chiark / gitweb /
server/tests.at: Fix TRIPECTL_INTERACT argument order.
[tripe] / server / keyset.c
CommitLineData
410c8acf 1/* -*-c-*-
2 *
410c8acf 3 * Handling of symmetric keysets
4 *
5 * (c) 2001 Straylight/Edgeware
6 */
7
e04c2d50 8/*----- Licensing notice --------------------------------------------------*
410c8acf 9 *
10 * This file is part of Trivial IP Encryption (TrIPE).
11 *
12 * TrIPE is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
e04c2d50 16 *
410c8acf 17 * TrIPE is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
e04c2d50 21 *
410c8acf 22 * You should have received a copy of the GNU General Public License
23 * along with TrIPE; if not, write to the Free Software Foundation,
24 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25 */
26
410c8acf 27/*----- Header files ------------------------------------------------------*/
28
29#include "tripe.h"
30
31/*----- Tunable parameters ------------------------------------------------*/
32
426c0bc6 33#define T_EXP MIN(60) /* Expiry time for a key */
34#define T_REGEN MIN(45) /* Regeneration time for a key */
410c8acf 35
36/*----- Handy macros ------------------------------------------------------*/
37
38#define KEYOK(ks, now) ((ks)->sz_exp > 0 && (ks)->t_exp > now)
39
b5c45da1 40#define SEQSZ 4 /* Size of sequence number packet */
41
426c0bc6 42/*----- Low-level packet encryption and decryption ------------------------*/
410c8acf 43
59d670e7 44/* --- Encrypted data format --- *
45 *
7ed14135 46 * Let %$p_i$% be the %$i$%-th plaintext message, with type %$t$%. We first
e04c2d50 47 * compute
59d670e7 48 *
49 * %$c_i = \mathcal{E}\textrm{-CBC}_{K_{\text{E}}}(p_i)$%
50 *
51 * as the CBC-ciphertext of %$p_i$%, and then
52 *
7ed14135 53 * %$\sigma_i = \mathcal{T}_{K_{\text{M}}}(t, i, c_i)$%
59d670e7 54 *
55 * as a MAC on the %%\emph{ciphertext}%%. The message sent is then the pair
56 * %$(\sigma_i, c_i)$%. This construction is provably secure in the NM-CCA
57 * sense (assuming that the cipher is IND-CPA, and the MAC is SUF-CMA)
58 * [Bellare and Namprempre].
59 *
60 * This also ensures that, assuming the key is good, we have a secure channel
61 * [Krawczyk]. Actually, [Krawczyk] shows that, if the cipher is either a
62 * simple stream cipher or a block cipher in CBC mode, we can use the MAC-
63 * then-encrypt scheme and still have a secure channel. However, I like the
64 * NM-CCA guarantee from [Bellare and Namprempre]. I'm less worried about
65 * the Horton Principle [Wagner and Schneier].
66 */
67
426c0bc6 68/* --- @doencrypt@ --- *
410c8acf 69 *
426c0bc6 70 * Arguments: @keyset *ks@ = pointer to keyset to use
7ed14135 71 * @unsigned ty@ = type of message this is
426c0bc6 72 * @buf *b@ = pointer to an input buffer
73 * @buf *bb@ = pointer to an output buffer
410c8acf 74 *
a50f9a0e
MW
75 * Returns: Zero if OK; @KSERR_REGEN@ if it's time to generate new keys.
76 * Also returns zero if there was insufficient buffer space, but
77 * the buffer is broken in this case.
410c8acf 78 *
426c0bc6 79 * Use: Encrypts a message with the given key. We assume that the
80 * keyset is OK to use.
