keyctl_describe(3) — Linux manual page


KEYCTL_DESCRIBE(3)       Linux Key Management Calls       KEYCTL_DESCRIBE(3)

NAME         top

       keyctl_describe - describe a key

SYNOPSIS         top

       #include <keyutils.h>

       long keyctl_describe(key_serial_t key, char *buffer,

       long keyctl_describe_alloc(key_serial_t key, char **_buffer);

DESCRIPTION         top

       keyctl_describe() describes the attributes of a key as a NUL-
       terminated string.

       The caller must have view permission on a key to be able to get a
       description of it.

       buffer and buflen specify the buffer into which the key description
       will be placed.  If the buffer is too small, the full size of the
       description will be returned, and no copy will take place.

       keyctl_describe_alloc() is similar to keyctl_describe() except that
       it allocates a buffer big enough to hold the description and places
       the description in it.  If successful, A pointer to the buffer is
       placed in *_buffer.  The caller must free the buffer.

       The description will be a string of format:


       where the arguments are: key type name, key UID, key GID, key
       permissions mask and key description.

       NOTE!  The key description will not contain any semicolons, so that
       should be separated out by working backwards from the end of the
       string.  This permits extra information to be inserted before it by
       later versions of the kernel simply by inserting more semicolon-
       terminated substrings.

RETURN VALUE         top

       On success keyctl_describe() returns the amount of data placed into
       the buffer.  If the buffer was too small, then the size of buffer
       required will be returned, but no data will be transferred.  On
       error, the value -1 will be returned and errno will have been set to
       an appropriate error.

       On success keyctl_describe_alloc() returns the amount of data in the
       buffer, less the NUL terminator.  On error, the value -1 will be
       returned and errno will have been set to an appropriate error.

ERRORS         top

       ENOKEY The key specified is invalid.

              The key specified has expired.

              The key specified had been revoked.

       EACCES The key exists, but is not viewable by the calling process.

LINKING         top

       This is a library function that can be found in libkeyutils.  When
       linking, -lkeyutils should be specified to the linker.

SEE ALSO         top

       keyctl(1), add_key(2), keyctl(2), request_key(2), keyctl(3),
       keyrings(7), keyutils(7)

COLOPHON         top

       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] If you have a bug report for
       this manual page, send it to  This page was
       obtained from the project's upstream Git repository
       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

Linux                            4 May 2006               KEYCTL_DESCRIBE(3)

Pages that refer to this page: keyctl(2)keyctl(3)keyrings(7)