Annotation of src/usr.bin/ssh/packet.c, Revision 1.247
1.247 ! markus 1: /* $OpenBSD: packet.c,v 1.246 2017/02/28 06:10:08 djm 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"
1.9 dugsong 65: #include "deattack.h"
1.25 markus 66: #include "compat.h"
1.45 markus 67: #include "ssh1.h"
1.25 markus 68: #include "ssh2.h"
1.37 markus 69: #include "cipher.h"
1.201 markus 70: #include "sshkey.h"
1.25 markus 71: #include "kex.h"
1.200 markus 72: #include "digest.h"
1.50 markus 73: #include "mac.h"
1.46 markus 74: #include "log.h"
75: #include "canohost.h"
1.87 stevesk 76: #include "misc.h"
1.198 millert 77: #include "channels.h"
1.95 markus 78: #include "ssh.h"
1.201 markus 79: #include "packet.h"
1.197 djm 80: #include "ssherr.h"
1.201 markus 81: #include "sshbuf.h"
1.25 markus 82:
83: #ifdef PACKET_DEBUG
84: #define DBG(x) x
85: #else
86: #define DBG(x)
87: #endif
88:
1.159 markus 89: #define PACKET_MAX_SIZE (256 * 1024)
90:
1.161 andreas 91: struct packet_state {
92: u_int32_t seqnr;
93: u_int32_t packets;
94: u_int64_t blocks;
95: u_int64_t bytes;
96: };
97:
98: struct packet {
99: TAILQ_ENTRY(packet) next;
100: u_char type;
1.201 markus 101: struct sshbuf *payload;
1.161 andreas 102: };
103:
104: struct session_state {
105: /*
106: * This variable contains the file descriptors used for
107: * communicating with the other side. connection_in is used for
108: * reading; connection_out for writing. These can be the same
109: * descriptor, in which case it is assumed to be a socket.
110: */
111: int connection_in;
112: int connection_out;
113:
114: /* Protocol flags for the remote side. */
115: u_int remote_protocol_flags;
1.1 deraadt 116:
1.161 andreas 117: /* Encryption context for receiving data. Only used for decryption. */
1.235 djm 118: struct sshcipher_ctx *receive_context;
1.1 deraadt 119:
1.161 andreas 120: /* Encryption context for sending data. Only used for encryption. */
1.235 djm 121: struct sshcipher_ctx *send_context;
1.14 markus 122:
1.161 andreas 123: /* Buffer for raw input data from the socket. */
1.201 markus 124: struct sshbuf *input;
1.1 deraadt 125:
1.161 andreas 126: /* Buffer for raw output data going to the socket. */
1.201 markus 127: struct sshbuf *output;
1.1 deraadt 128:
1.161 andreas 129: /* Buffer for the partial outgoing packet being constructed. */
1.201 markus 130: struct sshbuf *outgoing_packet;
1.1 deraadt 131:
1.161 andreas 132: /* Buffer for the incoming packet currently being processed. */
1.201 markus 133: struct sshbuf *incoming_packet;
1.1 deraadt 134:
1.161 andreas 135: /* Scratch buffer for packet compression/decompression. */
1.201 markus 136: struct sshbuf *compression_buffer;
137:
138: /* Incoming/outgoing compression dictionaries */
139: z_stream compression_in_stream;
140: z_stream compression_out_stream;
141: int compression_in_started;
142: int compression_out_started;
143: int compression_in_failures;
144: int compression_out_failures;
1.1 deraadt 145:
1.161 andreas 146: /*
147: * Flag indicating whether packet compression/decompression is
148: * enabled.
149: */
150: int packet_compression;
1.1 deraadt 151:
1.161 andreas 152: /* default maximum packet size */
153: u_int max_packet_size;
1.1 deraadt 154:
1.161 andreas 155: /* Flag indicating whether this module has been initialized. */
156: int initialized;
1.12 markus 157:
1.161 andreas 158: /* Set to true if the connection is interactive. */
159: int interactive_mode;
1.1 deraadt 160:
1.161 andreas 161: /* Set to true if we are the server side. */
162: int server_side;
1.1 deraadt 163:
1.161 andreas 164: /* Set to true if we are authenticated. */
165: int after_authentication;
1.118 markus 166:
1.161 andreas 167: int keep_alive_timeouts;
1.118 markus 168:
1.161 andreas 169: /* The maximum time that we will wait to send or receive a packet */
170: int packet_timeout_ms;
1.151 dtucker 171:
1.161 andreas 172: /* Session key information for Encryption and MAC */
1.201 markus 173: struct newkeys *newkeys[MODE_MAX];
1.161 andreas 174: struct packet_state p_read, p_send;
1.154 dtucker 175:
1.184 dtucker 176: /* Volume-based rekeying */
1.224 dtucker 177: u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
1.105 markus 178:
1.184 dtucker 179: /* Time-based rekeying */
1.208 markus 180: u_int32_t rekey_interval; /* how often in seconds */
1.184 dtucker 181: time_t rekey_time; /* time of last rekeying */
182:
1.161 andreas 183: /* Session key for protocol v1 */
184: u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
185: u_int ssh1_keylen;
1.25 markus 186:
1.161 andreas 187: /* roundup current message to extra_pad bytes */
188: u_char extra_pad;
1.95 markus 189:
1.161 andreas 190: /* XXX discard incoming data after MAC error */
191: u_int packet_discard;
1.234 markus 192: size_t packet_discard_mac_already;
1.201 markus 193: struct sshmac *packet_discard_mac;
1.71 markus 194:
1.161 andreas 195: /* Used in packet_read_poll2() */
196: u_int packlen;
1.159 markus 197:
1.165 andreas 198: /* Used in packet_send2 */
199: int rekeying;
200:
1.242 markus 201: /* Used in ssh_packet_send_mux() */
202: int mux;
203:
1.165 andreas 204: /* Used in packet_set_interactive */
205: int set_interactive_called;
206:
207: /* Used in packet_set_maxsize */
208: int set_maxsize_called;
209:
1.201 markus 210: /* One-off warning about weak ciphers */
211: int cipher_warning_done;
212:
213: /* SSH1 CRC compensation attack detector */
214: struct deattack_ctx deattack;
215:
1.243 djm 216: /* Hook for fuzzing inbound packets */
217: ssh_packet_hook_fn *hook_in;
218: void *hook_in_ctx;
219:
1.161 andreas 220: TAILQ_HEAD(, packet) outgoing;
1.105 markus 221: };
1.161 andreas 222:
1.201 markus 223: struct ssh *
224: ssh_alloc_session_state(void)
1.161 andreas 225: {
1.201 markus 226: struct ssh *ssh = NULL;
227: struct session_state *state = NULL;
1.161 andreas 228:
1.201 markus 229: if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
230: (state = calloc(1, sizeof(*state))) == NULL ||
231: (state->input = sshbuf_new()) == NULL ||
232: (state->output = sshbuf_new()) == NULL ||
233: (state->outgoing_packet = sshbuf_new()) == NULL ||
234: (state->incoming_packet = sshbuf_new()) == NULL)
235: goto fail;
236: TAILQ_INIT(&state->outgoing);
1.202 markus 237: TAILQ_INIT(&ssh->private_keys);
238: TAILQ_INIT(&ssh->public_keys);
1.201 markus 239: state->connection_in = -1;
240: state->connection_out = -1;
241: state->max_packet_size = 32768;
242: state->packet_timeout_ms = -1;
243: state->p_send.packets = state->p_read.packets = 0;
244: state->initialized = 1;
245: /*
246: * ssh_packet_send2() needs to queue packets until
247: * we've done the initial key exchange.
248: */
249: state->rekeying = 1;
250: ssh->state = state;
251: return ssh;
252: fail:
253: if (state) {
254: sshbuf_free(state->input);
255: sshbuf_free(state->output);
256: sshbuf_free(state->incoming_packet);
257: sshbuf_free(state->outgoing_packet);
258: free(state);
259: }
260: free(ssh);
261: return NULL;
1.161 andreas 262: }
1.105 markus 263:
1.243 djm 264: void
265: ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
266: {
267: ssh->state->hook_in = hook;
268: ssh->state->hook_in_ctx = ctx;
269: }
270:
1.228 djm 271: /* Returns nonzero if rekeying is in progress */
272: int
273: ssh_packet_is_rekeying(struct ssh *ssh)
274: {
1.229 djm 275: return compat20 &&
276: (ssh->state->rekeying || (ssh->kex != NULL && ssh->kex->done == 0));
1.228 djm 277: }
278:
1.16 markus 279: /*
280: * Sets the descriptors used for communication. Disables encryption until
281: * packet_set_encryption_key is called.
282: */
1.201 markus 283: struct ssh *
284: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1 deraadt 285: {
1.201 markus 286: struct session_state *state;
287: const struct sshcipher *none = cipher_by_name("none");
1.197 djm 288: int r;
1.97 deraadt 289:
1.205 djm 290: if (none == NULL) {
291: error("%s: cannot load cipher 'none'", __func__);
292: return NULL;
293: }
1.201 markus 294: if (ssh == NULL)
295: ssh = ssh_alloc_session_state();
1.205 djm 296: if (ssh == NULL) {
297: error("%s: cound not allocate state", __func__);
298: return NULL;
299: }
1.201 markus 300: state = ssh->state;
301: state->connection_in = fd_in;
302: state->connection_out = fd_out;
303: if ((r = cipher_init(&state->send_context, none,
1.197 djm 304: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201 markus 305: (r = cipher_init(&state->receive_context, none,
1.205 djm 306: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
307: error("%s: cipher_init failed: %s", __func__, ssh_err(r));
1.230 djm 308: free(ssh); /* XXX need ssh_free_session_state? */
1.205 djm 309: return NULL;
310: }
1.201 markus 311: state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
312: deattack_init(&state->deattack);
1.207 djm 313: /*
314: * Cache the IP address of the remote connection for use in error
315: * messages that might be generated after the connection has closed.
316: */
317: (void)ssh_remote_ipaddr(ssh);
1.201 markus 318: return ssh;
1.1 deraadt 319: }
320:
1.154 dtucker 321: void
1.201 markus 322: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 323: {
1.201 markus 324: struct session_state *state = ssh->state;
325:
1.174 djm 326: if (timeout <= 0 || count <= 0) {
1.201 markus 327: state->packet_timeout_ms = -1;
1.154 dtucker 328: return;
329: }
330: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 331: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 332: else
1.201 markus 333: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 334: }
335:
1.242 markus 336: void
337: ssh_packet_set_mux(struct ssh *ssh)
338: {
339: ssh->state->mux = 1;
340: ssh->state->rekeying = 0;
341: }
342:
343: int
344: ssh_packet_get_mux(struct ssh *ssh)
345: {
346: return ssh->state->mux;
347: }
348:
1.201 markus 349: int
1.245 djm 350: ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
351: {
352: va_list args;
353: int r;
354:
355: free(ssh->log_preamble);
356: if (fmt == NULL)
357: ssh->log_preamble = NULL;
358: else {
359: va_start(args, fmt);
360: r = vasprintf(&ssh->log_preamble, fmt, args);
361: va_end(args);
362: if (r < 0 || ssh->log_preamble == NULL)
363: return SSH_ERR_ALLOC_FAIL;
364: }
365: return 0;
366: }
367:
368: int
1.201 markus 369: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 370: {
1.201 markus 371: struct session_state *state = ssh->state;
372: int r;
373:
374: if (state->packet_discard_mac) {
1.159 markus 375: char buf[1024];
1.234 markus 376: size_t dlen = PACKET_MAX_SIZE;
1.201 markus 377:
1.234 markus 378: if (dlen > state->packet_discard_mac_already)
379: dlen -= state->packet_discard_mac_already;
1.159 markus 380: memset(buf, 'a', sizeof(buf));
1.234 markus 381: while (sshbuf_len(state->incoming_packet) < dlen)
1.201 markus 382: if ((r = sshbuf_put(state->incoming_packet, buf,
383: sizeof(buf))) != 0)
384: return r;
385: (void) mac_compute(state->packet_discard_mac,
386: state->p_read.seqnr,
1.234 markus 387: sshbuf_ptr(state->incoming_packet), dlen,
1.201 markus 388: NULL, 0);
1.159 markus 389: }
1.220 djm 390: logit("Finished discarding for %.200s port %d",
391: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 392: return SSH_ERR_MAC_INVALID;
1.159 markus 393: }
394:
1.201 markus 395: static int
396: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
1.234 markus 397: struct sshmac *mac, size_t mac_already, u_int discard)
1.159 markus 398: {
1.201 markus 399: struct session_state *state = ssh->state;
400: int r;
401:
402: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
403: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
404: return r;
405: return SSH_ERR_MAC_INVALID;
406: }
1.234 markus 407: /*
408: * Record number of bytes over which the mac has already
409: * been computed in order to minimize timing attacks.
410: */
411: if (mac && mac->enabled) {
1.201 markus 412: state->packet_discard_mac = mac;
1.234 markus 413: state->packet_discard_mac_already = mac_already;
414: }
415: if (sshbuf_len(state->input) >= discard)
416: return ssh_packet_stop_discard(ssh);
1.201 markus 417: state->packet_discard = discard - sshbuf_len(state->input);
418: return 0;
1.159 markus 419: }
420:
1.19 markus 421: /* Returns 1 if remote host is connected via socket, 0 if not. */
422:
423: int
1.201 markus 424: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 425: {
1.201 markus 426: struct session_state *state = ssh->state;
1.19 markus 427: struct sockaddr_storage from, to;
428: socklen_t fromlen, tolen;
429:
1.230 djm 430: if (state->connection_in == -1 || state->connection_out == -1)
431: return 0;
432:
1.19 markus 433: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 434: if (state->connection_in == state->connection_out)
1.19 markus 435: return 1;
436: fromlen = sizeof(from);
437: memset(&from, 0, sizeof(from));
1.201 markus 438: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.161 andreas 439: &fromlen) < 0)
1.19 markus 440: return 0;
441: tolen = sizeof(to);
442: memset(&to, 0, sizeof(to));
1.201 markus 443: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.161 andreas 444: &tolen) < 0)
1.19 markus 445: return 0;
446: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
447: return 0;
448: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
449: return 0;
450: return 1;
451: }
452:
1.91 markus 453: void
1.201 markus 454: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 455: {
1.201 markus 456: if (ibytes)
457: *ibytes = ssh->state->p_read.bytes;
458: if (obytes)
459: *obytes = ssh->state->p_send.bytes;
1.91 markus 460: }
1.125 deraadt 461:
1.91 markus 462: int
1.201 markus 463: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 464: {
465: struct sockaddr_storage to;
1.21 deraadt 466: socklen_t tolen = sizeof(to);
1.19 markus 467:
468: memset(&to, 0, sizeof(to));
1.201 markus 469: if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
1.161 andreas 470: &tolen) < 0)
1.19 markus 471: return 0;
1.173 djm 472: return to.ss_family;
1.19 markus 473: }
474:
1.1 deraadt 475: /* Sets the connection into non-blocking mode. */
476:
1.2 provos 477: void
1.201 markus 478: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 479: {
1.14 markus 480: /* Set the socket into non-blocking mode. */
1.201 markus 481: set_nonblock(ssh->state->connection_in);
1.14 markus 482:
1.201 markus 483: if (ssh->state->connection_out != ssh->state->connection_in)
484: set_nonblock(ssh->state->connection_out);
1.1 deraadt 485: }
486:
487: /* Returns the socket used for reading. */
488:
1.2 provos 489: int
1.201 markus 490: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 491: {
1.201 markus 492: return ssh->state->connection_in;
1.1 deraadt 493: }
494:
495: /* Returns the descriptor used for writing. */
496:
1.2 provos 497: int
1.201 markus 498: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 499: {
1.201 markus 500: return ssh->state->connection_out;
501: }
502:
503: /*
504: * Returns the IP-address of the remote host as a string. The returned
505: * string must not be freed.
506: */
507:
508: const char *
509: ssh_remote_ipaddr(struct ssh *ssh)
510: {
1.220 djm 511: const int sock = ssh->state->connection_in;
512:
1.201 markus 513: /* Check whether we have cached the ipaddr. */
1.220 djm 514: if (ssh->remote_ipaddr == NULL) {
515: if (ssh_packet_connection_is_on_socket(ssh)) {
516: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 djm 517: ssh->remote_port = get_peer_port(sock);
518: ssh->local_ipaddr = get_local_ipaddr(sock);
519: ssh->local_port = get_local_port(sock);
1.220 djm 520: } else {
521: ssh->remote_ipaddr = strdup("UNKNOWN");
1.230 djm 522: ssh->remote_port = 65535;
523: ssh->local_ipaddr = strdup("UNKNOWN");
524: ssh->local_port = 65535;
1.220 djm 525: }
526: }
1.201 markus 527: return ssh->remote_ipaddr;
1.1 deraadt 528: }
529:
1.220 djm 530: /* Returns the port number of the remote host. */
531:
532: int
533: ssh_remote_port(struct ssh *ssh)
534: {
535: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
536: return ssh->remote_port;
1.230 djm 537: }
538:
539: /*
540: * Returns the IP-address of the local host as a string. The returned
541: * string must not be freed.
542: */
543:
544: const char *
545: ssh_local_ipaddr(struct ssh *ssh)
546: {
547: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
548: return ssh->local_ipaddr;
549: }
550:
551: /* Returns the port number of the local host. */
552:
553: int
554: ssh_local_port(struct ssh *ssh)
555: {
556: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
557: return ssh->local_port;
1.220 djm 558: }
559:
1.1 deraadt 560: /* Closes the connection and clears and frees internal data structures. */
561:
1.2 provos 562: void
1.201 markus 563: ssh_packet_close(struct ssh *ssh)
1.1 deraadt 564: {
1.201 markus 565: struct session_state *state = ssh->state;
566: u_int mode;
567:
568: if (!state->initialized)
1.14 markus 569: return;
1.201 markus 570: state->initialized = 0;
571: if (state->connection_in == state->connection_out) {
572: shutdown(state->connection_out, SHUT_RDWR);
573: close(state->connection_out);
1.14 markus 574: } else {
1.201 markus 575: close(state->connection_in);
576: close(state->connection_out);
1.14 markus 577: }
1.201 markus 578: sshbuf_free(state->input);
579: sshbuf_free(state->output);
580: sshbuf_free(state->outgoing_packet);
581: sshbuf_free(state->incoming_packet);
582: for (mode = 0; mode < MODE_MAX; mode++)
583: kex_free_newkeys(state->newkeys[mode]);
584: if (state->compression_buffer) {
585: sshbuf_free(state->compression_buffer);
586: if (state->compression_out_started) {
587: z_streamp stream = &state->compression_out_stream;
588: debug("compress outgoing: "
589: "raw data %llu, compressed %llu, factor %.2f",
590: (unsigned long long)stream->total_in,
591: (unsigned long long)stream->total_out,
592: stream->total_in == 0 ? 0.0 :
593: (double) stream->total_out / stream->total_in);
594: if (state->compression_out_failures == 0)
595: deflateEnd(stream);
596: }
597: if (state->compression_in_started) {
598: z_streamp stream = &state->compression_out_stream;
599: debug("compress incoming: "
600: "raw data %llu, compressed %llu, factor %.2f",
601: (unsigned long long)stream->total_out,
602: (unsigned long long)stream->total_in,
603: stream->total_out == 0 ? 0.0 :
604: (double) stream->total_in / stream->total_out);
605: if (state->compression_in_failures == 0)
606: inflateEnd(stream);
607: }
1.14 markus 608: }
1.235 djm 609: cipher_free(state->send_context);
610: cipher_free(state->receive_context);
611: state->send_context = state->receive_context = NULL;
1.219 mmcc 612: free(ssh->remote_ipaddr);
613: ssh->remote_ipaddr = NULL;
1.201 markus 614: free(ssh->state);
615: ssh->state = NULL;
1.1 deraadt 616: }
617:
618: /* Sets remote side protocol flags. */
619:
1.2 provos 620: void
1.201 markus 621: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 622: {
1.201 markus 623: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 624: }
625:
626: /* Returns the remote protocol flags set earlier by the above function. */
627:
1.40 markus 628: u_int
1.201 markus 629: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 630: {
1.201 markus 631: return ssh->state->remote_protocol_flags;
1.1 deraadt 632: }
633:
1.16 markus 634: /*
635: * Starts packet compression from the next packet on in both directions.
636: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
637: */
1.1 deraadt 638:
1.201 markus 639: static int
640: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 641: {
1.201 markus 642: if (!ssh->state->compression_buffer &&
643: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
644: return SSH_ERR_ALLOC_FAIL;
645: return 0;
1.60 markus 646: }
647:
1.201 markus 648: static int
649: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 650: {
1.201 markus 651: if (level < 1 || level > 9)
652: return SSH_ERR_INVALID_ARGUMENT;
653: debug("Enabling compression at level %d.", level);
654: if (ssh->state->compression_out_started == 1)
655: deflateEnd(&ssh->state->compression_out_stream);
656: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
657: case Z_OK:
658: ssh->state->compression_out_started = 1;
659: break;
660: case Z_MEM_ERROR:
661: return SSH_ERR_ALLOC_FAIL;
662: default:
663: return SSH_ERR_INTERNAL_ERROR;
664: }
665: return 0;
1.1 deraadt 666: }
667:
1.201 markus 668: static int
669: start_compression_in(struct ssh *ssh)
670: {
671: if (ssh->state->compression_in_started == 1)
672: inflateEnd(&ssh->state->compression_in_stream);
673: switch (inflateInit(&ssh->state->compression_in_stream)) {
674: case Z_OK:
675: ssh->state->compression_in_started = 1;
676: break;
677: case Z_MEM_ERROR:
678: return SSH_ERR_ALLOC_FAIL;
679: default:
680: return SSH_ERR_INTERNAL_ERROR;
681: }
682: return 0;
683: }
1.95 markus 684:
1.201 markus 685: int
686: ssh_packet_start_compression(struct ssh *ssh, int level)
1.1 deraadt 687: {
1.197 djm 688: int r;
1.97 deraadt 689:
1.201 markus 690: if (ssh->state->packet_compression && !compat20)
691: return SSH_ERR_INTERNAL_ERROR;
692: ssh->state->packet_compression = 1;
693: if ((r = ssh_packet_init_compression(ssh)) != 0 ||
694: (r = start_compression_in(ssh)) != 0 ||
695: (r = start_compression_out(ssh, level)) != 0)
696: return r;
697: return 0;
1.95 markus 698: }
699:
1.201 markus 700: /* XXX remove need for separate compression buffer */
701: static int
702: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 703: {
1.201 markus 704: u_char buf[4096];
705: int r, status;
706:
707: if (ssh->state->compression_out_started != 1)
708: return SSH_ERR_INTERNAL_ERROR;
709:
710: /* This case is not handled below. */
711: if (sshbuf_len(in) == 0)
712: return 0;
713:
714: /* Input is the contents of the input buffer. */
715: if ((ssh->state->compression_out_stream.next_in =
716: sshbuf_mutable_ptr(in)) == NULL)
717: return SSH_ERR_INTERNAL_ERROR;
718: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
719:
720: /* Loop compressing until deflate() returns with avail_out != 0. */
721: do {
722: /* Set up fixed-size output buffer. */
723: ssh->state->compression_out_stream.next_out = buf;
724: ssh->state->compression_out_stream.avail_out = sizeof(buf);
725:
726: /* Compress as much data into the buffer as possible. */
727: status = deflate(&ssh->state->compression_out_stream,
728: Z_PARTIAL_FLUSH);
729: switch (status) {
730: case Z_MEM_ERROR:
731: return SSH_ERR_ALLOC_FAIL;
732: case Z_OK:
733: /* Append compressed data to output_buffer. */
734: if ((r = sshbuf_put(out, buf, sizeof(buf) -
735: ssh->state->compression_out_stream.avail_out)) != 0)
736: return r;
737: break;
738: case Z_STREAM_ERROR:
739: default:
740: ssh->state->compression_out_failures++;
741: return SSH_ERR_INVALID_FORMAT;
742: }
743: } while (ssh->state->compression_out_stream.avail_out == 0);
744: return 0;
1.1 deraadt 745: }
746:
1.201 markus 747: static int
748: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 749: {
1.201 markus 750: u_char buf[4096];
751: int r, status;
1.1 deraadt 752:
1.201 markus 753: if (ssh->state->compression_in_started != 1)
754: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 755:
1.201 markus 756: if ((ssh->state->compression_in_stream.next_in =
757: sshbuf_mutable_ptr(in)) == NULL)
758: return SSH_ERR_INTERNAL_ERROR;
759: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 760:
1.201 markus 761: for (;;) {
762: /* Set up fixed-size output buffer. */
763: ssh->state->compression_in_stream.next_out = buf;
764: ssh->state->compression_in_stream.avail_out = sizeof(buf);
765:
766: status = inflate(&ssh->state->compression_in_stream,
767: Z_PARTIAL_FLUSH);
768: switch (status) {
769: case Z_OK:
770: if ((r = sshbuf_put(out, buf, sizeof(buf) -
771: ssh->state->compression_in_stream.avail_out)) != 0)
772: return r;
773: break;
774: case Z_BUF_ERROR:
775: /*
776: * Comments in zlib.h say that we should keep calling
777: * inflate() until we get an error. This appears to
778: * be the error that we get.
779: */
780: return 0;
781: case Z_DATA_ERROR:
782: return SSH_ERR_INVALID_FORMAT;
783: case Z_MEM_ERROR:
784: return SSH_ERR_ALLOC_FAIL;
785: case Z_STREAM_ERROR:
786: default:
787: ssh->state->compression_in_failures++;
788: return SSH_ERR_INTERNAL_ERROR;
789: }
790: }
791: /* NOTREACHED */
1.1 deraadt 792: }
1.125 deraadt 793:
1.201 markus 794: /*
795: * Causes any further packets to be encrypted using the given key. The same
796: * key is used for both sending and reception. However, both directions are
797: * encrypted independently of each other.
798: */
1.125 deraadt 799:
1.2 provos 800: void
1.201 markus 801: ssh_packet_set_encryption_key(struct ssh *ssh, const u_char *key, u_int keylen, int number)
1.1 deraadt 802: {
1.211 djm 803: #ifndef WITH_SSH1
804: fatal("no SSH protocol 1 support");
805: #else /* WITH_SSH1 */
1.201 markus 806: struct session_state *state = ssh->state;
807: const struct sshcipher *cipher = cipher_by_number(number);
808: int r;
809: const char *wmsg;
1.125 deraadt 810:
1.201 markus 811: if (cipher == NULL)
812: fatal("%s: unknown cipher number %d", __func__, number);
813: if (keylen < 20)
814: fatal("%s: keylen too small: %d", __func__, keylen);
815: if (keylen > SSH_SESSION_KEY_LENGTH)
816: fatal("%s: keylen too big: %d", __func__, keylen);
817: memcpy(state->ssh1_key, key, keylen);
818: state->ssh1_keylen = keylen;
819: if ((r = cipher_init(&state->send_context, cipher, key, keylen,
820: NULL, 0, CIPHER_ENCRYPT)) != 0 ||
821: (r = cipher_init(&state->receive_context, cipher, key, keylen,
822: NULL, 0, CIPHER_DECRYPT) != 0))
823: fatal("%s: cipher_init failed: %s", __func__, ssh_err(r));
824: if (!state->cipher_warning_done &&
1.235 djm 825: ((wmsg = cipher_warning_message(state->send_context)) != NULL ||
826: (wmsg = cipher_warning_message(state->send_context)) != NULL)) {
1.201 markus 827: error("Warning: %s", wmsg);
828: state->cipher_warning_done = 1;
829: }
1.211 djm 830: #endif /* WITH_SSH1 */
1.170 djm 831: }
832:
1.16 markus 833: /*
834: * Finalizes and sends the packet. If the encryption key has been set,
835: * encrypts the packet before sending.
836: */
1.14 markus 837:
1.201 markus 838: int
839: ssh_packet_send1(struct ssh *ssh)
1.1 deraadt 840: {
1.201 markus 841: struct session_state *state = ssh->state;
1.89 markus 842: u_char buf[8], *cp;
1.201 markus 843: int r, padding, len;
1.40 markus 844: u_int checksum;
1.14 markus 845:
1.16 markus 846: /*
847: * If using packet compression, compress the payload of the outgoing
848: * packet.
849: */
1.201 markus 850: if (state->packet_compression) {
851: sshbuf_reset(state->compression_buffer);
1.14 markus 852: /* Skip padding. */
1.201 markus 853: if ((r = sshbuf_consume(state->outgoing_packet, 8)) != 0)
854: goto out;
1.14 markus 855: /* padding */
1.201 markus 856: if ((r = sshbuf_put(state->compression_buffer,
857: "\0\0\0\0\0\0\0\0", 8)) != 0)
858: goto out;
859: if ((r = compress_buffer(ssh, state->outgoing_packet,
860: state->compression_buffer)) != 0)
861: goto out;
862: sshbuf_reset(state->outgoing_packet);
863: if ((r = sshbuf_putb(state->outgoing_packet,
864: state->compression_buffer)) != 0)
865: goto out;
1.14 markus 866: }
867: /* Compute packet length without padding (add checksum, remove padding). */
1.201 markus 868: len = sshbuf_len(state->outgoing_packet) + 4 - 8;
1.14 markus 869:
1.32 markus 870: /* Insert padding. Initialized to zero in packet_start1() */
1.14 markus 871: padding = 8 - len % 8;
1.235 djm 872: if (!cipher_ctx_is_plaintext(state->send_context)) {
1.201 markus 873: cp = sshbuf_mutable_ptr(state->outgoing_packet);
874: if (cp == NULL) {
875: r = SSH_ERR_INTERNAL_ERROR;
876: goto out;
1.14 markus 877: }
1.201 markus 878: arc4random_buf(cp + 8 - padding, padding);
1.14 markus 879: }
1.201 markus 880: if ((r = sshbuf_consume(state->outgoing_packet, 8 - padding)) != 0)
881: goto out;
1.14 markus 882:
883: /* Add check bytes. */
1.201 markus 884: checksum = ssh_crc32(sshbuf_ptr(state->outgoing_packet),
885: sshbuf_len(state->outgoing_packet));
886: POKE_U32(buf, checksum);
887: if ((r = sshbuf_put(state->outgoing_packet, buf, 4)) != 0)
888: goto out;
1.1 deraadt 889:
890: #ifdef PACKET_DEBUG
1.14 markus 891: fprintf(stderr, "packet_send plain: ");
1.201 markus 892: sshbuf_dump(state->outgoing_packet, stderr);
1.1 deraadt 893: #endif
894:
1.14 markus 895: /* Append to output. */
1.201 markus 896: POKE_U32(buf, len);
897: if ((r = sshbuf_put(state->output, buf, 4)) != 0)
898: goto out;
899: if ((r = sshbuf_reserve(state->output,
900: sshbuf_len(state->outgoing_packet), &cp)) != 0)
901: goto out;
1.235 djm 902: if ((r = cipher_crypt(state->send_context, 0, cp,
1.201 markus 903: sshbuf_ptr(state->outgoing_packet),
904: sshbuf_len(state->outgoing_packet), 0, 0)) != 0)
905: goto out;
1.14 markus 906:
1.1 deraadt 907: #ifdef PACKET_DEBUG
1.14 markus 908: fprintf(stderr, "encrypted: ");
1.201 markus 909: sshbuf_dump(state->output, stderr);
1.1 deraadt 910: #endif
1.201 markus 911: state->p_send.packets++;
912: state->p_send.bytes += len +
913: sshbuf_len(state->outgoing_packet);
914: sshbuf_reset(state->outgoing_packet);
1.1 deraadt 915:
1.16 markus 916: /*
1.120 djm 917: * Note that the packet is now only buffered in output. It won't be
1.205 djm 918: * actually sent until ssh_packet_write_wait or ssh_packet_write_poll
919: * is called.
1.16 markus 920: */
1.201 markus 921: r = 0;
922: out:
923: return r;
1.1 deraadt 924: }
925:
1.201 markus 926: int
927: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 928: {
1.201 markus 929: struct session_state *state = ssh->state;
930: struct sshenc *enc;
931: struct sshmac *mac;
932: struct sshcomp *comp;
1.235 djm 933: struct sshcipher_ctx **ccp;
1.236 markus 934: struct packet_state *ps;
1.105 markus 935: u_int64_t *max_blocks;
1.236 markus 936: const char *wmsg, *dir;
1.197 djm 937: int r, crypt_type;
1.57 markus 938:
1.100 markus 939: debug2("set_newkeys: mode %d", mode);
1.57 markus 940:
1.88 markus 941: if (mode == MODE_OUT) {
1.236 markus 942: dir = "output";
1.235 djm 943: ccp = &state->send_context;
1.115 avsm 944: crypt_type = CIPHER_ENCRYPT;
1.236 markus 945: ps = &state->p_send;
1.201 markus 946: max_blocks = &state->max_blocks_out;
1.88 markus 947: } else {
1.236 markus 948: dir = "input";
1.235 djm 949: ccp = &state->receive_context;
1.115 avsm 950: crypt_type = CIPHER_DECRYPT;
1.236 markus 951: ps = &state->p_read;
1.201 markus 952: max_blocks = &state->max_blocks_in;
1.88 markus 953: }
1.201 markus 954: if (state->newkeys[mode] != NULL) {
1.236 markus 955: debug("%s: rekeying after %llu %s blocks"
956: " (%llu bytes total)", __func__,
957: (unsigned long long)ps->blocks, dir,
958: (unsigned long long)ps->bytes);
1.235 djm 959: cipher_free(*ccp);
960: *ccp = NULL;
1.201 markus 961: enc = &state->newkeys[mode]->enc;
962: mac = &state->newkeys[mode]->mac;
963: comp = &state->newkeys[mode]->comp;
1.148 pvalchev 964: mac_clear(mac);
1.192 djm 965: explicit_bzero(enc->iv, enc->iv_len);
966: explicit_bzero(enc->key, enc->key_len);
967: explicit_bzero(mac->key, mac->key_len);
1.186 djm 968: free(enc->name);
969: free(enc->iv);
970: free(enc->key);
971: free(mac->name);
972: free(mac->key);
973: free(comp->name);
1.201 markus 974: free(state->newkeys[mode]);
1.57 markus 975: }
1.236 markus 976: /* note that both bytes and the seqnr are not reset */
977: ps->packets = ps->blocks = 0;
1.201 markus 978: /* move newkeys from kex to state */
979: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
980: return SSH_ERR_INTERNAL_ERROR;
981: ssh->kex->newkeys[mode] = NULL;
982: enc = &state->newkeys[mode]->enc;
983: mac = &state->newkeys[mode]->mac;
984: comp = &state->newkeys[mode]->comp;
985: if (cipher_authlen(enc->cipher) == 0) {
986: if ((r = mac_init(mac)) != 0)
987: return r;
988: }
989: mac->enabled = 1;
1.57 markus 990: DBG(debug("cipher_init_context: %d", mode));
1.235 djm 991: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 992: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 993: return r;
994: if (!state->cipher_warning_done &&
1.235 djm 995: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 996: error("Warning: %s", wmsg);
997: state->cipher_warning_done = 1;
998: }
1.91 markus 999: /* Deleting the keys does not gain extra security */
1.192 djm 1000: /* explicit_bzero(enc->iv, enc->block_size);
1001: explicit_bzero(enc->key, enc->key_len);
1002: explicit_bzero(mac->key, mac->key_len); */
1.241 djm 1003: if ((comp->type == COMP_ZLIB ||
1004: (comp->type == COMP_DELAYED &&
1005: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 1006: if ((r = ssh_packet_init_compression(ssh)) < 0)
1007: return r;
1008: if (mode == MODE_OUT) {
1009: if ((r = start_compression_out(ssh, 6)) != 0)
1010: return r;
1011: } else {
1012: if ((r = start_compression_in(ssh)) != 0)
1013: return r;
1014: }
1.57 markus 1015: comp->enabled = 1;
1016: }
1.109 markus 1017: /*
1018: * The 2^(blocksize*2) limit is too expensive for 3DES,
1019: * blowfish, etc, so enforce a 1GB limit for small blocksizes.
1020: */
1021: if (enc->block_size >= 16)
1022: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
1023: else
1024: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 1025: if (state->rekey_limit)
1.237 deraadt 1026: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 1027: state->rekey_limit / enc->block_size);
1.227 djm 1028: debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1.201 markus 1029: return 0;
1.57 markus 1030: }
1031:
1.228 djm 1032: #define MAX_PACKETS (1U<<31)
1033: static int
1034: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
1035: {
1036: struct session_state *state = ssh->state;
1037: u_int32_t out_blocks;
1038:
1039: /* XXX client can't cope with rekeying pre-auth */
1040: if (!state->after_authentication)
1041: return 0;
1042:
1043: /* Haven't keyed yet or KEX in progress. */
1044: if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
1045: return 0;
1046:
1047: /* Peer can't rekey */
1048: if (ssh->compat & SSH_BUG_NOREKEY)
1049: return 0;
1050:
1051: /*
1052: * Permit one packet in or out per rekey - this allows us to
1053: * make progress when rekey limits are very small.
1054: */
1055: if (state->p_send.packets == 0 && state->p_read.packets == 0)
1056: return 0;
1057:
1058: /* Time-based rekeying */
1059: if (state->rekey_interval != 0 &&
1.244 dtucker 1060: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 1061: return 1;
1062:
1063: /* Always rekey when MAX_PACKETS sent in either direction */
1064: if (state->p_send.packets > MAX_PACKETS ||
1065: state->p_read.packets > MAX_PACKETS)
1066: return 1;
1067:
1068: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 1069: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 1070: state->newkeys[MODE_OUT]->enc.block_size);
1071: return (state->max_blocks_out &&
1072: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
1073: (state->max_blocks_in &&
1074: (state->p_read.blocks > state->max_blocks_in));
1075: }
1076:
1.16 markus 1077: /*
1.118 markus 1078: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 1079: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 1080: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
1081: */
1.201 markus 1082: static int
1083: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 1084: {
1.201 markus 1085: struct session_state *state = ssh->state;
1086: struct sshcomp *comp = NULL;
1087: int r, mode;
1.118 markus 1088:
1089: /*
1090: * Remember that we are past the authentication step, so rekeying
1091: * with COMP_DELAYED will turn on compression immediately.
