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> |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 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 | * This file contains code implementing the packet protocol and communication |
| 6 | * with the other side. This same code is used both on client and server side. |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 7 | * |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 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 | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 13 | * |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 14 | * |
| 15 | * SSH2 packet format added by Markus Friedl. |
Ben Lindstrom | 4469723 | 2001-07-04 03:32:30 +0000 | [diff] [blame] | 16 | * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 17 | * |
| 18 | * Redistribution and use in source and binary forms, with or without |
| 19 | * modification, are permitted provided that the following conditions |
| 20 | * are met: |
| 21 | * 1. Redistributions of source code must retain the above copyright |
| 22 | * notice, this list of conditions and the following disclaimer. |
| 23 | * 2. Redistributions in binary form must reproduce the above copyright |
| 24 | * notice, this list of conditions and the following disclaimer in the |
| 25 | * documentation and/or other materials provided with the distribution. |
| 26 | * |
| 27 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 28 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 29 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 30 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 31 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 32 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 33 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 34 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 35 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 36 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 37 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 38 | |
| 39 | #include "includes.h" |
Ben Lindstrom | 402c6cc | 2002-06-21 00:43:42 +0000 | [diff] [blame] | 40 | RCSID("$OpenBSD: packet.c,v 1.95 2002/06/19 18:01:00 markus Exp $"); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 41 | |
| 42 | #include "xmalloc.h" |
| 43 | #include "buffer.h" |
| 44 | #include "packet.h" |
| 45 | #include "bufaux.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 46 | #include "crc32.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 47 | #include "getput.h" |
| 48 | |
| 49 | #include "compress.h" |
| 50 | #include "deattack.h" |
Ben Lindstrom | c763767 | 2001-06-09 00:36:26 +0000 | [diff] [blame] | 51 | #include "channels.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 52 | |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 53 | #include "compat.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 54 | #include "ssh1.h" |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 55 | #include "ssh2.h" |
| 56 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 57 | #include "cipher.h" |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 58 | #include "kex.h" |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 59 | #include "mac.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 60 | #include "log.h" |
| 61 | #include "canohost.h" |
Damien Miller | 4d00776 | 2002-02-05 11:52:54 +1100 | [diff] [blame] | 62 | #include "misc.h" |
Ben Lindstrom | 402c6cc | 2002-06-21 00:43:42 +0000 | [diff] [blame] | 63 | #include "ssh.h" |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 64 | |
| 65 | #ifdef PACKET_DEBUG |
| 66 | #define DBG(x) x |
| 67 | #else |
| 68 | #define DBG(x) |
| 69 | #endif |
| 70 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 71 | /* |
| 72 | * This variable contains the file descriptors used for communicating with |
| 73 | * the other side. connection_in is used for reading; connection_out for |
| 74 | * writing. These can be the same descriptor, in which case it is assumed to |
| 75 | * be a socket. |
| 76 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 77 | static int connection_in = -1; |
| 78 | static int connection_out = -1; |
| 79 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 80 | /* Protocol flags for the remote side. */ |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 81 | static u_int remote_protocol_flags = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 82 | |
| 83 | /* Encryption context for receiving data. This is only used for decryption. */ |
| 84 | static CipherContext receive_context; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 85 | |
| 86 | /* Encryption context for sending data. This is only used for encryption. */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 87 | static CipherContext send_context; |
| 88 | |
| 89 | /* Buffer for raw input data from the socket. */ |
Ben Lindstrom | f6027d3 | 2002-03-22 01:42:04 +0000 | [diff] [blame] | 90 | Buffer input; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 91 | |
| 92 | /* Buffer for raw output data going to the socket. */ |
Ben Lindstrom | f6027d3 | 2002-03-22 01:42:04 +0000 | [diff] [blame] | 93 | Buffer output; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 94 | |
| 95 | /* Buffer for the partial outgoing packet being constructed. */ |
| 96 | static Buffer outgoing_packet; |
| 97 | |
| 98 | /* Buffer for the incoming packet currently being processed. */ |
| 99 | static Buffer incoming_packet; |
| 100 | |
| 101 | /* Scratch buffer for packet compression/decompression. */ |
| 102 | static Buffer compression_buffer; |
Ben Lindstrom | fb50cdf | 2001-04-05 23:20:46 +0000 | [diff] [blame] | 103 | static int compression_buffer_ready = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 104 | |
| 105 | /* Flag indicating whether packet compression/decompression is enabled. */ |
| 106 | static int packet_compression = 0; |
| 107 | |
Damien Miller | 6162d12 | 1999-11-21 13:23:52 +1100 | [diff] [blame] | 108 | /* default maximum packet size */ |
| 109 | int max_packet_size = 32768; |
| 110 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 111 | /* Flag indicating whether this module has been initialized. */ |
| 112 | static int initialized = 0; |
| 113 | |
| 114 | /* Set to true if the connection is interactive. */ |
| 115 | static int interactive_mode = 0; |
| 116 | |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 117 | /* Session key information for Encryption and MAC */ |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 118 | Newkeys *newkeys[MODE_MAX]; |
Ben Lindstrom | f6027d3 | 2002-03-22 01:42:04 +0000 | [diff] [blame] | 119 | static u_int32_t read_seqnr = 0; |
| 120 | static u_int32_t send_seqnr = 0; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 121 | |
Ben Lindstrom | 402c6cc | 2002-06-21 00:43:42 +0000 | [diff] [blame] | 122 | /* Session key for protocol v1 */ |
| 123 | static u_char ssh1_key[SSH_SESSION_KEY_LENGTH]; |
| 124 | static u_int ssh1_keylen; |
| 125 | |
Damien Miller | 9f64390 | 2001-11-12 11:02:52 +1100 | [diff] [blame] | 126 | /* roundup current message to extra_pad bytes */ |
| 127 | static u_char extra_pad = 0; |
| 128 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 129 | /* |
| 130 | * Sets the descriptors used for communication. Disables encryption until |
| 131 | * packet_set_encryption_key is called. |
| 132 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 133 | void |
| 134 | packet_set_connection(int fd_in, int fd_out) |
| 135 | { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 136 | Cipher *none = cipher_by_name("none"); |
| 137 | if (none == NULL) |
| 138 | fatal("packet_set_connection: cannot load cipher 'none'"); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 139 | connection_in = fd_in; |
| 140 | connection_out = fd_out; |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 141 | cipher_init(&send_context, none, "", 0, NULL, 0, CIPHER_ENCRYPT); |
| 142 | cipher_init(&receive_context, none, "", 0, NULL, 0, CIPHER_DECRYPT); |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 143 | newkeys[MODE_IN] = newkeys[MODE_OUT] = NULL; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 144 | if (!initialized) { |
| 145 | initialized = 1; |
| 146 | buffer_init(&input); |
| 147 | buffer_init(&output); |
| 148 | buffer_init(&outgoing_packet); |
| 149 | buffer_init(&incoming_packet); |
| 150 | } |
| 151 | /* Kludge: arrange the close function to be called from fatal(). */ |
| 152 | fatal_add_cleanup((void (*) (void *)) packet_close, NULL); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 153 | } |
| 154 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 155 | /* Returns 1 if remote host is connected via socket, 0 if not. */ |
| 156 | |
| 157 | int |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 158 | packet_connection_is_on_socket(void) |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 159 | { |
| 160 | struct sockaddr_storage from, to; |
| 161 | socklen_t fromlen, tolen; |
| 162 | |
| 163 | /* filedescriptors in and out are the same, so it's a socket */ |
| 164 | if (connection_in == connection_out) |
| 165 | return 1; |
| 166 | fromlen = sizeof(from); |
| 167 | memset(&from, 0, sizeof(from)); |
Damien Miller | f052aaf | 2000-01-22 19:47:21 +1100 | [diff] [blame] | 168 | if (getpeername(connection_in, (struct sockaddr *)&from, &fromlen) < 0) |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 169 | return 0; |
| 170 | tolen = sizeof(to); |
| 171 | memset(&to, 0, sizeof(to)); |
Damien Miller | f052aaf | 2000-01-22 19:47:21 +1100 | [diff] [blame] | 172 | if (getpeername(connection_out, (struct sockaddr *)&to, &tolen) < 0) |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 173 | return 0; |
| 174 | if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0) |
| 175 | return 0; |
| 176 | if (from.ss_family != AF_INET && from.ss_family != AF_INET6) |
| 177 | return 0; |
| 178 | return 1; |
| 179 | } |
| 180 | |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 181 | /* |
Ben Lindstrom | f6027d3 | 2002-03-22 01:42:04 +0000 | [diff] [blame] | 182 | * Exports an IV from the CipherContext required to export the key |
| 183 | * state back from the unprivileged child to the privileged parent |
| 184 | * process. |
| 185 | */ |
| 186 | |
| 187 | void |
| 188 | packet_get_keyiv(int mode, u_char *iv, u_int len) |
| 189 | { |
| 190 | CipherContext *cc; |
| 191 | |
| 192 | if (mode == MODE_OUT) |
| 193 | cc = &send_context; |
| 194 | else |
| 195 | cc = &receive_context; |
| 196 | |
| 197 | cipher_get_keyiv(cc, iv, len); |
| 198 | } |
| 199 | |
| 200 | int |
| 201 | packet_get_keycontext(int mode, u_char *dat) |
| 202 | { |
| 203 | CipherContext *cc; |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 204 | |
Ben Lindstrom | f6027d3 | 2002-03-22 01:42:04 +0000 | [diff] [blame] | 205 | if (mode == MODE_OUT) |
| 206 | cc = &send_context; |
| 207 | else |
| 208 | cc = &receive_context; |
| 209 | |
| 210 | return (cipher_get_keycontext(cc, dat)); |
| 211 | } |
| 212 | |
| 213 | void |
| 214 | packet_set_keycontext(int mode, u_char *dat) |
| 215 | { |
| 216 | CipherContext *cc; |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 217 | |
Ben Lindstrom | f6027d3 | 2002-03-22 01:42:04 +0000 | [diff] [blame] | 218 | if (mode == MODE_OUT) |
| 219 | cc = &send_context; |
| 220 | else |
| 221 | cc = &receive_context; |
| 222 | |
| 223 | cipher_set_keycontext(cc, dat); |
| 224 | } |
| 225 | |
| 226 | int |
| 227 | packet_get_keyiv_len(int mode) |
| 228 | { |
| 229 | CipherContext *cc; |
| 230 | |
| 231 | if (mode == MODE_OUT) |
| 232 | cc = &send_context; |
| 233 | else |
| 234 | cc = &receive_context; |
| 235 | |
| 236 | return (cipher_get_keyiv_len(cc)); |
| 237 | } |
| 238 | void |
| 239 | packet_set_iv(int mode, u_char *dat) |
| 240 | { |
| 241 | CipherContext *cc; |
| 242 | |
| 243 | if (mode == MODE_OUT) |
| 244 | cc = &send_context; |
| 245 | else |
| 246 | cc = &receive_context; |
| 247 | |
| 248 | cipher_set_keyiv(cc, dat); |
| 249 | } |
| 250 | int |
| 251 | packet_get_ssh1_cipher() |
| 252 | { |
| 253 | return (cipher_get_number(receive_context.cipher)); |
| 254 | } |
| 255 | |
| 256 | |
| 257 | u_int32_t |
| 258 | packet_get_seqnr(int mode) |
| 259 | { |
| 260 | return (mode == MODE_IN ? read_seqnr : send_seqnr); |
| 261 | } |
| 262 | |
| 263 | void |
| 264 | packet_set_seqnr(int mode, u_int32_t seqnr) |
| 265 | { |
| 266 | if (mode == MODE_IN) |
| 267 | read_seqnr = seqnr; |
| 268 | else if (mode == MODE_OUT) |
| 269 | send_seqnr = seqnr; |
| 270 | else |
Ben Lindstrom | 3dca4f5 | 2002-06-06 20:59:25 +0000 | [diff] [blame] | 271 | fatal("packet_set_seqnr: bad mode %d", mode); |
Ben Lindstrom | f6027d3 | 2002-03-22 01:42:04 +0000 | [diff] [blame] | 272 | } |
| 273 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 274 | /* returns 1 if connection is via ipv4 */ |
| 275 | |
| 276 | int |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 277 | packet_connection_is_ipv4(void) |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 278 | { |
| 279 | struct sockaddr_storage to; |
Damien Miller | 6fe375d | 2000-01-23 09:38:00 +1100 | [diff] [blame] | 280 | socklen_t tolen = sizeof(to); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 281 | |
| 282 | memset(&to, 0, sizeof(to)); |
| 283 | if (getsockname(connection_out, (struct sockaddr *)&to, &tolen) < 0) |
| 284 | return 0; |
Damien Miller | aa100c5 | 2002-04-26 16:54:34 +1000 | [diff] [blame] | 285 | if (to.ss_family == AF_INET) |
| 286 | return 1; |
| 287 | #ifdef IPV4_IN_IPV6 |
| 288 | if (to.ss_family == AF_INET6 && |
| 289 | IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr)) |
| 290 | return 1; |
| 291 | #endif |
| 292 | return 0; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 293 | } |
| 294 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 295 | /* Sets the connection into non-blocking mode. */ |
| 296 | |
| 297 | void |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 298 | packet_set_nonblocking(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 299 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 300 | /* Set the socket into non-blocking mode. */ |
| 301 | if (fcntl(connection_in, F_SETFL, O_NONBLOCK) < 0) |
| 302 | error("fcntl O_NONBLOCK: %.100s", strerror(errno)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 303 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 304 | if (connection_out != connection_in) { |
| 305 | if (fcntl(connection_out, F_SETFL, O_NONBLOCK) < 0) |
| 306 | error("fcntl O_NONBLOCK: %.100s", strerror(errno)); |
| 307 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 308 | } |
| 309 | |
| 310 | /* Returns the socket used for reading. */ |
| 311 | |
| 312 | int |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 313 | packet_get_connection_in(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 314 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 315 | return connection_in; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 316 | } |
| 317 | |
| 318 | /* Returns the descriptor used for writing. */ |
| 319 | |
| 320 | int |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 321 | packet_get_connection_out(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 322 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 323 | return connection_out; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 324 | } |
| 325 | |
| 326 | /* Closes the connection and clears and frees internal data structures. */ |
| 327 | |
| 328 | void |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 329 | packet_close(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 330 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 331 | if (!initialized) |
| 332 | return; |
| 333 | initialized = 0; |
| 334 | if (connection_in == connection_out) { |
| 335 | shutdown(connection_out, SHUT_RDWR); |
| 336 | close(connection_out); |
| 337 | } else { |
| 338 | close(connection_in); |
| 339 | close(connection_out); |
| 340 | } |
| 341 | buffer_free(&input); |
| 342 | buffer_free(&output); |
| 343 | buffer_free(&outgoing_packet); |
| 344 | buffer_free(&incoming_packet); |
Ben Lindstrom | fb50cdf | 2001-04-05 23:20:46 +0000 | [diff] [blame] | 345 | if (compression_buffer_ready) { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 346 | buffer_free(&compression_buffer); |
| 347 | buffer_compress_uninit(); |
| 348 | } |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 349 | cipher_cleanup(&send_context); |
| 350 | cipher_cleanup(&receive_context); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 351 | } |
| 352 | |
| 353 | /* Sets remote side protocol flags. */ |
| 354 | |
| 355 | void |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 356 | packet_set_protocol_flags(u_int protocol_flags) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 357 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 358 | remote_protocol_flags = protocol_flags; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 359 | } |
| 360 | |
| 361 | /* Returns the remote protocol flags set earlier by the above function. */ |
| 362 | |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 363 | u_int |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 364 | packet_get_protocol_flags(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 365 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 366 | return remote_protocol_flags; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 367 | } |
| 368 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 369 | /* |
| 370 | * Starts packet compression from the next packet on in both directions. |
| 371 | * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip. |
| 372 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 373 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 374 | static void |
| 375 | packet_init_compression(void) |
Ben Lindstrom | fb50cdf | 2001-04-05 23:20:46 +0000 | [diff] [blame] | 376 | { |
| 377 | if (compression_buffer_ready == 1) |
| 378 | return; |
| 379 | compression_buffer_ready = 1; |
| 380 | buffer_init(&compression_buffer); |
| 381 | } |
| 382 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 383 | void |
| 384 | packet_start_compression(int level) |
| 385 | { |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 386 | if (packet_compression && !compat20) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 387 | fatal("Compression already enabled."); |
| 388 | packet_compression = 1; |
Ben Lindstrom | fb50cdf | 2001-04-05 23:20:46 +0000 | [diff] [blame] | 389 | packet_init_compression(); |
| 390 | buffer_compress_init_send(level); |
| 391 | buffer_compress_init_recv(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 392 | } |
| 393 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 394 | /* |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 395 | * Causes any further packets to be encrypted using the given key. The same |
| 396 | * key is used for both sending and reception. However, both directions are |
| 397 | * encrypted independently of each other. |
| 398 | */ |
Ben Lindstrom | 402c6cc | 2002-06-21 00:43:42 +0000 | [diff] [blame] | 399 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 400 | void |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 401 | packet_set_encryption_key(const u_char *key, u_int keylen, |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 402 | int number) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 403 | { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 404 | Cipher *cipher = cipher_by_number(number); |
| 405 | if (cipher == NULL) |
| 406 | fatal("packet_set_encryption_key: unknown cipher number %d", number); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 407 | if (keylen < 20) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 408 | fatal("packet_set_encryption_key: keylen too small: %d", keylen); |
Ben Lindstrom | 402c6cc | 2002-06-21 00:43:42 +0000 | [diff] [blame] | 409 | if (keylen > SSH_SESSION_KEY_LENGTH) |
| 410 | fatal("packet_set_encryption_key: keylen too big: %d", keylen); |
| 411 | memcpy(ssh1_key, key, keylen); |
| 412 | ssh1_keylen = keylen; |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 413 | cipher_init(&send_context, cipher, key, keylen, NULL, 0, CIPHER_ENCRYPT); |
| 414 | cipher_init(&receive_context, cipher, key, keylen, NULL, 0, CIPHER_DECRYPT); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 415 | } |
| 416 | |
Ben Lindstrom | 402c6cc | 2002-06-21 00:43:42 +0000 | [diff] [blame] | 417 | u_int |
| 418 | packet_get_encryption_key(u_char *key) |
| 419 | { |
| 420 | if (key == NULL) |
| 421 | return (ssh1_keylen); |
| 422 | memcpy(key, ssh1_key, ssh1_keylen); |
| 423 | return (ssh1_keylen); |
| 424 | } |
| 425 | |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 426 | /* Start constructing a packet to send. */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 427 | void |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 428 | packet_start(u_char type) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 429 | { |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 430 | u_char buf[9]; |
| 431 | int len; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 432 | |
Ben Lindstrom | 204e488 | 2001-03-05 06:47:00 +0000 | [diff] [blame] | 433 | DBG(debug("packet_start[%d]", type)); |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 434 | len = compat20 ? 6 : 9; |
| 435 | memset(buf, 0, len - 1); |
| 436 | buf[len - 1] = type; |
| 437 | buffer_clear(&outgoing_packet); |
| 438 | buffer_append(&outgoing_packet, buf, len); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 439 | } |
| 440 | |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 441 | /* Append payload. */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 442 | void |
| 443 | packet_put_char(int value) |
| 444 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 445 | char ch = value; |
| 446 | buffer_append(&outgoing_packet, &ch, 1); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 447 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 448 | void |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 449 | packet_put_int(u_int value) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 450 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 451 | buffer_put_int(&outgoing_packet, value); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 452 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 453 | void |
Damien Miller | 5a6b4fe | 2001-12-21 14:56:54 +1100 | [diff] [blame] | 454 | packet_put_string(const void *buf, u_int len) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 455 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 456 | buffer_put_string(&outgoing_packet, buf, len); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 457 | } |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 458 | void |
| 459 | packet_put_cstring(const char *str) |
| 460 | { |
Ben Lindstrom | 664408d | 2001-06-09 01:42:01 +0000 | [diff] [blame] | 461 | buffer_put_cstring(&outgoing_packet, str); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 462 | } |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 463 | void |
Damien Miller | 5a6b4fe | 2001-12-21 14:56:54 +1100 | [diff] [blame] | 464 | packet_put_raw(const void *buf, u_int len) |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 465 | { |
| 466 | buffer_append(&outgoing_packet, buf, len); |
| 467 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 468 | void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 469 | packet_put_bignum(BIGNUM * value) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 470 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 471 | buffer_put_bignum(&outgoing_packet, value); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 472 | } |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 473 | void |
| 474 | packet_put_bignum2(BIGNUM * value) |
| 475 | { |
| 476 | buffer_put_bignum2(&outgoing_packet, value); |
| 477 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 478 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 479 | /* |
| 480 | * Finalizes and sends the packet. If the encryption key has been set, |
| 481 | * encrypts the packet before sending. |
| 482 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 483 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 484 | static void |
Ben Lindstrom | 31ca54a | 2001-02-09 02:11:24 +0000 | [diff] [blame] | 485 | packet_send1(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 486 | { |
Ben Lindstrom | 4a7714a | 2002-02-26 18:04:38 +0000 | [diff] [blame] | 487 | u_char buf[8], *cp; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 488 | int i, padding, len; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 489 | u_int checksum; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 490 | u_int32_t rand = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 491 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 492 | /* |
| 493 | * If using packet compression, compress the payload of the outgoing |
| 494 | * packet. |
| 495 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 496 | if (packet_compression) { |
| 497 | buffer_clear(&compression_buffer); |
| 498 | /* Skip padding. */ |
| 499 | buffer_consume(&outgoing_packet, 8); |
| 500 | /* padding */ |
| 501 | buffer_append(&compression_buffer, "\0\0\0\0\0\0\0\0", 8); |
| 502 | buffer_compress(&outgoing_packet, &compression_buffer); |
| 503 | buffer_clear(&outgoing_packet); |
| 504 | buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 505 | buffer_len(&compression_buffer)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 506 | } |
| 507 | /* Compute packet length without padding (add checksum, remove padding). */ |
| 508 | len = buffer_len(&outgoing_packet) + 4 - 8; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 509 | |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 510 | /* Insert padding. Initialized to zero in packet_start1() */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 511 | padding = 8 - len % 8; |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 512 | if (!send_context.plaintext) { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 513 | cp = buffer_ptr(&outgoing_packet); |
| 514 | for (i = 0; i < padding; i++) { |
| 515 | if (i % 4 == 0) |
| 516 | rand = arc4random(); |
| 517 | cp[7 - i] = rand & 0xff; |
| 518 | rand >>= 8; |
| 519 | } |
| 520 | } |
| 521 | buffer_consume(&outgoing_packet, 8 - padding); |
| 522 | |
| 523 | /* Add check bytes. */ |
Damien Miller | 708d21c | 2002-01-22 23:18:15 +1100 | [diff] [blame] | 524 | checksum = ssh_crc32(buffer_ptr(&outgoing_packet), |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 525 | buffer_len(&outgoing_packet)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 526 | PUT_32BIT(buf, checksum); |
| 527 | buffer_append(&outgoing_packet, buf, 4); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 528 | |
| 529 | #ifdef PACKET_DEBUG |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 530 | fprintf(stderr, "packet_send plain: "); |
| 531 | buffer_dump(&outgoing_packet); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 532 | #endif |
| 533 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 534 | /* Append to output. */ |
| 535 | PUT_32BIT(buf, len); |
| 536 | buffer_append(&output, buf, 4); |
Damien Miller | 5a6b4fe | 2001-12-21 14:56:54 +1100 | [diff] [blame] | 537 | cp = buffer_append_space(&output, buffer_len(&outgoing_packet)); |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 538 | cipher_crypt(&send_context, cp, buffer_ptr(&outgoing_packet), |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 539 | buffer_len(&outgoing_packet)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 540 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 541 | #ifdef PACKET_DEBUG |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 542 | fprintf(stderr, "encrypted: "); |
| 543 | buffer_dump(&output); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 544 | #endif |
| 545 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 546 | buffer_clear(&outgoing_packet); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 547 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 548 | /* |
| 549 | * Note that the packet is now only buffered in output. It won\'t be |
| 550 | * actually sent until packet_write_wait or packet_write_poll is |
| 551 | * called. |
| 552 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 553 | } |
| 554 | |
Ben Lindstrom | f6027d3 | 2002-03-22 01:42:04 +0000 | [diff] [blame] | 555 | void |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 556 | set_newkeys(int mode) |
| 557 | { |
| 558 | Enc *enc; |
| 559 | Mac *mac; |
| 560 | Comp *comp; |
| 561 | CipherContext *cc; |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 562 | int encrypt; |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 563 | |
| 564 | debug("newkeys: mode %d", mode); |
| 565 | |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 566 | if (mode == MODE_OUT) { |
| 567 | cc = &send_context; |
| 568 | encrypt = CIPHER_ENCRYPT; |
| 569 | } else { |
| 570 | cc = &receive_context; |
| 571 | encrypt = CIPHER_DECRYPT; |
| 572 | } |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 573 | if (newkeys[mode] != NULL) { |
| 574 | debug("newkeys: rekeying"); |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 575 | cipher_cleanup(cc); |
Ben Lindstrom | 5ba23b3 | 2001-04-05 02:05:21 +0000 | [diff] [blame] | 576 | enc = &newkeys[mode]->enc; |
| 577 | mac = &newkeys[mode]->mac; |
| 578 | comp = &newkeys[mode]->comp; |
Ben Lindstrom | a370005 | 2001-04-05 23:26:32 +0000 | [diff] [blame] | 579 | memset(mac->key, 0, mac->key_len); |
Ben Lindstrom | 5ba23b3 | 2001-04-05 02:05:21 +0000 | [diff] [blame] | 580 | xfree(enc->name); |
| 581 | xfree(enc->iv); |
| 582 | xfree(enc->key); |
| 583 | xfree(mac->name); |
| 584 | xfree(mac->key); |
| 585 | xfree(comp->name); |
Ben Lindstrom | 238abf6 | 2001-04-04 17:52:53 +0000 | [diff] [blame] | 586 | xfree(newkeys[mode]); |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 587 | } |
| 588 | newkeys[mode] = kex_get_newkeys(mode); |
| 589 | if (newkeys[mode] == NULL) |
| 590 | fatal("newkeys: no keys for mode %d", mode); |
| 591 | enc = &newkeys[mode]->enc; |
| 592 | mac = &newkeys[mode]->mac; |
| 593 | comp = &newkeys[mode]->comp; |
| 594 | if (mac->md != NULL) |
| 595 | mac->enabled = 1; |
| 596 | DBG(debug("cipher_init_context: %d", mode)); |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 597 | cipher_init(cc, enc->cipher, enc->key, enc->key_len, |
| 598 | enc->iv, enc->block_size, encrypt); |
Ben Lindstrom | f6027d3 | 2002-03-22 01:42:04 +0000 | [diff] [blame] | 599 | /* Deleting the keys does not gain extra security */ |
| 600 | /* memset(enc->iv, 0, enc->block_size); |
| 601 | memset(enc->key, 0, enc->key_len); */ |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 602 | if (comp->type != 0 && comp->enabled == 0) { |
Ben Lindstrom | fb50cdf | 2001-04-05 23:20:46 +0000 | [diff] [blame] | 603 | packet_init_compression(); |
| 604 | if (mode == MODE_OUT) |
| 605 | buffer_compress_init_send(6); |
| 606 | else |
| 607 | buffer_compress_init_recv(); |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 608 | comp->enabled = 1; |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 609 | } |
| 610 | } |
| 611 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 612 | /* |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 613 | * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) |
| 614 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 615 | static void |
Ben Lindstrom | 31ca54a | 2001-02-09 02:11:24 +0000 | [diff] [blame] | 616 | packet_send2(void) |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 617 | { |
Ben Lindstrom | 4a7714a | 2002-02-26 18:04:38 +0000 | [diff] [blame] | 618 | u_char type, *cp, *macbuf = NULL; |
Damien Miller | 9f64390 | 2001-11-12 11:02:52 +1100 | [diff] [blame] | 619 | u_char padlen, pad; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 620 | u_int packet_length = 0; |
Damien Miller | 9f64390 | 2001-11-12 11:02:52 +1100 | [diff] [blame] | 621 | u_int i, len; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 622 | u_int32_t rand = 0; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 623 | Enc *enc = NULL; |
| 624 | Mac *mac = NULL; |
| 625 | Comp *comp = NULL; |
| 626 | int block_size; |
| 627 | |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 628 | if (newkeys[MODE_OUT] != NULL) { |
| 629 | enc = &newkeys[MODE_OUT]->enc; |
| 630 | mac = &newkeys[MODE_OUT]->mac; |
| 631 | comp = &newkeys[MODE_OUT]->comp; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 632 | } |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 633 | block_size = enc ? enc->block_size : 8; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 634 | |
Ben Lindstrom | 4a7714a | 2002-02-26 18:04:38 +0000 | [diff] [blame] | 635 | cp = buffer_ptr(&outgoing_packet); |
| 636 | type = cp[5]; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 637 | |
| 638 | #ifdef PACKET_DEBUG |
| 639 | fprintf(stderr, "plain: "); |
| 640 | buffer_dump(&outgoing_packet); |
| 641 | #endif |
| 642 | |
| 643 | if (comp && comp->enabled) { |
| 644 | len = buffer_len(&outgoing_packet); |
| 645 | /* skip header, compress only payload */ |
| 646 | buffer_consume(&outgoing_packet, 5); |
| 647 | buffer_clear(&compression_buffer); |
| 648 | buffer_compress(&outgoing_packet, &compression_buffer); |
| 649 | buffer_clear(&outgoing_packet); |
| 650 | buffer_append(&outgoing_packet, "\0\0\0\0\0", 5); |
| 651 | buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), |
| 652 | buffer_len(&compression_buffer)); |
| 653 | DBG(debug("compression: raw %d compressed %d", len, |
| 654 | buffer_len(&outgoing_packet))); |
| 655 | } |
| 656 | |
| 657 | /* sizeof (packet_len + pad_len + payload) */ |
| 658 | len = buffer_len(&outgoing_packet); |
| 659 | |
| 660 | /* |
| 661 | * calc size of padding, alloc space, get random data, |
| 662 | * minimum padding is 4 bytes |
| 663 | */ |
| 664 | padlen = block_size - (len % block_size); |
| 665 | if (padlen < 4) |
| 666 | padlen += block_size; |
Damien Miller | 9f64390 | 2001-11-12 11:02:52 +1100 | [diff] [blame] | 667 | if (extra_pad) { |
| 668 | /* will wrap if extra_pad+padlen > 255 */ |
| 669 | extra_pad = roundup(extra_pad, block_size); |
| 670 | pad = extra_pad - ((len + padlen) % extra_pad); |
Ben Lindstrom | 8b08d81 | 2002-03-26 02:09:41 +0000 | [diff] [blame] | 671 | debug3("packet_send2: adding %d (len %d padlen %d extra_pad %d)", |
Damien Miller | 9f64390 | 2001-11-12 11:02:52 +1100 | [diff] [blame] | 672 | pad, len, padlen, extra_pad); |
| 673 | padlen += pad; |
| 674 | extra_pad = 0; |
| 675 | } |
Damien Miller | 5a6b4fe | 2001-12-21 14:56:54 +1100 | [diff] [blame] | 676 | cp = buffer_append_space(&outgoing_packet, padlen); |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 677 | if (enc && !send_context.plaintext) { |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 678 | /* random padding */ |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 679 | for (i = 0; i < padlen; i++) { |
| 680 | if (i % 4 == 0) |
| 681 | rand = arc4random(); |
| 682 | cp[i] = rand & 0xff; |
Ben Lindstrom | 6a5cde0 | 2001-03-05 06:07:00 +0000 | [diff] [blame] | 683 | rand >>= 8; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 684 | } |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 685 | } else { |
| 686 | /* clear padding */ |
| 687 | memset(cp, 0, padlen); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 688 | } |
| 689 | /* packet_length includes payload, padding and padding length field */ |
| 690 | packet_length = buffer_len(&outgoing_packet) - 4; |
Ben Lindstrom | 4a7714a | 2002-02-26 18:04:38 +0000 | [diff] [blame] | 691 | cp = buffer_ptr(&outgoing_packet); |
| 692 | PUT_32BIT(cp, packet_length); |
| 693 | cp[4] = padlen; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 694 | DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen)); |
| 695 | |
| 696 | /* compute MAC over seqnr and packet(length fields, payload, padding) */ |
| 697 | if (mac && mac->enabled) { |
Ben Lindstrom | f6027d3 | 2002-03-22 01:42:04 +0000 | [diff] [blame] | 698 | macbuf = mac_compute(mac, send_seqnr, |
Damien Miller | 708d21c | 2002-01-22 23:18:15 +1100 | [diff] [blame] | 699 | buffer_ptr(&outgoing_packet), |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 700 | buffer_len(&outgoing_packet)); |
Ben Lindstrom | f6027d3 | 2002-03-22 01:42:04 +0000 | [diff] [blame] | 701 | DBG(debug("done calc MAC out #%d", send_seqnr)); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 702 | } |
| 703 | /* encrypt packet and append to output buffer. */ |
Damien Miller | 5a6b4fe | 2001-12-21 14:56:54 +1100 | [diff] [blame] | 704 | cp = buffer_append_space(&output, buffer_len(&outgoing_packet)); |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 705 | cipher_crypt(&send_context, cp, buffer_ptr(&outgoing_packet), |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 706 | buffer_len(&outgoing_packet)); |
| 707 | /* append unencrypted MAC */ |
| 708 | if (mac && mac->enabled) |
| 709 | buffer_append(&output, (char *)macbuf, mac->mac_len); |
| 710 | #ifdef PACKET_DEBUG |
| 711 | fprintf(stderr, "encrypted: "); |
| 712 | buffer_dump(&output); |
| 713 | #endif |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 714 | /* increment sequence number for outgoing packets */ |
Ben Lindstrom | f6027d3 | 2002-03-22 01:42:04 +0000 | [diff] [blame] | 715 | if (++send_seqnr == 0) |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 716 | log("outgoing seqnr wraps around"); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 717 | buffer_clear(&outgoing_packet); |
| 718 | |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 719 | if (type == SSH2_MSG_NEWKEYS) |
| 720 | set_newkeys(MODE_OUT); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 721 | } |
| 722 | |
| 723 | void |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 724 | packet_send(void) |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 725 | { |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 726 | if (compat20) |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 727 | packet_send2(); |
| 728 | else |
| 729 | packet_send1(); |
| 730 | DBG(debug("packet_send done")); |
| 731 | } |
| 732 | |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 733 | /* |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 734 | * Waits until a packet has been received, and returns its type. Note that |
| 735 | * no other data is processed until this returns, so this function should not |
| 736 | * be used during the interactive session. |
| 737 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 738 | |
| 739 | int |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 740 | packet_read_seqnr(u_int32_t *seqnr_p) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 741 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 742 | int type, len; |
Ben Lindstrom | cb978aa | 2001-03-05 07:07:49 +0000 | [diff] [blame] | 743 | fd_set *setp; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 744 | char buf[8192]; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 745 | DBG(debug("packet_read()")); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 746 | |
Ben Lindstrom | cb978aa | 2001-03-05 07:07:49 +0000 | [diff] [blame] | 747 | setp = (fd_set *)xmalloc(howmany(connection_in+1, NFDBITS) * |
| 748 | sizeof(fd_mask)); |
| 749 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 750 | /* Since we are blocking, ensure that all written packets have been sent. */ |
| 751 | packet_write_wait(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 752 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 753 | /* Stay in the loop until we have received a complete packet. */ |
| 754 | for (;;) { |
| 755 | /* Try to read a packet from the buffer. */ |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 756 | type = packet_read_poll_seqnr(seqnr_p); |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 757 | if (!compat20 && ( |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 758 | type == SSH_SMSG_SUCCESS |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 759 | || type == SSH_SMSG_FAILURE |
| 760 | || type == SSH_CMSG_EOF |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 761 | || type == SSH_CMSG_EXIT_CONFIRMATION)) |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 762 | packet_check_eom(); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 763 | /* If we got a packet, return it. */ |
Ben Lindstrom | cb978aa | 2001-03-05 07:07:49 +0000 | [diff] [blame] | 764 | if (type != SSH_MSG_NONE) { |
| 765 | xfree(setp); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 766 | return type; |
Ben Lindstrom | cb978aa | 2001-03-05 07:07:49 +0000 | [diff] [blame] | 767 | } |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 768 | /* |
| 769 | * Otherwise, wait for some data to arrive, add it to the |
| 770 | * buffer, and try again. |
| 771 | */ |
Ben Lindstrom | cb978aa | 2001-03-05 07:07:49 +0000 | [diff] [blame] | 772 | memset(setp, 0, howmany(connection_in + 1, NFDBITS) * |
| 773 | sizeof(fd_mask)); |
| 774 | FD_SET(connection_in, setp); |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 775 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 776 | /* Wait for some data to arrive. */ |
Ben Lindstrom | cb978aa | 2001-03-05 07:07:49 +0000 | [diff] [blame] | 777 | while (select(connection_in + 1, setp, NULL, NULL, NULL) == -1 && |
Ben Lindstrom | f945251 | 2001-02-15 03:12:08 +0000 | [diff] [blame] | 778 | (errno == EAGAIN || errno == EINTR)) |
| 779 | ; |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 780 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 781 | /* Read data from the socket. */ |
| 782 | len = read(connection_in, buf, sizeof(buf)); |
Damien Miller | 5e7c10e | 1999-12-16 13:18:04 +1100 | [diff] [blame] | 783 | if (len == 0) { |
| 784 | log("Connection closed by %.200s", get_remote_ipaddr()); |
| 785 | fatal_cleanup(); |
| 786 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 787 | if (len < 0) |
| 788 | fatal("Read from socket failed: %.100s", strerror(errno)); |
| 789 | /* Append it to the buffer. */ |
| 790 | packet_process_incoming(buf, len); |
| 791 | } |
| 792 | /* NOTREACHED */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 793 | } |
| 794 | |
Damien Miller | 278f907 | 2001-12-21 15:00:19 +1100 | [diff] [blame] | 795 | int |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 796 | packet_read(void) |
Damien Miller | 278f907 | 2001-12-21 15:00:19 +1100 | [diff] [blame] | 797 | { |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 798 | return packet_read_seqnr(NULL); |
Damien Miller | 278f907 | 2001-12-21 15:00:19 +1100 | [diff] [blame] | 799 | } |
| 800 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 801 | /* |
| 802 | * Waits until a packet has been received, verifies that its type matches |
| 803 | * that given, and gives a fatal error and exits if there is a mismatch. |
| 804 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 805 | |
| 806 | void |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 807 | packet_read_expect(int expected_type) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 808 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 809 | int type; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 810 | |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 811 | type = packet_read(); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 812 | if (type != expected_type) |
| 813 | packet_disconnect("Protocol error: expected packet type %d, got %d", |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 814 | expected_type, type); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 815 | } |
| 816 | |
| 817 | /* Checks if a full packet is available in the data received so far via |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 818 | * packet_process_incoming. If so, reads the packet; otherwise returns |
| 819 | * SSH_MSG_NONE. This does not wait for data from the connection. |
| 820 | * |
| 821 | * SSH_MSG_DISCONNECT is handled specially here. Also, |
| 822 | * SSH_MSG_IGNORE messages are skipped by this function and are never returned |
| 823 | * to higher levels. |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 824 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 825 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 826 | static int |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 827 | packet_read_poll1(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 828 | { |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 829 | u_int len, padded_len; |
Ben Lindstrom | 4a7714a | 2002-02-26 18:04:38 +0000 | [diff] [blame] | 830 | u_char *cp, type; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 831 | u_int checksum, stored_checksum; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 832 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 833 | /* Check if input size is less than minimum packet size. */ |
| 834 | if (buffer_len(&input) < 4 + 8) |
| 835 | return SSH_MSG_NONE; |
| 836 | /* Get length of incoming packet. */ |
Ben Lindstrom | 4a7714a | 2002-02-26 18:04:38 +0000 | [diff] [blame] | 837 | cp = buffer_ptr(&input); |
| 838 | len = GET_32BIT(cp); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 839 | if (len < 1 + 2 + 2 || len > 256 * 1024) |
| 840 | packet_disconnect("Bad packet length %d.", len); |
| 841 | padded_len = (len + 8) & ~7; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 842 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 843 | /* Check if the packet has been entirely received. */ |
| 844 | if (buffer_len(&input) < 4 + padded_len) |
| 845 | return SSH_MSG_NONE; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 846 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 847 | /* The entire packet is in buffer. */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 848 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 849 | /* Consume packet length. */ |
| 850 | buffer_consume(&input, 4); |
| 851 | |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 852 | /* |
| 853 | * Cryptographic attack detector for ssh |
| 854 | * (C)1998 CORE-SDI, Buenos Aires Argentina |
| 855 | * Ariel Futoransky(futo@core-sdi.com) |
| 856 | */ |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 857 | if (!receive_context.plaintext && |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 858 | detect_attack(buffer_ptr(&input), padded_len, NULL) == DEATTACK_DETECTED) |
| 859 | packet_disconnect("crc32 compensation attack: network attack detected"); |
| 860 | |
| 861 | /* Decrypt data to incoming_packet. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 862 | buffer_clear(&incoming_packet); |
Damien Miller | 5a6b4fe | 2001-12-21 14:56:54 +1100 | [diff] [blame] | 863 | cp = buffer_append_space(&incoming_packet, padded_len); |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 864 | cipher_crypt(&receive_context, cp, buffer_ptr(&input), padded_len); |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 865 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 866 | buffer_consume(&input, padded_len); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 867 | |
| 868 | #ifdef PACKET_DEBUG |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 869 | fprintf(stderr, "read_poll plain: "); |
| 870 | buffer_dump(&incoming_packet); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 871 | #endif |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 872 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 873 | /* Compute packet checksum. */ |
Damien Miller | 708d21c | 2002-01-22 23:18:15 +1100 | [diff] [blame] | 874 | checksum = ssh_crc32(buffer_ptr(&incoming_packet), |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 875 | buffer_len(&incoming_packet) - 4); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 876 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 877 | /* Skip padding. */ |
| 878 | buffer_consume(&incoming_packet, 8 - len % 8); |
Damien Miller | fd7c911 | 1999-11-08 16:15:55 +1100 | [diff] [blame] | 879 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 880 | /* Test check bytes. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 881 | if (len != buffer_len(&incoming_packet)) |
Damien Miller | 278f907 | 2001-12-21 15:00:19 +1100 | [diff] [blame] | 882 | packet_disconnect("packet_read_poll1: len %d != buffer_len %d.", |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 883 | len, buffer_len(&incoming_packet)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 884 | |
Ben Lindstrom | 4a7714a | 2002-02-26 18:04:38 +0000 | [diff] [blame] | 885 | cp = (u_char *)buffer_ptr(&incoming_packet) + len - 4; |
| 886 | stored_checksum = GET_32BIT(cp); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 887 | if (checksum != stored_checksum) |
| 888 | packet_disconnect("Corrupted check bytes on input."); |
| 889 | buffer_consume_end(&incoming_packet, 4); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 890 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 891 | if (packet_compression) { |
| 892 | buffer_clear(&compression_buffer); |
| 893 | buffer_uncompress(&incoming_packet, &compression_buffer); |
| 894 | buffer_clear(&incoming_packet); |
| 895 | buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 896 | buffer_len(&compression_buffer)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 897 | } |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 898 | type = buffer_get_char(&incoming_packet); |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 899 | return type; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 900 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 901 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 902 | static int |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 903 | packet_read_poll2(u_int32_t *seqnr_p) |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 904 | { |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 905 | static u_int packet_length = 0; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 906 | u_int padlen, need; |
Ben Lindstrom | 4a7714a | 2002-02-26 18:04:38 +0000 | [diff] [blame] | 907 | u_char *macbuf, *cp, type; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 908 | int maclen, block_size; |
| 909 | Enc *enc = NULL; |
| 910 | Mac *mac = NULL; |
| 911 | Comp *comp = NULL; |
| 912 | |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 913 | if (newkeys[MODE_IN] != NULL) { |
| 914 | enc = &newkeys[MODE_IN]->enc; |
| 915 | mac = &newkeys[MODE_IN]->mac; |
| 916 | comp = &newkeys[MODE_IN]->comp; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 917 | } |
| 918 | maclen = mac && mac->enabled ? mac->mac_len : 0; |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 919 | block_size = enc ? enc->block_size : 8; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 920 | |
| 921 | if (packet_length == 0) { |
| 922 | /* |
| 923 | * check if input size is less than the cipher block size, |
| 924 | * decrypt first block and extract length of incoming packet |
| 925 | */ |
| 926 | if (buffer_len(&input) < block_size) |
| 927 | return SSH_MSG_NONE; |
| 928 | buffer_clear(&incoming_packet); |
Damien Miller | 5a6b4fe | 2001-12-21 14:56:54 +1100 | [diff] [blame] | 929 | cp = buffer_append_space(&incoming_packet, block_size); |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 930 | cipher_crypt(&receive_context, cp, buffer_ptr(&input), |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 931 | block_size); |
Ben Lindstrom | 4a7714a | 2002-02-26 18:04:38 +0000 | [diff] [blame] | 932 | cp = buffer_ptr(&incoming_packet); |
| 933 | packet_length = GET_32BIT(cp); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 934 | if (packet_length < 1 + 4 || packet_length > 256 * 1024) { |
| 935 | buffer_dump(&incoming_packet); |
| 936 | packet_disconnect("Bad packet length %d.", packet_length); |
| 937 | } |
| 938 | DBG(debug("input: packet len %d", packet_length+4)); |
| 939 | buffer_consume(&input, block_size); |
| 940 | } |
| 941 | /* we have a partial packet of block_size bytes */ |
| 942 | need = 4 + packet_length - block_size; |
| 943 | DBG(debug("partial packet %d, need %d, maclen %d", block_size, |
| 944 | need, maclen)); |
| 945 | if (need % block_size != 0) |
| 946 | fatal("padding error: need %d block %d mod %d", |
| 947 | need, block_size, need % block_size); |
| 948 | /* |
| 949 | * check if the entire packet has been received and |
| 950 | * decrypt into incoming_packet |
| 951 | */ |
| 952 | if (buffer_len(&input) < need + maclen) |
| 953 | return SSH_MSG_NONE; |
| 954 | #ifdef PACKET_DEBUG |
| 955 | fprintf(stderr, "read_poll enc/full: "); |
| 956 | buffer_dump(&input); |
| 957 | #endif |
Damien Miller | 5a6b4fe | 2001-12-21 14:56:54 +1100 | [diff] [blame] | 958 | cp = buffer_append_space(&incoming_packet, need); |
Damien Miller | 963f6b2 | 2002-02-19 15:21:23 +1100 | [diff] [blame] | 959 | cipher_crypt(&receive_context, cp, buffer_ptr(&input), need); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 960 | buffer_consume(&input, need); |
| 961 | /* |
| 962 | * compute MAC over seqnr and packet, |
| 963 | * increment sequence number for incoming packet |
| 964 | */ |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 965 | if (mac && mac->enabled) { |
Ben Lindstrom | f6027d3 | 2002-03-22 01:42:04 +0000 | [diff] [blame] | 966 | macbuf = mac_compute(mac, read_seqnr, |
Damien Miller | 708d21c | 2002-01-22 23:18:15 +1100 | [diff] [blame] | 967 | buffer_ptr(&incoming_packet), |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 968 | buffer_len(&incoming_packet)); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 969 | if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 970 | packet_disconnect("Corrupted MAC on input."); |
Ben Lindstrom | f6027d3 | 2002-03-22 01:42:04 +0000 | [diff] [blame] | 971 | DBG(debug("MAC #%d ok", read_seqnr)); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 972 | buffer_consume(&input, mac->mac_len); |
| 973 | } |
Damien Miller | 278f907 | 2001-12-21 15:00:19 +1100 | [diff] [blame] | 974 | if (seqnr_p != NULL) |
Ben Lindstrom | f6027d3 | 2002-03-22 01:42:04 +0000 | [diff] [blame] | 975 | *seqnr_p = read_seqnr; |
| 976 | if (++read_seqnr == 0) |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 977 | log("incoming seqnr wraps around"); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 978 | |
| 979 | /* get padlen */ |
Damien Miller | 5a6b4fe | 2001-12-21 14:56:54 +1100 | [diff] [blame] | 980 | cp = buffer_ptr(&incoming_packet); |
Ben Lindstrom | 4a7714a | 2002-02-26 18:04:38 +0000 | [diff] [blame] | 981 | padlen = cp[4]; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 982 | DBG(debug("input: padlen %d", padlen)); |
| 983 | if (padlen < 4) |
| 984 | packet_disconnect("Corrupted padlen %d on input.", padlen); |
| 985 | |
| 986 | /* skip packet size + padlen, discard padding */ |
| 987 | buffer_consume(&incoming_packet, 4 + 1); |
| 988 | buffer_consume_end(&incoming_packet, padlen); |
| 989 | |
| 990 | DBG(debug("input: len before de-compress %d", buffer_len(&incoming_packet))); |
| 991 | if (comp && comp->enabled) { |
| 992 | buffer_clear(&compression_buffer); |
| 993 | buffer_uncompress(&incoming_packet, &compression_buffer); |
| 994 | buffer_clear(&incoming_packet); |
| 995 | buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), |
| 996 | buffer_len(&compression_buffer)); |
| 997 | DBG(debug("input: len after de-compress %d", buffer_len(&incoming_packet))); |
| 998 | } |
| 999 | /* |
| 1000 | * get packet type, implies consume. |
| 1001 | * return length of payload (without type field) |
| 1002 | */ |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 1003 | type = buffer_get_char(&incoming_packet); |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 1004 | if (type == SSH2_MSG_NEWKEYS) |
| 1005 | set_newkeys(MODE_IN); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1006 | #ifdef PACKET_DEBUG |
Ben Lindstrom | 204e488 | 2001-03-05 06:47:00 +0000 | [diff] [blame] | 1007 | fprintf(stderr, "read/plain[%d]:\r\n", type); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1008 | buffer_dump(&incoming_packet); |
| 1009 | #endif |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 1010 | /* reset for next packet */ |
| 1011 | packet_length = 0; |
| 1012 | return type; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1013 | } |
| 1014 | |
| 1015 | int |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 1016 | packet_read_poll_seqnr(u_int32_t *seqnr_p) |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1017 | { |
Damien Miller | 659811f | 2002-01-22 23:23:11 +1100 | [diff] [blame] | 1018 | int reason, seqnr; |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 1019 | u_char type; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1020 | char *msg; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1021 | |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 1022 | for (;;) { |
| 1023 | if (compat20) { |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 1024 | type = packet_read_poll2(seqnr_p); |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 1025 | if (type) |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1026 | DBG(debug("received packet type %d", type)); |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 1027 | switch (type) { |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1028 | case SSH2_MSG_IGNORE: |
| 1029 | break; |
| 1030 | case SSH2_MSG_DEBUG: |
| 1031 | packet_get_char(); |
| 1032 | msg = packet_get_string(NULL); |
| 1033 | debug("Remote: %.900s", msg); |
| 1034 | xfree(msg); |
| 1035 | msg = packet_get_string(NULL); |
| 1036 | xfree(msg); |
| 1037 | break; |
| 1038 | case SSH2_MSG_DISCONNECT: |
| 1039 | reason = packet_get_int(); |
| 1040 | msg = packet_get_string(NULL); |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 1041 | log("Received disconnect from %s: %d: %.400s", get_remote_ipaddr(), |
| 1042 | reason, msg); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1043 | xfree(msg); |
| 1044 | fatal_cleanup(); |
| 1045 | break; |
Damien Miller | 659811f | 2002-01-22 23:23:11 +1100 | [diff] [blame] | 1046 | case SSH2_MSG_UNIMPLEMENTED: |
| 1047 | seqnr = packet_get_int(); |
| 1048 | debug("Received SSH2_MSG_UNIMPLEMENTED for %d", seqnr); |
| 1049 | break; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1050 | default: |
| 1051 | return type; |
| 1052 | break; |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 1053 | } |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1054 | } else { |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 1055 | type = packet_read_poll1(); |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 1056 | switch (type) { |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1057 | case SSH_MSG_IGNORE: |
| 1058 | break; |
| 1059 | case SSH_MSG_DEBUG: |
| 1060 | msg = packet_get_string(NULL); |
| 1061 | debug("Remote: %.900s", msg); |
| 1062 | xfree(msg); |
| 1063 | break; |
| 1064 | case SSH_MSG_DISCONNECT: |
| 1065 | msg = packet_get_string(NULL); |
Ben Lindstrom | 5c1fbab | 2001-01-03 03:51:15 +0000 | [diff] [blame] | 1066 | log("Received disconnect from %s: %.400s", get_remote_ipaddr(), |
| 1067 | msg); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1068 | fatal_cleanup(); |
| 1069 | xfree(msg); |
| 1070 | break; |
| 1071 | default: |
Ben Lindstrom | 80c6d77 | 2001-06-05 21:09:18 +0000 | [diff] [blame] | 1072 | if (type) |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1073 | DBG(debug("received packet type %d", type)); |
| 1074 | return type; |
| 1075 | break; |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 1076 | } |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1077 | } |
| 1078 | } |
| 1079 | } |
| 1080 | |
Damien Miller | 278f907 | 2001-12-21 15:00:19 +1100 | [diff] [blame] | 1081 | int |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 1082 | packet_read_poll(void) |
Damien Miller | 278f907 | 2001-12-21 15:00:19 +1100 | [diff] [blame] | 1083 | { |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 1084 | return packet_read_poll_seqnr(NULL); |
Damien Miller | 278f907 | 2001-12-21 15:00:19 +1100 | [diff] [blame] | 1085 | } |
| 1086 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1087 | /* |
| 1088 | * Buffers the given amount of input characters. This is intended to be used |
| 1089 | * together with packet_read_poll. |
| 1090 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1091 | |
| 1092 | void |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1093 | packet_process_incoming(const char *buf, u_int len) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1094 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1095 | buffer_append(&input, buf, len); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1096 | } |
| 1097 | |
| 1098 | /* Returns a character from the packet. */ |
| 1099 | |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1100 | u_int |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 1101 | packet_get_char(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1102 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1103 | char ch; |
| 1104 | buffer_get(&incoming_packet, &ch, 1); |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1105 | return (u_char) ch; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1106 | } |
| 1107 | |
| 1108 | /* Returns an integer from the packet data. */ |
| 1109 | |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1110 | u_int |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 1111 | packet_get_int(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1112 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1113 | return buffer_get_int(&incoming_packet); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1114 | } |
| 1115 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1116 | /* |
| 1117 | * Returns an arbitrary precision integer from the packet data. The integer |
| 1118 | * must have been initialized before this call. |
| 1119 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1120 | |
| 1121 | void |
Damien Miller | d432ccf | 2002-01-22 23:14:44 +1100 | [diff] [blame] | 1122 | packet_get_bignum(BIGNUM * value) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1123 | { |
Damien Miller | 76e1e36 | 2002-01-22 23:15:57 +1100 | [diff] [blame] | 1124 | buffer_get_bignum(&incoming_packet, value); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1125 | } |
| 1126 | |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1127 | void |
Damien Miller | d432ccf | 2002-01-22 23:14:44 +1100 | [diff] [blame] | 1128 | packet_get_bignum2(BIGNUM * value) |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1129 | { |
Damien Miller | 76e1e36 | 2002-01-22 23:15:57 +1100 | [diff] [blame] | 1130 | buffer_get_bignum2(&incoming_packet, value); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1131 | } |
| 1132 | |
Damien Miller | 5a6b4fe | 2001-12-21 14:56:54 +1100 | [diff] [blame] | 1133 | void * |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1134 | packet_get_raw(int *length_ptr) |
| 1135 | { |
| 1136 | int bytes = buffer_len(&incoming_packet); |
| 1137 | if (length_ptr != NULL) |
| 1138 | *length_ptr = bytes; |
| 1139 | return buffer_ptr(&incoming_packet); |
| 1140 | } |
| 1141 | |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 1142 | int |
| 1143 | packet_remaining(void) |
| 1144 | { |
| 1145 | return buffer_len(&incoming_packet); |
| 1146 | } |
| 1147 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1148 | /* |
| 1149 | * Returns a string from the packet data. The string is allocated using |
| 1150 | * xmalloc; it is the responsibility of the calling program to free it when |
| 1151 | * no longer needed. The length_ptr argument may be NULL, or point to an |
| 1152 | * integer into which the length of the string is stored. |
| 1153 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1154 | |
Damien Miller | 5a6b4fe | 2001-12-21 14:56:54 +1100 | [diff] [blame] | 1155 | void * |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1156 | packet_get_string(u_int *length_ptr) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1157 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1158 | return buffer_get_string(&incoming_packet, length_ptr); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1159 | } |
| 1160 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1161 | /* |
| 1162 | * Sends a diagnostic message from the server to the client. This message |
| 1163 | * can be sent at any time (but not while constructing another message). The |
| 1164 | * message is printed immediately, but only if the client is being executed |
| 1165 | * in verbose mode. These messages are primarily intended to ease debugging |
| 1166 | * authentication problems. The length of the formatted message must not |
| 1167 | * exceed 1024 bytes. This will automatically call packet_write_wait. |
| 1168 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1169 | |
| 1170 | void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1171 | packet_send_debug(const char *fmt,...) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1172 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1173 | char buf[1024]; |
| 1174 | va_list args; |
| 1175 | |
Ben Lindstrom | a14ee47 | 2000-12-07 01:24:58 +0000 | [diff] [blame] | 1176 | if (compat20 && (datafellows & SSH_BUG_DEBUG)) |
| 1177 | return; |
| 1178 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1179 | va_start(args, fmt); |
| 1180 | vsnprintf(buf, sizeof(buf), fmt, args); |
| 1181 | va_end(args); |
| 1182 | |
Damien Miller | 7c8af4f | 2000-05-01 08:24:07 +1000 | [diff] [blame] | 1183 | if (compat20) { |
| 1184 | packet_start(SSH2_MSG_DEBUG); |
| 1185 | packet_put_char(0); /* bool: always display */ |
| 1186 | packet_put_cstring(buf); |
| 1187 | packet_put_cstring(""); |
| 1188 | } else { |
| 1189 | packet_start(SSH_MSG_DEBUG); |
| 1190 | packet_put_cstring(buf); |
| 1191 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1192 | packet_send(); |
| 1193 | packet_write_wait(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1194 | } |
| 1195 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1196 | /* |
| 1197 | * Logs the error plus constructs and sends a disconnect packet, closes the |
| 1198 | * connection, and exits. This function never returns. The error message |
| 1199 | * should not contain a newline. The length of the formatted message must |
| 1200 | * not exceed 1024 bytes. |
| 1201 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1202 | |
| 1203 | void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1204 | packet_disconnect(const char *fmt,...) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1205 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1206 | char buf[1024]; |
| 1207 | va_list args; |
| 1208 | static int disconnecting = 0; |
| 1209 | if (disconnecting) /* Guard against recursive invocations. */ |
| 1210 | fatal("packet_disconnect called recursively."); |
| 1211 | disconnecting = 1; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1212 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1213 | /* |
| 1214 | * Format the message. Note that the caller must make sure the |
| 1215 | * message is of limited size. |
| 1216 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1217 | va_start(args, fmt); |
| 1218 | vsnprintf(buf, sizeof(buf), fmt, args); |
| 1219 | va_end(args); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1220 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1221 | /* Send the disconnect message to the other side, and wait for it to get sent. */ |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1222 | if (compat20) { |
| 1223 | packet_start(SSH2_MSG_DISCONNECT); |
| 1224 | packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR); |
| 1225 | packet_put_cstring(buf); |
| 1226 | packet_put_cstring(""); |
| 1227 | } else { |
| 1228 | packet_start(SSH_MSG_DISCONNECT); |
Ben Lindstrom | 664408d | 2001-06-09 01:42:01 +0000 | [diff] [blame] | 1229 | packet_put_cstring(buf); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1230 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1231 | packet_send(); |
| 1232 | packet_write_wait(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1233 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1234 | /* Stop listening for connections. */ |
Ben Lindstrom | 601e436 | 2001-06-21 03:19:23 +0000 | [diff] [blame] | 1235 | channel_close_all(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1236 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1237 | /* Close the connection. */ |
| 1238 | packet_close(); |
| 1239 | |
| 1240 | /* Display the error locally and exit. */ |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 1241 | log("Disconnecting: %.100s", buf); |
| 1242 | fatal_cleanup(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1243 | } |
| 1244 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1245 | /* Checks if there is any buffered output, and tries to write some of the output. */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1246 | |
| 1247 | void |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 1248 | packet_write_poll(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1249 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1250 | int len = buffer_len(&output); |
| 1251 | if (len > 0) { |
| 1252 | len = write(connection_out, buffer_ptr(&output), len); |
| 1253 | if (len <= 0) { |
| 1254 | if (errno == EAGAIN) |
| 1255 | return; |
| 1256 | else |
| 1257 | fatal("Write failed: %.100s", strerror(errno)); |
| 1258 | } |
| 1259 | buffer_consume(&output, len); |
| 1260 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1261 | } |
| 1262 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1263 | /* |
| 1264 | * Calls packet_write_poll repeatedly until all pending output data has been |
| 1265 | * written. |
| 1266 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1267 | |
| 1268 | void |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 1269 | packet_write_wait(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1270 | { |
Ben Lindstrom | cb978aa | 2001-03-05 07:07:49 +0000 | [diff] [blame] | 1271 | fd_set *setp; |
| 1272 | |
| 1273 | setp = (fd_set *)xmalloc(howmany(connection_out + 1, NFDBITS) * |
| 1274 | sizeof(fd_mask)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1275 | packet_write_poll(); |
| 1276 | while (packet_have_data_to_write()) { |
Ben Lindstrom | cb978aa | 2001-03-05 07:07:49 +0000 | [diff] [blame] | 1277 | memset(setp, 0, howmany(connection_out + 1, NFDBITS) * |
| 1278 | sizeof(fd_mask)); |
| 1279 | FD_SET(connection_out, setp); |
| 1280 | while (select(connection_out + 1, NULL, setp, NULL, NULL) == -1 && |
Ben Lindstrom | f945251 | 2001-02-15 03:12:08 +0000 | [diff] [blame] | 1281 | (errno == EAGAIN || errno == EINTR)) |
| 1282 | ; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1283 | packet_write_poll(); |
| 1284 | } |
Ben Lindstrom | cb978aa | 2001-03-05 07:07:49 +0000 | [diff] [blame] | 1285 | xfree(setp); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1286 | } |
| 1287 | |
| 1288 | /* Returns true if there is buffered data to write to the connection. */ |
| 1289 | |
| 1290 | int |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 1291 | packet_have_data_to_write(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1292 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1293 | return buffer_len(&output) != 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1294 | } |
| 1295 | |
| 1296 | /* Returns true if there is not too much data to write to the connection. */ |
| 1297 | |
| 1298 | int |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 1299 | packet_not_very_much_data_to_write(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1300 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1301 | if (interactive_mode) |
| 1302 | return buffer_len(&output) < 16384; |
| 1303 | else |
| 1304 | return buffer_len(&output) < 128 * 1024; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1305 | } |
| 1306 | |
| 1307 | /* Informs that the current session is interactive. Sets IP flags for that. */ |
| 1308 | |
| 1309 | void |
Ben Lindstrom | bf555ba | 2001-01-18 02:04:35 +0000 | [diff] [blame] | 1310 | packet_set_interactive(int interactive) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1311 | { |
Ben Lindstrom | bf555ba | 2001-01-18 02:04:35 +0000 | [diff] [blame] | 1312 | static int called = 0; |
Damien Miller | 0bcf9ea | 2001-02-27 14:03:30 +1100 | [diff] [blame] | 1313 | #if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) |
Ben Lindstrom | bf555ba | 2001-01-18 02:04:35 +0000 | [diff] [blame] | 1314 | int lowdelay = IPTOS_LOWDELAY; |
| 1315 | int throughput = IPTOS_THROUGHPUT; |
Damien Miller | 0bcf9ea | 2001-02-27 14:03:30 +1100 | [diff] [blame] | 1316 | #endif |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1317 | |
Ben Lindstrom | bf555ba | 2001-01-18 02:04:35 +0000 | [diff] [blame] | 1318 | if (called) |
| 1319 | return; |
| 1320 | called = 1; |
| 1321 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1322 | /* Record that we are in interactive mode. */ |
| 1323 | interactive_mode = interactive; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1324 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1325 | /* Only set socket options if using a socket. */ |
| 1326 | if (!packet_connection_is_on_socket()) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1327 | return; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1328 | /* |
Ben Lindstrom | 2f959b4 | 2001-01-11 06:20:23 +0000 | [diff] [blame] | 1329 | * IPTOS_LOWDELAY and IPTOS_THROUGHPUT are IPv4 only |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1330 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1331 | if (interactive) { |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1332 | /* |
| 1333 | * Set IP options for an interactive connection. Use |
| 1334 | * IPTOS_LOWDELAY and TCP_NODELAY. |
| 1335 | */ |
Damien Miller | 2ae714f | 2000-07-11 09:29:50 +1000 | [diff] [blame] | 1336 | #if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) |
Ben Lindstrom | 2f959b4 | 2001-01-11 06:20:23 +0000 | [diff] [blame] | 1337 | if (packet_connection_is_ipv4()) { |
Kevin Steves | 0c69615 | 2001-01-24 13:47:43 +0000 | [diff] [blame] | 1338 | if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, |
Ben Lindstrom | 733a235 | 2002-03-05 01:31:28 +0000 | [diff] [blame] | 1339 | &lowdelay, sizeof(lowdelay)) < 0) |
Kevin Steves | 0c69615 | 2001-01-24 13:47:43 +0000 | [diff] [blame] | 1340 | error("setsockopt IPTOS_LOWDELAY: %.100s", |
Ben Lindstrom | 2f959b4 | 2001-01-11 06:20:23 +0000 | [diff] [blame] | 1341 | strerror(errno)); |
| 1342 | } |
Damien Miller | 615f939 | 2000-05-17 22:53:33 +1000 | [diff] [blame] | 1343 | #endif |
Damien Miller | 398e1cf | 2002-02-05 11:52:13 +1100 | [diff] [blame] | 1344 | set_nodelay(connection_in); |
Ben Lindstrom | 2f959b4 | 2001-01-11 06:20:23 +0000 | [diff] [blame] | 1345 | } else if (packet_connection_is_ipv4()) { |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1346 | /* |
| 1347 | * Set IP options for a non-interactive connection. Use |
| 1348 | * IPTOS_THROUGHPUT. |
| 1349 | */ |
Damien Miller | 2ae714f | 2000-07-11 09:29:50 +1000 | [diff] [blame] | 1350 | #if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) |
Ben Lindstrom | 733a235 | 2002-03-05 01:31:28 +0000 | [diff] [blame] | 1351 | if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, &throughput, |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1352 | sizeof(throughput)) < 0) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1353 | error("setsockopt IPTOS_THROUGHPUT: %.100s", strerror(errno)); |
Damien Miller | 615f939 | 2000-05-17 22:53:33 +1000 | [diff] [blame] | 1354 | #endif |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1355 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1356 | } |
| 1357 | |
| 1358 | /* Returns true if the current connection is interactive. */ |
| 1359 | |
| 1360 | int |
Ben Lindstrom | 3c36bb2 | 2001-12-06 17:55:26 +0000 | [diff] [blame] | 1361 | packet_is_interactive(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1362 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1363 | return interactive_mode; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1364 | } |
Damien Miller | 6162d12 | 1999-11-21 13:23:52 +1100 | [diff] [blame] | 1365 | |
| 1366 | int |
| 1367 | packet_set_maxsize(int s) |
| 1368 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1369 | static int called = 0; |
| 1370 | if (called) { |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1371 | log("packet_set_maxsize: called twice: old %d new %d", |
| 1372 | max_packet_size, s); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1373 | return -1; |
| 1374 | } |
| 1375 | if (s < 4 * 1024 || s > 1024 * 1024) { |
| 1376 | log("packet_set_maxsize: bad size %d", s); |
| 1377 | return -1; |
| 1378 | } |
Ben Lindstrom | ae3de4b | 2001-10-03 17:10:17 +0000 | [diff] [blame] | 1379 | called = 1; |
Ben Lindstrom | 16d45b3 | 2001-06-13 04:39:18 +0000 | [diff] [blame] | 1380 | debug("packet_set_maxsize: setting to %d", s); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1381 | max_packet_size = s; |
| 1382 | return s; |
Damien Miller | 6162d12 | 1999-11-21 13:23:52 +1100 | [diff] [blame] | 1383 | } |
Ben Lindstrom | 5699c5f | 2001-03-05 06:17:49 +0000 | [diff] [blame] | 1384 | |
Damien Miller | 9f64390 | 2001-11-12 11:02:52 +1100 | [diff] [blame] | 1385 | /* roundup current message to pad bytes */ |
| 1386 | void |
| 1387 | packet_add_padding(u_char pad) |
| 1388 | { |
| 1389 | extra_pad = pad; |
| 1390 | } |
| 1391 | |
Ben Lindstrom | 5699c5f | 2001-03-05 06:17:49 +0000 | [diff] [blame] | 1392 | /* |
| 1393 | * 9.2. Ignored Data Message |
Ben Lindstrom | a370005 | 2001-04-05 23:26:32 +0000 | [diff] [blame] | 1394 | * |
Ben Lindstrom | 5699c5f | 2001-03-05 06:17:49 +0000 | [diff] [blame] | 1395 | * byte SSH_MSG_IGNORE |
| 1396 | * string data |
Ben Lindstrom | a370005 | 2001-04-05 23:26:32 +0000 | [diff] [blame] | 1397 | * |
Ben Lindstrom | 5699c5f | 2001-03-05 06:17:49 +0000 | [diff] [blame] | 1398 | * All implementations MUST understand (and ignore) this message at any |
| 1399 | * time (after receiving the protocol version). No implementation is |
| 1400 | * required to send them. This message can be used as an additional |
| 1401 | * protection measure against advanced traffic analysis techniques. |
| 1402 | */ |
Ben Lindstrom | e229b25 | 2001-03-05 06:28:06 +0000 | [diff] [blame] | 1403 | void |
| 1404 | packet_send_ignore(int nbytes) |
| 1405 | { |
| 1406 | u_int32_t rand = 0; |
| 1407 | int i; |
| 1408 | |
| 1409 | packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE); |
Ben Lindstrom | 5699c5f | 2001-03-05 06:17:49 +0000 | [diff] [blame] | 1410 | packet_put_int(nbytes); |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 1411 | for (i = 0; i < nbytes; i++) { |
Ben Lindstrom | 5699c5f | 2001-03-05 06:17:49 +0000 | [diff] [blame] | 1412 | if (i % 4 == 0) |
| 1413 | rand = arc4random(); |
| 1414 | packet_put_char(rand & 0xff); |
| 1415 | rand >>= 8; |
| 1416 | } |
| 1417 | } |