Damien Miller | b757677 | 2006-07-10 20:23:39 +1000 | [diff] [blame^] | 1 | /* $OpenBSD: sshconnect.c,v 1.186 2006/07/03 08:54:20 stevesk Exp $ */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 3 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
| 4 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 5 | * All rights reserved |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 6 | * Code to connect to a remote host, and to perform the client side of the |
| 7 | * login (authentication) dialog. |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 8 | * |
| 9 | * As far as I am concerned, the code I have written for this software |
| 10 | * can be used freely for any purpose. Any derived versions of this |
| 11 | * software must be clearly marked as such, and if the derived work is |
| 12 | * incompatible with the protocol description in the RFC file, it must be |
| 13 | * called by a name other than "ssh" or "Secure Shell". |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 14 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 15 | |
| 16 | #include "includes.h" |
Damien Miller | 9cf6d07 | 2006-03-15 11:29:24 +1100 | [diff] [blame] | 17 | |
| 18 | #include <sys/types.h> |
| 19 | #include <sys/wait.h> |
Damien Miller | f17883e | 2006-03-15 11:45:54 +1100 | [diff] [blame] | 20 | #include <sys/stat.h> |
Damien Miller | 03e2003 | 2006-03-15 11:16:59 +1100 | [diff] [blame] | 21 | |
Damien Miller | c7b0636 | 2006-03-15 11:53:45 +1100 | [diff] [blame] | 22 | #include <ctype.h> |
Damien Miller | 6645e7a | 2006-03-15 14:42:54 +1100 | [diff] [blame] | 23 | #ifdef HAVE_PATHS_H |
Damien Miller | 03e2003 | 2006-03-15 11:16:59 +1100 | [diff] [blame] | 24 | #include <paths.h> |
Damien Miller | 6645e7a | 2006-03-15 14:42:54 +1100 | [diff] [blame] | 25 | #endif |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 26 | |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 27 | #include "ssh.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 28 | #include "xmalloc.h" |
| 29 | #include "rsa.h" |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 30 | #include "buffer.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 31 | #include "packet.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 32 | #include "uidswap.h" |
| 33 | #include "compat.h" |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 34 | #include "key.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 35 | #include "sshconnect.h" |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 36 | #include "hostfile.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 37 | #include "log.h" |
| 38 | #include "readconf.h" |
| 39 | #include "atomicio.h" |
| 40 | #include "misc.h" |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 41 | #include "dns.h" |
Damien Miller | b757677 | 2006-07-10 20:23:39 +1000 | [diff] [blame^] | 42 | #include "version.h" |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 43 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 44 | char *client_version_string = NULL; |
| 45 | char *server_version_string = NULL; |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 46 | |
Damien Miller | c1af1d5 | 2005-11-05 15:08:57 +1100 | [diff] [blame] | 47 | static int matching_host_key_dns = 0; |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 48 | |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 49 | /* import */ |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 50 | extern Options options; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 51 | extern char *__progname; |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 52 | extern uid_t original_real_uid; |
| 53 | extern uid_t original_effective_uid; |
Damien Miller | 8c4e18a | 2002-09-19 12:05:02 +1000 | [diff] [blame] | 54 | extern pid_t proxy_command_pid; |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 55 | |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 56 | #ifndef INET6_ADDRSTRLEN /* for non IPv6 machines */ |
| 57 | #define INET6_ADDRSTRLEN 46 |
| 58 | #endif |
| 59 | |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 60 | static int show_other_keys(const char *, Key *); |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 61 | static void warn_changed_key(Key *); |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 62 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 63 | /* |
| 64 | * Connect to the given ssh server using a proxy command. |
| 65 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 66 | static int |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 67 | 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] | 68 | { |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 69 | char *command_string, *tmp; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 70 | int pin[2], pout[2]; |
Damien Miller | 166fca8 | 2000-04-20 07:42:21 +1000 | [diff] [blame] | 71 | pid_t pid; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 72 | char strport[NI_MAXSERV]; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 73 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 74 | /* Convert the port number into a string. */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 75 | snprintf(strport, sizeof strport, "%hu", port); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 76 | |
Damien Miller | 8c4e18a | 2002-09-19 12:05:02 +1000 | [diff] [blame] | 77 | /* |
| 78 | * Build the final command string in the buffer by making the |
| 79 | * appropriate substitutions to the given proxy command. |
| 80 | * |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 81 | * Use "exec" to avoid "sh -c" processes on some platforms |
Damien Miller | 8c4e18a | 2002-09-19 12:05:02 +1000 | [diff] [blame] | 82 | * (e.g. Solaris) |
| 83 | */ |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 84 | xasprintf(&tmp, "exec %s", proxy_command); |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 85 | command_string = percent_expand(tmp, "h", host, |
| 86 | "p", strport, (char *)NULL); |
| 87 | xfree(tmp); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 88 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 89 | /* Create pipes for communicating with the proxy. */ |
| 90 | if (pipe(pin) < 0 || pipe(pout) < 0) |
| 91 | fatal("Could not create pipes to communicate with the proxy: %.100s", |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 92 | strerror(errno)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 93 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 94 | debug("Executing proxy command: %.500s", command_string); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 95 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 96 | /* Fork and execute the proxy command. */ |
| 97 | if ((pid = fork()) == 0) { |
| 98 | char *argv[10]; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 99 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 100 | /* Child. Permanently give up superuser privileges. */ |
Damien Miller | 2e5fe88 | 2006-06-13 13:10:00 +1000 | [diff] [blame] | 101 | permanently_drop_suid(original_real_uid); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 102 | |
| 103 | /* Redirect stdin and stdout. */ |
| 104 | close(pin[1]); |
| 105 | if (pin[0] != 0) { |
| 106 | if (dup2(pin[0], 0) < 0) |
| 107 | perror("dup2 stdin"); |
| 108 | close(pin[0]); |
| 109 | } |
| 110 | close(pout[0]); |
| 111 | if (dup2(pout[1], 1) < 0) |
| 112 | perror("dup2 stdout"); |
| 113 | /* Cannot be 1 because pin allocated two descriptors. */ |
| 114 | close(pout[1]); |
| 115 | |
| 116 | /* Stderr is left as it is so that error messages get |
| 117 | printed on the user's terminal. */ |
Damien Miller | 7b413d2 | 2000-07-01 13:24:21 +1000 | [diff] [blame] | 118 | argv[0] = _PATH_BSHELL; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 119 | argv[1] = "-c"; |
| 120 | argv[2] = command_string; |
| 121 | argv[3] = NULL; |
| 122 | |
| 123 | /* Execute the proxy command. Note that we gave up any |
| 124 | extra privileges above. */ |
