libssh
libsshpp.hpp
1 /*
2  * This file is part of the SSH Library
3  *
4  * Copyright (c) 2010 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 LIBSSHPP_HPP_
22 #define LIBSSHPP_HPP_
23 
51 /* do not use deprecated functions */
52 #define LIBSSH_LEGACY_0_4
53 
54 #include <libssh/libssh.h>
55 #include <libssh/server.h>
56 #include <stdlib.h>
57 #include <stdarg.h>
58 #include <stdio.h>
59 #include <string>
60 
61 namespace ssh {
62 
63 class Channel;
68 #ifndef SSH_NO_CPP_EXCEPTIONS
69 
75 public:
76  SshException(ssh_session csession){
77  code=ssh_get_error_code(csession);
78  description=std::string(ssh_get_error(csession));
79  }
80  SshException(const SshException &e){
81  code=e.code;
82  description=e.description;
83  }
89  int getCode(){
90  return code;
91  }
96  std::string getError(){
97  return description;
98  }
99 private:
100  int code;
101  std::string description;
102 };
103 
107 #define ssh_throw(x) if((x)==SSH_ERROR) throw SshException(getCSession())
108 #define ssh_throw_null(CSession,x) if((x)==NULL) throw SshException(CSession)
109 #define void_throwable void
110 #define return_throwable return
111 
112 #else
113 
114 /* No exception at all. All functions will return an error code instead
115  * of an exception
116  */
117 #define ssh_throw(x) if((x)==SSH_ERROR) return SSH_ERROR
118 #define ssh_throw_null(CSession,x) if((x)==NULL) return NULL
119 #define void_throwable int
120 #define return_throwable return SSH_OK
121 #endif
122 
126 class Session {
127  friend class Channel;
128 public:
129  Session(){
130  c_session=ssh_new();
131  }
132  ~Session(){
133  ssh_free(c_session);
134  c_session=NULL;
135  }
142  void_throwable setOption(enum ssh_options_e type, const char *option){
143  ssh_throw(ssh_options_set(c_session,type,option));
144  return_throwable;
145  }
152  void_throwable setOption(enum ssh_options_e type, long int option){
153  ssh_throw(ssh_options_set(c_session,type,&option));
154  return_throwable;
155  }
162  void_throwable setOption(enum ssh_options_e type, void *option){
163  ssh_throw(ssh_options_set(c_session,type,option));
164  return_throwable;
165  }
170  void_throwable connect(){
171  int ret=ssh_connect(c_session);
172  ssh_throw(ret);
173  return_throwable;
174  }
181  int ret=ssh_userauth_publickey_auto(c_session, NULL, NULL);
182  ssh_throw(ret);
183  return ret;
184  }
193  int ret=ssh_userauth_none(c_session,NULL);
194  ssh_throw(ret);
195  return ret;
196  }
197 
205  int userauthKbdint(const char* username, const char* submethods){
206  int ret=ssh_userauth_kbdint(c_session,NULL,NULL);
207  ssh_throw(ret);
208  return ret;
209  }
210 
216  return ssh_userauth_kbdint_getnprompts(c_session);
217  }
218 
226  int userauthKbdintSetAnswer(unsigned int i, const char* answer){
227  int ret=ssh_userauth_kbdint_setanswer(c_session, i, answer);
228  ssh_throw(ret);
229  return ret;
230  }
231 
232 
233 
240  int userauthPassword(const char *password){
241  int ret=ssh_userauth_password(c_session,NULL,password);
242  ssh_throw(ret);
243  return ret;
244  }
252  int userauthTryPublickey(ssh_key pubkey){
253  int ret=ssh_userauth_try_publickey(c_session, NULL, pubkey);
254  ssh_throw(ret);
255  return ret;
256  }
263  int userauthPublickey(ssh_key privkey){
264  int ret=ssh_userauth_publickey(c_session, NULL, privkey);
265  ssh_throw(ret);
266  return ret;
267  }
268 
274  int getAuthList(){
275  int ret=ssh_userauth_list(c_session, NULL);
276  ssh_throw(ret);
277  return ret;
278  }
282  void disconnect(){
283  ssh_disconnect(c_session);
284  }
289  const char *getDisconnectMessage(){
290  const char *msg=ssh_get_disconnect_message(c_session);
291  return msg;
292  }
296  const char *getError(){
297  return ssh_get_error(c_session);
298  }
