SETKEY
Section: POSIX Programmer's Manual (3P)
Updated: 2017
Page Index
PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
NAME
setkey
--- set encoding key
(
CRYPT)
SYNOPSIS
#include <stdlib.h>
void setkey(const char *key);
DESCRIPTION
The
setkey()
function provides access to an implementation-defined encoding
algorithm. The argument of
setkey()
is an array of length 64 bytes containing only the bytes with numerical
value of 0 and 1. If this string is divided into groups of 8, the
low-order bit in each group is ignored; this gives a 56-bit key which
is used by the algorithm. This is the key that shall be used with the
algorithm to encode a string
block
passed to
encrypt().
The
setkey()
function shall not change the setting of
errno
if successful. An application wishing to check for error situations
should set
errno
to 0 before calling
setkey().
If
errno
is non-zero on return, an error has occurred.
The
setkey()
function need not be thread-safe.
RETURN VALUE
No values are returned.
ERRORS
The
setkey()
function shall fail if:
- ENOSYS
-
The functionality is not supported on this implementation.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
Decoding need not be implemented in all environments. This is related
to government restrictions in some countries on encryption and
decryption routines. Historical practice has been to ship a different
version of the encryption library without the decryption feature in the
routines supplied. Thus the exported version of
encrypt()
does encoding but not decoding.
RATIONALE
None.
FUTURE DIRECTIONS
A future version of the standard may mark this interface as obsolete
or remove it altogether.
SEE ALSO
crypt(),
encrypt()
The Base Definitions volume of POSIX.1-2017,
<stdlib.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
Any typographical or formatting errors that appear
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