307 строки
8.2 KiB
C
307 строки
8.2 KiB
C
/* This is a sample implementation of a libssh based SSH server */
|
|
/*
|
|
Copyright 2003-2009 Aris Adamantiadis
|
|
|
|
This file is part of the SSH Library
|
|
|
|
You are free to copy this file, modify it in any way, consider it being public
|
|
domain. This does not apply to the rest of the library though, but it is
|
|
allowed to cut-and-paste working code from this file to any license of
|
|
program.
|
|
The goal is to show the API in action. It's not a reference on how terminal
|
|
clients must be made or how a client should react.
|
|
*/
|
|
|
|
#include "config.h"
|
|
|
|
#include <libssh/libssh.h>
|
|
#include <libssh/server.h>
|
|
#include <libssh/callbacks.h>
|
|
|
|
#ifdef HAVE_ARGP_H
|
|
#include <argp.h>
|
|
#endif
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <stdio.h>
|
|
|
|
#ifndef KEYS_FOLDER
|
|
#ifdef _WIN32
|
|
#define KEYS_FOLDER
|
|
#else
|
|
#define KEYS_FOLDER "/etc/ssh/"
|
|
#endif
|
|
#endif
|
|
|
|
#define USER "myuser"
|
|
#define PASSWORD "mypassword"
|
|
|
|
static int authenticated=0;
|
|
static int tries = 0;
|
|
static int error = 0;
|
|
static ssh_channel chan=NULL;
|
|
|
|
static int auth_password(ssh_session session, const char *user,
|
|
const char *password, void *userdata){
|
|
(void)userdata;
|
|
printf("Authenticating user %s pwd %s\n",user, password);
|
|
if(strcmp(user,USER) == 0 && strcmp(password, PASSWORD) == 0){
|
|
authenticated = 1;
|
|
printf("Authenticated\n");
|
|
return SSH_AUTH_SUCCESS;
|
|
}
|
|
if (tries >= 3){
|
|
printf("Too many authentication tries\n");
|
|
ssh_disconnect(session);
|
|
error = 1;
|
|
return SSH_AUTH_DENIED;
|
|
}
|
|
tries++;
|
|
return SSH_AUTH_DENIED;
|
|
}
|
|
|
|
static int auth_gssapi_mic(ssh_session session, const char *user, const char *principal, void *userdata){
|
|
ssh_gssapi_creds creds = ssh_gssapi_get_creds(session);
|
|
(void)userdata;
|
|
printf("Authenticating user %s with gssapi principal %s\n",user, principal);
|
|
if (creds != NULL)
|
|
printf("Received some gssapi credentials\n");
|
|
else
|
|
printf("Not received any forwardable creds\n");
|
|
printf("authenticated\n");
|
|
authenticated = 1;
|
|
return SSH_AUTH_SUCCESS;
|
|
}
|
|
|
|
static int pty_request(ssh_session session, ssh_channel channel, const char *term,
|
|
int x,int y, int px, int py, void *userdata){
|
|
(void) session;
|
|
(void) channel;
|
|
(void) term;
|
|
(void) x;
|
|
(void) y;
|
|
(void) px;
|
|
(void) py;
|
|
(void) userdata;
|
|
printf("Allocated terminal\n");
|
|
return 0;
|
|
}
|
|
|
|
static int shell_request(ssh_session session, ssh_channel channel, void *userdata){
|
|
(void)session;
|
|
(void)channel;
|
|
(void)userdata;
|
|
printf("Allocated shell\n");
|
|
return 0;
|
|
}
|
|
struct ssh_channel_callbacks_struct channel_cb = {
|
|
.channel_pty_request_function = pty_request,
|
|
.channel_shell_request_function = shell_request
|
|
};
|
|
|
|
static ssh_channel new_session_channel(ssh_session session, void *userdata){
|
|
(void) session;
|
|
(void) userdata;
|
|
if(chan != NULL)
|
|
return NULL;
|
|
printf("Allocated session channel\n");
|
|
chan = ssh_channel_new(session);
|
|
ssh_callbacks_init(&channel_cb);
|
|
ssh_set_channel_callbacks(chan, &channel_cb);
|
|
return chan;
|
|
}
|
|
|
|
|
|
#ifdef HAVE_ARGP_H
|
|
const char *argp_program_version = "libssh server example "
|
|
SSH_STRINGIFY(LIBSSH_VERSION);
|
|
const char *argp_program_bug_address = "<libssh@libssh.org>";
|
|
|
|
/* Program documentation. */
|
|
static char doc[] = "libssh -- a Secure Shell protocol implementation";
|
|
|
|
/* A description of the arguments we accept. */
|
|
static char args_doc[] = "BINDADDR";
|
|
|
|
/* The options we understand. */
|
|
static struct argp_option options[] = {
|
|
{
|
|
.name = "port",
|
|
.key = 'p',
|
|
.arg = "PORT",
|
|
.flags = 0,
|
|
.doc = "Set the port to bind.",
|
|
.group = 0
|
|
},
|
|
{
|
|
.name = "hostkey",
|
|
.key = 'k',
|
|
.arg = "FILE",
|
|
.flags = 0,
|
|
.doc = "Set the host key.",
|
|
.group = 0
|
|
},
|
|
{
|
|
.name = "dsakey",
|
|
.key = 'd',
|
|
.arg = "FILE",
|
|
.flags = 0,
|
|
.doc = "Set the dsa key.",
|
|
.group = 0
|
|
},
|
|
{
|
|
.name = "rsakey",
|
|
.key = 'r',
|
|
.arg = "FILE",
|
|
.flags = 0,
|
|
.doc = "Set the rsa key.",
|
|
.group = 0
|
|
},
|
|
{
|
|
.name = "verbose",
|
|
.key = 'v',
|
|
.arg = NULL,
|
|
.flags = 0,
|
|
.doc = "Get verbose output.",
|
|
.group = 0
|
|
},
|
|
{NULL, 0, NULL, 0, NULL, 0}
|
|
};
|
|
|
|
/* Parse a single option. */
|
|
static error_t parse_opt (int key, char *arg, struct argp_state *state) {
|
|
/* Get the input argument from argp_parse, which we
|
|
* know is a pointer to our arguments structure.