302  int getErrorCode(){
303  return ssh_get_error_code(c_session);
304  }
311  socket_t getSocket(){
312  return ssh_get_fd(c_session);
313  }
318  std::string getIssueBanner(){
319  char *banner=ssh_get_issue_banner(c_session);
320  std::string ret;
321  if (banner)
322  {
323  ret= std::string(banner);
324  ::free(banner);
325  }
326  return ret;
327  }
333  return ssh_get_openssh_version(c_session);
334  }
339  int getVersion(){
340  return ssh_get_version(c_session);
341  }
349  int state = ssh_session_is_known_server(c_session);
350  ssh_throw(state);
351  return state;
352  }
353  void log(int priority, const char *format, ...){
354  char buffer[1024];
355  va_list va;
356 
357  va_start(va, format);
358  vsnprintf(buffer, sizeof(buffer), format, va);
359  va_end(va);
360  _ssh_log(priority, "libsshpp", "%s", buffer);
361  }
362 
367  void_throwable optionsCopy(const Session &source){
368  ssh_throw(ssh_options_copy(source.c_session,&c_session));
369  return_throwable;
370  }
376  void_throwable optionsParseConfig(const char *file){
377  ssh_throw(ssh_options_parse_config(c_session,file));
378  return_throwable;
379  }
384  ssh_silent_disconnect(c_session);
385  }
392  int ret = ssh_write_knownhost(c_session);
393  ssh_throw(ret);
394  return ret;
395  }
396 
405  inline Channel *acceptForward(int timeout_ms);
406  /* implemented outside the class due Channel references */
407 
408  void_throwable cancelForward(const char *address, int port){
409  int err=ssh_channel_cancel_forward(c_session, address, port);
410  ssh_throw(err);
411  return_throwable;
412  }
413 
414  void_throwable listenForward(const char *address, int port,
415  int &boundport){
416  int err=ssh_channel_listen_forward(c_session, address, port, &boundport);
417  ssh_throw(err);
418  return_throwable;
419  }
420 
421  ssh_session getCSession(){
422  return c_session;
423  }
424 
425 protected:
426  ssh_session c_session;
427 
428 private:
429  /* No copy constructor, no = operator */
430  Session(const Session &);
431  Session& operator=(const Session &);
432 };
433 
438 class Channel {
439  friend class Session;
440 public:
441  Channel(Session &session){
442  channel=ssh_channel_new(session.getCSession());
443  this->session=&session;
444  }
445  ~Channel(){
446  ssh_channel_free(channel);
447  channel=NULL;
448  }
449 
458  Channel *acceptX11(int timeout_ms){
459  ssh_channel x11chan = ssh_channel_accept_x11(channel,timeout_ms);
460  ssh_throw_null(getCSession(),x11chan);
461  Channel *newchan = new Channel(getSession(),x11chan);
462  return newchan;
463  }
470  void_throwable changePtySize(int cols, int rows){
471  int err=ssh_channel_change_pty_size(channel,cols,rows);
472  ssh_throw(err);
473  return_throwable;
474  }
475 
480  void_throwable close(){
481  ssh_throw(ssh_channel_close(channel));
482  return_throwable;
483  }
484 
485  int getExitStatus(){
486  return ssh_channel_get_exit_status(channel);
487  }
488  Session &getSession(){
489  return *session;
490  }
494  bool isClosed(){
495  return ssh_channel_is_closed(channel) != 0;
496  }
500  bool isEof(){
501  return ssh_channel_is_eof(channel) != 0;
502  }
506  bool isOpen(){
507  return ssh_channel_is_open(channel) != 0;
508  }
509  int openForward(const char *remotehost, int remoteport,
510  const char *sourcehost=NULL, int localport=0){
511  int err=ssh_channel_open_forward(channel,remotehost,remoteport,
512  sourcehost, localport);
513  ssh_throw(err);
514  return err;
515  }
516  /* TODO: completely remove this ? */
517  void_throwable openSession(){
518  int err=ssh_channel_open_session(channel);
519  ssh_throw(err);
520  return_throwable;
521  }
522  int poll(bool is_stderr=false){
523  int err=ssh_channel_poll(channel,is_stderr);
524  ssh_throw(err);
525  return err;
