Annotation of src/usr.bin/ssh/packet.c, Revision 1.283
1.283 ! djm 1: /* $OpenBSD: packet.c,v 1.282 2019/01/21 10:35:09 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;
1.283 ! djm 821: const char *dir = mode == MODE_OUT ? "out" : "in";
1.57 markus 822:
1.100 markus 823: debug2("set_newkeys: mode %d", mode);
1.57 markus 824:
1.88 markus 825: if (mode == MODE_OUT) {
1.235 djm 826: ccp = &state->send_context;
1.115 avsm 827: crypt_type = CIPHER_ENCRYPT;
1.236 markus 828: ps = &state->p_send;
1.201 markus 829: max_blocks = &state->max_blocks_out;
1.88 markus 830: } else {
1.235 djm 831: ccp = &state->receive_context;
1.115 avsm 832: crypt_type = CIPHER_DECRYPT;
1.236 markus 833: ps = &state->p_read;
1.201 markus 834: max_blocks = &state->max_blocks_in;
1.88 markus 835: }
1.201 markus 836: if (state->newkeys[mode] != NULL) {
1.283 ! djm 837: debug("%s: rekeying %s, input %llu bytes %llu blocks, "
! 838: "output %llu bytes %llu blocks", __func__, dir,
1.257 markus 839: (unsigned long long)state->p_read.bytes,
840: (unsigned long long)state->p_read.blocks,
841: (unsigned long long)state->p_send.bytes,
842: (unsigned long long)state->p_send.blocks);
843: kex_free_newkeys(state->newkeys[mode]);
844: state->newkeys[mode] = NULL;
1.57 markus 845: }
1.236 markus 846: /* note that both bytes and the seqnr are not reset */
847: ps->packets = ps->blocks = 0;
1.201 markus 848: /* move newkeys from kex to state */
849: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
850: return SSH_ERR_INTERNAL_ERROR;
851: ssh->kex->newkeys[mode] = NULL;
852: enc = &state->newkeys[mode]->enc;
853: mac = &state->newkeys[mode]->mac;
854: comp = &state->newkeys[mode]->comp;
855: if (cipher_authlen(enc->cipher) == 0) {
856: if ((r = mac_init(mac)) != 0)
857: return r;
858: }
859: mac->enabled = 1;
1.283 ! djm 860: DBG(debug("%s: cipher_init_context: %s", __func__, dir));
1.279 djm 861: cipher_free(*ccp);
862: *ccp = NULL;
1.235 djm 863: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 864: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 865: return r;
866: if (!state->cipher_warning_done &&
1.235 djm 867: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 868: error("Warning: %s", wmsg);
869: state->cipher_warning_done = 1;
870: }
1.91 markus 871: /* Deleting the keys does not gain extra security */
1.192 djm 872: /* explicit_bzero(enc->iv, enc->block_size);
873: explicit_bzero(enc->key, enc->key_len);
874: explicit_bzero(mac->key, mac->key_len); */
1.275 sf 875: if ((comp->type == COMP_ZLIB ||
876: (comp->type == COMP_DELAYED &&
877: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 878: if ((r = ssh_packet_init_compression(ssh)) < 0)
879: return r;
880: if (mode == MODE_OUT) {
881: if ((r = start_compression_out(ssh, 6)) != 0)
882: return r;
883: } else {
884: if ((r = start_compression_in(ssh)) != 0)
885: return r;
886: }
1.57 markus 887: comp->enabled = 1;
888: }
1.109 markus 889: /*
890: * The 2^(blocksize*2) limit is too expensive for 3DES,
1.254 djm 891: * so enforce a 1GB limit for small blocksizes.
1.261 dtucker 892: * See RFC4344 section 3.2.
1.109 markus 893: */
894: if (enc->block_size >= 16)
895: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
896: else
897: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 898: if (state->rekey_limit)
1.237 deraadt 899: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 900: state->rekey_limit / enc->block_size);
1.283 ! djm 901: debug("rekey %s after %llu blocks", dir,
! 902: (unsigned long long)*max_blocks);
1.201 markus 903: return 0;
1.57 markus 904: }
905:
1.228 djm 906: #define MAX_PACKETS (1U<<31)
907: static int
908: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
909: {
910: struct session_state *state = ssh->state;
911: u_int32_t out_blocks;
912:
913: /* XXX client can't cope with rekeying pre-auth */
914: if (!state->after_authentication)
915: return 0;
916:
917: /* Haven't keyed yet or KEX in progress. */
1.278 djm 918: if (ssh_packet_is_rekeying(ssh))
1.228 djm 919: return 0;
920:
921: /* Peer can't rekey */
922: if (ssh->compat & SSH_BUG_NOREKEY)
923: return 0;
924:
925: /*
926: * Permit one packet in or out per rekey - this allows us to
927: * make progress when rekey limits are very small.
928: */
929: if (state->p_send.packets == 0 && state->p_read.packets == 0)
930: return 0;
931:
932: /* Time-based rekeying */
933: if (state->rekey_interval != 0 &&
1.244 dtucker 934: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 935: return 1;
936:
1.261 dtucker 937: /*
938: * Always rekey when MAX_PACKETS sent in either direction
939: * As per RFC4344 section 3.1 we do this after 2^31 packets.
940: */
1.228 djm 941: if (state->p_send.packets > MAX_PACKETS ||
942: state->p_read.packets > MAX_PACKETS)
943: return 1;
944:
945: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 946: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 947: state->newkeys[MODE_OUT]->enc.block_size);
948: return (state->max_blocks_out &&
949: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
950: (state->max_blocks_in &&
951: (state->p_read.blocks > state->max_blocks_in));
952: }
953:
1.16 markus 954: /*
1.118 markus 955: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 956: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 957: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
958: */
1.201 markus 959: static int
960: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 961: {
1.201 markus 962: struct session_state *state = ssh->state;
963: struct sshcomp *comp = NULL;
964: int r, mode;
1.118 markus 965:
966: /*
967: * Remember that we are past the authentication step, so rekeying
1.275 sf 968: * with COMP_DELAYED will turn on compression immediately.
1.118 markus 969: */
1.201 markus 970: state->after_authentication = 1;
1.118 markus 971: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 972: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 973: if (state->newkeys[mode] == NULL)
1.145 markus 974: continue;
1.201 markus 975: comp = &state->newkeys[mode]->comp;
1.275 sf 976: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 977: if ((r = ssh_packet_init_compression(ssh)) != 0)
978: return r;
979: if (mode == MODE_OUT) {
980: if ((r = start_compression_out(ssh, 6)) != 0)
981: return r;
982: } else {
983: if ((r = start_compression_in(ssh)) != 0)
984: return r;
985: }
1.118 markus 986: comp->enabled = 1;
987: }
988: }
1.201 markus 989: return 0;
1.118 markus 990: }
991:
1.226 djm 992: /* Used to mute debug logging for noisy packet types */
1.242 markus 993: int
1.226 djm 994: ssh_packet_log_type(u_char type)
995: {
996: switch (type) {
997: case SSH2_MSG_CHANNEL_DATA:
998: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
999: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1000: return 0;
1001: default:
1002: return 1;
1003: }
1004: }
1005:
1.118 markus 1006: /*
1.25 markus 1007: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1008: */
1.201 markus 1009: int
1010: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1011: {
1.201 markus 1012: struct session_state *state = ssh->state;
1.200 markus 1013: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1014: u_char tmp, padlen, pad = 0;
1.201 markus 1015: u_int authlen = 0, aadlen = 0;
1016: u_int len;
1017: struct sshenc *enc = NULL;
1018: struct sshmac *mac = NULL;
1019: struct sshcomp *comp = NULL;
1020: int r, block_size;
1021:
1022: if (state->newkeys[MODE_OUT] != NULL) {
1023: enc = &state->newkeys[MODE_OUT]->enc;
1024: mac = &state->newkeys[MODE_OUT]->mac;
1025: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1026: /* disable mac for authenticated encryption */
1027: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1028: mac = NULL;
1.25 markus 1029: }
1.88 markus 1030: block_size = enc ? enc->block_size : 8;
1.180 markus 1031: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1032:
1.201 markus 1033: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1034: if (ssh_packet_log_type(type))
1035: debug3("send packet: type %u", type);
1.25 markus 1036: #ifdef PACKET_DEBUG
1037: fprintf(stderr, "plain: ");
1.201 markus 1038: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1039: #endif
1040:
1041: if (comp && comp->enabled) {
1.201 markus 1042: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1043: /* skip header, compress only payload */
1.201 markus 1044: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1045: goto out;
1046: sshbuf_reset(state->compression_buffer);
1047: if ((r = compress_buffer(ssh, state->outgoing_packet,
1048: state->compression_buffer)) != 0)
1049: goto out;
1050: sshbuf_reset(state->outgoing_packet);
1051: if ((r = sshbuf_put(state->outgoing_packet,
1052: "\0\0\0\0\0", 5)) != 0 ||
1053: (r = sshbuf_putb(state->outgoing_packet,
1054: state->compression_buffer)) != 0)
1055: goto out;
1056: DBG(debug("compression: raw %d compressed %zd", len,
1057: sshbuf_len(state->outgoing_packet)));
1.25 markus 1058: }
1059:
1060: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1061: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1062:
1063: /*
1064: * calc size of padding, alloc space, get random data,
1065: * minimum padding is 4 bytes
1066: */
1.178 markus 1067: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1068: padlen = block_size - (len % block_size);
1069: if (padlen < 4)
1070: padlen += block_size;
1.201 markus 1071: if (state->extra_pad) {
1.233 djm 1072: tmp = state->extra_pad;
1.201 markus 1073: state->extra_pad =
1.237 deraadt 1074: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1075: /* check if roundup overflowed */
1076: if (state->extra_pad < tmp)
1077: return SSH_ERR_INVALID_ARGUMENT;
1078: tmp = (len + padlen) % state->extra_pad;
1079: /* Check whether pad calculation below will underflow */
1080: if (tmp > state->extra_pad)
1081: return SSH_ERR_INVALID_ARGUMENT;
1082: pad = state->extra_pad - tmp;
1.193 djm 1083: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1084: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1085: tmp = padlen;
1.71 markus 1086: padlen += pad;
1.233 djm 1087: /* Check whether padlen calculation overflowed */
1088: if (padlen < tmp)
1089: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1090: state->extra_pad = 0;
1.71 markus 1091: }
1.201 markus 1092: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1093: goto out;
1.235 djm 1094: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1095: /* random padding */
1.201 markus 1096: arc4random_buf(cp, padlen);
1.32 markus 1097: } else {
1098: /* clear padding */
1.192 djm 1099: explicit_bzero(cp, padlen);
1.25 markus 1100: }
1.178 markus 1101: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1102: len = sshbuf_len(state->outgoing_packet);
1103: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1104: if (cp == NULL) {
1105: r = SSH_ERR_INTERNAL_ERROR;
1106: goto out;
1107: }
1.25 markus 1108: /* packet_length includes payload, padding and padding length field */
1.201 markus 1109: POKE_U32(cp, len - 4);
1.89 markus 1110: cp[4] = padlen;
1.178 markus 1111: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1112: len, padlen, aadlen));
1.25 markus 1113:
1114: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1115: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1116: if ((r = mac_compute(mac, state->p_send.seqnr,
1117: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1118: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1119: goto out;
1120: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1121: }
1122: /* encrypt packet and append to output buffer. */
1.201 markus 1123: if ((r = sshbuf_reserve(state->output,
1124: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1125: goto out;
1.235 djm 1126: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1127: sshbuf_ptr(state->outgoing_packet),
1128: len - aadlen, aadlen, authlen)) != 0)
1129: goto out;
1.25 markus 1130: /* append unencrypted MAC */
1.178 markus 1131: if (mac && mac->enabled) {
1132: if (mac->etm) {
1133: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1134: if ((r = mac_compute(mac, state->p_send.seqnr,
1135: cp, len, macbuf, sizeof(macbuf))) != 0)
1136: goto out;
1.178 markus 1137: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1138: state->p_send.seqnr));
1.178 markus 1139: }
1.201 markus 1140: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1141: goto out;
1.178 markus 1142: }
1.25 markus 1143: #ifdef PACKET_DEBUG
1144: fprintf(stderr, "encrypted: ");
1.201 markus 1145: sshbuf_dump(state->output, stderr);
1.25 markus 1146: #endif
1.29 markus 1147: /* increment sequence number for outgoing packets */
1.201 markus 1148: if (++state->p_send.seqnr == 0)
1.106 itojun 1149: logit("outgoing seqnr wraps around");
1.201 markus 1150: if (++state->p_send.packets == 0)
1151: if (!(ssh->compat & SSH_BUG_NOREKEY))
1152: return SSH_ERR_NEED_REKEY;
1153: state->p_send.blocks += len / block_size;
1154: state->p_send.bytes += len;
1155: sshbuf_reset(state->outgoing_packet);
1.25 markus 1156:
1.57 markus 1157: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1158: r = ssh_set_newkeys(ssh, MODE_OUT);
1159: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1160: r = ssh_packet_enable_delayed_compress(ssh);
1161: else
1162: r = 0;
1163: out:
1164: return r;
1.25 markus 1165: }
1166:
1.228 djm 1167: /* returns non-zero if the specified packet type is usec by KEX */
1168: static int
1169: ssh_packet_type_is_kex(u_char type)
1170: {
1171: return
1172: type >= SSH2_MSG_TRANSPORT_MIN &&
1173: type <= SSH2_MSG_TRANSPORT_MAX &&
1174: type != SSH2_MSG_SERVICE_REQUEST &&
1175: type != SSH2_MSG_SERVICE_ACCEPT &&
1176: type != SSH2_MSG_EXT_INFO;
1177: }
1178:
1.201 markus 1179: int
1180: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1181: {
1.201 markus 1182: struct session_state *state = ssh->state;
1.105 markus 1183: struct packet *p;
1.201 markus 1184: u_char type;
1.228 djm 1185: int r, need_rekey;
1.105 markus 1186:
1.228 djm 1187: if (sshbuf_len(state->outgoing_packet) < 6)
1188: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1189: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1190: need_rekey = !ssh_packet_type_is_kex(type) &&
1191: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1192:
1.228 djm 1193: /*
1194: * During rekeying we can only send key exchange messages.
1195: * Queue everything else.
1196: */
1197: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1198: if (need_rekey)
1199: debug3("%s: rekex triggered", __func__);
1200: debug("enqueue packet: %u", type);
1201: p = calloc(1, sizeof(*p));
1202: if (p == NULL)
1203: return SSH_ERR_ALLOC_FAIL;
1204: p->type = type;
1205: p->payload = state->outgoing_packet;
1206: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1207: state->outgoing_packet = sshbuf_new();
1208: if (state->outgoing_packet == NULL)
1209: return SSH_ERR_ALLOC_FAIL;
1210: if (need_rekey) {
1211: /*
1212: * This packet triggered a rekey, so send the
1213: * KEXINIT now.
1214: * NB. reenters this function via kex_start_rekex().
1215: */
1216: return kex_start_rekex(ssh);
1.105 markus 1217: }
1.228 djm 1218: return 0;
1.105 markus 1219: }
1220:
1221: /* rekeying starts with sending KEXINIT */
1222: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1223: state->rekeying = 1;
1.105 markus 1224:
1.201 markus 1225: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1226: return r;
1.105 markus 1227:
1228: /* after a NEWKEYS message we can send the complete queue */
1229: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1230: state->rekeying = 0;
1231: state->rekey_time = monotime();
1232: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1233: type = p->type;
1.228 djm 1234: /*
1235: * If this packet triggers a rekex, then skip the
1236: * remaining packets in the queue for now.
1237: * NB. re-enters this function via kex_start_rekex.
1238: */
1239: if (ssh_packet_need_rekeying(ssh,
1240: sshbuf_len(p->payload))) {
1241: debug3("%s: queued packet triggered rekex",
1242: __func__);
1243: return kex_start_rekex(ssh);
1244: }
1.105 markus 1245: debug("dequeue packet: %u", type);
1.201 markus 1246: sshbuf_free(state->outgoing_packet);
1247: state->outgoing_packet = p->payload;
1248: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1249: memset(p, 0, sizeof(*p));
1.186 djm 1250: free(p);
1.201 markus 1251: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1252: return r;
1.105 markus 1253: }
1254: }
1.201 markus 1255: return 0;
1.25 markus 1256: }
1257:
1258: /*
1.16 markus 1259: * Waits until a packet has been received, and returns its type. Note that
1260: * no other data is processed until this returns, so this function should not
1261: * be used during the interactive session.
1262: */
1.1 deraadt 1263:
1.2 provos 1264: int
1.201 markus 1265: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1266: {
1.201 markus 1267: struct session_state *state = ssh->state;
1.222 markus 1268: int len, r, ms_remain;
1.56 millert 1269: fd_set *setp;
1.14 markus 1270: char buf[8192];
1.155 deraadt 1271: struct timeval timeout, start, *timeoutp = NULL;
1272:
1.25 markus 1273: DBG(debug("packet_read()"));
1.14 markus 1274:
1.214 deraadt 1275: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1276: NFDBITS), sizeof(fd_mask));
1.201 markus 1277: if (setp == NULL)
1278: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1279:
1.205 djm 1280: /*
1281: * Since we are blocking, ensure that all written packets have
1282: * been sent.
1283: */
1.210 markus 1284: if ((r = ssh_packet_write_wait(ssh)) != 0)
1285: goto out;
1.14 markus 1286:
1287: /* Stay in the loop until we have received a complete packet. */
1288: for (;;) {
1289: /* Try to read a packet from the buffer. */
1.201 markus 1290: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1291: if (r != 0)
1292: break;
1.14 markus 1293: /* If we got a packet, return it. */
1.201 markus 1294: if (*typep != SSH_MSG_NONE)
1295: break;
1.16 markus 1296: /*
1297: * Otherwise, wait for some data to arrive, add it to the
1298: * buffer, and try again.
1299: */
1.201 markus 1300: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1301: NFDBITS) * sizeof(fd_mask));
1.201 markus 1302: FD_SET(state->connection_in, setp);
1.16 markus 1303:
1.201 markus 1304: if (state->packet_timeout_ms > 0) {
1305: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1306: timeoutp = &timeout;
1307: }
1.14 markus 1308: /* Wait for some data to arrive. */
1.154 dtucker 1309: for (;;) {
1.201 markus 1310: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1311: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1312: monotime_tv(&start);
1.154 dtucker 1313: }
1.201 markus 1314: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1315: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1316: break;
1.270 dtucker 1317: if (errno != EAGAIN && errno != EINTR) {
1318: r = SSH_ERR_SYSTEM_ERROR;
1319: goto out;
1320: }
1.201 markus 1321: if (state->packet_timeout_ms == -1)
1.154 dtucker 1322: continue;
1323: ms_subtract_diff(&start, &ms_remain);
1324: if (ms_remain <= 0) {
1.201 markus 1325: r = 0;
1.154 dtucker 1326: break;
1327: }
1328: }
1.246 djm 1329: if (r == 0) {
1330: r = SSH_ERR_CONN_TIMEOUT;
1331: goto out;
1332: }
1.14 markus 1333: /* Read data from the socket. */
1.222 markus 1334: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1335: if (len == 0) {
1336: r = SSH_ERR_CONN_CLOSED;
1337: goto out;
1338: }
1339: if (len < 0) {
1340: r = SSH_ERR_SYSTEM_ERROR;
1341: goto out;
1342: }
1.204 djm 1343:
1.14 markus 1344: /* Append it to the buffer. */
1.204 djm 1345: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1346: goto out;
1.14 markus 1347: }
1.210 markus 1348: out:
1.201 markus 1349: free(setp);
1350: return r;
1.1 deraadt 1351: }
1352:
1.77 djm 1353: int
1.201 markus 1354: ssh_packet_read(struct ssh *ssh)
1.77 djm 1355: {
1.201 markus 1356: u_char type;
1357: int r;
1358:
1359: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1360: fatal("%s: %s", __func__, ssh_err(r));
1361: return type;
1.77 djm 1362: }
1363:
1.16 markus 1364: /*
1365: * Waits until a packet has been received, verifies that its type matches
1366: * that given, and gives a fatal error and exits if there is a mismatch.
1367: */
1.1 deraadt 1368:
1.205 djm 1369: int
1370: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1371: {
1.205 djm 1372: int r;
1373: u_char type;
1.1 deraadt 1374:
1.205 djm 1375: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1376: return r;
1377: if (type != expected_type) {
1378: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1379: "Protocol error: expected packet type %d, got %d",
1.205 djm 1380: expected_type, type)) != 0)
1381: return r;
1382: return SSH_ERR_PROTOCOL_ERROR;
1383: }
1384: return 0;
1.1 deraadt 1385: }
1.14 markus 1386:
1.242 markus 1387: static int
1388: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1389: {
1390: struct session_state *state = ssh->state;
1391: const u_char *cp;
1392: size_t need;
1393: int r;
1394:
1395: if (ssh->kex)
1396: return SSH_ERR_INTERNAL_ERROR;
1397: *typep = SSH_MSG_NONE;
1398: cp = sshbuf_ptr(state->input);
1399: if (state->packlen == 0) {
1400: if (sshbuf_len(state->input) < 4 + 1)
1401: return 0; /* packet is incomplete */
1402: state->packlen = PEEK_U32(cp);
1403: if (state->packlen < 4 + 1 ||
1404: state->packlen > PACKET_MAX_SIZE)
1405: return SSH_ERR_MESSAGE_INCOMPLETE;
1406: }
1407: need = state->packlen + 4;
1408: if (sshbuf_len(state->input) < need)
1409: return 0; /* packet is incomplete */
1410: sshbuf_reset(state->incoming_packet);
1411: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1412: state->packlen)) != 0 ||
1413: (r = sshbuf_consume(state->input, need)) != 0 ||
1414: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1415: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1416: return r;
1417: if (ssh_packet_log_type(*typep))
1418: debug3("%s: type %u", __func__, *typep);
1419: /* sshbuf_dump(state->incoming_packet, stderr); */
1420: /* reset for next packet */
1421: state->packlen = 0;
1422: return r;
1423: }
1424:
1.201 markus 1425: int
1426: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1427: {
1.201 markus 1428: struct session_state *state = ssh->state;
1.40 markus 1429: u_int padlen, need;
1.231 djm 1430: u_char *cp;
1.201 markus 1431: u_int maclen, aadlen = 0, authlen = 0, block_size;
1432: struct sshenc *enc = NULL;
1433: struct sshmac *mac = NULL;
1434: struct sshcomp *comp = NULL;
1.200 markus 1435: int r;
1.201 markus 1436:
1.242 markus 1437: if (state->mux)
1438: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1439:
1.201 markus 1440: *typep = SSH_MSG_NONE;
1441:
1442: if (state->packet_discard)
1443: return 0;
1444:
1445: if (state->newkeys[MODE_IN] != NULL) {
1446: enc = &state->newkeys[MODE_IN]->enc;
1447: mac = &state->newkeys[MODE_IN]->mac;
1448: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1449: /* disable mac for authenticated encryption */
1450: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1451: mac = NULL;
1.25 markus 1452: }
1453: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1454: block_size = enc ? enc->block_size : 8;
1.180 markus 1455: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1456:
1.201 markus 1457: if (aadlen && state->packlen == 0) {
1.235 djm 1458: if (cipher_get_length(state->receive_context,
1.201 markus 1459: &state->packlen, state->p_read.seqnr,
1460: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1461: return 0;
1462: if (state->packlen < 1 + 4 ||
1463: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1464: #ifdef PACKET_DEBUG
1.201 markus 1465: sshbuf_dump(state->input, stderr);
1.178 markus 1466: #endif
1.201 markus 1467: logit("Bad packet length %u.", state->packlen);
1468: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1469: return r;
1.217 djm 1470: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1471: }
1.201 markus 1472: sshbuf_reset(state->incoming_packet);
1473: } else if (state->packlen == 0) {
1.25 markus 1474: /*
1475: * check if input size is less than the cipher block size,
1476: * decrypt first block and extract length of incoming packet
1477: */
1.201 markus 1478: if (sshbuf_len(state->input) < block_size)
1479: return 0;
1480: sshbuf_reset(state->incoming_packet);
1481: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1482: &cp)) != 0)
1483: goto out;
1.235 djm 1484: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1485: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1486: block_size, 0, 0)) != 0)
1487: goto out;
1488: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1489: if (state->packlen < 1 + 4 ||
1490: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1491: #ifdef PACKET_DEBUG
1.201 markus 1492: fprintf(stderr, "input: \n");
1493: sshbuf_dump(state->input, stderr);
1494: fprintf(stderr, "incoming_packet: \n");
1495: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1496: #endif
1.201 markus 1497: logit("Bad packet length %u.", state->packlen);
1.234 markus 1498: return ssh_packet_start_discard(ssh, enc, mac, 0,
1499: PACKET_MAX_SIZE);
1.25 markus 1500: }
1.201 markus 1501: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1502: goto out;
1.25 markus 1503: }
1.201 markus 1504: DBG(debug("input: packet len %u", state->packlen+4));
1505:
1.178 markus 1506: if (aadlen) {
1507: /* only the payload is encrypted */
1.201 markus 1508: need = state->packlen;
1.178 markus 1509: } else {
1510: /*
1511: * the payload size and the payload are encrypted, but we
1512: * have a partial packet of block_size bytes
1513: */
1.201 markus 1514: need = 4 + state->packlen - block_size;
1.178 markus 1515: }
1.180 markus 1516: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1517: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1518: if (need % block_size != 0) {
1519: logit("padding error: need %d block %d mod %d",
1.25 markus 1520: need, block_size, need % block_size);
1.234 markus 1521: return ssh_packet_start_discard(ssh, enc, mac, 0,
1522: PACKET_MAX_SIZE - block_size);
1.158 markus 1523: }
1.25 markus 1524: /*
1525: * check if the entire packet has been received and
1.178 markus 1526: * decrypt into incoming_packet:
1527: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1528: * 'need' bytes are encrypted, followed by either
1529: * 'authlen' bytes of authentication tag or
1.178 markus 1530: * 'maclen' bytes of message authentication code.
1.25 markus 1531: */
1.201 markus 1532: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1533: return 0; /* packet is incomplete */
1.25 markus 1534: #ifdef PACKET_DEBUG
1535: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1536: sshbuf_dump(state->input, stderr);
1.25 markus 1537: #endif
1.231 djm 1538: /* EtM: check mac over encrypted input */
1.201 markus 1539: if (mac && mac->enabled && mac->etm) {
1.231 djm 1540: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1541: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1542: sshbuf_ptr(state->input) + aadlen + need + authlen,
1543: maclen)) != 0) {
1544: if (r == SSH_ERR_MAC_INVALID)
1545: logit("Corrupted MAC on input.");
1.201 markus 1546: goto out;
1.231 djm 1547: }
1.201 markus 1548: }
1549: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1550: &cp)) != 0)
1551: goto out;
1.235 djm 1552: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1553: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1554: goto out;
1555: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1556: goto out;
1.29 markus 1557: if (mac && mac->enabled) {
1.231 djm 1558: /* Not EtM: check MAC over cleartext */
1559: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1560: sshbuf_ptr(state->incoming_packet),
1561: sshbuf_len(state->incoming_packet),
1562: sshbuf_ptr(state->input), maclen)) != 0) {
1563: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1564: goto out;
1.159 markus 1565: logit("Corrupted MAC on input.");
1.247 markus 1566: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1567: return SSH_ERR_INTERNAL_ERROR;
1568: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1569: sshbuf_len(state->incoming_packet),
1.247 markus 1570: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1571: }
1.231 djm 1572: /* Remove MAC from input buffer */
1.201 markus 1573: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1574: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1575: goto out;
1.25 markus 1576: }
1.77 djm 1577: if (seqnr_p != NULL)
1.201 markus 1578: *seqnr_p = state->p_read.seqnr;
1579: if (++state->p_read.seqnr == 0)
1.106 itojun 1580: logit("incoming seqnr wraps around");
1.201 markus 1581: if (++state->p_read.packets == 0)
1582: if (!(ssh->compat & SSH_BUG_NOREKEY))
1583: return SSH_ERR_NEED_REKEY;
1584: state->p_read.blocks += (state->packlen + 4) / block_size;
1585: state->p_read.bytes += state->packlen + 4;
1.25 markus 1586:
1587: /* get padlen */
1.201 markus 1588: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1589: DBG(debug("input: padlen %d", padlen));
1.205 djm 1590: if (padlen < 4) {
1591: if ((r = sshpkt_disconnect(ssh,
1592: "Corrupted padlen %d on input.", padlen)) != 0 ||
1593: (r = ssh_packet_write_wait(ssh)) != 0)
1594: return r;
1595: return SSH_ERR_CONN_CORRUPT;
1596: }
1.25 markus 1597:
1598: /* skip packet size + padlen, discard padding */
1.201 markus 1599: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1600: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1601: goto out;
1.25 markus 1602:
1.201 markus 1603: DBG(debug("input: len before de-compress %zd",
1604: sshbuf_len(state->incoming_packet)));
1.25 markus 1605: if (comp && comp->enabled) {
1.201 markus 1606: sshbuf_reset(state->compression_buffer);
1607: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1608: state->compression_buffer)) != 0)
1609: goto out;
1610: sshbuf_reset(state->incoming_packet);
1611: if ((r = sshbuf_putb(state->incoming_packet,
1612: state->compression_buffer)) != 0)
1613: goto out;
1614: DBG(debug("input: len after de-compress %zd",
1615: sshbuf_len(state->incoming_packet)));
1.25 markus 1616: }
1617: /*
1618: * get packet type, implies consume.
1619: * return length of payload (without type field)
1620: */
1.201 markus 1621: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1622: goto out;
1.226 djm 1623: if (ssh_packet_log_type(*typep))
1624: debug3("receive packet: type %u", *typep);
1.205 djm 1625: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1626: if ((r = sshpkt_disconnect(ssh,
1627: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1628: (r = ssh_packet_write_wait(ssh)) != 0)
1629: return r;
1630: return SSH_ERR_PROTOCOL_ERROR;
1631: }
1.243 djm 1632: if (state->hook_in != NULL &&
1633: (r = state->hook_in(ssh, state->incoming_packet, typep,
1634: state->hook_in_ctx)) != 0)
1635: return r;
1.238 markus 1636: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1637: r = ssh_packet_enable_delayed_compress(ssh);
1638: else
1639: r = 0;
1.25 markus 1640: #ifdef PACKET_DEBUG
1.201 markus 1641: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1642: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1643: #endif
1.62 markus 1644: /* reset for next packet */
1.201 markus 1645: state->packlen = 0;
1.228 djm 1646:
1647: /* do we need to rekey? */
1648: if (ssh_packet_need_rekeying(ssh, 0)) {
1649: debug3("%s: rekex triggered", __func__);
1650: if ((r = kex_start_rekex(ssh)) != 0)
1651: return r;
1652: }
1.201 markus 1653: out:
1654: return r;
1.25 markus 1655: }
1656:
1657: int
1.201 markus 1658: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1659: {
1.201 markus 1660: struct session_state *state = ssh->state;
1.96 deraadt 1661: u_int reason, seqnr;
1.201 markus 1662: int r;
1663: u_char *msg;
1.62 markus 1664:
1.25 markus 1665: for (;;) {
1.201 markus 1666: msg = NULL;
1.249 djm 1667: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1668: if (r != 0)
1669: return r;
1670: if (*typep) {
1671: state->keep_alive_timeouts = 0;
1672: DBG(debug("received packet type %d", *typep));
1673: }
1674: switch (*typep) {
1675: case SSH2_MSG_IGNORE:
1676: debug3("Received SSH2_MSG_IGNORE");
1677: break;
1678: case SSH2_MSG_DEBUG:
1679: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1680: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1681: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1682: free(msg);
1.201 markus 1683: return r;
1.48 stevesk 1684: }
1.249 djm 1685: debug("Remote: %.900s", msg);
1686: free(msg);
1687: break;
1688: case SSH2_MSG_DISCONNECT:
1689: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1690: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1691: return r;
1692: /* Ignore normal client exit notifications */
1693: do_log2(ssh->state->server_side &&
1694: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1695: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1696: "Received disconnect from %s port %d:"
1697: "%u: %.400s", ssh_remote_ipaddr(ssh),
1698: ssh_remote_port(ssh), reason, msg);
1699: free(msg);
1700: return SSH_ERR_DISCONNECTED;
1701: case SSH2_MSG_UNIMPLEMENTED:
1702: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1703: return r;
1704: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1705: seqnr);
1706: break;
1707: default:
1708: return 0;
1.25 markus 1709: }
1710: }
1711: }
1712:
1.16 markus 1713: /*
1714: * Buffers the given amount of input characters. This is intended to be used
1715: * together with packet_read_poll.
1716: */
1.1 deraadt 1717:
1.204 djm 1718: int
1.201 markus 1719: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1720: {
1.201 markus 1721: struct session_state *state = ssh->state;
1722: int r;
1723:
1724: if (state->packet_discard) {
1725: state->keep_alive_timeouts = 0; /* ?? */
1726: if (len >= state->packet_discard) {
1727: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1728: return r;
1.201 markus 1729: }
1730: state->packet_discard -= len;
1.204 djm 1731: return 0;
1.159 markus 1732: }
1.201 markus 1733: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1734: return r;
1735:
1736: return 0;
1.28 markus 1737: }
1738:
1739: int
1.201 markus 1740: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1741: {
1.201 markus 1742: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1743: }
1744:
1.16 markus 1745: /*
1746: * Sends a diagnostic message from the server to the client. This message
1747: * can be sent at any time (but not while constructing another message). The
1748: * message is printed immediately, but only if the client is being executed
1749: * in verbose mode. These messages are primarily intended to ease debugging
1750: * authentication problems. The length of the formatted message must not
1.205 djm 1751: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1752: */
1.2 provos 1753: void
1.201 markus 1754: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1755: {
1.14 markus 1756: char buf[1024];
1757: va_list args;
1.201 markus 1758: int r;
1.39 markus 1759:
1.249 djm 1760: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1761: return;
1.14 markus 1762:
1763: va_start(args, fmt);
1764: vsnprintf(buf, sizeof(buf), fmt, args);
1765: va_end(args);
1.265 djm 1766:
1767: debug3("sending debug message: %s", buf);
1.14 markus 1768:
1.249 djm 1769: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1770: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1771: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1772: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1773: (r = sshpkt_send(ssh)) != 0 ||
1774: (r = ssh_packet_write_wait(ssh)) != 0)
1.205 djm 1775: fatal("%s: %s", __func__, ssh_err(r));
1776: }
1777:
1.268 dtucker 1778: void
1779: sshpkt_fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1.245 djm 1780: {
1781: snprintf(s, l, "%.200s%s%s port %d",
1782: ssh->log_preamble ? ssh->log_preamble : "",
1783: ssh->log_preamble ? " " : "",
1784: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1785: }
1786:
1.205 djm 1787: /*
1788: * Pretty-print connection-terminating errors and exit.
1789: */
1.280 djm 1790: static void
1791: sshpkt_vfatal(struct ssh *ssh, int r, const char *fmt, va_list ap)
1.205 djm 1792: {
1.280 djm 1793: char *tag = NULL, remote_id[512];
1.245 djm 1794:
1.268 dtucker 1795: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.245 djm 1796:
1.205 djm 1797: switch (r) {
1798: case SSH_ERR_CONN_CLOSED:
1.257 markus 1799: ssh_packet_clear_keys(ssh);
1.245 djm 1800: logdie("Connection closed by %s", remote_id);
1.205 djm 1801: case SSH_ERR_CONN_TIMEOUT:
1.257 markus 1802: ssh_packet_clear_keys(ssh);
1.245 djm 1803: logdie("Connection %s %s timed out",
1804: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1805: case SSH_ERR_DISCONNECTED:
1.257 markus 1806: ssh_packet_clear_keys(ssh);
1.245 djm 1807: logdie("Disconnected from %s", remote_id);
1.212 djm 1808: case SSH_ERR_SYSTEM_ERROR:
1.257 markus 1809: if (errno == ECONNRESET) {
1810: ssh_packet_clear_keys(ssh);
1.245 djm 1811: logdie("Connection reset by %s", remote_id);
1.257 markus 1812: }
1.213 djm 1813: /* FALLTHROUGH */
1814: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1815: case SSH_ERR_NO_MAC_ALG_MATCH:
1816: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1817: case SSH_ERR_NO_KEX_ALG_MATCH:
1818: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1819: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.257 markus 1820: ssh_packet_clear_keys(ssh);
1.245 djm 1821: logdie("Unable to negotiate with %s: %s. "
1822: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1823: ssh->kex->failed_choice);
1.212 djm 1824: }
1825: /* FALLTHROUGH */
1.205 djm 1826: default:
1.280 djm 1827: if (vasprintf(&tag, fmt, ap) == -1) {
1828: ssh_packet_clear_keys(ssh);
1829: logdie("%s: could not allocate failure message",
1830: __func__);
1831: }
1.257 markus 1832: ssh_packet_clear_keys(ssh);
1.245 djm 1833: logdie("%s%sConnection %s %s: %s",
1.205 djm 1834: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 1835: ssh->state->server_side ? "from" : "to",
1.245 djm 1836: remote_id, ssh_err(r));
1.205 djm 1837: }
1.1 deraadt 1838: }
1839:
1.280 djm 1840: void
1841: sshpkt_fatal(struct ssh *ssh, int r, const char *fmt, ...)
1842: {
1843: va_list ap;
1844:
1845: va_start(ap, fmt);
1846: sshpkt_vfatal(ssh, r, fmt, ap);
1847: /* NOTREACHED */
1848: va_end(ap);
1849: logdie("%s: should have exited", __func__);
1850: }
1851:
1.16 markus 1852: /*
1853: * Logs the error plus constructs and sends a disconnect packet, closes the
1854: * connection, and exits. This function never returns. The error message
1855: * should not contain a newline. The length of the formatted message must
1856: * not exceed 1024 bytes.
1857: */
1.2 provos 1858: void
1.201 markus 1859: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1860: {
1.245 djm 1861: char buf[1024], remote_id[512];
1.14 markus 1862: va_list args;
1863: static int disconnecting = 0;
1.201 markus 1864: int r;
1.97 deraadt 1865:
1.14 markus 1866: if (disconnecting) /* Guard against recursive invocations. */
1867: fatal("packet_disconnect called recursively.");
1868: disconnecting = 1;
1869:
1.16 markus 1870: /*
1871: * Format the message. Note that the caller must make sure the
1872: * message is of limited size.
1873: */
1.268 dtucker 1874: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1875: va_start(args, fmt);
1876: vsnprintf(buf, sizeof(buf), fmt, args);
1877: va_end(args);
1878:
1.99 markus 1879: /* Display the error locally */
1.245 djm 1880: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1881:
1.205 djm 1882: /*
1883: * Send the disconnect message to the other side, and wait
1884: * for it to get sent.
1885: */
1886: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1.280 djm 1887: sshpkt_fatal(ssh, r, "%s", __func__);
1.205 djm 1888:
1889: if ((r = ssh_packet_write_wait(ssh)) != 0)
1.280 djm 1890: sshpkt_fatal(ssh, r, "%s", __func__);
1.14 markus 1891:
1892: /* Close the connection. */
1.201 markus 1893: ssh_packet_close(ssh);
1.112 markus 1894: cleanup_exit(255);
1.1 deraadt 1895: }
1896:
1.205 djm 1897: /*
1898: * Checks if there is any buffered output, and tries to write some of
1899: * the output.
1900: */
1901: int
1.201 markus 1902: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1903: {
1.201 markus 1904: struct session_state *state = ssh->state;
1905: int len = sshbuf_len(state->output);
1.222 markus 1906: int r;
1.97 deraadt 1907:
1.14 markus 1908: if (len > 0) {
1.222 markus 1909: len = write(state->connection_out,
1910: sshbuf_ptr(state->output), len);
1.156 djm 1911: if (len == -1) {
1912: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1913: return 0;
1914: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1915: }
1.222 markus 1916: if (len == 0)
1.205 djm 1917: return SSH_ERR_CONN_CLOSED;
1.201 markus 1918: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1919: return r;
1.14 markus 1920: }
1.205 djm 1921: return 0;
1.1 deraadt 1922: }
1923:
1.16 markus 1924: /*
1925: * Calls packet_write_poll repeatedly until all pending output data has been
1926: * written.
1927: */
1.205 djm 1928: int
1.201 markus 1929: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1930: {
1.56 millert 1931: fd_set *setp;
1.205 djm 1932: int ret, r, ms_remain = 0;
1.154 dtucker 1933: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1934: struct session_state *state = ssh->state;
1.56 millert 1935:
1.214 deraadt 1936: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1937: NFDBITS), sizeof(fd_mask));
1.201 markus 1938: if (setp == NULL)
1.205 djm 1939: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1940: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1941: free(setp);
1.215 djm 1942: return r;
1.216 gsoares 1943: }
1.201 markus 1944: while (ssh_packet_have_data_to_write(ssh)) {
1945: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1946: NFDBITS) * sizeof(fd_mask));
1.201 markus 1947: FD_SET(state->connection_out, setp);
1.154 dtucker 1948:
1.201 markus 1949: if (state->packet_timeout_ms > 0) {
1950: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1951: timeoutp = &timeout;
1952: }
1953: for (;;) {
1.201 markus 1954: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1955: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1956: monotime_tv(&start);
1.154 dtucker 1957: }
1.201 markus 1958: if ((ret = select(state->connection_out + 1,
1.161 andreas 1959: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1960: break;
1.161 andreas 1961: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1962: break;
1.201 markus 1963: if (state->packet_timeout_ms == -1)
1.154 dtucker 1964: continue;
1965: ms_subtract_diff(&start, &ms_remain);
1966: if (ms_remain <= 0) {
1967: ret = 0;
1968: break;
1969: }
1970: }
1971: if (ret == 0) {
1.205 djm 1972: free(setp);
1973: return SSH_ERR_CONN_TIMEOUT;
1974: }
1975: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1976: free(setp);
1977: return r;
1.154 dtucker 1978: }
1.14 markus 1979: }
1.186 djm 1980: free(setp);
1.205 djm 1981: return 0;
1.1 deraadt 1982: }
1983:
1984: /* Returns true if there is buffered data to write to the connection. */
1985:
1.2 provos 1986: int
1.201 markus 1987: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 1988: {
1.201 markus 1989: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 1990: }
1991:
1992: /* Returns true if there is not too much data to write to the connection. */
1993:
1.2 provos 1994: int
1.201 markus 1995: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 1996: {
1.201 markus 1997: if (ssh->state->interactive_mode)
1998: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 1999: else
1.201 markus 2000: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 2001: }
2002:
1.201 markus 2003: void
2004: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 2005: {
1.263 djm 2006: if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
1.101 markus 2007: return;
1.201 markus 2008: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 2009: case AF_INET:
2010: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 2011: if (setsockopt(ssh->state->connection_in,
1.173 djm 2012: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
2013: error("setsockopt IP_TOS %d: %.100s:",
2014: tos, strerror(errno));
2015: break;
2016: case AF_INET6:
2017: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 2018: if (setsockopt(ssh->state->connection_in,
1.173 djm 2019: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2020: error("setsockopt IPV6_TCLASS %d: %.100s:",
2021: tos, strerror(errno));
2022: break;
2023: }
1.101 markus 2024: }
2025:
1.1 deraadt 2026: /* Informs that the current session is interactive. Sets IP flags for that. */
2027:
1.2 provos 2028: void
1.201 markus 2029: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2030: {
1.201 markus 2031: struct session_state *state = ssh->state;
2032:
2033: if (state->set_interactive_called)
1.43 markus 2034: return;
1.201 markus 2035: state->set_interactive_called = 1;
1.1 deraadt 2036:
1.14 markus 2037: /* Record that we are in interactive mode. */
1.201 markus 2038: state->interactive_mode = interactive;
1.1 deraadt 2039:
1.19 markus 2040: /* Only set socket options if using a socket. */
1.201 markus 2041: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2042: return;
1.201 markus 2043: set_nodelay(state->connection_in);
2044: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2045: qos_bulk);
1.1 deraadt 2046: }
2047:
2048: /* Returns true if the current connection is interactive. */
2049:
1.2 provos 2050: int
1.201 markus 2051: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2052: {
1.201 markus 2053: return ssh->state->interactive_mode;
1.12 markus 2054: }
2055:
1.113 deraadt 2056: int
1.201 markus 2057: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2058: {
1.201 markus 2059: struct session_state *state = ssh->state;
2060:
2061: if (state->set_maxsize_called) {
1.106 itojun 2062: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2063: state->max_packet_size, s);
1.14 markus 2064: return -1;
2065: }
2066: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2067: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2068: return -1;
2069: }
1.201 markus 2070: state->set_maxsize_called = 1;
1.66 markus 2071: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2072: state->max_packet_size = s;
1.14 markus 2073: return s;
1.53 markus 2074: }
2075:
1.161 andreas 2076: int
1.201 markus 2077: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2078: {
1.201 markus 2079: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2080: }
2081:
2082: void
1.201 markus 2083: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2084: {
1.201 markus 2085: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2086: }
2087:
2088: u_int
1.201 markus 2089: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2090: {
1.201 markus 2091: return ssh->state->max_packet_size;
1.71 markus 2092: }
2093:
1.105 markus 2094: void
1.244 dtucker 2095: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2096: {
1.244 dtucker 2097: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2098: (unsigned int)seconds);
1.201 markus 2099: ssh->state->rekey_limit = bytes;
2100: ssh->state->rekey_interval = seconds;
1.184 dtucker 2101: }
2102:
2103: time_t
1.201 markus 2104: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2105: {
2106: time_t seconds;
2107:
1.201 markus 2108: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2109: monotime();
1.185 dtucker 2110: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2111: }
2112:
2113: void
1.201 markus 2114: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2115: {
1.201 markus 2116: ssh->state->server_side = 1;
1.278 djm 2117: ssh->kex->server = 1; /* XXX unify? */
1.118 markus 2118: }
2119:
2120: void
1.201 markus 2121: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2122: {
1.201 markus 2123: ssh->state->after_authentication = 1;
1.161 andreas 2124: }
2125:
2126: void *
1.201 markus 2127: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2128: {
1.201 markus 2129: return (void *)ssh->state->input;
1.161 andreas 2130: }
2131:
2132: void *
1.201 markus 2133: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2134: {
1.201 markus 2135: return (void *)ssh->state->output;
1.166 andreas 2136: }
2137:
1.196 markus 2138: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2139: static int
2140: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2141: {
1.239 djm 2142: int r;
1.196 markus 2143:
2144: debug("%s: called", __func__);
2145: /* This was set in net child, but is not visible in user child */
1.201 markus 2146: ssh->state->after_authentication = 1;
2147: ssh->state->rekeying = 0;
1.239 djm 2148: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2149: return r;
1.201 markus 2150: return 0;
2151: }
2152:
2153: /* Packet state (de-)serialization for privsep */
2154:
2155: /* turn kex into a blob for packet state serialization */
2156: static int
2157: kex_to_blob(struct sshbuf *m, struct kex *kex)
2158: {
2159: int r;
2160:
2161: if ((r = sshbuf_put_string(m, kex->session_id,
2162: kex->session_id_len)) != 0 ||
2163: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
1.269 djm 2164: (r = sshbuf_put_cstring(m, kex->hostkey_alg)) != 0 ||
1.201 markus 2165: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
1.269 djm 2166: (r = sshbuf_put_u32(m, kex->hostkey_nid)) != 0 ||
1.201 markus 2167: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2168: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2169: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
1.278 djm 2170: (r = sshbuf_put_stringb(m, kex->client_version)) != 0 ||
2171: (r = sshbuf_put_stringb(m, kex->server_version)) != 0 ||
2172: (r = sshbuf_put_u32(m, kex->flags)) != 0)
1.201 markus 2173: return r;
2174: return 0;
2175: }
2176:
2177: /* turn key exchange results into a blob for packet state serialization */
2178: static int
2179: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2180: {
2181: struct sshbuf *b;
2182: struct sshcipher_ctx *cc;
2183: struct sshcomp *comp;
2184: struct sshenc *enc;
2185: struct sshmac *mac;
2186: struct newkeys *newkey;
2187: int r;
2188:
2189: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2190: return SSH_ERR_INTERNAL_ERROR;
2191: enc = &newkey->enc;
2192: mac = &newkey->mac;
2193: comp = &newkey->comp;
1.235 djm 2194: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2195: ssh->state->receive_context;
1.201 markus 2196: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2197: return r;
2198: if ((b = sshbuf_new()) == NULL)
2199: return SSH_ERR_ALLOC_FAIL;
2200: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2201: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2202: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2203: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2204: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2205: goto out;
2206: if (cipher_authlen(enc->cipher) == 0) {
2207: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2208: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2209: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2210: goto out;
2211: }
2212: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2213: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2214: goto out;
2215: r = sshbuf_put_stringb(m, b);
2216: out:
1.221 mmcc 2217: sshbuf_free(b);
1.201 markus 2218: return r;
2219: }
2220:
2221: /* serialize packet state into a blob */
2222: int
2223: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2224: {
2225: struct session_state *state = ssh->state;
1.249 djm 2226: int r;
1.201 markus 2227:
1.249 djm 2228: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2229: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2230: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2231: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2232: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2233: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2234: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2235: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2236: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2237: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2238: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2239: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2240: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2241: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2242: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 2243: return r;
1.201 markus 2244:
2245: return 0;
2246: }
2247:
2248: /* restore key exchange results from blob for packet state de-serialization */
2249: static int
2250: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2251: {
2252: struct sshbuf *b = NULL;
2253: struct sshcomp *comp;
2254: struct sshenc *enc;
2255: struct sshmac *mac;
2256: struct newkeys *newkey = NULL;
2257: size_t keylen, ivlen, maclen;
2258: int r;
2259:
2260: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2261: r = SSH_ERR_ALLOC_FAIL;
2262: goto out;
2263: }
2264: if ((r = sshbuf_froms(m, &b)) != 0)
2265: goto out;
2266: #ifdef DEBUG_PK
2267: sshbuf_dump(b, stderr);
2268: #endif
2269: enc = &newkey->enc;
2270: mac = &newkey->mac;
2271: comp = &newkey->comp;
2272:
2273: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2274: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2275: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2276: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2277: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2278: goto out;
1.262 djm 2279: if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2280: r = SSH_ERR_INVALID_FORMAT;
2281: goto out;
2282: }
1.201 markus 2283: if (cipher_authlen(enc->cipher) == 0) {
2284: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2285: goto out;
2286: if ((r = mac_setup(mac, mac->name)) != 0)
2287: goto out;
2288: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2289: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2290: goto out;
2291: if (maclen > mac->key_len) {
2292: r = SSH_ERR_INVALID_FORMAT;
2293: goto out;
2294: }
2295: mac->key_len = maclen;
2296: }
2297: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2298: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2299: goto out;
2300: if (sshbuf_len(b) != 0) {
2301: r = SSH_ERR_INVALID_FORMAT;
2302: goto out;
2303: }
2304: enc->key_len = keylen;
2305: enc->iv_len = ivlen;
2306: ssh->kex->newkeys[mode] = newkey;
2307: newkey = NULL;
2308: r = 0;
2309: out:
1.219 mmcc 2310: free(newkey);
1.221 mmcc 2311: sshbuf_free(b);
1.201 markus 2312: return r;
2313: }
2314:
2315: /* restore kex from blob for packet state de-serialization */
2316: static int
2317: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2318: {
2319: struct kex *kex;
2320: int r;
2321:
1.278 djm 2322: if ((kex = kex_new()) == NULL)
2323: return SSH_ERR_ALLOC_FAIL;
1.201 markus 2324: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2325: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
1.269 djm 2326: (r = sshbuf_get_cstring(m, &kex->hostkey_alg, NULL)) != 0 ||
1.201 markus 2327: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
1.269 djm 2328: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_nid)) != 0 ||
1.201 markus 2329: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2330: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2331: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
1.278 djm 2332: (r = sshbuf_get_stringb(m, kex->client_version)) != 0 ||
2333: (r = sshbuf_get_stringb(m, kex->server_version)) != 0 ||
2334: (r = sshbuf_get_u32(m, &kex->flags)) != 0)
1.201 markus 2335: goto out;
2336: kex->server = 1;
2337: kex->done = 1;
2338: r = 0;
2339: out:
2340: if (r != 0 || kexp == NULL) {
1.278 djm 2341: kex_free(kex);
1.201 markus 2342: if (kexp != NULL)
2343: *kexp = NULL;
2344: } else {
1.278 djm 2345: kex_free(*kexp);
1.201 markus 2346: *kexp = kex;
2347: }
2348: return r;
2349: }
2350:
2351: /*
2352: * Restore packet state from content of blob 'm' (de-serialization).
2353: * Note that 'm' will be partially consumed on parsing or any other errors.
2354: */
2355: int
2356: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2357: {
2358: struct session_state *state = ssh->state;
1.254 djm 2359: const u_char *input, *output;
2360: size_t ilen, olen;
1.201 markus 2361: int r;
2362:
1.249 djm 2363: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2364: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2365: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2366: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2367: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2368: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2369: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2370: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2371: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2372: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2373: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2374: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2375: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2376: return r;
2377: /*
2378: * We set the time here so that in post-auth privsep slave we
2379: * count from the completion of the authentication.
2380: */
2381: state->rekey_time = monotime();
2382: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2383: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2384: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2385: return r;
1.201 markus 2386:
1.239 djm 2387: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2388: return r;
2389:
2390: sshbuf_reset(state->input);
2391: sshbuf_reset(state->output);
2392: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2393: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2394: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2395: (r = sshbuf_put(state->output, output, olen)) != 0)
2396: return r;
2397:
2398: if (sshbuf_len(m))
2399: return SSH_ERR_INVALID_FORMAT;
2400: debug3("%s: done", __func__);
2401: return 0;
2402: }
2403:
2404: /* NEW API */
2405:
2406: /* put data to the outgoing packet */
2407:
2408: int
2409: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2410: {
2411: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2412: }
2413:
2414: int
2415: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2416: {
2417: return sshbuf_putb(ssh->state->outgoing_packet, b);
2418: }
2419:
2420: int
2421: sshpkt_put_u8(struct ssh *ssh, u_char val)
2422: {
2423: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2424: }
2425:
2426: int
2427: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2428: {
2429: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2430: }
2431:
2432: int
2433: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2434: {
2435: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2436: }
2437:
2438: int
2439: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2440: {
2441: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2442: }
2443:
2444: int
2445: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2446: {
2447: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2448: }
2449:
2450: int
2451: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2452: {
2453: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2454: }
2455:
1.211 djm 2456: #ifdef WITH_OPENSSL
1.201 markus 2457: int
2458: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2459: {
2460: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2461: }
2462:
2463:
2464: int
2465: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2466: {
2467: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2468: }
1.211 djm 2469: #endif /* WITH_OPENSSL */
1.201 markus 2470:
2471: /* fetch data from the incoming packet */
2472:
2473: int
2474: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2475: {
2476: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2477: }
2478:
2479: int
2480: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2481: {
2482: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2483: }
2484:
2485: int
2486: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2487: {
2488: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2489: }
2490:
2491: int
2492: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2493: {
2494: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2495: }
2496:
2497: int
2498: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2499: {
2500: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2501: }
2502:
2503: int
2504: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2505: {
2506: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2507: }
2508:
2509: int
1.264 djm 2510: sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2511: {
2512: return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2513: }
2514:
2515: int
1.201 markus 2516: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2517: {
2518: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
1.282 djm 2519: }
2520:
2521: int
2522: sshpkt_getb_froms(struct ssh *ssh, struct sshbuf **valp)
2523: {
2524: return sshbuf_froms(ssh->state->incoming_packet, valp);
1.201 markus 2525: }
2526:
1.211 djm 2527: #ifdef WITH_OPENSSL
1.201 markus 2528: int
2529: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2530: {
2531: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2532: }
2533:
2534: int
1.281 djm 2535: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM **valp)
1.201 markus 2536: {
1.281 djm 2537: return sshbuf_get_bignum2(ssh->state->incoming_packet, valp);
1.201 markus 2538: }
1.211 djm 2539: #endif /* WITH_OPENSSL */
1.201 markus 2540:
2541: int
2542: sshpkt_get_end(struct ssh *ssh)
2543: {
2544: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2545: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2546: return 0;
2547: }
2548:
2549: const u_char *
2550: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2551: {
2552: if (lenp != NULL)
2553: *lenp = sshbuf_len(ssh->state->incoming_packet);
2554: return sshbuf_ptr(ssh->state->incoming_packet);
2555: }
2556:
2557: /* start a new packet */
2558:
2559: int
2560: sshpkt_start(struct ssh *ssh, u_char type)
2561: {
1.249 djm 2562: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2563:
2564: DBG(debug("packet_start[%d]", type));
1.249 djm 2565: memset(buf, 0, sizeof(buf));
2566: buf[sizeof(buf) - 1] = type;
1.201 markus 2567: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2568: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2569: }
2570:
1.242 markus 2571: static int
2572: ssh_packet_send_mux(struct ssh *ssh)
2573: {
2574: struct session_state *state = ssh->state;
2575: u_char type, *cp;
2576: size_t len;
2577: int r;
2578:
2579: if (ssh->kex)
2580: return SSH_ERR_INTERNAL_ERROR;
2581: len = sshbuf_len(state->outgoing_packet);
2582: if (len < 6)
2583: return SSH_ERR_INTERNAL_ERROR;
2584: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2585: type = cp[5];
2586: if (ssh_packet_log_type(type))
2587: debug3("%s: type %u", __func__, type);
2588: /* drop everything, but the connection protocol */
2589: if (type >= SSH2_MSG_CONNECTION_MIN &&
2590: type <= SSH2_MSG_CONNECTION_MAX) {
2591: POKE_U32(cp, len - 4);
2592: if ((r = sshbuf_putb(state->output,
2593: state->outgoing_packet)) != 0)
2594: return r;
2595: /* sshbuf_dump(state->output, stderr); */
2596: }
2597: sshbuf_reset(state->outgoing_packet);
1.264 djm 2598: return 0;
2599: }
2600:
2601: /*
2602: * 9.2. Ignored Data Message
2603: *
2604: * byte SSH_MSG_IGNORE
2605: * string data
2606: *
2607: * All implementations MUST understand (and ignore) this message at any
2608: * time (after receiving the protocol version). No implementation is
2609: * required to send them. This message can be used as an additional
2610: * protection measure against advanced traffic analysis techniques.
2611: */
2612: int
2613: sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2614: {
2615: u_int32_t rnd = 0;
2616: int r;
2617: u_int i;
2618:
2619: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2620: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2621: return r;
2622: for (i = 0; i < nbytes; i++) {
2623: if (i % 4 == 0)
2624: rnd = arc4random();
2625: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2626: return r;
2627: rnd >>= 8;
2628: }
1.242 markus 2629: return 0;
2630: }
2631:
1.201 markus 2632: /* send it */
2633:
2634: int
2635: sshpkt_send(struct ssh *ssh)
2636: {
1.242 markus 2637: if (ssh->state && ssh->state->mux)
2638: return ssh_packet_send_mux(ssh);
1.249 djm 2639: return ssh_packet_send2(ssh);
1.201 markus 2640: }
2641:
2642: int
2643: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2644: {
2645: char buf[1024];
2646: va_list args;
2647: int r;
2648:
2649: va_start(args, fmt);
2650: vsnprintf(buf, sizeof(buf), fmt, args);
2651: va_end(args);
2652:
1.249 djm 2653: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2654: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2655: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2656: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2657: (r = sshpkt_send(ssh)) != 0)
2658: return r;
1.201 markus 2659: return 0;
2660: }
2661:
2662: /* roundup current message to pad bytes */
2663: int
2664: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2665: {
2666: ssh->state->extra_pad = pad;
2667: return 0;
1.1 deraadt 2668: }
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