Kevin Steves | fcd5d60 | 2001-01-07 11:45:22 +0000 | [diff] [blame] | 125 | execv(argv[0], argv); |
| 126 | perror(argv[0]); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 127 | exit(1); |
| 128 | } |
| 129 | /* Parent. */ |
| 130 | if (pid < 0) |
| 131 | fatal("fork failed: %.100s", strerror(errno)); |
Damien Miller | 8c4e18a | 2002-09-19 12:05:02 +1000 | [diff] [blame] | 132 | else |
| 133 | proxy_command_pid = pid; /* save pid to clean up later */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 134 | |
| 135 | /* Close child side of the descriptors. */ |
| 136 | close(pin[0]); |
| 137 | close(pout[1]); |
| 138 | |
| 139 | /* Free the command name. */ |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 140 | xfree(command_string); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 141 | |
| 142 | /* Set the connection file descriptors. */ |
| 143 | packet_set_connection(pout[0], pin[1]); |
| 144 | |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 145 | /* Indicate OK return */ |
| 146 | return 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 147 | } |
| 148 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 149 | /* |
| 150 | * Creates a (possibly privileged) socket for use as the ssh connection. |
| 151 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 152 | static int |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 153 | ssh_create_socket(int privileged, struct addrinfo *ai) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 154 | { |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 155 | int sock, gaierr; |
| 156 | struct addrinfo hints, *res; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 157 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 158 | /* |
| 159 | * If we are running as root and want to connect to a privileged |
| 160 | * port, bind our own socket to a privileged port. |
| 161 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 162 | if (privileged) { |
| 163 | int p = IPPORT_RESERVED - 1; |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 164 | PRIV_START; |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 165 | sock = rresvport_af(&p, ai->ai_family); |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 166 | PRIV_END; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 167 | if (sock < 0) |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 168 | error("rresvport: af=%d %.100s", ai->ai_family, |
| 169 | strerror(errno)); |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 170 | else |
| 171 | debug("Allocated local port %d.", p); |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 172 | return sock; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 173 | } |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 174 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 175 | if (sock < 0) |
| 176 | error("socket: %.100s", strerror(errno)); |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 177 | |
| 178 | /* Bind the socket to an alternative local IP address */ |
| 179 | if (options.bind_address == NULL) |
| 180 | return sock; |
| 181 | |
| 182 | memset(&hints, 0, sizeof(hints)); |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 183 | hints.ai_family = ai->ai_family; |
| 184 | hints.ai_socktype = ai->ai_socktype; |
| 185 | hints.ai_protocol = ai->ai_protocol; |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 186 | hints.ai_flags = AI_PASSIVE; |
| 187 | gaierr = getaddrinfo(options.bind_address, "0", &hints, &res); |
| 188 | if (gaierr) { |
| 189 | error("getaddrinfo: %s: %s", options.bind_address, |
| 190 | gai_strerror(gaierr)); |
| 191 | close(sock); |
| 192 | return -1; |
| 193 | } |
| 194 | if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) { |
| 195 | error("bind: %s: %s", options.bind_address, strerror(errno)); |
| 196 | close(sock); |
| 197 | freeaddrinfo(res); |
| 198 | return -1; |
| 199 | } |
| 200 | freeaddrinfo(res); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 201 | return sock; |
| 202 | } |
| 203 | |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 204 | static int |
| 205 | timeout_connect(int sockfd, const struct sockaddr *serv_addr, |
| 206 | socklen_t addrlen, int timeout) |
| 207 | { |
| 208 | fd_set *fdset; |
| 209 | struct timeval tv; |
| 210 | socklen_t optlen; |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 211 | int optval, rc, result = -1; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 212 | |
| 213 | if (timeout <= 0) |
| 214 | return (connect(sockfd, serv_addr, addrlen)); |
| 215 | |
Damien Miller | f6723f0 | 2004-01-27 21:21:27 +1100 | [diff] [blame] | 216 | set_nonblock(sockfd); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 217 | rc = connect(sockfd, serv_addr, addrlen); |
Damien Miller | f6723f0 | 2004-01-27 21:21:27 +1100 | [diff] [blame] | 218 | if (rc == 0) { |
| 219 | unset_nonblock(sockfd); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 220 | return (0); |
Damien Miller | f6723f0 | 2004-01-27 21:21:27 +1100 | [diff] [blame] | 221 | } |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 222 | if (errno != EINPROGRESS) |
| 223 | return (-1); |
| 224 | |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 225 | fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS), |
| 226 | sizeof(fd_mask)); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 227 | FD_SET(sockfd, fdset); |
| 228 | tv.tv_sec = timeout; |
| 229 | tv.tv_usec = 0; |
| 230 | |
Darren Tucker | 47eede7 | 2005-03-14 23:08:12 +1100 | [diff] [blame] | 231 | for (;;) { |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 232 | rc = select(sockfd + 1, NULL, fdset, NULL, &tv); |
| 233 | if (rc != -1 || errno != EINTR) |
| 234 | break; |
| 235 | } |
| 236 | |
Darren Tucker | 47eede7 | 2005-03-14 23:08:12 +1100 | [diff] [blame] | 237 | switch (rc) { |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 238 | case 0: |
| 239 | /* Timed out */ |
| 240 | errno = ETIMEDOUT; |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 241 | break; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 242 | case -1: |
| 243 | /* Select error */ |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 244 | debug("select: %s", strerror(errno)); |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 245 | break; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 246 | case 1: |
| 247 | /* Completed or failed */ |
| 248 | optval = 0; |
| 249 | optlen = sizeof(optval); |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 250 | if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, |
Darren Tucker | bd5361b | 2003-09-22 20:59:16 +1000 | [diff] [blame] | 251 | &optlen) == -1) { |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 252 | debug("getsockopt: %s", strerror(errno)); |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 253 | break; |
Darren Tucker | bd5361b | 2003-09-22 20:59:16 +1000 | [diff] [blame] | 254 | } |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 255 | if (optval != 0) { |
| 256 | errno = optval; |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 257 | break; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 258 | } |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 259 | result = 0; |
Damien Miller | f6723f0 | 2004-01-27 21:21:27 +1100 | [diff] [blame] | 260 | unset_nonblock(sockfd); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 261 | break; |
| 262 | default: |
| 263 | /* Should not occur */ |
| 264 | fatal("Bogus return (%d) from select()", rc); |
| 265 | } |
| 266 | |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 267 | xfree(fdset); |
| 268 | return (result); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 269 | } |
| 270 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 271 | /* |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 272 | * Opens a TCP/IP connection to the remote server on the given host. |