526  }
527  int read(void *dest, size_t count){
528  int err;
529  /* handle int overflow */
530  if(count > 0x7fffffff)
531  count = 0x7fffffff;
532  err=ssh_channel_read_timeout(channel,dest,count,false,-1);
533  ssh_throw(err);
534  return err;
535  }
536  int read(void *dest, size_t count, int timeout){
537  int err;
538  /* handle int overflow */
539  if(count > 0x7fffffff)
540  count = 0x7fffffff;
541  err=ssh_channel_read_timeout(channel,dest,count,false,timeout);
542  ssh_throw(err);
543  return err;
544  }
545  int read(void *dest, size_t count, bool is_stderr=false, int timeout=-1){
546  int err;
547  /* handle int overflow */
548  if(count > 0x7fffffff)
549  count = 0x7fffffff;
550  err=ssh_channel_read_timeout(channel,dest,count,is_stderr,timeout);
551  ssh_throw(err);
552  return err;
553  }
554  int readNonblocking(void *dest, size_t count, bool is_stderr=false){
555  int err;
556  /* handle int overflow */
557  if(count > 0x7fffffff)
558  count = 0x7fffffff;
559  err=ssh_channel_read_nonblocking(channel,dest,count,is_stderr);
560  ssh_throw(err);
561  return err;
562  }
563  void_throwable requestEnv(const char *name, const char *value){
564  int err=ssh_channel_request_env(channel,name,value);
565  ssh_throw(err);
566  return_throwable;
567  }
568 
569  void_throwable requestExec(const char *cmd){
570  int err=ssh_channel_request_exec(channel,cmd);
571  ssh_throw(err);
572  return_throwable;
573  }
574  void_throwable requestPty(const char *term=NULL, int cols=0, int rows=0){
575  int err;
576  if(term != NULL && cols != 0 && rows != 0)
577  err=ssh_channel_request_pty_size(channel,term,cols,rows);
578  else
579  err=ssh_channel_request_pty(channel);
580  ssh_throw(err);
581  return_throwable;
582  }
583 
584  void_throwable requestShell(){
585  int err=ssh_channel_request_shell(channel);
586  ssh_throw(err);
587  return_throwable;
588  }
589  void_throwable requestSendSignal(const char *signum){
590  int err=ssh_channel_request_send_signal(channel, signum);
591  ssh_throw(err);
592  return_throwable;
593  }
594  void_throwable requestSubsystem(const char *subsystem){
595  int err=ssh_channel_request_subsystem(channel,subsystem);
596  ssh_throw(err);
597  return_throwable;
598  }
599  int requestX11(bool single_connection,
600  const char *protocol, const char *cookie, int screen_number){
601  int err=ssh_channel_request_x11(channel,single_connection,
602  protocol, cookie, screen_number);
603  ssh_throw(err);
604  return err;
605  }
606  void_throwable sendEof(){
607  int err=ssh_channel_send_eof(channel);
608  ssh_throw(err);
609  return_throwable;
610  }
620  int write(const void *data, size_t len, bool is_stderr=false){
621  int ret;
622  if(is_stderr){
623  ret=ssh_channel_write_stderr(channel,data,len);
624  } else {
625  ret=ssh_channel_write(channel,data,len);
626  }
627  ssh_throw(ret);
628  return ret;
629  }
630 
631  ssh_session getCSession(){
632  return session->getCSession();
633  }
634 
635  ssh_channel getCChannel() {
636  return channel;
637  }
638 
639 protected:
640  Session *session;
641  ssh_channel channel;
642 
643 private:
644  Channel (Session &session, ssh_channel c_channel){
645  this->channel=c_channel;
646  this->session=&session;
647  }
648  /* No copy and no = operator */
649  Channel(const Channel &);
650  Channel &operator=(const Channel &);
651 };
652 
653 
654 inline Channel *Session::acceptForward(int timeout_ms){
655  ssh_channel forward =
656  ssh_channel_accept_forward(c_session, timeout_ms, NULL);
657  ssh_throw_null(c_session,forward);
658  Channel *newchan = new Channel(*this,forward);
659  return newchan;
660  }
661 
662 } // namespace ssh
663 
665 #endif /* LIBSSHPP_HPP_ */
int userauthNone()
Authenticates using the "none" method.
Definition: libsshpp.hpp:192
int userauthKbdintGetNPrompts()
Get the number of prompts (questions) the server has given.
Definition: libsshpp.hpp:215
int getAuthList()
Returns the available authentication methods from the server.
Definition: libsshpp.hpp:274
Definition: libsshpp.hpp:61
int ssh_userauth_kbdint(ssh_session session, const char *user, const char *submethods)
Try to authenticate through the "keyboard-interactive" method.
Definition: auth.c:1540
int ssh_channel_read_timeout(ssh_channel channel, void *dest, uint32_t count, int is_stderr, int timeout_ms)
Reads data from a channel.
Definition: channels.c:2681
void connect()
connects to the remote host
Definition: libsshpp.hpp:170
int ssh_options_parse_config(ssh_session session, const char *filename)
Parse the ssh config file.
Definition: options.c:1250
Channel * acceptX11(int timeout_ms)
accept an incoming X11 connection
Definition: libsshpp.hpp:458
int ssh_channel_request_x11(ssh_channel channel, int single_connection, const char *protocol, const char *cookie, int screen_number)
Sends the "x11-req" channel request over an existing session channel.
Definition: channels.c:1867
int ssh_channel_request_shell(ssh_channel channel)
Request a shell.
Definition: channels.c:1756
int ssh_channel_open_forward(ssh_channel channel, const char *remotehost, int remoteport, const char *sourcehost, int localport)
Open a TCP/IP forwarding channel.
Definition: channels.c:944
int ssh_channel_is_eof(ssh_channel channel)
Check if remote has sent an EOF.
Definition: channels.c:1433
int isServerKnown()
verifies that the server is known
Definition: libsshpp.hpp:348
int ssh_channel_send_eof(ssh_channel channel)
Send an end of file on the channel.
Definition: channels.c:1075
void close()
closes a channel
Definition: libsshpp.hpp:480
int ssh_channel_close(ssh_channel channel)
Close a channel.
Definition: channels.c:1127
int userauthPublickey(ssh_key privkey)
Authenticates using the publickey method.
Definition: libsshpp.hpp:263
int getVersion()
returns the version of the SSH protocol being used
Definition: libsshpp.hpp:339
The ssh::Session class contains the state of a SSH connection.
Definition: libsshpp.hpp:126
int ssh_get_openssh_version(ssh_session session)
Get the version of the OpenSSH server, if it is not an OpenSSH server then 0 will be returned...
Definition: client.c:629
int ssh_userauth_list(ssh_session session, const char *username)
Get available authentication methods from the server.
Definition: auth.c:332
const char * ssh_get_error(void *error)
Retrieve the error text message from the last error.
Definition: error.c:113
int ssh_channel_write(ssh_channel channel, const void *data, uint32_t len)
Blocking write on a channel.
Definition: channels.c:1390
int ssh_channel_request_pty_size(ssh_channel channel, const char *term, int cols, int rows)
Request a pty with a specific type and size.
Definition: channels.c:1635
int ssh_channel_request_subsystem(ssh_channel channel, const char *subsystem)
Request a subsystem (for example "sftp").
Definition: channels.c:1778
the ssh::Channel class describes the state of an SSH channel.
Definition: libsshpp.hpp:438
int ssh_get_version(ssh_session session)
Get the protocol version of the session.
Definition: session.c:797
int ssh_channel_request_env(ssh_channel channel, const char *name, const char *value)
Set environment variables.
Definition: channels.c:2320
int userauthKbdint(const char *username, const char *submethods)
Authenticate through the "keyboard-interactive" method.
Definition: libsshpp.hpp:205
int userauthPublickeyAuto(void)
Authenticates automatically using public key.
Definition: libsshpp.hpp:180
char * ssh_get_issue_banner(ssh_session session)
Get the issue banner from the server.
Definition: client.c:603
int write(const void *data, size_t len, bool is_stderr=false)
Writes on a channel.
Definition: libsshpp.hpp:620
void changePtySize(int cols, int rows)
change the size of a pseudoterminal
Definition: libsshpp.hpp:470
int ssh_userauth_kbdint_getnprompts(ssh_session session)
Get the number of prompts (questions) the server has given.
Definition: auth.c:1583
std::string getIssueBanner()
gets the Issue banner from the ssh server
Definition: libsshpp.hpp:318
int ssh_options_copy(ssh_session src, ssh_session *dest)
Duplicate the options of a session structure.
Definition: options.c:64
void disconnect()
Disconnects from the SSH server and closes connection.
Definition: libsshpp.hpp:282
int getCode()
returns the Error code
Definition: libsshpp.hpp:89
int ssh_channel_open_session(ssh_channel channel)
Open a session channel (suited for a shell, not TCP forwarding).
Definition: channels.c:879
Some people do not like C++ exceptions.
Definition: libsshpp.hpp:74
int ssh_channel_is_open(ssh_channel channel)
Check if the channel is open or not.
Definition: channels.c:1403
int ssh_write_knownhost(ssh_session session)
Write the current server as known in the known hosts file.
Definition: known_hosts.c:524
int ssh_channel_is_closed(ssh_channel channel)
Check if the channel is closed or not.
Definition: channels.c:1419
socket_t getSocket()
returns the file descriptor used for the communication
Definition: libsshpp.hpp:311
void optionsParseConfig(const char *file)
parses a configuration file for options
Definition: libsshpp.hpp:376
void setOption(enum ssh_options_e type, void *option)
sets an SSH session options
Definition: libsshpp.hpp:162
int ssh_channel_poll(ssh_channel channel, int is_stderr)
Polls a channel for data to read.
Definition: channels.c:2843
int writeKnownhost()
Writes the known host file with current host key.
Definition: libsshpp.hpp:391
ssh_channel ssh_channel_new(ssh_session session)
Allocate a new channel.
Definition: channels.c:79
int ssh_options_set(ssh_session session, enum ssh_options_e type, const void *value)
This function can set all possible ssh options.
Definition: options.c:417
int ssh_userauth_password(ssh_session session, const char *username, const char *password)
Try to authenticate by password.
Definition: auth.c:1130
int ssh_userauth_publickey_auto(ssh_session session, const char *username, const char *passphrase)
Tries to automatically authenticate with public key and "none".
Definition: auth.c:909
int ssh_userauth_kbdint_setanswer(ssh_session session, unsigned int i, const char *answer)
Set the answer for a question from a message block.
Definition: auth.c:1738
int ssh_userauth_publickey(ssh_session session, const char *username, const ssh_key privkey)
Authenticate with public/private key or certificate.
Definition: auth.c:547
socket_t ssh_get_fd(ssh_session session)
Get the fd of a connection.
Definition: session.c:530
int userauthPassword(const char *password)
Authenticates using the password method.
Definition: libsshpp.hpp:240
bool isEof()
returns true if channel is in EOF state
Definition: libsshpp.hpp:500
int ssh_channel_change_pty_size(ssh_channel channel, int cols, int rows)
Change the size of the terminal associated to a channel.
Definition: channels.c:1717
int ssh_connect(ssh_session session)
Connect to the ssh server.
Definition: client.c:488
void ssh_disconnect(ssh_session session)
Disconnect from a session (client or server).
Definition: client.c:643
int getOpensshVersion()
returns the OpenSSH version (server) if possible
Definition: libsshpp.hpp:332
bool isClosed()
returns true if channel is in closed state
Definition: libsshpp.hpp:494
int ssh_userauth_none(ssh_session session, const char *username)
Try to authenticate through the "none" method.
Definition: auth.c:362
ssh_channel ssh_channel_accept_x11(ssh_channel channel, int timeout_ms)
Accept an X11 forwarding channel.
Definition: channels.c:1983
int ssh_channel_listen_forward(ssh_session session, const char *address, int port, int *bound_port)
Sends the "tcpip-forward" global request to ask the server to begin listening for inbound connections...
Definition: channels.c:2187
int ssh_channel_request_send_signal(ssh_channel channel, const char *signum)
Send a signal to remote process (as described in RFC 4254, section 6.9).
Definition: channels.c:2460
std::string getError()
returns the error message of the last exception
Definition: libsshpp.hpp:96
ssh_channel ssh_channel_accept_forward(ssh_session session, int timeout_ms, int *destination_port)
Accept an incoming TCP/IP forwarding channel and get information about incomming connection.
Definition: channels.c:2250
int userauthTryPublickey(ssh_key pubkey)
Try to authenticate using the publickey method.
Definition: libsshpp.hpp:252
void silentDisconnect()
silently disconnect from remote host
Definition: libsshpp.hpp:383
Channel * acceptForward(int timeout_ms)
accept an incoming forward connection
Definition: libsshpp.hpp:654
int ssh_channel_request_exec(ssh_channel channel, const char *cmd)
Run a shell command without an interactive shell.
Definition: channels.c:2390
bool isOpen()
returns true if channel is in open state
Definition: libsshpp.hpp:506
int ssh_channel_request_pty(ssh_channel channel)
Request a PTY.
Definition: channels.c:1698
int userauthKbdintSetAnswer(unsigned int i, const char *answer)
Set the answer for a question from a message block.
Definition: libsshpp.hpp:226
void ssh_silent_disconnect(ssh_session session)
Disconnect impolitely from a remote host by closing the socket.
Definition: session.c:431
void setOption(enum ssh_options_e type, long int option)
sets an SSH session options
Definition: libsshpp.hpp:152
const char * ssh_get_disconnect_message(ssh_session session)
Get the disconnect message from the server.
Definition: session.c:772
ssh_session ssh_new(void)
Create a new ssh session.
Definition: session.c:58
void ssh_channel_free(ssh_channel channel)
Close and free a channel.
Definition: channels.c:1000
int ssh_userauth_try_publickey(ssh_session session, const char *username, const ssh_key pubkey)
Try to authenticate with the given public key.
Definition: auth.c:444
void setOption(enum ssh_options_e type, const char *option)
sets an SSH session options
Definition: libsshpp.hpp:142
int ssh_channel_get_exit_status(ssh_channel channel)
Get the exit status of the channel (error code from the executed instruction).
Definition: channels.c:2972
int ssh_channel_cancel_forward(ssh_session session, const char *address, int port)
Sends the "cancel-tcpip-forward" global request to ask the server to cancel the tcpip-forward request...
Definition: channels.c:2269
int ssh_channel_write_stderr(ssh_channel channel, const void *data, uint32_t len)
Blocking write on a channel stderr.
Definition: channels.c:3229
const char * getDisconnectMessage()
Returns the disconnect message from the server, if any.
Definition: libsshpp.hpp:289
void optionsCopy(const Session &source)
copies options from a session to another
Definition: libsshpp.hpp:367
void ssh_free(ssh_session session)
Deallocate a SSH session handle.
Definition: session.c:170
int ssh_channel_read_nonblocking(ssh_channel channel, void *dest, uint32_t count, int is_stderr)
Do a nonblocking read on the channel.
Definition: channels.c:2791
int ssh_get_error_code(void *error)
Retrieve the error code from the last error.
Definition: error.c:133