2014-03-22 15:23:38 +00:00
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/* $OpenBSD: sshconnect.c,v 1.246 2014/02/06 22:21:01 djm Exp $ */
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2000-02-24 14:29:47 +00:00
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/*
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* Author: Tatu Ylonen <ylo@cs.hut.fi>
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* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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* All rights reserved
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* Code to connect to a remote host, and to perform the client side of the
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* login (authentication) dialog.
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2000-09-10 09:35:38 +00:00
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*
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* As far as I am concerned, the code I have written for this software
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* can be used freely for any purpose. Any derived versions of this
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* software must be clearly marked as such, and if the derived work is
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* incompatible with the protocol description in the RFC file, it must be
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* called by a name other than "ssh" or "Secure Shell".
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2000-02-24 14:29:47 +00:00
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*/
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#include "includes.h"
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2014-03-24 19:15:13 +00:00
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__RCSID("$FreeBSD$");
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2000-02-24 14:29:47 +00:00
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2006-09-30 13:38:06 +00:00
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <sys/stat.h>
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#include <sys/socket.h>
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#ifdef HAVE_SYS_TIME_H
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# include <sys/time.h>
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#endif
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#include <netinet/in.h>
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#include <arpa/inet.h>
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2014-01-31 13:12:02 +00:00
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#include <rpc/rpc.h>
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2006-09-30 13:38:06 +00:00
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#include <ctype.h>
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#include <errno.h>
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2010-03-08 11:19:52 +00:00
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#include <fcntl.h>
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2006-09-30 13:38:06 +00:00
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#include <netdb.h>
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#ifdef HAVE_PATHS_H
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#include <paths.h>
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#endif
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#include <pwd.h>
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2011-02-17 11:47:40 +00:00
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#include <signal.h>
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2006-09-30 13:38:06 +00:00
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#include <stdarg.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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2000-05-15 05:24:25 +00:00
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2000-02-24 14:29:47 +00:00
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#include "xmalloc.h"
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2006-09-30 13:38:06 +00:00
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#include "key.h"
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#include "hostfile.h"
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#include "ssh.h"
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2000-02-24 14:29:47 +00:00
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#include "rsa.h"
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2000-05-15 05:24:25 +00:00
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#include "buffer.h"
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2000-02-24 14:29:47 +00:00
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#include "packet.h"
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#include "uidswap.h"
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#include "compat.h"
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2000-03-26 07:37:48 +00:00
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#include "key.h"
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2000-05-15 05:24:25 +00:00
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#include "sshconnect.h"
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2000-03-26 07:37:48 +00:00
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#include "hostfile.h"
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2001-05-04 04:14:23 +00:00
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#include "log.h"
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#include "readconf.h"
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#include "atomicio.h"
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#include "misc.h"
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2004-01-07 11:16:27 +00:00
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#include "dns.h"
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2009-10-01 15:19:37 +00:00
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#include "roaming.h"
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2014-01-30 10:56:49 +00:00
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#include "monitor_fdpass.h"
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2010-03-08 11:19:52 +00:00
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#include "ssh2.h"
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2006-09-30 13:38:06 +00:00
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#include "version.h"
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2004-01-07 11:16:27 +00:00
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2000-05-15 05:24:25 +00:00
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char *client_version_string = NULL;
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char *server_version_string = NULL;
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2000-02-24 14:29:47 +00:00
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2006-03-22 20:41:37 +00:00
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static int matching_host_key_dns = 0;
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2004-01-07 11:16:27 +00:00
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2011-02-17 11:47:40 +00:00
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static pid_t proxy_command_pid = 0;
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2002-06-23 16:09:08 +00:00
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/* import */
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2000-02-24 14:29:47 +00:00
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extern Options options;
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extern char *__progname;
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2002-06-23 16:09:08 +00:00
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extern uid_t original_real_uid;
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extern uid_t original_effective_uid;
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2000-02-24 14:29:47 +00:00
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2011-02-17 11:47:40 +00:00
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static int show_other_keys(struct hostkeys *, Key *);
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2004-02-26 10:52:33 +00:00
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static void warn_changed_key(Key *);
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2001-05-04 04:14:23 +00:00
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2014-01-30 10:56:49 +00:00
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/* Expand a proxy command */
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static char *
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expand_proxy_command(const char *proxy_command, const char *user,
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const char *host, int port)
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{
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char *tmp, *ret, strport[NI_MAXSERV];
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snprintf(strport, sizeof strport, "%d", port);
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xasprintf(&tmp, "exec %s", proxy_command);
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ret = percent_expand(tmp, "h", host, "p", strport,
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"r", options.user, (char *)NULL);
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free(tmp);
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return ret;
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}
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/*
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* Connect to the given ssh server using a proxy command that passes a
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* a connected fd back to us.
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*/
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static int
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ssh_proxy_fdpass_connect(const char *host, u_short port,
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const char *proxy_command)
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{
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char *command_string;
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int sp[2], sock;
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pid_t pid;
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char *shell;
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if ((shell = getenv("SHELL")) == NULL)
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shell = _PATH_BSHELL;
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if (socketpair(AF_UNIX, SOCK_STREAM, 0, sp) < 0)
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fatal("Could not create socketpair to communicate with "
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"proxy dialer: %.100s", strerror(errno));
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command_string = expand_proxy_command(proxy_command, options.user,
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host, port);
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debug("Executing proxy dialer command: %.500s", command_string);
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/* Fork and execute the proxy command. */
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if ((pid = fork()) == 0) {
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char *argv[10];
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/* Child. Permanently give up superuser privileges. */
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permanently_drop_suid(original_real_uid);
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close(sp[1]);
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/* Redirect stdin and stdout. */
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if (sp[0] != 0) {
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if (dup2(sp[0], 0) < 0)
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perror("dup2 stdin");
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}
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if (sp[0] != 1) {
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if (dup2(sp[0], 1) < 0)
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perror("dup2 stdout");
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}
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if (sp[0] >= 2)
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close(sp[0]);
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/*
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* Stderr is left as it is so that error messages get
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* printed on the user's terminal.
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*/
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argv[0] = shell;
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argv[1] = "-c";
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argv[2] = command_string;
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argv[3] = NULL;
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/*
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* Execute the proxy command.
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* Note that we gave up any extra privileges above.
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*/
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execv(argv[0], argv);
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perror(argv[0]);
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exit(1);
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}
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/* Parent. */
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if (pid < 0)
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fatal("fork failed: %.100s", strerror(errno));
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close(sp[0]);
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free(command_string);
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if ((sock = mm_receive_fd(sp[1])) == -1)
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fatal("proxy dialer did not pass back a connection");
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while (waitpid(pid, NULL, 0) == -1)
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if (errno != EINTR)
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fatal("Couldn't wait for child: %s", strerror(errno));
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/* Set the connection file descriptors. */
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packet_set_connection(sock, sock);
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return 0;
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}
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2000-02-24 14:29:47 +00:00
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/*
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* Connect to the given ssh server using a proxy command.
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*/
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2002-03-18 10:09:43 +00:00
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static int
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2002-06-23 16:09:08 +00:00
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ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
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2000-02-24 14:29:47 +00:00
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{
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2014-01-30 10:56:49 +00:00
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char *command_string;
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2000-02-24 14:29:47 +00:00
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int pin[2], pout[2];
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2000-05-15 05:24:25 +00:00
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pid_t pid;
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2014-01-30 10:56:49 +00:00
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char *shell;
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2013-05-17 09:12:33 +00:00
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2011-02-17 11:47:40 +00:00
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if ((shell = getenv("SHELL")) == NULL || *shell == '\0')
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2008-07-23 09:28:49 +00:00
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shell = _PATH_BSHELL;
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2000-02-24 14:29:47 +00:00
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/* Create pipes for communicating with the proxy. */
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if (pipe(pin) < 0 || pipe(pout) < 0)
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fatal("Could not create pipes to communicate with the proxy: %.100s",
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2002-03-18 10:09:43 +00:00
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strerror(errno));
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2000-02-24 14:29:47 +00:00
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2014-01-30 10:56:49 +00:00
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command_string = expand_proxy_command(proxy_command, options.user,
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host, port);
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2000-02-24 14:29:47 +00:00
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debug("Executing proxy command: %.500s", command_string);
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/* Fork and execute the proxy command. */
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if ((pid = fork()) == 0) {
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char *argv[10];
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/* Child. Permanently give up superuser privileges. */
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2006-09-30 13:38:06 +00:00
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permanently_drop_suid(original_real_uid);
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2000-02-24 14:29:47 +00:00
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/* Redirect stdin and stdout. */
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close(pin[1]);
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if (pin[0] != 0) {
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if (dup2(pin[0], 0) < 0)
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perror("dup2 stdin");
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close(pin[0]);
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}
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close(pout[0]);
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if (dup2(pout[1], 1) < 0)
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perror("dup2 stdout");
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/* Cannot be 1 because pin allocated two descriptors. */
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close(pout[1]);
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/* Stderr is left as it is so that error messages get
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printed on the user's terminal. */
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2008-07-23 09:28:49 +00:00
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argv[0] = shell;
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2000-02-24 14:29:47 +00:00
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argv[1] = "-c";
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argv[2] = command_string;
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argv[3] = NULL;
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/* Execute the proxy command. Note that we gave up any
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extra privileges above. */
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2011-02-17 11:47:40 +00:00
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signal(SIGPIPE, SIG_DFL);
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2001-05-04 04:14:23 +00:00
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execv(argv[0], argv);
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perror(argv[0]);
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2000-02-24 14:29:47 +00:00
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exit(1);
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}
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/* Parent. */
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if (pid < 0)
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fatal("fork failed: %.100s", strerror(errno));
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2002-10-29 10:16:02 +00:00
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else
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proxy_command_pid = pid; /* save pid to clean up later */
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2000-02-24 14:29:47 +00:00
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/* Close child side of the descriptors. */
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close(pin[0]);
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close(pout[1]);
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/* Free the command name. */
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2013-09-18 17:27:38 +00:00
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free(command_string);
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2000-02-24 14:29:47 +00:00
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/* Set the connection file descriptors. */
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packet_set_connection(pout[0], pin[1]);
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2002-03-18 10:09:43 +00:00
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/* Indicate OK return */
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return 0;
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2000-02-24 14:29:47 +00:00
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}
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2011-02-17 11:47:40 +00:00
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void
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ssh_kill_proxy_command(void)
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{
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/*
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* Send SIGHUP to proxy command if used. We don't wait() in
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* case it hangs and instead rely on init to reap the child
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*/
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if (proxy_command_pid > 1)
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kill(proxy_command_pid, SIGHUP);
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}
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2011-08-03 19:14:22 +00:00
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/*
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* Set TCP receive buffer if requested.
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* Note: tuning needs to happen after the socket is created but before the
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* connection happens so winscale is negotiated properly.
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*/
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static void
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ssh_set_socket_recvbuf(int sock)
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{
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void *buf = (void *)&options.tcp_rcv_buf;
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int socksize, sz = sizeof(options.tcp_rcv_buf);
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socklen_t len = sizeof(int);
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debug("setsockopt attempting to set SO_RCVBUF to %d",
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options.tcp_rcv_buf);
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if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF, buf, sz) >= 0) {
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getsockopt(sock, SOL_SOCKET, SO_RCVBUF, &socksize, &len);
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debug("setsockopt SO_RCVBUF: %.100s %d", strerror(errno),
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socksize);
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} else
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error("Couldn't set socket receive buffer to %d: %.100s",
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options.tcp_rcv_buf, strerror(errno));
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}
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2000-02-24 14:29:47 +00:00
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/*
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* Creates a (possibly privileged) socket for use as the ssh connection.
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*/
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2002-03-18 10:09:43 +00:00
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static int
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2004-01-07 11:16:27 +00:00
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ssh_create_socket(int privileged, struct addrinfo *ai)
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2000-02-24 14:29:47 +00:00
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{
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2014-01-30 10:56:49 +00:00
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int sock, r, gaierr;
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2014-03-22 15:23:38 +00:00
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struct addrinfo hints, *res = NULL;
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2000-02-24 14:29:47 +00:00
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2004-01-07 11:16:27 +00:00
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sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
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2010-03-08 11:19:52 +00:00
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if (sock < 0) {
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2014-01-30 10:56:49 +00:00
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error("socket: %s", strerror(errno));
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2010-03-08 11:19:52 +00:00
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return -1;
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}
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fcntl(sock, F_SETFD, FD_CLOEXEC);
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2002-03-18 10:09:43 +00:00
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2011-08-03 19:14:22 +00:00
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if (options.tcp_rcv_buf > 0)
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ssh_set_socket_recvbuf(sock);
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2002-03-18 10:09:43 +00:00
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/* Bind the socket to an alternative local IP address */
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2014-01-30 10:56:49 +00:00
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if (options.bind_address == NULL && !privileged)
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2002-03-18 10:09:43 +00:00
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return sock;
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2014-03-22 15:23:38 +00:00
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if (options.bind_address) {
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memset(&hints, 0, sizeof(hints));
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hints.ai_family = ai->ai_family;
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hints.ai_socktype = ai->ai_socktype;
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|
|
hints.ai_protocol = ai->ai_protocol;
|
|
|
|
hints.ai_flags = AI_PASSIVE;
|
|
|
|
gaierr = getaddrinfo(options.bind_address, NULL, &hints, &res);
|
|
|
|
if (gaierr) {
|
|
|
|
error("getaddrinfo: %s: %s", options.bind_address,
|
|
|
|
ssh_gai_strerror(gaierr));
|
|
|
|
close(sock);
|
|
|
|
return -1;
|
|
|
|
}
|
2002-03-18 10:09:43 +00:00
|
|
|
}
|
2014-01-30 10:56:49 +00:00
|
|
|
/*
|
|
|
|
* If we are running as root and want to connect to a privileged
|
|
|
|
* port, bind our own socket to a privileged port.
|
|
|
|
*/
|
|
|
|
if (privileged) {
|
|
|
|
PRIV_START;
|
2014-03-22 15:23:38 +00:00
|
|
|
r = bindresvport_sa(sock, res ? res->ai_addr : NULL);
|
2014-01-30 10:56:49 +00:00
|
|
|
PRIV_END;
|
|
|
|
if (r < 0) {
|
|
|
|
error("bindresvport_sa: af=%d %s", ai->ai_family,
|
|
|
|
strerror(errno));
|
|
|
|
goto fail;
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
|
|
|
|
error("bind: %s: %s", options.bind_address,
|
|
|
|
strerror(errno));
|
|
|
|
fail:
|
|
|
|
close(sock);
|
|
|
|
freeaddrinfo(res);
|
|
|
|
return -1;
|
|
|
|
}
|
2002-03-18 10:09:43 +00:00
|
|
|
}
|
2014-03-22 15:23:38 +00:00
|
|
|
if (res != NULL)
|
|
|
|
freeaddrinfo(res);
|
2000-02-24 14:29:47 +00:00
|
|
|
return sock;
|
|
|
|
}
|
|
|
|
|
2004-01-07 11:16:27 +00:00
|
|
|
static int
|
|
|
|
timeout_connect(int sockfd, const struct sockaddr *serv_addr,
|
2008-07-23 09:28:49 +00:00
|
|
|
socklen_t addrlen, int *timeoutp)
|
2004-01-07 11:16:27 +00:00
|
|
|
{
|
|
|
|
fd_set *fdset;
|
2008-07-23 09:28:49 +00:00
|
|
|
struct timeval tv, t_start;
|
2004-01-07 11:16:27 +00:00
|
|
|
socklen_t optlen;
|
2006-09-30 13:38:06 +00:00
|
|
|
int optval, rc, result = -1;
|
2004-01-07 11:16:27 +00:00
|
|
|
|
2008-07-23 09:28:49 +00:00
|
|
|
gettimeofday(&t_start, NULL);
|
|
|
|
|
|
|
|
if (*timeoutp <= 0) {
|
|
|
|
result = connect(sockfd, serv_addr, addrlen);
|
|
|
|
goto done;
|
|
|
|
}
|
2004-01-07 11:16:27 +00:00
|
|
|
|
2004-02-26 10:52:33 +00:00
|
|
|
set_nonblock(sockfd);
|
2004-01-07 11:16:27 +00:00
|
|
|
rc = connect(sockfd, serv_addr, addrlen);
|
2004-02-26 10:52:33 +00:00
|
|
|
if (rc == 0) {
|
|
|
|
unset_nonblock(sockfd);
|
2008-07-23 09:28:49 +00:00
|
|
|
result = 0;
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
if (errno != EINPROGRESS) {
|
|
|
|
result = -1;
|
|
|
|
goto done;
|
2004-02-26 10:52:33 +00:00
|
|
|
}
|
2004-01-07 11:16:27 +00:00
|
|
|
|
2006-09-30 13:38:06 +00:00
|
|
|
fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS),
|
|
|
|
sizeof(fd_mask));
|
2004-01-07 11:16:27 +00:00
|
|
|
FD_SET(sockfd, fdset);
|
2008-07-23 09:28:49 +00:00
|
|
|
ms_to_timeval(&tv, *timeoutp);
|
2004-01-07 11:16:27 +00:00
|
|
|
|
2005-06-05 15:46:09 +00:00
|
|
|
for (;;) {
|
2004-01-07 11:16:27 +00:00
|
|
|
rc = select(sockfd + 1, NULL, fdset, NULL, &tv);
|
|
|
|
if (rc != -1 || errno != EINTR)
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
2005-06-05 15:46:09 +00:00
|
|
|
switch (rc) {
|
2004-01-07 11:16:27 +00:00
|
|
|
case 0:
|
|
|
|
/* Timed out */
|
|
|
|
errno = ETIMEDOUT;
|
|
|
|
break;
|
|
|
|
case -1:
|
|
|
|
/* Select error */
|
2004-02-26 10:52:33 +00:00
|
|
|
debug("select: %s", strerror(errno));
|
2004-01-07 11:16:27 +00:00
|
|
|
break;
|
|
|
|
case 1:
|
|
|
|
/* Completed or failed */
|
|
|
|
optval = 0;
|
|
|
|
optlen = sizeof(optval);
|
2004-02-26 10:52:33 +00:00
|
|
|
if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval,
|
2004-01-07 11:16:27 +00:00
|
|
|
&optlen) == -1) {
|
2004-02-26 10:52:33 +00:00
|
|
|
debug("getsockopt: %s", strerror(errno));
|
2004-01-07 11:16:27 +00:00
|
|
|
break;
|
|
|
|
}
|
|
|
|
if (optval != 0) {
|
|
|
|
errno = optval;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
result = 0;
|
2004-02-26 10:52:33 +00:00
|
|
|
unset_nonblock(sockfd);
|
2004-01-07 11:16:27 +00:00
|
|
|
break;
|
|
|
|
default:
|
|
|
|
/* Should not occur */
|
|
|
|
fatal("Bogus return (%d) from select()", rc);
|
|
|
|
}
|
|
|
|
|
2013-09-18 17:27:38 +00:00
|
|
|
free(fdset);
|
2008-07-23 09:28:49 +00:00
|
|
|
|
|
|
|
done:
|
|
|
|
if (result == 0 && *timeoutp > 0) {
|
|
|
|
ms_subtract_diff(&t_start, timeoutp);
|
|
|
|
if (*timeoutp <= 0) {
|
|
|
|
errno = ETIMEDOUT;
|
|
|
|
result = -1;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2004-01-07 11:16:27 +00:00
|
|
|
return (result);
|
|
|
|
}
|
|
|
|
|
2000-02-24 14:29:47 +00:00
|
|
|
/*
|
|
|
|
* Opens a TCP/IP connection to the remote server on the given host.
|
|
|
|
* The address of the remote host will be returned in hostaddr.
|
2002-06-23 16:09:08 +00:00
|
|
|
* If port is 0, the default port will be used. If needpriv is true,
|
2000-02-24 14:29:47 +00:00
|
|
|
* a privileged port will be allocated to make the connection.
|
2002-06-23 16:09:08 +00:00
|
|
|
* This requires super-user privileges if needpriv is true.
|
2000-02-24 14:29:47 +00:00
|
|
|
* Connection_attempts specifies the maximum number of tries (one per
|
|
|
|
* second). If proxy_command is non-NULL, it specifies the command (with %h
|
|
|
|
* and %p substituted for host and port, respectively) to use to contact
|
|
|
|
* the daemon.
|
|
|
|
*/
|
2014-01-30 10:56:49 +00:00
|
|
|
static int
|
|
|
|
ssh_connect_direct(const char *host, struct addrinfo *aitop,
|
|
|
|
struct sockaddr_storage *hostaddr, u_short port, int family,
|
|
|
|
int connection_attempts, int *timeout_ms, int want_keepalive, int needpriv)
|
2000-02-24 14:29:47 +00:00
|
|
|
{
|
2001-05-04 04:14:23 +00:00
|
|
|
int on = 1;
|
2000-02-24 14:29:47 +00:00
|
|
|
int sock = -1, attempt;
|
|
|
|
char ntop[NI_MAXHOST], strport[NI_MAXSERV];
|
2014-01-30 10:56:49 +00:00
|
|
|
struct addrinfo *ai;
|
2000-02-24 14:29:47 +00:00
|
|
|
|
2003-04-23 17:13:13 +00:00
|
|
|
debug2("ssh_connect: needpriv %d", needpriv);
|
2000-02-24 14:29:47 +00:00
|
|
|
|
2006-09-30 13:38:06 +00:00
|
|
|
for (attempt = 0; attempt < connection_attempts; attempt++) {
|
2006-11-10 16:52:41 +00:00
|
|
|
if (attempt > 0) {
|
|
|
|
/* Sleep a moment before retrying. */
|
|
|
|
sleep(1);
|
2000-02-24 14:29:47 +00:00
|
|
|
debug("Trying again...");
|
2006-11-10 16:52:41 +00:00
|
|
|
}
|
2006-09-30 13:38:06 +00:00
|
|
|
/*
|
|
|
|
* Loop through addresses for this host, and try each one in
|
|
|
|
* sequence until the connection succeeds.
|
|
|
|
*/
|
2000-02-24 14:29:47 +00:00
|
|
|
for (ai = aitop; ai; ai = ai->ai_next) {
|
2014-01-30 10:56:49 +00:00
|
|
|
if (ai->ai_family != AF_INET &&
|
|
|
|
ai->ai_family != AF_INET6)
|
2000-02-24 14:29:47 +00:00
|
|
|
continue;
|
|
|
|
if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
|
|
|
|
ntop, sizeof(ntop), strport, sizeof(strport),
|
|
|
|
NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
|
|
|
|
error("ssh_connect: getnameinfo failed");
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
debug("Connecting to %.200s [%.100s] port %s.",
|
2001-05-03 00:26:47 +00:00
|
|
|
host, ntop, strport);
|
2000-02-24 14:29:47 +00:00
|
|
|
|
|
|
|
/* Create a socket for connecting. */
|
2004-01-07 11:16:27 +00:00
|
|
|
sock = ssh_create_socket(needpriv, ai);
|
2000-02-24 14:29:47 +00:00
|
|
|
if (sock < 0)
|
2002-03-18 10:09:43 +00:00
|
|
|
/* Any error is already output */
|
2000-02-24 14:29:47 +00:00
|
|
|
continue;
|
|
|
|
|
2004-01-07 11:16:27 +00:00
|
|
|
if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen,
|
2008-07-23 09:28:49 +00:00
|
|
|
timeout_ms) >= 0) {
|
2000-02-24 14:29:47 +00:00
|
|
|
/* Successful connection. */
|
2001-05-04 04:14:23 +00:00
|
|
|
memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
|
2000-02-24 14:29:47 +00:00
|
|
|
break;
|
|
|
|
} else {
|
2002-10-29 10:16:02 +00:00
|
|
|
debug("connect to address %s port %s: %s",
|
|
|
|
ntop, strport, strerror(errno));
|
2000-02-24 14:29:47 +00:00
|
|
|
close(sock);
|
2006-09-30 13:38:06 +00:00
|
|
|
sock = -1;
|
2000-02-24 14:29:47 +00:00
|
|
|
}
|
|
|
|
}
|
2006-09-30 13:38:06 +00:00
|
|
|
if (sock != -1)
|
2000-02-24 14:29:47 +00:00
|
|
|
break; /* Successful connection. */
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Return failure if we didn't get a successful connection. */
|
2006-09-30 13:38:06 +00:00
|
|
|
if (sock == -1) {
|
2005-06-05 15:46:09 +00:00
|
|
|
error("ssh: connect to host %s port %s: %s",
|
2002-10-29 10:16:02 +00:00
|
|
|
host, strport, strerror(errno));
|
2005-06-05 15:46:09 +00:00
|
|
|
return (-1);
|
2002-10-29 10:16:02 +00:00
|
|
|
}
|
2000-02-24 14:29:47 +00:00
|
|
|
|
|
|
|
debug("Connection established.");
|
|
|
|
|
2004-02-26 10:52:33 +00:00
|
|
|
/* Set SO_KEEPALIVE if requested. */
|
2008-07-23 09:28:49 +00:00
|
|
|
if (want_keepalive &&
|
2001-05-04 04:14:23 +00:00
|
|
|
setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on,
|
|
|
|
sizeof(on)) < 0)
|
|
|
|
error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
|
2000-02-24 14:29:47 +00:00
|
|
|
|
|
|
|
/* Set the connection. */
|
|
|
|
packet_set_connection(sock, sock);
|
|
|
|
|
2002-03-18 10:09:43 +00:00
|
|
|
return 0;
|
2000-02-24 14:29:47 +00:00
|
|
|
}
|
|
|
|
|
2014-01-30 10:56:49 +00:00
|
|
|
int
|
|
|
|
ssh_connect(const char *host, struct addrinfo *addrs,
|
|
|
|
struct sockaddr_storage *hostaddr, u_short port, int family,
|
|
|
|
int connection_attempts, int *timeout_ms, int want_keepalive, int needpriv)
|
|
|
|
{
|
|
|
|
if (options.proxy_command == NULL) {
|
|
|
|
return ssh_connect_direct(host, addrs, hostaddr, port, family,
|
|
|
|
connection_attempts, timeout_ms, want_keepalive, needpriv);
|
|
|
|
} else if (strcmp(options.proxy_command, "-") == 0) {
|
|
|
|
packet_set_connection(STDIN_FILENO, STDOUT_FILENO);
|
|
|
|
return 0; /* Always succeeds */
|
|
|
|
} else if (options.proxy_use_fdpass) {
|
|
|
|
return ssh_proxy_fdpass_connect(host, port,
|
|
|
|
options.proxy_command);
|
|
|
|
}
|
|
|
|
return ssh_proxy_connect(host, port, options.proxy_command);
|
|
|
|
}
|
|
|
|
|
2013-03-22 11:19:48 +00:00
|
|
|
static void
|
|
|
|
send_client_banner(int connection_out, int minor1)
|
|
|
|
{
|
|
|
|
/* Send our own protocol version identification. */
|
2013-03-22 17:55:38 +00:00
|
|
|
xasprintf(&client_version_string, "SSH-%d.%d-%.100s%s%s%s%s",
|
|
|
|
compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
|
|
|
|
compat20 ? PROTOCOL_MINOR_2 : minor1,
|
|
|
|
SSH_VERSION, options.hpn_disabled ? "" : SSH_VERSION_HPN,
|
|
|
|
*options.version_addendum == '\0' ? "" : " ",
|
|
|
|
options.version_addendum, compat20 ? "\r\n" : "\n");
|
2013-03-22 11:19:48 +00:00
|
|
|
if (roaming_atomicio(vwrite, connection_out, client_version_string,
|
|
|
|
strlen(client_version_string)) != strlen(client_version_string))
|
|
|
|
fatal("write: %.100s", strerror(errno));
|
|
|
|
chop(client_version_string);
|
|
|
|
debug("Local version string %.100s", client_version_string);
|
|
|
|
}
|
|
|
|
|
2000-02-24 14:29:47 +00:00
|
|
|
/*
|
2000-05-15 05:24:25 +00:00
|
|
|
* Waits for the server identification string, and sends our own
|
|
|
|
* identification string.
|
2000-02-24 14:29:47 +00:00
|
|
|
*/
|
2009-10-01 15:19:37 +00:00
|
|
|
void
|
2008-07-23 09:28:49 +00:00
|
|
|
ssh_exchange_identification(int timeout_ms)
|
2000-02-24 14:29:47 +00:00
|
|
|
{
|
2000-05-15 05:24:25 +00:00
|
|
|
char buf[256], remote_version[256]; /* must be same size! */
|
2005-09-03 07:04:25 +00:00
|
|
|
int remote_major, remote_minor, mismatch;
|
2000-05-15 05:24:25 +00:00
|
|
|
int connection_in = packet_get_connection_in();
|
|
|
|
int connection_out = packet_get_connection_out();
|
2013-03-22 11:19:48 +00:00
|
|
|
int minor1 = PROTOCOL_MINOR_1, client_banner_sent = 0;
|
2006-09-30 13:38:06 +00:00
|
|
|
u_int i, n;
|
2008-07-23 09:28:49 +00:00
|
|
|
size_t len;
|
|
|
|
int fdsetsz, remaining, rc;
|
|
|
|
struct timeval t_start, t_remaining;
|
|
|
|
fd_set *fdset;
|
|
|
|
|
|
|
|
fdsetsz = howmany(connection_in + 1, NFDBITS) * sizeof(fd_mask);
|
|
|
|
fdset = xcalloc(1, fdsetsz);
|
2000-02-24 14:29:47 +00:00
|
|
|
|
2013-03-22 11:19:48 +00:00
|
|
|
/*
|
|
|
|
* If we are SSH2-only then we can send the banner immediately and
|
|
|
|
* save a round-trip.
|
|
|
|
*/
|
|
|
|
if (options.protocol == SSH_PROTO_2) {
|
|
|
|
enable_compat20();
|
|
|
|
send_client_banner(connection_out, 0);
|
|
|
|
client_banner_sent = 1;
|
|
|
|
}
|
|
|
|
|
2005-09-03 07:04:25 +00:00
|
|
|
/* Read other side's version identification. */
|
2008-07-23 09:28:49 +00:00
|
|
|
remaining = timeout_ms;
|
2006-09-30 13:38:06 +00:00
|
|
|
for (n = 0;;) {
|
2000-09-10 09:35:38 +00:00
|
|
|
for (i = 0; i < sizeof(buf) - 1; i++) {
|
2008-07-23 09:28:49 +00:00
|
|
|
if (timeout_ms > 0) {
|
|
|
|
gettimeofday(&t_start, NULL);
|
|
|
|
ms_to_timeval(&t_remaining, remaining);
|
|
|
|
FD_SET(connection_in, fdset);
|
|
|
|
rc = select(connection_in + 1, fdset, NULL,
|
|
|
|
fdset, &t_remaining);
|
|
|
|
ms_subtract_diff(&t_start, &remaining);
|
|
|
|
if (rc == 0 || remaining <= 0)
|
|
|
|
fatal("Connection timed out during "
|
|
|
|
"banner exchange");
|
|
|
|
if (rc == -1) {
|
|
|
|
if (errno == EINTR)
|
|
|
|
continue;
|
|
|
|
fatal("ssh_exchange_identification: "
|
|
|
|
"select: %s", strerror(errno));
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2009-10-01 15:19:37 +00:00
|
|
|
len = roaming_atomicio(read, connection_in, &buf[i], 1);
|
2005-09-03 07:04:25 +00:00
|
|
|
|
|
|
|
if (len != 1 && errno == EPIPE)
|
2008-07-23 09:28:49 +00:00
|
|
|
fatal("ssh_exchange_identification: "
|
|
|
|
"Connection closed by remote host");
|
2005-09-03 07:04:25 +00:00
|
|
|
else if (len != 1)
|
2008-07-23 09:28:49 +00:00
|
|
|
fatal("ssh_exchange_identification: "
|
|
|
|
"read: %.100s", strerror(errno));
|
2000-09-10 09:35:38 +00:00
|
|
|
if (buf[i] == '\r') {
|
|
|
|
buf[i] = '\n';
|
|
|
|
buf[i + 1] = 0;
|
|
|
|
continue; /**XXX wait for \n */
|
|
|
|
}
|
|
|
|
if (buf[i] == '\n') {
|
|
|
|
buf[i + 1] = 0;
|
|
|
|
break;
|
|
|
|
}
|
2006-09-30 13:38:06 +00:00
|
|
|
if (++n > 65536)
|
2008-07-23 09:28:49 +00:00
|
|
|
fatal("ssh_exchange_identification: "
|
|
|
|
"No banner received");
|
2000-05-15 05:24:25 +00:00
|
|
|
}
|
2000-09-10 09:35:38 +00:00
|
|
|
buf[sizeof(buf) - 1] = 0;
|
|
|
|
if (strncmp(buf, "SSH-", 4) == 0)
|
2000-05-15 05:24:25 +00:00
|
|
|
break;
|
2000-09-10 09:35:38 +00:00
|
|
|
debug("ssh_exchange_identification: %s", buf);
|
2000-02-24 14:29:47 +00:00
|
|
|
}
|
2000-05-15 05:24:25 +00:00
|
|
|
server_version_string = xstrdup(buf);
|
2013-09-18 17:27:38 +00:00
|
|
|
free(fdset);
|
2000-02-24 14:29:47 +00:00
|
|
|
|
|
|
|
/*
|
2000-05-15 05:24:25 +00:00
|
|
|
* Check that the versions match. In future this might accept
|
|
|
|
* several versions and set appropriate flags to handle them.
|
2000-02-24 14:29:47 +00:00
|
|
|
*/
|
2000-05-15 05:24:25 +00:00
|
|
|
if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n",
|
|
|
|
&remote_major, &remote_minor, remote_version) != 3)
|
|
|
|
fatal("Bad remote protocol version identification: '%.100s'", buf);
|
|
|
|
debug("Remote protocol version %d.%d, remote software version %.100s",
|
2002-03-18 10:09:43 +00:00
|
|
|
remote_major, remote_minor, remote_version);
|
2000-02-24 14:29:47 +00:00
|
|
|
|
2000-05-15 05:24:25 +00:00
|
|
|
compat_datafellows(remote_version);
|
|
|
|
mismatch = 0;
|
2000-02-24 14:29:47 +00:00
|
|
|
|
2002-03-18 10:09:43 +00:00
|
|
|
switch (remote_major) {
|
2000-05-15 05:24:25 +00:00
|
|
|
case 1:
|
|
|
|
if (remote_minor == 99 &&
|
|
|
|
(options.protocol & SSH_PROTO_2) &&
|
|
|
|
!(options.protocol & SSH_PROTO_1_PREFERRED)) {
|
|
|
|
enable_compat20();
|
|
|
|
break;
|
2000-02-24 14:29:47 +00:00
|
|
|
}
|
2000-05-15 05:24:25 +00:00
|
|
|
if (!(options.protocol & SSH_PROTO_1)) {
|
|
|
|
mismatch = 1;
|
|
|
|
break;
|
2000-02-24 14:29:47 +00:00
|
|
|
}
|
2000-05-15 05:24:25 +00:00
|
|
|
if (remote_minor < 3) {
|
|
|
|
fatal("Remote machine has too old SSH software version.");
|
2001-05-04 04:14:23 +00:00
|
|
|
} else if (remote_minor == 3 || remote_minor == 4) {
|
2000-05-15 05:24:25 +00:00
|
|
|
/* We speak 1.3, too. */
|
|
|
|
enable_compat13();
|
2001-05-04 04:14:23 +00:00
|
|
|
minor1 = 3;
|
2000-05-15 05:24:25 +00:00
|
|
|
if (options.forward_agent) {
|
2004-01-07 11:16:27 +00:00
|
|
|
logit("Agent forwarding disabled for protocol 1.3");
|
2000-05-15 05:24:25 +00:00
|
|
|
options.forward_agent = 0;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
case 2:
|
|
|
|
if (options.protocol & SSH_PROTO_2) {
|
|
|
|
enable_compat20();
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
/* FALLTHROUGH */
|
|
|
|
default:
|
|
|
|
mismatch = 1;
|
|
|
|
break;
|
2000-02-24 14:29:47 +00:00
|
|
|
}
|
2000-05-15 05:24:25 +00:00
|
|
|
if (mismatch)
|
|
|
|
fatal("Protocol major versions differ: %d vs. %d",
|
|
|
|
(options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
|
|
|
|
remote_major);
|
2014-01-30 10:56:49 +00:00
|
|
|
if ((datafellows & SSH_BUG_DERIVEKEY) != 0)
|
|
|
|
fatal("Server version \"%.100s\" uses unsafe key agreement; "
|
|
|
|
"refusing connection", remote_version);
|
|
|
|
if ((datafellows & SSH_BUG_RSASIGMD5) != 0)
|
|
|
|
logit("Server version \"%.100s\" uses unsafe RSA signature "
|
|
|
|
"scheme; disabling use of RSA keys", remote_version);
|
2013-03-22 11:19:48 +00:00
|
|
|
if (!client_banner_sent)
|
|
|
|
send_client_banner(connection_out, minor1);
|
2000-05-15 05:24:25 +00:00
|
|
|
chop(server_version_string);
|
2000-02-24 14:29:47 +00:00
|
|
|
}
|
|
|
|
|
2001-05-04 04:14:23 +00:00
|
|
|
/* defaults to 'no' */
|
2002-03-18 10:09:43 +00:00
|
|
|
static int
|
|
|
|
confirm(const char *prompt)
|
2000-02-24 14:29:47 +00:00
|
|
|
{
|
2002-03-18 10:09:43 +00:00
|
|
|
const char *msg, *again = "Please type 'yes' or 'no': ";
|
|
|
|
char *p;
|
|
|
|
int ret = -1;
|
2000-02-24 14:29:47 +00:00
|
|
|
|
2001-05-04 04:14:23 +00:00
|
|
|
if (options.batch_mode)
|
|
|
|
return 0;
|
2002-03-18 10:09:43 +00:00
|
|
|
for (msg = prompt;;msg = again) {
|
|
|
|
p = read_passphrase(msg, RP_ECHO);
|
|
|
|
if (p == NULL ||
|
|
|
|
(p[0] == '\0') || (p[0] == '\n') ||
|
|
|
|
strncasecmp(p, "no", 2) == 0)
|
|
|
|
ret = 0;
|
2002-10-29 10:16:02 +00:00
|
|
|
if (p && strncasecmp(p, "yes", 3) == 0)
|
2002-03-18 10:09:43 +00:00
|
|
|
ret = 1;
|
2013-09-18 17:27:38 +00:00
|
|
|
free(p);
|
2002-03-18 10:09:43 +00:00
|
|
|
if (ret != -1)
|
|
|
|
return ret;
|
2000-02-24 14:29:47 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2010-03-08 11:19:52 +00:00
|
|
|
static int
|
|
|
|
check_host_cert(const char *host, const Key *host_key)
|
|
|
|
{
|
|
|
|
const char *reason;
|
|
|
|
|
|
|
|
if (key_cert_check_authority(host_key, 1, 0, host, &reason) != 0) {
|
|
|
|
error("%s", reason);
|
|
|
|
return 0;
|
|
|
|
}
|
2010-11-08 10:45:44 +00:00
|
|
|
if (buffer_len(&host_key->cert->critical) != 0) {
|
|
|
|
error("Certificate for %s contains unsupported "
|
|
|
|
"critical options(s)", host);
|
2010-03-08 11:19:52 +00:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
2011-02-17 11:47:40 +00:00
|
|
|
static int
|
|
|
|
sockaddr_is_local(struct sockaddr *hostaddr)
|
|
|
|
{
|
|
|
|
switch (hostaddr->sa_family) {
|
|
|
|
case AF_INET:
|
|
|
|
return (ntohl(((struct sockaddr_in *)hostaddr)->
|
|
|
|
sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
|
|
|
|
case AF_INET6:
|
|
|
|
return IN6_IS_ADDR_LOOPBACK(
|
|
|
|
&(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
|
|
|
|
default:
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Prepare the hostname and ip address strings that are used to lookup
|
|
|
|
* host keys in known_hosts files. These may have a port number appended.
|
|
|
|
*/
|
|
|
|
void
|
|
|
|
get_hostfile_hostname_ipaddr(char *hostname, struct sockaddr *hostaddr,
|
|
|
|
u_short port, char **hostfile_hostname, char **hostfile_ipaddr)
|
|
|
|
{
|
|
|
|
char ntop[NI_MAXHOST];
|
|
|
|
socklen_t addrlen;
|
|
|
|
|
|
|
|
switch (hostaddr == NULL ? -1 : hostaddr->sa_family) {
|
|
|
|
case -1:
|
|
|
|
addrlen = 0;
|
|
|
|
break;
|
|
|
|
case AF_INET:
|
|
|
|
addrlen = sizeof(struct sockaddr_in);
|
|
|
|
break;
|
|
|
|
case AF_INET6:
|
|
|
|
addrlen = sizeof(struct sockaddr_in6);
|
|
|
|
break;
|
|
|
|
default:
|
|
|
|
addrlen = sizeof(struct sockaddr);
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* We don't have the remote ip-address for connections
|
|
|
|
* using a proxy command
|
|
|
|
*/
|
|
|
|
if (hostfile_ipaddr != NULL) {
|
|
|
|
if (options.proxy_command == NULL) {
|
|
|
|
if (getnameinfo(hostaddr, addrlen,
|
|
|
|
ntop, sizeof(ntop), NULL, 0, NI_NUMERICHOST) != 0)
|
|
|
|
fatal("check_host_key: getnameinfo failed");
|
|
|
|
*hostfile_ipaddr = put_host_port(ntop, port);
|
|
|
|
} else {
|
|
|
|
*hostfile_ipaddr = xstrdup("<no hostip for proxy "
|
|
|
|
"command>");
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Allow the user to record the key under a different name or
|
|
|
|
* differentiate a non-standard port. This is useful for ssh
|
|
|
|
* tunneling over forwarded connections or if you run multiple
|
|
|
|
* sshd's on different ports on the same machine.
|
|
|
|
*/
|
|
|
|
if (hostfile_hostname != NULL) {
|
|
|
|
if (options.host_key_alias != NULL) {
|
|
|
|
*hostfile_hostname = xstrdup(options.host_key_alias);
|
|
|
|
debug("using hostkeyalias: %s", *hostfile_hostname);
|
|
|
|
} else {
|
|
|
|
*hostfile_hostname = put_host_port(hostname, port);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2000-05-15 05:24:25 +00:00
|
|
|
/*
|
2002-03-18 10:09:43 +00:00
|
|
|
* check whether the supplied host key is valid, return -1 if the key
|
2011-09-28 08:14:41 +00:00
|
|
|
* is not valid. user_hostfile[0] will not be updated if 'readonly' is true.
|
2000-05-15 05:24:25 +00:00
|
|
|
*/
|
2006-09-30 13:38:06 +00:00
|
|
|
#define RDRW 0
|
|
|
|
#define RDONLY 1
|
|
|
|
#define ROQUIET 2
|
2002-03-18 10:09:43 +00:00
|
|
|
static int
|
2006-09-30 13:38:06 +00:00
|
|
|
check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
|
2011-09-28 08:14:41 +00:00
|
|
|
Key *host_key, int readonly,
|
|
|
|
char **user_hostfiles, u_int num_user_hostfiles,
|
|
|
|
char **system_hostfiles, u_int num_system_hostfiles)
|
2000-05-15 05:24:25 +00:00
|
|
|
{
|
2011-09-28 08:14:41 +00:00
|
|
|
HostStatus host_status;
|
|
|
|
HostStatus ip_status;
|
2011-02-17 11:47:40 +00:00
|
|
|
Key *raw_key = NULL;
|
2006-09-30 13:38:06 +00:00
|
|
|
char *ip = NULL, *host = NULL;
|
2008-07-23 09:33:08 +00:00
|
|
|
char hostline[1000], *hostp, *fp, *ra;
|
2002-03-18 10:09:43 +00:00
|
|
|
char msg[1024];
|
2011-09-28 08:14:41 +00:00
|
|
|
const char *type;
|
|
|
|
const struct hostkey_entry *host_found, *ip_found;
|
2011-02-17 11:47:40 +00:00
|
|
|
int len, cancelled_forwarding = 0;
|
2011-09-28 08:14:41 +00:00
|
|
|
int local = sockaddr_is_local(hostaddr);
|
|
|
|
int r, want_cert = key_is_cert(host_key), host_ip_differ = 0;
|
2011-02-17 11:47:40 +00:00
|
|
|
struct hostkeys *host_hostkeys, *ip_hostkeys;
|
2011-09-28 08:14:41 +00:00
|
|
|
u_int i;
|
2000-02-24 14:29:47 +00:00
|
|
|
|
2000-05-15 05:24:25 +00:00
|
|
|
/*
|
|
|
|
* Force accepting of the host key for loopback/localhost. The
|
|
|
|
* problem is that if the home directory is NFS-mounted to multiple
|
|
|
|
* machines, localhost will refer to a different machine in each of
|
|
|
|
* them, and the user will get bogus HOST_CHANGED warnings. This
|
|
|
|
* essentially disables host authentication for localhost; however,
|
|
|
|
* this is probably not a real problem.
|
|
|
|
*/
|
2002-03-18 10:09:43 +00:00
|
|
|
if (options.no_host_authentication_for_localhost == 1 && local &&
|
|
|
|
options.host_key_alias == NULL) {
|
2001-05-04 04:14:23 +00:00
|
|
|
debug("Forcing accepting of host key for "
|
|
|
|
"loopback/localhost.");
|
2002-03-18 10:09:43 +00:00
|
|
|
return 0;
|
2000-02-24 14:29:47 +00:00
|
|
|
}
|
|
|
|
|
2000-05-15 05:24:25 +00:00
|
|
|
/*
|
2011-02-17 11:47:40 +00:00
|
|
|
* Prepare the hostname and address strings used for hostkey lookup.
|
|
|
|
* In some cases, these will have a port number appended.
|
2000-05-15 05:24:25 +00:00
|
|
|
*/
|
2011-02-17 11:47:40 +00:00
|
|
|
get_hostfile_hostname_ipaddr(hostname, hostaddr, port, &host, &ip);
|
2008-07-23 09:33:08 +00:00
|
|
|
|
2001-05-04 04:14:23 +00:00
|
|
|
/*
|
|
|
|
* Turn off check_host_ip if the connection is to localhost, via proxy
|
|
|
|
* command or if we don't have a hostname to compare with
|
|
|
|
*/
|
2006-09-30 13:38:06 +00:00
|
|
|
if (options.check_host_ip && (local ||
|
|
|
|
strcmp(hostname, ip) == 0 || options.proxy_command != NULL))
|
2001-05-04 04:14:23 +00:00
|
|
|
options.check_host_ip = 0;
|
|
|
|
|
2011-02-17 11:47:40 +00:00
|
|
|
host_hostkeys = init_hostkeys();
|
2011-09-28 08:14:41 +00:00
|
|
|
for (i = 0; i < num_user_hostfiles; i++)
|
|
|
|
load_hostkeys(host_hostkeys, host, user_hostfiles[i]);
|
|
|
|
for (i = 0; i < num_system_hostfiles; i++)
|
|
|
|
load_hostkeys(host_hostkeys, host, system_hostfiles[i]);
|
2011-02-17 11:47:40 +00:00
|
|
|
|
|
|
|
ip_hostkeys = NULL;
|
|
|
|
if (!want_cert && options.check_host_ip) {
|
|
|
|
ip_hostkeys = init_hostkeys();
|
2011-09-28 08:14:41 +00:00
|
|
|
for (i = 0; i < num_user_hostfiles; i++)
|
|
|
|
load_hostkeys(ip_hostkeys, ip, user_hostfiles[i]);
|
|
|
|
for (i = 0; i < num_system_hostfiles; i++)
|
|
|
|
load_hostkeys(ip_hostkeys, ip, system_hostfiles[i]);
|
2000-02-24 14:29:47 +00:00
|
|
|
}
|
|
|
|
|
2010-03-08 11:19:52 +00:00
|
|
|
retry:
|
2011-02-17 11:47:40 +00:00
|
|
|
/* Reload these as they may have changed on cert->key downgrade */
|
2010-03-08 11:19:52 +00:00
|
|
|
want_cert = key_is_cert(host_key);
|
|
|
|
type = key_type(host_key);
|
|
|
|
|
2000-05-15 05:24:25 +00:00
|
|
|
/*
|
2006-03-22 20:41:37 +00:00
|
|
|
* Check if the host key is present in the user's list of known
|
2000-05-15 05:24:25 +00:00
|
|
|
* hosts or in the systemwide list.
|
|
|
|
*/
|
2011-02-17 11:47:40 +00:00
|
|
|
host_status = check_key_in_hostkeys(host_hostkeys, host_key,
|
|
|
|
&host_found);
|
|
|
|
|
2000-05-15 05:24:25 +00:00
|
|
|
/*
|
|
|
|
* Also perform check for the ip address, skip the check if we are
|
2010-03-08 11:19:52 +00:00
|
|
|
* localhost, looking for a certificate, or the hostname was an ip
|
|
|
|
* address to begin with.
|
2000-05-15 05:24:25 +00:00
|
|
|
*/
|
2011-02-17 11:47:40 +00:00
|
|
|
if (!want_cert && ip_hostkeys != NULL) {
|
|
|
|
ip_status = check_key_in_hostkeys(ip_hostkeys, host_key,
|
|
|
|
&ip_found);
|
2000-05-15 05:24:25 +00:00
|
|
|
if (host_status == HOST_CHANGED &&
|
2011-02-17 11:47:40 +00:00
|
|
|
(ip_status != HOST_CHANGED ||
|
|
|
|
(ip_found != NULL &&
|
|
|
|
!key_equal(ip_found->key, host_found->key))))
|
2000-05-15 05:24:25 +00:00
|
|
|
host_ip_differ = 1;
|
|
|
|
} else
|
|
|
|
ip_status = host_status;
|
2000-02-24 14:29:47 +00:00
|
|
|
|
2000-05-15 05:24:25 +00:00
|
|
|
switch (host_status) {
|
|
|
|
case HOST_OK:
|
|
|
|
/* The host is known and the key matches. */
|
2010-03-08 11:19:52 +00:00
|
|
|
debug("Host '%.200s' is known and matches the %s host %s.",
|
|
|
|
host, type, want_cert ? "certificate" : "key");
|
2011-02-17 11:47:40 +00:00
|
|
|
debug("Found %s in %s:%lu", want_cert ? "CA key" : "key",
|
|
|
|
host_found->file, host_found->line);
|
2010-03-08 11:19:52 +00:00
|
|
|
if (want_cert && !check_host_cert(hostname, host_key))
|
|
|
|
goto fail;
|
2001-05-04 04:14:23 +00:00
|
|
|
if (options.check_host_ip && ip_status == HOST_NEW) {
|
2010-03-08 11:19:52 +00:00
|
|
|
if (readonly || want_cert)
|
2004-01-07 11:16:27 +00:00
|
|
|
logit("%s host key for IP address "
|
2002-03-18 10:09:43 +00:00
|
|
|
"'%.128s' not in list of known hosts.",
|
2001-05-04 04:14:23 +00:00
|
|
|
type, ip);
|
2011-09-28 08:14:41 +00:00
|
|
|
else if (!add_host_to_hostfile(user_hostfiles[0], ip,
|
2005-06-05 15:46:09 +00:00
|
|
|
host_key, options.hash_known_hosts))
|
2004-01-07 11:16:27 +00:00
|
|
|
logit("Failed to add the %s host key for IP "
|
2002-03-18 10:09:43 +00:00
|
|
|
"address '%.128s' to the list of known "
|
2011-09-28 08:14:41 +00:00
|
|
|
"hosts (%.30s).", type, ip,
|
|
|
|
user_hostfiles[0]);
|
2002-03-18 10:09:43 +00:00
|
|
|
else
|
2004-01-07 11:16:27 +00:00
|
|
|
logit("Warning: Permanently added the %s host "
|
2002-03-18 10:09:43 +00:00
|
|
|
"key for IP address '%.128s' to the list "
|
|
|
|
"of known hosts.", type, ip);
|
2008-07-23 09:33:08 +00:00
|
|
|
} else if (options.visual_host_key) {
|
|
|
|
fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
|
|
|
|
ra = key_fingerprint(host_key, SSH_FP_MD5,
|
|
|
|
SSH_FP_RANDOMART);
|
|
|
|
logit("Host key fingerprint is %s\n%s\n", fp, ra);
|
2013-09-18 17:27:38 +00:00
|
|
|
free(ra);
|
|
|
|
free(fp);
|
2000-05-15 05:24:25 +00:00
|
|
|
}
|
|
|
|
break;
|
|
|
|
case HOST_NEW:
|
2006-09-30 13:38:06 +00:00
|
|
|
if (options.host_key_alias == NULL && port != 0 &&
|
|
|
|
port != SSH_DEFAULT_PORT) {
|
|
|
|
debug("checking without port identifier");
|
2009-02-24 18:49:27 +00:00
|
|
|
if (check_host_key(hostname, hostaddr, 0, host_key,
|
2011-09-28 08:14:41 +00:00
|
|
|
ROQUIET, user_hostfiles, num_user_hostfiles,
|
|
|
|
system_hostfiles, num_system_hostfiles) == 0) {
|
2006-09-30 13:38:06 +00:00
|
|
|
debug("found matching key w/out port");
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
2010-03-08 11:19:52 +00:00
|
|
|
if (readonly || want_cert)
|
2002-03-18 10:09:43 +00:00
|
|
|
goto fail;
|
2000-05-15 05:24:25 +00:00
|
|
|
/* The host is new. */
|
|
|
|
if (options.strict_host_key_checking == 1) {
|
2002-03-18 10:09:43 +00:00
|
|
|
/*
|
|
|
|
* User has requested strict host key checking. We
|
|
|
|
* will not add the host key automatically. The only
|
|
|
|
* alternative left is to abort.
|
|
|
|
*/
|
|
|
|
error("No %s host key is known for %.200s and you "
|
|
|
|
"have requested strict checking.", type, host);
|
|
|
|
goto fail;
|
2000-05-15 05:24:25 +00:00
|
|
|
} else if (options.strict_host_key_checking == 2) {
|
2004-01-07 11:16:27 +00:00
|
|
|
char msg1[1024], msg2[1024];
|
|
|
|
|
2011-02-17 11:47:40 +00:00
|
|
|
if (show_other_keys(host_hostkeys, host_key))
|
2004-01-07 11:16:27 +00:00
|
|
|
snprintf(msg1, sizeof(msg1),
|
2005-09-03 07:04:25 +00:00
|
|
|
"\nbut keys of different type are already"
|
|
|
|
" known for this host.");
|
2004-01-07 11:16:27 +00:00
|
|
|
else
|
|
|
|
snprintf(msg1, sizeof(msg1), ".");
|
2000-05-15 05:24:25 +00:00
|
|
|
/* The default */
|
2001-05-04 04:14:23 +00:00
|
|
|
fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
|
2008-07-23 09:33:08 +00:00
|
|
|
ra = key_fingerprint(host_key, SSH_FP_MD5,
|
|
|
|
SSH_FP_RANDOMART);
|
2004-01-07 11:16:27 +00:00
|
|
|
msg2[0] = '\0';
|
|
|
|
if (options.verify_host_key_dns) {
|
2004-02-26 10:52:33 +00:00
|
|
|
if (matching_host_key_dns)
|
2004-01-07 11:16:27 +00:00
|
|
|
snprintf(msg2, sizeof(msg2),
|
|
|
|
"Matching host key fingerprint"
|
|
|
|
" found in DNS.\n");
|
|
|
|
else
|
|
|
|
snprintf(msg2, sizeof(msg2),
|
|
|
|
"No matching host key fingerprint"
|
|
|
|
" found in DNS.\n");
|
|
|
|
}
|
2002-03-18 10:09:43 +00:00
|
|
|
snprintf(msg, sizeof(msg),
|
|
|
|
"The authenticity of host '%.200s (%s)' can't be "
|
2002-10-29 10:16:02 +00:00
|
|
|
"established%s\n"
|
2008-07-23 09:33:08 +00:00
|
|
|
"%s key fingerprint is %s.%s%s\n%s"
|
2002-03-18 10:09:43 +00:00
|
|
|
"Are you sure you want to continue connecting "
|
2002-10-29 10:16:02 +00:00
|
|
|
"(yes/no)? ",
|
2008-07-23 09:33:08 +00:00
|
|
|
host, ip, msg1, type, fp,
|
|
|
|
options.visual_host_key ? "\n" : "",
|
|
|
|
options.visual_host_key ? ra : "",
|
|
|
|
msg2);
|
2013-09-18 17:27:38 +00:00
|
|
|
free(ra);
|
|
|
|
free(fp);
|
2002-03-18 10:09:43 +00:00
|
|
|
if (!confirm(msg))
|
|
|
|
goto fail;
|
2000-05-15 05:24:25 +00:00
|
|
|
}
|
2002-03-18 10:09:43 +00:00
|
|
|
/*
|
|
|
|
* If not in strict mode, add the key automatically to the
|
|
|
|
* local known_hosts file.
|
|
|
|
*/
|
2005-06-05 15:46:09 +00:00
|
|
|
if (options.check_host_ip && ip_status == HOST_NEW) {
|
2011-02-17 11:47:40 +00:00
|
|
|
snprintf(hostline, sizeof(hostline), "%s,%s", host, ip);
|
2005-06-05 15:46:09 +00:00
|
|
|
hostp = hostline;
|
|
|
|
if (options.hash_known_hosts) {
|
|
|
|
/* Add hash of host and IP separately */
|
2011-09-28 08:14:41 +00:00
|
|
|
r = add_host_to_hostfile(user_hostfiles[0],
|
|
|
|
host, host_key, options.hash_known_hosts) &&
|
|
|
|
add_host_to_hostfile(user_hostfiles[0], ip,
|
2005-06-05 15:46:09 +00:00
|
|
|
host_key, options.hash_known_hosts);
|
|
|
|
} else {
|
|
|
|
/* Add unhashed "host,ip" */
|
2011-09-28 08:14:41 +00:00
|
|
|
r = add_host_to_hostfile(user_hostfiles[0],
|
2005-06-05 15:46:09 +00:00
|
|
|
hostline, host_key,
|
|
|
|
options.hash_known_hosts);
|
|
|
|
}
|
|
|
|
} else {
|
2011-09-28 08:14:41 +00:00
|
|
|
r = add_host_to_hostfile(user_hostfiles[0], host,
|
|
|
|
host_key, options.hash_known_hosts);
|
2005-06-05 15:46:09 +00:00
|
|
|
hostp = host;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (!r)
|
2004-01-07 11:16:27 +00:00
|
|
|
logit("Failed to add the host to the list of known "
|
2011-09-28 08:14:41 +00:00
|
|
|
"hosts (%.500s).", user_hostfiles[0]);
|
2000-05-15 05:24:25 +00:00
|
|
|
else
|
2004-01-07 11:16:27 +00:00
|
|
|
logit("Warning: Permanently added '%.200s' (%s) to the "
|
2002-03-18 10:09:43 +00:00
|
|
|
"list of known hosts.", hostp, type);
|
2000-05-15 05:24:25 +00:00
|
|
|
break;
|
2010-03-08 11:19:52 +00:00
|
|
|
case HOST_REVOKED:
|
|
|
|
error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
|
|
|
|
error("@ WARNING: REVOKED HOST KEY DETECTED! @");
|
|
|
|
error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
|
|
|
|
error("The %s host key for %s is marked as revoked.", type, host);
|
|
|
|
error("This could mean that a stolen key is being used to");
|
|
|
|
error("impersonate this host.");
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If strict host key checking is in use, the user will have
|
|
|
|
* to edit the key manually and we can only abort.
|
|
|
|
*/
|
|
|
|
if (options.strict_host_key_checking) {
|
|
|
|
error("%s host key for %.200s was revoked and you have "
|
|
|
|
"requested strict checking.", type, host);
|
|
|
|
goto fail;
|
|
|
|
}
|
|
|
|
goto continue_unsafe;
|
|
|
|
|
2000-05-15 05:24:25 +00:00
|
|
|
case HOST_CHANGED:
|
2010-03-08 11:19:52 +00:00
|
|
|
if (want_cert) {
|
|
|
|
/*
|
|
|
|
* This is only a debug() since it is valid to have
|
|
|
|
* CAs with wildcard DNS matches that don't match
|
|
|
|
* all hosts that one might visit.
|
|
|
|
*/
|
|
|
|
debug("Host certificate authority does not "
|
2011-02-17 11:47:40 +00:00
|
|
|
"match %s in %s:%lu", CA_MARKER,
|
|
|
|
host_found->file, host_found->line);
|
2010-03-08 11:19:52 +00:00
|
|
|
goto fail;
|
|
|
|
}
|
2006-09-30 13:38:06 +00:00
|
|
|
if (readonly == ROQUIET)
|
|
|
|
goto fail;
|
2000-05-15 05:24:25 +00:00
|
|
|
if (options.check_host_ip && host_ip_differ) {
|
2004-10-28 16:11:31 +00:00
|
|
|
char *key_msg;
|
2000-05-15 05:24:25 +00:00
|
|
|
if (ip_status == HOST_NEW)
|
2004-10-28 16:11:31 +00:00
|
|
|
key_msg = "is unknown";
|
2000-05-15 05:24:25 +00:00
|
|
|
else if (ip_status == HOST_OK)
|
2004-10-28 16:11:31 +00:00
|
|
|
key_msg = "is unchanged";
|
2000-05-15 05:24:25 +00:00
|
|
|
else
|
2004-10-28 16:11:31 +00:00
|
|
|
key_msg = "has a different value";
|
2000-05-15 05:24:25 +00:00
|
|
|
error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
|
|
|
|
error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @");
|
|
|
|
error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
|
|
|
|
error("The %s host key for %s has changed,", type, host);
|
2008-07-23 09:33:08 +00:00
|
|
|
error("and the key for the corresponding IP address %s", ip);
|
2004-10-28 16:11:31 +00:00
|
|
|
error("%s. This could either mean that", key_msg);
|
2000-05-15 05:24:25 +00:00
|
|
|
error("DNS SPOOFING is happening or the IP address for the host");
|
2001-05-04 04:14:23 +00:00
|
|
|
error("and its host key have changed at the same time.");
|
|
|
|
if (ip_status != HOST_NEW)
|
2011-02-17 11:47:40 +00:00
|
|
|
error("Offending key for IP in %s:%lu",
|
|
|
|
ip_found->file, ip_found->line);
|
2000-05-15 05:24:25 +00:00
|
|
|
}
|
|
|
|
/* The host key has changed. */
|
2004-02-26 10:52:33 +00:00
|
|
|
warn_changed_key(host_key);
|
2000-05-15 05:24:25 +00:00
|
|
|
error("Add correct host key in %.100s to get rid of this message.",
|
2011-09-28 08:14:41 +00:00
|
|
|
user_hostfiles[0]);
|
2011-02-17 11:47:40 +00:00
|
|
|
error("Offending %s key in %s:%lu", key_type(host_found->key),
|
|
|
|
host_found->file, host_found->line);
|
2000-05-15 05:24:25 +00:00
|
|
|
|
|
|
|
/*
|
|
|
|
* If strict host key checking is in use, the user will have
|
|
|
|
* to edit the key manually and we can only abort.
|
|
|
|
*/
|
2002-03-18 10:09:43 +00:00
|
|
|
if (options.strict_host_key_checking) {
|
|
|
|
error("%s host key for %.200s has changed and you have "
|
|
|
|
"requested strict checking.", type, host);
|
|
|
|
goto fail;
|
|
|
|
}
|
2000-05-15 05:24:25 +00:00
|
|
|
|
2010-03-08 11:19:52 +00:00
|
|
|
continue_unsafe:
|
2000-05-15 05:24:25 +00:00
|
|
|
/*
|
|
|
|
* If strict host key checking has not been requested, allow
|
2004-01-07 11:16:27 +00:00
|
|
|
* the connection but without MITM-able authentication or
|
2006-09-30 13:38:06 +00:00
|
|
|
* forwarding.
|
2000-05-15 05:24:25 +00:00
|
|
|
*/
|
|
|
|
if (options.password_authentication) {
|
2002-03-18 10:09:43 +00:00
|
|
|
error("Password authentication is disabled to avoid "
|
|
|
|
"man-in-the-middle attacks.");
|
2000-05-15 05:24:25 +00:00
|
|
|
options.password_authentication = 0;
|
2008-07-23 09:33:08 +00:00
|
|
|
cancelled_forwarding = 1;
|
2000-05-15 05:24:25 +00:00
|
|
|
}
|
2004-01-07 11:16:27 +00:00
|
|
|
if (options.kbd_interactive_authentication) {
|
|
|
|
error("Keyboard-interactive authentication is disabled"
|
|
|
|
" to avoid man-in-the-middle attacks.");
|
|
|
|
options.kbd_interactive_authentication = 0;
|
|
|
|
options.challenge_response_authentication = 0;
|
2008-07-23 09:33:08 +00:00
|
|
|
cancelled_forwarding = 1;
|
2004-01-07 11:16:27 +00:00
|
|
|
}
|
|
|
|
if (options.challenge_response_authentication) {
|
|
|
|
error("Challenge/response authentication is disabled"
|
|
|
|
" to avoid man-in-the-middle attacks.");
|
|
|
|
options.challenge_response_authentication = 0;
|
2008-07-23 09:33:08 +00:00
|
|
|
cancelled_forwarding = 1;
|
2004-01-07 11:16:27 +00:00
|
|
|
}
|
2000-05-15 05:24:25 +00:00
|
|
|
if (options.forward_agent) {
|
2002-03-18 10:09:43 +00:00
|
|
|
error("Agent forwarding is disabled to avoid "
|
|
|
|
"man-in-the-middle attacks.");
|
2000-05-15 05:24:25 +00:00
|
|
|
options.forward_agent = 0;
|
2008-07-23 09:33:08 +00:00
|
|
|
cancelled_forwarding = 1;
|
2000-05-15 05:24:25 +00:00
|
|
|
}
|
2001-05-04 04:14:23 +00:00
|
|
|
if (options.forward_x11) {
|
2002-03-18 10:09:43 +00:00
|
|
|
error("X11 forwarding is disabled to avoid "
|
|
|
|
"man-in-the-middle attacks.");
|
2001-05-04 04:14:23 +00:00
|
|
|
options.forward_x11 = 0;
|
2008-07-23 09:33:08 +00:00
|
|
|
cancelled_forwarding = 1;
|
2001-05-04 04:14:23 +00:00
|
|
|
}
|
2002-03-18 10:09:43 +00:00
|
|
|
if (options.num_local_forwards > 0 ||
|
|
|
|
options.num_remote_forwards > 0) {
|
|
|
|
error("Port forwarding is disabled to avoid "
|
|
|
|
"man-in-the-middle attacks.");
|
|
|
|
options.num_local_forwards =
|
|
|
|
options.num_remote_forwards = 0;
|
2008-07-23 09:33:08 +00:00
|
|
|
cancelled_forwarding = 1;
|
2001-05-04 04:14:23 +00:00
|
|
|
}
|
2006-09-30 13:38:06 +00:00
|
|
|
if (options.tun_open != SSH_TUNMODE_NO) {
|
|
|
|
error("Tunnel forwarding is disabled to avoid "
|
|
|
|
"man-in-the-middle attacks.");
|
|
|
|
options.tun_open = SSH_TUNMODE_NO;
|
2008-07-23 09:33:08 +00:00
|
|
|
cancelled_forwarding = 1;
|
2006-09-30 13:38:06 +00:00
|
|
|
}
|
2008-07-23 09:33:08 +00:00
|
|
|
if (options.exit_on_forward_failure && cancelled_forwarding)
|
|
|
|
fatal("Error: forwarding disabled due to host key "
|
|
|
|
"check failure");
|
|
|
|
|
2000-05-15 05:24:25 +00:00
|
|
|
/*
|
|
|
|
* XXX Should permit the user to change to use the new id.
|
|
|
|
* This could be done by converting the host key to an
|
|
|
|
* identifying sentence, tell that the host identifies itself
|
2010-03-08 11:19:52 +00:00
|
|
|
* by that sentence, and ask the user if he/she wishes to
|
2000-05-15 05:24:25 +00:00
|
|
|
* accept the authentication.
|
|
|
|
*/
|
|
|
|
break;
|
2002-10-29 10:16:02 +00:00
|
|
|
case HOST_FOUND:
|
|
|
|
fatal("internal error");
|
|
|
|
break;
|
2000-05-15 05:24:25 +00:00
|
|
|
}
|
2001-05-04 04:14:23 +00:00
|
|
|
|
|
|
|
if (options.check_host_ip && host_status != HOST_CHANGED &&
|
|
|
|
ip_status == HOST_CHANGED) {
|
2002-03-18 10:09:43 +00:00
|
|
|
snprintf(msg, sizeof(msg),
|
|
|
|
"Warning: the %s host key for '%.200s' "
|
|
|
|
"differs from the key for the IP address '%.128s'"
|
2011-02-17 11:47:40 +00:00
|
|
|
"\nOffending key for IP in %s:%lu",
|
|
|
|
type, host, ip, ip_found->file, ip_found->line);
|
2002-03-18 10:09:43 +00:00
|
|
|
if (host_status == HOST_OK) {
|
|
|
|
len = strlen(msg);
|
|
|
|
snprintf(msg + len, sizeof(msg) - len,
|
2011-02-17 11:47:40 +00:00
|
|
|
"\nMatching host key in %s:%lu",
|
|
|
|
host_found->file, host_found->line);
|
2002-03-18 10:09:43 +00:00
|
|
|
}
|
2001-05-04 04:14:23 +00:00
|
|
|
if (options.strict_host_key_checking == 1) {
|
2004-01-07 11:16:27 +00:00
|
|
|
logit("%s", msg);
|
2002-03-18 10:09:43 +00:00
|
|
|
error("Exiting, you have requested strict checking.");
|
|
|
|
goto fail;
|
2001-05-04 04:14:23 +00:00
|
|
|
} else if (options.strict_host_key_checking == 2) {
|
2002-03-18 10:09:43 +00:00
|
|
|
strlcat(msg, "\nAre you sure you want "
|
|
|
|
"to continue connecting (yes/no)? ", sizeof(msg));
|
|
|
|
if (!confirm(msg))
|
|
|
|
goto fail;
|
|
|
|
} else {
|
2004-01-07 11:16:27 +00:00
|
|
|
logit("%s", msg);
|
2001-05-04 04:14:23 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2013-09-18 17:27:38 +00:00
|
|
|
free(ip);
|
|
|
|
free(host);
|
2011-02-17 11:47:40 +00:00
|
|
|
if (host_hostkeys != NULL)
|
|
|
|
free_hostkeys(host_hostkeys);
|
|
|
|
if (ip_hostkeys != NULL)
|
|
|
|
free_hostkeys(ip_hostkeys);
|
2002-03-18 10:09:43 +00:00
|
|
|
return 0;
|
2000-02-24 14:29:47 +00:00
|
|
|
|
2002-03-18 10:09:43 +00:00
|
|
|
fail:
|
2010-03-08 11:19:52 +00:00
|
|
|
if (want_cert && host_status != HOST_REVOKED) {
|
|
|
|
/*
|
|
|
|
* No matching certificate. Downgrade cert to raw key and
|
|
|
|
* search normally.
|
|
|
|
*/
|
|
|
|
debug("No matching CA found. Retry with plain key");
|
|
|
|
raw_key = key_from_private(host_key);
|
|
|
|
if (key_drop_cert(raw_key) != 0)
|
|
|
|
fatal("Couldn't drop certificate");
|
|
|
|
host_key = raw_key;
|
|
|
|
goto retry;
|
|
|
|
}
|
|
|
|
if (raw_key != NULL)
|
|
|
|
key_free(raw_key);
|
2013-09-18 17:27:38 +00:00
|
|
|
free(ip);
|
|
|
|
free(host);
|
2011-02-17 11:47:40 +00:00
|
|
|
if (host_hostkeys != NULL)
|
|
|
|
free_hostkeys(host_hostkeys);
|
|
|
|
if (ip_hostkeys != NULL)
|
|
|
|
free_hostkeys(ip_hostkeys);
|
2002-03-18 10:09:43 +00:00
|
|
|
return -1;
|
2000-02-28 19:03:50 +00:00
|
|
|
}
|
|
|
|
|
2004-01-07 11:16:27 +00:00
|
|
|
/* returns 0 if key verifies or -1 if key does NOT verify */
|
2002-03-18 10:09:43 +00:00
|
|
|
int
|
|
|
|
verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key)
|
2000-02-28 19:03:50 +00:00
|
|
|
{
|
2004-02-26 10:52:33 +00:00
|
|
|
int flags = 0;
|
2011-02-17 11:47:40 +00:00
|
|
|
char *fp;
|
2015-07-28 19:58:38 +00:00
|
|
|
Key *plain = NULL;
|
2011-02-17 11:47:40 +00:00
|
|
|
|
|
|
|
fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
|
|
|
|
debug("Server host key: %s %s", key_type(host_key), fp);
|
2013-09-18 17:27:38 +00:00
|
|
|
free(fp);
|
2002-03-18 10:09:43 +00:00
|
|
|
|
2015-07-28 19:58:38 +00:00
|
|
|
if (options.verify_host_key_dns) {
|
|
|
|
/*
|
|
|
|
* XXX certs are not yet supported for DNS, so downgrade
|
|
|
|
* them and try the plain key.
|
|
|
|
*/
|
|
|
|
plain = key_from_private(host_key);
|
|
|
|
if (key_is_cert(plain))
|
|
|
|
key_drop_cert(plain);
|
|
|
|
if (verify_host_key_dns(host, hostaddr, plain, &flags) == 0) {
|
|
|
|
if (flags & DNS_VERIFY_FOUND) {
|
|
|
|
if (options.verify_host_key_dns == 1 &&
|
|
|
|
flags & DNS_VERIFY_MATCH &&
|
|
|
|
flags & DNS_VERIFY_SECURE) {
|
|
|
|
key_free(plain);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
if (flags & DNS_VERIFY_MATCH) {
|
|
|
|
matching_host_key_dns = 1;
|
|
|
|
} else {
|
|
|
|
warn_changed_key(plain);
|
|
|
|
error("Update the SSHFP RR in DNS "
|
|
|
|
"with the new host key to get rid "
|
|
|
|
"of this message.");
|
|
|
|
}
|
2004-02-26 10:52:33 +00:00
|
|
|
}
|
2004-01-07 11:16:27 +00:00
|
|
|
}
|
2015-07-28 19:58:38 +00:00
|
|
|
key_free(plain);
|
2004-01-07 11:16:27 +00:00
|
|
|
}
|
|
|
|
|
2011-09-28 08:14:41 +00:00
|
|
|
return check_host_key(host, hostaddr, options.port, host_key, RDRW,
|
|
|
|
options.user_hostfiles, options.num_user_hostfiles,
|
|
|
|
options.system_hostfiles, options.num_system_hostfiles);
|
2000-02-28 19:03:50 +00:00
|
|
|
}
|
|
|
|
|
2000-02-24 14:29:47 +00:00
|
|
|
/*
|
|
|
|
* Starts a dialog with the server, and authenticates the current user on the
|
|
|
|
* server. This does not need any extra privileges. The basic connection
|
|
|
|
* to the server must already have been established before this is called.
|
|
|
|
* If login fails, this function prints an error and never returns.
|
|
|
|
* This function does not require super-user privileges.
|
|
|
|
*/
|
|
|
|
void
|
2002-06-23 16:09:08 +00:00
|
|
|
ssh_login(Sensitive *sensitive, const char *orighost,
|
2011-02-17 11:47:40 +00:00
|
|
|
struct sockaddr *hostaddr, u_short port, struct passwd *pw, int timeout_ms)
|
2000-02-24 14:29:47 +00:00
|
|
|
{
|
2014-01-30 10:56:49 +00:00
|
|
|
char *host;
|
2000-05-15 05:24:25 +00:00
|
|
|
char *server_user, *local_user;
|
|
|
|
|
|
|
|
local_user = xstrdup(pw->pw_name);
|
|
|
|
server_user = options.user ? options.user : local_user;
|
2000-02-24 14:29:47 +00:00
|
|
|
|
|
|
|
/* Convert the user-supplied hostname into all lowercase. */
|
|
|
|
host = xstrdup(orighost);
|
2014-01-30 10:56:49 +00:00
|
|
|
lowercase(host);
|
2000-02-24 14:29:47 +00:00
|
|
|
|
|
|
|
/* Exchange protocol version identification strings with the server. */
|
2008-07-23 09:28:49 +00:00
|
|
|
ssh_exchange_identification(timeout_ms);
|
2000-02-24 14:29:47 +00:00
|
|
|
|
|
|
|
/* Put the connection into non-blocking mode. */
|
|
|
|
packet_set_nonblocking();
|
|
|
|
|
|
|
|
/* key exchange */
|
|
|
|
/* authenticate user */
|
2000-05-15 05:24:25 +00:00
|
|
|
if (compat20) {
|
2011-02-17 11:47:40 +00:00
|
|
|
ssh_kex2(host, hostaddr, port);
|
2002-06-23 16:09:08 +00:00
|
|
|
ssh_userauth2(local_user, server_user, host, sensitive);
|
2000-05-15 05:24:25 +00:00
|
|
|
} else {
|
|
|
|
ssh_kex(host, hostaddr);
|
2002-06-23 16:09:08 +00:00
|
|
|
ssh_userauth1(local_user, server_user, host, sensitive);
|
2000-05-15 05:24:25 +00:00
|
|
|
}
|
2013-09-18 17:27:38 +00:00
|
|
|
free(local_user);
|
2000-02-24 14:29:47 +00:00
|
|
|
}
|
2001-03-20 02:06:40 +00:00
|
|
|
|
|
|
|
void
|
|
|
|
ssh_put_password(char *password)
|
|
|
|
{
|
|
|
|
int size;
|
|
|
|
char *padded;
|
|
|
|
|
2001-05-04 04:14:23 +00:00
|
|
|
if (datafellows & SSH_BUG_PASSWORDPAD) {
|
2002-03-18 10:09:43 +00:00
|
|
|
packet_put_cstring(password);
|
2001-05-04 04:14:23 +00:00
|
|
|
return;
|
|
|
|
}
|
2001-03-20 02:06:40 +00:00
|
|
|
size = roundup(strlen(password) + 1, 32);
|
2006-09-30 13:38:06 +00:00
|
|
|
padded = xcalloc(1, size);
|
2001-03-20 02:06:40 +00:00
|
|
|
strlcpy(padded, password, size);
|
|
|
|
packet_put_string(padded, size);
|
2014-03-22 15:23:38 +00:00
|
|
|
explicit_bzero(padded, size);
|
2013-09-18 17:27:38 +00:00
|
|
|
free(padded);
|
2001-03-20 02:06:40 +00:00
|
|
|
}
|
2002-10-29 10:16:02 +00:00
|
|
|
|
|
|
|
/* print all known host keys for a given host, but skip keys of given type */
|
|
|
|
static int
|
2011-02-17 11:47:40 +00:00
|
|
|
show_other_keys(struct hostkeys *hostkeys, Key *key)
|
2002-10-29 10:16:02 +00:00
|
|
|
{
|
2014-01-30 10:56:49 +00:00
|
|
|
int type[] = {
|
|
|
|
KEY_RSA1,
|
|
|
|
KEY_RSA,
|
|
|
|
KEY_DSA,
|
|
|
|
KEY_ECDSA,
|
|
|
|
KEY_ED25519,
|
|
|
|
-1
|
|
|
|
};
|
2011-02-17 11:47:40 +00:00
|
|
|
int i, ret = 0;
|
|
|
|
char *fp, *ra;
|
|
|
|
const struct hostkey_entry *found;
|
2002-10-29 10:16:02 +00:00
|
|
|
|
|
|
|
for (i = 0; type[i] != -1; i++) {
|
|
|
|
if (type[i] == key->type)
|
|
|
|
continue;
|
2011-02-17 11:47:40 +00:00
|
|
|
if (!lookup_key_in_hostkeys_by_type(hostkeys, type[i], &found))
|
2002-10-29 10:16:02 +00:00
|
|
|
continue;
|
2011-02-17 11:47:40 +00:00
|
|
|
fp = key_fingerprint(found->key, SSH_FP_MD5, SSH_FP_HEX);
|
|
|
|
ra = key_fingerprint(found->key, SSH_FP_MD5, SSH_FP_RANDOMART);
|
|
|
|
logit("WARNING: %s key found for host %s\n"
|
|
|
|
"in %s:%lu\n"
|
|
|
|
"%s key fingerprint %s.",
|
|
|
|
key_type(found->key),
|
|
|
|
found->host, found->file, found->line,
|
|
|
|
key_type(found->key), fp);
|
|
|
|
if (options.visual_host_key)
|
|
|
|
logit("%s", ra);
|
2013-09-18 17:27:38 +00:00
|
|
|
free(ra);
|
|
|
|
free(fp);
|
2011-02-17 11:47:40 +00:00
|
|
|
ret = 1;
|
2002-10-29 10:16:02 +00:00
|
|
|
}
|
2011-02-17 11:47:40 +00:00
|
|
|
return ret;
|
2002-10-29 10:16:02 +00:00
|
|
|
}
|
2004-02-26 10:52:33 +00:00
|
|
|
|
|
|
|
static void
|
|
|
|
warn_changed_key(Key *host_key)
|
|
|
|
{
|
|
|
|
char *fp;
|
|
|
|
|
|
|
|
fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
|
|
|
|
|
|
|
|
error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
|
|
|
|
error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @");
|
|
|
|
error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
|
|
|
|
error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!");
|
|
|
|
error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!");
|
2011-02-17 11:47:40 +00:00
|
|
|
error("It is also possible that a host key has just been changed.");
|
2004-02-26 10:52:33 +00:00
|
|
|
error("The fingerprint for the %s key sent by the remote host is\n%s.",
|
2011-02-17 11:47:40 +00:00
|
|
|
key_type(host_key), fp);
|
2004-02-26 10:52:33 +00:00
|
|
|
error("Please contact your system administrator.");
|
|
|
|
|
2013-09-18 17:27:38 +00:00
|
|
|
free(fp);
|
2004-02-26 10:52:33 +00:00
|
|
|
}
|
2006-03-22 20:41:37 +00:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Execute a local command
|
|
|
|
*/
|
|
|
|
int
|
|
|
|
ssh_local_cmd(const char *args)
|
|
|
|
{
|
|
|
|
char *shell;
|
|
|
|
pid_t pid;
|
|
|
|
int status;
|
2011-02-17 11:47:40 +00:00
|
|
|
void (*osighand)(int);
|
2006-03-22 20:41:37 +00:00
|
|
|
|
|
|
|
if (!options.permit_local_command ||
|
|
|
|
args == NULL || !*args)
|
|
|
|
return (1);
|
|
|
|
|
2011-02-17 11:47:40 +00:00
|
|
|
if ((shell = getenv("SHELL")) == NULL || *shell == '\0')
|
2006-03-22 20:41:37 +00:00
|
|
|
shell = _PATH_BSHELL;
|
|
|
|
|
2011-02-17 11:47:40 +00:00
|
|
|
osighand = signal(SIGCHLD, SIG_DFL);
|
2006-03-22 20:41:37 +00:00
|
|
|
pid = fork();
|
|
|
|
if (pid == 0) {
|
2011-02-17 11:47:40 +00:00
|
|
|
signal(SIGPIPE, SIG_DFL);
|
2006-03-22 20:41:37 +00:00
|
|
|
debug3("Executing %s -c \"%s\"", shell, args);
|
|
|
|
execl(shell, shell, "-c", args, (char *)NULL);
|
|
|
|
error("Couldn't execute %s -c \"%s\": %s",
|
|
|
|
shell, args, strerror(errno));
|
|
|
|
_exit(1);
|
|
|
|
} else if (pid == -1)
|
|
|
|
fatal("fork failed: %.100s", strerror(errno));
|
|
|
|
while (waitpid(pid, &status, 0) == -1)
|
|
|
|
if (errno != EINTR)
|
|
|
|
fatal("Couldn't wait for child: %s", strerror(errno));
|
2011-02-17 11:47:40 +00:00
|
|
|
signal(SIGCHLD, osighand);
|
2006-03-22 20:41:37 +00:00
|
|
|
|
|
|
|
if (!WIFEXITED(status))
|
|
|
|
return (1);
|
|
|
|
|
|
|
|
return (WEXITSTATUS(status));
|
|
|
|
}
|