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 | ab2db41 | 2003-06-02 19:09:13 +1000 | [diff] [blame] | 16 | RCSID("$OpenBSD: sshconnect.c,v 1.143 2003/05/26 12:54:40 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 | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 34 | #include "readpass.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 35 | |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 36 | #ifdef DNS |
| 37 | #include "dns.h" |
| 38 | #endif |
| 39 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 40 | char *client_version_string = NULL; |
| 41 | char *server_version_string = NULL; |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 42 | |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 43 | /* import */ |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 44 | extern Options options; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 45 | extern char *__progname; |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 46 | extern uid_t original_real_uid; |
| 47 | extern uid_t original_effective_uid; |
Damien Miller | 8c4e18a | 2002-09-19 12:05:02 +1000 | [diff] [blame] | 48 | extern pid_t proxy_command_pid; |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 49 | |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 50 | #ifndef INET6_ADDRSTRLEN /* for non IPv6 machines */ |
| 51 | #define INET6_ADDRSTRLEN 46 |
| 52 | #endif |
| 53 | |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 54 | static int show_other_keys(const char *, Key *); |
| 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 | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 62 | Buffer command; |
| 63 | const char *cp; |
| 64 | char *command_string; |
| 65 | int pin[2], pout[2]; |
Damien Miller | 166fca8 | 2000-04-20 07:42:21 +1000 | [diff] [blame] | 66 | pid_t pid; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 67 | char strport[NI_MAXSERV]; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 68 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 69 | /* Convert the port number into a string. */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 70 | snprintf(strport, sizeof strport, "%hu", port); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 71 | |
Damien Miller | 8c4e18a | 2002-09-19 12:05:02 +1000 | [diff] [blame] | 72 | /* |
| 73 | * Build the final command string in the buffer by making the |
| 74 | * appropriate substitutions to the given proxy command. |
| 75 | * |
| 76 | * Use "exec" to avoid "sh -c" processes on some platforms |
| 77 | * (e.g. Solaris) |
| 78 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 79 | buffer_init(&command); |
Damien Miller | 8c4e18a | 2002-09-19 12:05:02 +1000 | [diff] [blame] | 80 | buffer_append(&command, "exec ", 5); |
| 81 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 82 | for (cp = proxy_command; *cp; cp++) { |
| 83 | if (cp[0] == '%' && cp[1] == '%') { |
| 84 | buffer_append(&command, "%", 1); |
| 85 | cp++; |
| 86 | continue; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 87 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 88 | if (cp[0] == '%' && cp[1] == 'h') { |
| 89 | buffer_append(&command, host, strlen(host)); |
| 90 | cp++; |
| 91 | continue; |
| 92 | } |
| 93 | if (cp[0] == '%' && cp[1] == 'p') { |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 94 | buffer_append(&command, strport, strlen(strport)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 95 | cp++; |
| 96 | continue; |
| 97 | } |
| 98 | buffer_append(&command, cp, 1); |
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 | buffer_append(&command, "\0", 1); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 101 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 102 | /* Get the final command string. */ |
| 103 | command_string = buffer_ptr(&command); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 104 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 105 | /* Create pipes for communicating with the proxy. */ |
| 106 | if (pipe(pin) < 0 || pipe(pout) < 0) |
| 107 | fatal("Could not create pipes to communicate with the proxy: %.100s", |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 108 | strerror(errno)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 109 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 110 | debug("Executing proxy command: %.500s", command_string); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 111 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 112 | /* Fork and execute the proxy command. */ |
| 113 | if ((pid = fork()) == 0) { |
| 114 | char *argv[10]; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 115 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 116 | /* Child. Permanently give up superuser privileges. */ |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 117 | seteuid(original_real_uid); |
| 118 | setuid(original_real_uid); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 119 | |
| 120 | /* Redirect stdin and stdout. */ |
| 121 | close(pin[1]); |
| 122 | if (pin[0] != 0) { |
| 123 | if (dup2(pin[0], 0) < 0) |
| 124 | perror("dup2 stdin"); |
| 125 | close(pin[0]); |
| 126 | } |
| 127 | close(pout[0]); |
| 128 | if (dup2(pout[1], 1) < 0) |
| 129 | perror("dup2 stdout"); |
| 130 | /* Cannot be 1 because pin allocated two descriptors. */ |
| 131 | close(pout[1]); |
| 132 | |
| 133 | /* Stderr is left as it is so that error messages get |
| 134 | printed on the user's terminal. */ |
Damien Miller | 7b413d2 | 2000-07-01 13:24:21 +1000 | [diff] [blame] | 135 | argv[0] = _PATH_BSHELL; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 136 | argv[1] = "-c"; |
| 137 | argv[2] = command_string; |
| 138 | argv[3] = NULL; |
| 139 | |
| 140 | /* Execute the proxy command. Note that we gave up any |
| 141 | extra privileges above. */ |
Kevin Steves | fcd5d60 | 2001-01-07 11:45:22 +0000 | [diff] [blame] | 142 | execv(argv[0], argv); |
| 143 | perror(argv[0]); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 144 | exit(1); |
| 145 | } |
| 146 | /* Parent. */ |
| 147 | if (pid < 0) |
| 148 | fatal("fork failed: %.100s", strerror(errno)); |
Damien Miller | 8c4e18a | 2002-09-19 12:05:02 +1000 | [diff] [blame] | 149 | else |
| 150 | proxy_command_pid = pid; /* save pid to clean up later */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 151 | |
| 152 | /* Close child side of the descriptors. */ |
| 153 | close(pin[0]); |
| 154 | close(pout[1]); |
| 155 | |
| 156 | /* Free the command name. */ |
| 157 | buffer_free(&command); |
| 158 | |
| 159 | /* Set the connection file descriptors. */ |
| 160 | packet_set_connection(pout[0], pin[1]); |
| 161 | |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 162 | /* Indicate OK return */ |
| 163 | return 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 164 | } |
| 165 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 166 | /* |
| 167 | * Creates a (possibly privileged) socket for use as the ssh connection. |