410c8acf 81 */
82
7ed14135 83static int doencrypt(keyset *ks, unsigned ty, buf *b, buf *bb)
410c8acf 84{
426c0bc6 85 ghash *h;
b5c45da1 86 gcipher *c = ks->cout;
426c0bc6 87 const octet *p = BCUR(b);
88 size_t sz = BLEFT(b);
59d670e7 89 octet *qmac, *qseq, *qiv, *qpk;
426c0bc6 90 uint32 oseq;
b5c45da1 91 size_t ivsz = GC_CLASS(c)->blksz;
92 size_t tagsz = ks->tagsz;
426c0bc6 93 size_t osz, nsz;
7ed14135 94 octet t[4];
426c0bc6 95 int rc = 0;
96
97 /* --- Allocate the required buffer space --- */
98
b5c45da1 99 if (buf_ensure(bb, tagsz + SEQSZ + ivsz + sz))
426c0bc6 100 return (0); /* Caution! */
b5c45da1 101 qmac = BCUR(bb); qseq = qmac + tagsz; qiv = qseq + SEQSZ; qpk = qiv + ivsz;
102 BSTEP(bb, tagsz + SEQSZ + ivsz + sz);
7ed14135 103 STORE32(t, ty);
426c0bc6 104
426c0bc6 105 oseq = ks->oseq++; STORE32(qseq, oseq);
426c0bc6 106 IF_TRACING(T_KEYSET, {
107 trace(T_KEYSET, "keyset: encrypting packet %lu using keyset %u",
108 (unsigned long)oseq, ks->seq);
b5c45da1 109 trace_block(T_CRYPTO, "crypto: plaintext packet", p, sz);
426c0bc6 110 })
59d670e7 111
b5c45da1 112 /* --- Encrypt the packet --- */
59d670e7 113
b5c45da1 114 if (ivsz) {
115 rand_get(RAND_GLOBAL, qiv, ivsz);
116 GC_SETIV(c, qiv);
117 IF_TRACING(T_KEYSET, {
118 trace_block(T_CRYPTO, "crypto: initialization vector", qiv, ivsz);
119 })
120 }
121 GC_ENCRYPT(c, p, qpk, sz);
426c0bc6 122 IF_TRACING(T_KEYSET, {
b5c45da1 123 trace_block(T_CRYPTO, "crypto: encrypted packet", qpk, sz);
426c0bc6 124 })
125
b5c45da1 126 /* --- Now compute the MAC --- */
127
128 if (tagsz) {
129 h = GM_INIT(ks->mout);
130 GH_HASH(h, t, sizeof(t));
131 GH_HASH(h, qseq, SEQSZ + ivsz + sz);
132 memcpy(qmac, GH_DONE(h, 0), tagsz);
133 GH_DESTROY(h);
134 IF_TRACING(T_KEYSET, {
135 trace_block(T_CRYPTO, "crypto: computed MAC", qmac, tagsz);
136 })
137 }
138
426c0bc6 139 /* --- Deduct the packet size from the key's data life --- */
140
141 osz = ks->sz_exp;
142 if (osz > sz)
143 nsz = osz - sz;
144 else
145 nsz = 0;
383a9d71 146 if (osz >= ks->sz_regen && ks->sz_regen > nsz) {
426c0bc6 147 T( trace(T_KEYSET, "keyset: keyset %u data regen limit exceeded -- "
148 "forcing exchange", ks->seq); )
a50f9a0e 149 rc = KSERR_REGEN;
426c0bc6 150 }
151 ks->sz_exp = nsz;
e04c2d50 152 return (rc);
410c8acf 153}
154
426c0bc6 155/* --- @dodecrypt@ --- *
410c8acf 156 *
426c0bc6 157 * Arguments: @keyset *ks@ = pointer to keyset to use
7ed14135 158 * @unsigned ty@ = expected type code
426c0bc6 159 * @buf *b@ = pointer to an input buffer
160 * @buf *bb@ = pointer to an output buffer
161 * @uint32 *seq@ = where to store the sequence number
410c8acf 162 *
a50f9a0e 163 * Returns: Zero on success; @KSERR_DECRYPT@ on failure.
410c8acf 164 *
426c0bc6 165 * Use: Attempts to decrypt a message with the given key. No other
166 * checking (e.g., sequence number checks) is performed. We
167 * assume that the keyset is OK to use, and that there is
168 * sufficient output buffer space reserved. If the decryption
169 * is successful, the buffer pointer is moved past the decrypted
170 * packet, and the packet's sequence number is stored in @*seq@.
