markus@openbsd.org | beb965b | 2017-05-30 14:13:40 +0000 | [diff] [blame] | 1 | /* $OpenBSD: sshconnect.c,v 1.280 2017/05/30 14:13:40 markus Exp $ */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 3 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
| 4 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 5 | * All rights reserved |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 6 | * Code to connect to a remote host, and to perform the client side of the |
| 7 | * login (authentication) dialog. |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 8 | * |
| 9 | * As far as I am concerned, the code I have written for this software |
| 10 | * can be used freely for any purpose. Any derived versions of this |
| 11 | * software must be clearly marked as such, and if the derived work is |
| 12 | * incompatible with the protocol description in the RFC file, it must be |
| 13 | * called by a name other than "ssh" or "Secure Shell". |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 14 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 15 | |
| 16 | #include "includes.h" |
Damien Miller | 9cf6d07 | 2006-03-15 11:29:24 +1100 | [diff] [blame] | 17 | |
| 18 | #include <sys/types.h> |
| 19 | #include <sys/wait.h> |
Damien Miller | f17883e | 2006-03-15 11:45:54 +1100 | [diff] [blame] | 20 | #include <sys/stat.h> |
Damien Miller | 8ec8c3e | 2006-07-10 20:35:38 +1000 | [diff] [blame] | 21 | #include <sys/socket.h> |
Damien Miller | 9aec919 | 2006-08-05 10:57:45 +1000 | [diff] [blame] | 22 | #ifdef HAVE_SYS_TIME_H |
| 23 | # include <sys/time.h> |
| 24 | #endif |
Damien Miller | 8ec8c3e | 2006-07-10 20:35:38 +1000 | [diff] [blame] | 25 | |
| 26 | #include <netinet/in.h> |
Darren Tucker | 46aa3e0 | 2006-09-02 15:32:40 +1000 | [diff] [blame] | 27 | #include <arpa/inet.h> |
Damien Miller | 03e2003 | 2006-03-15 11:16:59 +1100 | [diff] [blame] | 28 | |
Damien Miller | c7b0636 | 2006-03-15 11:53:45 +1100 | [diff] [blame] | 29 | #include <ctype.h> |
Darren Tucker | 3997249 | 2006-07-12 22:22:46 +1000 | [diff] [blame] | 30 | #include <errno.h> |
Darren Tucker | 6e7fe1c | 2010-01-08 17:07:22 +1100 | [diff] [blame] | 31 | #include <fcntl.h> |
Damien Miller | b8fe89c | 2006-07-24 14:51:00 +1000 | [diff] [blame] | 32 | #include <netdb.h> |
Damien Miller | 6645e7a | 2006-03-15 14:42:54 +1100 | [diff] [blame] | 33 | #ifdef HAVE_PATHS_H |
Damien Miller | 03e2003 | 2006-03-15 11:16:59 +1100 | [diff] [blame] | 34 | #include <paths.h> |
Damien Miller | 6645e7a | 2006-03-15 14:42:54 +1100 | [diff] [blame] | 35 | #endif |
Damien Miller | 9f2abc4 | 2006-07-10 20:53:08 +1000 | [diff] [blame] | 36 | #include <pwd.h> |
Damien Miller | 9c0c31d | 2010-10-12 13:30:44 +1100 | [diff] [blame] | 37 | #include <signal.h> |
Damien Miller | ded319c | 2006-09-01 15:38:36 +1000 | [diff] [blame] | 38 | #include <stdarg.h> |
Damien Miller | a7a73ee | 2006-08-05 11:37:59 +1000 | [diff] [blame] | 39 | #include <stdio.h> |
Damien Miller | e7a1e5c | 2006-08-05 11:34:19 +1000 | [diff] [blame] | 40 | #include <stdlib.h> |
Damien Miller | e3476ed | 2006-07-24 14:13:33 +1000 | [diff] [blame] | 41 | #include <string.h> |
Damien Miller | e6b3b61 | 2006-07-24 14:01:23 +1000 | [diff] [blame] | 42 | #include <unistd.h> |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 43 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 44 | #include "xmalloc.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 45 | #include "key.h" |
| 46 | #include "hostfile.h" |
| 47 | #include "ssh.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 48 | #include "rsa.h" |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 49 | #include "buffer.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 50 | #include "packet.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 51 | #include "uidswap.h" |
| 52 | #include "compat.h" |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 53 | #include "key.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 54 | #include "sshconnect.h" |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 55 | #include "hostfile.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 56 | #include "log.h" |
Damien Miller | 7acefbb | 2014-07-18 14:11:24 +1000 | [diff] [blame] | 57 | #include "misc.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 58 | #include "readconf.h" |
| 59 | #include "atomicio.h" |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 60 | #include "dns.h" |
Damien Miller | 1262b66 | 2013-08-21 02:44:24 +1000 | [diff] [blame] | 61 | #include "monitor_fdpass.h" |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 62 | #include "ssh2.h" |
Damien Miller | b757677 | 2006-07-10 20:23:39 +1000 | [diff] [blame] | 63 | #include "version.h" |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 64 | #include "authfile.h" |
| 65 | #include "ssherr.h" |
jcs@openbsd.org | f361df4 | 2015-11-15 22:26:49 +0000 | [diff] [blame] | 66 | #include "authfd.h" |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 67 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 68 | char *client_version_string = NULL; |
| 69 | char *server_version_string = NULL; |
markus@openbsd.org | 54d90ac | 2017-05-30 08:52:19 +0000 | [diff] [blame] | 70 | struct sshkey *previous_host_key = NULL; |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 71 | |
Damien Miller | c1af1d5 | 2005-11-05 15:08:57 +1100 | [diff] [blame] | 72 | static int matching_host_key_dns = 0; |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 73 | |
Damien Miller | a41ccca | 2010-10-07 22:07:32 +1100 | [diff] [blame] | 74 | static pid_t proxy_command_pid = 0; |
| 75 | |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 76 | /* import */ |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 77 | extern Options options; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 78 | extern char *__progname; |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 79 | extern uid_t original_real_uid; |
| 80 | extern uid_t original_effective_uid; |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 81 | |
markus@openbsd.org | 54d90ac | 2017-05-30 08:52:19 +0000 | [diff] [blame] | 82 | static int show_other_keys(struct hostkeys *, struct sshkey *); |
| 83 | static void warn_changed_key(struct sshkey *); |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 84 | |
Damien Miller | 1262b66 | 2013-08-21 02:44:24 +1000 | [diff] [blame] | 85 | /* Expand a proxy command */ |
| 86 | static char * |
| 87 | expand_proxy_command(const char *proxy_command, const char *user, |
| 88 | const char *host, int port) |
| 89 | { |
| 90 | char *tmp, *ret, strport[NI_MAXSERV]; |
| 91 | |
Damien Miller | 0faf747 | 2013-10-17 11:47:23 +1100 | [diff] [blame] | 92 | snprintf(strport, sizeof strport, "%d", port); |
Damien Miller | 1262b66 | 2013-08-21 02:44:24 +1000 | [diff] [blame] | 93 | xasprintf(&tmp, "exec %s", proxy_command); |
| 94 | ret = percent_expand(tmp, "h", host, "p", strport, |
| 95 | "r", options.user, (char *)NULL); |
| 96 | free(tmp); |
| 97 | return ret; |
| 98 | } |
| 99 | |
| 100 | /* |
| 101 | * Connect to the given ssh server using a proxy command that passes a |
| 102 | * a connected fd back to us. |
| 103 | */ |
| 104 | static int |
| 105 | ssh_proxy_fdpass_connect(const char *host, u_short port, |
| 106 | const char *proxy_command) |
| 107 | { |
| 108 | char *command_string; |
| 109 | int sp[2], sock; |
| 110 | pid_t pid; |
| 111 | char *shell; |
| 112 | |
| 113 | if ((shell = getenv("SHELL")) == NULL) |
| 114 | shell = _PATH_BSHELL; |
| 115 | |
| 116 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, sp) < 0) |
| 117 | fatal("Could not create socketpair to communicate with " |
| 118 | "proxy dialer: %.100s", strerror(errno)); |
| 119 | |
| 120 | command_string = expand_proxy_command(proxy_command, options.user, |
| 121 | host, port); |
| 122 | debug("Executing proxy dialer command: %.500s", command_string); |
| 123 | |
| 124 | /* Fork and execute the proxy command. */ |
| 125 | if ((pid = fork()) == 0) { |
| 126 | char *argv[10]; |
| 127 | |
| 128 | /* Child. Permanently give up superuser privileges. */ |
| 129 | permanently_drop_suid(original_real_uid); |
| 130 | |
| 131 | close(sp[1]); |
| 132 | /* Redirect stdin and stdout. */ |
| 133 | if (sp[0] != 0) { |
| 134 | if (dup2(sp[0], 0) < 0) |
| 135 | perror("dup2 stdin"); |
| 136 | } |
| 137 | if (sp[0] != 1) { |
| 138 | if (dup2(sp[0], 1) < 0) |
| 139 | perror("dup2 stdout"); |
| 140 | } |
| 141 | if (sp[0] >= 2) |
| 142 | close(sp[0]); |
| 143 | |
| 144 | /* |
| 145 | * Stderr is left as it is so that error messages get |
| 146 | * printed on the user's terminal. |
| 147 | */ |
| 148 | argv[0] = shell; |
| 149 | argv[1] = "-c"; |
| 150 | argv[2] = command_string; |
| 151 | argv[3] = NULL; |
| 152 | |
| 153 | /* |
| 154 | * Execute the proxy command. |
| 155 | * Note that we gave up any extra privileges above. |
| 156 | */ |
| 157 | execv(argv[0], argv); |
| 158 | perror(argv[0]); |
| 159 | exit(1); |
| 160 | } |
| 161 | /* Parent. */ |
| 162 | if (pid < 0) |
| 163 | fatal("fork failed: %.100s", strerror(errno)); |
| 164 | close(sp[0]); |
| 165 | free(command_string); |
| 166 | |
| 167 | if ((sock = mm_receive_fd(sp[1])) == -1) |
| 168 | fatal("proxy dialer did not pass back a connection"); |
markus@openbsd.org | fc77ccd | 2016-01-14 22:56:56 +0000 | [diff] [blame] | 169 | close(sp[1]); |
Damien Miller | 1262b66 | 2013-08-21 02:44:24 +1000 | [diff] [blame] | 170 | |
| 171 | while (waitpid(pid, NULL, 0) == -1) |
| 172 | if (errno != EINTR) |
| 173 | fatal("Couldn't wait for child: %s", strerror(errno)); |
| 174 | |
| 175 | /* Set the connection file descriptors. */ |
| 176 | packet_set_connection(sock, sock); |
Damien Miller | 1262b66 | 2013-08-21 02:44:24 +1000 | [diff] [blame] | 177 | |
| 178 | return 0; |
| 179 | } |
| 180 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 181 | /* |
| 182 | * Connect to the given ssh server using a proxy command. |
| 183 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 184 | static int |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 185 | ssh_proxy_connect(const char *host, u_short port, const char *proxy_command) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 186 | { |
Damien Miller | 1262b66 | 2013-08-21 02:44:24 +1000 | [diff] [blame] | 187 | char *command_string; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 188 | int pin[2], pout[2]; |
Damien Miller | 166fca8 | 2000-04-20 07:42:21 +1000 | [diff] [blame] | 189 | pid_t pid; |
Damien Miller | 1262b66 | 2013-08-21 02:44:24 +1000 | [diff] [blame] | 190 | char *shell; |
Damien Miller | 1d824ab | 2007-09-17 11:58:04 +1000 | [diff] [blame] | 191 | |
Damien Miller | 38d9a96 | 2010-10-07 22:07:11 +1100 | [diff] [blame] | 192 | if ((shell = getenv("SHELL")) == NULL || *shell == '\0') |
Damien Miller | 1d824ab | 2007-09-17 11:58:04 +1000 | [diff] [blame] | 193 | shell = _PATH_BSHELL; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 194 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 195 | /* Create pipes for communicating with the proxy. */ |
| 196 | if (pipe(pin) < 0 || pipe(pout) < 0) |
| 197 | fatal("Could not create pipes to communicate with the proxy: %.100s", |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 198 | strerror(errno)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 199 | |
Damien Miller | 1262b66 | 2013-08-21 02:44:24 +1000 | [diff] [blame] | 200 | command_string = expand_proxy_command(proxy_command, options.user, |
