keyctl_describe - Describe a key
long keyctl_describe(key_serial_t key, char *buffer,
long keyctl_describe_alloc(key_serial_t key, char **_buffer);
keyctl_describe() describes the attributes of a key as a NUL-terminated
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-
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
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.
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The key specified had been revoked.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.
This is a library function that can be found in libkeyutils. When
linking, -lkeyutils should be specified to the linker.