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.
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.
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.
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) 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.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the
source files to man page format. To report such errors, see
IEEE/The Open Group 2013 SETKEY(3P)