Annotation of src/usr.bin/ssh/packet.c, Revision 1.185
1.185 ! dtucker 1: /* $OpenBSD: packet.c,v 1.184 2013/05/16 02:00:34 dtucker Exp $ */
1.1 deraadt 2: /*
1.15 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.35 deraadt 6: * This file contains code implementing the packet protocol and communication
7: * with the other side. This same code is used both on client and server side.
1.29 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
1.29 markus 14: *
1.25 markus 15: *
16: * SSH2 packet format added by Markus Friedl.
1.69 markus 17: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.25 markus 18: *
1.35 deraadt 19: * Redistribution and use in source and binary forms, with or without
20: * modification, are permitted provided that the following conditions
21: * are met:
22: * 1. Redistributions of source code must retain the above copyright
23: * notice, this list of conditions and the following disclaimer.
24: * 2. Redistributions in binary form must reproduce the above copyright
25: * notice, this list of conditions and the following disclaimer in the
26: * documentation and/or other materials provided with the distribution.
27: *
28: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15 deraadt 38: */
1.1 deraadt 39:
1.142 deraadt 40: #include <sys/types.h>
1.105 markus 41: #include <sys/queue.h>
1.132 stevesk 42: #include <sys/socket.h>
1.138 stevesk 43: #include <sys/time.h>
1.139 stevesk 44: #include <sys/param.h>
1.121 stevesk 45:
46: #include <netinet/in_systm.h>
1.132 stevesk 47: #include <netinet/in.h>
1.121 stevesk 48: #include <netinet/ip.h>
1.134 stevesk 49:
1.135 stevesk 50: #include <errno.h>
1.134 stevesk 51: #include <stdarg.h>
1.141 stevesk 52: #include <stdio.h>
1.140 stevesk 53: #include <stdlib.h>
1.137 stevesk 54: #include <string.h>
1.136 stevesk 55: #include <unistd.h>
1.142 deraadt 56: #include <signal.h>
1.184 dtucker 57: #include <time.h>
1.1 deraadt 58:
59: #include "xmalloc.h"
60: #include "buffer.h"
61: #include "packet.h"
62: #include "crc32.h"
63: #include "compress.h"
1.9 dugsong 64: #include "deattack.h"
1.64 markus 65: #include "channels.h"
1.25 markus 66: #include "compat.h"
1.45 markus 67: #include "ssh1.h"
1.25 markus 68: #include "ssh2.h"
1.37 markus 69: #include "cipher.h"
1.142 deraadt 70: #include "key.h"
1.25 markus 71: #include "kex.h"
1.50 markus 72: #include "mac.h"
1.46 markus 73: #include "log.h"
74: #include "canohost.h"
1.87 stevesk 75: #include "misc.h"
1.95 markus 76: #include "ssh.h"
1.163 andreas 77: #include "roaming.h"
1.25 markus 78:
79: #ifdef PACKET_DEBUG
80: #define DBG(x) x
81: #else
82: #define DBG(x)
83: #endif
84:
1.159 markus 85: #define PACKET_MAX_SIZE (256 * 1024)
86:
1.161 andreas 87: struct packet_state {
88: u_int32_t seqnr;
89: u_int32_t packets;
90: u_int64_t blocks;
91: u_int64_t bytes;
92: };
93:
94: struct packet {
95: TAILQ_ENTRY(packet) next;
96: u_char type;
97: Buffer payload;
98: };
99:
100: struct session_state {
101: /*
102: * This variable contains the file descriptors used for
103: * communicating with the other side. connection_in is used for
104: * reading; connection_out for writing. These can be the same
105: * descriptor, in which case it is assumed to be a socket.
106: */
107: int connection_in;
108: int connection_out;
109:
110: /* Protocol flags for the remote side. */
111: u_int remote_protocol_flags;
1.1 deraadt 112:
1.161 andreas 113: /* Encryption context for receiving data. Only used for decryption. */
114: CipherContext receive_context;
1.1 deraadt 115:
1.161 andreas 116: /* Encryption context for sending data. Only used for encryption. */
117: CipherContext send_context;
1.14 markus 118:
1.161 andreas 119: /* Buffer for raw input data from the socket. */
120: Buffer input;
1.1 deraadt 121:
1.161 andreas 122: /* Buffer for raw output data going to the socket. */
123: Buffer output;
1.1 deraadt 124:
1.161 andreas 125: /* Buffer for the partial outgoing packet being constructed. */
126: Buffer outgoing_packet;
1.1 deraadt 127:
1.161 andreas 128: /* Buffer for the incoming packet currently being processed. */
129: Buffer incoming_packet;
1.1 deraadt 130:
1.161 andreas 131: /* Scratch buffer for packet compression/decompression. */
132: Buffer compression_buffer;
133: int compression_buffer_ready;
1.1 deraadt 134:
1.161 andreas 135: /*
136: * Flag indicating whether packet compression/decompression is
137: * enabled.
138: */
139: int packet_compression;
1.1 deraadt 140:
1.161 andreas 141: /* default maximum packet size */
142: u_int max_packet_size;
1.1 deraadt 143:
1.161 andreas 144: /* Flag indicating whether this module has been initialized. */
145: int initialized;
1.12 markus 146:
1.161 andreas 147: /* Set to true if the connection is interactive. */
148: int interactive_mode;
1.1 deraadt 149:
1.161 andreas 150: /* Set to true if we are the server side. */
151: int server_side;
1.1 deraadt 152:
1.161 andreas 153: /* Set to true if we are authenticated. */
154: int after_authentication;
1.118 markus 155:
1.161 andreas 156: int keep_alive_timeouts;
1.118 markus 157:
1.161 andreas 158: /* The maximum time that we will wait to send or receive a packet */
159: int packet_timeout_ms;
1.151 dtucker 160:
1.161 andreas 161: /* Session key information for Encryption and MAC */
162: Newkeys *newkeys[MODE_MAX];
163: struct packet_state p_read, p_send;
1.154 dtucker 164:
1.184 dtucker 165: /* Volume-based rekeying */
1.161 andreas 166: u_int64_t max_blocks_in, max_blocks_out;
167: u_int32_t rekey_limit;
1.105 markus 168:
1.184 dtucker 169: /* Time-based rekeying */
170: time_t rekey_interval; /* how often in seconds */
171: time_t rekey_time; /* time of last rekeying */
172:
1.161 andreas 173: /* Session key for protocol v1 */
174: u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
175: u_int ssh1_keylen;
1.25 markus 176:
1.161 andreas 177: /* roundup current message to extra_pad bytes */
178: u_char extra_pad;
1.95 markus 179:
1.161 andreas 180: /* XXX discard incoming data after MAC error */
181: u_int packet_discard;
182: Mac *packet_discard_mac;
1.71 markus 183:
1.161 andreas 184: /* Used in packet_read_poll2() */
185: u_int packlen;
1.159 markus 186:
1.165 andreas 187: /* Used in packet_send2 */
188: int rekeying;
189:
190: /* Used in packet_set_interactive */
191: int set_interactive_called;
192:
193: /* Used in packet_set_maxsize */
194: int set_maxsize_called;
195:
1.161 andreas 196: TAILQ_HEAD(, packet) outgoing;
1.105 markus 197: };
1.161 andreas 198:
1.166 andreas 199: static struct session_state *active_state, *backup_state;
1.161 andreas 200:
201: static struct session_state *
1.164 andreas 202: alloc_session_state(void)
1.161 andreas 203: {
1.171 djm 204: struct session_state *s = xcalloc(1, sizeof(*s));
1.161 andreas 205:
1.171 djm 206: s->connection_in = -1;
207: s->connection_out = -1;
208: s->max_packet_size = 32768;
209: s->packet_timeout_ms = -1;
210: return s;
1.161 andreas 211: }
1.105 markus 212:
1.16 markus 213: /*
214: * Sets the descriptors used for communication. Disables encryption until
215: * packet_set_encryption_key is called.
216: */
1.2 provos 217: void
218: packet_set_connection(int fd_in, int fd_out)
1.1 deraadt 219: {
1.183 djm 220: const Cipher *none = cipher_by_name("none");
1.97 deraadt 221:
1.37 markus 222: if (none == NULL)
223: fatal("packet_set_connection: cannot load cipher 'none'");
1.161 andreas 224: if (active_state == NULL)
225: active_state = alloc_session_state();
226: active_state->connection_in = fd_in;
227: active_state->connection_out = fd_out;
228: cipher_init(&active_state->send_context, none, (const u_char *)"",
1.113 deraadt 229: 0, NULL, 0, CIPHER_ENCRYPT);
1.161 andreas 230: cipher_init(&active_state->receive_context, none, (const u_char *)"",
1.113 deraadt 231: 0, NULL, 0, CIPHER_DECRYPT);
1.161 andreas 232: active_state->newkeys[MODE_IN] = active_state->newkeys[MODE_OUT] = NULL;
233: if (!active_state->initialized) {
234: active_state->initialized = 1;
235: buffer_init(&active_state->input);
236: buffer_init(&active_state->output);
237: buffer_init(&active_state->outgoing_packet);
238: buffer_init(&active_state->incoming_packet);
239: TAILQ_INIT(&active_state->outgoing);
240: active_state->p_send.packets = active_state->p_read.packets = 0;
1.14 markus 241: }
1.1 deraadt 242: }
243:
1.154 dtucker 244: void
245: packet_set_timeout(int timeout, int count)
246: {
1.174 djm 247: if (timeout <= 0 || count <= 0) {
1.161 andreas 248: active_state->packet_timeout_ms = -1;
1.154 dtucker 249: return;
250: }
251: if ((INT_MAX / 1000) / count < timeout)
1.161 andreas 252: active_state->packet_timeout_ms = INT_MAX;
1.154 dtucker 253: else
1.161 andreas 254: active_state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 255: }
256:
1.159 markus 257: static void
258: packet_stop_discard(void)
259: {
1.161 andreas 260: if (active_state->packet_discard_mac) {
1.159 markus 261: char buf[1024];
262:
263: memset(buf, 'a', sizeof(buf));
1.161 andreas 264: while (buffer_len(&active_state->incoming_packet) <
265: PACKET_MAX_SIZE)
266: buffer_append(&active_state->incoming_packet, buf,
267: sizeof(buf));
268: (void) mac_compute(active_state->packet_discard_mac,
269: active_state->p_read.seqnr,
270: buffer_ptr(&active_state->incoming_packet),
1.159 markus 271: PACKET_MAX_SIZE);
272: }
273: logit("Finished discarding for %.200s", get_remote_ipaddr());
274: cleanup_exit(255);
275: }
276:
277: static void
278: packet_start_discard(Enc *enc, Mac *mac, u_int packet_length, u_int discard)
279: {
1.178 markus 280: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm))
1.159 markus 281: packet_disconnect("Packet corrupt");
282: if (packet_length != PACKET_MAX_SIZE && mac && mac->enabled)
1.161 andreas 283: active_state->packet_discard_mac = mac;
284: if (buffer_len(&active_state->input) >= discard)
1.159 markus 285: packet_stop_discard();
1.161 andreas 286: active_state->packet_discard = discard -
287: buffer_len(&active_state->input);
1.159 markus 288: }
289:
1.19 markus 290: /* Returns 1 if remote host is connected via socket, 0 if not. */
291:
292: int
1.73 itojun 293: packet_connection_is_on_socket(void)
1.19 markus 294: {
295: struct sockaddr_storage from, to;
296: socklen_t fromlen, tolen;
297:
298: /* filedescriptors in and out are the same, so it's a socket */
1.161 andreas 299: if (active_state->connection_in == active_state->connection_out)
1.19 markus 300: return 1;
301: fromlen = sizeof(from);
302: memset(&from, 0, sizeof(from));
1.161 andreas 303: if (getpeername(active_state->connection_in, (struct sockaddr *)&from,
304: &fromlen) < 0)
1.19 markus 305: return 0;
306: tolen = sizeof(to);
307: memset(&to, 0, sizeof(to));
1.161 andreas 308: if (getpeername(active_state->connection_out, (struct sockaddr *)&to,
309: &tolen) < 0)
1.19 markus 310: return 0;
311: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
312: return 0;
313: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
314: return 0;
315: return 1;
316: }
317:
1.92 markus 318: /*
1.91 markus 319: * Exports an IV from the CipherContext required to export the key
320: * state back from the unprivileged child to the privileged parent
321: * process.
