Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
| 3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 4 | * All rights reserved |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 5 | * Code to connect to a remote host, and to perform the client side of the |
| 6 | * login (authentication) dialog. |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 7 | * |
| 8 | * As far as I am concerned, the code I have written for this software |
| 9 | * can be used freely for any purpose. Any derived versions of this |
| 10 | * software must be clearly marked as such, and if the derived work is |
| 11 | * incompatible with the protocol description in the RFC file, it must be |
| 12 | * called by a name other than "ssh" or "Secure Shell". |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 13 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 14 | |
| 15 | #include "includes.h" |
Damien Miller | 0dc1bef | 2005-07-17 17:22:45 +1000 | [diff] [blame^] | 16 | RCSID("$OpenBSD: sshconnect.c,v 1.168 2005/07/17 07:17:55 djm Exp $"); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 17 | |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 18 | #include <openssl/bn.h> |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 19 | |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 20 | #include "ssh.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 21 | #include "xmalloc.h" |
| 22 | #include "rsa.h" |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 23 | #include "buffer.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 24 | #include "packet.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 25 | #include "uidswap.h" |
| 26 | #include "compat.h" |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 27 | #include "key.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 28 | #include "sshconnect.h" |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 29 | #include "hostfile.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 30 | #include "log.h" |
| 31 | #include "readconf.h" |
| 32 | #include "atomicio.h" |
| 33 | #include "misc.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 34 | |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 35 | #include "dns.h" |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 36 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 37 | char *client_version_string = NULL; |
| 38 | char *server_version_string = NULL; |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 39 | |
Damien Miller | 150b557 | 2003-11-17 21:19:29 +1100 | [diff] [blame] | 40 | int matching_host_key_dns = 0; |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 41 | |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 42 | /* import */ |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 43 | extern Options options; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 44 | extern char *__progname; |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 45 | extern uid_t original_real_uid; |
| 46 | extern uid_t original_effective_uid; |
Damien Miller | 8c4e18a | 2002-09-19 12:05:02 +1000 | [diff] [blame] | 47 | extern pid_t proxy_command_pid; |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 48 | |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 49 | #ifndef INET6_ADDRSTRLEN /* for non IPv6 machines */ |
| 50 | #define INET6_ADDRSTRLEN 46 |
| 51 | #endif |
| 52 | |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 53 | static int show_other_keys(const char *, Key *); |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 54 | static void warn_changed_key(Key *); |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 55 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 56 | /* |
| 57 | * Connect to the given ssh server using a proxy command. |
| 58 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 59 | static int |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 60 | 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] | 61 | { |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 62 | char *command_string, *tmp; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 63 | int pin[2], pout[2]; |
Damien Miller | 166fca8 | 2000-04-20 07:42:21 +1000 | [diff] [blame] | 64 | pid_t pid; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 65 | char strport[NI_MAXSERV]; |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 66 | size_t len; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 67 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 68 | /* Convert the port number into a string. */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 69 | snprintf(strport, sizeof strport, "%hu", port); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 70 | |
Damien Miller | 8c4e18a | 2002-09-19 12:05:02 +1000 | [diff] [blame] | 71 | /* |
| 72 | * Build the final command string in the buffer by making the |
| 73 | * appropriate substitutions to the given proxy command. |
| 74 | * |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 75 | * Use "exec" to avoid "sh -c" processes on some platforms |
Damien Miller | 8c4e18a | 2002-09-19 12:05:02 +1000 | [diff] [blame] | 76 | * (e.g. Solaris) |
| 77 | */ |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 78 | len = strlen(proxy_command) + 6; |
| 79 | tmp = xmalloc(len); |
| 80 | strlcpy(tmp, "exec ", len); |
| 81 | strlcat(tmp, proxy_command, len); |
| 82 | command_string = percent_expand(tmp, "h", host, |
| 83 | "p", strport, (char *)NULL); |
| 84 | xfree(tmp); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 85 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 86 | /* Create pipes for communicating with the proxy. */ |
| 87 | if (pipe(pin) < 0 || pipe(pout) < 0) |
| 88 | fatal("Could not create pipes to communicate with the proxy: %.100s", |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 89 | strerror(errno)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 90 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 91 | debug("Executing proxy command: %.500s", command_string); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 92 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 93 | /* Fork and execute the proxy command. */ |
| 94 | if ((pid = fork()) == 0) { |
| 95 | char *argv[10]; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 96 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 97 | /* Child. Permanently give up superuser privileges. */ |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 98 | seteuid(original_real_uid); |
| 99 | setuid(original_real_uid); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 100 | |
| 101 | /* Redirect stdin and stdout. */ |
| 102 | close(pin[1]); |
| 103 | if (pin[0] != 0) { |
| 104 | if (dup2(pin[0], 0) < 0) |
| 105 | perror("dup2 stdin"); |
| 106 | close(pin[0]); |
| 107 | } |
| 108 | close(pout[0]); |
| 109 | if (dup2(pout[1], 1) < 0) |
| 110 | perror("dup2 stdout"); |
| 111 | /* Cannot be 1 because pin allocated two descriptors. */ |
| 112 | close(pout[1]); |
| 113 | |
| 114 | /* Stderr is left as it is so that error messages get |
| 115 | printed on the user's terminal. */ |
