such that a valid key is
       obtained.

       The  third  command  is  like  the  second,  except  that  the  callout
       information is read from stdin rather than being passed on the  command
       line.

       If a valid key is obtained, the ID will be printed and the key attached
       as if the original search had succeeded.

       If there wasn’t a valid key obtained, a temporary negative key will  be
       attached  to  the destination keyring if given and the error "Requested
       key not available" will be given.

              testbox>keyctl request2 user debug:hello wibble
              23
              testbox>echo -n wibble | keyctl prequest2 user debug:hello
              23
              testbox>keyctl request user debug:hello
              23

       (*) Update a key

       keyctl update <key> <data>
       keyctl pupdate <key>

       This command replaces the data attached to a key  with  a  new  set  of
       data.  If  the  type  of  the  key  doesn’t  support  update then error
       "Operation not supported" will be returned.

              testbox>keyctl update 23 zebra

       The pupdate variant of the command reads the  data  from  stdin  rather
       than taking it from the command line:

              testbox>echo -n zebra | keyctl pupdate 23

       (*) Create a keyring

       keyctl newring <name> <keyring>

       This  command  creates a new keyring of the specified name and attaches
       it to the specified keyring. The ID of the new keyring will be  printed
       to stdout if successful.

              testbox>keyctl newring squelch @us
              27

       (*) Revoke a key

       keyctl revoke <key>

       This  command  marks  a key as being revoked. Any further operations on
       that key (apart from unlinking it) will  return  error  "Key  has  been
       revoked".

              testbox>keyctl revoke 26
              testbox>keyctl describe 26
              keyctl_describe: Key has been revoked

       (*) Clear a keyring

       keyctl clear <keyring>

       This  command  unlinks  all the keys attached to the specified keyring.
       Error "Not a directory" will be returned if the key specified is not  a
       keyring.

              testbox>keyctl clear 27

       (*) Link a key to a keyring

       keyctl link <key> <keyring>

       This command makes a link from the key to the keyring if there’s enough
       capacity to do so. Error "Not a directory"  will  be  returned  if  the
       destination  is  not  a  keyring.  Error  "Permission  denied"  will be
       returned if the key doesn’t have link permission or the keyring doesn’t
       have  write permission. Error "File table overflow" will be returned if
       the keyring is full. Error "Resource deadlock avoided" will be returned
       if an attempt was made to introduce a recursive link.

              testbox>keyctl link 23 27
              testbox>keyctl link 27 27
              keyctl_link: Resource deadlock avoided

       (*) Unlink a key from a keyring

       keyctl unlink <key> <keyring>

       This  command  removes a link to the key from the keyring. Error "Not a
       directory" will be returned if the destination is not a keyring.  Error
       "Permission  denied" will be returned if the keyring doesn’t have write
       permission. Error "No such file or directory" will be returned  if  the
       key is not linked to by the keyring.

       Note  that this only removes one key link from the keyring; any further
       links to the same key are not deleted.

              testbox>keyctl unlink 23 27

       (*) Search a keyring

       keyctl search <keyring> <type> <desc> [<dest_keyring>]

       This command  non-recursively  searches  a  keyring  for  a  key  of  a
       particular  type  and  description. If found, the ID of the key will be
       printed on stdout and the key  will  be  attached  to  the  destination
       keyring  if  present.  Error  "Requested  key  not  available"  will be
       returned if the key is not found.

              testbox>keyctl search @us user debug:hello
              23
              testbox>keyctl search @us user debug:bye
              keyctl_search: Requested key not available

       (*) Read a key

       keyctl read <key>
       keyctl pipe <key>
       keyctl print <key>

       These commands read the payload of a key. "read" prints it on stdout as
       a hex dump, "pipe" dumps the raw data to stdout and "print" dumps it to
       stdout directly if it’s entirely printable or as a hexdump preceded  by
       ":hex:" if not.

       If  the  key  type  does not support reading of the payload, then error
       "Operation not supported" will be returned.

              testbox>keyctl read 26
              1 bytes of data in key:
              62
              testbox>keyctl print 26
              b
              testbox>keyctl pipe 26
              btestbox>

       (*) List a keyring

       keyctl list <keyring>
       keyctl rlist <keyring>

       These commands list the contents of a key as a keyring.  "list"  pretty
       prints the contents and "rlist" just produces a space-separated list of
       key IDs.

       No attempt is made to check that the specified keyring is a keyring.

              testbox>keyctl list @us
              2 keys in keyring:
                     22: vrwsl----------  4043    -1 keyring: _uid.4043
                     23: vrwsl----------  4043  4043 user: debug:hello
              testbox>keyctl rlist @us
              22 23

       (*) Describe a key

       keyctl describe <keyring>
       keyctl rdescribe <keyring> [sep]

       These commands fetch a description  of  a  keyring.  "describe"  pretty
       prints  the  description  in  the  same  fashion as the "list" command;
       "rdescribe" prints the raw data returned from the kernel.

              testbox>keyctl describe @us
                     -5: vrwsl----------  4043     -1  keyring:  _uid_ses.4043
              testbox>keyctl                   rdescribe                   @us
              keyring;4043;-1;3f1f0000;_uid_ses.4043

       The raw string is "<type>;<uid>;<gid>;<perms>;<description>", where uid
       and  gid  are  the decimal user and group IDs, perms is the permissions
       mask in hex, type and description are the  type  name  and  description
       strings (neither of which will contain semicolons).

