ENCRYPT(3)                 POSIX Programmer's Manual                ENCRYPT(3)



PROLOG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

NAME
       encrypt -- encoding function (CRYPT)

SYNOPSIS
       #include <unistd.h>

       void encrypt(char block[64], int edflag);

DESCRIPTION
       The encrypt() function shall provide access to an implementation-
       defined encoding algorithm. The key generated by setkey() is used to
       encrypt the string block with encrypt().

       The block argument to encrypt() shall be an array of length 64 bytes
       containing only the bytes with values of 0 and 1. The array is modified
       in place to a similar array using the key set by setkey().  If edflag
       is 0, the argument is encoded. If edflag is 1, the argument may be
       decoded (see the APPLICATION USAGE section); if the argument is not
       decoded, errno shall be set to [ENOSYS].

       The encrypt() 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 encrypt().  If errno is non-zero on
       return, an error has occurred.

       The encrypt() function need not be thread-safe.

RETURN VALUE
       The encrypt() function shall not return a value.

ERRORS
       The encrypt() function shall fail if:

       ENOSYS The functionality is not supported on this implementation.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       Historical implementations of the encrypt() function used a rather
       primitive encoding algorithm.

       In some environments, decoding might not be implemented. This is
       related to some Government restrictions 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(), setkey()

       The Base Definitions volume of POSIX.1-2017, <unistd.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 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
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017                           ENCRYPT(3)
