Annotation of src/usr.bin/ssh/packet.c, Revision 1.286
1.286 ! deraadt 1: /* $OpenBSD: packet.c,v 1.285 2019/06/07 14:18:48 dtucker 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>
1.278 djm 55: #include <poll.h>
1.142 deraadt 56: #include <signal.h>
1.184 dtucker 57: #include <time.h>
1.1 deraadt 58:
1.201 markus 59: #include <zlib.h>
60:
1.1 deraadt 61: #include "xmalloc.h"
1.25 markus 62: #include "compat.h"
63: #include "ssh2.h"
1.37 markus 64: #include "cipher.h"
1.201 markus 65: #include "sshkey.h"
1.25 markus 66: #include "kex.h"
1.200 markus 67: #include "digest.h"
1.50 markus 68: #include "mac.h"
1.46 markus 69: #include "log.h"
70: #include "canohost.h"
1.87 stevesk 71: #include "misc.h"
1.198 millert 72: #include "channels.h"
1.95 markus 73: #include "ssh.h"
1.201 markus 74: #include "packet.h"
1.197 djm 75: #include "ssherr.h"
1.201 markus 76: #include "sshbuf.h"
1.25 markus 77:
78: #ifdef PACKET_DEBUG
79: #define DBG(x) x
80: #else
81: #define DBG(x)
82: #endif
83:
1.159 markus 84: #define PACKET_MAX_SIZE (256 * 1024)
85:
1.161 andreas 86: struct packet_state {
87: u_int32_t seqnr;
88: u_int32_t packets;
89: u_int64_t blocks;
90: u_int64_t bytes;
91: };
92:
93: struct packet {
94: TAILQ_ENTRY(packet) next;
95: u_char type;
1.201 markus 96: struct sshbuf *payload;
1.161 andreas 97: };
98:
99: struct session_state {
100: /*
101: * This variable contains the file descriptors used for
102: * communicating with the other side. connection_in is used for
103: * reading; connection_out for writing. These can be the same
104: * descriptor, in which case it is assumed to be a socket.
105: */
106: int connection_in;
107: int connection_out;
108:
109: /* Protocol flags for the remote side. */
110: u_int remote_protocol_flags;
1.1 deraadt 111:
1.161 andreas 112: /* Encryption context for receiving data. Only used for decryption. */
1.235 djm 113: struct sshcipher_ctx *receive_context;
1.1 deraadt 114:
1.161 andreas 115: /* Encryption context for sending data. Only used for encryption. */
1.235 djm 116: struct sshcipher_ctx *send_context;
1.14 markus 117:
1.161 andreas 118: /* Buffer for raw input data from the socket. */
1.201 markus 119: struct sshbuf *input;
1.1 deraadt 120:
1.161 andreas 121: /* Buffer for raw output data going to the socket. */
1.201 markus 122: struct sshbuf *output;
1.1 deraadt 123:
1.161 andreas 124: /* Buffer for the partial outgoing packet being constructed. */
1.201 markus 125: struct sshbuf *outgoing_packet;
1.1 deraadt 126:
1.161 andreas 127: /* Buffer for the incoming packet currently being processed. */
1.201 markus 128: struct sshbuf *incoming_packet;
1.1 deraadt 129:
1.161 andreas 130: /* Scratch buffer for packet compression/decompression. */
1.201 markus 131: struct sshbuf *compression_buffer;
132:
133: /* Incoming/outgoing compression dictionaries */
134: z_stream compression_in_stream;
135: z_stream compression_out_stream;
136: int compression_in_started;
137: int compression_out_started;
138: int compression_in_failures;
139: int compression_out_failures;
1.1 deraadt 140:
1.161 andreas 141: /* default maximum packet size */
142: u_int max_packet_size;
1.1 deraadt 143:
1.161 andreas 144: /* Flag indicating whether this module has been initialized. */
145: int initialized;
1.12 markus 146:
1.161 andreas 147: /* Set to true if the connection is interactive. */
148: int interactive_mode;
1.1 deraadt 149:
1.161 andreas 150: /* Set to true if we are the server side. */
151: int server_side;
1.1 deraadt 152:
1.161 andreas 153: /* Set to true if we are authenticated. */
154: int after_authentication;
1.118 markus 155:
1.161 andreas 156: int keep_alive_timeouts;
1.118 markus 157:
1.161 andreas 158: /* The maximum time that we will wait to send or receive a packet */
159: int packet_timeout_ms;
1.151 dtucker 160:
1.161 andreas 161: /* Session key information for Encryption and MAC */
1.201 markus 162: struct newkeys *newkeys[MODE_MAX];
1.161 andreas 163: struct packet_state p_read, p_send;
1.154 dtucker 164:
1.184 dtucker 165: /* Volume-based rekeying */
1.224 dtucker 166: u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
1.105 markus 167:
1.184 dtucker 168: /* Time-based rekeying */
1.208 markus 169: u_int32_t rekey_interval; /* how often in seconds */
1.184 dtucker 170: time_t rekey_time; /* time of last rekeying */
171:
1.161 andreas 172: /* roundup current message to extra_pad bytes */
173: u_char extra_pad;
1.95 markus 174:
1.161 andreas 175: /* XXX discard incoming data after MAC error */
176: u_int packet_discard;
1.234 markus 177: size_t packet_discard_mac_already;
1.201 markus 178: struct sshmac *packet_discard_mac;
1.71 markus 179:
1.161 andreas 180: /* Used in packet_read_poll2() */
181: u_int packlen;
1.159 markus 182:
1.165 andreas 183: /* Used in packet_send2 */
184: int rekeying;
185:
1.242 markus 186: /* Used in ssh_packet_send_mux() */
187: int mux;
188:
1.165 andreas 189: /* Used in packet_set_interactive */
190: int set_interactive_called;
191:
192: /* Used in packet_set_maxsize */
193: int set_maxsize_called;
194:
1.201 markus 195: /* One-off warning about weak ciphers */
196: int cipher_warning_done;
197:
1.243 djm 198: /* Hook for fuzzing inbound packets */
199: ssh_packet_hook_fn *hook_in;
200: void *hook_in_ctx;
201:
1.161 andreas 202: TAILQ_HEAD(, packet) outgoing;
1.105 markus 203: };
1.161 andreas 204:
1.201 markus 205: struct ssh *
206: ssh_alloc_session_state(void)
1.161 andreas 207: {
1.201 markus 208: struct ssh *ssh = NULL;
209: struct session_state *state = NULL;
1.161 andreas 210:
1.201 markus 211: if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
212: (state = calloc(1, sizeof(*state))) == NULL ||
1.278 djm 213: (ssh->kex = kex_new()) == NULL ||
1.201 markus 214: (state->input = sshbuf_new()) == NULL ||
215: (state->output = sshbuf_new()) == NULL ||
216: (state->outgoing_packet = sshbuf_new()) == NULL ||
217: (state->incoming_packet = sshbuf_new()) == NULL)
218: goto fail;
219: TAILQ_INIT(&state->outgoing);
1.202 markus 220: TAILQ_INIT(&ssh->private_keys);
221: TAILQ_INIT(&ssh->public_keys);
1.201 markus 222: state->connection_in = -1;
223: state->connection_out = -1;
224: state->max_packet_size = 32768;
225: state->packet_timeout_ms = -1;
226: state->p_send.packets = state->p_read.packets = 0;
227: state->initialized = 1;
228: /*
229: * ssh_packet_send2() needs to queue packets until
230: * we've done the initial key exchange.
231: */
232: state->rekeying = 1;
233: ssh->state = state;
234: return ssh;
235: fail:
1.278 djm 236: if (ssh) {
237: kex_free(ssh->kex);
238: free(ssh);
239: }
1.201 markus 240: if (state) {
241: sshbuf_free(state->input);
242: sshbuf_free(state->output);
243: sshbuf_free(state->incoming_packet);
244: sshbuf_free(state->outgoing_packet);
245: free(state);
246: }
247: return NULL;
1.161 andreas 248: }
1.105 markus 249:
1.243 djm 250: void
251: ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
252: {
253: ssh->state->hook_in = hook;
254: ssh->state->hook_in_ctx = ctx;
255: }
256:
1.228 djm 257: /* Returns nonzero if rekeying is in progress */
258: int
259: ssh_packet_is_rekeying(struct ssh *ssh)
260: {
1.278 djm 261: return ssh->state->rekeying || ssh->kex->done == 0;
1.228 djm 262: }
263:
1.16 markus 264: /*
1.253 naddy 265: * Sets the descriptors used for communication.
1.16 markus 266: */
1.201 markus 267: struct ssh *
268: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1 deraadt 269: {
1.201 markus 270: struct session_state *state;
271: const struct sshcipher *none = cipher_by_name("none");
1.197 djm 272: int r;
1.97 deraadt 273:
1.205 djm 274: if (none == NULL) {
275: error("%s: cannot load cipher 'none'", __func__);
276: return NULL;
277: }
1.201 markus 278: if (ssh == NULL)
279: ssh = ssh_alloc_session_state();
1.205 djm 280: if (ssh == NULL) {
1.285 dtucker 281: error("%s: could not allocate state", __func__);
1.205 djm 282: return NULL;
283: }
1.201 markus 284: state = ssh->state;
285: state->connection_in = fd_in;
286: state->connection_out = fd_out;
287: if ((r = cipher_init(&state->send_context, none,
1.197 djm 288: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201 markus 289: (r = cipher_init(&state->receive_context, none,
1.205 djm 290: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
291: error("%s: cipher_init failed: %s", __func__, ssh_err(r));
1.230 djm 292: free(ssh); /* XXX need ssh_free_session_state? */
1.205 djm 293: return NULL;
294: }
1.201 markus 295: state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
1.207 djm 296: /*
297: * Cache the IP address of the remote connection for use in error
298: * messages that might be generated after the connection has closed.
