Annotation of src/usr.bin/ssh/packet.c, Revision 1.271
1.271 ! djm 1: /* $OpenBSD: packet.c,v 1.270 2018/05/25 03:20:59 dtucker Exp $ */
1.1 deraadt 2: /*
1.15 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.35 deraadt 6: * This file contains code implementing the packet protocol and communication
7: * with the other side. This same code is used both on client and server side.
1.29 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
1.29 markus 14: *
1.25 markus 15: *
16: * SSH2 packet format added by Markus Friedl.
1.69 markus 17: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.25 markus 18: *
1.35 deraadt 19: * Redistribution and use in source and binary forms, with or without
20: * modification, are permitted provided that the following conditions
21: * are met:
22: * 1. Redistributions of source code must retain the above copyright
23: * notice, this list of conditions and the following disclaimer.
24: * 2. Redistributions in binary form must reproduce the above copyright
25: * notice, this list of conditions and the following disclaimer in the
26: * documentation and/or other materials provided with the distribution.
27: *
28: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15 deraadt 38: */
1.1 deraadt 39:
1.142 deraadt 40: #include <sys/types.h>
1.105 markus 41: #include <sys/queue.h>
1.132 stevesk 42: #include <sys/socket.h>
1.138 stevesk 43: #include <sys/time.h>
1.132 stevesk 44: #include <netinet/in.h>
1.121 stevesk 45: #include <netinet/ip.h>
1.134 stevesk 46:
1.135 stevesk 47: #include <errno.h>
1.230 djm 48: #include <netdb.h>
1.134 stevesk 49: #include <stdarg.h>
1.141 stevesk 50: #include <stdio.h>
1.140 stevesk 51: #include <stdlib.h>
1.137 stevesk 52: #include <string.h>
1.136 stevesk 53: #include <unistd.h>
1.203 deraadt 54: #include <limits.h>
1.142 deraadt 55: #include <signal.h>
1.184 dtucker 56: #include <time.h>
1.1 deraadt 57:
1.201 markus 58: #include <zlib.h>
59:
60: #include "buffer.h" /* typedefs XXX */
61: #include "key.h" /* typedefs XXX */
62:
1.1 deraadt 63: #include "xmalloc.h"
64: #include "crc32.h"
1.25 markus 65: #include "compat.h"
66: #include "ssh2.h"
1.37 markus 67: #include "cipher.h"
1.201 markus 68: #include "sshkey.h"
1.25 markus 69: #include "kex.h"
1.200 markus 70: #include "digest.h"
1.50 markus 71: #include "mac.h"
1.46 markus 72: #include "log.h"
73: #include "canohost.h"
1.87 stevesk 74: #include "misc.h"
1.198 millert 75: #include "channels.h"
1.95 markus 76: #include "ssh.h"
1.201 markus 77: #include "packet.h"
1.197 djm 78: #include "ssherr.h"
1.201 markus 79: #include "sshbuf.h"
1.25 markus 80:
81: #ifdef PACKET_DEBUG
82: #define DBG(x) x
83: #else
84: #define DBG(x)
85: #endif
86:
1.159 markus 87: #define PACKET_MAX_SIZE (256 * 1024)
88:
1.161 andreas 89: struct packet_state {
90: u_int32_t seqnr;
91: u_int32_t packets;
92: u_int64_t blocks;
93: u_int64_t bytes;
94: };
95:
96: struct packet {
97: TAILQ_ENTRY(packet) next;
98: u_char type;
1.201 markus 99: struct sshbuf *payload;
1.161 andreas 100: };
101:
102: struct session_state {
103: /*
104: * This variable contains the file descriptors used for
105: * communicating with the other side. connection_in is used for
106: * reading; connection_out for writing. These can be the same
107: * descriptor, in which case it is assumed to be a socket.
108: */
109: int connection_in;
110: int connection_out;
111:
112: /* Protocol flags for the remote side. */
113: u_int remote_protocol_flags;
1.1 deraadt 114:
1.161 andreas 115: /* Encryption context for receiving data. Only used for decryption. */
1.235 djm 116: struct sshcipher_ctx *receive_context;
1.1 deraadt 117:
1.161 andreas 118: /* Encryption context for sending data. Only used for encryption. */
1.235 djm 119: struct sshcipher_ctx *send_context;
1.14 markus 120:
1.161 andreas 121: /* Buffer for raw input data from the socket. */
1.201 markus 122: struct sshbuf *input;
1.1 deraadt 123:
1.161 andreas 124: /* Buffer for raw output data going to the socket. */
1.201 markus 125: struct sshbuf *output;
1.1 deraadt 126:
1.161 andreas 127: /* Buffer for the partial outgoing packet being constructed. */
1.201 markus 128: struct sshbuf *outgoing_packet;
1.1 deraadt 129:
1.161 andreas 130: /* Buffer for the incoming packet currently being processed. */
1.201 markus 131: struct sshbuf *incoming_packet;
1.1 deraadt 132:
1.161 andreas 133: /* Scratch buffer for packet compression/decompression. */
1.201 markus 134: struct sshbuf *compression_buffer;
135:
136: /* Incoming/outgoing compression dictionaries */
137: z_stream compression_in_stream;
138: z_stream compression_out_stream;
139: int compression_in_started;
140: int compression_out_started;
141: int compression_in_failures;
142: int compression_out_failures;
1.1 deraadt 143:
1.161 andreas 144: /*
145: * Flag indicating whether packet compression/decompression is
146: * enabled.
147: */
148: int packet_compression;
1.1 deraadt 149:
1.161 andreas 150: /* default maximum packet size */
151: u_int max_packet_size;
1.1 deraadt 152:
1.161 andreas 153: /* Flag indicating whether this module has been initialized. */
154: int initialized;
1.12 markus 155:
1.161 andreas 156: /* Set to true if the connection is interactive. */
157: int interactive_mode;
1.1 deraadt 158:
1.161 andreas 159: /* Set to true if we are the server side. */
160: int server_side;
1.1 deraadt 161:
1.161 andreas 162: /* Set to true if we are authenticated. */
163: int after_authentication;
1.118 markus 164:
1.161 andreas 165: int keep_alive_timeouts;
1.118 markus 166:
1.161 andreas 167: /* The maximum time that we will wait to send or receive a packet */
168: int packet_timeout_ms;
1.151 dtucker 169:
1.161 andreas 170: /* Session key information for Encryption and MAC */
1.201 markus 171: struct newkeys *newkeys[MODE_MAX];
1.161 andreas 172: struct packet_state p_read, p_send;
1.154 dtucker 173:
1.184 dtucker 174: /* Volume-based rekeying */
1.224 dtucker 175: u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
1.105 markus 176:
1.184 dtucker 177: /* Time-based rekeying */
1.208 markus 178: u_int32_t rekey_interval; /* how often in seconds */
1.184 dtucker 179: time_t rekey_time; /* time of last rekeying */
180:
1.161 andreas 181: /* roundup current message to extra_pad bytes */
182: u_char extra_pad;
1.95 markus 183:
1.161 andreas 184: /* XXX discard incoming data after MAC error */
185: u_int packet_discard;
1.234 markus 186: size_t packet_discard_mac_already;
1.201 markus 187: struct sshmac *packet_discard_mac;
1.71 markus 188:
1.161 andreas 189: /* Used in packet_read_poll2() */
190: u_int packlen;
1.159 markus 191:
1.165 andreas 192: /* Used in packet_send2 */
193: int rekeying;
194:
1.242 markus 195: /* Used in ssh_packet_send_mux() */
196: int mux;
197:
1.165 andreas 198: /* Used in packet_set_interactive */
199: int set_interactive_called;
200:
201: /* Used in packet_set_maxsize */
202: int set_maxsize_called;
203:
1.201 markus 204: /* One-off warning about weak ciphers */
205: int cipher_warning_done;
206:
1.243 djm 207: /* Hook for fuzzing inbound packets */
208: ssh_packet_hook_fn *hook_in;
209: void *hook_in_ctx;
210:
1.161 andreas 211: TAILQ_HEAD(, packet) outgoing;
1.105 markus 212: };
1.161 andreas 213:
1.201 markus 214: struct ssh *
215: ssh_alloc_session_state(void)
1.161 andreas 216: {
1.201 markus 217: struct ssh *ssh = NULL;
218: struct session_state *state = NULL;
1.161 andreas 219:
1.201 markus 220: if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
221: (state = calloc(1, sizeof(*state))) == NULL ||
222: (state->input = sshbuf_new()) == NULL ||
223: (state->output = sshbuf_new()) == NULL ||
224: (state->outgoing_packet = sshbuf_new()) == NULL ||
225: (state->incoming_packet = sshbuf_new()) == NULL)
226: goto fail;
227: TAILQ_INIT(&state->outgoing);
1.202 markus 228: TAILQ_INIT(&ssh->private_keys);
229: TAILQ_INIT(&ssh->public_keys);
1.201 markus 230: state->connection_in = -1;
231: state->connection_out = -1;
232: state->max_packet_size = 32768;
233: state->packet_timeout_ms = -1;
234: state->p_send.packets = state->p_read.packets = 0;
235: state->initialized = 1;
236: /*
237: * ssh_packet_send2() needs to queue packets until
238: * we've done the initial key exchange.
239: */
240: state->rekeying = 1;
241: ssh->state = state;
242: return ssh;
243: fail:
244: if (state) {
245: sshbuf_free(state->input);
246: sshbuf_free(state->output);
247: sshbuf_free(state->incoming_packet);
248: sshbuf_free(state->outgoing_packet);
249: free(state);
250: }
251: free(ssh);
252: return NULL;
1.161 andreas 253: }
1.105 markus 254:
1.243 djm 255: void
256: ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
257: {
258: ssh->state->hook_in = hook;
259: ssh->state->hook_in_ctx = ctx;
260: }
261:
1.228 djm 262: /* Returns nonzero if rekeying is in progress */
263: int
264: ssh_packet_is_rekeying(struct ssh *ssh)
265: {
1.249 djm 266: return ssh->state->rekeying ||
267: (ssh->kex != NULL && ssh->kex->done == 0);
1.228 djm 268: }
269:
1.16 markus 270: /*
1.253 naddy 271: * Sets the descriptors used for communication.
1.16 markus 272: */
1.201 markus 273: struct ssh *
274: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1 deraadt 275: {
1.201 markus 276: struct session_state *state;
277: const struct sshcipher *none = cipher_by_name("none");
1.197 djm 278: int r;
1.97 deraadt 279:
1.205 djm 280: if (none == NULL) {
281: error("%s: cannot load cipher 'none'", __func__);
282: return NULL;
283: }
1.201 markus 284: if (ssh == NULL)
285: ssh = ssh_alloc_session_state();
1.205 djm 286: if (ssh == NULL) {
287: error("%s: cound not allocate state", __func__);
288: return NULL;
289: }
1.201 markus 290: state = ssh->state;
291: state->connection_in = fd_in;
292: state->connection_out = fd_out;
293: if ((r = cipher_init(&state->send_context, none,
1.197 djm 294: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201 markus 295: (r = cipher_init(&state->receive_context, none,
1.205 djm 296: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
297: error("%s: cipher_init failed: %s", __func__, ssh_err(r));
1.230 djm 298: free(ssh); /* XXX need ssh_free_session_state? */
1.205 djm 299: return NULL;
300: }
1.201 markus 301: state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
1.207 djm 302: /*
303: * Cache the IP address of the remote connection for use in error
304: * messages that might be generated after the connection has closed.
305: */
306: (void)ssh_remote_ipaddr(ssh);
1.201 markus 307: return ssh;
1.1 deraadt 308: }
309:
1.154 dtucker 310: void
1.201 markus 311: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 312: {
1.201 markus 313: struct session_state *state = ssh->state;
314:
1.174 djm 315: if (timeout <= 0 || count <= 0) {
1.201 markus 316: state->packet_timeout_ms = -1;
1.154 dtucker 317: return;
318: }
319: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 320: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 321: else
1.201 markus 322: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 323: }
324:
1.242 markus 325: void
326: ssh_packet_set_mux(struct ssh *ssh)
327: {
328: ssh->state->mux = 1;
329: ssh->state->rekeying = 0;
330: }
331:
332: int
333: ssh_packet_get_mux(struct ssh *ssh)
334: {
335: return ssh->state->mux;
336: }
337:
1.201 markus 338: int
1.245 djm 339: ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
340: {
341: va_list args;
342: int r;
343:
344: free(ssh->log_preamble);
345: if (fmt == NULL)
346: ssh->log_preamble = NULL;
347: else {
348: va_start(args, fmt);
349: r = vasprintf(&ssh->log_preamble, fmt, args);
350: va_end(args);
351: if (r < 0 || ssh->log_preamble == NULL)
352: return SSH_ERR_ALLOC_FAIL;
353: }
354: return 0;
355: }
356:
357: int
1.201 markus 358: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 359: {
1.201 markus 360: struct session_state *state = ssh->state;
361: int r;
362:
363: if (state->packet_discard_mac) {
1.159 markus 364: char buf[1024];
1.234 markus 365: size_t dlen = PACKET_MAX_SIZE;
1.201 markus 366:
1.234 markus 367: if (dlen > state->packet_discard_mac_already)
368: dlen -= state->packet_discard_mac_already;
1.159 markus 369: memset(buf, 'a', sizeof(buf));
1.234 markus 370: while (sshbuf_len(state->incoming_packet) < dlen)
1.201 markus 371: if ((r = sshbuf_put(state->incoming_packet, buf,
372: sizeof(buf))) != 0)
373: return r;
374: (void) mac_compute(state->packet_discard_mac,
375: state->p_read.seqnr,
1.234 markus 376: sshbuf_ptr(state->incoming_packet), dlen,
1.201 markus 377: NULL, 0);
1.159 markus 378: }
1.220 djm 379: logit("Finished discarding for %.200s port %d",
380: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 381: return SSH_ERR_MAC_INVALID;
1.159 markus 382: }
383:
1.201 markus 384: static int
385: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
1.234 markus 386: struct sshmac *mac, size_t mac_already, u_int discard)
1.159 markus 387: {
1.201 markus 388: struct session_state *state = ssh->state;
389: int r;
390:
391: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
392: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
393: return r;
394: return SSH_ERR_MAC_INVALID;
395: }
1.234 markus 396: /*
397: * Record number of bytes over which the mac has already
398: * been computed in order to minimize timing attacks.
399: */
400: if (mac && mac->enabled) {
1.201 markus 401: state->packet_discard_mac = mac;
1.234 markus 402: state->packet_discard_mac_already = mac_already;
403: }
404: if (sshbuf_len(state->input) >= discard)
405: return ssh_packet_stop_discard(ssh);
1.201 markus 406: state->packet_discard = discard - sshbuf_len(state->input);
407: return 0;
1.159 markus 408: }
409:
1.19 markus 410: /* Returns 1 if remote host is connected via socket, 0 if not. */
411:
412: int
1.201 markus 413: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 414: {
1.271 ! djm 415: struct session_state *state;
1.19 markus 416: struct sockaddr_storage from, to;
417: socklen_t fromlen, tolen;
418:
1.271 ! djm 419: if (ssh == NULL || ssh->state == NULL)
! 420: return 0;
! 421:
! 422: state = ssh->state;
1.230 djm 423: if (state->connection_in == -1 || state->connection_out == -1)
424: return 0;
1.19 markus 425: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 426: if (state->connection_in == state->connection_out)
1.19 markus 427: return 1;
428: fromlen = sizeof(from);
429: memset(&from, 0, sizeof(from));
1.201 markus 430: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.161 andreas 431: &fromlen) < 0)
1.19 markus 432: return 0;
433: tolen = sizeof(to);
434: memset(&to, 0, sizeof(to));
1.201 markus 435: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.161 andreas 436: &tolen) < 0)
1.19 markus 437: return 0;
438: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
439: return 0;
440: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
441: return 0;
442: return 1;
443: }
444:
1.91 markus 445: void
1.201 markus 446: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 447: {
1.201 markus 448: if (ibytes)
449: *ibytes = ssh->state->p_read.bytes;
450: if (obytes)
451: *obytes = ssh->state->p_send.bytes;
1.91 markus 452: }
1.125 deraadt 453:
1.91 markus 454: int
1.201 markus 455: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 456: {
457: struct sockaddr_storage to;
1.21 deraadt 458: socklen_t tolen = sizeof(to);
1.19 markus 459:
460: memset(&to, 0, sizeof(to));
1.201 markus 461: if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
1.161 andreas 462: &tolen) < 0)
1.19 markus 463: return 0;
1.173 djm 464: return to.ss_family;
1.19 markus 465: }
466:
1.1 deraadt 467: /* Sets the connection into non-blocking mode. */
468:
1.2 provos 469: void
1.201 markus 470: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 471: {
1.14 markus 472: /* Set the socket into non-blocking mode. */
1.201 markus 473: set_nonblock(ssh->state->connection_in);
1.14 markus 474:
1.201 markus 475: if (ssh->state->connection_out != ssh->state->connection_in)
476: set_nonblock(ssh->state->connection_out);
1.1 deraadt 477: }
478:
479: /* Returns the socket used for reading. */
480:
1.2 provos 481: int
1.201 markus 482: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 483: {
1.201 markus 484: return ssh->state->connection_in;
1.1 deraadt 485: }
486:
487: /* Returns the descriptor used for writing. */
488:
1.2 provos 489: int
1.201 markus 490: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 491: {
1.201 markus 492: return ssh->state->connection_out;
493: }
494:
495: /*
496: * Returns the IP-address of the remote host as a string. The returned
497: * string must not be freed.
498: */
499:
500: const char *
501: ssh_remote_ipaddr(struct ssh *ssh)
502: {
1.271 ! djm 503: int sock;
1.220 djm 504:
1.201 markus 505: /* Check whether we have cached the ipaddr. */
1.220 djm 506: if (ssh->remote_ipaddr == NULL) {
507: if (ssh_packet_connection_is_on_socket(ssh)) {
1.271 ! djm 508: sock = ssh->state->connection_in;
1.220 djm 509: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 djm 510: ssh->remote_port = get_peer_port(sock);
511: ssh->local_ipaddr = get_local_ipaddr(sock);
512: ssh->local_port = get_local_port(sock);
1.220 djm 513: } else {
514: ssh->remote_ipaddr = strdup("UNKNOWN");
1.230 djm 515: ssh->remote_port = 65535;
516: ssh->local_ipaddr = strdup("UNKNOWN");
517: ssh->local_port = 65535;
1.220 djm 518: }
519: }
1.201 markus 520: return ssh->remote_ipaddr;
1.1 deraadt 521: }
522:
1.220 djm 523: /* Returns the port number of the remote host. */
524:
525: int
526: ssh_remote_port(struct ssh *ssh)
527: {
528: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
529: return ssh->remote_port;
1.230 djm 530: }
531:
532: /*
533: * Returns the IP-address of the local host as a string. The returned
534: * string must not be freed.
535: */
536:
537: const char *
538: ssh_local_ipaddr(struct ssh *ssh)
539: {
540: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
541: return ssh->local_ipaddr;
542: }
543:
544: /* Returns the port number of the local host. */
545:
546: int
547: ssh_local_port(struct ssh *ssh)
548: {
549: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
550: return ssh->local_port;
1.266 djm 551: }
552:
553: /* Returns the routing domain of the input socket, or NULL if unavailable */
554: const char *
555: ssh_packet_rdomain_in(struct ssh *ssh)
556: {
557: if (ssh->rdomain_in != NULL)
558: return ssh->rdomain_in;
559: if (!ssh_packet_connection_is_on_socket(ssh))
560: return NULL;
561: ssh->rdomain_in = get_rdomain(ssh->state->connection_in);
562: return ssh->rdomain_in;
1.220 djm 563: }
564:
1.1 deraadt 565: /* Closes the connection and clears and frees internal data structures. */
566:
1.257 markus 567: static void
568: ssh_packet_close_internal(struct ssh *ssh, int do_close)
1.1 deraadt 569: {
1.201 markus 570: struct session_state *state = ssh->state;
571: u_int mode;
572:
573: if (!state->initialized)
1.14 markus 574: return;
1.201 markus 575: state->initialized = 0;
1.257 markus 576: if (do_close) {
577: if (state->connection_in == state->connection_out) {
578: close(state->connection_out);
579: } else {
580: close(state->connection_in);
581: close(state->connection_out);
582: }
1.14 markus 583: }
1.201 markus 584: sshbuf_free(state->input);
585: sshbuf_free(state->output);
586: sshbuf_free(state->outgoing_packet);
587: sshbuf_free(state->incoming_packet);
1.257 markus 588: for (mode = 0; mode < MODE_MAX; mode++) {
589: kex_free_newkeys(state->newkeys[mode]); /* current keys */
590: state->newkeys[mode] = NULL;
591: ssh_clear_newkeys(ssh, mode); /* next keys */
592: }
593: /* comression state is in shared mem, so we can only release it once */
594: if (do_close && state->compression_buffer) {
1.201 markus 595: sshbuf_free(state->compression_buffer);
596: if (state->compression_out_started) {
597: z_streamp stream = &state->compression_out_stream;
598: debug("compress outgoing: "
599: "raw data %llu, compressed %llu, factor %.2f",
600: (unsigned long long)stream->total_in,
601: (unsigned long long)stream->total_out,
602: stream->total_in == 0 ? 0.0 :
603: (double) stream->total_out / stream->total_in);
604: if (state->compression_out_failures == 0)
605: deflateEnd(stream);
606: }
607: if (state->compression_in_started) {
1.260 dtucker 608: z_streamp stream = &state->compression_in_stream;
1.201 markus 609: debug("compress incoming: "
610: "raw data %llu, compressed %llu, factor %.2f",
611: (unsigned long long)stream->total_out,
612: (unsigned long long)stream->total_in,
613: stream->total_out == 0 ? 0.0 :
614: (double) stream->total_in / stream->total_out);
615: if (state->compression_in_failures == 0)
616: inflateEnd(stream);
617: }
1.14 markus 618: }
1.235 djm 619: cipher_free(state->send_context);
620: cipher_free(state->receive_context);
621: state->send_context = state->receive_context = NULL;
1.257 markus 622: if (do_close) {
623: free(ssh->remote_ipaddr);
624: ssh->remote_ipaddr = NULL;
625: free(ssh->state);
626: ssh->state = NULL;
627: }
628: }
629:
630: void
631: ssh_packet_close(struct ssh *ssh)
632: {
633: ssh_packet_close_internal(ssh, 1);
634: }
635:
636: void
637: ssh_packet_clear_keys(struct ssh *ssh)
638: {
639: ssh_packet_close_internal(ssh, 0);
1.1 deraadt 640: }
641:
642: /* Sets remote side protocol flags. */
643:
1.2 provos 644: void
1.201 markus 645: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 646: {
1.201 markus 647: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 648: }
649:
650: /* Returns the remote protocol flags set earlier by the above function. */
651:
1.40 markus 652: u_int
1.201 markus 653: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 654: {
1.201 markus 655: return ssh->state->remote_protocol_flags;
1.1 deraadt 656: }
657:
1.16 markus 658: /*
659: * Starts packet compression from the next packet on in both directions.
660: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
661: */
1.1 deraadt 662:
1.201 markus 663: static int
664: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 665: {
1.201 markus 666: if (!ssh->state->compression_buffer &&
667: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
668: return SSH_ERR_ALLOC_FAIL;
669: return 0;
1.60 markus 670: }
671:
1.201 markus 672: static int
673: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 674: {
1.201 markus 675: if (level < 1 || level > 9)
676: return SSH_ERR_INVALID_ARGUMENT;
677: debug("Enabling compression at level %d.", level);
678: if (ssh->state->compression_out_started == 1)
679: deflateEnd(&ssh->state->compression_out_stream);
680: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
681: case Z_OK:
682: ssh->state->compression_out_started = 1;
683: break;
684: case Z_MEM_ERROR:
685: return SSH_ERR_ALLOC_FAIL;
686: default:
687: return SSH_ERR_INTERNAL_ERROR;
688: }
689: return 0;
1.1 deraadt 690: }
691:
1.201 markus 692: static int
693: start_compression_in(struct ssh *ssh)
694: {
695: if (ssh->state->compression_in_started == 1)
696: inflateEnd(&ssh->state->compression_in_stream);
697: switch (inflateInit(&ssh->state->compression_in_stream)) {
698: case Z_OK:
699: ssh->state->compression_in_started = 1;
700: break;
701: case Z_MEM_ERROR:
702: return SSH_ERR_ALLOC_FAIL;
703: default:
704: return SSH_ERR_INTERNAL_ERROR;
705: }
706: return 0;
707: }
1.95 markus 708:
1.201 markus 709: int
710: ssh_packet_start_compression(struct ssh *ssh, int level)
1.1 deraadt 711: {
1.197 djm 712: int r;
1.97 deraadt 713:
1.249 djm 714: if (ssh->state->packet_compression)
1.201 markus 715: return SSH_ERR_INTERNAL_ERROR;
716: ssh->state->packet_compression = 1;
717: if ((r = ssh_packet_init_compression(ssh)) != 0 ||
718: (r = start_compression_in(ssh)) != 0 ||
719: (r = start_compression_out(ssh, level)) != 0)
720: return r;
721: return 0;
1.95 markus 722: }
723:
1.201 markus 724: /* XXX remove need for separate compression buffer */
725: static int
726: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 727: {
1.201 markus 728: u_char buf[4096];
729: int r, status;
730:
731: if (ssh->state->compression_out_started != 1)
732: return SSH_ERR_INTERNAL_ERROR;
733:
734: /* This case is not handled below. */
735: if (sshbuf_len(in) == 0)
736: return 0;
737:
738: /* Input is the contents of the input buffer. */
739: if ((ssh->state->compression_out_stream.next_in =
740: sshbuf_mutable_ptr(in)) == NULL)
741: return SSH_ERR_INTERNAL_ERROR;
742: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
743:
744: /* Loop compressing until deflate() returns with avail_out != 0. */
745: do {
746: /* Set up fixed-size output buffer. */
747: ssh->state->compression_out_stream.next_out = buf;
748: ssh->state->compression_out_stream.avail_out = sizeof(buf);
749:
750: /* Compress as much data into the buffer as possible. */
751: status = deflate(&ssh->state->compression_out_stream,
752: Z_PARTIAL_FLUSH);
753: switch (status) {
754: case Z_MEM_ERROR:
755: return SSH_ERR_ALLOC_FAIL;
756: case Z_OK:
757: /* Append compressed data to output_buffer. */
758: if ((r = sshbuf_put(out, buf, sizeof(buf) -
759: ssh->state->compression_out_stream.avail_out)) != 0)
760: return r;
761: break;
762: case Z_STREAM_ERROR:
763: default:
764: ssh->state->compression_out_failures++;
765: return SSH_ERR_INVALID_FORMAT;
766: }
767: } while (ssh->state->compression_out_stream.avail_out == 0);
768: return 0;
1.1 deraadt 769: }
770:
1.201 markus 771: static int
772: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 773: {
1.201 markus 774: u_char buf[4096];
775: int r, status;
1.1 deraadt 776:
1.201 markus 777: if (ssh->state->compression_in_started != 1)
778: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 779:
1.201 markus 780: if ((ssh->state->compression_in_stream.next_in =
781: sshbuf_mutable_ptr(in)) == NULL)
782: return SSH_ERR_INTERNAL_ERROR;
783: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 784:
1.201 markus 785: for (;;) {
786: /* Set up fixed-size output buffer. */
787: ssh->state->compression_in_stream.next_out = buf;
788: ssh->state->compression_in_stream.avail_out = sizeof(buf);
789:
790: status = inflate(&ssh->state->compression_in_stream,
791: Z_PARTIAL_FLUSH);
792: switch (status) {
793: case Z_OK:
794: if ((r = sshbuf_put(out, buf, sizeof(buf) -
795: ssh->state->compression_in_stream.avail_out)) != 0)
796: return r;
797: break;
798: case Z_BUF_ERROR:
799: /*
800: * Comments in zlib.h say that we should keep calling
801: * inflate() until we get an error. This appears to
802: * be the error that we get.
803: */
804: return 0;
805: case Z_DATA_ERROR:
806: return SSH_ERR_INVALID_FORMAT;
807: case Z_MEM_ERROR:
808: return SSH_ERR_ALLOC_FAIL;
809: case Z_STREAM_ERROR:
810: default:
811: ssh->state->compression_in_failures++;
812: return SSH_ERR_INTERNAL_ERROR;
813: }
814: }
815: /* NOTREACHED */
1.170 djm 816: }
817:
1.257 markus 818: void
819: ssh_clear_newkeys(struct ssh *ssh, int mode)
820: {
1.259 djm 821: if (ssh->kex && ssh->kex->newkeys[mode]) {
1.257 markus 822: kex_free_newkeys(ssh->kex->newkeys[mode]);
823: ssh->kex->newkeys[mode] = NULL;
824: }
825: }
826:
1.201 markus 827: int
828: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 829: {
1.201 markus 830: struct session_state *state = ssh->state;
831: struct sshenc *enc;
832: struct sshmac *mac;
833: struct sshcomp *comp;
1.235 djm 834: struct sshcipher_ctx **ccp;
1.236 markus 835: struct packet_state *ps;
1.105 markus 836: u_int64_t *max_blocks;
1.259 djm 837: const char *wmsg;
1.197 djm 838: int r, crypt_type;
1.57 markus 839:
1.100 markus 840: debug2("set_newkeys: mode %d", mode);
1.57 markus 841:
1.88 markus 842: if (mode == MODE_OUT) {
1.235 djm 843: ccp = &state->send_context;
1.115 avsm 844: crypt_type = CIPHER_ENCRYPT;
1.236 markus 845: ps = &state->p_send;
1.201 markus 846: max_blocks = &state->max_blocks_out;
1.88 markus 847: } else {
1.235 djm 848: ccp = &state->receive_context;
1.115 avsm 849: crypt_type = CIPHER_DECRYPT;
1.236 markus 850: ps = &state->p_read;
1.201 markus 851: max_blocks = &state->max_blocks_in;
1.88 markus 852: }
1.201 markus 853: if (state->newkeys[mode] != NULL) {
1.257 markus 854: debug("set_newkeys: rekeying, input %llu bytes %llu blocks, "
855: "output %llu bytes %llu blocks",
856: (unsigned long long)state->p_read.bytes,
857: (unsigned long long)state->p_read.blocks,
858: (unsigned long long)state->p_send.bytes,
859: (unsigned long long)state->p_send.blocks);
1.235 djm 860: cipher_free(*ccp);
861: *ccp = NULL;
1.257 markus 862: kex_free_newkeys(state->newkeys[mode]);
863: state->newkeys[mode] = NULL;
1.57 markus 864: }
1.236 markus 865: /* note that both bytes and the seqnr are not reset */
866: ps->packets = ps->blocks = 0;
1.201 markus 867: /* move newkeys from kex to state */
868: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
869: return SSH_ERR_INTERNAL_ERROR;
870: ssh->kex->newkeys[mode] = NULL;
871: enc = &state->newkeys[mode]->enc;
872: mac = &state->newkeys[mode]->mac;
873: comp = &state->newkeys[mode]->comp;
874: if (cipher_authlen(enc->cipher) == 0) {
875: if ((r = mac_init(mac)) != 0)
876: return r;
877: }
878: mac->enabled = 1;
1.57 markus 879: DBG(debug("cipher_init_context: %d", mode));
1.235 djm 880: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 881: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 882: return r;
883: if (!state->cipher_warning_done &&
1.235 djm 884: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 885: error("Warning: %s", wmsg);
886: state->cipher_warning_done = 1;
887: }
1.91 markus 888: /* Deleting the keys does not gain extra security */
1.192 djm 889: /* explicit_bzero(enc->iv, enc->block_size);
890: explicit_bzero(enc->key, enc->key_len);
891: explicit_bzero(mac->key, mac->key_len); */
1.241 djm 892: if ((comp->type == COMP_ZLIB ||
893: (comp->type == COMP_DELAYED &&
894: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 895: if ((r = ssh_packet_init_compression(ssh)) < 0)
896: return r;
897: if (mode == MODE_OUT) {
898: if ((r = start_compression_out(ssh, 6)) != 0)
899: return r;
900: } else {
901: if ((r = start_compression_in(ssh)) != 0)
902: return r;
903: }
1.57 markus 904: comp->enabled = 1;
905: }
1.109 markus 906: /*
907: * The 2^(blocksize*2) limit is too expensive for 3DES,
1.254 djm 908: * so enforce a 1GB limit for small blocksizes.
1.261 dtucker 909: * See RFC4344 section 3.2.
1.109 markus 910: */
911: if (enc->block_size >= 16)
912: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
913: else
914: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 915: if (state->rekey_limit)
1.237 deraadt 916: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 917: state->rekey_limit / enc->block_size);
1.227 djm 918: debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1.201 markus 919: return 0;
1.57 markus 920: }
921:
1.228 djm 922: #define MAX_PACKETS (1U<<31)
923: static int
924: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
925: {
926: struct session_state *state = ssh->state;
927: u_int32_t out_blocks;
928:
929: /* XXX client can't cope with rekeying pre-auth */
930: if (!state->after_authentication)
931: return 0;
932:
933: /* Haven't keyed yet or KEX in progress. */
934: if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
935: return 0;
936:
937: /* Peer can't rekey */
938: if (ssh->compat & SSH_BUG_NOREKEY)
939: return 0;
940:
941: /*
942: * Permit one packet in or out per rekey - this allows us to
943: * make progress when rekey limits are very small.
944: */
945: if (state->p_send.packets == 0 && state->p_read.packets == 0)
946: return 0;
947:
948: /* Time-based rekeying */
949: if (state->rekey_interval != 0 &&
1.244 dtucker 950: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 951: return 1;
952:
1.261 dtucker 953: /*
954: * Always rekey when MAX_PACKETS sent in either direction
955: * As per RFC4344 section 3.1 we do this after 2^31 packets.
956: */
1.228 djm 957: if (state->p_send.packets > MAX_PACKETS ||
958: state->p_read.packets > MAX_PACKETS)
959: return 1;
960:
961: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 962: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 963: state->newkeys[MODE_OUT]->enc.block_size);
964: return (state->max_blocks_out &&
965: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
966: (state->max_blocks_in &&
967: (state->p_read.blocks > state->max_blocks_in));
968: }
969:
1.16 markus 970: /*
1.118 markus 971: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 972: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 973: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
974: */
1.201 markus 975: static int
976: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 977: {
1.201 markus 978: struct session_state *state = ssh->state;
979: struct sshcomp *comp = NULL;
980: int r, mode;
1.118 markus 981:
982: /*
983: * Remember that we are past the authentication step, so rekeying
984: * with COMP_DELAYED will turn on compression immediately.
985: */
1.201 markus 986: state->after_authentication = 1;
1.118 markus 987: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 988: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 989: if (state->newkeys[mode] == NULL)
1.145 markus 990: continue;
1.201 markus 991: comp = &state->newkeys[mode]->comp;
1.118 markus 992: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 993: if ((r = ssh_packet_init_compression(ssh)) != 0)
994: return r;
995: if (mode == MODE_OUT) {
996: if ((r = start_compression_out(ssh, 6)) != 0)
997: return r;
998: } else {
999: if ((r = start_compression_in(ssh)) != 0)
1000: return r;
1001: }
1.118 markus 1002: comp->enabled = 1;
1003: }
1004: }
1.201 markus 1005: return 0;
1.118 markus 1006: }
1007:
1.226 djm 1008: /* Used to mute debug logging for noisy packet types */
1.242 markus 1009: int
1.226 djm 1010: ssh_packet_log_type(u_char type)
1011: {
1012: switch (type) {
1013: case SSH2_MSG_CHANNEL_DATA:
1014: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1015: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1016: return 0;
1017: default:
1018: return 1;
1019: }
1020: }
1021:
1.118 markus 1022: /*
1.25 markus 1023: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1024: */
1.201 markus 1025: int
1026: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1027: {
1.201 markus 1028: struct session_state *state = ssh->state;
1.200 markus 1029: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1030: u_char tmp, padlen, pad = 0;
1.201 markus 1031: u_int authlen = 0, aadlen = 0;
1032: u_int len;
1033: struct sshenc *enc = NULL;
1034: struct sshmac *mac = NULL;
1035: struct sshcomp *comp = NULL;
1036: int r, block_size;
1037:
1038: if (state->newkeys[MODE_OUT] != NULL) {
1039: enc = &state->newkeys[MODE_OUT]->enc;
1040: mac = &state->newkeys[MODE_OUT]->mac;
1041: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1042: /* disable mac for authenticated encryption */
1043: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1044: mac = NULL;
1.25 markus 1045: }
1.88 markus 1046: block_size = enc ? enc->block_size : 8;
1.180 markus 1047: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1048:
1.201 markus 1049: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1050: if (ssh_packet_log_type(type))
1051: debug3("send packet: type %u", type);
1.25 markus 1052: #ifdef PACKET_DEBUG
1053: fprintf(stderr, "plain: ");
1.201 markus 1054: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1055: #endif
1056:
1057: if (comp && comp->enabled) {
1.201 markus 1058: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1059: /* skip header, compress only payload */
1.201 markus 1060: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1061: goto out;
1062: sshbuf_reset(state->compression_buffer);
1063: if ((r = compress_buffer(ssh, state->outgoing_packet,
1064: state->compression_buffer)) != 0)
1065: goto out;
1066: sshbuf_reset(state->outgoing_packet);
1067: if ((r = sshbuf_put(state->outgoing_packet,
1068: "\0\0\0\0\0", 5)) != 0 ||
1069: (r = sshbuf_putb(state->outgoing_packet,
1070: state->compression_buffer)) != 0)
1071: goto out;
1072: DBG(debug("compression: raw %d compressed %zd", len,
1073: sshbuf_len(state->outgoing_packet)));
1.25 markus 1074: }
1075:
1076: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1077: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1078:
1079: /*
1080: * calc size of padding, alloc space, get random data,
1081: * minimum padding is 4 bytes
1082: */
1.178 markus 1083: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1084: padlen = block_size - (len % block_size);
1085: if (padlen < 4)
1086: padlen += block_size;
1.201 markus 1087: if (state->extra_pad) {
1.233 djm 1088: tmp = state->extra_pad;
1.201 markus 1089: state->extra_pad =
1.237 deraadt 1090: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1091: /* check if roundup overflowed */
1092: if (state->extra_pad < tmp)
1093: return SSH_ERR_INVALID_ARGUMENT;
1094: tmp = (len + padlen) % state->extra_pad;
1095: /* Check whether pad calculation below will underflow */
1096: if (tmp > state->extra_pad)
1097: return SSH_ERR_INVALID_ARGUMENT;
1098: pad = state->extra_pad - tmp;
1.193 djm 1099: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1100: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1101: tmp = padlen;
1.71 markus 1102: padlen += pad;
1.233 djm 1103: /* Check whether padlen calculation overflowed */
1104: if (padlen < tmp)
1105: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1106: state->extra_pad = 0;
1.71 markus 1107: }
1.201 markus 1108: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1109: goto out;
1.235 djm 1110: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1111: /* random padding */
1.201 markus 1112: arc4random_buf(cp, padlen);
1.32 markus 1113: } else {
1114: /* clear padding */
1.192 djm 1115: explicit_bzero(cp, padlen);
1.25 markus 1116: }
1.178 markus 1117: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1118: len = sshbuf_len(state->outgoing_packet);
1119: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1120: if (cp == NULL) {
1121: r = SSH_ERR_INTERNAL_ERROR;
1122: goto out;
1123: }
1.25 markus 1124: /* packet_length includes payload, padding and padding length field */
1.201 markus 1125: POKE_U32(cp, len - 4);
1.89 markus 1126: cp[4] = padlen;
1.178 markus 1127: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1128: len, padlen, aadlen));
1.25 markus 1129:
1130: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1131: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1132: if ((r = mac_compute(mac, state->p_send.seqnr,
1133: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1134: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1135: goto out;
1136: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1137: }
1138: /* encrypt packet and append to output buffer. */
1.201 markus 1139: if ((r = sshbuf_reserve(state->output,
1140: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1141: goto out;
1.235 djm 1142: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1143: sshbuf_ptr(state->outgoing_packet),
1144: len - aadlen, aadlen, authlen)) != 0)
1145: goto out;
1.25 markus 1146: /* append unencrypted MAC */
1.178 markus 1147: if (mac && mac->enabled) {
1148: if (mac->etm) {
1149: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1150: if ((r = mac_compute(mac, state->p_send.seqnr,
1151: cp, len, macbuf, sizeof(macbuf))) != 0)
1152: goto out;
1.178 markus 1153: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1154: state->p_send.seqnr));
1.178 markus 1155: }
1.201 markus 1156: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1157: goto out;
1.178 markus 1158: }
1.25 markus 1159: #ifdef PACKET_DEBUG
1160: fprintf(stderr, "encrypted: ");
1.201 markus 1161: sshbuf_dump(state->output, stderr);
1.25 markus 1162: #endif
1.29 markus 1163: /* increment sequence number for outgoing packets */
1.201 markus 1164: if (++state->p_send.seqnr == 0)
1.106 itojun 1165: logit("outgoing seqnr wraps around");
1.201 markus 1166: if (++state->p_send.packets == 0)
1167: if (!(ssh->compat & SSH_BUG_NOREKEY))
1168: return SSH_ERR_NEED_REKEY;
1169: state->p_send.blocks += len / block_size;
1170: state->p_send.bytes += len;
1171: sshbuf_reset(state->outgoing_packet);
1.25 markus 1172:
1.57 markus 1173: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1174: r = ssh_set_newkeys(ssh, MODE_OUT);
1175: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1176: r = ssh_packet_enable_delayed_compress(ssh);
1177: else
1178: r = 0;
1179: out:
1180: return r;
1.25 markus 1181: }
1182:
1.228 djm 1183: /* returns non-zero if the specified packet type is usec by KEX */
1184: static int
1185: ssh_packet_type_is_kex(u_char type)
1186: {
1187: return
1188: type >= SSH2_MSG_TRANSPORT_MIN &&
1189: type <= SSH2_MSG_TRANSPORT_MAX &&
1190: type != SSH2_MSG_SERVICE_REQUEST &&
1191: type != SSH2_MSG_SERVICE_ACCEPT &&
1192: type != SSH2_MSG_EXT_INFO;
1193: }
1194:
1.201 markus 1195: int
1196: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1197: {
1.201 markus 1198: struct session_state *state = ssh->state;
1.105 markus 1199: struct packet *p;
1.201 markus 1200: u_char type;
1.228 djm 1201: int r, need_rekey;
1.105 markus 1202:
1.228 djm 1203: if (sshbuf_len(state->outgoing_packet) < 6)
1204: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1205: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1206: need_rekey = !ssh_packet_type_is_kex(type) &&
1207: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1208:
1.228 djm 1209: /*
1210: * During rekeying we can only send key exchange messages.
1211: * Queue everything else.
1212: */
1213: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1214: if (need_rekey)
1215: debug3("%s: rekex triggered", __func__);
1216: debug("enqueue packet: %u", type);
1217: p = calloc(1, sizeof(*p));
1218: if (p == NULL)
1219: return SSH_ERR_ALLOC_FAIL;
1220: p->type = type;
1221: p->payload = state->outgoing_packet;
1222: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1223: state->outgoing_packet = sshbuf_new();
1224: if (state->outgoing_packet == NULL)
1225: return SSH_ERR_ALLOC_FAIL;
1226: if (need_rekey) {
1227: /*
1228: * This packet triggered a rekey, so send the
1229: * KEXINIT now.
1230: * NB. reenters this function via kex_start_rekex().
1231: */
1232: return kex_start_rekex(ssh);
1.105 markus 1233: }
1.228 djm 1234: return 0;
1.105 markus 1235: }
1236:
1237: /* rekeying starts with sending KEXINIT */
1238: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1239: state->rekeying = 1;
1.105 markus 1240:
1.201 markus 1241: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1242: return r;
1.105 markus 1243:
1244: /* after a NEWKEYS message we can send the complete queue */
1245: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1246: state->rekeying = 0;
1247: state->rekey_time = monotime();
1248: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1249: type = p->type;
1.228 djm 1250: /*
1251: * If this packet triggers a rekex, then skip the
1252: * remaining packets in the queue for now.
1253: * NB. re-enters this function via kex_start_rekex.
1254: */
1255: if (ssh_packet_need_rekeying(ssh,
1256: sshbuf_len(p->payload))) {
1257: debug3("%s: queued packet triggered rekex",
1258: __func__);
1259: return kex_start_rekex(ssh);
1260: }
1.105 markus 1261: debug("dequeue packet: %u", type);
1.201 markus 1262: sshbuf_free(state->outgoing_packet);
1263: state->outgoing_packet = p->payload;
1264: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1265: memset(p, 0, sizeof(*p));
1.186 djm 1266: free(p);
1.201 markus 1267: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1268: return r;
1.105 markus 1269: }
1270: }
1.201 markus 1271: return 0;
1.25 markus 1272: }
1273:
1274: /*
1.16 markus 1275: * Waits until a packet has been received, and returns its type. Note that
1276: * no other data is processed until this returns, so this function should not
1277: * be used during the interactive session.
1278: */
1.1 deraadt 1279:
1.2 provos 1280: int
1.201 markus 1281: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1282: {
1.201 markus 1283: struct session_state *state = ssh->state;
1.222 markus 1284: int len, r, ms_remain;
1.56 millert 1285: fd_set *setp;
1.14 markus 1286: char buf[8192];
1.155 deraadt 1287: struct timeval timeout, start, *timeoutp = NULL;
1288:
1.25 markus 1289: DBG(debug("packet_read()"));
1.14 markus 1290:
1.214 deraadt 1291: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1292: NFDBITS), sizeof(fd_mask));
1.201 markus 1293: if (setp == NULL)
1294: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1295:
1.205 djm 1296: /*
1297: * Since we are blocking, ensure that all written packets have
1298: * been sent.
1299: */
1.210 markus 1300: if ((r = ssh_packet_write_wait(ssh)) != 0)
1301: goto out;
1.14 markus 1302:
1303: /* Stay in the loop until we have received a complete packet. */
1304: for (;;) {
1305: /* Try to read a packet from the buffer. */
1.201 markus 1306: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1307: if (r != 0)
1308: break;
1.14 markus 1309: /* If we got a packet, return it. */
1.201 markus 1310: if (*typep != SSH_MSG_NONE)
1311: break;
1.16 markus 1312: /*
1313: * Otherwise, wait for some data to arrive, add it to the
1314: * buffer, and try again.
1315: */
1.201 markus 1316: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1317: NFDBITS) * sizeof(fd_mask));
1.201 markus 1318: FD_SET(state->connection_in, setp);
1.16 markus 1319:
1.201 markus 1320: if (state->packet_timeout_ms > 0) {
1321: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1322: timeoutp = &timeout;
1323: }
1.14 markus 1324: /* Wait for some data to arrive. */
1.154 dtucker 1325: for (;;) {
1.201 markus 1326: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1327: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1328: monotime_tv(&start);
1.154 dtucker 1329: }
1.201 markus 1330: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1331: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1332: break;
1.270 dtucker 1333: if (errno != EAGAIN && errno != EINTR) {
1334: r = SSH_ERR_SYSTEM_ERROR;
1335: goto out;
1336: }
1.201 markus 1337: if (state->packet_timeout_ms == -1)
1.154 dtucker 1338: continue;
1339: ms_subtract_diff(&start, &ms_remain);
1340: if (ms_remain <= 0) {
1.201 markus 1341: r = 0;
1.154 dtucker 1342: break;
1343: }
1344: }
1.246 djm 1345: if (r == 0) {
1346: r = SSH_ERR_CONN_TIMEOUT;
1347: goto out;
1348: }
1.14 markus 1349: /* Read data from the socket. */
1.222 markus 1350: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1351: if (len == 0) {
1352: r = SSH_ERR_CONN_CLOSED;
1353: goto out;
1354: }
1355: if (len < 0) {
1356: r = SSH_ERR_SYSTEM_ERROR;
1357: goto out;
1358: }
1.204 djm 1359:
1.14 markus 1360: /* Append it to the buffer. */
1.204 djm 1361: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1362: goto out;
1.14 markus 1363: }
1.210 markus 1364: out:
1.201 markus 1365: free(setp);
1366: return r;
1.1 deraadt 1367: }
1368:
1.77 djm 1369: int
1.201 markus 1370: ssh_packet_read(struct ssh *ssh)
1.77 djm 1371: {
1.201 markus 1372: u_char type;
1373: int r;
1374:
1375: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1376: fatal("%s: %s", __func__, ssh_err(r));
1377: return type;
1.77 djm 1378: }
1379:
1.16 markus 1380: /*
1381: * Waits until a packet has been received, verifies that its type matches
1382: * that given, and gives a fatal error and exits if there is a mismatch.
1383: */
1.1 deraadt 1384:
1.205 djm 1385: int
1386: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1387: {
1.205 djm 1388: int r;
1389: u_char type;
1.1 deraadt 1390:
1.205 djm 1391: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1392: return r;
1393: if (type != expected_type) {
1394: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1395: "Protocol error: expected packet type %d, got %d",
1.205 djm 1396: expected_type, type)) != 0)
1397: return r;
1398: return SSH_ERR_PROTOCOL_ERROR;
1399: }
1400: return 0;
1.1 deraadt 1401: }
1.14 markus 1402:
1.242 markus 1403: static int
1404: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1405: {
1406: struct session_state *state = ssh->state;
1407: const u_char *cp;
1408: size_t need;
1409: int r;
1410:
1411: if (ssh->kex)
1412: return SSH_ERR_INTERNAL_ERROR;
1413: *typep = SSH_MSG_NONE;
1414: cp = sshbuf_ptr(state->input);
1415: if (state->packlen == 0) {
1416: if (sshbuf_len(state->input) < 4 + 1)
1417: return 0; /* packet is incomplete */
1418: state->packlen = PEEK_U32(cp);
1419: if (state->packlen < 4 + 1 ||
1420: state->packlen > PACKET_MAX_SIZE)
1421: return SSH_ERR_MESSAGE_INCOMPLETE;
1422: }
1423: need = state->packlen + 4;
1424: if (sshbuf_len(state->input) < need)
1425: return 0; /* packet is incomplete */
1426: sshbuf_reset(state->incoming_packet);
1427: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1428: state->packlen)) != 0 ||
1429: (r = sshbuf_consume(state->input, need)) != 0 ||
1430: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1431: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1432: return r;
1433: if (ssh_packet_log_type(*typep))
1434: debug3("%s: type %u", __func__, *typep);
1435: /* sshbuf_dump(state->incoming_packet, stderr); */
1436: /* reset for next packet */
1437: state->packlen = 0;
1438: return r;
1439: }
1440:
1.201 markus 1441: int
1442: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1443: {
1.201 markus 1444: struct session_state *state = ssh->state;
1.40 markus 1445: u_int padlen, need;
1.231 djm 1446: u_char *cp;
1.201 markus 1447: u_int maclen, aadlen = 0, authlen = 0, block_size;
1448: struct sshenc *enc = NULL;
1449: struct sshmac *mac = NULL;
1450: struct sshcomp *comp = NULL;
1.200 markus 1451: int r;
1.201 markus 1452:
1.242 markus 1453: if (state->mux)
1454: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1455:
1.201 markus 1456: *typep = SSH_MSG_NONE;
1457:
1458: if (state->packet_discard)
1459: return 0;
1460:
1461: if (state->newkeys[MODE_IN] != NULL) {
1462: enc = &state->newkeys[MODE_IN]->enc;
1463: mac = &state->newkeys[MODE_IN]->mac;
1464: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1465: /* disable mac for authenticated encryption */
1466: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1467: mac = NULL;
1.25 markus 1468: }
1469: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1470: block_size = enc ? enc->block_size : 8;
1.180 markus 1471: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1472:
1.201 markus 1473: if (aadlen && state->packlen == 0) {
1.235 djm 1474: if (cipher_get_length(state->receive_context,
1.201 markus 1475: &state->packlen, state->p_read.seqnr,
1476: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1477: return 0;
1478: if (state->packlen < 1 + 4 ||
1479: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1480: #ifdef PACKET_DEBUG
1.201 markus 1481: sshbuf_dump(state->input, stderr);
1.178 markus 1482: #endif
1.201 markus 1483: logit("Bad packet length %u.", state->packlen);
1484: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1485: return r;
1.217 djm 1486: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1487: }
1.201 markus 1488: sshbuf_reset(state->incoming_packet);
1489: } else if (state->packlen == 0) {
1.25 markus 1490: /*
1491: * check if input size is less than the cipher block size,
1492: * decrypt first block and extract length of incoming packet
1493: */
1.201 markus 1494: if (sshbuf_len(state->input) < block_size)
1495: return 0;
1496: sshbuf_reset(state->incoming_packet);
1497: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1498: &cp)) != 0)
1499: goto out;
1.235 djm 1500: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1501: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1502: block_size, 0, 0)) != 0)
1503: goto out;
1504: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1505: if (state->packlen < 1 + 4 ||
1506: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1507: #ifdef PACKET_DEBUG
1.201 markus 1508: fprintf(stderr, "input: \n");
1509: sshbuf_dump(state->input, stderr);
1510: fprintf(stderr, "incoming_packet: \n");
1511: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1512: #endif
1.201 markus 1513: logit("Bad packet length %u.", state->packlen);
1.234 markus 1514: return ssh_packet_start_discard(ssh, enc, mac, 0,
1515: PACKET_MAX_SIZE);
1.25 markus 1516: }
1.201 markus 1517: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1518: goto out;
1.25 markus 1519: }
1.201 markus 1520: DBG(debug("input: packet len %u", state->packlen+4));
1521:
1.178 markus 1522: if (aadlen) {
1523: /* only the payload is encrypted */
1.201 markus 1524: need = state->packlen;
1.178 markus 1525: } else {
1526: /*
1527: * the payload size and the payload are encrypted, but we
1528: * have a partial packet of block_size bytes
1529: */
1.201 markus 1530: need = 4 + state->packlen - block_size;
1.178 markus 1531: }
1.180 markus 1532: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1533: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1534: if (need % block_size != 0) {
1535: logit("padding error: need %d block %d mod %d",
1.25 markus 1536: need, block_size, need % block_size);
1.234 markus 1537: return ssh_packet_start_discard(ssh, enc, mac, 0,
1538: PACKET_MAX_SIZE - block_size);
1.158 markus 1539: }
1.25 markus 1540: /*
1541: * check if the entire packet has been received and
1.178 markus 1542: * decrypt into incoming_packet:
1543: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1544: * 'need' bytes are encrypted, followed by either
1545: * 'authlen' bytes of authentication tag or
1.178 markus 1546: * 'maclen' bytes of message authentication code.
1.25 markus 1547: */
1.201 markus 1548: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1549: return 0; /* packet is incomplete */
1.25 markus 1550: #ifdef PACKET_DEBUG
1551: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1552: sshbuf_dump(state->input, stderr);
1.25 markus 1553: #endif
1.231 djm 1554: /* EtM: check mac over encrypted input */
1.201 markus 1555: if (mac && mac->enabled && mac->etm) {
1.231 djm 1556: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1557: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1558: sshbuf_ptr(state->input) + aadlen + need + authlen,
1559: maclen)) != 0) {
1560: if (r == SSH_ERR_MAC_INVALID)
1561: logit("Corrupted MAC on input.");
1.201 markus 1562: goto out;
1.231 djm 1563: }
1.201 markus 1564: }
1565: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1566: &cp)) != 0)
1567: goto out;
1.235 djm 1568: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1569: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1570: goto out;
1571: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1572: goto out;
1.29 markus 1573: if (mac && mac->enabled) {
1.231 djm 1574: /* Not EtM: check MAC over cleartext */
1575: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1576: sshbuf_ptr(state->incoming_packet),
1577: sshbuf_len(state->incoming_packet),
1578: sshbuf_ptr(state->input), maclen)) != 0) {
1579: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1580: goto out;
1.159 markus 1581: logit("Corrupted MAC on input.");
1.247 markus 1582: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1583: return SSH_ERR_INTERNAL_ERROR;
1584: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1585: sshbuf_len(state->incoming_packet),
1.247 markus 1586: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1587: }
1.231 djm 1588: /* Remove MAC from input buffer */
1.201 markus 1589: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1590: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1591: goto out;
1.25 markus 1592: }
1.77 djm 1593: if (seqnr_p != NULL)
1.201 markus 1594: *seqnr_p = state->p_read.seqnr;
1595: if (++state->p_read.seqnr == 0)
1.106 itojun 1596: logit("incoming seqnr wraps around");
1.201 markus 1597: if (++state->p_read.packets == 0)
1598: if (!(ssh->compat & SSH_BUG_NOREKEY))
1599: return SSH_ERR_NEED_REKEY;
1600: state->p_read.blocks += (state->packlen + 4) / block_size;
1601: state->p_read.bytes += state->packlen + 4;
1.25 markus 1602:
1603: /* get padlen */
1.201 markus 1604: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1605: DBG(debug("input: padlen %d", padlen));
1.205 djm 1606: if (padlen < 4) {
1607: if ((r = sshpkt_disconnect(ssh,
1608: "Corrupted padlen %d on input.", padlen)) != 0 ||
1609: (r = ssh_packet_write_wait(ssh)) != 0)
1610: return r;
1611: return SSH_ERR_CONN_CORRUPT;
1612: }
1.25 markus 1613:
1614: /* skip packet size + padlen, discard padding */
1.201 markus 1615: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1616: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1617: goto out;
1.25 markus 1618:
1.201 markus 1619: DBG(debug("input: len before de-compress %zd",
1620: sshbuf_len(state->incoming_packet)));
1.25 markus 1621: if (comp && comp->enabled) {
1.201 markus 1622: sshbuf_reset(state->compression_buffer);
1623: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1624: state->compression_buffer)) != 0)
1625: goto out;
1626: sshbuf_reset(state->incoming_packet);
1627: if ((r = sshbuf_putb(state->incoming_packet,
1628: state->compression_buffer)) != 0)
1629: goto out;
1630: DBG(debug("input: len after de-compress %zd",
1631: sshbuf_len(state->incoming_packet)));
1.25 markus 1632: }
1633: /*
1634: * get packet type, implies consume.
1635: * return length of payload (without type field)
1636: */
1.201 markus 1637: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1638: goto out;
1.226 djm 1639: if (ssh_packet_log_type(*typep))
1640: debug3("receive packet: type %u", *typep);
1.205 djm 1641: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1642: if ((r = sshpkt_disconnect(ssh,
1643: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1644: (r = ssh_packet_write_wait(ssh)) != 0)
1645: return r;
1646: return SSH_ERR_PROTOCOL_ERROR;
1647: }
1.243 djm 1648: if (state->hook_in != NULL &&
1649: (r = state->hook_in(ssh, state->incoming_packet, typep,
1650: state->hook_in_ctx)) != 0)
1651: return r;
1.238 markus 1652: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1653: r = ssh_packet_enable_delayed_compress(ssh);
1654: else
1655: r = 0;
1.25 markus 1656: #ifdef PACKET_DEBUG
1.201 markus 1657: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1658: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1659: #endif
1.62 markus 1660: /* reset for next packet */
1.201 markus 1661: state->packlen = 0;
1.228 djm 1662:
1663: /* do we need to rekey? */
1664: if (ssh_packet_need_rekeying(ssh, 0)) {
1665: debug3("%s: rekex triggered", __func__);
1666: if ((r = kex_start_rekex(ssh)) != 0)
1667: return r;
1668: }
1.201 markus 1669: out:
1670: return r;
1.25 markus 1671: }
1672:
1673: int
1.201 markus 1674: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1675: {
1.201 markus 1676: struct session_state *state = ssh->state;
1.96 deraadt 1677: u_int reason, seqnr;
1.201 markus 1678: int r;
1679: u_char *msg;
1.62 markus 1680:
1.25 markus 1681: for (;;) {
1.201 markus 1682: msg = NULL;
1.249 djm 1683: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1684: if (r != 0)
1685: return r;
1686: if (*typep) {
1687: state->keep_alive_timeouts = 0;
1688: DBG(debug("received packet type %d", *typep));
1689: }
1690: switch (*typep) {
1691: case SSH2_MSG_IGNORE:
1692: debug3("Received SSH2_MSG_IGNORE");
1693: break;
1694: case SSH2_MSG_DEBUG:
1695: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1696: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1697: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1698: free(msg);
1.201 markus 1699: return r;
1.48 stevesk 1700: }
1.249 djm 1701: debug("Remote: %.900s", msg);
1702: free(msg);
1703: break;
1704: case SSH2_MSG_DISCONNECT:
1705: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1706: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1707: return r;
1708: /* Ignore normal client exit notifications */
1709: do_log2(ssh->state->server_side &&
1710: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1711: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1712: "Received disconnect from %s port %d:"
1713: "%u: %.400s", ssh_remote_ipaddr(ssh),
1714: ssh_remote_port(ssh), reason, msg);
1715: free(msg);
1716: return SSH_ERR_DISCONNECTED;
1717: case SSH2_MSG_UNIMPLEMENTED:
1718: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1719: return r;
1720: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1721: seqnr);
1722: break;
1723: default:
1724: return 0;
1.25 markus 1725: }
1726: }
1727: }
1728:
1.16 markus 1729: /*
1730: * Buffers the given amount of input characters. This is intended to be used
1731: * together with packet_read_poll.
1732: */
1.1 deraadt 1733:
1.204 djm 1734: int
1.201 markus 1735: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1736: {
1.201 markus 1737: struct session_state *state = ssh->state;
1738: int r;
1739:
1740: if (state->packet_discard) {
1741: state->keep_alive_timeouts = 0; /* ?? */
1742: if (len >= state->packet_discard) {
1743: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1744: return r;
1.201 markus 1745: }
1746: state->packet_discard -= len;
1.204 djm 1747: return 0;
1.159 markus 1748: }
1.201 markus 1749: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1750: return r;
1751:
1752: return 0;
1.28 markus 1753: }
1754:
1755: int
1.201 markus 1756: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1757: {
1.201 markus 1758: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1759: }
1760:
1.16 markus 1761: /*
1762: * Sends a diagnostic message from the server to the client. This message
1763: * can be sent at any time (but not while constructing another message). The
1764: * message is printed immediately, but only if the client is being executed
1765: * in verbose mode. These messages are primarily intended to ease debugging
1766: * authentication problems. The length of the formatted message must not
1.205 djm 1767: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1768: */
1.2 provos 1769: void
1.201 markus 1770: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1771: {
1.14 markus 1772: char buf[1024];
1773: va_list args;
1.201 markus 1774: int r;
1.39 markus 1775:
1.249 djm 1776: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1777: return;
1.14 markus 1778:
1779: va_start(args, fmt);
1780: vsnprintf(buf, sizeof(buf), fmt, args);
1781: va_end(args);
1.265 djm 1782:
1783: debug3("sending debug message: %s", buf);
1.14 markus 1784:
1.249 djm 1785: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1786: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1787: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1788: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1789: (r = sshpkt_send(ssh)) != 0 ||
1790: (r = ssh_packet_write_wait(ssh)) != 0)
1.205 djm 1791: fatal("%s: %s", __func__, ssh_err(r));
1792: }
1793:
1.268 dtucker 1794: void
1795: sshpkt_fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1.245 djm 1796: {
1797: snprintf(s, l, "%.200s%s%s port %d",
1798: ssh->log_preamble ? ssh->log_preamble : "",
1799: ssh->log_preamble ? " " : "",
1800: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1801: }
1802:
1.205 djm 1803: /*
1804: * Pretty-print connection-terminating errors and exit.
1805: */
1806: void
1807: sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
1808: {
1.245 djm 1809: char remote_id[512];
1810:
1.268 dtucker 1811: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.245 djm 1812:
1.205 djm 1813: switch (r) {
1814: case SSH_ERR_CONN_CLOSED:
1.257 markus 1815: ssh_packet_clear_keys(ssh);
1.245 djm 1816: logdie("Connection closed by %s", remote_id);
1.205 djm 1817: case SSH_ERR_CONN_TIMEOUT:
1.257 markus 1818: ssh_packet_clear_keys(ssh);
1.245 djm 1819: logdie("Connection %s %s timed out",
1820: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1821: case SSH_ERR_DISCONNECTED:
1.257 markus 1822: ssh_packet_clear_keys(ssh);
1.245 djm 1823: logdie("Disconnected from %s", remote_id);
1.212 djm 1824: case SSH_ERR_SYSTEM_ERROR:
1.257 markus 1825: if (errno == ECONNRESET) {
1826: ssh_packet_clear_keys(ssh);
1.245 djm 1827: logdie("Connection reset by %s", remote_id);
1.257 markus 1828: }
1.213 djm 1829: /* FALLTHROUGH */
1830: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1831: case SSH_ERR_NO_MAC_ALG_MATCH:
1832: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1833: case SSH_ERR_NO_KEX_ALG_MATCH:
1834: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1835: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.257 markus 1836: ssh_packet_clear_keys(ssh);
1.245 djm 1837: logdie("Unable to negotiate with %s: %s. "
1838: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1839: ssh->kex->failed_choice);
1.212 djm 1840: }
1841: /* FALLTHROUGH */
1.205 djm 1842: default:
1.257 markus 1843: ssh_packet_clear_keys(ssh);
1.245 djm 1844: logdie("%s%sConnection %s %s: %s",
1.205 djm 1845: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 1846: ssh->state->server_side ? "from" : "to",
1.245 djm 1847: remote_id, ssh_err(r));
1.205 djm 1848: }
1.1 deraadt 1849: }
1850:
1.16 markus 1851: /*
1852: * Logs the error plus constructs and sends a disconnect packet, closes the
1853: * connection, and exits. This function never returns. The error message
1854: * should not contain a newline. The length of the formatted message must
1855: * not exceed 1024 bytes.
1856: */
1.2 provos 1857: void
1.201 markus 1858: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1859: {
1.245 djm 1860: char buf[1024], remote_id[512];
1.14 markus 1861: va_list args;
1862: static int disconnecting = 0;
1.201 markus 1863: int r;
1.97 deraadt 1864:
1.14 markus 1865: if (disconnecting) /* Guard against recursive invocations. */
1866: fatal("packet_disconnect called recursively.");
1867: disconnecting = 1;
1868:
1.16 markus 1869: /*
1870: * Format the message. Note that the caller must make sure the
1871: * message is of limited size.
1872: */
1.268 dtucker 1873: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1874: va_start(args, fmt);
1875: vsnprintf(buf, sizeof(buf), fmt, args);
1876: va_end(args);
1877:
1.99 markus 1878: /* Display the error locally */
1.245 djm 1879: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1880:
1.205 djm 1881: /*
1882: * Send the disconnect message to the other side, and wait
1883: * for it to get sent.
1884: */
1885: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1886: sshpkt_fatal(ssh, __func__, r);
1887:
1888: if ((r = ssh_packet_write_wait(ssh)) != 0)
1889: sshpkt_fatal(ssh, __func__, r);
1.14 markus 1890:
1891: /* Close the connection. */
1.201 markus 1892: ssh_packet_close(ssh);
1.112 markus 1893: cleanup_exit(255);
1.1 deraadt 1894: }
1895:
1.205 djm 1896: /*
1897: * Checks if there is any buffered output, and tries to write some of
1898: * the output.
1899: */
1900: int
1.201 markus 1901: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1902: {
1.201 markus 1903: struct session_state *state = ssh->state;
1904: int len = sshbuf_len(state->output);
1.222 markus 1905: int r;
1.97 deraadt 1906:
1.14 markus 1907: if (len > 0) {
1.222 markus 1908: len = write(state->connection_out,
1909: sshbuf_ptr(state->output), len);
1.156 djm 1910: if (len == -1) {
1911: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1912: return 0;
1913: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1914: }
1.222 markus 1915: if (len == 0)
1.205 djm 1916: return SSH_ERR_CONN_CLOSED;
1.201 markus 1917: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1918: return r;
1.14 markus 1919: }
1.205 djm 1920: return 0;
1.1 deraadt 1921: }
1922:
1.16 markus 1923: /*
1924: * Calls packet_write_poll repeatedly until all pending output data has been
1925: * written.
1926: */
1.205 djm 1927: int
1.201 markus 1928: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1929: {
1.56 millert 1930: fd_set *setp;
1.205 djm 1931: int ret, r, ms_remain = 0;
1.154 dtucker 1932: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1933: struct session_state *state = ssh->state;
1.56 millert 1934:
1.214 deraadt 1935: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1936: NFDBITS), sizeof(fd_mask));
1.201 markus 1937: if (setp == NULL)
1.205 djm 1938: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1939: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1940: free(setp);
1.215 djm 1941: return r;
1.216 gsoares 1942: }
1.201 markus 1943: while (ssh_packet_have_data_to_write(ssh)) {
1944: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1945: NFDBITS) * sizeof(fd_mask));
1.201 markus 1946: FD_SET(state->connection_out, setp);
1.154 dtucker 1947:
1.201 markus 1948: if (state->packet_timeout_ms > 0) {
1949: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1950: timeoutp = &timeout;
1951: }
1952: for (;;) {
1.201 markus 1953: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1954: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1955: monotime_tv(&start);
1.154 dtucker 1956: }
1.201 markus 1957: if ((ret = select(state->connection_out + 1,
1.161 andreas 1958: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1959: break;
1.161 andreas 1960: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1961: break;
1.201 markus 1962: if (state->packet_timeout_ms == -1)
1.154 dtucker 1963: continue;
1964: ms_subtract_diff(&start, &ms_remain);
1965: if (ms_remain <= 0) {
1966: ret = 0;
1967: break;
1968: }
1969: }
1970: if (ret == 0) {
1.205 djm 1971: free(setp);
1972: return SSH_ERR_CONN_TIMEOUT;
1973: }
1974: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1975: free(setp);
1976: return r;
1.154 dtucker 1977: }
1.14 markus 1978: }
1.186 djm 1979: free(setp);
1.205 djm 1980: return 0;
1.1 deraadt 1981: }
1982:
1983: /* Returns true if there is buffered data to write to the connection. */
1984:
1.2 provos 1985: int
1.201 markus 1986: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 1987: {
1.201 markus 1988: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 1989: }
1990:
1991: /* Returns true if there is not too much data to write to the connection. */
1992:
1.2 provos 1993: int
1.201 markus 1994: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 1995: {
1.201 markus 1996: if (ssh->state->interactive_mode)
1997: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 1998: else
1.201 markus 1999: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 2000: }
2001:
1.201 markus 2002: void
2003: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 2004: {
1.263 djm 2005: if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
1.101 markus 2006: return;
1.201 markus 2007: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 2008: case AF_INET:
2009: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 2010: if (setsockopt(ssh->state->connection_in,
1.173 djm 2011: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
2012: error("setsockopt IP_TOS %d: %.100s:",
2013: tos, strerror(errno));
2014: break;
2015: case AF_INET6:
2016: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 2017: if (setsockopt(ssh->state->connection_in,
1.173 djm 2018: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2019: error("setsockopt IPV6_TCLASS %d: %.100s:",
2020: tos, strerror(errno));
2021: break;
2022: }
1.101 markus 2023: }
2024:
1.1 deraadt 2025: /* Informs that the current session is interactive. Sets IP flags for that. */
2026:
1.2 provos 2027: void
1.201 markus 2028: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2029: {
1.201 markus 2030: struct session_state *state = ssh->state;
2031:
2032: if (state->set_interactive_called)
1.43 markus 2033: return;
1.201 markus 2034: state->set_interactive_called = 1;
1.1 deraadt 2035:
1.14 markus 2036: /* Record that we are in interactive mode. */
1.201 markus 2037: state->interactive_mode = interactive;
1.1 deraadt 2038:
1.19 markus 2039: /* Only set socket options if using a socket. */
1.201 markus 2040: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2041: return;
1.201 markus 2042: set_nodelay(state->connection_in);
2043: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2044: qos_bulk);
1.1 deraadt 2045: }
2046:
2047: /* Returns true if the current connection is interactive. */
2048:
1.2 provos 2049: int
1.201 markus 2050: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2051: {
1.201 markus 2052: return ssh->state->interactive_mode;
1.12 markus 2053: }
2054:
1.113 deraadt 2055: int
1.201 markus 2056: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2057: {
1.201 markus 2058: struct session_state *state = ssh->state;
2059:
2060: if (state->set_maxsize_called) {
1.106 itojun 2061: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2062: state->max_packet_size, s);
1.14 markus 2063: return -1;
2064: }
2065: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2066: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2067: return -1;
2068: }
1.201 markus 2069: state->set_maxsize_called = 1;
1.66 markus 2070: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2071: state->max_packet_size = s;
1.14 markus 2072: return s;
1.53 markus 2073: }
2074:
1.161 andreas 2075: int
1.201 markus 2076: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2077: {
1.201 markus 2078: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2079: }
2080:
2081: void
1.201 markus 2082: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2083: {
1.201 markus 2084: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2085: }
2086:
2087: u_int
1.201 markus 2088: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2089: {
1.201 markus 2090: return ssh->state->max_packet_size;
1.71 markus 2091: }
2092:
1.105 markus 2093: void
1.244 dtucker 2094: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2095: {
1.244 dtucker 2096: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2097: (unsigned int)seconds);
1.201 markus 2098: ssh->state->rekey_limit = bytes;
2099: ssh->state->rekey_interval = seconds;
1.184 dtucker 2100: }
2101:
2102: time_t
1.201 markus 2103: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2104: {
2105: time_t seconds;
2106:
1.201 markus 2107: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2108: monotime();
1.185 dtucker 2109: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2110: }
2111:
2112: void
1.201 markus 2113: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2114: {
1.201 markus 2115: ssh->state->server_side = 1;
1.118 markus 2116: }
2117:
2118: void
1.201 markus 2119: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2120: {
1.201 markus 2121: ssh->state->after_authentication = 1;
1.161 andreas 2122: }
2123:
2124: void *
1.201 markus 2125: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2126: {
1.201 markus 2127: return (void *)ssh->state->input;
1.161 andreas 2128: }
2129:
2130: void *
1.201 markus 2131: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2132: {
1.201 markus 2133: return (void *)ssh->state->output;
1.166 andreas 2134: }
2135:
1.196 markus 2136: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2137: static int
2138: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2139: {
1.239 djm 2140: int r;
1.196 markus 2141:
2142: debug("%s: called", __func__);
2143: /* This was set in net child, but is not visible in user child */
1.201 markus 2144: ssh->state->after_authentication = 1;
2145: ssh->state->rekeying = 0;
1.239 djm 2146: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2147: return r;
1.201 markus 2148: return 0;
2149: }
2150:
2151: /* Packet state (de-)serialization for privsep */
2152:
2153: /* turn kex into a blob for packet state serialization */
2154: static int
2155: kex_to_blob(struct sshbuf *m, struct kex *kex)
2156: {
2157: int r;
2158:
2159: if ((r = sshbuf_put_string(m, kex->session_id,
2160: kex->session_id_len)) != 0 ||
2161: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
1.269 djm 2162: (r = sshbuf_put_cstring(m, kex->hostkey_alg)) != 0 ||
1.201 markus 2163: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
1.269 djm 2164: (r = sshbuf_put_u32(m, kex->hostkey_nid)) != 0 ||
1.201 markus 2165: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2166: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2167: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2168: (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2169: (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2170: (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2171: return r;
2172: return 0;
2173: }
2174:
2175: /* turn key exchange results into a blob for packet state serialization */
2176: static int
2177: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2178: {
2179: struct sshbuf *b;
2180: struct sshcipher_ctx *cc;
2181: struct sshcomp *comp;
2182: struct sshenc *enc;
2183: struct sshmac *mac;
2184: struct newkeys *newkey;
2185: int r;
2186:
2187: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2188: return SSH_ERR_INTERNAL_ERROR;
2189: enc = &newkey->enc;
2190: mac = &newkey->mac;
2191: comp = &newkey->comp;
1.235 djm 2192: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2193: ssh->state->receive_context;
1.201 markus 2194: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2195: return r;
2196: if ((b = sshbuf_new()) == NULL)
2197: return SSH_ERR_ALLOC_FAIL;
2198: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2199: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2200: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2201: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2202: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2203: goto out;
2204: if (cipher_authlen(enc->cipher) == 0) {
2205: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2206: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2207: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2208: goto out;
2209: }
2210: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2211: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2212: goto out;
2213: r = sshbuf_put_stringb(m, b);
2214: out:
1.221 mmcc 2215: sshbuf_free(b);
1.201 markus 2216: return r;
2217: }
2218:
2219: /* serialize packet state into a blob */
2220: int
2221: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2222: {
2223: struct session_state *state = ssh->state;
1.249 djm 2224: int r;
1.201 markus 2225:
1.249 djm 2226: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2227: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2228: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2229: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2230: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2231: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2232: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2233: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2234: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2235: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2236: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2237: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2238: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2239: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2240: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 2241: return r;
1.201 markus 2242:
2243: return 0;
2244: }
2245:
2246: /* restore key exchange results from blob for packet state de-serialization */
2247: static int
2248: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2249: {
2250: struct sshbuf *b = NULL;
2251: struct sshcomp *comp;
2252: struct sshenc *enc;
2253: struct sshmac *mac;
2254: struct newkeys *newkey = NULL;
2255: size_t keylen, ivlen, maclen;
2256: int r;
2257:
2258: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2259: r = SSH_ERR_ALLOC_FAIL;
2260: goto out;
2261: }
2262: if ((r = sshbuf_froms(m, &b)) != 0)
2263: goto out;
2264: #ifdef DEBUG_PK
2265: sshbuf_dump(b, stderr);
2266: #endif
2267: enc = &newkey->enc;
2268: mac = &newkey->mac;
2269: comp = &newkey->comp;
2270:
2271: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2272: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2273: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2274: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2275: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2276: goto out;
1.262 djm 2277: if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2278: r = SSH_ERR_INVALID_FORMAT;
2279: goto out;
2280: }
1.201 markus 2281: if (cipher_authlen(enc->cipher) == 0) {
2282: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2283: goto out;
2284: if ((r = mac_setup(mac, mac->name)) != 0)
2285: goto out;
2286: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2287: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2288: goto out;
2289: if (maclen > mac->key_len) {
2290: r = SSH_ERR_INVALID_FORMAT;
2291: goto out;
2292: }
2293: mac->key_len = maclen;
2294: }
2295: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2296: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2297: goto out;
2298: if (sshbuf_len(b) != 0) {
2299: r = SSH_ERR_INVALID_FORMAT;
2300: goto out;
2301: }
2302: enc->key_len = keylen;
2303: enc->iv_len = ivlen;
2304: ssh->kex->newkeys[mode] = newkey;
2305: newkey = NULL;
2306: r = 0;
2307: out:
1.219 mmcc 2308: free(newkey);
1.221 mmcc 2309: sshbuf_free(b);
1.201 markus 2310: return r;
2311: }
2312:
2313: /* restore kex from blob for packet state de-serialization */
2314: static int
2315: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2316: {
2317: struct kex *kex;
2318: int r;
2319:
2320: if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2321: (kex->my = sshbuf_new()) == NULL ||
2322: (kex->peer = sshbuf_new()) == NULL) {
2323: r = SSH_ERR_ALLOC_FAIL;
2324: goto out;
2325: }
2326: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2327: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
1.269 djm 2328: (r = sshbuf_get_cstring(m, &kex->hostkey_alg, NULL)) != 0 ||
1.201 markus 2329: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
1.269 djm 2330: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_nid)) != 0 ||
1.201 markus 2331: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2332: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2333: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2334: (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2335: (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2336: (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2337: goto out;
2338: kex->server = 1;
2339: kex->done = 1;
2340: r = 0;
2341: out:
2342: if (r != 0 || kexp == NULL) {
2343: if (kex != NULL) {
1.221 mmcc 2344: sshbuf_free(kex->my);
2345: sshbuf_free(kex->peer);
1.201 markus 2346: free(kex);
2347: }
2348: if (kexp != NULL)
2349: *kexp = NULL;
2350: } else {
2351: *kexp = kex;
2352: }
2353: return r;
2354: }
2355:
2356: /*
2357: * Restore packet state from content of blob 'm' (de-serialization).
2358: * Note that 'm' will be partially consumed on parsing or any other errors.
2359: */
2360: int
2361: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2362: {
2363: struct session_state *state = ssh->state;
1.254 djm 2364: const u_char *input, *output;
2365: size_t ilen, olen;
1.201 markus 2366: int r;
2367:
1.249 djm 2368: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2369: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2370: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2371: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2372: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2373: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2374: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2375: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2376: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2377: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2378: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2379: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2380: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2381: return r;
2382: /*
2383: * We set the time here so that in post-auth privsep slave we
2384: * count from the completion of the authentication.
2385: */
2386: state->rekey_time = monotime();
2387: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2388: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2389: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2390: return r;
1.201 markus 2391:
1.239 djm 2392: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2393: return r;
2394:
2395: sshbuf_reset(state->input);
2396: sshbuf_reset(state->output);
2397: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2398: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2399: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2400: (r = sshbuf_put(state->output, output, olen)) != 0)
2401: return r;
2402:
2403: if (sshbuf_len(m))
2404: return SSH_ERR_INVALID_FORMAT;
2405: debug3("%s: done", __func__);
2406: return 0;
2407: }
2408:
2409: /* NEW API */
2410:
2411: /* put data to the outgoing packet */
2412:
2413: int
2414: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2415: {
2416: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2417: }
2418:
2419: int
2420: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2421: {
2422: return sshbuf_putb(ssh->state->outgoing_packet, b);
2423: }
2424:
2425: int
2426: sshpkt_put_u8(struct ssh *ssh, u_char val)
2427: {
2428: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2429: }
2430:
2431: int
2432: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2433: {
2434: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2435: }
2436:
2437: int
2438: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2439: {
2440: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2441: }
2442:
2443: int
2444: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2445: {
2446: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2447: }
2448:
2449: int
2450: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2451: {
2452: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2453: }
2454:
2455: int
2456: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2457: {
2458: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2459: }
2460:
1.211 djm 2461: #ifdef WITH_OPENSSL
1.201 markus 2462: int
2463: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2464: {
2465: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2466: }
2467:
2468:
2469: int
2470: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2471: {
2472: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2473: }
1.211 djm 2474: #endif /* WITH_OPENSSL */
1.201 markus 2475:
2476: /* fetch data from the incoming packet */
2477:
2478: int
2479: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2480: {
2481: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2482: }
2483:
2484: int
2485: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2486: {
2487: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2488: }
2489:
2490: int
2491: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2492: {
2493: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2494: }
2495:
2496: int
2497: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2498: {
2499: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2500: }
2501:
2502: int
2503: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2504: {
2505: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2506: }
2507:
2508: int
2509: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2510: {
2511: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2512: }
2513:
2514: int
1.264 djm 2515: sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2516: {
2517: return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2518: }
2519:
2520: int
1.201 markus 2521: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2522: {
2523: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2524: }
2525:
1.211 djm 2526: #ifdef WITH_OPENSSL
1.201 markus 2527: int
2528: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2529: {
2530: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2531: }
2532:
2533:
2534: int
2535: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2536: {
2537: return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2538: }
1.211 djm 2539: #endif /* WITH_OPENSSL */
1.201 markus 2540:
2541: int
2542: sshpkt_get_end(struct ssh *ssh)
2543: {
2544: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2545: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2546: return 0;
2547: }
2548:
2549: const u_char *
2550: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2551: {
2552: if (lenp != NULL)
2553: *lenp = sshbuf_len(ssh->state->incoming_packet);
2554: return sshbuf_ptr(ssh->state->incoming_packet);
2555: }
2556:
2557: /* start a new packet */
2558:
2559: int
2560: sshpkt_start(struct ssh *ssh, u_char type)
2561: {
1.249 djm 2562: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2563:
2564: DBG(debug("packet_start[%d]", type));
1.249 djm 2565: memset(buf, 0, sizeof(buf));
2566: buf[sizeof(buf) - 1] = type;
1.201 markus 2567: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2568: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2569: }
2570:
1.242 markus 2571: static int
2572: ssh_packet_send_mux(struct ssh *ssh)
2573: {
2574: struct session_state *state = ssh->state;
2575: u_char type, *cp;
2576: size_t len;
2577: int r;
2578:
2579: if (ssh->kex)
2580: return SSH_ERR_INTERNAL_ERROR;
2581: len = sshbuf_len(state->outgoing_packet);
2582: if (len < 6)
2583: return SSH_ERR_INTERNAL_ERROR;
2584: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2585: type = cp[5];
2586: if (ssh_packet_log_type(type))
2587: debug3("%s: type %u", __func__, type);
2588: /* drop everything, but the connection protocol */
2589: if (type >= SSH2_MSG_CONNECTION_MIN &&
2590: type <= SSH2_MSG_CONNECTION_MAX) {
2591: POKE_U32(cp, len - 4);
2592: if ((r = sshbuf_putb(state->output,
2593: state->outgoing_packet)) != 0)
2594: return r;
2595: /* sshbuf_dump(state->output, stderr); */
2596: }
2597: sshbuf_reset(state->outgoing_packet);
1.264 djm 2598: return 0;
2599: }
2600:
2601: /*
2602: * 9.2. Ignored Data Message
2603: *
2604: * byte SSH_MSG_IGNORE
2605: * string data
2606: *
2607: * All implementations MUST understand (and ignore) this message at any
2608: * time (after receiving the protocol version). No implementation is
2609: * required to send them. This message can be used as an additional
2610: * protection measure against advanced traffic analysis techniques.
2611: */
2612: int
2613: sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2614: {
2615: u_int32_t rnd = 0;
2616: int r;
2617: u_int i;
2618:
2619: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2620: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2621: return r;
2622: for (i = 0; i < nbytes; i++) {
2623: if (i % 4 == 0)
2624: rnd = arc4random();
2625: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2626: return r;
2627: rnd >>= 8;
2628: }
1.242 markus 2629: return 0;
2630: }
2631:
1.201 markus 2632: /* send it */
2633:
2634: int
2635: sshpkt_send(struct ssh *ssh)
2636: {
1.242 markus 2637: if (ssh->state && ssh->state->mux)
2638: return ssh_packet_send_mux(ssh);
1.249 djm 2639: return ssh_packet_send2(ssh);
1.201 markus 2640: }
2641:
2642: int
2643: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2644: {
2645: char buf[1024];
2646: va_list args;
2647: int r;
2648:
2649: va_start(args, fmt);
2650: vsnprintf(buf, sizeof(buf), fmt, args);
2651: va_end(args);
2652:
1.249 djm 2653: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2654: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2655: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2656: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2657: (r = sshpkt_send(ssh)) != 0)
2658: return r;
1.201 markus 2659: return 0;
2660: }
2661:
2662: /* roundup current message to pad bytes */
2663: int
2664: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2665: {
2666: ssh->state->extra_pad = pad;
2667: return 0;
1.1 deraadt 2668: }
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