text: /*
   * 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 [-p|-i|-k]"
   */
  
  #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>
  
  
  const char *keyfile1 = "~/.ssh/id_rsa.pub";
  const char *keyfile2 = "~/.ssh/id_rsa";
  const char *username = "username";
  const char *password = "password";
  
  
  static void kbd_callback(const char *name, int name_len,
                           const char *instruction, int instruction_len,
                           int num_prompts,
                           const LIBSSH2_USERAUTH_KBDINT_PROMPT *prompts,
                           LIBSSH2_USERAUTH_KBDINT_RESPONSE *responses,
                           void **abstract)
  {
      (void)name;
      (void)name_len;
      (void)instruction;
      (void)instruction_len;
      if(num_prompts == 1) {
          responses[0].text = strdup(password);
          responses[0].length = strlen(password);
      }
      (void)prompts;
      (void)abstract;
  } /* kbd_callback */
  
  
  int main(int argc, char *argv[])
  {
      unsigned long hostaddr;
      int rc, sock, i, auth_pw = 0;
      struct sockaddr_in sin;
      const char *fingerprint;
      char *userauthlist;
      LIBSSH2_SESSION *session;
      LIBSSH2_CHANNEL *channel;
  
  #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];
      }
      if(argc > 3) {
          password = argv[3];
      }
  
      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);
  
      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_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, "password") != NULL) {
          auth_pw |= 1;
      }
      if(strstr(userauthlist, "keyboard-interactive") != NULL) {
          auth_pw |= 2;
      }
      if(strstr(userauthlist, "publickey") != NULL) {
          auth_pw |= 4;
      }
  
      /* if we got an 4. argument we set this option if supported */
      if(argc > 4) {
          if((auth_pw & 1) && !strcasecmp(argv[4], "-p")) {
              auth_pw = 1;
          }
          if((auth_pw & 2) && !strcasecmp(argv[4], "-i")) {
              auth_pw = 2;
          }
          if((auth_pw & 4) && !strcasecmp(argv[4], "-k")) {
              auth_pw = 4;
          }
      }
  
      if(auth_pw & 1) {
          /* We could authenticate via password */
          if(libssh2_userauth_password(session, username, password)) {
  
              fprintf(stderr, "\tAuthentication by password failed!\n");
              goto shutdown;
          }
          else {
              fprintf(stderr, "\tAuthentication by password succeeded.\n");
          }
      }
      else if(auth_pw & 2) {
          /* Or via keyboard-interactive */
          if(libssh2_userauth_keyboard_interactive(session, username,
  
                                                   &kbd_callback) ) {
              fprintf(stderr,
                      "\tAuthentication by keyboard-interactive failed!\n");
              goto shutdown;
          }
          else {
              fprintf(stderr,
                      "\tAuthentication by keyboard-interactive succeeded.\n");
          }
      }
      else if(auth_pw & 4) {
          /* Or by public key */
          if(libssh2_userauth_publickey_fromfile(session, username, keyfile1,
  
                                                 keyfile2, password)) {
              fprintf(stderr, "\tAuthentication by public key failed!\n");
              goto shutdown;
          }
          else {
              fprintf(stderr, "\tAuthentication by public key succeeded.\n");
          }
      }
      else {
          fprintf(stderr, "No supported authentication methods found!\n");
          goto shutdown;
      }
  
      /* Request a shell */
      channel = libssh2_channel_open_session(session);
  
      if(!channel) {
          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_session_disconnect(session,
  
                                 "Normal Shutdown, Thank you for playing");
      libssh2_session_free(session);
  
  
  #ifdef WIN32
      closesocket(sock);
  #else
      close(sock);
  #endif
      fprintf(stderr, "all done!\n");
  
      libssh2_exit();
  
  
      return 0;
  }