Annotation of src/usr.bin/ssh/packet.c, Revision 1.242
1.242 ! markus 1: /* $OpenBSD: packet.c,v 1.241 2016/09/28 21:44:52 djm Exp $ */
1.1 deraadt 2: /*
1.15 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.35 deraadt 6: * This file contains code implementing the packet protocol and communication
7: * with the other side. This same code is used both on client and server side.
1.29 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
1.29 markus 14: *
1.25 markus 15: *
16: * SSH2 packet format added by Markus Friedl.
1.69 markus 17: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.25 markus 18: *
1.35 deraadt 19: * Redistribution and use in source and binary forms, with or without
20: * modification, are permitted provided that the following conditions
21: * are met:
22: * 1. Redistributions of source code must retain the above copyright
23: * notice, this list of conditions and the following disclaimer.
24: * 2. Redistributions in binary form must reproduce the above copyright
25: * notice, this list of conditions and the following disclaimer in the
26: * documentation and/or other materials provided with the distribution.
27: *
28: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15 deraadt 38: */
1.1 deraadt 39:
1.142 deraadt 40: #include <sys/types.h>
1.105 markus 41: #include <sys/queue.h>
1.132 stevesk 42: #include <sys/socket.h>
1.138 stevesk 43: #include <sys/time.h>
1.132 stevesk 44: #include <netinet/in.h>
1.121 stevesk 45: #include <netinet/ip.h>
1.134 stevesk 46:
1.135 stevesk 47: #include <errno.h>
1.230 djm 48: #include <netdb.h>
1.134 stevesk 49: #include <stdarg.h>
1.141 stevesk 50: #include <stdio.h>
1.140 stevesk 51: #include <stdlib.h>
1.137 stevesk 52: #include <string.h>
1.136 stevesk 53: #include <unistd.h>
1.203 deraadt 54: #include <limits.h>
1.142 deraadt 55: #include <signal.h>
1.184 dtucker 56: #include <time.h>
1.1 deraadt 57:
1.201 markus 58: #include <zlib.h>
59:
60: #include "buffer.h" /* typedefs XXX */
61: #include "key.h" /* typedefs XXX */
62:
1.1 deraadt 63: #include "xmalloc.h"
64: #include "crc32.h"
1.9 dugsong 65: #include "deattack.h"
1.25 markus 66: #include "compat.h"
1.45 markus 67: #include "ssh1.h"
1.25 markus 68: #include "ssh2.h"
1.37 markus 69: #include "cipher.h"
1.201 markus 70: #include "sshkey.h"
1.25 markus 71: #include "kex.h"
1.200 markus 72: #include "digest.h"
1.50 markus 73: #include "mac.h"
1.46 markus 74: #include "log.h"
75: #include "canohost.h"
1.87 stevesk 76: #include "misc.h"
1.198 millert 77: #include "channels.h"
1.95 markus 78: #include "ssh.h"
1.201 markus 79: #include "packet.h"
1.197 djm 80: #include "ssherr.h"
1.201 markus 81: #include "sshbuf.h"
1.25 markus 82:
83: #ifdef PACKET_DEBUG
84: #define DBG(x) x
85: #else
86: #define DBG(x)
87: #endif
88:
1.159 markus 89: #define PACKET_MAX_SIZE (256 * 1024)
90:
1.161 andreas 91: struct packet_state {
92: u_int32_t seqnr;
93: u_int32_t packets;
94: u_int64_t blocks;
95: u_int64_t bytes;
96: };
97:
98: struct packet {
99: TAILQ_ENTRY(packet) next;
100: u_char type;
1.201 markus 101: struct sshbuf *payload;
1.161 andreas 102: };
103:
104: struct session_state {
105: /*
106: * This variable contains the file descriptors used for
107: * communicating with the other side. connection_in is used for
108: * reading; connection_out for writing. These can be the same
109: * descriptor, in which case it is assumed to be a socket.
110: */
111: int connection_in;
112: int connection_out;
113:
114: /* Protocol flags for the remote side. */
115: u_int remote_protocol_flags;
1.1 deraadt 116:
1.161 andreas 117: /* Encryption context for receiving data. Only used for decryption. */
1.235 djm 118: struct sshcipher_ctx *receive_context;
1.1 deraadt 119:
1.161 andreas 120: /* Encryption context for sending data. Only used for encryption. */
1.235 djm 121: struct sshcipher_ctx *send_context;
1.14 markus 122:
1.161 andreas 123: /* Buffer for raw input data from the socket. */
1.201 markus 124: struct sshbuf *input;
1.1 deraadt 125:
1.161 andreas 126: /* Buffer for raw output data going to the socket. */
1.201 markus 127: struct sshbuf *output;
1.1 deraadt 128:
1.161 andreas 129: /* Buffer for the partial outgoing packet being constructed. */
1.201 markus 130: struct sshbuf *outgoing_packet;
1.1 deraadt 131:
1.161 andreas 132: /* Buffer for the incoming packet currently being processed. */
1.201 markus 133: struct sshbuf *incoming_packet;
1.1 deraadt 134:
1.161 andreas 135: /* Scratch buffer for packet compression/decompression. */
1.201 markus 136: struct sshbuf *compression_buffer;
137:
138: /* Incoming/outgoing compression dictionaries */
139: z_stream compression_in_stream;
140: z_stream compression_out_stream;
141: int compression_in_started;
142: int compression_out_started;
143: int compression_in_failures;
144: int compression_out_failures;
1.1 deraadt 145:
1.161 andreas 146: /*
147: * Flag indicating whether packet compression/decompression is
148: * enabled.
149: */
150: int packet_compression;
1.1 deraadt 151:
1.161 andreas 152: /* default maximum packet size */
153: u_int max_packet_size;
1.1 deraadt 154:
1.161 andreas 155: /* Flag indicating whether this module has been initialized. */
156: int initialized;
1.12 markus 157:
1.161 andreas 158: /* Set to true if the connection is interactive. */
159: int interactive_mode;
1.1 deraadt 160:
1.161 andreas 161: /* Set to true if we are the server side. */
162: int server_side;
1.1 deraadt 163:
1.161 andreas 164: /* Set to true if we are authenticated. */
165: int after_authentication;
1.118 markus 166:
1.161 andreas 167: int keep_alive_timeouts;
1.118 markus 168:
1.161 andreas 169: /* The maximum time that we will wait to send or receive a packet */
170: int packet_timeout_ms;
1.151 dtucker 171:
1.161 andreas 172: /* Session key information for Encryption and MAC */
1.201 markus 173: struct newkeys *newkeys[MODE_MAX];
1.161 andreas 174: struct packet_state p_read, p_send;
1.154 dtucker 175:
1.184 dtucker 176: /* Volume-based rekeying */
1.224 dtucker 177: u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
1.105 markus 178:
1.184 dtucker 179: /* Time-based rekeying */
1.208 markus 180: u_int32_t rekey_interval; /* how often in seconds */
1.184 dtucker 181: time_t rekey_time; /* time of last rekeying */
182:
1.161 andreas 183: /* Session key for protocol v1 */
184: u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
185: u_int ssh1_keylen;
1.25 markus 186:
1.161 andreas 187: /* roundup current message to extra_pad bytes */
188: u_char extra_pad;
1.95 markus 189:
1.161 andreas 190: /* XXX discard incoming data after MAC error */
191: u_int packet_discard;
1.234 markus 192: size_t packet_discard_mac_already;
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:
1.242 ! markus 201: /* Used in ssh_packet_send_mux() */
! 202: int mux;
! 203:
1.165 andreas 204: /* Used in packet_set_interactive */
205: int set_interactive_called;
206:
207: /* Used in packet_set_maxsize */
208: int set_maxsize_called;
209:
1.201 markus 210: /* One-off warning about weak ciphers */
211: int cipher_warning_done;
212:
213: /* SSH1 CRC compensation attack detector */
214: struct deattack_ctx deattack;
215:
1.161 andreas 216: TAILQ_HEAD(, packet) outgoing;
1.105 markus 217: };
1.161 andreas 218:
1.201 markus 219: struct ssh *
220: ssh_alloc_session_state(void)
1.161 andreas 221: {
1.201 markus 222: struct ssh *ssh = NULL;
223: struct session_state *state = NULL;
1.161 andreas 224:
1.201 markus 225: if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
226: (state = calloc(1, sizeof(*state))) == NULL ||
227: (state->input = sshbuf_new()) == NULL ||
228: (state->output = sshbuf_new()) == NULL ||
229: (state->outgoing_packet = sshbuf_new()) == NULL ||
230: (state->incoming_packet = sshbuf_new()) == NULL)
231: goto fail;
232: TAILQ_INIT(&state->outgoing);
1.202 markus 233: TAILQ_INIT(&ssh->private_keys);
234: TAILQ_INIT(&ssh->public_keys);
1.201 markus 235: state->connection_in = -1;
236: state->connection_out = -1;
237: state->max_packet_size = 32768;
238: state->packet_timeout_ms = -1;
239: state->p_send.packets = state->p_read.packets = 0;
240: state->initialized = 1;
241: /*
242: * ssh_packet_send2() needs to queue packets until
243: * we've done the initial key exchange.
244: */
245: state->rekeying = 1;
246: ssh->state = state;
247: return ssh;
248: fail:
249: if (state) {
250: sshbuf_free(state->input);
251: sshbuf_free(state->output);
252: sshbuf_free(state->incoming_packet);
253: sshbuf_free(state->outgoing_packet);
254: free(state);
255: }
256: free(ssh);
257: return NULL;
1.161 andreas 258: }
1.105 markus 259:
1.228 djm 260: /* Returns nonzero if rekeying is in progress */
261: int
262: ssh_packet_is_rekeying(struct ssh *ssh)
263: {
1.229 djm 264: return compat20 &&
265: (ssh->state->rekeying || (ssh->kex != NULL && ssh->kex->done == 0));
1.228 djm 266: }
267:
1.16 markus 268: /*
269: * Sets the descriptors used for communication. Disables encryption until
270: * packet_set_encryption_key is called.
271: */
1.201 markus 272: struct ssh *
273: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1 deraadt 274: {
1.201 markus 275: struct session_state *state;
276: const struct sshcipher *none = cipher_by_name("none");
1.197 djm 277: int r;
1.97 deraadt 278:
1.205 djm 279: if (none == NULL) {
280: error("%s: cannot load cipher 'none'", __func__);
281: return NULL;
282: }
1.201 markus 283: if (ssh == NULL)
284: ssh = ssh_alloc_session_state();
1.205 djm 285: if (ssh == NULL) {
286: error("%s: cound not allocate state", __func__);
287: return NULL;
288: }
1.201 markus 289: state = ssh->state;
290: state->connection_in = fd_in;
291: state->connection_out = fd_out;
292: if ((r = cipher_init(&state->send_context, none,
1.197 djm 293: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201 markus 294: (r = cipher_init(&state->receive_context, none,
1.205 djm 295: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
296: error("%s: cipher_init failed: %s", __func__, ssh_err(r));
1.230 djm 297: free(ssh); /* XXX need ssh_free_session_state? */
1.205 djm 298: return NULL;
299: }
1.201 markus 300: state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
301: deattack_init(&state->deattack);
1.207 djm 302: /*
303: * Cache the IP address of the remote connection for use in error
304: * messages that might be generated after the connection has closed.
305: */
306: (void)ssh_remote_ipaddr(ssh);
1.201 markus 307: return ssh;
1.1 deraadt 308: }
309:
1.154 dtucker 310: void
1.201 markus 311: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 312: {
1.201 markus 313: struct session_state *state = ssh->state;
314:
1.174 djm 315: if (timeout <= 0 || count <= 0) {
1.201 markus 316: state->packet_timeout_ms = -1;
1.154 dtucker 317: return;
318: }
319: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 320: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 321: else
1.201 markus 322: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 323: }
324:
1.242 ! markus 325: void
! 326: ssh_packet_set_mux(struct ssh *ssh)
! 327: {
! 328: ssh->state->mux = 1;
! 329: ssh->state->rekeying = 0;
! 330: }
! 331:
! 332: int
! 333: ssh_packet_get_mux(struct ssh *ssh)
! 334: {
! 335: return ssh->state->mux;
! 336: }
! 337:
1.201 markus 338: int
339: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 340: {
1.201 markus 341: struct session_state *state = ssh->state;
342: int r;
343:
344: if (state->packet_discard_mac) {
1.159 markus 345: char buf[1024];
1.234 markus 346: size_t dlen = PACKET_MAX_SIZE;
1.201 markus 347:
1.234 markus 348: if (dlen > state->packet_discard_mac_already)
349: dlen -= state->packet_discard_mac_already;
1.159 markus 350: memset(buf, 'a', sizeof(buf));
1.234 markus 351: while (sshbuf_len(state->incoming_packet) < dlen)
1.201 markus 352: if ((r = sshbuf_put(state->incoming_packet, buf,
353: sizeof(buf))) != 0)
354: return r;
355: (void) mac_compute(state->packet_discard_mac,
356: state->p_read.seqnr,
1.234 markus 357: sshbuf_ptr(state->incoming_packet), dlen,
1.201 markus 358: NULL, 0);
1.159 markus 359: }
1.220 djm 360: logit("Finished discarding for %.200s port %d",
361: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 362: return SSH_ERR_MAC_INVALID;
1.159 markus 363: }
364:
1.201 markus 365: static int
366: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
1.234 markus 367: struct sshmac *mac, size_t mac_already, u_int discard)
1.159 markus 368: {
1.201 markus 369: struct session_state *state = ssh->state;
370: int r;
371:
372: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
373: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
374: return r;
375: return SSH_ERR_MAC_INVALID;
376: }
1.234 markus 377: /*
378: * Record number of bytes over which the mac has already
379: * been computed in order to minimize timing attacks.
380: */
381: if (mac && mac->enabled) {
1.201 markus 382: state->packet_discard_mac = mac;
1.234 markus 383: state->packet_discard_mac_already = mac_already;
384: }
385: if (sshbuf_len(state->input) >= discard)
386: return ssh_packet_stop_discard(ssh);
1.201 markus 387: state->packet_discard = discard - sshbuf_len(state->input);
388: return 0;
1.159 markus 389: }
390:
1.19 markus 391: /* Returns 1 if remote host is connected via socket, 0 if not. */
392:
393: int
1.201 markus 394: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 395: {
1.201 markus 396: struct session_state *state = ssh->state;
1.19 markus 397: struct sockaddr_storage from, to;
398: socklen_t fromlen, tolen;
399:
1.230 djm 400: if (state->connection_in == -1 || state->connection_out == -1)
401: return 0;
402:
1.19 markus 403: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 404: if (state->connection_in == state->connection_out)
1.19 markus 405: return 1;
406: fromlen = sizeof(from);
407: memset(&from, 0, sizeof(from));
1.201 markus 408: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.161 andreas 409: &fromlen) < 0)
1.19 markus 410: return 0;
411: tolen = sizeof(to);
412: memset(&to, 0, sizeof(to));
1.201 markus 413: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.161 andreas 414: &tolen) < 0)
1.19 markus 415: return 0;
416: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
417: return 0;
418: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
419: return 0;
420: return 1;
421: }
422:
1.91 markus 423: void
1.201 markus 424: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 425: {
1.201 markus 426: if (ibytes)
427: *ibytes = ssh->state->p_read.bytes;
428: if (obytes)
429: *obytes = ssh->state->p_send.bytes;
1.91 markus 430: }
1.125 deraadt 431:
1.91 markus 432: int
1.201 markus 433: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 434: {
435: struct sockaddr_storage to;
1.21 deraadt 436: socklen_t tolen = sizeof(to);
1.19 markus 437:
438: memset(&to, 0, sizeof(to));
1.201 markus 439: if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
1.161 andreas 440: &tolen) < 0)
1.19 markus 441: return 0;
1.173 djm 442: return to.ss_family;
1.19 markus 443: }
444:
1.1 deraadt 445: /* Sets the connection into non-blocking mode. */
446:
1.2 provos 447: void
1.201 markus 448: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 449: {
1.14 markus 450: /* Set the socket into non-blocking mode. */
1.201 markus 451: set_nonblock(ssh->state->connection_in);
1.14 markus 452:
1.201 markus 453: if (ssh->state->connection_out != ssh->state->connection_in)
454: set_nonblock(ssh->state->connection_out);
1.1 deraadt 455: }
456:
457: /* Returns the socket used for reading. */
458:
1.2 provos 459: int
1.201 markus 460: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 461: {
1.201 markus 462: return ssh->state->connection_in;
1.1 deraadt 463: }
464:
465: /* Returns the descriptor used for writing. */
466:
1.2 provos 467: int
1.201 markus 468: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 469: {
1.201 markus 470: return ssh->state->connection_out;
471: }
472:
473: /*
474: * Returns the IP-address of the remote host as a string. The returned
475: * string must not be freed.
476: */
477:
478: const char *
479: ssh_remote_ipaddr(struct ssh *ssh)
480: {
1.220 djm 481: const int sock = ssh->state->connection_in;
482:
1.201 markus 483: /* Check whether we have cached the ipaddr. */
1.220 djm 484: if (ssh->remote_ipaddr == NULL) {
485: if (ssh_packet_connection_is_on_socket(ssh)) {
486: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 djm 487: ssh->remote_port = get_peer_port(sock);
488: ssh->local_ipaddr = get_local_ipaddr(sock);
489: ssh->local_port = get_local_port(sock);
1.220 djm 490: } else {
491: ssh->remote_ipaddr = strdup("UNKNOWN");
1.230 djm 492: ssh->remote_port = 65535;
493: ssh->local_ipaddr = strdup("UNKNOWN");
494: ssh->local_port = 65535;
1.220 djm 495: }
496: }
1.201 markus 497: return ssh->remote_ipaddr;
1.1 deraadt 498: }
499:
1.220 djm 500: /* Returns the port number of the remote host. */
501:
502: int
503: ssh_remote_port(struct ssh *ssh)
504: {
505: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
506: return ssh->remote_port;
1.230 djm 507: }
508:
509: /*
510: * Returns the IP-address of the local host as a string. The returned
511: * string must not be freed.
512: */
513:
514: const char *
515: ssh_local_ipaddr(struct ssh *ssh)
516: {
517: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
518: return ssh->local_ipaddr;
519: }
520:
521: /* Returns the port number of the local host. */
522:
523: int
524: ssh_local_port(struct ssh *ssh)
525: {
526: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
527: return ssh->local_port;
1.220 djm 528: }
529:
1.1 deraadt 530: /* Closes the connection and clears and frees internal data structures. */
531:
1.2 provos 532: void
1.201 markus 533: ssh_packet_close(struct ssh *ssh)
1.1 deraadt 534: {
1.201 markus 535: struct session_state *state = ssh->state;
536: u_int mode;
537:
538: if (!state->initialized)
1.14 markus 539: return;
1.201 markus 540: state->initialized = 0;
541: if (state->connection_in == state->connection_out) {
542: shutdown(state->connection_out, SHUT_RDWR);
543: close(state->connection_out);
1.14 markus 544: } else {
1.201 markus 545: close(state->connection_in);
546: close(state->connection_out);
1.14 markus 547: }
1.201 markus 548: sshbuf_free(state->input);
549: sshbuf_free(state->output);
550: sshbuf_free(state->outgoing_packet);
551: sshbuf_free(state->incoming_packet);
552: for (mode = 0; mode < MODE_MAX; mode++)
553: kex_free_newkeys(state->newkeys[mode]);
554: if (state->compression_buffer) {
555: sshbuf_free(state->compression_buffer);
556: if (state->compression_out_started) {
557: z_streamp stream = &state->compression_out_stream;
558: debug("compress outgoing: "
559: "raw data %llu, compressed %llu, factor %.2f",
560: (unsigned long long)stream->total_in,
561: (unsigned long long)stream->total_out,
562: stream->total_in == 0 ? 0.0 :
563: (double) stream->total_out / stream->total_in);
564: if (state->compression_out_failures == 0)
565: deflateEnd(stream);
566: }
567: if (state->compression_in_started) {
568: z_streamp stream = &state->compression_out_stream;
569: debug("compress incoming: "
570: "raw data %llu, compressed %llu, factor %.2f",
571: (unsigned long long)stream->total_out,
572: (unsigned long long)stream->total_in,
573: stream->total_out == 0 ? 0.0 :
574: (double) stream->total_in / stream->total_out);
575: if (state->compression_in_failures == 0)
576: inflateEnd(stream);
577: }
1.14 markus 578: }
1.235 djm 579: cipher_free(state->send_context);
580: cipher_free(state->receive_context);
581: state->send_context = state->receive_context = NULL;
1.219 mmcc 582: free(ssh->remote_ipaddr);
583: ssh->remote_ipaddr = NULL;
1.201 markus 584: free(ssh->state);
585: ssh->state = NULL;
1.1 deraadt 586: }
587:
588: /* Sets remote side protocol flags. */
589:
1.2 provos 590: void
1.201 markus 591: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 592: {
1.201 markus 593: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 594: }
595:
596: /* Returns the remote protocol flags set earlier by the above function. */
597:
1.40 markus 598: u_int
1.201 markus 599: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 600: {
1.201 markus 601: return ssh->state->remote_protocol_flags;
1.1 deraadt 602: }
603:
1.16 markus 604: /*
605: * Starts packet compression from the next packet on in both directions.
606: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
607: */
1.1 deraadt 608:
1.201 markus 609: static int
610: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 611: {
1.201 markus 612: if (!ssh->state->compression_buffer &&
613: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
614: return SSH_ERR_ALLOC_FAIL;
615: return 0;
1.60 markus 616: }
617:
1.201 markus 618: static int
619: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 620: {
1.201 markus 621: if (level < 1 || level > 9)
622: return SSH_ERR_INVALID_ARGUMENT;
623: debug("Enabling compression at level %d.", level);
624: if (ssh->state->compression_out_started == 1)
625: deflateEnd(&ssh->state->compression_out_stream);
626: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
627: case Z_OK:
628: ssh->state->compression_out_started = 1;
629: break;
630: case Z_MEM_ERROR:
631: return SSH_ERR_ALLOC_FAIL;
632: default:
633: return SSH_ERR_INTERNAL_ERROR;
634: }
635: return 0;
1.1 deraadt 636: }
637:
1.201 markus 638: static int
639: start_compression_in(struct ssh *ssh)
640: {
641: if (ssh->state->compression_in_started == 1)
642: inflateEnd(&ssh->state->compression_in_stream);
643: switch (inflateInit(&ssh->state->compression_in_stream)) {
644: case Z_OK:
645: ssh->state->compression_in_started = 1;
646: break;
647: case Z_MEM_ERROR:
648: return SSH_ERR_ALLOC_FAIL;
649: default:
650: return SSH_ERR_INTERNAL_ERROR;
651: }
652: return 0;
653: }
1.95 markus 654:
1.201 markus 655: int
656: ssh_packet_start_compression(struct ssh *ssh, int level)
1.1 deraadt 657: {
1.197 djm 658: int r;
1.97 deraadt 659:
1.201 markus 660: if (ssh->state->packet_compression && !compat20)
661: return SSH_ERR_INTERNAL_ERROR;
662: ssh->state->packet_compression = 1;
663: if ((r = ssh_packet_init_compression(ssh)) != 0 ||
664: (r = start_compression_in(ssh)) != 0 ||
665: (r = start_compression_out(ssh, level)) != 0)
666: return r;
667: return 0;
1.95 markus 668: }
669:
1.201 markus 670: /* XXX remove need for separate compression buffer */
671: static int
672: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 673: {
1.201 markus 674: u_char buf[4096];
675: int r, status;
676:
677: if (ssh->state->compression_out_started != 1)
678: return SSH_ERR_INTERNAL_ERROR;
679:
680: /* This case is not handled below. */
681: if (sshbuf_len(in) == 0)
682: return 0;
683:
684: /* Input is the contents of the input buffer. */
685: if ((ssh->state->compression_out_stream.next_in =
686: sshbuf_mutable_ptr(in)) == NULL)
687: return SSH_ERR_INTERNAL_ERROR;
688: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
689:
690: /* Loop compressing until deflate() returns with avail_out != 0. */
691: do {
692: /* Set up fixed-size output buffer. */
693: ssh->state->compression_out_stream.next_out = buf;
694: ssh->state->compression_out_stream.avail_out = sizeof(buf);
695:
696: /* Compress as much data into the buffer as possible. */
697: status = deflate(&ssh->state->compression_out_stream,
698: Z_PARTIAL_FLUSH);
699: switch (status) {
700: case Z_MEM_ERROR:
701: return SSH_ERR_ALLOC_FAIL;
702: case Z_OK:
703: /* Append compressed data to output_buffer. */
704: if ((r = sshbuf_put(out, buf, sizeof(buf) -
705: ssh->state->compression_out_stream.avail_out)) != 0)
706: return r;
707: break;
708: case Z_STREAM_ERROR:
709: default:
710: ssh->state->compression_out_failures++;
711: return SSH_ERR_INVALID_FORMAT;
712: }
713: } while (ssh->state->compression_out_stream.avail_out == 0);
714: return 0;
1.1 deraadt 715: }
716:
1.201 markus 717: static int
718: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 719: {
1.201 markus 720: u_char buf[4096];
721: int r, status;
1.1 deraadt 722:
1.201 markus 723: if (ssh->state->compression_in_started != 1)
724: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 725:
1.201 markus 726: if ((ssh->state->compression_in_stream.next_in =
727: sshbuf_mutable_ptr(in)) == NULL)
728: return SSH_ERR_INTERNAL_ERROR;
729: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 730:
1.201 markus 731: for (;;) {
732: /* Set up fixed-size output buffer. */
733: ssh->state->compression_in_stream.next_out = buf;
734: ssh->state->compression_in_stream.avail_out = sizeof(buf);
735:
736: status = inflate(&ssh->state->compression_in_stream,
737: Z_PARTIAL_FLUSH);
738: switch (status) {
739: case Z_OK:
740: if ((r = sshbuf_put(out, buf, sizeof(buf) -
741: ssh->state->compression_in_stream.avail_out)) != 0)
742: return r;
743: break;
744: case Z_BUF_ERROR:
745: /*
746: * Comments in zlib.h say that we should keep calling
747: * inflate() until we get an error. This appears to
748: * be the error that we get.
749: */
750: return 0;
751: case Z_DATA_ERROR:
752: return SSH_ERR_INVALID_FORMAT;
753: case Z_MEM_ERROR:
754: return SSH_ERR_ALLOC_FAIL;
755: case Z_STREAM_ERROR:
756: default:
757: ssh->state->compression_in_failures++;
758: return SSH_ERR_INTERNAL_ERROR;
759: }
760: }
761: /* NOTREACHED */
1.1 deraadt 762: }
1.125 deraadt 763:
1.201 markus 764: /*
765: * Causes any further packets to be encrypted using the given key. The same
766: * key is used for both sending and reception. However, both directions are
767: * encrypted independently of each other.
