Annotation of src/usr.bin/ssh/packet.c, Revision 1.161
1.161 ! andreas 1: /* $OpenBSD: packet.c,v 1.160 2009/02/13 11:50:21 markus 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
1.76 stevesk 590: packet_put_string(const void *buf, u_int len)
1.1 deraadt 591: {
1.161 ! andreas 592: buffer_put_string(&active_state->outgoing_packet, buf, len);
1.1 deraadt 593: }
1.125 deraadt 594:
1.24 markus 595: void
596: packet_put_cstring(const char *str)
597: {
1.161 ! andreas 598: buffer_put_cstring(&active_state->outgoing_packet, str);
1.24 markus 599: }
1.125 deraadt 600:
1.24 markus 601: void
1.76 stevesk 602: packet_put_raw(const void *buf, u_int len)
1.24 markus 603: {
1.161 ! andreas 604: buffer_append(&active_state->outgoing_packet, buf, len);
1.24 markus 605: }
1.125 deraadt 606:
1.2 provos 607: void
1.14 markus 608: packet_put_bignum(BIGNUM * value)
1.1 deraadt 609: {
1.161 ! andreas 610: buffer_put_bignum(&active_state->outgoing_packet, value);
1.1 deraadt 611: }
1.125 deraadt 612:
1.24 markus 613: void
614: packet_put_bignum2(BIGNUM * value)
615: {
1.161 ! andreas 616: buffer_put_bignum2(&active_state->outgoing_packet, value);
1.24 markus 617: }
1.1 deraadt 618:
1.16 markus 619: /*
620: * Finalizes and sends the packet. If the encryption key has been set,
621: * encrypts the packet before sending.
622: */
1.14 markus 623:
1.68 itojun 624: static void
1.49 itojun 625: packet_send1(void)
1.1 deraadt 626: {
1.89 markus 627: u_char buf[8], *cp;
1.14 markus 628: int i, padding, len;
1.40 markus 629: u_int checksum;
1.115 avsm 630: u_int32_t rnd = 0;
1.14 markus 631:
1.16 markus 632: /*
633: * If using packet compression, compress the payload of the outgoing
634: * packet.
635: */
1.161 ! andreas 636: if (active_state->packet_compression) {
! 637: buffer_clear(&active_state->compression_buffer);
1.14 markus 638: /* Skip padding. */
1.161 ! andreas 639: buffer_consume(&active_state->outgoing_packet, 8);
1.14 markus 640: /* padding */
1.161 ! andreas 641: buffer_append(&active_state->compression_buffer,
! 642: "\0\0\0\0\0\0\0\0", 8);
! 643: buffer_compress(&active_state->outgoing_packet,
! 644: &active_state->compression_buffer);
! 645: buffer_clear(&active_state->outgoing_packet);
! 646: buffer_append(&active_state->outgoing_packet,
! 647: buffer_ptr(&active_state->compression_buffer),
! 648: buffer_len(&active_state->compression_buffer));
1.14 markus 649: }
650: /* Compute packet length without padding (add checksum, remove padding). */
1.161 ! andreas 651: len = buffer_len(&active_state->outgoing_packet) + 4 - 8;
1.14 markus 652:
1.32 markus 653: /* Insert padding. Initialized to zero in packet_start1() */
1.14 markus 654: padding = 8 - len % 8;
1.161 ! andreas 655: if (!active_state->send_context.plaintext) {
! 656: cp = buffer_ptr(&active_state->outgoing_packet);
1.14 markus 657: for (i = 0; i < padding; i++) {
658: if (i % 4 == 0)
1.115 avsm 659: rnd = arc4random();
660: cp[7 - i] = rnd & 0xff;
661: rnd >>= 8;
1.14 markus 662: }
663: }
1.161 ! andreas 664: buffer_consume(&active_state->outgoing_packet, 8 - padding);
1.14 markus 665:
666: /* Add check bytes. */
1.161 ! andreas 667: checksum = ssh_crc32(buffer_ptr(&active_state->outgoing_packet),
! 668: buffer_len(&active_state->outgoing_packet));
1.131 djm 669: put_u32(buf, checksum);
1.161 ! andreas 670: buffer_append(&active_state->outgoing_packet, buf, 4);
1.1 deraadt 671:
672: #ifdef PACKET_DEBUG
1.14 markus 673: fprintf(stderr, "packet_send plain: ");
1.161 ! andreas 674: buffer_dump(&active_state->outgoing_packet);
1.1 deraadt 675: #endif
676:
1.14 markus 677: /* Append to output. */
1.131 djm 678: put_u32(buf, len);
1.161 ! andreas 679: buffer_append(&active_state->output, buf, 4);
! 680: cp = buffer_append_space(&active_state->output,
! 681: buffer_len(&active_state->outgoing_packet));
! 682: cipher_crypt(&active_state->send_context, cp,
! 683: buffer_ptr(&active_state->outgoing_packet),
! 684: buffer_len(&active_state->outgoing_packet));
1.14 markus 685:
1.1 deraadt 686: #ifdef PACKET_DEBUG
1.14 markus 687: fprintf(stderr, "encrypted: ");
1.161 ! andreas 688: buffer_dump(&active_state->output);
1.1 deraadt 689: #endif
1.161 ! andreas 690: active_state->p_send.packets++;
! 691: active_state->p_send.bytes += len +
! 692: buffer_len(&active_state->outgoing_packet);
! 693: buffer_clear(&active_state->outgoing_packet);
1.1 deraadt 694:
1.16 markus 695: /*
1.120 djm 696: * Note that the packet is now only buffered in output. It won't be
1.16 markus 697: * actually sent until packet_write_wait or packet_write_poll is
698: * called.
699: */
1.1 deraadt 700: }
701:
1.91 markus 702: void
1.57 markus 703: set_newkeys(int mode)
704: {
705: Enc *enc;
706: Mac *mac;
707: Comp *comp;
708: CipherContext *cc;
1.105 markus 709: u_int64_t *max_blocks;
1.115 avsm 710: int crypt_type;
1.57 markus 711:
1.100 markus 712: debug2("set_newkeys: mode %d", mode);
1.57 markus 713:
1.88 markus 714: if (mode == MODE_OUT) {
1.161 ! andreas 715: cc = &active_state->send_context;
1.115 avsm 716: crypt_type = CIPHER_ENCRYPT;
1.161 ! andreas 717: active_state->p_send.packets = active_state->p_send.blocks = 0;
! 718: max_blocks = &active_state->max_blocks_out;
1.88 markus 719: } else {
1.161 ! andreas 720: cc = &active_state->receive_context;
1.115 avsm 721: crypt_type = CIPHER_DECRYPT;
1.161 ! andreas 722: active_state->p_read.packets = active_state->p_read.blocks = 0;
! 723: max_blocks = &active_state->max_blocks_in;
1.88 markus 724: }
1.161 ! andreas 725: if (active_state->newkeys[mode] != NULL) {
1.100 markus 726: debug("set_newkeys: rekeying");
1.88 markus 727: cipher_cleanup(cc);
1.161 ! andreas 728: enc = &active_state->newkeys[mode]->enc;
! 729: mac = &active_state->newkeys[mode]->mac;
! 730: comp = &active_state->newkeys[mode]->comp;
1.148 pvalchev 731: mac_clear(mac);
1.59 markus 732: xfree(enc->name);
733: xfree(enc->iv);
734: xfree(enc->key);
735: xfree(mac->name);
736: xfree(mac->key);
737: xfree(comp->name);
1.161 ! andreas 738: xfree(active_state->newkeys[mode]);
1.57 markus 739: }
1.161 ! andreas 740: active_state->newkeys[mode] = kex_get_newkeys(mode);
! 741: if (active_state->newkeys[mode] == NULL)
1.57 markus 742: fatal("newkeys: no keys for mode %d", mode);
1.161 ! andreas 743: enc = &active_state->newkeys[mode]->enc;
! 744: mac = &active_state->newkeys[mode]->mac;
! 745: comp = &active_state->newkeys[mode]->comp;
1.148 pvalchev 746: if (mac_init(mac) == 0)
1.57 markus 747: mac->enabled = 1;
748: DBG(debug("cipher_init_context: %d", mode));
1.88 markus 749: cipher_init(cc, enc->cipher, enc->key, enc->key_len,
1.115 avsm 750: enc->iv, enc->block_size, crypt_type);
1.91 markus 751: /* Deleting the keys does not gain extra security */
752: /* memset(enc->iv, 0, enc->block_size);
1.147 djm 753: memset(enc->key, 0, enc->key_len);
754: memset(mac->key, 0, mac->key_len); */
1.118 markus 755: if ((comp->type == COMP_ZLIB ||
1.161 ! andreas 756: (comp->type == COMP_DELAYED &&
! 757: active_state->after_authentication)) && comp->enabled == 0) {
1.60 markus 758: packet_init_compression();
759: if (mode == MODE_OUT)
760: buffer_compress_init_send(6);
761: else
762: buffer_compress_init_recv();
1.57 markus 763: comp->enabled = 1;
764: }
1.109 markus 765: /*
766: * The 2^(blocksize*2) limit is too expensive for 3DES,
767: * blowfish, etc, so enforce a 1GB limit for small blocksizes.
768: */
769: if (enc->block_size >= 16)
770: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
771: else
772: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.161 ! andreas 773: if (active_state->rekey_limit)
! 774: *max_blocks = MIN(*max_blocks,
! 775: active_state->rekey_limit / enc->block_size);
1.57 markus 776: }
777:
1.16 markus 778: /*
1.118 markus 779: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 780: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 781: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
782: */
783: static void
784: packet_enable_delayed_compress(void)
785: {
786: Comp *comp = NULL;
787: int mode;
788:
789: /*
790: * Remember that we are past the authentication step, so rekeying
791: * with COMP_DELAYED will turn on compression immediately.
792: */
1.161 ! andreas 793: active_state->after_authentication = 1;
1.118 markus 794: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 795: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.161 ! andreas 796: if (active_state->newkeys[mode] == NULL)
1.145 markus 797: continue;
1.161 ! andreas 798: comp = &active_state->newkeys[mode]->comp;
1.118 markus 799: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.119 markus 800: packet_init_compression();
1.118 markus 801: if (mode == MODE_OUT)
802: buffer_compress_init_send(6);
803: else
804: buffer_compress_init_recv();
805: comp->enabled = 1;
806: }
807: }
808: }
809:
810: /*
1.25 markus 811: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
812: */
1.68 itojun 813: static void
1.105 markus 814: packet_send2_wrapped(void)
1.25 markus 815: {
1.89 markus 816: u_char type, *cp, *macbuf = NULL;
1.71 markus 817: u_char padlen, pad;
1.40 markus 818: u_int packet_length = 0;
1.71 markus 819: u_int i, len;
1.115 avsm 820: u_int32_t rnd = 0;
1.25 markus 821: Enc *enc = NULL;
822: Mac *mac = NULL;
823: Comp *comp = NULL;
824: int block_size;
825:
1.161 ! andreas 826: if (active_state->newkeys[MODE_OUT] != NULL) {
! 827: enc = &active_state->newkeys[MODE_OUT]->enc;
! 828: mac = &active_state->newkeys[MODE_OUT]->mac;
! 829: comp = &active_state->newkeys[MODE_OUT]->comp;
1.25 markus 830: }
1.88 markus 831: block_size = enc ? enc->block_size : 8;
1.25 markus 832:
1.161 ! andreas 833: cp = buffer_ptr(&active_state->outgoing_packet);
1.89 markus 834: type = cp[5];
1.25 markus 835:
836: #ifdef PACKET_DEBUG
837: fprintf(stderr, "plain: ");
1.161 ! andreas 838: buffer_dump(&active_state->outgoing_packet);
1.25 markus 839: #endif
840:
841: if (comp && comp->enabled) {
1.161 ! andreas 842: len = buffer_len(&active_state->outgoing_packet);
1.25 markus 843: /* skip header, compress only payload */
1.161 ! andreas 844: buffer_consume(&active_state->outgoing_packet, 5);
! 845: buffer_clear(&active_state->compression_buffer);
! 846: buffer_compress(&active_state->outgoing_packet,
! 847: &active_state->compression_buffer);
! 848: buffer_clear(&active_state->outgoing_packet);
! 849: buffer_append(&active_state->outgoing_packet, "\0\0\0\0\0", 5);
! 850: buffer_append(&active_state->outgoing_packet,
! 851: buffer_ptr(&active_state->compression_buffer),
! 852: buffer_len(&active_state->compression_buffer));
1.25 markus 853: DBG(debug("compression: raw %d compressed %d", len,
1.161 ! andreas 854: buffer_len(&active_state->outgoing_packet)));
1.25 markus 855: }
856:
857: /* sizeof (packet_len + pad_len + payload) */
1.161 ! andreas 858: len = buffer_len(&active_state->outgoing_packet);
1.25 markus 859:
860: /*
861: * calc size of padding, alloc space, get random data,
862: * minimum padding is 4 bytes
863: */
864: padlen = block_size - (len % block_size);
865: if (padlen < 4)
866: padlen += block_size;
1.161 ! andreas 867: if (active_state->extra_pad) {
