Annotation of src/usr.bin/ssh/packet.c, Revision 1.275
1.275 ! sf 1: /* $OpenBSD: packet.c,v 1.274 2018/07/06 09:06:14 sf Exp $ */
1.1 deraadt 2: /*
1.15 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.35 deraadt 6: * This file contains code implementing the packet protocol and communication
7: * with the other side. This same code is used both on client and server side.
1.29 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
1.29 markus 14: *
1.25 markus 15: *
16: * SSH2 packet format added by Markus Friedl.
1.69 markus 17: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.25 markus 18: *
1.35 deraadt 19: * Redistribution and use in source and binary forms, with or without
20: * modification, are permitted provided that the following conditions
21: * are met:
22: * 1. Redistributions of source code must retain the above copyright
23: * notice, this list of conditions and the following disclaimer.
24: * 2. Redistributions in binary form must reproduce the above copyright
25: * notice, this list of conditions and the following disclaimer in the
26: * documentation and/or other materials provided with the distribution.
27: *
28: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.15 deraadt 38: */
1.1 deraadt 39:
1.142 deraadt 40: #include <sys/types.h>
1.105 markus 41: #include <sys/queue.h>
1.132 stevesk 42: #include <sys/socket.h>
1.138 stevesk 43: #include <sys/time.h>
1.132 stevesk 44: #include <netinet/in.h>
1.121 stevesk 45: #include <netinet/ip.h>
1.134 stevesk 46:
1.135 stevesk 47: #include <errno.h>
1.230 djm 48: #include <netdb.h>
1.134 stevesk 49: #include <stdarg.h>
1.141 stevesk 50: #include <stdio.h>
1.140 stevesk 51: #include <stdlib.h>
1.137 stevesk 52: #include <string.h>
1.136 stevesk 53: #include <unistd.h>
1.203 deraadt 54: #include <limits.h>
1.142 deraadt 55: #include <signal.h>
1.184 dtucker 56: #include <time.h>
1.1 deraadt 57:
1.201 markus 58: #include <zlib.h>
59:
60: #include "buffer.h" /* typedefs XXX */
61: #include "key.h" /* typedefs XXX */
62:
1.1 deraadt 63: #include "xmalloc.h"
64: #include "crc32.h"
1.25 markus 65: #include "compat.h"
66: #include "ssh2.h"
1.37 markus 67: #include "cipher.h"
1.201 markus 68: #include "sshkey.h"
1.25 markus 69: #include "kex.h"
1.200 markus 70: #include "digest.h"
1.50 markus 71: #include "mac.h"
1.46 markus 72: #include "log.h"
73: #include "canohost.h"
1.87 stevesk 74: #include "misc.h"
1.198 millert 75: #include "channels.h"
1.95 markus 76: #include "ssh.h"
1.201 markus 77: #include "packet.h"
1.197 djm 78: #include "ssherr.h"
1.201 markus 79: #include "sshbuf.h"
1.25 markus 80:
81: #ifdef PACKET_DEBUG
82: #define DBG(x) x
83: #else
84: #define DBG(x)
85: #endif
86:
1.159 markus 87: #define PACKET_MAX_SIZE (256 * 1024)
88:
1.161 andreas 89: struct packet_state {
90: u_int32_t seqnr;
91: u_int32_t packets;
92: u_int64_t blocks;
93: u_int64_t bytes;
94: };
95:
96: struct packet {
97: TAILQ_ENTRY(packet) next;
98: u_char type;
1.201 markus 99: struct sshbuf *payload;
1.161 andreas 100: };
101:
102: struct session_state {
103: /*
104: * This variable contains the file descriptors used for
105: * communicating with the other side. connection_in is used for
106: * reading; connection_out for writing. These can be the same
107: * descriptor, in which case it is assumed to be a socket.
108: */
109: int connection_in;
110: int connection_out;
111:
112: /* Protocol flags for the remote side. */
113: u_int remote_protocol_flags;
1.1 deraadt 114:
1.161 andreas 115: /* Encryption context for receiving data. Only used for decryption. */
1.235 djm 116: struct sshcipher_ctx *receive_context;
1.1 deraadt 117:
1.161 andreas 118: /* Encryption context for sending data. Only used for encryption. */
1.235 djm 119: struct sshcipher_ctx *send_context;
1.14 markus 120:
1.161 andreas 121: /* Buffer for raw input data from the socket. */
1.201 markus 122: struct sshbuf *input;
1.1 deraadt 123:
1.161 andreas 124: /* Buffer for raw output data going to the socket. */
1.201 markus 125: struct sshbuf *output;
1.1 deraadt 126:
1.161 andreas 127: /* Buffer for the partial outgoing packet being constructed. */
1.201 markus 128: struct sshbuf *outgoing_packet;
1.1 deraadt 129:
1.161 andreas 130: /* Buffer for the incoming packet currently being processed. */
1.201 markus 131: struct sshbuf *incoming_packet;
1.1 deraadt 132:
1.161 andreas 133: /* Scratch buffer for packet compression/decompression. */
1.201 markus 134: struct sshbuf *compression_buffer;
135:
136: /* Incoming/outgoing compression dictionaries */
137: z_stream compression_in_stream;
138: z_stream compression_out_stream;
139: int compression_in_started;
140: int compression_out_started;
141: int compression_in_failures;
142: int compression_out_failures;
1.1 deraadt 143:
1.161 andreas 144: /* default maximum packet size */
145: u_int max_packet_size;
1.1 deraadt 146:
1.161 andreas 147: /* Flag indicating whether this module has been initialized. */
148: int initialized;
1.12 markus 149:
1.161 andreas 150: /* Set to true if the connection is interactive. */
151: int interactive_mode;
1.1 deraadt 152:
1.161 andreas 153: /* Set to true if we are the server side. */
154: int server_side;
1.1 deraadt 155:
1.161 andreas 156: /* Set to true if we are authenticated. */
157: int after_authentication;
1.118 markus 158:
1.161 andreas 159: int keep_alive_timeouts;
1.118 markus 160:
1.161 andreas 161: /* The maximum time that we will wait to send or receive a packet */
162: int packet_timeout_ms;
1.151 dtucker 163:
1.161 andreas 164: /* Session key information for Encryption and MAC */
1.201 markus 165: struct newkeys *newkeys[MODE_MAX];
1.161 andreas 166: struct packet_state p_read, p_send;
1.154 dtucker 167:
1.184 dtucker 168: /* Volume-based rekeying */
1.224 dtucker 169: u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
1.105 markus 170:
1.184 dtucker 171: /* Time-based rekeying */
1.208 markus 172: u_int32_t rekey_interval; /* how often in seconds */
1.184 dtucker 173: time_t rekey_time; /* time of last rekeying */
174:
1.161 andreas 175: /* roundup current message to extra_pad bytes */
176: u_char extra_pad;
1.95 markus 177:
1.161 andreas 178: /* XXX discard incoming data after MAC error */
179: u_int packet_discard;
1.234 markus 180: size_t packet_discard_mac_already;
1.201 markus 181: struct sshmac *packet_discard_mac;
1.71 markus 182:
1.161 andreas 183: /* Used in packet_read_poll2() */
184: u_int packlen;
1.159 markus 185:
1.165 andreas 186: /* Used in packet_send2 */
187: int rekeying;
188:
1.242 markus 189: /* Used in ssh_packet_send_mux() */
190: int mux;
191:
1.165 andreas 192: /* Used in packet_set_interactive */
193: int set_interactive_called;
194:
195: /* Used in packet_set_maxsize */
196: int set_maxsize_called;
197:
1.201 markus 198: /* One-off warning about weak ciphers */
199: int cipher_warning_done;
200:
1.243 djm 201: /* Hook for fuzzing inbound packets */
202: ssh_packet_hook_fn *hook_in;
203: void *hook_in_ctx;
204:
1.161 andreas 205: TAILQ_HEAD(, packet) outgoing;
1.105 markus 206: };
1.161 andreas 207:
1.201 markus 208: struct ssh *
209: ssh_alloc_session_state(void)
1.161 andreas 210: {
1.201 markus 211: struct ssh *ssh = NULL;
212: struct session_state *state = NULL;
1.161 andreas 213:
1.201 markus 214: if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
215: (state = calloc(1, sizeof(*state))) == NULL ||
216: (state->input = sshbuf_new()) == NULL ||
217: (state->output = sshbuf_new()) == NULL ||
218: (state->outgoing_packet = sshbuf_new()) == NULL ||
219: (state->incoming_packet = sshbuf_new()) == NULL)
220: goto fail;
221: TAILQ_INIT(&state->outgoing);
1.202 markus 222: TAILQ_INIT(&ssh->private_keys);
223: TAILQ_INIT(&ssh->public_keys);
1.201 markus 224: state->connection_in = -1;
225: state->connection_out = -1;
226: state->max_packet_size = 32768;
227: state->packet_timeout_ms = -1;
228: state->p_send.packets = state->p_read.packets = 0;
229: state->initialized = 1;
230: /*
231: * ssh_packet_send2() needs to queue packets until
232: * we've done the initial key exchange.
233: */
234: state->rekeying = 1;
235: ssh->state = state;
236: return ssh;
237: fail:
238: if (state) {
239: sshbuf_free(state->input);
240: sshbuf_free(state->output);
241: sshbuf_free(state->incoming_packet);
242: sshbuf_free(state->outgoing_packet);
243: free(state);
244: }
245: free(ssh);
246: return NULL;
1.161 andreas 247: }
1.105 markus 248:
1.243 djm 249: void
250: ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
251: {
252: ssh->state->hook_in = hook;
253: ssh->state->hook_in_ctx = ctx;
254: }
255:
1.228 djm 256: /* Returns nonzero if rekeying is in progress */
257: int
258: ssh_packet_is_rekeying(struct ssh *ssh)
259: {
1.249 djm 260: return ssh->state->rekeying ||
261: (ssh->kex != NULL && ssh->kex->done == 0);
1.228 djm 262: }
263:
1.16 markus 264: /*
1.253 naddy 265: * Sets the descriptors used for communication.
1.16 markus 266: */
1.201 markus 267: struct ssh *
268: ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
1.1 deraadt 269: {
1.201 markus 270: struct session_state *state;
271: const struct sshcipher *none = cipher_by_name("none");
1.197 djm 272: int r;
1.97 deraadt 273:
1.205 djm 274: if (none == NULL) {
275: error("%s: cannot load cipher 'none'", __func__);
276: return NULL;
277: }
1.201 markus 278: if (ssh == NULL)
279: ssh = ssh_alloc_session_state();
1.205 djm 280: if (ssh == NULL) {
281: error("%s: cound not allocate state", __func__);
282: return NULL;
283: }
1.201 markus 284: state = ssh->state;
285: state->connection_in = fd_in;
286: state->connection_out = fd_out;
287: if ((r = cipher_init(&state->send_context, none,
1.197 djm 288: (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
1.201 markus 289: (r = cipher_init(&state->receive_context, none,
1.205 djm 290: (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
291: error("%s: cipher_init failed: %s", __func__, ssh_err(r));
1.230 djm 292: free(ssh); /* XXX need ssh_free_session_state? */
1.205 djm 293: return NULL;
294: }
1.201 markus 295: state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
1.207 djm 296: /*
297: * Cache the IP address of the remote connection for use in error
298: * messages that might be generated after the connection has closed.