768: */
1.125 deraadt 769:
1.2 provos 770: void
1.201 markus 771: ssh_packet_set_encryption_key(struct ssh *ssh, const u_char *key, u_int keylen, int number)
1.1 deraadt 772: {
1.211 djm 773: #ifndef WITH_SSH1
774: fatal("no SSH protocol 1 support");
775: #else /* WITH_SSH1 */
1.201 markus 776: struct session_state *state = ssh->state;
777: const struct sshcipher *cipher = cipher_by_number(number);
778: int r;
779: const char *wmsg;
1.125 deraadt 780:
1.201 markus 781: if (cipher == NULL)
782: fatal("%s: unknown cipher number %d", __func__, number);
783: if (keylen < 20)
784: fatal("%s: keylen too small: %d", __func__, keylen);
785: if (keylen > SSH_SESSION_KEY_LENGTH)
786: fatal("%s: keylen too big: %d", __func__, keylen);
787: memcpy(state->ssh1_key, key, keylen);
788: state->ssh1_keylen = keylen;
789: if ((r = cipher_init(&state->send_context, cipher, key, keylen,
790: NULL, 0, CIPHER_ENCRYPT)) != 0 ||
791: (r = cipher_init(&state->receive_context, cipher, key, keylen,
792: NULL, 0, CIPHER_DECRYPT) != 0))
793: fatal("%s: cipher_init failed: %s", __func__, ssh_err(r));
794: if (!state->cipher_warning_done &&
1.235 djm 795: ((wmsg = cipher_warning_message(state->send_context)) != NULL ||
796: (wmsg = cipher_warning_message(state->send_context)) != NULL)) {
1.201 markus 797: error("Warning: %s", wmsg);
798: state->cipher_warning_done = 1;
799: }
1.211 djm 800: #endif /* WITH_SSH1 */
1.170 djm 801: }
802:
1.16 markus 803: /*
804: * Finalizes and sends the packet. If the encryption key has been set,
805: * encrypts the packet before sending.
806: */
1.14 markus 807:
1.201 markus 808: int
809: ssh_packet_send1(struct ssh *ssh)
1.1 deraadt 810: {
1.201 markus 811: struct session_state *state = ssh->state;
1.89 markus 812: u_char buf[8], *cp;
1.201 markus 813: int r, padding, len;
1.40 markus 814: u_int checksum;
1.14 markus 815:
1.16 markus 816: /*
817: * If using packet compression, compress the payload of the outgoing
818: * packet.
819: */
1.201 markus 820: if (state->packet_compression) {
821: sshbuf_reset(state->compression_buffer);
1.14 markus 822: /* Skip padding. */
1.201 markus 823: if ((r = sshbuf_consume(state->outgoing_packet, 8)) != 0)
824: goto out;
1.14 markus 825: /* padding */
1.201 markus 826: if ((r = sshbuf_put(state->compression_buffer,
827: "\0\0\0\0\0\0\0\0", 8)) != 0)
828: goto out;
829: if ((r = compress_buffer(ssh, state->outgoing_packet,
830: state->compression_buffer)) != 0)
831: goto out;
832: sshbuf_reset(state->outgoing_packet);
833: if ((r = sshbuf_putb(state->outgoing_packet,
834: state->compression_buffer)) != 0)
835: goto out;
1.14 markus 836: }
837: /* Compute packet length without padding (add checksum, remove padding). */
1.201 markus 838: len = sshbuf_len(state->outgoing_packet) + 4 - 8;
1.14 markus 839:
1.32 markus 840: /* Insert padding. Initialized to zero in packet_start1() */
1.14 markus 841: padding = 8 - len % 8;
1.235 djm 842: if (!cipher_ctx_is_plaintext(state->send_context)) {
1.201 markus 843: cp = sshbuf_mutable_ptr(state->outgoing_packet);
844: if (cp == NULL) {
845: r = SSH_ERR_INTERNAL_ERROR;
846: goto out;
1.14 markus 847: }
1.201 markus 848: arc4random_buf(cp + 8 - padding, padding);
1.14 markus 849: }
1.201 markus 850: if ((r = sshbuf_consume(state->outgoing_packet, 8 - padding)) != 0)
851: goto out;
1.14 markus 852:
853: /* Add check bytes. */
1.201 markus 854: checksum = ssh_crc32(sshbuf_ptr(state->outgoing_packet),
855: sshbuf_len(state->outgoing_packet));
856: POKE_U32(buf, checksum);
857: if ((r = sshbuf_put(state->outgoing_packet, buf, 4)) != 0)
858: goto out;
1.1 deraadt 859:
860: #ifdef PACKET_DEBUG
1.14 markus 861: fprintf(stderr, "packet_send plain: ");
1.201 markus 862: sshbuf_dump(state->outgoing_packet, stderr);
1.1 deraadt 863: #endif
864:
1.14 markus 865: /* Append to output. */
1.201 markus 866: POKE_U32(buf, len);
867: if ((r = sshbuf_put(state->output, buf, 4)) != 0)
868: goto out;
869: if ((r = sshbuf_reserve(state->output,
870: sshbuf_len(state->outgoing_packet), &cp)) != 0)
871: goto out;
1.235 djm 872: if ((r = cipher_crypt(state->send_context, 0, cp,
1.201 markus 873: sshbuf_ptr(state->outgoing_packet),
874: sshbuf_len(state->outgoing_packet), 0, 0)) != 0)
875: goto out;
1.14 markus 876:
1.1 deraadt 877: #ifdef PACKET_DEBUG
1.14 markus 878: fprintf(stderr, "encrypted: ");
1.201 markus 879: sshbuf_dump(state->output, stderr);
1.1 deraadt 880: #endif
1.201 markus 881: state->p_send.packets++;
882: state->p_send.bytes += len +
883: sshbuf_len(state->outgoing_packet);
884: sshbuf_reset(state->outgoing_packet);
1.1 deraadt 885:
1.16 markus 886: /*
1.120 djm 887: * Note that the packet is now only buffered in output. It won't be
1.205 djm 888: * actually sent until ssh_packet_write_wait or ssh_packet_write_poll
889: * is called.
1.16 markus 890: */
1.201 markus 891: r = 0;
892: out:
893: return r;
1.1 deraadt 894: }
895:
1.201 markus 896: int
897: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 898: {
1.201 markus 899: struct session_state *state = ssh->state;
900: struct sshenc *enc;
901: struct sshmac *mac;
902: struct sshcomp *comp;
1.235 djm 903: struct sshcipher_ctx **ccp;
1.236 markus 904: struct packet_state *ps;
1.105 markus 905: u_int64_t *max_blocks;
1.236 markus 906: const char *wmsg, *dir;
1.197 djm 907: int r, crypt_type;
1.57 markus 908:
1.100 markus 909: debug2("set_newkeys: mode %d", mode);
1.57 markus 910:
1.88 markus 911: if (mode == MODE_OUT) {
1.236 markus 912: dir = "output";
1.235 djm 913: ccp = &state->send_context;
1.115 avsm 914: crypt_type = CIPHER_ENCRYPT;
1.236 markus 915: ps = &state->p_send;
1.201 markus 916: max_blocks = &state->max_blocks_out;
1.88 markus 917: } else {
1.236 markus 918: dir = "input";
1.235 djm 919: ccp = &state->receive_context;
1.115 avsm 920: crypt_type = CIPHER_DECRYPT;
1.236 markus 921: ps = &state->p_read;
1.201 markus 922: max_blocks = &state->max_blocks_in;
1.88 markus 923: }
1.201 markus 924: if (state->newkeys[mode] != NULL) {
1.236 markus 925: debug("%s: rekeying after %llu %s blocks"
926: " (%llu bytes total)", __func__,
927: (unsigned long long)ps->blocks, dir,
928: (unsigned long long)ps->bytes);
1.235 djm 929: cipher_free(*ccp);
930: *ccp = NULL;
1.201 markus 931: enc = &state->newkeys[mode]->enc;
932: mac = &state->newkeys[mode]->mac;
933: comp = &state->newkeys[mode]->comp;
1.148 pvalchev 934: mac_clear(mac);
1.192 djm 935: explicit_bzero(enc->iv, enc->iv_len);
936: explicit_bzero(enc->key, enc->key_len);
937: explicit_bzero(mac->key, mac->key_len);
1.186 djm 938: free(enc->name);
939: free(enc->iv);
940: free(enc->key);
941: free(mac->name);
942: free(mac->key);
943: free(comp->name);
1.201 markus 944: free(state->newkeys[mode]);
1.57 markus 945: }
1.236 markus 946: /* note that both bytes and the seqnr are not reset */
947: ps->packets = ps->blocks = 0;
1.201 markus 948: /* move newkeys from kex to state */
949: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
950: return SSH_ERR_INTERNAL_ERROR;
951: ssh->kex->newkeys[mode] = NULL;
952: enc = &state->newkeys[mode]->enc;
953: mac = &state->newkeys[mode]->mac;
954: comp = &state->newkeys[mode]->comp;
955: if (cipher_authlen(enc->cipher) == 0) {
956: if ((r = mac_init(mac)) != 0)
957: return r;
958: }
959: mac->enabled = 1;
1.57 markus 960: DBG(debug("cipher_init_context: %d", mode));
1.235 djm 961: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 962: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 963: return r;
964: if (!state->cipher_warning_done &&
1.235 djm 965: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 966: error("Warning: %s", wmsg);
967: state->cipher_warning_done = 1;
968: }
1.91 markus 969: /* Deleting the keys does not gain extra security */
1.192 djm 970: /* explicit_bzero(enc->iv, enc->block_size);
971: explicit_bzero(enc->key, enc->key_len);
972: explicit_bzero(mac->key, mac->key_len); */
1.241 djm 973: if ((comp->type == COMP_ZLIB ||
974: (comp->type == COMP_DELAYED &&
975: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 976: if ((r = ssh_packet_init_compression(ssh)) < 0)
977: return r;
978: if (mode == MODE_OUT) {
979: if ((r = start_compression_out(ssh, 6)) != 0)
980: return r;
981: } else {
982: if ((r = start_compression_in(ssh)) != 0)
983: return r;
984: }
1.57 markus 985: comp->enabled = 1;
986: }
1.109 markus 987: /*
988: * The 2^(blocksize*2) limit is too expensive for 3DES,
989: * blowfish, etc, so enforce a 1GB limit for small blocksizes.
990: */
991: if (enc->block_size >= 16)
992: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
993: else
994: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 995: if (state->rekey_limit)
1.237 deraadt 996: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 997: state->rekey_limit / enc->block_size);
1.227 djm 998: debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1.201 markus 999: return 0;
1.57 markus 1000: }
1001:
1.228 djm 1002: #define MAX_PACKETS (1U<<31)
1003: static int
1004: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
1005: {
1006: struct session_state *state = ssh->state;
1007: u_int32_t out_blocks;
1008:
1009: /* XXX client can't cope with rekeying pre-auth */
1010: if (!state->after_authentication)
1011: return 0;
1012:
1013: /* Haven't keyed yet or KEX in progress. */
1014: if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
1015: return 0;
1016:
1017: /* Peer can't rekey */
1018: if (ssh->compat & SSH_BUG_NOREKEY)
1019: return 0;
1020:
1021: /*
1022: * Permit one packet in or out per rekey - this allows us to
1023: * make progress when rekey limits are very small.
1024: */
1025: if (state->p_send.packets == 0 && state->p_read.packets == 0)
1026: return 0;
1027:
1028: /* Time-based rekeying */
1029: if (state->rekey_interval != 0 &&
1030: state->rekey_time + state->rekey_interval <= monotime())
1031: return 1;
1032:
1033: /* Always rekey when MAX_PACKETS sent in either direction */
1034: if (state->p_send.packets > MAX_PACKETS ||
1035: state->p_read.packets > MAX_PACKETS)
1036: return 1;
1037:
1038: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 1039: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 1040: state->newkeys[MODE_OUT]->enc.block_size);
1041: return (state->max_blocks_out &&
1042: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
1043: (state->max_blocks_in &&
1044: (state->p_read.blocks > state->max_blocks_in));
1045: }
1046:
1.16 markus 1047: /*
1.118 markus 1048: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 1049: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 1050: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
1051: */
1.201 markus 1052: static int
1053: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 1054: {
1.201 markus 1055: struct session_state *state = ssh->state;
1056: struct sshcomp *comp = NULL;
1057: int r, mode;
1.118 markus 1058:
1059: /*
1060: * Remember that we are past the authentication step, so rekeying
1061: * with COMP_DELAYED will turn on compression immediately.
1062: */
1.201 markus 1063: state->after_authentication = 1;
1.118 markus 1064: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 1065: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 1066: if (state->newkeys[mode] == NULL)
1.145 markus 1067: continue;
1.201 markus 1068: comp = &state->newkeys[mode]->comp;
1.118 markus 1069: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 1070: if ((r = ssh_packet_init_compression(ssh)) != 0)
1071: return r;
1072: if (mode == MODE_OUT) {
1073: if ((r = start_compression_out(ssh, 6)) != 0)
1074: return r;
1075: } else {
1076: if ((r = start_compression_in(ssh)) != 0)
1077: return r;
1078: }
1.118 markus 1079: comp->enabled = 1;
1080: }
1081: }
1.201 markus 1082: return 0;
1.118 markus 1083: }
1084:
1.226 djm 1085: /* Used to mute debug logging for noisy packet types */
1.242 ! markus 1086: int
1.226 djm 1087: ssh_packet_log_type(u_char type)
1088: {
1089: switch (type) {
1090: case SSH2_MSG_CHANNEL_DATA:
1091: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1092: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1093: return 0;
1094: default:
1095: return 1;
1096: }
1097: }
1098:
1.118 markus 1099: /*
1.25 markus 1100: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1101: */
1.201 markus 1102: int
1103: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1104: {
1.201 markus 1105: struct session_state *state = ssh->state;
1.200 markus 1106: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1107: u_char tmp, padlen, pad = 0;
1.201 markus 1108: u_int authlen = 0, aadlen = 0;
1109: u_int len;
1110: struct sshenc *enc = NULL;
1111: struct sshmac *mac = NULL;
1112: struct sshcomp *comp = NULL;
1113: int r, block_size;
1114:
1115: if (state->newkeys[MODE_OUT] != NULL) {
1116: enc = &state->newkeys[MODE_OUT]->enc;
1117: mac = &state->newkeys[MODE_OUT]->mac;
1118: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1119: /* disable mac for authenticated encryption */
1120: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1121: mac = NULL;
1.25 markus 1122: }
1.88 markus 1123: block_size = enc ? enc->block_size : 8;
1.180 markus 1124: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1125:
1.201 markus 1126: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1127: if (ssh_packet_log_type(type))
1128: debug3("send packet: type %u", type);
1.25 markus 1129: #ifdef PACKET_DEBUG
1130: fprintf(stderr, "plain: ");
1.201 markus 1131: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1132: #endif
1133:
1134: if (comp && comp->enabled) {
1.201 markus 1135: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1136: /* skip header, compress only payload */
1.201 markus 1137: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1138: goto out;
1139: sshbuf_reset(state->compression_buffer);
1140: if ((r = compress_buffer(ssh, state->outgoing_packet,
1141: state->compression_buffer)) != 0)
1142: goto out;
1143: sshbuf_reset(state->outgoing_packet);
1144: if ((r = sshbuf_put(state->outgoing_packet,
1145: "\0\0\0\0\0", 5)) != 0 ||
1146: (r = sshbuf_putb(state->outgoing_packet,
1147: state->compression_buffer)) != 0)
1148: goto out;
1149: DBG(debug("compression: raw %d compressed %zd", len,
1150: sshbuf_len(state->outgoing_packet)));
1.25 markus 1151: }
1152:
1153: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1154: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1155:
1156: /*
1157: * calc size of padding, alloc space, get random data,
1158: * minimum padding is 4 bytes
1159: */
1.178 markus 1160: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1161: padlen = block_size - (len % block_size);
1162: if (padlen < 4)
1163: padlen += block_size;
1.201 markus 1164: if (state->extra_pad) {
1.233 djm 1165: tmp = state->extra_pad;
1.201 markus 1166: state->extra_pad =
1.237 deraadt 1167: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1168: /* check if roundup overflowed */
1169: if (state->extra_pad < tmp)
1170: return SSH_ERR_INVALID_ARGUMENT;
1171: tmp = (len + padlen) % state->extra_pad;
1172: /* Check whether pad calculation below will underflow */
1173: if (tmp > state->extra_pad)
1174: return SSH_ERR_INVALID_ARGUMENT;
1175: pad = state->extra_pad - tmp;
1.193 djm 1176: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1177: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1178: tmp = padlen;
1.71 markus 1179: padlen += pad;
1.233 djm 1180: /* Check whether padlen calculation overflowed */
1181: if (padlen < tmp)
1182: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1183: state->extra_pad = 0;
1.71 markus 1184: }
1.201 markus 1185: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1186: goto out;
1.235 djm 1187: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1188: /* random padding */
1.201 markus 1189: arc4random_buf(cp, padlen);
1.32 markus 1190: } else {
1191: /* clear padding */
1.192 djm 1192: explicit_bzero(cp, padlen);
1.25 markus 1193: }
1.178 markus 1194: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1195: len = sshbuf_len(state->outgoing_packet);
1196: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1197: if (cp == NULL) {
1198: r = SSH_ERR_INTERNAL_ERROR;
1199: goto out;
1200: }
1.25 markus 1201: /* packet_length includes payload, padding and padding length field */
1.201 markus 1202: POKE_U32(cp, len - 4);
1.89 markus 1203: cp[4] = padlen;
1.178 markus 1204: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1205: len, padlen, aadlen));
1.25 markus 1206:
1207: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1208: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1209: if ((r = mac_compute(mac, state->p_send.seqnr,
1210: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1211: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1212: goto out;
1213: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1214: }
1215: /* encrypt packet and append to output buffer. */
1.201 markus 1216: if ((r = sshbuf_reserve(state->output,
1217: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1218: goto out;
1.235 djm 1219: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1220: sshbuf_ptr(state->outgoing_packet),
1221: len - aadlen, aadlen, authlen)) != 0)
1222: goto out;
1.25 markus 1223: /* append unencrypted MAC */
1.178 markus 1224: if (mac && mac->enabled) {
1225: if (mac->etm) {
1226: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1227: if ((r = mac_compute(mac, state->p_send.seqnr,
1228: cp, len, macbuf, sizeof(macbuf))) != 0)
1229: goto out;
1.178 markus 1230: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1231: state->p_send.seqnr));
1.178 markus 1232: }
1.201 markus 1233: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1234: goto out;
1.178 markus 1235: }
1.25 markus 1236: #ifdef PACKET_DEBUG
1237: fprintf(stderr, "encrypted: ");
1.201 markus 1238: sshbuf_dump(state->output, stderr);
1.25 markus 1239: #endif
1.29 markus 1240: /* increment sequence number for outgoing packets */
1.201 markus 1241: if (++state->p_send.seqnr == 0)
1.106 itojun 1242: logit("outgoing seqnr wraps around");
1.201 markus 1243: if (++state->p_send.packets == 0)
1244: if (!(ssh->compat & SSH_BUG_NOREKEY))
1245: return SSH_ERR_NEED_REKEY;
1246: state->p_send.blocks += len / block_size;
1247: state->p_send.bytes += len;
1248: sshbuf_reset(state->outgoing_packet);
1.25 markus 1249:
1.57 markus 1250: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1251: r = ssh_set_newkeys(ssh, MODE_OUT);
1252: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1253: r = ssh_packet_enable_delayed_compress(ssh);
1254: else
1255: r = 0;
1256: out:
1257: return r;
1.25 markus 1258: }
1259:
1.228 djm 1260: /* returns non-zero if the specified packet type is usec by KEX */
1261: static int
1262: ssh_packet_type_is_kex(u_char type)
1263: {
1264: return
1265: type >= SSH2_MSG_TRANSPORT_MIN &&
1266: type <= SSH2_MSG_TRANSPORT_MAX &&
1267: type != SSH2_MSG_SERVICE_REQUEST &&
1268: type != SSH2_MSG_SERVICE_ACCEPT &&
1269: type != SSH2_MSG_EXT_INFO;
1270: }
1271:
1.201 markus 1272: int
1273: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1274: {
1.201 markus 1275: struct session_state *state = ssh->state;
1.105 markus 1276: struct packet *p;
1.201 markus 1277: u_char type;
1.228 djm 1278: int r, need_rekey;
1.105 markus 1279:
1.228 djm 1280: if (sshbuf_len(state->outgoing_packet) < 6)
1281: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1282: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1283: need_rekey = !ssh_packet_type_is_kex(type) &&
1284: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1285:
1.228 djm 1286: /*
1287: * During rekeying we can only send key exchange messages.
1288: * Queue everything else.
1289: */
1290: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1291: if (need_rekey)
1292: debug3("%s: rekex triggered", __func__);
1293: debug("enqueue packet: %u", type);
1294: p = calloc(1, sizeof(*p));
1295: if (p == NULL)
1296: return SSH_ERR_ALLOC_FAIL;
1297: p->type = type;
1298: p->payload = state->outgoing_packet;
1299: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1300: state->outgoing_packet = sshbuf_new();
1301: if (state->outgoing_packet == NULL)
1302: return SSH_ERR_ALLOC_FAIL;
1303: if (need_rekey) {
1304: /*
1305: * This packet triggered a rekey, so send the
1306: * KEXINIT now.
1307: * NB. reenters this function via kex_start_rekex().
1308: */
1309: return kex_start_rekex(ssh);
1.105 markus 1310: }
1.228 djm 1311: return 0;
1.105 markus 1312: }
1313:
1314: /* rekeying starts with sending KEXINIT */
1315: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1316: state->rekeying = 1;
1.105 markus 1317:
1.201 markus 1318: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1319: return r;
1.105 markus 1320:
1321: /* after a NEWKEYS message we can send the complete queue */
1322: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1323: state->rekeying = 0;
1324: state->rekey_time = monotime();
1325: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1326: type = p->type;
1.228 djm 1327: /*
1328: * If this packet triggers a rekex, then skip the
1329: * remaining packets in the queue for now.
1330: * NB. re-enters this function via kex_start_rekex.
1331: */
1332: if (ssh_packet_need_rekeying(ssh,
1333: sshbuf_len(p->payload))) {
1334: debug3("%s: queued packet triggered rekex",
1335: __func__);
1336: return kex_start_rekex(ssh);
1337: }
1.105 markus 1338: debug("dequeue packet: %u", type);
1.201 markus 1339: sshbuf_free(state->outgoing_packet);
1340: state->outgoing_packet = p->payload;
1341: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1342: memset(p, 0, sizeof(*p));
1.186 djm 1343: free(p);
1.201 markus 1344: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1345: return r;
1.105 markus 1346: }
1347: }
1.201 markus 1348: return 0;
1.25 markus 1349: }
1350:
1351: /*
1.16 markus 1352: * Waits until a packet has been received, and returns its type. Note that
1353: * no other data is processed until this returns, so this function should not
1354: * be used during the interactive session.
1355: */
1.1 deraadt 1356:
1.2 provos 1357: int
1.201 markus 1358: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1359: {
1.201 markus 1360: struct session_state *state = ssh->state;
1.222 markus 1361: int len, r, ms_remain;
1.56 millert 1362: fd_set *setp;
1.14 markus 1363: char buf[8192];
1.155 deraadt 1364: struct timeval timeout, start, *timeoutp = NULL;
1365:
1.25 markus 1366: DBG(debug("packet_read()"));
1.14 markus 1367:
1.214 deraadt 1368: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1369: NFDBITS), sizeof(fd_mask));
1.201 markus 1370: if (setp == NULL)
1371: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1372:
1.205 djm 1373: /*
1374: * Since we are blocking, ensure that all written packets have
1375: * been sent.
1376: */
1.210 markus 1377: if ((r = ssh_packet_write_wait(ssh)) != 0)
1378: goto out;
1.14 markus 1379:
1380: /* Stay in the loop until we have received a complete packet. */
1381: for (;;) {
1382: /* Try to read a packet from the buffer. */
1.201 markus 1383: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1384: if (r != 0)
1385: break;
1.62 markus 1386: if (!compat20 && (
1.201 markus 1387: *typep == SSH_SMSG_SUCCESS
1388: || *typep == SSH_SMSG_FAILURE
1389: || *typep == SSH_CMSG_EOF
1390: || *typep == SSH_CMSG_EXIT_CONFIRMATION))
1391: if ((r = sshpkt_get_end(ssh)) != 0)
1392: break;
1.14 markus 1393: /* If we got a packet, return it. */
1.201 markus 1394: if (*typep != SSH_MSG_NONE)
1395: break;
1.16 markus 1396: /*
1397: * Otherwise, wait for some data to arrive, add it to the
1398: * buffer, and try again.
1399: */
1.201 markus 1400: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1401: NFDBITS) * sizeof(fd_mask));
1.201 markus 1402: FD_SET(state->connection_in, setp);
1.16 markus 1403:
1.201 markus 1404: if (state->packet_timeout_ms > 0) {
1405: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1406: timeoutp = &timeout;
1407: }
1.14 markus 1408: /* Wait for some data to arrive. */
1.154 dtucker 1409: for (;;) {
1.201 markus 1410: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1411: ms_to_timeval(&timeout, ms_remain);
1412: gettimeofday(&start, NULL);
1413: }
1.201 markus 1414: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1415: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1416: break;
1.161 andreas 1417: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1418: break;
1.201 markus 1419: if (state->packet_timeout_ms == -1)
1.154 dtucker 1420: continue;
1421: ms_subtract_diff(&start, &ms_remain);
1422: if (ms_remain <= 0) {
1.201 markus 1423: r = 0;
1.154 dtucker 1424: break;
1425: }
1426: }
1.204 djm 1427: if (r == 0)
1428: return SSH_ERR_CONN_TIMEOUT;
1.14 markus 1429: /* Read data from the socket. */
1.222 markus 1430: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1431: if (len == 0) {
1432: r = SSH_ERR_CONN_CLOSED;
1433: goto out;
1434: }
1435: if (len < 0) {
1436: r = SSH_ERR_SYSTEM_ERROR;
1437: goto out;
1438: }
1.204 djm 1439:
1.14 markus 1440: /* Append it to the buffer. */
1.204 djm 1441: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1442: goto out;
1.14 markus 1443: }
1.210 markus 1444: out:
1.201 markus 1445: free(setp);
1446: return r;
1.1 deraadt 1447: }
1448:
1.77 djm 1449: int
1.201 markus 1450: ssh_packet_read(struct ssh *ssh)
1.77 djm 1451: {
1.201 markus 1452: u_char type;
1453: int r;
1454:
1455: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1456: fatal("%s: %s", __func__, ssh_err(r));
1457: return type;
1.77 djm 1458: }
1459:
1.16 markus 1460: /*
1461: * Waits until a packet has been received, verifies that its type matches
1462: * that given, and gives a fatal error and exits if there is a mismatch.
1463: */
1.1 deraadt 1464:
1.205 djm 1465: int
1466: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1467: {
1.205 djm 1468: int r;
1469: u_char type;
1.1 deraadt 1470:
1.205 djm 1471: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1472: return r;
1473: if (type != expected_type) {
1474: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1475: "Protocol error: expected packet type %d, got %d",
1.205 djm 1476: expected_type, type)) != 0)
1477: return r;
1478: return SSH_ERR_PROTOCOL_ERROR;
1479: }
1480: return 0;
1.1 deraadt 1481: }
1482:
1483: /* Checks if a full packet is available in the data received so far via
1.14 markus 1484: * packet_process_incoming. If so, reads the packet; otherwise returns
1485: * SSH_MSG_NONE. This does not wait for data from the connection.
1486: *
1.150 dtucker 1487: * SSH_MSG_DISCONNECT is handled specially here. Also,
1488: * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1489: * to higher levels.
1.14 markus 1490: */
1.1 deraadt 1491:
1.201 markus 1492: int
1493: ssh_packet_read_poll1(struct ssh *ssh, u_char *typep)
1.1 deraadt 1494: {
1.201 markus 1495: struct session_state *state = ssh->state;
1.40 markus 1496: u_int len, padded_len;
1.205 djm 1497: const char *emsg;
1.201 markus 1498: const u_char *cp;
1499: u_char *p;
1.40 markus 1500: u_int checksum, stored_checksum;
1.201 markus 1501: int r;
1502:
1503: *typep = SSH_MSG_NONE;
1.14 markus 1504:
1505: /* Check if input size is less than minimum packet size. */
1.201 markus 1506: if (sshbuf_len(state->input) < 4 + 8)
1507: return 0;
1.14 markus 1508: /* Get length of incoming packet. */
1.201 markus 1509: len = PEEK_U32(sshbuf_ptr(state->input));
1.205 djm 1510: if (len < 1 + 2 + 2 || len > 256 * 1024) {
1511: if ((r = sshpkt_disconnect(ssh, "Bad packet length %u",
1512: len)) != 0)
1513: return r;
1514: return SSH_ERR_CONN_CORRUPT;
1515: }
1.14 markus 1516: padded_len = (len + 8) & ~7;
1517:
1518: /* Check if the packet has been entirely received. */
1.201 markus 1519: if (sshbuf_len(state->input) < 4 + padded_len)
1520: return 0;
1.14 markus 1521:
1522: /* The entire packet is in buffer. */
1523:
1524: /* Consume packet length. */
1.201 markus 1525: if ((r = sshbuf_consume(state->input, 4)) != 0)
1526: goto out;
1.14 markus 1527:
1.62 markus 1528: /*
1529: * Cryptographic attack detector for ssh
1530: * (C)1998 CORE-SDI, Buenos Aires Argentina
1531: * Ariel Futoransky(futo@core-sdi.com)
1532: */
1.235 djm 1533: if (!cipher_ctx_is_plaintext(state->receive_context)) {
1.205 djm 1534: emsg = NULL;
1.201 markus 1535: switch (detect_attack(&state->deattack,
1536: sshbuf_ptr(state->input), padded_len)) {
1537: case DEATTACK_OK:
1538: break;
1.144 djm 1539: case DEATTACK_DETECTED:
1.205 djm 1540: emsg = "crc32 compensation attack detected";
1541: break;
1.144 djm 1542: case DEATTACK_DOS_DETECTED:
1.205 djm 1543: emsg = "deattack denial of service detected";
1544: break;
1.201 markus 1545: default:
1.205 djm 1546: emsg = "deattack error";
1547: break;
1548: }
1549: if (emsg != NULL) {
1550: error("%s", emsg);
1551: if ((r = sshpkt_disconnect(ssh, "%s", emsg)) != 0 ||
1552: (r = ssh_packet_write_wait(ssh)) != 0)
1553: return r;
1554: return SSH_ERR_CONN_CORRUPT;
1.144 djm 1555: }
1556: }
1.62 markus 1557:
1558: /* Decrypt data to incoming_packet. */
1.201 markus 1559: sshbuf_reset(state->incoming_packet);
1560: if ((r = sshbuf_reserve(state->incoming_packet, padded_len, &p)) != 0)
1561: goto out;
1.235 djm 1562: if ((r = cipher_crypt(state->receive_context, 0, p,
1.201 markus 1563: sshbuf_ptr(state->input), padded_len, 0, 0)) != 0)
1564: goto out;
1.62 markus 1565:
1.201 markus 1566: if ((r = sshbuf_consume(state->input, padded_len)) != 0)
1567: goto out;
1.1 deraadt 1568:
1569: #ifdef PACKET_DEBUG
1.14 markus 1570: fprintf(stderr, "read_poll plain: ");
1.201 markus 1571: sshbuf_dump(state->incoming_packet, stderr);
1.1 deraadt 1572: #endif
1573:
1.14 markus 1574: /* Compute packet checksum. */
1.201 markus 1575: checksum = ssh_crc32(sshbuf_ptr(state->incoming_packet),
1576: sshbuf_len(state->incoming_packet) - 4);
1.14 markus 1577:
1578: /* Skip padding. */
1.201 markus 1579: if ((r = sshbuf_consume(state->incoming_packet, 8 - len % 8)) != 0)
1580: goto out;
1.14 markus 1581:
1582: /* Test check bytes. */
1.205 djm 1583: if (len != sshbuf_len(state->incoming_packet)) {
1584: error("%s: len %d != sshbuf_len %zd", __func__,
1.201 markus 1585: len, sshbuf_len(state->incoming_packet));
1.205 djm 1586: if ((r = sshpkt_disconnect(ssh, "invalid packet length")) != 0 ||
1587: (r = ssh_packet_write_wait(ssh)) != 0)
1588: return r;
1589: return SSH_ERR_CONN_CORRUPT;
1590: }
1.14 markus 1591:
1.201 markus 1592: cp = sshbuf_ptr(state->incoming_packet) + len - 4;
1593: stored_checksum = PEEK_U32(cp);
1.205 djm 1594: if (checksum != stored_checksum) {
1595: error("Corrupted check bytes on input");
1596: if ((r = sshpkt_disconnect(ssh, "connection corrupted")) != 0 ||
1597: (r = ssh_packet_write_wait(ssh)) != 0)
1598: return r;
1599: return SSH_ERR_CONN_CORRUPT;
1600: }
1.201 markus 1601: if ((r = sshbuf_consume_end(state->incoming_packet, 4)) < 0)
1602: goto out;
1603:
1604: if (state->packet_compression) {
1605: sshbuf_reset(state->compression_buffer);
1606: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1607: state->compression_buffer)) != 0)
1608: goto out;
1609: sshbuf_reset(state->incoming_packet);
1610: if ((r = sshbuf_putb(state->incoming_packet,
1611: state->compression_buffer)) != 0)
1612: goto out;
1613: }
1614: state->p_read.packets++;
1615: state->p_read.bytes += padded_len + 4;
1616: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1617: goto out;
1.205 djm 1618: if (*typep < SSH_MSG_MIN || *typep > SSH_MSG_MAX) {
1619: error("Invalid ssh1 packet type: %d", *typep);
1620: if ((r = sshpkt_disconnect(ssh, "invalid packet type")) != 0 ||
1621: (r = ssh_packet_write_wait(ssh)) != 0)
1622: return r;
1623: return SSH_ERR_PROTOCOL_ERROR;
1624: }
1.201 markus 1625: r = 0;
1626: out:
1627: return r;
1.1 deraadt 1628: }
1.14 markus 1629:
1.242 ! markus 1630: static int
! 1631: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
! 1632: {
! 1633: struct session_state *state = ssh->state;
! 1634: const u_char *cp;
! 1635: size_t need;
! 1636: int r;
! 1637:
! 1638: if (ssh->kex)
! 1639: return SSH_ERR_INTERNAL_ERROR;
! 1640: *typep = SSH_MSG_NONE;
! 1641: cp = sshbuf_ptr(state->input);
! 1642: if (state->packlen == 0) {
! 1643: if (sshbuf_len(state->input) < 4 + 1)
! 1644: return 0; /* packet is incomplete */
! 1645: state->packlen = PEEK_U32(cp);
! 1646: if (state->packlen < 4 + 1 ||
! 1647: state->packlen > PACKET_MAX_SIZE)
! 1648: return SSH_ERR_MESSAGE_INCOMPLETE;
! 1649: }
! 1650: need = state->packlen + 4;
! 1651: if (sshbuf_len(state->input) < need)
! 1652: return 0; /* packet is incomplete */
! 1653: sshbuf_reset(state->incoming_packet);
! 1654: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
! 1655: state->packlen)) != 0 ||
! 1656: (r = sshbuf_consume(state->input, need)) != 0 ||
! 1657: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
! 1658: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
! 1659: return r;
! 1660: if (ssh_packet_log_type(*typep))
! 1661: debug3("%s: type %u", __func__, *typep);
! 1662: /* sshbuf_dump(state->incoming_packet, stderr); */
! 1663: /* reset for next packet */
! 1664: state->packlen = 0;
! 1665: return r;
! 1666: }
! 1667:
1.201 markus 1668: int
1669: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1670: {
1.201 markus 1671: struct session_state *state = ssh->state;
1.40 markus 1672: u_int padlen, need;
1.231 djm 1673: u_char *cp;
1.201 markus 1674: u_int maclen, aadlen = 0, authlen = 0, block_size;
1675: struct sshenc *enc = NULL;
1676: struct sshmac *mac = NULL;
1677: struct sshcomp *comp = NULL;
1.200 markus 1678: int r;
1.201 markus 1679:
1.242 ! markus 1680: if (state->mux)
! 1681: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
! 1682:
1.201 markus 1683: *typep = SSH_MSG_NONE;
1684:
1685: if (state->packet_discard)
1686: return 0;
1687:
1688: if (state->newkeys[MODE_IN] != NULL) {
1689: enc = &state->newkeys[MODE_IN]->enc;
1690: mac = &state->newkeys[MODE_IN]->mac;
1691: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1692: /* disable mac for authenticated encryption */
1693: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1694: mac = NULL;
1.25 markus 1695: }
1696: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1697: block_size = enc ? enc->block_size : 8;
1.180 markus 1698: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1699:
1.201 markus 1700: if (aadlen && state->packlen == 0) {
1.235 djm 1701: if (cipher_get_length(state->receive_context,
1.201 markus 1702: &state->packlen, state->p_read.seqnr,
1703: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1704: return 0;
1705: if (state->packlen < 1 + 4 ||
1706: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1707: #ifdef PACKET_DEBUG
1.201 markus 1708: sshbuf_dump(state->input, stderr);
1.178 markus 1709: #endif
1.201 markus 1710: logit("Bad packet length %u.", state->packlen);
1711: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1712: return r;
1.217 djm 1713: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1714: }
1.201 markus 1715: sshbuf_reset(state->incoming_packet);
1716: } else if (state->packlen == 0) {
1.25 markus 1717: /*
1718: * check if input size is less than the cipher block size,
1719: * decrypt first block and extract length of incoming packet
1720: */
1.201 markus 1721: if (sshbuf_len(state->input) < block_size)
1722: return 0;
1723: sshbuf_reset(state->incoming_packet);
1724: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1725: &cp)) != 0)
1726: goto out;
1.235 djm 1727: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1728: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1729: block_size, 0, 0)) != 0)
1730: goto out;
1731: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1732: if (state->packlen < 1 + 4 ||
1733: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1734: #ifdef PACKET_DEBUG
1.201 markus 1735: fprintf(stderr, "input: \n");
1736: sshbuf_dump(state->input, stderr);
1737: fprintf(stderr, "incoming_packet: \n");
1738: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1739: #endif
1.201 markus 1740: logit("Bad packet length %u.", state->packlen);
1.234 markus 1741: return ssh_packet_start_discard(ssh, enc, mac, 0,
1742: PACKET_MAX_SIZE);
1.25 markus 1743: }
1.201 markus 1744: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1745: goto out;
1.25 markus 1746: }
1.201 markus 1747: DBG(debug("input: packet len %u", state->packlen+4));
1748:
1.178 markus 1749: if (aadlen) {
1750: /* only the payload is encrypted */
1.201 markus 1751: need = state->packlen;
1.178 markus 1752: } else {
1753: /*
1754: * the payload size and the payload are encrypted, but we
1755: * have a partial packet of block_size bytes
1756: */
1.201 markus 1757: need = 4 + state->packlen - block_size;
1.178 markus 1758: }
1.180 markus 1759: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1760: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1761: if (need % block_size != 0) {
1762: logit("padding error: need %d block %d mod %d",
1.25 markus 1763: need, block_size, need % block_size);
1.234 markus 1764: return ssh_packet_start_discard(ssh, enc, mac, 0,
1765: PACKET_MAX_SIZE - block_size);
1.158 markus 1766: }
1.25 markus 1767: /*
1768: * check if the entire packet has been received and
1.178 markus 1769: * decrypt into incoming_packet:
1770: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1771: * 'need' bytes are encrypted, followed by either
1772: * 'authlen' bytes of authentication tag or
1.178 markus 1773: * 'maclen' bytes of message authentication code.
1.25 markus 1774: */
1.201 markus 1775: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1776: return 0; /* packet is incomplete */
1.25 markus 1777: #ifdef PACKET_DEBUG
1778: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1779: sshbuf_dump(state->input, stderr);
1.25 markus 1780: #endif
1.231 djm 1781: /* EtM: check mac over encrypted input */
1.201 markus 1782: if (mac && mac->enabled && mac->etm) {
1.231 djm 1783: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1784: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1785: sshbuf_ptr(state->input) + aadlen + need + authlen,
1786: maclen)) != 0) {
1787: if (r == SSH_ERR_MAC_INVALID)
1788: logit("Corrupted MAC on input.");
1.201 markus 1789: goto out;
1.231 djm 1790: }
1.201 markus 1791: }
1792: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1793: &cp)) != 0)
1794: goto out;
1.235 djm 1795: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1796: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1797: goto out;
1798: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1799: goto out;
1.29 markus 1800: if (mac && mac->enabled) {
1.231 djm 1801: /* Not EtM: check MAC over cleartext */
1802: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1803: sshbuf_ptr(state->incoming_packet),
1804: sshbuf_len(state->incoming_packet),
1805: sshbuf_ptr(state->input), maclen)) != 0) {
1806: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1807: goto out;
1.159 markus 1808: logit("Corrupted MAC on input.");
1809: if (need > PACKET_MAX_SIZE)
1.201 markus 1810: return SSH_ERR_INTERNAL_ERROR;
1811: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1812: sshbuf_len(state->incoming_packet),
1813: PACKET_MAX_SIZE - need);
1.201 markus 1814: }
1.231 djm 1815: /* Remove MAC from input buffer */
1.201 markus 1816: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1817: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1818: goto out;
1.25 markus 1819: }
1.77 djm 1820: if (seqnr_p != NULL)
1.201 markus 1821: *seqnr_p = state->p_read.seqnr;
1822: if (++state->p_read.seqnr == 0)
1.106 itojun 1823: logit("incoming seqnr wraps around");
1.201 markus 1824: if (++state->p_read.packets == 0)
1825: if (!(ssh->compat & SSH_BUG_NOREKEY))
1826: return SSH_ERR_NEED_REKEY;
1827: state->p_read.blocks += (state->packlen + 4) / block_size;
1828: state->p_read.bytes += state->packlen + 4;
1.25 markus 1829:
1830: /* get padlen */
1.201 markus 1831: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1832: DBG(debug("input: padlen %d", padlen));
1.205 djm 1833: if (padlen < 4) {
1834: if ((r = sshpkt_disconnect(ssh,
1835: "Corrupted padlen %d on input.", padlen)) != 0 ||
1836: (r = ssh_packet_write_wait(ssh)) != 0)
1837: return r;
1838: return SSH_ERR_CONN_CORRUPT;
1839: }
1.25 markus 1840:
1841: /* skip packet size + padlen, discard padding */
1.201 markus 1842: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1843: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1844: goto out;
1.25 markus 1845:
1.201 markus 1846: DBG(debug("input: len before de-compress %zd",
1847: sshbuf_len(state->incoming_packet)));
1.25 markus 1848: if (comp && comp->enabled) {
1.201 markus 1849: sshbuf_reset(state->compression_buffer);
1850: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1851: state->compression_buffer)) != 0)
1852: goto out;
1853: sshbuf_reset(state->incoming_packet);
1854: if ((r = sshbuf_putb(state->incoming_packet,
1855: state->compression_buffer)) != 0)
1856: goto out;
1857: DBG(debug("input: len after de-compress %zd",
1858: sshbuf_len(state->incoming_packet)));
1.25 markus 1859: }
1860: /*
1861: * get packet type, implies consume.
1862: * return length of payload (without type field)
1863: */
1.201 markus 1864: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1865: goto out;
1.226 djm 1866: if (ssh_packet_log_type(*typep))
1867: debug3("receive packet: type %u", *typep);
1.205 djm 1868: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1869: if ((r = sshpkt_disconnect(ssh,
1870: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1871: (r = ssh_packet_write_wait(ssh)) != 0)
1872: return r;
1873: return SSH_ERR_PROTOCOL_ERROR;
1874: }
1.238 markus 1875: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1876: r = ssh_packet_enable_delayed_compress(ssh);
1877: else
1878: r = 0;
1.25 markus 1879: #ifdef PACKET_DEBUG
1.201 markus 1880: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1881: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1882: #endif
1.62 markus 1883: /* reset for next packet */
1.201 markus 1884: state->packlen = 0;
1.228 djm 1885:
1886: /* do we need to rekey? */
1887: if (ssh_packet_need_rekeying(ssh, 0)) {
1888: debug3("%s: rekex triggered", __func__);
1889: if ((r = kex_start_rekex(ssh)) != 0)
1890: return r;
1891: }
1.201 markus 1892: out:
1893: return r;
1.25 markus 1894: }
1895:
1896: int
1.201 markus 1897: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1898: {
1.201 markus 1899: struct session_state *state = ssh->state;
1.96 deraadt 1900: u_int reason, seqnr;
1.201 markus 1901: int r;
1902: u_char *msg;
1.62 markus 1903:
1.25 markus 1904: for (;;) {
1.201 markus 1905: msg = NULL;
1.62 markus 1906: if (compat20) {
1.201 markus 1907: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1908: if (r != 0)
1909: return r;
1910: if (*typep) {
1911: state->keep_alive_timeouts = 0;
1912: DBG(debug("received packet type %d", *typep));
1.153 djm 1913: }
1.201 markus 1914: switch (*typep) {
1.150 dtucker 1915: case SSH2_MSG_IGNORE:
1.151 dtucker 1916: debug3("Received SSH2_MSG_IGNORE");
1.150 dtucker 1917: break;
1.25 markus 1918: case SSH2_MSG_DEBUG:
1.201 markus 1919: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1920: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1921: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1.219 mmcc 1922: free(msg);
1.201 markus 1923: return r;
1924: }
1.25 markus 1925: debug("Remote: %.900s", msg);
1.186 djm 1926: free(msg);
1.25 markus 1927: break;
1928: case SSH2_MSG_DISCONNECT:
1.201 markus 1929: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1930: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1931: return r;
1.182 djm 1932: /* Ignore normal client exit notifications */
1.201 markus 1933: do_log2(ssh->state->server_side &&
1.182 djm 1934: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1935: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1.220 djm 1936: "Received disconnect from %s port %d:"
1937: "%u: %.400s", ssh_remote_ipaddr(ssh),
1938: ssh_remote_port(ssh), reason, msg);
1.186 djm 1939: free(msg);
1.201 markus 1940: return SSH_ERR_DISCONNECTED;
1.84 markus 1941: case SSH2_MSG_UNIMPLEMENTED:
1.201 markus 1942: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1943: return r;
1.96 deraadt 1944: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1945: seqnr);
1.150 dtucker 1946: break;
1.25 markus 1947: default:
1.201 markus 1948: return 0;
1.48 stevesk 1949: }
1.25 markus 1950: } else {
1.201 markus 1951: r = ssh_packet_read_poll1(ssh, typep);
1952: switch (*typep) {
1.188 djm 1953: case SSH_MSG_NONE:
1954: return SSH_MSG_NONE;
1.25 markus 1955: case SSH_MSG_IGNORE:
1956: break;
1957: case SSH_MSG_DEBUG:
1.201 markus 1958: if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1959: return r;
1.25 markus 1960: debug("Remote: %.900s", msg);
1.186 djm 1961: free(msg);
1.25 markus 1962: break;
1963: case SSH_MSG_DISCONNECT:
1.201 markus 1964: if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1965: return r;
1.220 djm 1966: error("Received disconnect from %s port %d: "
1967: "%.400s", ssh_remote_ipaddr(ssh),
1968: ssh_remote_port(ssh), msg);
1.201 markus 1969: free(msg);
1970: return SSH_ERR_DISCONNECTED;
1.25 markus 1971: default:
1.201 markus 1972: DBG(debug("received packet type %d", *typep));
1973: return 0;
1.48 stevesk 1974: }
1.25 markus 1975: }
1976: }
1977: }
1978:
1.16 markus 1979: /*
1980: * Buffers the given amount of input characters. This is intended to be used
1981: * together with packet_read_poll.
1982: */
1.1 deraadt 1983:
1.204 djm 1984: int
1.201 markus 1985: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1986: {
1.201 markus 1987: struct session_state *state = ssh->state;
1988: int r;
1989:
1990: if (state->packet_discard) {
1991: state->keep_alive_timeouts = 0; /* ?? */
1992: if (len >= state->packet_discard) {
1993: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1994: return r;
1.201 markus 1995: }
1996: state->packet_discard -= len;
1.204 djm 1997: return 0;
1.159 markus 1998: }
1.201 markus 1999: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 2000: return r;
2001:
2002: return 0;
1.28 markus 2003: }
2004:
2005: int
1.201 markus 2006: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 2007: {
1.201 markus 2008: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 2009: }
2010:
1.16 markus 2011: /*
2012: * Sends a diagnostic message from the server to the client. This message
2013: * can be sent at any time (but not while constructing another message). The
2014: * message is printed immediately, but only if the client is being executed
2015: * in verbose mode. These messages are primarily intended to ease debugging
2016: * authentication problems. The length of the formatted message must not
1.205 djm 2017: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 2018: */
1.2 provos 2019: void
1.201 markus 2020: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 2021: {
1.14 markus 2022: char buf[1024];
2023: va_list args;
1.201 markus 2024: int r;
1.39 markus 2025:
1.201 markus 2026: if (compat20 && (ssh->compat & SSH_BUG_DEBUG))
1.39 markus 2027: return;
1.14 markus 2028:
2029: va_start(args, fmt);
2030: vsnprintf(buf, sizeof(buf), fmt, args);
2031: va_end(args);
2032:
1.30 markus 2033: if (compat20) {
1.201 markus 2034: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
2035: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
2036: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2037: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2038: (r = sshpkt_send(ssh)) != 0)
2039: fatal("%s: %s", __func__, ssh_err(r));
1.30 markus 2040: } else {
1.201 markus 2041: if ((r = sshpkt_start(ssh, SSH_MSG_DEBUG)) != 0 ||
2042: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2043: (r = sshpkt_send(ssh)) != 0)
2044: fatal("%s: %s", __func__, ssh_err(r));
1.30 markus 2045: }
1.205 djm 2046: if ((r = ssh_packet_write_wait(ssh)) != 0)
2047: fatal("%s: %s", __func__, ssh_err(r));
2048: }
2049:
2050: /*
2051: * Pretty-print connection-terminating errors and exit.
2052: */
2053: void
2054: sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
2055: {
2056: switch (r) {
2057: case SSH_ERR_CONN_CLOSED:
1.232 dtucker 2058: logdie("Connection closed by %.200s port %d",
1.220 djm 2059: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.205 djm 2060: case SSH_ERR_CONN_TIMEOUT:
1.232 dtucker 2061: logdie("Connection %s %.200s port %d timed out",
1.220 djm 2062: ssh->state->server_side ? "from" : "to",
2063: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.212 djm 2064: case SSH_ERR_DISCONNECTED:
1.232 dtucker 2065: logdie("Disconnected from %.200s port %d",
1.220 djm 2066: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.212 djm 2067: case SSH_ERR_SYSTEM_ERROR:
1.232 dtucker 2068: if (errno == ECONNRESET)
2069: logdie("Connection reset by %.200s port %d",
1.220 djm 2070: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.213 djm 2071: /* FALLTHROUGH */
2072: case SSH_ERR_NO_CIPHER_ALG_MATCH:
2073: case SSH_ERR_NO_MAC_ALG_MATCH:
2074: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
2075: case SSH_ERR_NO_KEX_ALG_MATCH:
2076: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
2077: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.232 dtucker 2078: logdie("Unable to negotiate with %.200s port %d: %s. "
1.213 djm 2079: "Their offer: %s", ssh_remote_ipaddr(ssh),
1.220 djm 2080: ssh_remote_port(ssh), ssh_err(r),
2081: ssh->kex->failed_choice);
1.212 djm 2082: }
2083: /* FALLTHROUGH */
1.205 djm 2084: default:
1.232 dtucker 2085: logdie("%s%sConnection %s %.200s port %d: %s",
1.205 djm 2086: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 2087: ssh->state->server_side ? "from" : "to",
2088: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), ssh_err(r));
1.205 djm 2089: }
1.1 deraadt 2090: }
2091:
1.16 markus 2092: /*
2093: * Logs the error plus constructs and sends a disconnect packet, closes the
2094: * connection, and exits. This function never returns. The error message
2095: * should not contain a newline. The length of the formatted message must
2096: * not exceed 1024 bytes.
2097: */
1.2 provos 2098: void
1.201 markus 2099: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 2100: {
1.14 markus 2101: char buf[1024];
2102: va_list args;
2103: static int disconnecting = 0;
1.201 markus 2104: int r;
1.97 deraadt 2105:
1.14 markus 2106: if (disconnecting) /* Guard against recursive invocations. */
2107: fatal("packet_disconnect called recursively.");
2108: disconnecting = 1;
2109:
1.16 markus 2110: /*
2111: * Format the message. Note that the caller must make sure the
2112: * message is of limited size.
2113: */
1.14 markus 2114: va_start(args, fmt);
2115: vsnprintf(buf, sizeof(buf), fmt, args);
2116: va_end(args);
2117:
1.99 markus 2118: /* Display the error locally */
1.106 itojun 2119: logit("Disconnecting: %.100s", buf);
1.99 markus 2120:
1.205 djm 2121: /*
2122: * Send the disconnect message to the other side, and wait
2123: * for it to get sent.
2124: */
2125: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
2126: sshpkt_fatal(ssh, __func__, r);
2127:
2128: if ((r = ssh_packet_write_wait(ssh)) != 0)
2129: sshpkt_fatal(ssh, __func__, r);
1.14 markus 2130:
2131: /* Close the connection. */
1.201 markus 2132: ssh_packet_close(ssh);
1.112 markus 2133: cleanup_exit(255);
1.1 deraadt 2134: }
2135:
1.205 djm 2136: /*
2137: * Checks if there is any buffered output, and tries to write some of
2138: * the output.
2139: */
2140: int
1.201 markus 2141: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 2142: {
1.201 markus 2143: struct session_state *state = ssh->state;
2144: int len = sshbuf_len(state->output);
1.222 markus 2145: int r;
1.97 deraadt 2146:
1.14 markus 2147: if (len > 0) {
1.222 markus 2148: len = write(state->connection_out,
2149: sshbuf_ptr(state->output), len);
1.156 djm 2150: if (len == -1) {
2151: if (errno == EINTR || errno == EAGAIN)
1.205 djm 2152: return 0;
2153: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 2154: }
1.222 markus 2155: if (len == 0)
1.205 djm 2156: return SSH_ERR_CONN_CLOSED;
1.201 markus 2157: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 2158: return r;
1.14 markus 2159: }
1.205 djm 2160: return 0;
1.1 deraadt 2161: }
2162:
1.16 markus 2163: /*
2164: * Calls packet_write_poll repeatedly until all pending output data has been
2165: * written.
2166: */
1.205 djm 2167: int
1.201 markus 2168: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 2169: {
1.56 millert 2170: fd_set *setp;
1.205 djm 2171: int ret, r, ms_remain = 0;
1.154 dtucker 2172: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 2173: struct session_state *state = ssh->state;
1.56 millert 2174:
1.214 deraadt 2175: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 2176: NFDBITS), sizeof(fd_mask));
1.201 markus 2177: if (setp == NULL)
1.205 djm 2178: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 2179: if ((r = ssh_packet_write_poll(ssh)) != 0) {
2180: free(setp);
1.215 djm 2181: return r;
1.216 gsoares 2182: }
1.201 markus 2183: while (ssh_packet_have_data_to_write(ssh)) {
2184: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 2185: NFDBITS) * sizeof(fd_mask));
1.201 markus 2186: FD_SET(state->connection_out, setp);
1.154 dtucker 2187:
1.201 markus 2188: if (state->packet_timeout_ms > 0) {
2189: ms_remain = state->packet_timeout_ms;
1.154 dtucker 2190: timeoutp = &timeout;
2191: }
2192: for (;;) {
1.201 markus 2193: if (state->packet_timeout_ms != -1) {
1.154 dtucker 2194: ms_to_timeval(&timeout, ms_remain);
2195: gettimeofday(&start, NULL);
2196: }
1.201 markus 2197: if ((ret = select(state->connection_out + 1,
1.161 andreas 2198: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 2199: break;
1.161 andreas 2200: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 2201: break;
1.201 markus 2202: if (state->packet_timeout_ms == -1)
1.154 dtucker 2203: continue;
2204: ms_subtract_diff(&start, &ms_remain);
2205: if (ms_remain <= 0) {
2206: ret = 0;
2207: break;
2208: }
2209: }
2210: if (ret == 0) {
1.205 djm 2211: free(setp);
2212: return SSH_ERR_CONN_TIMEOUT;
2213: }
2214: if ((r = ssh_packet_write_poll(ssh)) != 0) {
2215: free(setp);
2216: return r;
1.154 dtucker 2217: }
1.14 markus 2218: }
1.186 djm 2219: free(setp);
1.205 djm 2220: return 0;
1.1 deraadt 2221: }
2222:
2223: /* Returns true if there is buffered data to write to the connection. */
2224:
1.2 provos 2225: int
1.201 markus 2226: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 2227: {
1.201 markus 2228: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 2229: }
2230:
2231: /* Returns true if there is not too much data to write to the connection. */
2232:
1.2 provos 2233: int
1.201 markus 2234: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 2235: {
1.201 markus 2236: if (ssh->state->interactive_mode)
2237: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 2238: else
1.201 markus 2239: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 2240: }
2241:
1.201 markus 2242: void
2243: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 2244: {
1.201 markus 2245: if (!ssh_packet_connection_is_on_socket(ssh))
1.101 markus 2246: return;
1.201 markus 2247: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 2248: case AF_INET:
2249: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 2250: if (setsockopt(ssh->state->connection_in,
1.173 djm 2251: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
2252: error("setsockopt IP_TOS %d: %.100s:",
2253: tos, strerror(errno));
2254: break;
2255: case AF_INET6:
2256: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 2257: if (setsockopt(ssh->state->connection_in,
1.173 djm 2258: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2259: error("setsockopt IPV6_TCLASS %d: %.100s:",
2260: tos, strerror(errno));
2261: break;
2262: }
1.101 markus 2263: }
2264:
1.1 deraadt 2265: /* Informs that the current session is interactive. Sets IP flags for that. */
2266:
1.2 provos 2267: void
1.201 markus 2268: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2269: {
1.201 markus 2270: struct session_state *state = ssh->state;
2271:
2272: if (state->set_interactive_called)
1.43 markus 2273: return;
1.201 markus 2274: state->set_interactive_called = 1;
1.1 deraadt 2275:
1.14 markus 2276: /* Record that we are in interactive mode. */
1.201 markus 2277: state->interactive_mode = interactive;
1.1 deraadt 2278:
1.19 markus 2279: /* Only set socket options if using a socket. */
1.201 markus 2280: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2281: return;
1.201 markus 2282: set_nodelay(state->connection_in);
2283: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2284: qos_bulk);
1.1 deraadt 2285: }
2286:
2287: /* Returns true if the current connection is interactive. */
2288:
1.2 provos 2289: int
1.201 markus 2290: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2291: {
1.201 markus 2292: return ssh->state->interactive_mode;
1.12 markus 2293: }
2294:
1.113 deraadt 2295: int
1.201 markus 2296: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2297: {
1.201 markus 2298: struct session_state *state = ssh->state;
2299:
2300: if (state->set_maxsize_called) {
1.106 itojun 2301: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2302: state->max_packet_size, s);
1.14 markus 2303: return -1;
2304: }
2305: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2306: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2307: return -1;
2308: }
1.201 markus 2309: state->set_maxsize_called = 1;
1.66 markus 2310: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2311: state->max_packet_size = s;
1.14 markus 2312: return s;
1.53 markus 2313: }
2314:
1.161 andreas 2315: int
1.201 markus 2316: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2317: {
1.201 markus 2318: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2319: }
2320:
2321: void
1.201 markus 2322: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2323: {
1.201 markus 2324: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2325: }
2326:
2327: u_int
1.201 markus 2328: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2329: {
1.201 markus 2330: return ssh->state->max_packet_size;
1.71 markus 2331: }
2332:
1.53 markus 2333: /*
2334: * 9.2. Ignored Data Message
1.61 markus 2335: *
1.53 markus 2336: * byte SSH_MSG_IGNORE
2337: * string data
1.61 markus 2338: *
1.53 markus 2339: * All implementations MUST understand (and ignore) this message at any
2340: * time (after receiving the protocol version). No implementation is
2341: * required to send them. This message can be used as an additional
2342: * protection measure against advanced traffic analysis techniques.
2343: */
1.54 markus 2344: void
1.201 markus 2345: ssh_packet_send_ignore(struct ssh *ssh, int nbytes)
1.54 markus 2346: {
1.115 avsm 2347: u_int32_t rnd = 0;
1.201 markus 2348: int r, i;
1.54 markus 2349:
1.201 markus 2350: if ((r = sshpkt_start(ssh, compat20 ?
2351: SSH2_MSG_IGNORE : SSH_MSG_IGNORE)) != 0 ||
2352: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2353: fatal("%s: %s", __func__, ssh_err(r));
1.75 deraadt 2354: for (i = 0; i < nbytes; i++) {
1.53 markus 2355: if (i % 4 == 0)
1.115 avsm 2356: rnd = arc4random();
1.201 markus 2357: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2358: fatal("%s: %s", __func__, ssh_err(r));
1.115 avsm 2359: rnd >>= 8;
1.53 markus 2360: }
1.105 markus 2361: }
2362:
2363: void
1.224 dtucker 2364: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, time_t seconds)
1.105 markus 2365: {
1.224 dtucker 2366: debug3("rekey after %llu bytes, %d seconds", (unsigned long long)bytes,
1.184 dtucker 2367: (int)seconds);
1.201 markus 2368: ssh->state->rekey_limit = bytes;
2369: ssh->state->rekey_interval = seconds;
1.184 dtucker 2370: }
2371:
2372: time_t
1.201 markus 2373: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2374: {
2375: time_t seconds;
2376:
1.201 markus 2377: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2378: monotime();
1.185 dtucker 2379: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2380: }
2381:
2382: void
1.201 markus 2383: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2384: {
1.201 markus 2385: ssh->state->server_side = 1;
1.118 markus 2386: }
2387:
2388: void
1.201 markus 2389: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2390: {
1.201 markus 2391: ssh->state->after_authentication = 1;
1.161 andreas 2392: }
2393:
2394: void *
1.201 markus 2395: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2396: {
1.201 markus 2397: return (void *)ssh->state->input;
1.161 andreas 2398: }
2399:
2400: void *
1.201 markus 2401: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2402: {
1.201 markus 2403: return (void *)ssh->state->output;
1.166 andreas 2404: }
2405:
1.196 markus 2406: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2407: static int
2408: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2409: {
1.239 djm 2410: int r;
1.196 markus 2411:
2412: debug("%s: called", __func__);
2413: /* This was set in net child, but is not visible in user child */
1.201 markus 2414: ssh->state->after_authentication = 1;
2415: ssh->state->rekeying = 0;
1.239 djm 2416: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2417: return r;
1.201 markus 2418: return 0;
2419: }
2420:
2421: /* Packet state (de-)serialization for privsep */
2422:
2423: /* turn kex into a blob for packet state serialization */
2424: static int
2425: kex_to_blob(struct sshbuf *m, struct kex *kex)
2426: {
2427: int r;
2428:
2429: if ((r = sshbuf_put_string(m, kex->session_id,
2430: kex->session_id_len)) != 0 ||
2431: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2432: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2433: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2434: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2435: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2436: (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2437: (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2438: (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2439: return r;
2440: return 0;
2441: }
2442:
2443: /* turn key exchange results into a blob for packet state serialization */
2444: static int
2445: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2446: {
2447: struct sshbuf *b;
2448: struct sshcipher_ctx *cc;
2449: struct sshcomp *comp;
2450: struct sshenc *enc;
2451: struct sshmac *mac;
2452: struct newkeys *newkey;
2453: int r;
2454:
2455: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2456: return SSH_ERR_INTERNAL_ERROR;
2457: enc = &newkey->enc;
2458: mac = &newkey->mac;
2459: comp = &newkey->comp;
1.235 djm 2460: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2461: ssh->state->receive_context;
1.201 markus 2462: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2463: return r;
2464: if ((b = sshbuf_new()) == NULL)
2465: return SSH_ERR_ALLOC_FAIL;
2466: /* The cipher struct is constant and shared, you export pointer */
2467: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2468: (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2469: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2470: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2471: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2472: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2473: goto out;
2474: if (cipher_authlen(enc->cipher) == 0) {
2475: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2476: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2477: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2478: goto out;
2479: }
2480: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2481: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2482: goto out;
2483: r = sshbuf_put_stringb(m, b);
2484: out:
1.221 mmcc 2485: sshbuf_free(b);
1.201 markus 2486: return r;
2487: }
2488:
2489: /* serialize packet state into a blob */
2490: int
2491: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2492: {
2493: struct session_state *state = ssh->state;
2494: u_char *p;
2495: size_t slen, rlen;
2496: int r, ssh1cipher;
2497:
2498: if (!compat20) {
1.235 djm 2499: ssh1cipher = cipher_ctx_get_number(state->receive_context);
2500: slen = cipher_get_keyiv_len(state->send_context);
2501: rlen = cipher_get_keyiv_len(state->receive_context);
1.201 markus 2502: if ((r = sshbuf_put_u32(m, state->remote_protocol_flags)) != 0 ||
2503: (r = sshbuf_put_u32(m, ssh1cipher)) != 0 ||
2504: (r = sshbuf_put_string(m, state->ssh1_key, state->ssh1_keylen)) != 0 ||
2505: (r = sshbuf_put_u32(m, slen)) != 0 ||
2506: (r = sshbuf_reserve(m, slen, &p)) != 0 ||
1.235 djm 2507: (r = cipher_get_keyiv(state->send_context, p, slen)) != 0 ||
1.201 markus 2508: (r = sshbuf_put_u32(m, rlen)) != 0 ||
2509: (r = sshbuf_reserve(m, rlen, &p)) != 0 ||
1.235 djm 2510: (r = cipher_get_keyiv(state->receive_context, p, rlen)) != 0)
1.201 markus 2511: return r;
2512: } else {
2513: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2514: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2515: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
1.224 dtucker 2516: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
1.208 markus 2517: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
1.201 markus 2518: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2519: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2520: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2521: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2522: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2523: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2524: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
2525: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0)
2526: return r;
2527: }
2528:
1.235 djm 2529: slen = cipher_get_keycontext(state->send_context, NULL);
2530: rlen = cipher_get_keycontext(state->receive_context, NULL);
1.201 markus 2531: if ((r = sshbuf_put_u32(m, slen)) != 0 ||
2532: (r = sshbuf_reserve(m, slen, &p)) != 0)
2533: return r;
1.235 djm 2534: if (cipher_get_keycontext(state->send_context, p) != (int)slen)
1.201 markus 2535: return SSH_ERR_INTERNAL_ERROR;
2536: if ((r = sshbuf_put_u32(m, rlen)) != 0 ||
2537: (r = sshbuf_reserve(m, rlen, &p)) != 0)
2538: return r;
1.235 djm 2539: if (cipher_get_keycontext(state->receive_context, p) != (int)rlen)
1.201 markus 2540: return SSH_ERR_INTERNAL_ERROR;
1.239 djm 2541: if ((r = sshbuf_put_stringb(m, state->input)) != 0 ||
1.201 markus 2542: (r = sshbuf_put_stringb(m, state->output)) != 0)
2543: return r;
2544:
2545: return 0;
2546: }
2547:
2548: /* restore key exchange results from blob for packet state de-serialization */
2549: static int
2550: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2551: {
2552: struct sshbuf *b = NULL;
2553: struct sshcomp *comp;
2554: struct sshenc *enc;
2555: struct sshmac *mac;
2556: struct newkeys *newkey = NULL;
2557: size_t keylen, ivlen, maclen;
2558: int r;
2559:
2560: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2561: r = SSH_ERR_ALLOC_FAIL;
2562: goto out;
2563: }
2564: if ((r = sshbuf_froms(m, &b)) != 0)
2565: goto out;
2566: #ifdef DEBUG_PK
2567: sshbuf_dump(b, stderr);
2568: #endif
2569: enc = &newkey->enc;
2570: mac = &newkey->mac;
2571: comp = &newkey->comp;
2572:
2573: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2574: (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2575: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2576: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2577: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2578: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2579: goto out;
2580: if (cipher_authlen(enc->cipher) == 0) {
2581: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2582: goto out;
2583: if ((r = mac_setup(mac, mac->name)) != 0)
2584: goto out;
2585: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2586: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2587: goto out;
2588: if (maclen > mac->key_len) {
2589: r = SSH_ERR_INVALID_FORMAT;
2590: goto out;
2591: }
2592: mac->key_len = maclen;
2593: }
2594: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2595: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2596: goto out;
2597: if (enc->name == NULL ||
2598: cipher_by_name(enc->name) != enc->cipher) {
2599: r = SSH_ERR_INVALID_FORMAT;
2600: goto out;
2601: }
2602: if (sshbuf_len(b) != 0) {
2603: r = SSH_ERR_INVALID_FORMAT;
2604: goto out;
2605: }
2606: enc->key_len = keylen;
2607: enc->iv_len = ivlen;
2608: ssh->kex->newkeys[mode] = newkey;
2609: newkey = NULL;
2610: r = 0;
2611: out:
1.219 mmcc 2612: free(newkey);
1.221 mmcc 2613: sshbuf_free(b);
1.201 markus 2614: return r;
2615: }
2616:
2617: /* restore kex from blob for packet state de-serialization */
2618: static int
2619: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2620: {
2621: struct kex *kex;
2622: int r;
2623:
2624: if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2625: (kex->my = sshbuf_new()) == NULL ||
2626: (kex->peer = sshbuf_new()) == NULL) {
2627: r = SSH_ERR_ALLOC_FAIL;
2628: goto out;
2629: }
2630: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2631: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2632: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2633: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2634: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2635: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2636: (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2637: (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2638: (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2639: goto out;
2640: kex->server = 1;
2641: kex->done = 1;
2642: r = 0;
2643: out:
2644: if (r != 0 || kexp == NULL) {
2645: if (kex != NULL) {
1.221 mmcc 2646: sshbuf_free(kex->my);
2647: sshbuf_free(kex->peer);
1.201 markus 2648: free(kex);
2649: }
2650: if (kexp != NULL)
2651: *kexp = NULL;
2652: } else {
2653: *kexp = kex;
2654: }
2655: return r;
2656: }
2657:
2658: /*
2659: * Restore packet state from content of blob 'm' (de-serialization).
2660: * Note that 'm' will be partially consumed on parsing or any other errors.
2661: */
2662: int
2663: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2664: {
2665: struct session_state *state = ssh->state;
2666: const u_char *ssh1key, *ivin, *ivout, *keyin, *keyout, *input, *output;
2667: size_t ssh1keylen, rlen, slen, ilen, olen;
2668: int r;
2669: u_int ssh1cipher = 0;
2670:
2671: if (!compat20) {
2672: if ((r = sshbuf_get_u32(m, &state->remote_protocol_flags)) != 0 ||
2673: (r = sshbuf_get_u32(m, &ssh1cipher)) != 0 ||
2674: (r = sshbuf_get_string_direct(m, &ssh1key, &ssh1keylen)) != 0 ||
2675: (r = sshbuf_get_string_direct(m, &ivout, &slen)) != 0 ||
2676: (r = sshbuf_get_string_direct(m, &ivin, &rlen)) != 0)
2677: return r;
2678: if (ssh1cipher > INT_MAX)
2679: return SSH_ERR_KEY_UNKNOWN_CIPHER;
2680: ssh_packet_set_encryption_key(ssh, ssh1key, ssh1keylen,
2681: (int)ssh1cipher);
1.235 djm 2682: if (cipher_get_keyiv_len(state->send_context) != (int)slen ||
2683: cipher_get_keyiv_len(state->receive_context) != (int)rlen)
1.201 markus 2684: return SSH_ERR_INVALID_FORMAT;
1.235 djm 2685: if ((r = cipher_set_keyiv(state->send_context, ivout)) != 0 ||
2686: (r = cipher_set_keyiv(state->receive_context, ivin)) != 0)
1.201 markus 2687: return r;
2688: } else {
2689: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2690: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2691: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
1.224 dtucker 2692: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
1.208 markus 2693: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
1.201 markus 2694: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2695: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2696: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2697: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2698: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2699: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2700: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2701: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2702: return r;
1.208 markus 2703: /*
2704: * We set the time here so that in post-auth privsep slave we
2705: * count from the completion of the authentication.
2706: */
2707: state->rekey_time = monotime();
1.201 markus 2708: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2709: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2710: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2711: return r;
2712: }
2713: if ((r = sshbuf_get_string_direct(m, &keyout, &slen)) != 0 ||
2714: (r = sshbuf_get_string_direct(m, &keyin, &rlen)) != 0)
2715: return r;
1.235 djm 2716: if (cipher_get_keycontext(state->send_context, NULL) != (int)slen ||
2717: cipher_get_keycontext(state->receive_context, NULL) != (int)rlen)
1.201 markus 2718: return SSH_ERR_INVALID_FORMAT;
1.235 djm 2719: cipher_set_keycontext(state->send_context, keyout);
2720: cipher_set_keycontext(state->receive_context, keyin);
1.201 markus 2721:
1.239 djm 2722: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2723: return r;
2724:
2725: sshbuf_reset(state->input);
2726: sshbuf_reset(state->output);
2727: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2728: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2729: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2730: (r = sshbuf_put(state->output, output, olen)) != 0)
2731: return r;
2732:
2733: if (sshbuf_len(m))
2734: return SSH_ERR_INVALID_FORMAT;
2735: debug3("%s: done", __func__);
2736: return 0;
2737: }
2738:
2739: /* NEW API */
2740:
2741: /* put data to the outgoing packet */
2742:
2743: int
2744: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2745: {
2746: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2747: }
2748:
2749: int
2750: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2751: {
2752: return sshbuf_putb(ssh->state->outgoing_packet, b);
2753: }
2754:
2755: int
2756: sshpkt_put_u8(struct ssh *ssh, u_char val)
2757: {
2758: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2759: }
2760:
2761: int
2762: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2763: {
2764: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2765: }
2766:
2767: int
2768: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2769: {
2770: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2771: }
2772:
2773: int
2774: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2775: {
2776: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2777: }
2778:
2779: int
2780: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2781: {
2782: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2783: }
2784:
2785: int
2786: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2787: {
2788: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2789: }
2790:
1.211 djm 2791: #ifdef WITH_OPENSSL
1.201 markus 2792: int
2793: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2794: {
2795: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2796: }
2797:
1.211 djm 2798: #ifdef WITH_SSH1
1.201 markus 2799: int
2800: sshpkt_put_bignum1(struct ssh *ssh, const BIGNUM *v)
2801: {
2802: return sshbuf_put_bignum1(ssh->state->outgoing_packet, v);
2803: }
1.211 djm 2804: #endif /* WITH_SSH1 */
1.201 markus 2805:
2806: int
2807: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2808: {
2809: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2810: }
1.211 djm 2811: #endif /* WITH_OPENSSL */
1.201 markus 2812:
2813: /* fetch data from the incoming packet */
2814:
2815: int
2816: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2817: {
2818: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2819: }
2820:
2821: int
2822: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2823: {
2824: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2825: }
2826:
2827: int
2828: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2829: {
2830: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2831: }
2832:
2833: int
2834: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2835: {
2836: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2837: }
2838:
2839: int
2840: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2841: {
2842: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2843: }
2844:
2845: int
2846: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2847: {
2848: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2849: }
2850:
2851: int
2852: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2853: {
2854: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2855: }
2856:
1.211 djm 2857: #ifdef WITH_OPENSSL
1.201 markus 2858: int
2859: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2860: {
2861: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2862: }
2863:
1.211 djm 2864: #ifdef WITH_SSH1
1.201 markus 2865: int
2866: sshpkt_get_bignum1(struct ssh *ssh, BIGNUM *v)
2867: {
2868: return sshbuf_get_bignum1(ssh->state->incoming_packet, v);
2869: }
1.211 djm 2870: #endif /* WITH_SSH1 */
1.201 markus 2871:
2872: int
2873: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2874: {
2875: return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2876: }
1.211 djm 2877: #endif /* WITH_OPENSSL */
1.201 markus 2878:
2879: int
2880: sshpkt_get_end(struct ssh *ssh)
2881: {
2882: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2883: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2884: return 0;
2885: }
2886:
2887: const u_char *
2888: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2889: {
2890: if (lenp != NULL)
2891: *lenp = sshbuf_len(ssh->state->incoming_packet);
2892: return sshbuf_ptr(ssh->state->incoming_packet);
2893: }
2894:
2895: /* start a new packet */
2896:
2897: int
2898: sshpkt_start(struct ssh *ssh, u_char type)
2899: {
2900: u_char buf[9];
2901: int len;
2902:
2903: DBG(debug("packet_start[%d]", type));
2904: len = compat20 ? 6 : 9;
2905: memset(buf, 0, len - 1);
2906: buf[len - 1] = type;
2907: sshbuf_reset(ssh->state->outgoing_packet);
2908: return sshbuf_put(ssh->state->outgoing_packet, buf, len);
2909: }
2910:
1.242 ! markus 2911: static int
! 2912: ssh_packet_send_mux(struct ssh *ssh)
! 2913: {
! 2914: struct session_state *state = ssh->state;
! 2915: u_char type, *cp;
! 2916: size_t len;
! 2917: int r;
! 2918:
! 2919: if (ssh->kex)
! 2920: return SSH_ERR_INTERNAL_ERROR;
! 2921: len = sshbuf_len(state->outgoing_packet);
! 2922: if (len < 6)
! 2923: return SSH_ERR_INTERNAL_ERROR;
! 2924: cp = sshbuf_mutable_ptr(state->outgoing_packet);
! 2925: type = cp[5];
! 2926: if (ssh_packet_log_type(type))
! 2927: debug3("%s: type %u", __func__, type);
! 2928: /* drop everything, but the connection protocol */
! 2929: if (type >= SSH2_MSG_CONNECTION_MIN &&
! 2930: type <= SSH2_MSG_CONNECTION_MAX) {
! 2931: POKE_U32(cp, len - 4);
! 2932: if ((r = sshbuf_putb(state->output,
! 2933: state->outgoing_packet)) != 0)
! 2934: return r;
! 2935: /* sshbuf_dump(state->output, stderr); */
! 2936: }
! 2937: sshbuf_reset(state->outgoing_packet);
! 2938: return 0;
! 2939: }
! 2940:
1.201 markus 2941: /* send it */
2942:
2943: int
2944: sshpkt_send(struct ssh *ssh)
2945: {
1.242 ! markus 2946: if (ssh->state && ssh->state->mux)
! 2947: return ssh_packet_send_mux(ssh);
1.201 markus 2948: if (compat20)
2949: return ssh_packet_send2(ssh);
2950: else
2951: return ssh_packet_send1(ssh);
2952: }
2953:
2954: int
2955: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2956: {
2957: char buf[1024];
2958: va_list args;
2959: int r;
2960:
2961: va_start(args, fmt);
2962: vsnprintf(buf, sizeof(buf), fmt, args);
2963: va_end(args);
2964:
2965: if (compat20) {
2966: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2967: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2968: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2969: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2970: (r = sshpkt_send(ssh)) != 0)
2971: return r;
2972: } else {
2973: if ((r = sshpkt_start(ssh, SSH_MSG_DISCONNECT)) != 0 ||
2974: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2975: (r = sshpkt_send(ssh)) != 0)
2976: return r;
1.166 andreas 2977: }
1.201 markus 2978: return 0;
2979: }
2980:
2981: /* roundup current message to pad bytes */
2982: int
2983: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2984: {
2985: ssh->state->extra_pad = pad;
2986: return 0;
1.1 deraadt 2987: }
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