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[tripe] / tripe.h
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410c8acf 1/* -*-c-*-
2 *
110d564e 3 * $Id: tripe.h,v 1.14 2003/04/06 10:36:33 mdw Exp $
410c8acf 4 *
5 * Main header file for TrIPE
6 *
7 * (c) 2001 Straylight/Edgeware
8 */
9
10/*----- Licensing notice --------------------------------------------------*
11 *
12 * This file is part of Trivial IP Encryption (TrIPE).
13 *
14 * TrIPE is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * TrIPE is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with TrIPE; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 */
28
29/*----- Revision history --------------------------------------------------*
30 *
31 * $Log: tripe.h,v $
110d564e 32 * Revision 1.14 2003/04/06 10:36:33 mdw
33 * Rearrange so as not to include Linux headers unless we need to.
34 *
9466fafa 35 * Revision 1.13 2003/04/06 10:26:35 mdw
36 * Report peer name on decrypt errors.
37 *
37075862 38 * Revision 1.12 2003/04/06 10:25:17 mdw
39 * Support Linux TUN/TAP device. Fix some bugs.
40 *
17f0adc1 41 * Revision 1.11 2002/01/13 14:57:42 mdw
42 * Fix crap typo.
43 *
1d27afe6 44 * Revision 1.10 2002/01/13 14:54:58 mdw
45 * Provide MGF macros.
46 *
00e64b67 47 * Revision 1.9 2001/06/22 19:40:36 mdw
48 * Support expiry of other peers' public keys.
49 *
aeeb5611 50 * Revision 1.8 2001/06/19 22:10:57 mdw
51 * Some more constants for the algorithms. Document the packet format
52 * change for non-malleability. Moved @buf@ definitions to separate header
53 * file.
54 *
52307fee 55 * Revision 1.7 2001/03/03 12:07:08 mdw
56 * Rename word get and put functions now that there's 16-bit support.
57 *
fd3cf232 58 * Revision 1.6 2001/02/19 19:11:09 mdw
59 * Output buffering on admin connections.
60 *
832a2ab6 61 * Revision 1.5 2001/02/16 21:41:43 mdw
62 * Major changes. See source files for details.
63 *
1484d822 64 * Revision 1.4 2001/02/05 19:56:37 mdw
65 * Sequence number protection, and BSD tunnels.
66 *
73189848 67 * Revision 1.3 2001/02/04 01:17:55 mdw
68 * Create a configuration header file to tidy up command lines.
69 *
8d0c7a83 70 * Revision 1.2 2001/02/03 22:40:29 mdw
71 * Put timer information into the entropy pool when packets are received
72 * and on similar events. Reseed the generator on the interval timer.
73 *
410c8acf 74 * Revision 1.1 2001/02/03 20:26:37 mdw
75 * Initial checkin.
76 *
77 */
78
79#ifndef TRIPE_H
80#define TRIPE_H
81
82#ifdef __cplusplus
83 extern "C" {
84#endif
85
86/*----- Header files ------------------------------------------------------*/
87
73189848 88#include "config.h"
89
410c8acf 90#include <assert.h>
91#include <ctype.h>
92#include <errno.h>
93#include <signal.h>
94#include <stdarg.h>
95#include <stddef.h>
96#include <stdio.h>
97#include <stdlib.h>
98#include <string.h>
99#include <time.h>
100
101#include <sys/types.h>
102#include <sys/time.h>
103#include <unistd.h>
104#include <fcntl.h>
105#include <sys/stat.h>
106
107#include <sys/socket.h>
108#include <sys/un.h>
109#include <netinet/in.h>
110#include <arpa/inet.h>
111#include <netdb.h>
112
113#include <pwd.h>
114#include <grp.h>
115
116#include <mLib/alloc.h>
117#include <mLib/arena.h>
118#include <mLib/bres.h>
119#include <mLib/dstr.h>
120#include <mLib/env.h>
121#include <mLib/fdflags.h>
122#include <mLib/fwatch.h>
123#include <mLib/mdwopt.h>
124#include <mLib/quis.h>
125#include <mLib/report.h>
126#include <mLib/sel.h>
127#include <mLib/selbuf.h>
128#include <mLib/sig.h>
129#include <mLib/str.h>
130#include <mLib/sub.h>
131#include <mLib/trace.h>
132
133#include <catacomb/gcipher.h>
134#include <catacomb/gmac.h>
135#include <catacomb/grand.h>
136#include <catacomb/key.h>
137#include <catacomb/paranoia.h>
138
410c8acf 139#include <catacomb/noise.h>
140#include <catacomb/rand.h>
410c8acf 141
142#include <catacomb/mp.h>
143#include <catacomb/mpmont.h>
