Annotation of src/usr.bin/ssh/packet.c, Revision 1.166
1.166 ! andreas 1: /* $OpenBSD: packet.c,v 1.165 2009/06/12 20:58:32 andreas 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>
1.1 deraadt 57:
58: #include "xmalloc.h"
59: #include "buffer.h"
60: #include "packet.h"
61: #include "crc32.h"
62: #include "compress.h"
1.9 dugsong 63: #include "deattack.h"
1.64 markus 64: #include "channels.h"
1.25 markus 65: #include "compat.h"
1.45 markus 66: #include "ssh1.h"
1.25 markus 67: #include "ssh2.h"
1.37 markus 68: #include "cipher.h"
1.142 deraadt 69: #include "key.h"
1.25 markus 70: #include "kex.h"
1.50 markus 71: #include "mac.h"
1.46 markus 72: #include "log.h"
73: #include "canohost.h"
1.87 stevesk 74: #include "misc.h"
1.95 markus 75: #include "ssh.h"
1.163 andreas 76: #include "roaming.h"
1.25 markus 77:
78: #ifdef PACKET_DEBUG
79: #define DBG(x) x
80: #else
81: #define DBG(x)
82: #endif
83:
1.159 markus 84: #define PACKET_MAX_SIZE (256 * 1024)
85:
1.161 andreas 86: struct packet_state {
87: u_int32_t seqnr;
88: u_int32_t packets;
89: u_int64_t blocks;
90: u_int64_t bytes;
91: };
92:
93: struct packet {
94: TAILQ_ENTRY(packet) next;
95: u_char type;
96: Buffer payload;
97: };
98:
99: struct session_state {
100: /*
101: * This variable contains the file descriptors used for
102: * communicating with the other side. connection_in is used for
103: * reading; connection_out for writing. These can be the same
104: * descriptor, in which case it is assumed to be a socket.
105: */
106: int connection_in;
107: int connection_out;
108:
109: /* Protocol flags for the remote side. */
110: u_int remote_protocol_flags;
1.1 deraadt 111:
1.161 andreas 112: /* Encryption context for receiving data. Only used for decryption. */
113: CipherContext receive_context;
1.1 deraadt 114:
1.161 andreas 115: /* Encryption context for sending data. Only used for encryption. */
116: CipherContext send_context;
1.14 markus 117:
1.161 andreas 118: /* Buffer for raw input data from the socket. */
119: Buffer input;
1.1 deraadt 120:
1.161 andreas 121: /* Buffer for raw output data going to the socket. */
122: Buffer output;
1.1 deraadt 123:
1.161 andreas 124: /* Buffer for the partial outgoing packet being constructed. */
125: Buffer outgoing_packet;
1.1 deraadt 126:
1.161 andreas 127: /* Buffer for the incoming packet currently being processed. */
128: Buffer incoming_packet;
1.1 deraadt 129:
1.161 andreas 130: /* Scratch buffer for packet compression/decompression. */
131: Buffer compression_buffer;
132: int compression_buffer_ready;
1.1 deraadt 133:
1.161 andreas 134: /*
135: * Flag indicating whether packet compression/decompression is
136: * enabled.
137: */
138: int packet_compression;
1.1 deraadt 139:
1.161 andreas 140: /* default maximum packet size */
141: u_int max_packet_size;
1.1 deraadt 142:
1.161 andreas 143: /* Flag indicating whether this module has been initialized. */
144: int initialized;
1.12 markus 145:
1.161 andreas 146: /* Set to true if the connection is interactive. */
147: int interactive_mode;
1.1 deraadt 148:
1.161 andreas 149: /* Set to true if we are the server side. */
150: int server_side;
1.1 deraadt 151:
1.161 andreas 152: /* Set to true if we are authenticated. */
153: int after_authentication;
1.118 markus 154:
1.161 andreas 155: int keep_alive_timeouts;
1.118 markus 156:
1.161 andreas 157: /* The maximum time that we will wait to send or receive a packet */
158: int packet_timeout_ms;
1.151 dtucker 159:
1.161 andreas 160: /* Session key information for Encryption and MAC */
161: Newkeys *newkeys[MODE_MAX];
162: struct packet_state p_read, p_send;
1.154 dtucker 163:
1.161 andreas 164: u_int64_t max_blocks_in, max_blocks_out;
165: u_int32_t rekey_limit;
1.105 markus 166:
1.161 andreas 167: /* Session key for protocol v1 */
168: u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
169: u_int ssh1_keylen;
1.25 markus 170:
1.161 andreas 171: /* roundup current message to extra_pad bytes */
172: u_char extra_pad;
1.95 markus 173:
1.161 andreas 174: /* XXX discard incoming data after MAC error */
175: u_int packet_discard;
176: Mac *packet_discard_mac;
1.71 markus 177:
1.161 andreas 178: /* Used in packet_read_poll2() */
179: u_int packlen;
1.159 markus 180:
1.165 andreas 181: /* Used in packet_send2 */
182: int rekeying;
183:
184: /* Used in packet_set_interactive */
185: int set_interactive_called;
186:
187: /* Used in packet_set_maxsize */
188: int set_maxsize_called;
189:
1.161 andreas 190: TAILQ_HEAD(, packet) outgoing;
1.105 markus 191: };
1.161 andreas 192:
1.166 ! andreas 193: static struct session_state *active_state, *backup_state;
1.161 andreas 194:
195: static struct session_state *
1.164 andreas 196: alloc_session_state(void)
1.161 andreas 197: {
198: struct session_state *s = xcalloc(1, sizeof(*s));
199:
200: s->connection_in = -1;
201: s->connection_out = -1;
202: s->max_packet_size = 32768;
203: s->packet_timeout_ms = -1;
204: return s;
205: }
1.105 markus 206:
1.16 markus 207: /*
208: * Sets the descriptors used for communication. Disables encryption until
209: * packet_set_encryption_key is called.
210: */
1.2 provos 211: void
212: packet_set_connection(int fd_in, int fd_out)
1.1 deraadt 213: {
1.37 markus 214: Cipher *none = cipher_by_name("none");
1.97 deraadt 215:
1.37 markus 216: if (none == NULL)
217: fatal("packet_set_connection: cannot load cipher 'none'");
1.161 andreas 218: if (active_state == NULL)
219: active_state = alloc_session_state();
220: active_state->connection_in = fd_in;
221: active_state->connection_out = fd_out;
222: cipher_init(&active_state->send_context, none, (const u_char *)"",
1.113 deraadt 223: 0, NULL, 0, CIPHER_ENCRYPT);
1.161 andreas 224: cipher_init(&active_state->receive_context, none, (const u_char *)"",
1.113 deraadt 225: 0, NULL, 0, CIPHER_DECRYPT);
1.161 andreas 226: active_state->newkeys[MODE_IN] = active_state->newkeys[MODE_OUT] = NULL;
227: if (!active_state->initialized) {
228: active_state->initialized = 1;
229: buffer_init(&active_state->input);
230: buffer_init(&active_state->output);
231: buffer_init(&active_state->outgoing_packet);
232: buffer_init(&active_state->incoming_packet);
233: TAILQ_INIT(&active_state->outgoing);
234: active_state->p_send.packets = active_state->p_read.packets = 0;
1.14 markus 235: }
1.1 deraadt 236: }
237:
1.154 dtucker 238: void
239: packet_set_timeout(int timeout, int count)
240: {
241: if (timeout == 0 || count == 0) {
1.161 andreas 242: active_state->packet_timeout_ms = -1;
1.154 dtucker 243: return;
244: }
245: if ((INT_MAX / 1000) / count < timeout)
1.161 andreas 246: active_state->packet_timeout_ms = INT_MAX;
1.154 dtucker 247: else
1.161 andreas 248: active_state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 249: }
250:
1.159 markus 251: static void
252: packet_stop_discard(void)
253: {
1.161 andreas 254: if (active_state->packet_discard_mac) {
1.159 markus 255: char buf[1024];
256:
257: memset(buf, 'a', sizeof(buf));
1.161 andreas 258: while (buffer_len(&active_state->incoming_packet) <
259: PACKET_MAX_SIZE)
260: buffer_append(&active_state->incoming_packet, buf,
261: sizeof(buf));
262: (void) mac_compute(active_state->packet_discard_mac,
263: active_state->p_read.seqnr,
264: buffer_ptr(&active_state->incoming_packet),
1.159 markus 265: PACKET_MAX_SIZE);
266: }
267: logit("Finished discarding for %.200s", get_remote_ipaddr());
268: cleanup_exit(255);
269: }
270:
271: static void
272: packet_start_discard(Enc *enc, Mac *mac, u_int packet_length, u_int discard)
273: {
1.160 markus 274: if (enc == NULL || !cipher_is_cbc(enc->cipher))
1.159 markus 275: packet_disconnect("Packet corrupt");
276: if (packet_length != PACKET_MAX_SIZE && mac && mac->enabled)
1.161 andreas 277: active_state->packet_discard_mac = mac;
278: if (buffer_len(&active_state->input) >= discard)
1.159 markus 279: packet_stop_discard();
1.161 andreas 280: active_state->packet_discard = discard -
281: buffer_len(&active_state->input);
1.159 markus 282: }
283:
1.19 markus 284: /* Returns 1 if remote host is connected via socket, 0 if not. */
285:
286: int
1.73 itojun 287: packet_connection_is_on_socket(void)
1.19 markus 288: {
289: struct sockaddr_storage from, to;
290: socklen_t fromlen, tolen;
291:
292: /* filedescriptors in and out are the same, so it's a socket */
1.161 andreas 293: if (active_state->connection_in == active_state->connection_out)
1.19 markus 294: return 1;
295: fromlen = sizeof(from);
296: memset(&from, 0, sizeof(from));
1.161 andreas 297: if (getpeername(active_state->connection_in, (struct sockaddr *)&from,
298: &fromlen) < 0)
1.19 markus 299: return 0;
300: tolen = sizeof(to);
301: memset(&to, 0, sizeof(to));
1.161 andreas 302: if (getpeername(active_state->connection_out, (struct sockaddr *)&to,
303: &tolen) < 0)
1.19 markus 304: return 0;
305: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
306: return 0;
307: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
308: return 0;
309: return 1;
310: }
311:
1.92 markus 312: /*
1.91 markus 313: * Exports an IV from the CipherContext required to export the key
314: * state back from the unprivileged child to the privileged parent
315: * process.
