Annotation of src/usr.bin/ssh/packet.c, Revision 1.257
1.257 ! markus 1: /* $OpenBSD: packet.c,v 1.256 2017/05/08 06:03:39 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: shutdown(state->connection_out, SHUT_RDWR);
! 563: close(state->connection_out);
! 564: } else {
! 565: close(state->connection_in);
! 566: close(state->connection_out);
! 567: }
1.14 markus 568: }
1.201 markus 569: sshbuf_free(state->input);
570: sshbuf_free(state->output);
571: sshbuf_free(state->outgoing_packet);
572: sshbuf_free(state->incoming_packet);
1.257 ! markus 573: for (mode = 0; mode < MODE_MAX; mode++) {
! 574: kex_free_newkeys(state->newkeys[mode]); /* current keys */
! 575: state->newkeys[mode] = NULL;
! 576: ssh_clear_newkeys(ssh, mode); /* next keys */
! 577: }
! 578: /* comression state is in shared mem, so we can only release it once */
! 579: if (do_close && state->compression_buffer) {
1.201 markus 580: sshbuf_free(state->compression_buffer);
581: if (state->compression_out_started) {
582: z_streamp stream = &state->compression_out_stream;
583: debug("compress outgoing: "
584: "raw data %llu, compressed %llu, factor %.2f",
585: (unsigned long long)stream->total_in,
586: (unsigned long long)stream->total_out,
587: stream->total_in == 0 ? 0.0 :
588: (double) stream->total_out / stream->total_in);
589: if (state->compression_out_failures == 0)
590: deflateEnd(stream);
591: }
592: if (state->compression_in_started) {
593: z_streamp stream = &state->compression_out_stream;
594: debug("compress incoming: "
595: "raw data %llu, compressed %llu, factor %.2f",
596: (unsigned long long)stream->total_out,
597: (unsigned long long)stream->total_in,
598: stream->total_out == 0 ? 0.0 :
599: (double) stream->total_in / stream->total_out);
600: if (state->compression_in_failures == 0)
601: inflateEnd(stream);
602: }
1.14 markus 603: }
1.235 djm 604: cipher_free(state->send_context);
605: cipher_free(state->receive_context);
606: state->send_context = state->receive_context = NULL;
1.257 ! markus 607: if (do_close) {
! 608: free(ssh->remote_ipaddr);
! 609: ssh->remote_ipaddr = NULL;
! 610: free(ssh->state);
! 611: ssh->state = NULL;
! 612: }
! 613: }
! 614:
! 615: void
! 616: ssh_packet_close(struct ssh *ssh)
! 617: {
! 618: ssh_packet_close_internal(ssh, 1);
! 619: }
! 620:
! 621: void
! 622: ssh_packet_clear_keys(struct ssh *ssh)
! 623: {
! 624: ssh_packet_close_internal(ssh, 0);
1.1 deraadt 625: }
626:
627: /* Sets remote side protocol flags. */
628:
1.2 provos 629: void
1.201 markus 630: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 631: {
1.201 markus 632: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 633: }
634:
635: /* Returns the remote protocol flags set earlier by the above function. */
636:
1.40 markus 637: u_int
1.201 markus 638: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 639: {
1.201 markus 640: return ssh->state->remote_protocol_flags;
1.1 deraadt 641: }
642:
1.16 markus 643: /*
644: * Starts packet compression from the next packet on in both directions.
645: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
646: */
1.1 deraadt 647:
1.201 markus 648: static int
649: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 650: {
1.201 markus 651: if (!ssh->state->compression_buffer &&
652: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
653: return SSH_ERR_ALLOC_FAIL;
654: return 0;
1.60 markus 655: }
656:
1.201 markus 657: static int
658: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 659: {
1.201 markus 660: if (level < 1 || level > 9)
661: return SSH_ERR_INVALID_ARGUMENT;
662: debug("Enabling compression at level %d.", level);
663: if (ssh->state->compression_out_started == 1)
664: deflateEnd(&ssh->state->compression_out_stream);
665: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
666: case Z_OK:
667: ssh->state->compression_out_started = 1;
668: break;
669: case Z_MEM_ERROR:
670: return SSH_ERR_ALLOC_FAIL;
671: default:
672: return SSH_ERR_INTERNAL_ERROR;
673: }
674: return 0;
1.1 deraadt 675: }
676:
1.201 markus 677: static int
678: start_compression_in(struct ssh *ssh)
679: {
680: if (ssh->state->compression_in_started == 1)
681: inflateEnd(&ssh->state->compression_in_stream);
682: switch (inflateInit(&ssh->state->compression_in_stream)) {
683: case Z_OK:
684: ssh->state->compression_in_started = 1;
685: break;
686: case Z_MEM_ERROR:
687: return SSH_ERR_ALLOC_FAIL;
688: default:
689: return SSH_ERR_INTERNAL_ERROR;
690: }
691: return 0;
692: }
1.95 markus 693:
1.201 markus 694: int
695: ssh_packet_start_compression(struct ssh *ssh, int level)
1.1 deraadt 696: {
1.197 djm 697: int r;
1.97 deraadt 698:
1.249 djm 699: if (ssh->state->packet_compression)
1.201 markus 700: return SSH_ERR_INTERNAL_ERROR;
701: ssh->state->packet_compression = 1;
702: if ((r = ssh_packet_init_compression(ssh)) != 0 ||
703: (r = start_compression_in(ssh)) != 0 ||
704: (r = start_compression_out(ssh, level)) != 0)
705: return r;
706: return 0;
1.95 markus 707: }
708:
1.201 markus 709: /* XXX remove need for separate compression buffer */
710: static int
711: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 712: {
1.201 markus 713: u_char buf[4096];
714: int r, status;
715:
716: if (ssh->state->compression_out_started != 1)
717: return SSH_ERR_INTERNAL_ERROR;
718:
719: /* This case is not handled below. */
720: if (sshbuf_len(in) == 0)
721: return 0;
722:
723: /* Input is the contents of the input buffer. */
724: if ((ssh->state->compression_out_stream.next_in =
725: sshbuf_mutable_ptr(in)) == NULL)
726: return SSH_ERR_INTERNAL_ERROR;
727: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
728:
729: /* Loop compressing until deflate() returns with avail_out != 0. */
730: do {
731: /* Set up fixed-size output buffer. */
732: ssh->state->compression_out_stream.next_out = buf;
733: ssh->state->compression_out_stream.avail_out = sizeof(buf);
734:
735: /* Compress as much data into the buffer as possible. */
736: status = deflate(&ssh->state->compression_out_stream,
737: Z_PARTIAL_FLUSH);
738: switch (status) {
739: case Z_MEM_ERROR:
740: return SSH_ERR_ALLOC_FAIL;
741: case Z_OK:
742: /* Append compressed data to output_buffer. */
743: if ((r = sshbuf_put(out, buf, sizeof(buf) -
744: ssh->state->compression_out_stream.avail_out)) != 0)
745: return r;
746: break;
747: case Z_STREAM_ERROR:
748: default:
749: ssh->state->compression_out_failures++;
750: return SSH_ERR_INVALID_FORMAT;
751: }
752: } while (ssh->state->compression_out_stream.avail_out == 0);
753: return 0;
1.1 deraadt 754: }
755:
1.201 markus 756: static int
757: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 758: {
1.201 markus 759: u_char buf[4096];
760: int r, status;
1.1 deraadt 761:
1.201 markus 762: if (ssh->state->compression_in_started != 1)
763: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 764:
1.201 markus 765: if ((ssh->state->compression_in_stream.next_in =
766: sshbuf_mutable_ptr(in)) == NULL)
767: return SSH_ERR_INTERNAL_ERROR;
768: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 769:
1.201 markus 770: for (;;) {
771: /* Set up fixed-size output buffer. */
772: ssh->state->compression_in_stream.next_out = buf;
773: ssh->state->compression_in_stream.avail_out = sizeof(buf);
774:
775: status = inflate(&ssh->state->compression_in_stream,
776: Z_PARTIAL_FLUSH);
777: switch (status) {
778: case Z_OK:
779: if ((r = sshbuf_put(out, buf, sizeof(buf) -
780: ssh->state->compression_in_stream.avail_out)) != 0)
781: return r;
782: break;
783: case Z_BUF_ERROR:
784: /*
785: * Comments in zlib.h say that we should keep calling
786: * inflate() until we get an error. This appears to
787: * be the error that we get.
