Annotation of src/usr.bin/ssh/packet.c, Revision 1.296
1.296 ! djm 1: /* $OpenBSD: packet.c,v 1.295 2020/07/01 16:28:31 markus Exp $ */
1.1 deraadt 2: /*
1.15 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.35 deraadt 6: * This file contains code implementing the packet protocol and communication
7: * with the other side. This same code is used both on client and server side.
1.29 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
1.29 markus 14: *
1.25 markus 15: *
16: * SSH2 packet format added by Markus Friedl.
1.69 markus 17: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.25 markus 18: *
1.35 deraadt 19: * Redistribution and use in source and binary forms, with or without
20: * modification, are permitted provided that the following conditions
21: * are met:
22: * 1. Redistributions of source code must retain the above copyright
23: * notice, this list of conditions and the following disclaimer.
24: * 2. Redistributions in binary form must reproduce the above copyright
25: * notice, this list of conditions and the following disclaimer in the
26: * documentation and/or other materials provided with the distribution.
27: *
28: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15 deraadt 38: */
1.1 deraadt 39:
1.142 deraadt 40: #include <sys/types.h>
1.105 markus 41: #include <sys/queue.h>
1.132 stevesk 42: #include <sys/socket.h>
1.138 stevesk 43: #include <sys/time.h>
1.132 stevesk 44: #include <netinet/in.h>
1.121 stevesk 45: #include <netinet/ip.h>
1.134 stevesk 46:
1.135 stevesk 47: #include <errno.h>
1.230 djm 48: #include <netdb.h>
1.134 stevesk 49: #include <stdarg.h>
1.141 stevesk 50: #include <stdio.h>
1.140 stevesk 51: #include <stdlib.h>
1.137 stevesk 52: #include <string.h>
1.136 stevesk 53: #include <unistd.h>
1.203 deraadt 54: #include <limits.h>
1.278 djm 55: #include <poll.h>
1.142 deraadt 56: #include <signal.h>
1.184 dtucker 57: #include <time.h>
1.1 deraadt 58:
1.288 dtucker 59: #ifdef WITH_ZLIB
1.201 markus 60: #include <zlib.h>
1.288 dtucker 61: #endif
1.201 markus 62:
1.1 deraadt 63: #include "xmalloc.h"
1.25 markus 64: #include "compat.h"
65: #include "ssh2.h"
1.37 markus 66: #include "cipher.h"
1.201 markus 67: #include "sshkey.h"
1.25 markus 68: #include "kex.h"
1.200 markus 69: #include "digest.h"
1.50 markus 70: #include "mac.h"
1.46 markus 71: #include "log.h"
72: #include "canohost.h"
1.87 stevesk 73: #include "misc.h"
1.198 millert 74: #include "channels.h"
1.95 markus 75: #include "ssh.h"
1.201 markus 76: #include "packet.h"
1.197 djm 77: #include "ssherr.h"
1.201 markus 78: #include "sshbuf.h"
1.25 markus 79:
80: #ifdef PACKET_DEBUG
81: #define DBG(x) x
82: #else
83: #define DBG(x)
84: #endif
85:
1.159 markus 86: #define PACKET_MAX_SIZE (256 * 1024)
87:
1.161 andreas 88: struct packet_state {
89: u_int32_t seqnr;
90: u_int32_t packets;
91: u_int64_t blocks;
92: u_int64_t bytes;
93: };
94:
95: struct packet {
96: TAILQ_ENTRY(packet) next;
97: u_char type;
1.201 markus 98: struct sshbuf *payload;
1.161 andreas 99: };
100:
101: struct session_state {
102: /*
103: * This variable contains the file descriptors used for
104: * communicating with the other side. connection_in is used for
105: * reading; connection_out for writing. These can be the same
106: * descriptor, in which case it is assumed to be a socket.
107: */
108: int connection_in;
109: int connection_out;
110:
111: /* Protocol flags for the remote side. */
112: u_int remote_protocol_flags;
1.1 deraadt 113:
1.161 andreas 114: /* Encryption context for receiving data. Only used for decryption. */
1.235 djm 115: struct sshcipher_ctx *receive_context;
1.1 deraadt 116:
1.161 andreas 117: /* Encryption context for sending data. Only used for encryption. */
1.235 djm 118: struct sshcipher_ctx *send_context;
1.14 markus 119:
1.161 andreas 120: /* Buffer for raw input data from the socket. */
1.201 markus 121: struct sshbuf *input;
1.1 deraadt 122:
1.161 andreas 123: /* Buffer for raw output data going to the socket. */
1.201 markus 124: struct sshbuf *output;
1.1 deraadt 125:
1.161 andreas 126: /* Buffer for the partial outgoing packet being constructed. */
1.201 markus 127: struct sshbuf *outgoing_packet;
1.1 deraadt 128:
1.161 andreas 129: /* Buffer for the incoming packet currently being processed. */
1.201 markus 130: struct sshbuf *incoming_packet;
1.1 deraadt 131:
1.161 andreas 132: /* Scratch buffer for packet compression/decompression. */
1.201 markus 133: struct sshbuf *compression_buffer;
134:
1.288 dtucker 135: #ifdef WITH_ZLIB
1.201 markus 136: /* Incoming/outgoing compression dictionaries */
137: z_stream compression_in_stream;
138: z_stream compression_out_stream;
1.288 dtucker 139: #endif
1.201 markus 140: int compression_in_started;
141: int compression_out_started;
142: int compression_in_failures;
143: int compression_out_failures;
1.1 deraadt 144:
1.161 andreas 145: /* default maximum packet size */
146: u_int max_packet_size;
1.1 deraadt 147:
1.161 andreas 148: /* Flag indicating whether this module has been initialized. */
149: int initialized;
1.12 markus 150:
1.161 andreas 151: /* Set to true if the connection is interactive. */
152: int interactive_mode;
1.1 deraadt 153:
1.161 andreas 154: /* Set to true if we are the server side. */
155: int server_side;
1.1 deraadt 156:
1.161 andreas 157: /* Set to true if we are authenticated. */
158: int after_authentication;
1.118 markus 159:
1.161 andreas 160: int keep_alive_timeouts;
1.118 markus 161:
1.161 andreas 162: /* The maximum time that we will wait to send or receive a packet */
163: int packet_timeout_ms;
1.151 dtucker 164:
1.161 andreas 165: /* Session key information for Encryption and MAC */
1.201 markus 166: struct newkeys *newkeys[MODE_MAX];
1.161 andreas 167: struct packet_state p_read, p_send;
1.154 dtucker 168:
1.184 dtucker 169: /* Volume-based rekeying */
1.224 dtucker 170: u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
1.105 markus 171:
1.184 dtucker 172: /* Time-based rekeying */
1.208 markus 173: u_int32_t rekey_interval; /* how often in seconds */
1.184 dtucker 174: time_t rekey_time; /* time of last rekeying */
175:
1.161 andreas 176: /* roundup current message to extra_pad bytes */
177: u_char extra_pad;
1.95 markus 178:
1.161 andreas 179: /* XXX discard incoming data after MAC error */
180: u_int packet_discard;
1.234 markus 181: size_t packet_discard_mac_already;
1.201 markus 182: struct sshmac *packet_discard_mac;
1.71 markus 183:
1.161 andreas 184: /* Used in packet_read_poll2() */
185: u_int packlen;
1.159 markus 186:
1.165 andreas 187: /* Used in packet_send2 */
188: int rekeying;
189:
1.242 markus 190: /* Used in ssh_packet_send_mux() */
191: int mux;
192:
1.165 andreas 193: /* Used in packet_set_interactive */
194: int set_interactive_called;
195:
196: /* Used in packet_set_maxsize */
197: int set_maxsize_called;
198:
1.201 markus 199: /* One-off warning about weak ciphers */
200: int cipher_warning_done;
201:
1.243 djm 202: /* Hook for fuzzing inbound packets */
203: ssh_packet_hook_fn *hook_in;
204: void *hook_in_ctx;
205:
1.161 andreas 206: TAILQ_HEAD(, packet) outgoing;
1.105 markus 207: };
1.161 andreas 208:
1.201 markus 209: struct ssh *
210: ssh_alloc_session_state(void)
1.161 andreas 211: {
1.201 markus 212: struct ssh *ssh = NULL;
213: struct session_state *state = NULL;
1.161 andreas 214:
1.201 markus 215: if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
216: (state = calloc(1, sizeof(*state))) == NULL ||
1.278 djm 217: (ssh->kex = kex_new()) == NULL ||
1.201 markus 218: (state->input = sshbuf_new()) == NULL ||
219: (state->output = sshbuf_new()) == NULL ||
220: (state->outgoing_packet = sshbuf_new()) == NULL ||
221: (state->incoming_packet = sshbuf_new()) == NULL)
222: goto fail;
223: TAILQ_INIT(&state->outgoing);
1.202 markus 224: TAILQ_INIT(&ssh->private_keys);
225: TAILQ_INIT(&ssh->public_keys);
1.201 markus 226: state->connection_in = -1;
227: state->connection_out = -1;
228: state->max_packet_size = 32768;
229: state->packet_timeout_ms = -1;
230: state->p_send.packets = state->p_read.packets = 0;
231: state->initialized = 1;
232: /*
233: * ssh_packet_send2() needs to queue packets until
234: * we've done the initial key exchange.
235: */
236: state->rekeying = 1;
237: ssh->state = state;
238: return ssh;
239: fail:
1.278 djm 240: if (ssh) {
241: kex_free(ssh->kex);
242: free(ssh);
243: }
1.201 markus 244: if (state) {
245: sshbuf_free(state->input);
246: sshbuf_free(state->output);
247: sshbuf_free(state->incoming_packet);
248: sshbuf_free(state->outgoing_packet);
249: free(state);
250: }
251: return NULL;
1.161 andreas 252: }
1.105 markus 253:
1.243 djm 254: void
255: ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
256: {
257: ssh->state->hook_in = hook;
258: ssh->state->hook_in_ctx = ctx;
259: }
260:
1.228 djm 261: /* Returns nonzero if rekeying is in progress */
262: int
263: ssh_packet_is_rekeying(struct ssh *ssh)
264: {
1.292 markus 265: return ssh->state->rekeying ||
266: (ssh->kex != NULL && ssh->kex->done == 0);
1.228 djm 267: }
268:
1.16 markus 269: /*
1.253 naddy 270: * Sets the descriptors used for communication.
1.16 markus 271: */
1.201 markus 272: struct ssh *
273: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1 deraadt 274: {
1.201 markus 275: struct session_state *state;
276: const struct sshcipher *none = cipher_by_name("none");
1.197 djm 277: int r;
1.97 deraadt 278:
1.205 djm 279: if (none == NULL) {
280: error("%s: cannot load cipher 'none'", __func__);
281: return NULL;
282: }
1.201 markus 283: if (ssh == NULL)
284: ssh = ssh_alloc_session_state();
1.205 djm 285: if (ssh == NULL) {
1.285 dtucker 286: error("%s: could not allocate state", __func__);
1.205 djm 287: return NULL;
288: }
1.201 markus 289: state = ssh->state;
290: state->connection_in = fd_in;
291: state->connection_out = fd_out;
292: if ((r = cipher_init(&state->send_context, none,
1.197 djm 293: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201 markus 294: (r = cipher_init(&state->receive_context, none,
1.205 djm 295: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
296: error("%s: cipher_init failed: %s", __func__, ssh_err(r));
1.230 djm 297: free(ssh); /* XXX need ssh_free_session_state? */
1.205 djm 298: return NULL;
299: }
1.201 markus 300: state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
1.207 djm 301: /*
302: * Cache the IP address of the remote connection for use in error
303: * messages that might be generated after the connection has closed.
