Annotation of src/usr.bin/ssh/packet.c, Revision 1.183
1.183 ! djm 1: /* $OpenBSD: packet.c,v 1.182 2013/04/11 02:27:50 djm 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: {
1.171 djm 198: struct session_state *s = xcalloc(1, sizeof(*s));
1.161 andreas 199:
1.171 djm 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;
1.161 andreas 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: {
1.183 ! djm 214: const 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: {
1.174 djm 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: {
1.178 markus 274: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm))
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
1.171 djm 390: packet_get_state(int mode, u_int32_t *seqnr, u_int64_t *blocks,
391: u_int32_t *packets, 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:
1.173 djm 421: static int
422: packet_connection_af(void)
1.19 markus 423: {
424: struct sockaddr_storage to;
1.21 deraadt 425: socklen_t tolen = sizeof(to);
1.19 markus 426:
427: memset(&to, 0, sizeof(to));
1.161 andreas 428: if (getsockname(active_state->connection_out, (struct sockaddr *)&to,
429: &tolen) < 0)
1.19 markus 430: return 0;
1.173 djm 431: return to.ss_family;
1.19 markus 432: }
433:
1.1 deraadt 434: /* Sets the connection into non-blocking mode. */
435:
1.2 provos 436: void
1.73 itojun 437: packet_set_nonblocking(void)
1.1 deraadt 438: {
1.14 markus 439: /* Set the socket into non-blocking mode. */
1.161 andreas 440: set_nonblock(active_state->connection_in);
1.14 markus 441:
1.161 andreas 442: if (active_state->connection_out != active_state->connection_in)
443: set_nonblock(active_state->connection_out);
1.1 deraadt 444: }
445:
446: /* Returns the socket used for reading. */
447:
1.2 provos 448: int
1.73 itojun 449: packet_get_connection_in(void)
1.1 deraadt 450: {
1.161 andreas 451: return active_state->connection_in;
1.1 deraadt 452: }
453:
454: /* Returns the descriptor used for writing. */
455:
1.2 provos 456: int
1.73 itojun 457: packet_get_connection_out(void)
1.1 deraadt 458: {
1.161 andreas 459: return active_state->connection_out;
1.1 deraadt 460: }
461:
462: /* Closes the connection and clears and frees internal data structures. */
463:
1.2 provos 464: void
1.73 itojun 465: packet_close(void)
1.1 deraadt 466: {
1.161 andreas 467: if (!active_state->initialized)
1.14 markus 468: return;
1.161 andreas 469: active_state->initialized = 0;
470: if (active_state->connection_in == active_state->connection_out) {
471: shutdown(active_state->connection_out, SHUT_RDWR);
472: close(active_state->connection_out);
1.14 markus 473: } else {
1.161 andreas 474: close(active_state->connection_in);
475: close(active_state->connection_out);
1.14 markus 476: }
1.161 andreas 477: buffer_free(&active_state->input);
478: buffer_free(&active_state->output);
479: buffer_free(&active_state->outgoing_packet);
480: buffer_free(&active_state->incoming_packet);
481: if (active_state->compression_buffer_ready) {
482: buffer_free(&active_state->compression_buffer);
1.14 markus 483: buffer_compress_uninit();
484: }
1.161 andreas 485: cipher_cleanup(&active_state->send_context);
486: cipher_cleanup(&active_state->receive_context);
1.1 deraadt 487: }
488:
489: /* Sets remote side protocol flags. */
490:
1.2 provos 491: void
1.40 markus 492: packet_set_protocol_flags(u_int protocol_flags)
1.1 deraadt 493: {
1.161 andreas 494: active_state->remote_protocol_flags = protocol_flags;
1.1 deraadt 495: }
496:
497: /* Returns the remote protocol flags set earlier by the above function. */
498:
1.40 markus 499: u_int
1.73 itojun 500: packet_get_protocol_flags(void)
1.1 deraadt 501: {
1.161 andreas 502: return active_state->remote_protocol_flags;
1.1 deraadt 503: }
504:
1.16 markus 505: /*
506: * Starts packet compression from the next packet on in both directions.
507: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
508: */
1.1 deraadt 509:
1.68 itojun 510: static void
511: packet_init_compression(void)
1.60 markus 512: {
1.161 andreas 513: if (active_state->compression_buffer_ready == 1)
1.60 markus 514: return;
1.161 andreas 515: active_state->compression_buffer_ready = 1;
516: buffer_init(&active_state->compression_buffer);
1.60 markus 517: }
518:
1.2 provos 519: void
520: packet_start_compression(int level)
1.1 deraadt 521: {
1.161 andreas 522: if (active_state->packet_compression && !compat20)
1.14 markus 523: fatal("Compression already enabled.");
1.161 andreas 524: active_state->packet_compression = 1;
1.60 markus 525: packet_init_compression();
526: buffer_compress_init_send(level);
527: buffer_compress_init_recv();
1.1 deraadt 528: }
529:
1.16 markus 530: /*
531: * Causes any further packets to be encrypted using the given key. The same
532: * key is used for both sending and reception. However, both directions are
533: * encrypted independently of each other.
534: */
1.95 markus 535:
1.2 provos 536: void
1.171 djm 537: packet_set_encryption_key(const u_char *key, u_int keylen, int number)
1.1 deraadt 538: {
1.183 ! djm 539: const Cipher *cipher = cipher_by_number(number);
1.97 deraadt 540:
1.37 markus 541: if (cipher == NULL)
542: fatal("packet_set_encryption_key: unknown cipher number %d", number);
1.25 markus 543: if (keylen < 20)
1.37 markus 544: fatal("packet_set_encryption_key: keylen too small: %d", keylen);
1.95 markus 545: if (keylen > SSH_SESSION_KEY_LENGTH)
546: fatal("packet_set_encryption_key: keylen too big: %d", keylen);
1.161 andreas 547: memcpy(active_state->ssh1_key, key, keylen);
548: active_state->ssh1_keylen = keylen;
549: cipher_init(&active_state->send_context, cipher, key, keylen, NULL,
550: 0, CIPHER_ENCRYPT);
551: cipher_init(&active_state->receive_context, cipher, key, keylen, NULL,
552: 0, CIPHER_DECRYPT);
1.95 markus 553: }
554:
555: u_int
556: packet_get_encryption_key(u_char *key)
557: {
558: if (key == NULL)
1.161 andreas 559: return (active_state->ssh1_keylen);
560: memcpy(key, active_state->ssh1_key, active_state->ssh1_keylen);
561: return (active_state->ssh1_keylen);
1.1 deraadt 562: }
563:
1.62 markus 564: /* Start constructing a packet to send. */
1.2 provos 565: void
1.62 markus 566: packet_start(u_char type)
1.1 deraadt 567: {
1.62 markus 568: u_char buf[9];
569: int len;
1.1 deraadt 570:
1.62 markus 571: DBG(debug("packet_start[%d]", type));
572: len = compat20 ? 6 : 9;
573: memset(buf, 0, len - 1);
574: buf[len - 1] = type;
1.161 andreas 575: buffer_clear(&active_state->outgoing_packet);
576: buffer_append(&active_state->outgoing_packet, buf, len);
1.25 markus 577: }
578:
1.62 markus 579: /* Append payload. */
1.2 provos 580: void
581: packet_put_char(int value)
1.1 deraadt 582: {
1.14 markus 583: char ch = value;
1.97 deraadt 584:
1.161 andreas 585: buffer_append(&active_state->outgoing_packet, &ch, 1);
1.1 deraadt 586: }
1.125 deraadt 587:
1.2 provos 588: void
1.40 markus 589: packet_put_int(u_int value)
1.1 deraadt 590: {
1.161 andreas 591: buffer_put_int(&active_state->outgoing_packet, value);
1.1 deraadt 592: }
1.125 deraadt 593:
1.2 provos 594: void
1.162 andreas 595: packet_put_int64(u_int64_t value)
596: {
597: buffer_put_int64(&active_state->outgoing_packet, value);
598: }
599:
600: void
1.76 stevesk 601: packet_put_string(const void *buf, u_int len)
1.1 deraadt 602: {
1.161 andreas 603: buffer_put_string(&active_state->outgoing_packet, buf, len);
1.1 deraadt 604: }
1.125 deraadt 605:
1.24 markus 606: void
607: packet_put_cstring(const char *str)
608: {
1.161 andreas 609: buffer_put_cstring(&active_state->outgoing_packet, str);
1.24 markus 610: }
1.125 deraadt 611:
1.24 markus 612: void
1.76 stevesk 613: packet_put_raw(const void *buf, u_int len)
1.24 markus 614: {
1.161 andreas 615: buffer_append(&active_state->outgoing_packet, buf, len);
1.24 markus 616: }
1.125 deraadt 617:
1.2 provos 618: void
1.14 markus 619: packet_put_bignum(BIGNUM * value)
1.1 deraadt 620: {
1.161 andreas 621: buffer_put_bignum(&active_state->outgoing_packet, value);
1.1 deraadt 622: }
1.125 deraadt 623:
1.24 markus 624: void
625: packet_put_bignum2(BIGNUM * value)
626: {
1.161 andreas 627: buffer_put_bignum2(&active_state->outgoing_packet, value);
1.24 markus 628: }
1.1 deraadt 629:
1.170 djm 630: void
631: packet_put_ecpoint(const EC_GROUP *curve, const EC_POINT *point)
632: {
633: buffer_put_ecpoint(&active_state->outgoing_packet, curve, point);
634: }
635:
1.16 markus 636: /*
637: * Finalizes and sends the packet. If the encryption key has been set,
638: * encrypts the packet before sending.
