Annotation of src/usr.bin/ssh/packet.c, Revision 1.248
1.248 ! djm 1: /* $OpenBSD: packet.c,v 1.247 2017/03/11 13:07:35 markus Exp $ */
1.1 deraadt 2: /*
1.15 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.35 deraadt 6: * This file contains code implementing the packet protocol and communication
7: * with the other side. This same code is used both on client and server side.
1.29 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
1.29 markus 14: *
1.25 markus 15: *
16: * SSH2 packet format added by Markus Friedl.
1.69 markus 17: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.25 markus 18: *
1.35 deraadt 19: * Redistribution and use in source and binary forms, with or without
20: * modification, are permitted provided that the following conditions
21: * are met:
22: * 1. Redistributions of source code must retain the above copyright
23: * notice, this list of conditions and the following disclaimer.
24: * 2. Redistributions in binary form must reproduce the above copyright
25: * notice, this list of conditions and the following disclaimer in the
26: * documentation and/or other materials provided with the distribution.
27: *
28: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15 deraadt 38: */
1.1 deraadt 39:
1.142 deraadt 40: #include <sys/types.h>
1.105 markus 41: #include <sys/queue.h>
1.132 stevesk 42: #include <sys/socket.h>
1.138 stevesk 43: #include <sys/time.h>
1.132 stevesk 44: #include <netinet/in.h>
1.121 stevesk 45: #include <netinet/ip.h>
1.134 stevesk 46:
1.135 stevesk 47: #include <errno.h>
1.230 djm 48: #include <netdb.h>
1.134 stevesk 49: #include <stdarg.h>
1.141 stevesk 50: #include <stdio.h>
1.140 stevesk 51: #include <stdlib.h>
1.137 stevesk 52: #include <string.h>
1.136 stevesk 53: #include <unistd.h>
1.203 deraadt 54: #include <limits.h>
1.142 deraadt 55: #include <signal.h>
1.184 dtucker 56: #include <time.h>
1.1 deraadt 57:
1.201 markus 58: #include <zlib.h>
59:
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: fatal("no SSH protocol 1 support");
1.170 djm 804: }
805:
1.16 markus 806: /*
807: * Finalizes and sends the packet. If the encryption key has been set,
808: * encrypts the packet before sending.
809: */
1.14 markus 810:
1.201 markus 811: int
812: ssh_packet_send1(struct ssh *ssh)
1.1 deraadt 813: {
1.201 markus 814: struct session_state *state = ssh->state;
1.89 markus 815: u_char buf[8], *cp;
1.201 markus 816: int r, padding, len;
1.40 markus 817: u_int checksum;
1.14 markus 818:
1.16 markus 819: /*
820: * If using packet compression, compress the payload of the outgoing
821: * packet.
822: */
1.201 markus 823: if (state->packet_compression) {
824: sshbuf_reset(state->compression_buffer);
1.14 markus 825: /* Skip padding. */
1.201 markus 826: if ((r = sshbuf_consume(state->outgoing_packet, 8)) != 0)
827: goto out;
1.14 markus 828: /* padding */
1.201 markus 829: if ((r = sshbuf_put(state->compression_buffer,
830: "\0\0\0\0\0\0\0\0", 8)) != 0)
831: goto out;
832: if ((r = compress_buffer(ssh, state->outgoing_packet,
833: state->compression_buffer)) != 0)
834: goto out;
835: sshbuf_reset(state->outgoing_packet);
836: if ((r = sshbuf_putb(state->outgoing_packet,
837: state->compression_buffer)) != 0)
838: goto out;
1.14 markus 839: }
840: /* Compute packet length without padding (add checksum, remove padding). */
1.201 markus 841: len = sshbuf_len(state->outgoing_packet) + 4 - 8;
1.14 markus 842:
1.32 markus 843: /* Insert padding. Initialized to zero in packet_start1() */
1.14 markus 844: padding = 8 - len % 8;
1.235 djm 845: if (!cipher_ctx_is_plaintext(state->send_context)) {
1.201 markus 846: cp = sshbuf_mutable_ptr(state->outgoing_packet);
847: if (cp == NULL) {
848: r = SSH_ERR_INTERNAL_ERROR;
849: goto out;
1.14 markus 850: }
1.201 markus 851: arc4random_buf(cp + 8 - padding, padding);
1.14 markus 852: }
1.201 markus 853: if ((r = sshbuf_consume(state->outgoing_packet, 8 - padding)) != 0)
854: goto out;
1.14 markus 855:
856: /* Add check bytes. */
1.201 markus 857: checksum = ssh_crc32(sshbuf_ptr(state->outgoing_packet),
858: sshbuf_len(state->outgoing_packet));
859: POKE_U32(buf, checksum);
860: if ((r = sshbuf_put(state->outgoing_packet, buf, 4)) != 0)
861: goto out;
1.1 deraadt 862:
863: #ifdef PACKET_DEBUG
1.14 markus 864: fprintf(stderr, "packet_send plain: ");
1.201 markus 865: sshbuf_dump(state->outgoing_packet, stderr);
1.1 deraadt 866: #endif
867:
1.14 markus 868: /* Append to output. */
1.201 markus 869: POKE_U32(buf, len);
870: if ((r = sshbuf_put(state->output, buf, 4)) != 0)
871: goto out;
872: if ((r = sshbuf_reserve(state->output,
873: sshbuf_len(state->outgoing_packet), &cp)) != 0)
874: goto out;
1.235 djm 875: if ((r = cipher_crypt(state->send_context, 0, cp,
1.201 markus 876: sshbuf_ptr(state->outgoing_packet),
877: sshbuf_len(state->outgoing_packet), 0, 0)) != 0)
878: goto out;
1.14 markus 879:
1.1 deraadt 880: #ifdef PACKET_DEBUG
1.14 markus 881: fprintf(stderr, "encrypted: ");
1.201 markus 882: sshbuf_dump(state->output, stderr);
1.1 deraadt 883: #endif
1.201 markus 884: state->p_send.packets++;
885: state->p_send.bytes += len +
886: sshbuf_len(state->outgoing_packet);
887: sshbuf_reset(state->outgoing_packet);
1.1 deraadt 888:
1.16 markus 889: /*
1.120 djm 890: * Note that the packet is now only buffered in output. It won't be
1.205 djm 891: * actually sent until ssh_packet_write_wait or ssh_packet_write_poll
892: * is called.
1.16 markus 893: */
1.201 markus 894: r = 0;
895: out:
896: return r;
1.1 deraadt 897: }
898:
1.201 markus 899: int
900: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 901: {
1.201 markus 902: struct session_state *state = ssh->state;
903: struct sshenc *enc;
904: struct sshmac *mac;
905: struct sshcomp *comp;
1.235 djm 906: struct sshcipher_ctx **ccp;
1.236 markus 907: struct packet_state *ps;
1.105 markus 908: u_int64_t *max_blocks;
1.236 markus 909: const char *wmsg, *dir;
1.197 djm 910: int r, crypt_type;
1.57 markus 911:
1.100 markus 912: debug2("set_newkeys: mode %d", mode);
1.57 markus 913:
1.88 markus 914: if (mode == MODE_OUT) {
1.236 markus 915: dir = "output";
1.235 djm 916: ccp = &state->send_context;
1.115 avsm 917: crypt_type = CIPHER_ENCRYPT;
1.236 markus 918: ps = &state->p_send;
1.201 markus 919: max_blocks = &state->max_blocks_out;
1.88 markus 920: } else {
1.236 markus 921: dir = "input";
1.235 djm 922: ccp = &state->receive_context;
1.115 avsm 923: crypt_type = CIPHER_DECRYPT;
1.236 markus 924: ps = &state->p_read;
1.201 markus 925: max_blocks = &state->max_blocks_in;
1.88 markus 926: }
1.201 markus 927: if (state->newkeys[mode] != NULL) {
1.236 markus 928: debug("%s: rekeying after %llu %s blocks"
929: " (%llu bytes total)", __func__,
930: (unsigned long long)ps->blocks, dir,
931: (unsigned long long)ps->bytes);
1.235 djm 932: cipher_free(*ccp);
933: *ccp = NULL;
1.201 markus 934: enc = &state->newkeys[mode]->enc;
935: mac = &state->newkeys[mode]->mac;
936: comp = &state->newkeys[mode]->comp;
1.148 pvalchev 937: mac_clear(mac);
1.192 djm 938: explicit_bzero(enc->iv, enc->iv_len);
939: explicit_bzero(enc->key, enc->key_len);
940: explicit_bzero(mac->key, mac->key_len);
1.186 djm 941: free(enc->name);
942: free(enc->iv);
943: free(enc->key);
944: free(mac->name);
945: free(mac->key);
946: free(comp->name);
1.201 markus 947: free(state->newkeys[mode]);
1.57 markus 948: }
1.236 markus 949: /* note that both bytes and the seqnr are not reset */
950: ps->packets = ps->blocks = 0;
1.201 markus 951: /* move newkeys from kex to state */
952: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
953: return SSH_ERR_INTERNAL_ERROR;
954: ssh->kex->newkeys[mode] = NULL;
955: enc = &state->newkeys[mode]->enc;
956: mac = &state->newkeys[mode]->mac;
957: comp = &state->newkeys[mode]->comp;
958: if (cipher_authlen(enc->cipher) == 0) {
959: if ((r = mac_init(mac)) != 0)
960: return r;
961: }
962: mac->enabled = 1;
1.57 markus 963: DBG(debug("cipher_init_context: %d", mode));
1.235 djm 964: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 965: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 966: return r;
967: if (!state->cipher_warning_done &&
1.235 djm 968: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 969: error("Warning: %s", wmsg);
970: state->cipher_warning_done = 1;
971: }
1.91 markus 972: /* Deleting the keys does not gain extra security */
1.192 djm 973: /* explicit_bzero(enc->iv, enc->block_size);
974: explicit_bzero(enc->key, enc->key_len);
975: explicit_bzero(mac->key, mac->key_len); */
1.241 djm 976: if ((comp->type == COMP_ZLIB ||
977: (comp->type == COMP_DELAYED &&
978: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 979: if ((r = ssh_packet_init_compression(ssh)) < 0)
980: return r;
981: if (mode == MODE_OUT) {
982: if ((r = start_compression_out(ssh, 6)) != 0)
983: return r;
984: } else {
985: if ((r = start_compression_in(ssh)) != 0)
986: return r;
987: }
1.57 markus 988: comp->enabled = 1;
989: }
1.109 markus 990: /*
991: * The 2^(blocksize*2) limit is too expensive for 3DES,
992: * blowfish, etc, so enforce a 1GB limit for small blocksizes.
993: */
994: if (enc->block_size >= 16)
995: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
996: else
997: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 998: if (state->rekey_limit)
1.237 deraadt 999: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 1000: state->rekey_limit / enc->block_size);
1.227 djm 1001: debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1.201 markus 1002: return 0;
1.57 markus 1003: }
1004:
1.228 djm 1005: #define MAX_PACKETS (1U<<31)
1006: static int
1007: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
1008: {
1009: struct session_state *state = ssh->state;
1010: u_int32_t out_blocks;
1011:
1012: /* XXX client can't cope with rekeying pre-auth */
1013: if (!state->after_authentication)
1014: return 0;
1015:
1016: /* Haven't keyed yet or KEX in progress. */
1017: if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
1018: return 0;
1019:
1020: /* Peer can't rekey */
1021: if (ssh->compat & SSH_BUG_NOREKEY)
1022: return 0;
1023:
1024: /*
1025: * Permit one packet in or out per rekey - this allows us to
1026: * make progress when rekey limits are very small.
1027: */
1028: if (state->p_send.packets == 0 && state->p_read.packets == 0)
1029: return 0;
1030:
1031: /* Time-based rekeying */
1032: if (state->rekey_interval != 0 &&
1.244 dtucker 1033: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 1034: return 1;
1035:
1036: /* Always rekey when MAX_PACKETS sent in either direction */
1037: if (state->p_send.packets > MAX_PACKETS ||
1038: state->p_read.packets > MAX_PACKETS)
1039: return 1;
1040:
1041: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 1042: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 1043: state->newkeys[MODE_OUT]->enc.block_size);
1044: return (state->max_blocks_out &&
1045: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
1046: (state->max_blocks_in &&
1047: (state->p_read.blocks > state->max_blocks_in));
1048: }
1049:
1.16 markus 1050: /*
1.118 markus 1051: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 1052: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 1053: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
1054: */
1.201 markus 1055: static int
1056: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 1057: {
1.201 markus 1058: struct session_state *state = ssh->state;
1059: struct sshcomp *comp = NULL;
1060: int r, mode;
1.118 markus 1061:
1062: /*
1063: * Remember that we are past the authentication step, so rekeying
1064: * with COMP_DELAYED will turn on compression immediately.
1065: */
1.201 markus 1066: state->after_authentication = 1;
1.118 markus 1067: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 1068: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 1069: if (state->newkeys[mode] == NULL)
1.145 markus 1070: continue;
1.201 markus 1071: comp = &state->newkeys[mode]->comp;
1.118 markus 1072: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 1073: if ((r = ssh_packet_init_compression(ssh)) != 0)
1074: return r;
1075: if (mode == MODE_OUT) {
1076: if ((r = start_compression_out(ssh, 6)) != 0)
1077: return r;
1078: } else {
1079: if ((r = start_compression_in(ssh)) != 0)
1080: return r;
1081: }
1.118 markus 1082: comp->enabled = 1;
1083: }
1084: }
1.201 markus 1085: return 0;
1.118 markus 1086: }
1087:
1.226 djm 1088: /* Used to mute debug logging for noisy packet types */
1.242 markus 1089: int
1.226 djm 1090: ssh_packet_log_type(u_char type)
1091: {
1092: switch (type) {
1093: case SSH2_MSG_CHANNEL_DATA:
1094: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1095: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1096: return 0;
1097: default:
1098: return 1;
1099: }
1100: }
1101:
1.118 markus 1102: /*
1.25 markus 1103: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1104: */
1.201 markus 1105: int
1106: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1107: {
1.201 markus 1108: struct session_state *state = ssh->state;
1.200 markus 1109: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1110: u_char tmp, padlen, pad = 0;
1.201 markus 1111: u_int authlen = 0, aadlen = 0;
1112: u_int len;
1113: struct sshenc *enc = NULL;
1114: struct sshmac *mac = NULL;
1115: struct sshcomp *comp = NULL;
1116: int r, block_size;
1117:
1118: if (state->newkeys[MODE_OUT] != NULL) {
1119: enc = &state->newkeys[MODE_OUT]->enc;
1120: mac = &state->newkeys[MODE_OUT]->mac;
1121: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1122: /* disable mac for authenticated encryption */
1123: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1124: mac = NULL;
1.25 markus 1125: }
1.88 markus 1126: block_size = enc ? enc->block_size : 8;
1.180 markus 1127: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1128:
1.201 markus 1129: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1130: if (ssh_packet_log_type(type))
1131: debug3("send packet: type %u", type);
1.25 markus 1132: #ifdef PACKET_DEBUG
1133: fprintf(stderr, "plain: ");
1.201 markus 1134: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1135: #endif
1136:
1137: if (comp && comp->enabled) {
1.201 markus 1138: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1139: /* skip header, compress only payload */
1.201 markus 1140: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1141: goto out;
1142: sshbuf_reset(state->compression_buffer);
1143: if ((r = compress_buffer(ssh, state->outgoing_packet,
1144: state->compression_buffer)) != 0)
1145: goto out;
1146: sshbuf_reset(state->outgoing_packet);
1147: if ((r = sshbuf_put(state->outgoing_packet,
1148: "\0\0\0\0\0", 5)) != 0 ||
1149: (r = sshbuf_putb(state->outgoing_packet,
1150: state->compression_buffer)) != 0)
1151: goto out;
1152: DBG(debug("compression: raw %d compressed %zd", len,
1153: sshbuf_len(state->outgoing_packet)));
1.25 markus 1154: }
1155:
1156: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1157: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1158:
1159: /*
1160: * calc size of padding, alloc space, get random data,
1161: * minimum padding is 4 bytes
1162: */
1.178 markus 1163: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1164: padlen = block_size - (len % block_size);
1165: if (padlen < 4)
1166: padlen += block_size;
1.201 markus 1167: if (state->extra_pad) {
1.233 djm 1168: tmp = state->extra_pad;
1.201 markus 1169: state->extra_pad =
1.237 deraadt 1170: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1171: /* check if roundup overflowed */
1172: if (state->extra_pad < tmp)
1173: return SSH_ERR_INVALID_ARGUMENT;
1174: tmp = (len + padlen) % state->extra_pad;
1175: /* Check whether pad calculation below will underflow */
1176: if (tmp > state->extra_pad)
1177: return SSH_ERR_INVALID_ARGUMENT;
1178: pad = state->extra_pad - tmp;
1.193 djm 1179: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1180: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1181: tmp = padlen;
1.71 markus 1182: padlen += pad;
1.233 djm 1183: /* Check whether padlen calculation overflowed */
1184: if (padlen < tmp)
1185: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1186: state->extra_pad = 0;
1.71 markus 1187: }
1.201 markus 1188: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1189: goto out;
1.235 djm 1190: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1191: /* random padding */
1.201 markus 1192: arc4random_buf(cp, padlen);
1.32 markus 1193: } else {
1194: /* clear padding */
1.192 djm 1195: explicit_bzero(cp, padlen);
1.25 markus 1196: }
1.178 markus 1197: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1198: len = sshbuf_len(state->outgoing_packet);
1199: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1200: if (cp == NULL) {
1201: r = SSH_ERR_INTERNAL_ERROR;
1202: goto out;
1203: }
1.25 markus 1204: /* packet_length includes payload, padding and padding length field */
1.201 markus 1205: POKE_U32(cp, len - 4);
1.89 markus 1206: cp[4] = padlen;
1.178 markus 1207: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1208: len, padlen, aadlen));
1.25 markus 1209:
1210: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1211: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1212: if ((r = mac_compute(mac, state->p_send.seqnr,
1213: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1214: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1215: goto out;
1216: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1217: }
1218: /* encrypt packet and append to output buffer. */
1.201 markus 1219: if ((r = sshbuf_reserve(state->output,
1220: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1221: goto out;
1.235 djm 1222: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1223: sshbuf_ptr(state->outgoing_packet),
1224: len - aadlen, aadlen, authlen)) != 0)
1225: goto out;
1.25 markus 1226: /* append unencrypted MAC */
1.178 markus 1227: if (mac && mac->enabled) {
1228: if (mac->etm) {
1229: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1230: if ((r = mac_compute(mac, state->p_send.seqnr,
1231: cp, len, macbuf, sizeof(macbuf))) != 0)
1232: goto out;
1.178 markus 1233: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1234: state->p_send.seqnr));
1.178 markus 1235: }
1.201 markus 1236: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1237: goto out;
1.178 markus 1238: }
1.25 markus 1239: #ifdef PACKET_DEBUG
1240: fprintf(stderr, "encrypted: ");
1.201 markus 1241: sshbuf_dump(state->output, stderr);
1.25 markus 1242: #endif
1.29 markus 1243: /* increment sequence number for outgoing packets */
1.201 markus 1244: if (++state->p_send.seqnr == 0)
1.106 itojun 1245: logit("outgoing seqnr wraps around");
1.201 markus 1246: if (++state->p_send.packets == 0)
1247: if (!(ssh->compat & SSH_BUG_NOREKEY))
1248: return SSH_ERR_NEED_REKEY;
1249: state->p_send.blocks += len / block_size;
1250: state->p_send.bytes += len;
1251: sshbuf_reset(state->outgoing_packet);
1.25 markus 1252:
1.57 markus 1253: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1254: r = ssh_set_newkeys(ssh, MODE_OUT);
1255: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1256: r = ssh_packet_enable_delayed_compress(ssh);
1257: else
1258: r = 0;
1259: out:
1260: return r;
1.25 markus 1261: }
1262:
1.228 djm 1263: /* returns non-zero if the specified packet type is usec by KEX */
1264: static int
1265: ssh_packet_type_is_kex(u_char type)
1266: {
1267: return
1268: type >= SSH2_MSG_TRANSPORT_MIN &&
1269: type <= SSH2_MSG_TRANSPORT_MAX &&
1270: type != SSH2_MSG_SERVICE_REQUEST &&
1271: type != SSH2_MSG_SERVICE_ACCEPT &&
1272: type != SSH2_MSG_EXT_INFO;
1273: }
1274:
1.201 markus 1275: int
1276: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1277: {
1.201 markus 1278: struct session_state *state = ssh->state;
1.105 markus 1279: struct packet *p;
1.201 markus 1280: u_char type;
1.228 djm 1281: int r, need_rekey;
1.105 markus 1282:
1.228 djm 1283: if (sshbuf_len(state->outgoing_packet) < 6)
1284: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1285: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1286: need_rekey = !ssh_packet_type_is_kex(type) &&
1287: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1288:
1.228 djm 1289: /*
1290: * During rekeying we can only send key exchange messages.