144#include <catacomb/mprand.h>
145#include <catacomb/dh.h>
146
aeeb5611 147#include "buf.h"
410c8acf 148#include "util.h"
149
150#undef sun
151
152/*----- Magic numbers -----------------------------------------------------*/
153
154/* --- Tunnel types --- */
155
156#define TUN_NOTDEF 0
157#define TUN_UNET 1
158#define TUN_BSD 2
37075862 159#define TUN_LINUX 3
410c8acf 160
161/* --- Trace flags --- */
162
163#define T_TUNNEL 1u
164#define T_PEER 2u
165#define T_PACKET 4u
166#define T_ADMIN 8u
167#define T_CRYPTO 16u
168#define T_KEYSET 32u
169#define T_KEYEXCH 64u
170#define T_KEYMGMT 128u
171
172#define T_ALL 255u
173
174/* --- Units --- */
175
176#define SEC(n) (n##u)
177#define MIN(n) (n##u * 60u)
178#define MEG(n) (n##ul * 1024ul * 1024ul)
179
180/* --- Other things --- */
181
182#define PKBUFSZ 65536
183
184/*----- TrIPE protocol ----------------------------------------------------*/
185
832a2ab6 186/* --- TrIPE message format --- *
410c8acf 187 *
832a2ab6 188 * A packet begins with a single-byte message type. The top four bits are a
189 * category code used to send the message to the right general place in the
190 * code; the bottom bits identify the actual message type.
410c8acf 191 */
192
832a2ab6 193#define MSG_CATMASK 0xf0
194#define MSG_TYPEMASK 0x0f
410c8acf 195
832a2ab6 196/* --- Encrypted message packets --- *
197 *
198 * Messages of category @MSG_PACKET@ contain encrypted network packets. The
199 * message content is a symmetric-encrypted block (see below). Reception of
200 * a packet encrypted under a new key implicitly permits that key to be used
201 * to send further packets.
202 *
203 * The only packet type accepted is zero.
204 *
205 * Packets may be encrypted under any live keyset, but should use the most
206 * recent one.
410c8acf 207 */
208
832a2ab6 209#define MSG_PACKET 0x00
210
211/* --- Key exchange packets --- */
212
213#define MSG_KEYEXCH 0x10
214
215#define KX_PRECHAL 0u
216#define KX_COOKIE 1u
217#define KX_CHAL 2u
218#define KX_REPLY 3u
219#define KX_SWITCH 4u
220#define KX_SWITCHOK 5u
221#define KX_NMSG 6u
410c8acf 222
832a2ab6 223/* --- Symmetric encryption and keysets --- *
224 *
aeeb5611 225 * Packets consist of an 80-bit MAC, a 32-bit sequence number, and the
832a2ab6 226 * encrypted payload.
227 *
832a2ab6 228 * The plaintext is encrypted using Blowfish in CBC mode with ciphertext
229 * stealing (as described in [Schneier]. The initialization vector is
aeeb5611 230 * selected randomly, and prepended to the actual ciphertext.
231 *
232 * The MAC is computed using the HMAC construction with RIPEMD160 over the
17f0adc1 233 * sequence number and the ciphertext (with IV); the first 80 bits of the
aeeb5611 234 * output are used. (This is the minimum allowed by the draft FIPS for HMAC,
235 * and the recommended truncation.)
832a2ab6 236 *
237 * A keyset consists of
238 *
239 * * an integrity (MAC) key;
240 * * a confidentiality (encryption) key; and
241 * * a sequence numbering space
242 *
243 * in each direction. The packets sent by a host encrypted under a
244 * particular keyset are assigned consecutive sequence numbers starting from
245 * zero. The receiving host must ensure that it only accepts each packet at
246 * most once. It should maintain a window of sequence numbers: packets with
247 * numbers beyond the end of the window are accepted and cause the window to
248 * be advanced; packets with numbers before the start of the window are
249 * rejected; packets with numbers which appear within the window are accepted
250 * only if the number has not been seen before.
251 *
252 * When a host sends a @KX_SWITCH@ or @KX_SWITCHOK@ message, it installs the
253 * newly-negotiated keyset in a `listen-only' state: it may not send a packet
254 * encrypted under the keyset until either it has received a @KX_SWITCH@ or
255 * @KX_SWITCHOK@ message, or a @MSG_PACKET@ encrypted under the keyset, from
256 * its peer.
