Annotation of src/usr.bin/ssh/packet.c, Revision 1.297
1.297 ! djm 1: /* $OpenBSD: packet.c,v 1.296 2020/07/05 23:59:45 djm Exp $ */
1.1 deraadt 2: /*
1.15 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.35 deraadt 6: * This file contains code implementing the packet protocol and communication
7: * with the other side. This same code is used both on client and server side.
1.29 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
1.29 markus 14: *
1.25 markus 15: *
16: * SSH2 packet format added by Markus Friedl.
1.69 markus 17: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.25 markus 18: *
1.35 deraadt 19: * Redistribution and use in source and binary forms, with or without
20: * modification, are permitted provided that the following conditions
21: * are met:
22: * 1. Redistributions of source code must retain the above copyright
23: * notice, this list of conditions and the following disclaimer.
24: * 2. Redistributions in binary form must reproduce the above copyright
25: * notice, this list of conditions and the following disclaimer in the
26: * documentation and/or other materials provided with the distribution.
27: *
28: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15 deraadt 38: */
1.1 deraadt 39:
1.142 deraadt 40: #include <sys/types.h>
1.105 markus 41: #include <sys/queue.h>
1.132 stevesk 42: #include <sys/socket.h>
1.138 stevesk 43: #include <sys/time.h>
1.132 stevesk 44: #include <netinet/in.h>
1.121 stevesk 45: #include <netinet/ip.h>
1.134 stevesk 46:
1.135 stevesk 47: #include <errno.h>
1.230 djm 48: #include <netdb.h>
1.134 stevesk 49: #include <stdarg.h>
1.141 stevesk 50: #include <stdio.h>
1.140 stevesk 51: #include <stdlib.h>
1.137 stevesk 52: #include <string.h>
1.136 stevesk 53: #include <unistd.h>
1.203 deraadt 54: #include <limits.h>
1.278 djm 55: #include <poll.h>
1.142 deraadt 56: #include <signal.h>
1.184 dtucker 57: #include <time.h>
1.1 deraadt 58:
1.288 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) {
1.297 ! djm 280: error_f("cannot load cipher 'none'");
1.205 djm 281: return NULL;
282: }
1.201 markus 283: if (ssh == NULL)
284: ssh = ssh_alloc_session_state();
1.205 djm 285: if (ssh == NULL) {
1.297 ! djm 286: error_f("could not allocate state");
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) {
1.297 ! djm 296: error_fr(r, "cipher_init failed");
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) {
1.297 ! djm 875: debug_f("rekeying %s, input %llu bytes %llu blocks, "
! 876: "output %llu bytes %llu blocks", 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;
1.297 ! djm 898: DBG(debug_f("cipher_init_context: %s", 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;
1.297 ! djm 1121: DBG(debug3_f("adding %d (len %d padlen %d extra_pad %d)",
! 1122: 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)
1.297 ! djm 1237: debug3_f("rekex triggered");
1.228 djm 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))) {
1.297 ! djm 1279: debug3_f("queued packet triggered rekex");
1.228 djm 1280: return kex_start_rekex(ssh);
1281: }
1.105 markus 1282: debug("dequeue packet: %u", type);
1.201 markus 1283: sshbuf_free(state->outgoing_packet);
1284: state->outgoing_packet = p->payload;
1285: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1286: memset(p, 0, sizeof(*p));
1.186 djm 1287: free(p);
1.201 markus 1288: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1289: return r;
1.105 markus 1290: }
1291: }
1.201 markus 1292: return 0;
1.25 markus 1293: }
1294:
1295: /*
1.16 markus 1296: * Waits until a packet has been received, and returns its type. Note that
1297: * no other data is processed until this returns, so this function should not
1298: * be used during the interactive session.
1299: */
1.1 deraadt 1300:
1.2 provos 1301: int
1.201 markus 1302: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1303: {
1.201 markus 1304: struct session_state *state = ssh->state;
1.222 markus 1305: int len, r, ms_remain;
1.56 millert 1306: fd_set *setp;
1.14 markus 1307: char buf[8192];
1.155 deraadt 1308: struct timeval timeout, start, *timeoutp = NULL;
1309:
1.25 markus 1310: DBG(debug("packet_read()"));
1.14 markus 1311:
1.214 deraadt 1312: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1313: NFDBITS), sizeof(fd_mask));
1.201 markus 1314: if (setp == NULL)
1315: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1316:
1.205 djm 1317: /*
1318: * Since we are blocking, ensure that all written packets have
1319: * been sent.
1320: */
1.210 markus 1321: if ((r = ssh_packet_write_wait(ssh)) != 0)
1322: goto out;
1.14 markus 1323:
1324: /* Stay in the loop until we have received a complete packet. */
1325: for (;;) {
1326: /* Try to read a packet from the buffer. */
1.201 markus 1327: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1328: if (r != 0)
1329: break;
1.14 markus 1330: /* If we got a packet, return it. */
1.201 markus 1331: if (*typep != SSH_MSG_NONE)
1332: break;
1.16 markus 1333: /*
1334: * Otherwise, wait for some data to arrive, add it to the
1335: * buffer, and try again.
1336: */
1.201 markus 1337: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1338: NFDBITS) * sizeof(fd_mask));
1.201 markus 1339: FD_SET(state->connection_in, setp);
1.16 markus 1340:
1.201 markus 1341: if (state->packet_timeout_ms > 0) {
1342: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1343: timeoutp = &timeout;
1344: }
1.14 markus 1345: /* Wait for some data to arrive. */
1.154 dtucker 1346: for (;;) {
1.291 markus 1347: if (state->packet_timeout_ms > 0) {
1.154 dtucker 1348: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1349: monotime_tv(&start);
1.154 dtucker 1350: }
1.201 markus 1351: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1352: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1353: break;
1.270 dtucker 1354: if (errno != EAGAIN && errno != EINTR) {
1355: r = SSH_ERR_SYSTEM_ERROR;
1356: goto out;
1357: }
1.291 markus 1358: if (state->packet_timeout_ms <= 0)
1.154 dtucker 1359: continue;
1360: ms_subtract_diff(&start, &ms_remain);
1361: if (ms_remain <= 0) {
1.201 markus 1362: r = 0;
1.154 dtucker 1363: break;
1364: }
1365: }
1.246 djm 1366: if (r == 0) {
1367: r = SSH_ERR_CONN_TIMEOUT;
1368: goto out;
1369: }
1.14 markus 1370: /* Read data from the socket. */
1.222 markus 1371: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1372: if (len == 0) {
1373: r = SSH_ERR_CONN_CLOSED;
1374: goto out;
1375: }
1.286 deraadt 1376: if (len == -1) {
1.210 markus 1377: r = SSH_ERR_SYSTEM_ERROR;
1378: goto out;
1379: }
1.204 djm 1380:
1.14 markus 1381: /* Append it to the buffer. */
1.204 djm 1382: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1383: goto out;
1.14 markus 1384: }
1.210 markus 1385: out:
1.201 markus 1386: free(setp);
1387: return r;
1.1 deraadt 1388: }
1389:
1.77 djm 1390: int
1.201 markus 1391: ssh_packet_read(struct ssh *ssh)
1.77 djm 1392: {
1.201 markus 1393: u_char type;
1394: int r;
1395:
1396: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1.297 ! djm 1397: fatal_fr(r, "read");
1.201 markus 1398: return type;
1.77 djm 1399: }
1400:
1.16 markus 1401: /*
1402: * Waits until a packet has been received, verifies that its type matches
1403: * that given, and gives a fatal error and exits if there is a mismatch.
1404: */
1.1 deraadt 1405:
1.205 djm 1406: int
1407: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1408: {
1.205 djm 1409: int r;
1410: u_char type;
1.1 deraadt 1411:
1.205 djm 1412: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1413: return r;
1414: if (type != expected_type) {
1415: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1416: "Protocol error: expected packet type %d, got %d",
1.205 djm 1417: expected_type, type)) != 0)
1418: return r;
1419: return SSH_ERR_PROTOCOL_ERROR;
1420: }
1421: return 0;
1.1 deraadt 1422: }
1.14 markus 1423:
1.242 markus 1424: static int
1425: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1426: {
1427: struct session_state *state = ssh->state;
1428: const u_char *cp;
1429: size_t need;
1430: int r;
1431:
1432: if (ssh->kex)
1433: return SSH_ERR_INTERNAL_ERROR;
1434: *typep = SSH_MSG_NONE;
1435: cp = sshbuf_ptr(state->input);
1436: if (state->packlen == 0) {
1437: if (sshbuf_len(state->input) < 4 + 1)
1438: return 0; /* packet is incomplete */
1439: state->packlen = PEEK_U32(cp);
1440: if (state->packlen < 4 + 1 ||
1441: state->packlen > PACKET_MAX_SIZE)
1442: return SSH_ERR_MESSAGE_INCOMPLETE;
1443: }
1444: need = state->packlen + 4;
1445: if (sshbuf_len(state->input) < need)
1446: return 0; /* packet is incomplete */
1447: sshbuf_reset(state->incoming_packet);
1448: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1449: state->packlen)) != 0 ||
1450: (r = sshbuf_consume(state->input, need)) != 0 ||
1451: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1452: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1453: return r;
1454: if (ssh_packet_log_type(*typep))
1.297 ! djm 1455: debug3_f("type %u", *typep);
1.242 markus 1456: /* sshbuf_dump(state->incoming_packet, stderr); */
1457: /* reset for next packet */
1458: state->packlen = 0;
1459: return r;
1460: }
1461:
1.201 markus 1462: int
1463: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1464: {
1.201 markus 1465: struct session_state *state = ssh->state;
1.40 markus 1466: u_int padlen, need;
1.231 djm 1467: u_char *cp;
1.201 markus 1468: u_int maclen, aadlen = 0, authlen = 0, block_size;
1469: struct sshenc *enc = NULL;
1470: struct sshmac *mac = NULL;
1471: struct sshcomp *comp = NULL;
1.200 markus 1472: int r;
1.201 markus 1473:
1.242 markus 1474: if (state->mux)
1475: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1476:
1.201 markus 1477: *typep = SSH_MSG_NONE;
1478:
1479: if (state->packet_discard)
1480: return 0;
1481:
1482: if (state->newkeys[MODE_IN] != NULL) {
1483: enc = &state->newkeys[MODE_IN]->enc;
1484: mac = &state->newkeys[MODE_IN]->mac;
1485: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1486: /* disable mac for authenticated encryption */
1487: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1488: mac = NULL;
1.25 markus 1489: }
1490: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1491: block_size = enc ? enc->block_size : 8;
1.180 markus 1492: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1493:
1.201 markus 1494: if (aadlen && state->packlen == 0) {
1.235 djm 1495: if (cipher_get_length(state->receive_context,
1.201 markus 1496: &state->packlen, state->p_read.seqnr,
1497: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1498: return 0;
1499: if (state->packlen < 1 + 4 ||
1500: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1501: #ifdef PACKET_DEBUG
1.201 markus 1502: sshbuf_dump(state->input, stderr);
1.178 markus 1503: #endif
1.201 markus 1504: logit("Bad packet length %u.", state->packlen);
1505: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1506: return r;
1.217 djm 1507: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1508: }
1.201 markus 1509: sshbuf_reset(state->incoming_packet);
1510: } else if (state->packlen == 0) {
1.25 markus 1511: /*
1512: * check if input size is less than the cipher block size,
1513: * decrypt first block and extract length of incoming packet
1514: */
1.201 markus 1515: if (sshbuf_len(state->input) < block_size)
1516: return 0;
1517: sshbuf_reset(state->incoming_packet);
1518: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1519: &cp)) != 0)
1520: goto out;
1.235 djm 1521: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1522: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1523: block_size, 0, 0)) != 0)
1524: goto out;
1525: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1526: if (state->packlen < 1 + 4 ||
1527: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1528: #ifdef PACKET_DEBUG
1.201 markus 1529: fprintf(stderr, "input: \n");
1530: sshbuf_dump(state->input, stderr);
1531: fprintf(stderr, "incoming_packet: \n");
1532: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1533: #endif
1.201 markus 1534: logit("Bad packet length %u.", state->packlen);
1.234 markus 1535: return ssh_packet_start_discard(ssh, enc, mac, 0,
1536: PACKET_MAX_SIZE);
1.25 markus 1537: }
1.201 markus 1538: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1539: goto out;
1.25 markus 1540: }
1.201 markus 1541: DBG(debug("input: packet len %u", state->packlen+4));
1542:
1.178 markus 1543: if (aadlen) {
1544: /* only the payload is encrypted */
1.201 markus 1545: need = state->packlen;
1.178 markus 1546: } else {
1547: /*
1548: * the payload size and the payload are encrypted, but we
1549: * have a partial packet of block_size bytes
1550: */
1.201 markus 1551: need = 4 + state->packlen - block_size;
1.178 markus 1552: }
1.180 markus 1553: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1554: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1555: if (need % block_size != 0) {
1556: logit("padding error: need %d block %d mod %d",
1.25 markus 1557: need, block_size, need % block_size);
1.234 markus 1558: return ssh_packet_start_discard(ssh, enc, mac, 0,
1559: PACKET_MAX_SIZE - block_size);
1.158 markus 1560: }
1.25 markus 1561: /*
1562: * check if the entire packet has been received and
1.178 markus 1563: * decrypt into incoming_packet:
1564: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1565: * 'need' bytes are encrypted, followed by either
1566: * 'authlen' bytes of authentication tag or
1.178 markus 1567: * 'maclen' bytes of message authentication code.
