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 | |
292 | typedef 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 | |
310 | typedef 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 | |
341 | typedef 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 |
356 | typedef 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 | |
377 | enum { |
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 |
394 | typedef 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 | |
419 | typedef 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 | |
435 | typedef 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 | |
451 | typedef 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 |
457 | typedef 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 | |
479 | extern sel_state sel; /* Global I/O event state */ |
480 | extern dh_priv kpriv; /* Our private key */ |
481 | extern mpmont mg; /* Montgomery context for DH group */ |
832a2ab6 |
482 | extern octet buf_i[PKBUFSZ], buf_o[PKBUFSZ], buf_t[PKBUFSZ]; |
410c8acf |
483 | |
484 | #ifndef NTRACE |
485 | extern const trace_opt tr_opts[]; /* Trace options array */ |
486 | extern 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 | |
504 | extern 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 | |
517 | extern 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 |
531 | extern 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 | |
547 | extern 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 |
561 | extern 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 | |
572 | extern 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 | |
586 | extern 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 | |
601 | extern 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 | |
615 | extern 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 | |
640 | extern 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 | |
651 | extern 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 | |
663 | extern 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 | |
681 | extern 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 | |
696 | extern 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 |
707 | extern 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 |
720 | extern 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 |
732 | extern 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 |
745 | extern 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 |
758 | extern 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 | |
772 | extern 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 | |
783 | extern 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 | |
794 | extern 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 | |
805 | extern 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 | |
816 | extern 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 | |
831 | extern 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 | |
842 | extern 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 | |
854 | extern 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 | |
865 | extern 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 | |
874 | extern 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 | |
883 | extern 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 | |
892 | extern 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 | |
903 | extern void p_init(unsigned /*port*/); |
904 | |
905 | /* --- @p_port@ --- * |
906 | * |
907 | * Arguments: --- |
908 | * |
909 | * Returns: Port number used for socket. |
910 | */ |
911 | |
912 | unsigned 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 | |
926 | extern 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 | |
936 | extern 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 | |
947 | extern 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 | |
958 | extern 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 | |
969 | extern peer *p_first(void); |
970 | extern 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 | |
984 | extern 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 | |
996 | extern 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 | |
1005 | extern 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 | |
1017 | extern 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 | |
1028 | extern 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 | |
1042 | extern 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 | |
1054 | extern const char *timestr(time_t /*t*/); |
1055 | |
410c8acf |
1056 | /*----- That's all, folks -------------------------------------------------*/ |
1057 | |
1058 | #ifdef __cplusplus |
1059 | } |
1060 | #endif |
1061 | |
1062 | #endif |