Annotation of src/usr.bin/ssh/packet.c, Revision 1.265
1.265 ! djm 1: /* $OpenBSD: packet.c,v 1.264 2017/09/12 06:32:07 djm Exp $ */
1.1 deraadt 2: /*
1.15 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.35 deraadt 6: * This file contains code implementing the packet protocol and communication
7: * with the other side. This same code is used both on client and server side.
1.29 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
1.29 markus 14: *
1.25 markus 15: *
16: * SSH2 packet format added by Markus Friedl.
1.69 markus 17: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.25 markus 18: *
1.35 deraadt 19: * Redistribution and use in source and binary forms, with or without
20: * modification, are permitted provided that the following conditions
21: * are met:
22: * 1. Redistributions of source code must retain the above copyright
23: * notice, this list of conditions and the following disclaimer.
24: * 2. Redistributions in binary form must reproduce the above copyright
25: * notice, this list of conditions and the following disclaimer in the
26: * documentation and/or other materials provided with the distribution.
27: *
28: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15 deraadt 38: */
1.1 deraadt 39:
1.142 deraadt 40: #include <sys/types.h>
1.105 markus 41: #include <sys/queue.h>
1.132 stevesk 42: #include <sys/socket.h>
1.138 stevesk 43: #include <sys/time.h>
1.132 stevesk 44: #include <netinet/in.h>
1.121 stevesk 45: #include <netinet/ip.h>
1.134 stevesk 46:
1.135 stevesk 47: #include <errno.h>
1.230 djm 48: #include <netdb.h>
1.134 stevesk 49: #include <stdarg.h>
1.141 stevesk 50: #include <stdio.h>
1.140 stevesk 51: #include <stdlib.h>
1.137 stevesk 52: #include <string.h>
1.136 stevesk 53: #include <unistd.h>
1.203 deraadt 54: #include <limits.h>
1.142 deraadt 55: #include <signal.h>
1.184 dtucker 56: #include <time.h>
1.1 deraadt 57:
1.201 markus 58: #include <zlib.h>
59:
60: #include "buffer.h" /* typedefs XXX */
61: #include "key.h" /* typedefs XXX */
62:
1.1 deraadt 63: #include "xmalloc.h"
64: #include "crc32.h"
1.25 markus 65: #include "compat.h"
66: #include "ssh2.h"
1.37 markus 67: #include "cipher.h"
1.201 markus 68: #include "sshkey.h"
1.25 markus 69: #include "kex.h"
1.200 markus 70: #include "digest.h"
1.50 markus 71: #include "mac.h"
1.46 markus 72: #include "log.h"
73: #include "canohost.h"
1.87 stevesk 74: #include "misc.h"
1.198 millert 75: #include "channels.h"
1.95 markus 76: #include "ssh.h"
1.201 markus 77: #include "packet.h"
1.197 djm 78: #include "ssherr.h"
1.201 markus 79: #include "sshbuf.h"
1.25 markus 80:
81: #ifdef PACKET_DEBUG
82: #define DBG(x) x
83: #else
84: #define DBG(x)
85: #endif
86:
1.159 markus 87: #define PACKET_MAX_SIZE (256 * 1024)
88:
1.161 andreas 89: struct packet_state {
90: u_int32_t seqnr;
91: u_int32_t packets;
92: u_int64_t blocks;
93: u_int64_t bytes;
94: };
95:
96: struct packet {
97: TAILQ_ENTRY(packet) next;
98: u_char type;
1.201 markus 99: struct sshbuf *payload;
1.161 andreas 100: };
101:
102: struct session_state {
103: /*
104: * This variable contains the file descriptors used for
105: * communicating with the other side. connection_in is used for
106: * reading; connection_out for writing. These can be the same
107: * descriptor, in which case it is assumed to be a socket.
108: */
109: int connection_in;
110: int connection_out;
111:
112: /* Protocol flags for the remote side. */
113: u_int remote_protocol_flags;
1.1 deraadt 114:
1.161 andreas 115: /* Encryption context for receiving data. Only used for decryption. */
1.235 djm 116: struct sshcipher_ctx *receive_context;
1.1 deraadt 117:
1.161 andreas 118: /* Encryption context for sending data. Only used for encryption. */
1.235 djm 119: struct sshcipher_ctx *send_context;
1.14 markus 120:
1.161 andreas 121: /* Buffer for raw input data from the socket. */
1.201 markus 122: struct sshbuf *input;
1.1 deraadt 123:
1.161 andreas 124: /* Buffer for raw output data going to the socket. */
1.201 markus 125: struct sshbuf *output;
1.1 deraadt 126:
1.161 andreas 127: /* Buffer for the partial outgoing packet being constructed. */
1.201 markus 128: struct sshbuf *outgoing_packet;
1.1 deraadt 129:
1.161 andreas 130: /* Buffer for the incoming packet currently being processed. */
1.201 markus 131: struct sshbuf *incoming_packet;
1.1 deraadt 132:
1.161 andreas 133: /* Scratch buffer for packet compression/decompression. */
1.201 markus 134: struct sshbuf *compression_buffer;
135:
136: /* Incoming/outgoing compression dictionaries */
137: z_stream compression_in_stream;
138: z_stream compression_out_stream;
139: int compression_in_started;
140: int compression_out_started;
141: int compression_in_failures;
142: int compression_out_failures;
1.1 deraadt 143:
1.161 andreas 144: /*
145: * Flag indicating whether packet compression/decompression is
146: * enabled.
147: */
148: int packet_compression;
1.1 deraadt 149:
1.161 andreas 150: /* default maximum packet size */
151: u_int max_packet_size;
1.1 deraadt 152:
1.161 andreas 153: /* Flag indicating whether this module has been initialized. */
154: int initialized;
1.12 markus 155:
1.161 andreas 156: /* Set to true if the connection is interactive. */
157: int interactive_mode;
1.1 deraadt 158:
1.161 andreas 159: /* Set to true if we are the server side. */
160: int server_side;
1.1 deraadt 161:
1.161 andreas 162: /* Set to true if we are authenticated. */
163: int after_authentication;
1.118 markus 164:
1.161 andreas 165: int keep_alive_timeouts;
1.118 markus 166:
1.161 andreas 167: /* The maximum time that we will wait to send or receive a packet */
168: int packet_timeout_ms;
1.151 dtucker 169:
1.161 andreas 170: /* Session key information for Encryption and MAC */
1.201 markus 171: struct newkeys *newkeys[MODE_MAX];
1.161 andreas 172: struct packet_state p_read, p_send;
1.154 dtucker 173:
1.184 dtucker 174: /* Volume-based rekeying */
1.224 dtucker 175: u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
1.105 markus 176:
1.184 dtucker 177: /* Time-based rekeying */
1.208 markus 178: u_int32_t rekey_interval; /* how often in seconds */
1.184 dtucker 179: time_t rekey_time; /* time of last rekeying */
180:
1.161 andreas 181: /* roundup current message to extra_pad bytes */
182: u_char extra_pad;
1.95 markus 183:
1.161 andreas 184: /* XXX discard incoming data after MAC error */
185: u_int packet_discard;
1.234 markus 186: size_t packet_discard_mac_already;
1.201 markus 187: struct sshmac *packet_discard_mac;
1.71 markus 188:
1.161 andreas 189: /* Used in packet_read_poll2() */
190: u_int packlen;
1.159 markus 191:
1.165 andreas 192: /* Used in packet_send2 */
193: int rekeying;
194:
1.242 markus 195: /* Used in ssh_packet_send_mux() */
196: int mux;
197:
1.165 andreas 198: /* Used in packet_set_interactive */
199: int set_interactive_called;
200:
201: /* Used in packet_set_maxsize */
202: int set_maxsize_called;
203:
1.201 markus 204: /* One-off warning about weak ciphers */
205: int cipher_warning_done;
206:
1.243 djm 207: /* Hook for fuzzing inbound packets */
208: ssh_packet_hook_fn *hook_in;
209: void *hook_in_ctx;
210:
1.161 andreas 211: TAILQ_HEAD(, packet) outgoing;
1.105 markus 212: };
1.161 andreas 213:
1.201 markus 214: struct ssh *
215: ssh_alloc_session_state(void)
1.161 andreas 216: {
1.201 markus 217: struct ssh *ssh = NULL;
218: struct session_state *state = NULL;
1.161 andreas 219:
1.201 markus 220: if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
221: (state = calloc(1, sizeof(*state))) == NULL ||
222: (state->input = sshbuf_new()) == NULL ||
223: (state->output = sshbuf_new()) == NULL ||
224: (state->outgoing_packet = sshbuf_new()) == NULL ||
225: (state->incoming_packet = sshbuf_new()) == NULL)
226: goto fail;
227: TAILQ_INIT(&state->outgoing);
1.202 markus 228: TAILQ_INIT(&ssh->private_keys);
229: TAILQ_INIT(&ssh->public_keys);
1.201 markus 230: state->connection_in = -1;
231: state->connection_out = -1;
232: state->max_packet_size = 32768;
233: state->packet_timeout_ms = -1;
234: state->p_send.packets = state->p_read.packets = 0;
235: state->initialized = 1;
236: /*
237: * ssh_packet_send2() needs to queue packets until
238: * we've done the initial key exchange.
239: */
240: state->rekeying = 1;
241: ssh->state = state;
242: return ssh;
243: fail:
244: if (state) {
245: sshbuf_free(state->input);
246: sshbuf_free(state->output);
247: sshbuf_free(state->incoming_packet);
248: sshbuf_free(state->outgoing_packet);
249: free(state);
250: }
251: free(ssh);
252: return NULL;
1.161 andreas 253: }
1.105 markus 254:
1.243 djm 255: void
256: ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
257: {
258: ssh->state->hook_in = hook;
259: ssh->state->hook_in_ctx = ctx;
260: }
261:
1.228 djm 262: /* Returns nonzero if rekeying is in progress */
263: int
264: ssh_packet_is_rekeying(struct ssh *ssh)
265: {
1.249 djm 266: return ssh->state->rekeying ||
267: (ssh->kex != NULL && ssh->kex->done == 0);
1.228 djm 268: }
269:
1.16 markus 270: /*
1.253 naddy 271: * Sets the descriptors used for communication.
1.16 markus 272: */
1.201 markus 273: struct ssh *
274: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1 deraadt 275: {
1.201 markus 276: struct session_state *state;
277: const struct sshcipher *none = cipher_by_name("none");
1.197 djm 278: int r;
1.97 deraadt 279:
1.205 djm 280: if (none == NULL) {
281: error("%s: cannot load cipher 'none'", __func__);
282: return NULL;
283: }
1.201 markus 284: if (ssh == NULL)
285: ssh = ssh_alloc_session_state();
1.205 djm 286: if (ssh == NULL) {
287: error("%s: cound not allocate state", __func__);
288: return NULL;
289: }
1.201 markus 290: state = ssh->state;
291: state->connection_in = fd_in;
292: state->connection_out = fd_out;
293: if ((r = cipher_init(&state->send_context, none,
1.197 djm 294: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201 markus 295: (r = cipher_init(&state->receive_context, none,
1.205 djm 296: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
297: error("%s: cipher_init failed: %s", __func__, ssh_err(r));
1.230 djm 298: free(ssh); /* XXX need ssh_free_session_state? */
1.205 djm 299: return NULL;
300: }
1.201 markus 301: state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
1.207 djm 302: /*
303: * Cache the IP address of the remote connection for use in error
304: * messages that might be generated after the connection has closed.
305: */
306: (void)ssh_remote_ipaddr(ssh);
1.201 markus 307: return ssh;
1.1 deraadt 308: }
309:
1.154 dtucker 310: void
1.201 markus 311: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 312: {
1.201 markus 313: struct session_state *state = ssh->state;
314:
1.174 djm 315: if (timeout <= 0 || count <= 0) {
1.201 markus 316: state->packet_timeout_ms = -1;
1.154 dtucker 317: return;
318: }
319: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 320: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 321: else
1.201 markus 322: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 323: }
324:
1.242 markus 325: void
326: ssh_packet_set_mux(struct ssh *ssh)
327: {
328: ssh->state->mux = 1;
329: ssh->state->rekeying = 0;
330: }
331:
332: int
333: ssh_packet_get_mux(struct ssh *ssh)
334: {
335: return ssh->state->mux;
336: }
337:
1.201 markus 338: int
1.245 djm 339: ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
340: {
341: va_list args;
342: int r;
343:
344: free(ssh->log_preamble);
345: if (fmt == NULL)
346: ssh->log_preamble = NULL;
347: else {
348: va_start(args, fmt);
349: r = vasprintf(&ssh->log_preamble, fmt, args);
350: va_end(args);
351: if (r < 0 || ssh->log_preamble == NULL)
352: return SSH_ERR_ALLOC_FAIL;
353: }
354: return 0;
355: }
356:
357: int
1.201 markus 358: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 359: {
1.201 markus 360: struct session_state *state = ssh->state;
361: int r;
362:
363: if (state->packet_discard_mac) {
1.159 markus 364: char buf[1024];
1.234 markus 365: size_t dlen = PACKET_MAX_SIZE;
1.201 markus 366:
1.234 markus 367: if (dlen > state->packet_discard_mac_already)
368: dlen -= state->packet_discard_mac_already;
1.159 markus 369: memset(buf, 'a', sizeof(buf));
1.234 markus 370: while (sshbuf_len(state->incoming_packet) < dlen)
1.201 markus 371: if ((r = sshbuf_put(state->incoming_packet, buf,
372: sizeof(buf))) != 0)
373: return r;
374: (void) mac_compute(state->packet_discard_mac,
375: state->p_read.seqnr,
1.234 markus 376: sshbuf_ptr(state->incoming_packet), dlen,
1.201 markus 377: NULL, 0);
1.159 markus 378: }
1.220 djm 379: logit("Finished discarding for %.200s port %d",
380: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 381: return SSH_ERR_MAC_INVALID;
1.159 markus 382: }
383:
1.201 markus 384: static int
385: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
1.234 markus 386: struct sshmac *mac, size_t mac_already, u_int discard)
1.159 markus 387: {
1.201 markus 388: struct session_state *state = ssh->state;
389: int r;
390:
391: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
392: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
393: return r;
394: return SSH_ERR_MAC_INVALID;
395: }
1.234 markus 396: /*
397: * Record number of bytes over which the mac has already
398: * been computed in order to minimize timing attacks.
399: */
400: if (mac && mac->enabled) {
1.201 markus 401: state->packet_discard_mac = mac;
1.234 markus 402: state->packet_discard_mac_already = mac_already;
403: }
404: if (sshbuf_len(state->input) >= discard)
405: return ssh_packet_stop_discard(ssh);
1.201 markus 406: state->packet_discard = discard - sshbuf_len(state->input);
407: return 0;
1.159 markus 408: }
409:
1.19 markus 410: /* Returns 1 if remote host is connected via socket, 0 if not. */
411:
412: int
1.201 markus 413: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 414: {
1.201 markus 415: struct session_state *state = ssh->state;
1.19 markus 416: struct sockaddr_storage from, to;
417: socklen_t fromlen, tolen;
418:
1.230 djm 419: if (state->connection_in == -1 || state->connection_out == -1)
420: return 0;
421:
1.19 markus 422: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 423: if (state->connection_in == state->connection_out)
1.19 markus 424: return 1;
425: fromlen = sizeof(from);
426: memset(&from, 0, sizeof(from));
1.201 markus 427: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.161 andreas 428: &fromlen) < 0)
1.19 markus 429: return 0;
430: tolen = sizeof(to);
431: memset(&to, 0, sizeof(to));
1.201 markus 432: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.161 andreas 433: &tolen) < 0)
1.19 markus 434: return 0;
435: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
436: return 0;
437: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
438: return 0;
439: return 1;
440: }
441:
1.91 markus 442: void
1.201 markus 443: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 444: {
1.201 markus 445: if (ibytes)
446: *ibytes = ssh->state->p_read.bytes;
447: if (obytes)
448: *obytes = ssh->state->p_send.bytes;
1.91 markus 449: }
1.125 deraadt 450:
1.91 markus 451: int
1.201 markus 452: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 453: {
454: struct sockaddr_storage to;
1.21 deraadt 455: socklen_t tolen = sizeof(to);
1.19 markus 456:
457: memset(&to, 0, sizeof(to));
1.201 markus 458: if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
1.161 andreas 459: &tolen) < 0)
1.19 markus 460: return 0;
1.173 djm 461: return to.ss_family;
1.19 markus 462: }
463:
1.1 deraadt 464: /* Sets the connection into non-blocking mode. */
465:
1.2 provos 466: void
1.201 markus 467: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 468: {
1.14 markus 469: /* Set the socket into non-blocking mode. */
1.201 markus 470: set_nonblock(ssh->state->connection_in);
1.14 markus 471:
1.201 markus 472: if (ssh->state->connection_out != ssh->state->connection_in)
473: set_nonblock(ssh->state->connection_out);
1.1 deraadt 474: }
475:
476: /* Returns the socket used for reading. */
477:
1.2 provos 478: int
1.201 markus 479: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 480: {
1.201 markus 481: return ssh->state->connection_in;
1.1 deraadt 482: }
483:
484: /* Returns the descriptor used for writing. */
485:
1.2 provos 486: int
1.201 markus 487: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 488: {
1.201 markus 489: return ssh->state->connection_out;
490: }
491:
492: /*
493: * Returns the IP-address of the remote host as a string. The returned
494: * string must not be freed.
495: */
496:
497: const char *
498: ssh_remote_ipaddr(struct ssh *ssh)
499: {
1.220 djm 500: const int sock = ssh->state->connection_in;
501:
1.201 markus 502: /* Check whether we have cached the ipaddr. */
1.220 djm 503: if (ssh->remote_ipaddr == NULL) {
504: if (ssh_packet_connection_is_on_socket(ssh)) {
505: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 djm 506: ssh->remote_port = get_peer_port(sock);
507: ssh->local_ipaddr = get_local_ipaddr(sock);
508: ssh->local_port = get_local_port(sock);
1.220 djm 509: } else {
510: ssh->remote_ipaddr = strdup("UNKNOWN");
1.230 djm 511: ssh->remote_port = 65535;
512: ssh->local_ipaddr = strdup("UNKNOWN");
513: ssh->local_port = 65535;
1.220 djm 514: }
515: }
1.201 markus 516: return ssh->remote_ipaddr;
1.1 deraadt 517: }
518:
1.220 djm 519: /* Returns the port number of the remote host. */
520:
521: int
522: ssh_remote_port(struct ssh *ssh)
523: {
524: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
525: return ssh->remote_port;
1.230 djm 526: }
527:
528: /*
529: * Returns the IP-address of the local host as a string. The returned
530: * string must not be freed.
531: */
532:
533: const char *
534: ssh_local_ipaddr(struct ssh *ssh)
535: {
536: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
537: return ssh->local_ipaddr;
538: }
539:
540: /* Returns the port number of the local host. */
541:
542: int
543: ssh_local_port(struct ssh *ssh)
544: {
545: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
546: return ssh->local_port;
1.220 djm 547: }
548:
1.1 deraadt 549: /* Closes the connection and clears and frees internal data structures. */
550:
1.257 markus 551: static void
552: ssh_packet_close_internal(struct ssh *ssh, int do_close)
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;
1.257 markus 560: if (do_close) {
561: if (state->connection_in == state->connection_out) {
562: close(state->connection_out);
563: } else {
564: close(state->connection_in);
565: close(state->connection_out);
566: }
1.14 markus 567: }
1.201 markus 568: sshbuf_free(state->input);
569: sshbuf_free(state->output);
570: sshbuf_free(state->outgoing_packet);
571: sshbuf_free(state->incoming_packet);
1.257 markus 572: for (mode = 0; mode < MODE_MAX; mode++) {
573: kex_free_newkeys(state->newkeys[mode]); /* current keys */
574: state->newkeys[mode] = NULL;
575: ssh_clear_newkeys(ssh, mode); /* next keys */
576: }
577: /* comression state is in shared mem, so we can only release it once */
578: if (do_close && state->compression_buffer) {
1.201 markus 579: sshbuf_free(state->compression_buffer);
580: if (state->compression_out_started) {
581: z_streamp stream = &state->compression_out_stream;
582: debug("compress outgoing: "
583: "raw data %llu, compressed %llu, factor %.2f",
584: (unsigned long long)stream->total_in,
585: (unsigned long long)stream->total_out,
586: stream->total_in == 0 ? 0.0 :
587: (double) stream->total_out / stream->total_in);
588: if (state->compression_out_failures == 0)
589: deflateEnd(stream);
590: }
591: if (state->compression_in_started) {
1.260 dtucker 592: z_streamp stream = &state->compression_in_stream;
1.201 markus 593: debug("compress incoming: "
594: "raw data %llu, compressed %llu, factor %.2f",
595: (unsigned long long)stream->total_out,
596: (unsigned long long)stream->total_in,
597: stream->total_out == 0 ? 0.0 :
598: (double) stream->total_in / stream->total_out);
599: if (state->compression_in_failures == 0)
600: inflateEnd(stream);
601: }
1.14 markus 602: }
1.235 djm 603: cipher_free(state->send_context);
604: cipher_free(state->receive_context);
605: state->send_context = state->receive_context = NULL;
1.257 markus 606: if (do_close) {
607: free(ssh->remote_ipaddr);
608: ssh->remote_ipaddr = NULL;
609: free(ssh->state);
610: ssh->state = NULL;
611: }
612: }
613:
614: void
615: ssh_packet_close(struct ssh *ssh)
616: {
617: ssh_packet_close_internal(ssh, 1);
618: }
619:
620: void
621: ssh_packet_clear_keys(struct ssh *ssh)
622: {
623: ssh_packet_close_internal(ssh, 0);
1.1 deraadt 624: }
625:
626: /* Sets remote side protocol flags. */
627:
1.2 provos 628: void
1.201 markus 629: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 630: {
1.201 markus 631: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 632: }
633:
634: /* Returns the remote protocol flags set earlier by the above function. */
635:
1.40 markus 636: u_int
1.201 markus 637: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 638: {
1.201 markus 639: return ssh->state->remote_protocol_flags;
1.1 deraadt 640: }
641:
1.16 markus 642: /*
643: * Starts packet compression from the next packet on in both directions.