Damien Miller | 7b413d2 | 2000-07-01 13:24:21 +1000 | [diff] [blame] | 116 | argv[0] = _PATH_BSHELL; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 117 | argv[1] = "-c"; |
| 118 | argv[2] = command_string; |
| 119 | argv[3] = NULL; |
| 120 | |
| 121 | /* Execute the proxy command. Note that we gave up any |
| 122 | extra privileges above. */ |
Kevin Steves | fcd5d60 | 2001-01-07 11:45:22 +0000 | [diff] [blame] | 123 | execv(argv[0], argv); |
| 124 | perror(argv[0]); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 125 | exit(1); |
| 126 | } |
| 127 | /* Parent. */ |
| 128 | if (pid < 0) |
| 129 | fatal("fork failed: %.100s", strerror(errno)); |
Damien Miller | 8c4e18a | 2002-09-19 12:05:02 +1000 | [diff] [blame] | 130 | else |
| 131 | proxy_command_pid = pid; /* save pid to clean up later */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 132 | |
| 133 | /* Close child side of the descriptors. */ |
| 134 | close(pin[0]); |
| 135 | close(pout[1]); |
| 136 | |
| 137 | /* Free the command name. */ |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 138 | xfree(command_string); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 139 | |
| 140 | /* Set the connection file descriptors. */ |
| 141 | packet_set_connection(pout[0], pin[1]); |
| 142 | |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 143 | /* Indicate OK return */ |
| 144 | return 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 145 | } |
| 146 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 147 | /* |
| 148 | * Creates a (possibly privileged) socket for use as the ssh connection. |
| 149 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 150 | static int |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 151 | ssh_create_socket(int privileged, struct addrinfo *ai) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 152 | { |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 153 | int sock, gaierr; |
| 154 | struct addrinfo hints, *res; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 155 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 156 | /* |
| 157 | * If we are running as root and want to connect to a privileged |
| 158 | * port, bind our own socket to a privileged port. |
| 159 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 160 | if (privileged) { |
| 161 | int p = IPPORT_RESERVED - 1; |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 162 | PRIV_START; |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 163 | sock = rresvport_af(&p, ai->ai_family); |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 164 | PRIV_END; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 165 | if (sock < 0) |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 166 | error("rresvport: af=%d %.100s", ai->ai_family, |
| 167 | strerror(errno)); |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 168 | else |
| 169 | debug("Allocated local port %d.", p); |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 170 | return sock; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 171 | } |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 172 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 173 | if (sock < 0) |
| 174 | error("socket: %.100s", strerror(errno)); |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 175 | |
| 176 | /* Bind the socket to an alternative local IP address */ |
| 177 | if (options.bind_address == NULL) |
| 178 | return sock; |
| 179 | |
| 180 | memset(&hints, 0, sizeof(hints)); |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 181 | hints.ai_family = ai->ai_family; |
| 182 | hints.ai_socktype = ai->ai_socktype; |
| 183 | hints.ai_protocol = ai->ai_protocol; |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 184 | hints.ai_flags = AI_PASSIVE; |
| 185 | gaierr = getaddrinfo(options.bind_address, "0", &hints, &res); |
| 186 | if (gaierr) { |
| 187 | error("getaddrinfo: %s: %s", options.bind_address, |
| 188 | gai_strerror(gaierr)); |
| 189 | close(sock); |
| 190 | return -1; |
| 191 | } |
| 192 | if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) { |
| 193 | error("bind: %s: %s", options.bind_address, strerror(errno)); |
| 194 | close(sock); |
| 195 | freeaddrinfo(res); |
| 196 | return -1; |
| 197 | } |
| 198 | freeaddrinfo(res); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 199 | return sock; |
| 200 | } |
| 201 | |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 202 | static int |
| 203 | timeout_connect(int sockfd, const struct sockaddr *serv_addr, |
| 204 | socklen_t addrlen, int timeout) |
| 205 | { |
| 206 | fd_set *fdset; |
| 207 | struct timeval tv; |
| 208 | socklen_t optlen; |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 209 | int fdsetsz, optval, rc, result = -1; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 210 | |
| 211 | if (timeout <= 0) |
| 212 | return (connect(sockfd, serv_addr, addrlen)); |
| 213 | |
Damien Miller | f6723f0 | 2004-01-27 21:21:27 +1100 | [diff] [blame] | 214 | set_nonblock(sockfd); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 215 | rc = connect(sockfd, serv_addr, addrlen); |
Damien Miller | f6723f0 | 2004-01-27 21:21:27 +1100 | [diff] [blame] | 216 | if (rc == 0) { |
| 217 | unset_nonblock(sockfd); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 218 | return (0); |
Damien Miller | f6723f0 | 2004-01-27 21:21:27 +1100 | [diff] [blame] | 219 | } |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 220 | if (errno != EINPROGRESS) |
| 221 | return (-1); |
| 222 | |
| 223 | fdsetsz = howmany(sockfd + 1, NFDBITS) * sizeof(fd_mask); |
| 224 | fdset = (fd_set *)xmalloc(fdsetsz); |
| 225 | |
Darren Tucker | edeb1f7 | 2003-07-03 13:48:04 +1000 | [diff] [blame] | 226 | memset(fdset, 0, fdsetsz); |
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 | a34a28b | 1999-12-14 10:47:15 +1100 | [diff] [blame] | 309 | /* |
| 310 | * Try to connect several times. On some machines, the first time |
| 311 | * will sometimes fail. In general socket code appears to behave |
| 312 | * quite magically on many machines. |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 313 | */ |
| 314 | for (attempt = 0; ;) { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 315 | if (attempt > 0) |
| 316 | debug("Trying again..."); |
| 317 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 318 | /* Loop through addresses for this host, and try each one in |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 319 | sequence until the connection succeeds. */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 320 | for (ai = aitop; ai; ai = ai->ai_next) { |
| 321 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) |
| 322 | continue; |
| 323 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, |
| 324 | ntop, sizeof(ntop), strport, sizeof(strport), |
| 325 | NI_NUMERICHOST|NI_NUMERICSERV) != 0) { |
| 326 | error("ssh_connect: getnameinfo failed"); |
| 327 | continue; |
| 328 | } |
| 329 | debug("Connecting to %.200s [%.100s] port %s.", |
| 330 | host, ntop, strport); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 331 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 332 | /* Create a socket for connecting. */ |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 333 | sock = ssh_create_socket(needpriv, ai); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 334 | if (sock < 0) |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 335 | /* Any error is already output */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 336 | continue; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 337 | |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 338 | if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen, |
| 339 | options.connection_timeout) >= 0) { |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 340 | /* Successful connection. */ |
Ben Lindstrom | a370005 | 2001-04-05 23:26:32 +0000 | [diff] [blame] | 341 | memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 342 | break; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 343 | } else { |
Ben Lindstrom | 728aa7e | 2002-07-15 17:48:11 +0000 | [diff] [blame] | 344 | debug("connect to address %s port %s: %s", |
| 345 | ntop, strport, strerror(errno)); |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 346 | /* |
| 347 | * Close the failed socket; there appear to |
| 348 | * be some problems when reusing a socket for |
| 349 | * which connect() has already returned an |
| 350 | * error. |
| 351 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 352 | close(sock); |
| 353 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 354 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 355 | if (ai) |
| 356 | break; /* Successful connection. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 357 | |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 358 | attempt++; |
| 359 | if (attempt >= connection_attempts) |
| 360 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 361 | /* Sleep a moment before retrying. */ |
| 362 | sleep(1); |
| 363 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 364 | |
| 365 | freeaddrinfo(aitop); |
| 366 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 367 | /* Return failure if we didn't get a successful connection. */ |
Ben Lindstrom | a6cd75c | 2002-07-11 04:00:19 +0000 | [diff] [blame] | 368 | if (attempt >= connection_attempts) { |
Darren Tucker | b2161e3 | 2005-01-20 11:00:46 +1100 | [diff] [blame] | 369 | error("ssh: connect to host %s port %s: %s", |
Ben Lindstrom | a6cd75c | 2002-07-11 04:00:19 +0000 | [diff] [blame] | 370 | host, strport, strerror(errno)); |
Darren Tucker | b2161e3 | 2005-01-20 11:00:46 +1100 | [diff] [blame] | 371 | return (-1); |
Ben Lindstrom | a6cd75c | 2002-07-11 04:00:19 +0000 | [diff] [blame] | 372 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 373 | |
| 374 | debug("Connection established."); |
| 375 | |
Damien Miller | 12c150e | 2003-12-17 16:31:10 +1100 | [diff] [blame] | 376 | /* Set SO_KEEPALIVE if requested. */ |
| 377 | if (options.tcp_keep_alive && |
Ben Lindstrom | bf555ba | 2001-01-18 02:04:35 +0000 | [diff] [blame] | 378 | setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, |
| 379 | sizeof(on)) < 0) |
| 380 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 381 | |
| 382 | /* Set the connection. */ |
| 383 | packet_set_connection(sock, sock); |
| 384 | |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 385 | return 0; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 386 | } |
| 387 | |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 388 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 389 | * Waits for the server identification string, and sends our own |
| 390 | * identification string. |
| 391 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 392 | static void |
Ben Lindstrom | 31ca54a | 2001-02-09 02:11:24 +0000 | [diff] [blame] | 393 | ssh_exchange_identification(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 394 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 395 | char buf[256], remote_version[256]; /* must be same size! */ |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 396 | int remote_major, remote_minor, mismatch; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 397 | int connection_in = packet_get_connection_in(); |
| 398 | int connection_out = packet_get_connection_out(); |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 399 | int minor1 = PROTOCOL_MINOR_1; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 400 | u_int i; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 401 | |
Damien Miller | b253cc4 | 2005-05-26 12:23:44 +1000 | [diff] [blame] | 402 | /* Read other side's version identification. */ |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 403 | for (;;) { |
| 404 | for (i = 0; i < sizeof(buf) - 1; i++) { |
Damien Miller | b253cc4 | 2005-05-26 12:23:44 +1000 | [diff] [blame] | 405 | size_t len = atomicio(read, connection_in, &buf[i], 1); |
| 406 | |
Damien Miller | 46d38de | 2005-07-17 17:02:09 +1000 | [diff] [blame] | 407 | if (len != 1 && errno == EPIPE) |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 408 | fatal("ssh_exchange_identification: Connection closed by remote host"); |
Damien Miller | b253cc4 | 2005-05-26 12:23:44 +1000 | [diff] [blame] | 409 | else if (len != 1) |
| 410 | fatal("ssh_exchange_identification: read: %.100s", strerror(errno)); |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 411 | if (buf[i] == '\r') { |
| 412 | buf[i] = '\n'; |
| 413 | buf[i + 1] = 0; |
| 414 | continue; /**XXX wait for \n */ |
| 415 | } |
| 416 | if (buf[i] == '\n') { |
| 417 | buf[i + 1] = 0; |
| 418 | break; |
| 419 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 420 | } |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 421 | buf[sizeof(buf) - 1] = 0; |
| 422 | if (strncmp(buf, "SSH-", 4) == 0) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 423 | break; |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 424 | debug("ssh_exchange_identification: %s", buf); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 425 | } |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 426 | server_version_string = xstrdup(buf); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 427 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 428 | /* |
| 429 | * Check that the versions match. In future this might accept |
| 430 | * several versions and set appropriate flags to handle them. |
| 431 | */ |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 432 | if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n", |
| 433 | &remote_major, &remote_minor, remote_version) != 3) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 434 | fatal("Bad remote protocol version identification: '%.100s'", buf); |
| 435 | debug("Remote protocol version %d.%d, remote software version %.100s", |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 436 | remote_major, remote_minor, remote_version); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 437 | |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 438 | compat_datafellows(remote_version); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 439 | mismatch = 0; |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 440 | |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 441 | switch (remote_major) { |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 442 | case 1: |
| 443 | if (remote_minor == 99 && |
| 444 | (options.protocol & SSH_PROTO_2) && |
| 445 | !(options.protocol & SSH_PROTO_1_PREFERRED)) { |
| 446 | enable_compat20(); |
| 447 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 448 | } |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 449 | if (!(options.protocol & SSH_PROTO_1)) { |
| 450 | mismatch = 1; |
| 451 | break; |
| 452 | } |
| 453 | if (remote_minor < 3) { |
| 454 | fatal("Remote machine has too old SSH software version."); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 455 | } else if (remote_minor == 3 || remote_minor == 4) { |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 456 | /* We speak 1.3, too. */ |
| 457 | enable_compat13(); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 458 | minor1 = 3; |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 459 | if (options.forward_agent) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 460 | logit("Agent forwarding disabled for protocol 1.3"); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 461 | options.forward_agent = 0; |
| 462 | } |
| 463 | } |
| 464 | break; |
| 465 | case 2: |
| 466 | if (options.protocol & SSH_PROTO_2) { |
| 467 | enable_compat20(); |
| 468 | break; |
| 469 | } |
| 470 | /* FALLTHROUGH */ |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 471 | default: |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 472 | mismatch = 1; |
| 473 | break; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 474 | } |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 475 | if (mismatch) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 476 | fatal("Protocol major versions differ: %d vs. %d", |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 477 | (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
| 478 | remote_major); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 479 | /* Send our own protocol version identification. */ |
| 480 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 481 | compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 482 | compat20 ? PROTOCOL_MINOR_2 : minor1, |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 483 | SSH_VERSION); |
Darren Tucker | 9f63f22 | 2003-07-03 13:46:56 +1000 | [diff] [blame] | 484 | if (atomicio(vwrite, connection_out, buf, strlen(buf)) != strlen(buf)) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 485 | fatal("write: %.100s", strerror(errno)); |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 486 | client_version_string = xstrdup(buf); |
| 487 | chop(client_version_string); |
| 488 | chop(server_version_string); |
| 489 | debug("Local version string %.100s", client_version_string); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 490 | } |
| 491 | |
Ben Lindstrom | b6c06d9 | 2001-02-10 23:21:09 +0000 | [diff] [blame] | 492 | /* defaults to 'no' */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 493 | static int |
Damien Miller | e398004 | 2001-10-10 15:02:03 +1000 | [diff] [blame] | 494 | confirm(const char *prompt) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 495 | { |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 496 | const char *msg, *again = "Please type 'yes' or 'no': "; |
| 497 | char *p; |
| 498 | int ret = -1; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 499 | |
Ben Lindstrom | b6c06d9 | 2001-02-10 23:21:09 +0000 | [diff] [blame] | 500 | if (options.batch_mode) |
| 501 | return 0; |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 502 | for (msg = prompt;;msg = again) { |
| 503 | p = read_passphrase(msg, RP_ECHO); |
| 504 | if (p == NULL || |
| 505 | (p[0] == '\0') || (p[0] == '\n') || |
| 506 | strncasecmp(p, "no", 2) == 0) |
| 507 | ret = 0; |
Ben Lindstrom | 04f9af7 | 2002-07-04 00:03:56 +0000 | [diff] [blame] | 508 | if (p && strncasecmp(p, "yes", 3) == 0) |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 509 | ret = 1; |
| 510 | if (p) |
| 511 | xfree(p); |
| 512 | if (ret != -1) |
| 513 | return ret; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 514 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 515 | } |
| 516 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 517 | /* |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 518 | * check whether the supplied host key is valid, return -1 if the key |
| 519 | * 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] | 520 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 521 | static int |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 522 | check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 523 | int readonly, const char *user_hostfile, const char *system_hostfile) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 524 | { |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 525 | Key *file_key; |
Damien Miller | f58b58c | 2003-11-17 21:18:23 +1100 | [diff] [blame] | 526 | const char *type = key_type(host_key); |
Damien Miller | a34a28b | 1999-12-14 10:47:15 +1100 | [diff] [blame] | 527 | char *ip = NULL; |
Ben Lindstrom | cfccef9 | 2001-03-13 04:57:58 +0000 | [diff] [blame] | 528 | char hostline[1000], *hostp, *fp; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 529 | HostStatus host_status; |
| 530 | HostStatus ip_status; |
Damien Miller | 1227d4c | 2005-03-02 12:06:51 +1100 | [diff] [blame] | 531 | int r, local = 0, host_ip_differ = 0; |
Damien Miller | eaf9994 | 2000-01-19 13:45:07 +1100 | [diff] [blame] | 532 | int salen; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 533 | char ntop[NI_MAXHOST]; |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 534 | char msg[1024]; |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 535 | int len, host_line, ip_line; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 536 | const char *host_file = NULL, *ip_file = NULL; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 537 | |
| 538 | /* |
| 539 | * Force accepting of the host key for loopback/localhost. The |
| 540 | * problem is that if the home directory is NFS-mounted to multiple |
| 541 | * machines, localhost will refer to a different machine in each of |
| 542 | * them, and the user will get bogus HOST_CHANGED warnings. This |
| 543 | * essentially disables host authentication for localhost; however, |
| 544 | * this is probably not a real problem. |
| 545 | */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 546 | /** hostaddr == 0! */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 547 | switch (hostaddr->sa_family) { |
| 548 | case AF_INET: |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 549 | local = (ntohl(((struct sockaddr_in *)hostaddr)-> |
Damien Miller | 0dc1bef | 2005-07-17 17:22:45 +1000 | [diff] [blame^] | 550 | sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; |
Damien Miller | eaf9994 | 2000-01-19 13:45:07 +1100 | [diff] [blame] | 551 | salen = sizeof(struct sockaddr_in); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 552 | break; |