322: */
323:
324: void
325: packet_get_keyiv(int mode, u_char *iv, u_int len)
326: {
327: CipherContext *cc;
328:
329: if (mode == MODE_OUT)
1.161 andreas 330: cc = &active_state->send_context;
1.91 markus 331: else
1.161 andreas 332: cc = &active_state->receive_context;
1.91 markus 333:
334: cipher_get_keyiv(cc, iv, len);
335: }
336:
337: int
338: packet_get_keycontext(int mode, u_char *dat)
339: {
340: CipherContext *cc;
1.92 markus 341:
1.91 markus 342: if (mode == MODE_OUT)
1.161 andreas 343: cc = &active_state->send_context;
1.91 markus 344: else
1.161 andreas 345: cc = &active_state->receive_context;
1.91 markus 346:
347: return (cipher_get_keycontext(cc, dat));
348: }
349:
350: void
351: packet_set_keycontext(int mode, u_char *dat)
352: {
353: CipherContext *cc;
1.92 markus 354:
1.91 markus 355: if (mode == MODE_OUT)
1.161 andreas 356: cc = &active_state->send_context;
1.91 markus 357: else
1.161 andreas 358: cc = &active_state->receive_context;
1.91 markus 359:
360: cipher_set_keycontext(cc, dat);
361: }
362:
363: int
364: packet_get_keyiv_len(int mode)
365: {
366: CipherContext *cc;
367:
368: if (mode == MODE_OUT)
1.161 andreas 369: cc = &active_state->send_context;
1.91 markus 370: else
1.161 andreas 371: cc = &active_state->receive_context;
1.91 markus 372:
373: return (cipher_get_keyiv_len(cc));
374: }
1.125 deraadt 375:
1.91 markus 376: void
377: packet_set_iv(int mode, u_char *dat)
378: {
379: CipherContext *cc;
380:
381: if (mode == MODE_OUT)
1.161 andreas 382: cc = &active_state->send_context;
1.91 markus 383: else
1.161 andreas 384: cc = &active_state->receive_context;
1.91 markus 385:
386: cipher_set_keyiv(cc, dat);
387: }
1.125 deraadt 388:
1.91 markus 389: int
1.107 deraadt 390: packet_get_ssh1_cipher(void)
1.91 markus 391: {
1.161 andreas 392: return (cipher_get_number(active_state->receive_context.cipher));
1.91 markus 393: }
394:
1.105 markus 395: void
1.171 djm 396: packet_get_state(int mode, u_int32_t *seqnr, u_int64_t *blocks,
397: u_int32_t *packets, u_int64_t *bytes)
1.105 markus 398: {
399: struct packet_state *state;
1.104 markus 400:
1.161 andreas 401: state = (mode == MODE_IN) ?
402: &active_state->p_read : &active_state->p_send;
1.157 markus 403: if (seqnr)
404: *seqnr = state->seqnr;
405: if (blocks)
406: *blocks = state->blocks;
407: if (packets)
408: *packets = state->packets;
409: if (bytes)
410: *bytes = state->bytes;
1.91 markus 411: }
412:
413: void
1.157 markus 414: packet_set_state(int mode, u_int32_t seqnr, u_int64_t blocks, u_int32_t packets,
415: u_int64_t bytes)
1.91 markus 416: {
1.105 markus 417: struct packet_state *state;
418:
1.161 andreas 419: state = (mode == MODE_IN) ?
420: &active_state->p_read : &active_state->p_send;
1.105 markus 421: state->seqnr = seqnr;
422: state->blocks = blocks;
423: state->packets = packets;
1.157 markus 424: state->bytes = bytes;
1.91 markus 425: }
426:
1.173 djm 427: static int
428: packet_connection_af(void)
1.19 markus 429: {
430: struct sockaddr_storage to;
1.21 deraadt 431: socklen_t tolen = sizeof(to);
1.19 markus 432:
433: memset(&to, 0, sizeof(to));
1.161 andreas 434: if (getsockname(active_state->connection_out, (struct sockaddr *)&to,
435: &tolen) < 0)
1.19 markus 436: return 0;
1.173 djm 437: return to.ss_family;
1.19 markus 438: }
439:
1.1 deraadt 440: /* Sets the connection into non-blocking mode. */
441:
1.2 provos 442: void
1.73 itojun 443: packet_set_nonblocking(void)
1.1 deraadt 444: {
1.14 markus 445: /* Set the socket into non-blocking mode. */
1.161 andreas 446: set_nonblock(active_state->connection_in);
1.14 markus 447:
1.161 andreas 448: if (active_state->connection_out != active_state->connection_in)
449: set_nonblock(active_state->connection_out);
1.1 deraadt 450: }
451:
452: /* Returns the socket used for reading. */
453:
1.2 provos 454: int
1.73 itojun 455: packet_get_connection_in(void)
1.1 deraadt 456: {
1.161 andreas 457: return active_state->connection_in;
1.1 deraadt 458: }
459:
460: /* Returns the descriptor used for writing. */
461:
1.2 provos 462: int
1.73 itojun 463: packet_get_connection_out(void)
1.1 deraadt 464: {
1.161 andreas 465: return active_state->connection_out;
1.1 deraadt 466: }
467:
468: /* Closes the connection and clears and frees internal data structures. */
469:
1.2 provos 470: void
1.73 itojun 471: packet_close(void)
1.1 deraadt 472: {
1.161 andreas 473: if (!active_state->initialized)
1.14 markus 474: return;
1.161 andreas 475: active_state->initialized = 0;
476: if (active_state->connection_in == active_state->connection_out) {
477: shutdown(active_state->connection_out, SHUT_RDWR);
478: close(active_state->connection_out);
1.14 markus 479: } else {
1.161 andreas 480: close(active_state->connection_in);
481: close(active_state->connection_out);
1.14 markus 482: }
1.161 andreas 483: buffer_free(&active_state->input);
484: buffer_free(&active_state->output);
485: buffer_free(&active_state->outgoing_packet);
486: buffer_free(&active_state->incoming_packet);
487: if (active_state->compression_buffer_ready) {
488: buffer_free(&active_state->compression_buffer);
1.14 markus 489: buffer_compress_uninit();
490: }
1.161 andreas 491: cipher_cleanup(&active_state->send_context);
492: cipher_cleanup(&active_state->receive_context);
1.1 deraadt 493: }
494:
495: /* Sets remote side protocol flags. */
496:
1.2 provos 497: void
1.40 markus 498: packet_set_protocol_flags(u_int protocol_flags)
1.1 deraadt 499: {
1.161 andreas 500: active_state->remote_protocol_flags = protocol_flags;
1.1 deraadt 501: }
502:
503: /* Returns the remote protocol flags set earlier by the above function. */
504:
1.40 markus 505: u_int
1.73 itojun 506: packet_get_protocol_flags(void)
1.1 deraadt 507: {
1.161 andreas 508: return active_state->remote_protocol_flags;
1.1 deraadt 509: }
510:
1.16 markus 511: /*
512: * Starts packet compression from the next packet on in both directions.
513: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
514: */
1.1 deraadt 515:
1.68 itojun 516: static void
517: packet_init_compression(void)
1.60 markus 518: {
1.161 andreas 519: if (active_state->compression_buffer_ready == 1)
1.60 markus 520: return;
1.161 andreas 521: active_state->compression_buffer_ready = 1;
522: buffer_init(&active_state->compression_buffer);
1.60 markus 523: }
524:
1.2 provos 525: void
526: packet_start_compression(int level)
1.1 deraadt 527: {
1.161 andreas 528: if (active_state->packet_compression && !compat20)
1.14 markus 529: fatal("Compression already enabled.");
1.161 andreas 530: active_state->packet_compression = 1;
1.60 markus 531: packet_init_compression();
532: buffer_compress_init_send(level);
533: buffer_compress_init_recv();
1.1 deraadt 534: }
535:
1.16 markus 536: /*
537: * Causes any further packets to be encrypted using the given key. The same
538: * key is used for both sending and reception. However, both directions are
539: * encrypted independently of each other.