1.25 markus 1568: */
1.201 markus 1569: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1570: return 0; /* packet is incomplete */
1.25 markus 1571: #ifdef PACKET_DEBUG
1572: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1573: sshbuf_dump(state->input, stderr);
1.25 markus 1574: #endif
1.231 djm 1575: /* EtM: check mac over encrypted input */
1.201 markus 1576: if (mac && mac->enabled && mac->etm) {
1.231 djm 1577: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1578: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1579: sshbuf_ptr(state->input) + aadlen + need + authlen,
1580: maclen)) != 0) {
1581: if (r == SSH_ERR_MAC_INVALID)
1582: logit("Corrupted MAC on input.");
1.201 markus 1583: goto out;
1.231 djm 1584: }
1.201 markus 1585: }
1586: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1587: &cp)) != 0)
1588: goto out;
1.235 djm 1589: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1590: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1591: goto out;
1592: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1593: goto out;
1.29 markus 1594: if (mac && mac->enabled) {
1.231 djm 1595: /* Not EtM: check MAC over cleartext */
1596: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1597: sshbuf_ptr(state->incoming_packet),
1598: sshbuf_len(state->incoming_packet),
1599: sshbuf_ptr(state->input), maclen)) != 0) {
1600: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1601: goto out;
1.159 markus 1602: logit("Corrupted MAC on input.");
1.247 markus 1603: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1604: return SSH_ERR_INTERNAL_ERROR;
1605: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1606: sshbuf_len(state->incoming_packet),
1.247 markus 1607: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1608: }
1.231 djm 1609: /* Remove MAC from input buffer */
1.201 markus 1610: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1611: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1612: goto out;
1.25 markus 1613: }
1.77 djm 1614: if (seqnr_p != NULL)
1.201 markus 1615: *seqnr_p = state->p_read.seqnr;
1616: if (++state->p_read.seqnr == 0)
1.106 itojun 1617: logit("incoming seqnr wraps around");
1.201 markus 1618: if (++state->p_read.packets == 0)
1619: if (!(ssh->compat & SSH_BUG_NOREKEY))
1620: return SSH_ERR_NEED_REKEY;
1621: state->p_read.blocks += (state->packlen + 4) / block_size;
1622: state->p_read.bytes += state->packlen + 4;
1.25 markus 1623:
1624: /* get padlen */
1.201 markus 1625: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1626: DBG(debug("input: padlen %d", padlen));
1.205 djm 1627: if (padlen < 4) {
1628: if ((r = sshpkt_disconnect(ssh,
1629: "Corrupted padlen %d on input.", padlen)) != 0 ||
1630: (r = ssh_packet_write_wait(ssh)) != 0)
1631: return r;
1632: return SSH_ERR_CONN_CORRUPT;
1633: }
1.25 markus 1634:
1635: /* skip packet size + padlen, discard padding */
1.201 markus 1636: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1637: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1638: goto out;
1.25 markus 1639:
1.201 markus 1640: DBG(debug("input: len before de-compress %zd",
1641: sshbuf_len(state->incoming_packet)));
1.25 markus 1642: if (comp && comp->enabled) {
1.201 markus 1643: sshbuf_reset(state->compression_buffer);
1644: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1645: state->compression_buffer)) != 0)
1646: goto out;
1647: sshbuf_reset(state->incoming_packet);
1648: if ((r = sshbuf_putb(state->incoming_packet,
1649: state->compression_buffer)) != 0)
1650: goto out;
1651: DBG(debug("input: len after de-compress %zd",
1652: sshbuf_len(state->incoming_packet)));
1.25 markus 1653: }
1654: /*
1655: * get packet type, implies consume.
