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              The key specified had been revoked.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), keyrings(7), keyutils(7)