Annotation of src/usr.bin/ssh/packet.c, Revision 1.266
1.266 ! djm 1: /* $OpenBSD: packet.c,v 1.265 2017/10/13 21:13:54 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>
1.142 deraadt 55: #include <signal.h>
1.184 dtucker 56: #include <time.h>
1.1 deraadt 57:
1.201 markus 58: #include <zlib.h>
59:
60: #include "buffer.h" /* typedefs XXX */
61: #include "key.h" /* typedefs XXX */
62:
1.1 deraadt 63: #include "xmalloc.h"
64: #include "crc32.h"
1.25 markus 65: #include "compat.h"
66: #include "ssh2.h"
1.37 markus 67: #include "cipher.h"
1.201 markus 68: #include "sshkey.h"
1.25 markus 69: #include "kex.h"
1.200 markus 70: #include "digest.h"
1.50 markus 71: #include "mac.h"
1.46 markus 72: #include "log.h"
73: #include "canohost.h"
1.87 stevesk 74: #include "misc.h"
1.198 millert 75: #include "channels.h"
1.95 markus 76: #include "ssh.h"
1.201 markus 77: #include "packet.h"
1.197 djm 78: #include "ssherr.h"
1.201 markus 79: #include "sshbuf.h"
1.25 markus 80:
81: #ifdef PACKET_DEBUG
82: #define DBG(x) x
83: #else
84: #define DBG(x)
85: #endif
86:
1.159 markus 87: #define PACKET_MAX_SIZE (256 * 1024)
88:
1.161 andreas 89: struct packet_state {
90: u_int32_t seqnr;
91: u_int32_t packets;
92: u_int64_t blocks;
93: u_int64_t bytes;
94: };
95:
96: struct packet {
97: TAILQ_ENTRY(packet) next;
98: u_char type;
1.201 markus 99: struct sshbuf *payload;
1.161 andreas 100: };
101:
102: struct session_state {
103: /*
104: * This variable contains the file descriptors used for
105: * communicating with the other side. connection_in is used for
106: * reading; connection_out for writing. These can be the same
107: * descriptor, in which case it is assumed to be a socket.
108: */
109: int connection_in;
110: int connection_out;
111:
112: /* Protocol flags for the remote side. */
113: u_int remote_protocol_flags;
1.1 deraadt 114:
1.161 andreas 115: /* Encryption context for receiving data. Only used for decryption. */
1.235 djm 116: struct sshcipher_ctx *receive_context;
1.1 deraadt 117:
1.161 andreas 118: /* Encryption context for sending data. Only used for encryption. */
1.235 djm 119: struct sshcipher_ctx *send_context;
1.14 markus 120:
1.161 andreas 121: /* Buffer for raw input data from the socket. */
1.201 markus 122: struct sshbuf *input;
1.1 deraadt 123:
1.161 andreas 124: /* Buffer for raw output data going to the socket. */
1.201 markus 125: struct sshbuf *output;
1.1 deraadt 126:
1.161 andreas 127: /* Buffer for the partial outgoing packet being constructed. */
1.201 markus 128: struct sshbuf *outgoing_packet;
1.1 deraadt 129:
1.161 andreas 130: /* Buffer for the incoming packet currently being processed. */
1.201 markus 131: struct sshbuf *incoming_packet;
1.1 deraadt 132:
1.161 andreas 133: /* Scratch buffer for packet compression/decompression. */
1.201 markus 134: struct sshbuf *compression_buffer;
135:
136: /* Incoming/outgoing compression dictionaries */
137: z_stream compression_in_stream;
138: z_stream compression_out_stream;
139: int compression_in_started;
140: int compression_out_started;
141: int compression_in_failures;
142: int compression_out_failures;
1.1 deraadt 143:
1.161 andreas 144: /*
145: * Flag indicating whether packet compression/decompression is
146: * enabled.
147: */
148: int packet_compression;
1.1 deraadt 149:
1.161 andreas 150: /* default maximum packet size */
151: u_int max_packet_size;
1.1 deraadt 152:
1.161 andreas 153: /* Flag indicating whether this module has been initialized. */
154: int initialized;
1.12 markus 155:
1.161 andreas 156: /* Set to true if the connection is interactive. */
157: int interactive_mode;
1.1 deraadt 158:
1.161 andreas 159: /* Set to true if we are the server side. */
160: int server_side;
1.1 deraadt 161:
1.161 andreas 162: /* Set to true if we are authenticated. */
163: int after_authentication;
1.118 markus 164:
1.161 andreas 165: int keep_alive_timeouts;
1.118 markus 166:
1.161 andreas 167: /* The maximum time that we will wait to send or receive a packet */
168: int packet_timeout_ms;
1.151 dtucker 169:
1.161 andreas 170: /* Session key information for Encryption and MAC */
1.201 markus 171: struct newkeys *newkeys[MODE_MAX];
1.161 andreas 172: struct packet_state p_read, p_send;
1.154 dtucker 173:
1.184 dtucker 174: /* Volume-based rekeying */
1.224 dtucker 175: u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
1.105 markus 176:
1.184 dtucker 177: /* Time-based rekeying */
1.208 markus 178: u_int32_t rekey_interval; /* how often in seconds */
1.184 dtucker 179: time_t rekey_time; /* time of last rekeying */
180:
1.161 andreas 181: /* roundup current message to extra_pad bytes */
182: u_char extra_pad;
1.95 markus 183:
1.161 andreas 184: /* XXX discard incoming data after MAC error */
185: u_int packet_discard;
1.234 markus 186: size_t packet_discard_mac_already;
1.201 markus 187: struct sshmac *packet_discard_mac;
1.71 markus 188:
1.161 andreas 189: /* Used in packet_read_poll2() */
190: u_int packlen;
1.159 markus 191:
1.165 andreas 192: /* Used in packet_send2 */
193: int rekeying;
194:
1.242 markus 195: /* Used in ssh_packet_send_mux() */
196: int mux;
197:
1.165 andreas 198: /* Used in packet_set_interactive */
199: int set_interactive_called;
200:
201: /* Used in packet_set_maxsize */
202: int set_maxsize_called;
203:
1.201 markus 204: /* One-off warning about weak ciphers */
205: int cipher_warning_done;
206:
1.243 djm 207: /* Hook for fuzzing inbound packets */
208: ssh_packet_hook_fn *hook_in;
209: void *hook_in_ctx;
210:
1.161 andreas 211: TAILQ_HEAD(, packet) outgoing;
1.105 markus 212: };
1.161 andreas 213:
1.201 markus 214: struct ssh *
215: ssh_alloc_session_state(void)
1.161 andreas 216: {
1.201 markus 217: struct ssh *ssh = NULL;
218: struct session_state *state = NULL;
1.161 andreas 219:
1.201 markus 220: if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
221: (state = calloc(1, sizeof(*state))) == NULL ||
222: (state->input = sshbuf_new()) == NULL ||
223: (state->output = sshbuf_new()) == NULL ||
224: (state->outgoing_packet = sshbuf_new()) == NULL ||
225: (state->incoming_packet = sshbuf_new()) == NULL)
226: goto fail;
227: TAILQ_INIT(&state->outgoing);
1.202 markus 228: TAILQ_INIT(&ssh->private_keys);
229: TAILQ_INIT(&ssh->public_keys);
1.201 markus 230: state->connection_in = -1;
231: state->connection_out = -1;
232: state->max_packet_size = 32768;
233: state->packet_timeout_ms = -1;
234: state->p_send.packets = state->p_read.packets = 0;
235: state->initialized = 1;
236: /*
237: * ssh_packet_send2() needs to queue packets until
238: * we've done the initial key exchange.
239: */
240: state->rekeying = 1;
241: ssh->state = state;
242: return ssh;
243: fail:
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: free(ssh);
252: return NULL;
1.161 andreas 253: }
1.105 markus 254:
1.243 djm 255: void
256: ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
257: {
258: ssh->state->hook_in = hook;
259: ssh->state->hook_in_ctx = ctx;
260: }
261:
1.228 djm 262: /* Returns nonzero if rekeying is in progress */
263: int
264: ssh_packet_is_rekeying(struct ssh *ssh)
265: {
1.249 djm 266: return ssh->state->rekeying ||
267: (ssh->kex != NULL && ssh->kex->done == 0);
1.228 djm 268: }
269:
1.16 markus 270: /*
1.253 naddy 271: * Sets the descriptors used for communication.
1.16 markus 272: */
1.201 markus 273: struct ssh *
274: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1 deraadt 275: {
1.201 markus 276: struct session_state *state;
277: const struct sshcipher *none = cipher_by_name("none");
1.197 djm 278: int r;
1.97 deraadt 279:
1.205 djm 280: if (none == NULL) {
281: error("%s: cannot load cipher 'none'", __func__);
282: return NULL;
283: }
1.201 markus 284: if (ssh == NULL)
285: ssh = ssh_alloc_session_state();
1.205 djm 286: if (ssh == NULL) {
287: error("%s: cound not allocate state", __func__);
288: return NULL;
289: }
1.201 markus 290: state = ssh->state;
291: state->connection_in = fd_in;
292: state->connection_out = fd_out;
293: if ((r = cipher_init(&state->send_context, none,
1.197 djm 294: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201 markus 295: (r = cipher_init(&state->receive_context, none,
1.205 djm 296: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
297: error("%s: cipher_init failed: %s", __func__, ssh_err(r));
1.230 djm 298: free(ssh); /* XXX need ssh_free_session_state? */
1.205 djm 299: return NULL;
300: }
1.201 markus 301: state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
1.207 djm 302: /*
303: * Cache the IP address of the remote connection for use in error
304: * messages that might be generated after the connection has closed.