1656: * return length of payload (without type field)
1657: */
1.201 markus 1658: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1659: goto out;
1.226 djm 1660: if (ssh_packet_log_type(*typep))
1661: debug3("receive packet: type %u", *typep);
1.205 djm 1662: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1663: if ((r = sshpkt_disconnect(ssh,
1664: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1665: (r = ssh_packet_write_wait(ssh)) != 0)
1666: return r;
1667: return SSH_ERR_PROTOCOL_ERROR;
1668: }
1.243 djm 1669: if (state->hook_in != NULL &&
1670: (r = state->hook_in(ssh, state->incoming_packet, typep,
1671: state->hook_in_ctx)) != 0)
1672: return r;
1.238 markus 1673: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1674: r = ssh_packet_enable_delayed_compress(ssh);
1675: else
1676: r = 0;
1.25 markus 1677: #ifdef PACKET_DEBUG
1.201 markus 1678: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1679: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1680: #endif
1.62 markus 1681: /* reset for next packet */
1.201 markus 1682: state->packlen = 0;
1.228 djm 1683:
1684: /* do we need to rekey? */
1685: if (ssh_packet_need_rekeying(ssh, 0)) {
1.297 ! djm 1686: debug3_f("rekex triggered");
1.228 djm 1687: if ((r = kex_start_rekex(ssh)) != 0)
1688: return r;
1689: }
1.201 markus 1690: out:
1691: return r;
1.25 markus 1692: }
1693:
1694: int
1.201 markus 1695: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1696: {
1.201 markus 1697: struct session_state *state = ssh->state;
1.96 deraadt 1698: u_int reason, seqnr;
1.201 markus 1699: int r;
1700: u_char *msg;
1.62 markus 1701:
1.25 markus 1702: for (;;) {
1.201 markus 1703: msg = NULL;
1.249 djm 1704: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1705: if (r != 0)
1706: return r;
1707: if (*typep) {
1708: state->keep_alive_timeouts = 0;
1709: DBG(debug("received packet type %d", *typep));
1710: }
1711: switch (*typep) {
1712: case SSH2_MSG_IGNORE:
1713: debug3("Received SSH2_MSG_IGNORE");
1714: break;
1715: case SSH2_MSG_DEBUG:
1716: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1717: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1718: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1719: free(msg);
1.201 markus 1720: return r;
1.48 stevesk 1721: }
1.249 djm 1722: debug("Remote: %.900s", msg);
1723: free(msg);
1724: break;
1725: case SSH2_MSG_DISCONNECT:
1726: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1727: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1728: return r;
1729: /* Ignore normal client exit notifications */
1730: do_log2(ssh->state->server_side &&
1731: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1732: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1733: "Received disconnect from %s port %d:"
1734: "%u: %.400s", ssh_remote_ipaddr(ssh),
1735: ssh_remote_port(ssh), reason, msg);
1736: free(msg);
1737: return SSH_ERR_DISCONNECTED;
1738: case SSH2_MSG_UNIMPLEMENTED:
1739: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1740: return r;
1741: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1742: seqnr);
1743: break;
1744: default:
1745: return 0;
1.25 markus 1746: }
1747: }
1748: }
1749:
1.16 markus 1750: /*
1751: * Buffers the given amount of input characters. This is intended to be used
1752: * together with packet_read_poll.
1753: */
1.1 deraadt 1754:
1.204 djm 1755: int
1.201 markus 1756: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1757: {
1.201 markus 1758: struct session_state *state = ssh->state;
1759: int r;
1760:
1761: if (state->packet_discard) {
1762: state->keep_alive_timeouts = 0; /* ?? */
1763: if (len >= state->packet_discard) {
1764: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1765: return r;
1.201 markus 1766: }
1767: state->packet_discard -= len;
1.204 djm 1768: return 0;
1.159 markus 1769: }
1.201 markus 1770: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1771: return r;
1772:
1773: return 0;
1.28 markus 1774: }
1775:
1776: int
1.201 markus 1777: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1778: {
1.201 markus 1779: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1780: }
1781:
1.16 markus 1782: /*
1783: * Sends a diagnostic message from the server to the client. This message
1784: * can be sent at any time (but not while constructing another message). The
1785: * message is printed immediately, but only if the client is being executed
1786: * in verbose mode. These messages are primarily intended to ease debugging
1787: * authentication problems. The length of the formatted message must not
1.205 djm 1788: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1789: */
1.2 provos 1790: void
1.201 markus 1791: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1792: {
1.14 markus 1793: char buf[1024];
1794: va_list args;
1.201 markus 1795: int r;
1.39 markus 1796:
1.249 djm 1797: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1798: return;
1.14 markus 1799:
1800: va_start(args, fmt);
1801: vsnprintf(buf, sizeof(buf), fmt, args);
1802: va_end(args);
1.265 djm 1803:
1804: debug3("sending debug message: %s", buf);
1.14 markus 1805:
1.249 djm 1806: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1807: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1808: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1809: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1810: (r = sshpkt_send(ssh)) != 0 ||
1811: (r = ssh_packet_write_wait(ssh)) != 0)
1.297 ! djm 1812: fatal_fr(r, "send DEBUG");
1.205 djm 1813: }
1814:
1.268 dtucker 1815: void
1816: sshpkt_fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1.245 djm 1817: {
1818: snprintf(s, l, "%.200s%s%s port %d",
1819: ssh->log_preamble ? ssh->log_preamble : "",
1820: ssh->log_preamble ? " " : "",
1821: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1822: }
1823:
1.205 djm 1824: /*
1825: * Pretty-print connection-terminating errors and exit.
1826: */
1.280 djm 1827: static void
1828: sshpkt_vfatal(struct ssh *ssh, int r, const char *fmt, va_list ap)
1.205 djm 1829: {
1.280 djm 1830: char *tag = NULL, remote_id[512];
1.290 djm 1831: int oerrno = errno;
1.245 djm 1832:
1.268 dtucker 1833: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.245 djm 1834:
1.205 djm 1835: switch (r) {
1836: case SSH_ERR_CONN_CLOSED:
1.257 markus 1837: ssh_packet_clear_keys(ssh);
1.245 djm 1838: logdie("Connection closed by %s", remote_id);
1.205 djm 1839: case SSH_ERR_CONN_TIMEOUT:
1.257 markus 1840: ssh_packet_clear_keys(ssh);
1.245 djm 1841: logdie("Connection %s %s timed out",
1842: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1843: case SSH_ERR_DISCONNECTED:
1.257 markus 1844: ssh_packet_clear_keys(ssh);
1.245 djm 1845: logdie("Disconnected from %s", remote_id);
1.212 djm 1846: case SSH_ERR_SYSTEM_ERROR:
1.257 markus 1847: if (errno == ECONNRESET) {
1848: ssh_packet_clear_keys(ssh);
1.245 djm 1849: logdie("Connection reset by %s", remote_id);
1.257 markus 1850: }
1.213 djm 1851: /* FALLTHROUGH */
1852: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1853: case SSH_ERR_NO_MAC_ALG_MATCH:
1854: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1855: case SSH_ERR_NO_KEX_ALG_MATCH:
1856: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1857: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.257 markus 1858: ssh_packet_clear_keys(ssh);
1.290 djm 1859: errno = oerrno;
1.245 djm 1860: logdie("Unable to negotiate with %s: %s. "
1861: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1862: ssh->kex->failed_choice);
1.212 djm 1863: }
1864: /* FALLTHROUGH */
1.205 djm 1865: default:
1.280 djm 1866: if (vasprintf(&tag, fmt, ap) == -1) {
1867: ssh_packet_clear_keys(ssh);
1.297 ! djm 1868: logdie_f("could not allocate failure message");
1.280 djm 1869: }
1.257 markus 1870: ssh_packet_clear_keys(ssh);
1.290 djm 1871: errno = oerrno;
1.297 ! djm 1872: logdie_r(r, "%s%sConnection %s %s",
1.205 djm 1873: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.297 ! djm 1874: ssh->state->server_side ? "from" : "to", remote_id);
1.205 djm 1875: }
1.1 deraadt 1876: }
1877:
1.280 djm 1878: void
1879: sshpkt_fatal(struct ssh *ssh, int r, const char *fmt, ...)