410c8acf 171 */
172
7ed14135 173static int dodecrypt(keyset *ks, unsigned ty, buf *b, buf *bb, uint32 *seq)
410c8acf 174{
59d670e7 175 const octet *pmac, *piv, *pseq, *ppk;
426c0bc6 176 size_t psz = BLEFT(b);
177 size_t sz;
178 octet *q = BCUR(bb);
179 ghash *h;
180 gcipher *c = ks->cin;
b5c45da1 181 size_t ivsz = GC_CLASS(c)->blksz;
182 size_t tagsz = ks->tagsz;
426c0bc6 183 octet *mac;
184 int eq;
7ed14135 185 octet t[4];
426c0bc6 186
187 /* --- Break up the packet into its components --- */
188
b5c45da1 189 if (psz < ivsz + SEQSZ + tagsz) {
426c0bc6 190 T( trace(T_KEYSET, "keyset: block too small for keyset %u", ks->seq); )
a50f9a0e 191 return (KSERR_DECRYPT);
410c8acf 192 }
b5c45da1 193 sz = psz - ivsz - SEQSZ - tagsz;
194 pmac = BCUR(b); pseq = pmac + tagsz; piv = pseq + SEQSZ; ppk = piv + ivsz;
7ed14135 195 STORE32(t, ty);
426c0bc6 196
426c0bc6 197 IF_TRACING(T_KEYSET, {
198 trace(T_KEYSET, "keyset: decrypting using keyset %u", ks->seq);
b5c45da1 199 trace_block(T_CRYPTO, "crypto: ciphertext packet", ppk, sz);
426c0bc6 200 })
b5c45da1 201
202 /* --- Verify the MAC on the packet --- */
203
204 if (tagsz) {
205 h = GM_INIT(ks->min);
206 GH_HASH(h, t, sizeof(t));
207 GH_HASH(h, pseq, SEQSZ + ivsz + sz);
208 mac = GH_DONE(h, 0);
209 eq = !memcmp(mac, pmac, tagsz);
426c0bc6 210 IF_TRACING(T_KEYSET, {
b5c45da1 211 trace_block(T_CRYPTO, "crypto: computed MAC", mac, tagsz);
426c0bc6 212 })
b5c45da1 213 GH_DESTROY(h);
214 if (!eq) {
215 IF_TRACING(T_KEYSET, {
216 trace(T_KEYSET, "keyset: incorrect MAC: decryption failed");
217 trace_block(T_CRYPTO, "crypto: expected MAC", pmac, tagsz);
218 })
a50f9a0e 219 return (KSERR_DECRYPT);
b5c45da1 220 }
426c0bc6 221 }
59d670e7 222
223 /* --- Decrypt the packet --- */
224
b5c45da1 225 if (ivsz) {
226 GC_SETIV(c, piv);
227 IF_TRACING(T_KEYSET, {
228 trace_block(T_CRYPTO, "crypto: initialization vector", piv, ivsz);
229 })
230 }
231 GC_DECRYPT(c, ppk, q, sz);
426c0bc6 232 if (seq)
233 *seq = LOAD32(pseq);
234 IF_TRACING(T_KEYSET, {
235 trace(T_KEYSET, "keyset: decrypted OK (sequence = %lu)",
236 (unsigned long)LOAD32(pseq));
237 trace_block(T_CRYPTO, "crypto: decrypted packet", q, sz);
238 })
239 BSTEP(bb, sz);
240 return (0);
410c8acf 241}
242
426c0bc6 243/*----- Operations on a single keyset -------------------------------------*/
244
245/* --- @ks_drop@ --- *
246 *
247 * Arguments: @keyset *ks@ = pointer to a keyset
248 *
249 * Returns: ---
250 *
251 * Use: Decrements a keyset's reference counter. If the counter hits
252 * zero, the keyset is freed.
253 */
254
255void ks_drop(keyset *ks)
256{
257 if (--ks->ref)
258 return;
b5c45da1 259 GC_DESTROY(ks->cin);
260 GC_DESTROY(ks->cout);
261 GM_DESTROY(ks->min);
262 GM_DESTROY(ks->mout);
426c0bc6 263 DESTROY(ks);
410c8acf 264}
265
266/* --- @ks_gen@ --- *
267 *
426c0bc6 268 * Arguments: @const void *k@ = pointer to key material
269 * @size_t x, y, z@ = offsets into key material (see below)
e04c2d50 270 * @peer *p@ = pointer to peer information
410c8acf 271 *
426c0bc6 272 * Returns: A pointer to the new keyset.
