add_key(2)                    System Calls Manual                   add_key(2)

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       add_key - <?><?><?><?><?><?><?><?> <?><?><?><?> <?>
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       <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?> C (libc, -lc)

<?><?><?><?><?><?><?><?><?>
       #include <keyutils.h>

       key_serial_t add_key(size_t size;
                            const char *type, const char *description,
                            const void payload[size], size_t size,
                            key_serial_t keyring);

       <?><?><?><?><?><?><?><?><?>: <?> glibc <?><?><?>
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       <?><?><?><?><?><?>; <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?>.

<?><?><?><?><?><?><?><?>
       add_key()  creates or updates a key of the given type and description,
       instantiates it with the payload of size size, attaches it to the
       nominated keyring, and returns the key's serial number.

       <?><?><?><?> <?><?><?><?><?> <?><?><?><?> <?><?><?><?><?><?><?><?>,
       <?><?><?><?> <?><?><?> <?><?><?><?><?><?>
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       <?><?><?><?> <?> <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?> keyring <?><?><?> <?><?><?><?> <?><?><?><?> <?>
       <?><?><?><?><?> <?><?> type <?> description <?><?>, <?><?><?><?>
       <?><?><?> <?><?><?><?><?> <?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?>, <?><?><?><?> <?><?><?><?><?>
       <?><?><?><?><?><?><?><?>, <?> <?><?> <?><?><?><?><?><?>
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       <?><?><?><?><?><?> <?><?><?><?><?> <?><?><?><?> (<?> <?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>) <?> <?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?><?><?> <?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?> <?><?>
       <?><?><?><?><?><?>.

       <?><?><?><?><?><?> <?><?><?><?><?><?> keyring <?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?> <?><?><?><?><?><?>, <?><?><?> <?><?><?><?><?><?><?>
       <?> <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?> <?><?><?><?><?>
       <?><?> <?><?><?><?><?><?>. <?><?><?> <?><?> <?><?><?> <?><?><?><?><?>
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       <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?>:

       KEY_SPEC_THREAD_KEYRING
              <?><?><?><?><?><?> <?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?> <?><?><?><?> (thread-keyring(7)).

       KEY_SPEC_PROCESS_KEYRING
              <?><?><?><?><?><?> <?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
              (process-keyring(7)).

       KEY_SPEC_SESSION_KEYRING
              <?><?><?><?><?><?> <?><?><?><?><?><?> <?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?> (session-keyring(7)).

       KEY_SPEC_USER_KEYRING
              <?><?><?><?><?><?> <?><?><?><?><?><?> <?><?> UID
              <?><?><?><?><?><?><?><?><?><?><?> (user-keyring(7)).

       KEY_SPEC_USER_SESSION_KEYRING
              <?><?><?><?><?><?> <?><?><?><?><?><?> <?><?> UID
              <?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?>
              (user-session-keyring(7)).

   <?><?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?> type <?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?>
       <?><?><?><?><?><?>, <?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?> <?><?><?><?><?>.
       <?><?><?><?><?><?> <?><?><?><?> <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?> <?><?><?><?><?><?>,
       <?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?> <?> <?><?><?><?>
       <?><?><?><?> <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?>. <?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?><?><?><?><?>
       type <?><?><?> <?><?><?><?><?><?> add_key() <?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?>:

       "keyring"
              Keyrings are special key types that may contain links to
              sequences of other keys of any type.  If this interface is used
              to create a keyring, then payload should be NULL and size should
              be zero.

       "user" <?><?><?> <?><?><?><?><?> <?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?>, <?><?><?>
              <?><?><?><?><?><?><?><?> <?><?><?><?><?><?> <?><?><?><?><?>
              <?><?><?><?><?><?> <?> <?><?><?><?><?><?><?><?><?> <?><?>
              <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?>. <?><?><?><?>
              <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?> <?>
              <?><?><?><?><?><?> <?><?><?><?>. <?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?> <?><?><?><?><?><?> <?><?><?><?><?>
              <?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?>
              <?><?><?><?><?> <?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?>
              (blob) <?><?><?><?><?><?><?><?> <?><?> 32767 <?><?><?><?>.

       "logon" (<?><?><?><?><?><?><?> <?> Linux 3.3)
              This key type is essentially the same as "user", but it does not
              permit the key to read.  This is suitable for storing payloads
              that you do not want to be readable from user space.

       <?><?><?> <?><?><?><?><?><?><?> <?><?><?><?> <?><?><?><?><?>
       <?><?><?><?><?><?><?><?> description <?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?> <<service>>,
       <?><?><?><?><?><?><?> <?> description <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?> <<:>> <?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?>.

       "big_key" (<?><?><?><?><?><?><?> <?> Linux 3.13)
              This key type is similar to "user", but may hold a payload of up
              to 1 MiB.  If the key payload is large enough, then it may be
              stored encrypted in tmpfs (which can be swapped out) rather than
              kernel memory.

       <?><?><?><?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?><?> <?><?><?><?> <?><?><?><?><?>
       <?><?><?><?><?><?> <?><?><?><?><?><?><?><?> <?> keyrings(7).

<?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
       On success, add_key()  returns the serial number of the key it created
       or updated.  On error, -1 is returned and errno is set to indicate the
       error.

<?><?><?><?><?><?>
       EACCES <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
              <?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?>.

       EDQUOT <?><?><?><?><?> <?><?> <?><?><?><?><?> <?><?><?>
              <?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?>
              <?><?><?><?> <?><?> <?><?><?><?><?><?><?><?><?>, <?><?><?><?>
              <?><?> <?><?><?><?> <?><?><?><?> <?><?><?><?><?><?><?><?>
              <?><?><?> <?><?><?> <?><?> <?><?><?><?><?><?><?><?><?> <?>
              <?><?><?><?><?><?> <?><?><?><?><?><?>.

       EFAULT <?><?><?><?><?><?><?><?> <?><?><?><?><?><?> <?><?><?>
              <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?> <?><?> type,
              description <?> payload <?><?><?><?><?><?><?><?><?> <?><?><?>
              <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>.

       EINVAL <?><?><?><?><?><?> <?><?><?><?><?><?> (<?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?> <?><?><?><?> null),
              <?><?><?><?><?><?><?><?> <?> type <?><?><?> description,
              <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?>
              (32 <?><?><?><?><?> <?> 4096 <?><?><?><?>,
              <?><?><?><?><?><?><?><?><?><?><?><?><?><?>).

       EINVAL <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
              <?><?><?><?><?><?><?><?> <?><?><?><?><?><?>.

       EINVAL type was "logon" and the description was not qualified with a
              prefix string of the form "service:".

       EKEYEXPIRED
              <?><?><?><?> <?><?><?><?><?><?> <?><?><?><?><?><?>
              <?><?><?><?><?><?> <?><?><?><?><?>.

       EKEYREVOKED
              <?><?><?><?><?><?> <?><?><?><?><?><?> <?><?><?><?><?><?><?><?>.

       ENOKEY <?><?><?><?><?><?> <?><?><?><?><?><?> <?><?>
              <?><?><?><?><?><?><?><?><?><?>.

       ENOMEM <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
              <?><?><?> <?><?><?><?><?><?><?><?> <?><?><?><?><?>.

       EPERM  The type started with a period ('.').  Key types that begin with
              a period are reserved to the implementation.

       EPERM  type was "keyring" and the description started with a period
              ('.').  Keyrings with descriptions (names)  that begin with a
              period are reserved to the implementation.

<?><?><?><?><?><?><?><?><?>
       Linux.

<?><?><?><?><?><?><?>
       Linux 2.6.10.

<?><?><?><?><?><?><?><?><?><?>
       glibc does not provide a wrapper for this system call.  A wrapper is
       provided in the libkeyutils library.  (The accompanying package
       provides the <keyutils.h> header file.)  When employing the wrapper in
       that library, link with -lkeyutils.

<?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?>, <?><?><?><?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?>, <?><?><?><?><?><?><?> <?><?><?><?> <?> <?><?><?><?><?>,
       <?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?>, <?><?><?><?><?><?><?><?><?><?> <?>
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?>, <?> <?> <?><?><?><?><?><?><?> <?><?><?><?>
       <?><?><?><?> <?> <?><?><?><?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?>. <?><?><?><?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?>:

           $ ./a.out user mykey "Some payload";
           Key ID is 64a4dca
           $ grep '64a4dca' /proc/keys;
           064a4dca I--Q---    1 perm 3f010000  1000  1000 user    mykey: 12

   <?><?><?><?><?><?><?><?> <?><?><?> <?><?><?><?><?><?><?><?><?>
       #include <keyutils.h>
       #include <stdint.h>
       #include <stdio.h>
       #include <stdlib.h>
       #include <string.h>

       int
       main(int argc, char *argv[])
       {
           key_serial_t key;

           if (argc != 4) {
               fprintf(stderr, "Usage: %s type description payload\n",
                       argv[0]);
               exit(EXIT_FAILURE);
           }

           key = add_key(argv[1], argv[2], argv[3], strlen(argv[3]),
                         KEY_SPEC_SESSION_KEYRING);
           if (key == -1) {
               perror("add_key");
               exit(EXIT_FAILURE);
           }

           printf("Key ID is %jx\n", (uintmax_t) key);

           exit(EXIT_SUCCESS);
       }

<?><?><?><?><?><?><?><?> <?><?><?><?><?>
       keyctl(1), keyctl(2), request_key(2), keyctl(3), keyrings(7),
       keyutils(7), persistent-keyring(7), process-keyring(7),
       session-keyring(7), thread-keyring(7), user-keyring(7),
       user-session-keyring(7)

       The kernel source files Documentation/security/keys/core.rst and
       Documentation/keys/request-key.rst.

<?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?> <?><?><?><?><?><?><?> <?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?>(<?>) Dmitry Bolkhovskikh
       <d20052005@yandex.ru> <?> Yuri Kozlov <yuray@komyakino.ru>

       <?><?><?><?> <?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
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       <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?> GNU (GNU General Public License - GPL,
       <https://www.gnu.org/licenses/gpl-3.0.html> <?><?><?><?><?><?> 3
       <?><?><?> <?><?><?><?><?> <?><?><?><?><?><?><?>) <?>
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?>, <?><?> <?><?><?> <?><?><?><?><?>-<?><?><?><?>
       <?><?><?><?><?><?><?><?>.

       <?><?><?><?> <?><?> <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?>-<?><?><?><?> <?><?><?><?><?><?> <?>
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       <?><?><?><?><?><?><?><?><?><?><?>, <?><?><?><?><?><?><?><?><?><?>,
       <?><?><?><?><?><?><?><?> <?><?> <?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?>(<?><?>) <?><?> <?><?><?>(<?><?>)
       <?><?><?><?><?><?>(<?><?>) <?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?> <?><?><?> <?><?> <?><?><?><?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?>
       <debian-l10n-russian@lists.debian.org>.

Linux man-pages 6.18   8 <?><?><?><?><?><?><?> 2026 <?>.            add_key(2)