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