| 168 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 169 | static int |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 170 | ssh_create_socket(int privileged, struct addrinfo *ai) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 171 | { |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 172 | int sock, gaierr; |
| 173 | struct addrinfo hints, *res; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 174 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 175 | /* |
| 176 | * If we are running as root and want to connect to a privileged |
| 177 | * port, bind our own socket to a privileged port. |
| 178 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 179 | if (privileged) { |
| 180 | int p = IPPORT_RESERVED - 1; |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 181 | PRIV_START; |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 182 | sock = rresvport_af(&p, ai->ai_family); |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 183 | PRIV_END; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 184 | if (sock < 0) |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 185 | error("rresvport: af=%d %.100s", ai->ai_family, |
| 186 | strerror(errno)); |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 187 | else |
| 188 | debug("Allocated local port %d.", p); |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 189 | return sock; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 190 | } |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 191 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 192 | if (sock < 0) |
| 193 | error("socket: %.100s", strerror(errno)); |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 194 | |
| 195 | /* Bind the socket to an alternative local IP address */ |
| 196 | if (options.bind_address == NULL) |
| 197 | return sock; |
| 198 | |
| 199 | memset(&hints, 0, sizeof(hints)); |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 200 | hints.ai_family = ai->ai_family; |
| 201 | hints.ai_socktype = ai->ai_socktype; |
| 202 | hints.ai_protocol = ai->ai_protocol; |
Ben Lindstrom | e0f8804 | 2001-04-30 13:06:24 +0000 | [diff] [blame] | 203 | hints.ai_flags = AI_PASSIVE; |
| 204 | gaierr = getaddrinfo(options.bind_address, "0", &hints, &res); |
| 205 | if (gaierr) { |
| 206 | error("getaddrinfo: %s: %s", options.bind_address, |
| 207 | gai_strerror(gaierr)); |
| 208 | close(sock); |
| 209 | return -1; |
| 210 | } |
| 211 | if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) { |
| 212 | error("bind: %s: %s", options.bind_address, strerror(errno)); |
| 213 | close(sock); |
| 214 | freeaddrinfo(res); |
| 215 | return -1; |
| 216 | } |
| 217 | freeaddrinfo(res); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 218 | return sock; |
| 219 | } |
| 220 | |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 221 | static int |
| 222 | timeout_connect(int sockfd, const struct sockaddr *serv_addr, |
| 223 | socklen_t addrlen, int timeout) |
| 224 | { |
| 225 | fd_set *fdset; |
| 226 | struct timeval tv; |
| 227 | socklen_t optlen; |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 228 | int fdsetsz, optval, rc, result = -1; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 229 | |
| 230 | if (timeout <= 0) |
| 231 | return (connect(sockfd, serv_addr, addrlen)); |
| 232 | |
| 233 | if (fcntl(sockfd, F_SETFL, O_NONBLOCK) < 0) |
| 234 | return (-1); |
| 235 | |
| 236 | rc = connect(sockfd, serv_addr, addrlen); |
| 237 | if (rc == 0) |
| 238 | return (0); |
| 239 | if (errno != EINPROGRESS) |
| 240 | return (-1); |
| 241 | |
| 242 | fdsetsz = howmany(sockfd + 1, NFDBITS) * sizeof(fd_mask); |
| 243 | fdset = (fd_set *)xmalloc(fdsetsz); |
| 244 | |
| 245 | memset(fdset, '\0', fdsetsz); |
| 246 | FD_SET(sockfd, fdset); |
| 247 | tv.tv_sec = timeout; |
| 248 | tv.tv_usec = 0; |
| 249 | |
| 250 | for(;;) { |
| 251 | rc = select(sockfd + 1, NULL, fdset, NULL, &tv); |
| 252 | if (rc != -1 || errno != EINTR) |
| 253 | break; |
| 254 | } |
| 255 | |
| 256 | switch(rc) { |
| 257 | case 0: |
| 258 | /* Timed out */ |
| 259 | errno = ETIMEDOUT; |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 260 | break; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 261 | case -1: |
| 262 | /* Select error */ |
| 263 | debug("select: %s", strerror(errno)); |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 264 | break; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 265 | case 1: |
| 266 | /* Completed or failed */ |
| 267 | optval = 0; |
| 268 | optlen = sizeof(optval); |
| 269 | if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, |
| 270 | &optlen) == -1) |
| 271 | debug("getsockopt: %s", strerror(errno)); |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 272 | break; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 273 | if (optval != 0) { |
| 274 | errno = optval; |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 275 | break; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 276 | } |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 277 | result = 0; |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 278 | break; |
| 279 | default: |
| 280 | /* Should not occur */ |
| 281 | fatal("Bogus return (%d) from select()", rc); |
| 282 | } |
| 283 | |
Damien Miller | 08293fa | 2003-05-23 18:44:41 +1000 | [diff] [blame] | 284 | xfree(fdset); |
| 285 | return (result); |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 286 | } |
| 287 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 288 | /* |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 289 | * Opens a TCP/IP connection to the remote server on the given host. |
| 290 | * The address of the remote host will be returned in hostaddr. |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 291 | * 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] | 292 | * a privileged port will be allocated to make the connection. |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 293 | * This requires super-user privileges if needpriv is true. |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 294 | * Connection_attempts specifies the maximum number of tries (one per |
| 295 | * second). If proxy_command is non-NULL, it specifies the command (with %h |
| 296 | * and %p substituted for host and port, respectively) to use to contact |
| 297 | * the daemon. |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 298 | * Return values: |
| 299 | * 0 for OK |
| 300 | * ECONNREFUSED if we got a "Connection Refused" by the peer on any address |
| 301 | * ECONNABORTED if we failed without a "Connection refused" |
| 302 | * Suitable error messages for the connection failure will already have been |
| 303 | * printed. |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 304 | */ |
| 305 | int |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 306 | ssh_connect(const char *host, struct sockaddr_storage * hostaddr, |
Damien Miller | 139d4cd | 2001-10-10 15:07:44 +1000 | [diff] [blame] | 307 | u_short port, int family, int connection_attempts, |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 308 | int needpriv, const char *proxy_command) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 309 | { |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 310 | int gaierr; |
Ben Lindstrom | bf555ba | 2001-01-18 02:04:35 +0000 | [diff] [blame] | 311 | int on = 1; |
| 312 | int sock = -1, attempt; |
| 313 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
| 314 | struct addrinfo hints, *ai, *aitop; |
Ben Lindstrom | bf555ba | 2001-01-18 02:04:35 +0000 | [diff] [blame] | 315 | struct servent *sp; |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 316 | /* |
| 317 | * Did we get only other errors than "Connection refused" (which |
| 318 | * should block fallback to rsh and similar), or did we get at least |
| 319 | * one "Connection refused"? |
| 320 | */ |
| 321 | int full_failure = 1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 322 | |
Ben Lindstrom | 064496f | 2002-12-23 02:04:22 +0000 | [diff] [blame] | 323 | debug2("ssh_connect: needpriv %d", needpriv); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 324 | |
| 325 | /* Get default port if port has not been set. */ |
| 326 | if (port == 0) { |
| 327 | sp = getservbyname(SSH_SERVICE_NAME, "tcp"); |
| 328 | if (sp) |
| 329 | port = ntohs(sp->s_port); |
| 330 | else |
| 331 | port = SSH_DEFAULT_PORT; |
| 332 | } |
| 333 | /* If a proxy command is given, connect using it. */ |
| 334 | if (proxy_command != NULL) |
Ben Lindstrom | f9c4884 | 2002-06-11 16:37:51 +0000 | [diff] [blame] | 335 | return ssh_proxy_connect(host, port, proxy_command); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 336 | |
| 337 | /* No proxy command. */ |
| 338 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 339 | memset(&hints, 0, sizeof(hints)); |
Damien Miller | 139d4cd | 2001-10-10 15:07:44 +1000 | [diff] [blame] | 340 | hints.ai_family = family; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 341 | hints.ai_socktype = SOCK_STREAM; |
Ben Lindstrom | 5c38552 | 2002-06-23 21:23:20 +0000 | [diff] [blame] | 342 | snprintf(strport, sizeof strport, "%u", port); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 343 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) |
| 344 | fatal("%s: %.100s: %s", __progname, host, |
| 345 | gai_strerror(gaierr)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 346 | |
Damien Miller | a34a28b | 1999-12-14 10:47:15 +1100 | [diff] [blame] | 347 | /* |
| 348 | * Try to connect several times. On some machines, the first time |
| 349 | * will sometimes fail. In general socket code appears to behave |
| 350 | * quite magically on many machines. |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 351 | */ |
| 352 | for (attempt = 0; ;) { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 353 | if (attempt > 0) |
| 354 | debug("Trying again..."); |
| 355 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 356 | /* Loop through addresses for this host, and try each one in |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 357 | sequence until the connection succeeds. */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 358 | for (ai = aitop; ai; ai = ai->ai_next) { |
| 359 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) |
| 360 | continue; |
| 361 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, |
| 362 | ntop, sizeof(ntop), strport, sizeof(strport), |
| 363 | NI_NUMERICHOST|NI_NUMERICSERV) != 0) { |
| 364 | error("ssh_connect: getnameinfo failed"); |
| 365 | continue; |
| 366 | } |
| 367 | debug("Connecting to %.200s [%.100s] port %s.", |
| 368 | host, ntop, strport); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 369 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 370 | /* Create a socket for connecting. */ |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 371 | sock = ssh_create_socket(needpriv, ai); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 372 | if (sock < 0) |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 373 | /* Any error is already output */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 374 | continue; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 375 | |
Damien Miller | b78d5eb | 2003-05-16 11:39:04 +1000 | [diff] [blame] | 376 | if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen, |
| 377 | options.connection_timeout) >= 0) { |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 378 | /* Successful connection. */ |
Ben Lindstrom | a370005 | 2001-04-05 23:26:32 +0000 | [diff] [blame] | 379 | memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 380 | break; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 381 | } else { |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 382 | if (errno == ECONNREFUSED) |
| 383 | full_failure = 0; |
Ben Lindstrom | 728aa7e | 2002-07-15 17:48:11 +0000 | [diff] [blame] | 384 | debug("connect to address %s port %s: %s", |
| 385 | ntop, strport, strerror(errno)); |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 386 | /* |
| 387 | * Close the failed socket; there appear to |
| 388 | * be some problems when reusing a socket for |
| 389 | * which connect() has already returned an |
| 390 | * error. |
| 391 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 392 | close(sock); |
| 393 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 394 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 395 | if (ai) |
| 396 | break; /* Successful connection. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 397 | |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 398 | attempt++; |
| 399 | if (attempt >= connection_attempts) |
| 400 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 401 | /* Sleep a moment before retrying. */ |
| 402 | sleep(1); |
| 403 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 404 | |
| 405 | freeaddrinfo(aitop); |
| 406 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 407 | /* Return failure if we didn't get a successful connection. */ |
Ben Lindstrom | a6cd75c | 2002-07-11 04:00:19 +0000 | [diff] [blame] | 408 | if (attempt >= connection_attempts) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 409 | logit("ssh: connect to host %s port %s: %s", |
Ben Lindstrom | a6cd75c | 2002-07-11 04:00:19 +0000 | [diff] [blame] | 410 | host, strport, strerror(errno)); |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 411 | return full_failure ? ECONNABORTED : ECONNREFUSED; |
Ben Lindstrom | a6cd75c | 2002-07-11 04:00:19 +0000 | [diff] [blame] | 412 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 413 | |
| 414 | debug("Connection established."); |
| 415 | |
Ben Lindstrom | bf555ba | 2001-01-18 02:04:35 +0000 | [diff] [blame] | 416 | /* Set keepalives if requested. */ |
| 417 | if (options.keepalives && |
| 418 | setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, |
| 419 | sizeof(on)) < 0) |
| 420 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 421 | |
| 422 | /* Set the connection. */ |
| 423 | packet_set_connection(sock, sock); |
| 424 | |
Ben Lindstrom | f9cedb9 | 2001-08-06 21:07:11 +0000 | [diff] [blame] | 425 | return 0; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 426 | } |
| 427 | |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 428 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 429 | * Waits for the server identification string, and sends our own |
| 430 | * identification string. |
| 431 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 432 | static void |
Ben Lindstrom | 31ca54a | 2001-02-09 02:11:24 +0000 | [diff] [blame] | 433 | ssh_exchange_identification(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 434 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 435 | char buf[256], remote_version[256]; /* must be same size! */ |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 436 | int remote_major, remote_minor, i, mismatch; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 437 | int connection_in = packet_get_connection_in(); |
| 438 | int connection_out = packet_get_connection_out(); |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 439 | int minor1 = PROTOCOL_MINOR_1; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 440 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 441 | /* Read other side\'s version identification. */ |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 442 | for (;;) { |
| 443 | for (i = 0; i < sizeof(buf) - 1; i++) { |
| 444 | int len = atomicio(read, connection_in, &buf[i], 1); |
| 445 | if (len < 0) |
| 446 | fatal("ssh_exchange_identification: read: %.100s", strerror(errno)); |
| 447 | if (len != 1) |
| 448 | fatal("ssh_exchange_identification: Connection closed by remote host"); |
| 449 | if (buf[i] == '\r') { |
| 450 | buf[i] = '\n'; |
| 451 | buf[i + 1] = 0; |
| 452 | continue; /**XXX wait for \n */ |
| 453 | } |
| 454 | if (buf[i] == '\n') { |
| 455 | buf[i + 1] = 0; |
| 456 | break; |
| 457 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 458 | } |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 459 | buf[sizeof(buf) - 1] = 0; |
| 460 | if (strncmp(buf, "SSH-", 4) == 0) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 461 | break; |
Damien Miller | f6d9e22 | 2000-06-18 14:50:44 +1000 | [diff] [blame] | 462 | debug("ssh_exchange_identification: %s", buf); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 463 | } |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 464 | server_version_string = xstrdup(buf); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 465 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 466 | /* |
| 467 | * Check that the versions match. In future this might accept |
| 468 | * several versions and set appropriate flags to handle them. |
| 469 | */ |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 470 | if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n", |
| 471 | &remote_major, &remote_minor, remote_version) != 3) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 472 | fatal("Bad remote protocol version identification: '%.100s'", buf); |
| 473 | debug("Remote protocol version %d.%d, remote software version %.100s", |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 474 | remote_major, remote_minor, remote_version); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 475 | |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 476 | compat_datafellows(remote_version); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 477 | mismatch = 0; |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 478 | |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 479 | switch (remote_major) { |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 480 | case 1: |
| 481 | if (remote_minor == 99 && |
| 482 | (options.protocol & SSH_PROTO_2) && |
| 483 | !(options.protocol & SSH_PROTO_1_PREFERRED)) { |
| 484 | enable_compat20(); |
| 485 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 486 | } |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 487 | if (!(options.protocol & SSH_PROTO_1)) { |
| 488 | mismatch = 1; |
| 489 | break; |
| 490 | } |
| 491 | if (remote_minor < 3) { |
| 492 | fatal("Remote machine has too old SSH software version."); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 493 | } else if (remote_minor == 3 || remote_minor == 4) { |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 494 | /* We speak 1.3, too. */ |
| 495 | enable_compat13(); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 496 | minor1 = 3; |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 497 | if (options.forward_agent) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 498 | logit("Agent forwarding disabled for protocol 1.3"); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 499 | options.forward_agent = 0; |
| 500 | } |
| 501 | } |
| 502 | break; |
| 503 | case 2: |
| 504 | if (options.protocol & SSH_PROTO_2) { |
| 505 | enable_compat20(); |
| 506 | break; |
| 507 | } |
| 508 | /* FALLTHROUGH */ |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 509 | default: |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 510 | mismatch = 1; |
| 511 | break; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 512 | } |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 513 | if (mismatch) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 514 | fatal("Protocol major versions differ: %d vs. %d", |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 515 | (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
| 516 | remote_major); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 517 | /* Send our own protocol version identification. */ |
| 518 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 519 | compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 520 | compat20 ? PROTOCOL_MINOR_2 : minor1, |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 521 | SSH_VERSION); |
Damien Miller | 037a0dc | 1999-12-07 15:38:31 +1100 | [diff] [blame] | 522 | if (atomicio(write, connection_out, buf, strlen(buf)) != strlen(buf)) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 523 | fatal("write: %.100s", strerror(errno)); |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 524 | client_version_string = xstrdup(buf); |
| 525 | chop(client_version_string); |
| 526 | chop(server_version_string); |
| 527 | debug("Local version string %.100s", client_version_string); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 528 | } |
| 529 | |
Ben Lindstrom | b6c06d9 | 2001-02-10 23:21:09 +0000 | [diff] [blame] | 530 | /* defaults to 'no' */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 531 | static int |
Damien Miller | e398004 | 2001-10-10 15:02:03 +1000 | [diff] [blame] | 532 | confirm(const char *prompt) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 533 | { |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 534 | const char *msg, *again = "Please type 'yes' or 'no': "; |
| 535 | char *p; |
| 536 | int ret = -1; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 537 | |
Ben Lindstrom | b6c06d9 | 2001-02-10 23:21:09 +0000 | [diff] [blame] | 538 | if (options.batch_mode) |
| 539 | return 0; |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 540 | for (msg = prompt;;msg = again) { |
| 541 | p = read_passphrase(msg, RP_ECHO); |
| 542 | if (p == NULL || |
| 543 | (p[0] == '\0') || (p[0] == '\n') || |
| 544 | strncasecmp(p, "no", 2) == 0) |
| 545 | ret = 0; |
