Keyctl

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TMP

Kernel-Keyring einsehen

Zur Überprüfung, welche Passphrasen im Kernel-Keyring geladen sind, kann der Befehl keyctl verwendet werden.

$ keyctl list @u

Manpage

KEYCTL(1)                            Linux Key Management Utilities                           KEYCTL(1)

NAME
       keyctl - key management facility control

SYNOPSIS
       keyctl --version
       keyctl supports [<cap> | --raw]
       keyctl id [<keyring>]
       keyctl show [-x] [<keyring>]
       keyctl add [-x] <type> <desc>  <keyring>
       keyctl padd [-x] <type> <desc> <keyring>
       keyctl request <type> <desc> [<dest_keyring>]
       keyctl request2 <type> <desc> <info> [<dest_keyring>]
       keyctl prequest2 <type> <desc> [<dest_keyring>]
       keyctl update [-x] <key> 
       keyctl pupdate [-x] <key>
       keyctl newring <name> <keyring>
       keyctl revoke <key>
       keyctl clear <keyring>
       keyctl link <key> <keyring>
       keyctl unlink <key> [<keyring>]
       keyctl move [-f] <key> <from_keyring> <to_keyring>
       keyctl search <keyring> <type> <desc> [<dest_keyring>]
       keyctl restrict_keyring <keyring> [<type> [<restriction>]]
       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 new_session [<name>]
       keyctl session
       keyctl session - [<prog> <arg1> <arg2> ...]
       keyctl session <name> [<prog> <arg1> <arg2> ...]
       keyctl instantiate [-x] <key>  <keyring>
       keyctl pinstantiate [-x] <key> <keyring>
       keyctl negate <key> <timeout> <keyring>
       keyctl reject <key> <timeout> <error> <keyring>
       keyctl timeout <key> <timeout>
       keyctl security <key>
       keyctl reap [-v]
       keyctl purge <type>
       keyctl purge [-i] [-p] <type> <desc>
       keyctl purge -s <type> <desc>
       keyctl get_persistent <keyring> [<uid>]
       keyctl dh_compute <private> <prime> <base>
       keyctl dh_compute_kdf <private> <prime> <base> <output_length> <hash_type>
       keyctl dh_compute_kdf_oi [-x] <private> <prime> <base> <output_length> <hash_type>
       keyctl pkey_query <key> <pass> [k=v]*
       keyctl pkey_encrypt <key> <pass> <datafile> [k=v]* ><encfile>
       keyctl pkey_decrypt <key> <pass> <encfile> [k=v]* ><datafile>
       keyctl pkey_sign <key> <pass> <datafile> [k=v]* ><sigfile>
       keyctl pkey_decrypt <key> <pass> <datafile> <sigfile> [k=v]*
       keyctl watch [-f<filters>] <key>
       keyctl watch_add <fd> <key>
       keyctl watch_rm <fd> <key>
       keyctl watch_session [-f <filters>] [-n <name>] \
                       <notifylog> <gclog> <fd> <prog> [<arg1> <arg2> ...]

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.

       Keyring by name: %:<name>
              A named keyring.  This will be searched for in the process's keyrings and in /proc/keys.

       Key by name: %<type>:<name>
              A named key of the given type.  This will be searched for in the process's  keyrings  and
              in /proc/keys.

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.

   Display the package version number
       keyctl --version

       This command prints the package version number and build date and exits:

              $ keyctl --version
              keyctl from keyutils-1.5.3 (Built 2011-08-24)

   Query subsystem capabilities
       keyctl supports
       keyctl supports --raw
       keyctl supports <cap>

       This command can list the available capabilities:

              $ keyctl supports
              have_capabilities=0
              have_persistent_keyrings=1
              have_dh_compute=1
              have_public_key=1

       produce a raw hex dump of the capabilities list:

              $ keyctl supports --raw
              ff0f

       or query a specific capability:

              $ keyctl supports pkey
              echo $?
              0

       which exits 0 if the capability is supported, 1 if it isn't and 3 if the name is not recognised.
       The capabilities supported are:

       capabilities
              The kernel supports capability querying.  If not, the other capabilities will be  queried
              as best libkeyutils can manage.

       persistent_keyrings
              The kernel supports persistent keyrings.

       dh_compute
              The kernel supports Diffie-Hellman computation operations.

       public_key
              The kernel supports public key operations.

       big_key_type
              The kernel supports the big_key key type.

       key_invalidate
              The kernel supports the invalidate key operaiton.

       restrict_keyring
              The kernel supports the restrict_keyring operation.

       move_key
              The kernel supports the move key operation.

       ns_keyring_name
              Keyring  names  are  segregated according to the user-namespace in which the keyrings are
              created.

       ns_key_tag
              Keys can get tagged with namespace tags, allowing keys with the same  type  and  descrip‐
              tion, but different namespaces to coexist in the same keyring.  Tagging is done automati‐
              cally according to the key type.

   Show actual key or keyring ID
       keyctl id [<key>]

       This command looks up the real ID of a key or keyring from the identifier given, which is  typi‐
       cally a symbolic ID such as "@s" indicating the session keyring, but can also be a numeric ID or
       "%type:desc" notation.  If a special keyring is specified that isn't created yet, an error  will
       be given rather than causing that keyring to be created.

   Show process keyrings
       keyctl show [-x] [<keyring>]

       By default this command recursively shows what keyrings a process is subscribed to and what keys
       and keyrings they contain.  If a keyring is specified then that keyring will be dumped  instead.
       If -x is specified then the keyring IDs will be dumped in hex instead of decimal.

   Add a key to a keyring
       keyctl add [-x] <type> <desc>  <keyring>
       keyctl padd [-x] <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:

              $ 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:

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

       If -x is given, then the data is hex-decoded with whitespace being discarded.

   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 destina‐
       tion keyring if given and the error "Requested key not available" will be given.

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

   Update a key
       keyctl update [-x] <key> 
       keyctl pupdate [-x] <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.

              $ keyctl update 23 zebra

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

              $ echo -n zebra | keyctl pupdate 23
              $ echo 616263313233 | keyctl pupdate -x 23

       If -x is given, then the data is hex-decoded with whitespace being discarded.

   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.

              $ 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 un‐
       linking it) will return error "Key has been revoked".

              $ keyctl revoke 26
              $ 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.

              $ 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  de‐
       nied" 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.

              $ keyctl link 23 27
              $ keyctl link 27 27
              keyctl_link: Resource deadlock avoided

   Unlink a key from a keyring or the session keyring tree
       keyctl unlink <key> [<keyring>]

       If the keyring is specified, 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.

       If the keyring is not specified, this command performs  a  depth-first  search  of  the  session
       keyring  tree  and removes all the links to the nominated key that it finds (and that it is per‐
       mitted to remove).  It prints the number of successful unlinks before exiting.

              $ keyctl unlink 23 27

   Move a key between keyrings.
       keyctl move  [-f] <key> <from_keyring> <to_keyring>

       This command moves a key from one keyring to another, atomically combining "keyctl unlink  <key>
       <from_keyring>" and "keyctl link <key> <to_keyring>".

       If  the  "-f"  flag  is  present,  any  matching key will be displaced from "to_keyring"; if not
       present, the command will fail with the error message "File exists" if the key  would  otherwise
       displace another key from "to_keyring".

              $ keyctl move 23 27 29
              $ keyctl move -f 71 @u @s

   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 desti‐
       nation  keyring  if  present. Error "Requested key not available" will be returned if the key is
       not found.

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

   Restrict a keyring
       keyctl restrict_keyring <keyring> [<type> [<restriction>]]

       This command limits the linkage of keys to  the  given  keyring  using  a  provided  restriction
       scheme. The scheme is associated with a given key type, with further details provided in the re‐
       striction option string.  Options typically contain a restriction name possibly followed by  key
       ids or other data relevant to the restriction. If no restriction scheme is provided, the keyring
       will reject all links.

              $ keyctl restrict_keyring $1 asymmetric builtin_trusted

   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.

              $ keyctl read 26
              1 bytes of data in key:
              62
              $ keyctl print 26
              b
              $ keyctl pipe 26
              $

   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.

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

              $ keyctl describe @us
                     -5: vrwsl----------  4043    -1 keyring: _uid_ses.4043
              $ 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.

              $ sudo keyctl chown 27 0
              keyctl_chown: Operation not supported
              $ 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.

              $ 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 sup‐
       plied.

       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.

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

              $ keyctl session
              Joined session keyring: 28

              $ keyctl rdescribe @s
              keyring;4043;4043;3f1f0000;_ses.24082

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

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

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

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

   Instantiate a key
       keyctl instantiate [-x] <key>  <keyring>
       keyctl pinstantiate [-x] <key> <keyring>
       keyctl negate <key> <timeout> <keyring>
       keyctl reject <key> <timeout> <error> <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" and "reject" mark 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 sys‐
       tem  down overmuch when they all fail, as all subsequent requests will then fail with error "Re‐
       quested key not found" (if negated) or the specified error (if rejected) until the negative  key
       has expired.

       Reject's  error  argument  can  either be a UNIX error number or one of 'rejected', 'expired' or
       'revoked'.

       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.

              $ keyctl instantiate $1 "Debug $3" $4
              $ keyctl negate $1 30 $4
              $ keyctl reject $1 30 64 $4

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

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

       If -x is given, then the data is hex-decoded with whitespace being discarded:

              $ echo 01 02 03 04 | keyctl pinstantiate -x $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.

              $ keyctl timeout $1 45

   Retrieve a key's security context
       keyctl security <key>

       This command is used to retrieve a key's LSM security context.  The label is printed on stdout.

              $ keyctl security @s
              unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023

   Give the parent process a new session keyring
       keyctl new_session [<name>]

       This command is used to give the invoking process (typically a shell)  a  new  session  keyring,
       discarding  its old session keyring.  If a name is given, the keyring is given that name, other‐
       wise it will be given a name of "_ses" and will not be manually joinable.

              $  keyctl session foo
              Joined session keyring: 723488146
              $  keyctl show
              Session Keyring
                     -3 --alswrv      0     0  keyring: foo
              $  keyctl new_session
              490511412
              $  keyctl show
              Session Keyring
                     -3 --alswrv      0     0  keyring: _ses

       Note that this affects the parent of the process that invokes the system call, and so  may  only
       affect  processes  with matching credentials.  Furthermore, the change does not take effect till
       the parent process next transitions from kernel space to user space - typically when the  wait()
       system call returns.

   Remove dead keys from the session keyring tree
       keyctl reap

       This  command performs a depth-first search of the caller's session keyring tree and attempts to
       unlink any key that it finds that is inaccessible due to expiry, revocation, rejection or  nega‐
       tion.   It  does  not  attempt  to remove live keys that are unavailable simply due to a lack of
       granted permission.

       A key that is designated reapable will only be removed from a keyring if the  caller  has  Write
       permission on that keyring, and only keyrings that grant Search permission to the caller will be
       searched.

       The command prints the number of keys reaped before it exits.  If the -v flag is passed then the
       reaped  keys are listed as they're being reaped, together with the success or failure of the un‐
       link.

   Remove matching keys from the session keyring tree
       keyctl purge <type>
       keyctl purge [-i] [-p] <type> <desc>
       keyctl purge -s <type> <desc>

       These commands perform a depth-first search to  find  matching  keys  in  the  caller's  session
       keyring  tree  and attempts to unlink them.  The number of keys successfully unlinked is printed
       at the end.

       The keyrings must grant Read and View permission to the caller to be searched, and the  keys  to
       be  removed  must also grant View permission.  Keys can only be removed from keyrings that grant
       Write permission.

       The first variant purges all keys of the specified type.

       The second variant purges all keys of the specified type that also match the  given  description
       literally.  The -i flag allows a case-independent match and the -p flag allows a prefix match.

       The  third  variant purges all keys of the specified type and matching description using the key
       type's comparator in the kernel to match the description.  This permits the key type to match  a
       key with a variety of descriptions.

   Get persistent keyring
       keyctl get_persistent <keyring> [<uid>]

       This command gets the persistent keyring for either the current UID or the specified UID and at‐
       taches it to the nominated keyring.  The persistent keyring's ID will be printed on stdout.

       The kernel will create the keyring if it doesn't exist and every time this  command  is  called,
       will reset the expiration timeout on the keyring to the value in:

              /proc/sys/kernel/keys/persistent_keyring_expiry

       (by  default three days).  Should the timeout be reached, the persistent keyring will be removed
       and everything it pins can then be garbage collected.

       If a UID other than the process's real or effective UIDs is specified, then  an  error  will  be
       given if the process does not have the CAP_SETUID capability.

   Compute a Diffie-Hellman shared secret or public key
       keyctl dh_compute <private> <prime> <base>

       This  command  computes either a Diffie-Hellman shared secret or the public key corresponding to
       the provided private key using the payloads of three keys. The computation is:

              base ^ private (mod prime)

       The three inputs must be user keys with read permission. If the provided base key  contains  the
       shared  generator value, the public key will be computed.  If the provided base key contains the
       remote public key value, the shared secret will be computed.

       The result is printed to stdout as a hex dump.

              $ keyctl dh_compute $1 $2 $3
              8 bytes of data in result:
              00010203 04050607

   Compute a Diffie-Hellman shared secret and derive key material
       keyctl dh_compute_kdf <private> <prime> <base> <output_length> <hash_type>

       This command computes a Diffie-Hellman shared secret and derives key material  from  the  shared
       secret  using  a  key derivation function (KDF).  The shared secret is derived as outlined above
       and is input to the KDF using the specified hash type. The hash type must point to a  hash  name
       known to the kernel crypto API.

       The operation derives key material of the length specified by the caller.

       The operation is compliant to the specification of SP800-56A.

       The result is printed to stdout as hex dump.

   Compute a Diffie-Hellman shared secret and apply KDF with other input
       keyctl dh_compute_kdf_oi [-x] <private> <prime> <base> <output_length> <hash_type>

       This  command is identical to the command dh_compute_kdf to generate a Diffie-Hellman shared se‐
       cret followed by a key derivation operation. This command allows the caller to provide the other
       input data (OI data) compliant to SP800-56A via stdin.

       If -x is given, then the data passed to stdin is hex-decoded with whitespace being discarded.

   Perform public-key operations with an asymmetric key
       keyctl pkey_query <key> <pass> [k=v]*
       keyctl pkey_encrypt <key> <pass> <datafile> [k=v]* > <encfile>
       keyctl pkey_decrypt <key> <pass> <encfile> [k=v]* > <datafile>
       keyctl pkey_sign <key> <pass> <datafile> [k=v]* > <sigfile>
       keyctl pkey_verify <key> <pass> <datafile> <sigfile> [k=v]*

       These commands query an asymmetric key, encrypt data with it, decrypt the encrypted data, gener‐
       ate a signature over some data and verify that signature.  For encrypt, decrypt  and  sign,  the
       resulting  data is written to stdout; verify reads the data and the signature files and compares
       them.

       [!] NOTE that the data is of very limited capacity, with no more bits than the size of the  key.
       For  signatures,  the caller is expected to digest the actual data and pass in the result of the
       digest as the datafile.  The name of the digest should be specified on the end  of  the  command
       line as "hash=<name>".

       The  key  ID  indicates  the key to use; pass is a placeholder for future password provision and
       should be "0" for the moment; datafile is the unencrypted data to be  encrypted,  signed  or  to
       have  its  signature checked; encfile is a file containing encrypted data; and sigfile is a file
       containing a signature.

       A list of parameters in "key[=val]" form can be included on the end of the command line.   These
       specify   things   like   the  digest  algorithm  used  ("hash=<name>")  or  the  encoding  form
       ("enc=<type>").

              k=`keyctl padd asymmetric "" @s <key.pkcs8.der`
              keyctl pkey_query $k 0 enc=pkcs1 hash=sha256
              keyctl pkey_encrypt $k 0 foo.hash enc=pkcs1 >foo.enc
              keyctl pkey_decrypt $k 0 foo.enc enc=pkcs1 >foo.hash
              keyctl pkey_sign $k 0 foo.hash enc=pkcs1 hash=sha256 >foo.sig
              keyctl pkey_verify $k 0 foo.hash foo.sig enc=pkcs1 hash=sha256

       See asymmetric-key(7) for more information.

   Change notifications
       keyctl watch [-f<filters>] <key>
       keyctl watch_session [-f <filters>] [-n <name>] \
                       <notifylog> <gclog> <fd> <prog> [<arg1> <arg2> ...]  keyctl watch_add <fd> <key>
       keyctl watch_rm <fd> <key>

       The watch command watches a single key, printing notifications to stdout until the  key  is  de‐
       stroyed.   Filters  can  be  employed to cut down the events that will be delivered.  The filter
       string is a series of letters, each one of which enables a particular event subtype:

              i - The key has been instantiated
              p - The key has been updated
              l - A link has been added to a keyring
              n - A link has been removed from a keyring
              c - A keyring has been cleared
              r - A key has been revoked
              v - A key has been invalidated
              s - A key has had its attributes changed

       The output of the command looks like:

              <keyid> <event> [<aux>]

       Where keyid is the primary subject of the notification, op is the event and aux is the secondary
       key  if there is one (such as link where the primary key is the keyring secondary key is the key
       being linked in to it).  For example:

              255913279 link 340681059
              255913279 clr

       An additional notication is generated when a key being watched is garbage collected, e.g.:

              255913279 gc

       The watch_session command creates a new session keyring, with name name if given, watches it for
       notifications and runs program prog with it.  The program is given the specified arguments.

       A  second  process is forked off to monitor the notifications.  The output from that is directed
       to the files notifylog for most notifications and gclog for key removal notifications (which are
       asynchronous and may be deferred).

       The  watch_queue(7)  device  is  exported  to the program attached to fd number fd.  This can be
       passed by the other two commands.

       The watch_add command adds a watch on key to the watch_queue  attached  to  fd  as  exported  by
       watch_session  and the watch_rm caommand removes it.  A watch_queue can handle multiple keys and
       even non-keys sources as well.

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), keyctl(2), request_key(2), keyctl(3), request-key.conf(5), keyrings(7),
       request-key(8)

Linux                                         20 Feb 2014                                     KEYCTL(1)