Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1 | /* |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 2 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 3 | * packet.c |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 4 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 5 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 6 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 7 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 8 | * All rights reserved |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 9 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 10 | * Created: Sat Mar 18 02:40:40 1995 ylo |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 11 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 12 | * This file contains code implementing the packet protocol and communication |
| 13 | * 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] | 14 | * |
| 15 | * SSH2 packet format added by Markus Friedl. |
| 16 | * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 17 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 18 | |
| 19 | #include "includes.h" |
Damien Miller | 615f939 | 2000-05-17 22:53:33 +1000 | [diff] [blame] | 20 | RCSID("$Id: packet.c,v 1.23 2000/05/17 12:53:35 damien Exp $"); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 21 | |
| 22 | #include "xmalloc.h" |
| 23 | #include "buffer.h" |
| 24 | #include "packet.h" |
| 25 | #include "bufaux.h" |
| 26 | #include "ssh.h" |
| 27 | #include "crc32.h" |
| 28 | #include "cipher.h" |
| 29 | #include "getput.h" |
| 30 | |
| 31 | #include "compress.h" |
| 32 | #include "deattack.h" |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 33 | #include "channels.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 34 | |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 35 | #include "compat.h" |
| 36 | #include "ssh2.h" |
| 37 | |
Damien Miller | 5f05637 | 2000-04-16 12:31:48 +1000 | [diff] [blame] | 38 | #include <openssl/bn.h> |
| 39 | #include <openssl/dh.h> |
| 40 | #include <openssl/hmac.h> |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 41 | #include "buffer.h" |
| 42 | #include "kex.h" |
| 43 | #include "hmac.h" |
| 44 | |
| 45 | #ifdef PACKET_DEBUG |
| 46 | #define DBG(x) x |
| 47 | #else |
| 48 | #define DBG(x) |
| 49 | #endif |
| 50 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 51 | /* |
| 52 | * This variable contains the file descriptors used for communicating with |
| 53 | * the other side. connection_in is used for reading; connection_out for |
| 54 | * writing. These can be the same descriptor, in which case it is assumed to |
| 55 | * be a socket. |
| 56 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 57 | static int connection_in = -1; |
| 58 | static int connection_out = -1; |
| 59 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 60 | /* |
| 61 | * Cipher type. This value is only used to determine whether to pad the |
| 62 | * packets with zeroes or random data. |
| 63 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 64 | static int cipher_type = SSH_CIPHER_NONE; |
| 65 | |
| 66 | /* Protocol flags for the remote side. */ |
| 67 | static unsigned int remote_protocol_flags = 0; |
| 68 | |
| 69 | /* Encryption context for receiving data. This is only used for decryption. */ |
| 70 | static CipherContext receive_context; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 71 | |
| 72 | /* Encryption context for sending data. This is only used for encryption. */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 73 | static CipherContext send_context; |
| 74 | |
| 75 | /* Buffer for raw input data from the socket. */ |
| 76 | static Buffer input; |
| 77 | |
| 78 | /* Buffer for raw output data going to the socket. */ |
| 79 | static Buffer output; |
| 80 | |
| 81 | /* Buffer for the partial outgoing packet being constructed. */ |
| 82 | static Buffer outgoing_packet; |
| 83 | |
| 84 | /* Buffer for the incoming packet currently being processed. */ |
| 85 | static Buffer incoming_packet; |
| 86 | |
| 87 | /* Scratch buffer for packet compression/decompression. */ |
| 88 | static Buffer compression_buffer; |
| 89 | |
| 90 | /* Flag indicating whether packet compression/decompression is enabled. */ |
| 91 | static int packet_compression = 0; |
| 92 | |
Damien Miller | 6162d12 | 1999-11-21 13:23:52 +1100 | [diff] [blame] | 93 | /* default maximum packet size */ |
| 94 | int max_packet_size = 32768; |
| 95 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 96 | /* Flag indicating whether this module has been initialized. */ |
| 97 | static int initialized = 0; |
| 98 | |
| 99 | /* Set to true if the connection is interactive. */ |
| 100 | static int interactive_mode = 0; |
| 101 | |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 102 | /* True if SSH2 packet format is used */ |
| 103 | int use_ssh2_packet_format = 0; |
| 104 | |
| 105 | /* Session key information for Encryption and MAC */ |
| 106 | Kex *kex = NULL; |
| 107 | |
| 108 | void |
| 109 | packet_set_kex(Kex *k) |
| 110 | { |
| 111 | if( k->mac[MODE_IN ].key == NULL || |
| 112 | k->enc[MODE_IN ].key == NULL || |
| 113 | k->enc[MODE_IN ].iv == NULL || |
| 114 | k->mac[MODE_OUT].key == NULL || |
| 115 | k->enc[MODE_OUT].key == NULL || |
| 116 | k->enc[MODE_OUT].iv == NULL) |
| 117 | fatal("bad KEX"); |
| 118 | kex = k; |
| 119 | } |
| 120 | void |
| 121 | clear_enc_keys(Enc *enc, int len) |
| 122 | { |
| 123 | memset(enc->iv, 0, len); |
| 124 | memset(enc->key, 0, len); |
| 125 | xfree(enc->iv); |
| 126 | xfree(enc->key); |
| 127 | enc->iv = NULL; |
| 128 | enc->key = NULL; |
| 129 | } |
| 130 | void |
| 131 | packet_set_ssh2_format(void) |
| 132 | { |
Damien Miller | 35dabd0 | 2000-05-01 21:10:33 +1000 | [diff] [blame] | 133 | DBG(debug("use_ssh2_packet_format")); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 134 | use_ssh2_packet_format = 1; |
| 135 | } |
| 136 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 137 | /* |
| 138 | * Sets the descriptors used for communication. Disables encryption until |
| 139 | * packet_set_encryption_key is called. |
| 140 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 141 | void |
| 142 | packet_set_connection(int fd_in, int fd_out) |
| 143 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 144 | connection_in = fd_in; |
| 145 | connection_out = fd_out; |
| 146 | cipher_type = SSH_CIPHER_NONE; |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 147 | cipher_set_key(&send_context, SSH_CIPHER_NONE, (unsigned char *) "", 0); |
| 148 | cipher_set_key(&receive_context, SSH_CIPHER_NONE, (unsigned char *) "", 0); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 149 | if (!initialized) { |
| 150 | initialized = 1; |
| 151 | buffer_init(&input); |
| 152 | buffer_init(&output); |
| 153 | buffer_init(&outgoing_packet); |
| 154 | buffer_init(&incoming_packet); |
| 155 | } |
| 156 | /* Kludge: arrange the close function to be called from fatal(). */ |
| 157 | fatal_add_cleanup((void (*) (void *)) packet_close, NULL); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 158 | } |
| 159 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 160 | /* Returns 1 if remote host is connected via socket, 0 if not. */ |
| 161 | |
| 162 | int |
| 163 | packet_connection_is_on_socket() |
| 164 | { |
| 165 | struct sockaddr_storage from, to; |
| 166 | socklen_t fromlen, tolen; |
| 167 | |
| 168 | /* filedescriptors in and out are the same, so it's a socket */ |
| 169 | if (connection_in == connection_out) |
| 170 | return 1; |
| 171 | fromlen = sizeof(from); |
| 172 | memset(&from, 0, sizeof(from)); |
Damien Miller | f052aaf | 2000-01-22 19:47:21 +1100 | [diff] [blame] | 173 | if (getpeername(connection_in, (struct sockaddr *)&from, &fromlen) < 0) |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 174 | return 0; |
| 175 | tolen = sizeof(to); |
| 176 | memset(&to, 0, sizeof(to)); |
Damien Miller | f052aaf | 2000-01-22 19:47:21 +1100 | [diff] [blame] | 177 | if (getpeername(connection_out, (struct sockaddr *)&to, &tolen) < 0) |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 178 | return 0; |
| 179 | if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0) |
| 180 | return 0; |
| 181 | if (from.ss_family != AF_INET && from.ss_family != AF_INET6) |
| 182 | return 0; |
| 183 | return 1; |
| 184 | } |
| 185 | |
| 186 | /* returns 1 if connection is via ipv4 */ |
| 187 | |
| 188 | int |
| 189 | packet_connection_is_ipv4() |
| 190 | { |
| 191 | struct sockaddr_storage to; |
Damien Miller | 6fe375d | 2000-01-23 09:38:00 +1100 | [diff] [blame] | 192 | socklen_t tolen = sizeof(to); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 193 | |
| 194 | memset(&to, 0, sizeof(to)); |
| 195 | if (getsockname(connection_out, (struct sockaddr *)&to, &tolen) < 0) |
| 196 | return 0; |
| 197 | if (to.ss_family != AF_INET) |
| 198 | return 0; |
| 199 | return 1; |
| 200 | } |
| 201 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 202 | /* Sets the connection into non-blocking mode. */ |
| 203 | |
| 204 | void |
| 205 | packet_set_nonblocking() |
| 206 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 207 | /* Set the socket into non-blocking mode. */ |
| 208 | if (fcntl(connection_in, F_SETFL, O_NONBLOCK) < 0) |
| 209 | error("fcntl O_NONBLOCK: %.100s", strerror(errno)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 210 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 211 | if (connection_out != connection_in) { |
| 212 | if (fcntl(connection_out, F_SETFL, O_NONBLOCK) < 0) |
| 213 | error("fcntl O_NONBLOCK: %.100s", strerror(errno)); |
| 214 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 215 | } |
| 216 | |
| 217 | /* Returns the socket used for reading. */ |
| 218 | |
| 219 | int |
| 220 | packet_get_connection_in() |
| 221 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 222 | return connection_in; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 223 | } |
| 224 | |
| 225 | /* Returns the descriptor used for writing. */ |
| 226 | |
| 227 | int |
| 228 | packet_get_connection_out() |
| 229 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 230 | return connection_out; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 231 | } |
| 232 | |
| 233 | /* Closes the connection and clears and frees internal data structures. */ |
| 234 | |
| 235 | void |
| 236 | packet_close() |
| 237 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 238 | if (!initialized) |
| 239 | return; |
| 240 | initialized = 0; |
| 241 | if (connection_in == connection_out) { |
| 242 | shutdown(connection_out, SHUT_RDWR); |
| 243 | close(connection_out); |
| 244 | } else { |
| 245 | close(connection_in); |
| 246 | close(connection_out); |
| 247 | } |
| 248 | buffer_free(&input); |
| 249 | buffer_free(&output); |
| 250 | buffer_free(&outgoing_packet); |
| 251 | buffer_free(&incoming_packet); |
| 252 | if (packet_compression) { |
| 253 | buffer_free(&compression_buffer); |
| 254 | buffer_compress_uninit(); |
| 255 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 256 | } |
| 257 | |
| 258 | /* Sets remote side protocol flags. */ |
| 259 | |
| 260 | void |
| 261 | packet_set_protocol_flags(unsigned int protocol_flags) |
| 262 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 263 | remote_protocol_flags = protocol_flags; |
| 264 | channel_set_options((protocol_flags & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) != 0); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 265 | } |
| 266 | |
| 267 | /* Returns the remote protocol flags set earlier by the above function. */ |
| 268 | |
| 269 | unsigned int |
| 270 | packet_get_protocol_flags() |
| 271 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 272 | return remote_protocol_flags; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 273 | } |
| 274 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 275 | /* |
| 276 | * Starts packet compression from the next packet on in both directions. |
| 277 | * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip. |
| 278 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 279 | |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 280 | /*** XXXXX todo: kex means re-init */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 281 | void |
| 282 | packet_start_compression(int level) |
| 283 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 284 | if (packet_compression) |
| 285 | fatal("Compression already enabled."); |
| 286 | packet_compression = 1; |
| 287 | buffer_init(&compression_buffer); |
| 288 | buffer_compress_init(level); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 289 | } |
| 290 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 291 | /* |
| 292 | * Encrypts the given number of bytes, copying from src to dest. bytes is |
| 293 | * known to be a multiple of 8. |
| 294 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 295 | |
| 296 | void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 297 | packet_encrypt(CipherContext * cc, void *dest, void *src, |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 298 | unsigned int bytes) |
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 | cipher_encrypt(cc, dest, src, bytes); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 301 | } |
| 302 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 303 | /* |
| 304 | * Decrypts the given number of bytes, copying from src to dest. bytes is |
| 305 | * known to be a multiple of 8. |
| 306 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 307 | |
| 308 | void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 309 | packet_decrypt(CipherContext * cc, void *dest, void *src, |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 310 | unsigned int bytes) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 311 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 312 | int i; |
| 313 | |
| 314 | if ((bytes % 8) != 0) |
| 315 | fatal("packet_decrypt: bad ciphertext length %d", bytes); |
| 316 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 317 | /* |
| 318 | * Cryptographic attack detector for ssh - Modifications for packet.c |
| 319 | * (C)1998 CORE-SDI, Buenos Aires Argentina Ariel Futoransky(futo@core-sdi.com) |
| 320 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 321 | |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 322 | if (cc->type == SSH_CIPHER_NONE || compat20) { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 323 | i = DEATTACK_OK; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 324 | } else { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 325 | i = detect_attack(src, bytes, NULL); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 326 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 327 | if (i == DEATTACK_DETECTED) |