540: */
1.95 markus 541:
1.2 provos 542: void
1.171 djm 543: packet_set_encryption_key(const u_char *key, u_int keylen, int number)
1.1 deraadt 544: {
1.183 djm 545: const Cipher *cipher = cipher_by_number(number);
1.97 deraadt 546:
1.37 markus 547: if (cipher == NULL)
548: fatal("packet_set_encryption_key: unknown cipher number %d", number);
1.25 markus 549: if (keylen < 20)
1.37 markus 550: fatal("packet_set_encryption_key: keylen too small: %d", keylen);
1.95 markus 551: if (keylen > SSH_SESSION_KEY_LENGTH)
552: fatal("packet_set_encryption_key: keylen too big: %d", keylen);
1.161 andreas 553: memcpy(active_state->ssh1_key, key, keylen);
554: active_state->ssh1_keylen = keylen;
555: cipher_init(&active_state->send_context, cipher, key, keylen, NULL,
556: 0, CIPHER_ENCRYPT);
557: cipher_init(&active_state->receive_context, cipher, key, keylen, NULL,
558: 0, CIPHER_DECRYPT);
1.95 markus 559: }
560:
561: u_int
562: packet_get_encryption_key(u_char *key)
563: {
564: if (key == NULL)
1.161 andreas 565: return (active_state->ssh1_keylen);
566: memcpy(key, active_state->ssh1_key, active_state->ssh1_keylen);
567: return (active_state->ssh1_keylen);
1.1 deraadt 568: }
569:
1.62 markus 570: /* Start constructing a packet to send. */
1.2 provos 571: void
1.62 markus 572: packet_start(u_char type)
1.1 deraadt 573: {
1.62 markus 574: u_char buf[9];
575: int len;
1.1 deraadt 576:
1.62 markus 577: DBG(debug("packet_start[%d]", type));
578: len = compat20 ? 6 : 9;
579: memset(buf, 0, len - 1);
580: buf[len - 1] = type;
1.161 andreas 581: buffer_clear(&active_state->outgoing_packet);
582: buffer_append(&active_state->outgoing_packet, buf, len);
1.25 markus 583: }
584:
1.62 markus 585: /* Append payload. */
1.2 provos 586: void
587: packet_put_char(int value)
1.1 deraadt 588: {
1.14 markus 589: char ch = value;
1.97 deraadt 590:
1.161 andreas 591: buffer_append(&active_state->outgoing_packet, &ch, 1);
1.1 deraadt 592: }
1.125 deraadt 593:
1.2 provos 594: void
1.40 markus 595: packet_put_int(u_int value)
1.1 deraadt 596: {
1.161 andreas 597: buffer_put_int(&active_state->outgoing_packet, value);
1.1 deraadt 598: }
1.125 deraadt 599:
1.2 provos 600: void
1.162 andreas 601: packet_put_int64(u_int64_t value)
602: {
603: buffer_put_int64(&active_state->outgoing_packet, value);
604: }
605:
606: void
1.76 stevesk 607: packet_put_string(const void *buf, u_int len)
1.1 deraadt 608: {
1.161 andreas 609: buffer_put_string(&active_state->outgoing_packet, buf, len);
1.1 deraadt 610: }
1.125 deraadt 611:
1.24 markus 612: void
613: packet_put_cstring(const char *str)
614: {
1.161 andreas 615: buffer_put_cstring(&active_state->outgoing_packet, str);
1.24 markus 616: }
1.125 deraadt 617:
1.24 markus 618: void
1.76 stevesk 619: packet_put_raw(const void *buf, u_int len)
1.24 markus 620: {
1.161 andreas 621: buffer_append(&active_state->outgoing_packet, buf, len);
1.24 markus 622: }
1.125 deraadt 623:
1.2 provos 624: void
1.14 markus 625: packet_put_bignum(BIGNUM * value)
1.1 deraadt 626: {
1.161 andreas 627: buffer_put_bignum(&active_state->outgoing_packet, value);
1.1 deraadt 628: }
1.125 deraadt 629:
1.24 markus 630: void
631: packet_put_bignum2(BIGNUM * value)
632: {
1.161 andreas 633: buffer_put_bignum2(&active_state->outgoing_packet, value);
1.24 markus 634: }
1.1 deraadt 635:
1.170 djm 636: void
637: packet_put_ecpoint(const EC_GROUP *curve, const EC_POINT *point)
638: {
639: buffer_put_ecpoint(&active_state->outgoing_packet, curve, point);
640: }
641:
1.16 markus 642: /*
643: * Finalizes and sends the packet. If the encryption key has been set,
644: * encrypts the packet before sending.
645: */
1.14 markus 646:
1.68 itojun 647: static void
1.49 itojun 648: packet_send1(void)
1.1 deraadt 649: {
1.89 markus 650: u_char buf[8], *cp;
1.14 markus 651: int i, padding, len;
1.40 markus 652: u_int checksum;
1.115 avsm 653: u_int32_t rnd = 0;
1.14 markus 654:
1.16 markus 655: /*
656: * If using packet compression, compress the payload of the outgoing
657: * packet.
658: */
1.161 andreas 659: if (active_state->packet_compression) {
660: buffer_clear(&active_state->compression_buffer);
1.14 markus 661: /* Skip padding. */
1.161 andreas 662: buffer_consume(&active_state->outgoing_packet, 8);
1.14 markus 663: /* padding */
1.161 andreas 664: buffer_append(&active_state->compression_buffer,
665: "\0\0\0\0\0\0\0\0", 8);
666: buffer_compress(&active_state->outgoing_packet,
667: &active_state->compression_buffer);
668: buffer_clear(&active_state->outgoing_packet);
669: buffer_append(&active_state->outgoing_packet,
670: buffer_ptr(&active_state->compression_buffer),
671: buffer_len(&active_state->compression_buffer));
1.14 markus 672: }
673: /* Compute packet length without padding (add checksum, remove padding). */
1.161 andreas 674: len = buffer_len(&active_state->outgoing_packet) + 4 - 8;
1.14 markus 675:
1.32 markus 676: /* Insert padding. Initialized to zero in packet_start1() */
1.14 markus 677: padding = 8 - len % 8;
1.161 andreas 678: if (!active_state->send_context.plaintext) {
679: cp = buffer_ptr(&active_state->outgoing_packet);
1.14 markus 680: for (i = 0; i < padding; i++) {
681: if (i % 4 == 0)
1.115 avsm 682: rnd = arc4random();
683: cp[7 - i] = rnd & 0xff;
684: rnd >>= 8;
1.14 markus 685: }
686: }
1.161 andreas 687: buffer_consume(&active_state->outgoing_packet, 8 - padding);
1.14 markus 688:
689: /* Add check bytes. */
1.161 andreas 690: checksum = ssh_crc32(buffer_ptr(&active_state->outgoing_packet),
691: buffer_len(&active_state->outgoing_packet));
1.131 djm 692: put_u32(buf, checksum);
1.161 andreas 693: buffer_append(&active_state->outgoing_packet, buf, 4);
1.1 deraadt 694:
695: #ifdef PACKET_DEBUG
1.14 markus 696: fprintf(stderr, "packet_send plain: ");
1.161 andreas 697: buffer_dump(&active_state->outgoing_packet);
1.1 deraadt 698: #endif
699:
1.14 markus 700: /* Append to output. */
1.131 djm 701: put_u32(buf, len);
1.161 andreas 702: buffer_append(&active_state->output, buf, 4);
703: cp = buffer_append_space(&active_state->output,
704: buffer_len(&active_state->outgoing_packet));
705: cipher_crypt(&active_state->send_context, cp,
706: buffer_ptr(&active_state->outgoing_packet),
1.180 markus 707: buffer_len(&active_state->outgoing_packet), 0, 0);
1.14 markus 708:
1.1 deraadt 709: #ifdef PACKET_DEBUG
1.14 markus 710: fprintf(stderr, "encrypted: ");
1.161 andreas 711: buffer_dump(&active_state->output);
1.1 deraadt 712: #endif
1.161 andreas 713: active_state->p_send.packets++;
714: active_state->p_send.bytes += len +
715: buffer_len(&active_state->outgoing_packet);
716: buffer_clear(&active_state->outgoing_packet);
1.1 deraadt 717:
1.16 markus 718: /*
1.120 djm 719: * Note that the packet is now only buffered in output. It won't be
1.16 markus 720: * actually sent until packet_write_wait or packet_write_poll is
721: * called.
722: */
1.1 deraadt 723: }
724:
1.91 markus 725: void
1.57 markus 726: set_newkeys(int mode)
727: {
728: Enc *enc;
729: Mac *mac;
730: Comp *comp;
731: CipherContext *cc;
1.105 markus 732: u_int64_t *max_blocks;
1.115 avsm 733: int crypt_type;
1.57 markus 734:
1.100 markus 735: debug2("set_newkeys: mode %d", mode);
1.57 markus 736:
1.88 markus 737: if (mode == MODE_OUT) {
1.161 andreas 738: cc = &active_state->send_context;
1.115 avsm 739: crypt_type = CIPHER_ENCRYPT;
1.161 andreas 740: active_state->p_send.packets = active_state->p_send.blocks = 0;
741: max_blocks = &active_state->max_blocks_out;
1.88 markus 742: } else {
1.161 andreas 743: cc = &active_state->receive_context;
1.115 avsm 744: crypt_type = CIPHER_DECRYPT;
1.161 andreas 745: active_state->p_read.packets = active_state->p_read.blocks = 0;
746: max_blocks = &active_state->max_blocks_in;
1.88 markus 747: }
1.161 andreas 748: if (active_state->newkeys[mode] != NULL) {
1.100 markus 749: debug("set_newkeys: rekeying");
1.88 markus 750: cipher_cleanup(cc);
1.161 andreas 751: enc = &active_state->newkeys[mode]->enc;
752: mac = &active_state->newkeys[mode]->mac;
753: comp = &active_state->newkeys[mode]->comp;
1.148 pvalchev 754: mac_clear(mac);
1.180 markus 755: memset(enc->iv, 0, enc->iv_len);
1.177 markus 756: memset(enc->key, 0, enc->key_len);
757: memset(mac->key, 0, mac->key_len);
1.59 markus 758: xfree(enc->name);
759: xfree(enc->iv);
760: xfree(enc->key);
761: xfree(mac->name);
762: xfree(mac->key);
763: xfree(comp->name);
1.161 andreas 764: xfree(active_state->newkeys[mode]);
1.57 markus 765: }
1.161 andreas 766: active_state->newkeys[mode] = kex_get_newkeys(mode);
767: if (active_state->newkeys[mode] == NULL)
1.57 markus 768: fatal("newkeys: no keys for mode %d", mode);
1.161 andreas 769: enc = &active_state->newkeys[mode]->enc;
770: mac = &active_state->newkeys[mode]->mac;
771: comp = &active_state->newkeys[mode]->comp;
1.180 markus 772: if (cipher_authlen(enc->cipher) == 0 && mac_init(mac) == 0)
1.57 markus 773: mac->enabled = 1;
774: DBG(debug("cipher_init_context: %d", mode));
1.88 markus 775: cipher_init(cc, enc->cipher, enc->key, enc->key_len,
1.180 markus 776: enc->iv, enc->iv_len, crypt_type);
1.91 markus 777: /* Deleting the keys does not gain extra security */
778: /* memset(enc->iv, 0, enc->block_size);
1.147 djm 779: memset(enc->key, 0, enc->key_len);
780: memset(mac->key, 0, mac->key_len); */
1.118 markus 781: if ((comp->type == COMP_ZLIB ||
1.161 andreas 782: (comp->type == COMP_DELAYED &&
783: active_state->after_authentication)) && comp->enabled == 0) {
1.60 markus 784: packet_init_compression();
785: if (mode == MODE_OUT)
786: buffer_compress_init_send(6);
787: else
788: buffer_compress_init_recv();
1.57 markus 789: comp->enabled = 1;
790: }
1.109 markus 791: /*
792: * The 2^(blocksize*2) limit is too expensive for 3DES,
793: * blowfish, etc, so enforce a 1GB limit for small blocksizes.
794: */
795: if (enc->block_size >= 16)
796: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
797: else
798: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.161 andreas 799: if (active_state->rekey_limit)
800: *max_blocks = MIN(*max_blocks,
801: active_state->rekey_limit / enc->block_size);
1.57 markus 802: }
803:
1.16 markus 804: /*
1.118 markus 805: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 806: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 807: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
808: */
809: static void
810: packet_enable_delayed_compress(void)
811: {
812: Comp *comp = NULL;
813: int mode;
814:
815: /*
816: * Remember that we are past the authentication step, so rekeying
817: * with COMP_DELAYED will turn on compression immediately.
818: */
1.161 andreas 819: active_state->after_authentication = 1;
1.118 markus 820: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 821: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.161 andreas 822: if (active_state->newkeys[mode] == NULL)
1.145 markus 823: continue;
1.161 andreas 824: comp = &active_state->newkeys[mode]->comp;
1.118 markus 825: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.119 markus 826: packet_init_compression();
1.118 markus 827: if (mode == MODE_OUT)
828: buffer_compress_init_send(6);
829: else
830: buffer_compress_init_recv();
831: comp->enabled = 1;
832: }
833: }
834: }
835:
836: /*
1.25 markus 837: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
838: */
1.68 itojun 839: static void
1.105 markus 840: packet_send2_wrapped(void)
1.25 markus 841: {
1.89 markus 842: u_char type, *cp, *macbuf = NULL;
1.178 markus 843: u_char padlen, pad = 0;
1.180 markus 844: u_int i, len, authlen = 0, aadlen = 0;
1.115 avsm 845: u_int32_t rnd = 0;
1.25 markus 846: Enc *enc = NULL;
847: Mac *mac = NULL;
848: Comp *comp = NULL;
849: int block_size;
850:
1.161 andreas 851: if (active_state->newkeys[MODE_OUT] != NULL) {
852: enc = &active_state->newkeys[MODE_OUT]->enc;
853: mac = &active_state->newkeys[MODE_OUT]->mac;
854: comp = &active_state->newkeys[MODE_OUT]->comp;
1.180 markus 855: /* disable mac for authenticated encryption */
856: if ((authlen = cipher_authlen(enc->cipher)) != 0)
857: mac = NULL;
1.25 markus 858: }
1.88 markus 859: block_size = enc ? enc->block_size : 8;
1.180 markus 860: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 861:
1.161 andreas 862: cp = buffer_ptr(&active_state->outgoing_packet);
1.89 markus 863: type = cp[5];
1.25 markus 864:
865: #ifdef PACKET_DEBUG
866: fprintf(stderr, "plain: ");
1.161 andreas 867: buffer_dump(&active_state->outgoing_packet);
1.25 markus 868: #endif
869:
870: if (comp && comp->enabled) {
1.161 andreas 871: len = buffer_len(&active_state->outgoing_packet);
1.25 markus 872: /* skip header, compress only payload */
1.161 andreas 873: buffer_consume(&active_state->outgoing_packet, 5);
874: buffer_clear(&active_state->compression_buffer);
875: buffer_compress(&active_state->outgoing_packet,
876: &active_state->compression_buffer);
877: buffer_clear(&active_state->outgoing_packet);
878: buffer_append(&active_state->outgoing_packet, "\0\0\0\0\0", 5);
879: buffer_append(&active_state->outgoing_packet,
880: buffer_ptr(&active_state->compression_buffer),
881: buffer_len(&active_state->compression_buffer));
1.25 markus 882: DBG(debug("compression: raw %d compressed %d", len,
1.161 andreas 883: buffer_len(&active_state->outgoing_packet)));
1.25 markus 884: }
885:
886: /* sizeof (packet_len + pad_len + payload) */
1.161 andreas 887: len = buffer_len(&active_state->outgoing_packet);
1.25 markus 888:
889: /*
890: * calc size of padding, alloc space, get random data,
891: * minimum padding is 4 bytes
892: */
1.178 markus 893: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 894: padlen = block_size - (len % block_size);
895: if (padlen < 4)
896: padlen += block_size;
1.161 andreas 897: if (active_state->extra_pad) {
1.71 markus 898: /* will wrap if extra_pad+padlen > 255 */
1.161 andreas 899: active_state->extra_pad =
900: roundup(active_state->extra_pad, block_size);
901: pad = active_state->extra_pad -
902: ((len + padlen) % active_state->extra_pad);
1.93 markus 903: debug3("packet_send2: adding %d (len %d padlen %d extra_pad %d)",
1.161 andreas 904: pad, len, padlen, active_state->extra_pad);
1.71 markus 905: padlen += pad;
1.161 andreas 906: active_state->extra_pad = 0;
1.71 markus 907: }
1.161 andreas 908: cp = buffer_append_space(&active_state->outgoing_packet, padlen);
909: if (enc && !active_state->send_context.plaintext) {
1.32 markus 910: /* random padding */
1.25 markus 911: for (i = 0; i < padlen; i++) {
912: if (i % 4 == 0)
1.115 avsm 913: rnd = arc4random();
914: cp[i] = rnd & 0xff;
915: rnd >>= 8;
1.25 markus 916: }
1.32 markus 917: } else {
918: /* clear padding */
919: memset(cp, 0, padlen);
1.25 markus 920: }
1.178 markus 921: /* sizeof (packet_len + pad_len + payload + padding) */
922: len = buffer_len(&active_state->outgoing_packet);
923: cp = buffer_ptr(&active_state->outgoing_packet);
1.25 markus 924: /* packet_length includes payload, padding and padding length field */
1.178 markus 925: put_u32(cp, len - 4);
1.89 markus 926: cp[4] = padlen;
1.178 markus 927: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
928: len, padlen, aadlen));
1.25 markus 929:
930: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 931: if (mac && mac->enabled && !mac->etm) {
1.161 andreas 932: macbuf = mac_compute(mac, active_state->p_send.seqnr,
1.178 markus 933: buffer_ptr(&active_state->outgoing_packet), len);
1.161 andreas 934: DBG(debug("done calc MAC out #%d", active_state->p_send.seqnr));
1.25 markus 935: }
936: /* encrypt packet and append to output buffer. */
1.180 markus 937: cp = buffer_append_space(&active_state->output, len + authlen);
1.161 andreas 938: cipher_crypt(&active_state->send_context, cp,
939: buffer_ptr(&active_state->outgoing_packet),
1.180 markus 940: len - aadlen, aadlen, authlen);
1.25 markus 941: /* append unencrypted MAC */
1.178 markus 942: if (mac && mac->enabled) {
943: if (mac->etm) {
944: /* EtM: compute mac over aadlen + cipher text */
945: macbuf = mac_compute(mac,
946: active_state->p_send.seqnr, cp, len);
947: DBG(debug("done calc MAC(EtM) out #%d",
948: active_state->p_send.seqnr));
949: }
1.161 andreas 950: buffer_append(&active_state->output, macbuf, mac->mac_len);
1.178 markus 951: }
1.25 markus 952: #ifdef PACKET_DEBUG
953: fprintf(stderr, "encrypted: ");
1.161 andreas 954: buffer_dump(&active_state->output);
1.25 markus 955: #endif
1.29 markus 956: /* increment sequence number for outgoing packets */
1.161 andreas 957: if (++active_state->p_send.seqnr == 0)
1.106 itojun 958: logit("outgoing seqnr wraps around");
1.161 andreas 959: if (++active_state->p_send.packets == 0)
1.105 markus 960: if (!(datafellows & SSH_BUG_NOREKEY))
961: fatal("XXX too many packets with same key");
1.178 markus 962: active_state->p_send.blocks += len / block_size;
963: active_state->p_send.bytes += len;
1.161 andreas 964: buffer_clear(&active_state->outgoing_packet);
1.25 markus 965:
1.57 markus 966: if (type == SSH2_MSG_NEWKEYS)
967: set_newkeys(MODE_OUT);
1.161 andreas 968: else if (type == SSH2_MSG_USERAUTH_SUCCESS && active_state->server_side)
1.118 markus 969: packet_enable_delayed_compress();
1.25 markus 970: }
971:
1.105 markus 972: static void
973: packet_send2(void)
974: {
975: struct packet *p;
976: u_char type, *cp;
977:
1.161 andreas 978: cp = buffer_ptr(&active_state->outgoing_packet);
1.105 markus 979: type = cp[5];
980:
981: /* during rekeying we can only send key exchange messages */
1.165 andreas 982: if (active_state->rekeying) {
1.175 markus 983: if ((type < SSH2_MSG_TRANSPORT_MIN) ||
984: (type > SSH2_MSG_TRANSPORT_MAX) ||
985: (type == SSH2_MSG_SERVICE_REQUEST) ||
986: (type == SSH2_MSG_SERVICE_ACCEPT)) {
1.105 markus 987: debug("enqueue packet: %u", type);
988: p = xmalloc(sizeof(*p));
989: p->type = type;
1.161 andreas 990: memcpy(&p->payload, &active_state->outgoing_packet,
991: sizeof(Buffer));
992: buffer_init(&active_state->outgoing_packet);
993: TAILQ_INSERT_TAIL(&active_state->outgoing, p, next);
1.105 markus 994: return;
995: }
996: }
997:
998: /* rekeying starts with sending KEXINIT */
999: if (type == SSH2_MSG_KEXINIT)
1.165 andreas 1000: active_state->rekeying = 1;
1.105 markus 1001:
1002: packet_send2_wrapped();
1003:
1004: /* after a NEWKEYS message we can send the complete queue */
1005: if (type == SSH2_MSG_NEWKEYS) {
1.165 andreas 1006: active_state->rekeying = 0;
1.184 dtucker 1007: active_state->rekey_time = time(NULL);
1.161 andreas 1008: while ((p = TAILQ_FIRST(&active_state->outgoing))) {
1.105 markus 1009: type = p->type;
1010: debug("dequeue packet: %u", type);
1.161 andreas 1011: buffer_free(&active_state->outgoing_packet);
1012: memcpy(&active_state->outgoing_packet, &p->payload,
1.105 markus 1013: sizeof(Buffer));
1.161 andreas 1014: TAILQ_REMOVE(&active_state->outgoing, p, next);
1.105 markus 1015: xfree(p);
1016: packet_send2_wrapped();
1017: }
1018: }
1019: }
1020:
1.25 markus 1021: void
1.73 itojun 1022: packet_send(void)
1.25 markus 1023: {
1.62 markus 1024: if (compat20)
1.25 markus 1025: packet_send2();
1026: else
1027: packet_send1();
1028: DBG(debug("packet_send done"));
1029: }
1030:
1031: /*
1.16 markus 1032: * Waits until a packet has been received, and returns its type. Note that
1033: * no other data is processed until this returns, so this function should not
1034: * be used during the interactive session.