| 273 | * The address of the remote host will be returned in hostaddr. |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 274 | * 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] | 275 | * a privileged port will be allocated to make the connection. |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 276 | * This requires super-user privileges if needpriv is true. |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 277 | * Connection_attempts specifies the maximum number of tries (one per |
| 278 | * second). If proxy_command is non-NULL, it specifies the command (with %h |
| 279 | * and %p substituted for host and port, respectively) to use to contact |
| 280 | * the daemon. |
| 281 | */ |
| 282 | int |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 283 | ssh_connect(const char *host, struct sockaddr_storage * hostaddr, |
Damien Miller | 139d4cd | 2001-10-10 15:07:44 +1000 | [diff] [blame] | 284 | u_short port, int family, int connection_attempts, |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 285 | int needpriv, const char *proxy_command) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 286 | { |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 287 | int gaierr; |
Ben Lindstrom | bf555ba | 2001-01-18 02:04:35 +0000 | [diff] [blame] | 288 | int on = 1; |
| 289 | int sock = -1, attempt; |
| 290 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
| 291 | struct addrinfo hints, *ai, *aitop; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 292 | |
Ben Lindstrom | 064496f | 2002-12-23 02:04:22 +0000 | [diff] [blame] | 293 | debug2("ssh_connect: needpriv %d", needpriv); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 294 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 295 | /* If a proxy command is given, connect using it. */ |
| 296 | if (proxy_command != NULL) |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 297 | return ssh_proxy_connect(host, port, proxy_command); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 298 | |
| 299 | /* No proxy command. */ |
| 300 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 301 | memset(&hints, 0, sizeof(hints)); |
Damien Miller | 139d4cd | 2001-10-10 15:07:44 +1000 | [diff] [blame] | 302 | hints.ai_family = family; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 303 | hints.ai_socktype = SOCK_STREAM; |
Ben Lindstrom | 5c38552 | 2002-06-23 21:23:20 +0000 | [diff] [blame] | 304 | snprintf(strport, sizeof strport, "%u", port); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 305 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) |
| 306 | fatal("%s: %.100s: %s", __progname, host, |
| 307 | gai_strerror(gaierr)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 308 | |
Damien Miller | 56e5e6a | 2006-04-23 12:08:59 +1000 | [diff] [blame] | 309 | for (attempt = 0; attempt < connection_attempts; attempt++) { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 310 | if (attempt > 0) |
| 311 | debug("Trying again..."); |
| 312 | |
Damien Miller | 56e5e6a | 2006-04-23 12:08:59 +1000 | [diff] [blame] | 313 | /* |
| 314 | * Loop through addresses for this host, and try each one in |
| 315 | * sequence until the connection succeeds. |
| 316 | */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 317 | for (ai = aitop; ai; ai = ai->ai_next) { |
| 318 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) |
| 319 | continue; |
| 320 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, |
| 321 | ntop, sizeof(ntop), strport, sizeof(strport), |
| 322 | NI_NUMERICHOST|NI_NUMERICSERV) != 0) { |
| 323 | error("ssh_connect: getnameinfo failed"); |
| 324 | continue; |
| 325 | } |
| 326 | debug("Connecting to %.200s [%.100s] port %s.", |
| 327 | host, ntop, strport); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 328 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 329 | /* Create a socket for connecting. */ |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 330 | sock = ssh_create_socket(needpriv, ai); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 331 | if (sock < 0) |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 332 | /* Any error is already output */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 333 | continue; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 334 | |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 335 | if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen, |
| 336 | options.connection_timeout) >= 0) { |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 337 | /* Successful connection. */ |
Ben Lindstrom | a370005 | 2001-04-05 23:26:32 +0000 | [diff] [blame] | 338 | memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 339 | break; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 340 | } else { |
Ben Lindstrom | 728aa7e | 2002-07-15 17:48:11 +0000 | [diff] [blame] | 341 | debug("connect to address %s port %s: %s", |
| 342 | ntop, strport, strerror(errno)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 343 | close(sock); |
Damien Miller | 56e5e6a | 2006-04-23 12:08:59 +1000 | [diff] [blame] | 344 | sock = -1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 345 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 346 | } |
Damien Miller | 56e5e6a | 2006-04-23 12:08:59 +1000 | [diff] [blame] | 347 | if (sock != -1) |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 348 | break; /* Successful connection. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 349 | |
| 350 | /* Sleep a moment before retrying. */ |
| 351 | sleep(1); |
| 352 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 353 | |
| 354 | freeaddrinfo(aitop); |
| 355 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 356 | /* Return failure if we didn't get a successful connection. */ |
Damien Miller | 56e5e6a | 2006-04-23 12:08:59 +1000 | [diff] [blame] | 357 | if (sock == -1) { |
Darren Tucker | b2161e3 | 2005-01-20 11:00:46 +1100 | [diff] [blame] | 358 | error("ssh: connect to host %s port %s: %s", |
Ben Lindstrom | a6cd75c | 2002-07-11 04:00:19 +0000 | [diff] [blame] | 359 | host, strport, strerror(errno)); |
Darren Tucker | b2161e3 | 2005-01-20 11:00:46 +1100 | [diff] [blame] | 360 | return (-1); |
Ben Lindstrom | a6cd75c | 2002-07-11 04:00:19 +0000 | [diff] [blame] | 361 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 362 | |
| 363 | debug("Connection established."); |
| 364 | |
Damien Miller | 12c150e | 2003-12-17 16:31:10 +1100 | [diff] [blame] | 365 | /* Set SO_KEEPALIVE if requested. */ |
| 366 | if (options.tcp_keep_alive && |
Ben Lindstrom | bf555ba | 2001-01-18 02:04:35 +0000 | [diff] [blame] | 367 | setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, |
| 368 | sizeof(on)) < 0) |
| 369 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 370 | |
| 371 | /* Set the connection. */ |
| 372 | packet_set_connection(sock, sock); |
| 373 | |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 374 | return 0; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 375 | } |
| 376 | |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 377 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 378 | * Waits for the server identification string, and sends our own |
| 379 | * identification string. |
| 380 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 381 | static void |
Ben Lindstrom | 31ca54a | 2001-02-09 02:11:24 +0000 | [diff] [blame] | 382 | ssh_exchange_identification(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 383 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 384 | char buf[256], remote_version[256]; /* must be same size! */ |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 385 | int remote_major, remote_minor, mismatch; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 386 | int connection_in = packet_get_connection_in(); |
| 387 | int connection_out = packet_get_connection_out(); |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 388 | int minor1 = PROTOCOL_MINOR_1; |
Damien Miller | 1e88ea6 | 2006-07-10 20:15:56 +1000 | [diff] [blame] | 389 | u_int i, n; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 390 | |
