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Copy pathssh2_agent.c
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248 lines (217 loc) · 6.67 KB
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/*
* Sample showing how to do SSH2 connect using ssh-agent.
*
* The sample code has default values for host name, user name:
*
* "ssh2_agent host user"
*/
#include "libssh2_config.h"
#include <libssh2.h>
#include <libssh2_sftp.h>
#ifdef HAVE_WINDOWS_H
# include <windows.h>
#endif
#ifdef HAVE_WINSOCK2_H
# include <winsock2.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
# include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.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>
#include <stdlib.h>
const char *username="username";
int main(int argc, char *argv[])
{
unsigned long hostaddr;
int sock = -1, i, rc;
struct sockaddr_in sin;
const char *fingerprint;
char *userauthlist;
LIBSSH2_SESSION *session = NULL;
LIBSSH2_CHANNEL *channel;
LIBSSH2_AGENT *agent = NULL;
struct libssh2_agent_publickey *identity, *prev_identity = NULL;
#ifdef WIN32
WSADATA wsadata;
int err;
err = WSAStartup(MAKEWORD(2,0), &wsadata);
if (err != 0) {
fprintf(stderr, "WSAStartup failed with error: %d\n", err);
return 1;
}
#endif
if (argc > 1) {
hostaddr = inet_addr(argv[1]);
} else {
hostaddr = htonl(0x7F000001);
}
if(argc > 2) {
username = argv[2];
}
rc = libssh2_init (0);
if (rc != 0) {
fprintf (stderr, "libssh2 initialization failed (%d)\n", rc);
return 1;
}
/* 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);
if (sock == -1) {
fprintf(stderr, "failed to create socket!\n");
rc = 1;
goto shutdown;
}
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");
goto shutdown;
}
/* 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_handshake(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_SHA1);
fprintf(stderr, "Fingerprint: ");
for(i = 0; i < 20; i++) {
fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
}
fprintf(stderr, "\n");
/* check what authentication methods are available */
userauthlist = libssh2_userauth_list(session, username, strlen(username));
fprintf(stderr, "Authentication methods: %s\n", userauthlist);
if (strstr(userauthlist, "publickey") == NULL) {
fprintf(stderr, "\"publickey\" authentication is not supported\n");
goto shutdown;
}
/* Connect to the ssh-agent */
agent = libssh2_agent_init(session);
if (!agent) {
fprintf(stderr, "Failure initializing ssh-agent support\n");
rc = 1;
goto shutdown;
}
if (libssh2_agent_connect(agent)) {
fprintf(stderr, "Failure connecting to ssh-agent\n");
rc = 1;
goto shutdown;
}
if (libssh2_agent_list_identities(agent)) {
fprintf(stderr, "Failure requesting identities to ssh-agent\n");
rc = 1;
goto shutdown;
}
while (1) {
rc = libssh2_agent_get_identity(agent, &identity, prev_identity);
if (rc == 1)
break;
if (rc < 0) {
fprintf(stderr,
"Failure obtaining identity from ssh-agent support\n");
rc = 1;
goto shutdown;
}
if (libssh2_agent_userauth(agent, username, identity)) {
fprintf(stderr, "\tAuthentication with username %s and "
"public key %s failed!\n",
username, identity->comment);
} else {
fprintf(stderr, "\tAuthentication with username %s and "
"public key %s succeeded!\n",
username, identity->comment);
break;
}
prev_identity = identity;
}
if (rc) {
fprintf(stderr, "Couldn't continue authentication\n");
goto shutdown;
}
/* We're authenticated now. */
/* 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, "FOO", "bar");
/* Request a terminal with 'vanilla' terminal emulation
* See /etc/termcap for more options
*/
if (libssh2_channel_request_pty(channel, "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_recv2()
* libssh2_channel_direct_tcpip()
*/
shutdown:
libssh2_agent_disconnect(agent);
libssh2_agent_free(agent);
if(session) {
libssh2_session_disconnect(session,
"Normal Shutdown, Thank you for playing");
libssh2_session_free(session);
}
if (sock != -1) {
#ifdef WIN32
closesocket(sock);
#else
close(sock);
#endif
}
fprintf(stderr, "all done!\n");
libssh2_exit();
return rc;
}