316: */
317:
318: void
319: packet_get_keyiv(int mode, u_char *iv, u_int len)
320: {
321: CipherContext *cc;
322:
323: if (mode == MODE_OUT)
1.161 andreas 324: cc = &active_state->send_context;
1.91 markus 325: else
1.161 andreas 326: cc = &active_state->receive_context;
1.91 markus 327:
328: cipher_get_keyiv(cc, iv, len);
329: }
330:
331: int
332: packet_get_keycontext(int mode, u_char *dat)
333: {
334: CipherContext *cc;
1.92 markus 335:
1.91 markus 336: if (mode == MODE_OUT)
1.161 andreas 337: cc = &active_state->send_context;
1.91 markus 338: else
1.161 andreas 339: cc = &active_state->receive_context;
1.91 markus 340:
341: return (cipher_get_keycontext(cc, dat));
342: }
343:
344: void
345: packet_set_keycontext(int mode, u_char *dat)
346: {
347: CipherContext *cc;
1.92 markus 348:
1.91 markus 349: if (mode == MODE_OUT)
1.161 andreas 350: cc = &active_state->send_context;
1.91 markus 351: else
1.161 andreas 352: cc = &active_state->receive_context;
1.91 markus 353:
354: cipher_set_keycontext(cc, dat);
355: }
356:
357: int
358: packet_get_keyiv_len(int mode)
359: {
360: CipherContext *cc;
361:
362: if (mode == MODE_OUT)
1.161 andreas 363: cc = &active_state->send_context;
1.91 markus 364: else
1.161 andreas 365: cc = &active_state->receive_context;
1.91 markus 366:
367: return (cipher_get_keyiv_len(cc));
368: }
1.125 deraadt 369:
1.91 markus 370: void
371: packet_set_iv(int mode, u_char *dat)
372: {
373: CipherContext *cc;
374:
375: if (mode == MODE_OUT)
1.161 andreas 376: cc = &active_state->send_context;
1.91 markus 377: else
1.161 andreas 378: cc = &active_state->receive_context;
1.91 markus 379:
380: cipher_set_keyiv(cc, dat);
381: }
1.125 deraadt 382:
1.91 markus 383: int
1.107 deraadt 384: packet_get_ssh1_cipher(void)
1.91 markus 385: {
1.161 andreas 386: return (cipher_get_number(active_state->receive_context.cipher));
1.91 markus 387: }
388:
1.105 markus 389: void
1.157 markus 390: packet_get_state(int mode, u_int32_t *seqnr, u_int64_t *blocks, u_int32_t *packets,
391: u_int64_t *bytes)
1.105 markus 392: {
393: struct packet_state *state;
1.104 markus 394:
1.161 andreas 395: state = (mode == MODE_IN) ?
396: &active_state->p_read : &active_state->p_send;
1.157 markus 397: if (seqnr)
398: *seqnr = state->seqnr;
399: if (blocks)
400: *blocks = state->blocks;
401: if (packets)
402: *packets = state->packets;
403: if (bytes)
404: *bytes = state->bytes;
1.91 markus 405: }
406:
407: void
1.157 markus 408: packet_set_state(int mode, u_int32_t seqnr, u_int64_t blocks, u_int32_t packets,
409: u_int64_t bytes)
1.91 markus 410: {
1.105 markus 411: struct packet_state *state;
412:
1.161 andreas 413: state = (mode == MODE_IN) ?
414: &active_state->p_read : &active_state->p_send;
1.105 markus 415: state->seqnr = seqnr;
416: state->blocks = blocks;
417: state->packets = packets;
1.157 markus 418: state->bytes = bytes;
1.91 markus 419: }
420:
1.19 markus 421: /* returns 1 if connection is via ipv4 */
422:
423: int
1.73 itojun 424: packet_connection_is_ipv4(void)
1.19 markus 425: {
426: struct sockaddr_storage to;
1.21 deraadt 427: socklen_t tolen = sizeof(to);
1.19 markus 428:
429: memset(&to, 0, sizeof(to));
1.161 andreas 430: if (getsockname(active_state->connection_out, (struct sockaddr *)&to,
431: &tolen) < 0)
1.19 markus 432: return 0;
433: if (to.ss_family != AF_INET)
434: return 0;
435: return 1;
436: }
437:
1.1 deraadt 438: /* Sets the connection into non-blocking mode. */
439:
1.2 provos 440: void
1.73 itojun 441: packet_set_nonblocking(void)
1.1 deraadt 442: {
1.14 markus 443: /* Set the socket into non-blocking mode. */
1.161 andreas 444: set_nonblock(active_state->connection_in);
1.14 markus 445:
1.161 andreas 446: if (active_state->connection_out != active_state->connection_in)
447: set_nonblock(active_state->connection_out);
1.1 deraadt 448: }
449:
450: /* Returns the socket used for reading. */
451:
1.2 provos 452: int
1.73 itojun 453: packet_get_connection_in(void)
1.1 deraadt 454: {
1.161 andreas 455: return active_state->connection_in;
1.1 deraadt 456: }
457:
458: /* Returns the descriptor used for writing. */
459:
1.2 provos 460: int
1.73 itojun 461: packet_get_connection_out(void)
1.1 deraadt 462: {
1.161 andreas 463: return active_state->connection_out;
1.1 deraadt 464: }
465:
466: /* Closes the connection and clears and frees internal data structures. */
467:
1.2 provos 468: void
1.73 itojun 469: packet_close(void)
1.1 deraadt 470: {
1.161 andreas 471: if (!active_state->initialized)
1.14 markus 472: return;
1.161 andreas 473: active_state->initialized = 0;
474: if (active_state->connection_in == active_state->connection_out) {
475: shutdown(active_state->connection_out, SHUT_RDWR);
476: close(active_state->connection_out);
1.14 markus 477: } else {
1.161 andreas 478: close(active_state->connection_in);
479: close(active_state->connection_out);
1.14 markus 480: }
1.161 andreas 481: buffer_free(&active_state->input);
482: buffer_free(&active_state->output);
483: buffer_free(&active_state->outgoing_packet);
484: buffer_free(&active_state->incoming_packet);
485: if (active_state->compression_buffer_ready) {
486: buffer_free(&active_state->compression_buffer);
1.14 markus 487: buffer_compress_uninit();
488: }
1.161 andreas 489: cipher_cleanup(&active_state->send_context);
490: cipher_cleanup(&active_state->receive_context);
1.1 deraadt 491: }
492:
493: /* Sets remote side protocol flags. */
494:
1.2 provos 495: void
1.40 markus 496: packet_set_protocol_flags(u_int protocol_flags)
1.1 deraadt 497: {
1.161 andreas 498: active_state->remote_protocol_flags = protocol_flags;
1.1 deraadt 499: }
500:
501: /* Returns the remote protocol flags set earlier by the above function. */
502:
1.40 markus 503: u_int
1.73 itojun 504: packet_get_protocol_flags(void)
1.1 deraadt 505: {
1.161 andreas 506: return active_state->remote_protocol_flags;
1.1 deraadt 507: }
508:
1.16 markus 509: /*
510: * Starts packet compression from the next packet on in both directions.
511: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
512: */
1.1 deraadt 513:
1.68 itojun 514: static void
515: packet_init_compression(void)
1.60 markus 516: {
1.161 andreas 517: if (active_state->compression_buffer_ready == 1)
1.60 markus 518: return;
1.161 andreas 519: active_state->compression_buffer_ready = 1;
520: buffer_init(&active_state->compression_buffer);
1.60 markus 521: }
522:
1.2 provos 523: void
524: packet_start_compression(int level)
1.1 deraadt 525: {
1.161 andreas 526: if (active_state->packet_compression && !compat20)
1.14 markus 527: fatal("Compression already enabled.");
1.161 andreas 528: active_state->packet_compression = 1;
1.60 markus 529: packet_init_compression();
530: buffer_compress_init_send(level);
531: buffer_compress_init_recv();
1.1 deraadt 532: }
533:
1.16 markus 534: /*
535: * Causes any further packets to be encrypted using the given key. The same
536: * key is used for both sending and reception. However, both directions are
537: * encrypted independently of each other.
