Annotation of src/usr.bin/ssh/packet.c, Revision 1.299
1.299 ! djm 1: /* $OpenBSD: packet.c,v 1.298 2020/11/27 00:49:58 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 &&
667: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
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, "
869: "output %llu bytes %llu blocks", dir,
1.257 markus 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);
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 &&
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:
1.16 markus 985: /*
1.118 markus 986: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 987: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 988: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
989: */
1.201 markus 990: static int
991: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 992: {
1.201 markus 993: struct session_state *state = ssh->state;
994: struct sshcomp *comp = NULL;
995: int r, mode;
1.118 markus 996:
997: /*
998: * Remember that we are past the authentication step, so rekeying
1.275 sf 999: * with COMP_DELAYED will turn on compression immediately.
1.118 markus 1000: */
1.201 markus 1001: state->after_authentication = 1;
1.118 markus 1002: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 1003: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 1004: if (state->newkeys[mode] == NULL)
1.145 markus 1005: continue;
1.201 markus 1006: comp = &state->newkeys[mode]->comp;
1.275 sf 1007: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 1008: if ((r = ssh_packet_init_compression(ssh)) != 0)
1009: return r;
1010: if (mode == MODE_OUT) {
1011: if ((r = start_compression_out(ssh, 6)) != 0)
1012: return r;
1013: } else {
1014: if ((r = start_compression_in(ssh)) != 0)
1015: return r;
1016: }
1.118 markus 1017: comp->enabled = 1;
1018: }
1019: }
1.201 markus 1020: return 0;
1.118 markus 1021: }
1022:
1.226 djm 1023: /* Used to mute debug logging for noisy packet types */
1.242 markus 1024: int
1.226 djm 1025: ssh_packet_log_type(u_char type)
1026: {
1027: switch (type) {
1028: case SSH2_MSG_CHANNEL_DATA:
1029: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1030: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1031: return 0;
1032: default:
1033: return 1;
1034: }
1035: }
1036:
1.118 markus 1037: /*
1.25 markus 1038: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1039: */
1.201 markus 1040: int
1041: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1042: {
1.201 markus 1043: struct session_state *state = ssh->state;
1.200 markus 1044: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1045: u_char tmp, padlen, pad = 0;
1.201 markus 1046: u_int authlen = 0, aadlen = 0;
1047: u_int len;
1048: struct sshenc *enc = NULL;
1049: struct sshmac *mac = NULL;
1050: struct sshcomp *comp = NULL;
1051: int r, block_size;
1052:
1053: if (state->newkeys[MODE_OUT] != NULL) {
1054: enc = &state->newkeys[MODE_OUT]->enc;
1055: mac = &state->newkeys[MODE_OUT]->mac;
1056: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1057: /* disable mac for authenticated encryption */
1058: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1059: mac = NULL;
1.25 markus 1060: }
1.88 markus 1061: block_size = enc ? enc->block_size : 8;
1.180 markus 1062: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1063:
1.201 markus 1064: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1065: if (ssh_packet_log_type(type))
1066: debug3("send packet: type %u", type);
1.25 markus 1067: #ifdef PACKET_DEBUG
1068: fprintf(stderr, "plain: ");
1.201 markus 1069: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1070: #endif
1071:
1072: if (comp && comp->enabled) {
1.201 markus 1073: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1074: /* skip header, compress only payload */
1.201 markus 1075: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1076: goto out;
1077: sshbuf_reset(state->compression_buffer);
1078: if ((r = compress_buffer(ssh, state->outgoing_packet,
1079: state->compression_buffer)) != 0)
1080: goto out;
1081: sshbuf_reset(state->outgoing_packet);
1082: if ((r = sshbuf_put(state->outgoing_packet,
1083: "\0\0\0\0\0", 5)) != 0 ||
1084: (r = sshbuf_putb(state->outgoing_packet,
1085: state->compression_buffer)) != 0)
1086: goto out;
1087: DBG(debug("compression: raw %d compressed %zd", len,
1088: sshbuf_len(state->outgoing_packet)));
1.25 markus 1089: }
1090:
1091: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1092: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1093:
1094: /*
1095: * calc size of padding, alloc space, get random data,
1096: * minimum padding is 4 bytes
1097: */
1.178 markus 1098: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1099: padlen = block_size - (len % block_size);
1100: if (padlen < 4)
1101: padlen += block_size;
1.201 markus 1102: if (state->extra_pad) {
1.233 djm 1103: tmp = state->extra_pad;
1.201 markus 1104: state->extra_pad =
1.237 deraadt 1105: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1106: /* check if roundup overflowed */
1107: if (state->extra_pad < tmp)
1108: return SSH_ERR_INVALID_ARGUMENT;
1109: tmp = (len + padlen) % state->extra_pad;
1110: /* Check whether pad calculation below will underflow */
1111: if (tmp > state->extra_pad)
1112: return SSH_ERR_INVALID_ARGUMENT;
1113: pad = state->extra_pad - tmp;
1.297 djm 1114: DBG(debug3_f("adding %d (len %d padlen %d extra_pad %d)",
1115: pad, len, padlen, state->extra_pad));
1.233 djm 1116: tmp = padlen;
1.71 markus 1117: padlen += pad;
1.233 djm 1118: /* Check whether padlen calculation overflowed */
1119: if (padlen < tmp)
1120: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1121: state->extra_pad = 0;
1.71 markus 1122: }
1.201 markus 1123: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1124: goto out;
1.235 djm 1125: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1126: /* random padding */
1.201 markus 1127: arc4random_buf(cp, padlen);
1.32 markus 1128: } else {
1129: /* clear padding */
1.192 djm 1130: explicit_bzero(cp, padlen);
1.25 markus 1131: }
1.178 markus 1132: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1133: len = sshbuf_len(state->outgoing_packet);
1134: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1135: if (cp == NULL) {
1136: r = SSH_ERR_INTERNAL_ERROR;
1137: goto out;
1138: }
1.25 markus 1139: /* packet_length includes payload, padding and padding length field */
1.201 markus 1140: POKE_U32(cp, len - 4);
1.89 markus 1141: cp[4] = padlen;
1.178 markus 1142: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1143: len, padlen, aadlen));
1.25 markus 1144:
1145: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1146: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1147: if ((r = mac_compute(mac, state->p_send.seqnr,
1148: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1149: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1150: goto out;
1151: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1152: }
1153: /* encrypt packet and append to output buffer. */
1.201 markus 1154: if ((r = sshbuf_reserve(state->output,
1155: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1156: goto out;
1.235 djm 1157: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1158: sshbuf_ptr(state->outgoing_packet),
1159: len - aadlen, aadlen, authlen)) != 0)
1160: goto out;
1.25 markus 1161: /* append unencrypted MAC */
1.178 markus 1162: if (mac && mac->enabled) {
1163: if (mac->etm) {
1164: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1165: if ((r = mac_compute(mac, state->p_send.seqnr,
1166: cp, len, macbuf, sizeof(macbuf))) != 0)
1167: goto out;
1.178 markus 1168: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1169: state->p_send.seqnr));
1.178 markus 1170: }
1.201 markus 1171: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1172: goto out;
1.178 markus 1173: }
1.25 markus 1174: #ifdef PACKET_DEBUG
1175: fprintf(stderr, "encrypted: ");
1.201 markus 1176: sshbuf_dump(state->output, stderr);
1.25 markus 1177: #endif
1.29 markus 1178: /* increment sequence number for outgoing packets */
1.201 markus 1179: if (++state->p_send.seqnr == 0)
1.106 itojun 1180: logit("outgoing seqnr wraps around");
1.201 markus 1181: if (++state->p_send.packets == 0)
1182: if (!(ssh->compat & SSH_BUG_NOREKEY))
1183: return SSH_ERR_NEED_REKEY;
1184: state->p_send.blocks += len / block_size;
1185: state->p_send.bytes += len;
1186: sshbuf_reset(state->outgoing_packet);
1.25 markus 1187:
1.57 markus 1188: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1189: r = ssh_set_newkeys(ssh, MODE_OUT);
1190: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1191: r = ssh_packet_enable_delayed_compress(ssh);
1192: else
1193: r = 0;
1194: out:
1195: return r;
1.25 markus 1196: }
1197:
1.228 djm 1198: /* returns non-zero if the specified packet type is usec by KEX */
1199: static int
1200: ssh_packet_type_is_kex(u_char type)
1201: {
1202: return
1203: type >= SSH2_MSG_TRANSPORT_MIN &&
1204: type <= SSH2_MSG_TRANSPORT_MAX &&
1205: type != SSH2_MSG_SERVICE_REQUEST &&
1206: type != SSH2_MSG_SERVICE_ACCEPT &&
1207: type != SSH2_MSG_EXT_INFO;
1208: }
1209:
1.201 markus 1210: int
1211: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1212: {
1.201 markus 1213: struct session_state *state = ssh->state;
1.105 markus 1214: struct packet *p;
1.201 markus 1215: u_char type;
1.228 djm 1216: int r, need_rekey;
1.105 markus 1217:
1.228 djm 1218: if (sshbuf_len(state->outgoing_packet) < 6)
1219: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1220: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1221: need_rekey = !ssh_packet_type_is_kex(type) &&
1222: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1223:
1.228 djm 1224: /*
1225: * During rekeying we can only send key exchange messages.
1226: * Queue everything else.
1227: */
1228: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1229: if (need_rekey)
1.297 djm 1230: debug3_f("rekex triggered");
1.228 djm 1231: debug("enqueue packet: %u", type);
1232: p = calloc(1, sizeof(*p));
1233: if (p == NULL)
1234: return SSH_ERR_ALLOC_FAIL;
1235: p->type = type;
1236: p->payload = state->outgoing_packet;
1237: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1238: state->outgoing_packet = sshbuf_new();
1239: if (state->outgoing_packet == NULL)
1240: return SSH_ERR_ALLOC_FAIL;
1241: if (need_rekey) {
1242: /*
1243: * This packet triggered a rekey, so send the
1244: * KEXINIT now.
1245: * NB. reenters this function via kex_start_rekex().
1246: */
1247: return kex_start_rekex(ssh);
1.105 markus 1248: }
1.228 djm 1249: return 0;
1.105 markus 1250: }
1251:
1252: /* rekeying starts with sending KEXINIT */
1253: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1254: state->rekeying = 1;
1.105 markus 1255:
1.201 markus 1256: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1257: return r;
1.105 markus 1258:
1259: /* after a NEWKEYS message we can send the complete queue */
1260: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1261: state->rekeying = 0;
1262: state->rekey_time = monotime();
1263: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1264: type = p->type;
1.228 djm 1265: /*
1266: * If this packet triggers a rekex, then skip the
1267: * remaining packets in the queue for now.
1268: * NB. re-enters this function via kex_start_rekex.
1269: */
1270: if (ssh_packet_need_rekeying(ssh,
1271: sshbuf_len(p->payload))) {
1.297 djm 1272: debug3_f("queued packet triggered rekex");
1.228 djm 1273: return kex_start_rekex(ssh);
1274: }
1.105 markus 1275: debug("dequeue packet: %u", type);
1.201 markus 1276: sshbuf_free(state->outgoing_packet);
1277: state->outgoing_packet = p->payload;
1278: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1279: memset(p, 0, sizeof(*p));
1.186 djm 1280: free(p);
1.201 markus 1281: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1282: return r;
1.105 markus 1283: }
1284: }
1.201 markus 1285: return 0;
1.25 markus 1286: }
1287:
1288: /*
1.16 markus 1289: * Waits until a packet has been received, and returns its type. Note that
1290: * no other data is processed until this returns, so this function should not
1291: * be used during the interactive session.
1292: */
1.1 deraadt 1293:
1.2 provos 1294: int
1.201 markus 1295: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1296: {
1.201 markus 1297: struct session_state *state = ssh->state;
1.222 markus 1298: int len, r, ms_remain;
1.56 millert 1299: fd_set *setp;
1.14 markus 1300: char buf[8192];
1.155 deraadt 1301: struct timeval timeout, start, *timeoutp = NULL;
1302:
1.25 markus 1303: DBG(debug("packet_read()"));
1.14 markus 1304:
1.214 deraadt 1305: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1306: NFDBITS), sizeof(fd_mask));
1.201 markus 1307: if (setp == NULL)
1308: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1309:
1.205 djm 1310: /*
1311: * Since we are blocking, ensure that all written packets have
1312: * been sent.
1313: */
1.210 markus 1314: if ((r = ssh_packet_write_wait(ssh)) != 0)
1315: goto out;
1.14 markus 1316:
1317: /* Stay in the loop until we have received a complete packet. */
1318: for (;;) {
1319: /* Try to read a packet from the buffer. */
1.201 markus 1320: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1321: if (r != 0)
1322: break;
1.14 markus 1323: /* If we got a packet, return it. */
1.201 markus 1324: if (*typep != SSH_MSG_NONE)
1325: break;
1.16 markus 1326: /*
1327: * Otherwise, wait for some data to arrive, add it to the
1328: * buffer, and try again.
1329: */
1.201 markus 1330: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1331: NFDBITS) * sizeof(fd_mask));
1.201 markus 1332: FD_SET(state->connection_in, setp);
1.16 markus 1333:
1.201 markus 1334: if (state->packet_timeout_ms > 0) {
1335: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1336: timeoutp = &timeout;
1337: }
1.14 markus 1338: /* Wait for some data to arrive. */
1.154 dtucker 1339: for (;;) {
1.291 markus 1340: if (state->packet_timeout_ms > 0) {
1.154 dtucker 1341: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1342: monotime_tv(&start);
1.154 dtucker 1343: }
1.201 markus 1344: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1345: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1346: break;
1.270 dtucker 1347: if (errno != EAGAIN && errno != EINTR) {
1348: r = SSH_ERR_SYSTEM_ERROR;
1349: goto out;
1350: }
1.291 markus 1351: if (state->packet_timeout_ms <= 0)
1.154 dtucker 1352: continue;
1353: ms_subtract_diff(&start, &ms_remain);
1354: if (ms_remain <= 0) {
1.201 markus 1355: r = 0;
1.154 dtucker 1356: break;
1357: }
1358: }
1.246 djm 1359: if (r == 0) {
1360: r = SSH_ERR_CONN_TIMEOUT;
1361: goto out;
1362: }
1.14 markus 1363: /* Read data from the socket. */
1.222 markus 1364: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1365: if (len == 0) {
1366: r = SSH_ERR_CONN_CLOSED;
1367: goto out;
1368: }
1.286 deraadt 1369: if (len == -1) {
1.210 markus 1370: r = SSH_ERR_SYSTEM_ERROR;
1371: goto out;
1372: }
1.204 djm 1373:
1.14 markus 1374: /* Append it to the buffer. */
1.204 djm 1375: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1376: goto out;
1.14 markus 1377: }
1.210 markus 1378: out:
1.201 markus 1379: free(setp);
1380: return r;
1.1 deraadt 1381: }
1382:
1.77 djm 1383: int
1.201 markus 1384: ssh_packet_read(struct ssh *ssh)
1.77 djm 1385: {
1.201 markus 1386: u_char type;
1387: int r;
1388:
1389: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1.297 djm 1390: fatal_fr(r, "read");
1.201 markus 1391: return type;
1.77 djm 1392: }
1393:
1.16 markus 1394: /*
1395: * Waits until a packet has been received, verifies that its type matches
1396: * that given, and gives a fatal error and exits if there is a mismatch.
1397: */
1.1 deraadt 1398:
1.205 djm 1399: int
1400: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1401: {
1.205 djm 1402: int r;
1403: u_char type;
1.1 deraadt 1404:
1.205 djm 1405: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1406: return r;
1407: if (type != expected_type) {
1408: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1409: "Protocol error: expected packet type %d, got %d",
1.205 djm 1410: expected_type, type)) != 0)
1411: return r;
1412: return SSH_ERR_PROTOCOL_ERROR;
1413: }
1414: return 0;
1.1 deraadt 1415: }
1.14 markus 1416:
1.242 markus 1417: static int
1418: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1419: {
1420: struct session_state *state = ssh->state;
1421: const u_char *cp;
1422: size_t need;
1423: int r;
1424:
1425: if (ssh->kex)
1426: return SSH_ERR_INTERNAL_ERROR;
1427: *typep = SSH_MSG_NONE;
1428: cp = sshbuf_ptr(state->input);
1429: if (state->packlen == 0) {
1430: if (sshbuf_len(state->input) < 4 + 1)
1431: return 0; /* packet is incomplete */
1432: state->packlen = PEEK_U32(cp);
1433: if (state->packlen < 4 + 1 ||
1434: state->packlen > PACKET_MAX_SIZE)
1435: return SSH_ERR_MESSAGE_INCOMPLETE;
1436: }
1437: need = state->packlen + 4;
1438: if (sshbuf_len(state->input) < need)
1439: return 0; /* packet is incomplete */
1440: sshbuf_reset(state->incoming_packet);
1441: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1442: state->packlen)) != 0 ||
1443: (r = sshbuf_consume(state->input, need)) != 0 ||
1444: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1445: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1446: return r;
1447: if (ssh_packet_log_type(*typep))
1.297 djm 1448: debug3_f("type %u", *typep);
1.242 markus 1449: /* sshbuf_dump(state->incoming_packet, stderr); */
1450: /* reset for next packet */
1451: state->packlen = 0;
1452: return r;
1453: }
1454:
1.201 markus 1455: int
1456: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1457: {
1.201 markus 1458: struct session_state *state = ssh->state;
1.40 markus 1459: u_int padlen, need;
1.231 djm 1460: u_char *cp;
1.201 markus 1461: u_int maclen, aadlen = 0, authlen = 0, block_size;
1462: struct sshenc *enc = NULL;
1463: struct sshmac *mac = NULL;
1464: struct sshcomp *comp = NULL;
1.200 markus 1465: int r;
1.201 markus 1466:
1.242 markus 1467: if (state->mux)
1468: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1469:
1.201 markus 1470: *typep = SSH_MSG_NONE;
1471:
1472: if (state->packet_discard)
1473: return 0;
1474:
1475: if (state->newkeys[MODE_IN] != NULL) {
1476: enc = &state->newkeys[MODE_IN]->enc;
1477: mac = &state->newkeys[MODE_IN]->mac;
1478: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1479: /* disable mac for authenticated encryption */
1480: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1481: mac = NULL;
1.25 markus 1482: }
1483: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1484: block_size = enc ? enc->block_size : 8;
1.180 markus 1485: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1486:
1.201 markus 1487: if (aadlen && state->packlen == 0) {
1.235 djm 1488: if (cipher_get_length(state->receive_context,
1.201 markus 1489: &state->packlen, state->p_read.seqnr,
1490: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1491: return 0;
1492: if (state->packlen < 1 + 4 ||
1493: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1494: #ifdef PACKET_DEBUG
1.201 markus 1495: sshbuf_dump(state->input, stderr);
1.178 markus 1496: #endif
1.201 markus 1497: logit("Bad packet length %u.", state->packlen);
1498: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1499: return r;
1.217 djm 1500: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1501: }
1.201 markus 1502: sshbuf_reset(state->incoming_packet);
1503: } else if (state->packlen == 0) {
1.25 markus 1504: /*
1505: * check if input size is less than the cipher block size,
1506: * decrypt first block and extract length of incoming packet
1507: */
1.201 markus 1508: if (sshbuf_len(state->input) < block_size)
1509: return 0;
1510: sshbuf_reset(state->incoming_packet);
1511: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1512: &cp)) != 0)
1513: goto out;
1.235 djm 1514: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1515: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1516: block_size, 0, 0)) != 0)
1517: goto out;
1518: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1519: if (state->packlen < 1 + 4 ||
1520: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1521: #ifdef PACKET_DEBUG
1.201 markus 1522: fprintf(stderr, "input: \n");
1523: sshbuf_dump(state->input, stderr);
1524: fprintf(stderr, "incoming_packet: \n");
1525: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1526: #endif
1.201 markus 1527: logit("Bad packet length %u.", state->packlen);
1.234 markus 1528: return ssh_packet_start_discard(ssh, enc, mac, 0,
1529: PACKET_MAX_SIZE);
1.25 markus 1530: }
1.201 markus 1531: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1532: goto out;
1.25 markus 1533: }
1.201 markus 1534: DBG(debug("input: packet len %u", state->packlen+4));
1535:
1.178 markus 1536: if (aadlen) {
1537: /* only the payload is encrypted */
1.201 markus 1538: need = state->packlen;
1.178 markus 1539: } else {
1540: /*
1541: * the payload size and the payload are encrypted, but we
1542: * have a partial packet of block_size bytes
1543: */
1.201 markus 1544: need = 4 + state->packlen - block_size;
1.178 markus 1545: }
1.180 markus 1546: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1547: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1548: if (need % block_size != 0) {
1549: logit("padding error: need %d block %d mod %d",
1.25 markus 1550: need, block_size, need % block_size);
1.234 markus 1551: return ssh_packet_start_discard(ssh, enc, mac, 0,
1552: PACKET_MAX_SIZE - block_size);
1.158 markus 1553: }
1.25 markus 1554: /*
1555: * check if the entire packet has been received and
1.178 markus 1556: * decrypt into incoming_packet:
1557: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1558: * 'need' bytes are encrypted, followed by either
1559: * 'authlen' bytes of authentication tag or
1.178 markus 1560: * 'maclen' bytes of message authentication code.
1.25 markus 1561: */
1.201 markus 1562: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1563: return 0; /* packet is incomplete */
1.25 markus 1564: #ifdef PACKET_DEBUG
1565: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1566: sshbuf_dump(state->input, stderr);
1.25 markus 1567: #endif
1.231 djm 1568: /* EtM: check mac over encrypted input */
1.201 markus 1569: if (mac && mac->enabled && mac->etm) {
1.231 djm 1570: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1571: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1572: sshbuf_ptr(state->input) + aadlen + need + authlen,
1573: maclen)) != 0) {
1574: if (r == SSH_ERR_MAC_INVALID)
1575: logit("Corrupted MAC on input.");
1.201 markus 1576: goto out;
1.231 djm 1577: }
1.201 markus 1578: }
1579: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1580: &cp)) != 0)
1581: goto out;
1.235 djm 1582: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1583: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1584: goto out;
1585: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1586: goto out;
1.29 markus 1587: if (mac && mac->enabled) {
1.231 djm 1588: /* Not EtM: check MAC over cleartext */
1589: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1590: sshbuf_ptr(state->incoming_packet),
1591: sshbuf_len(state->incoming_packet),
1592: sshbuf_ptr(state->input), maclen)) != 0) {
1593: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1594: goto out;
1.159 markus 1595: logit("Corrupted MAC on input.");
1.247 markus 1596: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1597: return SSH_ERR_INTERNAL_ERROR;
1598: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1599: sshbuf_len(state->incoming_packet),
1.247 markus 1600: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1601: }
1.231 djm 1602: /* Remove MAC from input buffer */
1.201 markus 1603: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1604: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1605: goto out;
1.25 markus 1606: }
1.77 djm 1607: if (seqnr_p != NULL)
1.201 markus 1608: *seqnr_p = state->p_read.seqnr;
1609: if (++state->p_read.seqnr == 0)
1.106 itojun 1610: logit("incoming seqnr wraps around");
1.201 markus 1611: if (++state->p_read.packets == 0)
1612: if (!(ssh->compat & SSH_BUG_NOREKEY))
1613: return SSH_ERR_NEED_REKEY;
1614: state->p_read.blocks += (state->packlen + 4) / block_size;
1615: state->p_read.bytes += state->packlen + 4;
1.25 markus 1616:
1617: /* get padlen */
1.201 markus 1618: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1619: DBG(debug("input: padlen %d", padlen));
1.205 djm 1620: if (padlen < 4) {
1621: if ((r = sshpkt_disconnect(ssh,
1622: "Corrupted padlen %d on input.", padlen)) != 0 ||
1623: (r = ssh_packet_write_wait(ssh)) != 0)
1624: return r;
1625: return SSH_ERR_CONN_CORRUPT;
1626: }
1.25 markus 1627:
1628: /* skip packet size + padlen, discard padding */
1.201 markus 1629: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1630: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1631: goto out;
1.25 markus 1632:
1.201 markus 1633: DBG(debug("input: len before de-compress %zd",
1634: sshbuf_len(state->incoming_packet)));
1.25 markus 1635: if (comp && comp->enabled) {
1.201 markus 1636: sshbuf_reset(state->compression_buffer);
1637: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1638: state->compression_buffer)) != 0)
1639: goto out;
1640: sshbuf_reset(state->incoming_packet);
1641: if ((r = sshbuf_putb(state->incoming_packet,
1642: state->compression_buffer)) != 0)
1643: goto out;
1644: DBG(debug("input: len after de-compress %zd",
1645: sshbuf_len(state->incoming_packet)));
1.25 markus 1646: }
1647: /*
1648: * get packet type, implies consume.
1649: * return length of payload (without type field)
1650: */
1.201 markus 1651: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1652: goto out;
1.226 djm 1653: if (ssh_packet_log_type(*typep))
1654: debug3("receive packet: type %u", *typep);
1.205 djm 1655: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1656: if ((r = sshpkt_disconnect(ssh,
1657: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1658: (r = ssh_packet_write_wait(ssh)) != 0)
1659: return r;
1660: return SSH_ERR_PROTOCOL_ERROR;
1661: }
1.243 djm 1662: if (state->hook_in != NULL &&
1663: (r = state->hook_in(ssh, state->incoming_packet, typep,
1664: state->hook_in_ctx)) != 0)
1665: return r;
1.238 markus 1666: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1667: r = ssh_packet_enable_delayed_compress(ssh);
1668: else
1669: r = 0;
1.25 markus 1670: #ifdef PACKET_DEBUG
1.201 markus 1671: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1672: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1673: #endif
1.62 markus 1674: /* reset for next packet */
1.201 markus 1675: state->packlen = 0;
1.228 djm 1676:
1677: /* do we need to rekey? */
1678: if (ssh_packet_need_rekeying(ssh, 0)) {
1.297 djm 1679: debug3_f("rekex triggered");
1.228 djm 1680: if ((r = kex_start_rekex(ssh)) != 0)
1681: return r;
1682: }
1.201 markus 1683: out:
1684: return r;
1.25 markus 1685: }
1686:
1687: int
1.201 markus 1688: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1689: {
1.201 markus 1690: struct session_state *state = ssh->state;
1.96 deraadt 1691: u_int reason, seqnr;
1.201 markus 1692: int r;
1693: u_char *msg;
1.62 markus 1694:
1.25 markus 1695: for (;;) {
1.201 markus 1696: msg = NULL;
1.249 djm 1697: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1698: if (r != 0)
1699: return r;
1700: if (*typep) {
1701: state->keep_alive_timeouts = 0;
1702: DBG(debug("received packet type %d", *typep));
1703: }
1704: switch (*typep) {
1705: case SSH2_MSG_IGNORE:
1706: debug3("Received SSH2_MSG_IGNORE");
1707: break;
1708: case SSH2_MSG_DEBUG:
1709: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1710: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1711: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1712: free(msg);
1.201 markus 1713: return r;
1.48 stevesk 1714: }
1.249 djm 1715: debug("Remote: %.900s", msg);
1716: free(msg);
1717: break;
1718: case SSH2_MSG_DISCONNECT:
1719: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1720: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1721: return r;
1722: /* Ignore normal client exit notifications */
1723: do_log2(ssh->state->server_side &&
1724: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1725: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1726: "Received disconnect from %s port %d:"
1727: "%u: %.400s", ssh_remote_ipaddr(ssh),
1728: ssh_remote_port(ssh), reason, msg);
1729: free(msg);
1730: return SSH_ERR_DISCONNECTED;
1731: case SSH2_MSG_UNIMPLEMENTED:
1732: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1733: return r;
1734: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1735: seqnr);
1736: break;
1737: default:
1738: return 0;
1.25 markus 1739: }
1740: }
1741: }
1742:
1.16 markus 1743: /*
1744: * Buffers the given amount of input characters. This is intended to be used
1745: * together with packet_read_poll.
1746: */
1.1 deraadt 1747:
1.204 djm 1748: int
1.201 markus 1749: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1750: {
1.201 markus 1751: struct session_state *state = ssh->state;
1752: int r;
1753:
1754: if (state->packet_discard) {
1755: state->keep_alive_timeouts = 0; /* ?? */
1756: if (len >= state->packet_discard) {
1757: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1758: return r;
1.201 markus 1759: }
1760: state->packet_discard -= len;
1.204 djm 1761: return 0;
1.159 markus 1762: }
1.201 markus 1763: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1764: return r;
1765:
1766: return 0;
1.28 markus 1767: }
1768:
1769: int
1.201 markus 1770: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1771: {
1.201 markus 1772: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1773: }
1774:
1.16 markus 1775: /*
1776: * Sends a diagnostic message from the server to the client. This message
1777: * can be sent at any time (but not while constructing another message). The
1778: * message is printed immediately, but only if the client is being executed
1779: * in verbose mode. These messages are primarily intended to ease debugging
1780: * authentication problems. The length of the formatted message must not
1.205 djm 1781: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1782: */
1.2 provos 1783: void
1.201 markus 1784: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1785: {
1.14 markus 1786: char buf[1024];
1787: va_list args;
1.201 markus 1788: int r;
1.39 markus 1789:
1.249 djm 1790: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1791: return;
1.14 markus 1792:
1793: va_start(args, fmt);
1794: vsnprintf(buf, sizeof(buf), fmt, args);
1795: va_end(args);
1.265 djm 1796:
1797: debug3("sending debug message: %s", buf);
1.14 markus 1798:
1.249 djm 1799: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1800: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1801: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1802: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1803: (r = sshpkt_send(ssh)) != 0 ||
1804: (r = ssh_packet_write_wait(ssh)) != 0)
1.297 djm 1805: fatal_fr(r, "send DEBUG");
1.205 djm 1806: }
1807:
1.268 dtucker 1808: void
1809: sshpkt_fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1.245 djm 1810: {
1811: snprintf(s, l, "%.200s%s%s port %d",
1812: ssh->log_preamble ? ssh->log_preamble : "",
1813: ssh->log_preamble ? " " : "",
1814: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1815: }
1816:
1.205 djm 1817: /*
1818: * Pretty-print connection-terminating errors and exit.
1819: */
1.280 djm 1820: static void
1821: sshpkt_vfatal(struct ssh *ssh, int r, const char *fmt, va_list ap)
1.205 djm 1822: {
1.280 djm 1823: char *tag = NULL, remote_id[512];
1.290 djm 1824: int oerrno = errno;
1.245 djm 1825:
1.268 dtucker 1826: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.245 djm 1827:
1.205 djm 1828: switch (r) {
1829: case SSH_ERR_CONN_CLOSED:
1.257 markus 1830: ssh_packet_clear_keys(ssh);
1.245 djm 1831: logdie("Connection closed by %s", remote_id);
1.205 djm 1832: case SSH_ERR_CONN_TIMEOUT:
1.257 markus 1833: ssh_packet_clear_keys(ssh);
1.245 djm 1834: logdie("Connection %s %s timed out",
1835: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1836: case SSH_ERR_DISCONNECTED:
1.257 markus 1837: ssh_packet_clear_keys(ssh);
1.245 djm 1838: logdie("Disconnected from %s", remote_id);
1.212 djm 1839: case SSH_ERR_SYSTEM_ERROR:
1.257 markus 1840: if (errno == ECONNRESET) {
1841: ssh_packet_clear_keys(ssh);
1.245 djm 1842: logdie("Connection reset by %s", remote_id);
1.257 markus 1843: }
1.213 djm 1844: /* FALLTHROUGH */
1845: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1846: case SSH_ERR_NO_MAC_ALG_MATCH:
1847: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1848: case SSH_ERR_NO_KEX_ALG_MATCH:
1849: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1850: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.257 markus 1851: ssh_packet_clear_keys(ssh);
1.290 djm 1852: errno = oerrno;
1.245 djm 1853: logdie("Unable to negotiate with %s: %s. "
1854: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1855: ssh->kex->failed_choice);
1.212 djm 1856: }
1857: /* FALLTHROUGH */
1.205 djm 1858: default:
1.280 djm 1859: if (vasprintf(&tag, fmt, ap) == -1) {
1860: ssh_packet_clear_keys(ssh);
1.297 djm 1861: logdie_f("could not allocate failure message");
1.280 djm 1862: }
1.257 markus 1863: ssh_packet_clear_keys(ssh);
1.290 djm 1864: errno = oerrno;
1.297 djm 1865: logdie_r(r, "%s%sConnection %s %s",
1.205 djm 1866: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.297 djm 1867: ssh->state->server_side ? "from" : "to", remote_id);
1.205 djm 1868: }
1.1 deraadt 1869: }
1870:
1.280 djm 1871: void
1872: sshpkt_fatal(struct ssh *ssh, int r, const char *fmt, ...)
1873: {
1874: va_list ap;
1875:
1876: va_start(ap, fmt);
1877: sshpkt_vfatal(ssh, r, fmt, ap);
1878: /* NOTREACHED */
1879: va_end(ap);
1.297 djm 1880: logdie_f("should have exited");
1.280 djm 1881: }
1882:
1.16 markus 1883: /*
1884: * Logs the error plus constructs and sends a disconnect packet, closes the
1885: * connection, and exits. This function never returns. The error message
1886: * should not contain a newline. The length of the formatted message must
1887: * not exceed 1024 bytes.
1888: */
1.2 provos 1889: void
1.201 markus 1890: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1891: {
1.245 djm 1892: char buf[1024], remote_id[512];
1.14 markus 1893: va_list args;
1894: static int disconnecting = 0;
1.201 markus 1895: int r;
1.97 deraadt 1896:
1.14 markus 1897: if (disconnecting) /* Guard against recursive invocations. */
1898: fatal("packet_disconnect called recursively.");
1899: disconnecting = 1;
1900:
1.16 markus 1901: /*
1902: * Format the message. Note that the caller must make sure the
1903: * message is of limited size.
1904: */
1.268 dtucker 1905: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1906: va_start(args, fmt);
1907: vsnprintf(buf, sizeof(buf), fmt, args);
1908: va_end(args);
1909:
1.99 markus 1910: /* Display the error locally */
1.245 djm 1911: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1912:
1.205 djm 1913: /*
1914: * Send the disconnect message to the other side, and wait
1915: * for it to get sent.
1916: */
1917: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1.280 djm 1918: sshpkt_fatal(ssh, r, "%s", __func__);
1.205 djm 1919:
1920: if ((r = ssh_packet_write_wait(ssh)) != 0)
1.280 djm 1921: sshpkt_fatal(ssh, r, "%s", __func__);
1.14 markus 1922:
1923: /* Close the connection. */
1.201 markus 1924: ssh_packet_close(ssh);
1.112 markus 1925: cleanup_exit(255);
1.1 deraadt 1926: }
1927:
1.205 djm 1928: /*
1929: * Checks if there is any buffered output, and tries to write some of
1930: * the output.
1931: */
1932: int
1.201 markus 1933: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1934: {
1.201 markus 1935: struct session_state *state = ssh->state;
1936: int len = sshbuf_len(state->output);
1.222 markus 1937: int r;
1.97 deraadt 1938:
1.14 markus 1939: if (len > 0) {
1.222 markus 1940: len = write(state->connection_out,
1941: sshbuf_ptr(state->output), len);
1.156 djm 1942: if (len == -1) {
1943: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1944: return 0;
1945: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1946: }
1.222 markus 1947: if (len == 0)
1.205 djm 1948: return SSH_ERR_CONN_CLOSED;
1.201 markus 1949: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1950: return r;
1.14 markus 1951: }
1.205 djm 1952: return 0;
1.1 deraadt 1953: }
1954:
1.16 markus 1955: /*
1956: * Calls packet_write_poll repeatedly until all pending output data has been
1957: * written.
1958: */
1.205 djm 1959: int
1.201 markus 1960: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1961: {
1.56 millert 1962: fd_set *setp;
1.205 djm 1963: int ret, r, ms_remain = 0;
1.154 dtucker 1964: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1965: struct session_state *state = ssh->state;
1.56 millert 1966:
1.214 deraadt 1967: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1968: NFDBITS), sizeof(fd_mask));
1.201 markus 1969: if (setp == NULL)
1.205 djm 1970: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1971: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1972: free(setp);
1.215 djm 1973: return r;
1.216 gsoares 1974: }
1.201 markus 1975: while (ssh_packet_have_data_to_write(ssh)) {
1976: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1977: NFDBITS) * sizeof(fd_mask));
1.201 markus 1978: FD_SET(state->connection_out, setp);
1.154 dtucker 1979:
1.201 markus 1980: if (state->packet_timeout_ms > 0) {
1981: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1982: timeoutp = &timeout;
1983: }
1984: for (;;) {
1.291 markus 1985: if (state->packet_timeout_ms > 0) {
1.154 dtucker 1986: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1987: monotime_tv(&start);
1.154 dtucker 1988: }
1.201 markus 1989: if ((ret = select(state->connection_out + 1,
1.161 andreas 1990: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1991: break;
1.161 andreas 1992: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1993: break;
1.291 markus 1994: if (state->packet_timeout_ms <= 0)
1.154 dtucker 1995: continue;
1996: ms_subtract_diff(&start, &ms_remain);
1997: if (ms_remain <= 0) {
1998: ret = 0;
1999: break;
2000: }
2001: }
2002: if (ret == 0) {
1.205 djm 2003: free(setp);
2004: return SSH_ERR_CONN_TIMEOUT;
2005: }
2006: if ((r = ssh_packet_write_poll(ssh)) != 0) {
2007: free(setp);
2008: return r;
1.154 dtucker 2009: }
1.14 markus 2010: }
1.186 djm 2011: free(setp);
1.205 djm 2012: return 0;
1.1 deraadt 2013: }
2014:
2015: /* Returns true if there is buffered data to write to the connection. */
2016:
1.2 provos 2017: int
1.201 markus 2018: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 2019: {
1.201 markus 2020: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 2021: }
2022:
2023: /* Returns true if there is not too much data to write to the connection. */
2024:
1.2 provos 2025: int
1.201 markus 2026: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 2027: {
1.201 markus 2028: if (ssh->state->interactive_mode)
2029: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 2030: else
1.201 markus 2031: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 2032: }
2033:
1.201 markus 2034: void
2035: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 2036: {
1.263 djm 2037: if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
1.101 markus 2038: return;
1.298 djm 2039: set_sock_tos(ssh->state->connection_in, tos);
1.101 markus 2040: }
2041:
1.1 deraadt 2042: /* Informs that the current session is interactive. Sets IP flags for that. */
2043:
1.2 provos 2044: void
1.201 markus 2045: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2046: {
1.201 markus 2047: struct session_state *state = ssh->state;
2048:
2049: if (state->set_interactive_called)
1.43 markus 2050: return;
1.201 markus 2051: state->set_interactive_called = 1;
1.1 deraadt 2052:
1.14 markus 2053: /* Record that we are in interactive mode. */
1.201 markus 2054: state->interactive_mode = interactive;
1.1 deraadt 2055:
1.19 markus 2056: /* Only set socket options if using a socket. */
1.201 markus 2057: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2058: return;
1.201 markus 2059: set_nodelay(state->connection_in);
1.298 djm 2060: ssh_packet_set_tos(ssh, interactive ? qos_interactive : qos_bulk);
1.1 deraadt 2061: }
2062:
2063: /* Returns true if the current connection is interactive. */
2064:
1.2 provos 2065: int
1.201 markus 2066: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2067: {
1.201 markus 2068: return ssh->state->interactive_mode;
1.12 markus 2069: }
2070:
1.113 deraadt 2071: int
1.201 markus 2072: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2073: {
1.201 markus 2074: struct session_state *state = ssh->state;
2075:
2076: if (state->set_maxsize_called) {
1.106 itojun 2077: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2078: state->max_packet_size, s);
1.14 markus 2079: return -1;
2080: }
2081: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2082: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2083: return -1;
2084: }
1.201 markus 2085: state->set_maxsize_called = 1;
1.66 markus 2086: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2087: state->max_packet_size = s;
1.14 markus 2088: return s;
1.53 markus 2089: }
2090:
1.161 andreas 2091: int
1.201 markus 2092: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2093: {
1.201 markus 2094: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2095: }
2096:
2097: void
1.201 markus 2098: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2099: {
1.201 markus 2100: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2101: }
2102:
2103: u_int
1.201 markus 2104: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2105: {
1.201 markus 2106: return ssh->state->max_packet_size;
1.71 markus 2107: }
2108:
1.105 markus 2109: void
1.244 dtucker 2110: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2111: {
1.244 dtucker 2112: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2113: (unsigned int)seconds);
1.201 markus 2114: ssh->state->rekey_limit = bytes;
2115: ssh->state->rekey_interval = seconds;
1.184 dtucker 2116: }
2117:
2118: time_t
1.201 markus 2119: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2120: {
2121: time_t seconds;
2122:
1.201 markus 2123: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2124: monotime();
1.185 dtucker 2125: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2126: }
2127:
2128: void
1.201 markus 2129: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2130: {
1.201 markus 2131: ssh->state->server_side = 1;
1.278 djm 2132: ssh->kex->server = 1; /* XXX unify? */
1.118 markus 2133: }
2134:
2135: void
1.201 markus 2136: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2137: {
1.201 markus 2138: ssh->state->after_authentication = 1;
1.161 andreas 2139: }
2140:
2141: void *
1.201 markus 2142: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2143: {
1.201 markus 2144: return (void *)ssh->state->input;
1.161 andreas 2145: }
2146:
2147: void *
1.201 markus 2148: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2149: {
1.201 markus 2150: return (void *)ssh->state->output;
1.166 andreas 2151: }
2152:
1.196 markus 2153: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2154: static int
2155: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2156: {
1.239 djm 2157: int r;
