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