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NAME | SYNOPSIS | DESCRIPTION | KEY IDENTIFIERS | COMMAND SYNTAX | ERRORS | SEE ALSO | COLOPHON |
KEYCTL(1) Linux Key Management Utilities KEYCTL(1)
keyctl - key management facility control
keyctl --version
keyctl supports [<cap> | --raw]
keyctl id [<keyring>]
keyctl show [-x] [<keyring>]
keyctl add [-x] <type> <desc> <data> <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> <data>
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> <data> <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> ...]
This program is used to control the key management facility in
various ways using a variety of subcommands.
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.
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 description, but different namespaces to
coexist in the same keyring. Tagging is done automatically
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 typically 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> <data> <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 destination 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> <data>
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 command 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 unlinking 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 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.
$ 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 permitted 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 destination
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 restriction 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 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.
$ 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> <data> <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 system down
overmuch when they all fail, as all subsequent requests will then
fail with error "Requested 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, otherwise 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 negation. 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 unlink.
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 attaches 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 secret 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, generate 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 destroyed. 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.
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.
keyctl(1), keyctl(2), request_key(2), keyctl(3), request-key.conf(5),
keyrings(7), request-key(8)
This page is part of the keyutils (key management utilities) project.
Information about the project can be found at [unknown -- if you
know, please contact man-pages@man7.org] If you have a bug report for
this manual page, send it to keyrings@linux-nfs.org. This page was
obtained from the project's upstream Git repository
⟨http://git.kernel.org/pub/scm/linux/kernel/git/dhowells/keyutils.git⟩
on 2020-08-13. (At that time, the date of the most recent commit
that was found in the repository was 2020-07-07.) If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
to man-pages@man7.org
Linux 20 Feb 2014 KEYCTL(1)
Pages that refer to this page: keyctl(1) , systemd-ask-password(1) , add_key(2) , keyctl(2) , request_key(2) , keyctl(3) , keyctl_assume_authority(3) , keyctl_capabilities(3) , keyctl_chown(3) , keyctl_clear(3) , keyctl_describe(3) , keyctl_dh_compute(3) , keyctl_dh_compute_kdf(3) , keyctl_get_keyring_id(3) , keyctl_get_keyring_ID(3) , keyctl_get_persistent(3) , keyctl_get_security(3) , keyctl_instantiate(3) , keyctl_instantiate_iov(3) , keyctl_invalidate(3) , keyctl_join_session_keyring(3) , keyctl_link(3) , keyctl_move(3) , keyctl_negate(3) , keyctl_pkey_decrypt(3) , keyctl_pkey_encrypt(3) , keyctl_pkey_query(3) , keyctl_pkey_sign(3) , keyctl_pkey_verify(3) , keyctl_read(3) , keyctl_reject(3) , keyctl_restrict_keyring(3) , keyctl_revoke(3) , keyctl_search(3) , keyctl_session_to_parent(3) , keyctl_setperm(3) , keyctl_set_reqkey_keyring(3) , keyctl_set_timeout(3) , keyctl_unlink(3) , keyctl_update(3) , keyctl_watch_key(3) , request-key.conf(5) , asymmetric(7) , asymmetric-key(7) , keyrings(7) , keyutils(7) , persistent-keyring(7) , process-keyring(7) , session-keyring(7) , thread-keyring(7) , user-keyring(7) , user-session-keyring(7) , e4crypt(8) , pam_keyinit(8) , request-key(8)