1092: */
1.201 markus 1093: state->after_authentication = 1;
1.118 markus 1094: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 1095: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 1096: if (state->newkeys[mode] == NULL)
1.145 markus 1097: continue;
1.201 markus 1098: comp = &state->newkeys[mode]->comp;
1.118 markus 1099: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 1100: if ((r = ssh_packet_init_compression(ssh)) != 0)
1101: return r;
1102: if (mode == MODE_OUT) {
1103: if ((r = start_compression_out(ssh, 6)) != 0)
1104: return r;
1105: } else {
1106: if ((r = start_compression_in(ssh)) != 0)
1107: return r;
1108: }
1.118 markus 1109: comp->enabled = 1;
1110: }
1111: }
1.201 markus 1112: return 0;
1.118 markus 1113: }
1114:
1.226 djm 1115: /* Used to mute debug logging for noisy packet types */
1.242 markus 1116: int
1.226 djm 1117: ssh_packet_log_type(u_char type)
1118: {
1119: switch (type) {
1120: case SSH2_MSG_CHANNEL_DATA:
1121: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1122: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1123: return 0;
1124: default:
1125: return 1;
1126: }
1127: }
1128:
1.118 markus 1129: /*
1.25 markus 1130: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1131: */
1.201 markus 1132: int
1133: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1134: {
1.201 markus 1135: struct session_state *state = ssh->state;
1.200 markus 1136: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1137: u_char tmp, padlen, pad = 0;
1.201 markus 1138: u_int authlen = 0, aadlen = 0;
1139: u_int len;
1140: struct sshenc *enc = NULL;
1141: struct sshmac *mac = NULL;
1142: struct sshcomp *comp = NULL;
1143: int r, block_size;
1144:
1145: if (state->newkeys[MODE_OUT] != NULL) {
1146: enc = &state->newkeys[MODE_OUT]->enc;
1147: mac = &state->newkeys[MODE_OUT]->mac;
1148: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1149: /* disable mac for authenticated encryption */
1150: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1151: mac = NULL;
1.25 markus 1152: }
1.88 markus 1153: block_size = enc ? enc->block_size : 8;
1.180 markus 1154: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1155:
1.201 markus 1156: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1157: if (ssh_packet_log_type(type))
1158: debug3("send packet: type %u", type);
1.25 markus 1159: #ifdef PACKET_DEBUG
1160: fprintf(stderr, "plain: ");
1.201 markus 1161: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1162: #endif
1163:
1164: if (comp && comp->enabled) {
1.201 markus 1165: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1166: /* skip header, compress only payload */
1.201 markus 1167: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1168: goto out;
1169: sshbuf_reset(state->compression_buffer);
1170: if ((r = compress_buffer(ssh, state->outgoing_packet,
1171: state->compression_buffer)) != 0)
1172: goto out;
1173: sshbuf_reset(state->outgoing_packet);
1174: if ((r = sshbuf_put(state->outgoing_packet,
1175: "\0\0\0\0\0", 5)) != 0 ||
1176: (r = sshbuf_putb(state->outgoing_packet,
1177: state->compression_buffer)) != 0)
1178: goto out;
1179: DBG(debug("compression: raw %d compressed %zd", len,
1180: sshbuf_len(state->outgoing_packet)));
1.25 markus 1181: }
1182:
1183: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1184: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1185:
1186: /*
1187: * calc size of padding, alloc space, get random data,
1188: * minimum padding is 4 bytes
1189: */
1.178 markus 1190: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1191: padlen = block_size - (len % block_size);
1192: if (padlen < 4)
1193: padlen += block_size;
1.201 markus 1194: if (state->extra_pad) {
1.233 djm 1195: tmp = state->extra_pad;
1.201 markus 1196: state->extra_pad =
1.237 deraadt 1197: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1198: /* check if roundup overflowed */
1199: if (state->extra_pad < tmp)
1200: return SSH_ERR_INVALID_ARGUMENT;
1201: tmp = (len + padlen) % state->extra_pad;
1202: /* Check whether pad calculation below will underflow */
1203: if (tmp > state->extra_pad)
1204: return SSH_ERR_INVALID_ARGUMENT;
1205: pad = state->extra_pad - tmp;
1.193 djm 1206: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1207: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1208: tmp = padlen;
1.71 markus 1209: padlen += pad;
1.233 djm 1210: /* Check whether padlen calculation overflowed */
1211: if (padlen < tmp)
1212: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1213: state->extra_pad = 0;
1.71 markus 1214: }
1.201 markus 1215: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1216: goto out;
1.235 djm 1217: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1218: /* random padding */
1.201 markus 1219: arc4random_buf(cp, padlen);
1.32 markus 1220: } else {
1221: /* clear padding */
1.192 djm 1222: explicit_bzero(cp, padlen);
1.25 markus 1223: }
1.178 markus 1224: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1225: len = sshbuf_len(state->outgoing_packet);
1226: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1227: if (cp == NULL) {
1228: r = SSH_ERR_INTERNAL_ERROR;
1229: goto out;
1230: }
1.25 markus 1231: /* packet_length includes payload, padding and padding length field */
1.201 markus 1232: POKE_U32(cp, len - 4);
1.89 markus 1233: cp[4] = padlen;
1.178 markus 1234: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1235: len, padlen, aadlen));
1.25 markus 1236:
1237: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1238: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1239: if ((r = mac_compute(mac, state->p_send.seqnr,
1240: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1241: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1242: goto out;
1243: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1244: }
1245: /* encrypt packet and append to output buffer. */
1.201 markus 1246: if ((r = sshbuf_reserve(state->output,
1247: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1248: goto out;
1.235 djm 1249: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1250: sshbuf_ptr(state->outgoing_packet),
1251: len - aadlen, aadlen, authlen)) != 0)
1252: goto out;
1.25 markus 1253: /* append unencrypted MAC */
1.178 markus 1254: if (mac && mac->enabled) {
1255: if (mac->etm) {
1256: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1257: if ((r = mac_compute(mac, state->p_send.seqnr,
1258: cp, len, macbuf, sizeof(macbuf))) != 0)
1259: goto out;
1.178 markus 1260: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1261: state->p_send.seqnr));
1.178 markus 1262: }
1.201 markus 1263: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1264: goto out;
1.178 markus 1265: }
1.25 markus 1266: #ifdef PACKET_DEBUG
1267: fprintf(stderr, "encrypted: ");
1.201 markus 1268: sshbuf_dump(state->output, stderr);
1.25 markus 1269: #endif
1.29 markus 1270: /* increment sequence number for outgoing packets */
1.201 markus 1271: if (++state->p_send.seqnr == 0)
1.106 itojun 1272: logit("outgoing seqnr wraps around");
1.201 markus 1273: if (++state->p_send.packets == 0)
1274: if (!(ssh->compat & SSH_BUG_NOREKEY))
1275: return SSH_ERR_NEED_REKEY;
1276: state->p_send.blocks += len / block_size;
1277: state->p_send.bytes += len;
1278: sshbuf_reset(state->outgoing_packet);
1.25 markus 1279:
1.57 markus 1280: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1281: r = ssh_set_newkeys(ssh, MODE_OUT);
1282: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1283: r = ssh_packet_enable_delayed_compress(ssh);
1284: else
1285: r = 0;
1286: out:
1287: return r;
1.25 markus 1288: }
1289:
1.228 djm 1290: /* returns non-zero if the specified packet type is usec by KEX */
1291: static int
1292: ssh_packet_type_is_kex(u_char type)
1293: {
1294: return
1295: type >= SSH2_MSG_TRANSPORT_MIN &&
1296: type <= SSH2_MSG_TRANSPORT_MAX &&
1297: type != SSH2_MSG_SERVICE_REQUEST &&
1298: type != SSH2_MSG_SERVICE_ACCEPT &&
1299: type != SSH2_MSG_EXT_INFO;
1300: }
1301:
1.201 markus 1302: int
1303: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1304: {
1.201 markus 1305: struct session_state *state = ssh->state;
1.105 markus 1306: struct packet *p;
1.201 markus 1307: u_char type;
1.228 djm 1308: int r, need_rekey;
1.105 markus 1309:
1.228 djm 1310: if (sshbuf_len(state->outgoing_packet) < 6)
1311: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1312: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1313: need_rekey = !ssh_packet_type_is_kex(type) &&
1314: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1315:
1.228 djm 1316: /*
1317: * During rekeying we can only send key exchange messages.
1318: * Queue everything else.
1319: */
1320: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1321: if (need_rekey)
1322: debug3("%s: rekex triggered", __func__);
1323: debug("enqueue packet: %u", type);
1324: p = calloc(1, sizeof(*p));
1325: if (p == NULL)
1326: return SSH_ERR_ALLOC_FAIL;
1327: p->type = type;
1328: p->payload = state->outgoing_packet;
1329: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1330: state->outgoing_packet = sshbuf_new();
1331: if (state->outgoing_packet == NULL)
1332: return SSH_ERR_ALLOC_FAIL;
1333: if (need_rekey) {
1334: /*
1335: * This packet triggered a rekey, so send the
1336: * KEXINIT now.
1337: * NB. reenters this function via kex_start_rekex().
1338: */
1339: return kex_start_rekex(ssh);
1.105 markus 1340: }
1.228 djm 1341: return 0;
1.105 markus 1342: }
1343:
1344: /* rekeying starts with sending KEXINIT */
1345: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1346: state->rekeying = 1;
1.105 markus 1347:
1.201 markus 1348: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1349: return r;
1.105 markus 1350:
1351: /* after a NEWKEYS message we can send the complete queue */
1352: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1353: state->rekeying = 0;
1354: state->rekey_time = monotime();
1355: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1356: type = p->type;
1.228 djm 1357: /*
1358: * If this packet triggers a rekex, then skip the
1359: * remaining packets in the queue for now.
1360: * NB. re-enters this function via kex_start_rekex.
1361: */
1362: if (ssh_packet_need_rekeying(ssh,
1363: sshbuf_len(p->payload))) {
1364: debug3("%s: queued packet triggered rekex",
1365: __func__);
1366: return kex_start_rekex(ssh);
1367: }
1.105 markus 1368: debug("dequeue packet: %u", type);
1.201 markus 1369: sshbuf_free(state->outgoing_packet);
1370: state->outgoing_packet = p->payload;
1371: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1372: memset(p, 0, sizeof(*p));
1.186 djm 1373: free(p);
1.201 markus 1374: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1375: return r;
1.105 markus 1376: }
1377: }
1.201 markus 1378: return 0;
1.25 markus 1379: }
1380:
1381: /*
1.16 markus 1382: * Waits until a packet has been received, and returns its type. Note that
1383: * no other data is processed until this returns, so this function should not
1384: * be used during the interactive session.
1385: */
1.1 deraadt 1386:
1.2 provos 1387: int
1.201 markus 1388: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1389: {
1.201 markus 1390: struct session_state *state = ssh->state;
1.222 markus 1391: int len, r, ms_remain;
1.56 millert 1392: fd_set *setp;
1.14 markus 1393: char buf[8192];
1.155 deraadt 1394: struct timeval timeout, start, *timeoutp = NULL;
1395:
1.25 markus 1396: DBG(debug("packet_read()"));
1.14 markus 1397:
1.214 deraadt 1398: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1399: NFDBITS), sizeof(fd_mask));
1.201 markus 1400: if (setp == NULL)
1401: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1402:
1.205 djm 1403: /*
1404: * Since we are blocking, ensure that all written packets have
1405: * been sent.
1406: */
1.210 markus 1407: if ((r = ssh_packet_write_wait(ssh)) != 0)
1408: goto out;
1.14 markus 1409:
1410: /* Stay in the loop until we have received a complete packet. */
1411: for (;;) {
1412: /* Try to read a packet from the buffer. */
1.201 markus 1413: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1414: if (r != 0)
1415: break;
1.62 markus 1416: if (!compat20 && (
1.201 markus 1417: *typep == SSH_SMSG_SUCCESS
1418: || *typep == SSH_SMSG_FAILURE
1419: || *typep == SSH_CMSG_EOF
1420: || *typep == SSH_CMSG_EXIT_CONFIRMATION))
1421: if ((r = sshpkt_get_end(ssh)) != 0)
1422: break;
1.14 markus 1423: /* If we got a packet, return it. */
1.201 markus 1424: if (*typep != SSH_MSG_NONE)
1425: break;
1.16 markus 1426: /*
1427: * Otherwise, wait for some data to arrive, add it to the
1428: * buffer, and try again.
1429: */
1.201 markus 1430: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1431: NFDBITS) * sizeof(fd_mask));
1.201 markus 1432: FD_SET(state->connection_in, setp);
1.16 markus 1433:
1.201 markus 1434: if (state->packet_timeout_ms > 0) {
1435: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1436: timeoutp = &timeout;
1437: }
1.14 markus 1438: /* Wait for some data to arrive. */
1.154 dtucker 1439: for (;;) {
1.201 markus 1440: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1441: ms_to_timeval(&timeout, ms_remain);
1442: gettimeofday(&start, NULL);
1443: }
1.201 markus 1444: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1445: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1446: break;
1.161 andreas 1447: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1448: break;
1.201 markus 1449: if (state->packet_timeout_ms == -1)
1.154 dtucker 1450: continue;
1451: ms_subtract_diff(&start, &ms_remain);
1452: if (ms_remain <= 0) {
1.201 markus 1453: r = 0;
1.154 dtucker 1454: break;
1455: }
1456: }
1.246 djm 1457: if (r == 0) {
1458: r = SSH_ERR_CONN_TIMEOUT;
1459: goto out;
1460: }
1.14 markus 1461: /* Read data from the socket. */
1.222 markus 1462: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1463: if (len == 0) {
1464: r = SSH_ERR_CONN_CLOSED;
1465: goto out;
1466: }
1467: if (len < 0) {
1468: r = SSH_ERR_SYSTEM_ERROR;
1469: goto out;
1470: }
1.204 djm 1471:
1.14 markus 1472: /* Append it to the buffer. */
1.204 djm 1473: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1474: goto out;
1.14 markus 1475: }
1.210 markus 1476: out:
1.201 markus 1477: free(setp);
1478: return r;
1.1 deraadt 1479: }
1480:
1.77 djm 1481: int
1.201 markus 1482: ssh_packet_read(struct ssh *ssh)
1.77 djm 1483: {
1.201 markus 1484: u_char type;
1485: int r;
1486:
1487: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1488: fatal("%s: %s", __func__, ssh_err(r));
1489: return type;
1.77 djm 1490: }
1491:
1.16 markus 1492: /*
1493: * Waits until a packet has been received, verifies that its type matches
1494: * that given, and gives a fatal error and exits if there is a mismatch.
