Annotation of src/usr.bin/ssh/packet.c, Revision 1.254
1.254 ! djm 1: /* $OpenBSD: packet.c,v 1.253 2017/05/03 21:08:09 naddy Exp $ */
1.1 deraadt 2: /*
1.15 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.35 deraadt 6: * This file contains code implementing the packet protocol and communication
7: * with the other side. This same code is used both on client and server side.
1.29 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
1.29 markus 14: *
1.25 markus 15: *
16: * SSH2 packet format added by Markus Friedl.
1.69 markus 17: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.25 markus 18: *
1.35 deraadt 19: * Redistribution and use in source and binary forms, with or without
20: * modification, are permitted provided that the following conditions
21: * are met:
22: * 1. Redistributions of source code must retain the above copyright
23: * notice, this list of conditions and the following disclaimer.
24: * 2. Redistributions in binary form must reproduce the above copyright
25: * notice, this list of conditions and the following disclaimer in the
26: * documentation and/or other materials provided with the distribution.
27: *
28: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15 deraadt 38: */
1.1 deraadt 39:
1.142 deraadt 40: #include <sys/types.h>
1.105 markus 41: #include <sys/queue.h>
1.132 stevesk 42: #include <sys/socket.h>
1.138 stevesk 43: #include <sys/time.h>
1.132 stevesk 44: #include <netinet/in.h>
1.121 stevesk 45: #include <netinet/ip.h>
1.134 stevesk 46:
1.135 stevesk 47: #include <errno.h>
1.230 djm 48: #include <netdb.h>
1.134 stevesk 49: #include <stdarg.h>
1.141 stevesk 50: #include <stdio.h>
1.140 stevesk 51: #include <stdlib.h>
1.137 stevesk 52: #include <string.h>
1.136 stevesk 53: #include <unistd.h>
1.203 deraadt 54: #include <limits.h>
1.142 deraadt 55: #include <signal.h>
1.184 dtucker 56: #include <time.h>
1.1 deraadt 57:
1.201 markus 58: #include <zlib.h>
59:
60: #include "buffer.h" /* typedefs XXX */
61: #include "key.h" /* typedefs XXX */
62:
1.1 deraadt 63: #include "xmalloc.h"
64: #include "crc32.h"
1.25 markus 65: #include "compat.h"
66: #include "ssh2.h"
1.37 markus 67: #include "cipher.h"
1.201 markus 68: #include "sshkey.h"
1.25 markus 69: #include "kex.h"
1.200 markus 70: #include "digest.h"
1.50 markus 71: #include "mac.h"
1.46 markus 72: #include "log.h"
73: #include "canohost.h"
1.87 stevesk 74: #include "misc.h"
1.198 millert 75: #include "channels.h"
1.95 markus 76: #include "ssh.h"
1.201 markus 77: #include "packet.h"
1.197 djm 78: #include "ssherr.h"
1.201 markus 79: #include "sshbuf.h"
1.25 markus 80:
81: #ifdef PACKET_DEBUG
82: #define DBG(x) x
83: #else
84: #define DBG(x)
85: #endif
86:
1.159 markus 87: #define PACKET_MAX_SIZE (256 * 1024)
88:
1.161 andreas 89: struct packet_state {
90: u_int32_t seqnr;
91: u_int32_t packets;
92: u_int64_t blocks;
93: u_int64_t bytes;
94: };
95:
96: struct packet {
97: TAILQ_ENTRY(packet) next;
98: u_char type;
1.201 markus 99: struct sshbuf *payload;
1.161 andreas 100: };
101:
102: struct session_state {
103: /*
104: * This variable contains the file descriptors used for
105: * communicating with the other side. connection_in is used for
106: * reading; connection_out for writing. These can be the same
107: * descriptor, in which case it is assumed to be a socket.
108: */
109: int connection_in;
110: int connection_out;
111:
112: /* Protocol flags for the remote side. */
113: u_int remote_protocol_flags;
1.1 deraadt 114:
1.161 andreas 115: /* Encryption context for receiving data. Only used for decryption. */
1.235 djm 116: struct sshcipher_ctx *receive_context;
1.1 deraadt 117:
1.161 andreas 118: /* Encryption context for sending data. Only used for encryption. */
1.235 djm 119: struct sshcipher_ctx *send_context;
1.14 markus 120:
1.161 andreas 121: /* Buffer for raw input data from the socket. */
1.201 markus 122: struct sshbuf *input;
1.1 deraadt 123:
1.161 andreas 124: /* Buffer for raw output data going to the socket. */
1.201 markus 125: struct sshbuf *output;
1.1 deraadt 126:
1.161 andreas 127: /* Buffer for the partial outgoing packet being constructed. */
1.201 markus 128: struct sshbuf *outgoing_packet;
1.1 deraadt 129:
1.161 andreas 130: /* Buffer for the incoming packet currently being processed. */
1.201 markus 131: struct sshbuf *incoming_packet;
1.1 deraadt 132:
1.161 andreas 133: /* Scratch buffer for packet compression/decompression. */
1.201 markus 134: struct sshbuf *compression_buffer;
135:
136: /* Incoming/outgoing compression dictionaries */
137: z_stream compression_in_stream;
138: z_stream compression_out_stream;
139: int compression_in_started;
140: int compression_out_started;
141: int compression_in_failures;
142: int compression_out_failures;
1.1 deraadt 143:
1.161 andreas 144: /*
145: * Flag indicating whether packet compression/decompression is
146: * enabled.
147: */
148: int packet_compression;
1.1 deraadt 149:
1.161 andreas 150: /* default maximum packet size */
151: u_int max_packet_size;
1.1 deraadt 152:
1.161 andreas 153: /* Flag indicating whether this module has been initialized. */
154: int initialized;
1.12 markus 155:
1.161 andreas 156: /* Set to true if the connection is interactive. */
157: int interactive_mode;
1.1 deraadt 158:
1.161 andreas 159: /* Set to true if we are the server side. */
160: int server_side;
1.1 deraadt 161:
1.161 andreas 162: /* Set to true if we are authenticated. */
163: int after_authentication;
1.118 markus 164:
1.161 andreas 165: int keep_alive_timeouts;
1.118 markus 166:
1.161 andreas 167: /* The maximum time that we will wait to send or receive a packet */
168: int packet_timeout_ms;
1.151 dtucker 169:
1.161 andreas 170: /* Session key information for Encryption and MAC */
1.201 markus 171: struct newkeys *newkeys[MODE_MAX];
1.161 andreas 172: struct packet_state p_read, p_send;
1.154 dtucker 173:
1.184 dtucker 174: /* Volume-based rekeying */
1.224 dtucker 175: u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
1.105 markus 176:
1.184 dtucker 177: /* Time-based rekeying */
1.208 markus 178: u_int32_t rekey_interval; /* how often in seconds */
1.184 dtucker 179: time_t rekey_time; /* time of last rekeying */
180:
1.161 andreas 181: /* roundup current message to extra_pad bytes */
182: u_char extra_pad;
1.95 markus 183:
1.161 andreas 184: /* XXX discard incoming data after MAC error */
185: u_int packet_discard;
1.234 markus 186: size_t packet_discard_mac_already;
1.201 markus 187: struct sshmac *packet_discard_mac;
1.71 markus 188:
1.161 andreas 189: /* Used in packet_read_poll2() */
190: u_int packlen;
1.159 markus 191:
1.165 andreas 192: /* Used in packet_send2 */
193: int rekeying;
194:
1.242 markus 195: /* Used in ssh_packet_send_mux() */
196: int mux;
197:
1.165 andreas 198: /* Used in packet_set_interactive */
199: int set_interactive_called;
200:
201: /* Used in packet_set_maxsize */
202: int set_maxsize_called;
203:
1.201 markus 204: /* One-off warning about weak ciphers */
205: int cipher_warning_done;
206:
1.243 djm 207: /* Hook for fuzzing inbound packets */
208: ssh_packet_hook_fn *hook_in;
209: void *hook_in_ctx;
210:
1.161 andreas 211: TAILQ_HEAD(, packet) outgoing;
1.105 markus 212: };
1.161 andreas 213:
1.201 markus 214: struct ssh *
215: ssh_alloc_session_state(void)
1.161 andreas 216: {
1.201 markus 217: struct ssh *ssh = NULL;
218: struct session_state *state = NULL;
1.161 andreas 219:
1.201 markus 220: if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
221: (state = calloc(1, sizeof(*state))) == NULL ||
222: (state->input = sshbuf_new()) == NULL ||
223: (state->output = sshbuf_new()) == NULL ||
224: (state->outgoing_packet = sshbuf_new()) == NULL ||
225: (state->incoming_packet = sshbuf_new()) == NULL)
226: goto fail;
227: TAILQ_INIT(&state->outgoing);
1.202 markus 228: TAILQ_INIT(&ssh->private_keys);
229: TAILQ_INIT(&ssh->public_keys);
1.201 markus 230: state->connection_in = -1;
231: state->connection_out = -1;
232: state->max_packet_size = 32768;
233: state->packet_timeout_ms = -1;
234: state->p_send.packets = state->p_read.packets = 0;
235: state->initialized = 1;
236: /*
237: * ssh_packet_send2() needs to queue packets until
238: * we've done the initial key exchange.
239: */
240: state->rekeying = 1;
241: ssh->state = state;
242: return ssh;
243: fail:
244: if (state) {
245: sshbuf_free(state->input);
246: sshbuf_free(state->output);
247: sshbuf_free(state->incoming_packet);
248: sshbuf_free(state->outgoing_packet);
249: free(state);
250: }
251: free(ssh);
252: return NULL;
1.161 andreas 253: }
1.105 markus 254:
1.243 djm 255: void
256: ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
257: {
258: ssh->state->hook_in = hook;
259: ssh->state->hook_in_ctx = ctx;
260: }
261:
1.228 djm 262: /* Returns nonzero if rekeying is in progress */
263: int
264: ssh_packet_is_rekeying(struct ssh *ssh)
265: {
1.249 djm 266: return ssh->state->rekeying ||
267: (ssh->kex != NULL && ssh->kex->done == 0);
1.228 djm 268: }
269:
1.16 markus 270: /*
1.253 naddy 271: * Sets the descriptors used for communication.
