Annotation of src/usr.bin/ssh/packet.c, Revision 1.230
1.230 ! djm 1: /* $OpenBSD: packet.c,v 1.229 2016/02/17 22:20:14 djm Exp $ */
1.1 deraadt 2: /*
1.15 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.35 deraadt 6: * This file contains code implementing the packet protocol and communication
7: * with the other side. This same code is used both on client and server side.
1.29 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
1.29 markus 14: *
1.25 markus 15: *
16: * SSH2 packet format added by Markus Friedl.
1.69 markus 17: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.25 markus 18: *
1.35 deraadt 19: * Redistribution and use in source and binary forms, with or without
20: * modification, are permitted provided that the following conditions
21: * are met:
22: * 1. Redistributions of source code must retain the above copyright
23: * notice, this list of conditions and the following disclaimer.
24: * 2. Redistributions in binary form must reproduce the above copyright
25: * notice, this list of conditions and the following disclaimer in the
26: * documentation and/or other materials provided with the distribution.
27: *
28: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15 deraadt 38: */
1.1 deraadt 39:
1.203 deraadt 40: #include <sys/param.h> /* MIN roundup */
1.142 deraadt 41: #include <sys/types.h>
1.105 markus 42: #include <sys/queue.h>
1.132 stevesk 43: #include <sys/socket.h>
1.138 stevesk 44: #include <sys/time.h>
1.132 stevesk 45: #include <netinet/in.h>
1.121 stevesk 46: #include <netinet/ip.h>
1.134 stevesk 47:
1.135 stevesk 48: #include <errno.h>
1.230 ! djm 49: #include <netdb.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>
1.203 deraadt 55: #include <limits.h>
1.142 deraadt 56: #include <signal.h>
1.184 dtucker 57: #include <time.h>
1.1 deraadt 58:
1.201 markus 59: #include <zlib.h>
60:
61: #include "buffer.h" /* typedefs XXX */
62: #include "key.h" /* typedefs XXX */
63:
1.1 deraadt 64: #include "xmalloc.h"
65: #include "crc32.h"
1.9 dugsong 66: #include "deattack.h"
1.25 markus 67: #include "compat.h"
1.45 markus 68: #include "ssh1.h"
1.25 markus 69: #include "ssh2.h"
1.37 markus 70: #include "cipher.h"
1.201 markus 71: #include "sshkey.h"
1.25 markus 72: #include "kex.h"
1.200 markus 73: #include "digest.h"
1.50 markus 74: #include "mac.h"
1.46 markus 75: #include "log.h"
76: #include "canohost.h"
1.87 stevesk 77: #include "misc.h"
1.198 millert 78: #include "channels.h"
1.95 markus 79: #include "ssh.h"
1.201 markus 80: #include "packet.h"
1.197 djm 81: #include "ssherr.h"
1.201 markus 82: #include "sshbuf.h"
1.25 markus 83:
84: #ifdef PACKET_DEBUG
85: #define DBG(x) x
86: #else
87: #define DBG(x)
88: #endif
89:
1.159 markus 90: #define PACKET_MAX_SIZE (256 * 1024)
91:
1.161 andreas 92: struct packet_state {
93: u_int32_t seqnr;
94: u_int32_t packets;
95: u_int64_t blocks;
96: u_int64_t bytes;
97: };
98:
99: struct packet {
100: TAILQ_ENTRY(packet) next;
101: u_char type;
1.201 markus 102: struct sshbuf *payload;
1.161 andreas 103: };
104:
105: struct session_state {
106: /*
107: * This variable contains the file descriptors used for
108: * communicating with the other side. connection_in is used for
109: * reading; connection_out for writing. These can be the same
110: * descriptor, in which case it is assumed to be a socket.
111: */
112: int connection_in;
113: int connection_out;
114:
115: /* Protocol flags for the remote side. */
116: u_int remote_protocol_flags;
1.1 deraadt 117:
1.161 andreas 118: /* Encryption context for receiving data. Only used for decryption. */
1.201 markus 119: struct sshcipher_ctx receive_context;
1.1 deraadt 120:
1.161 andreas 121: /* Encryption context for sending data. Only used for encryption. */
1.201 markus 122: struct sshcipher_ctx send_context;
1.14 markus 123:
1.161 andreas 124: /* Buffer for raw input data from the socket. */
1.201 markus 125: struct sshbuf *input;
1.1 deraadt 126:
1.161 andreas 127: /* Buffer for raw output data going to the socket. */
1.201 markus 128: struct sshbuf *output;
1.1 deraadt 129:
1.161 andreas 130: /* Buffer for the partial outgoing packet being constructed. */
1.201 markus 131: struct sshbuf *outgoing_packet;
1.1 deraadt 132:
1.161 andreas 133: /* Buffer for the incoming packet currently being processed. */
1.201 markus 134: struct sshbuf *incoming_packet;
1.1 deraadt 135:
1.161 andreas 136: /* Scratch buffer for packet compression/decompression. */
1.201 markus 137: struct sshbuf *compression_buffer;
138:
139: /* Incoming/outgoing compression dictionaries */
140: z_stream compression_in_stream;
141: z_stream compression_out_stream;
142: int compression_in_started;
143: int compression_out_started;
144: int compression_in_failures;
145: int compression_out_failures;
1.1 deraadt 146:
1.161 andreas 147: /*
148: * Flag indicating whether packet compression/decompression is
149: * enabled.
150: */
151: int packet_compression;
1.1 deraadt 152:
1.161 andreas 153: /* default maximum packet size */
154: u_int max_packet_size;
1.1 deraadt 155:
1.161 andreas 156: /* Flag indicating whether this module has been initialized. */
157: int initialized;
1.12 markus 158:
1.161 andreas 159: /* Set to true if the connection is interactive. */
160: int interactive_mode;
1.1 deraadt 161:
1.161 andreas 162: /* Set to true if we are the server side. */
163: int server_side;
1.1 deraadt 164:
1.161 andreas 165: /* Set to true if we are authenticated. */
166: int after_authentication;
1.118 markus 167:
1.161 andreas 168: int keep_alive_timeouts;
1.118 markus 169:
1.161 andreas 170: /* The maximum time that we will wait to send or receive a packet */
171: int packet_timeout_ms;
1.151 dtucker 172:
1.161 andreas 173: /* Session key information for Encryption and MAC */
1.201 markus 174: struct newkeys *newkeys[MODE_MAX];
1.161 andreas 175: struct packet_state p_read, p_send;
1.154 dtucker 176:
1.184 dtucker 177: /* Volume-based rekeying */
1.224 dtucker 178: u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
1.105 markus 179:
1.184 dtucker 180: /* Time-based rekeying */
1.208 markus 181: u_int32_t rekey_interval; /* how often in seconds */
1.184 dtucker 182: time_t rekey_time; /* time of last rekeying */
183:
1.161 andreas 184: /* Session key for protocol v1 */
185: u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
186: u_int ssh1_keylen;
1.25 markus 187:
1.161 andreas 188: /* roundup current message to extra_pad bytes */
189: u_char extra_pad;
1.95 markus 190:
1.161 andreas 191: /* XXX discard incoming data after MAC error */
192: u_int packet_discard;
1.201 markus 193: struct sshmac *packet_discard_mac;
1.71 markus 194:
1.161 andreas 195: /* Used in packet_read_poll2() */
196: u_int packlen;
1.159 markus 197:
1.165 andreas 198: /* Used in packet_send2 */
199: int rekeying;
200:
201: /* Used in packet_set_interactive */
202: int set_interactive_called;
203:
204: /* Used in packet_set_maxsize */
205: int set_maxsize_called;
206:
1.201 markus 207: /* One-off warning about weak ciphers */
208: int cipher_warning_done;
209:
210: /* SSH1 CRC compensation attack detector */
211: struct deattack_ctx deattack;
212:
1.161 andreas 213: TAILQ_HEAD(, packet) outgoing;
1.105 markus 214: };
1.161 andreas 215:
1.201 markus 216: struct ssh *
217: ssh_alloc_session_state(void)
1.161 andreas 218: {
1.201 markus 219: struct ssh *ssh = NULL;
220: struct session_state *state = NULL;
1.161 andreas 221:
1.201 markus 222: if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
223: (state = calloc(1, sizeof(*state))) == NULL ||
224: (state->input = sshbuf_new()) == NULL ||
225: (state->output = sshbuf_new()) == NULL ||
226: (state->outgoing_packet = sshbuf_new()) == NULL ||
227: (state->incoming_packet = sshbuf_new()) == NULL)
228: goto fail;
229: TAILQ_INIT(&state->outgoing);
1.202 markus 230: TAILQ_INIT(&ssh->private_keys);
231: TAILQ_INIT(&ssh->public_keys);
1.201 markus 232: state->connection_in = -1;
233: state->connection_out = -1;
234: state->max_packet_size = 32768;
235: state->packet_timeout_ms = -1;
236: state->p_send.packets = state->p_read.packets = 0;
237: state->initialized = 1;
238: /*
239: * ssh_packet_send2() needs to queue packets until
240: * we've done the initial key exchange.
241: */
242: state->rekeying = 1;
243: ssh->state = state;
244: return ssh;
245: fail:
246: if (state) {
247: sshbuf_free(state->input);
248: sshbuf_free(state->output);
249: sshbuf_free(state->incoming_packet);
250: sshbuf_free(state->outgoing_packet);
251: free(state);
252: }
253: free(ssh);
254: return NULL;
1.161 andreas 255: }
1.105 markus 256:
1.228 djm 257: /* Returns nonzero if rekeying is in progress */
258: int
259: ssh_packet_is_rekeying(struct ssh *ssh)
260: {
1.229 djm 261: return compat20 &&
262: (ssh->state->rekeying || (ssh->kex != NULL && ssh->kex->done == 0));
1.228 djm 263: }
264:
1.16 markus 265: /*
266: * Sets the descriptors used for communication. Disables encryption until
267: * packet_set_encryption_key is called.
268: */
1.201 markus 269: struct ssh *
270: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1 deraadt 271: {
1.201 markus 272: struct session_state *state;
273: const struct sshcipher *none = cipher_by_name("none");
1.197 djm 274: int r;
1.97 deraadt 275:
1.205 djm 276: if (none == NULL) {
277: error("%s: cannot load cipher 'none'", __func__);
278: return NULL;
279: }
1.201 markus 280: if (ssh == NULL)
281: ssh = ssh_alloc_session_state();
1.205 djm 282: if (ssh == NULL) {
283: error("%s: cound not allocate state", __func__);
284: return NULL;
285: }
1.201 markus 286: state = ssh->state;
287: state->connection_in = fd_in;
288: state->connection_out = fd_out;
289: if ((r = cipher_init(&state->send_context, none,
1.197 djm 290: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201 markus 291: (r = cipher_init(&state->receive_context, none,
1.205 djm 292: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
293: error("%s: cipher_init failed: %s", __func__, ssh_err(r));
1.230 ! djm 294: free(ssh); /* XXX need ssh_free_session_state? */
1.205 djm 295: return NULL;
296: }
1.201 markus 297: state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
298: deattack_init(&state->deattack);
1.207 djm 299: /*
300: * Cache the IP address of the remote connection for use in error
301: * messages that might be generated after the connection has closed.
302: */
303: (void)ssh_remote_ipaddr(ssh);
1.201 markus 304: return ssh;
1.1 deraadt 305: }
306:
1.154 dtucker 307: void
1.201 markus 308: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 309: {
1.201 markus 310: struct session_state *state = ssh->state;
311:
1.174 djm 312: if (timeout <= 0 || count <= 0) {
1.201 markus 313: state->packet_timeout_ms = -1;
1.154 dtucker 314: return;
315: }
316: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 317: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 318: else
1.201 markus 319: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 320: }
321:
1.201 markus 322: int
323: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 324: {
1.201 markus 325: struct session_state *state = ssh->state;
326: int r;
327:
328: if (state->packet_discard_mac) {
1.159 markus 329: char buf[1024];
1.201 markus 330:
1.159 markus 331: memset(buf, 'a', sizeof(buf));
1.201 markus 332: while (sshbuf_len(state->incoming_packet) <
1.161 andreas 333: PACKET_MAX_SIZE)
1.201 markus 334: if ((r = sshbuf_put(state->incoming_packet, buf,
335: sizeof(buf))) != 0)
336: return r;
337: (void) mac_compute(state->packet_discard_mac,
338: state->p_read.seqnr,
339: sshbuf_ptr(state->incoming_packet), PACKET_MAX_SIZE,
340: NULL, 0);
1.159 markus 341: }
1.220 djm 342: logit("Finished discarding for %.200s port %d",
343: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 344: return SSH_ERR_MAC_INVALID;
1.159 markus 345: }
346:
1.201 markus 347: static int
348: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
349: struct sshmac *mac, u_int packet_length, u_int discard)
1.159 markus 350: {
1.201 markus 351: struct session_state *state = ssh->state;
352: int r;
353:
354: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
355: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
356: return r;
357: return SSH_ERR_MAC_INVALID;
358: }
1.159 markus 359: if (packet_length != PACKET_MAX_SIZE && mac && mac->enabled)
1.201 markus 360: state->packet_discard_mac = mac;
361: if (sshbuf_len(state->input) >= discard &&
362: (r = ssh_packet_stop_discard(ssh)) != 0)
363: return r;
364: state->packet_discard = discard - sshbuf_len(state->input);
365: return 0;
1.159 markus 366: }
367:
1.19 markus 368: /* Returns 1 if remote host is connected via socket, 0 if not. */
369:
370: int
1.201 markus 371: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 372: {
1.201 markus 373: struct session_state *state = ssh->state;
1.19 markus 374: struct sockaddr_storage from, to;
375: socklen_t fromlen, tolen;
376:
1.230 ! djm 377: if (state->connection_in == -1 || state->connection_out == -1)
! 378: return 0;
! 379:
1.19 markus 380: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 381: if (state->connection_in == state->connection_out)
1.19 markus 382: return 1;
383: fromlen = sizeof(from);
384: memset(&from, 0, sizeof(from));
1.201 markus 385: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.161 andreas 386: &fromlen) < 0)
1.19 markus 387: return 0;
388: tolen = sizeof(to);
389: memset(&to, 0, sizeof(to));
1.201 markus 390: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.161 andreas 391: &tolen) < 0)
1.19 markus 392: return 0;
393: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
394: return 0;
395: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
396: return 0;
397: return 1;
398: }
399:
1.91 markus 400: void
1.201 markus 401: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 402: {
1.201 markus 403: if (ibytes)
404: *ibytes = ssh->state->p_read.bytes;
405: if (obytes)
406: *obytes = ssh->state->p_send.bytes;
1.91 markus 407: }
1.125 deraadt 408:
1.91 markus 409: int
1.201 markus 410: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 411: {
412: struct sockaddr_storage to;
1.21 deraadt 413: socklen_t tolen = sizeof(to);
1.19 markus 414:
415: memset(&to, 0, sizeof(to));
1.201 markus 416: if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
1.161 andreas 417: &tolen) < 0)
1.19 markus 418: return 0;
1.173 djm 419: return to.ss_family;
1.19 markus 420: }
421:
1.1 deraadt 422: /* Sets the connection into non-blocking mode. */
423:
1.2 provos 424: void
1.201 markus 425: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 426: {
1.14 markus 427: /* Set the socket into non-blocking mode. */
1.201 markus 428: set_nonblock(ssh->state->connection_in);
1.14 markus 429:
1.201 markus 430: if (ssh->state->connection_out != ssh->state->connection_in)
431: set_nonblock(ssh->state->connection_out);
1.1 deraadt 432: }
433:
434: /* Returns the socket used for reading. */
435:
1.2 provos 436: int
1.201 markus 437: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 438: {
1.201 markus 439: return ssh->state->connection_in;
1.1 deraadt 440: }
441:
442: /* Returns the descriptor used for writing. */
443:
1.2 provos 444: int
1.201 markus 445: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 446: {
1.201 markus 447: return ssh->state->connection_out;
448: }
449:
450: /*
451: * Returns the IP-address of the remote host as a string. The returned
452: * string must not be freed.
453: */
454:
455: const char *
456: ssh_remote_ipaddr(struct ssh *ssh)
457: {
1.220 djm 458: const int sock = ssh->state->connection_in;
459:
1.201 markus 460: /* Check whether we have cached the ipaddr. */
1.220 djm 461: if (ssh->remote_ipaddr == NULL) {
462: if (ssh_packet_connection_is_on_socket(ssh)) {
463: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 ! djm 464: ssh->remote_port = get_peer_port(sock);
! 465: ssh->local_ipaddr = get_local_ipaddr(sock);
! 466: ssh->local_port = get_local_port(sock);
1.220 djm 467: } else {
468: ssh->remote_ipaddr = strdup("UNKNOWN");
1.230 ! djm 469: ssh->remote_port = 65535;
! 470: ssh->local_ipaddr = strdup("UNKNOWN");
! 471: ssh->local_port = 65535;
1.220 djm 472: }
473: }
1.201 markus 474: return ssh->remote_ipaddr;
1.1 deraadt 475: }
476:
1.220 djm 477: /* Returns the port number of the remote host. */
478:
479: int
480: ssh_remote_port(struct ssh *ssh)
481: {
482: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
483: return ssh->remote_port;
1.230 ! djm 484: }
! 485:
! 486: /*
! 487: * Returns the IP-address of the local host as a string. The returned
! 488: * string must not be freed.
! 489: */
! 490:
! 491: const char *
! 492: ssh_local_ipaddr(struct ssh *ssh)
! 493: {
! 494: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
! 495: return ssh->local_ipaddr;
! 496: }
! 497:
! 498: /* Returns the port number of the local host. */
! 499:
! 500: int
! 501: ssh_local_port(struct ssh *ssh)
! 502: {
! 503: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
! 504: return ssh->local_port;
1.220 djm 505: }
506:
1.1 deraadt 507: /* Closes the connection and clears and frees internal data structures. */
508:
1.2 provos 509: void
1.201 markus 510: ssh_packet_close(struct ssh *ssh)
1.1 deraadt 511: {
1.201 markus 512: struct session_state *state = ssh->state;
513: int r;
514: u_int mode;
515:
516: if (!state->initialized)
1.14 markus 517: return;
1.201 markus 518: state->initialized = 0;
519: if (state->connection_in == state->connection_out) {
520: shutdown(state->connection_out, SHUT_RDWR);
521: close(state->connection_out);
1.14 markus 522: } else {
1.201 markus 523: close(state->connection_in);
524: close(state->connection_out);
1.14 markus 525: }
1.201 markus 526: sshbuf_free(state->input);
527: sshbuf_free(state->output);
528: sshbuf_free(state->outgoing_packet);
529: sshbuf_free(state->incoming_packet);
530: for (mode = 0; mode < MODE_MAX; mode++)
531: kex_free_newkeys(state->newkeys[mode]);
532: if (state->compression_buffer) {
533: sshbuf_free(state->compression_buffer);
534: if (state->compression_out_started) {
535: z_streamp stream = &state->compression_out_stream;
536: debug("compress outgoing: "
537: "raw data %llu, compressed %llu, factor %.2f",
538: (unsigned long long)stream->total_in,
539: (unsigned long long)stream->total_out,
540: stream->total_in == 0 ? 0.0 :
541: (double) stream->total_out / stream->total_in);
542: if (state->compression_out_failures == 0)
543: deflateEnd(stream);
544: }
545: if (state->compression_in_started) {
546: z_streamp stream = &state->compression_out_stream;
547: debug("compress incoming: "
548: "raw data %llu, compressed %llu, factor %.2f",
549: (unsigned long long)stream->total_out,
550: (unsigned long long)stream->total_in,
551: stream->total_out == 0 ? 0.0 :
552: (double) stream->total_in / stream->total_out);
553: if (state->compression_in_failures == 0)
554: inflateEnd(stream);
555: }
1.14 markus 556: }
1.201 markus 557: if ((r = cipher_cleanup(&state->send_context)) != 0)
558: error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r));
559: if ((r = cipher_cleanup(&state->receive_context)) != 0)
560: error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r));
1.219 mmcc 561: free(ssh->remote_ipaddr);
562: ssh->remote_ipaddr = NULL;
1.201 markus 563: free(ssh->state);
564: ssh->state = NULL;
1.1 deraadt 565: }
566:
567: /* Sets remote side protocol flags. */
568:
1.2 provos 569: void
1.201 markus 570: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 571: {
1.201 markus 572: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 573: }
574:
575: /* Returns the remote protocol flags set earlier by the above function. */
576:
1.40 markus 577: u_int
1.201 markus 578: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 579: {
1.201 markus 580: return ssh->state->remote_protocol_flags;
1.1 deraadt 581: }
582:
1.16 markus 583: /*
584: * Starts packet compression from the next packet on in both directions.
585: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
586: */
1.1 deraadt 587:
1.201 markus 588: static int
589: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 590: {
1.201 markus 591: if (!ssh->state->compression_buffer &&
592: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
593: return SSH_ERR_ALLOC_FAIL;
594: return 0;
1.60 markus 595: }
596:
1.201 markus 597: static int
598: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 599: {
1.201 markus 600: if (level < 1 || level > 9)
601: return SSH_ERR_INVALID_ARGUMENT;
602: debug("Enabling compression at level %d.", level);
603: if (ssh->state->compression_out_started == 1)
604: deflateEnd(&ssh->state->compression_out_stream);
605: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
606: case Z_OK:
607: ssh->state->compression_out_started = 1;
608: break;
609: case Z_MEM_ERROR:
610: return SSH_ERR_ALLOC_FAIL;
611: default:
612: return SSH_ERR_INTERNAL_ERROR;
613: }
614: return 0;
1.1 deraadt 615: }
616:
1.201 markus 617: static int
618: start_compression_in(struct ssh *ssh)
619: {
620: if (ssh->state->compression_in_started == 1)
621: inflateEnd(&ssh->state->compression_in_stream);
622: switch (inflateInit(&ssh->state->compression_in_stream)) {
623: case Z_OK:
624: ssh->state->compression_in_started = 1;
625: break;
626: case Z_MEM_ERROR:
627: return SSH_ERR_ALLOC_FAIL;
628: default:
629: return SSH_ERR_INTERNAL_ERROR;
630: }
631: return 0;
632: }
1.95 markus 633:
1.201 markus 634: int
635: ssh_packet_start_compression(struct ssh *ssh, int level)
1.1 deraadt 636: {
1.197 djm 637: int r;
1.97 deraadt 638:
1.201 markus 639: if (ssh->state->packet_compression && !compat20)
640: return SSH_ERR_INTERNAL_ERROR;
641: ssh->state->packet_compression = 1;
642: if ((r = ssh_packet_init_compression(ssh)) != 0 ||
643: (r = start_compression_in(ssh)) != 0 ||
644: (r = start_compression_out(ssh, level)) != 0)
645: return r;
646: return 0;
1.95 markus 647: }
648:
1.201 markus 649: /* XXX remove need for separate compression buffer */
650: static int
651: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 652: {
1.201 markus 653: u_char buf[4096];
654: int r, status;
655:
656: if (ssh->state->compression_out_started != 1)
657: return SSH_ERR_INTERNAL_ERROR;
658:
659: /* This case is not handled below. */
660: if (sshbuf_len(in) == 0)
661: return 0;
662:
663: /* Input is the contents of the input buffer. */
664: if ((ssh->state->compression_out_stream.next_in =
665: sshbuf_mutable_ptr(in)) == NULL)
666: return SSH_ERR_INTERNAL_ERROR;
667: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
668:
669: /* Loop compressing until deflate() returns with avail_out != 0. */
670: do {
671: /* Set up fixed-size output buffer. */
672: ssh->state->compression_out_stream.next_out = buf;
673: ssh->state->compression_out_stream.avail_out = sizeof(buf);
674:
675: /* Compress as much data into the buffer as possible. */
676: status = deflate(&ssh->state->compression_out_stream,
677: Z_PARTIAL_FLUSH);
678: switch (status) {
679: case Z_MEM_ERROR:
680: return SSH_ERR_ALLOC_FAIL;
681: case Z_OK:
682: /* Append compressed data to output_buffer. */
683: if ((r = sshbuf_put(out, buf, sizeof(buf) -
684: ssh->state->compression_out_stream.avail_out)) != 0)
685: return r;
686: break;
687: case Z_STREAM_ERROR:
688: default:
689: ssh->state->compression_out_failures++;
690: return SSH_ERR_INVALID_FORMAT;
691: }
692: } while (ssh->state->compression_out_stream.avail_out == 0);
693: return 0;
1.1 deraadt 694: }
695:
1.201 markus 696: static int
697: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 698: {
1.201 markus 699: u_char buf[4096];
700: int r, status;
1.1 deraadt 701:
1.201 markus 702: if (ssh->state->compression_in_started != 1)
703: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 704:
1.201 markus 705: if ((ssh->state->compression_in_stream.next_in =
706: sshbuf_mutable_ptr(in)) == NULL)
707: return SSH_ERR_INTERNAL_ERROR;
708: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 709:
1.201 markus 710: for (;;) {
711: /* Set up fixed-size output buffer. */
712: ssh->state->compression_in_stream.next_out = buf;
713: ssh->state->compression_in_stream.avail_out = sizeof(buf);
714:
715: status = inflate(&ssh->state->compression_in_stream,
716: Z_PARTIAL_FLUSH);
717: switch (status) {
718: case Z_OK:
719: if ((r = sshbuf_put(out, buf, sizeof(buf) -
720: ssh->state->compression_in_stream.avail_out)) != 0)
721: return r;
722: break;
723: case Z_BUF_ERROR:
724: /*
725: * Comments in zlib.h say that we should keep calling
726: * inflate() until we get an error. This appears to
727: * be the error that we get.