1495: */
1.1 deraadt 1496:
1.205 djm 1497: int
1498: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1499: {
1.205 djm 1500: int r;
1501: u_char type;
1.1 deraadt 1502:
1.205 djm 1503: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1504: return r;
1505: if (type != expected_type) {
1506: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1507: "Protocol error: expected packet type %d, got %d",
1.205 djm 1508: expected_type, type)) != 0)
1509: return r;
1510: return SSH_ERR_PROTOCOL_ERROR;
1511: }
1512: return 0;
1.1 deraadt 1513: }
1514:
1515: /* Checks if a full packet is available in the data received so far via
1.14 markus 1516: * packet_process_incoming. If so, reads the packet; otherwise returns
1517: * SSH_MSG_NONE. This does not wait for data from the connection.
1518: *
1.150 dtucker 1519: * SSH_MSG_DISCONNECT is handled specially here. Also,
1520: * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1521: * to higher levels.
1.14 markus 1522: */
1.1 deraadt 1523:
1.201 markus 1524: int
1525: ssh_packet_read_poll1(struct ssh *ssh, u_char *typep)
1.1 deraadt 1526: {
1.201 markus 1527: struct session_state *state = ssh->state;
1.40 markus 1528: u_int len, padded_len;
1.205 djm 1529: const char *emsg;
1.201 markus 1530: const u_char *cp;
1531: u_char *p;
1.40 markus 1532: u_int checksum, stored_checksum;
1.201 markus 1533: int r;
1534:
1535: *typep = SSH_MSG_NONE;
1.14 markus 1536:
1537: /* Check if input size is less than minimum packet size. */
1.201 markus 1538: if (sshbuf_len(state->input) < 4 + 8)
1539: return 0;
1.14 markus 1540: /* Get length of incoming packet. */
1.201 markus 1541: len = PEEK_U32(sshbuf_ptr(state->input));
1.205 djm 1542: if (len < 1 + 2 + 2 || len > 256 * 1024) {
1543: if ((r = sshpkt_disconnect(ssh, "Bad packet length %u",
1544: len)) != 0)
1545: return r;
1546: return SSH_ERR_CONN_CORRUPT;
1547: }
1.14 markus 1548: padded_len = (len + 8) & ~7;
1549:
1550: /* Check if the packet has been entirely received. */
1.201 markus 1551: if (sshbuf_len(state->input) < 4 + padded_len)
1552: return 0;
1.14 markus 1553:
1554: /* The entire packet is in buffer. */
1555:
1556: /* Consume packet length. */
1.201 markus 1557: if ((r = sshbuf_consume(state->input, 4)) != 0)
1558: goto out;
1.14 markus 1559:
1.62 markus 1560: /*
1561: * Cryptographic attack detector for ssh
1562: * (C)1998 CORE-SDI, Buenos Aires Argentina
1563: * Ariel Futoransky(futo@core-sdi.com)
1564: */
1.235 djm 1565: if (!cipher_ctx_is_plaintext(state->receive_context)) {
1.205 djm 1566: emsg = NULL;
1.201 markus 1567: switch (detect_attack(&state->deattack,
1568: sshbuf_ptr(state->input), padded_len)) {
1569: case DEATTACK_OK:
1570: break;
1.144 djm 1571: case DEATTACK_DETECTED:
1.205 djm 1572: emsg = "crc32 compensation attack detected";
1573: break;
1.144 djm 1574: case DEATTACK_DOS_DETECTED:
1.205 djm 1575: emsg = "deattack denial of service detected";
1576: break;
1.201 markus 1577: default:
1.205 djm 1578: emsg = "deattack error";
1579: break;
1580: }
1581: if (emsg != NULL) {
1582: error("%s", emsg);
1583: if ((r = sshpkt_disconnect(ssh, "%s", emsg)) != 0 ||
1584: (r = ssh_packet_write_wait(ssh)) != 0)
1585: return r;
1586: return SSH_ERR_CONN_CORRUPT;
1.144 djm 1587: }
1588: }
1.62 markus 1589:
1590: /* Decrypt data to incoming_packet. */
1.201 markus 1591: sshbuf_reset(state->incoming_packet);
1592: if ((r = sshbuf_reserve(state->incoming_packet, padded_len, &p)) != 0)
1593: goto out;
1.235 djm 1594: if ((r = cipher_crypt(state->receive_context, 0, p,
1.201 markus 1595: sshbuf_ptr(state->input), padded_len, 0, 0)) != 0)
1596: goto out;
1.62 markus 1597:
1.201 markus 1598: if ((r = sshbuf_consume(state->input, padded_len)) != 0)
1599: goto out;
1.1 deraadt 1600:
1601: #ifdef PACKET_DEBUG
1.14 markus 1602: fprintf(stderr, "read_poll plain: ");
1.201 markus 1603: sshbuf_dump(state->incoming_packet, stderr);
1.1 deraadt 1604: #endif
1605:
1.14 markus 1606: /* Compute packet checksum. */
1.201 markus 1607: checksum = ssh_crc32(sshbuf_ptr(state->incoming_packet),
1608: sshbuf_len(state->incoming_packet) - 4);
1.14 markus 1609:
1610: /* Skip padding. */
1.201 markus 1611: if ((r = sshbuf_consume(state->incoming_packet, 8 - len % 8)) != 0)
1612: goto out;
1.14 markus 1613:
1614: /* Test check bytes. */
1.205 djm 1615: if (len != sshbuf_len(state->incoming_packet)) {
1616: error("%s: len %d != sshbuf_len %zd", __func__,
1.201 markus 1617: len, sshbuf_len(state->incoming_packet));
1.205 djm 1618: if ((r = sshpkt_disconnect(ssh, "invalid packet length")) != 0 ||
1619: (r = ssh_packet_write_wait(ssh)) != 0)
1620: return r;
1621: return SSH_ERR_CONN_CORRUPT;
1622: }
1.14 markus 1623:
1.201 markus 1624: cp = sshbuf_ptr(state->incoming_packet) + len - 4;
1625: stored_checksum = PEEK_U32(cp);
1.205 djm 1626: if (checksum != stored_checksum) {
1627: error("Corrupted check bytes on input");
1628: if ((r = sshpkt_disconnect(ssh, "connection corrupted")) != 0 ||
1629: (r = ssh_packet_write_wait(ssh)) != 0)
1630: return r;
1631: return SSH_ERR_CONN_CORRUPT;
1632: }
1.201 markus 1633: if ((r = sshbuf_consume_end(state->incoming_packet, 4)) < 0)
1634: goto out;
1635:
1636: if (state->packet_compression) {
1637: sshbuf_reset(state->compression_buffer);
1638: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1639: state->compression_buffer)) != 0)
1640: goto out;
1641: sshbuf_reset(state->incoming_packet);
1642: if ((r = sshbuf_putb(state->incoming_packet,
1643: state->compression_buffer)) != 0)
1644: goto out;
1645: }
1646: state->p_read.packets++;
1647: state->p_read.bytes += padded_len + 4;
1648: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1649: goto out;
1.205 djm 1650: if (*typep < SSH_MSG_MIN || *typep > SSH_MSG_MAX) {
1651: error("Invalid ssh1 packet type: %d", *typep);
1652: if ((r = sshpkt_disconnect(ssh, "invalid packet type")) != 0 ||
1653: (r = ssh_packet_write_wait(ssh)) != 0)
1654: return r;
1655: return SSH_ERR_PROTOCOL_ERROR;
1656: }
1.201 markus 1657: r = 0;
1658: out:
1659: return r;
1.1 deraadt 1660: }
1.14 markus 1661:
1.242 markus 1662: static int
1663: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1664: {
1665: struct session_state *state = ssh->state;
1666: const u_char *cp;
1667: size_t need;
1668: int r;
1669:
1670: if (ssh->kex)
1671: return SSH_ERR_INTERNAL_ERROR;
1672: *typep = SSH_MSG_NONE;
1673: cp = sshbuf_ptr(state->input);
1674: if (state->packlen == 0) {
1675: if (sshbuf_len(state->input) < 4 + 1)
1676: return 0; /* packet is incomplete */
1677: state->packlen = PEEK_U32(cp);
1678: if (state->packlen < 4 + 1 ||
1679: state->packlen > PACKET_MAX_SIZE)
1680: return SSH_ERR_MESSAGE_INCOMPLETE;
1681: }
1682: need = state->packlen + 4;
1683: if (sshbuf_len(state->input) < need)
1684: return 0; /* packet is incomplete */
1685: sshbuf_reset(state->incoming_packet);
1686: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1687: state->packlen)) != 0 ||
1688: (r = sshbuf_consume(state->input, need)) != 0 ||
1689: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1690: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1691: return r;
1692: if (ssh_packet_log_type(*typep))
1693: debug3("%s: type %u", __func__, *typep);
1694: /* sshbuf_dump(state->incoming_packet, stderr); */
1695: /* reset for next packet */
1696: state->packlen = 0;
1697: return r;
1698: }
1699:
1.201 markus 1700: int
1701: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1702: {
1.201 markus 1703: struct session_state *state = ssh->state;
1.40 markus 1704: u_int padlen, need;
1.231 djm 1705: u_char *cp;
1.201 markus 1706: u_int maclen, aadlen = 0, authlen = 0, block_size;
1707: struct sshenc *enc = NULL;
1708: struct sshmac *mac = NULL;
1709: struct sshcomp *comp = NULL;
1.200 markus 1710: int r;
1.201 markus 1711:
1.242 markus 1712: if (state->mux)
1713: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1714:
1.201 markus 1715: *typep = SSH_MSG_NONE;
1716:
1717: if (state->packet_discard)
1718: return 0;
1719:
1720: if (state->newkeys[MODE_IN] != NULL) {
1721: enc = &state->newkeys[MODE_IN]->enc;
1722: mac = &state->newkeys[MODE_IN]->mac;
1723: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1724: /* disable mac for authenticated encryption */
1725: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1726: mac = NULL;
1.25 markus 1727: }
1728: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1729: block_size = enc ? enc->block_size : 8;
1.180 markus 1730: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1731:
1.201 markus 1732: if (aadlen && state->packlen == 0) {
1.235 djm 1733: if (cipher_get_length(state->receive_context,
1.201 markus 1734: &state->packlen, state->p_read.seqnr,
1735: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1736: return 0;
1737: if (state->packlen < 1 + 4 ||
1738: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1739: #ifdef PACKET_DEBUG
1.201 markus 1740: sshbuf_dump(state->input, stderr);
1.178 markus 1741: #endif
1.201 markus 1742: logit("Bad packet length %u.", state->packlen);
1743: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1744: return r;
1.217 djm 1745: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1746: }
1.201 markus 1747: sshbuf_reset(state->incoming_packet);
1748: } else if (state->packlen == 0) {
1.25 markus 1749: /*
1750: * check if input size is less than the cipher block size,
1751: * decrypt first block and extract length of incoming packet
1752: */
1.201 markus 1753: if (sshbuf_len(state->input) < block_size)
1754: return 0;
1755: sshbuf_reset(state->incoming_packet);
1756: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1757: &cp)) != 0)
1758: goto out;
1.235 djm 1759: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1760: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1761: block_size, 0, 0)) != 0)
1762: goto out;
1763: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1764: if (state->packlen < 1 + 4 ||
1765: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1766: #ifdef PACKET_DEBUG
1.201 markus 1767: fprintf(stderr, "input: \n");
1768: sshbuf_dump(state->input, stderr);
1769: fprintf(stderr, "incoming_packet: \n");
1770: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1771: #endif
1.201 markus 1772: logit("Bad packet length %u.", state->packlen);
1.234 markus 1773: return ssh_packet_start_discard(ssh, enc, mac, 0,
1774: PACKET_MAX_SIZE);
1.25 markus 1775: }
1.201 markus 1776: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1777: goto out;
1.25 markus 1778: }
1.201 markus 1779: DBG(debug("input: packet len %u", state->packlen+4));
1780:
1.178 markus 1781: if (aadlen) {
1782: /* only the payload is encrypted */
1.201 markus 1783: need = state->packlen;
1.178 markus 1784: } else {
1785: /*
1786: * the payload size and the payload are encrypted, but we
1787: * have a partial packet of block_size bytes
1788: */
1.201 markus 1789: need = 4 + state->packlen - block_size;
1.178 markus 1790: }
1.180 markus 1791: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1792: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1793: if (need % block_size != 0) {
1794: logit("padding error: need %d block %d mod %d",
1.25 markus 1795: need, block_size, need % block_size);
1.234 markus 1796: return ssh_packet_start_discard(ssh, enc, mac, 0,
1797: PACKET_MAX_SIZE - block_size);
1.158 markus 1798: }
1.25 markus 1799: /*
1800: * check if the entire packet has been received and
1.178 markus 1801: * decrypt into incoming_packet:
1802: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1803: * 'need' bytes are encrypted, followed by either
1804: * 'authlen' bytes of authentication tag or
1.178 markus 1805: * 'maclen' bytes of message authentication code.
1.25 markus 1806: */
1.201 markus 1807: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1808: return 0; /* packet is incomplete */
1.25 markus 1809: #ifdef PACKET_DEBUG
1810: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1811: sshbuf_dump(state->input, stderr);
1.25 markus 1812: #endif
1.231 djm 1813: /* EtM: check mac over encrypted input */
1.201 markus 1814: if (mac && mac->enabled && mac->etm) {
1.231 djm 1815: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1816: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1817: sshbuf_ptr(state->input) + aadlen + need + authlen,
1818: maclen)) != 0) {
1819: if (r == SSH_ERR_MAC_INVALID)
1820: logit("Corrupted MAC on input.");
1.201 markus 1821: goto out;
1.231 djm 1822: }
1.201 markus 1823: }
1824: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1825: &cp)) != 0)
1826: goto out;
1.235 djm 1827: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1828: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1829: goto out;
1830: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1831: goto out;
1.29 markus 1832: if (mac && mac->enabled) {
1.231 djm 1833: /* Not EtM: check MAC over cleartext */
1834: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1835: sshbuf_ptr(state->incoming_packet),
1836: sshbuf_len(state->incoming_packet),
1837: sshbuf_ptr(state->input), maclen)) != 0) {
1838: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1839: goto out;
1.159 markus 1840: logit("Corrupted MAC on input.");
1.247 ! markus 1841: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1842: return SSH_ERR_INTERNAL_ERROR;
1843: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1844: sshbuf_len(state->incoming_packet),
1.247 ! markus 1845: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1846: }
1.231 djm 1847: /* Remove MAC from input buffer */
1.201 markus 1848: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1849: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1850: goto out;
1.25 markus 1851: }
1.77 djm 1852: if (seqnr_p != NULL)
1.201 markus 1853: *seqnr_p = state->p_read.seqnr;
1854: if (++state->p_read.seqnr == 0)
1.106 itojun 1855: logit("incoming seqnr wraps around");
1.201 markus 1856: if (++state->p_read.packets == 0)
1857: if (!(ssh->compat & SSH_BUG_NOREKEY))
1858: return SSH_ERR_NEED_REKEY;
1859: state->p_read.blocks += (state->packlen + 4) / block_size;
1860: state->p_read.bytes += state->packlen + 4;
1.25 markus 1861:
1862: /* get padlen */
1.201 markus 1863: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1864: DBG(debug("input: padlen %d", padlen));
1.205 djm 1865: if (padlen < 4) {
1866: if ((r = sshpkt_disconnect(ssh,
1867: "Corrupted padlen %d on input.", padlen)) != 0 ||
1868: (r = ssh_packet_write_wait(ssh)) != 0)
1869: return r;
1870: return SSH_ERR_CONN_CORRUPT;
1871: }
1.25 markus 1872:
1873: /* skip packet size + padlen, discard padding */
1.201 markus 1874: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1875: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1876: goto out;
1.25 markus 1877:
1.201 markus 1878: DBG(debug("input: len before de-compress %zd",
1879: sshbuf_len(state->incoming_packet)));
1.25 markus 1880: if (comp && comp->enabled) {
1.201 markus 1881: sshbuf_reset(state->compression_buffer);
1882: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1883: state->compression_buffer)) != 0)
1884: goto out;
1885: sshbuf_reset(state->incoming_packet);
1886: if ((r = sshbuf_putb(state->incoming_packet,
1887: state->compression_buffer)) != 0)
1888: goto out;
1889: DBG(debug("input: len after de-compress %zd",
1890: sshbuf_len(state->incoming_packet)));
1.25 markus 1891: }
1892: /*
1893: * get packet type, implies consume.
1894: * return length of payload (without type field)
1895: */
1.201 markus 1896: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1897: goto out;
1.226 djm 1898: if (ssh_packet_log_type(*typep))
1899: debug3("receive packet: type %u", *typep);
1.205 djm 1900: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1901: if ((r = sshpkt_disconnect(ssh,
1902: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1903: (r = ssh_packet_write_wait(ssh)) != 0)
1904: return r;
1905: return SSH_ERR_PROTOCOL_ERROR;
1906: }
1.243 djm 1907: if (state->hook_in != NULL &&
1908: (r = state->hook_in(ssh, state->incoming_packet, typep,
1909: state->hook_in_ctx)) != 0)
1910: return r;
1.238 markus 1911: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1912: r = ssh_packet_enable_delayed_compress(ssh);
1913: else
1914: r = 0;
1.25 markus 1915: #ifdef PACKET_DEBUG
1.201 markus 1916: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1917: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1918: #endif
1.62 markus 1919: /* reset for next packet */
1.201 markus 1920: state->packlen = 0;
1.228 djm 1921:
1922: /* do we need to rekey? */
1923: if (ssh_packet_need_rekeying(ssh, 0)) {
1924: debug3("%s: rekex triggered", __func__);
1925: if ((r = kex_start_rekex(ssh)) != 0)
1926: return r;
1927: }
1.201 markus 1928: out:
1929: return r;
1.25 markus 1930: }
1931:
1932: int
1.201 markus 1933: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1934: {
1.201 markus 1935: struct session_state *state = ssh->state;
1.96 deraadt 1936: u_int reason, seqnr;
1.201 markus 1937: int r;
1938: u_char *msg;
1.62 markus 1939:
1.25 markus 1940: for (;;) {
1.201 markus 1941: msg = NULL;
1.62 markus 1942: if (compat20) {
1.201 markus 1943: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1944: if (r != 0)
1945: return r;
1946: if (*typep) {
1947: state->keep_alive_timeouts = 0;
1948: DBG(debug("received packet type %d", *typep));
1.153 djm 1949: }
1.201 markus 1950: switch (*typep) {
1.150 dtucker 1951: case SSH2_MSG_IGNORE:
1.151 dtucker 1952: debug3("Received SSH2_MSG_IGNORE");
1.150 dtucker 1953: break;
1.25 markus 1954: case SSH2_MSG_DEBUG:
1.201 markus 1955: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1956: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1957: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1.219 mmcc 1958: free(msg);
1.201 markus 1959: return r;
1960: }
1.25 markus 1961: debug("Remote: %.900s", msg);
1.186 djm 1962: free(msg);
1.25 markus 1963: break;
1964: case SSH2_MSG_DISCONNECT:
1.201 markus 1965: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1966: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1967: return r;
1.182 djm 1968: /* Ignore normal client exit notifications */
1.201 markus 1969: do_log2(ssh->state->server_side &&
1.182 djm 1970: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1971: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1.220 djm 1972: "Received disconnect from %s port %d:"
1973: "%u: %.400s", ssh_remote_ipaddr(ssh),
1974: ssh_remote_port(ssh), reason, msg);
1.186 djm 1975: free(msg);
1.201 markus 1976: return SSH_ERR_DISCONNECTED;
1.84 markus 1977: case SSH2_MSG_UNIMPLEMENTED:
1.201 markus 1978: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1979: return r;
1.96 deraadt 1980: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1981: seqnr);
1.150 dtucker 1982: break;
1.25 markus 1983: default:
1.201 markus 1984: return 0;
1.48 stevesk 1985: }
1.25 markus 1986: } else {
1.201 markus 1987: r = ssh_packet_read_poll1(ssh, typep);
1988: switch (*typep) {
1.188 djm 1989: case SSH_MSG_NONE:
1990: return SSH_MSG_NONE;
1.25 markus 1991: case SSH_MSG_IGNORE:
1992: break;
1993: case SSH_MSG_DEBUG:
1.201 markus 1994: if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1995: return r;
1.25 markus 1996: debug("Remote: %.900s", msg);
1.186 djm 1997: free(msg);
1.25 markus 1998: break;
1999: case SSH_MSG_DISCONNECT:
1.201 markus 2000: if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
2001: return r;
1.220 djm 2002: error("Received disconnect from %s port %d: "
2003: "%.400s", ssh_remote_ipaddr(ssh),
2004: ssh_remote_port(ssh), msg);
1.201 markus 2005: free(msg);
2006: return SSH_ERR_DISCONNECTED;
1.25 markus 2007: default:
1.201 markus 2008: DBG(debug("received packet type %d", *typep));
2009: return 0;
1.48 stevesk 2010: }
1.25 markus 2011: }
2012: }
2013: }
2014:
1.16 markus 2015: /*
2016: * Buffers the given amount of input characters. This is intended to be used
2017: * together with packet_read_poll.
2018: */
1.1 deraadt 2019:
1.204 djm 2020: int
1.201 markus 2021: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 2022: {
1.201 markus 2023: struct session_state *state = ssh->state;
2024: int r;
2025:
2026: if (state->packet_discard) {
2027: state->keep_alive_timeouts = 0; /* ?? */
2028: if (len >= state->packet_discard) {
2029: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 2030: return r;
1.201 markus 2031: }
2032: state->packet_discard -= len;
1.204 djm 2033: return 0;
1.159 markus 2034: }
1.201 markus 2035: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 2036: return r;
2037:
2038: return 0;
1.28 markus 2039: }
2040:
2041: int
1.201 markus 2042: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 2043: {
1.201 markus 2044: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 2045: }
2046:
1.16 markus 2047: /*
2048: * Sends a diagnostic message from the server to the client. This message
2049: * can be sent at any time (but not while constructing another message). The
2050: * message is printed immediately, but only if the client is being executed
2051: * in verbose mode. These messages are primarily intended to ease debugging
2052: * authentication problems. The length of the formatted message must not
1.205 djm 2053: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 2054: */
1.2 provos 2055: void
1.201 markus 2056: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 2057: {
1.14 markus 2058: char buf[1024];
2059: va_list args;
1.201 markus 2060: int r;
1.39 markus 2061:
1.201 markus 2062: if (compat20 && (ssh->compat & SSH_BUG_DEBUG))
1.39 markus 2063: return;
1.14 markus 2064:
2065: va_start(args, fmt);
2066: vsnprintf(buf, sizeof(buf), fmt, args);
2067: va_end(args);
2068:
1.30 markus 2069: if (compat20) {
1.201 markus 2070: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
2071: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
2072: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2073: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2074: (r = sshpkt_send(ssh)) != 0)
2075: fatal("%s: %s", __func__, ssh_err(r));
1.30 markus 2076: } else {
1.201 markus 2077: if ((r = sshpkt_start(ssh, SSH_MSG_DEBUG)) != 0 ||
2078: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2079: (r = sshpkt_send(ssh)) != 0)
2080: fatal("%s: %s", __func__, ssh_err(r));
1.30 markus 2081: }
1.205 djm 2082: if ((r = ssh_packet_write_wait(ssh)) != 0)
2083: fatal("%s: %s", __func__, ssh_err(r));
2084: }
2085:
1.245 djm 2086: static void
2087: fmt_connection_id(struct ssh *ssh, char *s, size_t l)
2088: {
2089: snprintf(s, l, "%.200s%s%s port %d",
2090: ssh->log_preamble ? ssh->log_preamble : "",
2091: ssh->log_preamble ? " " : "",
2092: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
2093: }
2094:
1.205 djm 2095: /*
2096: * Pretty-print connection-terminating errors and exit.
2097: */
2098: void
2099: sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
2100: {
1.245 djm 2101: char remote_id[512];
2102:
2103: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
2104:
1.205 djm 2105: switch (r) {
2106: case SSH_ERR_CONN_CLOSED:
1.245 djm 2107: logdie("Connection closed by %s", remote_id);
1.205 djm 2108: case SSH_ERR_CONN_TIMEOUT:
1.245 djm 2109: logdie("Connection %s %s timed out",
2110: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 2111: case SSH_ERR_DISCONNECTED:
1.245 djm 2112: logdie("Disconnected from %s", remote_id);
1.212 djm 2113: case SSH_ERR_SYSTEM_ERROR:
1.232 dtucker 2114: if (errno == ECONNRESET)
1.245 djm 2115: logdie("Connection reset by %s", remote_id);
1.213 djm 2116: /* FALLTHROUGH */
2117: case SSH_ERR_NO_CIPHER_ALG_MATCH:
2118: case SSH_ERR_NO_MAC_ALG_MATCH:
2119: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
2120: case SSH_ERR_NO_KEX_ALG_MATCH:
2121: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
2122: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.245 djm 2123: logdie("Unable to negotiate with %s: %s. "
2124: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 2125: ssh->kex->failed_choice);
1.212 djm 2126: }
2127: /* FALLTHROUGH */
1.205 djm 2128: default:
1.245 djm 2129: logdie("%s%sConnection %s %s: %s",
1.205 djm 2130: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 2131: ssh->state->server_side ? "from" : "to",
1.245 djm 2132: remote_id, ssh_err(r));
1.205 djm 2133: }
1.1 deraadt 2134: }
2135:
1.16 markus 2136: /*
2137: * Logs the error plus constructs and sends a disconnect packet, closes the
2138: * connection, and exits. This function never returns. The error message
2139: * should not contain a newline. The length of the formatted message must
2140: * not exceed 1024 bytes.
2141: */
1.2 provos 2142: void
1.201 markus 2143: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 2144: {
1.245 djm 2145: char buf[1024], remote_id[512];
1.14 markus 2146: va_list args;
2147: static int disconnecting = 0;
1.201 markus 2148: int r;
1.97 deraadt 2149:
1.14 markus 2150: if (disconnecting) /* Guard against recursive invocations. */
2151: fatal("packet_disconnect called recursively.");
2152: disconnecting = 1;
2153:
1.16 markus 2154: /*
2155: * Format the message. Note that the caller must make sure the
2156: * message is of limited size.
2157: */
1.245 djm 2158: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 2159: va_start(args, fmt);
2160: vsnprintf(buf, sizeof(buf), fmt, args);
2161: va_end(args);
2162:
1.99 markus 2163: /* Display the error locally */
1.245 djm 2164: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 2165:
1.205 djm 2166: /*
2167: * Send the disconnect message to the other side, and wait
2168: * for it to get sent.
2169: */
2170: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
2171: sshpkt_fatal(ssh, __func__, r);
2172:
2173: if ((r = ssh_packet_write_wait(ssh)) != 0)
2174: sshpkt_fatal(ssh, __func__, r);
1.14 markus 2175:
2176: /* Close the connection. */
1.201 markus 2177: ssh_packet_close(ssh);
1.112 markus 2178: cleanup_exit(255);
1.1 deraadt 2179: }
2180:
1.205 djm 2181: /*
2182: * Checks if there is any buffered output, and tries to write some of
2183: * the output.
2184: */
2185: int
1.201 markus 2186: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 2187: {
1.201 markus 2188: struct session_state *state = ssh->state;
2189: int len = sshbuf_len(state->output);
1.222 markus 2190: int r;
1.97 deraadt 2191:
1.14 markus 2192: if (len > 0) {
1.222 markus 2193: len = write(state->connection_out,
2194: sshbuf_ptr(state->output), len);
1.156 djm 2195: if (len == -1) {
2196: if (errno == EINTR || errno == EAGAIN)
1.205 djm 2197: return 0;
2198: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 2199: }
1.222 markus 2200: if (len == 0)
1.205 djm 2201: return SSH_ERR_CONN_CLOSED;
1.201 markus 2202: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 2203: return r;
1.14 markus 2204: }
1.205 djm 2205: return 0;
1.1 deraadt 2206: }
2207:
1.16 markus 2208: /*
2209: * Calls packet_write_poll repeatedly until all pending output data has been
2210: * written.
2211: */
1.205 djm 2212: int
1.201 markus 2213: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 2214: {
1.56 millert 2215: fd_set *setp;
1.205 djm 2216: int ret, r, ms_remain = 0;
1.154 dtucker 2217: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 2218: struct session_state *state = ssh->state;
1.56 millert 2219:
1.214 deraadt 2220: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 2221: NFDBITS), sizeof(fd_mask));
1.201 markus 2222: if (setp == NULL)
1.205 djm 2223: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 2224: if ((r = ssh_packet_write_poll(ssh)) != 0) {
2225: free(setp);
1.215 djm 2226: return r;
1.216 gsoares 2227: }
1.201 markus 2228: while (ssh_packet_have_data_to_write(ssh)) {
2229: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 2230: NFDBITS) * sizeof(fd_mask));
1.201 markus 2231: FD_SET(state->connection_out, setp);
1.154 dtucker 2232:
1.201 markus 2233: if (state->packet_timeout_ms > 0) {
2234: ms_remain = state->packet_timeout_ms;
1.154 dtucker 2235: timeoutp = &timeout;
2236: }
2237: for (;;) {
1.201 markus 2238: if (state->packet_timeout_ms != -1) {
1.154 dtucker 2239: ms_to_timeval(&timeout, ms_remain);
2240: gettimeofday(&start, NULL);
2241: }
1.201 markus 2242: if ((ret = select(state->connection_out + 1,
1.161 andreas 2243: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 2244: break;
1.161 andreas 2245: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 2246: break;
1.201 markus 2247: if (state->packet_timeout_ms == -1)
1.154 dtucker 2248: continue;
2249: ms_subtract_diff(&start, &ms_remain);
2250: if (ms_remain <= 0) {
2251: ret = 0;
2252: break;
2253: }
2254: }
2255: if (ret == 0) {
1.205 djm 2256: free(setp);
2257: return SSH_ERR_CONN_TIMEOUT;
2258: }
2259: if ((r = ssh_packet_write_poll(ssh)) != 0) {
2260: free(setp);
2261: return r;
1.154 dtucker 2262: }
1.14 markus 2263: }
1.186 djm 2264: free(setp);
1.205 djm 2265: return 0;
1.1 deraadt 2266: }
2267:
2268: /* Returns true if there is buffered data to write to the connection. */
2269:
1.2 provos 2270: int
1.201 markus 2271: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 2272: {
1.201 markus 2273: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 2274: }
2275:
2276: /* Returns true if there is not too much data to write to the connection. */
2277:
1.2 provos 2278: int
1.201 markus 2279: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 2280: {
1.201 markus 2281: if (ssh->state->interactive_mode)
2282: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 2283: else
1.201 markus 2284: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 2285: }
2286:
1.201 markus 2287: void
2288: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 2289: {
1.201 markus 2290: if (!ssh_packet_connection_is_on_socket(ssh))
1.101 markus 2291: return;
1.201 markus 2292: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 2293: case AF_INET:
2294: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 2295: if (setsockopt(ssh->state->connection_in,
1.173 djm 2296: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
2297: error("setsockopt IP_TOS %d: %.100s:",
2298: tos, strerror(errno));
2299: break;
2300: case AF_INET6:
2301: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 2302: if (setsockopt(ssh->state->connection_in,
1.173 djm 2303: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2304: error("setsockopt IPV6_TCLASS %d: %.100s:",
2305: tos, strerror(errno));
2306: break;
2307: }
1.101 markus 2308: }
2309:
1.1 deraadt 2310: /* Informs that the current session is interactive. Sets IP flags for that. */
2311:
1.2 provos 2312: void
1.201 markus 2313: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2314: {
1.201 markus 2315: struct session_state *state = ssh->state;
2316:
2317: if (state->set_interactive_called)
1.43 markus 2318: return;
1.201 markus 2319: state->set_interactive_called = 1;
1.1 deraadt 2320:
1.14 markus 2321: /* Record that we are in interactive mode. */
1.201 markus 2322: state->interactive_mode = interactive;
1.1 deraadt 2323:
1.19 markus 2324: /* Only set socket options if using a socket. */
1.201 markus 2325: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2326: return;
1.201 markus 2327: set_nodelay(state->connection_in);
2328: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2329: qos_bulk);
1.1 deraadt 2330: }
2331:
2332: /* Returns true if the current connection is interactive. */
2333:
1.2 provos 2334: int
1.201 markus 2335: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2336: {
1.201 markus 2337: return ssh->state->interactive_mode;
1.12 markus 2338: }
2339:
1.113 deraadt 2340: int
1.201 markus 2341: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2342: {
1.201 markus 2343: struct session_state *state = ssh->state;
2344:
2345: if (state->set_maxsize_called) {
1.106 itojun 2346: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2347: state->max_packet_size, s);
1.14 markus 2348: return -1;
2349: }
2350: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2351: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2352: return -1;
2353: }
1.201 markus 2354: state->set_maxsize_called = 1;
1.66 markus 2355: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2356: state->max_packet_size = s;
1.14 markus 2357: return s;
1.53 markus 2358: }
2359:
1.161 andreas 2360: int
1.201 markus 2361: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2362: {
1.201 markus 2363: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2364: }
2365:
2366: void
1.201 markus 2367: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2368: {
1.201 markus 2369: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2370: }
2371:
2372: u_int
1.201 markus 2373: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2374: {
1.201 markus 2375: return ssh->state->max_packet_size;
1.71 markus 2376: }
2377:
1.53 markus 2378: /*
2379: * 9.2. Ignored Data Message
1.61 markus 2380: *
1.53 markus 2381: * byte SSH_MSG_IGNORE
2382: * string data
1.61 markus 2383: *
1.53 markus 2384: * All implementations MUST understand (and ignore) this message at any
2385: * time (after receiving the protocol version). No implementation is
2386: * required to send them. This message can be used as an additional
2387: * protection measure against advanced traffic analysis techniques.
2388: */
1.54 markus 2389: void
1.201 markus 2390: ssh_packet_send_ignore(struct ssh *ssh, int nbytes)
1.54 markus 2391: {
1.115 avsm 2392: u_int32_t rnd = 0;
1.201 markus 2393: int r, i;
1.54 markus 2394:
1.201 markus 2395: if ((r = sshpkt_start(ssh, compat20 ?
2396: SSH2_MSG_IGNORE : SSH_MSG_IGNORE)) != 0 ||
2397: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2398: fatal("%s: %s", __func__, ssh_err(r));
1.75 deraadt 2399: for (i = 0; i < nbytes; i++) {
1.53 markus 2400: if (i % 4 == 0)
1.115 avsm 2401: rnd = arc4random();
1.201 markus 2402: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2403: fatal("%s: %s", __func__, ssh_err(r));
1.115 avsm 2404: rnd >>= 8;
1.53 markus 2405: }
1.105 markus 2406: }
2407:
2408: void
1.244 dtucker 2409: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2410: {
1.244 dtucker 2411: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2412: (unsigned int)seconds);
1.201 markus 2413: ssh->state->rekey_limit = bytes;
2414: ssh->state->rekey_interval = seconds;
1.184 dtucker 2415: }
2416:
2417: time_t
1.201 markus 2418: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2419: {
2420: time_t seconds;
2421:
1.201 markus 2422: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2423: monotime();
1.185 dtucker 2424: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2425: }
2426:
2427: void
1.201 markus 2428: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2429: {
1.201 markus 2430: ssh->state->server_side = 1;
1.118 markus 2431: }
2432:
2433: void
1.201 markus 2434: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2435: {
1.201 markus 2436: ssh->state->after_authentication = 1;
1.161 andreas 2437: }
2438:
2439: void *
1.201 markus 2440: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2441: {
1.201 markus 2442: return (void *)ssh->state->input;
1.161 andreas 2443: }
2444:
2445: void *
1.201 markus 2446: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2447: {
1.201 markus 2448: return (void *)ssh->state->output;
1.166 andreas 2449: }
2450:
1.196 markus 2451: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2452: static int
2453: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2454: {
1.239 djm 2455: int r;
1.196 markus 2456:
2457: debug("%s: called", __func__);
2458: /* This was set in net child, but is not visible in user child */
1.201 markus 2459: ssh->state->after_authentication = 1;
2460: ssh->state->rekeying = 0;
1.239 djm 2461: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2462: return r;
1.201 markus 2463: return 0;
2464: }
2465:
2466: /* Packet state (de-)serialization for privsep */
2467:
2468: /* turn kex into a blob for packet state serialization */
2469: static int
2470: kex_to_blob(struct sshbuf *m, struct kex *kex)
2471: {
2472: int r;
2473:
2474: if ((r = sshbuf_put_string(m, kex->session_id,
2475: kex->session_id_len)) != 0 ||
2476: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2477: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2478: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2479: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2480: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2481: (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2482: (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2483: (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2484: return r;
2485: return 0;
2486: }
2487:
2488: /* turn key exchange results into a blob for packet state serialization */
2489: static int
2490: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2491: {
2492: struct sshbuf *b;
2493: struct sshcipher_ctx *cc;
2494: struct sshcomp *comp;
2495: struct sshenc *enc;
2496: struct sshmac *mac;
2497: struct newkeys *newkey;
2498: int r;
2499:
2500: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2501: return SSH_ERR_INTERNAL_ERROR;
2502: enc = &newkey->enc;
2503: mac = &newkey->mac;
2504: comp = &newkey->comp;
1.235 djm 2505: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2506: ssh->state->receive_context;
1.201 markus 2507: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2508: return r;
2509: if ((b = sshbuf_new()) == NULL)
2510: return SSH_ERR_ALLOC_FAIL;
2511: /* The cipher struct is constant and shared, you export pointer */
2512: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2513: (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2514: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2515: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2516: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2517: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2518: goto out;
2519: if (cipher_authlen(enc->cipher) == 0) {
2520: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2521: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2522: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2523: goto out;
2524: }
2525: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2526: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2527: goto out;
2528: r = sshbuf_put_stringb(m, b);
2529: out:
1.221 mmcc 2530: sshbuf_free(b);
1.201 markus 2531: return r;
2532: }
2533:
2534: /* serialize packet state into a blob */
2535: int
2536: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2537: {
2538: struct session_state *state = ssh->state;
2539: u_char *p;
2540: size_t slen, rlen;
2541: int r, ssh1cipher;
2542:
2543: if (!compat20) {
1.235 djm 2544: ssh1cipher = cipher_ctx_get_number(state->receive_context);
2545: slen = cipher_get_keyiv_len(state->send_context);
2546: rlen = cipher_get_keyiv_len(state->receive_context);
1.201 markus 2547: if ((r = sshbuf_put_u32(m, state->remote_protocol_flags)) != 0 ||
2548: (r = sshbuf_put_u32(m, ssh1cipher)) != 0 ||
2549: (r = sshbuf_put_string(m, state->ssh1_key, state->ssh1_keylen)) != 0 ||
2550: (r = sshbuf_put_u32(m, slen)) != 0 ||
2551: (r = sshbuf_reserve(m, slen, &p)) != 0 ||
1.235 djm 2552: (r = cipher_get_keyiv(state->send_context, p, slen)) != 0 ||
1.201 markus 2553: (r = sshbuf_put_u32(m, rlen)) != 0 ||
2554: (r = sshbuf_reserve(m, rlen, &p)) != 0 ||
1.235 djm 2555: (r = cipher_get_keyiv(state->receive_context, p, rlen)) != 0)
1.201 markus 2556: return r;
2557: } else {
2558: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2559: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2560: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
1.224 dtucker 2561: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
1.208 markus 2562: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
1.201 markus 2563: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2564: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2565: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2566: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2567: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2568: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2569: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
2570: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0)
2571: return r;
2572: }
2573:
1.235 djm 2574: slen = cipher_get_keycontext(state->send_context, NULL);
2575: rlen = cipher_get_keycontext(state->receive_context, NULL);
1.201 markus 2576: if ((r = sshbuf_put_u32(m, slen)) != 0 ||
2577: (r = sshbuf_reserve(m, slen, &p)) != 0)
2578: return r;
1.235 djm 2579: if (cipher_get_keycontext(state->send_context, p) != (int)slen)
1.201 markus 2580: return SSH_ERR_INTERNAL_ERROR;
2581: if ((r = sshbuf_put_u32(m, rlen)) != 0 ||
2582: (r = sshbuf_reserve(m, rlen, &p)) != 0)
2583: return r;
1.235 djm 2584: if (cipher_get_keycontext(state->receive_context, p) != (int)rlen)
1.201 markus 2585: return SSH_ERR_INTERNAL_ERROR;
1.239 djm 2586: if ((r = sshbuf_put_stringb(m, state->input)) != 0 ||
1.201 markus 2587: (r = sshbuf_put_stringb(m, state->output)) != 0)
2588: return r;
2589:
2590: return 0;
2591: }
2592:
2593: /* restore key exchange results from blob for packet state de-serialization */
2594: static int
2595: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2596: {
2597: struct sshbuf *b = NULL;
2598: struct sshcomp *comp;
2599: struct sshenc *enc;
2600: struct sshmac *mac;
2601: struct newkeys *newkey = NULL;
2602: size_t keylen, ivlen, maclen;
2603: int r;
2604:
2605: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2606: r = SSH_ERR_ALLOC_FAIL;
2607: goto out;
2608: }
2609: if ((r = sshbuf_froms(m, &b)) != 0)
2610: goto out;
2611: #ifdef DEBUG_PK
2612: sshbuf_dump(b, stderr);
2613: #endif
2614: enc = &newkey->enc;
2615: mac = &newkey->mac;
2616: comp = &newkey->comp;
2617:
2618: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2619: (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2620: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2621: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2622: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2623: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2624: goto out;
2625: if (cipher_authlen(enc->cipher) == 0) {
2626: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2627: goto out;
2628: if ((r = mac_setup(mac, mac->name)) != 0)
2629: goto out;
2630: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2631: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2632: goto out;
2633: if (maclen > mac->key_len) {
2634: r = SSH_ERR_INVALID_FORMAT;
2635: goto out;
2636: }
2637: mac->key_len = maclen;
2638: }
2639: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2640: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2641: goto out;
2642: if (enc->name == NULL ||
2643: cipher_by_name(enc->name) != enc->cipher) {
2644: r = SSH_ERR_INVALID_FORMAT;
2645: goto out;
2646: }
2647: if (sshbuf_len(b) != 0) {
2648: r = SSH_ERR_INVALID_FORMAT;
2649: goto out;
2650: }
2651: enc->key_len = keylen;
2652: enc->iv_len = ivlen;
2653: ssh->kex->newkeys[mode] = newkey;
2654: newkey = NULL;
2655: r = 0;
2656: out:
1.219 mmcc 2657: free(newkey);
1.221 mmcc 2658: sshbuf_free(b);
1.201 markus 2659: return r;
2660: }
2661:
2662: /* restore kex from blob for packet state de-serialization */
2663: static int
2664: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2665: {
2666: struct kex *kex;
2667: int r;
2668:
2669: if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2670: (kex->my = sshbuf_new()) == NULL ||
2671: (kex->peer = sshbuf_new()) == NULL) {
2672: r = SSH_ERR_ALLOC_FAIL;
2673: goto out;
2674: }
2675: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2676: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2677: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2678: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2679: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2680: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2681: (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2682: (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2683: (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2684: goto out;
2685: kex->server = 1;
2686: kex->done = 1;
2687: r = 0;
2688: out:
2689: if (r != 0 || kexp == NULL) {
2690: if (kex != NULL) {
1.221 mmcc 2691: sshbuf_free(kex->my);
2692: sshbuf_free(kex->peer);
1.201 markus 2693: free(kex);
2694: }
2695: if (kexp != NULL)
2696: *kexp = NULL;
2697: } else {
2698: *kexp = kex;
2699: }
2700: return r;
2701: }
2702:
2703: /*
2704: * Restore packet state from content of blob 'm' (de-serialization).
2705: * Note that 'm' will be partially consumed on parsing or any other errors.
2706: */
2707: int
2708: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2709: {
2710: struct session_state *state = ssh->state;
2711: const u_char *ssh1key, *ivin, *ivout, *keyin, *keyout, *input, *output;
2712: size_t ssh1keylen, rlen, slen, ilen, olen;
2713: int r;
2714: u_int ssh1cipher = 0;
2715:
2716: if (!compat20) {
2717: if ((r = sshbuf_get_u32(m, &state->remote_protocol_flags)) != 0 ||
2718: (r = sshbuf_get_u32(m, &ssh1cipher)) != 0 ||
2719: (r = sshbuf_get_string_direct(m, &ssh1key, &ssh1keylen)) != 0 ||
2720: (r = sshbuf_get_string_direct(m, &ivout, &slen)) != 0 ||
2721: (r = sshbuf_get_string_direct(m, &ivin, &rlen)) != 0)
2722: return r;
2723: if (ssh1cipher > INT_MAX)
2724: return SSH_ERR_KEY_UNKNOWN_CIPHER;
2725: ssh_packet_set_encryption_key(ssh, ssh1key, ssh1keylen,
2726: (int)ssh1cipher);
1.235 djm 2727: if (cipher_get_keyiv_len(state->send_context) != (int)slen ||
2728: cipher_get_keyiv_len(state->receive_context) != (int)rlen)
1.201 markus 2729: return SSH_ERR_INVALID_FORMAT;
1.235 djm 2730: if ((r = cipher_set_keyiv(state->send_context, ivout)) != 0 ||
2731: (r = cipher_set_keyiv(state->receive_context, ivin)) != 0)
1.201 markus 2732: return r;
2733: } else {
2734: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2735: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2736: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
1.224 dtucker 2737: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
1.208 markus 2738: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
1.201 markus 2739: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2740: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2741: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2742: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2743: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2744: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2745: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2746: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2747: return r;
1.208 markus 2748: /*
2749: * We set the time here so that in post-auth privsep slave we
2750: * count from the completion of the authentication.
2751: */
2752: state->rekey_time = monotime();
1.201 markus 2753: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2754: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2755: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2756: return r;
2757: }
2758: if ((r = sshbuf_get_string_direct(m, &keyout, &slen)) != 0 ||
2759: (r = sshbuf_get_string_direct(m, &keyin, &rlen)) != 0)
2760: return r;
1.235 djm 2761: if (cipher_get_keycontext(state->send_context, NULL) != (int)slen ||
2762: cipher_get_keycontext(state->receive_context, NULL) != (int)rlen)
1.201 markus 2763: return SSH_ERR_INVALID_FORMAT;
1.235 djm 2764: cipher_set_keycontext(state->send_context, keyout);
2765: cipher_set_keycontext(state->receive_context, keyin);
1.201 markus 2766:
1.239 djm 2767: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2768: return r;
2769:
2770: sshbuf_reset(state->input);
2771: sshbuf_reset(state->output);
2772: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2773: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2774: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2775: (r = sshbuf_put(state->output, output, olen)) != 0)
2776: return r;
2777:
2778: if (sshbuf_len(m))
2779: return SSH_ERR_INVALID_FORMAT;
2780: debug3("%s: done", __func__);
2781: return 0;
2782: }
2783:
2784: /* NEW API */
2785:
2786: /* put data to the outgoing packet */
2787:
2788: int
2789: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2790: {
2791: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2792: }
2793:
2794: int
2795: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2796: {
2797: return sshbuf_putb(ssh->state->outgoing_packet, b);
2798: }
2799:
2800: int
2801: sshpkt_put_u8(struct ssh *ssh, u_char val)
2802: {
2803: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2804: }
2805:
2806: int
2807: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2808: {
2809: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2810: }
2811:
2812: int
2813: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2814: {
2815: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2816: }
2817:
2818: int
2819: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2820: {
2821: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2822: }
2823:
2824: int
2825: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2826: {
2827: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2828: }
2829:
2830: int
2831: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2832: {
2833: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2834: }
2835:
1.211 djm 2836: #ifdef WITH_OPENSSL
1.201 markus 2837: int
2838: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2839: {
2840: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2841: }
2842:
1.211 djm 2843: #ifdef WITH_SSH1
1.201 markus 2844: int
2845: sshpkt_put_bignum1(struct ssh *ssh, const BIGNUM *v)
2846: {
2847: return sshbuf_put_bignum1(ssh->state->outgoing_packet, v);
2848: }
1.211 djm 2849: #endif /* WITH_SSH1 */
1.201 markus 2850:
2851: int
2852: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2853: {
2854: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2855: }
1.211 djm 2856: #endif /* WITH_OPENSSL */
1.201 markus 2857:
2858: /* fetch data from the incoming packet */
2859:
2860: int
2861: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2862: {
2863: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2864: }
2865:
2866: int
2867: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2868: {
2869: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2870: }
2871:
2872: int
2873: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2874: {
2875: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2876: }
2877:
2878: int
2879: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2880: {
2881: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2882: }
2883:
2884: int
2885: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2886: {
2887: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2888: }
2889:
2890: int
2891: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2892: {
2893: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2894: }
2895:
2896: int
2897: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2898: {
2899: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2900: }
2901:
1.211 djm 2902: #ifdef WITH_OPENSSL
1.201 markus 2903: int
2904: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2905: {
2906: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2907: }
2908:
1.211 djm 2909: #ifdef WITH_SSH1
1.201 markus 2910: int
2911: sshpkt_get_bignum1(struct ssh *ssh, BIGNUM *v)
2912: {
2913: return sshbuf_get_bignum1(ssh->state->incoming_packet, v);
2914: }
1.211 djm 2915: #endif /* WITH_SSH1 */
1.201 markus 2916:
2917: int
2918: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2919: {
2920: return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2921: }
1.211 djm 2922: #endif /* WITH_OPENSSL */
1.201 markus 2923:
2924: int
2925: sshpkt_get_end(struct ssh *ssh)
2926: {
2927: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2928: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2929: return 0;
2930: }
2931:
2932: const u_char *
2933: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2934: {
2935: if (lenp != NULL)
2936: *lenp = sshbuf_len(ssh->state->incoming_packet);
2937: return sshbuf_ptr(ssh->state->incoming_packet);
2938: }
2939:
2940: /* start a new packet */
2941:
2942: int
2943: sshpkt_start(struct ssh *ssh, u_char type)
2944: {
2945: u_char buf[9];
2946: int len;
2947:
2948: DBG(debug("packet_start[%d]", type));
2949: len = compat20 ? 6 : 9;
2950: memset(buf, 0, len - 1);
2951: buf[len - 1] = type;
2952: sshbuf_reset(ssh->state->outgoing_packet);
2953: return sshbuf_put(ssh->state->outgoing_packet, buf, len);
2954: }
2955:
1.242 markus 2956: static int
2957: ssh_packet_send_mux(struct ssh *ssh)
2958: {
2959: struct session_state *state = ssh->state;
2960: u_char type, *cp;
2961: size_t len;
2962: int r;
2963:
2964: if (ssh->kex)
2965: return SSH_ERR_INTERNAL_ERROR;
2966: len = sshbuf_len(state->outgoing_packet);
2967: if (len < 6)
2968: return SSH_ERR_INTERNAL_ERROR;
2969: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2970: type = cp[5];
2971: if (ssh_packet_log_type(type))
2972: debug3("%s: type %u", __func__, type);
2973: /* drop everything, but the connection protocol */
2974: if (type >= SSH2_MSG_CONNECTION_MIN &&
2975: type <= SSH2_MSG_CONNECTION_MAX) {
2976: POKE_U32(cp, len - 4);
2977: if ((r = sshbuf_putb(state->output,
2978: state->outgoing_packet)) != 0)
2979: return r;
2980: /* sshbuf_dump(state->output, stderr); */
2981: }
2982: sshbuf_reset(state->outgoing_packet);
2983: return 0;
2984: }
2985:
1.201 markus 2986: /* send it */
2987:
2988: int
2989: sshpkt_send(struct ssh *ssh)
2990: {
1.242 markus 2991: if (ssh->state && ssh->state->mux)
2992: return ssh_packet_send_mux(ssh);
1.201 markus 2993: if (compat20)
2994: return ssh_packet_send2(ssh);
2995: else
2996: return ssh_packet_send1(ssh);
2997: }
2998:
2999: int
3000: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
3001: {
3002: char buf[1024];
3003: va_list args;
3004: int r;
3005:
3006: va_start(args, fmt);
3007: vsnprintf(buf, sizeof(buf), fmt, args);
3008: va_end(args);
3009:
3010: if (compat20) {
3011: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
3012: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
3013: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
3014: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
3015: (r = sshpkt_send(ssh)) != 0)
3016: return r;
3017: } else {
3018: if ((r = sshpkt_start(ssh, SSH_MSG_DISCONNECT)) != 0 ||
3019: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
3020: (r = sshpkt_send(ssh)) != 0)
3021: return r;
1.166 andreas 3022: }
1.201 markus 3023: return 0;
3024: }
3025:
3026: /* roundup current message to pad bytes */
3027: int
3028: sshpkt_add_padding(struct ssh *ssh, u_char pad)
3029: {
3030: ssh->state->extra_pad = pad;
3031: return 0;
1.1 deraadt 3032: }
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