1.196 markus 2158:
1.297 djm 2159: debug_f("called");
1.196 markus 2160: /* This was set in net child, but is not visible in user child */
1.201 markus 2161: ssh->state->after_authentication = 1;
2162: ssh->state->rekeying = 0;
1.239 djm 2163: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2164: return r;
1.201 markus 2165: return 0;
2166: }
2167:
2168: /* Packet state (de-)serialization for privsep */
2169:
2170: /* turn kex into a blob for packet state serialization */
2171: static int
2172: kex_to_blob(struct sshbuf *m, struct kex *kex)
2173: {
2174: int r;
2175:
1.299 ! djm 2176: if ((r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
1.269 djm 2177: (r = sshbuf_put_cstring(m, kex->hostkey_alg)) != 0 ||
1.201 markus 2178: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
1.269 djm 2179: (r = sshbuf_put_u32(m, kex->hostkey_nid)) != 0 ||
1.201 markus 2180: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2181: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2182: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
1.278 djm 2183: (r = sshbuf_put_stringb(m, kex->client_version)) != 0 ||
2184: (r = sshbuf_put_stringb(m, kex->server_version)) != 0 ||
1.299 ! djm 2185: (r = sshbuf_put_stringb(m, kex->session_id)) != 0 ||
1.278 djm 2186: (r = sshbuf_put_u32(m, kex->flags)) != 0)
1.201 markus 2187: return r;
2188: return 0;
2189: }
2190:
2191: /* turn key exchange results into a blob for packet state serialization */
2192: static int
2193: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2194: {
2195: struct sshbuf *b;
2196: struct sshcipher_ctx *cc;
2197: struct sshcomp *comp;
2198: struct sshenc *enc;
2199: struct sshmac *mac;
2200: struct newkeys *newkey;
2201: int r;
2202:
2203: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2204: return SSH_ERR_INTERNAL_ERROR;
2205: enc = &newkey->enc;
2206: mac = &newkey->mac;
2207: comp = &newkey->comp;
1.235 djm 2208: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2209: ssh->state->receive_context;
1.201 markus 2210: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2211: return r;
2212: if ((b = sshbuf_new()) == NULL)
2213: return SSH_ERR_ALLOC_FAIL;
2214: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2215: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2216: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2217: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2218: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2219: goto out;
2220: if (cipher_authlen(enc->cipher) == 0) {
2221: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2222: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2223: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2224: goto out;
2225: }
2226: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2227: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2228: goto out;
2229: r = sshbuf_put_stringb(m, b);
2230: out:
1.221 mmcc 2231: sshbuf_free(b);
1.201 markus 2232: return r;
2233: }
2234:
2235: /* serialize packet state into a blob */
2236: int
2237: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2238: {
2239: struct session_state *state = ssh->state;
1.249 djm 2240: int r;
1.201 markus 2241:
1.249 djm 2242: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2243: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2244: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2245: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2246: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2247: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2248: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2249: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2250: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2251: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2252: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2253: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2254: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2255: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2256: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 2257: return r;
1.201 markus 2258:
2259: return 0;
2260: }
2261:
2262: /* restore key exchange results from blob for packet state de-serialization */
2263: static int
2264: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2265: {
2266: struct sshbuf *b = NULL;
2267: struct sshcomp *comp;
2268: struct sshenc *enc;
2269: struct sshmac *mac;
2270: struct newkeys *newkey = NULL;
2271: size_t keylen, ivlen, maclen;
2272: int r;
2273:
2274: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2275: r = SSH_ERR_ALLOC_FAIL;
2276: goto out;
2277: }
2278: if ((r = sshbuf_froms(m, &b)) != 0)
2279: goto out;
2280: #ifdef DEBUG_PK
2281: sshbuf_dump(b, stderr);
2282: #endif
2283: enc = &newkey->enc;
2284: mac = &newkey->mac;
2285: comp = &newkey->comp;
2286:
2287: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2288: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2289: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2290: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2291: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2292: goto out;
1.262 djm 2293: if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2294: r = SSH_ERR_INVALID_FORMAT;
2295: goto out;
2296: }
1.201 markus 2297: if (cipher_authlen(enc->cipher) == 0) {
2298: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2299: goto out;
2300: if ((r = mac_setup(mac, mac->name)) != 0)
2301: goto out;
2302: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2303: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2304: goto out;
2305: if (maclen > mac->key_len) {
2306: r = SSH_ERR_INVALID_FORMAT;
2307: goto out;
2308: }
2309: mac->key_len = maclen;
2310: }
2311: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2312: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2313: goto out;
2314: if (sshbuf_len(b) != 0) {
2315: r = SSH_ERR_INVALID_FORMAT;
2316: goto out;
2317: }
2318: enc->key_len = keylen;
2319: enc->iv_len = ivlen;
2320: ssh->kex->newkeys[mode] = newkey;
2321: newkey = NULL;
2322: r = 0;
2323: out:
1.219 mmcc 2324: free(newkey);
1.221 mmcc 2325: sshbuf_free(b);
1.201 markus 2326: return r;
2327: }
2328:
2329: /* restore kex from blob for packet state de-serialization */
2330: static int
2331: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2332: {
2333: struct kex *kex;
2334: int r;
2335:
1.278 djm 2336: if ((kex = kex_new()) == NULL)
2337: return SSH_ERR_ALLOC_FAIL;
1.299 ! djm 2338: if ((r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
1.269 djm 2339: (r = sshbuf_get_cstring(m, &kex->hostkey_alg, NULL)) != 0 ||
1.201 markus 2340: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
1.269 djm 2341: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_nid)) != 0 ||
1.201 markus 2342: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2343: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2344: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
1.278 djm 2345: (r = sshbuf_get_stringb(m, kex->client_version)) != 0 ||
2346: (r = sshbuf_get_stringb(m, kex->server_version)) != 0 ||
1.299 ! djm 2347: (r = sshbuf_get_stringb(m, kex->session_id)) != 0 ||
1.278 djm 2348: (r = sshbuf_get_u32(m, &kex->flags)) != 0)
1.201 markus 2349: goto out;
2350: kex->server = 1;
2351: kex->done = 1;
2352: r = 0;
2353: out:
2354: if (r != 0 || kexp == NULL) {
1.278 djm 2355: kex_free(kex);
1.201 markus 2356: if (kexp != NULL)
2357: *kexp = NULL;
2358: } else {
1.278 djm 2359: kex_free(*kexp);
1.201 markus 2360: *kexp = kex;
2361: }
2362: return r;
2363: }
2364:
2365: /*
2366: * Restore packet state from content of blob 'm' (de-serialization).
2367: * Note that 'm' will be partially consumed on parsing or any other errors.
2368: */
2369: int
2370: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2371: {
2372: struct session_state *state = ssh->state;
1.254 djm 2373: const u_char *input, *output;
2374: size_t ilen, olen;
1.201 markus 2375: int r;
2376:
1.249 djm 2377: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2378: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2379: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2380: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2381: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2382: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2383: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2384: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2385: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2386: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2387: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2388: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2389: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2390: return r;
2391: /*
1.296 djm 2392: * We set the time here so that in post-auth privsep child we
1.249 djm 2393: * count from the completion of the authentication.
2394: */
2395: state->rekey_time = monotime();
2396: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2397: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2398: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2399: return r;
1.201 markus 2400:
1.239 djm 2401: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2402: return r;
2403:
2404: sshbuf_reset(state->input);
2405: sshbuf_reset(state->output);
2406: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2407: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2408: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2409: (r = sshbuf_put(state->output, output, olen)) != 0)
2410: return r;
2411:
2412: if (sshbuf_len(m))
2413: return SSH_ERR_INVALID_FORMAT;
1.297 djm 2414: debug3_f("done");
1.201 markus 2415: return 0;
2416: }
2417:
2418: /* NEW API */
2419:
2420: /* put data to the outgoing packet */
2421:
2422: int
2423: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2424: {
2425: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2426: }
2427:
2428: int
2429: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2430: {
2431: return sshbuf_putb(ssh->state->outgoing_packet, b);
2432: }
2433:
2434: int
2435: sshpkt_put_u8(struct ssh *ssh, u_char val)
2436: {
2437: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2438: }
2439:
2440: int
2441: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2442: {
2443: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2444: }
2445:
2446: int
2447: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2448: {
2449: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2450: }
2451:
2452: int
2453: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2454: {
2455: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2456: }
2457:
2458: int
2459: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2460: {
2461: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2462: }
2463:
2464: int
2465: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2466: {
2467: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2468: }
2469:
1.211 djm 2470: #ifdef WITH_OPENSSL
1.201 markus 2471: int
2472: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2473: {
2474: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2475: }
2476:
2477:
2478: int
2479: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2480: {
2481: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2482: }
1.211 djm 2483: #endif /* WITH_OPENSSL */
1.201 markus 2484:
2485: /* fetch data from the incoming packet */
2486:
2487: int
2488: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2489: {
2490: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2491: }
2492:
2493: int
2494: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2495: {
2496: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2497: }
2498:
2499: int
2500: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2501: {
2502: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2503: }
2504:
2505: int
2506: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2507: {
2508: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2509: }
2510:
2511: int
2512: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2513: {
2514: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2515: }
2516:
2517: int
2518: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2519: {
2520: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2521: }
2522:
2523: int
1.264 djm 2524: sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2525: {
2526: return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2527: }
2528:
2529: int
1.201 markus 2530: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2531: {
2532: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
1.282 djm 2533: }
2534:
2535: int
2536: sshpkt_getb_froms(struct ssh *ssh, struct sshbuf **valp)
2537: {
2538: return sshbuf_froms(ssh->state->incoming_packet, valp);
1.201 markus 2539: }
2540:
1.211 djm 2541: #ifdef WITH_OPENSSL
1.201 markus 2542: int
2543: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2544: {
2545: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2546: }
2547:
2548: int
1.281 djm 2549: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM **valp)
1.201 markus 2550: {
1.281 djm 2551: return sshbuf_get_bignum2(ssh->state->incoming_packet, valp);
1.201 markus 2552: }
1.211 djm 2553: #endif /* WITH_OPENSSL */
1.201 markus 2554:
2555: int
2556: sshpkt_get_end(struct ssh *ssh)
2557: {
2558: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2559: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2560: return 0;
2561: }
2562:
2563: const u_char *
2564: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2565: {
2566: if (lenp != NULL)
2567: *lenp = sshbuf_len(ssh->state->incoming_packet);
2568: return sshbuf_ptr(ssh->state->incoming_packet);
2569: }
2570:
2571: /* start a new packet */
2572:
2573: int
2574: sshpkt_start(struct ssh *ssh, u_char type)
2575: {
1.249 djm 2576: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2577:
2578: DBG(debug("packet_start[%d]", type));
1.249 djm 2579: memset(buf, 0, sizeof(buf));
2580: buf[sizeof(buf) - 1] = type;
1.201 markus 2581: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2582: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2583: }
2584:
1.242 markus 2585: static int
2586: ssh_packet_send_mux(struct ssh *ssh)
2587: {
2588: struct session_state *state = ssh->state;
2589: u_char type, *cp;
2590: size_t len;
2591: int r;
2592:
2593: if (ssh->kex)
2594: return SSH_ERR_INTERNAL_ERROR;
2595: len = sshbuf_len(state->outgoing_packet);
2596: if (len < 6)
2597: return SSH_ERR_INTERNAL_ERROR;
2598: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2599: type = cp[5];
2600: if (ssh_packet_log_type(type))
1.297 djm 2601: debug3_f("type %u", type);
1.242 markus 2602: /* drop everything, but the connection protocol */
2603: if (type >= SSH2_MSG_CONNECTION_MIN &&
2604: type <= SSH2_MSG_CONNECTION_MAX) {
2605: POKE_U32(cp, len - 4);
2606: if ((r = sshbuf_putb(state->output,
2607: state->outgoing_packet)) != 0)
2608: return r;
2609: /* sshbuf_dump(state->output, stderr); */
2610: }
2611: sshbuf_reset(state->outgoing_packet);
1.264 djm 2612: return 0;
2613: }
2614:
2615: /*
2616: * 9.2. Ignored Data Message
2617: *
2618: * byte SSH_MSG_IGNORE
2619: * string data
2620: *
2621: * All implementations MUST understand (and ignore) this message at any
2622: * time (after receiving the protocol version). No implementation is
2623: * required to send them. This message can be used as an additional
2624: * protection measure against advanced traffic analysis techniques.
2625: */
2626: int
2627: sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2628: {
2629: u_int32_t rnd = 0;
2630: int r;
2631: u_int i;
2632:
2633: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2634: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2635: return r;
2636: for (i = 0; i < nbytes; i++) {
2637: if (i % 4 == 0)
2638: rnd = arc4random();
2639: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2640: return r;
2641: rnd >>= 8;
2642: }
1.242 markus 2643: return 0;
2644: }
2645:
1.201 markus 2646: /* send it */
2647:
2648: int
2649: sshpkt_send(struct ssh *ssh)
2650: {
1.242 markus 2651: if (ssh->state && ssh->state->mux)
2652: return ssh_packet_send_mux(ssh);
1.249 djm 2653: return ssh_packet_send2(ssh);
1.201 markus 2654: }
2655:
2656: int
2657: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2658: {
2659: char buf[1024];
2660: va_list args;
2661: int r;
2662:
2663: va_start(args, fmt);
2664: vsnprintf(buf, sizeof(buf), fmt, args);
2665: va_end(args);
2666:
1.249 djm 2667: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2668: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2669: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2670: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2671: (r = sshpkt_send(ssh)) != 0)
2672: return r;
1.201 markus 2673: return 0;
2674: }
2675:
2676: /* roundup current message to pad bytes */
2677: int
2678: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2679: {
2680: ssh->state->extra_pad = pad;
2681: return 0;
1.1 deraadt 2682: }
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