Annotation of src/usr.bin/ssh/packet.c, Revision 1.162
1.162 ! andreas 1: /* $OpenBSD: packet.c,v 1.161 2009/05/25 06:48:01 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"
1.25 markus 76:
77: #ifdef PACKET_DEBUG
78: #define DBG(x) x
79: #else
80: #define DBG(x)
81: #endif
82:
1.159 markus 83: #define PACKET_MAX_SIZE (256 * 1024)
84:
1.161 andreas 85: struct packet_state {
86: u_int32_t seqnr;
87: u_int32_t packets;
88: u_int64_t blocks;
89: u_int64_t bytes;
90: };
91:
92: struct packet {
93: TAILQ_ENTRY(packet) next;
94: u_char type;
95: Buffer payload;
96: };
97:
98: struct session_state {
99: /*
100: * This variable contains the file descriptors used for
101: * communicating with the other side. connection_in is used for
102: * reading; connection_out for writing. These can be the same
103: * descriptor, in which case it is assumed to be a socket.
104: */
105: int connection_in;
106: int connection_out;
107:
108: /* Protocol flags for the remote side. */
109: u_int remote_protocol_flags;
1.1 deraadt 110:
1.161 andreas 111: /* Encryption context for receiving data. Only used for decryption. */
112: CipherContext receive_context;
1.1 deraadt 113:
1.161 andreas 114: /* Encryption context for sending data. Only used for encryption. */
115: CipherContext send_context;
1.14 markus 116:
1.161 andreas 117: /* Buffer for raw input data from the socket. */
118: Buffer input;
1.1 deraadt 119:
1.161 andreas 120: /* Buffer for raw output data going to the socket. */
121: Buffer output;
1.1 deraadt 122:
1.161 andreas 123: /* Buffer for the partial outgoing packet being constructed. */
124: Buffer outgoing_packet;
1.1 deraadt 125:
1.161 andreas 126: /* Buffer for the incoming packet currently being processed. */
127: Buffer incoming_packet;
1.1 deraadt 128:
1.161 andreas 129: /* Scratch buffer for packet compression/decompression. */
130: Buffer compression_buffer;
131: int compression_buffer_ready;
1.1 deraadt 132:
1.161 andreas 133: /*
134: * Flag indicating whether packet compression/decompression is
135: * enabled.
136: */
137: int packet_compression;
1.1 deraadt 138:
1.161 andreas 139: /* default maximum packet size */
140: u_int max_packet_size;
1.1 deraadt 141:
1.161 andreas 142: /* Flag indicating whether this module has been initialized. */
143: int initialized;
1.12 markus 144:
1.161 andreas 145: /* Set to true if the connection is interactive. */
146: int interactive_mode;
1.1 deraadt 147:
1.161 andreas 148: /* Set to true if we are the server side. */
149: int server_side;
1.1 deraadt 150:
1.161 andreas 151: /* Set to true if we are authenticated. */
152: int after_authentication;
1.118 markus 153:
1.161 andreas 154: int keep_alive_timeouts;
1.118 markus 155:
1.161 andreas 156: /* The maximum time that we will wait to send or receive a packet */
157: int packet_timeout_ms;
1.151 dtucker 158:
1.161 andreas 159: /* Session key information for Encryption and MAC */
160: Newkeys *newkeys[MODE_MAX];
161: struct packet_state p_read, p_send;
1.154 dtucker 162:
1.161 andreas 163: u_int64_t max_blocks_in, max_blocks_out;
164: u_int32_t rekey_limit;
1.105 markus 165:
1.161 andreas 166: /* Session key for protocol v1 */
167: u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
168: u_int ssh1_keylen;
1.25 markus 169:
1.161 andreas 170: /* roundup current message to extra_pad bytes */
171: u_char extra_pad;
1.95 markus 172:
1.161 andreas 173: /* XXX discard incoming data after MAC error */
174: u_int packet_discard;
175: Mac *packet_discard_mac;
1.71 markus 176:
1.161 andreas 177: /* Used in packet_read_poll2() */
178: u_int packlen;
1.159 markus 179:
1.161 andreas 180: TAILQ_HEAD(, packet) outgoing;
1.105 markus 181: };
1.161 andreas 182:
183: static struct session_state *active_state;
184:
185: static struct session_state *
186: alloc_session_state()
187: {
188: struct session_state *s = xcalloc(1, sizeof(*s));
189:
190: s->connection_in = -1;
191: s->connection_out = -1;
192: s->max_packet_size = 32768;
193: s->packet_timeout_ms = -1;
194: return s;
195: }
1.105 markus 196:
1.16 markus 197: /*
198: * Sets the descriptors used for communication. Disables encryption until
199: * packet_set_encryption_key is called.
200: */
1.2 provos 201: void
202: packet_set_connection(int fd_in, int fd_out)
1.1 deraadt 203: {
1.37 markus 204: Cipher *none = cipher_by_name("none");
1.97 deraadt 205:
1.37 markus 206: if (none == NULL)
207: fatal("packet_set_connection: cannot load cipher 'none'");
1.161 andreas 208: if (active_state == NULL)
209: active_state = alloc_session_state();
210: active_state->connection_in = fd_in;
211: active_state->connection_out = fd_out;
212: cipher_init(&active_state->send_context, none, (const u_char *)"",
1.113 deraadt 213: 0, NULL, 0, CIPHER_ENCRYPT);
1.161 andreas 214: cipher_init(&active_state->receive_context, none, (const u_char *)"",
1.113 deraadt 215: 0, NULL, 0, CIPHER_DECRYPT);
1.161 andreas 216: active_state->newkeys[MODE_IN] = active_state->newkeys[MODE_OUT] = NULL;
217: if (!active_state->initialized) {
218: active_state->initialized = 1;
219: buffer_init(&active_state->input);
220: buffer_init(&active_state->output);
221: buffer_init(&active_state->outgoing_packet);
222: buffer_init(&active_state->incoming_packet);
223: TAILQ_INIT(&active_state->outgoing);
224: active_state->p_send.packets = active_state->p_read.packets = 0;
1.14 markus 225: }
1.1 deraadt 226: }
227:
1.154 dtucker 228: void
229: packet_set_timeout(int timeout, int count)
230: {
231: if (timeout == 0 || count == 0) {
1.161 andreas 232: active_state->packet_timeout_ms = -1;
1.154 dtucker 233: return;
234: }
235: if ((INT_MAX / 1000) / count < timeout)
1.161 andreas 236: active_state->packet_timeout_ms = INT_MAX;
1.154 dtucker 237: else
1.161 andreas 238: active_state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 239: }
240:
1.159 markus 241: static void
242: packet_stop_discard(void)
243: {
1.161 andreas 244: if (active_state->packet_discard_mac) {
1.159 markus 245: char buf[1024];
246:
247: memset(buf, 'a', sizeof(buf));
1.161 andreas 248: while (buffer_len(&active_state->incoming_packet) <
249: PACKET_MAX_SIZE)
250: buffer_append(&active_state->incoming_packet, buf,
251: sizeof(buf));
252: (void) mac_compute(active_state->packet_discard_mac,
253: active_state->p_read.seqnr,
254: buffer_ptr(&active_state->incoming_packet),
1.159 markus 255: PACKET_MAX_SIZE);
256: }
257: logit("Finished discarding for %.200s", get_remote_ipaddr());
258: cleanup_exit(255);
259: }
260:
261: static void
262: packet_start_discard(Enc *enc, Mac *mac, u_int packet_length, u_int discard)
263: {
1.160 markus 264: if (enc == NULL || !cipher_is_cbc(enc->cipher))
1.159 markus 265: packet_disconnect("Packet corrupt");
266: if (packet_length != PACKET_MAX_SIZE && mac && mac->enabled)
1.161 andreas 267: active_state->packet_discard_mac = mac;
268: if (buffer_len(&active_state->input) >= discard)
1.159 markus 269: packet_stop_discard();
1.161 andreas 270: active_state->packet_discard = discard -
271: buffer_len(&active_state->input);
1.159 markus 272: }
273:
1.19 markus 274: /* Returns 1 if remote host is connected via socket, 0 if not. */
275:
276: int
1.73 itojun 277: packet_connection_is_on_socket(void)
1.19 markus 278: {
279: struct sockaddr_storage from, to;
280: socklen_t fromlen, tolen;
281:
282: /* filedescriptors in and out are the same, so it's a socket */
1.161 andreas 283: if (active_state->connection_in == active_state->connection_out)
1.19 markus 284: return 1;
285: fromlen = sizeof(from);
286: memset(&from, 0, sizeof(from));
1.161 andreas 287: if (getpeername(active_state->connection_in, (struct sockaddr *)&from,
288: &fromlen) < 0)
1.19 markus 289: return 0;
290: tolen = sizeof(to);
291: memset(&to, 0, sizeof(to));
1.161 andreas 292: if (getpeername(active_state->connection_out, (struct sockaddr *)&to,
293: &tolen) < 0)
1.19 markus 294: return 0;
295: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
296: return 0;
297: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
298: return 0;
299: return 1;
300: }
301:
1.92 markus 302: /*
1.91 markus 303: * Exports an IV from the CipherContext required to export the key
304: * state back from the unprivileged child to the privileged parent
305: * process.
306: */
307:
308: void
309: packet_get_keyiv(int mode, u_char *iv, u_int len)
310: {
311: CipherContext *cc;
312:
313: if (mode == MODE_OUT)
1.161 andreas 314: cc = &active_state->send_context;
1.91 markus 315: else
1.161 andreas 316: cc = &active_state->receive_context;
1.91 markus 317:
318: cipher_get_keyiv(cc, iv, len);
319: }
320:
321: int
322: packet_get_keycontext(int mode, u_char *dat)
323: {
324: CipherContext *cc;
1.92 markus 325:
1.91 markus 326: if (mode == MODE_OUT)
1.161 andreas 327: cc = &active_state->send_context;
1.91 markus 328: else
1.161 andreas 329: cc = &active_state->receive_context;
1.91 markus 330:
331: return (cipher_get_keycontext(cc, dat));
332: }
333:
334: void
335: packet_set_keycontext(int mode, u_char *dat)
336: {
337: CipherContext *cc;
1.92 markus 338:
1.91 markus 339: if (mode == MODE_OUT)
1.161 andreas 340: cc = &active_state->send_context;
1.91 markus 341: else
1.161 andreas 342: cc = &active_state->receive_context;
1.91 markus 343:
344: cipher_set_keycontext(cc, dat);
345: }
346:
347: int
348: packet_get_keyiv_len(int mode)
349: {
350: CipherContext *cc;
351:
352: if (mode == MODE_OUT)
1.161 andreas 353: cc = &active_state->send_context;
1.91 markus 354: else
1.161 andreas 355: cc = &active_state->receive_context;
1.91 markus 356:
357: return (cipher_get_keyiv_len(cc));
358: }
1.125 deraadt 359:
1.91 markus 360: void
361: packet_set_iv(int mode, u_char *dat)
362: {
363: CipherContext *cc;
364:
365: if (mode == MODE_OUT)
1.161 andreas 366: cc = &active_state->send_context;
1.91 markus 367: else
1.161 andreas 368: cc = &active_state->receive_context;
1.91 markus 369:
370: cipher_set_keyiv(cc, dat);
371: }
1.125 deraadt 372:
1.91 markus 373: int
1.107 deraadt 374: packet_get_ssh1_cipher(void)
1.91 markus 375: {
1.161 andreas 376: return (cipher_get_number(active_state->receive_context.cipher));
1.91 markus 377: }
378:
1.105 markus 379: void
1.157 markus 380: packet_get_state(int mode, u_int32_t *seqnr, u_int64_t *blocks, u_int32_t *packets,
381: u_int64_t *bytes)
1.105 markus 382: {
383: struct packet_state *state;
1.104 markus 384:
1.161 andreas 385: state = (mode == MODE_IN) ?
386: &active_state->p_read : &active_state->p_send;
1.157 markus 387: if (seqnr)
388: *seqnr = state->seqnr;
389: if (blocks)
390: *blocks = state->blocks;
391: if (packets)
392: *packets = state->packets;
393: if (bytes)
394: *bytes = state->bytes;
1.91 markus 395: }
396:
397: void
1.157 markus 398: packet_set_state(int mode, u_int32_t seqnr, u_int64_t blocks, u_int32_t packets,
399: u_int64_t bytes)
1.91 markus 400: {
1.105 markus 401: struct packet_state *state;
402:
1.161 andreas 403: state = (mode == MODE_IN) ?
404: &active_state->p_read : &active_state->p_send;
1.105 markus 405: state->seqnr = seqnr;
406: state->blocks = blocks;
407: state->packets = packets;
1.157 markus 408: state->bytes = bytes;
1.91 markus 409: }
410:
1.19 markus 411: /* returns 1 if connection is via ipv4 */
412:
413: int
1.73 itojun 414: packet_connection_is_ipv4(void)
1.19 markus 415: {
416: struct sockaddr_storage to;
1.21 deraadt 417: socklen_t tolen = sizeof(to);
1.19 markus 418:
419: memset(&to, 0, sizeof(to));
1.161 andreas 420: if (getsockname(active_state->connection_out, (struct sockaddr *)&to,
421: &tolen) < 0)
1.19 markus 422: return 0;
423: if (to.ss_family != AF_INET)
424: return 0;
425: return 1;
426: }
427:
1.1 deraadt 428: /* Sets the connection into non-blocking mode. */
429:
1.2 provos 430: void
1.73 itojun 431: packet_set_nonblocking(void)
1.1 deraadt 432: {
1.14 markus 433: /* Set the socket into non-blocking mode. */
1.161 andreas 434: set_nonblock(active_state->connection_in);
1.14 markus 435:
1.161 andreas 436: if (active_state->connection_out != active_state->connection_in)
437: set_nonblock(active_state->connection_out);
1.1 deraadt 438: }
439:
440: /* Returns the socket used for reading. */
441:
1.2 provos 442: int
1.73 itojun 443: packet_get_connection_in(void)
1.1 deraadt 444: {
1.161 andreas 445: return active_state->connection_in;
1.1 deraadt 446: }
447:
448: /* Returns the descriptor used for writing. */
449:
1.2 provos 450: int
1.73 itojun 451: packet_get_connection_out(void)
1.1 deraadt 452: {
1.161 andreas 453: return active_state->connection_out;
1.1 deraadt 454: }
455:
456: /* Closes the connection and clears and frees internal data structures. */
457:
1.2 provos 458: void
1.73 itojun 459: packet_close(void)
1.1 deraadt 460: {
1.161 andreas 461: if (!active_state->initialized)
1.14 markus 462: return;
1.161 andreas 463: active_state->initialized = 0;
464: if (active_state->connection_in == active_state->connection_out) {
465: shutdown(active_state->connection_out, SHUT_RDWR);
466: close(active_state->connection_out);
1.14 markus 467: } else {
1.161 andreas 468: close(active_state->connection_in);
469: close(active_state->connection_out);
1.14 markus 470: }
1.161 andreas 471: buffer_free(&active_state->input);
472: buffer_free(&active_state->output);
473: buffer_free(&active_state->outgoing_packet);
474: buffer_free(&active_state->incoming_packet);
475: if (active_state->compression_buffer_ready) {
476: buffer_free(&active_state->compression_buffer);
1.14 markus 477: buffer_compress_uninit();
478: }
1.161 andreas 479: cipher_cleanup(&active_state->send_context);
480: cipher_cleanup(&active_state->receive_context);
1.1 deraadt 481: }
482:
483: /* Sets remote side protocol flags. */
484:
1.2 provos 485: void
1.40 markus 486: packet_set_protocol_flags(u_int protocol_flags)
1.1 deraadt 487: {
1.161 andreas 488: active_state->remote_protocol_flags = protocol_flags;
1.1 deraadt 489: }
490:
491: /* Returns the remote protocol flags set earlier by the above function. */
492:
1.40 markus 493: u_int
1.73 itojun 494: packet_get_protocol_flags(void)
1.1 deraadt 495: {
1.161 andreas 496: return active_state->remote_protocol_flags;
1.1 deraadt 497: }
498:
1.16 markus 499: /*
500: * Starts packet compression from the next packet on in both directions.
501: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
502: */
1.1 deraadt 503:
1.68 itojun 504: static void
505: packet_init_compression(void)
1.60 markus 506: {
1.161 andreas 507: if (active_state->compression_buffer_ready == 1)
1.60 markus 508: return;
1.161 andreas 509: active_state->compression_buffer_ready = 1;
510: buffer_init(&active_state->compression_buffer);
1.60 markus 511: }
512:
1.2 provos 513: void
514: packet_start_compression(int level)
1.1 deraadt 515: {
1.161 andreas 516: if (active_state->packet_compression && !compat20)
1.14 markus 517: fatal("Compression already enabled.");
1.161 andreas 518: active_state->packet_compression = 1;
1.60 markus 519: packet_init_compression();
520: buffer_compress_init_send(level);
521: buffer_compress_init_recv();
1.1 deraadt 522: }
523:
1.16 markus 524: /*
525: * Causes any further packets to be encrypted using the given key. The same
526: * key is used for both sending and reception. However, both directions are
527: * encrypted independently of each other.
528: */
1.95 markus 529:
1.2 provos 530: void
1.40 markus 531: packet_set_encryption_key(const u_char *key, u_int keylen,
1.37 markus 532: int number)
1.1 deraadt 533: {
1.37 markus 534: Cipher *cipher = cipher_by_number(number);
1.97 deraadt 535:
1.37 markus 536: if (cipher == NULL)
537: fatal("packet_set_encryption_key: unknown cipher number %d", number);
1.25 markus 538: if (keylen < 20)
1.37 markus 539: fatal("packet_set_encryption_key: keylen too small: %d", keylen);
1.95 markus 540: if (keylen > SSH_SESSION_KEY_LENGTH)
541: fatal("packet_set_encryption_key: keylen too big: %d", keylen);
1.161 andreas 542: memcpy(active_state->ssh1_key, key, keylen);
543: active_state->ssh1_keylen = keylen;
544: cipher_init(&active_state->send_context, cipher, key, keylen, NULL,
545: 0, CIPHER_ENCRYPT);
546: cipher_init(&active_state->receive_context, cipher, key, keylen, NULL,
547: 0, CIPHER_DECRYPT);
1.95 markus 548: }
549:
550: u_int
551: packet_get_encryption_key(u_char *key)
552: {
553: if (key == NULL)
1.161 andreas 554: return (active_state->ssh1_keylen);
555: memcpy(key, active_state->ssh1_key, active_state->ssh1_keylen);
556: return (active_state->ssh1_keylen);
1.1 deraadt 557: }
558:
1.62 markus 559: /* Start constructing a packet to send. */
1.2 provos 560: void
1.62 markus 561: packet_start(u_char type)
1.1 deraadt 562: {
1.62 markus 563: u_char buf[9];
564: int len;
1.1 deraadt 565:
1.62 markus 566: DBG(debug("packet_start[%d]", type));
567: len = compat20 ? 6 : 9;
568: memset(buf, 0, len - 1);
569: buf[len - 1] = type;
1.161 andreas 570: buffer_clear(&active_state->outgoing_packet);
571: buffer_append(&active_state->outgoing_packet, buf, len);
1.25 markus 572: }
573:
1.62 markus 574: /* Append payload. */
1.2 provos 575: void
576: packet_put_char(int value)
1.1 deraadt 577: {
1.14 markus 578: char ch = value;
1.97 deraadt 579:
1.161 andreas 580: buffer_append(&active_state->outgoing_packet, &ch, 1);
1.1 deraadt 581: }
1.125 deraadt 582:
1.2 provos 583: void
1.40 markus 584: packet_put_int(u_int value)
1.1 deraadt 585: {
1.161 andreas 586: buffer_put_int(&active_state->outgoing_packet, value);
1.1 deraadt 587: }
1.125 deraadt 588:
1.2 provos 589: void
1.162 ! andreas 590: packet_put_int64(u_int64_t value)
! 591: {
! 592: buffer_put_int64(&active_state->outgoing_packet, value);
! 593: }
! 594:
! 595: void
1.76 stevesk 596: packet_put_string(const void *buf, u_int len)
1.1 deraadt 597: {
1.161 andreas 598: buffer_put_string(&active_state->outgoing_packet, buf, len);
1.1 deraadt 599: }
1.125 deraadt 600:
1.24 markus 601: void
602: packet_put_cstring(const char *str)
603: {
1.161 andreas 604: buffer_put_cstring(&active_state->outgoing_packet, str);
1.24 markus 605: }
1.125 deraadt 606:
1.24 markus 607: void
1.76 stevesk 608: packet_put_raw(const void *buf, u_int len)
1.24 markus 609: {
1.161 andreas 610: buffer_append(&active_state->outgoing_packet, buf, len);
1.24 markus 611: }
1.125 deraadt 612:
1.2 provos 613: void
1.14 markus 614: packet_put_bignum(BIGNUM * value)
1.1 deraadt 615: {
1.161 andreas 616: buffer_put_bignum(&active_state->outgoing_packet, value);
1.1 deraadt 617: }
1.125 deraadt 618:
1.24 markus 619: void
620: packet_put_bignum2(BIGNUM * value)
621: {
1.161 andreas 622: buffer_put_bignum2(&active_state->outgoing_packet, value);
1.24 markus 623: }
1.1 deraadt 624:
1.16 markus 625: /*
626: * Finalizes and sends the packet. If the encryption key has been set,
627: * encrypts the packet before sending.
628: */
1.14 markus 629:
1.68 itojun 630: static void
1.49 itojun 631: packet_send1(void)
1.1 deraadt 632: {
1.89 markus 633: u_char buf[8], *cp;
1.14 markus 634: int i, padding, len;
1.40 markus 635: u_int checksum;
1.115 avsm 636: u_int32_t rnd = 0;
1.14 markus 637:
1.16 markus 638: /*
639: * If using packet compression, compress the payload of the outgoing
640: * packet.
641: */
1.161 andreas 642: if (active_state->packet_compression) {
643: buffer_clear(&active_state->compression_buffer);
1.14 markus 644: /* Skip padding. */
1.161 andreas 645: buffer_consume(&active_state->outgoing_packet, 8);
1.14 markus 646: /* padding */
1.161 andreas 647: buffer_append(&active_state->compression_buffer,
648: "\0\0\0\0\0\0\0\0", 8);
649: buffer_compress(&active_state->outgoing_packet,
650: &active_state->compression_buffer);
651: buffer_clear(&active_state->outgoing_packet);
652: buffer_append(&active_state->outgoing_packet,
653: buffer_ptr(&active_state->compression_buffer),
654: buffer_len(&active_state->compression_buffer));
1.14 markus 655: }
656: /* Compute packet length without padding (add checksum, remove padding). */
1.161 andreas 657: len = buffer_len(&active_state->outgoing_packet) + 4 - 8;
1.14 markus 658:
1.32 markus 659: /* Insert padding. Initialized to zero in packet_start1() */
1.14 markus 660: padding = 8 - len % 8;
1.161 andreas 661: if (!active_state->send_context.plaintext) {
662: cp = buffer_ptr(&active_state->outgoing_packet);
1.14 markus 663: for (i = 0; i < padding; i++) {
664: if (i % 4 == 0)
1.115 avsm 665: rnd = arc4random();
666: cp[7 - i] = rnd & 0xff;
667: rnd >>= 8;
1.14 markus 668: }
669: }
1.161 andreas 670: buffer_consume(&active_state->outgoing_packet, 8 - padding);
1.14 markus 671:
672: /* Add check bytes. */
1.161 andreas 673: checksum = ssh_crc32(buffer_ptr(&active_state->outgoing_packet),
674: buffer_len(&active_state->outgoing_packet));
1.131 djm 675: put_u32(buf, checksum);
1.161 andreas 676: buffer_append(&active_state->outgoing_packet, buf, 4);
1.1 deraadt 677:
678: #ifdef PACKET_DEBUG
1.14 markus 679: fprintf(stderr, "packet_send plain: ");
1.161 andreas 680: buffer_dump(&active_state->outgoing_packet);
1.1 deraadt 681: #endif
682:
1.14 markus 683: /* Append to output. */
1.131 djm 684: put_u32(buf, len);
1.161 andreas 685: buffer_append(&active_state->output, buf, 4);
686: cp = buffer_append_space(&active_state->output,
687: buffer_len(&active_state->outgoing_packet));
688: cipher_crypt(&active_state->send_context, cp,
689: buffer_ptr(&active_state->outgoing_packet),
690: buffer_len(&active_state->outgoing_packet));
1.14 markus 691:
1.1 deraadt 692: #ifdef PACKET_DEBUG
1.14 markus 693: fprintf(stderr, "encrypted: ");
1.161 andreas 694: buffer_dump(&active_state->output);
1.1 deraadt 695: #endif
1.161 andreas 696: active_state->p_send.packets++;
697: active_state->p_send.bytes += len +
698: buffer_len(&active_state->outgoing_packet);
699: buffer_clear(&active_state->outgoing_packet);
1.1 deraadt 700:
1.16 markus 701: /*
1.120 djm 702: * Note that the packet is now only buffered in output. It won't be
1.16 markus 703: * actually sent until packet_write_wait or packet_write_poll is
704: * called.
705: */
1.1 deraadt 706: }
707:
1.91 markus 708: void
1.57 markus 709: set_newkeys(int mode)
710: {
711: Enc *enc;
712: Mac *mac;
713: Comp *comp;
714: CipherContext *cc;
1.105 markus 715: u_int64_t *max_blocks;
1.115 avsm 716: int crypt_type;
1.57 markus 717:
1.100 markus 718: debug2("set_newkeys: mode %d", mode);
1.57 markus 719:
1.88 markus 720: if (mode == MODE_OUT) {
1.161 andreas 721: cc = &active_state->send_context;
1.115 avsm 722: crypt_type = CIPHER_ENCRYPT;
1.161 andreas 723: active_state->p_send.packets = active_state->p_send.blocks = 0;
724: max_blocks = &active_state->max_blocks_out;
1.88 markus 725: } else {
1.161 andreas 726: cc = &active_state->receive_context;
1.115 avsm 727: crypt_type = CIPHER_DECRYPT;
1.161 andreas 728: active_state->p_read.packets = active_state->p_read.blocks = 0;
729: max_blocks = &active_state->max_blocks_in;
1.88 markus 730: }
1.161 andreas 731: if (active_state->newkeys[mode] != NULL) {
1.100 markus 732: debug("set_newkeys: rekeying");
1.88 markus 733: cipher_cleanup(cc);
1.161 andreas 734: enc = &active_state->newkeys[mode]->enc;
735: mac = &active_state->newkeys[mode]->mac;
736: comp = &active_state->newkeys[mode]->comp;
1.148 pvalchev 737: mac_clear(mac);
1.59 markus 738: xfree(enc->name);
739: xfree(enc->iv);
740: xfree(enc->key);
741: xfree(mac->name);
742: xfree(mac->key);
743: xfree(comp->name);
1.161 andreas 744: xfree(active_state->newkeys[mode]);
1.57 markus 745: }
1.161 andreas 746: active_state->newkeys[mode] = kex_get_newkeys(mode);
747: if (active_state->newkeys[mode] == NULL)
1.57 markus 748: fatal("newkeys: no keys for mode %d", mode);
1.161 andreas 749: enc = &active_state->newkeys[mode]->enc;
750: mac = &active_state->newkeys[mode]->mac;
751: comp = &active_state->newkeys[mode]->comp;
1.148 pvalchev 752: if (mac_init(mac) == 0)
1.57 markus 753: mac->enabled = 1;
754: DBG(debug("cipher_init_context: %d", mode));
1.88 markus 755: cipher_init(cc, enc->cipher, enc->key, enc->key_len,
1.115 avsm 756: enc->iv, enc->block_size, crypt_type);
1.91 markus 757: /* Deleting the keys does not gain extra security */
758: /* memset(enc->iv, 0, enc->block_size);
1.147 djm 759: memset(enc->key, 0, enc->key_len);
760: memset(mac->key, 0, mac->key_len); */
1.118 markus 761: if ((comp->type == COMP_ZLIB ||
1.161 andreas 762: (comp->type == COMP_DELAYED &&
763: active_state->after_authentication)) && comp->enabled == 0) {
1.60 markus 764: packet_init_compression();
765: if (mode == MODE_OUT)
766: buffer_compress_init_send(6);
767: else
768: buffer_compress_init_recv();
1.57 markus 769: comp->enabled = 1;
770: }
1.109 markus 771: /*
772: * The 2^(blocksize*2) limit is too expensive for 3DES,
773: * blowfish, etc, so enforce a 1GB limit for small blocksizes.
774: */
775: if (enc->block_size >= 16)
776: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
777: else
778: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.161 andreas 779: if (active_state->rekey_limit)
780: *max_blocks = MIN(*max_blocks,
781: active_state->rekey_limit / enc->block_size);
1.57 markus 782: }
783:
1.16 markus 784: /*
1.118 markus 785: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 786: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 787: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
788: */
789: static void
790: packet_enable_delayed_compress(void)
791: {
792: Comp *comp = NULL;
793: int mode;
794:
795: /*
796: * Remember that we are past the authentication step, so rekeying
797: * with COMP_DELAYED will turn on compression immediately.
798: */
1.161 andreas 799: active_state->after_authentication = 1;
1.118 markus 800: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 801: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.161 andreas 802: if (active_state->newkeys[mode] == NULL)
1.145 markus 803: continue;
1.161 andreas 804: comp = &active_state->newkeys[mode]->comp;
1.118 markus 805: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.119 markus 806: packet_init_compression();
1.118 markus 807: if (mode == MODE_OUT)
808: buffer_compress_init_send(6);
809: else
810: buffer_compress_init_recv();
811: comp->enabled = 1;
812: }
813: }
814: }
815:
816: /*
1.25 markus 817: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
818: */
1.68 itojun 819: static void
1.105 markus 820: packet_send2_wrapped(void)
1.25 markus 821: {
1.89 markus 822: u_char type, *cp, *macbuf = NULL;
1.71 markus 823: u_char padlen, pad;
1.40 markus 824: u_int packet_length = 0;
1.71 markus 825: u_int i, len;
1.115 avsm 826: u_int32_t rnd = 0;
1.25 markus 827: Enc *enc = NULL;
828: Mac *mac = NULL;
829: Comp *comp = NULL;
830: int block_size;
831:
1.161 andreas 832: if (active_state->newkeys[MODE_OUT] != NULL) {
833: enc = &active_state->newkeys[MODE_OUT]->enc;
834: mac = &active_state->newkeys[MODE_OUT]->mac;
835: comp = &active_state->newkeys[MODE_OUT]->comp;
1.25 markus 836: }
1.88 markus 837: block_size = enc ? enc->block_size : 8;
1.25 markus 838:
1.161 andreas 839: cp = buffer_ptr(&active_state->outgoing_packet);
1.89 markus 840: type = cp[5];
1.25 markus 841:
842: #ifdef PACKET_DEBUG
843: fprintf(stderr, "plain: ");
1.161 andreas 844: buffer_dump(&active_state->outgoing_packet);
1.25 markus 845: #endif
846:
847: if (comp && comp->enabled) {
1.161 andreas 848: len = buffer_len(&active_state->outgoing_packet);
1.25 markus 849: /* skip header, compress only payload */
1.161 andreas 850: buffer_consume(&active_state->outgoing_packet, 5);
851: buffer_clear(&active_state->compression_buffer);
852: buffer_compress(&active_state->outgoing_packet,
853: &active_state->compression_buffer);
854: buffer_clear(&active_state->outgoing_packet);
855: buffer_append(&active_state->outgoing_packet, "\0\0\0\0\0", 5);
856: buffer_append(&active_state->outgoing_packet,
857: buffer_ptr(&active_state->compression_buffer),
858: buffer_len(&active_state->compression_buffer));
1.25 markus 859: DBG(debug("compression: raw %d compressed %d", len,
1.161 andreas 860: buffer_len(&active_state->outgoing_packet)));
1.25 markus 861: }
862:
863: /* sizeof (packet_len + pad_len + payload) */
1.161 andreas 864: len = buffer_len(&active_state->outgoing_packet);
1.25 markus 865:
866: /*
867: * calc size of padding, alloc space, get random data,
868: * minimum padding is 4 bytes
869: */
870: padlen = block_size - (len % block_size);
871: if (padlen < 4)
872: padlen += block_size;
1.161 andreas 873: if (active_state->extra_pad) {
1.71 markus 874: /* will wrap if extra_pad+padlen > 255 */
1.161 andreas 875: active_state->extra_pad =
876: roundup(active_state->extra_pad, block_size);
877: pad = active_state->extra_pad -
878: ((len + padlen) % active_state->extra_pad);
1.93 markus 879: debug3("packet_send2: adding %d (len %d padlen %d extra_pad %d)",
1.161 andreas 880: pad, len, padlen, active_state->extra_pad);
1.71 markus 881: padlen += pad;
1.161 andreas 882: active_state->extra_pad = 0;
1.71 markus 883: }
1.161 andreas 884: cp = buffer_append_space(&active_state->outgoing_packet, padlen);
885: if (enc && !active_state->send_context.plaintext) {
1.32 markus 886: /* random padding */
1.25 markus 887: for (i = 0; i < padlen; i++) {
888: if (i % 4 == 0)
1.115 avsm 889: rnd = arc4random();
890: cp[i] = rnd & 0xff;
891: rnd >>= 8;
1.25 markus 892: }
1.32 markus 893: } else {
894: /* clear padding */
895: memset(cp, 0, padlen);
1.25 markus 896: }
897: /* packet_length includes payload, padding and padding length field */
1.161 andreas 898: packet_length = buffer_len(&active_state->outgoing_packet) - 4;
899: cp = buffer_ptr(&active_state->outgoing_packet);
1.131 djm 900: put_u32(cp, packet_length);
1.89 markus 901: cp[4] = padlen;
1.25 markus 902: DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen));
903:
904: /* compute MAC over seqnr and packet(length fields, payload, padding) */
905: if (mac && mac->enabled) {
1.161 andreas 906: macbuf = mac_compute(mac, active_state->p_send.seqnr,
907: buffer_ptr(&active_state->outgoing_packet),
908: buffer_len(&active_state->outgoing_packet));
909: DBG(debug("done calc MAC out #%d", active_state->p_send.seqnr));
1.25 markus 910: }
911: /* encrypt packet and append to output buffer. */
1.161 andreas 912: cp = buffer_append_space(&active_state->output,
913: buffer_len(&active_state->outgoing_packet));
914: cipher_crypt(&active_state->send_context, cp,
915: buffer_ptr(&active_state->outgoing_packet),
916: buffer_len(&active_state->outgoing_packet));
1.25 markus 917: /* append unencrypted MAC */
918: if (mac && mac->enabled)
1.161 andreas 919: buffer_append(&active_state->output, macbuf, mac->mac_len);
1.25 markus 920: #ifdef PACKET_DEBUG
921: fprintf(stderr, "encrypted: ");
1.161 andreas 922: buffer_dump(&active_state->output);
1.25 markus 923: #endif
1.29 markus 924: /* increment sequence number for outgoing packets */
1.161 andreas 925: if (++active_state->p_send.seqnr == 0)
1.106 itojun 926: logit("outgoing seqnr wraps around");
1.161 andreas 927: if (++active_state->p_send.packets == 0)
1.105 markus 928: if (!(datafellows & SSH_BUG_NOREKEY))
929: fatal("XXX too many packets with same key");
1.161 andreas 930: active_state->p_send.blocks += (packet_length + 4) / block_size;
931: active_state->p_send.bytes += packet_length + 4;
932: buffer_clear(&active_state->outgoing_packet);
1.25 markus 933:
1.57 markus 934: if (type == SSH2_MSG_NEWKEYS)
935: set_newkeys(MODE_OUT);
1.161 andreas 936: else if (type == SSH2_MSG_USERAUTH_SUCCESS && active_state->server_side)
1.118 markus 937: packet_enable_delayed_compress();
1.25 markus 938: }
939:
1.105 markus 940: static void
941: packet_send2(void)
942: {
943: static int rekeying = 0;
944: struct packet *p;
945: u_char type, *cp;
946:
1.161 andreas 947: cp = buffer_ptr(&active_state->outgoing_packet);
1.105 markus 948: type = cp[5];
949:
950: /* during rekeying we can only send key exchange messages */
951: if (rekeying) {
952: if (!((type >= SSH2_MSG_TRANSPORT_MIN) &&
953: (type <= SSH2_MSG_TRANSPORT_MAX))) {
954: debug("enqueue packet: %u", type);
955: p = xmalloc(sizeof(*p));
956: p->type = type;
1.161 andreas 957: memcpy(&p->payload, &active_state->outgoing_packet,
958: sizeof(Buffer));
959: buffer_init(&active_state->outgoing_packet);
960: TAILQ_INSERT_TAIL(&active_state->outgoing, p, next);
1.105 markus 961: return;
962: }
963: }
964:
965: /* rekeying starts with sending KEXINIT */
966: if (type == SSH2_MSG_KEXINIT)
967: rekeying = 1;
968:
969: packet_send2_wrapped();
970:
971: /* after a NEWKEYS message we can send the complete queue */
972: if (type == SSH2_MSG_NEWKEYS) {
973: rekeying = 0;
1.161 andreas 974: while ((p = TAILQ_FIRST(&active_state->outgoing))) {
1.105 markus 975: type = p->type;
976: debug("dequeue packet: %u", type);
1.161 andreas 977: buffer_free(&active_state->outgoing_packet);
978: memcpy(&active_state->outgoing_packet, &p->payload,
1.105 markus 979: sizeof(Buffer));
1.161 andreas 980: TAILQ_REMOVE(&active_state->outgoing, p, next);
1.105 markus 981: xfree(p);
982: packet_send2_wrapped();
983: }
984: }
985: }
986:
1.25 markus 987: void
1.73 itojun 988: packet_send(void)
1.25 markus 989: {
1.62 markus 990: if (compat20)
1.25 markus 991: packet_send2();
992: else
993: packet_send1();
994: DBG(debug("packet_send done"));
995: }
996:
997: /*
1.16 markus 998: * Waits until a packet has been received, and returns its type. Note that
999: * no other data is processed until this returns, so this function should not
1000: * be used during the interactive session.
1001: */
1.1 deraadt 1002:
1.2 provos 1003: int
1.82 markus 1004: packet_read_seqnr(u_int32_t *seqnr_p)
1.1 deraadt 1005: {
1.154 dtucker 1006: int type, len, ret, ms_remain;
1.56 millert 1007: fd_set *setp;
1.14 markus 1008: char buf[8192];
1.155 deraadt 1009: struct timeval timeout, start, *timeoutp = NULL;
1010:
1.25 markus 1011: DBG(debug("packet_read()"));
1.14 markus 1012:
1.161 andreas 1013: setp = (fd_set *)xcalloc(howmany(active_state->connection_in + 1,
1014: NFDBITS), sizeof(fd_mask));
1.56 millert 1015:
1.14 markus 1016: /* Since we are blocking, ensure that all written packets have been sent. */
1017: packet_write_wait();
1018:
1019: /* Stay in the loop until we have received a complete packet. */
1020: for (;;) {
1021: /* Try to read a packet from the buffer. */
1.82 markus 1022: type = packet_read_poll_seqnr(seqnr_p);
1.62 markus 1023: if (!compat20 && (
1.32 markus 1024: type == SSH_SMSG_SUCCESS
1.14 markus 1025: || type == SSH_SMSG_FAILURE
1026: || type == SSH_CMSG_EOF
1.32 markus 1027: || type == SSH_CMSG_EXIT_CONFIRMATION))
1.79 markus 1028: packet_check_eom();
1.14 markus 1029: /* If we got a packet, return it. */
1.56 millert 1030: if (type != SSH_MSG_NONE) {
1031: xfree(setp);
1.14 markus 1032: return type;
1.56 millert 1033: }
1.16 markus 1034: /*
1035: * Otherwise, wait for some data to arrive, add it to the
1036: * buffer, and try again.
1037: */
1.161 andreas 1038: memset(setp, 0, howmany(active_state->connection_in + 1,
1039: NFDBITS) * sizeof(fd_mask));
1040: FD_SET(active_state->connection_in, setp);
1.16 markus 1041:
1.161 andreas 1042: if (active_state->packet_timeout_ms > 0) {
1043: ms_remain = active_state->packet_timeout_ms;
1.154 dtucker 1044: timeoutp = &timeout;
1045: }
1.14 markus 1046: /* Wait for some data to arrive. */
1.154 dtucker 1047: for (;;) {
1.161 andreas 1048: if (active_state->packet_timeout_ms != -1) {
1.154 dtucker 1049: ms_to_timeval(&timeout, ms_remain);
1050: gettimeofday(&start, NULL);
1051: }
1.161 andreas 1052: if ((ret = select(active_state->connection_in + 1, setp,
1053: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1054: break;
1.161 andreas 1055: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1056: break;
1.161 andreas 1057: if (active_state->packet_timeout_ms == -1)
1.154 dtucker 1058: continue;
1059: ms_subtract_diff(&start, &ms_remain);
1060: if (ms_remain <= 0) {
1061: ret = 0;
1062: break;
1063: }
1064: }
1065: if (ret == 0) {
1066: logit("Connection to %.200s timed out while "
1067: "waiting to read", get_remote_ipaddr());
1068: cleanup_exit(255);
1069: }
1.14 markus 1070: /* Read data from the socket. */
1.161 andreas 1071: len = read(active_state->connection_in, buf, sizeof(buf));
1.18 markus 1072: if (len == 0) {
1.106 itojun 1073: logit("Connection closed by %.200s", get_remote_ipaddr());
1.112 markus 1074: cleanup_exit(255);
1.18 markus 1075: }
1.14 markus 1076: if (len < 0)
1077: fatal("Read from socket failed: %.100s", strerror(errno));
1078: /* Append it to the buffer. */
1079: packet_process_incoming(buf, len);
1080: }
1081: /* NOTREACHED */
1.1 deraadt 1082: }
1083:
1.77 djm 1084: int
1.82 markus 1085: packet_read(void)
1.77 djm 1086: {
1.82 markus 1087: return packet_read_seqnr(NULL);
1.77 djm 1088: }
1089:
1.16 markus 1090: /*
1091: * Waits until a packet has been received, verifies that its type matches
1092: * that given, and gives a fatal error and exits if there is a mismatch.
1093: */
1.1 deraadt 1094:
1.2 provos 1095: void
1.82 markus 1096: packet_read_expect(int expected_type)
1.1 deraadt 1097: {
1.14 markus 1098: int type;
1.1 deraadt 1099:
1.82 markus 1100: type = packet_read();
1.14 markus 1101: if (type != expected_type)
1102: packet_disconnect("Protocol error: expected packet type %d, got %d",
1.25 markus 1103: expected_type, type);
1.1 deraadt 1104: }
1105:
1106: /* Checks if a full packet is available in the data received so far via
1.14 markus 1107: * packet_process_incoming. If so, reads the packet; otherwise returns
1108: * SSH_MSG_NONE. This does not wait for data from the connection.
1109: *
1.150 dtucker 1110: * SSH_MSG_DISCONNECT is handled specially here. Also,
1111: * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1112: * to higher levels.
1.14 markus 1113: */
1.1 deraadt 1114:
1.68 itojun 1115: static int
1.82 markus 1116: packet_read_poll1(void)
1.1 deraadt 1117: {
1.40 markus 1118: u_int len, padded_len;
1.89 markus 1119: u_char *cp, type;
1.40 markus 1120: u_int checksum, stored_checksum;
1.14 markus 1121:
1122: /* Check if input size is less than minimum packet size. */
1.161 andreas 1123: if (buffer_len(&active_state->input) < 4 + 8)
1.14 markus 1124: return SSH_MSG_NONE;
1125: /* Get length of incoming packet. */
1.161 andreas 1126: cp = buffer_ptr(&active_state->input);
1.131 djm 1127: len = get_u32(cp);
1.14 markus 1128: if (len < 1 + 2 + 2 || len > 256 * 1024)
1.98 markus 1129: packet_disconnect("Bad packet length %u.", len);
1.14 markus 1130: padded_len = (len + 8) & ~7;
1131:
1132: /* Check if the packet has been entirely received. */
1.161 andreas 1133: if (buffer_len(&active_state->input) < 4 + padded_len)
1.14 markus 1134: return SSH_MSG_NONE;
1135:
1136: /* The entire packet is in buffer. */
1137:
1138: /* Consume packet length. */
1.161 andreas 1139: buffer_consume(&active_state->input, 4);
1.14 markus 1140:
1.62 markus 1141: /*
1142: * Cryptographic attack detector for ssh
1143: * (C)1998 CORE-SDI, Buenos Aires Argentina
1144: * Ariel Futoransky(futo@core-sdi.com)
1145: */
1.161 andreas 1146: if (!active_state->receive_context.plaintext) {
1147: switch (detect_attack(buffer_ptr(&active_state->input),
1148: padded_len)) {
1.144 djm 1149: case DEATTACK_DETECTED:
1150: packet_disconnect("crc32 compensation attack: "
1151: "network attack detected");
1152: case DEATTACK_DOS_DETECTED:
1153: packet_disconnect("deattack denial of "
1154: "service detected");
1155: }
1156: }
1.62 markus 1157:
1158: /* Decrypt data to incoming_packet. */
1.161 andreas 1159: buffer_clear(&active_state->incoming_packet);
1160: cp = buffer_append_space(&active_state->incoming_packet, padded_len);
1161: cipher_crypt(&active_state->receive_context, cp,
1162: buffer_ptr(&active_state->input), padded_len);
1.62 markus 1163:
1.161 andreas 1164: buffer_consume(&active_state->input, padded_len);
1.1 deraadt 1165:
1166: #ifdef PACKET_DEBUG
1.14 markus 1167: fprintf(stderr, "read_poll plain: ");
1.161 andreas 1168: buffer_dump(&active_state->incoming_packet);
1.1 deraadt 1169: #endif
1170:
1.14 markus 1171: /* Compute packet checksum. */
1.161 andreas 1172: checksum = ssh_crc32(buffer_ptr(&active_state->incoming_packet),
1173: buffer_len(&active_state->incoming_packet) - 4);
1.14 markus 1174:
1175: /* Skip padding. */
1.161 andreas 1176: buffer_consume(&active_state->incoming_packet, 8 - len % 8);
1.14 markus 1177:
1178: /* Test check bytes. */
1.161 andreas 1179: if (len != buffer_len(&active_state->incoming_packet))
1.77 djm 1180: packet_disconnect("packet_read_poll1: len %d != buffer_len %d.",
1.161 andreas 1181: len, buffer_len(&active_state->incoming_packet));
1.14 markus 1182:
1.161 andreas 1183: cp = (u_char *)buffer_ptr(&active_state->incoming_packet) + len - 4;
1.131 djm 1184: stored_checksum = get_u32(cp);
1.14 markus 1185: if (checksum != stored_checksum)
1186: packet_disconnect("Corrupted check bytes on input.");
1.161 andreas 1187: buffer_consume_end(&active_state->incoming_packet, 4);
1.14 markus 1188:
1.161 andreas 1189: if (active_state->packet_compression) {
1190: buffer_clear(&active_state->compression_buffer);
1191: buffer_uncompress(&active_state->incoming_packet,
1192: &active_state->compression_buffer);
1193: buffer_clear(&active_state->incoming_packet);
1194: buffer_append(&active_state->incoming_packet,
1195: buffer_ptr(&active_state->compression_buffer),
1196: buffer_len(&active_state->compression_buffer));
1197: }
1198: active_state->p_read.packets++;
1199: active_state->p_read.bytes += padded_len + 4;
1200: type = buffer_get_char(&active_state->incoming_packet);
1.116 markus 1201: if (type < SSH_MSG_MIN || type > SSH_MSG_MAX)
1202: packet_disconnect("Invalid ssh1 packet type: %d", type);
1.62 markus 1203: return type;
1.1 deraadt 1204: }
1.14 markus 1205:
1.68 itojun 1206: static int
1.82 markus 1207: packet_read_poll2(u_int32_t *seqnr_p)
1.25 markus 1208: {
1.40 markus 1209: u_int padlen, need;
1.89 markus 1210: u_char *macbuf, *cp, type;
1.117 djm 1211: u_int maclen, block_size;
1.25 markus 1212: Enc *enc = NULL;
1213: Mac *mac = NULL;
1214: Comp *comp = NULL;
1215:
1.161 andreas 1216: if (active_state->packet_discard)
1.159 markus 1217: return SSH_MSG_NONE;
1218:
1.161 andreas 1219: if (active_state->newkeys[MODE_IN] != NULL) {
1220: enc = &active_state->newkeys[MODE_IN]->enc;
1221: mac = &active_state->newkeys[MODE_IN]->mac;
1222: comp = &active_state->newkeys[MODE_IN]->comp;
1.25 markus 1223: }
1224: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1225: block_size = enc ? enc->block_size : 8;
1.25 markus 1226:
1.161 andreas 1227: if (active_state->packlen == 0) {
1.25 markus 1228: /*
1229: * check if input size is less than the cipher block size,
1230: * decrypt first block and extract length of incoming packet
1231: */
1.161 andreas 1232: if (buffer_len(&active_state->input) < block_size)
1.25 markus 1233: return SSH_MSG_NONE;
1.161 andreas 1234: buffer_clear(&active_state->incoming_packet);
1235: cp = buffer_append_space(&active_state->incoming_packet,
1.25 markus 1236: block_size);
1.161 andreas 1237: cipher_crypt(&active_state->receive_context, cp,
1238: buffer_ptr(&active_state->input), block_size);
1239: cp = buffer_ptr(&active_state->incoming_packet);
1240: active_state->packlen = get_u32(cp);
1241: if (active_state->packlen < 1 + 4 ||
1242: active_state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1243: #ifdef PACKET_DEBUG
1.161 andreas 1244: buffer_dump(&active_state->incoming_packet);
1.110 markus 1245: #endif
1.161 andreas 1246: logit("Bad packet length %u.", active_state->packlen);
1247: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1248: PACKET_MAX_SIZE);
1249: return SSH_MSG_NONE;
1.25 markus 1250: }
1.161 andreas 1251: DBG(debug("input: packet len %u", active_state->packlen+4));
1252: buffer_consume(&active_state->input, block_size);
1.25 markus 1253: }
1254: /* we have a partial packet of block_size bytes */
1.161 andreas 1255: need = 4 + active_state->packlen - block_size;
1.25 markus 1256: DBG(debug("partial packet %d, need %d, maclen %d", block_size,
1257: need, maclen));
1.158 markus 1258: if (need % block_size != 0) {
1259: logit("padding error: need %d block %d mod %d",
1.25 markus 1260: need, block_size, need % block_size);
1.161 andreas 1261: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1262: PACKET_MAX_SIZE - block_size);
1263: return SSH_MSG_NONE;
1.158 markus 1264: }
1.25 markus 1265: /*
1266: * check if the entire packet has been received and
1267: * decrypt into incoming_packet
1268: */
1.161 andreas 1269: if (buffer_len(&active_state->input) < need + maclen)
1.25 markus 1270: return SSH_MSG_NONE;
1271: #ifdef PACKET_DEBUG
1272: fprintf(stderr, "read_poll enc/full: ");
1.161 andreas 1273: buffer_dump(&active_state->input);
1.25 markus 1274: #endif
1.161 andreas 1275: cp = buffer_append_space(&active_state->incoming_packet, need);
1276: cipher_crypt(&active_state->receive_context, cp,
1277: buffer_ptr(&active_state->input), need);
1278: buffer_consume(&active_state->input, need);
1.25 markus 1279: /*
1280: * compute MAC over seqnr and packet,
1281: * increment sequence number for incoming packet
1282: */
1.29 markus 1283: if (mac && mac->enabled) {
1.161 andreas 1284: macbuf = mac_compute(mac, active_state->p_read.seqnr,
1285: buffer_ptr(&active_state->incoming_packet),
1286: buffer_len(&active_state->incoming_packet));
1287: if (memcmp(macbuf, buffer_ptr(&active_state->input),
1288: mac->mac_len) != 0) {
1.159 markus 1289: logit("Corrupted MAC on input.");
1290: if (need > PACKET_MAX_SIZE)
1291: fatal("internal error need %d", need);
1.161 andreas 1292: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1293: PACKET_MAX_SIZE - need);
1294: return SSH_MSG_NONE;
1295: }
1296:
1.161 andreas 1297: DBG(debug("MAC #%d ok", active_state->p_read.seqnr));
1298: buffer_consume(&active_state->input, mac->mac_len);
1.25 markus 1299: }
1.159 markus 1300: /* XXX now it's safe to use fatal/packet_disconnect */
1.77 djm 1301: if (seqnr_p != NULL)
1.161 andreas 1302: *seqnr_p = active_state->p_read.seqnr;
1303: if (++active_state->p_read.seqnr == 0)
1.106 itojun 1304: logit("incoming seqnr wraps around");
1.161 andreas 1305: if (++active_state->p_read.packets == 0)
1.105 markus 1306: if (!(datafellows & SSH_BUG_NOREKEY))
1307: fatal("XXX too many packets with same key");
1.161 andreas 1308: active_state->p_read.blocks += (active_state->packlen + 4) / block_size;
1309: active_state->p_read.bytes += active_state->packlen + 4;
1.25 markus 1310:
1311: /* get padlen */
1.161 andreas 1312: cp = buffer_ptr(&active_state->incoming_packet);
1.89 markus 1313: padlen = cp[4];
1.25 markus 1314: DBG(debug("input: padlen %d", padlen));
1315: if (padlen < 4)
1316: packet_disconnect("Corrupted padlen %d on input.", padlen);
1317:
1318: /* skip packet size + padlen, discard padding */
1.161 andreas 1319: buffer_consume(&active_state->incoming_packet, 4 + 1);
1320: buffer_consume_end(&active_state->incoming_packet, padlen);
1.25 markus 1321:
1.161 andreas 1322: DBG(debug("input: len before de-compress %d",
1323: buffer_len(&active_state->incoming_packet)));
1.25 markus 1324: if (comp && comp->enabled) {
1.161 andreas 1325: buffer_clear(&active_state->compression_buffer);
1326: buffer_uncompress(&active_state->incoming_packet,
1327: &active_state->compression_buffer);
1328: buffer_clear(&active_state->incoming_packet);
1329: buffer_append(&active_state->incoming_packet,
1330: buffer_ptr(&active_state->compression_buffer),
1331: buffer_len(&active_state->compression_buffer));
1.97 deraadt 1332: DBG(debug("input: len after de-compress %d",
1.161 andreas 1333: buffer_len(&active_state->incoming_packet)));
1.25 markus 1334: }
1335: /*
1336: * get packet type, implies consume.
1337: * return length of payload (without type field)
1338: */
1.161 andreas 1339: type = buffer_get_char(&active_state->incoming_packet);
1.116 markus 1340: if (type < SSH2_MSG_MIN || type >= SSH2_MSG_LOCAL_MIN)
1341: packet_disconnect("Invalid ssh2 packet type: %d", type);
1.57 markus 1342: if (type == SSH2_MSG_NEWKEYS)
1343: set_newkeys(MODE_IN);
1.161 andreas 1344: else if (type == SSH2_MSG_USERAUTH_SUCCESS &&
1345: !active_state->server_side)
1.118 markus 1346: packet_enable_delayed_compress();
1.25 markus 1347: #ifdef PACKET_DEBUG
1.55 deraadt 1348: fprintf(stderr, "read/plain[%d]:\r\n", type);
1.161 andreas 1349: buffer_dump(&active_state->incoming_packet);
1.25 markus 1350: #endif
1.62 markus 1351: /* reset for next packet */
1.161 andreas 1352: active_state->packlen = 0;
1.62 markus 1353: return type;
1.25 markus 1354: }
1355:
1356: int
1.82 markus 1357: packet_read_poll_seqnr(u_int32_t *seqnr_p)
1.25 markus 1358: {
1.96 deraadt 1359: u_int reason, seqnr;
1.62 markus 1360: u_char type;
1.25 markus 1361: char *msg;
1.62 markus 1362:
1.25 markus 1363: for (;;) {
1.62 markus 1364: if (compat20) {
1.82 markus 1365: type = packet_read_poll2(seqnr_p);
1.153 djm 1366: if (type) {
1.161 andreas 1367: active_state->keep_alive_timeouts = 0;
1.25 markus 1368: DBG(debug("received packet type %d", type));
1.153 djm 1369: }
1.74 deraadt 1370: switch (type) {
1.150 dtucker 1371: case SSH2_MSG_IGNORE:
1.151 dtucker 1372: debug3("Received SSH2_MSG_IGNORE");
1.150 dtucker 1373: break;
1.25 markus 1374: case SSH2_MSG_DEBUG:
1375: packet_get_char();
1376: msg = packet_get_string(NULL);
1377: debug("Remote: %.900s", msg);
1378: xfree(msg);
1379: msg = packet_get_string(NULL);
1380: xfree(msg);
1381: break;
1382: case SSH2_MSG_DISCONNECT:
1383: reason = packet_get_int();
1384: msg = packet_get_string(NULL);
1.106 itojun 1385: logit("Received disconnect from %s: %u: %.400s",
1.96 deraadt 1386: get_remote_ipaddr(), reason, msg);
1.25 markus 1387: xfree(msg);
1.112 markus 1388: cleanup_exit(255);
1.84 markus 1389: break;
1390: case SSH2_MSG_UNIMPLEMENTED:
1391: seqnr = packet_get_int();
1.96 deraadt 1392: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1393: seqnr);
1.150 dtucker 1394: break;
1.25 markus 1395: default:
1396: return type;
1.48 stevesk 1397: }
1.25 markus 1398: } else {
1.82 markus 1399: type = packet_read_poll1();
1.74 deraadt 1400: switch (type) {
1.25 markus 1401: case SSH_MSG_IGNORE:
1402: break;
1403: case SSH_MSG_DEBUG:
1404: msg = packet_get_string(NULL);
1405: debug("Remote: %.900s", msg);
1406: xfree(msg);
1407: break;
1408: case SSH_MSG_DISCONNECT:
1409: msg = packet_get_string(NULL);
1.106 itojun 1410: logit("Received disconnect from %s: %.400s",
1.96 deraadt 1411: get_remote_ipaddr(), msg);
1.112 markus 1412: cleanup_exit(255);
1.25 markus 1413: break;
1414: default:
1.62 markus 1415: if (type)
1.25 markus 1416: DBG(debug("received packet type %d", type));
1417: return type;
1.48 stevesk 1418: }
1.25 markus 1419: }
1420: }
1.77 djm 1421: }
1422:
1423: int
1.82 markus 1424: packet_read_poll(void)
1.77 djm 1425: {
1.82 markus 1426: return packet_read_poll_seqnr(NULL);
1.25 markus 1427: }
1428:
1.16 markus 1429: /*
1430: * Buffers the given amount of input characters. This is intended to be used
1431: * together with packet_read_poll.
1432: */
1.1 deraadt 1433:
1.2 provos 1434: void
1.40 markus 1435: packet_process_incoming(const char *buf, u_int len)
1.1 deraadt 1436: {
1.161 andreas 1437: if (active_state->packet_discard) {
1438: active_state->keep_alive_timeouts = 0; /* ?? */
1439: if (len >= active_state->packet_discard)
1.159 markus 1440: packet_stop_discard();
1.161 andreas 1441: active_state->packet_discard -= len;
1.159 markus 1442: return;
1443: }
1.161 andreas 1444: buffer_append(&active_state->input, buf, len);
1.1 deraadt 1445: }
1446:
1447: /* Returns a character from the packet. */
1448:
1.40 markus 1449: u_int
1.73 itojun 1450: packet_get_char(void)
1.1 deraadt 1451: {
1.14 markus 1452: char ch;
1.97 deraadt 1453:
1.161 andreas 1454: buffer_get(&active_state->incoming_packet, &ch, 1);
1.40 markus 1455: return (u_char) ch;
1.1 deraadt 1456: }
1457:
1458: /* Returns an integer from the packet data. */
1459:
1.40 markus 1460: u_int
1.73 itojun 1461: packet_get_int(void)
1.1 deraadt 1462: {
1.161 andreas 1463: return buffer_get_int(&active_state->incoming_packet);
1.162 ! andreas 1464: }
! 1465:
! 1466: /* Returns an 64 bit integer from the packet data. */
! 1467:
! 1468: u_int64_t
! 1469: packet_get_int64(void)
! 1470: {
! 1471: return buffer_get_int64(&active_state->incoming_packet);
1.1 deraadt 1472: }
1473:
1.16 markus 1474: /*
1475: * Returns an arbitrary precision integer from the packet data. The integer
1476: * must have been initialized before this call.
1477: */
1.1 deraadt 1478:
1.2 provos 1479: void
1.80 markus 1480: packet_get_bignum(BIGNUM * value)
1.1 deraadt 1481: {
1.161 andreas 1482: buffer_get_bignum(&active_state->incoming_packet, value);
1.24 markus 1483: }
1484:
1485: void
1.80 markus 1486: packet_get_bignum2(BIGNUM * value)
1.24 markus 1487: {
1.161 andreas 1488: buffer_get_bignum2(&active_state->incoming_packet, value);
1.24 markus 1489: }
1490:
1.76 stevesk 1491: void *
1.117 djm 1492: packet_get_raw(u_int *length_ptr)
1.24 markus 1493: {
1.161 andreas 1494: u_int bytes = buffer_len(&active_state->incoming_packet);
1.97 deraadt 1495:
1.24 markus 1496: if (length_ptr != NULL)
1497: *length_ptr = bytes;
1.161 andreas 1498: return buffer_ptr(&active_state->incoming_packet);
1.28 markus 1499: }
1500:
1501: int
1502: packet_remaining(void)
1503: {
1.161 andreas 1504: return buffer_len(&active_state->incoming_packet);
1.1 deraadt 1505: }
1506:
1.16 markus 1507: /*
1508: * Returns a string from the packet data. The string is allocated using
1509: * xmalloc; it is the responsibility of the calling program to free it when
1510: * no longer needed. The length_ptr argument may be NULL, or point to an
1511: * integer into which the length of the string is stored.
1512: */
1.1 deraadt 1513:
1.76 stevesk 1514: void *
1.40 markus 1515: packet_get_string(u_int *length_ptr)
1.1 deraadt 1516: {
1.161 andreas 1517: return buffer_get_string(&active_state->incoming_packet, length_ptr);
1.152 markus 1518: }
1519:
1520: void *
1521: packet_get_string_ptr(u_int *length_ptr)
1522: {
1.161 andreas 1523: return buffer_get_string_ptr(&active_state->incoming_packet, length_ptr);
1.1 deraadt 1524: }
1525:
1.16 markus 1526: /*
1527: * Sends a diagnostic message from the server to the client. This message
1528: * can be sent at any time (but not while constructing another message). The
1529: * message is printed immediately, but only if the client is being executed
1530: * in verbose mode. These messages are primarily intended to ease debugging
1531: * authentication problems. The length of the formatted message must not
1532: * exceed 1024 bytes. This will automatically call packet_write_wait.
1533: */
1.1 deraadt 1534:
1.2 provos 1535: void
1.14 markus 1536: packet_send_debug(const char *fmt,...)
1.1 deraadt 1537: {
1.14 markus 1538: char buf[1024];
1539: va_list args;
1.39 markus 1540:
1541: if (compat20 && (datafellows & SSH_BUG_DEBUG))
1542: return;
1.14 markus 1543:
1544: va_start(args, fmt);
1545: vsnprintf(buf, sizeof(buf), fmt, args);
1546: va_end(args);
1547:
1.30 markus 1548: if (compat20) {
1549: packet_start(SSH2_MSG_DEBUG);
1550: packet_put_char(0); /* bool: always display */
1551: packet_put_cstring(buf);
1552: packet_put_cstring("");
1553: } else {
1554: packet_start(SSH_MSG_DEBUG);
1555: packet_put_cstring(buf);
1556: }
1.14 markus 1557: packet_send();
1558: packet_write_wait();
1.1 deraadt 1559: }
1560:
1.16 markus 1561: /*
1562: * Logs the error plus constructs and sends a disconnect packet, closes the
1563: * connection, and exits. This function never returns. The error message
1564: * should not contain a newline. The length of the formatted message must
1565: * not exceed 1024 bytes.
1566: */
1.1 deraadt 1567:
1.2 provos 1568: void
1.14 markus 1569: packet_disconnect(const char *fmt,...)
1.1 deraadt 1570: {
1.14 markus 1571: char buf[1024];
1572: va_list args;
1573: static int disconnecting = 0;
1.97 deraadt 1574:
1.14 markus 1575: if (disconnecting) /* Guard against recursive invocations. */
1576: fatal("packet_disconnect called recursively.");
1577: disconnecting = 1;
1578:
1.16 markus 1579: /*
1580: * Format the message. Note that the caller must make sure the
1581: * message is of limited size.
1582: */
1.14 markus 1583: va_start(args, fmt);
1584: vsnprintf(buf, sizeof(buf), fmt, args);
1585: va_end(args);
1586:
1.99 markus 1587: /* Display the error locally */
1.106 itojun 1588: logit("Disconnecting: %.100s", buf);
1.99 markus 1589:
1.14 markus 1590: /* Send the disconnect message to the other side, and wait for it to get sent. */
1.25 markus 1591: if (compat20) {
1592: packet_start(SSH2_MSG_DISCONNECT);
1593: packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR);
1594: packet_put_cstring(buf);
1595: packet_put_cstring("");
1596: } else {
1597: packet_start(SSH_MSG_DISCONNECT);
1.65 markus 1598: packet_put_cstring(buf);
1.25 markus 1599: }
1.14 markus 1600: packet_send();
1601: packet_write_wait();
1602:
1603: /* Stop listening for connections. */
1.67 markus 1604: channel_close_all();
1.14 markus 1605:
1606: /* Close the connection. */
1607: packet_close();
1.112 markus 1608: cleanup_exit(255);
1.1 deraadt 1609: }
1610:
1.16 markus 1611: /* Checks if there is any buffered output, and tries to write some of the output. */
1.1 deraadt 1612:
1.2 provos 1613: void
1.73 itojun 1614: packet_write_poll(void)
1.1 deraadt 1615: {
1.161 andreas 1616: int len = buffer_len(&active_state->output);
1.97 deraadt 1617:
1.14 markus 1618: if (len > 0) {
1.161 andreas 1619: len = write(active_state->connection_out,
1620: buffer_ptr(&active_state->output), len);
1.156 djm 1621: if (len == -1) {
1622: if (errno == EINTR || errno == EAGAIN)
1.14 markus 1623: return;
1.156 djm 1624: fatal("Write failed: %.100s", strerror(errno));
1.14 markus 1625: }
1.156 djm 1626: if (len == 0)
1627: fatal("Write connection closed");
1.161 andreas 1628: buffer_consume(&active_state->output, len);
1.14 markus 1629: }
1.1 deraadt 1630: }
1631:
1.16 markus 1632: /*
1633: * Calls packet_write_poll repeatedly until all pending output data has been
1634: * written.
1635: */
1.1 deraadt 1636:
1.2 provos 1637: void
1.73 itojun 1638: packet_write_wait(void)
1.1 deraadt 1639: {
1.56 millert 1640: fd_set *setp;
1.154 dtucker 1641: int ret, ms_remain;
1642: struct timeval start, timeout, *timeoutp = NULL;
1.56 millert 1643:
1.161 andreas 1644: setp = (fd_set *)xcalloc(howmany(active_state->connection_out + 1,
1645: NFDBITS), sizeof(fd_mask));
1.14 markus 1646: packet_write_poll();
1647: while (packet_have_data_to_write()) {
1.161 andreas 1648: memset(setp, 0, howmany(active_state->connection_out + 1,
1649: NFDBITS) * sizeof(fd_mask));
1650: FD_SET(active_state->connection_out, setp);
1.154 dtucker 1651:
1.161 andreas 1652: if (active_state->packet_timeout_ms > 0) {
1653: ms_remain = active_state->packet_timeout_ms;
1.154 dtucker 1654: timeoutp = &timeout;
1655: }
1656: for (;;) {
1.161 andreas 1657: if (active_state->packet_timeout_ms != -1) {
1.154 dtucker 1658: ms_to_timeval(&timeout, ms_remain);
1659: gettimeofday(&start, NULL);
1660: }
1.161 andreas 1661: if ((ret = select(active_state->connection_out + 1,
1662: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1663: break;
1.161 andreas 1664: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1665: break;
1.161 andreas 1666: if (active_state->packet_timeout_ms == -1)
1.154 dtucker 1667: continue;
1668: ms_subtract_diff(&start, &ms_remain);
1669: if (ms_remain <= 0) {
1670: ret = 0;
1671: break;
1672: }
1673: }
1674: if (ret == 0) {
1675: logit("Connection to %.200s timed out while "
1676: "waiting to write", get_remote_ipaddr());
1677: cleanup_exit(255);
1678: }
1.14 markus 1679: packet_write_poll();
1680: }
1.56 millert 1681: xfree(setp);
1.1 deraadt 1682: }
1683:
1684: /* Returns true if there is buffered data to write to the connection. */
1685:
1.2 provos 1686: int
1.73 itojun 1687: packet_have_data_to_write(void)
1.1 deraadt 1688: {
1.161 andreas 1689: return buffer_len(&active_state->output) != 0;
1.1 deraadt 1690: }
1691:
1692: /* Returns true if there is not too much data to write to the connection. */
1693:
1.2 provos 1694: int
1.73 itojun 1695: packet_not_very_much_data_to_write(void)
1.1 deraadt 1696: {
1.161 andreas 1697: if (active_state->interactive_mode)
1698: return buffer_len(&active_state->output) < 16384;
1.14 markus 1699: else
1.161 andreas 1700: return buffer_len(&active_state->output) < 128 * 1024;
1.1 deraadt 1701: }
1702:
1.102 markus 1703: static void
1.101 markus 1704: packet_set_tos(int interactive)
1705: {
1706: int tos = interactive ? IPTOS_LOWDELAY : IPTOS_THROUGHPUT;
1707:
1708: if (!packet_connection_is_on_socket() ||
1709: !packet_connection_is_ipv4())
1710: return;
1.161 andreas 1711: if (setsockopt(active_state->connection_in, IPPROTO_IP, IP_TOS, &tos,
1.101 markus 1712: sizeof(tos)) < 0)
1713: error("setsockopt IP_TOS %d: %.100s:",
1714: tos, strerror(errno));
1715: }
1716:
1.1 deraadt 1717: /* Informs that the current session is interactive. Sets IP flags for that. */
1718:
1.2 provos 1719: void
1.43 markus 1720: packet_set_interactive(int interactive)
1.1 deraadt 1721: {
1.43 markus 1722: static int called = 0;
1.44 markus 1723:
1.43 markus 1724: if (called)
1725: return;
1726: called = 1;
1.1 deraadt 1727:
1.14 markus 1728: /* Record that we are in interactive mode. */
1.161 andreas 1729: active_state->interactive_mode = interactive;
1.1 deraadt 1730:
1.19 markus 1731: /* Only set socket options if using a socket. */
1732: if (!packet_connection_is_on_socket())
1.14 markus 1733: return;
1.161 andreas 1734: set_nodelay(active_state->connection_in);
1.101 markus 1735: packet_set_tos(interactive);
1.1 deraadt 1736: }
1737:
1738: /* Returns true if the current connection is interactive. */
1739:
1.2 provos 1740: int
1.73 itojun 1741: packet_is_interactive(void)
1.1 deraadt 1742: {
1.161 andreas 1743: return active_state->interactive_mode;
1.12 markus 1744: }
1745:
1.113 deraadt 1746: int
1.108 markus 1747: packet_set_maxsize(u_int s)
1.12 markus 1748: {
1.14 markus 1749: static int called = 0;
1.97 deraadt 1750:
1.14 markus 1751: if (called) {
1.106 itojun 1752: logit("packet_set_maxsize: called twice: old %d new %d",
1.161 andreas 1753: active_state->max_packet_size, s);
1.14 markus 1754: return -1;
1755: }
1756: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 1757: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 1758: return -1;
1759: }
1.70 markus 1760: called = 1;
1.66 markus 1761: debug("packet_set_maxsize: setting to %d", s);
1.161 andreas 1762: active_state->max_packet_size = s;
1.14 markus 1763: return s;
1.53 markus 1764: }
1765:
1.161 andreas 1766: int
1767: packet_inc_alive_timeouts(void)
1768: {
1769: return ++active_state->keep_alive_timeouts;
1770: }
1771:
1772: void
1773: packet_set_alive_timeouts(int ka)
1774: {
1775: active_state->keep_alive_timeouts = ka;
1776: }
1777:
1778: u_int
1779: packet_get_maxsize(void)
1780: {
1781: return active_state->max_packet_size;
1782: }
1783:
1.71 markus 1784: /* roundup current message to pad bytes */
1785: void
1786: packet_add_padding(u_char pad)
1787: {
1.161 andreas 1788: active_state->extra_pad = pad;
1.71 markus 1789: }
1790:
1.53 markus 1791: /*
1792: * 9.2. Ignored Data Message
1.61 markus 1793: *
1.53 markus 1794: * byte SSH_MSG_IGNORE
1795: * string data
1.61 markus 1796: *
1.53 markus 1797: * All implementations MUST understand (and ignore) this message at any
1798: * time (after receiving the protocol version). No implementation is
1799: * required to send them. This message can be used as an additional
1800: * protection measure against advanced traffic analysis techniques.
1801: */
1.54 markus 1802: void
1803: packet_send_ignore(int nbytes)
1804: {
1.115 avsm 1805: u_int32_t rnd = 0;
1.54 markus 1806: int i;
1807:
1808: packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE);
1.53 markus 1809: packet_put_int(nbytes);
1.75 deraadt 1810: for (i = 0; i < nbytes; i++) {
1.53 markus 1811: if (i % 4 == 0)
1.115 avsm 1812: rnd = arc4random();
1.129 deraadt 1813: packet_put_char((u_char)rnd & 0xff);
1.115 avsm 1814: rnd >>= 8;
1.53 markus 1815: }
1.105 markus 1816: }
1817:
1.113 deraadt 1818: #define MAX_PACKETS (1U<<31)
1.105 markus 1819: int
1820: packet_need_rekeying(void)
1821: {
1822: if (datafellows & SSH_BUG_NOREKEY)
1823: return 0;
1824: return
1.161 andreas 1825: (active_state->p_send.packets > MAX_PACKETS) ||
1826: (active_state->p_read.packets > MAX_PACKETS) ||
1827: (active_state->max_blocks_out &&
1828: (active_state->p_send.blocks > active_state->max_blocks_out)) ||
1829: (active_state->max_blocks_in &&
1830: (active_state->p_read.blocks > active_state->max_blocks_in));
1.105 markus 1831: }
1832:
1833: void
1834: packet_set_rekey_limit(u_int32_t bytes)
1835: {
1.161 andreas 1836: active_state->rekey_limit = bytes;
1.118 markus 1837: }
1838:
1839: void
1840: packet_set_server(void)
1841: {
1.161 andreas 1842: active_state->server_side = 1;
1.118 markus 1843: }
1844:
1845: void
1846: packet_set_authenticated(void)
1847: {
1.161 andreas 1848: active_state->after_authentication = 1;
1849: }
1850:
1851: void *
1852: packet_get_input(void)
1853: {
1854: return (void *)&active_state->input;
1855: }
1856:
1857: void *
1858: packet_get_output(void)
1859: {
1860: return (void *)&active_state->output;
1861: }
1862:
1863: void *
1864: packet_get_newkeys(int mode)
1865: {
1866: return (void *)active_state->newkeys[mode];
1.1 deraadt 1867: }
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