410c8acf 273 *
426c0bc6 274 * Use: Derives a new keyset from the given key material. The
275 * offsets @x@, @y@ and @z@ separate the key material into three
276 * parts. Between the @k@ and @k + x@ is `my' contribution to
277 * the key material; between @k + x@ and @k + y@ is `your'
278 * contribution; and between @k + y@ and @k + z@ is a shared
279 * value we made together. These are used to construct two
280 * pairs of symmetric keys. Each pair consists of an encryption
281 * key and a message authentication key. One pair is used for
282 * outgoing messages, the other for incoming messages.
283 *
284 * The new key is marked so that it won't be selected for output
285 * by @ksl_encrypt@. You can still encrypt data with it by
286 * calling @ks_encrypt@ directly.
410c8acf 287 */
288
9466fafa 289keyset *ks_gen(const void *k, size_t x, size_t y, size_t z, peer *p)
410c8acf 290{
b5c45da1 291 ghash *h;
292 const octet *hh;
410c8acf 293 keyset *ks = CREATE(keyset);
294 time_t now = time(0);
9466fafa 295 const octet *pp = k;
410c8acf 296 T( static unsigned seq = 0; )
297
298 T( trace(T_KEYSET, "keyset: adding new keyset %u", seq); )
299
426c0bc6 300 /* --- Construct the various keys --- *
301 *
302 * This is done with macros, because it's quite tedious.
303 */
304
b5c45da1 305#define MINE GH_HASH(h, pp, x)
306#define YOURS GH_HASH(h, pp + x, y - x)
307#define OURS GH_HASH(h, pp + y, z - y)
308
309#define HASH_in MINE; YOURS; OURS
310#define HASH_out YOURS; MINE; OURS
311#define INIT_c(k) GC_INIT(algs.c, (k), algs.cksz)
312#define INIT_m(k) GM_KEY(algs.m, (k), algs.mksz)
313#define STR_c "encryption"
314#define STR_m "integrity"
315#define STR_in "incoming"
316#define STR_out "outgoing"
317
318#define SETKEY(a, dir) do { \
319 h = GH_INIT(algs.h); \
320 HASH_STRING(h, "tripe-" STR_##a); \
321 HASH_##dir; \
322 hh = GH_DONE(h, 0); \
410c8acf 323 IF_TRACING(T_KEYSET, { \
b5c45da1 324 trace_block(T_CRYPTO, "crypto: " STR_##dir " key " STR_##a, \
325 hh, algs.a##ksz); \
410c8acf 326 }) \
b5c45da1 327 ks->a##dir = INIT_##a(hh); \
328 GH_DESTROY(h); \
410c8acf 329} while (0)
330
b5c45da1 331 SETKEY(c, in); SETKEY(c, out);
332 SETKEY(m, in); SETKEY(m, out);
426c0bc6 333
334#undef MINE
335#undef YOURS
336#undef OURS
b5c45da1 337#undef STR_c
338#undef STR_m
339#undef STR_in
340#undef STR_out
341#undef INIT_c
342#undef INIT_m
343#undef HASH_in
344#undef HASH_out
345#undef SETKEY
410c8acf 346
347 T( ks->seq = seq++; )
e945d6e4 348 ks->ref = 1;
426c0bc6 349 ks->t_exp = now + T_EXP;
383a9d71
MW
350 ks->sz_exp = algs.expsz;
351 ks->sz_regen = algs.expsz/2;
37941236 352 ks->oseq = 0;
353 seq_reset(&ks->iseq);
426c0bc6 354 ks->next = 0;
9466fafa 355 ks->p = p;
426c0bc6 356 ks->f = KSF_LISTEN;
b5c45da1 357 ks->tagsz = algs.tagsz;
426c0bc6 358 return (ks);
359}
360
361/* --- @ks_tregen@ --- *
362 *
363 * Arguments: @keyset *ks@ = pointer to a keyset
364 *
365 * Returns: The time at which moves ought to be made to replace this key.
366 */
367
368time_t ks_tregen(keyset *ks) { return (ks->t_exp - T_EXP + T_REGEN); }
369
370/* --- @ks_activate@ --- *
371 *
372 * Arguments: @keyset *ks@ = pointer to a keyset
373 *
374 * Returns: ---
375 *
376 * Use: Activates a keyset, so that it can be used for encrypting
377 * outgoing messages.
378 */
379
380void ks_activate(keyset *ks)
381{
382 if (ks->f & KSF_LISTEN) {
383 T( trace(T_KEYSET, "keyset: activating keyset %u", ks->seq); )
384 ks->f &= ~KSF_LISTEN;
385 }
410c8acf 386}
387
388/* --- @ks_encrypt@ --- *
389 *
426c0bc6 390 * Arguments: @keyset *ks@ = pointer to a keyset
7ed14135 391 * @unsigned ty@ = message type
426c0bc6 392 * @buf *b@ = pointer to input buffer
393 * @buf *bb@ = pointer to output buffer
394 *
a50f9a0e
MW
395 * Returns: Zero if successful; @KSERR_REGEN@ if we should negotiate a
396 * new key; @KSERR_NOKEYS@ if the key is not usable. Also
397 * returns zero if there was insufficient buffer (but the output
398 * buffer is broken in this case).
426c0bc6 399 *
400 * Use: Encrypts a block of data using the key. Note that the `key
401 * ought to be replaced' notification is only ever given once
402 * for each key. Also note that this call forces a keyset to be
403 * used even if it's marked as not for data output.
404 */
405
7ed14135 406int ks_encrypt(keyset *ks, unsigned ty, buf *b, buf *bb)
426c0bc6 407{
408 time_t now = time(0);
409
410 if (!KEYOK(ks, now)) {
411 buf_break(bb);
a50f9a0e 412 return (KSERR_NOKEYS);
426c0bc6 413 }
7ed14135 414 return (doencrypt(ks, ty, b, bb));
426c0bc6 415}
416
417/* --- @ks_decrypt@ --- *
418 *
419 * Arguments: @keyset *ks@ = pointer to a keyset
7ed14135 420 * @unsigned ty@ = expected type code
426c0bc6 421 * @buf *b@ = pointer to an input buffer
422 * @buf *bb@ = pointer to an output buffer
423 *
a50f9a0e
MW
424 * Returns: Zero on success; @KSERR_DECRYPT@ on failure. Also returns
425 * zero if there was insufficient buffer (but the output buffer
426 * is broken in this case).
426c0bc6 427 *
428 * Use: Attempts to decrypt a message using a given key. Note that
429 * requesting decryption with a key directly won't clear a
430 * marking that it's not for encryption.
431 */
432
7ed14135 433int ks_decrypt(keyset *ks, unsigned ty, buf *b, buf *bb)
426c0bc6 434{
435 time_t now = time(0);
436 uint32 seq;
437
438 if (!KEYOK(ks, now) ||
439 buf_ensure(bb, BLEN(b)) ||
7ed14135 440 dodecrypt(ks, ty, b, bb, &seq) ||
f43df819 441 seq_check(&ks->iseq, seq, "SYMM"))
a50f9a0e 442 return (KSERR_DECRYPT);
426c0bc6 443 return (0);
444}
445
446/*----- Keyset list handling ----------------------------------------------*/
447
448/* --- @ksl_free@ --- *
449 *
450 * Arguments: @keyset **ksroot@ = pointer to keyset list head
451 *
452 * Returns: ---
453 *
454 * Use: Frees (releases references to) all of the keys in a keyset.
455 */
456
457void ksl_free(keyset **ksroot)
458{
459 keyset *ks, *ksn;
460 for (ks = *ksroot; ks; ks = ksn) {
461 ksn = ks->next;
462 ks->f &= ~KSF_LINK;
463 ks_drop(ks);
464 }
465}
466
467/* --- @ksl_link@ --- *
468 *
469 * Arguments: @keyset **ksroot@ = pointer to keyset list head
470 * @keyset *ks@ = pointer to a keyset
471 *
472 * Returns: ---
473 *
474 * Use: Links a keyset into a list. A keyset can only be on one list
475 * at a time. Bad things happen otherwise.
476 */
477
478void ksl_link(keyset **ksroot, keyset *ks)
479{
480 assert(!(ks->f & KSF_LINK));
481 ks->next = *ksroot;
482 *ksroot = ks;
483 ks->f |= KSF_LINK;
484 ks->ref++;
485}
486
487/* --- @ksl_prune@ --- *
488 *
489 * Arguments: @keyset **ksroot@ = pointer to keyset list head
490 *
491 * Returns: ---
492 *
493 * Use: Prunes the keyset list by removing keys which mustn't be used
494 * any more.
