Annotation of src/usr.bin/ssh/packet.c, Revision 1.229
1.229 ! djm 1: /* $OpenBSD: packet.c,v 1.228 2016/02/08 10:57:07 djm Exp $ */
1.1 deraadt 2: /*
1.15 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.35 deraadt 6: * This file contains code implementing the packet protocol and communication
7: * with the other side. This same code is used both on client and server side.
1.29 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
1.29 markus 14: *
1.25 markus 15: *
16: * SSH2 packet format added by Markus Friedl.
1.69 markus 17: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.25 markus 18: *
1.35 deraadt 19: * Redistribution and use in source and binary forms, with or without
20: * modification, are permitted provided that the following conditions
21: * are met:
22: * 1. Redistributions of source code must retain the above copyright
23: * notice, this list of conditions and the following disclaimer.
24: * 2. Redistributions in binary form must reproduce the above copyright
25: * notice, this list of conditions and the following disclaimer in the
26: * documentation and/or other materials provided with the distribution.
27: *
28: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15 deraadt 38: */
1.1 deraadt 39:
1.203 deraadt 40: #include <sys/param.h> /* MIN roundup */
1.142 deraadt 41: #include <sys/types.h>
1.105 markus 42: #include <sys/queue.h>
1.132 stevesk 43: #include <sys/socket.h>
1.138 stevesk 44: #include <sys/time.h>
1.132 stevesk 45: #include <netinet/in.h>
1.121 stevesk 46: #include <netinet/ip.h>
1.134 stevesk 47:
1.135 stevesk 48: #include <errno.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"
1.9 dugsong 65: #include "deattack.h"
1.25 markus 66: #include "compat.h"
1.45 markus 67: #include "ssh1.h"
1.25 markus 68: #include "ssh2.h"
1.37 markus 69: #include "cipher.h"
1.201 markus 70: #include "sshkey.h"
1.25 markus 71: #include "kex.h"
1.200 markus 72: #include "digest.h"
1.50 markus 73: #include "mac.h"
1.46 markus 74: #include "log.h"
75: #include "canohost.h"
1.87 stevesk 76: #include "misc.h"
1.198 millert 77: #include "channels.h"
1.95 markus 78: #include "ssh.h"
1.201 markus 79: #include "packet.h"
1.197 djm 80: #include "ssherr.h"
1.201 markus 81: #include "sshbuf.h"
1.25 markus 82:
83: #ifdef PACKET_DEBUG
84: #define DBG(x) x
85: #else
86: #define DBG(x)
87: #endif
88:
1.159 markus 89: #define PACKET_MAX_SIZE (256 * 1024)
90:
1.161 andreas 91: struct packet_state {
92: u_int32_t seqnr;
93: u_int32_t packets;
94: u_int64_t blocks;
95: u_int64_t bytes;
96: };
97:
98: struct packet {
99: TAILQ_ENTRY(packet) next;
100: u_char type;
1.201 markus 101: struct sshbuf *payload;
1.161 andreas 102: };
103:
104: struct session_state {
105: /*
106: * This variable contains the file descriptors used for
107: * communicating with the other side. connection_in is used for
108: * reading; connection_out for writing. These can be the same
109: * descriptor, in which case it is assumed to be a socket.
110: */
111: int connection_in;
112: int connection_out;
113:
114: /* Protocol flags for the remote side. */
115: u_int remote_protocol_flags;
1.1 deraadt 116:
1.161 andreas 117: /* Encryption context for receiving data. Only used for decryption. */
1.201 markus 118: struct sshcipher_ctx receive_context;
1.1 deraadt 119:
1.161 andreas 120: /* Encryption context for sending data. Only used for encryption. */
1.201 markus 121: struct sshcipher_ctx send_context;
1.14 markus 122:
1.161 andreas 123: /* Buffer for raw input data from the socket. */
1.201 markus 124: struct sshbuf *input;
1.1 deraadt 125:
1.161 andreas 126: /* Buffer for raw output data going to the socket. */
1.201 markus 127: struct sshbuf *output;
1.1 deraadt 128:
1.161 andreas 129: /* Buffer for the partial outgoing packet being constructed. */
1.201 markus 130: struct sshbuf *outgoing_packet;
1.1 deraadt 131:
1.161 andreas 132: /* Buffer for the incoming packet currently being processed. */
1.201 markus 133: struct sshbuf *incoming_packet;
1.1 deraadt 134:
1.161 andreas 135: /* Scratch buffer for packet compression/decompression. */
1.201 markus 136: struct sshbuf *compression_buffer;
137:
138: /* Incoming/outgoing compression dictionaries */
139: z_stream compression_in_stream;
140: z_stream compression_out_stream;
141: int compression_in_started;
142: int compression_out_started;
143: int compression_in_failures;
144: int compression_out_failures;
1.1 deraadt 145:
1.161 andreas 146: /*
147: * Flag indicating whether packet compression/decompression is
148: * enabled.
149: */
150: int packet_compression;
1.1 deraadt 151:
1.161 andreas 152: /* default maximum packet size */
153: u_int max_packet_size;
1.1 deraadt 154:
1.161 andreas 155: /* Flag indicating whether this module has been initialized. */
156: int initialized;
1.12 markus 157:
1.161 andreas 158: /* Set to true if the connection is interactive. */
159: int interactive_mode;
1.1 deraadt 160:
1.161 andreas 161: /* Set to true if we are the server side. */
162: int server_side;
1.1 deraadt 163:
1.161 andreas 164: /* Set to true if we are authenticated. */
165: int after_authentication;
1.118 markus 166:
1.161 andreas 167: int keep_alive_timeouts;
1.118 markus 168:
1.161 andreas 169: /* The maximum time that we will wait to send or receive a packet */
170: int packet_timeout_ms;
1.151 dtucker 171:
1.161 andreas 172: /* Session key information for Encryption and MAC */
1.201 markus 173: struct newkeys *newkeys[MODE_MAX];
1.161 andreas 174: struct packet_state p_read, p_send;
1.154 dtucker 175:
1.184 dtucker 176: /* Volume-based rekeying */
1.224 dtucker 177: u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
1.105 markus 178:
1.184 dtucker 179: /* Time-based rekeying */
1.208 markus 180: u_int32_t rekey_interval; /* how often in seconds */
1.184 dtucker 181: time_t rekey_time; /* time of last rekeying */
182:
1.161 andreas 183: /* Session key for protocol v1 */
184: u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
185: u_int ssh1_keylen;
1.25 markus 186:
1.161 andreas 187: /* roundup current message to extra_pad bytes */
188: u_char extra_pad;
1.95 markus 189:
1.161 andreas 190: /* XXX discard incoming data after MAC error */
191: u_int packet_discard;
1.201 markus 192: struct sshmac *packet_discard_mac;
1.71 markus 193:
1.161 andreas 194: /* Used in packet_read_poll2() */
195: u_int packlen;
1.159 markus 196:
1.165 andreas 197: /* Used in packet_send2 */
198: int rekeying;
199:
200: /* Used in packet_set_interactive */
201: int set_interactive_called;
202:
203: /* Used in packet_set_maxsize */
204: int set_maxsize_called;
205:
1.201 markus 206: /* One-off warning about weak ciphers */
207: int cipher_warning_done;
208:
209: /* SSH1 CRC compensation attack detector */
210: struct deattack_ctx deattack;
211:
1.161 andreas 212: TAILQ_HEAD(, packet) outgoing;
1.105 markus 213: };
1.161 andreas 214:
1.201 markus 215: struct ssh *
216: ssh_alloc_session_state(void)
1.161 andreas 217: {
1.201 markus 218: struct ssh *ssh = NULL;
219: struct session_state *state = NULL;
1.161 andreas 220:
1.201 markus 221: if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
222: (state = calloc(1, sizeof(*state))) == NULL ||
223: (state->input = sshbuf_new()) == NULL ||
224: (state->output = sshbuf_new()) == NULL ||
225: (state->outgoing_packet = sshbuf_new()) == NULL ||
226: (state->incoming_packet = sshbuf_new()) == NULL)
227: goto fail;
228: TAILQ_INIT(&state->outgoing);
1.202 markus 229: TAILQ_INIT(&ssh->private_keys);
230: TAILQ_INIT(&ssh->public_keys);
1.201 markus 231: state->connection_in = -1;
232: state->connection_out = -1;
233: state->max_packet_size = 32768;
234: state->packet_timeout_ms = -1;
235: state->p_send.packets = state->p_read.packets = 0;
236: state->initialized = 1;
237: /*
238: * ssh_packet_send2() needs to queue packets until
239: * we've done the initial key exchange.
240: */
241: state->rekeying = 1;
242: ssh->state = state;
243: return ssh;
244: fail:
245: if (state) {
246: sshbuf_free(state->input);
247: sshbuf_free(state->output);
248: sshbuf_free(state->incoming_packet);
249: sshbuf_free(state->outgoing_packet);
250: free(state);
251: }
252: free(ssh);
253: return NULL;
1.161 andreas 254: }
1.105 markus 255:
1.228 djm 256: /* Returns nonzero if rekeying is in progress */
257: int
258: ssh_packet_is_rekeying(struct ssh *ssh)
259: {
1.229 ! djm 260: return compat20 &&
! 261: (ssh->state->rekeying || (ssh->kex != NULL && ssh->kex->done == 0));
1.228 djm 262: }
263:
1.16 markus 264: /*
265: * Sets the descriptors used for communication. Disables encryption until
266: * packet_set_encryption_key is called.
267: */
1.201 markus 268: struct ssh *
269: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1 deraadt 270: {
1.201 markus 271: struct session_state *state;
272: const struct sshcipher *none = cipher_by_name("none");
1.197 djm 273: int r;
1.97 deraadt 274:
1.205 djm 275: if (none == NULL) {
276: error("%s: cannot load cipher 'none'", __func__);
277: return NULL;
278: }
1.201 markus 279: if (ssh == NULL)
280: ssh = ssh_alloc_session_state();
1.205 djm 281: if (ssh == NULL) {
282: error("%s: cound not allocate state", __func__);
283: return NULL;
284: }
1.201 markus 285: state = ssh->state;
286: state->connection_in = fd_in;
287: state->connection_out = fd_out;
288: if ((r = cipher_init(&state->send_context, none,
1.197 djm 289: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201 markus 290: (r = cipher_init(&state->receive_context, none,
1.205 djm 291: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
292: error("%s: cipher_init failed: %s", __func__, ssh_err(r));
1.209 jsg 293: free(ssh);
1.205 djm 294: return NULL;
295: }
1.201 markus 296: state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
297: deattack_init(&state->deattack);
1.207 djm 298: /*
299: * Cache the IP address of the remote connection for use in error
300: * messages that might be generated after the connection has closed.
301: */
302: (void)ssh_remote_ipaddr(ssh);
1.201 markus 303: return ssh;
1.1 deraadt 304: }
305:
1.154 dtucker 306: void
1.201 markus 307: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 308: {
1.201 markus 309: struct session_state *state = ssh->state;
310:
1.174 djm 311: if (timeout <= 0 || count <= 0) {
1.201 markus 312: state->packet_timeout_ms = -1;
1.154 dtucker 313: return;
314: }
315: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 316: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 317: else
1.201 markus 318: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 319: }
320:
1.201 markus 321: int
322: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 323: {
1.201 markus 324: struct session_state *state = ssh->state;
325: int r;
326:
327: if (state->packet_discard_mac) {
1.159 markus 328: char buf[1024];
1.201 markus 329:
1.159 markus 330: memset(buf, 'a', sizeof(buf));
1.201 markus 331: while (sshbuf_len(state->incoming_packet) <
1.161 andreas 332: PACKET_MAX_SIZE)
1.201 markus 333: if ((r = sshbuf_put(state->incoming_packet, buf,
334: sizeof(buf))) != 0)
335: return r;
336: (void) mac_compute(state->packet_discard_mac,
337: state->p_read.seqnr,
338: sshbuf_ptr(state->incoming_packet), PACKET_MAX_SIZE,
339: NULL, 0);
1.159 markus 340: }
1.220 djm 341: logit("Finished discarding for %.200s port %d",
342: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 343: return SSH_ERR_MAC_INVALID;
1.159 markus 344: }
345:
1.201 markus 346: static int
347: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
348: struct sshmac *mac, u_int packet_length, u_int discard)
1.159 markus 349: {
1.201 markus 350: struct session_state *state = ssh->state;
351: int r;
352:
353: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
354: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
355: return r;
356: return SSH_ERR_MAC_INVALID;
357: }
1.159 markus 358: if (packet_length != PACKET_MAX_SIZE && mac && mac->enabled)
1.201 markus 359: state->packet_discard_mac = mac;
360: if (sshbuf_len(state->input) >= discard &&
361: (r = ssh_packet_stop_discard(ssh)) != 0)
362: return r;
363: state->packet_discard = discard - sshbuf_len(state->input);
364: return 0;
1.159 markus 365: }
366:
1.19 markus 367: /* Returns 1 if remote host is connected via socket, 0 if not. */
368:
369: int
1.201 markus 370: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 371: {
1.201 markus 372: struct session_state *state = ssh->state;
1.19 markus 373: struct sockaddr_storage from, to;
374: socklen_t fromlen, tolen;
375:
376: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 377: if (state->connection_in == state->connection_out)
1.19 markus 378: return 1;
379: fromlen = sizeof(from);
380: memset(&from, 0, sizeof(from));
1.201 markus 381: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.161 andreas 382: &fromlen) < 0)
1.19 markus 383: return 0;
384: tolen = sizeof(to);
385: memset(&to, 0, sizeof(to));
1.201 markus 386: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.161 andreas 387: &tolen) < 0)
1.19 markus 388: return 0;
389: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
390: return 0;
391: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
392: return 0;
393: return 1;
394: }
395:
1.91 markus 396: void
1.201 markus 397: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 398: {
1.201 markus 399: if (ibytes)
400: *ibytes = ssh->state->p_read.bytes;
401: if (obytes)
402: *obytes = ssh->state->p_send.bytes;
1.91 markus 403: }
1.125 deraadt 404:
1.91 markus 405: int
1.201 markus 406: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 407: {
408: struct sockaddr_storage to;
1.21 deraadt 409: socklen_t tolen = sizeof(to);
1.19 markus 410:
411: memset(&to, 0, sizeof(to));
1.201 markus 412: if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
1.161 andreas 413: &tolen) < 0)
1.19 markus 414: return 0;
1.173 djm 415: return to.ss_family;
1.19 markus 416: }
417:
1.1 deraadt 418: /* Sets the connection into non-blocking mode. */
419:
1.2 provos 420: void
1.201 markus 421: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 422: {
1.14 markus 423: /* Set the socket into non-blocking mode. */
1.201 markus 424: set_nonblock(ssh->state->connection_in);
1.14 markus 425:
1.201 markus 426: if (ssh->state->connection_out != ssh->state->connection_in)
427: set_nonblock(ssh->state->connection_out);
1.1 deraadt 428: }
429:
430: /* Returns the socket used for reading. */
431:
1.2 provos 432: int
1.201 markus 433: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 434: {
1.201 markus 435: return ssh->state->connection_in;
1.1 deraadt 436: }
437:
438: /* Returns the descriptor used for writing. */
439:
1.2 provos 440: int
1.201 markus 441: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 442: {
1.201 markus 443: return ssh->state->connection_out;
444: }
445:
446: /*
447: * Returns the IP-address of the remote host as a string. The returned
448: * string must not be freed.
449: */
450:
451: const char *
452: ssh_remote_ipaddr(struct ssh *ssh)
453: {
1.220 djm 454: const int sock = ssh->state->connection_in;
455:
1.201 markus 456: /* Check whether we have cached the ipaddr. */
1.220 djm 457: if (ssh->remote_ipaddr == NULL) {
458: if (ssh_packet_connection_is_on_socket(ssh)) {
459: ssh->remote_ipaddr = get_peer_ipaddr(sock);
460: ssh->remote_port = get_sock_port(sock, 0);
461: } else {
462: ssh->remote_ipaddr = strdup("UNKNOWN");
463: ssh->remote_port = 0;
464: }
465: }
1.201 markus 466: return ssh->remote_ipaddr;
1.1 deraadt 467: }
468:
1.220 djm 469: /* Returns the port number of the remote host. */
470:
471: int
472: ssh_remote_port(struct ssh *ssh)
473: {
474: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
475: return ssh->remote_port;
476: }
477:
1.1 deraadt 478: /* Closes the connection and clears and frees internal data structures. */
479:
1.2 provos 480: void
1.201 markus 481: ssh_packet_close(struct ssh *ssh)
1.1 deraadt 482: {
1.201 markus 483: struct session_state *state = ssh->state;
484: int r;
485: u_int mode;
486:
487: if (!state->initialized)
1.14 markus 488: return;
1.201 markus 489: state->initialized = 0;
490: if (state->connection_in == state->connection_out) {
491: shutdown(state->connection_out, SHUT_RDWR);
492: close(state->connection_out);
1.14 markus 493: } else {
1.201 markus 494: close(state->connection_in);
495: close(state->connection_out);
1.14 markus 496: }
1.201 markus 497: sshbuf_free(state->input);
498: sshbuf_free(state->output);
499: sshbuf_free(state->outgoing_packet);
500: sshbuf_free(state->incoming_packet);
501: for (mode = 0; mode < MODE_MAX; mode++)
502: kex_free_newkeys(state->newkeys[mode]);
503: if (state->compression_buffer) {
504: sshbuf_free(state->compression_buffer);
505: if (state->compression_out_started) {
506: z_streamp stream = &state->compression_out_stream;
507: debug("compress outgoing: "
508: "raw data %llu, compressed %llu, factor %.2f",
509: (unsigned long long)stream->total_in,
510: (unsigned long long)stream->total_out,
511: stream->total_in == 0 ? 0.0 :
512: (double) stream->total_out / stream->total_in);
513: if (state->compression_out_failures == 0)
514: deflateEnd(stream);
515: }
516: if (state->compression_in_started) {
517: z_streamp stream = &state->compression_out_stream;
518: debug("compress incoming: "
519: "raw data %llu, compressed %llu, factor %.2f",
520: (unsigned long long)stream->total_out,
521: (unsigned long long)stream->total_in,
522: stream->total_out == 0 ? 0.0 :
523: (double) stream->total_in / stream->total_out);
524: if (state->compression_in_failures == 0)
525: inflateEnd(stream);
526: }
1.14 markus 527: }
1.201 markus 528: if ((r = cipher_cleanup(&state->send_context)) != 0)
529: error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r));
530: if ((r = cipher_cleanup(&state->receive_context)) != 0)
531: error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r));
1.219 mmcc 532: free(ssh->remote_ipaddr);
533: ssh->remote_ipaddr = NULL;
1.201 markus 534: free(ssh->state);
535: ssh->state = NULL;
1.1 deraadt 536: }
537:
538: /* Sets remote side protocol flags. */
539:
1.2 provos 540: void
1.201 markus 541: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 542: {
1.201 markus 543: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 544: }
545:
546: /* Returns the remote protocol flags set earlier by the above function. */
547:
1.40 markus 548: u_int
1.201 markus 549: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 550: {
1.201 markus 551: return ssh->state->remote_protocol_flags;
1.1 deraadt 552: }
553:
1.16 markus 554: /*
555: * Starts packet compression from the next packet on in both directions.
556: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
557: */
1.1 deraadt 558:
1.201 markus 559: static int
560: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 561: {
1.201 markus 562: if (!ssh->state->compression_buffer &&
563: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
564: return SSH_ERR_ALLOC_FAIL;
565: return 0;
1.60 markus 566: }
567:
1.201 markus 568: static int
569: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 570: {
1.201 markus 571: if (level < 1 || level > 9)
572: return SSH_ERR_INVALID_ARGUMENT;
573: debug("Enabling compression at level %d.", level);
574: if (ssh->state->compression_out_started == 1)
575: deflateEnd(&ssh->state->compression_out_stream);
576: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
577: case Z_OK:
578: ssh->state->compression_out_started = 1;
579: break;
580: case Z_MEM_ERROR:
581: return SSH_ERR_ALLOC_FAIL;
582: default:
583: return SSH_ERR_INTERNAL_ERROR;
584: }
585: return 0;
1.1 deraadt 586: }
587:
1.201 markus 588: static int
589: start_compression_in(struct ssh *ssh)
590: {
591: if (ssh->state->compression_in_started == 1)
592: inflateEnd(&ssh->state->compression_in_stream);
593: switch (inflateInit(&ssh->state->compression_in_stream)) {
594: case Z_OK:
595: ssh->state->compression_in_started = 1;
596: break;
597: case Z_MEM_ERROR:
598: return SSH_ERR_ALLOC_FAIL;
599: default:
600: return SSH_ERR_INTERNAL_ERROR;
601: }
602: return 0;
603: }
1.95 markus 604:
1.201 markus 605: int
606: ssh_packet_start_compression(struct ssh *ssh, int level)
1.1 deraadt 607: {
1.197 djm 608: int r;
1.97 deraadt 609:
1.201 markus 610: if (ssh->state->packet_compression && !compat20)
611: return SSH_ERR_INTERNAL_ERROR;
612: ssh->state->packet_compression = 1;
613: if ((r = ssh_packet_init_compression(ssh)) != 0 ||
614: (r = start_compression_in(ssh)) != 0 ||
615: (r = start_compression_out(ssh, level)) != 0)
616: return r;
617: return 0;
1.95 markus 618: }
619:
1.201 markus 620: /* XXX remove need for separate compression buffer */
621: static int
622: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 623: {
1.201 markus 624: u_char buf[4096];
625: int r, status;
626:
627: if (ssh->state->compression_out_started != 1)
628: return SSH_ERR_INTERNAL_ERROR;
629:
630: /* This case is not handled below. */
631: if (sshbuf_len(in) == 0)
632: return 0;
633:
634: /* Input is the contents of the input buffer. */
635: if ((ssh->state->compression_out_stream.next_in =
636: sshbuf_mutable_ptr(in)) == NULL)
637: return SSH_ERR_INTERNAL_ERROR;
638: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
639:
640: /* Loop compressing until deflate() returns with avail_out != 0. */
641: do {
642: /* Set up fixed-size output buffer. */
643: ssh->state->compression_out_stream.next_out = buf;
644: ssh->state->compression_out_stream.avail_out = sizeof(buf);
645:
646: /* Compress as much data into the buffer as possible. */
647: status = deflate(&ssh->state->compression_out_stream,
648: Z_PARTIAL_FLUSH);
649: switch (status) {
650: case Z_MEM_ERROR:
651: return SSH_ERR_ALLOC_FAIL;
652: case Z_OK:
653: /* Append compressed data to output_buffer. */
654: if ((r = sshbuf_put(out, buf, sizeof(buf) -
655: ssh->state->compression_out_stream.avail_out)) != 0)
656: return r;
657: break;
658: case Z_STREAM_ERROR:
659: default:
660: ssh->state->compression_out_failures++;
661: return SSH_ERR_INVALID_FORMAT;
662: }
663: } while (ssh->state->compression_out_stream.avail_out == 0);
664: return 0;
1.1 deraadt 665: }
666:
1.201 markus 667: static int
668: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 669: {
1.201 markus 670: u_char buf[4096];
671: int r, status;
1.1 deraadt 672:
1.201 markus 673: if (ssh->state->compression_in_started != 1)
674: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 675:
1.201 markus 676: if ((ssh->state->compression_in_stream.next_in =
677: sshbuf_mutable_ptr(in)) == NULL)
678: return SSH_ERR_INTERNAL_ERROR;
679: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 680:
1.201 markus 681: for (;;) {
682: /* Set up fixed-size output buffer. */
683: ssh->state->compression_in_stream.next_out = buf;
684: ssh->state->compression_in_stream.avail_out = sizeof(buf);
685:
686: status = inflate(&ssh->state->compression_in_stream,
687: Z_PARTIAL_FLUSH);
688: switch (status) {
689: case Z_OK:
690: if ((r = sshbuf_put(out, buf, sizeof(buf) -
691: ssh->state->compression_in_stream.avail_out)) != 0)
692: return r;
693: break;
694: case Z_BUF_ERROR:
695: /*
696: * Comments in zlib.h say that we should keep calling
697: * inflate() until we get an error. This appears to
698: * be the error that we get.
699: */
700: return 0;
701: case Z_DATA_ERROR:
702: return SSH_ERR_INVALID_FORMAT;
703: case Z_MEM_ERROR:
704: return SSH_ERR_ALLOC_FAIL;
705: case Z_STREAM_ERROR:
706: default:
707: ssh->state->compression_in_failures++;
708: return SSH_ERR_INTERNAL_ERROR;
709: }
710: }
711: /* NOTREACHED */
1.1 deraadt 712: }
1.125 deraadt 713:
1.201 markus 714: /* Serialise compression state into a blob for privsep */
715: static int
716: ssh_packet_get_compress_state(struct sshbuf *m, struct ssh *ssh)
1.1 deraadt 717: {
1.201 markus 718: struct session_state *state = ssh->state;
719: struct sshbuf *b;
720: int r;
721:
722: if ((b = sshbuf_new()) == NULL)
723: return SSH_ERR_ALLOC_FAIL;
724: if (state->compression_in_started) {
725: if ((r = sshbuf_put_string(b, &state->compression_in_stream,
726: sizeof(state->compression_in_stream))) != 0)
727: goto out;
728: } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0)
729: goto out;
730: if (state->compression_out_started) {
731: if ((r = sshbuf_put_string(b, &state->compression_out_stream,
732: sizeof(state->compression_out_stream))) != 0)
733: goto out;
734: } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0)
735: goto out;
736: r = sshbuf_put_stringb(m, b);
737: out:
738: sshbuf_free(b);
739: return r;
1.1 deraadt 740: }
1.125 deraadt 741:
1.201 markus 742: /* Deserialise compression state from a blob for privsep */
743: static int
744: ssh_packet_set_compress_state(struct ssh *ssh, struct sshbuf *m)
1.162 andreas 745: {
1.201 markus 746: struct session_state *state = ssh->state;
747: struct sshbuf *b = NULL;
748: int r;
749: const u_char *inblob, *outblob;
750: size_t inl, outl;
1.162 andreas 751:
1.201 markus 752: if ((r = sshbuf_froms(m, &b)) != 0)
753: goto out;
754: if ((r = sshbuf_get_string_direct(b, &inblob, &inl)) != 0 ||
755: (r = sshbuf_get_string_direct(b, &outblob, &outl)) != 0)
756: goto out;
757: if (inl == 0)
758: state->compression_in_started = 0;
759: else if (inl != sizeof(state->compression_in_stream)) {
760: r = SSH_ERR_INTERNAL_ERROR;
761: goto out;
762: } else {
763: state->compression_in_started = 1;
764: memcpy(&state->compression_in_stream, inblob, inl);
765: }
766: if (outl == 0)
767: state->compression_out_started = 0;
768: else if (outl != sizeof(state->compression_out_stream)) {
769: r = SSH_ERR_INTERNAL_ERROR;
770: goto out;
771: } else {
772: state->compression_out_started = 1;
773: memcpy(&state->compression_out_stream, outblob, outl);
774: }
775: r = 0;
776: out:
777: sshbuf_free(b);
778: return r;
1.1 deraadt 779: }
1.125 deraadt 780:
1.24 markus 781: void
1.201 markus 782: ssh_packet_set_compress_hooks(struct ssh *ssh, void *ctx,
783: void *(*allocfunc)(void *, u_int, u_int),
784: void (*freefunc)(void *, void *))
785: {
786: ssh->state->compression_out_stream.zalloc = (alloc_func)allocfunc;
787: ssh->state->compression_out_stream.zfree = (free_func)freefunc;
788: ssh->state->compression_out_stream.opaque = ctx;
789: ssh->state->compression_in_stream.zalloc = (alloc_func)allocfunc;
790: ssh->state->compression_in_stream.zfree = (free_func)freefunc;
791: ssh->state->compression_in_stream.opaque = ctx;
1.24 markus 792: }
1.125 deraadt 793:
1.201 markus 794: /*
795: * Causes any further packets to be encrypted using the given key. The same
796: * key is used for both sending and reception. However, both directions are
797: * encrypted independently of each other.
798: */
1.125 deraadt 799:
1.2 provos 800: void
1.201 markus 801: ssh_packet_set_encryption_key(struct ssh *ssh, const u_char *key, u_int keylen, int number)
1.1 deraadt 802: {
1.211 djm 803: #ifndef WITH_SSH1
804: fatal("no SSH protocol 1 support");
805: #else /* WITH_SSH1 */
1.201 markus 806: struct session_state *state = ssh->state;
807: const struct sshcipher *cipher = cipher_by_number(number);
808: int r;
809: const char *wmsg;
1.125 deraadt 810:
1.201 markus 811: if (cipher == NULL)
812: fatal("%s: unknown cipher number %d", __func__, number);
813: if (keylen < 20)
814: fatal("%s: keylen too small: %d", __func__, keylen);
815: if (keylen > SSH_SESSION_KEY_LENGTH)
816: fatal("%s: keylen too big: %d", __func__, keylen);
817: memcpy(state->ssh1_key, key, keylen);
818: state->ssh1_keylen = keylen;
819: if ((r = cipher_init(&state->send_context, cipher, key, keylen,
820: NULL, 0, CIPHER_ENCRYPT)) != 0 ||
821: (r = cipher_init(&state->receive_context, cipher, key, keylen,
822: NULL, 0, CIPHER_DECRYPT) != 0))
823: fatal("%s: cipher_init failed: %s", __func__, ssh_err(r));
824: if (!state->cipher_warning_done &&
825: ((wmsg = cipher_warning_message(&state->send_context)) != NULL ||
826: (wmsg = cipher_warning_message(&state->send_context)) != NULL)) {
827: error("Warning: %s", wmsg);
828: state->cipher_warning_done = 1;
829: }
1.211 djm 830: #endif /* WITH_SSH1 */
1.170 djm 831: }
832:
1.16 markus 833: /*
834: * Finalizes and sends the packet. If the encryption key has been set,
835: * encrypts the packet before sending.
836: */
1.14 markus 837:
1.201 markus 838: int
839: ssh_packet_send1(struct ssh *ssh)
1.1 deraadt 840: {
1.201 markus 841: struct session_state *state = ssh->state;
1.89 markus 842: u_char buf[8], *cp;
1.201 markus 843: int r, padding, len;
1.40 markus 844: u_int checksum;
1.14 markus 845:
1.16 markus 846: /*
847: * If using packet compression, compress the payload of the outgoing
848: * packet.
849: */
1.201 markus 850: if (state->packet_compression) {
851: sshbuf_reset(state->compression_buffer);
1.14 markus 852: /* Skip padding. */
1.201 markus 853: if ((r = sshbuf_consume(state->outgoing_packet, 8)) != 0)
854: goto out;
1.14 markus 855: /* padding */
1.201 markus 856: if ((r = sshbuf_put(state->compression_buffer,
857: "\0\0\0\0\0\0\0\0", 8)) != 0)
858: goto out;
859: if ((r = compress_buffer(ssh, state->outgoing_packet,
860: state->compression_buffer)) != 0)
861: goto out;
862: sshbuf_reset(state->outgoing_packet);
863: if ((r = sshbuf_putb(state->outgoing_packet,
864: state->compression_buffer)) != 0)
865: goto out;
1.14 markus 866: }
867: /* Compute packet length without padding (add checksum, remove padding). */
1.201 markus 868: len = sshbuf_len(state->outgoing_packet) + 4 - 8;
1.14 markus 869:
1.32 markus 870: /* Insert padding. Initialized to zero in packet_start1() */
1.14 markus 871: padding = 8 - len % 8;
1.201 markus 872: if (!state->send_context.plaintext) {
873: cp = sshbuf_mutable_ptr(state->outgoing_packet);
874: if (cp == NULL) {
875: r = SSH_ERR_INTERNAL_ERROR;
876: goto out;
1.14 markus 877: }
1.201 markus 878: arc4random_buf(cp + 8 - padding, padding);
1.14 markus 879: }
1.201 markus 880: if ((r = sshbuf_consume(state->outgoing_packet, 8 - padding)) != 0)
881: goto out;
1.14 markus 882:
883: /* Add check bytes. */
1.201 markus 884: checksum = ssh_crc32(sshbuf_ptr(state->outgoing_packet),
885: sshbuf_len(state->outgoing_packet));
886: POKE_U32(buf, checksum);
887: if ((r = sshbuf_put(state->outgoing_packet, buf, 4)) != 0)
888: goto out;
1.1 deraadt 889:
890: #ifdef PACKET_DEBUG
1.14 markus 891: fprintf(stderr, "packet_send plain: ");
1.201 markus 892: sshbuf_dump(state->outgoing_packet, stderr);
1.1 deraadt 893: #endif
894:
1.14 markus 895: /* Append to output. */
1.201 markus 896: POKE_U32(buf, len);
897: if ((r = sshbuf_put(state->output, buf, 4)) != 0)
898: goto out;
899: if ((r = sshbuf_reserve(state->output,
900: sshbuf_len(state->outgoing_packet), &cp)) != 0)
901: goto out;
902: if ((r = cipher_crypt(&state->send_context, 0, cp,
903: sshbuf_ptr(state->outgoing_packet),
904: sshbuf_len(state->outgoing_packet), 0, 0)) != 0)
905: goto out;
1.14 markus 906:
1.1 deraadt 907: #ifdef PACKET_DEBUG
1.14 markus 908: fprintf(stderr, "encrypted: ");
1.201 markus 909: sshbuf_dump(state->output, stderr);
1.1 deraadt 910: #endif
1.201 markus 911: state->p_send.packets++;
912: state->p_send.bytes += len +
913: sshbuf_len(state->outgoing_packet);
914: sshbuf_reset(state->outgoing_packet);
1.1 deraadt 915:
1.16 markus 916: /*
1.120 djm 917: * Note that the packet is now only buffered in output. It won't be
1.205 djm 918: * actually sent until ssh_packet_write_wait or ssh_packet_write_poll
919: * is called.
1.16 markus 920: */
1.201 markus 921: r = 0;
922: out:
923: return r;
1.1 deraadt 924: }
925:
1.201 markus 926: int
927: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 928: {
1.201 markus 929: struct session_state *state = ssh->state;
930: struct sshenc *enc;
931: struct sshmac *mac;
932: struct sshcomp *comp;
933: struct sshcipher_ctx *cc;
1.105 markus 934: u_int64_t *max_blocks;
1.201 markus 935: const char *wmsg;
1.197 djm 936: int r, crypt_type;
1.57 markus 937:
1.100 markus 938: debug2("set_newkeys: mode %d", mode);
1.57 markus 939:
1.88 markus 940: if (mode == MODE_OUT) {
1.201 markus 941: cc = &state->send_context;
1.115 avsm 942: crypt_type = CIPHER_ENCRYPT;
1.201 markus 943: state->p_send.packets = state->p_send.blocks = 0;
944: max_blocks = &state->max_blocks_out;
1.88 markus 945: } else {
1.201 markus 946: cc = &state->receive_context;
1.115 avsm 947: crypt_type = CIPHER_DECRYPT;
1.201 markus 948: state->p_read.packets = state->p_read.blocks = 0;
949: max_blocks = &state->max_blocks_in;
1.88 markus 950: }
1.201 markus 951: if (state->newkeys[mode] != NULL) {
1.224 dtucker 952: debug("set_newkeys: rekeying, input %llu bytes %llu blocks, "
953: "output %llu bytes %llu blocks",
1.227 djm 954: (unsigned long long)state->p_read.bytes,
955: (unsigned long long)state->p_read.blocks,
956: (unsigned long long)state->p_send.bytes,
957: (unsigned long long)state->p_send.blocks);
1.201 markus 958: if ((r = cipher_cleanup(cc)) != 0)
959: return r;
960: enc = &state->newkeys[mode]->enc;
961: mac = &state->newkeys[mode]->mac;
962: comp = &state->newkeys[mode]->comp;
1.148 pvalchev 963: mac_clear(mac);
1.192 djm 964: explicit_bzero(enc->iv, enc->iv_len);
965: explicit_bzero(enc->key, enc->key_len);
966: explicit_bzero(mac->key, mac->key_len);
1.186 djm 967: free(enc->name);
968: free(enc->iv);
969: free(enc->key);
970: free(mac->name);
971: free(mac->key);
972: free(comp->name);
1.201 markus 973: free(state->newkeys[mode]);
1.57 markus 974: }
1.201 markus 975: /* move newkeys from kex to state */
976: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
977: return SSH_ERR_INTERNAL_ERROR;
978: ssh->kex->newkeys[mode] = NULL;
979: enc = &state->newkeys[mode]->enc;
980: mac = &state->newkeys[mode]->mac;
981: comp = &state->newkeys[mode]->comp;
982: if (cipher_authlen(enc->cipher) == 0) {
983: if ((r = mac_init(mac)) != 0)
984: return r;
985: }
986: mac->enabled = 1;
1.57 markus 987: DBG(debug("cipher_init_context: %d", mode));
1.197 djm 988: if ((r = cipher_init(cc, enc->cipher, enc->key, enc->key_len,
989: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 990: return r;
991: if (!state->cipher_warning_done &&
992: (wmsg = cipher_warning_message(cc)) != NULL) {
993: error("Warning: %s", wmsg);
994: state->cipher_warning_done = 1;
995: }
1.91 markus 996: /* Deleting the keys does not gain extra security */
1.192 djm 997: /* explicit_bzero(enc->iv, enc->block_size);
998: explicit_bzero(enc->key, enc->key_len);
999: explicit_bzero(mac->key, mac->key_len); */
1.118 markus 1000: if ((comp->type == COMP_ZLIB ||
1.161 andreas 1001: (comp->type == COMP_DELAYED &&
1.201 markus 1002: state->after_authentication)) && comp->enabled == 0) {
1003: if ((r = ssh_packet_init_compression(ssh)) < 0)
1004: return r;
1005: if (mode == MODE_OUT) {
1006: if ((r = start_compression_out(ssh, 6)) != 0)
1007: return r;
1008: } else {
1009: if ((r = start_compression_in(ssh)) != 0)
1010: return r;
1011: }
1.57 markus 1012: comp->enabled = 1;
1013: }
1.109 markus 1014: /*
1015: * The 2^(blocksize*2) limit is too expensive for 3DES,
1016: * blowfish, etc, so enforce a 1GB limit for small blocksizes.
1017: */
1018: if (enc->block_size >= 16)
1019: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
1020: else
1021: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 1022: if (state->rekey_limit)
1.161 andreas 1023: *max_blocks = MIN(*max_blocks,
1.201 markus 1024: state->rekey_limit / enc->block_size);
1.227 djm 1025: debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1.201 markus 1026: return 0;
1.57 markus 1027: }
1028:
1.228 djm 1029: #define MAX_PACKETS (1U<<31)
1030: static int
1031: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
1032: {
1033: struct session_state *state = ssh->state;
1034: u_int32_t out_blocks;
1035:
1036: /* XXX client can't cope with rekeying pre-auth */
1037: if (!state->after_authentication)
1038: return 0;
1039:
1040: /* Haven't keyed yet or KEX in progress. */
1041: if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
1042: return 0;
1043:
1044: /* Peer can't rekey */
1045: if (ssh->compat & SSH_BUG_NOREKEY)
1046: return 0;
1047:
1048: /*
1049: * Permit one packet in or out per rekey - this allows us to
1050: * make progress when rekey limits are very small.
1051: */
1052: if (state->p_send.packets == 0 && state->p_read.packets == 0)
1053: return 0;
1054:
1055: /* Time-based rekeying */
1056: if (state->rekey_interval != 0 &&
1057: state->rekey_time + state->rekey_interval <= monotime())
1058: return 1;
1059:
1060: /* Always rekey when MAX_PACKETS sent in either direction */
1061: if (state->p_send.packets > MAX_PACKETS ||
1062: state->p_read.packets > MAX_PACKETS)
1063: return 1;
1064:
1065: /* Rekey after (cipher-specific) maxiumum blocks */
1066: out_blocks = roundup(outbound_packet_len,
1067: state->newkeys[MODE_OUT]->enc.block_size);
1068: return (state->max_blocks_out &&
1069: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
1070: (state->max_blocks_in &&
1071: (state->p_read.blocks > state->max_blocks_in));
1072: }
1073:
1.16 markus 1074: /*
1.118 markus 1075: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 1076: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 1077: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
1078: */
1.201 markus 1079: static int
1080: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 1081: {
1.201 markus 1082: struct session_state *state = ssh->state;
1083: struct sshcomp *comp = NULL;
1084: int r, mode;
1.118 markus 1085:
1086: /*
1087: * Remember that we are past the authentication step, so rekeying
1088: * with COMP_DELAYED will turn on compression immediately.
1089: */
1.201 markus 1090: state->after_authentication = 1;
1.118 markus 1091: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 1092: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 1093: if (state->newkeys[mode] == NULL)
1.145 markus 1094: continue;
1.201 markus 1095: comp = &state->newkeys[mode]->comp;
1.118 markus 1096: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 1097: if ((r = ssh_packet_init_compression(ssh)) != 0)
1098: return r;
1099: if (mode == MODE_OUT) {
1100: if ((r = start_compression_out(ssh, 6)) != 0)
1101: return r;
1102: } else {
1103: if ((r = start_compression_in(ssh)) != 0)
1104: return r;
1105: }
1.118 markus 1106: comp->enabled = 1;
1107: }
1108: }
1.201 markus 1109: return 0;
1.118 markus 1110: }
1111:
1.226 djm 1112: /* Used to mute debug logging for noisy packet types */
1113: static int
1114: ssh_packet_log_type(u_char type)
1115: {
1116: switch (type) {
1117: case SSH2_MSG_CHANNEL_DATA:
1118: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1119: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1120: return 0;
1121: default:
1122: return 1;
1123: }
1124: }
1125:
1.118 markus 1126: /*
1.25 markus 1127: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1128: */
1.201 markus 1129: int
1130: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1131: {
1.201 markus 1132: struct session_state *state = ssh->state;
1.200 markus 1133: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.178 markus 1134: u_char padlen, pad = 0;
1.201 markus 1135: u_int authlen = 0, aadlen = 0;
1136: u_int len;
1137: struct sshenc *enc = NULL;
1138: struct sshmac *mac = NULL;
1139: struct sshcomp *comp = NULL;
1140: int r, block_size;
1141:
1142: if (state->newkeys[MODE_OUT] != NULL) {
1143: enc = &state->newkeys[MODE_OUT]->enc;
1144: mac = &state->newkeys[MODE_OUT]->mac;
1145: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1146: /* disable mac for authenticated encryption */
1147: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1148: mac = NULL;
1.25 markus 1149: }
1.88 markus 1150: block_size = enc ? enc->block_size : 8;
1.180 markus 1151: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1152:
1.201 markus 1153: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1154: if (ssh_packet_log_type(type))
1155: debug3("send packet: type %u", type);
1.25 markus 1156: #ifdef PACKET_DEBUG
1157: fprintf(stderr, "plain: ");
1.201 markus 1158: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1159: #endif
1160:
1161: if (comp && comp->enabled) {
1.201 markus 1162: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1163: /* skip header, compress only payload */
1.201 markus 1164: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1165: goto out;
1166: sshbuf_reset(state->compression_buffer);
1167: if ((r = compress_buffer(ssh, state->outgoing_packet,
1168: state->compression_buffer)) != 0)
1169: goto out;
1170: sshbuf_reset(state->outgoing_packet);
1171: if ((r = sshbuf_put(state->outgoing_packet,
1172: "\0\0\0\0\0", 5)) != 0 ||
1173: (r = sshbuf_putb(state->outgoing_packet,
1174: state->compression_buffer)) != 0)
1175: goto out;
1176: DBG(debug("compression: raw %d compressed %zd", len,
1177: sshbuf_len(state->outgoing_packet)));
1.25 markus 1178: }
1179:
1180: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1181: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1182:
1183: /*
1184: * calc size of padding, alloc space, get random data,
1185: * minimum padding is 4 bytes
1186: */
1.178 markus 1187: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1188: padlen = block_size - (len % block_size);
1189: if (padlen < 4)
1190: padlen += block_size;
1.201 markus 1191: if (state->extra_pad) {
1.71 markus 1192: /* will wrap if extra_pad+padlen > 255 */
1.201 markus 1193: state->extra_pad =
1194: roundup(state->extra_pad, block_size);
1195: pad = state->extra_pad -
1196: ((len + padlen) % state->extra_pad);
1.193 djm 1197: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1198: __func__, pad, len, padlen, state->extra_pad));
1.71 markus 1199: padlen += pad;
1.201 markus 1200: state->extra_pad = 0;
1.71 markus 1201: }
1.201 markus 1202: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1203: goto out;
1204: if (enc && !state->send_context.plaintext) {
1.32 markus 1205: /* random padding */
1.201 markus 1206: arc4random_buf(cp, padlen);
1.32 markus 1207: } else {
1208: /* clear padding */
1.192 djm 1209: explicit_bzero(cp, padlen);
1.25 markus 1210: }
1.178 markus 1211: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1212: len = sshbuf_len(state->outgoing_packet);
1213: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1214: if (cp == NULL) {
1215: r = SSH_ERR_INTERNAL_ERROR;
1216: goto out;
1217: }
1.25 markus 1218: /* packet_length includes payload, padding and padding length field */
1.201 markus 1219: POKE_U32(cp, len - 4);
1.89 markus 1220: cp[4] = padlen;
1.178 markus 1221: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1222: len, padlen, aadlen));
1.25 markus 1223:
1224: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1225: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1226: if ((r = mac_compute(mac, state->p_send.seqnr,
1227: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1228: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1229: goto out;
1230: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1231: }
1232: /* encrypt packet and append to output buffer. */
1.201 markus 1233: if ((r = sshbuf_reserve(state->output,
1234: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1235: goto out;
1236: if ((r = cipher_crypt(&state->send_context, state->p_send.seqnr, cp,
1237: sshbuf_ptr(state->outgoing_packet),
1238: len - aadlen, aadlen, authlen)) != 0)
1239: goto out;
1.25 markus 1240: /* append unencrypted MAC */
1.178 markus 1241: if (mac && mac->enabled) {
1242: if (mac->etm) {
1243: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1244: if ((r = mac_compute(mac, state->p_send.seqnr,
1245: cp, len, macbuf, sizeof(macbuf))) != 0)
1246: goto out;
1.178 markus 1247: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1248: state->p_send.seqnr));
1.178 markus 1249: }
1.201 markus 1250: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1251: goto out;
1.178 markus 1252: }
1.25 markus 1253: #ifdef PACKET_DEBUG
1254: fprintf(stderr, "encrypted: ");
1.201 markus 1255: sshbuf_dump(state->output, stderr);
1.25 markus 1256: #endif
1.29 markus 1257: /* increment sequence number for outgoing packets */
1.201 markus 1258: if (++state->p_send.seqnr == 0)
1.106 itojun 1259: logit("outgoing seqnr wraps around");
1.201 markus 1260: if (++state->p_send.packets == 0)
1261: if (!(ssh->compat & SSH_BUG_NOREKEY))
1262: return SSH_ERR_NEED_REKEY;
1263: state->p_send.blocks += len / block_size;
1264: state->p_send.bytes += len;
1265: sshbuf_reset(state->outgoing_packet);
1.25 markus 1266:
1.57 markus 1267: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1268: r = ssh_set_newkeys(ssh, MODE_OUT);
1269: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1270: r = ssh_packet_enable_delayed_compress(ssh);
1271: else
1272: r = 0;
1273: out:
1274: return r;
1.25 markus 1275: }
1276:
1.228 djm 1277: /* returns non-zero if the specified packet type is usec by KEX */
1278: static int
1279: ssh_packet_type_is_kex(u_char type)
1280: {
1281: return
1282: type >= SSH2_MSG_TRANSPORT_MIN &&
1283: type <= SSH2_MSG_TRANSPORT_MAX &&
1284: type != SSH2_MSG_SERVICE_REQUEST &&
1285: type != SSH2_MSG_SERVICE_ACCEPT &&
1286: type != SSH2_MSG_EXT_INFO;
1287: }
1288:
1.201 markus 1289: int
1290: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1291: {
1.201 markus 1292: struct session_state *state = ssh->state;
1.105 markus 1293: struct packet *p;
1.201 markus 1294: u_char type;
1.228 djm 1295: int r, need_rekey;
1.105 markus 1296:
1.228 djm 1297: if (sshbuf_len(state->outgoing_packet) < 6)
1298: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1299: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1300: need_rekey = !ssh_packet_type_is_kex(type) &&
1301: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1302:
1.228 djm 1303: /*
1304: * During rekeying we can only send key exchange messages.
1305: * Queue everything else.
1306: */
1307: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1308: if (need_rekey)
1309: debug3("%s: rekex triggered", __func__);
1310: debug("enqueue packet: %u", type);
1311: p = calloc(1, sizeof(*p));
1312: if (p == NULL)
1313: return SSH_ERR_ALLOC_FAIL;
1314: p->type = type;
1315: p->payload = state->outgoing_packet;
1316: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1317: state->outgoing_packet = sshbuf_new();
1318: if (state->outgoing_packet == NULL)
1319: return SSH_ERR_ALLOC_FAIL;
1320: if (need_rekey) {
1321: /*
1322: * This packet triggered a rekey, so send the
1323: * KEXINIT now.
1324: * NB. reenters this function via kex_start_rekex().
1325: */
1326: return kex_start_rekex(ssh);
1.105 markus 1327: }
1.228 djm 1328: return 0;
1.105 markus 1329: }
1330:
1331: /* rekeying starts with sending KEXINIT */
1332: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1333: state->rekeying = 1;
1.105 markus 1334:
1.201 markus 1335: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1336: return r;
1.105 markus 1337:
1338: /* after a NEWKEYS message we can send the complete queue */
1339: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1340: state->rekeying = 0;
1341: state->rekey_time = monotime();
1342: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1343: type = p->type;
1.228 djm 1344: /*
1345: * If this packet triggers a rekex, then skip the
1346: * remaining packets in the queue for now.
1347: * NB. re-enters this function via kex_start_rekex.
1348: */
1349: if (ssh_packet_need_rekeying(ssh,
1350: sshbuf_len(p->payload))) {
1351: debug3("%s: queued packet triggered rekex",
1352: __func__);
1353: return kex_start_rekex(ssh);
1354: }
1.105 markus 1355: debug("dequeue packet: %u", type);
1.201 markus 1356: sshbuf_free(state->outgoing_packet);
1357: state->outgoing_packet = p->payload;
1358: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1359: memset(p, 0, sizeof(*p));
1.186 djm 1360: free(p);
1.201 markus 1361: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1362: return r;
1.105 markus 1363: }
1364: }
1.201 markus 1365: return 0;
1.25 markus 1366: }
1367:
1368: /*
1.16 markus 1369: * Waits until a packet has been received, and returns its type. Note that
1370: * no other data is processed until this returns, so this function should not
1371: * be used during the interactive session.
1372: */
1.1 deraadt 1373:
1.2 provos 1374: int
1.201 markus 1375: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1376: {
1.201 markus 1377: struct session_state *state = ssh->state;
1.222 markus 1378: int len, r, ms_remain;
1.56 millert 1379: fd_set *setp;
1.14 markus 1380: char buf[8192];
1.155 deraadt 1381: struct timeval timeout, start, *timeoutp = NULL;
1382:
1.25 markus 1383: DBG(debug("packet_read()"));
1.14 markus 1384:
1.214 deraadt 1385: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1386: NFDBITS), sizeof(fd_mask));
1.201 markus 1387: if (setp == NULL)
1388: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1389:
1.205 djm 1390: /*
1391: * Since we are blocking, ensure that all written packets have
1392: * been sent.
1393: */
1.210 markus 1394: if ((r = ssh_packet_write_wait(ssh)) != 0)
1395: goto out;
1.14 markus 1396:
1397: /* Stay in the loop until we have received a complete packet. */
1398: for (;;) {
1399: /* Try to read a packet from the buffer. */
1.201 markus 1400: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1401: if (r != 0)
1402: break;
1.62 markus 1403: if (!compat20 && (
1.201 markus 1404: *typep == SSH_SMSG_SUCCESS
1405: || *typep == SSH_SMSG_FAILURE
1406: || *typep == SSH_CMSG_EOF
1407: || *typep == SSH_CMSG_EXIT_CONFIRMATION))
1408: if ((r = sshpkt_get_end(ssh)) != 0)
1409: break;
1.14 markus 1410: /* If we got a packet, return it. */
1.201 markus 1411: if (*typep != SSH_MSG_NONE)
1412: break;
1.16 markus 1413: /*
1414: * Otherwise, wait for some data to arrive, add it to the
1415: * buffer, and try again.
1416: */
1.201 markus 1417: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1418: NFDBITS) * sizeof(fd_mask));
1.201 markus 1419: FD_SET(state->connection_in, setp);
1.16 markus 1420:
1.201 markus 1421: if (state->packet_timeout_ms > 0) {
1422: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1423: timeoutp = &timeout;
1424: }
1.14 markus 1425: /* Wait for some data to arrive. */
1.154 dtucker 1426: for (;;) {
1.201 markus 1427: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1428: ms_to_timeval(&timeout, ms_remain);
1429: gettimeofday(&start, NULL);
1430: }
1.201 markus 1431: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1432: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1433: break;
1.161 andreas 1434: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1435: break;
1.201 markus 1436: if (state->packet_timeout_ms == -1)
1.154 dtucker 1437: continue;
1438: ms_subtract_diff(&start, &ms_remain);
1439: if (ms_remain <= 0) {
1.201 markus 1440: r = 0;
1.154 dtucker 1441: break;
1442: }
1443: }
1.204 djm 1444: if (r == 0)
1445: return SSH_ERR_CONN_TIMEOUT;
1.14 markus 1446: /* Read data from the socket. */
1.222 markus 1447: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1448: if (len == 0) {
1449: r = SSH_ERR_CONN_CLOSED;
1450: goto out;
1451: }
1452: if (len < 0) {
1453: r = SSH_ERR_SYSTEM_ERROR;
1454: goto out;
1455: }
1.204 djm 1456:
1.14 markus 1457: /* Append it to the buffer. */
1.204 djm 1458: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1459: goto out;
1.14 markus 1460: }
1.210 markus 1461: out:
1.201 markus 1462: free(setp);
1463: return r;
1.1 deraadt 1464: }
1465:
1.77 djm 1466: int
1.201 markus 1467: ssh_packet_read(struct ssh *ssh)
1.77 djm 1468: {
1.201 markus 1469: u_char type;
1470: int r;
1471:
1472: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1473: fatal("%s: %s", __func__, ssh_err(r));
1474: return type;
1.77 djm 1475: }
1476:
1.16 markus 1477: /*
1478: * Waits until a packet has been received, verifies that its type matches
1479: * that given, and gives a fatal error and exits if there is a mismatch.
1480: */
1.1 deraadt 1481:
1.205 djm 1482: int
1483: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1484: {
1.205 djm 1485: int r;
1486: u_char type;
1.1 deraadt 1487:
1.205 djm 1488: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1489: return r;
1490: if (type != expected_type) {
1491: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1492: "Protocol error: expected packet type %d, got %d",
1.205 djm 1493: expected_type, type)) != 0)
1494: return r;
1495: return SSH_ERR_PROTOCOL_ERROR;
1496: }
1497: return 0;
1.1 deraadt 1498: }
1499:
1500: /* Checks if a full packet is available in the data received so far via
1.14 markus 1501: * packet_process_incoming. If so, reads the packet; otherwise returns
1502: * SSH_MSG_NONE. This does not wait for data from the connection.
1503: *
1.150 dtucker 1504: * SSH_MSG_DISCONNECT is handled specially here. Also,
1505: * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1506: * to higher levels.
1.14 markus 1507: */
1.1 deraadt 1508:
1.201 markus 1509: int
1510: ssh_packet_read_poll1(struct ssh *ssh, u_char *typep)
1.1 deraadt 1511: {
1.201 markus 1512: struct session_state *state = ssh->state;
1.40 markus 1513: u_int len, padded_len;
1.205 djm 1514: const char *emsg;
1.201 markus 1515: const u_char *cp;
1516: u_char *p;
1.40 markus 1517: u_int checksum, stored_checksum;
1.201 markus 1518: int r;
1519:
1520: *typep = SSH_MSG_NONE;
1.14 markus 1521:
1522: /* Check if input size is less than minimum packet size. */
1.201 markus 1523: if (sshbuf_len(state->input) < 4 + 8)
1524: return 0;
1.14 markus 1525: /* Get length of incoming packet. */
1.201 markus 1526: len = PEEK_U32(sshbuf_ptr(state->input));
1.205 djm 1527: if (len < 1 + 2 + 2 || len > 256 * 1024) {
1528: if ((r = sshpkt_disconnect(ssh, "Bad packet length %u",
1529: len)) != 0)
1530: return r;
1531: return SSH_ERR_CONN_CORRUPT;
1532: }
1.14 markus 1533: padded_len = (len + 8) & ~7;
1534:
1535: /* Check if the packet has been entirely received. */
1.201 markus 1536: if (sshbuf_len(state->input) < 4 + padded_len)
1537: return 0;
1.14 markus 1538:
1539: /* The entire packet is in buffer. */
1540:
1541: /* Consume packet length. */
1.201 markus 1542: if ((r = sshbuf_consume(state->input, 4)) != 0)
1543: goto out;
1.14 markus 1544:
1.62 markus 1545: /*
1546: * Cryptographic attack detector for ssh
1547: * (C)1998 CORE-SDI, Buenos Aires Argentina
1548: * Ariel Futoransky(futo@core-sdi.com)
1549: */
1.201 markus 1550: if (!state->receive_context.plaintext) {
1.205 djm 1551: emsg = NULL;
1.201 markus 1552: switch (detect_attack(&state->deattack,
1553: sshbuf_ptr(state->input), padded_len)) {
1554: case DEATTACK_OK:
1555: break;
1.144 djm 1556: case DEATTACK_DETECTED:
1.205 djm 1557: emsg = "crc32 compensation attack detected";
1558: break;
1.144 djm 1559: case DEATTACK_DOS_DETECTED:
1.205 djm 1560: emsg = "deattack denial of service detected";
1561: break;
1.201 markus 1562: default:
1.205 djm 1563: emsg = "deattack error";
1564: break;
1565: }
1566: if (emsg != NULL) {
1567: error("%s", emsg);
1568: if ((r = sshpkt_disconnect(ssh, "%s", emsg)) != 0 ||
1569: (r = ssh_packet_write_wait(ssh)) != 0)
1570: return r;
1571: return SSH_ERR_CONN_CORRUPT;
1.144 djm 1572: }
1573: }
1.62 markus 1574:
1575: /* Decrypt data to incoming_packet. */
1.201 markus 1576: sshbuf_reset(state->incoming_packet);
1577: if ((r = sshbuf_reserve(state->incoming_packet, padded_len, &p)) != 0)
1578: goto out;
1579: if ((r = cipher_crypt(&state->receive_context, 0, p,
1580: sshbuf_ptr(state->input), padded_len, 0, 0)) != 0)
1581: goto out;
1.62 markus 1582:
1.201 markus 1583: if ((r = sshbuf_consume(state->input, padded_len)) != 0)
1584: goto out;
1.1 deraadt 1585:
1586: #ifdef PACKET_DEBUG
1.14 markus 1587: fprintf(stderr, "read_poll plain: ");
1.201 markus 1588: sshbuf_dump(state->incoming_packet, stderr);
1.1 deraadt 1589: #endif
1590:
1.14 markus 1591: /* Compute packet checksum. */
1.201 markus 1592: checksum = ssh_crc32(sshbuf_ptr(state->incoming_packet),
1593: sshbuf_len(state->incoming_packet) - 4);
1.14 markus 1594:
1595: /* Skip padding. */
1.201 markus 1596: if ((r = sshbuf_consume(state->incoming_packet, 8 - len % 8)) != 0)
1597: goto out;
1.14 markus 1598:
1599: /* Test check bytes. */
1.205 djm 1600: if (len != sshbuf_len(state->incoming_packet)) {
1601: error("%s: len %d != sshbuf_len %zd", __func__,
1.201 markus 1602: len, sshbuf_len(state->incoming_packet));
1.205 djm 1603: if ((r = sshpkt_disconnect(ssh, "invalid packet length")) != 0 ||
1604: (r = ssh_packet_write_wait(ssh)) != 0)
1605: return r;
1606: return SSH_ERR_CONN_CORRUPT;
1607: }
1.14 markus 1608:
1.201 markus 1609: cp = sshbuf_ptr(state->incoming_packet) + len - 4;
1610: stored_checksum = PEEK_U32(cp);
1.205 djm 1611: if (checksum != stored_checksum) {
1612: error("Corrupted check bytes on input");
1613: if ((r = sshpkt_disconnect(ssh, "connection corrupted")) != 0 ||
1614: (r = ssh_packet_write_wait(ssh)) != 0)
1615: return r;
1616: return SSH_ERR_CONN_CORRUPT;
1617: }
1.201 markus 1618: if ((r = sshbuf_consume_end(state->incoming_packet, 4)) < 0)
1619: goto out;
1620:
1621: if (state->packet_compression) {
1622: sshbuf_reset(state->compression_buffer);
1623: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1624: state->compression_buffer)) != 0)
1625: goto out;
1626: sshbuf_reset(state->incoming_packet);
1627: if ((r = sshbuf_putb(state->incoming_packet,
1628: state->compression_buffer)) != 0)
1629: goto out;
1630: }
1631: state->p_read.packets++;
1632: state->p_read.bytes += padded_len + 4;
1633: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1634: goto out;
1.205 djm 1635: if (*typep < SSH_MSG_MIN || *typep > SSH_MSG_MAX) {
1636: error("Invalid ssh1 packet type: %d", *typep);
1637: if ((r = sshpkt_disconnect(ssh, "invalid packet type")) != 0 ||
1638: (r = ssh_packet_write_wait(ssh)) != 0)
1639: return r;
1640: return SSH_ERR_PROTOCOL_ERROR;
1641: }
1.201 markus 1642: r = 0;
1643: out:
1644: return r;
1.1 deraadt 1645: }
1.14 markus 1646:
1.201 markus 1647: int
1648: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1649: {
1.201 markus 1650: struct session_state *state = ssh->state;
1.40 markus 1651: u_int padlen, need;
1.201 markus 1652: u_char *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1653: u_int maclen, aadlen = 0, authlen = 0, block_size;
1654: struct sshenc *enc = NULL;
1655: struct sshmac *mac = NULL;
1656: struct sshcomp *comp = NULL;
1.200 markus 1657: int r;
1.201 markus 1658:
1659: *typep = SSH_MSG_NONE;
1660:
1661: if (state->packet_discard)
1662: return 0;
1663:
1664: if (state->newkeys[MODE_IN] != NULL) {
1665: enc = &state->newkeys[MODE_IN]->enc;
1666: mac = &state->newkeys[MODE_IN]->mac;
1667: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1668: /* disable mac for authenticated encryption */
1669: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1670: mac = NULL;
1.25 markus 1671: }
1672: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1673: block_size = enc ? enc->block_size : 8;
1.180 markus 1674: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1675:
1.201 markus 1676: if (aadlen && state->packlen == 0) {
1677: if (cipher_get_length(&state->receive_context,
1678: &state->packlen, state->p_read.seqnr,
1679: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1680: return 0;
1681: if (state->packlen < 1 + 4 ||
1682: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1683: #ifdef PACKET_DEBUG
1.201 markus 1684: sshbuf_dump(state->input, stderr);
1.178 markus 1685: #endif
1.201 markus 1686: logit("Bad packet length %u.", state->packlen);
1687: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1688: return r;
1.217 djm 1689: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1690: }
1.201 markus 1691: sshbuf_reset(state->incoming_packet);
1692: } else if (state->packlen == 0) {
1.25 markus 1693: /*
1694: * check if input size is less than the cipher block size,
1695: * decrypt first block and extract length of incoming packet
1696: */
1.201 markus 1697: if (sshbuf_len(state->input) < block_size)
1698: return 0;
1699: sshbuf_reset(state->incoming_packet);
1700: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1701: &cp)) != 0)
1702: goto out;
1703: if ((r = cipher_crypt(&state->receive_context,
1704: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1705: block_size, 0, 0)) != 0)
1706: goto out;
1707: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1708: if (state->packlen < 1 + 4 ||
1709: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1710: #ifdef PACKET_DEBUG
1.201 markus 1711: fprintf(stderr, "input: \n");
1712: sshbuf_dump(state->input, stderr);
1713: fprintf(stderr, "incoming_packet: \n");
1714: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1715: #endif
1.201 markus 1716: logit("Bad packet length %u.", state->packlen);
1717: return ssh_packet_start_discard(ssh, enc, mac,
1718: state->packlen, PACKET_MAX_SIZE);
1.25 markus 1719: }
1.201 markus 1720: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1721: goto out;
1.25 markus 1722: }
1.201 markus 1723: DBG(debug("input: packet len %u", state->packlen+4));
1724:
1.178 markus 1725: if (aadlen) {
1726: /* only the payload is encrypted */
1.201 markus 1727: need = state->packlen;
1.178 markus 1728: } else {
1729: /*
1730: * the payload size and the payload are encrypted, but we
1731: * have a partial packet of block_size bytes
1732: */
1.201 markus 1733: need = 4 + state->packlen - block_size;
1.178 markus 1734: }
1.180 markus 1735: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1736: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1737: if (need % block_size != 0) {
1738: logit("padding error: need %d block %d mod %d",
1.25 markus 1739: need, block_size, need % block_size);
1.201 markus 1740: return ssh_packet_start_discard(ssh, enc, mac,
1741: state->packlen, PACKET_MAX_SIZE - block_size);
1.158 markus 1742: }
1.25 markus 1743: /*
1744: * check if the entire packet has been received and
1.178 markus 1745: * decrypt into incoming_packet:
1746: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1747: * 'need' bytes are encrypted, followed by either
1748: * 'authlen' bytes of authentication tag or
1.178 markus 1749: * 'maclen' bytes of message authentication code.
1.25 markus 1750: */
1.201 markus 1751: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1752: return 0;
1.25 markus 1753: #ifdef PACKET_DEBUG
1754: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1755: sshbuf_dump(state->input, stderr);
1.25 markus 1756: #endif
1.178 markus 1757: /* EtM: compute mac over encrypted input */
1.201 markus 1758: if (mac && mac->enabled && mac->etm) {
1759: if ((r = mac_compute(mac, state->p_read.seqnr,
1760: sshbuf_ptr(state->input), aadlen + need,
1.200 markus 1761: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1762: goto out;
1763: }
1764: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1765: &cp)) != 0)
1766: goto out;
1767: if ((r = cipher_crypt(&state->receive_context, state->p_read.seqnr, cp,
1768: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1769: goto out;
1770: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1771: goto out;
1.25 markus 1772: /*
1773: * compute MAC over seqnr and packet,
1774: * increment sequence number for incoming packet
1775: */
1.29 markus 1776: if (mac && mac->enabled) {
1.178 markus 1777: if (!mac->etm)
1.201 markus 1778: if ((r = mac_compute(mac, state->p_read.seqnr,
1779: sshbuf_ptr(state->incoming_packet),
1780: sshbuf_len(state->incoming_packet),
1.200 markus 1781: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1782: goto out;
1783: if (timingsafe_bcmp(macbuf, sshbuf_ptr(state->input),
1.161 andreas 1784: mac->mac_len) != 0) {
1.159 markus 1785: logit("Corrupted MAC on input.");
1786: if (need > PACKET_MAX_SIZE)
1.201 markus 1787: return SSH_ERR_INTERNAL_ERROR;
1788: return ssh_packet_start_discard(ssh, enc, mac,
1789: state->packlen, PACKET_MAX_SIZE - need);
1790: }
1791:
1792: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1793: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1794: goto out;
1.25 markus 1795: }
1.77 djm 1796: if (seqnr_p != NULL)
1.201 markus 1797: *seqnr_p = state->p_read.seqnr;
1798: if (++state->p_read.seqnr == 0)
1.106 itojun 1799: logit("incoming seqnr wraps around");
1.201 markus 1800: if (++state->p_read.packets == 0)
1801: if (!(ssh->compat & SSH_BUG_NOREKEY))
1802: return SSH_ERR_NEED_REKEY;
1803: state->p_read.blocks += (state->packlen + 4) / block_size;
1804: state->p_read.bytes += state->packlen + 4;
1.25 markus 1805:
1806: /* get padlen */
1.201 markus 1807: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1808: DBG(debug("input: padlen %d", padlen));
1.205 djm 1809: if (padlen < 4) {
1810: if ((r = sshpkt_disconnect(ssh,
1811: "Corrupted padlen %d on input.", padlen)) != 0 ||
1812: (r = ssh_packet_write_wait(ssh)) != 0)
1813: return r;
1814: return SSH_ERR_CONN_CORRUPT;
1815: }
1.25 markus 1816:
1817: /* skip packet size + padlen, discard padding */
1.201 markus 1818: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1819: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1820: goto out;
1.25 markus 1821:
1.201 markus 1822: DBG(debug("input: len before de-compress %zd",
1823: sshbuf_len(state->incoming_packet)));
1.25 markus 1824: if (comp && comp->enabled) {
1.201 markus 1825: sshbuf_reset(state->compression_buffer);
1826: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1827: state->compression_buffer)) != 0)
1828: goto out;
1829: sshbuf_reset(state->incoming_packet);
1830: if ((r = sshbuf_putb(state->incoming_packet,
1831: state->compression_buffer)) != 0)
1832: goto out;
1833: DBG(debug("input: len after de-compress %zd",
1834: sshbuf_len(state->incoming_packet)));
1.25 markus 1835: }
1836: /*
1837: * get packet type, implies consume.
1838: * return length of payload (without type field)
1839: */
1.201 markus 1840: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1841: goto out;
1.226 djm 1842: if (ssh_packet_log_type(*typep))
1843: debug3("receive packet: type %u", *typep);
1.205 djm 1844: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1845: if ((r = sshpkt_disconnect(ssh,
1846: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1847: (r = ssh_packet_write_wait(ssh)) != 0)
1848: return r;
1849: return SSH_ERR_PROTOCOL_ERROR;
1850: }
1.201 markus 1851: if (*typep == SSH2_MSG_NEWKEYS)
1852: r = ssh_set_newkeys(ssh, MODE_IN);
1853: else if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1854: r = ssh_packet_enable_delayed_compress(ssh);
1855: else
1856: r = 0;
1.25 markus 1857: #ifdef PACKET_DEBUG
1.201 markus 1858: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1859: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1860: #endif
1.62 markus 1861: /* reset for next packet */
1.201 markus 1862: state->packlen = 0;
1.228 djm 1863:
1864: /* do we need to rekey? */
1865: if (ssh_packet_need_rekeying(ssh, 0)) {
1866: debug3("%s: rekex triggered", __func__);
1867: if ((r = kex_start_rekex(ssh)) != 0)
1868: return r;
1869: }
1.201 markus 1870: out:
1871: return r;
1.25 markus 1872: }
1873:
1874: int
1.201 markus 1875: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1876: {
1.201 markus 1877: struct session_state *state = ssh->state;
1.96 deraadt 1878: u_int reason, seqnr;
1.201 markus 1879: int r;
1880: u_char *msg;
1.62 markus 1881:
1.25 markus 1882: for (;;) {
1.201 markus 1883: msg = NULL;
1.62 markus 1884: if (compat20) {
1.201 markus 1885: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1886: if (r != 0)
1887: return r;
1888: if (*typep) {
1889: state->keep_alive_timeouts = 0;
1890: DBG(debug("received packet type %d", *typep));
1.153 djm 1891: }
1.201 markus 1892: switch (*typep) {
1.150 dtucker 1893: case SSH2_MSG_IGNORE:
1.151 dtucker 1894: debug3("Received SSH2_MSG_IGNORE");
1.150 dtucker 1895: break;
1.25 markus 1896: case SSH2_MSG_DEBUG:
1.201 markus 1897: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1898: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1899: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1.219 mmcc 1900: free(msg);
1.201 markus 1901: return r;
1902: }
1.25 markus 1903: debug("Remote: %.900s", msg);
1.186 djm 1904: free(msg);
1.25 markus 1905: break;
1906: case SSH2_MSG_DISCONNECT:
1.201 markus 1907: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1908: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1909: return r;
1.182 djm 1910: /* Ignore normal client exit notifications */
1.201 markus 1911: do_log2(ssh->state->server_side &&
1.182 djm 1912: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1913: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1.220 djm 1914: "Received disconnect from %s port %d:"
1915: "%u: %.400s", ssh_remote_ipaddr(ssh),
1916: ssh_remote_port(ssh), reason, msg);
1.186 djm 1917: free(msg);
1.201 markus 1918: return SSH_ERR_DISCONNECTED;
1.84 markus 1919: case SSH2_MSG_UNIMPLEMENTED:
1.201 markus 1920: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1921: return r;
1.96 deraadt 1922: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1923: seqnr);
1.150 dtucker 1924: break;
1.25 markus 1925: default:
1.201 markus 1926: return 0;
1.48 stevesk 1927: }
1.25 markus 1928: } else {
1.201 markus 1929: r = ssh_packet_read_poll1(ssh, typep);
1930: switch (*typep) {
1.188 djm 1931: case SSH_MSG_NONE:
1932: return SSH_MSG_NONE;
1.25 markus 1933: case SSH_MSG_IGNORE:
1934: break;
1935: case SSH_MSG_DEBUG:
1.201 markus 1936: if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1937: return r;
1.25 markus 1938: debug("Remote: %.900s", msg);
1.186 djm 1939: free(msg);
1.25 markus 1940: break;
1941: case SSH_MSG_DISCONNECT:
1.201 markus 1942: if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1943: return r;
1.220 djm 1944: error("Received disconnect from %s port %d: "
1945: "%.400s", ssh_remote_ipaddr(ssh),
1946: ssh_remote_port(ssh), msg);
1.201 markus 1947: free(msg);
1948: return SSH_ERR_DISCONNECTED;
1.25 markus 1949: default:
1.201 markus 1950: DBG(debug("received packet type %d", *typep));
1951: return 0;
1.48 stevesk 1952: }
1.25 markus 1953: }
1954: }
1955: }
1956:
1.16 markus 1957: /*
1958: * Buffers the given amount of input characters. This is intended to be used
1959: * together with packet_read_poll.
1960: */
1.1 deraadt 1961:
1.204 djm 1962: int
1.201 markus 1963: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1964: {
1.201 markus 1965: struct session_state *state = ssh->state;
1966: int r;
1967:
1968: if (state->packet_discard) {
1969: state->keep_alive_timeouts = 0; /* ?? */
1970: if (len >= state->packet_discard) {
1971: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1972: return r;
1.201 markus 1973: }
1974: state->packet_discard -= len;
1.204 djm 1975: return 0;
1.159 markus 1976: }
1.201 markus 1977: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1978: return r;
1979:
1980: return 0;
1.28 markus 1981: }
1982:
1983: int
1.201 markus 1984: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1985: {
1.201 markus 1986: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1987: }
1988:
1.16 markus 1989: /*
1990: * Sends a diagnostic message from the server to the client. This message
1991: * can be sent at any time (but not while constructing another message). The
1992: * message is printed immediately, but only if the client is being executed
1993: * in verbose mode. These messages are primarily intended to ease debugging
1994: * authentication problems. The length of the formatted message must not
1.205 djm 1995: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1996: */
1.2 provos 1997: void
1.201 markus 1998: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1999: {
1.14 markus 2000: char buf[1024];
2001: va_list args;
1.201 markus 2002: int r;
1.39 markus 2003:
1.201 markus 2004: if (compat20 && (ssh->compat & SSH_BUG_DEBUG))
1.39 markus 2005: return;
1.14 markus 2006:
2007: va_start(args, fmt);
2008: vsnprintf(buf, sizeof(buf), fmt, args);
2009: va_end(args);
2010:
1.30 markus 2011: if (compat20) {
1.201 markus 2012: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
2013: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
2014: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2015: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2016: (r = sshpkt_send(ssh)) != 0)
2017: fatal("%s: %s", __func__, ssh_err(r));
1.30 markus 2018: } else {
1.201 markus 2019: if ((r = sshpkt_start(ssh, SSH_MSG_DEBUG)) != 0 ||
2020: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2021: (r = sshpkt_send(ssh)) != 0)
2022: fatal("%s: %s", __func__, ssh_err(r));
1.30 markus 2023: }
1.205 djm 2024: if ((r = ssh_packet_write_wait(ssh)) != 0)
2025: fatal("%s: %s", __func__, ssh_err(r));
2026: }
2027:
2028: /*
2029: * Pretty-print connection-terminating errors and exit.
2030: */
2031: void
2032: sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
2033: {
2034: switch (r) {
2035: case SSH_ERR_CONN_CLOSED:
1.220 djm 2036: logit("Connection closed by %.200s port %d",
2037: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.205 djm 2038: cleanup_exit(255);
2039: case SSH_ERR_CONN_TIMEOUT:
1.220 djm 2040: logit("Connection %s %.200s port %d timed out",
2041: ssh->state->server_side ? "from" : "to",
2042: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.205 djm 2043: cleanup_exit(255);
1.212 djm 2044: case SSH_ERR_DISCONNECTED:
1.220 djm 2045: logit("Disconnected from %.200s port %d",
2046: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.212 djm 2047: cleanup_exit(255);
2048: case SSH_ERR_SYSTEM_ERROR:
2049: if (errno == ECONNRESET) {
1.220 djm 2050: logit("Connection reset by %.200s port %d",
2051: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.212 djm 2052: cleanup_exit(255);
1.213 djm 2053: }
2054: /* FALLTHROUGH */
2055: case SSH_ERR_NO_CIPHER_ALG_MATCH:
2056: case SSH_ERR_NO_MAC_ALG_MATCH:
2057: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
2058: case SSH_ERR_NO_KEX_ALG_MATCH:
2059: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
2060: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.220 djm 2061: fatal("Unable to negotiate with %.200s port %d: %s. "
1.213 djm 2062: "Their offer: %s", ssh_remote_ipaddr(ssh),
1.220 djm 2063: ssh_remote_port(ssh), ssh_err(r),
2064: ssh->kex->failed_choice);
1.212 djm 2065: }
2066: /* FALLTHROUGH */
1.205 djm 2067: default:
1.220 djm 2068: fatal("%s%sConnection %s %.200s port %d: %s",
1.205 djm 2069: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 2070: ssh->state->server_side ? "from" : "to",
2071: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), ssh_err(r));
1.205 djm 2072: }
1.1 deraadt 2073: }
2074:
1.16 markus 2075: /*
2076: * Logs the error plus constructs and sends a disconnect packet, closes the
2077: * connection, and exits. This function never returns. The error message
2078: * should not contain a newline. The length of the formatted message must
2079: * not exceed 1024 bytes.
2080: */
1.2 provos 2081: void
1.201 markus 2082: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 2083: {
1.14 markus 2084: char buf[1024];
2085: va_list args;
2086: static int disconnecting = 0;
1.201 markus 2087: int r;
1.97 deraadt 2088:
1.14 markus 2089: if (disconnecting) /* Guard against recursive invocations. */
2090: fatal("packet_disconnect called recursively.");
2091: disconnecting = 1;
2092:
1.16 markus 2093: /*
2094: * Format the message. Note that the caller must make sure the
2095: * message is of limited size.
2096: */
1.14 markus 2097: va_start(args, fmt);
2098: vsnprintf(buf, sizeof(buf), fmt, args);
2099: va_end(args);
2100:
1.99 markus 2101: /* Display the error locally */
1.106 itojun 2102: logit("Disconnecting: %.100s", buf);
1.99 markus 2103:
1.205 djm 2104: /*
2105: * Send the disconnect message to the other side, and wait
2106: * for it to get sent.
2107: */
2108: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
2109: sshpkt_fatal(ssh, __func__, r);
2110:
2111: if ((r = ssh_packet_write_wait(ssh)) != 0)
2112: sshpkt_fatal(ssh, __func__, r);
1.14 markus 2113:
2114: /* Close the connection. */
1.201 markus 2115: ssh_packet_close(ssh);
1.112 markus 2116: cleanup_exit(255);
1.1 deraadt 2117: }
2118:
1.205 djm 2119: /*
2120: * Checks if there is any buffered output, and tries to write some of
2121: * the output.
2122: */
2123: int
1.201 markus 2124: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 2125: {
1.201 markus 2126: struct session_state *state = ssh->state;
2127: int len = sshbuf_len(state->output);
1.222 markus 2128: int r;
1.97 deraadt 2129:
1.14 markus 2130: if (len > 0) {
1.222 markus 2131: len = write(state->connection_out,
2132: sshbuf_ptr(state->output), len);
1.156 djm 2133: if (len == -1) {
2134: if (errno == EINTR || errno == EAGAIN)
1.205 djm 2135: return 0;
2136: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 2137: }
1.222 markus 2138: if (len == 0)
1.205 djm 2139: return SSH_ERR_CONN_CLOSED;
1.201 markus 2140: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 2141: return r;
1.14 markus 2142: }
1.205 djm 2143: return 0;
1.1 deraadt 2144: }
2145:
1.16 markus 2146: /*
2147: * Calls packet_write_poll repeatedly until all pending output data has been
2148: * written.
2149: */
1.205 djm 2150: int
1.201 markus 2151: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 2152: {
1.56 millert 2153: fd_set *setp;
1.205 djm 2154: int ret, r, ms_remain = 0;
1.154 dtucker 2155: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 2156: struct session_state *state = ssh->state;
1.56 millert 2157:
1.214 deraadt 2158: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 2159: NFDBITS), sizeof(fd_mask));
1.201 markus 2160: if (setp == NULL)
1.205 djm 2161: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 2162: if ((r = ssh_packet_write_poll(ssh)) != 0) {
2163: free(setp);
1.215 djm 2164: return r;
1.216 gsoares 2165: }
1.201 markus 2166: while (ssh_packet_have_data_to_write(ssh)) {
2167: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 2168: NFDBITS) * sizeof(fd_mask));
1.201 markus 2169: FD_SET(state->connection_out, setp);
1.154 dtucker 2170:
1.201 markus 2171: if (state->packet_timeout_ms > 0) {
2172: ms_remain = state->packet_timeout_ms;
1.154 dtucker 2173: timeoutp = &timeout;
2174: }
2175: for (;;) {
1.201 markus 2176: if (state->packet_timeout_ms != -1) {
1.154 dtucker 2177: ms_to_timeval(&timeout, ms_remain);
2178: gettimeofday(&start, NULL);
2179: }
1.201 markus 2180: if ((ret = select(state->connection_out + 1,
1.161 andreas 2181: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 2182: break;
1.161 andreas 2183: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 2184: break;
1.201 markus 2185: if (state->packet_timeout_ms == -1)
1.154 dtucker 2186: continue;
2187: ms_subtract_diff(&start, &ms_remain);
2188: if (ms_remain <= 0) {
2189: ret = 0;
2190: break;
2191: }
2192: }
2193: if (ret == 0) {
1.205 djm 2194: free(setp);
2195: return SSH_ERR_CONN_TIMEOUT;
2196: }
2197: if ((r = ssh_packet_write_poll(ssh)) != 0) {
2198: free(setp);
2199: return r;
1.154 dtucker 2200: }
1.14 markus 2201: }
1.186 djm 2202: free(setp);
1.205 djm 2203: return 0;
1.1 deraadt 2204: }
2205:
2206: /* Returns true if there is buffered data to write to the connection. */
2207:
1.2 provos 2208: int
1.201 markus 2209: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 2210: {
1.201 markus 2211: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 2212: }
2213:
2214: /* Returns true if there is not too much data to write to the connection. */
2215:
1.2 provos 2216: int
1.201 markus 2217: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 2218: {
1.201 markus 2219: if (ssh->state->interactive_mode)
2220: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 2221: else
1.201 markus 2222: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 2223: }
2224:
1.201 markus 2225: void
2226: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 2227: {
1.201 markus 2228: if (!ssh_packet_connection_is_on_socket(ssh))
1.101 markus 2229: return;
1.201 markus 2230: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 2231: case AF_INET:
2232: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 2233: if (setsockopt(ssh->state->connection_in,
1.173 djm 2234: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
2235: error("setsockopt IP_TOS %d: %.100s:",
2236: tos, strerror(errno));
2237: break;
2238: case AF_INET6:
2239: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 2240: if (setsockopt(ssh->state->connection_in,
1.173 djm 2241: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2242: error("setsockopt IPV6_TCLASS %d: %.100s:",
2243: tos, strerror(errno));
2244: break;
2245: }
1.101 markus 2246: }
2247:
1.1 deraadt 2248: /* Informs that the current session is interactive. Sets IP flags for that. */
2249:
1.2 provos 2250: void
1.201 markus 2251: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2252: {
1.201 markus 2253: struct session_state *state = ssh->state;
2254:
2255: if (state->set_interactive_called)
1.43 markus 2256: return;
1.201 markus 2257: state->set_interactive_called = 1;
1.1 deraadt 2258:
1.14 markus 2259: /* Record that we are in interactive mode. */
1.201 markus 2260: state->interactive_mode = interactive;
1.1 deraadt 2261:
1.19 markus 2262: /* Only set socket options if using a socket. */
1.201 markus 2263: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2264: return;
1.201 markus 2265: set_nodelay(state->connection_in);
2266: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2267: qos_bulk);
1.1 deraadt 2268: }
2269:
2270: /* Returns true if the current connection is interactive. */
2271:
1.2 provos 2272: int
1.201 markus 2273: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2274: {
1.201 markus 2275: return ssh->state->interactive_mode;
1.12 markus 2276: }
2277:
1.113 deraadt 2278: int
1.201 markus 2279: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2280: {
1.201 markus 2281: struct session_state *state = ssh->state;
2282:
2283: if (state->set_maxsize_called) {
1.106 itojun 2284: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2285: state->max_packet_size, s);
1.14 markus 2286: return -1;
2287: }
2288: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2289: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2290: return -1;
2291: }
1.201 markus 2292: state->set_maxsize_called = 1;
1.66 markus 2293: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2294: state->max_packet_size = s;
1.14 markus 2295: return s;
1.53 markus 2296: }
2297:
1.161 andreas 2298: int
1.201 markus 2299: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2300: {
1.201 markus 2301: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2302: }
2303:
2304: void
1.201 markus 2305: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2306: {
1.201 markus 2307: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2308: }
2309:
2310: u_int
1.201 markus 2311: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2312: {
1.201 markus 2313: return ssh->state->max_packet_size;
1.71 markus 2314: }
2315:
1.53 markus 2316: /*
2317: * 9.2. Ignored Data Message
1.61 markus 2318: *
1.53 markus 2319: * byte SSH_MSG_IGNORE
2320: * string data
1.61 markus 2321: *
1.53 markus 2322: * All implementations MUST understand (and ignore) this message at any
2323: * time (after receiving the protocol version). No implementation is
2324: * required to send them. This message can be used as an additional
2325: * protection measure against advanced traffic analysis techniques.
2326: */
1.54 markus 2327: void
1.201 markus 2328: ssh_packet_send_ignore(struct ssh *ssh, int nbytes)
1.54 markus 2329: {
1.115 avsm 2330: u_int32_t rnd = 0;
1.201 markus 2331: int r, i;
1.54 markus 2332:
1.201 markus 2333: if ((r = sshpkt_start(ssh, compat20 ?
2334: SSH2_MSG_IGNORE : SSH_MSG_IGNORE)) != 0 ||
2335: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2336: fatal("%s: %s", __func__, ssh_err(r));
1.75 deraadt 2337: for (i = 0; i < nbytes; i++) {
1.53 markus 2338: if (i % 4 == 0)
1.115 avsm 2339: rnd = arc4random();
1.201 markus 2340: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2341: fatal("%s: %s", __func__, ssh_err(r));
1.115 avsm 2342: rnd >>= 8;
1.53 markus 2343: }
1.105 markus 2344: }
2345:
2346: void
1.224 dtucker 2347: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, time_t seconds)
1.105 markus 2348: {
1.224 dtucker 2349: debug3("rekey after %llu bytes, %d seconds", (unsigned long long)bytes,
1.184 dtucker 2350: (int)seconds);
1.201 markus 2351: ssh->state->rekey_limit = bytes;
2352: ssh->state->rekey_interval = seconds;
1.184 dtucker 2353: }
2354:
2355: time_t
1.201 markus 2356: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2357: {
2358: time_t seconds;
2359:
1.201 markus 2360: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2361: monotime();
1.185 dtucker 2362: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2363: }
2364:
2365: void
1.201 markus 2366: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2367: {
1.201 markus 2368: ssh->state->server_side = 1;
1.118 markus 2369: }
2370:
2371: void
1.201 markus 2372: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2373: {
1.201 markus 2374: ssh->state->after_authentication = 1;
1.161 andreas 2375: }
2376:
2377: void *
1.201 markus 2378: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2379: {
1.201 markus 2380: return (void *)ssh->state->input;
1.161 andreas 2381: }
2382:
2383: void *
1.201 markus 2384: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2385: {
1.201 markus 2386: return (void *)ssh->state->output;
1.166 andreas 2387: }
2388:
1.196 markus 2389: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2390: static int
2391: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2392: {
1.201 markus 2393: struct sshcomp *comp;
2394: int r, mode;
1.196 markus 2395:
2396: debug("%s: called", __func__);
2397: /* This was set in net child, but is not visible in user child */
1.201 markus 2398: ssh->state->after_authentication = 1;
2399: ssh->state->rekeying = 0;
1.196 markus 2400: for (mode = 0; mode < MODE_MAX; mode++) {
1.201 markus 2401: if (ssh->state->newkeys[mode] == NULL)
1.196 markus 2402: continue;
1.201 markus 2403: comp = &ssh->state->newkeys[mode]->comp;
2404: if (comp && comp->enabled &&
2405: (r = ssh_packet_init_compression(ssh)) != 0)
2406: return r;
2407: }
2408: return 0;
2409: }
2410:
2411: /* Packet state (de-)serialization for privsep */
2412:
2413: /* turn kex into a blob for packet state serialization */
2414: static int
2415: kex_to_blob(struct sshbuf *m, struct kex *kex)
2416: {
2417: int r;
2418:
2419: if ((r = sshbuf_put_string(m, kex->session_id,
2420: kex->session_id_len)) != 0 ||
2421: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2422: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2423: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2424: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2425: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2426: (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2427: (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2428: (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2429: return r;
2430: return 0;
2431: }
2432:
2433: /* turn key exchange results into a blob for packet state serialization */
2434: static int
2435: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2436: {
2437: struct sshbuf *b;
2438: struct sshcipher_ctx *cc;
2439: struct sshcomp *comp;
2440: struct sshenc *enc;
2441: struct sshmac *mac;
2442: struct newkeys *newkey;
2443: int r;
2444:
2445: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2446: return SSH_ERR_INTERNAL_ERROR;
2447: enc = &newkey->enc;
2448: mac = &newkey->mac;
2449: comp = &newkey->comp;
2450: cc = (mode == MODE_OUT) ? &ssh->state->send_context :
2451: &ssh->state->receive_context;
2452: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2453: return r;
2454: if ((b = sshbuf_new()) == NULL)
2455: return SSH_ERR_ALLOC_FAIL;
2456: /* The cipher struct is constant and shared, you export pointer */
2457: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2458: (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2459: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2460: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2461: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2462: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2463: goto out;
2464: if (cipher_authlen(enc->cipher) == 0) {
2465: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2466: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2467: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2468: goto out;
2469: }
2470: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2471: (r = sshbuf_put_u32(b, comp->enabled)) != 0 ||
2472: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2473: goto out;
2474: r = sshbuf_put_stringb(m, b);
2475: out:
1.221 mmcc 2476: sshbuf_free(b);
1.201 markus 2477: return r;
2478: }
2479:
2480: /* serialize packet state into a blob */
2481: int
2482: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2483: {
2484: struct session_state *state = ssh->state;
2485: u_char *p;
2486: size_t slen, rlen;
2487: int r, ssh1cipher;
2488:
2489: if (!compat20) {
2490: ssh1cipher = cipher_get_number(state->receive_context.cipher);
2491: slen = cipher_get_keyiv_len(&state->send_context);
2492: rlen = cipher_get_keyiv_len(&state->receive_context);
2493: if ((r = sshbuf_put_u32(m, state->remote_protocol_flags)) != 0 ||
2494: (r = sshbuf_put_u32(m, ssh1cipher)) != 0 ||
2495: (r = sshbuf_put_string(m, state->ssh1_key, state->ssh1_keylen)) != 0 ||
2496: (r = sshbuf_put_u32(m, slen)) != 0 ||
2497: (r = sshbuf_reserve(m, slen, &p)) != 0 ||
2498: (r = cipher_get_keyiv(&state->send_context, p, slen)) != 0 ||
2499: (r = sshbuf_put_u32(m, rlen)) != 0 ||
2500: (r = sshbuf_reserve(m, rlen, &p)) != 0 ||
2501: (r = cipher_get_keyiv(&state->receive_context, p, rlen)) != 0)
2502: return r;
2503: } else {
2504: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2505: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2506: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
1.224 dtucker 2507: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
1.208 markus 2508: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
1.201 markus 2509: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2510: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2511: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2512: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2513: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2514: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2515: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
2516: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0)
2517: return r;
2518: }
2519:
2520: slen = cipher_get_keycontext(&state->send_context, NULL);
2521: rlen = cipher_get_keycontext(&state->receive_context, NULL);
2522: if ((r = sshbuf_put_u32(m, slen)) != 0 ||
2523: (r = sshbuf_reserve(m, slen, &p)) != 0)
2524: return r;
2525: if (cipher_get_keycontext(&state->send_context, p) != (int)slen)
2526: return SSH_ERR_INTERNAL_ERROR;
2527: if ((r = sshbuf_put_u32(m, rlen)) != 0 ||
2528: (r = sshbuf_reserve(m, rlen, &p)) != 0)
2529: return r;
2530: if (cipher_get_keycontext(&state->receive_context, p) != (int)rlen)
2531: return SSH_ERR_INTERNAL_ERROR;
2532:
2533: if ((r = ssh_packet_get_compress_state(m, ssh)) != 0 ||
2534: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2535: (r = sshbuf_put_stringb(m, state->output)) != 0)
2536: return r;
2537:
2538: return 0;
2539: }
2540:
2541: /* restore key exchange results from blob for packet state de-serialization */
2542: static int
2543: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2544: {
2545: struct sshbuf *b = NULL;
2546: struct sshcomp *comp;
2547: struct sshenc *enc;
2548: struct sshmac *mac;
2549: struct newkeys *newkey = NULL;
2550: size_t keylen, ivlen, maclen;
2551: int r;
2552:
2553: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2554: r = SSH_ERR_ALLOC_FAIL;
2555: goto out;
2556: }
2557: if ((r = sshbuf_froms(m, &b)) != 0)
2558: goto out;
2559: #ifdef DEBUG_PK
2560: sshbuf_dump(b, stderr);
2561: #endif
2562: enc = &newkey->enc;
2563: mac = &newkey->mac;
2564: comp = &newkey->comp;
2565:
2566: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2567: (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2568: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2569: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2570: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2571: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2572: goto out;
2573: if (cipher_authlen(enc->cipher) == 0) {
2574: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2575: goto out;
2576: if ((r = mac_setup(mac, mac->name)) != 0)
2577: goto out;
2578: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2579: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2580: goto out;
2581: if (maclen > mac->key_len) {
2582: r = SSH_ERR_INVALID_FORMAT;
2583: goto out;
2584: }
2585: mac->key_len = maclen;
2586: }
2587: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2588: (r = sshbuf_get_u32(b, (u_int *)&comp->enabled)) != 0 ||
2589: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2590: goto out;
2591: if (enc->name == NULL ||
2592: cipher_by_name(enc->name) != enc->cipher) {
2593: r = SSH_ERR_INVALID_FORMAT;
2594: goto out;
2595: }
2596: if (sshbuf_len(b) != 0) {
2597: r = SSH_ERR_INVALID_FORMAT;
2598: goto out;
2599: }
2600: enc->key_len = keylen;
2601: enc->iv_len = ivlen;
2602: ssh->kex->newkeys[mode] = newkey;
2603: newkey = NULL;
2604: r = 0;
2605: out:
1.219 mmcc 2606: free(newkey);
1.221 mmcc 2607: sshbuf_free(b);
1.201 markus 2608: return r;
2609: }
2610:
2611: /* restore kex from blob for packet state de-serialization */
2612: static int
2613: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2614: {
2615: struct kex *kex;
2616: int r;
2617:
2618: if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2619: (kex->my = sshbuf_new()) == NULL ||
2620: (kex->peer = sshbuf_new()) == NULL) {
2621: r = SSH_ERR_ALLOC_FAIL;
2622: goto out;
2623: }
2624: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2625: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2626: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2627: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2628: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2629: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2630: (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2631: (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2632: (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2633: goto out;
2634: kex->server = 1;
2635: kex->done = 1;
2636: r = 0;
2637: out:
2638: if (r != 0 || kexp == NULL) {
2639: if (kex != NULL) {
1.221 mmcc 2640: sshbuf_free(kex->my);
2641: sshbuf_free(kex->peer);
1.201 markus 2642: free(kex);
2643: }
2644: if (kexp != NULL)
2645: *kexp = NULL;
2646: } else {
2647: *kexp = kex;
2648: }
2649: return r;
2650: }
2651:
2652: /*
2653: * Restore packet state from content of blob 'm' (de-serialization).
2654: * Note that 'm' will be partially consumed on parsing or any other errors.
2655: */
2656: int
2657: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2658: {
2659: struct session_state *state = ssh->state;
2660: const u_char *ssh1key, *ivin, *ivout, *keyin, *keyout, *input, *output;
2661: size_t ssh1keylen, rlen, slen, ilen, olen;
2662: int r;
2663: u_int ssh1cipher = 0;
2664:
2665: if (!compat20) {
2666: if ((r = sshbuf_get_u32(m, &state->remote_protocol_flags)) != 0 ||
2667: (r = sshbuf_get_u32(m, &ssh1cipher)) != 0 ||
2668: (r = sshbuf_get_string_direct(m, &ssh1key, &ssh1keylen)) != 0 ||
2669: (r = sshbuf_get_string_direct(m, &ivout, &slen)) != 0 ||
2670: (r = sshbuf_get_string_direct(m, &ivin, &rlen)) != 0)
2671: return r;
2672: if (ssh1cipher > INT_MAX)
2673: return SSH_ERR_KEY_UNKNOWN_CIPHER;
2674: ssh_packet_set_encryption_key(ssh, ssh1key, ssh1keylen,
2675: (int)ssh1cipher);
2676: if (cipher_get_keyiv_len(&state->send_context) != (int)slen ||
2677: cipher_get_keyiv_len(&state->receive_context) != (int)rlen)
2678: return SSH_ERR_INVALID_FORMAT;
2679: if ((r = cipher_set_keyiv(&state->send_context, ivout)) != 0 ||
2680: (r = cipher_set_keyiv(&state->receive_context, ivin)) != 0)
2681: return r;
2682: } else {
2683: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2684: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2685: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
1.224 dtucker 2686: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
1.208 markus 2687: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
1.201 markus 2688: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2689: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2690: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2691: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2692: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2693: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2694: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2695: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2696: return r;
1.208 markus 2697: /*
2698: * We set the time here so that in post-auth privsep slave we
2699: * count from the completion of the authentication.
2700: */
2701: state->rekey_time = monotime();
1.201 markus 2702: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2703: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2704: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2705: return r;
2706: }
2707: if ((r = sshbuf_get_string_direct(m, &keyout, &slen)) != 0 ||
2708: (r = sshbuf_get_string_direct(m, &keyin, &rlen)) != 0)
2709: return r;
2710: if (cipher_get_keycontext(&state->send_context, NULL) != (int)slen ||
2711: cipher_get_keycontext(&state->receive_context, NULL) != (int)rlen)
2712: return SSH_ERR_INVALID_FORMAT;
2713: cipher_set_keycontext(&state->send_context, keyout);
2714: cipher_set_keycontext(&state->receive_context, keyin);
2715:
2716: if ((r = ssh_packet_set_compress_state(ssh, m)) != 0 ||
2717: (r = ssh_packet_set_postauth(ssh)) != 0)
2718: return r;
2719:
2720: sshbuf_reset(state->input);
2721: sshbuf_reset(state->output);
2722: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2723: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2724: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2725: (r = sshbuf_put(state->output, output, olen)) != 0)
2726: return r;
2727:
2728: if (sshbuf_len(m))
2729: return SSH_ERR_INVALID_FORMAT;
2730: debug3("%s: done", __func__);
2731: return 0;
2732: }
2733:
2734: /* NEW API */
2735:
2736: /* put data to the outgoing packet */
2737:
2738: int
2739: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2740: {
2741: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2742: }
2743:
2744: int
2745: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2746: {
2747: return sshbuf_putb(ssh->state->outgoing_packet, b);
2748: }
2749:
2750: int
2751: sshpkt_put_u8(struct ssh *ssh, u_char val)
2752: {
2753: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2754: }
2755:
2756: int
2757: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2758: {
2759: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2760: }
2761:
2762: int
2763: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2764: {
2765: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2766: }
2767:
2768: int
2769: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2770: {
2771: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2772: }
2773:
2774: int
2775: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2776: {
2777: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2778: }
2779:
2780: int
2781: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2782: {
2783: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2784: }
2785:
1.211 djm 2786: #ifdef WITH_OPENSSL
1.201 markus 2787: int
2788: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2789: {
2790: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2791: }
2792:
1.211 djm 2793: #ifdef WITH_SSH1
1.201 markus 2794: int
2795: sshpkt_put_bignum1(struct ssh *ssh, const BIGNUM *v)
2796: {
2797: return sshbuf_put_bignum1(ssh->state->outgoing_packet, v);
2798: }
1.211 djm 2799: #endif /* WITH_SSH1 */
1.201 markus 2800:
2801: int
2802: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2803: {
2804: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2805: }
1.211 djm 2806: #endif /* WITH_OPENSSL */
1.201 markus 2807:
2808: /* fetch data from the incoming packet */
2809:
2810: int
2811: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2812: {
2813: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2814: }
2815:
2816: int
2817: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2818: {
2819: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2820: }
2821:
2822: int
2823: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2824: {
2825: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2826: }
2827:
2828: int
2829: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2830: {
2831: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2832: }
2833:
2834: int
2835: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2836: {
2837: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2838: }
2839:
2840: int
2841: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2842: {
2843: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2844: }
2845:
2846: int
2847: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2848: {
2849: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2850: }
2851:
1.211 djm 2852: #ifdef WITH_OPENSSL
1.201 markus 2853: int
2854: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2855: {
2856: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2857: }
2858:
1.211 djm 2859: #ifdef WITH_SSH1
1.201 markus 2860: int
2861: sshpkt_get_bignum1(struct ssh *ssh, BIGNUM *v)
2862: {
2863: return sshbuf_get_bignum1(ssh->state->incoming_packet, v);
2864: }
1.211 djm 2865: #endif /* WITH_SSH1 */
1.201 markus 2866:
2867: int
2868: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2869: {
2870: return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2871: }
1.211 djm 2872: #endif /* WITH_OPENSSL */
1.201 markus 2873:
2874: int
2875: sshpkt_get_end(struct ssh *ssh)
2876: {
2877: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2878: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2879: return 0;
2880: }
2881:
2882: const u_char *
2883: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2884: {
2885: if (lenp != NULL)
2886: *lenp = sshbuf_len(ssh->state->incoming_packet);
2887: return sshbuf_ptr(ssh->state->incoming_packet);
2888: }
2889:
2890: /* start a new packet */
2891:
2892: int
2893: sshpkt_start(struct ssh *ssh, u_char type)
2894: {
2895: u_char buf[9];
2896: int len;
2897:
2898: DBG(debug("packet_start[%d]", type));
2899: len = compat20 ? 6 : 9;
2900: memset(buf, 0, len - 1);
2901: buf[len - 1] = type;
2902: sshbuf_reset(ssh->state->outgoing_packet);
2903: return sshbuf_put(ssh->state->outgoing_packet, buf, len);
2904: }
2905:
2906: /* send it */
2907:
2908: int
2909: sshpkt_send(struct ssh *ssh)
2910: {
2911: if (compat20)
2912: return ssh_packet_send2(ssh);
2913: else
2914: return ssh_packet_send1(ssh);
2915: }
2916:
2917: int
2918: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2919: {
2920: char buf[1024];
2921: va_list args;
2922: int r;
2923:
2924: va_start(args, fmt);
2925: vsnprintf(buf, sizeof(buf), fmt, args);
2926: va_end(args);
2927:
2928: if (compat20) {
2929: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2930: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2931: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2932: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2933: (r = sshpkt_send(ssh)) != 0)
2934: return r;
2935: } else {
2936: if ((r = sshpkt_start(ssh, SSH_MSG_DISCONNECT)) != 0 ||
2937: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2938: (r = sshpkt_send(ssh)) != 0)
2939: return r;
1.166 andreas 2940: }
1.201 markus 2941: return 0;
2942: }
2943:
2944: /* roundup current message to pad bytes */
2945: int
2946: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2947: {
2948: ssh->state->extra_pad = pad;
2949: return 0;
1.1 deraadt 2950: }
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