Annotation of src/usr.bin/ssh/packet.c, Revision 1.302
1.302 ! deraadt 1: /* $OpenBSD: packet.c,v 1.301 2021/07/16 09:00:23 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: {
1.298 djm 458: return get_sock_af(ssh->state->connection_out);
1.19 markus 459: }
460:
1.1 deraadt 461: /* Sets the connection into non-blocking mode. */
462:
1.2 provos 463: void
1.201 markus 464: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 465: {
1.14 markus 466: /* Set the socket into non-blocking mode. */
1.201 markus 467: set_nonblock(ssh->state->connection_in);
1.14 markus 468:
1.201 markus 469: if (ssh->state->connection_out != ssh->state->connection_in)
470: set_nonblock(ssh->state->connection_out);
1.1 deraadt 471: }
472:
473: /* Returns the socket used for reading. */
474:
1.2 provos 475: int
1.201 markus 476: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 477: {
1.201 markus 478: return ssh->state->connection_in;
1.1 deraadt 479: }
480:
481: /* Returns the descriptor used for writing. */
482:
1.2 provos 483: int
1.201 markus 484: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 485: {
1.201 markus 486: return ssh->state->connection_out;
487: }
488:
489: /*
490: * Returns the IP-address of the remote host as a string. The returned
491: * string must not be freed.
492: */
493:
494: const char *
495: ssh_remote_ipaddr(struct ssh *ssh)
496: {
1.271 djm 497: int sock;
1.220 djm 498:
1.201 markus 499: /* Check whether we have cached the ipaddr. */
1.220 djm 500: if (ssh->remote_ipaddr == NULL) {
501: if (ssh_packet_connection_is_on_socket(ssh)) {
1.271 djm 502: sock = ssh->state->connection_in;
1.220 djm 503: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 djm 504: ssh->remote_port = get_peer_port(sock);
505: ssh->local_ipaddr = get_local_ipaddr(sock);
506: ssh->local_port = get_local_port(sock);
1.220 djm 507: } else {
1.287 tobhe 508: ssh->remote_ipaddr = xstrdup("UNKNOWN");
1.230 djm 509: ssh->remote_port = 65535;
1.287 tobhe 510: ssh->local_ipaddr = xstrdup("UNKNOWN");
1.230 djm 511: ssh->local_port = 65535;
1.220 djm 512: }
513: }
1.201 markus 514: return ssh->remote_ipaddr;
1.1 deraadt 515: }
516:
1.220 djm 517: /* Returns the port number of the remote host. */
518:
519: int
520: ssh_remote_port(struct ssh *ssh)
521: {
522: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
523: return ssh->remote_port;
1.230 djm 524: }
525:
526: /*
527: * Returns the IP-address of the local host as a string. The returned
528: * string must not be freed.
529: */
530:
531: const char *
532: ssh_local_ipaddr(struct ssh *ssh)
533: {
534: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
535: return ssh->local_ipaddr;
536: }
537:
538: /* Returns the port number of the local host. */
539:
540: int
541: ssh_local_port(struct ssh *ssh)
542: {
543: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
544: return ssh->local_port;
1.266 djm 545: }
546:
547: /* Returns the routing domain of the input socket, or NULL if unavailable */
548: const char *
549: ssh_packet_rdomain_in(struct ssh *ssh)
550: {
551: if (ssh->rdomain_in != NULL)
552: return ssh->rdomain_in;
553: if (!ssh_packet_connection_is_on_socket(ssh))
554: return NULL;
555: ssh->rdomain_in = get_rdomain(ssh->state->connection_in);
556: return ssh->rdomain_in;
1.220 djm 557: }
558:
1.1 deraadt 559: /* Closes the connection and clears and frees internal data structures. */
560:
1.257 markus 561: static void
562: ssh_packet_close_internal(struct ssh *ssh, int do_close)
1.1 deraadt 563: {
1.201 markus 564: struct session_state *state = ssh->state;
565: u_int mode;
566:
567: if (!state->initialized)
1.14 markus 568: return;
1.201 markus 569: state->initialized = 0;
1.257 markus 570: if (do_close) {
571: if (state->connection_in == state->connection_out) {
572: close(state->connection_out);
573: } else {
574: close(state->connection_in);
575: close(state->connection_out);
576: }
1.14 markus 577: }
1.201 markus 578: sshbuf_free(state->input);
579: sshbuf_free(state->output);
580: sshbuf_free(state->outgoing_packet);
581: sshbuf_free(state->incoming_packet);
1.257 markus 582: for (mode = 0; mode < MODE_MAX; mode++) {
583: kex_free_newkeys(state->newkeys[mode]); /* current keys */
584: state->newkeys[mode] = NULL;
585: ssh_clear_newkeys(ssh, mode); /* next keys */
586: }
1.288 dtucker 587: #ifdef WITH_ZLIB
1.289 dtucker 588: /* compression state is in shared mem, so we can only release it once */
1.257 markus 589: if (do_close && state->compression_buffer) {
1.201 markus 590: sshbuf_free(state->compression_buffer);
591: if (state->compression_out_started) {
592: z_streamp stream = &state->compression_out_stream;
593: debug("compress outgoing: "
594: "raw data %llu, compressed %llu, factor %.2f",
595: (unsigned long long)stream->total_in,
596: (unsigned long long)stream->total_out,
597: stream->total_in == 0 ? 0.0 :
598: (double) stream->total_out / stream->total_in);
599: if (state->compression_out_failures == 0)
600: deflateEnd(stream);
601: }
602: if (state->compression_in_started) {
1.260 dtucker 603: z_streamp stream = &state->compression_in_stream;
1.201 markus 604: debug("compress incoming: "
605: "raw data %llu, compressed %llu, factor %.2f",
606: (unsigned long long)stream->total_out,
607: (unsigned long long)stream->total_in,
608: stream->total_out == 0 ? 0.0 :
609: (double) stream->total_in / stream->total_out);
610: if (state->compression_in_failures == 0)
611: inflateEnd(stream);
612: }
1.14 markus 613: }
1.288 dtucker 614: #endif /* WITH_ZLIB */
1.235 djm 615: cipher_free(state->send_context);
616: cipher_free(state->receive_context);
617: state->send_context = state->receive_context = NULL;
1.257 markus 618: if (do_close) {
1.277 djm 619: free(ssh->local_ipaddr);
620: ssh->local_ipaddr = NULL;
1.257 markus 621: free(ssh->remote_ipaddr);
622: ssh->remote_ipaddr = NULL;
623: free(ssh->state);
624: ssh->state = NULL;
1.295 markus 625: kex_free(ssh->kex);
626: ssh->kex = NULL;
1.257 markus 627: }
628: }
629:
630: void
631: ssh_packet_close(struct ssh *ssh)
632: {
633: ssh_packet_close_internal(ssh, 1);
634: }
635:
636: void
637: ssh_packet_clear_keys(struct ssh *ssh)
638: {
639: ssh_packet_close_internal(ssh, 0);
1.1 deraadt 640: }
641:
642: /* Sets remote side protocol flags. */
643:
1.2 provos 644: void
1.201 markus 645: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 646: {
1.201 markus 647: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 648: }
649:
650: /* Returns the remote protocol flags set earlier by the above function. */
651:
1.40 markus 652: u_int
1.201 markus 653: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 654: {
1.201 markus 655: return ssh->state->remote_protocol_flags;
1.1 deraadt 656: }
657:
1.16 markus 658: /*
659: * Starts packet compression from the next packet on in both directions.