1.16 markus 272: */
1.201 markus 273: struct ssh *
274: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1 deraadt 275: {
1.201 markus 276: struct session_state *state;
277: const struct sshcipher *none = cipher_by_name("none");
1.197 djm 278: int r;
1.97 deraadt 279:
1.205 djm 280: if (none == NULL) {
281: error("%s: cannot load cipher 'none'", __func__);
282: return NULL;
283: }
1.201 markus 284: if (ssh == NULL)
285: ssh = ssh_alloc_session_state();
1.205 djm 286: if (ssh == NULL) {
287: error("%s: cound not allocate state", __func__);
288: return NULL;
289: }
1.201 markus 290: state = ssh->state;
291: state->connection_in = fd_in;
292: state->connection_out = fd_out;
293: if ((r = cipher_init(&state->send_context, none,
1.197 djm 294: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201 markus 295: (r = cipher_init(&state->receive_context, none,
1.205 djm 296: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
297: error("%s: cipher_init failed: %s", __func__, ssh_err(r));
1.230 djm 298: free(ssh); /* XXX need ssh_free_session_state? */
1.205 djm 299: return NULL;
300: }
1.201 markus 301: state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
1.207 djm 302: /*
303: * Cache the IP address of the remote connection for use in error
304: * messages that might be generated after the connection has closed.
305: */
306: (void)ssh_remote_ipaddr(ssh);
1.201 markus 307: return ssh;
1.1 deraadt 308: }
309:
1.154 dtucker 310: void
1.201 markus 311: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 312: {
1.201 markus 313: struct session_state *state = ssh->state;
314:
1.174 djm 315: if (timeout <= 0 || count <= 0) {
1.201 markus 316: state->packet_timeout_ms = -1;
1.154 dtucker 317: return;
318: }
319: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 320: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 321: else
1.201 markus 322: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 323: }
324:
1.242 markus 325: void
326: ssh_packet_set_mux(struct ssh *ssh)
327: {
328: ssh->state->mux = 1;
329: ssh->state->rekeying = 0;
330: }
331:
332: int
333: ssh_packet_get_mux(struct ssh *ssh)
334: {
335: return ssh->state->mux;
336: }
337:
1.201 markus 338: int
1.245 djm 339: ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
340: {
341: va_list args;
342: int r;
343:
344: free(ssh->log_preamble);
345: if (fmt == NULL)
346: ssh->log_preamble = NULL;
347: else {
348: va_start(args, fmt);
349: r = vasprintf(&ssh->log_preamble, fmt, args);
350: va_end(args);
351: if (r < 0 || ssh->log_preamble == NULL)
352: return SSH_ERR_ALLOC_FAIL;
353: }
354: return 0;
355: }
356:
357: int
1.201 markus 358: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 359: {
1.201 markus 360: struct session_state *state = ssh->state;
361: int r;
362:
363: if (state->packet_discard_mac) {
1.159 markus 364: char buf[1024];
1.234 markus 365: size_t dlen = PACKET_MAX_SIZE;
1.201 markus 366:
1.234 markus 367: if (dlen > state->packet_discard_mac_already)
368: dlen -= state->packet_discard_mac_already;
1.159 markus 369: memset(buf, 'a', sizeof(buf));
1.234 markus 370: while (sshbuf_len(state->incoming_packet) < dlen)
1.201 markus 371: if ((r = sshbuf_put(state->incoming_packet, buf,
372: sizeof(buf))) != 0)
373: return r;
374: (void) mac_compute(state->packet_discard_mac,
375: state->p_read.seqnr,
1.234 markus 376: sshbuf_ptr(state->incoming_packet), dlen,
1.201 markus 377: NULL, 0);
1.159 markus 378: }
1.220 djm 379: logit("Finished discarding for %.200s port %d",
380: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 381: return SSH_ERR_MAC_INVALID;
1.159 markus 382: }
383:
1.201 markus 384: static int
385: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
1.234 markus 386: struct sshmac *mac, size_t mac_already, u_int discard)
1.159 markus 387: {
1.201 markus 388: struct session_state *state = ssh->state;
389: int r;
390:
391: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
392: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
393: return r;
394: return SSH_ERR_MAC_INVALID;
395: }
1.234 markus 396: /*
397: * Record number of bytes over which the mac has already
398: * been computed in order to minimize timing attacks.
399: */
400: if (mac && mac->enabled) {
1.201 markus 401: state->packet_discard_mac = mac;
1.234 markus 402: state->packet_discard_mac_already = mac_already;
403: }
404: if (sshbuf_len(state->input) >= discard)
405: return ssh_packet_stop_discard(ssh);
1.201 markus 406: state->packet_discard = discard - sshbuf_len(state->input);
407: return 0;
1.159 markus 408: }
409:
1.19 markus 410: /* Returns 1 if remote host is connected via socket, 0 if not. */
411:
412: int
1.201 markus 413: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 414: {
1.201 markus 415: struct session_state *state = ssh->state;
1.19 markus 416: struct sockaddr_storage from, to;
417: socklen_t fromlen, tolen;
418:
1.230 djm 419: if (state->connection_in == -1 || state->connection_out == -1)
420: return 0;
421:
1.19 markus 422: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 423: if (state->connection_in == state->connection_out)
1.19 markus 424: return 1;
425: fromlen = sizeof(from);
426: memset(&from, 0, sizeof(from));
1.201 markus 427: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.161 andreas 428: &fromlen) < 0)
1.19 markus 429: return 0;
430: tolen = sizeof(to);
431: memset(&to, 0, sizeof(to));
1.201 markus 432: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.161 andreas 433: &tolen) < 0)
1.19 markus 434: return 0;
435: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
436: return 0;
437: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
438: return 0;
439: return 1;
440: }
441:
1.91 markus 442: void
1.201 markus 443: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 444: {
1.201 markus 445: if (ibytes)
446: *ibytes = ssh->state->p_read.bytes;
447: if (obytes)
448: *obytes = ssh->state->p_send.bytes;
1.91 markus 449: }
1.125 deraadt 450:
1.91 markus 451: int
1.201 markus 452: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 453: {
454: struct sockaddr_storage to;
1.21 deraadt 455: socklen_t tolen = sizeof(to);
1.19 markus 456:
457: memset(&to, 0, sizeof(to));
1.201 markus 458: if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
1.161 andreas 459: &tolen) < 0)
1.19 markus 460: return 0;
1.173 djm 461: return to.ss_family;
1.19 markus 462: }
463:
1.1 deraadt 464: /* Sets the connection into non-blocking mode. */
465:
1.2 provos 466: void
1.201 markus 467: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 468: {
1.14 markus 469: /* Set the socket into non-blocking mode. */
1.201 markus 470: set_nonblock(ssh->state->connection_in);
1.14 markus 471:
1.201 markus 472: if (ssh->state->connection_out != ssh->state->connection_in)
473: set_nonblock(ssh->state->connection_out);
1.1 deraadt 474: }
475:
476: /* Returns the socket used for reading. */
477:
1.2 provos 478: int
1.201 markus 479: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 480: {
1.201 markus 481: return ssh->state->connection_in;
1.1 deraadt 482: }
483:
484: /* Returns the descriptor used for writing. */
485:
1.2 provos 486: int
1.201 markus 487: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 488: {
1.201 markus 489: return ssh->state->connection_out;
490: }
491:
492: /*
493: * Returns the IP-address of the remote host as a string. The returned
494: * string must not be freed.
495: */
496:
497: const char *
498: ssh_remote_ipaddr(struct ssh *ssh)
499: {
1.220 djm 500: const int sock = ssh->state->connection_in;
501:
1.201 markus 502: /* Check whether we have cached the ipaddr. */
1.220 djm 503: if (ssh->remote_ipaddr == NULL) {
504: if (ssh_packet_connection_is_on_socket(ssh)) {
505: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 djm 506: ssh->remote_port = get_peer_port(sock);
507: ssh->local_ipaddr = get_local_ipaddr(sock);
508: ssh->local_port = get_local_port(sock);
1.220 djm 509: } else {
510: ssh->remote_ipaddr = strdup("UNKNOWN");
1.230 djm 511: ssh->remote_port = 65535;
512: ssh->local_ipaddr = strdup("UNKNOWN");
513: ssh->local_port = 65535;
1.220 djm 514: }
515: }
1.201 markus 516: return ssh->remote_ipaddr;
1.1 deraadt 517: }
518:
1.220 djm 519: /* Returns the port number of the remote host. */
520:
521: int
522: ssh_remote_port(struct ssh *ssh)
523: {
524: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
525: return ssh->remote_port;
1.230 djm 526: }
527:
528: /*
529: * Returns the IP-address of the local host as a string. The returned
530: * string must not be freed.
531: */
532:
533: const char *
534: ssh_local_ipaddr(struct ssh *ssh)
535: {
536: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
537: return ssh->local_ipaddr;
538: }
539:
540: /* Returns the port number of the local host. */
541:
542: int
543: ssh_local_port(struct ssh *ssh)
544: {
545: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
546: return ssh->local_port;
1.220 djm 547: }
548:
1.1 deraadt 549: /* Closes the connection and clears and frees internal data structures. */
550:
1.2 provos 551: void
1.201 markus 552: ssh_packet_close(struct ssh *ssh)
1.1 deraadt 553: {
1.201 markus 554: struct session_state *state = ssh->state;
555: u_int mode;
556:
557: if (!state->initialized)
1.14 markus 558: return;
1.201 markus 559: state->initialized = 0;
560: if (state->connection_in == state->connection_out) {
561: shutdown(state->connection_out, SHUT_RDWR);
562: close(state->connection_out);
1.14 markus 563: } else {
1.201 markus 564: close(state->connection_in);
565: close(state->connection_out);
1.14 markus 566: }
1.201 markus 567: sshbuf_free(state->input);
568: sshbuf_free(state->output);
569: sshbuf_free(state->outgoing_packet);
570: sshbuf_free(state->incoming_packet);
571: for (mode = 0; mode < MODE_MAX; mode++)
572: kex_free_newkeys(state->newkeys[mode]);
573: if (state->compression_buffer) {
574: sshbuf_free(state->compression_buffer);
575: if (state->compression_out_started) {
576: z_streamp stream = &state->compression_out_stream;
577: debug("compress outgoing: "
578: "raw data %llu, compressed %llu, factor %.2f",
579: (unsigned long long)stream->total_in,
580: (unsigned long long)stream->total_out,
581: stream->total_in == 0 ? 0.0 :
582: (double) stream->total_out / stream->total_in);
583: if (state->compression_out_failures == 0)
584: deflateEnd(stream);
585: }
586: if (state->compression_in_started) {
587: z_streamp stream = &state->compression_out_stream;
588: debug("compress incoming: "
589: "raw data %llu, compressed %llu, factor %.2f",
590: (unsigned long long)stream->total_out,
591: (unsigned long long)stream->total_in,
592: stream->total_out == 0 ? 0.0 :
593: (double) stream->total_in / stream->total_out);
594: if (state->compression_in_failures == 0)
595: inflateEnd(stream);
596: }
1.14 markus 597: }
1.235 djm 598: cipher_free(state->send_context);
599: cipher_free(state->receive_context);
600: state->send_context = state->receive_context = NULL;
1.219 mmcc 601: free(ssh->remote_ipaddr);
602: ssh->remote_ipaddr = NULL;
1.201 markus 603: free(ssh->state);
604: ssh->state = NULL;
1.1 deraadt 605: }
606:
607: /* Sets remote side protocol flags. */
608:
1.2 provos 609: void
1.201 markus 610: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 611: {
1.201 markus 612: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 613: }
614:
615: /* Returns the remote protocol flags set earlier by the above function. */
616:
1.40 markus 617: u_int
1.201 markus 618: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 619: {
1.201 markus 620: return ssh->state->remote_protocol_flags;
1.1 deraadt 621: }
622:
1.16 markus 623: /*
624: * Starts packet compression from the next packet on in both directions.
625: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
626: */
1.1 deraadt 627:
1.201 markus 628: static int
629: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 630: {
1.201 markus 631: if (!ssh->state->compression_buffer &&
632: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
633: return SSH_ERR_ALLOC_FAIL;
634: return 0;
1.60 markus 635: }
636:
1.201 markus 637: static int
638: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 639: {
1.201 markus 640: if (level < 1 || level > 9)
641: return SSH_ERR_INVALID_ARGUMENT;
642: debug("Enabling compression at level %d.", level);
643: if (ssh->state->compression_out_started == 1)
644: deflateEnd(&ssh->state->compression_out_stream);
645: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
646: case Z_OK:
647: ssh->state->compression_out_started = 1;
648: break;
649: case Z_MEM_ERROR:
650: return SSH_ERR_ALLOC_FAIL;
651: default:
652: return SSH_ERR_INTERNAL_ERROR;
653: }
654: return 0;
1.1 deraadt 655: }
656:
1.201 markus 657: static int
658: start_compression_in(struct ssh *ssh)
659: {
660: if (ssh->state->compression_in_started == 1)
661: inflateEnd(&ssh->state->compression_in_stream);
662: switch (inflateInit(&ssh->state->compression_in_stream)) {
663: case Z_OK:
664: ssh->state->compression_in_started = 1;
665: break;
666: case Z_MEM_ERROR:
667: return SSH_ERR_ALLOC_FAIL;
668: default:
669: return SSH_ERR_INTERNAL_ERROR;
670: }
671: return 0;
672: }
1.95 markus 673:
1.201 markus 674: int
675: ssh_packet_start_compression(struct ssh *ssh, int level)
1.1 deraadt 676: {
1.197 djm 677: int r;
1.97 deraadt 678:
1.249 djm 679: if (ssh->state->packet_compression)
1.201 markus 680: return SSH_ERR_INTERNAL_ERROR;
681: ssh->state->packet_compression = 1;
682: if ((r = ssh_packet_init_compression(ssh)) != 0 ||
683: (r = start_compression_in(ssh)) != 0 ||
684: (r = start_compression_out(ssh, level)) != 0)
685: return r;
686: return 0;
1.95 markus 687: }
688:
1.201 markus 689: /* XXX remove need for separate compression buffer */
690: static int
691: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 692: {
1.201 markus 693: u_char buf[4096];
694: int r, status;
695:
696: if (ssh->state->compression_out_started != 1)
697: return SSH_ERR_INTERNAL_ERROR;
698:
699: /* This case is not handled below. */
700: if (sshbuf_len(in) == 0)
701: return 0;
702:
703: /* Input is the contents of the input buffer. */
704: if ((ssh->state->compression_out_stream.next_in =
705: sshbuf_mutable_ptr(in)) == NULL)
706: return SSH_ERR_INTERNAL_ERROR;
707: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
708:
709: /* Loop compressing until deflate() returns with avail_out != 0. */
710: do {
711: /* Set up fixed-size output buffer. */
712: ssh->state->compression_out_stream.next_out = buf;
713: ssh->state->compression_out_stream.avail_out = sizeof(buf);
714:
715: /* Compress as much data into the buffer as possible. */
716: status = deflate(&ssh->state->compression_out_stream,
717: Z_PARTIAL_FLUSH);
718: switch (status) {
719: case Z_MEM_ERROR:
720: return SSH_ERR_ALLOC_FAIL;
721: case Z_OK:
722: /* Append compressed data to output_buffer. */
723: if ((r = sshbuf_put(out, buf, sizeof(buf) -
724: ssh->state->compression_out_stream.avail_out)) != 0)
725: return r;
726: break;
727: case Z_STREAM_ERROR:
728: default:
729: ssh->state->compression_out_failures++;
730: return SSH_ERR_INVALID_FORMAT;
731: }
732: } while (ssh->state->compression_out_stream.avail_out == 0);
733: return 0;
1.1 deraadt 734: }
735:
1.201 markus 736: static int
737: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 738: {
1.201 markus 739: u_char buf[4096];
740: int r, status;
1.1 deraadt 741:
1.201 markus 742: if (ssh->state->compression_in_started != 1)
743: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 744:
1.201 markus 745: if ((ssh->state->compression_in_stream.next_in =
746: sshbuf_mutable_ptr(in)) == NULL)
747: return SSH_ERR_INTERNAL_ERROR;
748: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 749:
1.201 markus 750: for (;;) {
751: /* Set up fixed-size output buffer. */
752: ssh->state->compression_in_stream.next_out = buf;
753: ssh->state->compression_in_stream.avail_out = sizeof(buf);
754:
755: status = inflate(&ssh->state->compression_in_stream,
756: Z_PARTIAL_FLUSH);
757: switch (status) {
758: case Z_OK:
759: if ((r = sshbuf_put(out, buf, sizeof(buf) -
760: ssh->state->compression_in_stream.avail_out)) != 0)
761: return r;
762: break;
763: case Z_BUF_ERROR:
764: /*
765: * Comments in zlib.h say that we should keep calling
766: * inflate() until we get an error. This appears to
767: * be the error that we get.
768: */
769: return 0;
770: case Z_DATA_ERROR:
771: return SSH_ERR_INVALID_FORMAT;
772: case Z_MEM_ERROR:
773: return SSH_ERR_ALLOC_FAIL;
774: case Z_STREAM_ERROR:
775: default:
776: ssh->state->compression_in_failures++;
777: return SSH_ERR_INTERNAL_ERROR;
778: }
779: }
780: /* NOTREACHED */
1.170 djm 781: }
782:
1.201 markus 783: int
784: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 785: {
1.201 markus 786: struct session_state *state = ssh->state;
787: struct sshenc *enc;
788: struct sshmac *mac;
789: struct sshcomp *comp;
1.235 djm 790: struct sshcipher_ctx **ccp;
1.236 markus 791: struct packet_state *ps;
1.105 markus 792: u_int64_t *max_blocks;
1.236 markus 793: const char *wmsg, *dir;
1.197 djm 794: int r, crypt_type;
1.57 markus 795:
1.100 markus 796: debug2("set_newkeys: mode %d", mode);
1.57 markus 797:
1.88 markus 798: if (mode == MODE_OUT) {
1.236 markus 799: dir = "output";
1.235 djm 800: ccp = &state->send_context;
1.115 avsm 801: crypt_type = CIPHER_ENCRYPT;
1.236 markus 802: ps = &state->p_send;
1.201 markus 803: max_blocks = &state->max_blocks_out;
1.88 markus 804: } else {
1.236 markus 805: dir = "input";
1.235 djm 806: ccp = &state->receive_context;
1.115 avsm 807: crypt_type = CIPHER_DECRYPT;
1.236 markus 808: ps = &state->p_read;
1.201 markus 809: max_blocks = &state->max_blocks_in;
1.88 markus 810: }
1.201 markus 811: if (state->newkeys[mode] != NULL) {
1.236 markus 812: debug("%s: rekeying after %llu %s blocks"
813: " (%llu bytes total)", __func__,
814: (unsigned long long)ps->blocks, dir,
815: (unsigned long long)ps->bytes);
1.235 djm 816: cipher_free(*ccp);
817: *ccp = NULL;
1.201 markus 818: enc = &state->newkeys[mode]->enc;
819: mac = &state->newkeys[mode]->mac;
820: comp = &state->newkeys[mode]->comp;
1.148 pvalchev 821: mac_clear(mac);
1.192 djm 822: explicit_bzero(enc->iv, enc->iv_len);
823: explicit_bzero(enc->key, enc->key_len);
824: explicit_bzero(mac->key, mac->key_len);
1.186 djm 825: free(enc->name);
826: free(enc->iv);
827: free(enc->key);
828: free(mac->name);
829: free(mac->key);
830: free(comp->name);
1.201 markus 831: free(state->newkeys[mode]);
1.57 markus 832: }
1.236 markus 833: /* note that both bytes and the seqnr are not reset */
834: ps->packets = ps->blocks = 0;
1.201 markus 835: /* move newkeys from kex to state */
836: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
837: return SSH_ERR_INTERNAL_ERROR;
838: ssh->kex->newkeys[mode] = NULL;
839: enc = &state->newkeys[mode]->enc;
840: mac = &state->newkeys[mode]->mac;
841: comp = &state->newkeys[mode]->comp;
842: if (cipher_authlen(enc->cipher) == 0) {
843: if ((r = mac_init(mac)) != 0)
844: return r;
845: }
846: mac->enabled = 1;
1.57 markus 847: DBG(debug("cipher_init_context: %d", mode));
1.235 djm 848: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 849: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 850: return r;
851: if (!state->cipher_warning_done &&
1.235 djm 852: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 853: error("Warning: %s", wmsg);
854: state->cipher_warning_done = 1;
855: }
1.91 markus 856: /* Deleting the keys does not gain extra security */
1.192 djm 857: /* explicit_bzero(enc->iv, enc->block_size);
858: explicit_bzero(enc->key, enc->key_len);
859: explicit_bzero(mac->key, mac->key_len); */
1.241 djm 860: if ((comp->type == COMP_ZLIB ||
861: (comp->type == COMP_DELAYED &&
862: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 863: if ((r = ssh_packet_init_compression(ssh)) < 0)
864: return r;
865: if (mode == MODE_OUT) {
866: if ((r = start_compression_out(ssh, 6)) != 0)
867: return r;
868: } else {
869: if ((r = start_compression_in(ssh)) != 0)
870: return r;
871: }
1.57 markus 872: comp->enabled = 1;
873: }
1.109 markus 874: /*
875: * The 2^(blocksize*2) limit is too expensive for 3DES,
1.254 ! djm 876: * so enforce a 1GB limit for small blocksizes.
1.109 markus 877: */
878: if (enc->block_size >= 16)
879: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
880: else
881: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 882: if (state->rekey_limit)
1.237 deraadt 883: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 884: state->rekey_limit / enc->block_size);
1.227 djm 885: debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1.201 markus 886: return 0;
1.57 markus 887: }
888:
1.228 djm 889: #define MAX_PACKETS (1U<<31)
890: static int
891: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
892: {
893: struct session_state *state = ssh->state;
894: u_int32_t out_blocks;
895:
896: /* XXX client can't cope with rekeying pre-auth */
897: if (!state->after_authentication)
898: return 0;
899:
900: /* Haven't keyed yet or KEX in progress. */
901: if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
902: return 0;
903:
904: /* Peer can't rekey */
905: if (ssh->compat & SSH_BUG_NOREKEY)
906: return 0;
907:
908: /*
909: * Permit one packet in or out per rekey - this allows us to
910: * make progress when rekey limits are very small.
911: */
912: if (state->p_send.packets == 0 && state->p_read.packets == 0)
913: return 0;
914:
915: /* Time-based rekeying */
916: if (state->rekey_interval != 0 &&
1.244 dtucker 917: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 918: return 1;
919:
920: /* Always rekey when MAX_PACKETS sent in either direction */
921: if (state->p_send.packets > MAX_PACKETS ||
922: state->p_read.packets > MAX_PACKETS)
923: return 1;
924:
925: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 926: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 927: state->newkeys[MODE_OUT]->enc.block_size);
928: return (state->max_blocks_out &&
929: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
930: (state->max_blocks_in &&
931: (state->p_read.blocks > state->max_blocks_in));
932: }
933:
1.16 markus 934: /*
1.118 markus 935: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 936: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 937: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
938: */
1.201 markus 939: static int
940: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 941: {
1.201 markus 942: struct session_state *state = ssh->state;
943: struct sshcomp *comp = NULL;
944: int r, mode;
1.118 markus 945:
946: /*
947: * Remember that we are past the authentication step, so rekeying
948: * with COMP_DELAYED will turn on compression immediately.
949: */
1.201 markus 950: state->after_authentication = 1;
1.118 markus 951: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 952: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 953: if (state->newkeys[mode] == NULL)
1.145 markus 954: continue;
1.201 markus 955: comp = &state->newkeys[mode]->comp;
1.118 markus 956: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 957: if ((r = ssh_packet_init_compression(ssh)) != 0)
958: return r;
959: if (mode == MODE_OUT) {
960: if ((r = start_compression_out(ssh, 6)) != 0)
961: return r;
962: } else {
963: if ((r = start_compression_in(ssh)) != 0)
964: return r;
965: }
1.118 markus 966: comp->enabled = 1;
967: }
968: }
1.201 markus 969: return 0;
1.118 markus 970: }
971:
1.226 djm 972: /* Used to mute debug logging for noisy packet types */
1.242 markus 973: int
1.226 djm 974: ssh_packet_log_type(u_char type)
975: {
976: switch (type) {
977: case SSH2_MSG_CHANNEL_DATA:
978: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
979: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
980: return 0;
981: default:
982: return 1;
983: }
984: }
985:
1.118 markus 986: /*
1.25 markus 987: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
988: */
1.201 markus 989: int
990: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 991: {
1.201 markus 992: struct session_state *state = ssh->state;
1.200 markus 993: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 994: u_char tmp, padlen, pad = 0;
1.201 markus 995: u_int authlen = 0, aadlen = 0;
996: u_int len;
997: struct sshenc *enc = NULL;
998: struct sshmac *mac = NULL;
999: struct sshcomp *comp = NULL;
1000: int r, block_size;
1001:
1002: if (state->newkeys[MODE_OUT] != NULL) {
1003: enc = &state->newkeys[MODE_OUT]->enc;
1004: mac = &state->newkeys[MODE_OUT]->mac;
1005: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1006: /* disable mac for authenticated encryption */
1007: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1008: mac = NULL;
1.25 markus 1009: }
1.88 markus 1010: block_size = enc ? enc->block_size : 8;
1.180 markus 1011: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1012:
1.201 markus 1013: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1014: if (ssh_packet_log_type(type))
1015: debug3("send packet: type %u", type);
1.25 markus 1016: #ifdef PACKET_DEBUG
1017: fprintf(stderr, "plain: ");
1.201 markus 1018: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1019: #endif
1020:
1021: if (comp && comp->enabled) {
1.201 markus 1022: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1023: /* skip header, compress only payload */
1.201 markus 1024: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1025: goto out;
1026: sshbuf_reset(state->compression_buffer);
1027: if ((r = compress_buffer(ssh, state->outgoing_packet,
1028: state->compression_buffer)) != 0)
1029: goto out;
1030: sshbuf_reset(state->outgoing_packet);
1031: if ((r = sshbuf_put(state->outgoing_packet,
1032: "\0\0\0\0\0", 5)) != 0 ||
1033: (r = sshbuf_putb(state->outgoing_packet,
1034: state->compression_buffer)) != 0)
1035: goto out;
1036: DBG(debug("compression: raw %d compressed %zd", len,
1037: sshbuf_len(state->outgoing_packet)));
1.25 markus 1038: }
1039:
1040: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1041: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1042:
1043: /*
1044: * calc size of padding, alloc space, get random data,
1045: * minimum padding is 4 bytes
1046: */
1.178 markus 1047: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1048: padlen = block_size - (len % block_size);
1049: if (padlen < 4)
1050: padlen += block_size;
1.201 markus 1051: if (state->extra_pad) {
1.233 djm 1052: tmp = state->extra_pad;
1.201 markus 1053: state->extra_pad =
1.237 deraadt 1054: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1055: /* check if roundup overflowed */
1056: if (state->extra_pad < tmp)
1057: return SSH_ERR_INVALID_ARGUMENT;
1058: tmp = (len + padlen) % state->extra_pad;
1059: /* Check whether pad calculation below will underflow */
1060: if (tmp > state->extra_pad)
1061: return SSH_ERR_INVALID_ARGUMENT;
1062: pad = state->extra_pad - tmp;
1.193 djm 1063: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1064: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1065: tmp = padlen;
1.71 markus 1066: padlen += pad;
1.233 djm 1067: /* Check whether padlen calculation overflowed */
1068: if (padlen < tmp)
1069: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1070: state->extra_pad = 0;
1.71 markus 1071: }
1.201 markus 1072: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1073: goto out;
1.235 djm 1074: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1075: /* random padding */
1.201 markus 1076: arc4random_buf(cp, padlen);
1.32 markus 1077: } else {
1078: /* clear padding */
1.192 djm 1079: explicit_bzero(cp, padlen);
1.25 markus 1080: }
1.178 markus 1081: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1082: len = sshbuf_len(state->outgoing_packet);
1083: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1084: if (cp == NULL) {
1085: r = SSH_ERR_INTERNAL_ERROR;
1086: goto out;
1087: }
1.25 markus 1088: /* packet_length includes payload, padding and padding length field */
1.201 markus 1089: POKE_U32(cp, len - 4);
1.89 markus 1090: cp[4] = padlen;
1.178 markus 1091: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1092: len, padlen, aadlen));
1.25 markus 1093:
1094: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1095: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1096: if ((r = mac_compute(mac, state->p_send.seqnr,
1097: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1098: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1099: goto out;
1100: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1101: }
1102: /* encrypt packet and append to output buffer. */
1.201 markus 1103: if ((r = sshbuf_reserve(state->output,
1104: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1105: goto out;
1.235 djm 1106: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1107: sshbuf_ptr(state->outgoing_packet),
1108: len - aadlen, aadlen, authlen)) != 0)
1109: goto out;
1.25 markus 1110: /* append unencrypted MAC */
1.178 markus 1111: if (mac && mac->enabled) {
1112: if (mac->etm) {
1113: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1114: if ((r = mac_compute(mac, state->p_send.seqnr,
1115: cp, len, macbuf, sizeof(macbuf))) != 0)
1116: goto out;
1.178 markus 1117: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1118: state->p_send.seqnr));
1.178 markus 1119: }
1.201 markus 1120: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1121: goto out;
1.178 markus 1122: }
1.25 markus 1123: #ifdef PACKET_DEBUG
1124: fprintf(stderr, "encrypted: ");
1.201 markus 1125: sshbuf_dump(state->output, stderr);
1.25 markus 1126: #endif
1.29 markus 1127: /* increment sequence number for outgoing packets */
1.201 markus 1128: if (++state->p_send.seqnr == 0)
1.106 itojun 1129: logit("outgoing seqnr wraps around");
1.201 markus 1130: if (++state->p_send.packets == 0)
1131: if (!(ssh->compat & SSH_BUG_NOREKEY))
1132: return SSH_ERR_NEED_REKEY;
1133: state->p_send.blocks += len / block_size;
1134: state->p_send.bytes += len;
1135: sshbuf_reset(state->outgoing_packet);
1.25 markus 1136:
1.57 markus 1137: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1138: r = ssh_set_newkeys(ssh, MODE_OUT);
1139: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1140: r = ssh_packet_enable_delayed_compress(ssh);
1141: else
1142: r = 0;
1143: out:
1144: return r;
1.25 markus 1145: }
1146:
1.228 djm 1147: /* returns non-zero if the specified packet type is usec by KEX */
1148: static int
1149: ssh_packet_type_is_kex(u_char type)
1150: {
1151: return
1152: type >= SSH2_MSG_TRANSPORT_MIN &&
1153: type <= SSH2_MSG_TRANSPORT_MAX &&
1154: type != SSH2_MSG_SERVICE_REQUEST &&
1155: type != SSH2_MSG_SERVICE_ACCEPT &&
1156: type != SSH2_MSG_EXT_INFO;
1157: }
1158:
1.201 markus 1159: int
1160: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1161: {
1.201 markus 1162: struct session_state *state = ssh->state;
1.105 markus 1163: struct packet *p;
1.201 markus 1164: u_char type;
1.228 djm 1165: int r, need_rekey;
1.105 markus 1166:
1.228 djm 1167: if (sshbuf_len(state->outgoing_packet) < 6)
1168: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1169: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1170: need_rekey = !ssh_packet_type_is_kex(type) &&
1171: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1172:
1.228 djm 1173: /*
1174: * During rekeying we can only send key exchange messages.
1175: * Queue everything else.
1176: */
1177: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1178: if (need_rekey)
1179: debug3("%s: rekex triggered", __func__);
1180: debug("enqueue packet: %u", type);
1181: p = calloc(1, sizeof(*p));
1182: if (p == NULL)
1183: return SSH_ERR_ALLOC_FAIL;
1184: p->type = type;
1185: p->payload = state->outgoing_packet;
1186: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1187: state->outgoing_packet = sshbuf_new();
1188: if (state->outgoing_packet == NULL)
1189: return SSH_ERR_ALLOC_FAIL;
1190: if (need_rekey) {
1191: /*
1192: * This packet triggered a rekey, so send the
1193: * KEXINIT now.
1194: * NB. reenters this function via kex_start_rekex().
1195: */
1196: return kex_start_rekex(ssh);
1.105 markus 1197: }
1.228 djm 1198: return 0;
1.105 markus 1199: }
1200:
1201: /* rekeying starts with sending KEXINIT */
1202: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1203: state->rekeying = 1;
1.105 markus 1204:
1.201 markus 1205: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1206: return r;
1.105 markus 1207:
1208: /* after a NEWKEYS message we can send the complete queue */
1209: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1210: state->rekeying = 0;
1211: state->rekey_time = monotime();
1212: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1213: type = p->type;
1.228 djm 1214: /*
1215: * If this packet triggers a rekex, then skip the
1216: * remaining packets in the queue for now.
1217: * NB. re-enters this function via kex_start_rekex.
1218: */
1219: if (ssh_packet_need_rekeying(ssh,
1220: sshbuf_len(p->payload))) {
1221: debug3("%s: queued packet triggered rekex",
1222: __func__);
1223: return kex_start_rekex(ssh);
1224: }
1.105 markus 1225: debug("dequeue packet: %u", type);
1.201 markus 1226: sshbuf_free(state->outgoing_packet);
1227: state->outgoing_packet = p->payload;
1228: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1229: memset(p, 0, sizeof(*p));
1.186 djm 1230: free(p);
1.201 markus 1231: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1232: return r;
1.105 markus 1233: }
1234: }
1.201 markus 1235: return 0;
1.25 markus 1236: }
1237:
1238: /*
1.16 markus 1239: * Waits until a packet has been received, and returns its type. Note that
1240: * no other data is processed until this returns, so this function should not
1241: * be used during the interactive session.
1242: */
1.1 deraadt 1243:
1.2 provos 1244: int
1.201 markus 1245: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1246: {
1.201 markus 1247: struct session_state *state = ssh->state;
1.222 markus 1248: int len, r, ms_remain;
1.56 millert 1249: fd_set *setp;
1.14 markus 1250: char buf[8192];
1.155 deraadt 1251: struct timeval timeout, start, *timeoutp = NULL;
1252:
1.25 markus 1253: DBG(debug("packet_read()"));
1.14 markus 1254:
1.214 deraadt 1255: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1256: NFDBITS), sizeof(fd_mask));
1.201 markus 1257: if (setp == NULL)
1258: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1259:
1.205 djm 1260: /*
1261: * Since we are blocking, ensure that all written packets have
1262: * been sent.
1263: */
1.210 markus 1264: if ((r = ssh_packet_write_wait(ssh)) != 0)
1265: goto out;
1.14 markus 1266:
1267: /* Stay in the loop until we have received a complete packet. */
1268: for (;;) {
1269: /* Try to read a packet from the buffer. */
1.201 markus 1270: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1271: if (r != 0)
1272: break;
1.14 markus 1273: /* If we got a packet, return it. */
1.201 markus 1274: if (*typep != SSH_MSG_NONE)
1275: break;
1.16 markus 1276: /*
1277: * Otherwise, wait for some data to arrive, add it to the
1278: * buffer, and try again.
1279: */
1.201 markus 1280: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1281: NFDBITS) * sizeof(fd_mask));
1.201 markus 1282: FD_SET(state->connection_in, setp);
1.16 markus 1283:
1.201 markus 1284: if (state->packet_timeout_ms > 0) {
1285: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1286: timeoutp = &timeout;
1287: }
1.14 markus 1288: /* Wait for some data to arrive. */
1.154 dtucker 1289: for (;;) {
1.201 markus 1290: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1291: ms_to_timeval(&timeout, ms_remain);
1292: gettimeofday(&start, NULL);
1293: }
1.201 markus 1294: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1295: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1296: break;
1.161 andreas 1297: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1298: break;
1.201 markus 1299: if (state->packet_timeout_ms == -1)
1.154 dtucker 1300: continue;
1301: ms_subtract_diff(&start, &ms_remain);
1302: if (ms_remain <= 0) {
1.201 markus 1303: r = 0;
1.154 dtucker 1304: break;
1305: }
1306: }
1.246 djm 1307: if (r == 0) {
1308: r = SSH_ERR_CONN_TIMEOUT;
1309: goto out;
1310: }
1.14 markus 1311: /* Read data from the socket. */
1.222 markus 1312: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1313: if (len == 0) {
1314: r = SSH_ERR_CONN_CLOSED;
1315: goto out;
1316: }
1317: if (len < 0) {
1318: r = SSH_ERR_SYSTEM_ERROR;
1319: goto out;
1320: }
1.204 djm 1321:
1.14 markus 1322: /* Append it to the buffer. */
1.204 djm 1323: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1324: goto out;
1.14 markus 1325: }
1.210 markus 1326: out:
1.201 markus 1327: free(setp);
1328: return r;
1.1 deraadt 1329: }
1330:
1.77 djm 1331: int
1.201 markus 1332: ssh_packet_read(struct ssh *ssh)
1.77 djm 1333: {
1.201 markus 1334: u_char type;
1335: int r;
1336:
1337: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1338: fatal("%s: %s", __func__, ssh_err(r));
1339: return type;
1.77 djm 1340: }
1341:
1.16 markus 1342: /*
1343: * Waits until a packet has been received, verifies that its type matches
1344: * that given, and gives a fatal error and exits if there is a mismatch.
1345: */
1.1 deraadt 1346:
1.205 djm 1347: int
1348: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1349: {
1.205 djm 1350: int r;
1351: u_char type;
1.1 deraadt 1352:
1.205 djm 1353: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1354: return r;
1355: if (type != expected_type) {
1356: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1357: "Protocol error: expected packet type %d, got %d",
1.205 djm 1358: expected_type, type)) != 0)
1359: return r;
1360: return SSH_ERR_PROTOCOL_ERROR;
1361: }
1362: return 0;
1.1 deraadt 1363: }
1.14 markus 1364:
1.242 markus 1365: static int
1366: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1367: {
1368: struct session_state *state = ssh->state;
1369: const u_char *cp;
1370: size_t need;
1371: int r;
1372:
1373: if (ssh->kex)
1374: return SSH_ERR_INTERNAL_ERROR;
1375: *typep = SSH_MSG_NONE;
1376: cp = sshbuf_ptr(state->input);
1377: if (state->packlen == 0) {
1378: if (sshbuf_len(state->input) < 4 + 1)
1379: return 0; /* packet is incomplete */
1380: state->packlen = PEEK_U32(cp);
1381: if (state->packlen < 4 + 1 ||
1382: state->packlen > PACKET_MAX_SIZE)
1383: return SSH_ERR_MESSAGE_INCOMPLETE;
1384: }
1385: need = state->packlen + 4;
1386: if (sshbuf_len(state->input) < need)
1387: return 0; /* packet is incomplete */
1388: sshbuf_reset(state->incoming_packet);
1389: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1390: state->packlen)) != 0 ||
1391: (r = sshbuf_consume(state->input, need)) != 0 ||
1392: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1393: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1394: return r;
1395: if (ssh_packet_log_type(*typep))
1396: debug3("%s: type %u", __func__, *typep);
1397: /* sshbuf_dump(state->incoming_packet, stderr); */
1398: /* reset for next packet */
1399: state->packlen = 0;
1400: return r;
1401: }
1402:
1.201 markus 1403: int
1404: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1405: {
1.201 markus 1406: struct session_state *state = ssh->state;
1.40 markus 1407: u_int padlen, need;
1.231 djm 1408: u_char *cp;
1.201 markus 1409: u_int maclen, aadlen = 0, authlen = 0, block_size;
1410: struct sshenc *enc = NULL;
1411: struct sshmac *mac = NULL;
1412: struct sshcomp *comp = NULL;
1.200 markus 1413: int r;
1.201 markus 1414:
1.242 markus 1415: if (state->mux)
1416: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1417:
1.201 markus 1418: *typep = SSH_MSG_NONE;
1419:
1420: if (state->packet_discard)
1421: return 0;
1422:
1423: if (state->newkeys[MODE_IN] != NULL) {
1424: enc = &state->newkeys[MODE_IN]->enc;
1425: mac = &state->newkeys[MODE_IN]->mac;
1426: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1427: /* disable mac for authenticated encryption */
1428: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1429: mac = NULL;
1.25 markus 1430: }
1431: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1432: block_size = enc ? enc->block_size : 8;
1.180 markus 1433: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1434:
1.201 markus 1435: if (aadlen && state->packlen == 0) {
1.235 djm 1436: if (cipher_get_length(state->receive_context,
1.201 markus 1437: &state->packlen, state->p_read.seqnr,
1438: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1439: return 0;
1440: if (state->packlen < 1 + 4 ||
1441: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1442: #ifdef PACKET_DEBUG
1.201 markus 1443: sshbuf_dump(state->input, stderr);
1.178 markus 1444: #endif
1.201 markus 1445: logit("Bad packet length %u.", state->packlen);
1446: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1447: return r;
1.217 djm 1448: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1449: }
1.201 markus 1450: sshbuf_reset(state->incoming_packet);
1451: } else if (state->packlen == 0) {
1.25 markus 1452: /*
1453: * check if input size is less than the cipher block size,
1454: * decrypt first block and extract length of incoming packet
1455: */
1.201 markus 1456: if (sshbuf_len(state->input) < block_size)
1457: return 0;
1458: sshbuf_reset(state->incoming_packet);
1459: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1460: &cp)) != 0)
1461: goto out;
1.235 djm 1462: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1463: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1464: block_size, 0, 0)) != 0)
1465: goto out;
1466: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1467: if (state->packlen < 1 + 4 ||
1468: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1469: #ifdef PACKET_DEBUG
1.201 markus 1470: fprintf(stderr, "input: \n");
1471: sshbuf_dump(state->input, stderr);
1472: fprintf(stderr, "incoming_packet: \n");
1473: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1474: #endif
1.201 markus 1475: logit("Bad packet length %u.", state->packlen);
1.234 markus 1476: return ssh_packet_start_discard(ssh, enc, mac, 0,
1477: PACKET_MAX_SIZE);
1.25 markus 1478: }
1.201 markus 1479: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1480: goto out;
1.25 markus 1481: }
1.201 markus 1482: DBG(debug("input: packet len %u", state->packlen+4));
1483:
1.178 markus 1484: if (aadlen) {
1485: /* only the payload is encrypted */
1.201 markus 1486: need = state->packlen;
1.178 markus 1487: } else {
1488: /*
1489: * the payload size and the payload are encrypted, but we
1490: * have a partial packet of block_size bytes
1491: */
1.201 markus 1492: need = 4 + state->packlen - block_size;
1.178 markus 1493: }
1.180 markus 1494: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1495: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1496: if (need % block_size != 0) {
1497: logit("padding error: need %d block %d mod %d",
1.25 markus 1498: need, block_size, need % block_size);
1.234 markus 1499: return ssh_packet_start_discard(ssh, enc, mac, 0,
1500: PACKET_MAX_SIZE - block_size);
1.158 markus 1501: }
1.25 markus 1502: /*
1503: * check if the entire packet has been received and
1.178 markus 1504: * decrypt into incoming_packet:
1505: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1506: * 'need' bytes are encrypted, followed by either
1507: * 'authlen' bytes of authentication tag or
1.178 markus 1508: * 'maclen' bytes of message authentication code.
1.25 markus 1509: */
1.201 markus 1510: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1511: return 0; /* packet is incomplete */
1.25 markus 1512: #ifdef PACKET_DEBUG
1513: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1514: sshbuf_dump(state->input, stderr);
1.25 markus 1515: #endif
1.231 djm 1516: /* EtM: check mac over encrypted input */
1.201 markus 1517: if (mac && mac->enabled && mac->etm) {
1.231 djm 1518: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1519: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1520: sshbuf_ptr(state->input) + aadlen + need + authlen,
1521: maclen)) != 0) {
1522: if (r == SSH_ERR_MAC_INVALID)
1523: logit("Corrupted MAC on input.");
1.201 markus 1524: goto out;
1.231 djm 1525: }
1.201 markus 1526: }
1527: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1528: &cp)) != 0)
1529: goto out;
1.235 djm 1530: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1531: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1532: goto out;
1533: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1534: goto out;
1.29 markus 1535: if (mac && mac->enabled) {
1.231 djm 1536: /* Not EtM: check MAC over cleartext */
1537: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1538: sshbuf_ptr(state->incoming_packet),
1539: sshbuf_len(state->incoming_packet),
1540: sshbuf_ptr(state->input), maclen)) != 0) {
1541: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1542: goto out;
1.159 markus 1543: logit("Corrupted MAC on input.");
1.247 markus 1544: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1545: return SSH_ERR_INTERNAL_ERROR;
1546: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1547: sshbuf_len(state->incoming_packet),
1.247 markus 1548: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1549: }
1.231 djm 1550: /* Remove MAC from input buffer */
1.201 markus 1551: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1552: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1553: goto out;
1.25 markus 1554: }
1.77 djm 1555: if (seqnr_p != NULL)
1.201 markus 1556: *seqnr_p = state->p_read.seqnr;
1557: if (++state->p_read.seqnr == 0)
1.106 itojun 1558: logit("incoming seqnr wraps around");
1.201 markus 1559: if (++state->p_read.packets == 0)
1560: if (!(ssh->compat & SSH_BUG_NOREKEY))
1561: return SSH_ERR_NEED_REKEY;
1562: state->p_read.blocks += (state->packlen + 4) / block_size;
1563: state->p_read.bytes += state->packlen + 4;
1.25 markus 1564:
1565: /* get padlen */
1.201 markus 1566: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1567: DBG(debug("input: padlen %d", padlen));
1.205 djm 1568: if (padlen < 4) {
1569: if ((r = sshpkt_disconnect(ssh,
1570: "Corrupted padlen %d on input.", padlen)) != 0 ||
1571: (r = ssh_packet_write_wait(ssh)) != 0)
1572: return r;
1573: return SSH_ERR_CONN_CORRUPT;
1574: }
1.25 markus 1575:
1576: /* skip packet size + padlen, discard padding */
1.201 markus 1577: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1578: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1579: goto out;
1.25 markus 1580:
1.201 markus 1581: DBG(debug("input: len before de-compress %zd",
1582: sshbuf_len(state->incoming_packet)));
1.25 markus 1583: if (comp && comp->enabled) {
1.201 markus 1584: sshbuf_reset(state->compression_buffer);
1585: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1586: state->compression_buffer)) != 0)
1587: goto out;
1588: sshbuf_reset(state->incoming_packet);
1589: if ((r = sshbuf_putb(state->incoming_packet,
1590: state->compression_buffer)) != 0)
1591: goto out;
1592: DBG(debug("input: len after de-compress %zd",
1593: sshbuf_len(state->incoming_packet)));
1.25 markus 1594: }
1595: /*
1596: * get packet type, implies consume.
1597: * return length of payload (without type field)
1598: */
1.201 markus 1599: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1600: goto out;
1.226 djm 1601: if (ssh_packet_log_type(*typep))
1602: debug3("receive packet: type %u", *typep);
1.205 djm 1603: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1604: if ((r = sshpkt_disconnect(ssh,
1605: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1606: (r = ssh_packet_write_wait(ssh)) != 0)
1607: return r;
1608: return SSH_ERR_PROTOCOL_ERROR;
1609: }
1.243 djm 1610: if (state->hook_in != NULL &&
1611: (r = state->hook_in(ssh, state->incoming_packet, typep,
1612: state->hook_in_ctx)) != 0)
1613: return r;
1.238 markus 1614: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1615: r = ssh_packet_enable_delayed_compress(ssh);
1616: else
1617: r = 0;
1.25 markus 1618: #ifdef PACKET_DEBUG
1.201 markus 1619: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1620: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1621: #endif
1.62 markus 1622: /* reset for next packet */
1.201 markus 1623: state->packlen = 0;
1.228 djm 1624:
1625: /* do we need to rekey? */
1626: if (ssh_packet_need_rekeying(ssh, 0)) {
1627: debug3("%s: rekex triggered", __func__);
1628: if ((r = kex_start_rekex(ssh)) != 0)
1629: return r;
1630: }
1.201 markus 1631: out:
1632: return r;
1.25 markus 1633: }
1634:
1635: int
1.201 markus 1636: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1637: {
1.201 markus 1638: struct session_state *state = ssh->state;
1.96 deraadt 1639: u_int reason, seqnr;
1.201 markus 1640: int r;
1641: u_char *msg;
1.62 markus 1642:
1.25 markus 1643: for (;;) {
1.201 markus 1644: msg = NULL;
1.249 djm 1645: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1646: if (r != 0)
1647: return r;
1648: if (*typep) {
1649: state->keep_alive_timeouts = 0;
1650: DBG(debug("received packet type %d", *typep));
1651: }
1652: switch (*typep) {
1653: case SSH2_MSG_IGNORE:
1654: debug3("Received SSH2_MSG_IGNORE");
1655: break;
1656: case SSH2_MSG_DEBUG:
1657: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1658: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1659: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1660: free(msg);
1.201 markus 1661: return r;
1.48 stevesk 1662: }
1.249 djm 1663: debug("Remote: %.900s", msg);
1664: free(msg);
1665: break;
1666: case SSH2_MSG_DISCONNECT:
1667: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1668: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1669: return r;
1670: /* Ignore normal client exit notifications */
1671: do_log2(ssh->state->server_side &&
1672: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1673: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1674: "Received disconnect from %s port %d:"
1675: "%u: %.400s", ssh_remote_ipaddr(ssh),
1676: ssh_remote_port(ssh), reason, msg);
1677: free(msg);
1678: return SSH_ERR_DISCONNECTED;
1679: case SSH2_MSG_UNIMPLEMENTED:
1680: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1681: return r;
1682: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1683: seqnr);
1684: break;
1685: default:
1686: return 0;
1.25 markus 1687: }
1688: }
1689: }
1690:
1.16 markus 1691: /*
1692: * Buffers the given amount of input characters. This is intended to be used
1693: * together with packet_read_poll.
1694: */
1.1 deraadt 1695:
1.204 djm 1696: int
1.201 markus 1697: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1698: {
1.201 markus 1699: struct session_state *state = ssh->state;
1700: int r;
1701:
1702: if (state->packet_discard) {
1703: state->keep_alive_timeouts = 0; /* ?? */
1704: if (len >= state->packet_discard) {
1705: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1706: return r;
1.201 markus 1707: }
1708: state->packet_discard -= len;
1.204 djm 1709: return 0;
1.159 markus 1710: }
1.201 markus 1711: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1712: return r;
1713:
1714: return 0;
1.28 markus 1715: }
1716:
1717: int
1.201 markus 1718: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1719: {
1.201 markus 1720: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1721: }
1722:
1.16 markus 1723: /*
1724: * Sends a diagnostic message from the server to the client. This message
1725: * can be sent at any time (but not while constructing another message). The
1726: * message is printed immediately, but only if the client is being executed
1727: * in verbose mode. These messages are primarily intended to ease debugging
1728: * authentication problems. The length of the formatted message must not
1.205 djm 1729: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1730: */
1.2 provos 1731: void
1.201 markus 1732: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1733: {
1.14 markus 1734: char buf[1024];
1735: va_list args;
1.201 markus 1736: int r;
1.39 markus 1737:
1.249 djm 1738: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1739: return;
1.14 markus 1740:
1741: va_start(args, fmt);
1742: vsnprintf(buf, sizeof(buf), fmt, args);
1743: va_end(args);
1744:
1.249 djm 1745: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1746: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1747: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1748: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1749: (r = sshpkt_send(ssh)) != 0 ||
1750: (r = ssh_packet_write_wait(ssh)) != 0)
1.205 djm 1751: fatal("%s: %s", __func__, ssh_err(r));
1752: }
1753:
1.245 djm 1754: static void
1755: fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1756: {
1757: snprintf(s, l, "%.200s%s%s port %d",
1758: ssh->log_preamble ? ssh->log_preamble : "",
1759: ssh->log_preamble ? " " : "",
1760: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1761: }
1762:
1.205 djm 1763: /*
1764: * Pretty-print connection-terminating errors and exit.
1765: */
1766: void
1767: sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
1768: {
1.245 djm 1769: char remote_id[512];
1770:
1771: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1772:
1.205 djm 1773: switch (r) {
1774: case SSH_ERR_CONN_CLOSED:
1.245 djm 1775: logdie("Connection closed by %s", remote_id);
1.205 djm 1776: case SSH_ERR_CONN_TIMEOUT:
1.245 djm 1777: logdie("Connection %s %s timed out",
1778: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1779: case SSH_ERR_DISCONNECTED:
1.245 djm 1780: logdie("Disconnected from %s", remote_id);
1.212 djm 1781: case SSH_ERR_SYSTEM_ERROR:
1.232 dtucker 1782: if (errno == ECONNRESET)
1.245 djm 1783: logdie("Connection reset by %s", remote_id);
1.213 djm 1784: /* FALLTHROUGH */
1785: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1786: case SSH_ERR_NO_MAC_ALG_MATCH:
1787: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1788: case SSH_ERR_NO_KEX_ALG_MATCH:
1789: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1790: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.245 djm 1791: logdie("Unable to negotiate with %s: %s. "
1792: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1793: ssh->kex->failed_choice);
1.212 djm 1794: }
1795: /* FALLTHROUGH */
1.205 djm 1796: default:
1.245 djm 1797: logdie("%s%sConnection %s %s: %s",
1.205 djm 1798: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 1799: ssh->state->server_side ? "from" : "to",
1.245 djm 1800: remote_id, ssh_err(r));
1.205 djm 1801: }
1.1 deraadt 1802: }
1803:
1.16 markus 1804: /*
1805: * Logs the error plus constructs and sends a disconnect packet, closes the
1806: * connection, and exits. This function never returns. The error message
1807: * should not contain a newline. The length of the formatted message must
1808: * not exceed 1024 bytes.
