Annotation of src/usr.bin/ssh/packet.c, Revision 1.252
1.252 ! djm 1: /* $OpenBSD: packet.c,v 1.251 2017/04/30 23:26:16 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: /* Session key for protocol v1 */
182: u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
183: u_int ssh1_keylen;
1.25 markus 184:
1.161 andreas 185: /* roundup current message to extra_pad bytes */
186: u_char extra_pad;
1.95 markus 187:
1.161 andreas 188: /* XXX discard incoming data after MAC error */
189: u_int packet_discard;
1.234 markus 190: size_t packet_discard_mac_already;
1.201 markus 191: struct sshmac *packet_discard_mac;
1.71 markus 192:
1.161 andreas 193: /* Used in packet_read_poll2() */
194: u_int packlen;
1.159 markus 195:
1.165 andreas 196: /* Used in packet_send2 */
197: int rekeying;
198:
1.242 markus 199: /* Used in ssh_packet_send_mux() */
200: int mux;
201:
1.165 andreas 202: /* Used in packet_set_interactive */
203: int set_interactive_called;
204:
205: /* Used in packet_set_maxsize */
206: int set_maxsize_called;
207:
1.201 markus 208: /* One-off warning about weak ciphers */
209: int cipher_warning_done;
210:
1.243 djm 211: /* Hook for fuzzing inbound packets */
212: ssh_packet_hook_fn *hook_in;
213: void *hook_in_ctx;
214:
1.161 andreas 215: TAILQ_HEAD(, packet) outgoing;
1.105 markus 216: };
1.161 andreas 217:
1.201 markus 218: struct ssh *
219: ssh_alloc_session_state(void)
1.161 andreas 220: {
1.201 markus 221: struct ssh *ssh = NULL;
222: struct session_state *state = NULL;
1.161 andreas 223:
1.201 markus 224: if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
225: (state = calloc(1, sizeof(*state))) == NULL ||
226: (state->input = sshbuf_new()) == NULL ||
227: (state->output = sshbuf_new()) == NULL ||
228: (state->outgoing_packet = sshbuf_new()) == NULL ||
229: (state->incoming_packet = sshbuf_new()) == NULL)
230: goto fail;
231: TAILQ_INIT(&state->outgoing);
1.202 markus 232: TAILQ_INIT(&ssh->private_keys);
233: TAILQ_INIT(&ssh->public_keys);
1.201 markus 234: state->connection_in = -1;
235: state->connection_out = -1;
236: state->max_packet_size = 32768;
237: state->packet_timeout_ms = -1;
238: state->p_send.packets = state->p_read.packets = 0;
239: state->initialized = 1;
240: /*
241: * ssh_packet_send2() needs to queue packets until
242: * we've done the initial key exchange.
243: */
244: state->rekeying = 1;
245: ssh->state = state;
246: return ssh;
247: fail:
248: if (state) {
249: sshbuf_free(state->input);
250: sshbuf_free(state->output);
251: sshbuf_free(state->incoming_packet);
252: sshbuf_free(state->outgoing_packet);
253: free(state);
254: }
255: free(ssh);
256: return NULL;
1.161 andreas 257: }
1.105 markus 258:
1.243 djm 259: void
260: ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
261: {
262: ssh->state->hook_in = hook;
263: ssh->state->hook_in_ctx = ctx;
264: }
265:
1.228 djm 266: /* Returns nonzero if rekeying is in progress */
267: int
268: ssh_packet_is_rekeying(struct ssh *ssh)
269: {
1.249 djm 270: return ssh->state->rekeying ||
271: (ssh->kex != NULL && ssh->kex->done == 0);
1.228 djm 272: }
273:
1.16 markus 274: /*
275: * Sets the descriptors used for communication. Disables encryption until
276: * packet_set_encryption_key is called.
277: */
1.201 markus 278: struct ssh *
279: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1 deraadt 280: {
1.201 markus 281: struct session_state *state;
282: const struct sshcipher *none = cipher_by_name("none");
1.197 djm 283: int r;
1.97 deraadt 284:
1.205 djm 285: if (none == NULL) {
286: error("%s: cannot load cipher 'none'", __func__);
287: return NULL;
288: }
1.201 markus 289: if (ssh == NULL)
290: ssh = ssh_alloc_session_state();
1.205 djm 291: if (ssh == NULL) {
292: error("%s: cound not allocate state", __func__);
293: return NULL;
294: }
1.201 markus 295: state = ssh->state;
296: state->connection_in = fd_in;
297: state->connection_out = fd_out;
298: if ((r = cipher_init(&state->send_context, none,
1.197 djm 299: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201 markus 300: (r = cipher_init(&state->receive_context, none,
1.205 djm 301: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
302: error("%s: cipher_init failed: %s", __func__, ssh_err(r));
1.230 djm 303: free(ssh); /* XXX need ssh_free_session_state? */
1.205 djm 304: return NULL;
305: }
1.201 markus 306: state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
1.207 djm 307: /*
308: * Cache the IP address of the remote connection for use in error
309: * messages that might be generated after the connection has closed.
310: */
311: (void)ssh_remote_ipaddr(ssh);
1.201 markus 312: return ssh;
1.1 deraadt 313: }
314:
1.154 dtucker 315: void
1.201 markus 316: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 317: {
1.201 markus 318: struct session_state *state = ssh->state;
319:
1.174 djm 320: if (timeout <= 0 || count <= 0) {
1.201 markus 321: state->packet_timeout_ms = -1;
1.154 dtucker 322: return;
323: }
324: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 325: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 326: else
1.201 markus 327: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 328: }
329:
1.242 markus 330: void
331: ssh_packet_set_mux(struct ssh *ssh)
332: {
333: ssh->state->mux = 1;
334: ssh->state->rekeying = 0;
335: }
336:
337: int
338: ssh_packet_get_mux(struct ssh *ssh)
339: {
340: return ssh->state->mux;
341: }
342:
1.201 markus 343: int
1.245 djm 344: ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
345: {
346: va_list args;
347: int r;
348:
349: free(ssh->log_preamble);
350: if (fmt == NULL)
351: ssh->log_preamble = NULL;
352: else {
353: va_start(args, fmt);
354: r = vasprintf(&ssh->log_preamble, fmt, args);
355: va_end(args);
356: if (r < 0 || ssh->log_preamble == NULL)
357: return SSH_ERR_ALLOC_FAIL;
358: }
359: return 0;
360: }
361:
362: int
1.201 markus 363: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 364: {
1.201 markus 365: struct session_state *state = ssh->state;
366: int r;
367:
368: if (state->packet_discard_mac) {
1.159 markus 369: char buf[1024];
1.234 markus 370: size_t dlen = PACKET_MAX_SIZE;
1.201 markus 371:
1.234 markus 372: if (dlen > state->packet_discard_mac_already)
373: dlen -= state->packet_discard_mac_already;
1.159 markus 374: memset(buf, 'a', sizeof(buf));
1.234 markus 375: while (sshbuf_len(state->incoming_packet) < dlen)
1.201 markus 376: if ((r = sshbuf_put(state->incoming_packet, buf,
377: sizeof(buf))) != 0)
378: return r;
379: (void) mac_compute(state->packet_discard_mac,
380: state->p_read.seqnr,
1.234 markus 381: sshbuf_ptr(state->incoming_packet), dlen,
1.201 markus 382: NULL, 0);
1.159 markus 383: }
1.220 djm 384: logit("Finished discarding for %.200s port %d",
385: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 386: return SSH_ERR_MAC_INVALID;
1.159 markus 387: }
388:
1.201 markus 389: static int
390: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
1.234 markus 391: struct sshmac *mac, size_t mac_already, u_int discard)
1.159 markus 392: {
1.201 markus 393: struct session_state *state = ssh->state;
394: int r;
395:
396: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
397: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
398: return r;
399: return SSH_ERR_MAC_INVALID;
400: }
1.234 markus 401: /*
402: * Record number of bytes over which the mac has already
403: * been computed in order to minimize timing attacks.
404: */
405: if (mac && mac->enabled) {
1.201 markus 406: state->packet_discard_mac = mac;
1.234 markus 407: state->packet_discard_mac_already = mac_already;
408: }
409: if (sshbuf_len(state->input) >= discard)
410: return ssh_packet_stop_discard(ssh);
1.201 markus 411: state->packet_discard = discard - sshbuf_len(state->input);
412: return 0;
1.159 markus 413: }
414:
1.19 markus 415: /* Returns 1 if remote host is connected via socket, 0 if not. */
416:
417: int
1.201 markus 418: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 419: {
1.201 markus 420: struct session_state *state = ssh->state;
1.19 markus 421: struct sockaddr_storage from, to;
422: socklen_t fromlen, tolen;
423:
1.230 djm 424: if (state->connection_in == -1 || state->connection_out == -1)
425: return 0;
426:
1.19 markus 427: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 428: if (state->connection_in == state->connection_out)
1.19 markus 429: return 1;
430: fromlen = sizeof(from);
431: memset(&from, 0, sizeof(from));
1.201 markus 432: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.161 andreas 433: &fromlen) < 0)
1.19 markus 434: return 0;
435: tolen = sizeof(to);
436: memset(&to, 0, sizeof(to));
1.201 markus 437: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.161 andreas 438: &tolen) < 0)
1.19 markus 439: return 0;
440: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
441: return 0;
442: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
443: return 0;
444: return 1;
445: }
446:
1.91 markus 447: void
1.201 markus 448: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 449: {
1.201 markus 450: if (ibytes)
451: *ibytes = ssh->state->p_read.bytes;
452: if (obytes)
453: *obytes = ssh->state->p_send.bytes;
1.91 markus 454: }
1.125 deraadt 455:
1.91 markus 456: int
1.201 markus 457: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 458: {
459: struct sockaddr_storage to;
1.21 deraadt 460: socklen_t tolen = sizeof(to);
1.19 markus 461:
462: memset(&to, 0, sizeof(to));
1.201 markus 463: if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
1.161 andreas 464: &tolen) < 0)
1.19 markus 465: return 0;
1.173 djm 466: return to.ss_family;
1.19 markus 467: }
468:
1.1 deraadt 469: /* Sets the connection into non-blocking mode. */
470:
1.2 provos 471: void
1.201 markus 472: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 473: {
1.14 markus 474: /* Set the socket into non-blocking mode. */
1.201 markus 475: set_nonblock(ssh->state->connection_in);
1.14 markus 476:
1.201 markus 477: if (ssh->state->connection_out != ssh->state->connection_in)
478: set_nonblock(ssh->state->connection_out);
1.1 deraadt 479: }
480:
481: /* Returns the socket used for reading. */
482:
1.2 provos 483: int
1.201 markus 484: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 485: {
1.201 markus 486: return ssh->state->connection_in;
1.1 deraadt 487: }
488:
489: /* Returns the descriptor used for writing. */
490:
1.2 provos 491: int
1.201 markus 492: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 493: {
1.201 markus 494: return ssh->state->connection_out;
495: }
496:
497: /*
498: * Returns the IP-address of the remote host as a string. The returned
499: * string must not be freed.
