Annotation of src/usr.bin/ssh/packet.c, Revision 1.294
1.294 ! semarie 1: /* $OpenBSD: packet.c,v 1.293 2020/06/24 15:12:09 markus Exp $ */
1.1 deraadt 2: /*
1.15 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.35 deraadt 6: * This file contains code implementing the packet protocol and communication
7: * with the other side. This same code is used both on client and server side.
1.29 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
1.29 markus 14: *
1.25 markus 15: *
16: * SSH2 packet format added by Markus Friedl.
1.69 markus 17: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.25 markus 18: *
1.35 deraadt 19: * Redistribution and use in source and binary forms, with or without
20: * modification, are permitted provided that the following conditions
21: * are met:
22: * 1. Redistributions of source code must retain the above copyright
23: * notice, this list of conditions and the following disclaimer.
24: * 2. Redistributions in binary form must reproduce the above copyright
25: * notice, this list of conditions and the following disclaimer in the
26: * documentation and/or other materials provided with the distribution.
27: *
28: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15 deraadt 38: */
1.1 deraadt 39:
1.142 deraadt 40: #include <sys/types.h>
1.105 markus 41: #include <sys/queue.h>
1.132 stevesk 42: #include <sys/socket.h>
1.138 stevesk 43: #include <sys/time.h>
1.132 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>
1.278 djm 55: #include <poll.h>
1.142 deraadt 56: #include <signal.h>
1.184 dtucker 57: #include <time.h>
1.1 deraadt 58:
1.288 dtucker 59: #ifdef WITH_ZLIB
1.201 markus 60: #include <zlib.h>
1.288 dtucker 61: #endif
1.201 markus 62:
1.1 deraadt 63: #include "xmalloc.h"
1.25 markus 64: #include "compat.h"
65: #include "ssh2.h"
1.37 markus 66: #include "cipher.h"
1.201 markus 67: #include "sshkey.h"
1.25 markus 68: #include "kex.h"
1.200 markus 69: #include "digest.h"
1.50 markus 70: #include "mac.h"
1.46 markus 71: #include "log.h"
72: #include "canohost.h"
1.87 stevesk 73: #include "misc.h"
1.198 millert 74: #include "channels.h"
1.95 markus 75: #include "ssh.h"
1.201 markus 76: #include "packet.h"
1.197 djm 77: #include "ssherr.h"
1.201 markus 78: #include "sshbuf.h"
1.25 markus 79:
80: #ifdef PACKET_DEBUG
81: #define DBG(x) x
82: #else
83: #define DBG(x)
84: #endif
85:
1.159 markus 86: #define PACKET_MAX_SIZE (256 * 1024)
87:
1.161 andreas 88: struct packet_state {
89: u_int32_t seqnr;
90: u_int32_t packets;
91: u_int64_t blocks;
92: u_int64_t bytes;
93: };
94:
95: struct packet {
96: TAILQ_ENTRY(packet) next;
97: u_char type;
1.201 markus 98: struct sshbuf *payload;
1.161 andreas 99: };
100:
101: struct session_state {
102: /*
103: * This variable contains the file descriptors used for
104: * communicating with the other side. connection_in is used for
105: * reading; connection_out for writing. These can be the same
106: * descriptor, in which case it is assumed to be a socket.
107: */
108: int connection_in;
109: int connection_out;
110:
111: /* Protocol flags for the remote side. */
112: u_int remote_protocol_flags;
1.1 deraadt 113:
1.161 andreas 114: /* Encryption context for receiving data. Only used for decryption. */
1.235 djm 115: struct sshcipher_ctx *receive_context;
1.1 deraadt 116:
1.161 andreas 117: /* Encryption context for sending data. Only used for encryption. */
1.235 djm 118: struct sshcipher_ctx *send_context;
1.14 markus 119:
1.161 andreas 120: /* Buffer for raw input data from the socket. */
1.201 markus 121: struct sshbuf *input;
1.1 deraadt 122:
1.161 andreas 123: /* Buffer for raw output data going to the socket. */
1.201 markus 124: struct sshbuf *output;
1.1 deraadt 125:
1.161 andreas 126: /* Buffer for the partial outgoing packet being constructed. */
1.201 markus 127: struct sshbuf *outgoing_packet;
1.1 deraadt 128:
1.161 andreas 129: /* Buffer for the incoming packet currently being processed. */
1.201 markus 130: struct sshbuf *incoming_packet;
1.1 deraadt 131:
1.161 andreas 132: /* Scratch buffer for packet compression/decompression. */
1.201 markus 133: struct sshbuf *compression_buffer;
134:
1.288 dtucker 135: #ifdef WITH_ZLIB
1.201 markus 136: /* Incoming/outgoing compression dictionaries */
137: z_stream compression_in_stream;
138: z_stream compression_out_stream;
1.288 dtucker 139: #endif
1.201 markus 140: int compression_in_started;
141: int compression_out_started;
142: int compression_in_failures;
143: int compression_out_failures;
1.1 deraadt 144:
1.161 andreas 145: /* default maximum packet size */
146: u_int max_packet_size;
1.1 deraadt 147:
1.161 andreas 148: /* Flag indicating whether this module has been initialized. */
149: int initialized;
1.12 markus 150:
1.161 andreas 151: /* Set to true if the connection is interactive. */
152: int interactive_mode;
1.1 deraadt 153:
1.161 andreas 154: /* Set to true if we are the server side. */
155: int server_side;
1.1 deraadt 156:
1.161 andreas 157: /* Set to true if we are authenticated. */
158: int after_authentication;
1.118 markus 159:
1.161 andreas 160: int keep_alive_timeouts;
1.118 markus 161:
1.161 andreas 162: /* The maximum time that we will wait to send or receive a packet */
163: int packet_timeout_ms;
1.151 dtucker 164:
1.161 andreas 165: /* Session key information for Encryption and MAC */
1.201 markus 166: struct newkeys *newkeys[MODE_MAX];
1.161 andreas 167: struct packet_state p_read, p_send;
1.154 dtucker 168:
1.184 dtucker 169: /* Volume-based rekeying */
1.224 dtucker 170: u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
1.105 markus 171:
1.184 dtucker 172: /* Time-based rekeying */
1.208 markus 173: u_int32_t rekey_interval; /* how often in seconds */
1.184 dtucker 174: time_t rekey_time; /* time of last rekeying */
175:
1.161 andreas 176: /* roundup current message to extra_pad bytes */
177: u_char extra_pad;
1.95 markus 178:
1.161 andreas 179: /* XXX discard incoming data after MAC error */
180: u_int packet_discard;
1.234 markus 181: size_t packet_discard_mac_already;
1.201 markus 182: struct sshmac *packet_discard_mac;
1.71 markus 183:
1.161 andreas 184: /* Used in packet_read_poll2() */
185: u_int packlen;
1.159 markus 186:
1.165 andreas 187: /* Used in packet_send2 */
188: int rekeying;
189:
1.242 markus 190: /* Used in ssh_packet_send_mux() */
191: int mux;
192:
1.165 andreas 193: /* Used in packet_set_interactive */
194: int set_interactive_called;
195:
196: /* Used in packet_set_maxsize */
197: int set_maxsize_called;
198:
1.201 markus 199: /* One-off warning about weak ciphers */
200: int cipher_warning_done;
201:
1.243 djm 202: /* Hook for fuzzing inbound packets */
203: ssh_packet_hook_fn *hook_in;
204: void *hook_in_ctx;
205:
1.161 andreas 206: TAILQ_HEAD(, packet) outgoing;
1.105 markus 207: };
1.161 andreas 208:
1.201 markus 209: struct ssh *
210: ssh_alloc_session_state(void)
1.161 andreas 211: {
1.201 markus 212: struct ssh *ssh = NULL;
213: struct session_state *state = NULL;
1.161 andreas 214:
1.201 markus 215: if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
216: (state = calloc(1, sizeof(*state))) == NULL ||
1.278 djm 217: (ssh->kex = kex_new()) == NULL ||
1.201 markus 218: (state->input = sshbuf_new()) == NULL ||
219: (state->output = sshbuf_new()) == NULL ||
220: (state->outgoing_packet = sshbuf_new()) == NULL ||
221: (state->incoming_packet = sshbuf_new()) == NULL)
222: goto fail;
223: TAILQ_INIT(&state->outgoing);
1.202 markus 224: TAILQ_INIT(&ssh->private_keys);
225: TAILQ_INIT(&ssh->public_keys);
1.201 markus 226: state->connection_in = -1;
227: state->connection_out = -1;
228: state->max_packet_size = 32768;
229: state->packet_timeout_ms = -1;
230: state->p_send.packets = state->p_read.packets = 0;
231: state->initialized = 1;
232: /*
233: * ssh_packet_send2() needs to queue packets until
234: * we've done the initial key exchange.
235: */
236: state->rekeying = 1;
237: ssh->state = state;
238: return ssh;
239: fail:
1.278 djm 240: if (ssh) {
241: kex_free(ssh->kex);
242: free(ssh);
243: }
1.201 markus 244: if (state) {
245: sshbuf_free(state->input);
246: sshbuf_free(state->output);
247: sshbuf_free(state->incoming_packet);
248: sshbuf_free(state->outgoing_packet);
249: free(state);
250: }
251: return NULL;
1.161 andreas 252: }
1.105 markus 253:
1.243 djm 254: void
255: ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
256: {
257: ssh->state->hook_in = hook;
258: ssh->state->hook_in_ctx = ctx;
259: }
260:
1.228 djm 261: /* Returns nonzero if rekeying is in progress */
262: int
263: ssh_packet_is_rekeying(struct ssh *ssh)
264: {
1.292 markus 265: return ssh->state->rekeying ||
266: (ssh->kex != NULL && ssh->kex->done == 0);
1.228 djm 267: }
268:
1.16 markus 269: /*
1.253 naddy 270: * Sets the descriptors used for communication.
1.16 markus 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) {
1.285 dtucker 286: error("%s: could not allocate state", __func__);
1.205 djm 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;
1.207 djm 301: /*
302: * Cache the IP address of the remote connection for use in error
303: * messages that might be generated after the connection has closed.