1809: */
1.2 provos 1810: void
1.201 markus 1811: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1812: {
1.245 djm 1813: char buf[1024], remote_id[512];
1.14 markus 1814: va_list args;
1815: static int disconnecting = 0;
1.201 markus 1816: int r;
1.97 deraadt 1817:
1.14 markus 1818: if (disconnecting) /* Guard against recursive invocations. */
1819: fatal("packet_disconnect called recursively.");
1820: disconnecting = 1;
1821:
1.16 markus 1822: /*
1823: * Format the message. Note that the caller must make sure the
1824: * message is of limited size.
1825: */
1.245 djm 1826: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1827: va_start(args, fmt);
1828: vsnprintf(buf, sizeof(buf), fmt, args);
1829: va_end(args);
1830:
1.99 markus 1831: /* Display the error locally */
1.245 djm 1832: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1833:
1.205 djm 1834: /*
1835: * Send the disconnect message to the other side, and wait
1836: * for it to get sent.
1837: */
1838: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1839: sshpkt_fatal(ssh, __func__, r);
1840:
1841: if ((r = ssh_packet_write_wait(ssh)) != 0)
1842: sshpkt_fatal(ssh, __func__, r);
1.14 markus 1843:
1844: /* Close the connection. */
1.201 markus 1845: ssh_packet_close(ssh);
1.112 markus 1846: cleanup_exit(255);
1.1 deraadt 1847: }
1848:
1.205 djm 1849: /*
1850: * Checks if there is any buffered output, and tries to write some of
1851: * the output.
1852: */
1853: int
1.201 markus 1854: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1855: {
1.201 markus 1856: struct session_state *state = ssh->state;
1857: int len = sshbuf_len(state->output);
1.222 markus 1858: int r;
1.97 deraadt 1859:
1.14 markus 1860: if (len > 0) {
1.222 markus 1861: len = write(state->connection_out,
1862: sshbuf_ptr(state->output), len);
1.156 djm 1863: if (len == -1) {
1864: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1865: return 0;
1866: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1867: }
1.222 markus 1868: if (len == 0)
1.205 djm 1869: return SSH_ERR_CONN_CLOSED;
1.201 markus 1870: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1871: return r;
1.14 markus 1872: }
1.205 djm 1873: return 0;
1.1 deraadt 1874: }
1875:
1.16 markus 1876: /*
1877: * Calls packet_write_poll repeatedly until all pending output data has been
1878: * written.
1879: */
1.205 djm 1880: int
1.201 markus 1881: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1882: {
1.56 millert 1883: fd_set *setp;
1.205 djm 1884: int ret, r, ms_remain = 0;
1.154 dtucker 1885: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1886: struct session_state *state = ssh->state;
1.56 millert 1887:
1.214 deraadt 1888: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1889: NFDBITS), sizeof(fd_mask));
1.201 markus 1890: if (setp == NULL)
1.205 djm 1891: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1892: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1893: free(setp);
1.215 djm 1894: return r;
1.216 gsoares 1895: }
1.201 markus 1896: while (ssh_packet_have_data_to_write(ssh)) {
1897: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1898: NFDBITS) * sizeof(fd_mask));
1.201 markus 1899: FD_SET(state->connection_out, setp);
1.154 dtucker 1900:
1.201 markus 1901: if (state->packet_timeout_ms > 0) {
1902: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1903: timeoutp = &timeout;
1904: }
1905: for (;;) {
1.201 markus 1906: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1907: ms_to_timeval(&timeout, ms_remain);
1908: gettimeofday(&start, NULL);
1909: }
1.201 markus 1910: if ((ret = select(state->connection_out + 1,
1.161 andreas 1911: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1912: break;
1.161 andreas 1913: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1914: break;
1.201 markus 1915: if (state->packet_timeout_ms == -1)
1.154 dtucker 1916: continue;
1917: ms_subtract_diff(&start, &ms_remain);
1918: if (ms_remain <= 0) {
1919: ret = 0;
1920: break;
1921: }
1922: }
1923: if (ret == 0) {
1.205 djm 1924: free(setp);
1925: return SSH_ERR_CONN_TIMEOUT;
1926: }
1927: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1928: free(setp);
1929: return r;
1.154 dtucker 1930: }
1.14 markus 1931: }
1.186 djm 1932: free(setp);
1.205 djm 1933: return 0;
1.1 deraadt 1934: }
1935:
1936: /* Returns true if there is buffered data to write to the connection. */
1937:
1.2 provos 1938: int
1.201 markus 1939: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 1940: {
1.201 markus 1941: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 1942: }
1943:
1944: /* Returns true if there is not too much data to write to the connection. */
1945:
1.2 provos 1946: int
1.201 markus 1947: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 1948: {
1.201 markus 1949: if (ssh->state->interactive_mode)
1950: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 1951: else
1.201 markus 1952: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 1953: }
1954:
1.201 markus 1955: void
1956: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 1957: {
1.201 markus 1958: if (!ssh_packet_connection_is_on_socket(ssh))
1.101 markus 1959: return;
1.201 markus 1960: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 1961: case AF_INET:
1962: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 1963: if (setsockopt(ssh->state->connection_in,
1.173 djm 1964: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
1965: error("setsockopt IP_TOS %d: %.100s:",
1966: tos, strerror(errno));
1967: break;
1968: case AF_INET6:
1969: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 1970: if (setsockopt(ssh->state->connection_in,
1.173 djm 1971: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
1972: error("setsockopt IPV6_TCLASS %d: %.100s:",
1973: tos, strerror(errno));
1974: break;
1975: }
1.101 markus 1976: }
1977:
1.1 deraadt 1978: /* Informs that the current session is interactive. Sets IP flags for that. */
1979:
1.2 provos 1980: void
1.201 markus 1981: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 1982: {
1.201 markus 1983: struct session_state *state = ssh->state;
1984:
1985: if (state->set_interactive_called)
1.43 markus 1986: return;
1.201 markus 1987: state->set_interactive_called = 1;
1.1 deraadt 1988:
1.14 markus 1989: /* Record that we are in interactive mode. */
1.201 markus 1990: state->interactive_mode = interactive;
1.1 deraadt 1991:
1.19 markus 1992: /* Only set socket options if using a socket. */
1.201 markus 1993: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 1994: return;
1.201 markus 1995: set_nodelay(state->connection_in);
1996: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
1997: qos_bulk);
1.1 deraadt 1998: }
1999:
2000: /* Returns true if the current connection is interactive. */
2001:
1.2 provos 2002: int
1.201 markus 2003: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2004: {
1.201 markus 2005: return ssh->state->interactive_mode;
1.12 markus 2006: }
2007:
1.113 deraadt 2008: int
1.201 markus 2009: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2010: {
1.201 markus 2011: struct session_state *state = ssh->state;
2012:
2013: if (state->set_maxsize_called) {
1.106 itojun 2014: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2015: state->max_packet_size, s);
1.14 markus 2016: return -1;
2017: }
2018: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2019: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2020: return -1;
2021: }
1.201 markus 2022: state->set_maxsize_called = 1;
1.66 markus 2023: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2024: state->max_packet_size = s;
1.14 markus 2025: return s;
1.53 markus 2026: }
2027:
1.161 andreas 2028: int
1.201 markus 2029: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2030: {
1.201 markus 2031: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2032: }
2033:
2034: void
1.201 markus 2035: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2036: {
1.201 markus 2037: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2038: }
2039:
2040: u_int
1.201 markus 2041: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2042: {
1.201 markus 2043: return ssh->state->max_packet_size;
1.71 markus 2044: }
2045:
1.53 markus 2046: /*
2047: * 9.2. Ignored Data Message
1.61 markus 2048: *
1.53 markus 2049: * byte SSH_MSG_IGNORE
2050: * string data
1.61 markus 2051: *
1.53 markus 2052: * All implementations MUST understand (and ignore) this message at any
2053: * time (after receiving the protocol version). No implementation is
2054: * required to send them. This message can be used as an additional
2055: * protection measure against advanced traffic analysis techniques.
2056: */
1.54 markus 2057: void
1.201 markus 2058: ssh_packet_send_ignore(struct ssh *ssh, int nbytes)
1.54 markus 2059: {
1.115 avsm 2060: u_int32_t rnd = 0;
1.201 markus 2061: int r, i;
1.54 markus 2062:
1.249 djm 2063: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
1.201 markus 2064: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2065: fatal("%s: %s", __func__, ssh_err(r));
1.75 deraadt 2066: for (i = 0; i < nbytes; i++) {
1.53 markus 2067: if (i % 4 == 0)
1.115 avsm 2068: rnd = arc4random();
1.201 markus 2069: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2070: fatal("%s: %s", __func__, ssh_err(r));
1.115 avsm 2071: rnd >>= 8;
1.53 markus 2072: }
1.105 markus 2073: }
2074:
2075: void
1.244 dtucker 2076: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2077: {
1.244 dtucker 2078: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2079: (unsigned int)seconds);
1.201 markus 2080: ssh->state->rekey_limit = bytes;
2081: ssh->state->rekey_interval = seconds;
1.184 dtucker 2082: }
2083:
2084: time_t
1.201 markus 2085: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2086: {
2087: time_t seconds;
2088:
1.201 markus 2089: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2090: monotime();
1.185 dtucker 2091: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2092: }
2093:
2094: void
1.201 markus 2095: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2096: {
1.201 markus 2097: ssh->state->server_side = 1;
1.118 markus 2098: }
2099:
2100: void
1.201 markus 2101: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2102: {
1.201 markus 2103: ssh->state->after_authentication = 1;
1.161 andreas 2104: }
2105:
2106: void *
1.201 markus 2107: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2108: {
1.201 markus 2109: return (void *)ssh->state->input;
1.161 andreas 2110: }
2111:
2112: void *
1.201 markus 2113: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2114: {
1.201 markus 2115: return (void *)ssh->state->output;
1.166 andreas 2116: }
2117:
1.196 markus 2118: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2119: static int
2120: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2121: {
1.239 djm 2122: int r;
1.196 markus 2123:
2124: debug("%s: called", __func__);
2125: /* This was set in net child, but is not visible in user child */
1.201 markus 2126: ssh->state->after_authentication = 1;
2127: ssh->state->rekeying = 0;
1.239 djm 2128: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2129: return r;
1.201 markus 2130: return 0;
2131: }
2132:
2133: /* Packet state (de-)serialization for privsep */
2134:
2135: /* turn kex into a blob for packet state serialization */
2136: static int
2137: kex_to_blob(struct sshbuf *m, struct kex *kex)
2138: {
2139: int r;
2140:
2141: if ((r = sshbuf_put_string(m, kex->session_id,
2142: kex->session_id_len)) != 0 ||
2143: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2144: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2145: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2146: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2147: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2148: (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2149: (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2150: (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2151: return r;
2152: return 0;
2153: }
2154:
2155: /* turn key exchange results into a blob for packet state serialization */
2156: static int
2157: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2158: {
2159: struct sshbuf *b;
2160: struct sshcipher_ctx *cc;
2161: struct sshcomp *comp;
2162: struct sshenc *enc;
2163: struct sshmac *mac;
2164: struct newkeys *newkey;
2165: int r;
2166:
2167: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2168: return SSH_ERR_INTERNAL_ERROR;
2169: enc = &newkey->enc;
2170: mac = &newkey->mac;
2171: comp = &newkey->comp;
1.235 djm 2172: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2173: ssh->state->receive_context;
1.201 markus 2174: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2175: return r;
2176: if ((b = sshbuf_new()) == NULL)
2177: return SSH_ERR_ALLOC_FAIL;
2178: /* The cipher struct is constant and shared, you export pointer */
2179: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2180: (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2181: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2182: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2183: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2184: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2185: goto out;
2186: if (cipher_authlen(enc->cipher) == 0) {
2187: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2188: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2189: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2190: goto out;
2191: }
2192: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2193: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2194: goto out;
2195: r = sshbuf_put_stringb(m, b);
2196: out:
1.221 mmcc 2197: sshbuf_free(b);
1.201 markus 2198: return r;
2199: }
2200:
2201: /* serialize packet state into a blob */
2202: int
2203: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2204: {
2205: struct session_state *state = ssh->state;
1.249 djm 2206: int r;
1.201 markus 2207:
1.249 djm 2208: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2209: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2210: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2211: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2212: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2213: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2214: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2215: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2216: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2217: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2218: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2219: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
2220: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0)
2221: return r;
1.201 markus 2222:
2223: return 0;
2224: }
2225:
2226: /* restore key exchange results from blob for packet state de-serialization */
2227: static int
2228: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2229: {
2230: struct sshbuf *b = NULL;
2231: struct sshcomp *comp;
2232: struct sshenc *enc;
2233: struct sshmac *mac;
2234: struct newkeys *newkey = NULL;
2235: size_t keylen, ivlen, maclen;
2236: int r;
2237:
2238: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2239: r = SSH_ERR_ALLOC_FAIL;
2240: goto out;
2241: }
2242: if ((r = sshbuf_froms(m, &b)) != 0)
2243: goto out;
2244: #ifdef DEBUG_PK
2245: sshbuf_dump(b, stderr);
2246: #endif
2247: enc = &newkey->enc;
2248: mac = &newkey->mac;
2249: comp = &newkey->comp;
2250:
2251: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2252: (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2253: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2254: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2255: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2256: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2257: goto out;
2258: if (cipher_authlen(enc->cipher) == 0) {
2259: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2260: goto out;
2261: if ((r = mac_setup(mac, mac->name)) != 0)
2262: goto out;
2263: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2264: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2265: goto out;
2266: if (maclen > mac->key_len) {
2267: r = SSH_ERR_INVALID_FORMAT;
2268: goto out;
2269: }
2270: mac->key_len = maclen;
2271: }
2272: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2273: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2274: goto out;
2275: if (enc->name == NULL ||
2276: cipher_by_name(enc->name) != enc->cipher) {
2277: r = SSH_ERR_INVALID_FORMAT;
2278: goto out;
2279: }
2280: if (sshbuf_len(b) != 0) {
2281: r = SSH_ERR_INVALID_FORMAT;
2282: goto out;
2283: }
2284: enc->key_len = keylen;
2285: enc->iv_len = ivlen;
2286: ssh->kex->newkeys[mode] = newkey;
2287: newkey = NULL;
2288: r = 0;
2289: out:
1.219 mmcc 2290: free(newkey);
1.221 mmcc 2291: sshbuf_free(b);
1.201 markus 2292: return r;
2293: }
2294:
2295: /* restore kex from blob for packet state de-serialization */
2296: static int
2297: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2298: {
2299: struct kex *kex;
2300: int r;
2301:
2302: if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2303: (kex->my = sshbuf_new()) == NULL ||
2304: (kex->peer = sshbuf_new()) == NULL) {
2305: r = SSH_ERR_ALLOC_FAIL;
2306: goto out;
2307: }
2308: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2309: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2310: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2311: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2312: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2313: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2314: (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2315: (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2316: (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2317: goto out;
2318: kex->server = 1;
2319: kex->done = 1;
2320: r = 0;
2321: out:
2322: if (r != 0 || kexp == NULL) {
2323: if (kex != NULL) {
1.221 mmcc 2324: sshbuf_free(kex->my);
2325: sshbuf_free(kex->peer);
1.201 markus 2326: free(kex);
2327: }
2328: if (kexp != NULL)
2329: *kexp = NULL;
2330: } else {
2331: *kexp = kex;
2332: }
2333: return r;
2334: }
2335:
2336: /*
2337: * Restore packet state from content of blob 'm' (de-serialization).
2338: * Note that 'm' will be partially consumed on parsing or any other errors.
2339: */
2340: int
2341: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2342: {
2343: struct session_state *state = ssh->state;
1.254 ! djm 2344: const u_char *input, *output;
! 2345: size_t ilen, olen;
1.201 markus 2346: int r;
2347:
1.249 djm 2348: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2349: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2350: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2351: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2352: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2353: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2354: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2355: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2356: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2357: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2358: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2359: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2360: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2361: return r;
2362: /*
2363: * We set the time here so that in post-auth privsep slave we
2364: * count from the completion of the authentication.
2365: */
2366: state->rekey_time = monotime();
2367: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2368: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2369: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2370: return r;
1.201 markus 2371:
1.239 djm 2372: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2373: return r;
2374:
2375: sshbuf_reset(state->input);
2376: sshbuf_reset(state->output);
2377: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2378: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2379: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2380: (r = sshbuf_put(state->output, output, olen)) != 0)
2381: return r;
2382:
2383: if (sshbuf_len(m))
2384: return SSH_ERR_INVALID_FORMAT;
2385: debug3("%s: done", __func__);
2386: return 0;
2387: }
2388:
2389: /* NEW API */
2390:
2391: /* put data to the outgoing packet */
2392:
2393: int
2394: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2395: {
2396: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2397: }
2398:
2399: int
2400: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2401: {
2402: return sshbuf_putb(ssh->state->outgoing_packet, b);
2403: }
2404:
2405: int
2406: sshpkt_put_u8(struct ssh *ssh, u_char val)
2407: {
2408: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2409: }
2410:
2411: int
2412: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2413: {
2414: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2415: }
2416:
2417: int
2418: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2419: {
2420: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2421: }
2422:
2423: int
2424: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2425: {
2426: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2427: }
2428:
2429: int
2430: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2431: {
2432: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2433: }
2434:
2435: int
2436: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2437: {
2438: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2439: }
2440:
1.211 djm 2441: #ifdef WITH_OPENSSL
1.201 markus 2442: int
2443: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2444: {
2445: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2446: }
2447:
2448:
2449: int
2450: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2451: {
2452: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2453: }
1.211 djm 2454: #endif /* WITH_OPENSSL */
1.201 markus 2455:
2456: /* fetch data from the incoming packet */
2457:
2458: int
2459: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2460: {
2461: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2462: }
2463:
2464: int
2465: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2466: {
2467: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2468: }
2469:
2470: int
2471: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2472: {
2473: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2474: }
2475:
2476: int
2477: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2478: {
2479: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2480: }
2481:
2482: int
2483: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2484: {
2485: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2486: }
2487:
2488: int
2489: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2490: {
2491: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2492: }
2493:
2494: int
2495: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2496: {
2497: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2498: }
2499:
1.211 djm 2500: #ifdef WITH_OPENSSL
1.201 markus 2501: int
2502: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2503: {
2504: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2505: }
2506:
2507:
2508: int
2509: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2510: {
2511: return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2512: }
1.211 djm 2513: #endif /* WITH_OPENSSL */
1.201 markus 2514:
2515: int
2516: sshpkt_get_end(struct ssh *ssh)
2517: {
2518: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2519: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2520: return 0;
2521: }
2522:
2523: const u_char *
2524: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2525: {
2526: if (lenp != NULL)
2527: *lenp = sshbuf_len(ssh->state->incoming_packet);
2528: return sshbuf_ptr(ssh->state->incoming_packet);
2529: }
2530:
2531: /* start a new packet */
2532:
2533: int
2534: sshpkt_start(struct ssh *ssh, u_char type)
2535: {
1.249 djm 2536: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2537:
2538: DBG(debug("packet_start[%d]", type));
1.249 djm 2539: memset(buf, 0, sizeof(buf));
2540: buf[sizeof(buf) - 1] = type;
1.201 markus 2541: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2542: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2543: }
2544:
1.242 markus 2545: static int
2546: ssh_packet_send_mux(struct ssh *ssh)
2547: {
2548: struct session_state *state = ssh->state;
2549: u_char type, *cp;
2550: size_t len;
2551: int r;
2552:
2553: if (ssh->kex)
2554: return SSH_ERR_INTERNAL_ERROR;
2555: len = sshbuf_len(state->outgoing_packet);
2556: if (len < 6)
2557: return SSH_ERR_INTERNAL_ERROR;
2558: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2559: type = cp[5];
2560: if (ssh_packet_log_type(type))
2561: debug3("%s: type %u", __func__, type);
2562: /* drop everything, but the connection protocol */
2563: if (type >= SSH2_MSG_CONNECTION_MIN &&
2564: type <= SSH2_MSG_CONNECTION_MAX) {
2565: POKE_U32(cp, len - 4);
2566: if ((r = sshbuf_putb(state->output,
2567: state->outgoing_packet)) != 0)
2568: return r;
2569: /* sshbuf_dump(state->output, stderr); */
2570: }
2571: sshbuf_reset(state->outgoing_packet);
2572: return 0;
2573: }
2574:
1.201 markus 2575: /* send it */
2576:
2577: int
2578: sshpkt_send(struct ssh *ssh)
2579: {
1.242 markus 2580: if (ssh->state && ssh->state->mux)
2581: return ssh_packet_send_mux(ssh);
1.249 djm 2582: return ssh_packet_send2(ssh);
1.201 markus 2583: }
2584:
2585: int
2586: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2587: {
2588: char buf[1024];
2589: va_list args;
2590: int r;
2591:
2592: va_start(args, fmt);
2593: vsnprintf(buf, sizeof(buf), fmt, args);
2594: va_end(args);
2595:
1.249 djm 2596: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2597: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2598: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2599: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2600: (r = sshpkt_send(ssh)) != 0)
2601: return r;
1.201 markus 2602: return 0;
2603: }
2604:
2605: /* roundup current message to pad bytes */
2606: int
2607: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2608: {
2609: ssh->state->extra_pad = pad;
2610: return 0;
1.1 deraadt 2611: }
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