Damien Miller | b253cc4 | 2005-05-26 12:23:44 +1000 | [diff] [blame] | 391 | /* Read other side's version identification. */ |
Damien Miller | 1e88ea6 | 2006-07-10 20:15:56 +1000 | [diff] [blame] | 392 | for (n = 0;;) { |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 393 | for (i = 0; i < sizeof(buf) - 1; i++) { |
Damien Miller | b253cc4 | 2005-05-26 12:23:44 +1000 | [diff] [blame] | 394 | size_t len = atomicio(read, connection_in, &buf[i], 1); |
| 395 | |
Damien Miller | 46d38de | 2005-07-17 17:02:09 +1000 | [diff] [blame] | 396 | if (len != 1 && errno == EPIPE) |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 397 | fatal("ssh_exchange_identification: Connection closed by remote host"); |
Damien Miller | b253cc4 | 2005-05-26 12:23:44 +1000 | [diff] [blame] | 398 | else if (len != 1) |
| 399 | fatal("ssh_exchange_identification: read: %.100s", strerror(errno)); |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 400 | if (buf[i] == '\r') { |
| 401 | buf[i] = '\n'; |
| 402 | buf[i + 1] = 0; |
| 403 | continue; /**XXX wait for \n */ |
| 404 | } |
| 405 | if (buf[i] == '\n') { |
| 406 | buf[i + 1] = 0; |
| 407 | break; |
| 408 | } |
Damien Miller | 1e88ea6 | 2006-07-10 20:15:56 +1000 | [diff] [blame] | 409 | if (++n > 65536) |
| 410 | fatal("ssh_exchange_identification: No banner received"); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 411 | } |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 412 | buf[sizeof(buf) - 1] = 0; |
| 413 | if (strncmp(buf, "SSH-", 4) == 0) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 414 | break; |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 415 | debug("ssh_exchange_identification: %s", buf); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 416 | } |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 417 | server_version_string = xstrdup(buf); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 418 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 419 | /* |
| 420 | * Check that the versions match. In future this might accept |
| 421 | * several versions and set appropriate flags to handle them. |
| 422 | */ |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 423 | if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n", |
| 424 | &remote_major, &remote_minor, remote_version) != 3) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 425 | fatal("Bad remote protocol version identification: '%.100s'", buf); |
| 426 | debug("Remote protocol version %d.%d, remote software version %.100s", |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 427 | remote_major, remote_minor, remote_version); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 428 | |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 429 | compat_datafellows(remote_version); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 430 | mismatch = 0; |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 431 | |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 432 | switch (remote_major) { |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 433 | case 1: |
| 434 | if (remote_minor == 99 && |
| 435 | (options.protocol & SSH_PROTO_2) && |
| 436 | !(options.protocol & SSH_PROTO_1_PREFERRED)) { |
| 437 | enable_compat20(); |
| 438 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 439 | } |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 440 | if (!(options.protocol & SSH_PROTO_1)) { |
| 441 | mismatch = 1; |
| 442 | break; |
| 443 | } |
| 444 | if (remote_minor < 3) { |
| 445 | fatal("Remote machine has too old SSH software version."); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 446 | } else if (remote_minor == 3 || remote_minor == 4) { |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 447 | /* We speak 1.3, too. */ |
| 448 | enable_compat13(); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 449 | minor1 = 3; |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 450 | if (options.forward_agent) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 451 | logit("Agent forwarding disabled for protocol 1.3"); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 452 | options.forward_agent = 0; |
| 453 | } |
| 454 | } |
| 455 | break; |
| 456 | case 2: |
| 457 | if (options.protocol & SSH_PROTO_2) { |
| 458 | enable_compat20(); |
| 459 | break; |
| 460 | } |
| 461 | /* FALLTHROUGH */ |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 462 | default: |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 463 | mismatch = 1; |
| 464 | break; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 465 | } |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 466 | if (mismatch) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 467 | fatal("Protocol major versions differ: %d vs. %d", |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 468 | (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
| 469 | remote_major); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 470 | /* Send our own protocol version identification. */ |
| 471 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 472 | compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 473 | compat20 ? PROTOCOL_MINOR_2 : minor1, |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 474 | SSH_VERSION); |
Darren Tucker | 9f63f22 | 2003-07-03 13:46:56 +1000 | [diff] [blame] | 475 | if (atomicio(vwrite, connection_out, buf, strlen(buf)) != strlen(buf)) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 476 | fatal("write: %.100s", strerror(errno)); |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 477 | client_version_string = xstrdup(buf); |
| 478 | chop(client_version_string); |
| 479 | chop(server_version_string); |
| 480 | debug("Local version string %.100s", client_version_string); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 481 | } |
| 482 | |
Ben Lindstrom | b6c06d9 | 2001-02-10 23:21:09 +0000 | [diff] [blame] | 483 | /* defaults to 'no' */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 484 | static int |
Damien Miller | e398004 | 2001-10-10 15:02:03 +1000 | [diff] [blame] | 485 | confirm(const char *prompt) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 486 | { |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 487 | const char *msg, *again = "Please type 'yes' or 'no': "; |
| 488 | char *p; |
| 489 | int ret = -1; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 490 | |
Ben Lindstrom | b6c06d9 | 2001-02-10 23:21:09 +0000 | [diff] [blame] | 491 | if (options.batch_mode) |
| 492 | return 0; |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 493 | for (msg = prompt;;msg = again) { |
| 494 | p = read_passphrase(msg, RP_ECHO); |
| 495 | if (p == NULL || |
| 496 | (p[0] == '\0') || (p[0] == '\n') || |
| 497 | strncasecmp(p, "no", 2) == 0) |
| 498 | ret = 0; |
Ben Lindstrom | 04f9af7 | 2002-07-04 00:03:56 +0000 | [diff] [blame] | 499 | if (p && strncasecmp(p, "yes", 3) == 0) |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 500 | ret = 1; |
| 501 | if (p) |
| 502 | xfree(p); |
| 503 | if (ret != -1) |
| 504 | return ret; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 505 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 506 | } |
| 507 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 508 | /* |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 509 | * check whether the supplied host key is valid, return -1 if the key |
| 510 | * is not valid. the user_hostfile will not be updated if 'readonly' is true. |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 511 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 512 | static int |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 513 | check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 514 | int readonly, const char *user_hostfile, const char *system_hostfile) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 515 | { |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 516 | Key *file_key; |
Damien Miller | f58b58c | 2003-11-17 21:18:23 +1100 | [diff] [blame] | 517 | const char *type = key_type(host_key); |
Damien Miller | a34a28b | 1999-12-14 10:47:15 +1100 | [diff] [blame] | 518 | char *ip = NULL; |
Ben Lindstrom | cfccef9 | 2001-03-13 04:57:58 +0000 | [diff] [blame] | 519 | char hostline[1000], *hostp, *fp; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 520 | HostStatus host_status; |
| 521 | HostStatus ip_status; |
Damien Miller | 1227d4c | 2005-03-02 12:06:51 +1100 | [diff] [blame] | 522 | int r, local = 0, host_ip_differ = 0; |
Damien Miller | eaf9994 | 2000-01-19 13:45:07 +1100 | [diff] [blame] | 523 | int salen; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 524 | char ntop[NI_MAXHOST]; |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 525 | char msg[1024]; |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 526 | int len, host_line, ip_line; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 527 | const char *host_file = NULL, *ip_file = NULL; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 528 | |
| 529 | /* |
| 530 | * Force accepting of the host key for loopback/localhost. The |
| 531 | * problem is that if the home directory is NFS-mounted to multiple |
| 532 | * machines, localhost will refer to a different machine in each of |
| 533 | * them, and the user will get bogus HOST_CHANGED warnings. This |
| 534 | * essentially disables host authentication for localhost; however, |
| 535 | * this is probably not a real problem. |
| 536 | */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 537 | /** hostaddr == 0! */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 538 | switch (hostaddr->sa_family) { |
| 539 | case AF_INET: |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 540 | local = (ntohl(((struct sockaddr_in *)hostaddr)-> |
Damien Miller | 0dc1bef | 2005-07-17 17:22:45 +1000 | [diff] [blame] | 541 | sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; |
Damien Miller | eaf9994 | 2000-01-19 13:45:07 +1100 | [diff] [blame] | 542 | salen = sizeof(struct sockaddr_in); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 543 | break; |
| 544 | case AF_INET6: |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 545 | local = IN6_IS_ADDR_LOOPBACK( |
| 546 | &(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); |
Damien Miller | eaf9994 | 2000-01-19 13:45:07 +1100 | [diff] [blame] | 547 | salen = sizeof(struct sockaddr_in6); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 548 | break; |
| 549 | default: |
| 550 | local = 0; |
Damien Miller | eaf9994 | 2000-01-19 13:45:07 +1100 | [diff] [blame] | 551 | salen = sizeof(struct sockaddr_storage); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 552 | break; |
| 553 | } |
Ben Lindstrom | 3cecc9a | 2001-10-03 17:39:38 +0000 | [diff] [blame] | 554 | if (options.no_host_authentication_for_localhost == 1 && local && |
| 555 | options.host_key_alias == NULL) { |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 556 | debug("Forcing accepting of host key for " |
| 557 | "loopback/localhost."); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 558 | return 0; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 559 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 560 | |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 561 | /* |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 562 | * We don't have the remote ip-address for connections |
| 563 | * using a proxy command |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 564 | */ |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 565 | if (options.proxy_command == NULL) { |
| 566 | if (getnameinfo(hostaddr, salen, ntop, sizeof(ntop), |
| 567 | NULL, 0, NI_NUMERICHOST) != 0) |
| 568 | fatal("check_host_key: getnameinfo failed"); |
| 569 | ip = xstrdup(ntop); |
| 570 | } else { |
| 571 | ip = xstrdup("<no hostip for proxy command>"); |
| 572 | } |
| 573 | /* |
| 574 | * Turn off check_host_ip if the connection is to localhost, via proxy |
| 575 | * command or if we don't have a hostname to compare with |
| 576 | */ |
| 577 | if (options.check_host_ip && |
| 578 | (local || strcmp(host, ip) == 0 || options.proxy_command != NULL)) |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 579 | options.check_host_ip = 0; |
| 580 | |
Damien Miller | a34a28b | 1999-12-14 10:47:15 +1100 | [diff] [blame] | 581 | /* |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 582 | * Allow the user to record the key under a different name. This is |
Ben Lindstrom | 4dccfa5 | 2000-12-28 16:40:05 +0000 | [diff] [blame] | 583 | * useful for ssh tunneling over forwarded connections or if you run |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 584 | * multiple sshd's on different ports on the same machine. |
Ben Lindstrom | 4dccfa5 | 2000-12-28 16:40:05 +0000 | [diff] [blame] | 585 | */ |
| 586 | if (options.host_key_alias != NULL) { |
| 587 | host = options.host_key_alias; |
| 588 | debug("using hostkeyalias: %s", host); |
| 589 | } |
| 590 | |
| 591 | /* |
Damien Miller | a34a28b | 1999-12-14 10:47:15 +1100 | [diff] [blame] | 592 | * Store the host key from the known host file in here so that we can |
| 593 | * compare it with the key for the IP address. |
| 594 | */ |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 595 | file_key = key_new(host_key->type); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 596 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 597 | /* |
Damien Miller | 788f212 | 2005-11-05 15:14:59 +1100 | [diff] [blame] | 598 | * 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] | 599 | * hosts or in the systemwide list. |
| 600 | */ |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 601 | host_file = user_hostfile; |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 602 | host_status = check_host_in_hostfile(host_file, host, host_key, |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 603 | file_key, &host_line); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 604 | if (host_status == HOST_NEW) { |
| 605 | host_file = system_hostfile; |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 606 | host_status = check_host_in_hostfile(host_file, host, host_key, |
| 607 | file_key, &host_line); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 608 | } |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 609 | /* |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 610 | * Also perform check for the ip address, skip the check if we are |
| 611 | * localhost or the hostname was an ip address to begin with |
| 612 | */ |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 613 | if (options.check_host_ip) { |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 614 | Key *ip_key = key_new(host_key->type); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 615 | |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 616 | ip_file = user_hostfile; |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 617 | ip_status = check_host_in_hostfile(ip_file, ip, host_key, |
| 618 | ip_key, &ip_line); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 619 | if (ip_status == HOST_NEW) { |
| 620 | ip_file = system_hostfile; |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 621 | ip_status = check_host_in_hostfile(ip_file, ip, |
| 622 | host_key, ip_key, &ip_line); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 623 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 624 | if (host_status == HOST_CHANGED && |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 625 | (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key))) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 626 | host_ip_differ = 1; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 627 | |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 628 | key_free(ip_key); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 629 | } else |
| 630 | ip_status = host_status; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 631 | |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 632 | key_free(file_key); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 633 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 634 | switch (host_status) { |
| 635 | case HOST_OK: |
| 636 | /* The host is known and the key matches. */ |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 637 | debug("Host '%.200s' is known and matches the %s host key.", |
| 638 | host, type); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 639 | debug("Found key in %s:%d", host_file, host_line); |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 640 | if (options.check_host_ip && ip_status == HOST_NEW) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 641 | if (readonly) |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 642 | logit("%s host key for IP address " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 643 | "'%.128s' not in list of known hosts.", |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 644 | type, ip); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 645 | else if (!add_host_to_hostfile(user_hostfile, ip, |
Damien Miller | e177615 | 2005-03-01 21:47:37 +1100 | [diff] [blame] | 646 | host_key, options.hash_known_hosts)) |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 647 | logit("Failed to add the %s host key for IP " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 648 | "address '%.128s' to the list of known " |
| 649 | "hosts (%.30s).", type, ip, user_hostfile); |
| 650 | else |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 651 | logit("Warning: Permanently added the %s host " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 652 | "key for IP address '%.128s' to the list " |
| 653 | "of known hosts.", type, ip); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 654 | } |
| 655 | break; |
| 656 | case HOST_NEW: |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 657 | if (readonly) |
| 658 | goto fail; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 659 | /* The host is new. */ |
| 660 | if (options.strict_host_key_checking == 1) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 661 | /* |
| 662 | * User has requested strict host key checking. We |
| 663 | * will not add the host key automatically. The only |
| 664 | * alternative left is to abort. |
| 665 | */ |
| 666 | error("No %s host key is known for %.200s and you " |
| 667 | "have requested strict checking.", type, host); |
| 668 | goto fail; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 669 | } else if (options.strict_host_key_checking == 2) { |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 670 | char msg1[1024], msg2[1024]; |
| 671 | |
| 672 | if (show_other_keys(host, host_key)) |
| 673 | snprintf(msg1, sizeof(msg1), |
Damien Miller | 0dc1bef | 2005-07-17 17:22:45 +1000 | [diff] [blame] | 674 | "\nbut keys of different type are already" |
| 675 | " known for this host."); |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 676 | else |
| 677 | snprintf(msg1, sizeof(msg1), "."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 678 | /* The default */ |
Ben Lindstrom | cfccef9 | 2001-03-13 04:57:58 +0000 | [diff] [blame] | 679 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 680 | msg2[0] = '\0'; |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 681 | if (options.verify_host_key_dns) { |
Damien Miller | 150b557 | 2003-11-17 21:19:29 +1100 | [diff] [blame] | 682 | if (matching_host_key_dns) |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 683 | snprintf(msg2, sizeof(msg2), |
| 684 | "Matching host key fingerprint" |
| 685 | " found in DNS.\n"); |
| 686 | else |
| 687 | snprintf(msg2, sizeof(msg2), |
| 688 | "No matching host key fingerprint" |
| 689 | " found in DNS.\n"); |
| 690 | } |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 691 | snprintf(msg, sizeof(msg), |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 692 | "The authenticity of host '%.200s (%s)' can't be " |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 693 | "established%s\n" |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 694 | "%s key fingerprint is %s.\n%s" |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 695 | "Are you sure you want to continue connecting " |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 696 | "(yes/no)? ", |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 697 | host, ip, msg1, type, fp, msg2); |
Ben Lindstrom | cfccef9 | 2001-03-13 04:57:58 +0000 | [diff] [blame] | 698 | xfree(fp); |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 699 | if (!confirm(msg)) |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 700 | goto fail; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 701 | } |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 702 | /* |
| 703 | * If not in strict mode, add the key automatically to the |
| 704 | * local known_hosts file. |
| 705 | */ |
Damien Miller | 1227d4c | 2005-03-02 12:06:51 +1100 | [diff] [blame] | 706 | if (options.check_host_ip && ip_status == HOST_NEW) { |
| 707 | snprintf(hostline, sizeof(hostline), "%s,%s", |
| 708 | host, ip); |
| 709 | hostp = hostline; |
| 710 | if (options.hash_known_hosts) { |
| 711 | /* Add hash of host and IP separately */ |
| 712 | r = add_host_to_hostfile(user_hostfile, host, |
| 713 | host_key, options.hash_known_hosts) && |
| 714 | add_host_to_hostfile(user_hostfile, ip, |
| 715 | host_key, options.hash_known_hosts); |
| 716 | } else { |
| 717 | /* Add unhashed "host,ip" */ |
| 718 | r = add_host_to_hostfile(user_hostfile, |
| 719 | hostline, host_key, |
| 720 | options.hash_known_hosts); |
| 721 | } |
| 722 | } else { |
| 723 | r = add_host_to_hostfile(user_hostfile, host, host_key, |
| 724 | options.hash_known_hosts); |
| 725 | hostp = host; |
| 726 | } |
| 727 | |
| 728 | if (!r) |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 729 | logit("Failed to add the host to the list of known " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 730 | "hosts (%.500s).", user_hostfile); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 731 | else |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 732 | logit("Warning: Permanently added '%.200s' (%s) to the " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 733 | "list of known hosts.", hostp, type); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 734 | break; |
| 735 | case HOST_CHANGED: |
| 736 | if (options.check_host_ip && host_ip_differ) { |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 737 | char *key_msg; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 738 | if (ip_status == HOST_NEW) |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 739 | key_msg = "is unknown"; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 740 | else if (ip_status == HOST_OK) |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 741 | key_msg = "is unchanged"; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 742 | else |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 743 | key_msg = "has a different value"; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 744 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 745 | error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @"); |
| 746 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 747 | error("The %s host key for %s has changed,", type, host); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 748 | error("and the key for the according IP address %s", ip); |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 749 | error("%s. This could either mean that", key_msg); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 750 | error("DNS SPOOFING is happening or the IP address for the host"); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 751 | error("and its host key have changed at the same time."); |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 752 | if (ip_status != HOST_NEW) |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 753 | error("Offending key for IP in %s:%d", ip_file, ip_line); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 754 | } |