1291: * Queue everything else.
1292: */
1293: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1294: if (need_rekey)
1295: debug3("%s: rekex triggered", __func__);
1296: debug("enqueue packet: %u", type);
1297: p = calloc(1, sizeof(*p));
1298: if (p == NULL)
1299: return SSH_ERR_ALLOC_FAIL;
1300: p->type = type;
1301: p->payload = state->outgoing_packet;
1302: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1303: state->outgoing_packet = sshbuf_new();
1304: if (state->outgoing_packet == NULL)
1305: return SSH_ERR_ALLOC_FAIL;
1306: if (need_rekey) {
1307: /*
1308: * This packet triggered a rekey, so send the
1309: * KEXINIT now.
1310: * NB. reenters this function via kex_start_rekex().
1311: */
1312: return kex_start_rekex(ssh);
1.105 markus 1313: }
1.228 djm 1314: return 0;
1.105 markus 1315: }
1316:
1317: /* rekeying starts with sending KEXINIT */
1318: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1319: state->rekeying = 1;
1.105 markus 1320:
1.201 markus 1321: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1322: return r;
1.105 markus 1323:
1324: /* after a NEWKEYS message we can send the complete queue */
1325: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1326: state->rekeying = 0;
1327: state->rekey_time = monotime();
1328: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1329: type = p->type;
1.228 djm 1330: /*
1331: * If this packet triggers a rekex, then skip the
1332: * remaining packets in the queue for now.
1333: * NB. re-enters this function via kex_start_rekex.
1334: */
1335: if (ssh_packet_need_rekeying(ssh,
1336: sshbuf_len(p->payload))) {
1337: debug3("%s: queued packet triggered rekex",
1338: __func__);
1339: return kex_start_rekex(ssh);
1340: }
1.105 markus 1341: debug("dequeue packet: %u", type);
1.201 markus 1342: sshbuf_free(state->outgoing_packet);
1343: state->outgoing_packet = p->payload;
1344: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1345: memset(p, 0, sizeof(*p));
1.186 djm 1346: free(p);
1.201 markus 1347: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1348: return r;
1.105 markus 1349: }
1350: }
1.201 markus 1351: return 0;
1.25 markus 1352: }
1353:
1354: /*
1.16 markus 1355: * Waits until a packet has been received, and returns its type. Note that
1356: * no other data is processed until this returns, so this function should not
1357: * be used during the interactive session.
1358: */
1.1 deraadt 1359:
1.2 provos 1360: int
1.201 markus 1361: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1362: {
1.201 markus 1363: struct session_state *state = ssh->state;
1.222 markus 1364: int len, r, ms_remain;
1.56 millert 1365: fd_set *setp;
1.14 markus 1366: char buf[8192];
1.155 deraadt 1367: struct timeval timeout, start, *timeoutp = NULL;
1368:
1.25 markus 1369: DBG(debug("packet_read()"));
1.14 markus 1370:
1.214 deraadt 1371: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1372: NFDBITS), sizeof(fd_mask));
1.201 markus 1373: if (setp == NULL)
1374: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1375:
1.205 djm 1376: /*
1377: * Since we are blocking, ensure that all written packets have
1378: * been sent.
1379: */
1.210 markus 1380: if ((r = ssh_packet_write_wait(ssh)) != 0)
1381: goto out;
1.14 markus 1382:
1383: /* Stay in the loop until we have received a complete packet. */
1384: for (;;) {
1385: /* Try to read a packet from the buffer. */
1.201 markus 1386: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1387: if (r != 0)
1388: break;
1.62 markus 1389: if (!compat20 && (
1.201 markus 1390: *typep == SSH_SMSG_SUCCESS
1391: || *typep == SSH_SMSG_FAILURE
1392: || *typep == SSH_CMSG_EOF
1393: || *typep == SSH_CMSG_EXIT_CONFIRMATION))
1394: if ((r = sshpkt_get_end(ssh)) != 0)
1395: break;
1.14 markus 1396: /* If we got a packet, return it. */
1.201 markus 1397: if (*typep != SSH_MSG_NONE)
1398: break;
1.16 markus 1399: /*
1400: * Otherwise, wait for some data to arrive, add it to the
1401: * buffer, and try again.
1402: */
1.201 markus 1403: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1404: NFDBITS) * sizeof(fd_mask));
1.201 markus 1405: FD_SET(state->connection_in, setp);
1.16 markus 1406:
1.201 markus 1407: if (state->packet_timeout_ms > 0) {
1408: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1409: timeoutp = &timeout;
1410: }
1.14 markus 1411: /* Wait for some data to arrive. */
1.154 dtucker 1412: for (;;) {
1.201 markus 1413: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1414: ms_to_timeval(&timeout, ms_remain);
1415: gettimeofday(&start, NULL);
1416: }
1.201 markus 1417: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1418: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1419: break;
1.161 andreas 1420: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1421: break;
1.201 markus 1422: if (state->packet_timeout_ms == -1)
1.154 dtucker 1423: continue;
1424: ms_subtract_diff(&start, &ms_remain);
1425: if (ms_remain <= 0) {
1.201 markus 1426: r = 0;
1.154 dtucker 1427: break;
1428: }
1429: }
1.246 djm 1430: if (r == 0) {
1431: r = SSH_ERR_CONN_TIMEOUT;
1432: goto out;
1433: }
1.14 markus 1434: /* Read data from the socket. */
1.222 markus 1435: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1436: if (len == 0) {
1437: r = SSH_ERR_CONN_CLOSED;
1438: goto out;
1439: }
1440: if (len < 0) {
1441: r = SSH_ERR_SYSTEM_ERROR;
1442: goto out;
1443: }
1.204 djm 1444:
1.14 markus 1445: /* Append it to the buffer. */
1.204 djm 1446: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1447: goto out;
1.14 markus 1448: }
1.210 markus 1449: out:
1.201 markus 1450: free(setp);
1451: return r;
1.1 deraadt 1452: }
1453:
1.77 djm 1454: int
1.201 markus 1455: ssh_packet_read(struct ssh *ssh)
1.77 djm 1456: {
1.201 markus 1457: u_char type;
1458: int r;
1459:
1460: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1461: fatal("%s: %s", __func__, ssh_err(r));
1462: return type;
1.77 djm 1463: }
1464:
1.16 markus 1465: /*
1466: * Waits until a packet has been received, verifies that its type matches
1467: * that given, and gives a fatal error and exits if there is a mismatch.
1468: */
1.1 deraadt 1469:
1.205 djm 1470: int
1471: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1472: {
1.205 djm 1473: int r;
1474: u_char type;
1.1 deraadt 1475:
1.205 djm 1476: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1477: return r;
1478: if (type != expected_type) {
1479: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1480: "Protocol error: expected packet type %d, got %d",
1.205 djm 1481: expected_type, type)) != 0)
1482: return r;
1483: return SSH_ERR_PROTOCOL_ERROR;
1484: }
1485: return 0;
1.1 deraadt 1486: }
1487:
1488: /* Checks if a full packet is available in the data received so far via
1.14 markus 1489: * packet_process_incoming. If so, reads the packet; otherwise returns
1490: * SSH_MSG_NONE. This does not wait for data from the connection.
1491: *
1.150 dtucker 1492: * SSH_MSG_DISCONNECT is handled specially here. Also,
1493: * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1494: * to higher levels.