639: */
1.14 markus 640:
1.68 itojun 641: static void
1.49 itojun 642: packet_send1(void)
1.1 deraadt 643: {
1.89 markus 644: u_char buf[8], *cp;
1.14 markus 645: int i, padding, len;
1.40 markus 646: u_int checksum;
1.115 avsm 647: u_int32_t rnd = 0;
1.14 markus 648:
1.16 markus 649: /*
650: * If using packet compression, compress the payload of the outgoing
651: * packet.
652: */
1.161 andreas 653: if (active_state->packet_compression) {
654: buffer_clear(&active_state->compression_buffer);
1.14 markus 655: /* Skip padding. */
1.161 andreas 656: buffer_consume(&active_state->outgoing_packet, 8);
1.14 markus 657: /* padding */
1.161 andreas 658: buffer_append(&active_state->compression_buffer,
659: "\0\0\0\0\0\0\0\0", 8);
660: buffer_compress(&active_state->outgoing_packet,
661: &active_state->compression_buffer);
662: buffer_clear(&active_state->outgoing_packet);
663: buffer_append(&active_state->outgoing_packet,
664: buffer_ptr(&active_state->compression_buffer),
665: buffer_len(&active_state->compression_buffer));
1.14 markus 666: }
667: /* Compute packet length without padding (add checksum, remove padding). */
1.161 andreas 668: len = buffer_len(&active_state->outgoing_packet) + 4 - 8;
1.14 markus 669:
1.32 markus 670: /* Insert padding. Initialized to zero in packet_start1() */
1.14 markus 671: padding = 8 - len % 8;
1.161 andreas 672: if (!active_state->send_context.plaintext) {
673: cp = buffer_ptr(&active_state->outgoing_packet);
1.14 markus 674: for (i = 0; i < padding; i++) {
675: if (i % 4 == 0)
1.115 avsm 676: rnd = arc4random();
677: cp[7 - i] = rnd & 0xff;
678: rnd >>= 8;
1.14 markus 679: }
680: }
1.161 andreas 681: buffer_consume(&active_state->outgoing_packet, 8 - padding);
1.14 markus 682:
683: /* Add check bytes. */
1.161 andreas 684: checksum = ssh_crc32(buffer_ptr(&active_state->outgoing_packet),
685: buffer_len(&active_state->outgoing_packet));
1.131 djm 686: put_u32(buf, checksum);
1.161 andreas 687: buffer_append(&active_state->outgoing_packet, buf, 4);
1.1 deraadt 688:
689: #ifdef PACKET_DEBUG
1.14 markus 690: fprintf(stderr, "packet_send plain: ");
1.161 andreas 691: buffer_dump(&active_state->outgoing_packet);
1.1 deraadt 692: #endif
693:
1.14 markus 694: /* Append to output. */
1.131 djm 695: put_u32(buf, len);
1.161 andreas 696: buffer_append(&active_state->output, buf, 4);
697: cp = buffer_append_space(&active_state->output,
698: buffer_len(&active_state->outgoing_packet));
699: cipher_crypt(&active_state->send_context, cp,
700: buffer_ptr(&active_state->outgoing_packet),
1.180 markus 701: buffer_len(&active_state->outgoing_packet), 0, 0);
1.14 markus 702:
1.1 deraadt 703: #ifdef PACKET_DEBUG
1.14 markus 704: fprintf(stderr, "encrypted: ");
1.161 andreas 705: buffer_dump(&active_state->output);
1.1 deraadt 706: #endif
1.161 andreas 707: active_state->p_send.packets++;
708: active_state->p_send.bytes += len +
709: buffer_len(&active_state->outgoing_packet);
710: buffer_clear(&active_state->outgoing_packet);
1.1 deraadt 711:
1.16 markus 712: /*
1.120 djm 713: * Note that the packet is now only buffered in output. It won't be
1.16 markus 714: * actually sent until packet_write_wait or packet_write_poll is
715: * called.
716: */
1.1 deraadt 717: }
718:
1.91 markus 719: void
1.57 markus 720: set_newkeys(int mode)
721: {
722: Enc *enc;
723: Mac *mac;
724: Comp *comp;
725: CipherContext *cc;
1.105 markus 726: u_int64_t *max_blocks;
1.115 avsm 727: int crypt_type;
1.57 markus 728:
1.100 markus 729: debug2("set_newkeys: mode %d", mode);
1.57 markus 730:
1.88 markus 731: if (mode == MODE_OUT) {
1.161 andreas 732: cc = &active_state->send_context;
1.115 avsm 733: crypt_type = CIPHER_ENCRYPT;
1.161 andreas 734: active_state->p_send.packets = active_state->p_send.blocks = 0;
735: max_blocks = &active_state->max_blocks_out;
1.88 markus 736: } else {
1.161 andreas 737: cc = &active_state->receive_context;
1.115 avsm 738: crypt_type = CIPHER_DECRYPT;
1.161 andreas 739: active_state->p_read.packets = active_state->p_read.blocks = 0;
740: max_blocks = &active_state->max_blocks_in;
1.88 markus 741: }
1.161 andreas 742: if (active_state->newkeys[mode] != NULL) {
1.100 markus 743: debug("set_newkeys: rekeying");
1.88 markus 744: cipher_cleanup(cc);
1.161 andreas 745: enc = &active_state->newkeys[mode]->enc;
746: mac = &active_state->newkeys[mode]->mac;
747: comp = &active_state->newkeys[mode]->comp;
1.148 pvalchev 748: mac_clear(mac);
1.180 markus 749: memset(enc->iv, 0, enc->iv_len);
1.177 markus 750: memset(enc->key, 0, enc->key_len);
751: memset(mac->key, 0, mac->key_len);
1.59 markus 752: xfree(enc->name);
753: xfree(enc->iv);
754: xfree(enc->key);
755: xfree(mac->name);
756: xfree(mac->key);
757: xfree(comp->name);
1.161 andreas 758: xfree(active_state->newkeys[mode]);
1.57 markus 759: }
1.161 andreas 760: active_state->newkeys[mode] = kex_get_newkeys(mode);
761: if (active_state->newkeys[mode] == NULL)
1.57 markus 762: fatal("newkeys: no keys for mode %d", mode);
1.161 andreas 763: enc = &active_state->newkeys[mode]->enc;
764: mac = &active_state->newkeys[mode]->mac;
765: comp = &active_state->newkeys[mode]->comp;
1.180 markus 766: if (cipher_authlen(enc->cipher) == 0 && mac_init(mac) == 0)
1.57 markus 767: mac->enabled = 1;
768: DBG(debug("cipher_init_context: %d", mode));
1.88 markus 769: cipher_init(cc, enc->cipher, enc->key, enc->key_len,
1.180 markus 770: enc->iv, enc->iv_len, crypt_type);
1.91 markus 771: /* Deleting the keys does not gain extra security */
772: /* memset(enc->iv, 0, enc->block_size);
1.147 djm 773: memset(enc->key, 0, enc->key_len);
774: memset(mac->key, 0, mac->key_len); */
1.118 markus 775: if ((comp->type == COMP_ZLIB ||
1.161 andreas 776: (comp->type == COMP_DELAYED &&
777: active_state->after_authentication)) && comp->enabled == 0) {
1.60 markus 778: packet_init_compression();
779: if (mode == MODE_OUT)
780: buffer_compress_init_send(6);
781: else
782: buffer_compress_init_recv();
1.57 markus 783: comp->enabled = 1;
784: }
1.109 markus 785: /*
786: * The 2^(blocksize*2) limit is too expensive for 3DES,
787: * blowfish, etc, so enforce a 1GB limit for small blocksizes.
788: */
789: if (enc->block_size >= 16)
790: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
791: else
792: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.161 andreas 793: if (active_state->rekey_limit)
794: *max_blocks = MIN(*max_blocks,
795: active_state->rekey_limit / enc->block_size);
1.57 markus 796: }
797:
1.16 markus 798: /*
1.118 markus 799: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 800: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 801: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
802: */
803: static void
804: packet_enable_delayed_compress(void)
805: {
806: Comp *comp = NULL;
807: int mode;
808:
809: /*
810: * Remember that we are past the authentication step, so rekeying
811: * with COMP_DELAYED will turn on compression immediately.
