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  reentrant. A function that is not required to be reentrant is not
       required to 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

       None.

SEE ALSO

       crypt() , encrypt() , the Base Definitions volume of IEEE Std 1003.1-2001, <stdlib.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition,
       Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open  Group  Base
       Specifications Issue 6, Copyright (C) 2001-2003 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 .

IEEE/The Open Group                                   2003                                             SETKEY(P)