500: */
501:
502: const char *
503: ssh_remote_ipaddr(struct ssh *ssh)
504: {
1.220 djm 505: const int sock = ssh->state->connection_in;
506:
1.201 markus 507: /* Check whether we have cached the ipaddr. */
1.220 djm 508: if (ssh->remote_ipaddr == NULL) {
509: if (ssh_packet_connection_is_on_socket(ssh)) {
510: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 djm 511: ssh->remote_port = get_peer_port(sock);
512: ssh->local_ipaddr = get_local_ipaddr(sock);
513: ssh->local_port = get_local_port(sock);
1.220 djm 514: } else {
515: ssh->remote_ipaddr = strdup("UNKNOWN");
1.230 djm 516: ssh->remote_port = 65535;
517: ssh->local_ipaddr = strdup("UNKNOWN");
518: ssh->local_port = 65535;
1.220 djm 519: }
520: }
1.201 markus 521: return ssh->remote_ipaddr;
1.1 deraadt 522: }
523:
1.220 djm 524: /* Returns the port number of the remote host. */
525:
526: int
527: ssh_remote_port(struct ssh *ssh)
528: {
529: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
530: return ssh->remote_port;
1.230 djm 531: }
532:
533: /*
534: * Returns the IP-address of the local host as a string. The returned
535: * string must not be freed.
536: */
537:
538: const char *
539: ssh_local_ipaddr(struct ssh *ssh)
540: {
541: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
542: return ssh->local_ipaddr;
543: }
544:
545: /* Returns the port number of the local host. */
546:
547: int
548: ssh_local_port(struct ssh *ssh)
549: {
550: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
551: return ssh->local_port;
1.220 djm 552: }
553:
1.1 deraadt 554: /* Closes the connection and clears and frees internal data structures. */
555:
1.2 provos 556: void
1.201 markus 557: ssh_packet_close(struct ssh *ssh)
1.1 deraadt 558: {
1.201 markus 559: struct session_state *state = ssh->state;
560: u_int mode;
561:
562: if (!state->initialized)
1.14 markus 563: return;
1.201 markus 564: state->initialized = 0;
565: if (state->connection_in == state->connection_out) {
566: shutdown(state->connection_out, SHUT_RDWR);
567: close(state->connection_out);
1.14 markus 568: } else {
1.201 markus 569: close(state->connection_in);
570: close(state->connection_out);
1.14 markus 571: }
1.201 markus 572: sshbuf_free(state->input);
573: sshbuf_free(state->output);
574: sshbuf_free(state->outgoing_packet);
575: sshbuf_free(state->incoming_packet);
576: for (mode = 0; mode < MODE_MAX; mode++)
577: kex_free_newkeys(state->newkeys[mode]);
578: if (state->compression_buffer) {
579: sshbuf_free(state->compression_buffer);
580: if (state->compression_out_started) {
581: z_streamp stream = &state->compression_out_stream;
582: debug("compress outgoing: "
583: "raw data %llu, compressed %llu, factor %.2f",
584: (unsigned long long)stream->total_in,
585: (unsigned long long)stream->total_out,
586: stream->total_in == 0 ? 0.0 :
587: (double) stream->total_out / stream->total_in);
588: if (state->compression_out_failures == 0)
589: deflateEnd(stream);
590: }
591: if (state->compression_in_started) {
592: z_streamp stream = &state->compression_out_stream;
593: debug("compress incoming: "
594: "raw data %llu, compressed %llu, factor %.2f",
595: (unsigned long long)stream->total_out,
596: (unsigned long long)stream->total_in,
597: stream->total_out == 0 ? 0.0 :
598: (double) stream->total_in / stream->total_out);
599: if (state->compression_in_failures == 0)
600: inflateEnd(stream);
601: }
1.14 markus 602: }
1.235 djm 603: cipher_free(state->send_context);
604: cipher_free(state->receive_context);
605: state->send_context = state->receive_context = NULL;
1.219 mmcc 606: free(ssh->remote_ipaddr);
607: ssh->remote_ipaddr = NULL;
1.201 markus 608: free(ssh->state);
609: ssh->state = NULL;
1.1 deraadt 610: }
611:
612: /* Sets remote side protocol flags. */
613:
1.2 provos 614: void
1.201 markus 615: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 616: {
1.201 markus 617: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 618: }
619:
620: /* Returns the remote protocol flags set earlier by the above function. */
621:
1.40 markus 622: u_int
1.201 markus 623: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 624: {
1.201 markus 625: return ssh->state->remote_protocol_flags;
1.1 deraadt 626: }
627:
1.16 markus 628: /*
629: * Starts packet compression from the next packet on in both directions.
630: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
631: */
1.1 deraadt 632:
1.201 markus 633: static int
634: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 635: {
1.201 markus 636: if (!ssh->state->compression_buffer &&
637: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
638: return SSH_ERR_ALLOC_FAIL;
639: return 0;
1.60 markus 640: }
641:
1.201 markus 642: static int
643: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 644: {
1.201 markus 645: if (level < 1 || level > 9)
646: return SSH_ERR_INVALID_ARGUMENT;
647: debug("Enabling compression at level %d.", level);
648: if (ssh->state->compression_out_started == 1)
649: deflateEnd(&ssh->state->compression_out_stream);
650: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
651: case Z_OK:
652: ssh->state->compression_out_started = 1;
653: break;
654: case Z_MEM_ERROR:
655: return SSH_ERR_ALLOC_FAIL;
656: default:
657: return SSH_ERR_INTERNAL_ERROR;
658: }
659: return 0;
1.1 deraadt 660: }
661:
1.201 markus 662: static int
663: start_compression_in(struct ssh *ssh)
664: {
665: if (ssh->state->compression_in_started == 1)
666: inflateEnd(&ssh->state->compression_in_stream);
667: switch (inflateInit(&ssh->state->compression_in_stream)) {
668: case Z_OK:
669: ssh->state->compression_in_started = 1;
670: break;
671: case Z_MEM_ERROR:
672: return SSH_ERR_ALLOC_FAIL;
673: default:
674: return SSH_ERR_INTERNAL_ERROR;
675: }
676: return 0;
677: }
1.95 markus 678:
1.201 markus 679: int
680: ssh_packet_start_compression(struct ssh *ssh, int level)
1.1 deraadt 681: {
1.197 djm 682: int r;
1.97 deraadt 683:
1.249 djm 684: if (ssh->state->packet_compression)
1.201 markus 685: return SSH_ERR_INTERNAL_ERROR;
686: ssh->state->packet_compression = 1;
687: if ((r = ssh_packet_init_compression(ssh)) != 0 ||
688: (r = start_compression_in(ssh)) != 0 ||
689: (r = start_compression_out(ssh, level)) != 0)
690: return r;
691: return 0;
1.95 markus 692: }
693:
1.201 markus 694: /* XXX remove need for separate compression buffer */
695: static int
696: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 697: {
1.201 markus 698: u_char buf[4096];
699: int r, status;
700:
701: if (ssh->state->compression_out_started != 1)
702: return SSH_ERR_INTERNAL_ERROR;
703:
704: /* This case is not handled below. */
705: if (sshbuf_len(in) == 0)
706: return 0;
707:
708: /* Input is the contents of the input buffer. */
709: if ((ssh->state->compression_out_stream.next_in =
710: sshbuf_mutable_ptr(in)) == NULL)
711: return SSH_ERR_INTERNAL_ERROR;
712: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
713:
714: /* Loop compressing until deflate() returns with avail_out != 0. */
715: do {
716: /* Set up fixed-size output buffer. */
717: ssh->state->compression_out_stream.next_out = buf;
718: ssh->state->compression_out_stream.avail_out = sizeof(buf);
719:
720: /* Compress as much data into the buffer as possible. */
721: status = deflate(&ssh->state->compression_out_stream,
722: Z_PARTIAL_FLUSH);
723: switch (status) {
724: case Z_MEM_ERROR:
725: return SSH_ERR_ALLOC_FAIL;
726: case Z_OK:
727: /* Append compressed data to output_buffer. */
728: if ((r = sshbuf_put(out, buf, sizeof(buf) -
729: ssh->state->compression_out_stream.avail_out)) != 0)
730: return r;
731: break;
732: case Z_STREAM_ERROR:
733: default:
734: ssh->state->compression_out_failures++;
735: return SSH_ERR_INVALID_FORMAT;
736: }
737: } while (ssh->state->compression_out_stream.avail_out == 0);
738: return 0;
1.1 deraadt 739: }
740:
1.201 markus 741: static int
742: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 743: {
1.201 markus 744: u_char buf[4096];
745: int r, status;
1.1 deraadt 746:
1.201 markus 747: if (ssh->state->compression_in_started != 1)
748: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 749:
1.201 markus 750: if ((ssh->state->compression_in_stream.next_in =
751: sshbuf_mutable_ptr(in)) == NULL)
752: return SSH_ERR_INTERNAL_ERROR;
753: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 754:
1.201 markus 755: for (;;) {
756: /* Set up fixed-size output buffer. */
757: ssh->state->compression_in_stream.next_out = buf;
758: ssh->state->compression_in_stream.avail_out = sizeof(buf);
759:
760: status = inflate(&ssh->state->compression_in_stream,
761: Z_PARTIAL_FLUSH);
762: switch (status) {
763: case Z_OK:
764: if ((r = sshbuf_put(out, buf, sizeof(buf) -
765: ssh->state->compression_in_stream.avail_out)) != 0)
766: return r;
767: break;
768: case Z_BUF_ERROR:
769: /*
770: * Comments in zlib.h say that we should keep calling
771: * inflate() until we get an error. This appears to
772: * be the error that we get.
773: */
774: return 0;
775: case Z_DATA_ERROR:
776: return SSH_ERR_INVALID_FORMAT;
777: case Z_MEM_ERROR:
778: return SSH_ERR_ALLOC_FAIL;
779: case Z_STREAM_ERROR:
780: default:
781: ssh->state->compression_in_failures++;
782: return SSH_ERR_INTERNAL_ERROR;
783: }
784: }
785: /* NOTREACHED */
1.1 deraadt 786: }
1.125 deraadt 787:
1.201 markus 788: /*
789: * Causes any further packets to be encrypted using the given key. The same
790: * key is used for both sending and reception. However, both directions are
791: * encrypted independently of each other.
792: */
1.125 deraadt 793:
1.2 provos 794: void
1.201 markus 795: ssh_packet_set_encryption_key(struct ssh *ssh, const u_char *key, u_int keylen, int number)
1.1 deraadt 796: {
1.211 djm 797: fatal("no SSH protocol 1 support");
1.170 djm 798: }
799:
1.201 markus 800: int
801: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 802: {
1.201 markus 803: struct session_state *state = ssh->state;
804: struct sshenc *enc;
805: struct sshmac *mac;
806: struct sshcomp *comp;
1.235 djm 807: struct sshcipher_ctx **ccp;
1.236 markus 808: struct packet_state *ps;
1.105 markus 809: u_int64_t *max_blocks;
1.236 markus 810: const char *wmsg, *dir;
1.197 djm 811: int r, crypt_type;
1.57 markus 812:
1.100 markus 813: debug2("set_newkeys: mode %d", mode);
1.57 markus 814:
1.88 markus 815: if (mode == MODE_OUT) {
1.236 markus 816: dir = "output";
1.235 djm 817: ccp = &state->send_context;
1.115 avsm 818: crypt_type = CIPHER_ENCRYPT;
1.236 markus 819: ps = &state->p_send;
1.201 markus 820: max_blocks = &state->max_blocks_out;
1.88 markus 821: } else {
1.236 markus 822: dir = "input";
1.235 djm 823: ccp = &state->receive_context;
1.115 avsm 824: crypt_type = CIPHER_DECRYPT;
1.236 markus 825: ps = &state->p_read;
1.201 markus 826: max_blocks = &state->max_blocks_in;
1.88 markus 827: }
1.201 markus 828: if (state->newkeys[mode] != NULL) {
1.236 markus 829: debug("%s: rekeying after %llu %s blocks"
830: " (%llu bytes total)", __func__,
831: (unsigned long long)ps->blocks, dir,
832: (unsigned long long)ps->bytes);
1.235 djm 833: cipher_free(*ccp);
834: *ccp = NULL;
1.201 markus 835: enc = &state->newkeys[mode]->enc;
836: mac = &state->newkeys[mode]->mac;
837: comp = &state->newkeys[mode]->comp;
1.148 pvalchev 838: mac_clear(mac);
1.192 djm 839: explicit_bzero(enc->iv, enc->iv_len);
840: explicit_bzero(enc->key, enc->key_len);
841: explicit_bzero(mac->key, mac->key_len);
1.186 djm 842: free(enc->name);
843: free(enc->iv);
844: free(enc->key);
845: free(mac->name);
846: free(mac->key);
847: free(comp->name);
1.201 markus 848: free(state->newkeys[mode]);
1.57 markus 849: }
1.236 markus 850: /* note that both bytes and the seqnr are not reset */
851: ps->packets = ps->blocks = 0;
1.201 markus 852: /* move newkeys from kex to state */
853: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
854: return SSH_ERR_INTERNAL_ERROR;
855: ssh->kex->newkeys[mode] = NULL;
856: enc = &state->newkeys[mode]->enc;
857: mac = &state->newkeys[mode]->mac;
858: comp = &state->newkeys[mode]->comp;
859: if (cipher_authlen(enc->cipher) == 0) {
860: if ((r = mac_init(mac)) != 0)
861: return r;
862: }
863: mac->enabled = 1;
1.57 markus 864: DBG(debug("cipher_init_context: %d", mode));
1.235 djm 865: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 866: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 867: return r;
868: if (!state->cipher_warning_done &&
1.235 djm 869: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 870: error("Warning: %s", wmsg);
871: state->cipher_warning_done = 1;
872: }
1.91 markus 873: /* Deleting the keys does not gain extra security */
1.192 djm 874: /* explicit_bzero(enc->iv, enc->block_size);
875: explicit_bzero(enc->key, enc->key_len);
876: explicit_bzero(mac->key, mac->key_len); */
1.241 djm 877: if ((comp->type == COMP_ZLIB ||
878: (comp->type == COMP_DELAYED &&
879: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 880: if ((r = ssh_packet_init_compression(ssh)) < 0)
881: return r;
882: if (mode == MODE_OUT) {
883: if ((r = start_compression_out(ssh, 6)) != 0)
884: return r;
885: } else {
886: if ((r = start_compression_in(ssh)) != 0)
887: return r;
888: }
1.57 markus 889: comp->enabled = 1;
890: }
1.109 markus 891: /*
892: * The 2^(blocksize*2) limit is too expensive for 3DES,
893: * blowfish, etc, so enforce a 1GB limit for small blocksizes.
894: */
895: if (enc->block_size >= 16)
896: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
897: else
898: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 899: if (state->rekey_limit)
1.237 deraadt 900: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 901: state->rekey_limit / enc->block_size);
1.227 djm 902: debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1.201 markus 903: return 0;
1.57 markus 904: }
905:
1.228 djm 906: #define MAX_PACKETS (1U<<31)
907: static int
908: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
909: {
910: struct session_state *state = ssh->state;
911: u_int32_t out_blocks;
912:
913: /* XXX client can't cope with rekeying pre-auth */
914: if (!state->after_authentication)
915: return 0;
916:
917: /* Haven't keyed yet or KEX in progress. */
918: if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
919: return 0;
920:
921: /* Peer can't rekey */
922: if (ssh->compat & SSH_BUG_NOREKEY)
923: return 0;
924:
925: /*
926: * Permit one packet in or out per rekey - this allows us to
927: * make progress when rekey limits are very small.
928: */
929: if (state->p_send.packets == 0 && state->p_read.packets == 0)
930: return 0;
931:
932: /* Time-based rekeying */
933: if (state->rekey_interval != 0 &&
1.244 dtucker 934: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 935: return 1;
936:
937: /* Always rekey when MAX_PACKETS sent in either direction */
938: if (state->p_send.packets > MAX_PACKETS ||
939: state->p_read.packets > MAX_PACKETS)
940: return 1;
941:
942: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 943: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 944: state->newkeys[MODE_OUT]->enc.block_size);
945: return (state->max_blocks_out &&
946: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
947: (state->max_blocks_in &&
948: (state->p_read.blocks > state->max_blocks_in));
949: }
950:
1.16 markus 951: /*
1.118 markus 952: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 953: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 954: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
955: */
1.201 markus 956: static int
957: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 958: {
1.201 markus 959: struct session_state *state = ssh->state;
960: struct sshcomp *comp = NULL;
961: int r, mode;
1.118 markus 962:
963: /*
964: * Remember that we are past the authentication step, so rekeying
965: * with COMP_DELAYED will turn on compression immediately.
966: */
1.201 markus 967: state->after_authentication = 1;
1.118 markus 968: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 969: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 970: if (state->newkeys[mode] == NULL)
1.145 markus 971: continue;
1.201 markus 972: comp = &state->newkeys[mode]->comp;
1.118 markus 973: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 974: if ((r = ssh_packet_init_compression(ssh)) != 0)
975: return r;
976: if (mode == MODE_OUT) {
977: if ((r = start_compression_out(ssh, 6)) != 0)
978: return r;
979: } else {
980: if ((r = start_compression_in(ssh)) != 0)
981: return r;
982: }
1.118 markus 983: comp->enabled = 1;
984: }
985: }
1.201 markus 986: return 0;
1.118 markus 987: }
988:
1.226 djm 989: /* Used to mute debug logging for noisy packet types */
1.242 markus 990: int
1.226 djm 991: ssh_packet_log_type(u_char type)
992: {
993: switch (type) {
994: case SSH2_MSG_CHANNEL_DATA:
995: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
996: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
997: return 0;
998: default:
999: return 1;
1000: }
1001: }
1002:
1.118 markus 1003: /*
1.25 markus 1004: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1005: */
1.201 markus 1006: int
1007: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1008: {
1.201 markus 1009: struct session_state *state = ssh->state;
1.200 markus 1010: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1011: u_char tmp, padlen, pad = 0;
1.201 markus 1012: u_int authlen = 0, aadlen = 0;
1013: u_int len;
1014: struct sshenc *enc = NULL;
1015: struct sshmac *mac = NULL;
1016: struct sshcomp *comp = NULL;
1017: int r, block_size;
1018:
1019: if (state->newkeys[MODE_OUT] != NULL) {
1020: enc = &state->newkeys[MODE_OUT]->enc;
1021: mac = &state->newkeys[MODE_OUT]->mac;
1022: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1023: /* disable mac for authenticated encryption */
1024: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1025: mac = NULL;
1.25 markus 1026: }
1.88 markus 1027: block_size = enc ? enc->block_size : 8;
1.180 markus 1028: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1029:
1.201 markus 1030: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1031: if (ssh_packet_log_type(type))
1032: debug3("send packet: type %u", type);
1.25 markus 1033: #ifdef PACKET_DEBUG
1034: fprintf(stderr, "plain: ");
1.201 markus 1035: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1036: #endif
1037:
1038: if (comp && comp->enabled) {
1.201 markus 1039: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1040: /* skip header, compress only payload */
1.201 markus 1041: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1042: goto out;
1043: sshbuf_reset(state->compression_buffer);
1044: if ((r = compress_buffer(ssh, state->outgoing_packet,
1045: state->compression_buffer)) != 0)
1046: goto out;
1047: sshbuf_reset(state->outgoing_packet);
1048: if ((r = sshbuf_put(state->outgoing_packet,
1049: "\0\0\0\0\0", 5)) != 0 ||
1050: (r = sshbuf_putb(state->outgoing_packet,
1051: state->compression_buffer)) != 0)
1052: goto out;
1053: DBG(debug("compression: raw %d compressed %zd", len,
1054: sshbuf_len(state->outgoing_packet)));
1.25 markus 1055: }
1056:
1057: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1058: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1059:
1060: /*
1061: * calc size of padding, alloc space, get random data,
1062: * minimum padding is 4 bytes
1063: */
1.178 markus 1064: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1065: padlen = block_size - (len % block_size);
1066: if (padlen < 4)
1067: padlen += block_size;
1.201 markus 1068: if (state->extra_pad) {
1.233 djm 1069: tmp = state->extra_pad;
1.201 markus 1070: state->extra_pad =
1.237 deraadt 1071: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1072: /* check if roundup overflowed */
1073: if (state->extra_pad < tmp)
1074: return SSH_ERR_INVALID_ARGUMENT;
1075: tmp = (len + padlen) % state->extra_pad;
1076: /* Check whether pad calculation below will underflow */
1077: if (tmp > state->extra_pad)
1078: return SSH_ERR_INVALID_ARGUMENT;
1079: pad = state->extra_pad - tmp;
1.193 djm 1080: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1081: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1082: tmp = padlen;
1.71 markus 1083: padlen += pad;
1.233 djm 1084: /* Check whether padlen calculation overflowed */
1085: if (padlen < tmp)
1086: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1087: state->extra_pad = 0;
1.71 markus 1088: }
1.201 markus 1089: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1090: goto out;
1.235 djm 1091: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1092: /* random padding */
1.201 markus 1093: arc4random_buf(cp, padlen);
1.32 markus 1094: } else {
1095: /* clear padding */
1.192 djm 1096: explicit_bzero(cp, padlen);
1.25 markus 1097: }
1.178 markus 1098: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1099: len = sshbuf_len(state->outgoing_packet);
1100: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1101: if (cp == NULL) {
1102: r = SSH_ERR_INTERNAL_ERROR;
1103: goto out;
1104: }
1.25 markus 1105: /* packet_length includes payload, padding and padding length field */
1.201 markus 1106: POKE_U32(cp, len - 4);
1.89 markus 1107: cp[4] = padlen;
1.178 markus 1108: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1109: len, padlen, aadlen));
1.25 markus 1110:
1111: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1112: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1113: if ((r = mac_compute(mac, state->p_send.seqnr,
1114: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1115: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1116: goto out;
1117: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1118: }
1119: /* encrypt packet and append to output buffer. */
1.201 markus 1120: if ((r = sshbuf_reserve(state->output,
1121: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1122: goto out;
1.235 djm 1123: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1124: sshbuf_ptr(state->outgoing_packet),
1125: len - aadlen, aadlen, authlen)) != 0)
1126: goto out;
1.25 markus 1127: /* append unencrypted MAC */
1.178 markus 1128: if (mac && mac->enabled) {
1129: if (mac->etm) {
1130: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1131: if ((r = mac_compute(mac, state->p_send.seqnr,
1132: cp, len, macbuf, sizeof(macbuf))) != 0)
1133: goto out;
1.178 markus 1134: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1135: state->p_send.seqnr));
1.178 markus 1136: }
1.201 markus 1137: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1138: goto out;
1.178 markus 1139: }
1.25 markus 1140: #ifdef PACKET_DEBUG
1141: fprintf(stderr, "encrypted: ");
1.201 markus 1142: sshbuf_dump(state->output, stderr);
1.25 markus 1143: #endif
1.29 markus 1144: /* increment sequence number for outgoing packets */
1.201 markus 1145: if (++state->p_send.seqnr == 0)
1.106 itojun 1146: logit("outgoing seqnr wraps around");
1.201 markus 1147: if (++state->p_send.packets == 0)
1148: if (!(ssh->compat & SSH_BUG_NOREKEY))
1149: return SSH_ERR_NEED_REKEY;
1150: state->p_send.blocks += len / block_size;
1151: state->p_send.bytes += len;
1152: sshbuf_reset(state->outgoing_packet);
1.25 markus 1153:
1.57 markus 1154: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1155: r = ssh_set_newkeys(ssh, MODE_OUT);
1156: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1157: r = ssh_packet_enable_delayed_compress(ssh);
1158: else
1159: r = 0;
1160: out:
1161: return r;
1.25 markus 1162: }
1163:
1.228 djm 1164: /* returns non-zero if the specified packet type is usec by KEX */
1165: static int
1166: ssh_packet_type_is_kex(u_char type)
1167: {
1168: return
1169: type >= SSH2_MSG_TRANSPORT_MIN &&
1170: type <= SSH2_MSG_TRANSPORT_MAX &&
1171: type != SSH2_MSG_SERVICE_REQUEST &&
1172: type != SSH2_MSG_SERVICE_ACCEPT &&
1173: type != SSH2_MSG_EXT_INFO;
1174: }
1175:
1.201 markus 1176: int
1177: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1178: {
1.201 markus 1179: struct session_state *state = ssh->state;
1.105 markus 1180: struct packet *p;
1.201 markus 1181: u_char type;
1.228 djm 1182: int r, need_rekey;
1.105 markus 1183:
1.228 djm 1184: if (sshbuf_len(state->outgoing_packet) < 6)
1185: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1186: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1187: need_rekey = !ssh_packet_type_is_kex(type) &&
1188: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1189:
1.228 djm 1190: /*
1191: * During rekeying we can only send key exchange messages.
1192: * Queue everything else.
1193: */
1194: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1195: if (need_rekey)
1196: debug3("%s: rekex triggered", __func__);
1197: debug("enqueue packet: %u", type);
1198: p = calloc(1, sizeof(*p));
1199: if (p == NULL)
1200: return SSH_ERR_ALLOC_FAIL;
1201: p->type = type;
1202: p->payload = state->outgoing_packet;
1203: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1204: state->outgoing_packet = sshbuf_new();
1205: if (state->outgoing_packet == NULL)
1206: return SSH_ERR_ALLOC_FAIL;
1207: if (need_rekey) {
1208: /*
1209: * This packet triggered a rekey, so send the
1210: * KEXINIT now.
1211: * NB. reenters this function via kex_start_rekex().
1212: */
1213: return kex_start_rekex(ssh);
1.105 markus 1214: }
1.228 djm 1215: return 0;
1.105 markus 1216: }
1217:
1218: /* rekeying starts with sending KEXINIT */
1219: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1220: state->rekeying = 1;
1.105 markus 1221:
1.201 markus 1222: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1223: return r;
1.105 markus 1224:
1225: /* after a NEWKEYS message we can send the complete queue */
1226: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1227: state->rekeying = 0;
1228: state->rekey_time = monotime();
1229: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1230: type = p->type;
1.228 djm 1231: /*
1232: * If this packet triggers a rekex, then skip the
1233: * remaining packets in the queue for now.
1234: * NB. re-enters this function via kex_start_rekex.
1235: */
1236: if (ssh_packet_need_rekeying(ssh,
1237: sshbuf_len(p->payload))) {
1238: debug3("%s: queued packet triggered rekex",
1239: __func__);
1240: return kex_start_rekex(ssh);
1241: }
1.105 markus 1242: debug("dequeue packet: %u", type);
1.201 markus 1243: sshbuf_free(state->outgoing_packet);
1244: state->outgoing_packet = p->payload;
1245: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1246: memset(p, 0, sizeof(*p));
1.186 djm 1247: free(p);
1.201 markus 1248: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1249: return r;
1.105 markus 1250: }
1251: }
1.201 markus 1252: return 0;
1.25 markus 1253: }
1254:
1255: /*
1.16 markus 1256: * Waits until a packet has been received, and returns its type. Note that
1257: * no other data is processed until this returns, so this function should not
1258: * be used during the interactive session.
1259: */
1.1 deraadt 1260:
1.2 provos 1261: int
1.201 markus 1262: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1263: {
1.201 markus 1264: struct session_state *state = ssh->state;
1.222 markus 1265: int len, r, ms_remain;
1.56 millert 1266: fd_set *setp;
1.14 markus 1267: char buf[8192];
1.155 deraadt 1268: struct timeval timeout, start, *timeoutp = NULL;
1269:
1.25 markus 1270: DBG(debug("packet_read()"));
1.14 markus 1271:
1.214 deraadt 1272: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1273: NFDBITS), sizeof(fd_mask));
1.201 markus 1274: if (setp == NULL)
1275: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1276:
1.205 djm 1277: /*
1278: * Since we are blocking, ensure that all written packets have
1279: * been sent.
1280: */
1.210 markus 1281: if ((r = ssh_packet_write_wait(ssh)) != 0)
1282: goto out;
1.14 markus 1283:
1284: /* Stay in the loop until we have received a complete packet. */
1285: for (;;) {
1286: /* Try to read a packet from the buffer. */
1.201 markus 1287: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1288: if (r != 0)
1289: break;
1.14 markus 1290: /* If we got a packet, return it. */
1.201 markus 1291: if (*typep != SSH_MSG_NONE)
1292: break;
1.16 markus 1293: /*
1294: * Otherwise, wait for some data to arrive, add it to the
1295: * buffer, and try again.
1296: */
1.201 markus 1297: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1298: NFDBITS) * sizeof(fd_mask));
1.201 markus 1299: FD_SET(state->connection_in, setp);
1.16 markus 1300:
1.201 markus 1301: if (state->packet_timeout_ms > 0) {
1302: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1303: timeoutp = &timeout;
1304: }
1.14 markus 1305: /* Wait for some data to arrive. */
1.154 dtucker 1306: for (;;) {
1.201 markus 1307: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1308: ms_to_timeval(&timeout, ms_remain);
1309: gettimeofday(&start, NULL);
1310: }
1.201 markus 1311: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1312: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1313: break;
1.161 andreas 1314: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1315: break;
1.201 markus 1316: if (state->packet_timeout_ms == -1)
1.154 dtucker 1317: continue;
1318: ms_subtract_diff(&start, &ms_remain);
1319: if (ms_remain <= 0) {
1.201 markus 1320: r = 0;
1.154 dtucker 1321: break;
1322: }
1323: }
1.246 djm 1324: if (r == 0) {
1325: r = SSH_ERR_CONN_TIMEOUT;
1326: goto out;
1327: }
1.14 markus 1328: /* Read data from the socket. */
1.222 markus 1329: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1330: if (len == 0) {
1331: r = SSH_ERR_CONN_CLOSED;
1332: goto out;
1333: }
1334: if (len < 0) {
1335: r = SSH_ERR_SYSTEM_ERROR;
1336: goto out;
1337: }
1.204 djm 1338:
1.14 markus 1339: /* Append it to the buffer. */
1.204 djm 1340: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1341: goto out;
1.14 markus 1342: }
1.210 markus 1343: out:
1.201 markus 1344: free(setp);
1345: return r;
1.1 deraadt 1346: }
1347:
1.77 djm 1348: int
1.201 markus 1349: ssh_packet_read(struct ssh *ssh)
1.77 djm 1350: {
1.201 markus 1351: u_char type;
1352: int r;
1353:
1354: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1355: fatal("%s: %s", __func__, ssh_err(r));
1356: return type;
1.77 djm 1357: }
1358:
1.16 markus 1359: /*
1360: * Waits until a packet has been received, verifies that its type matches
1361: * that given, and gives a fatal error and exits if there is a mismatch.
1362: */
1.1 deraadt 1363:
1.205 djm 1364: int
1365: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1366: {
1.205 djm 1367: int r;
1368: u_char type;
1.1 deraadt 1369:
1.205 djm 1370: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1371: return r;
1372: if (type != expected_type) {
1373: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1374: "Protocol error: expected packet type %d, got %d",
1.205 djm 1375: expected_type, type)) != 0)
1376: return r;
1377: return SSH_ERR_PROTOCOL_ERROR;
1378: }
1379: return 0;
1.1 deraadt 1380: }
1.14 markus 1381:
1.242 markus 1382: static int
1383: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1384: {
1385: struct session_state *state = ssh->state;
1386: const u_char *cp;
1387: size_t need;
1388: int r;
1389:
1390: if (ssh->kex)
1391: return SSH_ERR_INTERNAL_ERROR;
1392: *typep = SSH_MSG_NONE;
1393: cp = sshbuf_ptr(state->input);
1394: if (state->packlen == 0) {
1395: if (sshbuf_len(state->input) < 4 + 1)
1396: return 0; /* packet is incomplete */
1397: state->packlen = PEEK_U32(cp);
1398: if (state->packlen < 4 + 1 ||
1399: state->packlen > PACKET_MAX_SIZE)
1400: return SSH_ERR_MESSAGE_INCOMPLETE;
1401: }
1402: need = state->packlen + 4;
1403: if (sshbuf_len(state->input) < need)
1404: return 0; /* packet is incomplete */
1405: sshbuf_reset(state->incoming_packet);
1406: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1407: state->packlen)) != 0 ||
1408: (r = sshbuf_consume(state->input, need)) != 0 ||
1409: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1410: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1411: return r;
1412: if (ssh_packet_log_type(*typep))
1413: debug3("%s: type %u", __func__, *typep);
1414: /* sshbuf_dump(state->incoming_packet, stderr); */
1415: /* reset for next packet */
1416: state->packlen = 0;
1417: return r;
1418: }
1419:
1.201 markus 1420: int
1421: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1422: {
1.201 markus 1423: struct session_state *state = ssh->state;
1.40 markus 1424: u_int padlen, need;
1.231 djm 1425: u_char *cp;
1.201 markus 1426: u_int maclen, aadlen = 0, authlen = 0, block_size;
1427: struct sshenc *enc = NULL;
1428: struct sshmac *mac = NULL;
1429: struct sshcomp *comp = NULL;
1.200 markus 1430: int r;
1.201 markus 1431:
1.242 markus 1432: if (state->mux)
1433: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1434:
1.201 markus 1435: *typep = SSH_MSG_NONE;
1436:
1437: if (state->packet_discard)
1438: return 0;
1439:
1440: if (state->newkeys[MODE_IN] != NULL) {
1441: enc = &state->newkeys[MODE_IN]->enc;
1442: mac = &state->newkeys[MODE_IN]->mac;
1443: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1444: /* disable mac for authenticated encryption */
1445: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1446: mac = NULL;
1.25 markus 1447: }
1448: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1449: block_size = enc ? enc->block_size : 8;
1.180 markus 1450: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1451:
1.201 markus 1452: if (aadlen && state->packlen == 0) {
1.235 djm 1453: if (cipher_get_length(state->receive_context,
1.201 markus 1454: &state->packlen, state->p_read.seqnr,
1455: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1456: return 0;
1457: if (state->packlen < 1 + 4 ||
1458: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1459: #ifdef PACKET_DEBUG
1.201 markus 1460: sshbuf_dump(state->input, stderr);
1.178 markus 1461: #endif
1.201 markus 1462: logit("Bad packet length %u.", state->packlen);
1463: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1464: return r;
1.217 djm 1465: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1466: }
1.201 markus 1467: sshbuf_reset(state->incoming_packet);
1468: } else if (state->packlen == 0) {
1.25 markus 1469: /*
1470: * check if input size is less than the cipher block size,
1471: * decrypt first block and extract length of incoming packet
1472: */
1.201 markus 1473: if (sshbuf_len(state->input) < block_size)
1474: return 0;
1475: sshbuf_reset(state->incoming_packet);
1476: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1477: &cp)) != 0)
1478: goto out;
1.235 djm 1479: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1480: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1481: block_size, 0, 0)) != 0)
1482: goto out;
1483: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1484: if (state->packlen < 1 + 4 ||
1485: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1486: #ifdef PACKET_DEBUG
1.201 markus 1487: fprintf(stderr, "input: \n");
1488: sshbuf_dump(state->input, stderr);
1489: fprintf(stderr, "incoming_packet: \n");
1490: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1491: #endif
1.201 markus 1492: logit("Bad packet length %u.", state->packlen);
1.234 markus 1493: return ssh_packet_start_discard(ssh, enc, mac, 0,
1494: PACKET_MAX_SIZE);
1.25 markus 1495: }
1.201 markus 1496: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1497: goto out;
1.25 markus 1498: }
1.201 markus 1499: DBG(debug("input: packet len %u", state->packlen+4));
1500:
1.178 markus 1501: if (aadlen) {
1502: /* only the payload is encrypted */
1.201 markus 1503: need = state->packlen;
1.178 markus 1504: } else {
1505: /*
1506: * the payload size and the payload are encrypted, but we
1507: * have a partial packet of block_size bytes
1508: */
1.201 markus 1509: need = 4 + state->packlen - block_size;
1.178 markus 1510: }
1.180 markus 1511: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1512: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1513: if (need % block_size != 0) {
1514: logit("padding error: need %d block %d mod %d",
1.25 markus 1515: need, block_size, need % block_size);
1.234 markus 1516: return ssh_packet_start_discard(ssh, enc, mac, 0,
1517: PACKET_MAX_SIZE - block_size);
1.158 markus 1518: }
1.25 markus 1519: /*
1520: * check if the entire packet has been received and
1.178 markus 1521: * decrypt into incoming_packet:
1522: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1523: * 'need' bytes are encrypted, followed by either
1524: * 'authlen' bytes of authentication tag or
1.178 markus 1525: * 'maclen' bytes of message authentication code.
1.25 markus 1526: */
1.201 markus 1527: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1528: return 0; /* packet is incomplete */
1.25 markus 1529: #ifdef PACKET_DEBUG
1530: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1531: sshbuf_dump(state->input, stderr);
1.25 markus 1532: #endif
1.231 djm 1533: /* EtM: check mac over encrypted input */
1.201 markus 1534: if (mac && mac->enabled && mac->etm) {
1.231 djm 1535: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1536: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1537: sshbuf_ptr(state->input) + aadlen + need + authlen,
1538: maclen)) != 0) {
1539: if (r == SSH_ERR_MAC_INVALID)
1540: logit("Corrupted MAC on input.");
1.201 markus 1541: goto out;
1.231 djm 1542: }
1.201 markus 1543: }
1544: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1545: &cp)) != 0)
1546: goto out;
1.235 djm 1547: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1548: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1549: goto out;
1550: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1551: goto out;
1.29 markus 1552: if (mac && mac->enabled) {
1.231 djm 1553: /* Not EtM: check MAC over cleartext */
1554: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1555: sshbuf_ptr(state->incoming_packet),
1556: sshbuf_len(state->incoming_packet),
1557: sshbuf_ptr(state->input), maclen)) != 0) {
1558: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1559: goto out;
1.159 markus 1560: logit("Corrupted MAC on input.");
1.247 markus 1561: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1562: return SSH_ERR_INTERNAL_ERROR;
1563: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1564: sshbuf_len(state->incoming_packet),
1.247 markus 1565: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1566: }
1.231 djm 1567: /* Remove MAC from input buffer */
1.201 markus 1568: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1569: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1570: goto out;
1.25 markus 1571: }
1.77 djm 1572: if (seqnr_p != NULL)
1.201 markus 1573: *seqnr_p = state->p_read.seqnr;
1574: if (++state->p_read.seqnr == 0)
1.106 itojun 1575: logit("incoming seqnr wraps around");
1.201 markus 1576: if (++state->p_read.packets == 0)
1577: if (!(ssh->compat & SSH_BUG_NOREKEY))
1578: return SSH_ERR_NEED_REKEY;
1579: state->p_read.blocks += (state->packlen + 4) / block_size;
1580: state->p_read.bytes += state->packlen + 4;
1.25 markus 1581:
1582: /* get padlen */
1.201 markus 1583: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1584: DBG(debug("input: padlen %d", padlen));
1.205 djm 1585: if (padlen < 4) {
1586: if ((r = sshpkt_disconnect(ssh,
1587: "Corrupted padlen %d on input.", padlen)) != 0 ||
1588: (r = ssh_packet_write_wait(ssh)) != 0)
1589: return r;
1590: return SSH_ERR_CONN_CORRUPT;
1591: }
1.25 markus 1592:
1593: /* skip packet size + padlen, discard padding */
1.201 markus 1594: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1595: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1596: goto out;
1.25 markus 1597:
1.201 markus 1598: DBG(debug("input: len before de-compress %zd",
1599: sshbuf_len(state->incoming_packet)));
1.25 markus 1600: if (comp && comp->enabled) {
1.201 markus 1601: sshbuf_reset(state->compression_buffer);
1602: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1603: state->compression_buffer)) != 0)
1604: goto out;
1605: sshbuf_reset(state->incoming_packet);
1606: if ((r = sshbuf_putb(state->incoming_packet,
1607: state->compression_buffer)) != 0)
1608: goto out;
1609: DBG(debug("input: len after de-compress %zd",
1610: sshbuf_len(state->incoming_packet)));
1.25 markus 1611: }
1612: /*
1613: * get packet type, implies consume.
1614: * return length of payload (without type field)
1615: */
1.201 markus 1616: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1617: goto out;
1.226 djm 1618: if (ssh_packet_log_type(*typep))
1619: debug3("receive packet: type %u", *typep);
1.205 djm 1620: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1621: if ((r = sshpkt_disconnect(ssh,
1622: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1623: (r = ssh_packet_write_wait(ssh)) != 0)
1624: return r;
1625: return SSH_ERR_PROTOCOL_ERROR;
1626: }
1.243 djm 1627: if (state->hook_in != NULL &&
1628: (r = state->hook_in(ssh, state->incoming_packet, typep,
1629: state->hook_in_ctx)) != 0)
1630: return r;
1.238 markus 1631: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1632: r = ssh_packet_enable_delayed_compress(ssh);
1633: else
1634: r = 0;
1.25 markus 1635: #ifdef PACKET_DEBUG
1.201 markus 1636: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1637: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1638: #endif
1.62 markus 1639: /* reset for next packet */
1.201 markus 1640: state->packlen = 0;
1.228 djm 1641:
1642: /* do we need to rekey? */
1643: if (ssh_packet_need_rekeying(ssh, 0)) {
1644: debug3("%s: rekex triggered", __func__);
1645: if ((r = kex_start_rekex(ssh)) != 0)
1646: return r;
1647: }
1.201 markus 1648: out:
1649: return r;
1.25 markus 1650: }
1651:
1652: int
1.201 markus 1653: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1654: {
1.201 markus 1655: struct session_state *state = ssh->state;
1.96 deraadt 1656: u_int reason, seqnr;
1.201 markus 1657: int r;
1658: u_char *msg;
1.62 markus 1659:
1.25 markus 1660: for (;;) {
1.201 markus 1661: msg = NULL;
1.249 djm 1662: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1663: if (r != 0)
1664: return r;
1665: if (*typep) {
1666: state->keep_alive_timeouts = 0;
1667: DBG(debug("received packet type %d", *typep));
1668: }
1669: switch (*typep) {
1670: case SSH2_MSG_IGNORE:
1671: debug3("Received SSH2_MSG_IGNORE");
1672: break;
1673: case SSH2_MSG_DEBUG:
1674: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1675: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1676: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1677: free(msg);
1.201 markus 1678: return r;
1.48 stevesk 1679: }
1.249 djm 1680: debug("Remote: %.900s", msg);
1681: free(msg);
1682: break;
1683: case SSH2_MSG_DISCONNECT:
1684: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1685: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1686: return r;
1687: /* Ignore normal client exit notifications */
1688: do_log2(ssh->state->server_side &&
1689: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1690: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1691: "Received disconnect from %s port %d:"
1692: "%u: %.400s", ssh_remote_ipaddr(ssh),
1693: ssh_remote_port(ssh), reason, msg);
1694: free(msg);
1695: return SSH_ERR_DISCONNECTED;
1696: case SSH2_MSG_UNIMPLEMENTED:
1697: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1698: return r;
1699: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1700: seqnr);
1701: break;
1702: default:
1703: return 0;
1.25 markus 1704: }
1705: }
1706: }
1707:
1.16 markus 1708: /*
1709: * Buffers the given amount of input characters. This is intended to be used
1710: * together with packet_read_poll.
1711: */
1.1 deraadt 1712:
1.204 djm 1713: int
1.201 markus 1714: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1715: {
1.201 markus 1716: struct session_state *state = ssh->state;
1717: int r;
1718:
1719: if (state->packet_discard) {
1720: state->keep_alive_timeouts = 0; /* ?? */
1721: if (len >= state->packet_discard) {
1722: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1723: return r;
1.201 markus 1724: }
1725: state->packet_discard -= len;
1.204 djm 1726: return 0;
1.159 markus 1727: }
1.201 markus 1728: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1729: return r;
1730:
1731: return 0;
1.28 markus 1732: }
1733:
1734: int
1.201 markus 1735: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1736: {
1.201 markus 1737: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1738: }
1739:
1.16 markus 1740: /*
1741: * Sends a diagnostic message from the server to the client. This message
1742: * can be sent at any time (but not while constructing another message). The
1743: * message is printed immediately, but only if the client is being executed
1744: * in verbose mode. These messages are primarily intended to ease debugging
1745: * authentication problems. The length of the formatted message must not
1.205 djm 1746: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1747: */
1.2 provos 1748: void
1.201 markus 1749: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1750: {
1.14 markus 1751: char buf[1024];
1752: va_list args;
1.201 markus 1753: int r;
1.39 markus 1754:
1.249 djm 1755: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1756: return;
1.14 markus 1757:
1758: va_start(args, fmt);
1759: vsnprintf(buf, sizeof(buf), fmt, args);
1760: va_end(args);
1761:
1.249 djm 1762: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1763: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1764: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1765: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1766: (r = sshpkt_send(ssh)) != 0 ||
1767: (r = ssh_packet_write_wait(ssh)) != 0)
1.205 djm 1768: fatal("%s: %s", __func__, ssh_err(r));
1769: }
1770:
1.245 djm 1771: static void
1772: fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1773: {
1774: snprintf(s, l, "%.200s%s%s port %d",
1775: ssh->log_preamble ? ssh->log_preamble : "",
1776: ssh->log_preamble ? " " : "",
1777: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1778: }
1779:
1.205 djm 1780: /*
1781: * Pretty-print connection-terminating errors and exit.
1782: */
1783: void
1784: sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
1785: {
1.245 djm 1786: char remote_id[512];
1787:
1788: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1789:
1.205 djm 1790: switch (r) {
1791: case SSH_ERR_CONN_CLOSED:
1.245 djm 1792: logdie("Connection closed by %s", remote_id);
1.205 djm 1793: case SSH_ERR_CONN_TIMEOUT:
1.245 djm 1794: logdie("Connection %s %s timed out",
1795: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1796: case SSH_ERR_DISCONNECTED:
1.245 djm 1797: logdie("Disconnected from %s", remote_id);
1.212 djm 1798: case SSH_ERR_SYSTEM_ERROR:
1.232 dtucker 1799: if (errno == ECONNRESET)
1.245 djm 1800: logdie("Connection reset by %s", remote_id);
1.213 djm 1801: /* FALLTHROUGH */
1802: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1803: case SSH_ERR_NO_MAC_ALG_MATCH:
1804: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1805: case SSH_ERR_NO_KEX_ALG_MATCH:
1806: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1807: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.245 djm 1808: logdie("Unable to negotiate with %s: %s. "
1809: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1810: ssh->kex->failed_choice);
1.212 djm 1811: }
1812: /* FALLTHROUGH */
1.205 djm 1813: default:
1.245 djm 1814: logdie("%s%sConnection %s %s: %s",
1.205 djm 1815: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 1816: ssh->state->server_side ? "from" : "to",
1.245 djm 1817: remote_id, ssh_err(r));
1.205 djm 1818: }
1.1 deraadt 1819: }
1820:
1.16 markus 1821: /*
1822: * Logs the error plus constructs and sends a disconnect packet, closes the
1823: * connection, and exits. This function never returns. The error message
1824: * should not contain a newline. The length of the formatted message must
1825: * not exceed 1024 bytes.
1826: */
1.2 provos 1827: void
1.201 markus 1828: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1829: {
1.245 djm 1830: char buf[1024], remote_id[512];
1.14 markus 1831: va_list args;
1832: static int disconnecting = 0;
1.201 markus 1833: int r;
1.97 deraadt 1834:
1.14 markus 1835: if (disconnecting) /* Guard against recursive invocations. */
1836: fatal("packet_disconnect called recursively.");
1837: disconnecting = 1;
1838:
1.16 markus 1839: /*
1840: * Format the message. Note that the caller must make sure the
1841: * message is of limited size.
1842: */
1.245 djm 1843: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1844: va_start(args, fmt);
1845: vsnprintf(buf, sizeof(buf), fmt, args);
1846: va_end(args);
1847:
1.99 markus 1848: /* Display the error locally */
1.245 djm 1849: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1850:
1.205 djm 1851: /*
1852: * Send the disconnect message to the other side, and wait
1853: * for it to get sent.
1854: */
1855: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1856: sshpkt_fatal(ssh, __func__, r);
1857:
1858: if ((r = ssh_packet_write_wait(ssh)) != 0)
1859: sshpkt_fatal(ssh, __func__, r);
1.14 markus 1860:
1861: /* Close the connection. */
1.201 markus 1862: ssh_packet_close(ssh);
1.112 markus 1863: cleanup_exit(255);
1.1 deraadt 1864: }
1865:
1.205 djm 1866: /*
1867: * Checks if there is any buffered output, and tries to write some of
1868: * the output.
1869: */
1870: int
1.201 markus 1871: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1872: {
1.201 markus 1873: struct session_state *state = ssh->state;
1874: int len = sshbuf_len(state->output);
1.222 markus 1875: int r;
1.97 deraadt 1876:
1.14 markus 1877: if (len > 0) {
1.222 markus 1878: len = write(state->connection_out,
1879: sshbuf_ptr(state->output), len);
1.156 djm 1880: if (len == -1) {
1881: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1882: return 0;
1883: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1884: }
1.222 markus 1885: if (len == 0)
1.205 djm 1886: return SSH_ERR_CONN_CLOSED;
1.201 markus 1887: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1888: return r;
1.14 markus 1889: }
1.205 djm 1890: return 0;
1.1 deraadt 1891: }
1892:
1.16 markus 1893: /*
1894: * Calls packet_write_poll repeatedly until all pending output data has been
1895: * written.
1896: */
1.205 djm 1897: int
1.201 markus 1898: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1899: {
1.56 millert 1900: fd_set *setp;
1.205 djm 1901: int ret, r, ms_remain = 0;
1.154 dtucker 1902: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1903: struct session_state *state = ssh->state;
1.56 millert 1904:
1.214 deraadt 1905: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1906: NFDBITS), sizeof(fd_mask));
1.201 markus 1907: if (setp == NULL)
1.205 djm 1908: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1909: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1910: free(setp);
1.215 djm 1911: return r;
1.216 gsoares 1912: }
1.201 markus 1913: while (ssh_packet_have_data_to_write(ssh)) {
1914: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1915: NFDBITS) * sizeof(fd_mask));
1.201 markus 1916: FD_SET(state->connection_out, setp);
1.154 dtucker 1917:
1.201 markus 1918: if (state->packet_timeout_ms > 0) {
1919: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1920: timeoutp = &timeout;
1921: }
1922: for (;;) {
1.201 markus 1923: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1924: ms_to_timeval(&timeout, ms_remain);
1925: gettimeofday(&start, NULL);
1926: }
1.201 markus 1927: if ((ret = select(state->connection_out + 1,
1.161 andreas 1928: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1929: break;
1.161 andreas 1930: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1931: break;
1.201 markus 1932: if (state->packet_timeout_ms == -1)
1.154 dtucker 1933: continue;
1934: ms_subtract_diff(&start, &ms_remain);
1935: if (ms_remain <= 0) {
1936: ret = 0;
1937: break;
1938: }
1939: }
1940: if (ret == 0) {
1.205 djm 1941: free(setp);
1942: return SSH_ERR_CONN_TIMEOUT;
1943: }
1944: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1945: free(setp);
1946: return r;
1.154 dtucker 1947: }
1.14 markus 1948: }
1.186 djm 1949: free(setp);
1.205 djm 1950: return 0;
1.1 deraadt 1951: }
1952:
1953: /* Returns true if there is buffered data to write to the connection. */
1954:
1.2 provos 1955: int
1.201 markus 1956: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 1957: {
1.201 markus 1958: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 1959: }
1960:
1961: /* Returns true if there is not too much data to write to the connection. */
1962:
1.2 provos 1963: int
1.201 markus 1964: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 1965: {
1.201 markus 1966: if (ssh->state->interactive_mode)
1967: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 1968: else
1.201 markus 1969: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 1970: }
1971:
1.201 markus 1972: void
1973: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 1974: {
1.201 markus 1975: if (!ssh_packet_connection_is_on_socket(ssh))
1.101 markus 1976: return;
1.201 markus 1977: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 1978: case AF_INET:
1979: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 1980: if (setsockopt(ssh->state->connection_in,
1.173 djm 1981: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
1982: error("setsockopt IP_TOS %d: %.100s:",
1983: tos, strerror(errno));
1984: break;
1985: case AF_INET6:
1986: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 1987: if (setsockopt(ssh->state->connection_in,
1.173 djm 1988: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
1989: error("setsockopt IPV6_TCLASS %d: %.100s:",
1990: tos, strerror(errno));
1991: break;
1992: }
1.101 markus 1993: }
1994:
1.1 deraadt 1995: /* Informs that the current session is interactive. Sets IP flags for that. */
1996:
1.2 provos 1997: void
1.201 markus 1998: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 1999: {
1.201 markus 2000: struct session_state *state = ssh->state;
2001:
2002: if (state->set_interactive_called)
1.43 markus 2003: return;
1.201 markus 2004: state->set_interactive_called = 1;
1.1 deraadt 2005:
1.14 markus 2006: /* Record that we are in interactive mode. */
1.201 markus 2007: state->interactive_mode = interactive;
1.1 deraadt 2008:
1.19 markus 2009: /* Only set socket options if using a socket. */
1.201 markus 2010: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2011: return;
1.201 markus 2012: set_nodelay(state->connection_in);
2013: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2014: qos_bulk);
1.1 deraadt 2015: }
2016:
2017: /* Returns true if the current connection is interactive. */
2018:
1.2 provos 2019: int
1.201 markus 2020: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2021: {
1.201 markus 2022: return ssh->state->interactive_mode;
1.12 markus 2023: }
2024:
1.113 deraadt 2025: int
1.201 markus 2026: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2027: {
1.201 markus 2028: struct session_state *state = ssh->state;
2029:
2030: if (state->set_maxsize_called) {
1.106 itojun 2031: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2032: state->max_packet_size, s);
1.14 markus 2033: return -1;
2034: }
2035: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2036: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2037: return -1;
2038: }
1.201 markus 2039: state->set_maxsize_called = 1;
1.66 markus 2040: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2041: state->max_packet_size = s;
1.14 markus 2042: return s;
1.53 markus 2043: }
2044:
1.161 andreas 2045: int
1.201 markus 2046: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2047: {
1.201 markus 2048: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2049: }
2050:
2051: void
1.201 markus 2052: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2053: {
1.201 markus 2054: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2055: }
2056:
2057: u_int
1.201 markus 2058: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2059: {
1.201 markus 2060: return ssh->state->max_packet_size;
1.71 markus 2061: }
2062:
1.53 markus 2063: /*
2064: * 9.2. Ignored Data Message
1.61 markus 2065: *
1.53 markus 2066: * byte SSH_MSG_IGNORE
2067: * string data
1.61 markus 2068: *
1.53 markus 2069: * All implementations MUST understand (and ignore) this message at any
2070: * time (after receiving the protocol version). No implementation is
2071: * required to send them. This message can be used as an additional
2072: * protection measure against advanced traffic analysis techniques.
2073: */
1.54 markus 2074: void
1.201 markus 2075: ssh_packet_send_ignore(struct ssh *ssh, int nbytes)
1.54 markus 2076: {
1.115 avsm 2077: u_int32_t rnd = 0;
1.201 markus 2078: int r, i;
1.54 markus 2079:
1.249 djm 2080: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
1.201 markus 2081: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2082: fatal("%s: %s", __func__, ssh_err(r));
1.75 deraadt 2083: for (i = 0; i < nbytes; i++) {
1.53 markus 2084: if (i % 4 == 0)
1.115 avsm 2085: rnd = arc4random();
1.201 markus 2086: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2087: fatal("%s: %s", __func__, ssh_err(r));
1.115 avsm 2088: rnd >>= 8;
1.53 markus 2089: }
1.105 markus 2090: }
2091:
2092: void
1.244 dtucker 2093: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2094: {
1.244 dtucker 2095: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2096: (unsigned int)seconds);
1.201 markus 2097: ssh->state->rekey_limit = bytes;
2098: ssh->state->rekey_interval = seconds;
1.184 dtucker 2099: }
2100:
2101: time_t
1.201 markus 2102: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2103: {
2104: time_t seconds;
2105:
1.201 markus 2106: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2107: monotime();
1.185 dtucker 2108: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2109: }
2110:
2111: void
1.201 markus 2112: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2113: {
1.201 markus 2114: ssh->state->server_side = 1;
1.118 markus 2115: }
2116:
2117: void
1.201 markus 2118: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2119: {
1.201 markus 2120: ssh->state->after_authentication = 1;
1.161 andreas 2121: }
2122:
2123: void *
1.201 markus 2124: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2125: {
1.201 markus 2126: return (void *)ssh->state->input;
1.161 andreas 2127: }
2128:
2129: void *
1.201 markus 2130: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2131: {
1.201 markus 2132: return (void *)ssh->state->output;
1.166 andreas 2133: }
2134:
1.196 markus 2135: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2136: static int
2137: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2138: {
1.239 djm 2139: int r;
1.196 markus 2140:
2141: debug("%s: called", __func__);
2142: /* This was set in net child, but is not visible in user child */
1.201 markus 2143: ssh->state->after_authentication = 1;
2144: ssh->state->rekeying = 0;
1.239 djm 2145: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2146: return r;
1.201 markus 2147: return 0;
2148: }
2149:
2150: /* Packet state (de-)serialization for privsep */
2151:
2152: /* turn kex into a blob for packet state serialization */
2153: static int
2154: kex_to_blob(struct sshbuf *m, struct kex *kex)
2155: {
2156: int r;
2157:
2158: if ((r = sshbuf_put_string(m, kex->session_id,
2159: kex->session_id_len)) != 0 ||
2160: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2161: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2162: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2163: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2164: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2165: (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2166: (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2167: (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2168: return r;
2169: return 0;
2170: }
2171:
2172: /* turn key exchange results into a blob for packet state serialization */
2173: static int
2174: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2175: {
2176: struct sshbuf *b;
2177: struct sshcipher_ctx *cc;
2178: struct sshcomp *comp;
2179: struct sshenc *enc;
2180: struct sshmac *mac;
2181: struct newkeys *newkey;
2182: int r;
2183:
2184: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2185: return SSH_ERR_INTERNAL_ERROR;
2186: enc = &newkey->enc;
2187: mac = &newkey->mac;
2188: comp = &newkey->comp;
1.235 djm 2189: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2190: ssh->state->receive_context;
1.201 markus 2191: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2192: return r;
2193: if ((b = sshbuf_new()) == NULL)
2194: return SSH_ERR_ALLOC_FAIL;
2195: /* The cipher struct is constant and shared, you export pointer */
2196: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2197: (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2198: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2199: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2200: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2201: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2202: goto out;
2203: if (cipher_authlen(enc->cipher) == 0) {
2204: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2205: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2206: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2207: goto out;
2208: }
2209: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2210: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2211: goto out;
2212: r = sshbuf_put_stringb(m, b);
2213: out:
1.221 mmcc 2214: sshbuf_free(b);
1.201 markus 2215: return r;
2216: }
2217:
2218: /* serialize packet state into a blob */
2219: int
2220: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2221: {
2222: struct session_state *state = ssh->state;
2223: u_char *p;
2224: size_t slen, rlen;
1.249 djm 2225: int r;
1.201 markus 2226:
1.249 djm 2227: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2228: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2229: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2230: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2231: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2232: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2233: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2234: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2235: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2236: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2237: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2238: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
2239: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0)
2240: return r;
1.201 markus 2241:
1.235 djm 2242: slen = cipher_get_keycontext(state->send_context, NULL);
2243: rlen = cipher_get_keycontext(state->receive_context, NULL);
1.201 markus 2244: if ((r = sshbuf_put_u32(m, slen)) != 0 ||
2245: (r = sshbuf_reserve(m, slen, &p)) != 0)
2246: return r;
1.235 djm 2247: if (cipher_get_keycontext(state->send_context, p) != (int)slen)
1.201 markus 2248: return SSH_ERR_INTERNAL_ERROR;
2249: if ((r = sshbuf_put_u32(m, rlen)) != 0 ||
2250: (r = sshbuf_reserve(m, rlen, &p)) != 0)
2251: return r;
1.235 djm 2252: if (cipher_get_keycontext(state->receive_context, p) != (int)rlen)
1.201 markus 2253: return SSH_ERR_INTERNAL_ERROR;
1.239 djm 2254: if ((r = sshbuf_put_stringb(m, state->input)) != 0 ||
1.201 markus 2255: (r = sshbuf_put_stringb(m, state->output)) != 0)
2256: return r;
2257:
2258: return 0;
2259: }
2260:
2261: /* restore key exchange results from blob for packet state de-serialization */
2262: static int
2263: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2264: {
2265: struct sshbuf *b = NULL;
2266: struct sshcomp *comp;
2267: struct sshenc *enc;
2268: struct sshmac *mac;
2269: struct newkeys *newkey = NULL;
2270: size_t keylen, ivlen, maclen;
2271: int r;
2272:
2273: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2274: r = SSH_ERR_ALLOC_FAIL;
2275: goto out;
2276: }
2277: if ((r = sshbuf_froms(m, &b)) != 0)
2278: goto out;
2279: #ifdef DEBUG_PK
2280: sshbuf_dump(b, stderr);
2281: #endif
2282: enc = &newkey->enc;
2283: mac = &newkey->mac;
2284: comp = &newkey->comp;
2285:
2286: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2287: (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2288: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2289: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2290: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2291: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2292: goto out;
2293: if (cipher_authlen(enc->cipher) == 0) {
2294: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2295: goto out;
2296: if ((r = mac_setup(mac, mac->name)) != 0)
2297: goto out;
2298: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2299: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2300: goto out;
2301: if (maclen > mac->key_len) {
2302: r = SSH_ERR_INVALID_FORMAT;
2303: goto out;
2304: }
2305: mac->key_len = maclen;
2306: }
2307: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2308: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2309: goto out;
2310: if (enc->name == NULL ||
2311: cipher_by_name(enc->name) != enc->cipher) {
2312: r = SSH_ERR_INVALID_FORMAT;
2313: goto out;
2314: }
2315: if (sshbuf_len(b) != 0) {
2316: r = SSH_ERR_INVALID_FORMAT;
2317: goto out;
2318: }
2319: enc->key_len = keylen;
2320: enc->iv_len = ivlen;
2321: ssh->kex->newkeys[mode] = newkey;
2322: newkey = NULL;
2323: r = 0;
2324: out:
1.219 mmcc 2325: free(newkey);
1.221 mmcc 2326: sshbuf_free(b);
1.201 markus 2327: return r;
2328: }
2329:
2330: /* restore kex from blob for packet state de-serialization */
2331: static int
2332: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2333: {
2334: struct kex *kex;
2335: int r;
2336:
2337: if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2338: (kex->my = sshbuf_new()) == NULL ||
2339: (kex->peer = sshbuf_new()) == NULL) {
2340: r = SSH_ERR_ALLOC_FAIL;
2341: goto out;
2342: }
2343: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2344: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2345: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2346: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2347: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2348: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2349: (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2350: (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2351: (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2352: goto out;
2353: kex->server = 1;
2354: kex->done = 1;
2355: r = 0;
2356: out:
2357: if (r != 0 || kexp == NULL) {
2358: if (kex != NULL) {
1.221 mmcc 2359: sshbuf_free(kex->my);
2360: sshbuf_free(kex->peer);
1.201 markus 2361: free(kex);
2362: }
2363: if (kexp != NULL)
2364: *kexp = NULL;
2365: } else {
2366: *kexp = kex;
2367: }
2368: return r;
2369: }
2370:
2371: /*
2372: * Restore packet state from content of blob 'm' (de-serialization).
2373: * Note that 'm' will be partially consumed on parsing or any other errors.
2374: */
2375: int
2376: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2377: {
2378: struct session_state *state = ssh->state;
1.249 djm 2379: const u_char *keyin, *keyout, *input, *output;
2380: size_t rlen, slen, ilen, olen;
1.201 markus 2381: int r;
2382:
1.249 djm 2383: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2384: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2385: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2386: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2387: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2388: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2389: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2390: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2391: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2392: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2393: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2394: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2395: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2396: return r;
2397: /*
2398: * We set the time here so that in post-auth privsep slave we
2399: * count from the completion of the authentication.
2400: */
2401: state->rekey_time = monotime();
2402: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2403: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2404: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2405: return r;
2406:
1.201 markus 2407: if ((r = sshbuf_get_string_direct(m, &keyout, &slen)) != 0 ||
2408: (r = sshbuf_get_string_direct(m, &keyin, &rlen)) != 0)
2409: return r;
1.235 djm 2410: if (cipher_get_keycontext(state->send_context, NULL) != (int)slen ||
2411: cipher_get_keycontext(state->receive_context, NULL) != (int)rlen)
1.201 markus 2412: return SSH_ERR_INVALID_FORMAT;
1.235 djm 2413: cipher_set_keycontext(state->send_context, keyout);
2414: cipher_set_keycontext(state->receive_context, keyin);
1.201 markus 2415:
1.239 djm 2416: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2417: return r;
2418:
2419: sshbuf_reset(state->input);
2420: sshbuf_reset(state->output);
2421: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2422: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2423: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2424: (r = sshbuf_put(state->output, output, olen)) != 0)
2425: return r;
2426:
2427: if (sshbuf_len(m))
2428: return SSH_ERR_INVALID_FORMAT;
2429: debug3("%s: done", __func__);
2430: return 0;
2431: }
2432:
2433: /* NEW API */
2434:
2435: /* put data to the outgoing packet */
2436:
2437: int
2438: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2439: {
2440: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2441: }
2442:
2443: int
2444: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2445: {
2446: return sshbuf_putb(ssh->state->outgoing_packet, b);
2447: }
2448:
2449: int
2450: sshpkt_put_u8(struct ssh *ssh, u_char val)
2451: {
2452: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2453: }
2454:
2455: int
2456: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2457: {
2458: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2459: }
2460:
2461: int
2462: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2463: {
2464: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2465: }
2466:
2467: int
2468: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2469: {
2470: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2471: }
2472:
2473: int
2474: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2475: {
2476: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2477: }
2478:
2479: int
2480: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2481: {
2482: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2483: }
2484:
1.211 djm 2485: #ifdef WITH_OPENSSL
1.201 markus 2486: int
2487: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2488: {
2489: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2490: }
2491:
2492:
2493: int
2494: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2495: {
2496: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2497: }
1.211 djm 2498: #endif /* WITH_OPENSSL */
1.201 markus 2499:
2500: /* fetch data from the incoming packet */
2501:
2502: int
2503: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2504: {
2505: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2506: }
2507:
2508: int
2509: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2510: {
2511: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2512: }
2513:
2514: int
2515: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2516: {
2517: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2518: }
2519:
2520: int
2521: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2522: {
2523: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2524: }
2525:
2526: int
2527: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2528: {
2529: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2530: }
2531:
2532: int
2533: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2534: {
2535: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2536: }
2537:
2538: int
2539: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2540: {
2541: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2542: }
2543:
1.211 djm 2544: #ifdef WITH_OPENSSL
1.201 markus 2545: int
2546: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2547: {
2548: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2549: }
2550:
2551:
2552: int
2553: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2554: {
2555: return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2556: }
1.211 djm 2557: #endif /* WITH_OPENSSL */
1.201 markus 2558:
2559: int
2560: sshpkt_get_end(struct ssh *ssh)
2561: {
2562: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2563: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2564: return 0;
2565: }
2566:
2567: const u_char *
2568: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2569: {
2570: if (lenp != NULL)
2571: *lenp = sshbuf_len(ssh->state->incoming_packet);
2572: return sshbuf_ptr(ssh->state->incoming_packet);
2573: }
2574:
2575: /* start a new packet */
2576:
2577: int
2578: sshpkt_start(struct ssh *ssh, u_char type)
2579: {
1.249 djm 2580: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2581:
2582: DBG(debug("packet_start[%d]", type));
1.249 djm 2583: memset(buf, 0, sizeof(buf));
2584: buf[sizeof(buf) - 1] = type;
1.201 markus 2585: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2586: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2587: }
2588:
1.242 markus 2589: static int
2590: ssh_packet_send_mux(struct ssh *ssh)
2591: {
2592: struct session_state *state = ssh->state;
2593: u_char type, *cp;
2594: size_t len;
2595: int r;
2596:
2597: if (ssh->kex)
2598: return SSH_ERR_INTERNAL_ERROR;
2599: len = sshbuf_len(state->outgoing_packet);
2600: if (len < 6)
2601: return SSH_ERR_INTERNAL_ERROR;
2602: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2603: type = cp[5];
2604: if (ssh_packet_log_type(type))
2605: debug3("%s: type %u", __func__, type);
2606: /* drop everything, but the connection protocol */
2607: if (type >= SSH2_MSG_CONNECTION_MIN &&
2608: type <= SSH2_MSG_CONNECTION_MAX) {
2609: POKE_U32(cp, len - 4);
2610: if ((r = sshbuf_putb(state->output,
2611: state->outgoing_packet)) != 0)
2612: return r;
2613: /* sshbuf_dump(state->output, stderr); */
2614: }
2615: sshbuf_reset(state->outgoing_packet);
2616: return 0;
2617: }
2618:
1.201 markus 2619: /* send it */
2620:
2621: int
2622: sshpkt_send(struct ssh *ssh)
2623: {
1.242 markus 2624: if (ssh->state && ssh->state->mux)
2625: return ssh_packet_send_mux(ssh);
1.249 djm 2626: return ssh_packet_send2(ssh);
1.201 markus 2627: }
2628:
2629: int
2630: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2631: {
2632: char buf[1024];
2633: va_list args;
2634: int r;
2635:
2636: va_start(args, fmt);
2637: vsnprintf(buf, sizeof(buf), fmt, args);
2638: va_end(args);
2639:
1.249 djm 2640: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2641: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2642: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2643: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2644: (r = sshpkt_send(ssh)) != 0)
2645: return r;
1.201 markus 2646: return 0;
2647: }
2648:
2649: /* roundup current message to pad bytes */
2650: int
2651: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2652: {
2653: ssh->state->extra_pad = pad;
2654: return 0;
1.1 deraadt 2655: }
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