538: */
1.95 markus 539:
1.2 provos 540: void
1.40 markus 541: packet_set_encryption_key(const u_char *key, u_int keylen,
1.37 markus 542: int number)
1.1 deraadt 543: {
1.37 markus 544: Cipher *cipher = cipher_by_number(number);
1.97 deraadt 545:
1.37 markus 546: if (cipher == NULL)
547: fatal("packet_set_encryption_key: unknown cipher number %d", number);
1.25 markus 548: if (keylen < 20)
1.37 markus 549: fatal("packet_set_encryption_key: keylen too small: %d", keylen);
1.95 markus 550: if (keylen > SSH_SESSION_KEY_LENGTH)
551: fatal("packet_set_encryption_key: keylen too big: %d", keylen);
1.161 andreas 552: memcpy(active_state->ssh1_key, key, keylen);
553: active_state->ssh1_keylen = keylen;
554: cipher_init(&active_state->send_context, cipher, key, keylen, NULL,
555: 0, CIPHER_ENCRYPT);
556: cipher_init(&active_state->receive_context, cipher, key, keylen, NULL,
557: 0, CIPHER_DECRYPT);
1.95 markus 558: }
559:
560: u_int
561: packet_get_encryption_key(u_char *key)
562: {
563: if (key == NULL)
1.161 andreas 564: return (active_state->ssh1_keylen);
565: memcpy(key, active_state->ssh1_key, active_state->ssh1_keylen);
566: return (active_state->ssh1_keylen);
1.1 deraadt 567: }
568:
1.62 markus 569: /* Start constructing a packet to send. */
1.2 provos 570: void
1.62 markus 571: packet_start(u_char type)
1.1 deraadt 572: {
1.62 markus 573: u_char buf[9];
574: int len;
1.1 deraadt 575:
1.62 markus 576: DBG(debug("packet_start[%d]", type));
577: len = compat20 ? 6 : 9;
578: memset(buf, 0, len - 1);
579: buf[len - 1] = type;
1.161 andreas 580: buffer_clear(&active_state->outgoing_packet);
581: buffer_append(&active_state->outgoing_packet, buf, len);
1.25 markus 582: }
583:
1.62 markus 584: /* Append payload. */
1.2 provos 585: void
586: packet_put_char(int value)
1.1 deraadt 587: {
1.14 markus 588: char ch = value;
1.97 deraadt 589:
1.161 andreas 590: buffer_append(&active_state->outgoing_packet, &ch, 1);
1.1 deraadt 591: }
1.125 deraadt 592:
1.2 provos 593: void
1.40 markus 594: packet_put_int(u_int value)
1.1 deraadt 595: {
1.161 andreas 596: buffer_put_int(&active_state->outgoing_packet, value);
1.1 deraadt 597: }
1.125 deraadt 598:
1.2 provos 599: void
1.162 andreas 600: packet_put_int64(u_int64_t value)
601: {
602: buffer_put_int64(&active_state->outgoing_packet, value);
603: }
604:
605: void
1.76 stevesk 606: packet_put_string(const void *buf, u_int len)
1.1 deraadt 607: {
1.161 andreas 608: buffer_put_string(&active_state->outgoing_packet, buf, len);
1.1 deraadt 609: }
1.125 deraadt 610:
1.24 markus 611: void
612: packet_put_cstring(const char *str)
613: {
1.161 andreas 614: buffer_put_cstring(&active_state->outgoing_packet, str);
1.24 markus 615: }
1.125 deraadt 616:
1.24 markus 617: void
1.76 stevesk 618: packet_put_raw(const void *buf, u_int len)
1.24 markus 619: {
1.161 andreas 620: buffer_append(&active_state->outgoing_packet, buf, len);
1.24 markus 621: }
1.125 deraadt 622:
1.2 provos 623: void
1.14 markus 624: packet_put_bignum(BIGNUM * value)
1.1 deraadt 625: {
1.161 andreas 626: buffer_put_bignum(&active_state->outgoing_packet, value);
1.1 deraadt 627: }
1.125 deraadt 628:
1.24 markus 629: void
630: packet_put_bignum2(BIGNUM * value)
631: {
1.161 andreas 632: buffer_put_bignum2(&active_state->outgoing_packet, value);
1.24 markus 633: }
1.1 deraadt 634:
1.16 markus 635: /*
636: * Finalizes and sends the packet. If the encryption key has been set,
637: * encrypts the packet before sending.
638: */
1.14 markus 639:
1.68 itojun 640: static void
1.49 itojun 641: packet_send1(void)
1.1 deraadt 642: {
1.89 markus 643: u_char buf[8], *cp;
1.14 markus 644: int i, padding, len;
1.40 markus 645: u_int checksum;
1.115 avsm 646: u_int32_t rnd = 0;
1.14 markus 647:
1.16 markus 648: /*
649: * If using packet compression, compress the payload of the outgoing
650: * packet.
651: */
1.161 andreas 652: if (active_state->packet_compression) {
653: buffer_clear(&active_state->compression_buffer);
1.14 markus 654: /* Skip padding. */
1.161 andreas 655: buffer_consume(&active_state->outgoing_packet, 8);
1.14 markus 656: /* padding */
1.161 andreas 657: buffer_append(&active_state->compression_buffer,
658: "\0\0\0\0\0\0\0\0", 8);
659: buffer_compress(&active_state->outgoing_packet,
660: &active_state->compression_buffer);
661: buffer_clear(&active_state->outgoing_packet);
662: buffer_append(&active_state->outgoing_packet,
663: buffer_ptr(&active_state->compression_buffer),
664: buffer_len(&active_state->compression_buffer));
1.14 markus 665: }
666: /* Compute packet length without padding (add checksum, remove padding). */
1.161 andreas 667: len = buffer_len(&active_state->outgoing_packet) + 4 - 8;
1.14 markus 668:
1.32 markus 669: /* Insert padding. Initialized to zero in packet_start1() */
1.14 markus 670: padding = 8 - len % 8;
1.161 andreas 671: if (!active_state->send_context.plaintext) {
672: cp = buffer_ptr(&active_state->outgoing_packet);
1.14 markus 673: for (i = 0; i < padding; i++) {
674: if (i % 4 == 0)
1.115 avsm 675: rnd = arc4random();
676: cp[7 - i] = rnd & 0xff;
677: rnd >>= 8;
1.14 markus 678: }
679: }
1.161 andreas 680: buffer_consume(&active_state->outgoing_packet, 8 - padding);
1.14 markus 681:
682: /* Add check bytes. */
1.161 andreas 683: checksum = ssh_crc32(buffer_ptr(&active_state->outgoing_packet),
684: buffer_len(&active_state->outgoing_packet));
1.131 djm 685: put_u32(buf, checksum);
1.161 andreas 686: buffer_append(&active_state->outgoing_packet, buf, 4);
1.1 deraadt 687:
688: #ifdef PACKET_DEBUG
1.14 markus 689: fprintf(stderr, "packet_send plain: ");
1.161 andreas 690: buffer_dump(&active_state->outgoing_packet);
1.1 deraadt 691: #endif
692:
1.14 markus 693: /* Append to output. */
1.131 djm 694: put_u32(buf, len);
1.161 andreas 695: buffer_append(&active_state->output, buf, 4);
696: cp = buffer_append_space(&active_state->output,
697: buffer_len(&active_state->outgoing_packet));
698: cipher_crypt(&active_state->send_context, cp,
699: buffer_ptr(&active_state->outgoing_packet),
700: buffer_len(&active_state->outgoing_packet));
1.14 markus 701:
1.1 deraadt 702: #ifdef PACKET_DEBUG
1.14 markus 703: fprintf(stderr, "encrypted: ");
1.161 andreas 704: buffer_dump(&active_state->output);
1.1 deraadt 705: #endif
1.161 andreas 706: active_state->p_send.packets++;
707: active_state->p_send.bytes += len +
708: buffer_len(&active_state->outgoing_packet);
709: buffer_clear(&active_state->outgoing_packet);
1.1 deraadt 710:
1.16 markus 711: /*
1.120 djm 712: * Note that the packet is now only buffered in output. It won't be
1.16 markus 713: * actually sent until packet_write_wait or packet_write_poll is
714: * called.
715: */
1.1 deraadt 716: }
717:
1.91 markus 718: void
1.57 markus 719: set_newkeys(int mode)
720: {
721: Enc *enc;
722: Mac *mac;
723: Comp *comp;
724: CipherContext *cc;
1.105 markus 725: u_int64_t *max_blocks;
1.115 avsm 726: int crypt_type;
1.57 markus 727:
1.100 markus 728: debug2("set_newkeys: mode %d", mode);
1.57 markus 729:
1.88 markus 730: if (mode == MODE_OUT) {
1.161 andreas 731: cc = &active_state->send_context;
1.115 avsm 732: crypt_type = CIPHER_ENCRYPT;
1.161 andreas 733: active_state->p_send.packets = active_state->p_send.blocks = 0;
734: max_blocks = &active_state->max_blocks_out;
1.88 markus 735: } else {
1.161 andreas 736: cc = &active_state->receive_context;
1.115 avsm 737: crypt_type = CIPHER_DECRYPT;
1.161 andreas 738: active_state->p_read.packets = active_state->p_read.blocks = 0;
739: max_blocks = &active_state->max_blocks_in;
1.88 markus 740: }
1.161 andreas 741: if (active_state->newkeys[mode] != NULL) {
1.100 markus 742: debug("set_newkeys: rekeying");
1.88 markus 743: cipher_cleanup(cc);
1.161 andreas 744: enc = &active_state->newkeys[mode]->enc;
745: mac = &active_state->newkeys[mode]->mac;
746: comp = &active_state->newkeys[mode]->comp;
1.148 pvalchev 747: mac_clear(mac);
1.59 markus 748: xfree(enc->name);
749: xfree(enc->iv);
750: xfree(enc->key);
751: xfree(mac->name);
752: xfree(mac->key);
753: xfree(comp->name);
1.161 andreas 754: xfree(active_state->newkeys[mode]);
1.57 markus 755: }
1.161 andreas 756: active_state->newkeys[mode] = kex_get_newkeys(mode);
757: if (active_state->newkeys[mode] == NULL)
1.57 markus 758: fatal("newkeys: no keys for mode %d", mode);
1.161 andreas 759: enc = &active_state->newkeys[mode]->enc;
760: mac = &active_state->newkeys[mode]->mac;
761: comp = &active_state->newkeys[mode]->comp;
1.148 pvalchev 762: if (mac_init(mac) == 0)
1.57 markus 763: mac->enabled = 1;
764: DBG(debug("cipher_init_context: %d", mode));
1.88 markus 765: cipher_init(cc, enc->cipher, enc->key, enc->key_len,
1.115 avsm 766: enc->iv, enc->block_size, crypt_type);
1.91 markus 767: /* Deleting the keys does not gain extra security */
768: /* memset(enc->iv, 0, enc->block_size);
1.147 djm 769: memset(enc->key, 0, enc->key_len);
770: memset(mac->key, 0, mac->key_len); */
1.118 markus 771: if ((comp->type == COMP_ZLIB ||
1.161 andreas 772: (comp->type == COMP_DELAYED &&
773: active_state->after_authentication)) && comp->enabled == 0) {
1.60 markus 774: packet_init_compression();
775: if (mode == MODE_OUT)
776: buffer_compress_init_send(6);
777: else
778: buffer_compress_init_recv();
1.57 markus 779: comp->enabled = 1;
780: }
1.109 markus 781: /*
782: * The 2^(blocksize*2) limit is too expensive for 3DES,
783: * blowfish, etc, so enforce a 1GB limit for small blocksizes.
