NAME

       keyctl_describe - Describe a key

SYNOPSIS

       #include <keyutils.h>

       long keyctl_describe(key_serial_t key, char *buffer,
       size_tbuflen);

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

DESCRIPTION

       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:

              “%s;%d;%d;%08x;%s”

       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

       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

       ENOKEY The key specified is invalid.

       EKEYEXPIRED
              The key specified has expired.

       EKEYREVOKED
              The key specified had been revoked.

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

LINKING

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

SEE ALSO

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