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[tripe] / tripe.h
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410c8acf 1/* -*-c-*-
2 *
832a2ab6 3 * $Id: tripe.h,v 1.5 2001/02/16 21:41:43 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 $
832a2ab6 32 * Revision 1.5 2001/02/16 21:41:43 mdw
33 * Major changes. See source files for details.
34 *
1484d822 35 * Revision 1.4 2001/02/05 19:56:37 mdw
36 * Sequence number protection, and BSD tunnels.
37 *
73189848 38 * Revision 1.3 2001/02/04 01:17:55 mdw
39 * Create a configuration header file to tidy up command lines.
40 *
8d0c7a83 41 * Revision 1.2 2001/02/03 22:40:29 mdw
42 * Put timer information into the entropy pool when packets are received
43 * and on similar events. Reseed the generator on the interval timer.
44 *
410c8acf 45 * Revision 1.1 2001/02/03 20:26:37 mdw
46 * Initial checkin.
47 *
48 */
49
50#ifndef TRIPE_H
51#define TRIPE_H
52
53#ifdef __cplusplus
54 extern "C" {
55#endif
56
57/*----- Header files ------------------------------------------------------*/
58
73189848 59#include "config.h"
60
410c8acf 61#include <assert.h>
62#include <ctype.h>
63#include <errno.h>
64#include <signal.h>
65#include <stdarg.h>
66#include <stddef.h>
67#include <stdio.h>
68#include <stdlib.h>
69#include <string.h>
70#include <time.h>
71
72#include <sys/types.h>
73#include <sys/time.h>
74#include <unistd.h>
75#include <fcntl.h>
76#include <sys/stat.h>
77
78#include <sys/socket.h>
79#include <sys/un.h>
80#include <netinet/in.h>
81#include <arpa/inet.h>
82#include <netdb.h>
83
84#include <pwd.h>
85#include <grp.h>
86
87#include <mLib/alloc.h>
88#include <mLib/arena.h>
89#include <mLib/bres.h>
90#include <mLib/dstr.h>
91#include <mLib/env.h>
92#include <mLib/fdflags.h>
93#include <mLib/fwatch.h>
94#include <mLib/mdwopt.h>
95#include <mLib/quis.h>
96#include <mLib/report.h>
97#include <mLib/sel.h>
98#include <mLib/selbuf.h>
99#include <mLib/sig.h>
100#include <mLib/str.h>
101#include <mLib/sub.h>
102#include <mLib/trace.h>
103
104#include <catacomb/gcipher.h>
105#include <catacomb/gmac.h>
106#include <catacomb/grand.h>
107#include <catacomb/key.h>
108#include <catacomb/paranoia.h>
109
410c8acf 110#include <catacomb/noise.h>
111#include <catacomb/rand.h>
410c8acf 112
113#include <catacomb/mp.h>
114#include <catacomb/mpmont.h>
115#include <catacomb/mprand.h>
116#include <catacomb/dh.h>
117
118#include "util.h"
119
120#undef sun
121
122/*----- Magic numbers -----------------------------------------------------*/
123
124/* --- Tunnel types --- */
125
126#define TUN_NOTDEF 0
127#define TUN_UNET 1
128#define TUN_BSD 2
129
130/* --- Trace flags --- */
131
132#define T_TUNNEL 1u
133#define T_PEER 2u
134#define T_PACKET 4u
135#define T_ADMIN 8u
136#define T_CRYPTO 16u
137#define T_KEYSET 32u
138#define T_KEYEXCH 64u
139#define T_KEYMGMT 128u
140
141#define T_ALL 255u
142
143/* --- Units --- */
144
145#define SEC(n) (n##u)
146#define MIN(n) (n##u * 60u)
147#define MEG(n) (n##ul * 1024ul * 1024ul)
148
149/* --- Other things --- */
150
151#define PKBUFSZ 65536
152
153/*----- TrIPE protocol ----------------------------------------------------*/
154
832a2ab6 155/* --- TrIPE message format --- *
410c8acf 156 *
832a2ab6 157 * A packet begins with a single-byte message type. The top four bits are a
158 * category code used to send the message to the right general place in the
159 * code; the bottom bits identify the actual message type.
410c8acf 160 */
161
832a2ab6 162#define MSG_CATMASK 0xf0
163#define MSG_TYPEMASK 0x0f
410c8acf 164
832a2ab6 165/* --- Encrypted message packets --- *
166 *
167 * Messages of category @MSG_PACKET@ contain encrypted network packets. The
168 * message content is a symmetric-encrypted block (see below). Reception of
169 * a packet encrypted under a new key implicitly permits that key to be used
170 * to send further packets.
171 *
172 * The only packet type accepted is zero.
173 *
174 * Packets may be encrypted under any live keyset, but should use the most
175 * recent one.