|
|
*/
|
|
ssh_bind sshbind = state->input;
|
|
|
|
switch (key) {
|
|
case 'p':
|
|
ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_BINDPORT_STR, arg);
|
|
break;
|
|
case 'd':
|
|
ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_DSAKEY, arg);
|
|
break;
|
|
case 'k':
|
|
ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_HOSTKEY, arg);
|
|
break;
|
|
case 'r':
|
|
ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_RSAKEY, arg);
|
|
break;
|
|
case 'v':
|
|
ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_LOG_VERBOSITY_STR, "3");
|
|
break;
|
|
case ARGP_KEY_ARG:
|
|
if (state->arg_num >= 1) {
|
|
/* Too many arguments. */
|
|
argp_usage (state);
|
|
}
|
|
ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_BINDADDR, arg);
|
|
break;
|
|
case ARGP_KEY_END:
|
|
if (state->arg_num < 1) {
|
|
/* Not enough arguments. */
|
|
argp_usage (state);
|
|
}
|
|
break;
|
|
default:
|
|
return ARGP_ERR_UNKNOWN;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Our argp parser. */
|
|
static struct argp argp = {options, parse_opt, args_doc, doc, NULL, NULL, NULL};
|
|
#endif /* HAVE_ARGP_H */
|
|
|
|
int main(int argc, char **argv){
|
|
ssh_session session;
|
|
ssh_bind sshbind;
|
|
ssh_event mainloop;
|
|
struct ssh_server_callbacks_struct cb = {
|
|
.userdata = NULL,
|
|
.auth_password_function = auth_password,
|
|
.auth_gssapi_mic_function = auth_gssapi_mic,
|
|
.channel_open_request_session_function = new_session_channel
|
|
};
|
|
|
|
char buf[2048];
|
|
int i;
|
|
int r;
|
|
|
|
sshbind=ssh_bind_new();
|
|
session=ssh_new();
|
|
|
|
ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_DSAKEY, KEYS_FOLDER "ssh_host_dsa_key");
|
|
ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_RSAKEY, KEYS_FOLDER "ssh_host_rsa_key");
|
|
|
|
#ifdef HAVE_ARGP_H
|
|
/*
|
|
* Parse our arguments; every option seen by parse_opt will
|
|
* be reflected in arguments.
|
|
*/
|
|
argp_parse (&argp, argc, argv, 0, 0, sshbind);
|
|
#else
|
|
(void) argc;
|
|
(void) argv;
|
|
#endif
|
|
|
|
if(ssh_bind_listen(sshbind)<0){
|
|
printf("Error listening to socket: %s\n",ssh_get_error(sshbind));
|
|
return 1;
|
|
}
|
|
r=ssh_bind_accept(sshbind,session);
|
|
if(r==SSH_ERROR){
|
|
printf("error accepting a connection : %s\n",ssh_get_error(sshbind));
|
|
return 1;
|
|
}
|
|
ssh_callbacks_init(&cb);
|
|
ssh_set_server_callbacks(session, &cb);
|
|
|
|
if (ssh_handle_key_exchange(session)) {
|
|
printf("ssh_handle_key_exchange: %s\n", ssh_get_error(session));
|
|
return 1;
|
|
}
|
|
ssh_set_auth_methods(session,SSH_AUTH_METHOD_PASSWORD | SSH_AUTH_METHOD_GSSAPI_MIC);
|
|
mainloop = ssh_event_new();
|
|
ssh_event_add_session(mainloop, session);
|
|
|
|
while (!(authenticated && chan != NULL)){
|
|
if(error)
|
|
break;
|
|
r = ssh_event_dopoll(mainloop, -1);
|
|
if (r == SSH_ERROR){
|
|
printf("Error : %s\n",ssh_get_error(session));
|
|
ssh_disconnect(session);
|
|
return 1;
|
|
}
|
|
}
|
|
if(error){
|
|
printf("Error, exiting loop\n");
|
|
} else
|
|
printf("Authenticated and got a channel\n");
|
|
do{
|
|
i=ssh_channel_read(chan,buf, 2048, 0);
|
|
if(i>0) {
|
|
ssh_channel_write(chan, buf, i);
|
|
if (write(1,buf,i) < 0) {
|
|
printf("error writing to buffer\n");
|
|
return 1;
|
|
}
|
|
if (buf[0] == '\x0d') {
|
|
if (write(1, "\n", 1) < 0) {
|
|
printf("error writing to buffer\n");
|
|
return 1;
|
|
}
|
|
ssh_channel_write(chan, "\n", 1);
|
|
}
|
|
}
|
|
} while (i>0);
|
|
ssh_disconnect(session);
|
|
ssh_bind_free(sshbind);
|
|
ssh_finalize();
|
|
return 0;
|
|
}
|
|
|