libssh  0.7.3
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 "libssh/priv.h"
24 #include "libssh/kex.h"
25 #include "libssh/packet.h"
26 #include "libssh/pcap.h"
27 #include "libssh/auth.h"
28 #include "libssh/channels.h"
29 #include "libssh/poll.h"
30 
31 /* These are the different states a SSH session can be into its life */
32 enum ssh_session_state_e {
33  SSH_SESSION_STATE_NONE=0,
34  SSH_SESSION_STATE_CONNECTING,
35  SSH_SESSION_STATE_SOCKET_CONNECTED,
36  SSH_SESSION_STATE_BANNER_RECEIVED,
37  SSH_SESSION_STATE_INITIAL_KEX,
38  SSH_SESSION_STATE_KEXINIT_RECEIVED,
39  SSH_SESSION_STATE_DH,
40  SSH_SESSION_STATE_AUTHENTICATING,
41  SSH_SESSION_STATE_AUTHENTICATED,
42  SSH_SESSION_STATE_ERROR,
43  SSH_SESSION_STATE_DISCONNECTED
44 };
45 
46 enum ssh_dh_state_e {
47  DH_STATE_INIT=0,
48  DH_STATE_INIT_SENT,
49  DH_STATE_NEWKEYS_SENT,
50  DH_STATE_FINISHED
51 };
52 
53 enum ssh_pending_call_e {
54  SSH_PENDING_CALL_NONE = 0,
55  SSH_PENDING_CALL_CONNECT,
56  SSH_PENDING_CALL_AUTH_NONE,
57  SSH_PENDING_CALL_AUTH_PASSWORD,
58  SSH_PENDING_CALL_AUTH_OFFER_PUBKEY,
59  SSH_PENDING_CALL_AUTH_PUBKEY,
60  SSH_PENDING_CALL_AUTH_AGENT,
61  SSH_PENDING_CALL_AUTH_KBDINT_INIT,
62  SSH_PENDING_CALL_AUTH_KBDINT_SEND,
63  SSH_PENDING_CALL_AUTH_GSSAPI_MIC
64 };
65 
66 /* libssh calls may block an undefined amount of time */
67 #define SSH_SESSION_FLAG_BLOCKING 1
68 
69 /* Client successfully authenticated */
70 #define SSH_SESSION_FLAG_AUTHENTICATED 2
71 
72 /* codes to use with ssh_handle_packets*() */
73 /* Infinite timeout */
74 #define SSH_TIMEOUT_INFINITE -1
75 /* Use the timeout defined by user if any. Mostly used with new connections */
76 #define SSH_TIMEOUT_USER -2
77 /* Use the default timeout, depending on ssh_is_blocking() */
78 #define SSH_TIMEOUT_DEFAULT -3
79 /* Don't block at all */
80 #define SSH_TIMEOUT_NONBLOCKING 0
81 
82 /* members that are common to ssh_session and ssh_bind */
83 struct ssh_common_struct {
84  struct error_struct error;
85  ssh_callbacks callbacks; /* Callbacks to user functions */
86  int log_verbosity; /* verbosity of the log functions */
87 };
88 
89 struct ssh_session_struct {
90  struct ssh_common_struct common;
91  struct ssh_socket_struct *socket;
92  char *serverbanner;
93  char *clientbanner;
94  int protoversion;
95  int server;
96  int client;
97  int openssh;
98  uint32_t send_seq;
99  uint32_t recv_seq;
100 
101  int connected;
102  /* !=0 when the user got a session handle */
103  int alive;
104  /* two previous are deprecated */
105  /* int auth_service_asked; */
106 
107  /* session flags (SSH_SESSION_FLAG_*) */
108  int flags;
109 
110  ssh_string banner; /* that's the issue banner from
111  the server */
112  char *discon_msg; /* disconnect message from
113  the remote host */
114  ssh_buffer in_buffer;
115  PACKET in_packet;
116  ssh_buffer out_buffer;
117 
118  /* the states are used by the nonblocking stuff to remember */
119  /* where it was before being interrupted */
120  enum ssh_pending_call_e pending_call_state;
121  enum ssh_session_state_e session_state;
122  int packet_state;
123  enum ssh_dh_state_e dh_handshake_state;
124  enum ssh_auth_service_state_e auth_service_state;
125  enum ssh_auth_state_e auth_state;
126  enum ssh_channel_request_state_e global_req_state;
127  struct ssh_agent_state_struct *agent_state;
128  struct ssh_auth_auto_state_struct *auth_auto_state;
129 
130  /*
131  * RFC 4253, 7.1: if the first_kex_packet_follows flag was set in
132  * the received SSH_MSG_KEXINIT, but the guess was wrong, this
133  * field will be set such that the following guessed packet will
134  * be ignored. Once that packet has been received and ignored,
135  * this field is cleared.
136  */
137  int first_kex_follows_guess_wrong;
138 
139  ssh_buffer in_hashbuf;
140  ssh_buffer out_hashbuf;
141  struct ssh_crypto_struct *current_crypto;
142  struct ssh_crypto_struct *next_crypto; /* next_crypto is going to be used after a SSH2_MSG_NEWKEYS */
143 
144  struct ssh_list *channels; /* linked list of channels */
145  int maxchannel;
146  int exec_channel_opened; /* version 1 only. more
147  info in channels1.c */
148  ssh_agent agent; /* ssh agent */
149 
150 /* keyb interactive data */
151  struct ssh_kbdint_struct *kbdint;
152  struct ssh_gssapi_struct *gssapi;
153  int version; /* 1 or 2 */
154  /* server host keys */
155  struct {
156  ssh_key rsa_key;
157  ssh_key dsa_key;
158  ssh_key ecdsa_key;
159  ssh_key ed25519_key;
160  /* The type of host key wanted by client */
161  enum ssh_keytypes_e hostkey;
162  } srv;
163  /* auths accepted by server */
164  int auth_methods;
165  struct ssh_list *ssh_message_list; /* list of delayed SSH messages */
166  int (*ssh_message_callback)( struct ssh_session_struct *session, ssh_message msg, void *userdata);
167  void *ssh_message_callback_data;
168  ssh_server_callbacks server_callbacks;
169  void (*ssh_connection_callback)( struct ssh_session_struct *session);
170  struct ssh_packet_callbacks_struct default_packet_callbacks;
171  struct ssh_list *packet_callbacks;
172  struct ssh_socket_callbacks_struct socket_callbacks;
173  ssh_poll_ctx default_poll_ctx;
174  /* options */
175 #ifdef WITH_PCAP
176  ssh_pcap_context pcap_ctx; /* pcap debugging context */
177 #endif
178  struct {
179  struct ssh_list *identity;
180  char *username;
181  char *host;
182  char *bindaddr; /* bind the client to an ip addr */
183  char *sshdir;
184  char *knownhosts;
185  char *wanted_methods[10];
186  char *ProxyCommand;
187  char *custombanner;
188  unsigned long timeout; /* seconds */
189  unsigned long timeout_usec;
190  unsigned int port;
191  socket_t fd;
192  int StrictHostKeyChecking;
193  int ssh2;
194  int ssh1;
195  char compressionlevel;
196  char *gss_server_identity;
197  char *gss_client_identity;
198  int gss_delegate_creds;
199  } opts;
200  /* counters */
201  ssh_counter socket_counter;
202  ssh_counter raw_counter;
203 };
204 
210 typedef int (*ssh_termination_function)(void *user);
211 int ssh_handle_packets(ssh_session session, int timeout);
212 int ssh_handle_packets_termination(ssh_session session, int timeout,
213  ssh_termination_function fct, void *user);
214 void ssh_socket_exception_callback(int code, int errno_code, void *user);
215 
216 #endif /* SESSION_H_ */
These are the callbacks exported by the socket structure They are called by the socket module when a ...
Definition: callbacks.h:363