Annotation of src/usr.bin/ssh/packet.c, Revision 1.311
1.311 ! djm 1: /* $OpenBSD: packet.c,v 1.310 2023/04/06 03:21:31 djm Exp $ */
1.1 deraadt 2: /*
1.15 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.35 deraadt 6: * This file contains code implementing the packet protocol and communication
7: * with the other side. This same code is used both on client and server side.
1.29 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
1.29 markus 14: *
1.25 markus 15: *
16: * SSH2 packet format added by Markus Friedl.
1.69 markus 17: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.25 markus 18: *
1.35 deraadt 19: * Redistribution and use in source and binary forms, with or without
20: * modification, are permitted provided that the following conditions
21: * are met:
22: * 1. Redistributions of source code must retain the above copyright
23: * notice, this list of conditions and the following disclaimer.
24: * 2. Redistributions in binary form must reproduce the above copyright
25: * notice, this list of conditions and the following disclaimer in the
26: * documentation and/or other materials provided with the distribution.
27: *
28: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15 deraadt 38: */
1.1 deraadt 39:
1.142 deraadt 40: #include <sys/types.h>
1.105 markus 41: #include <sys/queue.h>
1.132 stevesk 42: #include <sys/socket.h>
1.138 stevesk 43: #include <sys/time.h>
1.132 stevesk 44: #include <netinet/in.h>
1.121 stevesk 45: #include <netinet/ip.h>
1.134 stevesk 46:
1.135 stevesk 47: #include <errno.h>
1.230 djm 48: #include <netdb.h>
1.134 stevesk 49: #include <stdarg.h>
1.141 stevesk 50: #include <stdio.h>
1.140 stevesk 51: #include <stdlib.h>
1.137 stevesk 52: #include <string.h>
1.136 stevesk 53: #include <unistd.h>
1.203 deraadt 54: #include <limits.h>
1.278 djm 55: #include <poll.h>
1.142 deraadt 56: #include <signal.h>
1.184 dtucker 57: #include <time.h>
1.1 deraadt 58:
1.288 dtucker 59: #ifdef WITH_ZLIB
1.201 markus 60: #include <zlib.h>
1.288 dtucker 61: #endif
1.201 markus 62:
1.1 deraadt 63: #include "xmalloc.h"
1.25 markus 64: #include "compat.h"
65: #include "ssh2.h"
1.37 markus 66: #include "cipher.h"
1.201 markus 67: #include "sshkey.h"
1.25 markus 68: #include "kex.h"
1.200 markus 69: #include "digest.h"
1.50 markus 70: #include "mac.h"
1.46 markus 71: #include "log.h"
72: #include "canohost.h"
1.87 stevesk 73: #include "misc.h"
1.198 millert 74: #include "channels.h"
1.95 markus 75: #include "ssh.h"
1.201 markus 76: #include "packet.h"
1.197 djm 77: #include "ssherr.h"
1.201 markus 78: #include "sshbuf.h"
1.25 markus 79:
80: #ifdef PACKET_DEBUG
81: #define DBG(x) x
82: #else
83: #define DBG(x)
84: #endif
85:
1.159 markus 86: #define PACKET_MAX_SIZE (256 * 1024)
87:
1.161 andreas 88: struct packet_state {
89: u_int32_t seqnr;
90: u_int32_t packets;
91: u_int64_t blocks;
92: u_int64_t bytes;
93: };
94:
95: struct packet {
96: TAILQ_ENTRY(packet) next;
97: u_char type;
1.201 markus 98: struct sshbuf *payload;
1.161 andreas 99: };
100:
101: struct session_state {
102: /*
103: * This variable contains the file descriptors used for
104: * communicating with the other side. connection_in is used for
105: * reading; connection_out for writing. These can be the same
106: * descriptor, in which case it is assumed to be a socket.
107: */
108: int connection_in;
109: int connection_out;
110:
111: /* Protocol flags for the remote side. */
112: u_int remote_protocol_flags;
1.1 deraadt 113:
1.161 andreas 114: /* Encryption context for receiving data. Only used for decryption. */
1.235 djm 115: struct sshcipher_ctx *receive_context;
1.1 deraadt 116:
1.161 andreas 117: /* Encryption context for sending data. Only used for encryption. */
1.235 djm 118: struct sshcipher_ctx *send_context;
1.14 markus 119:
1.161 andreas 120: /* Buffer for raw input data from the socket. */
1.201 markus 121: struct sshbuf *input;
1.1 deraadt 122:
1.161 andreas 123: /* Buffer for raw output data going to the socket. */
1.201 markus 124: struct sshbuf *output;
1.1 deraadt 125:
1.161 andreas 126: /* Buffer for the partial outgoing packet being constructed. */
1.201 markus 127: struct sshbuf *outgoing_packet;
1.1 deraadt 128:
1.161 andreas 129: /* Buffer for the incoming packet currently being processed. */
1.201 markus 130: struct sshbuf *incoming_packet;
1.1 deraadt 131:
1.161 andreas 132: /* Scratch buffer for packet compression/decompression. */
1.201 markus 133: struct sshbuf *compression_buffer;
134:
1.288 dtucker 135: #ifdef WITH_ZLIB
1.201 markus 136: /* Incoming/outgoing compression dictionaries */
137: z_stream compression_in_stream;
138: z_stream compression_out_stream;
1.288 dtucker 139: #endif
1.201 markus 140: int compression_in_started;
141: int compression_out_started;
142: int compression_in_failures;
143: int compression_out_failures;
1.1 deraadt 144:
1.161 andreas 145: /* default maximum packet size */
146: u_int max_packet_size;
1.1 deraadt 147:
1.161 andreas 148: /* Flag indicating whether this module has been initialized. */
149: int initialized;
1.12 markus 150:
1.161 andreas 151: /* Set to true if the connection is interactive. */
152: int interactive_mode;
1.1 deraadt 153:
1.161 andreas 154: /* Set to true if we are the server side. */
155: int server_side;
1.1 deraadt 156:
1.161 andreas 157: /* Set to true if we are authenticated. */
158: int after_authentication;
1.118 markus 159:
1.161 andreas 160: int keep_alive_timeouts;
1.118 markus 161:
1.161 andreas 162: /* The maximum time that we will wait to send or receive a packet */
163: int packet_timeout_ms;
1.151 dtucker 164:
1.161 andreas 165: /* Session key information for Encryption and MAC */
1.201 markus 166: struct newkeys *newkeys[MODE_MAX];
1.161 andreas 167: struct packet_state p_read, p_send;
1.154 dtucker 168:
1.184 dtucker 169: /* Volume-based rekeying */
1.224 dtucker 170: u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
1.105 markus 171:
1.184 dtucker 172: /* Time-based rekeying */
1.208 markus 173: u_int32_t rekey_interval; /* how often in seconds */
1.184 dtucker 174: time_t rekey_time; /* time of last rekeying */
175:
1.161 andreas 176: /* roundup current message to extra_pad bytes */
177: u_char extra_pad;
1.95 markus 178:
1.161 andreas 179: /* XXX discard incoming data after MAC error */
180: u_int packet_discard;
1.234 markus 181: size_t packet_discard_mac_already;
1.201 markus 182: struct sshmac *packet_discard_mac;
1.71 markus 183:
1.161 andreas 184: /* Used in packet_read_poll2() */
185: u_int packlen;
1.159 markus 186:
1.165 andreas 187: /* Used in packet_send2 */
188: int rekeying;
189:
1.242 markus 190: /* Used in ssh_packet_send_mux() */
191: int mux;
192:
1.165 andreas 193: /* Used in packet_set_interactive */
194: int set_interactive_called;
195:
196: /* Used in packet_set_maxsize */
197: int set_maxsize_called;
198:
1.201 markus 199: /* One-off warning about weak ciphers */
200: int cipher_warning_done;
201:
1.243 djm 202: /* Hook for fuzzing inbound packets */
203: ssh_packet_hook_fn *hook_in;
204: void *hook_in_ctx;
205:
1.161 andreas 206: TAILQ_HEAD(, packet) outgoing;
1.105 markus 207: };
1.161 andreas 208:
1.201 markus 209: struct ssh *
210: ssh_alloc_session_state(void)
1.161 andreas 211: {
1.201 markus 212: struct ssh *ssh = NULL;
213: struct session_state *state = NULL;
1.161 andreas 214:
1.201 markus 215: if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
216: (state = calloc(1, sizeof(*state))) == NULL ||
1.278 djm 217: (ssh->kex = kex_new()) == NULL ||
1.201 markus 218: (state->input = sshbuf_new()) == NULL ||
219: (state->output = sshbuf_new()) == NULL ||
220: (state->outgoing_packet = sshbuf_new()) == NULL ||
221: (state->incoming_packet = sshbuf_new()) == NULL)
222: goto fail;
223: TAILQ_INIT(&state->outgoing);
1.202 markus 224: TAILQ_INIT(&ssh->private_keys);
225: TAILQ_INIT(&ssh->public_keys);
1.201 markus 226: state->connection_in = -1;
227: state->connection_out = -1;
228: state->max_packet_size = 32768;
229: state->packet_timeout_ms = -1;
230: state->p_send.packets = state->p_read.packets = 0;
231: state->initialized = 1;
232: /*
233: * ssh_packet_send2() needs to queue packets until
234: * we've done the initial key exchange.
235: */
236: state->rekeying = 1;
237: ssh->state = state;
238: return ssh;
239: fail:
1.278 djm 240: if (ssh) {
241: kex_free(ssh->kex);
242: free(ssh);
243: }
1.201 markus 244: if (state) {
245: sshbuf_free(state->input);
246: sshbuf_free(state->output);
247: sshbuf_free(state->incoming_packet);
248: sshbuf_free(state->outgoing_packet);
249: free(state);
250: }
251: return NULL;
1.161 andreas 252: }
1.105 markus 253:
1.243 djm 254: void
255: ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
256: {
257: ssh->state->hook_in = hook;
258: ssh->state->hook_in_ctx = ctx;
259: }
260:
1.228 djm 261: /* Returns nonzero if rekeying is in progress */
262: int
263: ssh_packet_is_rekeying(struct ssh *ssh)
264: {
1.292 markus 265: return ssh->state->rekeying ||
266: (ssh->kex != NULL && ssh->kex->done == 0);
1.228 djm 267: }
268:
1.16 markus 269: /*
1.253 naddy 270: * Sets the descriptors used for communication.
1.16 markus 271: */
1.201 markus 272: struct ssh *
273: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1 deraadt 274: {
1.201 markus 275: struct session_state *state;
276: const struct sshcipher *none = cipher_by_name("none");
1.197 djm 277: int r;
1.97 deraadt 278:
1.205 djm 279: if (none == NULL) {
1.297 djm 280: error_f("cannot load cipher 'none'");
1.205 djm 281: return NULL;
282: }
1.201 markus 283: if (ssh == NULL)
284: ssh = ssh_alloc_session_state();
1.205 djm 285: if (ssh == NULL) {
1.297 djm 286: error_f("could not allocate state");
1.205 djm 287: return NULL;
288: }
1.201 markus 289: state = ssh->state;
290: state->connection_in = fd_in;
291: state->connection_out = fd_out;
292: if ((r = cipher_init(&state->send_context, none,
1.197 djm 293: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201 markus 294: (r = cipher_init(&state->receive_context, none,
1.205 djm 295: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
1.297 djm 296: error_fr(r, "cipher_init failed");
1.230 djm 297: free(ssh); /* XXX need ssh_free_session_state? */
1.205 djm 298: return NULL;
299: }
1.201 markus 300: state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
1.207 djm 301: /*
302: * Cache the IP address of the remote connection for use in error
303: * messages that might be generated after the connection has closed.
304: */
305: (void)ssh_remote_ipaddr(ssh);
1.201 markus 306: return ssh;
1.1 deraadt 307: }
308:
1.154 dtucker 309: void
1.201 markus 310: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 311: {
1.201 markus 312: struct session_state *state = ssh->state;
313:
1.174 djm 314: if (timeout <= 0 || count <= 0) {
1.201 markus 315: state->packet_timeout_ms = -1;
1.154 dtucker 316: return;
317: }
318: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 319: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 320: else
1.201 markus 321: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 322: }
323:
1.242 markus 324: void
325: ssh_packet_set_mux(struct ssh *ssh)
326: {
327: ssh->state->mux = 1;
328: ssh->state->rekeying = 0;
1.292 markus 329: kex_free(ssh->kex);
330: ssh->kex = NULL;
1.242 markus 331: }
332:
333: int
334: ssh_packet_get_mux(struct ssh *ssh)
335: {
336: return ssh->state->mux;
337: }
338:
1.201 markus 339: int
1.245 djm 340: ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
341: {
342: va_list args;
343: int r;
344:
345: free(ssh->log_preamble);
346: if (fmt == NULL)
347: ssh->log_preamble = NULL;
348: else {
349: va_start(args, fmt);
350: r = vasprintf(&ssh->log_preamble, fmt, args);
351: va_end(args);
352: if (r < 0 || ssh->log_preamble == NULL)
353: return SSH_ERR_ALLOC_FAIL;
354: }
355: return 0;
356: }
357:
358: int
1.201 markus 359: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 360: {
1.201 markus 361: struct session_state *state = ssh->state;
362: int r;
363:
364: if (state->packet_discard_mac) {
1.159 markus 365: char buf[1024];
1.234 markus 366: size_t dlen = PACKET_MAX_SIZE;
1.201 markus 367:
1.234 markus 368: if (dlen > state->packet_discard_mac_already)
369: dlen -= state->packet_discard_mac_already;
1.159 markus 370: memset(buf, 'a', sizeof(buf));
1.234 markus 371: while (sshbuf_len(state->incoming_packet) < dlen)
1.201 markus 372: if ((r = sshbuf_put(state->incoming_packet, buf,
373: sizeof(buf))) != 0)
374: return r;
375: (void) mac_compute(state->packet_discard_mac,
376: state->p_read.seqnr,
1.234 markus 377: sshbuf_ptr(state->incoming_packet), dlen,
1.201 markus 378: NULL, 0);
1.159 markus 379: }
1.220 djm 380: logit("Finished discarding for %.200s port %d",
381: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 382: return SSH_ERR_MAC_INVALID;
1.159 markus 383: }
384:
1.201 markus 385: static int
386: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
1.234 markus 387: struct sshmac *mac, size_t mac_already, u_int discard)
1.159 markus 388: {
1.201 markus 389: struct session_state *state = ssh->state;
390: int r;
391:
392: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
393: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
394: return r;
395: return SSH_ERR_MAC_INVALID;
396: }
1.234 markus 397: /*
398: * Record number of bytes over which the mac has already
399: * been computed in order to minimize timing attacks.
400: */
401: if (mac && mac->enabled) {
1.201 markus 402: state->packet_discard_mac = mac;
1.234 markus 403: state->packet_discard_mac_already = mac_already;
404: }
405: if (sshbuf_len(state->input) >= discard)
406: return ssh_packet_stop_discard(ssh);
1.201 markus 407: state->packet_discard = discard - sshbuf_len(state->input);
408: return 0;
1.159 markus 409: }
410:
1.19 markus 411: /* Returns 1 if remote host is connected via socket, 0 if not. */
412:
413: int
1.201 markus 414: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 415: {
1.271 djm 416: struct session_state *state;
1.19 markus 417: struct sockaddr_storage from, to;
418: socklen_t fromlen, tolen;
419:
1.271 djm 420: if (ssh == NULL || ssh->state == NULL)
421: return 0;
422:
423: state = ssh->state;
1.230 djm 424: if (state->connection_in == -1 || state->connection_out == -1)
425: return 0;
1.19 markus 426: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 427: if (state->connection_in == state->connection_out)
1.19 markus 428: return 1;
429: fromlen = sizeof(from);
430: memset(&from, 0, sizeof(from));
1.201 markus 431: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.286 deraadt 432: &fromlen) == -1)
1.19 markus 433: return 0;
434: tolen = sizeof(to);
435: memset(&to, 0, sizeof(to));
1.201 markus 436: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.286 deraadt 437: &tolen) == -1)
1.19 markus 438: return 0;
439: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
440: return 0;
441: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
442: return 0;
443: return 1;
444: }
445:
1.91 markus 446: void
1.201 markus 447: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 448: {
1.201 markus 449: if (ibytes)
450: *ibytes = ssh->state->p_read.bytes;
451: if (obytes)
452: *obytes = ssh->state->p_send.bytes;
1.91 markus 453: }
1.125 deraadt 454:
1.91 markus 455: int
1.201 markus 456: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 457: {
1.298 djm 458: return get_sock_af(ssh->state->connection_out);
1.19 markus 459: }
460:
1.1 deraadt 461: /* Sets the connection into non-blocking mode. */
462:
1.2 provos 463: void
1.201 markus 464: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 465: {
1.14 markus 466: /* Set the socket into non-blocking mode. */
1.201 markus 467: set_nonblock(ssh->state->connection_in);
1.14 markus 468:
1.201 markus 469: if (ssh->state->connection_out != ssh->state->connection_in)
470: set_nonblock(ssh->state->connection_out);
1.1 deraadt 471: }
472:
473: /* Returns the socket used for reading. */
474:
1.2 provos 475: int
1.201 markus 476: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 477: {
1.201 markus 478: return ssh->state->connection_in;
1.1 deraadt 479: }
480:
481: /* Returns the descriptor used for writing. */
482:
1.2 provos 483: int
1.201 markus 484: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 485: {
1.201 markus 486: return ssh->state->connection_out;
487: }
488:
489: /*
490: * Returns the IP-address of the remote host as a string. The returned
491: * string must not be freed.
492: */
493:
494: const char *
495: ssh_remote_ipaddr(struct ssh *ssh)
496: {
1.271 djm 497: int sock;
1.220 djm 498:
1.201 markus 499: /* Check whether we have cached the ipaddr. */
1.220 djm 500: if (ssh->remote_ipaddr == NULL) {
501: if (ssh_packet_connection_is_on_socket(ssh)) {
1.271 djm 502: sock = ssh->state->connection_in;
1.220 djm 503: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 djm 504: ssh->remote_port = get_peer_port(sock);
505: ssh->local_ipaddr = get_local_ipaddr(sock);
506: ssh->local_port = get_local_port(sock);
1.220 djm 507: } else {
1.287 tobhe 508: ssh->remote_ipaddr = xstrdup("UNKNOWN");
1.230 djm 509: ssh->remote_port = 65535;
1.287 tobhe 510: ssh->local_ipaddr = xstrdup("UNKNOWN");
1.230 djm 511: ssh->local_port = 65535;
1.220 djm 512: }
513: }
1.201 markus 514: return ssh->remote_ipaddr;
1.1 deraadt 515: }
516:
1.220 djm 517: /* Returns the port number of the remote host. */
518:
519: int
520: ssh_remote_port(struct ssh *ssh)
521: {
522: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
523: return ssh->remote_port;
1.230 djm 524: }
525:
526: /*
527: * Returns the IP-address of the local host as a string. The returned
528: * string must not be freed.
529: */
530:
531: const char *
532: ssh_local_ipaddr(struct ssh *ssh)
533: {
534: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
535: return ssh->local_ipaddr;
536: }
537:
538: /* Returns the port number of the local host. */
539:
540: int
541: ssh_local_port(struct ssh *ssh)
542: {
543: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
544: return ssh->local_port;
1.266 djm 545: }
546:
547: /* Returns the routing domain of the input socket, or NULL if unavailable */
548: const char *
549: ssh_packet_rdomain_in(struct ssh *ssh)
550: {
551: if (ssh->rdomain_in != NULL)
552: return ssh->rdomain_in;
553: if (!ssh_packet_connection_is_on_socket(ssh))
554: return NULL;
555: ssh->rdomain_in = get_rdomain(ssh->state->connection_in);
556: return ssh->rdomain_in;
1.220 djm 557: }
558:
1.1 deraadt 559: /* Closes the connection and clears and frees internal data structures. */
560:
1.257 markus 561: static void
562: ssh_packet_close_internal(struct ssh *ssh, int do_close)
1.1 deraadt 563: {
1.201 markus 564: struct session_state *state = ssh->state;
565: u_int mode;
566:
567: if (!state->initialized)
1.14 markus 568: return;
1.201 markus 569: state->initialized = 0;
1.257 markus 570: if (do_close) {
571: if (state->connection_in == state->connection_out) {
572: close(state->connection_out);
573: } else {
574: close(state->connection_in);
575: close(state->connection_out);
576: }
1.14 markus 577: }
1.201 markus 578: sshbuf_free(state->input);
579: sshbuf_free(state->output);
580: sshbuf_free(state->outgoing_packet);
581: sshbuf_free(state->incoming_packet);
1.257 markus 582: for (mode = 0; mode < MODE_MAX; mode++) {
583: kex_free_newkeys(state->newkeys[mode]); /* current keys */
584: state->newkeys[mode] = NULL;
585: ssh_clear_newkeys(ssh, mode); /* next keys */
586: }
1.288 dtucker 587: #ifdef WITH_ZLIB
1.289 dtucker 588: /* compression state is in shared mem, so we can only release it once */
1.257 markus 589: if (do_close && state->compression_buffer) {
1.201 markus 590: sshbuf_free(state->compression_buffer);
591: if (state->compression_out_started) {
592: z_streamp stream = &state->compression_out_stream;
593: debug("compress outgoing: "
594: "raw data %llu, compressed %llu, factor %.2f",
595: (unsigned long long)stream->total_in,
596: (unsigned long long)stream->total_out,
597: stream->total_in == 0 ? 0.0 :
598: (double) stream->total_out / stream->total_in);
599: if (state->compression_out_failures == 0)
600: deflateEnd(stream);
601: }
602: if (state->compression_in_started) {
1.260 dtucker 603: z_streamp stream = &state->compression_in_stream;
1.201 markus 604: debug("compress incoming: "
605: "raw data %llu, compressed %llu, factor %.2f",
606: (unsigned long long)stream->total_out,
607: (unsigned long long)stream->total_in,
608: stream->total_out == 0 ? 0.0 :
609: (double) stream->total_in / stream->total_out);
610: if (state->compression_in_failures == 0)
611: inflateEnd(stream);
612: }
1.14 markus 613: }
1.288 dtucker 614: #endif /* WITH_ZLIB */
1.235 djm 615: cipher_free(state->send_context);
616: cipher_free(state->receive_context);
617: state->send_context = state->receive_context = NULL;
1.257 markus 618: if (do_close) {
1.277 djm 619: free(ssh->local_ipaddr);
620: ssh->local_ipaddr = NULL;
1.257 markus 621: free(ssh->remote_ipaddr);
622: ssh->remote_ipaddr = NULL;
623: free(ssh->state);
624: ssh->state = NULL;
1.295 markus 625: kex_free(ssh->kex);
626: ssh->kex = NULL;
1.257 markus 627: }
628: }
629:
630: void
631: ssh_packet_close(struct ssh *ssh)
632: {
633: ssh_packet_close_internal(ssh, 1);
634: }
635:
636: void
637: ssh_packet_clear_keys(struct ssh *ssh)
638: {
639: ssh_packet_close_internal(ssh, 0);
1.1 deraadt 640: }
641:
642: /* Sets remote side protocol flags. */
643:
1.2 provos 644: void
1.201 markus 645: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 646: {
1.201 markus 647: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 648: }
649:
650: /* Returns the remote protocol flags set earlier by the above function. */
651:
1.40 markus 652: u_int
1.201 markus 653: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 654: {
1.201 markus 655: return ssh->state->remote_protocol_flags;
1.1 deraadt 656: }
657:
1.16 markus 658: /*
659: * Starts packet compression from the next packet on in both directions.
660: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
661: */
1.1 deraadt 662:
1.201 markus 663: static int
664: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 665: {
1.201 markus 666: if (!ssh->state->compression_buffer &&
1.300 djm 667: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
1.201 markus 668: return SSH_ERR_ALLOC_FAIL;
669: return 0;
1.60 markus 670: }
671:
1.288 dtucker 672: #ifdef WITH_ZLIB
1.201 markus 673: static int
674: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 675: {
1.201 markus 676: if (level < 1 || level > 9)
677: return SSH_ERR_INVALID_ARGUMENT;
678: debug("Enabling compression at level %d.", level);
679: if (ssh->state->compression_out_started == 1)
680: deflateEnd(&ssh->state->compression_out_stream);
681: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
682: case Z_OK:
683: ssh->state->compression_out_started = 1;
684: break;
685: case Z_MEM_ERROR:
686: return SSH_ERR_ALLOC_FAIL;
687: default:
688: return SSH_ERR_INTERNAL_ERROR;
689: }
690: return 0;
1.1 deraadt 691: }
692:
1.201 markus 693: static int
694: start_compression_in(struct ssh *ssh)
695: {
696: if (ssh->state->compression_in_started == 1)
697: inflateEnd(&ssh->state->compression_in_stream);
698: switch (inflateInit(&ssh->state->compression_in_stream)) {
699: case Z_OK:
700: ssh->state->compression_in_started = 1;
701: break;
702: case Z_MEM_ERROR:
703: return SSH_ERR_ALLOC_FAIL;
704: default:
705: return SSH_ERR_INTERNAL_ERROR;
706: }
707: return 0;
1.95 markus 708: }
709:
1.201 markus 710: /* XXX remove need for separate compression buffer */
711: static int
712: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 713: {
1.201 markus 714: u_char buf[4096];
715: int r, status;
716:
717: if (ssh->state->compression_out_started != 1)
718: return SSH_ERR_INTERNAL_ERROR;
719:
720: /* This case is not handled below. */
721: if (sshbuf_len(in) == 0)
722: return 0;
723:
724: /* Input is the contents of the input buffer. */
725: if ((ssh->state->compression_out_stream.next_in =
726: sshbuf_mutable_ptr(in)) == NULL)
727: return SSH_ERR_INTERNAL_ERROR;
728: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
729:
730: /* Loop compressing until deflate() returns with avail_out != 0. */
731: do {
732: /* Set up fixed-size output buffer. */
733: ssh->state->compression_out_stream.next_out = buf;
734: ssh->state->compression_out_stream.avail_out = sizeof(buf);
735:
736: /* Compress as much data into the buffer as possible. */
737: status = deflate(&ssh->state->compression_out_stream,
738: Z_PARTIAL_FLUSH);
739: switch (status) {
740: case Z_MEM_ERROR:
741: return SSH_ERR_ALLOC_FAIL;
742: case Z_OK:
743: /* Append compressed data to output_buffer. */
744: if ((r = sshbuf_put(out, buf, sizeof(buf) -
745: ssh->state->compression_out_stream.avail_out)) != 0)
746: return r;
747: break;
748: case Z_STREAM_ERROR:
749: default:
750: ssh->state->compression_out_failures++;
751: return SSH_ERR_INVALID_FORMAT;
752: }
753: } while (ssh->state->compression_out_stream.avail_out == 0);
754: return 0;
1.1 deraadt 755: }
756:
1.201 markus 757: static int
758: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 759: {
1.201 markus 760: u_char buf[4096];
761: int r, status;
1.1 deraadt 762:
1.201 markus 763: if (ssh->state->compression_in_started != 1)
764: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 765:
1.201 markus 766: if ((ssh->state->compression_in_stream.next_in =
767: sshbuf_mutable_ptr(in)) == NULL)
768: return SSH_ERR_INTERNAL_ERROR;
769: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 770:
1.201 markus 771: for (;;) {
772: /* Set up fixed-size output buffer. */
773: ssh->state->compression_in_stream.next_out = buf;
774: ssh->state->compression_in_stream.avail_out = sizeof(buf);
775:
776: status = inflate(&ssh->state->compression_in_stream,
1.305 djm 777: Z_SYNC_FLUSH);
1.201 markus 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:
1.303 djm 854: debug2_f("mode %d", mode);
1.57 markus 855:
1.88 markus 856: if (mode == MODE_OUT) {
1.235 djm 857: ccp = &state->send_context;
1.115 avsm 858: crypt_type = CIPHER_ENCRYPT;
1.236 markus 859: ps = &state->p_send;
1.201 markus 860: max_blocks = &state->max_blocks_out;
1.88 markus 861: } else {
1.235 djm 862: ccp = &state->receive_context;
1.115 avsm 863: crypt_type = CIPHER_DECRYPT;
1.236 markus 864: ps = &state->p_read;
1.201 markus 865: max_blocks = &state->max_blocks_in;
1.88 markus 866: }
1.201 markus 867: if (state->newkeys[mode] != NULL) {
1.297 djm 868: debug_f("rekeying %s, input %llu bytes %llu blocks, "
1.300 djm 869: "output %llu bytes %llu blocks", dir,
870: (unsigned long long)state->p_read.bytes,
871: (unsigned long long)state->p_read.blocks,
872: (unsigned long long)state->p_send.bytes,
873: (unsigned long long)state->p_send.blocks);
1.257 markus 874: kex_free_newkeys(state->newkeys[mode]);
875: state->newkeys[mode] = NULL;
1.57 markus 876: }
1.236 markus 877: /* note that both bytes and the seqnr are not reset */
878: ps->packets = ps->blocks = 0;
1.201 markus 879: /* move newkeys from kex to state */
880: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
881: return SSH_ERR_INTERNAL_ERROR;
882: ssh->kex->newkeys[mode] = NULL;
883: enc = &state->newkeys[mode]->enc;
884: mac = &state->newkeys[mode]->mac;
885: comp = &state->newkeys[mode]->comp;
886: if (cipher_authlen(enc->cipher) == 0) {
887: if ((r = mac_init(mac)) != 0)
888: return r;
889: }
890: mac->enabled = 1;
1.303 djm 891: DBG(debug_f("cipher_init: %s", dir));
1.279 djm 892: cipher_free(*ccp);
893: *ccp = NULL;
1.235 djm 894: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 895: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 896: return r;
897: if (!state->cipher_warning_done &&
1.235 djm 898: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 899: error("Warning: %s", wmsg);
900: state->cipher_warning_done = 1;
901: }
1.91 markus 902: /* Deleting the keys does not gain extra security */
1.192 djm 903: /* explicit_bzero(enc->iv, enc->block_size);
904: explicit_bzero(enc->key, enc->key_len);
905: explicit_bzero(mac->key, mac->key_len); */
1.275 sf 906: if ((comp->type == COMP_ZLIB ||
907: (comp->type == COMP_DELAYED &&
1.300 djm 908: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 909: if ((r = ssh_packet_init_compression(ssh)) < 0)
910: return r;
911: if (mode == MODE_OUT) {
912: if ((r = start_compression_out(ssh, 6)) != 0)
913: return r;
914: } else {
915: if ((r = start_compression_in(ssh)) != 0)
916: return r;
917: }
1.57 markus 918: comp->enabled = 1;
919: }
1.109 markus 920: /*
921: * The 2^(blocksize*2) limit is too expensive for 3DES,
1.254 djm 922: * so enforce a 1GB limit for small blocksizes.
1.261 dtucker 923: * See RFC4344 section 3.2.
1.109 markus 924: */
925: if (enc->block_size >= 16)
926: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
927: else
928: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 929: if (state->rekey_limit)
1.237 deraadt 930: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 931: state->rekey_limit / enc->block_size);
1.283 djm 932: debug("rekey %s after %llu blocks", dir,
933: (unsigned long long)*max_blocks);
1.201 markus 934: return 0;
1.57 markus 935: }
936:
1.228 djm 937: #define MAX_PACKETS (1U<<31)
938: static int
939: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
940: {
941: struct session_state *state = ssh->state;
942: u_int32_t out_blocks;
943:
944: /* XXX client can't cope with rekeying pre-auth */
945: if (!state->after_authentication)
946: return 0;
947:
948: /* Haven't keyed yet or KEX in progress. */
1.278 djm 949: if (ssh_packet_is_rekeying(ssh))
1.228 djm 950: return 0;
951:
952: /* Peer can't rekey */
953: if (ssh->compat & SSH_BUG_NOREKEY)
954: return 0;
955:
956: /*
957: * Permit one packet in or out per rekey - this allows us to
958: * make progress when rekey limits are very small.
959: */
960: if (state->p_send.packets == 0 && state->p_read.packets == 0)
961: return 0;
962:
963: /* Time-based rekeying */
964: if (state->rekey_interval != 0 &&
1.244 dtucker 965: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 966: return 1;
967:
1.261 dtucker 968: /*
1.308 djm 969: * Always rekey when MAX_PACKETS sent in either direction
1.261 dtucker 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:
1.304 jsg 976: /* Rekey after (cipher-specific) maximum blocks */
1.237 deraadt 977: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 978: state->newkeys[MODE_OUT]->enc.block_size);
979: return (state->max_blocks_out &&
980: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
981: (state->max_blocks_in &&
982: (state->p_read.blocks > state->max_blocks_in));
983: }
984:
1.301 djm 985: int
986: ssh_packet_check_rekey(struct ssh *ssh)
987: {
988: if (!ssh_packet_need_rekeying(ssh, 0))
989: return 0;
990: debug3_f("rekex triggered");
991: return kex_start_rekex(ssh);
992: }
993:
1.16 markus 994: /*
1.118 markus 995: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 996: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 997: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
998: */
1.201 markus 999: static int
1000: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 1001: {
1.201 markus 1002: struct session_state *state = ssh->state;
1003: struct sshcomp *comp = NULL;
1004: int r, mode;
1.118 markus 1005:
1006: /*
1007: * Remember that we are past the authentication step, so rekeying
1.275 sf 1008: * with COMP_DELAYED will turn on compression immediately.
1.118 markus 1009: */
1.201 markus 1010: state->after_authentication = 1;
1.118 markus 1011: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 1012: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 1013: if (state->newkeys[mode] == NULL)
1.145 markus 1014: continue;
1.201 markus 1015: comp = &state->newkeys[mode]->comp;
1.275 sf 1016: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 1017: if ((r = ssh_packet_init_compression(ssh)) != 0)
1018: return r;
1019: if (mode == MODE_OUT) {
1020: if ((r = start_compression_out(ssh, 6)) != 0)
1021: return r;
1022: } else {
1023: if ((r = start_compression_in(ssh)) != 0)
1024: return r;
1025: }
1.118 markus 1026: comp->enabled = 1;
1027: }
1028: }
1.201 markus 1029: return 0;
1.118 markus 1030: }
1031:
1.226 djm 1032: /* Used to mute debug logging for noisy packet types */
1.242 markus 1033: int
1.226 djm 1034: ssh_packet_log_type(u_char type)
1035: {
1036: switch (type) {
1.311 ! djm 1037: case SSH2_MSG_PING:
! 1038: case SSH2_MSG_PONG:
1.226 djm 1039: case SSH2_MSG_CHANNEL_DATA:
1040: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1041: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1042: return 0;
1043: default:
1044: return 1;
1045: }
1046: }
1047:
1.118 markus 1048: /*
1.25 markus 1049: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1050: */
1.201 markus 1051: int
1052: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1053: {
1.201 markus 1054: struct session_state *state = ssh->state;
1.200 markus 1055: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1056: u_char tmp, padlen, pad = 0;
1.201 markus 1057: u_int authlen = 0, aadlen = 0;
1058: u_int len;
1059: struct sshenc *enc = NULL;
1060: struct sshmac *mac = NULL;
1061: struct sshcomp *comp = NULL;
1062: int r, block_size;
1063:
1064: if (state->newkeys[MODE_OUT] != NULL) {
1065: enc = &state->newkeys[MODE_OUT]->enc;
1066: mac = &state->newkeys[MODE_OUT]->mac;
1067: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1068: /* disable mac for authenticated encryption */
1069: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1070: mac = NULL;
1.25 markus 1071: }
1.88 markus 1072: block_size = enc ? enc->block_size : 8;
1.180 markus 1073: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1074:
1.201 markus 1075: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1076: if (ssh_packet_log_type(type))
1077: debug3("send packet: type %u", type);
1.25 markus 1078: #ifdef PACKET_DEBUG
1079: fprintf(stderr, "plain: ");
1.201 markus 1080: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1081: #endif
1082:
1083: if (comp && comp->enabled) {
1.201 markus 1084: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1085: /* skip header, compress only payload */
1.201 markus 1086: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1087: goto out;
1088: sshbuf_reset(state->compression_buffer);
1089: if ((r = compress_buffer(ssh, state->outgoing_packet,
1090: state->compression_buffer)) != 0)
1091: goto out;
1092: sshbuf_reset(state->outgoing_packet);
1093: if ((r = sshbuf_put(state->outgoing_packet,
1094: "\0\0\0\0\0", 5)) != 0 ||
1095: (r = sshbuf_putb(state->outgoing_packet,
1096: state->compression_buffer)) != 0)
1097: goto out;
1098: DBG(debug("compression: raw %d compressed %zd", len,
1099: sshbuf_len(state->outgoing_packet)));
1.25 markus 1100: }
1101:
1102: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1103: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1104:
1105: /*
1106: * calc size of padding, alloc space, get random data,
1107: * minimum padding is 4 bytes
1108: */
1.178 markus 1109: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1110: padlen = block_size - (len % block_size);
1111: if (padlen < 4)
1112: padlen += block_size;
1.201 markus 1113: if (state->extra_pad) {
1.233 djm 1114: tmp = state->extra_pad;
1.201 markus 1115: state->extra_pad =
1.237 deraadt 1116: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1117: /* check if roundup overflowed */
1118: if (state->extra_pad < tmp)
1119: return SSH_ERR_INVALID_ARGUMENT;
1120: tmp = (len + padlen) % state->extra_pad;
1121: /* Check whether pad calculation below will underflow */
1122: if (tmp > state->extra_pad)
1123: return SSH_ERR_INVALID_ARGUMENT;
1124: pad = state->extra_pad - tmp;
1.297 djm 1125: DBG(debug3_f("adding %d (len %d padlen %d extra_pad %d)",
1126: pad, len, padlen, state->extra_pad));
1.233 djm 1127: tmp = padlen;
1.71 markus 1128: padlen += pad;
1.233 djm 1129: /* Check whether padlen calculation overflowed */
1130: if (padlen < tmp)
1131: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1132: state->extra_pad = 0;
1.71 markus 1133: }
1.201 markus 1134: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1135: goto out;
1.235 djm 1136: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1137: /* random padding */
1.201 markus 1138: arc4random_buf(cp, padlen);
1.32 markus 1139: } else {
1140: /* clear padding */
1.192 djm 1141: explicit_bzero(cp, padlen);
1.25 markus 1142: }
1.178 markus 1143: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1144: len = sshbuf_len(state->outgoing_packet);
1145: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1146: if (cp == NULL) {
1147: r = SSH_ERR_INTERNAL_ERROR;
1148: goto out;
1149: }
1.25 markus 1150: /* packet_length includes payload, padding and padding length field */
1.201 markus 1151: POKE_U32(cp, len - 4);
1.89 markus 1152: cp[4] = padlen;
1.178 markus 1153: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1154: len, padlen, aadlen));
1.25 markus 1155:
1156: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1157: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1158: if ((r = mac_compute(mac, state->p_send.seqnr,
1159: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1160: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1161: goto out;
1162: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1163: }
1164: /* encrypt packet and append to output buffer. */
1.201 markus 1165: if ((r = sshbuf_reserve(state->output,
1166: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1167: goto out;
1.235 djm 1168: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1169: sshbuf_ptr(state->outgoing_packet),
1170: len - aadlen, aadlen, authlen)) != 0)
1171: goto out;
1.25 markus 1172: /* append unencrypted MAC */
1.178 markus 1173: if (mac && mac->enabled) {
1174: if (mac->etm) {
1175: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1176: if ((r = mac_compute(mac, state->p_send.seqnr,
1177: cp, len, macbuf, sizeof(macbuf))) != 0)
1178: goto out;
1.178 markus 1179: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1180: state->p_send.seqnr));
1.178 markus 1181: }
1.201 markus 1182: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1183: goto out;
1.178 markus 1184: }
1.25 markus 1185: #ifdef PACKET_DEBUG
1186: fprintf(stderr, "encrypted: ");
1.201 markus 1187: sshbuf_dump(state->output, stderr);
1.25 markus 1188: #endif
1.29 markus 1189: /* increment sequence number for outgoing packets */
1.201 markus 1190: if (++state->p_send.seqnr == 0)
1.106 itojun 1191: logit("outgoing seqnr wraps around");
1.201 markus 1192: if (++state->p_send.packets == 0)
1193: if (!(ssh->compat & SSH_BUG_NOREKEY))
1194: return SSH_ERR_NEED_REKEY;
1195: state->p_send.blocks += len / block_size;
1196: state->p_send.bytes += len;
1197: sshbuf_reset(state->outgoing_packet);
1.25 markus 1198:
1.57 markus 1199: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1200: r = ssh_set_newkeys(ssh, MODE_OUT);
1201: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1202: r = ssh_packet_enable_delayed_compress(ssh);
1203: else
1204: r = 0;
1205: out:
1206: return r;
1.25 markus 1207: }
1208:
1.228 djm 1209: /* returns non-zero if the specified packet type is usec by KEX */
1210: static int
1211: ssh_packet_type_is_kex(u_char type)
1212: {
1213: return
1214: type >= SSH2_MSG_TRANSPORT_MIN &&
1215: type <= SSH2_MSG_TRANSPORT_MAX &&
1216: type != SSH2_MSG_SERVICE_REQUEST &&
1217: type != SSH2_MSG_SERVICE_ACCEPT &&
1218: type != SSH2_MSG_EXT_INFO;
1219: }
1220:
1.201 markus 1221: int
1222: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1223: {
1.201 markus 1224: struct session_state *state = ssh->state;
1.105 markus 1225: struct packet *p;
1.201 markus 1226: u_char type;
1.228 djm 1227: int r, need_rekey;
1.105 markus 1228:
1.228 djm 1229: if (sshbuf_len(state->outgoing_packet) < 6)
1230: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1231: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1232: need_rekey = !ssh_packet_type_is_kex(type) &&
1233: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1234:
1.228 djm 1235: /*
1236: * During rekeying we can only send key exchange messages.
1237: * Queue everything else.
1238: */
1239: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1240: if (need_rekey)
1.297 djm 1241: debug3_f("rekex triggered");
1.228 djm 1242: debug("enqueue packet: %u", type);
1243: p = calloc(1, sizeof(*p));
1244: if (p == NULL)
1245: return SSH_ERR_ALLOC_FAIL;
1246: p->type = type;
1247: p->payload = state->outgoing_packet;
1248: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1249: state->outgoing_packet = sshbuf_new();
1250: if (state->outgoing_packet == NULL)
1251: return SSH_ERR_ALLOC_FAIL;
1252: if (need_rekey) {
1253: /*
1254: * This packet triggered a rekey, so send the
1255: * KEXINIT now.
1256: * NB. reenters this function via kex_start_rekex().
1257: */
1258: return kex_start_rekex(ssh);
1.105 markus 1259: }
1.228 djm 1260: return 0;
1.105 markus 1261: }
1262:
1263: /* rekeying starts with sending KEXINIT */
1264: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1265: state->rekeying = 1;
1.105 markus 1266:
1.201 markus 1267: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1268: return r;
1.105 markus 1269:
1270: /* after a NEWKEYS message we can send the complete queue */
1271: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1272: state->rekeying = 0;
1273: state->rekey_time = monotime();
1274: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1275: type = p->type;
1.228 djm 1276: /*
1277: * If this packet triggers a rekex, then skip the
1278: * remaining packets in the queue for now.
1279: * NB. re-enters this function via kex_start_rekex.
1280: */
1281: if (ssh_packet_need_rekeying(ssh,
1282: sshbuf_len(p->payload))) {
1.297 djm 1283: debug3_f("queued packet triggered rekex");
1.228 djm 1284: return kex_start_rekex(ssh);
1285: }
1.105 markus 1286: debug("dequeue packet: %u", type);
1.201 markus 1287: sshbuf_free(state->outgoing_packet);
1288: state->outgoing_packet = p->payload;
1289: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1290: memset(p, 0, sizeof(*p));
1.186 djm 1291: free(p);
1.201 markus 1292: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1293: return r;
1.105 markus 1294: }
1295: }
1.201 markus 1296: return 0;
1.25 markus 1297: }
1298:
1299: /*
1.16 markus 1300: * Waits until a packet has been received, and returns its type. Note that
1301: * no other data is processed until this returns, so this function should not
1302: * be used during the interactive session.
1303: */
1.1 deraadt 1304:
1.2 provos 1305: int
1.201 markus 1306: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1307: {
1.201 markus 1308: struct session_state *state = ssh->state;
1.309 dtucker 1309: int len, r, ms_remain = 0;
1.302 deraadt 1310: struct pollfd pfd;
1.14 markus 1311: char buf[8192];
1.302 deraadt 1312: struct timeval start;
1313: struct timespec timespec, *timespecp = NULL;
1.155 deraadt 1314:
1.25 markus 1315: DBG(debug("packet_read()"));
1.14 markus 1316:
1.205 djm 1317: /*
1318: * Since we are blocking, ensure that all written packets have
1319: * been sent.
1320: */
1.210 markus 1321: if ((r = ssh_packet_write_wait(ssh)) != 0)
1322: goto out;
1.14 markus 1323:
1324: /* Stay in the loop until we have received a complete packet. */
1325: for (;;) {
1326: /* Try to read a packet from the buffer. */
1.201 markus 1327: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1328: if (r != 0)
1329: break;
1.14 markus 1330: /* If we got a packet, return it. */
1.201 markus 1331: if (*typep != SSH_MSG_NONE)
1332: break;
1.16 markus 1333: /*
1334: * Otherwise, wait for some data to arrive, add it to the
1335: * buffer, and try again.
1336: */
1.302 deraadt 1337: pfd.fd = state->connection_in;
1338: pfd.events = POLLIN;
1.16 markus 1339:
1.201 markus 1340: if (state->packet_timeout_ms > 0) {
1341: ms_remain = state->packet_timeout_ms;
1.302 deraadt 1342: timespecp = ×pec;
1.154 dtucker 1343: }
1.14 markus 1344: /* Wait for some data to arrive. */
1.154 dtucker 1345: for (;;) {
1.291 markus 1346: if (state->packet_timeout_ms > 0) {
1.302 deraadt 1347: ms_to_timespec(×pec, ms_remain);
1.267 dtucker 1348: monotime_tv(&start);
1.154 dtucker 1349: }
1.302 deraadt 1350: if ((r = ppoll(&pfd, 1, timespecp, NULL)) >= 0)
1.154 dtucker 1351: break;
1.270 dtucker 1352: if (errno != EAGAIN && errno != EINTR) {
1353: r = SSH_ERR_SYSTEM_ERROR;
1354: goto out;
1355: }
1.291 markus 1356: if (state->packet_timeout_ms <= 0)
1.154 dtucker 1357: continue;
1358: ms_subtract_diff(&start, &ms_remain);
1359: if (ms_remain <= 0) {
1.201 markus 1360: r = 0;
1.154 dtucker 1361: break;
1362: }
1363: }
1.246 djm 1364: if (r == 0) {
1365: r = SSH_ERR_CONN_TIMEOUT;
1366: goto out;
1367: }
1.14 markus 1368: /* Read data from the socket. */
1.222 markus 1369: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1370: if (len == 0) {
1371: r = SSH_ERR_CONN_CLOSED;
1372: goto out;
1373: }
1.286 deraadt 1374: if (len == -1) {
1.210 markus 1375: r = SSH_ERR_SYSTEM_ERROR;
1376: goto out;
1377: }
1.204 djm 1378:
1.14 markus 1379: /* Append it to the buffer. */
1.204 djm 1380: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1381: goto out;
1.14 markus 1382: }
1.210 markus 1383: out:
1.201 markus 1384: return r;
1.1 deraadt 1385: }
1386:
1.77 djm 1387: int
1.201 markus 1388: ssh_packet_read(struct ssh *ssh)
1.77 djm 1389: {
1.201 markus 1390: u_char type;
1391: int r;
1392:
1393: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1.297 djm 1394: fatal_fr(r, "read");
1.201 markus 1395: return type;
1.77 djm 1396: }
1397:
1.16 markus 1398: /*
1399: * Waits until a packet has been received, verifies that its type matches
1400: * that given, and gives a fatal error and exits if there is a mismatch.
1401: */
1.1 deraadt 1402:
1.205 djm 1403: int
1404: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1405: {
1.205 djm 1406: int r;
1407: u_char type;
1.1 deraadt 1408:
1.205 djm 1409: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1410: return r;
1411: if (type != expected_type) {
1412: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1413: "Protocol error: expected packet type %d, got %d",
1.205 djm 1414: expected_type, type)) != 0)
1415: return r;
1416: return SSH_ERR_PROTOCOL_ERROR;
1417: }
1418: return 0;
1.1 deraadt 1419: }
1.14 markus 1420:
1.242 markus 1421: static int
1422: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1423: {
1424: struct session_state *state = ssh->state;
1425: const u_char *cp;
1426: size_t need;
1427: int r;
1428:
1429: if (ssh->kex)
1430: return SSH_ERR_INTERNAL_ERROR;
1431: *typep = SSH_MSG_NONE;
1432: cp = sshbuf_ptr(state->input);
1433: if (state->packlen == 0) {
1434: if (sshbuf_len(state->input) < 4 + 1)
1435: return 0; /* packet is incomplete */
1436: state->packlen = PEEK_U32(cp);
1437: if (state->packlen < 4 + 1 ||
1438: state->packlen > PACKET_MAX_SIZE)
1439: return SSH_ERR_MESSAGE_INCOMPLETE;
1440: }
1441: need = state->packlen + 4;
1442: if (sshbuf_len(state->input) < need)
1443: return 0; /* packet is incomplete */
1444: sshbuf_reset(state->incoming_packet);
1445: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1446: state->packlen)) != 0 ||
1447: (r = sshbuf_consume(state->input, need)) != 0 ||
1448: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1449: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1450: return r;
1451: if (ssh_packet_log_type(*typep))
1.297 djm 1452: debug3_f("type %u", *typep);
1.242 markus 1453: /* sshbuf_dump(state->incoming_packet, stderr); */
1454: /* reset for next packet */
1455: state->packlen = 0;
1456: return r;
1457: }
1458:
1.201 markus 1459: int
1460: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1461: {
1.201 markus 1462: struct session_state *state = ssh->state;
1.40 markus 1463: u_int padlen, need;
1.231 djm 1464: u_char *cp;
1.201 markus 1465: u_int maclen, aadlen = 0, authlen = 0, block_size;
1466: struct sshenc *enc = NULL;
1467: struct sshmac *mac = NULL;
1468: struct sshcomp *comp = NULL;
1.200 markus 1469: int r;
1.201 markus 1470:
1.242 markus 1471: if (state->mux)
1472: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1473:
1.201 markus 1474: *typep = SSH_MSG_NONE;
1475:
1476: if (state->packet_discard)
1477: return 0;
1478:
1479: if (state->newkeys[MODE_IN] != NULL) {
1480: enc = &state->newkeys[MODE_IN]->enc;
1481: mac = &state->newkeys[MODE_IN]->mac;
1482: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1483: /* disable mac for authenticated encryption */
1484: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1485: mac = NULL;
1.25 markus 1486: }
1487: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1488: block_size = enc ? enc->block_size : 8;
1.180 markus 1489: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1490:
1.201 markus 1491: if (aadlen && state->packlen == 0) {
1.235 djm 1492: if (cipher_get_length(state->receive_context,
1.201 markus 1493: &state->packlen, state->p_read.seqnr,
1494: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1495: return 0;
1496: if (state->packlen < 1 + 4 ||
1497: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1498: #ifdef PACKET_DEBUG
1.201 markus 1499: sshbuf_dump(state->input, stderr);
1.178 markus 1500: #endif
1.201 markus 1501: logit("Bad packet length %u.", state->packlen);
1502: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1503: return r;
1.217 djm 1504: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1505: }
1.201 markus 1506: sshbuf_reset(state->incoming_packet);
1507: } else if (state->packlen == 0) {
1.25 markus 1508: /*
1509: * check if input size is less than the cipher block size,
1510: * decrypt first block and extract length of incoming packet
1511: */
1.201 markus 1512: if (sshbuf_len(state->input) < block_size)
1513: return 0;
1514: sshbuf_reset(state->incoming_packet);
1515: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1516: &cp)) != 0)
1517: goto out;
1.235 djm 1518: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1519: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1520: block_size, 0, 0)) != 0)
1521: goto out;
1522: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1523: if (state->packlen < 1 + 4 ||
1524: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1525: #ifdef PACKET_DEBUG
1.201 markus 1526: fprintf(stderr, "input: \n");
1527: sshbuf_dump(state->input, stderr);
1528: fprintf(stderr, "incoming_packet: \n");
1529: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1530: #endif
1.201 markus 1531: logit("Bad packet length %u.", state->packlen);
1.234 markus 1532: return ssh_packet_start_discard(ssh, enc, mac, 0,
1533: PACKET_MAX_SIZE);
1.25 markus 1534: }
1.201 markus 1535: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1536: goto out;
1.25 markus 1537: }
1.201 markus 1538: DBG(debug("input: packet len %u", state->packlen+4));
1539:
1.178 markus 1540: if (aadlen) {
1541: /* only the payload is encrypted */
1.201 markus 1542: need = state->packlen;
1.178 markus 1543: } else {
1544: /*
1545: * the payload size and the payload are encrypted, but we
1546: * have a partial packet of block_size bytes
1547: */
1.201 markus 1548: need = 4 + state->packlen - block_size;
1.178 markus 1549: }
1.180 markus 1550: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1551: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1552: if (need % block_size != 0) {
1553: logit("padding error: need %d block %d mod %d",
1.25 markus 1554: need, block_size, need % block_size);
1.234 markus 1555: return ssh_packet_start_discard(ssh, enc, mac, 0,
1556: PACKET_MAX_SIZE - block_size);
1.158 markus 1557: }
1.25 markus 1558: /*
1559: * check if the entire packet has been received and
1.178 markus 1560: * decrypt into incoming_packet:
1561: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1562: * 'need' bytes are encrypted, followed by either
1563: * 'authlen' bytes of authentication tag or
1.178 markus 1564: * 'maclen' bytes of message authentication code.
1.25 markus 1565: */
1.201 markus 1566: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1567: return 0; /* packet is incomplete */
1.25 markus 1568: #ifdef PACKET_DEBUG
1569: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1570: sshbuf_dump(state->input, stderr);
1.25 markus 1571: #endif
1.231 djm 1572: /* EtM: check mac over encrypted input */
1.201 markus 1573: if (mac && mac->enabled && mac->etm) {
1.231 djm 1574: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1575: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1576: sshbuf_ptr(state->input) + aadlen + need + authlen,
1577: maclen)) != 0) {
1578: if (r == SSH_ERR_MAC_INVALID)
1579: logit("Corrupted MAC on input.");
1.201 markus 1580: goto out;
1.231 djm 1581: }
1.201 markus 1582: }
1583: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1584: &cp)) != 0)
1585: goto out;
1.235 djm 1586: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1587: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1588: goto out;
1589: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1590: goto out;
1.29 markus 1591: if (mac && mac->enabled) {
1.231 djm 1592: /* Not EtM: check MAC over cleartext */
1593: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1594: sshbuf_ptr(state->incoming_packet),
1595: sshbuf_len(state->incoming_packet),
1596: sshbuf_ptr(state->input), maclen)) != 0) {
1597: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1598: goto out;
1.159 markus 1599: logit("Corrupted MAC on input.");
1.247 markus 1600: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1601: return SSH_ERR_INTERNAL_ERROR;
1602: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1603: sshbuf_len(state->incoming_packet),
1.247 markus 1604: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1605: }
1.231 djm 1606: /* Remove MAC from input buffer */
1.201 markus 1607: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1608: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1609: goto out;
1.25 markus 1610: }
1.77 djm 1611: if (seqnr_p != NULL)
1.201 markus 1612: *seqnr_p = state->p_read.seqnr;
1613: if (++state->p_read.seqnr == 0)
1.106 itojun 1614: logit("incoming seqnr wraps around");
1.201 markus 1615: if (++state->p_read.packets == 0)
1616: if (!(ssh->compat & SSH_BUG_NOREKEY))
1617: return SSH_ERR_NEED_REKEY;
1618: state->p_read.blocks += (state->packlen + 4) / block_size;
1619: state->p_read.bytes += state->packlen + 4;
1.25 markus 1620:
1621: /* get padlen */
1.201 markus 1622: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1623: DBG(debug("input: padlen %d", padlen));
1.205 djm 1624: if (padlen < 4) {
1625: if ((r = sshpkt_disconnect(ssh,
1626: "Corrupted padlen %d on input.", padlen)) != 0 ||
1627: (r = ssh_packet_write_wait(ssh)) != 0)
1628: return r;
1629: return SSH_ERR_CONN_CORRUPT;
1630: }
1.25 markus 1631:
1632: /* skip packet size + padlen, discard padding */
1.201 markus 1633: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1634: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1635: goto out;
1.25 markus 1636:
1.201 markus 1637: DBG(debug("input: len before de-compress %zd",
1638: sshbuf_len(state->incoming_packet)));
1.25 markus 1639: if (comp && comp->enabled) {
1.201 markus 1640: sshbuf_reset(state->compression_buffer);
1641: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1642: state->compression_buffer)) != 0)
1643: goto out;
1644: sshbuf_reset(state->incoming_packet);
1645: if ((r = sshbuf_putb(state->incoming_packet,
1646: state->compression_buffer)) != 0)
1647: goto out;
1648: DBG(debug("input: len after de-compress %zd",
1649: sshbuf_len(state->incoming_packet)));
1.25 markus 1650: }
1651: /*
1652: * get packet type, implies consume.
1653: * return length of payload (without type field)
1654: */
1.201 markus 1655: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1656: goto out;
1.226 djm 1657: if (ssh_packet_log_type(*typep))
1658: debug3("receive packet: type %u", *typep);
1.311 ! djm 1659: if (*typep < SSH2_MSG_MIN) {
1.205 djm 1660: if ((r = sshpkt_disconnect(ssh,
1661: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1662: (r = ssh_packet_write_wait(ssh)) != 0)
1663: return r;
1664: return SSH_ERR_PROTOCOL_ERROR;
1665: }
1.243 djm 1666: if (state->hook_in != NULL &&
1667: (r = state->hook_in(ssh, state->incoming_packet, typep,
1668: state->hook_in_ctx)) != 0)
1669: return r;
1.238 markus 1670: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1671: r = ssh_packet_enable_delayed_compress(ssh);
1672: else
1673: r = 0;
1.25 markus 1674: #ifdef PACKET_DEBUG
1.201 markus 1675: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1676: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1677: #endif
1.62 markus 1678: /* reset for next packet */
1.201 markus 1679: state->packlen = 0;
1.228 djm 1680:
1.301 djm 1681: if ((r = ssh_packet_check_rekey(ssh)) != 0)
1682: return r;
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;
1.311 ! djm 1694: const u_char *d;
! 1695: size_t len;
1.62 markus 1696:
1.25 markus 1697: for (;;) {
1.201 markus 1698: msg = NULL;
1.249 djm 1699: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1700: if (r != 0)
1701: return r;
1702: if (*typep) {
1703: state->keep_alive_timeouts = 0;
1704: DBG(debug("received packet type %d", *typep));
1705: }
1706: switch (*typep) {
1707: case SSH2_MSG_IGNORE:
1708: debug3("Received SSH2_MSG_IGNORE");
1709: break;
1710: case SSH2_MSG_DEBUG:
1711: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1712: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1713: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1714: free(msg);
1.201 markus 1715: return r;
1.48 stevesk 1716: }
1.249 djm 1717: debug("Remote: %.900s", msg);
1718: free(msg);
1719: break;
1720: case SSH2_MSG_DISCONNECT:
1721: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1722: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1723: return r;
1724: /* Ignore normal client exit notifications */
1725: do_log2(ssh->state->server_side &&
1726: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1727: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1728: "Received disconnect from %s port %d:"
1729: "%u: %.400s", ssh_remote_ipaddr(ssh),
1730: ssh_remote_port(ssh), reason, msg);
1731: free(msg);
1732: return SSH_ERR_DISCONNECTED;
1733: case SSH2_MSG_UNIMPLEMENTED:
1734: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1735: return r;
1736: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1737: seqnr);
1.311 ! djm 1738: break;
! 1739: case SSH2_MSG_PING:
! 1740: if ((r = sshpkt_get_string_direct(ssh, &d, &len)) != 0)
! 1741: return r;
! 1742: DBG(debug("Received SSH2_MSG_PING len %zu", len));
! 1743: if ((r = sshpkt_start(ssh, SSH2_MSG_PONG)) != 0 ||
! 1744: (r = sshpkt_put_string(ssh, d, len)) != 0 ||
! 1745: (r = sshpkt_send(ssh)) != 0)
! 1746: return r;
! 1747: break;
! 1748: case SSH2_MSG_PONG:
! 1749: if ((r = sshpkt_get_string_direct(ssh,
! 1750: NULL, &len)) != 0)
! 1751: return r;
! 1752: DBG(debug("Received SSH2_MSG_PONG len %zu", len));
1.249 djm 1753: break;
1754: default:
1755: return 0;
1.25 markus 1756: }
1757: }
1758: }
1759:
1.16 markus 1760: /*
1.306 djm 1761: * Buffers the supplied input data. This is intended to be used together
1762: * with packet_read_poll().
1.16 markus 1763: */
1.204 djm 1764: int
1.201 markus 1765: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1766: {
1.201 markus 1767: struct session_state *state = ssh->state;
1768: int r;
1769:
1770: if (state->packet_discard) {
1771: state->keep_alive_timeouts = 0; /* ?? */
1772: if (len >= state->packet_discard) {
1773: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1774: return r;
1.201 markus 1775: }
1776: state->packet_discard -= len;
1.204 djm 1777: return 0;
1.159 markus 1778: }
1.306 djm 1779: if ((r = sshbuf_put(state->input, buf, len)) != 0)
1.204 djm 1780: return r;
1781:
1.307 djm 1782: return 0;
1783: }
1784:
1785: /* Reads and buffers data from the specified fd */
1786: int
1787: ssh_packet_process_read(struct ssh *ssh, int fd)
1788: {
1789: struct session_state *state = ssh->state;
1790: int r;
1791: size_t rlen;
1792:
1793: if ((r = sshbuf_read(fd, state->input, PACKET_MAX_SIZE, &rlen)) != 0)
1794: return r;
1795:
1796: if (state->packet_discard) {
1797: if ((r = sshbuf_consume_end(state->input, rlen)) != 0)
1798: return r;
1799: state->keep_alive_timeouts = 0; /* ?? */
1800: if (rlen >= state->packet_discard) {
1801: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1802: return r;
1803: }
1804: state->packet_discard -= rlen;
1805: return 0;
1806: }
1.204 djm 1807: return 0;
1.28 markus 1808: }
1809:
1810: int
1.201 markus 1811: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1812: {
1.201 markus 1813: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1814: }
1815:
1.16 markus 1816: /*
1817: * Sends a diagnostic message from the server to the client. This message
1818: * can be sent at any time (but not while constructing another message). The
1819: * message is printed immediately, but only if the client is being executed
1820: * in verbose mode. These messages are primarily intended to ease debugging
1821: * authentication problems. The length of the formatted message must not
1.205 djm 1822: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1823: */
1.2 provos 1824: void
1.201 markus 1825: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1826: {
1.14 markus 1827: char buf[1024];
1828: va_list args;
1.201 markus 1829: int r;
1.39 markus 1830:
1.249 djm 1831: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1832: return;
1.14 markus 1833:
1834: va_start(args, fmt);
1835: vsnprintf(buf, sizeof(buf), fmt, args);
1836: va_end(args);
1.265 djm 1837:
1838: debug3("sending debug message: %s", buf);
1.14 markus 1839:
1.249 djm 1840: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1841: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1842: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1843: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1844: (r = sshpkt_send(ssh)) != 0 ||
1845: (r = ssh_packet_write_wait(ssh)) != 0)
1.297 djm 1846: fatal_fr(r, "send DEBUG");
1.205 djm 1847: }
1848:
1.268 dtucker 1849: void
1850: sshpkt_fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1.245 djm 1851: {
1852: snprintf(s, l, "%.200s%s%s port %d",
1853: ssh->log_preamble ? ssh->log_preamble : "",
1854: ssh->log_preamble ? " " : "",
1855: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1856: }
1857:
1.205 djm 1858: /*
1859: * Pretty-print connection-terminating errors and exit.
1860: */
1.280 djm 1861: static void
1862: sshpkt_vfatal(struct ssh *ssh, int r, const char *fmt, va_list ap)
1.205 djm 1863: {
1.280 djm 1864: char *tag = NULL, remote_id[512];
1.290 djm 1865: int oerrno = errno;
1.245 djm 1866:
1.268 dtucker 1867: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.245 djm 1868:
1.205 djm 1869: switch (r) {
1870: case SSH_ERR_CONN_CLOSED:
1.257 markus 1871: ssh_packet_clear_keys(ssh);
1.245 djm 1872: logdie("Connection closed by %s", remote_id);
1.205 djm 1873: case SSH_ERR_CONN_TIMEOUT:
1.257 markus 1874: ssh_packet_clear_keys(ssh);
1.245 djm 1875: logdie("Connection %s %s timed out",
1876: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1877: case SSH_ERR_DISCONNECTED:
1.257 markus 1878: ssh_packet_clear_keys(ssh);
1.245 djm 1879: logdie("Disconnected from %s", remote_id);
1.212 djm 1880: case SSH_ERR_SYSTEM_ERROR:
1.257 markus 1881: if (errno == ECONNRESET) {
1882: ssh_packet_clear_keys(ssh);
1.245 djm 1883: logdie("Connection reset by %s", remote_id);
1.257 markus 1884: }
1.213 djm 1885: /* FALLTHROUGH */
1886: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1887: case SSH_ERR_NO_MAC_ALG_MATCH:
1888: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1889: case SSH_ERR_NO_KEX_ALG_MATCH:
1890: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1.310 djm 1891: if (ssh->kex && ssh->kex->failed_choice) {
1.257 markus 1892: ssh_packet_clear_keys(ssh);
1.290 djm 1893: errno = oerrno;
1.245 djm 1894: logdie("Unable to negotiate with %s: %s. "
1895: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1896: ssh->kex->failed_choice);
1.212 djm 1897: }
1898: /* FALLTHROUGH */
1.205 djm 1899: default:
1.280 djm 1900: if (vasprintf(&tag, fmt, ap) == -1) {
1901: ssh_packet_clear_keys(ssh);
1.297 djm 1902: logdie_f("could not allocate failure message");
1.280 djm 1903: }
1.257 markus 1904: ssh_packet_clear_keys(ssh);
1.290 djm 1905: errno = oerrno;
1.297 djm 1906: logdie_r(r, "%s%sConnection %s %s",
1.205 djm 1907: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.297 djm 1908: ssh->state->server_side ? "from" : "to", remote_id);
1.205 djm 1909: }
1.1 deraadt 1910: }
1911:
1.280 djm 1912: void
1913: sshpkt_fatal(struct ssh *ssh, int r, const char *fmt, ...)
1914: {
1915: va_list ap;
1916:
1917: va_start(ap, fmt);
1918: sshpkt_vfatal(ssh, r, fmt, ap);
1919: /* NOTREACHED */
1920: va_end(ap);
1.297 djm 1921: logdie_f("should have exited");
1.280 djm 1922: }
1923:
1.16 markus 1924: /*
1925: * Logs the error plus constructs and sends a disconnect packet, closes the
1926: * connection, and exits. This function never returns. The error message
1927: * should not contain a newline. The length of the formatted message must
1928: * not exceed 1024 bytes.
1929: */
1.2 provos 1930: void
1.201 markus 1931: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1932: {
1.245 djm 1933: char buf[1024], remote_id[512];
1.14 markus 1934: va_list args;
1935: static int disconnecting = 0;
1.201 markus 1936: int r;
1.97 deraadt 1937:
1.14 markus 1938: if (disconnecting) /* Guard against recursive invocations. */
1939: fatal("packet_disconnect called recursively.");
1940: disconnecting = 1;
1941:
1.16 markus 1942: /*
1943: * Format the message. Note that the caller must make sure the
1944: * message is of limited size.
1945: */
1.268 dtucker 1946: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1947: va_start(args, fmt);
1948: vsnprintf(buf, sizeof(buf), fmt, args);
1949: va_end(args);
1950:
1.99 markus 1951: /* Display the error locally */
1.245 djm 1952: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1953:
1.205 djm 1954: /*
1955: * Send the disconnect message to the other side, and wait
1956: * for it to get sent.
1957: */
1958: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1.280 djm 1959: sshpkt_fatal(ssh, r, "%s", __func__);
1.205 djm 1960:
1961: if ((r = ssh_packet_write_wait(ssh)) != 0)
1.280 djm 1962: sshpkt_fatal(ssh, r, "%s", __func__);
1.14 markus 1963:
1964: /* Close the connection. */
1.201 markus 1965: ssh_packet_close(ssh);
1.112 markus 1966: cleanup_exit(255);
1.1 deraadt 1967: }
1968:
1.205 djm 1969: /*
1970: * Checks if there is any buffered output, and tries to write some of
1971: * the output.
1972: */
1973: int
1.201 markus 1974: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1975: {
1.201 markus 1976: struct session_state *state = ssh->state;
1977: int len = sshbuf_len(state->output);
1.222 markus 1978: int r;
1.97 deraadt 1979:
1.14 markus 1980: if (len > 0) {
1.222 markus 1981: len = write(state->connection_out,
1982: sshbuf_ptr(state->output), len);
1.156 djm 1983: if (len == -1) {
1984: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1985: return 0;
1986: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1987: }
1.222 markus 1988: if (len == 0)
1.205 djm 1989: return SSH_ERR_CONN_CLOSED;
1.201 markus 1990: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1991: return r;
1.14 markus 1992: }
1.205 djm 1993: return 0;
1.1 deraadt 1994: }
1995:
1.16 markus 1996: /*
1997: * Calls packet_write_poll repeatedly until all pending output data has been
1998: * written.
1999: */
1.205 djm 2000: int
1.201 markus 2001: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 2002: {
1.205 djm 2003: int ret, r, ms_remain = 0;
1.302 deraadt 2004: struct timeval start;
2005: struct timespec timespec, *timespecp = NULL;
1.201 markus 2006: struct session_state *state = ssh->state;
1.302 deraadt 2007: struct pollfd pfd;
1.56 millert 2008:
1.302 deraadt 2009: if ((r = ssh_packet_write_poll(ssh)) != 0)
1.215 djm 2010: return r;
1.201 markus 2011: while (ssh_packet_have_data_to_write(ssh)) {
1.302 deraadt 2012: pfd.fd = state->connection_out;
2013: pfd.events = POLLOUT;
1.154 dtucker 2014:
1.201 markus 2015: if (state->packet_timeout_ms > 0) {
2016: ms_remain = state->packet_timeout_ms;
1.302 deraadt 2017: timespecp = ×pec;
1.154 dtucker 2018: }
2019: for (;;) {
1.291 markus 2020: if (state->packet_timeout_ms > 0) {
1.302 deraadt 2021: ms_to_timespec(×pec, ms_remain);
1.267 dtucker 2022: monotime_tv(&start);
1.154 dtucker 2023: }
1.302 deraadt 2024: if ((ret = ppoll(&pfd, 1, timespecp, NULL)) >= 0)
1.154 dtucker 2025: break;
1.161 andreas 2026: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 2027: break;
1.291 markus 2028: if (state->packet_timeout_ms <= 0)
1.154 dtucker 2029: continue;
2030: ms_subtract_diff(&start, &ms_remain);
2031: if (ms_remain <= 0) {
2032: ret = 0;
2033: break;
2034: }
2035: }
1.302 deraadt 2036: if (ret == 0)
1.205 djm 2037: return SSH_ERR_CONN_TIMEOUT;
1.302 deraadt 2038: if ((r = ssh_packet_write_poll(ssh)) != 0)
1.205 djm 2039: return r;
1.14 markus 2040: }
1.205 djm 2041: return 0;
1.1 deraadt 2042: }
2043:
2044: /* Returns true if there is buffered data to write to the connection. */
2045:
1.2 provos 2046: int
1.201 markus 2047: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 2048: {
1.201 markus 2049: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 2050: }
2051:
2052: /* Returns true if there is not too much data to write to the connection. */
2053:
1.2 provos 2054: int
1.201 markus 2055: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 2056: {
1.201 markus 2057: if (ssh->state->interactive_mode)
2058: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 2059: else
1.201 markus 2060: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 2061: }
2062:
1.201 markus 2063: void
2064: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 2065: {
1.263 djm 2066: if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
1.101 markus 2067: return;
1.298 djm 2068: set_sock_tos(ssh->state->connection_in, tos);
1.101 markus 2069: }
2070:
1.1 deraadt 2071: /* Informs that the current session is interactive. Sets IP flags for that. */
2072:
1.2 provos 2073: void
1.201 markus 2074: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2075: {
1.201 markus 2076: struct session_state *state = ssh->state;
2077:
2078: if (state->set_interactive_called)
1.43 markus 2079: return;
1.201 markus 2080: state->set_interactive_called = 1;
1.1 deraadt 2081:
1.14 markus 2082: /* Record that we are in interactive mode. */
1.201 markus 2083: state->interactive_mode = interactive;
1.1 deraadt 2084:
1.19 markus 2085: /* Only set socket options if using a socket. */
1.201 markus 2086: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2087: return;
1.201 markus 2088: set_nodelay(state->connection_in);
1.298 djm 2089: ssh_packet_set_tos(ssh, interactive ? qos_interactive : qos_bulk);
1.1 deraadt 2090: }
2091:
2092: /* Returns true if the current connection is interactive. */
2093:
1.2 provos 2094: int
1.201 markus 2095: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2096: {
1.201 markus 2097: return ssh->state->interactive_mode;
1.12 markus 2098: }
2099:
1.113 deraadt 2100: int
1.201 markus 2101: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2102: {
1.201 markus 2103: struct session_state *state = ssh->state;
2104:
2105: if (state->set_maxsize_called) {
1.303 djm 2106: logit_f("called twice: old %d new %d",
1.201 markus 2107: state->max_packet_size, s);
1.14 markus 2108: return -1;
2109: }
2110: if (s < 4 * 1024 || s > 1024 * 1024) {
1.303 djm 2111: logit_f("bad size %d", s);
1.14 markus 2112: return -1;
2113: }
1.201 markus 2114: state->set_maxsize_called = 1;
1.303 djm 2115: debug_f("setting to %d", s);
1.201 markus 2116: state->max_packet_size = s;
1.14 markus 2117: return s;
1.53 markus 2118: }
2119:
1.161 andreas 2120: int
1.201 markus 2121: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2122: {
1.201 markus 2123: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2124: }
2125:
2126: void
1.201 markus 2127: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2128: {
1.201 markus 2129: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2130: }
2131:
2132: u_int
1.201 markus 2133: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2134: {
1.201 markus 2135: return ssh->state->max_packet_size;
1.71 markus 2136: }
2137:
1.105 markus 2138: void
1.244 dtucker 2139: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2140: {
1.244 dtucker 2141: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2142: (unsigned int)seconds);
1.201 markus 2143: ssh->state->rekey_limit = bytes;
2144: ssh->state->rekey_interval = seconds;
1.184 dtucker 2145: }
2146:
2147: time_t
1.201 markus 2148: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2149: {
2150: time_t seconds;
2151:
1.201 markus 2152: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2153: monotime();
1.185 dtucker 2154: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2155: }
2156:
2157: void
1.201 markus 2158: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2159: {
1.201 markus 2160: ssh->state->server_side = 1;
1.278 djm 2161: ssh->kex->server = 1; /* XXX unify? */
1.118 markus 2162: }
2163:
2164: void
1.201 markus 2165: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2166: {
1.201 markus 2167: ssh->state->after_authentication = 1;
1.161 andreas 2168: }
2169:
2170: void *
1.201 markus 2171: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2172: {
1.201 markus 2173: return (void *)ssh->state->input;
1.161 andreas 2174: }
2175:
2176: void *
1.201 markus 2177: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2178: {
1.201 markus 2179: return (void *)ssh->state->output;
1.166 andreas 2180: }
2181:
1.196 markus 2182: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2183: static int
2184: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2185: {
1.239 djm 2186: int r;
1.196 markus 2187:
1.297 djm 2188: debug_f("called");
1.196 markus 2189: /* This was set in net child, but is not visible in user child */
1.201 markus 2190: ssh->state->after_authentication = 1;
2191: ssh->state->rekeying = 0;
1.239 djm 2192: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2193: return r;
1.201 markus 2194: return 0;
2195: }
2196:
2197: /* Packet state (de-)serialization for privsep */
2198:
2199: /* turn kex into a blob for packet state serialization */
2200: static int
2201: kex_to_blob(struct sshbuf *m, struct kex *kex)
2202: {
2203: int r;
2204:
1.299 djm 2205: if ((r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
1.269 djm 2206: (r = sshbuf_put_cstring(m, kex->hostkey_alg)) != 0 ||
1.201 markus 2207: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
1.269 djm 2208: (r = sshbuf_put_u32(m, kex->hostkey_nid)) != 0 ||
1.201 markus 2209: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2210: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2211: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
1.278 djm 2212: (r = sshbuf_put_stringb(m, kex->client_version)) != 0 ||
2213: (r = sshbuf_put_stringb(m, kex->server_version)) != 0 ||
1.299 djm 2214: (r = sshbuf_put_stringb(m, kex->session_id)) != 0 ||
1.278 djm 2215: (r = sshbuf_put_u32(m, kex->flags)) != 0)
1.201 markus 2216: return r;
2217: return 0;
2218: }
2219:
2220: /* turn key exchange results into a blob for packet state serialization */
2221: static int
2222: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2223: {
2224: struct sshbuf *b;
2225: struct sshcipher_ctx *cc;
2226: struct sshcomp *comp;
2227: struct sshenc *enc;
2228: struct sshmac *mac;
2229: struct newkeys *newkey;
2230: int r;
2231:
2232: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2233: return SSH_ERR_INTERNAL_ERROR;
2234: enc = &newkey->enc;
2235: mac = &newkey->mac;
2236: comp = &newkey->comp;
1.235 djm 2237: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2238: ssh->state->receive_context;
1.201 markus 2239: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2240: return r;
2241: if ((b = sshbuf_new()) == NULL)
2242: return SSH_ERR_ALLOC_FAIL;
2243: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2244: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2245: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2246: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2247: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2248: goto out;
2249: if (cipher_authlen(enc->cipher) == 0) {
2250: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2251: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2252: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2253: goto out;
2254: }
2255: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2256: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2257: goto out;
2258: r = sshbuf_put_stringb(m, b);
2259: out:
1.221 mmcc 2260: sshbuf_free(b);
1.201 markus 2261: return r;
2262: }
2263:
2264: /* serialize packet state into a blob */
2265: int
2266: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2267: {
2268: struct session_state *state = ssh->state;
1.249 djm 2269: int r;
1.201 markus 2270:
1.249 djm 2271: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2272: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2273: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2274: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2275: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2276: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2277: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2278: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2279: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2280: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2281: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2282: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2283: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2284: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2285: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 2286: return r;
1.201 markus 2287:
2288: return 0;
2289: }
2290:
2291: /* restore key exchange results from blob for packet state de-serialization */
2292: static int
2293: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2294: {
2295: struct sshbuf *b = NULL;
2296: struct sshcomp *comp;
2297: struct sshenc *enc;
2298: struct sshmac *mac;
2299: struct newkeys *newkey = NULL;
2300: size_t keylen, ivlen, maclen;
2301: int r;
2302:
2303: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2304: r = SSH_ERR_ALLOC_FAIL;
2305: goto out;
2306: }
2307: if ((r = sshbuf_froms(m, &b)) != 0)
2308: goto out;
2309: #ifdef DEBUG_PK
2310: sshbuf_dump(b, stderr);
2311: #endif
2312: enc = &newkey->enc;
2313: mac = &newkey->mac;
2314: comp = &newkey->comp;
2315:
2316: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2317: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2318: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2319: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2320: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2321: goto out;
1.262 djm 2322: if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2323: r = SSH_ERR_INVALID_FORMAT;
2324: goto out;
2325: }
1.201 markus 2326: if (cipher_authlen(enc->cipher) == 0) {
2327: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2328: goto out;
2329: if ((r = mac_setup(mac, mac->name)) != 0)
2330: goto out;
2331: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2332: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2333: goto out;
2334: if (maclen > mac->key_len) {
2335: r = SSH_ERR_INVALID_FORMAT;
2336: goto out;
2337: }
2338: mac->key_len = maclen;
2339: }
2340: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2341: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2342: goto out;
2343: if (sshbuf_len(b) != 0) {
2344: r = SSH_ERR_INVALID_FORMAT;
2345: goto out;
2346: }
2347: enc->key_len = keylen;
2348: enc->iv_len = ivlen;
2349: ssh->kex->newkeys[mode] = newkey;
2350: newkey = NULL;
2351: r = 0;
2352: out:
1.219 mmcc 2353: free(newkey);
1.221 mmcc 2354: sshbuf_free(b);
1.201 markus 2355: return r;
2356: }
2357:
2358: /* restore kex from blob for packet state de-serialization */
2359: static int
2360: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2361: {
2362: struct kex *kex;
2363: int r;
2364:
1.278 djm 2365: if ((kex = kex_new()) == NULL)
2366: return SSH_ERR_ALLOC_FAIL;
1.299 djm 2367: if ((r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
1.269 djm 2368: (r = sshbuf_get_cstring(m, &kex->hostkey_alg, NULL)) != 0 ||
1.201 markus 2369: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
1.269 djm 2370: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_nid)) != 0 ||
1.201 markus 2371: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2372: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2373: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
1.278 djm 2374: (r = sshbuf_get_stringb(m, kex->client_version)) != 0 ||
2375: (r = sshbuf_get_stringb(m, kex->server_version)) != 0 ||
1.299 djm 2376: (r = sshbuf_get_stringb(m, kex->session_id)) != 0 ||
1.278 djm 2377: (r = sshbuf_get_u32(m, &kex->flags)) != 0)
1.201 markus 2378: goto out;
2379: kex->server = 1;
2380: kex->done = 1;
2381: r = 0;
2382: out:
2383: if (r != 0 || kexp == NULL) {
1.278 djm 2384: kex_free(kex);
1.201 markus 2385: if (kexp != NULL)
2386: *kexp = NULL;
2387: } else {
1.278 djm 2388: kex_free(*kexp);
1.201 markus 2389: *kexp = kex;
2390: }
2391: return r;
2392: }
2393:
2394: /*
2395: * Restore packet state from content of blob 'm' (de-serialization).
2396: * Note that 'm' will be partially consumed on parsing or any other errors.
2397: */
2398: int
2399: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2400: {
2401: struct session_state *state = ssh->state;
1.254 djm 2402: const u_char *input, *output;
2403: size_t ilen, olen;
1.201 markus 2404: int r;
2405:
1.249 djm 2406: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2407: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2408: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2409: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2410: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2411: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2412: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2413: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2414: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2415: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2416: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2417: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2418: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2419: return r;
2420: /*
1.296 djm 2421: * We set the time here so that in post-auth privsep child we
1.249 djm 2422: * count from the completion of the authentication.
2423: */
2424: state->rekey_time = monotime();
2425: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2426: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2427: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2428: return r;
1.201 markus 2429:
1.239 djm 2430: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2431: return r;
2432:
2433: sshbuf_reset(state->input);
2434: sshbuf_reset(state->output);
2435: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2436: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2437: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2438: (r = sshbuf_put(state->output, output, olen)) != 0)
2439: return r;
2440:
2441: if (sshbuf_len(m))
2442: return SSH_ERR_INVALID_FORMAT;
1.297 djm 2443: debug3_f("done");
1.201 markus 2444: return 0;
2445: }
2446:
2447: /* NEW API */
2448:
2449: /* put data to the outgoing packet */
2450:
2451: int
2452: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2453: {
2454: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2455: }
2456:
2457: int
2458: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2459: {
2460: return sshbuf_putb(ssh->state->outgoing_packet, b);
2461: }
2462:
2463: int
2464: sshpkt_put_u8(struct ssh *ssh, u_char val)
2465: {
2466: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2467: }
2468:
2469: int
2470: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2471: {
2472: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2473: }
2474:
2475: int
2476: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2477: {
2478: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2479: }
2480:
2481: int
2482: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2483: {
2484: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2485: }
2486:
2487: int
2488: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2489: {
2490: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2491: }
2492:
2493: int
2494: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2495: {
2496: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2497: }
2498:
1.211 djm 2499: #ifdef WITH_OPENSSL
1.201 markus 2500: int
2501: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2502: {
2503: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2504: }
2505:
2506:
2507: int
2508: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2509: {
2510: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2511: }
1.211 djm 2512: #endif /* WITH_OPENSSL */
1.201 markus 2513:
2514: /* fetch data from the incoming packet */
2515:
2516: int
2517: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2518: {
2519: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2520: }
2521:
2522: int
2523: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2524: {
2525: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2526: }
2527:
2528: int
2529: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2530: {
2531: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2532: }
2533:
2534: int
2535: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2536: {
2537: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2538: }
2539:
2540: int
2541: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2542: {
2543: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2544: }
2545:
2546: int
2547: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2548: {
2549: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2550: }
2551:
2552: int
1.264 djm 2553: sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2554: {
2555: return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2556: }
2557:
2558: int
1.201 markus 2559: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2560: {
2561: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
1.282 djm 2562: }
2563:
2564: int
2565: sshpkt_getb_froms(struct ssh *ssh, struct sshbuf **valp)
2566: {
2567: return sshbuf_froms(ssh->state->incoming_packet, valp);
1.201 markus 2568: }
2569:
1.211 djm 2570: #ifdef WITH_OPENSSL
1.201 markus 2571: int
2572: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2573: {
2574: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2575: }
2576:
2577: int
1.281 djm 2578: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM **valp)
1.201 markus 2579: {
1.281 djm 2580: return sshbuf_get_bignum2(ssh->state->incoming_packet, valp);
1.201 markus 2581: }
1.211 djm 2582: #endif /* WITH_OPENSSL */
1.201 markus 2583:
2584: int
2585: sshpkt_get_end(struct ssh *ssh)
2586: {
2587: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2588: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2589: return 0;
2590: }
2591:
2592: const u_char *
2593: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2594: {
2595: if (lenp != NULL)
2596: *lenp = sshbuf_len(ssh->state->incoming_packet);
2597: return sshbuf_ptr(ssh->state->incoming_packet);
2598: }
2599:
2600: /* start a new packet */
2601:
2602: int
2603: sshpkt_start(struct ssh *ssh, u_char type)
2604: {
1.249 djm 2605: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2606:
2607: DBG(debug("packet_start[%d]", type));
1.249 djm 2608: memset(buf, 0, sizeof(buf));
2609: buf[sizeof(buf) - 1] = type;
1.201 markus 2610: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2611: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2612: }
2613:
1.242 markus 2614: static int
2615: ssh_packet_send_mux(struct ssh *ssh)
2616: {
2617: struct session_state *state = ssh->state;
2618: u_char type, *cp;
2619: size_t len;
2620: int r;
2621:
2622: if (ssh->kex)
2623: return SSH_ERR_INTERNAL_ERROR;
2624: len = sshbuf_len(state->outgoing_packet);
2625: if (len < 6)
2626: return SSH_ERR_INTERNAL_ERROR;
2627: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2628: type = cp[5];
2629: if (ssh_packet_log_type(type))
1.297 djm 2630: debug3_f("type %u", type);
1.242 markus 2631: /* drop everything, but the connection protocol */
2632: if (type >= SSH2_MSG_CONNECTION_MIN &&
2633: type <= SSH2_MSG_CONNECTION_MAX) {
2634: POKE_U32(cp, len - 4);
2635: if ((r = sshbuf_putb(state->output,
2636: state->outgoing_packet)) != 0)
2637: return r;
2638: /* sshbuf_dump(state->output, stderr); */
2639: }
2640: sshbuf_reset(state->outgoing_packet);
1.264 djm 2641: return 0;
2642: }
2643:
2644: /*
2645: * 9.2. Ignored Data Message
2646: *
2647: * byte SSH_MSG_IGNORE
2648: * string data
2649: *
2650: * All implementations MUST understand (and ignore) this message at any
2651: * time (after receiving the protocol version). No implementation is
2652: * required to send them. This message can be used as an additional
2653: * protection measure against advanced traffic analysis techniques.
2654: */
2655: int
2656: sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2657: {
2658: u_int32_t rnd = 0;
2659: int r;
2660: u_int i;
2661:
2662: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2663: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2664: return r;
2665: for (i = 0; i < nbytes; i++) {
2666: if (i % 4 == 0)
2667: rnd = arc4random();
2668: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2669: return r;
2670: rnd >>= 8;
2671: }
1.242 markus 2672: return 0;
2673: }
2674:
1.201 markus 2675: /* send it */
2676:
2677: int
2678: sshpkt_send(struct ssh *ssh)
2679: {
1.242 markus 2680: if (ssh->state && ssh->state->mux)
2681: return ssh_packet_send_mux(ssh);
1.249 djm 2682: return ssh_packet_send2(ssh);
1.201 markus 2683: }
2684:
2685: int
2686: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2687: {
2688: char buf[1024];
2689: va_list args;
2690: int r;
2691:
2692: va_start(args, fmt);
2693: vsnprintf(buf, sizeof(buf), fmt, args);
2694: va_end(args);
2695:
1.249 djm 2696: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2697: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2698: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2699: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2700: (r = sshpkt_send(ssh)) != 0)
2701: return r;
1.201 markus 2702: return 0;
2703: }
2704:
2705: /* roundup current message to pad bytes */
2706: int
2707: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2708: {
2709: ssh->state->extra_pad = pad;
2710: return 0;
1.1 deraadt 2711: }