Annotation of src/usr.bin/ssh/packet.c, Revision 1.199
1.199 ! lteo 1: /* $OpenBSD: packet.c,v 1.198 2014/07/15 15:54:14 millert 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:
1.132 stevesk 46: #include <netinet/in.h>
1.121 stevesk 47: #include <netinet/ip.h>
1.134 stevesk 48:
1.135 stevesk 49: #include <errno.h>
1.134 stevesk 50: #include <stdarg.h>
1.141 stevesk 51: #include <stdio.h>
1.140 stevesk 52: #include <stdlib.h>
1.137 stevesk 53: #include <string.h>
1.136 stevesk 54: #include <unistd.h>
1.142 deraadt 55: #include <signal.h>
1.184 dtucker 56: #include <time.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"
1.25 markus 64: #include "compat.h"
1.45 markus 65: #include "ssh1.h"
1.25 markus 66: #include "ssh2.h"
1.37 markus 67: #include "cipher.h"
1.142 deraadt 68: #include "key.h"
1.25 markus 69: #include "kex.h"
1.50 markus 70: #include "mac.h"
1.46 markus 71: #include "log.h"
72: #include "canohost.h"
1.87 stevesk 73: #include "misc.h"
1.198 millert 74: #include "channels.h"
1.95 markus 75: #include "ssh.h"
1.197 djm 76: #include "ssherr.h"
1.163 andreas 77: #include "roaming.h"
1.25 markus 78:
79: #ifdef PACKET_DEBUG
80: #define DBG(x) x
81: #else
82: #define DBG(x)
83: #endif
84:
1.159 markus 85: #define PACKET_MAX_SIZE (256 * 1024)
86:
1.161 andreas 87: struct packet_state {
88: u_int32_t seqnr;
89: u_int32_t packets;
90: u_int64_t blocks;
91: u_int64_t bytes;
92: };
93:
94: struct packet {
95: TAILQ_ENTRY(packet) next;
96: u_char type;
97: Buffer payload;
98: };
99:
100: struct session_state {
101: /*
102: * This variable contains the file descriptors used for
103: * communicating with the other side. connection_in is used for
104: * reading; connection_out for writing. These can be the same
105: * descriptor, in which case it is assumed to be a socket.
106: */
107: int connection_in;
108: int connection_out;
109:
110: /* Protocol flags for the remote side. */
111: u_int remote_protocol_flags;
1.1 deraadt 112:
1.161 andreas 113: /* Encryption context for receiving data. Only used for decryption. */
114: CipherContext receive_context;
1.1 deraadt 115:
1.161 andreas 116: /* Encryption context for sending data. Only used for encryption. */
117: CipherContext send_context;
1.14 markus 118:
1.161 andreas 119: /* Buffer for raw input data from the socket. */
120: Buffer input;
1.1 deraadt 121:
1.161 andreas 122: /* Buffer for raw output data going to the socket. */
123: Buffer output;
1.1 deraadt 124:
1.161 andreas 125: /* Buffer for the partial outgoing packet being constructed. */
126: Buffer outgoing_packet;
1.1 deraadt 127:
1.161 andreas 128: /* Buffer for the incoming packet currently being processed. */
129: Buffer incoming_packet;
1.1 deraadt 130:
1.161 andreas 131: /* Scratch buffer for packet compression/decompression. */
132: Buffer compression_buffer;
133: int compression_buffer_ready;
1.1 deraadt 134:
1.161 andreas 135: /*
136: * Flag indicating whether packet compression/decompression is
137: * enabled.
138: */
139: int packet_compression;
1.1 deraadt 140:
1.161 andreas 141: /* default maximum packet size */
142: u_int max_packet_size;
1.1 deraadt 143:
1.161 andreas 144: /* Flag indicating whether this module has been initialized. */
145: int initialized;
1.12 markus 146:
1.161 andreas 147: /* Set to true if the connection is interactive. */
148: int interactive_mode;
1.1 deraadt 149:
1.161 andreas 150: /* Set to true if we are the server side. */
151: int server_side;
1.1 deraadt 152:
1.161 andreas 153: /* Set to true if we are authenticated. */
154: int after_authentication;
1.118 markus 155:
1.161 andreas 156: int keep_alive_timeouts;
1.118 markus 157:
1.161 andreas 158: /* The maximum time that we will wait to send or receive a packet */
159: int packet_timeout_ms;
1.151 dtucker 160:
1.161 andreas 161: /* Session key information for Encryption and MAC */
162: Newkeys *newkeys[MODE_MAX];
163: struct packet_state p_read, p_send;
1.154 dtucker 164:
1.184 dtucker 165: /* Volume-based rekeying */
1.161 andreas 166: u_int64_t max_blocks_in, max_blocks_out;
167: u_int32_t rekey_limit;
1.105 markus 168:
1.184 dtucker 169: /* Time-based rekeying */
170: time_t rekey_interval; /* how often in seconds */
171: time_t rekey_time; /* time of last rekeying */
172:
1.161 andreas 173: /* Session key for protocol v1 */
174: u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
175: u_int ssh1_keylen;
1.25 markus 176:
1.161 andreas 177: /* roundup current message to extra_pad bytes */
178: u_char extra_pad;
1.95 markus 179:
1.161 andreas 180: /* XXX discard incoming data after MAC error */
181: u_int packet_discard;
182: Mac *packet_discard_mac;
1.71 markus 183:
1.161 andreas 184: /* Used in packet_read_poll2() */
185: u_int packlen;
1.159 markus 186:
1.165 andreas 187: /* Used in packet_send2 */
188: int rekeying;
189:
190: /* Used in packet_set_interactive */
191: int set_interactive_called;
192:
193: /* Used in packet_set_maxsize */
194: int set_maxsize_called;
195:
1.161 andreas 196: TAILQ_HEAD(, packet) outgoing;
1.105 markus 197: };
1.161 andreas 198:
1.166 andreas 199: static struct session_state *active_state, *backup_state;
1.161 andreas 200:
201: static struct session_state *
1.164 andreas 202: alloc_session_state(void)
1.161 andreas 203: {
1.171 djm 204: struct session_state *s = xcalloc(1, sizeof(*s));
1.161 andreas 205:
1.171 djm 206: s->connection_in = -1;
207: s->connection_out = -1;
208: s->max_packet_size = 32768;
209: s->packet_timeout_ms = -1;
210: return s;
1.161 andreas 211: }
1.105 markus 212:
1.16 markus 213: /*
214: * Sets the descriptors used for communication. Disables encryption until
215: * packet_set_encryption_key is called.
216: */
1.2 provos 217: void
218: packet_set_connection(int fd_in, int fd_out)
1.1 deraadt 219: {
1.183 djm 220: const Cipher *none = cipher_by_name("none");
1.197 djm 221: int r;
1.97 deraadt 222:
1.37 markus 223: if (none == NULL)
224: fatal("packet_set_connection: cannot load cipher 'none'");
1.161 andreas 225: if (active_state == NULL)
226: active_state = alloc_session_state();
227: active_state->connection_in = fd_in;
228: active_state->connection_out = fd_out;
1.197 djm 229: if ((r = cipher_init(&active_state->send_context, none,
230: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
231: (r = cipher_init(&active_state->receive_context, none,
232: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0)
233: fatal("%s: cipher_init: %s", __func__, ssh_err(r));
1.161 andreas 234: active_state->newkeys[MODE_IN] = active_state->newkeys[MODE_OUT] = NULL;
235: if (!active_state->initialized) {
236: active_state->initialized = 1;
237: buffer_init(&active_state->input);
238: buffer_init(&active_state->output);
239: buffer_init(&active_state->outgoing_packet);
240: buffer_init(&active_state->incoming_packet);
241: TAILQ_INIT(&active_state->outgoing);
242: active_state->p_send.packets = active_state->p_read.packets = 0;
1.14 markus 243: }
1.1 deraadt 244: }
245:
1.154 dtucker 246: void
247: packet_set_timeout(int timeout, int count)
248: {
1.174 djm 249: if (timeout <= 0 || count <= 0) {
1.161 andreas 250: active_state->packet_timeout_ms = -1;
1.154 dtucker 251: return;
252: }
253: if ((INT_MAX / 1000) / count < timeout)
1.161 andreas 254: active_state->packet_timeout_ms = INT_MAX;
1.154 dtucker 255: else
1.161 andreas 256: active_state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 257: }
258:
1.159 markus 259: static void
260: packet_stop_discard(void)
261: {
1.161 andreas 262: if (active_state->packet_discard_mac) {
1.159 markus 263: char buf[1024];
264:
265: memset(buf, 'a', sizeof(buf));
1.161 andreas 266: while (buffer_len(&active_state->incoming_packet) <
267: PACKET_MAX_SIZE)
268: buffer_append(&active_state->incoming_packet, buf,
269: sizeof(buf));
270: (void) mac_compute(active_state->packet_discard_mac,
271: active_state->p_read.seqnr,
272: buffer_ptr(&active_state->incoming_packet),
1.159 markus 273: PACKET_MAX_SIZE);
274: }
275: logit("Finished discarding for %.200s", get_remote_ipaddr());
276: cleanup_exit(255);
277: }
278:
279: static void
280: packet_start_discard(Enc *enc, Mac *mac, u_int packet_length, u_int discard)
281: {
1.178 markus 282: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm))
1.159 markus 283: packet_disconnect("Packet corrupt");
284: if (packet_length != PACKET_MAX_SIZE && mac && mac->enabled)
1.161 andreas 285: active_state->packet_discard_mac = mac;
286: if (buffer_len(&active_state->input) >= discard)
1.159 markus 287: packet_stop_discard();
1.161 andreas 288: active_state->packet_discard = discard -
289: buffer_len(&active_state->input);
1.159 markus 290: }
291:
1.19 markus 292: /* Returns 1 if remote host is connected via socket, 0 if not. */
293:
294: int
1.73 itojun 295: packet_connection_is_on_socket(void)
1.19 markus 296: {
297: struct sockaddr_storage from, to;
298: socklen_t fromlen, tolen;
299:
300: /* filedescriptors in and out are the same, so it's a socket */
1.161 andreas 301: if (active_state->connection_in == active_state->connection_out)
1.19 markus 302: return 1;
303: fromlen = sizeof(from);
304: memset(&from, 0, sizeof(from));
1.161 andreas 305: if (getpeername(active_state->connection_in, (struct sockaddr *)&from,
306: &fromlen) < 0)
1.19 markus 307: return 0;
308: tolen = sizeof(to);
309: memset(&to, 0, sizeof(to));
1.161 andreas 310: if (getpeername(active_state->connection_out, (struct sockaddr *)&to,
311: &tolen) < 0)
1.19 markus 312: return 0;
313: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
314: return 0;
315: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
316: return 0;
317: return 1;
318: }
319:
1.92 markus 320: /*
1.91 markus 321: * Exports an IV from the CipherContext required to export the key
322: * state back from the unprivileged child to the privileged parent
323: * process.
324: */
325:
326: void
327: packet_get_keyiv(int mode, u_char *iv, u_int len)
328: {
329: CipherContext *cc;
1.197 djm 330: int r;
1.91 markus 331:
332: if (mode == MODE_OUT)
1.161 andreas 333: cc = &active_state->send_context;
1.91 markus 334: else
1.161 andreas 335: cc = &active_state->receive_context;
1.91 markus 336:
1.197 djm 337: if ((r = cipher_get_keyiv(cc, iv, len)) != 0)
338: fatal("%s: cipher_get_keyiv: %s", __func__, ssh_err(r));
1.91 markus 339: }
340:
341: int
342: packet_get_keycontext(int mode, u_char *dat)
343: {
344: CipherContext *cc;
1.92 markus 345:
1.91 markus 346: if (mode == MODE_OUT)
1.161 andreas 347: cc = &active_state->send_context;
1.91 markus 348: else
1.161 andreas 349: cc = &active_state->receive_context;
1.91 markus 350:
351: return (cipher_get_keycontext(cc, dat));
352: }
353:
354: void
355: packet_set_keycontext(int mode, u_char *dat)
356: {
357: CipherContext *cc;
1.92 markus 358:
1.91 markus 359: if (mode == MODE_OUT)
1.161 andreas 360: cc = &active_state->send_context;
1.91 markus 361: else
1.161 andreas 362: cc = &active_state->receive_context;
1.91 markus 363:
364: cipher_set_keycontext(cc, dat);
365: }
366:
367: int
368: packet_get_keyiv_len(int mode)
369: {
370: CipherContext *cc;
371:
372: if (mode == MODE_OUT)
1.161 andreas 373: cc = &active_state->send_context;
1.91 markus 374: else
1.161 andreas 375: cc = &active_state->receive_context;
1.91 markus 376:
377: return (cipher_get_keyiv_len(cc));
378: }
1.125 deraadt 379:
1.91 markus 380: void
381: packet_set_iv(int mode, u_char *dat)
382: {
383: CipherContext *cc;
1.197 djm 384: int r;
1.91 markus 385:
386: if (mode == MODE_OUT)
1.161 andreas 387: cc = &active_state->send_context;
1.91 markus 388: else
1.161 andreas 389: cc = &active_state->receive_context;
1.91 markus 390:
1.197 djm 391: if ((r = cipher_set_keyiv(cc, dat)) != 0)
392: fatal("%s: cipher_set_keyiv: %s", __func__, ssh_err(r));
1.91 markus 393: }
1.125 deraadt 394:
1.91 markus 395: int
1.107 deraadt 396: packet_get_ssh1_cipher(void)
1.91 markus 397: {
1.161 andreas 398: return (cipher_get_number(active_state->receive_context.cipher));
1.91 markus 399: }
400:
1.105 markus 401: void
1.171 djm 402: packet_get_state(int mode, u_int32_t *seqnr, u_int64_t *blocks,
403: u_int32_t *packets, u_int64_t *bytes)
1.105 markus 404: {
405: struct packet_state *state;
1.104 markus 406:
1.161 andreas 407: state = (mode == MODE_IN) ?
408: &active_state->p_read : &active_state->p_send;
1.157 markus 409: if (seqnr)
410: *seqnr = state->seqnr;
411: if (blocks)
412: *blocks = state->blocks;
413: if (packets)
414: *packets = state->packets;
415: if (bytes)
416: *bytes = state->bytes;
1.91 markus 417: }
418:
419: void
1.157 markus 420: packet_set_state(int mode, u_int32_t seqnr, u_int64_t blocks, u_int32_t packets,
421: u_int64_t bytes)
1.91 markus 422: {
1.105 markus 423: struct packet_state *state;
424:
1.161 andreas 425: state = (mode == MODE_IN) ?
426: &active_state->p_read : &active_state->p_send;
1.105 markus 427: state->seqnr = seqnr;
428: state->blocks = blocks;
429: state->packets = packets;
1.157 markus 430: state->bytes = bytes;
1.91 markus 431: }
432:
1.173 djm 433: static int
434: packet_connection_af(void)
1.19 markus 435: {
436: struct sockaddr_storage to;
1.21 deraadt 437: socklen_t tolen = sizeof(to);
1.19 markus 438:
439: memset(&to, 0, sizeof(to));
1.161 andreas 440: if (getsockname(active_state->connection_out, (struct sockaddr *)&to,
441: &tolen) < 0)
1.19 markus 442: return 0;
1.173 djm 443: return to.ss_family;
1.19 markus 444: }
445:
1.1 deraadt 446: /* Sets the connection into non-blocking mode. */
447:
1.2 provos 448: void
1.73 itojun 449: packet_set_nonblocking(void)
1.1 deraadt 450: {
1.14 markus 451: /* Set the socket into non-blocking mode. */
1.161 andreas 452: set_nonblock(active_state->connection_in);
1.14 markus 453:
1.161 andreas 454: if (active_state->connection_out != active_state->connection_in)
455: set_nonblock(active_state->connection_out);
1.1 deraadt 456: }
457:
458: /* Returns the socket used for reading. */
459:
1.2 provos 460: int
1.73 itojun 461: packet_get_connection_in(void)
1.1 deraadt 462: {
1.161 andreas 463: return active_state->connection_in;
1.1 deraadt 464: }
465:
466: /* Returns the descriptor used for writing. */
467:
1.2 provos 468: int
1.73 itojun 469: packet_get_connection_out(void)
1.1 deraadt 470: {
1.161 andreas 471: return active_state->connection_out;
1.1 deraadt 472: }
473:
474: /* Closes the connection and clears and frees internal data structures. */
475:
1.2 provos 476: void
1.73 itojun 477: packet_close(void)
1.1 deraadt 478: {
1.161 andreas 479: if (!active_state->initialized)
1.14 markus 480: return;
1.161 andreas 481: active_state->initialized = 0;
482: if (active_state->connection_in == active_state->connection_out) {
483: shutdown(active_state->connection_out, SHUT_RDWR);
484: close(active_state->connection_out);
1.14 markus 485: } else {
1.161 andreas 486: close(active_state->connection_in);
487: close(active_state->connection_out);
1.14 markus 488: }
1.161 andreas 489: buffer_free(&active_state->input);
490: buffer_free(&active_state->output);
491: buffer_free(&active_state->outgoing_packet);
492: buffer_free(&active_state->incoming_packet);
493: if (active_state->compression_buffer_ready) {
494: buffer_free(&active_state->compression_buffer);
1.14 markus 495: buffer_compress_uninit();
496: }
1.161 andreas 497: cipher_cleanup(&active_state->send_context);
498: cipher_cleanup(&active_state->receive_context);
1.1 deraadt 499: }
500:
501: /* Sets remote side protocol flags. */
502:
1.2 provos 503: void
1.40 markus 504: packet_set_protocol_flags(u_int protocol_flags)
1.1 deraadt 505: {
1.161 andreas 506: active_state->remote_protocol_flags = protocol_flags;
1.1 deraadt 507: }
508:
509: /* Returns the remote protocol flags set earlier by the above function. */
510:
1.40 markus 511: u_int
1.73 itojun 512: packet_get_protocol_flags(void)
1.1 deraadt 513: {
1.161 andreas 514: return active_state->remote_protocol_flags;
1.1 deraadt 515: }
516:
1.16 markus 517: /*
518: * Starts packet compression from the next packet on in both directions.
519: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
520: */
1.1 deraadt 521:
1.68 itojun 522: static void
523: packet_init_compression(void)
1.60 markus 524: {
1.161 andreas 525: if (active_state->compression_buffer_ready == 1)
1.60 markus 526: return;
1.161 andreas 527: active_state->compression_buffer_ready = 1;
528: buffer_init(&active_state->compression_buffer);
1.60 markus 529: }
530:
1.2 provos 531: void
532: packet_start_compression(int level)
1.1 deraadt 533: {
1.161 andreas 534: if (active_state->packet_compression && !compat20)
1.14 markus 535: fatal("Compression already enabled.");
1.161 andreas 536: active_state->packet_compression = 1;
1.60 markus 537: packet_init_compression();
538: buffer_compress_init_send(level);
539: buffer_compress_init_recv();
1.1 deraadt 540: }
541:
1.16 markus 542: /*
543: * Causes any further packets to be encrypted using the given key. The same
544: * key is used for both sending and reception. However, both directions are
545: * encrypted independently of each other.
546: */
1.95 markus 547:
1.2 provos 548: void
1.171 djm 549: packet_set_encryption_key(const u_char *key, u_int keylen, int number)
1.1 deraadt 550: {
1.183 djm 551: const Cipher *cipher = cipher_by_number(number);
1.197 djm 552: int r;
1.97 deraadt 553:
1.37 markus 554: if (cipher == NULL)
555: fatal("packet_set_encryption_key: unknown cipher number %d", number);
1.25 markus 556: if (keylen < 20)
1.37 markus 557: fatal("packet_set_encryption_key: keylen too small: %d", keylen);
1.95 markus 558: if (keylen > SSH_SESSION_KEY_LENGTH)
559: fatal("packet_set_encryption_key: keylen too big: %d", keylen);
1.161 andreas 560: memcpy(active_state->ssh1_key, key, keylen);
561: active_state->ssh1_keylen = keylen;
1.197 djm 562: if ((r = cipher_init(&active_state->send_context, cipher,
563: key, keylen, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
564: (r = cipher_init(&active_state->receive_context, cipher,
565: key, keylen, NULL, 0, CIPHER_DECRYPT)) != 0)
566: fatal("%s: cipher_init: %s", __func__, ssh_err(r));
1.95 markus 567: }
568:
569: u_int
570: packet_get_encryption_key(u_char *key)
571: {
572: if (key == NULL)
1.161 andreas 573: return (active_state->ssh1_keylen);
574: memcpy(key, active_state->ssh1_key, active_state->ssh1_keylen);
575: return (active_state->ssh1_keylen);
1.1 deraadt 576: }
577:
1.62 markus 578: /* Start constructing a packet to send. */
1.2 provos 579: void
1.62 markus 580: packet_start(u_char type)
1.1 deraadt 581: {
1.62 markus 582: u_char buf[9];
583: int len;
1.1 deraadt 584:
1.62 markus 585: DBG(debug("packet_start[%d]", type));
586: len = compat20 ? 6 : 9;
587: memset(buf, 0, len - 1);
588: buf[len - 1] = type;
1.161 andreas 589: buffer_clear(&active_state->outgoing_packet);
590: buffer_append(&active_state->outgoing_packet, buf, len);
1.25 markus 591: }
592:
1.62 markus 593: /* Append payload. */
1.2 provos 594: void
595: packet_put_char(int value)
1.1 deraadt 596: {
1.14 markus 597: char ch = value;
1.97 deraadt 598:
1.161 andreas 599: buffer_append(&active_state->outgoing_packet, &ch, 1);
1.1 deraadt 600: }
1.125 deraadt 601:
1.2 provos 602: void
1.40 markus 603: packet_put_int(u_int value)
1.1 deraadt 604: {
1.161 andreas 605: buffer_put_int(&active_state->outgoing_packet, value);
1.1 deraadt 606: }
1.125 deraadt 607:
1.2 provos 608: void
1.162 andreas 609: packet_put_int64(u_int64_t value)
610: {
611: buffer_put_int64(&active_state->outgoing_packet, value);
612: }
613:
614: void
1.76 stevesk 615: packet_put_string(const void *buf, u_int len)
1.1 deraadt 616: {
1.161 andreas 617: buffer_put_string(&active_state->outgoing_packet, buf, len);
1.1 deraadt 618: }
1.125 deraadt 619:
1.24 markus 620: void
621: packet_put_cstring(const char *str)
622: {
1.161 andreas 623: buffer_put_cstring(&active_state->outgoing_packet, str);
1.24 markus 624: }
1.125 deraadt 625:
1.24 markus 626: void
1.76 stevesk 627: packet_put_raw(const void *buf, u_int len)
1.24 markus 628: {
1.161 andreas 629: buffer_append(&active_state->outgoing_packet, buf, len);
1.24 markus 630: }
1.125 deraadt 631:
1.195 markus 632: #ifdef WITH_OPENSSL
1.2 provos 633: void
1.14 markus 634: packet_put_bignum(BIGNUM * value)
1.1 deraadt 635: {
1.161 andreas 636: buffer_put_bignum(&active_state->outgoing_packet, value);
1.1 deraadt 637: }
1.125 deraadt 638:
1.24 markus 639: void
640: packet_put_bignum2(BIGNUM * value)
641: {
1.161 andreas 642: buffer_put_bignum2(&active_state->outgoing_packet, value);
1.24 markus 643: }
1.1 deraadt 644:
1.170 djm 645: void
646: packet_put_ecpoint(const EC_GROUP *curve, const EC_POINT *point)
647: {
648: buffer_put_ecpoint(&active_state->outgoing_packet, curve, point);
649: }
1.195 markus 650: #endif
1.170 djm 651:
1.16 markus 652: /*
653: * Finalizes and sends the packet. If the encryption key has been set,
654: * encrypts the packet before sending.
655: */
1.14 markus 656:
1.68 itojun 657: static void
1.49 itojun 658: packet_send1(void)
1.1 deraadt 659: {
1.89 markus 660: u_char buf[8], *cp;
1.14 markus 661: int i, padding, len;
1.40 markus 662: u_int checksum;
1.115 avsm 663: u_int32_t rnd = 0;
1.14 markus 664:
1.16 markus 665: /*
666: * If using packet compression, compress the payload of the outgoing
667: * packet.
668: */
1.161 andreas 669: if (active_state->packet_compression) {
670: buffer_clear(&active_state->compression_buffer);
1.14 markus 671: /* Skip padding. */
1.161 andreas 672: buffer_consume(&active_state->outgoing_packet, 8);
1.14 markus 673: /* padding */
1.161 andreas 674: buffer_append(&active_state->compression_buffer,
675: "\0\0\0\0\0\0\0\0", 8);
676: buffer_compress(&active_state->outgoing_packet,
677: &active_state->compression_buffer);
678: buffer_clear(&active_state->outgoing_packet);
679: buffer_append(&active_state->outgoing_packet,
680: buffer_ptr(&active_state->compression_buffer),
681: buffer_len(&active_state->compression_buffer));
1.14 markus 682: }
683: /* Compute packet length without padding (add checksum, remove padding). */
1.161 andreas 684: len = buffer_len(&active_state->outgoing_packet) + 4 - 8;
1.14 markus 685:
1.32 markus 686: /* Insert padding. Initialized to zero in packet_start1() */
1.14 markus 687: padding = 8 - len % 8;
1.161 andreas 688: if (!active_state->send_context.plaintext) {
689: cp = buffer_ptr(&active_state->outgoing_packet);
1.14 markus 690: for (i = 0; i < padding; i++) {
691: if (i % 4 == 0)
1.115 avsm 692: rnd = arc4random();
693: cp[7 - i] = rnd & 0xff;
694: rnd >>= 8;
1.14 markus 695: }
696: }
1.161 andreas 697: buffer_consume(&active_state->outgoing_packet, 8 - padding);
1.14 markus 698:
699: /* Add check bytes. */
1.161 andreas 700: checksum = ssh_crc32(buffer_ptr(&active_state->outgoing_packet),
701: buffer_len(&active_state->outgoing_packet));
1.131 djm 702: put_u32(buf, checksum);
1.161 andreas 703: buffer_append(&active_state->outgoing_packet, buf, 4);
1.1 deraadt 704:
705: #ifdef PACKET_DEBUG
1.14 markus 706: fprintf(stderr, "packet_send plain: ");
1.161 andreas 707: buffer_dump(&active_state->outgoing_packet);
1.1 deraadt 708: #endif
709:
1.14 markus 710: /* Append to output. */
1.131 djm 711: put_u32(buf, len);
1.161 andreas 712: buffer_append(&active_state->output, buf, 4);
713: cp = buffer_append_space(&active_state->output,
714: buffer_len(&active_state->outgoing_packet));
1.191 markus 715: if (cipher_crypt(&active_state->send_context, 0, cp,
1.161 andreas 716: buffer_ptr(&active_state->outgoing_packet),
1.191 markus 717: buffer_len(&active_state->outgoing_packet), 0, 0) != 0)
718: fatal("%s: cipher_crypt failed", __func__);
1.14 markus 719:
1.1 deraadt 720: #ifdef PACKET_DEBUG
1.14 markus 721: fprintf(stderr, "encrypted: ");
1.161 andreas 722: buffer_dump(&active_state->output);
1.1 deraadt 723: #endif
1.161 andreas 724: active_state->p_send.packets++;
725: active_state->p_send.bytes += len +
726: buffer_len(&active_state->outgoing_packet);
727: buffer_clear(&active_state->outgoing_packet);
1.1 deraadt 728:
1.16 markus 729: /*
1.120 djm 730: * Note that the packet is now only buffered in output. It won't be
1.16 markus 731: * actually sent until packet_write_wait or packet_write_poll is
732: * called.
733: */
1.1 deraadt 734: }
735:
1.91 markus 736: void
1.57 markus 737: set_newkeys(int mode)
738: {
739: Enc *enc;
740: Mac *mac;
741: Comp *comp;
742: CipherContext *cc;
1.105 markus 743: u_int64_t *max_blocks;
1.197 djm 744: int r, crypt_type;
1.57 markus 745:
1.100 markus 746: debug2("set_newkeys: mode %d", mode);
1.57 markus 747:
1.88 markus 748: if (mode == MODE_OUT) {
1.161 andreas 749: cc = &active_state->send_context;
1.115 avsm 750: crypt_type = CIPHER_ENCRYPT;
1.161 andreas 751: active_state->p_send.packets = active_state->p_send.blocks = 0;
752: max_blocks = &active_state->max_blocks_out;
1.88 markus 753: } else {
1.161 andreas 754: cc = &active_state->receive_context;
1.115 avsm 755: crypt_type = CIPHER_DECRYPT;
1.161 andreas 756: active_state->p_read.packets = active_state->p_read.blocks = 0;
757: max_blocks = &active_state->max_blocks_in;
1.88 markus 758: }
1.161 andreas 759: if (active_state->newkeys[mode] != NULL) {
1.100 markus 760: debug("set_newkeys: rekeying");
1.88 markus 761: cipher_cleanup(cc);
1.161 andreas 762: enc = &active_state->newkeys[mode]->enc;
763: mac = &active_state->newkeys[mode]->mac;
764: comp = &active_state->newkeys[mode]->comp;
1.148 pvalchev 765: mac_clear(mac);
1.192 djm 766: explicit_bzero(enc->iv, enc->iv_len);
767: explicit_bzero(enc->key, enc->key_len);
768: explicit_bzero(mac->key, mac->key_len);
1.186 djm 769: free(enc->name);
770: free(enc->iv);
771: free(enc->key);
772: free(mac->name);
773: free(mac->key);
774: free(comp->name);
775: free(active_state->newkeys[mode]);
1.57 markus 776: }
1.161 andreas 777: active_state->newkeys[mode] = kex_get_newkeys(mode);
778: if (active_state->newkeys[mode] == NULL)
1.57 markus 779: fatal("newkeys: no keys for mode %d", mode);
1.161 andreas 780: enc = &active_state->newkeys[mode]->enc;
781: mac = &active_state->newkeys[mode]->mac;
782: comp = &active_state->newkeys[mode]->comp;
1.180 markus 783: if (cipher_authlen(enc->cipher) == 0 && mac_init(mac) == 0)
1.57 markus 784: mac->enabled = 1;
785: DBG(debug("cipher_init_context: %d", mode));
1.197 djm 786: if ((r = cipher_init(cc, enc->cipher, enc->key, enc->key_len,
787: enc->iv, enc->iv_len, crypt_type)) != 0)
788: fatal("%s: cipher_init: %s", __func__, ssh_err(r));
1.91 markus 789: /* Deleting the keys does not gain extra security */
1.192 djm 790: /* explicit_bzero(enc->iv, enc->block_size);
791: explicit_bzero(enc->key, enc->key_len);
792: explicit_bzero(mac->key, mac->key_len); */
1.118 markus 793: if ((comp->type == COMP_ZLIB ||
1.161 andreas 794: (comp->type == COMP_DELAYED &&
795: active_state->after_authentication)) && comp->enabled == 0) {
1.60 markus 796: packet_init_compression();
797: if (mode == MODE_OUT)
798: buffer_compress_init_send(6);
799: else
800: buffer_compress_init_recv();
1.57 markus 801: comp->enabled = 1;
802: }
1.109 markus 803: /*
804: * The 2^(blocksize*2) limit is too expensive for 3DES,
805: * blowfish, etc, so enforce a 1GB limit for small blocksizes.
806: */
807: if (enc->block_size >= 16)
808: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
809: else
810: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.161 andreas 811: if (active_state->rekey_limit)
812: *max_blocks = MIN(*max_blocks,
813: active_state->rekey_limit / enc->block_size);
1.57 markus 814: }
815:
1.16 markus 816: /*
1.118 markus 817: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 818: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 819: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
820: */
821: static void
822: packet_enable_delayed_compress(void)
823: {
824: Comp *comp = NULL;
825: int mode;
826:
827: /*
828: * Remember that we are past the authentication step, so rekeying
829: * with COMP_DELAYED will turn on compression immediately.
830: */
1.161 andreas 831: active_state->after_authentication = 1;
1.118 markus 832: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 833: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.161 andreas 834: if (active_state->newkeys[mode] == NULL)
1.145 markus 835: continue;
1.161 andreas 836: comp = &active_state->newkeys[mode]->comp;
1.118 markus 837: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.119 markus 838: packet_init_compression();
1.118 markus 839: if (mode == MODE_OUT)
840: buffer_compress_init_send(6);
841: else
842: buffer_compress_init_recv();
843: comp->enabled = 1;
844: }
845: }
846: }
847:
848: /*
1.25 markus 849: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
850: */
1.68 itojun 851: static void
1.105 markus 852: packet_send2_wrapped(void)
1.25 markus 853: {
1.89 markus 854: u_char type, *cp, *macbuf = NULL;
1.178 markus 855: u_char padlen, pad = 0;
1.180 markus 856: u_int i, len, authlen = 0, aadlen = 0;
1.115 avsm 857: u_int32_t rnd = 0;
1.25 markus 858: Enc *enc = NULL;
859: Mac *mac = NULL;
860: Comp *comp = NULL;
861: int block_size;
862:
1.161 andreas 863: if (active_state->newkeys[MODE_OUT] != NULL) {
864: enc = &active_state->newkeys[MODE_OUT]->enc;
865: mac = &active_state->newkeys[MODE_OUT]->mac;
866: comp = &active_state->newkeys[MODE_OUT]->comp;
1.180 markus 867: /* disable mac for authenticated encryption */
868: if ((authlen = cipher_authlen(enc->cipher)) != 0)
869: mac = NULL;
1.25 markus 870: }
1.88 markus 871: block_size = enc ? enc->block_size : 8;
1.180 markus 872: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 873:
1.161 andreas 874: cp = buffer_ptr(&active_state->outgoing_packet);
1.89 markus 875: type = cp[5];
1.25 markus 876:
877: #ifdef PACKET_DEBUG
878: fprintf(stderr, "plain: ");
1.161 andreas 879: buffer_dump(&active_state->outgoing_packet);
1.25 markus 880: #endif
881:
882: if (comp && comp->enabled) {
1.161 andreas 883: len = buffer_len(&active_state->outgoing_packet);
1.25 markus 884: /* skip header, compress only payload */
1.161 andreas 885: buffer_consume(&active_state->outgoing_packet, 5);
886: buffer_clear(&active_state->compression_buffer);
887: buffer_compress(&active_state->outgoing_packet,
888: &active_state->compression_buffer);
889: buffer_clear(&active_state->outgoing_packet);
890: buffer_append(&active_state->outgoing_packet, "\0\0\0\0\0", 5);
891: buffer_append(&active_state->outgoing_packet,
892: buffer_ptr(&active_state->compression_buffer),
893: buffer_len(&active_state->compression_buffer));
1.25 markus 894: DBG(debug("compression: raw %d compressed %d", len,
1.161 andreas 895: buffer_len(&active_state->outgoing_packet)));
1.25 markus 896: }
897:
898: /* sizeof (packet_len + pad_len + payload) */
1.161 andreas 899: len = buffer_len(&active_state->outgoing_packet);
1.25 markus 900:
901: /*
902: * calc size of padding, alloc space, get random data,
903: * minimum padding is 4 bytes
904: */
1.178 markus 905: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 906: padlen = block_size - (len % block_size);
907: if (padlen < 4)
908: padlen += block_size;
1.161 andreas 909: if (active_state->extra_pad) {
1.71 markus 910: /* will wrap if extra_pad+padlen > 255 */
1.161 andreas 911: active_state->extra_pad =
912: roundup(active_state->extra_pad, block_size);
913: pad = active_state->extra_pad -
914: ((len + padlen) % active_state->extra_pad);
1.193 djm 915: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
916: __func__, pad, len, padlen, active_state->extra_pad));
1.71 markus 917: padlen += pad;
1.161 andreas 918: active_state->extra_pad = 0;
1.71 markus 919: }
1.161 andreas 920: cp = buffer_append_space(&active_state->outgoing_packet, padlen);
921: if (enc && !active_state->send_context.plaintext) {
1.32 markus 922: /* random padding */
1.25 markus 923: for (i = 0; i < padlen; i++) {
924: if (i % 4 == 0)
1.115 avsm 925: rnd = arc4random();
926: cp[i] = rnd & 0xff;
927: rnd >>= 8;
1.25 markus 928: }
1.32 markus 929: } else {
930: /* clear padding */
1.192 djm 931: explicit_bzero(cp, padlen);
1.25 markus 932: }
1.178 markus 933: /* sizeof (packet_len + pad_len + payload + padding) */
934: len = buffer_len(&active_state->outgoing_packet);
935: cp = buffer_ptr(&active_state->outgoing_packet);
1.25 markus 936: /* packet_length includes payload, padding and padding length field */
1.178 markus 937: put_u32(cp, len - 4);
1.89 markus 938: cp[4] = padlen;
1.178 markus 939: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
940: len, padlen, aadlen));
1.25 markus 941:
942: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 943: if (mac && mac->enabled && !mac->etm) {
1.161 andreas 944: macbuf = mac_compute(mac, active_state->p_send.seqnr,
1.178 markus 945: buffer_ptr(&active_state->outgoing_packet), len);
1.161 andreas 946: DBG(debug("done calc MAC out #%d", active_state->p_send.seqnr));
1.25 markus 947: }
948: /* encrypt packet and append to output buffer. */
1.180 markus 949: cp = buffer_append_space(&active_state->output, len + authlen);
1.191 markus 950: if (cipher_crypt(&active_state->send_context, active_state->p_send.seqnr,
1.190 djm 951: cp, buffer_ptr(&active_state->outgoing_packet),
1.191 markus 952: len - aadlen, aadlen, authlen) != 0)
953: fatal("%s: cipher_crypt failed", __func__);
1.25 markus 954: /* append unencrypted MAC */
1.178 markus 955: if (mac && mac->enabled) {
956: if (mac->etm) {
957: /* EtM: compute mac over aadlen + cipher text */
958: macbuf = mac_compute(mac,
959: active_state->p_send.seqnr, cp, len);
960: DBG(debug("done calc MAC(EtM) out #%d",
961: active_state->p_send.seqnr));
962: }
1.161 andreas 963: buffer_append(&active_state->output, macbuf, mac->mac_len);
1.178 markus 964: }
1.25 markus 965: #ifdef PACKET_DEBUG
966: fprintf(stderr, "encrypted: ");
1.161 andreas 967: buffer_dump(&active_state->output);
1.25 markus 968: #endif
1.29 markus 969: /* increment sequence number for outgoing packets */
1.161 andreas 970: if (++active_state->p_send.seqnr == 0)
1.106 itojun 971: logit("outgoing seqnr wraps around");
1.161 andreas 972: if (++active_state->p_send.packets == 0)
1.105 markus 973: if (!(datafellows & SSH_BUG_NOREKEY))
974: fatal("XXX too many packets with same key");
1.178 markus 975: active_state->p_send.blocks += len / block_size;
976: active_state->p_send.bytes += len;
1.161 andreas 977: buffer_clear(&active_state->outgoing_packet);
1.25 markus 978:
1.57 markus 979: if (type == SSH2_MSG_NEWKEYS)
980: set_newkeys(MODE_OUT);
1.161 andreas 981: else if (type == SSH2_MSG_USERAUTH_SUCCESS && active_state->server_side)
1.118 markus 982: packet_enable_delayed_compress();
1.25 markus 983: }
984:
1.105 markus 985: static void
986: packet_send2(void)
987: {
988: struct packet *p;
989: u_char type, *cp;
990:
1.161 andreas 991: cp = buffer_ptr(&active_state->outgoing_packet);
1.105 markus 992: type = cp[5];
993:
994: /* during rekeying we can only send key exchange messages */
1.165 andreas 995: if (active_state->rekeying) {
1.175 markus 996: if ((type < SSH2_MSG_TRANSPORT_MIN) ||
997: (type > SSH2_MSG_TRANSPORT_MAX) ||
998: (type == SSH2_MSG_SERVICE_REQUEST) ||
999: (type == SSH2_MSG_SERVICE_ACCEPT)) {
1.105 markus 1000: debug("enqueue packet: %u", type);
1.189 djm 1001: p = xcalloc(1, sizeof(*p));
1.105 markus 1002: p->type = type;
1.161 andreas 1003: memcpy(&p->payload, &active_state->outgoing_packet,
1004: sizeof(Buffer));
1005: buffer_init(&active_state->outgoing_packet);
1006: TAILQ_INSERT_TAIL(&active_state->outgoing, p, next);
1.105 markus 1007: return;
1008: }
1009: }
1010:
1011: /* rekeying starts with sending KEXINIT */
1012: if (type == SSH2_MSG_KEXINIT)
1.165 andreas 1013: active_state->rekeying = 1;
1.105 markus 1014:
1015: packet_send2_wrapped();
1016:
1017: /* after a NEWKEYS message we can send the complete queue */
1018: if (type == SSH2_MSG_NEWKEYS) {
1.165 andreas 1019: active_state->rekeying = 0;
1.187 dtucker 1020: active_state->rekey_time = monotime();
1.161 andreas 1021: while ((p = TAILQ_FIRST(&active_state->outgoing))) {
1.105 markus 1022: type = p->type;
1023: debug("dequeue packet: %u", type);
1.161 andreas 1024: buffer_free(&active_state->outgoing_packet);
1025: memcpy(&active_state->outgoing_packet, &p->payload,
1.105 markus 1026: sizeof(Buffer));
1.161 andreas 1027: TAILQ_REMOVE(&active_state->outgoing, p, next);
1.186 djm 1028: free(p);
1.105 markus 1029: packet_send2_wrapped();
1030: }
1031: }
1032: }
1033:
1.25 markus 1034: void
1.73 itojun 1035: packet_send(void)
1.25 markus 1036: {
1.62 markus 1037: if (compat20)
1.25 markus 1038: packet_send2();
1039: else
1040: packet_send1();
1041: DBG(debug("packet_send done"));
1042: }
1043:
1044: /*
1.16 markus 1045: * Waits until a packet has been received, and returns its type. Note that
1046: * no other data is processed until this returns, so this function should not
1047: * be used during the interactive session.
1048: */
1.1 deraadt 1049:
1.2 provos 1050: int
1.82 markus 1051: packet_read_seqnr(u_int32_t *seqnr_p)
1.1 deraadt 1052: {
1.188 djm 1053: int type, len, ret, cont, ms_remain = 0;
1.56 millert 1054: fd_set *setp;
1.14 markus 1055: char buf[8192];
1.155 deraadt 1056: struct timeval timeout, start, *timeoutp = NULL;
1057:
1.25 markus 1058: DBG(debug("packet_read()"));
1.14 markus 1059:
1.161 andreas 1060: setp = (fd_set *)xcalloc(howmany(active_state->connection_in + 1,
1061: NFDBITS), sizeof(fd_mask));
1.56 millert 1062:
1.14 markus 1063: /* Since we are blocking, ensure that all written packets have been sent. */
1064: packet_write_wait();
1065:
1066: /* Stay in the loop until we have received a complete packet. */
1067: for (;;) {
1068: /* Try to read a packet from the buffer. */
1.82 markus 1069: type = packet_read_poll_seqnr(seqnr_p);
1.62 markus 1070: if (!compat20 && (
1.32 markus 1071: type == SSH_SMSG_SUCCESS
1.14 markus 1072: || type == SSH_SMSG_FAILURE
1073: || type == SSH_CMSG_EOF
1.32 markus 1074: || type == SSH_CMSG_EXIT_CONFIRMATION))
1.79 markus 1075: packet_check_eom();
1.14 markus 1076: /* If we got a packet, return it. */
1.56 millert 1077: if (type != SSH_MSG_NONE) {
1.186 djm 1078: free(setp);
1.14 markus 1079: return type;
1.56 millert 1080: }
1.16 markus 1081: /*
1082: * Otherwise, wait for some data to arrive, add it to the
1083: * buffer, and try again.
1084: */
1.161 andreas 1085: memset(setp, 0, howmany(active_state->connection_in + 1,
1086: NFDBITS) * sizeof(fd_mask));
1087: FD_SET(active_state->connection_in, setp);
1.16 markus 1088:
1.161 andreas 1089: if (active_state->packet_timeout_ms > 0) {
1090: ms_remain = active_state->packet_timeout_ms;
1.154 dtucker 1091: timeoutp = &timeout;
1092: }
1.14 markus 1093: /* Wait for some data to arrive. */
1.154 dtucker 1094: for (;;) {
1.161 andreas 1095: if (active_state->packet_timeout_ms != -1) {
1.154 dtucker 1096: ms_to_timeval(&timeout, ms_remain);
1097: gettimeofday(&start, NULL);
1098: }
1.161 andreas 1099: if ((ret = select(active_state->connection_in + 1, setp,
1100: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1101: break;
1.161 andreas 1102: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1103: break;
1.161 andreas 1104: if (active_state->packet_timeout_ms == -1)
1.154 dtucker 1105: continue;
1106: ms_subtract_diff(&start, &ms_remain);
1107: if (ms_remain <= 0) {
1108: ret = 0;
1109: break;
1110: }
1111: }
1112: if (ret == 0) {
1113: logit("Connection to %.200s timed out while "
1114: "waiting to read", get_remote_ipaddr());
1115: cleanup_exit(255);
1116: }
1.14 markus 1117: /* Read data from the socket. */
1.163 andreas 1118: do {
1119: cont = 0;
1120: len = roaming_read(active_state->connection_in, buf,
1121: sizeof(buf), &cont);
1122: } while (len == 0 && cont);
1.18 markus 1123: if (len == 0) {
1.106 itojun 1124: logit("Connection closed by %.200s", get_remote_ipaddr());
1.112 markus 1125: cleanup_exit(255);
1.18 markus 1126: }
1.14 markus 1127: if (len < 0)
1128: fatal("Read from socket failed: %.100s", strerror(errno));
1129: /* Append it to the buffer. */
1130: packet_process_incoming(buf, len);
1131: }
1132: /* NOTREACHED */
1.1 deraadt 1133: }
1134:
1.77 djm 1135: int
1.82 markus 1136: packet_read(void)
1.77 djm 1137: {
1.82 markus 1138: return packet_read_seqnr(NULL);
1.77 djm 1139: }
1140:
1.16 markus 1141: /*
1142: * Waits until a packet has been received, verifies that its type matches
1143: * that given, and gives a fatal error and exits if there is a mismatch.
1144: */
1.1 deraadt 1145:
1.2 provos 1146: void
1.82 markus 1147: packet_read_expect(int expected_type)
1.1 deraadt 1148: {
1.14 markus 1149: int type;
1.1 deraadt 1150:
1.82 markus 1151: type = packet_read();
1.14 markus 1152: if (type != expected_type)
1153: packet_disconnect("Protocol error: expected packet type %d, got %d",
1.25 markus 1154: expected_type, type);
1.1 deraadt 1155: }
1156:
1157: /* Checks if a full packet is available in the data received so far via
1.14 markus 1158: * packet_process_incoming. If so, reads the packet; otherwise returns
1159: * SSH_MSG_NONE. This does not wait for data from the connection.
1160: *
1.150 dtucker 1161: * SSH_MSG_DISCONNECT is handled specially here. Also,
1162: * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1163: * to higher levels.
1.14 markus 1164: */
1.1 deraadt 1165:
1.68 itojun 1166: static int
1.82 markus 1167: packet_read_poll1(void)
1.1 deraadt 1168: {
1.40 markus 1169: u_int len, padded_len;
1.89 markus 1170: u_char *cp, type;
1.40 markus 1171: u_int checksum, stored_checksum;
1.14 markus 1172:
1173: /* Check if input size is less than minimum packet size. */
1.161 andreas 1174: if (buffer_len(&active_state->input) < 4 + 8)
1.14 markus 1175: return SSH_MSG_NONE;
1176: /* Get length of incoming packet. */
1.161 andreas 1177: cp = buffer_ptr(&active_state->input);
1.131 djm 1178: len = get_u32(cp);
1.14 markus 1179: if (len < 1 + 2 + 2 || len > 256 * 1024)
1.98 markus 1180: packet_disconnect("Bad packet length %u.", len);
1.14 markus 1181: padded_len = (len + 8) & ~7;
1182:
1183: /* Check if the packet has been entirely received. */
1.161 andreas 1184: if (buffer_len(&active_state->input) < 4 + padded_len)
1.14 markus 1185: return SSH_MSG_NONE;
1186:
1187: /* The entire packet is in buffer. */
1188:
1189: /* Consume packet length. */
1.161 andreas 1190: buffer_consume(&active_state->input, 4);
1.14 markus 1191:
1.62 markus 1192: /*
1193: * Cryptographic attack detector for ssh
1194: * (C)1998 CORE-SDI, Buenos Aires Argentina
1195: * Ariel Futoransky(futo@core-sdi.com)
1196: */
1.161 andreas 1197: if (!active_state->receive_context.plaintext) {
1198: switch (detect_attack(buffer_ptr(&active_state->input),
1199: padded_len)) {
1.144 djm 1200: case DEATTACK_DETECTED:
1201: packet_disconnect("crc32 compensation attack: "
1202: "network attack detected");
1203: case DEATTACK_DOS_DETECTED:
1204: packet_disconnect("deattack denial of "
1205: "service detected");
1206: }
1207: }
1.62 markus 1208:
1209: /* Decrypt data to incoming_packet. */
1.161 andreas 1210: buffer_clear(&active_state->incoming_packet);
1211: cp = buffer_append_space(&active_state->incoming_packet, padded_len);
1.191 markus 1212: if (cipher_crypt(&active_state->receive_context, 0, cp,
1213: buffer_ptr(&active_state->input), padded_len, 0, 0) != 0)
1214: fatal("%s: cipher_crypt failed", __func__);
1.62 markus 1215:
1.161 andreas 1216: buffer_consume(&active_state->input, padded_len);
1.1 deraadt 1217:
1218: #ifdef PACKET_DEBUG
1.14 markus 1219: fprintf(stderr, "read_poll plain: ");
1.161 andreas 1220: buffer_dump(&active_state->incoming_packet);
1.1 deraadt 1221: #endif
1222:
1.14 markus 1223: /* Compute packet checksum. */
1.161 andreas 1224: checksum = ssh_crc32(buffer_ptr(&active_state->incoming_packet),
1225: buffer_len(&active_state->incoming_packet) - 4);
1.14 markus 1226:
1227: /* Skip padding. */
1.161 andreas 1228: buffer_consume(&active_state->incoming_packet, 8 - len % 8);
1.14 markus 1229:
1230: /* Test check bytes. */
1.161 andreas 1231: if (len != buffer_len(&active_state->incoming_packet))
1.77 djm 1232: packet_disconnect("packet_read_poll1: len %d != buffer_len %d.",
1.161 andreas 1233: len, buffer_len(&active_state->incoming_packet));
1.14 markus 1234:
1.161 andreas 1235: cp = (u_char *)buffer_ptr(&active_state->incoming_packet) + len - 4;
1.131 djm 1236: stored_checksum = get_u32(cp);
1.14 markus 1237: if (checksum != stored_checksum)
1238: packet_disconnect("Corrupted check bytes on input.");
1.161 andreas 1239: buffer_consume_end(&active_state->incoming_packet, 4);
1.14 markus 1240:
1.161 andreas 1241: if (active_state->packet_compression) {
1242: buffer_clear(&active_state->compression_buffer);
1243: buffer_uncompress(&active_state->incoming_packet,
1244: &active_state->compression_buffer);
1245: buffer_clear(&active_state->incoming_packet);
1246: buffer_append(&active_state->incoming_packet,
1247: buffer_ptr(&active_state->compression_buffer),
1248: buffer_len(&active_state->compression_buffer));
1249: }
1250: active_state->p_read.packets++;
1251: active_state->p_read.bytes += padded_len + 4;
1252: type = buffer_get_char(&active_state->incoming_packet);
1.116 markus 1253: if (type < SSH_MSG_MIN || type > SSH_MSG_MAX)
1254: packet_disconnect("Invalid ssh1 packet type: %d", type);
1.62 markus 1255: return type;
1.1 deraadt 1256: }
1.14 markus 1257:
1.68 itojun 1258: static int
1.82 markus 1259: packet_read_poll2(u_int32_t *seqnr_p)
1.25 markus 1260: {
1.40 markus 1261: u_int padlen, need;
1.178 markus 1262: u_char *macbuf = NULL, *cp, type;
1.180 markus 1263: u_int maclen, authlen = 0, aadlen = 0, block_size;
1.25 markus 1264: Enc *enc = NULL;
1265: Mac *mac = NULL;
1266: Comp *comp = NULL;
1267:
1.161 andreas 1268: if (active_state->packet_discard)
1.159 markus 1269: return SSH_MSG_NONE;
1270:
1.161 andreas 1271: if (active_state->newkeys[MODE_IN] != NULL) {
1272: enc = &active_state->newkeys[MODE_IN]->enc;
1273: mac = &active_state->newkeys[MODE_IN]->mac;
1274: comp = &active_state->newkeys[MODE_IN]->comp;
1.180 markus 1275: /* disable mac for authenticated encryption */
1276: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1277: mac = NULL;
1.25 markus 1278: }
1279: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1280: block_size = enc ? enc->block_size : 8;
1.180 markus 1281: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1282:
1.178 markus 1283: if (aadlen && active_state->packlen == 0) {
1.190 djm 1284: if (cipher_get_length(&active_state->receive_context,
1285: &active_state->packlen,
1286: active_state->p_read.seqnr,
1287: buffer_ptr(&active_state->input),
1288: buffer_len(&active_state->input)) != 0)
1.178 markus 1289: return SSH_MSG_NONE;
1290: if (active_state->packlen < 1 + 4 ||
1291: active_state->packlen > PACKET_MAX_SIZE) {
1292: #ifdef PACKET_DEBUG
1293: buffer_dump(&active_state->input);
1294: #endif
1295: logit("Bad packet length %u.", active_state->packlen);
1296: packet_disconnect("Packet corrupt");
1297: }
1.179 markus 1298: buffer_clear(&active_state->incoming_packet);
1.178 markus 1299: } else if (active_state->packlen == 0) {
1.25 markus 1300: /*
1301: * check if input size is less than the cipher block size,
1302: * decrypt first block and extract length of incoming packet
1303: */
1.161 andreas 1304: if (buffer_len(&active_state->input) < block_size)
1.25 markus 1305: return SSH_MSG_NONE;
1.161 andreas 1306: buffer_clear(&active_state->incoming_packet);
1307: cp = buffer_append_space(&active_state->incoming_packet,
1.25 markus 1308: block_size);
1.191 markus 1309: if (cipher_crypt(&active_state->receive_context,
1.190 djm 1310: active_state->p_read.seqnr, cp,
1.191 markus 1311: buffer_ptr(&active_state->input), block_size, 0, 0) != 0)
1312: fatal("Decryption integrity check failed");
1.161 andreas 1313: cp = buffer_ptr(&active_state->incoming_packet);
1314: active_state->packlen = get_u32(cp);
1315: if (active_state->packlen < 1 + 4 ||
1316: active_state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1317: #ifdef PACKET_DEBUG
1.161 andreas 1318: buffer_dump(&active_state->incoming_packet);
1.110 markus 1319: #endif
1.161 andreas 1320: logit("Bad packet length %u.", active_state->packlen);
1321: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1322: PACKET_MAX_SIZE);
1323: return SSH_MSG_NONE;
1.25 markus 1324: }
1.161 andreas 1325: buffer_consume(&active_state->input, block_size);
1.25 markus 1326: }
1.178 markus 1327: DBG(debug("input: packet len %u", active_state->packlen+4));
1328: if (aadlen) {
1329: /* only the payload is encrypted */
1330: need = active_state->packlen;
1331: } else {
1332: /*
1333: * the payload size and the payload are encrypted, but we
1334: * have a partial packet of block_size bytes
1335: */
1336: need = 4 + active_state->packlen - block_size;
1337: }
1.180 markus 1338: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1339: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1340: if (need % block_size != 0) {
1341: logit("padding error: need %d block %d mod %d",
1.25 markus 1342: need, block_size, need % block_size);
1.161 andreas 1343: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1344: PACKET_MAX_SIZE - block_size);
1345: return SSH_MSG_NONE;
1.158 markus 1346: }
1.25 markus 1347: /*
1348: * check if the entire packet has been received and
1.178 markus 1349: * decrypt into incoming_packet:
1350: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1351: * 'need' bytes are encrypted, followed by either
1352: * 'authlen' bytes of authentication tag or
1.178 markus 1353: * 'maclen' bytes of message authentication code.
1.25 markus 1354: */
1.180 markus 1355: if (buffer_len(&active_state->input) < aadlen + need + authlen + maclen)
1.25 markus 1356: return SSH_MSG_NONE;
1357: #ifdef PACKET_DEBUG
1358: fprintf(stderr, "read_poll enc/full: ");
1.161 andreas 1359: buffer_dump(&active_state->input);
1.25 markus 1360: #endif
1.178 markus 1361: /* EtM: compute mac over encrypted input */
1362: if (mac && mac->enabled && mac->etm)
1363: macbuf = mac_compute(mac, active_state->p_read.seqnr,
1364: buffer_ptr(&active_state->input), aadlen + need);
1365: cp = buffer_append_space(&active_state->incoming_packet, aadlen + need);
1.191 markus 1366: if (cipher_crypt(&active_state->receive_context,
1.190 djm 1367: active_state->p_read.seqnr, cp,
1.191 markus 1368: buffer_ptr(&active_state->input), need, aadlen, authlen) != 0)
1369: fatal("Decryption integrity check failed");
1.180 markus 1370: buffer_consume(&active_state->input, aadlen + need + authlen);
1.25 markus 1371: /*
1372: * compute MAC over seqnr and packet,
1373: * increment sequence number for incoming packet
1374: */
1.29 markus 1375: if (mac && mac->enabled) {
1.178 markus 1376: if (!mac->etm)
1377: macbuf = mac_compute(mac, active_state->p_read.seqnr,
1378: buffer_ptr(&active_state->incoming_packet),
1379: buffer_len(&active_state->incoming_packet));
1.168 djm 1380: if (timingsafe_bcmp(macbuf, buffer_ptr(&active_state->input),
1.161 andreas 1381: mac->mac_len) != 0) {
1.159 markus 1382: logit("Corrupted MAC on input.");
1383: if (need > PACKET_MAX_SIZE)
1384: fatal("internal error need %d", need);
1.161 andreas 1385: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1386: PACKET_MAX_SIZE - need);
1387: return SSH_MSG_NONE;
1388: }
1389:
1.161 andreas 1390: DBG(debug("MAC #%d ok", active_state->p_read.seqnr));
1391: buffer_consume(&active_state->input, mac->mac_len);
1.25 markus 1392: }
1.159 markus 1393: /* XXX now it's safe to use fatal/packet_disconnect */
1.77 djm 1394: if (seqnr_p != NULL)
1.161 andreas 1395: *seqnr_p = active_state->p_read.seqnr;
1396: if (++active_state->p_read.seqnr == 0)
1.106 itojun 1397: logit("incoming seqnr wraps around");
1.161 andreas 1398: if (++active_state->p_read.packets == 0)
1.105 markus 1399: if (!(datafellows & SSH_BUG_NOREKEY))
1400: fatal("XXX too many packets with same key");
1.161 andreas 1401: active_state->p_read.blocks += (active_state->packlen + 4) / block_size;
1402: active_state->p_read.bytes += active_state->packlen + 4;
1.25 markus 1403:
1404: /* get padlen */
1.161 andreas 1405: cp = buffer_ptr(&active_state->incoming_packet);
1.89 markus 1406: padlen = cp[4];
1.25 markus 1407: DBG(debug("input: padlen %d", padlen));
1408: if (padlen < 4)
1409: packet_disconnect("Corrupted padlen %d on input.", padlen);
1410:
1411: /* skip packet size + padlen, discard padding */
1.161 andreas 1412: buffer_consume(&active_state->incoming_packet, 4 + 1);
1413: buffer_consume_end(&active_state->incoming_packet, padlen);
1.25 markus 1414:
1.161 andreas 1415: DBG(debug("input: len before de-compress %d",
1416: buffer_len(&active_state->incoming_packet)));
1.25 markus 1417: if (comp && comp->enabled) {
1.161 andreas 1418: buffer_clear(&active_state->compression_buffer);
1419: buffer_uncompress(&active_state->incoming_packet,
1420: &active_state->compression_buffer);
1421: buffer_clear(&active_state->incoming_packet);
1422: buffer_append(&active_state->incoming_packet,
1423: buffer_ptr(&active_state->compression_buffer),
1424: buffer_len(&active_state->compression_buffer));
1.97 deraadt 1425: DBG(debug("input: len after de-compress %d",
1.161 andreas 1426: buffer_len(&active_state->incoming_packet)));
1.25 markus 1427: }
1428: /*
1429: * get packet type, implies consume.
1430: * return length of payload (without type field)
1431: */
1.161 andreas 1432: type = buffer_get_char(&active_state->incoming_packet);
1.116 markus 1433: if (type < SSH2_MSG_MIN || type >= SSH2_MSG_LOCAL_MIN)
1434: packet_disconnect("Invalid ssh2 packet type: %d", type);
1.57 markus 1435: if (type == SSH2_MSG_NEWKEYS)
1436: set_newkeys(MODE_IN);
1.161 andreas 1437: else if (type == SSH2_MSG_USERAUTH_SUCCESS &&
1438: !active_state->server_side)
1.118 markus 1439: packet_enable_delayed_compress();
1.25 markus 1440: #ifdef PACKET_DEBUG
1.55 deraadt 1441: fprintf(stderr, "read/plain[%d]:\r\n", type);
1.161 andreas 1442: buffer_dump(&active_state->incoming_packet);
1.25 markus 1443: #endif
1.62 markus 1444: /* reset for next packet */
1.161 andreas 1445: active_state->packlen = 0;
1.62 markus 1446: return type;
1.25 markus 1447: }
1448:
1449: int
1.82 markus 1450: packet_read_poll_seqnr(u_int32_t *seqnr_p)
1.25 markus 1451: {
1.96 deraadt 1452: u_int reason, seqnr;
1.62 markus 1453: u_char type;
1.25 markus 1454: char *msg;
1.62 markus 1455:
1.25 markus 1456: for (;;) {
1.62 markus 1457: if (compat20) {
1.82 markus 1458: type = packet_read_poll2(seqnr_p);
1.153 djm 1459: if (type) {
1.161 andreas 1460: active_state->keep_alive_timeouts = 0;
1.25 markus 1461: DBG(debug("received packet type %d", type));
1.153 djm 1462: }
1.74 deraadt 1463: switch (type) {
1.150 dtucker 1464: case SSH2_MSG_IGNORE:
1.151 dtucker 1465: debug3("Received SSH2_MSG_IGNORE");
1.150 dtucker 1466: break;
1.25 markus 1467: case SSH2_MSG_DEBUG:
1468: packet_get_char();
1469: msg = packet_get_string(NULL);
1470: debug("Remote: %.900s", msg);
1.186 djm 1471: free(msg);
1.25 markus 1472: msg = packet_get_string(NULL);
1.186 djm 1473: free(msg);
1.25 markus 1474: break;
1475: case SSH2_MSG_DISCONNECT:
1476: reason = packet_get_int();
1477: msg = packet_get_string(NULL);
1.182 djm 1478: /* Ignore normal client exit notifications */
1479: do_log2(active_state->server_side &&
1480: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1481: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1482: "Received disconnect from %s: %u: %.400s",
1.96 deraadt 1483: get_remote_ipaddr(), reason, msg);
1.186 djm 1484: free(msg);
1.112 markus 1485: cleanup_exit(255);
1.84 markus 1486: break;
1487: case SSH2_MSG_UNIMPLEMENTED:
1488: seqnr = packet_get_int();
1.96 deraadt 1489: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1490: seqnr);
1.150 dtucker 1491: break;
1.25 markus 1492: default:
1493: return type;
1.48 stevesk 1494: }
1.25 markus 1495: } else {
1.82 markus 1496: type = packet_read_poll1();
1.74 deraadt 1497: switch (type) {
1.188 djm 1498: case SSH_MSG_NONE:
1499: return SSH_MSG_NONE;
1.25 markus 1500: case SSH_MSG_IGNORE:
1501: break;
1502: case SSH_MSG_DEBUG:
1503: msg = packet_get_string(NULL);
1504: debug("Remote: %.900s", msg);
1.186 djm 1505: free(msg);
1.25 markus 1506: break;
1507: case SSH_MSG_DISCONNECT:
1508: msg = packet_get_string(NULL);
1.181 djm 1509: error("Received disconnect from %s: %.400s",
1.96 deraadt 1510: get_remote_ipaddr(), msg);
1.112 markus 1511: cleanup_exit(255);
1.25 markus 1512: break;
1513: default:
1.188 djm 1514: DBG(debug("received packet type %d", type));
1.25 markus 1515: return type;
1.48 stevesk 1516: }
1.25 markus 1517: }
1518: }
1519: }
1520:
1.16 markus 1521: /*
1522: * Buffers the given amount of input characters. This is intended to be used
1523: * together with packet_read_poll.
1524: */
1.1 deraadt 1525:
1.2 provos 1526: void
1.40 markus 1527: packet_process_incoming(const char *buf, u_int len)
1.1 deraadt 1528: {
1.161 andreas 1529: if (active_state->packet_discard) {
1530: active_state->keep_alive_timeouts = 0; /* ?? */
1531: if (len >= active_state->packet_discard)
1.159 markus 1532: packet_stop_discard();
1.161 andreas 1533: active_state->packet_discard -= len;
1.159 markus 1534: return;
1535: }
1.161 andreas 1536: buffer_append(&active_state->input, buf, len);
1.1 deraadt 1537: }
1538:
1539: /* Returns a character from the packet. */
1540:
1.40 markus 1541: u_int
1.73 itojun 1542: packet_get_char(void)
1.1 deraadt 1543: {
1.14 markus 1544: char ch;
1.97 deraadt 1545:
1.161 andreas 1546: buffer_get(&active_state->incoming_packet, &ch, 1);
1.40 markus 1547: return (u_char) ch;
1.1 deraadt 1548: }
1549:
1550: /* Returns an integer from the packet data. */
1551:
1.40 markus 1552: u_int
1.73 itojun 1553: packet_get_int(void)
1.1 deraadt 1554: {
1.161 andreas 1555: return buffer_get_int(&active_state->incoming_packet);
1.162 andreas 1556: }
1557:
1558: /* Returns an 64 bit integer from the packet data. */
1559:
1560: u_int64_t
1561: packet_get_int64(void)
1562: {
1563: return buffer_get_int64(&active_state->incoming_packet);
1.1 deraadt 1564: }
1565:
1.16 markus 1566: /*
1567: * Returns an arbitrary precision integer from the packet data. The integer
1568: * must have been initialized before this call.
1569: */
1.1 deraadt 1570:
1.195 markus 1571: #ifdef WITH_OPENSSL
1.2 provos 1572: void
1.80 markus 1573: packet_get_bignum(BIGNUM * value)
1.1 deraadt 1574: {
1.161 andreas 1575: buffer_get_bignum(&active_state->incoming_packet, value);
1.24 markus 1576: }
1577:
1578: void
1.80 markus 1579: packet_get_bignum2(BIGNUM * value)
1.24 markus 1580: {
1.161 andreas 1581: buffer_get_bignum2(&active_state->incoming_packet, value);
1.170 djm 1582: }
1583:
1584: void
1585: packet_get_ecpoint(const EC_GROUP *curve, EC_POINT *point)
1586: {
1587: buffer_get_ecpoint(&active_state->incoming_packet, curve, point);
1.24 markus 1588: }
1.195 markus 1589: #endif
1.24 markus 1590:
1.76 stevesk 1591: void *
1.117 djm 1592: packet_get_raw(u_int *length_ptr)
1.24 markus 1593: {
1.161 andreas 1594: u_int bytes = buffer_len(&active_state->incoming_packet);
1.97 deraadt 1595:
1.24 markus 1596: if (length_ptr != NULL)
1597: *length_ptr = bytes;
1.161 andreas 1598: return buffer_ptr(&active_state->incoming_packet);
1.28 markus 1599: }
1600:
1601: int
1602: packet_remaining(void)
1603: {
1.161 andreas 1604: return buffer_len(&active_state->incoming_packet);
1.1 deraadt 1605: }
1606:
1.16 markus 1607: /*
1608: * Returns a string from the packet data. The string is allocated using
1609: * xmalloc; it is the responsibility of the calling program to free it when
1610: * no longer needed. The length_ptr argument may be NULL, or point to an
1611: * integer into which the length of the string is stored.
1612: */
1.1 deraadt 1613:
1.76 stevesk 1614: void *
1.40 markus 1615: packet_get_string(u_int *length_ptr)
1.1 deraadt 1616: {
1.161 andreas 1617: return buffer_get_string(&active_state->incoming_packet, length_ptr);
1.152 markus 1618: }
1619:
1.194 djm 1620: const void *
1.152 markus 1621: packet_get_string_ptr(u_int *length_ptr)
1622: {
1.161 andreas 1623: return buffer_get_string_ptr(&active_state->incoming_packet, length_ptr);
1.169 djm 1624: }
1625:
1626: /* Ensures the returned string has no embedded \0 characters in it. */
1627: char *
1628: packet_get_cstring(u_int *length_ptr)
1629: {
1630: return buffer_get_cstring(&active_state->incoming_packet, length_ptr);
1.1 deraadt 1631: }
1632:
1.16 markus 1633: /*
1634: * Sends a diagnostic message from the server to the client. This message
1635: * can be sent at any time (but not while constructing another message). The
1636: * message is printed immediately, but only if the client is being executed
1637: * in verbose mode. These messages are primarily intended to ease debugging
1638: * authentication problems. The length of the formatted message must not
1639: * exceed 1024 bytes. This will automatically call packet_write_wait.
1640: */
1.1 deraadt 1641:
1.2 provos 1642: void
1.14 markus 1643: packet_send_debug(const char *fmt,...)
1.1 deraadt 1644: {
1.14 markus 1645: char buf[1024];
1646: va_list args;
1.39 markus 1647:
1648: if (compat20 && (datafellows & SSH_BUG_DEBUG))
1649: return;
1.14 markus 1650:
1651: va_start(args, fmt);
1652: vsnprintf(buf, sizeof(buf), fmt, args);
1653: va_end(args);
1654:
1.30 markus 1655: if (compat20) {
1656: packet_start(SSH2_MSG_DEBUG);
1657: packet_put_char(0); /* bool: always display */
1658: packet_put_cstring(buf);
1659: packet_put_cstring("");
1660: } else {
1661: packet_start(SSH_MSG_DEBUG);
1662: packet_put_cstring(buf);
1663: }
1.14 markus 1664: packet_send();
1665: packet_write_wait();
1.1 deraadt 1666: }
1667:
1.16 markus 1668: /*
1669: * Logs the error plus constructs and sends a disconnect packet, closes the
1670: * connection, and exits. This function never returns. The error message
1671: * should not contain a newline. The length of the formatted message must
1672: * not exceed 1024 bytes.
1673: */
1.1 deraadt 1674:
1.2 provos 1675: void
1.14 markus 1676: packet_disconnect(const char *fmt,...)
1.1 deraadt 1677: {
1.14 markus 1678: char buf[1024];
1679: va_list args;
1680: static int disconnecting = 0;
1.97 deraadt 1681:
1.14 markus 1682: if (disconnecting) /* Guard against recursive invocations. */
1683: fatal("packet_disconnect called recursively.");
1684: disconnecting = 1;
1685:
1.16 markus 1686: /*
1687: * Format the message. Note that the caller must make sure the
1688: * message is of limited size.
1689: */
1.14 markus 1690: va_start(args, fmt);
1691: vsnprintf(buf, sizeof(buf), fmt, args);
1692: va_end(args);
1693:
1.99 markus 1694: /* Display the error locally */
1.106 itojun 1695: logit("Disconnecting: %.100s", buf);
1.99 markus 1696:
1.14 markus 1697: /* Send the disconnect message to the other side, and wait for it to get sent. */
1.25 markus 1698: if (compat20) {
1699: packet_start(SSH2_MSG_DISCONNECT);
1700: packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR);
1701: packet_put_cstring(buf);
1702: packet_put_cstring("");
1703: } else {
1704: packet_start(SSH_MSG_DISCONNECT);
1.65 markus 1705: packet_put_cstring(buf);
1.25 markus 1706: }
1.14 markus 1707: packet_send();
1708: packet_write_wait();
1709:
1710: /* Stop listening for connections. */
1.67 markus 1711: channel_close_all();
1.14 markus 1712:
1713: /* Close the connection. */
1714: packet_close();
1.112 markus 1715: cleanup_exit(255);
1.1 deraadt 1716: }
1717:
1.16 markus 1718: /* Checks if there is any buffered output, and tries to write some of the output. */
1.1 deraadt 1719:
1.2 provos 1720: void
1.73 itojun 1721: packet_write_poll(void)
1.1 deraadt 1722: {
1.161 andreas 1723: int len = buffer_len(&active_state->output);
1.163 andreas 1724: int cont;
1.97 deraadt 1725:
1.14 markus 1726: if (len > 0) {
1.163 andreas 1727: cont = 0;
1728: len = roaming_write(active_state->connection_out,
1729: buffer_ptr(&active_state->output), len, &cont);
1.156 djm 1730: if (len == -1) {
1731: if (errno == EINTR || errno == EAGAIN)
1.14 markus 1732: return;
1.156 djm 1733: fatal("Write failed: %.100s", strerror(errno));
1.14 markus 1734: }
1.163 andreas 1735: if (len == 0 && !cont)
1.156 djm 1736: fatal("Write connection closed");
1.161 andreas 1737: buffer_consume(&active_state->output, len);
1.14 markus 1738: }
1.1 deraadt 1739: }
1740:
1.16 markus 1741: /*
1742: * Calls packet_write_poll repeatedly until all pending output data has been
1743: * written.
1744: */
1.1 deraadt 1745:
1.2 provos 1746: void
1.73 itojun 1747: packet_write_wait(void)
1.1 deraadt 1748: {
1.56 millert 1749: fd_set *setp;
1.188 djm 1750: int ret, ms_remain = 0;
1.154 dtucker 1751: struct timeval start, timeout, *timeoutp = NULL;
1.56 millert 1752:
1.161 andreas 1753: setp = (fd_set *)xcalloc(howmany(active_state->connection_out + 1,
1754: NFDBITS), sizeof(fd_mask));
1.14 markus 1755: packet_write_poll();
1756: while (packet_have_data_to_write()) {
1.161 andreas 1757: memset(setp, 0, howmany(active_state->connection_out + 1,
1758: NFDBITS) * sizeof(fd_mask));
1759: FD_SET(active_state->connection_out, setp);
1.154 dtucker 1760:
1.161 andreas 1761: if (active_state->packet_timeout_ms > 0) {
1762: ms_remain = active_state->packet_timeout_ms;
1.154 dtucker 1763: timeoutp = &timeout;
1764: }
1765: for (;;) {
1.161 andreas 1766: if (active_state->packet_timeout_ms != -1) {
1.154 dtucker 1767: ms_to_timeval(&timeout, ms_remain);
1768: gettimeofday(&start, NULL);
1769: }
1.161 andreas 1770: if ((ret = select(active_state->connection_out + 1,
1771: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1772: break;
1.161 andreas 1773: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1774: break;
1.161 andreas 1775: if (active_state->packet_timeout_ms == -1)
1.154 dtucker 1776: continue;
1777: ms_subtract_diff(&start, &ms_remain);
1778: if (ms_remain <= 0) {
1779: ret = 0;
1780: break;
1781: }
1782: }
1783: if (ret == 0) {
1784: logit("Connection to %.200s timed out while "
1785: "waiting to write", get_remote_ipaddr());
1786: cleanup_exit(255);
1787: }
1.14 markus 1788: packet_write_poll();
1789: }
1.186 djm 1790: free(setp);
1.1 deraadt 1791: }
1792:
1793: /* Returns true if there is buffered data to write to the connection. */
1794:
1.2 provos 1795: int
1.73 itojun 1796: packet_have_data_to_write(void)
1.1 deraadt 1797: {
1.161 andreas 1798: return buffer_len(&active_state->output) != 0;
1.1 deraadt 1799: }
1800:
1801: /* Returns true if there is not too much data to write to the connection. */
1802:
1.2 provos 1803: int
1.73 itojun 1804: packet_not_very_much_data_to_write(void)
1.1 deraadt 1805: {
1.161 andreas 1806: if (active_state->interactive_mode)
1807: return buffer_len(&active_state->output) < 16384;
1.14 markus 1808: else
1.161 andreas 1809: return buffer_len(&active_state->output) < 128 * 1024;
1.1 deraadt 1810: }
1811:
1.102 markus 1812: static void
1.172 djm 1813: packet_set_tos(int tos)
1.101 markus 1814: {
1.173 djm 1815: if (!packet_connection_is_on_socket())
1.101 markus 1816: return;
1.173 djm 1817: switch (packet_connection_af()) {
1818: case AF_INET:
1819: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1820: if (setsockopt(active_state->connection_in,
1821: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
1822: error("setsockopt IP_TOS %d: %.100s:",
1823: tos, strerror(errno));
1824: break;
1825: case AF_INET6:
1826: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1827: if (setsockopt(active_state->connection_in,
1828: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
1829: error("setsockopt IPV6_TCLASS %d: %.100s:",
1830: tos, strerror(errno));
1831: break;
1832: }
1.101 markus 1833: }
1834:
1.1 deraadt 1835: /* Informs that the current session is interactive. Sets IP flags for that. */
1836:
1.2 provos 1837: void
1.172 djm 1838: packet_set_interactive(int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 1839: {
1.165 andreas 1840: if (active_state->set_interactive_called)
1.43 markus 1841: return;
1.165 andreas 1842: active_state->set_interactive_called = 1;
1.1 deraadt 1843:
1.14 markus 1844: /* Record that we are in interactive mode. */
1.161 andreas 1845: active_state->interactive_mode = interactive;
1.1 deraadt 1846:
1.19 markus 1847: /* Only set socket options if using a socket. */
1848: if (!packet_connection_is_on_socket())
1.14 markus 1849: return;
1.161 andreas 1850: set_nodelay(active_state->connection_in);
1.172 djm 1851: packet_set_tos(interactive ? qos_interactive : qos_bulk);
1.1 deraadt 1852: }
1853:
1854: /* Returns true if the current connection is interactive. */
1855:
1.2 provos 1856: int
1.73 itojun 1857: packet_is_interactive(void)
1.1 deraadt 1858: {
1.161 andreas 1859: return active_state->interactive_mode;
1.12 markus 1860: }
1861:
1.113 deraadt 1862: int
1.108 markus 1863: packet_set_maxsize(u_int s)
1.12 markus 1864: {
1.165 andreas 1865: if (active_state->set_maxsize_called) {
1.106 itojun 1866: logit("packet_set_maxsize: called twice: old %d new %d",
1.161 andreas 1867: active_state->max_packet_size, s);
1.14 markus 1868: return -1;
1869: }
1870: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 1871: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 1872: return -1;
1873: }
1.165 andreas 1874: active_state->set_maxsize_called = 1;
1.66 markus 1875: debug("packet_set_maxsize: setting to %d", s);
1.161 andreas 1876: active_state->max_packet_size = s;
1.14 markus 1877: return s;
1.53 markus 1878: }
1879:
1.161 andreas 1880: int
1881: packet_inc_alive_timeouts(void)
1882: {
1883: return ++active_state->keep_alive_timeouts;
1884: }
1885:
1886: void
1887: packet_set_alive_timeouts(int ka)
1888: {
1889: active_state->keep_alive_timeouts = ka;
1890: }
1891:
1892: u_int
1893: packet_get_maxsize(void)
1894: {
1895: return active_state->max_packet_size;
1896: }
1897:
1.71 markus 1898: /* roundup current message to pad bytes */
1899: void
1900: packet_add_padding(u_char pad)
1901: {
1.161 andreas 1902: active_state->extra_pad = pad;
1.71 markus 1903: }
1904:
1.53 markus 1905: /*
1906: * 9.2. Ignored Data Message
1.61 markus 1907: *
1.53 markus 1908: * byte SSH_MSG_IGNORE
1909: * string data
1.61 markus 1910: *
1.53 markus 1911: * All implementations MUST understand (and ignore) this message at any
1912: * time (after receiving the protocol version). No implementation is
1913: * required to send them. This message can be used as an additional
1914: * protection measure against advanced traffic analysis techniques.
1915: */
1.54 markus 1916: void
1917: packet_send_ignore(int nbytes)
1918: {
1.115 avsm 1919: u_int32_t rnd = 0;
1.54 markus 1920: int i;
1921:
1922: packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE);
1.53 markus 1923: packet_put_int(nbytes);
1.75 deraadt 1924: for (i = 0; i < nbytes; i++) {
1.53 markus 1925: if (i % 4 == 0)
1.115 avsm 1926: rnd = arc4random();
1.129 deraadt 1927: packet_put_char((u_char)rnd & 0xff);
1.115 avsm 1928: rnd >>= 8;
1.53 markus 1929: }
1.105 markus 1930: }
1931:
1.113 deraadt 1932: #define MAX_PACKETS (1U<<31)
1.105 markus 1933: int
1934: packet_need_rekeying(void)
1935: {
1936: if (datafellows & SSH_BUG_NOREKEY)
1937: return 0;
1938: return
1.161 andreas 1939: (active_state->p_send.packets > MAX_PACKETS) ||
1940: (active_state->p_read.packets > MAX_PACKETS) ||
1941: (active_state->max_blocks_out &&
1942: (active_state->p_send.blocks > active_state->max_blocks_out)) ||
1943: (active_state->max_blocks_in &&
1.184 dtucker 1944: (active_state->p_read.blocks > active_state->max_blocks_in)) ||
1945: (active_state->rekey_interval != 0 && active_state->rekey_time +
1.187 dtucker 1946: active_state->rekey_interval <= monotime());
1.105 markus 1947: }
1948:
1949: void
1.184 dtucker 1950: packet_set_rekey_limits(u_int32_t bytes, time_t seconds)
1.105 markus 1951: {
1.184 dtucker 1952: debug3("rekey after %lld bytes, %d seconds", (long long)bytes,
1953: (int)seconds);
1.161 andreas 1954: active_state->rekey_limit = bytes;
1.184 dtucker 1955: active_state->rekey_interval = seconds;
1956: /*
1957: * We set the time here so that in post-auth privsep slave we count
1958: * from the completion of the authentication.
1959: */
1.187 dtucker 1960: active_state->rekey_time = monotime();
1.184 dtucker 1961: }
1962:
1963: time_t
1964: packet_get_rekey_timeout(void)
1965: {
1966: time_t seconds;
1967:
1968: seconds = active_state->rekey_time + active_state->rekey_interval -
1.187 dtucker 1969: monotime();
1.185 dtucker 1970: return (seconds <= 0 ? 1 : seconds);
1.118 markus 1971: }
1972:
1973: void
1974: packet_set_server(void)
1975: {
1.161 andreas 1976: active_state->server_side = 1;
1.118 markus 1977: }
1978:
1979: void
1980: packet_set_authenticated(void)
1981: {
1.161 andreas 1982: active_state->after_authentication = 1;
1983: }
1984:
1985: void *
1986: packet_get_input(void)
1987: {
1988: return (void *)&active_state->input;
1989: }
1990:
1991: void *
1992: packet_get_output(void)
1993: {
1994: return (void *)&active_state->output;
1995: }
1996:
1997: void *
1998: packet_get_newkeys(int mode)
1999: {
2000: return (void *)active_state->newkeys[mode];
1.166 andreas 2001: }
2002:
2003: /*
2004: * Save the state for the real connection, and use a separate state when
2005: * resuming a suspended connection.
2006: */
2007: void
2008: packet_backup_state(void)
2009: {
2010: struct session_state *tmp;
2011:
2012: close(active_state->connection_in);
2013: active_state->connection_in = -1;
2014: close(active_state->connection_out);
2015: active_state->connection_out = -1;
2016: if (backup_state)
2017: tmp = backup_state;
2018: else
2019: tmp = alloc_session_state();
2020: backup_state = active_state;
2021: active_state = tmp;
2022: }
2023:
2024: /*
2025: * Swap in the old state when resuming a connecion.
2026: */
2027: void
2028: packet_restore_state(void)
2029: {
2030: struct session_state *tmp;
2031: void *buf;
2032: u_int len;
2033:
2034: tmp = backup_state;
2035: backup_state = active_state;
2036: active_state = tmp;
2037: active_state->connection_in = backup_state->connection_in;
2038: backup_state->connection_in = -1;
2039: active_state->connection_out = backup_state->connection_out;
2040: backup_state->connection_out = -1;
2041: len = buffer_len(&backup_state->input);
2042: if (len > 0) {
2043: buf = buffer_ptr(&backup_state->input);
2044: buffer_append(&active_state->input, buf, len);
2045: buffer_clear(&backup_state->input);
2046: add_recv_bytes(len);
1.196 markus 2047: }
2048: }
2049:
2050: /* Reset after_authentication and reset compression in post-auth privsep */
2051: void
2052: packet_set_postauth(void)
2053: {
2054: Comp *comp;
2055: int mode;
2056:
2057: debug("%s: called", __func__);
2058: /* This was set in net child, but is not visible in user child */
2059: active_state->after_authentication = 1;
2060: active_state->rekeying = 0;
2061: for (mode = 0; mode < MODE_MAX; mode++) {
2062: if (active_state->newkeys[mode] == NULL)
2063: continue;
2064: comp = &active_state->newkeys[mode]->comp;
2065: if (comp && comp->enabled)
2066: packet_init_compression();
1.166 andreas 2067: }
1.1 deraadt 2068: }
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