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

       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              The key specified had been revoked.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

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
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       bug report for this manual page, send it to  This page was obtained from the
       project's upstream Git repository
       on 2023-12-22.  (At that time, the date of the most recent commit
       that was found in the repository was 2023-03-20.)  If you
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       manual page), send a mail to

Linux                          4 May 2006             KEYCTL_DESCRIBE(3)

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