728: */
729: return 0;
730: case Z_DATA_ERROR:
731: return SSH_ERR_INVALID_FORMAT;
732: case Z_MEM_ERROR:
733: return SSH_ERR_ALLOC_FAIL;
734: case Z_STREAM_ERROR:
735: default:
736: ssh->state->compression_in_failures++;
737: return SSH_ERR_INTERNAL_ERROR;
738: }
739: }
740: /* NOTREACHED */
1.1 deraadt 741: }
1.125 deraadt 742:
1.201 markus 743: /* Serialise compression state into a blob for privsep */
744: static int
745: ssh_packet_get_compress_state(struct sshbuf *m, struct ssh *ssh)
1.1 deraadt 746: {
1.201 markus 747: struct session_state *state = ssh->state;
748: struct sshbuf *b;
749: int r;
750:
751: if ((b = sshbuf_new()) == NULL)
752: return SSH_ERR_ALLOC_FAIL;
753: if (state->compression_in_started) {
754: if ((r = sshbuf_put_string(b, &state->compression_in_stream,
755: sizeof(state->compression_in_stream))) != 0)
756: goto out;
757: } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0)
758: goto out;
759: if (state->compression_out_started) {
760: if ((r = sshbuf_put_string(b, &state->compression_out_stream,
761: sizeof(state->compression_out_stream))) != 0)
762: goto out;
763: } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0)
764: goto out;
765: r = sshbuf_put_stringb(m, b);
766: out:
767: sshbuf_free(b);
768: return r;
1.1 deraadt 769: }
1.125 deraadt 770:
1.201 markus 771: /* Deserialise compression state from a blob for privsep */
772: static int
773: ssh_packet_set_compress_state(struct ssh *ssh, struct sshbuf *m)
1.162 andreas 774: {
1.201 markus 775: struct session_state *state = ssh->state;
776: struct sshbuf *b = NULL;
777: int r;
778: const u_char *inblob, *outblob;
779: size_t inl, outl;
1.162 andreas 780:
1.201 markus 781: if ((r = sshbuf_froms(m, &b)) != 0)
782: goto out;
783: if ((r = sshbuf_get_string_direct(b, &inblob, &inl)) != 0 ||
784: (r = sshbuf_get_string_direct(b, &outblob, &outl)) != 0)
785: goto out;
786: if (inl == 0)
787: state->compression_in_started = 0;
788: else if (inl != sizeof(state->compression_in_stream)) {
789: r = SSH_ERR_INTERNAL_ERROR;
790: goto out;
791: } else {
792: state->compression_in_started = 1;
793: memcpy(&state->compression_in_stream, inblob, inl);
794: }
795: if (outl == 0)
796: state->compression_out_started = 0;
797: else if (outl != sizeof(state->compression_out_stream)) {
798: r = SSH_ERR_INTERNAL_ERROR;
799: goto out;
800: } else {
801: state->compression_out_started = 1;
802: memcpy(&state->compression_out_stream, outblob, outl);
803: }
804: r = 0;
805: out:
806: sshbuf_free(b);
807: return r;
1.1 deraadt 808: }
1.125 deraadt 809:
1.24 markus 810: void
1.201 markus 811: ssh_packet_set_compress_hooks(struct ssh *ssh, void *ctx,
812: void *(*allocfunc)(void *, u_int, u_int),
813: void (*freefunc)(void *, void *))
814: {
815: ssh->state->compression_out_stream.zalloc = (alloc_func)allocfunc;
816: ssh->state->compression_out_stream.zfree = (free_func)freefunc;
817: ssh->state->compression_out_stream.opaque = ctx;
818: ssh->state->compression_in_stream.zalloc = (alloc_func)allocfunc;
819: ssh->state->compression_in_stream.zfree = (free_func)freefunc;
820: ssh->state->compression_in_stream.opaque = ctx;
1.24 markus 821: }
1.125 deraadt 822:
1.201 markus 823: /*
824: * Causes any further packets to be encrypted using the given key. The same
825: * key is used for both sending and reception. However, both directions are
826: * encrypted independently of each other.
827: */
1.125 deraadt 828:
1.2 provos 829: void
1.201 markus 830: ssh_packet_set_encryption_key(struct ssh *ssh, const u_char *key, u_int keylen, int number)
1.1 deraadt 831: {
1.211 djm 832: #ifndef WITH_SSH1
833: fatal("no SSH protocol 1 support");
834: #else /* WITH_SSH1 */
1.201 markus 835: struct session_state *state = ssh->state;
836: const struct sshcipher *cipher = cipher_by_number(number);
837: int r;
838: const char *wmsg;
1.125 deraadt 839:
1.201 markus 840: if (cipher == NULL)
841: fatal("%s: unknown cipher number %d", __func__, number);
842: if (keylen < 20)
843: fatal("%s: keylen too small: %d", __func__, keylen);
844: if (keylen > SSH_SESSION_KEY_LENGTH)
845: fatal("%s: keylen too big: %d", __func__, keylen);
846: memcpy(state->ssh1_key, key, keylen);
847: state->ssh1_keylen = keylen;
848: if ((r = cipher_init(&state->send_context, cipher, key, keylen,
849: NULL, 0, CIPHER_ENCRYPT)) != 0 ||
850: (r = cipher_init(&state->receive_context, cipher, key, keylen,
851: NULL, 0, CIPHER_DECRYPT) != 0))
852: fatal("%s: cipher_init failed: %s", __func__, ssh_err(r));
853: if (!state->cipher_warning_done &&
854: ((wmsg = cipher_warning_message(&state->send_context)) != NULL ||
855: (wmsg = cipher_warning_message(&state->send_context)) != NULL)) {
856: error("Warning: %s", wmsg);
857: state->cipher_warning_done = 1;
858: }
1.211 djm 859: #endif /* WITH_SSH1 */
1.170 djm 860: }
861:
1.16 markus 862: /*
863: * Finalizes and sends the packet. If the encryption key has been set,
864: * encrypts the packet before sending.
865: */
1.14 markus 866:
1.201 markus 867: int
868: ssh_packet_send1(struct ssh *ssh)
1.1 deraadt 869: {
1.201 markus 870: struct session_state *state = ssh->state;
1.89 markus 871: u_char buf[8], *cp;
1.201 markus 872: int r, padding, len;
1.40 markus 873: u_int checksum;
1.14 markus 874:
1.16 markus 875: /*
876: * If using packet compression, compress the payload of the outgoing
877: * packet.
878: */
1.201 markus 879: if (state->packet_compression) {
880: sshbuf_reset(state->compression_buffer);
1.14 markus 881: /* Skip padding. */
1.201 markus 882: if ((r = sshbuf_consume(state->outgoing_packet, 8)) != 0)
883: goto out;
1.14 markus 884: /* padding */
1.201 markus 885: if ((r = sshbuf_put(state->compression_buffer,
886: "\0\0\0\0\0\0\0\0", 8)) != 0)
887: goto out;
888: if ((r = compress_buffer(ssh, state->outgoing_packet,
889: state->compression_buffer)) != 0)
890: goto out;
891: sshbuf_reset(state->outgoing_packet);
892: if ((r = sshbuf_putb(state->outgoing_packet,
893: state->compression_buffer)) != 0)
894: goto out;
1.14 markus 895: }
896: /* Compute packet length without padding (add checksum, remove padding). */
1.201 markus 897: len = sshbuf_len(state->outgoing_packet) + 4 - 8;
1.14 markus 898:
1.32 markus 899: /* Insert padding. Initialized to zero in packet_start1() */
1.14 markus 900: padding = 8 - len % 8;
1.201 markus 901: if (!state->send_context.plaintext) {
902: cp = sshbuf_mutable_ptr(state->outgoing_packet);
903: if (cp == NULL) {
904: r = SSH_ERR_INTERNAL_ERROR;
905: goto out;
1.14 markus 906: }
1.201 markus 907: arc4random_buf(cp + 8 - padding, padding);
1.14 markus 908: }
1.201 markus 909: if ((r = sshbuf_consume(state->outgoing_packet, 8 - padding)) != 0)
910: goto out;
1.14 markus 911:
912: /* Add check bytes. */
1.201 markus 913: checksum = ssh_crc32(sshbuf_ptr(state->outgoing_packet),
914: sshbuf_len(state->outgoing_packet));
915: POKE_U32(buf, checksum);
916: if ((r = sshbuf_put(state->outgoing_packet, buf, 4)) != 0)
917: goto out;
1.1 deraadt 918:
919: #ifdef PACKET_DEBUG
1.14 markus 920: fprintf(stderr, "packet_send plain: ");
1.201 markus 921: sshbuf_dump(state->outgoing_packet, stderr);
1.1 deraadt 922: #endif
923:
1.14 markus 924: /* Append to output. */
1.201 markus 925: POKE_U32(buf, len);
926: if ((r = sshbuf_put(state->output, buf, 4)) != 0)
927: goto out;
928: if ((r = sshbuf_reserve(state->output,
929: sshbuf_len(state->outgoing_packet), &cp)) != 0)
930: goto out;
931: if ((r = cipher_crypt(&state->send_context, 0, cp,
932: sshbuf_ptr(state->outgoing_packet),
933: sshbuf_len(state->outgoing_packet), 0, 0)) != 0)
934: goto out;
1.14 markus 935:
1.1 deraadt 936: #ifdef PACKET_DEBUG
1.14 markus 937: fprintf(stderr, "encrypted: ");
1.201 markus 938: sshbuf_dump(state->output, stderr);
1.1 deraadt 939: #endif
1.201 markus 940: state->p_send.packets++;
941: state->p_send.bytes += len +
942: sshbuf_len(state->outgoing_packet);
943: sshbuf_reset(state->outgoing_packet);
1.1 deraadt 944:
1.16 markus 945: /*
1.120 djm 946: * Note that the packet is now only buffered in output. It won't be
1.205 djm 947: * actually sent until ssh_packet_write_wait or ssh_packet_write_poll
948: * is called.
1.16 markus 949: */
1.201 markus 950: r = 0;
951: out:
952: return r;
1.1 deraadt 953: }
954:
1.201 markus 955: int
956: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 957: {
1.201 markus 958: struct session_state *state = ssh->state;
959: struct sshenc *enc;
960: struct sshmac *mac;
961: struct sshcomp *comp;
962: struct sshcipher_ctx *cc;
1.105 markus 963: u_int64_t *max_blocks;
1.201 markus 964: const char *wmsg;
1.197 djm 965: int r, crypt_type;
1.57 markus 966:
1.100 markus 967: debug2("set_newkeys: mode %d", mode);
1.57 markus 968:
1.88 markus 969: if (mode == MODE_OUT) {
1.201 markus 970: cc = &state->send_context;
1.115 avsm 971: crypt_type = CIPHER_ENCRYPT;
1.201 markus 972: state->p_send.packets = state->p_send.blocks = 0;
973: max_blocks = &state->max_blocks_out;
1.88 markus 974: } else {
1.201 markus 975: cc = &state->receive_context;
1.115 avsm 976: crypt_type = CIPHER_DECRYPT;
1.201 markus 977: state->p_read.packets = state->p_read.blocks = 0;
978: max_blocks = &state->max_blocks_in;
1.88 markus 979: }
1.201 markus 980: if (state->newkeys[mode] != NULL) {
1.224 dtucker 981: debug("set_newkeys: rekeying, input %llu bytes %llu blocks, "
982: "output %llu bytes %llu blocks",
1.227 djm 983: (unsigned long long)state->p_read.bytes,
984: (unsigned long long)state->p_read.blocks,
985: (unsigned long long)state->p_send.bytes,
986: (unsigned long long)state->p_send.blocks);
1.201 markus 987: if ((r = cipher_cleanup(cc)) != 0)
988: return r;
989: enc = &state->newkeys[mode]->enc;
990: mac = &state->newkeys[mode]->mac;
991: comp = &state->newkeys[mode]->comp;
1.148 pvalchev 992: mac_clear(mac);
1.192 djm 993: explicit_bzero(enc->iv, enc->iv_len);
994: explicit_bzero(enc->key, enc->key_len);
995: explicit_bzero(mac->key, mac->key_len);
1.186 djm 996: free(enc->name);
997: free(enc->iv);
998: free(enc->key);
999: free(mac->name);
1000: free(mac->key);
1001: free(comp->name);
1.201 markus 1002: free(state->newkeys[mode]);
1.57 markus 1003: }
1.201 markus 1004: /* move newkeys from kex to state */
1005: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
1006: return SSH_ERR_INTERNAL_ERROR;
1007: ssh->kex->newkeys[mode] = NULL;
1008: enc = &state->newkeys[mode]->enc;
1009: mac = &state->newkeys[mode]->mac;
1010: comp = &state->newkeys[mode]->comp;
1011: if (cipher_authlen(enc->cipher) == 0) {
1012: if ((r = mac_init(mac)) != 0)
1013: return r;
1014: }
1015: mac->enabled = 1;
1.57 markus 1016: DBG(debug("cipher_init_context: %d", mode));
1.197 djm 1017: if ((r = cipher_init(cc, enc->cipher, enc->key, enc->key_len,
1018: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 1019: return r;
1020: if (!state->cipher_warning_done &&
1021: (wmsg = cipher_warning_message(cc)) != NULL) {
1022: error("Warning: %s", wmsg);
1023: state->cipher_warning_done = 1;
1024: }
1.91 markus 1025: /* Deleting the keys does not gain extra security */
1.192 djm 1026: /* explicit_bzero(enc->iv, enc->block_size);
1027: explicit_bzero(enc->key, enc->key_len);
1028: explicit_bzero(mac->key, mac->key_len); */
1.118 markus 1029: if ((comp->type == COMP_ZLIB ||
1.161 andreas 1030: (comp->type == COMP_DELAYED &&
1.201 markus 1031: state->after_authentication)) && comp->enabled == 0) {
1032: if ((r = ssh_packet_init_compression(ssh)) < 0)
1033: return r;
1034: if (mode == MODE_OUT) {
1035: if ((r = start_compression_out(ssh, 6)) != 0)
1036: return r;
1037: } else {
1038: if ((r = start_compression_in(ssh)) != 0)
1039: return r;
1040: }
1.57 markus 1041: comp->enabled = 1;
1042: }
1.109 markus 1043: /*
1044: * The 2^(blocksize*2) limit is too expensive for 3DES,
1045: * blowfish, etc, so enforce a 1GB limit for small blocksizes.
1046: */
1047: if (enc->block_size >= 16)
1048: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
1049: else
1050: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 1051: if (state->rekey_limit)
1.161 andreas 1052: *max_blocks = MIN(*max_blocks,
1.201 markus 1053: state->rekey_limit / enc->block_size);
1.227 djm 1054: debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1.201 markus 1055: return 0;
1.57 markus 1056: }
1057:
1.228 djm 1058: #define MAX_PACKETS (1U<<31)
1059: static int
1060: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
1061: {
1062: struct session_state *state = ssh->state;
1063: u_int32_t out_blocks;
1064:
1065: /* XXX client can't cope with rekeying pre-auth */
1066: if (!state->after_authentication)
1067: return 0;
1068:
1069: /* Haven't keyed yet or KEX in progress. */
1070: if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
1071: return 0;
1072:
1073: /* Peer can't rekey */
1074: if (ssh->compat & SSH_BUG_NOREKEY)
1075: return 0;
1076:
1077: /*
1078: * Permit one packet in or out per rekey - this allows us to
1079: * make progress when rekey limits are very small.
1080: */
1081: if (state->p_send.packets == 0 && state->p_read.packets == 0)
1082: return 0;
1083:
1084: /* Time-based rekeying */
1085: if (state->rekey_interval != 0 &&
1086: state->rekey_time + state->rekey_interval <= monotime())
1087: return 1;
1088:
1089: /* Always rekey when MAX_PACKETS sent in either direction */
1090: if (state->p_send.packets > MAX_PACKETS ||
1091: state->p_read.packets > MAX_PACKETS)
1092: return 1;
1093:
1094: /* Rekey after (cipher-specific) maxiumum blocks */
1095: out_blocks = roundup(outbound_packet_len,
1096: state->newkeys[MODE_OUT]->enc.block_size);
1097: return (state->max_blocks_out &&
1098: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
1099: (state->max_blocks_in &&
1100: (state->p_read.blocks > state->max_blocks_in));
1101: }
1102:
1.16 markus 1103: /*
1.118 markus 1104: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 1105: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 1106: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
1107: */
1.201 markus 1108: static int
1109: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 1110: {
1.201 markus 1111: struct session_state *state = ssh->state;
1112: struct sshcomp *comp = NULL;
1113: int r, mode;
1.118 markus 1114:
1115: /*
1116: * Remember that we are past the authentication step, so rekeying
1117: * with COMP_DELAYED will turn on compression immediately.
1118: */
1.201 markus 1119: state->after_authentication = 1;
1.118 markus 1120: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 1121: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 1122: if (state->newkeys[mode] == NULL)
1.145 markus 1123: continue;
1.201 markus 1124: comp = &state->newkeys[mode]->comp;
1.118 markus 1125: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 1126: if ((r = ssh_packet_init_compression(ssh)) != 0)
1127: return r;
1128: if (mode == MODE_OUT) {
1129: if ((r = start_compression_out(ssh, 6)) != 0)
1130: return r;
1131: } else {
1132: if ((r = start_compression_in(ssh)) != 0)
1133: return r;
1134: }
1.118 markus 1135: comp->enabled = 1;
1136: }
1137: }
1.201 markus 1138: return 0;
1.118 markus 1139: }
1140:
1.226 djm 1141: /* Used to mute debug logging for noisy packet types */
1142: static int
1143: ssh_packet_log_type(u_char type)
1144: {
1145: switch (type) {
1146: case SSH2_MSG_CHANNEL_DATA:
1147: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1148: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1149: return 0;
1150: default:
1151: return 1;
1152: }
1153: }
1154:
1.118 markus 1155: /*
1.25 markus 1156: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1157: */
1.201 markus 1158: int
1159: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1160: {
1.201 markus 1161: struct session_state *state = ssh->state;
1.200 markus 1162: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.178 markus 1163: u_char padlen, pad = 0;
1.201 markus 1164: u_int authlen = 0, aadlen = 0;
1165: u_int len;
1166: struct sshenc *enc = NULL;
1167: struct sshmac *mac = NULL;
1168: struct sshcomp *comp = NULL;
1169: int r, block_size;
1170:
1171: if (state->newkeys[MODE_OUT] != NULL) {
1172: enc = &state->newkeys[MODE_OUT]->enc;
1173: mac = &state->newkeys[MODE_OUT]->mac;
1174: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1175: /* disable mac for authenticated encryption */
1176: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1177: mac = NULL;
1.25 markus 1178: }
1.88 markus 1179: block_size = enc ? enc->block_size : 8;
1.180 markus 1180: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1181:
1.201 markus 1182: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1183: if (ssh_packet_log_type(type))
1184: debug3("send packet: type %u", type);
1.25 markus 1185: #ifdef PACKET_DEBUG
1186: fprintf(stderr, "plain: ");
1.201 markus 1187: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1188: #endif
1189:
1190: if (comp && comp->enabled) {
1.201 markus 1191: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1192: /* skip header, compress only payload */
1.201 markus 1193: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1194: goto out;
1195: sshbuf_reset(state->compression_buffer);
1196: if ((r = compress_buffer(ssh, state->outgoing_packet,
1197: state->compression_buffer)) != 0)
1198: goto out;
1199: sshbuf_reset(state->outgoing_packet);
1200: if ((r = sshbuf_put(state->outgoing_packet,
1201: "\0\0\0\0\0", 5)) != 0 ||
1202: (r = sshbuf_putb(state->outgoing_packet,
1203: state->compression_buffer)) != 0)
1204: goto out;
1205: DBG(debug("compression: raw %d compressed %zd", len,
1206: sshbuf_len(state->outgoing_packet)));
1.25 markus 1207: }
1208:
1209: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1210: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1211:
1212: /*
1213: * calc size of padding, alloc space, get random data,
1214: * minimum padding is 4 bytes
1215: */
1.178 markus 1216: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1217: padlen = block_size - (len % block_size);
1218: if (padlen < 4)
1219: padlen += block_size;
1.201 markus 1220: if (state->extra_pad) {
1.71 markus 1221: /* will wrap if extra_pad+padlen > 255 */
1.201 markus 1222: state->extra_pad =
1223: roundup(state->extra_pad, block_size);
1224: pad = state->extra_pad -
1225: ((len + padlen) % state->extra_pad);
1.193 djm 1226: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1227: __func__, pad, len, padlen, state->extra_pad));
1.71 markus 1228: padlen += pad;
1.201 markus 1229: state->extra_pad = 0;
1.71 markus 1230: }
1.201 markus 1231: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1232: goto out;
1233: if (enc && !state->send_context.plaintext) {
1.32 markus 1234: /* random padding */
1.201 markus 1235: arc4random_buf(cp, padlen);
1.32 markus 1236: } else {
1237: /* clear padding */
1.192 djm 1238: explicit_bzero(cp, padlen);
1.25 markus 1239: }
1.178 markus 1240: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1241: len = sshbuf_len(state->outgoing_packet);
1242: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1243: if (cp == NULL) {
1244: r = SSH_ERR_INTERNAL_ERROR;
1245: goto out;
1246: }
1.25 markus 1247: /* packet_length includes payload, padding and padding length field */
1.201 markus 1248: POKE_U32(cp, len - 4);
1.89 markus 1249: cp[4] = padlen;
1.178 markus 1250: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1251: len, padlen, aadlen));
1.25 markus 1252:
1253: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1254: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1255: if ((r = mac_compute(mac, state->p_send.seqnr,
1256: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1257: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1258: goto out;
1259: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1260: }
1261: /* encrypt packet and append to output buffer. */
1.201 markus 1262: if ((r = sshbuf_reserve(state->output,
1263: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1264: goto out;
1265: if ((r = cipher_crypt(&state->send_context, state->p_send.seqnr, cp,
1266: sshbuf_ptr(state->outgoing_packet),
1267: len - aadlen, aadlen, authlen)) != 0)
1268: goto out;
1.25 markus 1269: /* append unencrypted MAC */
1.178 markus 1270: if (mac && mac->enabled) {
1271: if (mac->etm) {
1272: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1273: if ((r = mac_compute(mac, state->p_send.seqnr,
1274: cp, len, macbuf, sizeof(macbuf))) != 0)
1275: goto out;
1.178 markus 1276: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1277: state->p_send.seqnr));
1.178 markus 1278: }
1.201 markus 1279: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1280: goto out;
1.178 markus 1281: }
1.25 markus 1282: #ifdef PACKET_DEBUG
1283: fprintf(stderr, "encrypted: ");
1.201 markus 1284: sshbuf_dump(state->output, stderr);
1.25 markus 1285: #endif
1.29 markus 1286: /* increment sequence number for outgoing packets */
1.201 markus 1287: if (++state->p_send.seqnr == 0)
1.106 itojun 1288: logit("outgoing seqnr wraps around");
1.201 markus 1289: if (++state->p_send.packets == 0)
1290: if (!(ssh->compat & SSH_BUG_NOREKEY))
1291: return SSH_ERR_NEED_REKEY;
1292: state->p_send.blocks += len / block_size;
1293: state->p_send.bytes += len;
1294: sshbuf_reset(state->outgoing_packet);
1.25 markus 1295:
1.57 markus 1296: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1297: r = ssh_set_newkeys(ssh, MODE_OUT);
1298: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1299: r = ssh_packet_enable_delayed_compress(ssh);
1300: else
1301: r = 0;
1302: out:
1303: return r;
1.25 markus 1304: }
1305:
1.228 djm 1306: /* returns non-zero if the specified packet type is usec by KEX */
1307: static int
1308: ssh_packet_type_is_kex(u_char type)
1309: {
1310: return
1311: type >= SSH2_MSG_TRANSPORT_MIN &&
1312: type <= SSH2_MSG_TRANSPORT_MAX &&
1313: type != SSH2_MSG_SERVICE_REQUEST &&
1314: type != SSH2_MSG_SERVICE_ACCEPT &&
1315: type != SSH2_MSG_EXT_INFO;
1316: }
1317:
1.201 markus 1318: int
1319: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1320: {
1.201 markus 1321: struct session_state *state = ssh->state;
1.105 markus 1322: struct packet *p;
1.201 markus 1323: u_char type;
1.228 djm 1324: int r, need_rekey;
1.105 markus 1325:
1.228 djm 1326: if (sshbuf_len(state->outgoing_packet) < 6)
1327: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1328: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1329: need_rekey = !ssh_packet_type_is_kex(type) &&
1330: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1331:
1.228 djm 1332: /*
1333: * During rekeying we can only send key exchange messages.
1334: * Queue everything else.
1335: */
1336: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1337: if (need_rekey)
1338: debug3("%s: rekex triggered", __func__);
1339: debug("enqueue packet: %u", type);
1340: p = calloc(1, sizeof(*p));
1341: if (p == NULL)
1342: return SSH_ERR_ALLOC_FAIL;
1343: p->type = type;
1344: p->payload = state->outgoing_packet;
1345: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1346: state->outgoing_packet = sshbuf_new();
1347: if (state->outgoing_packet == NULL)
1348: return SSH_ERR_ALLOC_FAIL;
1349: if (need_rekey) {
1350: /*
1351: * This packet triggered a rekey, so send the
1352: * KEXINIT now.
1353: * NB. reenters this function via kex_start_rekex().
1354: */
1355: return kex_start_rekex(ssh);
1.105 markus 1356: }
1.228 djm 1357: return 0;
1.105 markus 1358: }
1359:
1360: /* rekeying starts with sending KEXINIT */
1361: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1362: state->rekeying = 1;
1.105 markus 1363:
1.201 markus 1364: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1365: return r;
1.105 markus 1366:
1367: /* after a NEWKEYS message we can send the complete queue */
1368: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1369: state->rekeying = 0;
1370: state->rekey_time = monotime();
1371: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1372: type = p->type;
1.228 djm 1373: /*
1374: * If this packet triggers a rekex, then skip the
1375: * remaining packets in the queue for now.
1376: * NB. re-enters this function via kex_start_rekex.
1377: */
1378: if (ssh_packet_need_rekeying(ssh,
1379: sshbuf_len(p->payload))) {
1380: debug3("%s: queued packet triggered rekex",
1381: __func__);
1382: return kex_start_rekex(ssh);
1383: }
1.105 markus 1384: debug("dequeue packet: %u", type);
1.201 markus 1385: sshbuf_free(state->outgoing_packet);
1386: state->outgoing_packet = p->payload;
1387: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1388: memset(p, 0, sizeof(*p));
1.186 djm 1389: free(p);
1.201 markus 1390: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1391: return r;
1.105 markus 1392: }
1393: }
1.201 markus 1394: return 0;
1.25 markus 1395: }
1396:
1397: /*
1.16 markus 1398: * Waits until a packet has been received, and returns its type. Note that
1399: * no other data is processed until this returns, so this function should not
1400: * be used during the interactive session.
1401: */
1.1 deraadt 1402:
1.2 provos 1403: int
1.201 markus 1404: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1405: {
1.201 markus 1406: struct session_state *state = ssh->state;
1.222 markus 1407: int len, r, ms_remain;
1.56 millert 1408: fd_set *setp;
1.14 markus 1409: char buf[8192];
1.155 deraadt 1410: struct timeval timeout, start, *timeoutp = NULL;
1411:
1.25 markus 1412: DBG(debug("packet_read()"));
1.14 markus 1413:
1.214 deraadt 1414: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1415: NFDBITS), sizeof(fd_mask));
1.201 markus 1416: if (setp == NULL)
1417: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1418:
1.205 djm 1419: /*
1420: * Since we are blocking, ensure that all written packets have
1421: * been sent.
1422: */
1.210 markus 1423: if ((r = ssh_packet_write_wait(ssh)) != 0)
1424: goto out;
1.14 markus 1425:
1426: /* Stay in the loop until we have received a complete packet. */
1427: for (;;) {
1428: /* Try to read a packet from the buffer. */
1.201 markus 1429: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1430: if (r != 0)
1431: break;
1.62 markus 1432: if (!compat20 && (
1.201 markus 1433: *typep == SSH_SMSG_SUCCESS
1434: || *typep == SSH_SMSG_FAILURE
1435: || *typep == SSH_CMSG_EOF
1436: || *typep == SSH_CMSG_EXIT_CONFIRMATION))
1437: if ((r = sshpkt_get_end(ssh)) != 0)
1438: break;
1.14 markus 1439: /* If we got a packet, return it. */
1.201 markus 1440: if (*typep != SSH_MSG_NONE)
1441: break;
1.16 markus 1442: /*
1443: * Otherwise, wait for some data to arrive, add it to the
1444: * buffer, and try again.
1445: */
1.201 markus 1446: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1447: NFDBITS) * sizeof(fd_mask));
1.201 markus 1448: FD_SET(state->connection_in, setp);
1.16 markus 1449:
1.201 markus 1450: if (state->packet_timeout_ms > 0) {
1451: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1452: timeoutp = &timeout;
1453: }
1.14 markus 1454: /* Wait for some data to arrive. */
1.154 dtucker 1455: for (;;) {
1.201 markus 1456: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1457: ms_to_timeval(&timeout, ms_remain);
1458: gettimeofday(&start, NULL);
1459: }
1.201 markus 1460: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1461: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1462: break;
1.161 andreas 1463: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1464: break;
1.201 markus 1465: if (state->packet_timeout_ms == -1)
1.154 dtucker 1466: continue;
1467: ms_subtract_diff(&start, &ms_remain);
1468: if (ms_remain <= 0) {
1.201 markus 1469: r = 0;
1.154 dtucker 1470: break;
1471: }
1472: }
1.204 djm 1473: if (r == 0)
1474: return SSH_ERR_CONN_TIMEOUT;
1.14 markus 1475: /* Read data from the socket. */
1.222 markus 1476: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1477: if (len == 0) {
1478: r = SSH_ERR_CONN_CLOSED;
1479: goto out;
1480: }
1481: if (len < 0) {
1482: r = SSH_ERR_SYSTEM_ERROR;
1483: goto out;
1484: }
1.204 djm 1485:
1.14 markus 1486: /* Append it to the buffer. */
1.204 djm 1487: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1488: goto out;
1.14 markus 1489: }
1.210 markus 1490: out:
1.201 markus 1491: free(setp);
1492: return r;
1.1 deraadt 1493: }
1494:
1.77 djm 1495: int
1.201 markus 1496: ssh_packet_read(struct ssh *ssh)
1.77 djm 1497: {
1.201 markus 1498: u_char type;
1499: int r;
1500:
1501: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1502: fatal("%s: %s", __func__, ssh_err(r));
1503: return type;
1.77 djm 1504: }
1505:
1.16 markus 1506: /*
1507: * Waits until a packet has been received, verifies that its type matches
1508: * that given, and gives a fatal error and exits if there is a mismatch.
1509: */
1.1 deraadt 1510:
1.205 djm 1511: int
1512: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1513: {
1.205 djm 1514: int r;
1515: u_char type;
1.1 deraadt 1516:
1.205 djm 1517: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1518: return r;
1519: if (type != expected_type) {
1520: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1521: "Protocol error: expected packet type %d, got %d",
1.205 djm 1522: expected_type, type)) != 0)
1523: return r;
1524: return SSH_ERR_PROTOCOL_ERROR;
1525: }
1526: return 0;
1.1 deraadt 1527: }
1528:
1529: /* Checks if a full packet is available in the data received so far via
1.14 markus 1530: * packet_process_incoming. If so, reads the packet; otherwise returns
1531: * SSH_MSG_NONE. This does not wait for data from the connection.
1532: *
1.150 dtucker 1533: * SSH_MSG_DISCONNECT is handled specially here. Also,
1534: * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1535: * to higher levels.
1.14 markus 1536: */
1.1 deraadt 1537:
1.201 markus 1538: int
1539: ssh_packet_read_poll1(struct ssh *ssh, u_char *typep)
1.1 deraadt 1540: {
1.201 markus 1541: struct session_state *state = ssh->state;
1.40 markus 1542: u_int len, padded_len;
1.205 djm 1543: const char *emsg;
1.201 markus 1544: const u_char *cp;
1545: u_char *p;
1.40 markus 1546: u_int checksum, stored_checksum;
1.201 markus 1547: int r;
1548:
1549: *typep = SSH_MSG_NONE;
1.14 markus 1550:
1551: /* Check if input size is less than minimum packet size. */
1.201 markus 1552: if (sshbuf_len(state->input) < 4 + 8)
1553: return 0;
1.14 markus 1554: /* Get length of incoming packet. */
1.201 markus 1555: len = PEEK_U32(sshbuf_ptr(state->input));
1.205 djm 1556: if (len < 1 + 2 + 2 || len > 256 * 1024) {
1557: if ((r = sshpkt_disconnect(ssh, "Bad packet length %u",
1558: len)) != 0)
1559: return r;
1560: return SSH_ERR_CONN_CORRUPT;
1561: }
1.14 markus 1562: padded_len = (len + 8) & ~7;
1563:
1564: /* Check if the packet has been entirely received. */
1.201 markus 1565: if (sshbuf_len(state->input) < 4 + padded_len)
1566: return 0;
1.14 markus 1567:
1568: /* The entire packet is in buffer. */
1569:
1570: /* Consume packet length. */
1.201 markus 1571: if ((r = sshbuf_consume(state->input, 4)) != 0)
1572: goto out;
1.14 markus 1573:
1.62 markus 1574: /*
1575: * Cryptographic attack detector for ssh
1576: * (C)1998 CORE-SDI, Buenos Aires Argentina
1577: * Ariel Futoransky(futo@core-sdi.com)
1578: */
1.201 markus 1579: if (!state->receive_context.plaintext) {
1.205 djm 1580: emsg = NULL;
1.201 markus 1581: switch (detect_attack(&state->deattack,
1582: sshbuf_ptr(state->input), padded_len)) {
1583: case DEATTACK_OK:
1584: break;
1.144 djm 1585: case DEATTACK_DETECTED:
1.205 djm 1586: emsg = "crc32 compensation attack detected";
1587: break;
1.144 djm 1588: case DEATTACK_DOS_DETECTED:
1.205 djm 1589: emsg = "deattack denial of service detected";
1590: break;
1.201 markus 1591: default:
1.205 djm 1592: emsg = "deattack error";
1593: break;
1594: }
1595: if (emsg != NULL) {
1596: error("%s", emsg);
1597: if ((r = sshpkt_disconnect(ssh, "%s", emsg)) != 0 ||
1598: (r = ssh_packet_write_wait(ssh)) != 0)
1599: return r;
1600: return SSH_ERR_CONN_CORRUPT;
1.144 djm 1601: }
1602: }
1.62 markus 1603:
1604: /* Decrypt data to incoming_packet. */
1.201 markus 1605: sshbuf_reset(state->incoming_packet);
1606: if ((r = sshbuf_reserve(state->incoming_packet, padded_len, &p)) != 0)
1607: goto out;
1608: if ((r = cipher_crypt(&state->receive_context, 0, p,
1609: sshbuf_ptr(state->input), padded_len, 0, 0)) != 0)
1610: goto out;
1.62 markus 1611:
1.201 markus 1612: if ((r = sshbuf_consume(state->input, padded_len)) != 0)
1613: goto out;
1.1 deraadt 1614:
1615: #ifdef PACKET_DEBUG
1.14 markus 1616: fprintf(stderr, "read_poll plain: ");
1.201 markus 1617: sshbuf_dump(state->incoming_packet, stderr);
1.1 deraadt 1618: #endif
1619:
1.14 markus 1620: /* Compute packet checksum. */
1.201 markus 1621: checksum = ssh_crc32(sshbuf_ptr(state->incoming_packet),
1622: sshbuf_len(state->incoming_packet) - 4);
1.14 markus 1623:
1624: /* Skip padding. */
1.201 markus 1625: if ((r = sshbuf_consume(state->incoming_packet, 8 - len % 8)) != 0)
1626: goto out;
1.14 markus 1627:
1628: /* Test check bytes. */
1.205 djm 1629: if (len != sshbuf_len(state->incoming_packet)) {
1630: error("%s: len %d != sshbuf_len %zd", __func__,
1.201 markus 1631: len, sshbuf_len(state->incoming_packet));
1.205 djm 1632: if ((r = sshpkt_disconnect(ssh, "invalid packet length")) != 0 ||
1633: (r = ssh_packet_write_wait(ssh)) != 0)
1634: return r;
1635: return SSH_ERR_CONN_CORRUPT;
1636: }
1.14 markus 1637:
1.201 markus 1638: cp = sshbuf_ptr(state->incoming_packet) + len - 4;
1639: stored_checksum = PEEK_U32(cp);
1.205 djm 1640: if (checksum != stored_checksum) {
1641: error("Corrupted check bytes on input");
1642: if ((r = sshpkt_disconnect(ssh, "connection corrupted")) != 0 ||
1643: (r = ssh_packet_write_wait(ssh)) != 0)
1644: return r;
1645: return SSH_ERR_CONN_CORRUPT;
1646: }
1.201 markus 1647: if ((r = sshbuf_consume_end(state->incoming_packet, 4)) < 0)
1648: goto out;
1649:
1650: if (state->packet_compression) {
1651: sshbuf_reset(state->compression_buffer);
1652: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1653: state->compression_buffer)) != 0)
1654: goto out;
1655: sshbuf_reset(state->incoming_packet);
1656: if ((r = sshbuf_putb(state->incoming_packet,
1657: state->compression_buffer)) != 0)
1658: goto out;
1659: }
1660: state->p_read.packets++;
1661: state->p_read.bytes += padded_len + 4;
1662: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1663: goto out;
1.205 djm 1664: if (*typep < SSH_MSG_MIN || *typep > SSH_MSG_MAX) {
1665: error("Invalid ssh1 packet type: %d", *typep);
1666: if ((r = sshpkt_disconnect(ssh, "invalid packet type")) != 0 ||
1667: (r = ssh_packet_write_wait(ssh)) != 0)
1668: return r;
1669: return SSH_ERR_PROTOCOL_ERROR;
1670: }
1.201 markus 1671: r = 0;
1672: out:
1673: return r;
1.1 deraadt 1674: }
1.14 markus 1675:
1.201 markus 1676: int
1677: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1678: {
1.201 markus 1679: struct session_state *state = ssh->state;
1.40 markus 1680: u_int padlen, need;
1.201 markus 1681: u_char *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1682: u_int maclen, aadlen = 0, authlen = 0, block_size;
1683: struct sshenc *enc = NULL;
1684: struct sshmac *mac = NULL;
1685: struct sshcomp *comp = NULL;
1.200 markus 1686: int r;
1.201 markus 1687:
1688: *typep = SSH_MSG_NONE;
1689:
1690: if (state->packet_discard)
1691: return 0;
1692:
1693: if (state->newkeys[MODE_IN] != NULL) {
1694: enc = &state->newkeys[MODE_IN]->enc;
1695: mac = &state->newkeys[MODE_IN]->mac;
1696: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1697: /* disable mac for authenticated encryption */
1698: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1699: mac = NULL;
1.25 markus 1700: }
1701: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1702: block_size = enc ? enc->block_size : 8;
1.180 markus 1703: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1704:
1.201 markus 1705: if (aadlen && state->packlen == 0) {
1706: if (cipher_get_length(&state->receive_context,
1707: &state->packlen, state->p_read.seqnr,
1708: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1709: return 0;
1710: if (state->packlen < 1 + 4 ||
1711: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1712: #ifdef PACKET_DEBUG
1.201 markus 1713: sshbuf_dump(state->input, stderr);
1.178 markus 1714: #endif
1.201 markus 1715: logit("Bad packet length %u.", state->packlen);
1716: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1717: return r;
1.217 djm 1718: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1719: }
1.201 markus 1720: sshbuf_reset(state->incoming_packet);
1721: } else if (state->packlen == 0) {
1.25 markus 1722: /*
1723: * check if input size is less than the cipher block size,
1724: * decrypt first block and extract length of incoming packet
1725: */
1.201 markus 1726: if (sshbuf_len(state->input) < block_size)
1727: return 0;
1728: sshbuf_reset(state->incoming_packet);
1729: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1730: &cp)) != 0)
1731: goto out;
1732: if ((r = cipher_crypt(&state->receive_context,
1733: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1734: block_size, 0, 0)) != 0)
1735: goto out;
1736: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1737: if (state->packlen < 1 + 4 ||
1738: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1739: #ifdef PACKET_DEBUG
1.201 markus 1740: fprintf(stderr, "input: \n");
1741: sshbuf_dump(state->input, stderr);
1742: fprintf(stderr, "incoming_packet: \n");
1743: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1744: #endif
1.201 markus 1745: logit("Bad packet length %u.", state->packlen);
1746: return ssh_packet_start_discard(ssh, enc, mac,
1747: state->packlen, PACKET_MAX_SIZE);
1.25 markus 1748: }
1.201 markus 1749: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1750: goto out;
1.25 markus 1751: }
1.201 markus 1752: DBG(debug("input: packet len %u", state->packlen+4));
1753:
1.178 markus 1754: if (aadlen) {
1755: /* only the payload is encrypted */
1.201 markus 1756: need = state->packlen;
1.178 markus 1757: } else {
1758: /*
1759: * the payload size and the payload are encrypted, but we
1760: * have a partial packet of block_size bytes
1761: */
1.201 markus 1762: need = 4 + state->packlen - block_size;
1.178 markus 1763: }
1.180 markus 1764: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1765: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1766: if (need % block_size != 0) {
1767: logit("padding error: need %d block %d mod %d",
1.25 markus 1768: need, block_size, need % block_size);
1.201 markus 1769: return ssh_packet_start_discard(ssh, enc, mac,
1770: state->packlen, PACKET_MAX_SIZE - block_size);
1.158 markus 1771: }
1.25 markus 1772: /*
1773: * check if the entire packet has been received and
1.178 markus 1774: * decrypt into incoming_packet:
1775: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1776: * 'need' bytes are encrypted, followed by either
1777: * 'authlen' bytes of authentication tag or
1.178 markus 1778: * 'maclen' bytes of message authentication code.
1.25 markus 1779: */
1.201 markus 1780: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1781: return 0;
1.25 markus 1782: #ifdef PACKET_DEBUG
1783: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1784: sshbuf_dump(state->input, stderr);
1.25 markus 1785: #endif
1.178 markus 1786: /* EtM: compute mac over encrypted input */
1.201 markus 1787: if (mac && mac->enabled && mac->etm) {
1788: if ((r = mac_compute(mac, state->p_read.seqnr,
1789: sshbuf_ptr(state->input), aadlen + need,
1.200 markus 1790: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1791: goto out;
1792: }
1793: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1794: &cp)) != 0)
1795: goto out;
1796: if ((r = cipher_crypt(&state->receive_context, state->p_read.seqnr, cp,
1797: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1798: goto out;
1799: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1800: goto out;
1.25 markus 1801: /*
1802: * compute MAC over seqnr and packet,
1803: * increment sequence number for incoming packet
1804: */
1.29 markus 1805: if (mac && mac->enabled) {
1.178 markus 1806: if (!mac->etm)
1.201 markus 1807: if ((r = mac_compute(mac, state->p_read.seqnr,
1808: sshbuf_ptr(state->incoming_packet),
1809: sshbuf_len(state->incoming_packet),
1.200 markus 1810: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1811: goto out;
1812: if (timingsafe_bcmp(macbuf, sshbuf_ptr(state->input),
1.161 andreas 1813: mac->mac_len) != 0) {
1.159 markus 1814: logit("Corrupted MAC on input.");
1815: if (need > PACKET_MAX_SIZE)
1.201 markus 1816: return SSH_ERR_INTERNAL_ERROR;
1817: return ssh_packet_start_discard(ssh, enc, mac,
1818: state->packlen, PACKET_MAX_SIZE - need);
1819: }
1820:
1821: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1822: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1823: goto out;
1.25 markus 1824: }
1.77 djm 1825: if (seqnr_p != NULL)
1.201 markus 1826: *seqnr_p = state->p_read.seqnr;
1827: if (++state->p_read.seqnr == 0)
1.106 itojun 1828: logit("incoming seqnr wraps around");
1.201 markus 1829: if (++state->p_read.packets == 0)
1830: if (!(ssh->compat & SSH_BUG_NOREKEY))
1831: return SSH_ERR_NEED_REKEY;
1832: state->p_read.blocks += (state->packlen + 4) / block_size;
1833: state->p_read.bytes += state->packlen + 4;
1.25 markus 1834:
1835: /* get padlen */
1.201 markus 1836: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1837: DBG(debug("input: padlen %d", padlen));
1.205 djm 1838: if (padlen < 4) {
1839: if ((r = sshpkt_disconnect(ssh,
1840: "Corrupted padlen %d on input.", padlen)) != 0 ||
1841: (r = ssh_packet_write_wait(ssh)) != 0)
1842: return r;
1843: return SSH_ERR_CONN_CORRUPT;
1844: }
1.25 markus 1845:
1846: /* skip packet size + padlen, discard padding */
1.201 markus 1847: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1848: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1849: goto out;
1.25 markus 1850:
1.201 markus 1851: DBG(debug("input: len before de-compress %zd",
1852: sshbuf_len(state->incoming_packet)));
1.25 markus 1853: if (comp && comp->enabled) {
1.201 markus 1854: sshbuf_reset(state->compression_buffer);
1855: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1856: state->compression_buffer)) != 0)
1857: goto out;
1858: sshbuf_reset(state->incoming_packet);
1859: if ((r = sshbuf_putb(state->incoming_packet,
1860: state->compression_buffer)) != 0)
1861: goto out;
1862: DBG(debug("input: len after de-compress %zd",
1863: sshbuf_len(state->incoming_packet)));
1.25 markus 1864: }
1865: /*
1866: * get packet type, implies consume.
1867: * return length of payload (without type field)
1868: */
1.201 markus 1869: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1870: goto out;
1.226 djm 1871: if (ssh_packet_log_type(*typep))
1872: debug3("receive packet: type %u", *typep);
1.205 djm 1873: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1874: if ((r = sshpkt_disconnect(ssh,
1875: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1876: (r = ssh_packet_write_wait(ssh)) != 0)
1877: return r;
1878: return SSH_ERR_PROTOCOL_ERROR;
1879: }
1.201 markus 1880: if (*typep == SSH2_MSG_NEWKEYS)
1881: r = ssh_set_newkeys(ssh, MODE_IN);
1882: else if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1883: r = ssh_packet_enable_delayed_compress(ssh);
1884: else
1885: r = 0;
1.25 markus 1886: #ifdef PACKET_DEBUG
1.201 markus 1887: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1888: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1889: #endif
1.62 markus 1890: /* reset for next packet */
1.201 markus 1891: state->packlen = 0;
1.228 djm 1892:
1893: /* do we need to rekey? */
1894: if (ssh_packet_need_rekeying(ssh, 0)) {
1895: debug3("%s: rekex triggered", __func__);
1896: if ((r = kex_start_rekex(ssh)) != 0)
1897: return r;
1898: }
1.201 markus 1899: out:
1900: return r;
1.25 markus 1901: }
1902:
1903: int
1.201 markus 1904: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1905: {
1.201 markus 1906: struct session_state *state = ssh->state;
1.96 deraadt 1907: u_int reason, seqnr;
1.201 markus 1908: int r;
1909: u_char *msg;
1.62 markus 1910:
1.25 markus 1911: for (;;) {
1.201 markus 1912: msg = NULL;
1.62 markus 1913: if (compat20) {
1.201 markus 1914: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1915: if (r != 0)
1916: return r;
1917: if (*typep) {
1918: state->keep_alive_timeouts = 0;
1919: DBG(debug("received packet type %d", *typep));
1.153 djm 1920: }
1.201 markus 1921: switch (*typep) {
1.150 dtucker 1922: case SSH2_MSG_IGNORE:
1.151 dtucker 1923: debug3("Received SSH2_MSG_IGNORE");
1.150 dtucker 1924: break;
1.25 markus 1925: case SSH2_MSG_DEBUG:
1.201 markus 1926: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1927: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1928: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1.219 mmcc 1929: free(msg);
1.201 markus 1930: return r;
1931: }
1.25 markus 1932: debug("Remote: %.900s", msg);
1.186 djm 1933: free(msg);
1.25 markus 1934: break;
1935: case SSH2_MSG_DISCONNECT:
1.201 markus 1936: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1937: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1938: return r;
1.182 djm 1939: /* Ignore normal client exit notifications */
1.201 markus 1940: do_log2(ssh->state->server_side &&
1.182 djm 1941: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1942: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1.220 djm 1943: "Received disconnect from %s port %d:"
1944: "%u: %.400s", ssh_remote_ipaddr(ssh),
1945: ssh_remote_port(ssh), reason, msg);
1.186 djm 1946: free(msg);
1.201 markus 1947: return SSH_ERR_DISCONNECTED;
1.84 markus 1948: case SSH2_MSG_UNIMPLEMENTED:
1.201 markus 1949: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1950: return r;
1.96 deraadt 1951: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1952: seqnr);
1.150 dtucker 1953: break;
1.25 markus 1954: default:
1.201 markus 1955: return 0;
1.48 stevesk 1956: }
1.25 markus 1957: } else {
1.201 markus 1958: r = ssh_packet_read_poll1(ssh, typep);
1959: switch (*typep) {
1.188 djm 1960: case SSH_MSG_NONE:
1961: return SSH_MSG_NONE;
1.25 markus 1962: case SSH_MSG_IGNORE:
1963: break;
1964: case SSH_MSG_DEBUG:
1.201 markus 1965: if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1966: return r;
1.25 markus 1967: debug("Remote: %.900s", msg);
1.186 djm 1968: free(msg);
1.25 markus 1969: break;
1970: case SSH_MSG_DISCONNECT:
1.201 markus 1971: if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1972: return r;
1.220 djm 1973: error("Received disconnect from %s port %d: "
1974: "%.400s", ssh_remote_ipaddr(ssh),
1975: ssh_remote_port(ssh), msg);
1.201 markus 1976: free(msg);
1977: return SSH_ERR_DISCONNECTED;
1.25 markus 1978: default:
1.201 markus 1979: DBG(debug("received packet type %d", *typep));
1980: return 0;
1.48 stevesk 1981: }
1.25 markus 1982: }
1983: }
1984: }
1985:
1.16 markus 1986: /*
1987: * Buffers the given amount of input characters. This is intended to be used
1988: * together with packet_read_poll.
1989: */
1.1 deraadt 1990:
1.204 djm 1991: int
1.201 markus 1992: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1993: {
1.201 markus 1994: struct session_state *state = ssh->state;
1995: int r;
1996:
1997: if (state->packet_discard) {
1998: state->keep_alive_timeouts = 0; /* ?? */
1999: if (len >= state->packet_discard) {
2000: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 2001: return r;
1.201 markus 2002: }
2003: state->packet_discard -= len;
1.204 djm 2004: return 0;
1.159 markus 2005: }
1.201 markus 2006: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 2007: return r;
2008:
2009: return 0;
1.28 markus 2010: }
2011:
2012: int
1.201 markus 2013: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 2014: {
1.201 markus 2015: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 2016: }
2017:
1.16 markus 2018: /*
2019: * Sends a diagnostic message from the server to the client. This message
2020: * can be sent at any time (but not while constructing another message). The
2021: * message is printed immediately, but only if the client is being executed
2022: * in verbose mode. These messages are primarily intended to ease debugging
2023: * authentication problems. The length of the formatted message must not
1.205 djm 2024: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 2025: */
1.2 provos 2026: void
1.201 markus 2027: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 2028: {
1.14 markus 2029: char buf[1024];
2030: va_list args;
1.201 markus 2031: int r;
1.39 markus 2032:
1.201 markus 2033: if (compat20 && (ssh->compat & SSH_BUG_DEBUG))
1.39 markus 2034: return;
1.14 markus 2035:
2036: va_start(args, fmt);
2037: vsnprintf(buf, sizeof(buf), fmt, args);
2038: va_end(args);
2039:
1.30 markus 2040: if (compat20) {
1.201 markus 2041: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
2042: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
2043: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2044: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2045: (r = sshpkt_send(ssh)) != 0)
2046: fatal("%s: %s", __func__, ssh_err(r));
1.30 markus 2047: } else {
1.201 markus 2048: if ((r = sshpkt_start(ssh, SSH_MSG_DEBUG)) != 0 ||
2049: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2050: (r = sshpkt_send(ssh)) != 0)
2051: fatal("%s: %s", __func__, ssh_err(r));
1.30 markus 2052: }
1.205 djm 2053: if ((r = ssh_packet_write_wait(ssh)) != 0)
2054: fatal("%s: %s", __func__, ssh_err(r));
2055: }
2056:
2057: /*
2058: * Pretty-print connection-terminating errors and exit.
2059: */
2060: void
2061: sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
2062: {
2063: switch (r) {
2064: case SSH_ERR_CONN_CLOSED:
1.220 djm 2065: logit("Connection closed by %.200s port %d",
2066: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.205 djm 2067: cleanup_exit(255);
2068: case SSH_ERR_CONN_TIMEOUT:
1.220 djm 2069: logit("Connection %s %.200s port %d timed out",
2070: ssh->state->server_side ? "from" : "to",
2071: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.205 djm 2072: cleanup_exit(255);
1.212 djm 2073: case SSH_ERR_DISCONNECTED:
1.220 djm 2074: logit("Disconnected from %.200s port %d",
2075: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.212 djm 2076: cleanup_exit(255);
2077: case SSH_ERR_SYSTEM_ERROR:
2078: if (errno == ECONNRESET) {
1.220 djm 2079: logit("Connection reset by %.200s port %d",
2080: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.212 djm 2081: cleanup_exit(255);
1.213 djm 2082: }
2083: /* FALLTHROUGH */
2084: case SSH_ERR_NO_CIPHER_ALG_MATCH:
2085: case SSH_ERR_NO_MAC_ALG_MATCH:
2086: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
2087: case SSH_ERR_NO_KEX_ALG_MATCH:
2088: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
2089: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.220 djm 2090: fatal("Unable to negotiate with %.200s port %d: %s. "
1.213 djm 2091: "Their offer: %s", ssh_remote_ipaddr(ssh),
1.220 djm 2092: ssh_remote_port(ssh), ssh_err(r),
2093: ssh->kex->failed_choice);
1.212 djm 2094: }
2095: /* FALLTHROUGH */
1.205 djm 2096: default:
1.220 djm 2097: fatal("%s%sConnection %s %.200s port %d: %s",
1.205 djm 2098: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 2099: ssh->state->server_side ? "from" : "to",
2100: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), ssh_err(r));
1.205 djm 2101: }
1.1 deraadt 2102: }
2103:
1.16 markus 2104: /*
2105: * Logs the error plus constructs and sends a disconnect packet, closes the
2106: * connection, and exits. This function never returns. The error message
2107: * should not contain a newline. The length of the formatted message must
2108: * not exceed 1024 bytes.
2109: */
1.2 provos 2110: void
1.201 markus 2111: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 2112: {
1.14 markus 2113: char buf[1024];
2114: va_list args;
2115: static int disconnecting = 0;
1.201 markus 2116: int r;
1.97 deraadt 2117:
1.14 markus 2118: if (disconnecting) /* Guard against recursive invocations. */
2119: fatal("packet_disconnect called recursively.");
2120: disconnecting = 1;
2121:
1.16 markus 2122: /*
2123: * Format the message. Note that the caller must make sure the
2124: * message is of limited size.
2125: */
1.14 markus 2126: va_start(args, fmt);
2127: vsnprintf(buf, sizeof(buf), fmt, args);
2128: va_end(args);
2129:
1.99 markus 2130: /* Display the error locally */
1.106 itojun 2131: logit("Disconnecting: %.100s", buf);
1.99 markus 2132:
1.205 djm 2133: /*
2134: * Send the disconnect message to the other side, and wait
2135: * for it to get sent.
2136: */
2137: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
2138: sshpkt_fatal(ssh, __func__, r);
2139:
2140: if ((r = ssh_packet_write_wait(ssh)) != 0)
2141: sshpkt_fatal(ssh, __func__, r);
1.14 markus 2142:
2143: /* Close the connection. */
1.201 markus 2144: ssh_packet_close(ssh);
1.112 markus 2145: cleanup_exit(255);
1.1 deraadt 2146: }
2147:
1.205 djm 2148: /*
2149: * Checks if there is any buffered output, and tries to write some of
2150: * the output.
2151: */
2152: int
1.201 markus 2153: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 2154: {
1.201 markus 2155: struct session_state *state = ssh->state;
2156: int len = sshbuf_len(state->output);
1.222 markus 2157: int r;
1.97 deraadt 2158:
1.14 markus 2159: if (len > 0) {
1.222 markus 2160: len = write(state->connection_out,
2161: sshbuf_ptr(state->output), len);
1.156 djm 2162: if (len == -1) {
2163: if (errno == EINTR || errno == EAGAIN)
1.205 djm 2164: return 0;
2165: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 2166: }
1.222 markus 2167: if (len == 0)
1.205 djm 2168: return SSH_ERR_CONN_CLOSED;
1.201 markus 2169: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 2170: return r;
1.14 markus 2171: }
1.205 djm 2172: return 0;
1.1 deraadt 2173: }
2174:
1.16 markus 2175: /*
2176: * Calls packet_write_poll repeatedly until all pending output data has been
2177: * written.
2178: */
1.205 djm 2179: int
1.201 markus 2180: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 2181: {
1.56 millert 2182: fd_set *setp;
1.205 djm 2183: int ret, r, ms_remain = 0;
1.154 dtucker 2184: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 2185: struct session_state *state = ssh->state;
1.56 millert 2186:
1.214 deraadt 2187: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 2188: NFDBITS), sizeof(fd_mask));
1.201 markus 2189: if (setp == NULL)
1.205 djm 2190: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 2191: if ((r = ssh_packet_write_poll(ssh)) != 0) {
2192: free(setp);
1.215 djm 2193: return r;
1.216 gsoares 2194: }
1.201 markus 2195: while (ssh_packet_have_data_to_write(ssh)) {
2196: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 2197: NFDBITS) * sizeof(fd_mask));
1.201 markus 2198: FD_SET(state->connection_out, setp);
1.154 dtucker 2199:
1.201 markus 2200: if (state->packet_timeout_ms > 0) {
2201: ms_remain = state->packet_timeout_ms;
1.154 dtucker 2202: timeoutp = &timeout;
2203: }
2204: for (;;) {
1.201 markus 2205: if (state->packet_timeout_ms != -1) {
1.154 dtucker 2206: ms_to_timeval(&timeout, ms_remain);
2207: gettimeofday(&start, NULL);
2208: }
1.201 markus 2209: if ((ret = select(state->connection_out + 1,
1.161 andreas 2210: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 2211: break;
1.161 andreas 2212: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 2213: break;
1.201 markus 2214: if (state->packet_timeout_ms == -1)
1.154 dtucker 2215: continue;
2216: ms_subtract_diff(&start, &ms_remain);
2217: if (ms_remain <= 0) {
2218: ret = 0;
2219: break;
2220: }
2221: }
2222: if (ret == 0) {
1.205 djm 2223: free(setp);
2224: return SSH_ERR_CONN_TIMEOUT;
2225: }
2226: if ((r = ssh_packet_write_poll(ssh)) != 0) {
2227: free(setp);
2228: return r;
1.154 dtucker 2229: }
1.14 markus 2230: }
1.186 djm 2231: free(setp);
1.205 djm 2232: return 0;
1.1 deraadt 2233: }
2234:
2235: /* Returns true if there is buffered data to write to the connection. */
2236:
1.2 provos 2237: int
1.201 markus 2238: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 2239: {
1.201 markus 2240: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 2241: }
2242:
2243: /* Returns true if there is not too much data to write to the connection. */
2244:
1.2 provos 2245: int
1.201 markus 2246: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 2247: {
1.201 markus 2248: if (ssh->state->interactive_mode)
2249: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 2250: else
1.201 markus 2251: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 2252: }
2253:
1.201 markus 2254: void
2255: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 2256: {
1.201 markus 2257: if (!ssh_packet_connection_is_on_socket(ssh))
1.101 markus 2258: return;
1.201 markus 2259: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 2260: case AF_INET:
2261: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 2262: if (setsockopt(ssh->state->connection_in,
1.173 djm 2263: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
2264: error("setsockopt IP_TOS %d: %.100s:",
2265: tos, strerror(errno));
2266: break;
2267: case AF_INET6:
2268: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 2269: if (setsockopt(ssh->state->connection_in,
1.173 djm 2270: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2271: error("setsockopt IPV6_TCLASS %d: %.100s:",
2272: tos, strerror(errno));
2273: break;
2274: }
1.101 markus 2275: }
2276:
1.1 deraadt 2277: /* Informs that the current session is interactive. Sets IP flags for that. */
2278:
1.2 provos 2279: void
1.201 markus 2280: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2281: {
1.201 markus 2282: struct session_state *state = ssh->state;
2283:
2284: if (state->set_interactive_called)
1.43 markus 2285: return;
1.201 markus 2286: state->set_interactive_called = 1;
1.1 deraadt 2287:
1.14 markus 2288: /* Record that we are in interactive mode. */
1.201 markus 2289: state->interactive_mode = interactive;
1.1 deraadt 2290:
1.19 markus 2291: /* Only set socket options if using a socket. */
1.201 markus 2292: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2293: return;
1.201 markus 2294: set_nodelay(state->connection_in);
2295: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2296: qos_bulk);
1.1 deraadt 2297: }
2298:
2299: /* Returns true if the current connection is interactive. */
2300:
1.2 provos 2301: int
1.201 markus 2302: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2303: {
1.201 markus 2304: return ssh->state->interactive_mode;
1.12 markus 2305: }
2306:
1.113 deraadt 2307: int
1.201 markus 2308: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2309: {
1.201 markus 2310: struct session_state *state = ssh->state;
2311:
2312: if (state->set_maxsize_called) {
1.106 itojun 2313: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2314: state->max_packet_size, s);
1.14 markus 2315: return -1;
2316: }
2317: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2318: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2319: return -1;
2320: }
1.201 markus 2321: state->set_maxsize_called = 1;
1.66 markus 2322: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2323: state->max_packet_size = s;
1.14 markus 2324: return s;
1.53 markus 2325: }
2326:
1.161 andreas 2327: int
1.201 markus 2328: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2329: {
1.201 markus 2330: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2331: }
2332:
2333: void
1.201 markus 2334: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2335: {
1.201 markus 2336: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2337: }
2338:
2339: u_int
1.201 markus 2340: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2341: {
1.201 markus 2342: return ssh->state->max_packet_size;
1.71 markus 2343: }
2344:
1.53 markus 2345: /*
2346: * 9.2. Ignored Data Message
1.61 markus 2347: *
1.53 markus 2348: * byte SSH_MSG_IGNORE
2349: * string data
1.61 markus 2350: *
1.53 markus 2351: * All implementations MUST understand (and ignore) this message at any
2352: * time (after receiving the protocol version). No implementation is
2353: * required to send them. This message can be used as an additional
2354: * protection measure against advanced traffic analysis techniques.
2355: */
1.54 markus 2356: void
1.201 markus 2357: ssh_packet_send_ignore(struct ssh *ssh, int nbytes)
1.54 markus 2358: {
1.115 avsm 2359: u_int32_t rnd = 0;
1.201 markus 2360: int r, i;
1.54 markus 2361:
1.201 markus 2362: if ((r = sshpkt_start(ssh, compat20 ?
2363: SSH2_MSG_IGNORE : SSH_MSG_IGNORE)) != 0 ||
2364: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2365: fatal("%s: %s", __func__, ssh_err(r));
1.75 deraadt 2366: for (i = 0; i < nbytes; i++) {
1.53 markus 2367: if (i % 4 == 0)
1.115 avsm 2368: rnd = arc4random();
1.201 markus 2369: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2370: fatal("%s: %s", __func__, ssh_err(r));
1.115 avsm 2371: rnd >>= 8;
1.53 markus 2372: }
1.105 markus 2373: }
2374:
2375: void
1.224 dtucker 2376: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, time_t seconds)
1.105 markus 2377: {
1.224 dtucker 2378: debug3("rekey after %llu bytes, %d seconds", (unsigned long long)bytes,
1.184 dtucker 2379: (int)seconds);
1.201 markus 2380: ssh->state->rekey_limit = bytes;
2381: ssh->state->rekey_interval = seconds;
1.184 dtucker 2382: }
2383:
2384: time_t
1.201 markus 2385: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2386: {
2387: time_t seconds;
2388:
1.201 markus 2389: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2390: monotime();
1.185 dtucker 2391: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2392: }
2393:
2394: void
1.201 markus 2395: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2396: {
1.201 markus 2397: ssh->state->server_side = 1;
1.118 markus 2398: }
2399:
2400: void
1.201 markus 2401: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2402: {
1.201 markus 2403: ssh->state->after_authentication = 1;
1.161 andreas 2404: }
2405:
2406: void *
1.201 markus 2407: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2408: {
1.201 markus 2409: return (void *)ssh->state->input;
1.161 andreas 2410: }
2411:
2412: void *
1.201 markus 2413: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2414: {
1.201 markus 2415: return (void *)ssh->state->output;
1.166 andreas 2416: }
2417:
1.196 markus 2418: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2419: static int
2420: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2421: {
1.201 markus 2422: struct sshcomp *comp;
2423: int r, mode;
1.196 markus 2424:
2425: debug("%s: called", __func__);
2426: /* This was set in net child, but is not visible in user child */
1.201 markus 2427: ssh->state->after_authentication = 1;
2428: ssh->state->rekeying = 0;
1.196 markus 2429: for (mode = 0; mode < MODE_MAX; mode++) {
1.201 markus 2430: if (ssh->state->newkeys[mode] == NULL)
1.196 markus 2431: continue;
1.201 markus 2432: comp = &ssh->state->newkeys[mode]->comp;
2433: if (comp && comp->enabled &&
2434: (r = ssh_packet_init_compression(ssh)) != 0)
2435: return r;
2436: }
2437: return 0;
2438: }
2439:
2440: /* Packet state (de-)serialization for privsep */
2441:
2442: /* turn kex into a blob for packet state serialization */
2443: static int
2444: kex_to_blob(struct sshbuf *m, struct kex *kex)
2445: {
2446: int r;
2447:
2448: if ((r = sshbuf_put_string(m, kex->session_id,
2449: kex->session_id_len)) != 0 ||
2450: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2451: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2452: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2453: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2454: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2455: (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2456: (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2457: (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2458: return r;
2459: return 0;
2460: }
2461:
2462: /* turn key exchange results into a blob for packet state serialization */
2463: static int
2464: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2465: {
2466: struct sshbuf *b;
2467: struct sshcipher_ctx *cc;
2468: struct sshcomp *comp;
2469: struct sshenc *enc;
2470: struct sshmac *mac;
2471: struct newkeys *newkey;
2472: int r;
2473:
2474: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2475: return SSH_ERR_INTERNAL_ERROR;
2476: enc = &newkey->enc;
2477: mac = &newkey->mac;
2478: comp = &newkey->comp;
2479: cc = (mode == MODE_OUT) ? &ssh->state->send_context :
2480: &ssh->state->receive_context;
2481: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2482: return r;
2483: if ((b = sshbuf_new()) == NULL)
2484: return SSH_ERR_ALLOC_FAIL;
2485: /* The cipher struct is constant and shared, you export pointer */
2486: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2487: (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2488: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2489: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2490: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2491: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2492: goto out;
2493: if (cipher_authlen(enc->cipher) == 0) {
2494: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2495: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2496: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2497: goto out;
2498: }
2499: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2500: (r = sshbuf_put_u32(b, comp->enabled)) != 0 ||
2501: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2502: goto out;
2503: r = sshbuf_put_stringb(m, b);
2504: out:
1.221 mmcc 2505: sshbuf_free(b);
1.201 markus 2506: return r;
2507: }
2508:
2509: /* serialize packet state into a blob */
2510: int
2511: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2512: {
2513: struct session_state *state = ssh->state;
2514: u_char *p;
2515: size_t slen, rlen;
2516: int r, ssh1cipher;
2517:
2518: if (!compat20) {
2519: ssh1cipher = cipher_get_number(state->receive_context.cipher);
2520: slen = cipher_get_keyiv_len(&state->send_context);
2521: rlen = cipher_get_keyiv_len(&state->receive_context);
2522: if ((r = sshbuf_put_u32(m, state->remote_protocol_flags)) != 0 ||
2523: (r = sshbuf_put_u32(m, ssh1cipher)) != 0 ||
2524: (r = sshbuf_put_string(m, state->ssh1_key, state->ssh1_keylen)) != 0 ||
2525: (r = sshbuf_put_u32(m, slen)) != 0 ||
2526: (r = sshbuf_reserve(m, slen, &p)) != 0 ||
2527: (r = cipher_get_keyiv(&state->send_context, p, slen)) != 0 ||
2528: (r = sshbuf_put_u32(m, rlen)) != 0 ||
2529: (r = sshbuf_reserve(m, rlen, &p)) != 0 ||
2530: (r = cipher_get_keyiv(&state->receive_context, p, rlen)) != 0)
2531: return r;
2532: } else {
2533: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2534: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2535: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
1.224 dtucker 2536: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
1.208 markus 2537: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
1.201 markus 2538: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2539: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2540: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2541: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2542: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2543: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2544: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
2545: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0)
2546: return r;
2547: }
2548:
2549: slen = cipher_get_keycontext(&state->send_context, NULL);
2550: rlen = cipher_get_keycontext(&state->receive_context, NULL);
2551: if ((r = sshbuf_put_u32(m, slen)) != 0 ||
2552: (r = sshbuf_reserve(m, slen, &p)) != 0)
2553: return r;
2554: if (cipher_get_keycontext(&state->send_context, p) != (int)slen)
2555: return SSH_ERR_INTERNAL_ERROR;
2556: if ((r = sshbuf_put_u32(m, rlen)) != 0 ||
2557: (r = sshbuf_reserve(m, rlen, &p)) != 0)
2558: return r;
2559: if (cipher_get_keycontext(&state->receive_context, p) != (int)rlen)
2560: return SSH_ERR_INTERNAL_ERROR;
2561:
2562: if ((r = ssh_packet_get_compress_state(m, ssh)) != 0 ||
2563: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2564: (r = sshbuf_put_stringb(m, state->output)) != 0)
2565: return r;
2566:
2567: return 0;
2568: }
2569:
2570: /* restore key exchange results from blob for packet state de-serialization */
2571: static int
2572: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2573: {
2574: struct sshbuf *b = NULL;
2575: struct sshcomp *comp;
2576: struct sshenc *enc;
2577: struct sshmac *mac;
2578: struct newkeys *newkey = NULL;
2579: size_t keylen, ivlen, maclen;
2580: int r;
2581:
2582: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2583: r = SSH_ERR_ALLOC_FAIL;
2584: goto out;
2585: }
2586: if ((r = sshbuf_froms(m, &b)) != 0)
2587: goto out;
2588: #ifdef DEBUG_PK
2589: sshbuf_dump(b, stderr);
2590: #endif
2591: enc = &newkey->enc;
2592: mac = &newkey->mac;
2593: comp = &newkey->comp;
2594:
2595: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2596: (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2597: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2598: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2599: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2600: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2601: goto out;
2602: if (cipher_authlen(enc->cipher) == 0) {
2603: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2604: goto out;
2605: if ((r = mac_setup(mac, mac->name)) != 0)
2606: goto out;
2607: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2608: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2609: goto out;
2610: if (maclen > mac->key_len) {
2611: r = SSH_ERR_INVALID_FORMAT;
2612: goto out;
2613: }
2614: mac->key_len = maclen;
2615: }
2616: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2617: (r = sshbuf_get_u32(b, (u_int *)&comp->enabled)) != 0 ||
2618: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2619: goto out;
2620: if (enc->name == NULL ||
2621: cipher_by_name(enc->name) != enc->cipher) {
2622: r = SSH_ERR_INVALID_FORMAT;
2623: goto out;
2624: }
2625: if (sshbuf_len(b) != 0) {
2626: r = SSH_ERR_INVALID_FORMAT;
2627: goto out;
2628: }
2629: enc->key_len = keylen;
2630: enc->iv_len = ivlen;
2631: ssh->kex->newkeys[mode] = newkey;
2632: newkey = NULL;
2633: r = 0;
2634: out:
1.219 mmcc 2635: free(newkey);
1.221 mmcc 2636: sshbuf_free(b);
1.201 markus 2637: return r;
2638: }
2639:
2640: /* restore kex from blob for packet state de-serialization */
2641: static int
2642: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2643: {
2644: struct kex *kex;
2645: int r;
2646:
2647: if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2648: (kex->my = sshbuf_new()) == NULL ||
2649: (kex->peer = sshbuf_new()) == NULL) {
2650: r = SSH_ERR_ALLOC_FAIL;
2651: goto out;
2652: }
2653: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2654: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2655: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2656: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2657: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2658: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2659: (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2660: (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2661: (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2662: goto out;
2663: kex->server = 1;
2664: kex->done = 1;
2665: r = 0;
2666: out:
2667: if (r != 0 || kexp == NULL) {
2668: if (kex != NULL) {
1.221 mmcc 2669: sshbuf_free(kex->my);
2670: sshbuf_free(kex->peer);
1.201 markus 2671: free(kex);
2672: }
2673: if (kexp != NULL)
2674: *kexp = NULL;
2675: } else {
2676: *kexp = kex;
2677: }
2678: return r;
2679: }
2680:
2681: /*
2682: * Restore packet state from content of blob 'm' (de-serialization).
2683: * Note that 'm' will be partially consumed on parsing or any other errors.
2684: */
2685: int
2686: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2687: {
2688: struct session_state *state = ssh->state;
2689: const u_char *ssh1key, *ivin, *ivout, *keyin, *keyout, *input, *output;
2690: size_t ssh1keylen, rlen, slen, ilen, olen;
2691: int r;
2692: u_int ssh1cipher = 0;
2693:
2694: if (!compat20) {
2695: if ((r = sshbuf_get_u32(m, &state->remote_protocol_flags)) != 0 ||
2696: (r = sshbuf_get_u32(m, &ssh1cipher)) != 0 ||
2697: (r = sshbuf_get_string_direct(m, &ssh1key, &ssh1keylen)) != 0 ||
2698: (r = sshbuf_get_string_direct(m, &ivout, &slen)) != 0 ||
2699: (r = sshbuf_get_string_direct(m, &ivin, &rlen)) != 0)
2700: return r;
2701: if (ssh1cipher > INT_MAX)
2702: return SSH_ERR_KEY_UNKNOWN_CIPHER;
2703: ssh_packet_set_encryption_key(ssh, ssh1key, ssh1keylen,
2704: (int)ssh1cipher);
2705: if (cipher_get_keyiv_len(&state->send_context) != (int)slen ||
2706: cipher_get_keyiv_len(&state->receive_context) != (int)rlen)
2707: return SSH_ERR_INVALID_FORMAT;
2708: if ((r = cipher_set_keyiv(&state->send_context, ivout)) != 0 ||
2709: (r = cipher_set_keyiv(&state->receive_context, ivin)) != 0)
2710: return r;
2711: } else {
2712: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2713: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2714: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
1.224 dtucker 2715: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
1.208 markus 2716: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
1.201 markus 2717: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2718: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2719: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2720: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2721: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2722: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2723: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2724: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2725: return r;
1.208 markus 2726: /*
2727: * We set the time here so that in post-auth privsep slave we
2728: * count from the completion of the authentication.
2729: */
2730: state->rekey_time = monotime();
1.201 markus 2731: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2732: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2733: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2734: return r;
2735: }
2736: if ((r = sshbuf_get_string_direct(m, &keyout, &slen)) != 0 ||
2737: (r = sshbuf_get_string_direct(m, &keyin, &rlen)) != 0)
2738: return r;
2739: if (cipher_get_keycontext(&state->send_context, NULL) != (int)slen ||
2740: cipher_get_keycontext(&state->receive_context, NULL) != (int)rlen)
2741: return SSH_ERR_INVALID_FORMAT;
2742: cipher_set_keycontext(&state->send_context, keyout);
2743: cipher_set_keycontext(&state->receive_context, keyin);
2744:
2745: if ((r = ssh_packet_set_compress_state(ssh, m)) != 0 ||
2746: (r = ssh_packet_set_postauth(ssh)) != 0)
2747: return r;
2748:
2749: sshbuf_reset(state->input);
2750: sshbuf_reset(state->output);
2751: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2752: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2753: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2754: (r = sshbuf_put(state->output, output, olen)) != 0)
2755: return r;
2756:
2757: if (sshbuf_len(m))
2758: return SSH_ERR_INVALID_FORMAT;
2759: debug3("%s: done", __func__);
2760: return 0;
2761: }
2762:
2763: /* NEW API */
2764:
2765: /* put data to the outgoing packet */
2766:
2767: int
2768: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2769: {
2770: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2771: }
2772:
2773: int
2774: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2775: {
2776: return sshbuf_putb(ssh->state->outgoing_packet, b);
2777: }
2778:
2779: int
2780: sshpkt_put_u8(struct ssh *ssh, u_char val)
2781: {
2782: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2783: }
2784:
2785: int
2786: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2787: {
2788: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2789: }
2790:
2791: int
2792: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2793: {
2794: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2795: }
2796:
2797: int
2798: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2799: {
2800: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2801: }
2802:
2803: int
2804: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2805: {
2806: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2807: }
2808:
2809: int
2810: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2811: {
2812: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2813: }
2814:
1.211 djm 2815: #ifdef WITH_OPENSSL
1.201 markus 2816: int
2817: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2818: {
2819: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2820: }
2821:
1.211 djm 2822: #ifdef WITH_SSH1
1.201 markus 2823: int
2824: sshpkt_put_bignum1(struct ssh *ssh, const BIGNUM *v)
2825: {
2826: return sshbuf_put_bignum1(ssh->state->outgoing_packet, v);
2827: }
1.211 djm 2828: #endif /* WITH_SSH1 */
1.201 markus 2829:
2830: int
2831: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2832: {
2833: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2834: }
1.211 djm 2835: #endif /* WITH_OPENSSL */
1.201 markus 2836:
2837: /* fetch data from the incoming packet */
2838:
2839: int
2840: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2841: {
2842: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2843: }
2844:
2845: int
2846: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2847: {
2848: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2849: }
2850:
2851: int
2852: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2853: {
2854: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2855: }
2856:
2857: int
2858: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2859: {
2860: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2861: }
2862:
2863: int
2864: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2865: {
2866: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2867: }
2868:
2869: int
2870: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2871: {
2872: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2873: }
2874:
2875: int
2876: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2877: {
2878: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2879: }
2880:
1.211 djm 2881: #ifdef WITH_OPENSSL
1.201 markus 2882: int
2883: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2884: {
2885: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2886: }
2887:
1.211 djm 2888: #ifdef WITH_SSH1
1.201 markus 2889: int
2890: sshpkt_get_bignum1(struct ssh *ssh, BIGNUM *v)
2891: {
2892: return sshbuf_get_bignum1(ssh->state->incoming_packet, v);
2893: }
1.211 djm 2894: #endif /* WITH_SSH1 */
1.201 markus 2895:
2896: int
2897: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2898: {
2899: return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2900: }
1.211 djm 2901: #endif /* WITH_OPENSSL */
1.201 markus 2902:
2903: int
2904: sshpkt_get_end(struct ssh *ssh)
2905: {
2906: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2907: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2908: return 0;
2909: }
2910:
2911: const u_char *
2912: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2913: {
2914: if (lenp != NULL)
2915: *lenp = sshbuf_len(ssh->state->incoming_packet);
2916: return sshbuf_ptr(ssh->state->incoming_packet);
2917: }
2918:
2919: /* start a new packet */
2920:
2921: int
2922: sshpkt_start(struct ssh *ssh, u_char type)
2923: {
2924: u_char buf[9];
2925: int len;
2926:
2927: DBG(debug("packet_start[%d]", type));
2928: len = compat20 ? 6 : 9;
2929: memset(buf, 0, len - 1);
2930: buf[len - 1] = type;
2931: sshbuf_reset(ssh->state->outgoing_packet);
2932: return sshbuf_put(ssh->state->outgoing_packet, buf, len);
2933: }
2934:
2935: /* send it */
2936:
2937: int
2938: sshpkt_send(struct ssh *ssh)
2939: {
2940: if (compat20)
2941: return ssh_packet_send2(ssh);
2942: else
2943: return ssh_packet_send1(ssh);
2944: }
2945:
2946: int
2947: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2948: {
2949: char buf[1024];
2950: va_list args;
2951: int r;
2952:
2953: va_start(args, fmt);
2954: vsnprintf(buf, sizeof(buf), fmt, args);
2955: va_end(args);
2956:
2957: if (compat20) {
2958: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2959: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2960: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2961: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2962: (r = sshpkt_send(ssh)) != 0)
2963: return r;
2964: } else {
2965: if ((r = sshpkt_start(ssh, SSH_MSG_DISCONNECT)) != 0 ||
2966: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2967: (r = sshpkt_send(ssh)) != 0)
2968: return r;
1.166 andreas 2969: }
1.201 markus 2970: return 0;
2971: }
2972:
2973: /* roundup current message to pad bytes */
2974: int
2975: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2976: {
2977: ssh->state->extra_pad = pad;
2978: return 0;
1.1 deraadt 2979: }
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