libssh2/example/simple/ssh2.c

/*
 * $Id: ssh2.c,v 1.3 2007/04/26 23:59:15 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

#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 = 1;
	struct sockaddr_in sin;
	const char *fingerprint;
	LIBSSH2_SESSION *session;
	LIBSSH2_CHANNEL *channel;
	char *username=(char *)"username";
	char *password=(char *)"password";
#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");

	if (auth_pw) {
		/* We could authenticate via password */
		if (libssh2_userauth_password(session, username, password)) {
			printf("Authentication by password failed.\n");
			goto shutdown;
		}
	} else {
		/* Or by public key */
		if (libssh2_userauth_publickey_fromfile(session, username, "/home/username/.ssh/id_rsa.pub", "/home/username/.ssh/id_rsa", password)) {
			printf("\tAuthentication by public key failed\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;
}