784: */
785: if (enc->block_size >= 16)
786: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
787: else
788: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.161 andreas 789: if (active_state->rekey_limit)
790: *max_blocks = MIN(*max_blocks,
791: active_state->rekey_limit / enc->block_size);
1.57 markus 792: }
793:
1.16 markus 794: /*
1.118 markus 795: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 796: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 797: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
798: */
799: static void
800: packet_enable_delayed_compress(void)
801: {
802: Comp *comp = NULL;
803: int mode;
804:
805: /*
806: * Remember that we are past the authentication step, so rekeying
807: * with COMP_DELAYED will turn on compression immediately.
808: */
1.161 andreas 809: active_state->after_authentication = 1;
1.118 markus 810: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 811: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.161 andreas 812: if (active_state->newkeys[mode] == NULL)
1.145 markus 813: continue;
1.161 andreas 814: comp = &active_state->newkeys[mode]->comp;
1.118 markus 815: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.119 markus 816: packet_init_compression();
1.118 markus 817: if (mode == MODE_OUT)
818: buffer_compress_init_send(6);
819: else
820: buffer_compress_init_recv();
821: comp->enabled = 1;
822: }
823: }
824: }
825:
826: /*
1.25 markus 827: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
828: */
1.68 itojun 829: static void
1.105 markus 830: packet_send2_wrapped(void)
1.25 markus 831: {
1.89 markus 832: u_char type, *cp, *macbuf = NULL;
1.71 markus 833: u_char padlen, pad;
1.40 markus 834: u_int packet_length = 0;
1.71 markus 835: u_int i, len;
1.115 avsm 836: u_int32_t rnd = 0;
1.25 markus 837: Enc *enc = NULL;
838: Mac *mac = NULL;
839: Comp *comp = NULL;
840: int block_size;
841:
1.161 andreas 842: if (active_state->newkeys[MODE_OUT] != NULL) {
843: enc = &active_state->newkeys[MODE_OUT]->enc;
844: mac = &active_state->newkeys[MODE_OUT]->mac;
845: comp = &active_state->newkeys[MODE_OUT]->comp;
1.25 markus 846: }
1.88 markus 847: block_size = enc ? enc->block_size : 8;
1.25 markus 848:
1.161 andreas 849: cp = buffer_ptr(&active_state->outgoing_packet);
1.89 markus 850: type = cp[5];
1.25 markus 851:
852: #ifdef PACKET_DEBUG
853: fprintf(stderr, "plain: ");
1.161 andreas 854: buffer_dump(&active_state->outgoing_packet);
1.25 markus 855: #endif
856:
857: if (comp && comp->enabled) {
1.161 andreas 858: len = buffer_len(&active_state->outgoing_packet);
1.25 markus 859: /* skip header, compress only payload */
1.161 andreas 860: buffer_consume(&active_state->outgoing_packet, 5);
861: buffer_clear(&active_state->compression_buffer);
862: buffer_compress(&active_state->outgoing_packet,
863: &active_state->compression_buffer);
864: buffer_clear(&active_state->outgoing_packet);
865: buffer_append(&active_state->outgoing_packet, "\0\0\0\0\0", 5);
866: buffer_append(&active_state->outgoing_packet,
867: buffer_ptr(&active_state->compression_buffer),
868: buffer_len(&active_state->compression_buffer));
1.25 markus 869: DBG(debug("compression: raw %d compressed %d", len,
1.161 andreas 870: buffer_len(&active_state->outgoing_packet)));
1.25 markus 871: }
872:
873: /* sizeof (packet_len + pad_len + payload) */
1.161 andreas 874: len = buffer_len(&active_state->outgoing_packet);
1.25 markus 875:
876: /*
877: * calc size of padding, alloc space, get random data,
878: * minimum padding is 4 bytes
879: */
880: padlen = block_size - (len % block_size);
881: if (padlen < 4)
882: padlen += block_size;
1.161 andreas 883: if (active_state->extra_pad) {
1.71 markus 884: /* will wrap if extra_pad+padlen > 255 */
1.161 andreas 885: active_state->extra_pad =
886: roundup(active_state->extra_pad, block_size);
887: pad = active_state->extra_pad -
888: ((len + padlen) % active_state->extra_pad);
1.93 markus 889: debug3("packet_send2: adding %d (len %d padlen %d extra_pad %d)",
1.161 andreas 890: pad, len, padlen, active_state->extra_pad);
1.71 markus 891: padlen += pad;
1.161 andreas 892: active_state->extra_pad = 0;
1.71 markus 893: }
1.161 andreas 894: cp = buffer_append_space(&active_state->outgoing_packet, padlen);
895: if (enc && !active_state->send_context.plaintext) {
1.32 markus 896: /* random padding */
1.25 markus 897: for (i = 0; i < padlen; i++) {
898: if (i % 4 == 0)
1.115 avsm 899: rnd = arc4random();
900: cp[i] = rnd & 0xff;
901: rnd >>= 8;
1.25 markus 902: }
1.32 markus 903: } else {
904: /* clear padding */
905: memset(cp, 0, padlen);
1.25 markus 906: }
907: /* packet_length includes payload, padding and padding length field */
1.161 andreas 908: packet_length = buffer_len(&active_state->outgoing_packet) - 4;
909: cp = buffer_ptr(&active_state->outgoing_packet);
1.131 djm 910: put_u32(cp, packet_length);
1.89 markus 911: cp[4] = padlen;
1.25 markus 912: DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen));
913:
914: /* compute MAC over seqnr and packet(length fields, payload, padding) */
915: if (mac && mac->enabled) {
1.161 andreas 916: macbuf = mac_compute(mac, active_state->p_send.seqnr,
917: buffer_ptr(&active_state->outgoing_packet),
918: buffer_len(&active_state->outgoing_packet));
919: DBG(debug("done calc MAC out #%d", active_state->p_send.seqnr));
1.25 markus 920: }
921: /* encrypt packet and append to output buffer. */
1.161 andreas 922: cp = buffer_append_space(&active_state->output,
923: buffer_len(&active_state->outgoing_packet));
924: cipher_crypt(&active_state->send_context, cp,
925: buffer_ptr(&active_state->outgoing_packet),
926: buffer_len(&active_state->outgoing_packet));
1.25 markus 927: /* append unencrypted MAC */
928: if (mac && mac->enabled)
1.161 andreas 929: buffer_append(&active_state->output, macbuf, mac->mac_len);
1.25 markus 930: #ifdef PACKET_DEBUG
931: fprintf(stderr, "encrypted: ");
1.161 andreas 932: buffer_dump(&active_state->output);
1.25 markus 933: #endif
1.29 markus 934: /* increment sequence number for outgoing packets */
1.161 andreas 935: if (++active_state->p_send.seqnr == 0)
1.106 itojun 936: logit("outgoing seqnr wraps around");
1.161 andreas 937: if (++active_state->p_send.packets == 0)
1.105 markus 938: if (!(datafellows & SSH_BUG_NOREKEY))
939: fatal("XXX too many packets with same key");
1.161 andreas 940: active_state->p_send.blocks += (packet_length + 4) / block_size;
941: active_state->p_send.bytes += packet_length + 4;
942: buffer_clear(&active_state->outgoing_packet);
1.25 markus 943:
1.57 markus 944: if (type == SSH2_MSG_NEWKEYS)
945: set_newkeys(MODE_OUT);
1.161 andreas 946: else if (type == SSH2_MSG_USERAUTH_SUCCESS && active_state->server_side)
1.118 markus 947: packet_enable_delayed_compress();
1.25 markus 948: }
949:
1.105 markus 950: static void
951: packet_send2(void)
952: {
953: struct packet *p;
954: u_char type, *cp;
955:
1.161 andreas 956: cp = buffer_ptr(&active_state->outgoing_packet);
1.105 markus 957: type = cp[5];
958:
959: /* during rekeying we can only send key exchange messages */
1.165 andreas 960: if (active_state->rekeying) {
1.105 markus 961: if (!((type >= SSH2_MSG_TRANSPORT_MIN) &&
962: (type <= SSH2_MSG_TRANSPORT_MAX))) {
963: debug("enqueue packet: %u", type);
964: p = xmalloc(sizeof(*p));
965: p->type = type;
1.161 andreas 966: memcpy(&p->payload, &active_state->outgoing_packet,
967: sizeof(Buffer));
968: buffer_init(&active_state->outgoing_packet);
969: TAILQ_INSERT_TAIL(&active_state->outgoing, p, next);
1.105 markus 970: return;
971: }
972: }
973:
974: /* rekeying starts with sending KEXINIT */
975: if (type == SSH2_MSG_KEXINIT)
1.165 andreas 976: active_state->rekeying = 1;
1.105 markus 977:
978: packet_send2_wrapped();
979:
980: /* after a NEWKEYS message we can send the complete queue */
981: if (type == SSH2_MSG_NEWKEYS) {
1.165 andreas 982: active_state->rekeying = 0;
1.161 andreas 983: while ((p = TAILQ_FIRST(&active_state->outgoing))) {
1.105 markus 984: type = p->type;
985: debug("dequeue packet: %u", type);
1.161 andreas 986: buffer_free(&active_state->outgoing_packet);
987: memcpy(&active_state->outgoing_packet, &p->payload,
1.105 markus 988: sizeof(Buffer));
1.161 andreas 989: TAILQ_REMOVE(&active_state->outgoing, p, next);
1.105 markus 990: xfree(p);
991: packet_send2_wrapped();
992: }
993: }
994: }
995:
1.25 markus 996: void
1.73 itojun 997: packet_send(void)
1.25 markus 998: {
1.62 markus 999: if (compat20)
1.25 markus 1000: packet_send2();
1001: else
1002: packet_send1();
1003: DBG(debug("packet_send done"));
1004: }
1005:
1006: /*
1.16 markus 1007: * Waits until a packet has been received, and returns its type. Note that
1008: * no other data is processed until this returns, so this function should not
1009: * be used during the interactive session.
1010: */
1.1 deraadt 1011:
1.2 provos 1012: int
1.82 markus 1013: packet_read_seqnr(u_int32_t *seqnr_p)
1.1 deraadt 1014: {
1.163 andreas 1015: int type, len, ret, ms_remain, cont;
1.56 millert 1016: fd_set *setp;
1.14 markus 1017: char buf[8192];
1.155 deraadt 1018: struct timeval timeout, start, *timeoutp = NULL;
1019:
1.25 markus 1020: DBG(debug("packet_read()"));
1.14 markus 1021:
1.161 andreas 1022: setp = (fd_set *)xcalloc(howmany(active_state->connection_in + 1,
1023: NFDBITS), sizeof(fd_mask));
1.56 millert 1024:
1.14 markus 1025: /* Since we are blocking, ensure that all written packets have been sent. */
1026: packet_write_wait();
1027:
1028: /* Stay in the loop until we have received a complete packet. */
1029: for (;;) {
1030: /* Try to read a packet from the buffer. */
1.82 markus 1031: type = packet_read_poll_seqnr(seqnr_p);
1.62 markus 1032: if (!compat20 && (
1.32 markus 1033: type == SSH_SMSG_SUCCESS
1.14 markus 1034: || type == SSH_SMSG_FAILURE
1035: || type == SSH_CMSG_EOF
1.32 markus 1036: || type == SSH_CMSG_EXIT_CONFIRMATION))
1.79 markus 1037: packet_check_eom();
1.14 markus 1038: /* If we got a packet, return it. */
1.56 millert 1039: if (type != SSH_MSG_NONE) {
1040: xfree(setp);
1.14 markus 1041: return type;
1.56 millert 1042: }
1.16 markus 1043: /*
1044: * Otherwise, wait for some data to arrive, add it to the
1045: * buffer, and try again.
1046: */
1.161 andreas 1047: memset(setp, 0, howmany(active_state->connection_in + 1,
1048: NFDBITS) * sizeof(fd_mask));
1049: FD_SET(active_state->connection_in, setp);
1.16 markus 1050:
1.161 andreas 1051: if (active_state->packet_timeout_ms > 0) {
1052: ms_remain = active_state->packet_timeout_ms;
1.154 dtucker 1053: timeoutp = &timeout;
1054: }
1.14 markus 1055: /* Wait for some data to arrive. */
1.154 dtucker 1056: for (;;) {
1.161 andreas 1057: if (active_state->packet_timeout_ms != -1) {
1.154 dtucker 1058: ms_to_timeval(&timeout, ms_remain);
1059: gettimeofday(&start, NULL);
1060: }
1.161 andreas 1061: if ((ret = select(active_state->connection_in + 1, setp,
1062: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1063: break;
1.161 andreas 1064: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1065: break;
1.161 andreas 1066: if (active_state->packet_timeout_ms == -1)
1.154 dtucker 1067: continue;
1068: ms_subtract_diff(&start, &ms_remain);
1069: if (ms_remain <= 0) {
1070: ret = 0;
1071: break;
1072: }
1073: }
1074: if (ret == 0) {
1075: logit("Connection to %.200s timed out while "
1076: "waiting to read", get_remote_ipaddr());
1077: cleanup_exit(255);
1078: }
1.14 markus 1079: /* Read data from the socket. */
1.163 andreas 1080: do {
1081: cont = 0;
1082: len = roaming_read(active_state->connection_in, buf,
1083: sizeof(buf), &cont);
1084: } while (len == 0 && cont);
1.18 markus 1085: if (len == 0) {
1.106 itojun 1086: logit("Connection closed by %.200s", get_remote_ipaddr());
1.112 markus 1087: cleanup_exit(255);
1.18 markus 1088: }
1.14 markus 1089: if (len < 0)
1090: fatal("Read from socket failed: %.100s", strerror(errno));
1091: /* Append it to the buffer. */
1092: packet_process_incoming(buf, len);
1093: }
1094: /* NOTREACHED */
1.1 deraadt 1095: }
1096:
1.77 djm 1097: int
1.82 markus 1098: packet_read(void)
1.77 djm 1099: {
1.82 markus 1100: return packet_read_seqnr(NULL);
1.77 djm 1101: }
1102:
1.16 markus 1103: /*
1104: * Waits until a packet has been received, verifies that its type matches
1105: * that given, and gives a fatal error and exits if there is a mismatch.
1106: */
1.1 deraadt 1107:
1.2 provos 1108: void
1.82 markus 1109: packet_read_expect(int expected_type)
1.1 deraadt 1110: {
1.14 markus 1111: int type;
1.1 deraadt 1112:
1.82 markus 1113: type = packet_read();
1.14 markus 1114: if (type != expected_type)
1115: packet_disconnect("Protocol error: expected packet type %d, got %d",
1.25 markus 1116: expected_type, type);
1.1 deraadt 1117: }
1118:
1119: /* Checks if a full packet is available in the data received so far via
1.14 markus 1120: * packet_process_incoming. If so, reads the packet; otherwise returns
1121: * SSH_MSG_NONE. This does not wait for data from the connection.
1122: *
1.150 dtucker 1123: * SSH_MSG_DISCONNECT is handled specially here. Also,
1124: * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1125: * to higher levels.
1.14 markus 1126: */
1.1 deraadt 1127:
1.68 itojun 1128: static int
1.82 markus 1129: packet_read_poll1(void)
1.1 deraadt 1130: {
1.40 markus 1131: u_int len, padded_len;
1.89 markus 1132: u_char *cp, type;
1.40 markus 1133: u_int checksum, stored_checksum;
1.14 markus 1134:
1135: /* Check if input size is less than minimum packet size. */
1.161 andreas 1136: if (buffer_len(&active_state->input) < 4 + 8)
1.14 markus 1137: return SSH_MSG_NONE;
1138: /* Get length of incoming packet. */
1.161 andreas 1139: cp = buffer_ptr(&active_state->input);
1.131 djm 1140: len = get_u32(cp);
1.14 markus 1141: if (len < 1 + 2 + 2 || len > 256 * 1024)
1.98 markus 1142: packet_disconnect("Bad packet length %u.", len);
1.14 markus 1143: padded_len = (len + 8) & ~7;
1144:
1145: /* Check if the packet has been entirely received. */
1.161 andreas 1146: if (buffer_len(&active_state->input) < 4 + padded_len)
1.14 markus 1147: return SSH_MSG_NONE;
1148:
1149: /* The entire packet is in buffer. */
1150:
1151: /* Consume packet length. */
1.161 andreas 1152: buffer_consume(&active_state->input, 4);
1.14 markus 1153:
1.62 markus 1154: /*
1155: * Cryptographic attack detector for ssh
1156: * (C)1998 CORE-SDI, Buenos Aires Argentina
1157: * Ariel Futoransky(futo@core-sdi.com)
1158: */
1.161 andreas 1159: if (!active_state->receive_context.plaintext) {
1160: switch (detect_attack(buffer_ptr(&active_state->input),
1161: padded_len)) {
1.144 djm 1162: case DEATTACK_DETECTED:
1163: packet_disconnect("crc32 compensation attack: "
1164: "network attack detected");
1165: case DEATTACK_DOS_DETECTED:
1166: packet_disconnect("deattack denial of "
1167: "service detected");
1168: }
1169: }
1.62 markus 1170:
1171: /* Decrypt data to incoming_packet. */
1.161 andreas 1172: buffer_clear(&active_state->incoming_packet);
1173: cp = buffer_append_space(&active_state->incoming_packet, padded_len);
1174: cipher_crypt(&active_state->receive_context, cp,
1175: buffer_ptr(&active_state->input), padded_len);
1.62 markus 1176:
1.161 andreas 1177: buffer_consume(&active_state->input, padded_len);
1.1 deraadt 1178:
1179: #ifdef PACKET_DEBUG
1.14 markus 1180: fprintf(stderr, "read_poll plain: ");
1.161 andreas 1181: buffer_dump(&active_state->incoming_packet);
1.1 deraadt 1182: #endif
1183:
1.14 markus 1184: /* Compute packet checksum. */
1.161 andreas 1185: checksum = ssh_crc32(buffer_ptr(&active_state->incoming_packet),
1186: buffer_len(&active_state->incoming_packet) - 4);
1.14 markus 1187:
1188: /* Skip padding. */
1.161 andreas 1189: buffer_consume(&active_state->incoming_packet, 8 - len % 8);
1.14 markus 1190:
1191: /* Test check bytes. */
1.161 andreas 1192: if (len != buffer_len(&active_state->incoming_packet))
1.77 djm 1193: packet_disconnect("packet_read_poll1: len %d != buffer_len %d.",
1.161 andreas 1194: len, buffer_len(&active_state->incoming_packet));
1.14 markus 1195:
1.161 andreas 1196: cp = (u_char *)buffer_ptr(&active_state->incoming_packet) + len - 4;
1.131 djm 1197: stored_checksum = get_u32(cp);
1.14 markus 1198: if (checksum != stored_checksum)
1199: packet_disconnect("Corrupted check bytes on input.");
1.161 andreas 1200: buffer_consume_end(&active_state->incoming_packet, 4);
1.14 markus 1201:
1.161 andreas 1202: if (active_state->packet_compression) {
1203: buffer_clear(&active_state->compression_buffer);
1204: buffer_uncompress(&active_state->incoming_packet,
1205: &active_state->compression_buffer);
1206: buffer_clear(&active_state->incoming_packet);
1207: buffer_append(&active_state->incoming_packet,
1208: buffer_ptr(&active_state->compression_buffer),
1209: buffer_len(&active_state->compression_buffer));
1210: }
1211: active_state->p_read.packets++;
1212: active_state->p_read.bytes += padded_len + 4;
1213: type = buffer_get_char(&active_state->incoming_packet);
1.116 markus 1214: if (type < SSH_MSG_MIN || type > SSH_MSG_MAX)
1215: packet_disconnect("Invalid ssh1 packet type: %d", type);
1.62 markus 1216: return type;
1.1 deraadt 1217: }
1.14 markus 1218:
1.68 itojun 1219: static int
1.82 markus 1220: packet_read_poll2(u_int32_t *seqnr_p)
1.25 markus 1221: {
1.40 markus 1222: u_int padlen, need;
1.89 markus 1223: u_char *macbuf, *cp, type;
1.117 djm 1224: u_int maclen, block_size;
1.25 markus 1225: Enc *enc = NULL;
1226: Mac *mac = NULL;
1227: Comp *comp = NULL;
1228:
1.161 andreas 1229: if (active_state->packet_discard)
1.159 markus 1230: return SSH_MSG_NONE;
1231:
1.161 andreas 1232: if (active_state->newkeys[MODE_IN] != NULL) {
1233: enc = &active_state->newkeys[MODE_IN]->enc;
1234: mac = &active_state->newkeys[MODE_IN]->mac;
1235: comp = &active_state->newkeys[MODE_IN]->comp;
1.25 markus 1236: }
1237: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1238: block_size = enc ? enc->block_size : 8;
1.25 markus 1239:
1.161 andreas 1240: if (active_state->packlen == 0) {
1.25 markus 1241: /*
1242: * check if input size is less than the cipher block size,
1243: * decrypt first block and extract length of incoming packet
1244: */
1.161 andreas 1245: if (buffer_len(&active_state->input) < block_size)
1.25 markus 1246: return SSH_MSG_NONE;
1.161 andreas 1247: buffer_clear(&active_state->incoming_packet);
1248: cp = buffer_append_space(&active_state->incoming_packet,
1.25 markus 1249: block_size);
1.161 andreas 1250: cipher_crypt(&active_state->receive_context, cp,
1251: buffer_ptr(&active_state->input), block_size);
1252: cp = buffer_ptr(&active_state->incoming_packet);
1253: active_state->packlen = get_u32(cp);
1254: if (active_state->packlen < 1 + 4 ||
1255: active_state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1256: #ifdef PACKET_DEBUG
1.161 andreas 1257: buffer_dump(&active_state->incoming_packet);
1.110 markus 1258: #endif
1.161 andreas 1259: logit("Bad packet length %u.", active_state->packlen);
1260: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1261: PACKET_MAX_SIZE);
1262: return SSH_MSG_NONE;
1.25 markus 1263: }
1.161 andreas 1264: DBG(debug("input: packet len %u", active_state->packlen+4));
1265: buffer_consume(&active_state->input, block_size);
1.25 markus 1266: }
1267: /* we have a partial packet of block_size bytes */
1.161 andreas 1268: need = 4 + active_state->packlen - block_size;
1.25 markus 1269: DBG(debug("partial packet %d, need %d, maclen %d", block_size,
1270: need, maclen));
1.158 markus 1271: if (need % block_size != 0) {
1272: logit("padding error: need %d block %d mod %d",
1.25 markus 1273: need, block_size, need % block_size);
1.161 andreas 1274: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1275: PACKET_MAX_SIZE - block_size);
1276: return SSH_MSG_NONE;
1.158 markus 1277: }
1.25 markus 1278: /*
1279: * check if the entire packet has been received and
1280: * decrypt into incoming_packet
1281: */
1.161 andreas 1282: if (buffer_len(&active_state->input) < need + maclen)
1.25 markus 1283: return SSH_MSG_NONE;
1284: #ifdef PACKET_DEBUG
1285: fprintf(stderr, "read_poll enc/full: ");
1.161 andreas 1286: buffer_dump(&active_state->input);
1.25 markus 1287: #endif
1.161 andreas 1288: cp = buffer_append_space(&active_state->incoming_packet, need);
1289: cipher_crypt(&active_state->receive_context, cp,
1290: buffer_ptr(&active_state->input), need);
1291: buffer_consume(&active_state->input, need);
1.25 markus 1292: /*
1293: * compute MAC over seqnr and packet,
1294: * increment sequence number for incoming packet
1295: */
1.29 markus 1296: if (mac && mac->enabled) {
1.161 andreas 1297: macbuf = mac_compute(mac, active_state->p_read.seqnr,
1298: buffer_ptr(&active_state->incoming_packet),
1299: buffer_len(&active_state->incoming_packet));
1300: if (memcmp(macbuf, buffer_ptr(&active_state->input),
1301: mac->mac_len) != 0) {
1.159 markus 1302: logit("Corrupted MAC on input.");
1303: if (need > PACKET_MAX_SIZE)
1304: fatal("internal error need %d", need);
1.161 andreas 1305: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1306: PACKET_MAX_SIZE - need);
1307: return SSH_MSG_NONE;
1308: }
1309:
1.161 andreas 1310: DBG(debug("MAC #%d ok", active_state->p_read.seqnr));
1311: buffer_consume(&active_state->input, mac->mac_len);
1.25 markus 1312: }
1.159 markus 1313: /* XXX now it's safe to use fatal/packet_disconnect */
1.77 djm 1314: if (seqnr_p != NULL)
1.161 andreas 1315: *seqnr_p = active_state->p_read.seqnr;
1316: if (++active_state->p_read.seqnr == 0)
1.106 itojun 1317: logit("incoming seqnr wraps around");
1.161 andreas 1318: if (++active_state->p_read.packets == 0)
1.105 markus 1319: if (!(datafellows & SSH_BUG_NOREKEY))
1320: fatal("XXX too many packets with same key");
1.161 andreas 1321: active_state->p_read.blocks += (active_state->packlen + 4) / block_size;
1322: active_state->p_read.bytes += active_state->packlen + 4;
1.25 markus 1323:
1324: /* get padlen */
1.161 andreas 1325: cp = buffer_ptr(&active_state->incoming_packet);
1.89 markus 1326: padlen = cp[4];
1.25 markus 1327: DBG(debug("input: padlen %d", padlen));
1328: if (padlen < 4)
1329: packet_disconnect("Corrupted padlen %d on input.", padlen);
1330:
1331: /* skip packet size + padlen, discard padding */
1.161 andreas 1332: buffer_consume(&active_state->incoming_packet, 4 + 1);
1333: buffer_consume_end(&active_state->incoming_packet, padlen);
1.25 markus 1334:
1.161 andreas 1335: DBG(debug("input: len before de-compress %d",
1336: buffer_len(&active_state->incoming_packet)));
1.25 markus 1337: if (comp && comp->enabled) {
1.161 andreas 1338: buffer_clear(&active_state->compression_buffer);
1339: buffer_uncompress(&active_state->incoming_packet,
1340: &active_state->compression_buffer);
1341: buffer_clear(&active_state->incoming_packet);
1342: buffer_append(&active_state->incoming_packet,
1343: buffer_ptr(&active_state->compression_buffer),
1344: buffer_len(&active_state->compression_buffer));
1.97 deraadt 1345: DBG(debug("input: len after de-compress %d",
1.161 andreas 1346: buffer_len(&active_state->incoming_packet)));
1.25 markus 1347: }
1348: /*
1349: * get packet type, implies consume.
1350: * return length of payload (without type field)
1351: */
1.161 andreas 1352: type = buffer_get_char(&active_state->incoming_packet);
1.116 markus 1353: if (type < SSH2_MSG_MIN || type >= SSH2_MSG_LOCAL_MIN)
1354: packet_disconnect("Invalid ssh2 packet type: %d", type);
1.57 markus 1355: if (type == SSH2_MSG_NEWKEYS)
1356: set_newkeys(MODE_IN);
1.161 andreas 1357: else if (type == SSH2_MSG_USERAUTH_SUCCESS &&
1358: !active_state->server_side)
1.118 markus 1359: packet_enable_delayed_compress();
1.25 markus 1360: #ifdef PACKET_DEBUG
1.55 deraadt 1361: fprintf(stderr, "read/plain[%d]:\r\n", type);
1.161 andreas 1362: buffer_dump(&active_state->incoming_packet);
1.25 markus 1363: #endif
1.62 markus 1364: /* reset for next packet */
1.161 andreas 1365: active_state->packlen = 0;
1.62 markus 1366: return type;
1.25 markus 1367: }
1368:
1369: int
1.82 markus 1370: packet_read_poll_seqnr(u_int32_t *seqnr_p)
1.25 markus 1371: {
1.96 deraadt 1372: u_int reason, seqnr;
1.62 markus 1373: u_char type;
1.25 markus 1374: char *msg;
1.62 markus 1375:
1.25 markus 1376: for (;;) {
1.62 markus 1377: if (compat20) {
1.82 markus 1378: type = packet_read_poll2(seqnr_p);
1.153 djm 1379: if (type) {
1.161 andreas 1380: active_state->keep_alive_timeouts = 0;
1.25 markus 1381: DBG(debug("received packet type %d", type));
1.153 djm 1382: }
1.74 deraadt 1383: switch (type) {
1.150 dtucker 1384: case SSH2_MSG_IGNORE:
1.151 dtucker 1385: debug3("Received SSH2_MSG_IGNORE");
1.150 dtucker 1386: break;
1.25 markus 1387: case SSH2_MSG_DEBUG:
1388: packet_get_char();
1389: msg = packet_get_string(NULL);
1390: debug("Remote: %.900s", msg);
1391: xfree(msg);
1392: msg = packet_get_string(NULL);
1393: xfree(msg);
1394: break;
1395: case SSH2_MSG_DISCONNECT:
1396: reason = packet_get_int();
1397: msg = packet_get_string(NULL);
1.106 itojun 1398: logit("Received disconnect from %s: %u: %.400s",
1.96 deraadt 1399: get_remote_ipaddr(), reason, msg);
1.25 markus 1400: xfree(msg);
1.112 markus 1401: cleanup_exit(255);
1.84 markus 1402: break;
1403: case SSH2_MSG_UNIMPLEMENTED:
1404: seqnr = packet_get_int();
1.96 deraadt 1405: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1406: seqnr);
1.150 dtucker 1407: break;
1.25 markus 1408: default:
1409: return type;
1.48 stevesk 1410: }
1.25 markus 1411: } else {
1.82 markus 1412: type = packet_read_poll1();
1.74 deraadt 1413: switch (type) {
1.25 markus 1414: case SSH_MSG_IGNORE:
1415: break;
1416: case SSH_MSG_DEBUG:
1417: msg = packet_get_string(NULL);
1418: debug("Remote: %.900s", msg);
1419: xfree(msg);
1420: break;
1421: case SSH_MSG_DISCONNECT:
1422: msg = packet_get_string(NULL);
1.106 itojun 1423: logit("Received disconnect from %s: %.400s",
1.96 deraadt 1424: get_remote_ipaddr(), msg);
1.112 markus 1425: cleanup_exit(255);
1.25 markus 1426: break;
1427: default:
1.62 markus 1428: if (type)
1.25 markus 1429: DBG(debug("received packet type %d", type));
1430: return type;
1.48 stevesk 1431: }
1.25 markus 1432: }
1433: }
1.77 djm 1434: }
1435:
1436: int
1.82 markus 1437: packet_read_poll(void)
1.77 djm 1438: {
1.82 markus 1439: return packet_read_poll_seqnr(NULL);
1.25 markus 1440: }
1441:
1.16 markus 1442: /*
1443: * Buffers the given amount of input characters. This is intended to be used
1444: * together with packet_read_poll.
