Section: POSIX Programmer's Manual (3P)
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.
--- set encoding key
void setkey(const char *key);
function provides access to an implementation-defined encoding
algorithm. The argument of
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
function shall not change the setting of
if successful. An application wishing to check for error situations
to 0 before calling
is non-zero on return, an error has occurred.
function need not be thread-safe.
No values are returned.
function shall fail if:
The functionality is not supported on this implementation.
The following sections are informative.
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
does encoding but not decoding.
A future version of the standard may mark this interface as obsolete
or remove it altogether.
The Base Definitions volume of POSIX.1-2017,
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
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