KEYCTL_DESCRIBE
KEYCTL_DESCRIBE
NAMESYNOPSIS
DESCRIPTION
RETURN VALUE
ERRORS
LINKING
SEE ALSO
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The key specified had been revoked.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)
Opportunity
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
Free Books
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Education
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.