1445: */
1.1 deraadt 1446:
1.2 provos 1447: void
1.40 markus 1448: packet_process_incoming(const char *buf, u_int len)
1.1 deraadt 1449: {
1.161 andreas 1450: if (active_state->packet_discard) {
1451: active_state->keep_alive_timeouts = 0; /* ?? */
1452: if (len >= active_state->packet_discard)
1.159 markus 1453: packet_stop_discard();
1.161 andreas 1454: active_state->packet_discard -= len;
1.159 markus 1455: return;
1456: }
1.161 andreas 1457: buffer_append(&active_state->input, buf, len);
1.1 deraadt 1458: }
1459:
1460: /* Returns a character from the packet. */
1461:
1.40 markus 1462: u_int
1.73 itojun 1463: packet_get_char(void)
1.1 deraadt 1464: {
1.14 markus 1465: char ch;
1.97 deraadt 1466:
1.161 andreas 1467: buffer_get(&active_state->incoming_packet, &ch, 1);
1.40 markus 1468: return (u_char) ch;
1.1 deraadt 1469: }
1470:
1471: /* Returns an integer from the packet data. */
1472:
1.40 markus 1473: u_int
1.73 itojun 1474: packet_get_int(void)
1.1 deraadt 1475: {
1.161 andreas 1476: return buffer_get_int(&active_state->incoming_packet);
1.162 andreas 1477: }
1478:
1479: /* Returns an 64 bit integer from the packet data. */
1480:
1481: u_int64_t
1482: packet_get_int64(void)
1483: {
1484: return buffer_get_int64(&active_state->incoming_packet);
1.1 deraadt 1485: }
1486:
1.16 markus 1487: /*
1488: * Returns an arbitrary precision integer from the packet data. The integer
1489: * must have been initialized before this call.
1490: */
1.1 deraadt 1491:
1.2 provos 1492: void
1.80 markus 1493: packet_get_bignum(BIGNUM * value)
1.1 deraadt 1494: {
1.161 andreas 1495: buffer_get_bignum(&active_state->incoming_packet, value);
1.24 markus 1496: }
1497:
1498: void
1.80 markus 1499: packet_get_bignum2(BIGNUM * value)
1.24 markus 1500: {
1.161 andreas 1501: buffer_get_bignum2(&active_state->incoming_packet, value);
1.24 markus 1502: }
1503:
1.76 stevesk 1504: void *
1.117 djm 1505: packet_get_raw(u_int *length_ptr)
1.24 markus 1506: {
1.161 andreas 1507: u_int bytes = buffer_len(&active_state->incoming_packet);
1.97 deraadt 1508:
1.24 markus 1509: if (length_ptr != NULL)
1510: *length_ptr = bytes;
1.161 andreas 1511: return buffer_ptr(&active_state->incoming_packet);
1.28 markus 1512: }
1513:
1514: int
1515: packet_remaining(void)
1516: {
1.161 andreas 1517: return buffer_len(&active_state->incoming_packet);
1.1 deraadt 1518: }
1519:
1.16 markus 1520: /*
1521: * Returns a string from the packet data. The string is allocated using
1522: * xmalloc; it is the responsibility of the calling program to free it when
1523: * no longer needed. The length_ptr argument may be NULL, or point to an
1524: * integer into which the length of the string is stored.
1525: */
1.1 deraadt 1526:
1.76 stevesk 1527: void *
1.40 markus 1528: packet_get_string(u_int *length_ptr)
1.1 deraadt 1529: {
1.161 andreas 1530: return buffer_get_string(&active_state->incoming_packet, length_ptr);
1.152 markus 1531: }
1532:
1533: void *
1534: packet_get_string_ptr(u_int *length_ptr)
1535: {
1.161 andreas 1536: return buffer_get_string_ptr(&active_state->incoming_packet, length_ptr);
1.1 deraadt 1537: }
1538:
1.16 markus 1539: /*
1540: * Sends a diagnostic message from the server to the client. This message
1541: * can be sent at any time (but not while constructing another message). The
1542: * message is printed immediately, but only if the client is being executed
1543: * in verbose mode. These messages are primarily intended to ease debugging
1544: * authentication problems. The length of the formatted message must not
1545: * exceed 1024 bytes. This will automatically call packet_write_wait.
1546: */
1.1 deraadt 1547:
1.2 provos 1548: void
1.14 markus 1549: packet_send_debug(const char *fmt,...)
1.1 deraadt 1550: {
1.14 markus 1551: char buf[1024];
1552: va_list args;
1.39 markus 1553:
1554: if (compat20 && (datafellows & SSH_BUG_DEBUG))
1555: return;
1.14 markus 1556:
1557: va_start(args, fmt);
1558: vsnprintf(buf, sizeof(buf), fmt, args);
1559: va_end(args);
1560:
1.30 markus 1561: if (compat20) {
1562: packet_start(SSH2_MSG_DEBUG);
1563: packet_put_char(0); /* bool: always display */
1564: packet_put_cstring(buf);
1565: packet_put_cstring("");
1566: } else {
1567: packet_start(SSH_MSG_DEBUG);
1568: packet_put_cstring(buf);
1569: }
1.14 markus 1570: packet_send();
1571: packet_write_wait();
1.1 deraadt 1572: }
1573:
1.16 markus 1574: /*
1575: * Logs the error plus constructs and sends a disconnect packet, closes the
1576: * connection, and exits. This function never returns. The error message
1577: * should not contain a newline. The length of the formatted message must
1578: * not exceed 1024 bytes.
1579: */
1.1 deraadt 1580:
1.2 provos 1581: void
1.14 markus 1582: packet_disconnect(const char *fmt,...)
1.1 deraadt 1583: {
1.14 markus 1584: char buf[1024];
1585: va_list args;
1586: static int disconnecting = 0;
1.97 deraadt 1587:
1.14 markus 1588: if (disconnecting) /* Guard against recursive invocations. */
1589: fatal("packet_disconnect called recursively.");
1590: disconnecting = 1;
1591:
1.16 markus 1592: /*
1593: * Format the message. Note that the caller must make sure the
1594: * message is of limited size.
1595: */
1.14 markus 1596: va_start(args, fmt);
1597: vsnprintf(buf, sizeof(buf), fmt, args);
1598: va_end(args);
1599:
1.99 markus 1600: /* Display the error locally */
1.106 itojun 1601: logit("Disconnecting: %.100s", buf);
1.99 markus 1602:
1.14 markus 1603: /* Send the disconnect message to the other side, and wait for it to get sent. */
1.25 markus 1604: if (compat20) {
1605: packet_start(SSH2_MSG_DISCONNECT);
1606: packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR);
1607: packet_put_cstring(buf);
1608: packet_put_cstring("");
1609: } else {
1610: packet_start(SSH_MSG_DISCONNECT);
1.65 markus 1611: packet_put_cstring(buf);
1.25 markus 1612: }
1.14 markus 1613: packet_send();
1614: packet_write_wait();
1615:
1616: /* Stop listening for connections. */
1.67 markus 1617: channel_close_all();
1.14 markus 1618:
1619: /* Close the connection. */
1620: packet_close();
1.112 markus 1621: cleanup_exit(255);
1.1 deraadt 1622: }
1623:
1.16 markus 1624: /* Checks if there is any buffered output, and tries to write some of the output. */
1.1 deraadt 1625:
1.2 provos 1626: void
1.73 itojun 1627: packet_write_poll(void)
1.1 deraadt 1628: {
1.161 andreas 1629: int len = buffer_len(&active_state->output);
1.163 andreas 1630: int cont;
1.97 deraadt 1631:
1.14 markus 1632: if (len > 0) {
1.163 andreas 1633: cont = 0;
1634: len = roaming_write(active_state->connection_out,
1635: buffer_ptr(&active_state->output), len, &cont);
1.156 djm 1636: if (len == -1) {
1637: if (errno == EINTR || errno == EAGAIN)
1.14 markus 1638: return;
1.156 djm 1639: fatal("Write failed: %.100s", strerror(errno));
1.14 markus 1640: }
1.163 andreas 1641: if (len == 0 && !cont)
1.156 djm 1642: fatal("Write connection closed");
1.161 andreas 1643: buffer_consume(&active_state->output, len);
1.14 markus 1644: }
1.1 deraadt 1645: }
1646:
1.16 markus 1647: /*
1648: * Calls packet_write_poll repeatedly until all pending output data has been
1649: * written.
1650: */
1.1 deraadt 1651:
1.2 provos 1652: void
1.73 itojun 1653: packet_write_wait(void)
1.1 deraadt 1654: {
1.56 millert 1655: fd_set *setp;
1.154 dtucker 1656: int ret, ms_remain;
1657: struct timeval start, timeout, *timeoutp = NULL;
1.56 millert 1658:
1.161 andreas 1659: setp = (fd_set *)xcalloc(howmany(active_state->connection_out + 1,
1660: NFDBITS), sizeof(fd_mask));
1.14 markus 1661: packet_write_poll();
1662: while (packet_have_data_to_write()) {
1.161 andreas 1663: memset(setp, 0, howmany(active_state->connection_out + 1,
1664: NFDBITS) * sizeof(fd_mask));
1665: FD_SET(active_state->connection_out, setp);
1.154 dtucker 1666:
1.161 andreas 1667: if (active_state->packet_timeout_ms > 0) {
1668: ms_remain = active_state->packet_timeout_ms;
1.154 dtucker 1669: timeoutp = &timeout;
1670: }
1671: for (;;) {
1.161 andreas 1672: if (active_state->packet_timeout_ms != -1) {
1.154 dtucker 1673: ms_to_timeval(&timeout, ms_remain);
1674: gettimeofday(&start, NULL);
1675: }
1.161 andreas 1676: if ((ret = select(active_state->connection_out + 1,
1677: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1678: break;
1.161 andreas 1679: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1680: break;
1.161 andreas 1681: if (active_state->packet_timeout_ms == -1)
1.154 dtucker 1682: continue;
1683: ms_subtract_diff(&start, &ms_remain);
1684: if (ms_remain <= 0) {
1685: ret = 0;
1686: break;
1687: }
1688: }
1689: if (ret == 0) {
1690: logit("Connection to %.200s timed out while "
1691: "waiting to write", get_remote_ipaddr());
1692: cleanup_exit(255);
1693: }
1.14 markus 1694: packet_write_poll();
1695: }
1.56 millert 1696: xfree(setp);
1.1 deraadt 1697: }
1698:
1699: /* Returns true if there is buffered data to write to the connection. */
1700:
1.2 provos 1701: int
1.73 itojun 1702: packet_have_data_to_write(void)
1.1 deraadt 1703: {
1.161 andreas 1704: return buffer_len(&active_state->output) != 0;
1.1 deraadt 1705: }
1706:
1707: /* Returns true if there is not too much data to write to the connection. */
1708:
1.2 provos 1709: int
1.73 itojun 1710: packet_not_very_much_data_to_write(void)
1.1 deraadt 1711: {
1.161 andreas 1712: if (active_state->interactive_mode)
1713: return buffer_len(&active_state->output) < 16384;
1.14 markus 1714: else
1.161 andreas 1715: return buffer_len(&active_state->output) < 128 * 1024;
1.1 deraadt 1716: }
1717:
1.102 markus 1718: static void
1.101 markus 1719: packet_set_tos(int interactive)
1720: {
1721: int tos = interactive ? IPTOS_LOWDELAY : IPTOS_THROUGHPUT;
1722:
1723: if (!packet_connection_is_on_socket() ||
1724: !packet_connection_is_ipv4())
1725: return;
1.161 andreas 1726: if (setsockopt(active_state->connection_in, IPPROTO_IP, IP_TOS, &tos,
1.101 markus 1727: sizeof(tos)) < 0)
1728: error("setsockopt IP_TOS %d: %.100s:",
1729: tos, strerror(errno));
1730: }
1731:
1.1 deraadt 1732: /* Informs that the current session is interactive. Sets IP flags for that. */
1733:
1.2 provos 1734: void
1.43 markus 1735: packet_set_interactive(int interactive)
1.1 deraadt 1736: {
1.165 andreas 1737: if (active_state->set_interactive_called)
1.43 markus 1738: return;
1.165 andreas 1739: active_state->set_interactive_called = 1;
1.1 deraadt 1740:
1.14 markus 1741: /* Record that we are in interactive mode. */
1.161 andreas 1742: active_state->interactive_mode = interactive;
1.1 deraadt 1743:
1.19 markus 1744: /* Only set socket options if using a socket. */
1745: if (!packet_connection_is_on_socket())
1.14 markus 1746: return;
1.161 andreas 1747: set_nodelay(active_state->connection_in);
1.101 markus 1748: packet_set_tos(interactive);
1.1 deraadt 1749: }
1750:
1751: /* Returns true if the current connection is interactive. */
1752:
1.2 provos 1753: int
1.73 itojun 1754: packet_is_interactive(void)
1.1 deraadt 1755: {
1.161 andreas 1756: return active_state->interactive_mode;
1.12 markus 1757: }
1758:
1.113 deraadt 1759: int
1.108 markus 1760: packet_set_maxsize(u_int s)
1.12 markus 1761: {
1.165 andreas 1762: if (active_state->set_maxsize_called) {
1.106 itojun 1763: logit("packet_set_maxsize: called twice: old %d new %d",
1.161 andreas 1764: active_state->max_packet_size, s);
1.14 markus 1765: return -1;
1766: }
1767: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 1768: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 1769: return -1;
1770: }
1.165 andreas 1771: active_state->set_maxsize_called = 1;
1.66 markus 1772: debug("packet_set_maxsize: setting to %d", s);
1.161 andreas 1773: active_state->max_packet_size = s;
1.14 markus 1774: return s;
1.53 markus 1775: }
1776:
1.161 andreas 1777: int
1778: packet_inc_alive_timeouts(void)
1779: {
1780: return ++active_state->keep_alive_timeouts;
1781: }
1782:
1783: void
1784: packet_set_alive_timeouts(int ka)
1785: {
1786: active_state->keep_alive_timeouts = ka;
1787: }
1788:
1789: u_int
1790: packet_get_maxsize(void)
1791: {
1792: return active_state->max_packet_size;
1793: }
1794:
1.71 markus 1795: /* roundup current message to pad bytes */
1796: void
1797: packet_add_padding(u_char pad)
1798: {
1.161 andreas 1799: active_state->extra_pad = pad;
1.71 markus 1800: }
1801:
1.53 markus 1802: /*
1803: * 9.2. Ignored Data Message
1.61 markus 1804: *
1.53 markus 1805: * byte SSH_MSG_IGNORE
1806: * string data
1.61 markus 1807: *
1.53 markus 1808: * All implementations MUST understand (and ignore) this message at any
1809: * time (after receiving the protocol version). No implementation is
1810: * required to send them. This message can be used as an additional
1811: * protection measure against advanced traffic analysis techniques.
1812: */
1.54 markus 1813: void
1814: packet_send_ignore(int nbytes)
1815: {
1.115 avsm 1816: u_int32_t rnd = 0;
1.54 markus 1817: int i;
1818:
1819: packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE);
1.53 markus 1820: packet_put_int(nbytes);
1.75 deraadt 1821: for (i = 0; i < nbytes; i++) {
1.53 markus 1822: if (i % 4 == 0)
1.115 avsm 1823: rnd = arc4random();
1.129 deraadt 1824: packet_put_char((u_char)rnd & 0xff);
1.115 avsm 1825: rnd >>= 8;
1.53 markus 1826: }
1.105 markus 1827: }
1828:
1.113 deraadt 1829: #define MAX_PACKETS (1U<<31)
1.105 markus 1830: int
1831: packet_need_rekeying(void)
1832: {
1833: if (datafellows & SSH_BUG_NOREKEY)
1834: return 0;
1835: return
1.161 andreas 1836: (active_state->p_send.packets > MAX_PACKETS) ||
1837: (active_state->p_read.packets > MAX_PACKETS) ||
1838: (active_state->max_blocks_out &&
1839: (active_state->p_send.blocks > active_state->max_blocks_out)) ||
1840: (active_state->max_blocks_in &&
1841: (active_state->p_read.blocks > active_state->max_blocks_in));
1.105 markus 1842: }
1843:
1844: void
1845: packet_set_rekey_limit(u_int32_t bytes)
1846: {
1.161 andreas 1847: active_state->rekey_limit = bytes;
1.118 markus 1848: }
1849:
1850: void
1851: packet_set_server(void)
1852: {
1.161 andreas 1853: active_state->server_side = 1;
1.118 markus 1854: }
1855:
1856: void
1857: packet_set_authenticated(void)
1858: {
1.161 andreas 1859: active_state->after_authentication = 1;
1860: }
1861:
1862: void *
1863: packet_get_input(void)
1864: {
1865: return (void *)&active_state->input;
1866: }
1867:
1868: void *
1869: packet_get_output(void)
1870: {
1871: return (void *)&active_state->output;
1872: }
1873:
1874: void *
1875: packet_get_newkeys(int mode)
1876: {
1877: return (void *)active_state->newkeys[mode];
1.166 ! andreas 1878: }
! 1879:
! 1880: /*
! 1881: * Save the state for the real connection, and use a separate state when
! 1882: * resuming a suspended connection.
! 1883: */
! 1884: void
! 1885: packet_backup_state(void)
! 1886: {
! 1887: struct session_state *tmp;
! 1888:
! 1889: close(active_state->connection_in);
! 1890: active_state->connection_in = -1;
! 1891: close(active_state->connection_out);
! 1892: active_state->connection_out = -1;
! 1893: if (backup_state)
! 1894: tmp = backup_state;
! 1895: else
! 1896: tmp = alloc_session_state();
! 1897: backup_state = active_state;
! 1898: active_state = tmp;
! 1899: }
! 1900:
! 1901: /*
! 1902: * Swap in the old state when resuming a connecion.
! 1903: */
! 1904: void
! 1905: packet_restore_state(void)
! 1906: {
! 1907: struct session_state *tmp;
! 1908: void *buf;
! 1909: u_int len;
! 1910:
! 1911: tmp = backup_state;
! 1912: backup_state = active_state;
! 1913: active_state = tmp;
! 1914: active_state->connection_in = backup_state->connection_in;
! 1915: backup_state->connection_in = -1;
! 1916: active_state->connection_out = backup_state->connection_out;
! 1917: backup_state->connection_out = -1;
! 1918: len = buffer_len(&backup_state->input);
! 1919: if (len > 0) {
! 1920: buf = buffer_ptr(&backup_state->input);
! 1921: buffer_append(&active_state->input, buf, len);
! 1922: buffer_clear(&backup_state->input);
! 1923: add_recv_bytes(len);
! 1924: }
1.1 deraadt 1925: }
![[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