8dd8c294 |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: seal.c,v 1.1 2000/06/17 12:08:34 mdw Exp $ |
4 | * |
5 | * The SEAL pseudo-random function family |
6 | * |
7 | * (c) 2000 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Catacomb. |
13 | * |
14 | * Catacomb is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
18 | * |
19 | * Catacomb 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 Library General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with Catacomb; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: seal.c,v $ |
33 | * Revision 1.1 2000/06/17 12:08:34 mdw |
34 | * New cipher. |
35 | * |
36 | */ |
37 | |
38 | /*----- Header files ------------------------------------------------------*/ |
39 | |
40 | #include <assert.h> |
41 | #include <stdarg.h> |
42 | #include <stdio.h> |
43 | |
44 | #include <mLib/bits.h> |
45 | |
46 | #include "arena.h" |
47 | #include "gcipher.h" |
48 | #include "grand.h" |
49 | #include "paranoia.h" |
50 | #include "seal.h" |
51 | #include "sha.h" |
52 | |
53 | /*----- Global variables --------------------------------------------------*/ |
54 | |
55 | const octet seal_keysz[] = { KSZ_ANY, SHA_HASHSZ }; |
56 | |
57 | /*----- Main code ---------------------------------------------------------*/ |
58 | |
59 | /* --- @gamma@ --- * |
60 | * |
61 | * Arguments: @uint32 *p@ = output table |
62 | * @size_t sz@ = size of the output table |
63 | * @const void *k@ = pointer to key material |
64 | * @unsigned i@ = integer offset |
65 | * |
66 | * Returns: --- |
67 | * |
68 | * Use: Initializes a SEAL key table. |
69 | */ |
70 | |
71 | static void gamma(uint32 *p, size_t sz, const void *k, unsigned i) |
72 | { |
73 | uint32 buf[80] = { 0 }; |
74 | const octet *kk = k; |
75 | uint32 aa = LOAD32(kk); |
76 | uint32 bb = LOAD32(kk + 4); |
77 | uint32 cc = LOAD32(kk + 8); |
78 | uint32 dd = LOAD32(kk + 12); |
79 | uint32 ee = LOAD32(kk + 16); |
80 | |
81 | unsigned skip = i % 5; |
82 | i /= 5; |
83 | |
84 | /* --- While there's hashing to do, do hashing --- */ |
85 | |
86 | while (sz) { |
87 | uint32 a = aa, b = bb, c = cc, d = dd, e = ee; |
88 | int j; |
89 | |
90 | /* --- Initialize and expand the buffer --- */ |
91 | |
92 | buf[0] = i++; |
93 | |
94 | for (j = 16; j < 80; j++) { |
95 | uint32 x = buf[j - 3] ^ buf[j - 8] ^ buf[j - 14] ^ buf[j - 16]; |
96 | buf[j] = ROL32(x, 1); |
97 | } |
98 | |
99 | /* --- Definitions for round functions --- */ |
100 | |
101 | #define F(x, y, z) (((x) & (y)) | (~(x) & (z))) |
102 | #define G(x, y, z) ((x) ^ (y) ^ (z)) |
103 | #define H(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z))) |
104 | |
105 | #define T(v, w, x, y, z, i, f, k) do { \ |
106 | uint32 _x; \ |
107 | z = ROL32(v, 5) + f(w, x, y) + z + buf[i] + k; \ |
108 | w = ROR32(w, 2); \ |
109 | _x = v; v = z; z = y; y = x; x = w; w = _x; \ |
110 | } while (0) |
111 | |
112 | #define FF(v, w, x, y, z, i) T(v, w, x, y, z, i, F, 0x5a827999) |
113 | #define GG(v, w, x, y, z, i) T(v, w, x, y, z, i, G, 0x6ed9eba1) |
114 | #define HH(v, w, x, y, z, i) T(v, w, x, y, z, i, H, 0x8f1bbcdc) |
115 | #define II(v, w, x, y, z, i) T(v, w, x, y, z, i, G, 0xca62c1d6) |
116 | |
117 | /* --- The main compression function --- * |
118 | * |
119 | * Since this isn't doing bulk hashing, do it the easy way. |
120 | */ |
121 | |
122 | for (j = 0; j < 20; j++) |
123 | FF(a, b, c, d, e, j); |
124 | for (j = 20; j < 40; j++) |
125 | GG(a, b, c, d, e, j); |
126 | for (j = 40; j < 60; j++) |
127 | HH(a, b, c, d, e, j); |
128 | for (j = 60; j < 80; j++) |
129 | II(a, b, c, d, e, j); |
130 | |
131 | /* --- Do the chaining at the end --- */ |
132 | |
133 | a += aa; b += bb; c += cc; d += dd; e += ee; |
134 | |
135 | /* --- Write to the output buffer --- */ |
136 | |
137 | switch (skip) { |