Ben Lindstrom | 04f9af7 | 2002-07-04 00:03:56 +0000 | [diff] [blame] | 546 | if (p && strncasecmp(p, "yes", 3) == 0) |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 547 | ret = 1; |
| 548 | if (p) |
| 549 | xfree(p); |
| 550 | if (ret != -1) |
| 551 | return ret; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 552 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 553 | } |
| 554 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 555 | /* |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 556 | * check whether the supplied host key is valid, return -1 if the key |
| 557 | * 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] | 558 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 559 | static int |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 560 | check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 561 | int readonly, const char *user_hostfile, const char *system_hostfile) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 562 | { |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 563 | Key *file_key; |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 564 | char *type = key_type(host_key); |
Damien Miller | a34a28b | 1999-12-14 10:47:15 +1100 | [diff] [blame] | 565 | char *ip = NULL; |
Ben Lindstrom | cfccef9 | 2001-03-13 04:57:58 +0000 | [diff] [blame] | 566 | char hostline[1000], *hostp, *fp; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 567 | HostStatus host_status; |
| 568 | HostStatus ip_status; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 569 | int local = 0, host_ip_differ = 0; |
Damien Miller | eaf9994 | 2000-01-19 13:45:07 +1100 | [diff] [blame] | 570 | int salen; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 571 | char ntop[NI_MAXHOST]; |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 572 | char msg[1024]; |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 573 | int len, host_line, ip_line, has_keys; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 574 | const char *host_file = NULL, *ip_file = NULL; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 575 | |
| 576 | /* |
| 577 | * Force accepting of the host key for loopback/localhost. The |
| 578 | * problem is that if the home directory is NFS-mounted to multiple |
| 579 | * machines, localhost will refer to a different machine in each of |
| 580 | * them, and the user will get bogus HOST_CHANGED warnings. This |
| 581 | * essentially disables host authentication for localhost; however, |
| 582 | * this is probably not a real problem. |
| 583 | */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 584 | /** hostaddr == 0! */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 585 | switch (hostaddr->sa_family) { |
| 586 | case AF_INET: |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 587 | local = (ntohl(((struct sockaddr_in *)hostaddr)-> |
Kevin Steves | 399ec97 | 2002-03-05 18:59:45 +0000 | [diff] [blame] | 588 | sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; |
Damien Miller | eaf9994 | 2000-01-19 13:45:07 +1100 | [diff] [blame] | 589 | salen = sizeof(struct sockaddr_in); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 590 | break; |
| 591 | case AF_INET6: |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 592 | local = IN6_IS_ADDR_LOOPBACK( |
| 593 | &(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); |
Damien Miller | eaf9994 | 2000-01-19 13:45:07 +1100 | [diff] [blame] | 594 | salen = sizeof(struct sockaddr_in6); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 595 | break; |
| 596 | default: |
| 597 | local = 0; |
Damien Miller | eaf9994 | 2000-01-19 13:45:07 +1100 | [diff] [blame] | 598 | salen = sizeof(struct sockaddr_storage); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 599 | break; |
| 600 | } |
Ben Lindstrom | 3cecc9a | 2001-10-03 17:39:38 +0000 | [diff] [blame] | 601 | if (options.no_host_authentication_for_localhost == 1 && local && |
| 602 | options.host_key_alias == NULL) { |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 603 | debug("Forcing accepting of host key for " |
| 604 | "loopback/localhost."); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 605 | return 0; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 606 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 607 | |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 608 | /* |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 609 | * We don't have the remote ip-address for connections |
| 610 | * using a proxy command |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 611 | */ |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 612 | if (options.proxy_command == NULL) { |
| 613 | if (getnameinfo(hostaddr, salen, ntop, sizeof(ntop), |
| 614 | NULL, 0, NI_NUMERICHOST) != 0) |
| 615 | fatal("check_host_key: getnameinfo failed"); |
| 616 | ip = xstrdup(ntop); |
| 617 | } else { |
| 618 | ip = xstrdup("<no hostip for proxy command>"); |
| 619 | } |
| 620 | /* |
| 621 | * Turn off check_host_ip if the connection is to localhost, via proxy |
| 622 | * command or if we don't have a hostname to compare with |
| 623 | */ |
| 624 | if (options.check_host_ip && |
| 625 | (local || strcmp(host, ip) == 0 || options.proxy_command != NULL)) |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 626 | options.check_host_ip = 0; |
| 627 | |
Damien Miller | a34a28b | 1999-12-14 10:47:15 +1100 | [diff] [blame] | 628 | /* |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 629 | * 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] | 630 | * useful for ssh tunneling over forwarded connections or if you run |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 631 | * multiple sshd's on different ports on the same machine. |
Ben Lindstrom | 4dccfa5 | 2000-12-28 16:40:05 +0000 | [diff] [blame] | 632 | */ |
| 633 | if (options.host_key_alias != NULL) { |
| 634 | host = options.host_key_alias; |
| 635 | debug("using hostkeyalias: %s", host); |
| 636 | } |
| 637 | |
| 638 | /* |
Damien Miller | a34a28b | 1999-12-14 10:47:15 +1100 | [diff] [blame] | 639 | * Store the host key from the known host file in here so that we can |
| 640 | * compare it with the key for the IP address. |
| 641 | */ |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 642 | file_key = key_new(host_key->type); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 643 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 644 | /* |
| 645 | * Check if the host key is present in the user\'s list of known |
| 646 | * hosts or in the systemwide list. |
| 647 | */ |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 648 | host_file = user_hostfile; |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 649 | host_status = check_host_in_hostfile(host_file, host, host_key, |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 650 | file_key, &host_line); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 651 | if (host_status == HOST_NEW) { |
| 652 | host_file = system_hostfile; |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 653 | host_status = check_host_in_hostfile(host_file, host, host_key, |
| 654 | file_key, &host_line); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 655 | } |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 656 | /* |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 657 | * Also perform check for the ip address, skip the check if we are |
| 658 | * localhost or the hostname was an ip address to begin with |
| 659 | */ |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 660 | if (options.check_host_ip) { |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 661 | Key *ip_key = key_new(host_key->type); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 662 | |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 663 | ip_file = user_hostfile; |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 664 | ip_status = check_host_in_hostfile(ip_file, ip, host_key, |
| 665 | ip_key, &ip_line); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 666 | if (ip_status == HOST_NEW) { |
| 667 | ip_file = system_hostfile; |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 668 | ip_status = check_host_in_hostfile(ip_file, ip, |
| 669 | host_key, ip_key, &ip_line); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 670 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 671 | if (host_status == HOST_CHANGED && |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 672 | (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key))) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 673 | host_ip_differ = 1; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 674 | |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 675 | key_free(ip_key); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 676 | } else |
| 677 | ip_status = host_status; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 678 | |
Damien Miller | 450a7a1 | 2000-03-26 13:04:51 +1000 | [diff] [blame] | 679 | key_free(file_key); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 680 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 681 | switch (host_status) { |
| 682 | case HOST_OK: |
| 683 | /* The host is known and the key matches. */ |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 684 | debug("Host '%.200s' is known and matches the %s host key.", |
| 685 | host, type); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 686 | debug("Found key in %s:%d", host_file, host_line); |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 687 | if (options.check_host_ip && ip_status == HOST_NEW) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 688 | if (readonly) |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 689 | logit("%s host key for IP address " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 690 | "'%.128s' not in list of known hosts.", |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 691 | type, ip); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 692 | else if (!add_host_to_hostfile(user_hostfile, ip, |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 693 | host_key)) |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 694 | logit("Failed to add the %s host key for IP " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 695 | "address '%.128s' to the list of known " |
| 696 | "hosts (%.30s).", type, ip, user_hostfile); |
| 697 | else |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 698 | logit("Warning: Permanently added the %s host " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 699 | "key for IP address '%.128s' to the list " |
| 700 | "of known hosts.", type, ip); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 701 | } |
| 702 | break; |
| 703 | case HOST_NEW: |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 704 | if (readonly) |
| 705 | goto fail; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 706 | /* The host is new. */ |
| 707 | if (options.strict_host_key_checking == 1) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 708 | /* |
| 709 | * User has requested strict host key checking. We |
| 710 | * will not add the host key automatically. The only |
| 711 | * alternative left is to abort. |
| 712 | */ |
| 713 | error("No %s host key is known for %.200s and you " |
| 714 | "have requested strict checking.", type, host); |
| 715 | goto fail; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 716 | } else if (options.strict_host_key_checking == 2) { |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 717 | has_keys = show_other_keys(host, host_key); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 718 | /* The default */ |
Ben Lindstrom | cfccef9 | 2001-03-13 04:57:58 +0000 | [diff] [blame] | 719 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 720 | snprintf(msg, sizeof(msg), |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 721 | "The authenticity of host '%.200s (%s)' can't be " |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 722 | "established%s\n" |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 723 | "%s key fingerprint is %s.\n" |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 724 | "Are you sure you want to continue connecting " |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 725 | "(yes/no)? ", |
Ben Lindstrom | 93576d9 | 2002-12-23 02:06:19 +0000 | [diff] [blame] | 726 | host, ip, |
| 727 | has_keys ? ",\nbut keys of different type are already " |
| 728 | "known for this host." : ".", |
| 729 | type, fp); |
Ben Lindstrom | cfccef9 | 2001-03-13 04:57:58 +0000 | [diff] [blame] | 730 | xfree(fp); |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 731 | if (!confirm(msg)) |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 732 | goto fail; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 733 | } |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 734 | if (options.check_host_ip && ip_status == HOST_NEW) { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 735 | snprintf(hostline, sizeof(hostline), "%s,%s", host, ip); |
| 736 | hostp = hostline; |
| 737 | } else |
| 738 | hostp = host; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 739 | |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 740 | /* |
| 741 | * If not in strict mode, add the key automatically to the |
| 742 | * local known_hosts file. |
| 743 | */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 744 | if (!add_host_to_hostfile(user_hostfile, hostp, host_key)) |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 745 | logit("Failed to add the host to the list of known " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 746 | "hosts (%.500s).", user_hostfile); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 747 | else |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 748 | logit("Warning: Permanently added '%.200s' (%s) to the " |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 749 | "list of known hosts.", hostp, type); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 750 | break; |
| 751 | case HOST_CHANGED: |
| 752 | if (options.check_host_ip && host_ip_differ) { |
| 753 | char *msg; |
| 754 | if (ip_status == HOST_NEW) |
| 755 | msg = "is unknown"; |
| 756 | else if (ip_status == HOST_OK) |