299: */
300: (void)ssh_remote_ipaddr(ssh);
1.201 markus 301: return ssh;
1.1 deraadt 302: }
303:
1.154 dtucker 304: void
1.201 markus 305: ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
1.154 dtucker 306: {
1.201 markus 307: struct session_state *state = ssh->state;
308:
1.174 djm 309: if (timeout <= 0 || count <= 0) {
1.201 markus 310: state->packet_timeout_ms = -1;
1.154 dtucker 311: return;
312: }
313: if ((INT_MAX / 1000) / count < timeout)
1.201 markus 314: state->packet_timeout_ms = INT_MAX;
1.154 dtucker 315: else
1.201 markus 316: state->packet_timeout_ms = timeout * count * 1000;
1.154 dtucker 317: }
318:
1.242 markus 319: void
320: ssh_packet_set_mux(struct ssh *ssh)
321: {
322: ssh->state->mux = 1;
323: ssh->state->rekeying = 0;
324: }
325:
326: int
327: ssh_packet_get_mux(struct ssh *ssh)
328: {
329: return ssh->state->mux;
330: }
331:
1.201 markus 332: int
1.245 djm 333: ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
334: {
335: va_list args;
336: int r;
337:
338: free(ssh->log_preamble);
339: if (fmt == NULL)
340: ssh->log_preamble = NULL;
341: else {
342: va_start(args, fmt);
343: r = vasprintf(&ssh->log_preamble, fmt, args);
344: va_end(args);
345: if (r < 0 || ssh->log_preamble == NULL)
346: return SSH_ERR_ALLOC_FAIL;
347: }
348: return 0;
349: }
350:
351: int
1.201 markus 352: ssh_packet_stop_discard(struct ssh *ssh)
1.159 markus 353: {
1.201 markus 354: struct session_state *state = ssh->state;
355: int r;
356:
357: if (state->packet_discard_mac) {
1.159 markus 358: char buf[1024];
1.234 markus 359: size_t dlen = PACKET_MAX_SIZE;
1.201 markus 360:
1.234 markus 361: if (dlen > state->packet_discard_mac_already)
362: dlen -= state->packet_discard_mac_already;
1.159 markus 363: memset(buf, 'a', sizeof(buf));
1.234 markus 364: while (sshbuf_len(state->incoming_packet) < dlen)
1.201 markus 365: if ((r = sshbuf_put(state->incoming_packet, buf,
366: sizeof(buf))) != 0)
367: return r;
368: (void) mac_compute(state->packet_discard_mac,
369: state->p_read.seqnr,
1.234 markus 370: sshbuf_ptr(state->incoming_packet), dlen,
1.201 markus 371: NULL, 0);
1.159 markus 372: }
1.220 djm 373: logit("Finished discarding for %.200s port %d",
374: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.201 markus 375: return SSH_ERR_MAC_INVALID;
1.159 markus 376: }
377:
1.201 markus 378: static int
379: ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
1.234 markus 380: struct sshmac *mac, size_t mac_already, u_int discard)
1.159 markus 381: {
1.201 markus 382: struct session_state *state = ssh->state;
383: int r;
384:
385: if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
386: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
387: return r;
388: return SSH_ERR_MAC_INVALID;
389: }
1.234 markus 390: /*
391: * Record number of bytes over which the mac has already
392: * been computed in order to minimize timing attacks.
393: */
394: if (mac && mac->enabled) {
1.201 markus 395: state->packet_discard_mac = mac;
1.234 markus 396: state->packet_discard_mac_already = mac_already;
397: }
398: if (sshbuf_len(state->input) >= discard)
399: return ssh_packet_stop_discard(ssh);
1.201 markus 400: state->packet_discard = discard - sshbuf_len(state->input);
401: return 0;
1.159 markus 402: }
403:
1.19 markus 404: /* Returns 1 if remote host is connected via socket, 0 if not. */
405:
406: int
1.201 markus 407: ssh_packet_connection_is_on_socket(struct ssh *ssh)
1.19 markus 408: {
1.271 djm 409: struct session_state *state;
1.19 markus 410: struct sockaddr_storage from, to;
411: socklen_t fromlen, tolen;
412:
1.271 djm 413: if (ssh == NULL || ssh->state == NULL)
414: return 0;
415:
416: state = ssh->state;
1.230 djm 417: if (state->connection_in == -1 || state->connection_out == -1)
418: return 0;
1.19 markus 419: /* filedescriptors in and out are the same, so it's a socket */
1.201 markus 420: if (state->connection_in == state->connection_out)
1.19 markus 421: return 1;
422: fromlen = sizeof(from);
423: memset(&from, 0, sizeof(from));
1.201 markus 424: if (getpeername(state->connection_in, (struct sockaddr *)&from,
1.161 andreas 425: &fromlen) < 0)
1.19 markus 426: return 0;
427: tolen = sizeof(to);
428: memset(&to, 0, sizeof(to));
1.201 markus 429: if (getpeername(state->connection_out, (struct sockaddr *)&to,
1.161 andreas 430: &tolen) < 0)
1.19 markus 431: return 0;
432: if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
433: return 0;
434: if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
435: return 0;
436: return 1;
437: }
438:
1.91 markus 439: void
1.201 markus 440: ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
1.91 markus 441: {
1.201 markus 442: if (ibytes)
443: *ibytes = ssh->state->p_read.bytes;
444: if (obytes)
445: *obytes = ssh->state->p_send.bytes;
1.91 markus 446: }
1.125 deraadt 447:
1.91 markus 448: int
1.201 markus 449: ssh_packet_connection_af(struct ssh *ssh)
1.19 markus 450: {
451: struct sockaddr_storage to;
1.21 deraadt 452: socklen_t tolen = sizeof(to);
1.19 markus 453:
454: memset(&to, 0, sizeof(to));
1.201 markus 455: if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
1.161 andreas 456: &tolen) < 0)
1.19 markus 457: return 0;
1.173 djm 458: return to.ss_family;
1.19 markus 459: }
460:
1.1 deraadt 461: /* Sets the connection into non-blocking mode. */
462:
1.2 provos 463: void
1.201 markus 464: ssh_packet_set_nonblocking(struct ssh *ssh)
1.1 deraadt 465: {
1.14 markus 466: /* Set the socket into non-blocking mode. */
1.201 markus 467: set_nonblock(ssh->state->connection_in);
1.14 markus 468:
1.201 markus 469: if (ssh->state->connection_out != ssh->state->connection_in)
470: set_nonblock(ssh->state->connection_out);
1.1 deraadt 471: }
472:
473: /* Returns the socket used for reading. */
474:
1.2 provos 475: int
1.201 markus 476: ssh_packet_get_connection_in(struct ssh *ssh)
1.1 deraadt 477: {
1.201 markus 478: return ssh->state->connection_in;
1.1 deraadt 479: }
480:
481: /* Returns the descriptor used for writing. */
482:
1.2 provos 483: int
1.201 markus 484: ssh_packet_get_connection_out(struct ssh *ssh)
1.1 deraadt 485: {
1.201 markus 486: return ssh->state->connection_out;
487: }
488:
489: /*
490: * Returns the IP-address of the remote host as a string. The returned
491: * string must not be freed.
492: */
493:
494: const char *
495: ssh_remote_ipaddr(struct ssh *ssh)
496: {
1.271 djm 497: int sock;
1.220 djm 498:
1.201 markus 499: /* Check whether we have cached the ipaddr. */
1.220 djm 500: if (ssh->remote_ipaddr == NULL) {
501: if (ssh_packet_connection_is_on_socket(ssh)) {
1.271 djm 502: sock = ssh->state->connection_in;
1.220 djm 503: ssh->remote_ipaddr = get_peer_ipaddr(sock);
1.230 djm 504: ssh->remote_port = get_peer_port(sock);
505: ssh->local_ipaddr = get_local_ipaddr(sock);
506: ssh->local_port = get_local_port(sock);
1.220 djm 507: } else {
508: ssh->remote_ipaddr = strdup("UNKNOWN");
1.230 djm 509: ssh->remote_port = 65535;
510: ssh->local_ipaddr = strdup("UNKNOWN");
511: ssh->local_port = 65535;
1.220 djm 512: }
513: }
1.201 markus 514: return ssh->remote_ipaddr;
1.1 deraadt 515: }
516:
1.220 djm 517: /* Returns the port number of the remote host. */
518:
519: int
520: ssh_remote_port(struct ssh *ssh)
521: {
522: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
523: return ssh->remote_port;
1.230 djm 524: }
525:
526: /*
527: * Returns the IP-address of the local host as a string. The returned
528: * string must not be freed.
529: */
530:
531: const char *
532: ssh_local_ipaddr(struct ssh *ssh)
533: {
534: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
535: return ssh->local_ipaddr;
536: }
537:
538: /* Returns the port number of the local host. */
539:
540: int
541: ssh_local_port(struct ssh *ssh)
542: {
543: (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
544: return ssh->local_port;
1.266 djm 545: }
546:
547: /* Returns the routing domain of the input socket, or NULL if unavailable */
548: const char *
549: ssh_packet_rdomain_in(struct ssh *ssh)
550: {
551: if (ssh->rdomain_in != NULL)
552: return ssh->rdomain_in;
553: if (!ssh_packet_connection_is_on_socket(ssh))
554: return NULL;
555: ssh->rdomain_in = get_rdomain(ssh->state->connection_in);
556: return ssh->rdomain_in;
1.220 djm 557: }
558:
1.1 deraadt 559: /* Closes the connection and clears and frees internal data structures. */
560:
1.257 markus 561: static void
562: ssh_packet_close_internal(struct ssh *ssh, int do_close)
1.1 deraadt 563: {
1.201 markus 564: struct session_state *state = ssh->state;
565: u_int mode;
566:
567: if (!state->initialized)
1.14 markus 568: return;
1.201 markus 569: state->initialized = 0;
1.257 markus 570: if (do_close) {
571: if (state->connection_in == state->connection_out) {
572: close(state->connection_out);
573: } else {
574: close(state->connection_in);
575: close(state->connection_out);
576: }
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);
1.257 markus 582: for (mode = 0; mode < MODE_MAX; mode++) {
583: kex_free_newkeys(state->newkeys[mode]); /* current keys */
584: state->newkeys[mode] = NULL;
585: ssh_clear_newkeys(ssh, mode); /* next keys */
586: }
587: /* comression state is in shared mem, so we can only release it once */
588: if (do_close && state->compression_buffer) {
1.201 markus 589: sshbuf_free(state->compression_buffer);
590: if (state->compression_out_started) {
591: z_streamp stream = &state->compression_out_stream;
592: debug("compress outgoing: "
593: "raw data %llu, compressed %llu, factor %.2f",
594: (unsigned long long)stream->total_in,
595: (unsigned long long)stream->total_out,
596: stream->total_in == 0 ? 0.0 :
597: (double) stream->total_out / stream->total_in);
598: if (state->compression_out_failures == 0)
599: deflateEnd(stream);
600: }
601: if (state->compression_in_started) {
1.260 dtucker 602: z_streamp stream = &state->compression_in_stream;
1.201 markus 603: debug("compress incoming: "
604: "raw data %llu, compressed %llu, factor %.2f",
605: (unsigned long long)stream->total_out,
606: (unsigned long long)stream->total_in,
607: stream->total_out == 0 ? 0.0 :
608: (double) stream->total_in / stream->total_out);
609: if (state->compression_in_failures == 0)
610: inflateEnd(stream);
611: }
1.14 markus 612: }
1.235 djm 613: cipher_free(state->send_context);
614: cipher_free(state->receive_context);
615: state->send_context = state->receive_context = NULL;
1.257 markus 616: if (do_close) {
617: free(ssh->remote_ipaddr);
618: ssh->remote_ipaddr = NULL;
619: free(ssh->state);
620: ssh->state = NULL;
621: }
622: }
623:
624: void
625: ssh_packet_close(struct ssh *ssh)
626: {
627: ssh_packet_close_internal(ssh, 1);
628: }
629:
630: void
631: ssh_packet_clear_keys(struct ssh *ssh)
632: {
633: ssh_packet_close_internal(ssh, 0);
1.1 deraadt 634: }
635:
636: /* Sets remote side protocol flags. */
637:
1.2 provos 638: void
1.201 markus 639: ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
1.1 deraadt 640: {
1.201 markus 641: ssh->state->remote_protocol_flags = protocol_flags;
1.1 deraadt 642: }
643:
644: /* Returns the remote protocol flags set earlier by the above function. */
645:
1.40 markus 646: u_int
1.201 markus 647: ssh_packet_get_protocol_flags(struct ssh *ssh)
1.1 deraadt 648: {
1.201 markus 649: return ssh->state->remote_protocol_flags;
1.1 deraadt 650: }
651:
1.16 markus 652: /*
653: * Starts packet compression from the next packet on in both directions.