1035: */
1.1 deraadt 1036:
1.2 provos 1037: int
1.82 markus 1038: packet_read_seqnr(u_int32_t *seqnr_p)
1.1 deraadt 1039: {
1.163 andreas 1040: int type, len, ret, ms_remain, cont;
1.56 millert 1041: fd_set *setp;
1.14 markus 1042: char buf[8192];
1.155 deraadt 1043: struct timeval timeout, start, *timeoutp = NULL;
1044:
1.25 markus 1045: DBG(debug("packet_read()"));
1.14 markus 1046:
1.161 andreas 1047: setp = (fd_set *)xcalloc(howmany(active_state->connection_in + 1,
1048: NFDBITS), sizeof(fd_mask));
1.56 millert 1049:
1.14 markus 1050: /* Since we are blocking, ensure that all written packets have been sent. */
1051: packet_write_wait();
1052:
1053: /* Stay in the loop until we have received a complete packet. */
1054: for (;;) {
1055: /* Try to read a packet from the buffer. */
1.82 markus 1056: type = packet_read_poll_seqnr(seqnr_p);
1.62 markus 1057: if (!compat20 && (
1.32 markus 1058: type == SSH_SMSG_SUCCESS
1.14 markus 1059: || type == SSH_SMSG_FAILURE
1060: || type == SSH_CMSG_EOF
1.32 markus 1061: || type == SSH_CMSG_EXIT_CONFIRMATION))
1.79 markus 1062: packet_check_eom();
1.14 markus 1063: /* If we got a packet, return it. */
1.56 millert 1064: if (type != SSH_MSG_NONE) {
1065: xfree(setp);
1.14 markus 1066: return type;
1.56 millert 1067: }
1.16 markus 1068: /*
1069: * Otherwise, wait for some data to arrive, add it to the
1070: * buffer, and try again.
1071: */
1.161 andreas 1072: memset(setp, 0, howmany(active_state->connection_in + 1,
1073: NFDBITS) * sizeof(fd_mask));
1074: FD_SET(active_state->connection_in, setp);
1.16 markus 1075:
1.161 andreas 1076: if (active_state->packet_timeout_ms > 0) {
1077: ms_remain = active_state->packet_timeout_ms;
1.154 dtucker 1078: timeoutp = &timeout;
1079: }
1.14 markus 1080: /* Wait for some data to arrive. */
1.154 dtucker 1081: for (;;) {
1.161 andreas 1082: if (active_state->packet_timeout_ms != -1) {
1.154 dtucker 1083: ms_to_timeval(&timeout, ms_remain);
1084: gettimeofday(&start, NULL);
1085: }
1.161 andreas 1086: if ((ret = select(active_state->connection_in + 1, setp,
1087: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1088: break;
1.161 andreas 1089: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1090: break;
1.161 andreas 1091: if (active_state->packet_timeout_ms == -1)
1.154 dtucker 1092: continue;
1093: ms_subtract_diff(&start, &ms_remain);
1094: if (ms_remain <= 0) {
1095: ret = 0;
1096: break;
1097: }
1098: }
1099: if (ret == 0) {
1100: logit("Connection to %.200s timed out while "
1101: "waiting to read", get_remote_ipaddr());
1102: cleanup_exit(255);
1103: }
1.14 markus 1104: /* Read data from the socket. */
1.163 andreas 1105: do {
1106: cont = 0;
1107: len = roaming_read(active_state->connection_in, buf,
1108: sizeof(buf), &cont);
1109: } while (len == 0 && cont);
1.18 markus 1110: if (len == 0) {
1.106 itojun 1111: logit("Connection closed by %.200s", get_remote_ipaddr());
1.112 markus 1112: cleanup_exit(255);
1.18 markus 1113: }
1.14 markus 1114: if (len < 0)
1115: fatal("Read from socket failed: %.100s", strerror(errno));
1116: /* Append it to the buffer. */
1117: packet_process_incoming(buf, len);
1118: }
1119: /* NOTREACHED */
1.1 deraadt 1120: }
1121:
1.77 djm 1122: int
1.82 markus 1123: packet_read(void)
1.77 djm 1124: {
1.82 markus 1125: return packet_read_seqnr(NULL);
1.77 djm 1126: }
1127:
1.16 markus 1128: /*
1129: * Waits until a packet has been received, verifies that its type matches
1130: * that given, and gives a fatal error and exits if there is a mismatch.
1131: */
1.1 deraadt 1132:
1.2 provos 1133: void
1.82 markus 1134: packet_read_expect(int expected_type)
1.1 deraadt 1135: {
1.14 markus 1136: int type;
1.1 deraadt 1137:
1.82 markus 1138: type = packet_read();
1.14 markus 1139: if (type != expected_type)
1140: packet_disconnect("Protocol error: expected packet type %d, got %d",
1.25 markus 1141: expected_type, type);
1.1 deraadt 1142: }
1143:
1144: /* Checks if a full packet is available in the data received so far via
1.14 markus 1145: * packet_process_incoming. If so, reads the packet; otherwise returns
1146: * SSH_MSG_NONE. This does not wait for data from the connection.
1147: *
1.150 dtucker 1148: * SSH_MSG_DISCONNECT is handled specially here. Also,
1149: * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1150: * to higher levels.
1.14 markus 1151: */
1.1 deraadt 1152:
1.68 itojun 1153: static int
1.82 markus 1154: packet_read_poll1(void)
1.1 deraadt 1155: {
1.40 markus 1156: u_int len, padded_len;
1.89 markus 1157: u_char *cp, type;
1.40 markus 1158: u_int checksum, stored_checksum;
1.14 markus 1159:
1160: /* Check if input size is less than minimum packet size. */
1.161 andreas 1161: if (buffer_len(&active_state->input) < 4 + 8)
1.14 markus 1162: return SSH_MSG_NONE;
1163: /* Get length of incoming packet. */
1.161 andreas 1164: cp = buffer_ptr(&active_state->input);
1.131 djm 1165: len = get_u32(cp);
1.14 markus 1166: if (len < 1 + 2 + 2 || len > 256 * 1024)
1.98 markus 1167: packet_disconnect("Bad packet length %u.", len);
1.14 markus 1168: padded_len = (len + 8) & ~7;
1169:
1170: /* Check if the packet has been entirely received. */
1.161 andreas 1171: if (buffer_len(&active_state->input) < 4 + padded_len)
1.14 markus 1172: return SSH_MSG_NONE;
1173:
1174: /* The entire packet is in buffer. */
1175:
1176: /* Consume packet length. */
1.161 andreas 1177: buffer_consume(&active_state->input, 4);
1.14 markus 1178:
1.62 markus 1179: /*
1180: * Cryptographic attack detector for ssh
1181: * (C)1998 CORE-SDI, Buenos Aires Argentina
1182: * Ariel Futoransky(futo@core-sdi.com)
1183: */
1.161 andreas 1184: if (!active_state->receive_context.plaintext) {
1185: switch (detect_attack(buffer_ptr(&active_state->input),
1186: padded_len)) {
1.144 djm 1187: case DEATTACK_DETECTED:
1188: packet_disconnect("crc32 compensation attack: "
1189: "network attack detected");
1190: case DEATTACK_DOS_DETECTED:
1191: packet_disconnect("deattack denial of "
1192: "service detected");
1193: }
1194: }
1.62 markus 1195:
1196: /* Decrypt data to incoming_packet. */
1.161 andreas 1197: buffer_clear(&active_state->incoming_packet);
1198: cp = buffer_append_space(&active_state->incoming_packet, padded_len);
1199: cipher_crypt(&active_state->receive_context, cp,
1.180 markus 1200: buffer_ptr(&active_state->input), padded_len, 0, 0);
1.62 markus 1201:
1.161 andreas 1202: buffer_consume(&active_state->input, padded_len);
1.1 deraadt 1203:
1204: #ifdef PACKET_DEBUG
1.14 markus 1205: fprintf(stderr, "read_poll plain: ");
1.161 andreas 1206: buffer_dump(&active_state->incoming_packet);
1.1 deraadt 1207: #endif
1208:
1.14 markus 1209: /* Compute packet checksum. */
1.161 andreas 1210: checksum = ssh_crc32(buffer_ptr(&active_state->incoming_packet),
1211: buffer_len(&active_state->incoming_packet) - 4);
1.14 markus 1212:
1213: /* Skip padding. */
1.161 andreas 1214: buffer_consume(&active_state->incoming_packet, 8 - len % 8);
1.14 markus 1215:
1216: /* Test check bytes. */
1.161 andreas 1217: if (len != buffer_len(&active_state->incoming_packet))
1.77 djm 1218: packet_disconnect("packet_read_poll1: len %d != buffer_len %d.",
1.161 andreas 1219: len, buffer_len(&active_state->incoming_packet));
1.14 markus 1220:
1.161 andreas 1221: cp = (u_char *)buffer_ptr(&active_state->incoming_packet) + len - 4;
1.131 djm 1222: stored_checksum = get_u32(cp);
1.14 markus 1223: if (checksum != stored_checksum)
1224: packet_disconnect("Corrupted check bytes on input.");
1.161 andreas 1225: buffer_consume_end(&active_state->incoming_packet, 4);
1.14 markus 1226:
1.161 andreas 1227: if (active_state->packet_compression) {
1228: buffer_clear(&active_state->compression_buffer);
1229: buffer_uncompress(&active_state->incoming_packet,
1230: &active_state->compression_buffer);
1231: buffer_clear(&active_state->incoming_packet);
1232: buffer_append(&active_state->incoming_packet,
1233: buffer_ptr(&active_state->compression_buffer),
1234: buffer_len(&active_state->compression_buffer));
1235: }
1236: active_state->p_read.packets++;
1237: active_state->p_read.bytes += padded_len + 4;
1238: type = buffer_get_char(&active_state->incoming_packet);
1.116 markus 1239: if (type < SSH_MSG_MIN || type > SSH_MSG_MAX)
1240: packet_disconnect("Invalid ssh1 packet type: %d", type);
1.62 markus 1241: return type;
1.1 deraadt 1242: }
1.14 markus 1243:
1.68 itojun 1244: static int
1.82 markus 1245: packet_read_poll2(u_int32_t *seqnr_p)
1.25 markus 1246: {
1.40 markus 1247: u_int padlen, need;
1.178 markus 1248: u_char *macbuf = NULL, *cp, type;
1.180 markus 1249: u_int maclen, authlen = 0, aadlen = 0, block_size;
1.25 markus 1250: Enc *enc = NULL;
1251: Mac *mac = NULL;
1252: Comp *comp = NULL;
1253:
1.161 andreas 1254: if (active_state->packet_discard)
1.159 markus 1255: return SSH_MSG_NONE;
1256:
1.161 andreas 1257: if (active_state->newkeys[MODE_IN] != NULL) {
1258: enc = &active_state->newkeys[MODE_IN]->enc;
1259: mac = &active_state->newkeys[MODE_IN]->mac;
1260: comp = &active_state->newkeys[MODE_IN]->comp;
1.180 markus 1261: /* disable mac for authenticated encryption */
1262: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1263: mac = NULL;
1.25 markus 1264: }
1265: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1266: block_size = enc ? enc->block_size : 8;
1.180 markus 1267: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1268:
1.178 markus 1269: if (aadlen && active_state->packlen == 0) {
1270: if (buffer_len(&active_state->input) < 4)
1271: return SSH_MSG_NONE;
1272: cp = buffer_ptr(&active_state->input);
1273: active_state->packlen = get_u32(cp);
1274: if (active_state->packlen < 1 + 4 ||
1275: active_state->packlen > PACKET_MAX_SIZE) {