| 553 | case AF_INET6: |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 554 | local = IN6_IS_ADDR_LOOPBACK( |
| 555 | &(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); |
Damien Miller | eaf9994 | 2000-01-19 13:45:07 +1100 | [diff] [blame] | 556 | salen = sizeof(struct sockaddr_in6); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 557 | break; |
| 558 | default: |
| 559 | local = 0; |
Damien Miller | eaf9994 | 2000-01-19 13:45:07 +1100 | [diff] [blame] | 560 | salen = sizeof(struct sockaddr_storage); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 561 | break; |
| 562 | } |
Ben Lindstrom | 3cecc9a | 2001-10-03 17:39:38 +0000 | [diff] [blame] | 563 | if (options.no_host_authentication_for_localhost == 1 && local && |
| 564 | options.host_key_alias == NULL) { |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 565 | debug("Forcing accepting of host key for " |
| 566 | "loopback/localhost."); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 567 | return 0; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 568 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 569 | |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 570 | /* |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 571 | * We don't have the remote ip-address for connections |
| 572 | * using a proxy command |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 573 | */ |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 574 | if (options.proxy_command == NULL) { |
| 575 | if (getnameinfo(hostaddr, salen, ntop, sizeof(ntop), |
| 576 | NULL, 0, NI_NUMERICHOST) != 0) |
| 577 | fatal("check_host_key: getnameinfo failed"); |
| 578 | ip = xstrdup(ntop); |
| 579 | } else { |
| 580 | ip = xstrdup("<no hostip for proxy command>"); |
| 581 | } |
| 582 | /* |
| 583 | * Turn off check_host_ip if the connection is to localhost, via proxy |
| 584 | * command or if we don't have a hostname to compare with |
| 585 | */ |
| 586 | if (options.check_host_ip && |
| 587 | (local || strcmp(host, ip) == 0 || options.proxy_command != NULL)) |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 588 | options.check_host_ip = 0; |
| 589 | |
Damien Miller | a34a28b | 1999-12-14 10:47:15 +1100 | [diff] [blame] | 590 | /* |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 591 | * 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] | 592 | * useful for ssh tunneling over forwarded connections or if you run |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 593 | * multiple sshd's on different ports on the same machine. |
Ben Lindstrom | 4dccfa5 | 2000-12-28 16:40:05 +0000 | [diff] [blame] | 594 | */ |
| 595 | if (options.host_key_alias != NULL) { |
| 596 | host = options.host_key_alias; |
| 597 | debug("using hostkeyalias: %s", host); |
| 598 | } |
| 599 | |
| 600 | /* |
Damien Miller | a34a28b | 1999-12-14 10:47:15 +1100 | [diff] [blame] | 601 | * Store the host key from the known host file in here so that we can |
| 602 | * compare it with the key for the IP address. |
| 603 | */ |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 604 | file_key = key_new(host_key->type); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 605 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 606 | /* |
| 607 | * Check if the host key is present in the user\'s list of known |
| 608 | * hosts or in the systemwide list. |
| 609 | */ |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 610 | host_file = user_hostfile; |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 611 | host_status = check_host_in_hostfile(host_file, host, host_key, |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 612 | file_key, &host_line); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 613 | if (host_status == HOST_NEW) { |
| 614 | host_file = system_hostfile; |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 615 | host_status = check_host_in_hostfile(host_file, host, host_key, |
| 616 | file_key, &host_line); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 617 | } |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 618 | /* |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 619 | * Also perform check for the ip address, skip the check if we are |
| 620 | * localhost or the hostname was an ip address to begin with |
| 621 | */ |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 622 | if (options.check_host_ip) { |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 623 | Key *ip_key = key_new(host_key->type); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 624 | |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 625 | ip_file = user_hostfile; |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 626 | ip_status = check_host_in_hostfile(ip_file, ip, host_key, |
| 627 | ip_key, &ip_line); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 628 | if (ip_status == HOST_NEW) { |
| 629 | ip_file = system_hostfile; |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 630 | ip_status = check_host_in_hostfile(ip_file, ip, |
| 631 | host_key, ip_key, &ip_line); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 632 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 633 | if (host_status == HOST_CHANGED && |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 634 | (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key))) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 635 | host_ip_differ = 1; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 636 | |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 637 | key_free(ip_key); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 638 | } else |
| 639 | ip_status = host_status; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 640 | |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 641 | key_free(file_key); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 642 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 643 | switch (host_status) { |
| 644 | case HOST_OK: |
| 645 | /* The host is known and the key matches. */ |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 646 | debug("Host '%.200s' is known and matches the %s host key.", |
| 647 | host, type); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 648 | debug("Found key in %s:%d", host_file, host_line); |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 649 | if (options.check_host_ip && ip_status == HOST_NEW) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 650 | if (readonly) |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 651 | logit("%s host key for IP address " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 652 | "'%.128s' not in list of known hosts.", |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 653 | type, ip); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 654 | else if (!add_host_to_hostfile(user_hostfile, ip, |
Damien Miller | e177615 | 2005-03-01 21:47:37 +1100 | [diff] [blame] | 655 | host_key, options.hash_known_hosts)) |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 656 | logit("Failed to add the %s host key for IP " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 657 | "address '%.128s' to the list of known " |
| 658 | "hosts (%.30s).", type, ip, user_hostfile); |
| 659 | else |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 660 | logit("Warning: Permanently added the %s host " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 661 | "key for IP address '%.128s' to the list " |
| 662 | "of known hosts.", type, ip); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 663 | } |
| 664 | break; |
| 665 | case HOST_NEW: |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 666 | if (readonly) |
| 667 | goto fail; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 668 | /* The host is new. */ |
| 669 | if (options.strict_host_key_checking == 1) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 670 | /* |
| 671 | * User has requested strict host key checking. We |
| 672 | * will not add the host key automatically. The only |
| 673 | * alternative left is to abort. |
| 674 | */ |
| 675 | error("No %s host key is known for %.200s and you " |
| 676 | "have requested strict checking.", type, host); |
| 677 | goto fail; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 678 | } else if (options.strict_host_key_checking == 2) { |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 679 | char msg1[1024], msg2[1024]; |
| 680 | |
| 681 | if (show_other_keys(host, host_key)) |
| 682 | snprintf(msg1, sizeof(msg1), |
Damien Miller | 0dc1bef | 2005-07-17 17:22:45 +1000 | [diff] [blame^] | 683 | "\nbut keys of different type are already" |
| 684 | " known for this host."); |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 685 | else |
| 686 | snprintf(msg1, sizeof(msg1), "."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 687 | /* The default */ |
Ben Lindstrom | cfccef9 | 2001-03-13 04:57:58 +0000 | [diff] [blame] | 688 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 689 | msg2[0] = '\0'; |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 690 | if (options.verify_host_key_dns) { |
Damien Miller | 150b557 | 2003-11-17 21:19:29 +1100 | [diff] [blame] | 691 | if (matching_host_key_dns) |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 692 | snprintf(msg2, sizeof(msg2), |
| 693 | "Matching host key fingerprint" |
| 694 | " found in DNS.\n"); |
| 695 | else |
| 696 | snprintf(msg2, sizeof(msg2), |
| 697 | "No matching host key fingerprint" |
| 698 | " found in DNS.\n"); |
| 699 | } |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 700 | snprintf(msg, sizeof(msg), |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 701 | "The authenticity of host '%.200s (%s)' can't be " |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 702 | "established%s\n" |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 703 | "%s key fingerprint is %s.\n%s" |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 704 | "Are you sure you want to continue connecting " |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 705 | "(yes/no)? ", |
Damien Miller | 7392ae6 | 2003-06-11 22:05:25 +1000 | [diff] [blame] | 706 | host, ip, msg1, type, fp, msg2); |
Ben Lindstrom | cfccef9 | 2001-03-13 04:57:58 +0000 | [diff] [blame] | 707 | xfree(fp); |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 708 | if (!confirm(msg)) |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 709 | goto fail; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 710 | } |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 711 | /* |
| 712 | * If not in strict mode, add the key automatically to the |
| 713 | * local known_hosts file. |
| 714 | */ |
Damien Miller | 1227d4c | 2005-03-02 12:06:51 +1100 | [diff] [blame] | 715 | if (options.check_host_ip && ip_status == HOST_NEW) { |
| 716 | snprintf(hostline, sizeof(hostline), "%s,%s", |
| 717 | host, ip); |
| 718 | hostp = hostline; |
| 719 | if (options.hash_known_hosts) { |
| 720 | /* Add hash of host and IP separately */ |
| 721 | r = add_host_to_hostfile(user_hostfile, host, |
| 722 | host_key, options.hash_known_hosts) && |
| 723 | add_host_to_hostfile(user_hostfile, ip, |
| 724 | host_key, options.hash_known_hosts); |
| 725 | } else { |
| 726 | /* Add unhashed "host,ip" */ |
| 727 | r = add_host_to_hostfile(user_hostfile, |
| 728 | hostline, host_key, |
| 729 | options.hash_known_hosts); |
| 730 | } |
| 731 | } else { |
| 732 | r = add_host_to_hostfile(user_hostfile, host, host_key, |
| 733 | options.hash_known_hosts); |
| 734 | hostp = host; |
| 735 | } |
| 736 | |
| 737 | if (!r) |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 738 | logit("Failed to add the host to the list of known " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 739 | "hosts (%.500s).", user_hostfile); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 740 | else |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 741 | logit("Warning: Permanently added '%.200s' (%s) to the " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 742 | "list of known hosts.", hostp, type); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 743 | break; |
| 744 | case HOST_CHANGED: |
| 745 | if (options.check_host_ip && host_ip_differ) { |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 746 | char *key_msg; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 747 | if (ip_status == HOST_NEW) |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 748 | key_msg = "is unknown"; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 749 | else if (ip_status == HOST_OK) |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 750 | key_msg = "is unchanged"; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 751 | else |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 752 | key_msg = "has a different value"; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 753 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 754 | error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @"); |
| 755 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 756 | error("The %s host key for %s has changed,", type, host); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 757 | error("and the key for the according IP address %s", ip); |
Darren Tucker | 3f9fdc7 | 2004-06-22 12:56:01 +1000 | [diff] [blame] | 758 | error("%s. This could either mean that", key_msg); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 759 | error("DNS SPOOFING is happening or the IP address for the host"); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 760 | error("and its host key have changed at the same time."); |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 761 | if (ip_status != HOST_NEW) |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 762 | error("Offending key for IP in %s:%d", ip_file, ip_line); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 763 | } |
| 764 | /* The host key has changed. */ |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 765 | warn_changed_key(host_key); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 766 | 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] | 767 | user_hostfile); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 768 | error("Offending key in %s:%d", host_file, host_line); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 769 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 770 | /* |
| 771 | * If strict host key checking is in use, the user will have |
| 772 | * to edit the key manually and we can only abort. |
| 773 | */ |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 774 | if (options.strict_host_key_checking) { |
| 775 | error("%s host key for %.200s has changed and you have " |
| 776 | "requested strict checking.", type, host); |
| 777 | goto fail; |
| 778 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 779 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 780 | /* |
| 781 | * If strict host key checking has not been requested, allow |
Damien Miller | 941ac45 | 2003-06-04 20:31:53 +1000 | [diff] [blame] | 782 | * the connection but without MITM-able authentication or |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 783 | * agent forwarding. |
| 784 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 785 | if (options.password_authentication) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 786 | error("Password authentication is disabled to avoid " |
| 787 | "man-in-the-middle attacks."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 788 | options.password_authentication = 0; |
| 789 | } |
Damien Miller | 941ac45 | 2003-06-04 20:31:53 +1000 | [diff] [blame] | 790 | if (options.kbd_interactive_authentication) { |
| 791 | error("Keyboard-interactive authentication is disabled" |
| 792 | " to avoid man-in-the-middle attacks."); |
| 793 | options.kbd_interactive_authentication = 0; |
| 794 | options.challenge_response_authentication = 0; |
| 795 | } |
| 796 | if (options.challenge_response_authentication) { |
| 797 | error("Challenge/response authentication is disabled" |
| 798 | " to avoid man-in-the-middle attacks."); |
| 799 | options.challenge_response_authentication = 0; |
| 800 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 801 | if (options.forward_agent) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 802 | error("Agent forwarding is disabled to avoid " |
| 803 | "man-in-the-middle attacks."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 804 | options.forward_agent = 0; |
| 805 | } |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 806 | if (options.forward_x11) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 807 | error("X11 forwarding is disabled to avoid " |
| 808 | "man-in-the-middle attacks."); |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 809 | options.forward_x11 = 0; |
| 810 | } |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 811 | if (options.num_local_forwards > 0 || |
| 812 | options.num_remote_forwards > 0) { |
| 813 | error("Port forwarding is disabled to avoid " |
| 814 | "man-in-the-middle attacks."); |
| 815 | options.num_local_forwards = |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 816 | options.num_remote_forwards = 0; |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 817 | } |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 818 | /* |
| 819 | * XXX Should permit the user to change to use the new id. |
| 820 | * This could be done by converting the host key to an |
| 821 | * identifying sentence, tell that the host identifies itself |
| 822 | * by that sentence, and ask the user if he/she whishes to |
| 823 | * accept the authentication. |
| 824 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 825 | break; |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 826 | case HOST_FOUND: |
| 827 | fatal("internal error"); |
| 828 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 829 | } |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 830 | |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 831 | if (options.check_host_ip && host_status != HOST_CHANGED && |
| 832 | ip_status == HOST_CHANGED) { |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 833 | snprintf(msg, sizeof(msg), |
| 834 | "Warning: the %s host key for '%.200s' " |
| 835 | "differs from the key for the IP address '%.128s'" |
| 836 | "\nOffending key for IP in %s:%d", |
| 837 | type, host, ip, ip_file, ip_line); |
| 838 | if (host_status == HOST_OK) { |
| 839 | len = strlen(msg); |
| 840 | snprintf(msg + len, sizeof(msg) - len, |
| 841 | "\nMatching host key in %s:%d", |
Ben Lindstrom | cb72e4f | 2002-06-21 00:41:51 +0000 | [diff] [blame] | 842 | host_file, host_line); |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 843 | } |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 844 | if (options.strict_host_key_checking == 1) { |
Damien Miller | ab2db41 | 2003-06-02 19:09:13 +1000 | [diff] [blame] | 845 | logit("%s", msg); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 846 | error("Exiting, you have requested strict checking."); |
| 847 | goto fail; |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 848 | } else if (options.strict_host_key_checking == 2) { |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 849 | strlcat(msg, "\nAre you sure you want " |
| 850 | "to continue connecting (yes/no)? ", sizeof(msg)); |
| 851 | if (!confirm(msg)) |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 852 | goto fail; |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 853 | } else { |
Damien Miller | ab2db41 | 2003-06-02 19:09:13 +1000 | [diff] [blame] | 854 | logit("%s", msg); |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 855 | } |
| 856 | } |
| 857 | |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 858 | xfree(ip); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 859 | return 0; |
| 860 | |
| 861 | fail: |
| 862 | xfree(ip); |
| 863 | return -1; |
| 864 | } |
| 865 | |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 866 | /* returns 0 if key verifies or -1 if key does NOT verify */ |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 867 | int |
| 868 | verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key) |
| 869 | { |
| 870 | struct stat st; |
Damien Miller | 150b557 | 2003-11-17 21:19:29 +1100 | [diff] [blame] | 871 | int flags = 0; |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 872 | |
Damien Miller | 150b557 | 2003-11-17 21:19:29 +1100 | [diff] [blame] | 873 | if (options.verify_host_key_dns && |
| 874 | verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) { |
| 875 | |
| 876 | if (flags & DNS_VERIFY_FOUND) { |
| 877 | |
| 878 | if (options.verify_host_key_dns == 1 && |
| 879 | flags & DNS_VERIFY_MATCH && |
| 880 | flags & DNS_VERIFY_SECURE) |
| 881 | return 0; |
| 882 | |
| 883 | if (flags & DNS_VERIFY_MATCH) { |
| 884 | matching_host_key_dns = 1; |
| 885 | } else { |
| 886 | warn_changed_key(host_key); |
| 887 | error("Update the SSHFP RR in DNS with the new " |
| 888 | "host key to get rid of this message."); |
| 889 | } |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 890 | } |
| 891 | } |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 892 | |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 893 | /* return ok if the key can be found in an old keyfile */ |
| 894 | if (stat(options.system_hostfile2, &st) == 0 || |
| 895 | stat(options.user_hostfile2, &st) == 0) { |
| 896 | if (check_host_key(host, hostaddr, host_key, /*readonly*/ 1, |
| 897 | options.user_hostfile2, options.system_hostfile2) == 0) |
| 898 | return 0; |
| 899 | } |
| 900 | return check_host_key(host, hostaddr, host_key, /*readonly*/ 0, |
| 901 | options.user_hostfile, options.system_hostfile); |
Damien Miller | a34a28b | 1999-12-14 10:47:15 +1100 | [diff] [blame] | 902 | } |
Damien Miller | 037a0dc | 1999-12-07 15:38:31 +1100 | [diff] [blame] | 903 | |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 904 | /* |
| 905 | * Starts a dialog with the server, and authenticates the current user on the |
| 906 | * server. This does not need any extra privileges. The basic connection |
| 907 | * to the server must already have been established before this is called. |
| 908 | * If login fails, this function prints an error and never returns. |
| 909 | * This function does not require super-user privileges. |
| 910 | */ |
| 911 | void |
Ben Lindstrom | 1bad256 | 2002-06-06 19:57:33 +0000 | [diff] [blame] | 912 | ssh_login(Sensitive *sensitive, const char *orighost, |
Ben Lindstrom | 3fcf1a2 | 2001-04-08 18:26:59 +0000 | [diff] [blame] | 913 | struct sockaddr *hostaddr, struct passwd *pw) |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 914 | { |
| 915 | char *host, *cp; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 916 | char *server_user, *local_user; |
| 917 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 918 | local_user = xstrdup(pw->pw_name); |
| 919 | server_user = options.user ? options.user : local_user; |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 920 | |
| 921 | /* Convert the user-supplied hostname into all lowercase. */ |
| 922 | host = xstrdup(orighost); |
| 923 | for (cp = host; *cp; cp++) |
| 924 | if (isupper(*cp)) |
| 925 | *cp = tolower(*cp); |
| 926 | |
| 927 | /* Exchange protocol version identification strings with the server. */ |
| 928 | ssh_exchange_identification(); |
| 929 | |
| 930 | /* Put the connection into non-blocking mode. */ |
| 931 | packet_set_nonblocking(); |
| 932 | |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 933 | /* key exchange */ |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 934 | /* authenticate user */ |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 935 | if (compat20) { |
| 936 | ssh_kex2(host, hostaddr); |
Ben Lindstrom | 1bad256 | 2002-06-06 19:57:33 +0000 | [diff] [blame] | 937 | ssh_userauth2(local_user, server_user, host, sensitive); |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 938 | } else { |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 939 | ssh_kex(host, hostaddr); |
Ben Lindstrom | 1bad256 | 2002-06-06 19:57:33 +0000 | [diff] [blame] | 940 | ssh_userauth1(local_user, server_user, host, sensitive); |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 941 | } |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 942 | } |
Damien Miller | 79438cc | 2001-02-16 12:34:57 +1100 | [diff] [blame] | 943 | |
| 944 | void |
| 945 | ssh_put_password(char *password) |
| 946 | { |
| 947 | int size; |
| 948 | char *padded; |
| 949 | |
Ben Lindstrom | d20d0f3 | 2001-03-10 17:22:20 +0000 | [diff] [blame] | 950 | if (datafellows & SSH_BUG_PASSWORDPAD) { |
Ben Lindstrom | 664408d | 2001-06-09 01:42:01 +0000 | [diff] [blame] | 951 | packet_put_cstring(password); |
Ben Lindstrom | d20d0f3 | 2001-03-10 17:22:20 +0000 | [diff] [blame] | 952 | return; |
| 953 | } |
Damien Miller | 79438cc | 2001-02-16 12:34:57 +1100 | [diff] [blame] | 954 | size = roundup(strlen(password) + 1, 32); |
| 955 | padded = xmalloc(size); |
| 956 | memset(padded, 0, size); |
| 957 | strlcpy(padded, password, size); |
| 958 | packet_put_string(padded, size); |
| 959 | memset(padded, 0, size); |
| 960 | xfree(padded); |
| 961 | } |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 962 | |
| 963 | static int |
| 964 | show_key_from_file(const char *file, const char *host, int keytype) |
| 965 | { |
| 966 | Key *found; |
| 967 | char *fp; |
| 968 | int line, ret; |
| 969 | |
| 970 | found = key_new(keytype); |
| 971 | if ((ret = lookup_key_in_hostfile_by_type(file, host, |
| 972 | keytype, found, &line))) { |
| 973 | fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX); |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 974 | logit("WARNING: %s key found for host %s\n" |
Ben Lindstrom | 4b99be8 | 2002-08-01 01:26:29 +0000 | [diff] [blame] | 975 | "in %s:%d\n" |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 976 | "%s key fingerprint %s.", |
| 977 | key_type(found), host, file, line, |
| 978 | key_type(found), fp); |
| 979 | xfree(fp); |
| 980 | } |
| 981 | key_free(found); |
| 982 | return (ret); |
| 983 | } |
| 984 | |
| 985 | /* print all known host keys for a given host, but skip keys of given type */ |
| 986 | static int |
| 987 | show_other_keys(const char *host, Key *key) |
| 988 | { |
| 989 | int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1}; |
| 990 | int i, found = 0; |
| 991 | |
| 992 | for (i = 0; type[i] != -1; i++) { |
| 993 | if (type[i] == key->type) |
| 994 | continue; |
| 995 | if (type[i] != KEY_RSA1 && |
| 996 | show_key_from_file(options.user_hostfile2, host, type[i])) { |
| 997 | found = 1; |
| 998 | continue; |
| 999 | } |
| 1000 | if (type[i] != KEY_RSA1 && |
| 1001 | show_key_from_file(options.system_hostfile2, host, type[i])) { |
| 1002 | found = 1; |
| 1003 | continue; |
| 1004 | } |
| 1005 | if (show_key_from_file(options.user_hostfile, host, type[i])) { |
| 1006 | found = 1; |
| 1007 | continue; |
| 1008 | } |
| 1009 | if (show_key_from_file(options.system_hostfile, host, type[i])) { |
| 1010 | found = 1; |
| 1011 | continue; |
| 1012 | } |
| 1013 | debug2("no key of type %d for host %s", type[i], host); |
| 1014 | } |
| 1015 | return (found); |
| 1016 | } |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1017 | |
| 1018 | static void |
| 1019 | warn_changed_key(Key *host_key) |
| 1020 | { |
| 1021 | char *fp; |
Damien Miller | 8f746ec | 2003-11-17 21:11:15 +1100 | [diff] [blame] | 1022 | const char *type = key_type(host_key); |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1023 | |
| 1024 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); |
| 1025 | |
| 1026 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 1027 | error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @"); |
| 1028 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 1029 | error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!"); |
| 1030 | error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!"); |
| 1031 | error("It is also possible that the %s host key has just been changed.", type); |
| 1032 | error("The fingerprint for the %s key sent by the remote host is\n%s.", |
| 1033 | type, fp); |
| 1034 | error("Please contact your system administrator."); |
| 1035 | |
| 1036 | xfree(fp); |
Damien Miller | 5a38897 | 2003-11-17 21:10:47 +1100 | [diff] [blame] | 1037 | } |