410c8acf 176 */
177
832a2ab6 178#define MSG_PACKET 0x00
179
180/* --- Key exchange packets --- */
181
182#define MSG_KEYEXCH 0x10
183
184#define KX_PRECHAL 0u
185#define KX_COOKIE 1u
186#define KX_CHAL 2u
187#define KX_REPLY 3u
188#define KX_SWITCH 4u
189#define KX_SWITCHOK 5u
190#define KX_NMSG 6u
410c8acf 191
832a2ab6 192/* --- Symmetric encryption and keysets --- *
193 *
194 * Packets consist of a 64-bit MAC, a 32-bit sequence number, and the
195 * encrypted payload.
196 *
197 * The MAC is computed using the HMAC construction with RIPEMD160 over the
198 * sequence number and the original packet plaintext; the first 64 bits of
199 * the output are used.
200 *
201 * The plaintext is encrypted using Blowfish in CBC mode with ciphertext
202 * stealing (as described in [Schneier]. The initialization vector is
203 * precisely the 64-bit MAC computed previously.
204 *
205 * A keyset consists of
206 *
207 * * an integrity (MAC) key;
208 * * a confidentiality (encryption) key; and
209 * * a sequence numbering space
210 *
211 * in each direction. The packets sent by a host encrypted under a
212 * particular keyset are assigned consecutive sequence numbers starting from
213 * zero. The receiving host must ensure that it only accepts each packet at
214 * most once. It should maintain a window of sequence numbers: packets with
215 * numbers beyond the end of the window are accepted and cause the window to
216 * be advanced; packets with numbers before the start of the window are
217 * rejected; packets with numbers which appear within the window are accepted
218 * only if the number has not been seen before.
219 *
220 * When a host sends a @KX_SWITCH@ or @KX_SWITCHOK@ message, it installs the
221 * newly-negotiated keyset in a `listen-only' state: it may not send a packet
222 * encrypted under the keyset until either it has received a @KX_SWITCH@ or
223 * @KX_SWITCHOK@ message, or a @MSG_PACKET@ encrypted under the keyset, from
224 * its peer.
410c8acf 225 */
226
832a2ab6 227/*----- Cipher selections -------------------------------------------------*/
228
229#include <catacomb/blowfish.h>
230#include <catacomb/blowfish-cbc.h>
231#include <catacomb/rmd160.h>
232#include <catacomb/rmd160-hmac.h>
233
234#define CIPHER (&blowfish_cbc)
235#define MAC (&rmd160_hmac)
236
237#define HASH_CTX rmd160_ctx
238#define HASH_INIT rmd160_init
239#define HASH rmd160_hash
240#define HASH_STRING(c, s) HASH((c), s, sizeof(s))
241#define HASH_DONE rmd160_done
242#define HASHSZ RMD160_HASHSZ
243
410c8acf 244/*----- Data structures ---------------------------------------------------*/
245
246/* --- Buffers --- *
247 *
248 * Buffers provide a simple stream-like interface for building and parsing
249 * packets.
250 */
251
252typedef struct buf {
253 octet *base, *p, *limit; /* Pointers to the buffer */
254 unsigned f; /* Various flags */
255} buf;
256
257#define BF_BROKEN 1u /* Buffer is broken */
258
259/* --- Socket addresses --- *
260 *
261 * A magic union of supported socket addresses.
262 */
263
264typedef union addr {
265 struct sockaddr sa;
266 struct sockaddr_in sin;
267} addr;
268
269/* --- A symmetric keyset --- *
270 *
271 * A keyset contains a set of symmetric keys for encrypting and decrypting
272 * packets. Keysets are stored in a list, sorted in reverse order of
273 * creation, so that the most recent keyset (the one most likely to be used)
274 * is first.
275 *
276 * Each keyset has a time limit and a data limit. The keyset is destroyed
277 * when either it has existed for too long, or it has been used to encrypt
278 * too much data. New key exchanges are triggered when keys are close to
279 * expiry.
280 */
281
282typedef struct keyset {
283 struct keyset *next; /* Next active keyset in the list */
832a2ab6 284 unsigned ref; /* Reference count for keyset */
410c8acf 285 time_t t_exp; /* Expiry time for this keyset */
286 unsigned long sz_exp; /* Data limit for the keyset */
832a2ab6 287 T( unsigned seq; ) /* Sequence number for tracing */
288 unsigned f; /* Various useful flags */
289 gcipher *cin, *cout; /* Keyset ciphers for encryption */
290 gmac *min, *mout; /* Keyset MACs for integrity */
1484d822 291 uint32 oseq; /* Outbound sequence number */
292 uint32 iseq, iwin; /* Inbound sequence number */
410c8acf 293} keyset;
294
1484d822 295#define KS_SEQWINSZ 32 /* Bits in sequence number window */
296
832a2ab6 297#define KSF_LISTEN 1u /* Don't encrypt packets yet */
298#define KSF_LINK 2u /* Key is in a linked list */
299
410c8acf 300/* --- Key exchange --- *
301 *
302 * TrIPE uses the Wrestlers Protocol for its key exchange. The Wrestlers
303 * Protocol has a number of desirable features (e.g., perfect forward
304 * secrecy, and zero-knowledge authentication) which make it attractive for
305 * use in TrIPE. The Wrestlers Protocol was designed by Mark Wooding and
306 * Clive Jones.
307 */
308
832a2ab6 309#define KX_NCHAL 16u
310#define KX_THRESH 4u
311
312typedef struct kxchal {
313 struct keyexch *kx; /* Pointer back to key exchange */
314 mp *c; /* Responder's challenge */
315 mp *r; /* My reply to the challenge */
316 keyset *ks; /* Pointer to temporary keyset */
317 unsigned f; /* Various useful flags */
318 sel_timer t; /* Response timer for challenge */
319 octet hc[HASHSZ]; /* Hash of his challenge */
320 octet hrx[HASHSZ]; /* My expected reply hash */
321 octet hswrq_in[HASHSZ]; /* Inbound switch request message */
322 octet hswok_in[HASHSZ]; /* Inbound switch confirmation */
323 octet hswrq_out[HASHSZ]; /* Outbound switch request message */
324 octet hswok_out[HASHSZ]; /* Outbound switch confirmation */
325} kxchal;
326
410c8acf 327typedef struct keyexch {
410c8acf 328 struct peer *p; /* Pointer back to the peer */
832a2ab6 329 keyset **ks; /* Peer's list of keysets */
410c8acf 330 unsigned f; /* Various useful flags */
832a2ab6 331 unsigned s; /* Current state in exchange */
410c8acf 332 sel_timer t; /* Timer for next exchange */
333 dh_pub kpub; /* Peer's public key */
832a2ab6 334 mp *alpha; /* My temporary secret */
335 mp *c; /* My challenge */
336 mp *rx; /* The expected response */
337 unsigned nr; /* Number of extant responses */
410c8acf 338 time_t t_valid; /* When this exchange goes bad */
832a2ab6 339 octet hc[HASHSZ]; /* Hash of my challenge */
340 kxchal *r[KX_NCHAL]; /* Array of challenges */
410c8acf 341} keyexch;
342
343#define KXF_TIMER 1u /* Waiting for a timer to go off */
832a2ab6 344
345enum {
346 KXS_DEAD, /* Uninitialized state (magical) */
347 KXS_CHAL, /* Main answer-challenges state */
348 KXS_COMMIT, /* Committed: send switch request */
349 KXS_SWITCH /* Switched: send confirmation */
350};
410c8acf 351
352/* --- Tunnel structure --- *
353 *
354 * Used to maintain system-specific information about the tunnel interface.
355 */
356
357typedef struct tunnel {
358#if TUN_TYPE == TUN_UNET
359 sel_file f; /* Selector for Usernet device */
360 struct peer *p; /* Pointer to my peer */
1484d822 361#elif TUN_TYPE == TUN_BSD
362 sel_file f; /* Selector for tunnel device */
363 struct peer *p; /* Pointer to my peer */
364 unsigned n; /* Number of my tunnel device */
410c8acf 365#else
366# error "No support for this tunnel type"
367#endif
368} tunnel;
369
832a2ab6 370/* --- Peer statistics --- *
371 *
372 * Contains various interesting and not-so-interesting statistics about a
373 * peer. This is updated by various parts of the code. The format of the
374 * structure isn't considered private, and @p_stats@ returns a pointer to the
375 * statistics block for a given peer.
376 */
377
378typedef struct stats {
379 unsigned long sz_in, sz_out; /* Size of all data in and out */
380 unsigned long sz_kxin, sz_kxout; /* Size of key exchange messages */
381 unsigned long sz_ipin, sz_ipout; /* Size of encapsulated IP packets */
382 time_t t_start, t_last; /* Time peer created, last recv */
383 unsigned long n_reject; /* Number of rejected packets */
384 unsigned long n_in, n_out; /* Number of packets in and out */
385 unsigned long n_kxin, n_kxout; /* Number of key exchange packets */
386 unsigned long n_ipin, n_ipout; /* Number of encrypted packets */
387} stats;
388
410c8acf 389/* --- Peer structure --- *
390 *
391 * The main structure which glues everything else together.