304: */
305: (void)ssh_remote_ipaddr(ssh);
1.201 markus 306: return ssh;
1.1 deraadt 307: }
308:
1.154 dtucker 309: void
1.201 markus 310: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 311: {
1.201 markus 312: struct session_state *state = ssh->state;
313:
1.174 djm 314: if (timeout <= 0 || count <= 0) {
1.201 markus 315: state->packet_timeout_ms = -1;
1.154 dtucker 316: return;
317: }
318: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 319: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 320: else
1.201 markus 321: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 322: }
323:
1.242 markus 324: void
325: ssh_packet_set_mux(struct ssh *ssh)
326: {
327: ssh->state->mux = 1;
328: ssh->state->rekeying = 0;
1.292 markus 329: kex_free(ssh->kex);
330: ssh->kex = NULL;
1.242 markus 331: }
332:
333: int
334: ssh_packet_get_mux(struct ssh *ssh)
335: {
336: return ssh->state->mux;
337: }
338:
1.201 markus 339: int
1.245 djm 340: ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
341: {
342: va_list args;
343: int r;
344:
345: free(ssh->log_preamble);
346: if (fmt == NULL)
347: ssh->log_preamble = NULL;
348: else {
349: va_start(args, fmt);
350: r = vasprintf(&ssh->log_preamble, fmt, args);
351: va_end(args);
352: if (r < 0 || ssh->log_preamble == NULL)
353: return SSH_ERR_ALLOC_FAIL;
354: }
355: return 0;
356: }
357:
358: int
1.201 markus 359: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 360: {
1.201 markus 361: struct session_state *state = ssh->state;
362: int r;
363:
364: if (state->packet_discard_mac) {
1.159 markus 365: char buf[1024];
1.234 markus 366: size_t dlen = PACKET_MAX_SIZE;
1.201 markus 367:
1.234 markus 368: if (dlen > state->packet_discard_mac_already)
369: dlen -= state->packet_discard_mac_already;
1.159 markus 370: memset(buf, 'a', sizeof(buf));
1.234 markus 371: while (sshbuf_len(state->incoming_packet) < dlen)
1.201 markus 372: if ((r = sshbuf_put(state->incoming_packet, buf,
373: sizeof(buf))) != 0)
374: return r;
375: (void) mac_compute(state->packet_discard_mac,
376: state->p_read.seqnr,
1.234 markus 377: sshbuf_ptr(state->incoming_packet), dlen,
1.201 markus 378: NULL, 0);
1.159 markus 379: }
1.220 djm 380: logit("Finished discarding for %.200s port %d",
381: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 382: return SSH_ERR_MAC_INVALID;
1.159 markus 383: }
384:
1.201 markus 385: static int
386: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
1.234 markus 387: struct sshmac *mac, size_t mac_already, u_int discard)
1.159 markus 388: {
1.201 markus 389: struct session_state *state = ssh->state;
390: int r;
391:
392: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
393: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
394: return r;
395: return SSH_ERR_MAC_INVALID;
396: }
1.234 markus 397: /*
398: * Record number of bytes over which the mac has already
399: * been computed in order to minimize timing attacks.
400: */
401: if (mac && mac->enabled) {
1.201 markus 402: state->packet_discard_mac = mac;
1.234 markus 403: state->packet_discard_mac_already = mac_already;
404: }
405: if (sshbuf_len(state->input) >= discard)
406: return ssh_packet_stop_discard(ssh);
1.201 markus 407: state->packet_discard = discard - sshbuf_len(state->input);
408: return 0;
1.159 markus 409: }
410:
1.19 markus 411: /* Returns 1 if remote host is connected via socket, 0 if not. */
412:
413: int
1.201 markus 414: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 415: {
1.271 djm 416: struct session_state *state;
1.19 markus 417: struct sockaddr_storage from, to;
418: socklen_t fromlen, tolen;
419:
1.271 djm 420: if (ssh == NULL || ssh->state == NULL)
421: return 0;
422:
423: state = ssh->state;
1.230 djm 424: if (state->connection_in == -1 || state->connection_out == -1)
425: return 0;
1.19 markus 426: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 427: if (state->connection_in == state->connection_out)
1.19 markus 428: return 1;
429: fromlen = sizeof(from);
430: memset(&from, 0, sizeof(from));
1.201 markus 431: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.286 deraadt 432: &fromlen) == -1)
1.19 markus 433: return 0;
434: tolen = sizeof(to);
435: memset(&to, 0, sizeof(to));
1.201 markus 436: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.286 deraadt 437: &tolen) == -1)
1.19 markus 438: return 0;
439: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
440: return 0;
441: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
442: return 0;
443: return 1;
444: }
445:
1.91 markus 446: void
1.201 markus 447: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 448: {
1.201 markus 449: if (ibytes)
450: *ibytes = ssh->state->p_read.bytes;
451: if (obytes)
452: *obytes = ssh->state->p_send.bytes;
1.91 markus 453: }
1.125 deraadt 454:
1.91 markus 455: int
1.201 markus 456: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 457: {
458: struct sockaddr_storage to;
1.21 deraadt 459: socklen_t tolen = sizeof(to);
1.19 markus 460:
461: memset(&to, 0, sizeof(to));
1.201 markus 462: if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
1.286 deraadt 463: &tolen) == -1)
1.19 markus 464: return 0;
1.173 djm 465: return to.ss_family;
1.19 markus 466: }
467:
1.1 deraadt 468: /* Sets the connection into non-blocking mode. */
469:
1.2 provos 470: void
1.201 markus 471: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 472: {
1.14 markus 473: /* Set the socket into non-blocking mode. */
1.201 markus 474: set_nonblock(ssh->state->connection_in);
1.14 markus 475:
1.201 markus 476: if (ssh->state->connection_out != ssh->state->connection_in)
477: set_nonblock(ssh->state->connection_out);
1.1 deraadt 478: }
479:
480: /* Returns the socket used for reading. */
481:
1.2 provos 482: int
1.201 markus 483: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 484: {
1.201 markus 485: return ssh->state->connection_in;
1.1 deraadt 486: }
487:
488: /* Returns the descriptor used for writing. */
489:
1.2 provos 490: int
1.201 markus 491: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 492: {
1.201 markus 493: return ssh->state->connection_out;
494: }
495:
496: /*
497: * Returns the IP-address of the remote host as a string. The returned
498: * string must not be freed.
499: */
500:
501: const char *
502: ssh_remote_ipaddr(struct ssh *ssh)
503: {
1.271 djm 504: int sock;
1.220 djm 505:
1.201 markus 506: /* Check whether we have cached the ipaddr. */
1.220 djm 507: if (ssh->remote_ipaddr == NULL) {
508: if (ssh_packet_connection_is_on_socket(ssh)) {
1.271 djm 509: sock = ssh->state->connection_in;
1.220 djm 510: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 djm 511: ssh->remote_port = get_peer_port(sock);
512: ssh->local_ipaddr = get_local_ipaddr(sock);
513: ssh->local_port = get_local_port(sock);
1.220 djm 514: } else {
1.287 tobhe 515: ssh->remote_ipaddr = xstrdup("UNKNOWN");
1.230 djm 516: ssh->remote_port = 65535;
1.287 tobhe 517: ssh->local_ipaddr = xstrdup("UNKNOWN");
1.230 djm 518: ssh->local_port = 65535;
1.220 djm 519: }
520: }
1.201 markus 521: return ssh->remote_ipaddr;
1.1 deraadt 522: }
523:
1.220 djm 524: /* Returns the port number of the remote host. */
525:
526: int
527: ssh_remote_port(struct ssh *ssh)
528: {
529: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
530: return ssh->remote_port;
1.230 djm 531: }
532:
533: /*
534: * Returns the IP-address of the local host as a string. The returned
535: * string must not be freed.
536: */
537:
538: const char *
539: ssh_local_ipaddr(struct ssh *ssh)
540: {
541: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
542: return ssh->local_ipaddr;
543: }
544:
545: /* Returns the port number of the local host. */
546:
547: int
548: ssh_local_port(struct ssh *ssh)
549: {
550: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
551: return ssh->local_port;
1.266 djm 552: }
553:
554: /* Returns the routing domain of the input socket, or NULL if unavailable */
555: const char *
556: ssh_packet_rdomain_in(struct ssh *ssh)
557: {
558: if (ssh->rdomain_in != NULL)
559: return ssh->rdomain_in;
560: if (!ssh_packet_connection_is_on_socket(ssh))
561: return NULL;
562: ssh->rdomain_in = get_rdomain(ssh->state->connection_in);
563: return ssh->rdomain_in;
1.220 djm 564: }
565:
1.1 deraadt 566: /* Closes the connection and clears and frees internal data structures. */
567:
1.257 markus 568: static void
569: ssh_packet_close_internal(struct ssh *ssh, int do_close)
1.1 deraadt 570: {
1.201 markus 571: struct session_state *state = ssh->state;
572: u_int mode;
573:
574: if (!state->initialized)
1.14 markus 575: return;
1.201 markus 576: state->initialized = 0;
1.257 markus 577: if (do_close) {
578: if (state->connection_in == state->connection_out) {
579: close(state->connection_out);
580: } else {
581: close(state->connection_in);
582: close(state->connection_out);
583: }
1.14 markus 584: }
1.201 markus 585: sshbuf_free(state->input);
586: sshbuf_free(state->output);
587: sshbuf_free(state->outgoing_packet);
588: sshbuf_free(state->incoming_packet);
1.257 markus 589: for (mode = 0; mode < MODE_MAX; mode++) {
590: kex_free_newkeys(state->newkeys[mode]); /* current keys */
591: state->newkeys[mode] = NULL;
592: ssh_clear_newkeys(ssh, mode); /* next keys */
593: }
1.288 dtucker 594: #ifdef WITH_ZLIB
1.289 dtucker 595: /* compression state is in shared mem, so we can only release it once */
1.257 markus 596: if (do_close && state->compression_buffer) {
1.201 markus 597: sshbuf_free(state->compression_buffer);
598: if (state->compression_out_started) {
599: z_streamp stream = &state->compression_out_stream;
600: debug("compress outgoing: "
601: "raw data %llu, compressed %llu, factor %.2f",
602: (unsigned long long)stream->total_in,
603: (unsigned long long)stream->total_out,
604: stream->total_in == 0 ? 0.0 :
605: (double) stream->total_out / stream->total_in);
606: if (state->compression_out_failures == 0)
607: deflateEnd(stream);
608: }
609: if (state->compression_in_started) {
1.260 dtucker 610: z_streamp stream = &state->compression_in_stream;
1.201 markus 611: debug("compress incoming: "
612: "raw data %llu, compressed %llu, factor %.2f",
613: (unsigned long long)stream->total_out,
614: (unsigned long long)stream->total_in,
615: stream->total_out == 0 ? 0.0 :
616: (double) stream->total_in / stream->total_out);
617: if (state->compression_in_failures == 0)
618: inflateEnd(stream);
619: }
1.14 markus 620: }
1.288 dtucker 621: #endif /* WITH_ZLIB */
1.235 djm 622: cipher_free(state->send_context);
623: cipher_free(state->receive_context);
624: state->send_context = state->receive_context = NULL;
1.257 markus 625: if (do_close) {
1.277 djm 626: free(ssh->local_ipaddr);
627: ssh->local_ipaddr = NULL;
1.257 markus 628: free(ssh->remote_ipaddr);
629: ssh->remote_ipaddr = NULL;
630: free(ssh->state);
631: ssh->state = NULL;
632: }
633: }
634:
635: void
636: ssh_packet_close(struct ssh *ssh)
637: {
638: ssh_packet_close_internal(ssh, 1);
639: }
640:
641: void
642: ssh_packet_clear_keys(struct ssh *ssh)
643: {
644: ssh_packet_close_internal(ssh, 0);
1.1 deraadt 645: }
646:
647: /* Sets remote side protocol flags. */
648:
1.2 provos 649: void
1.201 markus 650: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 651: {
1.201 markus 652: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 653: }
654:
655: /* Returns the remote protocol flags set earlier by the above function. */
656:
1.40 markus 657: u_int
1.201 markus 658: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 659: {
1.201 markus 660: return ssh->state->remote_protocol_flags;
1.1 deraadt 661: }
662:
1.16 markus 663: /*
664: * Starts packet compression from the next packet on in both directions.
665: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
666: */
1.1 deraadt 667:
1.201 markus 668: static int
669: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 670: {
1.201 markus 671: if (!ssh->state->compression_buffer &&
672: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
673: return SSH_ERR_ALLOC_FAIL;
674: return 0;
1.60 markus 675: }
676:
1.288 dtucker 677: #ifdef WITH_ZLIB
1.201 markus 678: static int
679: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 680: {
1.201 markus 681: if (level < 1 || level > 9)
682: return SSH_ERR_INVALID_ARGUMENT;
683: debug("Enabling compression at level %d.", level);
684: if (ssh->state->compression_out_started == 1)
685: deflateEnd(&ssh->state->compression_out_stream);
686: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
687: case Z_OK:
688: ssh->state->compression_out_started = 1;
689: break;
690: case Z_MEM_ERROR:
691: return SSH_ERR_ALLOC_FAIL;
692: default:
693: return SSH_ERR_INTERNAL_ERROR;
694: }
695: return 0;
1.1 deraadt 696: }
697:
1.201 markus 698: static int
699: start_compression_in(struct ssh *ssh)
700: {
701: if (ssh->state->compression_in_started == 1)
702: inflateEnd(&ssh->state->compression_in_stream);
703: switch (inflateInit(&ssh->state->compression_in_stream)) {
704: case Z_OK:
705: ssh->state->compression_in_started = 1;
706: break;
707: case Z_MEM_ERROR:
708: return SSH_ERR_ALLOC_FAIL;
709: default:
710: return SSH_ERR_INTERNAL_ERROR;
711: }
712: return 0;
1.95 markus 713: }
714:
1.201 markus 715: /* XXX remove need for separate compression buffer */
716: static int
717: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 718: {
1.201 markus 719: u_char buf[4096];
720: int r, status;
721:
722: if (ssh->state->compression_out_started != 1)
723: return SSH_ERR_INTERNAL_ERROR;
724:
725: /* This case is not handled below. */
726: if (sshbuf_len(in) == 0)
727: return 0;
728:
729: /* Input is the contents of the input buffer. */
730: if ((ssh->state->compression_out_stream.next_in =
731: sshbuf_mutable_ptr(in)) == NULL)
732: return SSH_ERR_INTERNAL_ERROR;
733: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
734:
735: /* Loop compressing until deflate() returns with avail_out != 0. */
736: do {
737: /* Set up fixed-size output buffer. */
738: ssh->state->compression_out_stream.next_out = buf;
739: ssh->state->compression_out_stream.avail_out = sizeof(buf);
740:
741: /* Compress as much data into the buffer as possible. */
742: status = deflate(&ssh->state->compression_out_stream,
743: Z_PARTIAL_FLUSH);
744: switch (status) {
745: case Z_MEM_ERROR:
746: return SSH_ERR_ALLOC_FAIL;
747: case Z_OK:
748: /* Append compressed data to output_buffer. */
749: if ((r = sshbuf_put(out, buf, sizeof(buf) -
750: ssh->state->compression_out_stream.avail_out)) != 0)
751: return r;
752: break;
753: case Z_STREAM_ERROR:
754: default:
755: ssh->state->compression_out_failures++;
756: return SSH_ERR_INVALID_FORMAT;
757: }
758: } while (ssh->state->compression_out_stream.avail_out == 0);
759: return 0;
1.1 deraadt 760: }
761:
1.201 markus 762: static int
763: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 764: {
1.201 markus 765: u_char buf[4096];
766: int r, status;
1.1 deraadt 767:
1.201 markus 768: if (ssh->state->compression_in_started != 1)
769: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 770:
1.201 markus 771: if ((ssh->state->compression_in_stream.next_in =
772: sshbuf_mutable_ptr(in)) == NULL)
773: return SSH_ERR_INTERNAL_ERROR;
774: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 775:
1.201 markus 776: for (;;) {
777: /* Set up fixed-size output buffer. */
778: ssh->state->compression_in_stream.next_out = buf;
779: ssh->state->compression_in_stream.avail_out = sizeof(buf);
780:
781: status = inflate(&ssh->state->compression_in_stream,
782: Z_PARTIAL_FLUSH);
783: switch (status) {
784: case Z_OK:
785: if ((r = sshbuf_put(out, buf, sizeof(buf) -
786: ssh->state->compression_in_stream.avail_out)) != 0)
787: return r;
788: break;
789: case Z_BUF_ERROR:
790: /*
791: * Comments in zlib.h say that we should keep calling
792: * inflate() until we get an error. This appears to
793: * be the error that we get.
794: */
795: return 0;
796: case Z_DATA_ERROR:
797: return SSH_ERR_INVALID_FORMAT;
798: case Z_MEM_ERROR:
799: return SSH_ERR_ALLOC_FAIL;
800: case Z_STREAM_ERROR:
801: default:
802: ssh->state->compression_in_failures++;
803: return SSH_ERR_INTERNAL_ERROR;
804: }
805: }
806: /* NOTREACHED */
1.170 djm 807: }
1.288 dtucker 808:
809: #else /* WITH_ZLIB */
810:
811: static int
812: start_compression_out(struct ssh *ssh, int level)
813: {
814: return SSH_ERR_INTERNAL_ERROR;
815: }
816:
817: static int
818: start_compression_in(struct ssh *ssh)
819: {
820: return SSH_ERR_INTERNAL_ERROR;
821: }
822:
823: static int
824: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
825: {
826: return SSH_ERR_INTERNAL_ERROR;
827: }
828:
829: static int
830: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
831: {
832: return SSH_ERR_INTERNAL_ERROR;
833: }
834: #endif /* WITH_ZLIB */
1.170 djm 835:
1.257 markus 836: void
837: ssh_clear_newkeys(struct ssh *ssh, int mode)
838: {
1.259 djm 839: if (ssh->kex && ssh->kex->newkeys[mode]) {
1.257 markus 840: kex_free_newkeys(ssh->kex->newkeys[mode]);
841: ssh->kex->newkeys[mode] = NULL;
842: }
843: }
844:
1.201 markus 845: int
846: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 847: {
1.201 markus 848: struct session_state *state = ssh->state;
849: struct sshenc *enc;
850: struct sshmac *mac;
851: struct sshcomp *comp;
1.235 djm 852: struct sshcipher_ctx **ccp;
1.236 markus 853: struct packet_state *ps;
1.105 markus 854: u_int64_t *max_blocks;
1.259 djm 855: const char *wmsg;
1.197 djm 856: int r, crypt_type;
1.283 djm 857: const char *dir = mode == MODE_OUT ? "out" : "in";
1.57 markus 858:
1.100 markus 859: debug2("set_newkeys: mode %d", mode);
1.57 markus 860:
1.88 markus 861: if (mode == MODE_OUT) {
1.235 djm 862: ccp = &state->send_context;
1.115 avsm 863: crypt_type = CIPHER_ENCRYPT;
1.236 markus 864: ps = &state->p_send;
1.201 markus 865: max_blocks = &state->max_blocks_out;
1.88 markus 866: } else {
1.235 djm 867: ccp = &state->receive_context;
1.115 avsm 868: crypt_type = CIPHER_DECRYPT;
1.236 markus 869: ps = &state->p_read;
1.201 markus 870: max_blocks = &state->max_blocks_in;
1.88 markus 871: }
1.201 markus 872: if (state->newkeys[mode] != NULL) {
1.283 djm 873: debug("%s: rekeying %s, input %llu bytes %llu blocks, "
874: "output %llu bytes %llu blocks", __func__, dir,
1.257 markus 875: (unsigned long long)state->p_read.bytes,
876: (unsigned long long)state->p_read.blocks,
877: (unsigned long long)state->p_send.bytes,
878: (unsigned long long)state->p_send.blocks);
879: kex_free_newkeys(state->newkeys[mode]);
880: state->newkeys[mode] = NULL;
1.57 markus 881: }
1.236 markus 882: /* note that both bytes and the seqnr are not reset */
883: ps->packets = ps->blocks = 0;
1.201 markus 884: /* move newkeys from kex to state */
885: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
886: return SSH_ERR_INTERNAL_ERROR;
887: ssh->kex->newkeys[mode] = NULL;
888: enc = &state->newkeys[mode]->enc;
889: mac = &state->newkeys[mode]->mac;
890: comp = &state->newkeys[mode]->comp;
891: if (cipher_authlen(enc->cipher) == 0) {
892: if ((r = mac_init(mac)) != 0)
893: return r;
894: }
895: mac->enabled = 1;
1.283 djm 896: DBG(debug("%s: cipher_init_context: %s", __func__, dir));
1.279 djm 897: cipher_free(*ccp);
898: *ccp = NULL;
1.235 djm 899: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 900: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 901: return r;
902: if (!state->cipher_warning_done &&
1.235 djm 903: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 904: error("Warning: %s", wmsg);
905: state->cipher_warning_done = 1;
906: }
1.91 markus 907: /* Deleting the keys does not gain extra security */
1.192 djm 908: /* explicit_bzero(enc->iv, enc->block_size);
909: explicit_bzero(enc->key, enc->key_len);
910: explicit_bzero(mac->key, mac->key_len); */
1.275 sf 911: if ((comp->type == COMP_ZLIB ||
912: (comp->type == COMP_DELAYED &&
913: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 914: if ((r = ssh_packet_init_compression(ssh)) < 0)
915: return r;
916: if (mode == MODE_OUT) {
917: if ((r = start_compression_out(ssh, 6)) != 0)
918: return r;
919: } else {
920: if ((r = start_compression_in(ssh)) != 0)
921: return r;
922: }
1.57 markus 923: comp->enabled = 1;
924: }
1.109 markus 925: /*
926: * The 2^(blocksize*2) limit is too expensive for 3DES,
1.254 djm 927: * so enforce a 1GB limit for small blocksizes.
1.261 dtucker 928: * See RFC4344 section 3.2.
1.109 markus 929: */
930: if (enc->block_size >= 16)
931: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
932: else
933: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 934: if (state->rekey_limit)
1.237 deraadt 935: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 936: state->rekey_limit / enc->block_size);
1.283 djm 937: debug("rekey %s after %llu blocks", dir,
938: (unsigned long long)*max_blocks);
1.201 markus 939: return 0;
1.57 markus 940: }
941:
1.228 djm 942: #define MAX_PACKETS (1U<<31)
943: static int
944: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
945: {
946: struct session_state *state = ssh->state;
947: u_int32_t out_blocks;
948:
949: /* XXX client can't cope with rekeying pre-auth */
950: if (!state->after_authentication)
951: return 0;
952:
953: /* Haven't keyed yet or KEX in progress. */
1.278 djm 954: if (ssh_packet_is_rekeying(ssh))
1.228 djm 955: return 0;
956:
957: /* Peer can't rekey */
958: if (ssh->compat & SSH_BUG_NOREKEY)
959: return 0;
960:
961: /*
962: * Permit one packet in or out per rekey - this allows us to
963: * make progress when rekey limits are very small.
964: */
965: if (state->p_send.packets == 0 && state->p_read.packets == 0)
966: return 0;
967:
968: /* Time-based rekeying */
969: if (state->rekey_interval != 0 &&
1.244 dtucker 970: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 971: return 1;
972:
1.261 dtucker 973: /*
974: * Always rekey when MAX_PACKETS sent in either direction
975: * As per RFC4344 section 3.1 we do this after 2^31 packets.
976: */
1.228 djm 977: if (state->p_send.packets > MAX_PACKETS ||
978: state->p_read.packets > MAX_PACKETS)
979: return 1;
980:
981: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 982: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 983: state->newkeys[MODE_OUT]->enc.block_size);
984: return (state->max_blocks_out &&
985: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
986: (state->max_blocks_in &&
987: (state->p_read.blocks > state->max_blocks_in));
988: }
989:
1.16 markus 990: /*
1.118 markus 991: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 992: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 993: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
994: */
1.201 markus 995: static int
996: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 997: {
1.201 markus 998: struct session_state *state = ssh->state;
999: struct sshcomp *comp = NULL;
1000: int r, mode;
1.118 markus 1001:
1002: /*
1003: * Remember that we are past the authentication step, so rekeying
1.275 sf 1004: * with COMP_DELAYED will turn on compression immediately.
1.118 markus 1005: */
1.201 markus 1006: state->after_authentication = 1;
1.118 markus 1007: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 1008: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 1009: if (state->newkeys[mode] == NULL)
1.145 markus 1010: continue;
1.201 markus 1011: comp = &state->newkeys[mode]->comp;
1.275 sf 1012: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 1013: if ((r = ssh_packet_init_compression(ssh)) != 0)
1014: return r;
1015: if (mode == MODE_OUT) {
1016: if ((r = start_compression_out(ssh, 6)) != 0)
1017: return r;
1018: } else {
1019: if ((r = start_compression_in(ssh)) != 0)
1020: return r;
1021: }
1.118 markus 1022: comp->enabled = 1;
1023: }
1024: }
1.201 markus 1025: return 0;
1.118 markus 1026: }
1027:
1.226 djm 1028: /* Used to mute debug logging for noisy packet types */
1.242 markus 1029: int
1.226 djm 1030: ssh_packet_log_type(u_char type)
1031: {
1032: switch (type) {
1033: case SSH2_MSG_CHANNEL_DATA:
1034: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1035: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1036: return 0;
1037: default:
1038: return 1;
1039: }
1040: }
1041:
1.118 markus 1042: /*
1.25 markus 1043: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1044: */
1.201 markus 1045: int
1046: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1047: {
1.201 markus 1048: struct session_state *state = ssh->state;
1.200 markus 1049: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1050: u_char tmp, padlen, pad = 0;
1.201 markus 1051: u_int authlen = 0, aadlen = 0;
1052: u_int len;
1053: struct sshenc *enc = NULL;
1054: struct sshmac *mac = NULL;
1055: struct sshcomp *comp = NULL;
1056: int r, block_size;
1057:
1058: if (state->newkeys[MODE_OUT] != NULL) {
1059: enc = &state->newkeys[MODE_OUT]->enc;
1060: mac = &state->newkeys[MODE_OUT]->mac;
1061: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1062: /* disable mac for authenticated encryption */
1063: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1064: mac = NULL;
1.25 markus 1065: }
1.88 markus 1066: block_size = enc ? enc->block_size : 8;
1.180 markus 1067: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1068:
1.201 markus 1069: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1070: if (ssh_packet_log_type(type))
1071: debug3("send packet: type %u", type);
1.25 markus 1072: #ifdef PACKET_DEBUG
1073: fprintf(stderr, "plain: ");
1.201 markus 1074: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1075: #endif
1076:
1077: if (comp && comp->enabled) {
1.201 markus 1078: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1079: /* skip header, compress only payload */
1.201 markus 1080: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1081: goto out;
1082: sshbuf_reset(state->compression_buffer);
1083: if ((r = compress_buffer(ssh, state->outgoing_packet,
1084: state->compression_buffer)) != 0)
1085: goto out;
1086: sshbuf_reset(state->outgoing_packet);
1087: if ((r = sshbuf_put(state->outgoing_packet,
1088: "\0\0\0\0\0", 5)) != 0 ||
1089: (r = sshbuf_putb(state->outgoing_packet,
1090: state->compression_buffer)) != 0)
1091: goto out;
1092: DBG(debug("compression: raw %d compressed %zd", len,
1093: sshbuf_len(state->outgoing_packet)));
1.25 markus 1094: }
1095:
1096: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1097: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1098:
1099: /*
1100: * calc size of padding, alloc space, get random data,
1101: * minimum padding is 4 bytes
1102: */
1.178 markus 1103: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1104: padlen = block_size - (len % block_size);
1105: if (padlen < 4)
1106: padlen += block_size;
1.201 markus 1107: if (state->extra_pad) {
1.233 djm 1108: tmp = state->extra_pad;
1.201 markus 1109: state->extra_pad =
1.237 deraadt 1110: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1111: /* check if roundup overflowed */
1112: if (state->extra_pad < tmp)
1113: return SSH_ERR_INVALID_ARGUMENT;
1114: tmp = (len + padlen) % state->extra_pad;
1115: /* Check whether pad calculation below will underflow */
1116: if (tmp > state->extra_pad)
1117: return SSH_ERR_INVALID_ARGUMENT;
1118: pad = state->extra_pad - tmp;
1.193 djm 1119: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1120: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1121: tmp = padlen;
1.71 markus 1122: padlen += pad;
1.233 djm 1123: /* Check whether padlen calculation overflowed */
1124: if (padlen < tmp)
1125: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1126: state->extra_pad = 0;
1.71 markus 1127: }
1.201 markus 1128: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1129: goto out;
1.235 djm 1130: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1131: /* random padding */
1.201 markus 1132: arc4random_buf(cp, padlen);
1.32 markus 1133: } else {
1134: /* clear padding */
1.192 djm 1135: explicit_bzero(cp, padlen);
1.25 markus 1136: }
1.178 markus 1137: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1138: len = sshbuf_len(state->outgoing_packet);
1139: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1140: if (cp == NULL) {
1141: r = SSH_ERR_INTERNAL_ERROR;
1142: goto out;
1143: }
1.25 markus 1144: /* packet_length includes payload, padding and padding length field */
1.201 markus 1145: POKE_U32(cp, len - 4);
1.89 markus 1146: cp[4] = padlen;
1.178 markus 1147: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1148: len, padlen, aadlen));
1.25 markus 1149:
1150: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1151: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1152: if ((r = mac_compute(mac, state->p_send.seqnr,
1153: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1154: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1155: goto out;
1156: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1157: }
1158: /* encrypt packet and append to output buffer. */
1.201 markus 1159: if ((r = sshbuf_reserve(state->output,
1160: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1161: goto out;
1.235 djm 1162: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1163: sshbuf_ptr(state->outgoing_packet),
1164: len - aadlen, aadlen, authlen)) != 0)
1165: goto out;
1.25 markus 1166: /* append unencrypted MAC */
1.178 markus 1167: if (mac && mac->enabled) {
1168: if (mac->etm) {
1169: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1170: if ((r = mac_compute(mac, state->p_send.seqnr,
1171: cp, len, macbuf, sizeof(macbuf))) != 0)
1172: goto out;
1.178 markus 1173: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1174: state->p_send.seqnr));
1.178 markus 1175: }
1.201 markus 1176: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1177: goto out;
1.178 markus 1178: }
1.25 markus 1179: #ifdef PACKET_DEBUG
1180: fprintf(stderr, "encrypted: ");
1.201 markus 1181: sshbuf_dump(state->output, stderr);
1.25 markus 1182: #endif
1.29 markus 1183: /* increment sequence number for outgoing packets */
1.201 markus 1184: if (++state->p_send.seqnr == 0)
1.106 itojun 1185: logit("outgoing seqnr wraps around");
1.201 markus 1186: if (++state->p_send.packets == 0)
1187: if (!(ssh->compat & SSH_BUG_NOREKEY))
1188: return SSH_ERR_NEED_REKEY;
1189: state->p_send.blocks += len / block_size;
1190: state->p_send.bytes += len;
1191: sshbuf_reset(state->outgoing_packet);
1.25 markus 1192:
1.57 markus 1193: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1194: r = ssh_set_newkeys(ssh, MODE_OUT);
1195: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1196: r = ssh_packet_enable_delayed_compress(ssh);
1197: else
1198: r = 0;
1199: out:
1200: return r;
1.25 markus 1201: }
1202:
1.228 djm 1203: /* returns non-zero if the specified packet type is usec by KEX */
1204: static int
1205: ssh_packet_type_is_kex(u_char type)
1206: {
1207: return
1208: type >= SSH2_MSG_TRANSPORT_MIN &&
1209: type <= SSH2_MSG_TRANSPORT_MAX &&
1210: type != SSH2_MSG_SERVICE_REQUEST &&
1211: type != SSH2_MSG_SERVICE_ACCEPT &&
1212: type != SSH2_MSG_EXT_INFO;
1213: }
1214:
1.201 markus 1215: int
1216: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1217: {
1.201 markus 1218: struct session_state *state = ssh->state;
1.105 markus 1219: struct packet *p;
1.201 markus 1220: u_char type;
1.228 djm 1221: int r, need_rekey;
1.105 markus 1222:
1.228 djm 1223: if (sshbuf_len(state->outgoing_packet) < 6)
1224: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1225: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1226: need_rekey = !ssh_packet_type_is_kex(type) &&
1227: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1228:
1.228 djm 1229: /*
1230: * During rekeying we can only send key exchange messages.
1231: * Queue everything else.
1232: */
1233: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1234: if (need_rekey)
1235: debug3("%s: rekex triggered", __func__);
1236: debug("enqueue packet: %u", type);
1237: p = calloc(1, sizeof(*p));
1238: if (p == NULL)
1239: return SSH_ERR_ALLOC_FAIL;
1240: p->type = type;
1241: p->payload = state->outgoing_packet;
1242: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1243: state->outgoing_packet = sshbuf_new();
1244: if (state->outgoing_packet == NULL)
1245: return SSH_ERR_ALLOC_FAIL;
1246: if (need_rekey) {
1247: /*
1248: * This packet triggered a rekey, so send the
1249: * KEXINIT now.
1250: * NB. reenters this function via kex_start_rekex().
1251: */
1252: return kex_start_rekex(ssh);
1.105 markus 1253: }
1.228 djm 1254: return 0;
1.105 markus 1255: }
1256:
1257: /* rekeying starts with sending KEXINIT */
1258: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1259: state->rekeying = 1;
1.105 markus 1260:
1.201 markus 1261: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1262: return r;
1.105 markus 1263:
1264: /* after a NEWKEYS message we can send the complete queue */
1265: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1266: state->rekeying = 0;
1267: state->rekey_time = monotime();
1268: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1269: type = p->type;
1.228 djm 1270: /*
1271: * If this packet triggers a rekex, then skip the
1272: * remaining packets in the queue for now.
1273: * NB. re-enters this function via kex_start_rekex.
1274: */
1275: if (ssh_packet_need_rekeying(ssh,
1276: sshbuf_len(p->payload))) {
1277: debug3("%s: queued packet triggered rekex",
1278: __func__);
1279: return kex_start_rekex(ssh);
1280: }
1.105 markus 1281: debug("dequeue packet: %u", type);
1.201 markus 1282: sshbuf_free(state->outgoing_packet);
1283: state->outgoing_packet = p->payload;
1284: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1285: memset(p, 0, sizeof(*p));
1.186 djm 1286: free(p);
1.201 markus 1287: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1288: return r;
1.105 markus 1289: }
1290: }
1.201 markus 1291: return 0;
1.25 markus 1292: }
1293:
1294: /*
1.16 markus 1295: * Waits until a packet has been received, and returns its type. Note that
1296: * no other data is processed until this returns, so this function should not
1297: * be used during the interactive session.
1298: */
1.1 deraadt 1299:
1.2 provos 1300: int
1.201 markus 1301: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1302: {
1.201 markus 1303: struct session_state *state = ssh->state;
1.222 markus 1304: int len, r, ms_remain;
1.56 millert 1305: fd_set *setp;
1.14 markus 1306: char buf[8192];
1.155 deraadt 1307: struct timeval timeout, start, *timeoutp = NULL;
1308:
1.25 markus 1309: DBG(debug("packet_read()"));
1.14 markus 1310:
1.214 deraadt 1311: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1312: NFDBITS), sizeof(fd_mask));
1.201 markus 1313: if (setp == NULL)
1314: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1315:
1.205 djm 1316: /*
1317: * Since we are blocking, ensure that all written packets have
1318: * been sent.
1319: */
1.210 markus 1320: if ((r = ssh_packet_write_wait(ssh)) != 0)
1321: goto out;
1.14 markus 1322:
1323: /* Stay in the loop until we have received a complete packet. */
1324: for (;;) {
1325: /* Try to read a packet from the buffer. */
1.201 markus 1326: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1327: if (r != 0)
1328: break;
1.14 markus 1329: /* If we got a packet, return it. */
1.201 markus 1330: if (*typep != SSH_MSG_NONE)
1331: break;
1.16 markus 1332: /*
1333: * Otherwise, wait for some data to arrive, add it to the
1334: * buffer, and try again.
1335: */
1.201 markus 1336: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1337: NFDBITS) * sizeof(fd_mask));
1.201 markus 1338: FD_SET(state->connection_in, setp);
1.16 markus 1339:
1.201 markus 1340: if (state->packet_timeout_ms > 0) {
1341: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1342: timeoutp = &timeout;
1343: }
1.14 markus 1344: /* Wait for some data to arrive. */
1.154 dtucker 1345: for (;;) {
1.291 markus 1346: if (state->packet_timeout_ms > 0) {
1.154 dtucker 1347: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1348: monotime_tv(&start);
1.154 dtucker 1349: }
1.201 markus 1350: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1351: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1352: break;
1.270 dtucker 1353: if (errno != EAGAIN && errno != EINTR) {
1354: r = SSH_ERR_SYSTEM_ERROR;
1355: goto out;
1356: }
1.291 markus 1357: if (state->packet_timeout_ms <= 0)
1.154 dtucker 1358: continue;
1359: ms_subtract_diff(&start, &ms_remain);
1360: if (ms_remain <= 0) {
1.201 markus 1361: r = 0;
1.154 dtucker 1362: break;
1363: }
1364: }
1.246 djm 1365: if (r == 0) {
1366: r = SSH_ERR_CONN_TIMEOUT;
1367: goto out;
1368: }
1.14 markus 1369: /* Read data from the socket. */
1.222 markus 1370: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1371: if (len == 0) {
1372: r = SSH_ERR_CONN_CLOSED;
1373: goto out;
1374: }
1.286 deraadt 1375: if (len == -1) {
1.210 markus 1376: r = SSH_ERR_SYSTEM_ERROR;
1377: goto out;
1378: }
1.204 djm 1379:
1.14 markus 1380: /* Append it to the buffer. */
1.204 djm 1381: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1382: goto out;
1.14 markus 1383: }
1.210 markus 1384: out:
1.201 markus 1385: free(setp);
1386: return r;
1.1 deraadt 1387: }
1388:
1.77 djm 1389: int
1.201 markus 1390: ssh_packet_read(struct ssh *ssh)
1.77 djm 1391: {
1.201 markus 1392: u_char type;
1393: int r;
1394:
1395: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1396: fatal("%s: %s", __func__, ssh_err(r));
1397: return type;
1.77 djm 1398: }
1399:
1.16 markus 1400: /*
1401: * Waits until a packet has been received, verifies that its type matches
1402: * that given, and gives a fatal error and exits if there is a mismatch.
1403: */
1.1 deraadt 1404:
1.205 djm 1405: int
1406: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1407: {
1.205 djm 1408: int r;
1409: u_char type;
1.1 deraadt 1410:
1.205 djm 1411: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1412: return r;
1413: if (type != expected_type) {
1414: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1415: "Protocol error: expected packet type %d, got %d",
1.205 djm 1416: expected_type, type)) != 0)
1417: return r;
1418: return SSH_ERR_PROTOCOL_ERROR;
1419: }
1420: return 0;
1.1 deraadt 1421: }
1.14 markus 1422:
1.242 markus 1423: static int
1424: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1425: {
1426: struct session_state *state = ssh->state;
1427: const u_char *cp;
1428: size_t need;
1429: int r;
1430:
1431: if (ssh->kex)
1432: return SSH_ERR_INTERNAL_ERROR;
1433: *typep = SSH_MSG_NONE;
1434: cp = sshbuf_ptr(state->input);
1435: if (state->packlen == 0) {
1436: if (sshbuf_len(state->input) < 4 + 1)
1437: return 0; /* packet is incomplete */
1438: state->packlen = PEEK_U32(cp);
1439: if (state->packlen < 4 + 1 ||
1440: state->packlen > PACKET_MAX_SIZE)
1441: return SSH_ERR_MESSAGE_INCOMPLETE;
1442: }
1443: need = state->packlen + 4;
1444: if (sshbuf_len(state->input) < need)
1445: return 0; /* packet is incomplete */
1446: sshbuf_reset(state->incoming_packet);
1447: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1448: state->packlen)) != 0 ||
1449: (r = sshbuf_consume(state->input, need)) != 0 ||
1450: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1451: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1452: return r;
1453: if (ssh_packet_log_type(*typep))
1454: debug3("%s: type %u", __func__, *typep);
1455: /* sshbuf_dump(state->incoming_packet, stderr); */
1456: /* reset for next packet */
1457: state->packlen = 0;
1458: return r;
1459: }
1460:
1.201 markus 1461: int
1462: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1463: {
1.201 markus 1464: struct session_state *state = ssh->state;
1.40 markus 1465: u_int padlen, need;
1.231 djm 1466: u_char *cp;
1.201 markus 1467: u_int maclen, aadlen = 0, authlen = 0, block_size;
1468: struct sshenc *enc = NULL;
1469: struct sshmac *mac = NULL;
1470: struct sshcomp *comp = NULL;
1.200 markus 1471: int r;
1.201 markus 1472:
1.242 markus 1473: if (state->mux)
1474: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1475:
1.201 markus 1476: *typep = SSH_MSG_NONE;
1477:
1478: if (state->packet_discard)
1479: return 0;
1480:
1481: if (state->newkeys[MODE_IN] != NULL) {
1482: enc = &state->newkeys[MODE_IN]->enc;
1483: mac = &state->newkeys[MODE_IN]->mac;
1484: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1485: /* disable mac for authenticated encryption */
1486: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1487: mac = NULL;
1.25 markus 1488: }
1489: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1490: block_size = enc ? enc->block_size : 8;
1.180 markus 1491: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1492:
1.201 markus 1493: if (aadlen && state->packlen == 0) {
1.235 djm 1494: if (cipher_get_length(state->receive_context,
1.201 markus 1495: &state->packlen, state->p_read.seqnr,
1496: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1497: return 0;
1498: if (state->packlen < 1 + 4 ||
1499: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1500: #ifdef PACKET_DEBUG
1.201 markus 1501: sshbuf_dump(state->input, stderr);
1.178 markus 1502: #endif
1.201 markus 1503: logit("Bad packet length %u.", state->packlen);
1504: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1505: return r;
1.217 djm 1506: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1507: }
1.201 markus 1508: sshbuf_reset(state->incoming_packet);
1509: } else if (state->packlen == 0) {
1.25 markus 1510: /*
1511: * check if input size is less than the cipher block size,
1512: * decrypt first block and extract length of incoming packet
1513: */
1.201 markus 1514: if (sshbuf_len(state->input) < block_size)
1515: return 0;
1516: sshbuf_reset(state->incoming_packet);
1517: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1518: &cp)) != 0)
1519: goto out;
1.235 djm 1520: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1521: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1522: block_size, 0, 0)) != 0)
1523: goto out;
1524: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1525: if (state->packlen < 1 + 4 ||
1526: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1527: #ifdef PACKET_DEBUG
1.201 markus 1528: fprintf(stderr, "input: \n");
1529: sshbuf_dump(state->input, stderr);
1530: fprintf(stderr, "incoming_packet: \n");
1531: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1532: #endif
1.201 markus 1533: logit("Bad packet length %u.", state->packlen);
1.234 markus 1534: return ssh_packet_start_discard(ssh, enc, mac, 0,
1535: PACKET_MAX_SIZE);
1.25 markus 1536: }
1.201 markus 1537: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1538: goto out;
1.25 markus 1539: }
1.201 markus 1540: DBG(debug("input: packet len %u", state->packlen+4));
1541:
1.178 markus 1542: if (aadlen) {
1543: /* only the payload is encrypted */
1.201 markus 1544: need = state->packlen;
1.178 markus 1545: } else {
1546: /*
1547: * the payload size and the payload are encrypted, but we
1548: * have a partial packet of block_size bytes
1549: */
1.201 markus 1550: need = 4 + state->packlen - block_size;
1.178 markus 1551: }
1.180 markus 1552: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1553: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1554: if (need % block_size != 0) {
1555: logit("padding error: need %d block %d mod %d",
1.25 markus 1556: need, block_size, need % block_size);
1.234 markus 1557: return ssh_packet_start_discard(ssh, enc, mac, 0,
1558: PACKET_MAX_SIZE - block_size);
1.158 markus 1559: }
1.25 markus 1560: /*
1561: * check if the entire packet has been received and
1.178 markus 1562: * decrypt into incoming_packet:
1563: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1564: * 'need' bytes are encrypted, followed by either
1565: * 'authlen' bytes of authentication tag or
1.178 markus 1566: * 'maclen' bytes of message authentication code.
1.25 markus 1567: */
1.201 markus 1568: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1569: return 0; /* packet is incomplete */
1.25 markus 1570: #ifdef PACKET_DEBUG
1571: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1572: sshbuf_dump(state->input, stderr);
1.25 markus 1573: #endif
1.231 djm 1574: /* EtM: check mac over encrypted input */
1.201 markus 1575: if (mac && mac->enabled && mac->etm) {
1.231 djm 1576: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1577: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1578: sshbuf_ptr(state->input) + aadlen + need + authlen,
1579: maclen)) != 0) {
1580: if (r == SSH_ERR_MAC_INVALID)
1581: logit("Corrupted MAC on input.");
1.201 markus 1582: goto out;
1.231 djm 1583: }
1.201 markus 1584: }
1585: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1586: &cp)) != 0)
1587: goto out;
1.235 djm 1588: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1589: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1590: goto out;
1591: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1592: goto out;
1.29 markus 1593: if (mac && mac->enabled) {
1.231 djm 1594: /* Not EtM: check MAC over cleartext */
1595: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1596: sshbuf_ptr(state->incoming_packet),
1597: sshbuf_len(state->incoming_packet),
1598: sshbuf_ptr(state->input), maclen)) != 0) {
1599: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1600: goto out;
1.159 markus 1601: logit("Corrupted MAC on input.");
1.247 markus 1602: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1603: return SSH_ERR_INTERNAL_ERROR;
1604: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1605: sshbuf_len(state->incoming_packet),
1.247 markus 1606: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1607: }
1.231 djm 1608: /* Remove MAC from input buffer */
1.201 markus 1609: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1610: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1611: goto out;
1.25 markus 1612: }
1.77 djm 1613: if (seqnr_p != NULL)
1.201 markus 1614: *seqnr_p = state->p_read.seqnr;
1615: if (++state->p_read.seqnr == 0)
1.106 itojun 1616: logit("incoming seqnr wraps around");
1.201 markus 1617: if (++state->p_read.packets == 0)
1618: if (!(ssh->compat & SSH_BUG_NOREKEY))
1619: return SSH_ERR_NEED_REKEY;
1620: state->p_read.blocks += (state->packlen + 4) / block_size;
1621: state->p_read.bytes += state->packlen + 4;
1.25 markus 1622:
1623: /* get padlen */
1.201 markus 1624: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1625: DBG(debug("input: padlen %d", padlen));
1.205 djm 1626: if (padlen < 4) {
1627: if ((r = sshpkt_disconnect(ssh,
1628: "Corrupted padlen %d on input.", padlen)) != 0 ||
1629: (r = ssh_packet_write_wait(ssh)) != 0)
1630: return r;
1631: return SSH_ERR_CONN_CORRUPT;
1632: }
1.25 markus 1633:
1634: /* skip packet size + padlen, discard padding */
1.201 markus 1635: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1636: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1637: goto out;
1.25 markus 1638:
1.201 markus 1639: DBG(debug("input: len before de-compress %zd",
1640: sshbuf_len(state->incoming_packet)));
1.25 markus 1641: if (comp && comp->enabled) {
1.201 markus 1642: sshbuf_reset(state->compression_buffer);
1643: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1644: state->compression_buffer)) != 0)
1645: goto out;
1646: sshbuf_reset(state->incoming_packet);
1647: if ((r = sshbuf_putb(state->incoming_packet,
1648: state->compression_buffer)) != 0)
1649: goto out;
1650: DBG(debug("input: len after de-compress %zd",
1651: sshbuf_len(state->incoming_packet)));
1.25 markus 1652: }
1653: /*
1654: * get packet type, implies consume.
1655: * return length of payload (without type field)
1656: */
1.201 markus 1657: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1658: goto out;
1.226 djm 1659: if (ssh_packet_log_type(*typep))
1660: debug3("receive packet: type %u", *typep);
1.205 djm 1661: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1662: if ((r = sshpkt_disconnect(ssh,
1663: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1664: (r = ssh_packet_write_wait(ssh)) != 0)
1665: return r;
1666: return SSH_ERR_PROTOCOL_ERROR;
1667: }
1.243 djm 1668: if (state->hook_in != NULL &&
1669: (r = state->hook_in(ssh, state->incoming_packet, typep,
1670: state->hook_in_ctx)) != 0)
1671: return r;
1.238 markus 1672: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1673: r = ssh_packet_enable_delayed_compress(ssh);
1674: else
1675: r = 0;
1.25 markus 1676: #ifdef PACKET_DEBUG
1.201 markus 1677: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1678: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1679: #endif
1.62 markus 1680: /* reset for next packet */
1.201 markus 1681: state->packlen = 0;
1.228 djm 1682:
1683: /* do we need to rekey? */
1684: if (ssh_packet_need_rekeying(ssh, 0)) {
1685: debug3("%s: rekex triggered", __func__);
1686: if ((r = kex_start_rekex(ssh)) != 0)
1687: return r;
1688: }
1.201 markus 1689: out:
1690: return r;
1.25 markus 1691: }
1692:
1693: int
1.201 markus 1694: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1695: {
1.201 markus 1696: struct session_state *state = ssh->state;
1.96 deraadt 1697: u_int reason, seqnr;
1.201 markus 1698: int r;
1699: u_char *msg;
1.62 markus 1700:
1.25 markus 1701: for (;;) {
1.201 markus 1702: msg = NULL;
1.249 djm 1703: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1704: if (r != 0)
1705: return r;
1706: if (*typep) {
1707: state->keep_alive_timeouts = 0;
1708: DBG(debug("received packet type %d", *typep));
1709: }
1710: switch (*typep) {
1711: case SSH2_MSG_IGNORE:
1712: debug3("Received SSH2_MSG_IGNORE");
1713: break;
1714: case SSH2_MSG_DEBUG:
1715: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1716: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1717: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1718: free(msg);
1.201 markus 1719: return r;
1.48 stevesk 1720: }
1.249 djm 1721: debug("Remote: %.900s", msg);
1722: free(msg);
1723: break;
1724: case SSH2_MSG_DISCONNECT:
1725: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1726: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1727: return r;
1728: /* Ignore normal client exit notifications */
1729: do_log2(ssh->state->server_side &&
1730: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1731: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1732: "Received disconnect from %s port %d:"
1733: "%u: %.400s", ssh_remote_ipaddr(ssh),
1734: ssh_remote_port(ssh), reason, msg);
1735: free(msg);
1736: return SSH_ERR_DISCONNECTED;
1737: case SSH2_MSG_UNIMPLEMENTED:
1738: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1739: return r;
1740: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1741: seqnr);
1742: break;
1743: default:
1744: return 0;
1.25 markus 1745: }
1746: }
1747: }
1748:
1.16 markus 1749: /*
1750: * Buffers the given amount of input characters. This is intended to be used
1751: * together with packet_read_poll.
1752: */
1.1 deraadt 1753:
1.204 djm 1754: int
1.201 markus 1755: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1756: {
1.201 markus 1757: struct session_state *state = ssh->state;
1758: int r;
1759:
1760: if (state->packet_discard) {
1761: state->keep_alive_timeouts = 0; /* ?? */
1762: if (len >= state->packet_discard) {
1763: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1764: return r;
1.201 markus 1765: }
1766: state->packet_discard -= len;
1.204 djm 1767: return 0;
1.159 markus 1768: }
1.201 markus 1769: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1770: return r;
1771:
1772: return 0;
1.28 markus 1773: }
1774:
1775: int
1.201 markus 1776: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1777: {
1.201 markus 1778: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1779: }
1780:
1.16 markus 1781: /*
1782: * Sends a diagnostic message from the server to the client. This message
1783: * can be sent at any time (but not while constructing another message). The
1784: * message is printed immediately, but only if the client is being executed
1785: * in verbose mode. These messages are primarily intended to ease debugging
1786: * authentication problems. The length of the formatted message must not
1.205 djm 1787: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1788: */
1.2 provos 1789: void
1.201 markus 1790: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1791: {
1.14 markus 1792: char buf[1024];
1793: va_list args;
1.201 markus 1794: int r;
1.39 markus 1795:
1.249 djm 1796: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1797: return;
1.14 markus 1798:
1799: va_start(args, fmt);
1800: vsnprintf(buf, sizeof(buf), fmt, args);
1801: va_end(args);
1.265 djm 1802:
1803: debug3("sending debug message: %s", buf);
1.14 markus 1804:
1.249 djm 1805: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1806: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1807: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1808: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1809: (r = sshpkt_send(ssh)) != 0 ||
1810: (r = ssh_packet_write_wait(ssh)) != 0)
1.205 djm 1811: fatal("%s: %s", __func__, ssh_err(r));
1812: }
1813:
1.268 dtucker 1814: void
1815: sshpkt_fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1.245 djm 1816: {
1817: snprintf(s, l, "%.200s%s%s port %d",
1818: ssh->log_preamble ? ssh->log_preamble : "",
1819: ssh->log_preamble ? " " : "",
1820: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1821: }
1822:
1.205 djm 1823: /*
1824: * Pretty-print connection-terminating errors and exit.
1825: */
1.280 djm 1826: static void
1827: sshpkt_vfatal(struct ssh *ssh, int r, const char *fmt, va_list ap)
1.205 djm 1828: {
1.280 djm 1829: char *tag = NULL, remote_id[512];
1.290 djm 1830: int oerrno = errno;
1.245 djm 1831:
1.268 dtucker 1832: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.245 djm 1833:
1.205 djm 1834: switch (r) {
1835: case SSH_ERR_CONN_CLOSED:
1.257 markus 1836: ssh_packet_clear_keys(ssh);
1.245 djm 1837: logdie("Connection closed by %s", remote_id);
1.205 djm 1838: case SSH_ERR_CONN_TIMEOUT:
1.257 markus 1839: ssh_packet_clear_keys(ssh);
1.245 djm 1840: logdie("Connection %s %s timed out",
1841: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1842: case SSH_ERR_DISCONNECTED:
1.257 markus 1843: ssh_packet_clear_keys(ssh);
1.245 djm 1844: logdie("Disconnected from %s", remote_id);
1.212 djm 1845: case SSH_ERR_SYSTEM_ERROR:
1.257 markus 1846: if (errno == ECONNRESET) {
1847: ssh_packet_clear_keys(ssh);
1.245 djm 1848: logdie("Connection reset by %s", remote_id);
1.257 markus 1849: }
1.213 djm 1850: /* FALLTHROUGH */
1851: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1852: case SSH_ERR_NO_MAC_ALG_MATCH:
1853: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1854: case SSH_ERR_NO_KEX_ALG_MATCH:
1855: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1856: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.257 markus 1857: ssh_packet_clear_keys(ssh);
1.290 djm 1858: errno = oerrno;
1.245 djm 1859: logdie("Unable to negotiate with %s: %s. "
1860: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1861: ssh->kex->failed_choice);
1.212 djm 1862: }
1863: /* FALLTHROUGH */
1.205 djm 1864: default:
1.280 djm 1865: if (vasprintf(&tag, fmt, ap) == -1) {
1866: ssh_packet_clear_keys(ssh);
1867: logdie("%s: could not allocate failure message",
1868: __func__);
1869: }
1.257 markus 1870: ssh_packet_clear_keys(ssh);
1.290 djm 1871: errno = oerrno;
1.245 djm 1872: logdie("%s%sConnection %s %s: %s",
1.205 djm 1873: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 1874: ssh->state->server_side ? "from" : "to",
1.245 djm 1875: remote_id, ssh_err(r));
1.205 djm 1876: }
1.1 deraadt 1877: }
1878:
1.280 djm 1879: void
1880: sshpkt_fatal(struct ssh *ssh, int r, const char *fmt, ...)
1881: {
1882: va_list ap;
1883:
1884: va_start(ap, fmt);
1885: sshpkt_vfatal(ssh, r, fmt, ap);
1886: /* NOTREACHED */
1887: va_end(ap);
1888: logdie("%s: should have exited", __func__);
1889: }
1890:
1.16 markus 1891: /*
1892: * Logs the error plus constructs and sends a disconnect packet, closes the
1893: * connection, and exits. This function never returns. The error message
1894: * should not contain a newline. The length of the formatted message must
1895: * not exceed 1024 bytes.
1896: */
1.2 provos 1897: void
1.201 markus 1898: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1899: {
1.245 djm 1900: char buf[1024], remote_id[512];
1.14 markus 1901: va_list args;
1902: static int disconnecting = 0;
1.201 markus 1903: int r;
1.97 deraadt 1904:
1.14 markus 1905: if (disconnecting) /* Guard against recursive invocations. */
1906: fatal("packet_disconnect called recursively.");
1907: disconnecting = 1;
1908:
1.16 markus 1909: /*
1910: * Format the message. Note that the caller must make sure the
1911: * message is of limited size.
1912: */
1.268 dtucker 1913: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1914: va_start(args, fmt);
1915: vsnprintf(buf, sizeof(buf), fmt, args);
1916: va_end(args);
1917:
1.99 markus 1918: /* Display the error locally */
1.245 djm 1919: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1920:
1.205 djm 1921: /*
1922: * Send the disconnect message to the other side, and wait
1923: * for it to get sent.
1924: */
1925: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1.280 djm 1926: sshpkt_fatal(ssh, r, "%s", __func__);
1.205 djm 1927:
1928: if ((r = ssh_packet_write_wait(ssh)) != 0)
1.280 djm 1929: sshpkt_fatal(ssh, r, "%s", __func__);
1.14 markus 1930:
1931: /* Close the connection. */
1.201 markus 1932: ssh_packet_close(ssh);
1.112 markus 1933: cleanup_exit(255);
1.1 deraadt 1934: }
1935:
1.205 djm 1936: /*
1937: * Checks if there is any buffered output, and tries to write some of
1938: * the output.
1939: */
1940: int
1.201 markus 1941: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1942: {
1.201 markus 1943: struct session_state *state = ssh->state;
1944: int len = sshbuf_len(state->output);
1.222 markus 1945: int r;
1.97 deraadt 1946:
1.14 markus 1947: if (len > 0) {
1.222 markus 1948: len = write(state->connection_out,
1949: sshbuf_ptr(state->output), len);
1.156 djm 1950: if (len == -1) {
1951: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1952: return 0;
1953: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1954: }
1.222 markus 1955: if (len == 0)
1.205 djm 1956: return SSH_ERR_CONN_CLOSED;
1.201 markus 1957: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1958: return r;
1.14 markus 1959: }
1.205 djm 1960: return 0;
1.1 deraadt 1961: }
1962:
1.16 markus 1963: /*
1964: * Calls packet_write_poll repeatedly until all pending output data has been
1965: * written.
1966: */
1.205 djm 1967: int
1.201 markus 1968: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1969: {
1.56 millert 1970: fd_set *setp;
1.205 djm 1971: int ret, r, ms_remain = 0;
1.154 dtucker 1972: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1973: struct session_state *state = ssh->state;
1.56 millert 1974:
1.214 deraadt 1975: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1976: NFDBITS), sizeof(fd_mask));
1.201 markus 1977: if (setp == NULL)
1.205 djm 1978: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1979: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1980: free(setp);
1.215 djm 1981: return r;
1.216 gsoares 1982: }
1.201 markus 1983: while (ssh_packet_have_data_to_write(ssh)) {
1984: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1985: NFDBITS) * sizeof(fd_mask));
1.201 markus 1986: FD_SET(state->connection_out, setp);
1.154 dtucker 1987:
1.201 markus 1988: if (state->packet_timeout_ms > 0) {
1989: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1990: timeoutp = &timeout;
1991: }
1992: for (;;) {
1.291 markus 1993: if (state->packet_timeout_ms > 0) {
1.154 dtucker 1994: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1995: monotime_tv(&start);
1.154 dtucker 1996: }
1.201 markus 1997: if ((ret = select(state->connection_out + 1,
1.161 andreas 1998: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1999: break;
1.161 andreas 2000: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 2001: break;
1.291 markus 2002: if (state->packet_timeout_ms <= 0)
1.154 dtucker 2003: continue;
2004: ms_subtract_diff(&start, &ms_remain);
2005: if (ms_remain <= 0) {
2006: ret = 0;
2007: break;
2008: }
2009: }
2010: if (ret == 0) {
1.205 djm 2011: free(setp);
2012: return SSH_ERR_CONN_TIMEOUT;
2013: }
2014: if ((r = ssh_packet_write_poll(ssh)) != 0) {
2015: free(setp);
2016: return r;
1.154 dtucker 2017: }
1.14 markus 2018: }
1.186 djm 2019: free(setp);
1.205 djm 2020: return 0;
1.1 deraadt 2021: }
2022:
2023: /* Returns true if there is buffered data to write to the connection. */
2024:
1.2 provos 2025: int
1.201 markus 2026: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 2027: {
1.201 markus 2028: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 2029: }
2030:
2031: /* Returns true if there is not too much data to write to the connection. */
2032:
1.2 provos 2033: int
1.201 markus 2034: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 2035: {
1.201 markus 2036: if (ssh->state->interactive_mode)
2037: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 2038: else
1.201 markus 2039: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 2040: }
2041:
1.201 markus 2042: void
2043: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 2044: {
1.263 djm 2045: if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
1.101 markus 2046: return;
1.201 markus 2047: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 2048: case AF_INET:
2049: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 2050: if (setsockopt(ssh->state->connection_in,
1.286 deraadt 2051: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) == -1)
1.173 djm 2052: error("setsockopt IP_TOS %d: %.100s:",
2053: tos, strerror(errno));
2054: break;
2055: case AF_INET6:
2056: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 2057: if (setsockopt(ssh->state->connection_in,
1.286 deraadt 2058: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) == -1)
1.173 djm 2059: error("setsockopt IPV6_TCLASS %d: %.100s:",
2060: tos, strerror(errno));
2061: break;
2062: }
1.101 markus 2063: }
2064:
1.1 deraadt 2065: /* Informs that the current session is interactive. Sets IP flags for that. */
2066:
1.2 provos 2067: void
1.201 markus 2068: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2069: {
1.201 markus 2070: struct session_state *state = ssh->state;
2071:
2072: if (state->set_interactive_called)
1.43 markus 2073: return;
1.201 markus 2074: state->set_interactive_called = 1;
1.1 deraadt 2075:
1.14 markus 2076: /* Record that we are in interactive mode. */
1.201 markus 2077: state->interactive_mode = interactive;
1.1 deraadt 2078:
1.19 markus 2079: /* Only set socket options if using a socket. */
1.201 markus 2080: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2081: return;
1.201 markus 2082: set_nodelay(state->connection_in);
2083: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2084: qos_bulk);
1.1 deraadt 2085: }
2086:
2087: /* Returns true if the current connection is interactive. */
2088:
1.2 provos 2089: int
1.201 markus 2090: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2091: {
1.201 markus 2092: return ssh->state->interactive_mode;
1.12 markus 2093: }
2094:
1.113 deraadt 2095: int
1.201 markus 2096: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2097: {
1.201 markus 2098: struct session_state *state = ssh->state;
2099:
2100: if (state->set_maxsize_called) {
1.106 itojun 2101: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2102: state->max_packet_size, s);
1.14 markus 2103: return -1;
2104: }
2105: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2106: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2107: return -1;
2108: }
1.201 markus 2109: state->set_maxsize_called = 1;
1.66 markus 2110: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2111: state->max_packet_size = s;
1.14 markus 2112: return s;
1.53 markus 2113: }
2114:
1.161 andreas 2115: int
1.201 markus 2116: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2117: {
1.201 markus 2118: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2119: }
2120:
2121: void
1.201 markus 2122: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2123: {
1.201 markus 2124: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2125: }
2126:
2127: u_int
1.201 markus 2128: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2129: {
1.201 markus 2130: return ssh->state->max_packet_size;
1.71 markus 2131: }
2132:
1.105 markus 2133: void
1.244 dtucker 2134: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2135: {
1.244 dtucker 2136: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2137: (unsigned int)seconds);
1.201 markus 2138: ssh->state->rekey_limit = bytes;
2139: ssh->state->rekey_interval = seconds;
1.184 dtucker 2140: }
2141:
2142: time_t
1.201 markus 2143: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2144: {
2145: time_t seconds;
2146:
1.201 markus 2147: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2148: monotime();
1.185 dtucker 2149: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2150: }
2151:
2152: void
1.201 markus 2153: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2154: {
1.201 markus 2155: ssh->state->server_side = 1;
1.278 djm 2156: ssh->kex->server = 1; /* XXX unify? */
1.118 markus 2157: }
2158:
2159: void
1.201 markus 2160: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2161: {
1.201 markus 2162: ssh->state->after_authentication = 1;
1.161 andreas 2163: }
2164:
2165: void *
1.201 markus 2166: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2167: {
1.201 markus 2168: return (void *)ssh->state->input;
1.161 andreas 2169: }
2170:
2171: void *
1.201 markus 2172: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2173: {
1.201 markus 2174: return (void *)ssh->state->output;
1.166 andreas 2175: }
2176:
1.196 markus 2177: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2178: static int
2179: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2180: {
1.239 djm 2181: int r;
1.196 markus 2182:
2183: debug("%s: called", __func__);
2184: /* This was set in net child, but is not visible in user child */
1.201 markus 2185: ssh->state->after_authentication = 1;
2186: ssh->state->rekeying = 0;
1.239 djm 2187: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2188: return r;
1.201 markus 2189: return 0;
2190: }
2191:
2192: /* Packet state (de-)serialization for privsep */
2193:
2194: /* turn kex into a blob for packet state serialization */
2195: static int
2196: kex_to_blob(struct sshbuf *m, struct kex *kex)
2197: {
2198: int r;
2199:
2200: if ((r = sshbuf_put_string(m, kex->session_id,
2201: kex->session_id_len)) != 0 ||
2202: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
1.269 djm 2203: (r = sshbuf_put_cstring(m, kex->hostkey_alg)) != 0 ||
1.201 markus 2204: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
1.269 djm 2205: (r = sshbuf_put_u32(m, kex->hostkey_nid)) != 0 ||
1.201 markus 2206: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2207: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2208: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
1.278 djm 2209: (r = sshbuf_put_stringb(m, kex->client_version)) != 0 ||
2210: (r = sshbuf_put_stringb(m, kex->server_version)) != 0 ||
2211: (r = sshbuf_put_u32(m, kex->flags)) != 0)
1.201 markus 2212: return r;
2213: return 0;
2214: }
2215:
2216: /* turn key exchange results into a blob for packet state serialization */
2217: static int
2218: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2219: {
2220: struct sshbuf *b;
2221: struct sshcipher_ctx *cc;
2222: struct sshcomp *comp;
2223: struct sshenc *enc;
2224: struct sshmac *mac;
2225: struct newkeys *newkey;
2226: int r;
2227:
2228: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2229: return SSH_ERR_INTERNAL_ERROR;
2230: enc = &newkey->enc;
2231: mac = &newkey->mac;
2232: comp = &newkey->comp;
1.235 djm 2233: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2234: ssh->state->receive_context;
1.201 markus 2235: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2236: return r;
2237: if ((b = sshbuf_new()) == NULL)
2238: return SSH_ERR_ALLOC_FAIL;
2239: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2240: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2241: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2242: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2243: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2244: goto out;
2245: if (cipher_authlen(enc->cipher) == 0) {
2246: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2247: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2248: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2249: goto out;
2250: }
2251: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2252: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2253: goto out;
2254: r = sshbuf_put_stringb(m, b);
2255: out:
1.221 mmcc 2256: sshbuf_free(b);
1.201 markus 2257: return r;
2258: }
2259:
2260: /* serialize packet state into a blob */
2261: int
2262: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2263: {
2264: struct session_state *state = ssh->state;
1.249 djm 2265: int r;
1.201 markus 2266:
1.249 djm 2267: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2268: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2269: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2270: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2271: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2272: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2273: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2274: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2275: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2276: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2277: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2278: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2279: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2280: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2281: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 2282: return r;
1.201 markus 2283:
2284: return 0;
2285: }
2286:
2287: /* restore key exchange results from blob for packet state de-serialization */
2288: static int
2289: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2290: {
2291: struct sshbuf *b = NULL;
2292: struct sshcomp *comp;
2293: struct sshenc *enc;
2294: struct sshmac *mac;
2295: struct newkeys *newkey = NULL;
2296: size_t keylen, ivlen, maclen;
2297: int r;
2298:
2299: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2300: r = SSH_ERR_ALLOC_FAIL;
2301: goto out;
2302: }
2303: if ((r = sshbuf_froms(m, &b)) != 0)
2304: goto out;
2305: #ifdef DEBUG_PK
2306: sshbuf_dump(b, stderr);
2307: #endif
2308: enc = &newkey->enc;
2309: mac = &newkey->mac;
2310: comp = &newkey->comp;
2311:
2312: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2313: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2314: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2315: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2316: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2317: goto out;
1.262 djm 2318: if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2319: r = SSH_ERR_INVALID_FORMAT;
2320: goto out;
2321: }
1.201 markus 2322: if (cipher_authlen(enc->cipher) == 0) {
2323: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2324: goto out;
2325: if ((r = mac_setup(mac, mac->name)) != 0)
2326: goto out;
2327: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2328: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2329: goto out;
2330: if (maclen > mac->key_len) {
2331: r = SSH_ERR_INVALID_FORMAT;
2332: goto out;
2333: }
2334: mac->key_len = maclen;
2335: }
2336: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2337: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2338: goto out;
2339: if (sshbuf_len(b) != 0) {
2340: r = SSH_ERR_INVALID_FORMAT;
2341: goto out;
2342: }
2343: enc->key_len = keylen;
2344: enc->iv_len = ivlen;
2345: ssh->kex->newkeys[mode] = newkey;
2346: newkey = NULL;
2347: r = 0;
2348: out:
1.219 mmcc 2349: free(newkey);
1.221 mmcc 2350: sshbuf_free(b);
1.201 markus 2351: return r;
2352: }
2353:
2354: /* restore kex from blob for packet state de-serialization */
2355: static int
2356: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2357: {
2358: struct kex *kex;
2359: int r;
2360:
1.278 djm 2361: if ((kex = kex_new()) == NULL)
2362: return SSH_ERR_ALLOC_FAIL;
1.201 markus 2363: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2364: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
1.269 djm 2365: (r = sshbuf_get_cstring(m, &kex->hostkey_alg, NULL)) != 0 ||
1.201 markus 2366: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
1.269 djm 2367: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_nid)) != 0 ||
1.201 markus 2368: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2369: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2370: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
1.278 djm 2371: (r = sshbuf_get_stringb(m, kex->client_version)) != 0 ||
2372: (r = sshbuf_get_stringb(m, kex->server_version)) != 0 ||
2373: (r = sshbuf_get_u32(m, &kex->flags)) != 0)
1.201 markus 2374: goto out;
2375: kex->server = 1;
2376: kex->done = 1;
2377: r = 0;
2378: out:
2379: if (r != 0 || kexp == NULL) {
1.278 djm 2380: kex_free(kex);
1.201 markus 2381: if (kexp != NULL)
2382: *kexp = NULL;
2383: } else {
1.278 djm 2384: kex_free(*kexp);
1.201 markus 2385: *kexp = kex;
2386: }
2387: return r;
2388: }
2389:
2390: /*
2391: * Restore packet state from content of blob 'm' (de-serialization).
2392: * Note that 'm' will be partially consumed on parsing or any other errors.
2393: */
2394: int
2395: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2396: {
2397: struct session_state *state = ssh->state;
1.254 djm 2398: const u_char *input, *output;
2399: size_t ilen, olen;
1.201 markus 2400: int r;
2401:
1.249 djm 2402: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2403: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2404: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2405: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2406: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2407: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2408: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2409: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2410: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2411: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2412: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2413: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2414: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2415: return r;
2416: /*
2417: * We set the time here so that in post-auth privsep slave we
2418: * count from the completion of the authentication.
2419: */
2420: state->rekey_time = monotime();
2421: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2422: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2423: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2424: return r;
1.201 markus 2425:
1.239 djm 2426: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2427: return r;
2428:
2429: sshbuf_reset(state->input);
2430: sshbuf_reset(state->output);
2431: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2432: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2433: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2434: (r = sshbuf_put(state->output, output, olen)) != 0)
2435: return r;
2436:
2437: if (sshbuf_len(m))
2438: return SSH_ERR_INVALID_FORMAT;
2439: debug3("%s: done", __func__);
2440: return 0;
2441: }
2442:
2443: /* NEW API */
2444:
2445: /* put data to the outgoing packet */
2446:
2447: int
2448: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2449: {
2450: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2451: }
2452:
2453: int
2454: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2455: {
2456: return sshbuf_putb(ssh->state->outgoing_packet, b);
2457: }
2458:
2459: int
2460: sshpkt_put_u8(struct ssh *ssh, u_char val)
2461: {
2462: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2463: }
2464:
2465: int
2466: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2467: {
2468: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2469: }
2470:
2471: int
2472: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2473: {
2474: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2475: }
2476:
2477: int
2478: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2479: {
2480: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2481: }
2482:
2483: int
2484: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2485: {
2486: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2487: }
2488:
2489: int
2490: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2491: {
2492: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2493: }
2494:
1.211 djm 2495: #ifdef WITH_OPENSSL
1.201 markus 2496: int
2497: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2498: {
2499: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2500: }
2501:
2502:
2503: int
2504: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2505: {
2506: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2507: }
1.211 djm 2508: #endif /* WITH_OPENSSL */
1.201 markus 2509:
2510: /* fetch data from the incoming packet */
2511:
2512: int
2513: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2514: {
2515: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2516: }
2517:
2518: int
2519: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2520: {
2521: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2522: }
2523:
2524: int
2525: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2526: {
2527: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2528: }
2529:
2530: int
2531: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2532: {
2533: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2534: }
2535:
2536: int
2537: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2538: {
2539: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2540: }
2541:
2542: int
2543: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2544: {
2545: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2546: }
2547:
2548: int
1.264 djm 2549: sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2550: {
2551: return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2552: }
2553:
2554: int
1.201 markus 2555: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2556: {
2557: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
1.282 djm 2558: }
2559:
2560: int
2561: sshpkt_getb_froms(struct ssh *ssh, struct sshbuf **valp)
2562: {
2563: return sshbuf_froms(ssh->state->incoming_packet, valp);
1.201 markus 2564: }
2565:
1.211 djm 2566: #ifdef WITH_OPENSSL
1.201 markus 2567: int
2568: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2569: {
2570: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2571: }
2572:
2573: int
1.281 djm 2574: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM **valp)
1.201 markus 2575: {
1.281 djm 2576: return sshbuf_get_bignum2(ssh->state->incoming_packet, valp);
1.201 markus 2577: }
1.211 djm 2578: #endif /* WITH_OPENSSL */
1.201 markus 2579:
2580: int
2581: sshpkt_get_end(struct ssh *ssh)
2582: {
2583: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2584: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2585: return 0;
2586: }
2587:
2588: const u_char *
2589: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2590: {
2591: if (lenp != NULL)
2592: *lenp = sshbuf_len(ssh->state->incoming_packet);
2593: return sshbuf_ptr(ssh->state->incoming_packet);
2594: }
2595:
2596: /* start a new packet */
2597:
2598: int
2599: sshpkt_start(struct ssh *ssh, u_char type)
2600: {
1.249 djm 2601: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2602:
2603: DBG(debug("packet_start[%d]", type));
1.249 djm 2604: memset(buf, 0, sizeof(buf));
2605: buf[sizeof(buf) - 1] = type;
1.201 markus 2606: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2607: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2608: }
2609:
1.242 markus 2610: static int
2611: ssh_packet_send_mux(struct ssh *ssh)
2612: {
2613: struct session_state *state = ssh->state;
2614: u_char type, *cp;
2615: size_t len;
2616: int r;
2617:
2618: if (ssh->kex)
2619: return SSH_ERR_INTERNAL_ERROR;
2620: len = sshbuf_len(state->outgoing_packet);
2621: if (len < 6)
2622: return SSH_ERR_INTERNAL_ERROR;
2623: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2624: type = cp[5];
2625: if (ssh_packet_log_type(type))
2626: debug3("%s: type %u", __func__, type);
2627: /* drop everything, but the connection protocol */
2628: if (type >= SSH2_MSG_CONNECTION_MIN &&
2629: type <= SSH2_MSG_CONNECTION_MAX) {
2630: POKE_U32(cp, len - 4);
2631: if ((r = sshbuf_putb(state->output,
2632: state->outgoing_packet)) != 0)
2633: return r;
2634: /* sshbuf_dump(state->output, stderr); */
2635: }
2636: sshbuf_reset(state->outgoing_packet);
1.264 djm 2637: return 0;
2638: }
2639:
2640: /*
2641: * 9.2. Ignored Data Message
2642: *
2643: * byte SSH_MSG_IGNORE
2644: * string data
2645: *
2646: * All implementations MUST understand (and ignore) this message at any
2647: * time (after receiving the protocol version). No implementation is
2648: * required to send them. This message can be used as an additional
2649: * protection measure against advanced traffic analysis techniques.
2650: */
2651: int
2652: sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2653: {
2654: u_int32_t rnd = 0;
2655: int r;
2656: u_int i;
2657:
2658: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2659: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2660: return r;
2661: for (i = 0; i < nbytes; i++) {
2662: if (i % 4 == 0)
2663: rnd = arc4random();
2664: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2665: return r;
2666: rnd >>= 8;
2667: }
1.242 markus 2668: return 0;
2669: }
2670:
1.201 markus 2671: /* send it */
2672:
2673: int
2674: sshpkt_send(struct ssh *ssh)
2675: {
1.242 markus 2676: if (ssh->state && ssh->state->mux)
2677: return ssh_packet_send_mux(ssh);
1.249 djm 2678: return ssh_packet_send2(ssh);
1.201 markus 2679: }
2680:
2681: int
2682: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2683: {
2684: char buf[1024];
2685: va_list args;
2686: int r;
2687:
2688: va_start(args, fmt);
2689: vsnprintf(buf, sizeof(buf), fmt, args);
2690: va_end(args);
2691:
1.249 djm 2692: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2693: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2694: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2695: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2696: (r = sshpkt_send(ssh)) != 0)
2697: return r;
1.201 markus 2698: return 0;
2699: }
2700:
2701: /* roundup current message to pad bytes */
2702: int
2703: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2704: {
2705: ssh->state->extra_pad = pad;
2706: return 0;
1.1 deraadt 2707: }
![[BACK]](/icons/back.gif){kind=icon}
Return to packet.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh