libssh 0.9.5 The SSH library

session.h
1/*
2 * This file is part of the SSH Library
3 *
4 * Copyright (c) 2009 by Aris Adamantiadis
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#ifndef SESSION_H_
22#define SESSION_H_
23#include <stdbool.h>
24
25#include "libssh/priv.h"
26#include "libssh/kex.h"
27#include "libssh/packet.h"
28#include "libssh/pcap.h"
29#include "libssh/auth.h"
30#include "libssh/channels.h"
31#include "libssh/poll.h"
32#include "libssh/config.h"
33#include "libssh/misc.h"
34
35/* These are the different states a SSH session can be into its life */
36 enum ssh_session_state_e {
37 SSH_SESSION_STATE_NONE=0,
38 SSH_SESSION_STATE_CONNECTING,
39 SSH_SESSION_STATE_SOCKET_CONNECTED,
40 SSH_SESSION_STATE_BANNER_RECEIVED,
41 SSH_SESSION_STATE_INITIAL_KEX,
42 SSH_SESSION_STATE_KEXINIT_RECEIVED,
43 SSH_SESSION_STATE_DH,
44 SSH_SESSION_STATE_AUTHENTICATING,
45 SSH_SESSION_STATE_AUTHENTICATED,
46 SSH_SESSION_STATE_ERROR,
47 SSH_SESSION_STATE_DISCONNECTED
48};
49
50 enum ssh_dh_state_e {
51 DH_STATE_INIT=0,
52 DH_STATE_GROUP_SENT,
53 DH_STATE_REQUEST_SENT,
54 DH_STATE_INIT_SENT,
55 DH_STATE_NEWKEYS_SENT,
56 DH_STATE_FINISHED
57};
58
59 enum ssh_pending_call_e {
60 SSH_PENDING_CALL_NONE = 0,
61 SSH_PENDING_CALL_CONNECT,
62 SSH_PENDING_CALL_AUTH_NONE,
63 SSH_PENDING_CALL_AUTH_PASSWORD,
64 SSH_PENDING_CALL_AUTH_OFFER_PUBKEY,
65 SSH_PENDING_CALL_AUTH_PUBKEY,
66 SSH_PENDING_CALL_AUTH_AGENT,
67 SSH_PENDING_CALL_AUTH_KBDINT_INIT,
68 SSH_PENDING_CALL_AUTH_KBDINT_SEND,
69 SSH_PENDING_CALL_AUTH_GSSAPI_MIC
70};
71
72/* libssh calls may block an undefined amount of time */
73#define SSH_SESSION_FLAG_BLOCKING 1
74
75/* Client successfully authenticated */
76#define SSH_SESSION_FLAG_AUTHENTICATED 2
77
78/* codes to use with ssh_handle_packets*() */
79/* Infinite timeout */
80#define SSH_TIMEOUT_INFINITE -1
81/* Use the timeout defined by user if any. Mostly used with new connections */
82#define SSH_TIMEOUT_USER -2
83/* Use the default timeout, depending on ssh_is_blocking() */
84#define SSH_TIMEOUT_DEFAULT -3
85/* Don't block at all */
86#define SSH_TIMEOUT_NONBLOCKING 0
87
88/* options flags */
89/* Authentication with *** allowed */
90#define SSH_OPT_FLAG_PASSWORD_AUTH 0x1
91#define SSH_OPT_FLAG_PUBKEY_AUTH 0x2
92#define SSH_OPT_FLAG_KBDINT_AUTH 0x4
93#define SSH_OPT_FLAG_GSSAPI_AUTH 0x8
94
95/* extensions flags */
96/* negotiation enabled */
97#define SSH_EXT_NEGOTIATION 0x01
98/* server-sig-algs extension */
99#define SSH_EXT_SIG_RSA_SHA256 0x02
100#define SSH_EXT_SIG_RSA_SHA512 0x04
101
102/* members that are common to ssh_session and ssh_bind */
103 struct ssh_common_struct {
104 struct error_struct error;
105 ssh_callbacks callbacks; /* Callbacks to user functions */
106 int log_verbosity; /* verbosity of the log functions */
107};
108
109 struct ssh_session_struct {
110 struct ssh_common_struct common;
111 struct ssh_socket_struct *socket;
112 char *serverbanner;
113 char *clientbanner;
114 int protoversion;
115 int server;
116 int client;
117 int openssh;
118 uint32_t send_seq;
119 uint32_t recv_seq;
120 struct ssh_timestamp last_rekey_time;
121
122 int connected;
123 /* !=0 when the user got a session handle */
124 int alive;
125 /* two previous are deprecated */
126 /* int auth_service_asked; */
127
128 /* session flags (SSH_SESSION_FLAG_*) */
129 int flags;
130
131 /* Extensions negotiated using RFC 8308 */
132 uint32_t extensions;
133
134 ssh_string banner; /* that's the issue banner from
135 the server */
136 char *discon_msg; /* disconnect message from
137 the remote host */
138 ssh_buffer in_buffer;
139 PACKET in_packet;
140 ssh_buffer out_buffer;
141 struct ssh_list *out_queue; /* This list is used for delaying packets
142 when rekeying is required */
143
144 /* the states are used by the nonblocking stuff to remember */
145 /* where it was before being interrupted */
146 enum ssh_pending_call_e pending_call_state;
147 enum ssh_session_state_e session_state;
148 enum ssh_packet_state_e packet_state;
149 enum ssh_dh_state_e dh_handshake_state;
150 enum ssh_channel_request_state_e global_req_state;
151 struct ssh_agent_state_struct *agent_state;
152
153 struct {
154 struct ssh_auth_auto_state_struct *auto_state;
155 enum ssh_auth_service_state_e service_state;
156 enum ssh_auth_state_e state;
157 uint32_t supported_methods;
158 uint32_t current_method;
159 } auth;
160
161 /*
162 * RFC 4253, 7.1: if the first_kex_packet_follows flag was set in
163 * the received SSH_MSG_KEXINIT, but the guess was wrong, this
164 * field will be set such that the following guessed packet will
165 * be ignored. Once that packet has been received and ignored,
166 * this field is cleared.
167 */
168 int first_kex_follows_guess_wrong;
169
170 ssh_buffer in_hashbuf;
171 ssh_buffer out_hashbuf;
172 struct ssh_crypto_struct *current_crypto;
173 struct ssh_crypto_struct *next_crypto; /* next_crypto is going to be used after a SSH2_MSG_NEWKEYS */
174
175 struct ssh_list *channels; /* linked list of channels */
176 int maxchannel;
177 ssh_agent agent; /* ssh agent */
178
179/* keyb interactive data */
180 struct ssh_kbdint_struct *kbdint;
181 struct ssh_gssapi_struct *gssapi;
182
183 /* server host keys */
184 struct {
185 ssh_key rsa_key;
186 ssh_key dsa_key;
187 ssh_key ecdsa_key;
188 ssh_key ed25519_key;
189 /* The type of host key wanted by client */
190 enum ssh_keytypes_e hostkey;
191 enum ssh_digest_e hostkey_digest;
192 } srv;
193
194 /* auths accepted by server */
195 struct ssh_list *ssh_message_list; /* list of delayed SSH messages */
196 int (*ssh_message_callback)( struct ssh_session_struct *session, ssh_message msg, void *userdata);
197 void *ssh_message_callback_data;
198 ssh_server_callbacks server_callbacks;
199 void (*ssh_connection_callback)( struct ssh_session_struct *session);
200 struct ssh_packet_callbacks_struct default_packet_callbacks;
201 struct ssh_list *packet_callbacks;
202 struct ssh_socket_callbacks_struct socket_callbacks;
203 ssh_poll_ctx default_poll_ctx;
204 /* options */
205#ifdef WITH_PCAP
206 ssh_pcap_context pcap_ctx; /* pcap debugging context */
207#endif
208 struct {
209 struct ssh_list *identity;
210 char *username;
211 char *host;
212 char *bindaddr; /* bind the client to an ip addr */
213 char *sshdir;
214 char *knownhosts;
215 char *global_knownhosts;
216 char *wanted_methods[SSH_KEX_METHODS];
217 char *pubkey_accepted_types;
218 char *ProxyCommand;
219 char *custombanner;
220 unsigned long timeout; /* seconds */
221 unsigned long timeout_usec;
222 unsigned int port;
223 socket_t fd;
224 int StrictHostKeyChecking;
225 char compressionlevel;
226 char *gss_server_identity;
227 char *gss_client_identity;
228 int gss_delegate_creds;
229 int flags;
230 int nodelay;
231 bool config_processed;
232 uint8_t options_seen[SOC_MAX];
233 uint64_t rekey_data;
234 uint32_t rekey_time;
235 } opts;
236 /* counters */
237 ssh_counter socket_counter;
238 ssh_counter raw_counter;
239};
240
246 typedef int (*ssh_termination_function)(void *user);
247 int ssh_handle_packets(ssh_session session, int timeout);
248 int ssh_handle_packets_termination(ssh_session session,
249 long timeout,
250 ssh_termination_function fct,
251 void *user);
252 void ssh_socket_exception_callback(int code, int errno_code, void *user);
253
254#endif /* SESSION_H_ */
error_struct
Definition: priv.h:254
packet_struct
Definition: packet.h:29
ssh_agent_state_struct
Definition: auth.c:833
ssh_agent_struct
Definition: agent.h:73
ssh_auth_auto_state_struct
Definition: auth.c:971
ssh_buffer_struct
Definition: buffer.c:47
ssh_callbacks_struct
Definition: callbacks.h:142
ssh_common_struct
Definition: session.h:103
ssh_counter_struct
Definition: libssh.h:93
ssh_crypto_struct
Definition: crypto.h:106
ssh_gssapi_struct
Definition: gssapi.c:48
ssh_kbdint_struct
Definition: auth.h:37
ssh_key_struct
Definition: pki.h:50
ssh_list
Definition: misc.h:39
ssh_message_struct
Definition: messages.h:84
ssh_packet_callbacks_struct
Definition: callbacks.h:530
ssh_poll_ctx_struct
Definition: poll.c:76
ssh_server_callbacks_struct
Definition: callbacks.h:304
ssh_session_struct
Definition: session.h:109
ssh_socket_callbacks_struct
Definition: callbacks.h:378
ssh_socket_struct
Definition: socket.c:78
ssh_string_struct
Definition: string.h:29
ssh_timestamp
Definition: misc.h:49