304: */
305: (void)ssh_remote_ipaddr(ssh);
1.201 markus 306: return ssh;
1.1 deraadt 307: }
308:
1.154 dtucker 309: void
1.201 markus 310: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 311: {
1.201 markus 312: struct session_state *state = ssh->state;
313:
1.174 djm 314: if (timeout <= 0 || count <= 0) {
1.201 markus 315: state->packet_timeout_ms = -1;
1.154 dtucker 316: return;
317: }
318: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 319: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 320: else
1.201 markus 321: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 322: }
323:
1.242 markus 324: void
325: ssh_packet_set_mux(struct ssh *ssh)
326: {
327: ssh->state->mux = 1;
328: ssh->state->rekeying = 0;
1.292 markus 329: kex_free(ssh->kex);
330: ssh->kex = NULL;
1.242 markus 331: }
332:
333: int
334: ssh_packet_get_mux(struct ssh *ssh)
335: {
336: return ssh->state->mux;
337: }
338:
1.201 markus 339: int
1.245 djm 340: ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
341: {
342: va_list args;
343: int r;
344:
345: free(ssh->log_preamble);
346: if (fmt == NULL)
347: ssh->log_preamble = NULL;
348: else {
349: va_start(args, fmt);
350: r = vasprintf(&ssh->log_preamble, fmt, args);
351: va_end(args);
352: if (r < 0 || ssh->log_preamble == NULL)
353: return SSH_ERR_ALLOC_FAIL;
354: }
355: return 0;
356: }
357:
358: int
1.201 markus 359: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 360: {
1.201 markus 361: struct session_state *state = ssh->state;
362: int r;
363:
364: if (state->packet_discard_mac) {
1.159 markus 365: char buf[1024];
1.234 markus 366: size_t dlen = PACKET_MAX_SIZE;
1.201 markus 367:
1.234 markus 368: if (dlen > state->packet_discard_mac_already)
369: dlen -= state->packet_discard_mac_already;
1.159 markus 370: memset(buf, 'a', sizeof(buf));
1.234 markus 371: while (sshbuf_len(state->incoming_packet) < dlen)
1.201 markus 372: if ((r = sshbuf_put(state->incoming_packet, buf,
373: sizeof(buf))) != 0)
374: return r;
375: (void) mac_compute(state->packet_discard_mac,
376: state->p_read.seqnr,
1.234 markus 377: sshbuf_ptr(state->incoming_packet), dlen,
1.201 markus 378: NULL, 0);
1.159 markus 379: }
1.220 djm 380: logit("Finished discarding for %.200s port %d",
381: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 382: return SSH_ERR_MAC_INVALID;
1.159 markus 383: }
384:
1.201 markus 385: static int
386: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
1.234 markus 387: struct sshmac *mac, size_t mac_already, u_int discard)
1.159 markus 388: {
1.201 markus 389: struct session_state *state = ssh->state;
390: int r;
391:
392: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
393: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
394: return r;
395: return SSH_ERR_MAC_INVALID;
396: }
1.234 markus 397: /*
398: * Record number of bytes over which the mac has already
399: * been computed in order to minimize timing attacks.
400: */
401: if (mac && mac->enabled) {
1.201 markus 402: state->packet_discard_mac = mac;
1.234 markus 403: state->packet_discard_mac_already = mac_already;
404: }
405: if (sshbuf_len(state->input) >= discard)
406: return ssh_packet_stop_discard(ssh);
1.201 markus 407: state->packet_discard = discard - sshbuf_len(state->input);
408: return 0;
1.159 markus 409: }
410:
1.19 markus 411: /* Returns 1 if remote host is connected via socket, 0 if not. */
412:
413: int
1.201 markus 414: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 415: {
1.271 djm 416: struct session_state *state;
1.19 markus 417: struct sockaddr_storage from, to;
418: socklen_t fromlen, tolen;
419:
1.271 djm 420: if (ssh == NULL || ssh->state == NULL)
421: return 0;
422:
423: state = ssh->state;
1.230 djm 424: if (state->connection_in == -1 || state->connection_out == -1)
425: return 0;
1.19 markus 426: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 427: if (state->connection_in == state->connection_out)
1.19 markus 428: return 1;
429: fromlen = sizeof(from);
430: memset(&from, 0, sizeof(from));
1.201 markus 431: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.286 deraadt 432: &fromlen) == -1)
1.19 markus 433: return 0;
434: tolen = sizeof(to);
435: memset(&to, 0, sizeof(to));
1.201 markus 436: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.286 deraadt 437: &tolen) == -1)
1.19 markus 438: return 0;
439: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
440: return 0;
441: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
442: return 0;
443: return 1;
444: }
445:
1.91 markus 446: void
1.201 markus 447: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 448: {
1.201 markus 449: if (ibytes)
450: *ibytes = ssh->state->p_read.bytes;
451: if (obytes)
452: *obytes = ssh->state->p_send.bytes;
1.91 markus 453: }
1.125 deraadt 454:
1.91 markus 455: int
1.201 markus 456: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 457: {
458: struct sockaddr_storage to;
1.21 deraadt 459: socklen_t tolen = sizeof(to);
1.19 markus 460:
461: memset(&to, 0, sizeof(to));
1.201 markus 462: if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
1.286 deraadt 463: &tolen) == -1)
1.19 markus 464: return 0;
1.173 djm 465: return to.ss_family;
1.19 markus 466: }
467:
1.1 deraadt 468: /* Sets the connection into non-blocking mode. */
469:
1.2 provos 470: void
1.201 markus 471: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 472: {
1.14 markus 473: /* Set the socket into non-blocking mode. */
1.201 markus 474: set_nonblock(ssh->state->connection_in);
1.14 markus 475:
1.201 markus 476: if (ssh->state->connection_out != ssh->state->connection_in)
477: set_nonblock(ssh->state->connection_out);
1.1 deraadt 478: }
479:
480: /* Returns the socket used for reading. */
481:
1.2 provos 482: int
1.201 markus 483: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 484: {
1.201 markus 485: return ssh->state->connection_in;
1.1 deraadt 486: }
487:
488: /* Returns the descriptor used for writing. */
489:
1.2 provos 490: int
1.201 markus 491: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 492: {
1.201 markus 493: return ssh->state->connection_out;
494: }
495:
496: /*
497: * Returns the IP-address of the remote host as a string. The returned
498: * string must not be freed.
499: */
500:
501: const char *
502: ssh_remote_ipaddr(struct ssh *ssh)
503: {
1.271 djm 504: int sock;
1.220 djm 505:
1.201 markus 506: /* Check whether we have cached the ipaddr. */
1.220 djm 507: if (ssh->remote_ipaddr == NULL) {
508: if (ssh_packet_connection_is_on_socket(ssh)) {
1.271 djm 509: sock = ssh->state->connection_in;
1.220 djm 510: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 djm 511: ssh->remote_port = get_peer_port(sock);
512: ssh->local_ipaddr = get_local_ipaddr(sock);
513: ssh->local_port = get_local_port(sock);
1.220 djm 514: } else {
1.287 tobhe 515: ssh->remote_ipaddr = xstrdup("UNKNOWN");
1.230 djm 516: ssh->remote_port = 65535;
1.287 tobhe 517: ssh->local_ipaddr = xstrdup("UNKNOWN");
1.230 djm 518: ssh->local_port = 65535;
1.220 djm 519: }
520: }
1.201 markus 521: return ssh->remote_ipaddr;
1.1 deraadt 522: }
523:
1.220 djm 524: /* Returns the port number of the remote host. */
525:
526: int
527: ssh_remote_port(struct ssh *ssh)
528: {
529: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
530: return ssh->remote_port;
1.230 djm 531: }
532:
533: /*
534: * Returns the IP-address of the local host as a string. The returned
535: * string must not be freed.
536: */
537:
538: const char *
539: ssh_local_ipaddr(struct ssh *ssh)
540: {
541: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
542: return ssh->local_ipaddr;
543: }
544:
545: /* Returns the port number of the local host. */
546:
547: int
548: ssh_local_port(struct ssh *ssh)
549: {
550: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
551: return ssh->local_port;
1.266 djm 552: }
553:
554: /* Returns the routing domain of the input socket, or NULL if unavailable */
555: const char *
556: ssh_packet_rdomain_in(struct ssh *ssh)
557: {
558: if (ssh->rdomain_in != NULL)
559: return ssh->rdomain_in;
560: if (!ssh_packet_connection_is_on_socket(ssh))
561: return NULL;
562: ssh->rdomain_in = get_rdomain(ssh->state->connection_in);
563: return ssh->rdomain_in;
1.220 djm 564: }
565:
1.1 deraadt 566: /* Closes the connection and clears and frees internal data structures. */
567:
1.257 markus 568: static void
569: ssh_packet_close_internal(struct ssh *ssh, int do_close)
1.1 deraadt 570: {
1.201 markus 571: struct session_state *state = ssh->state;
572: u_int mode;
573:
574: if (!state->initialized)
1.14 markus 575: return;
1.201 markus 576: state->initialized = 0;
1.257 markus 577: if (do_close) {
578: if (state->connection_in == state->connection_out) {
579: close(state->connection_out);
580: } else {
581: close(state->connection_in);
582: close(state->connection_out);
583: }
1.14 markus 584: }
1.201 markus 585: sshbuf_free(state->input);
586: sshbuf_free(state->output);
587: sshbuf_free(state->outgoing_packet);
588: sshbuf_free(state->incoming_packet);
1.257 markus 589: for (mode = 0; mode < MODE_MAX; mode++) {
590: kex_free_newkeys(state->newkeys[mode]); /* current keys */
591: state->newkeys[mode] = NULL;
592: ssh_clear_newkeys(ssh, mode); /* next keys */
593: }
1.288 dtucker 594: #ifdef WITH_ZLIB
1.289 dtucker 595: /* compression state is in shared mem, so we can only release it once */
1.257 markus 596: if (do_close && state->compression_buffer) {
1.201 markus 597: sshbuf_free(state->compression_buffer);
598: if (state->compression_out_started) {
599: z_streamp stream = &state->compression_out_stream;
600: debug("compress outgoing: "
601: "raw data %llu, compressed %llu, factor %.2f",
602: (unsigned long long)stream->total_in,
603: (unsigned long long)stream->total_out,
604: stream->total_in == 0 ? 0.0 :
605: (double) stream->total_out / stream->total_in);
606: if (state->compression_out_failures == 0)
607: deflateEnd(stream);
608: }
609: if (state->compression_in_started) {
1.260 dtucker 610: z_streamp stream = &state->compression_in_stream;
1.201 markus 611: debug("compress incoming: "
612: "raw data %llu, compressed %llu, factor %.2f",
613: (unsigned long long)stream->total_out,
614: (unsigned long long)stream->total_in,
615: stream->total_out == 0 ? 0.0 :
616: (double) stream->total_in / stream->total_out);
617: if (state->compression_in_failures == 0)
618: inflateEnd(stream);
619: }
1.14 markus 620: }
1.288 dtucker 621: #endif /* WITH_ZLIB */
1.235 djm 622: cipher_free(state->send_context);
623: cipher_free(state->receive_context);
624: state->send_context = state->receive_context = NULL;
1.257 markus 625: if (do_close) {
1.277 djm 626: free(ssh->local_ipaddr);
627: ssh->local_ipaddr = NULL;
1.257 markus 628: free(ssh->remote_ipaddr);
629: ssh->remote_ipaddr = NULL;
630: free(ssh->state);
631: ssh->state = NULL;
1.295 markus 632: kex_free(ssh->kex);
633: ssh->kex = NULL;
1.257 markus 634: }
635: }
636:
637: void
638: ssh_packet_close(struct ssh *ssh)
639: {
640: ssh_packet_close_internal(ssh, 1);
641: }
642:
643: void
644: ssh_packet_clear_keys(struct ssh *ssh)
645: {
646: ssh_packet_close_internal(ssh, 0);
1.1 deraadt 647: }
648:
649: /* Sets remote side protocol flags. */
650:
1.2 provos 651: void
1.201 markus 652: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 653: {
1.201 markus 654: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 655: }
656:
657: /* Returns the remote protocol flags set earlier by the above function. */
658:
1.40 markus 659: u_int
1.201 markus 660: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 661: {
1.201 markus 662: return ssh->state->remote_protocol_flags;
1.1 deraadt 663: }
664:
1.16 markus 665: /*
666: * Starts packet compression from the next packet on in both directions.
667: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
668: */
1.1 deraadt 669:
1.201 markus 670: static int
671: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 672: {
1.201 markus 673: if (!ssh->state->compression_buffer &&
674: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
675: return SSH_ERR_ALLOC_FAIL;
676: return 0;
1.60 markus 677: }
678:
1.288 dtucker 679: #ifdef WITH_ZLIB
1.201 markus 680: static int
681: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 682: {
1.201 markus 683: if (level < 1 || level > 9)
684: return SSH_ERR_INVALID_ARGUMENT;
685: debug("Enabling compression at level %d.", level);
686: if (ssh->state->compression_out_started == 1)
687: deflateEnd(&ssh->state->compression_out_stream);
688: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
689: case Z_OK:
690: ssh->state->compression_out_started = 1;
691: break;
692: case Z_MEM_ERROR:
693: return SSH_ERR_ALLOC_FAIL;
694: default:
695: return SSH_ERR_INTERNAL_ERROR;
696: }
697: return 0;
1.1 deraadt 698: }
699:
1.201 markus 700: static int
701: start_compression_in(struct ssh *ssh)
702: {
703: if (ssh->state->compression_in_started == 1)
704: inflateEnd(&ssh->state->compression_in_stream);
705: switch (inflateInit(&ssh->state->compression_in_stream)) {
706: case Z_OK:
707: ssh->state->compression_in_started = 1;
708: break;
709: case Z_MEM_ERROR:
710: return SSH_ERR_ALLOC_FAIL;
711: default:
712: return SSH_ERR_INTERNAL_ERROR;
713: }
714: return 0;
1.95 markus 715: }
716:
1.201 markus 717: /* XXX remove need for separate compression buffer */
718: static int
719: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 720: {
1.201 markus 721: u_char buf[4096];
722: int r, status;
723:
724: if (ssh->state->compression_out_started != 1)
725: return SSH_ERR_INTERNAL_ERROR;
726:
727: /* This case is not handled below. */
728: if (sshbuf_len(in) == 0)
729: return 0;
730:
731: /* Input is the contents of the input buffer. */
732: if ((ssh->state->compression_out_stream.next_in =
733: sshbuf_mutable_ptr(in)) == NULL)
734: return SSH_ERR_INTERNAL_ERROR;
735: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
736:
737: /* Loop compressing until deflate() returns with avail_out != 0. */
738: do {
739: /* Set up fixed-size output buffer. */
740: ssh->state->compression_out_stream.next_out = buf;
741: ssh->state->compression_out_stream.avail_out = sizeof(buf);
742:
743: /* Compress as much data into the buffer as possible. */
744: status = deflate(&ssh->state->compression_out_stream,
745: Z_PARTIAL_FLUSH);
746: switch (status) {
747: case Z_MEM_ERROR:
748: return SSH_ERR_ALLOC_FAIL;
749: case Z_OK:
750: /* Append compressed data to output_buffer. */
751: if ((r = sshbuf_put(out, buf, sizeof(buf) -
752: ssh->state->compression_out_stream.avail_out)) != 0)
753: return r;
754: break;
755: case Z_STREAM_ERROR:
756: default:
757: ssh->state->compression_out_failures++;
758: return SSH_ERR_INVALID_FORMAT;
759: }
760: } while (ssh->state->compression_out_stream.avail_out == 0);
761: return 0;
1.1 deraadt 762: }
763:
1.201 markus 764: static int
765: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 766: {
1.201 markus 767: u_char buf[4096];
768: int r, status;
1.1 deraadt 769:
1.201 markus 770: if (ssh->state->compression_in_started != 1)
771: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 772:
1.201 markus 773: if ((ssh->state->compression_in_stream.next_in =
774: sshbuf_mutable_ptr(in)) == NULL)
775: return SSH_ERR_INTERNAL_ERROR;
776: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 777:
1.201 markus 778: for (;;) {
779: /* Set up fixed-size output buffer. */
780: ssh->state->compression_in_stream.next_out = buf;
781: ssh->state->compression_in_stream.avail_out = sizeof(buf);
782:
783: status = inflate(&ssh->state->compression_in_stream,
784: Z_PARTIAL_FLUSH);
785: switch (status) {
786: case Z_OK:
787: if ((r = sshbuf_put(out, buf, sizeof(buf) -
788: ssh->state->compression_in_stream.avail_out)) != 0)
789: return r;
790: break;
791: case Z_BUF_ERROR:
792: /*
793: * Comments in zlib.h say that we should keep calling
794: * inflate() until we get an error. This appears to
795: * be the error that we get.
796: */
797: return 0;
798: case Z_DATA_ERROR:
799: return SSH_ERR_INVALID_FORMAT;
800: case Z_MEM_ERROR:
801: return SSH_ERR_ALLOC_FAIL;
802: case Z_STREAM_ERROR:
803: default:
804: ssh->state->compression_in_failures++;
805: return SSH_ERR_INTERNAL_ERROR;
806: }
807: }
808: /* NOTREACHED */
1.170 djm 809: }
1.288 dtucker 810:
811: #else /* WITH_ZLIB */
812:
813: static int
814: start_compression_out(struct ssh *ssh, int level)
815: {
816: return SSH_ERR_INTERNAL_ERROR;
817: }
818:
819: static int
820: start_compression_in(struct ssh *ssh)
821: {
822: return SSH_ERR_INTERNAL_ERROR;
823: }
824:
825: static int
826: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
827: {
828: return SSH_ERR_INTERNAL_ERROR;
829: }
830:
831: static int
832: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
833: {
834: return SSH_ERR_INTERNAL_ERROR;
835: }
836: #endif /* WITH_ZLIB */
1.170 djm 837:
1.257 markus 838: void
839: ssh_clear_newkeys(struct ssh *ssh, int mode)
840: {
1.259 djm 841: if (ssh->kex && ssh->kex->newkeys[mode]) {
1.257 markus 842: kex_free_newkeys(ssh->kex->newkeys[mode]);
843: ssh->kex->newkeys[mode] = NULL;
844: }
845: }
846:
1.201 markus 847: int
848: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 849: {
1.201 markus 850: struct session_state *state = ssh->state;
851: struct sshenc *enc;
852: struct sshmac *mac;
853: struct sshcomp *comp;
1.235 djm 854: struct sshcipher_ctx **ccp;
1.236 markus 855: struct packet_state *ps;
1.105 markus 856: u_int64_t *max_blocks;
1.259 djm 857: const char *wmsg;
1.197 djm 858: int r, crypt_type;
1.283 djm 859: const char *dir = mode == MODE_OUT ? "out" : "in";
1.57 markus 860:
1.100 markus 861: debug2("set_newkeys: mode %d", mode);
1.57 markus 862:
1.88 markus 863: if (mode == MODE_OUT) {
1.235 djm 864: ccp = &state->send_context;
1.115 avsm 865: crypt_type = CIPHER_ENCRYPT;
1.236 markus 866: ps = &state->p_send;
1.201 markus 867: max_blocks = &state->max_blocks_out;
1.88 markus 868: } else {
1.235 djm 869: ccp = &state->receive_context;
1.115 avsm 870: crypt_type = CIPHER_DECRYPT;
1.236 markus 871: ps = &state->p_read;
1.201 markus 872: max_blocks = &state->max_blocks_in;
1.88 markus 873: }
1.201 markus 874: if (state->newkeys[mode] != NULL) {
1.283 djm 875: debug("%s: rekeying %s, input %llu bytes %llu blocks, "
876: "output %llu bytes %llu blocks", __func__, dir,
1.257 markus 877: (unsigned long long)state->p_read.bytes,
878: (unsigned long long)state->p_read.blocks,
879: (unsigned long long)state->p_send.bytes,
880: (unsigned long long)state->p_send.blocks);
881: kex_free_newkeys(state->newkeys[mode]);
882: state->newkeys[mode] = NULL;
1.57 markus 883: }
1.236 markus 884: /* note that both bytes and the seqnr are not reset */
885: ps->packets = ps->blocks = 0;
1.201 markus 886: /* move newkeys from kex to state */
887: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
888: return SSH_ERR_INTERNAL_ERROR;
889: ssh->kex->newkeys[mode] = NULL;
890: enc = &state->newkeys[mode]->enc;
891: mac = &state->newkeys[mode]->mac;
892: comp = &state->newkeys[mode]->comp;
893: if (cipher_authlen(enc->cipher) == 0) {
894: if ((r = mac_init(mac)) != 0)
895: return r;
896: }
897: mac->enabled = 1;
1.283 djm 898: DBG(debug("%s: cipher_init_context: %s", __func__, dir));
1.279 djm 899: cipher_free(*ccp);
900: *ccp = NULL;
1.235 djm 901: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 902: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 903: return r;
904: if (!state->cipher_warning_done &&
1.235 djm 905: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 906: error("Warning: %s", wmsg);
907: state->cipher_warning_done = 1;
908: }
1.91 markus 909: /* Deleting the keys does not gain extra security */
1.192 djm 910: /* explicit_bzero(enc->iv, enc->block_size);
911: explicit_bzero(enc->key, enc->key_len);
912: explicit_bzero(mac->key, mac->key_len); */
1.275 sf 913: if ((comp->type == COMP_ZLIB ||
914: (comp->type == COMP_DELAYED &&
915: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 916: if ((r = ssh_packet_init_compression(ssh)) < 0)
917: return r;
918: if (mode == MODE_OUT) {
919: if ((r = start_compression_out(ssh, 6)) != 0)
920: return r;
921: } else {
922: if ((r = start_compression_in(ssh)) != 0)
923: return r;
924: }
1.57 markus 925: comp->enabled = 1;
926: }
1.109 markus 927: /*
928: * The 2^(blocksize*2) limit is too expensive for 3DES,
1.254 djm 929: * so enforce a 1GB limit for small blocksizes.
1.261 dtucker 930: * See RFC4344 section 3.2.
1.109 markus 931: */
932: if (enc->block_size >= 16)
933: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
934: else
935: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 936: if (state->rekey_limit)
1.237 deraadt 937: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 938: state->rekey_limit / enc->block_size);
1.283 djm 939: debug("rekey %s after %llu blocks", dir,
940: (unsigned long long)*max_blocks);
1.201 markus 941: return 0;
1.57 markus 942: }
943:
1.228 djm 944: #define MAX_PACKETS (1U<<31)
945: static int
946: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
947: {
948: struct session_state *state = ssh->state;
949: u_int32_t out_blocks;
950:
951: /* XXX client can't cope with rekeying pre-auth */
952: if (!state->after_authentication)
953: return 0;
954:
955: /* Haven't keyed yet or KEX in progress. */
1.278 djm 956: if (ssh_packet_is_rekeying(ssh))
1.228 djm 957: return 0;
958:
959: /* Peer can't rekey */
960: if (ssh->compat & SSH_BUG_NOREKEY)
961: return 0;
962:
963: /*
964: * Permit one packet in or out per rekey - this allows us to
965: * make progress when rekey limits are very small.
966: */
967: if (state->p_send.packets == 0 && state->p_read.packets == 0)
968: return 0;
969:
970: /* Time-based rekeying */
971: if (state->rekey_interval != 0 &&
1.244 dtucker 972: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 973: return 1;
974:
1.261 dtucker 975: /*
976: * Always rekey when MAX_PACKETS sent in either direction
977: * As per RFC4344 section 3.1 we do this after 2^31 packets.
978: */
1.228 djm 979: if (state->p_send.packets > MAX_PACKETS ||
980: state->p_read.packets > MAX_PACKETS)
981: return 1;
982:
983: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 984: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 985: state->newkeys[MODE_OUT]->enc.block_size);
986: return (state->max_blocks_out &&
987: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
988: (state->max_blocks_in &&
989: (state->p_read.blocks > state->max_blocks_in));
990: }
991:
1.16 markus 992: /*
1.118 markus 993: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 994: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 995: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
996: */
1.201 markus 997: static int
998: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 999: {
1.201 markus 1000: struct session_state *state = ssh->state;
1001: struct sshcomp *comp = NULL;
1002: int r, mode;
1.118 markus 1003:
1004: /*
1005: * Remember that we are past the authentication step, so rekeying
1.275 sf 1006: * with COMP_DELAYED will turn on compression immediately.
1.118 markus 1007: */
1.201 markus 1008: state->after_authentication = 1;
1.118 markus 1009: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 1010: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 1011: if (state->newkeys[mode] == NULL)
1.145 markus 1012: continue;
1.201 markus 1013: comp = &state->newkeys[mode]->comp;
1.275 sf 1014: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 1015: if ((r = ssh_packet_init_compression(ssh)) != 0)
1016: return r;
1017: if (mode == MODE_OUT) {
1018: if ((r = start_compression_out(ssh, 6)) != 0)
1019: return r;
1020: } else {
1021: if ((r = start_compression_in(ssh)) != 0)
1022: return r;
1023: }
1.118 markus 1024: comp->enabled = 1;
1025: }
1026: }
1.201 markus 1027: return 0;
1.118 markus 1028: }
1029:
1.226 djm 1030: /* Used to mute debug logging for noisy packet types */
1.242 markus 1031: int
1.226 djm 1032: ssh_packet_log_type(u_char type)
1033: {
1034: switch (type) {
1035: case SSH2_MSG_CHANNEL_DATA:
1036: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1037: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1038: return 0;
1039: default:
1040: return 1;
1041: }
1042: }
1043:
1.118 markus 1044: /*
1.25 markus 1045: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1046: */
1.201 markus 1047: int
1048: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1049: {
1.201 markus 1050: struct session_state *state = ssh->state;
1.200 markus 1051: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1052: u_char tmp, padlen, pad = 0;
1.201 markus 1053: u_int authlen = 0, aadlen = 0;
1054: u_int len;
1055: struct sshenc *enc = NULL;
1056: struct sshmac *mac = NULL;
1057: struct sshcomp *comp = NULL;
1058: int r, block_size;
1059:
1060: if (state->newkeys[MODE_OUT] != NULL) {
1061: enc = &state->newkeys[MODE_OUT]->enc;
1062: mac = &state->newkeys[MODE_OUT]->mac;
1063: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1064: /* disable mac for authenticated encryption */
1065: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1066: mac = NULL;
1.25 markus 1067: }
1.88 markus 1068: block_size = enc ? enc->block_size : 8;
1.180 markus 1069: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1070:
1.201 markus 1071: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1072: if (ssh_packet_log_type(type))
1073: debug3("send packet: type %u", type);
1.25 markus 1074: #ifdef PACKET_DEBUG
1075: fprintf(stderr, "plain: ");
1.201 markus 1076: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1077: #endif
1078:
1079: if (comp && comp->enabled) {
1.201 markus 1080: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1081: /* skip header, compress only payload */
1.201 markus 1082: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1083: goto out;
1084: sshbuf_reset(state->compression_buffer);
1085: if ((r = compress_buffer(ssh, state->outgoing_packet,
1086: state->compression_buffer)) != 0)
1087: goto out;
1088: sshbuf_reset(state->outgoing_packet);
1089: if ((r = sshbuf_put(state->outgoing_packet,
1090: "\0\0\0\0\0", 5)) != 0 ||
1091: (r = sshbuf_putb(state->outgoing_packet,
1092: state->compression_buffer)) != 0)
1093: goto out;
1094: DBG(debug("compression: raw %d compressed %zd", len,
1095: sshbuf_len(state->outgoing_packet)));
1.25 markus 1096: }
1097:
1098: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1099: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1100:
1101: /*
1102: * calc size of padding, alloc space, get random data,
1103: * minimum padding is 4 bytes
1104: */
1.178 markus 1105: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1106: padlen = block_size - (len % block_size);
1107: if (padlen < 4)
1108: padlen += block_size;
1.201 markus 1109: if (state->extra_pad) {
1.233 djm 1110: tmp = state->extra_pad;
1.201 markus 1111: state->extra_pad =
1.237 deraadt 1112: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1113: /* check if roundup overflowed */
1114: if (state->extra_pad < tmp)
1115: return SSH_ERR_INVALID_ARGUMENT;
1116: tmp = (len + padlen) % state->extra_pad;
1117: /* Check whether pad calculation below will underflow */
1118: if (tmp > state->extra_pad)
1119: return SSH_ERR_INVALID_ARGUMENT;
1120: pad = state->extra_pad - tmp;
1.193 djm 1121: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1122: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1123: tmp = padlen;
1.71 markus 1124: padlen += pad;
1.233 djm 1125: /* Check whether padlen calculation overflowed */
1126: if (padlen < tmp)
1127: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1128: state->extra_pad = 0;
1.71 markus 1129: }
1.201 markus 1130: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1131: goto out;
1.235 djm 1132: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1133: /* random padding */
1.201 markus 1134: arc4random_buf(cp, padlen);
1.32 markus 1135: } else {
1136: /* clear padding */
1.192 djm 1137: explicit_bzero(cp, padlen);
1.25 markus 1138: }
1.178 markus 1139: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1140: len = sshbuf_len(state->outgoing_packet);
1141: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1142: if (cp == NULL) {
1143: r = SSH_ERR_INTERNAL_ERROR;
1144: goto out;
1145: }
1.25 markus 1146: /* packet_length includes payload, padding and padding length field */
1.201 markus 1147: POKE_U32(cp, len - 4);
1.89 markus 1148: cp[4] = padlen;
1.178 markus 1149: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1150: len, padlen, aadlen));
1.25 markus 1151:
1152: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1153: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1154: if ((r = mac_compute(mac, state->p_send.seqnr,
1155: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1156: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1157: goto out;
1158: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1159: }
1160: /* encrypt packet and append to output buffer. */
1.201 markus 1161: if ((r = sshbuf_reserve(state->output,
1162: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1163: goto out;
1.235 djm 1164: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1165: sshbuf_ptr(state->outgoing_packet),
1166: len - aadlen, aadlen, authlen)) != 0)
1167: goto out;
1.25 markus 1168: /* append unencrypted MAC */
1.178 markus 1169: if (mac && mac->enabled) {
1170: if (mac->etm) {
1171: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1172: if ((r = mac_compute(mac, state->p_send.seqnr,
1173: cp, len, macbuf, sizeof(macbuf))) != 0)
1174: goto out;
1.178 markus 1175: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1176: state->p_send.seqnr));
1.178 markus 1177: }
1.201 markus 1178: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1179: goto out;
1.178 markus 1180: }
1.25 markus 1181: #ifdef PACKET_DEBUG
1182: fprintf(stderr, "encrypted: ");
1.201 markus 1183: sshbuf_dump(state->output, stderr);
1.25 markus 1184: #endif
1.29 markus 1185: /* increment sequence number for outgoing packets */
1.201 markus 1186: if (++state->p_send.seqnr == 0)
1.106 itojun 1187: logit("outgoing seqnr wraps around");
1.201 markus 1188: if (++state->p_send.packets == 0)
1189: if (!(ssh->compat & SSH_BUG_NOREKEY))
1190: return SSH_ERR_NEED_REKEY;
1191: state->p_send.blocks += len / block_size;
1192: state->p_send.bytes += len;
1193: sshbuf_reset(state->outgoing_packet);
1.25 markus 1194:
1.57 markus 1195: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1196: r = ssh_set_newkeys(ssh, MODE_OUT);
1197: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1198: r = ssh_packet_enable_delayed_compress(ssh);
1199: else
1200: r = 0;
1201: out:
1202: return r;
1.25 markus 1203: }
1204:
1.228 djm 1205: /* returns non-zero if the specified packet type is usec by KEX */
1206: static int
1207: ssh_packet_type_is_kex(u_char type)
1208: {
1209: return
1210: type >= SSH2_MSG_TRANSPORT_MIN &&
1211: type <= SSH2_MSG_TRANSPORT_MAX &&
1212: type != SSH2_MSG_SERVICE_REQUEST &&
1213: type != SSH2_MSG_SERVICE_ACCEPT &&
1214: type != SSH2_MSG_EXT_INFO;
1215: }
1216:
1.201 markus 1217: int
1218: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1219: {
1.201 markus 1220: struct session_state *state = ssh->state;
1.105 markus 1221: struct packet *p;
1.201 markus 1222: u_char type;
1.228 djm 1223: int r, need_rekey;
1.105 markus 1224:
1.228 djm 1225: if (sshbuf_len(state->outgoing_packet) < 6)
1226: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1227: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1228: need_rekey = !ssh_packet_type_is_kex(type) &&
1229: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1230:
1.228 djm 1231: /*
1232: * During rekeying we can only send key exchange messages.
1233: * Queue everything else.
1234: */
1235: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1236: if (need_rekey)
1237: debug3("%s: rekex triggered", __func__);
1238: debug("enqueue packet: %u", type);
1239: p = calloc(1, sizeof(*p));
1240: if (p == NULL)
1241: return SSH_ERR_ALLOC_FAIL;
1242: p->type = type;
1243: p->payload = state->outgoing_packet;
1244: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1245: state->outgoing_packet = sshbuf_new();
1246: if (state->outgoing_packet == NULL)
1247: return SSH_ERR_ALLOC_FAIL;
1248: if (need_rekey) {
1249: /*
1250: * This packet triggered a rekey, so send the
1251: * KEXINIT now.
1252: * NB. reenters this function via kex_start_rekex().
1253: */
1254: return kex_start_rekex(ssh);
1.105 markus 1255: }
1.228 djm 1256: return 0;
1.105 markus 1257: }
1258:
1259: /* rekeying starts with sending KEXINIT */
1260: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1261: state->rekeying = 1;
1.105 markus 1262:
1.201 markus 1263: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1264: return r;
1.105 markus 1265:
1266: /* after a NEWKEYS message we can send the complete queue */
1267: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1268: state->rekeying = 0;
1269: state->rekey_time = monotime();
1270: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1271: type = p->type;
1.228 djm 1272: /*
1273: * If this packet triggers a rekex, then skip the
1274: * remaining packets in the queue for now.
1275: * NB. re-enters this function via kex_start_rekex.
1276: */
1277: if (ssh_packet_need_rekeying(ssh,
1278: sshbuf_len(p->payload))) {
1279: debug3("%s: queued packet triggered rekex",
1280: __func__);
1281: return kex_start_rekex(ssh);
1282: }
1.105 markus 1283: debug("dequeue packet: %u", type);
1.201 markus 1284: sshbuf_free(state->outgoing_packet);
1285: state->outgoing_packet = p->payload;
1286: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1287: memset(p, 0, sizeof(*p));
1.186 djm 1288: free(p);
1.201 markus 1289: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1290: return r;
1.105 markus 1291: }
1292: }
1.201 markus 1293: return 0;
1.25 markus 1294: }
1295:
1296: /*
1.16 markus 1297: * Waits until a packet has been received, and returns its type. Note that
1298: * no other data is processed until this returns, so this function should not
1299: * be used during the interactive session.
1300: */
1.1 deraadt 1301:
1.2 provos 1302: int
1.201 markus 1303: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1304: {
1.201 markus 1305: struct session_state *state = ssh->state;
1.222 markus 1306: int len, r, ms_remain;
1.56 millert 1307: fd_set *setp;
1.14 markus 1308: char buf[8192];
1.155 deraadt 1309: struct timeval timeout, start, *timeoutp = NULL;
1310:
1.25 markus 1311: DBG(debug("packet_read()"));
1.14 markus 1312:
1.214 deraadt 1313: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1314: NFDBITS), sizeof(fd_mask));
1.201 markus 1315: if (setp == NULL)
1316: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1317:
1.205 djm 1318: /*
1319: * Since we are blocking, ensure that all written packets have
1320: * been sent.
1321: */
1.210 markus 1322: if ((r = ssh_packet_write_wait(ssh)) != 0)
1323: goto out;
1.14 markus 1324:
1325: /* Stay in the loop until we have received a complete packet. */
1326: for (;;) {
1327: /* Try to read a packet from the buffer. */
1.201 markus 1328: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1329: if (r != 0)
1330: break;
1.14 markus 1331: /* If we got a packet, return it. */
1.201 markus 1332: if (*typep != SSH_MSG_NONE)
1333: break;
1.16 markus 1334: /*
1335: * Otherwise, wait for some data to arrive, add it to the
1336: * buffer, and try again.
1337: */
1.201 markus 1338: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1339: NFDBITS) * sizeof(fd_mask));
1.201 markus 1340: FD_SET(state->connection_in, setp);
1.16 markus 1341:
1.201 markus 1342: if (state->packet_timeout_ms > 0) {
1343: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1344: timeoutp = &timeout;
1345: }
1.14 markus 1346: /* Wait for some data to arrive. */
1.154 dtucker 1347: for (;;) {
1.291 markus 1348: if (state->packet_timeout_ms > 0) {
1.154 dtucker 1349: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1350: monotime_tv(&start);
1.154 dtucker 1351: }
1.201 markus 1352: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1353: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1354: break;
1.270 dtucker 1355: if (errno != EAGAIN && errno != EINTR) {
1356: r = SSH_ERR_SYSTEM_ERROR;
1357: goto out;
1358: }
1.291 markus 1359: if (state->packet_timeout_ms <= 0)
1.154 dtucker 1360: continue;
1361: ms_subtract_diff(&start, &ms_remain);
1362: if (ms_remain <= 0) {
1.201 markus 1363: r = 0;
1.154 dtucker 1364: break;
1365: }
1366: }
1.246 djm 1367: if (r == 0) {
1368: r = SSH_ERR_CONN_TIMEOUT;
1369: goto out;
1370: }
1.14 markus 1371: /* Read data from the socket. */
1.222 markus 1372: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1373: if (len == 0) {
1374: r = SSH_ERR_CONN_CLOSED;
1375: goto out;
1376: }
1.286 deraadt 1377: if (len == -1) {
1.210 markus 1378: r = SSH_ERR_SYSTEM_ERROR;
1379: goto out;
1380: }
1.204 djm 1381:
1.14 markus 1382: /* Append it to the buffer. */
1.204 djm 1383: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1384: goto out;
1.14 markus 1385: }
1.210 markus 1386: out:
1.201 markus 1387: free(setp);
1388: return r;
1.1 deraadt 1389: }
1390:
1.77 djm 1391: int
1.201 markus 1392: ssh_packet_read(struct ssh *ssh)
1.77 djm 1393: {
1.201 markus 1394: u_char type;
1395: int r;
1396:
1397: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1398: fatal("%s: %s", __func__, ssh_err(r));
1399: return type;
1.77 djm 1400: }
1401:
1.16 markus 1402: /*
1403: * Waits until a packet has been received, verifies that its type matches
1404: * that given, and gives a fatal error and exits if there is a mismatch.
1405: */
1.1 deraadt 1406:
1.205 djm 1407: int
1408: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1409: {
1.205 djm 1410: int r;
1411: u_char type;
1.1 deraadt 1412:
1.205 djm 1413: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1414: return r;
1415: if (type != expected_type) {
1416: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1417: "Protocol error: expected packet type %d, got %d",
1.205 djm 1418: expected_type, type)) != 0)
1419: return r;
1420: return SSH_ERR_PROTOCOL_ERROR;
1421: }
1422: return 0;
1.1 deraadt 1423: }
1.14 markus 1424:
1.242 markus 1425: static int
1426: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1427: {
1428: struct session_state *state = ssh->state;
1429: const u_char *cp;
1430: size_t need;
1431: int r;
1432:
1433: if (ssh->kex)
1434: return SSH_ERR_INTERNAL_ERROR;
1435: *typep = SSH_MSG_NONE;
1436: cp = sshbuf_ptr(state->input);
1437: if (state->packlen == 0) {
1438: if (sshbuf_len(state->input) < 4 + 1)
1439: return 0; /* packet is incomplete */
1440: state->packlen = PEEK_U32(cp);
1441: if (state->packlen < 4 + 1 ||
1442: state->packlen > PACKET_MAX_SIZE)
1443: return SSH_ERR_MESSAGE_INCOMPLETE;
1444: }
1445: need = state->packlen + 4;
1446: if (sshbuf_len(state->input) < need)
1447: return 0; /* packet is incomplete */
1448: sshbuf_reset(state->incoming_packet);
1449: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1450: state->packlen)) != 0 ||
1451: (r = sshbuf_consume(state->input, need)) != 0 ||
1452: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1453: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1454: return r;
1455: if (ssh_packet_log_type(*typep))
1456: debug3("%s: type %u", __func__, *typep);
1457: /* sshbuf_dump(state->incoming_packet, stderr); */
1458: /* reset for next packet */
1459: state->packlen = 0;
1460: return r;
1461: }
1462:
1.201 markus 1463: int
1464: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1465: {
1.201 markus 1466: struct session_state *state = ssh->state;
1.40 markus 1467: u_int padlen, need;
1.231 djm 1468: u_char *cp;
1.201 markus 1469: u_int maclen, aadlen = 0, authlen = 0, block_size;
1470: struct sshenc *enc = NULL;
1471: struct sshmac *mac = NULL;
1472: struct sshcomp *comp = NULL;
1.200 markus 1473: int r;
1.201 markus 1474:
1.242 markus 1475: if (state->mux)
1476: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1477:
1.201 markus 1478: *typep = SSH_MSG_NONE;
1479:
1480: if (state->packet_discard)
1481: return 0;
1482:
1483: if (state->newkeys[MODE_IN] != NULL) {
1484: enc = &state->newkeys[MODE_IN]->enc;
1485: mac = &state->newkeys[MODE_IN]->mac;
1486: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1487: /* disable mac for authenticated encryption */
1488: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1489: mac = NULL;
1.25 markus 1490: }
1491: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1492: block_size = enc ? enc->block_size : 8;
1.180 markus 1493: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1494:
1.201 markus 1495: if (aadlen && state->packlen == 0) {
1.235 djm 1496: if (cipher_get_length(state->receive_context,
1.201 markus 1497: &state->packlen, state->p_read.seqnr,
1498: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1499: return 0;
1500: if (state->packlen < 1 + 4 ||
1501: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1502: #ifdef PACKET_DEBUG
1.201 markus 1503: sshbuf_dump(state->input, stderr);
1.178 markus 1504: #endif
1.201 markus 1505: logit("Bad packet length %u.", state->packlen);
1506: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1507: return r;
1.217 djm 1508: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1509: }
1.201 markus 1510: sshbuf_reset(state->incoming_packet);
1511: } else if (state->packlen == 0) {
1.25 markus 1512: /*
1513: * check if input size is less than the cipher block size,
1514: * decrypt first block and extract length of incoming packet
1515: */
1.201 markus 1516: if (sshbuf_len(state->input) < block_size)
1517: return 0;
1518: sshbuf_reset(state->incoming_packet);
1519: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1520: &cp)) != 0)
1521: goto out;
1.235 djm 1522: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1523: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1524: block_size, 0, 0)) != 0)
1525: goto out;
1526: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1527: if (state->packlen < 1 + 4 ||
1528: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1529: #ifdef PACKET_DEBUG
1.201 markus 1530: fprintf(stderr, "input: \n");
1531: sshbuf_dump(state->input, stderr);
1532: fprintf(stderr, "incoming_packet: \n");
1533: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1534: #endif
1.201 markus 1535: logit("Bad packet length %u.", state->packlen);
1.234 markus 1536: return ssh_packet_start_discard(ssh, enc, mac, 0,
1537: PACKET_MAX_SIZE);
1.25 markus 1538: }
1.201 markus 1539: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1540: goto out;
1.25 markus 1541: }
1.201 markus 1542: DBG(debug("input: packet len %u", state->packlen+4));
1543:
1.178 markus 1544: if (aadlen) {
1545: /* only the payload is encrypted */
1.201 markus 1546: need = state->packlen;
1.178 markus 1547: } else {
1548: /*
1549: * the payload size and the payload are encrypted, but we
1550: * have a partial packet of block_size bytes
1551: */
1.201 markus 1552: need = 4 + state->packlen - block_size;
1.178 markus 1553: }
1.180 markus 1554: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1555: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1556: if (need % block_size != 0) {
1557: logit("padding error: need %d block %d mod %d",
1.25 markus 1558: need, block_size, need % block_size);
1.234 markus 1559: return ssh_packet_start_discard(ssh, enc, mac, 0,
1560: PACKET_MAX_SIZE - block_size);
1.158 markus 1561: }
1.25 markus 1562: /*
1563: * check if the entire packet has been received and
1.178 markus 1564: * decrypt into incoming_packet:
1565: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1566: * 'need' bytes are encrypted, followed by either
1567: * 'authlen' bytes of authentication tag or
1.178 markus 1568: * 'maclen' bytes of message authentication code.
1.25 markus 1569: */
1.201 markus 1570: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1571: return 0; /* packet is incomplete */
1.25 markus 1572: #ifdef PACKET_DEBUG
1573: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1574: sshbuf_dump(state->input, stderr);
1.25 markus 1575: #endif
1.231 djm 1576: /* EtM: check mac over encrypted input */
1.201 markus 1577: if (mac && mac->enabled && mac->etm) {
1.231 djm 1578: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1579: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1580: sshbuf_ptr(state->input) + aadlen + need + authlen,
1581: maclen)) != 0) {
1582: if (r == SSH_ERR_MAC_INVALID)
1583: logit("Corrupted MAC on input.");
1.201 markus 1584: goto out;
1.231 djm 1585: }
1.201 markus 1586: }
1587: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1588: &cp)) != 0)
1589: goto out;
1.235 djm 1590: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1591: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1592: goto out;
1593: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1594: goto out;
1.29 markus 1595: if (mac && mac->enabled) {
1.231 djm 1596: /* Not EtM: check MAC over cleartext */
1597: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1598: sshbuf_ptr(state->incoming_packet),
1599: sshbuf_len(state->incoming_packet),
1600: sshbuf_ptr(state->input), maclen)) != 0) {
1601: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1602: goto out;
1.159 markus 1603: logit("Corrupted MAC on input.");
1.247 markus 1604: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1605: return SSH_ERR_INTERNAL_ERROR;
1606: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1607: sshbuf_len(state->incoming_packet),
1.247 markus 1608: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1609: }
1.231 djm 1610: /* Remove MAC from input buffer */
1.201 markus 1611: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1612: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1613: goto out;
1.25 markus 1614: }
1.77 djm 1615: if (seqnr_p != NULL)
1.201 markus 1616: *seqnr_p = state->p_read.seqnr;
1617: if (++state->p_read.seqnr == 0)
1.106 itojun 1618: logit("incoming seqnr wraps around");
1.201 markus 1619: if (++state->p_read.packets == 0)
1620: if (!(ssh->compat & SSH_BUG_NOREKEY))
1621: return SSH_ERR_NEED_REKEY;
1622: state->p_read.blocks += (state->packlen + 4) / block_size;
1623: state->p_read.bytes += state->packlen + 4;
1.25 markus 1624:
1625: /* get padlen */
1.201 markus 1626: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1627: DBG(debug("input: padlen %d", padlen));
1.205 djm 1628: if (padlen < 4) {
1629: if ((r = sshpkt_disconnect(ssh,
1630: "Corrupted padlen %d on input.", padlen)) != 0 ||
1631: (r = ssh_packet_write_wait(ssh)) != 0)
1632: return r;
1633: return SSH_ERR_CONN_CORRUPT;
1634: }
1.25 markus 1635:
1636: /* skip packet size + padlen, discard padding */
1.201 markus 1637: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1638: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1639: goto out;
1.25 markus 1640:
1.201 markus 1641: DBG(debug("input: len before de-compress %zd",
1642: sshbuf_len(state->incoming_packet)));
1.25 markus 1643: if (comp && comp->enabled) {
1.201 markus 1644: sshbuf_reset(state->compression_buffer);
1645: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1646: state->compression_buffer)) != 0)
1647: goto out;
1648: sshbuf_reset(state->incoming_packet);
1649: if ((r = sshbuf_putb(state->incoming_packet,
1650: state->compression_buffer)) != 0)
1651: goto out;
1652: DBG(debug("input: len after de-compress %zd",
1653: sshbuf_len(state->incoming_packet)));
1.25 markus 1654: }
1655: /*
1656: * get packet type, implies consume.
1657: * return length of payload (without type field)
1658: */
1.201 markus 1659: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1660: goto out;
1.226 djm 1661: if (ssh_packet_log_type(*typep))
1662: debug3("receive packet: type %u", *typep);
1.205 djm 1663: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1664: if ((r = sshpkt_disconnect(ssh,
1665: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1666: (r = ssh_packet_write_wait(ssh)) != 0)
1667: return r;
1668: return SSH_ERR_PROTOCOL_ERROR;
1669: }
1.243 djm 1670: if (state->hook_in != NULL &&
1671: (r = state->hook_in(ssh, state->incoming_packet, typep,
1672: state->hook_in_ctx)) != 0)
1673: return r;
1.238 markus 1674: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1675: r = ssh_packet_enable_delayed_compress(ssh);
1676: else
1677: r = 0;
1.25 markus 1678: #ifdef PACKET_DEBUG
1.201 markus 1679: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1680: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1681: #endif
1.62 markus 1682: /* reset for next packet */
1.201 markus 1683: state->packlen = 0;
1.228 djm 1684:
1685: /* do we need to rekey? */
1686: if (ssh_packet_need_rekeying(ssh, 0)) {
1687: debug3("%s: rekex triggered", __func__);
1688: if ((r = kex_start_rekex(ssh)) != 0)
1689: return r;
1690: }
1.201 markus 1691: out:
1692: return r;
1.25 markus 1693: }
1694:
1695: int
1.201 markus 1696: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1697: {
1.201 markus 1698: struct session_state *state = ssh->state;
1.96 deraadt 1699: u_int reason, seqnr;
1.201 markus 1700: int r;
1701: u_char *msg;
1.62 markus 1702:
1.25 markus 1703: for (;;) {
1.201 markus 1704: msg = NULL;
1.249 djm 1705: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1706: if (r != 0)
1707: return r;
1708: if (*typep) {
1709: state->keep_alive_timeouts = 0;
1710: DBG(debug("received packet type %d", *typep));
1711: }
1712: switch (*typep) {
1713: case SSH2_MSG_IGNORE:
1714: debug3("Received SSH2_MSG_IGNORE");
1715: break;
1716: case SSH2_MSG_DEBUG:
1717: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1718: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1719: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1720: free(msg);
1.201 markus 1721: return r;
1.48 stevesk 1722: }
1.249 djm 1723: debug("Remote: %.900s", msg);
1724: free(msg);
1725: break;
1726: case SSH2_MSG_DISCONNECT:
1727: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1728: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1729: return r;
1730: /* Ignore normal client exit notifications */
1731: do_log2(ssh->state->server_side &&
1732: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1733: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1734: "Received disconnect from %s port %d:"
1735: "%u: %.400s", ssh_remote_ipaddr(ssh),
1736: ssh_remote_port(ssh), reason, msg);
1737: free(msg);
1738: return SSH_ERR_DISCONNECTED;
1739: case SSH2_MSG_UNIMPLEMENTED:
1740: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1741: return r;
1742: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1743: seqnr);
1744: break;
1745: default:
1746: return 0;
1.25 markus 1747: }
1748: }
1749: }
1750:
1.16 markus 1751: /*
1752: * Buffers the given amount of input characters. This is intended to be used
1753: * together with packet_read_poll.
1754: */
1.1 deraadt 1755:
1.204 djm 1756: int
1.201 markus 1757: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1758: {
1.201 markus 1759: struct session_state *state = ssh->state;
1760: int r;
1761:
1762: if (state->packet_discard) {
1763: state->keep_alive_timeouts = 0; /* ?? */
1764: if (len >= state->packet_discard) {
1765: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1766: return r;
1.201 markus 1767: }
1768: state->packet_discard -= len;
1.204 djm 1769: return 0;
1.159 markus 1770: }
1.201 markus 1771: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1772: return r;
1773:
1774: return 0;
1.28 markus 1775: }
1776:
1777: int
1.201 markus 1778: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1779: {
1.201 markus 1780: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1781: }
1782:
1.16 markus 1783: /*
1784: * Sends a diagnostic message from the server to the client. This message
1785: * can be sent at any time (but not while constructing another message). The
1786: * message is printed immediately, but only if the client is being executed
1787: * in verbose mode. These messages are primarily intended to ease debugging
1788: * authentication problems. The length of the formatted message must not
1.205 djm 1789: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1790: */
1.2 provos 1791: void
1.201 markus 1792: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1793: {
1.14 markus 1794: char buf[1024];
1795: va_list args;
1.201 markus 1796: int r;
1.39 markus 1797:
1.249 djm 1798: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1799: return;
1.14 markus 1800:
1801: va_start(args, fmt);
1802: vsnprintf(buf, sizeof(buf), fmt, args);
1803: va_end(args);
1.265 djm 1804:
1805: debug3("sending debug message: %s", buf);
1.14 markus 1806:
1.249 djm 1807: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1808: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1809: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1810: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1811: (r = sshpkt_send(ssh)) != 0 ||
1812: (r = ssh_packet_write_wait(ssh)) != 0)
1.205 djm 1813: fatal("%s: %s", __func__, ssh_err(r));
1814: }
1815:
1.268 dtucker 1816: void
1817: sshpkt_fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1.245 djm 1818: {
1819: snprintf(s, l, "%.200s%s%s port %d",
1820: ssh->log_preamble ? ssh->log_preamble : "",
1821: ssh->log_preamble ? " " : "",
1822: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1823: }
1824:
1.205 djm 1825: /*
1826: * Pretty-print connection-terminating errors and exit.
1827: */
1.280 djm 1828: static void
1829: sshpkt_vfatal(struct ssh *ssh, int r, const char *fmt, va_list ap)
1.205 djm 1830: {
1.280 djm 1831: char *tag = NULL, remote_id[512];
1.290 djm 1832: int oerrno = errno;
1.245 djm 1833:
1.268 dtucker 1834: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.245 djm 1835:
1.205 djm 1836: switch (r) {
1837: case SSH_ERR_CONN_CLOSED:
1.257 markus 1838: ssh_packet_clear_keys(ssh);
1.245 djm 1839: logdie("Connection closed by %s", remote_id);
1.205 djm 1840: case SSH_ERR_CONN_TIMEOUT:
1.257 markus 1841: ssh_packet_clear_keys(ssh);
1.245 djm 1842: logdie("Connection %s %s timed out",
1843: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1844: case SSH_ERR_DISCONNECTED:
1.257 markus 1845: ssh_packet_clear_keys(ssh);
1.245 djm 1846: logdie("Disconnected from %s", remote_id);
1.212 djm 1847: case SSH_ERR_SYSTEM_ERROR:
1.257 markus 1848: if (errno == ECONNRESET) {
1849: ssh_packet_clear_keys(ssh);
1.245 djm 1850: logdie("Connection reset by %s", remote_id);
1.257 markus 1851: }
1.213 djm 1852: /* FALLTHROUGH */
1853: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1854: case SSH_ERR_NO_MAC_ALG_MATCH:
1855: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1856: case SSH_ERR_NO_KEX_ALG_MATCH:
1857: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1858: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.257 markus 1859: ssh_packet_clear_keys(ssh);
1.290 djm 1860: errno = oerrno;
1.245 djm 1861: logdie("Unable to negotiate with %s: %s. "
1862: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1863: ssh->kex->failed_choice);
1.212 djm 1864: }
1865: /* FALLTHROUGH */
1.205 djm 1866: default:
1.280 djm 1867: if (vasprintf(&tag, fmt, ap) == -1) {
1868: ssh_packet_clear_keys(ssh);
1869: logdie("%s: could not allocate failure message",
1870: __func__);
1871: }
1.257 markus 1872: ssh_packet_clear_keys(ssh);
1.290 djm 1873: errno = oerrno;
1.245 djm 1874: logdie("%s%sConnection %s %s: %s",
1.205 djm 1875: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 1876: ssh->state->server_side ? "from" : "to",
1.245 djm 1877: remote_id, ssh_err(r));
1.205 djm 1878: }
1.1 deraadt 1879: }
1880:
1.280 djm 1881: void
1882: sshpkt_fatal(struct ssh *ssh, int r, const char *fmt, ...)
1883: {
1884: va_list ap;
1885:
1886: va_start(ap, fmt);
1887: sshpkt_vfatal(ssh, r, fmt, ap);
1888: /* NOTREACHED */
1889: va_end(ap);
1890: logdie("%s: should have exited", __func__);
1891: }
1892:
1.16 markus 1893: /*
1894: * Logs the error plus constructs and sends a disconnect packet, closes the
1895: * connection, and exits. This function never returns. The error message
1896: * should not contain a newline. The length of the formatted message must
1897: * not exceed 1024 bytes.
1898: */
1.2 provos 1899: void
1.201 markus 1900: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1901: {
1.245 djm 1902: char buf[1024], remote_id[512];
1.14 markus 1903: va_list args;
1904: static int disconnecting = 0;
1.201 markus 1905: int r;
1.97 deraadt 1906:
1.14 markus 1907: if (disconnecting) /* Guard against recursive invocations. */
1908: fatal("packet_disconnect called recursively.");
1909: disconnecting = 1;
1910:
1.16 markus 1911: /*
1912: * Format the message. Note that the caller must make sure the
1913: * message is of limited size.
1914: */
1.268 dtucker 1915: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1916: va_start(args, fmt);
1917: vsnprintf(buf, sizeof(buf), fmt, args);
1918: va_end(args);
1919:
1.99 markus 1920: /* Display the error locally */
1.245 djm 1921: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1922:
1.205 djm 1923: /*
1924: * Send the disconnect message to the other side, and wait
1925: * for it to get sent.
1926: */
1927: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1.280 djm 1928: sshpkt_fatal(ssh, r, "%s", __func__);
1.205 djm 1929:
1930: if ((r = ssh_packet_write_wait(ssh)) != 0)
1.280 djm 1931: sshpkt_fatal(ssh, r, "%s", __func__);
1.14 markus 1932:
1933: /* Close the connection. */
1.201 markus 1934: ssh_packet_close(ssh);
1.112 markus 1935: cleanup_exit(255);
1.1 deraadt 1936: }
1937:
1.205 djm 1938: /*
1939: * Checks if there is any buffered output, and tries to write some of
1940: * the output.
1941: */
1942: int
1.201 markus 1943: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1944: {
1.201 markus 1945: struct session_state *state = ssh->state;
1946: int len = sshbuf_len(state->output);
1.222 markus 1947: int r;
1.97 deraadt 1948:
1.14 markus 1949: if (len > 0) {
1.222 markus 1950: len = write(state->connection_out,
1951: sshbuf_ptr(state->output), len);
1.156 djm 1952: if (len == -1) {
1953: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1954: return 0;
1955: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1956: }
1.222 markus 1957: if (len == 0)
1.205 djm 1958: return SSH_ERR_CONN_CLOSED;
1.201 markus 1959: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1960: return r;
1.14 markus 1961: }
1.205 djm 1962: return 0;
1.1 deraadt 1963: }
1964:
1.16 markus 1965: /*
1966: * Calls packet_write_poll repeatedly until all pending output data has been
1967: * written.
1968: */
1.205 djm 1969: int
1.201 markus 1970: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1971: {
1.56 millert 1972: fd_set *setp;
1.205 djm 1973: int ret, r, ms_remain = 0;
1.154 dtucker 1974: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1975: struct session_state *state = ssh->state;
1.56 millert 1976:
1.214 deraadt 1977: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1978: NFDBITS), sizeof(fd_mask));
1.201 markus 1979: if (setp == NULL)
1.205 djm 1980: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1981: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1982: free(setp);
1.215 djm 1983: return r;
1.216 gsoares 1984: }
1.201 markus 1985: while (ssh_packet_have_data_to_write(ssh)) {
1986: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1987: NFDBITS) * sizeof(fd_mask));
1.201 markus 1988: FD_SET(state->connection_out, setp);
1.154 dtucker 1989:
1.201 markus 1990: if (state->packet_timeout_ms > 0) {
1991: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1992: timeoutp = &timeout;
1993: }
1994: for (;;) {
1.291 markus 1995: if (state->packet_timeout_ms > 0) {
1.154 dtucker 1996: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1997: monotime_tv(&start);
1.154 dtucker 1998: }
1.201 markus 1999: if ((ret = select(state->connection_out + 1,
1.161 andreas 2000: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 2001: break;
1.161 andreas 2002: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 2003: break;
1.291 markus 2004: if (state->packet_timeout_ms <= 0)
1.154 dtucker 2005: continue;
2006: ms_subtract_diff(&start, &ms_remain);
2007: if (ms_remain <= 0) {
2008: ret = 0;
2009: break;
2010: }
2011: }
2012: if (ret == 0) {
1.205 djm 2013: free(setp);
2014: return SSH_ERR_CONN_TIMEOUT;
2015: }
2016: if ((r = ssh_packet_write_poll(ssh)) != 0) {
2017: free(setp);
2018: return r;
1.154 dtucker 2019: }
1.14 markus 2020: }
1.186 djm 2021: free(setp);
1.205 djm 2022: return 0;
1.1 deraadt 2023: }
2024:
2025: /* Returns true if there is buffered data to write to the connection. */
2026:
1.2 provos 2027: int
1.201 markus 2028: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 2029: {
1.201 markus 2030: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 2031: }
2032:
2033: /* Returns true if there is not too much data to write to the connection. */
2034:
1.2 provos 2035: int
1.201 markus 2036: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 2037: {
1.201 markus 2038: if (ssh->state->interactive_mode)
2039: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 2040: else
1.201 markus 2041: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 2042: }
2043:
1.201 markus 2044: void
2045: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 2046: {
1.263 djm 2047: if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
1.101 markus 2048: return;
1.201 markus 2049: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 2050: case AF_INET:
2051: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 2052: if (setsockopt(ssh->state->connection_in,
1.286 deraadt 2053: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) == -1)
1.173 djm 2054: error("setsockopt IP_TOS %d: %.100s:",
2055: tos, strerror(errno));
2056: break;
2057: case AF_INET6:
2058: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 2059: if (setsockopt(ssh->state->connection_in,
1.286 deraadt 2060: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) == -1)
1.173 djm 2061: error("setsockopt IPV6_TCLASS %d: %.100s:",
2062: tos, strerror(errno));
2063: break;
2064: }
1.101 markus 2065: }
2066:
1.1 deraadt 2067: /* Informs that the current session is interactive. Sets IP flags for that. */
2068:
1.2 provos 2069: void
1.201 markus 2070: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2071: {
1.201 markus 2072: struct session_state *state = ssh->state;
2073:
2074: if (state->set_interactive_called)
1.43 markus 2075: return;
1.201 markus 2076: state->set_interactive_called = 1;
1.1 deraadt 2077:
1.14 markus 2078: /* Record that we are in interactive mode. */
1.201 markus 2079: state->interactive_mode = interactive;
1.1 deraadt 2080:
1.19 markus 2081: /* Only set socket options if using a socket. */
1.201 markus 2082: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2083: return;
1.201 markus 2084: set_nodelay(state->connection_in);
2085: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2086: qos_bulk);
1.1 deraadt 2087: }
2088:
2089: /* Returns true if the current connection is interactive. */
2090:
1.2 provos 2091: int
1.201 markus 2092: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2093: {
1.201 markus 2094: return ssh->state->interactive_mode;
1.12 markus 2095: }
2096:
1.113 deraadt 2097: int
1.201 markus 2098: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2099: {
1.201 markus 2100: struct session_state *state = ssh->state;
2101:
2102: if (state->set_maxsize_called) {
1.106 itojun 2103: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2104: state->max_packet_size, s);
1.14 markus 2105: return -1;
2106: }
2107: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2108: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2109: return -1;
2110: }
1.201 markus 2111: state->set_maxsize_called = 1;
1.66 markus 2112: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2113: state->max_packet_size = s;
1.14 markus 2114: return s;
1.53 markus 2115: }
2116:
1.161 andreas 2117: int
1.201 markus 2118: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2119: {
1.201 markus 2120: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2121: }
2122:
2123: void
1.201 markus 2124: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2125: {
1.201 markus 2126: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2127: }
2128:
2129: u_int
1.201 markus 2130: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2131: {
1.201 markus 2132: return ssh->state->max_packet_size;
1.71 markus 2133: }
2134:
1.105 markus 2135: void
1.244 dtucker 2136: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2137: {
1.244 dtucker 2138: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2139: (unsigned int)seconds);
1.201 markus 2140: ssh->state->rekey_limit = bytes;
2141: ssh->state->rekey_interval = seconds;
1.184 dtucker 2142: }
2143:
2144: time_t
1.201 markus 2145: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2146: {
2147: time_t seconds;
2148:
1.201 markus 2149: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2150: monotime();
1.185 dtucker 2151: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2152: }
2153:
2154: void
1.201 markus 2155: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2156: {
1.201 markus 2157: ssh->state->server_side = 1;
1.278 djm 2158: ssh->kex->server = 1; /* XXX unify? */
1.118 markus 2159: }
2160:
2161: void
1.201 markus 2162: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2163: {
1.201 markus 2164: ssh->state->after_authentication = 1;
1.161 andreas 2165: }
2166:
2167: void *
1.201 markus 2168: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2169: {
1.201 markus 2170: return (void *)ssh->state->input;
1.161 andreas 2171: }
2172:
2173: void *
1.201 markus 2174: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2175: {
1.201 markus 2176: return (void *)ssh->state->output;
1.166 andreas 2177: }
2178:
1.196 markus 2179: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2180: static int
2181: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2182: {
1.239 djm 2183: int r;
1.196 markus 2184:
2185: debug("%s: called", __func__);
2186: /* This was set in net child, but is not visible in user child */
1.201 markus 2187: ssh->state->after_authentication = 1;
2188: ssh->state->rekeying = 0;
1.239 djm 2189: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2190: return r;
1.201 markus 2191: return 0;
2192: }
2193:
2194: /* Packet state (de-)serialization for privsep */
2195:
2196: /* turn kex into a blob for packet state serialization */
2197: static int
2198: kex_to_blob(struct sshbuf *m, struct kex *kex)
2199: {
2200: int r;
2201:
2202: if ((r = sshbuf_put_string(m, kex->session_id,
2203: kex->session_id_len)) != 0 ||
2204: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
1.269 djm 2205: (r = sshbuf_put_cstring(m, kex->hostkey_alg)) != 0 ||
1.201 markus 2206: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
1.269 djm 2207: (r = sshbuf_put_u32(m, kex->hostkey_nid)) != 0 ||
1.201 markus 2208: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2209: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2210: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
1.278 djm 2211: (r = sshbuf_put_stringb(m, kex->client_version)) != 0 ||
2212: (r = sshbuf_put_stringb(m, kex->server_version)) != 0 ||
2213: (r = sshbuf_put_u32(m, kex->flags)) != 0)
1.201 markus 2214: return r;
2215: return 0;
2216: }
2217:
2218: /* turn key exchange results into a blob for packet state serialization */
2219: static int
2220: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2221: {
2222: struct sshbuf *b;
2223: struct sshcipher_ctx *cc;
2224: struct sshcomp *comp;
2225: struct sshenc *enc;
2226: struct sshmac *mac;
2227: struct newkeys *newkey;
2228: int r;
2229:
2230: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2231: return SSH_ERR_INTERNAL_ERROR;
2232: enc = &newkey->enc;
2233: mac = &newkey->mac;
2234: comp = &newkey->comp;
1.235 djm 2235: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2236: ssh->state->receive_context;
1.201 markus 2237: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2238: return r;
2239: if ((b = sshbuf_new()) == NULL)
2240: return SSH_ERR_ALLOC_FAIL;
2241: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2242: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2243: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2244: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2245: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2246: goto out;
2247: if (cipher_authlen(enc->cipher) == 0) {
2248: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2249: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2250: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2251: goto out;
2252: }
2253: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2254: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2255: goto out;
2256: r = sshbuf_put_stringb(m, b);
2257: out:
1.221 mmcc 2258: sshbuf_free(b);
1.201 markus 2259: return r;
2260: }
2261:
2262: /* serialize packet state into a blob */
2263: int
2264: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2265: {
2266: struct session_state *state = ssh->state;
1.249 djm 2267: int r;
1.201 markus 2268:
1.249 djm 2269: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2270: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2271: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2272: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2273: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2274: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2275: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2276: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2277: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2278: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2279: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2280: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2281: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2282: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2283: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 2284: return r;
1.201 markus 2285:
2286: return 0;
2287: }
2288:
2289: /* restore key exchange results from blob for packet state de-serialization */
2290: static int
2291: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2292: {
2293: struct sshbuf *b = NULL;
2294: struct sshcomp *comp;
2295: struct sshenc *enc;
2296: struct sshmac *mac;
2297: struct newkeys *newkey = NULL;
2298: size_t keylen, ivlen, maclen;
2299: int r;
2300:
2301: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2302: r = SSH_ERR_ALLOC_FAIL;
2303: goto out;
2304: }
2305: if ((r = sshbuf_froms(m, &b)) != 0)
2306: goto out;
2307: #ifdef DEBUG_PK
2308: sshbuf_dump(b, stderr);
2309: #endif
2310: enc = &newkey->enc;
2311: mac = &newkey->mac;
2312: comp = &newkey->comp;
2313:
2314: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2315: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2316: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2317: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2318: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2319: goto out;
1.262 djm 2320: if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2321: r = SSH_ERR_INVALID_FORMAT;
2322: goto out;
2323: }
1.201 markus 2324: if (cipher_authlen(enc->cipher) == 0) {
2325: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2326: goto out;
2327: if ((r = mac_setup(mac, mac->name)) != 0)
2328: goto out;
2329: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2330: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2331: goto out;
2332: if (maclen > mac->key_len) {
2333: r = SSH_ERR_INVALID_FORMAT;
2334: goto out;
2335: }
2336: mac->key_len = maclen;
2337: }
2338: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2339: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2340: goto out;
2341: if (sshbuf_len(b) != 0) {
2342: r = SSH_ERR_INVALID_FORMAT;
2343: goto out;
2344: }
2345: enc->key_len = keylen;
2346: enc->iv_len = ivlen;
2347: ssh->kex->newkeys[mode] = newkey;
2348: newkey = NULL;
2349: r = 0;
2350: out:
1.219 mmcc 2351: free(newkey);
1.221 mmcc 2352: sshbuf_free(b);
1.201 markus 2353: return r;
2354: }
2355:
2356: /* restore kex from blob for packet state de-serialization */
2357: static int
2358: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2359: {
2360: struct kex *kex;
2361: int r;
2362:
1.278 djm 2363: if ((kex = kex_new()) == NULL)
2364: return SSH_ERR_ALLOC_FAIL;
1.201 markus 2365: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2366: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
1.269 djm 2367: (r = sshbuf_get_cstring(m, &kex->hostkey_alg, NULL)) != 0 ||
1.201 markus 2368: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
1.269 djm 2369: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_nid)) != 0 ||
1.201 markus 2370: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2371: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2372: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
1.278 djm 2373: (r = sshbuf_get_stringb(m, kex->client_version)) != 0 ||
2374: (r = sshbuf_get_stringb(m, kex->server_version)) != 0 ||
2375: (r = sshbuf_get_u32(m, &kex->flags)) != 0)
1.201 markus 2376: goto out;
2377: kex->server = 1;
2378: kex->done = 1;
2379: r = 0;
2380: out:
2381: if (r != 0 || kexp == NULL) {
1.278 djm 2382: kex_free(kex);
1.201 markus 2383: if (kexp != NULL)
2384: *kexp = NULL;
2385: } else {
1.278 djm 2386: kex_free(*kexp);
1.201 markus 2387: *kexp = kex;
2388: }
2389: return r;
2390: }
2391:
2392: /*
2393: * Restore packet state from content of blob 'm' (de-serialization).
2394: * Note that 'm' will be partially consumed on parsing or any other errors.
2395: */
2396: int
2397: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2398: {
2399: struct session_state *state = ssh->state;
1.254 djm 2400: const u_char *input, *output;
2401: size_t ilen, olen;
1.201 markus 2402: int r;
2403:
1.249 djm 2404: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2405: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2406: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2407: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2408: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2409: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2410: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2411: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2412: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2413: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2414: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2415: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2416: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2417: return r;
2418: /*
1.296 ! djm 2419: * We set the time here so that in post-auth privsep child we
1.249 djm 2420: * count from the completion of the authentication.
2421: */
2422: state->rekey_time = monotime();
2423: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2424: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2425: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2426: return r;
1.201 markus 2427:
1.239 djm 2428: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2429: return r;
2430:
2431: sshbuf_reset(state->input);
2432: sshbuf_reset(state->output);
2433: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2434: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2435: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2436: (r = sshbuf_put(state->output, output, olen)) != 0)
2437: return r;
2438:
2439: if (sshbuf_len(m))
2440: return SSH_ERR_INVALID_FORMAT;
2441: debug3("%s: done", __func__);
2442: return 0;
2443: }
2444:
2445: /* NEW API */
2446:
2447: /* put data to the outgoing packet */
2448:
2449: int
2450: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2451: {
2452: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2453: }
2454:
2455: int
2456: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2457: {
2458: return sshbuf_putb(ssh->state->outgoing_packet, b);
2459: }
2460:
2461: int
2462: sshpkt_put_u8(struct ssh *ssh, u_char val)
2463: {
2464: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2465: }
2466:
2467: int
2468: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2469: {
2470: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2471: }
2472:
2473: int
2474: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2475: {
2476: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2477: }
2478:
2479: int
2480: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2481: {
2482: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2483: }
2484:
2485: int
2486: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2487: {
2488: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2489: }
2490:
2491: int
2492: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2493: {
2494: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2495: }
2496:
1.211 djm 2497: #ifdef WITH_OPENSSL
1.201 markus 2498: int
2499: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2500: {
2501: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2502: }
2503:
2504:
2505: int
2506: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2507: {
2508: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2509: }
1.211 djm 2510: #endif /* WITH_OPENSSL */
1.201 markus 2511:
2512: /* fetch data from the incoming packet */
2513:
2514: int
2515: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2516: {
2517: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2518: }
2519:
2520: int
2521: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2522: {
2523: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2524: }
2525:
2526: int
2527: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2528: {
2529: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2530: }
2531:
2532: int
2533: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2534: {
2535: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2536: }
2537:
2538: int
2539: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2540: {
2541: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2542: }
2543:
2544: int
2545: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2546: {
2547: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2548: }
2549:
2550: int
1.264 djm 2551: sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2552: {
2553: return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2554: }
2555:
2556: int
1.201 markus 2557: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2558: {
2559: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
1.282 djm 2560: }
2561:
2562: int
2563: sshpkt_getb_froms(struct ssh *ssh, struct sshbuf **valp)
2564: {
2565: return sshbuf_froms(ssh->state->incoming_packet, valp);
1.201 markus 2566: }
2567:
1.211 djm 2568: #ifdef WITH_OPENSSL
1.201 markus 2569: int
2570: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2571: {
2572: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2573: }
2574:
2575: int
1.281 djm 2576: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM **valp)
1.201 markus 2577: {
1.281 djm 2578: return sshbuf_get_bignum2(ssh->state->incoming_packet, valp);
1.201 markus 2579: }
1.211 djm 2580: #endif /* WITH_OPENSSL */
1.201 markus 2581:
2582: int
2583: sshpkt_get_end(struct ssh *ssh)
2584: {
2585: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2586: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2587: return 0;
2588: }
2589:
2590: const u_char *
2591: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2592: {
2593: if (lenp != NULL)
2594: *lenp = sshbuf_len(ssh->state->incoming_packet);
2595: return sshbuf_ptr(ssh->state->incoming_packet);
2596: }
2597:
2598: /* start a new packet */
2599:
2600: int
2601: sshpkt_start(struct ssh *ssh, u_char type)
2602: {
1.249 djm 2603: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2604:
2605: DBG(debug("packet_start[%d]", type));
1.249 djm 2606: memset(buf, 0, sizeof(buf));
2607: buf[sizeof(buf) - 1] = type;
1.201 markus 2608: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2609: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2610: }
2611:
1.242 markus 2612: static int
2613: ssh_packet_send_mux(struct ssh *ssh)
2614: {
2615: struct session_state *state = ssh->state;
2616: u_char type, *cp;
2617: size_t len;
2618: int r;
2619:
2620: if (ssh->kex)
2621: return SSH_ERR_INTERNAL_ERROR;
2622: len = sshbuf_len(state->outgoing_packet);
2623: if (len < 6)
2624: return SSH_ERR_INTERNAL_ERROR;
2625: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2626: type = cp[5];
2627: if (ssh_packet_log_type(type))
2628: debug3("%s: type %u", __func__, type);
2629: /* drop everything, but the connection protocol */
2630: if (type >= SSH2_MSG_CONNECTION_MIN &&
2631: type <= SSH2_MSG_CONNECTION_MAX) {
2632: POKE_U32(cp, len - 4);
2633: if ((r = sshbuf_putb(state->output,
2634: state->outgoing_packet)) != 0)
2635: return r;
2636: /* sshbuf_dump(state->output, stderr); */
2637: }
2638: sshbuf_reset(state->outgoing_packet);
1.264 djm 2639: return 0;
2640: }
2641:
2642: /*
2643: * 9.2. Ignored Data Message
2644: *
2645: * byte SSH_MSG_IGNORE
2646: * string data
2647: *
2648: * All implementations MUST understand (and ignore) this message at any
2649: * time (after receiving the protocol version). No implementation is
2650: * required to send them. This message can be used as an additional
2651: * protection measure against advanced traffic analysis techniques.
2652: */
2653: int
2654: sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2655: {
2656: u_int32_t rnd = 0;
2657: int r;
2658: u_int i;
2659:
2660: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2661: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2662: return r;
2663: for (i = 0; i < nbytes; i++) {
2664: if (i % 4 == 0)
2665: rnd = arc4random();
2666: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2667: return r;
2668: rnd >>= 8;
2669: }
1.242 markus 2670: return 0;
2671: }
2672:
1.201 markus 2673: /* send it */
2674:
2675: int
2676: sshpkt_send(struct ssh *ssh)
2677: {
1.242 markus 2678: if (ssh->state && ssh->state->mux)
2679: return ssh_packet_send_mux(ssh);
1.249 djm 2680: return ssh_packet_send2(ssh);
1.201 markus 2681: }
2682:
2683: int
2684: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2685: {
2686: char buf[1024];
2687: va_list args;
2688: int r;
2689:
2690: va_start(args, fmt);
2691: vsnprintf(buf, sizeof(buf), fmt, args);
2692: va_end(args);
2693:
1.249 djm 2694: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2695: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2696: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2697: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2698: (r = sshpkt_send(ssh)) != 0)
2699: return r;
1.201 markus 2700: return 0;
2701: }
2702:
2703: /* roundup current message to pad bytes */
2704: int
2705: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2706: {
2707: ssh->state->extra_pad = pad;
2708: return 0;
1.1 deraadt 2709: }