| 328 | packet_disconnect("crc32 compensation attack: network attack detected"); |
| 329 | |
| 330 | cipher_decrypt(cc, dest, src, bytes); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 331 | } |
| 332 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 333 | /* |
| 334 | * Causes any further packets to be encrypted using the given key. The same |
| 335 | * key is used for both sending and reception. However, both directions are |
| 336 | * encrypted independently of each other. |
| 337 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 338 | |
| 339 | void |
| 340 | packet_set_encryption_key(const unsigned char *key, unsigned int keylen, |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 341 | int cipher) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 342 | { |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 343 | if (keylen < 20) |
| 344 | fatal("keylen too small: %d", keylen); |
| 345 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 346 | /* All other ciphers use the same key in both directions for now. */ |
Damien Miller | 1383bd8 | 2000-04-06 12:32:37 +1000 | [diff] [blame] | 347 | cipher_set_key(&receive_context, cipher, key, keylen); |
| 348 | cipher_set_key(&send_context, cipher, key, keylen); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 349 | } |
| 350 | |
| 351 | /* Starts constructing a packet to send. */ |
| 352 | |
| 353 | void |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 354 | packet_start1(int type) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 355 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 356 | char buf[9]; |
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 | buffer_clear(&outgoing_packet); |
| 359 | memset(buf, 0, 8); |
| 360 | buf[8] = type; |
| 361 | buffer_append(&outgoing_packet, buf, 9); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 362 | } |
| 363 | |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 364 | void |
| 365 | packet_start2(int type) |
| 366 | { |
| 367 | char buf[4+1+1]; |
| 368 | |
| 369 | buffer_clear(&outgoing_packet); |
| 370 | memset(buf, 0, sizeof buf); |
| 371 | /* buf[0..3] = payload_len; */ |
| 372 | /* buf[4] = pad_len; */ |
| 373 | buf[5] = type & 0xff; |
| 374 | buffer_append(&outgoing_packet, buf, sizeof buf); |
| 375 | } |
| 376 | |
| 377 | void |
| 378 | packet_start(int type) |
| 379 | { |
| 380 | DBG(debug("packet_start[%d]",type)); |
| 381 | if (use_ssh2_packet_format) |
| 382 | packet_start2(type); |
| 383 | else |
| 384 | packet_start1(type); |
| 385 | } |
| 386 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 387 | /* Appends a character to the packet data. */ |
| 388 | |
| 389 | void |
| 390 | packet_put_char(int value) |
| 391 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 392 | char ch = value; |
| 393 | buffer_append(&outgoing_packet, &ch, 1); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 394 | } |
| 395 | |
| 396 | /* Appends an integer to the packet data. */ |
| 397 | |
| 398 | void |
| 399 | packet_put_int(unsigned int value) |
| 400 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 401 | buffer_put_int(&outgoing_packet, value); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 402 | } |
| 403 | |
| 404 | /* Appends a string to packet data. */ |
| 405 | |
| 406 | void |
| 407 | packet_put_string(const char *buf, unsigned int len) |
| 408 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 409 | buffer_put_string(&outgoing_packet, buf, len); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 410 | } |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 411 | void |
| 412 | packet_put_cstring(const char *str) |
| 413 | { |
| 414 | buffer_put_string(&outgoing_packet, str, strlen(str)); |
| 415 | } |
| 416 | |
| 417 | void |
| 418 | packet_put_raw(const char *buf, unsigned int len) |
| 419 | { |
| 420 | buffer_append(&outgoing_packet, buf, len); |
| 421 | } |
| 422 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 423 | |
| 424 | /* Appends an arbitrary precision integer to packet data. */ |
| 425 | |
| 426 | void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 427 | packet_put_bignum(BIGNUM * value) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 428 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 429 | buffer_put_bignum(&outgoing_packet, value); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 430 | } |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 431 | void |
| 432 | packet_put_bignum2(BIGNUM * value) |
| 433 | { |
| 434 | buffer_put_bignum2(&outgoing_packet, value); |
| 435 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 436 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 437 | /* |
| 438 | * Finalizes and sends the packet. If the encryption key has been set, |
| 439 | * encrypts the packet before sending. |
| 440 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 441 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 442 | void |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 443 | packet_send1() |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 444 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 445 | char buf[8], *cp; |
| 446 | int i, padding, len; |
| 447 | unsigned int checksum; |
| 448 | u_int32_t rand = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 449 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 450 | /* |
| 451 | * If using packet compression, compress the payload of the outgoing |
| 452 | * packet. |
| 453 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 454 | if (packet_compression) { |
| 455 | buffer_clear(&compression_buffer); |
| 456 | /* Skip padding. */ |
| 457 | buffer_consume(&outgoing_packet, 8); |
| 458 | /* padding */ |
| 459 | buffer_append(&compression_buffer, "\0\0\0\0\0\0\0\0", 8); |
| 460 | buffer_compress(&outgoing_packet, &compression_buffer); |
| 461 | buffer_clear(&outgoing_packet); |
| 462 | buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), |
| 463 | buffer_len(&compression_buffer)); |
| 464 | } |
| 465 | /* Compute packet length without padding (add checksum, remove padding). */ |
| 466 | len = buffer_len(&outgoing_packet) + 4 - 8; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 467 | |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 468 | /* Insert padding. Initialized to zero in packet_start1() */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 469 | padding = 8 - len % 8; |
| 470 | if (cipher_type != SSH_CIPHER_NONE) { |
| 471 | cp = buffer_ptr(&outgoing_packet); |
| 472 | for (i = 0; i < padding; i++) { |
| 473 | if (i % 4 == 0) |
| 474 | rand = arc4random(); |
| 475 | cp[7 - i] = rand & 0xff; |
| 476 | rand >>= 8; |
| 477 | } |
| 478 | } |
| 479 | buffer_consume(&outgoing_packet, 8 - padding); |
| 480 | |
| 481 | /* Add check bytes. */ |
| 482 | checksum = crc32((unsigned char *) buffer_ptr(&outgoing_packet), |
| 483 | buffer_len(&outgoing_packet)); |
| 484 | PUT_32BIT(buf, checksum); |
| 485 | buffer_append(&outgoing_packet, buf, 4); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 486 | |
| 487 | #ifdef PACKET_DEBUG |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 488 | fprintf(stderr, "packet_send plain: "); |
| 489 | buffer_dump(&outgoing_packet); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 490 | #endif |
| 491 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 492 | /* Append to output. */ |
| 493 | PUT_32BIT(buf, len); |
| 494 | buffer_append(&output, buf, 4); |
| 495 | buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); |
| 496 | packet_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), |
| 497 | buffer_len(&outgoing_packet)); |
| 498 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 499 | #ifdef PACKET_DEBUG |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 500 | fprintf(stderr, "encrypted: "); |
| 501 | buffer_dump(&output); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 502 | #endif |
| 503 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 504 | buffer_clear(&outgoing_packet); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 505 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 506 | /* |
| 507 | * Note that the packet is now only buffered in output. It won\'t be |
| 508 | * actually sent until packet_write_wait or packet_write_poll is |
| 509 | * called. |
| 510 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 511 | } |
| 512 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 513 | /* |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 514 | * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) |
| 515 | */ |
| 516 | void |
| 517 | packet_send2() |
| 518 | { |
| 519 | unsigned char *macbuf = NULL; |
| 520 | char *cp; |
| 521 | unsigned int packet_length = 0; |
| 522 | unsigned int i, padlen, len; |
| 523 | u_int32_t rand = 0; |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 524 | static unsigned int seqnr = 0; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 525 | int type; |
| 526 | Enc *enc = NULL; |
| 527 | Mac *mac = NULL; |
| 528 | Comp *comp = NULL; |
| 529 | int block_size; |
| 530 | |
| 531 | if (kex != NULL) { |
| 532 | enc = &kex->enc[MODE_OUT]; |
| 533 | mac = &kex->mac[MODE_OUT]; |
| 534 | comp = &kex->comp[MODE_OUT]; |
| 535 | } |
| 536 | block_size = enc ? enc->block_size : 8; |
| 537 | |
| 538 | cp = buffer_ptr(&outgoing_packet); |
| 539 | type = cp[5] & 0xff; |
| 540 | |
| 541 | #ifdef PACKET_DEBUG |
| 542 | fprintf(stderr, "plain: "); |
| 543 | buffer_dump(&outgoing_packet); |
| 544 | #endif |
| 545 | |
| 546 | if (comp && comp->enabled) { |
| 547 | len = buffer_len(&outgoing_packet); |
| 548 | /* skip header, compress only payload */ |
| 549 | buffer_consume(&outgoing_packet, 5); |
| 550 | buffer_clear(&compression_buffer); |
| 551 | buffer_compress(&outgoing_packet, &compression_buffer); |
| 552 | buffer_clear(&outgoing_packet); |
| 553 | buffer_append(&outgoing_packet, "\0\0\0\0\0", 5); |
| 554 | buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), |
| 555 | buffer_len(&compression_buffer)); |
| 556 | DBG(debug("compression: raw %d compressed %d", len, |
| 557 | buffer_len(&outgoing_packet))); |
| 558 | } |
| 559 | |
| 560 | /* sizeof (packet_len + pad_len + payload) */ |
| 561 | len = buffer_len(&outgoing_packet); |
| 562 | |
| 563 | /* |
| 564 | * calc size of padding, alloc space, get random data, |
| 565 | * minimum padding is 4 bytes |
| 566 | */ |
| 567 | padlen = block_size - (len % block_size); |
| 568 | if (padlen < 4) |
| 569 | padlen += block_size; |
| 570 | buffer_append_space(&outgoing_packet, &cp, padlen); |
| 571 | if (enc && enc->type != SSH_CIPHER_NONE) { |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 572 | /* random padding */ |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 573 | for (i = 0; i < padlen; i++) { |
| 574 | if (i % 4 == 0) |
| 575 | rand = arc4random(); |
| 576 | cp[i] = rand & 0xff; |
| 577 | rand <<= 8; |
| 578 | } |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 579 | } else { |
| 580 | /* clear padding */ |
| 581 | memset(cp, 0, padlen); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 582 | } |
| 583 | /* packet_length includes payload, padding and padding length field */ |
| 584 | packet_length = buffer_len(&outgoing_packet) - 4; |
| 585 | cp = buffer_ptr(&outgoing_packet); |
| 586 | PUT_32BIT(cp, packet_length); |
| 587 | cp[4] = padlen & 0xff; |
| 588 | DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen)); |
| 589 | |
| 590 | /* compute MAC over seqnr and packet(length fields, payload, padding) */ |
| 591 | if (mac && mac->enabled) { |
| 592 | macbuf = hmac( mac->md, seqnr, |
| 593 | (unsigned char *) buffer_ptr(&outgoing_packet), |
| 594 | buffer_len(&outgoing_packet), |
| 595 | mac->key, mac->key_len |
| 596 | ); |
| 597 | DBG(debug("done calc HMAC out #%d", seqnr)); |
| 598 | } |
| 599 | /* encrypt packet and append to output buffer. */ |
| 600 | buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); |
| 601 | packet_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), |
| 602 | buffer_len(&outgoing_packet)); |
| 603 | /* append unencrypted MAC */ |
| 604 | if (mac && mac->enabled) |
| 605 | buffer_append(&output, (char *)macbuf, mac->mac_len); |
| 606 | #ifdef PACKET_DEBUG |
| 607 | fprintf(stderr, "encrypted: "); |
| 608 | buffer_dump(&output); |
| 609 | #endif |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 610 | /* increment sequence number for outgoing packets */ |
| 611 | if (++seqnr == 0) |
| 612 | log("outgoing seqnr wraps around"); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 613 | buffer_clear(&outgoing_packet); |
| 614 | |
| 615 | if (type == SSH2_MSG_NEWKEYS) { |
| 616 | if (kex==NULL || mac==NULL || enc==NULL || comp==NULL) |
| 617 | fatal("packet_send2: no KEX"); |
| 618 | if (mac->md != NULL) |
| 619 | mac->enabled = 1; |
Damien Miller | 35dabd0 | 2000-05-01 21:10:33 +1000 | [diff] [blame] | 620 | DBG(debug("cipher_set_key_iv send_context")); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 621 | cipher_set_key_iv(&send_context, enc->type, |
| 622 | enc->key, enc->key_len, |
| 623 | enc->iv, enc->iv_len); |
| 624 | clear_enc_keys(enc, kex->we_need); |
| 625 | if (comp->type != 0 && comp->enabled == 0) { |
| 626 | comp->enabled = 1; |
| 627 | if (! packet_compression) |
| 628 | packet_start_compression(6); |
| 629 | } |
| 630 | } |
| 631 | } |
| 632 | |
| 633 | void |
| 634 | packet_send() |
| 635 | { |
| 636 | if (use_ssh2_packet_format) |
| 637 | packet_send2(); |
| 638 | else |
| 639 | packet_send1(); |
| 640 | DBG(debug("packet_send done")); |
| 641 | } |
| 642 | |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 643 | /* |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 644 | * Waits until a packet has been received, and returns its type. Note that |
| 645 | * no other data is processed until this returns, so this function should not |
| 646 | * be used during the interactive session. |
| 647 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 648 | |
| 649 | int |
| 650 | packet_read(int *payload_len_ptr) |
| 651 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 652 | int type, len; |
| 653 | fd_set set; |
| 654 | char buf[8192]; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 655 | DBG(debug("packet_read()")); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 656 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 657 | /* Since we are blocking, ensure that all written packets have been sent. */ |
| 658 | packet_write_wait(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 659 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 660 | /* Stay in the loop until we have received a complete packet. */ |
| 661 | for (;;) { |
| 662 | /* Try to read a packet from the buffer. */ |
| 663 | type = packet_read_poll(payload_len_ptr); |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 664 | if (!use_ssh2_packet_format && ( |
| 665 | type == SSH_SMSG_SUCCESS |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 666 | || type == SSH_SMSG_FAILURE |
| 667 | || type == SSH_CMSG_EOF |
Damien Miller | e247cc4 | 2000-05-07 12:03:14 +1000 | [diff] [blame] | 668 | || type == SSH_CMSG_EXIT_CONFIRMATION)) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 669 | packet_integrity_check(*payload_len_ptr, 0, type); |
| 670 | /* If we got a packet, return it. */ |
| 671 | if (type != SSH_MSG_NONE) |
| 672 | return type; |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 673 | /* |
| 674 | * Otherwise, wait for some data to arrive, add it to the |
| 675 | * buffer, and try again. |
| 676 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 677 | FD_ZERO(&set); |
| 678 | FD_SET(connection_in, &set); |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 679 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 680 | /* Wait for some data to arrive. */ |
| 681 | select(connection_in + 1, &set, NULL, NULL, NULL); |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 682 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 683 | /* Read data from the socket. */ |
| 684 | len = read(connection_in, buf, sizeof(buf)); |
Damien Miller | 5e7c10e | 1999-12-16 13:18:04 +1100 | [diff] [blame] | 685 | if (len == 0) { |
| 686 | log("Connection closed by %.200s", get_remote_ipaddr()); |
| 687 | fatal_cleanup(); |
| 688 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 689 | if (len < 0) |
| 690 | fatal("Read from socket failed: %.100s", strerror(errno)); |
| 691 | /* Append it to the buffer. */ |
| 692 | packet_process_incoming(buf, len); |
| 693 | } |
| 694 | /* NOTREACHED */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 695 | } |
| 696 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 697 | /* |
| 698 | * Waits until a packet has been received, verifies that its type matches |
| 699 | * that given, and gives a fatal error and exits if there is a mismatch. |
| 700 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 701 | |
| 702 | void |
| 703 | packet_read_expect(int *payload_len_ptr, int expected_type) |
| 704 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 705 | int type; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 706 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 707 | type = packet_read(payload_len_ptr); |
| 708 | if (type != expected_type) |
| 709 | packet_disconnect("Protocol error: expected packet type %d, got %d", |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 710 | expected_type, type); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 711 | } |
| 712 | |
| 713 | /* 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] | 714 | * packet_process_incoming. If so, reads the packet; otherwise returns |
| 715 | * SSH_MSG_NONE. This does not wait for data from the connection. |
| 716 | * |
| 717 | * SSH_MSG_DISCONNECT is handled specially here. Also, |
| 718 | * SSH_MSG_IGNORE messages are skipped by this function and are never returned |
| 719 | * to higher levels. |
| 720 | * |
| 721 | * The returned payload_len does include space consumed by: |
| 722 | * Packet length |
| 723 | * Padding |
| 724 | * Packet type |
| 725 | * Check bytes |
| 726 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 727 | |
| 728 | int |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 729 | packet_read_poll1(int *payload_len_ptr) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 730 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 731 | unsigned int len, padded_len; |
| 732 | unsigned char *ucp; |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 733 | char buf[8], *cp; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 734 | unsigned int checksum, stored_checksum; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 735 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 736 | /* Check if input size is less than minimum packet size. */ |
| 737 | if (buffer_len(&input) < 4 + 8) |
| 738 | return SSH_MSG_NONE; |
| 739 | /* Get length of incoming packet. */ |
| 740 | ucp = (unsigned char *) buffer_ptr(&input); |
| 741 | len = GET_32BIT(ucp); |
| 742 | if (len < 1 + 2 + 2 || len > 256 * 1024) |
| 743 | packet_disconnect("Bad packet length %d.", len); |
| 744 | padded_len = (len + 8) & ~7; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 745 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 746 | /* Check if the packet has been entirely received. */ |
| 747 | if (buffer_len(&input) < 4 + padded_len) |
| 748 | return SSH_MSG_NONE; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 749 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 750 | /* The entire packet is in buffer. */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 751 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 752 | /* Consume packet length. */ |
| 753 | buffer_consume(&input, 4); |
| 754 | |
| 755 | /* Copy data to incoming_packet. */ |
| 756 | buffer_clear(&incoming_packet); |
| 757 | buffer_append_space(&incoming_packet, &cp, padded_len); |
| 758 | packet_decrypt(&receive_context, cp, buffer_ptr(&input), padded_len); |
| 759 | buffer_consume(&input, padded_len); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 760 | |
| 761 | #ifdef PACKET_DEBUG |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 762 | fprintf(stderr, "read_poll plain: "); |
| 763 | buffer_dump(&incoming_packet); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 764 | #endif |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 765 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 766 | /* Compute packet checksum. */ |
| 767 | checksum = crc32((unsigned char *) buffer_ptr(&incoming_packet), |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 768 | buffer_len(&incoming_packet) - 4); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 769 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 770 | /* Skip padding. */ |
| 771 | buffer_consume(&incoming_packet, 8 - len % 8); |
Damien Miller | fd7c911 | 1999-11-08 16:15:55 +1100 | [diff] [blame] | 772 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 773 | /* Test check bytes. */ |
Damien Miller | fd7c911 | 1999-11-08 16:15:55 +1100 | [diff] [blame] | 774 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 775 | if (len != buffer_len(&incoming_packet)) |
| 776 | packet_disconnect("packet_read_poll: len %d != buffer_len %d.", |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 777 | len, buffer_len(&incoming_packet)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 778 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 779 | ucp = (unsigned char *) buffer_ptr(&incoming_packet) + len - 4; |
| 780 | stored_checksum = GET_32BIT(ucp); |
| 781 | if (checksum != stored_checksum) |
| 782 | packet_disconnect("Corrupted check bytes on input."); |
| 783 | buffer_consume_end(&incoming_packet, 4); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 784 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 785 | /* If using packet compression, decompress the packet. */ |
| 786 | if (packet_compression) { |
| 787 | buffer_clear(&compression_buffer); |
| 788 | buffer_uncompress(&incoming_packet, &compression_buffer); |
| 789 | buffer_clear(&incoming_packet); |
| 790 | buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 791 | buffer_len(&compression_buffer)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 792 | } |
| 793 | /* Get packet type. */ |
| 794 | buffer_get(&incoming_packet, &buf[0], 1); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 795 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 796 | /* Return length of payload (without type field). */ |
| 797 | *payload_len_ptr = buffer_len(&incoming_packet); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 798 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 799 | /* Return type. */ |
| 800 | return (unsigned char) buf[0]; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 801 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 802 | |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 803 | int |
| 804 | packet_read_poll2(int *payload_len_ptr) |
| 805 | { |
| 806 | unsigned int padlen, need; |
| 807 | unsigned char buf[8], *macbuf; |
| 808 | unsigned char *ucp; |
| 809 | char *cp; |
| 810 | static unsigned int packet_length = 0; |
| 811 | static unsigned int seqnr = 0; |
| 812 | int type; |
| 813 | int maclen, block_size; |
| 814 | Enc *enc = NULL; |
| 815 | Mac *mac = NULL; |
| 816 | Comp *comp = NULL; |
| 817 | |
| 818 | if (kex != NULL) { |
| 819 | enc = &kex->enc[MODE_IN]; |
| 820 | mac = &kex->mac[MODE_IN]; |
| 821 | comp = &kex->comp[MODE_IN]; |
| 822 | } |
| 823 | maclen = mac && mac->enabled ? mac->mac_len : 0; |
| 824 | block_size = enc ? enc->block_size : 8; |
| 825 | |
| 826 | if (packet_length == 0) { |
| 827 | /* |
| 828 | * check if input size is less than the cipher block size, |
| 829 | * decrypt first block and extract length of incoming packet |
| 830 | */ |
| 831 | if (buffer_len(&input) < block_size) |
| 832 | return SSH_MSG_NONE; |
| 833 | buffer_clear(&incoming_packet); |
| 834 | buffer_append_space(&incoming_packet, &cp, block_size); |
| 835 | packet_decrypt(&receive_context, cp, buffer_ptr(&input), |
| 836 | block_size); |
| 837 | ucp = (unsigned char *) buffer_ptr(&incoming_packet); |
| 838 | packet_length = GET_32BIT(ucp); |
| 839 | if (packet_length < 1 + 4 || packet_length > 256 * 1024) { |
| 840 | buffer_dump(&incoming_packet); |
| 841 | packet_disconnect("Bad packet length %d.", packet_length); |
| 842 | } |
| 843 | DBG(debug("input: packet len %d", packet_length+4)); |
| 844 | buffer_consume(&input, block_size); |
| 845 | } |
| 846 | /* we have a partial packet of block_size bytes */ |
| 847 | need = 4 + packet_length - block_size; |
| 848 | DBG(debug("partial packet %d, need %d, maclen %d", block_size, |
| 849 | need, maclen)); |
| 850 | if (need % block_size != 0) |
| 851 | fatal("padding error: need %d block %d mod %d", |
| 852 | need, block_size, need % block_size); |
| 853 | /* |
| 854 | * check if the entire packet has been received and |
| 855 | * decrypt into incoming_packet |
| 856 | */ |
| 857 | if (buffer_len(&input) < need + maclen) |
| 858 | return SSH_MSG_NONE; |
| 859 | #ifdef PACKET_DEBUG |
| 860 | fprintf(stderr, "read_poll enc/full: "); |
| 861 | buffer_dump(&input); |
| 862 | #endif |
| 863 | buffer_append_space(&incoming_packet, &cp, need); |
| 864 | packet_decrypt(&receive_context, cp, buffer_ptr(&input), need); |
| 865 | buffer_consume(&input, need); |
| 866 | /* |
| 867 | * compute MAC over seqnr and packet, |
| 868 | * increment sequence number for incoming packet |
| 869 | */ |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 870 | if (mac && mac->enabled) { |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 871 | macbuf = hmac( mac->md, seqnr, |
| 872 | (unsigned char *) buffer_ptr(&incoming_packet), |
| 873 | buffer_len(&incoming_packet), |
| 874 | mac->key, mac->key_len |
| 875 | ); |
| 876 | if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0) |
| 877 | packet_disconnect("Corrupted HMAC on input."); |
| 878 | DBG(debug("HMAC #%d ok", seqnr)); |
| 879 | buffer_consume(&input, mac->mac_len); |
| 880 | } |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 881 | if (++seqnr == 0) |
| 882 | log("incoming seqnr wraps around"); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 883 | |
| 884 | /* get padlen */ |
| 885 | cp = buffer_ptr(&incoming_packet) + 4; |
| 886 | padlen = *cp & 0xff; |
| 887 | DBG(debug("input: padlen %d", padlen)); |
| 888 | if (padlen < 4) |
| 889 | packet_disconnect("Corrupted padlen %d on input.", padlen); |
| 890 | |
| 891 | /* skip packet size + padlen, discard padding */ |
| 892 | buffer_consume(&incoming_packet, 4 + 1); |
| 893 | buffer_consume_end(&incoming_packet, padlen); |
| 894 | |
| 895 | DBG(debug("input: len before de-compress %d", buffer_len(&incoming_packet))); |
| 896 | if (comp && comp->enabled) { |
| 897 | buffer_clear(&compression_buffer); |
| 898 | buffer_uncompress(&incoming_packet, &compression_buffer); |
| 899 | buffer_clear(&incoming_packet); |
| 900 | buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), |
| 901 | buffer_len(&compression_buffer)); |
| 902 | DBG(debug("input: len after de-compress %d", buffer_len(&incoming_packet))); |
| 903 | } |
| 904 | /* |
| 905 | * get packet type, implies consume. |
| 906 | * return length of payload (without type field) |
| 907 | */ |
| 908 | buffer_get(&incoming_packet, (char *)&buf[0], 1); |
| 909 | *payload_len_ptr = buffer_len(&incoming_packet); |
| 910 | |
| 911 | /* reset for next packet */ |
| 912 | packet_length = 0; |
| 913 | |
| 914 | /* extract packet type */ |
| 915 | type = (unsigned char)buf[0]; |
| 916 | |
| 917 | if (type == SSH2_MSG_NEWKEYS) { |
| 918 | if (kex==NULL || mac==NULL || enc==NULL || comp==NULL) |
| 919 | fatal("packet_read_poll2: no KEX"); |
| 920 | if (mac->md != NULL) |
| 921 | mac->enabled = 1; |
Damien Miller | 35dabd0 | 2000-05-01 21:10:33 +1000 | [diff] [blame] | 922 | DBG(debug("cipher_set_key_iv receive_context")); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 923 | cipher_set_key_iv(&receive_context, enc->type, |
| 924 | enc->key, enc->key_len, |
| 925 | enc->iv, enc->iv_len); |
| 926 | clear_enc_keys(enc, kex->we_need); |
| 927 | if (comp->type != 0 && comp->enabled == 0) { |
| 928 | comp->enabled = 1; |
| 929 | if (! packet_compression) |
| 930 | packet_start_compression(6); |
| 931 | } |
| 932 | } |
| 933 | |
| 934 | #ifdef PACKET_DEBUG |
| 935 | fprintf(stderr, "read/plain[%d]:\r\n",type); |
| 936 | buffer_dump(&incoming_packet); |
| 937 | #endif |
| 938 | return (unsigned char)type; |
| 939 | } |
| 940 | |
| 941 | int |
| 942 | packet_read_poll(int *payload_len_ptr) |
| 943 | { |
| 944 | char *msg; |
| 945 | for (;;) { |
| 946 | int type = use_ssh2_packet_format ? |
| 947 | packet_read_poll2(payload_len_ptr): |
| 948 | packet_read_poll1(payload_len_ptr); |
| 949 | |
| 950 | if(compat20) { |
| 951 | int reason; |
| 952 | if (type != 0) |
| 953 | DBG(debug("received packet type %d", type)); |
| 954 | switch(type) { |
| 955 | case SSH2_MSG_IGNORE: |
| 956 | break; |
| 957 | case SSH2_MSG_DEBUG: |
| 958 | packet_get_char(); |
| 959 | msg = packet_get_string(NULL); |
| 960 | debug("Remote: %.900s", msg); |
| 961 | xfree(msg); |
| 962 | msg = packet_get_string(NULL); |
| 963 | xfree(msg); |
| 964 | break; |
| 965 | case SSH2_MSG_DISCONNECT: |
| 966 | reason = packet_get_int(); |
| 967 | msg = packet_get_string(NULL); |
| 968 | log("Received disconnect: %d: %.900s", reason, msg); |
| 969 | xfree(msg); |
| 970 | fatal_cleanup(); |
| 971 | break; |
| 972 | default: |
| 973 | return type; |
| 974 | break; |
| 975 | } |
| 976 | } else { |
| 977 | switch(type) { |
| 978 | case SSH_MSG_IGNORE: |
| 979 | break; |
| 980 | case SSH_MSG_DEBUG: |
| 981 | msg = packet_get_string(NULL); |
| 982 | debug("Remote: %.900s", msg); |
| 983 | xfree(msg); |
| 984 | break; |
| 985 | case SSH_MSG_DISCONNECT: |
| 986 | msg = packet_get_string(NULL); |
| 987 | log("Received disconnect: %.900s", msg); |
| 988 | fatal_cleanup(); |
| 989 | xfree(msg); |
| 990 | break; |
| 991 | default: |
| 992 | if (type != 0) |
| 993 | DBG(debug("received packet type %d", type)); |
| 994 | return type; |
| 995 | break; |
| 996 | } |
| 997 | } |
| 998 | } |
| 999 | } |
| 1000 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1001 | /* |
| 1002 | * Buffers the given amount of input characters. This is intended to be used |
| 1003 | * together with packet_read_poll. |
| 1004 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1005 | |
| 1006 | void |
| 1007 | packet_process_incoming(const char *buf, unsigned int len) |
| 1008 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1009 | buffer_append(&input, buf, len); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1010 | } |
| 1011 | |
| 1012 | /* Returns a character from the packet. */ |
| 1013 | |
| 1014 | unsigned int |
| 1015 | packet_get_char() |
| 1016 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1017 | char ch; |
| 1018 | buffer_get(&incoming_packet, &ch, 1); |
| 1019 | return (unsigned char) ch; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1020 | } |
| 1021 | |
| 1022 | /* Returns an integer from the packet data. */ |
| 1023 | |
| 1024 | unsigned int |
| 1025 | packet_get_int() |
| 1026 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1027 | return buffer_get_int(&incoming_packet); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1028 | } |
| 1029 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1030 | /* |
| 1031 | * Returns an arbitrary precision integer from the packet data. The integer |
| 1032 | * must have been initialized before this call. |
| 1033 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1034 | |
| 1035 | void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1036 | packet_get_bignum(BIGNUM * value, int *length_ptr) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1037 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1038 | *length_ptr = buffer_get_bignum(&incoming_packet, value); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1039 | } |
| 1040 | |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1041 | void |
| 1042 | packet_get_bignum2(BIGNUM * value, int *length_ptr) |
| 1043 | { |
| 1044 | *length_ptr = buffer_get_bignum2(&incoming_packet, value); |
| 1045 | } |
| 1046 | |
| 1047 | char * |
| 1048 | packet_get_raw(int *length_ptr) |
| 1049 | { |
| 1050 | int bytes = buffer_len(&incoming_packet); |
| 1051 | if (length_ptr != NULL) |
| 1052 | *length_ptr = bytes; |
| 1053 | return buffer_ptr(&incoming_packet); |
| 1054 | } |
| 1055 | |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 1056 | int |
| 1057 | packet_remaining(void) |
| 1058 | { |
| 1059 | return buffer_len(&incoming_packet); |
| 1060 | } |
| 1061 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1062 | /* |
| 1063 | * Returns a string from the packet data. The string is allocated using |
| 1064 | * xmalloc; it is the responsibility of the calling program to free it when |
| 1065 | * no longer needed. The length_ptr argument may be NULL, or point to an |
| 1066 | * integer into which the length of the string is stored. |
| 1067 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1068 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1069 | char * |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1070 | packet_get_string(unsigned int *length_ptr) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1071 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1072 | return buffer_get_string(&incoming_packet, length_ptr); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1073 | } |
| 1074 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1075 | /* |
| 1076 | * Sends a diagnostic message from the server to the client. This message |
| 1077 | * can be sent at any time (but not while constructing another message). The |
| 1078 | * message is printed immediately, but only if the client is being executed |
| 1079 | * in verbose mode. These messages are primarily intended to ease debugging |
| 1080 | * authentication problems. The length of the formatted message must not |
| 1081 | * exceed 1024 bytes. This will automatically call packet_write_wait. |
| 1082 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1083 | |
| 1084 | void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1085 | packet_send_debug(const char *fmt,...) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1086 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1087 | char buf[1024]; |
| 1088 | va_list args; |
| 1089 | |
| 1090 | va_start(args, fmt); |
| 1091 | vsnprintf(buf, sizeof(buf), fmt, args); |
| 1092 | va_end(args); |
| 1093 | |
Damien Miller | 7c8af4f | 2000-05-01 08:24:07 +1000 | [diff] [blame] | 1094 | if (compat20) { |
| 1095 | packet_start(SSH2_MSG_DEBUG); |
| 1096 | packet_put_char(0); /* bool: always display */ |
| 1097 | packet_put_cstring(buf); |
| 1098 | packet_put_cstring(""); |
| 1099 | } else { |
| 1100 | packet_start(SSH_MSG_DEBUG); |
| 1101 | packet_put_cstring(buf); |
| 1102 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1103 | packet_send(); |
| 1104 | packet_write_wait(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1105 | } |
| 1106 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1107 | /* |
| 1108 | * Logs the error plus constructs and sends a disconnect packet, closes the |
| 1109 | * connection, and exits. This function never returns. The error message |
| 1110 | * should not contain a newline. The length of the formatted message must |
| 1111 | * not exceed 1024 bytes. |
| 1112 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1113 | |
| 1114 | void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1115 | packet_disconnect(const char *fmt,...) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1116 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1117 | char buf[1024]; |
| 1118 | va_list args; |
| 1119 | static int disconnecting = 0; |
| 1120 | if (disconnecting) /* Guard against recursive invocations. */ |
| 1121 | fatal("packet_disconnect called recursively."); |
| 1122 | disconnecting = 1; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1123 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1124 | /* |
| 1125 | * Format the message. Note that the caller must make sure the |
| 1126 | * message is of limited size. |
| 1127 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1128 | va_start(args, fmt); |
| 1129 | vsnprintf(buf, sizeof(buf), fmt, args); |
| 1130 | va_end(args); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1131 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1132 | /* 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] | 1133 | if (compat20) { |
| 1134 | packet_start(SSH2_MSG_DISCONNECT); |
| 1135 | packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR); |
| 1136 | packet_put_cstring(buf); |
| 1137 | packet_put_cstring(""); |
| 1138 | } else { |
| 1139 | packet_start(SSH_MSG_DISCONNECT); |
| 1140 | packet_put_string(buf, strlen(buf)); |
| 1141 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1142 | packet_send(); |
| 1143 | packet_write_wait(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1144 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1145 | /* Stop listening for connections. */ |
| 1146 | channel_stop_listening(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1147 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1148 | /* Close the connection. */ |
| 1149 | packet_close(); |
| 1150 | |
| 1151 | /* Display the error locally and exit. */ |
Damien Miller | aae6c61 | 1999-12-06 11:47:28 +1100 | [diff] [blame] | 1152 | log("Disconnecting: %.100s", buf); |
| 1153 | fatal_cleanup(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1154 | } |
| 1155 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1156 | /* 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] | 1157 | |
| 1158 | void |
| 1159 | packet_write_poll() |
| 1160 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1161 | int len = buffer_len(&output); |
| 1162 | if (len > 0) { |
| 1163 | len = write(connection_out, buffer_ptr(&output), len); |
| 1164 | if (len <= 0) { |
| 1165 | if (errno == EAGAIN) |
| 1166 | return; |
| 1167 | else |
| 1168 | fatal("Write failed: %.100s", strerror(errno)); |
| 1169 | } |
| 1170 | buffer_consume(&output, len); |
| 1171 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1172 | } |
| 1173 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1174 | /* |
| 1175 | * Calls packet_write_poll repeatedly until all pending output data has been |
| 1176 | * written. |
| 1177 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1178 | |
| 1179 | void |
| 1180 | packet_write_wait() |
| 1181 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1182 | packet_write_poll(); |
| 1183 | while (packet_have_data_to_write()) { |
| 1184 | fd_set set; |
| 1185 | FD_ZERO(&set); |
| 1186 | FD_SET(connection_out, &set); |
| 1187 | select(connection_out + 1, NULL, &set, NULL, NULL); |
| 1188 | packet_write_poll(); |
| 1189 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1190 | } |
| 1191 | |
| 1192 | /* Returns true if there is buffered data to write to the connection. */ |
| 1193 | |
| 1194 | int |
| 1195 | packet_have_data_to_write() |
| 1196 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1197 | return buffer_len(&output) != 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1198 | } |
| 1199 | |
| 1200 | /* Returns true if there is not too much data to write to the connection. */ |
| 1201 | |
| 1202 | int |
| 1203 | packet_not_very_much_data_to_write() |
| 1204 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1205 | if (interactive_mode) |
| 1206 | return buffer_len(&output) < 16384; |
| 1207 | else |
| 1208 | return buffer_len(&output) < 128 * 1024; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1209 | } |
| 1210 | |
| 1211 | /* Informs that the current session is interactive. Sets IP flags for that. */ |
| 1212 | |
| 1213 | void |
| 1214 | packet_set_interactive(int interactive, int keepalives) |
| 1215 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1216 | int on = 1; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1217 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1218 | /* Record that we are in interactive mode. */ |
| 1219 | interactive_mode = interactive; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1220 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1221 | /* Only set socket options if using a socket. */ |
| 1222 | if (!packet_connection_is_on_socket()) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1223 | return; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1224 | if (keepalives) { |
| 1225 | /* Set keepalives if requested. */ |
| 1226 | if (setsockopt(connection_in, SOL_SOCKET, SO_KEEPALIVE, (void *) &on, |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1227 | sizeof(on)) < 0) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1228 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); |
| 1229 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1230 | /* |
| 1231 | * IPTOS_LOWDELAY, TCP_NODELAY and IPTOS_THROUGHPUT are IPv4 only |
| 1232 | */ |
| 1233 | if (!packet_connection_is_ipv4()) |
| 1234 | return; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1235 | if (interactive) { |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1236 | /* |
| 1237 | * Set IP options for an interactive connection. Use |
| 1238 | * IPTOS_LOWDELAY and TCP_NODELAY. |
| 1239 | */ |
Damien Miller | 615f939 | 2000-05-17 22:53:33 +1000 | [diff] [blame] | 1240 | #ifdef IP_TOS |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1241 | int lowdelay = IPTOS_LOWDELAY; |
| 1242 | if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &lowdelay, |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1243 | sizeof(lowdelay)) < 0) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1244 | error("setsockopt IPTOS_LOWDELAY: %.100s", strerror(errno)); |
Damien Miller | 615f939 | 2000-05-17 22:53:33 +1000 | [diff] [blame] | 1245 | #endif |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1246 | if (setsockopt(connection_in, IPPROTO_TCP, TCP_NODELAY, (void *) &on, |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1247 | sizeof(on)) < 0) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1248 | error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); |
| 1249 | } else { |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1250 | /* |
| 1251 | * Set IP options for a non-interactive connection. Use |
| 1252 | * IPTOS_THROUGHPUT. |
| 1253 | */ |
Damien Miller | 615f939 | 2000-05-17 22:53:33 +1000 | [diff] [blame] | 1254 | #ifdef IP_TOS |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1255 | int throughput = IPTOS_THROUGHPUT; |
| 1256 | if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &throughput, |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1257 | sizeof(throughput)) < 0) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1258 | error("setsockopt IPTOS_THROUGHPUT: %.100s", strerror(errno)); |
Damien Miller | 615f939 | 2000-05-17 22:53:33 +1000 | [diff] [blame] | 1259 | #endif |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1260 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1261 | } |
| 1262 | |
| 1263 | /* Returns true if the current connection is interactive. */ |
| 1264 | |
| 1265 | int |
| 1266 | packet_is_interactive() |
| 1267 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1268 | return interactive_mode; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1269 | } |
Damien Miller | 6162d12 | 1999-11-21 13:23:52 +1100 | [diff] [blame] | 1270 | |
| 1271 | int |
| 1272 | packet_set_maxsize(int s) |
| 1273 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1274 | static int called = 0; |
| 1275 | if (called) { |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 1276 | log("packet_set_maxsize: called twice: old %d new %d", |
| 1277 | max_packet_size, s); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1278 | return -1; |
| 1279 | } |
| 1280 | if (s < 4 * 1024 || s > 1024 * 1024) { |
| 1281 | log("packet_set_maxsize: bad size %d", s); |
| 1282 | return -1; |
| 1283 | } |
| 1284 | log("packet_set_maxsize: setting to %d", s); |
| 1285 | max_packet_size = s; |
| 1286 | return s; |
Damien Miller | 6162d12 | 1999-11-21 13:23:52 +1100 | [diff] [blame] | 1287 | } |