654: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
655: */
1.1 deraadt 656:
1.201 markus 657: static int
658: ssh_packet_init_compression(struct ssh *ssh)
1.60 markus 659: {
1.201 markus 660: if (!ssh->state->compression_buffer &&
661: ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
662: return SSH_ERR_ALLOC_FAIL;
663: return 0;
1.60 markus 664: }
665:
1.201 markus 666: static int
667: start_compression_out(struct ssh *ssh, int level)
1.1 deraadt 668: {
1.201 markus 669: if (level < 1 || level > 9)
670: return SSH_ERR_INVALID_ARGUMENT;
671: debug("Enabling compression at level %d.", level);
672: if (ssh->state->compression_out_started == 1)
673: deflateEnd(&ssh->state->compression_out_stream);
674: switch (deflateInit(&ssh->state->compression_out_stream, level)) {
675: case Z_OK:
676: ssh->state->compression_out_started = 1;
677: break;
678: case Z_MEM_ERROR:
679: return SSH_ERR_ALLOC_FAIL;
680: default:
681: return SSH_ERR_INTERNAL_ERROR;
682: }
683: return 0;
1.1 deraadt 684: }
685:
1.201 markus 686: static int
687: start_compression_in(struct ssh *ssh)
688: {
689: if (ssh->state->compression_in_started == 1)
690: inflateEnd(&ssh->state->compression_in_stream);
691: switch (inflateInit(&ssh->state->compression_in_stream)) {
692: case Z_OK:
693: ssh->state->compression_in_started = 1;
694: break;
695: case Z_MEM_ERROR:
696: return SSH_ERR_ALLOC_FAIL;
697: default:
698: return SSH_ERR_INTERNAL_ERROR;
699: }
700: return 0;
1.95 markus 701: }
702:
1.201 markus 703: /* XXX remove need for separate compression buffer */
704: static int
705: compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.95 markus 706: {
1.201 markus 707: u_char buf[4096];
708: int r, status;
709:
710: if (ssh->state->compression_out_started != 1)
711: return SSH_ERR_INTERNAL_ERROR;
712:
713: /* This case is not handled below. */
714: if (sshbuf_len(in) == 0)
715: return 0;
716:
717: /* Input is the contents of the input buffer. */
718: if ((ssh->state->compression_out_stream.next_in =
719: sshbuf_mutable_ptr(in)) == NULL)
720: return SSH_ERR_INTERNAL_ERROR;
721: ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
722:
723: /* Loop compressing until deflate() returns with avail_out != 0. */
724: do {
725: /* Set up fixed-size output buffer. */
726: ssh->state->compression_out_stream.next_out = buf;
727: ssh->state->compression_out_stream.avail_out = sizeof(buf);
728:
729: /* Compress as much data into the buffer as possible. */
730: status = deflate(&ssh->state->compression_out_stream,
731: Z_PARTIAL_FLUSH);
732: switch (status) {
733: case Z_MEM_ERROR:
734: return SSH_ERR_ALLOC_FAIL;
735: case Z_OK:
736: /* Append compressed data to output_buffer. */
737: if ((r = sshbuf_put(out, buf, sizeof(buf) -
738: ssh->state->compression_out_stream.avail_out)) != 0)
739: return r;
740: break;
741: case Z_STREAM_ERROR:
742: default:
743: ssh->state->compression_out_failures++;
744: return SSH_ERR_INVALID_FORMAT;
745: }
746: } while (ssh->state->compression_out_stream.avail_out == 0);
747: return 0;
1.1 deraadt 748: }
749:
1.201 markus 750: static int
751: uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
1.1 deraadt 752: {
1.201 markus 753: u_char buf[4096];
754: int r, status;
1.1 deraadt 755:
1.201 markus 756: if (ssh->state->compression_in_started != 1)
757: return SSH_ERR_INTERNAL_ERROR;
1.25 markus 758:
1.201 markus 759: if ((ssh->state->compression_in_stream.next_in =
760: sshbuf_mutable_ptr(in)) == NULL)
761: return SSH_ERR_INTERNAL_ERROR;
762: ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
1.97 deraadt 763:
1.201 markus 764: for (;;) {
765: /* Set up fixed-size output buffer. */
766: ssh->state->compression_in_stream.next_out = buf;
767: ssh->state->compression_in_stream.avail_out = sizeof(buf);
768:
769: status = inflate(&ssh->state->compression_in_stream,
770: Z_PARTIAL_FLUSH);
771: switch (status) {
772: case Z_OK:
773: if ((r = sshbuf_put(out, buf, sizeof(buf) -
774: ssh->state->compression_in_stream.avail_out)) != 0)
775: return r;
776: break;
777: case Z_BUF_ERROR:
778: /*
779: * Comments in zlib.h say that we should keep calling
780: * inflate() until we get an error. This appears to
781: * be the error that we get.
782: */
783: return 0;
784: case Z_DATA_ERROR:
785: return SSH_ERR_INVALID_FORMAT;
786: case Z_MEM_ERROR:
787: return SSH_ERR_ALLOC_FAIL;
788: case Z_STREAM_ERROR:
789: default:
790: ssh->state->compression_in_failures++;
791: return SSH_ERR_INTERNAL_ERROR;
792: }
793: }
794: /* NOTREACHED */
1.170 djm 795: }
796:
1.257 markus 797: void
798: ssh_clear_newkeys(struct ssh *ssh, int mode)
799: {
1.259 djm 800: if (ssh->kex && ssh->kex->newkeys[mode]) {
1.257 markus 801: kex_free_newkeys(ssh->kex->newkeys[mode]);
802: ssh->kex->newkeys[mode] = NULL;
803: }
804: }
805:
1.201 markus 806: int
807: ssh_set_newkeys(struct ssh *ssh, int mode)
1.57 markus 808: {
1.201 markus 809: struct session_state *state = ssh->state;
810: struct sshenc *enc;
811: struct sshmac *mac;
812: struct sshcomp *comp;
1.235 djm 813: struct sshcipher_ctx **ccp;
1.236 markus 814: struct packet_state *ps;
1.105 markus 815: u_int64_t *max_blocks;
1.259 djm 816: const char *wmsg;
1.197 djm 817: int r, crypt_type;
1.57 markus 818:
1.100 markus 819: debug2("set_newkeys: mode %d", mode);
1.57 markus 820:
1.88 markus 821: if (mode == MODE_OUT) {
1.235 djm 822: ccp = &state->send_context;
1.115 avsm 823: crypt_type = CIPHER_ENCRYPT;
1.236 markus 824: ps = &state->p_send;
1.201 markus 825: max_blocks = &state->max_blocks_out;
1.88 markus 826: } else {
1.235 djm 827: ccp = &state->receive_context;
1.115 avsm 828: crypt_type = CIPHER_DECRYPT;
1.236 markus 829: ps = &state->p_read;
1.201 markus 830: max_blocks = &state->max_blocks_in;
1.88 markus 831: }
1.201 markus 832: if (state->newkeys[mode] != NULL) {
1.257 markus 833: debug("set_newkeys: rekeying, input %llu bytes %llu blocks, "
834: "output %llu bytes %llu blocks",
835: (unsigned long long)state->p_read.bytes,
836: (unsigned long long)state->p_read.blocks,
837: (unsigned long long)state->p_send.bytes,
838: (unsigned long long)state->p_send.blocks);
1.235 djm 839: cipher_free(*ccp);
840: *ccp = NULL;
1.257 markus 841: kex_free_newkeys(state->newkeys[mode]);
842: state->newkeys[mode] = NULL;
1.57 markus 843: }
1.236 markus 844: /* note that both bytes and the seqnr are not reset */
845: ps->packets = ps->blocks = 0;
1.201 markus 846: /* move newkeys from kex to state */
847: if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
848: return SSH_ERR_INTERNAL_ERROR;
849: ssh->kex->newkeys[mode] = NULL;
850: enc = &state->newkeys[mode]->enc;
851: mac = &state->newkeys[mode]->mac;
852: comp = &state->newkeys[mode]->comp;
853: if (cipher_authlen(enc->cipher) == 0) {
854: if ((r = mac_init(mac)) != 0)
855: return r;
856: }
857: mac->enabled = 1;
1.57 markus 858: DBG(debug("cipher_init_context: %d", mode));
1.235 djm 859: if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
1.197 djm 860: enc->iv, enc->iv_len, crypt_type)) != 0)
1.201 markus 861: return r;
862: if (!state->cipher_warning_done &&
1.235 djm 863: (wmsg = cipher_warning_message(*ccp)) != NULL) {
1.201 markus 864: error("Warning: %s", wmsg);
865: state->cipher_warning_done = 1;
866: }
1.91 markus 867: /* Deleting the keys does not gain extra security */
1.192 djm 868: /* explicit_bzero(enc->iv, enc->block_size);
869: explicit_bzero(enc->key, enc->key_len);
870: explicit_bzero(mac->key, mac->key_len); */
1.275 ! sf 871: if ((comp->type == COMP_ZLIB ||
! 872: (comp->type == COMP_DELAYED &&
! 873: state->after_authentication)) && comp->enabled == 0) {
1.201 markus 874: if ((r = ssh_packet_init_compression(ssh)) < 0)
875: return r;
876: if (mode == MODE_OUT) {
877: if ((r = start_compression_out(ssh, 6)) != 0)
878: return r;
879: } else {
880: if ((r = start_compression_in(ssh)) != 0)
881: return r;
882: }
1.57 markus 883: comp->enabled = 1;
884: }
1.109 markus 885: /*
886: * The 2^(blocksize*2) limit is too expensive for 3DES,
1.254 djm 887: * so enforce a 1GB limit for small blocksizes.
1.261 dtucker 888: * See RFC4344 section 3.2.
1.109 markus 889: */
890: if (enc->block_size >= 16)
891: *max_blocks = (u_int64_t)1 << (enc->block_size*2);
892: else
893: *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1.201 markus 894: if (state->rekey_limit)
1.237 deraadt 895: *max_blocks = MINIMUM(*max_blocks,
1.201 markus 896: state->rekey_limit / enc->block_size);
1.227 djm 897: debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1.201 markus 898: return 0;
1.57 markus 899: }
900:
1.228 djm 901: #define MAX_PACKETS (1U<<31)
902: static int
903: ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
904: {
905: struct session_state *state = ssh->state;
906: u_int32_t out_blocks;
907:
908: /* XXX client can't cope with rekeying pre-auth */
909: if (!state->after_authentication)
910: return 0;
911:
912: /* Haven't keyed yet or KEX in progress. */
913: if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
914: return 0;
915:
916: /* Peer can't rekey */
917: if (ssh->compat & SSH_BUG_NOREKEY)
918: return 0;
919:
920: /*
921: * Permit one packet in or out per rekey - this allows us to
922: * make progress when rekey limits are very small.
923: */
924: if (state->p_send.packets == 0 && state->p_read.packets == 0)
925: return 0;
926:
927: /* Time-based rekeying */
928: if (state->rekey_interval != 0 &&
1.244 dtucker 929: (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1.228 djm 930: return 1;
931:
1.261 dtucker 932: /*
933: * Always rekey when MAX_PACKETS sent in either direction
934: * As per RFC4344 section 3.1 we do this after 2^31 packets.
935: */
1.228 djm 936: if (state->p_send.packets > MAX_PACKETS ||
937: state->p_read.packets > MAX_PACKETS)
938: return 1;
939:
940: /* Rekey after (cipher-specific) maxiumum blocks */
1.237 deraadt 941: out_blocks = ROUNDUP(outbound_packet_len,
1.228 djm 942: state->newkeys[MODE_OUT]->enc.block_size);
943: return (state->max_blocks_out &&
944: (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
945: (state->max_blocks_in &&
946: (state->p_read.blocks > state->max_blocks_in));
947: }
948:
1.16 markus 949: /*
1.118 markus 950: * Delayed compression for SSH2 is enabled after authentication:
1.143 dtucker 951: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1.118 markus 952: * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
953: */
1.201 markus 954: static int
955: ssh_packet_enable_delayed_compress(struct ssh *ssh)
1.118 markus 956: {
1.201 markus 957: struct session_state *state = ssh->state;
958: struct sshcomp *comp = NULL;
959: int r, mode;
1.118 markus 960:
961: /*
962: * Remember that we are past the authentication step, so rekeying
1.275 ! sf 963: * with COMP_DELAYED will turn on compression immediately.
1.118 markus 964: */
1.201 markus 965: state->after_authentication = 1;
1.118 markus 966: for (mode = 0; mode < MODE_MAX; mode++) {
1.145 markus 967: /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1.201 markus 968: if (state->newkeys[mode] == NULL)
1.145 markus 969: continue;
1.201 markus 970: comp = &state->newkeys[mode]->comp;
1.275 ! sf 971: if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1.201 markus 972: if ((r = ssh_packet_init_compression(ssh)) != 0)
973: return r;
974: if (mode == MODE_OUT) {
975: if ((r = start_compression_out(ssh, 6)) != 0)
976: return r;
977: } else {
978: if ((r = start_compression_in(ssh)) != 0)
979: return r;
980: }
1.118 markus 981: comp->enabled = 1;
982: }
983: }
1.201 markus 984: return 0;
1.118 markus 985: }
986:
1.226 djm 987: /* Used to mute debug logging for noisy packet types */
1.242 markus 988: int
1.226 djm 989: ssh_packet_log_type(u_char type)
990: {
991: switch (type) {
992: case SSH2_MSG_CHANNEL_DATA:
993: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
994: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
995: return 0;
996: default:
997: return 1;
998: }
999: }
1000:
1.118 markus 1001: /*
1.25 markus 1002: * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1003: */
1.201 markus 1004: int
1005: ssh_packet_send2_wrapped(struct ssh *ssh)
1.25 markus 1006: {
1.201 markus 1007: struct session_state *state = ssh->state;
1.200 markus 1008: u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1.233 djm 1009: u_char tmp, padlen, pad = 0;
1.201 markus 1010: u_int authlen = 0, aadlen = 0;
1011: u_int len;
1012: struct sshenc *enc = NULL;
1013: struct sshmac *mac = NULL;
1014: struct sshcomp *comp = NULL;
1015: int r, block_size;
1016:
1017: if (state->newkeys[MODE_OUT] != NULL) {
1018: enc = &state->newkeys[MODE_OUT]->enc;
1019: mac = &state->newkeys[MODE_OUT]->mac;
1020: comp = &state->newkeys[MODE_OUT]->comp;
1.180 markus 1021: /* disable mac for authenticated encryption */
1022: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1023: mac = NULL;
1.25 markus 1024: }
1.88 markus 1025: block_size = enc ? enc->block_size : 8;
1.180 markus 1026: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1027:
1.201 markus 1028: type = (sshbuf_ptr(state->outgoing_packet))[5];
1.226 djm 1029: if (ssh_packet_log_type(type))
1030: debug3("send packet: type %u", type);
1.25 markus 1031: #ifdef PACKET_DEBUG
1032: fprintf(stderr, "plain: ");
1.201 markus 1033: sshbuf_dump(state->outgoing_packet, stderr);
1.25 markus 1034: #endif
1035:
1036: if (comp && comp->enabled) {
1.201 markus 1037: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1038: /* skip header, compress only payload */
1.201 markus 1039: if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1040: goto out;
1041: sshbuf_reset(state->compression_buffer);
1042: if ((r = compress_buffer(ssh, state->outgoing_packet,
1043: state->compression_buffer)) != 0)
1044: goto out;
1045: sshbuf_reset(state->outgoing_packet);
1046: if ((r = sshbuf_put(state->outgoing_packet,
1047: "\0\0\0\0\0", 5)) != 0 ||
1048: (r = sshbuf_putb(state->outgoing_packet,
1049: state->compression_buffer)) != 0)
1050: goto out;
1051: DBG(debug("compression: raw %d compressed %zd", len,
1052: sshbuf_len(state->outgoing_packet)));
1.25 markus 1053: }
1054:
1055: /* sizeof (packet_len + pad_len + payload) */
1.201 markus 1056: len = sshbuf_len(state->outgoing_packet);
1.25 markus 1057:
1058: /*
1059: * calc size of padding, alloc space, get random data,
1060: * minimum padding is 4 bytes
1061: */
1.178 markus 1062: len -= aadlen; /* packet length is not encrypted for EtM modes */
1.25 markus 1063: padlen = block_size - (len % block_size);
1064: if (padlen < 4)
1065: padlen += block_size;
1.201 markus 1066: if (state->extra_pad) {
1.233 djm 1067: tmp = state->extra_pad;
1.201 markus 1068: state->extra_pad =
1.237 deraadt 1069: ROUNDUP(state->extra_pad, block_size);
1.233 djm 1070: /* check if roundup overflowed */
1071: if (state->extra_pad < tmp)
1072: return SSH_ERR_INVALID_ARGUMENT;
1073: tmp = (len + padlen) % state->extra_pad;
1074: /* Check whether pad calculation below will underflow */
1075: if (tmp > state->extra_pad)
1076: return SSH_ERR_INVALID_ARGUMENT;
1077: pad = state->extra_pad - tmp;
1.193 djm 1078: DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1.201 markus 1079: __func__, pad, len, padlen, state->extra_pad));
1.233 djm 1080: tmp = padlen;
1.71 markus 1081: padlen += pad;
1.233 djm 1082: /* Check whether padlen calculation overflowed */
1083: if (padlen < tmp)
1084: return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1.201 markus 1085: state->extra_pad = 0;
1.71 markus 1086: }
1.201 markus 1087: if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1088: goto out;
1.235 djm 1089: if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1.32 markus 1090: /* random padding */
1.201 markus 1091: arc4random_buf(cp, padlen);
1.32 markus 1092: } else {
1093: /* clear padding */
1.192 djm 1094: explicit_bzero(cp, padlen);
1.25 markus 1095: }
1.178 markus 1096: /* sizeof (packet_len + pad_len + payload + padding) */
1.201 markus 1097: len = sshbuf_len(state->outgoing_packet);
1098: cp = sshbuf_mutable_ptr(state->outgoing_packet);
1099: if (cp == NULL) {
1100: r = SSH_ERR_INTERNAL_ERROR;
1101: goto out;
1102: }
1.25 markus 1103: /* packet_length includes payload, padding and padding length field */
1.201 markus 1104: POKE_U32(cp, len - 4);
1.89 markus 1105: cp[4] = padlen;
1.178 markus 1106: DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1107: len, padlen, aadlen));
1.25 markus 1108:
1109: /* compute MAC over seqnr and packet(length fields, payload, padding) */
1.178 markus 1110: if (mac && mac->enabled && !mac->etm) {
1.201 markus 1111: if ((r = mac_compute(mac, state->p_send.seqnr,
1112: sshbuf_ptr(state->outgoing_packet), len,
1.200 markus 1113: macbuf, sizeof(macbuf))) != 0)
1.201 markus 1114: goto out;
1115: DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1.25 markus 1116: }
1117: /* encrypt packet and append to output buffer. */
1.201 markus 1118: if ((r = sshbuf_reserve(state->output,
1119: sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1120: goto out;
1.235 djm 1121: if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1.201 markus 1122: sshbuf_ptr(state->outgoing_packet),
1123: len - aadlen, aadlen, authlen)) != 0)
1124: goto out;
1.25 markus 1125: /* append unencrypted MAC */
1.178 markus 1126: if (mac && mac->enabled) {
1127: if (mac->etm) {
1128: /* EtM: compute mac over aadlen + cipher text */
1.201 markus 1129: if ((r = mac_compute(mac, state->p_send.seqnr,
1130: cp, len, macbuf, sizeof(macbuf))) != 0)
1131: goto out;
1.178 markus 1132: DBG(debug("done calc MAC(EtM) out #%d",
1.201 markus 1133: state->p_send.seqnr));
1.178 markus 1134: }
1.201 markus 1135: if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1136: goto out;
1.178 markus 1137: }
1.25 markus 1138: #ifdef PACKET_DEBUG
1139: fprintf(stderr, "encrypted: ");
1.201 markus 1140: sshbuf_dump(state->output, stderr);
1.25 markus 1141: #endif
1.29 markus 1142: /* increment sequence number for outgoing packets */
1.201 markus 1143: if (++state->p_send.seqnr == 0)
1.106 itojun 1144: logit("outgoing seqnr wraps around");
1.201 markus 1145: if (++state->p_send.packets == 0)
1146: if (!(ssh->compat & SSH_BUG_NOREKEY))
1147: return SSH_ERR_NEED_REKEY;
1148: state->p_send.blocks += len / block_size;
1149: state->p_send.bytes += len;
1150: sshbuf_reset(state->outgoing_packet);
1.25 markus 1151:
1.57 markus 1152: if (type == SSH2_MSG_NEWKEYS)
1.201 markus 1153: r = ssh_set_newkeys(ssh, MODE_OUT);
1154: else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1155: r = ssh_packet_enable_delayed_compress(ssh);
1156: else
1157: r = 0;
1158: out:
1159: return r;
1.25 markus 1160: }
1161:
1.228 djm 1162: /* returns non-zero if the specified packet type is usec by KEX */
1163: static int
1164: ssh_packet_type_is_kex(u_char type)
1165: {
1166: return
1167: type >= SSH2_MSG_TRANSPORT_MIN &&
1168: type <= SSH2_MSG_TRANSPORT_MAX &&
1169: type != SSH2_MSG_SERVICE_REQUEST &&
1170: type != SSH2_MSG_SERVICE_ACCEPT &&
1171: type != SSH2_MSG_EXT_INFO;
1172: }
1173:
1.201 markus 1174: int
1175: ssh_packet_send2(struct ssh *ssh)
1.105 markus 1176: {
1.201 markus 1177: struct session_state *state = ssh->state;
1.105 markus 1178: struct packet *p;
1.201 markus 1179: u_char type;
1.228 djm 1180: int r, need_rekey;
1.105 markus 1181:
1.228 djm 1182: if (sshbuf_len(state->outgoing_packet) < 6)
1183: return SSH_ERR_INTERNAL_ERROR;
1.201 markus 1184: type = sshbuf_ptr(state->outgoing_packet)[5];
1.228 djm 1185: need_rekey = !ssh_packet_type_is_kex(type) &&
1186: ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1.105 markus 1187:
1.228 djm 1188: /*
1189: * During rekeying we can only send key exchange messages.
1190: * Queue everything else.
1191: */
1192: if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1193: if (need_rekey)
1194: debug3("%s: rekex triggered", __func__);
1195: debug("enqueue packet: %u", type);
1196: p = calloc(1, sizeof(*p));
1197: if (p == NULL)
1198: return SSH_ERR_ALLOC_FAIL;
1199: p->type = type;
1200: p->payload = state->outgoing_packet;
1201: TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1202: state->outgoing_packet = sshbuf_new();
1203: if (state->outgoing_packet == NULL)
1204: return SSH_ERR_ALLOC_FAIL;
1205: if (need_rekey) {
1206: /*
1207: * This packet triggered a rekey, so send the
1208: * KEXINIT now.
1209: * NB. reenters this function via kex_start_rekex().
1210: */
1211: return kex_start_rekex(ssh);
1.105 markus 1212: }
1.228 djm 1213: return 0;
1.105 markus 1214: }
1215:
1216: /* rekeying starts with sending KEXINIT */
1217: if (type == SSH2_MSG_KEXINIT)
1.201 markus 1218: state->rekeying = 1;
1.105 markus 1219:
1.201 markus 1220: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1221: return r;
1.105 markus 1222:
1223: /* after a NEWKEYS message we can send the complete queue */
1224: if (type == SSH2_MSG_NEWKEYS) {
1.201 markus 1225: state->rekeying = 0;
1226: state->rekey_time = monotime();
1227: while ((p = TAILQ_FIRST(&state->outgoing))) {
1.105 markus 1228: type = p->type;
1.228 djm 1229: /*
1230: * If this packet triggers a rekex, then skip the
1231: * remaining packets in the queue for now.
1232: * NB. re-enters this function via kex_start_rekex.
1233: */
1234: if (ssh_packet_need_rekeying(ssh,
1235: sshbuf_len(p->payload))) {
1236: debug3("%s: queued packet triggered rekex",
1237: __func__);
1238: return kex_start_rekex(ssh);
1239: }
1.105 markus 1240: debug("dequeue packet: %u", type);
1.201 markus 1241: sshbuf_free(state->outgoing_packet);
1242: state->outgoing_packet = p->payload;
1243: TAILQ_REMOVE(&state->outgoing, p, next);
1.228 djm 1244: memset(p, 0, sizeof(*p));
1.186 djm 1245: free(p);
1.201 markus 1246: if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1247: return r;
1.105 markus 1248: }
1249: }
1.201 markus 1250: return 0;
1.25 markus 1251: }
1252:
1253: /*
1.16 markus 1254: * Waits until a packet has been received, and returns its type. Note that
1255: * no other data is processed until this returns, so this function should not
1256: * be used during the interactive session.
1257: */
1.1 deraadt 1258:
1.2 provos 1259: int
1.201 markus 1260: ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.1 deraadt 1261: {
1.201 markus 1262: struct session_state *state = ssh->state;
1.222 markus 1263: int len, r, ms_remain;
1.56 millert 1264: fd_set *setp;
1.14 markus 1265: char buf[8192];
1.155 deraadt 1266: struct timeval timeout, start, *timeoutp = NULL;
1267:
1.25 markus 1268: DBG(debug("packet_read()"));
1.14 markus 1269:
1.214 deraadt 1270: setp = calloc(howmany(state->connection_in + 1,
1.161 andreas 1271: NFDBITS), sizeof(fd_mask));
1.201 markus 1272: if (setp == NULL)
1273: return SSH_ERR_ALLOC_FAIL;
1.56 millert 1274:
1.205 djm 1275: /*
1276: * Since we are blocking, ensure that all written packets have
1277: * been sent.
1278: */
1.210 markus 1279: if ((r = ssh_packet_write_wait(ssh)) != 0)
1280: goto out;
1.14 markus 1281:
1282: /* Stay in the loop until we have received a complete packet. */
1283: for (;;) {
1284: /* Try to read a packet from the buffer. */
1.201 markus 1285: r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1286: if (r != 0)
1287: break;
1.14 markus 1288: /* If we got a packet, return it. */
1.201 markus 1289: if (*typep != SSH_MSG_NONE)
1290: break;
1.16 markus 1291: /*
1292: * Otherwise, wait for some data to arrive, add it to the
1293: * buffer, and try again.
1294: */
1.201 markus 1295: memset(setp, 0, howmany(state->connection_in + 1,
1.161 andreas 1296: NFDBITS) * sizeof(fd_mask));
1.201 markus 1297: FD_SET(state->connection_in, setp);
1.16 markus 1298:
1.201 markus 1299: if (state->packet_timeout_ms > 0) {
1300: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1301: timeoutp = &timeout;
1302: }
1.14 markus 1303: /* Wait for some data to arrive. */
1.154 dtucker 1304: for (;;) {
1.201 markus 1305: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1306: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1307: monotime_tv(&start);
1.154 dtucker 1308: }
1.201 markus 1309: if ((r = select(state->connection_in + 1, setp,
1.161 andreas 1310: NULL, NULL, timeoutp)) >= 0)
1.154 dtucker 1311: break;
1.270 dtucker 1312: if (errno != EAGAIN && errno != EINTR) {
1313: r = SSH_ERR_SYSTEM_ERROR;
1314: goto out;
1315: }
1.201 markus 1316: if (state->packet_timeout_ms == -1)
1.154 dtucker 1317: continue;
1318: ms_subtract_diff(&start, &ms_remain);
1319: if (ms_remain <= 0) {
1.201 markus 1320: r = 0;
1.154 dtucker 1321: break;
1322: }
1323: }
1.246 djm 1324: if (r == 0) {
1325: r = SSH_ERR_CONN_TIMEOUT;
1326: goto out;
1327: }
1.14 markus 1328: /* Read data from the socket. */
1.222 markus 1329: len = read(state->connection_in, buf, sizeof(buf));
1.210 markus 1330: if (len == 0) {
1331: r = SSH_ERR_CONN_CLOSED;
1332: goto out;
1333: }
1334: if (len < 0) {
1335: r = SSH_ERR_SYSTEM_ERROR;
1336: goto out;
1337: }
1.204 djm 1338:
1.14 markus 1339: /* Append it to the buffer. */
1.204 djm 1340: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1.210 markus 1341: goto out;
1.14 markus 1342: }
1.210 markus 1343: out:
1.201 markus 1344: free(setp);
1345: return r;
1.1 deraadt 1346: }
1347:
1.77 djm 1348: int
1.201 markus 1349: ssh_packet_read(struct ssh *ssh)
1.77 djm 1350: {
1.201 markus 1351: u_char type;
1352: int r;
1353:
1354: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1355: fatal("%s: %s", __func__, ssh_err(r));
1356: return type;
1.77 djm 1357: }
1358:
1.16 markus 1359: /*
1360: * Waits until a packet has been received, verifies that its type matches
1361: * that given, and gives a fatal error and exits if there is a mismatch.
1362: */
1.1 deraadt 1363:
1.205 djm 1364: int
1365: ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1.1 deraadt 1366: {
1.205 djm 1367: int r;
1368: u_char type;
1.1 deraadt 1369:
1.205 djm 1370: if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1371: return r;
1372: if (type != expected_type) {
1373: if ((r = sshpkt_disconnect(ssh,
1.201 markus 1374: "Protocol error: expected packet type %d, got %d",
1.205 djm 1375: expected_type, type)) != 0)
1376: return r;
1377: return SSH_ERR_PROTOCOL_ERROR;
1378: }
1379: return 0;
1.1 deraadt 1380: }
1.14 markus 1381:
1.242 markus 1382: static int
1383: ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1384: {
1385: struct session_state *state = ssh->state;
1386: const u_char *cp;
1387: size_t need;
1388: int r;
1389:
1390: if (ssh->kex)
1391: return SSH_ERR_INTERNAL_ERROR;
1392: *typep = SSH_MSG_NONE;
1393: cp = sshbuf_ptr(state->input);
1394: if (state->packlen == 0) {
1395: if (sshbuf_len(state->input) < 4 + 1)
1396: return 0; /* packet is incomplete */
1397: state->packlen = PEEK_U32(cp);
1398: if (state->packlen < 4 + 1 ||
1399: state->packlen > PACKET_MAX_SIZE)
1400: return SSH_ERR_MESSAGE_INCOMPLETE;
1401: }
1402: need = state->packlen + 4;
1403: if (sshbuf_len(state->input) < need)
1404: return 0; /* packet is incomplete */
1405: sshbuf_reset(state->incoming_packet);
1406: if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1407: state->packlen)) != 0 ||
1408: (r = sshbuf_consume(state->input, need)) != 0 ||
1409: (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1410: (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1411: return r;
1412: if (ssh_packet_log_type(*typep))
1413: debug3("%s: type %u", __func__, *typep);
1414: /* sshbuf_dump(state->incoming_packet, stderr); */
1415: /* reset for next packet */
1416: state->packlen = 0;
1417: return r;
1418: }
1419:
1.201 markus 1420: int
1421: ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1422: {
1.201 markus 1423: struct session_state *state = ssh->state;
1.40 markus 1424: u_int padlen, need;
1.231 djm 1425: u_char *cp;
1.201 markus 1426: u_int maclen, aadlen = 0, authlen = 0, block_size;
1427: struct sshenc *enc = NULL;
1428: struct sshmac *mac = NULL;
1429: struct sshcomp *comp = NULL;
1.200 markus 1430: int r;
1.201 markus 1431:
1.242 markus 1432: if (state->mux)
1433: return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1434:
1.201 markus 1435: *typep = SSH_MSG_NONE;
1436:
1437: if (state->packet_discard)
1438: return 0;
1439:
1440: if (state->newkeys[MODE_IN] != NULL) {
1441: enc = &state->newkeys[MODE_IN]->enc;
1442: mac = &state->newkeys[MODE_IN]->mac;
1443: comp = &state->newkeys[MODE_IN]->comp;
1.180 markus 1444: /* disable mac for authenticated encryption */
1445: if ((authlen = cipher_authlen(enc->cipher)) != 0)
1446: mac = NULL;
1.25 markus 1447: }
1448: maclen = mac && mac->enabled ? mac->mac_len : 0;
1.88 markus 1449: block_size = enc ? enc->block_size : 8;
1.180 markus 1450: aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1.25 markus 1451:
1.201 markus 1452: if (aadlen && state->packlen == 0) {
1.235 djm 1453: if (cipher_get_length(state->receive_context,
1.201 markus 1454: &state->packlen, state->p_read.seqnr,
1455: sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1456: return 0;
1457: if (state->packlen < 1 + 4 ||
1458: state->packlen > PACKET_MAX_SIZE) {
1.178 markus 1459: #ifdef PACKET_DEBUG
1.201 markus 1460: sshbuf_dump(state->input, stderr);
1.178 markus 1461: #endif
1.201 markus 1462: logit("Bad packet length %u.", state->packlen);
1463: if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1464: return r;
1.217 djm 1465: return SSH_ERR_CONN_CORRUPT;
1.178 markus 1466: }
1.201 markus 1467: sshbuf_reset(state->incoming_packet);
1468: } else if (state->packlen == 0) {
1.25 markus 1469: /*
1470: * check if input size is less than the cipher block size,
1471: * decrypt first block and extract length of incoming packet
1472: */
1.201 markus 1473: if (sshbuf_len(state->input) < block_size)
1474: return 0;
1475: sshbuf_reset(state->incoming_packet);
1476: if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1477: &cp)) != 0)
1478: goto out;
1.235 djm 1479: if ((r = cipher_crypt(state->receive_context,
1.201 markus 1480: state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1481: block_size, 0, 0)) != 0)
1482: goto out;
1483: state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1484: if (state->packlen < 1 + 4 ||
1485: state->packlen > PACKET_MAX_SIZE) {
1.110 markus 1486: #ifdef PACKET_DEBUG
1.201 markus 1487: fprintf(stderr, "input: \n");
1488: sshbuf_dump(state->input, stderr);
1489: fprintf(stderr, "incoming_packet: \n");
1490: sshbuf_dump(state->incoming_packet, stderr);
1.110 markus 1491: #endif
1.201 markus 1492: logit("Bad packet length %u.", state->packlen);
1.234 markus 1493: return ssh_packet_start_discard(ssh, enc, mac, 0,
1494: PACKET_MAX_SIZE);
1.25 markus 1495: }
1.201 markus 1496: if ((r = sshbuf_consume(state->input, block_size)) != 0)
1497: goto out;
1.25 markus 1498: }
1.201 markus 1499: DBG(debug("input: packet len %u", state->packlen+4));
1500:
1.178 markus 1501: if (aadlen) {
1502: /* only the payload is encrypted */
1.201 markus 1503: need = state->packlen;
1.178 markus 1504: } else {
1505: /*
1506: * the payload size and the payload are encrypted, but we
1507: * have a partial packet of block_size bytes
1508: */
1.201 markus 1509: need = 4 + state->packlen - block_size;
1.178 markus 1510: }
1.180 markus 1511: DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1512: " aadlen %d", block_size, need, maclen, authlen, aadlen));
1.158 markus 1513: if (need % block_size != 0) {
1514: logit("padding error: need %d block %d mod %d",
1.25 markus 1515: need, block_size, need % block_size);
1.234 markus 1516: return ssh_packet_start_discard(ssh, enc, mac, 0,
1517: PACKET_MAX_SIZE - block_size);
1.158 markus 1518: }
1.25 markus 1519: /*
1520: * check if the entire packet has been received and
1.178 markus 1521: * decrypt into incoming_packet:
1522: * 'aadlen' bytes are unencrypted, but authenticated.
1.180 markus 1523: * 'need' bytes are encrypted, followed by either
1524: * 'authlen' bytes of authentication tag or
1.178 markus 1525: * 'maclen' bytes of message authentication code.
1.25 markus 1526: */
1.201 markus 1527: if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1.231 djm 1528: return 0; /* packet is incomplete */
1.25 markus 1529: #ifdef PACKET_DEBUG
1530: fprintf(stderr, "read_poll enc/full: ");
1.201 markus 1531: sshbuf_dump(state->input, stderr);
1.25 markus 1532: #endif
1.231 djm 1533: /* EtM: check mac over encrypted input */
1.201 markus 1534: if (mac && mac->enabled && mac->etm) {
1.231 djm 1535: if ((r = mac_check(mac, state->p_read.seqnr,
1.201 markus 1536: sshbuf_ptr(state->input), aadlen + need,
1.231 djm 1537: sshbuf_ptr(state->input) + aadlen + need + authlen,
1538: maclen)) != 0) {
1539: if (r == SSH_ERR_MAC_INVALID)
1540: logit("Corrupted MAC on input.");
1.201 markus 1541: goto out;
1.231 djm 1542: }
1.201 markus 1543: }
1544: if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1545: &cp)) != 0)
1546: goto out;
1.235 djm 1547: if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1.201 markus 1548: sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1549: goto out;
1550: if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1551: goto out;
1.29 markus 1552: if (mac && mac->enabled) {
1.231 djm 1553: /* Not EtM: check MAC over cleartext */
1554: if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1555: sshbuf_ptr(state->incoming_packet),
1556: sshbuf_len(state->incoming_packet),
1557: sshbuf_ptr(state->input), maclen)) != 0) {
1558: if (r != SSH_ERR_MAC_INVALID)
1.201 markus 1559: goto out;
1.159 markus 1560: logit("Corrupted MAC on input.");
1.247 markus 1561: if (need + block_size > PACKET_MAX_SIZE)
1.201 markus 1562: return SSH_ERR_INTERNAL_ERROR;
1563: return ssh_packet_start_discard(ssh, enc, mac,
1.234 markus 1564: sshbuf_len(state->incoming_packet),
1.247 markus 1565: PACKET_MAX_SIZE - need - block_size);
1.201 markus 1566: }
1.231 djm 1567: /* Remove MAC from input buffer */
1.201 markus 1568: DBG(debug("MAC #%d ok", state->p_read.seqnr));
1569: if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1570: goto out;
1.25 markus 1571: }
1.77 djm 1572: if (seqnr_p != NULL)
1.201 markus 1573: *seqnr_p = state->p_read.seqnr;
1574: if (++state->p_read.seqnr == 0)
1.106 itojun 1575: logit("incoming seqnr wraps around");
1.201 markus 1576: if (++state->p_read.packets == 0)
1577: if (!(ssh->compat & SSH_BUG_NOREKEY))
1578: return SSH_ERR_NEED_REKEY;
1579: state->p_read.blocks += (state->packlen + 4) / block_size;
1580: state->p_read.bytes += state->packlen + 4;
1.25 markus 1581:
1582: /* get padlen */
1.201 markus 1583: padlen = sshbuf_ptr(state->incoming_packet)[4];
1.25 markus 1584: DBG(debug("input: padlen %d", padlen));
1.205 djm 1585: if (padlen < 4) {
1586: if ((r = sshpkt_disconnect(ssh,
1587: "Corrupted padlen %d on input.", padlen)) != 0 ||
1588: (r = ssh_packet_write_wait(ssh)) != 0)
1589: return r;
1590: return SSH_ERR_CONN_CORRUPT;
1591: }
1.25 markus 1592:
1593: /* skip packet size + padlen, discard padding */
1.201 markus 1594: if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1595: ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1596: goto out;
1.25 markus 1597:
1.201 markus 1598: DBG(debug("input: len before de-compress %zd",
1599: sshbuf_len(state->incoming_packet)));
1.25 markus 1600: if (comp && comp->enabled) {
1.201 markus 1601: sshbuf_reset(state->compression_buffer);
1602: if ((r = uncompress_buffer(ssh, state->incoming_packet,
1603: state->compression_buffer)) != 0)
1604: goto out;
1605: sshbuf_reset(state->incoming_packet);
1606: if ((r = sshbuf_putb(state->incoming_packet,
1607: state->compression_buffer)) != 0)
1608: goto out;
1609: DBG(debug("input: len after de-compress %zd",
1610: sshbuf_len(state->incoming_packet)));
1.25 markus 1611: }
1612: /*
1613: * get packet type, implies consume.
1614: * return length of payload (without type field)
1615: */
1.201 markus 1616: if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1617: goto out;
1.226 djm 1618: if (ssh_packet_log_type(*typep))
1619: debug3("receive packet: type %u", *typep);
1.205 djm 1620: if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1621: if ((r = sshpkt_disconnect(ssh,
1622: "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1623: (r = ssh_packet_write_wait(ssh)) != 0)
1624: return r;
1625: return SSH_ERR_PROTOCOL_ERROR;
1626: }
1.243 djm 1627: if (state->hook_in != NULL &&
1628: (r = state->hook_in(ssh, state->incoming_packet, typep,
1629: state->hook_in_ctx)) != 0)
1630: return r;
1.238 markus 1631: if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1.201 markus 1632: r = ssh_packet_enable_delayed_compress(ssh);
1633: else
1634: r = 0;
1.25 markus 1635: #ifdef PACKET_DEBUG
1.201 markus 1636: fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1637: sshbuf_dump(state->incoming_packet, stderr);
1.25 markus 1638: #endif
1.62 markus 1639: /* reset for next packet */
1.201 markus 1640: state->packlen = 0;
1.228 djm 1641:
1642: /* do we need to rekey? */
1643: if (ssh_packet_need_rekeying(ssh, 0)) {
1644: debug3("%s: rekex triggered", __func__);
1645: if ((r = kex_start_rekex(ssh)) != 0)
1646: return r;
1647: }
1.201 markus 1648: out:
1649: return r;
1.25 markus 1650: }
1651:
1652: int
1.201 markus 1653: ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1.25 markus 1654: {
1.201 markus 1655: struct session_state *state = ssh->state;
1.96 deraadt 1656: u_int reason, seqnr;
1.201 markus 1657: int r;
1658: u_char *msg;
1.62 markus 1659:
1.25 markus 1660: for (;;) {
1.201 markus 1661: msg = NULL;
1.249 djm 1662: r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1663: if (r != 0)
1664: return r;
1665: if (*typep) {
1666: state->keep_alive_timeouts = 0;
1667: DBG(debug("received packet type %d", *typep));
1668: }
1669: switch (*typep) {
1670: case SSH2_MSG_IGNORE:
1671: debug3("Received SSH2_MSG_IGNORE");
1672: break;
1673: case SSH2_MSG_DEBUG:
1674: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1675: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1676: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1677: free(msg);
1.201 markus 1678: return r;
1.48 stevesk 1679: }
1.249 djm 1680: debug("Remote: %.900s", msg);
1681: free(msg);
1682: break;
1683: case SSH2_MSG_DISCONNECT:
1684: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1685: (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1686: return r;
1687: /* Ignore normal client exit notifications */
1688: do_log2(ssh->state->server_side &&
1689: reason == SSH2_DISCONNECT_BY_APPLICATION ?
1690: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1691: "Received disconnect from %s port %d:"
1692: "%u: %.400s", ssh_remote_ipaddr(ssh),
1693: ssh_remote_port(ssh), reason, msg);
1694: free(msg);
1695: return SSH_ERR_DISCONNECTED;
1696: case SSH2_MSG_UNIMPLEMENTED:
1697: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1698: return r;
1699: debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1700: seqnr);
1701: break;
1702: default:
1703: return 0;
1.25 markus 1704: }
1705: }
1706: }
1707:
1.16 markus 1708: /*
1709: * Buffers the given amount of input characters. This is intended to be used
1710: * together with packet_read_poll.
1711: */
1.1 deraadt 1712:
1.204 djm 1713: int
1.201 markus 1714: ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1.1 deraadt 1715: {
1.201 markus 1716: struct session_state *state = ssh->state;
1717: int r;
1718:
1719: if (state->packet_discard) {
1720: state->keep_alive_timeouts = 0; /* ?? */
1721: if (len >= state->packet_discard) {
1722: if ((r = ssh_packet_stop_discard(ssh)) != 0)
1.204 djm 1723: return r;
1.201 markus 1724: }
1725: state->packet_discard -= len;
1.204 djm 1726: return 0;
1.159 markus 1727: }
1.201 markus 1728: if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1.204 djm 1729: return r;
1730:
1731: return 0;
1.28 markus 1732: }
1733:
1734: int
1.201 markus 1735: ssh_packet_remaining(struct ssh *ssh)
1.28 markus 1736: {
1.201 markus 1737: return sshbuf_len(ssh->state->incoming_packet);
1.1 deraadt 1738: }
1739:
1.16 markus 1740: /*
1741: * Sends a diagnostic message from the server to the client. This message
1742: * can be sent at any time (but not while constructing another message). The
1743: * message is printed immediately, but only if the client is being executed
1744: * in verbose mode. These messages are primarily intended to ease debugging
1745: * authentication problems. The length of the formatted message must not
1.205 djm 1746: * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1.16 markus 1747: */
1.2 provos 1748: void
1.201 markus 1749: ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1750: {
1.14 markus 1751: char buf[1024];
1752: va_list args;
1.201 markus 1753: int r;
1.39 markus 1754:
1.249 djm 1755: if ((ssh->compat & SSH_BUG_DEBUG))
1.39 markus 1756: return;
1.14 markus 1757:
1758: va_start(args, fmt);
1759: vsnprintf(buf, sizeof(buf), fmt, args);
1760: va_end(args);
1.265 djm 1761:
1762: debug3("sending debug message: %s", buf);
1.14 markus 1763:
1.249 djm 1764: if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1765: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1766: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1767: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1768: (r = sshpkt_send(ssh)) != 0 ||
1769: (r = ssh_packet_write_wait(ssh)) != 0)
1.205 djm 1770: fatal("%s: %s", __func__, ssh_err(r));
1771: }
1772:
1.268 dtucker 1773: void
1774: sshpkt_fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1.245 djm 1775: {
1776: snprintf(s, l, "%.200s%s%s port %d",
1777: ssh->log_preamble ? ssh->log_preamble : "",
1778: ssh->log_preamble ? " " : "",
1779: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1780: }
1781:
1.205 djm 1782: /*
1783: * Pretty-print connection-terminating errors and exit.
1784: */
1785: void
1786: sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
1787: {
1.245 djm 1788: char remote_id[512];
1789:
1.268 dtucker 1790: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.245 djm 1791:
1.205 djm 1792: switch (r) {
1793: case SSH_ERR_CONN_CLOSED:
1.257 markus 1794: ssh_packet_clear_keys(ssh);
1.245 djm 1795: logdie("Connection closed by %s", remote_id);
1.205 djm 1796: case SSH_ERR_CONN_TIMEOUT:
1.257 markus 1797: ssh_packet_clear_keys(ssh);
1.245 djm 1798: logdie("Connection %s %s timed out",
1799: ssh->state->server_side ? "from" : "to", remote_id);
1.212 djm 1800: case SSH_ERR_DISCONNECTED:
1.257 markus 1801: ssh_packet_clear_keys(ssh);
1.245 djm 1802: logdie("Disconnected from %s", remote_id);
1.212 djm 1803: case SSH_ERR_SYSTEM_ERROR:
1.257 markus 1804: if (errno == ECONNRESET) {
1805: ssh_packet_clear_keys(ssh);
1.245 djm 1806: logdie("Connection reset by %s", remote_id);
1.257 markus 1807: }
1.213 djm 1808: /* FALLTHROUGH */
1809: case SSH_ERR_NO_CIPHER_ALG_MATCH:
1810: case SSH_ERR_NO_MAC_ALG_MATCH:
1811: case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1812: case SSH_ERR_NO_KEX_ALG_MATCH:
1813: case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1814: if (ssh && ssh->kex && ssh->kex->failed_choice) {
1.257 markus 1815: ssh_packet_clear_keys(ssh);
1.245 djm 1816: logdie("Unable to negotiate with %s: %s. "
1817: "Their offer: %s", remote_id, ssh_err(r),
1.220 djm 1818: ssh->kex->failed_choice);
1.212 djm 1819: }
1820: /* FALLTHROUGH */
1.205 djm 1821: default:
1.257 markus 1822: ssh_packet_clear_keys(ssh);
1.245 djm 1823: logdie("%s%sConnection %s %s: %s",
1.205 djm 1824: tag != NULL ? tag : "", tag != NULL ? ": " : "",
1.220 djm 1825: ssh->state->server_side ? "from" : "to",
1.245 djm 1826: remote_id, ssh_err(r));
1.205 djm 1827: }
1.1 deraadt 1828: }
1829:
1.16 markus 1830: /*
1831: * Logs the error plus constructs and sends a disconnect packet, closes the
1832: * connection, and exits. This function never returns. The error message
1833: * should not contain a newline. The length of the formatted message must
1834: * not exceed 1024 bytes.
1835: */
1.2 provos 1836: void
1.201 markus 1837: ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1.1 deraadt 1838: {
1.245 djm 1839: char buf[1024], remote_id[512];
1.14 markus 1840: va_list args;
1841: static int disconnecting = 0;
1.201 markus 1842: int r;
1.97 deraadt 1843:
1.14 markus 1844: if (disconnecting) /* Guard against recursive invocations. */
1845: fatal("packet_disconnect called recursively.");
1846: disconnecting = 1;
1847:
1.16 markus 1848: /*
1849: * Format the message. Note that the caller must make sure the
1850: * message is of limited size.
1851: */
1.268 dtucker 1852: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1.14 markus 1853: va_start(args, fmt);
1854: vsnprintf(buf, sizeof(buf), fmt, args);
1855: va_end(args);
1856:
1.99 markus 1857: /* Display the error locally */
1.245 djm 1858: logit("Disconnecting %s: %.100s", remote_id, buf);
1.99 markus 1859:
1.205 djm 1860: /*
1861: * Send the disconnect message to the other side, and wait
1862: * for it to get sent.
1863: */
1864: if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1865: sshpkt_fatal(ssh, __func__, r);
1866:
1867: if ((r = ssh_packet_write_wait(ssh)) != 0)
1868: sshpkt_fatal(ssh, __func__, r);
1.14 markus 1869:
1870: /* Close the connection. */
1.201 markus 1871: ssh_packet_close(ssh);
1.112 markus 1872: cleanup_exit(255);
1.1 deraadt 1873: }
1874:
1.205 djm 1875: /*
1876: * Checks if there is any buffered output, and tries to write some of
1877: * the output.
1878: */
1879: int
1.201 markus 1880: ssh_packet_write_poll(struct ssh *ssh)
1.1 deraadt 1881: {
1.201 markus 1882: struct session_state *state = ssh->state;
1883: int len = sshbuf_len(state->output);
1.222 markus 1884: int r;
1.97 deraadt 1885:
1.14 markus 1886: if (len > 0) {
1.222 markus 1887: len = write(state->connection_out,
1888: sshbuf_ptr(state->output), len);
1.156 djm 1889: if (len == -1) {
1890: if (errno == EINTR || errno == EAGAIN)
1.205 djm 1891: return 0;
1892: return SSH_ERR_SYSTEM_ERROR;
1.14 markus 1893: }
1.222 markus 1894: if (len == 0)
1.205 djm 1895: return SSH_ERR_CONN_CLOSED;
1.201 markus 1896: if ((r = sshbuf_consume(state->output, len)) != 0)
1.205 djm 1897: return r;
1.14 markus 1898: }
1.205 djm 1899: return 0;
1.1 deraadt 1900: }
1901:
1.16 markus 1902: /*
1903: * Calls packet_write_poll repeatedly until all pending output data has been
1904: * written.
1905: */
1.205 djm 1906: int
1.201 markus 1907: ssh_packet_write_wait(struct ssh *ssh)
1.1 deraadt 1908: {
1.56 millert 1909: fd_set *setp;
1.205 djm 1910: int ret, r, ms_remain = 0;
1.154 dtucker 1911: struct timeval start, timeout, *timeoutp = NULL;
1.201 markus 1912: struct session_state *state = ssh->state;
1.56 millert 1913:
1.214 deraadt 1914: setp = calloc(howmany(state->connection_out + 1,
1.161 andreas 1915: NFDBITS), sizeof(fd_mask));
1.201 markus 1916: if (setp == NULL)
1.205 djm 1917: return SSH_ERR_ALLOC_FAIL;
1.216 gsoares 1918: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1919: free(setp);
1.215 djm 1920: return r;
1.216 gsoares 1921: }
1.201 markus 1922: while (ssh_packet_have_data_to_write(ssh)) {
1923: memset(setp, 0, howmany(state->connection_out + 1,
1.161 andreas 1924: NFDBITS) * sizeof(fd_mask));
1.201 markus 1925: FD_SET(state->connection_out, setp);
1.154 dtucker 1926:
1.201 markus 1927: if (state->packet_timeout_ms > 0) {
1928: ms_remain = state->packet_timeout_ms;
1.154 dtucker 1929: timeoutp = &timeout;
1930: }
1931: for (;;) {
1.201 markus 1932: if (state->packet_timeout_ms != -1) {
1.154 dtucker 1933: ms_to_timeval(&timeout, ms_remain);
1.267 dtucker 1934: monotime_tv(&start);
1.154 dtucker 1935: }
1.201 markus 1936: if ((ret = select(state->connection_out + 1,
1.161 andreas 1937: NULL, setp, NULL, timeoutp)) >= 0)
1.154 dtucker 1938: break;
1.161 andreas 1939: if (errno != EAGAIN && errno != EINTR)
1.154 dtucker 1940: break;
1.201 markus 1941: if (state->packet_timeout_ms == -1)
1.154 dtucker 1942: continue;
1943: ms_subtract_diff(&start, &ms_remain);
1944: if (ms_remain <= 0) {
1945: ret = 0;
1946: break;
1947: }
1948: }
1949: if (ret == 0) {
1.205 djm 1950: free(setp);
1951: return SSH_ERR_CONN_TIMEOUT;
1952: }
1953: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1954: free(setp);
1955: return r;
1.154 dtucker 1956: }
1.14 markus 1957: }
1.186 djm 1958: free(setp);
1.205 djm 1959: return 0;
1.1 deraadt 1960: }
1961:
1962: /* Returns true if there is buffered data to write to the connection. */
1963:
1.2 provos 1964: int
1.201 markus 1965: ssh_packet_have_data_to_write(struct ssh *ssh)
1.1 deraadt 1966: {
1.201 markus 1967: return sshbuf_len(ssh->state->output) != 0;
1.1 deraadt 1968: }
1969:
1970: /* Returns true if there is not too much data to write to the connection. */
1971:
1.2 provos 1972: int
1.201 markus 1973: ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1.1 deraadt 1974: {
1.201 markus 1975: if (ssh->state->interactive_mode)
1976: return sshbuf_len(ssh->state->output) < 16384;
1.14 markus 1977: else
1.201 markus 1978: return sshbuf_len(ssh->state->output) < 128 * 1024;
1.1 deraadt 1979: }
1980:
1.201 markus 1981: void
1982: ssh_packet_set_tos(struct ssh *ssh, int tos)
1.101 markus 1983: {
1.263 djm 1984: if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
1.101 markus 1985: return;
1.201 markus 1986: switch (ssh_packet_connection_af(ssh)) {
1.173 djm 1987: case AF_INET:
1988: debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1.201 markus 1989: if (setsockopt(ssh->state->connection_in,
1.173 djm 1990: IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
1991: error("setsockopt IP_TOS %d: %.100s:",
1992: tos, strerror(errno));
1993: break;
1994: case AF_INET6:
1995: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1.201 markus 1996: if (setsockopt(ssh->state->connection_in,
1.173 djm 1997: IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
1998: error("setsockopt IPV6_TCLASS %d: %.100s:",
1999: tos, strerror(errno));
2000: break;
2001: }
1.101 markus 2002: }
2003:
1.1 deraadt 2004: /* Informs that the current session is interactive. Sets IP flags for that. */
2005:
1.2 provos 2006: void
1.201 markus 2007: ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
1.1 deraadt 2008: {
1.201 markus 2009: struct session_state *state = ssh->state;
2010:
2011: if (state->set_interactive_called)
1.43 markus 2012: return;
1.201 markus 2013: state->set_interactive_called = 1;
1.1 deraadt 2014:
1.14 markus 2015: /* Record that we are in interactive mode. */
1.201 markus 2016: state->interactive_mode = interactive;
1.1 deraadt 2017:
1.19 markus 2018: /* Only set socket options if using a socket. */
1.201 markus 2019: if (!ssh_packet_connection_is_on_socket(ssh))
1.14 markus 2020: return;
1.201 markus 2021: set_nodelay(state->connection_in);
2022: ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2023: qos_bulk);
1.1 deraadt 2024: }
2025:
2026: /* Returns true if the current connection is interactive. */
2027:
1.2 provos 2028: int
1.201 markus 2029: ssh_packet_is_interactive(struct ssh *ssh)
1.1 deraadt 2030: {
1.201 markus 2031: return ssh->state->interactive_mode;
1.12 markus 2032: }
2033:
1.113 deraadt 2034: int
1.201 markus 2035: ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
1.12 markus 2036: {
1.201 markus 2037: struct session_state *state = ssh->state;
2038:
2039: if (state->set_maxsize_called) {
1.106 itojun 2040: logit("packet_set_maxsize: called twice: old %d new %d",
1.201 markus 2041: state->max_packet_size, s);
1.14 markus 2042: return -1;
2043: }
2044: if (s < 4 * 1024 || s > 1024 * 1024) {
1.106 itojun 2045: logit("packet_set_maxsize: bad size %d", s);
1.14 markus 2046: return -1;
2047: }
1.201 markus 2048: state->set_maxsize_called = 1;
1.66 markus 2049: debug("packet_set_maxsize: setting to %d", s);
1.201 markus 2050: state->max_packet_size = s;
1.14 markus 2051: return s;
1.53 markus 2052: }
2053:
1.161 andreas 2054: int
1.201 markus 2055: ssh_packet_inc_alive_timeouts(struct ssh *ssh)
1.161 andreas 2056: {
1.201 markus 2057: return ++ssh->state->keep_alive_timeouts;
1.161 andreas 2058: }
2059:
2060: void
1.201 markus 2061: ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
1.161 andreas 2062: {
1.201 markus 2063: ssh->state->keep_alive_timeouts = ka;
1.161 andreas 2064: }
2065:
2066: u_int
1.201 markus 2067: ssh_packet_get_maxsize(struct ssh *ssh)
1.71 markus 2068: {
1.201 markus 2069: return ssh->state->max_packet_size;
1.71 markus 2070: }
2071:
1.105 markus 2072: void
1.244 dtucker 2073: ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
1.105 markus 2074: {
1.244 dtucker 2075: debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2076: (unsigned int)seconds);
1.201 markus 2077: ssh->state->rekey_limit = bytes;
2078: ssh->state->rekey_interval = seconds;
1.184 dtucker 2079: }
2080:
2081: time_t
1.201 markus 2082: ssh_packet_get_rekey_timeout(struct ssh *ssh)
1.184 dtucker 2083: {
2084: time_t seconds;
2085:
1.201 markus 2086: seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
1.187 dtucker 2087: monotime();
1.185 dtucker 2088: return (seconds <= 0 ? 1 : seconds);
1.118 markus 2089: }
2090:
2091: void
1.201 markus 2092: ssh_packet_set_server(struct ssh *ssh)
1.118 markus 2093: {
1.201 markus 2094: ssh->state->server_side = 1;
1.118 markus 2095: }
2096:
2097: void
1.201 markus 2098: ssh_packet_set_authenticated(struct ssh *ssh)
1.118 markus 2099: {
1.201 markus 2100: ssh->state->after_authentication = 1;
1.161 andreas 2101: }
2102:
2103: void *
1.201 markus 2104: ssh_packet_get_input(struct ssh *ssh)
1.161 andreas 2105: {
1.201 markus 2106: return (void *)ssh->state->input;
1.161 andreas 2107: }
2108:
2109: void *
1.201 markus 2110: ssh_packet_get_output(struct ssh *ssh)
1.161 andreas 2111: {
1.201 markus 2112: return (void *)ssh->state->output;
1.166 andreas 2113: }
2114:
1.196 markus 2115: /* Reset after_authentication and reset compression in post-auth privsep */
1.201 markus 2116: static int
2117: ssh_packet_set_postauth(struct ssh *ssh)
1.196 markus 2118: {
1.239 djm 2119: int r;
1.196 markus 2120:
2121: debug("%s: called", __func__);
2122: /* This was set in net child, but is not visible in user child */
1.201 markus 2123: ssh->state->after_authentication = 1;
2124: ssh->state->rekeying = 0;
1.239 djm 2125: if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2126: return r;
1.201 markus 2127: return 0;
2128: }
2129:
2130: /* Packet state (de-)serialization for privsep */
2131:
2132: /* turn kex into a blob for packet state serialization */
2133: static int
2134: kex_to_blob(struct sshbuf *m, struct kex *kex)
2135: {
2136: int r;
2137:
2138: if ((r = sshbuf_put_string(m, kex->session_id,
2139: kex->session_id_len)) != 0 ||
2140: (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
1.269 djm 2141: (r = sshbuf_put_cstring(m, kex->hostkey_alg)) != 0 ||
1.201 markus 2142: (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
1.269 djm 2143: (r = sshbuf_put_u32(m, kex->hostkey_nid)) != 0 ||
1.201 markus 2144: (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2145: (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2146: (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2147: (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2148: (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2149: (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2150: return r;
2151: return 0;
2152: }
2153:
2154: /* turn key exchange results into a blob for packet state serialization */
2155: static int
2156: newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2157: {
2158: struct sshbuf *b;
2159: struct sshcipher_ctx *cc;
2160: struct sshcomp *comp;
2161: struct sshenc *enc;
2162: struct sshmac *mac;
2163: struct newkeys *newkey;
2164: int r;
2165:
2166: if ((newkey = ssh->state->newkeys[mode]) == NULL)
2167: return SSH_ERR_INTERNAL_ERROR;
2168: enc = &newkey->enc;
2169: mac = &newkey->mac;
2170: comp = &newkey->comp;
1.235 djm 2171: cc = (mode == MODE_OUT) ? ssh->state->send_context :
2172: ssh->state->receive_context;
1.201 markus 2173: if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2174: return r;
2175: if ((b = sshbuf_new()) == NULL)
2176: return SSH_ERR_ALLOC_FAIL;
2177: if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2178: (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2179: (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2180: (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2181: (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2182: goto out;
2183: if (cipher_authlen(enc->cipher) == 0) {
2184: if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2185: (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2186: (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2187: goto out;
2188: }
2189: if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2190: (r = sshbuf_put_cstring(b, comp->name)) != 0)
2191: goto out;
2192: r = sshbuf_put_stringb(m, b);
2193: out:
1.221 mmcc 2194: sshbuf_free(b);
1.201 markus 2195: return r;
2196: }
2197:
2198: /* serialize packet state into a blob */
2199: int
2200: ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2201: {
2202: struct session_state *state = ssh->state;
1.249 djm 2203: int r;
1.201 markus 2204:
1.249 djm 2205: if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2206: (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2207: (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2208: (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2209: (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2210: (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2211: (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2212: (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2213: (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2214: (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2215: (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2216: (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
1.255 djm 2217: (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2218: (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2219: (r = sshbuf_put_stringb(m, state->output)) != 0)
1.256 djm 2220: return r;
1.201 markus 2221:
2222: return 0;
2223: }
2224:
2225: /* restore key exchange results from blob for packet state de-serialization */
2226: static int
2227: newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2228: {
2229: struct sshbuf *b = NULL;
2230: struct sshcomp *comp;
2231: struct sshenc *enc;
2232: struct sshmac *mac;
2233: struct newkeys *newkey = NULL;
2234: size_t keylen, ivlen, maclen;
2235: int r;
2236:
2237: if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2238: r = SSH_ERR_ALLOC_FAIL;
2239: goto out;
2240: }
2241: if ((r = sshbuf_froms(m, &b)) != 0)
2242: goto out;
2243: #ifdef DEBUG_PK
2244: sshbuf_dump(b, stderr);
2245: #endif
2246: enc = &newkey->enc;
2247: mac = &newkey->mac;
2248: comp = &newkey->comp;
2249:
2250: if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2251: (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2252: (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2253: (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2254: (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2255: goto out;
1.262 djm 2256: if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2257: r = SSH_ERR_INVALID_FORMAT;
2258: goto out;
2259: }
1.201 markus 2260: if (cipher_authlen(enc->cipher) == 0) {
2261: if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2262: goto out;
2263: if ((r = mac_setup(mac, mac->name)) != 0)
2264: goto out;
2265: if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2266: (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2267: goto out;
2268: if (maclen > mac->key_len) {
2269: r = SSH_ERR_INVALID_FORMAT;
2270: goto out;
2271: }
2272: mac->key_len = maclen;
2273: }
2274: if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2275: (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2276: goto out;
2277: if (sshbuf_len(b) != 0) {
2278: r = SSH_ERR_INVALID_FORMAT;
2279: goto out;
2280: }
2281: enc->key_len = keylen;
2282: enc->iv_len = ivlen;
2283: ssh->kex->newkeys[mode] = newkey;
2284: newkey = NULL;
2285: r = 0;
2286: out:
1.219 mmcc 2287: free(newkey);
1.221 mmcc 2288: sshbuf_free(b);
1.201 markus 2289: return r;
2290: }
2291:
2292: /* restore kex from blob for packet state de-serialization */
2293: static int
2294: kex_from_blob(struct sshbuf *m, struct kex **kexp)
2295: {
2296: struct kex *kex;
2297: int r;
2298:
2299: if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2300: (kex->my = sshbuf_new()) == NULL ||
2301: (kex->peer = sshbuf_new()) == NULL) {
2302: r = SSH_ERR_ALLOC_FAIL;
2303: goto out;
2304: }
2305: if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2306: (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
1.269 djm 2307: (r = sshbuf_get_cstring(m, &kex->hostkey_alg, NULL)) != 0 ||
1.201 markus 2308: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
1.269 djm 2309: (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_nid)) != 0 ||
1.201 markus 2310: (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2311: (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2312: (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2313: (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2314: (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2315: (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2316: goto out;
2317: kex->server = 1;
2318: kex->done = 1;
2319: r = 0;
2320: out:
2321: if (r != 0 || kexp == NULL) {
2322: if (kex != NULL) {
1.221 mmcc 2323: sshbuf_free(kex->my);
2324: sshbuf_free(kex->peer);
1.201 markus 2325: free(kex);
2326: }
2327: if (kexp != NULL)
2328: *kexp = NULL;
2329: } else {
2330: *kexp = kex;
2331: }
2332: return r;
2333: }
2334:
2335: /*
2336: * Restore packet state from content of blob 'm' (de-serialization).
2337: * Note that 'm' will be partially consumed on parsing or any other errors.
2338: */
2339: int
2340: ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2341: {
2342: struct session_state *state = ssh->state;
1.254 djm 2343: const u_char *input, *output;
2344: size_t ilen, olen;
1.201 markus 2345: int r;
2346:
1.249 djm 2347: if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2348: (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2349: (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2350: (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2351: (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2352: (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2353: (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2354: (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2355: (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2356: (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2357: (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2358: (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2359: (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2360: return r;
2361: /*
2362: * We set the time here so that in post-auth privsep slave we
2363: * count from the completion of the authentication.
2364: */
2365: state->rekey_time = monotime();
2366: /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2367: if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2368: (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2369: return r;
1.201 markus 2370:
1.239 djm 2371: if ((r = ssh_packet_set_postauth(ssh)) != 0)
1.201 markus 2372: return r;
2373:
2374: sshbuf_reset(state->input);
2375: sshbuf_reset(state->output);
2376: if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2377: (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2378: (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2379: (r = sshbuf_put(state->output, output, olen)) != 0)
2380: return r;
2381:
2382: if (sshbuf_len(m))
2383: return SSH_ERR_INVALID_FORMAT;
2384: debug3("%s: done", __func__);
2385: return 0;
2386: }
2387:
2388: /* NEW API */
2389:
2390: /* put data to the outgoing packet */
2391:
2392: int
2393: sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2394: {
2395: return sshbuf_put(ssh->state->outgoing_packet, v, len);
2396: }
2397:
2398: int
2399: sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2400: {
2401: return sshbuf_putb(ssh->state->outgoing_packet, b);
2402: }
2403:
2404: int
2405: sshpkt_put_u8(struct ssh *ssh, u_char val)
2406: {
2407: return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2408: }
2409:
2410: int
2411: sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2412: {
2413: return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2414: }
2415:
2416: int
2417: sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2418: {
2419: return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2420: }
2421:
2422: int
2423: sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2424: {
2425: return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2426: }
2427:
2428: int
2429: sshpkt_put_cstring(struct ssh *ssh, const void *v)
2430: {
2431: return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2432: }
2433:
2434: int
2435: sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2436: {
2437: return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2438: }
2439:
1.211 djm 2440: #ifdef WITH_OPENSSL
1.201 markus 2441: int
2442: sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2443: {
2444: return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2445: }
2446:
2447:
2448: int
2449: sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2450: {
2451: return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2452: }
1.211 djm 2453: #endif /* WITH_OPENSSL */
1.201 markus 2454:
2455: /* fetch data from the incoming packet */
2456:
2457: int
2458: sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2459: {
2460: return sshbuf_get(ssh->state->incoming_packet, valp, len);
2461: }
2462:
2463: int
2464: sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2465: {
2466: return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2467: }
2468:
2469: int
2470: sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2471: {
2472: return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2473: }
2474:
2475: int
2476: sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2477: {
2478: return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2479: }
2480:
2481: int
2482: sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2483: {
2484: return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2485: }
2486:
2487: int
2488: sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2489: {
2490: return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2491: }
2492:
2493: int
1.264 djm 2494: sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2495: {
2496: return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2497: }
2498:
2499: int
1.201 markus 2500: sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2501: {
2502: return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2503: }
2504:
1.211 djm 2505: #ifdef WITH_OPENSSL
1.201 markus 2506: int
2507: sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2508: {
2509: return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2510: }
2511:
2512:
2513: int
2514: sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2515: {
2516: return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2517: }
1.211 djm 2518: #endif /* WITH_OPENSSL */
1.201 markus 2519:
2520: int
2521: sshpkt_get_end(struct ssh *ssh)
2522: {
2523: if (sshbuf_len(ssh->state->incoming_packet) > 0)
2524: return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2525: return 0;
2526: }
2527:
2528: const u_char *
2529: sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2530: {
2531: if (lenp != NULL)
2532: *lenp = sshbuf_len(ssh->state->incoming_packet);
2533: return sshbuf_ptr(ssh->state->incoming_packet);
2534: }
2535:
2536: /* start a new packet */
2537:
2538: int
2539: sshpkt_start(struct ssh *ssh, u_char type)
2540: {
1.249 djm 2541: u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
1.201 markus 2542:
2543: DBG(debug("packet_start[%d]", type));
1.249 djm 2544: memset(buf, 0, sizeof(buf));
2545: buf[sizeof(buf) - 1] = type;
1.201 markus 2546: sshbuf_reset(ssh->state->outgoing_packet);
1.249 djm 2547: return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
1.201 markus 2548: }
2549:
1.242 markus 2550: static int
2551: ssh_packet_send_mux(struct ssh *ssh)
2552: {
2553: struct session_state *state = ssh->state;
2554: u_char type, *cp;
2555: size_t len;
2556: int r;
2557:
2558: if (ssh->kex)
2559: return SSH_ERR_INTERNAL_ERROR;
2560: len = sshbuf_len(state->outgoing_packet);
2561: if (len < 6)
2562: return SSH_ERR_INTERNAL_ERROR;
2563: cp = sshbuf_mutable_ptr(state->outgoing_packet);
2564: type = cp[5];
2565: if (ssh_packet_log_type(type))
2566: debug3("%s: type %u", __func__, type);
2567: /* drop everything, but the connection protocol */
2568: if (type >= SSH2_MSG_CONNECTION_MIN &&
2569: type <= SSH2_MSG_CONNECTION_MAX) {
2570: POKE_U32(cp, len - 4);
2571: if ((r = sshbuf_putb(state->output,
2572: state->outgoing_packet)) != 0)
2573: return r;
2574: /* sshbuf_dump(state->output, stderr); */
2575: }
2576: sshbuf_reset(state->outgoing_packet);
1.264 djm 2577: return 0;
2578: }
2579:
2580: /*
2581: * 9.2. Ignored Data Message
2582: *
2583: * byte SSH_MSG_IGNORE
2584: * string data
2585: *
2586: * All implementations MUST understand (and ignore) this message at any
2587: * time (after receiving the protocol version). No implementation is
2588: * required to send them. This message can be used as an additional
2589: * protection measure against advanced traffic analysis techniques.
2590: */
2591: int
2592: sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2593: {
2594: u_int32_t rnd = 0;
2595: int r;
2596: u_int i;
2597:
2598: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2599: (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2600: return r;
2601: for (i = 0; i < nbytes; i++) {
2602: if (i % 4 == 0)
2603: rnd = arc4random();
2604: if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2605: return r;
2606: rnd >>= 8;
2607: }
1.242 markus 2608: return 0;
2609: }
2610:
1.201 markus 2611: /* send it */
2612:
2613: int
2614: sshpkt_send(struct ssh *ssh)
2615: {
1.242 markus 2616: if (ssh->state && ssh->state->mux)
2617: return ssh_packet_send_mux(ssh);
1.249 djm 2618: return ssh_packet_send2(ssh);
1.201 markus 2619: }
2620:
2621: int
2622: sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2623: {
2624: char buf[1024];
2625: va_list args;
2626: int r;
2627:
2628: va_start(args, fmt);
2629: vsnprintf(buf, sizeof(buf), fmt, args);
2630: va_end(args);
2631:
1.249 djm 2632: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2633: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2634: (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2635: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2636: (r = sshpkt_send(ssh)) != 0)
2637: return r;
1.201 markus 2638: return 0;
2639: }
2640:
2641: /* roundup current message to pad bytes */
2642: int
2643: sshpkt_add_padding(struct ssh *ssh, u_char pad)
2644: {
2645: ssh->state->extra_pad = pad;
2646: return 0;
1.1 deraadt 2647: }
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