410c8acf 257 */
258
832a2ab6 259/*----- Cipher selections -------------------------------------------------*/
260
261#include <catacomb/blowfish.h>
262#include <catacomb/blowfish-cbc.h>
1d27afe6 263#include <catacomb/blowfish-counter.h>
832a2ab6 264#include <catacomb/rmd160.h>
265#include <catacomb/rmd160-hmac.h>
266
267#define CIPHER (&blowfish_cbc)
268#define MAC (&rmd160_hmac)
269
270#define HASH_CTX rmd160_ctx
271#define HASH_INIT rmd160_init
272#define HASH rmd160_hash
273#define HASH_STRING(c, s) HASH((c), s, sizeof(s))
274#define HASH_DONE rmd160_done
275#define HASHSZ RMD160_HASHSZ
276
1d27afe6 277#define MGF_CTX blowfish_counterctx
278#define MGF_INIT blowfish_counterinit
279#define MGF_CRYPT blowfish_counterencrypt
280
aeeb5611 281#define SEQSZ 4
282#define IVSZ BLOWFISH_BLKSZ
283#define MACSZ 10
410c8acf 284
aeeb5611 285/*----- Data structures ---------------------------------------------------*/
410c8acf 286
287/* --- Socket addresses --- *
288 *
289 * A magic union of supported socket addresses.
290 */
291
292typedef union addr {
293 struct sockaddr sa;
294 struct sockaddr_in sin;
295} addr;
296
297/* --- A symmetric keyset --- *
298 *
299 * A keyset contains a set of symmetric keys for encrypting and decrypting
300 * packets. Keysets are stored in a list, sorted in reverse order of
301 * creation, so that the most recent keyset (the one most likely to be used)
302 * is first.
303 *
304 * Each keyset has a time limit and a data limit. The keyset is destroyed
305 * when either it has existed for too long, or it has been used to encrypt
306 * too much data. New key exchanges are triggered when keys are close to
307 * expiry.
308 */
309
310typedef struct keyset {
311 struct keyset *next; /* Next active keyset in the list */
832a2ab6 312 unsigned ref; /* Reference count for keyset */
9466fafa 313 struct peer *p; /* Pointer to peer structure */
410c8acf 314 time_t t_exp; /* Expiry time for this keyset */
315 unsigned long sz_exp; /* Data limit for the keyset */
832a2ab6 316 T( unsigned seq; ) /* Sequence number for tracing */
317 unsigned f; /* Various useful flags */
318 gcipher *cin, *cout; /* Keyset ciphers for encryption */
319 gmac *min, *mout; /* Keyset MACs for integrity */
1484d822 320 uint32 oseq; /* Outbound sequence number */
321 uint32 iseq, iwin; /* Inbound sequence number */
410c8acf 322} keyset;
323
1484d822 324#define KS_SEQWINSZ 32 /* Bits in sequence number window */
325
832a2ab6 326#define KSF_LISTEN 1u /* Don't encrypt packets yet */
327#define KSF_LINK 2u /* Key is in a linked list */
328
410c8acf 329/* --- Key exchange --- *
330 *
331 * TrIPE uses the Wrestlers Protocol for its key exchange. The Wrestlers
332 * Protocol has a number of desirable features (e.g., perfect forward
333 * secrecy, and zero-knowledge authentication) which make it attractive for
334 * use in TrIPE. The Wrestlers Protocol was designed by Mark Wooding and
335 * Clive Jones.
336 */
337
832a2ab6 338#define KX_NCHAL 16u
339#define KX_THRESH 4u
340
341typedef struct kxchal {
342 struct keyexch *kx; /* Pointer back to key exchange */
343 mp *c; /* Responder's challenge */
344 mp *r; /* My reply to the challenge */
345 keyset *ks; /* Pointer to temporary keyset */
346 unsigned f; /* Various useful flags */
347 sel_timer t; /* Response timer for challenge */
348 octet hc[HASHSZ]; /* Hash of his challenge */
1d27afe6 349 mp *ck; /* The check value */
832a2ab6 350 octet hswrq_in[HASHSZ]; /* Inbound switch request message */
351 octet hswok_in[HASHSZ]; /* Inbound switch confirmation */
352 octet hswrq_out[HASHSZ]; /* Outbound switch request message */
353 octet hswok_out[HASHSZ]; /* Outbound switch confirmation */
354} kxchal;
355
410c8acf 356typedef struct keyexch {
410c8acf 357 struct peer *p; /* Pointer back to the peer */
832a2ab6 358 keyset **ks; /* Peer's list of keysets */
410c8acf 359 unsigned f; /* Various useful flags */
832a2ab6 360 unsigned s; /* Current state in exchange */
410c8acf 361 sel_timer t; /* Timer for next exchange */
362 dh_pub kpub; /* Peer's public key */
00e64b67 363 time_t texp_kpub; /* Expiry time for public key */
832a2ab6 364 mp *alpha; /* My temporary secret */
365 mp *c; /* My challenge */
366 mp *rx; /* The expected response */
367 unsigned nr; /* Number of extant responses */
410c8acf 368 time_t t_valid; /* When this exchange goes bad */
832a2ab6 369 octet hc[HASHSZ]; /* Hash of my challenge */
370 kxchal *r[KX_NCHAL]; /* Array of challenges */
410c8acf 371} keyexch;
372
373#define KXF_TIMER 1u /* Waiting for a timer to go off */
00e64b67 374#define KXF_DEAD 2u /* The key-exchanger isn't up */
375#define KXF_PUBKEY 4u /* Key exchanger has a public key */
832a2ab6 376
377enum {
378 KXS_DEAD, /* Uninitialized state (magical) */
379 KXS_CHAL, /* Main answer-challenges state */
380 KXS_COMMIT, /* Committed: send switch request */
381 KXS_SWITCH /* Switched: send confirmation */
382};
410c8acf 383
384/* --- Tunnel structure --- *
385 *
386 * Used to maintain system-specific information about the tunnel interface.
387 */
388
110d564e 389#if TUN_TYPE == TUN_LINUX
390# include <linux/if.h>
391# include <linux/if_tun.h>
392#endif
393
410c8acf 394typedef struct tunnel {
37075862 395#if TUN_TYPE == TUN_UNET
410c8acf 396 sel_file f; /* Selector for Usernet device */
397 struct peer *p; /* Pointer to my peer */
37075862 398#elif TUN_TYPE == TUN_LINUX
399 sel_file f; /* Selector for TUN/TAP device */
400 struct peer *p; /* Pointer to my peer */
401 char ifn[IFNAMSIZ]; /* Interface name buffer */
1484d822 402#elif TUN_TYPE == TUN_BSD
403 sel_file f; /* Selector for tunnel device */
404 struct peer *p; /* Pointer to my peer */
405 unsigned n; /* Number of my tunnel device */
410c8acf 406#else
407# error "No support for this tunnel type"
408#endif
409} tunnel;
410
832a2ab6 411/* --- Peer statistics --- *
412 *
413 * Contains various interesting and not-so-interesting statistics about a
414 * peer. This is updated by various parts of the code. The format of the
415 * structure isn't considered private, and @p_stats@ returns a pointer to the
416 * statistics block for a given peer.
417 */
418
419typedef struct stats {
420 unsigned long sz_in, sz_out; /* Size of all data in and out */
421 unsigned long sz_kxin, sz_kxout; /* Size of key exchange messages */
422 unsigned long sz_ipin, sz_ipout; /* Size of encapsulated IP packets */
423 time_t t_start, t_last; /* Time peer created, last recv */
424 unsigned long n_reject; /* Number of rejected packets */
425 unsigned long n_in, n_out; /* Number of packets in and out */
426 unsigned long n_kxin, n_kxout; /* Number of key exchange packets */
427 unsigned long n_ipin, n_ipout; /* Number of encrypted packets */
428} stats;
429
410c8acf 430/* --- Peer structure --- *
431 *
432 * The main structure which glues everything else together.
433 */
434
435typedef struct peer {
436 struct peer *next, *prev; /* Links to next and previous */
437 char *name; /* Name of this peer */
438 tunnel t; /* Tunnel for local packets */
439 keyset *ks; /* List head for keysets */
410c8acf 440 buf b; /* Buffer for sending packets */
441 addr peer; /* Peer socket address */
442 size_t sasz; /* Socket address size */
832a2ab6 443 stats st; /* Statistics */
444 keyexch kx; /* Key exchange protocol block */
410c8acf 445} peer;
446
447/* --- Admin structure --- */
448
fd3cf232 449#define OBUFSZ 16384u
450
451typedef struct obuf {
452 struct obuf *next; /* Next buffer in list */
453 char *p_in, *p_out; /* Pointers into the buffer */
454 char buf[OBUFSZ]; /* The actual buffer */
455} obuf;
456
410c8acf 457typedef struct admin {
458 struct admin *next, *prev; /* Links to next and previous */
fd3cf232 459 unsigned f; /* Various useful flags */
410c8acf 460#ifndef NTRACE
461 unsigned seq; /* Sequence number for tracing */
462#endif
463 char *pname; /* Peer name to create */
464 char *paddr; /* Address string to resolve */
fd3cf232 465 obuf *o_head, *o_tail; /* Output buffer list */
466 selbuf b; /* Line buffer for commands */
467 sel_file w; /* Selector for write buffering */
410c8acf 468 bres_client r; /* Background resolver task */
469 sel_timer t; /* Timer for resolver */
470 addr peer; /* Address to set */
471 size_t sasz; /* Size of the address */
472} admin;
473
fd3cf232 474#define AF_DEAD 1u /* Destroy this admin block */
475#define AF_LOCK 2u /* Don't destroy it yet */
476
410c8acf 477/*----- Global variables --------------------------------------------------*/
478
479extern sel_state sel; /* Global I/O event state */
480extern dh_priv kpriv; /* Our private key */
481extern mpmont mg; /* Montgomery context for DH group */
832a2ab6 482extern octet buf_i[PKBUFSZ], buf_o[PKBUFSZ], buf_t[PKBUFSZ];
410c8acf 483
484#ifndef NTRACE
485extern const trace_opt tr_opts[]; /* Trace options array */
486extern unsigned tr_flags; /* Trace options flags */
487#endif
488
8d0c7a83 489/*----- Other macros ------------------------------------------------------*/
490
491#define TIMER noise_timer(RAND_GLOBAL)
492
410c8acf 493/*----- Key management ----------------------------------------------------*/
494
495/* --- @km_interval@ --- *
496 *
497 * Arguments: ---
498 *
499 * Returns: Zero if OK, nonzero to force reloading of keys.
500 *
501 * Use: Called on the interval timer to perform various useful jobs.
502 */
503
504extern int km_interval(void);
505
506/* --- @km_init@ --- *
507 *
508 * Arguments: @const char *kr_priv@ = private keyring file
509 * @const char *kr_pub@ = public keyring file
510 * @const char *tag@ = tag to load
511 *
512 * Returns: ---
513 *
514 * Use: Initializes, and loads the private key.
515 */
516
517extern void km_init(const char */*kr_priv*/, const char */*kr_pub*/,
518 const char */*tag*/);
519
520/* --- @km_getpubkey@ --- *
521 *
522 * Arguments: @const char *tag@ = public key tag to load
523 * @dh_pub *kpub@ = where to put the public key
00e64b67 524 * @time_t *t_exp@ = where to put the expiry time
410c8acf 525 *
526 * Returns: Zero if OK, nonzero if it failed.
527 *
528 * Use: Fetches a public key from the keyring.
529 */
530
00e64b67 531extern int km_getpubkey(const char */*tag*/, dh_pub */*kpub*/,
532 time_t */*t_exp*/);
410c8acf 533
534/*----- Key exchange ------------------------------------------------------*/
535
536/* --- @kx_start@ --- *
537 *
538 * Arguments: @keyexch *kx@ = pointer to key exchange context
539 *
540 * Returns: ---
541 *
542 * Use: Stimulates a key exchange. If a key exchage is in progress,
543 * a new challenge is sent (unless the quiet timer forbids
544 * this); if no exchange is in progress, one is commenced.
545 */
546
547extern void kx_start(keyexch */*kx*/);
548
832a2ab6 549/* --- @kx_message@ --- *
410c8acf 550 *
551 * Arguments: @keyexch *kx@ = pointer to key exchange context
832a2ab6 552 * @unsigned msg@ = the message code
553 * @buf *b@ = pointer to buffer containing the packet
410c8acf 554 *
555 * Returns: ---
556 *
832a2ab6 557 * Use: Reads a packet containing key exchange messages and handles
558 * it.
410c8acf 559 */
560
832a2ab6 561extern void kx_message(keyexch */*kx*/, unsigned /*msg*/, buf */*b*/);
410c8acf 562
563/* --- @kx_free@ --- *
564 *
565 * Arguments: @keyexch *kx@ = pointer to key exchange context
566 *
567 * Returns: ---
568 *
569 * Use: Frees everything in a key exchange context.
570 */
571
572extern void kx_free(keyexch */*kx*/);
573
574/* --- @kx_newkeys@ --- *
575 *
576 * Arguments: @keyexch *kx@ = pointer to key exchange context
577 *
578 * Returns: ---
579 *
580 * Use: Informs the key exchange module that its keys may have
581 * changed. If fetching the new keys fails, the peer will be
582 * destroyed, we log messages and struggle along with the old
583 * keys.
584 */
585
586extern void kx_newkeys(keyexch */*kx*/);
587
588/* --- @kx_init@ --- *
589 *
590 * Arguments: @keyexch *kx@ = pointer to key exchange context
591 * @peer *p@ = pointer to peer context
592 * @keyset **ks@ = pointer to keyset list
593 *
594 * Returns: Zero if OK, nonzero if it failed.
595 *
596 * Use: Initializes a key exchange module. The module currently
597 * contains no keys, and will attempt to initiate a key
598 * exchange.
599 */
600
601extern int kx_init(keyexch */*kx*/, peer */*p*/, keyset **/*ks*/);
602
603/*----- Keysets and symmetric cryptography --------------------------------*/
604
832a2ab6 605/* --- @ks_drop@ --- *
606 *
607 * Arguments: @keyset *ks@ = pointer to a keyset
608 *
609 * Returns: ---
610 *
611 * Use: Decrements a keyset's reference counter. If the counter hits
612 * zero, the keyset is freed.
