markus@openbsd.org | fc77ccd | 2016-01-14 22:56:56 +0000 | [diff] [blame] | 1 | /* $OpenBSD: sshconnect.c,v 1.271 2016/01/14 22:56:56 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 | |
deraadt@openbsd.org | 087266e | 2015-01-20 23:14:00 +0000 | [diff] [blame] | 18 | #include <sys/param.h> /* roundup */ |
Damien Miller | 9cf6d07 | 2006-03-15 11:29:24 +1100 | [diff] [blame] | 19 | #include <sys/types.h> |
| 20 | #include <sys/wait.h> |
Damien Miller | f17883e | 2006-03-15 11:45:54 +1100 | [diff] [blame] | 21 | #include <sys/stat.h> |
Damien Miller | 8ec8c3e | 2006-07-10 20:35:38 +1000 | [diff] [blame] | 22 | #include <sys/socket.h> |
Damien Miller | 9aec919 | 2006-08-05 10:57:45 +1000 | [diff] [blame] | 23 | #ifdef HAVE_SYS_TIME_H |
| 24 | # include <sys/time.h> |
| 25 | #endif |
Damien Miller | 8ec8c3e | 2006-07-10 20:35:38 +1000 | [diff] [blame] | 26 | |
| 27 | #include <netinet/in.h> |
Darren Tucker | 46aa3e0 | 2006-09-02 15:32:40 +1000 | [diff] [blame] | 28 | #include <arpa/inet.h> |
Damien Miller | 03e2003 | 2006-03-15 11:16:59 +1100 | [diff] [blame] | 29 | |
Damien Miller | c7b0636 | 2006-03-15 11:53:45 +1100 | [diff] [blame] | 30 | #include <ctype.h> |
Darren Tucker | 3997249 | 2006-07-12 22:22:46 +1000 | [diff] [blame] | 31 | #include <errno.h> |
Darren Tucker | 6e7fe1c | 2010-01-08 17:07:22 +1100 | [diff] [blame] | 32 | #include <fcntl.h> |
Damien Miller | b8fe89c | 2006-07-24 14:51:00 +1000 | [diff] [blame] | 33 | #include <netdb.h> |
Damien Miller | 6645e7a | 2006-03-15 14:42:54 +1100 | [diff] [blame] | 34 | #ifdef HAVE_PATHS_H |
Damien Miller | 03e2003 | 2006-03-15 11:16:59 +1100 | [diff] [blame] | 35 | #include <paths.h> |
Damien Miller | 6645e7a | 2006-03-15 14:42:54 +1100 | [diff] [blame] | 36 | #endif |
Damien Miller | 9f2abc4 | 2006-07-10 20:53:08 +1000 | [diff] [blame] | 37 | #include <pwd.h> |
Damien Miller | 9c0c31d | 2010-10-12 13:30:44 +1100 | [diff] [blame] | 38 | #include <signal.h> |
Damien Miller | ded319c | 2006-09-01 15:38:36 +1000 | [diff] [blame] | 39 | #include <stdarg.h> |
Damien Miller | a7a73ee | 2006-08-05 11:37:59 +1000 | [diff] [blame] | 40 | #include <stdio.h> |
Damien Miller | e7a1e5c | 2006-08-05 11:34:19 +1000 | [diff] [blame] | 41 | #include <stdlib.h> |
Damien Miller | e3476ed | 2006-07-24 14:13:33 +1000 | [diff] [blame] | 42 | #include <string.h> |
Damien Miller | e6b3b61 | 2006-07-24 14:01:23 +1000 | [diff] [blame] | 43 | #include <unistd.h> |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 44 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 45 | #include "xmalloc.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 46 | #include "key.h" |
| 47 | #include "hostfile.h" |
| 48 | #include "ssh.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 49 | #include "rsa.h" |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 50 | #include "buffer.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 51 | #include "packet.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 52 | #include "uidswap.h" |
| 53 | #include "compat.h" |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 54 | #include "key.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 55 | #include "sshconnect.h" |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 56 | #include "hostfile.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 57 | #include "log.h" |
Damien Miller | 7acefbb | 2014-07-18 14:11:24 +1000 | [diff] [blame] | 58 | #include "misc.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 59 | #include "readconf.h" |
| 60 | #include "atomicio.h" |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 61 | #include "dns.h" |
Damien Miller | 1262b66 | 2013-08-21 02:44:24 +1000 | [diff] [blame] | 62 | #include "monitor_fdpass.h" |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 63 | #include "ssh2.h" |
Damien Miller | b757677 | 2006-07-10 20:23:39 +1000 | [diff] [blame] | 64 | #include "version.h" |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 65 | #include "authfile.h" |
| 66 | #include "ssherr.h" |
jcs@openbsd.org | f361df4 | 2015-11-15 22:26:49 +0000 | [diff] [blame] | 67 | #include "authfd.h" |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 68 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 69 | char *client_version_string = NULL; |
| 70 | char *server_version_string = NULL; |
Damien Miller | 6b37fbb | 2014-07-04 08:59:24 +1000 | [diff] [blame] | 71 | Key *previous_host_key = NULL; |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 72 | |
Damien Miller | c1af1d5 | 2005-11-05 15:08:57 +1100 | [diff] [blame] | 73 | static int matching_host_key_dns = 0; |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 74 | |
Damien Miller | a41ccca | 2010-10-07 22:07:32 +1100 | [diff] [blame] | 75 | static pid_t proxy_command_pid = 0; |
| 76 | |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 77 | /* import */ |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 78 | extern Options options; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 79 | extern char *__progname; |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 80 | extern uid_t original_real_uid; |
| 81 | extern uid_t original_effective_uid; |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 82 | |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 83 | static int show_other_keys(struct hostkeys *, Key *); |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 84 | static void warn_changed_key(Key *); |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 85 | |
Damien Miller | 1262b66 | 2013-08-21 02:44:24 +1000 | [diff] [blame] | 86 | /* Expand a proxy command */ |
| 87 | static char * |
| 88 | expand_proxy_command(const char *proxy_command, const char *user, |
| 89 | const char *host, int port) |
| 90 | { |
| 91 | char *tmp, *ret, strport[NI_MAXSERV]; |
| 92 | |
Damien Miller | 0faf747 | 2013-10-17 11:47:23 +1100 | [diff] [blame] | 93 | snprintf(strport, sizeof strport, "%d", port); |
Damien Miller | 1262b66 | 2013-08-21 02:44:24 +1000 | [diff] [blame] | 94 | xasprintf(&tmp, "exec %s", proxy_command); |
| 95 | ret = percent_expand(tmp, "h", host, "p", strport, |
| 96 | "r", options.user, (char *)NULL); |
| 97 | free(tmp); |
| 98 | return ret; |
| 99 | } |
| 100 | |
| 101 | /* |
| 102 | * Connect to the given ssh server using a proxy command that passes a |
| 103 | * a connected fd back to us. |
| 104 | */ |
| 105 | static int |
| 106 | ssh_proxy_fdpass_connect(const char *host, u_short port, |
| 107 | const char *proxy_command) |
| 108 | { |
| 109 | char *command_string; |
| 110 | int sp[2], sock; |
| 111 | pid_t pid; |
| 112 | char *shell; |
| 113 | |
| 114 | if ((shell = getenv("SHELL")) == NULL) |
| 115 | shell = _PATH_BSHELL; |
| 116 | |
| 117 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, sp) < 0) |
| 118 | fatal("Could not create socketpair to communicate with " |
| 119 | "proxy dialer: %.100s", strerror(errno)); |
| 120 | |
| 121 | command_string = expand_proxy_command(proxy_command, options.user, |
| 122 | host, port); |
| 123 | debug("Executing proxy dialer command: %.500s", command_string); |
| 124 | |
| 125 | /* Fork and execute the proxy command. */ |
| 126 | if ((pid = fork()) == 0) { |
| 127 | char *argv[10]; |
| 128 | |
| 129 | /* Child. Permanently give up superuser privileges. */ |
| 130 | permanently_drop_suid(original_real_uid); |
| 131 | |
| 132 | close(sp[1]); |
| 133 | /* Redirect stdin and stdout. */ |
| 134 | if (sp[0] != 0) { |
| 135 | if (dup2(sp[0], 0) < 0) |
| 136 | perror("dup2 stdin"); |
| 137 | } |
| 138 | if (sp[0] != 1) { |
| 139 | if (dup2(sp[0], 1) < 0) |
| 140 | perror("dup2 stdout"); |
| 141 | } |
| 142 | if (sp[0] >= 2) |
| 143 | close(sp[0]); |
| 144 | |
| 145 | /* |
| 146 | * Stderr is left as it is so that error messages get |
| 147 | * printed on the user's terminal. |
| 148 | */ |
| 149 | argv[0] = shell; |
| 150 | argv[1] = "-c"; |
| 151 | argv[2] = command_string; |
| 152 | argv[3] = NULL; |
| 153 | |
| 154 | /* |
| 155 | * Execute the proxy command. |
| 156 | * Note that we gave up any extra privileges above. |
| 157 | */ |
| 158 | execv(argv[0], argv); |
| 159 | perror(argv[0]); |
| 160 | exit(1); |
| 161 | } |
| 162 | /* Parent. */ |
| 163 | if (pid < 0) |
| 164 | fatal("fork failed: %.100s", strerror(errno)); |
| 165 | close(sp[0]); |
| 166 | free(command_string); |
| 167 | |
| 168 | if ((sock = mm_receive_fd(sp[1])) == -1) |
| 169 | fatal("proxy dialer did not pass back a connection"); |
markus@openbsd.org | fc77ccd | 2016-01-14 22:56:56 +0000 | [diff] [blame] | 170 | close(sp[1]); |
Damien Miller | 1262b66 | 2013-08-21 02:44:24 +1000 | [diff] [blame] | 171 | |
| 172 | while (waitpid(pid, NULL, 0) == -1) |
| 173 | if (errno != EINTR) |
| 174 | fatal("Couldn't wait for child: %s", strerror(errno)); |
| 175 | |
| 176 | /* Set the connection file descriptors. */ |
| 177 | packet_set_connection(sock, sock); |
Damien Miller | 1262b66 | 2013-08-21 02:44:24 +1000 | [diff] [blame] | 178 | |
| 179 | return 0; |
| 180 | } |
| 181 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 182 | /* |
| 183 | * Connect to the given ssh server using a proxy command. |
| 184 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 185 | static int |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 186 | 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] | 187 | { |
Damien Miller | 1262b66 | 2013-08-21 02:44:24 +1000 | [diff] [blame] | 188 | char *command_string; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 189 | int pin[2], pout[2]; |
Damien Miller | 166fca8 | 2000-04-20 07:42:21 +1000 | [diff] [blame] | 190 | pid_t pid; |
Damien Miller | 1262b66 | 2013-08-21 02:44:24 +1000 | [diff] [blame] | 191 | char *shell; |
Damien Miller | 1d824ab | 2007-09-17 11:58:04 +1000 | [diff] [blame] | 192 | |
Damien Miller | 38d9a96 | 2010-10-07 22:07:11 +1100 | [diff] [blame] | 193 | if ((shell = getenv("SHELL")) == NULL || *shell == '\0') |
Damien Miller | 1d824ab | 2007-09-17 11:58:04 +1000 | [diff] [blame] | 194 | shell = _PATH_BSHELL; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 195 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 196 | /* Create pipes for communicating with the proxy. */ |
| 197 | if (pipe(pin) < 0 || pipe(pout) < 0) |
| 198 | fatal("Could not create pipes to communicate with the proxy: %.100s", |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 199 | strerror(errno)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 200 | |
Damien Miller | 1262b66 | 2013-08-21 02:44:24 +1000 | [diff] [blame] | 201 | command_string = expand_proxy_command(proxy_command, options.user, |
| 202 | host, port); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 203 | debug("Executing proxy command: %.500s", command_string); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 204 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 205 | /* Fork and execute the proxy command. */ |
| 206 | if ((pid = fork()) == 0) { |
| 207 | char *argv[10]; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 208 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 209 | /* Child. Permanently give up superuser privileges. */ |
Damien Miller | 2e5fe88 | 2006-06-13 13:10:00 +1000 | [diff] [blame] | 210 | permanently_drop_suid(original_real_uid); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 211 | |
| 212 | /* Redirect stdin and stdout. */ |
| 213 | close(pin[1]); |
| 214 | if (pin[0] != 0) { |