305: */
306: (void)ssh_remote_ipaddr(ssh);
1.201 markus 307: return ssh;
1.1 deraadt 308: }
309:
1.154 dtucker 310: void
1.201 markus 311: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 312: {
1.201 markus 313: struct session_state *state = ssh->state;
314:
1.174 djm 315: if (timeout <= 0 || count <= 0) {
1.201 markus 316: state->packet_timeout_ms = -1;
1.154 dtucker 317: return;
318: }
319: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 320: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 321: else
1.201 markus 322: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 323: }
324:
1.242 markus 325: void
326: ssh_packet_set_mux(struct ssh *ssh)
327: {
328: ssh->state->mux = 1;
329: ssh->state->rekeying = 0;
330: }
331:
332: int
333: ssh_packet_get_mux(struct ssh *ssh)
334: {
335: return ssh->state->mux;
336: }
337:
1.201 markus 338: int
1.245 djm 339: ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
340: {
341: va_list args;
342: int r;
343:
344: free(ssh->log_preamble);
345: if (fmt == NULL)
346: ssh->log_preamble = NULL;
347: else {
348: va_start(args, fmt);
349: r = vasprintf(&ssh->log_preamble, fmt, args);
350: va_end(args);
351: if (r < 0 || ssh->log_preamble == NULL)
352: return SSH_ERR_ALLOC_FAIL;
353: }
354: return 0;
355: }
356:
357: int
1.201 markus 358: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 359: {
1.201 markus 360: struct session_state *state = ssh->state;
361: int r;
362:
363: if (state->packet_discard_mac) {
1.159 markus 364: char buf[1024];
1.234 markus 365: size_t dlen = PACKET_MAX_SIZE;
1.201 markus 366:
1.234 markus 367: if (dlen > state->packet_discard_mac_already)
368: dlen -= state->packet_discard_mac_already;
1.159 markus 369: memset(buf, 'a', sizeof(buf));
1.234 markus 370: while (sshbuf_len(state->incoming_packet) < dlen)
1.201 markus 371: if ((r = sshbuf_put(state->incoming_packet, buf,
372: sizeof(buf))) != 0)
373: return r;
374: (void) mac_compute(state->packet_discard_mac,
375: state->p_read.seqnr,
1.234 markus 376: sshbuf_ptr(state->incoming_packet), dlen,
1.201 markus 377: NULL, 0);
1.159 markus 378: }
1.220 djm 379: logit("Finished discarding for %.200s port %d",
380: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 381: return SSH_ERR_MAC_INVALID;
1.159 markus 382: }
383:
1.201 markus 384: static int
385: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
1.234 markus 386: struct sshmac *mac, size_t mac_already, u_int discard)
1.159 markus 387: {
1.201 markus 388: struct session_state *state = ssh->state;
389: int r;
390:
391: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
392: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
393: return r;
394: return SSH_ERR_MAC_INVALID;
395: }
1.234 markus 396: /*
397: * Record number of bytes over which the mac has already
398: * been computed in order to minimize timing attacks.
399: */
400: if (mac && mac->enabled) {
1.201 markus 401: state->packet_discard_mac = mac;
1.234 markus 402: state->packet_discard_mac_already = mac_already;
403: }
404: if (sshbuf_len(state->input) >= discard)
405: return ssh_packet_stop_discard(ssh);
1.201 markus 406: state->packet_discard = discard - sshbuf_len(state->input);
407: return 0;
1.159 markus 408: }
409:
1.19 markus 410: /* Returns 1 if remote host is connected via socket, 0 if not. */
411:
412: int
1.201 markus 413: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 414: {
1.201 markus 415: struct session_state *state = ssh->state;
1.19 markus 416: struct sockaddr_storage from, to;
417: socklen_t fromlen, tolen;
418:
1.230 djm 419: if (state->connection_in == -1 || state->connection_out == -1)
420: return 0;
421:
1.19 markus 422: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 423: if (state->connection_in == state->connection_out)
1.19 markus 424: return 1;
425: fromlen = sizeof(from);
426: memset(&from, 0, sizeof(from));
1.201 markus 427: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.161 andreas 428: &fromlen) < 0)
1.19 markus 429: return 0;
430: tolen = sizeof(to);
431: memset(&to, 0, sizeof(to));
1.201 markus 432: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.161 andreas 433: &tolen) < 0)
1.19 markus 434: return 0;
435: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
436: return 0;
437: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
438: return 0;
439: return 1;
440: }
441:
1.91 markus 442: void
1.201 markus 443: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 444: {
1.201 markus 445: if (ibytes)
446: *ibytes = ssh->state->p_read.bytes;
447: if (obytes)
448: *obytes = ssh->state->p_send.bytes;
1.91 markus 449: }
1.125 deraadt 450:
1.91 markus 451: int
1.201 markus 452: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 453: {
454: struct sockaddr_storage to;
1.21 deraadt 455: socklen_t tolen = sizeof(to);
1.19 markus 456:
457: memset(&to, 0, sizeof(to));
1.201 markus 458: if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
1.161 andreas 459: &tolen) < 0)
1.19 markus 460: return 0;
1.173 djm 461: return to.ss_family;
1.19 markus 462: }
463:
1.1 deraadt 464: /* Sets the connection into non-blocking mode. */
465:
1.2 provos 466: void
1.201 markus 467: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 468: {
1.14 markus 469: /* Set the socket into non-blocking mode. */
1.201 markus 470: set_nonblock(ssh->state->connection_in);
1.14 markus 471:
1.201 markus 472: if (ssh->state->connection_out != ssh->state->connection_in)
473: set_nonblock(ssh->state->connection_out);
1.1 deraadt 474: }
475:
476: /* Returns the socket used for reading. */
477:
1.2 provos 478: int
1.201 markus 479: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 480: {
1.201 markus 481: return ssh->state->connection_in;
1.1 deraadt 482: }
483:
484: /* Returns the descriptor used for writing. */
485:
1.2 provos 486: int
1.201 markus 487: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 488: {
1.201 markus 489: return ssh->state->connection_out;
490: }
491:
492: /*
493: * Returns the IP-address of the remote host as a string. The returned
494: * string must not be freed.
495: */
496:
497: const char *
498: ssh_remote_ipaddr(struct ssh *ssh)
499: {
1.220 djm 500: const int sock = ssh->state->connection_in;
501:
1.201 markus 502: /* Check whether we have cached the ipaddr. */
1.220 djm 503: if (ssh->remote_ipaddr == NULL) {
504: if (ssh_packet_connection_is_on_socket(ssh)) {
505: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 djm 506: ssh->remote_port = get_peer_port(sock);
507: ssh->local_ipaddr = get_local_ipaddr(sock);
508: ssh->local_port = get_local_port(sock);
1.220 djm 509: } else {
510: ssh->remote_ipaddr = strdup("UNKNOWN");
1.230 djm 511: ssh->remote_port = 65535;
512: ssh->local_ipaddr = strdup("UNKNOWN");
513: ssh->local_port = 65535;
1.220 djm 514: }
515: }
1.201 markus 516: return ssh->remote_ipaddr;
1.1 deraadt 517: }
518:
1.220 djm 519: /* Returns the port number of the remote host. */
520:
521: int
522: ssh_remote_port(struct ssh *ssh)
523: {
524: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
525: return ssh->remote_port;
1.230 djm 526: }
527:
528: /*
529: * Returns the IP-address of the local host as a string. The returned
530: * string must not be freed.
531: */
532:
533: const char *
534: ssh_local_ipaddr(struct ssh *ssh)
535: {
536: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
537: return ssh->local_ipaddr;
538: }
539:
540: /* Returns the port number of the local host. */
541:
542: int
543: ssh_local_port(struct ssh *ssh)
544: {
545: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
546: return ssh->local_port;
1.266 ! djm 547: }
! 548:
! 549: /* Returns the routing domain of the input socket, or NULL if unavailable */
! 550: const char *
! 551: ssh_packet_rdomain_in(struct ssh *ssh)
! 552: {
! 553: if (ssh->rdomain_in != NULL)
! 554: return ssh->rdomain_in;
! 555: if (!ssh_packet_connection_is_on_socket(ssh))
! 556: return NULL;
! 557: ssh->rdomain_in = get_rdomain(ssh->state->connection_in);
! 558: return ssh->rdomain_in;
1.220 djm 559: }
560:
1.1 deraadt 561: /* Closes the connection and clears and frees internal data structures. */
562:
1.257 markus 563: static void
564: ssh_packet_close_internal(struct ssh *ssh, int do_close)
1.1 deraadt 565: {
1.201 markus 566: struct session_state *state = ssh->state;
567: u_int mode;
568:
569: if (!state->initialized)
1.14 markus 570: return;
1.201 markus 571: state->initialized = 0;
1.257 markus 572: if (do_close) {
573: if (state->connection_in == state->connection_out) {
574: close(state->connection_out);
575: } else {
576: close(state->connection_in);
577: close(state->connection_out);
578: }
1.14 markus 579: }
1.201 markus 580: sshbuf_free(state->input);
581: sshbuf_free(state->output);
582: sshbuf_free(state->outgoing_packet);
583: sshbuf_free(state->incoming_packet);
1.257 markus 584: for (mode = 0; mode < MODE_MAX; mode++) {
585: kex_free_newkeys(state->newkeys[mode]); /* current keys */
586: state->newkeys[mode] = NULL;
587: ssh_clear_newkeys(ssh, mode); /* next keys */
588: }
589: /* comression state is in shared mem, so we can only release it once */
590: if (do_close && state->compression_buffer) {
1.201 markus 591: sshbuf_free(state->compression_buffer);
592: if (state->compression_out_started) {
593: z_streamp stream = &state->compression_out_stream;
594: debug("compress outgoing: "
595: "raw data %llu, compressed %llu, factor %.2f",
596: (unsigned long long)stream->total_in,
597: (unsigned long long)stream->total_out,
598: stream->total_in == 0 ? 0.0 :
599: (double) stream->total_out / stream->total_in);
600: if (state->compression_out_failures == 0)
601: deflateEnd(stream);
602: }
603: if (state->compression_in_started) {
1.260 dtucker 604: z_streamp stream = &state->compression_in_stream;
1.201 markus 605: debug("compress incoming: "
606: "raw data %llu, compressed %llu, factor %.2f",
607: (unsigned long long)stream->total_out,
608: (unsigned long long)stream->total_in,
609: stream->total_out == 0 ? 0.0 :
610: (double) stream->total_in / stream->total_out);
611: if (state->compression_in_failures == 0)
612: inflateEnd(stream);
613: }
1.14 markus 614: }
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) {
619: free(ssh->remote_ipaddr);
620: ssh->remote_ipaddr = NULL;
621: free(ssh->state);
622: ssh->state = NULL;
623: }
624: }
625:
626: void
627: ssh_packet_close(struct ssh *ssh)
628: {
629: ssh_packet_close_internal(ssh, 1);
630: }
631:
632: void
633: ssh_packet_clear_keys(struct ssh *ssh)
634: {
635: ssh_packet_close_internal(ssh, 0);
1.1 deraadt 636: }
637:
638: /* Sets remote side protocol flags. */
639:
1.2 provos 640: void
1.201 markus 641: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 642: {
1.201 markus 643: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 644: }
645:
646: /* Returns the remote protocol flags set earlier by the above function. */
647:
1.40 markus 648: u_int
1.201 markus 649: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 650: {
1.201 markus 651: return ssh->state->remote_protocol_flags;
1.1 deraadt 652: }
653:
1.16 markus 654: /*
655: * Starts packet compression from the next packet on in both directions.
656: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
657: */
1.1 deraadt 658:
1.201 markus 659: static int
660: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 661: {
1.201 markus 662: if (!ssh->state->compression_buffer &&
663: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
664: return SSH_ERR_ALLOC_FAIL;
665: return 0;
1.60 markus 666: }
667:
1.201 markus 668: static int
669: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 670: {
1.201 markus 671: if (level < 1 || level > 9)
672: return SSH_ERR_INVALID_ARGUMENT;
673: debug("Enabling compression at level %d.", level);
674: if (ssh->state->compression_out_started == 1)
675: deflateEnd(&ssh->state->compression_out_stream);
676: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
677: case Z_OK:
678: ssh->state->compression_out_started = 1;
679: break;
680: case Z_MEM_ERROR:
681: return SSH_ERR_ALLOC_FAIL;
682: default:
683: return SSH_ERR_INTERNAL_ERROR;
684: }
685: return 0;
1.1 deraadt 686: }
687:
1.201 markus 688: static int
689: start_compression_in(struct ssh *ssh)
690: {
691: if (ssh->state->compression_in_started == 1)
692: inflateEnd(&ssh->state->compression_in_stream);
693: switch (inflateInit(&ssh->state->compression_in_stream)) {
694: case Z_OK:
695: ssh->state->compression_in_started = 1;
696: break;
697: case Z_MEM_ERROR:
698: return SSH_ERR_ALLOC_FAIL;
699: default:
700: return SSH_ERR_INTERNAL_ERROR;
701: }
702: return 0;
703: }
1.95 markus 704:
1.201 markus 705: int
706: ssh_packet_start_compression(struct ssh *ssh, int level)
1.1 deraadt 707: {
1.197 djm 708: int r;
1.97 deraadt 709:
1.249 djm 710: if (ssh->state->packet_compression)
1.201 markus 711: return SSH_ERR_INTERNAL_ERROR;
712: ssh->state->packet_compression = 1;
713: if ((r = ssh_packet_init_compression(ssh)) != 0 ||
714: (r = start_compression_in(ssh)) != 0 ||
715: (r = start_compression_out(ssh, level)) != 0)
716: return r;
717: return 0;
1.95 markus 718: }
719:
1.201 markus 720: /* XXX remove need for separate compression buffer */
721: static int
722: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 723: {
1.201 markus 724: u_char buf[4096];
725: int r, status;
726:
727: if (ssh->state->compression_out_started != 1)
728: return SSH_ERR_INTERNAL_ERROR;
729:
730: /* This case is not handled below. */
731: if (sshbuf_len(in) == 0)
732: return 0;
733:
734: /* Input is the contents of the input buffer. */
735: if ((ssh->state->compression_out_stream.next_in =
736: sshbuf_mutable_ptr(in)) == NULL)
737: return SSH_ERR_INTERNAL_ERROR;
738: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
739:
740: /* Loop compressing until deflate() returns with avail_out != 0. */
741: do {
742: /* Set up fixed-size output buffer. */
743: ssh->state->compression_out_stream.next_out = buf;
744: ssh->state->compression_out_stream.avail_out = sizeof(buf);
745:
746: /* Compress as much data into the buffer as possible. */
747: status = deflate(&ssh->state->compression_out_stream,
748: Z_PARTIAL_FLUSH);
749: switch (status) {
750: case Z_MEM_ERROR:
751: return SSH_ERR_ALLOC_FAIL;
752: case Z_OK:
753: /* Append compressed data to output_buffer. */
754: if ((r = sshbuf_put(out, buf, sizeof(buf) -
755: ssh->state->compression_out_stream.avail_out)) != 0)
756: return r;
757: break;
758: case Z_STREAM_ERROR:
759: default:
760: ssh->state->compression_out_failures++;
761: return SSH_ERR_INVALID_FORMAT;
762: }
763: } while (ssh->state->compression_out_stream.avail_out == 0);
764: return 0;
1.1 deraadt 765: }
766:
1.201 markus 767: static int
768: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 769: {
1.201 markus 770: u_char buf[4096];
771: int r, status;
1.1 deraadt 772:
1.201 markus 773: if (ssh->state->compression_in_started != 1)
774: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 775:
1.201 markus 776: if ((ssh->state->compression_in_stream.next_in =
777: sshbuf_mutable_ptr(in)) == NULL)
778: return SSH_ERR_INTERNAL_ERROR;
779: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 780:
1.201 markus 781: for (;;) {
782: /* Set up fixed-size output buffer. */
783: ssh->state->compression_in_stream.next_out = buf;
784: ssh->state->compression_in_stream.avail_out = sizeof(buf);
785:
786: status = inflate(&ssh->state->compression_in_stream,
787: Z_PARTIAL_FLUSH);
788: switch (status) {
789: case Z_OK:
790: if ((r = sshbuf_put(out, buf, sizeof(buf) -
791: ssh->state->compression_in_stream.avail_out)) != 0)
792: return r;
793: break;
794: case Z_BUF_ERROR:
795: /*
796: * Comments in zlib.h say that we should keep calling
797: * inflate() until we get an error. This appears to
798: * be the error that we get.
799: */
800: return 0;
801: case Z_DATA_ERROR:
802: return SSH_ERR_INVALID_FORMAT;
803: case Z_MEM_ERROR:
804: return SSH_ERR_ALLOC_FAIL;
805: case Z_STREAM_ERROR:
806: default:
807: ssh->state->compression_in_failures++;
808: return SSH_ERR_INTERNAL_ERROR;
809: }
810: }
811: /* NOTREACHED */
1.170 djm 812: }
813:
1.257 markus 814: void
815: ssh_clear_newkeys(struct ssh *ssh, int mode)
816: {
1.259 djm 817: if (ssh->kex && ssh->kex->newkeys[mode]) {
1.257 markus 818: kex_free_newkeys(ssh->kex->newkeys[mode]);
819: ssh->kex->newkeys[mode] = NULL;
820: }
821: }
822:
1.201 markus 823: int
824: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 825: {
1.201 markus 826: struct session_state *state = ssh->state;
827: struct sshenc *enc;
828: struct sshmac *mac;
829: struct sshcomp *comp;
1.235 djm 830: struct sshcipher_ctx **ccp;
1.236 markus 831: struct packet_state *ps;
1.105 markus 832: u_int64_t *max_blocks;
1.259 djm 833: const char *wmsg;
1.197 djm 834: int r, crypt_type;
1.57 markus 835:
1.100 markus 836: debug2("set_newkeys: mode %d", mode);
1.57 markus 837:
1.88 markus 838: if (mode == MODE_OUT) {
1.235 djm 839: ccp = &state->send_context;
1.115 avsm 840: crypt_type = CIPHER_ENCRYPT;
1.236 markus 841: ps = &state->p_send;
1.201 markus 842: max_blocks = &state->max_blocks_out;
1.88 markus 843: } else {
1.235 djm 844: ccp = &state->receive_context;
1.115 avsm 845: crypt_type = CIPHER_DECRYPT;
1.236 markus 846: ps = &state->p_read;
1.201 markus 847: max_blocks = &state->max_blocks_in;
1.88 markus 848: }
1.201 markus 849: if (state->newkeys[mode] != NULL) {
1.257 markus 850: debug("set_newkeys: rekeying, input %llu bytes %llu blocks, "
851: "output %llu bytes %llu blocks",
852: (unsigned long long)state->p_read.bytes,
853: (unsigned long long)state->p_read.blocks,
854: (unsigned long long)state->p_send.bytes,
855: (unsigned long long)state->p_send.blocks);
1.235 djm 856: cipher_free(*ccp);
857: *ccp = NULL;
1.257 markus 858: kex_free_newkeys(state->newkeys[mode]);
859: state->newkeys[mode] = NULL;
1.57 markus 860: }
1.236 markus 861: /* note that both bytes and the seqnr are not reset */
862: ps->packets = ps->blocks = 0;
1.201 markus 863: /* move newkeys from kex to state */
864: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
865: return SSH_ERR_INTERNAL_ERROR;
866: ssh->kex->newkeys[mode] = NULL;
867: enc = &state->newkeys[mode]->enc;
868: mac = &state->newkeys[mode]->mac;
869: comp = &state->newkeys[mode]->comp;
870: if (cipher_authlen(enc->cipher) == 0) {
871: if ((r = mac_init(mac)) != 0)
872: return r;
873: }
874: mac->enabled = 1;
1.57 markus 875: DBG(debug("cipher_init_context: %d", mode));
1.235 djm 876: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 877: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 878: return r;
879: if (!state->cipher_warning_done &&
1.235 djm 880: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 881: error("Warning: %s", wmsg);
882: state->cipher_warning_done = 1;
883: }
1.91 markus 884: /* Deleting the keys does not gain extra security */
1.192 djm 885: /* explicit_bzero(enc->iv, enc->block_size);
886: explicit_bzero(enc->key, enc->key_len);
887: explicit_bzero(mac->key, mac->key_len); */
1.241 djm 888: if ((comp->type == COMP_ZLIB ||
889: (comp->type == COMP_DELAYED &&
890: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 891: if ((r = ssh_packet_init_compression(ssh)) < 0)
892: return r;
893: if (mode == MODE_OUT) {
894: if ((r = start_compression_out(ssh, 6)) != 0)
895: return r;
896: } else {
897: if ((r = start_compression_in(ssh)) != 0)
898: return r;
899: }
1.57 markus 900: comp->enabled = 1;
901: }
1.109 markus 902: /*
903: * The 2^(blocksize*2) limit is too expensive for 3DES,
1.254 djm 904: * so enforce a 1GB limit for small blocksizes.
1.261 dtucker 905: * See RFC4344 section 3.2.
1.109 markus 906: */
907: if (enc->block_size >= 16)
908: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
909: else
910: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 911: if (state->rekey_limit)
1.237 deraadt 912: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 913: state->rekey_limit / enc->block_size);
1.227 djm 914: debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1.201 markus 915: return 0;
1.57 markus 916: }
917:
1.228 djm 918: #define MAX_PACKETS (1U<<31)
919: static int
920: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
921: {
922: struct session_state *state = ssh->state;
923: u_int32_t out_blocks;
924:
925: /* XXX client can't cope with rekeying pre-auth */
926: if (!state->after_authentication)
927: return 0;
928:
929: /* Haven't keyed yet or KEX in progress. */
930: if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
931: return 0;
932:
933: /* Peer can't rekey */
934: if (ssh->compat & SSH_BUG_NOREKEY)
935: return 0;
936:
937: /*
938: * Permit one packet in or out per rekey - this allows us to
939: * make progress when rekey limits are very small.
940: */
941: if (state->p_send.packets == 0 && state->p_read.packets == 0)
942: return 0;
943:
944: /* Time-based rekeying */
945: if (state->rekey_interval != 0 &&
1.244 dtucker 946: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 947: return 1;
948:
1.261 dtucker 949: /*
950: * Always rekey when MAX_PACKETS sent in either direction
951: * As per RFC4344 section 3.1 we do this after 2^31 packets.
952: */
1.228 djm 953: if (state->p_send.packets > MAX_PACKETS ||
954: state->p_read.packets > MAX_PACKETS)
955: return 1;
956:
957: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 958: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 959: state->newkeys[MODE_OUT]->enc.block_size);
960: return (state->max_blocks_out &&
961: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
962: (state->max_blocks_in &&
963: (state->p_read.blocks > state->max_blocks_in));
964: }
965:
1.16 markus 966: /*
1.118 markus 967: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 968: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 969: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
970: */
1.201 markus 971: static int
972: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 973: {
1.201 markus 974: struct session_state *state = ssh->state;
975: struct sshcomp *comp = NULL;
976: int r, mode;
1.118 markus 977:
978: /*
979: * Remember that we are past the authentication step, so rekeying
980: * with COMP_DELAYED will turn on compression immediately.
981: */
1.201 markus 982: state->after_authentication = 1;
1.118 markus 983: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 984: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 985: if (state->newkeys[mode] == NULL)
1.145 markus 986: continue;
1.201 markus 987: comp = &state->newkeys[mode]->comp;
1.118 markus 988: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 989: if ((r = ssh_packet_init_compression(ssh)) != 0)
990: return r;
991: if (mode == MODE_OUT) {
992: if ((r = start_compression_out(ssh, 6)) != 0)
993: return r;
994: } else {
995: if ((r = start_compression_in(ssh)) != 0)
996: return r;
997: }
1.118 markus 998: comp->enabled = 1;
999: }
1000: }
1.201 markus 1001: return 0;
1.118 markus 1002: }
1003:
1.226 djm 1004: /* Used to mute debug logging for noisy packet types */
1.242 markus 1005: int
1.226 djm 1006: ssh_packet_log_type(u_char type)
1007: {
1008: switch (type) {
1009: case SSH2_MSG_CHANNEL_DATA:
1010: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1011: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1012: return 0;
1013: default:
1014: return 1;
1015: }
1016: }
1017:
1.118 markus 1018: /*
1.25 markus 1019: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1020: */
1.201 markus 1021: int
1022: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1023: {
1.201 markus 1024: struct session_state *state = ssh->state;
1.200 markus 1025: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1026: u_char tmp, padlen, pad = 0;
1.201 markus 1027: u_int authlen = 0, aadlen = 0;
1028: u_int len;
1029: struct sshenc *enc = NULL;
1030: struct sshmac *mac = NULL;
1031: struct sshcomp *comp = NULL;
1032: int r, block_size;
1033:
1034: if (state->newkeys[MODE_OUT] != NULL) {
1035: enc = &state->newkeys[MODE_OUT]->enc;
1036: mac = &state->newkeys[MODE_OUT]->mac;
1037: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1038: /* disable mac for authenticated encryption */
1039: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1040: mac = NULL;
1.25 markus 1041: }
1.88 markus 1042: block_size = enc ? enc->block_size : 8;
1.180 markus 1043: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1044:
1.201 markus 1045: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1046: if (ssh_packet_log_type(type))
1047: debug3("send packet: type %u", type);
1.25 markus 1048: #ifdef PACKET_DEBUG
1049: fprintf(stderr, "plain: ");
1.201 markus 1050: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1051: #endif
1052:
1053: if (comp && comp->enabled) {
1.201 markus 1054: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1055: /* skip header, compress only payload */
1.201 markus 1056: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1057: goto out;
1058: sshbuf_reset(state->compression_buffer);
1059: if ((r = compress_buffer(ssh, state->outgoing_packet,
1060: state->compression_buffer)) != 0)
1061: goto out;
1062: sshbuf_reset(state->outgoing_packet);
1063: if ((r = sshbuf_put(state->outgoing_packet,
1064: "\0\0\0\0\0", 5)) != 0 ||
1065: (r = sshbuf_putb(state->outgoing_packet,
1066: state->compression_buffer)) != 0)
1067: goto out;
1068: DBG(debug("compression: raw %d compressed %zd", len,
1069: sshbuf_len(state->outgoing_packet)));
1.25 markus 1070: }
1071:
1072: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1073: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1074:
1075: /*
1076: * calc size of padding, alloc space, get random data,
1077: * minimum padding is 4 bytes
1078: */
1.178 markus 1079: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1080: padlen = block_size - (len % block_size);
1081: if (padlen < 4)
1082: padlen += block_size;
1.201 markus 1083: if (state->extra_pad) {
1.233 djm 1084: tmp = state->extra_pad;
1.201 markus 1085: state->extra_pad =
1.237 deraadt 1086: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1087: /* check if roundup overflowed */
1088: if (state->extra_pad < tmp)
1089: return SSH_ERR_INVALID_ARGUMENT;
1090: tmp = (len + padlen) % state->extra_pad;
1091: /* Check whether pad calculation below will underflow */
1092: if (tmp > state->extra_pad)
1093: return SSH_ERR_INVALID_ARGUMENT;
1094: pad = state->extra_pad - tmp;
1.193 djm 1095: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1096: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1097: tmp = padlen;
1.71 markus 1098: padlen += pad;
1.233 djm 1099: /* Check whether padlen calculation overflowed */
1100: if (padlen < tmp)
1101: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1102: state->extra_pad = 0;
1.71 markus 1103: }
1.201 markus 1104: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1105: goto out;
1.235 djm 1106: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1107: /* random padding */
1.201 markus 1108: arc4random_buf(cp, padlen);
1.32 markus 1109: } else {
1110: /* clear padding */
1.192 djm 1111: explicit_bzero(cp, padlen);
1.25 markus 1112: }
1.178 markus 1113: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1114: len = sshbuf_len(state->outgoing_packet);
1115: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1116: if (cp == NULL) {
1117: r = SSH_ERR_INTERNAL_ERROR;
1118: goto out;
1119: }
1.25 markus 1120: /* packet_length includes payload, padding and padding length field */
1.201 markus 1121: POKE_U32(cp, len - 4);
1.89 markus 1122: cp[4] = padlen;
1.178 markus 1123: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1124: len, padlen, aadlen));
1.25 markus 1125:
1126: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1127: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1128: if ((r = mac_compute(mac, state->p_send.seqnr,
1129: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1130: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1131: goto out;
1132: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1133: }
1134: /* encrypt packet and append to output buffer. */
1.201 markus 1135: if ((r = sshbuf_reserve(state->output,
1136: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1137: goto out;
1.235 djm 1138: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1139: sshbuf_ptr(state->outgoing_packet),
1140: len - aadlen, aadlen, authlen)) != 0)
1141: goto out;
1.25 markus 1142: /* append unencrypted MAC */
1.178 markus 1143: if (mac && mac->enabled) {
1144: if (mac->etm) {
1145: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1146: if ((r = mac_compute(mac, state->p_send.seqnr,
1147: cp, len, macbuf, sizeof(macbuf))) != 0)
1148: goto out;
1.178 markus 1149: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1150: state->p_send.seqnr));
1.178 markus 1151: }
1.201 markus 1152: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1153: goto out;
1.178 markus 1154: }
1.25 markus 1155: #ifdef PACKET_DEBUG
1156: fprintf(stderr, "encrypted: ");
1.201 markus 1157: sshbuf_dump(state->output, stderr);
1.25 markus 1158: #endif
1.29 markus 1159: /* increment sequence number for outgoing packets */
1.201 markus 1160: if (++state->p_send.seqnr == 0)
1.106 itojun 1161: logit("outgoing seqnr wraps around");
1.201 markus 1162: if (++state->p_send.packets == 0)
1163: if (!(ssh->compat & SSH_BUG_NOREKEY))
1164: return SSH_ERR_NEED_REKEY;
1165: state->p_send.blocks += len / block_size;
1166: state->p_send.bytes += len;
1167: sshbuf_reset(state->outgoing_packet);
1.25 markus 1168:
1.57 markus 1169: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1170: r = ssh_set_newkeys(ssh, MODE_OUT);
1171: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1172: r = ssh_packet_enable_delayed_compress(ssh);
1173: else
1174: r = 0;
1175: out:
1176: return r;
1.25 markus 1177: }
1178:
1.228 djm 1179: /* returns non-zero if the specified packet type is usec by KEX */
1180: static int
1181: ssh_packet_type_is_kex(u_char type)
1182: {
1183: return
1184: type >= SSH2_MSG_TRANSPORT_MIN &&
1185: type <= SSH2_MSG_TRANSPORT_MAX &&
1186: type != SSH2_MSG_SERVICE_REQUEST &&
1187: type != SSH2_MSG_SERVICE_ACCEPT &&
1188: type != SSH2_MSG_EXT_INFO;
1189: }
1190:
1.201 markus 1191: int
1192: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1193: {
1.201 markus 1194: struct session_state *state = ssh->state;
1.105 markus 1195: struct packet *p;
1.201 markus 1196: u_char type;
1.228 djm 1197: int r, need_rekey;
1.105 markus 1198:
1.228 djm 1199: if (sshbuf_len(state->outgoing_packet) < 6)
1200: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1201: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1202: need_rekey = !ssh_packet_type_is_kex(type) &&
1203: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1204:
1.228 djm 1205: /*
1206: * During rekeying we can only send key exchange messages.
1207: * Queue everything else.
1208: */
1209: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1210: if (need_rekey)
1211: debug3("%s: rekex triggered", __func__);
1212: debug("enqueue packet: %u", type);
1213: p = calloc(1, sizeof(*p));
1214: if (p == NULL)
1215: return SSH_ERR_ALLOC_FAIL;
1216: p->type = type;
1217: p->payload = state->outgoing_packet;
1218: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1219: state->outgoing_packet = sshbuf_new();
1220: if (state->outgoing_packet == NULL)
1221: return SSH_ERR_ALLOC_FAIL;
1222: if (need_rekey) {
1223: /*
1224: * This packet triggered a rekey, so send the
1225: * KEXINIT now.
1226: * NB. reenters this function via kex_start_rekex().
1227: */
1228: return kex_start_rekex(ssh);
1.105 markus 1229: }
1.228 djm 1230: return 0;
1.105 markus 1231: }
1232:
1233: /* rekeying starts with sending KEXINIT */
1234: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1235: state->rekeying = 1;
1.105 markus 1236:
1.201 markus 1237: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1238: return r;
1.105 markus 1239:
1240: /* after a NEWKEYS message we can send the complete queue */
1241: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1242: state->rekeying = 0;
1243: state->rekey_time = monotime();
1244: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1245: type = p->type;
1.228 djm 1246: /*
1247: * If this packet triggers a rekex, then skip the
1248: * remaining packets in the queue for now.
1249: * NB. re-enters this function via kex_start_rekex.
1250: */
1251: if (ssh_packet_need_rekeying(ssh,
1252: sshbuf_len(p->payload))) {
1253: debug3("%s: queued packet triggered rekex",
1254: __func__);
1255: return kex_start_rekex(ssh);
1256: }
1.105 markus 1257: debug("dequeue packet: %u", type);
1.201 markus 1258: sshbuf_free(state->outgoing_packet);
1259: state->outgoing_packet = p->payload;
1260: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1261: memset(p, 0, sizeof(*p));
1.186 djm 1262: free(p);
1.201 markus 1263: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1264: return r;
1.105 markus 1265: }
1266: }
1.201 markus 1267: return 0;
1.25 markus 1268: }
1269:
1270: /*
1.16 markus 1271: * Waits until a packet has been received, and returns its type. Note that
1272: * no other data is processed until this returns, so this function should not
1273: * be used during the interactive session.
1274: */
1.1 deraadt 1275:
1.2 provos 1276: int
1.201 markus 1277: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1278: {
1.201 markus 1279: struct session_state *state = ssh->state;
1.222 markus 1280: int len, r, ms_remain;
1.56 millert 1281: fd_set *setp;
1.14 markus 1282: char buf[8192];
1.155 deraadt 1283: struct timeval timeout, start, *timeoutp = NULL;
1284:
1.25 markus 1285: DBG(debug("packet_read()"));
1.14 markus 1286:
1.214 deraadt 1287: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1288: NFDBITS), sizeof(fd_mask));
1.201 markus 1289: if (setp == NULL)
1290: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1291:
1.205 djm 1292: /*
1293: * Since we are blocking, ensure that all written packets have
1294: * been sent.
1295: */
1.210 markus 1296: if ((r = ssh_packet_write_wait(ssh)) != 0)
1297: goto out;
1.14 markus 1298:
1299: /* Stay in the loop until we have received a complete packet. */
1300: for (;;) {
1301: /* Try to read a packet from the buffer. */
1.201 markus 1302: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1303: if (r != 0)
1304: break;
1.14 markus 1305: /* If we got a packet, return it. */
1.201 markus 1306: if (*typep != SSH_MSG_NONE)
1307: break;
1.16 markus 1308: /*
1309: * Otherwise, wait for some data to arrive, add it to the
1310: * buffer, and try again.
1311: */
1.201 markus 1312: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1313: NFDBITS) * sizeof(fd_mask));
1.201 markus 1314: FD_SET(state->connection_in, setp);
1.16 markus 1315:
1.201 markus 1316: if (state->packet_timeout_ms > 0) {
1317: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1318: timeoutp = &timeout;
1319: }
1.14 markus 1320: /* Wait for some data to arrive. */
1.154 dtucker 1321: for (;;) {
1.201 markus 1322: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1323: ms_to_timeval(&timeout, ms_remain);
1324: gettimeofday(&start, NULL);
1325: }
1.201 markus 1326: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1327: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1328: break;
1.161 andreas 1329: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1330: break;
1.201 markus 1331: if (state->packet_timeout_ms == -1)
1.154 dtucker 1332: continue;
1333: ms_subtract_diff(&start, &ms_remain);
1334: if (ms_remain <= 0) {
1.201 markus 1335: r = 0;
1.154 dtucker 1336: break;
1337: }
1338: }
1.246 djm 1339: if (r == 0) {
1340: r = SSH_ERR_CONN_TIMEOUT;
1341: goto out;
1342: }
1.14 markus 1343: /* Read data from the socket. */
1.222 markus 1344: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1345: if (len == 0) {
1346: r = SSH_ERR_CONN_CLOSED;
1347: goto out;
1348: }
1349: if (len < 0) {
1350: r = SSH_ERR_SYSTEM_ERROR;
1351: goto out;
1352: }
1.204 djm 1353:
1.14 markus 1354: /* Append it to the buffer. */
1.204 djm 1355: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1356: goto out;
1.14 markus 1357: }
1.210 markus 1358: out:
1.201 markus 1359: free(setp);
1360: return r;
1.1 deraadt 1361: }
1362:
1.77 djm 1363: int
1.201 markus 1364: ssh_packet_read(struct ssh *ssh)
1.77 djm 1365: {
1.201 markus 1366: u_char type;
1367: int r;
1368:
1369: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1370: fatal("%s: %s", __func__, ssh_err(r));
1371: return type;
1.77 djm 1372: }
1373:
1.16 markus 1374: /*
1375: * Waits until a packet has been received, verifies that its type matches
1376: * that given, and gives a fatal error and exits if there is a mismatch.
1377: */
1.1 deraadt 1378:
1.205 djm 1379: int
1380: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1381: {
1.205 djm 1382: int r;
1383: u_char type;
1.1 deraadt 1384:
1.205 djm 1385: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1386: return r;
1387: if (type != expected_type) {
1388: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1389: "Protocol error: expected packet type %d, got %d",
1.205 djm 1390: expected_type, type)) != 0)
1391: return r;
1392: return SSH_ERR_PROTOCOL_ERROR;
1393: }
1394: return 0;
1.1 deraadt 1395: }
1.14 markus 1396:
1.242 markus 1397: static int
1398: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1399: {
1400: struct session_state *state = ssh->state;
1401: const u_char *cp;
1402: size_t need;
1403: int r;
1404:
1405: if (ssh->kex)
1406: return SSH_ERR_INTERNAL_ERROR;
1407: *typep = SSH_MSG_NONE;
1408: cp = sshbuf_ptr(state->input);
1409: if (state->packlen == 0) {
1410: if (sshbuf_len(state->input) < 4 + 1)
1411: return 0; /* packet is incomplete */
1412: state->packlen = PEEK_U32(cp);
1413: if (state->packlen < 4 + 1 ||
1414: state->packlen > PACKET_MAX_SIZE)
1415: return SSH_ERR_MESSAGE_INCOMPLETE;
1416: }
1417: need = state->packlen + 4;
1418: if (sshbuf_len(state->input) < need)
1419: return 0; /* packet is incomplete */
1420: sshbuf_reset(state->incoming_packet);
1421: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1422: state->packlen)) != 0 ||
1423: (r = sshbuf_consume(state->input, need)) != 0 ||
1424: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1425: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1426: return r;
1427: if (ssh_packet_log_type(*typep))
1428: debug3("%s: type %u", __func__, *typep);
1429: /* sshbuf_dump(state->incoming_packet, stderr); */
1430: /* reset for next packet */
1431: state->packlen = 0;
1432: return r;
1433: }
1434:
1.201 markus 1435: int
1436: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1437: {
1.201 markus 1438: struct session_state *state = ssh->state;
1.40 markus 1439: u_int padlen, need;
1.231 djm 1440: u_char *cp;
1.201 markus 1441: u_int maclen, aadlen = 0, authlen = 0, block_size;
1442: struct sshenc *enc = NULL;
1443: struct sshmac *mac = NULL;
1444: struct sshcomp *comp = NULL;
1.200 markus 1445: int r;
1.201 markus 1446:
1.242 markus 1447: if (state->mux)
1448: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1449:
1.201 markus 1450: *typep = SSH_MSG_NONE;
1451:
1452: if (state->packet_discard)
1453: return 0;
1454:
1455: if (state->newkeys[MODE_IN] != NULL) {
1456: enc = &state->newkeys[MODE_IN]->enc;
1457: mac = &state->newkeys[MODE_IN]->mac;
1458: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1459: /* disable mac for authenticated encryption */
1460: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1461: mac = NULL;
1.25 markus 1462: }
1463: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1464: block_size = enc ? enc->block_size : 8;
1.180 markus 1465: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1466:
1.201 markus 1467: if (aadlen && state->packlen == 0) {
1.235 djm 1468: if (cipher_get_length(state->receive_context,
1.201 markus 1469: &state->packlen, state->p_read.seqnr,
1470: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1471: return 0;
1472: if (state->packlen < 1 + 4 ||
1473: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1474: #ifdef PACKET_DEBUG
1.201 markus 1475: sshbuf_dump(state->input, stderr);
1.178 markus 1476: #endif
1.201 markus 1477: logit("Bad packet length %u.", state->packlen);
1478: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1479: return r;
1.217 djm 1480: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1481: }
1.201 markus 1482: sshbuf_reset(state->incoming_packet);
1483: } else if (state->packlen == 0) {
1.25 markus 1484: /*
1485: * check if input size is less than the cipher block size,
1486: * decrypt first block and extract length of incoming packet
1487: */
1.201 markus 1488: if (sshbuf_len(state->input) < block_size)
1489: return 0;
1490: sshbuf_reset(state->incoming_packet);
1491: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1492: &cp)) != 0)
1493: goto out;
1.235 djm 1494: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1495: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1496: block_size, 0, 0)) != 0)
1497: goto out;
1498: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1499: if (state->packlen < 1 + 4 ||
1500: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1501: #ifdef PACKET_DEBUG
1.201 markus 1502: fprintf(stderr, "input: \n");
1503: sshbuf_dump(state->input, stderr);
1504: fprintf(stderr, "incoming_packet: \n");
1505: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1506: #endif
1.201 markus 1507: logit("Bad packet length %u.", state->packlen);
1.234 markus 1508: return ssh_packet_start_discard(ssh, enc, mac, 0,
1509: PACKET_MAX_SIZE);
1.25 markus 1510: }
1.201 markus 1511: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1512: goto out;
1.25 markus 1513: }
1.201 markus 1514: DBG(debug("input: packet len %u", state->packlen+4));
1515:
1.178 markus 1516: if (aadlen) {
1517: /* only the payload is encrypted */
1.201 markus 1518: need = state->packlen;
1.178 markus 1519: } else {
1520: /*
1521: * the payload size and the payload are encrypted, but we
1522: * have a partial packet of block_size bytes
1523: */
1.201 markus 1524: need = 4 + state->packlen - block_size;
1.178 markus 1525: }
1.180 markus 1526: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1527: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1528: if (need % block_size != 0) {
1529: logit("padding error: need %d block %d mod %d",
1.25 markus 1530: need, block_size, need % block_size);
1.234 markus 1531: return ssh_packet_start_discard(ssh, enc, mac, 0,
1532: PACKET_MAX_SIZE - block_size);
1.158 markus 1533: }
1.25 markus 1534: /*
1535: * check if the entire packet has been received and
1.178 markus 1536: * decrypt into incoming_packet:
1537: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1538: * 'need' bytes are encrypted, followed by either
1539: * 'authlen' bytes of authentication tag or
1.178 markus 1540: * 'maclen' bytes of message authentication code.
1.25 markus 1541: */
1.201 markus 1542: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1543: return 0; /* packet is incomplete */
1.25 markus 1544: #ifdef PACKET_DEBUG
1545: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1546: sshbuf_dump(state->input, stderr);
1.25 markus 1547: #endif
1.231 djm 1548: /* EtM: check mac over encrypted input */
1.201 markus 1549: if (mac && mac->enabled && mac->etm) {
1.231 djm 1550: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1551: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1552: sshbuf_ptr(state->input) + aadlen + need + authlen,
1553: maclen)) != 0) {
1554: if (r == SSH_ERR_MAC_INVALID)
1555: logit("Corrupted MAC on input.");
1.201 markus 1556: goto out;
1.231 djm 1557: }
1.201 markus 1558: }
1559: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1560: &cp)) != 0)
1561: goto out;
1.235 djm 1562: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1563: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1564: goto out;
1565: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1566: goto out;
1.29 markus 1567: if (mac && mac->enabled) {
1.231 djm 1568: /* Not EtM: check MAC over cleartext */
1569: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1570: sshbuf_ptr(state->incoming_packet),
1571: sshbuf_len(state->incoming_packet),
1572: sshbuf_ptr(state->input), maclen)) != 0) {
1573: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1574: goto out;
1.159 markus 1575: logit("Corrupted MAC on input.");
1.247 markus 1576: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1577: return SSH_ERR_INTERNAL_ERROR;
1578: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1579: sshbuf_len(state->incoming_packet),
1.247 markus 1580: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1581: }
1.231 djm 1582: /* Remove MAC from input buffer */
1.201 markus 1583: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1584: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1585: goto out;
1.25 markus 1586: }
1.77 djm 1587: if (seqnr_p != NULL)
1.201 markus 1588: *seqnr_p = state->p_read.seqnr;
1589: if (++state->p_read.seqnr == 0)
1.106 itojun 1590: logit("incoming seqnr wraps around");
1.201 markus 1591: if (++state->p_read.packets == 0)
1592: if (!(ssh->compat & SSH_BUG_NOREKEY))
1593: return SSH_ERR_NEED_REKEY;
1594: state->p_read.blocks += (state->packlen + 4) / block_size;
1595: state->p_read.bytes += state->packlen + 4;
1.25 markus 1596:
1597: /* get padlen */
1.201 markus 1598: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1599: DBG(debug("input: padlen %d", padlen));
1.205 djm 1600: if (padlen < 4) {
1601: if ((r = sshpkt_disconnect(ssh,
1602: "Corrupted padlen %d on input.", padlen)) != 0 ||
1603: (r = ssh_packet_write_wait(ssh)) != 0)
1604: return r;
1605: return SSH_ERR_CONN_CORRUPT;
1606: }
1.25 markus 1607:
1608: /* skip packet size + padlen, discard padding */
1.201 markus 1609: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1610: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1611: goto out;
1.25 markus 1612:
1.201 markus 1613: DBG(debug("input: len before de-compress %zd",
1614: sshbuf_len(state->incoming_packet)));
1.25 markus 1615: if (comp && comp->enabled) {
1.201 markus 1616: sshbuf_reset(state->compression_buffer);
1617: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1618: state->compression_buffer)) != 0)
1619: goto out;
1620: sshbuf_reset(state->incoming_packet);
1621: if ((r = sshbuf_putb(state->incoming_packet,
1622: state->compression_buffer)) != 0)
1623: goto out;
1624: DBG(debug("input: len after de-compress %zd",
1625: sshbuf_len(state->incoming_packet)));
1.25 markus 1626: }
1627: /*
1628: * get packet type, implies consume.
1629: * return length of payload (without type field)
1630: */
1.201 markus 1631: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1632: goto out;
1.226 djm 1633: if (ssh_packet_log_type(*typep))
1634: debug3("receive packet: type %u", *typep);
1.205 djm 1635: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1636: if ((r = sshpkt_disconnect(ssh,
1637: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1638: (r = ssh_packet_write_wait(ssh)) != 0)
1639: return r;
1640: return SSH_ERR_PROTOCOL_ERROR;
1641: }
1.243 djm 1642: if (state->hook_in != NULL &&
1643: (r = state->hook_in(ssh, state->incoming_packet, typep,
1644: state->hook_in_ctx)) != 0)
1645: return r;
1.238 markus 1646: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1647: r = ssh_packet_enable_delayed_compress(ssh);
1648: else
1649: r = 0;
1.25 markus 1650: #ifdef PACKET_DEBUG
1.201 markus 1651: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1652: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1653: #endif
1.62 markus 1654: /* reset for next packet */
1.201 markus 1655: state->packlen = 0;
1.228 djm 1656:
1657: /* do we need to rekey? */
1658: if (ssh_packet_need_rekeying(ssh, 0)) {
1659: debug3("%s: rekex triggered", __func__);
1660: if ((r = kex_start_rekex(ssh)) != 0)
1661: return r;
1662: }
1.201 markus 1663: out:
1664: return r;
1.25 markus 1665: }
1666:
1667: int
1.201 markus 1668: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1669: {
1.201 markus 1670: struct session_state *state = ssh->state;
1.96 deraadt 1671: u_int reason, seqnr;
1.201 markus 1672: int r;
1673: u_char *msg;
1.62 markus 1674:
1.25 markus 1675: for (;;) {
1.201 markus 1676: msg = NULL;
1.249 djm 1677: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1678: if (r != 0)
1679: return r;
1680: if (*typep) {
1681: state->keep_alive_timeouts = 0;
1682: DBG(debug("received packet type %d", *typep));
1683: }
1684: switch (*typep) {
1685: case SSH2_MSG_IGNORE:
1686: debug3("Received SSH2_MSG_IGNORE");
1687: break;
1688: case SSH2_MSG_DEBUG:
1689: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1690: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1691: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1692: free(msg);
1.201 markus 1693: return r;
1.48 stevesk 1694: }
1.249 djm 1695: debug("Remote: %.900s", msg);
1696: free(msg);
1697: break;
1698: case SSH2_MSG_DISCONNECT:
1699: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1700: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1701: return r;
1702: /* Ignore normal client exit notifications */
1703: do_log2(ssh->state->server_side &&
1704: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1705: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1706: "Received disconnect from %s port %d:"
1707: "%u: %.400s", ssh_remote_ipaddr(ssh),
1708: ssh_remote_port(ssh), reason, msg);
1709: free(msg);
1710: return SSH_ERR_DISCONNECTED;
1711: case SSH2_MSG_UNIMPLEMENTED:
1712: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1713: return r;
1714: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1715: seqnr);
1716: break;
1717: default:
1718: return 0;
1.25 markus 1719: }
1720: }
1721: }
1722:
1.16 markus 1723: /*
1724: * Buffers the given amount of input characters. This is intended to be used
1725: * together with packet_read_poll.
1726: */
1.1 deraadt 1727:
1.204 djm 1728: int
1.201 markus 1729: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1730: {
1.201 markus 1731: struct session_state *state = ssh->state;
1732: int r;
1733:
1734: if (state->packet_discard) {
1735: state->keep_alive_timeouts = 0; /* ?? */
1736: if (len >= state->packet_discard) {
1737: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1738: return r;
1.201 markus 1739: }
1740: state->packet_discard -= len;
1.204 djm 1741: return 0;
1.159 markus 1742: }
1.201 markus 1743: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1744: return r;
1745:
1746: return 0;
1.28 markus 1747: }
1748:
1749: int
1.201 markus 1750: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1751: {
1.201 markus 1752: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1753: }
1754:
1.16 markus 1755: /*
1756: * Sends a diagnostic message from the server to the client. This message
1757: * can be sent at any time (but not while constructing another message). The
1758: * message is printed immediately, but only if the client is being executed
1759: * in verbose mode. These messages are primarily intended to ease debugging
1760: * authentication problems. The length of the formatted message must not
1.205 djm 1761: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1762: */
1.2 provos 1763: void
1.201 markus 1764: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1765: {
1.14 markus 1766: char buf[1024];
1767: va_list args;
1.201 markus 1768: int r;
1.39 markus 1769:
1.249 djm 1770: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1771: return;
1.14 markus 1772:
1773: va_start(args, fmt);
1774: vsnprintf(buf, sizeof(buf), fmt, args);
1775: va_end(args);
1.265 djm 1776:
1777: debug3("sending debug message: %s", buf);
1.14 markus 1778:
1.249 djm 1779: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1780: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1781: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1782: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1783: (r = sshpkt_send(ssh)) != 0 ||
1784: (r = ssh_packet_write_wait(ssh)) != 0)
1.205 djm 1785: fatal("%s: %s", __func__, ssh_err(r));
1786: }
1787:
1.245 djm 1788: static void
1789: fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1790: {
1791: snprintf(s, l, "%.200s%s%s port %d",
1792: ssh->log_preamble ? ssh->log_preamble : "",
1793: ssh->log_preamble ? " " : "",
1794: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1795: }
1796:
1.205 djm 1797: /*
1798: * Pretty-print connection-terminating errors and exit.
1799: */
1800: void
1801: sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
1802: {
1.245 djm 1803: char remote_id[512];
1804:
1805: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1806:
1.205 djm 1807: switch (r) {
1808: case SSH_ERR_CONN_CLOSED:
1.257 markus 1809: ssh_packet_clear_keys(ssh);
1.245 djm 1810: logdie("Connection closed by %s", remote_id);
1.205 djm 1811: case SSH_ERR_CONN_TIMEOUT:
1.257 markus 1812: ssh_packet_clear_keys(ssh);
1.245 djm 1813: logdie("Connection %s %s timed out",
1814: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1815: case SSH_ERR_DISCONNECTED:
1.257 markus 1816: ssh_packet_clear_keys(ssh);
1.245 djm 1817: logdie("Disconnected from %s", remote_id);
1.212 djm 1818: case SSH_ERR_SYSTEM_ERROR:
1.257 markus 1819: if (errno == ECONNRESET) {
1820: ssh_packet_clear_keys(ssh);
1.245 djm 1821: logdie("Connection reset by %s", remote_id);
1.257 markus 1822: }
1.213 djm 1823: /* FALLTHROUGH */
1824: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1825: case SSH_ERR_NO_MAC_ALG_MATCH:
1826: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1827: case SSH_ERR_NO_KEX_ALG_MATCH:
1828: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1829: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.257 markus 1830: ssh_packet_clear_keys(ssh);
1.245 djm 1831: logdie("Unable to negotiate with %s: %s. "
1832: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1833: ssh->kex->failed_choice);
1.212 djm 1834: }
1835: /* FALLTHROUGH */
1.205 djm 1836: default:
1.257 markus 1837: ssh_packet_clear_keys(ssh);
1.245 djm 1838: logdie("%s%sConnection %s %s: %s",
1.205 djm 1839: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 1840: ssh->state->server_side ? "from" : "to",
1.245 djm 1841: remote_id, ssh_err(r));
1.205 djm 1842: }
1.1 deraadt 1843: }
1844:
1.16 markus 1845: /*
1846: * Logs the error plus constructs and sends a disconnect packet, closes the
1847: * connection, and exits. This function never returns. The error message
1848: * should not contain a newline. The length of the formatted message must
1849: * not exceed 1024 bytes.
1850: */
1.2 provos 1851: void
1.201 markus 1852: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1853: {
1.245 djm 1854: char buf[1024], remote_id[512];
1.14 markus 1855: va_list args;
1856: static int disconnecting = 0;
1.201 markus 1857: int r;
1.97 deraadt 1858:
1.14 markus 1859: if (disconnecting) /* Guard against recursive invocations. */
1860: fatal("packet_disconnect called recursively.");
1861: disconnecting = 1;
1862:
1.16 markus 1863: /*
1864: * Format the message. Note that the caller must make sure the
1865: * message is of limited size.
1866: */
1.245 djm 1867: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1868: va_start(args, fmt);
1869: vsnprintf(buf, sizeof(buf), fmt, args);
1870: va_end(args);
1871:
1.99 markus 1872: /* Display the error locally */
1.245 djm 1873: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1874:
1.205 djm 1875: /*
1876: * Send the disconnect message to the other side, and wait
1877: * for it to get sent.
1878: */
1879: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1880: sshpkt_fatal(ssh, __func__, r);
1881:
1882: if ((r = ssh_packet_write_wait(ssh)) != 0)
1883: sshpkt_fatal(ssh, __func__, r);
1.14 markus 1884:
1885: /* Close the connection. */
1.201 markus 1886: ssh_packet_close(ssh);
1.112 markus 1887: cleanup_exit(255);
1.1 deraadt 1888: }
1889:
1.205 djm 1890: /*
1891: * Checks if there is any buffered output, and tries to write some of
1892: * the output.
1893: */
1894: int
1.201 markus 1895: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1896: {
1.201 markus 1897: struct session_state *state = ssh->state;
1898: int len = sshbuf_len(state->output);
1.222 markus 1899: int r;
1.97 deraadt 1900:
1.14 markus 1901: if (len > 0) {
1.222 markus 1902: len = write(state->connection_out,
1903: sshbuf_ptr(state->output), len);
1.156 djm 1904: if (len == -1) {
1905: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1906: return 0;
1907: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1908: }
1.222 markus 1909: if (len == 0)
1.205 djm 1910: return SSH_ERR_CONN_CLOSED;
1.201 markus 1911: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1912: return r;
1.14 markus 1913: }
1.205 djm 1914: return 0;
1.1 deraadt 1915: }
1916:
1.16 markus 1917: /*
1918: * Calls packet_write_poll repeatedly until all pending output data has been
1919: * written.
1920: */
1.205 djm 1921: int
1.201 markus 1922: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1923: {
1.56 millert 1924: fd_set *setp;
1.205 djm 1925: int ret, r, ms_remain = 0;
1.154 dtucker 1926: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1927: struct session_state *state = ssh->state;
1.56 millert 1928:
1.214 deraadt 1929: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1930: NFDBITS), sizeof(fd_mask));
1.201 markus 1931: if (setp == NULL)
1.205 djm 1932: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1933: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1934: free(setp);
1.215 djm 1935: return r;
1.216 gsoares 1936: }
1.201 markus 1937: while (ssh_packet_have_data_to_write(ssh)) {
1938: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1939: NFDBITS) * sizeof(fd_mask));
1.201 markus 1940: FD_SET(state->connection_out, setp);
1.154 dtucker 1941:
1.201 markus 1942: if (state->packet_timeout_ms > 0) {
1943: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1944: timeoutp = &timeout;
1945: }
1946: for (;;) {
1.201 markus 1947: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1948: ms_to_timeval(&timeout, ms_remain);
1949: gettimeofday(&start, NULL);
1950: }
1.201 markus 1951: if ((ret = select(state->connection_out + 1,
1.161 andreas 1952: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1953: break;
1.161 andreas 1954: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1955: break;
1.201 markus 1956: if (state->packet_timeout_ms == -1)
1.154 dtucker 1957: continue;
1958: ms_subtract_diff(&start, &ms_remain);
1959: if (ms_remain <= 0) {
1960: ret = 0;
1961: break;
1962: }
1963: }
1964: if (ret == 0) {
1.205 djm 1965: free(setp);
1966: return SSH_ERR_CONN_TIMEOUT;
1967: }
1968: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1969: free(setp);
1970: return r;
1.154 dtucker 1971: }
1.14 markus 1972: }
1.186 djm 1973: free(setp);
1.205 djm 1974: return 0;
1.1 deraadt 1975: }
1976:
1977: /* Returns true if there is buffered data to write to the connection. */
1978:
1.2 provos 1979: int
1.201 markus 1980: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 1981: {
1.201 markus 1982: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 1983: }
1984:
1985: /* Returns true if there is not too much data to write to the connection. */
1986:
1.2 provos 1987: int
1.201 markus 1988: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 1989: {
1.201 markus 1990: if (ssh->state->interactive_mode)
1991: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 1992: else
1.201 markus 1993: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 1994: }
1995:
1.201 markus 1996: void
1997: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 1998: {
1.263 djm 1999: if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
1.101 markus 2000: return;
1.201 markus 2001: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 2002: case AF_INET:
2003: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 2004: if (setsockopt(ssh->state->connection_in,
1.173 djm 2005: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
2006: error("setsockopt IP_TOS %d: %.100s:",
2007: tos, strerror(errno));
2008: break;
2009: case AF_INET6:
2010: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 2011: if (setsockopt(ssh->state->connection_in,
1.173 djm 2012: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2013: error("setsockopt IPV6_TCLASS %d: %.100s:",
2014: tos, strerror(errno));
2015: break;
2016: }
1.101 markus 2017: }
2018:
1.1 deraadt 2019: /* Informs that the current session is interactive. Sets IP flags for that. */
2020:
1.2 provos 2021: void
1.201 markus 2022: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2023: {
1.201 markus 2024: struct session_state *state = ssh->state;
2025:
2026: if (state->set_interactive_called)
1.43 markus 2027: return;
1.201 markus 2028: state->set_interactive_called = 1;
1.1 deraadt 2029:
1.14 markus 2030: /* Record that we are in interactive mode. */
1.201 markus 2031: state->interactive_mode = interactive;
1.1 deraadt 2032:
1.19 markus 2033: /* Only set socket options if using a socket. */
1.201 markus 2034: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2035: return;
1.201 markus 2036: set_nodelay(state->connection_in);
2037: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2038: qos_bulk);
1.1 deraadt 2039: }
2040:
2041: /* Returns true if the current connection is interactive. */
2042:
1.2 provos 2043: int
1.201 markus 2044: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2045: {
1.201 markus 2046: return ssh->state->interactive_mode;
1.12 markus 2047: }
2048:
1.113 deraadt 2049: int
1.201 markus 2050: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2051: {
1.201 markus 2052: struct session_state *state = ssh->state;
2053:
2054: if (state->set_maxsize_called) {
1.106 itojun 2055: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2056: state->max_packet_size, s);
1.14 markus 2057: return -1;
2058: }
2059: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2060: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2061: return -1;
2062: }
1.201 markus 2063: state->set_maxsize_called = 1;
1.66 markus 2064: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2065: state->max_packet_size = s;
1.14 markus 2066: return s;
1.53 markus 2067: }
2068:
1.161 andreas 2069: int
1.201 markus 2070: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2071: {
1.201 markus 2072: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2073: }
2074:
2075: void
1.201 markus 2076: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2077: {
1.201 markus 2078: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2079: }
2080:
2081: u_int
1.201 markus 2082: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2083: {
1.201 markus 2084: return ssh->state->max_packet_size;
1.71 markus 2085: }
2086:
1.105 markus 2087: void
1.244 dtucker 2088: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2089: {
1.244 dtucker 2090: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2091: (unsigned int)seconds);
1.201 markus 2092: ssh->state->rekey_limit = bytes;
2093: ssh->state->rekey_interval = seconds;
1.184 dtucker 2094: }
2095:
2096: time_t
1.201 markus 2097: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2098: {
2099: time_t seconds;
2100:
1.201 markus 2101: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2102: monotime();
1.185 dtucker 2103: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2104: }
2105:
2106: void
1.201 markus 2107: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2108: {
1.201 markus 2109: ssh->state->server_side = 1;
1.118 markus 2110: }
2111:
2112: void
1.201 markus 2113: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2114: {
1.201 markus 2115: ssh->state->after_authentication = 1;
1.161 andreas 2116: }
2117:
2118: void *
1.201 markus 2119: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2120: {
1.201 markus 2121: return (void *)ssh->state->input;
1.161 andreas 2122: }
2123:
2124: void *
1.201 markus 2125: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2126: {
1.201 markus 2127: return (void *)ssh->state->output;
1.166 andreas 2128: }
2129:
1.196 markus 2130: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2131: static int
2132: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2133: {
1.239 djm 2134: int r;
1.196 markus 2135:
2136: debug("%s: called", __func__);
2137: /* This was set in net child, but is not visible in user child */
1.201 markus 2138: ssh->state->after_authentication = 1;
2139: ssh->state->rekeying = 0;
1.239 djm 2140: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2141: return r;
1.201 markus 2142: return 0;
2143: }
2144:
2145: /* Packet state (de-)serialization for privsep */
2146:
2147: /* turn kex into a blob for packet state serialization */
2148: static int
2149: kex_to_blob(struct sshbuf *m, struct kex *kex)
2150: {
2151: int r;
2152:
2153: if ((r = sshbuf_put_string(m, kex->session_id,
2154: kex->session_id_len)) != 0 ||
2155: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2156: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2157: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2158: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2159: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2160: (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2161: (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2162: (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2163: return r;
2164: return 0;
2165: }
2166:
2167: /* turn key exchange results into a blob for packet state serialization */
2168: static int
2169: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2170: {
2171: struct sshbuf *b;
2172: struct sshcipher_ctx *cc;
2173: struct sshcomp *comp;
2174: struct sshenc *enc;
2175: struct sshmac *mac;
2176: struct newkeys *newkey;
2177: int r;
2178:
2179: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2180: return SSH_ERR_INTERNAL_ERROR;
2181: enc = &newkey->enc;
2182: mac = &newkey->mac;
2183: comp = &newkey->comp;
1.235 djm 2184: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2185: ssh->state->receive_context;
1.201 markus 2186: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2187: return r;
2188: if ((b = sshbuf_new()) == NULL)
2189: return SSH_ERR_ALLOC_FAIL;
2190: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2191: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2192: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2193: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2194: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2195: goto out;
2196: if (cipher_authlen(enc->cipher) == 0) {
2197: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2198: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2199: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2200: goto out;
2201: }
2202: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2203: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2204: goto out;
2205: r = sshbuf_put_stringb(m, b);
2206: out:
1.221 mmcc 2207: sshbuf_free(b);
1.201 markus 2208: return r;
2209: }
2210:
2211: /* serialize packet state into a blob */
2212: int
2213: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2214: {
2215: struct session_state *state = ssh->state;
1.249 djm 2216: int r;
1.201 markus 2217:
1.249 djm 2218: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2219: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2220: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2221: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2222: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2223: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2224: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2225: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2226: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2227: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2228: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2229: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2230: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2231: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2232: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 2233: return r;
1.201 markus 2234:
2235: return 0;
2236: }
2237:
2238: /* restore key exchange results from blob for packet state de-serialization */
2239: static int
2240: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2241: {
2242: struct sshbuf *b = NULL;
2243: struct sshcomp *comp;
2244: struct sshenc *enc;
2245: struct sshmac *mac;
2246: struct newkeys *newkey = NULL;
2247: size_t keylen, ivlen, maclen;
2248: int r;
2249:
2250: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2251: r = SSH_ERR_ALLOC_FAIL;
2252: goto out;
2253: }
2254: if ((r = sshbuf_froms(m, &b)) != 0)
2255: goto out;
2256: #ifdef DEBUG_PK
2257: sshbuf_dump(b, stderr);
2258: #endif
2259: enc = &newkey->enc;
2260: mac = &newkey->mac;
2261: comp = &newkey->comp;
2262:
2263: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2264: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2265: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2266: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2267: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2268: goto out;
1.262 djm 2269: if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2270: r = SSH_ERR_INVALID_FORMAT;
2271: goto out;
2272: }
1.201 markus 2273: if (cipher_authlen(enc->cipher) == 0) {
2274: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2275: goto out;
2276: if ((r = mac_setup(mac, mac->name)) != 0)
2277: goto out;
2278: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2279: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2280: goto out;
2281: if (maclen > mac->key_len) {
2282: r = SSH_ERR_INVALID_FORMAT;
2283: goto out;
2284: }
2285: mac->key_len = maclen;
2286: }
2287: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2288: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2289: goto out;
2290: if (sshbuf_len(b) != 0) {
2291: r = SSH_ERR_INVALID_FORMAT;
2292: goto out;
2293: }
2294: enc->key_len = keylen;
2295: enc->iv_len = ivlen;
2296: ssh->kex->newkeys[mode] = newkey;
2297: newkey = NULL;
2298: r = 0;
2299: out:
1.219 mmcc 2300: free(newkey);
1.221 mmcc 2301: sshbuf_free(b);
1.201 markus 2302: return r;
2303: }
2304:
2305: /* restore kex from blob for packet state de-serialization */
2306: static int
2307: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2308: {
2309: struct kex *kex;
2310: int r;
2311:
2312: if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2313: (kex->my = sshbuf_new()) == NULL ||
2314: (kex->peer = sshbuf_new()) == NULL) {
2315: r = SSH_ERR_ALLOC_FAIL;
2316: goto out;
2317: }
2318: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2319: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2320: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2321: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2322: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2323: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2324: (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2325: (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2326: (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2327: goto out;
2328: kex->server = 1;
2329: kex->done = 1;
2330: r = 0;
2331: out:
2332: if (r != 0 || kexp == NULL) {
2333: if (kex != NULL) {
1.221 mmcc 2334: sshbuf_free(kex->my);
2335: sshbuf_free(kex->peer);
1.201 markus 2336: free(kex);
2337: }
2338: if (kexp != NULL)
2339: *kexp = NULL;
2340: } else {
2341: *kexp = kex;
2342: }
2343: return r;
2344: }
2345:
2346: /*
2347: * Restore packet state from content of blob 'm' (de-serialization).
2348: * Note that 'm' will be partially consumed on parsing or any other errors.
2349: */
2350: int
2351: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2352: {
2353: struct session_state *state = ssh->state;
1.254 djm 2354: const u_char *input, *output;
2355: size_t ilen, olen;
1.201 markus 2356: int r;
2357:
1.249 djm 2358: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2359: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2360: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2361: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2362: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2363: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2364: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2365: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2366: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2367: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2368: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2369: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2370: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2371: return r;
2372: /*
2373: * We set the time here so that in post-auth privsep slave we
2374: * count from the completion of the authentication.
2375: */
2376: state->rekey_time = monotime();
2377: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2378: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2379: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2380: return r;
1.201 markus 2381:
1.239 djm 2382: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2383: return r;
2384:
2385: sshbuf_reset(state->input);
2386: sshbuf_reset(state->output);
2387: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2388: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2389: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2390: (r = sshbuf_put(state->output, output, olen)) != 0)
2391: return r;
2392:
2393: if (sshbuf_len(m))
2394: return SSH_ERR_INVALID_FORMAT;
2395: debug3("%s: done", __func__);
2396: return 0;
2397: }
2398:
2399: /* NEW API */
2400:
2401: /* put data to the outgoing packet */
2402:
2403: int
2404: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2405: {
2406: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2407: }
2408:
2409: int
2410: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2411: {
2412: return sshbuf_putb(ssh->state->outgoing_packet, b);
2413: }
2414:
2415: int
2416: sshpkt_put_u8(struct ssh *ssh, u_char val)
2417: {
2418: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2419: }
2420:
2421: int
2422: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2423: {
2424: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2425: }
2426:
2427: int
2428: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2429: {
2430: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2431: }
2432:
2433: int
2434: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2435: {
2436: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2437: }
2438:
2439: int
2440: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2441: {
2442: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2443: }
2444:
2445: int
2446: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2447: {
2448: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2449: }
2450:
1.211 djm 2451: #ifdef WITH_OPENSSL
1.201 markus 2452: int
2453: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2454: {
2455: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2456: }
2457:
2458:
2459: int
2460: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2461: {
2462: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2463: }
1.211 djm 2464: #endif /* WITH_OPENSSL */
1.201 markus 2465:
2466: /* fetch data from the incoming packet */
2467:
2468: int
2469: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2470: {
2471: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2472: }
2473:
2474: int
2475: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2476: {
2477: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2478: }
2479:
2480: int
2481: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2482: {
2483: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2484: }
2485:
2486: int
2487: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2488: {
2489: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2490: }
2491:
2492: int
2493: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2494: {
2495: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2496: }
2497:
2498: int
2499: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2500: {
2501: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2502: }
2503:
2504: int
1.264 djm 2505: sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2506: {
2507: return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2508: }
2509:
2510: int
1.201 markus 2511: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2512: {
2513: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2514: }
2515:
1.211 djm 2516: #ifdef WITH_OPENSSL
1.201 markus 2517: int
2518: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2519: {
2520: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2521: }
2522:
2523:
2524: int
2525: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2526: {
2527: return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2528: }
1.211 djm 2529: #endif /* WITH_OPENSSL */
1.201 markus 2530:
2531: int
2532: sshpkt_get_end(struct ssh *ssh)
2533: {
2534: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2535: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2536: return 0;
2537: }
2538:
2539: const u_char *
2540: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2541: {
2542: if (lenp != NULL)
2543: *lenp = sshbuf_len(ssh->state->incoming_packet);
2544: return sshbuf_ptr(ssh->state->incoming_packet);
2545: }
2546:
2547: /* start a new packet */
2548:
2549: int
2550: sshpkt_start(struct ssh *ssh, u_char type)
2551: {
1.249 djm 2552: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2553:
2554: DBG(debug("packet_start[%d]", type));
1.249 djm 2555: memset(buf, 0, sizeof(buf));
2556: buf[sizeof(buf) - 1] = type;
1.201 markus 2557: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2558: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2559: }
2560:
1.242 markus 2561: static int
2562: ssh_packet_send_mux(struct ssh *ssh)
2563: {
2564: struct session_state *state = ssh->state;
2565: u_char type, *cp;
2566: size_t len;
2567: int r;
2568:
2569: if (ssh->kex)
2570: return SSH_ERR_INTERNAL_ERROR;
2571: len = sshbuf_len(state->outgoing_packet);
2572: if (len < 6)
2573: return SSH_ERR_INTERNAL_ERROR;
2574: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2575: type = cp[5];
2576: if (ssh_packet_log_type(type))
2577: debug3("%s: type %u", __func__, type);
2578: /* drop everything, but the connection protocol */
2579: if (type >= SSH2_MSG_CONNECTION_MIN &&
2580: type <= SSH2_MSG_CONNECTION_MAX) {
2581: POKE_U32(cp, len - 4);
2582: if ((r = sshbuf_putb(state->output,
2583: state->outgoing_packet)) != 0)
2584: return r;
2585: /* sshbuf_dump(state->output, stderr); */
2586: }
2587: sshbuf_reset(state->outgoing_packet);
1.264 djm 2588: return 0;
2589: }
2590:
2591: /*
2592: * 9.2. Ignored Data Message
2593: *
2594: * byte SSH_MSG_IGNORE
2595: * string data
2596: *
2597: * All implementations MUST understand (and ignore) this message at any
2598: * time (after receiving the protocol version). No implementation is
2599: * required to send them. This message can be used as an additional
2600: * protection measure against advanced traffic analysis techniques.
2601: */
2602: int
2603: sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2604: {
2605: u_int32_t rnd = 0;
2606: int r;
2607: u_int i;
2608:
2609: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2610: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2611: return r;
2612: for (i = 0; i < nbytes; i++) {
2613: if (i % 4 == 0)
2614: rnd = arc4random();
2615: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2616: return r;
2617: rnd >>= 8;
2618: }
1.242 markus 2619: return 0;
2620: }
2621:
1.201 markus 2622: /* send it */
2623:
2624: int
2625: sshpkt_send(struct ssh *ssh)
2626: {
1.242 markus 2627: if (ssh->state && ssh->state->mux)
2628: return ssh_packet_send_mux(ssh);
1.249 djm 2629: return ssh_packet_send2(ssh);
1.201 markus 2630: }
2631:
2632: int
2633: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2634: {
2635: char buf[1024];
2636: va_list args;
2637: int r;
2638:
2639: va_start(args, fmt);
2640: vsnprintf(buf, sizeof(buf), fmt, args);
2641: va_end(args);
2642:
1.249 djm 2643: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2644: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2645: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2646: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2647: (r = sshpkt_send(ssh)) != 0)
2648: return r;
1.201 markus 2649: return 0;
2650: }
2651:
2652: /* roundup current message to pad bytes */
2653: int
2654: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2655: {
2656: ssh->state->extra_pad = pad;
2657: return 0;
1.1 deraadt 2658: }
![[BACK]](/icons/back.gif){kind=icon}
Return to packet.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh