libssh: session.h Source File

libssh 0.10.3 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/callbacks.h"
27#include "libssh/kex.h"
28#include "libssh/packet.h"
29#include "libssh/pcap.h"
30#include "libssh/auth.h"
31#include "libssh/channels.h"
32#include "libssh/poll.h"
33#include "libssh/config.h"
34#include "libssh/misc.h"
35
36/* These are the different states a SSH session can be into its life */
37enum ssh_session_state_e {
38 SSH_SESSION_STATE_NONE=0,
39 SSH_SESSION_STATE_CONNECTING,
40 SSH_SESSION_STATE_SOCKET_CONNECTED,
41 SSH_SESSION_STATE_BANNER_RECEIVED,
42 SSH_SESSION_STATE_INITIAL_KEX,
43 SSH_SESSION_STATE_KEXINIT_RECEIVED,
44 SSH_SESSION_STATE_DH,
45 SSH_SESSION_STATE_AUTHENTICATING,
46 SSH_SESSION_STATE_AUTHENTICATED,
47 SSH_SESSION_STATE_ERROR,
48 SSH_SESSION_STATE_DISCONNECTED
49};
50
51enum ssh_dh_state_e {
52 DH_STATE_INIT=0,
53 DH_STATE_GROUP_SENT,
54 DH_STATE_REQUEST_SENT,
55 DH_STATE_INIT_SENT,
56 DH_STATE_NEWKEYS_SENT,
57 DH_STATE_FINISHED
58};
59
60enum ssh_pending_call_e {
61 SSH_PENDING_CALL_NONE = 0,
62 SSH_PENDING_CALL_CONNECT,
63 SSH_PENDING_CALL_AUTH_NONE,
64 SSH_PENDING_CALL_AUTH_PASSWORD,
65 SSH_PENDING_CALL_AUTH_OFFER_PUBKEY,
66 SSH_PENDING_CALL_AUTH_PUBKEY,
67 SSH_PENDING_CALL_AUTH_AGENT,
68 SSH_PENDING_CALL_AUTH_KBDINT_INIT,
69 SSH_PENDING_CALL_AUTH_KBDINT_SEND,
70 SSH_PENDING_CALL_AUTH_GSSAPI_MIC
71};
72
73/* libssh calls may block an undefined amount of time */
74#define SSH_SESSION_FLAG_BLOCKING 1
75
76/* Client successfully authenticated */
77#define SSH_SESSION_FLAG_AUTHENTICATED 2
78
79/* codes to use with ssh_handle_packets*() */
80/* Infinite timeout */
81#define SSH_TIMEOUT_INFINITE -1
82/* Use the timeout defined by user if any. Mostly used with new connections */
83#define SSH_TIMEOUT_USER -2
84/* Use the default timeout, depending on ssh_is_blocking() */
85#define SSH_TIMEOUT_DEFAULT -3
86/* Don't block at all */
87#define SSH_TIMEOUT_NONBLOCKING 0
88
89/* options flags */
90/* Authentication with *** allowed */
91#define SSH_OPT_FLAG_PASSWORD_AUTH 0x1
92#define SSH_OPT_FLAG_PUBKEY_AUTH 0x2
93#define SSH_OPT_FLAG_KBDINT_AUTH 0x4
94#define SSH_OPT_FLAG_GSSAPI_AUTH 0x8
95
96/* extensions flags */
97/* negotiation enabled */
98#define SSH_EXT_NEGOTIATION 0x01
99/* server-sig-algs extension */
100#define SSH_EXT_SIG_RSA_SHA256 0x02
101#define SSH_EXT_SIG_RSA_SHA512 0x04
102
103/* members that are common to ssh_session and ssh_bind */
104 struct ssh_common_struct {
105 struct error_struct error;
106 ssh_callbacks callbacks; /* Callbacks to user functions */
107 int log_verbosity; /* verbosity of the log functions */
108};
109
110 struct ssh_session_struct {
111 struct ssh_common_struct common;
112 struct ssh_socket_struct *socket;
113 char *serverbanner;
114 char *clientbanner;
115 int protoversion;
116 int server;
117 int client;
118 int openssh;
119 uint32_t send_seq;
120 uint32_t recv_seq;
121 struct ssh_timestamp last_rekey_time;
122
123 int connected;
124 /* !=0 when the user got a session handle */
125 int alive;
126 /* two previous are deprecated */
127 /* int auth_service_asked; */
128
129 /* session flags (SSH_SESSION_FLAG_*) */
130 int flags;
131
132 /* Extensions negotiated using RFC 8308 */
133 uint32_t extensions;
134
135 ssh_string banner; /* that's the issue banner from
136 the server */
137 char *discon_msg; /* disconnect message from
138 the remote host */
139 char *disconnect_message; /* disconnect message to be set */
140 ssh_buffer in_buffer;
141 PACKET in_packet;
142 ssh_buffer out_buffer;
143 struct ssh_list *out_queue; /* This list is used for delaying packets
144 when rekeying is required */
145
146 /* the states are used by the nonblocking stuff to remember */
147 /* where it was before being interrupted */
148 enum ssh_pending_call_e pending_call_state;
149 enum ssh_session_state_e session_state;
150 enum ssh_packet_state_e packet_state;
151 enum ssh_dh_state_e dh_handshake_state;
152 enum ssh_channel_request_state_e global_req_state;
153 struct ssh_agent_state_struct *agent_state;
154
155 struct {
156 struct ssh_auth_auto_state_struct *auto_state;
157 enum ssh_auth_service_state_e service_state;
158 enum ssh_auth_state_e state;
159 uint32_t supported_methods;
160 uint32_t current_method;
161 } auth;
162
163 /*
164 * RFC 4253, 7.1: if the first_kex_packet_follows flag was set in
165 * the received SSH_MSG_KEXINIT, but the guess was wrong, this
166 * field will be set such that the following guessed packet will
167 * be ignored. Once that packet has been received and ignored,
168 * this field is cleared.
169 */
170 int first_kex_follows_guess_wrong;
171
172 ssh_buffer in_hashbuf;
173 ssh_buffer out_hashbuf;
174 struct ssh_crypto_struct *current_crypto;
175 struct ssh_crypto_struct *next_crypto; /* next_crypto is going to be used after a SSH2_MSG_NEWKEYS */
176
177 struct ssh_list *channels; /* linked list of channels */
178 uint32_t maxchannel;
179 ssh_agent agent; /* ssh agent */
180
181/* keyb interactive data */
182 struct ssh_kbdint_struct *kbdint;
183 struct ssh_gssapi_struct *gssapi;
184
185 /* server host keys */
186 struct {
187 ssh_key rsa_key;
188 ssh_key dsa_key;
189 ssh_key ecdsa_key;
190 ssh_key ed25519_key;
191 /* The type of host key wanted by client */
192 enum ssh_keytypes_e hostkey;
193 enum ssh_digest_e hostkey_digest;
194 } srv;
195
196 /* auths accepted by server */
197 struct ssh_list *ssh_message_list; /* list of delayed SSH messages */
198 int (*ssh_message_callback)( struct ssh_session_struct *session, ssh_message msg, void *userdata);
199 void *ssh_message_callback_data;
200 ssh_server_callbacks server_callbacks;
201 void (*ssh_connection_callback)( struct ssh_session_struct *session);
202 struct ssh_packet_callbacks_struct default_packet_callbacks;
203 struct ssh_list *packet_callbacks;
204 struct ssh_socket_callbacks_struct socket_callbacks;
205 ssh_poll_ctx default_poll_ctx;
206 /* options */
207#ifdef WITH_PCAP
208 ssh_pcap_context pcap_ctx; /* pcap debugging context */
209#endif
210 struct {
211 struct ssh_list *identity;
212 char *username;
213 char *host;
214 char *bindaddr; /* bind the client to an ip addr */
215 char *sshdir;
216 char *knownhosts;
217 char *global_knownhosts;
218 char *wanted_methods[SSH_KEX_METHODS];
219 char *pubkey_accepted_types;
220 char *ProxyCommand;
221 char *custombanner;
222 char *moduli_file;
223 char *agent_socket;
224 unsigned long timeout; /* seconds */
225 unsigned long timeout_usec;
226 uint16_t port;
227 socket_t fd;
228 int StrictHostKeyChecking;
229 char compressionlevel;
230 char *gss_server_identity;
231 char *gss_client_identity;
232 int gss_delegate_creds;
233 int flags;
234 int nodelay;
235 bool config_processed;
236 uint8_t options_seen[SOC_MAX];
237 uint64_t rekey_data;
238 uint32_t rekey_time;
239 int rsa_min_size;
240 } opts;
241 /* counters */
242 ssh_counter socket_counter;
243 ssh_counter raw_counter;
244};
245
251typedef int (*ssh_termination_function)(void *user);
252int ssh_handle_packets(ssh_session session, int timeout);
253int ssh_handle_packets_termination(ssh_session session,
254 int timeout,
255 ssh_termination_function fct,
256 void *user);
257void ssh_socket_exception_callback(int code, int errno_code, void *user);
258
259#endif /* SESSION_H_ */
error_struct
Definition: priv.h:259
packet_struct
Definition: packet.h:29
ssh_agent_state_struct
Definition: auth.c:864
ssh_agent_struct
Definition: agent.h:73
ssh_auth_auto_state_struct
Definition: auth.c:1003
ssh_buffer_struct
Definition: buffer.c:47
ssh_callbacks_struct
Definition: callbacks.h:142
ssh_common_struct
Definition: session.h:104
ssh_counter_struct
Definition: libssh.h:95
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:54
ssh_list
Definition: misc.h:39
ssh_message_struct
Definition: messages.h:85
ssh_packet_callbacks_struct
Definition: callbacks.h:533
ssh_poll_ctx_struct
Definition: poll.c:76
ssh_server_callbacks_struct
Definition: callbacks.h:304
ssh_session_struct
Definition: session.h:110
ssh_socket_callbacks_struct
Definition: callbacks.h:381
ssh_socket_struct
Definition: socket.c:87
ssh_string_struct
Definition: string.h:29
ssh_timestamp
Definition: misc.h:49