| 215 | if (dup2(pin[0], 0) < 0) |
| 216 | perror("dup2 stdin"); |
| 217 | close(pin[0]); |
| 218 | } |
| 219 | close(pout[0]); |
| 220 | if (dup2(pout[1], 1) < 0) |
| 221 | perror("dup2 stdout"); |
| 222 | /* Cannot be 1 because pin allocated two descriptors. */ |
| 223 | close(pout[1]); |
| 224 | |
| 225 | /* Stderr is left as it is so that error messages get |
| 226 | printed on the user's terminal. */ |
Damien Miller | 1d824ab | 2007-09-17 11:58:04 +1000 | [diff] [blame] | 227 | argv[0] = shell; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 228 | argv[1] = "-c"; |
| 229 | argv[2] = command_string; |
| 230 | argv[3] = NULL; |
| 231 | |
| 232 | /* Execute the proxy command. Note that we gave up any |
| 233 | extra privileges above. */ |
Damien Miller | 6fb6fd5 | 2011-01-16 23:17:45 +1100 | [diff] [blame] | 234 | signal(SIGPIPE, SIG_DFL); |
Kevin Steves | fcd5d60 | 2001-01-07 11:45:22 +0000 | [diff] [blame] | 235 | execv(argv[0], argv); |
| 236 | perror(argv[0]); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 237 | exit(1); |
| 238 | } |
| 239 | /* Parent. */ |
| 240 | if (pid < 0) |
| 241 | fatal("fork failed: %.100s", strerror(errno)); |
Damien Miller | 8c4e18a | 2002-09-19 12:05:02 +1000 | [diff] [blame] | 242 | else |
| 243 | proxy_command_pid = pid; /* save pid to clean up later */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 244 | |
| 245 | /* Close child side of the descriptors. */ |
| 246 | close(pin[0]); |
| 247 | close(pout[1]); |
| 248 | |
| 249 | /* Free the command name. */ |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 250 | free(command_string); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 251 | |
| 252 | /* Set the connection file descriptors. */ |
| 253 | packet_set_connection(pout[0], pin[1]); |
| 254 | |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 255 | /* Indicate OK return */ |
| 256 | return 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 257 | } |
| 258 | |
Damien Miller | a41ccca | 2010-10-07 22:07:32 +1100 | [diff] [blame] | 259 | void |
| 260 | ssh_kill_proxy_command(void) |
| 261 | { |
| 262 | /* |
| 263 | * Send SIGHUP to proxy command if used. We don't wait() in |
| 264 | * case it hangs and instead rely on init to reap the child |
| 265 | */ |
| 266 | if (proxy_command_pid > 1) |
Damien Miller | 45fcdaa | 2010-10-07 22:07:58 +1100 | [diff] [blame] | 267 | kill(proxy_command_pid, SIGHUP); |
Damien Miller | a41ccca | 2010-10-07 22:07:32 +1100 | [diff] [blame] | 268 | } |
| 269 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 270 | /* |
| 271 | * Creates a (possibly privileged) socket for use as the ssh connection. |
| 272 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 273 | static int |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 274 | ssh_create_socket(int privileged, struct addrinfo *ai) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 275 | { |
Darren Tucker | e6e52f8 | 2013-10-10 10:28:07 +1100 | [diff] [blame] | 276 | int sock, r, gaierr; |
Damien Miller | d1a7a9c | 2014-02-07 09:24:33 +1100 | [diff] [blame] | 277 | struct addrinfo hints, *res = NULL; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 278 | |
Darren Tucker | 7bd98e7 | 2010-01-10 10:31:12 +1100 | [diff] [blame] | 279 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
Darren Tucker | 6e7fe1c | 2010-01-08 17:07:22 +1100 | [diff] [blame] | 280 | if (sock < 0) { |
Darren Tucker | e6e52f8 | 2013-10-10 10:28:07 +1100 | [diff] [blame] | 281 | error("socket: %s", strerror(errno)); |
Darren Tucker | 6e7fe1c | 2010-01-08 17:07:22 +1100 | [diff] [blame] | 282 | return -1; |
| 283 | } |
| 284 | fcntl(sock, F_SETFD, FD_CLOEXEC); |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 285 | |
| 286 | /* Bind the socket to an alternative local IP address */ |
Darren Tucker | e6e52f8 | 2013-10-10 10:28:07 +1100 | [diff] [blame] | 287 | if (options.bind_address == NULL && !privileged) |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 288 | return sock; |
| 289 | |
Damien Miller | d1a7a9c | 2014-02-07 09:24:33 +1100 | [diff] [blame] | 290 | if (options.bind_address) { |
| 291 | memset(&hints, 0, sizeof(hints)); |
| 292 | hints.ai_family = ai->ai_family; |
| 293 | hints.ai_socktype = ai->ai_socktype; |
| 294 | hints.ai_protocol = ai->ai_protocol; |
| 295 | hints.ai_flags = AI_PASSIVE; |
| 296 | gaierr = getaddrinfo(options.bind_address, NULL, &hints, &res); |
| 297 | if (gaierr) { |
| 298 | error("getaddrinfo: %s: %s", options.bind_address, |
| 299 | ssh_gai_strerror(gaierr)); |
| 300 | close(sock); |
| 301 | return -1; |
| 302 | } |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 303 | } |
Darren Tucker | e6e52f8 | 2013-10-10 10:28:07 +1100 | [diff] [blame] | 304 | /* |
| 305 | * If we are running as root and want to connect to a privileged |
| 306 | * port, bind our own socket to a privileged port. |
| 307 | */ |
| 308 | if (privileged) { |
| 309 | PRIV_START; |
Damien Miller | d1a7a9c | 2014-02-07 09:24:33 +1100 | [diff] [blame] | 310 | r = bindresvport_sa(sock, res ? res->ai_addr : NULL); |
Darren Tucker | e6e52f8 | 2013-10-10 10:28:07 +1100 | [diff] [blame] | 311 | PRIV_END; |
| 312 | if (r < 0) { |
| 313 | error("bindresvport_sa: af=%d %s", ai->ai_family, |
| 314 | strerror(errno)); |
| 315 | goto fail; |
| 316 | } |
| 317 | } else { |
| 318 | if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) { |
| 319 | error("bind: %s: %s", options.bind_address, |
| 320 | strerror(errno)); |
| 321 | fail: |
| 322 | close(sock); |
| 323 | freeaddrinfo(res); |
| 324 | return -1; |
| 325 | } |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 326 | } |
Damien Miller | d1a7a9c | 2014-02-07 09:24:33 +1100 | [diff] [blame] | 327 | if (res != NULL) |
| 328 | freeaddrinfo(res); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 329 | return sock; |
| 330 | } |
| 331 | |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 332 | static int |
| 333 | timeout_connect(int sockfd, const struct sockaddr *serv_addr, |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 334 | socklen_t addrlen, int *timeoutp) |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 335 | { |
| 336 | fd_set *fdset; |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 337 | struct timeval tv, t_start; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 338 | socklen_t optlen; |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 339 | int optval, rc, result = -1; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 340 | |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 341 | gettimeofday(&t_start, NULL); |
| 342 | |
| 343 | if (*timeoutp <= 0) { |
| 344 | result = connect(sockfd, serv_addr, addrlen); |
| 345 | goto done; |
| 346 | } |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 347 | |
Damien Miller | f6723f0 | 2004-01-27 21:21:27 +1100 | [diff] [blame] | 348 | set_nonblock(sockfd); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 349 | rc = connect(sockfd, serv_addr, addrlen); |
Damien Miller | f6723f0 | 2004-01-27 21:21:27 +1100 | [diff] [blame] | 350 | if (rc == 0) { |
| 351 | unset_nonblock(sockfd); |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 352 | result = 0; |
| 353 | goto done; |
Damien Miller | f6723f0 | 2004-01-27 21:21:27 +1100 | [diff] [blame] | 354 | } |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 355 | if (errno != EINPROGRESS) { |
| 356 | result = -1; |
| 357 | goto done; |
| 358 | } |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 359 | |
deraadt@openbsd.org | ce445b0 | 2015-08-20 22:32:42 +0000 | [diff] [blame] | 360 | fdset = xcalloc(howmany(sockfd + 1, NFDBITS), |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 361 | sizeof(fd_mask)); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 362 | FD_SET(sockfd, fdset); |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 363 | ms_to_timeval(&tv, *timeoutp); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 364 | |
Darren Tucker | 47eede7 | 2005-03-14 23:08:12 +1100 | [diff] [blame] | 365 | for (;;) { |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 366 | rc = select(sockfd + 1, NULL, fdset, NULL, &tv); |
| 367 | if (rc != -1 || errno != EINTR) |
| 368 | break; |
| 369 | } |
| 370 | |
Darren Tucker | 47eede7 | 2005-03-14 23:08:12 +1100 | [diff] [blame] | 371 | switch (rc) { |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 372 | case 0: |
| 373 | /* Timed out */ |
| 374 | errno = ETIMEDOUT; |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 375 | break; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 376 | case -1: |
| 377 | /* Select error */ |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 378 | debug("select: %s", strerror(errno)); |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 379 | break; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 380 | case 1: |
| 381 | /* Completed or failed */ |
| 382 | optval = 0; |
| 383 | optlen = sizeof(optval); |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 384 | if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, |
Darren Tucker | bd5361b | 2003-09-22 20:59:16 +1000 | [diff] [blame] | 385 | &optlen) == -1) { |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 386 | debug("getsockopt: %s", strerror(errno)); |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 387 | break; |
Darren Tucker | bd5361b | 2003-09-22 20:59:16 +1000 | [diff] [blame] | 388 | } |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 389 | if (optval != 0) { |
| 390 | errno = optval; |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 391 | break; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 392 | } |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 393 | result = 0; |
Damien Miller | f6723f0 | 2004-01-27 21:21:27 +1100 | [diff] [blame] | 394 | unset_nonblock(sockfd); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 395 | break; |
| 396 | default: |
| 397 | /* Should not occur */ |
| 398 | fatal("Bogus return (%d) from select()", rc); |
| 399 | } |
| 400 | |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 401 | free(fdset); |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 402 | |
| 403 | done: |
| 404 | if (result == 0 && *timeoutp > 0) { |
| 405 | ms_subtract_diff(&t_start, timeoutp); |
| 406 | if (*timeoutp <= 0) { |
| 407 | errno = ETIMEDOUT; |
| 408 | result = -1; |
| 409 | } |
| 410 | } |
| 411 | |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 412 | return (result); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 413 | } |
| 414 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 415 | /* |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 416 | * Opens a TCP/IP connection to the remote server on the given host. |
| 417 | * The address of the remote host will be returned in hostaddr. |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 418 | * 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] | 419 | * a privileged port will be allocated to make the connection. |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 420 | * This requires super-user privileges if needpriv is true. |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 421 | * Connection_attempts specifies the maximum number of tries (one per |
| 422 | * second). If proxy_command is non-NULL, it specifies the command (with %h |
| 423 | * and %p substituted for host and port, respectively) to use to contact |
| 424 | * the daemon. |
| 425 | */ |
Damien Miller | 0faf747 | 2013-10-17 11:47:23 +1100 | [diff] [blame] | 426 | static int |
| 427 | ssh_connect_direct(const char *host, struct addrinfo *aitop, |
| 428 | struct sockaddr_storage *hostaddr, u_short port, int family, |
| 429 | int connection_attempts, int *timeout_ms, int want_keepalive, int needpriv) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 430 | { |
Ben Lindstrom | bf555ba | 2001-01-18 02:04:35 +0000 | [diff] [blame] | 431 | int on = 1; |
| 432 | int sock = -1, attempt; |
| 433 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
Damien Miller | 0faf747 | 2013-10-17 11:47:23 +1100 | [diff] [blame] | 434 | struct addrinfo *ai; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 435 | |
djm@openbsd.org | 46152af | 2015-09-04 04:55:24 +0000 | [diff] [blame] | 436 | debug2("%s: needpriv %d", __func__, needpriv); |
djm@openbsd.org | 88b6fcd | 2015-11-19 08:23:27 +0000 | [diff] [blame] | 437 | memset(ntop, 0, sizeof(ntop)); |
| 438 | memset(strport, 0, sizeof(strport)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 439 | |
Damien Miller | 56e5e6a | 2006-04-23 12:08:59 +1000 | [diff] [blame] | 440 | for (attempt = 0; attempt < connection_attempts; attempt++) { |
Damien Miller | f4bcd10 | 2006-10-24 03:02:23 +1000 | [diff] [blame] | 441 | if (attempt > 0) { |
| 442 | /* Sleep a moment before retrying. */ |
| 443 | sleep(1); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 444 | debug("Trying again..."); |
Damien Miller | f4bcd10 | 2006-10-24 03:02:23 +1000 | [diff] [blame] | 445 | } |
Damien Miller | 56e5e6a | 2006-04-23 12:08:59 +1000 | [diff] [blame] | 446 | /* |
| 447 | * Loop through addresses for this host, and try each one in |
| 448 | * sequence until the connection succeeds. |
| 449 | */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 450 | for (ai = aitop; ai; ai = ai->ai_next) { |
Damien Miller | 0faf747 | 2013-10-17 11:47:23 +1100 | [diff] [blame] | 451 | if (ai->ai_family != AF_INET && |
| 452 | ai->ai_family != AF_INET6) |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 453 | continue; |
| 454 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, |
| 455 | ntop, sizeof(ntop), strport, sizeof(strport), |
| 456 | NI_NUMERICHOST|NI_NUMERICSERV) != 0) { |
djm@openbsd.org | 46152af | 2015-09-04 04:55:24 +0000 | [diff] [blame] | 457 | error("%s: getnameinfo failed", __func__); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 458 | continue; |
| 459 | } |
| 460 | debug("Connecting to %.200s [%.100s] port %s.", |
| 461 | host, ntop, strport); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 462 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 463 | /* Create a socket for connecting. */ |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 464 | sock = ssh_create_socket(needpriv, ai); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 465 | if (sock < 0) |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 466 | /* Any error is already output */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 467 | continue; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 468 | |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 469 | if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen, |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 470 | timeout_ms) >= 0) { |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 471 | /* Successful connection. */ |
Ben Lindstrom | a370005 | 2001-04-05 23:26:32 +0000 | [diff] [blame] | 472 | memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 473 | break; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 474 | } else { |
Ben Lindstrom | 728aa7e | 2002-07-15 17:48:11 +0000 | [diff] [blame] | 475 | debug("connect to address %s port %s: %s", |
| 476 | ntop, strport, strerror(errno)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 477 | close(sock); |
Damien Miller | 56e5e6a | 2006-04-23 12:08:59 +1000 | [diff] [blame] | 478 | sock = -1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 479 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 480 | } |
Damien Miller | 56e5e6a | 2006-04-23 12:08:59 +1000 | [diff] [blame] | 481 | if (sock != -1) |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 482 | break; /* Successful connection. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 483 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 484 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 485 | /* Return failure if we didn't get a successful connection. */ |
Damien Miller | 56e5e6a | 2006-04-23 12:08:59 +1000 | [diff] [blame] | 486 | if (sock == -1) { |
Darren Tucker | b2161e3 | 2005-01-20 11:00:46 +1100 | [diff] [blame] | 487 | error("ssh: connect to host %s port %s: %s", |
Ben Lindstrom | a6cd75c | 2002-07-11 04:00:19 +0000 | [diff] [blame] | 488 | host, strport, strerror(errno)); |
Darren Tucker | b2161e3 | 2005-01-20 11:00:46 +1100 | [diff] [blame] | 489 | return (-1); |
Ben Lindstrom | a6cd75c | 2002-07-11 04:00:19 +0000 | [diff] [blame] | 490 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 491 | |
| 492 | debug("Connection established."); |
| 493 | |
Damien Miller | 12c150e | 2003-12-17 16:31:10 +1100 | [diff] [blame] | 494 | /* Set SO_KEEPALIVE if requested. */ |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 495 | if (want_keepalive && |
Ben Lindstrom | bf555ba | 2001-01-18 02:04:35 +0000 | [diff] [blame] | 496 | setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, |
| 497 | sizeof(on)) < 0) |
| 498 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 499 | |
| 500 | /* Set the connection. */ |
| 501 | packet_set_connection(sock, sock); |
| 502 | |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 503 | return 0; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 504 | } |
| 505 | |
Damien Miller | 0faf747 | 2013-10-17 11:47:23 +1100 | [diff] [blame] | 506 | int |
| 507 | ssh_connect(const char *host, struct addrinfo *addrs, |
| 508 | struct sockaddr_storage *hostaddr, u_short port, int family, |
| 509 | int connection_attempts, int *timeout_ms, int want_keepalive, int needpriv) |
| 510 | { |
| 511 | if (options.proxy_command == NULL) { |
| 512 | return ssh_connect_direct(host, addrs, hostaddr, port, family, |
| 513 | connection_attempts, timeout_ms, want_keepalive, needpriv); |
| 514 | } else if (strcmp(options.proxy_command, "-") == 0) { |
| 515 | packet_set_connection(STDIN_FILENO, STDOUT_FILENO); |
| 516 | return 0; /* Always succeeds */ |
| 517 | } else if (options.proxy_use_fdpass) { |
| 518 | return ssh_proxy_fdpass_connect(host, port, |
| 519 | options.proxy_command); |
| 520 | } |
| 521 | return ssh_proxy_connect(host, port, options.proxy_command); |
| 522 | } |
| 523 | |
Darren Tucker | 00c1518 | 2012-09-06 21:21:56 +1000 | [diff] [blame] | 524 | static void |
| 525 | send_client_banner(int connection_out, int minor1) |
| 526 | { |
Darren Tucker | 00c1518 | 2012-09-06 21:21:56 +1000 | [diff] [blame] | 527 | /* Send our own protocol version identification. */ |
| 528 | if (compat20) { |
| 529 | xasprintf(&client_version_string, "SSH-%d.%d-%.100s\r\n", |
| 530 | PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2, SSH_VERSION); |
| 531 | } else { |
| 532 | xasprintf(&client_version_string, "SSH-%d.%d-%.100s\n", |
| 533 | PROTOCOL_MAJOR_1, minor1, SSH_VERSION); |
| 534 | } |
markus@openbsd.org | a306863 | 2016-01-14 16:17:39 +0000 | [diff] [blame] | 535 | if (atomicio(vwrite, connection_out, client_version_string, |
Darren Tucker | 00c1518 | 2012-09-06 21:21:56 +1000 | [diff] [blame] | 536 | strlen(client_version_string)) != strlen(client_version_string)) |
| 537 | fatal("write: %.100s", strerror(errno)); |
| 538 | chop(client_version_string); |
| 539 | debug("Local version string %.100s", client_version_string); |
| 540 | } |
| 541 | |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 542 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 543 | * Waits for the server identification string, and sends our own |
| 544 | * identification string. |
| 545 | */ |
Darren Tucker | 1cc55d7 | 2009-06-21 18:17:19 +1000 | [diff] [blame] | 546 | void |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 547 | ssh_exchange_identification(int timeout_ms) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 548 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 549 | char buf[256], remote_version[256]; /* must be same size! */ |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 550 | int remote_major, remote_minor, mismatch; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 551 | int connection_in = packet_get_connection_in(); |
| 552 | int connection_out = packet_get_connection_out(); |
Darren Tucker | 00c1518 | 2012-09-06 21:21:56 +1000 | [diff] [blame] | 553 | int minor1 = PROTOCOL_MINOR_1, client_banner_sent = 0; |
Damien Miller | 1e88ea6 | 2006-07-10 20:15:56 +1000 | [diff] [blame] | 554 | u_int i, n; |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 555 | size_t len; |
| 556 | int fdsetsz, remaining, rc; |
| 557 | struct timeval t_start, t_remaining; |
| 558 | fd_set *fdset; |
| 559 | |
| 560 | fdsetsz = howmany(connection_in + 1, NFDBITS) * sizeof(fd_mask); |
| 561 | fdset = xcalloc(1, fdsetsz); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 562 | |
Darren Tucker | 00c1518 | 2012-09-06 21:21:56 +1000 | [diff] [blame] | 563 | /* |
| 564 | * If we are SSH2-only then we can send the banner immediately and |
| 565 | * save a round-trip. |
| 566 | */ |
| 567 | if (options.protocol == SSH_PROTO_2) { |
| 568 | enable_compat20(); |
| 569 | send_client_banner(connection_out, 0); |
| 570 | client_banner_sent = 1; |
| 571 | } |
| 572 | |
Damien Miller | b253cc4 | 2005-05-26 12:23:44 +1000 | [diff] [blame] | 573 | /* Read other side's version identification. */ |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 574 | remaining = timeout_ms; |
Damien Miller | 1e88ea6 | 2006-07-10 20:15:56 +1000 | [diff] [blame] | 575 | for (n = 0;;) { |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 576 | for (i = 0; i < sizeof(buf) - 1; i++) { |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 577 | if (timeout_ms > 0) { |
| 578 | gettimeofday(&t_start, NULL); |
| 579 | ms_to_timeval(&t_remaining, remaining); |
| 580 | FD_SET(connection_in, fdset); |
| 581 | rc = select(connection_in + 1, fdset, NULL, |
| 582 | fdset, &t_remaining); |
| 583 | ms_subtract_diff(&t_start, &remaining); |
| 584 | if (rc == 0 || remaining <= 0) |
| 585 | fatal("Connection timed out during " |
| 586 | "banner exchange"); |
| 587 | if (rc == -1) { |
| 588 | if (errno == EINTR) |
| 589 | continue; |
| 590 | fatal("ssh_exchange_identification: " |
| 591 | "select: %s", strerror(errno)); |
| 592 | } |
| 593 | } |
| 594 | |
markus@openbsd.org | a306863 | 2016-01-14 16:17:39 +0000 | [diff] [blame] | 595 | len = atomicio(read, connection_in, &buf[i], 1); |
Damien Miller | b253cc4 | 2005-05-26 12:23:44 +1000 | [diff] [blame] | 596 | |
Damien Miller | 46d38de | 2005-07-17 17:02:09 +1000 | [diff] [blame] | 597 | if (len != 1 && errno == EPIPE) |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 598 | fatal("ssh_exchange_identification: " |
| 599 | "Connection closed by remote host"); |
Damien Miller | b253cc4 | 2005-05-26 12:23:44 +1000 | [diff] [blame] | 600 | else if (len != 1) |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 601 | fatal("ssh_exchange_identification: " |
| 602 | "read: %.100s", strerror(errno)); |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 603 | if (buf[i] == '\r') { |
| 604 | buf[i] = '\n'; |
| 605 | buf[i + 1] = 0; |
| 606 | continue; /**XXX wait for \n */ |
| 607 | } |
| 608 | if (buf[i] == '\n') { |
| 609 | buf[i + 1] = 0; |
| 610 | break; |
| 611 | } |
Damien Miller | 1e88ea6 | 2006-07-10 20:15:56 +1000 | [diff] [blame] | 612 | if (++n > 65536) |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 613 | fatal("ssh_exchange_identification: " |
| 614 | "No banner received"); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 615 | } |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 616 | buf[sizeof(buf) - 1] = 0; |
| 617 | if (strncmp(buf, "SSH-", 4) == 0) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 618 | break; |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 619 | debug("ssh_exchange_identification: %s", buf); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 620 | } |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 621 | server_version_string = xstrdup(buf); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 622 | free(fdset); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 623 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 624 | /* |
| 625 | * Check that the versions match. In future this might accept |
| 626 | * several versions and set appropriate flags to handle them. |
| 627 | */ |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 628 | if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n", |
| 629 | &remote_major, &remote_minor, remote_version) != 3) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 630 | fatal("Bad remote protocol version identification: '%.100s'", buf); |
| 631 | debug("Remote protocol version %d.%d, remote software version %.100s", |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 632 | remote_major, remote_minor, remote_version); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 633 | |
markus@openbsd.org | 48b3b2b | 2015-01-19 20:20:20 +0000 | [diff] [blame] | 634 | active_state->compat = compat_datafellows(remote_version); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 635 | mismatch = 0; |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 636 | |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 637 | switch (remote_major) { |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 638 | case 1: |
| 639 | if (remote_minor == 99 && |
| 640 | (options.protocol & SSH_PROTO_2) && |
| 641 | !(options.protocol & SSH_PROTO_1_PREFERRED)) { |
| 642 | enable_compat20(); |
| 643 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 644 | } |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 645 | if (!(options.protocol & SSH_PROTO_1)) { |
| 646 | mismatch = 1; |
| 647 | break; |
| 648 | } |
| 649 | if (remote_minor < 3) { |
| 650 | fatal("Remote machine has too old SSH software version."); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 651 | } else if (remote_minor == 3 || remote_minor == 4) { |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 652 | /* We speak 1.3, too. */ |
| 653 | enable_compat13(); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 654 | minor1 = 3; |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 655 | if (options.forward_agent) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 656 | logit("Agent forwarding disabled for protocol 1.3"); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 657 | options.forward_agent = 0; |
| 658 | } |
| 659 | } |
| 660 | break; |
| 661 | case 2: |
| 662 | if (options.protocol & SSH_PROTO_2) { |
| 663 | enable_compat20(); |
| 664 | break; |
| 665 | } |
| 666 | /* FALLTHROUGH */ |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 667 | default: |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 668 | mismatch = 1; |
| 669 | break; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 670 | } |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 671 | if (mismatch) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 672 | fatal("Protocol major versions differ: %d vs. %d", |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 673 | (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
| 674 | remote_major); |
Damien Miller | 58cd63b | 2014-01-10 10:59:24 +1100 | [diff] [blame] | 675 | if ((datafellows & SSH_BUG_DERIVEKEY) != 0) |
| 676 | fatal("Server version \"%.100s\" uses unsafe key agreement; " |
| 677 | "refusing connection", remote_version); |
Damien Miller | 324541e | 2013-12-31 12:25:40 +1100 | [diff] [blame] | 678 | if ((datafellows & SSH_BUG_RSASIGMD5) != 0) |
| 679 | logit("Server version \"%.100s\" uses unsafe RSA signature " |
| 680 | "scheme; disabling use of RSA keys", remote_version); |
Darren Tucker | 00c1518 | 2012-09-06 21:21:56 +1000 | [diff] [blame] | 681 | if (!client_banner_sent) |
| 682 | send_client_banner(connection_out, minor1); |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 683 | chop(server_version_string); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 684 | } |
| 685 | |
Ben Lindstrom | b6c06d9 | 2001-02-10 23:21:09 +0000 | [diff] [blame] | 686 | /* defaults to 'no' */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 687 | static int |
Damien Miller | e398004 | 2001-10-10 15:02:03 +1000 | [diff] [blame] | 688 | confirm(const char *prompt) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 689 | { |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 690 | const char *msg, *again = "Please type 'yes' or 'no': "; |
| 691 | char *p; |
| 692 | int ret = -1; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 693 | |
Ben Lindstrom | b6c06d9 | 2001-02-10 23:21:09 +0000 | [diff] [blame] | 694 | if (options.batch_mode) |
| 695 | return 0; |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 696 | for (msg = prompt;;msg = again) { |
| 697 | p = read_passphrase(msg, RP_ECHO); |
| 698 | if (p == NULL || |
| 699 | (p[0] == '\0') || (p[0] == '\n') || |
| 700 | strncasecmp(p, "no", 2) == 0) |
| 701 | ret = 0; |
Ben Lindstrom | 04f9af7 | 2002-07-04 00:03:56 +0000 | [diff] [blame] | 702 | if (p && strncasecmp(p, "yes", 3) == 0) |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 703 | ret = 1; |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 704 | free(p); |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 705 | if (ret != -1) |
| 706 | return ret; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 707 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 708 | } |
| 709 | |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 710 | static int |
| 711 | check_host_cert(const char *host, const Key *host_key) |
| 712 | { |
| 713 | const char *reason; |
| 714 | |
| 715 | if (key_cert_check_authority(host_key, 1, 0, host, &reason) != 0) { |
| 716 | error("%s", reason); |
| 717 | return 0; |
| 718 | } |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 719 | if (buffer_len(host_key->cert->critical) != 0) { |
Damien Miller | 4e270b0 | 2010-04-16 15:56:21 +1000 | [diff] [blame] | 720 | error("Certificate for %s contains unsupported " |
| 721 | "critical options(s)", host); |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 722 | return 0; |
| 723 | } |
| 724 | return 1; |
| 725 | } |
| 726 | |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 727 | static int |
| 728 | sockaddr_is_local(struct sockaddr *hostaddr) |
| 729 | { |
| 730 | switch (hostaddr->sa_family) { |
| 731 | case AF_INET: |
| 732 | return (ntohl(((struct sockaddr_in *)hostaddr)-> |
| 733 | sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; |
| 734 | case AF_INET6: |
| 735 | return IN6_IS_ADDR_LOOPBACK( |
| 736 | &(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); |
| 737 | default: |
| 738 | return 0; |
| 739 | } |
| 740 | } |
| 741 | |
| 742 | /* |
| 743 | * Prepare the hostname and ip address strings that are used to lookup |
| 744 | * host keys in known_hosts files. These may have a port number appended. |
| 745 | */ |
| 746 | void |
| 747 | get_hostfile_hostname_ipaddr(char *hostname, struct sockaddr *hostaddr, |
| 748 | u_short port, char **hostfile_hostname, char **hostfile_ipaddr) |
| 749 | { |
| 750 | char ntop[NI_MAXHOST]; |
| 751 | socklen_t addrlen; |
| 752 | |
| 753 | switch (hostaddr == NULL ? -1 : hostaddr->sa_family) { |
| 754 | case -1: |
| 755 | addrlen = 0; |
| 756 | break; |
| 757 | case AF_INET: |
| 758 | addrlen = sizeof(struct sockaddr_in); |
| 759 | break; |
| 760 | case AF_INET6: |
| 761 | addrlen = sizeof(struct sockaddr_in6); |
| 762 | break; |
| 763 | default: |
| 764 | addrlen = sizeof(struct sockaddr); |
| 765 | break; |
| 766 | } |
| 767 | |
| 768 | /* |
| 769 | * We don't have the remote ip-address for connections |
| 770 | * using a proxy command |
| 771 | */ |
| 772 | if (hostfile_ipaddr != NULL) { |
| 773 | if (options.proxy_command == NULL) { |
| 774 | if (getnameinfo(hostaddr, addrlen, |
| 775 | ntop, sizeof(ntop), NULL, 0, NI_NUMERICHOST) != 0) |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 776 | fatal("%s: getnameinfo failed", __func__); |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 777 | *hostfile_ipaddr = put_host_port(ntop, port); |
| 778 | } else { |
| 779 | *hostfile_ipaddr = xstrdup("<no hostip for proxy " |
| 780 | "command>"); |
| 781 | } |
| 782 | } |
| 783 | |
| 784 | /* |
| 785 | * Allow the user to record the key under a different name or |
| 786 | * differentiate a non-standard port. This is useful for ssh |
| 787 | * tunneling over forwarded connections or if you run multiple |
| 788 | * sshd's on different ports on the same machine. |
| 789 | */ |
| 790 | if (hostfile_hostname != NULL) { |
| 791 | if (options.host_key_alias != NULL) { |
| 792 | *hostfile_hostname = xstrdup(options.host_key_alias); |
| 793 | debug("using hostkeyalias: %s", *hostfile_hostname); |
| 794 | } else { |
| 795 | *hostfile_hostname = put_host_port(hostname, port); |
| 796 | } |
| 797 | } |
| 798 | } |
| 799 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 800 | /* |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 801 | * 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] | 802 | * 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] | 803 | */ |
Damien Miller | da82839 | 2006-08-05 11:35:45 +1000 | [diff] [blame] | 804 | #define RDRW 0 |
| 805 | #define RDONLY 1 |
| 806 | #define ROQUIET 2 |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 807 | static int |
Damien Miller | da82839 | 2006-08-05 11:35:45 +1000 | [diff] [blame] | 808 | check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 809 | Key *host_key, int readonly, |
| 810 | char **user_hostfiles, u_int num_user_hostfiles, |
| 811 | char **system_hostfiles, u_int num_system_hostfiles) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 812 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 813 | HostStatus host_status; |
| 814 | HostStatus ip_status; |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 815 | Key *raw_key = NULL; |
| 816 | char *ip = NULL, *host = NULL; |
| 817 | char hostline[1000], *hostp, *fp, *ra; |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 818 | char msg[1024]; |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 819 | const char *type; |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 820 | const struct hostkey_entry *host_found, *ip_found; |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 821 | int len, cancelled_forwarding = 0; |
| 822 | int local = sockaddr_is_local(hostaddr); |
| 823 | int r, want_cert = key_is_cert(host_key), host_ip_differ = 0; |
