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