| 755 | /* The host key has changed. */ |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 756 | warn_changed_key(host_key); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 757 | error("Add correct host key in %.100s to get rid of this message.", |
Ben Lindstrom | 4dccfa5 | 2000-12-28 16:40:05 +0000 | [diff] [blame] | 758 | user_hostfile); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 759 | error("Offending key in %s:%d", host_file, host_line); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 760 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 761 | /* |
| 762 | * If strict host key checking is in use, the user will have |
| 763 | * to edit the key manually and we can only abort. |
| 764 | */ |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 765 | if (options.strict_host_key_checking) { |
| 766 | error("%s host key for %.200s has changed and you have " |
| 767 | "requested strict checking.", type, host); |
| 768 | goto fail; |
| 769 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 770 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 771 | /* |
| 772 | * If strict host key checking has not been requested, allow |
Damien Miller | 941ac45 | 2003-06-04 20:31:53 +1000 | [diff] [blame] | 773 | * the connection but without MITM-able authentication or |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 774 | * agent forwarding. |
| 775 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 776 | if (options.password_authentication) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 777 | error("Password authentication is disabled to avoid " |
| 778 | "man-in-the-middle attacks."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 779 | options.password_authentication = 0; |
| 780 | } |
Damien Miller | 941ac45 | 2003-06-04 20:31:53 +1000 | [diff] [blame] | 781 | if (options.kbd_interactive_authentication) { |
| 782 | error("Keyboard-interactive authentication is disabled" |
| 783 | " to avoid man-in-the-middle attacks."); |
| 784 | options.kbd_interactive_authentication = 0; |
| 785 | options.challenge_response_authentication = 0; |
| 786 | } |
| 787 | if (options.challenge_response_authentication) { |
| 788 | error("Challenge/response authentication is disabled" |
| 789 | " to avoid man-in-the-middle attacks."); |
| 790 | options.challenge_response_authentication = 0; |
| 791 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 792 | if (options.forward_agent) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 793 | error("Agent forwarding is disabled to avoid " |
| 794 | "man-in-the-middle attacks."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 795 | options.forward_agent = 0; |
| 796 | } |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 797 | if (options.forward_x11) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 798 | error("X11 forwarding is disabled to avoid " |
| 799 | "man-in-the-middle attacks."); |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 800 | options.forward_x11 = 0; |
| 801 | } |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 802 | if (options.num_local_forwards > 0 || |
| 803 | options.num_remote_forwards > 0) { |
| 804 | error("Port forwarding is disabled to avoid " |
| 805 | "man-in-the-middle attacks."); |
| 806 | options.num_local_forwards = |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 807 | options.num_remote_forwards = 0; |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 808 | } |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 809 | /* |
| 810 | * XXX Should permit the user to change to use the new id. |
| 811 | * This could be done by converting the host key to an |
| 812 | * identifying sentence, tell that the host identifies itself |
| 813 | * by that sentence, and ask the user if he/she whishes to |
| 814 | * accept the authentication. |
| 815 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 816 | break; |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 817 | case HOST_FOUND: |
| 818 | fatal("internal error"); |
| 819 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 820 | } |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 821 | |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 822 | if (options.check_host_ip && host_status != HOST_CHANGED && |
| 823 | ip_status == HOST_CHANGED) { |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 824 | snprintf(msg, sizeof(msg), |
| 825 | "Warning: the %s host key for '%.200s' " |
| 826 | "differs from the key for the IP address '%.128s'" |
| 827 | "\nOffending key for IP in %s:%d", |
| 828 | type, host, ip, ip_file, ip_line); |
| 829 | if (host_status == HOST_OK) { |
| 830 | len = strlen(msg); |
| 831 | snprintf(msg + len, sizeof(msg) - len, |
| 832 | "\nMatching host key in %s:%d", |
Ben Lindstrom | cb72e4f | 2002-06-21 00:41:51 +0000 | [diff] [blame] | 833 | host_file, host_line); |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 834 | } |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 835 | if (options.strict_host_key_checking == 1) { |
Damien Miller | ab2db41 | 2003-06-02 19:09:13 +1000 | [diff] [blame] | 836 | logit("%s", msg); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 837 | error("Exiting, you have requested strict checking."); |
| 838 | goto fail; |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 839 | } else if (options.strict_host_key_checking == 2) { |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 840 | strlcat(msg, "\nAre you sure you want " |
| 841 | "to continue connecting (yes/no)? ", sizeof(msg)); |
| 842 | if (!confirm(msg)) |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 843 | goto fail; |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 844 | } else { |
Damien Miller | ab2db41 | 2003-06-02 19:09:13 +1000 | [diff] [blame] | 845 | logit("%s", msg); |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 846 | } |
| 847 | } |
| 848 | |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 849 | xfree(ip); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 850 | return 0; |
| 851 | |
| 852 | fail: |
| 853 | xfree(ip); |
| 854 | return -1; |
| 855 | } |
| 856 | |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 857 | /* returns 0 if key verifies or -1 if key does NOT verify */ |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 858 | int |
| 859 | verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key) |
| 860 | { |
| 861 | struct stat st; |
Damien Miller | 150b557 | 2003-11-17 21:19:29 +1100 | [diff] [blame] | 862 | int flags = 0; |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 863 | |
Damien Miller | 150b557 | 2003-11-17 21:19:29 +1100 | [diff] [blame] | 864 | if (options.verify_host_key_dns && |
| 865 | verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) { |
| 866 | |
| 867 | if (flags & DNS_VERIFY_FOUND) { |
| 868 | |
| 869 | if (options.verify_host_key_dns == 1 && |
| 870 | flags & DNS_VERIFY_MATCH && |
| 871 | flags & DNS_VERIFY_SECURE) |
| 872 | return 0; |
| 873 | |
| 874 | if (flags & DNS_VERIFY_MATCH) { |
| 875 | matching_host_key_dns = 1; |
| 876 | } else { |
| 877 | warn_changed_key(host_key); |
| 878 | error("Update the SSHFP RR in DNS with the new " |
| 879 | "host key to get rid of this message."); |
| 880 | } |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 881 | } |
| 882 | } |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 883 | |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 884 | /* return ok if the key can be found in an old keyfile */ |
| 885 | if (stat(options.system_hostfile2, &st) == 0 || |
| 886 | stat(options.user_hostfile2, &st) == 0) { |
| 887 | if (check_host_key(host, hostaddr, host_key, /*readonly*/ 1, |
| 888 | options.user_hostfile2, options.system_hostfile2) == 0) |
| 889 | return 0; |
| 890 | } |
| 891 | return check_host_key(host, hostaddr, host_key, /*readonly*/ 0, |
| 892 | options.user_hostfile, options.system_hostfile); |
Damien Miller | a34a28b | 1999-12-14 10:47:15 +1100 | [diff] [blame] | 893 | } |
Damien Miller | 037a0dc | 1999-12-07 15:38:31 +1100 | [diff] [blame] | 894 | |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 895 | /* |
| 896 | * Starts a dialog with the server, and authenticates the current user on the |
| 897 | * server. This does not need any extra privileges. The basic connection |
| 898 | * to the server must already have been established before this is called. |
| 899 | * If login fails, this function prints an error and never returns. |
| 900 | * This function does not require super-user privileges. |
| 901 | */ |
| 902 | void |
Ben Lindstrom | 1bad256 | 2002-06-06 19:57:33 +0000 | [diff] [blame] | 903 | ssh_login(Sensitive *sensitive, const char *orighost, |
Ben Lindstrom | 3fcf1a2 | 2001-04-08 18:26:59 +0000 | [diff] [blame] | 904 | struct sockaddr *hostaddr, struct passwd *pw) |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 905 | { |
| 906 | char *host, *cp; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 907 | char *server_user, *local_user; |
| 908 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 909 | local_user = xstrdup(pw->pw_name); |
| 910 | server_user = options.user ? options.user : local_user; |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 911 | |
| 912 | /* Convert the user-supplied hostname into all lowercase. */ |
| 913 | host = xstrdup(orighost); |
| 914 | for (cp = host; *cp; cp++) |
| 915 | if (isupper(*cp)) |
Damien Miller | 1d2b670 | 2006-03-26 14:09:54 +1100 | [diff] [blame] | 916 | *cp = (char)tolower(*cp); |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 917 | |
| 918 | /* Exchange protocol version identification strings with the server. */ |
| 919 | ssh_exchange_identification(); |
| 920 | |
| 921 | /* Put the connection into non-blocking mode. */ |
| 922 | packet_set_nonblocking(); |
| 923 | |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 924 | /* key exchange */ |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 925 | /* authenticate user */ |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 926 | if (compat20) { |
| 927 | ssh_kex2(host, hostaddr); |
Ben Lindstrom | 1bad256 | 2002-06-06 19:57:33 +0000 | [diff] [blame] | 928 | ssh_userauth2(local_user, server_user, host, sensitive); |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 929 | } else { |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 930 | ssh_kex(host, hostaddr); |
Ben Lindstrom | 1bad256 | 2002-06-06 19:57:33 +0000 | [diff] [blame] | 931 | ssh_userauth1(local_user, server_user, host, sensitive); |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 932 | } |
Damien Miller | 40b5985 | 2006-06-13 13:00:25 +1000 | [diff] [blame] | 933 | xfree(local_user); |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 934 | } |
Damien Miller | 79438cc | 2001-02-16 12:34:57 +1100 | [diff] [blame] | 935 | |
| 936 | void |
| 937 | ssh_put_password(char *password) |
| 938 | { |
| 939 | int size; |
| 940 | char *padded; |
| 941 | |
Ben Lindstrom | d20d0f3 | 2001-03-10 17:22:20 +0000 | [diff] [blame] | 942 | if (datafellows & SSH_BUG_PASSWORDPAD) { |
Ben Lindstrom | 664408d | 2001-06-09 01:42:01 +0000 | [diff] [blame] | 943 | packet_put_cstring(password); |
Ben Lindstrom | d20d0f3 | 2001-03-10 17:22:20 +0000 | [diff] [blame] | 944 | return; |
| 945 | } |
Damien Miller | 79438cc | 2001-02-16 12:34:57 +1100 | [diff] [blame] | 946 | size = roundup(strlen(password) + 1, 32); |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 947 | padded = xcalloc(1, size); |
Damien Miller | 79438cc | 2001-02-16 12:34:57 +1100 | [diff] [blame] | 948 | strlcpy(padded, password, size); |
| 949 | packet_put_string(padded, size); |
| 950 | memset(padded, 0, size); |
| 951 | xfree(padded); |
| 952 | } |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 953 | |
| 954 | static int |
| 955 | show_key_from_file(const char *file, const char *host, int keytype) |
| 956 | { |
| 957 | Key *found; |
| 958 | char *fp; |
| 959 | int line, ret; |
| 960 | |
| 961 | found = key_new(keytype); |
| 962 | if ((ret = lookup_key_in_hostfile_by_type(file, host, |
| 963 | keytype, found, &line))) { |
| 964 | fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX); |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 965 | logit("WARNING: %s key found for host %s\n" |
Ben Lindstrom | 4b99be8 | 2002-08-01 01:26:29 +0000 | [diff] [blame] | 966 | "in %s:%d\n" |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 967 | "%s key fingerprint %s.", |
| 968 | key_type(found), host, file, line, |
| 969 | key_type(found), fp); |
| 970 | xfree(fp); |
| 971 | } |
| 972 | key_free(found); |
| 973 | return (ret); |
| 974 | } |
| 975 | |
| 976 | /* print all known host keys for a given host, but skip keys of given type */ |
| 977 | static int |
| 978 | show_other_keys(const char *host, Key *key) |
| 979 | { |
| 980 | int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1}; |
| 981 | int i, found = 0; |
| 982 | |
| 983 | for (i = 0; type[i] != -1; i++) { |
| 984 | if (type[i] == key->type) |
| 985 | continue; |
| 986 | if (type[i] != KEY_RSA1 && |
| 987 | show_key_from_file(options.user_hostfile2, host, type[i])) { |
| 988 | found = 1; |
| 989 | continue; |
| 990 | } |
| 991 | if (type[i] != KEY_RSA1 && |
| 992 | show_key_from_file(options.system_hostfile2, host, type[i])) { |
| 993 | found = 1; |
| 994 | continue; |
| 995 | } |
| 996 | if (show_key_from_file(options.user_hostfile, host, type[i])) { |
| 997 | found = 1; |
| 998 | continue; |
| 999 | } |
| 1000 | if (show_key_from_file(options.system_hostfile, host, type[i])) { |
| 1001 | found = 1; |
| 1002 | continue; |
| 1003 | } |
| 1004 | debug2("no key of type %d for host %s", type[i], host); |
| 1005 | } |
| 1006 | return (found); |
| 1007 | } |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1008 | |
| 1009 | static void |
| 1010 | warn_changed_key(Key *host_key) |
| 1011 | { |
| 1012 | char *fp; |
Damien Miller | 8f746ec | 2003-11-17 21:11:15 +1100 | [diff] [blame] | 1013 | const char *type = key_type(host_key); |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1014 | |
| 1015 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); |
| 1016 | |
| 1017 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 1018 | error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @"); |
| 1019 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 1020 | error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!"); |
| 1021 | error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!"); |
| 1022 | error("It is also possible that the %s host key has just been changed.", type); |
| 1023 | error("The fingerprint for the %s key sent by the remote host is\n%s.", |
| 1024 | type, fp); |
| 1025 | error("Please contact your system administrator."); |
| 1026 | |
| 1027 | xfree(fp); |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1028 | } |
Damien Miller | d27b947 | 2005-12-13 19:29:02 +1100 | [diff] [blame] | 1029 | |
| 1030 | /* |
| 1031 | * Execute a local command |
| 1032 | */ |
| 1033 | int |
| 1034 | ssh_local_cmd(const char *args) |
| 1035 | { |
| 1036 | char *shell; |
| 1037 | pid_t pid; |
| 1038 | int status; |
| 1039 | |
| 1040 | if (!options.permit_local_command || |
| 1041 | args == NULL || !*args) |
| 1042 | return (1); |
| 1043 | |
| 1044 | if ((shell = getenv("SHELL")) == NULL) |
| 1045 | shell = _PATH_BSHELL; |
| 1046 | |
| 1047 | pid = fork(); |
| 1048 | if (pid == 0) { |
| 1049 | debug3("Executing %s -c \"%s\"", shell, args); |
| 1050 | execl(shell, shell, "-c", args, (char *)NULL); |
| 1051 | error("Couldn't execute %s -c \"%s\": %s", |
| 1052 | shell, args, strerror(errno)); |
| 1053 | _exit(1); |
| 1054 | } else if (pid == -1) |
| 1055 | fatal("fork failed: %.100s", strerror(errno)); |
| 1056 | while (waitpid(pid, &status, 0) == -1) |
| 1057 | if (errno != EINTR) |
| 1058 | fatal("Couldn't wait for child: %s", strerror(errno)); |
| 1059 | |
| 1060 | if (!WIFEXITED(status)) |
| 1061 | return (1); |
| 1062 | |
| 1063 | return (WEXITSTATUS(status)); |
| 1064 | } |