djm@openbsd.org | 8d4f872 | 2015-01-26 03:04:45 +0000 | [diff] [blame] | 824 | int hostkey_trusted = 0; /* Known or explicitly accepted by user */ |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 825 | struct hostkeys *host_hostkeys, *ip_hostkeys; |
| 826 | u_int i; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 827 | |
| 828 | /* |
| 829 | * Force accepting of the host key for loopback/localhost. The |
| 830 | * problem is that if the home directory is NFS-mounted to multiple |
| 831 | * machines, localhost will refer to a different machine in each of |
| 832 | * them, and the user will get bogus HOST_CHANGED warnings. This |
| 833 | * essentially disables host authentication for localhost; however, |
| 834 | * this is probably not a real problem. |
| 835 | */ |
Ben Lindstrom | 3cecc9a | 2001-10-03 17:39:38 +0000 | [diff] [blame] | 836 | if (options.no_host_authentication_for_localhost == 1 && local && |
| 837 | options.host_key_alias == NULL) { |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 838 | debug("Forcing accepting of host key for " |
| 839 | "loopback/localhost."); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 840 | return 0; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 841 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 842 | |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 843 | /* |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 844 | * Prepare the hostname and address strings used for hostkey lookup. |
| 845 | * In some cases, these will have a port number appended. |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 846 | */ |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 847 | get_hostfile_hostname_ipaddr(hostname, hostaddr, port, &host, &ip); |
Darren Tucker | 78913e0 | 2008-06-13 04:47:34 +1000 | [diff] [blame] | 848 | |
| 849 | /* |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 850 | * Turn off check_host_ip if the connection is to localhost, via proxy |
| 851 | * command or if we don't have a hostname to compare with |
| 852 | */ |
Darren Tucker | da34553 | 2006-07-10 23:04:19 +1000 | [diff] [blame] | 853 | if (options.check_host_ip && (local || |
| 854 | strcmp(hostname, ip) == 0 || options.proxy_command != NULL)) |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 855 | options.check_host_ip = 0; |
| 856 | |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 857 | host_hostkeys = init_hostkeys(); |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 858 | for (i = 0; i < num_user_hostfiles; i++) |
| 859 | load_hostkeys(host_hostkeys, host, user_hostfiles[i]); |
| 860 | for (i = 0; i < num_system_hostfiles; i++) |
| 861 | load_hostkeys(host_hostkeys, host, system_hostfiles[i]); |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 862 | |
| 863 | ip_hostkeys = NULL; |
| 864 | if (!want_cert && options.check_host_ip) { |
| 865 | ip_hostkeys = init_hostkeys(); |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 866 | for (i = 0; i < num_user_hostfiles; i++) |
| 867 | load_hostkeys(ip_hostkeys, ip, user_hostfiles[i]); |
| 868 | for (i = 0; i < num_system_hostfiles; i++) |
| 869 | load_hostkeys(ip_hostkeys, ip, system_hostfiles[i]); |
Ben Lindstrom | 4dccfa5 | 2000-12-28 16:40:05 +0000 | [diff] [blame] | 870 | } |
| 871 | |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 872 | retry: |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 873 | /* Reload these as they may have changed on cert->key downgrade */ |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 874 | want_cert = key_is_cert(host_key); |
| 875 | type = key_type(host_key); |
| 876 | |
Ben Lindstrom | 4dccfa5 | 2000-12-28 16:40:05 +0000 | [diff] [blame] | 877 | /* |
Damien Miller | 788f212 | 2005-11-05 15:14:59 +1100 | [diff] [blame] | 878 | * 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] | 879 | * hosts or in the systemwide list. |
| 880 | */ |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 881 | host_status = check_key_in_hostkeys(host_hostkeys, host_key, |
| 882 | &host_found); |
| 883 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 884 | /* |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 885 | * 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] | 886 | * localhost, looking for a certificate, or the hostname was an ip |
| 887 | * address to begin with. |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 888 | */ |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 889 | if (!want_cert && ip_hostkeys != NULL) { |
| 890 | ip_status = check_key_in_hostkeys(ip_hostkeys, host_key, |
| 891 | &ip_found); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 892 | if (host_status == HOST_CHANGED && |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 893 | (ip_status != HOST_CHANGED || |
| 894 | (ip_found != NULL && |
| 895 | !key_equal(ip_found->key, host_found->key)))) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 896 | host_ip_differ = 1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 897 | } else |
| 898 | ip_status = host_status; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 899 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 900 | switch (host_status) { |
| 901 | case HOST_OK: |
| 902 | /* The host is known and the key matches. */ |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 903 | debug("Host '%.200s' is known and matches the %s host %s.", |
| 904 | host, type, want_cert ? "certificate" : "key"); |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 905 | debug("Found %s in %s:%lu", want_cert ? "CA key" : "key", |
| 906 | host_found->file, host_found->line); |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 907 | if (want_cert && !check_host_cert(hostname, host_key)) |
| 908 | goto fail; |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 909 | if (options.check_host_ip && ip_status == HOST_NEW) { |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 910 | if (readonly || want_cert) |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 911 | logit("%s host key for IP address " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 912 | "'%.128s' not in list of known hosts.", |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 913 | type, ip); |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 914 | else if (!add_host_to_hostfile(user_hostfiles[0], ip, |
Damien Miller | e177615 | 2005-03-01 21:47:37 +1100 | [diff] [blame] | 915 | host_key, options.hash_known_hosts)) |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 916 | logit("Failed to add the %s host key for IP " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 917 | "address '%.128s' to the list of known " |
dtucker@openbsd.org | 496aeb2 | 2015-05-28 05:41:29 +0000 | [diff] [blame] | 918 | "hosts (%.500s).", type, ip, |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 919 | user_hostfiles[0]); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 920 | else |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 921 | logit("Warning: Permanently added the %s host " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 922 | "key for IP address '%.128s' to the list " |
| 923 | "of known hosts.", type, ip); |
Damien Miller | 1028824 | 2008-06-30 00:04:03 +1000 | [diff] [blame] | 924 | } else if (options.visual_host_key) { |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 925 | fp = sshkey_fingerprint(host_key, |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 926 | options.fingerprint_hash, SSH_FP_DEFAULT); |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 927 | ra = sshkey_fingerprint(host_key, |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 928 | options.fingerprint_hash, SSH_FP_RANDOMART); |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 929 | if (fp == NULL || ra == NULL) |
| 930 | fatal("%s: sshkey_fingerprint fail", __func__); |
djm@openbsd.org | ac3451d | 2015-09-04 03:57:38 +0000 | [diff] [blame] | 931 | logit("Host key fingerprint is %s\n%s", fp, ra); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 932 | free(ra); |
| 933 | free(fp); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 934 | } |
djm@openbsd.org | 8d4f872 | 2015-01-26 03:04:45 +0000 | [diff] [blame] | 935 | hostkey_trusted = 1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 936 | break; |
| 937 | case HOST_NEW: |
Damien Miller | da82839 | 2006-08-05 11:35:45 +1000 | [diff] [blame] | 938 | if (options.host_key_alias == NULL && port != 0 && |
| 939 | port != SSH_DEFAULT_PORT) { |
| 940 | debug("checking without port identifier"); |
Damien Miller | ece92c8 | 2008-11-03 19:25:03 +1100 | [diff] [blame] | 941 | if (check_host_key(hostname, hostaddr, 0, host_key, |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 942 | ROQUIET, user_hostfiles, num_user_hostfiles, |
| 943 | system_hostfiles, num_system_hostfiles) == 0) { |
Damien Miller | da82839 | 2006-08-05 11:35:45 +1000 | [diff] [blame] | 944 | debug("found matching key w/out port"); |
| 945 | break; |
| 946 | } |
| 947 | } |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 948 | if (readonly || want_cert) |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 949 | goto fail; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 950 | /* The host is new. */ |
| 951 | if (options.strict_host_key_checking == 1) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 952 | /* |
| 953 | * User has requested strict host key checking. We |
| 954 | * will not add the host key automatically. The only |
| 955 | * alternative left is to abort. |
| 956 | */ |
| 957 | error("No %s host key is known for %.200s and you " |
| 958 | "have requested strict checking.", type, host); |
| 959 | goto fail; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 960 | } else if (options.strict_host_key_checking == 2) { |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 961 | char msg1[1024], msg2[1024]; |
| 962 | |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 963 | if (show_other_keys(host_hostkeys, host_key)) |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 964 | snprintf(msg1, sizeof(msg1), |
Damien Miller | 0dc1bef | 2005-07-17 17:22:45 +1000 | [diff] [blame] | 965 | "\nbut keys of different type are already" |
| 966 | " known for this host."); |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 967 | else |
| 968 | snprintf(msg1, sizeof(msg1), "."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 969 | /* The default */ |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 970 | fp = sshkey_fingerprint(host_key, |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 971 | options.fingerprint_hash, SSH_FP_DEFAULT); |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 972 | ra = sshkey_fingerprint(host_key, |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 973 | options.fingerprint_hash, SSH_FP_RANDOMART); |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 974 | if (fp == NULL || ra == NULL) |
| 975 | fatal("%s: sshkey_fingerprint fail", __func__); |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 976 | msg2[0] = '\0'; |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 977 | if (options.verify_host_key_dns) { |
Damien Miller | 150b557 | 2003-11-17 21:19:29 +1100 | [diff] [blame] | 978 | if (matching_host_key_dns) |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 979 | snprintf(msg2, sizeof(msg2), |
| 980 | "Matching host key fingerprint" |
| 981 | " found in DNS.\n"); |
| 982 | else |
| 983 | snprintf(msg2, sizeof(msg2), |
| 984 | "No matching host key fingerprint" |
| 985 | " found in DNS.\n"); |
| 986 | } |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 987 | snprintf(msg, sizeof(msg), |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 988 | "The authenticity of host '%.200s (%s)' can't be " |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 989 | "established%s\n" |
Damien Miller | 1028824 | 2008-06-30 00:04:03 +1000 | [diff] [blame] | 990 | "%s key fingerprint is %s.%s%s\n%s" |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 991 | "Are you sure you want to continue connecting " |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 992 | "(yes/no)? ", |
Damien Miller | 1028824 | 2008-06-30 00:04:03 +1000 | [diff] [blame] | 993 | host, ip, msg1, type, fp, |
| 994 | options.visual_host_key ? "\n" : "", |
| 995 | options.visual_host_key ? ra : "", |
| 996 | msg2); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 997 | free(ra); |
| 998 | free(fp); |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 999 | if (!confirm(msg)) |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1000 | goto fail; |
djm@openbsd.org | 8d4f872 | 2015-01-26 03:04:45 +0000 | [diff] [blame] | 1001 | hostkey_trusted = 1; /* user explicitly confirmed */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1002 | } |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1003 | /* |
| 1004 | * If not in strict mode, add the key automatically to the |
| 1005 | * local known_hosts file. |
| 1006 | */ |
Damien Miller | 1227d4c | 2005-03-02 12:06:51 +1100 | [diff] [blame] | 1007 | if (options.check_host_ip && ip_status == HOST_NEW) { |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1008 | snprintf(hostline, sizeof(hostline), "%s,%s", host, ip); |
Damien Miller | 1227d4c | 2005-03-02 12:06:51 +1100 | [diff] [blame] | 1009 | hostp = hostline; |
| 1010 | if (options.hash_known_hosts) { |
| 1011 | /* Add hash of host and IP separately */ |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 1012 | r = add_host_to_hostfile(user_hostfiles[0], |
| 1013 | host, host_key, options.hash_known_hosts) && |
| 1014 | add_host_to_hostfile(user_hostfiles[0], ip, |
Damien Miller | 1227d4c | 2005-03-02 12:06:51 +1100 | [diff] [blame] | 1015 | host_key, options.hash_known_hosts); |
| 1016 | } else { |
| 1017 | /* Add unhashed "host,ip" */ |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 1018 | r = add_host_to_hostfile(user_hostfiles[0], |
Damien Miller | 1227d4c | 2005-03-02 12:06:51 +1100 | [diff] [blame] | 1019 | hostline, host_key, |
| 1020 | options.hash_known_hosts); |
| 1021 | } |
| 1022 | } else { |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 1023 | r = add_host_to_hostfile(user_hostfiles[0], host, |
| 1024 | host_key, options.hash_known_hosts); |
Damien Miller | 1227d4c | 2005-03-02 12:06:51 +1100 | [diff] [blame] | 1025 | hostp = host; |
| 1026 | } |
| 1027 | |
| 1028 | if (!r) |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 1029 | logit("Failed to add the host to the list of known " |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 1030 | "hosts (%.500s).", user_hostfiles[0]); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1031 | else |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 1032 | logit("Warning: Permanently added '%.200s' (%s) to the " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1033 | "list of known hosts.", hostp, type); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1034 | break; |
Damien Miller | 1aed65e | 2010-03-04 21:53:35 +1100 | [diff] [blame] | 1035 | case HOST_REVOKED: |
| 1036 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 1037 | error("@ WARNING: REVOKED HOST KEY DETECTED! @"); |
| 1038 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 1039 | error("The %s host key for %s is marked as revoked.", type, host); |
| 1040 | error("This could mean that a stolen key is being used to"); |
| 1041 | error("impersonate this host."); |
| 1042 | |
| 1043 | /* |
| 1044 | * If strict host key checking is in use, the user will have |
| 1045 | * to edit the key manually and we can only abort. |
| 1046 | */ |
| 1047 | if (options.strict_host_key_checking) { |
| 1048 | error("%s host key for %.200s was revoked and you have " |
| 1049 | "requested strict checking.", type, host); |
| 1050 | goto fail; |
| 1051 | } |
| 1052 | goto continue_unsafe; |
| 1053 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1054 | case HOST_CHANGED: |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 1055 | if (want_cert) { |
| 1056 | /* |
| 1057 | * This is only a debug() since it is valid to have |
| 1058 | * CAs with wildcard DNS matches that don't match |
| 1059 | * all hosts that one might visit. |
| 1060 | */ |
| 1061 | debug("Host certificate authority does not " |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1062 | "match %s in %s:%lu", CA_MARKER, |
| 1063 | host_found->file, host_found->line); |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 1064 | goto fail; |
| 1065 | } |
Damien Miller | da82839 | 2006-08-05 11:35:45 +1000 | [diff] [blame] | 1066 | if (readonly == ROQUIET) |
| 1067 | goto fail; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1068 | if (options.check_host_ip && host_ip_differ) { |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 1069 | char *key_msg; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1070 | if (ip_status == HOST_NEW) |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 1071 | key_msg = "is unknown"; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1072 | else if (ip_status == HOST_OK) |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 1073 | key_msg = "is unchanged"; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1074 | else |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 1075 | key_msg = "has a different value"; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1076 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 1077 | error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @"); |
| 1078 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 1079 | error("The %s host key for %s has changed,", type, host); |
Darren Tucker | ff4454d | 2008-06-13 10:21:51 +1000 | [diff] [blame] | 1080 | error("and the key for the corresponding IP address %s", ip); |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 1081 | error("%s. This could either mean that", key_msg); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1082 | error("DNS SPOOFING is happening or the IP address for the host"); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1083 | error("and its host key have changed at the same time."); |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 1084 | if (ip_status != HOST_NEW) |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1085 | error("Offending key for IP in %s:%lu", |
| 1086 | ip_found->file, ip_found->line); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1087 | } |
| 1088 | /* The host key has changed. */ |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1089 | warn_changed_key(host_key); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1090 | 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] | 1091 | user_hostfiles[0]); |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1092 | error("Offending %s key in %s:%lu", key_type(host_found->key), |
| 1093 | host_found->file, host_found->line); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1094 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1095 | /* |
| 1096 | * If strict host key checking is in use, the user will have |
| 1097 | * to edit the key manually and we can only abort. |
| 1098 | */ |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1099 | if (options.strict_host_key_checking) { |
| 1100 | error("%s host key for %.200s has changed and you have " |
| 1101 | "requested strict checking.", type, host); |
| 1102 | goto fail; |
| 1103 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1104 | |
Damien Miller | 1aed65e | 2010-03-04 21:53:35 +1100 | [diff] [blame] | 1105 | continue_unsafe: |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1106 | /* |
| 1107 | * If strict host key checking has not been requested, allow |
Damien Miller | 941ac45 | 2003-06-04 20:31:53 +1000 | [diff] [blame] | 1108 | * the connection but without MITM-able authentication or |
Damien Miller | 437edb9 | 2006-08-05 09:11:13 +1000 | [diff] [blame] | 1109 | * forwarding. |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1110 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1111 | if (options.password_authentication) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1112 | error("Password authentication is disabled to avoid " |
| 1113 | "man-in-the-middle attacks."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1114 | options.password_authentication = 0; |
Darren Tucker | 068e01f | 2008-07-02 22:33:55 +1000 | [diff] [blame] | 1115 | cancelled_forwarding = 1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1116 | } |
Damien Miller | 941ac45 | 2003-06-04 20:31:53 +1000 | [diff] [blame] | 1117 | if (options.kbd_interactive_authentication) { |
| 1118 | error("Keyboard-interactive authentication is disabled" |
| 1119 | " to avoid man-in-the-middle attacks."); |
| 1120 | options.kbd_interactive_authentication = 0; |
| 1121 | options.challenge_response_authentication = 0; |
Darren Tucker | 068e01f | 2008-07-02 22:33:55 +1000 | [diff] [blame] | 1122 | cancelled_forwarding = 1; |
Damien Miller | 941ac45 | 2003-06-04 20:31:53 +1000 | [diff] [blame] | 1123 | } |
| 1124 | if (options.challenge_response_authentication) { |
| 1125 | error("Challenge/response authentication is disabled" |
| 1126 | " to avoid man-in-the-middle attacks."); |
| 1127 | options.challenge_response_authentication = 0; |
Darren Tucker | 068e01f | 2008-07-02 22:33:55 +1000 | [diff] [blame] | 1128 | cancelled_forwarding = 1; |
Damien Miller | 941ac45 | 2003-06-04 20:31:53 +1000 | [diff] [blame] | 1129 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1130 | if (options.forward_agent) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1131 | error("Agent forwarding is disabled to avoid " |
| 1132 | "man-in-the-middle attacks."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1133 | options.forward_agent = 0; |
Darren Tucker | 068e01f | 2008-07-02 22:33:55 +1000 | [diff] [blame] | 1134 | cancelled_forwarding = 1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1135 | } |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 1136 | if (options.forward_x11) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1137 | error("X11 forwarding is disabled to avoid " |
| 1138 | "man-in-the-middle attacks."); |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 1139 | options.forward_x11 = 0; |
Darren Tucker | 068e01f | 2008-07-02 22:33:55 +1000 | [diff] [blame] | 1140 | cancelled_forwarding = 1; |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 1141 | } |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1142 | if (options.num_local_forwards > 0 || |
| 1143 | options.num_remote_forwards > 0) { |
| 1144 | error("Port forwarding is disabled to avoid " |
| 1145 | "man-in-the-middle attacks."); |
| 1146 | options.num_local_forwards = |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 1147 | options.num_remote_forwards = 0; |
Darren Tucker | 068e01f | 2008-07-02 22:33:55 +1000 | [diff] [blame] | 1148 | cancelled_forwarding = 1; |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 1149 | } |
Damien Miller | 437edb9 | 2006-08-05 09:11:13 +1000 | [diff] [blame] | 1150 | if (options.tun_open != SSH_TUNMODE_NO) { |
| 1151 | error("Tunnel forwarding is disabled to avoid " |
| 1152 | "man-in-the-middle attacks."); |
| 1153 | options.tun_open = SSH_TUNMODE_NO; |
Darren Tucker | 068e01f | 2008-07-02 22:33:55 +1000 | [diff] [blame] | 1154 | cancelled_forwarding = 1; |
Damien Miller | 437edb9 | 2006-08-05 09:11:13 +1000 | [diff] [blame] | 1155 | } |
Darren Tucker | 068e01f | 2008-07-02 22:33:55 +1000 | [diff] [blame] | 1156 | if (options.exit_on_forward_failure && cancelled_forwarding) |
| 1157 | fatal("Error: forwarding disabled due to host key " |
| 1158 | "check failure"); |
| 1159 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1160 | /* |
| 1161 | * XXX Should permit the user to change to use the new id. |
| 1162 | * This could be done by converting the host key to an |
| 1163 | * identifying sentence, tell that the host identifies itself |
Darren Tucker | e2b3674 | 2010-01-13 22:42:34 +1100 | [diff] [blame] | 1164 | * by that sentence, and ask the user if he/she wishes to |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1165 | * accept the authentication. |
| 1166 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1167 | break; |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 1168 | case HOST_FOUND: |
| 1169 | fatal("internal error"); |
| 1170 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1171 | } |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 1172 | |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 1173 | if (options.check_host_ip && host_status != HOST_CHANGED && |
| 1174 | ip_status == HOST_CHANGED) { |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 1175 | snprintf(msg, sizeof(msg), |
| 1176 | "Warning: the %s host key for '%.200s' " |
| 1177 | "differs from the key for the IP address '%.128s'" |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1178 | "\nOffending key for IP in %s:%lu", |
| 1179 | type, host, ip, ip_found->file, ip_found->line); |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 1180 | if (host_status == HOST_OK) { |
| 1181 | len = strlen(msg); |
| 1182 | snprintf(msg + len, sizeof(msg) - len, |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1183 | "\nMatching host key in %s:%lu", |
| 1184 | host_found->file, host_found->line); |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 1185 | } |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 1186 | if (options.strict_host_key_checking == 1) { |
Damien Miller | ab2db41 | 2003-06-02 19:09:13 +1000 | [diff] [blame] | 1187 | logit("%s", msg); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1188 | error("Exiting, you have requested strict checking."); |
| 1189 | goto fail; |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 1190 | } else if (options.strict_host_key_checking == 2) { |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 1191 | strlcat(msg, "\nAre you sure you want " |
| 1192 | "to continue connecting (yes/no)? ", sizeof(msg)); |
| 1193 | if (!confirm(msg)) |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1194 | goto fail; |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 1195 | } else { |
Damien Miller | ab2db41 | 2003-06-02 19:09:13 +1000 | [diff] [blame] | 1196 | logit("%s", msg); |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 1197 | } |
| 1198 | } |
| 1199 | |
djm@openbsd.org | 8d4f872 | 2015-01-26 03:04:45 +0000 | [diff] [blame] | 1200 | if (!hostkey_trusted && options.update_hostkeys) { |
| 1201 | debug("%s: hostkey not known or explicitly trusted: " |
| 1202 | "disabling UpdateHostkeys", __func__); |
| 1203 | options.update_hostkeys = 0; |
| 1204 | } |
| 1205 | |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 1206 | free(ip); |
| 1207 | free(host); |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1208 | if (host_hostkeys != NULL) |
| 1209 | free_hostkeys(host_hostkeys); |
| 1210 | if (ip_hostkeys != NULL) |
| 1211 | free_hostkeys(ip_hostkeys); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1212 | return 0; |
| 1213 | |
| 1214 | fail: |
Damien Miller | 1aed65e | 2010-03-04 21:53:35 +1100 | [diff] [blame] | 1215 | if (want_cert && host_status != HOST_REVOKED) { |
Damien Miller | 0a80ca1 | 2010-02-27 07:55:05 +1100 | [diff] [blame] | 1216 | /* |
| 1217 | * No matching certificate. Downgrade cert to raw key and |
| 1218 | * search normally. |
| 1219 | */ |
| 1220 | debug("No matching CA found. Retry with plain key"); |
| 1221 | raw_key = key_from_private(host_key); |
| 1222 | if (key_drop_cert(raw_key) != 0) |
| 1223 | fatal("Couldn't drop certificate"); |
| 1224 | host_key = raw_key; |
| 1225 | goto retry; |
| 1226 | } |
| 1227 | if (raw_key != NULL) |
| 1228 | key_free(raw_key); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 1229 | free(ip); |
| 1230 | free(host); |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1231 | if (host_hostkeys != NULL) |
| 1232 | free_hostkeys(host_hostkeys); |
| 1233 | if (ip_hostkeys != NULL) |
| 1234 | free_hostkeys(ip_hostkeys); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1235 | return -1; |
| 1236 | } |
| 1237 | |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 1238 | /* returns 0 if key verifies or -1 if key does NOT verify */ |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1239 | int |
| 1240 | verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key) |
| 1241 | { |
djm@openbsd.org | f96516d | 2015-11-19 01:09:38 +0000 | [diff] [blame] | 1242 | u_int i; |
Damien Miller | 6b37fbb | 2014-07-04 08:59:24 +1000 | [diff] [blame] | 1243 | int r = -1, flags = 0; |
djm@openbsd.org | f96516d | 2015-11-19 01:09:38 +0000 | [diff] [blame] | 1244 | char valid[64], *fp = NULL, *cafp = NULL; |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 1245 | struct sshkey *plain = NULL; |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1246 | |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 1247 | if ((fp = sshkey_fingerprint(host_key, |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 1248 | options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) { |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 1249 | error("%s: fingerprint host key: %s", __func__, ssh_err(r)); |
| 1250 | r = -1; |
| 1251 | goto out; |
| 1252 | } |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 1253 | |
djm@openbsd.org | f96516d | 2015-11-19 01:09:38 +0000 | [diff] [blame] | 1254 | if (sshkey_is_cert(host_key)) { |
| 1255 | if ((cafp = sshkey_fingerprint(host_key->cert->signature_key, |
| 1256 | options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) { |
| 1257 | error("%s: fingerprint CA key: %s", |
| 1258 | __func__, ssh_err(r)); |
| 1259 | r = -1; |
| 1260 | goto out; |
| 1261 | } |
| 1262 | sshkey_format_cert_validity(host_key->cert, |
| 1263 | valid, sizeof(valid)); |
| 1264 | debug("Server host certificate: %s %s, serial %llu " |
| 1265 | "ID \"%s\" CA %s %s valid %s", |
| 1266 | sshkey_ssh_name(host_key), fp, |
djm@openbsd.org | 8ca915f | 2015-11-20 01:45:29 +0000 | [diff] [blame] | 1267 | (unsigned long long)host_key->cert->serial, |
| 1268 | host_key->cert->key_id, |
djm@openbsd.org | f96516d | 2015-11-19 01:09:38 +0000 | [diff] [blame] | 1269 | sshkey_ssh_name(host_key->cert->signature_key), cafp, |
| 1270 | valid); |
| 1271 | for (i = 0; i < host_key->cert->nprincipals; i++) { |
| 1272 | debug2("Server host certificate hostname: %s", |
| 1273 | host_key->cert->principals[i]); |
| 1274 | } |
| 1275 | } else { |
| 1276 | debug("Server host key: %s %s", compat20 ? |
| 1277 | sshkey_ssh_name(host_key) : sshkey_type(host_key), fp); |
| 1278 | } |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 1279 | |
| 1280 | if (sshkey_equal(previous_host_key, host_key)) { |
| 1281 | debug2("%s: server host key %s %s matches cached key", |
| 1282 | __func__, sshkey_type(host_key), fp); |
| 1283 | r = 0; |
| 1284 | goto out; |
| 1285 | } |
| 1286 | |
| 1287 | /* Check in RevokedHostKeys file if specified */ |
| 1288 | if (options.revoked_host_keys != NULL) { |
| 1289 | r = sshkey_check_revoked(host_key, options.revoked_host_keys); |
| 1290 | switch (r) { |
| 1291 | case 0: |
| 1292 | break; /* not revoked */ |
| 1293 | case SSH_ERR_KEY_REVOKED: |
| 1294 | error("Host key %s %s revoked by file %s", |
| 1295 | sshkey_type(host_key), fp, |
| 1296 | options.revoked_host_keys); |
| 1297 | r = -1; |
| 1298 | goto out; |
| 1299 | default: |
| 1300 | error("Error checking host key %s %s in " |
| 1301 | "revoked keys file %s: %s", sshkey_type(host_key), |
| 1302 | fp, options.revoked_host_keys, ssh_err(r)); |
| 1303 | r = -1; |
| 1304 | goto out; |
| 1305 | } |
Damien Miller | 6b37fbb | 2014-07-04 08:59:24 +1000 | [diff] [blame] | 1306 | } |
| 1307 | |
Damien Miller | 7d6a9fb | 2014-04-20 13:23:43 +1000 | [diff] [blame] | 1308 | if (options.verify_host_key_dns) { |
| 1309 | /* |
| 1310 | * XXX certs are not yet supported for DNS, so downgrade |
| 1311 | * them and try the plain key. |
| 1312 | */ |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 1313 | if ((r = sshkey_from_private(host_key, &plain)) != 0) |
| 1314 | goto out; |
| 1315 | if (sshkey_is_cert(plain)) |
| 1316 | sshkey_drop_cert(plain); |
Damien Miller | 7d6a9fb | 2014-04-20 13:23:43 +1000 | [diff] [blame] | 1317 | if (verify_host_key_dns(host, hostaddr, plain, &flags) == 0) { |
| 1318 | if (flags & DNS_VERIFY_FOUND) { |
| 1319 | if (options.verify_host_key_dns == 1 && |
| 1320 | flags & DNS_VERIFY_MATCH && |
| 1321 | flags & DNS_VERIFY_SECURE) { |
Damien Miller | 6b37fbb | 2014-07-04 08:59:24 +1000 | [diff] [blame] | 1322 | r = 0; |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 1323 | goto out; |
Damien Miller | 7d6a9fb | 2014-04-20 13:23:43 +1000 | [diff] [blame] | 1324 | } |
| 1325 | if (flags & DNS_VERIFY_MATCH) { |
| 1326 | matching_host_key_dns = 1; |
| 1327 | } else { |
| 1328 | warn_changed_key(plain); |
| 1329 | error("Update the SSHFP RR in DNS " |
| 1330 | "with the new host key to get rid " |
| 1331 | "of this message."); |
| 1332 | } |
Damien Miller | 150b557 | 2003-11-17 21:19:29 +1100 | [diff] [blame] | 1333 | } |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 1334 | } |
| 1335 | } |
Damien Miller | 6b37fbb | 2014-07-04 08:59:24 +1000 | [diff] [blame] | 1336 | r = check_host_key(host, hostaddr, options.port, host_key, RDRW, |
Damien Miller | 295ee63 | 2011-05-29 21:42:31 +1000 | [diff] [blame] | 1337 | options.user_hostfiles, options.num_user_hostfiles, |
| 1338 | options.system_hostfiles, options.num_system_hostfiles); |
Damien Miller | 6b37fbb | 2014-07-04 08:59:24 +1000 | [diff] [blame] | 1339 | |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 1340 | out: |
| 1341 | sshkey_free(plain); |
| 1342 | free(fp); |
djm@openbsd.org | f96516d | 2015-11-19 01:09:38 +0000 | [diff] [blame] | 1343 | free(cafp); |
Damien Miller | 6b37fbb | 2014-07-04 08:59:24 +1000 | [diff] [blame] | 1344 | if (r == 0 && host_key != NULL) { |
| 1345 | key_free(previous_host_key); |
| 1346 | previous_host_key = key_from_private(host_key); |
| 1347 | } |
| 1348 | |
| 1349 | return r; |
Damien Miller | a34a28b | 1999-12-14 10:47:15 +1100 | [diff] [blame] | 1350 | } |
Damien Miller | 037a0dc | 1999-12-07 15:38:31 +1100 | [diff] [blame] | 1351 | |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1352 | /* |
| 1353 | * Starts a dialog with the server, and authenticates the current user on the |
| 1354 | * server. This does not need any extra privileges. The basic connection |
| 1355 | * to the server must already have been established before this is called. |
| 1356 | * If login fails, this function prints an error and never returns. |
| 1357 | * This function does not require super-user privileges. |
| 1358 | */ |
| 1359 | void |
Ben Lindstrom | 1bad256 | 2002-06-06 19:57:33 +0000 | [diff] [blame] | 1360 | ssh_login(Sensitive *sensitive, const char *orighost, |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1361 | struct sockaddr *hostaddr, u_short port, struct passwd *pw, int timeout_ms) |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1362 | { |
Damien Miller | 0faf747 | 2013-10-17 11:47:23 +1100 | [diff] [blame] | 1363 | char *host; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1364 | char *server_user, *local_user; |
| 1365 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1366 | local_user = xstrdup(pw->pw_name); |
| 1367 | server_user = options.user ? options.user : local_user; |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1368 | |
| 1369 | /* Convert the user-supplied hostname into all lowercase. */ |
| 1370 | host = xstrdup(orighost); |
Damien Miller | 0faf747 | 2013-10-17 11:47:23 +1100 | [diff] [blame] | 1371 | lowercase(host); |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1372 | |
| 1373 | /* Exchange protocol version identification strings with the server. */ |
Damien Miller | 67bd062 | 2007-09-17 12:06:57 +1000 | [diff] [blame] | 1374 | ssh_exchange_identification(timeout_ms); |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1375 | |
| 1376 | /* Put the connection into non-blocking mode. */ |
| 1377 | packet_set_nonblocking(); |
| 1378 | |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1379 | /* key exchange */ |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1380 | /* authenticate user */ |
dtucker@openbsd.org | bb2289e | 2015-04-14 04:17:03 +0000 | [diff] [blame] | 1381 | debug("Authenticating to %s:%d as '%s'", host, port, server_user); |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 1382 | if (compat20) { |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1383 | ssh_kex2(host, hostaddr, port); |
Ben Lindstrom | 1bad256 | 2002-06-06 19:57:33 +0000 | [diff] [blame] | 1384 | ssh_userauth2(local_user, server_user, host, sensitive); |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 1385 | } else { |
Damien Miller | 1f0311c | 2014-05-15 14:24:09 +1000 | [diff] [blame] | 1386 | #ifdef WITH_SSH1 |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 1387 | ssh_kex(host, hostaddr); |
Ben Lindstrom | 1bad256 | 2002-06-06 19:57:33 +0000 | [diff] [blame] | 1388 | ssh_userauth1(local_user, server_user, host, sensitive); |
Damien Miller | 1f0311c | 2014-05-15 14:24:09 +1000 | [diff] [blame] | 1389 | #else |
djm@openbsd.org | 53097b2 | 2015-03-24 01:11:12 +0000 | [diff] [blame] | 1390 | fatal("ssh1 is not supported"); |
Damien Miller | 1f0311c | 2014-05-15 14:24:09 +1000 | [diff] [blame] | 1391 | #endif |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 1392 | } |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 1393 | free(local_user); |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1394 | } |
Damien Miller | 79438cc | 2001-02-16 12:34:57 +1100 | [diff] [blame] | 1395 | |
| 1396 | void |
| 1397 | ssh_put_password(char *password) |
| 1398 | { |
| 1399 | int size; |
| 1400 | char *padded; |
| 1401 | |
Ben Lindstrom | d20d0f3 | 2001-03-10 17:22:20 +0000 | [diff] [blame] | 1402 | if (datafellows & SSH_BUG_PASSWORDPAD) { |
Ben Lindstrom | 664408d | 2001-06-09 01:42:01 +0000 | [diff] [blame] | 1403 | packet_put_cstring(password); |
Ben Lindstrom | d20d0f3 | 2001-03-10 17:22:20 +0000 | [diff] [blame] | 1404 | return; |
| 1405 | } |
Damien Miller | 79438cc | 2001-02-16 12:34:57 +1100 | [diff] [blame] | 1406 | size = roundup(strlen(password) + 1, 32); |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 1407 | padded = xcalloc(1, size); |
Damien Miller | 79438cc | 2001-02-16 12:34:57 +1100 | [diff] [blame] | 1408 | strlcpy(padded, password, size); |
| 1409 | packet_put_string(padded, size); |
Damien Miller | a5103f4 | 2014-02-04 11:20:14 +1100 | [diff] [blame] | 1410 | explicit_bzero(padded, size); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 1411 | free(padded); |
Damien Miller | 79438cc | 2001-02-16 12:34:57 +1100 | [diff] [blame] | 1412 | } |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 1413 | |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 1414 | /* print all known host keys for a given host, but skip keys of given type */ |
| 1415 | static int |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1416 | show_other_keys(struct hostkeys *hostkeys, Key *key) |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 1417 | { |
Damien Miller | 106bf1c | 2013-12-29 17:54:03 +1100 | [diff] [blame] | 1418 | int type[] = { |
| 1419 | KEY_RSA1, |
| 1420 | KEY_RSA, |
| 1421 | KEY_DSA, |
| 1422 | KEY_ECDSA, |
| 1423 | KEY_ED25519, |
| 1424 | -1 |
| 1425 | }; |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1426 | int i, ret = 0; |
| 1427 | char *fp, *ra; |
| 1428 | const struct hostkey_entry *found; |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 1429 | |
| 1430 | for (i = 0; type[i] != -1; i++) { |
| 1431 | if (type[i] == key->type) |
| 1432 | continue; |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1433 | if (!lookup_key_in_hostkeys_by_type(hostkeys, type[i], &found)) |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 1434 | continue; |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 1435 | fp = sshkey_fingerprint(found->key, |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 1436 | options.fingerprint_hash, SSH_FP_DEFAULT); |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 1437 | ra = sshkey_fingerprint(found->key, |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 1438 | options.fingerprint_hash, SSH_FP_RANDOMART); |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 1439 | if (fp == NULL || ra == NULL) |
| 1440 | fatal("%s: sshkey_fingerprint fail", __func__); |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1441 | logit("WARNING: %s key found for host %s\n" |
| 1442 | "in %s:%lu\n" |
| 1443 | "%s key fingerprint %s.", |
| 1444 | key_type(found->key), |
| 1445 | found->host, found->file, found->line, |
| 1446 | key_type(found->key), fp); |
| 1447 | if (options.visual_host_key) |
| 1448 | logit("%s", ra); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 1449 | free(ra); |
| 1450 | free(fp); |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1451 | ret = 1; |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 1452 | } |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 1453 | return ret; |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 1454 | } |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1455 | |
| 1456 | static void |
| 1457 | warn_changed_key(Key *host_key) |
| 1458 | { |
| 1459 | char *fp; |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1460 | |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 1461 | fp = sshkey_fingerprint(host_key, options.fingerprint_hash, |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 1462 | SSH_FP_DEFAULT); |
djm@openbsd.org | 9ce86c9 | 2015-01-28 22:36:00 +0000 | [diff] [blame] | 1463 | if (fp == NULL) |
| 1464 | fatal("%s: sshkey_fingerprint fail", __func__); |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1465 | |
| 1466 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 1467 | error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @"); |
| 1468 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 1469 | error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!"); |
| 1470 | 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] | 1471 | 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] | 1472 | 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] | 1473 | key_type(host_key), fp); |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1474 | error("Please contact your system administrator."); |
| 1475 | |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 1476 | free(fp); |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1477 | } |
Damien Miller | d27b947 | 2005-12-13 19:29:02 +1100 | [diff] [blame] | 1478 | |
| 1479 | /* |
| 1480 | * Execute a local command |
| 1481 | */ |
| 1482 | int |
| 1483 | ssh_local_cmd(const char *args) |
| 1484 | { |
| 1485 | char *shell; |
| 1486 | pid_t pid; |
| 1487 | int status; |
Damien Miller | ed3a8eb | 2011-01-07 10:02:52 +1100 | [diff] [blame] | 1488 | void (*osighand)(int); |
Damien Miller | d27b947 | 2005-12-13 19:29:02 +1100 | [diff] [blame] | 1489 | |
| 1490 | if (!options.permit_local_command || |
| 1491 | args == NULL || !*args) |
| 1492 | return (1); |
| 1493 | |
Damien Miller | 38d9a96 | 2010-10-07 22:07:11 +1100 | [diff] [blame] | 1494 | if ((shell = getenv("SHELL")) == NULL || *shell == '\0') |
Damien Miller | d27b947 | 2005-12-13 19:29:02 +1100 | [diff] [blame] | 1495 | shell = _PATH_BSHELL; |
| 1496 | |
Damien Miller | ed3a8eb | 2011-01-07 10:02:52 +1100 | [diff] [blame] | 1497 | osighand = signal(SIGCHLD, SIG_DFL); |
Damien Miller | d27b947 | 2005-12-13 19:29:02 +1100 | [diff] [blame] | 1498 | pid = fork(); |
| 1499 | if (pid == 0) { |
Damien Miller | 6fb6fd5 | 2011-01-16 23:17:45 +1100 | [diff] [blame] | 1500 | signal(SIGPIPE, SIG_DFL); |
Damien Miller | d27b947 | 2005-12-13 19:29:02 +1100 | [diff] [blame] | 1501 | debug3("Executing %s -c \"%s\"", shell, args); |
| 1502 | execl(shell, shell, "-c", args, (char *)NULL); |
| 1503 | error("Couldn't execute %s -c \"%s\": %s", |
| 1504 | shell, args, strerror(errno)); |
| 1505 | _exit(1); |
| 1506 | } else if (pid == -1) |
| 1507 | fatal("fork failed: %.100s", strerror(errno)); |
| 1508 | while (waitpid(pid, &status, 0) == -1) |
| 1509 | if (errno != EINTR) |
| 1510 | fatal("Couldn't wait for child: %s", strerror(errno)); |
Damien Miller | ed3a8eb | 2011-01-07 10:02:52 +1100 | [diff] [blame] | 1511 | signal(SIGCHLD, osighand); |
Damien Miller | d27b947 | 2005-12-13 19:29:02 +1100 | [diff] [blame] | 1512 | |
| 1513 | if (!WIFEXITED(status)) |
| 1514 | return (1); |
| 1515 | |
| 1516 | return (WEXITSTATUS(status)); |
| 1517 | } |
jcs@openbsd.org | f361df4 | 2015-11-15 22:26:49 +0000 | [diff] [blame] | 1518 | |
| 1519 | void |
| 1520 | maybe_add_key_to_agent(char *authfile, Key *private, char *comment, |
| 1521 | char *passphrase) |
| 1522 | { |
| 1523 | int auth_sock = -1, r; |
| 1524 | |
| 1525 | if (options.add_keys_to_agent == 0) |
| 1526 | return; |
| 1527 | |
| 1528 | if ((r = ssh_get_authentication_socket(&auth_sock)) != 0) { |
| 1529 | debug3("no authentication agent, not adding key"); |
| 1530 | return; |
| 1531 | } |
| 1532 | |
| 1533 | if (options.add_keys_to_agent == 2 && |
| 1534 | !ask_permission("Add key %s (%s) to agent?", authfile, comment)) { |
| 1535 | debug3("user denied adding this key"); |
| 1536 | return; |
| 1537 | } |
| 1538 | |
| 1539 | if ((r = ssh_add_identity_constrained(auth_sock, private, comment, 0, |
| 1540 | (options.add_keys_to_agent == 3))) == 0) |
| 1541 | debug("identity added to agent: %s", authfile); |
| 1542 | else |
| 1543 | debug("could not add identity to agent: %s (%d)", authfile, r); |
| 1544 | } |