| 757 | msg = "is unchanged"; |
| 758 | else |
| 759 | msg = "has a different value"; |
| 760 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 761 | error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @"); |
| 762 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 763 | error("The %s host key for %s has changed,", type, host); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 764 | error("and the key for the according IP address %s", ip); |
| 765 | error("%s. This could either mean that", msg); |
| 766 | error("DNS SPOOFING is happening or the IP address for the host"); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 767 | error("and its host key have changed at the same time."); |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 768 | if (ip_status != HOST_NEW) |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 769 | error("Offending key for IP in %s:%d", ip_file, ip_line); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 770 | } |
| 771 | /* The host key has changed. */ |
Ben Lindstrom | cfccef9 | 2001-03-13 04:57:58 +0000 | [diff] [blame] | 772 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 773 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
Damien Miller | f039bad | 1999-12-21 20:57:20 +1100 | [diff] [blame] | 774 | error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @"); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 775 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
| 776 | error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!"); |
| 777 | error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!"); |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 778 | error("It is also possible that the %s host key has just been changed.", type); |
Ben Lindstrom | 4dccfa5 | 2000-12-28 16:40:05 +0000 | [diff] [blame] | 779 | error("The fingerprint for the %s key sent by the remote host is\n%s.", |
Ben Lindstrom | cfccef9 | 2001-03-13 04:57:58 +0000 | [diff] [blame] | 780 | type, fp); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 781 | error("Please contact your system administrator."); |
| 782 | 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] | 783 | user_hostfile); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 784 | error("Offending key in %s:%d", host_file, host_line); |
Ben Lindstrom | cfccef9 | 2001-03-13 04:57:58 +0000 | [diff] [blame] | 785 | xfree(fp); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 786 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 787 | /* |
| 788 | * If strict host key checking is in use, the user will have |
| 789 | * to edit the key manually and we can only abort. |
| 790 | */ |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 791 | if (options.strict_host_key_checking) { |
| 792 | error("%s host key for %.200s has changed and you have " |
| 793 | "requested strict checking.", type, host); |
| 794 | goto fail; |
| 795 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 796 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 797 | /* |
| 798 | * If strict host key checking has not been requested, allow |
| 799 | * the connection but without password authentication or |
| 800 | * agent forwarding. |
| 801 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 802 | if (options.password_authentication) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 803 | error("Password authentication is disabled to avoid " |
| 804 | "man-in-the-middle attacks."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 805 | options.password_authentication = 0; |
| 806 | } |
| 807 | if (options.forward_agent) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 808 | error("Agent forwarding is disabled to avoid " |
| 809 | "man-in-the-middle attacks."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 810 | options.forward_agent = 0; |
| 811 | } |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 812 | if (options.forward_x11) { |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 813 | error("X11 forwarding is disabled to avoid " |
| 814 | "man-in-the-middle attacks."); |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 815 | options.forward_x11 = 0; |
| 816 | } |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 817 | if (options.num_local_forwards > 0 || |
| 818 | options.num_remote_forwards > 0) { |
| 819 | error("Port forwarding is disabled to avoid " |
| 820 | "man-in-the-middle attacks."); |
| 821 | options.num_local_forwards = |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 822 | options.num_remote_forwards = 0; |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 823 | } |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 824 | /* |
| 825 | * XXX Should permit the user to change to use the new id. |
| 826 | * This could be done by converting the host key to an |
| 827 | * identifying sentence, tell that the host identifies itself |
| 828 | * by that sentence, and ask the user if he/she whishes to |
| 829 | * accept the authentication. |
| 830 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 831 | break; |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 832 | case HOST_FOUND: |
| 833 | fatal("internal error"); |
| 834 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 835 | } |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 836 | |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 837 | if (options.check_host_ip && host_status != HOST_CHANGED && |
| 838 | ip_status == HOST_CHANGED) { |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 839 | snprintf(msg, sizeof(msg), |
| 840 | "Warning: the %s host key for '%.200s' " |
| 841 | "differs from the key for the IP address '%.128s'" |
| 842 | "\nOffending key for IP in %s:%d", |
| 843 | type, host, ip, ip_file, ip_line); |
| 844 | if (host_status == HOST_OK) { |
| 845 | len = strlen(msg); |
| 846 | snprintf(msg + len, sizeof(msg) - len, |
| 847 | "\nMatching host key in %s:%d", |
Ben Lindstrom | cb72e4f | 2002-06-21 00:41:51 +0000 | [diff] [blame] | 848 | host_file, host_line); |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 849 | } |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 850 | if (options.strict_host_key_checking == 1) { |
Damien Miller | ab2db41 | 2003-06-02 19:09:13 +1000 | [diff] [blame] | 851 | logit("%s", msg); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 852 | error("Exiting, you have requested strict checking."); |
| 853 | goto fail; |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 854 | } else if (options.strict_host_key_checking == 2) { |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 855 | strlcat(msg, "\nAre you sure you want " |
| 856 | "to continue connecting (yes/no)? ", sizeof(msg)); |
| 857 | if (!confirm(msg)) |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 858 | goto fail; |
Damien Miller | 49d795c | 2002-01-22 23:34:12 +1100 | [diff] [blame] | 859 | } else { |
Damien Miller | ab2db41 | 2003-06-02 19:09:13 +1000 | [diff] [blame] | 860 | logit("%s", msg); |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 861 | } |
| 862 | } |
| 863 | |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 864 | xfree(ip); |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 865 | return 0; |
| 866 | |
| 867 | fail: |
| 868 | xfree(ip); |
| 869 | return -1; |
| 870 | } |
| 871 | |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 872 | /* returns 0 if key verifies or -1 if key does NOT verify */ |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 873 | int |
| 874 | verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key) |
| 875 | { |
| 876 | struct stat st; |
| 877 | |
Damien Miller | 37876e9 | 2003-05-15 10:19:46 +1000 | [diff] [blame] | 878 | #ifdef DNS |
| 879 | if (options.verify_host_key_dns) { |
| 880 | switch(verify_host_key_dns(host, hostaddr, host_key)) { |
| 881 | case DNS_VERIFY_OK: |
| 882 | return 0; |
| 883 | case DNS_VERIFY_FAILED: |
| 884 | return -1; |
| 885 | case DNS_VERIFY_ERROR: |
| 886 | break; |
| 887 | default: |
| 888 | debug3("bad return value from verify_host_key_dns"); |
| 889 | break; |
| 890 | } |
| 891 | } |
| 892 | #endif /* DNS */ |
| 893 | |
Ben Lindstrom | d6481ea | 2001-06-25 04:37:41 +0000 | [diff] [blame] | 894 | /* return ok if the key can be found in an old keyfile */ |
| 895 | if (stat(options.system_hostfile2, &st) == 0 || |
| 896 | stat(options.user_hostfile2, &st) == 0) { |
| 897 | if (check_host_key(host, hostaddr, host_key, /*readonly*/ 1, |
| 898 | options.user_hostfile2, options.system_hostfile2) == 0) |
| 899 | return 0; |
| 900 | } |
| 901 | return check_host_key(host, hostaddr, host_key, /*readonly*/ 0, |
| 902 | options.user_hostfile, options.system_hostfile); |
Damien Miller | a34a28b | 1999-12-14 10:47:15 +1100 | [diff] [blame] | 903 | } |
Damien Miller | 037a0dc | 1999-12-07 15:38:31 +1100 | [diff] [blame] | 904 | |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 905 | /* |
| 906 | * Starts a dialog with the server, and authenticates the current user on the |
| 907 | * server. This does not need any extra privileges. The basic connection |
| 908 | * to the server must already have been established before this is called. |
| 909 | * If login fails, this function prints an error and never returns. |
| 910 | * This function does not require super-user privileges. |
| 911 | */ |
| 912 | void |
Ben Lindstrom | 1bad256 | 2002-06-06 19:57:33 +0000 | [diff] [blame] | 913 | ssh_login(Sensitive *sensitive, const char *orighost, |
Ben Lindstrom | 3fcf1a2 | 2001-04-08 18:26:59 +0000 | [diff] [blame] | 914 | struct sockaddr *hostaddr, struct passwd *pw) |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 915 | { |
| 916 | char *host, *cp; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 917 | char *server_user, *local_user; |
| 918 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 919 | local_user = xstrdup(pw->pw_name); |
| 920 | server_user = options.user ? options.user : local_user; |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 921 | |
| 922 | /* Convert the user-supplied hostname into all lowercase. */ |
| 923 | host = xstrdup(orighost); |
| 924 | for (cp = host; *cp; cp++) |
| 925 | if (isupper(*cp)) |
| 926 | *cp = tolower(*cp); |
| 927 | |
| 928 | /* Exchange protocol version identification strings with the server. */ |
| 929 | ssh_exchange_identification(); |
| 930 | |
| 931 | /* Put the connection into non-blocking mode. */ |
| 932 | packet_set_nonblocking(); |
| 933 | |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 934 | /* key exchange */ |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 935 | /* authenticate user */ |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 936 | if (compat20) { |
| 937 | ssh_kex2(host, hostaddr); |
Ben Lindstrom | 1bad256 | 2002-06-06 19:57:33 +0000 | [diff] [blame] | 938 | ssh_userauth2(local_user, server_user, host, sensitive); |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 939 | } else { |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 940 | ssh_kex(host, hostaddr); |
Ben Lindstrom | 1bad256 | 2002-06-06 19:57:33 +0000 | [diff] [blame] | 941 | ssh_userauth1(local_user, server_user, host, sensitive); |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 942 | } |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 943 | } |
Damien Miller | 79438cc | 2001-02-16 12:34:57 +1100 | [diff] [blame] | 944 | |
| 945 | void |
| 946 | ssh_put_password(char *password) |
| 947 | { |
| 948 | int size; |
| 949 | char *padded; |
| 950 | |
Ben Lindstrom | d20d0f3 | 2001-03-10 17:22:20 +0000 | [diff] [blame] | 951 | if (datafellows & SSH_BUG_PASSWORDPAD) { |
Ben Lindstrom | 664408d | 2001-06-09 01:42:01 +0000 | [diff] [blame] | 952 | packet_put_cstring(password); |
Ben Lindstrom | d20d0f3 | 2001-03-10 17:22:20 +0000 | [diff] [blame] | 953 | return; |
| 954 | } |
Damien Miller | 79438cc | 2001-02-16 12:34:57 +1100 | [diff] [blame] | 955 | size = roundup(strlen(password) + 1, 32); |
| 956 | padded = xmalloc(size); |
| 957 | memset(padded, 0, size); |
| 958 | strlcpy(padded, password, size); |
| 959 | packet_put_string(padded, size); |
| 960 | memset(padded, 0, size); |
| 961 | xfree(padded); |
| 962 | } |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 963 | |
| 964 | static int |
| 965 | show_key_from_file(const char *file, const char *host, int keytype) |
| 966 | { |
| 967 | Key *found; |
| 968 | char *fp; |
| 969 | int line, ret; |
| 970 | |
| 971 | found = key_new(keytype); |
| 972 | if ((ret = lookup_key_in_hostfile_by_type(file, host, |
| 973 | keytype, found, &line))) { |
| 974 | fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX); |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 975 | logit("WARNING: %s key found for host %s\n" |
Ben Lindstrom | 4b99be8 | 2002-08-01 01:26:29 +0000 | [diff] [blame] | 976 | "in %s:%d\n" |
Ben Lindstrom | 3ed6640 | 2002-08-01 01:21:56 +0000 | [diff] [blame] | 977 | "%s key fingerprint %s.", |
| 978 | key_type(found), host, file, line, |
| 979 | key_type(found), fp); |
| 980 | xfree(fp); |
| 981 | } |
| 982 | key_free(found); |
| 983 | return (ret); |
| 984 | } |
| 985 | |
| 986 | /* print all known host keys for a given host, but skip keys of given type */ |
| 987 | static int |
| 988 | show_other_keys(const char *host, Key *key) |
| 989 | { |
| 990 | int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1}; |
| 991 | int i, found = 0; |
| 992 | |
| 993 | for (i = 0; type[i] != -1; i++) { |
| 994 | if (type[i] == key->type) |
| 995 | continue; |
| 996 | if (type[i] != KEY_RSA1 && |
| 997 | show_key_from_file(options.user_hostfile2, host, type[i])) { |
| 998 | found = 1; |
| 999 | continue; |
| 1000 | } |
| 1001 | if (type[i] != KEY_RSA1 && |
| 1002 | show_key_from_file(options.system_hostfile2, host, type[i])) { |
| 1003 | found = 1; |
| 1004 | continue; |
| 1005 | } |
| 1006 | if (show_key_from_file(options.user_hostfile, host, type[i])) { |
| 1007 | found = 1; |
| 1008 | continue; |
| 1009 | } |
| 1010 | if (show_key_from_file(options.system_hostfile, host, type[i])) { |
| 1011 | found = 1; |
| 1012 | continue; |
| 1013 | } |
| 1014 | debug2("no key of type %d for host %s", type[i], host); |
| 1015 | } |
| 1016 | return (found); |
| 1017 | } |