1276: #ifdef PACKET_DEBUG
1277: buffer_dump(&active_state->input);
1278: #endif
1279: logit("Bad packet length %u.", active_state->packlen);
1280: packet_disconnect("Packet corrupt");
1281: }
1.179 markus 1282: buffer_clear(&active_state->incoming_packet);
1.178 markus 1283: } else if (active_state->packlen == 0) {
1.25 markus 1284: /*
1285: * check if input size is less than the cipher block size,
1286: * decrypt first block and extract length of incoming packet
1287: */
1.161 andreas 1288: if (buffer_len(&active_state->input) < block_size)
1.25 markus 1289: return SSH_MSG_NONE;
1.161 andreas 1290: buffer_clear(&active_state->incoming_packet);
1291: cp = buffer_append_space(&active_state->incoming_packet,
1.25 markus 1292: block_size);
1.161 andreas 1293: cipher_crypt(&active_state->receive_context, cp,
1.180 markus 1294: buffer_ptr(&active_state->input), block_size, 0, 0);
1.161 andreas 1295: cp = buffer_ptr(&active_state->incoming_packet);
1296: active_state->packlen = get_u32(cp);
1297: if (active_state->packlen < 1 + 4 ||
1298: active_state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1299: #ifdef PACKET_DEBUG
1.161 andreas 1300: buffer_dump(&active_state->incoming_packet);
1.110 markus 1301: #endif
1.161 andreas 1302: logit("Bad packet length %u.", active_state->packlen);
1303: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1304: PACKET_MAX_SIZE);
1305: return SSH_MSG_NONE;
1.25 markus 1306: }
1.161 andreas 1307: buffer_consume(&active_state->input, block_size);
1.25 markus 1308: }
1.178 markus 1309: DBG(debug("input: packet len %u", active_state->packlen+4));
1310: if (aadlen) {
1311: /* only the payload is encrypted */
1312: need = active_state->packlen;
1313: } else {
1314: /*
1315: * the payload size and the payload are encrypted, but we
1316: * have a partial packet of block_size bytes
1317: */
1318: need = 4 + active_state->packlen - block_size;
1319: }
1.180 markus 1320: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1321: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1322: if (need % block_size != 0) {
1323: logit("padding error: need %d block %d mod %d",
1.25 markus 1324: need, block_size, need % block_size);
1.161 andreas 1325: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1326: PACKET_MAX_SIZE - block_size);
1327: return SSH_MSG_NONE;
1.158 markus 1328: }
1.25 markus 1329: /*
1330: * check if the entire packet has been received and
1.178 markus 1331: * decrypt into incoming_packet:
1332: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1333: * 'need' bytes are encrypted, followed by either
1334: * 'authlen' bytes of authentication tag or
1.178 markus 1335: * 'maclen' bytes of message authentication code.
1.25 markus 1336: */
1.180 markus 1337: if (buffer_len(&active_state->input) < aadlen + need + authlen + maclen)
1.25 markus 1338: return SSH_MSG_NONE;
1339: #ifdef PACKET_DEBUG
1340: fprintf(stderr, "read_poll enc/full: ");
1.161 andreas 1341: buffer_dump(&active_state->input);
1.25 markus 1342: #endif
1.178 markus 1343: /* EtM: compute mac over encrypted input */
1344: if (mac && mac->enabled && mac->etm)
1345: macbuf = mac_compute(mac, active_state->p_read.seqnr,
1346: buffer_ptr(&active_state->input), aadlen + need);
1347: cp = buffer_append_space(&active_state->incoming_packet, aadlen + need);
1.161 andreas 1348: cipher_crypt(&active_state->receive_context, cp,
1.180 markus 1349: buffer_ptr(&active_state->input), need, aadlen, authlen);
1350: buffer_consume(&active_state->input, aadlen + need + authlen);
1.25 markus 1351: /*
1352: * compute MAC over seqnr and packet,
1353: * increment sequence number for incoming packet
1354: */
1.29 markus 1355: if (mac && mac->enabled) {
1.178 markus 1356: if (!mac->etm)
1357: macbuf = mac_compute(mac, active_state->p_read.seqnr,
1358: buffer_ptr(&active_state->incoming_packet),
1359: buffer_len(&active_state->incoming_packet));
1.168 djm 1360: if (timingsafe_bcmp(macbuf, buffer_ptr(&active_state->input),
1.161 andreas 1361: mac->mac_len) != 0) {
1.159 markus 1362: logit("Corrupted MAC on input.");
1363: if (need > PACKET_MAX_SIZE)
1364: fatal("internal error need %d", need);
1.161 andreas 1365: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1366: PACKET_MAX_SIZE - need);
1367: return SSH_MSG_NONE;
1368: }
1369:
1.161 andreas 1370: DBG(debug("MAC #%d ok", active_state->p_read.seqnr));
1371: buffer_consume(&active_state->input, mac->mac_len);
1.25 markus 1372: }
1.159 markus 1373: /* XXX now it's safe to use fatal/packet_disconnect */
1.77 djm 1374: if (seqnr_p != NULL)
1.161 andreas 1375: *seqnr_p = active_state->p_read.seqnr;
1376: if (++active_state->p_read.seqnr == 0)
1.106 itojun 1377: logit("incoming seqnr wraps around");
1.161 andreas 1378: if (++active_state->p_read.packets == 0)
1.105 markus 1379: if (!(datafellows & SSH_BUG_NOREKEY))
1380: fatal("XXX too many packets with same key");
1.161 andreas 1381: active_state->p_read.blocks += (active_state->packlen + 4) / block_size;
1382: active_state->p_read.bytes += active_state->packlen + 4;
1.25 markus 1383:
1384: /* get padlen */
1.161 andreas 1385: cp = buffer_ptr(&active_state->incoming_packet);
1.89 markus 1386: padlen = cp[4];
1.25 markus 1387: DBG(debug("input: padlen %d", padlen));
1388: if (padlen < 4)
1389: packet_disconnect("Corrupted padlen %d on input.", padlen);
1390:
1391: /* skip packet size + padlen, discard padding */
1.161 andreas 1392: buffer_consume(&active_state->incoming_packet, 4 + 1);
1393: buffer_consume_end(&active_state->incoming_packet, padlen);
1.25 markus 1394:
1.161 andreas 1395: DBG(debug("input: len before de-compress %d",
1396: buffer_len(&active_state->incoming_packet)));
1.25 markus 1397: if (comp && comp->enabled) {
1.161 andreas 1398: buffer_clear(&active_state->compression_buffer);
1399: buffer_uncompress(&active_state->incoming_packet,
1400: &active_state->compression_buffer);
1401: buffer_clear(&active_state->incoming_packet);
1402: buffer_append(&active_state->incoming_packet,
1403: buffer_ptr(&active_state->compression_buffer),
1404: buffer_len(&active_state->compression_buffer));
1.97 deraadt 1405: DBG(debug("input: len after de-compress %d",
1.161 andreas 1406: buffer_len(&active_state->incoming_packet)));
1.25 markus 1407: }
1408: /*
1409: * get packet type, implies consume.
1410: * return length of payload (without type field)
1411: */
1.161 andreas 1412: type = buffer_get_char(&active_state->incoming_packet);
1.116 markus 1413: if (type < SSH2_MSG_MIN || type >= SSH2_MSG_LOCAL_MIN)
1414: packet_disconnect("Invalid ssh2 packet type: %d", type);
1.57 markus 1415: if (type == SSH2_MSG_NEWKEYS)
1416: set_newkeys(MODE_IN);
1.161 andreas 1417: else if (type == SSH2_MSG_USERAUTH_SUCCESS &&
1418: !active_state->server_side)
1.118 markus 1419: packet_enable_delayed_compress();
1.25 markus 1420: #ifdef PACKET_DEBUG
1.55 deraadt 1421: fprintf(stderr, "read/plain[%d]:\r\n", type);
1.161 andreas 1422: buffer_dump(&active_state->incoming_packet);
1.25 markus 1423: #endif
1.62 markus 1424: /* reset for next packet */
1.161 andreas 1425: active_state->packlen = 0;
1.62 markus 1426: return type;
1.25 markus 1427: }
1428:
1429: int
1.82 markus 1430: packet_read_poll_seqnr(u_int32_t *seqnr_p)
1.25 markus 1431: {
1.96 deraadt 1432: u_int reason, seqnr;
1.62 markus 1433: u_char type;
1.25 markus 1434: char *msg;
1.62 markus 1435:
1.25 markus 1436: for (;;) {
1.62 markus 1437: if (compat20) {
1.82 markus 1438: type = packet_read_poll2(seqnr_p);
1.153 djm 1439: if (type) {
1.161 andreas 1440: active_state->keep_alive_timeouts = 0;
1.25 markus 1441: DBG(debug("received packet type %d", type));
1.153 djm 1442: }
1.74 deraadt 1443: switch (type) {
1.150 dtucker 1444: case SSH2_MSG_IGNORE:
1.151 dtucker 1445: debug3("Received SSH2_MSG_IGNORE");
1.150 dtucker 1446: break;
1.25 markus 1447: case SSH2_MSG_DEBUG:
1448: packet_get_char();
1449: msg = packet_get_string(NULL);
1450: debug("Remote: %.900s", msg);
1451: xfree(msg);
1452: msg = packet_get_string(NULL);
1453: xfree(msg);
1454: break;
1455: case SSH2_MSG_DISCONNECT:
1456: reason = packet_get_int();
1457: msg = packet_get_string(NULL);
1.182 djm 1458: /* Ignore normal client exit notifications */
1459: do_log2(active_state->server_side &&
1460: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1461: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1462: "Received disconnect from %s: %u: %.400s",
1.96 deraadt 1463: get_remote_ipaddr(), reason, msg);
1.25 markus 1464: xfree(msg);
1.112 markus 1465: cleanup_exit(255);
1.84 markus 1466: break;
1467: case SSH2_MSG_UNIMPLEMENTED:
1468: seqnr = packet_get_int();
1.96 deraadt 1469: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1470: seqnr);
1.150 dtucker 1471: break;
1.25 markus 1472: default:
1473: return type;
1.48 stevesk 1474: }
1.25 markus 1475: } else {
1.82 markus 1476: type = packet_read_poll1();
1.74 deraadt 1477: switch (type) {
1.25 markus 1478: case SSH_MSG_IGNORE:
1479: break;
1480: case SSH_MSG_DEBUG:
1481: msg = packet_get_string(NULL);
1482: debug("Remote: %.900s", msg);
1483: xfree(msg);
1484: break;
1485: case SSH_MSG_DISCONNECT:
1486: msg = packet_get_string(NULL);
1.181 djm 1487: error("Received disconnect from %s: %.400s",
1.96 deraadt 1488: get_remote_ipaddr(), msg);
1.112 markus 1489: cleanup_exit(255);
1.25 markus 1490: break;
1491: default:
1.62 markus 1492: if (type)
1.25 markus 1493: DBG(debug("received packet type %d", type));
1494: return type;
1.48 stevesk 1495: }
1.25 markus 1496: }
1497: }
1498: }
1499:
1.16 markus 1500: /*
1501: * Buffers the given amount of input characters. This is intended to be used
1502: * together with packet_read_poll.