1.14 markus 1495: */
1.1 deraadt 1496:
1.201 markus 1497: int
1498: ssh_packet_read_poll1(struct ssh *ssh, u_char *typep)
1.1 deraadt 1499: {
1.201 markus 1500: struct session_state *state = ssh->state;
1.40 markus 1501: u_int len, padded_len;
1.205 djm 1502: const char *emsg;
1.201 markus 1503: const u_char *cp;
1504: u_char *p;
1.40 markus 1505: u_int checksum, stored_checksum;
1.201 markus 1506: int r;
1507:
1508: *typep = SSH_MSG_NONE;
1.14 markus 1509:
1510: /* Check if input size is less than minimum packet size. */
1.201 markus 1511: if (sshbuf_len(state->input) < 4 + 8)
1512: return 0;
1.14 markus 1513: /* Get length of incoming packet. */
1.201 markus 1514: len = PEEK_U32(sshbuf_ptr(state->input));
1.205 djm 1515: if (len < 1 + 2 + 2 || len > 256 * 1024) {
1516: if ((r = sshpkt_disconnect(ssh, "Bad packet length %u",
1517: len)) != 0)
1518: return r;
1519: return SSH_ERR_CONN_CORRUPT;
1520: }
1.14 markus 1521: padded_len = (len + 8) & ~7;
1522:
1523: /* Check if the packet has been entirely received. */
1.201 markus 1524: if (sshbuf_len(state->input) < 4 + padded_len)
1525: return 0;
1.14 markus 1526:
1527: /* The entire packet is in buffer. */
1528:
1529: /* Consume packet length. */
1.201 markus 1530: if ((r = sshbuf_consume(state->input, 4)) != 0)
1531: goto out;
1.14 markus 1532:
1.62 markus 1533: /*
1534: * Cryptographic attack detector for ssh
1535: * (C)1998 CORE-SDI, Buenos Aires Argentina
1536: * Ariel Futoransky(futo@core-sdi.com)
1537: */
1.235 djm 1538: if (!cipher_ctx_is_plaintext(state->receive_context)) {
1.205 djm 1539: emsg = NULL;
1.201 markus 1540: switch (detect_attack(&state->deattack,
1541: sshbuf_ptr(state->input), padded_len)) {
1542: case DEATTACK_OK:
1543: break;
1.144 djm 1544: case DEATTACK_DETECTED:
1.205 djm 1545: emsg = "crc32 compensation attack detected";
1546: break;
1.144 djm 1547: case DEATTACK_DOS_DETECTED:
1.205 djm 1548: emsg = "deattack denial of service detected";
1549: break;
1.201 markus 1550: default:
1.205 djm 1551: emsg = "deattack error";
1552: break;
1553: }
1554: if (emsg != NULL) {
1555: error("%s", emsg);
1556: if ((r = sshpkt_disconnect(ssh, "%s", emsg)) != 0 ||
1557: (r = ssh_packet_write_wait(ssh)) != 0)
1558: return r;
1559: return SSH_ERR_CONN_CORRUPT;
1.144 djm 1560: }
1561: }
1.62 markus 1562:
1563: /* Decrypt data to incoming_packet. */
1.201 markus 1564: sshbuf_reset(state->incoming_packet);
1565: if ((r = sshbuf_reserve(state->incoming_packet, padded_len, &p)) != 0)
1566: goto out;
1.235 djm 1567: if ((r = cipher_crypt(state->receive_context, 0, p,
1.201 markus 1568: sshbuf_ptr(state->input), padded_len, 0, 0)) != 0)
1569: goto out;
1.62 markus 1570:
1.201 markus 1571: if ((r = sshbuf_consume(state->input, padded_len)) != 0)
1572: goto out;
1.1 deraadt 1573:
1574: #ifdef PACKET_DEBUG
1.14 markus 1575: fprintf(stderr, "read_poll plain: ");
1.201 markus 1576: sshbuf_dump(state->incoming_packet, stderr);
1.1 deraadt 1577: #endif
1578:
1.14 markus 1579: /* Compute packet checksum. */
1.201 markus 1580: checksum = ssh_crc32(sshbuf_ptr(state->incoming_packet),
1581: sshbuf_len(state->incoming_packet) - 4);
1.14 markus 1582:
1583: /* Skip padding. */
1.201 markus 1584: if ((r = sshbuf_consume(state->incoming_packet, 8 - len % 8)) != 0)
1585: goto out;
1.14 markus 1586:
1587: /* Test check bytes. */
1.205 djm 1588: if (len != sshbuf_len(state->incoming_packet)) {
1589: error("%s: len %d != sshbuf_len %zd", __func__,
1.201 markus 1590: len, sshbuf_len(state->incoming_packet));
1.205 djm 1591: if ((r = sshpkt_disconnect(ssh, "invalid packet length")) != 0 ||
1592: (r = ssh_packet_write_wait(ssh)) != 0)
1593: return r;
1594: return SSH_ERR_CONN_CORRUPT;
1595: }
1.14 markus 1596:
1.201 markus 1597: cp = sshbuf_ptr(state->incoming_packet) + len - 4;
1598: stored_checksum = PEEK_U32(cp);
1.205 djm 1599: if (checksum != stored_checksum) {
1600: error("Corrupted check bytes on input");
1601: if ((r = sshpkt_disconnect(ssh, "connection corrupted")) != 0 ||
1602: (r = ssh_packet_write_wait(ssh)) != 0)
1603: return r;
1604: return SSH_ERR_CONN_CORRUPT;
1605: }
1.201 markus 1606: if ((r = sshbuf_consume_end(state->incoming_packet, 4)) < 0)
1607: goto out;
1608:
1609: if (state->packet_compression) {
1610: sshbuf_reset(state->compression_buffer);
1611: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1612: state->compression_buffer)) != 0)
1613: goto out;
1614: sshbuf_reset(state->incoming_packet);
1615: if ((r = sshbuf_putb(state->incoming_packet,
1616: state->compression_buffer)) != 0)
1617: goto out;
1618: }
1619: state->p_read.packets++;
1620: state->p_read.bytes += padded_len + 4;
1621: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1622: goto out;
1.205 djm 1623: if (*typep < SSH_MSG_MIN || *typep > SSH_MSG_MAX) {
1624: error("Invalid ssh1 packet type: %d", *typep);
1625: if ((r = sshpkt_disconnect(ssh, "invalid packet type")) != 0 ||
1626: (r = ssh_packet_write_wait(ssh)) != 0)
1627: return r;
1628: return SSH_ERR_PROTOCOL_ERROR;
1629: }
1.201 markus 1630: r = 0;
1631: out:
1632: return r;
1.1 deraadt 1633: }
1.14 markus 1634:
1.242 markus 1635: static int
1636: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1637: {
1638: struct session_state *state = ssh->state;
1639: const u_char *cp;
1640: size_t need;
1641: int r;
1642:
1643: if (ssh->kex)
1644: return SSH_ERR_INTERNAL_ERROR;
1645: *typep = SSH_MSG_NONE;
1646: cp = sshbuf_ptr(state->input);
1647: if (state->packlen == 0) {
1648: if (sshbuf_len(state->input) < 4 + 1)
1649: return 0; /* packet is incomplete */
1650: state->packlen = PEEK_U32(cp);
1651: if (state->packlen < 4 + 1 ||
1652: state->packlen > PACKET_MAX_SIZE)
1653: return SSH_ERR_MESSAGE_INCOMPLETE;
1654: }
1655: need = state->packlen + 4;
1656: if (sshbuf_len(state->input) < need)
1657: return 0; /* packet is incomplete */
1658: sshbuf_reset(state->incoming_packet);
1659: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1660: state->packlen)) != 0 ||
1661: (r = sshbuf_consume(state->input, need)) != 0 ||
1662: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1663: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1664: return r;
1665: if (ssh_packet_log_type(*typep))
1666: debug3("%s: type %u", __func__, *typep);
1667: /* sshbuf_dump(state->incoming_packet, stderr); */
1668: /* reset for next packet */
1669: state->packlen = 0;
1670: return r;
1671: }
1672:
1.201 markus 1673: int
1674: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1675: {
1.201 markus 1676: struct session_state *state = ssh->state;
1.40 markus 1677: u_int padlen, need;
1.231 djm 1678: u_char *cp;
1.201 markus 1679: u_int maclen, aadlen = 0, authlen = 0, block_size;
1680: struct sshenc *enc = NULL;
1681: struct sshmac *mac = NULL;
1682: struct sshcomp *comp = NULL;
1.200 markus 1683: int r;
1.201 markus 1684:
1.242 markus 1685: if (state->mux)
1686: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1687:
1.201 markus 1688: *typep = SSH_MSG_NONE;
1689:
1690: if (state->packet_discard)
1691: return 0;
1692:
1693: if (state->newkeys[MODE_IN] != NULL) {
1694: enc = &state->newkeys[MODE_IN]->enc;
1695: mac = &state->newkeys[MODE_IN]->mac;
1696: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1697: /* disable mac for authenticated encryption */
1698: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1699: mac = NULL;
1.25 markus 1700: }
1701: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1702: block_size = enc ? enc->block_size : 8;
1.180 markus 1703: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1704:
1.201 markus 1705: if (aadlen && state->packlen == 0) {
1.235 djm 1706: if (cipher_get_length(state->receive_context,
1.201 markus 1707: &state->packlen, state->p_read.seqnr,
1708: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1709: return 0;
1710: if (state->packlen < 1 + 4 ||
1711: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1712: #ifdef PACKET_DEBUG
1.201 markus 1713: sshbuf_dump(state->input, stderr);
1.178 markus 1714: #endif
1.201 markus 1715: logit("Bad packet length %u.", state->packlen);
1716: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1717: return r;
1.217 djm 1718: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1719: }
1.201 markus 1720: sshbuf_reset(state->incoming_packet);
1721: } else if (state->packlen == 0) {
1.25 markus 1722: /*
1723: * check if input size is less than the cipher block size,
1724: * decrypt first block and extract length of incoming packet
1725: */
1.201 markus 1726: if (sshbuf_len(state->input) < block_size)
1727: return 0;
1728: sshbuf_reset(state->incoming_packet);
1729: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1730: &cp)) != 0)
1731: goto out;
1.235 djm 1732: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1733: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1734: block_size, 0, 0)) != 0)
1735: goto out;
1736: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1737: if (state->packlen < 1 + 4 ||
1738: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1739: #ifdef PACKET_DEBUG
1.201 markus 1740: fprintf(stderr, "input: \n");
1741: sshbuf_dump(state->input, stderr);
1742: fprintf(stderr, "incoming_packet: \n");
1743: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1744: #endif
1.201 markus 1745: logit("Bad packet length %u.", state->packlen);
1.234 markus 1746: return ssh_packet_start_discard(ssh, enc, mac, 0,
1747: PACKET_MAX_SIZE);
1.25 markus 1748: }
1.201 markus 1749: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1750: goto out;
1.25 markus 1751: }
1.201 markus 1752: DBG(debug("input: packet len %u", state->packlen+4));
1753:
1.178 markus 1754: if (aadlen) {
1755: /* only the payload is encrypted */
1.201 markus 1756: need = state->packlen;
1.178 markus 1757: } else {
1758: /*
1759: * the payload size and the payload are encrypted, but we
1760: * have a partial packet of block_size bytes
1761: */
1.201 markus 1762: need = 4 + state->packlen - block_size;
1.178 markus 1763: }
1.180 markus 1764: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1765: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1766: if (need % block_size != 0) {
1767: logit("padding error: need %d block %d mod %d",
1.25 markus 1768: need, block_size, need % block_size);
1.234 markus 1769: return ssh_packet_start_discard(ssh, enc, mac, 0,
1770: PACKET_MAX_SIZE - block_size);
1.158 markus 1771: }
1.25 markus 1772: /*
1773: * check if the entire packet has been received and
1.178 markus 1774: * decrypt into incoming_packet:
1775: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1776: * 'need' bytes are encrypted, followed by either
1777: * 'authlen' bytes of authentication tag or
1.178 markus 1778: * 'maclen' bytes of message authentication code.
1.25 markus 1779: */
1.201 markus 1780: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1781: return 0; /* packet is incomplete */
1.25 markus 1782: #ifdef PACKET_DEBUG
1783: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1784: sshbuf_dump(state->input, stderr);
1.25 markus 1785: #endif
1.231 djm 1786: /* EtM: check mac over encrypted input */
1.201 markus 1787: if (mac && mac->enabled && mac->etm) {
1.231 djm 1788: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1789: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1790: sshbuf_ptr(state->input) + aadlen + need + authlen,
1791: maclen)) != 0) {
1792: if (r == SSH_ERR_MAC_INVALID)
1793: logit("Corrupted MAC on input.");
1.201 markus 1794: goto out;
1.231 djm 1795: }
1.201 markus 1796: }
1797: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1798: &cp)) != 0)
1799: goto out;
1.235 djm 1800: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1801: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1802: goto out;
1803: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1804: goto out;
1.29 markus 1805: if (mac && mac->enabled) {
1.231 djm 1806: /* Not EtM: check MAC over cleartext */
1807: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1808: sshbuf_ptr(state->incoming_packet),
1809: sshbuf_len(state->incoming_packet),
1810: sshbuf_ptr(state->input), maclen)) != 0) {
1811: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1812: goto out;
1.159 markus 1813: logit("Corrupted MAC on input.");
1.247 markus 1814: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1815: return SSH_ERR_INTERNAL_ERROR;
1816: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1817: sshbuf_len(state->incoming_packet),
1.247 markus 1818: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1819: }
1.231 djm 1820: /* Remove MAC from input buffer */
1.201 markus 1821: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1822: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1823: goto out;
1.25 markus 1824: }
1.77 djm 1825: if (seqnr_p != NULL)
1.201 markus 1826: *seqnr_p = state->p_read.seqnr;
1827: if (++state->p_read.seqnr == 0)
1.106 itojun 1828: logit("incoming seqnr wraps around");
1.201 markus 1829: if (++state->p_read.packets == 0)
1830: if (!(ssh->compat & SSH_BUG_NOREKEY))
1831: return SSH_ERR_NEED_REKEY;
1832: state->p_read.blocks += (state->packlen + 4) / block_size;
1833: state->p_read.bytes += state->packlen + 4;
1.25 markus 1834:
1835: /* get padlen */
1.201 markus 1836: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1837: DBG(debug("input: padlen %d", padlen));
1.205 djm 1838: if (padlen < 4) {
1839: if ((r = sshpkt_disconnect(ssh,
1840: "Corrupted padlen %d on input.", padlen)) != 0 ||
1841: (r = ssh_packet_write_wait(ssh)) != 0)
1842: return r;
1843: return SSH_ERR_CONN_CORRUPT;
1844: }
1.25 markus 1845:
1846: /* skip packet size + padlen, discard padding */
1.201 markus 1847: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1848: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1849: goto out;
1.25 markus 1850:
1.201 markus 1851: DBG(debug("input: len before de-compress %zd",
1852: sshbuf_len(state->incoming_packet)));
1.25 markus 1853: if (comp && comp->enabled) {
1.201 markus 1854: sshbuf_reset(state->compression_buffer);
1855: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1856: state->compression_buffer)) != 0)
1857: goto out;
1858: sshbuf_reset(state->incoming_packet);
1859: if ((r = sshbuf_putb(state->incoming_packet,
1860: state->compression_buffer)) != 0)
1861: goto out;
1862: DBG(debug("input: len after de-compress %zd",
1863: sshbuf_len(state->incoming_packet)));
1.25 markus 1864: }
1865: /*
1866: * get packet type, implies consume.
1867: * return length of payload (without type field)
1868: */
1.201 markus 1869: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1870: goto out;
1.226 djm 1871: if (ssh_packet_log_type(*typep))
1872: debug3("receive packet: type %u", *typep);
1.205 djm 1873: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1874: if ((r = sshpkt_disconnect(ssh,
1875: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1876: (r = ssh_packet_write_wait(ssh)) != 0)
1877: return r;
1878: return SSH_ERR_PROTOCOL_ERROR;
1879: }
1.243 djm 1880: if (state->hook_in != NULL &&
1881: (r = state->hook_in(ssh, state->incoming_packet, typep,
1882: state->hook_in_ctx)) != 0)
1883: return r;
1.238 markus 1884: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1885: r = ssh_packet_enable_delayed_compress(ssh);
1886: else
1887: r = 0;
1.25 markus 1888: #ifdef PACKET_DEBUG
1.201 markus 1889: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1890: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1891: #endif
1.62 markus 1892: /* reset for next packet */
1.201 markus 1893: state->packlen = 0;
1.228 djm 1894:
1895: /* do we need to rekey? */
1896: if (ssh_packet_need_rekeying(ssh, 0)) {
1897: debug3("%s: rekex triggered", __func__);
1898: if ((r = kex_start_rekex(ssh)) != 0)
1899: return r;
1900: }
1.201 markus 1901: out:
1902: return r;
1.25 markus 1903: }
1904:
1905: int
1.201 markus 1906: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1907: {
1.201 markus 1908: struct session_state *state = ssh->state;
1.96 deraadt 1909: u_int reason, seqnr;
1.201 markus 1910: int r;
1911: u_char *msg;
1.62 markus 1912:
1.25 markus 1913: for (;;) {
1.201 markus 1914: msg = NULL;
1.62 markus 1915: if (compat20) {
1.201 markus 1916: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1917: if (r != 0)
1918: return r;
1919: if (*typep) {
1920: state->keep_alive_timeouts = 0;
1921: DBG(debug("received packet type %d", *typep));
1.153 djm 1922: }
1.201 markus 1923: switch (*typep) {
1.150 dtucker 1924: case SSH2_MSG_IGNORE:
1.151 dtucker 1925: debug3("Received SSH2_MSG_IGNORE");
1.150 dtucker 1926: break;
1.25 markus 1927: case SSH2_MSG_DEBUG:
1.201 markus 1928: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1929: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1930: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1.219 mmcc 1931: free(msg);
1.201 markus 1932: return r;
1933: }
1.25 markus 1934: debug("Remote: %.900s", msg);
1.186 djm 1935: free(msg);
1.25 markus 1936: break;
1937: case SSH2_MSG_DISCONNECT:
1.201 markus 1938: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1939: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1940: return r;
1.182 djm 1941: /* Ignore normal client exit notifications */
1.201 markus 1942: do_log2(ssh->state->server_side &&
1.182 djm 1943: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1944: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1.220 djm 1945: "Received disconnect from %s port %d:"
1946: "%u: %.400s", ssh_remote_ipaddr(ssh),
1947: ssh_remote_port(ssh), reason, msg);
1.186 djm 1948: free(msg);
1.201 markus 1949: return SSH_ERR_DISCONNECTED;
1.84 markus 1950: case SSH2_MSG_UNIMPLEMENTED:
1.201 markus 1951: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1952: return r;
1.96 deraadt 1953: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1954: seqnr);
1.150 dtucker 1955: break;
1.25 markus 1956: default:
1.201 markus 1957: return 0;
1.48 stevesk 1958: }
1.25 markus 1959: } else {
1.201 markus 1960: r = ssh_packet_read_poll1(ssh, typep);
1961: switch (*typep) {
1.188 djm 1962: case SSH_MSG_NONE:
1963: return SSH_MSG_NONE;
1.25 markus 1964: case SSH_MSG_IGNORE:
1965: break;
1966: case SSH_MSG_DEBUG:
1.201 markus 1967: if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1968: return r;
1.25 markus 1969: debug("Remote: %.900s", msg);
1.186 djm 1970: free(msg);
1.25 markus 1971: break;
1972: case SSH_MSG_DISCONNECT:
1.201 markus 1973: if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1974: return r;
1.220 djm 1975: error("Received disconnect from %s port %d: "
1976: "%.400s", ssh_remote_ipaddr(ssh),
1977: ssh_remote_port(ssh), msg);
1.201 markus 1978: free(msg);
1979: return SSH_ERR_DISCONNECTED;
1.25 markus 1980: default:
1.201 markus 1981: DBG(debug("received packet type %d", *typep));
1982: return 0;
1.48 stevesk 1983: }
1.25 markus 1984: }
1985: }
1986: }
1987:
1.16 markus 1988: /*
1989: * Buffers the given amount of input characters. This is intended to be used
1990: * together with packet_read_poll.
1991: */
1.1 deraadt 1992:
1.204 djm 1993: int
1.201 markus 1994: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1995: {
1.201 markus 1996: struct session_state *state = ssh->state;
1997: int r;
1998:
1999: if (state->packet_discard) {
2000: state->keep_alive_timeouts = 0; /* ?? */
2001: if (len >= state->packet_discard) {
2002: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 2003: return r;
1.201 markus 2004: }
2005: state->packet_discard -= len;
1.204 djm 2006: return 0;
1.159 markus 2007: }
1.201 markus 2008: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 2009: return r;
2010:
2011: return 0;
1.28 markus 2012: }
2013:
2014: int
1.201 markus 2015: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 2016: {
1.201 markus 2017: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 2018: }
2019:
1.16 markus 2020: /*
2021: * Sends a diagnostic message from the server to the client. This message
2022: * can be sent at any time (but not while constructing another message). The
2023: * message is printed immediately, but only if the client is being executed
2024: * in verbose mode. These messages are primarily intended to ease debugging
2025: * authentication problems. The length of the formatted message must not
1.205 djm 2026: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 2027: */
1.2 provos 2028: void
1.201 markus 2029: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 2030: {
1.14 markus 2031: char buf[1024];
2032: va_list args;
1.201 markus 2033: int r;
1.39 markus 2034:
1.201 markus 2035: if (compat20 && (ssh->compat & SSH_BUG_DEBUG))
1.39 markus 2036: return;
1.14 markus 2037:
2038: va_start(args, fmt);
2039: vsnprintf(buf, sizeof(buf), fmt, args);
2040: va_end(args);
2041:
1.30 markus 2042: if (compat20) {
1.201 markus 2043: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
2044: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
2045: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2046: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2047: (r = sshpkt_send(ssh)) != 0)
2048: fatal("%s: %s", __func__, ssh_err(r));
1.30 markus 2049: } else {
1.201 markus 2050: if ((r = sshpkt_start(ssh, SSH_MSG_DEBUG)) != 0 ||
2051: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2052: (r = sshpkt_send(ssh)) != 0)
2053: fatal("%s: %s", __func__, ssh_err(r));
1.30 markus 2054: }
1.205 djm 2055: if ((r = ssh_packet_write_wait(ssh)) != 0)
2056: fatal("%s: %s", __func__, ssh_err(r));
2057: }
2058:
1.245 djm 2059: static void
2060: fmt_connection_id(struct ssh *ssh, char *s, size_t l)
2061: {
2062: snprintf(s, l, "%.200s%s%s port %d",
2063: ssh->log_preamble ? ssh->log_preamble : "",
2064: ssh->log_preamble ? " " : "",
2065: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
2066: }
2067:
1.205 djm 2068: /*
2069: * Pretty-print connection-terminating errors and exit.
2070: */
2071: void
2072: sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
2073: {
1.245 djm 2074: char remote_id[512];
2075:
2076: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
2077:
1.205 djm 2078: switch (r) {
2079: case SSH_ERR_CONN_CLOSED:
1.245 djm 2080: logdie("Connection closed by %s", remote_id);
1.205 djm 2081: case SSH_ERR_CONN_TIMEOUT:
1.245 djm 2082: logdie("Connection %s %s timed out",
2083: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 2084: case SSH_ERR_DISCONNECTED:
1.245 djm 2085: logdie("Disconnected from %s", remote_id);
1.212 djm 2086: case SSH_ERR_SYSTEM_ERROR:
1.232 dtucker 2087: if (errno == ECONNRESET)
1.245 djm 2088: logdie("Connection reset by %s", remote_id);
1.213 djm 2089: /* FALLTHROUGH */
2090: case SSH_ERR_NO_CIPHER_ALG_MATCH:
2091: case SSH_ERR_NO_MAC_ALG_MATCH:
2092: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
2093: case SSH_ERR_NO_KEX_ALG_MATCH:
2094: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
2095: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.245 djm 2096: logdie("Unable to negotiate with %s: %s. "
2097: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 2098: ssh->kex->failed_choice);
1.212 djm 2099: }
2100: /* FALLTHROUGH */
1.205 djm 2101: default:
1.245 djm 2102: logdie("%s%sConnection %s %s: %s",
1.205 djm 2103: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 2104: ssh->state->server_side ? "from" : "to",
1.245 djm 2105: remote_id, ssh_err(r));
1.205 djm 2106: }
1.1 deraadt 2107: }
2108:
1.16 markus 2109: /*
2110: * Logs the error plus constructs and sends a disconnect packet, closes the
2111: * connection, and exits. This function never returns. The error message
2112: * should not contain a newline. The length of the formatted message must
2113: * not exceed 1024 bytes.
2114: */
1.2 provos 2115: void
1.201 markus 2116: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 2117: {
1.245 djm 2118: char buf[1024], remote_id[512];
1.14 markus 2119: va_list args;
2120: static int disconnecting = 0;
1.201 markus 2121: int r;
1.97 deraadt 2122:
1.14 markus 2123: if (disconnecting) /* Guard against recursive invocations. */
2124: fatal("packet_disconnect called recursively.");
2125: disconnecting = 1;
2126:
1.16 markus 2127: /*
2128: * Format the message. Note that the caller must make sure the
2129: * message is of limited size.
2130: */
1.245 djm 2131: fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 2132: va_start(args, fmt);
2133: vsnprintf(buf, sizeof(buf), fmt, args);
2134: va_end(args);
2135:
1.99 markus 2136: /* Display the error locally */
1.245 djm 2137: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 2138:
1.205 djm 2139: /*
2140: * Send the disconnect message to the other side, and wait
2141: * for it to get sent.
2142: */
2143: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
2144: sshpkt_fatal(ssh, __func__, r);
2145:
2146: if ((r = ssh_packet_write_wait(ssh)) != 0)
2147: sshpkt_fatal(ssh, __func__, r);
1.14 markus 2148:
2149: /* Close the connection. */
1.201 markus 2150: ssh_packet_close(ssh);
1.112 markus 2151: cleanup_exit(255);
1.1 deraadt 2152: }
2153:
1.205 djm 2154: /*
2155: * Checks if there is any buffered output, and tries to write some of
2156: * the output.
2157: */
2158: int
1.201 markus 2159: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 2160: {
1.201 markus 2161: struct session_state *state = ssh->state;
2162: int len = sshbuf_len(state->output);
1.222 markus 2163: int r;
1.97 deraadt 2164:
1.14 markus 2165: if (len > 0) {
1.222 markus 2166: len = write(state->connection_out,
2167: sshbuf_ptr(state->output), len);
1.156 djm 2168: if (len == -1) {
2169: if (errno == EINTR || errno == EAGAIN)
1.205 djm 2170: return 0;
2171: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 2172: }
1.222 markus 2173: if (len == 0)
1.205 djm 2174: return SSH_ERR_CONN_CLOSED;
1.201 markus 2175: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 2176: return r;
1.14 markus 2177: }
1.205 djm 2178: return 0;
1.1 deraadt 2179: }
2180:
1.16 markus 2181: /*
2182: * Calls packet_write_poll repeatedly until all pending output data has been
2183: * written.
2184: */
1.205 djm 2185: int
1.201 markus 2186: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 2187: {
1.56 millert 2188: fd_set *setp;
1.205 djm 2189: int ret, r, ms_remain = 0;
1.154 dtucker 2190: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 2191: struct session_state *state = ssh->state;
1.56 millert 2192:
1.214 deraadt 2193: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 2194: NFDBITS), sizeof(fd_mask));
1.201 markus 2195: if (setp == NULL)
1.205 djm 2196: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 2197: if ((r = ssh_packet_write_poll(ssh)) != 0) {
2198: free(setp);
1.215 djm 2199: return r;
1.216 gsoares 2200: }
1.201 markus 2201: while (ssh_packet_have_data_to_write(ssh)) {
2202: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 2203: NFDBITS) * sizeof(fd_mask));
1.201 markus 2204: FD_SET(state->connection_out, setp);
1.154 dtucker 2205:
1.201 markus 2206: if (state->packet_timeout_ms > 0) {
2207: ms_remain = state->packet_timeout_ms;
1.154 dtucker 2208: timeoutp = &timeout;
2209: }
2210: for (;;) {
1.201 markus 2211: if (state->packet_timeout_ms != -1) {
1.154 dtucker 2212: ms_to_timeval(&timeout, ms_remain);
2213: gettimeofday(&start, NULL);
2214: }
1.201 markus 2215: if ((ret = select(state->connection_out + 1,
1.161 andreas 2216: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 2217: break;
1.161 andreas 2218: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 2219: break;
1.201 markus 2220: if (state->packet_timeout_ms == -1)
1.154 dtucker 2221: continue;
2222: ms_subtract_diff(&start, &ms_remain);
2223: if (ms_remain <= 0) {
2224: ret = 0;
2225: break;
2226: }
2227: }
2228: if (ret == 0) {
1.205 djm 2229: free(setp);
2230: return SSH_ERR_CONN_TIMEOUT;
2231: }
2232: if ((r = ssh_packet_write_poll(ssh)) != 0) {
2233: free(setp);
2234: return r;
1.154 dtucker 2235: }
1.14 markus 2236: }
1.186 djm 2237: free(setp);
1.205 djm 2238: return 0;
1.1 deraadt 2239: }
2240:
2241: /* Returns true if there is buffered data to write to the connection. */
2242:
1.2 provos 2243: int
1.201 markus 2244: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 2245: {
1.201 markus 2246: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 2247: }
2248:
2249: /* Returns true if there is not too much data to write to the connection. */
2250:
1.2 provos 2251: int
1.201 markus 2252: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 2253: {
1.201 markus 2254: if (ssh->state->interactive_mode)
2255: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 2256: else
1.201 markus 2257: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 2258: }
2259:
1.201 markus 2260: void
2261: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 2262: {
1.201 markus 2263: if (!ssh_packet_connection_is_on_socket(ssh))
1.101 markus 2264: return;
1.201 markus 2265: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 2266: case AF_INET:
2267: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 2268: if (setsockopt(ssh->state->connection_in,
1.173 djm 2269: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
2270: error("setsockopt IP_TOS %d: %.100s:",
2271: tos, strerror(errno));
2272: break;
2273: case AF_INET6:
2274: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 2275: if (setsockopt(ssh->state->connection_in,
1.173 djm 2276: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2277: error("setsockopt IPV6_TCLASS %d: %.100s:",
2278: tos, strerror(errno));
2279: break;
2280: }
1.101 markus 2281: }
2282:
1.1 deraadt 2283: /* Informs that the current session is interactive. Sets IP flags for that. */
2284:
1.2 provos 2285: void
1.201 markus 2286: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2287: {
1.201 markus 2288: struct session_state *state = ssh->state;
2289:
2290: if (state->set_interactive_called)
1.43 markus 2291: return;
1.201 markus 2292: state->set_interactive_called = 1;
1.1 deraadt 2293:
1.14 markus 2294: /* Record that we are in interactive mode. */
1.201 markus 2295: state->interactive_mode = interactive;
1.1 deraadt 2296:
1.19 markus 2297: /* Only set socket options if using a socket. */
1.201 markus 2298: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2299: return;
1.201 markus 2300: set_nodelay(state->connection_in);
2301: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2302: qos_bulk);
1.1 deraadt 2303: }
2304:
2305: /* Returns true if the current connection is interactive. */
2306:
1.2 provos 2307: int
1.201 markus 2308: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2309: {
1.201 markus 2310: return ssh->state->interactive_mode;
1.12 markus 2311: }
2312:
1.113 deraadt 2313: int
1.201 markus 2314: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2315: {
1.201 markus 2316: struct session_state *state = ssh->state;
2317:
2318: if (state->set_maxsize_called) {
1.106 itojun 2319: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2320: state->max_packet_size, s);
1.14 markus 2321: return -1;
2322: }
2323: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2324: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2325: return -1;
2326: }
1.201 markus 2327: state->set_maxsize_called = 1;
1.66 markus 2328: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2329: state->max_packet_size = s;
1.14 markus 2330: return s;
1.53 markus 2331: }
2332:
1.161 andreas 2333: int
1.201 markus 2334: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2335: {
1.201 markus 2336: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2337: }
2338:
2339: void
1.201 markus 2340: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2341: {
1.201 markus 2342: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2343: }
2344:
2345: u_int
1.201 markus 2346: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2347: {
1.201 markus 2348: return ssh->state->max_packet_size;
1.71 markus 2349: }
2350:
1.53 markus 2351: /*
2352: * 9.2. Ignored Data Message
1.61 markus 2353: *
1.53 markus 2354: * byte SSH_MSG_IGNORE
2355: * string data
1.61 markus 2356: *
1.53 markus 2357: * All implementations MUST understand (and ignore) this message at any
2358: * time (after receiving the protocol version). No implementation is
2359: * required to send them. This message can be used as an additional
2360: * protection measure against advanced traffic analysis techniques.
2361: */
1.54 markus 2362: void
1.201 markus 2363: ssh_packet_send_ignore(struct ssh *ssh, int nbytes)
1.54 markus 2364: {
1.115 avsm 2365: u_int32_t rnd = 0;
1.201 markus 2366: int r, i;
1.54 markus 2367:
1.201 markus 2368: if ((r = sshpkt_start(ssh, compat20 ?
2369: SSH2_MSG_IGNORE : SSH_MSG_IGNORE)) != 0 ||
2370: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2371: fatal("%s: %s", __func__, ssh_err(r));
1.75 deraadt 2372: for (i = 0; i < nbytes; i++) {
1.53 markus 2373: if (i % 4 == 0)
1.115 avsm 2374: rnd = arc4random();
1.201 markus 2375: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2376: fatal("%s: %s", __func__, ssh_err(r));
1.115 avsm 2377: rnd >>= 8;
1.53 markus 2378: }
1.105 markus 2379: }
2380:
2381: void
1.244 dtucker 2382: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2383: {
1.244 dtucker 2384: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2385: (unsigned int)seconds);
1.201 markus 2386: ssh->state->rekey_limit = bytes;
2387: ssh->state->rekey_interval = seconds;
1.184 dtucker 2388: }
2389:
2390: time_t
1.201 markus 2391: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2392: {
2393: time_t seconds;
2394:
1.201 markus 2395: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2396: monotime();
1.185 dtucker 2397: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2398: }
2399:
2400: void
1.201 markus 2401: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2402: {
1.201 markus 2403: ssh->state->server_side = 1;
1.118 markus 2404: }
2405:
2406: void
1.201 markus 2407: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2408: {
1.201 markus 2409: ssh->state->after_authentication = 1;
1.161 andreas 2410: }
2411:
2412: void *
1.201 markus 2413: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2414: {
1.201 markus 2415: return (void *)ssh->state->input;
1.161 andreas 2416: }
2417:
2418: void *
1.201 markus 2419: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2420: {
1.201 markus 2421: return (void *)ssh->state->output;
1.166 andreas 2422: }
2423:
1.196 markus 2424: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2425: static int
2426: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2427: {
1.239 djm 2428: int r;
1.196 markus 2429:
2430: debug("%s: called", __func__);
2431: /* This was set in net child, but is not visible in user child */
1.201 markus 2432: ssh->state->after_authentication = 1;
2433: ssh->state->rekeying = 0;
1.239 djm 2434: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2435: return r;
1.201 markus 2436: return 0;
2437: }
2438:
2439: /* Packet state (de-)serialization for privsep */
2440:
2441: /* turn kex into a blob for packet state serialization */
2442: static int
2443: kex_to_blob(struct sshbuf *m, struct kex *kex)
2444: {
2445: int r;
2446:
2447: if ((r = sshbuf_put_string(m, kex->session_id,
2448: kex->session_id_len)) != 0 ||
2449: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2450: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2451: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2452: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2453: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2454: (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2455: (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2456: (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2457: return r;
2458: return 0;
2459: }
2460:
2461: /* turn key exchange results into a blob for packet state serialization */
2462: static int
2463: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2464: {
2465: struct sshbuf *b;
2466: struct sshcipher_ctx *cc;
2467: struct sshcomp *comp;
2468: struct sshenc *enc;
2469: struct sshmac *mac;
2470: struct newkeys *newkey;
2471: int r;
2472:
2473: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2474: return SSH_ERR_INTERNAL_ERROR;
2475: enc = &newkey->enc;
2476: mac = &newkey->mac;
2477: comp = &newkey->comp;
1.235 djm 2478: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2479: ssh->state->receive_context;
1.201 markus 2480: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2481: return r;
2482: if ((b = sshbuf_new()) == NULL)
2483: return SSH_ERR_ALLOC_FAIL;
2484: /* The cipher struct is constant and shared, you export pointer */
2485: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2486: (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2487: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2488: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2489: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2490: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2491: goto out;
2492: if (cipher_authlen(enc->cipher) == 0) {
2493: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2494: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2495: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2496: goto out;
2497: }
2498: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2499: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2500: goto out;
2501: r = sshbuf_put_stringb(m, b);
2502: out:
1.221 mmcc 2503: sshbuf_free(b);
1.201 markus 2504: return r;
2505: }
2506:
2507: /* serialize packet state into a blob */
2508: int
2509: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2510: {
2511: struct session_state *state = ssh->state;
2512: u_char *p;
2513: size_t slen, rlen;
2514: int r, ssh1cipher;
2515:
2516: if (!compat20) {
1.235 djm 2517: ssh1cipher = cipher_ctx_get_number(state->receive_context);
2518: slen = cipher_get_keyiv_len(state->send_context);
2519: rlen = cipher_get_keyiv_len(state->receive_context);
1.201 markus 2520: if ((r = sshbuf_put_u32(m, state->remote_protocol_flags)) != 0 ||
2521: (r = sshbuf_put_u32(m, ssh1cipher)) != 0 ||
2522: (r = sshbuf_put_string(m, state->ssh1_key, state->ssh1_keylen)) != 0 ||
2523: (r = sshbuf_put_u32(m, slen)) != 0 ||
2524: (r = sshbuf_reserve(m, slen, &p)) != 0 ||
1.235 djm 2525: (r = cipher_get_keyiv(state->send_context, p, slen)) != 0 ||
1.201 markus 2526: (r = sshbuf_put_u32(m, rlen)) != 0 ||
2527: (r = sshbuf_reserve(m, rlen, &p)) != 0 ||
1.235 djm 2528: (r = cipher_get_keyiv(state->receive_context, p, rlen)) != 0)
1.201 markus 2529: return r;
2530: } else {
2531: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2532: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2533: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
1.224 dtucker 2534: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
1.208 markus 2535: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
1.201 markus 2536: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2537: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2538: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2539: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2540: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2541: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2542: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
2543: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0)
2544: return r;
2545: }
2546:
1.235 djm 2547: slen = cipher_get_keycontext(state->send_context, NULL);
2548: rlen = cipher_get_keycontext(state->receive_context, NULL);
1.201 markus 2549: if ((r = sshbuf_put_u32(m, slen)) != 0 ||
2550: (r = sshbuf_reserve(m, slen, &p)) != 0)
2551: return r;
1.235 djm 2552: if (cipher_get_keycontext(state->send_context, p) != (int)slen)
1.201 markus 2553: return SSH_ERR_INTERNAL_ERROR;
2554: if ((r = sshbuf_put_u32(m, rlen)) != 0 ||
2555: (r = sshbuf_reserve(m, rlen, &p)) != 0)
2556: return r;
1.235 djm 2557: if (cipher_get_keycontext(state->receive_context, p) != (int)rlen)
1.201 markus 2558: return SSH_ERR_INTERNAL_ERROR;
1.239 djm 2559: if ((r = sshbuf_put_stringb(m, state->input)) != 0 ||
1.201 markus 2560: (r = sshbuf_put_stringb(m, state->output)) != 0)
2561: return r;
2562:
2563: return 0;
2564: }
2565:
2566: /* restore key exchange results from blob for packet state de-serialization */
2567: static int
2568: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2569: {
2570: struct sshbuf *b = NULL;
2571: struct sshcomp *comp;
2572: struct sshenc *enc;
2573: struct sshmac *mac;
2574: struct newkeys *newkey = NULL;
2575: size_t keylen, ivlen, maclen;
2576: int r;
2577:
2578: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2579: r = SSH_ERR_ALLOC_FAIL;
2580: goto out;
2581: }
2582: if ((r = sshbuf_froms(m, &b)) != 0)
2583: goto out;
2584: #ifdef DEBUG_PK
2585: sshbuf_dump(b, stderr);
2586: #endif
2587: enc = &newkey->enc;
2588: mac = &newkey->mac;
2589: comp = &newkey->comp;
2590:
2591: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2592: (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2593: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2594: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2595: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2596: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2597: goto out;
2598: if (cipher_authlen(enc->cipher) == 0) {
2599: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2600: goto out;
2601: if ((r = mac_setup(mac, mac->name)) != 0)
2602: goto out;
2603: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2604: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2605: goto out;
2606: if (maclen > mac->key_len) {
2607: r = SSH_ERR_INVALID_FORMAT;
2608: goto out;
2609: }
2610: mac->key_len = maclen;
2611: }
2612: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2613: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2614: goto out;
2615: if (enc->name == NULL ||
2616: cipher_by_name(enc->name) != enc->cipher) {
2617: r = SSH_ERR_INVALID_FORMAT;
2618: goto out;
2619: }
2620: if (sshbuf_len(b) != 0) {
2621: r = SSH_ERR_INVALID_FORMAT;
2622: goto out;
2623: }
2624: enc->key_len = keylen;
2625: enc->iv_len = ivlen;
2626: ssh->kex->newkeys[mode] = newkey;
2627: newkey = NULL;
2628: r = 0;
2629: out:
1.219 mmcc 2630: free(newkey);
1.221 mmcc 2631: sshbuf_free(b);
1.201 markus 2632: return r;
2633: }
2634:
2635: /* restore kex from blob for packet state de-serialization */
2636: static int
2637: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2638: {
2639: struct kex *kex;
2640: int r;
2641:
2642: if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2643: (kex->my = sshbuf_new()) == NULL ||
2644: (kex->peer = sshbuf_new()) == NULL) {
2645: r = SSH_ERR_ALLOC_FAIL;
2646: goto out;
2647: }
2648: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2649: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2650: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2651: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2652: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2653: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2654: (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2655: (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2656: (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2657: goto out;
2658: kex->server = 1;
2659: kex->done = 1;
2660: r = 0;
2661: out:
2662: if (r != 0 || kexp == NULL) {
2663: if (kex != NULL) {
1.221 mmcc 2664: sshbuf_free(kex->my);
2665: sshbuf_free(kex->peer);
1.201 markus 2666: free(kex);
2667: }
2668: if (kexp != NULL)
2669: *kexp = NULL;
2670: } else {
2671: *kexp = kex;
2672: }
2673: return r;
2674: }
2675:
2676: /*
2677: * Restore packet state from content of blob 'm' (de-serialization).
2678: * Note that 'm' will be partially consumed on parsing or any other errors.
2679: */
2680: int
2681: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2682: {
2683: struct session_state *state = ssh->state;
2684: const u_char *ssh1key, *ivin, *ivout, *keyin, *keyout, *input, *output;
2685: size_t ssh1keylen, rlen, slen, ilen, olen;
2686: int r;
2687: u_int ssh1cipher = 0;
2688:
2689: if (!compat20) {
2690: if ((r = sshbuf_get_u32(m, &state->remote_protocol_flags)) != 0 ||
2691: (r = sshbuf_get_u32(m, &ssh1cipher)) != 0 ||
2692: (r = sshbuf_get_string_direct(m, &ssh1key, &ssh1keylen)) != 0 ||
2693: (r = sshbuf_get_string_direct(m, &ivout, &slen)) != 0 ||
2694: (r = sshbuf_get_string_direct(m, &ivin, &rlen)) != 0)
2695: return r;
2696: if (ssh1cipher > INT_MAX)
2697: return SSH_ERR_KEY_UNKNOWN_CIPHER;
2698: ssh_packet_set_encryption_key(ssh, ssh1key, ssh1keylen,
2699: (int)ssh1cipher);
1.235 djm 2700: if (cipher_get_keyiv_len(state->send_context) != (int)slen ||
2701: cipher_get_keyiv_len(state->receive_context) != (int)rlen)
1.201 markus 2702: return SSH_ERR_INVALID_FORMAT;
1.235 djm 2703: if ((r = cipher_set_keyiv(state->send_context, ivout)) != 0 ||
2704: (r = cipher_set_keyiv(state->receive_context, ivin)) != 0)
1.201 markus 2705: return r;
2706: } else {
2707: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2708: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2709: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
1.224 dtucker 2710: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
1.208 markus 2711: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
1.201 markus 2712: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2713: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2714: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2715: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2716: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2717: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2718: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2719: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2720: return r;
1.208 markus 2721: /*
2722: * We set the time here so that in post-auth privsep slave we
2723: * count from the completion of the authentication.
2724: */
2725: state->rekey_time = monotime();
1.201 markus 2726: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2727: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2728: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2729: return r;
2730: }
2731: if ((r = sshbuf_get_string_direct(m, &keyout, &slen)) != 0 ||
2732: (r = sshbuf_get_string_direct(m, &keyin, &rlen)) != 0)
2733: return r;
1.235 djm 2734: if (cipher_get_keycontext(state->send_context, NULL) != (int)slen ||
2735: cipher_get_keycontext(state->receive_context, NULL) != (int)rlen)
1.201 markus 2736: return SSH_ERR_INVALID_FORMAT;
1.235 djm 2737: cipher_set_keycontext(state->send_context, keyout);
2738: cipher_set_keycontext(state->receive_context, keyin);
1.201 markus 2739:
1.239 djm 2740: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2741: return r;
2742:
2743: sshbuf_reset(state->input);
2744: sshbuf_reset(state->output);
2745: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2746: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2747: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2748: (r = sshbuf_put(state->output, output, olen)) != 0)
2749: return r;
2750:
2751: if (sshbuf_len(m))
2752: return SSH_ERR_INVALID_FORMAT;
2753: debug3("%s: done", __func__);
2754: return 0;
2755: }
2756:
2757: /* NEW API */
2758:
2759: /* put data to the outgoing packet */
2760:
2761: int
2762: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2763: {
2764: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2765: }
2766:
2767: int
2768: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2769: {
2770: return sshbuf_putb(ssh->state->outgoing_packet, b);
2771: }
2772:
2773: int
2774: sshpkt_put_u8(struct ssh *ssh, u_char val)
2775: {
2776: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2777: }
2778:
2779: int
2780: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2781: {
2782: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2783: }
2784:
2785: int
2786: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2787: {
2788: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2789: }
2790:
2791: int
2792: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2793: {
2794: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2795: }
2796:
2797: int
2798: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2799: {
2800: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2801: }
2802:
2803: int
2804: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2805: {
2806: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2807: }
2808:
1.211 djm 2809: #ifdef WITH_OPENSSL
1.201 markus 2810: int
2811: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2812: {
2813: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2814: }
2815:
2816:
2817: int
2818: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2819: {
2820: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2821: }
1.211 djm 2822: #endif /* WITH_OPENSSL */
1.201 markus 2823:
2824: /* fetch data from the incoming packet */
2825:
2826: int
2827: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2828: {
2829: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2830: }
2831:
2832: int
2833: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2834: {
2835: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2836: }
2837:
2838: int
2839: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2840: {
2841: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2842: }
2843:
2844: int
2845: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2846: {
2847: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2848: }
2849:
2850: int
2851: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2852: {
2853: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2854: }
2855:
2856: int
2857: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2858: {
2859: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2860: }
2861:
2862: int
2863: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2864: {
2865: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2866: }
2867:
1.211 djm 2868: #ifdef WITH_OPENSSL
1.201 markus 2869: int
2870: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2871: {
2872: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2873: }
2874:
2875:
2876: int
2877: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2878: {
2879: return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2880: }
1.211 djm 2881: #endif /* WITH_OPENSSL */
1.201 markus 2882:
2883: int
2884: sshpkt_get_end(struct ssh *ssh)
2885: {
2886: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2887: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2888: return 0;
2889: }
2890:
2891: const u_char *
2892: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2893: {
2894: if (lenp != NULL)
2895: *lenp = sshbuf_len(ssh->state->incoming_packet);
2896: return sshbuf_ptr(ssh->state->incoming_packet);
2897: }
2898:
2899: /* start a new packet */
2900:
2901: int
2902: sshpkt_start(struct ssh *ssh, u_char type)
2903: {
2904: u_char buf[9];
2905: int len;
2906:
2907: DBG(debug("packet_start[%d]", type));
2908: len = compat20 ? 6 : 9;
2909: memset(buf, 0, len - 1);
2910: buf[len - 1] = type;
2911: sshbuf_reset(ssh->state->outgoing_packet);
2912: return sshbuf_put(ssh->state->outgoing_packet, buf, len);
2913: }
2914:
1.242 markus 2915: static int
2916: ssh_packet_send_mux(struct ssh *ssh)
2917: {
2918: struct session_state *state = ssh->state;
2919: u_char type, *cp;
2920: size_t len;
2921: int r;
2922:
2923: if (ssh->kex)
2924: return SSH_ERR_INTERNAL_ERROR;
2925: len = sshbuf_len(state->outgoing_packet);
2926: if (len < 6)
2927: return SSH_ERR_INTERNAL_ERROR;
2928: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2929: type = cp[5];
2930: if (ssh_packet_log_type(type))
2931: debug3("%s: type %u", __func__, type);
2932: /* drop everything, but the connection protocol */
2933: if (type >= SSH2_MSG_CONNECTION_MIN &&
2934: type <= SSH2_MSG_CONNECTION_MAX) {
2935: POKE_U32(cp, len - 4);
2936: if ((r = sshbuf_putb(state->output,
2937: state->outgoing_packet)) != 0)
2938: return r;
2939: /* sshbuf_dump(state->output, stderr); */
2940: }
2941: sshbuf_reset(state->outgoing_packet);
2942: return 0;
2943: }
2944:
1.201 markus 2945: /* send it */
2946:
2947: int
2948: sshpkt_send(struct ssh *ssh)
2949: {
1.242 markus 2950: if (ssh->state && ssh->state->mux)
2951: return ssh_packet_send_mux(ssh);
1.201 markus 2952: if (compat20)
2953: return ssh_packet_send2(ssh);
2954: else
2955: return ssh_packet_send1(ssh);
2956: }
2957:
2958: int
2959: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2960: {
2961: char buf[1024];
2962: va_list args;
2963: int r;
2964:
2965: va_start(args, fmt);
2966: vsnprintf(buf, sizeof(buf), fmt, args);
2967: va_end(args);
2968:
2969: if (compat20) {
2970: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2971: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2972: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2973: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2974: (r = sshpkt_send(ssh)) != 0)
2975: return r;
2976: } else {
2977: if ((r = sshpkt_start(ssh, SSH_MSG_DISCONNECT)) != 0 ||
2978: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2979: (r = sshpkt_send(ssh)) != 0)
2980: return r;
1.166 andreas 2981: }
1.201 markus 2982: return 0;
2983: }
2984:
2985: /* roundup current message to pad bytes */
2986: int
2987: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2988: {
2989: ssh->state->extra_pad = pad;
2990: return 0;
1.1 deraadt 2991: }
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