ssh2/example/simple/ssh2.c

/*
 * $Id: ssh2.c,v 1.11 2007/07/19 15:43:48 gknauf Exp $
 *
 * Sample showing how to do SSH2 connect.
 *
 * The sample code has default values for host name, user name, password
 * and path to copy, but you can specify them on the command line like:
 *
 * "ssh2 host user password"
 */

#include <libssh2.h>
#include <libssh2_sftp.h>
#include <libssh2_config.h>

#ifdef HAVE_WINSOCK2_H
# include <winsock2.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
# include <sys/socket.h>
#endif
# ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
# ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif

#include <sys/types.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <ctype.h>

int main(int argc, char *argv[])
{
    unsigned long hostaddr;
    int sock, i, auth_pw = 0;
    struct sockaddr_in sin;
    const char *fingerprint;
    char *userauthlist;
    LIBSSH2_SESSION *session;
    LIBSSH2_CHANNEL *channel;
    char *username=(char *)"username";
    char *password=(char *)"password";
    char *keyfile1=(char *)"~/.ssh/id_rsa.pub";
    char *keyfile2=(char *)"~/.ssh/id_rsa";
#ifdef WIN32
    WSADATA wsadata;

    WSAStartup(WINSOCK_VERSION, &wsadata);
#endif

    if (argc > 1) {
        hostaddr = inet_addr(argv[1]);
    } else {
        hostaddr = htonl(0x7F000001);
    }

    if(argc > 2) {
        username = argv[2];
    }
    if(argc > 3) {
        password = argv[3];
    }

    /* Ultra basic "connect to port 22 on localhost"
     * Your code is responsible for creating the socket establishing the connection
     */
    sock = socket(AF_INET, SOCK_STREAM, 0);
#ifndef WIN32
    fcntl(sock, F_SETFL, 0);
#endif
    sin.sin_family = AF_INET;
    sin.sin_port = htons(22);
    sin.sin_addr.s_addr = hostaddr;
    if (connect(sock, (struct sockaddr*)(&sin),
                sizeof(struct sockaddr_in)) != 0) {
        fprintf(stderr, "failed to connect!\n");
        return -1;
    }

    /* Create a session instance and start it up
     * This will trade welcome banners, exchange keys, and setup crypto, compression, and MAC layers
     */
    session = libssh2_session_init();
    if (libssh2_session_startup(session, sock)) {
        fprintf(stderr, "Failure establishing SSH session\n");
        return -1;
    }

    /* At this point we havn't authenticated,
     * The first thing to do is check the hostkey's fingerprint against our known hosts
     * Your app may have it hard coded, may go to a file, may present it to the user, that's your call
     */
    fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_MD5);
    printf("Fingerprint: ");
    for(i = 0; i < 16; i++) {
        printf("%02X ", (unsigned char)fingerprint[i]);
    }
    printf("\n");

    /* check what authentication methods are available */
    userauthlist = libssh2_userauth_list(session, username, sizeof(username));
    printf("Authentication methods: %s\n", userauthlist);
    if (strstr(userauthlist, "password") != NULL) {
        auth_pw |= 1;
    }
    if (strstr(userauthlist, "publickey") != NULL) {
        auth_pw |= 2;
    }
    if (strstr(userauthlist, "keyboard-interactive") != NULL) {
        auth_pw |= 4;
    }

    if (auth_pw & 1) {
        /* We could authenticate via password */
        if (libssh2_userauth_password(session, username, password)) {
            printf("\tAuthentication by password failed!\n");
            goto shutdown;
        } else {
            printf("\tAuthentication by password succeeded.\n");
        }
    } else if (auth_pw & 2) {
        /* Or by public key */
        if (libssh2_userauth_publickey_fromfile(session, username, keyfile1, keyfile2, password)) {
            printf("\tAuthentication by public key failed!\n");
            goto shutdown;
        } else {
            printf("\tAuthentication by public key succeeded.\n");
        }
#if 0 /* !! not implemented yet !! */
    } else if (auth_pw & 4) {
        /* Or via keyboard-interactive */
        if (libssh2_userauth_keyboard_interactive(session, username, getpw_callback) ) {
            printf("\tAuthentication by keyboard-interactive failed!\n");
            goto shutdown;
        } else {
            printf("\tAuthentication by keyboard-interactive succeeded.\n");
        }
#endif
    } else {
        printf("No supported authentication methods found!\n");
        goto shutdown;
    }

    /* Request a shell */
    if (!(channel = libssh2_channel_open_session(session))) {
        fprintf(stderr, "Unable to open a session\n");
        goto shutdown;
    }

    /* Some environment variables may be set,
     * It's up to the server which ones it'll allow though
     */
    libssh2_channel_setenv(channel, (char *)"FOO", (char *)"bar");

    /* Request a terminal with 'vanilla' terminal emulation
     * See /etc/termcap for more options
     */
    if (libssh2_channel_request_pty(channel, (char *)"vanilla")) {
        fprintf(stderr, "Failed requesting pty\n");
        goto skip_shell;
    }

    /* Open a SHELL on that pty */
    if (libssh2_channel_shell(channel)) {
        fprintf(stderr, "Unable to request shell on allocated pty\n");
        goto shutdown;
    }

    /* At this point the shell can be interacted with using
     * libssh2_channel_read()
     * libssh2_channel_read_stderr()
     * libssh2_channel_write()
     * libssh2_channel_write_stderr()
     *
     * Blocking mode may be (en|dis)abled with: libssh2_channel_set_blocking()
     * If the server send EOF, libssh2_channel_eof() will return non-0
     * To send EOF to the server use: libssh2_channel_send_eof()
     * A channel can be closed with: libssh2_channel_close()
     * A channel can be freed with: libssh2_channel_free()
     */

  skip_shell:
    if (channel) {
        libssh2_channel_free(channel);
        channel = NULL;
    }

    /* Other channel types are supported via:
     * libssh2_scp_send()
     * libssh2_scp_recv()
     * libssh2_channel_direct_tcpip()
     */

  shutdown:

    libssh2_session_disconnect(session, "Normal Shutdown, Thank you for playing");
    libssh2_session_free(session);

#ifdef WIN32
    Sleep(1000);
    closesocket(sock);
#else
    sleep(1);
    close(sock);
#endif
    printf("all done!\n");
    return 0;
}