1503: */
1.1 deraadt 1504:
1.2 provos 1505: void
1.40 markus 1506: packet_process_incoming(const char *buf, u_int len)
1.1 deraadt 1507: {
1.161 andreas 1508: if (active_state->packet_discard) {
1509: active_state->keep_alive_timeouts = 0; /* ?? */
1510: if (len >= active_state->packet_discard)
1.159 markus 1511: packet_stop_discard();
1.161 andreas 1512: active_state->packet_discard -= len;
1.159 markus 1513: return;
1514: }
1.161 andreas 1515: buffer_append(&active_state->input, buf, len);
1.1 deraadt 1516: }
1517:
1518: /* Returns a character from the packet. */
1519:
1.40 markus 1520: u_int
1.73 itojun 1521: packet_get_char(void)
1.1 deraadt 1522: {
1.14 markus 1523: char ch;
1.97 deraadt 1524:
1.161 andreas 1525: buffer_get(&active_state->incoming_packet, &ch, 1);
1.40 markus 1526: return (u_char) ch;
1.1 deraadt 1527: }
1528:
1529: /* Returns an integer from the packet data. */
1530:
1.40 markus 1531: u_int
1.73 itojun 1532: packet_get_int(void)
1.1 deraadt 1533: {
1.161 andreas 1534: return buffer_get_int(&active_state->incoming_packet);
1.162 andreas 1535: }
1536:
1537: /* Returns an 64 bit integer from the packet data. */
1538:
1539: u_int64_t
1540: packet_get_int64(void)
1541: {
1542: return buffer_get_int64(&active_state->incoming_packet);
1.1 deraadt 1543: }
1544:
1.16 markus 1545: /*
1546: * Returns an arbitrary precision integer from the packet data. The integer
1547: * must have been initialized before this call.
1548: */
1.1 deraadt 1549:
1.2 provos 1550: void
1.80 markus 1551: packet_get_bignum(BIGNUM * value)
1.1 deraadt 1552: {
1.161 andreas 1553: buffer_get_bignum(&active_state->incoming_packet, value);
1.24 markus 1554: }
1555:
1556: void
1.80 markus 1557: packet_get_bignum2(BIGNUM * value)
1.24 markus 1558: {
1.161 andreas 1559: buffer_get_bignum2(&active_state->incoming_packet, value);
1.170 djm 1560: }
1561:
1562: void
1563: packet_get_ecpoint(const EC_GROUP *curve, EC_POINT *point)
1564: {
1565: buffer_get_ecpoint(&active_state->incoming_packet, curve, point);
1.24 markus 1566: }
1567:
1.76 stevesk 1568: void *
1.117 djm 1569: packet_get_raw(u_int *length_ptr)
1.24 markus 1570: {
1.161 andreas 1571: u_int bytes = buffer_len(&active_state->incoming_packet);
1.97 deraadt 1572:
1.24 markus 1573: if (length_ptr != NULL)
1574: *length_ptr = bytes;
1.161 andreas 1575: return buffer_ptr(&active_state->incoming_packet);
1.28 markus 1576: }
1577:
1578: int
1579: packet_remaining(void)
1580: {
1.161 andreas 1581: return buffer_len(&active_state->incoming_packet);
1.1 deraadt 1582: }
1583:
1.16 markus 1584: /*
1585: * Returns a string from the packet data. The string is allocated using
1586: * xmalloc; it is the responsibility of the calling program to free it when
1587: * no longer needed. The length_ptr argument may be NULL, or point to an
1588: * integer into which the length of the string is stored.
1589: */
1.1 deraadt 1590:
1.76 stevesk 1591: void *
1.40 markus 1592: packet_get_string(u_int *length_ptr)
1.1 deraadt 1593: {
1.161 andreas 1594: return buffer_get_string(&active_state->incoming_packet, length_ptr);
1.152 markus 1595: }
1596:
1597: void *
1598: packet_get_string_ptr(u_int *length_ptr)
1599: {
1.161 andreas 1600: return buffer_get_string_ptr(&active_state->incoming_packet, length_ptr);
1.169 djm 1601: }
1602:
1603: /* Ensures the returned string has no embedded \0 characters in it. */
1604: char *
1605: packet_get_cstring(u_int *length_ptr)
1606: {
1607: return buffer_get_cstring(&active_state->incoming_packet, length_ptr);
1.1 deraadt 1608: }
1609:
1.16 markus 1610: /*
1611: * Sends a diagnostic message from the server to the client. This message
1612: * can be sent at any time (but not while constructing another message). The
1613: * message is printed immediately, but only if the client is being executed
1614: * in verbose mode. These messages are primarily intended to ease debugging
1615: * authentication problems. The length of the formatted message must not
1616: * exceed 1024 bytes. This will automatically call packet_write_wait.
1617: */
1.1 deraadt 1618:
1.2 provos 1619: void
1.14 markus 1620: packet_send_debug(const char *fmt,...)
1.1 deraadt 1621: {
1.14 markus 1622: char buf[1024];
1623: va_list args;
1.39 markus 1624:
1625: if (compat20 && (datafellows & SSH_BUG_DEBUG))
1626: return;
1.14 markus 1627:
1628: va_start(args, fmt);
1629: vsnprintf(buf, sizeof(buf), fmt, args);
1630: va_end(args);
1631:
1.30 markus 1632: if (compat20) {
1633: packet_start(SSH2_MSG_DEBUG);
1634: packet_put_char(0); /* bool: always display */
1635: packet_put_cstring(buf);
1636: packet_put_cstring("");
1637: } else {
1638: packet_start(SSH_MSG_DEBUG);
1639: packet_put_cstring(buf);
1640: }
1.14 markus 1641: packet_send();
1642: packet_write_wait();
1.1 deraadt 1643: }
1644:
1.16 markus 1645: /*
1646: * Logs the error plus constructs and sends a disconnect packet, closes the
1647: * connection, and exits. This function never returns. The error message
1648: * should not contain a newline. The length of the formatted message must
1649: * not exceed 1024 bytes.
1650: */
1.1 deraadt 1651:
1.2 provos 1652: void
1.14 markus 1653: packet_disconnect(const char *fmt,...)
1.1 deraadt 1654: {
1.14 markus 1655: char buf[1024];
1656: va_list args;
1657: static int disconnecting = 0;
1.97 deraadt 1658:
1.14 markus 1659: if (disconnecting) /* Guard against recursive invocations. */
1660: fatal("packet_disconnect called recursively.");
1661: disconnecting = 1;
1662:
1.16 markus 1663: /*
1664: * Format the message. Note that the caller must make sure the
1665: * message is of limited size.
1666: */
1.14 markus 1667: va_start(args, fmt);
1668: vsnprintf(buf, sizeof(buf), fmt, args);
1669: va_end(args);
1670:
1.99 markus 1671: /* Display the error locally */
1.106 itojun 1672: logit("Disconnecting: %.100s", buf);
1.99 markus 1673:
1.14 markus 1674: /* Send the disconnect message to the other side, and wait for it to get sent. */
1.25 markus 1675: if (compat20) {
1676: packet_start(SSH2_MSG_DISCONNECT);
1677: packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR);
1678: packet_put_cstring(buf);
1679: packet_put_cstring("");
1680: } else {
1681: packet_start(SSH_MSG_DISCONNECT);
1.65 markus 1682: packet_put_cstring(buf);
1.25 markus 1683: }
1.14 markus 1684: packet_send();
1685: packet_write_wait();
1686:
1687: /* Stop listening for connections. */
1.67 markus 1688: channel_close_all();
1.14 markus 1689:
1690: /* Close the connection. */
1691: packet_close();
1.112 markus 1692: cleanup_exit(255);
1.1 deraadt 1693: }
1694:
1.16 markus 1695: /* Checks if there is any buffered output, and tries to write some of the output. */
1.1 deraadt 1696:
1.2 provos 1697: void
1.73 itojun 1698: packet_write_poll(void)
1.1 deraadt 1699: {
1.161 andreas 1700: int len = buffer_len(&active_state->output);
1.163 andreas 1701: int cont;
1.97 deraadt 1702:
1.14 markus 1703: if (len > 0) {
1.163 andreas 1704: cont = 0;
1705: len = roaming_write(active_state->connection_out,
1706: buffer_ptr(&active_state->output), len, &cont);
1.156 djm 1707: if (len == -1) {
1708: if (errno == EINTR || errno == EAGAIN)
1.14 markus 1709: return;
1.156 djm 1710: fatal("Write failed: %.100s", strerror(errno));
1.14 markus 1711: }
1.163 andreas 1712: if (len == 0 && !cont)
1.156 djm 1713: fatal("Write connection closed");
1.161 andreas 1714: buffer_consume(&active_state->output, len);
1.14 markus 1715: }
1.1 deraadt 1716: }
1717:
1.16 markus 1718: /*
1719: * Calls packet_write_poll repeatedly until all pending output data has been
1720: * written.
1721: */
1.1 deraadt 1722:
1.2 provos 1723: void
1.73 itojun 1724: packet_write_wait(void)
1.1 deraadt 1725: {
1.56 millert 1726: fd_set *setp;
1.154 dtucker 1727: int ret, ms_remain;
1728: struct timeval start, timeout, *timeoutp = NULL;
1.56 millert 1729:
1.161 andreas 1730: setp = (fd_set *)xcalloc(howmany(active_state->connection_out + 1,
1731: NFDBITS), sizeof(fd_mask));
1.14 markus 1732: packet_write_poll();
1733: while (packet_have_data_to_write()) {
1.161 andreas 1734: memset(setp, 0, howmany(active_state->connection_out + 1,
1735: NFDBITS) * sizeof(fd_mask));
1736: FD_SET(active_state->connection_out, setp);
1.154 dtucker 1737:
1.161 andreas 1738: if (active_state->packet_timeout_ms > 0) {
1739: ms_remain = active_state->packet_timeout_ms;
1.154 dtucker 1740: timeoutp = &timeout;
1741: }
1742: for (;;) {
1.161 andreas 1743: if (active_state->packet_timeout_ms != -1) {
1.154 dtucker 1744: ms_to_timeval(&timeout, ms_remain);
1745: gettimeofday(&start, NULL);
1746: }
1.161 andreas 1747: if ((ret = select(active_state->connection_out + 1,
1748: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1749: break;
1.161 andreas 1750: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1751: break;
1.161 andreas 1752: if (active_state->packet_timeout_ms == -1)
1.154 dtucker 1753: continue;
1754: ms_subtract_diff(&start, &ms_remain);
1755: if (ms_remain <= 0) {
1756: ret = 0;
1757: break;
1758: }
1759: }
1760: if (ret == 0) {
1761: logit("Connection to %.200s timed out while "
1762: "waiting to write", get_remote_ipaddr());
1763: cleanup_exit(255);
1764: }
1.14 markus 1765: packet_write_poll();
1766: }
1.56 millert 1767: xfree(setp);
1.1 deraadt 1768: }
1769:
1770: /* Returns true if there is buffered data to write to the connection. */
1771:
1.2 provos 1772: int
1.73 itojun 1773: packet_have_data_to_write(void)
1.1 deraadt 1774: {
1.161 andreas 1775: return buffer_len(&active_state->output) != 0;
1.1 deraadt 1776: }
1777:
1778: /* Returns true if there is not too much data to write to the connection. */
1779:
1.2 provos 1780: int
1.73 itojun 1781: packet_not_very_much_data_to_write(void)
1.1 deraadt 1782: {
1.161 andreas 1783: if (active_state->interactive_mode)
1784: return buffer_len(&active_state->output) < 16384;
1.14 markus 1785: else
1.161 andreas 1786: return buffer_len(&active_state->output) < 128 * 1024;
1.1 deraadt 1787: }
1788:
1.102 markus 1789: static void
1.172 djm 1790: packet_set_tos(int tos)
1.101 markus 1791: {
1.173 djm 1792: if (!packet_connection_is_on_socket())
1.101 markus 1793: return;
1.173 djm 1794: switch (packet_connection_af()) {
1795: case AF_INET:
1796: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1797: if (setsockopt(active_state->connection_in,
1798: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
1799: error("setsockopt IP_TOS %d: %.100s:",
1800: tos, strerror(errno));
1801: break;
1802: case AF_INET6:
1803: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1804: if (setsockopt(active_state->connection_in,
1805: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
1806: error("setsockopt IPV6_TCLASS %d: %.100s:",
1807: tos, strerror(errno));
1808: break;
1809: }
1.101 markus 1810: }
1811:
1.1 deraadt 1812: /* Informs that the current session is interactive. Sets IP flags for that. */
1813:
1.2 provos 1814: void
1.172 djm 1815: packet_set_interactive(int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 1816: {
1.165 andreas 1817: if (active_state->set_interactive_called)
1.43 markus 1818: return;
1.165 andreas 1819: active_state->set_interactive_called = 1;
1.1 deraadt 1820:
1.14 markus 1821: /* Record that we are in interactive mode. */
1.161 andreas 1822: active_state->interactive_mode = interactive;
1.1 deraadt 1823:
1.19 markus 1824: /* Only set socket options if using a socket. */
1825: if (!packet_connection_is_on_socket())
1.14 markus 1826: return;
1.161 andreas 1827: set_nodelay(active_state->connection_in);
1.172 djm 1828: packet_set_tos(interactive ? qos_interactive : qos_bulk);
1.1 deraadt 1829: }
1830:
1831: /* Returns true if the current connection is interactive. */
1832:
1.2 provos 1833: int
1.73 itojun 1834: packet_is_interactive(void)
1.1 deraadt 1835: {
1.161 andreas 1836: return active_state->interactive_mode;
1.12 markus 1837: }
1838:
1.113 deraadt 1839: int
1.108 markus 1840: packet_set_maxsize(u_int s)
1.12 markus 1841: {
1.165 andreas 1842: if (active_state->set_maxsize_called) {
1.106 itojun 1843: logit("packet_set_maxsize: called twice: old %d new %d",
1.161 andreas 1844: active_state->max_packet_size, s);
1.14 markus 1845: return -1;
1846: }
1847: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 1848: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 1849: return -1;
1850: }
1.165 andreas 1851: active_state->set_maxsize_called = 1;
1.66 markus 1852: debug("packet_set_maxsize: setting to %d", s);
1.161 andreas 1853: active_state->max_packet_size = s;
1.14 markus 1854: return s;
1.53 markus 1855: }
1856:
1.161 andreas 1857: int
1858: packet_inc_alive_timeouts(void)
1859: {
1860: return ++active_state->keep_alive_timeouts;
1861: }
1862:
1863: void
1864: packet_set_alive_timeouts(int ka)
1865: {
1866: active_state->keep_alive_timeouts = ka;
1867: }
1868:
1869: u_int
1870: packet_get_maxsize(void)
1871: {
1872: return active_state->max_packet_size;
1873: }
1874:
1.71 markus 1875: /* roundup current message to pad bytes */
1876: void
1877: packet_add_padding(u_char pad)
1878: {
1.161 andreas 1879: active_state->extra_pad = pad;
1.71 markus 1880: }
1881:
1.53 markus 1882: /*
1883: * 9.2. Ignored Data Message
1.61 markus 1884: *
1.53 markus 1885: * byte SSH_MSG_IGNORE
1886: * string data
1.61 markus 1887: *
1.53 markus 1888: * All implementations MUST understand (and ignore) this message at any
1889: * time (after receiving the protocol version). No implementation is
1890: * required to send them. This message can be used as an additional
1891: * protection measure against advanced traffic analysis techniques.
1892: */
1.54 markus 1893: void
1894: packet_send_ignore(int nbytes)
1895: {
1.115 avsm 1896: u_int32_t rnd = 0;
1.54 markus 1897: int i;
1898:
1899: packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE);
1.53 markus 1900: packet_put_int(nbytes);
1.75 deraadt 1901: for (i = 0; i < nbytes; i++) {
1.53 markus 1902: if (i % 4 == 0)
1.115 avsm 1903: rnd = arc4random();
1.129 deraadt 1904: packet_put_char((u_char)rnd & 0xff);
1.115 avsm 1905: rnd >>= 8;
1.53 markus 1906: }
1.105 markus 1907: }
1908:
1.113 deraadt 1909: #define MAX_PACKETS (1U<<31)
1.105 markus 1910: int
1911: packet_need_rekeying(void)
1912: {
1913: if (datafellows & SSH_BUG_NOREKEY)
1914: return 0;
1915: return
1.161 andreas 1916: (active_state->p_send.packets > MAX_PACKETS) ||
1917: (active_state->p_read.packets > MAX_PACKETS) ||
1918: (active_state->max_blocks_out &&
1919: (active_state->p_send.blocks > active_state->max_blocks_out)) ||
1920: (active_state->max_blocks_in &&
1.184 dtucker 1921: (active_state->p_read.blocks > active_state->max_blocks_in)) ||
1922: (active_state->rekey_interval != 0 && active_state->rekey_time +
1923: active_state->rekey_interval <= time(NULL));
1.105 markus 1924: }
1925:
1926: void
1.184 dtucker 1927: packet_set_rekey_limits(u_int32_t bytes, time_t seconds)
1.105 markus 1928: {
1.184 dtucker 1929: debug3("rekey after %lld bytes, %d seconds", (long long)bytes,
1930: (int)seconds);
1.161 andreas 1931: active_state->rekey_limit = bytes;
1.184 dtucker 1932: active_state->rekey_interval = seconds;
1933: /*
1934: * We set the time here so that in post-auth privsep slave we count
1935: * from the completion of the authentication.
1936: */
1937: active_state->rekey_time = time(NULL);
1938: }
1939:
1940: time_t
1941: packet_get_rekey_timeout(void)
1942: {
1943: time_t seconds;
1944:
1945: seconds = active_state->rekey_time + active_state->rekey_interval -
1946: time(NULL);
1.185 ! dtucker 1947: return (seconds <= 0 ? 1 : seconds);
1.118 markus 1948: }
1949:
1950: void
1951: packet_set_server(void)
1952: {
1.161 andreas 1953: active_state->server_side = 1;
1.118 markus 1954: }
1955:
1956: void
1957: packet_set_authenticated(void)
1958: {
1.161 andreas 1959: active_state->after_authentication = 1;
1960: }
1961:
1962: void *
1963: packet_get_input(void)
1964: {
1965: return (void *)&active_state->input;
1966: }
1967:
1968: void *
1969: packet_get_output(void)
1970: {
1971: return (void *)&active_state->output;
1972: }
1973:
1974: void *
1975: packet_get_newkeys(int mode)
1976: {
1977: return (void *)active_state->newkeys[mode];
1.166 andreas 1978: }
1979:
1980: /*
1981: * Save the state for the real connection, and use a separate state when
1982: * resuming a suspended connection.
1983: */
1984: void
1985: packet_backup_state(void)
1986: {
1987: struct session_state *tmp;
1988:
1989: close(active_state->connection_in);
1990: active_state->connection_in = -1;
1991: close(active_state->connection_out);
1992: active_state->connection_out = -1;
1993: if (backup_state)
1994: tmp = backup_state;
1995: else
1996: tmp = alloc_session_state();
1997: backup_state = active_state;
1998: active_state = tmp;
1999: }
2000:
2001: /*
2002: * Swap in the old state when resuming a connecion.
2003: */
2004: void
2005: packet_restore_state(void)
2006: {
2007: struct session_state *tmp;
2008: void *buf;
2009: u_int len;
2010:
2011: tmp = backup_state;
2012: backup_state = active_state;
2013: active_state = tmp;
2014: active_state->connection_in = backup_state->connection_in;
2015: backup_state->connection_in = -1;
2016: active_state->connection_out = backup_state->connection_out;
2017: backup_state->connection_out = -1;
2018: len = buffer_len(&backup_state->input);
2019: if (len > 0) {
2020: buf = buffer_ptr(&backup_state->input);
2021: buffer_append(&active_state->input, buf, len);
2022: buffer_clear(&backup_state->input);
2023: add_recv_bytes(len);
2024: }
1.1 deraadt 2025: }
![[BACK]](/icons/back.gif){kind=icon}
Return to packet.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh