Annotation of src/usr.bin/ssh/packet.c, Revision 1.260
1.260 ! dtucker 1: /* $OpenBSD: packet.c,v 1.259 2017/06/01 06:16:43 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.
1.109 markus 893: */
894: if (enc->block_size >= 16)
895: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
896: else
897: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 898: if (state->rekey_limit)
1.237 deraadt 899: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 900: state->rekey_limit / enc->block_size);
1.227 djm 901: debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1.201 markus 902: return 0;
1.57 markus 903: }
904:
1.228 djm 905: #define MAX_PACKETS (1U<<31)
906: static int
907: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
908: {
909: struct session_state *state = ssh->state;
910: u_int32_t out_blocks;
911:
912: /* XXX client can't cope with rekeying pre-auth */
913: if (!state->after_authentication)
914: return 0;
915:
916: /* Haven't keyed yet or KEX in progress. */
917: if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
918: return 0;
919:
920: /* Peer can't rekey */
921: if (ssh->compat & SSH_BUG_NOREKEY)
922: return 0;
923:
924: /*
925: * Permit one packet in or out per rekey - this allows us to
926: * make progress when rekey limits are very small.
927: */
928: if (state->p_send.packets == 0 && state->p_read.packets == 0)
929: return 0;
930:
931: /* Time-based rekeying */
932: if (state->rekey_interval != 0 &&
1.244 dtucker 933: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 934: return 1;
935:
936: /* Always rekey when MAX_PACKETS sent in either direction */
937: if (state->p_send.packets > MAX_PACKETS ||
938: state->p_read.packets > MAX_PACKETS)
939: return 1;
940:
941: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 942: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 943: state->newkeys[MODE_OUT]->enc.block_size);
944: return (state->max_blocks_out &&
945: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
946: (state->max_blocks_in &&
947: (state->p_read.blocks > state->max_blocks_in));
948: }
949:
1.16 markus 950: /*
1.118 markus 951: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 952: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 953: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
954: */
1.201 markus 955: static int
956: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 957: {
1.201 markus 958: struct session_state *state = ssh->state;
959: struct sshcomp *comp = NULL;
960: int r, mode;
1.118 markus 961:
962: /*
963: * Remember that we are past the authentication step, so rekeying
964: * with COMP_DELAYED will turn on compression immediately.
965: */
1.201 markus 966: state->after_authentication = 1;
1.118 markus 967: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 968: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 969: if (state->newkeys[mode] == NULL)
1.145 markus 970: continue;
1.201 markus 971: comp = &state->newkeys[mode]->comp;
1.118 markus 972: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 973: if ((r = ssh_packet_init_compression(ssh)) != 0)
974: return r;
975: if (mode == MODE_OUT) {
976: if ((r = start_compression_out(ssh, 6)) != 0)
977: return r;
978: } else {
979: if ((r = start_compression_in(ssh)) != 0)
980: return r;
981: }
1.118 markus 982: comp->enabled = 1;
983: }
984: }
1.201 markus 985: return 0;
1.118 markus 986: }
987:
1.226 djm 988: /* Used to mute debug logging for noisy packet types */
1.242 markus 989: int
1.226 djm 990: ssh_packet_log_type(u_char type)
991: {
992: switch (type) {
993: case SSH2_MSG_CHANNEL_DATA:
994: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
995: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
996: return 0;
997: default:
998: return 1;
999: }
1000: }
1001:
1.118 markus 1002: /*
1.25 markus 1003: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1004: */
1.201 markus 1005: int
1006: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1007: {
1.201 markus 1008: struct session_state *state = ssh->state;
1.200 markus 1009: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1010: u_char tmp, padlen, pad = 0;
1.201 markus 1011: u_int authlen = 0, aadlen = 0;
1012: u_int len;
1013: struct sshenc *enc = NULL;
1014: struct sshmac *mac = NULL;
1015: struct sshcomp *comp = NULL;
1016: int r, block_size;
1017:
1018: if (state->newkeys[MODE_OUT] != NULL) {
1019: enc = &state->newkeys[MODE_OUT]->enc;
1020: mac = &state->newkeys[MODE_OUT]->mac;
1021: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1022: /* disable mac for authenticated encryption */
1023: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1024: mac = NULL;
1.25 markus 1025: }
1.88 markus 1026: block_size = enc ? enc->block_size : 8;
1.180 markus 1027: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1028:
1.201 markus 1029: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1030: if (ssh_packet_log_type(type))
1031: debug3("send packet: type %u", type);
1.25 markus 1032: #ifdef PACKET_DEBUG
1033: fprintf(stderr, "plain: ");
1.201 markus 1034: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1035: #endif
1036:
1037: if (comp && comp->enabled) {
1.201 markus 1038: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1039: /* skip header, compress only payload */
1.201 markus 1040: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1041: goto out;
1042: sshbuf_reset(state->compression_buffer);
1043: if ((r = compress_buffer(ssh, state->outgoing_packet,
1044: state->compression_buffer)) != 0)
1045: goto out;
1046: sshbuf_reset(state->outgoing_packet);
1047: if ((r = sshbuf_put(state->outgoing_packet,
1048: "\0\0\0\0\0", 5)) != 0 ||
1049: (r = sshbuf_putb(state->outgoing_packet,
1050: state->compression_buffer)) != 0)
1051: goto out;
1052: DBG(debug("compression: raw %d compressed %zd", len,
1053: sshbuf_len(state->outgoing_packet)));
1.25 markus 1054: }
1055:
1056: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1057: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1058:
1059: /*
1060: * calc size of padding, alloc space, get random data,
1061: * minimum padding is 4 bytes
1062: */
1.178 markus 1063: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1064: padlen = block_size - (len % block_size);
1065: if (padlen < 4)
1066: padlen += block_size;
1.201 markus 1067: if (state->extra_pad) {
1.233 djm 1068: tmp = state->extra_pad;
1.201 markus 1069: state->extra_pad =
1.237 deraadt 1070: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1071: /* check if roundup overflowed */
1072: if (state->extra_pad < tmp)
1073: return SSH_ERR_INVALID_ARGUMENT;
1074: tmp = (len + padlen) % state->extra_pad;
1075: /* Check whether pad calculation below will underflow */
1076: if (tmp > state->extra_pad)
1077: return SSH_ERR_INVALID_ARGUMENT;
1078: pad = state->extra_pad - tmp;
1.193 djm 1079: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1080: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1081: tmp = padlen;
1.71 markus 1082: padlen += pad;
1.233 djm 1083: /* Check whether padlen calculation overflowed */
1084: if (padlen < tmp)
1085: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1086: state->extra_pad = 0;
1.71 markus 1087: }
1.201 markus 1088: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1089: goto out;
1.235 djm 1090: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1091: /* random padding */
1.201 markus 1092: arc4random_buf(cp, padlen);
1.32 markus 1093: } else {
1094: /* clear padding */
1.192 djm 1095: explicit_bzero(cp, padlen);
1.25 markus 1096: }
1.178 markus 1097: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1098: len = sshbuf_len(state->outgoing_packet);
1099: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1100: if (cp == NULL) {
1101: r = SSH_ERR_INTERNAL_ERROR;
1102: goto out;
1103: }
1.25 markus 1104: /* packet_length includes payload, padding and padding length field */
1.201 markus 1105: POKE_U32(cp, len - 4);
1.89 markus 1106: cp[4] = padlen;
1.178 markus 1107: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1108: len, padlen, aadlen));
1.25 markus 1109:
1110: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1111: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1112: if ((r = mac_compute(mac, state->p_send.seqnr,
1113: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1114: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1115: goto out;
1116: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1117: }
1118: /* encrypt packet and append to output buffer. */
1.201 markus 1119: if ((r = sshbuf_reserve(state->output,
1120: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1121: goto out;
1.235 djm 1122: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1123: sshbuf_ptr(state->outgoing_packet),
1124: len - aadlen, aadlen, authlen)) != 0)
1125: goto out;
1.25 markus 1126: /* append unencrypted MAC */
1.178 markus 1127: if (mac && mac->enabled) {
1128: if (mac->etm) {
1129: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1130: if ((r = mac_compute(mac, state->p_send.seqnr,
1131: cp, len, macbuf, sizeof(macbuf))) != 0)
1132: goto out;
1.178 markus 1133: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1134: state->p_send.seqnr));
1.178 markus 1135: }
1.201 markus 1136: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1137: goto out;
1.178 markus 1138: }
1.25 markus 1139: #ifdef PACKET_DEBUG
1140: fprintf(stderr, "encrypted: ");
1.201 markus 1141: sshbuf_dump(state->output, stderr);
1.25 markus 1142: #endif
1.29 markus 1143: /* increment sequence number for outgoing packets */
1.201 markus 1144: if (++state->p_send.seqnr == 0)
1.106 itojun 1145: logit("outgoing seqnr wraps around");
1.201 markus 1146: if (++state->p_send.packets == 0)
1147: if (!(ssh->compat & SSH_BUG_NOREKEY))
1148: return SSH_ERR_NEED_REKEY;
1149: state->p_send.blocks += len / block_size;
1150: state->p_send.bytes += len;
1151: sshbuf_reset(state->outgoing_packet);
1.25 markus 1152:
1.57 markus 1153: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1154: r = ssh_set_newkeys(ssh, MODE_OUT);
1155: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1156: r = ssh_packet_enable_delayed_compress(ssh);
1157: else
1158: r = 0;
1159: out:
1160: return r;
1.25 markus 1161: }
1162:
1.228 djm 1163: /* returns non-zero if the specified packet type is usec by KEX */
1164: static int
1165: ssh_packet_type_is_kex(u_char type)
1166: {
1167: return
1168: type >= SSH2_MSG_TRANSPORT_MIN &&
1169: type <= SSH2_MSG_TRANSPORT_MAX &&
1170: type != SSH2_MSG_SERVICE_REQUEST &&
1171: type != SSH2_MSG_SERVICE_ACCEPT &&
1172: type != SSH2_MSG_EXT_INFO;
1173: }
1174:
1.201 markus 1175: int
1176: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1177: {
1.201 markus 1178: struct session_state *state = ssh->state;
1.105 markus 1179: struct packet *p;
1.201 markus 1180: u_char type;
1.228 djm 1181: int r, need_rekey;
1.105 markus 1182:
1.228 djm 1183: if (sshbuf_len(state->outgoing_packet) < 6)
1184: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1185: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1186: need_rekey = !ssh_packet_type_is_kex(type) &&
1187: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1188:
1.228 djm 1189: /*
1190: * During rekeying we can only send key exchange messages.
1191: * Queue everything else.
1192: */
1193: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1194: if (need_rekey)
1195: debug3("%s: rekex triggered", __func__);
1196: debug("enqueue packet: %u", type);
1197: p = calloc(1, sizeof(*p));
1198: if (p == NULL)
1199: return SSH_ERR_ALLOC_FAIL;
1200: p->type = type;
1201: p->payload = state->outgoing_packet;
1202: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1203: state->outgoing_packet = sshbuf_new();
1204: if (state->outgoing_packet == NULL)
1205: return SSH_ERR_ALLOC_FAIL;
1206: if (need_rekey) {
1207: /*
1208: * This packet triggered a rekey, so send the
1209: * KEXINIT now.
1210: * NB. reenters this function via kex_start_rekex().
1211: */
1212: return kex_start_rekex(ssh);
1.105 markus 1213: }
1.228 djm 1214: return 0;
1.105 markus 1215: }
1216:
1217: /* rekeying starts with sending KEXINIT */
1218: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1219: state->rekeying = 1;
1.105 markus 1220:
1.201 markus 1221: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1222: return r;
1.105 markus 1223:
1224: /* after a NEWKEYS message we can send the complete queue */
1225: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1226: state->rekeying = 0;
1227: state->rekey_time = monotime();
1228: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1229: type = p->type;
1.228 djm 1230: /*
1231: * If this packet triggers a rekex, then skip the
1232: * remaining packets in the queue for now.
1233: * NB. re-enters this function via kex_start_rekex.
1234: */
1235: if (ssh_packet_need_rekeying(ssh,
1236: sshbuf_len(p->payload))) {
1237: debug3("%s: queued packet triggered rekex",
1238: __func__);
1239: return kex_start_rekex(ssh);
1240: }
1.105 markus 1241: debug("dequeue packet: %u", type);
1.201 markus 1242: sshbuf_free(state->outgoing_packet);
1243: state->outgoing_packet = p->payload;
1244: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1245: memset(p, 0, sizeof(*p));
1.186 djm 1246: free(p);
1.201 markus 1247: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1248: return r;
1.105 markus 1249: }
1250: }
1.201 markus 1251: return 0;
1.25 markus 1252: }
1253:
1254: /*
1.16 markus 1255: * Waits until a packet has been received, and returns its type. Note that
1256: * no other data is processed until this returns, so this function should not
1257: * be used during the interactive session.
1258: */
1.1 deraadt 1259:
1.2 provos 1260: int
1.201 markus 1261: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1262: {
1.201 markus 1263: struct session_state *state = ssh->state;
1.222 markus 1264: int len, r, ms_remain;
1.56 millert 1265: fd_set *setp;
1.14 markus 1266: char buf[8192];
1.155 deraadt 1267: struct timeval timeout, start, *timeoutp = NULL;
1268:
1.25 markus 1269: DBG(debug("packet_read()"));
1.14 markus 1270:
1.214 deraadt 1271: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1272: NFDBITS), sizeof(fd_mask));
1.201 markus 1273: if (setp == NULL)
1274: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1275:
1.205 djm 1276: /*
1277: * Since we are blocking, ensure that all written packets have
1278: * been sent.
1279: */
1.210 markus 1280: if ((r = ssh_packet_write_wait(ssh)) != 0)
1281: goto out;
1.14 markus 1282:
1283: /* Stay in the loop until we have received a complete packet. */
1284: for (;;) {
1285: /* Try to read a packet from the buffer. */
1.201 markus 1286: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1287: if (r != 0)
1288: break;
1.14 markus 1289: /* If we got a packet, return it. */
1.201 markus 1290: if (*typep != SSH_MSG_NONE)
1291: break;
1.16 markus 1292: /*
1293: * Otherwise, wait for some data to arrive, add it to the
1294: * buffer, and try again.
1295: */
1.201 markus 1296: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1297: NFDBITS) * sizeof(fd_mask));
1.201 markus 1298: FD_SET(state->connection_in, setp);
1.16 markus 1299:
1.201 markus 1300: if (state->packet_timeout_ms > 0) {
1301: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1302: timeoutp = &timeout;
1303: }
1.14 markus 1304: /* Wait for some data to arrive. */
1.154 dtucker 1305: for (;;) {
1.201 markus 1306: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1307: ms_to_timeval(&timeout, ms_remain);
1308: gettimeofday(&start, NULL);
1309: }
1.201 markus 1310: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1311: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1312: break;
1.161 andreas 1313: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1314: break;
1.201 markus 1315: if (state->packet_timeout_ms == -1)
1.154 dtucker 1316: continue;
1317: ms_subtract_diff(&start, &ms_remain);
1318: if (ms_remain <= 0) {
1.201 markus 1319: r = 0;
1.154 dtucker 1320: break;
1321: }
1322: }
1.246 djm 1323: if (r == 0) {
1324: r = SSH_ERR_CONN_TIMEOUT;
1325: goto out;
1326: }
1.14 markus 1327: /* Read data from the socket. */
1.222 markus 1328: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1329: if (len == 0) {
1330: r = SSH_ERR_CONN_CLOSED;
1331: goto out;
1332: }
1333: if (len < 0) {
1334: r = SSH_ERR_SYSTEM_ERROR;
1335: goto out;
1336: }
1.204 djm 1337:
1.14 markus 1338: /* Append it to the buffer. */
1.204 djm 1339: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1340: goto out;
1.14 markus 1341: }
1.210 markus 1342: out:
1.201 markus 1343: free(setp);
1344: return r;
1.1 deraadt 1345: }
1346:
1.77 djm 1347: int
1.201 markus 1348: ssh_packet_read(struct ssh *ssh)
1.77 djm 1349: {
1.201 markus 1350: u_char type;
1351: int r;
1352:
1353: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1354: fatal("%s: %s", __func__, ssh_err(r));
1355: return type;
1.77 djm 1356: }
1357:
1.16 markus 1358: /*
1359: * Waits until a packet has been received, verifies that its type matches
1360: * that given, and gives a fatal error and exits if there is a mismatch.
1361: */
1.1 deraadt 1362:
1.205 djm 1363: int
1364: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1365: {
1.205 djm 1366: int r;
1367: u_char type;
1.1 deraadt 1368:
1.205 djm 1369: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1370: return r;
1371: if (type != expected_type) {
1372: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1373: "Protocol error: expected packet type %d, got %d",
1.205 djm 1374: expected_type, type)) != 0)
1375: return r;
1376: return SSH_ERR_PROTOCOL_ERROR;
1377: }
1378: return 0;
1.1 deraadt 1379: }
1.14 markus 1380:
1.242 markus 1381: static int
1382: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1383: {
1384: struct session_state *state = ssh->state;
1385: const u_char *cp;
1386: size_t need;
1387: int r;
1388:
1389: if (ssh->kex)
1390: return SSH_ERR_INTERNAL_ERROR;
1391: *typep = SSH_MSG_NONE;
1392: cp = sshbuf_ptr(state->input);
1393: if (state->packlen == 0) {
1394: if (sshbuf_len(state->input) < 4 + 1)
1395: return 0; /* packet is incomplete */
1396: state->packlen = PEEK_U32(cp);
1397: if (state->packlen < 4 + 1 ||
1398: state->packlen > PACKET_MAX_SIZE)
1399: return SSH_ERR_MESSAGE_INCOMPLETE;
1400: }
1401: need = state->packlen + 4;
1402: if (sshbuf_len(state->input) < need)
1403: return 0; /* packet is incomplete */
1404: sshbuf_reset(state->incoming_packet);
1405: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1406: state->packlen)) != 0 ||
1407: (r = sshbuf_consume(state->input, need)) != 0 ||
1408: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1409: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1410: return r;
1411: if (ssh_packet_log_type(*typep))
1412: debug3("%s: type %u", __func__, *typep);
1413: /* sshbuf_dump(state->incoming_packet, stderr); */
1414: /* reset for next packet */
1415: state->packlen = 0;
1416: return r;
1417: }
1418:
1.201 markus 1419: int
1420: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1421: {
1.201 markus 1422: struct session_state *state = ssh->state;
1.40 markus 1423: u_int padlen, need;
1.231 djm 1424: u_char *cp;
1.201 markus 1425: u_int maclen, aadlen = 0, authlen = 0, block_size;
1426: struct sshenc *enc = NULL;
1427: struct sshmac *mac = NULL;
1428: struct sshcomp *comp = NULL;
1.200 markus 1429: int r;
1.201 markus 1430:
1.242 markus 1431: if (state->mux)
1432: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1433:
1.201 markus 1434: *typep = SSH_MSG_NONE;
1435:
1436: if (state->packet_discard)
1437: return 0;
1438:
1439: if (state->newkeys[MODE_IN] != NULL) {
1440: enc = &state->newkeys[MODE_IN]->enc;
1441: mac = &state->newkeys[MODE_IN]->mac;
1442: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1443: /* disable mac for authenticated encryption */
1444: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1445: mac = NULL;
1.25 markus 1446: }
1447: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1448: block_size = enc ? enc->block_size : 8;
1.180 markus 1449: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1450:
1.201 markus 1451: if (aadlen && state->packlen == 0) {
1.235 djm 1452: if (cipher_get_length(state->receive_context,
1.201 markus 1453: &state->packlen, state->p_read.seqnr,
1454: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1455: return 0;
1456: if (state->packlen < 1 + 4 ||
1457: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1458: #ifdef PACKET_DEBUG
1.201 markus 1459: sshbuf_dump(state->input, stderr);
1.178 markus 1460: #endif
1.201 markus 1461: logit("Bad packet length %u.", state->packlen);
1462: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1463: return r;
1.217 djm 1464: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1465: }
1.201 markus 1466: sshbuf_reset(state->incoming_packet);
1467: } else if (state->packlen == 0) {
1.25 markus 1468: /*
1469: * check if input size is less than the cipher block size,
1470: * decrypt first block and extract length of incoming packet
1471: */
1.201 markus 1472: if (sshbuf_len(state->input) < block_size)
1473: return 0;
1474: sshbuf_reset(state->incoming_packet);
1475: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1476: &cp)) != 0)
1477: goto out;
1.235 djm 1478: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1479: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1480: block_size, 0, 0)) != 0)
1481: goto out;
1482: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1483: if (state->packlen < 1 + 4 ||
1484: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1485: #ifdef PACKET_DEBUG
1.201 markus 1486: fprintf(stderr, "input: \n");
1487: sshbuf_dump(state->input, stderr);
1488: fprintf(stderr, "incoming_packet: \n");
1489: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1490: #endif
1.201 markus 1491: logit("Bad packet length %u.", state->packlen);
1.234 markus 1492: return ssh_packet_start_discard(ssh, enc, mac, 0,
1493: PACKET_MAX_SIZE);
1.25 markus 1494: }
1.201 markus 1495: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1496: goto out;
1.25 markus 1497: }
1.201 markus 1498: DBG(debug("input: packet len %u", state->packlen+4));
1499:
1.178 markus 1500: if (aadlen) {
1501: /* only the payload is encrypted */
1.201 markus 1502: need = state->packlen;
1.178 markus 1503: } else {
1504: /*
1505: * the payload size and the payload are encrypted, but we
1506: * have a partial packet of block_size bytes
1507: */
1.201 markus 1508: need = 4 + state->packlen - block_size;
1.178 markus 1509: }
1.180 markus 1510: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1511: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1512: if (need % block_size != 0) {
1513: logit("padding error: need %d block %d mod %d",
1.25 markus 1514: need, block_size, need % block_size);
1.234 markus 1515: return ssh_packet_start_discard(ssh, enc, mac, 0,
1516: PACKET_MAX_SIZE - block_size);
1.158 markus 1517: }
1.25 markus 1518: /*
1519: * check if the entire packet has been received and
1.178 markus 1520: * decrypt into incoming_packet:
1521: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1522: * 'need' bytes are encrypted, followed by either
1523: * 'authlen' bytes of authentication tag or
1.178 markus 1524: * 'maclen' bytes of message authentication code.
1.25 markus 1525: */
1.201 markus 1526: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1527: return 0; /* packet is incomplete */
1.25 markus 1528: #ifdef PACKET_DEBUG
1529: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1530: sshbuf_dump(state->input, stderr);
1.25 markus 1531: #endif
1.231 djm 1532: /* EtM: check mac over encrypted input */
1.201 markus 1533: if (mac && mac->enabled && mac->etm) {
1.231 djm 1534: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1535: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1536: sshbuf_ptr(state->input) + aadlen + need + authlen,
1537: maclen)) != 0) {
1538: if (r == SSH_ERR_MAC_INVALID)
1539: logit("Corrupted MAC on input.");
1.201 markus 1540: goto out;
1.231 djm 1541: }
1.201 markus 1542: }
1543: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1544: &cp)) != 0)
1545: goto out;
1.235 djm 1546: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1547: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1548: goto out;
1549: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1550: goto out;
1.29 markus 1551: if (mac && mac->enabled) {
1.231 djm 1552: /* Not EtM: check MAC over cleartext */
1553: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1554: sshbuf_ptr(state->incoming_packet),
1555: sshbuf_len(state->incoming_packet),
1556: sshbuf_ptr(state->input), maclen)) != 0) {
1557: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1558: goto out;
1.159 markus 1559: logit("Corrupted MAC on input.");
1.247 markus 1560: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1561: return SSH_ERR_INTERNAL_ERROR;
1562: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1563: sshbuf_len(state->incoming_packet),
1.247 markus 1564: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1565: }
1.231 djm 1566: /* Remove MAC from input buffer */
1.201 markus 1567: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1568: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1569: goto out;
1.25 markus 1570: }
1.77 djm 1571: if (seqnr_p != NULL)
1.201 markus 1572: *seqnr_p = state->p_read.seqnr;
1573: if (++state->p_read.seqnr == 0)
1.106 itojun 1574: logit("incoming seqnr wraps around");
1.201 markus 1575: if (++state->p_read.packets == 0)
1576: if (!(ssh->compat & SSH_BUG_NOREKEY))
1577: return SSH_ERR_NEED_REKEY;
1578: state->p_read.blocks += (state->packlen + 4) / block_size;
1579: state->p_read.bytes += state->packlen + 4;
1.25 markus 1580:
1581: /* get padlen */
1.201 markus 1582: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1583: DBG(debug("input: padlen %d", padlen));
1.205 djm 1584: if (padlen < 4) {
1585: if ((r = sshpkt_disconnect(ssh,
1586: "Corrupted padlen %d on input.", padlen)) != 0 ||
1587: (r = ssh_packet_write_wait(ssh)) != 0)
1588: return r;
1589: return SSH_ERR_CONN_CORRUPT;
1590: }
1.25 markus 1591:
1592: /* skip packet size + padlen, discard padding */
1.201 markus 1593: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1594: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1595: goto out;
1.25 markus 1596:
1.201 markus 1597: DBG(debug("input: len before de-compress %zd",
1598: sshbuf_len(state->incoming_packet)));
1.25 markus 1599: if (comp && comp->enabled) {
1.201 markus 1600: sshbuf_reset(state->compression_buffer);
1601: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1602: state->compression_buffer)) != 0)
1603: goto out;
1604: sshbuf_reset(state->incoming_packet);
1605: if ((r = sshbuf_putb(state->incoming_packet,
1606: state->compression_buffer)) != 0)
1607: goto out;
1608: DBG(debug("input: len after de-compress %zd",
1609: sshbuf_len(state->incoming_packet)));
1.25 markus 1610: }
1611: /*
1612: * get packet type, implies consume.
1613: * return length of payload (without type field)
1614: */
1.201 markus 1615: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1616: goto out;
1.226 djm 1617: if (ssh_packet_log_type(*typep))
1618: debug3("receive packet: type %u", *typep);
1.205 djm 1619: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1620: if ((r = sshpkt_disconnect(ssh,
1621: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1622: (r = ssh_packet_write_wait(ssh)) != 0)
1623: return r;
1624: return SSH_ERR_PROTOCOL_ERROR;
1625: }
1.243 djm 1626: if (state->hook_in != NULL &&
1627: (r = state->hook_in(ssh, state->incoming_packet, typep,
1628: state->hook_in_ctx)) != 0)
1629: return r;
1.238 markus 1630: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1631: r = ssh_packet_enable_delayed_compress(ssh);
1632: else
1633: r = 0;
1.25 markus 1634: #ifdef PACKET_DEBUG
1.201 markus 1635: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1636: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1637: #endif
1.62 markus 1638: /* reset for next packet */
1.201 markus 1639: state->packlen = 0;
1.228 djm 1640:
1641: /* do we need to rekey? */
1642: if (ssh_packet_need_rekeying(ssh, 0)) {
1643: debug3("%s: rekex triggered", __func__);
1644: if ((r = kex_start_rekex(ssh)) != 0)
1645: return r;
1646: }
1.201 markus 1647: out:
1648: return r;
1.25 markus 1649: }
1650:
1651: int
1.201 markus 1652: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1653: {
1.201 markus 1654: struct session_state *state = ssh->state;
1.96 deraadt 1655: u_int reason, seqnr;
1.201 markus 1656: int r;
1657: u_char *msg;
1.62 markus 1658:
1.25 markus 1659: for (;;) {
1.201 markus 1660: msg = NULL;
1.249 djm 1661: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1662: if (r != 0)
1663: return r;
1664: if (*typep) {
1665: state->keep_alive_timeouts = 0;
1666: DBG(debug("received packet type %d", *typep));
1667: }
1668: switch (*typep) {
1669: case SSH2_MSG_IGNORE:
1670: debug3("Received SSH2_MSG_IGNORE");
1671: break;
1672: case SSH2_MSG_DEBUG:
1673: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1674: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1675: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1676: free(msg);
1.201 markus 1677: return r;
1.48 stevesk 1678: }
1.249 djm 1679: debug("Remote: %.900s", msg);
1680: free(msg);
1681: break;
1682: case SSH2_MSG_DISCONNECT:
1683: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1684: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1685: return r;
1686: /* Ignore normal client exit notifications */
1687: do_log2(ssh->state->server_side &&
1688: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1689: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1690: "Received disconnect from %s port %d:"
1691: "%u: %.400s", ssh_remote_ipaddr(ssh),
1692: ssh_remote_port(ssh), reason, msg);
1693: free(msg);
1694: return SSH_ERR_DISCONNECTED;
1695: case SSH2_MSG_UNIMPLEMENTED:
1696: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1697: return r;
1698: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1699: seqnr);
1700: break;
1701: default:
1702: return 0;
1.25 markus 1703: }
1704: }
1705: }
1706:
1.16 markus 1707: /*
1708: * Buffers the given amount of input characters. This is intended to be used
1709: * together with packet_read_poll.
1710: */
1.1 deraadt 1711:
1.204 djm 1712: int
1.201 markus 1713: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1714: {
1.201 markus 1715: struct session_state *state = ssh->state;
1716: int r;
1717:
1718: if (state->packet_discard) {
1719: state->keep_alive_timeouts = 0; /* ?? */
1720: if (len >= state->packet_discard) {
1721: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1722: return r;
1.201 markus 1723: }
1724: state->packet_discard -= len;
1.204 djm 1725: return 0;
1.159 markus 1726: }
1.201 markus 1727: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1728: return r;
1729:
1730: return 0;
1.28 markus 1731: }
1732:
1733: int
1.201 markus 1734: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1735: {
1.201 markus 1736: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1737: }
1738:
1.16 markus 1739: /*
1740: * Sends a diagnostic message from the server to the client. This message
1741: * can be sent at any time (but not while constructing another message). The
1742: * message is printed immediately, but only if the client is being executed
1743: * in verbose mode. These messages are primarily intended to ease debugging
1744: * authentication problems. The length of the formatted message must not
1.205 djm 1745: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1746: */
1.2 provos 1747: void
1.201 markus 1748: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1749: {
1.14 markus 1750: char buf[1024];
1751: va_list args;
1.201 markus 1752: int r;
1.39 markus 1753:
1.249 djm 1754: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1755: return;
1.14 markus 1756:
1757: va_start(args, fmt);
1758: vsnprintf(buf, sizeof(buf), fmt, args);
1759: va_end(args);
1760:
1.249 djm 1761: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1762: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1763: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1764: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1765: (r = sshpkt_send(ssh)) != 0 ||
1766: (r = ssh_packet_write_wait(ssh)) != 0)
1.205 djm 1767: fatal("%s: %s", __func__, ssh_err(r));
1768: }
1769:
1.245 djm 1770: static void
1771: fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1772: {
1773: snprintf(s, l, "%.200s%s%s port %d",
1774: ssh->log_preamble ? ssh->log_preamble : "",
1775: ssh->log_preamble ? " " : "",
1776: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1777: }
1778:
1.205 djm 1779: /*
1780: * Pretty-print connection-terminating errors and exit.
1781: */
1782: void
1783: sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
1784: {
1.245 djm 1785: char remote_id[512];
1786:
1787: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1788:
1.205 djm 1789: switch (r) {
1790: case SSH_ERR_CONN_CLOSED:
1.257 markus 1791: ssh_packet_clear_keys(ssh);
1.245 djm 1792: logdie("Connection closed by %s", remote_id);
1.205 djm 1793: case SSH_ERR_CONN_TIMEOUT:
1.257 markus 1794: ssh_packet_clear_keys(ssh);
1.245 djm 1795: logdie("Connection %s %s timed out",
1796: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1797: case SSH_ERR_DISCONNECTED:
1.257 markus 1798: ssh_packet_clear_keys(ssh);
1.245 djm 1799: logdie("Disconnected from %s", remote_id);
1.212 djm 1800: case SSH_ERR_SYSTEM_ERROR:
1.257 markus 1801: if (errno == ECONNRESET) {
1802: ssh_packet_clear_keys(ssh);
1.245 djm 1803: logdie("Connection reset by %s", remote_id);
1.257 markus 1804: }
1.213 djm 1805: /* FALLTHROUGH */
1806: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1807: case SSH_ERR_NO_MAC_ALG_MATCH:
1808: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1809: case SSH_ERR_NO_KEX_ALG_MATCH:
1810: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1811: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.257 markus 1812: ssh_packet_clear_keys(ssh);
1.245 djm 1813: logdie("Unable to negotiate with %s: %s. "
1814: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1815: ssh->kex->failed_choice);
1.212 djm 1816: }
1817: /* FALLTHROUGH */
1.205 djm 1818: default:
1.257 markus 1819: ssh_packet_clear_keys(ssh);
1.245 djm 1820: logdie("%s%sConnection %s %s: %s",
1.205 djm 1821: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 1822: ssh->state->server_side ? "from" : "to",
1.245 djm 1823: remote_id, ssh_err(r));
1.205 djm 1824: }
1.1 deraadt 1825: }
1826:
1.16 markus 1827: /*
1828: * Logs the error plus constructs and sends a disconnect packet, closes the
1829: * connection, and exits. This function never returns. The error message
1830: * should not contain a newline. The length of the formatted message must
1831: * not exceed 1024 bytes.
1832: */
1.2 provos 1833: void
1.201 markus 1834: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1835: {
1.245 djm 1836: char buf[1024], remote_id[512];
1.14 markus 1837: va_list args;
1838: static int disconnecting = 0;
1.201 markus 1839: int r;
1.97 deraadt 1840:
1.14 markus 1841: if (disconnecting) /* Guard against recursive invocations. */
1842: fatal("packet_disconnect called recursively.");
1843: disconnecting = 1;
1844:
1.16 markus 1845: /*
1846: * Format the message. Note that the caller must make sure the
1847: * message is of limited size.
1848: */
1.245 djm 1849: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1850: va_start(args, fmt);
1851: vsnprintf(buf, sizeof(buf), fmt, args);
1852: va_end(args);
1853:
1.99 markus 1854: /* Display the error locally */
1.245 djm 1855: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1856:
1.205 djm 1857: /*
1858: * Send the disconnect message to the other side, and wait
1859: * for it to get sent.
1860: */
1861: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1862: sshpkt_fatal(ssh, __func__, r);
1863:
1864: if ((r = ssh_packet_write_wait(ssh)) != 0)
1865: sshpkt_fatal(ssh, __func__, r);
1.14 markus 1866:
1867: /* Close the connection. */
1.201 markus 1868: ssh_packet_close(ssh);
1.112 markus 1869: cleanup_exit(255);
1.1 deraadt 1870: }
1871:
1.205 djm 1872: /*
1873: * Checks if there is any buffered output, and tries to write some of
1874: * the output.
1875: */
1876: int
1.201 markus 1877: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1878: {
1.201 markus 1879: struct session_state *state = ssh->state;
1880: int len = sshbuf_len(state->output);
1.222 markus 1881: int r;
1.97 deraadt 1882:
1.14 markus 1883: if (len > 0) {
1.222 markus 1884: len = write(state->connection_out,
1885: sshbuf_ptr(state->output), len);
1.156 djm 1886: if (len == -1) {
1887: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1888: return 0;
1889: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1890: }
1.222 markus 1891: if (len == 0)
1.205 djm 1892: return SSH_ERR_CONN_CLOSED;
1.201 markus 1893: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1894: return r;
1.14 markus 1895: }
1.205 djm 1896: return 0;
1.1 deraadt 1897: }
1898:
1.16 markus 1899: /*
1900: * Calls packet_write_poll repeatedly until all pending output data has been
1901: * written.
1902: */
1.205 djm 1903: int
1.201 markus 1904: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1905: {
1.56 millert 1906: fd_set *setp;
1.205 djm 1907: int ret, r, ms_remain = 0;
1.154 dtucker 1908: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1909: struct session_state *state = ssh->state;
1.56 millert 1910:
1.214 deraadt 1911: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1912: NFDBITS), sizeof(fd_mask));
1.201 markus 1913: if (setp == NULL)
1.205 djm 1914: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1915: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1916: free(setp);
1.215 djm 1917: return r;
1.216 gsoares 1918: }
1.201 markus 1919: while (ssh_packet_have_data_to_write(ssh)) {
1920: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1921: NFDBITS) * sizeof(fd_mask));
1.201 markus 1922: FD_SET(state->connection_out, setp);
1.154 dtucker 1923:
1.201 markus 1924: if (state->packet_timeout_ms > 0) {
1925: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1926: timeoutp = &timeout;
1927: }
1928: for (;;) {
1.201 markus 1929: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1930: ms_to_timeval(&timeout, ms_remain);
1931: gettimeofday(&start, NULL);
1932: }
1.201 markus 1933: if ((ret = select(state->connection_out + 1,
1.161 andreas 1934: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1935: break;
1.161 andreas 1936: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1937: break;
1.201 markus 1938: if (state->packet_timeout_ms == -1)
1.154 dtucker 1939: continue;
1940: ms_subtract_diff(&start, &ms_remain);
1941: if (ms_remain <= 0) {
1942: ret = 0;
1943: break;
1944: }
1945: }
1946: if (ret == 0) {
1.205 djm 1947: free(setp);
1948: return SSH_ERR_CONN_TIMEOUT;
1949: }
1950: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1951: free(setp);
1952: return r;
1.154 dtucker 1953: }
1.14 markus 1954: }
1.186 djm 1955: free(setp);
1.205 djm 1956: return 0;
1.1 deraadt 1957: }
1958:
1959: /* Returns true if there is buffered data to write to the connection. */
1960:
1.2 provos 1961: int
1.201 markus 1962: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 1963: {
1.201 markus 1964: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 1965: }
1966:
1967: /* Returns true if there is not too much data to write to the connection. */
1968:
1.2 provos 1969: int
1.201 markus 1970: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 1971: {
1.201 markus 1972: if (ssh->state->interactive_mode)
1973: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 1974: else
1.201 markus 1975: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 1976: }
1977:
1.201 markus 1978: void
1979: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 1980: {
1.201 markus 1981: if (!ssh_packet_connection_is_on_socket(ssh))
1.101 markus 1982: return;
1.201 markus 1983: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 1984: case AF_INET:
1985: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 1986: if (setsockopt(ssh->state->connection_in,
1.173 djm 1987: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
1988: error("setsockopt IP_TOS %d: %.100s:",
1989: tos, strerror(errno));
1990: break;
1991: case AF_INET6:
1992: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 1993: if (setsockopt(ssh->state->connection_in,
1.173 djm 1994: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
1995: error("setsockopt IPV6_TCLASS %d: %.100s:",
1996: tos, strerror(errno));
1997: break;
1998: }
1.101 markus 1999: }
2000:
1.1 deraadt 2001: /* Informs that the current session is interactive. Sets IP flags for that. */
2002:
1.2 provos 2003: void
1.201 markus 2004: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2005: {
1.201 markus 2006: struct session_state *state = ssh->state;
2007:
2008: if (state->set_interactive_called)
1.43 markus 2009: return;
1.201 markus 2010: state->set_interactive_called = 1;
1.1 deraadt 2011:
1.14 markus 2012: /* Record that we are in interactive mode. */
1.201 markus 2013: state->interactive_mode = interactive;
1.1 deraadt 2014:
1.19 markus 2015: /* Only set socket options if using a socket. */
1.201 markus 2016: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2017: return;
1.201 markus 2018: set_nodelay(state->connection_in);
2019: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2020: qos_bulk);
1.1 deraadt 2021: }
2022:
2023: /* Returns true if the current connection is interactive. */
2024:
1.2 provos 2025: int
1.201 markus 2026: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2027: {
1.201 markus 2028: return ssh->state->interactive_mode;
1.12 markus 2029: }
2030:
1.113 deraadt 2031: int
1.201 markus 2032: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2033: {
1.201 markus 2034: struct session_state *state = ssh->state;
2035:
2036: if (state->set_maxsize_called) {
1.106 itojun 2037: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2038: state->max_packet_size, s);
1.14 markus 2039: return -1;
2040: }
2041: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2042: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2043: return -1;
2044: }
1.201 markus 2045: state->set_maxsize_called = 1;
1.66 markus 2046: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2047: state->max_packet_size = s;
1.14 markus 2048: return s;
1.53 markus 2049: }
2050:
1.161 andreas 2051: int
1.201 markus 2052: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2053: {
1.201 markus 2054: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2055: }
2056:
2057: void
1.201 markus 2058: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2059: {
1.201 markus 2060: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2061: }
2062:
2063: u_int
1.201 markus 2064: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2065: {
1.201 markus 2066: return ssh->state->max_packet_size;
1.71 markus 2067: }
2068:
1.53 markus 2069: /*
2070: * 9.2. Ignored Data Message
1.61 markus 2071: *
1.53 markus 2072: * byte SSH_MSG_IGNORE
2073: * string data
1.61 markus 2074: *
1.53 markus 2075: * All implementations MUST understand (and ignore) this message at any
2076: * time (after receiving the protocol version). No implementation is
2077: * required to send them. This message can be used as an additional
2078: * protection measure against advanced traffic analysis techniques.
2079: */
1.54 markus 2080: void
1.201 markus 2081: ssh_packet_send_ignore(struct ssh *ssh, int nbytes)
1.54 markus 2082: {
1.115 avsm 2083: u_int32_t rnd = 0;
1.201 markus 2084: int r, i;
1.54 markus 2085:
1.249 djm 2086: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
1.201 markus 2087: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2088: fatal("%s: %s", __func__, ssh_err(r));
1.75 deraadt 2089: for (i = 0; i < nbytes; i++) {
1.53 markus 2090: if (i % 4 == 0)
1.115 avsm 2091: rnd = arc4random();
1.201 markus 2092: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2093: fatal("%s: %s", __func__, ssh_err(r));
1.115 avsm 2094: rnd >>= 8;
1.53 markus 2095: }
1.105 markus 2096: }
2097:
2098: void
1.244 dtucker 2099: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2100: {
1.244 dtucker 2101: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2102: (unsigned int)seconds);
1.201 markus 2103: ssh->state->rekey_limit = bytes;
2104: ssh->state->rekey_interval = seconds;
1.184 dtucker 2105: }
2106:
2107: time_t
1.201 markus 2108: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2109: {
2110: time_t seconds;
2111:
1.201 markus 2112: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2113: monotime();
1.185 dtucker 2114: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2115: }
2116:
2117: void
1.201 markus 2118: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2119: {
1.201 markus 2120: ssh->state->server_side = 1;
1.118 markus 2121: }
2122:
2123: void
1.201 markus 2124: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2125: {
1.201 markus 2126: ssh->state->after_authentication = 1;
1.161 andreas 2127: }
2128:
2129: void *
1.201 markus 2130: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2131: {
1.201 markus 2132: return (void *)ssh->state->input;
1.161 andreas 2133: }
2134:
2135: void *
1.201 markus 2136: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2137: {
1.201 markus 2138: return (void *)ssh->state->output;
1.166 andreas 2139: }
2140:
1.196 markus 2141: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2142: static int
2143: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2144: {
1.239 djm 2145: int r;
1.196 markus 2146:
2147: debug("%s: called", __func__);
2148: /* This was set in net child, but is not visible in user child */
1.201 markus 2149: ssh->state->after_authentication = 1;
2150: ssh->state->rekeying = 0;
1.239 djm 2151: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2152: return r;
1.201 markus 2153: return 0;
2154: }
2155:
2156: /* Packet state (de-)serialization for privsep */
2157:
2158: /* turn kex into a blob for packet state serialization */
2159: static int
2160: kex_to_blob(struct sshbuf *m, struct kex *kex)
2161: {
2162: int r;
2163:
2164: if ((r = sshbuf_put_string(m, kex->session_id,
2165: kex->session_id_len)) != 0 ||
2166: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2167: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2168: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2169: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2170: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2171: (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2172: (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2173: (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2174: return r;
2175: return 0;
2176: }
2177:
2178: /* turn key exchange results into a blob for packet state serialization */
2179: static int
2180: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2181: {
2182: struct sshbuf *b;
2183: struct sshcipher_ctx *cc;
2184: struct sshcomp *comp;
2185: struct sshenc *enc;
2186: struct sshmac *mac;
2187: struct newkeys *newkey;
2188: int r;
2189:
2190: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2191: return SSH_ERR_INTERNAL_ERROR;
2192: enc = &newkey->enc;
2193: mac = &newkey->mac;
2194: comp = &newkey->comp;
1.235 djm 2195: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2196: ssh->state->receive_context;
1.201 markus 2197: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2198: return r;
2199: if ((b = sshbuf_new()) == NULL)
2200: return SSH_ERR_ALLOC_FAIL;
2201: /* The cipher struct is constant and shared, you export pointer */
2202: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2203: (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2204: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2205: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2206: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2207: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2208: goto out;
2209: if (cipher_authlen(enc->cipher) == 0) {
2210: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2211: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2212: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2213: goto out;
2214: }
2215: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2216: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2217: goto out;
2218: r = sshbuf_put_stringb(m, b);
2219: out:
1.221 mmcc 2220: sshbuf_free(b);
1.201 markus 2221: return r;
2222: }
2223:
2224: /* serialize packet state into a blob */
2225: int
2226: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2227: {
2228: struct session_state *state = ssh->state;
1.249 djm 2229: int r;
1.201 markus 2230:
1.249 djm 2231: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2232: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2233: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2234: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2235: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2236: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2237: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2238: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2239: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2240: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2241: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2242: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2243: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2244: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2245: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 2246: return r;
1.201 markus 2247:
2248: return 0;
2249: }
2250:
2251: /* restore key exchange results from blob for packet state de-serialization */
2252: static int
2253: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2254: {
2255: struct sshbuf *b = NULL;
2256: struct sshcomp *comp;
2257: struct sshenc *enc;
2258: struct sshmac *mac;
2259: struct newkeys *newkey = NULL;
2260: size_t keylen, ivlen, maclen;
2261: int r;
2262:
2263: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2264: r = SSH_ERR_ALLOC_FAIL;
2265: goto out;
2266: }
2267: if ((r = sshbuf_froms(m, &b)) != 0)
2268: goto out;
2269: #ifdef DEBUG_PK
2270: sshbuf_dump(b, stderr);
2271: #endif
2272: enc = &newkey->enc;
2273: mac = &newkey->mac;
2274: comp = &newkey->comp;
2275:
2276: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2277: (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2278: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2279: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2280: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2281: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2282: goto out;
2283: if (cipher_authlen(enc->cipher) == 0) {
2284: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2285: goto out;
2286: if ((r = mac_setup(mac, mac->name)) != 0)
2287: goto out;
2288: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2289: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2290: goto out;
2291: if (maclen > mac->key_len) {
2292: r = SSH_ERR_INVALID_FORMAT;
2293: goto out;
2294: }
2295: mac->key_len = maclen;
2296: }
2297: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2298: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2299: goto out;
2300: if (enc->name == NULL ||
2301: cipher_by_name(enc->name) != enc->cipher) {
2302: r = SSH_ERR_INVALID_FORMAT;
2303: goto out;
2304: }
2305: if (sshbuf_len(b) != 0) {
2306: r = SSH_ERR_INVALID_FORMAT;
2307: goto out;
2308: }
2309: enc->key_len = keylen;
2310: enc->iv_len = ivlen;
2311: ssh->kex->newkeys[mode] = newkey;
2312: newkey = NULL;
2313: r = 0;
2314: out:
1.219 mmcc 2315: free(newkey);
1.221 mmcc 2316: sshbuf_free(b);
1.201 markus 2317: return r;
2318: }
2319:
2320: /* restore kex from blob for packet state de-serialization */
2321: static int
2322: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2323: {
2324: struct kex *kex;
2325: int r;
2326:
2327: if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2328: (kex->my = sshbuf_new()) == NULL ||
2329: (kex->peer = sshbuf_new()) == NULL) {
2330: r = SSH_ERR_ALLOC_FAIL;
2331: goto out;
2332: }
2333: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2334: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2335: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2336: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2337: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2338: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2339: (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2340: (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2341: (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2342: goto out;
2343: kex->server = 1;
2344: kex->done = 1;
2345: r = 0;
2346: out:
2347: if (r != 0 || kexp == NULL) {
2348: if (kex != NULL) {
1.221 mmcc 2349: sshbuf_free(kex->my);
2350: sshbuf_free(kex->peer);
1.201 markus 2351: free(kex);
2352: }
2353: if (kexp != NULL)
2354: *kexp = NULL;
2355: } else {
2356: *kexp = kex;
2357: }
2358: return r;
2359: }
2360:
2361: /*
2362: * Restore packet state from content of blob 'm' (de-serialization).
2363: * Note that 'm' will be partially consumed on parsing or any other errors.
2364: */
2365: int
2366: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2367: {
2368: struct session_state *state = ssh->state;
1.254 djm 2369: const u_char *input, *output;
2370: size_t ilen, olen;
1.201 markus 2371: int r;
2372:
1.249 djm 2373: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2374: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2375: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2376: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2377: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2378: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2379: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2380: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2381: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2382: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2383: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2384: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2385: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2386: return r;
2387: /*
2388: * We set the time here so that in post-auth privsep slave we
2389: * count from the completion of the authentication.
2390: */
2391: state->rekey_time = monotime();
2392: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2393: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2394: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2395: return r;
1.201 markus 2396:
1.239 djm 2397: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2398: return r;
2399:
2400: sshbuf_reset(state->input);
2401: sshbuf_reset(state->output);
2402: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2403: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2404: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2405: (r = sshbuf_put(state->output, output, olen)) != 0)
2406: return r;
2407:
2408: if (sshbuf_len(m))
2409: return SSH_ERR_INVALID_FORMAT;
2410: debug3("%s: done", __func__);
2411: return 0;
2412: }
2413:
2414: /* NEW API */
2415:
2416: /* put data to the outgoing packet */
2417:
2418: int
2419: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2420: {
2421: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2422: }
2423:
2424: int
2425: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2426: {
2427: return sshbuf_putb(ssh->state->outgoing_packet, b);
2428: }
2429:
2430: int
2431: sshpkt_put_u8(struct ssh *ssh, u_char val)
2432: {
2433: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2434: }
2435:
2436: int
2437: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2438: {
2439: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2440: }
2441:
2442: int
2443: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2444: {
2445: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2446: }
2447:
2448: int
2449: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2450: {
2451: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2452: }
2453:
2454: int
2455: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2456: {
2457: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2458: }
2459:
2460: int
2461: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2462: {
2463: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2464: }
2465:
1.211 djm 2466: #ifdef WITH_OPENSSL
1.201 markus 2467: int
2468: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2469: {
2470: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2471: }
2472:
2473:
2474: int
2475: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2476: {
2477: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2478: }
1.211 djm 2479: #endif /* WITH_OPENSSL */
1.201 markus 2480:
2481: /* fetch data from the incoming packet */
2482:
2483: int
2484: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2485: {
2486: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2487: }
2488:
2489: int
2490: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2491: {
2492: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2493: }
2494:
2495: int
2496: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2497: {
2498: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2499: }
2500:
2501: int
2502: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2503: {
2504: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2505: }
2506:
2507: int
2508: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2509: {
2510: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2511: }
2512:
2513: int
2514: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2515: {
2516: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2517: }
2518:
2519: int
2520: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2521: {
2522: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2523: }
2524:
1.211 djm 2525: #ifdef WITH_OPENSSL
1.201 markus 2526: int
2527: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2528: {
2529: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2530: }
2531:
2532:
2533: int
2534: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2535: {
2536: return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2537: }
1.211 djm 2538: #endif /* WITH_OPENSSL */
1.201 markus 2539:
2540: int
2541: sshpkt_get_end(struct ssh *ssh)
2542: {
2543: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2544: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2545: return 0;
2546: }
2547:
2548: const u_char *
2549: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2550: {
2551: if (lenp != NULL)
2552: *lenp = sshbuf_len(ssh->state->incoming_packet);
2553: return sshbuf_ptr(ssh->state->incoming_packet);
2554: }
2555:
2556: /* start a new packet */
2557:
2558: int
2559: sshpkt_start(struct ssh *ssh, u_char type)
2560: {
1.249 djm 2561: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2562:
2563: DBG(debug("packet_start[%d]", type));
1.249 djm 2564: memset(buf, 0, sizeof(buf));
2565: buf[sizeof(buf) - 1] = type;
1.201 markus 2566: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2567: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2568: }
2569:
1.242 markus 2570: static int
2571: ssh_packet_send_mux(struct ssh *ssh)
2572: {
2573: struct session_state *state = ssh->state;
2574: u_char type, *cp;
2575: size_t len;
2576: int r;
2577:
2578: if (ssh->kex)
2579: return SSH_ERR_INTERNAL_ERROR;
2580: len = sshbuf_len(state->outgoing_packet);
2581: if (len < 6)
2582: return SSH_ERR_INTERNAL_ERROR;
2583: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2584: type = cp[5];
2585: if (ssh_packet_log_type(type))
2586: debug3("%s: type %u", __func__, type);
2587: /* drop everything, but the connection protocol */
2588: if (type >= SSH2_MSG_CONNECTION_MIN &&
2589: type <= SSH2_MSG_CONNECTION_MAX) {
2590: POKE_U32(cp, len - 4);
2591: if ((r = sshbuf_putb(state->output,
2592: state->outgoing_packet)) != 0)
2593: return r;
2594: /* sshbuf_dump(state->output, stderr); */
2595: }
2596: sshbuf_reset(state->outgoing_packet);
2597: return 0;
2598: }
2599:
1.201 markus 2600: /* send it */
2601:
2602: int
2603: sshpkt_send(struct ssh *ssh)
2604: {
1.242 markus 2605: if (ssh->state && ssh->state->mux)
2606: return ssh_packet_send_mux(ssh);
1.249 djm 2607: return ssh_packet_send2(ssh);
1.201 markus 2608: }
2609:
2610: int
2611: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2612: {
2613: char buf[1024];
2614: va_list args;
2615: int r;
2616:
2617: va_start(args, fmt);
2618: vsnprintf(buf, sizeof(buf), fmt, args);
2619: va_end(args);
2620:
1.249 djm 2621: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2622: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2623: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2624: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2625: (r = sshpkt_send(ssh)) != 0)
2626: return r;
1.201 markus 2627: return 0;
2628: }
2629:
2630: /* roundup current message to pad bytes */
2631: int
2632: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2633: {
2634: ssh->state->extra_pad = pad;
2635: return 0;
1.1 deraadt 2636: }