392 */
393
394typedef struct peer {
395 struct peer *next, *prev; /* Links to next and previous */
396 char *name; /* Name of this peer */
397 tunnel t; /* Tunnel for local packets */
398 keyset *ks; /* List head for keysets */
410c8acf 399 buf b; /* Buffer for sending packets */
400 addr peer; /* Peer socket address */
401 size_t sasz; /* Socket address size */
832a2ab6 402 stats st; /* Statistics */
403 keyexch kx; /* Key exchange protocol block */
410c8acf 404} peer;
405
406/* --- Admin structure --- */
407
408typedef struct admin {
409 struct admin *next, *prev; /* Links to next and previous */
410 selbuf b; /* Line buffer for commands */
411 int fd; /* File descriptor for output */
412#ifndef NTRACE
413 unsigned seq; /* Sequence number for tracing */
414#endif
415 char *pname; /* Peer name to create */
416 char *paddr; /* Address string to resolve */
417 bres_client r; /* Background resolver task */
418 sel_timer t; /* Timer for resolver */
419 addr peer; /* Address to set */
420 size_t sasz; /* Size of the address */
421} admin;
422
423/*----- Global variables --------------------------------------------------*/
424
425extern sel_state sel; /* Global I/O event state */
426extern dh_priv kpriv; /* Our private key */
427extern mpmont mg; /* Montgomery context for DH group */
832a2ab6 428extern octet buf_i[PKBUFSZ], buf_o[PKBUFSZ], buf_t[PKBUFSZ];
410c8acf 429
430#ifndef NTRACE
431extern const trace_opt tr_opts[]; /* Trace options array */
432extern unsigned tr_flags; /* Trace options flags */
433#endif
434
8d0c7a83 435/*----- Other macros ------------------------------------------------------*/
436
437#define TIMER noise_timer(RAND_GLOBAL)
438
410c8acf 439/*----- Key management ----------------------------------------------------*/
440
441/* --- @km_interval@ --- *
442 *
443 * Arguments: ---
444 *
445 * Returns: Zero if OK, nonzero to force reloading of keys.
446 *
447 * Use: Called on the interval timer to perform various useful jobs.
448 */
449
450extern int km_interval(void);
451
452/* --- @km_init@ --- *
453 *
454 * Arguments: @const char *kr_priv@ = private keyring file
455 * @const char *kr_pub@ = public keyring file
456 * @const char *tag@ = tag to load
457 *
458 * Returns: ---
459 *
460 * Use: Initializes, and loads the private key.
461 */
462
463extern void km_init(const char */*kr_priv*/, const char */*kr_pub*/,
464 const char */*tag*/);
465
466/* --- @km_getpubkey@ --- *
467 *
468 * Arguments: @const char *tag@ = public key tag to load
469 * @dh_pub *kpub@ = where to put the public key
470 *
471 * Returns: Zero if OK, nonzero if it failed.
472 *
473 * Use: Fetches a public key from the keyring.
474 */
475
476extern int km_getpubkey(const char */*tag*/, dh_pub */*kpub*/);
477
478/*----- Key exchange ------------------------------------------------------*/
479
480/* --- @kx_start@ --- *
481 *
482 * Arguments: @keyexch *kx@ = pointer to key exchange context
483 *
484 * Returns: ---
485 *
486 * Use: Stimulates a key exchange. If a key exchage is in progress,
487 * a new challenge is sent (unless the quiet timer forbids
488 * this); if no exchange is in progress, one is commenced.
489 */
490
491extern void kx_start(keyexch */*kx*/);
492
832a2ab6 493/* --- @kx_message@ --- *
410c8acf 494 *
495 * Arguments: @keyexch *kx@ = pointer to key exchange context
832a2ab6 496 * @unsigned msg@ = the message code
497 * @buf *b@ = pointer to buffer containing the packet
410c8acf 498 *
499 * Returns: ---
500 *
832a2ab6 501 * Use: Reads a packet containing key exchange messages and handles
502 * it.
410c8acf 503 */
504
832a2ab6 505extern void kx_message(keyexch */*kx*/, unsigned /*msg*/, buf */*b*/);
410c8acf 506
507/* --- @kx_free@ --- *
508 *
509 * Arguments: @keyexch *kx@ = pointer to key exchange context
510 *
511 * Returns: ---
512 *
513 * Use: Frees everything in a key exchange context.
514 */
515
516extern void kx_free(keyexch */*kx*/);
517
518/* --- @kx_newkeys@ --- *
519 *
520 * Arguments: @keyexch *kx@ = pointer to key exchange context
521 *
522 * Returns: ---
523 *
524 * Use: Informs the key exchange module that its keys may have
525 * changed. If fetching the new keys fails, the peer will be
526 * destroyed, we log messages and struggle along with the old
527 * keys.
528 */
529
530extern void kx_newkeys(keyexch */*kx*/);
531
532/* --- @kx_init@ --- *
533 *
534 * Arguments: @keyexch *kx@ = pointer to key exchange context
535 * @peer *p@ = pointer to peer context
536 * @keyset **ks@ = pointer to keyset list
537 *
538 * Returns: Zero if OK, nonzero if it failed.
539 *
540 * Use: Initializes a key exchange module. The module currently
541 * contains no keys, and will attempt to initiate a key
542 * exchange.
543 */
544
545extern int kx_init(keyexch */*kx*/, peer */*p*/, keyset **/*ks*/);
546
547/*----- Keysets and symmetric cryptography --------------------------------*/
548
832a2ab6 549/* --- @ks_drop@ --- *
550 *
551 * Arguments: @keyset *ks@ = pointer to a keyset
552 *
553 * Returns: ---
554 *
555 * Use: Decrements a keyset's reference counter. If the counter hits
556 * zero, the keyset is freed.
557 */
558
559extern void ks_drop(keyset */*ks*/);
560
561/* --- @ks_gen@ --- *
562 *
563 * Arguments: @const void *k@ = pointer to key material
564 * @size_t x, y, z@ = offsets into key material (see below)
565 *
566 * Returns: A pointer to the new keyset.
567 *
568 * Use: Derives a new keyset from the given key material. The
569 * offsets @x@, @y@ and @z@ separate the key material into three
570 * parts. Between the @k@ and @k + x@ is `my' contribution to
571 * the key material; between @k + x@ and @k + y@ is `your'
572 * contribution; and between @k + y@ and @k + z@ is a shared
573 * value we made together. These are used to construct two
574 * pairs of symmetric keys. Each pair consists of an encryption
575 * key and a message authentication key. One pair is used for
576 * outgoing messages, the other for incoming messages.
577 *
578 * The new key is marked so that it won't be selected for output
579 * by @ksl_encrypt@. You can still encrypt data with it by
580 * calling @ks_encrypt@ directly.
581 */
582
583extern keyset *ks_gen(const void */*k*/,
584 size_t /*x*/, size_t /*y*/, size_t /*z*/);
585
586/* --- @ks_tregen@ --- *
587 *
588 * Arguments: @keyset *ks@ = pointer to a keyset
589 *
590 * Returns: The time at which moves ought to be made to replace this key.
591 */
592
593extern time_t ks_tregen(keyset */*ks*/);
594
595/* --- @ks_activate@ --- *
596 *
597 * Arguments: @keyset *ks@ = pointer to a keyset
598 *
599 * Returns: ---
600 *
601 * Use: Activates a keyset, so that it can be used for encrypting
602 * outgoing messages.
603 */
604
605extern void ks_activate(keyset */*ks*/);
606
607/* --- @ks_encrypt@ --- *
608 *
609 * Arguments: @keyset *ks@ = pointer to a keyset
610 * @buf *b@ = pointer to input buffer
611 * @buf *bb@ = pointer to output buffer
612 *
613 * Returns: Zero if OK, nonzero if the key needs replacing. If the
614 * encryption failed, the output buffer is broken and zero is
615 * returned.
616 *
617 * Use: Encrypts a block of data using the key. Note that the `key
618 * ought to be replaced' notification is only ever given once
619 * for each key. Also note that this call forces a keyset to be
620 * used even if it's marked as not for data output.
621 */
622
623extern int ks_encrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/);
624
625/* --- @ks_decrypt@ --- *
626 *
627 * Arguments: @keyset *ks@ = pointer to a keyset
628 * @buf *b@ = pointer to an input buffer
629 * @buf *bb@ = pointer to an output buffer
630 *
631 * Returns: Zero on success, or nonzero if there was some problem.
632 *
633 * Use: Attempts to decrypt a message using a given key. Note that
634 * requesting decryption with a key directly won't clear a
635 * marking that it's not for encryption.
636 */
637
638extern int ks_decrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/);
639
640/* --- @ksl_free@ --- *
410c8acf 641 *
642 * Arguments: @keyset **ksroot@ = pointer to keyset list head
643 *
644 * Returns: ---
645 *
832a2ab6 646 * Use: Frees (releases references to) all of the keys in a keyset.
410c8acf 647 */
648
832a2ab6 649extern void ksl_free(keyset **/*ksroot*/);
410c8acf 650
832a2ab6 651/* --- @ksl_link@ --- *
410c8acf 652 *
653 * Arguments: @keyset **ksroot@ = pointer to keyset list head
832a2ab6 654 * @keyset *ks@ = pointer to a keyset
410c8acf 655 *
656 * Returns: ---
657 *
832a2ab6 658 * Use: Links a keyset into a list. A keyset can only be on one list
659 * at a time. Bad things happen otherwise.
410c8acf 660 */
661
832a2ab6 662extern void ksl_link(keyset **/*ksroot*/, keyset */*ks*/);
410c8acf 663
832a2ab6 664/* --- @ksl_prune@ --- *
410c8acf 665 *
666 * Arguments: @keyset **ksroot@ = pointer to keyset list head
410c8acf 667 *
832a2ab6 668 * Returns: ---
410c8acf 669 *
832a2ab6 670 * Use: Prunes the keyset list by removing keys which mustn't be used
671 * any more.
410c8acf 672 */
673
832a2ab6 674extern void ksl_prune(keyset **/*ksroot*/);
410c8acf 675
832a2ab6 676/* --- @ksl_encrypt@ --- *
410c8acf 677 *
678 * Arguments: @keyset **ksroot@ = pointer to keyset list head
679 * @buf *b@ = pointer to input buffer
680 * @buf *bb@ = pointer to output buffer
681 *
682 * Returns: Nonzero if a new key is needed.
683 *
684 * Use: Encrypts a packet.
685 */
686
832a2ab6 687extern int ksl_encrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/);
410c8acf 688
832a2ab6 689/* --- @ksl_decrypt@ --- *
410c8acf 690 *
691 * Arguments: @keyset **ksroot@ = pointer to keyset list head
692 * @buf *b@ = pointer to input buffer
693 * @buf *bb@ = pointer to output buffer
694 *
695 * Returns: Nonzero if the packet couldn't be decrypted.
696 *
697 * Use: Decrypts a packet.
698 */
699
832a2ab6 700extern int ksl_decrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/);
410c8acf 701
702/*----- Administration interface ------------------------------------------*/
703
704/* --- @a_warn@ --- *
705 *
706 * Arguments: @const char *fmt@ = pointer to format string
707 * @...@ = other arguments
708 *
709 * Returns: ---
710 *
711 * Use: Informs all admin connections of a warning.
712 */
713
714extern void a_warn(const char */*fmt*/, ...);
715
716/* --- @a_create@ --- *
717 *
718 * Arguments: @int fd_in, fd_out@ = file descriptors to use
719 *
720 * Returns: ---
721 *
722 * Use: Creates a new admin connection.
723 */
724
725extern void a_create(int /*fd_in*/, int /*fd_out*/);
726
727/* --- @a_quit@ --- *
728 *
729 * Arguments: ---
730 *
731 * Returns: ---
732 *
733 * Use: Shuts things down nicely.
734 */
735
736extern void a_quit(void);
737
738/* --- @a_daemon@ --- *
739 *
740 * Arguments: ---
741 *
742 * Returns: ---
743 *
744 * Use: Informs the admin module that it's a daemon.
745 */
746
747extern void a_daemon(void);
748
749/* --- @a_init@ --- *
750 *
751 * Arguments: @const char *sock@ = socket name to create
752 *
753 * Returns: ---
754 *
755 * Use: Creates the admin listening socket.
756 */
757
758extern void a_init(const char */*sock*/);
759
760/*----- Peer management ---------------------------------------------------*/
761
762/* --- @p_txstart@ --- *
763 *
764 * Arguments: @peer *p@ = pointer to peer block
765 * @unsigned msg@ = message type code
766 *
767 * Returns: A pointer to a buffer to write to.
768 *
769 * Use: Starts sending to a peer. Only one send can happen at a
770 * time.
771 */
772
773extern buf *p_txstart(peer */*p*/, unsigned /*msg*/);
774
775/* --- @p_txend@ --- *
776 *
777 * Arguments: @peer *p@ = pointer to peer block
778 *
779 * Returns: ---
780 *
781 * Use: Sends a packet to the peer.
782 */
783
784extern void p_txend(peer */*p*/);
785
786/* --- @p_tun@ --- *
787 *
788 * Arguments: @peer *p@ = pointer to peer block
789 * @buf *b@ = buffer containing incoming packet
790 *
791 * Returns: ---
792 *
793 * Use: Handles a packet which needs to be sent to a peer.
794 */
795
796extern void p_tun(peer */*p*/, buf */*b*/);
797
798/* --- @p_interval@ --- *
799 *
800 * Arguments: ---
801 *
802 * Returns: ---
803 *
804 * Use: Called periodically to do tidying.
805 */
806
807extern void p_interval(void);
808
832a2ab6 809/* --- @p_stats@ --- *
810 *
811 * Arguments: @peer *p@ = pointer to a peer block
812 *
813 * Returns: A pointer to the peer's statistics.
814 */
815
816extern stats *p_stats(peer */*p*/);
817
410c8acf 818/* --- @p_ifname@ --- *
819 *
820 * Arguments: @peer *p@ = pointer to a peer block
821 *
822 * Returns: A pointer to the peer's interface name.
823 */
824
825extern const char *p_ifname(peer */*p*/);
826
827/* --- @p_addr@ --- *
828 *
829 * Arguments: @peer *p@ = pointer to a peer block
830 *
831 * Returns: A pointer to the peer's address.
832 */
833
834extern const addr *p_addr(peer */*p*/);
835
836/* --- @p_init@ --- *
837 *
838 * Arguments: @unsigned port@ = port number to listen to
839 *
840 * Returns: ---
841 *
842 * Use: Initializes the peer system; creates the socket.
843 */
844
845extern void p_init(unsigned /*port*/);
846
847/* --- @p_port@ --- *
848 *
849 * Arguments: ---
850 *
851 * Returns: Port number used for socket.
852 */
853
854unsigned p_port(void);
855
856/* --- @p_create@ --- *
857 *
858 * Arguments: @const char *name@ = name for this peer
859 * @struct sockaddr *sa@ = socket address of peer
860 * @size_t sz@ = size of socket address
861 *
862 * Returns: Pointer to the peer block, or null if it failed.
863 *
864 * Use: Creates a new named peer block. No peer is actually attached
865 * by this point.
866 */
867
868extern peer *p_create(const char */*name*/,
869 struct sockaddr */*sa*/, size_t /*sz*/);
870
871/* --- @p_name@ --- *
872 *
873 * Arguments: @peer *p@ = pointer to a peer block
874 *
875 * Returns: A pointer to the peer's name.
876 */
877
878extern const char *p_name(peer */*p*/);
879
880/* --- @p_find@ --- *
881 *
882 * Arguments: @const char *name@ = name to look up
883 *
884 * Returns: Pointer to the peer block, or null if not found.
885 *
886 * Use: Finds a peer by name.
887 */
888
889extern peer *p_find(const char */*name*/);
890
891/* --- @p_destroy@ --- *
892 *
893 * Arguments: @peer *p@ = pointer to a peer
894 *
895 * Returns: ---
896 *
897 * Use: Destroys a peer.
898 */
899
900extern void p_destroy(peer */*p*/);
901
902/* --- @p_first@, @p_next@ --- *
903 *
904 * Arguments: @peer *p@ = a peer block
905 *
906 * Returns: @peer_first@ returns the first peer in some ordering;
907 * @peer_next@ returns the peer following a given one in the
908 * same ordering. Null is returned for the end of the list.
909 */
910
911extern peer *p_first(void);
912extern peer *p_next(peer */*p*/);
913
914/*----- Tunnel interface --------------------------------------------------*/
915
916/* --- @tun_init@ --- *
917 *
918 * Arguments: ---
919 *
920 * Returns: ---
921 *
922 * Use: Initializes the tunneling system. Maybe this will require
923 * opening file descriptors or something.
924 */
925
926extern void tun_init(void);
927
928/* --- @tun_create@ --- *
929 *
930 * Arguments: @tunnel *t@ = pointer to tunnel block
931 * @peer *p@ = pointer to peer block
932 *
933 * Returns: Zero if it worked, nonzero on failure.
934 *
935 * Use: Initializes a new tunnel.
936 */
937
938extern int tun_create(tunnel */*t*/, peer */*p*/);
939
940/* --- @tun_ifname@ --- *
941 *
942 * Arguments: @tunnel *t@ = pointer to tunnel block
943 *
944 * Returns: A pointer to the tunnel's interface name.
945 */
946
947extern const char *tun_ifname(tunnel */*t*/);
948
949/* --- @tun_inject@ --- *
950 *
951 * Arguments: @tunnel *t@ = pointer to tunnel block
952 * @buf *b@ = buffer to send
953 *
954 * Returns: ---
955 *
956 * Use: Injects a packet into the local network stack.
957 */
958
959extern void tun_inject(tunnel */*t*/, buf */*b*/);
960
961/* --- @tun_destroy@ --- *
962 *
963 * Arguments: @tunnel *t@ = pointer to tunnel block
964 *
965 * Returns: ---
966 *
967 * Use: Destroys a tunnel.
968 */
969
970extern void tun_destroy(tunnel */*t*/);
971
972/*----- Buffer handling ---------------------------------------------------*/
973
974/* --- Useful macros --- */
975
976#define BBASE(b) ((b)->base)
977#define BLIM(b) ((b)->limit)
978#define BCUR(b) ((b)->p)
979#define BSZ(b) ((b)->limit - (b)->base)
980#define BLEN(b) ((b)->p - (b)->base)
981#define BLEFT(b) ((b)->limit - (b)->p)
982#define BSTEP(b, sz) ((b)->p += (sz))
983#define BBAD(b) ((b)->f & BF_BROKEN)
984#define BOK(b) (!BBAD(b))
985
986#define BENSURE(b, sz) \
987 (BBAD(b) ? -1 : (sz) > BLEFT(b) ? (b)->f |= BF_BROKEN, -1 : 0)
988
989/* --- @buf_init@ --- *
990 *
991 * Arguments: @buf *b@ = pointer to a buffer block
992 * @void *p@ = pointer to a buffer
993 * @size_t sz@ = size of the buffer
994 *
995 * Returns: ---
996 *
997 * Use: Initializes the buffer block appropriately.
998 */
999
1000extern void buf_init(buf */*b*/, void */*p*/, size_t /*sz*/);
1001
1002/* --- @buf_break@ --- *
1003 *
1004 * Arguments: @buf *b@ = pointer to a buffer block
1005 *
1006 * Returns: Some negative value.
1007 *
1008 * Use: Marks a buffer as broken.
1009 */
1010
1011extern int buf_break(buf */*b*/);
1012
832a2ab6 1013/* --- @buf_flip@ --- *
1014 *
1015 * Arguments: @buf *b@ = pointer to a buffer block
1016 *
1017 * Returns: ---
1018 *
1019 * Use: Flips a buffer so that if you've just been writing to it,
1020 * you can now read from the bit you've written.
1021 */
1022
1023extern void buf_flip(buf */*b*/);
1024
410c8acf 1025/* --- @buf_ensure@ --- *
1026 *
1027 * Arguments: @buf *b@ = pointer to a buffer block
1028 * @size_t sz@ = size of data wanted
1029 *
1030 * Returns: Zero if it worked, nonzero if there wasn't enough space.
1031 *
1032 * Use: Ensures that there are @sz@ bytes still in the buffer.
1033 */
1034
1035extern int buf_ensure(buf */*b*/, size_t /*sz*/);
1036
1037/* --- @buf_get@ --- *
1038 *
1039 * Arguments: @buf *b@ = pointer to a buffer block
410c8acf 1040 * @size_t sz@ = size of the buffer
1041 *
832a2ab6 1042 * Returns: Pointer to the place in the buffer.
410c8acf 1043 *
832a2ab6 1044 * Use: Reserves a space in the buffer of the requested size, and
1045 * returns its start address.
410c8acf 1046 */
1047
832a2ab6 1048extern void *buf_get(buf */*b*/, size_t /*sz*/);
410c8acf 1049
1050/* --- @buf_put@ --- *
1051 *
1052 * Arguments: @buf *b@ = pointer to a buffer block
1053 * @const void *p@ = pointer to a buffer
1054 * @size_t sz@ = size of the buffer
1055 *
1056 * Returns: Zero if it worked, nonzero if there wasn't enough space.
1057 *
1058 * Use: Fetches data from some place and puts it in the buffer
1059 */
1060
1061extern int buf_put(buf */*b*/, const void */*p*/, size_t /*sz*/);
1062
1063/* --- @buf_getbyte@ --- *
1064 *
1065 * Arguments: @buf *b@ = pointer to a buffer block
1066 *
1067 * Returns: A byte, or less than zero if there wasn't a byte there.
1068 *
1069 * Use: Gets a single byte from a buffer.
1070 */
1071
1072extern int buf_getbyte(buf */*b*/);
1073
1074/* --- @buf_putbyte@ --- *
1075 *
1076 * Arguments: @buf *b@ = pointer to a buffer block
1077 * @int ch@ = byte to write
1078 *
1079 * Returns: Zero if OK, nonzero if there wasn't enough space.
1080 *
1081 * Use: Puts a single byte in a buffer.
1082 */
1083
1084extern int buf_putbyte(buf */*b*/, int /*ch*/);
1085
1086/* --- @buf_getword@ --- *
1087 *
1088 * Arguments: @buf *b@ = pointer to a buffer block
1089 * @uint32 *w@ = where to put the word
1090 *
1091 * Returns: Zero if OK, or nonzero if there wasn't a word there.
1092 *
1093 * Use: Gets a 32-bit word from a buffer.
1094 */
1095
1096extern int buf_getword(buf */*b*/, uint32 */*w*/);
1097
1098/* --- @buf_putword@ --- *
1099 *
1100 * Arguments: @buf *b@ = pointer to a buffer block
1101 * @uint32 w@ = word to write
1102 *
1103 * Returns: Zero if OK, nonzero if there wasn't enough space.
1104 *
1105 * Use: Puts a 32-but word in a buffer.
1106 */
1107
1108extern int buf_putword(buf */*b*/, uint32 /*w*/);
1109
1110/* --- @buf_getmp@ --- *
1111 *
1112 * Arguments: @buf *b@ = pointer to a buffer block
1113 *
1114 * Returns: A multiprecision integer, or null if there wasn't one there.
1115 *
1116 * Use: Gets a multiprecision integer from a buffer.
1117 */
1118
832a2ab6 1119extern mp *buf_getmp(buf */*b*/);
410c8acf 1120
1121/* --- @buf_putmp@ --- *
1122 *
1123 * Arguments: @buf *b@ = pointer to a buffer block
1124 * @mp *m@ = a multiprecision integer
1125 *
1126 * Returns: Zero if it worked, nonzero if there wasn't enough space.
1127 *
1128 * Use: Puts a multiprecision integer to a buffer.
1129 */
1130
1131extern int buf_putmp(buf */*b*/, mp */*m*/);
1132
1133/*----- Other handy utilities ---------------------------------------------*/
1134
1135/* --- @mpstr@ --- *
1136 *
1137 * Arguments: @mp *m@ = a multiprecision integer
1138 *
1139 * Returns: A pointer to the integer's textual representation.
1140 *
1141 * Use: Converts a multiprecision integer to a string. Corrupts
832a2ab6 1142 * @buf_t@.
410c8acf 1143 */
1144
1145extern const char *mpstr(mp */*m*/);
1146
832a2ab6 1147/* --- @timestr@ --- *
1148 *
1149 * Arguments: @time_t t@ = a time to convert
1150 *
1151 * Returns: A pointer to a textual representation of the time.
1152 *
1153 * Use: Converts a time to a textual representation. Corrupts
1154 * @buf_t@.
1155 */
1156
1157extern const char *timestr(time_t /*t*/);
1158
410c8acf 1159/*----- That's all, folks -------------------------------------------------*/
1160
1161#ifdef __cplusplus
1162 }
1163#endif
1164
1165#endif