613 */
614
615extern void ks_drop(keyset */*ks*/);
616
617/* --- @ks_gen@ --- *
618 *
619 * Arguments: @const void *k@ = pointer to key material
620 * @size_t x, y, z@ = offsets into key material (see below)
9466fafa 621 * @peer *p@ = pointer to peer information
832a2ab6 622 *
623 * Returns: A pointer to the new keyset.
624 *
625 * Use: Derives a new keyset from the given key material. The
626 * offsets @x@, @y@ and @z@ separate the key material into three
627 * parts. Between the @k@ and @k + x@ is `my' contribution to
628 * the key material; between @k + x@ and @k + y@ is `your'
629 * contribution; and between @k + y@ and @k + z@ is a shared
630 * value we made together. These are used to construct two
631 * pairs of symmetric keys. Each pair consists of an encryption
632 * key and a message authentication key. One pair is used for
633 * outgoing messages, the other for incoming messages.
634 *
635 * The new key is marked so that it won't be selected for output
636 * by @ksl_encrypt@. You can still encrypt data with it by
637 * calling @ks_encrypt@ directly.
638 */
639
640extern keyset *ks_gen(const void */*k*/,
9466fafa 641 size_t /*x*/, size_t /*y*/, size_t /*z*/,
642 peer */*p*/);
832a2ab6 643
644/* --- @ks_tregen@ --- *
645 *
646 * Arguments: @keyset *ks@ = pointer to a keyset
647 *
648 * Returns: The time at which moves ought to be made to replace this key.
649 */
650
651extern time_t ks_tregen(keyset */*ks*/);
652
653/* --- @ks_activate@ --- *
654 *
655 * Arguments: @keyset *ks@ = pointer to a keyset
656 *
657 * Returns: ---
658 *
659 * Use: Activates a keyset, so that it can be used for encrypting
660 * outgoing messages.
661 */
662
663extern void ks_activate(keyset */*ks*/);
664
665/* --- @ks_encrypt@ --- *
666 *
667 * Arguments: @keyset *ks@ = pointer to a keyset
668 * @buf *b@ = pointer to input buffer
669 * @buf *bb@ = pointer to output buffer
670 *
671 * Returns: Zero if OK, nonzero if the key needs replacing. If the
672 * encryption failed, the output buffer is broken and zero is
673 * returned.
674 *
675 * Use: Encrypts a block of data using the key. Note that the `key
676 * ought to be replaced' notification is only ever given once
677 * for each key. Also note that this call forces a keyset to be
678 * used even if it's marked as not for data output.
679 */
680
681extern int ks_encrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/);
682
683/* --- @ks_decrypt@ --- *
684 *
685 * Arguments: @keyset *ks@ = pointer to a keyset
686 * @buf *b@ = pointer to an input buffer
687 * @buf *bb@ = pointer to an output buffer
688 *
689 * Returns: Zero on success, or nonzero if there was some problem.
690 *
691 * Use: Attempts to decrypt a message using a given key. Note that
692 * requesting decryption with a key directly won't clear a
693 * marking that it's not for encryption.
694 */
695
696extern int ks_decrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/);
697
698/* --- @ksl_free@ --- *
410c8acf 699 *
700 * Arguments: @keyset **ksroot@ = pointer to keyset list head
701 *
702 * Returns: ---
703 *
832a2ab6 704 * Use: Frees (releases references to) all of the keys in a keyset.
410c8acf 705 */
706
832a2ab6 707extern void ksl_free(keyset **/*ksroot*/);
410c8acf 708
832a2ab6 709/* --- @ksl_link@ --- *
410c8acf 710 *
711 * Arguments: @keyset **ksroot@ = pointer to keyset list head
832a2ab6 712 * @keyset *ks@ = pointer to a keyset
410c8acf 713 *
714 * Returns: ---
715 *
832a2ab6 716 * Use: Links a keyset into a list. A keyset can only be on one list
717 * at a time. Bad things happen otherwise.
410c8acf 718 */
719
832a2ab6 720extern void ksl_link(keyset **/*ksroot*/, keyset */*ks*/);
410c8acf 721
832a2ab6 722/* --- @ksl_prune@ --- *
410c8acf 723 *
724 * Arguments: @keyset **ksroot@ = pointer to keyset list head
410c8acf 725 *
832a2ab6 726 * Returns: ---
410c8acf 727 *
832a2ab6 728 * Use: Prunes the keyset list by removing keys which mustn't be used
729 * any more.