495 */
496
497void ksl_prune(keyset **ksroot)
498{
499 time_t now = time(0);
500
501 while (*ksroot) {
502 keyset *ks = *ksroot;
503
504 if (ks->t_exp <= now) {
505 T( trace(T_KEYSET, "keyset: expiring keyset %u (time limit reached)",
506 ks->seq); )
507 goto kill;
508 } else if (ks->sz_exp == 0) {
509 T( trace(T_KEYSET, "keyset: expiring keyset %u (data limit reached)",
510 ks->seq); )
511 goto kill;
512 } else {
513 ksroot = &ks->next;
514 continue;
515 }
516
517 kill:
518 *ksroot = ks->next;
519 ks->f &= ~KSF_LINK;
520 ks_drop(ks);
521 }
522}
523
524/* --- @ksl_encrypt@ --- *
525 *
410c8acf 526 * Arguments: @keyset **ksroot@ = pointer to keyset list head
7ed14135 527 * @unsigned ty@ = message type
410c8acf 528 * @buf *b@ = pointer to input buffer
529 * @buf *bb@ = pointer to output buffer
530 *
a50f9a0e
MW
531 * Returns: Zero if successful; @KSERR_REGEN@ if it's time to negotiate a
532 * new key; @KSERR_NOKEYS@ if there are no suitable keys
533 * available. Also returns zero if there was insufficient
534 * buffer space (but the output buffer is broken in this case).
410c8acf 535 *
536 * Use: Encrypts a packet.
537 */
538
7ed14135 539int ksl_encrypt(keyset **ksroot, unsigned ty, buf *b, buf *bb)
410c8acf 540{
541 time_t now = time(0);
426c0bc6 542 keyset *ks = *ksroot;
410c8acf 543
410c8acf 544 for (;;) {
545 if (!ks) {
426c0bc6 546 T( trace(T_KEYSET, "keyset: no suitable keysets found"); )
410c8acf 547 buf_break(bb);
a50f9a0e 548 return (KSERR_NOKEYS);
410c8acf 549 }
426c0bc6 550 if (KEYOK(ks, now) && !(ks->f & KSF_LISTEN))
410c8acf 551 break;
552 ks = ks->next;
553 }
554
7ed14135 555 return (doencrypt(ks, ty, b, bb));
410c8acf 556}
557
426c0bc6 558/* --- @ksl_decrypt@ --- *
410c8acf 559 *
560 * Arguments: @keyset **ksroot@ = pointer to keyset list head
7ed14135 561 * @unsigned ty@ = expected type code
410c8acf 562 * @buf *b@ = pointer to input buffer
563 * @buf *bb@ = pointer to output buffer
564 *
a50f9a0e
MW
565 * Returns: Zero on success; @KSERR_DECRYPT@ on failure. Also returns
566 * zero if there was insufficient buffer (but the output buffer
567 * is broken in this case).
410c8acf 568 *
569 * Use: Decrypts a packet.
570 */
571
7ed14135 572int ksl_decrypt(keyset **ksroot, unsigned ty, buf *b, buf *bb)
410c8acf 573{
574 time_t now = time(0);
410c8acf 575 keyset *ks;
426c0bc6 576 uint32 seq;
410c8acf 577
426c0bc6 578 if (buf_ensure(bb, BLEN(b)))
a50f9a0e 579 return (KSERR_DECRYPT);
09585a65 580
410c8acf 581 for (ks = *ksroot; ks; ks = ks->next) {
410c8acf 582 if (!KEYOK(ks, now))
583 continue;
7ed14135 584 if (!dodecrypt(ks, ty, b, bb, &seq)) {
426c0bc6 585 if (ks->f & KSF_LISTEN) {
586 T( trace(T_KEYSET, "keyset: implicitly activating keyset %u",
587 ks->seq); )
588 ks->f &= ~KSF_LISTEN;
589 }
a50f9a0e
MW
590 if (seq_check(&ks->iseq, seq, "SYMM"))
591 return (KSERR_DECRYPT);
592 else
593 return (0);
410c8acf 594 }
410c8acf 595 }
e945d6e4 596 T( trace(T_KEYSET, "keyset: no matching keys, or incorrect MAC"); )
a50f9a0e 597 return (KSERR_DECRYPT);
410c8acf 598}
599
600/*----- That's all, folks -------------------------------------------------*/