       (*) Change the access controls on a key

       keyctl chown <key> <uid>
       keyctl chgrp <key> <gid>

       These  two commands change the UID and GID associated with evaluating a
       key’s permissions mask. The UID also governs which quota a key is taken
       out of.

       The  chown  command is not currently supported; attempting it will earn
       the error "Operation not supported" at best.

       For non-superuser users, the GID may only be set to the  process’s  GID
       or a GID in the process’s groups list. The superuser may set any GID it
       likes.

              testbox>sudo keyctl chown 27 0
              keyctl_chown: Operation not supported
              testbox>sudo keyctl chgrp 27 0

       (*) Set the permissions mask on a key

       keyctl setperm <key> <mask>

       This command changes the permission control mask on a key. The mask may
       be  specified  as a hex number if it begins "0x", an octal number if it
       begins "0" or a decimal number otherwise.

       The hex numbers are a combination of:

              Possessor UID       GID       Other     Permission Granted
              ========  ========  ========  ========  ==================
              01000000  00010000  00000100  00000001  View
              02000000  00020000  00000200  00000002  Read
              04000000  00040000  00000400  00000004  Write
              08000000  00080000  00000800  00000008  Search
              10000000  00100000  00001000  00000010  Link
              20000000  00200000  00002000  00000020  Set Attribute
              3f000000  003f0000  00003f00  0000003f  All

       View permits the type, description and other parameters of a key to  be
       viewed.

       Read  permits  the payload (or keyring list) to be read if supported by
       the type.

       Write permits the payload (or keyring list) to be modified or  updated.

       Search  on  a  key permits it to be found when a keyring to which it is
       linked is searched.

       Link permits a key to be linked to a keyring.

       Set Attribute permits a  key  to  have  its  owner,  group  membership,
       permissions mask and timeout changed.

              testbox>keyctl setperm 27 0x1f1f1f00

       (*) Start a new session with fresh keyrings

       keyctl session
       keyctl session - [<prog> <arg1> <arg2> ...]
       keyctl session <name> [<prog> <arg1> <arg2> ...]

       These  commands  join  or  create a new keyring and then run a shell or
       other program with that keyring as the session key.

       The variation with no  arguments  just  creates  an  anonymous  session
       keyring  and  attaches  that  as  the  session  keyring; it then exec’s
       $SHELL.

       The variation with a dash in place  of  a  name  creates  an  anonymous
       session  keyring  and  attaches  that  as  the session keyring; it then
       exec’s the supplied command, or $SHELL if one isn’t supplied.

       The variation with a name supplied creates or joins the  named  keyring
       and  attaches  that as the session keyring; it then exec’s the supplied
       command, or $SHELL if one isn’t supplied.

              testbox>keyctl rdescribe @s
              keyring;4043;-1;3f1f0000;_uid_ses.4043

              testbox>keyctl session
              Joined session keyring: 28
              testbox>keyctl rdescribe @s
              keyring;4043;4043;3f1f0000;_ses.24082

              testbox>keyctl session -
              Joined session keyring: 29
              testbox>keyctl rdescribe @s
              keyring;4043;4043;3f1f0000;_ses.24139

              testbox>keyctl session - keyctl rdescribe @s
              Joined session keyring: 30
              keyring;4043;4043;3f1f0000;_ses.24185

              testbox>keyctl session fish
              Joined session keyring: 34
              testbox>keyctl rdescribe @s
              keyring;4043;4043;3f1f0000;fish

              testbox>keyctl session fish keyctl rdesc @s
              Joined session keyring: 35
              keyring;4043;4043;3f1f0000;fish

       (*) Instantiate a key

       keyctl instantiate <key> <data> <keyring>
       keyctl pinstantiate <key> <keyring>
       keyctl negate <key> <timeout> <keyring>

       These commands are used to attach data to a partially set  up  key  (as
       created  by  the kernel and passed to /sbin/request-key). "instantiate"
       marks a key as being valid  and  attaches  the  data  as  the  payload.
       "negate"  marks a key as invalid and sets a timeout on it so that it’ll
       go away after a while.  This  prevents  a  lot  of  quickly  sequential
       requests  from  slowing the system down overmuch when they all fail, as
       all subsequent requests will then fail with error  "Requested  key  not
       found" until the negative key has expired.

       The newly instantiated key will be attached to the specified keyring.

       These  commands may only be run from the program run by request-key - a
       special authorisation key is set up by the kernel and attached  to  the
       request-key’s session keyring. This special key is revoked once the key
       to which it refers has been instantiated one way or another.

              testbox>keyctl instantiate $1 "Debug $3" $4
              testbox>keyctl negate $1 30 $4

       The pinstantiate variant of the  command  reads  the  data  from  stdin
       rather than taking it from the command line:

              testbox>echo -n "Debug $3" | keyctl pinstantiate $1 $4

       (*) Set the expiry time on a key

       keyctl timeout <key> <timeout>

       This  command is used to set the timeout on a key, or clear an existing
       timeout if the value specified is zero.  The  timeout  is  given  as  a
       number of seconds into the future.

              testbox>keyctl timeout $1 45

ERRORS

       There are a number of common errors returned by this program:

       "Not a directory" - a key wasn’t a keyring.

       "Requested key not found" - the looked for key isn’t available.

       "Key has been revoked" - a revoked key was accessed.

       "Key has expired" - an expired key was accessed.

       "Permission   denied"   -  permission  was  denied  by  a  UID/GID/mask
       combination.

SEE ALSO

       keyctl(1), request-key.conf(5)