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