299: */
300: (void)ssh_remote_ipaddr(ssh);
1.201 markus 301: return ssh;
1.1 deraadt 302: }
303:
1.154 dtucker 304: void
1.201 markus 305: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 306: {
1.201 markus 307: struct session_state *state = ssh->state;
308:
1.174 djm 309: if (timeout <= 0 || count <= 0) {
1.201 markus 310: state->packet_timeout_ms = -1;
1.154 dtucker 311: return;
312: }
313: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 314: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 315: else
1.201 markus 316: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 317: }
318:
1.242 markus 319: void
320: ssh_packet_set_mux(struct ssh *ssh)
321: {
322: ssh->state->mux = 1;
323: ssh->state->rekeying = 0;
324: }
325:
326: int
327: ssh_packet_get_mux(struct ssh *ssh)
328: {
329: return ssh->state->mux;
330: }
331:
1.201 markus 332: int
1.245 djm 333: ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
334: {
335: va_list args;
336: int r;
337:
338: free(ssh->log_preamble);
339: if (fmt == NULL)
340: ssh->log_preamble = NULL;
341: else {
342: va_start(args, fmt);
343: r = vasprintf(&ssh->log_preamble, fmt, args);
344: va_end(args);
345: if (r < 0 || ssh->log_preamble == NULL)
346: return SSH_ERR_ALLOC_FAIL;
347: }
348: return 0;
349: }
350:
351: int
1.201 markus 352: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 353: {
1.201 markus 354: struct session_state *state = ssh->state;
355: int r;
356:
357: if (state->packet_discard_mac) {
1.159 markus 358: char buf[1024];
1.234 markus 359: size_t dlen = PACKET_MAX_SIZE;
1.201 markus 360:
1.234 markus 361: if (dlen > state->packet_discard_mac_already)
362: dlen -= state->packet_discard_mac_already;
1.159 markus 363: memset(buf, 'a', sizeof(buf));
1.234 markus 364: while (sshbuf_len(state->incoming_packet) < dlen)
1.201 markus 365: if ((r = sshbuf_put(state->incoming_packet, buf,
366: sizeof(buf))) != 0)
367: return r;
368: (void) mac_compute(state->packet_discard_mac,
369: state->p_read.seqnr,
1.234 markus 370: sshbuf_ptr(state->incoming_packet), dlen,
1.201 markus 371: NULL, 0);
1.159 markus 372: }
1.220 djm 373: logit("Finished discarding for %.200s port %d",
374: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 375: return SSH_ERR_MAC_INVALID;
1.159 markus 376: }
377:
1.201 markus 378: static int
379: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
1.234 markus 380: struct sshmac *mac, size_t mac_already, u_int discard)
1.159 markus 381: {
1.201 markus 382: struct session_state *state = ssh->state;
383: int r;
384:
385: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
386: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
387: return r;
388: return SSH_ERR_MAC_INVALID;
389: }
1.234 markus 390: /*
391: * Record number of bytes over which the mac has already
392: * been computed in order to minimize timing attacks.
393: */
394: if (mac && mac->enabled) {
1.201 markus 395: state->packet_discard_mac = mac;
1.234 markus 396: state->packet_discard_mac_already = mac_already;
397: }
398: if (sshbuf_len(state->input) >= discard)
399: return ssh_packet_stop_discard(ssh);
1.201 markus 400: state->packet_discard = discard - sshbuf_len(state->input);
401: return 0;
1.159 markus 402: }
403:
1.19 markus 404: /* Returns 1 if remote host is connected via socket, 0 if not. */
405:
406: int
1.201 markus 407: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 408: {
1.271 djm 409: struct session_state *state;
1.19 markus 410: struct sockaddr_storage from, to;
411: socklen_t fromlen, tolen;
412:
1.271 djm 413: if (ssh == NULL || ssh->state == NULL)
414: return 0;
415:
416: state = ssh->state;
1.230 djm 417: if (state->connection_in == -1 || state->connection_out == -1)
418: return 0;
1.19 markus 419: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 420: if (state->connection_in == state->connection_out)
1.19 markus 421: return 1;
422: fromlen = sizeof(from);
423: memset(&from, 0, sizeof(from));
1.201 markus 424: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.286 ! deraadt 425: &fromlen) == -1)
1.19 markus 426: return 0;
427: tolen = sizeof(to);
428: memset(&to, 0, sizeof(to));
1.201 markus 429: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.286 ! deraadt 430: &tolen) == -1)
1.19 markus 431: return 0;
432: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
433: return 0;
434: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
435: return 0;
436: return 1;
437: }
438:
1.91 markus 439: void
1.201 markus 440: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 441: {
1.201 markus 442: if (ibytes)
443: *ibytes = ssh->state->p_read.bytes;
444: if (obytes)
445: *obytes = ssh->state->p_send.bytes;
1.91 markus 446: }
1.125 deraadt 447:
1.91 markus 448: int
1.201 markus 449: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 450: {
451: struct sockaddr_storage to;
1.21 deraadt 452: socklen_t tolen = sizeof(to);
1.19 markus 453:
454: memset(&to, 0, sizeof(to));
1.201 markus 455: if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
1.286 ! deraadt 456: &tolen) == -1)
1.19 markus 457: return 0;
1.173 djm 458: return to.ss_family;
1.19 markus 459: }
460:
1.1 deraadt 461: /* Sets the connection into non-blocking mode. */
462:
1.2 provos 463: void
1.201 markus 464: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 465: {
1.14 markus 466: /* Set the socket into non-blocking mode. */
1.201 markus 467: set_nonblock(ssh->state->connection_in);
1.14 markus 468:
1.201 markus 469: if (ssh->state->connection_out != ssh->state->connection_in)
470: set_nonblock(ssh->state->connection_out);
1.1 deraadt 471: }
472:
473: /* Returns the socket used for reading. */
474:
1.2 provos 475: int
1.201 markus 476: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 477: {
1.201 markus 478: return ssh->state->connection_in;
1.1 deraadt 479: }
480:
481: /* Returns the descriptor used for writing. */
482:
1.2 provos 483: int
1.201 markus 484: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 485: {
1.201 markus 486: return ssh->state->connection_out;
487: }
488:
489: /*
490: * Returns the IP-address of the remote host as a string. The returned
491: * string must not be freed.
492: */
493:
494: const char *
495: ssh_remote_ipaddr(struct ssh *ssh)
496: {
1.271 djm 497: int sock;
1.220 djm 498:
1.201 markus 499: /* Check whether we have cached the ipaddr. */
1.220 djm 500: if (ssh->remote_ipaddr == NULL) {
501: if (ssh_packet_connection_is_on_socket(ssh)) {
1.271 djm 502: sock = ssh->state->connection_in;
1.220 djm 503: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 djm 504: ssh->remote_port = get_peer_port(sock);
505: ssh->local_ipaddr = get_local_ipaddr(sock);
506: ssh->local_port = get_local_port(sock);
1.220 djm 507: } else {
508: ssh->remote_ipaddr = strdup("UNKNOWN");
1.230 djm 509: ssh->remote_port = 65535;
510: ssh->local_ipaddr = strdup("UNKNOWN");
511: ssh->local_port = 65535;
1.220 djm 512: }
513: }
1.201 markus 514: return ssh->remote_ipaddr;
1.1 deraadt 515: }
516:
1.220 djm 517: /* Returns the port number of the remote host. */
518:
519: int
520: ssh_remote_port(struct ssh *ssh)
521: {
522: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
523: return ssh->remote_port;
1.230 djm 524: }
525:
526: /*
527: * Returns the IP-address of the local host as a string. The returned
528: * string must not be freed.
529: */
530:
531: const char *
532: ssh_local_ipaddr(struct ssh *ssh)
533: {
534: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
535: return ssh->local_ipaddr;
536: }
537:
538: /* Returns the port number of the local host. */
539:
540: int
541: ssh_local_port(struct ssh *ssh)
542: {
543: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
544: return ssh->local_port;
1.266 djm 545: }
546:
547: /* Returns the routing domain of the input socket, or NULL if unavailable */
548: const char *
549: ssh_packet_rdomain_in(struct ssh *ssh)
550: {
551: if (ssh->rdomain_in != NULL)
552: return ssh->rdomain_in;
553: if (!ssh_packet_connection_is_on_socket(ssh))
554: return NULL;
555: ssh->rdomain_in = get_rdomain(ssh->state->connection_in);
556: return ssh->rdomain_in;
1.220 djm 557: }
558:
1.1 deraadt 559: /* Closes the connection and clears and frees internal data structures. */
560:
1.257 markus 561: static void
562: ssh_packet_close_internal(struct ssh *ssh, int do_close)
1.1 deraadt 563: {
1.201 markus 564: struct session_state *state = ssh->state;
565: u_int mode;
566:
567: if (!state->initialized)
1.14 markus 568: return;
1.201 markus 569: state->initialized = 0;
1.257 markus 570: if (do_close) {
571: if (state->connection_in == state->connection_out) {
572: close(state->connection_out);
573: } else {
574: close(state->connection_in);
575: close(state->connection_out);
576: }
1.14 markus 577: }
1.201 markus 578: sshbuf_free(state->input);
579: sshbuf_free(state->output);
580: sshbuf_free(state->outgoing_packet);
581: sshbuf_free(state->incoming_packet);
1.257 markus 582: for (mode = 0; mode < MODE_MAX; mode++) {
583: kex_free_newkeys(state->newkeys[mode]); /* current keys */
584: state->newkeys[mode] = NULL;
585: ssh_clear_newkeys(ssh, mode); /* next keys */
586: }
587: /* comression state is in shared mem, so we can only release it once */
588: if (do_close && state->compression_buffer) {
1.201 markus 589: sshbuf_free(state->compression_buffer);
590: if (state->compression_out_started) {
591: z_streamp stream = &state->compression_out_stream;
592: debug("compress outgoing: "
593: "raw data %llu, compressed %llu, factor %.2f",
594: (unsigned long long)stream->total_in,
595: (unsigned long long)stream->total_out,
596: stream->total_in == 0 ? 0.0 :
597: (double) stream->total_out / stream->total_in);
598: if (state->compression_out_failures == 0)
599: deflateEnd(stream);
600: }
601: if (state->compression_in_started) {
1.260 dtucker 602: z_streamp stream = &state->compression_in_stream;
1.201 markus 603: debug("compress incoming: "
604: "raw data %llu, compressed %llu, factor %.2f",
605: (unsigned long long)stream->total_out,
606: (unsigned long long)stream->total_in,
607: stream->total_out == 0 ? 0.0 :
608: (double) stream->total_in / stream->total_out);
609: if (state->compression_in_failures == 0)
610: inflateEnd(stream);
611: }
1.14 markus 612: }
1.235 djm 613: cipher_free(state->send_context);
614: cipher_free(state->receive_context);
615: state->send_context = state->receive_context = NULL;
1.257 markus 616: if (do_close) {
1.277 djm 617: free(ssh->local_ipaddr);
618: ssh->local_ipaddr = NULL;
1.257 markus 619: free(ssh->remote_ipaddr);
620: ssh->remote_ipaddr = NULL;
621: free(ssh->state);
622: ssh->state = NULL;
623: }
624: }
625:
626: void
627: ssh_packet_close(struct ssh *ssh)
628: {
629: ssh_packet_close_internal(ssh, 1);
630: }
631:
632: void
633: ssh_packet_clear_keys(struct ssh *ssh)
634: {
635: ssh_packet_close_internal(ssh, 0);
1.1 deraadt 636: }
637:
638: /* Sets remote side protocol flags. */
639:
1.2 provos 640: void
1.201 markus 641: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 642: {
1.201 markus 643: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 644: }
645:
646: /* Returns the remote protocol flags set earlier by the above function. */
647:
1.40 markus 648: u_int
1.201 markus 649: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 650: {
1.201 markus 651: return ssh->state->remote_protocol_flags;
1.1 deraadt 652: }
653:
1.16 markus 654: /*
655: * Starts packet compression from the next packet on in both directions.
656: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
657: */
1.1 deraadt 658:
1.201 markus 659: static int
660: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 661: {
1.201 markus 662: if (!ssh->state->compression_buffer &&
663: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
664: return SSH_ERR_ALLOC_FAIL;
665: return 0;
1.60 markus 666: }
667:
1.201 markus 668: static int
669: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 670: {
1.201 markus 671: if (level < 1 || level > 9)
672: return SSH_ERR_INVALID_ARGUMENT;
673: debug("Enabling compression at level %d.", level);
674: if (ssh->state->compression_out_started == 1)
675: deflateEnd(&ssh->state->compression_out_stream);
676: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
677: case Z_OK:
678: ssh->state->compression_out_started = 1;
679: break;
680: case Z_MEM_ERROR:
681: return SSH_ERR_ALLOC_FAIL;
682: default:
683: return SSH_ERR_INTERNAL_ERROR;
684: }
685: return 0;
1.1 deraadt 686: }
687:
1.201 markus 688: static int
689: start_compression_in(struct ssh *ssh)
690: {
691: if (ssh->state->compression_in_started == 1)
692: inflateEnd(&ssh->state->compression_in_stream);
693: switch (inflateInit(&ssh->state->compression_in_stream)) {
694: case Z_OK:
695: ssh->state->compression_in_started = 1;
696: break;
697: case Z_MEM_ERROR:
698: return SSH_ERR_ALLOC_FAIL;
699: default:
700: return SSH_ERR_INTERNAL_ERROR;
701: }
702: return 0;
1.95 markus 703: }
704:
1.201 markus 705: /* XXX remove need for separate compression buffer */
706: static int
707: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 708: {
1.201 markus 709: u_char buf[4096];
710: int r, status;
711:
712: if (ssh->state->compression_out_started != 1)
713: return SSH_ERR_INTERNAL_ERROR;
714:
715: /* This case is not handled below. */
716: if (sshbuf_len(in) == 0)
717: return 0;
718:
719: /* Input is the contents of the input buffer. */
720: if ((ssh->state->compression_out_stream.next_in =
721: sshbuf_mutable_ptr(in)) == NULL)
722: return SSH_ERR_INTERNAL_ERROR;
723: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
724:
725: /* Loop compressing until deflate() returns with avail_out != 0. */
726: do {
727: /* Set up fixed-size output buffer. */
728: ssh->state->compression_out_stream.next_out = buf;
729: ssh->state->compression_out_stream.avail_out = sizeof(buf);
730:
731: /* Compress as much data into the buffer as possible. */
732: status = deflate(&ssh->state->compression_out_stream,
733: Z_PARTIAL_FLUSH);
734: switch (status) {
735: case Z_MEM_ERROR:
736: return SSH_ERR_ALLOC_FAIL;
737: case Z_OK:
738: /* Append compressed data to output_buffer. */
739: if ((r = sshbuf_put(out, buf, sizeof(buf) -
740: ssh->state->compression_out_stream.avail_out)) != 0)
741: return r;
742: break;
743: case Z_STREAM_ERROR:
744: default:
745: ssh->state->compression_out_failures++;
746: return SSH_ERR_INVALID_FORMAT;
747: }
748: } while (ssh->state->compression_out_stream.avail_out == 0);
749: return 0;
1.1 deraadt 750: }
751:
1.201 markus 752: static int
753: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 754: {
1.201 markus 755: u_char buf[4096];
756: int r, status;
1.1 deraadt 757:
1.201 markus 758: if (ssh->state->compression_in_started != 1)
759: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 760:
1.201 markus 761: if ((ssh->state->compression_in_stream.next_in =
762: sshbuf_mutable_ptr(in)) == NULL)
763: return SSH_ERR_INTERNAL_ERROR;
764: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 765:
1.201 markus 766: for (;;) {
767: /* Set up fixed-size output buffer. */
768: ssh->state->compression_in_stream.next_out = buf;
769: ssh->state->compression_in_stream.avail_out = sizeof(buf);
770:
771: status = inflate(&ssh->state->compression_in_stream,
772: Z_PARTIAL_FLUSH);
773: switch (status) {
774: case Z_OK:
775: if ((r = sshbuf_put(out, buf, sizeof(buf) -
776: ssh->state->compression_in_stream.avail_out)) != 0)
777: return r;
778: break;
779: case Z_BUF_ERROR:
780: /*
781: * Comments in zlib.h say that we should keep calling
782: * inflate() until we get an error. This appears to
783: * be the error that we get.
784: */
785: return 0;
786: case Z_DATA_ERROR:
787: return SSH_ERR_INVALID_FORMAT;
788: case Z_MEM_ERROR:
789: return SSH_ERR_ALLOC_FAIL;
790: case Z_STREAM_ERROR:
791: default:
792: ssh->state->compression_in_failures++;
793: return SSH_ERR_INTERNAL_ERROR;
794: }
795: }
796: /* NOTREACHED */
1.170 djm 797: }
798:
1.257 markus 799: void
800: ssh_clear_newkeys(struct ssh *ssh, int mode)
801: {
1.259 djm 802: if (ssh->kex && ssh->kex->newkeys[mode]) {
1.257 markus 803: kex_free_newkeys(ssh->kex->newkeys[mode]);
804: ssh->kex->newkeys[mode] = NULL;
805: }
806: }
807:
1.201 markus 808: int
809: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 810: {
1.201 markus 811: struct session_state *state = ssh->state;
812: struct sshenc *enc;
813: struct sshmac *mac;
814: struct sshcomp *comp;
1.235 djm 815: struct sshcipher_ctx **ccp;
1.236 markus 816: struct packet_state *ps;
1.105 markus 817: u_int64_t *max_blocks;
1.259 djm 818: const char *wmsg;
1.197 djm 819: int r, crypt_type;
1.283 djm 820: const char *dir = mode == MODE_OUT ? "out" : "in";
1.57 markus 821:
1.100 markus 822: debug2("set_newkeys: mode %d", mode);
1.57 markus 823:
1.88 markus 824: if (mode == MODE_OUT) {
1.235 djm 825: ccp = &state->send_context;
1.115 avsm 826: crypt_type = CIPHER_ENCRYPT;
1.236 markus 827: ps = &state->p_send;
1.201 markus 828: max_blocks = &state->max_blocks_out;
1.88 markus 829: } else {
1.235 djm 830: ccp = &state->receive_context;
1.115 avsm 831: crypt_type = CIPHER_DECRYPT;
1.236 markus 832: ps = &state->p_read;
1.201 markus 833: max_blocks = &state->max_blocks_in;
1.88 markus 834: }
1.201 markus 835: if (state->newkeys[mode] != NULL) {
1.283 djm 836: debug("%s: rekeying %s, input %llu bytes %llu blocks, "
837: "output %llu bytes %llu blocks", __func__, dir,
1.257 markus 838: (unsigned long long)state->p_read.bytes,
839: (unsigned long long)state->p_read.blocks,
840: (unsigned long long)state->p_send.bytes,
841: (unsigned long long)state->p_send.blocks);
842: kex_free_newkeys(state->newkeys[mode]);
843: state->newkeys[mode] = NULL;
1.57 markus 844: }
1.236 markus 845: /* note that both bytes and the seqnr are not reset */
846: ps->packets = ps->blocks = 0;
1.201 markus 847: /* move newkeys from kex to state */
848: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
849: return SSH_ERR_INTERNAL_ERROR;
850: ssh->kex->newkeys[mode] = NULL;
851: enc = &state->newkeys[mode]->enc;
852: mac = &state->newkeys[mode]->mac;
853: comp = &state->newkeys[mode]->comp;
854: if (cipher_authlen(enc->cipher) == 0) {
855: if ((r = mac_init(mac)) != 0)
856: return r;
857: }
858: mac->enabled = 1;
1.283 djm 859: DBG(debug("%s: cipher_init_context: %s", __func__, dir));
1.279 djm 860: cipher_free(*ccp);
861: *ccp = NULL;
1.235 djm 862: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 863: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 864: return r;
865: if (!state->cipher_warning_done &&
1.235 djm 866: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 867: error("Warning: %s", wmsg);
868: state->cipher_warning_done = 1;
869: }
1.91 markus 870: /* Deleting the keys does not gain extra security */
1.192 djm 871: /* explicit_bzero(enc->iv, enc->block_size);
872: explicit_bzero(enc->key, enc->key_len);
873: explicit_bzero(mac->key, mac->key_len); */
1.275 sf 874: if ((comp->type == COMP_ZLIB ||
875: (comp->type == COMP_DELAYED &&
876: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 877: if ((r = ssh_packet_init_compression(ssh)) < 0)
878: return r;
879: if (mode == MODE_OUT) {
880: if ((r = start_compression_out(ssh, 6)) != 0)
881: return r;
882: } else {
883: if ((r = start_compression_in(ssh)) != 0)
884: return r;
885: }
1.57 markus 886: comp->enabled = 1;
887: }
1.109 markus 888: /*
889: * The 2^(blocksize*2) limit is too expensive for 3DES,
1.254 djm 890: * so enforce a 1GB limit for small blocksizes.
1.261 dtucker 891: * See RFC4344 section 3.2.
1.109 markus 892: */
893: if (enc->block_size >= 16)
894: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
895: else
896: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 897: if (state->rekey_limit)
1.237 deraadt 898: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 899: state->rekey_limit / enc->block_size);
1.283 djm 900: debug("rekey %s after %llu blocks", dir,
901: (unsigned long long)*max_blocks);
1.201 markus 902: return 0;
1.57 markus 903: }
904:
1.228 djm 905: #define MAX_PACKETS (1U<<31)
906: static int
907: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
908: {
909: struct session_state *state = ssh->state;
910: u_int32_t out_blocks;
911:
912: /* XXX client can't cope with rekeying pre-auth */
913: if (!state->after_authentication)
914: return 0;
915:
916: /* Haven't keyed yet or KEX in progress. */
1.278 djm 917: if (ssh_packet_is_rekeying(ssh))
1.228 djm 918: return 0;
919:
920: /* Peer can't rekey */
921: if (ssh->compat & SSH_BUG_NOREKEY)
922: return 0;
923:
924: /*
925: * Permit one packet in or out per rekey - this allows us to
926: * make progress when rekey limits are very small.
927: */
928: if (state->p_send.packets == 0 && state->p_read.packets == 0)
929: return 0;
930:
931: /* Time-based rekeying */
932: if (state->rekey_interval != 0 &&
1.244 dtucker 933: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 934: return 1;
935:
1.261 dtucker 936: /*
937: * Always rekey when MAX_PACKETS sent in either direction
938: * As per RFC4344 section 3.1 we do this after 2^31 packets.
939: */
1.228 djm 940: if (state->p_send.packets > MAX_PACKETS ||
941: state->p_read.packets > MAX_PACKETS)
942: return 1;
943:
944: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 945: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 946: state->newkeys[MODE_OUT]->enc.block_size);
947: return (state->max_blocks_out &&
948: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
949: (state->max_blocks_in &&
950: (state->p_read.blocks > state->max_blocks_in));
951: }
952:
1.16 markus 953: /*
1.118 markus 954: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 955: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 956: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
957: */
1.201 markus 958: static int
959: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 960: {
1.201 markus 961: struct session_state *state = ssh->state;
962: struct sshcomp *comp = NULL;
963: int r, mode;
1.118 markus 964:
965: /*
966: * Remember that we are past the authentication step, so rekeying
1.275 sf 967: * with COMP_DELAYED will turn on compression immediately.
1.118 markus 968: */
1.201 markus 969: state->after_authentication = 1;
1.118 markus 970: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 971: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 972: if (state->newkeys[mode] == NULL)
1.145 markus 973: continue;
1.201 markus 974: comp = &state->newkeys[mode]->comp;
1.275 sf 975: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 976: if ((r = ssh_packet_init_compression(ssh)) != 0)
977: return r;
978: if (mode == MODE_OUT) {
979: if ((r = start_compression_out(ssh, 6)) != 0)
980: return r;
981: } else {
982: if ((r = start_compression_in(ssh)) != 0)
983: return r;
984: }
1.118 markus 985: comp->enabled = 1;
986: }
987: }
1.201 markus 988: return 0;
1.118 markus 989: }
990:
1.226 djm 991: /* Used to mute debug logging for noisy packet types */
1.242 markus 992: int
1.226 djm 993: ssh_packet_log_type(u_char type)
994: {
995: switch (type) {
996: case SSH2_MSG_CHANNEL_DATA:
997: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
998: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
999: return 0;
1000: default:
1001: return 1;
1002: }
1003: }
1004:
1.118 markus 1005: /*
1.25 markus 1006: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1007: */
1.201 markus 1008: int
1009: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1010: {
1.201 markus 1011: struct session_state *state = ssh->state;
1.200 markus 1012: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1013: u_char tmp, padlen, pad = 0;
1.201 markus 1014: u_int authlen = 0, aadlen = 0;
1015: u_int len;
1016: struct sshenc *enc = NULL;
1017: struct sshmac *mac = NULL;
1018: struct sshcomp *comp = NULL;
1019: int r, block_size;
1020:
1021: if (state->newkeys[MODE_OUT] != NULL) {
1022: enc = &state->newkeys[MODE_OUT]->enc;
1023: mac = &state->newkeys[MODE_OUT]->mac;
1024: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1025: /* disable mac for authenticated encryption */
1026: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1027: mac = NULL;
1.25 markus 1028: }
1.88 markus 1029: block_size = enc ? enc->block_size : 8;
1.180 markus 1030: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1031:
1.201 markus 1032: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1033: if (ssh_packet_log_type(type))
1034: debug3("send packet: type %u", type);
1.25 markus 1035: #ifdef PACKET_DEBUG
1036: fprintf(stderr, "plain: ");
1.201 markus 1037: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1038: #endif
1039:
1040: if (comp && comp->enabled) {
1.201 markus 1041: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1042: /* skip header, compress only payload */
1.201 markus 1043: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1044: goto out;
1045: sshbuf_reset(state->compression_buffer);
1046: if ((r = compress_buffer(ssh, state->outgoing_packet,
1047: state->compression_buffer)) != 0)
1048: goto out;
1049: sshbuf_reset(state->outgoing_packet);
1050: if ((r = sshbuf_put(state->outgoing_packet,
1051: "\0\0\0\0\0", 5)) != 0 ||
1052: (r = sshbuf_putb(state->outgoing_packet,
1053: state->compression_buffer)) != 0)
1054: goto out;
1055: DBG(debug("compression: raw %d compressed %zd", len,
1056: sshbuf_len(state->outgoing_packet)));
1.25 markus 1057: }
1058:
1059: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1060: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1061:
1062: /*
1063: * calc size of padding, alloc space, get random data,
1064: * minimum padding is 4 bytes
1065: */
1.178 markus 1066: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1067: padlen = block_size - (len % block_size);
1068: if (padlen < 4)
1069: padlen += block_size;
1.201 markus 1070: if (state->extra_pad) {
1.233 djm 1071: tmp = state->extra_pad;
1.201 markus 1072: state->extra_pad =
1.237 deraadt 1073: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1074: /* check if roundup overflowed */
1075: if (state->extra_pad < tmp)
1076: return SSH_ERR_INVALID_ARGUMENT;
1077: tmp = (len + padlen) % state->extra_pad;
1078: /* Check whether pad calculation below will underflow */
1079: if (tmp > state->extra_pad)
1080: return SSH_ERR_INVALID_ARGUMENT;
1081: pad = state->extra_pad - tmp;
1.193 djm 1082: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1083: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1084: tmp = padlen;
1.71 markus 1085: padlen += pad;
1.233 djm 1086: /* Check whether padlen calculation overflowed */
1087: if (padlen < tmp)
1088: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1089: state->extra_pad = 0;
1.71 markus 1090: }
1.201 markus 1091: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1092: goto out;
1.235 djm 1093: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1094: /* random padding */
1.201 markus 1095: arc4random_buf(cp, padlen);
1.32 markus 1096: } else {
1097: /* clear padding */
1.192 djm 1098: explicit_bzero(cp, padlen);
1.25 markus 1099: }
1.178 markus 1100: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1101: len = sshbuf_len(state->outgoing_packet);
1102: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1103: if (cp == NULL) {
1104: r = SSH_ERR_INTERNAL_ERROR;
1105: goto out;
1106: }
1.25 markus 1107: /* packet_length includes payload, padding and padding length field */
1.201 markus 1108: POKE_U32(cp, len - 4);
1.89 markus 1109: cp[4] = padlen;
1.178 markus 1110: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1111: len, padlen, aadlen));
1.25 markus 1112:
1113: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1114: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1115: if ((r = mac_compute(mac, state->p_send.seqnr,
1116: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1117: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1118: goto out;
1119: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1120: }
1121: /* encrypt packet and append to output buffer. */
1.201 markus 1122: if ((r = sshbuf_reserve(state->output,
1123: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1124: goto out;
1.235 djm 1125: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1126: sshbuf_ptr(state->outgoing_packet),
1127: len - aadlen, aadlen, authlen)) != 0)
1128: goto out;
1.25 markus 1129: /* append unencrypted MAC */
1.178 markus 1130: if (mac && mac->enabled) {
1131: if (mac->etm) {
1132: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1133: if ((r = mac_compute(mac, state->p_send.seqnr,
1134: cp, len, macbuf, sizeof(macbuf))) != 0)
1135: goto out;
1.178 markus 1136: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1137: state->p_send.seqnr));
1.178 markus 1138: }
1.201 markus 1139: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1140: goto out;
1.178 markus 1141: }
1.25 markus 1142: #ifdef PACKET_DEBUG
1143: fprintf(stderr, "encrypted: ");
1.201 markus 1144: sshbuf_dump(state->output, stderr);
1.25 markus 1145: #endif
1.29 markus 1146: /* increment sequence number for outgoing packets */
1.201 markus 1147: if (++state->p_send.seqnr == 0)
1.106 itojun 1148: logit("outgoing seqnr wraps around");
1.201 markus 1149: if (++state->p_send.packets == 0)
1150: if (!(ssh->compat & SSH_BUG_NOREKEY))
1151: return SSH_ERR_NEED_REKEY;
1152: state->p_send.blocks += len / block_size;
1153: state->p_send.bytes += len;
1154: sshbuf_reset(state->outgoing_packet);
1.25 markus 1155:
1.57 markus 1156: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1157: r = ssh_set_newkeys(ssh, MODE_OUT);
1158: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1159: r = ssh_packet_enable_delayed_compress(ssh);
1160: else
1161: r = 0;
1162: out:
1163: return r;
1.25 markus 1164: }
1165:
1.228 djm 1166: /* returns non-zero if the specified packet type is usec by KEX */
1167: static int
1168: ssh_packet_type_is_kex(u_char type)
1169: {
1170: return
1171: type >= SSH2_MSG_TRANSPORT_MIN &&
1172: type <= SSH2_MSG_TRANSPORT_MAX &&
1173: type != SSH2_MSG_SERVICE_REQUEST &&
1174: type != SSH2_MSG_SERVICE_ACCEPT &&
1175: type != SSH2_MSG_EXT_INFO;
1176: }
1177:
1.201 markus 1178: int
1179: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1180: {
1.201 markus 1181: struct session_state *state = ssh->state;
1.105 markus 1182: struct packet *p;
1.201 markus 1183: u_char type;
1.228 djm 1184: int r, need_rekey;
1.105 markus 1185:
1.228 djm 1186: if (sshbuf_len(state->outgoing_packet) < 6)
1187: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1188: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1189: need_rekey = !ssh_packet_type_is_kex(type) &&
1190: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1191:
1.228 djm 1192: /*
1193: * During rekeying we can only send key exchange messages.
1194: * Queue everything else.
1195: */
1196: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1197: if (need_rekey)
1198: debug3("%s: rekex triggered", __func__);
1199: debug("enqueue packet: %u", type);
1200: p = calloc(1, sizeof(*p));
1201: if (p == NULL)
1202: return SSH_ERR_ALLOC_FAIL;
1203: p->type = type;
1204: p->payload = state->outgoing_packet;
1205: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1206: state->outgoing_packet = sshbuf_new();
1207: if (state->outgoing_packet == NULL)
1208: return SSH_ERR_ALLOC_FAIL;
1209: if (need_rekey) {
1210: /*
1211: * This packet triggered a rekey, so send the
1212: * KEXINIT now.
1213: * NB. reenters this function via kex_start_rekex().
1214: */
1215: return kex_start_rekex(ssh);
1.105 markus 1216: }
1.228 djm 1217: return 0;
1.105 markus 1218: }
1219:
1220: /* rekeying starts with sending KEXINIT */
1221: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1222: state->rekeying = 1;
1.105 markus 1223:
1.201 markus 1224: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1225: return r;
1.105 markus 1226:
1227: /* after a NEWKEYS message we can send the complete queue */
1228: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1229: state->rekeying = 0;
1230: state->rekey_time = monotime();
1231: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1232: type = p->type;
1.228 djm 1233: /*
1234: * If this packet triggers a rekex, then skip the
1235: * remaining packets in the queue for now.
1236: * NB. re-enters this function via kex_start_rekex.
1237: */
1238: if (ssh_packet_need_rekeying(ssh,
1239: sshbuf_len(p->payload))) {
1240: debug3("%s: queued packet triggered rekex",
1241: __func__);
1242: return kex_start_rekex(ssh);
1243: }
1.105 markus 1244: debug("dequeue packet: %u", type);
1.201 markus 1245: sshbuf_free(state->outgoing_packet);
1246: state->outgoing_packet = p->payload;
1247: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1248: memset(p, 0, sizeof(*p));
1.186 djm 1249: free(p);
1.201 markus 1250: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1251: return r;
1.105 markus 1252: }
1253: }
1.201 markus 1254: return 0;
1.25 markus 1255: }
1256:
1257: /*
1.16 markus 1258: * Waits until a packet has been received, and returns its type. Note that
1259: * no other data is processed until this returns, so this function should not
1260: * be used during the interactive session.
1261: */
1.1 deraadt 1262:
1.2 provos 1263: int
1.201 markus 1264: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1265: {
1.201 markus 1266: struct session_state *state = ssh->state;
1.222 markus 1267: int len, r, ms_remain;
1.56 millert 1268: fd_set *setp;
1.14 markus 1269: char buf[8192];
1.155 deraadt 1270: struct timeval timeout, start, *timeoutp = NULL;
1271:
1.25 markus 1272: DBG(debug("packet_read()"));
1.14 markus 1273:
1.214 deraadt 1274: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1275: NFDBITS), sizeof(fd_mask));
1.201 markus 1276: if (setp == NULL)
1277: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1278:
1.205 djm 1279: /*
1280: * Since we are blocking, ensure that all written packets have
1281: * been sent.
1282: */
1.210 markus 1283: if ((r = ssh_packet_write_wait(ssh)) != 0)
1284: goto out;
1.14 markus 1285:
1286: /* Stay in the loop until we have received a complete packet. */
1287: for (;;) {
1288: /* Try to read a packet from the buffer. */
1.201 markus 1289: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1290: if (r != 0)
1291: break;
1.14 markus 1292: /* If we got a packet, return it. */
1.201 markus 1293: if (*typep != SSH_MSG_NONE)
1294: break;
1.16 markus 1295: /*
1296: * Otherwise, wait for some data to arrive, add it to the
1297: * buffer, and try again.
1298: */
1.201 markus 1299: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1300: NFDBITS) * sizeof(fd_mask));
1.201 markus 1301: FD_SET(state->connection_in, setp);
1.16 markus 1302:
1.201 markus 1303: if (state->packet_timeout_ms > 0) {
1304: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1305: timeoutp = &timeout;
1306: }
1.14 markus 1307: /* Wait for some data to arrive. */
1.154 dtucker 1308: for (;;) {
1.201 markus 1309: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1310: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1311: monotime_tv(&start);
1.154 dtucker 1312: }
1.201 markus 1313: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1314: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1315: break;
1.270 dtucker 1316: if (errno != EAGAIN && errno != EINTR) {
1317: r = SSH_ERR_SYSTEM_ERROR;
1318: goto out;
1319: }
1.201 markus 1320: if (state->packet_timeout_ms == -1)
1.154 dtucker 1321: continue;
1322: ms_subtract_diff(&start, &ms_remain);
1323: if (ms_remain <= 0) {
1.201 markus 1324: r = 0;
1.154 dtucker 1325: break;
1326: }
1327: }
1.246 djm 1328: if (r == 0) {
1329: r = SSH_ERR_CONN_TIMEOUT;
1330: goto out;
1331: }
1.14 markus 1332: /* Read data from the socket. */
1.222 markus 1333: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1334: if (len == 0) {
1335: r = SSH_ERR_CONN_CLOSED;
1336: goto out;
1337: }
1.286 ! deraadt 1338: if (len == -1) {
1.210 markus 1339: r = SSH_ERR_SYSTEM_ERROR;
1340: goto out;
1341: }
1.204 djm 1342:
1.14 markus 1343: /* Append it to the buffer. */
1.204 djm 1344: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1345: goto out;
1.14 markus 1346: }
1.210 markus 1347: out:
1.201 markus 1348: free(setp);
1349: return r;
1.1 deraadt 1350: }
1351:
1.77 djm 1352: int
1.201 markus 1353: ssh_packet_read(struct ssh *ssh)
1.77 djm 1354: {
1.201 markus 1355: u_char type;
1356: int r;
1357:
1358: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1359: fatal("%s: %s", __func__, ssh_err(r));
1360: return type;
1.77 djm 1361: }
1362:
1.16 markus 1363: /*
1364: * Waits until a packet has been received, verifies that its type matches
1365: * that given, and gives a fatal error and exits if there is a mismatch.
1366: */
1.1 deraadt 1367:
1.205 djm 1368: int
1369: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1370: {
1.205 djm 1371: int r;
1372: u_char type;
1.1 deraadt 1373:
1.205 djm 1374: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1375: return r;
1376: if (type != expected_type) {
1377: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1378: "Protocol error: expected packet type %d, got %d",
1.205 djm 1379: expected_type, type)) != 0)
1380: return r;
1381: return SSH_ERR_PROTOCOL_ERROR;
1382: }
1383: return 0;
1.1 deraadt 1384: }
1.14 markus 1385:
1.242 markus 1386: static int
1387: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1388: {
1389: struct session_state *state = ssh->state;
1390: const u_char *cp;
1391: size_t need;
1392: int r;
1393:
1394: if (ssh->kex)
1395: return SSH_ERR_INTERNAL_ERROR;
1396: *typep = SSH_MSG_NONE;
1397: cp = sshbuf_ptr(state->input);
1398: if (state->packlen == 0) {
1399: if (sshbuf_len(state->input) < 4 + 1)
1400: return 0; /* packet is incomplete */
1401: state->packlen = PEEK_U32(cp);
1402: if (state->packlen < 4 + 1 ||
1403: state->packlen > PACKET_MAX_SIZE)
1404: return SSH_ERR_MESSAGE_INCOMPLETE;
1405: }
1406: need = state->packlen + 4;
1407: if (sshbuf_len(state->input) < need)
1408: return 0; /* packet is incomplete */
1409: sshbuf_reset(state->incoming_packet);
1410: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1411: state->packlen)) != 0 ||
1412: (r = sshbuf_consume(state->input, need)) != 0 ||
1413: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1414: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1415: return r;
1416: if (ssh_packet_log_type(*typep))
1417: debug3("%s: type %u", __func__, *typep);
1418: /* sshbuf_dump(state->incoming_packet, stderr); */
1419: /* reset for next packet */
1420: state->packlen = 0;
1421: return r;
1422: }
1423:
1.201 markus 1424: int
1425: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1426: {
1.201 markus 1427: struct session_state *state = ssh->state;
1.40 markus 1428: u_int padlen, need;
1.231 djm 1429: u_char *cp;
1.201 markus 1430: u_int maclen, aadlen = 0, authlen = 0, block_size;
1431: struct sshenc *enc = NULL;
1432: struct sshmac *mac = NULL;
1433: struct sshcomp *comp = NULL;
1.200 markus 1434: int r;
1.201 markus 1435:
1.242 markus 1436: if (state->mux)
1437: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1438:
1.201 markus 1439: *typep = SSH_MSG_NONE;
1440:
1441: if (state->packet_discard)
1442: return 0;
1443:
1444: if (state->newkeys[MODE_IN] != NULL) {
1445: enc = &state->newkeys[MODE_IN]->enc;
1446: mac = &state->newkeys[MODE_IN]->mac;
1447: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1448: /* disable mac for authenticated encryption */
1449: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1450: mac = NULL;
1.25 markus 1451: }
1452: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1453: block_size = enc ? enc->block_size : 8;
1.180 markus 1454: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1455:
1.201 markus 1456: if (aadlen && state->packlen == 0) {
1.235 djm 1457: if (cipher_get_length(state->receive_context,
1.201 markus 1458: &state->packlen, state->p_read.seqnr,
1459: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1460: return 0;
1461: if (state->packlen < 1 + 4 ||
1462: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1463: #ifdef PACKET_DEBUG
1.201 markus 1464: sshbuf_dump(state->input, stderr);
1.178 markus 1465: #endif
1.201 markus 1466: logit("Bad packet length %u.", state->packlen);
1467: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1468: return r;
1.217 djm 1469: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1470: }
1.201 markus 1471: sshbuf_reset(state->incoming_packet);
1472: } else if (state->packlen == 0) {
1.25 markus 1473: /*
1474: * check if input size is less than the cipher block size,
1475: * decrypt first block and extract length of incoming packet
1476: */
1.201 markus 1477: if (sshbuf_len(state->input) < block_size)
1478: return 0;
1479: sshbuf_reset(state->incoming_packet);
1480: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1481: &cp)) != 0)
1482: goto out;
1.235 djm 1483: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1484: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1485: block_size, 0, 0)) != 0)
1486: goto out;
1487: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1488: if (state->packlen < 1 + 4 ||
1489: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1490: #ifdef PACKET_DEBUG
1.201 markus 1491: fprintf(stderr, "input: \n");
1492: sshbuf_dump(state->input, stderr);
1493: fprintf(stderr, "incoming_packet: \n");
1494: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1495: #endif
1.201 markus 1496: logit("Bad packet length %u.", state->packlen);
1.234 markus 1497: return ssh_packet_start_discard(ssh, enc, mac, 0,
1498: PACKET_MAX_SIZE);
1.25 markus 1499: }
1.201 markus 1500: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1501: goto out;
1.25 markus 1502: }
1.201 markus 1503: DBG(debug("input: packet len %u", state->packlen+4));
1504:
1.178 markus 1505: if (aadlen) {
1506: /* only the payload is encrypted */
1.201 markus 1507: need = state->packlen;
1.178 markus 1508: } else {
1509: /*
1510: * the payload size and the payload are encrypted, but we
1511: * have a partial packet of block_size bytes
1512: */
1.201 markus 1513: need = 4 + state->packlen - block_size;
1.178 markus 1514: }
1.180 markus 1515: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1516: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1517: if (need % block_size != 0) {
1518: logit("padding error: need %d block %d mod %d",
1.25 markus 1519: need, block_size, need % block_size);
1.234 markus 1520: return ssh_packet_start_discard(ssh, enc, mac, 0,
1521: PACKET_MAX_SIZE - block_size);
1.158 markus 1522: }
1.25 markus 1523: /*
1524: * check if the entire packet has been received and
1.178 markus 1525: * decrypt into incoming_packet:
1526: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1527: * 'need' bytes are encrypted, followed by either
1528: * 'authlen' bytes of authentication tag or
1.178 markus 1529: * 'maclen' bytes of message authentication code.
1.25 markus 1530: */
1.201 markus 1531: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1532: return 0; /* packet is incomplete */
1.25 markus 1533: #ifdef PACKET_DEBUG
1534: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1535: sshbuf_dump(state->input, stderr);
1.25 markus 1536: #endif
1.231 djm 1537: /* EtM: check mac over encrypted input */
1.201 markus 1538: if (mac && mac->enabled && mac->etm) {
1.231 djm 1539: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1540: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1541: sshbuf_ptr(state->input) + aadlen + need + authlen,
1542: maclen)) != 0) {
1543: if (r == SSH_ERR_MAC_INVALID)
1544: logit("Corrupted MAC on input.");
1.201 markus 1545: goto out;
1.231 djm 1546: }
1.201 markus 1547: }
1548: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1549: &cp)) != 0)
1550: goto out;
1.235 djm 1551: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1552: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1553: goto out;
1554: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1555: goto out;
1.29 markus 1556: if (mac && mac->enabled) {
1.231 djm 1557: /* Not EtM: check MAC over cleartext */
1558: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1559: sshbuf_ptr(state->incoming_packet),
1560: sshbuf_len(state->incoming_packet),
1561: sshbuf_ptr(state->input), maclen)) != 0) {
1562: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1563: goto out;
1.159 markus 1564: logit("Corrupted MAC on input.");
1.247 markus 1565: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1566: return SSH_ERR_INTERNAL_ERROR;
1567: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1568: sshbuf_len(state->incoming_packet),
1.247 markus 1569: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1570: }
1.231 djm 1571: /* Remove MAC from input buffer */
1.201 markus 1572: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1573: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1574: goto out;
1.25 markus 1575: }
1.77 djm 1576: if (seqnr_p != NULL)
1.201 markus 1577: *seqnr_p = state->p_read.seqnr;
1578: if (++state->p_read.seqnr == 0)
1.106 itojun 1579: logit("incoming seqnr wraps around");
1.201 markus 1580: if (++state->p_read.packets == 0)
1581: if (!(ssh->compat & SSH_BUG_NOREKEY))
1582: return SSH_ERR_NEED_REKEY;
1583: state->p_read.blocks += (state->packlen + 4) / block_size;
1584: state->p_read.bytes += state->packlen + 4;
1.25 markus 1585:
1586: /* get padlen */
1.201 markus 1587: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1588: DBG(debug("input: padlen %d", padlen));
1.205 djm 1589: if (padlen < 4) {
1590: if ((r = sshpkt_disconnect(ssh,
1591: "Corrupted padlen %d on input.", padlen)) != 0 ||
1592: (r = ssh_packet_write_wait(ssh)) != 0)
1593: return r;
1594: return SSH_ERR_CONN_CORRUPT;
1595: }
1.25 markus 1596:
1597: /* skip packet size + padlen, discard padding */
1.201 markus 1598: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1599: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1600: goto out;
1.25 markus 1601:
1.201 markus 1602: DBG(debug("input: len before de-compress %zd",
1603: sshbuf_len(state->incoming_packet)));
1.25 markus 1604: if (comp && comp->enabled) {
1.201 markus 1605: sshbuf_reset(state->compression_buffer);
1606: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1607: state->compression_buffer)) != 0)
1608: goto out;
1609: sshbuf_reset(state->incoming_packet);
1610: if ((r = sshbuf_putb(state->incoming_packet,
1611: state->compression_buffer)) != 0)
1612: goto out;
1613: DBG(debug("input: len after de-compress %zd",
1614: sshbuf_len(state->incoming_packet)));
1.25 markus 1615: }
1616: /*
1617: * get packet type, implies consume.
1618: * return length of payload (without type field)
1619: */
1.201 markus 1620: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1621: goto out;
1.226 djm 1622: if (ssh_packet_log_type(*typep))
1623: debug3("receive packet: type %u", *typep);
1.205 djm 1624: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1625: if ((r = sshpkt_disconnect(ssh,
1626: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1627: (r = ssh_packet_write_wait(ssh)) != 0)
1628: return r;
1629: return SSH_ERR_PROTOCOL_ERROR;
1630: }
1.243 djm 1631: if (state->hook_in != NULL &&
1632: (r = state->hook_in(ssh, state->incoming_packet, typep,
1633: state->hook_in_ctx)) != 0)
1634: return r;
1.238 markus 1635: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1636: r = ssh_packet_enable_delayed_compress(ssh);
1637: else
1638: r = 0;
1.25 markus 1639: #ifdef PACKET_DEBUG
1.201 markus 1640: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1641: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1642: #endif
1.62 markus 1643: /* reset for next packet */
1.201 markus 1644: state->packlen = 0;
1.228 djm 1645:
1646: /* do we need to rekey? */
1647: if (ssh_packet_need_rekeying(ssh, 0)) {
1648: debug3("%s: rekex triggered", __func__);
1649: if ((r = kex_start_rekex(ssh)) != 0)
1650: return r;
1651: }
1.201 markus 1652: out:
1653: return r;
1.25 markus 1654: }
1655:
1656: int
1.201 markus 1657: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1658: {
1.201 markus 1659: struct session_state *state = ssh->state;
1.96 deraadt 1660: u_int reason, seqnr;
1.201 markus 1661: int r;
1662: u_char *msg;
1.62 markus 1663:
1.25 markus 1664: for (;;) {
1.201 markus 1665: msg = NULL;
1.249 djm 1666: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1667: if (r != 0)
1668: return r;
1669: if (*typep) {
1670: state->keep_alive_timeouts = 0;
1671: DBG(debug("received packet type %d", *typep));
1672: }
1673: switch (*typep) {
1674: case SSH2_MSG_IGNORE:
1675: debug3("Received SSH2_MSG_IGNORE");
1676: break;
1677: case SSH2_MSG_DEBUG:
1678: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1679: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1680: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1681: free(msg);
1.201 markus 1682: return r;
1.48 stevesk 1683: }
1.249 djm 1684: debug("Remote: %.900s", msg);
1685: free(msg);
1686: break;
1687: case SSH2_MSG_DISCONNECT:
1688: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1689: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1690: return r;
1691: /* Ignore normal client exit notifications */
1692: do_log2(ssh->state->server_side &&
1693: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1694: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1695: "Received disconnect from %s port %d:"
1696: "%u: %.400s", ssh_remote_ipaddr(ssh),
1697: ssh_remote_port(ssh), reason, msg);
1698: free(msg);
1699: return SSH_ERR_DISCONNECTED;
1700: case SSH2_MSG_UNIMPLEMENTED:
1701: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1702: return r;
1703: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1704: seqnr);
1705: break;
1706: default:
1707: return 0;
1.25 markus 1708: }
1709: }
1710: }
1711:
1.16 markus 1712: /*
1713: * Buffers the given amount of input characters. This is intended to be used
1714: * together with packet_read_poll.
1715: */
1.1 deraadt 1716:
1.204 djm 1717: int
1.201 markus 1718: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1719: {
1.201 markus 1720: struct session_state *state = ssh->state;
1721: int r;
1722:
1723: if (state->packet_discard) {
1724: state->keep_alive_timeouts = 0; /* ?? */
1725: if (len >= state->packet_discard) {
1726: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1727: return r;
1.201 markus 1728: }
1729: state->packet_discard -= len;
1.204 djm 1730: return 0;
1.159 markus 1731: }
1.201 markus 1732: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1733: return r;
1734:
1735: return 0;
1.28 markus 1736: }
1737:
1738: int
1.201 markus 1739: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1740: {
1.201 markus 1741: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1742: }
1743:
1.16 markus 1744: /*
1745: * Sends a diagnostic message from the server to the client. This message
1746: * can be sent at any time (but not while constructing another message). The
1747: * message is printed immediately, but only if the client is being executed
1748: * in verbose mode. These messages are primarily intended to ease debugging
1749: * authentication problems. The length of the formatted message must not
1.205 djm 1750: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1751: */
1.2 provos 1752: void
1.201 markus 1753: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1754: {
1.14 markus 1755: char buf[1024];
1756: va_list args;
1.201 markus 1757: int r;
1.39 markus 1758:
1.249 djm 1759: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1760: return;
1.14 markus 1761:
1762: va_start(args, fmt);
1763: vsnprintf(buf, sizeof(buf), fmt, args);
1764: va_end(args);
1.265 djm 1765:
1766: debug3("sending debug message: %s", buf);
1.14 markus 1767:
1.249 djm 1768: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1769: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1770: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1771: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1772: (r = sshpkt_send(ssh)) != 0 ||
1773: (r = ssh_packet_write_wait(ssh)) != 0)
1.205 djm 1774: fatal("%s: %s", __func__, ssh_err(r));
1775: }
1776:
1.268 dtucker 1777: void
1778: sshpkt_fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1.245 djm 1779: {
1780: snprintf(s, l, "%.200s%s%s port %d",
1781: ssh->log_preamble ? ssh->log_preamble : "",
1782: ssh->log_preamble ? " " : "",
1783: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1784: }
1785:
1.205 djm 1786: /*
1787: * Pretty-print connection-terminating errors and exit.
1788: */
1.280 djm 1789: static void
1790: sshpkt_vfatal(struct ssh *ssh, int r, const char *fmt, va_list ap)
1.205 djm 1791: {
1.280 djm 1792: char *tag = NULL, remote_id[512];
1.245 djm 1793:
1.268 dtucker 1794: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.245 djm 1795:
1.205 djm 1796: switch (r) {
1797: case SSH_ERR_CONN_CLOSED:
1.257 markus 1798: ssh_packet_clear_keys(ssh);
1.245 djm 1799: logdie("Connection closed by %s", remote_id);
1.205 djm 1800: case SSH_ERR_CONN_TIMEOUT:
1.257 markus 1801: ssh_packet_clear_keys(ssh);
1.245 djm 1802: logdie("Connection %s %s timed out",
1803: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1804: case SSH_ERR_DISCONNECTED:
1.257 markus 1805: ssh_packet_clear_keys(ssh);
1.245 djm 1806: logdie("Disconnected from %s", remote_id);
1.212 djm 1807: case SSH_ERR_SYSTEM_ERROR:
1.257 markus 1808: if (errno == ECONNRESET) {
1809: ssh_packet_clear_keys(ssh);
1.245 djm 1810: logdie("Connection reset by %s", remote_id);
1.257 markus 1811: }
1.213 djm 1812: /* FALLTHROUGH */
1813: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1814: case SSH_ERR_NO_MAC_ALG_MATCH:
1815: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1816: case SSH_ERR_NO_KEX_ALG_MATCH:
1817: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1818: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.257 markus 1819: ssh_packet_clear_keys(ssh);
1.245 djm 1820: logdie("Unable to negotiate with %s: %s. "
1821: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1822: ssh->kex->failed_choice);
1.212 djm 1823: }
1824: /* FALLTHROUGH */
1.205 djm 1825: default:
1.280 djm 1826: if (vasprintf(&tag, fmt, ap) == -1) {
1827: ssh_packet_clear_keys(ssh);
1828: logdie("%s: could not allocate failure message",
1829: __func__);
1830: }
1.257 markus 1831: ssh_packet_clear_keys(ssh);
1.245 djm 1832: logdie("%s%sConnection %s %s: %s",
1.205 djm 1833: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 1834: ssh->state->server_side ? "from" : "to",
1.245 djm 1835: remote_id, ssh_err(r));
1.205 djm 1836: }
1.1 deraadt 1837: }
1838:
1.280 djm 1839: void
1840: sshpkt_fatal(struct ssh *ssh, int r, const char *fmt, ...)
1841: {
1842: va_list ap;
1843:
1844: va_start(ap, fmt);
1845: sshpkt_vfatal(ssh, r, fmt, ap);
1846: /* NOTREACHED */
1847: va_end(ap);
1848: logdie("%s: should have exited", __func__);
1849: }
1850:
1.16 markus 1851: /*
1852: * Logs the error plus constructs and sends a disconnect packet, closes the
1853: * connection, and exits. This function never returns. The error message
1854: * should not contain a newline. The length of the formatted message must
1855: * not exceed 1024 bytes.
1856: */
1.2 provos 1857: void
1.201 markus 1858: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1859: {
1.245 djm 1860: char buf[1024], remote_id[512];
1.14 markus 1861: va_list args;
1862: static int disconnecting = 0;
1.201 markus 1863: int r;
1.97 deraadt 1864:
1.14 markus 1865: if (disconnecting) /* Guard against recursive invocations. */
1866: fatal("packet_disconnect called recursively.");
1867: disconnecting = 1;
1868:
1.16 markus 1869: /*
1870: * Format the message. Note that the caller must make sure the
1871: * message is of limited size.
1872: */
1.268 dtucker 1873: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1874: va_start(args, fmt);
1875: vsnprintf(buf, sizeof(buf), fmt, args);
1876: va_end(args);
1877:
1.99 markus 1878: /* Display the error locally */
1.245 djm 1879: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1880:
1.205 djm 1881: /*
1882: * Send the disconnect message to the other side, and wait
1883: * for it to get sent.
1884: */
1885: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1.280 djm 1886: sshpkt_fatal(ssh, r, "%s", __func__);
1.205 djm 1887:
1888: if ((r = ssh_packet_write_wait(ssh)) != 0)
1.280 djm 1889: sshpkt_fatal(ssh, r, "%s", __func__);
1.14 markus 1890:
1891: /* Close the connection. */
1.201 markus 1892: ssh_packet_close(ssh);
1.112 markus 1893: cleanup_exit(255);
1.1 deraadt 1894: }
1895:
1.205 djm 1896: /*
1897: * Checks if there is any buffered output, and tries to write some of
1898: * the output.
1899: */
1900: int
1.201 markus 1901: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1902: {
1.201 markus 1903: struct session_state *state = ssh->state;
1904: int len = sshbuf_len(state->output);
1.222 markus 1905: int r;
1.97 deraadt 1906:
1.14 markus 1907: if (len > 0) {
1.222 markus 1908: len = write(state->connection_out,
1909: sshbuf_ptr(state->output), len);
1.156 djm 1910: if (len == -1) {
1911: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1912: return 0;
1913: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1914: }
1.222 markus 1915: if (len == 0)
1.205 djm 1916: return SSH_ERR_CONN_CLOSED;
1.201 markus 1917: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1918: return r;
1.14 markus 1919: }
1.205 djm 1920: return 0;
1.1 deraadt 1921: }
1922:
1.16 markus 1923: /*
1924: * Calls packet_write_poll repeatedly until all pending output data has been
1925: * written.
1926: */
1.205 djm 1927: int
1.201 markus 1928: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1929: {
1.56 millert 1930: fd_set *setp;
1.205 djm 1931: int ret, r, ms_remain = 0;
1.154 dtucker 1932: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1933: struct session_state *state = ssh->state;
1.56 millert 1934:
1.214 deraadt 1935: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1936: NFDBITS), sizeof(fd_mask));
1.201 markus 1937: if (setp == NULL)
1.205 djm 1938: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1939: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1940: free(setp);
1.215 djm 1941: return r;
1.216 gsoares 1942: }
1.201 markus 1943: while (ssh_packet_have_data_to_write(ssh)) {
1944: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1945: NFDBITS) * sizeof(fd_mask));
1.201 markus 1946: FD_SET(state->connection_out, setp);
1.154 dtucker 1947:
1.201 markus 1948: if (state->packet_timeout_ms > 0) {
1949: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1950: timeoutp = &timeout;
1951: }
1952: for (;;) {
1.201 markus 1953: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1954: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1955: monotime_tv(&start);
1.154 dtucker 1956: }
1.201 markus 1957: if ((ret = select(state->connection_out + 1,
1.161 andreas 1958: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1959: break;
1.161 andreas 1960: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1961: break;
1.201 markus 1962: if (state->packet_timeout_ms == -1)
1.154 dtucker 1963: continue;
1964: ms_subtract_diff(&start, &ms_remain);
1965: if (ms_remain <= 0) {
1966: ret = 0;
1967: break;
1968: }
1969: }
1970: if (ret == 0) {
1.205 djm 1971: free(setp);
1972: return SSH_ERR_CONN_TIMEOUT;
1973: }
1974: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1975: free(setp);
1976: return r;
1.154 dtucker 1977: }
1.14 markus 1978: }
1.186 djm 1979: free(setp);
1.205 djm 1980: return 0;
1.1 deraadt 1981: }
1982:
1983: /* Returns true if there is buffered data to write to the connection. */
1984:
1.2 provos 1985: int
1.201 markus 1986: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 1987: {
1.201 markus 1988: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 1989: }
1990:
1991: /* Returns true if there is not too much data to write to the connection. */
1992:
1.2 provos 1993: int
1.201 markus 1994: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 1995: {
1.201 markus 1996: if (ssh->state->interactive_mode)
1997: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 1998: else
1.201 markus 1999: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 2000: }
2001:
1.201 markus 2002: void
2003: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 2004: {
1.263 djm 2005: if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
1.101 markus 2006: return;
1.201 markus 2007: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 2008: case AF_INET:
2009: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 2010: if (setsockopt(ssh->state->connection_in,
1.286 ! deraadt 2011: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) == -1)
1.173 djm 2012: error("setsockopt IP_TOS %d: %.100s:",
2013: tos, strerror(errno));
2014: break;
2015: case AF_INET6:
2016: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 2017: if (setsockopt(ssh->state->connection_in,
1.286 ! deraadt 2018: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) == -1)
1.173 djm 2019: error("setsockopt IPV6_TCLASS %d: %.100s:",
2020: tos, strerror(errno));
2021: break;
2022: }
1.101 markus 2023: }
2024:
1.1 deraadt 2025: /* Informs that the current session is interactive. Sets IP flags for that. */
2026:
1.2 provos 2027: void
1.201 markus 2028: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2029: {
1.201 markus 2030: struct session_state *state = ssh->state;
2031:
2032: if (state->set_interactive_called)
1.43 markus 2033: return;
1.201 markus 2034: state->set_interactive_called = 1;
1.1 deraadt 2035:
1.14 markus 2036: /* Record that we are in interactive mode. */
1.201 markus 2037: state->interactive_mode = interactive;
1.1 deraadt 2038:
1.19 markus 2039: /* Only set socket options if using a socket. */
1.201 markus 2040: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2041: return;
1.201 markus 2042: set_nodelay(state->connection_in);
2043: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2044: qos_bulk);
1.1 deraadt 2045: }
2046:
2047: /* Returns true if the current connection is interactive. */
2048:
1.2 provos 2049: int
1.201 markus 2050: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2051: {
1.201 markus 2052: return ssh->state->interactive_mode;
1.12 markus 2053: }
2054:
1.113 deraadt 2055: int
1.201 markus 2056: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2057: {
1.201 markus 2058: struct session_state *state = ssh->state;
2059:
2060: if (state->set_maxsize_called) {
1.106 itojun 2061: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2062: state->max_packet_size, s);
1.14 markus 2063: return -1;
2064: }
2065: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2066: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2067: return -1;
2068: }
1.201 markus 2069: state->set_maxsize_called = 1;
1.66 markus 2070: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2071: state->max_packet_size = s;
1.14 markus 2072: return s;
1.53 markus 2073: }
2074:
1.161 andreas 2075: int
1.201 markus 2076: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2077: {
1.201 markus 2078: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2079: }
2080:
2081: void
1.201 markus 2082: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2083: {
1.201 markus 2084: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2085: }
2086:
2087: u_int
1.201 markus 2088: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2089: {
1.201 markus 2090: return ssh->state->max_packet_size;
1.71 markus 2091: }
2092:
1.105 markus 2093: void
1.244 dtucker 2094: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2095: {
1.244 dtucker 2096: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2097: (unsigned int)seconds);
1.201 markus 2098: ssh->state->rekey_limit = bytes;
2099: ssh->state->rekey_interval = seconds;
1.184 dtucker 2100: }
2101:
2102: time_t
1.201 markus 2103: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2104: {
2105: time_t seconds;
2106:
1.201 markus 2107: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2108: monotime();
1.185 dtucker 2109: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2110: }
2111:
2112: void
1.201 markus 2113: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2114: {
1.201 markus 2115: ssh->state->server_side = 1;
1.278 djm 2116: ssh->kex->server = 1; /* XXX unify? */
1.118 markus 2117: }
2118:
2119: void
1.201 markus 2120: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2121: {
1.201 markus 2122: ssh->state->after_authentication = 1;
1.161 andreas 2123: }
2124:
2125: void *
1.201 markus 2126: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2127: {
1.201 markus 2128: return (void *)ssh->state->input;
1.161 andreas 2129: }
2130:
2131: void *
1.201 markus 2132: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2133: {
1.201 markus 2134: return (void *)ssh->state->output;
1.166 andreas 2135: }
2136:
1.196 markus 2137: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2138: static int
2139: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2140: {
1.239 djm 2141: int r;
1.196 markus 2142:
2143: debug("%s: called", __func__);
2144: /* This was set in net child, but is not visible in user child */
1.201 markus 2145: ssh->state->after_authentication = 1;
2146: ssh->state->rekeying = 0;
1.239 djm 2147: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2148: return r;
1.201 markus 2149: return 0;
2150: }
2151:
2152: /* Packet state (de-)serialization for privsep */
2153:
2154: /* turn kex into a blob for packet state serialization */
2155: static int
2156: kex_to_blob(struct sshbuf *m, struct kex *kex)
2157: {
2158: int r;
2159:
2160: if ((r = sshbuf_put_string(m, kex->session_id,
2161: kex->session_id_len)) != 0 ||
2162: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
1.269 djm 2163: (r = sshbuf_put_cstring(m, kex->hostkey_alg)) != 0 ||
1.201 markus 2164: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
1.269 djm 2165: (r = sshbuf_put_u32(m, kex->hostkey_nid)) != 0 ||
1.201 markus 2166: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2167: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2168: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
1.278 djm 2169: (r = sshbuf_put_stringb(m, kex->client_version)) != 0 ||
2170: (r = sshbuf_put_stringb(m, kex->server_version)) != 0 ||
2171: (r = sshbuf_put_u32(m, kex->flags)) != 0)
1.201 markus 2172: return r;
2173: return 0;
2174: }
2175:
2176: /* turn key exchange results into a blob for packet state serialization */
2177: static int
2178: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2179: {
2180: struct sshbuf *b;
2181: struct sshcipher_ctx *cc;
2182: struct sshcomp *comp;
2183: struct sshenc *enc;
2184: struct sshmac *mac;
2185: struct newkeys *newkey;
2186: int r;
2187:
2188: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2189: return SSH_ERR_INTERNAL_ERROR;
2190: enc = &newkey->enc;
2191: mac = &newkey->mac;
2192: comp = &newkey->comp;
1.235 djm 2193: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2194: ssh->state->receive_context;
1.201 markus 2195: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2196: return r;
2197: if ((b = sshbuf_new()) == NULL)
2198: return SSH_ERR_ALLOC_FAIL;
2199: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2200: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2201: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2202: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2203: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2204: goto out;
2205: if (cipher_authlen(enc->cipher) == 0) {
2206: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2207: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2208: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2209: goto out;
2210: }
2211: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2212: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2213: goto out;
2214: r = sshbuf_put_stringb(m, b);
2215: out:
1.221 mmcc 2216: sshbuf_free(b);
1.201 markus 2217: return r;
2218: }
2219:
2220: /* serialize packet state into a blob */
2221: int
2222: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2223: {
2224: struct session_state *state = ssh->state;
1.249 djm 2225: int r;
1.201 markus 2226:
1.249 djm 2227: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2228: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2229: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2230: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2231: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2232: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2233: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2234: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2235: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2236: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2237: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2238: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2239: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2240: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2241: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 2242: return r;
1.201 markus 2243:
2244: return 0;
2245: }
2246:
2247: /* restore key exchange results from blob for packet state de-serialization */
2248: static int
2249: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2250: {
2251: struct sshbuf *b = NULL;
2252: struct sshcomp *comp;
2253: struct sshenc *enc;
2254: struct sshmac *mac;
2255: struct newkeys *newkey = NULL;
2256: size_t keylen, ivlen, maclen;
2257: int r;
2258:
2259: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2260: r = SSH_ERR_ALLOC_FAIL;
2261: goto out;
2262: }
2263: if ((r = sshbuf_froms(m, &b)) != 0)
2264: goto out;
2265: #ifdef DEBUG_PK
2266: sshbuf_dump(b, stderr);
2267: #endif
2268: enc = &newkey->enc;
2269: mac = &newkey->mac;
2270: comp = &newkey->comp;
2271:
2272: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2273: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2274: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2275: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2276: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2277: goto out;
1.262 djm 2278: if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2279: r = SSH_ERR_INVALID_FORMAT;
2280: goto out;
2281: }
1.201 markus 2282: if (cipher_authlen(enc->cipher) == 0) {
2283: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2284: goto out;
2285: if ((r = mac_setup(mac, mac->name)) != 0)
2286: goto out;
2287: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2288: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2289: goto out;
2290: if (maclen > mac->key_len) {
2291: r = SSH_ERR_INVALID_FORMAT;
2292: goto out;
2293: }
2294: mac->key_len = maclen;
2295: }
2296: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2297: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2298: goto out;
2299: if (sshbuf_len(b) != 0) {
2300: r = SSH_ERR_INVALID_FORMAT;
2301: goto out;
2302: }
2303: enc->key_len = keylen;
2304: enc->iv_len = ivlen;
2305: ssh->kex->newkeys[mode] = newkey;
2306: newkey = NULL;
2307: r = 0;
2308: out:
1.219 mmcc 2309: free(newkey);
1.221 mmcc 2310: sshbuf_free(b);
1.201 markus 2311: return r;
2312: }
2313:
2314: /* restore kex from blob for packet state de-serialization */
2315: static int
2316: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2317: {
2318: struct kex *kex;
2319: int r;
2320:
1.278 djm 2321: if ((kex = kex_new()) == NULL)
2322: return SSH_ERR_ALLOC_FAIL;
1.201 markus 2323: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2324: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
1.269 djm 2325: (r = sshbuf_get_cstring(m, &kex->hostkey_alg, NULL)) != 0 ||
1.201 markus 2326: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
1.269 djm 2327: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_nid)) != 0 ||
1.201 markus 2328: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2329: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2330: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
1.278 djm 2331: (r = sshbuf_get_stringb(m, kex->client_version)) != 0 ||
2332: (r = sshbuf_get_stringb(m, kex->server_version)) != 0 ||
2333: (r = sshbuf_get_u32(m, &kex->flags)) != 0)
1.201 markus 2334: goto out;
2335: kex->server = 1;
2336: kex->done = 1;
2337: r = 0;
2338: out:
2339: if (r != 0 || kexp == NULL) {
1.278 djm 2340: kex_free(kex);
1.201 markus 2341: if (kexp != NULL)
2342: *kexp = NULL;
2343: } else {
1.278 djm 2344: kex_free(*kexp);
1.201 markus 2345: *kexp = kex;
2346: }
2347: return r;
2348: }
2349:
2350: /*
2351: * Restore packet state from content of blob 'm' (de-serialization).
2352: * Note that 'm' will be partially consumed on parsing or any other errors.
2353: */
2354: int
2355: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2356: {
2357: struct session_state *state = ssh->state;
1.254 djm 2358: const u_char *input, *output;
2359: size_t ilen, olen;
1.201 markus 2360: int r;
2361:
1.249 djm 2362: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2363: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2364: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2365: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2366: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2367: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2368: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2369: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2370: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2371: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2372: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2373: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2374: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2375: return r;
2376: /*
2377: * We set the time here so that in post-auth privsep slave we
2378: * count from the completion of the authentication.
2379: */
2380: state->rekey_time = monotime();
2381: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2382: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2383: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2384: return r;
1.201 markus 2385:
1.239 djm 2386: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2387: return r;
2388:
2389: sshbuf_reset(state->input);
2390: sshbuf_reset(state->output);
2391: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2392: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2393: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2394: (r = sshbuf_put(state->output, output, olen)) != 0)
2395: return r;
2396:
2397: if (sshbuf_len(m))
2398: return SSH_ERR_INVALID_FORMAT;
2399: debug3("%s: done", __func__);
2400: return 0;
2401: }
2402:
2403: /* NEW API */
2404:
2405: /* put data to the outgoing packet */
2406:
2407: int
2408: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2409: {
2410: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2411: }
2412:
2413: int
2414: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2415: {
2416: return sshbuf_putb(ssh->state->outgoing_packet, b);
2417: }
2418:
2419: int
2420: sshpkt_put_u8(struct ssh *ssh, u_char val)
2421: {
2422: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2423: }
2424:
2425: int
2426: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2427: {
2428: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2429: }
2430:
2431: int
2432: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2433: {
2434: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2435: }
2436:
2437: int
2438: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2439: {
2440: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2441: }
2442:
2443: int
2444: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2445: {
2446: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2447: }
2448:
2449: int
2450: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2451: {
2452: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2453: }
2454:
1.211 djm 2455: #ifdef WITH_OPENSSL
1.201 markus 2456: int
2457: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2458: {
2459: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2460: }
2461:
2462:
2463: int
2464: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2465: {
2466: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2467: }
1.211 djm 2468: #endif /* WITH_OPENSSL */
1.201 markus 2469:
2470: /* fetch data from the incoming packet */
2471:
2472: int
2473: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2474: {
2475: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2476: }
2477:
2478: int
2479: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2480: {
2481: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2482: }
2483:
2484: int
2485: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2486: {
2487: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2488: }
2489:
2490: int
2491: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2492: {
2493: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2494: }
2495:
2496: int
2497: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2498: {
2499: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2500: }
2501:
2502: int
2503: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2504: {
2505: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2506: }
2507:
2508: int
1.264 djm 2509: sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2510: {
2511: return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2512: }
2513:
2514: int
1.201 markus 2515: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2516: {
2517: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
1.282 djm 2518: }
2519:
2520: int
2521: sshpkt_getb_froms(struct ssh *ssh, struct sshbuf **valp)
2522: {
2523: return sshbuf_froms(ssh->state->incoming_packet, valp);
1.201 markus 2524: }
2525:
1.211 djm 2526: #ifdef WITH_OPENSSL
1.201 markus 2527: int
2528: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2529: {
2530: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2531: }
2532:
2533: int
1.281 djm 2534: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM **valp)
1.201 markus 2535: {
1.281 djm 2536: return sshbuf_get_bignum2(ssh->state->incoming_packet, valp);
1.201 markus 2537: }
1.211 djm 2538: #endif /* WITH_OPENSSL */
1.201 markus 2539:
2540: int
2541: sshpkt_get_end(struct ssh *ssh)
2542: {
2543: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2544: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2545: return 0;
2546: }
2547:
2548: const u_char *
2549: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2550: {
2551: if (lenp != NULL)
2552: *lenp = sshbuf_len(ssh->state->incoming_packet);
2553: return sshbuf_ptr(ssh->state->incoming_packet);
2554: }
2555:
2556: /* start a new packet */
2557:
2558: int
2559: sshpkt_start(struct ssh *ssh, u_char type)
2560: {
1.249 djm 2561: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2562:
2563: DBG(debug("packet_start[%d]", type));
1.249 djm 2564: memset(buf, 0, sizeof(buf));
2565: buf[sizeof(buf) - 1] = type;
1.201 markus 2566: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2567: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2568: }
2569:
1.242 markus 2570: static int
2571: ssh_packet_send_mux(struct ssh *ssh)
2572: {
2573: struct session_state *state = ssh->state;
2574: u_char type, *cp;
2575: size_t len;
2576: int r;
2577:
2578: if (ssh->kex)
2579: return SSH_ERR_INTERNAL_ERROR;
2580: len = sshbuf_len(state->outgoing_packet);
2581: if (len < 6)
2582: return SSH_ERR_INTERNAL_ERROR;
2583: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2584: type = cp[5];
2585: if (ssh_packet_log_type(type))
2586: debug3("%s: type %u", __func__, type);
2587: /* drop everything, but the connection protocol */
2588: if (type >= SSH2_MSG_CONNECTION_MIN &&
2589: type <= SSH2_MSG_CONNECTION_MAX) {
2590: POKE_U32(cp, len - 4);
2591: if ((r = sshbuf_putb(state->output,
2592: state->outgoing_packet)) != 0)
2593: return r;
2594: /* sshbuf_dump(state->output, stderr); */
2595: }
2596: sshbuf_reset(state->outgoing_packet);
1.264 djm 2597: return 0;
2598: }
2599:
2600: /*
2601: * 9.2. Ignored Data Message
2602: *
2603: * byte SSH_MSG_IGNORE
2604: * string data
2605: *
2606: * All implementations MUST understand (and ignore) this message at any
2607: * time (after receiving the protocol version). No implementation is
2608: * required to send them. This message can be used as an additional
2609: * protection measure against advanced traffic analysis techniques.
2610: */
2611: int
2612: sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2613: {
2614: u_int32_t rnd = 0;
2615: int r;
2616: u_int i;
2617:
2618: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2619: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2620: return r;
2621: for (i = 0; i < nbytes; i++) {
2622: if (i % 4 == 0)
2623: rnd = arc4random();
2624: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2625: return r;
2626: rnd >>= 8;
2627: }
1.242 markus 2628: return 0;
2629: }
2630:
1.201 markus 2631: /* send it */
2632:
2633: int
2634: sshpkt_send(struct ssh *ssh)
2635: {
1.242 markus 2636: if (ssh->state && ssh->state->mux)
2637: return ssh_packet_send_mux(ssh);
1.249 djm 2638: return ssh_packet_send2(ssh);
1.201 markus 2639: }
2640:
2641: int
2642: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2643: {
2644: char buf[1024];
2645: va_list args;
2646: int r;
2647:
2648: va_start(args, fmt);
2649: vsnprintf(buf, sizeof(buf), fmt, args);
2650: va_end(args);
2651:
1.249 djm 2652: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2653: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2654: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2655: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2656: (r = sshpkt_send(ssh)) != 0)
2657: return r;
1.201 markus 2658: return 0;
2659: }
2660:
2661: /* roundup current message to pad bytes */
2662: int
2663: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2664: {
2665: ssh->state->extra_pad = pad;
2666: return 0;
1.1 deraadt 2667: }
![[BACK]](/icons/back.gif){kind=icon}
Return to packet.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh