/*************************************************
*     Exim - an Internet mail transport agent    *
*************************************************/

/*
Copyright (c) The Exim Maintainers 2024 - 2026
Copyright (c) 2000-2002
  Chris Adams <cmadams@iruntheinter.net>
  written for HiWAAY Internet Services
SPDX-License-Identifier: GPL-2.0-or-later

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, see <https://www.gnu.org/licenses/>.
*/

/*
Adapted for Exim by Tamas TEVESZ <ice@extreme.hu>
Further adapted by Philip Hazel to cut out this function for operating
  systems that have a built-in version.
*/

/* The OS has a built-in crypt16(). Some compilers don't like compiling empty
modules, so keep them happy with a dummy when skipping the rest. */

#include "config.h"

#ifdef HAVE_CRYPT16
static void dummy(int x) { dummy(x-1); }
#else

/* The OS doesn't have a built-in crypt16(). Compile this one. */

#include <unistd.h>
#include <string.h>
#include "os.h"

#ifdef CRYPT_H
#include <crypt.h>
#endif

char *
crypt16(char * key, char * salt)
{
static char res[25];	/* Not threadsafe; like crypt() */
const char * p;

/* Clear the string of any previous data */
memset (res, 0, sizeof (res));

/* crypt the first part */
if (!(p = crypt (key, salt))) return NULL;
strncpy (res, p, 13);

if (strlen (key) > 8)
  {
  static char s2[3];
  /* crypt the rest
  the first two characters of the first block (not counting
  the salt) make up the new salt */

  strncpy (s2, res+2, 2);
  p = crypt (key+8, s2);
  strncpy (res+13, p+2, 11);
  memset (s2, 0, sizeof(s2));
  }

return (res);
}
#endif

/* End of crypt16.c */