| 201 | host, port); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 202 | debug("Executing proxy command: %.500s", command_string); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 203 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 204 | /* Fork and execute the proxy command. */ |
| 205 | if ((pid = fork()) == 0) { |
| 206 | char *argv[10]; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 207 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 208 | /* Child. Permanently give up superuser privileges. */ |
Damien Miller | 2e5fe88 | 2006-06-13 13:10:00 +1000 | [diff] [blame] | 209 | permanently_drop_suid(original_real_uid); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 210 | |
| 211 | /* Redirect stdin and stdout. */ |
| 212 | close(pin[1]); |
| 213 | if (pin[0] != 0) { |
| 214 | if (dup2(pin[0], 0) < 0) |
| 215 | perror("dup2 stdin"); |
| 216 | close(pin[0]); |
| 217 | } |
| 218 | close(pout[0]); |
| 219 | if (dup2(pout[1], 1) < 0) |
| 220 | perror("dup2 stdout"); |
| 221 | /* Cannot be 1 because pin allocated two descriptors. */ |
| 222 | close(pout[1]); |
| 223 | |
| 224 | /* Stderr is left as it is so that error messages get |
| 225 | printed on the user's terminal. */ |
Damien Miller | 1d824ab | 2007-09-17 11:58:04 +1000 | [diff] [blame] | 226 | argv[0] = shell; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 227 | argv[1] = "-c"; |
| 228 | argv[2] = command_string; |
| 229 | argv[3] = NULL; |
| 230 | |
| 231 | /* Execute the proxy command. Note that we gave up any |
| 232 | extra privileges above. */ |
Damien Miller | 6fb6fd5 | 2011-01-16 23:17:45 +1100 | [diff] [blame] | 233 | signal(SIGPIPE, SIG_DFL); |
Kevin Steves | fcd5d60 | 2001-01-07 11:45:22 +0000 | [diff] [blame] | 234 | execv(argv[0], argv); |
| 235 | perror(argv[0]); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 236 | exit(1); |
| 237 | } |
| 238 | /* Parent. */ |
| 239 | if (pid < 0) |
| 240 | fatal("fork failed: %.100s", strerror(errno)); |
Damien Miller | 8c4e18a | 2002-09-19 12:05:02 +1000 | [diff] [blame] | 241 | else |
| 242 | proxy_command_pid = pid; /* save pid to clean up later */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 243 | |
| 244 | /* Close child side of the descriptors. */ |
| 245 | close(pin[0]); |
| 246 | close(pout[1]); |
| 247 | |
| 248 | /* Free the command name. */ |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 249 | free(command_string); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 250 | |
| 251 | /* Set the connection file descriptors. */ |
| 252 | packet_set_connection(pout[0], pin[1]); |
| 253 | |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 254 | /* Indicate OK return */ |
| 255 | return 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 256 | } |
| 257 | |
Damien Miller | a41ccca | 2010-10-07 22:07:32 +1100 | [diff] [blame] | 258 | void |
| 259 | ssh_kill_proxy_command(void) |
| 260 | { |
| 261 | /* |
| 262 | * Send SIGHUP to proxy command if used. We don't wait() in |
| 263 | * case it hangs and instead rely on init to reap the child |
| 264 | */ |
| 265 | if (proxy_command_pid > 1) |
Damien Miller | 45fcdaa | 2010-10-07 22:07:58 +1100 | [diff] [blame] | 266 | kill(proxy_command_pid, SIGHUP); |
Damien Miller | a41ccca | 2010-10-07 22:07:32 +1100 | [diff] [blame] | 267 | } |
| 268 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 269 | /* |
| 270 | * Creates a (possibly privileged) socket for use as the ssh connection. |
| 271 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 272 | static int |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 273 | ssh_create_socket(int privileged, struct addrinfo *ai) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 274 | { |
Darren Tucker | e6e52f8 | 2013-10-10 10:28:07 +1100 | [diff] [blame] | 275 | int sock, r, gaierr; |
Damien Miller | d1a7a9c | 2014-02-07 09:24:33 +1100 | [diff] [blame] | 276 | struct addrinfo hints, *res = NULL; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 277 | |
Darren Tucker | 7bd98e7 | 2010-01-10 10:31:12 +1100 | [diff] [blame] | 278 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
Darren Tucker | 6e7fe1c | 2010-01-08 17:07:22 +1100 | [diff] [blame] | 279 | if (sock < 0) { |
Darren Tucker | e6e52f8 | 2013-10-10 10:28:07 +1100 | [diff] [blame] | 280 | error("socket: %s", strerror(errno)); |
Darren Tucker | 6e7fe1c | 2010-01-08 17:07:22 +1100 | [diff] [blame] | 281 | return -1; |
| 282 | } |
| 283 | fcntl(sock, F_SETFD, FD_CLOEXEC); |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 284 | |
| 285 | /* Bind the socket to an alternative local IP address */ |
Darren Tucker | e6e52f8 | 2013-10-10 10:28:07 +1100 | [diff] [blame] | 286 | if (options.bind_address == NULL && !privileged) |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 287 | return sock; |
| 288 | |
Damien Miller | d1a7a9c | 2014-02-07 09:24:33 +1100 | [diff] [blame] | 289 | if (options.bind_address) { |
| 290 | memset(&hints, 0, sizeof(hints)); |
| 291 | hints.ai_family = ai->ai_family; |
| 292 | hints.ai_socktype = ai->ai_socktype; |
| 293 | hints.ai_protocol = ai->ai_protocol; |
| 294 | hints.ai_flags = AI_PASSIVE; |
| 295 | gaierr = getaddrinfo(options.bind_address, NULL, &hints, &res); |
| 296 | if (gaierr) { |
| 297 | error("getaddrinfo: %s: %s", options.bind_address, |
| 298 | ssh_gai_strerror(gaierr)); |
| 299 | close(sock); |
| 300 | return -1; |
| 301 | } |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 302 | } |
Darren Tucker | e6e52f8 | 2013-10-10 10:28:07 +1100 | [diff] [blame] | 303 | /* |
| 304 | * If we are running as root and want to connect to a privileged |
| 305 | * port, bind our own socket to a privileged port. |
| 306 | */ |
| 307 | if (privileged) { |
| 308 | PRIV_START; |
Damien Miller | d1a7a9c | 2014-02-07 09:24:33 +1100 | [diff] [blame] | 309 | r = bindresvport_sa(sock, res ? res->ai_addr : NULL); |
Darren Tucker | e6e52f8 | 2013-10-10 10:28:07 +1100 | [diff] [blame] | 310 | PRIV_END; |
| 311 | if (r < 0) { |
| 312 | error("bindresvport_sa: af=%d %s", ai->ai_family, |
| 313 | strerror(errno)); |
| 314 | goto fail; |
| 315 | } |
| 316 | } else { |
| 317 | if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) { |
| 318 | error("bind: %s: %s", options.bind_address, |
| 319 | strerror(errno)); |
| 320 | fail: |
| 321 | close(sock); |
| 322 | freeaddrinfo(res); |
| 323 | return -1; |
| 324 | } |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 325 | } |
Damien Miller | d1a7a9c | 2014-02-07 09:24:33 +1100 | [diff] [blame] | 326 | if (res != NULL) |
| 327 | freeaddrinfo(res); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 328 | return sock; |
| 329 | } |
| 330 | |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 331 | static int |
| 332 | timeout_connect(int sockfd, const struct sockaddr *serv_addr, |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 333 | socklen_t addrlen, int *timeoutp) |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 334 | { |
| 335 | fd_set *fdset; |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 336 | struct timeval tv, t_start; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 337 | socklen_t optlen; |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 338 | int optval, rc, result = -1; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 339 | |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 340 | gettimeofday(&t_start, NULL); |
| 341 | |
| 342 | if (*timeoutp <= 0) { |
| 343 | result = connect(sockfd, serv_addr, addrlen); |
| 344 | goto done; |
| 345 | } |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 346 | |
Damien Miller | f6723f0 | 2004-01-27 21:21:27 +1100 | [diff] [blame] | 347 | set_nonblock(sockfd); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 348 | rc = connect(sockfd, serv_addr, addrlen); |
Damien Miller | f6723f0 | 2004-01-27 21:21:27 +1100 | [diff] [blame] | 349 | if (rc == 0) { |
| 350 | unset_nonblock(sockfd); |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 351 | result = 0; |
| 352 | goto done; |
Damien Miller | f6723f0 | 2004-01-27 21:21:27 +1100 | [diff] [blame] | 353 | } |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 354 | if (errno != EINPROGRESS) { |
| 355 | result = -1; |
| 356 | goto done; |
| 357 | } |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 358 | |
deraadt@openbsd.org | ce445b0 | 2015-08-20 22:32:42 +0000 | [diff] [blame] | 359 | fdset = xcalloc(howmany(sockfd + 1, NFDBITS), |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 360 | sizeof(fd_mask)); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 361 | FD_SET(sockfd, fdset); |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 362 | ms_to_timeval(&tv, *timeoutp); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 363 | |
Darren Tucker | 47eede7 | 2005-03-14 23:08:12 +1100 | [diff] [blame] | 364 | for (;;) { |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 365 | rc = select(sockfd + 1, NULL, fdset, NULL, &tv); |
| 366 | if (rc != -1 || errno != EINTR) |
| 367 | break; |
| 368 | } |
| 369 | |
Darren Tucker | 47eede7 | 2005-03-14 23:08:12 +1100 | [diff] [blame] | 370 | switch (rc) { |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 371 | case 0: |
| 372 | /* Timed out */ |
| 373 | errno = ETIMEDOUT; |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 374 | break; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 375 | case -1: |
| 376 | /* Select error */ |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 377 | debug("select: %s", strerror(errno)); |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 378 | break; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 379 | case 1: |
| 380 | /* Completed or failed */ |
| 381 | optval = 0; |
| 382 | optlen = sizeof(optval); |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 383 | if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, |
Darren Tucker | bd5361b | 2003-09-22 20:59:16 +1000 | [diff] [blame] | 384 | &optlen) == -1) { |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 385 | debug("getsockopt: %s", strerror(errno)); |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 386 | break; |
Darren Tucker | bd5361b | 2003-09-22 20:59:16 +1000 | [diff] [blame] | 387 | } |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 388 | if (optval != 0) { |
| 389 | errno = optval; |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 390 | break; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 391 | } |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 392 | result = 0; |
Damien Miller | f6723f0 | 2004-01-27 21:21:27 +1100 | [diff] [blame] | 393 | unset_nonblock(sockfd); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 394 | break; |
| 395 | default: |
| 396 | /* Should not occur */ |
| 397 | fatal("Bogus return (%d) from select()", rc); |
| 398 | } |
| 399 | |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 400 | free(fdset); |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 401 | |
| 402 | done: |
| 403 | if (result == 0 && *timeoutp > 0) { |
| 404 | ms_subtract_diff(&t_start, timeoutp); |
| 405 | if (*timeoutp <= 0) { |
| 406 | errno = ETIMEDOUT; |
| 407 | result = -1; |
| 408 | } |
| 409 | } |
| 410 | |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 411 | return (result); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 412 | } |
| 413 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 414 | /* |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 415 | * Opens a TCP/IP connection to the remote server on the given host. |