1880: {
1881: va_list ap;
1882:
1883: va_start(ap, fmt);
1884: sshpkt_vfatal(ssh, r, fmt, ap);
1885: /* NOTREACHED */
1886: va_end(ap);
1.297 ! djm 1887: logdie_f("should have exited");
1.280 djm 1888: }
1889:
1.16 markus 1890: /*
1891: * Logs the error plus constructs and sends a disconnect packet, closes the
1892: * connection, and exits. This function never returns. The error message
1893: * should not contain a newline. The length of the formatted message must
1894: * not exceed 1024 bytes.
1895: */
1.2 provos 1896: void
1.201 markus 1897: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1898: {
1.245 djm 1899: char buf[1024], remote_id[512];
1.14 markus 1900: va_list args;
1901: static int disconnecting = 0;
1.201 markus 1902: int r;
1.97 deraadt 1903:
1.14 markus 1904: if (disconnecting) /* Guard against recursive invocations. */
1905: fatal("packet_disconnect called recursively.");
1906: disconnecting = 1;
1907:
1.16 markus 1908: /*
1909: * Format the message. Note that the caller must make sure the
1910: * message is of limited size.
1911: */
1.268 dtucker 1912: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1913: va_start(args, fmt);
1914: vsnprintf(buf, sizeof(buf), fmt, args);
1915: va_end(args);
1916:
1.99 markus 1917: /* Display the error locally */
1.245 djm 1918: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1919:
1.205 djm 1920: /*
1921: * Send the disconnect message to the other side, and wait
1922: * for it to get sent.
1923: */
1924: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1.280 djm 1925: sshpkt_fatal(ssh, r, "%s", __func__);
1.205 djm 1926:
1927: if ((r = ssh_packet_write_wait(ssh)) != 0)
1.280 djm 1928: sshpkt_fatal(ssh, r, "%s", __func__);
1.14 markus 1929:
1930: /* Close the connection. */
1.201 markus 1931: ssh_packet_close(ssh);
1.112 markus 1932: cleanup_exit(255);
1.1 deraadt 1933: }
1934:
1.205 djm 1935: /*
1936: * Checks if there is any buffered output, and tries to write some of
1937: * the output.
1938: */
1939: int
1.201 markus 1940: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1941: {
1.201 markus 1942: struct session_state *state = ssh->state;
1943: int len = sshbuf_len(state->output);
1.222 markus 1944: int r;
1.97 deraadt 1945:
1.14 markus 1946: if (len > 0) {
1.222 markus 1947: len = write(state->connection_out,
1948: sshbuf_ptr(state->output), len);
1.156 djm 1949: if (len == -1) {
1950: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1951: return 0;
1952: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1953: }
1.222 markus 1954: if (len == 0)
1.205 djm 1955: return SSH_ERR_CONN_CLOSED;
1.201 markus 1956: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1957: return r;
1.14 markus 1958: }
1.205 djm 1959: return 0;
1.1 deraadt 1960: }
1961:
1.16 markus 1962: /*
1963: * Calls packet_write_poll repeatedly until all pending output data has been
1964: * written.
1965: */
1.205 djm 1966: int
1.201 markus 1967: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1968: {
1.56 millert 1969: fd_set *setp;
1.205 djm 1970: int ret, r, ms_remain = 0;
1.154 dtucker 1971: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1972: struct session_state *state = ssh->state;
1.56 millert 1973:
1.214 deraadt 1974: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1975: NFDBITS), sizeof(fd_mask));
1.201 markus 1976: if (setp == NULL)
1.205 djm 1977: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1978: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1979: free(setp);
1.215 djm 1980: return r;
1.216 gsoares 1981: }
1.201 markus 1982: while (ssh_packet_have_data_to_write(ssh)) {
1983: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1984: NFDBITS) * sizeof(fd_mask));
1.201 markus 1985: FD_SET(state->connection_out, setp);
1.154 dtucker 1986:
1.201 markus 1987: if (state->packet_timeout_ms > 0) {
1988: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1989: timeoutp = &timeout;
1990: }
1991: for (;;) {
1.291 markus 1992: if (state->packet_timeout_ms > 0) {
1.154 dtucker 1993: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1994: monotime_tv(&start);
1.154 dtucker 1995: }
1.201 markus 1996: if ((ret = select(state->connection_out + 1,
1.161 andreas 1997: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1998: break;
1.161 andreas 1999: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 2000: break;
1.291 markus 2001: if (state->packet_timeout_ms <= 0)
1.154 dtucker 2002: continue;
2003: ms_subtract_diff(&start, &ms_remain);
2004: if (ms_remain <= 0) {
2005: ret = 0;
2006: break;
2007: }
2008: }
2009: if (ret == 0) {
1.205 djm 2010: free(setp);
2011: return SSH_ERR_CONN_TIMEOUT;
2012: }
2013: if ((r = ssh_packet_write_poll(ssh)) != 0) {
2014: free(setp);
2015: return r;
1.154 dtucker 2016: }
1.14 markus 2017: }
1.186 djm 2018: free(setp);
1.205 djm 2019: return 0;
1.1 deraadt 2020: }
2021:
2022: /* Returns true if there is buffered data to write to the connection. */
2023:
1.2 provos 2024: int
1.201 markus 2025: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 2026: {
1.201 markus 2027: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 2028: }
2029:
2030: /* Returns true if there is not too much data to write to the connection. */
2031:
1.2 provos 2032: int
1.201 markus 2033: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 2034: {
1.201 markus 2035: if (ssh->state->interactive_mode)
2036: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 2037: else
1.201 markus 2038: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 2039: }
2040:
1.201 markus 2041: void
2042: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 2043: {
1.263 djm 2044: if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
1.101 markus 2045: return;
1.201 markus 2046: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 2047: case AF_INET:
1.297 ! djm 2048: debug3_f("set IP_TOS 0x%02x", tos);
1.201 markus 2049: if (setsockopt(ssh->state->connection_in,
1.286 deraadt 2050: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) == -1)
1.173 djm 2051: error("setsockopt IP_TOS %d: %.100s:",
2052: tos, strerror(errno));
2053: break;
2054: case AF_INET6:
1.297 ! djm 2055: debug3_f("set IPV6_TCLASS 0x%02x", tos);
1.201 markus 2056: if (setsockopt(ssh->state->connection_in,
1.286 deraadt 2057: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) == -1)
1.173 djm 2058: error("setsockopt IPV6_TCLASS %d: %.100s:",
2059: tos, strerror(errno));
2060: break;
2061: }
1.101 markus 2062: }
2063:
1.1 deraadt 2064: /* Informs that the current session is interactive. Sets IP flags for that. */
2065:
1.2 provos 2066: void
1.201 markus 2067: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2068: {
1.201 markus 2069: struct session_state *state = ssh->state;
2070:
2071: if (state->set_interactive_called)
1.43 markus 2072: return;
1.201 markus 2073: state->set_interactive_called = 1;
1.1 deraadt 2074:
1.14 markus 2075: /* Record that we are in interactive mode. */
1.201 markus 2076: state->interactive_mode = interactive;
1.1 deraadt 2077:
1.19 markus 2078: /* Only set socket options if using a socket. */
1.201 markus 2079: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2080: return;
1.201 markus 2081: set_nodelay(state->connection_in);
2082: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2083: qos_bulk);
1.1 deraadt 2084: }
2085:
2086: /* Returns true if the current connection is interactive. */
2087:
1.2 provos 2088: int
1.201 markus 2089: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2090: {
1.201 markus 2091: return ssh->state->interactive_mode;
1.12 markus 2092: }
2093:
1.113 deraadt 2094: int
1.201 markus 2095: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2096: {
1.201 markus 2097: struct session_state *state = ssh->state;
2098:
2099: if (state->set_maxsize_called) {
1.106 itojun 2100: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2101: state->max_packet_size, s);
1.14 markus 2102: return -1;
2103: }
2104: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2105: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2106: return -1;
2107: }
1.201 markus 2108: state->set_maxsize_called = 1;
1.66 markus 2109: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2110: state->max_packet_size = s;
1.14 markus 2111: return s;
1.53 markus 2112: }
2113:
1.161 andreas 2114: int
1.201 markus 2115: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2116: {
1.201 markus 2117: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2118: }
2119:
2120: void
1.201 markus 2121: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2122: {
1.201 markus 2123: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2124: }
2125:
2126: u_int
1.201 markus 2127: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2128: {
1.201 markus 2129: return ssh->state->max_packet_size;
1.71 markus 2130: }
2131:
1.105 markus 2132: void
1.244 dtucker 2133: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2134: {
1.244 dtucker 2135: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2136: (unsigned int)seconds);
1.201 markus 2137: ssh->state->rekey_limit = bytes;
2138: ssh->state->rekey_interval = seconds;
1.184 dtucker 2139: }
2140:
2141: time_t
1.201 markus 2142: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2143: {
2144: time_t seconds;
2145:
1.201 markus 2146: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2147: monotime();
1.185 dtucker 2148: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2149: }
2150:
2151: void
1.201 markus 2152: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2153: {
1.201 markus 2154: ssh->state->server_side = 1;
1.278 djm 2155: ssh->kex->server = 1; /* XXX unify? */
1.118 markus 2156: }
2157:
2158: void
1.201 markus 2159: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2160: {
1.201 markus 2161: ssh->state->after_authentication = 1;
1.161 andreas 2162: }
2163:
2164: void *
1.201 markus 2165: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2166: {
1.201 markus 2167: return (void *)ssh->state->input;
1.161 andreas 2168: }
2169:
2170: void *
1.201 markus 2171: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2172: {
1.201 markus 2173: return (void *)ssh->state->output;
1.166 andreas 2174: }
2175:
1.196 markus 2176: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2177: static int
2178: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2179: {
1.239 djm 2180: int r;
1.196 markus 2181:
1.297 ! djm 2182: debug_f("called");
1.196 markus 2183: /* This was set in net child, but is not visible in user child */
1.201 markus 2184: ssh->state->after_authentication = 1;
2185: ssh->state->rekeying = 0;
1.239 djm 2186: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2187: return r;
1.201 markus 2188: return 0;
2189: }
2190:
2191: /* Packet state (de-)serialization for privsep */
2192:
2193: /* turn kex into a blob for packet state serialization */
2194: static int
2195: kex_to_blob(struct sshbuf *m, struct kex *kex)
2196: {
2197: int r;
2198:
2199: if ((r = sshbuf_put_string(m, kex->session_id,
2200: kex->session_id_len)) != 0 ||
2201: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
1.269 djm 2202: (r = sshbuf_put_cstring(m, kex->hostkey_alg)) != 0 ||
1.201 markus 2203: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
1.269 djm 2204: (r = sshbuf_put_u32(m, kex->hostkey_nid)) != 0 ||
1.201 markus 2205: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2206: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2207: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
1.278 djm 2208: (r = sshbuf_put_stringb(m, kex->client_version)) != 0 ||
2209: (r = sshbuf_put_stringb(m, kex->server_version)) != 0 ||
2210: (r = sshbuf_put_u32(m, kex->flags)) != 0)
1.201 markus 2211: return r;
2212: return 0;
2213: }
2214:
2215: /* turn key exchange results into a blob for packet state serialization */
2216: static int
2217: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2218: {
2219: struct sshbuf *b;
2220: struct sshcipher_ctx *cc;
2221: struct sshcomp *comp;
2222: struct sshenc *enc;
2223: struct sshmac *mac;
2224: struct newkeys *newkey;
2225: int r;
2226:
2227: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2228: return SSH_ERR_INTERNAL_ERROR;
2229: enc = &newkey->enc;
2230: mac = &newkey->mac;
2231: comp = &newkey->comp;
1.235 djm 2232: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2233: ssh->state->receive_context;
1.201 markus 2234: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2235: return r;
2236: if ((b = sshbuf_new()) == NULL)
2237: return SSH_ERR_ALLOC_FAIL;
2238: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2239: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2240: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2241: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2242: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2243: goto out;
2244: if (cipher_authlen(enc->cipher) == 0) {
2245: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2246: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2247: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2248: goto out;
2249: }
2250: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2251: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2252: goto out;
2253: r = sshbuf_put_stringb(m, b);
2254: out:
1.221 mmcc 2255: sshbuf_free(b);
1.201 markus 2256: return r;
2257: }
2258:
2259: /* serialize packet state into a blob */
2260: int
2261: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2262: {
2263: struct session_state *state = ssh->state;
1.249 djm 2264: int r;
1.201 markus 2265:
1.249 djm 2266: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2267: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2268: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2269: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2270: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2271: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2272: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2273: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2274: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2275: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2276: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2277: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2278: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2279: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2280: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 2281: return r;
1.201 markus 2282:
2283: return 0;
2284: }
2285:
2286: /* restore key exchange results from blob for packet state de-serialization */
2287: static int
2288: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2289: {
2290: struct sshbuf *b = NULL;
2291: struct sshcomp *comp;
2292: struct sshenc *enc;
2293: struct sshmac *mac;
2294: struct newkeys *newkey = NULL;
2295: size_t keylen, ivlen, maclen;
2296: int r;
2297:
2298: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2299: r = SSH_ERR_ALLOC_FAIL;
2300: goto out;
2301: }
2302: if ((r = sshbuf_froms(m, &b)) != 0)
2303: goto out;
2304: #ifdef DEBUG_PK
2305: sshbuf_dump(b, stderr);
2306: #endif
2307: enc = &newkey->enc;
2308: mac = &newkey->mac;
2309: comp = &newkey->comp;
2310:
2311: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2312: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2313: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2314: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2315: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2316: goto out;
1.262 djm 2317: if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2318: r = SSH_ERR_INVALID_FORMAT;
2319: goto out;
2320: }
1.201 markus 2321: if (cipher_authlen(enc->cipher) == 0) {
2322: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2323: goto out;
2324: if ((r = mac_setup(mac, mac->name)) != 0)
2325: goto out;
2326: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2327: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2328: goto out;
2329: if (maclen > mac->key_len) {
2330: r = SSH_ERR_INVALID_FORMAT;
2331: goto out;
2332: }
2333: mac->key_len = maclen;
2334: }
2335: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2336: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2337: goto out;
2338: if (sshbuf_len(b) != 0) {
2339: r = SSH_ERR_INVALID_FORMAT;
2340: goto out;
2341: }
2342: enc->key_len = keylen;
2343: enc->iv_len = ivlen;
2344: ssh->kex->newkeys[mode] = newkey;
2345: newkey = NULL;
2346: r = 0;
2347: out:
1.219 mmcc 2348: free(newkey);
1.221 mmcc 2349: sshbuf_free(b);
1.201 markus 2350: return r;
2351: }
2352:
2353: /* restore kex from blob for packet state de-serialization */
2354: static int
2355: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2356: {
2357: struct kex *kex;
2358: int r;
2359:
1.278 djm 2360: if ((kex = kex_new()) == NULL)
2361: return SSH_ERR_ALLOC_FAIL;
1.201 markus 2362: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2363: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
1.269 djm 2364: (r = sshbuf_get_cstring(m, &kex->hostkey_alg, NULL)) != 0 ||
1.201 markus 2365: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
1.269 djm 2366: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_nid)) != 0 ||
1.201 markus 2367: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2368: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2369: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
1.278 djm 2370: (r = sshbuf_get_stringb(m, kex->client_version)) != 0 ||
2371: (r = sshbuf_get_stringb(m, kex->server_version)) != 0 ||
2372: (r = sshbuf_get_u32(m, &kex->flags)) != 0)
1.201 markus 2373: goto out;
2374: kex->server = 1;
2375: kex->done = 1;
2376: r = 0;
2377: out:
2378: if (r != 0 || kexp == NULL) {
1.278 djm 2379: kex_free(kex);
1.201 markus 2380: if (kexp != NULL)
2381: *kexp = NULL;
2382: } else {
1.278 djm 2383: kex_free(*kexp);
1.201 markus 2384: *kexp = kex;
2385: }
2386: return r;
2387: }
2388:
2389: /*
2390: * Restore packet state from content of blob 'm' (de-serialization).
2391: * Note that 'm' will be partially consumed on parsing or any other errors.
2392: */
2393: int
2394: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2395: {
2396: struct session_state *state = ssh->state;
1.254 djm 2397: const u_char *input, *output;
2398: size_t ilen, olen;
1.201 markus 2399: int r;
2400:
1.249 djm 2401: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2402: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2403: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2404: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2405: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2406: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2407: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2408: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2409: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2410: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2411: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2412: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2413: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2414: return r;
2415: /*
1.296 djm 2416: * We set the time here so that in post-auth privsep child we
1.249 djm 2417: * count from the completion of the authentication.
2418: */
2419: state->rekey_time = monotime();
2420: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2421: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2422: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2423: return r;
1.201 markus 2424:
1.239 djm 2425: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2426: return r;
2427:
2428: sshbuf_reset(state->input);
2429: sshbuf_reset(state->output);
2430: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2431: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2432: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2433: (r = sshbuf_put(state->output, output, olen)) != 0)
2434: return r;
2435:
2436: if (sshbuf_len(m))
2437: return SSH_ERR_INVALID_FORMAT;
1.297 ! djm 2438: debug3_f("done");
1.201 markus 2439: return 0;
2440: }
2441:
2442: /* NEW API */
2443:
2444: /* put data to the outgoing packet */
2445:
2446: int
2447: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2448: {
2449: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2450: }
2451:
2452: int
2453: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2454: {
2455: return sshbuf_putb(ssh->state->outgoing_packet, b);
2456: }
2457:
2458: int
2459: sshpkt_put_u8(struct ssh *ssh, u_char val)
2460: {
2461: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2462: }
2463:
2464: int
2465: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2466: {
2467: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2468: }
2469:
2470: int
2471: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2472: {
2473: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2474: }
2475:
2476: int
2477: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2478: {
2479: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2480: }
2481:
2482: int
2483: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2484: {
2485: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2486: }
2487:
2488: int
2489: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2490: {
2491: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2492: }
2493:
1.211 djm 2494: #ifdef WITH_OPENSSL
1.201 markus 2495: int
2496: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2497: {
2498: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2499: }
2500:
2501:
2502: int
2503: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2504: {
2505: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2506: }
1.211 djm 2507: #endif /* WITH_OPENSSL */
1.201 markus 2508:
2509: /* fetch data from the incoming packet */
2510:
2511: int
2512: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2513: {
2514: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2515: }
2516:
2517: int
2518: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2519: {
2520: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2521: }
2522:
2523: int
2524: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2525: {
2526: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2527: }
2528:
2529: int
2530: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2531: {
2532: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2533: }
2534:
2535: int
2536: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2537: {
2538: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2539: }
2540:
2541: int
2542: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2543: {
2544: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2545: }
2546:
2547: int
1.264 djm 2548: sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2549: {
2550: return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2551: }
2552:
2553: int
1.201 markus 2554: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2555: {
2556: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
1.282 djm 2557: }
2558:
2559: int
2560: sshpkt_getb_froms(struct ssh *ssh, struct sshbuf **valp)
2561: {
2562: return sshbuf_froms(ssh->state->incoming_packet, valp);
1.201 markus 2563: }
2564:
1.211 djm 2565: #ifdef WITH_OPENSSL
1.201 markus 2566: int
2567: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2568: {
2569: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2570: }
2571:
2572: int
1.281 djm 2573: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM **valp)
1.201 markus 2574: {
1.281 djm 2575: return sshbuf_get_bignum2(ssh->state->incoming_packet, valp);
1.201 markus 2576: }
1.211 djm 2577: #endif /* WITH_OPENSSL */
1.201 markus 2578:
2579: int
2580: sshpkt_get_end(struct ssh *ssh)
2581: {
2582: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2583: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2584: return 0;
2585: }
2586:
2587: const u_char *
2588: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2589: {
2590: if (lenp != NULL)
2591: *lenp = sshbuf_len(ssh->state->incoming_packet);
2592: return sshbuf_ptr(ssh->state->incoming_packet);
2593: }
2594:
2595: /* start a new packet */
2596:
2597: int
2598: sshpkt_start(struct ssh *ssh, u_char type)
2599: {
1.249 djm 2600: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2601:
2602: DBG(debug("packet_start[%d]", type));
1.249 djm 2603: memset(buf, 0, sizeof(buf));
2604: buf[sizeof(buf) - 1] = type;
1.201 markus 2605: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2606: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2607: }
2608:
1.242 markus 2609: static int
2610: ssh_packet_send_mux(struct ssh *ssh)
2611: {
2612: struct session_state *state = ssh->state;
2613: u_char type, *cp;
2614: size_t len;
2615: int r;
2616:
2617: if (ssh->kex)
2618: return SSH_ERR_INTERNAL_ERROR;
2619: len = sshbuf_len(state->outgoing_packet);
2620: if (len < 6)
2621: return SSH_ERR_INTERNAL_ERROR;
2622: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2623: type = cp[5];
2624: if (ssh_packet_log_type(type))
1.297 ! djm 2625: debug3_f("type %u", type);
1.242 markus 2626: /* drop everything, but the connection protocol */
2627: if (type >= SSH2_MSG_CONNECTION_MIN &&
2628: type <= SSH2_MSG_CONNECTION_MAX) {
2629: POKE_U32(cp, len - 4);
2630: if ((r = sshbuf_putb(state->output,
2631: state->outgoing_packet)) != 0)
2632: return r;
2633: /* sshbuf_dump(state->output, stderr); */
2634: }
2635: sshbuf_reset(state->outgoing_packet);
1.264 djm 2636: return 0;
2637: }
2638:
2639: /*
2640: * 9.2. Ignored Data Message
2641: *
2642: * byte SSH_MSG_IGNORE
2643: * string data
2644: *
2645: * All implementations MUST understand (and ignore) this message at any
2646: * time (after receiving the protocol version). No implementation is
2647: * required to send them. This message can be used as an additional
2648: * protection measure against advanced traffic analysis techniques.
2649: */
2650: int
2651: sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2652: {
2653: u_int32_t rnd = 0;
2654: int r;
2655: u_int i;
2656:
2657: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2658: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2659: return r;
2660: for (i = 0; i < nbytes; i++) {
2661: if (i % 4 == 0)
2662: rnd = arc4random();
2663: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2664: return r;
2665: rnd >>= 8;
2666: }
1.242 markus 2667: return 0;
2668: }
2669:
1.201 markus 2670: /* send it */
2671:
2672: int
2673: sshpkt_send(struct ssh *ssh)
2674: {
1.242 markus 2675: if (ssh->state && ssh->state->mux)
2676: return ssh_packet_send_mux(ssh);
1.249 djm 2677: return ssh_packet_send2(ssh);
1.201 markus 2678: }
2679:
2680: int
2681: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2682: {
2683: char buf[1024];
2684: va_list args;
2685: int r;
2686:
2687: va_start(args, fmt);
2688: vsnprintf(buf, sizeof(buf), fmt, args);
2689: va_end(args);
2690:
1.249 djm 2691: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2692: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2693: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2694: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2695: (r = sshpkt_send(ssh)) != 0)
2696: return r;
1.201 markus 2697: return 0;
2698: }
2699:
2700: /* roundup current message to pad bytes */
2701: int
2702: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2703: {
2704: ssh->state->extra_pad = pad;
2705: return 0;
1.1 deraadt 2706: }
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