788: */
789: return 0;
790: case Z_DATA_ERROR:
791: return SSH_ERR_INVALID_FORMAT;
792: case Z_MEM_ERROR:
793: return SSH_ERR_ALLOC_FAIL;
794: case Z_STREAM_ERROR:
795: default:
796: ssh->state->compression_in_failures++;
797: return SSH_ERR_INTERNAL_ERROR;
798: }
799: }
800: /* NOTREACHED */
1.170 djm 801: }
802:
1.257 ! markus 803: void
! 804: ssh_clear_newkeys(struct ssh *ssh, int mode)
! 805: {
! 806: if (ssh->kex && ssh->kex->newkeys) {
! 807: kex_free_newkeys(ssh->kex->newkeys[mode]);
! 808: ssh->kex->newkeys[mode] = NULL;
! 809: }
! 810: }
! 811:
1.201 markus 812: int
813: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 814: {
1.201 markus 815: struct session_state *state = ssh->state;
816: struct sshenc *enc;
817: struct sshmac *mac;
818: struct sshcomp *comp;
1.235 djm 819: struct sshcipher_ctx **ccp;
1.236 markus 820: struct packet_state *ps;
1.105 markus 821: u_int64_t *max_blocks;
1.236 markus 822: const char *wmsg, *dir;
1.197 djm 823: int r, crypt_type;
1.57 markus 824:
1.100 markus 825: debug2("set_newkeys: mode %d", mode);
1.57 markus 826:
1.88 markus 827: if (mode == MODE_OUT) {
1.236 markus 828: dir = "output";
1.235 djm 829: ccp = &state->send_context;
1.115 avsm 830: crypt_type = CIPHER_ENCRYPT;
1.236 markus 831: ps = &state->p_send;
1.201 markus 832: max_blocks = &state->max_blocks_out;
1.88 markus 833: } else {
1.236 markus 834: dir = "input";
1.235 djm 835: ccp = &state->receive_context;
1.115 avsm 836: crypt_type = CIPHER_DECRYPT;
1.236 markus 837: ps = &state->p_read;
1.201 markus 838: max_blocks = &state->max_blocks_in;
1.88 markus 839: }
1.201 markus 840: if (state->newkeys[mode] != NULL) {
1.257 ! markus 841: debug("set_newkeys: rekeying, input %llu bytes %llu blocks, "
! 842: "output %llu bytes %llu blocks",
! 843: (unsigned long long)state->p_read.bytes,
! 844: (unsigned long long)state->p_read.blocks,
! 845: (unsigned long long)state->p_send.bytes,
! 846: (unsigned long long)state->p_send.blocks);
1.235 djm 847: cipher_free(*ccp);
848: *ccp = NULL;
1.257 ! markus 849: kex_free_newkeys(state->newkeys[mode]);
! 850: state->newkeys[mode] = NULL;
1.57 markus 851: }
1.236 markus 852: /* note that both bytes and the seqnr are not reset */
853: ps->packets = ps->blocks = 0;
1.201 markus 854: /* move newkeys from kex to state */
855: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
856: return SSH_ERR_INTERNAL_ERROR;
857: ssh->kex->newkeys[mode] = NULL;
858: enc = &state->newkeys[mode]->enc;
859: mac = &state->newkeys[mode]->mac;
860: comp = &state->newkeys[mode]->comp;
861: if (cipher_authlen(enc->cipher) == 0) {
862: if ((r = mac_init(mac)) != 0)
863: return r;
864: }
865: mac->enabled = 1;
1.57 markus 866: DBG(debug("cipher_init_context: %d", mode));
1.235 djm 867: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 868: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 869: return r;
870: if (!state->cipher_warning_done &&
1.235 djm 871: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 872: error("Warning: %s", wmsg);
873: state->cipher_warning_done = 1;
874: }
1.91 markus 875: /* Deleting the keys does not gain extra security */
1.192 djm 876: /* explicit_bzero(enc->iv, enc->block_size);
877: explicit_bzero(enc->key, enc->key_len);
878: explicit_bzero(mac->key, mac->key_len); */
1.241 djm 879: if ((comp->type == COMP_ZLIB ||
880: (comp->type == COMP_DELAYED &&
881: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 882: if ((r = ssh_packet_init_compression(ssh)) < 0)
883: return r;
884: if (mode == MODE_OUT) {
885: if ((r = start_compression_out(ssh, 6)) != 0)
886: return r;
887: } else {
888: if ((r = start_compression_in(ssh)) != 0)
889: return r;
890: }
1.57 markus 891: comp->enabled = 1;
892: }
1.109 markus 893: /*
894: * The 2^(blocksize*2) limit is too expensive for 3DES,
1.254 djm 895: * so enforce a 1GB limit for small blocksizes.
1.109 markus 896: */
897: if (enc->block_size >= 16)
898: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
899: else
900: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 901: if (state->rekey_limit)
1.237 deraadt 902: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 903: state->rekey_limit / enc->block_size);
1.227 djm 904: debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1.201 markus 905: return 0;
1.57 markus 906: }
907:
1.228 djm 908: #define MAX_PACKETS (1U<<31)
909: static int
910: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
911: {
912: struct session_state *state = ssh->state;
913: u_int32_t out_blocks;
914:
915: /* XXX client can't cope with rekeying pre-auth */
916: if (!state->after_authentication)
917: return 0;
918:
919: /* Haven't keyed yet or KEX in progress. */
920: if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
921: return 0;
922:
923: /* Peer can't rekey */
924: if (ssh->compat & SSH_BUG_NOREKEY)
925: return 0;
926:
927: /*
928: * Permit one packet in or out per rekey - this allows us to
929: * make progress when rekey limits are very small.
930: */
931: if (state->p_send.packets == 0 && state->p_read.packets == 0)
932: return 0;
933:
934: /* Time-based rekeying */
935: if (state->rekey_interval != 0 &&
1.244 dtucker 936: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 937: return 1;
938:
939: /* Always rekey when MAX_PACKETS sent in either direction */
940: if (state->p_send.packets > MAX_PACKETS ||
941: state->p_read.packets > MAX_PACKETS)
942: return 1;
943:
944: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 945: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 946: state->newkeys[MODE_OUT]->enc.block_size);
947: return (state->max_blocks_out &&
948: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
949: (state->max_blocks_in &&
950: (state->p_read.blocks > state->max_blocks_in));
951: }
952:
1.16 markus 953: /*
1.118 markus 954: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 955: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 956: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
957: */
1.201 markus 958: static int
959: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 960: {
1.201 markus 961: struct session_state *state = ssh->state;
962: struct sshcomp *comp = NULL;
963: int r, mode;
1.118 markus 964:
965: /*
966: * Remember that we are past the authentication step, so rekeying
967: * with COMP_DELAYED will turn on compression immediately.