410c8acf 730 */
731
832a2ab6 732extern void ksl_prune(keyset **/*ksroot*/);
410c8acf 733
832a2ab6 734/* --- @ksl_encrypt@ --- *
410c8acf 735 *
736 * Arguments: @keyset **ksroot@ = pointer to keyset list head
737 * @buf *b@ = pointer to input buffer
738 * @buf *bb@ = pointer to output buffer
739 *
740 * Returns: Nonzero if a new key is needed.
741 *
742 * Use: Encrypts a packet.
743 */
744
832a2ab6 745extern int ksl_encrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/);
410c8acf 746
832a2ab6 747/* --- @ksl_decrypt@ --- *
410c8acf 748 *
749 * Arguments: @keyset **ksroot@ = pointer to keyset list head
750 * @buf *b@ = pointer to input buffer
751 * @buf *bb@ = pointer to output buffer
752 *
753 * Returns: Nonzero if the packet couldn't be decrypted.
754 *
755 * Use: Decrypts a packet.
756 */
757
832a2ab6 758extern int ksl_decrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/);
410c8acf 759
760/*----- Administration interface ------------------------------------------*/
761
762/* --- @a_warn@ --- *
763 *
764 * Arguments: @const char *fmt@ = pointer to format string
765 * @...@ = other arguments
766 *
767 * Returns: ---
768 *
769 * Use: Informs all admin connections of a warning.
770 */
771
772extern void a_warn(const char */*fmt*/, ...);
773
774/* --- @a_create@ --- *
775 *
776 * Arguments: @int fd_in, fd_out@ = file descriptors to use
777 *
778 * Returns: ---
779 *
780 * Use: Creates a new admin connection.
781 */
782
783extern void a_create(int /*fd_in*/, int /*fd_out*/);
784
785/* --- @a_quit@ --- *
786 *
787 * Arguments: ---
788 *
789 * Returns: ---
790 *
791 * Use: Shuts things down nicely.
792 */
793
794extern void a_quit(void);
795
796/* --- @a_daemon@ --- *
797 *
798 * Arguments: ---
799 *
800 * Returns: ---
801 *
802 * Use: Informs the admin module that it's a daemon.
803 */
804
805extern void a_daemon(void);
806
807/* --- @a_init@ --- *
808 *
809 * Arguments: @const char *sock@ = socket name to create
810 *
811 * Returns: ---
812 *
813 * Use: Creates the admin listening socket.
814 */
815
816extern void a_init(const char */*sock*/);
817
818/*----- Peer management ---------------------------------------------------*/
819
820/* --- @p_txstart@ --- *
821 *
822 * Arguments: @peer *p@ = pointer to peer block
823 * @unsigned msg@ = message type code
824 *
825 * Returns: A pointer to a buffer to write to.
826 *
827 * Use: Starts sending to a peer. Only one send can happen at a
828 * time.
829 */
830
831extern buf *p_txstart(peer */*p*/, unsigned /*msg*/);
832
833/* --- @p_txend@ --- *
834 *
835 * Arguments: @peer *p@ = pointer to peer block
836 *
837 * Returns: ---
838 *
839 * Use: Sends a packet to the peer.
840 */
841
842extern void p_txend(peer */*p*/);
843
844/* --- @p_tun@ --- *
845 *
846 * Arguments: @peer *p@ = pointer to peer block
847 * @buf *b@ = buffer containing incoming packet
848 *
849 * Returns: ---
850 *
851 * Use: Handles a packet which needs to be sent to a peer.
852 */
853
854extern void p_tun(peer */*p*/, buf */*b*/);
855
856/* --- @p_interval@ --- *
857 *
858 * Arguments: ---
859 *
860 * Returns: ---
861 *
862 * Use: Called periodically to do tidying.
863 */
864
865extern void p_interval(void);
866
832a2ab6 867/* --- @p_stats@ --- *
868 *
869 * Arguments: @peer *p@ = pointer to a peer block
870 *
871 * Returns: A pointer to the peer's statistics.
872 */
873
874extern stats *p_stats(peer */*p*/);
875
410c8acf 876/* --- @p_ifname@ --- *
877 *
878 * Arguments: @peer *p@ = pointer to a peer block
879 *
880 * Returns: A pointer to the peer's interface name.
881 */
882
883extern const char *p_ifname(peer */*p*/);
884
885/* --- @p_addr@ --- *
886 *
887 * Arguments: @peer *p@ = pointer to a peer block
888 *
889 * Returns: A pointer to the peer's address.
890 */
891
892extern const addr *p_addr(peer */*p*/);
893
894/* --- @p_init@ --- *
895 *
896 * Arguments: @unsigned port@ = port number to listen to
897 *
898 * Returns: ---
899 *
900 * Use: Initializes the peer system; creates the socket.
901 */
902
903extern void p_init(unsigned /*port*/);
904
905/* --- @p_port@ --- *
906 *
907 * Arguments: ---
908 *
909 * Returns: Port number used for socket.
910 */
911
912unsigned p_port(void);
913
914/* --- @p_create@ --- *
915 *
916 * Arguments: @const char *name@ = name for this peer
917 * @struct sockaddr *sa@ = socket address of peer
918 * @size_t sz@ = size of socket address
919 *
920 * Returns: Pointer to the peer block, or null if it failed.
921 *
922 * Use: Creates a new named peer block. No peer is actually attached
923 * by this point.
924 */
925
926extern peer *p_create(const char */*name*/,
927 struct sockaddr */*sa*/, size_t /*sz*/);
928
929/* --- @p_name@ --- *
930 *
931 * Arguments: @peer *p@ = pointer to a peer block
932 *
933 * Returns: A pointer to the peer's name.
934 */
935
936extern const char *p_name(peer */*p*/);
937
938/* --- @p_find@ --- *
939 *
940 * Arguments: @const char *name@ = name to look up
941 *
942 * Returns: Pointer to the peer block, or null if not found.
943 *
944 * Use: Finds a peer by name.
945 */
946
947extern peer *p_find(const char */*name*/);
948
949/* --- @p_destroy@ --- *
950 *
951 * Arguments: @peer *p@ = pointer to a peer
952 *
953 * Returns: ---
954 *
955 * Use: Destroys a peer.
956 */
957
958extern void p_destroy(peer */*p*/);
959
960/* --- @p_first@, @p_next@ --- *
961 *
962 * Arguments: @peer *p@ = a peer block
963 *
964 * Returns: @peer_first@ returns the first peer in some ordering;
965 * @peer_next@ returns the peer following a given one in the
966 * same ordering. Null is returned for the end of the list.
967 */
968
969extern peer *p_first(void);
970extern peer *p_next(peer */*p*/);
971
972/*----- Tunnel interface --------------------------------------------------*/
973
974/* --- @tun_init@ --- *
975 *
976 * Arguments: ---
977 *
978 * Returns: ---
979 *
980 * Use: Initializes the tunneling system. Maybe this will require
981 * opening file descriptors or something.
982 */
983
984extern void tun_init(void);
985
986/* --- @tun_create@ --- *
987 *
988 * Arguments: @tunnel *t@ = pointer to tunnel block
989 * @peer *p@ = pointer to peer block
990 *
991 * Returns: Zero if it worked, nonzero on failure.
992 *
993 * Use: Initializes a new tunnel.
994 */
995
996extern int tun_create(tunnel */*t*/, peer */*p*/);
997
998/* --- @tun_ifname@ --- *
999 *
1000 * Arguments: @tunnel *t@ = pointer to tunnel block
1001 *
1002 * Returns: A pointer to the tunnel's interface name.
1003 */
1004
1005extern const char *tun_ifname(tunnel */*t*/);
1006
1007/* --- @tun_inject@ --- *
1008 *
1009 * Arguments: @tunnel *t@ = pointer to tunnel block
1010 * @buf *b@ = buffer to send
1011 *
1012 * Returns: ---
1013 *
1014 * Use: Injects a packet into the local network stack.
1015 */
1016
1017extern void tun_inject(tunnel */*t*/, buf */*b*/);
1018
1019/* --- @tun_destroy@ --- *
1020 *
1021 * Arguments: @tunnel *t@ = pointer to tunnel block
1022 *
1023 * Returns: ---
1024 *
1025 * Use: Destroys a tunnel.
1026 */
1027
1028extern void tun_destroy(tunnel */*t*/);
1029
410c8acf 1030/*----- Other handy utilities ---------------------------------------------*/
1031
1032/* --- @mpstr@ --- *
1033 *
1034 * Arguments: @mp *m@ = a multiprecision integer
1035 *
1036 * Returns: A pointer to the integer's textual representation.
1037 *
1038 * Use: Converts a multiprecision integer to a string. Corrupts
832a2ab6 1039 * @buf_t@.
410c8acf 1040 */
1041
1042extern const char *mpstr(mp */*m*/);
1043
832a2ab6 1044/* --- @timestr@ --- *
1045 *
1046 * Arguments: @time_t t@ = a time to convert
1047 *
1048 * Returns: A pointer to a textual representation of the time.
1049 *
1050 * Use: Converts a time to a textual representation. Corrupts
1051 * @buf_t@.
1052 */
1053
1054extern const char *timestr(time_t /*t*/);
1055
410c8acf 1056/*----- That's all, folks -------------------------------------------------*/
1057
1058#ifdef __cplusplus
1059 }
1060#endif
1061
1062#endif