660: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
661: */
1.1 deraadt 662:
1.201 markus 663: static int
664: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 665: {
1.201 markus 666: if (!ssh->state->compression_buffer &&
1.300 djm 667: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
1.201 markus 668: return SSH_ERR_ALLOC_FAIL;
669: return 0;
1.60 markus 670: }
671:
1.288 dtucker 672: #ifdef WITH_ZLIB
1.201 markus 673: static int
674: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 675: {
1.201 markus 676: if (level < 1 || level > 9)
677: return SSH_ERR_INVALID_ARGUMENT;
678: debug("Enabling compression at level %d.", level);
679: if (ssh->state->compression_out_started == 1)
680: deflateEnd(&ssh->state->compression_out_stream);
681: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
682: case Z_OK:
683: ssh->state->compression_out_started = 1;
684: break;
685: case Z_MEM_ERROR:
686: return SSH_ERR_ALLOC_FAIL;
687: default:
688: return SSH_ERR_INTERNAL_ERROR;
689: }
690: return 0;
1.1 deraadt 691: }
692:
1.201 markus 693: static int
694: start_compression_in(struct ssh *ssh)
695: {
696: if (ssh->state->compression_in_started == 1)
697: inflateEnd(&ssh->state->compression_in_stream);
698: switch (inflateInit(&ssh->state->compression_in_stream)) {
699: case Z_OK:
700: ssh->state->compression_in_started = 1;
701: break;
702: case Z_MEM_ERROR:
703: return SSH_ERR_ALLOC_FAIL;
704: default:
705: return SSH_ERR_INTERNAL_ERROR;
706: }
707: return 0;
1.95 markus 708: }
709:
1.201 markus 710: /* XXX remove need for separate compression buffer */
711: static int
712: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 713: {
1.201 markus 714: u_char buf[4096];
715: int r, status;
716:
717: if (ssh->state->compression_out_started != 1)
718: return SSH_ERR_INTERNAL_ERROR;
719:
720: /* This case is not handled below. */
721: if (sshbuf_len(in) == 0)
722: return 0;
723:
724: /* Input is the contents of the input buffer. */
725: if ((ssh->state->compression_out_stream.next_in =
726: sshbuf_mutable_ptr(in)) == NULL)
727: return SSH_ERR_INTERNAL_ERROR;
728: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
729:
730: /* Loop compressing until deflate() returns with avail_out != 0. */
731: do {
732: /* Set up fixed-size output buffer. */
733: ssh->state->compression_out_stream.next_out = buf;
734: ssh->state->compression_out_stream.avail_out = sizeof(buf);
735:
736: /* Compress as much data into the buffer as possible. */
737: status = deflate(&ssh->state->compression_out_stream,
738: Z_PARTIAL_FLUSH);
739: switch (status) {
740: case Z_MEM_ERROR:
741: return SSH_ERR_ALLOC_FAIL;
742: case Z_OK:
743: /* Append compressed data to output_buffer. */
744: if ((r = sshbuf_put(out, buf, sizeof(buf) -
745: ssh->state->compression_out_stream.avail_out)) != 0)
746: return r;
747: break;
748: case Z_STREAM_ERROR:
749: default:
750: ssh->state->compression_out_failures++;
751: return SSH_ERR_INVALID_FORMAT;
752: }
753: } while (ssh->state->compression_out_stream.avail_out == 0);
754: return 0;
1.1 deraadt 755: }
756:
1.201 markus 757: static int
758: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 759: {
1.201 markus 760: u_char buf[4096];
761: int r, status;
1.1 deraadt 762:
1.201 markus 763: if (ssh->state->compression_in_started != 1)
764: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 765:
1.201 markus 766: if ((ssh->state->compression_in_stream.next_in =
767: sshbuf_mutable_ptr(in)) == NULL)
768: return SSH_ERR_INTERNAL_ERROR;
769: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 770:
1.201 markus 771: for (;;) {
772: /* Set up fixed-size output buffer. */
773: ssh->state->compression_in_stream.next_out = buf;
774: ssh->state->compression_in_stream.avail_out = sizeof(buf);
775:
776: status = inflate(&ssh->state->compression_in_stream,
777: Z_PARTIAL_FLUSH);
778: switch (status) {
779: case Z_OK:
780: if ((r = sshbuf_put(out, buf, sizeof(buf) -
781: ssh->state->compression_in_stream.avail_out)) != 0)
782: return r;
783: break;
784: case Z_BUF_ERROR:
785: /*
786: * Comments in zlib.h say that we should keep calling
787: * inflate() until we get an error. This appears to
788: * be the error that we get.
789: */
790: return 0;
791: case Z_DATA_ERROR:
792: return SSH_ERR_INVALID_FORMAT;
793: case Z_MEM_ERROR:
794: return SSH_ERR_ALLOC_FAIL;
795: case Z_STREAM_ERROR:
796: default:
797: ssh->state->compression_in_failures++;
798: return SSH_ERR_INTERNAL_ERROR;
799: }
800: }
801: /* NOTREACHED */
1.170 djm 802: }
1.288 dtucker 803:
804: #else /* WITH_ZLIB */
805:
806: static int
807: start_compression_out(struct ssh *ssh, int level)
808: {
809: return SSH_ERR_INTERNAL_ERROR;
810: }
811:
812: static int
813: start_compression_in(struct ssh *ssh)
814: {
815: return SSH_ERR_INTERNAL_ERROR;
816: }
817:
818: static int
819: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
820: {
821: return SSH_ERR_INTERNAL_ERROR;
822: }
823:
824: static int
825: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
826: {
827: return SSH_ERR_INTERNAL_ERROR;
828: }
829: #endif /* WITH_ZLIB */
1.170 djm 830:
1.257 markus 831: void
832: ssh_clear_newkeys(struct ssh *ssh, int mode)
833: {
1.259 djm 834: if (ssh->kex && ssh->kex->newkeys[mode]) {
1.257 markus 835: kex_free_newkeys(ssh->kex->newkeys[mode]);
836: ssh->kex->newkeys[mode] = NULL;
837: }
838: }
839:
1.201 markus 840: int
841: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 842: {
1.201 markus 843: struct session_state *state = ssh->state;
844: struct sshenc *enc;
845: struct sshmac *mac;
846: struct sshcomp *comp;
1.235 djm 847: struct sshcipher_ctx **ccp;
1.236 markus 848: struct packet_state *ps;
1.105 markus 849: u_int64_t *max_blocks;
1.259 djm 850: const char *wmsg;
1.197 djm 851: int r, crypt_type;
1.283 djm 852: const char *dir = mode == MODE_OUT ? "out" : "in";
1.57 markus 853:
1.100 markus 854: debug2("set_newkeys: mode %d", mode);
1.57 markus 855:
1.88 markus 856: if (mode == MODE_OUT) {
1.235 djm 857: ccp = &state->send_context;
1.115 avsm 858: crypt_type = CIPHER_ENCRYPT;
1.236 markus 859: ps = &state->p_send;
1.201 markus 860: max_blocks = &state->max_blocks_out;
1.88 markus 861: } else {
1.235 djm 862: ccp = &state->receive_context;
1.115 avsm 863: crypt_type = CIPHER_DECRYPT;
1.236 markus 864: ps = &state->p_read;
1.201 markus 865: max_blocks = &state->max_blocks_in;
1.88 markus 866: }
1.201 markus 867: if (state->newkeys[mode] != NULL) {
1.297 djm 868: debug_f("rekeying %s, input %llu bytes %llu blocks, "
1.300 djm 869: "output %llu bytes %llu blocks", dir,
870: (unsigned long long)state->p_read.bytes,
871: (unsigned long long)state->p_read.blocks,
872: (unsigned long long)state->p_send.bytes,
873: (unsigned long long)state->p_send.blocks);
1.257 markus 874: kex_free_newkeys(state->newkeys[mode]);
875: state->newkeys[mode] = NULL;
1.57 markus 876: }
1.236 markus 877: /* note that both bytes and the seqnr are not reset */
878: ps->packets = ps->blocks = 0;
1.201 markus 879: /* move newkeys from kex to state */
880: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
881: return SSH_ERR_INTERNAL_ERROR;
882: ssh->kex->newkeys[mode] = NULL;
883: enc = &state->newkeys[mode]->enc;
884: mac = &state->newkeys[mode]->mac;
885: comp = &state->newkeys[mode]->comp;
886: if (cipher_authlen(enc->cipher) == 0) {
887: if ((r = mac_init(mac)) != 0)
888: return r;
889: }
890: mac->enabled = 1;
1.297 djm 891: DBG(debug_f("cipher_init_context: %s", dir));
1.279 djm 892: cipher_free(*ccp);
893: *ccp = NULL;
1.235 djm 894: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 895: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 896: return r;
897: if (!state->cipher_warning_done &&
1.235 djm 898: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 899: error("Warning: %s", wmsg);
900: state->cipher_warning_done = 1;
901: }
1.91 markus 902: /* Deleting the keys does not gain extra security */
1.192 djm 903: /* explicit_bzero(enc->iv, enc->block_size);
904: explicit_bzero(enc->key, enc->key_len);
905: explicit_bzero(mac->key, mac->key_len); */
1.275 sf 906: if ((comp->type == COMP_ZLIB ||
907: (comp->type == COMP_DELAYED &&
1.300 djm 908: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 909: if ((r = ssh_packet_init_compression(ssh)) < 0)
910: return r;
911: if (mode == MODE_OUT) {
912: if ((r = start_compression_out(ssh, 6)) != 0)
913: return r;
914: } else {
915: if ((r = start_compression_in(ssh)) != 0)
916: return r;
917: }
1.57 markus 918: comp->enabled = 1;
919: }
1.109 markus 920: /*
921: * The 2^(blocksize*2) limit is too expensive for 3DES,
1.254 djm 922: * so enforce a 1GB limit for small blocksizes.
1.261 dtucker 923: * See RFC4344 section 3.2.
1.109 markus 924: */
925: if (enc->block_size >= 16)
926: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
927: else
928: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 929: if (state->rekey_limit)
1.237 deraadt 930: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 931: state->rekey_limit / enc->block_size);
1.283 djm 932: debug("rekey %s after %llu blocks", dir,
933: (unsigned long long)*max_blocks);
1.201 markus 934: return 0;
1.57 markus 935: }
936:
1.228 djm 937: #define MAX_PACKETS (1U<<31)
938: static int
939: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
940: {
941: struct session_state *state = ssh->state;
942: u_int32_t out_blocks;
943:
944: /* XXX client can't cope with rekeying pre-auth */
945: if (!state->after_authentication)
946: return 0;
947:
948: /* Haven't keyed yet or KEX in progress. */
1.278 djm 949: if (ssh_packet_is_rekeying(ssh))
1.228 djm 950: return 0;
951:
952: /* Peer can't rekey */
953: if (ssh->compat & SSH_BUG_NOREKEY)
954: return 0;
955:
956: /*
957: * Permit one packet in or out per rekey - this allows us to
958: * make progress when rekey limits are very small.
959: */
960: if (state->p_send.packets == 0 && state->p_read.packets == 0)
961: return 0;
962:
963: /* Time-based rekeying */
964: if (state->rekey_interval != 0 &&
1.244 dtucker 965: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 966: return 1;
967:
1.261 dtucker 968: /*
969: * Always rekey when MAX_PACKETS sent in either direction
970: * As per RFC4344 section 3.1 we do this after 2^31 packets.