| 416 | * The address of the remote host will be returned in hostaddr. |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 417 | * If port is 0, the default port will be used. If needpriv is true, |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 418 | * a privileged port will be allocated to make the connection. |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 419 | * This requires super-user privileges if needpriv is true. |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 420 | * Connection_attempts specifies the maximum number of tries (one per |
| 421 | * second). If proxy_command is non-NULL, it specifies the command (with %h |
| 422 | * and %p substituted for host and port, respectively) to use to contact |
| 423 | * the daemon. |
| 424 | */ |
Damien Miller | 0faf747 | 2013-10-17 11:47:23 +1100 | [diff] [blame] | 425 | static int |
| 426 | ssh_connect_direct(const char *host, struct addrinfo *aitop, |
| 427 | struct sockaddr_storage *hostaddr, u_short port, int family, |
| 428 | int connection_attempts, int *timeout_ms, int want_keepalive, int needpriv) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 429 | { |
Ben Lindstrom | bf555ba | 2001-01-18 02:04:35 +0000 | [diff] [blame] | 430 | int on = 1; |
| 431 | int sock = -1, attempt; |
| 432 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
Damien Miller | 0faf747 | 2013-10-17 11:47:23 +1100 | [diff] [blame] | 433 | struct addrinfo *ai; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 434 | |
djm@openbsd.org | 46152af | 2015-09-04 04:55:24 +0000 | [diff] [blame] | 435 | debug2("%s: needpriv %d", __func__, needpriv); |
djm@openbsd.org | 88b6fcd | 2015-11-19 08:23:27 +0000 | [diff] [blame] | 436 | memset(ntop, 0, sizeof(ntop)); |
| 437 | memset(strport, 0, sizeof(strport)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 438 | |
Damien Miller | 56e5e6a | 2006-04-23 12:08:59 +1000 | [diff] [blame] | 439 | for (attempt = 0; attempt < connection_attempts; attempt++) { |
Damien Miller | f4bcd10 | 2006-10-24 03:02:23 +1000 | [diff] [blame] | 440 | if (attempt > 0) { |
| 441 | /* Sleep a moment before retrying. */ |
| 442 | sleep(1); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 443 | debug("Trying again..."); |
Damien Miller | f4bcd10 | 2006-10-24 03:02:23 +1000 | [diff] [blame] | 444 | } |
Damien Miller | 56e5e6a | 2006-04-23 12:08:59 +1000 | [diff] [blame] | 445 | /* |
| 446 | * Loop through addresses for this host, and try each one in |
| 447 | * sequence until the connection succeeds. |
| 448 | */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 449 | for (ai = aitop; ai; ai = ai->ai_next) { |
Damien Miller | 0faf747 | 2013-10-17 11:47:23 +1100 | [diff] [blame] | 450 | if (ai->ai_family != AF_INET && |
| 451 | ai->ai_family != AF_INET6) |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 452 | continue; |
| 453 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, |
| 454 | ntop, sizeof(ntop), strport, sizeof(strport), |
| 455 | NI_NUMERICHOST|NI_NUMERICSERV) != 0) { |
djm@openbsd.org | 46152af | 2015-09-04 04:55:24 +0000 | [diff] [blame] | 456 | error("%s: getnameinfo failed", __func__); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 457 | continue; |
| 458 | } |
| 459 | debug("Connecting to %.200s [%.100s] port %s.", |
| 460 | host, ntop, strport); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 461 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 462 | /* Create a socket for connecting. */ |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 463 | sock = ssh_create_socket(needpriv, ai); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 464 | if (sock < 0) |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 465 | /* Any error is already output */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 466 | continue; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 467 | |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 468 | if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen, |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 469 | timeout_ms) >= 0) { |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 470 | /* Successful connection. */ |
Ben Lindstrom | a370005 | 2001-04-05 23:26:32 +0000 | [diff] [blame] | 471 | memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 472 | break; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 473 | } else { |
Ben Lindstrom | 728aa7e | 2002-07-15 17:48:11 +0000 | [diff] [blame] | 474 | debug("connect to address %s port %s: %s", |
| 475 | ntop, strport, strerror(errno)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 476 | close(sock); |
Damien Miller | 56e5e6a | 2006-04-23 12:08:59 +1000 | [diff] [blame] | 477 | sock = -1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 478 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 479 | } |
Damien Miller | 56e5e6a | 2006-04-23 12:08:59 +1000 | [diff] [blame] | 480 | if (sock != -1) |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 481 | break; /* Successful connection. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 482 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 483 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 484 | /* Return failure if we didn't get a successful connection. */ |
Damien Miller | 56e5e6a | 2006-04-23 12:08:59 +1000 | [diff] [blame] | 485 | if (sock == -1) { |
Darren Tucker | b2161e3 | 2005-01-20 11:00:46 +1100 | [diff] [blame] | 486 | error("ssh: connect to host %s port %s: %s", |
Ben Lindstrom | a6cd75c | 2002-07-11 04:00:19 +0000 | [diff] [blame] | 487 | host, strport, strerror(errno)); |
Darren Tucker | b2161e3 | 2005-01-20 11:00:46 +1100 | [diff] [blame] | 488 | return (-1); |
Ben Lindstrom | a6cd75c | 2002-07-11 04:00:19 +0000 | [diff] [blame] | 489 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 490 | |
| 491 | debug("Connection established."); |
| 492 | |
Damien Miller | 12c150e | 2003-12-17 16:31:10 +1100 | [diff] [blame] | 493 | /* Set SO_KEEPALIVE if requested. */ |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 494 | if (want_keepalive && |
Ben Lindstrom | bf555ba | 2001-01-18 02:04:35 +0000 | [diff] [blame] | 495 | setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, |
| 496 | sizeof(on)) < 0) |
| 497 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 498 | |
| 499 | /* Set the connection. */ |
| 500 | packet_set_connection(sock, sock); |
| 501 | |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 502 | return 0; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 503 | } |
| 504 | |
Damien Miller | 0faf747 | 2013-10-17 11:47:23 +1100 | [diff] [blame] | 505 | int |
| 506 | ssh_connect(const char *host, struct addrinfo *addrs, |
| 507 | struct sockaddr_storage *hostaddr, u_short port, int family, |
| 508 | int connection_attempts, int *timeout_ms, int want_keepalive, int needpriv) |
| 509 | { |
| 510 | if (options.proxy_command == NULL) { |
| 511 | return ssh_connect_direct(host, addrs, hostaddr, port, family, |
| 512 | connection_attempts, timeout_ms, want_keepalive, needpriv); |
| 513 | } else if (strcmp(options.proxy_command, "-") == 0) { |
| 514 | packet_set_connection(STDIN_FILENO, STDOUT_FILENO); |
| 515 | return 0; /* Always succeeds */ |
| 516 | } else if (options.proxy_use_fdpass) { |
| 517 | return ssh_proxy_fdpass_connect(host, port, |
| 518 | options.proxy_command); |
| 519 | } |
| 520 | return ssh_proxy_connect(host, port, options.proxy_command); |
| 521 | } |
| 522 | |
Darren Tucker | 00c1518 | 2012-09-06 21:21:56 +1000 | [diff] [blame] | 523 | static void |
| 524 | send_client_banner(int connection_out, int minor1) |
| 525 | { |
Darren Tucker | 00c1518 | 2012-09-06 21:21:56 +1000 | [diff] [blame] | 526 | /* Send our own protocol version identification. */ |
djm@openbsd.org | 97f4d30 | 2017-04-30 23:13:25 +0000 | [diff] [blame] | 527 | xasprintf(&client_version_string, "SSH-%d.%d-%.100s\r\n", |
| 528 | PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2, SSH_VERSION); |
markus@openbsd.org | a306863 | 2016-01-14 16:17:39 +0000 | [diff] [blame] | 529 | if (atomicio(vwrite, connection_out, client_version_string, |
Darren Tucker | 00c1518 | 2012-09-06 21:21:56 +1000 | [diff] [blame] | 530 | strlen(client_version_string)) != strlen(client_version_string)) |
| 531 | fatal("write: %.100s", strerror(errno)); |
| 532 | chop(client_version_string); |
| 533 | debug("Local version string %.100s", client_version_string); |
| 534 | } |
| 535 | |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 536 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 537 | * Waits for the server identification string, and sends our own |
| 538 | * identification string. |
| 539 | */ |
Darren Tucker | 1cc55d7 | 2009-06-21 18:17:19 +1000 | [diff] [blame] | 540 | void |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 541 | ssh_exchange_identification(int timeout_ms) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 542 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 543 | char buf[256], remote_version[256]; /* must be same size! */ |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 544 | int remote_major, remote_minor, mismatch; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 545 | int connection_in = packet_get_connection_in(); |
| 546 | int connection_out = packet_get_connection_out(); |
Damien Miller | 1e88ea6 | 2006-07-10 20:15:56 +1000 | [diff] [blame] | 547 | u_int i, n; |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 548 | size_t len; |
| 549 | int fdsetsz, remaining, rc; |
| 550 | struct timeval t_start, t_remaining; |
| 551 | fd_set *fdset; |
| 552 | |
| 553 | fdsetsz = howmany(connection_in + 1, NFDBITS) * sizeof(fd_mask); |
| 554 | fdset = xcalloc(1, fdsetsz); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 555 | |
djm@openbsd.org | 99f95ba | 2017-04-30 23:11:45 +0000 | [diff] [blame] | 556 | send_client_banner(connection_out, 0); |
Darren Tucker | 00c1518 | 2012-09-06 21:21:56 +1000 | [diff] [blame] | 557 | |
Damien Miller | b253cc4 | 2005-05-26 12:23:44 +1000 | [diff] [blame] | 558 | /* Read other side's version identification. */ |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 559 | remaining = timeout_ms; |
Damien Miller | 1e88ea6 | 2006-07-10 20:15:56 +1000 | [diff] [blame] | 560 | for (n = 0;;) { |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 561 | for (i = 0; i < sizeof(buf) - 1; i++) { |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 562 | if (timeout_ms > 0) { |
| 563 | gettimeofday(&t_start, NULL); |
| 564 | ms_to_timeval(&t_remaining, remaining); |
| 565 | FD_SET(connection_in, fdset); |
| 566 | rc = select(connection_in + 1, fdset, NULL, |
| 567 | fdset, &t_remaining); |
| 568 | ms_subtract_diff(&t_start, &remaining); |
| 569 | if (rc == 0 || remaining <= 0) |
| 570 | fatal("Connection timed out during " |
| 571 | "banner exchange"); |
| 572 | if (rc == -1) { |
| 573 | if (errno == EINTR) |
| 574 | continue; |
| 575 | fatal("ssh_exchange_identification: " |
| 576 | "select: %s", strerror(errno)); |
| 577 | } |
| 578 | } |
| 579 | |
markus@openbsd.org | a306863 | 2016-01-14 16:17:39 +0000 | [diff] [blame] | 580 | len = atomicio(read, connection_in, &buf[i], 1); |
Damien Miller | b253cc4 | 2005-05-26 12:23:44 +1000 | [diff] [blame] | 581 | |
Damien Miller | 46d38de | 2005-07-17 17:02:09 +1000 | [diff] [blame] | 582 | if (len != 1 && errno == EPIPE) |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 583 | fatal("ssh_exchange_identification: " |
| 584 | "Connection closed by remote host"); |
Damien Miller | b253cc4 | 2005-05-26 12:23:44 +1000 | [diff] [blame] | 585 | else if (len != 1) |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 586 | fatal("ssh_exchange_identification: " |
| 587 | "read: %.100s", strerror(errno)); |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 588 | if (buf[i] == '\r') { |
| 589 | buf[i] = '\n'; |
| 590 | buf[i + 1] = 0; |
| 591 | continue; /**XXX wait for \n */ |
| 592 | } |
| 593 | if (buf[i] == '\n') { |
| 594 | buf[i + 1] = 0; |
| 595 | break; |
| 596 | } |
Damien Miller | 1e88ea6 | 2006-07-10 20:15:56 +1000 | [diff] [blame] | 597 | if (++n > 65536) |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 598 | fatal("ssh_exchange_identification: " |
| 599 | "No banner received"); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 600 | } |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 601 | buf[sizeof(buf) - 1] = 0; |
| 602 | if (strncmp(buf, "SSH-", 4) == 0) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 603 | break; |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 604 | debug("ssh_exchange_identification: %s", buf); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 605 | } |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 606 | server_version_string = xstrdup(buf); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 607 | free(fdset); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 608 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 609 | /* |
| 610 | * Check that the versions match. In future this might accept |
| 611 | * several versions and set appropriate flags to handle them. |
| 612 | */ |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 613 | if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n", |
| 614 | &remote_major, &remote_minor, remote_version) != 3) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 615 | fatal("Bad remote protocol version identification: '%.100s'", buf); |
| 616 | debug("Remote protocol version %d.%d, remote software version %.100s", |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 617 | remote_major, remote_minor, remote_version); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 618 | |
markus@openbsd.org | 48b3b2b | 2015-01-19 20:20:20 +0000 | [diff] [blame] | 619 | active_state->compat = compat_datafellows(remote_version); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 620 | mismatch = 0; |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 621 | |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 622 | switch (remote_major) { |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 623 | case 2: |
djm@openbsd.org | 97f4d30 | 2017-04-30 23:13:25 +0000 | [diff] [blame] | 624 | break; |
| 625 | case 1: |
| 626 | if (remote_minor != 99) |
| 627 | mismatch = 1; |
djm@openbsd.org | 99f95ba | 2017-04-30 23:11:45 +0000 | [diff] [blame] | 628 | break; |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 629 | default: |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 630 | mismatch = 1; |
| 631 | break; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 632 | } |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 633 | if (mismatch) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 634 | fatal("Protocol major versions differ: %d vs. %d", |
djm@openbsd.org | 99f95ba | 2017-04-30 23:11:45 +0000 | [diff] [blame] | 635 | PROTOCOL_MAJOR_2, remote_major); |
Damien Miller | 58cd63b | 2014-01-10 10:59:24 +1100 | [diff] [blame] | 636 | if ((datafellows & SSH_BUG_DERIVEKEY) != 0) |
| 637 | fatal("Server version \"%.100s\" uses unsafe key agreement; " |
| 638 | "refusing connection", remote_version); |
Damien Miller | 324541e | 2013-12-31 12:25:40 +1100 | [diff] [blame] | 639 | if ((datafellows & SSH_BUG_RSASIGMD5) != 0) |
| 640 | logit("Server version \"%.100s\" uses unsafe RSA signature " |
| 641 | "scheme; disabling use of RSA keys", remote_version); |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 642 | chop(server_version_string); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 643 | } |
| 644 | |
Ben Lindstrom | b6c06d9 | 2001-02-10 23:21:09 +0000 | [diff] [blame] | 645 | /* defaults to 'no' */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 646 | static int |
Damien Miller | e398004 | 2001-10-10 15:02:03 +1000 | [diff] [blame] | 647 | confirm(const char *prompt) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 648 | { |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 649 | const char *msg, *again = "Please type 'yes' or 'no': "; |
| 650 | char *p; |
| 651 | int ret = -1; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 652 | |
Ben Lindstrom | b6c06d9 | 2001-02-10 23:21:09 +0000 | [diff] [blame] | 653 | if (options.batch_mode) |
| 654 | return 0; |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 655 | for (msg = prompt;;msg = again) { |
| 656 | p = read_passphrase(msg, RP_ECHO); |
| 657 | if (p == NULL || |
| 658 | (p[0] == '\0') || (p[0] == '\n') || |
| 659 | strncasecmp(p, "no", 2) == 0) |
| 660 | ret = 0; |
Ben Lindstrom | 04f9af7 | 2002-07-04 00:03:56 +0000 | [diff] [blame] | 661 | if (p && strncasecmp(p, "yes", 3) == 0) |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 662 | ret = 1; |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 663 | free(p); |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 664 | if (ret != -1) |
| 665 | return ret; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 666 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 667 | } |
| 668 | |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 669 | static int |
markus@openbsd.org | 54d90ac | 2017-05-30 08:52:19 +0000 | [diff] [blame] | 670 | check_host_cert(const char *host, const struct sshkey *host_key) |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 671 | { |
| 672 | const char *reason; |
| 673 | |
| 674 | if (key_cert_check_authority(host_key, 1, 0, host, &reason) != 0) { |
| 675 | error("%s", reason); |
| 676 | return 0; |
| 677 | } |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 678 | if (buffer_len(host_key->cert->critical) != 0) { |
Damien Miller | 4e270b0 | 2010-04-16 15:56:21 +1000 | [diff] [blame] | 679 | error("Certificate for %s contains unsupported " |
| 680 | "critical options(s)", host); |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 681 | return 0; |
| 682 | } |
| 683 | return 1; |
| 684 | } |
| 685 | |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 686 | static int |
| 687 | sockaddr_is_local(struct sockaddr *hostaddr) |
| 688 | { |
| 689 | switch (hostaddr->sa_family) { |
| 690 | case AF_INET: |
| 691 | return (ntohl(((struct sockaddr_in *)hostaddr)-> |
| 692 | sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; |
| 693 | case AF_INET6: |
| 694 | return IN6_IS_ADDR_LOOPBACK( |
| 695 | &(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); |
| 696 | default: |
| 697 | return 0; |
| 698 | } |
| 699 | } |
| 700 | |
| 701 | /* |
| 702 | * Prepare the hostname and ip address strings that are used to lookup |
| 703 | * host keys in known_hosts files. These may have a port number appended. |
| 704 | */ |
| 705 | void |
| 706 | get_hostfile_hostname_ipaddr(char *hostname, struct sockaddr *hostaddr, |
| 707 | u_short port, char **hostfile_hostname, char **hostfile_ipaddr) |
| 708 | { |
| 709 | char ntop[NI_MAXHOST]; |
| 710 | socklen_t addrlen; |
| 711 | |
| 712 | switch (hostaddr == NULL ? -1 : hostaddr->sa_family) { |
| 713 | case -1: |
| 714 | addrlen = 0; |
| 715 | break; |
| 716 | case AF_INET: |
| 717 | addrlen = sizeof(struct sockaddr_in); |
| 718 | break; |
| 719 | case AF_INET6: |
| 720 | addrlen = sizeof(struct sockaddr_in6); |
| 721 | break; |
| 722 | default: |
| 723 | addrlen = sizeof(struct sockaddr); |
| 724 | break; |
| 725 | } |
| 726 | |
| 727 | /* |
| 728 | * We don't have the remote ip-address for connections |
| 729 | * using a proxy command |
| 730 | */ |
| 731 | if (hostfile_ipaddr != NULL) { |
| 732 | if (options.proxy_command == NULL) { |
| 733 | if (getnameinfo(hostaddr, addrlen, |
| 734 | ntop, sizeof(ntop), NULL, 0, NI_NUMERICHOST) != 0) |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 735 | fatal("%s: getnameinfo failed", __func__); |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 736 | *hostfile_ipaddr = put_host_port(ntop, port); |
| 737 | } else { |
| 738 | *hostfile_ipaddr = xstrdup("<no hostip for proxy " |
| 739 | "command>"); |
| 740 | } |
| 741 | } |
| 742 | |
| 743 | /* |
| 744 | * Allow the user to record the key under a different name or |
| 745 | * differentiate a non-standard port. This is useful for ssh |
| 746 | * tunneling over forwarded connections or if you run multiple |
| 747 | * sshd's on different ports on the same machine. |
| 748 | */ |
| 749 | if (hostfile_hostname != NULL) { |
| 750 | if (options.host_key_alias != NULL) { |
| 751 | *hostfile_hostname = xstrdup(options.host_key_alias); |
| 752 | debug("using hostkeyalias: %s", *hostfile_hostname); |
| 753 | } else { |
| 754 | *hostfile_hostname = put_host_port(hostname, port); |
| 755 | } |
| 756 | } |
| 757 | } |
| 758 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 759 | /* |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 760 | * check whether the supplied host key is valid, return -1 if the key |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 761 | * is not valid. user_hostfile[0] will not be updated if 'readonly' is true. |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 762 | */ |
Damien Miller | da82839 | 2006-08-05 11:35:45 +1000 | [diff] [blame] | 763 | #define RDRW 0 |
| 764 | #define RDONLY 1 |
| 765 | #define ROQUIET 2 |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 766 | static int |
Damien Miller | da82839 | 2006-08-05 11:35:45 +1000 | [diff] [blame] | 767 | check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, |
markus@openbsd.org | 54d90ac | 2017-05-30 08:52:19 +0000 | [diff] [blame] | 768 | struct sshkey *host_key, int readonly, |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 769 | char **user_hostfiles, u_int num_user_hostfiles, |
| 770 | char **system_hostfiles, u_int num_system_hostfiles) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 771 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 772 | HostStatus host_status; |
| 773 | HostStatus ip_status; |
markus@openbsd.org | 54d90ac | 2017-05-30 08:52:19 +0000 | [diff] [blame] | 774 | struct sshkey *raw_key = NULL; |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 775 | char *ip = NULL, *host = NULL; |
| 776 | char hostline[1000], *hostp, *fp, *ra; |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 777 | char msg[1024]; |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 778 | const char *type; |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 779 | const struct hostkey_entry *host_found, *ip_found; |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 780 | int len, cancelled_forwarding = 0; |
| 781 | int local = sockaddr_is_local(hostaddr); |
markus@openbsd.org | beb965b | 2017-05-30 14:13:40 +0000 | [diff] [blame] | 782 | int r, want_cert = sshkey_is_cert(host_key), host_ip_differ = 0; |
djm@openbsd.org | 8d4f872 | 2015-01-26 03:04:45 +0000 | [diff] [blame] | 783 | int hostkey_trusted = 0; /* Known or explicitly accepted by user */ |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 784 | struct hostkeys *host_hostkeys, *ip_hostkeys; |
| 785 | u_int i; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 786 | |
| 787 | /* |
| 788 | * Force accepting of the host key for loopback/localhost. The |
| 789 | * problem is that if the home directory is NFS-mounted to multiple |
| 790 | * machines, localhost will refer to a different machine in each of |