1.71 markus 868: /* will wrap if extra_pad+padlen > 255 */
1.161 ! andreas 869: active_state->extra_pad =
! 870: roundup(active_state->extra_pad, block_size);
! 871: pad = active_state->extra_pad -
! 872: ((len + padlen) % active_state->extra_pad);
1.93 markus 873: debug3("packet_send2: adding %d (len %d padlen %d extra_pad %d)",
1.161 ! andreas 874: pad, len, padlen, active_state->extra_pad);
1.71 markus 875: padlen += pad;
1.161 ! andreas 876: active_state->extra_pad = 0;
1.71 markus 877: }
1.161 ! andreas 878: cp = buffer_append_space(&active_state->outgoing_packet, padlen);
! 879: if (enc && !active_state->send_context.plaintext) {
1.32 markus 880: /* random padding */
1.25 markus 881: for (i = 0; i < padlen; i++) {
882: if (i % 4 == 0)
1.115 avsm 883: rnd = arc4random();
884: cp[i] = rnd & 0xff;
885: rnd >>= 8;
1.25 markus 886: }
1.32 markus 887: } else {
888: /* clear padding */
889: memset(cp, 0, padlen);
1.25 markus 890: }
891: /* packet_length includes payload, padding and padding length field */
1.161 ! andreas 892: packet_length = buffer_len(&active_state->outgoing_packet) - 4;
! 893: cp = buffer_ptr(&active_state->outgoing_packet);
1.131 djm 894: put_u32(cp, packet_length);
1.89 markus 895: cp[4] = padlen;
1.25 markus 896: DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen));
897:
898: /* compute MAC over seqnr and packet(length fields, payload, padding) */
899: if (mac && mac->enabled) {
1.161 ! andreas 900: macbuf = mac_compute(mac, active_state->p_send.seqnr,
! 901: buffer_ptr(&active_state->outgoing_packet),
! 902: buffer_len(&active_state->outgoing_packet));
! 903: DBG(debug("done calc MAC out #%d", active_state->p_send.seqnr));
1.25 markus 904: }
905: /* encrypt packet and append to output buffer. */
1.161 ! andreas 906: cp = buffer_append_space(&active_state->output,
! 907: buffer_len(&active_state->outgoing_packet));
! 908: cipher_crypt(&active_state->send_context, cp,
! 909: buffer_ptr(&active_state->outgoing_packet),
! 910: buffer_len(&active_state->outgoing_packet));
1.25 markus 911: /* append unencrypted MAC */
912: if (mac && mac->enabled)
1.161 ! andreas 913: buffer_append(&active_state->output, macbuf, mac->mac_len);
1.25 markus 914: #ifdef PACKET_DEBUG
915: fprintf(stderr, "encrypted: ");
1.161 ! andreas 916: buffer_dump(&active_state->output);
1.25 markus 917: #endif
1.29 markus 918: /* increment sequence number for outgoing packets */
1.161 ! andreas 919: if (++active_state->p_send.seqnr == 0)
1.106 itojun 920: logit("outgoing seqnr wraps around");
1.161 ! andreas 921: if (++active_state->p_send.packets == 0)
1.105 markus 922: if (!(datafellows & SSH_BUG_NOREKEY))
923: fatal("XXX too many packets with same key");
1.161 ! andreas 924: active_state->p_send.blocks += (packet_length + 4) / block_size;
! 925: active_state->p_send.bytes += packet_length + 4;
! 926: buffer_clear(&active_state->outgoing_packet);
1.25 markus 927:
1.57 markus 928: if (type == SSH2_MSG_NEWKEYS)
929: set_newkeys(MODE_OUT);
1.161 ! andreas 930: else if (type == SSH2_MSG_USERAUTH_SUCCESS && active_state->server_side)
1.118 markus 931: packet_enable_delayed_compress();
1.25 markus 932: }
933:
1.105 markus 934: static void
935: packet_send2(void)
936: {
937: static int rekeying = 0;
938: struct packet *p;
939: u_char type, *cp;
940:
1.161 ! andreas 941: cp = buffer_ptr(&active_state->outgoing_packet);
1.105 markus 942: type = cp[5];
943:
944: /* during rekeying we can only send key exchange messages */
945: if (rekeying) {
946: if (!((type >= SSH2_MSG_TRANSPORT_MIN) &&
947: (type <= SSH2_MSG_TRANSPORT_MAX))) {
948: debug("enqueue packet: %u", type);
949: p = xmalloc(sizeof(*p));
950: p->type = type;
1.161 ! andreas 951: memcpy(&p->payload, &active_state->outgoing_packet,
! 952: sizeof(Buffer));
! 953: buffer_init(&active_state->outgoing_packet);
! 954: TAILQ_INSERT_TAIL(&active_state->outgoing, p, next);
1.105 markus 955: return;
956: }
957: }
958:
959: /* rekeying starts with sending KEXINIT */
960: if (type == SSH2_MSG_KEXINIT)
961: rekeying = 1;
962:
963: packet_send2_wrapped();
964:
965: /* after a NEWKEYS message we can send the complete queue */
966: if (type == SSH2_MSG_NEWKEYS) {
967: rekeying = 0;
1.161 ! andreas 968: while ((p = TAILQ_FIRST(&active_state->outgoing))) {
1.105 markus 969: type = p->type;
970: debug("dequeue packet: %u", type);
1.161 ! andreas 971: buffer_free(&active_state->outgoing_packet);
! 972: memcpy(&active_state->outgoing_packet, &p->payload,
1.105 markus 973: sizeof(Buffer));
1.161 ! andreas 974: TAILQ_REMOVE(&active_state->outgoing, p, next);
1.105 markus 975: xfree(p);
976: packet_send2_wrapped();
977: }
978: }
979: }
980:
1.25 markus 981: void
1.73 itojun 982: packet_send(void)
1.25 markus 983: {
1.62 markus 984: if (compat20)
1.25 markus 985: packet_send2();
986: else
987: packet_send1();
988: DBG(debug("packet_send done"));
989: }
990:
991: /*
1.16 markus 992: * Waits until a packet has been received, and returns its type. Note that
993: * no other data is processed until this returns, so this function should not
994: * be used during the interactive session.
995: */
1.1 deraadt 996:
1.2 provos 997: int
1.82 markus 998: packet_read_seqnr(u_int32_t *seqnr_p)
1.1 deraadt 999: {
1.154 dtucker 1000: int type, len, ret, ms_remain;
1.56 millert 1001: fd_set *setp;
1.14 markus 1002: char buf[8192];
1.155 deraadt 1003: struct timeval timeout, start, *timeoutp = NULL;
1004:
1.25 markus 1005: DBG(debug("packet_read()"));
1.14 markus 1006:
1.161 ! andreas 1007: setp = (fd_set *)xcalloc(howmany(active_state->connection_in + 1,
! 1008: NFDBITS), sizeof(fd_mask));
1.56 millert 1009:
1.14 markus 1010: /* Since we are blocking, ensure that all written packets have been sent. */
1011: packet_write_wait();
1012:
1013: /* Stay in the loop until we have received a complete packet. */
1014: for (;;) {
1015: /* Try to read a packet from the buffer. */
1.82 markus 1016: type = packet_read_poll_seqnr(seqnr_p);
1.62 markus 1017: if (!compat20 && (
1.32 markus 1018: type == SSH_SMSG_SUCCESS
1.14 markus 1019: || type == SSH_SMSG_FAILURE
1020: || type == SSH_CMSG_EOF
1.32 markus 1021: || type == SSH_CMSG_EXIT_CONFIRMATION))
1.79 markus 1022: packet_check_eom();
1.14 markus 1023: /* If we got a packet, return it. */
1.56 millert 1024: if (type != SSH_MSG_NONE) {
1025: xfree(setp);
1.14 markus 1026: return type;
1.56 millert 1027: }
1.16 markus 1028: /*
1029: * Otherwise, wait for some data to arrive, add it to the
1030: * buffer, and try again.
1031: */
1.161 ! andreas 1032: memset(setp, 0, howmany(active_state->connection_in + 1,
! 1033: NFDBITS) * sizeof(fd_mask));
! 1034: FD_SET(active_state->connection_in, setp);
1.16 markus 1035:
1.161 ! andreas 1036: if (active_state->packet_timeout_ms > 0) {
! 1037: ms_remain = active_state->packet_timeout_ms;
1.154 dtucker 1038: timeoutp = &timeout;
1039: }
1.14 markus 1040: /* Wait for some data to arrive. */
1.154 dtucker 1041: for (;;) {
1.161 ! andreas 1042: if (active_state->packet_timeout_ms != -1) {
1.154 dtucker 1043: ms_to_timeval(&timeout, ms_remain);
1044: gettimeofday(&start, NULL);
1045: }
1.161 ! andreas 1046: if ((ret = select(active_state->connection_in + 1, setp,
! 1047: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1048: break;
1.161 ! andreas 1049: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1050: break;
1.161 ! andreas 1051: if (active_state->packet_timeout_ms == -1)
1.154 dtucker 1052: continue;
1053: ms_subtract_diff(&start, &ms_remain);
1054: if (ms_remain <= 0) {
1055: ret = 0;
1056: break;
1057: }
1058: }
1059: if (ret == 0) {
1060: logit("Connection to %.200s timed out while "
1061: "waiting to read", get_remote_ipaddr());
1062: cleanup_exit(255);
1063: }
1.14 markus 1064: /* Read data from the socket. */
1.161 ! andreas 1065: len = read(active_state->connection_in, buf, sizeof(buf));
1.18 markus 1066: if (len == 0) {
1.106 itojun 1067: logit("Connection closed by %.200s", get_remote_ipaddr());
1.112 markus 1068: cleanup_exit(255);
1.18 markus 1069: }
1.14 markus 1070: if (len < 0)
1071: fatal("Read from socket failed: %.100s", strerror(errno));
1072: /* Append it to the buffer. */
1073: packet_process_incoming(buf, len);
1074: }
1075: /* NOTREACHED */
1.1 deraadt 1076: }
1077:
1.77 djm 1078: int
1.82 markus 1079: packet_read(void)
1.77 djm 1080: {
1.82 markus 1081: return packet_read_seqnr(NULL);
1.77 djm 1082: }
1083:
1.16 markus 1084: /*
1085: * Waits until a packet has been received, verifies that its type matches
1086: * that given, and gives a fatal error and exits if there is a mismatch.
1087: */
1.1 deraadt 1088:
1.2 provos 1089: void
1.82 markus 1090: packet_read_expect(int expected_type)
1.1 deraadt 1091: {
1.14 markus 1092: int type;
1.1 deraadt 1093:
1.82 markus 1094: type = packet_read();
1.14 markus 1095: if (type != expected_type)
1096: packet_disconnect("Protocol error: expected packet type %d, got %d",
1.25 markus 1097: expected_type, type);
1.1 deraadt 1098: }
1099:
1100: /* Checks if a full packet is available in the data received so far via
1.14 markus 1101: * packet_process_incoming. If so, reads the packet; otherwise returns
1102: * SSH_MSG_NONE. This does not wait for data from the connection.
1103: *
1.150 dtucker 1104: * SSH_MSG_DISCONNECT is handled specially here. Also,
1105: * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1106: * to higher levels.
1.14 markus 1107: */
1.1 deraadt 1108:
1.68 itojun 1109: static int
1.82 markus 1110: packet_read_poll1(void)
1.1 deraadt 1111: {
1.40 markus 1112: u_int len, padded_len;
1.89 markus 1113: u_char *cp, type;
1.40 markus 1114: u_int checksum, stored_checksum;
1.14 markus 1115:
1116: /* Check if input size is less than minimum packet size. */
1.161 ! andreas 1117: if (buffer_len(&active_state->input) < 4 + 8)
1.14 markus 1118: return SSH_MSG_NONE;
1119: /* Get length of incoming packet. */
1.161 ! andreas 1120: cp = buffer_ptr(&active_state->input);
1.131 djm 1121: len = get_u32(cp);
1.14 markus 1122: if (len < 1 + 2 + 2 || len > 256 * 1024)
1.98 markus 1123: packet_disconnect("Bad packet length %u.", len);
1.14 markus 1124: padded_len = (len + 8) & ~7;
1125:
1126: /* Check if the packet has been entirely received. */
1.161 ! andreas 1127: if (buffer_len(&active_state->input) < 4 + padded_len)
1.14 markus 1128: return SSH_MSG_NONE;
1129:
1130: /* The entire packet is in buffer. */
1131:
1132: /* Consume packet length. */
1.161 ! andreas 1133: buffer_consume(&active_state->input, 4);
1.14 markus 1134:
1.62 markus 1135: /*
1136: * Cryptographic attack detector for ssh
1137: * (C)1998 CORE-SDI, Buenos Aires Argentina
1138: * Ariel Futoransky(futo@core-sdi.com)
1139: */
1.161 ! andreas 1140: if (!active_state->receive_context.plaintext) {
! 1141: switch (detect_attack(buffer_ptr(&active_state->input),
! 1142: padded_len)) {
1.144 djm 1143: case DEATTACK_DETECTED:
1144: packet_disconnect("crc32 compensation attack: "
1145: "network attack detected");
1146: case DEATTACK_DOS_DETECTED:
1147: packet_disconnect("deattack denial of "
1148: "service detected");
1149: }
1150: }
1.62 markus 1151:
1152: /* Decrypt data to incoming_packet. */
1.161 ! andreas 1153: buffer_clear(&active_state->incoming_packet);
! 1154: cp = buffer_append_space(&active_state->incoming_packet, padded_len);
! 1155: cipher_crypt(&active_state->receive_context, cp,
! 1156: buffer_ptr(&active_state->input), padded_len);
1.62 markus 1157:
1.161 ! andreas 1158: buffer_consume(&active_state->input, padded_len);
1.1 deraadt 1159:
1160: #ifdef PACKET_DEBUG
1.14 markus 1161: fprintf(stderr, "read_poll plain: ");
1.161 ! andreas 1162: buffer_dump(&active_state->incoming_packet);
1.1 deraadt 1163: #endif
1164:
1.14 markus 1165: /* Compute packet checksum. */
1.161 ! andreas 1166: checksum = ssh_crc32(buffer_ptr(&active_state->incoming_packet),
! 1167: buffer_len(&active_state->incoming_packet) - 4);
1.14 markus 1168:
1169: /* Skip padding. */
1.161 ! andreas 1170: buffer_consume(&active_state->incoming_packet, 8 - len % 8);
1.14 markus 1171:
1172: /* Test check bytes. */
1.161 ! andreas 1173: if (len != buffer_len(&active_state->incoming_packet))
1.77 djm 1174: packet_disconnect("packet_read_poll1: len %d != buffer_len %d.",
1.161 ! andreas 1175: len, buffer_len(&active_state->incoming_packet));
1.14 markus 1176:
1.161 ! andreas 1177: cp = (u_char *)buffer_ptr(&active_state->incoming_packet) + len - 4;
1.131 djm 1178: stored_checksum = get_u32(cp);
1.14 markus 1179: if (checksum != stored_checksum)
1180: packet_disconnect("Corrupted check bytes on input.");
1.161 ! andreas 1181: buffer_consume_end(&active_state->incoming_packet, 4);
1.14 markus 1182:
1.161 ! andreas 1183: if (active_state->packet_compression) {
! 1184: buffer_clear(&active_state->compression_buffer);
! 1185: buffer_uncompress(&active_state->incoming_packet,
! 1186: &active_state->compression_buffer);
! 1187: buffer_clear(&active_state->incoming_packet);
! 1188: buffer_append(&active_state->incoming_packet,
! 1189: buffer_ptr(&active_state->compression_buffer),
! 1190: buffer_len(&active_state->compression_buffer));
! 1191: }
! 1192: active_state->p_read.packets++;
! 1193: active_state->p_read.bytes += padded_len + 4;
! 1194: type = buffer_get_char(&active_state->incoming_packet);
1.116 markus 1195: if (type < SSH_MSG_MIN || type > SSH_MSG_MAX)
1196: packet_disconnect("Invalid ssh1 packet type: %d", type);
1.62 markus 1197: return type;
1.1 deraadt 1198: }
1.14 markus 1199:
1.68 itojun 1200: static int
1.82 markus 1201: packet_read_poll2(u_int32_t *seqnr_p)
1.25 markus 1202: {
1.40 markus 1203: u_int padlen, need;
1.89 markus 1204: u_char *macbuf, *cp, type;
1.117 djm 1205: u_int maclen, block_size;
1.25 markus 1206: Enc *enc = NULL;
1207: Mac *mac = NULL;
1208: Comp *comp = NULL;
1209:
1.161 ! andreas 1210: if (active_state->packet_discard)
1.159 markus 1211: return SSH_MSG_NONE;
1212:
1.161 ! andreas 1213: if (active_state->newkeys[MODE_IN] != NULL) {
! 1214: enc = &active_state->newkeys[MODE_IN]->enc;
! 1215: mac = &active_state->newkeys[MODE_IN]->mac;
! 1216: comp = &active_state->newkeys[MODE_IN]->comp;
1.25 markus 1217: }
1218: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1219: block_size = enc ? enc->block_size : 8;
1.25 markus 1220:
1.161 ! andreas 1221: if (active_state->packlen == 0) {
1.25 markus 1222: /*
1223: * check if input size is less than the cipher block size,
1224: * decrypt first block and extract length of incoming packet
1225: */
1.161 ! andreas 1226: if (buffer_len(&active_state->input) < block_size)
1.25 markus 1227: return SSH_MSG_NONE;
1.161 ! andreas 1228: buffer_clear(&active_state->incoming_packet);
! 1229: cp = buffer_append_space(&active_state->incoming_packet,
1.25 markus 1230: block_size);
1.161 ! andreas 1231: cipher_crypt(&active_state->receive_context, cp,
! 1232: buffer_ptr(&active_state->input), block_size);
! 1233: cp = buffer_ptr(&active_state->incoming_packet);
! 1234: active_state->packlen = get_u32(cp);
! 1235: if (active_state->packlen < 1 + 4 ||
! 1236: active_state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1237: #ifdef PACKET_DEBUG
1.161 ! andreas 1238: buffer_dump(&active_state->incoming_packet);
1.110 markus 1239: #endif
1.161 ! andreas 1240: logit("Bad packet length %u.", active_state->packlen);
! 1241: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1242: PACKET_MAX_SIZE);
1243: return SSH_MSG_NONE;
1.25 markus 1244: }
1.161 ! andreas 1245: DBG(debug("input: packet len %u", active_state->packlen+4));
! 1246: buffer_consume(&active_state->input, block_size);
1.25 markus 1247: }
1248: /* we have a partial packet of block_size bytes */
1.161 ! andreas 1249: need = 4 + active_state->packlen - block_size;
1.25 markus 1250: DBG(debug("partial packet %d, need %d, maclen %d", block_size,
1251: need, maclen));
1.158 markus 1252: if (need % block_size != 0) {
1253: logit("padding error: need %d block %d mod %d",
1.25 markus 1254: need, block_size, need % block_size);
1.161 ! andreas 1255: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1256: PACKET_MAX_SIZE - block_size);
1257: return SSH_MSG_NONE;
1.158 markus 1258: }
1.25 markus 1259: /*
1260: * check if the entire packet has been received and
1261: * decrypt into incoming_packet
1262: */
1.161 ! andreas 1263: if (buffer_len(&active_state->input) < need + maclen)
1.25 markus 1264: return SSH_MSG_NONE;
1265: #ifdef PACKET_DEBUG
1266: fprintf(stderr, "read_poll enc/full: ");
1.161 ! andreas 1267: buffer_dump(&active_state->input);
1.25 markus 1268: #endif
1.161 ! andreas 1269: cp = buffer_append_space(&active_state->incoming_packet, need);
! 1270: cipher_crypt(&active_state->receive_context, cp,
! 1271: buffer_ptr(&active_state->input), need);
! 1272: buffer_consume(&active_state->input, need);
1.25 markus 1273: /*
1274: * compute MAC over seqnr and packet,
1275: * increment sequence number for incoming packet
1276: */
1.29 markus 1277: if (mac && mac->enabled) {
1.161 ! andreas 1278: macbuf = mac_compute(mac, active_state->p_read.seqnr,
! 1279: buffer_ptr(&active_state->incoming_packet),
! 1280: buffer_len(&active_state->incoming_packet));
! 1281: if (memcmp(macbuf, buffer_ptr(&active_state->input),
! 1282: mac->mac_len) != 0) {
1.159 markus 1283: logit("Corrupted MAC on input.");
1284: if (need > PACKET_MAX_SIZE)
1285: fatal("internal error need %d", need);
1.161 ! andreas 1286: packet_start_discard(enc, mac, active_state->packlen,
1.159 markus 1287: PACKET_MAX_SIZE - need);
1288: return SSH_MSG_NONE;
1289: }
1290:
1.161 ! andreas 1291: DBG(debug("MAC #%d ok", active_state->p_read.seqnr));
! 1292: buffer_consume(&active_state->input, mac->mac_len);
1.25 markus 1293: }
1.159 markus 1294: /* XXX now it's safe to use fatal/packet_disconnect */
1.77 djm 1295: if (seqnr_p != NULL)
1.161 ! andreas 1296: *seqnr_p = active_state->p_read.seqnr;
! 1297: if (++active_state->p_read.seqnr == 0)
1.106 itojun 1298: logit("incoming seqnr wraps around");
1.161 ! andreas 1299: if (++active_state->p_read.packets == 0)
1.105 markus 1300: if (!(datafellows & SSH_BUG_NOREKEY))
1301: fatal("XXX too many packets with same key");
1.161 ! andreas 1302: active_state->p_read.blocks += (active_state->packlen + 4) / block_size;
! 1303: active_state->p_read.bytes += active_state->packlen + 4;
1.25 markus 1304:
1305: /* get padlen */
1.161 ! andreas 1306: cp = buffer_ptr(&active_state->incoming_packet);
1.89 markus 1307: padlen = cp[4];
1.25 markus 1308: DBG(debug("input: padlen %d", padlen));
1309: if (padlen < 4)
1310: packet_disconnect("Corrupted padlen %d on input.", padlen);
1311:
1312: /* skip packet size + padlen, discard padding */
1.161 ! andreas 1313: buffer_consume(&active_state->incoming_packet, 4 + 1);
! 1314: buffer_consume_end(&active_state->incoming_packet, padlen);
1.25 markus 1315:
1.161 ! andreas 1316: DBG(debug("input: len before de-compress %d",
! 1317: buffer_len(&active_state->incoming_packet)));
1.25 markus 1318: if (comp && comp->enabled) {
1.161 ! andreas 1319: buffer_clear(&active_state->compression_buffer);
! 1320: buffer_uncompress(&active_state->incoming_packet,
! 1321: &active_state->compression_buffer);
! 1322: buffer_clear(&active_state->incoming_packet);
! 1323: buffer_append(&active_state->incoming_packet,
! 1324: buffer_ptr(&active_state->compression_buffer),
! 1325: buffer_len(&active_state->compression_buffer));
1.97 deraadt 1326: DBG(debug("input: len after de-compress %d",
1.161 ! andreas 1327: buffer_len(&active_state->incoming_packet)));
1.25 markus 1328: }
1329: /*
1330: * get packet type, implies consume.
1331: * return length of payload (without type field)
1332: */
1.161 ! andreas 1333: type = buffer_get_char(&active_state->incoming_packet);
1.116 markus 1334: if (type < SSH2_MSG_MIN || type >= SSH2_MSG_LOCAL_MIN)
1335: packet_disconnect("Invalid ssh2 packet type: %d", type);
1.57 markus 1336: if (type == SSH2_MSG_NEWKEYS)
1337: set_newkeys(MODE_IN);
1.161 ! andreas 1338: else if (type == SSH2_MSG_USERAUTH_SUCCESS &&
! 1339: !active_state->server_side)
1.118 markus 1340: packet_enable_delayed_compress();
1.25 markus 1341: #ifdef PACKET_DEBUG
1.55 deraadt 1342: fprintf(stderr, "read/plain[%d]:\r\n", type);
1.161 ! andreas 1343: buffer_dump(&active_state->incoming_packet);
1.25 markus 1344: #endif
1.62 markus 1345: /* reset for next packet */
1.161 ! andreas 1346: active_state->packlen = 0;
1.62 markus 1347: return type;
1.25 markus 1348: }
1349:
1350: int
1.82 markus 1351: packet_read_poll_seqnr(u_int32_t *seqnr_p)
1.25 markus 1352: {
1.96 deraadt 1353: u_int reason, seqnr;
1.62 markus 1354: u_char type;
1.25 markus 1355: char *msg;
1.62 markus 1356:
1.25 markus 1357: for (;;) {
1.62 markus 1358: if (compat20) {
1.82 markus 1359: type = packet_read_poll2(seqnr_p);
1.153 djm 1360: if (type) {
1.161 ! andreas 1361: active_state->keep_alive_timeouts = 0;
1.25 markus 1362: DBG(debug("received packet type %d", type));
1.153 djm 1363: }
1.74 deraadt 1364: switch (type) {
1.150 dtucker 1365: case SSH2_MSG_IGNORE:
1.151 dtucker 1366: debug3("Received SSH2_MSG_IGNORE");
1.150 dtucker 1367: break;
1.25 markus 1368: case SSH2_MSG_DEBUG:
1369: packet_get_char();
1370: msg = packet_get_string(NULL);
1371: debug("Remote: %.900s", msg);
1372: xfree(msg);
1373: msg = packet_get_string(NULL);
1374: xfree(msg);
1375: break;
1376: case SSH2_MSG_DISCONNECT:
1377: reason = packet_get_int();
1378: msg = packet_get_string(NULL);
1.106 itojun 1379: logit("Received disconnect from %s: %u: %.400s",
1.96 deraadt 1380: get_remote_ipaddr(), reason, msg);
1.25 markus 1381: xfree(msg);
1.112 markus 1382: cleanup_exit(255);
1.84 markus 1383: break;
1384: case SSH2_MSG_UNIMPLEMENTED:
1385: seqnr = packet_get_int();
1.96 deraadt 1386: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1387: seqnr);
1.150 dtucker 1388: break;
1.25 markus 1389: default:
1390: return type;
1.48 stevesk 1391: }
1.25 markus 1392: } else {
1.82 markus 1393: type = packet_read_poll1();
1.74 deraadt 1394: switch (type) {
1.25 markus 1395: case SSH_MSG_IGNORE:
1396: break;
1397: case SSH_MSG_DEBUG:
1398: msg = packet_get_string(NULL);
1399: debug("Remote: %.900s", msg);
1400: xfree(msg);
1401: break;
1402: case SSH_MSG_DISCONNECT:
1403: msg = packet_get_string(NULL);
1.106 itojun 1404: logit("Received disconnect from %s: %.400s",
1.96 deraadt 1405: get_remote_ipaddr(), msg);
1.112 markus 1406: cleanup_exit(255);
1.25 markus 1407: break;
1408: default:
1.62 markus 1409: if (type)
1.25 markus 1410: DBG(debug("received packet type %d", type));
1411: return type;
1.48 stevesk 1412: }
1.25 markus 1413: }
1414: }
1.77 djm 1415: }
1416:
1417: int
1.82 markus 1418: packet_read_poll(void)
1.77 djm 1419: {
1.82 markus 1420: return packet_read_poll_seqnr(NULL);
1.25 markus 1421: }
1422:
1.16 markus 1423: /*
1424: * Buffers the given amount of input characters. This is intended to be used
1425: * together with packet_read_poll.
1426: */
1.1 deraadt 1427:
1.2 provos 1428: void
1.40 markus 1429: packet_process_incoming(const char *buf, u_int len)
1.1 deraadt 1430: {
1.161 ! andreas 1431: if (active_state->packet_discard) {
! 1432: active_state->keep_alive_timeouts = 0; /* ?? */
! 1433: if (len >= active_state->packet_discard)
1.159 markus 1434: packet_stop_discard();
1.161 ! andreas 1435: active_state->packet_discard -= len;
1.159 markus 1436: return;
1437: }
1.161 ! andreas 1438: buffer_append(&active_state->input, buf, len);
1.1 deraadt 1439: }
1440:
1441: /* Returns a character from the packet. */
1442:
1.40 markus 1443: u_int
1.73 itojun 1444: packet_get_char(void)
1.1 deraadt 1445: {
1.14 markus 1446: char ch;
1.97 deraadt 1447:
1.161 ! andreas 1448: buffer_get(&active_state->incoming_packet, &ch, 1);
1.40 markus 1449: return (u_char) ch;
1.1 deraadt 1450: }
1451:
1452: /* Returns an integer from the packet data. */
1453:
1.40 markus 1454: u_int
1.73 itojun 1455: packet_get_int(void)
1.1 deraadt 1456: {
1.161 ! andreas 1457: return buffer_get_int(&active_state->incoming_packet);
1.1 deraadt 1458: }
1459:
1.16 markus 1460: /*
1461: * Returns an arbitrary precision integer from the packet data. The integer
1462: * must have been initialized before this call.
1463: */
1.1 deraadt 1464:
1.2 provos 1465: void
1.80 markus 1466: packet_get_bignum(BIGNUM * value)
1.1 deraadt 1467: {
1.161 ! andreas 1468: buffer_get_bignum(&active_state->incoming_packet, value);
1.24 markus 1469: }
1470:
1471: void
1.80 markus 1472: packet_get_bignum2(BIGNUM * value)
1.24 markus 1473: {
1.161 ! andreas 1474: buffer_get_bignum2(&active_state->incoming_packet, value);
1.24 markus 1475: }
1476:
1.76 stevesk 1477: void *
1.117 djm 1478: packet_get_raw(u_int *length_ptr)
1.24 markus 1479: {
1.161 ! andreas 1480: u_int bytes = buffer_len(&active_state->incoming_packet);
1.97 deraadt 1481:
1.24 markus 1482: if (length_ptr != NULL)
1483: *length_ptr = bytes;
1.161 ! andreas 1484: return buffer_ptr(&active_state->incoming_packet);
1.28 markus 1485: }
1486:
1487: int
1488: packet_remaining(void)
1489: {
1.161 ! andreas 1490: return buffer_len(&active_state->incoming_packet);
1.1 deraadt 1491: }
1492:
1.16 markus 1493: /*
1494: * Returns a string from the packet data. The string is allocated using
1495: * xmalloc; it is the responsibility of the calling program to free it when
1496: * no longer needed. The length_ptr argument may be NULL, or point to an
1497: * integer into which the length of the string is stored.
1498: */
1.1 deraadt 1499:
1.76 stevesk 1500: void *
1.40 markus 1501: packet_get_string(u_int *length_ptr)
1.1 deraadt 1502: {
1.161 ! andreas 1503: return buffer_get_string(&active_state->incoming_packet, length_ptr);
1.152 markus 1504: }
1505:
1506: void *
1507: packet_get_string_ptr(u_int *length_ptr)
1508: {
1.161 ! andreas 1509: return buffer_get_string_ptr(&active_state->incoming_packet, length_ptr);
1.1 deraadt 1510: }
1511:
1.16 markus 1512: /*
1513: * Sends a diagnostic message from the server to the client. This message
1514: * can be sent at any time (but not while constructing another message). The
1515: * message is printed immediately, but only if the client is being executed
1516: * in verbose mode. These messages are primarily intended to ease debugging
1517: * authentication problems. The length of the formatted message must not
1518: * exceed 1024 bytes. This will automatically call packet_write_wait.
1519: */
1.1 deraadt 1520:
1.2 provos 1521: void
1.14 markus 1522: packet_send_debug(const char *fmt,...)
1.1 deraadt 1523: {
1.14 markus 1524: char buf[1024];
1525: va_list args;
1.39 markus 1526:
1527: if (compat20 && (datafellows & SSH_BUG_DEBUG))
1528: return;
1.14 markus 1529:
1530: va_start(args, fmt);
1531: vsnprintf(buf, sizeof(buf), fmt, args);
1532: va_end(args);
1533:
1.30 markus 1534: if (compat20) {
1535: packet_start(SSH2_MSG_DEBUG);
1536: packet_put_char(0); /* bool: always display */
1537: packet_put_cstring(buf);
1538: packet_put_cstring("");
1539: } else {
1540: packet_start(SSH_MSG_DEBUG);
1541: packet_put_cstring(buf);
1542: }
1.14 markus 1543: packet_send();
1544: packet_write_wait();
1.1 deraadt 1545: }
1546:
1.16 markus 1547: /*
1548: * Logs the error plus constructs and sends a disconnect packet, closes the
1549: * connection, and exits. This function never returns. The error message
1550: * should not contain a newline. The length of the formatted message must
1551: * not exceed 1024 bytes.
1552: */
1.1 deraadt 1553:
1.2 provos 1554: void
1.14 markus 1555: packet_disconnect(const char *fmt,...)
1.1 deraadt 1556: {
1.14 markus 1557: char buf[1024];
1558: va_list args;
1559: static int disconnecting = 0;
1.97 deraadt 1560:
1.14 markus 1561: if (disconnecting) /* Guard against recursive invocations. */
1562: fatal("packet_disconnect called recursively.");
1563: disconnecting = 1;
1564:
1.16 markus 1565: /*
1566: * Format the message. Note that the caller must make sure the
1567: * message is of limited size.
1568: */
1.14 markus 1569: va_start(args, fmt);
1570: vsnprintf(buf, sizeof(buf), fmt, args);
1571: va_end(args);
1572:
1.99 markus 1573: /* Display the error locally */
1.106 itojun 1574: logit("Disconnecting: %.100s", buf);
1.99 markus 1575:
1.14 markus 1576: /* Send the disconnect message to the other side, and wait for it to get sent. */
1.25 markus 1577: if (compat20) {
1578: packet_start(SSH2_MSG_DISCONNECT);
1579: packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR);
1580: packet_put_cstring(buf);
1581: packet_put_cstring("");
1582: } else {
1583: packet_start(SSH_MSG_DISCONNECT);
1.65 markus 1584: packet_put_cstring(buf);
1.25 markus 1585: }
1.14 markus 1586: packet_send();
1587: packet_write_wait();
1588:
1589: /* Stop listening for connections. */
1.67 markus 1590: channel_close_all();
1.14 markus 1591:
1592: /* Close the connection. */
1593: packet_close();
1.112 markus 1594: cleanup_exit(255);
1.1 deraadt 1595: }
1596:
1.16 markus 1597: /* Checks if there is any buffered output, and tries to write some of the output. */
1.1 deraadt 1598:
1.2 provos 1599: void
1.73 itojun 1600: packet_write_poll(void)
1.1 deraadt 1601: {
1.161 ! andreas 1602: int len = buffer_len(&active_state->output);
1.97 deraadt 1603:
1.14 markus 1604: if (len > 0) {
1.161 ! andreas 1605: len = write(active_state->connection_out,
! 1606: buffer_ptr(&active_state->output), len);
1.156 djm 1607: if (len == -1) {
1608: if (errno == EINTR || errno == EAGAIN)
1.14 markus 1609: return;
1.156 djm 1610: fatal("Write failed: %.100s", strerror(errno));
1.14 markus 1611: }
1.156 djm 1612: if (len == 0)
1613: fatal("Write connection closed");
1.161 ! andreas 1614: buffer_consume(&active_state->output, len);
1.14 markus 1615: }
1.1 deraadt 1616: }
1617:
1.16 markus 1618: /*
1619: * Calls packet_write_poll repeatedly until all pending output data has been
1620: * written.
1621: */
1.1 deraadt 1622:
1.2 provos 1623: void
1.73 itojun 1624: packet_write_wait(void)
1.1 deraadt 1625: {
1.56 millert 1626: fd_set *setp;
1.154 dtucker 1627: int ret, ms_remain;
1628: struct timeval start, timeout, *timeoutp = NULL;
1.56 millert 1629:
1.161 ! andreas 1630: setp = (fd_set *)xcalloc(howmany(active_state->connection_out + 1,
! 1631: NFDBITS), sizeof(fd_mask));
1.14 markus 1632: packet_write_poll();
1633: while (packet_have_data_to_write()) {
1.161 ! andreas 1634: memset(setp, 0, howmany(active_state->connection_out + 1,
! 1635: NFDBITS) * sizeof(fd_mask));
! 1636: FD_SET(active_state->connection_out, setp);
1.154 dtucker 1637:
1.161 ! andreas 1638: if (active_state->packet_timeout_ms > 0) {
! 1639: ms_remain = active_state->packet_timeout_ms;
1.154 dtucker 1640: timeoutp = &timeout;
1641: }
1642: for (;;) {
1.161 ! andreas 1643: if (active_state->packet_timeout_ms != -1) {
1.154 dtucker 1644: ms_to_timeval(&timeout, ms_remain);
1645: gettimeofday(&start, NULL);
1646: }
1.161 ! andreas 1647: if ((ret = select(active_state->connection_out + 1,
! 1648: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1649: break;
1.161 ! andreas 1650: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1651: break;
1.161 ! andreas 1652: if (active_state->packet_timeout_ms == -1)
1.154 dtucker 1653: continue;
1654: ms_subtract_diff(&start, &ms_remain);
1655: if (ms_remain <= 0) {
1656: ret = 0;
1657: break;
1658: }
1659: }
1660: if (ret == 0) {
1661: logit("Connection to %.200s timed out while "
1662: "waiting to write", get_remote_ipaddr());
1663: cleanup_exit(255);
1664: }
1.14 markus 1665: packet_write_poll();
1666: }
1.56 millert 1667: xfree(setp);
1.1 deraadt 1668: }
1669:
1670: /* Returns true if there is buffered data to write to the connection. */
1671:
1.2 provos 1672: int
1.73 itojun 1673: packet_have_data_to_write(void)
1.1 deraadt 1674: {
1.161 ! andreas 1675: return buffer_len(&active_state->output) != 0;
1.1 deraadt 1676: }
1677:
1678: /* Returns true if there is not too much data to write to the connection. */
1679:
1.2 provos 1680: int
1.73 itojun 1681: packet_not_very_much_data_to_write(void)
1.1 deraadt 1682: {
1.161 ! andreas 1683: if (active_state->interactive_mode)
! 1684: return buffer_len(&active_state->output) < 16384;
1.14 markus 1685: else
1.161 ! andreas 1686: return buffer_len(&active_state->output) < 128 * 1024;
1.1 deraadt 1687: }
1688:
1.102 markus 1689: static void
1.101 markus 1690: packet_set_tos(int interactive)
1691: {
1692: int tos = interactive ? IPTOS_LOWDELAY : IPTOS_THROUGHPUT;
1693:
1694: if (!packet_connection_is_on_socket() ||
1695: !packet_connection_is_ipv4())
1696: return;
1.161 ! andreas 1697: if (setsockopt(active_state->connection_in, IPPROTO_IP, IP_TOS, &tos,
1.101 markus 1698: sizeof(tos)) < 0)
1699: error("setsockopt IP_TOS %d: %.100s:",
1700: tos, strerror(errno));
1701: }
1702:
1.1 deraadt 1703: /* Informs that the current session is interactive. Sets IP flags for that. */
1704:
1.2 provos 1705: void
1.43 markus 1706: packet_set_interactive(int interactive)
1.1 deraadt 1707: {
1.43 markus 1708: static int called = 0;
1.44 markus 1709:
1.43 markus 1710: if (called)
1711: return;
1712: called = 1;
1.1 deraadt 1713:
1.14 markus 1714: /* Record that we are in interactive mode. */
1.161 ! andreas 1715: active_state->interactive_mode = interactive;
1.1 deraadt 1716:
1.19 markus 1717: /* Only set socket options if using a socket. */
1718: if (!packet_connection_is_on_socket())
1.14 markus 1719: return;
1.161 ! andreas 1720: set_nodelay(active_state->connection_in);
1.101 markus 1721: packet_set_tos(interactive);
1.1 deraadt 1722: }
1723:
1724: /* Returns true if the current connection is interactive. */
1725:
1.2 provos 1726: int
1.73 itojun 1727: packet_is_interactive(void)
1.1 deraadt 1728: {
1.161 ! andreas 1729: return active_state->interactive_mode;
1.12 markus 1730: }
1731:
1.113 deraadt 1732: int
1.108 markus 1733: packet_set_maxsize(u_int s)
1.12 markus 1734: {
1.14 markus 1735: static int called = 0;
1.97 deraadt 1736:
1.14 markus 1737: if (called) {
1.106 itojun 1738: logit("packet_set_maxsize: called twice: old %d new %d",
1.161 ! andreas 1739: active_state->max_packet_size, s);
1.14 markus 1740: return -1;
1741: }
1742: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 1743: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 1744: return -1;
1745: }
1.70 markus 1746: called = 1;
1.66 markus 1747: debug("packet_set_maxsize: setting to %d", s);
1.161 ! andreas 1748: active_state->max_packet_size = s;
1.14 markus 1749: return s;
1.53 markus 1750: }
1751:
1.161 ! andreas 1752: int
! 1753: packet_inc_alive_timeouts(void)
! 1754: {
! 1755: return ++active_state->keep_alive_timeouts;
! 1756: }
! 1757:
! 1758: void
! 1759: packet_set_alive_timeouts(int ka)
! 1760: {
! 1761: active_state->keep_alive_timeouts = ka;
! 1762: }
! 1763:
! 1764: u_int
! 1765: packet_get_maxsize(void)
! 1766: {
! 1767: return active_state->max_packet_size;
! 1768: }
! 1769:
1.71 markus 1770: /* roundup current message to pad bytes */
1771: void
1772: packet_add_padding(u_char pad)
1773: {
1.161 ! andreas 1774: active_state->extra_pad = pad;
1.71 markus 1775: }
1776:
1.53 markus 1777: /*
1778: * 9.2. Ignored Data Message
1.61 markus 1779: *
1.53 markus 1780: * byte SSH_MSG_IGNORE
1781: * string data
1.61 markus 1782: *
1.53 markus 1783: * All implementations MUST understand (and ignore) this message at any
1784: * time (after receiving the protocol version). No implementation is
1785: * required to send them. This message can be used as an additional
1786: * protection measure against advanced traffic analysis techniques.
1787: */
1.54 markus 1788: void
1789: packet_send_ignore(int nbytes)
1790: {
1.115 avsm 1791: u_int32_t rnd = 0;
1.54 markus 1792: int i;
1793:
1794: packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE);
1.53 markus 1795: packet_put_int(nbytes);
1.75 deraadt 1796: for (i = 0; i < nbytes; i++) {
1.53 markus 1797: if (i % 4 == 0)
1.115 avsm 1798: rnd = arc4random();
1.129 deraadt 1799: packet_put_char((u_char)rnd & 0xff);
1.115 avsm 1800: rnd >>= 8;
1.53 markus 1801: }
1.105 markus 1802: }
1803:
1.113 deraadt 1804: #define MAX_PACKETS (1U<<31)
1.105 markus 1805: int
1806: packet_need_rekeying(void)
1807: {
1808: if (datafellows & SSH_BUG_NOREKEY)
1809: return 0;
1810: return
1.161 ! andreas 1811: (active_state->p_send.packets > MAX_PACKETS) ||
! 1812: (active_state->p_read.packets > MAX_PACKETS) ||
! 1813: (active_state->max_blocks_out &&
! 1814: (active_state->p_send.blocks > active_state->max_blocks_out)) ||
! 1815: (active_state->max_blocks_in &&
! 1816: (active_state->p_read.blocks > active_state->max_blocks_in));
1.105 markus 1817: }
1818:
1819: void
1820: packet_set_rekey_limit(u_int32_t bytes)
1821: {
1.161 ! andreas 1822: active_state->rekey_limit = bytes;
1.118 markus 1823: }
1824:
1825: void
1826: packet_set_server(void)
1827: {
1.161 ! andreas 1828: active_state->server_side = 1;
1.118 markus 1829: }
1830:
1831: void
1832: packet_set_authenticated(void)
1833: {
1.161 ! andreas 1834: active_state->after_authentication = 1;
! 1835: }
! 1836:
! 1837: void *
! 1838: packet_get_input(void)
! 1839: {
! 1840: return (void *)&active_state->input;
! 1841: }
! 1842:
! 1843: void *
! 1844: packet_get_output(void)
! 1845: {
! 1846: return (void *)&active_state->output;
! 1847: }
! 1848:
! 1849: void *
! 1850: packet_get_newkeys(int mode)
! 1851: {
! 1852: return (void *)active_state->newkeys[mode];
1.1 deraadt 1853: }
![[BACK]](/icons/back.gif){kind=icon}
Return to packet.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh