Annotation of src/usr.bin/ssh/packet.c, Revision 1.277
1.277 ! djm 1: /* $OpenBSD: packet.c,v 1.276 2018/07/09 21:03:30 markus Exp $ */
1.1 deraadt 2: /*
1.15 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.35 deraadt 6: * This file contains code implementing the packet protocol and communication
7: * with the other side. This same code is used both on client and server side.
1.29 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
1.29 markus 14: *
1.25 markus 15: *
16: * SSH2 packet format added by Markus Friedl.
1.69 markus 17: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.25 markus 18: *
1.35 deraadt 19: * Redistribution and use in source and binary forms, with or without
20: * modification, are permitted provided that the following conditions
21: * are met:
22: * 1. Redistributions of source code must retain the above copyright
23: * notice, this list of conditions and the following disclaimer.
24: * 2. Redistributions in binary form must reproduce the above copyright
25: * notice, this list of conditions and the following disclaimer in the
26: * documentation and/or other materials provided with the distribution.
27: *
28: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15 deraadt 38: */
1.1 deraadt 39:
1.142 deraadt 40: #include <sys/types.h>
1.105 markus 41: #include <sys/queue.h>
1.132 stevesk 42: #include <sys/socket.h>
1.138 stevesk 43: #include <sys/time.h>
1.132 stevesk 44: #include <netinet/in.h>
1.121 stevesk 45: #include <netinet/ip.h>
1.134 stevesk 46:
1.135 stevesk 47: #include <errno.h>
1.230 djm 48: #include <netdb.h>
1.134 stevesk 49: #include <stdarg.h>
1.141 stevesk 50: #include <stdio.h>
1.140 stevesk 51: #include <stdlib.h>
1.137 stevesk 52: #include <string.h>
1.136 stevesk 53: #include <unistd.h>
1.203 deraadt 54: #include <limits.h>
1.142 deraadt 55: #include <signal.h>
1.184 dtucker 56: #include <time.h>
1.1 deraadt 57:
1.201 markus 58: #include <zlib.h>
59:
1.1 deraadt 60: #include "xmalloc.h"
61: #include "crc32.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 ||
213: (state->input = sshbuf_new()) == NULL ||
214: (state->output = sshbuf_new()) == NULL ||
215: (state->outgoing_packet = sshbuf_new()) == NULL ||
216: (state->incoming_packet = sshbuf_new()) == NULL)
217: goto fail;
218: TAILQ_INIT(&state->outgoing);
1.202 markus 219: TAILQ_INIT(&ssh->private_keys);
220: TAILQ_INIT(&ssh->public_keys);
1.201 markus 221: state->connection_in = -1;
222: state->connection_out = -1;
223: state->max_packet_size = 32768;
224: state->packet_timeout_ms = -1;
225: state->p_send.packets = state->p_read.packets = 0;
226: state->initialized = 1;
227: /*
228: * ssh_packet_send2() needs to queue packets until
229: * we've done the initial key exchange.
230: */
231: state->rekeying = 1;
232: ssh->state = state;
233: return ssh;
234: fail:
235: if (state) {
236: sshbuf_free(state->input);
237: sshbuf_free(state->output);
238: sshbuf_free(state->incoming_packet);
239: sshbuf_free(state->outgoing_packet);
240: free(state);
241: }
242: free(ssh);
243: return NULL;
1.161 andreas 244: }
1.105 markus 245:
1.243 djm 246: void
247: ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
248: {
249: ssh->state->hook_in = hook;
250: ssh->state->hook_in_ctx = ctx;
251: }
252:
1.228 djm 253: /* Returns nonzero if rekeying is in progress */
254: int
255: ssh_packet_is_rekeying(struct ssh *ssh)
256: {
1.249 djm 257: return ssh->state->rekeying ||
258: (ssh->kex != NULL && ssh->kex->done == 0);
1.228 djm 259: }
260:
1.16 markus 261: /*
1.253 naddy 262: * Sets the descriptors used for communication.
1.16 markus 263: */
1.201 markus 264: struct ssh *
265: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1 deraadt 266: {
1.201 markus 267: struct session_state *state;
268: const struct sshcipher *none = cipher_by_name("none");
1.197 djm 269: int r;
1.97 deraadt 270:
1.205 djm 271: if (none == NULL) {
272: error("%s: cannot load cipher 'none'", __func__);
273: return NULL;
274: }
1.201 markus 275: if (ssh == NULL)
276: ssh = ssh_alloc_session_state();
1.205 djm 277: if (ssh == NULL) {
278: error("%s: cound not allocate state", __func__);
279: return NULL;
280: }
1.201 markus 281: state = ssh->state;
282: state->connection_in = fd_in;
283: state->connection_out = fd_out;
284: if ((r = cipher_init(&state->send_context, none,
1.197 djm 285: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201 markus 286: (r = cipher_init(&state->receive_context, none,
1.205 djm 287: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
288: error("%s: cipher_init failed: %s", __func__, ssh_err(r));
1.230 djm 289: free(ssh); /* XXX need ssh_free_session_state? */
1.205 djm 290: return NULL;
291: }
1.201 markus 292: state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
1.207 djm 293: /*
294: * Cache the IP address of the remote connection for use in error
295: * messages that might be generated after the connection has closed.
296: */
297: (void)ssh_remote_ipaddr(ssh);
1.201 markus 298: return ssh;
1.1 deraadt 299: }
300:
1.154 dtucker 301: void
1.201 markus 302: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 303: {
1.201 markus 304: struct session_state *state = ssh->state;
305:
1.174 djm 306: if (timeout <= 0 || count <= 0) {
1.201 markus 307: state->packet_timeout_ms = -1;
1.154 dtucker 308: return;
309: }
310: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 311: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 312: else
1.201 markus 313: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 314: }
315:
1.242 markus 316: void
317: ssh_packet_set_mux(struct ssh *ssh)
318: {
319: ssh->state->mux = 1;
320: ssh->state->rekeying = 0;
321: }
322:
323: int
324: ssh_packet_get_mux(struct ssh *ssh)
325: {
326: return ssh->state->mux;
327: }
328:
1.201 markus 329: int
1.245 djm 330: ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
331: {
332: va_list args;
333: int r;
334:
335: free(ssh->log_preamble);
336: if (fmt == NULL)
337: ssh->log_preamble = NULL;
338: else {
339: va_start(args, fmt);
340: r = vasprintf(&ssh->log_preamble, fmt, args);
341: va_end(args);
342: if (r < 0 || ssh->log_preamble == NULL)
343: return SSH_ERR_ALLOC_FAIL;
344: }
345: return 0;
346: }
347:
348: int
1.201 markus 349: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 350: {
1.201 markus 351: struct session_state *state = ssh->state;
352: int r;
353:
354: if (state->packet_discard_mac) {
1.159 markus 355: char buf[1024];
1.234 markus 356: size_t dlen = PACKET_MAX_SIZE;
1.201 markus 357:
1.234 markus 358: if (dlen > state->packet_discard_mac_already)
359: dlen -= state->packet_discard_mac_already;
1.159 markus 360: memset(buf, 'a', sizeof(buf));
1.234 markus 361: while (sshbuf_len(state->incoming_packet) < dlen)
1.201 markus 362: if ((r = sshbuf_put(state->incoming_packet, buf,
363: sizeof(buf))) != 0)
364: return r;
365: (void) mac_compute(state->packet_discard_mac,
366: state->p_read.seqnr,
1.234 markus 367: sshbuf_ptr(state->incoming_packet), dlen,
1.201 markus 368: NULL, 0);
1.159 markus 369: }
1.220 djm 370: logit("Finished discarding for %.200s port %d",
371: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 372: return SSH_ERR_MAC_INVALID;
1.159 markus 373: }
374:
1.201 markus 375: static int
376: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
1.234 markus 377: struct sshmac *mac, size_t mac_already, u_int discard)
1.159 markus 378: {
1.201 markus 379: struct session_state *state = ssh->state;
380: int r;
381:
382: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
383: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
384: return r;
385: return SSH_ERR_MAC_INVALID;
386: }
1.234 markus 387: /*
388: * Record number of bytes over which the mac has already
389: * been computed in order to minimize timing attacks.
390: */
391: if (mac && mac->enabled) {
1.201 markus 392: state->packet_discard_mac = mac;
1.234 markus 393: state->packet_discard_mac_already = mac_already;
394: }
395: if (sshbuf_len(state->input) >= discard)
396: return ssh_packet_stop_discard(ssh);
1.201 markus 397: state->packet_discard = discard - sshbuf_len(state->input);
398: return 0;
1.159 markus 399: }
400:
1.19 markus 401: /* Returns 1 if remote host is connected via socket, 0 if not. */
402:
403: int
1.201 markus 404: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 405: {
1.271 djm 406: struct session_state *state;
1.19 markus 407: struct sockaddr_storage from, to;
408: socklen_t fromlen, tolen;
409:
1.271 djm 410: if (ssh == NULL || ssh->state == NULL)
411: return 0;
412:
413: state = ssh->state;
1.230 djm 414: if (state->connection_in == -1 || state->connection_out == -1)
415: return 0;
1.19 markus 416: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 417: if (state->connection_in == state->connection_out)
1.19 markus 418: return 1;
419: fromlen = sizeof(from);
420: memset(&from, 0, sizeof(from));
1.201 markus 421: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.161 andreas 422: &fromlen) < 0)
1.19 markus 423: return 0;
424: tolen = sizeof(to);
425: memset(&to, 0, sizeof(to));
1.201 markus 426: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.161 andreas 427: &tolen) < 0)
1.19 markus 428: return 0;
429: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
430: return 0;
431: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
432: return 0;
433: return 1;
434: }
435:
1.91 markus 436: void
1.201 markus 437: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 438: {
1.201 markus 439: if (ibytes)
440: *ibytes = ssh->state->p_read.bytes;
441: if (obytes)
442: *obytes = ssh->state->p_send.bytes;
1.91 markus 443: }
1.125 deraadt 444:
1.91 markus 445: int
1.201 markus 446: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 447: {
448: struct sockaddr_storage to;
1.21 deraadt 449: socklen_t tolen = sizeof(to);
1.19 markus 450:
451: memset(&to, 0, sizeof(to));
1.201 markus 452: if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
1.161 andreas 453: &tolen) < 0)
1.19 markus 454: return 0;
1.173 djm 455: return to.ss_family;
1.19 markus 456: }
457:
1.1 deraadt 458: /* Sets the connection into non-blocking mode. */
459:
1.2 provos 460: void
1.201 markus 461: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 462: {
1.14 markus 463: /* Set the socket into non-blocking mode. */
1.201 markus 464: set_nonblock(ssh->state->connection_in);
1.14 markus 465:
1.201 markus 466: if (ssh->state->connection_out != ssh->state->connection_in)
467: set_nonblock(ssh->state->connection_out);
1.1 deraadt 468: }
469:
470: /* Returns the socket used for reading. */
471:
1.2 provos 472: int
1.201 markus 473: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 474: {
1.201 markus 475: return ssh->state->connection_in;
1.1 deraadt 476: }
477:
478: /* Returns the descriptor used for writing. */
479:
1.2 provos 480: int
1.201 markus 481: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 482: {
1.201 markus 483: return ssh->state->connection_out;
484: }
485:
486: /*
487: * Returns the IP-address of the remote host as a string. The returned
488: * string must not be freed.
489: */
490:
491: const char *
492: ssh_remote_ipaddr(struct ssh *ssh)
493: {
1.271 djm 494: int sock;
1.220 djm 495:
1.201 markus 496: /* Check whether we have cached the ipaddr. */
1.220 djm 497: if (ssh->remote_ipaddr == NULL) {
498: if (ssh_packet_connection_is_on_socket(ssh)) {
1.271 djm 499: sock = ssh->state->connection_in;
1.220 djm 500: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 djm 501: ssh->remote_port = get_peer_port(sock);
502: ssh->local_ipaddr = get_local_ipaddr(sock);
503: ssh->local_port = get_local_port(sock);
1.220 djm 504: } else {
505: ssh->remote_ipaddr = strdup("UNKNOWN");
1.230 djm 506: ssh->remote_port = 65535;
507: ssh->local_ipaddr = strdup("UNKNOWN");
508: ssh->local_port = 65535;
1.220 djm 509: }
510: }
1.201 markus 511: return ssh->remote_ipaddr;
1.1 deraadt 512: }
513:
1.220 djm 514: /* Returns the port number of the remote host. */
515:
516: int
517: ssh_remote_port(struct ssh *ssh)
518: {
519: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
520: return ssh->remote_port;
1.230 djm 521: }
522:
523: /*
524: * Returns the IP-address of the local host as a string. The returned
525: * string must not be freed.
526: */
527:
528: const char *
529: ssh_local_ipaddr(struct ssh *ssh)
530: {
531: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
532: return ssh->local_ipaddr;
533: }
534:
535: /* Returns the port number of the local host. */
536:
537: int
538: ssh_local_port(struct ssh *ssh)
539: {
540: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
541: return ssh->local_port;
1.266 djm 542: }
543:
544: /* Returns the routing domain of the input socket, or NULL if unavailable */
545: const char *
546: ssh_packet_rdomain_in(struct ssh *ssh)
547: {
548: if (ssh->rdomain_in != NULL)
549: return ssh->rdomain_in;
550: if (!ssh_packet_connection_is_on_socket(ssh))
551: return NULL;
552: ssh->rdomain_in = get_rdomain(ssh->state->connection_in);
553: return ssh->rdomain_in;
1.220 djm 554: }
555:
1.1 deraadt 556: /* Closes the connection and clears and frees internal data structures. */
557:
1.257 markus 558: static void
559: ssh_packet_close_internal(struct ssh *ssh, int do_close)
1.1 deraadt 560: {
1.201 markus 561: struct session_state *state = ssh->state;
562: u_int mode;
563:
564: if (!state->initialized)
1.14 markus 565: return;
1.201 markus 566: state->initialized = 0;
1.257 markus 567: if (do_close) {
568: if (state->connection_in == state->connection_out) {
569: close(state->connection_out);
570: } else {
571: close(state->connection_in);
572: close(state->connection_out);
573: }
1.14 markus 574: }
1.201 markus 575: sshbuf_free(state->input);
576: sshbuf_free(state->output);
577: sshbuf_free(state->outgoing_packet);
578: sshbuf_free(state->incoming_packet);
1.257 markus 579: for (mode = 0; mode < MODE_MAX; mode++) {
580: kex_free_newkeys(state->newkeys[mode]); /* current keys */
581: state->newkeys[mode] = NULL;
582: ssh_clear_newkeys(ssh, mode); /* next keys */
583: }
584: /* comression state is in shared mem, so we can only release it once */
585: if (do_close && state->compression_buffer) {
1.201 markus 586: sshbuf_free(state->compression_buffer);
587: if (state->compression_out_started) {
588: z_streamp stream = &state->compression_out_stream;
589: debug("compress outgoing: "
590: "raw data %llu, compressed %llu, factor %.2f",
591: (unsigned long long)stream->total_in,
592: (unsigned long long)stream->total_out,
593: stream->total_in == 0 ? 0.0 :
594: (double) stream->total_out / stream->total_in);
595: if (state->compression_out_failures == 0)
596: deflateEnd(stream);
597: }
598: if (state->compression_in_started) {
1.260 dtucker 599: z_streamp stream = &state->compression_in_stream;
1.201 markus 600: debug("compress incoming: "
601: "raw data %llu, compressed %llu, factor %.2f",
602: (unsigned long long)stream->total_out,
603: (unsigned long long)stream->total_in,
604: stream->total_out == 0 ? 0.0 :
605: (double) stream->total_in / stream->total_out);
606: if (state->compression_in_failures == 0)
607: inflateEnd(stream);
608: }
1.14 markus 609: }
1.235 djm 610: cipher_free(state->send_context);
611: cipher_free(state->receive_context);
612: state->send_context = state->receive_context = NULL;
1.257 markus 613: if (do_close) {
1.277 ! djm 614: free(ssh->local_ipaddr);
! 615: ssh->local_ipaddr = NULL;
1.257 markus 616: free(ssh->remote_ipaddr);
617: ssh->remote_ipaddr = NULL;
618: free(ssh->state);
619: ssh->state = NULL;
620: }
621: }
622:
623: void
624: ssh_packet_close(struct ssh *ssh)
625: {
626: ssh_packet_close_internal(ssh, 1);
627: }
628:
629: void
630: ssh_packet_clear_keys(struct ssh *ssh)
631: {
632: ssh_packet_close_internal(ssh, 0);
1.1 deraadt 633: }
634:
635: /* Sets remote side protocol flags. */
636:
1.2 provos 637: void
1.201 markus 638: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 639: {
1.201 markus 640: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 641: }
642:
643: /* Returns the remote protocol flags set earlier by the above function. */
644:
1.40 markus 645: u_int
1.201 markus 646: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 647: {
1.201 markus 648: return ssh->state->remote_protocol_flags;
1.1 deraadt 649: }
650:
1.16 markus 651: /*
652: * Starts packet compression from the next packet on in both directions.
653: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
654: */
1.1 deraadt 655:
1.201 markus 656: static int
657: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 658: {
1.201 markus 659: if (!ssh->state->compression_buffer &&
660: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
661: return SSH_ERR_ALLOC_FAIL;
662: return 0;
1.60 markus 663: }
664:
1.201 markus 665: static int
666: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 667: {
1.201 markus 668: if (level < 1 || level > 9)
669: return SSH_ERR_INVALID_ARGUMENT;
670: debug("Enabling compression at level %d.", level);
671: if (ssh->state->compression_out_started == 1)
672: deflateEnd(&ssh->state->compression_out_stream);
673: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
674: case Z_OK:
675: ssh->state->compression_out_started = 1;
676: break;
677: case Z_MEM_ERROR:
678: return SSH_ERR_ALLOC_FAIL;
679: default:
680: return SSH_ERR_INTERNAL_ERROR;
681: }
682: return 0;
1.1 deraadt 683: }
684:
1.201 markus 685: static int
686: start_compression_in(struct ssh *ssh)
687: {
688: if (ssh->state->compression_in_started == 1)
689: inflateEnd(&ssh->state->compression_in_stream);
690: switch (inflateInit(&ssh->state->compression_in_stream)) {
691: case Z_OK:
692: ssh->state->compression_in_started = 1;
693: break;
694: case Z_MEM_ERROR:
695: return SSH_ERR_ALLOC_FAIL;
696: default:
697: return SSH_ERR_INTERNAL_ERROR;
698: }
699: return 0;
1.95 markus 700: }
701:
1.201 markus 702: /* XXX remove need for separate compression buffer */
703: static int
704: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 705: {
1.201 markus 706: u_char buf[4096];
707: int r, status;
708:
709: if (ssh->state->compression_out_started != 1)
710: return SSH_ERR_INTERNAL_ERROR;
711:
712: /* This case is not handled below. */
713: if (sshbuf_len(in) == 0)
714: return 0;
715:
716: /* Input is the contents of the input buffer. */
717: if ((ssh->state->compression_out_stream.next_in =
718: sshbuf_mutable_ptr(in)) == NULL)
719: return SSH_ERR_INTERNAL_ERROR;
720: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
721:
722: /* Loop compressing until deflate() returns with avail_out != 0. */
723: do {
724: /* Set up fixed-size output buffer. */
725: ssh->state->compression_out_stream.next_out = buf;
726: ssh->state->compression_out_stream.avail_out = sizeof(buf);
727:
728: /* Compress as much data into the buffer as possible. */
729: status = deflate(&ssh->state->compression_out_stream,
730: Z_PARTIAL_FLUSH);
731: switch (status) {
732: case Z_MEM_ERROR:
733: return SSH_ERR_ALLOC_FAIL;
734: case Z_OK:
735: /* Append compressed data to output_buffer. */
736: if ((r = sshbuf_put(out, buf, sizeof(buf) -
737: ssh->state->compression_out_stream.avail_out)) != 0)
738: return r;
739: break;
740: case Z_STREAM_ERROR:
741: default:
742: ssh->state->compression_out_failures++;
743: return SSH_ERR_INVALID_FORMAT;
744: }
745: } while (ssh->state->compression_out_stream.avail_out == 0);
746: return 0;
1.1 deraadt 747: }
748:
1.201 markus 749: static int
750: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 751: {
1.201 markus 752: u_char buf[4096];
753: int r, status;
1.1 deraadt 754:
1.201 markus 755: if (ssh->state->compression_in_started != 1)
756: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 757:
1.201 markus 758: if ((ssh->state->compression_in_stream.next_in =
759: sshbuf_mutable_ptr(in)) == NULL)
760: return SSH_ERR_INTERNAL_ERROR;
761: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 762:
1.201 markus 763: for (;;) {
764: /* Set up fixed-size output buffer. */
765: ssh->state->compression_in_stream.next_out = buf;
766: ssh->state->compression_in_stream.avail_out = sizeof(buf);
767:
768: status = inflate(&ssh->state->compression_in_stream,
769: Z_PARTIAL_FLUSH);
770: switch (status) {
771: case Z_OK:
772: if ((r = sshbuf_put(out, buf, sizeof(buf) -
773: ssh->state->compression_in_stream.avail_out)) != 0)
774: return r;
775: break;
776: case Z_BUF_ERROR:
777: /*
778: * Comments in zlib.h say that we should keep calling
779: * inflate() until we get an error. This appears to
780: * be the error that we get.
781: */
782: return 0;
783: case Z_DATA_ERROR:
784: return SSH_ERR_INVALID_FORMAT;
785: case Z_MEM_ERROR:
786: return SSH_ERR_ALLOC_FAIL;
787: case Z_STREAM_ERROR:
788: default:
789: ssh->state->compression_in_failures++;
790: return SSH_ERR_INTERNAL_ERROR;
791: }
792: }
793: /* NOTREACHED */
1.170 djm 794: }
795:
1.257 markus 796: void
797: ssh_clear_newkeys(struct ssh *ssh, int mode)
798: {
1.259 djm 799: if (ssh->kex && ssh->kex->newkeys[mode]) {
1.257 markus 800: kex_free_newkeys(ssh->kex->newkeys[mode]);
801: ssh->kex->newkeys[mode] = NULL;
802: }
803: }
804:
1.201 markus 805: int
806: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 807: {
1.201 markus 808: struct session_state *state = ssh->state;
809: struct sshenc *enc;
810: struct sshmac *mac;
811: struct sshcomp *comp;
1.235 djm 812: struct sshcipher_ctx **ccp;
1.236 markus 813: struct packet_state *ps;
1.105 markus 814: u_int64_t *max_blocks;
1.259 djm 815: const char *wmsg;
1.197 djm 816: int r, crypt_type;
1.57 markus 817:
1.100 markus 818: debug2("set_newkeys: mode %d", mode);
1.57 markus 819:
1.88 markus 820: if (mode == MODE_OUT) {
1.235 djm 821: ccp = &state->send_context;
1.115 avsm 822: crypt_type = CIPHER_ENCRYPT;
1.236 markus 823: ps = &state->p_send;
1.201 markus 824: max_blocks = &state->max_blocks_out;
1.88 markus 825: } else {
1.235 djm 826: ccp = &state->receive_context;
1.115 avsm 827: crypt_type = CIPHER_DECRYPT;
1.236 markus 828: ps = &state->p_read;
1.201 markus 829: max_blocks = &state->max_blocks_in;
1.88 markus 830: }
1.201 markus 831: if (state->newkeys[mode] != NULL) {
1.257 markus 832: debug("set_newkeys: rekeying, input %llu bytes %llu blocks, "
833: "output %llu bytes %llu blocks",
834: (unsigned long long)state->p_read.bytes,
835: (unsigned long long)state->p_read.blocks,
836: (unsigned long long)state->p_send.bytes,
837: (unsigned long long)state->p_send.blocks);
1.235 djm 838: cipher_free(*ccp);
839: *ccp = NULL;
1.257 markus 840: kex_free_newkeys(state->newkeys[mode]);
841: state->newkeys[mode] = NULL;
1.57 markus 842: }
1.236 markus 843: /* note that both bytes and the seqnr are not reset */
844: ps->packets = ps->blocks = 0;
1.201 markus 845: /* move newkeys from kex to state */
846: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
847: return SSH_ERR_INTERNAL_ERROR;
848: ssh->kex->newkeys[mode] = NULL;
849: enc = &state->newkeys[mode]->enc;
850: mac = &state->newkeys[mode]->mac;
851: comp = &state->newkeys[mode]->comp;
852: if (cipher_authlen(enc->cipher) == 0) {
853: if ((r = mac_init(mac)) != 0)
854: return r;
855: }
856: mac->enabled = 1;
1.57 markus 857: DBG(debug("cipher_init_context: %d", mode));
1.235 djm 858: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 859: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 860: return r;
861: if (!state->cipher_warning_done &&
1.235 djm 862: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 863: error("Warning: %s", wmsg);
864: state->cipher_warning_done = 1;
865: }
1.91 markus 866: /* Deleting the keys does not gain extra security */
1.192 djm 867: /* explicit_bzero(enc->iv, enc->block_size);
868: explicit_bzero(enc->key, enc->key_len);
869: explicit_bzero(mac->key, mac->key_len); */
1.275 sf 870: if ((comp->type == COMP_ZLIB ||
871: (comp->type == COMP_DELAYED &&
872: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 873: if ((r = ssh_packet_init_compression(ssh)) < 0)
874: return r;
875: if (mode == MODE_OUT) {
876: if ((r = start_compression_out(ssh, 6)) != 0)
877: return r;
878: } else {
879: if ((r = start_compression_in(ssh)) != 0)
880: return r;
881: }
1.57 markus 882: comp->enabled = 1;
883: }
1.109 markus 884: /*
885: * The 2^(blocksize*2) limit is too expensive for 3DES,
1.254 djm 886: * so enforce a 1GB limit for small blocksizes.
1.261 dtucker 887: * See RFC4344 section 3.2.
1.109 markus 888: */
889: if (enc->block_size >= 16)
890: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
891: else
892: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 893: if (state->rekey_limit)
1.237 deraadt 894: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 895: state->rekey_limit / enc->block_size);
1.227 djm 896: debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1.201 markus 897: return 0;
1.57 markus 898: }
899:
1.228 djm 900: #define MAX_PACKETS (1U<<31)
901: static int
902: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
903: {
904: struct session_state *state = ssh->state;
905: u_int32_t out_blocks;
906:
907: /* XXX client can't cope with rekeying pre-auth */
908: if (!state->after_authentication)
909: return 0;
910:
911: /* Haven't keyed yet or KEX in progress. */
912: if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
913: return 0;
914:
915: /* Peer can't rekey */
916: if (ssh->compat & SSH_BUG_NOREKEY)
917: return 0;
918:
919: /*
920: * Permit one packet in or out per rekey - this allows us to
921: * make progress when rekey limits are very small.
922: */
923: if (state->p_send.packets == 0 && state->p_read.packets == 0)
924: return 0;
925:
926: /* Time-based rekeying */
927: if (state->rekey_interval != 0 &&
1.244 dtucker 928: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 929: return 1;
930:
1.261 dtucker 931: /*
932: * Always rekey when MAX_PACKETS sent in either direction
933: * As per RFC4344 section 3.1 we do this after 2^31 packets.
934: */
1.228 djm 935: if (state->p_send.packets > MAX_PACKETS ||
936: state->p_read.packets > MAX_PACKETS)
937: return 1;
938:
939: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 940: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 941: state->newkeys[MODE_OUT]->enc.block_size);
942: return (state->max_blocks_out &&
943: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
944: (state->max_blocks_in &&
945: (state->p_read.blocks > state->max_blocks_in));
946: }
947:
1.16 markus 948: /*
1.118 markus 949: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 950: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 951: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
952: */
1.201 markus 953: static int
954: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 955: {
1.201 markus 956: struct session_state *state = ssh->state;
957: struct sshcomp *comp = NULL;
958: int r, mode;
1.118 markus 959:
960: /*
961: * Remember that we are past the authentication step, so rekeying
1.275 sf 962: * with COMP_DELAYED will turn on compression immediately.
1.118 markus 963: */
1.201 markus 964: state->after_authentication = 1;
1.118 markus 965: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 966: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 967: if (state->newkeys[mode] == NULL)
1.145 markus 968: continue;
1.201 markus 969: comp = &state->newkeys[mode]->comp;
1.275 sf 970: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 971: if ((r = ssh_packet_init_compression(ssh)) != 0)
972: return r;
973: if (mode == MODE_OUT) {
974: if ((r = start_compression_out(ssh, 6)) != 0)
975: return r;
976: } else {
977: if ((r = start_compression_in(ssh)) != 0)
978: return r;
979: }
1.118 markus 980: comp->enabled = 1;
981: }
982: }
1.201 markus 983: return 0;
1.118 markus 984: }
985:
1.226 djm 986: /* Used to mute debug logging for noisy packet types */
1.242 markus 987: int
1.226 djm 988: ssh_packet_log_type(u_char type)
989: {
990: switch (type) {
991: case SSH2_MSG_CHANNEL_DATA:
992: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
993: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
994: return 0;
995: default:
996: return 1;
997: }
998: }
999:
1.118 markus 1000: /*
1.25 markus 1001: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1002: */
1.201 markus 1003: int
1004: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1005: {
1.201 markus 1006: struct session_state *state = ssh->state;
1.200 markus 1007: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1008: u_char tmp, padlen, pad = 0;
1.201 markus 1009: u_int authlen = 0, aadlen = 0;
1010: u_int len;
1011: struct sshenc *enc = NULL;
1012: struct sshmac *mac = NULL;
1013: struct sshcomp *comp = NULL;
1014: int r, block_size;
1015:
1016: if (state->newkeys[MODE_OUT] != NULL) {
1017: enc = &state->newkeys[MODE_OUT]->enc;
1018: mac = &state->newkeys[MODE_OUT]->mac;
1019: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1020: /* disable mac for authenticated encryption */
1021: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1022: mac = NULL;
1.25 markus 1023: }
1.88 markus 1024: block_size = enc ? enc->block_size : 8;
1.180 markus 1025: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1026:
1.201 markus 1027: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1028: if (ssh_packet_log_type(type))
1029: debug3("send packet: type %u", type);
1.25 markus 1030: #ifdef PACKET_DEBUG
1031: fprintf(stderr, "plain: ");
1.201 markus 1032: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1033: #endif
1034:
1035: if (comp && comp->enabled) {
1.201 markus 1036: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1037: /* skip header, compress only payload */
1.201 markus 1038: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1039: goto out;
1040: sshbuf_reset(state->compression_buffer);
1041: if ((r = compress_buffer(ssh, state->outgoing_packet,
1042: state->compression_buffer)) != 0)
1043: goto out;
1044: sshbuf_reset(state->outgoing_packet);
1045: if ((r = sshbuf_put(state->outgoing_packet,
1046: "\0\0\0\0\0", 5)) != 0 ||
1047: (r = sshbuf_putb(state->outgoing_packet,
1048: state->compression_buffer)) != 0)
1049: goto out;
1050: DBG(debug("compression: raw %d compressed %zd", len,
1051: sshbuf_len(state->outgoing_packet)));
1.25 markus 1052: }
1053:
1054: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1055: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1056:
1057: /*
1058: * calc size of padding, alloc space, get random data,
1059: * minimum padding is 4 bytes
1060: */
1.178 markus 1061: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1062: padlen = block_size - (len % block_size);
1063: if (padlen < 4)
1064: padlen += block_size;
1.201 markus 1065: if (state->extra_pad) {
1.233 djm 1066: tmp = state->extra_pad;
1.201 markus 1067: state->extra_pad =
1.237 deraadt 1068: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1069: /* check if roundup overflowed */
1070: if (state->extra_pad < tmp)
1071: return SSH_ERR_INVALID_ARGUMENT;
1072: tmp = (len + padlen) % state->extra_pad;
1073: /* Check whether pad calculation below will underflow */
1074: if (tmp > state->extra_pad)
1075: return SSH_ERR_INVALID_ARGUMENT;
1076: pad = state->extra_pad - tmp;
1.193 djm 1077: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1078: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1079: tmp = padlen;
1.71 markus 1080: padlen += pad;
1.233 djm 1081: /* Check whether padlen calculation overflowed */
1082: if (padlen < tmp)
1083: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1084: state->extra_pad = 0;
1.71 markus 1085: }
1.201 markus 1086: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1087: goto out;
1.235 djm 1088: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1089: /* random padding */
1.201 markus 1090: arc4random_buf(cp, padlen);
1.32 markus 1091: } else {
1092: /* clear padding */
1.192 djm 1093: explicit_bzero(cp, padlen);
1.25 markus 1094: }
1.178 markus 1095: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1096: len = sshbuf_len(state->outgoing_packet);
1097: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1098: if (cp == NULL) {
1099: r = SSH_ERR_INTERNAL_ERROR;
1100: goto out;
1101: }
1.25 markus 1102: /* packet_length includes payload, padding and padding length field */
1.201 markus 1103: POKE_U32(cp, len - 4);
1.89 markus 1104: cp[4] = padlen;
1.178 markus 1105: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1106: len, padlen, aadlen));
1.25 markus 1107:
1108: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1109: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1110: if ((r = mac_compute(mac, state->p_send.seqnr,
1111: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1112: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1113: goto out;
1114: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1115: }
1116: /* encrypt packet and append to output buffer. */
1.201 markus 1117: if ((r = sshbuf_reserve(state->output,
1118: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1119: goto out;
1.235 djm 1120: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1121: sshbuf_ptr(state->outgoing_packet),
1122: len - aadlen, aadlen, authlen)) != 0)
1123: goto out;
1.25 markus 1124: /* append unencrypted MAC */
1.178 markus 1125: if (mac && mac->enabled) {
1126: if (mac->etm) {
1127: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1128: if ((r = mac_compute(mac, state->p_send.seqnr,
1129: cp, len, macbuf, sizeof(macbuf))) != 0)
1130: goto out;
1.178 markus 1131: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1132: state->p_send.seqnr));
1.178 markus 1133: }
1.201 markus 1134: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1135: goto out;
1.178 markus 1136: }
1.25 markus 1137: #ifdef PACKET_DEBUG
1138: fprintf(stderr, "encrypted: ");
1.201 markus 1139: sshbuf_dump(state->output, stderr);
1.25 markus 1140: #endif
1.29 markus 1141: /* increment sequence number for outgoing packets */
1.201 markus 1142: if (++state->p_send.seqnr == 0)
1.106 itojun 1143: logit("outgoing seqnr wraps around");
1.201 markus 1144: if (++state->p_send.packets == 0)
1145: if (!(ssh->compat & SSH_BUG_NOREKEY))
1146: return SSH_ERR_NEED_REKEY;
1147: state->p_send.blocks += len / block_size;
1148: state->p_send.bytes += len;
1149: sshbuf_reset(state->outgoing_packet);
1.25 markus 1150:
1.57 markus 1151: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1152: r = ssh_set_newkeys(ssh, MODE_OUT);
1153: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1154: r = ssh_packet_enable_delayed_compress(ssh);
1155: else
1156: r = 0;
1157: out:
1158: return r;
1.25 markus 1159: }
1160:
1.228 djm 1161: /* returns non-zero if the specified packet type is usec by KEX */
1162: static int
1163: ssh_packet_type_is_kex(u_char type)
1164: {
1165: return
1166: type >= SSH2_MSG_TRANSPORT_MIN &&
1167: type <= SSH2_MSG_TRANSPORT_MAX &&
1168: type != SSH2_MSG_SERVICE_REQUEST &&
1169: type != SSH2_MSG_SERVICE_ACCEPT &&
1170: type != SSH2_MSG_EXT_INFO;
1171: }
1172:
1.201 markus 1173: int
1174: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1175: {
1.201 markus 1176: struct session_state *state = ssh->state;
1.105 markus 1177: struct packet *p;
1.201 markus 1178: u_char type;
1.228 djm 1179: int r, need_rekey;
1.105 markus 1180:
1.228 djm 1181: if (sshbuf_len(state->outgoing_packet) < 6)
1182: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1183: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1184: need_rekey = !ssh_packet_type_is_kex(type) &&
1185: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1186:
1.228 djm 1187: /*
1188: * During rekeying we can only send key exchange messages.
1189: * Queue everything else.
1190: */
1191: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1192: if (need_rekey)
1193: debug3("%s: rekex triggered", __func__);
1194: debug("enqueue packet: %u", type);
1195: p = calloc(1, sizeof(*p));
1196: if (p == NULL)
1197: return SSH_ERR_ALLOC_FAIL;
1198: p->type = type;
1199: p->payload = state->outgoing_packet;
1200: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1201: state->outgoing_packet = sshbuf_new();
1202: if (state->outgoing_packet == NULL)
1203: return SSH_ERR_ALLOC_FAIL;
1204: if (need_rekey) {
1205: /*
1206: * This packet triggered a rekey, so send the
1207: * KEXINIT now.
1208: * NB. reenters this function via kex_start_rekex().
1209: */
1210: return kex_start_rekex(ssh);
1.105 markus 1211: }
1.228 djm 1212: return 0;
1.105 markus 1213: }
1214:
1215: /* rekeying starts with sending KEXINIT */
1216: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1217: state->rekeying = 1;
1.105 markus 1218:
1.201 markus 1219: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1220: return r;
1.105 markus 1221:
1222: /* after a NEWKEYS message we can send the complete queue */
1223: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1224: state->rekeying = 0;
1225: state->rekey_time = monotime();
1226: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1227: type = p->type;
1.228 djm 1228: /*
1229: * If this packet triggers a rekex, then skip the
1230: * remaining packets in the queue for now.
1231: * NB. re-enters this function via kex_start_rekex.
1232: */
1233: if (ssh_packet_need_rekeying(ssh,
1234: sshbuf_len(p->payload))) {
1235: debug3("%s: queued packet triggered rekex",
1236: __func__);
1237: return kex_start_rekex(ssh);
1238: }
1.105 markus 1239: debug("dequeue packet: %u", type);
1.201 markus 1240: sshbuf_free(state->outgoing_packet);
1241: state->outgoing_packet = p->payload;
1242: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1243: memset(p, 0, sizeof(*p));
1.186 djm 1244: free(p);
1.201 markus 1245: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1246: return r;
1.105 markus 1247: }
1248: }
1.201 markus 1249: return 0;
1.25 markus 1250: }
1251:
1252: /*
1.16 markus 1253: * Waits until a packet has been received, and returns its type. Note that
1254: * no other data is processed until this returns, so this function should not
1255: * be used during the interactive session.
1256: */
1.1 deraadt 1257:
1.2 provos 1258: int
1.201 markus 1259: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1260: {
1.201 markus 1261: struct session_state *state = ssh->state;
1.222 markus 1262: int len, r, ms_remain;
1.56 millert 1263: fd_set *setp;
1.14 markus 1264: char buf[8192];
1.155 deraadt 1265: struct timeval timeout, start, *timeoutp = NULL;
1266:
1.25 markus 1267: DBG(debug("packet_read()"));
1.14 markus 1268:
1.214 deraadt 1269: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1270: NFDBITS), sizeof(fd_mask));
1.201 markus 1271: if (setp == NULL)
1272: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1273:
1.205 djm 1274: /*
1275: * Since we are blocking, ensure that all written packets have
1276: * been sent.
1277: */
1.210 markus 1278: if ((r = ssh_packet_write_wait(ssh)) != 0)
1279: goto out;
1.14 markus 1280:
1281: /* Stay in the loop until we have received a complete packet. */
1282: for (;;) {
1283: /* Try to read a packet from the buffer. */
1.201 markus 1284: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1285: if (r != 0)
1286: break;
1.14 markus 1287: /* If we got a packet, return it. */
1.201 markus 1288: if (*typep != SSH_MSG_NONE)
1289: break;
1.16 markus 1290: /*
1291: * Otherwise, wait for some data to arrive, add it to the
1292: * buffer, and try again.
1293: */
1.201 markus 1294: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1295: NFDBITS) * sizeof(fd_mask));
1.201 markus 1296: FD_SET(state->connection_in, setp);
1.16 markus 1297:
1.201 markus 1298: if (state->packet_timeout_ms > 0) {
1299: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1300: timeoutp = &timeout;
1301: }
1.14 markus 1302: /* Wait for some data to arrive. */
1.154 dtucker 1303: for (;;) {
1.201 markus 1304: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1305: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1306: monotime_tv(&start);
1.154 dtucker 1307: }
1.201 markus 1308: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1309: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1310: break;
1.270 dtucker 1311: if (errno != EAGAIN && errno != EINTR) {
1312: r = SSH_ERR_SYSTEM_ERROR;
1313: goto out;
1314: }
1.201 markus 1315: if (state->packet_timeout_ms == -1)
1.154 dtucker 1316: continue;
1317: ms_subtract_diff(&start, &ms_remain);
1318: if (ms_remain <= 0) {
1.201 markus 1319: r = 0;
1.154 dtucker 1320: break;
1321: }
1322: }
1.246 djm 1323: if (r == 0) {
1324: r = SSH_ERR_CONN_TIMEOUT;
1325: goto out;
1326: }
1.14 markus 1327: /* Read data from the socket. */
1.222 markus 1328: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1329: if (len == 0) {
1330: r = SSH_ERR_CONN_CLOSED;
1331: goto out;
1332: }
1333: if (len < 0) {
1334: r = SSH_ERR_SYSTEM_ERROR;
1335: goto out;
1336: }
1.204 djm 1337:
1.14 markus 1338: /* Append it to the buffer. */
1.204 djm 1339: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1340: goto out;
1.14 markus 1341: }
1.210 markus 1342: out:
1.201 markus 1343: free(setp);
1344: return r;
1.1 deraadt 1345: }
1346:
1.77 djm 1347: int
1.201 markus 1348: ssh_packet_read(struct ssh *ssh)
1.77 djm 1349: {
1.201 markus 1350: u_char type;
1351: int r;
1352:
1353: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1354: fatal("%s: %s", __func__, ssh_err(r));
1355: return type;
1.77 djm 1356: }
1357:
1.16 markus 1358: /*
1359: * Waits until a packet has been received, verifies that its type matches
1360: * that given, and gives a fatal error and exits if there is a mismatch.
1361: */
1.1 deraadt 1362:
1.205 djm 1363: int
1364: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1365: {
1.205 djm 1366: int r;
1367: u_char type;
1.1 deraadt 1368:
1.205 djm 1369: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1370: return r;
1371: if (type != expected_type) {
1372: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1373: "Protocol error: expected packet type %d, got %d",
1.205 djm 1374: expected_type, type)) != 0)
1375: return r;
1376: return SSH_ERR_PROTOCOL_ERROR;
1377: }
1378: return 0;
1.1 deraadt 1379: }
1.14 markus 1380:
1.242 markus 1381: static int
1382: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1383: {
1384: struct session_state *state = ssh->state;
1385: const u_char *cp;
1386: size_t need;
1387: int r;
1388:
1389: if (ssh->kex)
1390: return SSH_ERR_INTERNAL_ERROR;
1391: *typep = SSH_MSG_NONE;
1392: cp = sshbuf_ptr(state->input);
1393: if (state->packlen == 0) {
1394: if (sshbuf_len(state->input) < 4 + 1)
1395: return 0; /* packet is incomplete */
1396: state->packlen = PEEK_U32(cp);
1397: if (state->packlen < 4 + 1 ||
1398: state->packlen > PACKET_MAX_SIZE)
1399: return SSH_ERR_MESSAGE_INCOMPLETE;
1400: }
1401: need = state->packlen + 4;
1402: if (sshbuf_len(state->input) < need)
1403: return 0; /* packet is incomplete */
1404: sshbuf_reset(state->incoming_packet);
1405: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1406: state->packlen)) != 0 ||
1407: (r = sshbuf_consume(state->input, need)) != 0 ||
1408: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1409: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1410: return r;
1411: if (ssh_packet_log_type(*typep))
1412: debug3("%s: type %u", __func__, *typep);
1413: /* sshbuf_dump(state->incoming_packet, stderr); */
1414: /* reset for next packet */
1415: state->packlen = 0;
1416: return r;
1417: }
1418:
1.201 markus 1419: int
1420: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1421: {
1.201 markus 1422: struct session_state *state = ssh->state;
1.40 markus 1423: u_int padlen, need;
1.231 djm 1424: u_char *cp;
1.201 markus 1425: u_int maclen, aadlen = 0, authlen = 0, block_size;
1426: struct sshenc *enc = NULL;
1427: struct sshmac *mac = NULL;
1428: struct sshcomp *comp = NULL;
1.200 markus 1429: int r;
1.201 markus 1430:
1.242 markus 1431: if (state->mux)
1432: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1433:
1.201 markus 1434: *typep = SSH_MSG_NONE;
1435:
1436: if (state->packet_discard)
1437: return 0;
1438:
1439: if (state->newkeys[MODE_IN] != NULL) {
1440: enc = &state->newkeys[MODE_IN]->enc;
1441: mac = &state->newkeys[MODE_IN]->mac;
1442: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1443: /* disable mac for authenticated encryption */
1444: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1445: mac = NULL;
1.25 markus 1446: }
1447: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1448: block_size = enc ? enc->block_size : 8;
1.180 markus 1449: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1450:
1.201 markus 1451: if (aadlen && state->packlen == 0) {
1.235 djm 1452: if (cipher_get_length(state->receive_context,
1.201 markus 1453: &state->packlen, state->p_read.seqnr,
1454: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1455: return 0;
1456: if (state->packlen < 1 + 4 ||
1457: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1458: #ifdef PACKET_DEBUG
1.201 markus 1459: sshbuf_dump(state->input, stderr);
1.178 markus 1460: #endif
1.201 markus 1461: logit("Bad packet length %u.", state->packlen);
1462: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1463: return r;
1.217 djm 1464: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1465: }
1.201 markus 1466: sshbuf_reset(state->incoming_packet);
1467: } else if (state->packlen == 0) {
1.25 markus 1468: /*
1469: * check if input size is less than the cipher block size,
1470: * decrypt first block and extract length of incoming packet
1471: */
1.201 markus 1472: if (sshbuf_len(state->input) < block_size)
1473: return 0;
1474: sshbuf_reset(state->incoming_packet);
1475: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1476: &cp)) != 0)
1477: goto out;
1.235 djm 1478: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1479: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1480: block_size, 0, 0)) != 0)
1481: goto out;
1482: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1483: if (state->packlen < 1 + 4 ||
1484: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1485: #ifdef PACKET_DEBUG
1.201 markus 1486: fprintf(stderr, "input: \n");
1487: sshbuf_dump(state->input, stderr);
1488: fprintf(stderr, "incoming_packet: \n");
1489: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1490: #endif
1.201 markus 1491: logit("Bad packet length %u.", state->packlen);
1.234 markus 1492: return ssh_packet_start_discard(ssh, enc, mac, 0,
1493: PACKET_MAX_SIZE);
1.25 markus 1494: }
1.201 markus 1495: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1496: goto out;
1.25 markus 1497: }
1.201 markus 1498: DBG(debug("input: packet len %u", state->packlen+4));
1499:
1.178 markus 1500: if (aadlen) {
1501: /* only the payload is encrypted */
1.201 markus 1502: need = state->packlen;
1.178 markus 1503: } else {
1504: /*
1505: * the payload size and the payload are encrypted, but we
1506: * have a partial packet of block_size bytes
1507: */
1.201 markus 1508: need = 4 + state->packlen - block_size;
1.178 markus 1509: }
1.180 markus 1510: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1511: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1512: if (need % block_size != 0) {
1513: logit("padding error: need %d block %d mod %d",
1.25 markus 1514: need, block_size, need % block_size);
1.234 markus 1515: return ssh_packet_start_discard(ssh, enc, mac, 0,
1516: PACKET_MAX_SIZE - block_size);
1.158 markus 1517: }
1.25 markus 1518: /*
1519: * check if the entire packet has been received and
1.178 markus 1520: * decrypt into incoming_packet:
1521: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1522: * 'need' bytes are encrypted, followed by either
1523: * 'authlen' bytes of authentication tag or
1.178 markus 1524: * 'maclen' bytes of message authentication code.
1.25 markus 1525: */
1.201 markus 1526: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1527: return 0; /* packet is incomplete */
1.25 markus 1528: #ifdef PACKET_DEBUG
1529: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1530: sshbuf_dump(state->input, stderr);
1.25 markus 1531: #endif
1.231 djm 1532: /* EtM: check mac over encrypted input */
1.201 markus 1533: if (mac && mac->enabled && mac->etm) {
1.231 djm 1534: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1535: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1536: sshbuf_ptr(state->input) + aadlen + need + authlen,
1537: maclen)) != 0) {
1538: if (r == SSH_ERR_MAC_INVALID)
1539: logit("Corrupted MAC on input.");
1.201 markus 1540: goto out;
1.231 djm 1541: }
1.201 markus 1542: }
1543: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1544: &cp)) != 0)
1545: goto out;
1.235 djm 1546: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1547: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1548: goto out;
1549: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1550: goto out;
1.29 markus 1551: if (mac && mac->enabled) {
1.231 djm 1552: /* Not EtM: check MAC over cleartext */
1553: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1554: sshbuf_ptr(state->incoming_packet),
1555: sshbuf_len(state->incoming_packet),
1556: sshbuf_ptr(state->input), maclen)) != 0) {
1557: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1558: goto out;
1.159 markus 1559: logit("Corrupted MAC on input.");
1.247 markus 1560: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1561: return SSH_ERR_INTERNAL_ERROR;
1562: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1563: sshbuf_len(state->incoming_packet),
1.247 markus 1564: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1565: }
1.231 djm 1566: /* Remove MAC from input buffer */
1.201 markus 1567: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1568: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1569: goto out;
1.25 markus 1570: }
1.77 djm 1571: if (seqnr_p != NULL)
1.201 markus 1572: *seqnr_p = state->p_read.seqnr;
1573: if (++state->p_read.seqnr == 0)
1.106 itojun 1574: logit("incoming seqnr wraps around");
1.201 markus 1575: if (++state->p_read.packets == 0)
1576: if (!(ssh->compat & SSH_BUG_NOREKEY))
1577: return SSH_ERR_NEED_REKEY;
1578: state->p_read.blocks += (state->packlen + 4) / block_size;
1579: state->p_read.bytes += state->packlen + 4;
1.25 markus 1580:
1581: /* get padlen */
1.201 markus 1582: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1583: DBG(debug("input: padlen %d", padlen));
1.205 djm 1584: if (padlen < 4) {
1585: if ((r = sshpkt_disconnect(ssh,
1586: "Corrupted padlen %d on input.", padlen)) != 0 ||
1587: (r = ssh_packet_write_wait(ssh)) != 0)
1588: return r;
1589: return SSH_ERR_CONN_CORRUPT;
1590: }
1.25 markus 1591:
1592: /* skip packet size + padlen, discard padding */
1.201 markus 1593: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1594: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1595: goto out;
1.25 markus 1596:
1.201 markus 1597: DBG(debug("input: len before de-compress %zd",
1598: sshbuf_len(state->incoming_packet)));
1.25 markus 1599: if (comp && comp->enabled) {
1.201 markus 1600: sshbuf_reset(state->compression_buffer);
1601: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1602: state->compression_buffer)) != 0)
1603: goto out;
1604: sshbuf_reset(state->incoming_packet);
1605: if ((r = sshbuf_putb(state->incoming_packet,
1606: state->compression_buffer)) != 0)
1607: goto out;
1608: DBG(debug("input: len after de-compress %zd",
1609: sshbuf_len(state->incoming_packet)));
1.25 markus 1610: }
1611: /*
1612: * get packet type, implies consume.
1613: * return length of payload (without type field)
1614: */
1.201 markus 1615: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1616: goto out;
1.226 djm 1617: if (ssh_packet_log_type(*typep))
1618: debug3("receive packet: type %u", *typep);
1.205 djm 1619: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1620: if ((r = sshpkt_disconnect(ssh,
1621: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1622: (r = ssh_packet_write_wait(ssh)) != 0)
1623: return r;
1624: return SSH_ERR_PROTOCOL_ERROR;
1625: }
1.243 djm 1626: if (state->hook_in != NULL &&
1627: (r = state->hook_in(ssh, state->incoming_packet, typep,
1628: state->hook_in_ctx)) != 0)
1629: return r;
1.238 markus 1630: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1631: r = ssh_packet_enable_delayed_compress(ssh);
1632: else
1633: r = 0;
1.25 markus 1634: #ifdef PACKET_DEBUG
1.201 markus 1635: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1636: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1637: #endif
1.62 markus 1638: /* reset for next packet */
1.201 markus 1639: state->packlen = 0;
1.228 djm 1640:
1641: /* do we need to rekey? */
1642: if (ssh_packet_need_rekeying(ssh, 0)) {
1643: debug3("%s: rekex triggered", __func__);
1644: if ((r = kex_start_rekex(ssh)) != 0)
1645: return r;
1646: }
1.201 markus 1647: out:
1648: return r;
1.25 markus 1649: }
1650:
1651: int
1.201 markus 1652: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1653: {
1.201 markus 1654: struct session_state *state = ssh->state;
1.96 deraadt 1655: u_int reason, seqnr;
1.201 markus 1656: int r;
1657: u_char *msg;
1.62 markus 1658:
1.25 markus 1659: for (;;) {
1.201 markus 1660: msg = NULL;
1.249 djm 1661: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1662: if (r != 0)
1663: return r;
1664: if (*typep) {
1665: state->keep_alive_timeouts = 0;
1666: DBG(debug("received packet type %d", *typep));
1667: }
1668: switch (*typep) {
1669: case SSH2_MSG_IGNORE:
1670: debug3("Received SSH2_MSG_IGNORE");
1671: break;
1672: case SSH2_MSG_DEBUG:
1673: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1674: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1675: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1676: free(msg);
1.201 markus 1677: return r;
1.48 stevesk 1678: }
1.249 djm 1679: debug("Remote: %.900s", msg);
1680: free(msg);
1681: break;
1682: case SSH2_MSG_DISCONNECT:
1683: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1684: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1685: return r;
1686: /* Ignore normal client exit notifications */
1687: do_log2(ssh->state->server_side &&
1688: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1689: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1690: "Received disconnect from %s port %d:"
1691: "%u: %.400s", ssh_remote_ipaddr(ssh),
1692: ssh_remote_port(ssh), reason, msg);
1693: free(msg);
1694: return SSH_ERR_DISCONNECTED;
1695: case SSH2_MSG_UNIMPLEMENTED:
1696: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1697: return r;
1698: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1699: seqnr);
1700: break;
1701: default:
1702: return 0;
1.25 markus 1703: }
1704: }
1705: }
1706:
1.16 markus 1707: /*
1708: * Buffers the given amount of input characters. This is intended to be used
1709: * together with packet_read_poll.
1710: */
1.1 deraadt 1711:
1.204 djm 1712: int
1.201 markus 1713: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1714: {
1.201 markus 1715: struct session_state *state = ssh->state;
1716: int r;
1717:
1718: if (state->packet_discard) {
1719: state->keep_alive_timeouts = 0; /* ?? */
1720: if (len >= state->packet_discard) {
1721: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1722: return r;
1.201 markus 1723: }
1724: state->packet_discard -= len;
1.204 djm 1725: return 0;
1.159 markus 1726: }
1.201 markus 1727: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1728: return r;
1729:
1730: return 0;
1.28 markus 1731: }
1732:
1733: int
1.201 markus 1734: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1735: {
1.201 markus 1736: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1737: }
1738:
1.16 markus 1739: /*
1740: * Sends a diagnostic message from the server to the client. This message
1741: * can be sent at any time (but not while constructing another message). The
1742: * message is printed immediately, but only if the client is being executed
1743: * in verbose mode. These messages are primarily intended to ease debugging
1744: * authentication problems. The length of the formatted message must not
1.205 djm 1745: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1746: */
1.2 provos 1747: void
1.201 markus 1748: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1749: {
1.14 markus 1750: char buf[1024];
1751: va_list args;
1.201 markus 1752: int r;
1.39 markus 1753:
1.249 djm 1754: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1755: return;
1.14 markus 1756:
1757: va_start(args, fmt);
1758: vsnprintf(buf, sizeof(buf), fmt, args);
1759: va_end(args);
1.265 djm 1760:
1761: debug3("sending debug message: %s", buf);
1.14 markus 1762:
1.249 djm 1763: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1764: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1765: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1766: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1767: (r = sshpkt_send(ssh)) != 0 ||
1768: (r = ssh_packet_write_wait(ssh)) != 0)
1.205 djm 1769: fatal("%s: %s", __func__, ssh_err(r));
1770: }
1771:
1.268 dtucker 1772: void
1773: sshpkt_fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1.245 djm 1774: {
1775: snprintf(s, l, "%.200s%s%s port %d",
1776: ssh->log_preamble ? ssh->log_preamble : "",
1777: ssh->log_preamble ? " " : "",
1778: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1779: }
1780:
1.205 djm 1781: /*
1782: * Pretty-print connection-terminating errors and exit.
1783: */
1784: void
1785: sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
1786: {
1.245 djm 1787: char remote_id[512];
1788:
1.268 dtucker 1789: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.245 djm 1790:
1.205 djm 1791: switch (r) {
1792: case SSH_ERR_CONN_CLOSED:
1.257 markus 1793: ssh_packet_clear_keys(ssh);
1.245 djm 1794: logdie("Connection closed by %s", remote_id);
1.205 djm 1795: case SSH_ERR_CONN_TIMEOUT:
1.257 markus 1796: ssh_packet_clear_keys(ssh);
1.245 djm 1797: logdie("Connection %s %s timed out",
1798: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1799: case SSH_ERR_DISCONNECTED:
1.257 markus 1800: ssh_packet_clear_keys(ssh);
1.245 djm 1801: logdie("Disconnected from %s", remote_id);
1.212 djm 1802: case SSH_ERR_SYSTEM_ERROR:
1.257 markus 1803: if (errno == ECONNRESET) {
1804: ssh_packet_clear_keys(ssh);
1.245 djm 1805: logdie("Connection reset by %s", remote_id);
1.257 markus 1806: }
1.213 djm 1807: /* FALLTHROUGH */
1808: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1809: case SSH_ERR_NO_MAC_ALG_MATCH:
1810: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1811: case SSH_ERR_NO_KEX_ALG_MATCH:
1812: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1813: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.257 markus 1814: ssh_packet_clear_keys(ssh);
1.245 djm 1815: logdie("Unable to negotiate with %s: %s. "
1816: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1817: ssh->kex->failed_choice);
1.212 djm 1818: }
1819: /* FALLTHROUGH */
1.205 djm 1820: default:
1.257 markus 1821: ssh_packet_clear_keys(ssh);
1.245 djm 1822: logdie("%s%sConnection %s %s: %s",
1.205 djm 1823: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 1824: ssh->state->server_side ? "from" : "to",
1.245 djm 1825: remote_id, ssh_err(r));
1.205 djm 1826: }
1.1 deraadt 1827: }
1828:
1.16 markus 1829: /*
1830: * Logs the error plus constructs and sends a disconnect packet, closes the
1831: * connection, and exits. This function never returns. The error message
1832: * should not contain a newline. The length of the formatted message must
1833: * not exceed 1024 bytes.
1834: */
1.2 provos 1835: void
1.201 markus 1836: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1837: {
1.245 djm 1838: char buf[1024], remote_id[512];
1.14 markus 1839: va_list args;
1840: static int disconnecting = 0;
1.201 markus 1841: int r;
1.97 deraadt 1842:
1.14 markus 1843: if (disconnecting) /* Guard against recursive invocations. */
1844: fatal("packet_disconnect called recursively.");
1845: disconnecting = 1;
1846:
1.16 markus 1847: /*
1848: * Format the message. Note that the caller must make sure the
1849: * message is of limited size.
1850: */
1.268 dtucker 1851: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1852: va_start(args, fmt);
1853: vsnprintf(buf, sizeof(buf), fmt, args);
1854: va_end(args);
1855:
1.99 markus 1856: /* Display the error locally */
1.245 djm 1857: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1858:
1.205 djm 1859: /*
1860: * Send the disconnect message to the other side, and wait
1861: * for it to get sent.
1862: */
1863: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1864: sshpkt_fatal(ssh, __func__, r);
1865:
1866: if ((r = ssh_packet_write_wait(ssh)) != 0)
1867: sshpkt_fatal(ssh, __func__, r);
1.14 markus 1868:
1869: /* Close the connection. */
1.201 markus 1870: ssh_packet_close(ssh);
1.112 markus 1871: cleanup_exit(255);
1.1 deraadt 1872: }
1873:
1.205 djm 1874: /*
1875: * Checks if there is any buffered output, and tries to write some of
1876: * the output.
1877: */
1878: int
1.201 markus 1879: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1880: {
1.201 markus 1881: struct session_state *state = ssh->state;
1882: int len = sshbuf_len(state->output);
1.222 markus 1883: int r;
1.97 deraadt 1884:
1.14 markus 1885: if (len > 0) {
1.222 markus 1886: len = write(state->connection_out,
1887: sshbuf_ptr(state->output), len);
1.156 djm 1888: if (len == -1) {
1889: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1890: return 0;
1891: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1892: }
1.222 markus 1893: if (len == 0)
1.205 djm 1894: return SSH_ERR_CONN_CLOSED;
1.201 markus 1895: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1896: return r;
1.14 markus 1897: }
1.205 djm 1898: return 0;
1.1 deraadt 1899: }
1900:
1.16 markus 1901: /*
1902: * Calls packet_write_poll repeatedly until all pending output data has been
1903: * written.
1904: */
1.205 djm 1905: int
1.201 markus 1906: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1907: {
1.56 millert 1908: fd_set *setp;
1.205 djm 1909: int ret, r, ms_remain = 0;
1.154 dtucker 1910: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1911: struct session_state *state = ssh->state;
1.56 millert 1912:
1.214 deraadt 1913: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1914: NFDBITS), sizeof(fd_mask));
1.201 markus 1915: if (setp == NULL)
1.205 djm 1916: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1917: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1918: free(setp);
1.215 djm 1919: return r;
1.216 gsoares 1920: }
1.201 markus 1921: while (ssh_packet_have_data_to_write(ssh)) {
1922: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1923: NFDBITS) * sizeof(fd_mask));
1.201 markus 1924: FD_SET(state->connection_out, setp);
1.154 dtucker 1925:
1.201 markus 1926: if (state->packet_timeout_ms > 0) {
1927: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1928: timeoutp = &timeout;
1929: }
1930: for (;;) {
1.201 markus 1931: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1932: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1933: monotime_tv(&start);
1.154 dtucker 1934: }
1.201 markus 1935: if ((ret = select(state->connection_out + 1,
1.161 andreas 1936: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1937: break;
1.161 andreas 1938: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1939: break;
1.201 markus 1940: if (state->packet_timeout_ms == -1)
1.154 dtucker 1941: continue;
1942: ms_subtract_diff(&start, &ms_remain);
1943: if (ms_remain <= 0) {
1944: ret = 0;
1945: break;
1946: }
1947: }
1948: if (ret == 0) {
1.205 djm 1949: free(setp);
1950: return SSH_ERR_CONN_TIMEOUT;
1951: }
1952: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1953: free(setp);
1954: return r;
1.154 dtucker 1955: }
1.14 markus 1956: }
1.186 djm 1957: free(setp);
1.205 djm 1958: return 0;
1.1 deraadt 1959: }
1960:
1961: /* Returns true if there is buffered data to write to the connection. */
1962:
1.2 provos 1963: int
1.201 markus 1964: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 1965: {
1.201 markus 1966: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 1967: }
1968:
1969: /* Returns true if there is not too much data to write to the connection. */
1970:
1.2 provos 1971: int
1.201 markus 1972: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 1973: {
1.201 markus 1974: if (ssh->state->interactive_mode)
1975: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 1976: else
1.201 markus 1977: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 1978: }
1979:
1.201 markus 1980: void
1981: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 1982: {
1.263 djm 1983: if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
1.101 markus 1984: return;
1.201 markus 1985: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 1986: case AF_INET:
1987: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 1988: if (setsockopt(ssh->state->connection_in,
1.173 djm 1989: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
1990: error("setsockopt IP_TOS %d: %.100s:",
1991: tos, strerror(errno));
1992: break;
1993: case AF_INET6:
1994: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 1995: if (setsockopt(ssh->state->connection_in,
1.173 djm 1996: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
1997: error("setsockopt IPV6_TCLASS %d: %.100s:",
1998: tos, strerror(errno));
1999: break;
2000: }
1.101 markus 2001: }
2002:
1.1 deraadt 2003: /* Informs that the current session is interactive. Sets IP flags for that. */
2004:
1.2 provos 2005: void
1.201 markus 2006: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2007: {
1.201 markus 2008: struct session_state *state = ssh->state;
2009:
2010: if (state->set_interactive_called)
1.43 markus 2011: return;
1.201 markus 2012: state->set_interactive_called = 1;
1.1 deraadt 2013:
1.14 markus 2014: /* Record that we are in interactive mode. */
1.201 markus 2015: state->interactive_mode = interactive;
1.1 deraadt 2016:
1.19 markus 2017: /* Only set socket options if using a socket. */
1.201 markus 2018: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2019: return;
1.201 markus 2020: set_nodelay(state->connection_in);
2021: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2022: qos_bulk);
1.1 deraadt 2023: }
2024:
2025: /* Returns true if the current connection is interactive. */
2026:
1.2 provos 2027: int
1.201 markus 2028: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2029: {
1.201 markus 2030: return ssh->state->interactive_mode;
1.12 markus 2031: }
2032:
1.113 deraadt 2033: int
1.201 markus 2034: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2035: {
1.201 markus 2036: struct session_state *state = ssh->state;
2037:
2038: if (state->set_maxsize_called) {
1.106 itojun 2039: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2040: state->max_packet_size, s);
1.14 markus 2041: return -1;
2042: }
2043: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2044: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2045: return -1;
2046: }
1.201 markus 2047: state->set_maxsize_called = 1;
1.66 markus 2048: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2049: state->max_packet_size = s;
1.14 markus 2050: return s;
1.53 markus 2051: }
2052:
1.161 andreas 2053: int
1.201 markus 2054: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2055: {
1.201 markus 2056: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2057: }
2058:
2059: void
1.201 markus 2060: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2061: {
1.201 markus 2062: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2063: }
2064:
2065: u_int
1.201 markus 2066: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2067: {
1.201 markus 2068: return ssh->state->max_packet_size;
1.71 markus 2069: }
2070:
1.105 markus 2071: void
1.244 dtucker 2072: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2073: {
1.244 dtucker 2074: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2075: (unsigned int)seconds);
1.201 markus 2076: ssh->state->rekey_limit = bytes;
2077: ssh->state->rekey_interval = seconds;
1.184 dtucker 2078: }
2079:
2080: time_t
1.201 markus 2081: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2082: {
2083: time_t seconds;
2084:
1.201 markus 2085: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2086: monotime();
1.185 dtucker 2087: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2088: }
2089:
2090: void
1.201 markus 2091: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2092: {
1.201 markus 2093: ssh->state->server_side = 1;
1.118 markus 2094: }
2095:
2096: void
1.201 markus 2097: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2098: {
1.201 markus 2099: ssh->state->after_authentication = 1;
1.161 andreas 2100: }
2101:
2102: void *
1.201 markus 2103: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2104: {
1.201 markus 2105: return (void *)ssh->state->input;
1.161 andreas 2106: }
2107:
2108: void *
1.201 markus 2109: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2110: {
1.201 markus 2111: return (void *)ssh->state->output;
1.166 andreas 2112: }
2113:
1.196 markus 2114: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2115: static int
2116: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2117: {
1.239 djm 2118: int r;
1.196 markus 2119:
2120: debug("%s: called", __func__);
2121: /* This was set in net child, but is not visible in user child */
1.201 markus 2122: ssh->state->after_authentication = 1;
2123: ssh->state->rekeying = 0;
1.239 djm 2124: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2125: return r;
1.201 markus 2126: return 0;
2127: }
2128:
2129: /* Packet state (de-)serialization for privsep */
2130:
2131: /* turn kex into a blob for packet state serialization */
2132: static int
2133: kex_to_blob(struct sshbuf *m, struct kex *kex)
2134: {
2135: int r;
2136:
2137: if ((r = sshbuf_put_string(m, kex->session_id,
2138: kex->session_id_len)) != 0 ||
2139: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
1.269 djm 2140: (r = sshbuf_put_cstring(m, kex->hostkey_alg)) != 0 ||
1.201 markus 2141: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
1.269 djm 2142: (r = sshbuf_put_u32(m, kex->hostkey_nid)) != 0 ||
1.201 markus 2143: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2144: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2145: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2146: (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2147: (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2148: (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2149: return r;
2150: return 0;
2151: }
2152:
2153: /* turn key exchange results into a blob for packet state serialization */
2154: static int
2155: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2156: {
2157: struct sshbuf *b;
2158: struct sshcipher_ctx *cc;
2159: struct sshcomp *comp;
2160: struct sshenc *enc;
2161: struct sshmac *mac;
2162: struct newkeys *newkey;
2163: int r;
2164:
2165: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2166: return SSH_ERR_INTERNAL_ERROR;
2167: enc = &newkey->enc;
2168: mac = &newkey->mac;
2169: comp = &newkey->comp;
1.235 djm 2170: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2171: ssh->state->receive_context;
1.201 markus 2172: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2173: return r;
2174: if ((b = sshbuf_new()) == NULL)
2175: return SSH_ERR_ALLOC_FAIL;
2176: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2177: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2178: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2179: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2180: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2181: goto out;
2182: if (cipher_authlen(enc->cipher) == 0) {
2183: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2184: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2185: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2186: goto out;
2187: }
2188: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2189: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2190: goto out;
2191: r = sshbuf_put_stringb(m, b);
2192: out:
1.221 mmcc 2193: sshbuf_free(b);
1.201 markus 2194: return r;
2195: }
2196:
2197: /* serialize packet state into a blob */
2198: int
2199: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2200: {
2201: struct session_state *state = ssh->state;
1.249 djm 2202: int r;
1.201 markus 2203:
1.249 djm 2204: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2205: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2206: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2207: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2208: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2209: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2210: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2211: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2212: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2213: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2214: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2215: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2216: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2217: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2218: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 2219: return r;
1.201 markus 2220:
2221: return 0;
2222: }
2223:
2224: /* restore key exchange results from blob for packet state de-serialization */
2225: static int
2226: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2227: {
2228: struct sshbuf *b = NULL;
2229: struct sshcomp *comp;
2230: struct sshenc *enc;
2231: struct sshmac *mac;
2232: struct newkeys *newkey = NULL;
2233: size_t keylen, ivlen, maclen;
2234: int r;
2235:
2236: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2237: r = SSH_ERR_ALLOC_FAIL;
2238: goto out;
2239: }
2240: if ((r = sshbuf_froms(m, &b)) != 0)
2241: goto out;
2242: #ifdef DEBUG_PK
2243: sshbuf_dump(b, stderr);
2244: #endif
2245: enc = &newkey->enc;
2246: mac = &newkey->mac;
2247: comp = &newkey->comp;
2248:
2249: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2250: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2251: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2252: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2253: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2254: goto out;
1.262 djm 2255: if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2256: r = SSH_ERR_INVALID_FORMAT;
2257: goto out;
2258: }
1.201 markus 2259: if (cipher_authlen(enc->cipher) == 0) {
2260: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2261: goto out;
2262: if ((r = mac_setup(mac, mac->name)) != 0)
2263: goto out;
2264: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2265: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2266: goto out;
2267: if (maclen > mac->key_len) {
2268: r = SSH_ERR_INVALID_FORMAT;
2269: goto out;
2270: }
2271: mac->key_len = maclen;
2272: }
2273: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2274: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2275: goto out;
2276: if (sshbuf_len(b) != 0) {
2277: r = SSH_ERR_INVALID_FORMAT;
2278: goto out;
2279: }
2280: enc->key_len = keylen;
2281: enc->iv_len = ivlen;
2282: ssh->kex->newkeys[mode] = newkey;
2283: newkey = NULL;
2284: r = 0;
2285: out:
1.219 mmcc 2286: free(newkey);
1.221 mmcc 2287: sshbuf_free(b);
1.201 markus 2288: return r;
2289: }
2290:
2291: /* restore kex from blob for packet state de-serialization */
2292: static int
2293: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2294: {
2295: struct kex *kex;
2296: int r;
2297:
2298: if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2299: (kex->my = sshbuf_new()) == NULL ||
2300: (kex->peer = sshbuf_new()) == NULL) {
2301: r = SSH_ERR_ALLOC_FAIL;
2302: goto out;
2303: }
2304: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2305: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
1.269 djm 2306: (r = sshbuf_get_cstring(m, &kex->hostkey_alg, NULL)) != 0 ||
1.201 markus 2307: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
1.269 djm 2308: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_nid)) != 0 ||
1.201 markus 2309: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2310: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2311: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2312: (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2313: (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2314: (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2315: goto out;
2316: kex->server = 1;
2317: kex->done = 1;
2318: r = 0;
2319: out:
2320: if (r != 0 || kexp == NULL) {
2321: if (kex != NULL) {
1.221 mmcc 2322: sshbuf_free(kex->my);
2323: sshbuf_free(kex->peer);
1.201 markus 2324: free(kex);
2325: }
2326: if (kexp != NULL)
2327: *kexp = NULL;
2328: } else {
2329: *kexp = kex;
2330: }
2331: return r;
2332: }
2333:
2334: /*
2335: * Restore packet state from content of blob 'm' (de-serialization).
2336: * Note that 'm' will be partially consumed on parsing or any other errors.
2337: */
2338: int
2339: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2340: {
2341: struct session_state *state = ssh->state;
1.254 djm 2342: const u_char *input, *output;
2343: size_t ilen, olen;
1.201 markus 2344: int r;
2345:
1.249 djm 2346: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2347: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2348: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2349: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2350: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2351: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2352: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2353: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2354: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2355: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2356: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2357: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2358: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2359: return r;
2360: /*
2361: * We set the time here so that in post-auth privsep slave we
2362: * count from the completion of the authentication.
2363: */
2364: state->rekey_time = monotime();
2365: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2366: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2367: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2368: return r;
1.201 markus 2369:
1.239 djm 2370: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2371: return r;
2372:
2373: sshbuf_reset(state->input);
2374: sshbuf_reset(state->output);
2375: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2376: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2377: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2378: (r = sshbuf_put(state->output, output, olen)) != 0)
2379: return r;
2380:
2381: if (sshbuf_len(m))
2382: return SSH_ERR_INVALID_FORMAT;
2383: debug3("%s: done", __func__);
2384: return 0;
2385: }
2386:
2387: /* NEW API */
2388:
2389: /* put data to the outgoing packet */
2390:
2391: int
2392: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2393: {
2394: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2395: }
2396:
2397: int
2398: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2399: {
2400: return sshbuf_putb(ssh->state->outgoing_packet, b);
2401: }
2402:
2403: int
2404: sshpkt_put_u8(struct ssh *ssh, u_char val)
2405: {
2406: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2407: }
2408:
2409: int
2410: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2411: {
2412: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2413: }
2414:
2415: int
2416: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2417: {
2418: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2419: }
2420:
2421: int
2422: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2423: {
2424: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2425: }
2426:
2427: int
2428: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2429: {
2430: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2431: }
2432:
2433: int
2434: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2435: {
2436: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2437: }
2438:
1.211 djm 2439: #ifdef WITH_OPENSSL
1.201 markus 2440: int
2441: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2442: {
2443: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2444: }
2445:
2446:
2447: int
2448: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2449: {
2450: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2451: }
1.211 djm 2452: #endif /* WITH_OPENSSL */
1.201 markus 2453:
2454: /* fetch data from the incoming packet */
2455:
2456: int
2457: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2458: {
2459: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2460: }
2461:
2462: int
2463: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2464: {
2465: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2466: }
2467:
2468: int
2469: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2470: {
2471: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2472: }
2473:
2474: int
2475: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2476: {
2477: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2478: }
2479:
2480: int
2481: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2482: {
2483: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2484: }
2485:
2486: int
2487: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2488: {
2489: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2490: }
2491:
2492: int
1.264 djm 2493: sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2494: {
2495: return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2496: }
2497:
2498: int
1.201 markus 2499: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2500: {
2501: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2502: }
2503:
1.211 djm 2504: #ifdef WITH_OPENSSL
1.201 markus 2505: int
2506: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2507: {
2508: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2509: }
2510:
2511:
2512: int
2513: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2514: {
2515: return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2516: }
1.211 djm 2517: #endif /* WITH_OPENSSL */
1.201 markus 2518:
2519: int
2520: sshpkt_get_end(struct ssh *ssh)
2521: {
2522: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2523: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2524: return 0;
2525: }
2526:
2527: const u_char *
2528: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2529: {
2530: if (lenp != NULL)
2531: *lenp = sshbuf_len(ssh->state->incoming_packet);
2532: return sshbuf_ptr(ssh->state->incoming_packet);
2533: }
2534:
2535: /* start a new packet */
2536:
2537: int
2538: sshpkt_start(struct ssh *ssh, u_char type)
2539: {
1.249 djm 2540: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2541:
2542: DBG(debug("packet_start[%d]", type));
1.249 djm 2543: memset(buf, 0, sizeof(buf));
2544: buf[sizeof(buf) - 1] = type;
1.201 markus 2545: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2546: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2547: }
2548:
1.242 markus 2549: static int
2550: ssh_packet_send_mux(struct ssh *ssh)
2551: {
2552: struct session_state *state = ssh->state;
2553: u_char type, *cp;
2554: size_t len;
2555: int r;
2556:
2557: if (ssh->kex)
2558: return SSH_ERR_INTERNAL_ERROR;
2559: len = sshbuf_len(state->outgoing_packet);
2560: if (len < 6)
2561: return SSH_ERR_INTERNAL_ERROR;
2562: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2563: type = cp[5];
2564: if (ssh_packet_log_type(type))
2565: debug3("%s: type %u", __func__, type);
2566: /* drop everything, but the connection protocol */
2567: if (type >= SSH2_MSG_CONNECTION_MIN &&
2568: type <= SSH2_MSG_CONNECTION_MAX) {
2569: POKE_U32(cp, len - 4);
2570: if ((r = sshbuf_putb(state->output,
2571: state->outgoing_packet)) != 0)
2572: return r;
2573: /* sshbuf_dump(state->output, stderr); */
2574: }
2575: sshbuf_reset(state->outgoing_packet);
1.264 djm 2576: return 0;
2577: }
2578:
2579: /*
2580: * 9.2. Ignored Data Message
2581: *
2582: * byte SSH_MSG_IGNORE
2583: * string data
2584: *
2585: * All implementations MUST understand (and ignore) this message at any
2586: * time (after receiving the protocol version). No implementation is
2587: * required to send them. This message can be used as an additional
2588: * protection measure against advanced traffic analysis techniques.
2589: */
2590: int
2591: sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2592: {
2593: u_int32_t rnd = 0;
2594: int r;
2595: u_int i;
2596:
2597: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2598: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2599: return r;
2600: for (i = 0; i < nbytes; i++) {
2601: if (i % 4 == 0)
2602: rnd = arc4random();
2603: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2604: return r;
2605: rnd >>= 8;
2606: }
1.242 markus 2607: return 0;
2608: }
2609:
1.201 markus 2610: /* send it */
2611:
2612: int
2613: sshpkt_send(struct ssh *ssh)
2614: {
1.242 markus 2615: if (ssh->state && ssh->state->mux)
2616: return ssh_packet_send_mux(ssh);
1.249 djm 2617: return ssh_packet_send2(ssh);
1.201 markus 2618: }
2619:
2620: int
2621: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2622: {
2623: char buf[1024];
2624: va_list args;
2625: int r;
2626:
2627: va_start(args, fmt);
2628: vsnprintf(buf, sizeof(buf), fmt, args);
2629: va_end(args);
2630:
1.249 djm 2631: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2632: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2633: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2634: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2635: (r = sshpkt_send(ssh)) != 0)
2636: return r;
1.201 markus 2637: return 0;
2638: }
2639:
2640: /* roundup current message to pad bytes */
2641: int
2642: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2643: {
2644: ssh->state->extra_pad = pad;
2645: return 0;
1.1 deraadt 2646: }
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