644: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
645: */
1.1 deraadt 646:
1.201 markus 647: static int
648: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 649: {
1.201 markus 650: if (!ssh->state->compression_buffer &&
651: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
652: return SSH_ERR_ALLOC_FAIL;
653: return 0;
1.60 markus 654: }
655:
1.201 markus 656: static int
657: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 658: {
1.201 markus 659: if (level < 1 || level > 9)
660: return SSH_ERR_INVALID_ARGUMENT;
661: debug("Enabling compression at level %d.", level);
662: if (ssh->state->compression_out_started == 1)
663: deflateEnd(&ssh->state->compression_out_stream);
664: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
665: case Z_OK:
666: ssh->state->compression_out_started = 1;
667: break;
668: case Z_MEM_ERROR:
669: return SSH_ERR_ALLOC_FAIL;
670: default:
671: return SSH_ERR_INTERNAL_ERROR;
672: }
673: return 0;
1.1 deraadt 674: }
675:
1.201 markus 676: static int
677: start_compression_in(struct ssh *ssh)
678: {
679: if (ssh->state->compression_in_started == 1)
680: inflateEnd(&ssh->state->compression_in_stream);
681: switch (inflateInit(&ssh->state->compression_in_stream)) {
682: case Z_OK:
683: ssh->state->compression_in_started = 1;
684: break;
685: case Z_MEM_ERROR:
686: return SSH_ERR_ALLOC_FAIL;
687: default:
688: return SSH_ERR_INTERNAL_ERROR;
689: }
690: return 0;
691: }
1.95 markus 692:
1.201 markus 693: int
694: ssh_packet_start_compression(struct ssh *ssh, int level)
1.1 deraadt 695: {
1.197 djm 696: int r;
1.97 deraadt 697:
1.249 djm 698: if (ssh->state->packet_compression)
1.201 markus 699: return SSH_ERR_INTERNAL_ERROR;
700: ssh->state->packet_compression = 1;
701: if ((r = ssh_packet_init_compression(ssh)) != 0 ||
702: (r = start_compression_in(ssh)) != 0 ||
703: (r = start_compression_out(ssh, level)) != 0)
704: return r;
705: return 0;
1.95 markus 706: }
707:
1.201 markus 708: /* XXX remove need for separate compression buffer */
709: static int
710: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 711: {
1.201 markus 712: u_char buf[4096];
713: int r, status;
714:
715: if (ssh->state->compression_out_started != 1)
716: return SSH_ERR_INTERNAL_ERROR;
717:
718: /* This case is not handled below. */
719: if (sshbuf_len(in) == 0)
720: return 0;
721:
722: /* Input is the contents of the input buffer. */
723: if ((ssh->state->compression_out_stream.next_in =
724: sshbuf_mutable_ptr(in)) == NULL)
725: return SSH_ERR_INTERNAL_ERROR;
726: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
727:
728: /* Loop compressing until deflate() returns with avail_out != 0. */
729: do {
730: /* Set up fixed-size output buffer. */
731: ssh->state->compression_out_stream.next_out = buf;
732: ssh->state->compression_out_stream.avail_out = sizeof(buf);
733:
734: /* Compress as much data into the buffer as possible. */
735: status = deflate(&ssh->state->compression_out_stream,
736: Z_PARTIAL_FLUSH);
737: switch (status) {
738: case Z_MEM_ERROR:
739: return SSH_ERR_ALLOC_FAIL;
740: case Z_OK:
741: /* Append compressed data to output_buffer. */
742: if ((r = sshbuf_put(out, buf, sizeof(buf) -
743: ssh->state->compression_out_stream.avail_out)) != 0)
744: return r;
745: break;
746: case Z_STREAM_ERROR:
747: default:
748: ssh->state->compression_out_failures++;
749: return SSH_ERR_INVALID_FORMAT;
750: }
751: } while (ssh->state->compression_out_stream.avail_out == 0);
752: return 0;
1.1 deraadt 753: }
754:
1.201 markus 755: static int
756: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 757: {
1.201 markus 758: u_char buf[4096];
759: int r, status;
1.1 deraadt 760:
1.201 markus 761: if (ssh->state->compression_in_started != 1)
762: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 763:
1.201 markus 764: if ((ssh->state->compression_in_stream.next_in =
765: sshbuf_mutable_ptr(in)) == NULL)
766: return SSH_ERR_INTERNAL_ERROR;
767: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 768:
1.201 markus 769: for (;;) {
770: /* Set up fixed-size output buffer. */
771: ssh->state->compression_in_stream.next_out = buf;
772: ssh->state->compression_in_stream.avail_out = sizeof(buf);
773:
774: status = inflate(&ssh->state->compression_in_stream,
775: Z_PARTIAL_FLUSH);
776: switch (status) {
777: case Z_OK:
778: if ((r = sshbuf_put(out, buf, sizeof(buf) -
779: ssh->state->compression_in_stream.avail_out)) != 0)
780: return r;
781: break;
782: case Z_BUF_ERROR:
783: /*
784: * Comments in zlib.h say that we should keep calling
785: * inflate() until we get an error. This appears to
786: * be the error that we get.
787: */
788: return 0;
789: case Z_DATA_ERROR:
790: return SSH_ERR_INVALID_FORMAT;
791: case Z_MEM_ERROR:
792: return SSH_ERR_ALLOC_FAIL;
793: case Z_STREAM_ERROR:
794: default:
795: ssh->state->compression_in_failures++;
796: return SSH_ERR_INTERNAL_ERROR;
797: }
798: }
799: /* NOTREACHED */
1.170 djm 800: }
801:
1.257 markus 802: void
803: ssh_clear_newkeys(struct ssh *ssh, int mode)
804: {
1.259 djm 805: if (ssh->kex && ssh->kex->newkeys[mode]) {
1.257 markus 806: kex_free_newkeys(ssh->kex->newkeys[mode]);
807: ssh->kex->newkeys[mode] = NULL;
808: }
809: }
810:
1.201 markus 811: int
812: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 813: {
1.201 markus 814: struct session_state *state = ssh->state;
815: struct sshenc *enc;
816: struct sshmac *mac;
817: struct sshcomp *comp;
1.235 djm 818: struct sshcipher_ctx **ccp;
1.236 markus 819: struct packet_state *ps;
1.105 markus 820: u_int64_t *max_blocks;
1.259 djm 821: const char *wmsg;
1.197 djm 822: int r, crypt_type;
1.57 markus 823:
1.100 markus 824: debug2("set_newkeys: mode %d", mode);
1.57 markus 825:
1.88 markus 826: if (mode == MODE_OUT) {
1.235 djm 827: ccp = &state->send_context;
1.115 avsm 828: crypt_type = CIPHER_ENCRYPT;
1.236 markus 829: ps = &state->p_send;
1.201 markus 830: max_blocks = &state->max_blocks_out;
1.88 markus 831: } else {
1.235 djm 832: ccp = &state->receive_context;
1.115 avsm 833: crypt_type = CIPHER_DECRYPT;
1.236 markus 834: ps = &state->p_read;
1.201 markus 835: max_blocks = &state->max_blocks_in;
1.88 markus 836: }
1.201 markus 837: if (state->newkeys[mode] != NULL) {
1.257 markus 838: debug("set_newkeys: rekeying, input %llu bytes %llu blocks, "
839: "output %llu bytes %llu blocks",
840: (unsigned long long)state->p_read.bytes,
841: (unsigned long long)state->p_read.blocks,
842: (unsigned long long)state->p_send.bytes,
843: (unsigned long long)state->p_send.blocks);
1.235 djm 844: cipher_free(*ccp);
845: *ccp = NULL;
1.257 markus 846: kex_free_newkeys(state->newkeys[mode]);
847: state->newkeys[mode] = NULL;
1.57 markus 848: }
1.236 markus 849: /* note that both bytes and the seqnr are not reset */
850: ps->packets = ps->blocks = 0;
1.201 markus 851: /* move newkeys from kex to state */
852: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
853: return SSH_ERR_INTERNAL_ERROR;
854: ssh->kex->newkeys[mode] = NULL;
855: enc = &state->newkeys[mode]->enc;
856: mac = &state->newkeys[mode]->mac;
857: comp = &state->newkeys[mode]->comp;
858: if (cipher_authlen(enc->cipher) == 0) {
859: if ((r = mac_init(mac)) != 0)
860: return r;
861: }
862: mac->enabled = 1;
1.57 markus 863: DBG(debug("cipher_init_context: %d", mode));
1.235 djm 864: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 865: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 866: return r;
867: if (!state->cipher_warning_done &&
1.235 djm 868: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 869: error("Warning: %s", wmsg);
870: state->cipher_warning_done = 1;
871: }
1.91 markus 872: /* Deleting the keys does not gain extra security */
1.192 djm 873: /* explicit_bzero(enc->iv, enc->block_size);
874: explicit_bzero(enc->key, enc->key_len);
875: explicit_bzero(mac->key, mac->key_len); */
1.241 djm 876: if ((comp->type == COMP_ZLIB ||
877: (comp->type == COMP_DELAYED &&
878: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 879: if ((r = ssh_packet_init_compression(ssh)) < 0)
880: return r;
881: if (mode == MODE_OUT) {
882: if ((r = start_compression_out(ssh, 6)) != 0)
883: return r;
884: } else {
885: if ((r = start_compression_in(ssh)) != 0)
886: return r;
887: }
1.57 markus 888: comp->enabled = 1;
889: }
1.109 markus 890: /*
891: * The 2^(blocksize*2) limit is too expensive for 3DES,
1.254 djm 892: * so enforce a 1GB limit for small blocksizes.
1.261 dtucker 893: * See RFC4344 section 3.2.
1.109 markus 894: */
895: if (enc->block_size >= 16)
896: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
897: else
898: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 899: if (state->rekey_limit)
1.237 deraadt 900: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 901: state->rekey_limit / enc->block_size);
1.227 djm 902: debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1.201 markus 903: return 0;
1.57 markus 904: }
905:
1.228 djm 906: #define MAX_PACKETS (1U<<31)
907: static int
908: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
909: {
910: struct session_state *state = ssh->state;
911: u_int32_t out_blocks;
912:
913: /* XXX client can't cope with rekeying pre-auth */
914: if (!state->after_authentication)
915: return 0;
916:
917: /* Haven't keyed yet or KEX in progress. */
918: if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
919: return 0;
920:
921: /* Peer can't rekey */
922: if (ssh->compat & SSH_BUG_NOREKEY)
923: return 0;
924:
925: /*
926: * Permit one packet in or out per rekey - this allows us to
927: * make progress when rekey limits are very small.
928: */
929: if (state->p_send.packets == 0 && state->p_read.packets == 0)
930: return 0;
931:
932: /* Time-based rekeying */
933: if (state->rekey_interval != 0 &&
1.244 dtucker 934: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 935: return 1;
936:
1.261 dtucker 937: /*
938: * Always rekey when MAX_PACKETS sent in either direction
939: * As per RFC4344 section 3.1 we do this after 2^31 packets.
940: */
1.228 djm 941: if (state->p_send.packets > MAX_PACKETS ||
942: state->p_read.packets > MAX_PACKETS)
943: return 1;
944:
945: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 946: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 947: state->newkeys[MODE_OUT]->enc.block_size);
948: return (state->max_blocks_out &&
949: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
950: (state->max_blocks_in &&
951: (state->p_read.blocks > state->max_blocks_in));
952: }
953:
1.16 markus 954: /*
1.118 markus 955: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 956: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 957: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
958: */
1.201 markus 959: static int
960: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 961: {
1.201 markus 962: struct session_state *state = ssh->state;
963: struct sshcomp *comp = NULL;
964: int r, mode;
1.118 markus 965:
966: /*
967: * Remember that we are past the authentication step, so rekeying
968: * with COMP_DELAYED will turn on compression immediately.
969: */
1.201 markus 970: state->after_authentication = 1;
1.118 markus 971: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 972: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 973: if (state->newkeys[mode] == NULL)
1.145 markus 974: continue;
1.201 markus 975: comp = &state->newkeys[mode]->comp;
1.118 markus 976: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 977: if ((r = ssh_packet_init_compression(ssh)) != 0)
978: return r;
979: if (mode == MODE_OUT) {
980: if ((r = start_compression_out(ssh, 6)) != 0)
981: return r;
982: } else {
983: if ((r = start_compression_in(ssh)) != 0)
984: return r;
985: }
1.118 markus 986: comp->enabled = 1;
987: }
988: }
1.201 markus 989: return 0;
1.118 markus 990: }
991:
1.226 djm 992: /* Used to mute debug logging for noisy packet types */
1.242 markus 993: int
1.226 djm 994: ssh_packet_log_type(u_char type)
995: {
996: switch (type) {
997: case SSH2_MSG_CHANNEL_DATA:
998: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
999: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1000: return 0;
1001: default:
1002: return 1;
1003: }
1004: }
1005:
1.118 markus 1006: /*
1.25 markus 1007: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1008: */
1.201 markus 1009: int
1010: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1011: {
1.201 markus 1012: struct session_state *state = ssh->state;
1.200 markus 1013: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1014: u_char tmp, padlen, pad = 0;
1.201 markus 1015: u_int authlen = 0, aadlen = 0;
1016: u_int len;
1017: struct sshenc *enc = NULL;
1018: struct sshmac *mac = NULL;
1019: struct sshcomp *comp = NULL;
1020: int r, block_size;
1021:
1022: if (state->newkeys[MODE_OUT] != NULL) {
1023: enc = &state->newkeys[MODE_OUT]->enc;
1024: mac = &state->newkeys[MODE_OUT]->mac;
1025: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1026: /* disable mac for authenticated encryption */
1027: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1028: mac = NULL;
1.25 markus 1029: }
1.88 markus 1030: block_size = enc ? enc->block_size : 8;
1.180 markus 1031: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1032:
1.201 markus 1033: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1034: if (ssh_packet_log_type(type))
1035: debug3("send packet: type %u", type);
1.25 markus 1036: #ifdef PACKET_DEBUG
1037: fprintf(stderr, "plain: ");
1.201 markus 1038: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1039: #endif
1040:
1041: if (comp && comp->enabled) {
1.201 markus 1042: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1043: /* skip header, compress only payload */
1.201 markus 1044: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1045: goto out;
1046: sshbuf_reset(state->compression_buffer);
1047: if ((r = compress_buffer(ssh, state->outgoing_packet,
1048: state->compression_buffer)) != 0)
1049: goto out;
1050: sshbuf_reset(state->outgoing_packet);
1051: if ((r = sshbuf_put(state->outgoing_packet,
1052: "\0\0\0\0\0", 5)) != 0 ||
1053: (r = sshbuf_putb(state->outgoing_packet,
1054: state->compression_buffer)) != 0)
1055: goto out;
1056: DBG(debug("compression: raw %d compressed %zd", len,
1057: sshbuf_len(state->outgoing_packet)));
1.25 markus 1058: }
1059:
1060: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1061: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1062:
1063: /*
1064: * calc size of padding, alloc space, get random data,
1065: * minimum padding is 4 bytes
1066: */
1.178 markus 1067: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1068: padlen = block_size - (len % block_size);
1069: if (padlen < 4)
1070: padlen += block_size;
1.201 markus 1071: if (state->extra_pad) {
1.233 djm 1072: tmp = state->extra_pad;
1.201 markus 1073: state->extra_pad =
1.237 deraadt 1074: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1075: /* check if roundup overflowed */
1076: if (state->extra_pad < tmp)
1077: return SSH_ERR_INVALID_ARGUMENT;
1078: tmp = (len + padlen) % state->extra_pad;
1079: /* Check whether pad calculation below will underflow */
1080: if (tmp > state->extra_pad)
1081: return SSH_ERR_INVALID_ARGUMENT;
1082: pad = state->extra_pad - tmp;
1.193 djm 1083: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1084: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1085: tmp = padlen;
1.71 markus 1086: padlen += pad;
1.233 djm 1087: /* Check whether padlen calculation overflowed */
1088: if (padlen < tmp)
1089: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1090: state->extra_pad = 0;
1.71 markus 1091: }
1.201 markus 1092: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1093: goto out;
1.235 djm 1094: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1095: /* random padding */
1.201 markus 1096: arc4random_buf(cp, padlen);
1.32 markus 1097: } else {
1098: /* clear padding */
1.192 djm 1099: explicit_bzero(cp, padlen);
1.25 markus 1100: }
1.178 markus 1101: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1102: len = sshbuf_len(state->outgoing_packet);
1103: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1104: if (cp == NULL) {
1105: r = SSH_ERR_INTERNAL_ERROR;
1106: goto out;
1107: }
1.25 markus 1108: /* packet_length includes payload, padding and padding length field */
1.201 markus 1109: POKE_U32(cp, len - 4);
1.89 markus 1110: cp[4] = padlen;
1.178 markus 1111: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1112: len, padlen, aadlen));
1.25 markus 1113:
1114: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1115: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1116: if ((r = mac_compute(mac, state->p_send.seqnr,
1117: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1118: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1119: goto out;
1120: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1121: }
1122: /* encrypt packet and append to output buffer. */
1.201 markus 1123: if ((r = sshbuf_reserve(state->output,
1124: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1125: goto out;
1.235 djm 1126: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1127: sshbuf_ptr(state->outgoing_packet),
1128: len - aadlen, aadlen, authlen)) != 0)
1129: goto out;
1.25 markus 1130: /* append unencrypted MAC */
1.178 markus 1131: if (mac && mac->enabled) {
1132: if (mac->etm) {
1133: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1134: if ((r = mac_compute(mac, state->p_send.seqnr,
1135: cp, len, macbuf, sizeof(macbuf))) != 0)
1136: goto out;
1.178 markus 1137: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1138: state->p_send.seqnr));
1.178 markus 1139: }
1.201 markus 1140: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1141: goto out;
1.178 markus 1142: }
1.25 markus 1143: #ifdef PACKET_DEBUG
1144: fprintf(stderr, "encrypted: ");
1.201 markus 1145: sshbuf_dump(state->output, stderr);
1.25 markus 1146: #endif
1.29 markus 1147: /* increment sequence number for outgoing packets */
1.201 markus 1148: if (++state->p_send.seqnr == 0)
1.106 itojun 1149: logit("outgoing seqnr wraps around");
1.201 markus 1150: if (++state->p_send.packets == 0)
1151: if (!(ssh->compat & SSH_BUG_NOREKEY))
1152: return SSH_ERR_NEED_REKEY;
1153: state->p_send.blocks += len / block_size;
1154: state->p_send.bytes += len;
1155: sshbuf_reset(state->outgoing_packet);
1.25 markus 1156:
1.57 markus 1157: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1158: r = ssh_set_newkeys(ssh, MODE_OUT);
1159: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1160: r = ssh_packet_enable_delayed_compress(ssh);
1161: else
1162: r = 0;
1163: out:
1164: return r;
1.25 markus 1165: }
1166:
1.228 djm 1167: /* returns non-zero if the specified packet type is usec by KEX */
1168: static int
1169: ssh_packet_type_is_kex(u_char type)
1170: {
1171: return
1172: type >= SSH2_MSG_TRANSPORT_MIN &&
1173: type <= SSH2_MSG_TRANSPORT_MAX &&
1174: type != SSH2_MSG_SERVICE_REQUEST &&
1175: type != SSH2_MSG_SERVICE_ACCEPT &&
1176: type != SSH2_MSG_EXT_INFO;
1177: }
1178:
1.201 markus 1179: int
1180: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1181: {
1.201 markus 1182: struct session_state *state = ssh->state;
1.105 markus 1183: struct packet *p;
1.201 markus 1184: u_char type;
1.228 djm 1185: int r, need_rekey;
1.105 markus 1186:
1.228 djm 1187: if (sshbuf_len(state->outgoing_packet) < 6)
1188: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1189: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1190: need_rekey = !ssh_packet_type_is_kex(type) &&
1191: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1192:
1.228 djm 1193: /*
1194: * During rekeying we can only send key exchange messages.
1195: * Queue everything else.
1196: */
1197: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1198: if (need_rekey)
1199: debug3("%s: rekex triggered", __func__);
1200: debug("enqueue packet: %u", type);
1201: p = calloc(1, sizeof(*p));
1202: if (p == NULL)
1203: return SSH_ERR_ALLOC_FAIL;
1204: p->type = type;
1205: p->payload = state->outgoing_packet;
1206: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1207: state->outgoing_packet = sshbuf_new();
1208: if (state->outgoing_packet == NULL)
1209: return SSH_ERR_ALLOC_FAIL;
1210: if (need_rekey) {
1211: /*
1212: * This packet triggered a rekey, so send the
1213: * KEXINIT now.
1214: * NB. reenters this function via kex_start_rekex().
1215: */
1216: return kex_start_rekex(ssh);
1.105 markus 1217: }
1.228 djm 1218: return 0;
1.105 markus 1219: }
1220:
1221: /* rekeying starts with sending KEXINIT */
1222: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1223: state->rekeying = 1;
1.105 markus 1224:
1.201 markus 1225: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1226: return r;
1.105 markus 1227:
1228: /* after a NEWKEYS message we can send the complete queue */
1229: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1230: state->rekeying = 0;
1231: state->rekey_time = monotime();
1232: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1233: type = p->type;
1.228 djm 1234: /*
1235: * If this packet triggers a rekex, then skip the
1236: * remaining packets in the queue for now.
1237: * NB. re-enters this function via kex_start_rekex.
1238: */
1239: if (ssh_packet_need_rekeying(ssh,
1240: sshbuf_len(p->payload))) {
1241: debug3("%s: queued packet triggered rekex",
1242: __func__);
1243: return kex_start_rekex(ssh);
1244: }
1.105 markus 1245: debug("dequeue packet: %u", type);
1.201 markus 1246: sshbuf_free(state->outgoing_packet);
1247: state->outgoing_packet = p->payload;
1248: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1249: memset(p, 0, sizeof(*p));
1.186 djm 1250: free(p);
1.201 markus 1251: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1252: return r;
1.105 markus 1253: }
1254: }
1.201 markus 1255: return 0;
1.25 markus 1256: }
1257:
1258: /*
1.16 markus 1259: * Waits until a packet has been received, and returns its type. Note that
1260: * no other data is processed until this returns, so this function should not
1261: * be used during the interactive session.
1262: */
1.1 deraadt 1263:
1.2 provos 1264: int
1.201 markus 1265: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1266: {
1.201 markus 1267: struct session_state *state = ssh->state;
1.222 markus 1268: int len, r, ms_remain;
1.56 millert 1269: fd_set *setp;
1.14 markus 1270: char buf[8192];
1.155 deraadt 1271: struct timeval timeout, start, *timeoutp = NULL;
1272:
1.25 markus 1273: DBG(debug("packet_read()"));
1.14 markus 1274:
1.214 deraadt 1275: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1276: NFDBITS), sizeof(fd_mask));
1.201 markus 1277: if (setp == NULL)
1278: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1279:
1.205 djm 1280: /*
1281: * Since we are blocking, ensure that all written packets have
1282: * been sent.
1283: */
1.210 markus 1284: if ((r = ssh_packet_write_wait(ssh)) != 0)
1285: goto out;
1.14 markus 1286:
1287: /* Stay in the loop until we have received a complete packet. */
1288: for (;;) {
1289: /* Try to read a packet from the buffer. */
1.201 markus 1290: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1291: if (r != 0)
1292: break;
1.14 markus 1293: /* If we got a packet, return it. */
1.201 markus 1294: if (*typep != SSH_MSG_NONE)
1295: break;
1.16 markus 1296: /*
1297: * Otherwise, wait for some data to arrive, add it to the
1298: * buffer, and try again.
1299: */
1.201 markus 1300: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1301: NFDBITS) * sizeof(fd_mask));
1.201 markus 1302: FD_SET(state->connection_in, setp);
1.16 markus 1303:
1.201 markus 1304: if (state->packet_timeout_ms > 0) {
1305: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1306: timeoutp = &timeout;
1307: }
1.14 markus 1308: /* Wait for some data to arrive. */
1.154 dtucker 1309: for (;;) {
1.201 markus 1310: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1311: ms_to_timeval(&timeout, ms_remain);
1312: gettimeofday(&start, NULL);
1313: }
1.201 markus 1314: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1315: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1316: break;
1.161 andreas 1317: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1318: break;
1.201 markus 1319: if (state->packet_timeout_ms == -1)
1.154 dtucker 1320: continue;
1321: ms_subtract_diff(&start, &ms_remain);
1322: if (ms_remain <= 0) {
1.201 markus 1323: r = 0;
1.154 dtucker 1324: break;
1325: }
1326: }
1.246 djm 1327: if (r == 0) {
1328: r = SSH_ERR_CONN_TIMEOUT;
1329: goto out;
1330: }
1.14 markus 1331: /* Read data from the socket. */
1.222 markus 1332: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1333: if (len == 0) {
1334: r = SSH_ERR_CONN_CLOSED;
1335: goto out;
1336: }
1337: if (len < 0) {
1338: r = SSH_ERR_SYSTEM_ERROR;
1339: goto out;
1340: }
1.204 djm 1341:
1.14 markus 1342: /* Append it to the buffer. */
1.204 djm 1343: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1344: goto out;
1.14 markus 1345: }
1.210 markus 1346: out:
1.201 markus 1347: free(setp);
1348: return r;
1.1 deraadt 1349: }
1350:
1.77 djm 1351: int
1.201 markus 1352: ssh_packet_read(struct ssh *ssh)
1.77 djm 1353: {
1.201 markus 1354: u_char type;
1355: int r;
1356:
1357: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1358: fatal("%s: %s", __func__, ssh_err(r));
1359: return type;
1.77 djm 1360: }
1361:
1.16 markus 1362: /*
1363: * Waits until a packet has been received, verifies that its type matches
1364: * that given, and gives a fatal error and exits if there is a mismatch.
1365: */
1.1 deraadt 1366:
1.205 djm 1367: int
1368: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1369: {
1.205 djm 1370: int r;
1371: u_char type;
1.1 deraadt 1372:
1.205 djm 1373: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1374: return r;
1375: if (type != expected_type) {
1376: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1377: "Protocol error: expected packet type %d, got %d",
1.205 djm 1378: expected_type, type)) != 0)
1379: return r;
1380: return SSH_ERR_PROTOCOL_ERROR;
1381: }
1382: return 0;
1.1 deraadt 1383: }
1.14 markus 1384:
1.242 markus 1385: static int
1386: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1387: {
1388: struct session_state *state = ssh->state;
1389: const u_char *cp;
1390: size_t need;
1391: int r;
1392:
1393: if (ssh->kex)
1394: return SSH_ERR_INTERNAL_ERROR;
1395: *typep = SSH_MSG_NONE;
1396: cp = sshbuf_ptr(state->input);
1397: if (state->packlen == 0) {
1398: if (sshbuf_len(state->input) < 4 + 1)
1399: return 0; /* packet is incomplete */
1400: state->packlen = PEEK_U32(cp);
1401: if (state->packlen < 4 + 1 ||
1402: state->packlen > PACKET_MAX_SIZE)
1403: return SSH_ERR_MESSAGE_INCOMPLETE;
1404: }
1405: need = state->packlen + 4;
1406: if (sshbuf_len(state->input) < need)
1407: return 0; /* packet is incomplete */
1408: sshbuf_reset(state->incoming_packet);
1409: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1410: state->packlen)) != 0 ||
1411: (r = sshbuf_consume(state->input, need)) != 0 ||
1412: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1413: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1414: return r;
1415: if (ssh_packet_log_type(*typep))
1416: debug3("%s: type %u", __func__, *typep);
1417: /* sshbuf_dump(state->incoming_packet, stderr); */
1418: /* reset for next packet */
1419: state->packlen = 0;
1420: return r;
1421: }
1422:
1.201 markus 1423: int
1424: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1425: {
1.201 markus 1426: struct session_state *state = ssh->state;
1.40 markus 1427: u_int padlen, need;
1.231 djm 1428: u_char *cp;
1.201 markus 1429: u_int maclen, aadlen = 0, authlen = 0, block_size;
1430: struct sshenc *enc = NULL;
1431: struct sshmac *mac = NULL;
1432: struct sshcomp *comp = NULL;
1.200 markus 1433: int r;
1.201 markus 1434:
1.242 markus 1435: if (state->mux)
1436: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1437:
1.201 markus 1438: *typep = SSH_MSG_NONE;
1439:
1440: if (state->packet_discard)
1441: return 0;
1442:
1443: if (state->newkeys[MODE_IN] != NULL) {
1444: enc = &state->newkeys[MODE_IN]->enc;
1445: mac = &state->newkeys[MODE_IN]->mac;
1446: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1447: /* disable mac for authenticated encryption */
1448: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1449: mac = NULL;
1.25 markus 1450: }
1451: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1452: block_size = enc ? enc->block_size : 8;
1.180 markus 1453: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1454:
1.201 markus 1455: if (aadlen && state->packlen == 0) {
1.235 djm 1456: if (cipher_get_length(state->receive_context,
1.201 markus 1457: &state->packlen, state->p_read.seqnr,
1458: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1459: return 0;
1460: if (state->packlen < 1 + 4 ||
1461: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1462: #ifdef PACKET_DEBUG
1.201 markus 1463: sshbuf_dump(state->input, stderr);
1.178 markus 1464: #endif
1.201 markus 1465: logit("Bad packet length %u.", state->packlen);
1466: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1467: return r;
1.217 djm 1468: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1469: }
1.201 markus 1470: sshbuf_reset(state->incoming_packet);
1471: } else if (state->packlen == 0) {
1.25 markus 1472: /*
1473: * check if input size is less than the cipher block size,
1474: * decrypt first block and extract length of incoming packet
1475: */
1.201 markus 1476: if (sshbuf_len(state->input) < block_size)
1477: return 0;
1478: sshbuf_reset(state->incoming_packet);
1479: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1480: &cp)) != 0)
1481: goto out;
1.235 djm 1482: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1483: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1484: block_size, 0, 0)) != 0)
1485: goto out;
1486: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1487: if (state->packlen < 1 + 4 ||
1488: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1489: #ifdef PACKET_DEBUG
1.201 markus 1490: fprintf(stderr, "input: \n");
1491: sshbuf_dump(state->input, stderr);
1492: fprintf(stderr, "incoming_packet: \n");
1493: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1494: #endif
1.201 markus 1495: logit("Bad packet length %u.", state->packlen);
1.234 markus 1496: return ssh_packet_start_discard(ssh, enc, mac, 0,
1497: PACKET_MAX_SIZE);
1.25 markus 1498: }
1.201 markus 1499: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1500: goto out;
1.25 markus 1501: }
1.201 markus 1502: DBG(debug("input: packet len %u", state->packlen+4));
1503:
1.178 markus 1504: if (aadlen) {
1505: /* only the payload is encrypted */
1.201 markus 1506: need = state->packlen;
1.178 markus 1507: } else {
1508: /*
1509: * the payload size and the payload are encrypted, but we
1510: * have a partial packet of block_size bytes
1511: */
1.201 markus 1512: need = 4 + state->packlen - block_size;
1.178 markus 1513: }
1.180 markus 1514: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1515: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1516: if (need % block_size != 0) {
1517: logit("padding error: need %d block %d mod %d",
1.25 markus 1518: need, block_size, need % block_size);
1.234 markus 1519: return ssh_packet_start_discard(ssh, enc, mac, 0,
1520: PACKET_MAX_SIZE - block_size);
1.158 markus 1521: }
1.25 markus 1522: /*
1523: * check if the entire packet has been received and
1.178 markus 1524: * decrypt into incoming_packet:
1525: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1526: * 'need' bytes are encrypted, followed by either
1527: * 'authlen' bytes of authentication tag or
1.178 markus 1528: * 'maclen' bytes of message authentication code.
1.25 markus 1529: */
1.201 markus 1530: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1531: return 0; /* packet is incomplete */
1.25 markus 1532: #ifdef PACKET_DEBUG
1533: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1534: sshbuf_dump(state->input, stderr);
1.25 markus 1535: #endif
1.231 djm 1536: /* EtM: check mac over encrypted input */
1.201 markus 1537: if (mac && mac->enabled && mac->etm) {
1.231 djm 1538: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1539: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1540: sshbuf_ptr(state->input) + aadlen + need + authlen,
1541: maclen)) != 0) {
1542: if (r == SSH_ERR_MAC_INVALID)
1543: logit("Corrupted MAC on input.");
1.201 markus 1544: goto out;
1.231 djm 1545: }
1.201 markus 1546: }
1547: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1548: &cp)) != 0)
1549: goto out;
1.235 djm 1550: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1551: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1552: goto out;
1553: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1554: goto out;
1.29 markus 1555: if (mac && mac->enabled) {
1.231 djm 1556: /* Not EtM: check MAC over cleartext */
1557: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1558: sshbuf_ptr(state->incoming_packet),
1559: sshbuf_len(state->incoming_packet),
1560: sshbuf_ptr(state->input), maclen)) != 0) {
1561: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1562: goto out;
1.159 markus 1563: logit("Corrupted MAC on input.");
1.247 markus 1564: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1565: return SSH_ERR_INTERNAL_ERROR;
1566: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1567: sshbuf_len(state->incoming_packet),
1.247 markus 1568: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1569: }
1.231 djm 1570: /* Remove MAC from input buffer */
1.201 markus 1571: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1572: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1573: goto out;
1.25 markus 1574: }
1.77 djm 1575: if (seqnr_p != NULL)
1.201 markus 1576: *seqnr_p = state->p_read.seqnr;
1577: if (++state->p_read.seqnr == 0)
1.106 itojun 1578: logit("incoming seqnr wraps around");
1.201 markus 1579: if (++state->p_read.packets == 0)
1580: if (!(ssh->compat & SSH_BUG_NOREKEY))
1581: return SSH_ERR_NEED_REKEY;
1582: state->p_read.blocks += (state->packlen + 4) / block_size;
1583: state->p_read.bytes += state->packlen + 4;
1.25 markus 1584:
1585: /* get padlen */
1.201 markus 1586: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1587: DBG(debug("input: padlen %d", padlen));
1.205 djm 1588: if (padlen < 4) {
1589: if ((r = sshpkt_disconnect(ssh,
1590: "Corrupted padlen %d on input.", padlen)) != 0 ||
1591: (r = ssh_packet_write_wait(ssh)) != 0)
1592: return r;
1593: return SSH_ERR_CONN_CORRUPT;
1594: }
1.25 markus 1595:
1596: /* skip packet size + padlen, discard padding */
1.201 markus 1597: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1598: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1599: goto out;
1.25 markus 1600:
1.201 markus 1601: DBG(debug("input: len before de-compress %zd",
1602: sshbuf_len(state->incoming_packet)));
1.25 markus 1603: if (comp && comp->enabled) {
1.201 markus 1604: sshbuf_reset(state->compression_buffer);
1605: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1606: state->compression_buffer)) != 0)
1607: goto out;
1608: sshbuf_reset(state->incoming_packet);
1609: if ((r = sshbuf_putb(state->incoming_packet,
1610: state->compression_buffer)) != 0)
1611: goto out;
1612: DBG(debug("input: len after de-compress %zd",
1613: sshbuf_len(state->incoming_packet)));
1.25 markus 1614: }
1615: /*
1616: * get packet type, implies consume.
1617: * return length of payload (without type field)
1618: */
1.201 markus 1619: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1620: goto out;
1.226 djm 1621: if (ssh_packet_log_type(*typep))
1622: debug3("receive packet: type %u", *typep);
1.205 djm 1623: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1624: if ((r = sshpkt_disconnect(ssh,
1625: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1626: (r = ssh_packet_write_wait(ssh)) != 0)
1627: return r;
1628: return SSH_ERR_PROTOCOL_ERROR;
1629: }
1.243 djm 1630: if (state->hook_in != NULL &&
1631: (r = state->hook_in(ssh, state->incoming_packet, typep,
1632: state->hook_in_ctx)) != 0)
1633: return r;
1.238 markus 1634: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1635: r = ssh_packet_enable_delayed_compress(ssh);
1636: else
1637: r = 0;
1.25 markus 1638: #ifdef PACKET_DEBUG
1.201 markus 1639: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1640: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1641: #endif
1.62 markus 1642: /* reset for next packet */
1.201 markus 1643: state->packlen = 0;
1.228 djm 1644:
1645: /* do we need to rekey? */
1646: if (ssh_packet_need_rekeying(ssh, 0)) {
1647: debug3("%s: rekex triggered", __func__);
1648: if ((r = kex_start_rekex(ssh)) != 0)
1649: return r;
1650: }
1.201 markus 1651: out:
1652: return r;
1.25 markus 1653: }
1654:
1655: int
1.201 markus 1656: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1657: {
1.201 markus 1658: struct session_state *state = ssh->state;
1.96 deraadt 1659: u_int reason, seqnr;
1.201 markus 1660: int r;
1661: u_char *msg;
1.62 markus 1662:
1.25 markus 1663: for (;;) {
1.201 markus 1664: msg = NULL;
1.249 djm 1665: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1666: if (r != 0)
1667: return r;
1668: if (*typep) {
1669: state->keep_alive_timeouts = 0;
1670: DBG(debug("received packet type %d", *typep));
1671: }
1672: switch (*typep) {
1673: case SSH2_MSG_IGNORE:
1674: debug3("Received SSH2_MSG_IGNORE");
1675: break;
1676: case SSH2_MSG_DEBUG:
1677: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1678: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1679: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1680: free(msg);
1.201 markus 1681: return r;
1.48 stevesk 1682: }
1.249 djm 1683: debug("Remote: %.900s", msg);
1684: free(msg);
1685: break;
1686: case SSH2_MSG_DISCONNECT:
1687: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1688: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1689: return r;
1690: /* Ignore normal client exit notifications */
1691: do_log2(ssh->state->server_side &&
1692: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1693: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1694: "Received disconnect from %s port %d:"
1695: "%u: %.400s", ssh_remote_ipaddr(ssh),
1696: ssh_remote_port(ssh), reason, msg);
1697: free(msg);
1698: return SSH_ERR_DISCONNECTED;
1699: case SSH2_MSG_UNIMPLEMENTED:
1700: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1701: return r;
1702: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1703: seqnr);
1704: break;
1705: default:
1706: return 0;
1.25 markus 1707: }
1708: }
1709: }
1710:
1.16 markus 1711: /*
1712: * Buffers the given amount of input characters. This is intended to be used
1713: * together with packet_read_poll.
1714: */
1.1 deraadt 1715:
1.204 djm 1716: int
1.201 markus 1717: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1718: {
1.201 markus 1719: struct session_state *state = ssh->state;
1720: int r;
1721:
1722: if (state->packet_discard) {
1723: state->keep_alive_timeouts = 0; /* ?? */
1724: if (len >= state->packet_discard) {
1725: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1726: return r;
1.201 markus 1727: }
1728: state->packet_discard -= len;
1.204 djm 1729: return 0;
1.159 markus 1730: }
1.201 markus 1731: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1732: return r;
1733:
1734: return 0;
1.28 markus 1735: }
1736:
1737: int
1.201 markus 1738: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1739: {
1.201 markus 1740: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1741: }
1742:
1.16 markus 1743: /*
1744: * Sends a diagnostic message from the server to the client. This message
1745: * can be sent at any time (but not while constructing another message). The
1746: * message is printed immediately, but only if the client is being executed
1747: * in verbose mode. These messages are primarily intended to ease debugging
1748: * authentication problems. The length of the formatted message must not
1.205 djm 1749: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1750: */
1.2 provos 1751: void
1.201 markus 1752: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1753: {
1.14 markus 1754: char buf[1024];
1755: va_list args;
1.201 markus 1756: int r;
1.39 markus 1757:
1.249 djm 1758: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1759: return;
1.14 markus 1760:
1761: va_start(args, fmt);
1762: vsnprintf(buf, sizeof(buf), fmt, args);
1763: va_end(args);
1.265 ! djm 1764:
! 1765: debug3("sending debug message: %s", buf);
1.14 markus 1766:
1.249 djm 1767: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1768: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1769: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1770: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1771: (r = sshpkt_send(ssh)) != 0 ||
1772: (r = ssh_packet_write_wait(ssh)) != 0)
1.205 djm 1773: fatal("%s: %s", __func__, ssh_err(r));
1774: }
1775:
1.245 djm 1776: static void
1777: fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1778: {
1779: snprintf(s, l, "%.200s%s%s port %d",
1780: ssh->log_preamble ? ssh->log_preamble : "",
1781: ssh->log_preamble ? " " : "",
1782: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1783: }
1784:
1.205 djm 1785: /*
1786: * Pretty-print connection-terminating errors and exit.
1787: */
1788: void
1789: sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
1790: {
1.245 djm 1791: char remote_id[512];
1792:
1793: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1794:
1.205 djm 1795: switch (r) {
1796: case SSH_ERR_CONN_CLOSED:
1.257 markus 1797: ssh_packet_clear_keys(ssh);
1.245 djm 1798: logdie("Connection closed by %s", remote_id);
1.205 djm 1799: case SSH_ERR_CONN_TIMEOUT:
1.257 markus 1800: ssh_packet_clear_keys(ssh);
1.245 djm 1801: logdie("Connection %s %s timed out",
1802: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1803: case SSH_ERR_DISCONNECTED:
1.257 markus 1804: ssh_packet_clear_keys(ssh);
1.245 djm 1805: logdie("Disconnected from %s", remote_id);
1.212 djm 1806: case SSH_ERR_SYSTEM_ERROR:
1.257 markus 1807: if (errno == ECONNRESET) {
1808: ssh_packet_clear_keys(ssh);
1.245 djm 1809: logdie("Connection reset by %s", remote_id);
1.257 markus 1810: }
1.213 djm 1811: /* FALLTHROUGH */
1812: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1813: case SSH_ERR_NO_MAC_ALG_MATCH:
1814: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1815: case SSH_ERR_NO_KEX_ALG_MATCH:
1816: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1817: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.257 markus 1818: ssh_packet_clear_keys(ssh);
1.245 djm 1819: logdie("Unable to negotiate with %s: %s. "
1820: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1821: ssh->kex->failed_choice);
1.212 djm 1822: }
1823: /* FALLTHROUGH */
1.205 djm 1824: default:
1.257 markus 1825: ssh_packet_clear_keys(ssh);
1.245 djm 1826: logdie("%s%sConnection %s %s: %s",
1.205 djm 1827: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 1828: ssh->state->server_side ? "from" : "to",
1.245 djm 1829: remote_id, ssh_err(r));
1.205 djm 1830: }
1.1 deraadt 1831: }
1832:
1.16 markus 1833: /*
1834: * Logs the error plus constructs and sends a disconnect packet, closes the
1835: * connection, and exits. This function never returns. The error message
1836: * should not contain a newline. The length of the formatted message must
1837: * not exceed 1024 bytes.
1838: */
1.2 provos 1839: void
1.201 markus 1840: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1841: {
1.245 djm 1842: char buf[1024], remote_id[512];
1.14 markus 1843: va_list args;
1844: static int disconnecting = 0;
1.201 markus 1845: int r;
1.97 deraadt 1846:
1.14 markus 1847: if (disconnecting) /* Guard against recursive invocations. */
1848: fatal("packet_disconnect called recursively.");
1849: disconnecting = 1;
1850:
1.16 markus 1851: /*
1852: * Format the message. Note that the caller must make sure the
1853: * message is of limited size.
1854: */
1.245 djm 1855: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1856: va_start(args, fmt);
1857: vsnprintf(buf, sizeof(buf), fmt, args);
1858: va_end(args);
1859:
1.99 markus 1860: /* Display the error locally */
1.245 djm 1861: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1862:
1.205 djm 1863: /*
1864: * Send the disconnect message to the other side, and wait
1865: * for it to get sent.
1866: */
1867: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1868: sshpkt_fatal(ssh, __func__, r);
1869:
1870: if ((r = ssh_packet_write_wait(ssh)) != 0)
1871: sshpkt_fatal(ssh, __func__, r);
1.14 markus 1872:
1873: /* Close the connection. */
1.201 markus 1874: ssh_packet_close(ssh);
1.112 markus 1875: cleanup_exit(255);
1.1 deraadt 1876: }
1877:
1.205 djm 1878: /*
1879: * Checks if there is any buffered output, and tries to write some of
1880: * the output.
1881: */
1882: int
1.201 markus 1883: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1884: {
1.201 markus 1885: struct session_state *state = ssh->state;
1886: int len = sshbuf_len(state->output);
1.222 markus 1887: int r;
1.97 deraadt 1888:
1.14 markus 1889: if (len > 0) {
1.222 markus 1890: len = write(state->connection_out,
1891: sshbuf_ptr(state->output), len);
1.156 djm 1892: if (len == -1) {
1893: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1894: return 0;
1895: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1896: }
1.222 markus 1897: if (len == 0)
1.205 djm 1898: return SSH_ERR_CONN_CLOSED;
1.201 markus 1899: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1900: return r;
1.14 markus 1901: }
1.205 djm 1902: return 0;
1.1 deraadt 1903: }
1904:
1.16 markus 1905: /*
1906: * Calls packet_write_poll repeatedly until all pending output data has been
1907: * written.
1908: */
1.205 djm 1909: int
1.201 markus 1910: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1911: {
1.56 millert 1912: fd_set *setp;
1.205 djm 1913: int ret, r, ms_remain = 0;
1.154 dtucker 1914: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1915: struct session_state *state = ssh->state;
1.56 millert 1916:
1.214 deraadt 1917: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1918: NFDBITS), sizeof(fd_mask));
1.201 markus 1919: if (setp == NULL)
1.205 djm 1920: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1921: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1922: free(setp);
1.215 djm 1923: return r;
1.216 gsoares 1924: }
1.201 markus 1925: while (ssh_packet_have_data_to_write(ssh)) {
1926: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1927: NFDBITS) * sizeof(fd_mask));
1.201 markus 1928: FD_SET(state->connection_out, setp);
1.154 dtucker 1929:
1.201 markus 1930: if (state->packet_timeout_ms > 0) {
1931: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1932: timeoutp = &timeout;
1933: }
1934: for (;;) {
1.201 markus 1935: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1936: ms_to_timeval(&timeout, ms_remain);
1937: gettimeofday(&start, NULL);
1938: }
1.201 markus 1939: if ((ret = select(state->connection_out + 1,
1.161 andreas 1940: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1941: break;
1.161 andreas 1942: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1943: break;
1.201 markus 1944: if (state->packet_timeout_ms == -1)
1.154 dtucker 1945: continue;
1946: ms_subtract_diff(&start, &ms_remain);
1947: if (ms_remain <= 0) {
1948: ret = 0;
1949: break;
1950: }
1951: }
1952: if (ret == 0) {
1.205 djm 1953: free(setp);
1954: return SSH_ERR_CONN_TIMEOUT;
1955: }
1956: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1957: free(setp);
1958: return r;
1.154 dtucker 1959: }
1.14 markus 1960: }
1.186 djm 1961: free(setp);
1.205 djm 1962: return 0;
1.1 deraadt 1963: }
1964:
1965: /* Returns true if there is buffered data to write to the connection. */
1966:
1.2 provos 1967: int
1.201 markus 1968: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 1969: {
1.201 markus 1970: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 1971: }
1972:
1973: /* Returns true if there is not too much data to write to the connection. */
1974:
1.2 provos 1975: int
1.201 markus 1976: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 1977: {
1.201 markus 1978: if (ssh->state->interactive_mode)
1979: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 1980: else
1.201 markus 1981: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 1982: }
1983:
1.201 markus 1984: void
1985: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 1986: {
1.263 djm 1987: if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
1.101 markus 1988: return;
1.201 markus 1989: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 1990: case AF_INET:
1991: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 1992: if (setsockopt(ssh->state->connection_in,
1.173 djm 1993: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
1994: error("setsockopt IP_TOS %d: %.100s:",
1995: tos, strerror(errno));
1996: break;
1997: case AF_INET6:
1998: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 1999: if (setsockopt(ssh->state->connection_in,
1.173 djm 2000: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2001: error("setsockopt IPV6_TCLASS %d: %.100s:",
2002: tos, strerror(errno));
2003: break;
2004: }
1.101 markus 2005: }
2006:
1.1 deraadt 2007: /* Informs that the current session is interactive. Sets IP flags for that. */
2008:
1.2 provos 2009: void
1.201 markus 2010: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2011: {
1.201 markus 2012: struct session_state *state = ssh->state;
2013:
2014: if (state->set_interactive_called)
1.43 markus 2015: return;
1.201 markus 2016: state->set_interactive_called = 1;
1.1 deraadt 2017:
1.14 markus 2018: /* Record that we are in interactive mode. */
1.201 markus 2019: state->interactive_mode = interactive;
1.1 deraadt 2020:
1.19 markus 2021: /* Only set socket options if using a socket. */
1.201 markus 2022: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2023: return;
1.201 markus 2024: set_nodelay(state->connection_in);
2025: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2026: qos_bulk);
1.1 deraadt 2027: }
2028:
2029: /* Returns true if the current connection is interactive. */
2030:
1.2 provos 2031: int
1.201 markus 2032: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2033: {
1.201 markus 2034: return ssh->state->interactive_mode;
1.12 markus 2035: }
2036:
1.113 deraadt 2037: int
1.201 markus 2038: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2039: {
1.201 markus 2040: struct session_state *state = ssh->state;
2041:
2042: if (state->set_maxsize_called) {
1.106 itojun 2043: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2044: state->max_packet_size, s);
1.14 markus 2045: return -1;
2046: }
2047: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2048: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2049: return -1;
2050: }
1.201 markus 2051: state->set_maxsize_called = 1;
1.66 markus 2052: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2053: state->max_packet_size = s;
1.14 markus 2054: return s;
1.53 markus 2055: }
2056:
1.161 andreas 2057: int
1.201 markus 2058: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2059: {
1.201 markus 2060: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2061: }
2062:
2063: void
1.201 markus 2064: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2065: {
1.201 markus 2066: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2067: }
2068:
2069: u_int
1.201 markus 2070: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2071: {
1.201 markus 2072: return ssh->state->max_packet_size;
1.71 markus 2073: }
2074:
1.105 markus 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: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2179: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2180: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2181: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2182: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2183: goto out;
2184: if (cipher_authlen(enc->cipher) == 0) {
2185: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2186: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2187: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2188: goto out;
2189: }
2190: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2191: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2192: goto out;
2193: r = sshbuf_put_stringb(m, b);
2194: out:
1.221 mmcc 2195: sshbuf_free(b);
1.201 markus 2196: return r;
2197: }
2198:
2199: /* serialize packet state into a blob */
2200: int
2201: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2202: {
2203: struct session_state *state = ssh->state;
1.249 djm 2204: int r;
1.201 markus 2205:
1.249 djm 2206: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2207: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2208: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2209: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2210: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2211: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2212: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2213: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2214: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2215: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2216: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2217: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2218: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2219: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2220: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 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_u32(b, (u_int *)&enc->enabled)) != 0 ||
2253: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2254: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2255: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2256: goto out;
1.262 djm 2257: if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2258: r = SSH_ERR_INVALID_FORMAT;
2259: goto out;
2260: }
1.201 markus 2261: if (cipher_authlen(enc->cipher) == 0) {
2262: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2263: goto out;
2264: if ((r = mac_setup(mac, mac->name)) != 0)
2265: goto out;
2266: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2267: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2268: goto out;
2269: if (maclen > mac->key_len) {
2270: r = SSH_ERR_INVALID_FORMAT;
2271: goto out;
2272: }
2273: mac->key_len = maclen;
2274: }
2275: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2276: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2277: goto out;
2278: if (sshbuf_len(b) != 0) {
2279: r = SSH_ERR_INVALID_FORMAT;
2280: goto out;
2281: }
2282: enc->key_len = keylen;
2283: enc->iv_len = ivlen;
2284: ssh->kex->newkeys[mode] = newkey;
2285: newkey = NULL;
2286: r = 0;
2287: out:
1.219 mmcc 2288: free(newkey);
1.221 mmcc 2289: sshbuf_free(b);
1.201 markus 2290: return r;
2291: }
2292:
2293: /* restore kex from blob for packet state de-serialization */
2294: static int
2295: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2296: {
2297: struct kex *kex;
2298: int r;
2299:
2300: if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2301: (kex->my = sshbuf_new()) == NULL ||
2302: (kex->peer = sshbuf_new()) == NULL) {
2303: r = SSH_ERR_ALLOC_FAIL;
2304: goto out;
2305: }
2306: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2307: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2308: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2309: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2310: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2311: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2312: (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2313: (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2314: (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2315: goto out;
2316: kex->server = 1;
2317: kex->done = 1;
2318: r = 0;
2319: out:
2320: if (r != 0 || kexp == NULL) {
2321: if (kex != NULL) {
1.221 mmcc 2322: sshbuf_free(kex->my);
2323: sshbuf_free(kex->peer);
1.201 markus 2324: free(kex);
2325: }
2326: if (kexp != NULL)
2327: *kexp = NULL;
2328: } else {
2329: *kexp = kex;
2330: }
2331: return r;
2332: }
2333:
2334: /*
2335: * Restore packet state from content of blob 'm' (de-serialization).
2336: * Note that 'm' will be partially consumed on parsing or any other errors.
2337: */
2338: int
2339: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2340: {
2341: struct session_state *state = ssh->state;
1.254 djm 2342: const u_char *input, *output;
2343: size_t ilen, olen;
1.201 markus 2344: int r;
2345:
1.249 djm 2346: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2347: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2348: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2349: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2350: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2351: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2352: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2353: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2354: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2355: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2356: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2357: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2358: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2359: return r;
2360: /*
2361: * We set the time here so that in post-auth privsep slave we
2362: * count from the completion of the authentication.
2363: */
2364: state->rekey_time = monotime();
2365: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2366: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2367: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2368: return r;
1.201 markus 2369:
1.239 djm 2370: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2371: return r;
2372:
2373: sshbuf_reset(state->input);
2374: sshbuf_reset(state->output);
2375: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2376: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2377: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2378: (r = sshbuf_put(state->output, output, olen)) != 0)
2379: return r;
2380:
2381: if (sshbuf_len(m))
2382: return SSH_ERR_INVALID_FORMAT;
2383: debug3("%s: done", __func__);
2384: return 0;
2385: }
2386:
2387: /* NEW API */
2388:
2389: /* put data to the outgoing packet */
2390:
2391: int
2392: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2393: {
2394: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2395: }
2396:
2397: int
2398: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2399: {
2400: return sshbuf_putb(ssh->state->outgoing_packet, b);
2401: }
2402:
2403: int
2404: sshpkt_put_u8(struct ssh *ssh, u_char val)
2405: {
2406: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2407: }
2408:
2409: int
2410: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2411: {
2412: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2413: }
2414:
2415: int
2416: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2417: {
2418: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2419: }
2420:
2421: int
2422: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2423: {
2424: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2425: }
2426:
2427: int
2428: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2429: {
2430: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2431: }
2432:
2433: int
2434: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2435: {
2436: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2437: }
2438:
1.211 djm 2439: #ifdef WITH_OPENSSL
1.201 markus 2440: int
2441: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2442: {
2443: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2444: }
2445:
2446:
2447: int
2448: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2449: {
2450: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2451: }
1.211 djm 2452: #endif /* WITH_OPENSSL */
1.201 markus 2453:
2454: /* fetch data from the incoming packet */
2455:
2456: int
2457: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2458: {
2459: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2460: }
2461:
2462: int
2463: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2464: {
2465: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2466: }
2467:
2468: int
2469: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2470: {
2471: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2472: }
2473:
2474: int
2475: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2476: {
2477: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2478: }
2479:
2480: int
2481: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2482: {
2483: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2484: }
2485:
2486: int
2487: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2488: {
2489: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2490: }
2491:
2492: int
1.264 djm 2493: sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2494: {
2495: return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2496: }
2497:
2498: int
1.201 markus 2499: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2500: {
2501: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2502: }
2503:
1.211 djm 2504: #ifdef WITH_OPENSSL
1.201 markus 2505: int
2506: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2507: {
2508: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2509: }
2510:
2511:
2512: int
2513: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2514: {
2515: return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2516: }
1.211 djm 2517: #endif /* WITH_OPENSSL */
1.201 markus 2518:
2519: int
2520: sshpkt_get_end(struct ssh *ssh)
2521: {
2522: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2523: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2524: return 0;
2525: }
2526:
2527: const u_char *
2528: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2529: {
2530: if (lenp != NULL)
2531: *lenp = sshbuf_len(ssh->state->incoming_packet);
2532: return sshbuf_ptr(ssh->state->incoming_packet);
2533: }
2534:
2535: /* start a new packet */
2536:
2537: int
2538: sshpkt_start(struct ssh *ssh, u_char type)
2539: {
1.249 djm 2540: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2541:
2542: DBG(debug("packet_start[%d]", type));
1.249 djm 2543: memset(buf, 0, sizeof(buf));
2544: buf[sizeof(buf) - 1] = type;
1.201 markus 2545: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2546: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2547: }
2548:
1.242 markus 2549: static int
2550: ssh_packet_send_mux(struct ssh *ssh)
2551: {
2552: struct session_state *state = ssh->state;
2553: u_char type, *cp;
2554: size_t len;
2555: int r;
2556:
2557: if (ssh->kex)
2558: return SSH_ERR_INTERNAL_ERROR;
2559: len = sshbuf_len(state->outgoing_packet);
2560: if (len < 6)
2561: return SSH_ERR_INTERNAL_ERROR;
2562: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2563: type = cp[5];
2564: if (ssh_packet_log_type(type))
2565: debug3("%s: type %u", __func__, type);
2566: /* drop everything, but the connection protocol */
2567: if (type >= SSH2_MSG_CONNECTION_MIN &&
2568: type <= SSH2_MSG_CONNECTION_MAX) {
2569: POKE_U32(cp, len - 4);
2570: if ((r = sshbuf_putb(state->output,
2571: state->outgoing_packet)) != 0)
2572: return r;
2573: /* sshbuf_dump(state->output, stderr); */
2574: }
2575: sshbuf_reset(state->outgoing_packet);
1.264 djm 2576: return 0;
2577: }
2578:
2579: /*
2580: * 9.2. Ignored Data Message
2581: *
2582: * byte SSH_MSG_IGNORE
2583: * string data
2584: *
2585: * All implementations MUST understand (and ignore) this message at any
2586: * time (after receiving the protocol version). No implementation is
2587: * required to send them. This message can be used as an additional
2588: * protection measure against advanced traffic analysis techniques.
2589: */
2590: int
2591: sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2592: {
2593: u_int32_t rnd = 0;
2594: int r;
2595: u_int i;
2596:
2597: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2598: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2599: return r;
2600: for (i = 0; i < nbytes; i++) {
2601: if (i % 4 == 0)
2602: rnd = arc4random();
2603: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2604: return r;
2605: rnd >>= 8;
2606: }
1.242 markus 2607: return 0;
2608: }
2609:
1.201 markus 2610: /* send it */
2611:
2612: int
2613: sshpkt_send(struct ssh *ssh)
2614: {
1.242 markus 2615: if (ssh->state && ssh->state->mux)
2616: return ssh_packet_send_mux(ssh);
1.249 djm 2617: return ssh_packet_send2(ssh);
1.201 markus 2618: }
2619:
2620: int
2621: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2622: {
2623: char buf[1024];
2624: va_list args;
2625: int r;
2626:
2627: va_start(args, fmt);
2628: vsnprintf(buf, sizeof(buf), fmt, args);
2629: va_end(args);
2630:
1.249 djm 2631: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2632: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2633: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2634: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2635: (r = sshpkt_send(ssh)) != 0)
2636: return r;
1.201 markus 2637: return 0;
2638: }
2639:
2640: /* roundup current message to pad bytes */
2641: int
2642: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2643: {
2644: ssh->state->extra_pad = pad;
2645: return 0;
1.1 deraadt 2646: }
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