Annotation of src/usr.bin/ssh/packet.c, Revision 1.258
1.258 ! deraadt 1: /* $OpenBSD: packet.c,v 1.257 2017/05/31 08:09:45 markus Exp $ */
1.1 deraadt 2: /*
1.15 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.35 deraadt 6: * This file contains code implementing the packet protocol and communication
7: * with the other side. This same code is used both on client and server side.
1.29 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
1.29 markus 14: *
1.25 markus 15: *
16: * SSH2 packet format added by Markus Friedl.
1.69 markus 17: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.25 markus 18: *
1.35 deraadt 19: * Redistribution and use in source and binary forms, with or without
20: * modification, are permitted provided that the following conditions
21: * are met:
22: * 1. Redistributions of source code must retain the above copyright
23: * notice, this list of conditions and the following disclaimer.
24: * 2. Redistributions in binary form must reproduce the above copyright
25: * notice, this list of conditions and the following disclaimer in the
26: * documentation and/or other materials provided with the distribution.
27: *
28: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15 deraadt 38: */
1.1 deraadt 39:
1.142 deraadt 40: #include <sys/types.h>
1.105 markus 41: #include <sys/queue.h>
1.132 stevesk 42: #include <sys/socket.h>
1.138 stevesk 43: #include <sys/time.h>
1.132 stevesk 44: #include <netinet/in.h>
1.121 stevesk 45: #include <netinet/ip.h>
1.134 stevesk 46:
1.135 stevesk 47: #include <errno.h>
1.230 djm 48: #include <netdb.h>
1.134 stevesk 49: #include <stdarg.h>
1.141 stevesk 50: #include <stdio.h>
1.140 stevesk 51: #include <stdlib.h>
1.137 stevesk 52: #include <string.h>
1.136 stevesk 53: #include <unistd.h>
1.203 deraadt 54: #include <limits.h>
1.142 deraadt 55: #include <signal.h>
1.184 dtucker 56: #include <time.h>
1.1 deraadt 57:
1.201 markus 58: #include <zlib.h>
59:
60: #include "buffer.h" /* typedefs XXX */
61: #include "key.h" /* typedefs XXX */
62:
1.1 deraadt 63: #include "xmalloc.h"
64: #include "crc32.h"
1.25 markus 65: #include "compat.h"
66: #include "ssh2.h"
1.37 markus 67: #include "cipher.h"
1.201 markus 68: #include "sshkey.h"
1.25 markus 69: #include "kex.h"
1.200 markus 70: #include "digest.h"
1.50 markus 71: #include "mac.h"
1.46 markus 72: #include "log.h"
73: #include "canohost.h"
1.87 stevesk 74: #include "misc.h"
1.198 millert 75: #include "channels.h"
1.95 markus 76: #include "ssh.h"
1.201 markus 77: #include "packet.h"
1.197 djm 78: #include "ssherr.h"
1.201 markus 79: #include "sshbuf.h"
1.25 markus 80:
81: #ifdef PACKET_DEBUG
82: #define DBG(x) x
83: #else
84: #define DBG(x)
85: #endif
86:
1.159 markus 87: #define PACKET_MAX_SIZE (256 * 1024)
88:
1.161 andreas 89: struct packet_state {
90: u_int32_t seqnr;
91: u_int32_t packets;
92: u_int64_t blocks;
93: u_int64_t bytes;
94: };
95:
96: struct packet {
97: TAILQ_ENTRY(packet) next;
98: u_char type;
1.201 markus 99: struct sshbuf *payload;
1.161 andreas 100: };
101:
102: struct session_state {
103: /*
104: * This variable contains the file descriptors used for
105: * communicating with the other side. connection_in is used for
106: * reading; connection_out for writing. These can be the same
107: * descriptor, in which case it is assumed to be a socket.
108: */
109: int connection_in;
110: int connection_out;
111:
112: /* Protocol flags for the remote side. */
113: u_int remote_protocol_flags;
1.1 deraadt 114:
1.161 andreas 115: /* Encryption context for receiving data. Only used for decryption. */
1.235 djm 116: struct sshcipher_ctx *receive_context;
1.1 deraadt 117:
1.161 andreas 118: /* Encryption context for sending data. Only used for encryption. */
1.235 djm 119: struct sshcipher_ctx *send_context;
1.14 markus 120:
1.161 andreas 121: /* Buffer for raw input data from the socket. */
1.201 markus 122: struct sshbuf *input;
1.1 deraadt 123:
1.161 andreas 124: /* Buffer for raw output data going to the socket. */
1.201 markus 125: struct sshbuf *output;
1.1 deraadt 126:
1.161 andreas 127: /* Buffer for the partial outgoing packet being constructed. */
1.201 markus 128: struct sshbuf *outgoing_packet;
1.1 deraadt 129:
1.161 andreas 130: /* Buffer for the incoming packet currently being processed. */
1.201 markus 131: struct sshbuf *incoming_packet;
1.1 deraadt 132:
1.161 andreas 133: /* Scratch buffer for packet compression/decompression. */
1.201 markus 134: struct sshbuf *compression_buffer;
135:
136: /* Incoming/outgoing compression dictionaries */
137: z_stream compression_in_stream;
138: z_stream compression_out_stream;
139: int compression_in_started;
140: int compression_out_started;
141: int compression_in_failures;
142: int compression_out_failures;
1.1 deraadt 143:
1.161 andreas 144: /*
145: * Flag indicating whether packet compression/decompression is
146: * enabled.
147: */
148: int packet_compression;
1.1 deraadt 149:
1.161 andreas 150: /* default maximum packet size */
151: u_int max_packet_size;
1.1 deraadt 152:
1.161 andreas 153: /* Flag indicating whether this module has been initialized. */
154: int initialized;
1.12 markus 155:
1.161 andreas 156: /* Set to true if the connection is interactive. */
157: int interactive_mode;
1.1 deraadt 158:
1.161 andreas 159: /* Set to true if we are the server side. */
160: int server_side;
1.1 deraadt 161:
1.161 andreas 162: /* Set to true if we are authenticated. */
163: int after_authentication;
1.118 markus 164:
1.161 andreas 165: int keep_alive_timeouts;
1.118 markus 166:
1.161 andreas 167: /* The maximum time that we will wait to send or receive a packet */
168: int packet_timeout_ms;
1.151 dtucker 169:
1.161 andreas 170: /* Session key information for Encryption and MAC */
1.201 markus 171: struct newkeys *newkeys[MODE_MAX];
1.161 andreas 172: struct packet_state p_read, p_send;
1.154 dtucker 173:
1.184 dtucker 174: /* Volume-based rekeying */
1.224 dtucker 175: u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
1.105 markus 176:
1.184 dtucker 177: /* Time-based rekeying */
1.208 markus 178: u_int32_t rekey_interval; /* how often in seconds */
1.184 dtucker 179: time_t rekey_time; /* time of last rekeying */
180:
1.161 andreas 181: /* roundup current message to extra_pad bytes */
182: u_char extra_pad;
1.95 markus 183:
1.161 andreas 184: /* XXX discard incoming data after MAC error */
185: u_int packet_discard;
1.234 markus 186: size_t packet_discard_mac_already;
1.201 markus 187: struct sshmac *packet_discard_mac;
1.71 markus 188:
1.161 andreas 189: /* Used in packet_read_poll2() */
190: u_int packlen;
1.159 markus 191:
1.165 andreas 192: /* Used in packet_send2 */
193: int rekeying;
194:
1.242 markus 195: /* Used in ssh_packet_send_mux() */
196: int mux;
197:
1.165 andreas 198: /* Used in packet_set_interactive */
199: int set_interactive_called;
200:
201: /* Used in packet_set_maxsize */
202: int set_maxsize_called;
203:
1.201 markus 204: /* One-off warning about weak ciphers */
205: int cipher_warning_done;
206:
1.243 djm 207: /* Hook for fuzzing inbound packets */
208: ssh_packet_hook_fn *hook_in;
209: void *hook_in_ctx;
210:
1.161 andreas 211: TAILQ_HEAD(, packet) outgoing;
1.105 markus 212: };
1.161 andreas 213:
1.201 markus 214: struct ssh *
215: ssh_alloc_session_state(void)
1.161 andreas 216: {
1.201 markus 217: struct ssh *ssh = NULL;
218: struct session_state *state = NULL;
1.161 andreas 219:
1.201 markus 220: if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
221: (state = calloc(1, sizeof(*state))) == NULL ||
222: (state->input = sshbuf_new()) == NULL ||
223: (state->output = sshbuf_new()) == NULL ||
224: (state->outgoing_packet = sshbuf_new()) == NULL ||
225: (state->incoming_packet = sshbuf_new()) == NULL)
226: goto fail;
227: TAILQ_INIT(&state->outgoing);
1.202 markus 228: TAILQ_INIT(&ssh->private_keys);
229: TAILQ_INIT(&ssh->public_keys);
1.201 markus 230: state->connection_in = -1;
231: state->connection_out = -1;
232: state->max_packet_size = 32768;
233: state->packet_timeout_ms = -1;
234: state->p_send.packets = state->p_read.packets = 0;
235: state->initialized = 1;
236: /*
237: * ssh_packet_send2() needs to queue packets until
238: * we've done the initial key exchange.
239: */
240: state->rekeying = 1;
241: ssh->state = state;
242: return ssh;
243: fail:
244: if (state) {
245: sshbuf_free(state->input);
246: sshbuf_free(state->output);
247: sshbuf_free(state->incoming_packet);
248: sshbuf_free(state->outgoing_packet);
249: free(state);
250: }
251: free(ssh);
252: return NULL;
1.161 andreas 253: }
1.105 markus 254:
1.243 djm 255: void
256: ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
257: {
258: ssh->state->hook_in = hook;
259: ssh->state->hook_in_ctx = ctx;
260: }
261:
1.228 djm 262: /* Returns nonzero if rekeying is in progress */
263: int
264: ssh_packet_is_rekeying(struct ssh *ssh)
265: {
1.249 djm 266: return ssh->state->rekeying ||
267: (ssh->kex != NULL && ssh->kex->done == 0);
1.228 djm 268: }
269:
1.16 markus 270: /*
1.253 naddy 271: * Sets the descriptors used for communication.
1.16 markus 272: */
1.201 markus 273: struct ssh *
274: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1 deraadt 275: {
1.201 markus 276: struct session_state *state;
277: const struct sshcipher *none = cipher_by_name("none");
1.197 djm 278: int r;
1.97 deraadt 279:
1.205 djm 280: if (none == NULL) {
281: error("%s: cannot load cipher 'none'", __func__);
282: return NULL;
283: }
1.201 markus 284: if (ssh == NULL)
285: ssh = ssh_alloc_session_state();
1.205 djm 286: if (ssh == NULL) {
287: error("%s: cound not allocate state", __func__);
288: return NULL;
289: }
1.201 markus 290: state = ssh->state;
291: state->connection_in = fd_in;
292: state->connection_out = fd_out;
293: if ((r = cipher_init(&state->send_context, none,
1.197 djm 294: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201 markus 295: (r = cipher_init(&state->receive_context, none,
1.205 djm 296: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
297: error("%s: cipher_init failed: %s", __func__, ssh_err(r));
1.230 djm 298: free(ssh); /* XXX need ssh_free_session_state? */
1.205 djm 299: return NULL;
300: }
1.201 markus 301: state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
1.207 djm 302: /*
303: * Cache the IP address of the remote connection for use in error
304: * messages that might be generated after the connection has closed.
305: */
306: (void)ssh_remote_ipaddr(ssh);
1.201 markus 307: return ssh;
1.1 deraadt 308: }
309:
1.154 dtucker 310: void
1.201 markus 311: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 312: {
1.201 markus 313: struct session_state *state = ssh->state;
314:
1.174 djm 315: if (timeout <= 0 || count <= 0) {
1.201 markus 316: state->packet_timeout_ms = -1;
1.154 dtucker 317: return;
318: }
319: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 320: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 321: else
1.201 markus 322: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 323: }
324:
1.242 markus 325: void
326: ssh_packet_set_mux(struct ssh *ssh)
327: {
328: ssh->state->mux = 1;
329: ssh->state->rekeying = 0;
330: }
331:
332: int
333: ssh_packet_get_mux(struct ssh *ssh)
334: {
335: return ssh->state->mux;
336: }
337:
1.201 markus 338: int
1.245 djm 339: ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
340: {
341: va_list args;
342: int r;
343:
344: free(ssh->log_preamble);
345: if (fmt == NULL)
346: ssh->log_preamble = NULL;
347: else {
348: va_start(args, fmt);
349: r = vasprintf(&ssh->log_preamble, fmt, args);
350: va_end(args);
351: if (r < 0 || ssh->log_preamble == NULL)
352: return SSH_ERR_ALLOC_FAIL;
353: }
354: return 0;
355: }
356:
357: int
1.201 markus 358: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 359: {
1.201 markus 360: struct session_state *state = ssh->state;
361: int r;
362:
363: if (state->packet_discard_mac) {
1.159 markus 364: char buf[1024];
1.234 markus 365: size_t dlen = PACKET_MAX_SIZE;
1.201 markus 366:
1.234 markus 367: if (dlen > state->packet_discard_mac_already)
368: dlen -= state->packet_discard_mac_already;
1.159 markus 369: memset(buf, 'a', sizeof(buf));
1.234 markus 370: while (sshbuf_len(state->incoming_packet) < dlen)
1.201 markus 371: if ((r = sshbuf_put(state->incoming_packet, buf,
372: sizeof(buf))) != 0)
373: return r;
374: (void) mac_compute(state->packet_discard_mac,
375: state->p_read.seqnr,
1.234 markus 376: sshbuf_ptr(state->incoming_packet), dlen,
1.201 markus 377: NULL, 0);
1.159 markus 378: }
1.220 djm 379: logit("Finished discarding for %.200s port %d",
380: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 381: return SSH_ERR_MAC_INVALID;
1.159 markus 382: }
383:
1.201 markus 384: static int
385: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
1.234 markus 386: struct sshmac *mac, size_t mac_already, u_int discard)
1.159 markus 387: {
1.201 markus 388: struct session_state *state = ssh->state;
389: int r;
390:
391: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
392: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
393: return r;
394: return SSH_ERR_MAC_INVALID;
395: }
1.234 markus 396: /*
397: * Record number of bytes over which the mac has already
398: * been computed in order to minimize timing attacks.
399: */
400: if (mac && mac->enabled) {
1.201 markus 401: state->packet_discard_mac = mac;
1.234 markus 402: state->packet_discard_mac_already = mac_already;
403: }
404: if (sshbuf_len(state->input) >= discard)
405: return ssh_packet_stop_discard(ssh);
1.201 markus 406: state->packet_discard = discard - sshbuf_len(state->input);
407: return 0;
1.159 markus 408: }
409:
1.19 markus 410: /* Returns 1 if remote host is connected via socket, 0 if not. */
411:
412: int
1.201 markus 413: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 414: {
1.201 markus 415: struct session_state *state = ssh->state;
1.19 markus 416: struct sockaddr_storage from, to;
417: socklen_t fromlen, tolen;
418:
1.230 djm 419: if (state->connection_in == -1 || state->connection_out == -1)
420: return 0;
421:
1.19 markus 422: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 423: if (state->connection_in == state->connection_out)
1.19 markus 424: return 1;
425: fromlen = sizeof(from);
426: memset(&from, 0, sizeof(from));
1.201 markus 427: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.161 andreas 428: &fromlen) < 0)
1.19 markus 429: return 0;
430: tolen = sizeof(to);
431: memset(&to, 0, sizeof(to));
1.201 markus 432: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.161 andreas 433: &tolen) < 0)
1.19 markus 434: return 0;
435: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
436: return 0;
437: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
438: return 0;
439: return 1;
440: }
441:
1.91 markus 442: void
1.201 markus 443: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 444: {
1.201 markus 445: if (ibytes)
446: *ibytes = ssh->state->p_read.bytes;
447: if (obytes)
448: *obytes = ssh->state->p_send.bytes;
1.91 markus 449: }
1.125 deraadt 450:
1.91 markus 451: int
1.201 markus 452: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 453: {
454: struct sockaddr_storage to;
1.21 deraadt 455: socklen_t tolen = sizeof(to);
1.19 markus 456:
457: memset(&to, 0, sizeof(to));
1.201 markus 458: if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
1.161 andreas 459: &tolen) < 0)
1.19 markus 460: return 0;
1.173 djm 461: return to.ss_family;
1.19 markus 462: }
463:
1.1 deraadt 464: /* Sets the connection into non-blocking mode. */
465:
1.2 provos 466: void
1.201 markus 467: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 468: {
1.14 markus 469: /* Set the socket into non-blocking mode. */
1.201 markus 470: set_nonblock(ssh->state->connection_in);
1.14 markus 471:
1.201 markus 472: if (ssh->state->connection_out != ssh->state->connection_in)
473: set_nonblock(ssh->state->connection_out);
1.1 deraadt 474: }
475:
476: /* Returns the socket used for reading. */
477:
1.2 provos 478: int
1.201 markus 479: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 480: {
1.201 markus 481: return ssh->state->connection_in;
1.1 deraadt 482: }
483:
484: /* Returns the descriptor used for writing. */
485:
1.2 provos 486: int
1.201 markus 487: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 488: {
1.201 markus 489: return ssh->state->connection_out;
490: }
491:
492: /*
493: * Returns the IP-address of the remote host as a string. The returned
494: * string must not be freed.
495: */
496:
497: const char *
498: ssh_remote_ipaddr(struct ssh *ssh)
499: {
1.220 djm 500: const int sock = ssh->state->connection_in;
501:
1.201 markus 502: /* Check whether we have cached the ipaddr. */
1.220 djm 503: if (ssh->remote_ipaddr == NULL) {
504: if (ssh_packet_connection_is_on_socket(ssh)) {
505: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 djm 506: ssh->remote_port = get_peer_port(sock);
507: ssh->local_ipaddr = get_local_ipaddr(sock);
508: ssh->local_port = get_local_port(sock);
1.220 djm 509: } else {
510: ssh->remote_ipaddr = strdup("UNKNOWN");
1.230 djm 511: ssh->remote_port = 65535;
512: ssh->local_ipaddr = strdup("UNKNOWN");
513: ssh->local_port = 65535;
1.220 djm 514: }
515: }
1.201 markus 516: return ssh->remote_ipaddr;
1.1 deraadt 517: }
518:
1.220 djm 519: /* Returns the port number of the remote host. */
520:
521: int
522: ssh_remote_port(struct ssh *ssh)
523: {
524: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
525: return ssh->remote_port;
1.230 djm 526: }
527:
528: /*
529: * Returns the IP-address of the local host as a string. The returned
530: * string must not be freed.
531: */
532:
533: const char *
534: ssh_local_ipaddr(struct ssh *ssh)
535: {
536: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
537: return ssh->local_ipaddr;
538: }
539:
540: /* Returns the port number of the local host. */
541:
542: int
543: ssh_local_port(struct ssh *ssh)
544: {
545: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
546: return ssh->local_port;
1.220 djm 547: }
548:
1.1 deraadt 549: /* Closes the connection and clears and frees internal data structures. */
550:
1.257 markus 551: static void
552: ssh_packet_close_internal(struct ssh *ssh, int do_close)
1.1 deraadt 553: {
1.201 markus 554: struct session_state *state = ssh->state;
555: u_int mode;
556:
557: if (!state->initialized)
1.14 markus 558: return;
1.201 markus 559: state->initialized = 0;
1.257 markus 560: if (do_close) {
561: if (state->connection_in == state->connection_out) {
562: close(state->connection_out);
563: } else {
564: close(state->connection_in);
565: close(state->connection_out);
566: }
1.14 markus 567: }
1.201 markus 568: sshbuf_free(state->input);
569: sshbuf_free(state->output);
570: sshbuf_free(state->outgoing_packet);
571: sshbuf_free(state->incoming_packet);
1.257 markus 572: for (mode = 0; mode < MODE_MAX; mode++) {
573: kex_free_newkeys(state->newkeys[mode]); /* current keys */
574: state->newkeys[mode] = NULL;
575: ssh_clear_newkeys(ssh, mode); /* next keys */
576: }
577: /* comression state is in shared mem, so we can only release it once */
578: if (do_close && state->compression_buffer) {
1.201 markus 579: sshbuf_free(state->compression_buffer);
580: if (state->compression_out_started) {
581: z_streamp stream = &state->compression_out_stream;
582: debug("compress outgoing: "
583: "raw data %llu, compressed %llu, factor %.2f",
584: (unsigned long long)stream->total_in,
585: (unsigned long long)stream->total_out,
586: stream->total_in == 0 ? 0.0 :
587: (double) stream->total_out / stream->total_in);
588: if (state->compression_out_failures == 0)
589: deflateEnd(stream);
590: }
591: if (state->compression_in_started) {
592: z_streamp stream = &state->compression_out_stream;
593: debug("compress incoming: "
594: "raw data %llu, compressed %llu, factor %.2f",
595: (unsigned long long)stream->total_out,
596: (unsigned long long)stream->total_in,
597: stream->total_out == 0 ? 0.0 :
598: (double) stream->total_in / stream->total_out);
599: if (state->compression_in_failures == 0)
600: inflateEnd(stream);
601: }
1.14 markus 602: }
1.235 djm 603: cipher_free(state->send_context);
604: cipher_free(state->receive_context);
605: state->send_context = state->receive_context = NULL;
1.257 markus 606: if (do_close) {
607: free(ssh->remote_ipaddr);
608: ssh->remote_ipaddr = NULL;
609: free(ssh->state);
610: ssh->state = NULL;
611: }
612: }
613:
614: void
615: ssh_packet_close(struct ssh *ssh)
616: {
617: ssh_packet_close_internal(ssh, 1);
618: }
619:
620: void
621: ssh_packet_clear_keys(struct ssh *ssh)
622: {
623: ssh_packet_close_internal(ssh, 0);
1.1 deraadt 624: }
625:
626: /* Sets remote side protocol flags. */
627:
1.2 provos 628: void
1.201 markus 629: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 630: {
1.201 markus 631: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 632: }
633:
634: /* Returns the remote protocol flags set earlier by the above function. */
635:
1.40 markus 636: u_int
1.201 markus 637: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 638: {
1.201 markus 639: return ssh->state->remote_protocol_flags;
1.1 deraadt 640: }
641:
1.16 markus 642: /*
643: * Starts packet compression from the next packet on in both directions.
644: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
645: */
1.1 deraadt 646:
1.201 markus 647: static int
648: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 649: {
1.201 markus 650: if (!ssh->state->compression_buffer &&
651: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
652: return SSH_ERR_ALLOC_FAIL;
653: return 0;
1.60 markus 654: }
655:
1.201 markus 656: static int
657: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 658: {
1.201 markus 659: if (level < 1 || level > 9)
660: return SSH_ERR_INVALID_ARGUMENT;
661: debug("Enabling compression at level %d.", level);
662: if (ssh->state->compression_out_started == 1)
663: deflateEnd(&ssh->state->compression_out_stream);
664: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
665: case Z_OK:
666: ssh->state->compression_out_started = 1;
667: break;
668: case Z_MEM_ERROR:
669: return SSH_ERR_ALLOC_FAIL;
670: default:
671: return SSH_ERR_INTERNAL_ERROR;
672: }
673: return 0;
1.1 deraadt 674: }
675:
1.201 markus 676: static int
677: start_compression_in(struct ssh *ssh)
678: {
679: if (ssh->state->compression_in_started == 1)
680: inflateEnd(&ssh->state->compression_in_stream);
681: switch (inflateInit(&ssh->state->compression_in_stream)) {
682: case Z_OK:
683: ssh->state->compression_in_started = 1;
684: break;
685: case Z_MEM_ERROR:
686: return SSH_ERR_ALLOC_FAIL;
687: default:
688: return SSH_ERR_INTERNAL_ERROR;
689: }
690: return 0;
691: }
1.95 markus 692:
1.201 markus 693: int
694: ssh_packet_start_compression(struct ssh *ssh, int level)
1.1 deraadt 695: {
1.197 djm 696: int r;
1.97 deraadt 697:
1.249 djm 698: if (ssh->state->packet_compression)
1.201 markus 699: return SSH_ERR_INTERNAL_ERROR;
700: ssh->state->packet_compression = 1;
701: if ((r = ssh_packet_init_compression(ssh)) != 0 ||
702: (r = start_compression_in(ssh)) != 0 ||
703: (r = start_compression_out(ssh, level)) != 0)
704: return r;
705: return 0;
1.95 markus 706: }
707:
1.201 markus 708: /* XXX remove need for separate compression buffer */
709: static int
710: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 711: {
1.201 markus 712: u_char buf[4096];
713: int r, status;
714:
715: if (ssh->state->compression_out_started != 1)
716: return SSH_ERR_INTERNAL_ERROR;
717:
718: /* This case is not handled below. */
719: if (sshbuf_len(in) == 0)
720: return 0;
721:
722: /* Input is the contents of the input buffer. */
723: if ((ssh->state->compression_out_stream.next_in =
724: sshbuf_mutable_ptr(in)) == NULL)
725: return SSH_ERR_INTERNAL_ERROR;
726: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
727:
728: /* Loop compressing until deflate() returns with avail_out != 0. */
729: do {
730: /* Set up fixed-size output buffer. */
731: ssh->state->compression_out_stream.next_out = buf;
732: ssh->state->compression_out_stream.avail_out = sizeof(buf);
733:
734: /* Compress as much data into the buffer as possible. */
735: status = deflate(&ssh->state->compression_out_stream,
736: Z_PARTIAL_FLUSH);
737: switch (status) {
738: case Z_MEM_ERROR:
739: return SSH_ERR_ALLOC_FAIL;
740: case Z_OK:
741: /* Append compressed data to output_buffer. */
742: if ((r = sshbuf_put(out, buf, sizeof(buf) -
743: ssh->state->compression_out_stream.avail_out)) != 0)
744: return r;
745: break;
746: case Z_STREAM_ERROR:
747: default:
748: ssh->state->compression_out_failures++;
749: return SSH_ERR_INVALID_FORMAT;
750: }
751: } while (ssh->state->compression_out_stream.avail_out == 0);
752: return 0;
1.1 deraadt 753: }
754:
1.201 markus 755: static int
756: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 757: {
1.201 markus 758: u_char buf[4096];
759: int r, status;
1.1 deraadt 760:
1.201 markus 761: if (ssh->state->compression_in_started != 1)
762: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 763:
1.201 markus 764: if ((ssh->state->compression_in_stream.next_in =
765: sshbuf_mutable_ptr(in)) == NULL)
766: return SSH_ERR_INTERNAL_ERROR;
767: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 768:
1.201 markus 769: for (;;) {
770: /* Set up fixed-size output buffer. */
771: ssh->state->compression_in_stream.next_out = buf;
772: ssh->state->compression_in_stream.avail_out = sizeof(buf);
773:
774: status = inflate(&ssh->state->compression_in_stream,
775: Z_PARTIAL_FLUSH);
776: switch (status) {
777: case Z_OK:
778: if ((r = sshbuf_put(out, buf, sizeof(buf) -
779: ssh->state->compression_in_stream.avail_out)) != 0)
780: return r;
781: break;
782: case Z_BUF_ERROR:
783: /*
784: * Comments in zlib.h say that we should keep calling
785: * inflate() until we get an error. This appears to
786: * be the error that we get.
787: */
788: return 0;
789: case Z_DATA_ERROR:
790: return SSH_ERR_INVALID_FORMAT;
791: case Z_MEM_ERROR:
792: return SSH_ERR_ALLOC_FAIL;
793: case Z_STREAM_ERROR:
794: default:
795: ssh->state->compression_in_failures++;
796: return SSH_ERR_INTERNAL_ERROR;
797: }
798: }
799: /* NOTREACHED */
1.170 djm 800: }
801:
1.257 markus 802: void
803: ssh_clear_newkeys(struct ssh *ssh, int mode)
804: {
805: if (ssh->kex && ssh->kex->newkeys) {
806: kex_free_newkeys(ssh->kex->newkeys[mode]);
807: ssh->kex->newkeys[mode] = NULL;
808: }
809: }
810:
1.201 markus 811: int
812: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 813: {
1.201 markus 814: struct session_state *state = ssh->state;
815: struct sshenc *enc;
816: struct sshmac *mac;
817: struct sshcomp *comp;
1.235 djm 818: struct sshcipher_ctx **ccp;
1.236 markus 819: struct packet_state *ps;
1.105 markus 820: u_int64_t *max_blocks;
1.236 markus 821: const char *wmsg, *dir;
1.197 djm 822: int r, crypt_type;
1.57 markus 823:
1.100 markus 824: debug2("set_newkeys: mode %d", mode);
1.57 markus 825:
1.88 markus 826: if (mode == MODE_OUT) {
1.236 markus 827: dir = "output";
1.235 djm 828: ccp = &state->send_context;
1.115 avsm 829: crypt_type = CIPHER_ENCRYPT;
1.236 markus 830: ps = &state->p_send;
1.201 markus 831: max_blocks = &state->max_blocks_out;
1.88 markus 832: } else {
1.236 markus 833: dir = "input";
1.235 djm 834: ccp = &state->receive_context;
1.115 avsm 835: crypt_type = CIPHER_DECRYPT;
1.236 markus 836: ps = &state->p_read;
1.201 markus 837: max_blocks = &state->max_blocks_in;
1.88 markus 838: }
1.201 markus 839: if (state->newkeys[mode] != NULL) {
1.257 markus 840: debug("set_newkeys: rekeying, input %llu bytes %llu blocks, "
841: "output %llu bytes %llu blocks",
842: (unsigned long long)state->p_read.bytes,
843: (unsigned long long)state->p_read.blocks,
844: (unsigned long long)state->p_send.bytes,
845: (unsigned long long)state->p_send.blocks);
1.235 djm 846: cipher_free(*ccp);
847: *ccp = NULL;
1.257 markus 848: kex_free_newkeys(state->newkeys[mode]);
849: state->newkeys[mode] = NULL;
1.57 markus 850: }
1.236 markus 851: /* note that both bytes and the seqnr are not reset */
852: ps->packets = ps->blocks = 0;
1.201 markus 853: /* move newkeys from kex to state */
854: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
855: return SSH_ERR_INTERNAL_ERROR;
856: ssh->kex->newkeys[mode] = NULL;
857: enc = &state->newkeys[mode]->enc;
858: mac = &state->newkeys[mode]->mac;
859: comp = &state->newkeys[mode]->comp;
860: if (cipher_authlen(enc->cipher) == 0) {
861: if ((r = mac_init(mac)) != 0)
862: return r;
863: }
864: mac->enabled = 1;
1.57 markus 865: DBG(debug("cipher_init_context: %d", mode));
1.235 djm 866: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 867: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 868: return r;
869: if (!state->cipher_warning_done &&
1.235 djm 870: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 871: error("Warning: %s", wmsg);
872: state->cipher_warning_done = 1;
873: }
1.91 markus 874: /* Deleting the keys does not gain extra security */
1.192 djm 875: /* explicit_bzero(enc->iv, enc->block_size);
876: explicit_bzero(enc->key, enc->key_len);
877: explicit_bzero(mac->key, mac->key_len); */
1.241 djm 878: if ((comp->type == COMP_ZLIB ||
879: (comp->type == COMP_DELAYED &&
880: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 881: if ((r = ssh_packet_init_compression(ssh)) < 0)
882: return r;
883: if (mode == MODE_OUT) {
884: if ((r = start_compression_out(ssh, 6)) != 0)
885: return r;
886: } else {
887: if ((r = start_compression_in(ssh)) != 0)
888: return r;
889: }
1.57 markus 890: comp->enabled = 1;
891: }
1.109 markus 892: /*
893: * The 2^(blocksize*2) limit is too expensive for 3DES,
1.254 djm 894: * so enforce a 1GB limit for small blocksizes.
1.109 markus 895: */
896: if (enc->block_size >= 16)
897: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
898: else
899: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 900: if (state->rekey_limit)
1.237 deraadt 901: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 902: state->rekey_limit / enc->block_size);
1.227 djm 903: debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1.201 markus 904: return 0;
1.57 markus 905: }
906:
1.228 djm 907: #define MAX_PACKETS (1U<<31)
908: static int
909: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
910: {
911: struct session_state *state = ssh->state;
912: u_int32_t out_blocks;
913:
914: /* XXX client can't cope with rekeying pre-auth */
915: if (!state->after_authentication)
916: return 0;
917:
918: /* Haven't keyed yet or KEX in progress. */
919: if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
920: return 0;
921:
922: /* Peer can't rekey */
923: if (ssh->compat & SSH_BUG_NOREKEY)
924: return 0;
925:
926: /*
927: * Permit one packet in or out per rekey - this allows us to
928: * make progress when rekey limits are very small.
929: */
930: if (state->p_send.packets == 0 && state->p_read.packets == 0)
931: return 0;
932:
933: /* Time-based rekeying */
934: if (state->rekey_interval != 0 &&
1.244 dtucker 935: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 936: return 1;
937:
938: /* Always rekey when MAX_PACKETS sent in either direction */
939: if (state->p_send.packets > MAX_PACKETS ||
940: state->p_read.packets > MAX_PACKETS)
941: return 1;
942:
943: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 944: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 945: state->newkeys[MODE_OUT]->enc.block_size);
946: return (state->max_blocks_out &&
947: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
948: (state->max_blocks_in &&
949: (state->p_read.blocks > state->max_blocks_in));
950: }
951:
1.16 markus 952: /*
1.118 markus 953: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 954: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 955: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
956: */
1.201 markus 957: static int
958: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 959: {
1.201 markus 960: struct session_state *state = ssh->state;
961: struct sshcomp *comp = NULL;
962: int r, mode;
1.118 markus 963:
964: /*
965: * Remember that we are past the authentication step, so rekeying
966: * with COMP_DELAYED will turn on compression immediately.
967: */
1.201 markus 968: state->after_authentication = 1;
1.118 markus 969: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 970: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 971: if (state->newkeys[mode] == NULL)
1.145 markus 972: continue;
1.201 markus 973: comp = &state->newkeys[mode]->comp;
1.118 markus 974: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 975: if ((r = ssh_packet_init_compression(ssh)) != 0)
976: return r;
977: if (mode == MODE_OUT) {
978: if ((r = start_compression_out(ssh, 6)) != 0)
979: return r;
980: } else {
981: if ((r = start_compression_in(ssh)) != 0)
982: return r;
983: }
1.118 markus 984: comp->enabled = 1;
985: }
986: }
1.201 markus 987: return 0;
1.118 markus 988: }
989:
1.226 djm 990: /* Used to mute debug logging for noisy packet types */
1.242 markus 991: int
1.226 djm 992: ssh_packet_log_type(u_char type)
993: {
994: switch (type) {
995: case SSH2_MSG_CHANNEL_DATA:
996: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
997: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
998: return 0;
999: default:
1000: return 1;
1001: }
1002: }
1003:
1.118 markus 1004: /*
1.25 markus 1005: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1006: */
1.201 markus 1007: int
1008: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1009: {
1.201 markus 1010: struct session_state *state = ssh->state;
1.200 markus 1011: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1012: u_char tmp, padlen, pad = 0;
1.201 markus 1013: u_int authlen = 0, aadlen = 0;
1014: u_int len;
1015: struct sshenc *enc = NULL;
1016: struct sshmac *mac = NULL;
1017: struct sshcomp *comp = NULL;
1018: int r, block_size;
1019:
1020: if (state->newkeys[MODE_OUT] != NULL) {
1021: enc = &state->newkeys[MODE_OUT]->enc;
1022: mac = &state->newkeys[MODE_OUT]->mac;
1023: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1024: /* disable mac for authenticated encryption */
1025: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1026: mac = NULL;
1.25 markus 1027: }
1.88 markus 1028: block_size = enc ? enc->block_size : 8;
1.180 markus 1029: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1030:
1.201 markus 1031: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1032: if (ssh_packet_log_type(type))
1033: debug3("send packet: type %u", type);
1.25 markus 1034: #ifdef PACKET_DEBUG
1035: fprintf(stderr, "plain: ");
1.201 markus 1036: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1037: #endif
1038:
1039: if (comp && comp->enabled) {
1.201 markus 1040: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1041: /* skip header, compress only payload */
1.201 markus 1042: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1043: goto out;
1044: sshbuf_reset(state->compression_buffer);
1045: if ((r = compress_buffer(ssh, state->outgoing_packet,
1046: state->compression_buffer)) != 0)
1047: goto out;
1048: sshbuf_reset(state->outgoing_packet);
1049: if ((r = sshbuf_put(state->outgoing_packet,
1050: "\0\0\0\0\0", 5)) != 0 ||
1051: (r = sshbuf_putb(state->outgoing_packet,
1052: state->compression_buffer)) != 0)
1053: goto out;
1054: DBG(debug("compression: raw %d compressed %zd", len,
1055: sshbuf_len(state->outgoing_packet)));
1.25 markus 1056: }
1057:
1058: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1059: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1060:
1061: /*
1062: * calc size of padding, alloc space, get random data,
1063: * minimum padding is 4 bytes
1064: */
1.178 markus 1065: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1066: padlen = block_size - (len % block_size);
1067: if (padlen < 4)
1068: padlen += block_size;
1.201 markus 1069: if (state->extra_pad) {
1.233 djm 1070: tmp = state->extra_pad;
1.201 markus 1071: state->extra_pad =
1.237 deraadt 1072: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1073: /* check if roundup overflowed */
1074: if (state->extra_pad < tmp)
1075: return SSH_ERR_INVALID_ARGUMENT;
1076: tmp = (len + padlen) % state->extra_pad;
1077: /* Check whether pad calculation below will underflow */
1078: if (tmp > state->extra_pad)
1079: return SSH_ERR_INVALID_ARGUMENT;
1080: pad = state->extra_pad - tmp;
1.193 djm 1081: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1082: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1083: tmp = padlen;
1.71 markus 1084: padlen += pad;
1.233 djm 1085: /* Check whether padlen calculation overflowed */
1086: if (padlen < tmp)
1087: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1088: state->extra_pad = 0;
1.71 markus 1089: }
1.201 markus 1090: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1091: goto out;
1.235 djm 1092: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1093: /* random padding */
1.201 markus 1094: arc4random_buf(cp, padlen);
1.32 markus 1095: } else {
1096: /* clear padding */
1.192 djm 1097: explicit_bzero(cp, padlen);
1.25 markus 1098: }
1.178 markus 1099: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1100: len = sshbuf_len(state->outgoing_packet);
1101: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1102: if (cp == NULL) {
1103: r = SSH_ERR_INTERNAL_ERROR;
1104: goto out;
1105: }
1.25 markus 1106: /* packet_length includes payload, padding and padding length field */
1.201 markus 1107: POKE_U32(cp, len - 4);
1.89 markus 1108: cp[4] = padlen;
1.178 markus 1109: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1110: len, padlen, aadlen));
1.25 markus 1111:
1112: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1113: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1114: if ((r = mac_compute(mac, state->p_send.seqnr,
1115: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1116: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1117: goto out;
1118: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1119: }
1120: /* encrypt packet and append to output buffer. */
1.201 markus 1121: if ((r = sshbuf_reserve(state->output,
1122: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1123: goto out;
1.235 djm 1124: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1125: sshbuf_ptr(state->outgoing_packet),
1126: len - aadlen, aadlen, authlen)) != 0)
1127: goto out;
1.25 markus 1128: /* append unencrypted MAC */
1.178 markus 1129: if (mac && mac->enabled) {
1130: if (mac->etm) {
1131: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1132: if ((r = mac_compute(mac, state->p_send.seqnr,
1133: cp, len, macbuf, sizeof(macbuf))) != 0)
1134: goto out;
1.178 markus 1135: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1136: state->p_send.seqnr));
1.178 markus 1137: }
1.201 markus 1138: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1139: goto out;
1.178 markus 1140: }
1.25 markus 1141: #ifdef PACKET_DEBUG
1142: fprintf(stderr, "encrypted: ");
1.201 markus 1143: sshbuf_dump(state->output, stderr);
1.25 markus 1144: #endif
1.29 markus 1145: /* increment sequence number for outgoing packets */
1.201 markus 1146: if (++state->p_send.seqnr == 0)
1.106 itojun 1147: logit("outgoing seqnr wraps around");
1.201 markus 1148: if (++state->p_send.packets == 0)
1149: if (!(ssh->compat & SSH_BUG_NOREKEY))
1150: return SSH_ERR_NEED_REKEY;
1151: state->p_send.blocks += len / block_size;
1152: state->p_send.bytes += len;
1153: sshbuf_reset(state->outgoing_packet);
1.25 markus 1154:
1.57 markus 1155: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1156: r = ssh_set_newkeys(ssh, MODE_OUT);
1157: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1158: r = ssh_packet_enable_delayed_compress(ssh);
1159: else
1160: r = 0;
1161: out:
1162: return r;
1.25 markus 1163: }
1164:
1.228 djm 1165: /* returns non-zero if the specified packet type is usec by KEX */
1166: static int
1167: ssh_packet_type_is_kex(u_char type)
1168: {
1169: return
1170: type >= SSH2_MSG_TRANSPORT_MIN &&
1171: type <= SSH2_MSG_TRANSPORT_MAX &&
1172: type != SSH2_MSG_SERVICE_REQUEST &&
1173: type != SSH2_MSG_SERVICE_ACCEPT &&
1174: type != SSH2_MSG_EXT_INFO;
1175: }
1176:
1.201 markus 1177: int
1178: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1179: {
1.201 markus 1180: struct session_state *state = ssh->state;
1.105 markus 1181: struct packet *p;
1.201 markus 1182: u_char type;
1.228 djm 1183: int r, need_rekey;
1.105 markus 1184:
1.228 djm 1185: if (sshbuf_len(state->outgoing_packet) < 6)
1186: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1187: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1188: need_rekey = !ssh_packet_type_is_kex(type) &&
1189: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1190:
1.228 djm 1191: /*
1192: * During rekeying we can only send key exchange messages.
1193: * Queue everything else.
1194: */
1195: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1196: if (need_rekey)
1197: debug3("%s: rekex triggered", __func__);
1198: debug("enqueue packet: %u", type);
1199: p = calloc(1, sizeof(*p));
1200: if (p == NULL)
1201: return SSH_ERR_ALLOC_FAIL;
1202: p->type = type;
1203: p->payload = state->outgoing_packet;
1204: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1205: state->outgoing_packet = sshbuf_new();
1206: if (state->outgoing_packet == NULL)
1207: return SSH_ERR_ALLOC_FAIL;
1208: if (need_rekey) {
1209: /*
1210: * This packet triggered a rekey, so send the
1211: * KEXINIT now.
1212: * NB. reenters this function via kex_start_rekex().
1213: */
1214: return kex_start_rekex(ssh);
1.105 markus 1215: }
1.228 djm 1216: return 0;
1.105 markus 1217: }
1218:
1219: /* rekeying starts with sending KEXINIT */
1220: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1221: state->rekeying = 1;
1.105 markus 1222:
1.201 markus 1223: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1224: return r;
1.105 markus 1225:
1226: /* after a NEWKEYS message we can send the complete queue */
1227: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1228: state->rekeying = 0;
1229: state->rekey_time = monotime();
1230: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1231: type = p->type;
1.228 djm 1232: /*
1233: * If this packet triggers a rekex, then skip the
1234: * remaining packets in the queue for now.
1235: * NB. re-enters this function via kex_start_rekex.
1236: */
1237: if (ssh_packet_need_rekeying(ssh,
1238: sshbuf_len(p->payload))) {
1239: debug3("%s: queued packet triggered rekex",
1240: __func__);
1241: return kex_start_rekex(ssh);
1242: }
1.105 markus 1243: debug("dequeue packet: %u", type);
1.201 markus 1244: sshbuf_free(state->outgoing_packet);
1245: state->outgoing_packet = p->payload;
1246: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1247: memset(p, 0, sizeof(*p));
1.186 djm 1248: free(p);
1.201 markus 1249: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1250: return r;
1.105 markus 1251: }
1252: }
1.201 markus 1253: return 0;
1.25 markus 1254: }
1255:
1256: /*
1.16 markus 1257: * Waits until a packet has been received, and returns its type. Note that
1258: * no other data is processed until this returns, so this function should not
1259: * be used during the interactive session.
1260: */
1.1 deraadt 1261:
1.2 provos 1262: int
1.201 markus 1263: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1264: {
1.201 markus 1265: struct session_state *state = ssh->state;
1.222 markus 1266: int len, r, ms_remain;
1.56 millert 1267: fd_set *setp;
1.14 markus 1268: char buf[8192];
1.155 deraadt 1269: struct timeval timeout, start, *timeoutp = NULL;
1270:
1.25 markus 1271: DBG(debug("packet_read()"));
1.14 markus 1272:
1.214 deraadt 1273: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1274: NFDBITS), sizeof(fd_mask));
1.201 markus 1275: if (setp == NULL)
1276: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1277:
1.205 djm 1278: /*
1279: * Since we are blocking, ensure that all written packets have
1280: * been sent.
1281: */
1.210 markus 1282: if ((r = ssh_packet_write_wait(ssh)) != 0)
1283: goto out;
1.14 markus 1284:
1285: /* Stay in the loop until we have received a complete packet. */
1286: for (;;) {
1287: /* Try to read a packet from the buffer. */
1.201 markus 1288: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1289: if (r != 0)
1290: break;
1.14 markus 1291: /* If we got a packet, return it. */
1.201 markus 1292: if (*typep != SSH_MSG_NONE)
1293: break;
1.16 markus 1294: /*
1295: * Otherwise, wait for some data to arrive, add it to the
1296: * buffer, and try again.
1297: */
1.201 markus 1298: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1299: NFDBITS) * sizeof(fd_mask));
1.201 markus 1300: FD_SET(state->connection_in, setp);
1.16 markus 1301:
1.201 markus 1302: if (state->packet_timeout_ms > 0) {
1303: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1304: timeoutp = &timeout;
1305: }
1.14 markus 1306: /* Wait for some data to arrive. */
1.154 dtucker 1307: for (;;) {
1.201 markus 1308: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1309: ms_to_timeval(&timeout, ms_remain);
1310: gettimeofday(&start, NULL);
1311: }
1.201 markus 1312: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1313: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1314: break;
1.161 andreas 1315: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1316: break;
1.201 markus 1317: if (state->packet_timeout_ms == -1)
1.154 dtucker 1318: continue;
1319: ms_subtract_diff(&start, &ms_remain);
1320: if (ms_remain <= 0) {
1.201 markus 1321: r = 0;
1.154 dtucker 1322: break;
1323: }
1324: }
1.246 djm 1325: if (r == 0) {
1326: r = SSH_ERR_CONN_TIMEOUT;
1327: goto out;
1328: }
1.14 markus 1329: /* Read data from the socket. */
1.222 markus 1330: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1331: if (len == 0) {
1332: r = SSH_ERR_CONN_CLOSED;
1333: goto out;
1334: }
1335: if (len < 0) {
1336: r = SSH_ERR_SYSTEM_ERROR;
1337: goto out;
1338: }
1.204 djm 1339:
1.14 markus 1340: /* Append it to the buffer. */
1.204 djm 1341: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1342: goto out;
1.14 markus 1343: }
1.210 markus 1344: out:
1.201 markus 1345: free(setp);
1346: return r;
1.1 deraadt 1347: }
1348:
1.77 djm 1349: int
1.201 markus 1350: ssh_packet_read(struct ssh *ssh)
1.77 djm 1351: {
1.201 markus 1352: u_char type;
1353: int r;
1354:
1355: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1356: fatal("%s: %s", __func__, ssh_err(r));
1357: return type;
1.77 djm 1358: }
1359:
1.16 markus 1360: /*
1361: * Waits until a packet has been received, verifies that its type matches
1362: * that given, and gives a fatal error and exits if there is a mismatch.
1363: */
1.1 deraadt 1364:
1.205 djm 1365: int
1366: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1367: {
1.205 djm 1368: int r;
1369: u_char type;
1.1 deraadt 1370:
1.205 djm 1371: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1372: return r;
1373: if (type != expected_type) {
1374: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1375: "Protocol error: expected packet type %d, got %d",
1.205 djm 1376: expected_type, type)) != 0)
1377: return r;
1378: return SSH_ERR_PROTOCOL_ERROR;
1379: }
1380: return 0;
1.1 deraadt 1381: }
1.14 markus 1382:
1.242 markus 1383: static int
1384: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1385: {
1386: struct session_state *state = ssh->state;
1387: const u_char *cp;
1388: size_t need;
1389: int r;
1390:
1391: if (ssh->kex)
1392: return SSH_ERR_INTERNAL_ERROR;
1393: *typep = SSH_MSG_NONE;
1394: cp = sshbuf_ptr(state->input);
1395: if (state->packlen == 0) {
1396: if (sshbuf_len(state->input) < 4 + 1)
1397: return 0; /* packet is incomplete */
1398: state->packlen = PEEK_U32(cp);
1399: if (state->packlen < 4 + 1 ||
1400: state->packlen > PACKET_MAX_SIZE)
1401: return SSH_ERR_MESSAGE_INCOMPLETE;
1402: }
1403: need = state->packlen + 4;
1404: if (sshbuf_len(state->input) < need)
1405: return 0; /* packet is incomplete */
1406: sshbuf_reset(state->incoming_packet);
1407: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1408: state->packlen)) != 0 ||
1409: (r = sshbuf_consume(state->input, need)) != 0 ||
1410: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1411: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1412: return r;
1413: if (ssh_packet_log_type(*typep))
1414: debug3("%s: type %u", __func__, *typep);
1415: /* sshbuf_dump(state->incoming_packet, stderr); */
1416: /* reset for next packet */
1417: state->packlen = 0;
1418: return r;
1419: }
1420:
1.201 markus 1421: int
1422: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1423: {
1.201 markus 1424: struct session_state *state = ssh->state;
1.40 markus 1425: u_int padlen, need;
1.231 djm 1426: u_char *cp;
1.201 markus 1427: u_int maclen, aadlen = 0, authlen = 0, block_size;
1428: struct sshenc *enc = NULL;
1429: struct sshmac *mac = NULL;
1430: struct sshcomp *comp = NULL;
1.200 markus 1431: int r;
1.201 markus 1432:
1.242 markus 1433: if (state->mux)
1434: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1435:
1.201 markus 1436: *typep = SSH_MSG_NONE;
1437:
1438: if (state->packet_discard)
1439: return 0;
1440:
1441: if (state->newkeys[MODE_IN] != NULL) {
1442: enc = &state->newkeys[MODE_IN]->enc;
1443: mac = &state->newkeys[MODE_IN]->mac;
1444: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1445: /* disable mac for authenticated encryption */
1446: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1447: mac = NULL;
1.25 markus 1448: }
1449: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1450: block_size = enc ? enc->block_size : 8;
1.180 markus 1451: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1452:
1.201 markus 1453: if (aadlen && state->packlen == 0) {
1.235 djm 1454: if (cipher_get_length(state->receive_context,
1.201 markus 1455: &state->packlen, state->p_read.seqnr,
1456: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1457: return 0;
1458: if (state->packlen < 1 + 4 ||
1459: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1460: #ifdef PACKET_DEBUG
1.201 markus 1461: sshbuf_dump(state->input, stderr);
1.178 markus 1462: #endif
1.201 markus 1463: logit("Bad packet length %u.", state->packlen);
1464: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1465: return r;
1.217 djm 1466: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1467: }
1.201 markus 1468: sshbuf_reset(state->incoming_packet);
1469: } else if (state->packlen == 0) {
1.25 markus 1470: /*
1471: * check if input size is less than the cipher block size,
1472: * decrypt first block and extract length of incoming packet
1473: */
1.201 markus 1474: if (sshbuf_len(state->input) < block_size)
1475: return 0;
1476: sshbuf_reset(state->incoming_packet);
1477: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1478: &cp)) != 0)
1479: goto out;
1.235 djm 1480: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1481: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1482: block_size, 0, 0)) != 0)
1483: goto out;
1484: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1485: if (state->packlen < 1 + 4 ||
1486: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1487: #ifdef PACKET_DEBUG
1.201 markus 1488: fprintf(stderr, "input: \n");
1489: sshbuf_dump(state->input, stderr);
1490: fprintf(stderr, "incoming_packet: \n");
1491: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1492: #endif
1.201 markus 1493: logit("Bad packet length %u.", state->packlen);
1.234 markus 1494: return ssh_packet_start_discard(ssh, enc, mac, 0,
1495: PACKET_MAX_SIZE);
1.25 markus 1496: }
1.201 markus 1497: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1498: goto out;
1.25 markus 1499: }
1.201 markus 1500: DBG(debug("input: packet len %u", state->packlen+4));
1501:
1.178 markus 1502: if (aadlen) {
1503: /* only the payload is encrypted */
1.201 markus 1504: need = state->packlen;
1.178 markus 1505: } else {
1506: /*
1507: * the payload size and the payload are encrypted, but we
1508: * have a partial packet of block_size bytes
1509: */
1.201 markus 1510: need = 4 + state->packlen - block_size;
1.178 markus 1511: }
1.180 markus 1512: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1513: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1514: if (need % block_size != 0) {
1515: logit("padding error: need %d block %d mod %d",
1.25 markus 1516: need, block_size, need % block_size);
1.234 markus 1517: return ssh_packet_start_discard(ssh, enc, mac, 0,
1518: PACKET_MAX_SIZE - block_size);
1.158 markus 1519: }
1.25 markus 1520: /*
1521: * check if the entire packet has been received and
1.178 markus 1522: * decrypt into incoming_packet:
1523: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1524: * 'need' bytes are encrypted, followed by either
1525: * 'authlen' bytes of authentication tag or
1.178 markus 1526: * 'maclen' bytes of message authentication code.
1.25 markus 1527: */
1.201 markus 1528: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1529: return 0; /* packet is incomplete */
1.25 markus 1530: #ifdef PACKET_DEBUG
1531: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1532: sshbuf_dump(state->input, stderr);
1.25 markus 1533: #endif
1.231 djm 1534: /* EtM: check mac over encrypted input */
1.201 markus 1535: if (mac && mac->enabled && mac->etm) {
1.231 djm 1536: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1537: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1538: sshbuf_ptr(state->input) + aadlen + need + authlen,
1539: maclen)) != 0) {
1540: if (r == SSH_ERR_MAC_INVALID)
1541: logit("Corrupted MAC on input.");
1.201 markus 1542: goto out;
1.231 djm 1543: }
1.201 markus 1544: }
1545: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1546: &cp)) != 0)
1547: goto out;
1.235 djm 1548: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1549: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1550: goto out;
1551: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1552: goto out;
1.29 markus 1553: if (mac && mac->enabled) {
1.231 djm 1554: /* Not EtM: check MAC over cleartext */
1555: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1556: sshbuf_ptr(state->incoming_packet),
1557: sshbuf_len(state->incoming_packet),
1558: sshbuf_ptr(state->input), maclen)) != 0) {
1559: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1560: goto out;
1.159 markus 1561: logit("Corrupted MAC on input.");
1.247 markus 1562: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1563: return SSH_ERR_INTERNAL_ERROR;
1564: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1565: sshbuf_len(state->incoming_packet),
1.247 markus 1566: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1567: }
1.231 djm 1568: /* Remove MAC from input buffer */
1.201 markus 1569: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1570: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1571: goto out;
1.25 markus 1572: }
1.77 djm 1573: if (seqnr_p != NULL)
1.201 markus 1574: *seqnr_p = state->p_read.seqnr;
1575: if (++state->p_read.seqnr == 0)
1.106 itojun 1576: logit("incoming seqnr wraps around");
1.201 markus 1577: if (++state->p_read.packets == 0)
1578: if (!(ssh->compat & SSH_BUG_NOREKEY))
1579: return SSH_ERR_NEED_REKEY;
1580: state->p_read.blocks += (state->packlen + 4) / block_size;
1581: state->p_read.bytes += state->packlen + 4;
1.25 markus 1582:
1583: /* get padlen */
1.201 markus 1584: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1585: DBG(debug("input: padlen %d", padlen));
1.205 djm 1586: if (padlen < 4) {
1587: if ((r = sshpkt_disconnect(ssh,
1588: "Corrupted padlen %d on input.", padlen)) != 0 ||
1589: (r = ssh_packet_write_wait(ssh)) != 0)
1590: return r;
1591: return SSH_ERR_CONN_CORRUPT;
1592: }
1.25 markus 1593:
1594: /* skip packet size + padlen, discard padding */
1.201 markus 1595: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1596: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1597: goto out;
1.25 markus 1598:
1.201 markus 1599: DBG(debug("input: len before de-compress %zd",
1600: sshbuf_len(state->incoming_packet)));
1.25 markus 1601: if (comp && comp->enabled) {
1.201 markus 1602: sshbuf_reset(state->compression_buffer);
1603: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1604: state->compression_buffer)) != 0)
1605: goto out;
1606: sshbuf_reset(state->incoming_packet);
1607: if ((r = sshbuf_putb(state->incoming_packet,
1608: state->compression_buffer)) != 0)
1609: goto out;
1610: DBG(debug("input: len after de-compress %zd",
1611: sshbuf_len(state->incoming_packet)));
1.25 markus 1612: }
1613: /*
1614: * get packet type, implies consume.
1615: * return length of payload (without type field)
1616: */
1.201 markus 1617: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1618: goto out;
1.226 djm 1619: if (ssh_packet_log_type(*typep))
1620: debug3("receive packet: type %u", *typep);
1.205 djm 1621: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1622: if ((r = sshpkt_disconnect(ssh,
1623: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1624: (r = ssh_packet_write_wait(ssh)) != 0)
1625: return r;
1626: return SSH_ERR_PROTOCOL_ERROR;
1627: }
1.243 djm 1628: if (state->hook_in != NULL &&
1629: (r = state->hook_in(ssh, state->incoming_packet, typep,
1630: state->hook_in_ctx)) != 0)
1631: return r;
1.238 markus 1632: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1633: r = ssh_packet_enable_delayed_compress(ssh);
1634: else
1635: r = 0;
1.25 markus 1636: #ifdef PACKET_DEBUG
1.201 markus 1637: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1638: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1639: #endif
1.62 markus 1640: /* reset for next packet */
1.201 markus 1641: state->packlen = 0;
1.228 djm 1642:
1643: /* do we need to rekey? */
1644: if (ssh_packet_need_rekeying(ssh, 0)) {
1645: debug3("%s: rekex triggered", __func__);
1646: if ((r = kex_start_rekex(ssh)) != 0)
1647: return r;
1648: }
1.201 markus 1649: out:
1650: return r;
1.25 markus 1651: }
1652:
1653: int
1.201 markus 1654: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1655: {
1.201 markus 1656: struct session_state *state = ssh->state;
1.96 deraadt 1657: u_int reason, seqnr;
1.201 markus 1658: int r;
1659: u_char *msg;
1.62 markus 1660:
1.25 markus 1661: for (;;) {
1.201 markus 1662: msg = NULL;
1.249 djm 1663: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1664: if (r != 0)
1665: return r;
1666: if (*typep) {
1667: state->keep_alive_timeouts = 0;
1668: DBG(debug("received packet type %d", *typep));
1669: }
1670: switch (*typep) {
1671: case SSH2_MSG_IGNORE:
1672: debug3("Received SSH2_MSG_IGNORE");
1673: break;
1674: case SSH2_MSG_DEBUG:
1675: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1676: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1677: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1678: free(msg);
1.201 markus 1679: return r;
1.48 stevesk 1680: }
1.249 djm 1681: debug("Remote: %.900s", msg);
1682: free(msg);
1683: break;
1684: case SSH2_MSG_DISCONNECT:
1685: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1686: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1687: return r;
1688: /* Ignore normal client exit notifications */
1689: do_log2(ssh->state->server_side &&
1690: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1691: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1692: "Received disconnect from %s port %d:"
1693: "%u: %.400s", ssh_remote_ipaddr(ssh),
1694: ssh_remote_port(ssh), reason, msg);
1695: free(msg);
1696: return SSH_ERR_DISCONNECTED;
1697: case SSH2_MSG_UNIMPLEMENTED:
1698: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1699: return r;
1700: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1701: seqnr);
1702: break;
1703: default:
1704: return 0;
1.25 markus 1705: }
1706: }
1707: }
1708:
1.16 markus 1709: /*
1710: * Buffers the given amount of input characters. This is intended to be used
1711: * together with packet_read_poll.
1712: */
1.1 deraadt 1713:
1.204 djm 1714: int
1.201 markus 1715: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1716: {
1.201 markus 1717: struct session_state *state = ssh->state;
1718: int r;
1719:
1720: if (state->packet_discard) {
1721: state->keep_alive_timeouts = 0; /* ?? */
1722: if (len >= state->packet_discard) {
1723: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1724: return r;
1.201 markus 1725: }
1726: state->packet_discard -= len;
1.204 djm 1727: return 0;
1.159 markus 1728: }
1.201 markus 1729: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1730: return r;
1731:
1732: return 0;
1.28 markus 1733: }
1734:
1735: int
1.201 markus 1736: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1737: {
1.201 markus 1738: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1739: }
1740:
1.16 markus 1741: /*
1742: * Sends a diagnostic message from the server to the client. This message
1743: * can be sent at any time (but not while constructing another message). The
1744: * message is printed immediately, but only if the client is being executed
1745: * in verbose mode. These messages are primarily intended to ease debugging
1746: * authentication problems. The length of the formatted message must not
1.205 djm 1747: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1748: */
1.2 provos 1749: void
1.201 markus 1750: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1751: {
1.14 markus 1752: char buf[1024];
1753: va_list args;
1.201 markus 1754: int r;
1.39 markus 1755:
1.249 djm 1756: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1757: return;
1.14 markus 1758:
1759: va_start(args, fmt);
1760: vsnprintf(buf, sizeof(buf), fmt, args);
1761: va_end(args);
1762:
1.249 djm 1763: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1764: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1765: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1766: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1767: (r = sshpkt_send(ssh)) != 0 ||
1768: (r = ssh_packet_write_wait(ssh)) != 0)
1.205 djm 1769: fatal("%s: %s", __func__, ssh_err(r));
1770: }
1771:
1.245 djm 1772: static void
1773: fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1774: {
1775: snprintf(s, l, "%.200s%s%s port %d",
1776: ssh->log_preamble ? ssh->log_preamble : "",
1777: ssh->log_preamble ? " " : "",
1778: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1779: }
1780:
1.205 djm 1781: /*
1782: * Pretty-print connection-terminating errors and exit.
1783: */
1784: void
1785: sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
1786: {
1.245 djm 1787: char remote_id[512];
1788:
1789: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1790:
1.205 djm 1791: switch (r) {
1792: case SSH_ERR_CONN_CLOSED:
1.257 markus 1793: ssh_packet_clear_keys(ssh);
1.245 djm 1794: logdie("Connection closed by %s", remote_id);
1.205 djm 1795: case SSH_ERR_CONN_TIMEOUT:
1.257 markus 1796: ssh_packet_clear_keys(ssh);
1.245 djm 1797: logdie("Connection %s %s timed out",
1798: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1799: case SSH_ERR_DISCONNECTED:
1.257 markus 1800: ssh_packet_clear_keys(ssh);
1.245 djm 1801: logdie("Disconnected from %s", remote_id);
1.212 djm 1802: case SSH_ERR_SYSTEM_ERROR:
1.257 markus 1803: if (errno == ECONNRESET) {
1804: ssh_packet_clear_keys(ssh);
1.245 djm 1805: logdie("Connection reset by %s", remote_id);
1.257 markus 1806: }
1.213 djm 1807: /* FALLTHROUGH */
1808: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1809: case SSH_ERR_NO_MAC_ALG_MATCH:
1810: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1811: case SSH_ERR_NO_KEX_ALG_MATCH:
1812: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1813: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.257 markus 1814: ssh_packet_clear_keys(ssh);
1.245 djm 1815: logdie("Unable to negotiate with %s: %s. "
1816: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1817: ssh->kex->failed_choice);
1.212 djm 1818: }
1819: /* FALLTHROUGH */
1.205 djm 1820: default:
1.257 markus 1821: ssh_packet_clear_keys(ssh);
1.245 djm 1822: logdie("%s%sConnection %s %s: %s",
1.205 djm 1823: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 1824: ssh->state->server_side ? "from" : "to",
1.245 djm 1825: remote_id, ssh_err(r));
1.205 djm 1826: }
1.1 deraadt 1827: }
1828:
1.16 markus 1829: /*
1830: * Logs the error plus constructs and sends a disconnect packet, closes the
1831: * connection, and exits. This function never returns. The error message
1832: * should not contain a newline. The length of the formatted message must
1833: * not exceed 1024 bytes.
1834: */
1.2 provos 1835: void
1.201 markus 1836: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1837: {
1.245 djm 1838: char buf[1024], remote_id[512];
1.14 markus 1839: va_list args;
1840: static int disconnecting = 0;
1.201 markus 1841: int r;
1.97 deraadt 1842:
1.14 markus 1843: if (disconnecting) /* Guard against recursive invocations. */
1844: fatal("packet_disconnect called recursively.");
1845: disconnecting = 1;
1846:
1.16 markus 1847: /*
1848: * Format the message. Note that the caller must make sure the
1849: * message is of limited size.
1850: */
1.245 djm 1851: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1852: va_start(args, fmt);
1853: vsnprintf(buf, sizeof(buf), fmt, args);
1854: va_end(args);
1855:
1.99 markus 1856: /* Display the error locally */
1.245 djm 1857: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1858:
1.205 djm 1859: /*
1860: * Send the disconnect message to the other side, and wait
1861: * for it to get sent.
1862: */
1863: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1864: sshpkt_fatal(ssh, __func__, r);
1865:
1866: if ((r = ssh_packet_write_wait(ssh)) != 0)
1867: sshpkt_fatal(ssh, __func__, r);
1.14 markus 1868:
1869: /* Close the connection. */
1.201 markus 1870: ssh_packet_close(ssh);
1.112 markus 1871: cleanup_exit(255);
1.1 deraadt 1872: }
1873:
1.205 djm 1874: /*
1875: * Checks if there is any buffered output, and tries to write some of
1876: * the output.
1877: */
1878: int
1.201 markus 1879: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1880: {
1.201 markus 1881: struct session_state *state = ssh->state;
1882: int len = sshbuf_len(state->output);
1.222 markus 1883: int r;
1.97 deraadt 1884:
1.14 markus 1885: if (len > 0) {
1.222 markus 1886: len = write(state->connection_out,
1887: sshbuf_ptr(state->output), len);
1.156 djm 1888: if (len == -1) {
1889: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1890: return 0;
1891: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1892: }
1.222 markus 1893: if (len == 0)
1.205 djm 1894: return SSH_ERR_CONN_CLOSED;
1.201 markus 1895: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1896: return r;
1.14 markus 1897: }
1.205 djm 1898: return 0;
1.1 deraadt 1899: }
1900:
1.16 markus 1901: /*
1902: * Calls packet_write_poll repeatedly until all pending output data has been
1903: * written.
1904: */
1.205 djm 1905: int
1.201 markus 1906: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1907: {
1.56 millert 1908: fd_set *setp;
1.205 djm 1909: int ret, r, ms_remain = 0;
1.154 dtucker 1910: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1911: struct session_state *state = ssh->state;
1.56 millert 1912:
1.214 deraadt 1913: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1914: NFDBITS), sizeof(fd_mask));
1.201 markus 1915: if (setp == NULL)
1.205 djm 1916: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1917: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1918: free(setp);
1.215 djm 1919: return r;
1.216 gsoares 1920: }
1.201 markus 1921: while (ssh_packet_have_data_to_write(ssh)) {
1922: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1923: NFDBITS) * sizeof(fd_mask));
1.201 markus 1924: FD_SET(state->connection_out, setp);
1.154 dtucker 1925:
1.201 markus 1926: if (state->packet_timeout_ms > 0) {
1927: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1928: timeoutp = &timeout;
1929: }
1930: for (;;) {
1.201 markus 1931: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1932: ms_to_timeval(&timeout, ms_remain);
1933: gettimeofday(&start, NULL);
1934: }
1.201 markus 1935: if ((ret = select(state->connection_out + 1,
1.161 andreas 1936: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1937: break;
1.161 andreas 1938: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1939: break;
1.201 markus 1940: if (state->packet_timeout_ms == -1)
1.154 dtucker 1941: continue;
1942: ms_subtract_diff(&start, &ms_remain);
1943: if (ms_remain <= 0) {
1944: ret = 0;
1945: break;
1946: }
1947: }
1948: if (ret == 0) {
1.205 djm 1949: free(setp);
1950: return SSH_ERR_CONN_TIMEOUT;
1951: }
1952: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1953: free(setp);
1954: return r;
1.154 dtucker 1955: }
1.14 markus 1956: }
1.186 djm 1957: free(setp);
1.205 djm 1958: return 0;
1.1 deraadt 1959: }
1960:
1961: /* Returns true if there is buffered data to write to the connection. */
1962:
1.2 provos 1963: int
1.201 markus 1964: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 1965: {
1.201 markus 1966: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 1967: }
1968:
1969: /* Returns true if there is not too much data to write to the connection. */
1970:
1.2 provos 1971: int
1.201 markus 1972: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 1973: {
1.201 markus 1974: if (ssh->state->interactive_mode)
1975: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 1976: else
1.201 markus 1977: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 1978: }
1979:
1.201 markus 1980: void
1981: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 1982: {
1.201 markus 1983: if (!ssh_packet_connection_is_on_socket(ssh))
1.101 markus 1984: return;
1.201 markus 1985: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 1986: case AF_INET:
1987: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 1988: if (setsockopt(ssh->state->connection_in,
1.173 djm 1989: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
1990: error("setsockopt IP_TOS %d: %.100s:",
1991: tos, strerror(errno));
1992: break;
1993: case AF_INET6:
1994: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 1995: if (setsockopt(ssh->state->connection_in,
1.173 djm 1996: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
1997: error("setsockopt IPV6_TCLASS %d: %.100s:",
1998: tos, strerror(errno));
1999: break;
2000: }
1.101 markus 2001: }
2002:
1.1 deraadt 2003: /* Informs that the current session is interactive. Sets IP flags for that. */
2004:
1.2 provos 2005: void
1.201 markus 2006: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2007: {
1.201 markus 2008: struct session_state *state = ssh->state;
2009:
2010: if (state->set_interactive_called)
1.43 markus 2011: return;
1.201 markus 2012: state->set_interactive_called = 1;
1.1 deraadt 2013:
1.14 markus 2014: /* Record that we are in interactive mode. */
1.201 markus 2015: state->interactive_mode = interactive;
1.1 deraadt 2016:
1.19 markus 2017: /* Only set socket options if using a socket. */
1.201 markus 2018: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2019: return;
1.201 markus 2020: set_nodelay(state->connection_in);
2021: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2022: qos_bulk);
1.1 deraadt 2023: }
2024:
2025: /* Returns true if the current connection is interactive. */
2026:
1.2 provos 2027: int
1.201 markus 2028: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2029: {
1.201 markus 2030: return ssh->state->interactive_mode;
1.12 markus 2031: }
2032:
1.113 deraadt 2033: int
1.201 markus 2034: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2035: {
1.201 markus 2036: struct session_state *state = ssh->state;
2037:
2038: if (state->set_maxsize_called) {
1.106 itojun 2039: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2040: state->max_packet_size, s);
1.14 markus 2041: return -1;
2042: }
2043: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2044: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2045: return -1;
2046: }
1.201 markus 2047: state->set_maxsize_called = 1;
1.66 markus 2048: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2049: state->max_packet_size = s;
1.14 markus 2050: return s;
1.53 markus 2051: }
2052:
1.161 andreas 2053: int
1.201 markus 2054: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2055: {
1.201 markus 2056: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2057: }
2058:
2059: void
1.201 markus 2060: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2061: {
1.201 markus 2062: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2063: }
2064:
2065: u_int
1.201 markus 2066: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2067: {
1.201 markus 2068: return ssh->state->max_packet_size;
1.71 markus 2069: }
2070:
1.53 markus 2071: /*
2072: * 9.2. Ignored Data Message
1.61 markus 2073: *
1.53 markus 2074: * byte SSH_MSG_IGNORE
2075: * string data
1.61 markus 2076: *
1.53 markus 2077: * All implementations MUST understand (and ignore) this message at any
2078: * time (after receiving the protocol version). No implementation is
2079: * required to send them. This message can be used as an additional
2080: * protection measure against advanced traffic analysis techniques.
2081: */
1.54 markus 2082: void
1.201 markus 2083: ssh_packet_send_ignore(struct ssh *ssh, int nbytes)
1.54 markus 2084: {
1.115 avsm 2085: u_int32_t rnd = 0;
1.201 markus 2086: int r, i;
1.54 markus 2087:
1.249 djm 2088: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
1.201 markus 2089: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2090: fatal("%s: %s", __func__, ssh_err(r));
1.75 deraadt 2091: for (i = 0; i < nbytes; i++) {
1.53 markus 2092: if (i % 4 == 0)
1.115 avsm 2093: rnd = arc4random();
1.201 markus 2094: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2095: fatal("%s: %s", __func__, ssh_err(r));
1.115 avsm 2096: rnd >>= 8;
1.53 markus 2097: }
1.105 markus 2098: }
2099:
2100: void
1.244 dtucker 2101: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2102: {
1.244 dtucker 2103: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2104: (unsigned int)seconds);
1.201 markus 2105: ssh->state->rekey_limit = bytes;
2106: ssh->state->rekey_interval = seconds;
1.184 dtucker 2107: }
2108:
2109: time_t
1.201 markus 2110: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2111: {
2112: time_t seconds;
2113:
1.201 markus 2114: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2115: monotime();
1.185 dtucker 2116: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2117: }
2118:
2119: void
1.201 markus 2120: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2121: {
1.201 markus 2122: ssh->state->server_side = 1;
1.118 markus 2123: }
2124:
2125: void
1.201 markus 2126: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2127: {
1.201 markus 2128: ssh->state->after_authentication = 1;
1.161 andreas 2129: }
2130:
2131: void *
1.201 markus 2132: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2133: {
1.201 markus 2134: return (void *)ssh->state->input;
1.161 andreas 2135: }
2136:
2137: void *
1.201 markus 2138: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2139: {
1.201 markus 2140: return (void *)ssh->state->output;
1.166 andreas 2141: }
2142:
1.196 markus 2143: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2144: static int
2145: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2146: {
1.239 djm 2147: int r;
1.196 markus 2148:
2149: debug("%s: called", __func__);
2150: /* This was set in net child, but is not visible in user child */
1.201 markus 2151: ssh->state->after_authentication = 1;
2152: ssh->state->rekeying = 0;
1.239 djm 2153: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2154: return r;
1.201 markus 2155: return 0;
2156: }
2157:
2158: /* Packet state (de-)serialization for privsep */
2159:
2160: /* turn kex into a blob for packet state serialization */
2161: static int
2162: kex_to_blob(struct sshbuf *m, struct kex *kex)
2163: {
2164: int r;
2165:
2166: if ((r = sshbuf_put_string(m, kex->session_id,
2167: kex->session_id_len)) != 0 ||
2168: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2169: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2170: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2171: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2172: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2173: (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2174: (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2175: (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2176: return r;
2177: return 0;
2178: }
2179:
2180: /* turn key exchange results into a blob for packet state serialization */
2181: static int
2182: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2183: {
2184: struct sshbuf *b;
2185: struct sshcipher_ctx *cc;
2186: struct sshcomp *comp;
2187: struct sshenc *enc;
2188: struct sshmac *mac;
2189: struct newkeys *newkey;
2190: int r;
2191:
2192: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2193: return SSH_ERR_INTERNAL_ERROR;
2194: enc = &newkey->enc;
2195: mac = &newkey->mac;
2196: comp = &newkey->comp;
1.235 djm 2197: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2198: ssh->state->receive_context;
1.201 markus 2199: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2200: return r;
2201: if ((b = sshbuf_new()) == NULL)
2202: return SSH_ERR_ALLOC_FAIL;
2203: /* The cipher struct is constant and shared, you export pointer */
2204: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2205: (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2206: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2207: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2208: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2209: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2210: goto out;
2211: if (cipher_authlen(enc->cipher) == 0) {
2212: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2213: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2214: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2215: goto out;
2216: }
2217: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2218: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2219: goto out;
2220: r = sshbuf_put_stringb(m, b);
2221: out:
1.221 mmcc 2222: sshbuf_free(b);
1.201 markus 2223: return r;
2224: }
2225:
2226: /* serialize packet state into a blob */
2227: int
2228: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2229: {
2230: struct session_state *state = ssh->state;
1.249 djm 2231: int r;
1.201 markus 2232:
1.249 djm 2233: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2234: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2235: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2236: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2237: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2238: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2239: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2240: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2241: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2242: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2243: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2244: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2245: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2246: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2247: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 2248: return r;
1.201 markus 2249:
2250: return 0;
2251: }
2252:
2253: /* restore key exchange results from blob for packet state de-serialization */
2254: static int
2255: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2256: {
2257: struct sshbuf *b = NULL;
2258: struct sshcomp *comp;
2259: struct sshenc *enc;
2260: struct sshmac *mac;
2261: struct newkeys *newkey = NULL;
2262: size_t keylen, ivlen, maclen;
2263: int r;
2264:
2265: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2266: r = SSH_ERR_ALLOC_FAIL;
2267: goto out;
2268: }
2269: if ((r = sshbuf_froms(m, &b)) != 0)
2270: goto out;
2271: #ifdef DEBUG_PK
2272: sshbuf_dump(b, stderr);
2273: #endif
2274: enc = &newkey->enc;
2275: mac = &newkey->mac;
2276: comp = &newkey->comp;
2277:
2278: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2279: (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2280: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2281: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2282: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2283: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2284: goto out;
2285: if (cipher_authlen(enc->cipher) == 0) {
2286: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2287: goto out;
2288: if ((r = mac_setup(mac, mac->name)) != 0)
2289: goto out;
2290: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2291: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2292: goto out;
2293: if (maclen > mac->key_len) {
2294: r = SSH_ERR_INVALID_FORMAT;
2295: goto out;
2296: }
2297: mac->key_len = maclen;
2298: }
2299: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2300: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2301: goto out;
2302: if (enc->name == NULL ||
2303: cipher_by_name(enc->name) != enc->cipher) {
2304: r = SSH_ERR_INVALID_FORMAT;
2305: goto out;
2306: }
2307: if (sshbuf_len(b) != 0) {
2308: r = SSH_ERR_INVALID_FORMAT;
2309: goto out;
2310: }
2311: enc->key_len = keylen;
2312: enc->iv_len = ivlen;
2313: ssh->kex->newkeys[mode] = newkey;
2314: newkey = NULL;
2315: r = 0;
2316: out:
1.219 mmcc 2317: free(newkey);
1.221 mmcc 2318: sshbuf_free(b);
1.201 markus 2319: return r;
2320: }
2321:
2322: /* restore kex from blob for packet state de-serialization */
2323: static int
2324: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2325: {
2326: struct kex *kex;
2327: int r;
2328:
2329: if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2330: (kex->my = sshbuf_new()) == NULL ||
2331: (kex->peer = sshbuf_new()) == NULL) {
2332: r = SSH_ERR_ALLOC_FAIL;
2333: goto out;
2334: }
2335: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2336: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2337: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2338: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2339: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2340: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2341: (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2342: (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2343: (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2344: goto out;
2345: kex->server = 1;
2346: kex->done = 1;
2347: r = 0;
2348: out:
2349: if (r != 0 || kexp == NULL) {
2350: if (kex != NULL) {
1.221 mmcc 2351: sshbuf_free(kex->my);
2352: sshbuf_free(kex->peer);
1.201 markus 2353: free(kex);
2354: }
2355: if (kexp != NULL)
2356: *kexp = NULL;
2357: } else {
2358: *kexp = kex;
2359: }
2360: return r;
2361: }
2362:
2363: /*
2364: * Restore packet state from content of blob 'm' (de-serialization).
2365: * Note that 'm' will be partially consumed on parsing or any other errors.
2366: */
2367: int
2368: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2369: {
2370: struct session_state *state = ssh->state;
1.254 djm 2371: const u_char *input, *output;
2372: size_t ilen, olen;
1.201 markus 2373: int r;
2374:
1.249 djm 2375: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2376: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2377: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2378: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2379: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2380: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2381: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2382: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2383: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2384: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2385: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2386: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2387: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2388: return r;
2389: /*
2390: * We set the time here so that in post-auth privsep slave we
2391: * count from the completion of the authentication.
2392: */
2393: state->rekey_time = monotime();
2394: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2395: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2396: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2397: return r;
1.201 markus 2398:
1.239 djm 2399: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2400: return r;
2401:
2402: sshbuf_reset(state->input);
2403: sshbuf_reset(state->output);
2404: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2405: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2406: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2407: (r = sshbuf_put(state->output, output, olen)) != 0)
2408: return r;
2409:
2410: if (sshbuf_len(m))
2411: return SSH_ERR_INVALID_FORMAT;
2412: debug3("%s: done", __func__);
2413: return 0;
2414: }
2415:
2416: /* NEW API */
2417:
2418: /* put data to the outgoing packet */
2419:
2420: int
2421: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2422: {
2423: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2424: }
2425:
2426: int
2427: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2428: {
2429: return sshbuf_putb(ssh->state->outgoing_packet, b);
2430: }
2431:
2432: int
2433: sshpkt_put_u8(struct ssh *ssh, u_char val)
2434: {
2435: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2436: }
2437:
2438: int
2439: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2440: {
2441: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2442: }
2443:
2444: int
2445: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2446: {
2447: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2448: }
2449:
2450: int
2451: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2452: {
2453: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2454: }
2455:
2456: int
2457: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2458: {
2459: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2460: }
2461:
2462: int
2463: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2464: {
2465: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2466: }
2467:
1.211 djm 2468: #ifdef WITH_OPENSSL
1.201 markus 2469: int
2470: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2471: {
2472: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2473: }
2474:
2475:
2476: int
2477: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2478: {
2479: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2480: }
1.211 djm 2481: #endif /* WITH_OPENSSL */
1.201 markus 2482:
2483: /* fetch data from the incoming packet */
2484:
2485: int
2486: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2487: {
2488: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2489: }
2490:
2491: int
2492: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2493: {
2494: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2495: }
2496:
2497: int
2498: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2499: {
2500: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2501: }
2502:
2503: int
2504: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2505: {
2506: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2507: }
2508:
2509: int
2510: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2511: {
2512: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2513: }
2514:
2515: int
2516: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2517: {
2518: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2519: }
2520:
2521: int
2522: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2523: {
2524: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2525: }
2526:
1.211 djm 2527: #ifdef WITH_OPENSSL
1.201 markus 2528: int
2529: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2530: {
2531: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2532: }
2533:
2534:
2535: int
2536: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2537: {
2538: return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2539: }
1.211 djm 2540: #endif /* WITH_OPENSSL */
1.201 markus 2541:
2542: int
2543: sshpkt_get_end(struct ssh *ssh)
2544: {
2545: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2546: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2547: return 0;
2548: }
2549:
2550: const u_char *
2551: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2552: {
2553: if (lenp != NULL)
2554: *lenp = sshbuf_len(ssh->state->incoming_packet);
2555: return sshbuf_ptr(ssh->state->incoming_packet);
2556: }
2557:
2558: /* start a new packet */
2559:
2560: int
2561: sshpkt_start(struct ssh *ssh, u_char type)
2562: {
1.249 djm 2563: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2564:
2565: DBG(debug("packet_start[%d]", type));
1.249 djm 2566: memset(buf, 0, sizeof(buf));
2567: buf[sizeof(buf) - 1] = type;
1.201 markus 2568: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2569: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2570: }
2571:
1.242 markus 2572: static int
2573: ssh_packet_send_mux(struct ssh *ssh)
2574: {
2575: struct session_state *state = ssh->state;
2576: u_char type, *cp;
2577: size_t len;
2578: int r;
2579:
2580: if (ssh->kex)
2581: return SSH_ERR_INTERNAL_ERROR;
2582: len = sshbuf_len(state->outgoing_packet);
2583: if (len < 6)
2584: return SSH_ERR_INTERNAL_ERROR;
2585: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2586: type = cp[5];
2587: if (ssh_packet_log_type(type))
2588: debug3("%s: type %u", __func__, type);
2589: /* drop everything, but the connection protocol */
2590: if (type >= SSH2_MSG_CONNECTION_MIN &&
2591: type <= SSH2_MSG_CONNECTION_MAX) {
2592: POKE_U32(cp, len - 4);
2593: if ((r = sshbuf_putb(state->output,
2594: state->outgoing_packet)) != 0)
2595: return r;
2596: /* sshbuf_dump(state->output, stderr); */
2597: }
2598: sshbuf_reset(state->outgoing_packet);
2599: return 0;
2600: }
2601:
1.201 markus 2602: /* send it */
2603:
2604: int
2605: sshpkt_send(struct ssh *ssh)
2606: {
1.242 markus 2607: if (ssh->state && ssh->state->mux)
2608: return ssh_packet_send_mux(ssh);
1.249 djm 2609: return ssh_packet_send2(ssh);
1.201 markus 2610: }
2611:
2612: int
2613: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2614: {
2615: char buf[1024];
2616: va_list args;
2617: int r;
2618:
2619: va_start(args, fmt);
2620: vsnprintf(buf, sizeof(buf), fmt, args);
2621: va_end(args);
2622:
1.249 djm 2623: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2624: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2625: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2626: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2627: (r = sshpkt_send(ssh)) != 0)
2628: return r;
1.201 markus 2629: return 0;
2630: }
2631:
2632: /* roundup current message to pad bytes */
2633: int
2634: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2635: {
2636: ssh->state->extra_pad = pad;
2637: return 0;
1.1 deraadt 2638: }