| 791 | * them, and the user will get bogus HOST_CHANGED warnings. This |
| 792 | * essentially disables host authentication for localhost; however, |
| 793 | * this is probably not a real problem. |
| 794 | */ |
Ben Lindstrom | 3cecc9a | 2001-10-03 17:39:38 +0000 | [diff] [blame] | 795 | if (options.no_host_authentication_for_localhost == 1 && local && |
| 796 | options.host_key_alias == NULL) { |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 797 | debug("Forcing accepting of host key for " |
| 798 | "loopback/localhost."); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 799 | return 0; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 800 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 801 | |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 802 | /* |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 803 | * Prepare the hostname and address strings used for hostkey lookup. |
| 804 | * In some cases, these will have a port number appended. |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 805 | */ |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 806 | get_hostfile_hostname_ipaddr(hostname, hostaddr, port, &host, &ip); |
Darren Tucker | 78913e0 | 2008-06-13 04:47:34 +1000 | [diff] [blame] | 807 | |
| 808 | /* |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 809 | * Turn off check_host_ip if the connection is to localhost, via proxy |
| 810 | * command or if we don't have a hostname to compare with |
| 811 | */ |
Darren Tucker | da34553 | 2006-07-10 23:04:19 +1000 | [diff] [blame] | 812 | if (options.check_host_ip && (local || |
| 813 | strcmp(hostname, ip) == 0 || options.proxy_command != NULL)) |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 814 | options.check_host_ip = 0; |
| 815 | |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 816 | host_hostkeys = init_hostkeys(); |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 817 | for (i = 0; i < num_user_hostfiles; i++) |
| 818 | load_hostkeys(host_hostkeys, host, user_hostfiles[i]); |
| 819 | for (i = 0; i < num_system_hostfiles; i++) |
| 820 | load_hostkeys(host_hostkeys, host, system_hostfiles[i]); |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 821 | |
| 822 | ip_hostkeys = NULL; |
| 823 | if (!want_cert && options.check_host_ip) { |
| 824 | ip_hostkeys = init_hostkeys(); |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 825 | for (i = 0; i < num_user_hostfiles; i++) |
| 826 | load_hostkeys(ip_hostkeys, ip, user_hostfiles[i]); |
| 827 | for (i = 0; i < num_system_hostfiles; i++) |
| 828 | load_hostkeys(ip_hostkeys, ip, system_hostfiles[i]); |
Ben Lindstrom | 4dccfa5 | 2000-12-28 16:40:05 +0000 | [diff] [blame] | 829 | } |
| 830 | |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 831 | retry: |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 832 | /* Reload these as they may have changed on cert->key downgrade */ |
markus@openbsd.org | beb965b | 2017-05-30 14:13:40 +0000 | [diff] [blame] | 833 | want_cert = sshkey_is_cert(host_key); |
| 834 | type = sshkey_type(host_key); |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 835 | |
Ben Lindstrom | 4dccfa5 | 2000-12-28 16:40:05 +0000 | [diff] [blame] | 836 | /* |
Damien Miller | 788f212 | 2005-11-05 15:14:59 +1100 | [diff] [blame] | 837 | * Check if the host key is present in the user's list of known |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 838 | * hosts or in the systemwide list. |
| 839 | */ |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 840 | host_status = check_key_in_hostkeys(host_hostkeys, host_key, |
| 841 | &host_found); |
| 842 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 843 | /* |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 844 | * Also perform check for the ip address, skip the check if we are |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 845 | * localhost, looking for a certificate, or the hostname was an ip |
| 846 | * address to begin with. |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 847 | */ |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 848 | if (!want_cert && ip_hostkeys != NULL) { |
| 849 | ip_status = check_key_in_hostkeys(ip_hostkeys, host_key, |
| 850 | &ip_found); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 851 | if (host_status == HOST_CHANGED && |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 852 | (ip_status != HOST_CHANGED || |
| 853 | (ip_found != NULL && |
markus@openbsd.org | beb965b | 2017-05-30 14:13:40 +0000 | [diff] [blame] | 854 | !sshkey_equal(ip_found->key, host_found->key)))) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 855 | host_ip_differ = 1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 856 | } else |
| 857 | ip_status = host_status; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 858 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 859 | switch (host_status) { |
| 860 | case HOST_OK: |
| 861 | /* The host is known and the key matches. */ |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 862 | debug("Host '%.200s' is known and matches the %s host %s.", |
| 863 | host, type, want_cert ? "certificate" : "key"); |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 864 | debug("Found %s in %s:%lu", want_cert ? "CA key" : "key", |
| 865 | host_found->file, host_found->line); |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 866 | if (want_cert && !check_host_cert(hostname, host_key)) |
| 867 | goto fail; |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 868 | if (options.check_host_ip && ip_status == HOST_NEW) { |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 869 | if (readonly || want_cert) |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 870 | logit("%s host key for IP address " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 871 | "'%.128s' not in list of known hosts.", |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 872 | type, ip); |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 873 | else if (!add_host_to_hostfile(user_hostfiles[0], ip, |
Damien Miller | e177615 | 2005-03-01 21:47:37 +1100 | [diff] [blame] | 874 | host_key, options.hash_known_hosts)) |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 875 | logit("Failed to add the %s host key for IP " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 876 | "address '%.128s' to the list of known " |
dtucker@openbsd.org | 496aeb2 | 2015-05-28 05:41:29 +0000 | [diff] [blame] | 877 | "hosts (%.500s).", type, ip, |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 878 | user_hostfiles[0]); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 879 | else |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 880 | logit("Warning: Permanently added the %s host " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 881 | "key for IP address '%.128s' to the list " |
| 882 | "of known hosts.", type, ip); |
Damien Miller | 1028824 | 2008-06-30 00:04:03 +1000 | [diff] [blame] | 883 | } else if (options.visual_host_key) { |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 884 | fp = sshkey_fingerprint(host_key, |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 885 | options.fingerprint_hash, SSH_FP_DEFAULT); |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 886 | ra = sshkey_fingerprint(host_key, |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 887 | options.fingerprint_hash, SSH_FP_RANDOMART); |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 888 | if (fp == NULL || ra == NULL) |
| 889 | fatal("%s: sshkey_fingerprint fail", __func__); |
djm@openbsd.org | ac3451d | 2015-09-04 03:57:38 +0000 | [diff] [blame] | 890 | logit("Host key fingerprint is %s\n%s", fp, ra); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 891 | free(ra); |
| 892 | free(fp); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 893 | } |
djm@openbsd.org | 8d4f872 | 2015-01-26 03:04:45 +0000 | [diff] [blame] | 894 | hostkey_trusted = 1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 895 | break; |
| 896 | case HOST_NEW: |
Damien Miller | da82839 | 2006-08-05 11:35:45 +1000 | [diff] [blame] | 897 | if (options.host_key_alias == NULL && port != 0 && |
| 898 | port != SSH_DEFAULT_PORT) { |
| 899 | debug("checking without port identifier"); |
Damien Miller | ece92c8 | 2008-11-03 19:25:03 +1100 | [diff] [blame] | 900 | if (check_host_key(hostname, hostaddr, 0, host_key, |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 901 | ROQUIET, user_hostfiles, num_user_hostfiles, |
| 902 | system_hostfiles, num_system_hostfiles) == 0) { |
Damien Miller | da82839 | 2006-08-05 11:35:45 +1000 | [diff] [blame] | 903 | debug("found matching key w/out port"); |
| 904 | break; |
| 905 | } |
| 906 | } |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 907 | if (readonly || want_cert) |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 908 | goto fail; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 909 | /* The host is new. */ |
| 910 | if (options.strict_host_key_checking == 1) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 911 | /* |
| 912 | * User has requested strict host key checking. We |
| 913 | * will not add the host key automatically. The only |
| 914 | * alternative left is to abort. |
| 915 | */ |
| 916 | error("No %s host key is known for %.200s and you " |
| 917 | "have requested strict checking.", type, host); |
| 918 | goto fail; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 919 | } else if (options.strict_host_key_checking == 2) { |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 920 | char msg1[1024], msg2[1024]; |
| 921 | |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 922 | if (show_other_keys(host_hostkeys, host_key)) |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 923 | snprintf(msg1, sizeof(msg1), |
Damien Miller | 0dc1bef | 2005-07-17 17:22:45 +1000 | [diff] [blame] | 924 | "\nbut keys of different type are already" |
| 925 | " known for this host."); |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 926 | else |
| 927 | snprintf(msg1, sizeof(msg1), "."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 928 | /* The default */ |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 929 | fp = sshkey_fingerprint(host_key, |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 930 | options.fingerprint_hash, SSH_FP_DEFAULT); |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 931 | ra = sshkey_fingerprint(host_key, |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 932 | options.fingerprint_hash, SSH_FP_RANDOMART); |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 933 | if (fp == NULL || ra == NULL) |
| 934 | fatal("%s: sshkey_fingerprint fail", __func__); |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 935 | msg2[0] = '\0'; |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 936 | if (options.verify_host_key_dns) { |
Damien Miller | 150b557 | 2003-11-17 21:19:29 +1100 | [diff] [blame] | 937 | if (matching_host_key_dns) |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 938 | snprintf(msg2, sizeof(msg2), |
| 939 | "Matching host key fingerprint" |
| 940 | " found in DNS.\n"); |
| 941 | else |
| 942 | snprintf(msg2, sizeof(msg2), |
| 943 | "No matching host key fingerprint" |
| 944 | " found in DNS.\n"); |
| 945 | } |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 946 | snprintf(msg, sizeof(msg), |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 947 | "The authenticity of host '%.200s (%s)' can't be " |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 948 | "established%s\n" |
Damien Miller | 1028824 | 2008-06-30 00:04:03 +1000 | [diff] [blame] | 949 | "%s key fingerprint is %s.%s%s\n%s" |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 950 | "Are you sure you want to continue connecting " |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 951 | "(yes/no)? ", |
Damien Miller | 1028824 | 2008-06-30 00:04:03 +1000 | [diff] [blame] | 952 | host, ip, msg1, type, fp, |
| 953 | options.visual_host_key ? "\n" : "", |
| 954 | options.visual_host_key ? ra : "", |
| 955 | msg2); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 956 | free(ra); |
| 957 | free(fp); |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 958 | if (!confirm(msg)) |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 959 | goto fail; |
djm@openbsd.org | 8d4f872 | 2015-01-26 03:04:45 +0000 | [diff] [blame] | 960 | hostkey_trusted = 1; /* user explicitly confirmed */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 961 | } |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 962 | /* |
| 963 | * If not in strict mode, add the key automatically to the |
| 964 | * local known_hosts file. |
| 965 | */ |
Damien Miller | 1227d4c | 2005-03-02 12:06:51 +1100 | [diff] [blame] | 966 | if (options.check_host_ip && ip_status == HOST_NEW) { |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 967 | snprintf(hostline, sizeof(hostline), "%s,%s", host, ip); |
Damien Miller | 1227d4c | 2005-03-02 12:06:51 +1100 | [diff] [blame] | 968 | hostp = hostline; |
| 969 | if (options.hash_known_hosts) { |
| 970 | /* Add hash of host and IP separately */ |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 971 | r = add_host_to_hostfile(user_hostfiles[0], |
| 972 | host, host_key, options.hash_known_hosts) && |
| 973 | add_host_to_hostfile(user_hostfiles[0], ip, |
Damien Miller | 1227d4c | 2005-03-02 12:06:51 +1100 | [diff] [blame] | 974 | host_key, options.hash_known_hosts); |
| 975 | } else { |
| 976 | /* Add unhashed "host,ip" */ |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 977 | r = add_host_to_hostfile(user_hostfiles[0], |
Damien Miller | 1227d4c | 2005-03-02 12:06:51 +1100 | [diff] [blame] | 978 | hostline, host_key, |
| 979 | options.hash_known_hosts); |
| 980 | } |
| 981 | } else { |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 982 | r = add_host_to_hostfile(user_hostfiles[0], host, |
| 983 | host_key, options.hash_known_hosts); |
Damien Miller | 1227d4c | 2005-03-02 12:06:51 +1100 | [diff] [blame] | 984 | hostp = host; |
| 985 | } |
| 986 | |
| 987 | if (!r) |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 988 | logit("Failed to add the host to the list of known " |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 989 | "hosts (%.500s).", user_hostfiles[0]); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 990 | else |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 991 | logit("Warning: Permanently added '%.200s' (%s) to the " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 992 | "list of known hosts.", hostp, type); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 993 | break; |
Damien Miller | 1aed65e | 2010-03-04 21:53:35 +1100 | [diff] [blame] | 994 | case HOST_REVOKED: |
| 995 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 996 | error("@ WARNING: REVOKED HOST KEY DETECTED! @"); |
| 997 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 998 | error("The %s host key for %s is marked as revoked.", type, host); |
| 999 | error("This could mean that a stolen key is being used to"); |
| 1000 | error("impersonate this host."); |
| 1001 | |
| 1002 | /* |
| 1003 | * If strict host key checking is in use, the user will have |
| 1004 | * to edit the key manually and we can only abort. |
| 1005 | */ |
| 1006 | if (options.strict_host_key_checking) { |
| 1007 | error("%s host key for %.200s was revoked and you have " |
| 1008 | "requested strict checking.", type, host); |
| 1009 | goto fail; |
| 1010 | } |
| 1011 | goto continue_unsafe; |
| 1012 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1013 | case HOST_CHANGED: |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 1014 | if (want_cert) { |
| 1015 | /* |
| 1016 | * This is only a debug() since it is valid to have |
| 1017 | * CAs with wildcard DNS matches that don't match |
| 1018 | * all hosts that one might visit. |
| 1019 | */ |
| 1020 | debug("Host certificate authority does not " |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1021 | "match %s in %s:%lu", CA_MARKER, |
| 1022 | host_found->file, host_found->line); |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 1023 | goto fail; |
| 1024 | } |
Damien Miller | da82839 | 2006-08-05 11:35:45 +1000 | [diff] [blame] | 1025 | if (readonly == ROQUIET) |
| 1026 | goto fail; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1027 | if (options.check_host_ip && host_ip_differ) { |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 1028 | char *key_msg; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1029 | if (ip_status == HOST_NEW) |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 1030 | key_msg = "is unknown"; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1031 | else if (ip_status == HOST_OK) |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 1032 | key_msg = "is unchanged"; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1033 | else |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 1034 | key_msg = "has a different value"; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1035 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 1036 | error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @"); |
| 1037 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 1038 | error("The %s host key for %s has changed,", type, host); |
Darren Tucker | ff4454d | 2008-06-13 10:21:51 +1000 | [diff] [blame] | 1039 | error("and the key for the corresponding IP address %s", ip); |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 1040 | error("%s. This could either mean that", key_msg); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1041 | error("DNS SPOOFING is happening or the IP address for the host"); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1042 | error("and its host key have changed at the same time."); |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 1043 | if (ip_status != HOST_NEW) |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1044 | error("Offending key for IP in %s:%lu", |
| 1045 | ip_found->file, ip_found->line); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1046 | } |
| 1047 | /* The host key has changed. */ |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1048 | warn_changed_key(host_key); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1049 | error("Add correct host key in %.100s to get rid of this message.", |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 1050 | user_hostfiles[0]); |
markus@openbsd.org | beb965b | 2017-05-30 14:13:40 +0000 | [diff] [blame] | 1051 | error("Offending %s key in %s:%lu", |
| 1052 | sshkey_type(host_found->key), |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1053 | host_found->file, host_found->line); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1054 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1055 | /* |
| 1056 | * If strict host key checking is in use, the user will have |
| 1057 | * to edit the key manually and we can only abort. |
| 1058 | */ |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1059 | if (options.strict_host_key_checking) { |
| 1060 | error("%s host key for %.200s has changed and you have " |
| 1061 | "requested strict checking.", type, host); |
| 1062 | goto fail; |
| 1063 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1064 | |
Damien Miller | 1aed65e | 2010-03-04 21:53:35 +1100 | [diff] [blame] | 1065 | continue_unsafe: |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1066 | /* |
| 1067 | * If strict host key checking has not been requested, allow |
Damien Miller | 941ac45 | 2003-06-04 20:31:53 +1000 | [diff] [blame] | 1068 | * the connection but without MITM-able authentication or |
Damien Miller | 437edb9 | 2006-08-05 09:11:13 +1000 | [diff] [blame] | 1069 | * forwarding. |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1070 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1071 | if (options.password_authentication) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1072 | error("Password authentication is disabled to avoid " |
| 1073 | "man-in-the-middle attacks."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1074 | options.password_authentication = 0; |
Darren Tucker | 068e01f | 2008-07-02 22:33:55 +1000 | [diff] [blame] | 1075 | cancelled_forwarding = 1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1076 | } |
Damien Miller | 941ac45 | 2003-06-04 20:31:53 +1000 | [diff] [blame] | 1077 | if (options.kbd_interactive_authentication) { |
| 1078 | error("Keyboard-interactive authentication is disabled" |
| 1079 | " to avoid man-in-the-middle attacks."); |
| 1080 | options.kbd_interactive_authentication = 0; |
| 1081 | options.challenge_response_authentication = 0; |
Darren Tucker | 068e01f | 2008-07-02 22:33:55 +1000 | [diff] [blame] | 1082 | cancelled_forwarding = 1; |
Damien Miller | 941ac45 | 2003-06-04 20:31:53 +1000 | [diff] [blame] | 1083 | } |
| 1084 | if (options.challenge_response_authentication) { |
| 1085 | error("Challenge/response authentication is disabled" |
| 1086 | " to avoid man-in-the-middle attacks."); |
| 1087 | options.challenge_response_authentication = 0; |
Darren Tucker | 068e01f | 2008-07-02 22:33:55 +1000 | [diff] [blame] | 1088 | cancelled_forwarding = 1; |
Damien Miller | 941ac45 | 2003-06-04 20:31:53 +1000 | [diff] [blame] | 1089 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1090 | if (options.forward_agent) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1091 | error("Agent forwarding is disabled to avoid " |
| 1092 | "man-in-the-middle attacks."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1093 | options.forward_agent = 0; |
Darren Tucker | 068e01f | 2008-07-02 22:33:55 +1000 | [diff] [blame] | 1094 | cancelled_forwarding = 1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1095 | } |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 1096 | if (options.forward_x11) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1097 | error("X11 forwarding is disabled to avoid " |
| 1098 | "man-in-the-middle attacks."); |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 1099 | options.forward_x11 = 0; |
Darren Tucker | 068e01f | 2008-07-02 22:33:55 +1000 | [diff] [blame] | 1100 | cancelled_forwarding = 1; |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 1101 | } |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1102 | if (options.num_local_forwards > 0 || |
| 1103 | options.num_remote_forwards > 0) { |
| 1104 | error("Port forwarding is disabled to avoid " |
| 1105 | "man-in-the-middle attacks."); |
| 1106 | options.num_local_forwards = |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 1107 | options.num_remote_forwards = 0; |
Darren Tucker | 068e01f | 2008-07-02 22:33:55 +1000 | [diff] [blame] | 1108 | cancelled_forwarding = 1; |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 1109 | } |
Damien Miller | 437edb9 | 2006-08-05 09:11:13 +1000 | [diff] [blame] | 1110 | if (options.tun_open != SSH_TUNMODE_NO) { |
| 1111 | error("Tunnel forwarding is disabled to avoid " |
| 1112 | "man-in-the-middle attacks."); |
| 1113 | options.tun_open = SSH_TUNMODE_NO; |
Darren Tucker | 068e01f | 2008-07-02 22:33:55 +1000 | [diff] [blame] | 1114 | cancelled_forwarding = 1; |
Damien Miller | 437edb9 | 2006-08-05 09:11:13 +1000 | [diff] [blame] | 1115 | } |
Darren Tucker | 068e01f | 2008-07-02 22:33:55 +1000 | [diff] [blame] | 1116 | if (options.exit_on_forward_failure && cancelled_forwarding) |
| 1117 | fatal("Error: forwarding disabled due to host key " |
| 1118 | "check failure"); |
| 1119 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1120 | /* |
| 1121 | * XXX Should permit the user to change to use the new id. |
| 1122 | * This could be done by converting the host key to an |
| 1123 | * identifying sentence, tell that the host identifies itself |
Darren Tucker | e2b3674 | 2010-01-13 22:42:34 +1100 | [diff] [blame] | 1124 | * by that sentence, and ask the user if he/she wishes to |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1125 | * accept the authentication. |
| 1126 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1127 | break; |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 1128 | case HOST_FOUND: |
| 1129 | fatal("internal error"); |
| 1130 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1131 | } |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 1132 | |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 1133 | if (options.check_host_ip && host_status != HOST_CHANGED && |
| 1134 | ip_status == HOST_CHANGED) { |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 1135 | snprintf(msg, sizeof(msg), |
| 1136 | "Warning: the %s host key for '%.200s' " |
| 1137 | "differs from the key for the IP address '%.128s'" |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1138 | "\nOffending key for IP in %s:%lu", |
| 1139 | type, host, ip, ip_found->file, ip_found->line); |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 1140 | if (host_status == HOST_OK) { |
| 1141 | len = strlen(msg); |
| 1142 | snprintf(msg + len, sizeof(msg) - len, |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1143 | "\nMatching host key in %s:%lu", |
| 1144 | host_found->file, host_found->line); |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 1145 | } |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 1146 | if (options.strict_host_key_checking == 1) { |
Damien Miller | ab2db41 | 2003-06-02 19:09:13 +1000 | [diff] [blame] | 1147 | logit("%s", msg); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1148 | error("Exiting, you have requested strict checking."); |
| 1149 | goto fail; |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 1150 | } else if (options.strict_host_key_checking == 2) { |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 1151 | strlcat(msg, "\nAre you sure you want " |
| 1152 | "to continue connecting (yes/no)? ", sizeof(msg)); |
| 1153 | if (!confirm(msg)) |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1154 | goto fail; |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 1155 | } else { |
Damien Miller | ab2db41 | 2003-06-02 19:09:13 +1000 | [diff] [blame] | 1156 | logit("%s", msg); |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 1157 | } |
| 1158 | } |
| 1159 | |
djm@openbsd.org | 8d4f872 | 2015-01-26 03:04:45 +0000 | [diff] [blame] | 1160 | if (!hostkey_trusted && options.update_hostkeys) { |
| 1161 | debug("%s: hostkey not known or explicitly trusted: " |
| 1162 | "disabling UpdateHostkeys", __func__); |
| 1163 | options.update_hostkeys = 0; |
| 1164 | } |
| 1165 | |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 1166 | free(ip); |
| 1167 | free(host); |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1168 | if (host_hostkeys != NULL) |
| 1169 | free_hostkeys(host_hostkeys); |
| 1170 | if (ip_hostkeys != NULL) |
| 1171 | free_hostkeys(ip_hostkeys); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1172 | return 0; |
| 1173 | |
| 1174 | fail: |
Damien Miller | 1aed65e | 2010-03-04 21:53:35 +1100 | [diff] [blame] | 1175 | if (want_cert && host_status != HOST_REVOKED) { |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 1176 | /* |
| 1177 | * No matching certificate. Downgrade cert to raw key and |
| 1178 | * search normally. |
| 1179 | */ |
| 1180 | debug("No matching CA found. Retry with plain key"); |
markus@openbsd.org | beb965b | 2017-05-30 14:13:40 +0000 | [diff] [blame] | 1181 | if ((r = sshkey_from_private(host_key, &raw_key)) != 0) |
| 1182 | fatal("%s: sshkey_from_private: %s", |
| 1183 | __func__, ssh_err(r)); |
| 1184 | if ((r = sshkey_drop_cert(raw_key)) != 0) |
| 1185 | fatal("Couldn't drop certificate: %s", ssh_err(r)); |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 1186 | host_key = raw_key; |
| 1187 | goto retry; |
| 1188 | } |
| 1189 | if (raw_key != NULL) |
markus@openbsd.org | beb965b | 2017-05-30 14:13:40 +0000 | [diff] [blame] | 1190 | sshkey_free(raw_key); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 1191 | free(ip); |
| 1192 | free(host); |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1193 | if (host_hostkeys != NULL) |
| 1194 | free_hostkeys(host_hostkeys); |
| 1195 | if (ip_hostkeys != NULL) |
| 1196 | free_hostkeys(ip_hostkeys); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1197 | return -1; |
| 1198 | } |
| 1199 | |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 1200 | /* returns 0 if key verifies or -1 if key does NOT verify */ |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1201 | int |
markus@openbsd.org | 54d90ac | 2017-05-30 08:52:19 +0000 | [diff] [blame] | 1202 | verify_host_key(char *host, struct sockaddr *hostaddr, struct sshkey *host_key) |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1203 | { |
djm@openbsd.org | f96516d | 2015-11-19 01:09:38 +0000 | [diff] [blame] | 1204 | u_int i; |
Damien Miller | 6b37fbb | 2014-07-04 08:59:24 +1000 | [diff] [blame] | 1205 | int r = -1, flags = 0; |
djm@openbsd.org | f96516d | 2015-11-19 01:09:38 +0000 | [diff] [blame] | 1206 | char valid[64], *fp = NULL, *cafp = NULL; |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 1207 | struct sshkey *plain = NULL; |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1208 | |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 1209 | if ((fp = sshkey_fingerprint(host_key, |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 1210 | options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) { |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 1211 | error("%s: fingerprint host key: %s", __func__, ssh_err(r)); |
| 1212 | r = -1; |
| 1213 | goto out; |
| 1214 | } |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1215 | |
djm@openbsd.org | f96516d | 2015-11-19 01:09:38 +0000 | [diff] [blame] | 1216 | if (sshkey_is_cert(host_key)) { |
| 1217 | if ((cafp = sshkey_fingerprint(host_key->cert->signature_key, |
| 1218 | options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) { |
| 1219 | error("%s: fingerprint CA key: %s", |
| 1220 | __func__, ssh_err(r)); |
| 1221 | r = -1; |
| 1222 | goto out; |
| 1223 | } |
| 1224 | sshkey_format_cert_validity(host_key->cert, |
| 1225 | valid, sizeof(valid)); |
| 1226 | debug("Server host certificate: %s %s, serial %llu " |
| 1227 | "ID \"%s\" CA %s %s valid %s", |
| 1228 | sshkey_ssh_name(host_key), fp, |
djm@openbsd.org | 8ca915f | 2015-11-20 01:45:29 +0000 | [diff] [blame] | 1229 | (unsigned long long)host_key->cert->serial, |
| 1230 | host_key->cert->key_id, |
djm@openbsd.org | f96516d | 2015-11-19 01:09:38 +0000 | [diff] [blame] | 1231 | sshkey_ssh_name(host_key->cert->signature_key), cafp, |
| 1232 | valid); |
| 1233 | for (i = 0; i < host_key->cert->nprincipals; i++) { |
| 1234 | debug2("Server host certificate hostname: %s", |
| 1235 | host_key->cert->principals[i]); |
| 1236 | } |
| 1237 | } else { |
djm@openbsd.org | 97f4d30 | 2017-04-30 23:13:25 +0000 | [diff] [blame] | 1238 | debug("Server host key: %s %s", sshkey_ssh_name(host_key), fp); |
djm@openbsd.org | f96516d | 2015-11-19 01:09:38 +0000 | [diff] [blame] | 1239 | } |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 1240 | |
| 1241 | if (sshkey_equal(previous_host_key, host_key)) { |
| 1242 | debug2("%s: server host key %s %s matches cached key", |
| 1243 | __func__, sshkey_type(host_key), fp); |
| 1244 | r = 0; |
| 1245 | goto out; |
| 1246 | } |
| 1247 | |
| 1248 | /* Check in RevokedHostKeys file if specified */ |
| 1249 | if (options.revoked_host_keys != NULL) { |
| 1250 | r = sshkey_check_revoked(host_key, options.revoked_host_keys); |
| 1251 | switch (r) { |
| 1252 | case 0: |
| 1253 | break; /* not revoked */ |
| 1254 | case SSH_ERR_KEY_REVOKED: |
| 1255 | error("Host key %s %s revoked by file %s", |
| 1256 | sshkey_type(host_key), fp, |
| 1257 | options.revoked_host_keys); |
| 1258 | r = -1; |
| 1259 | goto out; |
| 1260 | default: |
| 1261 | error("Error checking host key %s %s in " |
| 1262 | "revoked keys file %s: %s", sshkey_type(host_key), |
| 1263 | fp, options.revoked_host_keys, ssh_err(r)); |
| 1264 | r = -1; |
| 1265 | goto out; |
| 1266 | } |
Damien Miller | 6b37fbb | 2014-07-04 08:59:24 +1000 | [diff] [blame] | 1267 | } |
| 1268 | |
Damien Miller | 7d6a9fb | 2014-04-20 13:23:43 +1000 | [diff] [blame] | 1269 | if (options.verify_host_key_dns) { |
| 1270 | /* |
| 1271 | * XXX certs are not yet supported for DNS, so downgrade |
| 1272 | * them and try the plain key. |
| 1273 | */ |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 1274 | if ((r = sshkey_from_private(host_key, &plain)) != 0) |
| 1275 | goto out; |
| 1276 | if (sshkey_is_cert(plain)) |
| 1277 | sshkey_drop_cert(plain); |
Damien Miller | 7d6a9fb | 2014-04-20 13:23:43 +1000 | [diff] [blame] | 1278 | if (verify_host_key_dns(host, hostaddr, plain, &flags) == 0) { |
| 1279 | if (flags & DNS_VERIFY_FOUND) { |
| 1280 | if (options.verify_host_key_dns == 1 && |
| 1281 | flags & DNS_VERIFY_MATCH && |
| 1282 | flags & DNS_VERIFY_SECURE) { |
Damien Miller | 6b37fbb | 2014-07-04 08:59:24 +1000 | [diff] [blame] | 1283 | r = 0; |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 1284 | goto out; |
Damien Miller | 7d6a9fb | 2014-04-20 13:23:43 +1000 | [diff] [blame] | 1285 | } |
| 1286 | if (flags & DNS_VERIFY_MATCH) { |
| 1287 | matching_host_key_dns = 1; |
| 1288 | } else { |
| 1289 | warn_changed_key(plain); |
| 1290 | error("Update the SSHFP RR in DNS " |
| 1291 | "with the new host key to get rid " |
| 1292 | "of this message."); |
| 1293 | } |
Damien Miller | 150b557 | 2003-11-17 21:19:29 +1100 | [diff] [blame] | 1294 | } |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 1295 | } |
| 1296 | } |
Damien Miller | 6b37fbb | 2014-07-04 08:59:24 +1000 | [diff] [blame] | 1297 | r = check_host_key(host, hostaddr, options.port, host_key, RDRW, |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 1298 | options.user_hostfiles, options.num_user_hostfiles, |
| 1299 | options.system_hostfiles, options.num_system_hostfiles); |
Damien Miller | 6b37fbb | 2014-07-04 08:59:24 +1000 | [diff] [blame] | 1300 | |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 1301 | out: |
| 1302 | sshkey_free(plain); |
| 1303 | free(fp); |
djm@openbsd.org | f96516d | 2015-11-19 01:09:38 +0000 | [diff] [blame] | 1304 | free(cafp); |
Damien Miller | 6b37fbb | 2014-07-04 08:59:24 +1000 | [diff] [blame] | 1305 | if (r == 0 && host_key != NULL) { |
markus@openbsd.org | beb965b | 2017-05-30 14:13:40 +0000 | [diff] [blame] | 1306 | sshkey_free(previous_host_key); |
| 1307 | r = sshkey_from_private(host_key, &previous_host_key); |
Damien Miller | 6b37fbb | 2014-07-04 08:59:24 +1000 | [diff] [blame] | 1308 | } |
| 1309 | |
| 1310 | return r; |
Damien Miller | a34a28b | 1999-12-14 10:47:15 +1100 | [diff] [blame] | 1311 | } |
Damien Miller | 037a0dc | 1999-12-07 15:38:31 +1100 | [diff] [blame] | 1312 | |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1313 | /* |
| 1314 | * Starts a dialog with the server, and authenticates the current user on the |
| 1315 | * server. This does not need any extra privileges. The basic connection |
| 1316 | * to the server must already have been established before this is called. |
| 1317 | * If login fails, this function prints an error and never returns. |
| 1318 | * This function does not require super-user privileges. |
| 1319 | */ |
| 1320 | void |
Ben Lindstrom | 1bad256 | 2002-06-06 19:57:33 +0000 | [diff] [blame] | 1321 | ssh_login(Sensitive *sensitive, const char *orighost, |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1322 | struct sockaddr *hostaddr, u_short port, struct passwd *pw, int timeout_ms) |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1323 | { |
Damien Miller | 0faf747 | 2013-10-17 11:47:23 +1100 | [diff] [blame] | 1324 | char *host; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1325 | char *server_user, *local_user; |
| 1326 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1327 | local_user = xstrdup(pw->pw_name); |
| 1328 | server_user = options.user ? options.user : local_user; |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1329 | |
| 1330 | /* Convert the user-supplied hostname into all lowercase. */ |
| 1331 | host = xstrdup(orighost); |
Damien Miller | 0faf747 | 2013-10-17 11:47:23 +1100 | [diff] [blame] | 1332 | lowercase(host); |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1333 | |
| 1334 | /* Exchange protocol version identification strings with the server. */ |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 1335 | ssh_exchange_identification(timeout_ms); |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1336 | |
| 1337 | /* Put the connection into non-blocking mode. */ |
| 1338 | packet_set_nonblocking(); |
| 1339 | |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1340 | /* key exchange */ |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1341 | /* authenticate user */ |
dtucker@openbsd.org | bb2289e | 2015-04-14 04:17:03 +0000 | [diff] [blame] | 1342 | debug("Authenticating to %s:%d as '%s'", host, port, server_user); |
djm@openbsd.org | 97f4d30 | 2017-04-30 23:13:25 +0000 | [diff] [blame] | 1343 | ssh_kex2(host, hostaddr, port); |
| 1344 | ssh_userauth2(local_user, server_user, host, sensitive); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 1345 | free(local_user); |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1346 | } |
Damien Miller | 79438cc | 2001-02-16 12:34:57 +1100 | [diff] [blame] | 1347 | |
| 1348 | void |
| 1349 | ssh_put_password(char *password) |
| 1350 | { |
| 1351 | int size; |
| 1352 | char *padded; |
| 1353 | |
Ben Lindstrom | d20d0f3 | 2001-03-10 17:22:20 +0000 | [diff] [blame] | 1354 | if (datafellows & SSH_BUG_PASSWORDPAD) { |
Ben Lindstrom | 664408d | 2001-06-09 01:42:01 +0000 | [diff] [blame] | 1355 | packet_put_cstring(password); |
Ben Lindstrom | d20d0f3 | 2001-03-10 17:22:20 +0000 | [diff] [blame] | 1356 | return; |
| 1357 | } |
deraadt@openbsd.org | 9136ec1 | 2016-09-12 01:22:38 +0000 | [diff] [blame] | 1358 | size = ROUNDUP(strlen(password) + 1, 32); |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 1359 | padded = xcalloc(1, size); |
Damien Miller | 79438cc | 2001-02-16 12:34:57 +1100 | [diff] [blame] | 1360 | strlcpy(padded, password, size); |
| 1361 | packet_put_string(padded, size); |
Damien Miller | a5103f4 | 2014-02-04 11:20:14 +1100 | [diff] [blame] | 1362 | explicit_bzero(padded, size); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 1363 | free(padded); |
Damien Miller | 79438cc | 2001-02-16 12:34:57 +1100 | [diff] [blame] | 1364 | } |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 1365 | |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 1366 | /* print all known host keys for a given host, but skip keys of given type */ |
| 1367 | static int |
markus@openbsd.org | 54d90ac | 2017-05-30 08:52:19 +0000 | [diff] [blame] | 1368 | show_other_keys(struct hostkeys *hostkeys, struct sshkey *key) |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 1369 | { |
Damien Miller | 106bf1c | 2013-12-29 17:54:03 +1100 | [diff] [blame] | 1370 | int type[] = { |
Damien Miller | 106bf1c | 2013-12-29 17:54:03 +1100 | [diff] [blame] | 1371 | KEY_RSA, |
| 1372 | KEY_DSA, |
| 1373 | KEY_ECDSA, |
| 1374 | KEY_ED25519, |
| 1375 | -1 |
| 1376 | }; |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1377 | int i, ret = 0; |
| 1378 | char *fp, *ra; |
| 1379 | const struct hostkey_entry *found; |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 1380 | |
| 1381 | for (i = 0; type[i] != -1; i++) { |
| 1382 | if (type[i] == key->type) |
| 1383 | continue; |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1384 | if (!lookup_key_in_hostkeys_by_type(hostkeys, type[i], &found)) |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 1385 | continue; |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 1386 | fp = sshkey_fingerprint(found->key, |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 1387 | options.fingerprint_hash, SSH_FP_DEFAULT); |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 1388 | ra = sshkey_fingerprint(found->key, |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 1389 | options.fingerprint_hash, SSH_FP_RANDOMART); |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 1390 | if (fp == NULL || ra == NULL) |
| 1391 | fatal("%s: sshkey_fingerprint fail", __func__); |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1392 | logit("WARNING: %s key found for host %s\n" |
| 1393 | "in %s:%lu\n" |
| 1394 | "%s key fingerprint %s.", |
| 1395 | key_type(found->key), |
| 1396 | found->host, found->file, found->line, |
| 1397 | key_type(found->key), fp); |
| 1398 | if (options.visual_host_key) |
| 1399 | logit("%s", ra); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 1400 | free(ra); |
| 1401 | free(fp); |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1402 | ret = 1; |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 1403 | } |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1404 | return ret; |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 1405 | } |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1406 | |
| 1407 | static void |
markus@openbsd.org | 54d90ac | 2017-05-30 08:52:19 +0000 | [diff] [blame] | 1408 | warn_changed_key(struct sshkey *host_key) |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1409 | { |
| 1410 | char *fp; |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1411 | |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 1412 | fp = sshkey_fingerprint(host_key, options.fingerprint_hash, |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 1413 | SSH_FP_DEFAULT); |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 1414 | if (fp == NULL) |
| 1415 | fatal("%s: sshkey_fingerprint fail", __func__); |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1416 | |
| 1417 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 1418 | error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @"); |
| 1419 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 1420 | error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!"); |
| 1421 | error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!"); |
Damien Miller | 05c8997 | 2011-01-06 22:42:04 +1100 | [diff] [blame] | 1422 | error("It is also possible that a host key has just been changed."); |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1423 | error("The fingerprint for the %s key sent by the remote host is\n%s.", |
Damien Miller | 05c8997 | 2011-01-06 22:42:04 +1100 | [diff] [blame] | 1424 | key_type(host_key), fp); |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1425 | error("Please contact your system administrator."); |
| 1426 | |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 1427 | free(fp); |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1428 | } |
Damien Miller | d27b947 | 2005-12-13 19:29:02 +1100 | [diff] [blame] | 1429 | |
| 1430 | /* |
| 1431 | * Execute a local command |
| 1432 | */ |
| 1433 | int |
| 1434 | ssh_local_cmd(const char *args) |
| 1435 | { |
| 1436 | char *shell; |
| 1437 | pid_t pid; |
| 1438 | int status; |
Damien Miller | ed3a8eb | 2011-01-07 10:02:52 +1100 | [diff] [blame] | 1439 | void (*osighand)(int); |
Damien Miller | d27b947 | 2005-12-13 19:29:02 +1100 | [diff] [blame] | 1440 | |
| 1441 | if (!options.permit_local_command || |
| 1442 | args == NULL || !*args) |
| 1443 | return (1); |
| 1444 | |
Damien Miller | 38d9a96 | 2010-10-07 22:07:11 +1100 | [diff] [blame] | 1445 | if ((shell = getenv("SHELL")) == NULL || *shell == '\0') |
Damien Miller | d27b947 | 2005-12-13 19:29:02 +1100 | [diff] [blame] | 1446 | shell = _PATH_BSHELL; |
| 1447 | |
Damien Miller | ed3a8eb | 2011-01-07 10:02:52 +1100 | [diff] [blame] | 1448 | osighand = signal(SIGCHLD, SIG_DFL); |
Damien Miller | d27b947 | 2005-12-13 19:29:02 +1100 | [diff] [blame] | 1449 | pid = fork(); |
| 1450 | if (pid == 0) { |
Damien Miller | 6fb6fd5 | 2011-01-16 23:17:45 +1100 | [diff] [blame] | 1451 | signal(SIGPIPE, SIG_DFL); |
Damien Miller | d27b947 | 2005-12-13 19:29:02 +1100 | [diff] [blame] | 1452 | debug3("Executing %s -c \"%s\"", shell, args); |
| 1453 | execl(shell, shell, "-c", args, (char *)NULL); |
| 1454 | error("Couldn't execute %s -c \"%s\": %s", |
| 1455 | shell, args, strerror(errno)); |
| 1456 | _exit(1); |
| 1457 | } else if (pid == -1) |
| 1458 | fatal("fork failed: %.100s", strerror(errno)); |
| 1459 | while (waitpid(pid, &status, 0) == -1) |
| 1460 | if (errno != EINTR) |
| 1461 | fatal("Couldn't wait for child: %s", strerror(errno)); |
Damien Miller | ed3a8eb | 2011-01-07 10:02:52 +1100 | [diff] [blame] | 1462 | signal(SIGCHLD, osighand); |
Damien Miller | d27b947 | 2005-12-13 19:29:02 +1100 | [diff] [blame] | 1463 | |
| 1464 | if (!WIFEXITED(status)) |
| 1465 | return (1); |
| 1466 | |
| 1467 | return (WEXITSTATUS(status)); |
| 1468 | } |
jcs@openbsd.org | f361df4 | 2015-11-15 22:26:49 +0000 | [diff] [blame] | 1469 | |
| 1470 | void |
markus@openbsd.org | 54d90ac | 2017-05-30 08:52:19 +0000 | [diff] [blame] | 1471 | maybe_add_key_to_agent(char *authfile, struct sshkey *private, char *comment, |
jcs@openbsd.org | f361df4 | 2015-11-15 22:26:49 +0000 | [diff] [blame] | 1472 | char *passphrase) |
| 1473 | { |
| 1474 | int auth_sock = -1, r; |
| 1475 | |
| 1476 | if (options.add_keys_to_agent == 0) |
| 1477 | return; |
| 1478 | |
| 1479 | if ((r = ssh_get_authentication_socket(&auth_sock)) != 0) { |
| 1480 | debug3("no authentication agent, not adding key"); |
| 1481 | return; |
| 1482 | } |
| 1483 | |
| 1484 | if (options.add_keys_to_agent == 2 && |
| 1485 | !ask_permission("Add key %s (%s) to agent?", authfile, comment)) { |
| 1486 | debug3("user denied adding this key"); |
dtucker@openbsd.org | 566b3a4 | 2017-03-10 03:22:40 +0000 | [diff] [blame] | 1487 | close(auth_sock); |
jcs@openbsd.org | f361df4 | 2015-11-15 22:26:49 +0000 | [diff] [blame] | 1488 | return; |
| 1489 | } |
| 1490 | |
| 1491 | if ((r = ssh_add_identity_constrained(auth_sock, private, comment, 0, |
| 1492 | (options.add_keys_to_agent == 3))) == 0) |
| 1493 | debug("identity added to agent: %s", authfile); |
| 1494 | else |
| 1495 | debug("could not add identity to agent: %s (%d)", authfile, r); |
dtucker@openbsd.org | 566b3a4 | 2017-03-10 03:22:40 +0000 | [diff] [blame] | 1496 | close(auth_sock); |
jcs@openbsd.org | f361df4 | 2015-11-15 22:26:49 +0000 | [diff] [blame] | 1497 | } |