add_key − add a key to the kernel’s key management facility
#include <keyutils.h>
key_serial_t
add_key(const char *type, const char
*description,
const void *payload, size_t
plen,
key_serial_t keyring);
add_key() asks the kernel to create or update a key of the given type and description, instantiate it with the payload of length plen, and to attach it to the nominated keyring and to return its serial number.
The key type may reject the data if it’s in the wrong format or in some other way invalid.
If the destination keyring already contains a key that matches the specified type and description, then, if the key type supports it, that key will be updated rather than a new key being created; if not, a new key will be created and it will displace the link to the extant key from the keyring.
The destination
keyring serial number may be that of a valid keyring
to which the caller has write permission, or it may be a
special keyring ID:
KEY_SPEC_THREAD_KEYRING
This specifies the caller’s thread-specific keyring.
KEY_SPEC_PROCESS_KEYRING
This specifies the caller’s process-specific keyring.
KEY_SPEC_SESSION_KEYRING
This specifies the caller’s session-specific keyring.
KEY_SPEC_USER_KEYRING
This specifies the caller’s UID-specific keyring.
KEY_SPEC_USER_SESSION_KEYRING
This specifies the caller’s UID-session keyring.
There are a number of key types available in the core key management code, and these can be specified to this function:
“user” |
Keys of the user-defined key type may contain a blob of arbitrary data, and the description may be any valid string, though it is preferred that the description be prefixed with a string representing the service to which the key is of interest and a colon (for instance “afs:mykey”). The payload may be empty or NULL for keys of this type. |
“keyring”
Keyrings are special key types that may contain links to sequences of other keys of any type. If this interface is used to create a keyring, then a NULL payload should be specified, and plen should be zero.
On success add_key() returns the serial number of the key it created or updated. On error, the value −1 will be returned and errno will have been set to an appropriate error.
ENOKEY |
The keyring doesn’t exist. |
EKEYEXPIRED
The keyring has expired.
EKEYREVOKED
The keyring has been revoked.
EINVAL |
The payload data was invalid. | ||
ENOMEM |
Insufficient memory to create a key. | ||
EDQUOT |
The key quota for this user would be exceeded by creating this key or linking it to the keyring. | ||
EACCES |
The keyring wasn’t available for modification by the user. |
Although this is a Linux system call, it is not present in libc but can be found rather in libkeyutils. When linking, -lkeyutils should be specified to the linker.
keyctl(1), keyctl(2), request_key(2)
This page is part of release 3.69 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at http://www.kernel.org/doc/man−pages/.
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 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.
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.
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.