971: */
1.228 djm 972: if (state->p_send.packets > MAX_PACKETS ||
973: state->p_read.packets > MAX_PACKETS)
974: return 1;
975:
976: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 977: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 978: state->newkeys[MODE_OUT]->enc.block_size);
979: return (state->max_blocks_out &&
980: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
981: (state->max_blocks_in &&
982: (state->p_read.blocks > state->max_blocks_in));
983: }
984:
1.301 djm 985: int
986: ssh_packet_check_rekey(struct ssh *ssh)
987: {
988: if (!ssh_packet_need_rekeying(ssh, 0))
989: return 0;
990: debug3_f("rekex triggered");
991: return kex_start_rekex(ssh);
992: }
993:
1.16 markus 994: /*
1.118 markus 995: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 996: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 997: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
998: */
1.201 markus 999: static int
1000: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 1001: {
1.201 markus 1002: struct session_state *state = ssh->state;
1003: struct sshcomp *comp = NULL;
1004: int r, mode;
1.118 markus 1005:
1006: /*
1007: * Remember that we are past the authentication step, so rekeying
1.275 sf 1008: * with COMP_DELAYED will turn on compression immediately.
1.118 markus 1009: */
1.201 markus 1010: state->after_authentication = 1;
1.118 markus 1011: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 1012: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 1013: if (state->newkeys[mode] == NULL)
1.145 markus 1014: continue;
1.201 markus 1015: comp = &state->newkeys[mode]->comp;
1.275 sf 1016: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 1017: if ((r = ssh_packet_init_compression(ssh)) != 0)
1018: return r;
1019: if (mode == MODE_OUT) {
1020: if ((r = start_compression_out(ssh, 6)) != 0)
1021: return r;
1022: } else {
1023: if ((r = start_compression_in(ssh)) != 0)
1024: return r;
1025: }
1.118 markus 1026: comp->enabled = 1;
1027: }
1028: }
1.201 markus 1029: return 0;
1.118 markus 1030: }
1031:
1.226 djm 1032: /* Used to mute debug logging for noisy packet types */
1.242 markus 1033: int
1.226 djm 1034: ssh_packet_log_type(u_char type)
1035: {
1036: switch (type) {
1037: case SSH2_MSG_CHANNEL_DATA:
1038: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1039: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1040: return 0;
1041: default:
1042: return 1;
1043: }
1044: }
1045:
1.118 markus 1046: /*
1.25 markus 1047: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1048: */
1.201 markus 1049: int
1050: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1051: {
1.201 markus 1052: struct session_state *state = ssh->state;
1.200 markus 1053: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1054: u_char tmp, padlen, pad = 0;
1.201 markus 1055: u_int authlen = 0, aadlen = 0;
1056: u_int len;
1057: struct sshenc *enc = NULL;
1058: struct sshmac *mac = NULL;
1059: struct sshcomp *comp = NULL;
1060: int r, block_size;
1061:
1062: if (state->newkeys[MODE_OUT] != NULL) {
1063: enc = &state->newkeys[MODE_OUT]->enc;
1064: mac = &state->newkeys[MODE_OUT]->mac;
1065: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1066: /* disable mac for authenticated encryption */
1067: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1068: mac = NULL;
1.25 markus 1069: }
1.88 markus 1070: block_size = enc ? enc->block_size : 8;
1.180 markus 1071: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1072:
1.201 markus 1073: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1074: if (ssh_packet_log_type(type))
1075: debug3("send packet: type %u", type);
1.25 markus 1076: #ifdef PACKET_DEBUG
1077: fprintf(stderr, "plain: ");
1.201 markus 1078: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1079: #endif
1080:
1081: if (comp && comp->enabled) {
1.201 markus 1082: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1083: /* skip header, compress only payload */
1.201 markus 1084: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1085: goto out;
1086: sshbuf_reset(state->compression_buffer);
1087: if ((r = compress_buffer(ssh, state->outgoing_packet,
1088: state->compression_buffer)) != 0)
1089: goto out;
1090: sshbuf_reset(state->outgoing_packet);
1091: if ((r = sshbuf_put(state->outgoing_packet,
1092: "\0\0\0\0\0", 5)) != 0 ||
1093: (r = sshbuf_putb(state->outgoing_packet,
1094: state->compression_buffer)) != 0)
1095: goto out;
1096: DBG(debug("compression: raw %d compressed %zd", len,
1097: sshbuf_len(state->outgoing_packet)));
1.25 markus 1098: }
1099:
1100: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1101: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1102:
1103: /*
1104: * calc size of padding, alloc space, get random data,
1105: * minimum padding is 4 bytes
1106: */
1.178 markus 1107: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1108: padlen = block_size - (len % block_size);
1109: if (padlen < 4)
1110: padlen += block_size;
1.201 markus 1111: if (state->extra_pad) {
1.233 djm 1112: tmp = state->extra_pad;
1.201 markus 1113: state->extra_pad =
1.237 deraadt 1114: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1115: /* check if roundup overflowed */
1116: if (state->extra_pad < tmp)
1117: return SSH_ERR_INVALID_ARGUMENT;
1118: tmp = (len + padlen) % state->extra_pad;
1119: /* Check whether pad calculation below will underflow */
1120: if (tmp > state->extra_pad)
1121: return SSH_ERR_INVALID_ARGUMENT;
1122: pad = state->extra_pad - tmp;
1.297 djm 1123: DBG(debug3_f("adding %d (len %d padlen %d extra_pad %d)",
1124: pad, len, padlen, state->extra_pad));
1.233 djm 1125: tmp = padlen;
1.71 markus 1126: padlen += pad;
1.233 djm 1127: /* Check whether padlen calculation overflowed */
1128: if (padlen < tmp)
1129: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1130: state->extra_pad = 0;
1.71 markus 1131: }
1.201 markus 1132: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1133: goto out;
1.235 djm 1134: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1135: /* random padding */
1.201 markus 1136: arc4random_buf(cp, padlen);
1.32 markus 1137: } else {
1138: /* clear padding */
1.192 djm 1139: explicit_bzero(cp, padlen);
1.25 markus 1140: }
1.178 markus 1141: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1142: len = sshbuf_len(state->outgoing_packet);
1143: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1144: if (cp == NULL) {
1145: r = SSH_ERR_INTERNAL_ERROR;
1146: goto out;
1147: }
1.25 markus 1148: /* packet_length includes payload, padding and padding length field */
1.201 markus 1149: POKE_U32(cp, len - 4);
1.89 markus 1150: cp[4] = padlen;
1.178 markus 1151: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1152: len, padlen, aadlen));
1.25 markus 1153:
1154: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1155: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1156: if ((r = mac_compute(mac, state->p_send.seqnr,
1157: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1158: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1159: goto out;
1160: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1161: }
1162: /* encrypt packet and append to output buffer. */
1.201 markus 1163: if ((r = sshbuf_reserve(state->output,
1164: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1165: goto out;
1.235 djm 1166: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1167: sshbuf_ptr(state->outgoing_packet),
1168: len - aadlen, aadlen, authlen)) != 0)
1169: goto out;
1.25 markus 1170: /* append unencrypted MAC */
1.178 markus 1171: if (mac && mac->enabled) {
1172: if (mac->etm) {
1173: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1174: if ((r = mac_compute(mac, state->p_send.seqnr,
1175: cp, len, macbuf, sizeof(macbuf))) != 0)
1176: goto out;
1.178 markus 1177: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1178: state->p_send.seqnr));
1.178 markus 1179: }
1.201 markus 1180: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1181: goto out;
1.178 markus 1182: }
1.25 markus 1183: #ifdef PACKET_DEBUG
1184: fprintf(stderr, "encrypted: ");
1.201 markus 1185: sshbuf_dump(state->output, stderr);
1.25 markus 1186: #endif
1.29 markus 1187: /* increment sequence number for outgoing packets */
1.201 markus 1188: if (++state->p_send.seqnr == 0)
1.106 itojun 1189: logit("outgoing seqnr wraps around");
1.201 markus 1190: if (++state->p_send.packets == 0)
1191: if (!(ssh->compat & SSH_BUG_NOREKEY))
1192: return SSH_ERR_NEED_REKEY;
1193: state->p_send.blocks += len / block_size;
1194: state->p_send.bytes += len;
1195: sshbuf_reset(state->outgoing_packet);
1.25 markus 1196:
1.57 markus 1197: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1198: r = ssh_set_newkeys(ssh, MODE_OUT);
1199: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1200: r = ssh_packet_enable_delayed_compress(ssh);
1201: else
1202: r = 0;
1203: out:
1204: return r;
1.25 markus 1205: }
1206:
1.228 djm 1207: /* returns non-zero if the specified packet type is usec by KEX */
1208: static int
1209: ssh_packet_type_is_kex(u_char type)
1210: {
1211: return
1212: type >= SSH2_MSG_TRANSPORT_MIN &&
1213: type <= SSH2_MSG_TRANSPORT_MAX &&
1214: type != SSH2_MSG_SERVICE_REQUEST &&
1215: type != SSH2_MSG_SERVICE_ACCEPT &&
1216: type != SSH2_MSG_EXT_INFO;
1217: }
1218:
1.201 markus 1219: int
1220: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1221: {
1.201 markus 1222: struct session_state *state = ssh->state;
1.105 markus 1223: struct packet *p;
1.201 markus 1224: u_char type;
1.228 djm 1225: int r, need_rekey;
1.105 markus 1226:
1.228 djm 1227: if (sshbuf_len(state->outgoing_packet) < 6)
1228: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1229: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1230: need_rekey = !ssh_packet_type_is_kex(type) &&
1231: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1232:
1.228 djm 1233: /*
1234: * During rekeying we can only send key exchange messages.
1235: * Queue everything else.
1236: */
1237: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1238: if (need_rekey)
1.297 djm 1239: debug3_f("rekex triggered");
1.228 djm 1240: debug("enqueue packet: %u", type);
1241: p = calloc(1, sizeof(*p));
1242: if (p == NULL)
1243: return SSH_ERR_ALLOC_FAIL;
1244: p->type = type;
1245: p->payload = state->outgoing_packet;
1246: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1247: state->outgoing_packet = sshbuf_new();
1248: if (state->outgoing_packet == NULL)
1249: return SSH_ERR_ALLOC_FAIL;
1250: if (need_rekey) {
1251: /*
1252: * This packet triggered a rekey, so send the
1253: * KEXINIT now.
1254: * NB. reenters this function via kex_start_rekex().
1255: */
1256: return kex_start_rekex(ssh);
1.105 markus 1257: }
1.228 djm 1258: return 0;
1.105 markus 1259: }
1260:
1261: /* rekeying starts with sending KEXINIT */
1262: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1263: state->rekeying = 1;
1.105 markus 1264:
1.201 markus 1265: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1266: return r;
1.105 markus 1267:
1268: /* after a NEWKEYS message we can send the complete queue */
1269: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1270: state->rekeying = 0;
1271: state->rekey_time = monotime();
1272: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1273: type = p->type;
1.228 djm 1274: /*
1275: * If this packet triggers a rekex, then skip the
1276: * remaining packets in the queue for now.
1277: * NB. re-enters this function via kex_start_rekex.
1278: */
1279: if (ssh_packet_need_rekeying(ssh,
1280: sshbuf_len(p->payload))) {
1.297 djm 1281: debug3_f("queued packet triggered rekex");
1.228 djm 1282: return kex_start_rekex(ssh);
1283: }
1.105 markus 1284: debug("dequeue packet: %u", type);
1.201 markus 1285: sshbuf_free(state->outgoing_packet);
1286: state->outgoing_packet = p->payload;
1287: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1288: memset(p, 0, sizeof(*p));
1.186 djm 1289: free(p);
1.201 markus 1290: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1291: return r;
1.105 markus 1292: }
1293: }
1.201 markus 1294: return 0;
1.25 markus 1295: }
1296:
1297: /*
1.16 markus 1298: * Waits until a packet has been received, and returns its type. Note that
1299: * no other data is processed until this returns, so this function should not
1300: * be used during the interactive session.
1301: */
1.1 deraadt 1302:
1.2 provos 1303: int
1.201 markus 1304: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1305: {
1.201 markus 1306: struct session_state *state = ssh->state;
1.222 markus 1307: int len, r, ms_remain;
1.302 ! deraadt 1308: struct pollfd pfd;
1.14 markus 1309: char buf[8192];
1.302 ! deraadt 1310: struct timeval start;
! 1311: struct timespec timespec, *timespecp = NULL;
1.155 deraadt 1312:
1.25 markus 1313: DBG(debug("packet_read()"));
1.14 markus 1314:
1.205 djm 1315: /*
1316: * Since we are blocking, ensure that all written packets have
1317: * been sent.
1318: */
1.210 markus 1319: if ((r = ssh_packet_write_wait(ssh)) != 0)
1320: goto out;
1.14 markus 1321:
1322: /* Stay in the loop until we have received a complete packet. */
1323: for (;;) {
1324: /* Try to read a packet from the buffer. */
1.201 markus 1325: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1326: if (r != 0)
1327: break;
1.14 markus 1328: /* If we got a packet, return it. */
1.201 markus 1329: if (*typep != SSH_MSG_NONE)
1330: break;
1.16 markus 1331: /*
1332: * Otherwise, wait for some data to arrive, add it to the
1333: * buffer, and try again.
1334: */
1.302 ! deraadt 1335: pfd.fd = state->connection_in;
! 1336: pfd.events = POLLIN;
1.16 markus 1337:
1.201 markus 1338: if (state->packet_timeout_ms > 0) {
1339: ms_remain = state->packet_timeout_ms;
1.302 ! deraadt 1340: timespecp = ×pec;
1.154 dtucker 1341: }
1.14 markus 1342: /* Wait for some data to arrive. */
1.154 dtucker 1343: for (;;) {
1.291 markus 1344: if (state->packet_timeout_ms > 0) {
1.302 ! deraadt 1345: ms_to_timespec(×pec, ms_remain);
1.267 dtucker 1346: monotime_tv(&start);
1.154 dtucker 1347: }
1.302 ! deraadt 1348: if ((r = ppoll(&pfd, 1, timespecp, NULL)) >= 0)
1.154 dtucker 1349: break;
1.270 dtucker 1350: if (errno != EAGAIN && errno != EINTR) {
1351: r = SSH_ERR_SYSTEM_ERROR;
1352: goto out;
1353: }
1.291 markus 1354: if (state->packet_timeout_ms <= 0)
1.154 dtucker 1355: continue;
1356: ms_subtract_diff(&start, &ms_remain);
1357: if (ms_remain <= 0) {
1.201 markus 1358: r = 0;
1.154 dtucker 1359: break;
1360: }
1361: }
1.246 djm 1362: if (r == 0) {
1363: r = SSH_ERR_CONN_TIMEOUT;
1364: goto out;
1365: }
1.14 markus 1366: /* Read data from the socket. */
1.222 markus 1367: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1368: if (len == 0) {
1369: r = SSH_ERR_CONN_CLOSED;
1370: goto out;
1371: }
1.286 deraadt 1372: if (len == -1) {
1.210 markus 1373: r = SSH_ERR_SYSTEM_ERROR;
1374: goto out;
1375: }
1.204 djm 1376:
1.14 markus 1377: /* Append it to the buffer. */
1.204 djm 1378: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1379: goto out;
1.14 markus 1380: }
1.210 markus 1381: out:
1.201 markus 1382: return r;
1.1 deraadt 1383: }
1384:
1.77 djm 1385: int
1.201 markus 1386: ssh_packet_read(struct ssh *ssh)
1.77 djm 1387: {
1.201 markus 1388: u_char type;
1389: int r;
1390:
1391: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1.297 djm 1392: fatal_fr(r, "read");
1.201 markus 1393: return type;
1.77 djm 1394: }
1395:
1.16 markus 1396: /*
1397: * Waits until a packet has been received, verifies that its type matches
1398: * that given, and gives a fatal error and exits if there is a mismatch.
1399: */
1.1 deraadt 1400:
1.205 djm 1401: int
1402: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1403: {
1.205 djm 1404: int r;
1405: u_char type;
1.1 deraadt 1406:
1.205 djm 1407: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1408: return r;
1409: if (type != expected_type) {
1410: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1411: "Protocol error: expected packet type %d, got %d",
1.205 djm 1412: expected_type, type)) != 0)
1413: return r;
1414: return SSH_ERR_PROTOCOL_ERROR;
1415: }
1416: return 0;
1.1 deraadt 1417: }
1.14 markus 1418:
1.242 markus 1419: static int
1420: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1421: {
1422: struct session_state *state = ssh->state;
1423: const u_char *cp;
1424: size_t need;
1425: int r;
1426:
1427: if (ssh->kex)
1428: return SSH_ERR_INTERNAL_ERROR;
1429: *typep = SSH_MSG_NONE;
1430: cp = sshbuf_ptr(state->input);
1431: if (state->packlen == 0) {
1432: if (sshbuf_len(state->input) < 4 + 1)
1433: return 0; /* packet is incomplete */
1434: state->packlen = PEEK_U32(cp);
1435: if (state->packlen < 4 + 1 ||
1436: state->packlen > PACKET_MAX_SIZE)
1437: return SSH_ERR_MESSAGE_INCOMPLETE;
1438: }
1439: need = state->packlen + 4;
1440: if (sshbuf_len(state->input) < need)
1441: return 0; /* packet is incomplete */
1442: sshbuf_reset(state->incoming_packet);
1443: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1444: state->packlen)) != 0 ||
1445: (r = sshbuf_consume(state->input, need)) != 0 ||
1446: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1447: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1448: return r;
1449: if (ssh_packet_log_type(*typep))
1.297 djm 1450: debug3_f("type %u", *typep);
1.242 markus 1451: /* sshbuf_dump(state->incoming_packet, stderr); */
1452: /* reset for next packet */
1453: state->packlen = 0;
1454: return r;
1455: }
1456:
1.201 markus 1457: int
1458: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1459: {
1.201 markus 1460: struct session_state *state = ssh->state;
1.40 markus 1461: u_int padlen, need;
1.231 djm 1462: u_char *cp;
1.201 markus 1463: u_int maclen, aadlen = 0, authlen = 0, block_size;
1464: struct sshenc *enc = NULL;
1465: struct sshmac *mac = NULL;
1466: struct sshcomp *comp = NULL;
1.200 markus 1467: int r;
1.201 markus 1468:
1.242 markus 1469: if (state->mux)
1470: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1471:
1.201 markus 1472: *typep = SSH_MSG_NONE;
1473:
1474: if (state->packet_discard)
1475: return 0;
1476:
1477: if (state->newkeys[MODE_IN] != NULL) {
1478: enc = &state->newkeys[MODE_IN]->enc;
1479: mac = &state->newkeys[MODE_IN]->mac;
1480: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1481: /* disable mac for authenticated encryption */
1482: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1483: mac = NULL;
1.25 markus 1484: }
1485: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1486: block_size = enc ? enc->block_size : 8;
1.180 markus 1487: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1488:
1.201 markus 1489: if (aadlen && state->packlen == 0) {
1.235 djm 1490: if (cipher_get_length(state->receive_context,
1.201 markus 1491: &state->packlen, state->p_read.seqnr,
1492: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1493: return 0;
1494: if (state->packlen < 1 + 4 ||
1495: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1496: #ifdef PACKET_DEBUG
1.201 markus 1497: sshbuf_dump(state->input, stderr);
1.178 markus 1498: #endif
1.201 markus 1499: logit("Bad packet length %u.", state->packlen);
1500: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1501: return r;
1.217 djm 1502: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1503: }
1.201 markus 1504: sshbuf_reset(state->incoming_packet);
1505: } else if (state->packlen == 0) {
1.25 markus 1506: /*
1507: * check if input size is less than the cipher block size,
1508: * decrypt first block and extract length of incoming packet
1509: */
1.201 markus 1510: if (sshbuf_len(state->input) < block_size)
1511: return 0;
1512: sshbuf_reset(state->incoming_packet);
1513: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1514: &cp)) != 0)
1515: goto out;
1.235 djm 1516: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1517: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1518: block_size, 0, 0)) != 0)
1519: goto out;
1520: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1521: if (state->packlen < 1 + 4 ||
1522: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1523: #ifdef PACKET_DEBUG
1.201 markus 1524: fprintf(stderr, "input: \n");
1525: sshbuf_dump(state->input, stderr);
1526: fprintf(stderr, "incoming_packet: \n");
1527: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1528: #endif
1.201 markus 1529: logit("Bad packet length %u.", state->packlen);
1.234 markus 1530: return ssh_packet_start_discard(ssh, enc, mac, 0,
1531: PACKET_MAX_SIZE);
1.25 markus 1532: }
1.201 markus 1533: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1534: goto out;
1.25 markus 1535: }
1.201 markus 1536: DBG(debug("input: packet len %u", state->packlen+4));
1537:
1.178 markus 1538: if (aadlen) {
1539: /* only the payload is encrypted */
1.201 markus 1540: need = state->packlen;
1.178 markus 1541: } else {
1542: /*
1543: * the payload size and the payload are encrypted, but we
1544: * have a partial packet of block_size bytes
1545: */
1.201 markus 1546: need = 4 + state->packlen - block_size;
1.178 markus 1547: }
1.180 markus 1548: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1549: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1550: if (need % block_size != 0) {
1551: logit("padding error: need %d block %d mod %d",
1.25 markus 1552: need, block_size, need % block_size);
1.234 markus 1553: return ssh_packet_start_discard(ssh, enc, mac, 0,
1554: PACKET_MAX_SIZE - block_size);
1.158 markus 1555: }
1.25 markus 1556: /*
1557: * check if the entire packet has been received and
1.178 markus 1558: * decrypt into incoming_packet:
1559: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1560: * 'need' bytes are encrypted, followed by either
1561: * 'authlen' bytes of authentication tag or
1.178 markus 1562: * 'maclen' bytes of message authentication code.
1.25 markus 1563: */
1.201 markus 1564: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1565: return 0; /* packet is incomplete */
1.25 markus 1566: #ifdef PACKET_DEBUG
1567: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1568: sshbuf_dump(state->input, stderr);
1.25 markus 1569: #endif
1.231 djm 1570: /* EtM: check mac over encrypted input */
1.201 markus 1571: if (mac && mac->enabled && mac->etm) {
1.231 djm 1572: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1573: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1574: sshbuf_ptr(state->input) + aadlen + need + authlen,
1575: maclen)) != 0) {
1576: if (r == SSH_ERR_MAC_INVALID)
1577: logit("Corrupted MAC on input.");
1.201 markus 1578: goto out;
1.231 djm 1579: }
1.201 markus 1580: }
1581: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1582: &cp)) != 0)
1583: goto out;
1.235 djm 1584: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1585: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1586: goto out;
1587: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1588: goto out;
1.29 markus 1589: if (mac && mac->enabled) {
1.231 djm 1590: /* Not EtM: check MAC over cleartext */
1591: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1592: sshbuf_ptr(state->incoming_packet),
1593: sshbuf_len(state->incoming_packet),
1594: sshbuf_ptr(state->input), maclen)) != 0) {
1595: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1596: goto out;
1.159 markus 1597: logit("Corrupted MAC on input.");
1.247 markus 1598: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1599: return SSH_ERR_INTERNAL_ERROR;
1600: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1601: sshbuf_len(state->incoming_packet),
1.247 markus 1602: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1603: }
1.231 djm 1604: /* Remove MAC from input buffer */
1.201 markus 1605: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1606: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1607: goto out;
1.25 markus 1608: }
1.77 djm 1609: if (seqnr_p != NULL)
1.201 markus 1610: *seqnr_p = state->p_read.seqnr;
1611: if (++state->p_read.seqnr == 0)
1.106 itojun 1612: logit("incoming seqnr wraps around");
1.201 markus 1613: if (++state->p_read.packets == 0)
1614: if (!(ssh->compat & SSH_BUG_NOREKEY))
1615: return SSH_ERR_NEED_REKEY;
1616: state->p_read.blocks += (state->packlen + 4) / block_size;
1617: state->p_read.bytes += state->packlen + 4;
1.25 markus 1618:
1619: /* get padlen */
1.201 markus 1620: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1621: DBG(debug("input: padlen %d", padlen));
1.205 djm 1622: if (padlen < 4) {
1623: if ((r = sshpkt_disconnect(ssh,
1624: "Corrupted padlen %d on input.", padlen)) != 0 ||
1625: (r = ssh_packet_write_wait(ssh)) != 0)
1626: return r;
1627: return SSH_ERR_CONN_CORRUPT;
1628: }
1.25 markus 1629:
1630: /* skip packet size + padlen, discard padding */
1.201 markus 1631: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1632: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1633: goto out;
1.25 markus 1634:
1.201 markus 1635: DBG(debug("input: len before de-compress %zd",
1636: sshbuf_len(state->incoming_packet)));
1.25 markus 1637: if (comp && comp->enabled) {
1.201 markus 1638: sshbuf_reset(state->compression_buffer);
1639: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1640: state->compression_buffer)) != 0)
1641: goto out;
1642: sshbuf_reset(state->incoming_packet);
1643: if ((r = sshbuf_putb(state->incoming_packet,
1644: state->compression_buffer)) != 0)
1645: goto out;
1646: DBG(debug("input: len after de-compress %zd",
1647: sshbuf_len(state->incoming_packet)));
1.25 markus 1648: }
1649: /*
1650: * get packet type, implies consume.
1651: * return length of payload (without type field)
1652: */
1.201 markus 1653: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1654: goto out;
1.226 djm 1655: if (ssh_packet_log_type(*typep))
1656: debug3("receive packet: type %u", *typep);
1.205 djm 1657: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1658: if ((r = sshpkt_disconnect(ssh,
1659: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1660: (r = ssh_packet_write_wait(ssh)) != 0)
1661: return r;
1662: return SSH_ERR_PROTOCOL_ERROR;
1663: }
1.243 djm 1664: if (state->hook_in != NULL &&
1665: (r = state->hook_in(ssh, state->incoming_packet, typep,
1666: state->hook_in_ctx)) != 0)
1667: return r;
1.238 markus 1668: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1669: r = ssh_packet_enable_delayed_compress(ssh);
1670: else
1671: r = 0;
1.25 markus 1672: #ifdef PACKET_DEBUG
1.201 markus 1673: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1674: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1675: #endif
1.62 markus 1676: /* reset for next packet */
1.201 markus 1677: state->packlen = 0;
1.228 djm 1678:
1.301 djm 1679: if ((r = ssh_packet_check_rekey(ssh)) != 0)
1680: return r;
1.201 markus 1681: out:
1682: return r;
1.25 markus 1683: }
1684:
1685: int
1.201 markus 1686: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1687: {
1.201 markus 1688: struct session_state *state = ssh->state;
1.96 deraadt 1689: u_int reason, seqnr;
1.201 markus 1690: int r;
1691: u_char *msg;
1.62 markus 1692:
1.25 markus 1693: for (;;) {
1.201 markus 1694: msg = NULL;
1.249 djm 1695: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1696: if (r != 0)
1697: return r;
1698: if (*typep) {
1699: state->keep_alive_timeouts = 0;
1700: DBG(debug("received packet type %d", *typep));
1701: }
1702: switch (*typep) {
1703: case SSH2_MSG_IGNORE:
1704: debug3("Received SSH2_MSG_IGNORE");
1705: break;
1706: case SSH2_MSG_DEBUG:
1707: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1708: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1709: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1710: free(msg);
1.201 markus 1711: return r;
1.48 stevesk 1712: }
1.249 djm 1713: debug("Remote: %.900s", msg);
1714: free(msg);
1715: break;
1716: case SSH2_MSG_DISCONNECT:
1717: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1718: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1719: return r;
1720: /* Ignore normal client exit notifications */
1721: do_log2(ssh->state->server_side &&
1722: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1723: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1724: "Received disconnect from %s port %d:"
1725: "%u: %.400s", ssh_remote_ipaddr(ssh),
1726: ssh_remote_port(ssh), reason, msg);
1727: free(msg);
1728: return SSH_ERR_DISCONNECTED;
1729: case SSH2_MSG_UNIMPLEMENTED:
1730: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1731: return r;
1732: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1733: seqnr);
1734: break;
1735: default:
1736: return 0;
1.25 markus 1737: }
1738: }
1739: }
1740:
1.16 markus 1741: /*
1742: * Buffers the given amount of input characters. This is intended to be used
1743: * together with packet_read_poll.
1744: */
1.1 deraadt 1745:
1.204 djm 1746: int
1.201 markus 1747: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1748: {
1.201 markus 1749: struct session_state *state = ssh->state;
1750: int r;
1751:
1752: if (state->packet_discard) {
1753: state->keep_alive_timeouts = 0; /* ?? */
1754: if (len >= state->packet_discard) {
1755: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1756: return r;
1.201 markus 1757: }
1758: state->packet_discard -= len;
1.204 djm 1759: return 0;
1.159 markus 1760: }
1.201 markus 1761: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1762: return r;
1763:
1764: return 0;
1.28 markus 1765: }
1766:
1767: int
1.201 markus 1768: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1769: {
1.201 markus 1770: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1771: }
1772:
1.16 markus 1773: /*
1774: * Sends a diagnostic message from the server to the client. This message
1775: * can be sent at any time (but not while constructing another message). The
1776: * message is printed immediately, but only if the client is being executed
1777: * in verbose mode. These messages are primarily intended to ease debugging
1778: * authentication problems. The length of the formatted message must not
1.205 djm 1779: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1780: */
1.2 provos 1781: void
1.201 markus 1782: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1783: {
1.14 markus 1784: char buf[1024];
1785: va_list args;
1.201 markus 1786: int r;
1.39 markus 1787:
1.249 djm 1788: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1789: return;
1.14 markus 1790:
1791: va_start(args, fmt);
1792: vsnprintf(buf, sizeof(buf), fmt, args);
1793: va_end(args);
1.265 djm 1794:
1795: debug3("sending debug message: %s", buf);
1.14 markus 1796:
1.249 djm 1797: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1798: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1799: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1800: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1801: (r = sshpkt_send(ssh)) != 0 ||
1802: (r = ssh_packet_write_wait(ssh)) != 0)
1.297 djm 1803: fatal_fr(r, "send DEBUG");
1.205 djm 1804: }
1805:
1.268 dtucker 1806: void
1807: sshpkt_fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1.245 djm 1808: {
1809: snprintf(s, l, "%.200s%s%s port %d",
1810: ssh->log_preamble ? ssh->log_preamble : "",
1811: ssh->log_preamble ? " " : "",
1812: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1813: }
1814:
1.205 djm 1815: /*
1816: * Pretty-print connection-terminating errors and exit.
1817: */
1.280 djm 1818: static void
1819: sshpkt_vfatal(struct ssh *ssh, int r, const char *fmt, va_list ap)
1.205 djm 1820: {
1.280 djm 1821: char *tag = NULL, remote_id[512];
1.290 djm 1822: int oerrno = errno;
1.245 djm 1823:
1.268 dtucker 1824: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.245 djm 1825:
1.205 djm 1826: switch (r) {
1827: case SSH_ERR_CONN_CLOSED:
1.257 markus 1828: ssh_packet_clear_keys(ssh);
1.245 djm 1829: logdie("Connection closed by %s", remote_id);
1.205 djm 1830: case SSH_ERR_CONN_TIMEOUT:
1.257 markus 1831: ssh_packet_clear_keys(ssh);
1.245 djm 1832: logdie("Connection %s %s timed out",
1833: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1834: case SSH_ERR_DISCONNECTED:
1.257 markus 1835: ssh_packet_clear_keys(ssh);
1.245 djm 1836: logdie("Disconnected from %s", remote_id);
1.212 djm 1837: case SSH_ERR_SYSTEM_ERROR:
1.257 markus 1838: if (errno == ECONNRESET) {
1839: ssh_packet_clear_keys(ssh);
1.245 djm 1840: logdie("Connection reset by %s", remote_id);
1.257 markus 1841: }
1.213 djm 1842: /* FALLTHROUGH */
1843: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1844: case SSH_ERR_NO_MAC_ALG_MATCH:
1845: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1846: case SSH_ERR_NO_KEX_ALG_MATCH:
1847: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1848: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.257 markus 1849: ssh_packet_clear_keys(ssh);
1.290 djm 1850: errno = oerrno;
1.245 djm 1851: logdie("Unable to negotiate with %s: %s. "
1852: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1853: ssh->kex->failed_choice);
1.212 djm 1854: }
1855: /* FALLTHROUGH */
1.205 djm 1856: default:
1.280 djm 1857: if (vasprintf(&tag, fmt, ap) == -1) {
1858: ssh_packet_clear_keys(ssh);
1.297 djm 1859: logdie_f("could not allocate failure message");
1.280 djm 1860: }
1.257 markus 1861: ssh_packet_clear_keys(ssh);
1.290 djm 1862: errno = oerrno;
1.297 djm 1863: logdie_r(r, "%s%sConnection %s %s",
1.205 djm 1864: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.297 djm 1865: ssh->state->server_side ? "from" : "to", remote_id);
1.205 djm 1866: }
1.1 deraadt 1867: }
1868:
1.280 djm 1869: void
1870: sshpkt_fatal(struct ssh *ssh, int r, const char *fmt, ...)
1871: {
1872: va_list ap;
1873:
1874: va_start(ap, fmt);
1875: sshpkt_vfatal(ssh, r, fmt, ap);
1876: /* NOTREACHED */
1877: va_end(ap);
1.297 djm 1878: logdie_f("should have exited");
1.280 djm 1879: }
1880:
1.16 markus 1881: /*
1882: * Logs the error plus constructs and sends a disconnect packet, closes the
1883: * connection, and exits. This function never returns. The error message
1884: * should not contain a newline. The length of the formatted message must
1885: * not exceed 1024 bytes.
1886: */
1.2 provos 1887: void
1.201 markus 1888: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1889: {
1.245 djm 1890: char buf[1024], remote_id[512];
1.14 markus 1891: va_list args;
1892: static int disconnecting = 0;
1.201 markus 1893: int r;
1.97 deraadt 1894:
1.14 markus 1895: if (disconnecting) /* Guard against recursive invocations. */
1896: fatal("packet_disconnect called recursively.");
1897: disconnecting = 1;
1898:
1.16 markus 1899: /*
1900: * Format the message. Note that the caller must make sure the
1901: * message is of limited size.
1902: */
1.268 dtucker 1903: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1904: va_start(args, fmt);
1905: vsnprintf(buf, sizeof(buf), fmt, args);
1906: va_end(args);
1907:
1.99 markus 1908: /* Display the error locally */
1.245 djm 1909: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1910:
1.205 djm 1911: /*
1912: * Send the disconnect message to the other side, and wait
1913: * for it to get sent.
1914: */
1915: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1.280 djm 1916: sshpkt_fatal(ssh, r, "%s", __func__);
1.205 djm 1917:
1918: if ((r = ssh_packet_write_wait(ssh)) != 0)
1.280 djm 1919: sshpkt_fatal(ssh, r, "%s", __func__);
1.14 markus 1920:
1921: /* Close the connection. */
1.201 markus 1922: ssh_packet_close(ssh);
1.112 markus 1923: cleanup_exit(255);
1.1 deraadt 1924: }
1925:
1.205 djm 1926: /*
1927: * Checks if there is any buffered output, and tries to write some of
1928: * the output.
1929: */
1930: int
1.201 markus 1931: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1932: {
1.201 markus 1933: struct session_state *state = ssh->state;
1934: int len = sshbuf_len(state->output);
1.222 markus 1935: int r;
1.97 deraadt 1936:
1.14 markus 1937: if (len > 0) {
1.222 markus 1938: len = write(state->connection_out,
1939: sshbuf_ptr(state->output), len);
1.156 djm 1940: if (len == -1) {
1941: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1942: return 0;
1943: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1944: }
1.222 markus 1945: if (len == 0)
1.205 djm 1946: return SSH_ERR_CONN_CLOSED;
1.201 markus 1947: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1948: return r;
1.14 markus 1949: }
1.205 djm 1950: return 0;
1.1 deraadt 1951: }
1952:
1.16 markus 1953: /*
1954: * Calls packet_write_poll repeatedly until all pending output data has been
1955: * written.
1956: */
1.205 djm 1957: int
1.201 markus 1958: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1959: {
1.205 djm 1960: int ret, r, ms_remain = 0;
1.302 ! deraadt 1961: struct timeval start;
! 1962: struct timespec timespec, *timespecp = NULL;
1.201 markus 1963: struct session_state *state = ssh->state;
1.302 ! deraadt 1964: struct pollfd pfd;
1.56 millert 1965:
1.302 ! deraadt 1966: if ((r = ssh_packet_write_poll(ssh)) != 0)
1.215 djm 1967: return r;
1.201 markus 1968: while (ssh_packet_have_data_to_write(ssh)) {
1.302 ! deraadt 1969: pfd.fd = state->connection_out;
! 1970: pfd.events = POLLOUT;
1.154 dtucker 1971:
1.201 markus 1972: if (state->packet_timeout_ms > 0) {
1973: ms_remain = state->packet_timeout_ms;
1.302 ! deraadt 1974: timespecp = ×pec;
1.154 dtucker 1975: }
1976: for (;;) {
1.291 markus 1977: if (state->packet_timeout_ms > 0) {
1.302 ! deraadt 1978: ms_to_timespec(×pec, ms_remain);
1.267 dtucker 1979: monotime_tv(&start);
1.154 dtucker 1980: }
1.302 ! deraadt 1981: if ((ret = ppoll(&pfd, 1, timespecp, NULL)) >= 0)
1.154 dtucker 1982: break;
1.161 andreas 1983: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1984: break;
1.291 markus 1985: if (state->packet_timeout_ms <= 0)
1.154 dtucker 1986: continue;
1987: ms_subtract_diff(&start, &ms_remain);
1988: if (ms_remain <= 0) {
1989: ret = 0;
1990: break;
1991: }
1992: }
1.302 ! deraadt 1993: if (ret == 0)
1.205 djm 1994: return SSH_ERR_CONN_TIMEOUT;
1.302 ! deraadt 1995: if ((r = ssh_packet_write_poll(ssh)) != 0)
1.205 djm 1996: return r;
1.14 markus 1997: }
1.205 djm 1998: return 0;
1.1 deraadt 1999: }
2000:
2001: /* Returns true if there is buffered data to write to the connection. */
2002:
1.2 provos 2003: int
1.201 markus 2004: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 2005: {
1.201 markus 2006: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 2007: }
2008:
2009: /* Returns true if there is not too much data to write to the connection. */
2010:
1.2 provos 2011: int
1.201 markus 2012: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 2013: {
1.201 markus 2014: if (ssh->state->interactive_mode)
2015: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 2016: else
1.201 markus 2017: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 2018: }
2019:
1.201 markus 2020: void
2021: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 2022: {
1.263 djm 2023: if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
1.101 markus 2024: return;
1.298 djm 2025: set_sock_tos(ssh->state->connection_in, tos);
1.101 markus 2026: }
2027:
1.1 deraadt 2028: /* Informs that the current session is interactive. Sets IP flags for that. */
2029:
1.2 provos 2030: void
1.201 markus 2031: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2032: {
1.201 markus 2033: struct session_state *state = ssh->state;
2034:
2035: if (state->set_interactive_called)
1.43 markus 2036: return;
1.201 markus 2037: state->set_interactive_called = 1;
1.1 deraadt 2038:
1.14 markus 2039: /* Record that we are in interactive mode. */
1.201 markus 2040: state->interactive_mode = interactive;
1.1 deraadt 2041:
1.19 markus 2042: /* Only set socket options if using a socket. */
1.201 markus 2043: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2044: return;
1.201 markus 2045: set_nodelay(state->connection_in);
1.298 djm 2046: ssh_packet_set_tos(ssh, interactive ? qos_interactive : qos_bulk);
1.1 deraadt 2047: }
2048:
2049: /* Returns true if the current connection is interactive. */
2050:
1.2 provos 2051: int
1.201 markus 2052: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2053: {
1.201 markus 2054: return ssh->state->interactive_mode;
1.12 markus 2055: }
2056:
1.113 deraadt 2057: int
1.201 markus 2058: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2059: {
1.201 markus 2060: struct session_state *state = ssh->state;
2061:
2062: if (state->set_maxsize_called) {
1.106 itojun 2063: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2064: state->max_packet_size, s);
1.14 markus 2065: return -1;
2066: }
2067: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2068: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2069: return -1;
2070: }
1.201 markus 2071: state->set_maxsize_called = 1;
1.66 markus 2072: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2073: state->max_packet_size = s;
1.14 markus 2074: return s;
1.53 markus 2075: }
2076:
1.161 andreas 2077: int
1.201 markus 2078: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2079: {
1.201 markus 2080: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2081: }
2082:
2083: void
1.201 markus 2084: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2085: {
1.201 markus 2086: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2087: }
2088:
2089: u_int
1.201 markus 2090: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2091: {
1.201 markus 2092: return ssh->state->max_packet_size;
1.71 markus 2093: }
2094:
1.105 markus 2095: void
1.244 dtucker 2096: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2097: {
1.244 dtucker 2098: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2099: (unsigned int)seconds);
1.201 markus 2100: ssh->state->rekey_limit = bytes;
2101: ssh->state->rekey_interval = seconds;
1.184 dtucker 2102: }
2103:
2104: time_t
1.201 markus 2105: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2106: {
2107: time_t seconds;
2108:
1.201 markus 2109: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2110: monotime();
1.185 dtucker 2111: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2112: }
2113:
2114: void
1.201 markus 2115: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2116: {
1.201 markus 2117: ssh->state->server_side = 1;
1.278 djm 2118: ssh->kex->server = 1; /* XXX unify? */
1.118 markus 2119: }
2120:
2121: void
1.201 markus 2122: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2123: {
1.201 markus 2124: ssh->state->after_authentication = 1;
1.161 andreas 2125: }
2126:
2127: void *
1.201 markus 2128: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2129: {
1.201 markus 2130: return (void *)ssh->state->input;
1.161 andreas 2131: }
2132:
2133: void *
1.201 markus 2134: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2135: {
1.201 markus 2136: return (void *)ssh->state->output;
1.166 andreas 2137: }
2138:
1.196 markus 2139: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2140: static int
2141: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2142: {
1.239 djm 2143: int r;
1.196 markus 2144:
1.297 djm 2145: debug_f("called");
1.196 markus 2146: /* This was set in net child, but is not visible in user child */
1.201 markus 2147: ssh->state->after_authentication = 1;
2148: ssh->state->rekeying = 0;
1.239 djm 2149: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2150: return r;
1.201 markus 2151: return 0;
2152: }
2153:
2154: /* Packet state (de-)serialization for privsep */
2155:
2156: /* turn kex into a blob for packet state serialization */
2157: static int
2158: kex_to_blob(struct sshbuf *m, struct kex *kex)
2159: {
2160: int r;
2161:
1.299 djm 2162: if ((r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
1.269 djm 2163: (r = sshbuf_put_cstring(m, kex->hostkey_alg)) != 0 ||
1.201 markus 2164: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
1.269 djm 2165: (r = sshbuf_put_u32(m, kex->hostkey_nid)) != 0 ||
1.201 markus 2166: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2167: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2168: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
1.278 djm 2169: (r = sshbuf_put_stringb(m, kex->client_version)) != 0 ||
2170: (r = sshbuf_put_stringb(m, kex->server_version)) != 0 ||
1.299 djm 2171: (r = sshbuf_put_stringb(m, kex->session_id)) != 0 ||
1.278 djm 2172: (r = sshbuf_put_u32(m, kex->flags)) != 0)
1.201 markus 2173: return r;
2174: return 0;
2175: }
2176:
2177: /* turn key exchange results into a blob for packet state serialization */
2178: static int
2179: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2180: {
2181: struct sshbuf *b;
2182: struct sshcipher_ctx *cc;
2183: struct sshcomp *comp;
2184: struct sshenc *enc;
2185: struct sshmac *mac;
2186: struct newkeys *newkey;
2187: int r;
2188:
2189: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2190: return SSH_ERR_INTERNAL_ERROR;
2191: enc = &newkey->enc;
2192: mac = &newkey->mac;
2193: comp = &newkey->comp;
1.235 djm 2194: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2195: ssh->state->receive_context;
1.201 markus 2196: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2197: return r;
2198: if ((b = sshbuf_new()) == NULL)
2199: return SSH_ERR_ALLOC_FAIL;
2200: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2201: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2202: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2203: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2204: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2205: goto out;
2206: if (cipher_authlen(enc->cipher) == 0) {
2207: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2208: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2209: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2210: goto out;
2211: }
2212: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2213: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2214: goto out;
2215: r = sshbuf_put_stringb(m, b);
2216: out:
1.221 mmcc 2217: sshbuf_free(b);
1.201 markus 2218: return r;
2219: }
2220:
2221: /* serialize packet state into a blob */
2222: int
2223: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2224: {
2225: struct session_state *state = ssh->state;
1.249 djm 2226: int r;
1.201 markus 2227:
1.249 djm 2228: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2229: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2230: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2231: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2232: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2233: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2234: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2235: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2236: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2237: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2238: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2239: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2240: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2241: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2242: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 2243: return r;
1.201 markus 2244:
2245: return 0;
2246: }
2247:
2248: /* restore key exchange results from blob for packet state de-serialization */
2249: static int
2250: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2251: {
2252: struct sshbuf *b = NULL;
2253: struct sshcomp *comp;
2254: struct sshenc *enc;
2255: struct sshmac *mac;
2256: struct newkeys *newkey = NULL;
2257: size_t keylen, ivlen, maclen;
2258: int r;
2259:
2260: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2261: r = SSH_ERR_ALLOC_FAIL;
2262: goto out;
2263: }
2264: if ((r = sshbuf_froms(m, &b)) != 0)
2265: goto out;
2266: #ifdef DEBUG_PK
2267: sshbuf_dump(b, stderr);
2268: #endif
2269: enc = &newkey->enc;
2270: mac = &newkey->mac;
2271: comp = &newkey->comp;
2272:
2273: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2274: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2275: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2276: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2277: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2278: goto out;
1.262 djm 2279: if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2280: r = SSH_ERR_INVALID_FORMAT;
2281: goto out;
2282: }
1.201 markus 2283: if (cipher_authlen(enc->cipher) == 0) {
2284: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2285: goto out;
2286: if ((r = mac_setup(mac, mac->name)) != 0)
2287: goto out;
2288: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2289: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2290: goto out;
2291: if (maclen > mac->key_len) {
2292: r = SSH_ERR_INVALID_FORMAT;
2293: goto out;
2294: }
2295: mac->key_len = maclen;
2296: }
2297: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2298: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2299: goto out;
2300: if (sshbuf_len(b) != 0) {
2301: r = SSH_ERR_INVALID_FORMAT;
2302: goto out;
2303: }
2304: enc->key_len = keylen;
2305: enc->iv_len = ivlen;
2306: ssh->kex->newkeys[mode] = newkey;
2307: newkey = NULL;
2308: r = 0;
2309: out:
1.219 mmcc 2310: free(newkey);
1.221 mmcc 2311: sshbuf_free(b);
1.201 markus 2312: return r;
2313: }
2314:
2315: /* restore kex from blob for packet state de-serialization */
2316: static int
2317: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2318: {
2319: struct kex *kex;
2320: int r;
2321:
1.278 djm 2322: if ((kex = kex_new()) == NULL)
2323: return SSH_ERR_ALLOC_FAIL;
1.299 djm 2324: if ((r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
1.269 djm 2325: (r = sshbuf_get_cstring(m, &kex->hostkey_alg, NULL)) != 0 ||
1.201 markus 2326: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
1.269 djm 2327: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_nid)) != 0 ||
1.201 markus 2328: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2329: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2330: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
1.278 djm 2331: (r = sshbuf_get_stringb(m, kex->client_version)) != 0 ||
2332: (r = sshbuf_get_stringb(m, kex->server_version)) != 0 ||
1.299 djm 2333: (r = sshbuf_get_stringb(m, kex->session_id)) != 0 ||
1.278 djm 2334: (r = sshbuf_get_u32(m, &kex->flags)) != 0)
1.201 markus 2335: goto out;
2336: kex->server = 1;
2337: kex->done = 1;
2338: r = 0;
2339: out:
2340: if (r != 0 || kexp == NULL) {
1.278 djm 2341: kex_free(kex);
1.201 markus 2342: if (kexp != NULL)
2343: *kexp = NULL;
2344: } else {
1.278 djm 2345: kex_free(*kexp);
1.201 markus 2346: *kexp = kex;
2347: }
2348: return r;
2349: }
2350:
2351: /*
2352: * Restore packet state from content of blob 'm' (de-serialization).
2353: * Note that 'm' will be partially consumed on parsing or any other errors.
2354: */
2355: int
2356: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2357: {
2358: struct session_state *state = ssh->state;
1.254 djm 2359: const u_char *input, *output;
2360: size_t ilen, olen;
1.201 markus 2361: int r;
2362:
1.249 djm 2363: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2364: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2365: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2366: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2367: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2368: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2369: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2370: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2371: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2372: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2373: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2374: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2375: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2376: return r;
2377: /*
1.296 djm 2378: * We set the time here so that in post-auth privsep child we
1.249 djm 2379: * count from the completion of the authentication.
2380: */
2381: state->rekey_time = monotime();
2382: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2383: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2384: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2385: return r;
1.201 markus 2386:
1.239 djm 2387: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2388: return r;
2389:
2390: sshbuf_reset(state->input);
2391: sshbuf_reset(state->output);
2392: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2393: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2394: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2395: (r = sshbuf_put(state->output, output, olen)) != 0)
2396: return r;
2397:
2398: if (sshbuf_len(m))
2399: return SSH_ERR_INVALID_FORMAT;
1.297 djm 2400: debug3_f("done");
1.201 markus 2401: return 0;
2402: }
2403:
2404: /* NEW API */
2405:
2406: /* put data to the outgoing packet */
2407:
2408: int
2409: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2410: {
2411: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2412: }
2413:
2414: int
2415: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2416: {
2417: return sshbuf_putb(ssh->state->outgoing_packet, b);
2418: }
2419:
2420: int
2421: sshpkt_put_u8(struct ssh *ssh, u_char val)
2422: {
2423: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2424: }
2425:
2426: int
2427: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2428: {
2429: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2430: }
2431:
2432: int
2433: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2434: {
2435: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2436: }
2437:
2438: int
2439: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2440: {
2441: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2442: }
2443:
2444: int
2445: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2446: {
2447: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2448: }
2449:
2450: int
2451: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2452: {
2453: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2454: }
2455:
1.211 djm 2456: #ifdef WITH_OPENSSL
1.201 markus 2457: int
2458: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2459: {
2460: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2461: }
2462:
2463:
2464: int
2465: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2466: {
2467: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2468: }
1.211 djm 2469: #endif /* WITH_OPENSSL */
1.201 markus 2470:
2471: /* fetch data from the incoming packet */
2472:
2473: int
2474: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2475: {
2476: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2477: }
2478:
2479: int
2480: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2481: {
2482: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2483: }
2484:
2485: int
2486: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2487: {
2488: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2489: }
2490:
2491: int
2492: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2493: {
2494: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2495: }
2496:
2497: int
2498: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2499: {
2500: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2501: }
2502:
2503: int
2504: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2505: {
2506: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2507: }
2508:
2509: int
1.264 djm 2510: sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2511: {
2512: return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2513: }
2514:
2515: int
1.201 markus 2516: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2517: {
2518: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
1.282 djm 2519: }
2520:
2521: int
2522: sshpkt_getb_froms(struct ssh *ssh, struct sshbuf **valp)
2523: {
2524: return sshbuf_froms(ssh->state->incoming_packet, valp);
1.201 markus 2525: }
2526:
1.211 djm 2527: #ifdef WITH_OPENSSL
1.201 markus 2528: int
2529: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2530: {
2531: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2532: }
2533:
2534: int
1.281 djm 2535: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM **valp)
1.201 markus 2536: {
1.281 djm 2537: return sshbuf_get_bignum2(ssh->state->incoming_packet, valp);
1.201 markus 2538: }
1.211 djm 2539: #endif /* WITH_OPENSSL */
1.201 markus 2540:
2541: int
2542: sshpkt_get_end(struct ssh *ssh)
2543: {
2544: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2545: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2546: return 0;
2547: }
2548:
2549: const u_char *
2550: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2551: {
2552: if (lenp != NULL)
2553: *lenp = sshbuf_len(ssh->state->incoming_packet);
2554: return sshbuf_ptr(ssh->state->incoming_packet);
2555: }
2556:
2557: /* start a new packet */
2558:
2559: int
2560: sshpkt_start(struct ssh *ssh, u_char type)
2561: {
1.249 djm 2562: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2563:
2564: DBG(debug("packet_start[%d]", type));
1.249 djm 2565: memset(buf, 0, sizeof(buf));
2566: buf[sizeof(buf) - 1] = type;
1.201 markus 2567: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2568: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2569: }
2570:
1.242 markus 2571: static int
2572: ssh_packet_send_mux(struct ssh *ssh)
2573: {
2574: struct session_state *state = ssh->state;
2575: u_char type, *cp;
2576: size_t len;
2577: int r;
2578:
2579: if (ssh->kex)
2580: return SSH_ERR_INTERNAL_ERROR;
2581: len = sshbuf_len(state->outgoing_packet);
2582: if (len < 6)
2583: return SSH_ERR_INTERNAL_ERROR;
2584: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2585: type = cp[5];
2586: if (ssh_packet_log_type(type))
1.297 djm 2587: debug3_f("type %u", type);
1.242 markus 2588: /* drop everything, but the connection protocol */
2589: if (type >= SSH2_MSG_CONNECTION_MIN &&
2590: type <= SSH2_MSG_CONNECTION_MAX) {
2591: POKE_U32(cp, len - 4);
2592: if ((r = sshbuf_putb(state->output,
2593: state->outgoing_packet)) != 0)
2594: return r;
2595: /* sshbuf_dump(state->output, stderr); */
2596: }
2597: sshbuf_reset(state->outgoing_packet);
1.264 djm 2598: return 0;
2599: }
2600:
2601: /*
2602: * 9.2. Ignored Data Message
2603: *
2604: * byte SSH_MSG_IGNORE
2605: * string data
2606: *
2607: * All implementations MUST understand (and ignore) this message at any
2608: * time (after receiving the protocol version). No implementation is
2609: * required to send them. This message can be used as an additional
2610: * protection measure against advanced traffic analysis techniques.
2611: */
2612: int
2613: sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2614: {
2615: u_int32_t rnd = 0;
2616: int r;
2617: u_int i;
2618:
2619: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2620: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2621: return r;
2622: for (i = 0; i < nbytes; i++) {
2623: if (i % 4 == 0)
2624: rnd = arc4random();
2625: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2626: return r;
2627: rnd >>= 8;
2628: }
1.242 markus 2629: return 0;
2630: }
2631:
1.201 markus 2632: /* send it */
2633:
2634: int
2635: sshpkt_send(struct ssh *ssh)
2636: {
1.242 markus 2637: if (ssh->state && ssh->state->mux)
2638: return ssh_packet_send_mux(ssh);
1.249 djm 2639: return ssh_packet_send2(ssh);
1.201 markus 2640: }
2641:
2642: int
2643: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2644: {
2645: char buf[1024];
2646: va_list args;
2647: int r;
2648:
2649: va_start(args, fmt);
2650: vsnprintf(buf, sizeof(buf), fmt, args);
2651: va_end(args);
2652:
1.249 djm 2653: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2654: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2655: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2656: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2657: (r = sshpkt_send(ssh)) != 0)
2658: return r;
1.201 markus 2659: return 0;
2660: }
2661:
2662: /* roundup current message to pad bytes */
2663: int
2664: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2665: {
2666: ssh->state->extra_pad = pad;
2667: return 0;
1.1 deraadt 2668: }
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