968: */
1.201 markus 969: state->after_authentication = 1;
1.118 markus 970: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 971: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 972: if (state->newkeys[mode] == NULL)
1.145 markus 973: continue;
1.201 markus 974: comp = &state->newkeys[mode]->comp;
1.118 markus 975: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 976: if ((r = ssh_packet_init_compression(ssh)) != 0)
977: return r;
978: if (mode == MODE_OUT) {
979: if ((r = start_compression_out(ssh, 6)) != 0)
980: return r;
981: } else {
982: if ((r = start_compression_in(ssh)) != 0)
983: return r;
984: }
1.118 markus 985: comp->enabled = 1;
986: }
987: }
1.201 markus 988: return 0;
1.118 markus 989: }
990:
1.226 djm 991: /* Used to mute debug logging for noisy packet types */
1.242 markus 992: int
1.226 djm 993: ssh_packet_log_type(u_char type)
994: {
995: switch (type) {
996: case SSH2_MSG_CHANNEL_DATA:
997: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
998: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
999: return 0;
1000: default:
1001: return 1;
1002: }
1003: }
1004:
1.118 markus 1005: /*
1.25 markus 1006: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1007: */
1.201 markus 1008: int
1009: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1010: {
1.201 markus 1011: struct session_state *state = ssh->state;
1.200 markus 1012: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1013: u_char tmp, padlen, pad = 0;
1.201 markus 1014: u_int authlen = 0, aadlen = 0;
1015: u_int len;
1016: struct sshenc *enc = NULL;
1017: struct sshmac *mac = NULL;
1018: struct sshcomp *comp = NULL;
1019: int r, block_size;
1020:
1021: if (state->newkeys[MODE_OUT] != NULL) {
1022: enc = &state->newkeys[MODE_OUT]->enc;
1023: mac = &state->newkeys[MODE_OUT]->mac;
1024: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1025: /* disable mac for authenticated encryption */
1026: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1027: mac = NULL;
1.25 markus 1028: }
1.88 markus 1029: block_size = enc ? enc->block_size : 8;
1.180 markus 1030: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1031:
1.201 markus 1032: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1033: if (ssh_packet_log_type(type))
1034: debug3("send packet: type %u", type);
1.25 markus 1035: #ifdef PACKET_DEBUG
1036: fprintf(stderr, "plain: ");
1.201 markus 1037: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1038: #endif
1039:
1040: if (comp && comp->enabled) {
1.201 markus 1041: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1042: /* skip header, compress only payload */
1.201 markus 1043: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1044: goto out;
1045: sshbuf_reset(state->compression_buffer);
1046: if ((r = compress_buffer(ssh, state->outgoing_packet,
1047: state->compression_buffer)) != 0)
1048: goto out;
1049: sshbuf_reset(state->outgoing_packet);
1050: if ((r = sshbuf_put(state->outgoing_packet,
1051: "\0\0\0\0\0", 5)) != 0 ||
1052: (r = sshbuf_putb(state->outgoing_packet,
1053: state->compression_buffer)) != 0)
1054: goto out;
1055: DBG(debug("compression: raw %d compressed %zd", len,
1056: sshbuf_len(state->outgoing_packet)));
1.25 markus 1057: }
1058:
1059: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1060: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1061:
1062: /*
1063: * calc size of padding, alloc space, get random data,
1064: * minimum padding is 4 bytes
1065: */
1.178 markus 1066: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1067: padlen = block_size - (len % block_size);
1068: if (padlen < 4)
1069: padlen += block_size;
1.201 markus 1070: if (state->extra_pad) {
1.233 djm 1071: tmp = state->extra_pad;
1.201 markus 1072: state->extra_pad =
1.237 deraadt 1073: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1074: /* check if roundup overflowed */
1075: if (state->extra_pad < tmp)
1076: return SSH_ERR_INVALID_ARGUMENT;
1077: tmp = (len + padlen) % state->extra_pad;
1078: /* Check whether pad calculation below will underflow */
1079: if (tmp > state->extra_pad)
1080: return SSH_ERR_INVALID_ARGUMENT;
1081: pad = state->extra_pad - tmp;
1.193 djm 1082: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1083: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1084: tmp = padlen;
1.71 markus 1085: padlen += pad;
1.233 djm 1086: /* Check whether padlen calculation overflowed */
1087: if (padlen < tmp)
1088: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1089: state->extra_pad = 0;
1.71 markus 1090: }
1.201 markus 1091: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1092: goto out;
1.235 djm 1093: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1094: /* random padding */
1.201 markus 1095: arc4random_buf(cp, padlen);
1.32 markus 1096: } else {
1097: /* clear padding */
1.192 djm 1098: explicit_bzero(cp, padlen);
1.25 markus 1099: }
1.178 markus 1100: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1101: len = sshbuf_len(state->outgoing_packet);
1102: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1103: if (cp == NULL) {
1104: r = SSH_ERR_INTERNAL_ERROR;
1105: goto out;
1106: }
1.25 markus 1107: /* packet_length includes payload, padding and padding length field */
1.201 markus 1108: POKE_U32(cp, len - 4);
1.89 markus 1109: cp[4] = padlen;
1.178 markus 1110: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1111: len, padlen, aadlen));
1.25 markus 1112:
1113: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1114: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1115: if ((r = mac_compute(mac, state->p_send.seqnr,
1116: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1117: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1118: goto out;
1119: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1120: }
1121: /* encrypt packet and append to output buffer. */
1.201 markus 1122: if ((r = sshbuf_reserve(state->output,
1123: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1124: goto out;
1.235 djm 1125: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1126: sshbuf_ptr(state->outgoing_packet),
1127: len - aadlen, aadlen, authlen)) != 0)
1128: goto out;
1.25 markus 1129: /* append unencrypted MAC */
1.178 markus 1130: if (mac && mac->enabled) {
1131: if (mac->etm) {
1132: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1133: if ((r = mac_compute(mac, state->p_send.seqnr,
1134: cp, len, macbuf, sizeof(macbuf))) != 0)
1135: goto out;
1.178 markus 1136: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1137: state->p_send.seqnr));
1.178 markus 1138: }
1.201 markus 1139: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1140: goto out;
1.178 markus 1141: }
1.25 markus 1142: #ifdef PACKET_DEBUG
1143: fprintf(stderr, "encrypted: ");
1.201 markus 1144: sshbuf_dump(state->output, stderr);
1.25 markus 1145: #endif
1.29 markus 1146: /* increment sequence number for outgoing packets */
1.201 markus 1147: if (++state->p_send.seqnr == 0)
1.106 itojun 1148: logit("outgoing seqnr wraps around");
1.201 markus 1149: if (++state->p_send.packets == 0)
1150: if (!(ssh->compat & SSH_BUG_NOREKEY))
1151: return SSH_ERR_NEED_REKEY;
1152: state->p_send.blocks += len / block_size;
1153: state->p_send.bytes += len;
1154: sshbuf_reset(state->outgoing_packet);
1.25 markus 1155:
1.57 markus 1156: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1157: r = ssh_set_newkeys(ssh, MODE_OUT);
1158: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1159: r = ssh_packet_enable_delayed_compress(ssh);
1160: else
1161: r = 0;
1162: out:
1163: return r;
1.25 markus 1164: }
1165:
1.228 djm 1166: /* returns non-zero if the specified packet type is usec by KEX */
1167: static int
1168: ssh_packet_type_is_kex(u_char type)
1169: {
1170: return
1171: type >= SSH2_MSG_TRANSPORT_MIN &&
1172: type <= SSH2_MSG_TRANSPORT_MAX &&
1173: type != SSH2_MSG_SERVICE_REQUEST &&
1174: type != SSH2_MSG_SERVICE_ACCEPT &&
1175: type != SSH2_MSG_EXT_INFO;
1176: }
1177:
1.201 markus 1178: int
1179: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1180: {
1.201 markus 1181: struct session_state *state = ssh->state;
1.105 markus 1182: struct packet *p;
1.201 markus 1183: u_char type;
1.228 djm 1184: int r, need_rekey;
1.105 markus 1185:
1.228 djm 1186: if (sshbuf_len(state->outgoing_packet) < 6)
1187: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1188: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1189: need_rekey = !ssh_packet_type_is_kex(type) &&
1190: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1191:
1.228 djm 1192: /*
1193: * During rekeying we can only send key exchange messages.
1194: * Queue everything else.
1195: */
1196: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1197: if (need_rekey)
1198: debug3("%s: rekex triggered", __func__);
1199: debug("enqueue packet: %u", type);
1200: p = calloc(1, sizeof(*p));
1201: if (p == NULL)
1202: return SSH_ERR_ALLOC_FAIL;
1203: p->type = type;
1204: p->payload = state->outgoing_packet;
1205: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1206: state->outgoing_packet = sshbuf_new();
1207: if (state->outgoing_packet == NULL)
1208: return SSH_ERR_ALLOC_FAIL;
1209: if (need_rekey) {
1210: /*
1211: * This packet triggered a rekey, so send the
1212: * KEXINIT now.
1213: * NB. reenters this function via kex_start_rekex().
1214: */
1215: return kex_start_rekex(ssh);
1.105 markus 1216: }
1.228 djm 1217: return 0;
1.105 markus 1218: }
1219:
1220: /* rekeying starts with sending KEXINIT */
1221: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1222: state->rekeying = 1;
1.105 markus 1223:
1.201 markus 1224: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1225: return r;
1.105 markus 1226:
1227: /* after a NEWKEYS message we can send the complete queue */
1228: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1229: state->rekeying = 0;
1230: state->rekey_time = monotime();
1231: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1232: type = p->type;
1.228 djm 1233: /*
1234: * If this packet triggers a rekex, then skip the
1235: * remaining packets in the queue for now.
1236: * NB. re-enters this function via kex_start_rekex.
1237: */
1238: if (ssh_packet_need_rekeying(ssh,
1239: sshbuf_len(p->payload))) {
1240: debug3("%s: queued packet triggered rekex",
1241: __func__);
1242: return kex_start_rekex(ssh);
1243: }
1.105 markus 1244: debug("dequeue packet: %u", type);
1.201 markus 1245: sshbuf_free(state->outgoing_packet);
1246: state->outgoing_packet = p->payload;
1247: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1248: memset(p, 0, sizeof(*p));
1.186 djm 1249: free(p);
1.201 markus 1250: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1251: return r;
1.105 markus 1252: }
1253: }
1.201 markus 1254: return 0;
1.25 markus 1255: }
1256:
1257: /*
1.16 markus 1258: * Waits until a packet has been received, and returns its type. Note that
1259: * no other data is processed until this returns, so this function should not
1260: * be used during the interactive session.
1261: */
1.1 deraadt 1262:
1.2 provos 1263: int
1.201 markus 1264: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1265: {
1.201 markus 1266: struct session_state *state = ssh->state;
1.222 markus 1267: int len, r, ms_remain;
1.56 millert 1268: fd_set *setp;
1.14 markus 1269: char buf[8192];
1.155 deraadt 1270: struct timeval timeout, start, *timeoutp = NULL;
1271:
1.25 markus 1272: DBG(debug("packet_read()"));
1.14 markus 1273:
1.214 deraadt 1274: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1275: NFDBITS), sizeof(fd_mask));
1.201 markus 1276: if (setp == NULL)
1277: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1278:
1.205 djm 1279: /*
1280: * Since we are blocking, ensure that all written packets have
1281: * been sent.
1282: */
1.210 markus 1283: if ((r = ssh_packet_write_wait(ssh)) != 0)
1284: goto out;
1.14 markus 1285:
1286: /* Stay in the loop until we have received a complete packet. */
1287: for (;;) {
1288: /* Try to read a packet from the buffer. */
1.201 markus 1289: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1290: if (r != 0)
1291: break;
1.14 markus 1292: /* If we got a packet, return it. */
1.201 markus 1293: if (*typep != SSH_MSG_NONE)
1294: break;
1.16 markus 1295: /*
1296: * Otherwise, wait for some data to arrive, add it to the
1297: * buffer, and try again.
1298: */
1.201 markus 1299: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1300: NFDBITS) * sizeof(fd_mask));
1.201 markus 1301: FD_SET(state->connection_in, setp);
1.16 markus 1302:
1.201 markus 1303: if (state->packet_timeout_ms > 0) {
1304: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1305: timeoutp = &timeout;
1306: }
1.14 markus 1307: /* Wait for some data to arrive. */
1.154 dtucker 1308: for (;;) {
1.201 markus 1309: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1310: ms_to_timeval(&timeout, ms_remain);
1311: gettimeofday(&start, NULL);
1312: }
1.201 markus 1313: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1314: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1315: break;
1.161 andreas 1316: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1317: break;
1.201 markus 1318: if (state->packet_timeout_ms == -1)
1.154 dtucker 1319: continue;
1320: ms_subtract_diff(&start, &ms_remain);
1321: if (ms_remain <= 0) {
1.201 markus 1322: r = 0;
1.154 dtucker 1323: break;
1324: }
1325: }
1.246 djm 1326: if (r == 0) {
1327: r = SSH_ERR_CONN_TIMEOUT;
1328: goto out;
1329: }
1.14 markus 1330: /* Read data from the socket. */
1.222 markus 1331: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1332: if (len == 0) {
1333: r = SSH_ERR_CONN_CLOSED;
1334: goto out;
1335: }
1336: if (len < 0) {
1337: r = SSH_ERR_SYSTEM_ERROR;
1338: goto out;
1339: }
1.204 djm 1340:
1.14 markus 1341: /* Append it to the buffer. */
1.204 djm 1342: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1343: goto out;
1.14 markus 1344: }
1.210 markus 1345: out:
1.201 markus 1346: free(setp);
1347: return r;
1.1 deraadt 1348: }
1349:
1.77 djm 1350: int
1.201 markus 1351: ssh_packet_read(struct ssh *ssh)
1.77 djm 1352: {
1.201 markus 1353: u_char type;
1354: int r;
1355:
1356: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1357: fatal("%s: %s", __func__, ssh_err(r));
1358: return type;
1.77 djm 1359: }
1360:
1.16 markus 1361: /*
1362: * Waits until a packet has been received, verifies that its type matches
1363: * that given, and gives a fatal error and exits if there is a mismatch.
1364: */
1.1 deraadt 1365:
1.205 djm 1366: int
1367: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1368: {
1.205 djm 1369: int r;
1370: u_char type;
1.1 deraadt 1371:
1.205 djm 1372: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1373: return r;
1374: if (type != expected_type) {
1375: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1376: "Protocol error: expected packet type %d, got %d",
1.205 djm 1377: expected_type, type)) != 0)
1378: return r;
1379: return SSH_ERR_PROTOCOL_ERROR;
1380: }
1381: return 0;
1.1 deraadt 1382: }
1.14 markus 1383:
1.242 markus 1384: static int
1385: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1386: {
1387: struct session_state *state = ssh->state;
1388: const u_char *cp;
1389: size_t need;
1390: int r;
1391:
1392: if (ssh->kex)
1393: return SSH_ERR_INTERNAL_ERROR;
1394: *typep = SSH_MSG_NONE;
1395: cp = sshbuf_ptr(state->input);
1396: if (state->packlen == 0) {
1397: if (sshbuf_len(state->input) < 4 + 1)
1398: return 0; /* packet is incomplete */
1399: state->packlen = PEEK_U32(cp);
1400: if (state->packlen < 4 + 1 ||
1401: state->packlen > PACKET_MAX_SIZE)
1402: return SSH_ERR_MESSAGE_INCOMPLETE;
1403: }
1404: need = state->packlen + 4;
1405: if (sshbuf_len(state->input) < need)
1406: return 0; /* packet is incomplete */
1407: sshbuf_reset(state->incoming_packet);
1408: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1409: state->packlen)) != 0 ||
1410: (r = sshbuf_consume(state->input, need)) != 0 ||
1411: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1412: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1413: return r;
1414: if (ssh_packet_log_type(*typep))
1415: debug3("%s: type %u", __func__, *typep);
1416: /* sshbuf_dump(state->incoming_packet, stderr); */
1417: /* reset for next packet */
1418: state->packlen = 0;
1419: return r;
1420: }
1421:
1.201 markus 1422: int
1423: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1424: {
1.201 markus 1425: struct session_state *state = ssh->state;
1.40 markus 1426: u_int padlen, need;
1.231 djm 1427: u_char *cp;
1.201 markus 1428: u_int maclen, aadlen = 0, authlen = 0, block_size;
1429: struct sshenc *enc = NULL;
1430: struct sshmac *mac = NULL;
1431: struct sshcomp *comp = NULL;
1.200 markus 1432: int r;
1.201 markus 1433:
1.242 markus 1434: if (state->mux)
1435: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1436:
1.201 markus 1437: *typep = SSH_MSG_NONE;
1438:
1439: if (state->packet_discard)
1440: return 0;
1441:
1442: if (state->newkeys[MODE_IN] != NULL) {
1443: enc = &state->newkeys[MODE_IN]->enc;
1444: mac = &state->newkeys[MODE_IN]->mac;
1445: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1446: /* disable mac for authenticated encryption */
1447: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1448: mac = NULL;
1.25 markus 1449: }
1450: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1451: block_size = enc ? enc->block_size : 8;
1.180 markus 1452: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1453:
1.201 markus 1454: if (aadlen && state->packlen == 0) {
1.235 djm 1455: if (cipher_get_length(state->receive_context,
1.201 markus 1456: &state->packlen, state->p_read.seqnr,
1457: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1458: return 0;
1459: if (state->packlen < 1 + 4 ||
1460: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1461: #ifdef PACKET_DEBUG
1.201 markus 1462: sshbuf_dump(state->input, stderr);
1.178 markus 1463: #endif
1.201 markus 1464: logit("Bad packet length %u.", state->packlen);
1465: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1466: return r;
1.217 djm 1467: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1468: }
1.201 markus 1469: sshbuf_reset(state->incoming_packet);
1470: } else if (state->packlen == 0) {
1.25 markus 1471: /*
1472: * check if input size is less than the cipher block size,
1473: * decrypt first block and extract length of incoming packet
1474: */
1.201 markus 1475: if (sshbuf_len(state->input) < block_size)
1476: return 0;
1477: sshbuf_reset(state->incoming_packet);
1478: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1479: &cp)) != 0)
1480: goto out;
1.235 djm 1481: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1482: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1483: block_size, 0, 0)) != 0)
1484: goto out;
1485: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1486: if (state->packlen < 1 + 4 ||
1487: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1488: #ifdef PACKET_DEBUG
1.201 markus 1489: fprintf(stderr, "input: \n");
1490: sshbuf_dump(state->input, stderr);
1491: fprintf(stderr, "incoming_packet: \n");
1492: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1493: #endif
1.201 markus 1494: logit("Bad packet length %u.", state->packlen);
1.234 markus 1495: return ssh_packet_start_discard(ssh, enc, mac, 0,
1496: PACKET_MAX_SIZE);
1.25 markus 1497: }
1.201 markus 1498: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1499: goto out;
1.25 markus 1500: }
1.201 markus 1501: DBG(debug("input: packet len %u", state->packlen+4));
1502:
1.178 markus 1503: if (aadlen) {
1504: /* only the payload is encrypted */
1.201 markus 1505: need = state->packlen;
1.178 markus 1506: } else {
1507: /*
1508: * the payload size and the payload are encrypted, but we
1509: * have a partial packet of block_size bytes
1510: */
1.201 markus 1511: need = 4 + state->packlen - block_size;
1.178 markus 1512: }
1.180 markus 1513: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1514: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1515: if (need % block_size != 0) {
1516: logit("padding error: need %d block %d mod %d",
1.25 markus 1517: need, block_size, need % block_size);
1.234 markus 1518: return ssh_packet_start_discard(ssh, enc, mac, 0,
1519: PACKET_MAX_SIZE - block_size);
1.158 markus 1520: }
1.25 markus 1521: /*
1522: * check if the entire packet has been received and
1.178 markus 1523: * decrypt into incoming_packet:
1524: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1525: * 'need' bytes are encrypted, followed by either
1526: * 'authlen' bytes of authentication tag or
1.178 markus 1527: * 'maclen' bytes of message authentication code.
1.25 markus 1528: */
1.201 markus 1529: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1530: return 0; /* packet is incomplete */
1.25 markus 1531: #ifdef PACKET_DEBUG
1532: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1533: sshbuf_dump(state->input, stderr);
1.25 markus 1534: #endif
1.231 djm 1535: /* EtM: check mac over encrypted input */
1.201 markus 1536: if (mac && mac->enabled && mac->etm) {
1.231 djm 1537: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1538: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1539: sshbuf_ptr(state->input) + aadlen + need + authlen,
1540: maclen)) != 0) {
1541: if (r == SSH_ERR_MAC_INVALID)
1542: logit("Corrupted MAC on input.");
1.201 markus 1543: goto out;
1.231 djm 1544: }
1.201 markus 1545: }
1546: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1547: &cp)) != 0)
1548: goto out;
1.235 djm 1549: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1550: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1551: goto out;
1552: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1553: goto out;
1.29 markus 1554: if (mac && mac->enabled) {
1.231 djm 1555: /* Not EtM: check MAC over cleartext */
1556: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1557: sshbuf_ptr(state->incoming_packet),
1558: sshbuf_len(state->incoming_packet),
1559: sshbuf_ptr(state->input), maclen)) != 0) {
1560: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1561: goto out;
1.159 markus 1562: logit("Corrupted MAC on input.");
1.247 markus 1563: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1564: return SSH_ERR_INTERNAL_ERROR;
1565: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1566: sshbuf_len(state->incoming_packet),
1.247 markus 1567: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1568: }
1.231 djm 1569: /* Remove MAC from input buffer */
1.201 markus 1570: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1571: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1572: goto out;
1.25 markus 1573: }
1.77 djm 1574: if (seqnr_p != NULL)
1.201 markus 1575: *seqnr_p = state->p_read.seqnr;
1576: if (++state->p_read.seqnr == 0)
1.106 itojun 1577: logit("incoming seqnr wraps around");
1.201 markus 1578: if (++state->p_read.packets == 0)
1579: if (!(ssh->compat & SSH_BUG_NOREKEY))
1580: return SSH_ERR_NEED_REKEY;
1581: state->p_read.blocks += (state->packlen + 4) / block_size;
1582: state->p_read.bytes += state->packlen + 4;
1.25 markus 1583:
1584: /* get padlen */
1.201 markus 1585: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1586: DBG(debug("input: padlen %d", padlen));
1.205 djm 1587: if (padlen < 4) {
1588: if ((r = sshpkt_disconnect(ssh,
1589: "Corrupted padlen %d on input.", padlen)) != 0 ||
1590: (r = ssh_packet_write_wait(ssh)) != 0)
1591: return r;
1592: return SSH_ERR_CONN_CORRUPT;
1593: }
1.25 markus 1594:
1595: /* skip packet size + padlen, discard padding */
1.201 markus 1596: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1597: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1598: goto out;
1.25 markus 1599:
1.201 markus 1600: DBG(debug("input: len before de-compress %zd",
1601: sshbuf_len(state->incoming_packet)));
1.25 markus 1602: if (comp && comp->enabled) {
1.201 markus 1603: sshbuf_reset(state->compression_buffer);
1604: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1605: state->compression_buffer)) != 0)
1606: goto out;
1607: sshbuf_reset(state->incoming_packet);
1608: if ((r = sshbuf_putb(state->incoming_packet,
1609: state->compression_buffer)) != 0)
1610: goto out;
1611: DBG(debug("input: len after de-compress %zd",
1612: sshbuf_len(state->incoming_packet)));
1.25 markus 1613: }
1614: /*
1615: * get packet type, implies consume.
1616: * return length of payload (without type field)
1617: */
1.201 markus 1618: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1619: goto out;
1.226 djm 1620: if (ssh_packet_log_type(*typep))
1621: debug3("receive packet: type %u", *typep);
1.205 djm 1622: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1623: if ((r = sshpkt_disconnect(ssh,
1624: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1625: (r = ssh_packet_write_wait(ssh)) != 0)
1626: return r;
1627: return SSH_ERR_PROTOCOL_ERROR;
1628: }
1.243 djm 1629: if (state->hook_in != NULL &&
1630: (r = state->hook_in(ssh, state->incoming_packet, typep,
1631: state->hook_in_ctx)) != 0)
1632: return r;
1.238 markus 1633: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1634: r = ssh_packet_enable_delayed_compress(ssh);
1635: else
1636: r = 0;
1.25 markus 1637: #ifdef PACKET_DEBUG
1.201 markus 1638: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1639: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1640: #endif
1.62 markus 1641: /* reset for next packet */
1.201 markus 1642: state->packlen = 0;
1.228 djm 1643:
1644: /* do we need to rekey? */
1645: if (ssh_packet_need_rekeying(ssh, 0)) {
1646: debug3("%s: rekex triggered", __func__);
1647: if ((r = kex_start_rekex(ssh)) != 0)
1648: return r;
1649: }
1.201 markus 1650: out:
1651: return r;
1.25 markus 1652: }
1653:
1654: int
1.201 markus 1655: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1656: {
1.201 markus 1657: struct session_state *state = ssh->state;
1.96 deraadt 1658: u_int reason, seqnr;
1.201 markus 1659: int r;
1660: u_char *msg;
1.62 markus 1661:
1.25 markus 1662: for (;;) {
1.201 markus 1663: msg = NULL;
1.249 djm 1664: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1665: if (r != 0)
1666: return r;
1667: if (*typep) {
1668: state->keep_alive_timeouts = 0;
1669: DBG(debug("received packet type %d", *typep));
1670: }
1671: switch (*typep) {
1672: case SSH2_MSG_IGNORE:
1673: debug3("Received SSH2_MSG_IGNORE");
1674: break;
1675: case SSH2_MSG_DEBUG:
1676: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1677: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1678: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1679: free(msg);
1.201 markus 1680: return r;
1.48 stevesk 1681: }
1.249 djm 1682: debug("Remote: %.900s", msg);
1683: free(msg);
1684: break;
1685: case SSH2_MSG_DISCONNECT:
1686: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1687: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1688: return r;
1689: /* Ignore normal client exit notifications */
1690: do_log2(ssh->state->server_side &&
1691: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1692: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1693: "Received disconnect from %s port %d:"
1694: "%u: %.400s", ssh_remote_ipaddr(ssh),
1695: ssh_remote_port(ssh), reason, msg);
1696: free(msg);
1697: return SSH_ERR_DISCONNECTED;
1698: case SSH2_MSG_UNIMPLEMENTED:
1699: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1700: return r;
1701: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1702: seqnr);
1703: break;
1704: default:
1705: return 0;
1.25 markus 1706: }
1707: }
1708: }
1709:
1.16 markus 1710: /*
1711: * Buffers the given amount of input characters. This is intended to be used
1712: * together with packet_read_poll.
1713: */
1.1 deraadt 1714:
1.204 djm 1715: int
1.201 markus 1716: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1717: {
1.201 markus 1718: struct session_state *state = ssh->state;
1719: int r;
1720:
1721: if (state->packet_discard) {
1722: state->keep_alive_timeouts = 0; /* ?? */
1723: if (len >= state->packet_discard) {
1724: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1725: return r;
1.201 markus 1726: }
1727: state->packet_discard -= len;
1.204 djm 1728: return 0;
1.159 markus 1729: }
1.201 markus 1730: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1731: return r;
1732:
1733: return 0;
1.28 markus 1734: }
1735:
1736: int
1.201 markus 1737: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1738: {
1.201 markus 1739: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1740: }
1741:
1.16 markus 1742: /*
1743: * Sends a diagnostic message from the server to the client. This message
1744: * can be sent at any time (but not while constructing another message). The
1745: * message is printed immediately, but only if the client is being executed
1746: * in verbose mode. These messages are primarily intended to ease debugging
1747: * authentication problems. The length of the formatted message must not
1.205 djm 1748: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1749: */
1.2 provos 1750: void
1.201 markus 1751: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1752: {
1.14 markus 1753: char buf[1024];
1754: va_list args;
1.201 markus 1755: int r;
1.39 markus 1756:
1.249 djm 1757: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1758: return;
1.14 markus 1759:
1760: va_start(args, fmt);
1761: vsnprintf(buf, sizeof(buf), fmt, args);
1762: va_end(args);
1763:
1.249 djm 1764: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1765: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1766: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1767: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1768: (r = sshpkt_send(ssh)) != 0 ||
1769: (r = ssh_packet_write_wait(ssh)) != 0)
1.205 djm 1770: fatal("%s: %s", __func__, ssh_err(r));
1771: }
1772:
1.245 djm 1773: static void
1774: fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1775: {
1776: snprintf(s, l, "%.200s%s%s port %d",
1777: ssh->log_preamble ? ssh->log_preamble : "",
1778: ssh->log_preamble ? " " : "",
1779: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1780: }
1781:
1.205 djm 1782: /*
1783: * Pretty-print connection-terminating errors and exit.
1784: */
1785: void
1786: sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
1787: {
1.245 djm 1788: char remote_id[512];
1789:
1790: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1791:
1.205 djm 1792: switch (r) {
1793: case SSH_ERR_CONN_CLOSED:
1.257 ! markus 1794: ssh_packet_clear_keys(ssh);
1.245 djm 1795: logdie("Connection closed by %s", remote_id);
1.205 djm 1796: case SSH_ERR_CONN_TIMEOUT:
1.257 ! markus 1797: ssh_packet_clear_keys(ssh);
1.245 djm 1798: logdie("Connection %s %s timed out",
1799: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1800: case SSH_ERR_DISCONNECTED:
1.257 ! markus 1801: ssh_packet_clear_keys(ssh);
1.245 djm 1802: logdie("Disconnected from %s", remote_id);
1.212 djm 1803: case SSH_ERR_SYSTEM_ERROR:
1.257 ! markus 1804: if (errno == ECONNRESET) {
! 1805: ssh_packet_clear_keys(ssh);
1.245 djm 1806: logdie("Connection reset by %s", remote_id);
1.257 ! markus 1807: }
1.213 djm 1808: /* FALLTHROUGH */
1809: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1810: case SSH_ERR_NO_MAC_ALG_MATCH:
1811: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1812: case SSH_ERR_NO_KEX_ALG_MATCH:
1813: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1814: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.257 ! markus 1815: ssh_packet_clear_keys(ssh);
1.245 djm 1816: logdie("Unable to negotiate with %s: %s. "
1817: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1818: ssh->kex->failed_choice);
1.212 djm 1819: }
1820: /* FALLTHROUGH */
1.205 djm 1821: default:
1.257 ! markus 1822: ssh_packet_clear_keys(ssh);
1.245 djm 1823: logdie("%s%sConnection %s %s: %s",
1.205 djm 1824: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 1825: ssh->state->server_side ? "from" : "to",
1.245 djm 1826: remote_id, ssh_err(r));
1.205 djm 1827: }
1.1 deraadt 1828: }
1829:
1.16 markus 1830: /*
1831: * Logs the error plus constructs and sends a disconnect packet, closes the
1832: * connection, and exits. This function never returns. The error message
1833: * should not contain a newline. The length of the formatted message must
1834: * not exceed 1024 bytes.
1835: */
1.2 provos 1836: void
1.201 markus 1837: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1838: {
1.245 djm 1839: char buf[1024], remote_id[512];
1.14 markus 1840: va_list args;
1841: static int disconnecting = 0;
1.201 markus 1842: int r;
1.97 deraadt 1843:
1.14 markus 1844: if (disconnecting) /* Guard against recursive invocations. */
1845: fatal("packet_disconnect called recursively.");
1846: disconnecting = 1;
1847:
1.16 markus 1848: /*
1849: * Format the message. Note that the caller must make sure the
1850: * message is of limited size.
1851: */
1.245 djm 1852: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1853: va_start(args, fmt);
1854: vsnprintf(buf, sizeof(buf), fmt, args);
1855: va_end(args);
1856:
1.99 markus 1857: /* Display the error locally */
1.245 djm 1858: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1859:
1.205 djm 1860: /*
1861: * Send the disconnect message to the other side, and wait
1862: * for it to get sent.
1863: */
1864: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1865: sshpkt_fatal(ssh, __func__, r);
1866:
1867: if ((r = ssh_packet_write_wait(ssh)) != 0)
1868: sshpkt_fatal(ssh, __func__, r);
1.14 markus 1869:
1870: /* Close the connection. */
1.201 markus 1871: ssh_packet_close(ssh);
1.112 markus 1872: cleanup_exit(255);
1.1 deraadt 1873: }
1874:
1.205 djm 1875: /*
1876: * Checks if there is any buffered output, and tries to write some of
1877: * the output.
1878: */
1879: int
1.201 markus 1880: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1881: {
1.201 markus 1882: struct session_state *state = ssh->state;
1883: int len = sshbuf_len(state->output);
1.222 markus 1884: int r;
1.97 deraadt 1885:
1.14 markus 1886: if (len > 0) {
1.222 markus 1887: len = write(state->connection_out,
1888: sshbuf_ptr(state->output), len);
1.156 djm 1889: if (len == -1) {
1890: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1891: return 0;
1892: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1893: }
1.222 markus 1894: if (len == 0)
1.205 djm 1895: return SSH_ERR_CONN_CLOSED;
1.201 markus 1896: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1897: return r;
1.14 markus 1898: }
1.205 djm 1899: return 0;
1.1 deraadt 1900: }
1901:
1.16 markus 1902: /*
1903: * Calls packet_write_poll repeatedly until all pending output data has been
1904: * written.
1905: */
1.205 djm 1906: int
1.201 markus 1907: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1908: {
1.56 millert 1909: fd_set *setp;
1.205 djm 1910: int ret, r, ms_remain = 0;
1.154 dtucker 1911: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1912: struct session_state *state = ssh->state;
1.56 millert 1913:
1.214 deraadt 1914: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1915: NFDBITS), sizeof(fd_mask));
1.201 markus 1916: if (setp == NULL)
1.205 djm 1917: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1918: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1919: free(setp);
1.215 djm 1920: return r;
1.216 gsoares 1921: }
1.201 markus 1922: while (ssh_packet_have_data_to_write(ssh)) {
1923: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1924: NFDBITS) * sizeof(fd_mask));
1.201 markus 1925: FD_SET(state->connection_out, setp);
1.154 dtucker 1926:
1.201 markus 1927: if (state->packet_timeout_ms > 0) {
1928: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1929: timeoutp = &timeout;
1930: }
1931: for (;;) {
1.201 markus 1932: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1933: ms_to_timeval(&timeout, ms_remain);
1934: gettimeofday(&start, NULL);
1935: }
1.201 markus 1936: if ((ret = select(state->connection_out + 1,
1.161 andreas 1937: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1938: break;
1.161 andreas 1939: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1940: break;
1.201 markus 1941: if (state->packet_timeout_ms == -1)
1.154 dtucker 1942: continue;
1943: ms_subtract_diff(&start, &ms_remain);
1944: if (ms_remain <= 0) {
1945: ret = 0;
1946: break;
1947: }
1948: }
1949: if (ret == 0) {
1.205 djm 1950: free(setp);
1951: return SSH_ERR_CONN_TIMEOUT;
1952: }
1953: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1954: free(setp);
1955: return r;
1.154 dtucker 1956: }
1.14 markus 1957: }
1.186 djm 1958: free(setp);
1.205 djm 1959: return 0;
1.1 deraadt 1960: }
1961:
1962: /* Returns true if there is buffered data to write to the connection. */
1963:
1.2 provos 1964: int
1.201 markus 1965: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 1966: {
1.201 markus 1967: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 1968: }
1969:
1970: /* Returns true if there is not too much data to write to the connection. */
1971:
1.2 provos 1972: int
1.201 markus 1973: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 1974: {
1.201 markus 1975: if (ssh->state->interactive_mode)
1976: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 1977: else
1.201 markus 1978: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 1979: }
1980:
1.201 markus 1981: void
1982: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 1983: {
1.201 markus 1984: if (!ssh_packet_connection_is_on_socket(ssh))
1.101 markus 1985: return;
1.201 markus 1986: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 1987: case AF_INET:
1988: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 1989: if (setsockopt(ssh->state->connection_in,
1.173 djm 1990: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
1991: error("setsockopt IP_TOS %d: %.100s:",
1992: tos, strerror(errno));
1993: break;
1994: case AF_INET6:
1995: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 1996: if (setsockopt(ssh->state->connection_in,
1.173 djm 1997: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
1998: error("setsockopt IPV6_TCLASS %d: %.100s:",
1999: tos, strerror(errno));
2000: break;
2001: }
1.101 markus 2002: }
2003:
1.1 deraadt 2004: /* Informs that the current session is interactive. Sets IP flags for that. */
2005:
1.2 provos 2006: void
1.201 markus 2007: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2008: {
1.201 markus 2009: struct session_state *state = ssh->state;
2010:
2011: if (state->set_interactive_called)
1.43 markus 2012: return;
1.201 markus 2013: state->set_interactive_called = 1;
1.1 deraadt 2014:
1.14 markus 2015: /* Record that we are in interactive mode. */
1.201 markus 2016: state->interactive_mode = interactive;
1.1 deraadt 2017:
1.19 markus 2018: /* Only set socket options if using a socket. */
1.201 markus 2019: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2020: return;
1.201 markus 2021: set_nodelay(state->connection_in);
2022: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2023: qos_bulk);
1.1 deraadt 2024: }
2025:
2026: /* Returns true if the current connection is interactive. */
2027:
1.2 provos 2028: int
1.201 markus 2029: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2030: {
1.201 markus 2031: return ssh->state->interactive_mode;
1.12 markus 2032: }
2033:
1.113 deraadt 2034: int
1.201 markus 2035: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2036: {
1.201 markus 2037: struct session_state *state = ssh->state;
2038:
2039: if (state->set_maxsize_called) {
1.106 itojun 2040: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2041: state->max_packet_size, s);
1.14 markus 2042: return -1;
2043: }
2044: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2045: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2046: return -1;
2047: }
1.201 markus 2048: state->set_maxsize_called = 1;
1.66 markus 2049: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2050: state->max_packet_size = s;
1.14 markus 2051: return s;
1.53 markus 2052: }
2053:
1.161 andreas 2054: int
1.201 markus 2055: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2056: {
1.201 markus 2057: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2058: }
2059:
2060: void
1.201 markus 2061: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2062: {
1.201 markus 2063: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2064: }
2065:
2066: u_int
1.201 markus 2067: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2068: {
1.201 markus 2069: return ssh->state->max_packet_size;
1.71 markus 2070: }
2071:
1.53 markus 2072: /*
2073: * 9.2. Ignored Data Message
1.61 markus 2074: *
1.53 markus 2075: * byte SSH_MSG_IGNORE
2076: * string data
1.61 markus 2077: *
1.53 markus 2078: * All implementations MUST understand (and ignore) this message at any
2079: * time (after receiving the protocol version). No implementation is
2080: * required to send them. This message can be used as an additional
2081: * protection measure against advanced traffic analysis techniques.
2082: */
1.54 markus 2083: void
1.201 markus 2084: ssh_packet_send_ignore(struct ssh *ssh, int nbytes)
1.54 markus 2085: {
1.115 avsm 2086: u_int32_t rnd = 0;
1.201 markus 2087: int r, i;
1.54 markus 2088:
1.249 djm 2089: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
1.201 markus 2090: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2091: fatal("%s: %s", __func__, ssh_err(r));
1.75 deraadt 2092: for (i = 0; i < nbytes; i++) {
1.53 markus 2093: if (i % 4 == 0)
1.115 avsm 2094: rnd = arc4random();
1.201 markus 2095: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2096: fatal("%s: %s", __func__, ssh_err(r));
1.115 avsm 2097: rnd >>= 8;
1.53 markus 2098: }
1.105 markus 2099: }
2100:
2101: void
1.244 dtucker 2102: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2103: {
1.244 dtucker 2104: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2105: (unsigned int)seconds);
1.201 markus 2106: ssh->state->rekey_limit = bytes;
2107: ssh->state->rekey_interval = seconds;
1.184 dtucker 2108: }
2109:
2110: time_t
1.201 markus 2111: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2112: {
2113: time_t seconds;
2114:
1.201 markus 2115: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2116: monotime();
1.185 dtucker 2117: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2118: }
2119:
2120: void
1.201 markus 2121: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2122: {
1.201 markus 2123: ssh->state->server_side = 1;
1.118 markus 2124: }
2125:
2126: void
1.201 markus 2127: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2128: {
1.201 markus 2129: ssh->state->after_authentication = 1;
1.161 andreas 2130: }
2131:
2132: void *
1.201 markus 2133: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2134: {
1.201 markus 2135: return (void *)ssh->state->input;
1.161 andreas 2136: }
2137:
2138: void *
1.201 markus 2139: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2140: {
1.201 markus 2141: return (void *)ssh->state->output;
1.166 andreas 2142: }
2143:
1.196 markus 2144: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2145: static int
2146: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2147: {
1.239 djm 2148: int r;
1.196 markus 2149:
2150: debug("%s: called", __func__);
2151: /* This was set in net child, but is not visible in user child */
1.201 markus 2152: ssh->state->after_authentication = 1;
2153: ssh->state->rekeying = 0;
1.239 djm 2154: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2155: return r;
1.201 markus 2156: return 0;
2157: }
2158:
2159: /* Packet state (de-)serialization for privsep */
2160:
2161: /* turn kex into a blob for packet state serialization */
2162: static int
2163: kex_to_blob(struct sshbuf *m, struct kex *kex)
2164: {
2165: int r;
2166:
2167: if ((r = sshbuf_put_string(m, kex->session_id,
2168: kex->session_id_len)) != 0 ||
2169: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2170: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2171: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2172: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2173: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2174: (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2175: (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2176: (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2177: return r;
2178: return 0;
2179: }
2180:
2181: /* turn key exchange results into a blob for packet state serialization */
2182: static int
2183: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2184: {
2185: struct sshbuf *b;
2186: struct sshcipher_ctx *cc;
2187: struct sshcomp *comp;
2188: struct sshenc *enc;
2189: struct sshmac *mac;
2190: struct newkeys *newkey;
2191: int r;
2192:
2193: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2194: return SSH_ERR_INTERNAL_ERROR;
2195: enc = &newkey->enc;
2196: mac = &newkey->mac;
2197: comp = &newkey->comp;
1.235 djm 2198: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2199: ssh->state->receive_context;
1.201 markus 2200: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2201: return r;
2202: if ((b = sshbuf_new()) == NULL)
2203: return SSH_ERR_ALLOC_FAIL;
2204: /* The cipher struct is constant and shared, you export pointer */
2205: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2206: (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2207: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2208: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2209: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2210: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2211: goto out;
2212: if (cipher_authlen(enc->cipher) == 0) {
2213: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2214: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2215: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2216: goto out;
2217: }
2218: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2219: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2220: goto out;
2221: r = sshbuf_put_stringb(m, b);
2222: out:
1.221 mmcc 2223: sshbuf_free(b);
1.201 markus 2224: return r;
2225: }
2226:
2227: /* serialize packet state into a blob */
2228: int
2229: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2230: {
2231: struct session_state *state = ssh->state;
1.249 djm 2232: int r;
1.201 markus 2233:
1.249 djm 2234: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2235: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2236: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2237: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2238: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2239: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2240: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2241: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2242: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2243: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2244: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2245: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2246: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2247: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2248: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 2249: return r;
1.201 markus 2250:
2251: return 0;
2252: }
2253:
2254: /* restore key exchange results from blob for packet state de-serialization */
2255: static int
2256: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2257: {
2258: struct sshbuf *b = NULL;
2259: struct sshcomp *comp;
2260: struct sshenc *enc;
2261: struct sshmac *mac;
2262: struct newkeys *newkey = NULL;
2263: size_t keylen, ivlen, maclen;
2264: int r;
2265:
2266: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2267: r = SSH_ERR_ALLOC_FAIL;
2268: goto out;
2269: }
2270: if ((r = sshbuf_froms(m, &b)) != 0)
2271: goto out;
2272: #ifdef DEBUG_PK
2273: sshbuf_dump(b, stderr);
2274: #endif
2275: enc = &newkey->enc;
2276: mac = &newkey->mac;
2277: comp = &newkey->comp;
2278:
2279: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2280: (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2281: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2282: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2283: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2284: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2285: goto out;
2286: if (cipher_authlen(enc->cipher) == 0) {
2287: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2288: goto out;
2289: if ((r = mac_setup(mac, mac->name)) != 0)
2290: goto out;
2291: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2292: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2293: goto out;
2294: if (maclen > mac->key_len) {
2295: r = SSH_ERR_INVALID_FORMAT;
2296: goto out;
2297: }
2298: mac->key_len = maclen;
2299: }
2300: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2301: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2302: goto out;
2303: if (enc->name == NULL ||
2304: cipher_by_name(enc->name) != enc->cipher) {
2305: r = SSH_ERR_INVALID_FORMAT;
2306: goto out;
2307: }
2308: if (sshbuf_len(b) != 0) {
2309: r = SSH_ERR_INVALID_FORMAT;
2310: goto out;
2311: }
2312: enc->key_len = keylen;
2313: enc->iv_len = ivlen;
2314: ssh->kex->newkeys[mode] = newkey;
2315: newkey = NULL;
2316: r = 0;
2317: out:
1.219 mmcc 2318: free(newkey);
1.221 mmcc 2319: sshbuf_free(b);
1.201 markus 2320: return r;
2321: }
2322:
2323: /* restore kex from blob for packet state de-serialization */
2324: static int
2325: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2326: {
2327: struct kex *kex;
2328: int r;
2329:
2330: if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2331: (kex->my = sshbuf_new()) == NULL ||
2332: (kex->peer = sshbuf_new()) == NULL) {
2333: r = SSH_ERR_ALLOC_FAIL;
2334: goto out;
2335: }
2336: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2337: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2338: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2339: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2340: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2341: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2342: (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2343: (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2344: (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2345: goto out;
2346: kex->server = 1;
2347: kex->done = 1;
2348: r = 0;
2349: out:
2350: if (r != 0 || kexp == NULL) {
2351: if (kex != NULL) {
1.221 mmcc 2352: sshbuf_free(kex->my);
2353: sshbuf_free(kex->peer);
1.201 markus 2354: free(kex);
2355: }
2356: if (kexp != NULL)
2357: *kexp = NULL;
2358: } else {
2359: *kexp = kex;
2360: }
2361: return r;
2362: }
2363:
2364: /*
2365: * Restore packet state from content of blob 'm' (de-serialization).
2366: * Note that 'm' will be partially consumed on parsing or any other errors.
2367: */
2368: int
2369: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2370: {
2371: struct session_state *state = ssh->state;
1.254 djm 2372: const u_char *input, *output;
2373: size_t ilen, olen;
1.201 markus 2374: int r;
2375:
1.249 djm 2376: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2377: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2378: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2379: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2380: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2381: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2382: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2383: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2384: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2385: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2386: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2387: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2388: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2389: return r;
2390: /*
2391: * We set the time here so that in post-auth privsep slave we
2392: * count from the completion of the authentication.
2393: */
2394: state->rekey_time = monotime();
2395: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2396: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2397: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2398: return r;
1.201 markus 2399:
1.239 djm 2400: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2401: return r;
2402:
2403: sshbuf_reset(state->input);
2404: sshbuf_reset(state->output);
2405: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2406: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2407: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2408: (r = sshbuf_put(state->output, output, olen)) != 0)
2409: return r;
2410:
2411: if (sshbuf_len(m))
2412: return SSH_ERR_INVALID_FORMAT;
2413: debug3("%s: done", __func__);
2414: return 0;
2415: }
2416:
2417: /* NEW API */
2418:
2419: /* put data to the outgoing packet */
2420:
2421: int
2422: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2423: {
2424: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2425: }
2426:
2427: int
2428: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2429: {
2430: return sshbuf_putb(ssh->state->outgoing_packet, b);
2431: }
2432:
2433: int
2434: sshpkt_put_u8(struct ssh *ssh, u_char val)
2435: {
2436: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2437: }
2438:
2439: int
2440: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2441: {
2442: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2443: }
2444:
2445: int
2446: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2447: {
2448: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2449: }
2450:
2451: int
2452: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2453: {
2454: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2455: }
2456:
2457: int
2458: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2459: {
2460: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2461: }
2462:
2463: int
2464: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2465: {
2466: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2467: }
2468:
1.211 djm 2469: #ifdef WITH_OPENSSL
1.201 markus 2470: int
2471: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2472: {
2473: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2474: }
2475:
2476:
2477: int
2478: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2479: {
2480: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2481: }
1.211 djm 2482: #endif /* WITH_OPENSSL */
1.201 markus 2483:
2484: /* fetch data from the incoming packet */
2485:
2486: int
2487: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2488: {
2489: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2490: }
2491:
2492: int
2493: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2494: {
2495: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2496: }
2497:
2498: int
2499: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2500: {
2501: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2502: }
2503:
2504: int
2505: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2506: {
2507: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2508: }
2509:
2510: int
2511: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2512: {
2513: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2514: }
2515:
2516: int
2517: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2518: {
2519: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2520: }
2521:
2522: int
2523: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2524: {
2525: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2526: }
2527:
1.211 djm 2528: #ifdef WITH_OPENSSL
1.201 markus 2529: int
2530: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2531: {
2532: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2533: }
2534:
2535:
2536: int
2537: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2538: {
2539: return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2540: }
1.211 djm 2541: #endif /* WITH_OPENSSL */
1.201 markus 2542:
2543: int
2544: sshpkt_get_end(struct ssh *ssh)
2545: {
2546: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2547: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2548: return 0;
2549: }
2550:
2551: const u_char *
2552: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2553: {
2554: if (lenp != NULL)
2555: *lenp = sshbuf_len(ssh->state->incoming_packet);
2556: return sshbuf_ptr(ssh->state->incoming_packet);
2557: }
2558:
2559: /* start a new packet */
2560:
2561: int
2562: sshpkt_start(struct ssh *ssh, u_char type)
2563: {
1.249 djm 2564: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2565:
2566: DBG(debug("packet_start[%d]", type));
1.249 djm 2567: memset(buf, 0, sizeof(buf));
2568: buf[sizeof(buf) - 1] = type;
1.201 markus 2569: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2570: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2571: }
2572:
1.242 markus 2573: static int
2574: ssh_packet_send_mux(struct ssh *ssh)
2575: {
2576: struct session_state *state = ssh->state;
2577: u_char type, *cp;
2578: size_t len;
2579: int r;
2580:
2581: if (ssh->kex)
2582: return SSH_ERR_INTERNAL_ERROR;
2583: len = sshbuf_len(state->outgoing_packet);
2584: if (len < 6)
2585: return SSH_ERR_INTERNAL_ERROR;
2586: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2587: type = cp[5];
2588: if (ssh_packet_log_type(type))
2589: debug3("%s: type %u", __func__, type);
2590: /* drop everything, but the connection protocol */
2591: if (type >= SSH2_MSG_CONNECTION_MIN &&
2592: type <= SSH2_MSG_CONNECTION_MAX) {
2593: POKE_U32(cp, len - 4);
2594: if ((r = sshbuf_putb(state->output,
2595: state->outgoing_packet)) != 0)
2596: return r;
2597: /* sshbuf_dump(state->output, stderr); */
2598: }
2599: sshbuf_reset(state->outgoing_packet);
2600: return 0;
2601: }
2602:
1.201 markus 2603: /* send it */
2604:
2605: int
2606: sshpkt_send(struct ssh *ssh)
2607: {
1.242 markus 2608: if (ssh->state && ssh->state->mux)
2609: return ssh_packet_send_mux(ssh);
1.249 djm 2610: return ssh_packet_send2(ssh);
1.201 markus 2611: }
2612:
2613: int
2614: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2615: {
2616: char buf[1024];
2617: va_list args;
2618: int r;
2619:
2620: va_start(args, fmt);
2621: vsnprintf(buf, sizeof(buf), fmt, args);
2622: va_end(args);
2623:
1.249 djm 2624: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2625: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2626: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2627: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2628: (r = sshpkt_send(ssh)) != 0)
2629: return r;
1.201 markus 2630: return 0;
2631: }
2632:
2633: /* roundup current message to pad bytes */
2634: int
2635: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2636: {
2637: ssh->state->extra_pad = pad;
2638: return 0;
1.1 deraadt 2639: }
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