/*
  Copyright (C) 1996-2025 Free Software Foundation, Inc.

  This file is part of GNU Inetutils.

  GNU Inetutils 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 3 of the License, or (at
  your option) any later version.

  GNU Inetutils 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 `http://www.gnu.org/licenses/'. */

/*
 * Copyright (c) 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Copyright (C) 1990 by the Massachusetts Institute of Technology
 *
 * Export of this software from the United States of America is assumed
 * to require a specific license from the United States Government.
 * It is the responsibility of any person or organization contemplating
 * export to obtain such a license before exporting.
 *
 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
 * distribute this software and its documentation for any purpose and
 * without fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright notice and
 * this permission notice appear in supporting documentation, and that
 * the name of M.I.T. not be used in advertising or publicity pertaining
 * to distribution of the software without specific, written prior
 * permission.  M.I.T. makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is" without express
 * or implied warranty.
 */

#ifdef	ENCRYPTION
# ifndef __ENCRYPTION__
#  define __ENCRYPTION__

#  define DIR_DECRYPT		1
#  define DIR_ENCRYPT		2

/* Cope with variants of <arpa/telnet.h>.  */
#  if !defined ENCTYPE_ANY && defined TELOPT_ENCTYPE_NULL
#   define ENCTYPE_ANY TELOPT_ENCTYPE_NULL
#  endif
#  if !defined ENCTYPE_DES_CFB64 && defined TELOPT_ENCTYPE_DES_CFB64
#   define ENCTYPE_DES_CFB64 TELOPT_ENCTYPE_DES_CFB64
#  endif
#  if !defined ENCTYPE_DES_OFB64 && defined TELOPT_ENCTYPE_DES_OFB64
#   define ENCTYPE_DES_OFB64 TELOPT_ENCTYPE_DES_OFB64
#  endif
#  if !defined ENCTYPE_CNT && defined TELOPT_ENCTYPE_CNT
#   define ENCTYPE_CNT TELOPT_ENCTYPE_CNT
#  endif

/*
 * Our capabilities are restricted to the encryption types
 * DES_CFB64 and DES_OFB64.  The latter type is sometimes
 * missing in <arpa/telnet.h>.  On the other hand, the same
 * header file may indicate more encryption types than are
 * supported by the present code.
 */
#  ifndef ENCTYPE_DES_OFB64
#   define ENCTYPE_DES_OFB64	2	/* RFC 2953 */
#  endif
#  undef ENCTYPE_CNT
#  define ENCTYPE_CNT	3	/* Up to DES_OFB64.  */

#  undef ENCTYPE_NAME_OK
#  define ENCTYPE_NAME_OK(x)	((unsigned int)(x) < ENCTYPE_CNT)

typedef unsigned char Block[8];
typedef unsigned char *BlockT;

#  ifndef HAVE_ARPA_TELNET_H_SCHEDULE
typedef struct
{
  Block _;
} Schedule[16];
#  endif
       /* !HAVE_ARPA_TELNET_H_SCHEDULE */

#  ifndef VALIDKEY
#   define VALIDKEY(key)	( key[0] | key[1] | key[2] | key[3] | \
				  key[4] | key[5] | key[6] | key[7])
#  endif

#  define SAMEKEY(k1, k2)	(!memcmp ((void *) k1, (void *) k2, sizeof (Block)))

#  ifndef HAVE_ARPA_TELNET_H_SESSION_KEY
typedef struct
{
  short type;
  int length;
  const unsigned char *data;
} Session_Key;
#  endif
       /* !HAVE_ARPA_TELNET_H_SESSION_KEY */

typedef struct
{
  char *name;
  int type;
  void (*output) (unsigned char *, int);
  int (*input) (int);
  void (*init) (int);
  int (*start) (int, int);
  int (*is) (unsigned char *, int);
  int (*reply) (unsigned char *, int);
  void (*session) (Session_Key *, int);
  int (*keyid) (int, unsigned char *, int *);
  void (*printsub) (unsigned char *, int, char *, int);
} Encryptions;

#  define SK_DES		1
				/* Matched Kerberos v5 KEYTYPE_DES */
#  define SK_OTHER	2	/* Non-DES key. */

#  include "enc-proto.h"

extern int encrypt_debug_mode;
extern int (*decrypt_input) (int);
extern void (*encrypt_output) (unsigned char *, int);
# endif/* __ENCRYPTION__ */
#endif /* ENCRYPTION */