812: */
1.161 andreas 813: active_state->after_authentication = 1;
1.118 markus 814: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 815: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.161 andreas 816: if (active_state->newkeys[mode] == NULL)
1.145 markus 817: continue;
1.161 andreas 818: comp = &active_state->newkeys[mode]->comp;
1.118 markus 819: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.119 markus 820: packet_init_compression();
1.118 markus 821: if (mode == MODE_OUT)
822: buffer_compress_init_send(6);
823: else
824: buffer_compress_init_recv();
825: comp->enabled = 1;
826: }
827: }
828: }
829:
830: /*
1.25 markus 831: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
832: */
1.68 itojun 833: static void
1.105 markus 834: packet_send2_wrapped(void)
1.25 markus 835: {
1.89 markus 836: u_char type, *cp, *macbuf = NULL;
1.178 markus 837: u_char padlen, pad = 0;
1.180 markus 838: u_int i, len, authlen = 0, aadlen = 0;
1.115 avsm 839: u_int32_t rnd = 0;
1.25 markus 840: Enc *enc = NULL;
841: Mac *mac = NULL;
842: Comp *comp = NULL;
843: int block_size;
844:
1.161 andreas 845: if (active_state->newkeys[MODE_OUT] != NULL) {
846: enc = &active_state->newkeys[MODE_OUT]->enc;
847: mac = &active_state->newkeys[MODE_OUT]->mac;
848: comp = &active_state->newkeys[MODE_OUT]->comp;
1.180 markus 849: /* disable mac for authenticated encryption */
850: if ((authlen = cipher_authlen(enc->cipher)) != 0)
851: mac = NULL;
1.25 markus 852: }
1.88 markus 853: block_size = enc ? enc->block_size : 8;
1.180 markus 854: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 855:
1.161 andreas 856: cp = buffer_ptr(&active_state->outgoing_packet);
1.89 markus 857: type = cp[5];
1.25 markus 858:
859: #ifdef PACKET_DEBUG
860: fprintf(stderr, "plain: ");
1.161 andreas 861: buffer_dump(&active_state->outgoing_packet);
1.25 markus 862: #endif
863:
864: if (comp && comp->enabled) {
1.161 andreas 865: len = buffer_len(&active_state->outgoing_packet);
1.25 markus 866: /* skip header, compress only payload */
1.161 andreas 867: buffer_consume(&active_state->outgoing_packet, 5);
868: buffer_clear(&active_state->compression_buffer);
869: buffer_compress(&active_state->outgoing_packet,
870: &active_state->compression_buffer);
871: buffer_clear(&active_state->outgoing_packet);
872: buffer_append(&active_state->outgoing_packet, "\0\0\0\0\0", 5);
873: buffer_append(&active_state->outgoing_packet,
874: buffer_ptr(&active_state->compression_buffer),
875: buffer_len(&active_state->compression_buffer));
1.25 markus 876: DBG(debug("compression: raw %d compressed %d", len,
1.161 andreas 877: buffer_len(&active_state->outgoing_packet)));
1.25 markus 878: }
879:
880: /* sizeof (packet_len + pad_len + payload) */
1.161 andreas 881: len = buffer_len(&active_state->outgoing_packet);
1.25 markus 882:
883: /*
884: * calc size of padding, alloc space, get random data,
885: * minimum padding is 4 bytes
886: */
1.178 markus 887: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 888: padlen = block_size - (len % block_size);
889: if (padlen < 4)
890: padlen += block_size;
1.161 andreas 891: if (active_state->extra_pad) {
1.71 markus 892: /* will wrap if extra_pad+padlen > 255 */
1.161 andreas 893: active_state->extra_pad =
894: roundup(active_state->extra_pad, block_size);
895: pad = active_state->extra_pad -
896: ((len + padlen) % active_state->extra_pad);
1.93 markus 897: debug3("packet_send2: adding %d (len %d padlen %d extra_pad %d)",
1.161 andreas 898: pad, len, padlen, active_state->extra_pad);
1.71 markus 899: padlen += pad;
1.161 andreas 900: active_state->extra_pad = 0;
1.71 markus 901: }
1.161 andreas 902: cp = buffer_append_space(&active_state->outgoing_packet, padlen);
903: if (enc && !active_state->send_context.plaintext) {
1.32 markus 904: /* random padding */
1.25 markus 905: for (i = 0; i < padlen; i++) {
906: if (i % 4 == 0)
1.115 avsm 907: rnd = arc4random();
908: cp[i] = rnd & 0xff;
909: rnd >>= 8;
1.25 markus 910: }
1.32 markus 911: } else {
912: /* clear padding */
913: memset(cp, 0, padlen);
1.25 markus 914: }
1.178 markus 915: /* sizeof (packet_len + pad_len + payload + padding) */
916: len = buffer_len(&active_state->outgoing_packet);
917: cp = buffer_ptr(&active_state->outgoing_packet);
1.25 markus 918: /* packet_length includes payload, padding and padding length field */
1.178 markus 919: put_u32(cp, len - 4);
1.89 markus 920: cp[4] = padlen;
1.178 markus 921: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
922: len, padlen, aadlen));
1.25 markus 923:
924: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 925: if (mac && mac->enabled && !mac->etm) {
1.161 andreas 926: macbuf = mac_compute(mac, active_state->p_send.seqnr,
1.178 markus 927: buffer_ptr(&active_state->outgoing_packet), len);
1.161 andreas 928: DBG(debug("done calc MAC out #%d", active_state->p_send.seqnr));
1.25 markus 929: }
930: /* encrypt packet and append to output buffer. */
1.180 markus 931: cp = buffer_append_space(&active_state->output, len + authlen);
1.161 andreas 932: cipher_crypt(&active_state->send_context, cp,
933: buffer_ptr(&active_state->outgoing_packet),
1.180 markus 934: len - aadlen, aadlen, authlen);
1.25 markus 935: /* append unencrypted MAC */
1.178 markus 936: if (mac && mac->enabled) {
937: if (mac->etm) {
938: /* EtM: compute mac over aadlen + cipher text */
939: macbuf = mac_compute(mac,
940: active_state->p_send.seqnr, cp, len);
941: DBG(debug("done calc MAC(EtM) out #%d",
942: active_state->p_send.seqnr));
943: }
1.161 andreas 944: buffer_append(&active_state->output, macbuf, mac->mac_len);
1.178 markus 945: }
1.25 markus 946: #ifdef PACKET_DEBUG
947: fprintf(stderr, "encrypted: ");
1.161 andreas 948: buffer_dump(&active_state->output);
1.25 markus 949: #endif
1.29 markus 950: /* increment sequence number for outgoing packets */
1.161 andreas 951: if (++active_state->p_send.seqnr == 0)
1.106 itojun 952: logit("outgoing seqnr wraps around");
1.161 andreas 953: if (++active_state->p_send.packets == 0)
1.105 markus 954: if (!(datafellows & SSH_BUG_NOREKEY))
955: fatal("XXX too many packets with same key");
1.178 markus 956: active_state->p_send.blocks += len / block_size;
957: active_state->p_send.bytes += len;
1.161 andreas 958: buffer_clear(&active_state->outgoing_packet);
1.25 markus 959:
1.57 markus 960: if (type == SSH2_MSG_NEWKEYS)
961: set_newkeys(MODE_OUT);
1.161 andreas 962: else if (type == SSH2_MSG_USERAUTH_SUCCESS && active_state->server_side)
1.118 markus 963: packet_enable_delayed_compress();
1.25 markus 964: }
965:
1.105 markus 966: static void
967: packet_send2(void)
968: {
969: struct packet *p;
970: u_char type, *cp;
971:
1.161 andreas 972: cp = buffer_ptr(&active_state->outgoing_packet);
1.105 markus 973: type = cp[5];
974:
975: /* during rekeying we can only send key exchange messages */
1.165 andreas 976: if (active_state->rekeying) {
1.175 markus 977: if ((type < SSH2_MSG_TRANSPORT_MIN) ||
978: (type > SSH2_MSG_TRANSPORT_MAX) ||
979: (type == SSH2_MSG_SERVICE_REQUEST) ||
980: (type == SSH2_MSG_SERVICE_ACCEPT)) {
1.105 markus 981: debug("enqueue packet: %u", type);
982: p = xmalloc(sizeof(*p));
983: p->type = type;
1.161 andreas 984: memcpy(&p->payload, &active_state->outgoing_packet,
985: sizeof(Buffer));
986: buffer_init(&active_state->outgoing_packet);
987: TAILQ_INSERT_TAIL(&active_state->outgoing, p, next);
1.105 markus 988: return;
989: }
990: }
991:
992: /* rekeying starts with sending KEXINIT */
993: if (type == SSH2_MSG_KEXINIT)
1.165 andreas 994: active_state->rekeying = 1;
1.105 markus 995:
996: packet_send2_wrapped();
997:
998: /* after a NEWKEYS message we can send the complete queue */
999: if (type == SSH2_MSG_NEWKEYS) {
1.165 andreas 1000: active_state->rekeying = 0;
1.161 andreas 1001: while ((p = TAILQ_FIRST(&active_state->outgoing))) {
1.105 markus 1002: type = p->type;
1003: debug("dequeue packet: %u", type);
1.161 andreas 1004: buffer_free(&active_state->outgoing_packet);
1005: memcpy(&active_state->outgoing_packet, &p->payload,
1.105 markus 1006: sizeof(Buffer));
1.161 andreas 1007: TAILQ_REMOVE(&active_state->outgoing, p, next);
1.105 markus 1008: xfree(p);
1009: packet_send2_wrapped();
1010: }
1011: }
1012: }
1013:
1.25 markus 1014: void
1.73 itojun 1015: packet_send(void)
1.25 markus 1016: {
1.62 markus 1017: if (compat20)
1.25 markus 1018: packet_send2();
1019: else
1020: packet_send1();
1021: DBG(debug("packet_send done"));
1022: }
1023:
1024: /*
1.16 markus 1025: * Waits until a packet has been received, and returns its type. Note that
1026: * no other data is processed until this returns, so this function should not
1027: * be used during the interactive session.
1028: */
1.1 deraadt 1029:
1.2 provos 1030: int
1.82 markus 1031: packet_read_seqnr(u_int32_t *seqnr_p)
1.1 deraadt 1032: {
1.163 andreas 1033: int type, len, ret, ms_remain, cont;
1.56 millert 1034: fd_set *setp;
1.14 markus 1035: char buf[8192];
1.155 deraadt 1036: struct timeval timeout, start, *timeoutp = NULL;
1037:
1.25 markus 1038: DBG(debug("packet_read()"));
1.14 markus 1039:
1.161 andreas 1040: setp = (fd_set *)xcalloc(howmany(active_state->connection_in + 1,
1041: NFDBITS), sizeof(fd_mask));
1.56 millert 1042:
1.14 markus 1043: /* Since we are blocking, ensure that all written packets have been sent. */
1044: packet_write_wait();
1045:
1046: /* Stay in the loop until we have received a complete packet. */
1047: for (;;) {
1048: /* Try to read a packet from the buffer. */
1.82 markus 1049: type = packet_read_poll_seqnr(seqnr_p);
1.62 markus 1050: if (!compat20 && (
1.32 markus 1051: type == SSH_SMSG_SUCCESS
1.14 markus 1052: || type == SSH_SMSG_FAILURE
1053: || type == SSH_CMSG_EOF
1.32 markus 1054: || type == SSH_CMSG_EXIT_CONFIRMATION))
1.79 markus 1055: packet_check_eom();
1.14 markus 1056: /* If we got a packet, return it. */
1.56 millert 1057: if (type != SSH_MSG_NONE) {
1058: xfree(setp);
1.14 markus 1059: return type;
1.56 millert 1060: }
1.16 markus 1061: /*
1062: * Otherwise, wait for some data to arrive, add it to the
1063: * buffer, and try again.
1064: */
1.161 andreas 1065: memset(setp, 0, howmany(active_state->connection_in + 1,
1066: NFDBITS) * sizeof(fd_mask));
1067: FD_SET(active_state->connection_in, setp);
1.16 markus 1068:
1.161 andreas 1069: if (active_state->packet_timeout_ms > 0) {
1070: ms_remain = active_state->packet_timeout_ms;
1.154 dtucker 1071: timeoutp = &timeout;
1072: }
1.14 markus 1073: /* Wait for some data to arrive. */
1.154 dtucker 1074: for (;;) {
1.161 andreas 1075: if (active_state->packet_timeout_ms != -1) {
1.154 dtucker 1076: ms_to_timeval(&timeout, ms_remain);
1077: gettimeofday(&start, NULL);
1078: }
1.161 andreas 1079: if ((ret = select(active_state->connection_in + 1, setp,
1080: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1081: break;
1.161 andreas 1082: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1083: break;
1.161 andreas 1084: if (active_state->packet_timeout_ms == -1)
1.154 dtucker 1085: continue;
1086: ms_subtract_diff(&start, &ms_remain);
1087: if (ms_remain <= 0) {
1088: ret = 0;
1089: break;
1090: }
1091: }
1092: if (ret == 0) {
1093: logit("Connection to %.200s timed out while "
1094: "waiting to read", get_remote_ipaddr());
1095: cleanup_exit(255);
1096: }
1.14 markus 1097: /* Read data from the socket. */
1.163 andreas 1098: do {
1099: cont = 0;
1100: len = roaming_read(active_state->connection_in, buf,
1101: sizeof(buf), &cont);
1102: } while (len == 0 && cont);
1.18 markus 1103: if (len == 0) {
1.106 itojun 1104: logit("Connection closed by %.200s", get_remote_ipaddr());
1.112 markus 1105: cleanup_exit(255);
1.18 markus 1106: }
1.14 markus 1107: if (len < 0)
1108: fatal("Read from socket failed: %.100s", strerror(errno));
1109: /* Append it to the buffer. */
1110: packet_process_incoming(buf, len);
1111: }
1112: /* NOTREACHED */
1.1 deraadt 1113: }
1114:
1.77 djm 1115: int
1.82 markus 1116: packet_read(void)
1.77 djm 1117: {
1.82 markus 1118: return packet_read_seqnr(NULL);
1.77 djm 1119: }
1120:
1.16 markus 1121: /*
1122: * Waits until a packet has been received, verifies that its type matches
1123: * that given, and gives a fatal error and exits if there is a mismatch.
1124: */
1.1 deraadt 1125:
1.2 provos 1126: void
1.82 markus 1127: packet_read_expect(int expected_type)
1.1 deraadt 1128: {
1.14 markus 1129: int type;
1.1 deraadt 1130:
1.82 markus 1131: type = packet_read();
1.14 markus 1132: if (type != expected_type)
1133: packet_disconnect("Protocol error: expected packet type %d, got %d",
1.25 markus 1134: expected_type, type);
1.1 deraadt 1135: }
1136:
1137: /* Checks if a full packet is available in the data received so far via
1.14 markus 1138: * packet_process_incoming. If so, reads the packet; otherwise returns
1139: * SSH_MSG_NONE. This does not wait for data from the connection.
1140: *
1.150 dtucker 1141: * SSH_MSG_DISCONNECT is handled specially here. Also,
1142: * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1143: * to higher levels.
1.14 markus 1144: */
1.1 deraadt 1145:
1.68 itojun 1146: static int
1.82 markus 1147: packet_read_poll1(void)
1.1 deraadt 1148: {
1.40 markus 1149: u_int len, padded_len;
1.89 markus 1150: u_char *cp, type;
1.40 markus 1151: u_int checksum, stored_checksum;
1.14 markus 1152:
1153: /* Check if input size is less than minimum packet size. */
1.161 andreas 1154: if (buffer_len(&active_state->input) < 4 + 8)
1.14 markus 1155: return SSH_MSG_NONE;
1156: /* Get length of incoming packet. */
1.161 andreas 1157: cp = buffer_ptr(&active_state->input);
1.131 djm 1158: len = get_u32(cp);
1.14 markus 1159: if (len < 1 + 2 + 2 || len > 256 * 1024)
1.98 markus 1160: packet_disconnect("Bad packet length %u.", len);
1.14 markus 1161: padded_len = (len + 8) & ~7;
1162:
1163: /* Check if the packet has been entirely received. */
1.161 andreas 1164: if (buffer_len(&active_state->input) < 4 + padded_len)
1.14 markus 1165: return SSH_MSG_NONE;
1166:
1167: /* The entire packet is in buffer. */
1168:
1169: /* Consume packet length. */
1.161 andreas 1170: buffer_consume(&active_state->input, 4);
1.14 markus 1171:
1.62 markus 1172: /*
1173: * Cryptographic attack detector for ssh
1174: * (C)1998 CORE-SDI, Buenos Aires Argentina
1175: * Ariel Futoransky(futo@core-sdi.com)
1176: */
1.161 andreas 1177: if (!active_state->receive_context.plaintext) {
1178: switch (detect_attack(buffer_ptr(&active_state->input),
1179: padded_len)) {
1.144 djm 1180: case DEATTACK_DETECTED:
1181: packet_disconnect("crc32 compensation attack: "
1182: "network attack detected");
1183: case DEATTACK_DOS_DETECTED:
1184: packet_disconnect("deattack denial of "
1185: "service detected");
1186: }
1187: }
1.62 markus 1188:
1189: /* Decrypt data to incoming_packet. */
1.161 andreas 1190: buffer_clear(&active_state->incoming_packet);
1191: cp = buffer_append_space(&active_state->incoming_packet, padded_len);
1192: cipher_crypt(&active_state->receive_context, cp,
1.180 markus 1193: buffer_ptr(&active_state->input), padded_len, 0, 0);
1.62 markus 1194:
1.161 andreas 1195: buffer_consume(&active_state->input, padded_len);
1.1 deraadt 1196:
1197: #ifdef PACKET_DEBUG
1.14 markus 1198: fprintf(stderr, "read_poll plain: ");
1.161 andreas 1199: buffer_dump(&active_state->incoming_packet);
1.1 deraadt 1200: #endif
1201:
1.14 markus 1202: /* Compute packet checksum. */
1.161 andreas 1203: checksum = ssh_crc32(buffer_ptr(&active_state->incoming_packet),
1204: buffer_len(&active_state->incoming_packet) - 4);
1.14 markus 1205:
1206: /* Skip padding. */
1.161 andreas 1207: buffer_consume(&active_state->incoming_packet, 8 - len % 8);
1.14 markus 1208:
1209: /* Test check bytes. */
1.161 andreas 1210: if (len != buffer_len(&active_state->incoming_packet))
1.77 djm 1211: packet_disconnect("packet_read_poll1: len %d != buffer_len %d.",
1.161 andreas 1212: len, buffer_len(&active_state->incoming_packet));
1.14 markus 1213:
1.161 andreas 1214: cp = (u_char *)buffer_ptr(&active_state->incoming_packet) + len - 4;
1.131 djm 1215: stored_checksum = get_u32(cp);
1.14 markus 1216: if (checksum != stored_checksum)
1217: packet_disconnect("Corrupted check bytes on input.");
1.161 andreas 1218: buffer_consume_end(&active_state->incoming_packet, 4);
1.14 markus 1219:
1.161 andreas 1220: if (active_state->packet_compression) {
1221: buffer_clear(&active_state->compression_buffer);
1222: buffer_uncompress(&active_state->incoming_packet,
1223: &active_state->compression_buffer);
1224: buffer_clear(&active_state->incoming_packet);
1225: buffer_append(&active_state->incoming_packet,
1226: buffer_ptr(&active_state->compression_buffer),
1227: buffer_len(&active_state->compression_buffer));
1228: }
1229: active_state->p_read.packets++;
1230: active_state->p_read.bytes += padded_len + 4;
1231: type = buffer_get_char(&active_state->incoming_packet);
1.116 markus 1232: if (type < SSH_MSG_MIN || type > SSH_MSG_MAX)
1233: packet_disconnect("Invalid ssh1 packet type: %d", type);
1.62 markus 1234: return type;
1.1 deraadt 1235: }
1.14 markus 1236:
1.68 itojun 1237: static int
1.82 markus 1238: packet_read_poll2(u_int32_t *seqnr_p)
1.25 markus 1239: {
1.40 markus 1240: u_int padlen, need;
1.178 markus 1241: u_char *macbuf = NULL, *cp, type;
1.180 markus 1242: u_int maclen, authlen = 0, aadlen = 0, block_size;
1.25 markus 1243: Enc *enc = NULL;
1244: Mac *mac = NULL;
1245: Comp *comp = NULL;
1246:
1.161 andreas 1247: if (active_state->packet_discard)
1.159 markus 1248: return SSH_MSG_NONE;
1249:
1.161 andreas 1250: if (active_state->newkeys[MODE_IN] != NULL) {
1251: enc = &active_state->newkeys[MODE_IN]->enc;
1252: mac = &active_state->newkeys[MODE_IN]->mac;
1253: comp = &active_state->newkeys[MODE_IN]->comp;
1.180 markus 1254: /* disable mac for authenticated encryption */
1255: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1256: mac = NULL;
1.25 markus 1257: }
1258: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1259: block_size = enc ? enc->block_size : 8;
1.180 markus 1260: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1261:
1.178 markus 1262: if (aadlen && active_state->packlen == 0) {
1263: if (buffer_len(&active_state->input) < 4)
1264: return SSH_MSG_NONE;
1265: cp = buffer_ptr(&active_state->input);
1266: active_state->packlen = get_u32(cp);
1267: if (active_state->packlen < 1 + 4 ||
1268: active_state->packlen > PACKET_MAX_SIZE) {
1269: #ifdef PACKET_DEBUG
1270: buffer_dump(&active_state->input);
1271: #endif
1272: logit("Bad packet length %u.", active_state->packlen);
1273: packet_disconnect("Packet corrupt");
1274: }
1.179 markus 1275: buffer_clear(&active_state->incoming_packet);
1.178 markus 1276: } else if (active_state->packlen == 0) {
1.25 markus 1277: /*
1278: * check if input size is less than the cipher block size,
1279: * decrypt first block and extract length of incoming packet
1280: */
1.161 andreas 1281: if (buffer_len(&active_state->input) < block_size)
1.25 markus 1282: return SSH_MSG_NONE;
1.161 andreas 1283: buffer_clear(&active_state->incoming_packet);
1284: cp = buffer_append_space(&active_state->incoming_packet,
1.25 markus 1285: block_size);
1.161 andreas 1286: cipher_crypt(&active_state->receive_context, cp,
1.180 markus 1287: buffer_ptr(&active_state->input), block_size, 0, 0);
1.161 andreas 1288: cp = buffer_ptr(&active_state->incoming_packet);
1289: active_state->packlen = get_u32(cp);
1290: if (active_state->packlen < 1 + 4 ||
1291: active_state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1292: #ifdef PACKET_DEBUG
1.161 andreas 1293: buffer_dump(&active_state->incoming_packet);
1.110 markus 1294: #endif
1.161 andreas 1295: logit("Bad packet length %u.", active_state->packlen);
1296: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1297: PACKET_MAX_SIZE);
1298: return SSH_MSG_NONE;
1.25 markus 1299: }
1.161 andreas 1300: buffer_consume(&active_state->input, block_size);
1.25 markus 1301: }
1.178 markus 1302: DBG(debug("input: packet len %u", active_state->packlen+4));
1303: if (aadlen) {
1304: /* only the payload is encrypted */
1305: need = active_state->packlen;
1306: } else {
1307: /*
1308: * the payload size and the payload are encrypted, but we
1309: * have a partial packet of block_size bytes
1310: */
1311: need = 4 + active_state->packlen - block_size;
1312: }
1.180 markus 1313: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1314: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1315: if (need % block_size != 0) {
1316: logit("padding error: need %d block %d mod %d",
1.25 markus 1317: need, block_size, need % block_size);
1.161 andreas 1318: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1319: PACKET_MAX_SIZE - block_size);
1320: return SSH_MSG_NONE;
1.158 markus 1321: }
1.25 markus 1322: /*
1323: * check if the entire packet has been received and
1.178 markus 1324: * decrypt into incoming_packet:
1325: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1326: * 'need' bytes are encrypted, followed by either
1327: * 'authlen' bytes of authentication tag or
1.178 markus 1328: * 'maclen' bytes of message authentication code.
1.25 markus 1329: */
1.180 markus 1330: if (buffer_len(&active_state->input) < aadlen + need + authlen + maclen)
1.25 markus 1331: return SSH_MSG_NONE;
1332: #ifdef PACKET_DEBUG
1333: fprintf(stderr, "read_poll enc/full: ");
1.161 andreas 1334: buffer_dump(&active_state->input);
1.25 markus 1335: #endif
1.178 markus 1336: /* EtM: compute mac over encrypted input */
1337: if (mac && mac->enabled && mac->etm)
1338: macbuf = mac_compute(mac, active_state->p_read.seqnr,
1339: buffer_ptr(&active_state->input), aadlen + need);
1340: cp = buffer_append_space(&active_state->incoming_packet, aadlen + need);
1.161 andreas 1341: cipher_crypt(&active_state->receive_context, cp,
1.180 markus 1342: buffer_ptr(&active_state->input), need, aadlen, authlen);
1343: buffer_consume(&active_state->input, aadlen + need + authlen);
1.25 markus 1344: /*
1345: * compute MAC over seqnr and packet,
1346: * increment sequence number for incoming packet
1347: */
1.29 markus 1348: if (mac && mac->enabled) {
1.178 markus 1349: if (!mac->etm)
1350: macbuf = mac_compute(mac, active_state->p_read.seqnr,
1351: buffer_ptr(&active_state->incoming_packet),
1352: buffer_len(&active_state->incoming_packet));
1.168 djm 1353: if (timingsafe_bcmp(macbuf, buffer_ptr(&active_state->input),
1.161 andreas 1354: mac->mac_len) != 0) {
1.159 markus 1355: logit("Corrupted MAC on input.");
1356: if (need > PACKET_MAX_SIZE)
1357: fatal("internal error need %d", need);
1.161 andreas 1358: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1359: PACKET_MAX_SIZE - need);
1360: return SSH_MSG_NONE;
1361: }
1362:
1.161 andreas 1363: DBG(debug("MAC #%d ok", active_state->p_read.seqnr));
1364: buffer_consume(&active_state->input, mac->mac_len);
1.25 markus 1365: }
1.159 markus 1366: /* XXX now it's safe to use fatal/packet_disconnect */
1.77 djm 1367: if (seqnr_p != NULL)
1.161 andreas 1368: *seqnr_p = active_state->p_read.seqnr;
1369: if (++active_state->p_read.seqnr == 0)
1.106 itojun 1370: logit("incoming seqnr wraps around");
1.161 andreas 1371: if (++active_state->p_read.packets == 0)
1.105 markus 1372: if (!(datafellows & SSH_BUG_NOREKEY))
1373: fatal("XXX too many packets with same key");
1.161 andreas 1374: active_state->p_read.blocks += (active_state->packlen + 4) / block_size;
1375: active_state->p_read.bytes += active_state->packlen + 4;
1.25 markus 1376:
1377: /* get padlen */
1.161 andreas 1378: cp = buffer_ptr(&active_state->incoming_packet);
1.89 markus 1379: padlen = cp[4];
1.25 markus 1380: DBG(debug("input: padlen %d", padlen));
1381: if (padlen < 4)
1382: packet_disconnect("Corrupted padlen %d on input.", padlen);
1383:
1384: /* skip packet size + padlen, discard padding */
1.161 andreas 1385: buffer_consume(&active_state->incoming_packet, 4 + 1);
1386: buffer_consume_end(&active_state->incoming_packet, padlen);
1.25 markus 1387:
1.161 andreas 1388: DBG(debug("input: len before de-compress %d",
1389: buffer_len(&active_state->incoming_packet)));
1.25 markus 1390: if (comp && comp->enabled) {
1.161 andreas 1391: buffer_clear(&active_state->compression_buffer);
1392: buffer_uncompress(&active_state->incoming_packet,
1393: &active_state->compression_buffer);
1394: buffer_clear(&active_state->incoming_packet);
1395: buffer_append(&active_state->incoming_packet,
1396: buffer_ptr(&active_state->compression_buffer),
1397: buffer_len(&active_state->compression_buffer));
1.97 deraadt 1398: DBG(debug("input: len after de-compress %d",
1.161 andreas 1399: buffer_len(&active_state->incoming_packet)));
1.25 markus 1400: }
1401: /*
1402: * get packet type, implies consume.
1403: * return length of payload (without type field)
1404: */
1.161 andreas 1405: type = buffer_get_char(&active_state->incoming_packet);
1.116 markus 1406: if (type < SSH2_MSG_MIN || type >= SSH2_MSG_LOCAL_MIN)
1407: packet_disconnect("Invalid ssh2 packet type: %d", type);
1.57 markus 1408: if (type == SSH2_MSG_NEWKEYS)
1409: set_newkeys(MODE_IN);
1.161 andreas 1410: else if (type == SSH2_MSG_USERAUTH_SUCCESS &&
1411: !active_state->server_side)
1.118 markus 1412: packet_enable_delayed_compress();
1.25 markus 1413: #ifdef PACKET_DEBUG
1.55 deraadt 1414: fprintf(stderr, "read/plain[%d]:\r\n", type);
1.161 andreas 1415: buffer_dump(&active_state->incoming_packet);
1.25 markus 1416: #endif
1.62 markus 1417: /* reset for next packet */
1.161 andreas 1418: active_state->packlen = 0;
1.62 markus 1419: return type;
1.25 markus 1420: }
1421:
1422: int
1.82 markus 1423: packet_read_poll_seqnr(u_int32_t *seqnr_p)
1.25 markus 1424: {
1.96 deraadt 1425: u_int reason, seqnr;
1.62 markus 1426: u_char type;
1.25 markus 1427: char *msg;
1.62 markus 1428:
1.25 markus 1429: for (;;) {
1.62 markus 1430: if (compat20) {
1.82 markus 1431: type = packet_read_poll2(seqnr_p);
1.153 djm 1432: if (type) {
1.161 andreas 1433: active_state->keep_alive_timeouts = 0;
1.25 markus 1434: DBG(debug("received packet type %d", type));
1.153 djm 1435: }
1.74 deraadt 1436: switch (type) {
1.150 dtucker 1437: case SSH2_MSG_IGNORE:
1.151 dtucker 1438: debug3("Received SSH2_MSG_IGNORE");
1.150 dtucker 1439: break;
1.25 markus 1440: case SSH2_MSG_DEBUG:
1441: packet_get_char();
1442: msg = packet_get_string(NULL);
1443: debug("Remote: %.900s", msg);
1444: xfree(msg);
1445: msg = packet_get_string(NULL);
1446: xfree(msg);
1447: break;
1448: case SSH2_MSG_DISCONNECT:
1449: reason = packet_get_int();
1450: msg = packet_get_string(NULL);
1.182 djm 1451: /* Ignore normal client exit notifications */
1452: do_log2(active_state->server_side &&
1453: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1454: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1455: "Received disconnect from %s: %u: %.400s",
1.96 deraadt 1456: get_remote_ipaddr(), reason, msg);
1.25 markus 1457: xfree(msg);
1.112 markus 1458: cleanup_exit(255);
1.84 markus 1459: break;
1460: case SSH2_MSG_UNIMPLEMENTED:
1461: seqnr = packet_get_int();
1.96 deraadt 1462: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1463: seqnr);
1.150 dtucker 1464: break;
1.25 markus 1465: default:
1466: return type;
1.48 stevesk 1467: }
1.25 markus 1468: } else {
1.82 markus 1469: type = packet_read_poll1();
1.74 deraadt 1470: switch (type) {
1.25 markus 1471: case SSH_MSG_IGNORE:
1472: break;
1473: case SSH_MSG_DEBUG:
1474: msg = packet_get_string(NULL);
1475: debug("Remote: %.900s", msg);
1476: xfree(msg);
1477: break;
1478: case SSH_MSG_DISCONNECT:
1479: msg = packet_get_string(NULL);
1.181 djm 1480: error("Received disconnect from %s: %.400s",
1.96 deraadt 1481: get_remote_ipaddr(), msg);
1.112 markus 1482: cleanup_exit(255);
1.25 markus 1483: break;
1484: default:
1.62 markus 1485: if (type)
1.25 markus 1486: DBG(debug("received packet type %d", type));
1487: return type;
1.48 stevesk 1488: }
1.25 markus 1489: }
1490: }
1491: }
1492:
1.16 markus 1493: /*
1494: * Buffers the given amount of input characters. This is intended to be used
1495: * together with packet_read_poll.
1496: */
1.1 deraadt 1497:
1.2 provos 1498: void
1.40 markus 1499: packet_process_incoming(const char *buf, u_int len)
1.1 deraadt 1500: {
1.161 andreas 1501: if (active_state->packet_discard) {
1502: active_state->keep_alive_timeouts = 0; /* ?? */
1503: if (len >= active_state->packet_discard)
1.159 markus 1504: packet_stop_discard();
1.161 andreas 1505: active_state->packet_discard -= len;
1.159 markus 1506: return;
1507: }
1.161 andreas 1508: buffer_append(&active_state->input, buf, len);
1.1 deraadt 1509: }
1510:
1511: /* Returns a character from the packet. */
1512:
1.40 markus 1513: u_int
1.73 itojun 1514: packet_get_char(void)
1.1 deraadt 1515: {
1.14 markus 1516: char ch;
1.97 deraadt 1517:
1.161 andreas 1518: buffer_get(&active_state->incoming_packet, &ch, 1);
1.40 markus 1519: return (u_char) ch;
1.1 deraadt 1520: }
1521:
1522: /* Returns an integer from the packet data. */
1523:
1.40 markus 1524: u_int
1.73 itojun 1525: packet_get_int(void)
1.1 deraadt 1526: {
1.161 andreas 1527: return buffer_get_int(&active_state->incoming_packet);
1.162 andreas 1528: }
1529:
1530: /* Returns an 64 bit integer from the packet data. */
1531:
1532: u_int64_t
1533: packet_get_int64(void)
1534: {
1535: return buffer_get_int64(&active_state->incoming_packet);
1.1 deraadt 1536: }
1537:
1.16 markus 1538: /*
1539: * Returns an arbitrary precision integer from the packet data. The integer
1540: * must have been initialized before this call.
1541: */
1.1 deraadt 1542:
1.2 provos 1543: void
1.80 markus 1544: packet_get_bignum(BIGNUM * value)
1.1 deraadt 1545: {
1.161 andreas 1546: buffer_get_bignum(&active_state->incoming_packet, value);
1.24 markus 1547: }
1548:
1549: void
1.80 markus 1550: packet_get_bignum2(BIGNUM * value)
1.24 markus 1551: {
1.161 andreas 1552: buffer_get_bignum2(&active_state->incoming_packet, value);
1.170 djm 1553: }
1554:
1555: void
1556: packet_get_ecpoint(const EC_GROUP *curve, EC_POINT *point)
1557: {
1558: buffer_get_ecpoint(&active_state->incoming_packet, curve, point);
1.24 markus 1559: }
1560:
1.76 stevesk 1561: void *
1.117 djm 1562: packet_get_raw(u_int *length_ptr)
1.24 markus 1563: {
1.161 andreas 1564: u_int bytes = buffer_len(&active_state->incoming_packet);
1.97 deraadt 1565:
1.24 markus 1566: if (length_ptr != NULL)
1567: *length_ptr = bytes;
1.161 andreas 1568: return buffer_ptr(&active_state->incoming_packet);
1.28 markus 1569: }
1570:
1571: int
1572: packet_remaining(void)
1573: {
1.161 andreas 1574: return buffer_len(&active_state->incoming_packet);
1.1 deraadt 1575: }
1576:
1.16 markus 1577: /*
1578: * Returns a string from the packet data. The string is allocated using
1579: * xmalloc; it is the responsibility of the calling program to free it when
1580: * no longer needed. The length_ptr argument may be NULL, or point to an
1581: * integer into which the length of the string is stored.
1582: */
1.1 deraadt 1583:
1.76 stevesk 1584: void *
1.40 markus 1585: packet_get_string(u_int *length_ptr)
1.1 deraadt 1586: {
1.161 andreas 1587: return buffer_get_string(&active_state->incoming_packet, length_ptr);
1.152 markus 1588: }
1589:
1590: void *
1591: packet_get_string_ptr(u_int *length_ptr)
1592: {
1.161 andreas 1593: return buffer_get_string_ptr(&active_state->incoming_packet, length_ptr);
1.169 djm 1594: }
1595:
1596: /* Ensures the returned string has no embedded \0 characters in it. */
1597: char *
1598: packet_get_cstring(u_int *length_ptr)
1599: {
1600: return buffer_get_cstring(&active_state->incoming_packet, length_ptr);
1.1 deraadt 1601: }
1602:
1.16 markus 1603: /*
1604: * Sends a diagnostic message from the server to the client. This message
1605: * can be sent at any time (but not while constructing another message). The
1606: * message is printed immediately, but only if the client is being executed
1607: * in verbose mode. These messages are primarily intended to ease debugging
1608: * authentication problems. The length of the formatted message must not
1609: * exceed 1024 bytes. This will automatically call packet_write_wait.
1610: */
1.1 deraadt 1611:
1.2 provos 1612: void
1.14 markus 1613: packet_send_debug(const char *fmt,...)
1.1 deraadt 1614: {
1.14 markus 1615: char buf[1024];
1616: va_list args;
1.39 markus 1617:
1618: if (compat20 && (datafellows & SSH_BUG_DEBUG))
1619: return;
1.14 markus 1620:
1621: va_start(args, fmt);
1622: vsnprintf(buf, sizeof(buf), fmt, args);
1623: va_end(args);
1624:
1.30 markus 1625: if (compat20) {
1626: packet_start(SSH2_MSG_DEBUG);
1627: packet_put_char(0); /* bool: always display */
1628: packet_put_cstring(buf);
1629: packet_put_cstring("");
1630: } else {
1631: packet_start(SSH_MSG_DEBUG);
1632: packet_put_cstring(buf);
1633: }
1.14 markus 1634: packet_send();
1635: packet_write_wait();
1.1 deraadt 1636: }
1637:
1.16 markus 1638: /*
1639: * Logs the error plus constructs and sends a disconnect packet, closes the
1640: * connection, and exits. This function never returns. The error message
1641: * should not contain a newline. The length of the formatted message must
1642: * not exceed 1024 bytes.
1643: */
1.1 deraadt 1644:
1.2 provos 1645: void
1.14 markus 1646: packet_disconnect(const char *fmt,...)
1.1 deraadt 1647: {
1.14 markus 1648: char buf[1024];
1649: va_list args;
1650: static int disconnecting = 0;
1.97 deraadt 1651:
1.14 markus 1652: if (disconnecting) /* Guard against recursive invocations. */
1653: fatal("packet_disconnect called recursively.");
1654: disconnecting = 1;
1655:
1.16 markus 1656: /*
1657: * Format the message. Note that the caller must make sure the
1658: * message is of limited size.
1659: */
1.14 markus 1660: va_start(args, fmt);
1661: vsnprintf(buf, sizeof(buf), fmt, args);
1662: va_end(args);
1663:
1.99 markus 1664: /* Display the error locally */
1.106 itojun 1665: logit("Disconnecting: %.100s", buf);
1.99 markus 1666:
1.14 markus 1667: /* Send the disconnect message to the other side, and wait for it to get sent. */
1.25 markus 1668: if (compat20) {
1669: packet_start(SSH2_MSG_DISCONNECT);
1670: packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR);
1671: packet_put_cstring(buf);
1672: packet_put_cstring("");
1673: } else {
1674: packet_start(SSH_MSG_DISCONNECT);
1.65 markus 1675: packet_put_cstring(buf);
1.25 markus 1676: }
1.14 markus 1677: packet_send();
1678: packet_write_wait();
1679:
1680: /* Stop listening for connections. */
1.67 markus 1681: channel_close_all();
1.14 markus 1682:
1683: /* Close the connection. */
1684: packet_close();
1.112 markus 1685: cleanup_exit(255);
1.1 deraadt 1686: }
1687:
1.16 markus 1688: /* Checks if there is any buffered output, and tries to write some of the output. */
1.1 deraadt 1689:
1.2 provos 1690: void
1.73 itojun 1691: packet_write_poll(void)
1.1 deraadt 1692: {
1.161 andreas 1693: int len = buffer_len(&active_state->output);
1.163 andreas 1694: int cont;
1.97 deraadt 1695:
1.14 markus 1696: if (len > 0) {
1.163 andreas 1697: cont = 0;
1698: len = roaming_write(active_state->connection_out,
1699: buffer_ptr(&active_state->output), len, &cont);
1.156 djm 1700: if (len == -1) {
1701: if (errno == EINTR || errno == EAGAIN)
1.14 markus 1702: return;
1.156 djm 1703: fatal("Write failed: %.100s", strerror(errno));
1.14 markus 1704: }
1.163 andreas 1705: if (len == 0 && !cont)
1.156 djm 1706: fatal("Write connection closed");
1.161 andreas 1707: buffer_consume(&active_state->output, len);
1.14 markus 1708: }
1.1 deraadt 1709: }
1710:
1.16 markus 1711: /*
1712: * Calls packet_write_poll repeatedly until all pending output data has been
1713: * written.
1714: */
1.1 deraadt 1715:
1.2 provos 1716: void
1.73 itojun 1717: packet_write_wait(void)
1.1 deraadt 1718: {
1.56 millert 1719: fd_set *setp;
1.154 dtucker 1720: int ret, ms_remain;
1721: struct timeval start, timeout, *timeoutp = NULL;
1.56 millert 1722:
1.161 andreas 1723: setp = (fd_set *)xcalloc(howmany(active_state->connection_out + 1,
1724: NFDBITS), sizeof(fd_mask));
1.14 markus 1725: packet_write_poll();
1726: while (packet_have_data_to_write()) {
1.161 andreas 1727: memset(setp, 0, howmany(active_state->connection_out + 1,
1728: NFDBITS) * sizeof(fd_mask));
1729: FD_SET(active_state->connection_out, setp);
1.154 dtucker 1730:
1.161 andreas 1731: if (active_state->packet_timeout_ms > 0) {
1732: ms_remain = active_state->packet_timeout_ms;
1.154 dtucker 1733: timeoutp = &timeout;
1734: }
1735: for (;;) {
1.161 andreas 1736: if (active_state->packet_timeout_ms != -1) {
1.154 dtucker 1737: ms_to_timeval(&timeout, ms_remain);
1738: gettimeofday(&start, NULL);
1739: }
1.161 andreas 1740: if ((ret = select(active_state->connection_out + 1,
1741: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1742: break;
1.161 andreas 1743: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1744: break;
1.161 andreas 1745: if (active_state->packet_timeout_ms == -1)
1.154 dtucker 1746: continue;
1747: ms_subtract_diff(&start, &ms_remain);
1748: if (ms_remain <= 0) {
1749: ret = 0;
1750: break;
1751: }
1752: }
1753: if (ret == 0) {
1754: logit("Connection to %.200s timed out while "
1755: "waiting to write", get_remote_ipaddr());
1756: cleanup_exit(255);
1757: }
1.14 markus 1758: packet_write_poll();
1759: }
1.56 millert 1760: xfree(setp);
1.1 deraadt 1761: }
1762:
1763: /* Returns true if there is buffered data to write to the connection. */
1764:
1.2 provos 1765: int
1.73 itojun 1766: packet_have_data_to_write(void)
1.1 deraadt 1767: {
1.161 andreas 1768: return buffer_len(&active_state->output) != 0;
1.1 deraadt 1769: }
1770:
1771: /* Returns true if there is not too much data to write to the connection. */
1772:
1.2 provos 1773: int
1.73 itojun 1774: packet_not_very_much_data_to_write(void)
1.1 deraadt 1775: {
1.161 andreas 1776: if (active_state->interactive_mode)
1777: return buffer_len(&active_state->output) < 16384;
1.14 markus 1778: else
1.161 andreas 1779: return buffer_len(&active_state->output) < 128 * 1024;
1.1 deraadt 1780: }
1781:
1.102 markus 1782: static void
1.172 djm 1783: packet_set_tos(int tos)
1.101 markus 1784: {
1.173 djm 1785: if (!packet_connection_is_on_socket())
1.101 markus 1786: return;
1.173 djm 1787: switch (packet_connection_af()) {
1788: case AF_INET:
1789: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1790: if (setsockopt(active_state->connection_in,
1791: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
1792: error("setsockopt IP_TOS %d: %.100s:",
1793: tos, strerror(errno));
1794: break;
1795: case AF_INET6:
1796: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1797: if (setsockopt(active_state->connection_in,
1798: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
1799: error("setsockopt IPV6_TCLASS %d: %.100s:",
1800: tos, strerror(errno));
1801: break;
1802: }
1.101 markus 1803: }
1804:
1.1 deraadt 1805: /* Informs that the current session is interactive. Sets IP flags for that. */
1806:
1.2 provos 1807: void
1.172 djm 1808: packet_set_interactive(int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 1809: {
1.165 andreas 1810: if (active_state->set_interactive_called)
1.43 markus 1811: return;
1.165 andreas 1812: active_state->set_interactive_called = 1;
1.1 deraadt 1813:
1.14 markus 1814: /* Record that we are in interactive mode. */
1.161 andreas 1815: active_state->interactive_mode = interactive;
1.1 deraadt 1816:
1.19 markus 1817: /* Only set socket options if using a socket. */
1818: if (!packet_connection_is_on_socket())
1.14 markus 1819: return;
1.161 andreas 1820: set_nodelay(active_state->connection_in);
1.172 djm 1821: packet_set_tos(interactive ? qos_interactive : qos_bulk);
1.1 deraadt 1822: }
1823:
1824: /* Returns true if the current connection is interactive. */
1825:
1.2 provos 1826: int
1.73 itojun 1827: packet_is_interactive(void)
1.1 deraadt 1828: {
1.161 andreas 1829: return active_state->interactive_mode;
1.12 markus 1830: }
1831:
1.113 deraadt 1832: int
1.108 markus 1833: packet_set_maxsize(u_int s)
1.12 markus 1834: {
1.165 andreas 1835: if (active_state->set_maxsize_called) {
1.106 itojun 1836: logit("packet_set_maxsize: called twice: old %d new %d",
1.161 andreas 1837: active_state->max_packet_size, s);
1.14 markus 1838: return -1;
1839: }
1840: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 1841: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 1842: return -1;
1843: }
1.165 andreas 1844: active_state->set_maxsize_called = 1;
1.66 markus 1845: debug("packet_set_maxsize: setting to %d", s);
1.161 andreas 1846: active_state->max_packet_size = s;
1.14 markus 1847: return s;
1.53 markus 1848: }
1849:
1.161 andreas 1850: int
1851: packet_inc_alive_timeouts(void)
1852: {
1853: return ++active_state->keep_alive_timeouts;
1854: }
1855:
1856: void
1857: packet_set_alive_timeouts(int ka)
1858: {
1859: active_state->keep_alive_timeouts = ka;
1860: }
1861:
1862: u_int
1863: packet_get_maxsize(void)
1864: {
1865: return active_state->max_packet_size;
1866: }
1867:
1.71 markus 1868: /* roundup current message to pad bytes */
1869: void
1870: packet_add_padding(u_char pad)
1871: {
1.161 andreas 1872: active_state->extra_pad = pad;
1.71 markus 1873: }
1874:
1.53 markus 1875: /*
1876: * 9.2. Ignored Data Message
1.61 markus 1877: *
1.53 markus 1878: * byte SSH_MSG_IGNORE
1879: * string data
1.61 markus 1880: *
1.53 markus 1881: * All implementations MUST understand (and ignore) this message at any
1882: * time (after receiving the protocol version). No implementation is
1883: * required to send them. This message can be used as an additional
1884: * protection measure against advanced traffic analysis techniques.
1885: */
1.54 markus 1886: void
1887: packet_send_ignore(int nbytes)
1888: {
1.115 avsm 1889: u_int32_t rnd = 0;
1.54 markus 1890: int i;
1891:
1892: packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE);
1.53 markus 1893: packet_put_int(nbytes);
1.75 deraadt 1894: for (i = 0; i < nbytes; i++) {
1.53 markus 1895: if (i % 4 == 0)
1.115 avsm 1896: rnd = arc4random();
1.129 deraadt 1897: packet_put_char((u_char)rnd & 0xff);
1.115 avsm 1898: rnd >>= 8;
1.53 markus 1899: }
1.105 markus 1900: }
1901:
1.113 deraadt 1902: #define MAX_PACKETS (1U<<31)
1.105 markus 1903: int
1904: packet_need_rekeying(void)
1905: {
1906: if (datafellows & SSH_BUG_NOREKEY)
1907: return 0;
1908: return
1.161 andreas 1909: (active_state->p_send.packets > MAX_PACKETS) ||
1910: (active_state->p_read.packets > MAX_PACKETS) ||
1911: (active_state->max_blocks_out &&
1912: (active_state->p_send.blocks > active_state->max_blocks_out)) ||
1913: (active_state->max_blocks_in &&
1914: (active_state->p_read.blocks > active_state->max_blocks_in));
1.105 markus 1915: }
1916:
1917: void
1918: packet_set_rekey_limit(u_int32_t bytes)
1919: {
1.161 andreas 1920: active_state->rekey_limit = bytes;
1.118 markus 1921: }
1922:
1923: void
1924: packet_set_server(void)
1925: {
1.161 andreas 1926: active_state->server_side = 1;
1.118 markus 1927: }
1928:
1929: void
1930: packet_set_authenticated(void)
1931: {
1.161 andreas 1932: active_state->after_authentication = 1;
1933: }
1934:
1935: void *
1936: packet_get_input(void)
1937: {
1938: return (void *)&active_state->input;
1939: }
1940:
1941: void *
1942: packet_get_output(void)
1943: {
1944: return (void *)&active_state->output;
1945: }
1946:
1947: void *
1948: packet_get_newkeys(int mode)
1949: {
1950: return (void *)active_state->newkeys[mode];
1.166 andreas 1951: }
1952:
1953: /*
1954: * Save the state for the real connection, and use a separate state when
1955: * resuming a suspended connection.
1956: */
1957: void
1958: packet_backup_state(void)
1959: {
1960: struct session_state *tmp;
1961:
1962: close(active_state->connection_in);
1963: active_state->connection_in = -1;
1964: close(active_state->connection_out);
1965: active_state->connection_out = -1;
1966: if (backup_state)
1967: tmp = backup_state;
1968: else
1969: tmp = alloc_session_state();
1970: backup_state = active_state;
1971: active_state = tmp;
1972: }
1973:
1974: /*
1975: * Swap in the old state when resuming a connecion.
1976: */
1977: void
1978: packet_restore_state(void)
1979: {
1980: struct session_state *tmp;
1981: void *buf;
1982: u_int len;
1983:
1984: tmp = backup_state;
1985: backup_state = active_state;
1986: active_state = tmp;
1987: active_state->connection_in = backup_state->connection_in;
1988: backup_state->connection_in = -1;
1989: active_state->connection_out = backup_state->connection_out;
1990: backup_state->connection_out = -1;
1991: len = buffer_len(&backup_state->input);
1992: if (len > 0) {
1993: buf = buffer_ptr(&backup_state->input);
1994: buffer_append(&active_state->input, buf, len);
1995: buffer_clear(&backup_state->input);
1996: add_recv_bytes(len);
1997: }
1.1 deraadt 1998: }
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