Annotation of src/usr.bin/ssh/packet.c, Revision 1.281
1.281 ! djm 1: /* $OpenBSD: packet.c,v 1.280 2019/01/19 21:33:14 djm Exp $ */
1.1 deraadt 2: /*
1.15 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.35 deraadt 6: * This file contains code implementing the packet protocol and communication
7: * with the other side. This same code is used both on client and server side.
1.29 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
1.29 markus 14: *
1.25 markus 15: *
16: * SSH2 packet format added by Markus Friedl.
1.69 markus 17: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.25 markus 18: *
1.35 deraadt 19: * Redistribution and use in source and binary forms, with or without
20: * modification, are permitted provided that the following conditions
21: * are met:
22: * 1. Redistributions of source code must retain the above copyright
23: * notice, this list of conditions and the following disclaimer.
24: * 2. Redistributions in binary form must reproduce the above copyright
25: * notice, this list of conditions and the following disclaimer in the
26: * documentation and/or other materials provided with the distribution.
27: *
28: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15 deraadt 38: */
1.1 deraadt 39:
1.142 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:
1.201 markus 59: #include <zlib.h>
60:
1.1 deraadt 61: #include "xmalloc.h"
62: #include "crc32.h"
1.25 markus 63: #include "compat.h"
64: #include "ssh2.h"
1.37 markus 65: #include "cipher.h"
1.201 markus 66: #include "sshkey.h"
1.25 markus 67: #include "kex.h"
1.200 markus 68: #include "digest.h"
1.50 markus 69: #include "mac.h"
1.46 markus 70: #include "log.h"
71: #include "canohost.h"
1.87 stevesk 72: #include "misc.h"
1.198 millert 73: #include "channels.h"
1.95 markus 74: #include "ssh.h"
1.201 markus 75: #include "packet.h"
1.197 djm 76: #include "ssherr.h"
1.201 markus 77: #include "sshbuf.h"
1.25 markus 78:
79: #ifdef PACKET_DEBUG
80: #define DBG(x) x
81: #else
82: #define DBG(x)
83: #endif
84:
1.159 markus 85: #define PACKET_MAX_SIZE (256 * 1024)
86:
1.161 andreas 87: struct packet_state {
88: u_int32_t seqnr;
89: u_int32_t packets;
90: u_int64_t blocks;
91: u_int64_t bytes;
92: };
93:
94: struct packet {
95: TAILQ_ENTRY(packet) next;
96: u_char type;
1.201 markus 97: struct sshbuf *payload;
1.161 andreas 98: };
99:
100: struct session_state {
101: /*
102: * This variable contains the file descriptors used for
103: * communicating with the other side. connection_in is used for
104: * reading; connection_out for writing. These can be the same
105: * descriptor, in which case it is assumed to be a socket.
106: */
107: int connection_in;
108: int connection_out;
109:
110: /* Protocol flags for the remote side. */
111: u_int remote_protocol_flags;
1.1 deraadt 112:
1.161 andreas 113: /* Encryption context for receiving data. Only used for decryption. */
1.235 djm 114: struct sshcipher_ctx *receive_context;
1.1 deraadt 115:
1.161 andreas 116: /* Encryption context for sending data. Only used for encryption. */
1.235 djm 117: struct sshcipher_ctx *send_context;
1.14 markus 118:
1.161 andreas 119: /* Buffer for raw input data from the socket. */
1.201 markus 120: struct sshbuf *input;
1.1 deraadt 121:
1.161 andreas 122: /* Buffer for raw output data going to the socket. */
1.201 markus 123: struct sshbuf *output;
1.1 deraadt 124:
1.161 andreas 125: /* Buffer for the partial outgoing packet being constructed. */
1.201 markus 126: struct sshbuf *outgoing_packet;
1.1 deraadt 127:
1.161 andreas 128: /* Buffer for the incoming packet currently being processed. */
1.201 markus 129: struct sshbuf *incoming_packet;
1.1 deraadt 130:
1.161 andreas 131: /* Scratch buffer for packet compression/decompression. */
1.201 markus 132: struct sshbuf *compression_buffer;
133:
134: /* Incoming/outgoing compression dictionaries */
135: z_stream compression_in_stream;
136: z_stream compression_out_stream;
137: int compression_in_started;
138: int compression_out_started;
139: int compression_in_failures;
140: int compression_out_failures;
1.1 deraadt 141:
1.161 andreas 142: /* default maximum packet size */
143: u_int max_packet_size;
1.1 deraadt 144:
1.161 andreas 145: /* Flag indicating whether this module has been initialized. */
146: int initialized;
1.12 markus 147:
1.161 andreas 148: /* Set to true if the connection is interactive. */
149: int interactive_mode;
1.1 deraadt 150:
1.161 andreas 151: /* Set to true if we are the server side. */
152: int server_side;
1.1 deraadt 153:
1.161 andreas 154: /* Set to true if we are authenticated. */
155: int after_authentication;
1.118 markus 156:
1.161 andreas 157: int keep_alive_timeouts;
1.118 markus 158:
1.161 andreas 159: /* The maximum time that we will wait to send or receive a packet */
160: int packet_timeout_ms;
1.151 dtucker 161:
1.161 andreas 162: /* Session key information for Encryption and MAC */
1.201 markus 163: struct newkeys *newkeys[MODE_MAX];
1.161 andreas 164: struct packet_state p_read, p_send;
1.154 dtucker 165:
1.184 dtucker 166: /* Volume-based rekeying */
1.224 dtucker 167: u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
1.105 markus 168:
1.184 dtucker 169: /* Time-based rekeying */
1.208 markus 170: u_int32_t rekey_interval; /* how often in seconds */
1.184 dtucker 171: time_t rekey_time; /* time of last rekeying */
172:
1.161 andreas 173: /* roundup current message to extra_pad bytes */
174: u_char extra_pad;
1.95 markus 175:
1.161 andreas 176: /* XXX discard incoming data after MAC error */
177: u_int packet_discard;
1.234 markus 178: size_t packet_discard_mac_already;
1.201 markus 179: struct sshmac *packet_discard_mac;
1.71 markus 180:
1.161 andreas 181: /* Used in packet_read_poll2() */
182: u_int packlen;
1.159 markus 183:
1.165 andreas 184: /* Used in packet_send2 */
185: int rekeying;
186:
1.242 markus 187: /* Used in ssh_packet_send_mux() */
188: int mux;
189:
1.165 andreas 190: /* Used in packet_set_interactive */
191: int set_interactive_called;
192:
193: /* Used in packet_set_maxsize */
194: int set_maxsize_called;
195:
1.201 markus 196: /* One-off warning about weak ciphers */
197: int cipher_warning_done;
198:
1.243 djm 199: /* Hook for fuzzing inbound packets */
200: ssh_packet_hook_fn *hook_in;
201: void *hook_in_ctx;
202:
1.161 andreas 203: TAILQ_HEAD(, packet) outgoing;
1.105 markus 204: };
1.161 andreas 205:
1.201 markus 206: struct ssh *
207: ssh_alloc_session_state(void)
1.161 andreas 208: {
1.201 markus 209: struct ssh *ssh = NULL;
210: struct session_state *state = NULL;
1.161 andreas 211:
1.201 markus 212: if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
213: (state = calloc(1, sizeof(*state))) == NULL ||
1.278 djm 214: (ssh->kex = kex_new()) == NULL ||
1.201 markus 215: (state->input = sshbuf_new()) == NULL ||
216: (state->output = sshbuf_new()) == NULL ||
217: (state->outgoing_packet = sshbuf_new()) == NULL ||
218: (state->incoming_packet = sshbuf_new()) == NULL)
219: goto fail;
220: TAILQ_INIT(&state->outgoing);
1.202 markus 221: TAILQ_INIT(&ssh->private_keys);
222: TAILQ_INIT(&ssh->public_keys);
1.201 markus 223: state->connection_in = -1;
224: state->connection_out = -1;
225: state->max_packet_size = 32768;
226: state->packet_timeout_ms = -1;
227: state->p_send.packets = state->p_read.packets = 0;
228: state->initialized = 1;
229: /*
230: * ssh_packet_send2() needs to queue packets until
231: * we've done the initial key exchange.
232: */
233: state->rekeying = 1;
234: ssh->state = state;
235: return ssh;
236: fail:
1.278 djm 237: if (ssh) {
238: kex_free(ssh->kex);
239: free(ssh);
240: }
1.201 markus 241: if (state) {
242: sshbuf_free(state->input);
243: sshbuf_free(state->output);
244: sshbuf_free(state->incoming_packet);
245: sshbuf_free(state->outgoing_packet);
246: free(state);
247: }
248: return NULL;
1.161 andreas 249: }
1.105 markus 250:
1.243 djm 251: void
252: ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
253: {
254: ssh->state->hook_in = hook;
255: ssh->state->hook_in_ctx = ctx;
256: }
257:
1.228 djm 258: /* Returns nonzero if rekeying is in progress */
259: int
260: ssh_packet_is_rekeying(struct ssh *ssh)
261: {
1.278 djm 262: return ssh->state->rekeying || ssh->kex->done == 0;
1.228 djm 263: }
264:
1.16 markus 265: /*
1.253 naddy 266: * Sets the descriptors used for communication.
1.16 markus 267: */
1.201 markus 268: struct ssh *
269: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1 deraadt 270: {
1.201 markus 271: struct session_state *state;
272: const struct sshcipher *none = cipher_by_name("none");
1.197 djm 273: int r;
1.97 deraadt 274:
1.205 djm 275: if (none == NULL) {
276: error("%s: cannot load cipher 'none'", __func__);
277: return NULL;
278: }
1.201 markus 279: if (ssh == NULL)
280: ssh = ssh_alloc_session_state();
1.205 djm 281: if (ssh == NULL) {
282: error("%s: cound not allocate state", __func__);
283: return NULL;
284: }
1.201 markus 285: state = ssh->state;
286: state->connection_in = fd_in;
287: state->connection_out = fd_out;
288: if ((r = cipher_init(&state->send_context, none,
1.197 djm 289: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201 markus 290: (r = cipher_init(&state->receive_context, none,
1.205 djm 291: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
292: error("%s: cipher_init failed: %s", __func__, ssh_err(r));
1.230 djm 293: free(ssh); /* XXX need ssh_free_session_state? */
1.205 djm 294: return NULL;
295: }
1.201 markus 296: state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
1.207 djm 297: /*
298: * Cache the IP address of the remote connection for use in error
299: * messages that might be generated after the connection has closed.
300: */
301: (void)ssh_remote_ipaddr(ssh);
1.201 markus 302: return ssh;
1.1 deraadt 303: }
304:
1.154 dtucker 305: void
1.201 markus 306: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 307: {
1.201 markus 308: struct session_state *state = ssh->state;
309:
1.174 djm 310: if (timeout <= 0 || count <= 0) {
1.201 markus 311: state->packet_timeout_ms = -1;
1.154 dtucker 312: return;
313: }
314: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 315: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 316: else
1.201 markus 317: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 318: }
319:
1.242 markus 320: void
321: ssh_packet_set_mux(struct ssh *ssh)
322: {
323: ssh->state->mux = 1;
324: ssh->state->rekeying = 0;
325: }
326:
327: int
328: ssh_packet_get_mux(struct ssh *ssh)
329: {
330: return ssh->state->mux;
331: }
332:
1.201 markus 333: int
1.245 djm 334: ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
335: {
336: va_list args;
337: int r;
338:
339: free(ssh->log_preamble);
340: if (fmt == NULL)
341: ssh->log_preamble = NULL;
342: else {
343: va_start(args, fmt);
344: r = vasprintf(&ssh->log_preamble, fmt, args);
345: va_end(args);
346: if (r < 0 || ssh->log_preamble == NULL)
347: return SSH_ERR_ALLOC_FAIL;
348: }
349: return 0;
350: }
351:
352: int
1.201 markus 353: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 354: {
1.201 markus 355: struct session_state *state = ssh->state;
356: int r;
357:
358: if (state->packet_discard_mac) {
1.159 markus 359: char buf[1024];
1.234 markus 360: size_t dlen = PACKET_MAX_SIZE;
1.201 markus 361:
1.234 markus 362: if (dlen > state->packet_discard_mac_already)
363: dlen -= state->packet_discard_mac_already;
1.159 markus 364: memset(buf, 'a', sizeof(buf));
1.234 markus 365: while (sshbuf_len(state->incoming_packet) < dlen)
1.201 markus 366: if ((r = sshbuf_put(state->incoming_packet, buf,
367: sizeof(buf))) != 0)
368: return r;
369: (void) mac_compute(state->packet_discard_mac,
370: state->p_read.seqnr,
1.234 markus 371: sshbuf_ptr(state->incoming_packet), dlen,
1.201 markus 372: NULL, 0);
1.159 markus 373: }
1.220 djm 374: logit("Finished discarding for %.200s port %d",
375: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 376: return SSH_ERR_MAC_INVALID;
1.159 markus 377: }
378:
1.201 markus 379: static int
380: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
1.234 markus 381: struct sshmac *mac, size_t mac_already, u_int discard)
1.159 markus 382: {
1.201 markus 383: struct session_state *state = ssh->state;
384: int r;
385:
386: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
387: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
388: return r;
389: return SSH_ERR_MAC_INVALID;
390: }
1.234 markus 391: /*
392: * Record number of bytes over which the mac has already
393: * been computed in order to minimize timing attacks.
394: */
395: if (mac && mac->enabled) {
1.201 markus 396: state->packet_discard_mac = mac;
1.234 markus 397: state->packet_discard_mac_already = mac_already;
398: }
399: if (sshbuf_len(state->input) >= discard)
400: return ssh_packet_stop_discard(ssh);
1.201 markus 401: state->packet_discard = discard - sshbuf_len(state->input);
402: return 0;
1.159 markus 403: }
404:
1.19 markus 405: /* Returns 1 if remote host is connected via socket, 0 if not. */
406:
407: int
1.201 markus 408: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 409: {
1.271 djm 410: struct session_state *state;
1.19 markus 411: struct sockaddr_storage from, to;
412: socklen_t fromlen, tolen;
413:
1.271 djm 414: if (ssh == NULL || ssh->state == NULL)
415: return 0;
416:
417: state = ssh->state;
1.230 djm 418: if (state->connection_in == -1 || state->connection_out == -1)
419: return 0;
1.19 markus 420: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 421: if (state->connection_in == state->connection_out)
1.19 markus 422: return 1;
423: fromlen = sizeof(from);
424: memset(&from, 0, sizeof(from));
1.201 markus 425: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.161 andreas 426: &fromlen) < 0)
1.19 markus 427: return 0;
428: tolen = sizeof(to);
429: memset(&to, 0, sizeof(to));
1.201 markus 430: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.161 andreas 431: &tolen) < 0)
1.19 markus 432: return 0;
433: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
434: return 0;
435: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
436: return 0;
437: return 1;
438: }
439:
1.91 markus 440: void
1.201 markus 441: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 442: {
1.201 markus 443: if (ibytes)
444: *ibytes = ssh->state->p_read.bytes;
445: if (obytes)
446: *obytes = ssh->state->p_send.bytes;
1.91 markus 447: }
1.125 deraadt 448:
1.91 markus 449: int
1.201 markus 450: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 451: {
452: struct sockaddr_storage to;
1.21 deraadt 453: socklen_t tolen = sizeof(to);
1.19 markus 454:
455: memset(&to, 0, sizeof(to));
1.201 markus 456: if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
1.161 andreas 457: &tolen) < 0)
1.19 markus 458: return 0;
1.173 djm 459: return to.ss_family;
1.19 markus 460: }
461:
1.1 deraadt 462: /* Sets the connection into non-blocking mode. */
463:
1.2 provos 464: void
1.201 markus 465: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 466: {
1.14 markus 467: /* Set the socket into non-blocking mode. */
1.201 markus 468: set_nonblock(ssh->state->connection_in);
1.14 markus 469:
1.201 markus 470: if (ssh->state->connection_out != ssh->state->connection_in)
471: set_nonblock(ssh->state->connection_out);
1.1 deraadt 472: }
473:
474: /* Returns the socket used for reading. */
475:
1.2 provos 476: int
1.201 markus 477: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 478: {
1.201 markus 479: return ssh->state->connection_in;
1.1 deraadt 480: }
481:
482: /* Returns the descriptor used for writing. */
483:
1.2 provos 484: int
1.201 markus 485: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 486: {
1.201 markus 487: return ssh->state->connection_out;
488: }
489:
490: /*
491: * Returns the IP-address of the remote host as a string. The returned
492: * string must not be freed.
493: */
494:
495: const char *
496: ssh_remote_ipaddr(struct ssh *ssh)
497: {
1.271 djm 498: int sock;
1.220 djm 499:
1.201 markus 500: /* Check whether we have cached the ipaddr. */
1.220 djm 501: if (ssh->remote_ipaddr == NULL) {
502: if (ssh_packet_connection_is_on_socket(ssh)) {
1.271 djm 503: sock = ssh->state->connection_in;
1.220 djm 504: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 djm 505: ssh->remote_port = get_peer_port(sock);
506: ssh->local_ipaddr = get_local_ipaddr(sock);
507: ssh->local_port = get_local_port(sock);
1.220 djm 508: } else {
509: ssh->remote_ipaddr = strdup("UNKNOWN");
1.230 djm 510: ssh->remote_port = 65535;
511: ssh->local_ipaddr = strdup("UNKNOWN");
512: ssh->local_port = 65535;
1.220 djm 513: }
514: }
1.201 markus 515: return ssh->remote_ipaddr;
1.1 deraadt 516: }
517:
1.220 djm 518: /* Returns the port number of the remote host. */
519:
520: int
521: ssh_remote_port(struct ssh *ssh)
522: {
523: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
524: return ssh->remote_port;
1.230 djm 525: }
526:
527: /*
528: * Returns the IP-address of the local host as a string. The returned
529: * string must not be freed.
530: */
531:
532: const char *
533: ssh_local_ipaddr(struct ssh *ssh)
534: {
535: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
536: return ssh->local_ipaddr;
537: }
538:
539: /* Returns the port number of the local host. */
540:
541: int
542: ssh_local_port(struct ssh *ssh)
543: {
544: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
545: return ssh->local_port;
1.266 djm 546: }
547:
548: /* Returns the routing domain of the input socket, or NULL if unavailable */
549: const char *
550: ssh_packet_rdomain_in(struct ssh *ssh)
551: {
552: if (ssh->rdomain_in != NULL)
553: return ssh->rdomain_in;
554: if (!ssh_packet_connection_is_on_socket(ssh))
555: return NULL;
556: ssh->rdomain_in = get_rdomain(ssh->state->connection_in);
557: return ssh->rdomain_in;
1.220 djm 558: }
559:
1.1 deraadt 560: /* Closes the connection and clears and frees internal data structures. */
561:
1.257 markus 562: static void
563: ssh_packet_close_internal(struct ssh *ssh, int do_close)
1.1 deraadt 564: {
1.201 markus 565: struct session_state *state = ssh->state;
566: u_int mode;
567:
568: if (!state->initialized)
1.14 markus 569: return;
1.201 markus 570: state->initialized = 0;
1.257 markus 571: if (do_close) {
572: if (state->connection_in == state->connection_out) {
573: close(state->connection_out);
574: } else {
575: close(state->connection_in);
576: close(state->connection_out);
577: }
1.14 markus 578: }
1.201 markus 579: sshbuf_free(state->input);
580: sshbuf_free(state->output);
581: sshbuf_free(state->outgoing_packet);
582: sshbuf_free(state->incoming_packet);
1.257 markus 583: for (mode = 0; mode < MODE_MAX; mode++) {
584: kex_free_newkeys(state->newkeys[mode]); /* current keys */
585: state->newkeys[mode] = NULL;
586: ssh_clear_newkeys(ssh, mode); /* next keys */
587: }
588: /* comression state is in shared mem, so we can only release it once */
589: if (do_close && state->compression_buffer) {
1.201 markus 590: sshbuf_free(state->compression_buffer);
591: if (state->compression_out_started) {
592: z_streamp stream = &state->compression_out_stream;
593: debug("compress outgoing: "
594: "raw data %llu, compressed %llu, factor %.2f",
595: (unsigned long long)stream->total_in,
596: (unsigned long long)stream->total_out,
597: stream->total_in == 0 ? 0.0 :
598: (double) stream->total_out / stream->total_in);
599: if (state->compression_out_failures == 0)
600: deflateEnd(stream);
601: }
602: if (state->compression_in_started) {
1.260 dtucker 603: z_streamp stream = &state->compression_in_stream;
1.201 markus 604: debug("compress incoming: "
605: "raw data %llu, compressed %llu, factor %.2f",
606: (unsigned long long)stream->total_out,
607: (unsigned long long)stream->total_in,
608: stream->total_out == 0 ? 0.0 :
609: (double) stream->total_in / stream->total_out);
610: if (state->compression_in_failures == 0)
611: inflateEnd(stream);
612: }
1.14 markus 613: }
1.235 djm 614: cipher_free(state->send_context);
615: cipher_free(state->receive_context);
616: state->send_context = state->receive_context = NULL;
1.257 markus 617: if (do_close) {
1.277 djm 618: free(ssh->local_ipaddr);
619: ssh->local_ipaddr = NULL;
1.257 markus 620: free(ssh->remote_ipaddr);
621: ssh->remote_ipaddr = NULL;
622: free(ssh->state);
623: ssh->state = NULL;
624: }
625: }
626:
627: void
628: ssh_packet_close(struct ssh *ssh)
629: {
630: ssh_packet_close_internal(ssh, 1);
631: }
632:
633: void
634: ssh_packet_clear_keys(struct ssh *ssh)
635: {
636: ssh_packet_close_internal(ssh, 0);
1.1 deraadt 637: }
638:
639: /* Sets remote side protocol flags. */
640:
1.2 provos 641: void
1.201 markus 642: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 643: {
1.201 markus 644: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 645: }
646:
647: /* Returns the remote protocol flags set earlier by the above function. */
648:
1.40 markus 649: u_int
1.201 markus 650: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 651: {
1.201 markus 652: return ssh->state->remote_protocol_flags;
1.1 deraadt 653: }
654:
1.16 markus 655: /*
656: * Starts packet compression from the next packet on in both directions.
657: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
658: */
1.1 deraadt 659:
1.201 markus 660: static int
661: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 662: {
1.201 markus 663: if (!ssh->state->compression_buffer &&
664: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
665: return SSH_ERR_ALLOC_FAIL;
666: return 0;
1.60 markus 667: }
668:
1.201 markus 669: static int
670: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 671: {
1.201 markus 672: if (level < 1 || level > 9)
673: return SSH_ERR_INVALID_ARGUMENT;
674: debug("Enabling compression at level %d.", level);
675: if (ssh->state->compression_out_started == 1)
676: deflateEnd(&ssh->state->compression_out_stream);
677: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
678: case Z_OK:
679: ssh->state->compression_out_started = 1;
680: break;
681: case Z_MEM_ERROR:
682: return SSH_ERR_ALLOC_FAIL;
683: default:
684: return SSH_ERR_INTERNAL_ERROR;
685: }
686: return 0;
1.1 deraadt 687: }
688:
1.201 markus 689: static int
690: start_compression_in(struct ssh *ssh)
691: {
692: if (ssh->state->compression_in_started == 1)
693: inflateEnd(&ssh->state->compression_in_stream);
694: switch (inflateInit(&ssh->state->compression_in_stream)) {
695: case Z_OK:
696: ssh->state->compression_in_started = 1;
697: break;
698: case Z_MEM_ERROR:
699: return SSH_ERR_ALLOC_FAIL;
700: default:
701: return SSH_ERR_INTERNAL_ERROR;
702: }
703: return 0;
1.95 markus 704: }
705:
1.201 markus 706: /* XXX remove need for separate compression buffer */
707: static int
708: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 709: {
1.201 markus 710: u_char buf[4096];
711: int r, status;
712:
713: if (ssh->state->compression_out_started != 1)
714: return SSH_ERR_INTERNAL_ERROR;
715:
716: /* This case is not handled below. */
717: if (sshbuf_len(in) == 0)
718: return 0;
719:
720: /* Input is the contents of the input buffer. */
721: if ((ssh->state->compression_out_stream.next_in =
722: sshbuf_mutable_ptr(in)) == NULL)
723: return SSH_ERR_INTERNAL_ERROR;
724: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
725:
726: /* Loop compressing until deflate() returns with avail_out != 0. */
727: do {
728: /* Set up fixed-size output buffer. */
729: ssh->state->compression_out_stream.next_out = buf;
730: ssh->state->compression_out_stream.avail_out = sizeof(buf);
731:
732: /* Compress as much data into the buffer as possible. */
733: status = deflate(&ssh->state->compression_out_stream,
734: Z_PARTIAL_FLUSH);
735: switch (status) {
736: case Z_MEM_ERROR:
737: return SSH_ERR_ALLOC_FAIL;
738: case Z_OK:
739: /* Append compressed data to output_buffer. */
740: if ((r = sshbuf_put(out, buf, sizeof(buf) -
741: ssh->state->compression_out_stream.avail_out)) != 0)
742: return r;
743: break;
744: case Z_STREAM_ERROR:
745: default:
746: ssh->state->compression_out_failures++;
747: return SSH_ERR_INVALID_FORMAT;
748: }
749: } while (ssh->state->compression_out_stream.avail_out == 0);
750: return 0;
1.1 deraadt 751: }
752:
1.201 markus 753: static int
754: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 755: {
1.201 markus 756: u_char buf[4096];
757: int r, status;
1.1 deraadt 758:
1.201 markus 759: if (ssh->state->compression_in_started != 1)
760: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 761:
1.201 markus 762: if ((ssh->state->compression_in_stream.next_in =
763: sshbuf_mutable_ptr(in)) == NULL)
764: return SSH_ERR_INTERNAL_ERROR;
765: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 766:
1.201 markus 767: for (;;) {
768: /* Set up fixed-size output buffer. */
769: ssh->state->compression_in_stream.next_out = buf;
770: ssh->state->compression_in_stream.avail_out = sizeof(buf);
771:
772: status = inflate(&ssh->state->compression_in_stream,
773: Z_PARTIAL_FLUSH);
774: switch (status) {
775: case Z_OK:
776: if ((r = sshbuf_put(out, buf, sizeof(buf) -
777: ssh->state->compression_in_stream.avail_out)) != 0)
778: return r;
779: break;
780: case Z_BUF_ERROR:
781: /*
782: * Comments in zlib.h say that we should keep calling
783: * inflate() until we get an error. This appears to
784: * be the error that we get.
785: */
786: return 0;
787: case Z_DATA_ERROR:
788: return SSH_ERR_INVALID_FORMAT;
789: case Z_MEM_ERROR:
790: return SSH_ERR_ALLOC_FAIL;
791: case Z_STREAM_ERROR:
792: default:
793: ssh->state->compression_in_failures++;
794: return SSH_ERR_INTERNAL_ERROR;
795: }
796: }
797: /* NOTREACHED */
1.170 djm 798: }
799:
1.257 markus 800: void
801: ssh_clear_newkeys(struct ssh *ssh, int mode)
802: {
1.259 djm 803: if (ssh->kex && ssh->kex->newkeys[mode]) {
1.257 markus 804: kex_free_newkeys(ssh->kex->newkeys[mode]);
805: ssh->kex->newkeys[mode] = NULL;
806: }
807: }
808:
1.201 markus 809: int
810: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 811: {
1.201 markus 812: struct session_state *state = ssh->state;
813: struct sshenc *enc;
814: struct sshmac *mac;
815: struct sshcomp *comp;
1.235 djm 816: struct sshcipher_ctx **ccp;
1.236 markus 817: struct packet_state *ps;
1.105 markus 818: u_int64_t *max_blocks;
1.259 djm 819: const char *wmsg;
1.197 djm 820: int r, crypt_type;
1.57 markus 821:
1.100 markus 822: debug2("set_newkeys: mode %d", mode);
1.57 markus 823:
1.88 markus 824: if (mode == MODE_OUT) {
1.235 djm 825: ccp = &state->send_context;
1.115 avsm 826: crypt_type = CIPHER_ENCRYPT;
1.236 markus 827: ps = &state->p_send;
1.201 markus 828: max_blocks = &state->max_blocks_out;
1.88 markus 829: } else {
1.235 djm 830: ccp = &state->receive_context;
1.115 avsm 831: crypt_type = CIPHER_DECRYPT;
1.236 markus 832: ps = &state->p_read;
1.201 markus 833: max_blocks = &state->max_blocks_in;
1.88 markus 834: }
1.201 markus 835: if (state->newkeys[mode] != NULL) {
1.257 markus 836: debug("set_newkeys: rekeying, input %llu bytes %llu blocks, "
837: "output %llu bytes %llu blocks",
838: (unsigned long long)state->p_read.bytes,
839: (unsigned long long)state->p_read.blocks,
840: (unsigned long long)state->p_send.bytes,
841: (unsigned long long)state->p_send.blocks);
842: kex_free_newkeys(state->newkeys[mode]);
843: state->newkeys[mode] = NULL;
1.57 markus 844: }
1.236 markus 845: /* note that both bytes and the seqnr are not reset */
846: ps->packets = ps->blocks = 0;
1.201 markus 847: /* move newkeys from kex to state */
848: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
849: return SSH_ERR_INTERNAL_ERROR;
850: ssh->kex->newkeys[mode] = NULL;
851: enc = &state->newkeys[mode]->enc;
852: mac = &state->newkeys[mode]->mac;
853: comp = &state->newkeys[mode]->comp;
854: if (cipher_authlen(enc->cipher) == 0) {
855: if ((r = mac_init(mac)) != 0)
856: return r;
857: }
858: mac->enabled = 1;
1.57 markus 859: DBG(debug("cipher_init_context: %d", mode));
1.279 djm 860: cipher_free(*ccp);
861: *ccp = NULL;
1.235 djm 862: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 863: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 864: return r;
865: if (!state->cipher_warning_done &&
1.235 djm 866: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 867: error("Warning: %s", wmsg);
868: state->cipher_warning_done = 1;
869: }
1.91 markus 870: /* Deleting the keys does not gain extra security */
1.192 djm 871: /* explicit_bzero(enc->iv, enc->block_size);
872: explicit_bzero(enc->key, enc->key_len);
873: explicit_bzero(mac->key, mac->key_len); */
1.275 sf 874: if ((comp->type == COMP_ZLIB ||
875: (comp->type == COMP_DELAYED &&
876: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 877: if ((r = ssh_packet_init_compression(ssh)) < 0)
878: return r;
879: if (mode == MODE_OUT) {
880: if ((r = start_compression_out(ssh, 6)) != 0)
881: return r;
882: } else {
883: if ((r = start_compression_in(ssh)) != 0)
884: return r;
885: }
1.57 markus 886: comp->enabled = 1;
887: }
1.109 markus 888: /*
889: * The 2^(blocksize*2) limit is too expensive for 3DES,
1.254 djm 890: * so enforce a 1GB limit for small blocksizes.
1.261 dtucker 891: * See RFC4344 section 3.2.
1.109 markus 892: */
893: if (enc->block_size >= 16)
894: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
895: else
896: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 897: if (state->rekey_limit)
1.237 deraadt 898: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 899: state->rekey_limit / enc->block_size);
1.227 djm 900: debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1.201 markus 901: return 0;
1.57 markus 902: }
903:
1.228 djm 904: #define MAX_PACKETS (1U<<31)
905: static int
906: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
907: {
908: struct session_state *state = ssh->state;
909: u_int32_t out_blocks;
910:
911: /* XXX client can't cope with rekeying pre-auth */
912: if (!state->after_authentication)
913: return 0;
914:
915: /* Haven't keyed yet or KEX in progress. */
1.278 djm 916: if (ssh_packet_is_rekeying(ssh))
1.228 djm 917: return 0;
918:
919: /* Peer can't rekey */
920: if (ssh->compat & SSH_BUG_NOREKEY)
921: return 0;
922:
923: /*
924: * Permit one packet in or out per rekey - this allows us to
925: * make progress when rekey limits are very small.
926: */
927: if (state->p_send.packets == 0 && state->p_read.packets == 0)
928: return 0;
929:
930: /* Time-based rekeying */
931: if (state->rekey_interval != 0 &&
1.244 dtucker 932: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 933: return 1;
934:
1.261 dtucker 935: /*
936: * Always rekey when MAX_PACKETS sent in either direction
937: * As per RFC4344 section 3.1 we do this after 2^31 packets.
938: */
1.228 djm 939: if (state->p_send.packets > MAX_PACKETS ||
940: state->p_read.packets > MAX_PACKETS)
941: return 1;
942:
943: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 944: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 945: state->newkeys[MODE_OUT]->enc.block_size);
946: return (state->max_blocks_out &&
947: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
948: (state->max_blocks_in &&
949: (state->p_read.blocks > state->max_blocks_in));
950: }
951:
1.16 markus 952: /*
1.118 markus 953: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 954: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 955: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
956: */
1.201 markus 957: static int
958: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 959: {
1.201 markus 960: struct session_state *state = ssh->state;
961: struct sshcomp *comp = NULL;
962: int r, mode;
1.118 markus 963:
964: /*
965: * Remember that we are past the authentication step, so rekeying
1.275 sf 966: * with COMP_DELAYED will turn on compression immediately.
1.118 markus 967: */
1.201 markus 968: state->after_authentication = 1;
1.118 markus 969: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 970: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 971: if (state->newkeys[mode] == NULL)
1.145 markus 972: continue;
1.201 markus 973: comp = &state->newkeys[mode]->comp;
1.275 sf 974: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 975: if ((r = ssh_packet_init_compression(ssh)) != 0)
976: return r;
977: if (mode == MODE_OUT) {
978: if ((r = start_compression_out(ssh, 6)) != 0)
979: return r;
980: } else {
981: if ((r = start_compression_in(ssh)) != 0)
982: return r;
983: }
1.118 markus 984: comp->enabled = 1;
985: }
986: }
1.201 markus 987: return 0;
1.118 markus 988: }
989:
1.226 djm 990: /* Used to mute debug logging for noisy packet types */
1.242 markus 991: int
1.226 djm 992: ssh_packet_log_type(u_char type)
993: {
994: switch (type) {
995: case SSH2_MSG_CHANNEL_DATA:
996: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
997: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
998: return 0;
999: default:
1000: return 1;
1001: }
1002: }
1003:
1.118 markus 1004: /*
1.25 markus 1005: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1006: */
1.201 markus 1007: int
1008: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1009: {
1.201 markus 1010: struct session_state *state = ssh->state;
1.200 markus 1011: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1012: u_char tmp, padlen, pad = 0;
1.201 markus 1013: u_int authlen = 0, aadlen = 0;
1014: u_int len;
1015: struct sshenc *enc = NULL;
1016: struct sshmac *mac = NULL;
1017: struct sshcomp *comp = NULL;
1018: int r, block_size;
1019:
1020: if (state->newkeys[MODE_OUT] != NULL) {
1021: enc = &state->newkeys[MODE_OUT]->enc;
1022: mac = &state->newkeys[MODE_OUT]->mac;
1023: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1024: /* disable mac for authenticated encryption */
1025: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1026: mac = NULL;
1.25 markus 1027: }
1.88 markus 1028: block_size = enc ? enc->block_size : 8;
1.180 markus 1029: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1030:
1.201 markus 1031: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1032: if (ssh_packet_log_type(type))
1033: debug3("send packet: type %u", type);
1.25 markus 1034: #ifdef PACKET_DEBUG
1035: fprintf(stderr, "plain: ");
1.201 markus 1036: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1037: #endif
1038:
1039: if (comp && comp->enabled) {
1.201 markus 1040: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1041: /* skip header, compress only payload */
1.201 markus 1042: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1043: goto out;
1044: sshbuf_reset(state->compression_buffer);
1045: if ((r = compress_buffer(ssh, state->outgoing_packet,
1046: state->compression_buffer)) != 0)
1047: goto out;
1048: sshbuf_reset(state->outgoing_packet);
1049: if ((r = sshbuf_put(state->outgoing_packet,
1050: "\0\0\0\0\0", 5)) != 0 ||
1051: (r = sshbuf_putb(state->outgoing_packet,
1052: state->compression_buffer)) != 0)
1053: goto out;
1054: DBG(debug("compression: raw %d compressed %zd", len,
1055: sshbuf_len(state->outgoing_packet)));
1.25 markus 1056: }
1057:
1058: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1059: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1060:
1061: /*
1062: * calc size of padding, alloc space, get random data,
1063: * minimum padding is 4 bytes
1064: */
1.178 markus 1065: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1066: padlen = block_size - (len % block_size);
1067: if (padlen < 4)
1068: padlen += block_size;
1.201 markus 1069: if (state->extra_pad) {
1.233 djm 1070: tmp = state->extra_pad;
1.201 markus 1071: state->extra_pad =
1.237 deraadt 1072: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1073: /* check if roundup overflowed */
1074: if (state->extra_pad < tmp)
1075: return SSH_ERR_INVALID_ARGUMENT;
1076: tmp = (len + padlen) % state->extra_pad;
1077: /* Check whether pad calculation below will underflow */
1078: if (tmp > state->extra_pad)
1079: return SSH_ERR_INVALID_ARGUMENT;
1080: pad = state->extra_pad - tmp;
1.193 djm 1081: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1082: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1083: tmp = padlen;
1.71 markus 1084: padlen += pad;
1.233 djm 1085: /* Check whether padlen calculation overflowed */
1086: if (padlen < tmp)
1087: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1088: state->extra_pad = 0;
1.71 markus 1089: }
1.201 markus 1090: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1091: goto out;
1.235 djm 1092: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1093: /* random padding */
1.201 markus 1094: arc4random_buf(cp, padlen);
1.32 markus 1095: } else {
1096: /* clear padding */
1.192 djm 1097: explicit_bzero(cp, padlen);
1.25 markus 1098: }
1.178 markus 1099: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1100: len = sshbuf_len(state->outgoing_packet);
1101: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1102: if (cp == NULL) {
1103: r = SSH_ERR_INTERNAL_ERROR;
1104: goto out;
1105: }
1.25 markus 1106: /* packet_length includes payload, padding and padding length field */
1.201 markus 1107: POKE_U32(cp, len - 4);
1.89 markus 1108: cp[4] = padlen;
1.178 markus 1109: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1110: len, padlen, aadlen));
1.25 markus 1111:
1112: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1113: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1114: if ((r = mac_compute(mac, state->p_send.seqnr,
1115: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1116: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1117: goto out;
1118: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1119: }
1120: /* encrypt packet and append to output buffer. */
1.201 markus 1121: if ((r = sshbuf_reserve(state->output,
1122: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1123: goto out;
1.235 djm 1124: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1125: sshbuf_ptr(state->outgoing_packet),
1126: len - aadlen, aadlen, authlen)) != 0)
1127: goto out;
1.25 markus 1128: /* append unencrypted MAC */
1.178 markus 1129: if (mac && mac->enabled) {
1130: if (mac->etm) {
1131: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1132: if ((r = mac_compute(mac, state->p_send.seqnr,
1133: cp, len, macbuf, sizeof(macbuf))) != 0)
1134: goto out;
1.178 markus 1135: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1136: state->p_send.seqnr));
1.178 markus 1137: }
1.201 markus 1138: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1139: goto out;
1.178 markus 1140: }
1.25 markus 1141: #ifdef PACKET_DEBUG
1142: fprintf(stderr, "encrypted: ");
1.201 markus 1143: sshbuf_dump(state->output, stderr);
1.25 markus 1144: #endif
1.29 markus 1145: /* increment sequence number for outgoing packets */
1.201 markus 1146: if (++state->p_send.seqnr == 0)
1.106 itojun 1147: logit("outgoing seqnr wraps around");
1.201 markus 1148: if (++state->p_send.packets == 0)
1149: if (!(ssh->compat & SSH_BUG_NOREKEY))
1150: return SSH_ERR_NEED_REKEY;
1151: state->p_send.blocks += len / block_size;
1152: state->p_send.bytes += len;
1153: sshbuf_reset(state->outgoing_packet);
1.25 markus 1154:
1.57 markus 1155: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1156: r = ssh_set_newkeys(ssh, MODE_OUT);
1157: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1158: r = ssh_packet_enable_delayed_compress(ssh);
1159: else
1160: r = 0;
1161: out:
1162: return r;
1.25 markus 1163: }
1164:
1.228 djm 1165: /* returns non-zero if the specified packet type is usec by KEX */
1166: static int
1167: ssh_packet_type_is_kex(u_char type)
1168: {
1169: return
1170: type >= SSH2_MSG_TRANSPORT_MIN &&
1171: type <= SSH2_MSG_TRANSPORT_MAX &&
1172: type != SSH2_MSG_SERVICE_REQUEST &&
1173: type != SSH2_MSG_SERVICE_ACCEPT &&
1174: type != SSH2_MSG_EXT_INFO;
1175: }
1176:
1.201 markus 1177: int
1178: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1179: {
1.201 markus 1180: struct session_state *state = ssh->state;
1.105 markus 1181: struct packet *p;
1.201 markus 1182: u_char type;
1.228 djm 1183: int r, need_rekey;
1.105 markus 1184:
1.228 djm 1185: if (sshbuf_len(state->outgoing_packet) < 6)
1186: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1187: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1188: need_rekey = !ssh_packet_type_is_kex(type) &&
1189: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1190:
1.228 djm 1191: /*
1192: * During rekeying we can only send key exchange messages.
1193: * Queue everything else.
1194: */
1195: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1196: if (need_rekey)
1197: debug3("%s: rekex triggered", __func__);
1198: debug("enqueue packet: %u", type);
1199: p = calloc(1, sizeof(*p));
1200: if (p == NULL)
1201: return SSH_ERR_ALLOC_FAIL;
1202: p->type = type;
1203: p->payload = state->outgoing_packet;
1204: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1205: state->outgoing_packet = sshbuf_new();
1206: if (state->outgoing_packet == NULL)
1207: return SSH_ERR_ALLOC_FAIL;
1208: if (need_rekey) {
1209: /*
1210: * This packet triggered a rekey, so send the
1211: * KEXINIT now.
1212: * NB. reenters this function via kex_start_rekex().
1213: */
1214: return kex_start_rekex(ssh);
1.105 markus 1215: }
1.228 djm 1216: return 0;
1.105 markus 1217: }
1218:
1219: /* rekeying starts with sending KEXINIT */
1220: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1221: state->rekeying = 1;
1.105 markus 1222:
1.201 markus 1223: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1224: return r;
1.105 markus 1225:
1226: /* after a NEWKEYS message we can send the complete queue */
1227: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1228: state->rekeying = 0;
1229: state->rekey_time = monotime();
1230: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1231: type = p->type;
1.228 djm 1232: /*
1233: * If this packet triggers a rekex, then skip the
1234: * remaining packets in the queue for now.
1235: * NB. re-enters this function via kex_start_rekex.
1236: */
1237: if (ssh_packet_need_rekeying(ssh,
1238: sshbuf_len(p->payload))) {
1239: debug3("%s: queued packet triggered rekex",
1240: __func__);
1241: return kex_start_rekex(ssh);
1242: }
1.105 markus 1243: debug("dequeue packet: %u", type);
1.201 markus 1244: sshbuf_free(state->outgoing_packet);
1245: state->outgoing_packet = p->payload;
1246: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1247: memset(p, 0, sizeof(*p));
1.186 djm 1248: free(p);
1.201 markus 1249: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1250: return r;
1.105 markus 1251: }
1252: }
1.201 markus 1253: return 0;
1.25 markus 1254: }
1255:
1256: /*
1.16 markus 1257: * Waits until a packet has been received, and returns its type. Note that
1258: * no other data is processed until this returns, so this function should not
1259: * be used during the interactive session.
1260: */
1.1 deraadt 1261:
1.2 provos 1262: int
1.201 markus 1263: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1264: {
1.201 markus 1265: struct session_state *state = ssh->state;
1.222 markus 1266: int len, r, ms_remain;
1.56 millert 1267: fd_set *setp;
1.14 markus 1268: char buf[8192];
1.155 deraadt 1269: struct timeval timeout, start, *timeoutp = NULL;
1270:
1.25 markus 1271: DBG(debug("packet_read()"));
1.14 markus 1272:
1.214 deraadt 1273: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1274: NFDBITS), sizeof(fd_mask));
1.201 markus 1275: if (setp == NULL)
1276: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1277:
1.205 djm 1278: /*
1279: * Since we are blocking, ensure that all written packets have
1280: * been sent.
1281: */
1.210 markus 1282: if ((r = ssh_packet_write_wait(ssh)) != 0)
1283: goto out;
1.14 markus 1284:
1285: /* Stay in the loop until we have received a complete packet. */
1286: for (;;) {
1287: /* Try to read a packet from the buffer. */
1.201 markus 1288: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1289: if (r != 0)
1290: break;
1.14 markus 1291: /* If we got a packet, return it. */
1.201 markus 1292: if (*typep != SSH_MSG_NONE)
1293: break;
1.16 markus 1294: /*
1295: * Otherwise, wait for some data to arrive, add it to the
1296: * buffer, and try again.
1297: */
1.201 markus 1298: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1299: NFDBITS) * sizeof(fd_mask));
1.201 markus 1300: FD_SET(state->connection_in, setp);
1.16 markus 1301:
1.201 markus 1302: if (state->packet_timeout_ms > 0) {
1303: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1304: timeoutp = &timeout;
1305: }
1.14 markus 1306: /* Wait for some data to arrive. */
1.154 dtucker 1307: for (;;) {
1.201 markus 1308: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1309: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1310: monotime_tv(&start);
1.154 dtucker 1311: }
1.201 markus 1312: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1313: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1314: break;
1.270 dtucker 1315: if (errno != EAGAIN && errno != EINTR) {
1316: r = SSH_ERR_SYSTEM_ERROR;
1317: goto out;
1318: }
1.201 markus 1319: if (state->packet_timeout_ms == -1)
1.154 dtucker 1320: continue;
1321: ms_subtract_diff(&start, &ms_remain);
1322: if (ms_remain <= 0) {
1.201 markus 1323: r = 0;
1.154 dtucker 1324: break;
1325: }
1326: }
1.246 djm 1327: if (r == 0) {
1328: r = SSH_ERR_CONN_TIMEOUT;
1329: goto out;
1330: }
1.14 markus 1331: /* Read data from the socket. */
1.222 markus 1332: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1333: if (len == 0) {
1334: r = SSH_ERR_CONN_CLOSED;
1335: goto out;
1336: }
1337: if (len < 0) {
1338: r = SSH_ERR_SYSTEM_ERROR;
1339: goto out;
1340: }
1.204 djm 1341:
1.14 markus 1342: /* Append it to the buffer. */
1.204 djm 1343: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1344: goto out;
1.14 markus 1345: }
1.210 markus 1346: out:
1.201 markus 1347: free(setp);
1348: return r;
1.1 deraadt 1349: }
1350:
1.77 djm 1351: int
1.201 markus 1352: ssh_packet_read(struct ssh *ssh)
1.77 djm 1353: {
1.201 markus 1354: u_char type;
1355: int r;
1356:
1357: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1358: fatal("%s: %s", __func__, ssh_err(r));
1359: return type;
1.77 djm 1360: }
1361:
1.16 markus 1362: /*
1363: * Waits until a packet has been received, verifies that its type matches
1364: * that given, and gives a fatal error and exits if there is a mismatch.
1365: */
1.1 deraadt 1366:
1.205 djm 1367: int
1368: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1369: {
1.205 djm 1370: int r;
1371: u_char type;
1.1 deraadt 1372:
1.205 djm 1373: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1374: return r;
1375: if (type != expected_type) {
1376: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1377: "Protocol error: expected packet type %d, got %d",
1.205 djm 1378: expected_type, type)) != 0)
1379: return r;
1380: return SSH_ERR_PROTOCOL_ERROR;
1381: }
1382: return 0;
1.1 deraadt 1383: }
1.14 markus 1384:
1.242 markus 1385: static int
1386: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1387: {
1388: struct session_state *state = ssh->state;
1389: const u_char *cp;
1390: size_t need;
1391: int r;
1392:
1393: if (ssh->kex)
1394: return SSH_ERR_INTERNAL_ERROR;
1395: *typep = SSH_MSG_NONE;
1396: cp = sshbuf_ptr(state->input);
1397: if (state->packlen == 0) {
1398: if (sshbuf_len(state->input) < 4 + 1)
1399: return 0; /* packet is incomplete */
1400: state->packlen = PEEK_U32(cp);
1401: if (state->packlen < 4 + 1 ||
1402: state->packlen > PACKET_MAX_SIZE)
1403: return SSH_ERR_MESSAGE_INCOMPLETE;
1404: }
1405: need = state->packlen + 4;
1406: if (sshbuf_len(state->input) < need)
1407: return 0; /* packet is incomplete */
1408: sshbuf_reset(state->incoming_packet);
1409: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1410: state->packlen)) != 0 ||
1411: (r = sshbuf_consume(state->input, need)) != 0 ||
1412: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1413: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1414: return r;
1415: if (ssh_packet_log_type(*typep))
1416: debug3("%s: type %u", __func__, *typep);
1417: /* sshbuf_dump(state->incoming_packet, stderr); */
1418: /* reset for next packet */
1419: state->packlen = 0;
1420: return r;
1421: }
1422:
1.201 markus 1423: int
1424: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1425: {
1.201 markus 1426: struct session_state *state = ssh->state;
1.40 markus 1427: u_int padlen, need;
1.231 djm 1428: u_char *cp;
1.201 markus 1429: u_int maclen, aadlen = 0, authlen = 0, block_size;
1430: struct sshenc *enc = NULL;
1431: struct sshmac *mac = NULL;
1432: struct sshcomp *comp = NULL;
1.200 markus 1433: int r;
1.201 markus 1434:
1.242 markus 1435: if (state->mux)
1436: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1437:
1.201 markus 1438: *typep = SSH_MSG_NONE;
1439:
1440: if (state->packet_discard)
1441: return 0;
1442:
1443: if (state->newkeys[MODE_IN] != NULL) {
1444: enc = &state->newkeys[MODE_IN]->enc;
1445: mac = &state->newkeys[MODE_IN]->mac;
1446: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1447: /* disable mac for authenticated encryption */
1448: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1449: mac = NULL;
1.25 markus 1450: }
1451: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1452: block_size = enc ? enc->block_size : 8;
1.180 markus 1453: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1454:
1.201 markus 1455: if (aadlen && state->packlen == 0) {
1.235 djm 1456: if (cipher_get_length(state->receive_context,
1.201 markus 1457: &state->packlen, state->p_read.seqnr,
1458: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1459: return 0;
1460: if (state->packlen < 1 + 4 ||
1461: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1462: #ifdef PACKET_DEBUG
1.201 markus 1463: sshbuf_dump(state->input, stderr);
1.178 markus 1464: #endif
1.201 markus 1465: logit("Bad packet length %u.", state->packlen);
1466: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1467: return r;
1.217 djm 1468: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1469: }
1.201 markus 1470: sshbuf_reset(state->incoming_packet);
1471: } else if (state->packlen == 0) {
1.25 markus 1472: /*
1473: * check if input size is less than the cipher block size,
1474: * decrypt first block and extract length of incoming packet
1475: */
1.201 markus 1476: if (sshbuf_len(state->input) < block_size)
1477: return 0;
1478: sshbuf_reset(state->incoming_packet);
1479: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1480: &cp)) != 0)
1481: goto out;
1.235 djm 1482: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1483: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1484: block_size, 0, 0)) != 0)
1485: goto out;
1486: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1487: if (state->packlen < 1 + 4 ||
1488: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1489: #ifdef PACKET_DEBUG
1.201 markus 1490: fprintf(stderr, "input: \n");
1491: sshbuf_dump(state->input, stderr);
1492: fprintf(stderr, "incoming_packet: \n");
1493: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1494: #endif
1.201 markus 1495: logit("Bad packet length %u.", state->packlen);
1.234 markus 1496: return ssh_packet_start_discard(ssh, enc, mac, 0,
1497: PACKET_MAX_SIZE);
1.25 markus 1498: }
1.201 markus 1499: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1500: goto out;
1.25 markus 1501: }
1.201 markus 1502: DBG(debug("input: packet len %u", state->packlen+4));
1503:
1.178 markus 1504: if (aadlen) {
1505: /* only the payload is encrypted */
1.201 markus 1506: need = state->packlen;
1.178 markus 1507: } else {
1508: /*
1509: * the payload size and the payload are encrypted, but we
1510: * have a partial packet of block_size bytes
1511: */
1.201 markus 1512: need = 4 + state->packlen - block_size;
1.178 markus 1513: }
1.180 markus 1514: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1515: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1516: if (need % block_size != 0) {
1517: logit("padding error: need %d block %d mod %d",
1.25 markus 1518: need, block_size, need % block_size);
1.234 markus 1519: return ssh_packet_start_discard(ssh, enc, mac, 0,
1520: PACKET_MAX_SIZE - block_size);
1.158 markus 1521: }
1.25 markus 1522: /*
1523: * check if the entire packet has been received and
1.178 markus 1524: * decrypt into incoming_packet:
1525: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1526: * 'need' bytes are encrypted, followed by either
1527: * 'authlen' bytes of authentication tag or
1.178 markus 1528: * 'maclen' bytes of message authentication code.
1.25 markus 1529: */
1.201 markus 1530: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1531: return 0; /* packet is incomplete */
1.25 markus 1532: #ifdef PACKET_DEBUG
1533: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1534: sshbuf_dump(state->input, stderr);
1.25 markus 1535: #endif
1.231 djm 1536: /* EtM: check mac over encrypted input */
1.201 markus 1537: if (mac && mac->enabled && mac->etm) {
1.231 djm 1538: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1539: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1540: sshbuf_ptr(state->input) + aadlen + need + authlen,
1541: maclen)) != 0) {
1542: if (r == SSH_ERR_MAC_INVALID)
1543: logit("Corrupted MAC on input.");
1.201 markus 1544: goto out;
1.231 djm 1545: }
1.201 markus 1546: }
1547: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1548: &cp)) != 0)
1549: goto out;
1.235 djm 1550: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1551: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1552: goto out;
1553: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1554: goto out;
1.29 markus 1555: if (mac && mac->enabled) {
1.231 djm 1556: /* Not EtM: check MAC over cleartext */
1557: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1558: sshbuf_ptr(state->incoming_packet),
1559: sshbuf_len(state->incoming_packet),
1560: sshbuf_ptr(state->input), maclen)) != 0) {
1561: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1562: goto out;
1.159 markus 1563: logit("Corrupted MAC on input.");
1.247 markus 1564: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1565: return SSH_ERR_INTERNAL_ERROR;
1566: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1567: sshbuf_len(state->incoming_packet),
1.247 markus 1568: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1569: }
1.231 djm 1570: /* Remove MAC from input buffer */
1.201 markus 1571: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1572: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1573: goto out;
1.25 markus 1574: }
1.77 djm 1575: if (seqnr_p != NULL)
1.201 markus 1576: *seqnr_p = state->p_read.seqnr;
1577: if (++state->p_read.seqnr == 0)
1.106 itojun 1578: logit("incoming seqnr wraps around");
1.201 markus 1579: if (++state->p_read.packets == 0)
1580: if (!(ssh->compat & SSH_BUG_NOREKEY))
1581: return SSH_ERR_NEED_REKEY;
1582: state->p_read.blocks += (state->packlen + 4) / block_size;
1583: state->p_read.bytes += state->packlen + 4;
1.25 markus 1584:
1585: /* get padlen */
1.201 markus 1586: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1587: DBG(debug("input: padlen %d", padlen));
1.205 djm 1588: if (padlen < 4) {
1589: if ((r = sshpkt_disconnect(ssh,
1590: "Corrupted padlen %d on input.", padlen)) != 0 ||
1591: (r = ssh_packet_write_wait(ssh)) != 0)
1592: return r;
1593: return SSH_ERR_CONN_CORRUPT;
1594: }
1.25 markus 1595:
1596: /* skip packet size + padlen, discard padding */
1.201 markus 1597: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1598: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1599: goto out;
1.25 markus 1600:
1.201 markus 1601: DBG(debug("input: len before de-compress %zd",
1602: sshbuf_len(state->incoming_packet)));
1.25 markus 1603: if (comp && comp->enabled) {
1.201 markus 1604: sshbuf_reset(state->compression_buffer);
1605: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1606: state->compression_buffer)) != 0)
1607: goto out;
1608: sshbuf_reset(state->incoming_packet);
1609: if ((r = sshbuf_putb(state->incoming_packet,
1610: state->compression_buffer)) != 0)
1611: goto out;
1612: DBG(debug("input: len after de-compress %zd",
1613: sshbuf_len(state->incoming_packet)));
1.25 markus 1614: }
1615: /*
1616: * get packet type, implies consume.
1617: * return length of payload (without type field)
1618: */
1.201 markus 1619: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1620: goto out;
1.226 djm 1621: if (ssh_packet_log_type(*typep))
1622: debug3("receive packet: type %u", *typep);
1.205 djm 1623: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1624: if ((r = sshpkt_disconnect(ssh,
1625: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1626: (r = ssh_packet_write_wait(ssh)) != 0)
1627: return r;
1628: return SSH_ERR_PROTOCOL_ERROR;
1629: }
1.243 djm 1630: if (state->hook_in != NULL &&
1631: (r = state->hook_in(ssh, state->incoming_packet, typep,
1632: state->hook_in_ctx)) != 0)
1633: return r;
1.238 markus 1634: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1635: r = ssh_packet_enable_delayed_compress(ssh);
1636: else
1637: r = 0;
1.25 markus 1638: #ifdef PACKET_DEBUG
1.201 markus 1639: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1640: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1641: #endif
1.62 markus 1642: /* reset for next packet */
1.201 markus 1643: state->packlen = 0;
1.228 djm 1644:
1645: /* do we need to rekey? */
1646: if (ssh_packet_need_rekeying(ssh, 0)) {
1647: debug3("%s: rekex triggered", __func__);
1648: if ((r = kex_start_rekex(ssh)) != 0)
1649: return r;
1650: }
1.201 markus 1651: out:
1652: return r;
1.25 markus 1653: }
1654:
1655: int
1.201 markus 1656: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1657: {
1.201 markus 1658: struct session_state *state = ssh->state;
1.96 deraadt 1659: u_int reason, seqnr;
1.201 markus 1660: int r;
1661: u_char *msg;
1.62 markus 1662:
1.25 markus 1663: for (;;) {
1.201 markus 1664: msg = NULL;
1.249 djm 1665: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1666: if (r != 0)
1667: return r;
1668: if (*typep) {
1669: state->keep_alive_timeouts = 0;
1670: DBG(debug("received packet type %d", *typep));
1671: }
1672: switch (*typep) {
1673: case SSH2_MSG_IGNORE:
1674: debug3("Received SSH2_MSG_IGNORE");
1675: break;
1676: case SSH2_MSG_DEBUG:
1677: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1678: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1679: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1680: free(msg);
1.201 markus 1681: return r;
1.48 stevesk 1682: }
1.249 djm 1683: debug("Remote: %.900s", msg);
1684: free(msg);
1685: break;
1686: case SSH2_MSG_DISCONNECT:
1687: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1688: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1689: return r;
1690: /* Ignore normal client exit notifications */
1691: do_log2(ssh->state->server_side &&
1692: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1693: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1694: "Received disconnect from %s port %d:"
1695: "%u: %.400s", ssh_remote_ipaddr(ssh),
1696: ssh_remote_port(ssh), reason, msg);
1697: free(msg);
1698: return SSH_ERR_DISCONNECTED;
1699: case SSH2_MSG_UNIMPLEMENTED:
1700: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1701: return r;
1702: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1703: seqnr);
1704: break;
1705: default:
1706: return 0;
1.25 markus 1707: }
1708: }
1709: }
1710:
1.16 markus 1711: /*
1712: * Buffers the given amount of input characters. This is intended to be used
1713: * together with packet_read_poll.
1714: */
1.1 deraadt 1715:
1.204 djm 1716: int
1.201 markus 1717: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1718: {
1.201 markus 1719: struct session_state *state = ssh->state;
1720: int r;
1721:
1722: if (state->packet_discard) {
1723: state->keep_alive_timeouts = 0; /* ?? */
1724: if (len >= state->packet_discard) {
1725: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1726: return r;
1.201 markus 1727: }
1728: state->packet_discard -= len;
1.204 djm 1729: return 0;
1.159 markus 1730: }
1.201 markus 1731: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1732: return r;
1733:
1734: return 0;
1.28 markus 1735: }
1736:
1737: int
1.201 markus 1738: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1739: {
1.201 markus 1740: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1741: }
1742:
1.16 markus 1743: /*
1744: * Sends a diagnostic message from the server to the client. This message
1745: * can be sent at any time (but not while constructing another message). The
1746: * message is printed immediately, but only if the client is being executed
1747: * in verbose mode. These messages are primarily intended to ease debugging
1748: * authentication problems. The length of the formatted message must not
1.205 djm 1749: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1750: */
1.2 provos 1751: void
1.201 markus 1752: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1753: {
1.14 markus 1754: char buf[1024];
1755: va_list args;
1.201 markus 1756: int r;
1.39 markus 1757:
1.249 djm 1758: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1759: return;
1.14 markus 1760:
1761: va_start(args, fmt);
1762: vsnprintf(buf, sizeof(buf), fmt, args);
1763: va_end(args);
1.265 djm 1764:
1765: debug3("sending debug message: %s", buf);
1.14 markus 1766:
1.249 djm 1767: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1768: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1769: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1770: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1771: (r = sshpkt_send(ssh)) != 0 ||
1772: (r = ssh_packet_write_wait(ssh)) != 0)
1.205 djm 1773: fatal("%s: %s", __func__, ssh_err(r));
1774: }
1775:
1.268 dtucker 1776: void
1777: sshpkt_fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1.245 djm 1778: {
1779: snprintf(s, l, "%.200s%s%s port %d",
1780: ssh->log_preamble ? ssh->log_preamble : "",
1781: ssh->log_preamble ? " " : "",
1782: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1783: }
1784:
1.205 djm 1785: /*
1786: * Pretty-print connection-terminating errors and exit.
1787: */
1.280 djm 1788: static void
1789: sshpkt_vfatal(struct ssh *ssh, int r, const char *fmt, va_list ap)
1.205 djm 1790: {
1.280 djm 1791: char *tag = NULL, remote_id[512];
1.245 djm 1792:
1.268 dtucker 1793: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.245 djm 1794:
1.205 djm 1795: switch (r) {
1796: case SSH_ERR_CONN_CLOSED:
1.257 markus 1797: ssh_packet_clear_keys(ssh);
1.245 djm 1798: logdie("Connection closed by %s", remote_id);
1.205 djm 1799: case SSH_ERR_CONN_TIMEOUT:
1.257 markus 1800: ssh_packet_clear_keys(ssh);
1.245 djm 1801: logdie("Connection %s %s timed out",
1802: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1803: case SSH_ERR_DISCONNECTED:
1.257 markus 1804: ssh_packet_clear_keys(ssh);
1.245 djm 1805: logdie("Disconnected from %s", remote_id);
1.212 djm 1806: case SSH_ERR_SYSTEM_ERROR:
1.257 markus 1807: if (errno == ECONNRESET) {
1808: ssh_packet_clear_keys(ssh);
1.245 djm 1809: logdie("Connection reset by %s", remote_id);
1.257 markus 1810: }
1.213 djm 1811: /* FALLTHROUGH */
1812: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1813: case SSH_ERR_NO_MAC_ALG_MATCH:
1814: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1815: case SSH_ERR_NO_KEX_ALG_MATCH:
1816: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1817: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.257 markus 1818: ssh_packet_clear_keys(ssh);
1.245 djm 1819: logdie("Unable to negotiate with %s: %s. "
1820: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1821: ssh->kex->failed_choice);
1.212 djm 1822: }
1823: /* FALLTHROUGH */
1.205 djm 1824: default:
1.280 djm 1825: if (vasprintf(&tag, fmt, ap) == -1) {
1826: ssh_packet_clear_keys(ssh);
1827: logdie("%s: could not allocate failure message",
1828: __func__);
1829: }
1.257 markus 1830: ssh_packet_clear_keys(ssh);
1.245 djm 1831: logdie("%s%sConnection %s %s: %s",
1.205 djm 1832: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 1833: ssh->state->server_side ? "from" : "to",
1.245 djm 1834: remote_id, ssh_err(r));
1.205 djm 1835: }
1.1 deraadt 1836: }
1837:
1.280 djm 1838: void
1839: sshpkt_fatal(struct ssh *ssh, int r, const char *fmt, ...)
1840: {
1841: va_list ap;
1842:
1843: va_start(ap, fmt);
1844: sshpkt_vfatal(ssh, r, fmt, ap);
1845: /* NOTREACHED */
1846: va_end(ap);
1847: logdie("%s: should have exited", __func__);
1848: }
1849:
1.16 markus 1850: /*
1851: * Logs the error plus constructs and sends a disconnect packet, closes the
1852: * connection, and exits. This function never returns. The error message
1853: * should not contain a newline. The length of the formatted message must
1854: * not exceed 1024 bytes.
1855: */
1.2 provos 1856: void
1.201 markus 1857: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1858: {
1.245 djm 1859: char buf[1024], remote_id[512];
1.14 markus 1860: va_list args;
1861: static int disconnecting = 0;
1.201 markus 1862: int r;
1.97 deraadt 1863:
1.14 markus 1864: if (disconnecting) /* Guard against recursive invocations. */
1865: fatal("packet_disconnect called recursively.");
1866: disconnecting = 1;
1867:
1.16 markus 1868: /*
1869: * Format the message. Note that the caller must make sure the
1870: * message is of limited size.
1871: */
1.268 dtucker 1872: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1873: va_start(args, fmt);
1874: vsnprintf(buf, sizeof(buf), fmt, args);
1875: va_end(args);
1876:
1.99 markus 1877: /* Display the error locally */
1.245 djm 1878: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1879:
1.205 djm 1880: /*
1881: * Send the disconnect message to the other side, and wait
1882: * for it to get sent.
1883: */
1884: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1.280 djm 1885: sshpkt_fatal(ssh, r, "%s", __func__);
1.205 djm 1886:
1887: if ((r = ssh_packet_write_wait(ssh)) != 0)
1.280 djm 1888: sshpkt_fatal(ssh, r, "%s", __func__);
1.14 markus 1889:
1890: /* Close the connection. */
1.201 markus 1891: ssh_packet_close(ssh);
1.112 markus 1892: cleanup_exit(255);
1.1 deraadt 1893: }
1894:
1.205 djm 1895: /*
1896: * Checks if there is any buffered output, and tries to write some of
1897: * the output.
1898: */
1899: int
1.201 markus 1900: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1901: {
1.201 markus 1902: struct session_state *state = ssh->state;
1903: int len = sshbuf_len(state->output);
1.222 markus 1904: int r;
1.97 deraadt 1905:
1.14 markus 1906: if (len > 0) {
1.222 markus 1907: len = write(state->connection_out,
1908: sshbuf_ptr(state->output), len);
1.156 djm 1909: if (len == -1) {
1910: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1911: return 0;
1912: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1913: }
1.222 markus 1914: if (len == 0)
1.205 djm 1915: return SSH_ERR_CONN_CLOSED;
1.201 markus 1916: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1917: return r;
1.14 markus 1918: }
1.205 djm 1919: return 0;
1.1 deraadt 1920: }
1921:
1.16 markus 1922: /*
1923: * Calls packet_write_poll repeatedly until all pending output data has been
1924: * written.
1925: */
1.205 djm 1926: int
1.201 markus 1927: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1928: {
1.56 millert 1929: fd_set *setp;
1.205 djm 1930: int ret, r, ms_remain = 0;
1.154 dtucker 1931: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1932: struct session_state *state = ssh->state;
1.56 millert 1933:
1.214 deraadt 1934: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1935: NFDBITS), sizeof(fd_mask));
1.201 markus 1936: if (setp == NULL)
1.205 djm 1937: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1938: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1939: free(setp);
1.215 djm 1940: return r;
1.216 gsoares 1941: }
1.201 markus 1942: while (ssh_packet_have_data_to_write(ssh)) {
1943: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1944: NFDBITS) * sizeof(fd_mask));
1.201 markus 1945: FD_SET(state->connection_out, setp);
1.154 dtucker 1946:
1.201 markus 1947: if (state->packet_timeout_ms > 0) {
1948: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1949: timeoutp = &timeout;
1950: }
1951: for (;;) {
1.201 markus 1952: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1953: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1954: monotime_tv(&start);
1.154 dtucker 1955: }
1.201 markus 1956: if ((ret = select(state->connection_out + 1,
1.161 andreas 1957: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1958: break;
1.161 andreas 1959: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1960: break;
1.201 markus 1961: if (state->packet_timeout_ms == -1)
1.154 dtucker 1962: continue;
1963: ms_subtract_diff(&start, &ms_remain);
1964: if (ms_remain <= 0) {
1965: ret = 0;
1966: break;
1967: }
1968: }
1969: if (ret == 0) {
1.205 djm 1970: free(setp);
1971: return SSH_ERR_CONN_TIMEOUT;
1972: }
1973: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1974: free(setp);
1975: return r;
1.154 dtucker 1976: }
1.14 markus 1977: }
1.186 djm 1978: free(setp);
1.205 djm 1979: return 0;
1.1 deraadt 1980: }
1981:
1982: /* Returns true if there is buffered data to write to the connection. */
1983:
1.2 provos 1984: int
1.201 markus 1985: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 1986: {
1.201 markus 1987: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 1988: }
1989:
1990: /* Returns true if there is not too much data to write to the connection. */
1991:
1.2 provos 1992: int
1.201 markus 1993: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 1994: {
1.201 markus 1995: if (ssh->state->interactive_mode)
1996: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 1997: else
1.201 markus 1998: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 1999: }
2000:
1.201 markus 2001: void
2002: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 2003: {
1.263 djm 2004: if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
1.101 markus 2005: return;
1.201 markus 2006: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 2007: case AF_INET:
2008: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 2009: if (setsockopt(ssh->state->connection_in,
1.173 djm 2010: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
2011: error("setsockopt IP_TOS %d: %.100s:",
2012: tos, strerror(errno));
2013: break;
2014: case AF_INET6:
2015: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 2016: if (setsockopt(ssh->state->connection_in,
1.173 djm 2017: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2018: error("setsockopt IPV6_TCLASS %d: %.100s:",
2019: tos, strerror(errno));
2020: break;
2021: }
1.101 markus 2022: }
2023:
1.1 deraadt 2024: /* Informs that the current session is interactive. Sets IP flags for that. */
2025:
1.2 provos 2026: void
1.201 markus 2027: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2028: {
1.201 markus 2029: struct session_state *state = ssh->state;
2030:
2031: if (state->set_interactive_called)
1.43 markus 2032: return;
1.201 markus 2033: state->set_interactive_called = 1;
1.1 deraadt 2034:
1.14 markus 2035: /* Record that we are in interactive mode. */
1.201 markus 2036: state->interactive_mode = interactive;
1.1 deraadt 2037:
1.19 markus 2038: /* Only set socket options if using a socket. */
1.201 markus 2039: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2040: return;
1.201 markus 2041: set_nodelay(state->connection_in);
2042: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2043: qos_bulk);
1.1 deraadt 2044: }
2045:
2046: /* Returns true if the current connection is interactive. */
2047:
1.2 provos 2048: int
1.201 markus 2049: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2050: {
1.201 markus 2051: return ssh->state->interactive_mode;
1.12 markus 2052: }
2053:
1.113 deraadt 2054: int
1.201 markus 2055: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2056: {
1.201 markus 2057: struct session_state *state = ssh->state;
2058:
2059: if (state->set_maxsize_called) {
1.106 itojun 2060: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2061: state->max_packet_size, s);
1.14 markus 2062: return -1;
2063: }
2064: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2065: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2066: return -1;
2067: }
1.201 markus 2068: state->set_maxsize_called = 1;
1.66 markus 2069: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2070: state->max_packet_size = s;
1.14 markus 2071: return s;
1.53 markus 2072: }
2073:
1.161 andreas 2074: int
1.201 markus 2075: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2076: {
1.201 markus 2077: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2078: }
2079:
2080: void
1.201 markus 2081: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2082: {
1.201 markus 2083: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2084: }
2085:
2086: u_int
1.201 markus 2087: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2088: {
1.201 markus 2089: return ssh->state->max_packet_size;
1.71 markus 2090: }
2091:
1.105 markus 2092: void
1.244 dtucker 2093: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2094: {
1.244 dtucker 2095: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2096: (unsigned int)seconds);
1.201 markus 2097: ssh->state->rekey_limit = bytes;
2098: ssh->state->rekey_interval = seconds;
1.184 dtucker 2099: }
2100:
2101: time_t
1.201 markus 2102: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2103: {
2104: time_t seconds;
2105:
1.201 markus 2106: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2107: monotime();
1.185 dtucker 2108: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2109: }
2110:
2111: void
1.201 markus 2112: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2113: {
1.201 markus 2114: ssh->state->server_side = 1;
1.278 djm 2115: ssh->kex->server = 1; /* XXX unify? */
1.118 markus 2116: }
2117:
2118: void
1.201 markus 2119: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2120: {
1.201 markus 2121: ssh->state->after_authentication = 1;
1.161 andreas 2122: }
2123:
2124: void *
1.201 markus 2125: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2126: {
1.201 markus 2127: return (void *)ssh->state->input;
1.161 andreas 2128: }
2129:
2130: void *
1.201 markus 2131: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2132: {
1.201 markus 2133: return (void *)ssh->state->output;
1.166 andreas 2134: }
2135:
1.196 markus 2136: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2137: static int
2138: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2139: {
1.239 djm 2140: int r;
1.196 markus 2141:
2142: debug("%s: called", __func__);
2143: /* This was set in net child, but is not visible in user child */
1.201 markus 2144: ssh->state->after_authentication = 1;
2145: ssh->state->rekeying = 0;
1.239 djm 2146: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2147: return r;
1.201 markus 2148: return 0;
2149: }
2150:
2151: /* Packet state (de-)serialization for privsep */
2152:
2153: /* turn kex into a blob for packet state serialization */
2154: static int
2155: kex_to_blob(struct sshbuf *m, struct kex *kex)
2156: {
2157: int r;
2158:
2159: if ((r = sshbuf_put_string(m, kex->session_id,
2160: kex->session_id_len)) != 0 ||
2161: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
1.269 djm 2162: (r = sshbuf_put_cstring(m, kex->hostkey_alg)) != 0 ||
1.201 markus 2163: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
1.269 djm 2164: (r = sshbuf_put_u32(m, kex->hostkey_nid)) != 0 ||
1.201 markus 2165: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2166: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2167: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
1.278 djm 2168: (r = sshbuf_put_stringb(m, kex->client_version)) != 0 ||
2169: (r = sshbuf_put_stringb(m, kex->server_version)) != 0 ||
2170: (r = sshbuf_put_u32(m, kex->flags)) != 0)
1.201 markus 2171: return r;
2172: return 0;
2173: }
2174:
2175: /* turn key exchange results into a blob for packet state serialization */
2176: static int
2177: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2178: {
2179: struct sshbuf *b;
2180: struct sshcipher_ctx *cc;
2181: struct sshcomp *comp;
2182: struct sshenc *enc;
2183: struct sshmac *mac;
2184: struct newkeys *newkey;
2185: int r;
2186:
2187: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2188: return SSH_ERR_INTERNAL_ERROR;
2189: enc = &newkey->enc;
2190: mac = &newkey->mac;
2191: comp = &newkey->comp;
1.235 djm 2192: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2193: ssh->state->receive_context;
1.201 markus 2194: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2195: return r;
2196: if ((b = sshbuf_new()) == NULL)
2197: return SSH_ERR_ALLOC_FAIL;
2198: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2199: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2200: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2201: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2202: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2203: goto out;
2204: if (cipher_authlen(enc->cipher) == 0) {
2205: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2206: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2207: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2208: goto out;
2209: }
2210: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2211: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2212: goto out;
2213: r = sshbuf_put_stringb(m, b);
2214: out:
1.221 mmcc 2215: sshbuf_free(b);
1.201 markus 2216: return r;
2217: }
2218:
2219: /* serialize packet state into a blob */
2220: int
2221: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2222: {
2223: struct session_state *state = ssh->state;
1.249 djm 2224: int r;
1.201 markus 2225:
1.249 djm 2226: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2227: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2228: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2229: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2230: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2231: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2232: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2233: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2234: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2235: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2236: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2237: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2238: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2239: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2240: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 2241: return r;
1.201 markus 2242:
2243: return 0;
2244: }
2245:
2246: /* restore key exchange results from blob for packet state de-serialization */
2247: static int
2248: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2249: {
2250: struct sshbuf *b = NULL;
2251: struct sshcomp *comp;
2252: struct sshenc *enc;
2253: struct sshmac *mac;
2254: struct newkeys *newkey = NULL;
2255: size_t keylen, ivlen, maclen;
2256: int r;
2257:
2258: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2259: r = SSH_ERR_ALLOC_FAIL;
2260: goto out;
2261: }
2262: if ((r = sshbuf_froms(m, &b)) != 0)
2263: goto out;
2264: #ifdef DEBUG_PK
2265: sshbuf_dump(b, stderr);
2266: #endif
2267: enc = &newkey->enc;
2268: mac = &newkey->mac;
2269: comp = &newkey->comp;
2270:
2271: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2272: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2273: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2274: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2275: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2276: goto out;
1.262 djm 2277: if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2278: r = SSH_ERR_INVALID_FORMAT;
2279: goto out;
2280: }
1.201 markus 2281: if (cipher_authlen(enc->cipher) == 0) {
2282: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2283: goto out;
2284: if ((r = mac_setup(mac, mac->name)) != 0)
2285: goto out;
2286: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2287: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2288: goto out;
2289: if (maclen > mac->key_len) {
2290: r = SSH_ERR_INVALID_FORMAT;
2291: goto out;
2292: }
2293: mac->key_len = maclen;
2294: }
2295: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2296: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2297: goto out;
2298: if (sshbuf_len(b) != 0) {
2299: r = SSH_ERR_INVALID_FORMAT;
2300: goto out;
2301: }
2302: enc->key_len = keylen;
2303: enc->iv_len = ivlen;
2304: ssh->kex->newkeys[mode] = newkey;
2305: newkey = NULL;
2306: r = 0;
2307: out:
1.219 mmcc 2308: free(newkey);
1.221 mmcc 2309: sshbuf_free(b);
1.201 markus 2310: return r;
2311: }
2312:
2313: /* restore kex from blob for packet state de-serialization */
2314: static int
2315: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2316: {
2317: struct kex *kex;
2318: int r;
2319:
1.278 djm 2320: if ((kex = kex_new()) == NULL)
2321: return SSH_ERR_ALLOC_FAIL;
1.201 markus 2322: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2323: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
1.269 djm 2324: (r = sshbuf_get_cstring(m, &kex->hostkey_alg, NULL)) != 0 ||
1.201 markus 2325: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
1.269 djm 2326: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_nid)) != 0 ||
1.201 markus 2327: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2328: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2329: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
1.278 djm 2330: (r = sshbuf_get_stringb(m, kex->client_version)) != 0 ||
2331: (r = sshbuf_get_stringb(m, kex->server_version)) != 0 ||
2332: (r = sshbuf_get_u32(m, &kex->flags)) != 0)
1.201 markus 2333: goto out;
2334: kex->server = 1;
2335: kex->done = 1;
2336: r = 0;
2337: out:
2338: if (r != 0 || kexp == NULL) {
1.278 djm 2339: kex_free(kex);
1.201 markus 2340: if (kexp != NULL)
2341: *kexp = NULL;
2342: } else {
1.278 djm 2343: kex_free(*kexp);
1.201 markus 2344: *kexp = kex;
2345: }
2346: return r;
2347: }
2348:
2349: /*
2350: * Restore packet state from content of blob 'm' (de-serialization).
2351: * Note that 'm' will be partially consumed on parsing or any other errors.
2352: */
2353: int
2354: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2355: {
2356: struct session_state *state = ssh->state;
1.254 djm 2357: const u_char *input, *output;
2358: size_t ilen, olen;
1.201 markus 2359: int r;
2360:
1.249 djm 2361: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2362: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2363: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2364: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2365: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2366: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2367: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2368: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2369: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2370: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2371: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2372: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2373: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2374: return r;
2375: /*
2376: * We set the time here so that in post-auth privsep slave we
2377: * count from the completion of the authentication.
2378: */
2379: state->rekey_time = monotime();
2380: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2381: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2382: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2383: return r;
1.201 markus 2384:
1.239 djm 2385: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2386: return r;
2387:
2388: sshbuf_reset(state->input);
2389: sshbuf_reset(state->output);
2390: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2391: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2392: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2393: (r = sshbuf_put(state->output, output, olen)) != 0)
2394: return r;
2395:
2396: if (sshbuf_len(m))
2397: return SSH_ERR_INVALID_FORMAT;
2398: debug3("%s: done", __func__);
2399: return 0;
2400: }
2401:
2402: /* NEW API */
2403:
2404: /* put data to the outgoing packet */
2405:
2406: int
2407: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2408: {
2409: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2410: }
2411:
2412: int
2413: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2414: {
2415: return sshbuf_putb(ssh->state->outgoing_packet, b);
2416: }
2417:
2418: int
2419: sshpkt_put_u8(struct ssh *ssh, u_char val)
2420: {
2421: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2422: }
2423:
2424: int
2425: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2426: {
2427: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2428: }
2429:
2430: int
2431: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2432: {
2433: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2434: }
2435:
2436: int
2437: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2438: {
2439: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2440: }
2441:
2442: int
2443: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2444: {
2445: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2446: }
2447:
2448: int
2449: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2450: {
2451: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2452: }
2453:
1.211 djm 2454: #ifdef WITH_OPENSSL
1.201 markus 2455: int
2456: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2457: {
2458: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2459: }
2460:
2461:
2462: int
2463: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2464: {
2465: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2466: }
1.211 djm 2467: #endif /* WITH_OPENSSL */
1.201 markus 2468:
2469: /* fetch data from the incoming packet */
2470:
2471: int
2472: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2473: {
2474: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2475: }
2476:
2477: int
2478: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2479: {
2480: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2481: }
2482:
2483: int
2484: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2485: {
2486: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2487: }
2488:
2489: int
2490: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2491: {
2492: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2493: }
2494:
2495: int
2496: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2497: {
2498: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2499: }
2500:
2501: int
2502: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2503: {
2504: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2505: }
2506:
2507: int
1.264 djm 2508: sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2509: {
2510: return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2511: }
2512:
2513: int
1.201 markus 2514: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2515: {
2516: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2517: }
2518:
1.211 djm 2519: #ifdef WITH_OPENSSL
1.201 markus 2520: int
2521: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2522: {
2523: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2524: }
2525:
2526: int
1.281 ! djm 2527: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM **valp)
1.201 markus 2528: {
1.281 ! djm 2529: return sshbuf_get_bignum2(ssh->state->incoming_packet, valp);
1.201 markus 2530: }
1.211 djm 2531: #endif /* WITH_OPENSSL */
1.201 markus 2532:
2533: int
2534: sshpkt_get_end(struct ssh *ssh)
2535: {
2536: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2537: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2538: return 0;
2539: }
2540:
2541: const u_char *
2542: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2543: {
2544: if (lenp != NULL)
2545: *lenp = sshbuf_len(ssh->state->incoming_packet);
2546: return sshbuf_ptr(ssh->state->incoming_packet);
2547: }
2548:
2549: /* start a new packet */
2550:
2551: int
2552: sshpkt_start(struct ssh *ssh, u_char type)
2553: {
1.249 djm 2554: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2555:
2556: DBG(debug("packet_start[%d]", type));
1.249 djm 2557: memset(buf, 0, sizeof(buf));
2558: buf[sizeof(buf) - 1] = type;
1.201 markus 2559: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2560: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2561: }
2562:
1.242 markus 2563: static int
2564: ssh_packet_send_mux(struct ssh *ssh)
2565: {
2566: struct session_state *state = ssh->state;
2567: u_char type, *cp;
2568: size_t len;
2569: int r;
2570:
2571: if (ssh->kex)
2572: return SSH_ERR_INTERNAL_ERROR;
2573: len = sshbuf_len(state->outgoing_packet);
2574: if (len < 6)
2575: return SSH_ERR_INTERNAL_ERROR;
2576: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2577: type = cp[5];
2578: if (ssh_packet_log_type(type))
2579: debug3("%s: type %u", __func__, type);
2580: /* drop everything, but the connection protocol */
2581: if (type >= SSH2_MSG_CONNECTION_MIN &&
2582: type <= SSH2_MSG_CONNECTION_MAX) {
2583: POKE_U32(cp, len - 4);
2584: if ((r = sshbuf_putb(state->output,
2585: state->outgoing_packet)) != 0)
2586: return r;
2587: /* sshbuf_dump(state->output, stderr); */
2588: }
2589: sshbuf_reset(state->outgoing_packet);
1.264 djm 2590: return 0;
2591: }
2592:
2593: /*
2594: * 9.2. Ignored Data Message
2595: *
2596: * byte SSH_MSG_IGNORE
2597: * string data
2598: *
2599: * All implementations MUST understand (and ignore) this message at any
2600: * time (after receiving the protocol version). No implementation is
2601: * required to send them. This message can be used as an additional
2602: * protection measure against advanced traffic analysis techniques.
2603: */
2604: int
2605: sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2606: {
2607: u_int32_t rnd = 0;
2608: int r;
2609: u_int i;
2610:
2611: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2612: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2613: return r;
2614: for (i = 0; i < nbytes; i++) {
2615: if (i % 4 == 0)
2616: rnd = arc4random();
2617: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2618: return r;
2619: rnd >>= 8;
2620: }
1.242 markus 2621: return 0;
2622: }
2623:
1.201 markus 2624: /* send it */
2625:
2626: int
2627: sshpkt_send(struct ssh *ssh)
2628: {
1.242 markus 2629: if (ssh->state && ssh->state->mux)
2630: return ssh_packet_send_mux(ssh);
1.249 djm 2631: return ssh_packet_send2(ssh);
1.201 markus 2632: }
2633:
2634: int
2635: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2636: {
2637: char buf[1024];
2638: va_list args;
2639: int r;
2640:
2641: va_start(args, fmt);
2642: vsnprintf(buf, sizeof(buf), fmt, args);
2643: va_end(args);
2644:
1.249 djm 2645: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2646: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2647: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2648: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2649: (r = sshpkt_send(ssh)) != 0)
2650: return r;
1.201 markus 2651: return 0;
2652: }
2653:
2654: /* roundup current message to pad bytes */
2655: int
2656: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2657: {
2658: ssh->state->extra_pad = pad;
2659: return 0;
1.1 deraadt 2660: }
![[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