/* $OpenBSD: ssh2.h,v 1.22 2023/10/10 03:57:45 djm Exp $ */

/*
 * Copyright (c) 2000 Markus Friedl.  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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/*
 * RFC4251:
 *
 *   Transport layer protocol:
 *
 *     1-19     Transport layer generic (e.g. disconnect, ignore, debug,
 *              etc)
 *     20-29    Algorithm negotiation
 *     30-49    Key exchange method specific (numbers can be reused for
 *              different authentication methods)
 *
 *   User authentication protocol:
 *
 *     50-59    User authentication generic
 *     60-79    User authentication method specific (numbers can be reused
 *              for different authentication methods)
 *
 *   Connection protocol:
 *
 *     80-89    Connection protocol generic
 *     90-127   Channel related messages
 *
 *   Reserved for client protocols:
 *
 *     128-191  Reserved
 *
 *   Local extensions:
 *
 *     192-255  Local extensions
 *     248-255  Local extensions (OpenSSH will never use numbers in this range)
 */

/* special marker for no message */

#define SSH_MSG_NONE                                    0

/* ranges */

#define SSH2_MSG_TRANSPORT_MIN                          1
#define SSH2_MSG_TRANSPORT_MAX                          49
#define SSH2_MSG_USERAUTH_MIN                           50
#define SSH2_MSG_USERAUTH_MAX                           79
#define SSH2_MSG_USERAUTH_PER_METHOD_MIN                60
#define SSH2_MSG_USERAUTH_PER_METHOD_MAX                SSH2_MSG_USERAUTH_MAX
#define SSH2_MSG_CONNECTION_MIN                         80
#define SSH2_MSG_CONNECTION_MAX                         127
#define SSH2_MSG_RESERVED_MIN                           128
#define SSH2_MSG_RESERVED_MAX                           191
#define SSH2_MSG_LOCAL_MIN                              192
#define SSH2_MSG_LOCAL_MAX                              255
#define SSH2_MSG_MIN                                    1
#define SSH2_MSG_MAX                                    255

/* transport layer: generic */

#define SSH2_MSG_DISCONNECT                             1
#define SSH2_MSG_IGNORE                                 2
#define SSH2_MSG_UNIMPLEMENTED                          3
#define SSH2_MSG_DEBUG                                  4
#define SSH2_MSG_SERVICE_REQUEST                        5
#define SSH2_MSG_SERVICE_ACCEPT                         6
#define SSH2_MSG_EXT_INFO                               7
#define SSH2_MSG_NEWCOMPRESS                            8

/* transport layer: alg negotiation */

#define SSH2_MSG_KEXINIT                                20
#define SSH2_MSG_NEWKEYS                                21

/* transport layer: kex specific messages, can be reused */

#define SSH2_MSG_KEXDH_INIT                             30
#define SSH2_MSG_KEXDH_REPLY                            31

/* dh-group-exchange */
#define SSH2_MSG_KEX_DH_GEX_REQUEST_OLD                 30
#define SSH2_MSG_KEX_DH_GEX_GROUP                       31
#define SSH2_MSG_KEX_DH_GEX_INIT                        32
#define SSH2_MSG_KEX_DH_GEX_REPLY                       33
#define SSH2_MSG_KEX_DH_GEX_REQUEST                     34

/* ecdh */
#define SSH2_MSG_KEX_ECDH_INIT                          30
#define SSH2_MSG_KEX_ECDH_REPLY                         31

/* transport layer: OpenSSH extensions */
#define SSH2_MSG_PING                                   192
#define SSH2_MSG_PONG                                   193

/* user authentication: generic */

#define SSH2_MSG_USERAUTH_REQUEST                       50
#define SSH2_MSG_USERAUTH_FAILURE                       51
#define SSH2_MSG_USERAUTH_SUCCESS                       52
#define SSH2_MSG_USERAUTH_BANNER                        53

/* user authentication: method specific, can be reused */

#define SSH2_MSG_USERAUTH_PK_OK                         60
#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ              60
#define SSH2_MSG_USERAUTH_INFO_REQUEST                  60
#define SSH2_MSG_USERAUTH_INFO_RESPONSE                 61

/* connection protocol: generic */

#define SSH2_MSG_GLOBAL_REQUEST                         80
#define SSH2_MSG_REQUEST_SUCCESS                        81
#define SSH2_MSG_REQUEST_FAILURE                        82

/* channel related messages */

#define SSH2_MSG_CHANNEL_OPEN                           90
#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION              91
#define SSH2_MSG_CHANNEL_OPEN_FAILURE                   92
#define SSH2_MSG_CHANNEL_WINDOW_ADJUST                  93
#define SSH2_MSG_CHANNEL_DATA                           94
#define SSH2_MSG_CHANNEL_EXTENDED_DATA                  95
#define SSH2_MSG_CHANNEL_EOF                            96
#define SSH2_MSG_CHANNEL_CLOSE                          97
#define SSH2_MSG_CHANNEL_REQUEST                        98
#define SSH2_MSG_CHANNEL_SUCCESS                        99
#define SSH2_MSG_CHANNEL_FAILURE                        100

/* disconnect reason code */

#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT     1
#define SSH2_DISCONNECT_PROTOCOL_ERROR                  2
#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED             3
#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED      4
#define SSH2_DISCONNECT_RESERVED                        4
#define SSH2_DISCONNECT_MAC_ERROR                       5
#define SSH2_DISCONNECT_COMPRESSION_ERROR               6
#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE           7
#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED  8
#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE         9
#define SSH2_DISCONNECT_CONNECTION_LOST                 10
#define SSH2_DISCONNECT_BY_APPLICATION                  11
#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS            12
#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER          13
#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE  14
#define SSH2_DISCONNECT_ILLEGAL_USER_NAME               15

/* misc */

#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED           1
#define SSH2_OPEN_CONNECT_FAILED                        2
#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE                  3
#define SSH2_OPEN_RESOURCE_SHORTAGE                     4

#define SSH2_EXTENDED_DATA_STDERR                       1

/* Certificate types for OpenSSH certificate keys extension */
#define SSH2_CERT_TYPE_USER                             1
#define SSH2_CERT_TYPE_HOST                             2