138 | case 0: |
139 | if (sz) { *p++ = a; sz--; } |
140 | case 1: |
141 | if (sz) { *p++ = b; sz--; } |
142 | case 2: |
143 | if (sz) { *p++ = c; sz--; } |
144 | case 3: |
145 | if (sz) { *p++ = d; sz--; } |
146 | case 4: |
147 | if (sz) { *p++ = e; sz--; } |
148 | skip = 0; |
149 | } |
150 | } |
151 | } |
152 | |
153 | /* --- @seal_initkey@ --- * |
154 | * |
155 | * Arguments: @seal_key *k@ = pointer to key block |
156 | * @const void *buf@ = pointer to key material |
157 | * @size_t sz@ = size of the key material |
158 | * |
159 | * Returns: --- |
160 | * |
161 | * Use: Initializes a SEAL key block. The key material may be any |
162 | * size, but if it's not 20 bytes long it's passed to SHA for |
163 | * hashing first. |
164 | */ |
165 | |
166 | void seal_initkey(seal_key *k, const void *buf, size_t sz) |
167 | { |
168 | /* --- Hash the key if it's the wrong size --- */ |
169 | |
170 | if (sz == SHA_HASHSZ) |
171 | memcpy(k->k, buf, sizeof(k->k)); |
172 | else { |
173 | sha_ctx c; |
174 | sha_init(&c); |
175 | sha_hash(&c, buf, sz); |
176 | sha_done(&c, k->k); |
177 | } |
178 | |
179 | /* --- Expand the key to fit the various tables --- */ |
180 | |
181 | gamma(k->t, 512, k->k, 0); |
182 | gamma(k->s, 256, k->k, 0x1000); |
183 | gamma(k->r, SEAL_R, k->k, 0x2000); |
184 | } |
185 | |
186 | /* --- @seal_reset@ --- * |
187 | * |
188 | * Arguments: @seal_ctx *c@ = pointer to a SEAL context |
189 | * |
190 | * Returns: --- |
191 | * |
192 | * Use: Resets the context so that more data can be extracted from |
193 | * it. |
194 | */ |
195 | |
196 | static void seal_reset(seal_ctx *c) |
197 | { |
198 | seal_key *k = c->k; |
199 | uint32 n = c->n; |
200 | uint32 A, B, C, D; |
201 | unsigned p; |
202 | |
203 | /* --- Initialize the new chaining variables --- */ |
204 | |
205 | if (c->l >= SEAL_R) { |
206 | gamma(c->rbuf, SEAL_R, k->k, c->ri); |
207 | c->ri += SEAL_R; |
208 | c->l = 0; |
209 | c->r = c->rbuf; |
210 | } |
211 | |
212 | A = n ^ c->r[0]; |
213 | B = ROR32(n, 8) ^ c->r[1]; |
214 | C = ROR32(n, 16) ^ c->r[2]; |
215 | D = ROR32(n, 24) ^ c->r[3]; |
216 | c->l += 4; |
217 | c->r += 4; |
218 | |
219 | /* --- Ensure that everything is sufficiently diffused --- */ |
220 | |
221 | p = A & 0x7fc; B += k->t[p >> 2]; A = ROR32(A, 9); |
222 | p = B & 0x7fc; C += k->t[p >> 2]; B = ROR32(B, 9); |
223 | p = C & 0x7fc; D += k->t[p >> 2]; C = ROR32(C, 9); |
224 | p = D & 0x7fc; A += k->t[p >> 2]; D = ROR32(D, 9); |
225 | p = A & 0x7fc; B += k->t[p >> 2]; A = ROR32(A, 9); |
226 | p = B & 0x7fc; C += k->t[p >> 2]; B = ROR32(B, 9); |
227 | p = C & 0x7fc; D += k->t[p >> 2]; C = ROR32(C, 9); |
228 | p = D & 0x7fc; A += k->t[p >> 2]; D = ROR32(D, 9); |
229 | |
230 | /* --- Write out some context --- */ |
231 | |
232 | c->n1 = D; c->n2 = B; c->n3 = A; c->n4 = C; |
233 | |
234 | /* --- Diffuse some more --- */ |
235 | |
236 | p = A & 0x7fc; B += k->t[p >> 2]; A = ROR32(A, 9); |
237 | p = B & 0x7fc; C += k->t[p >> 2]; B = ROR32(B, 9); |
238 | p = C & 0x7fc; D += k->t[p >> 2]; C = ROR32(C, 9); |
239 | p = D & 0x7fc; A += k->t[p >> 2]; D = ROR32(D, 9); |
240 | |
241 | /* --- Write out the magic numbers --- */ |
242 | |
243 | c->a = A; c->b = B; c->c = C; c->d = D; |
244 | c->i = 0; |
245 | } |
246 | |
247 | /* --- @seal_initctx@ --- * |
248 | * |
249 | * Arguments: @seal_ctx *c@ = pointer to a SEAL context |
250 | * @seal_key *k@ = pointer to a SEAL key |
251 | * @uint32 n@ = integer sequence number |
252 | * |
253 | * Returns: --- |
254 | * |
255 | * Use: Initializes a SEAL context which can be used for random |
256 | * number generation or whatever. |
257 | */ |
258 | |
259 | void seal_initctx(seal_ctx *c, seal_key *k, uint32 n) |
260 | { |
261 | c->k = k; |
262 | c->n = n; |
263 | c->l = 0; |
264 | c->r = k->r; |
265 | c->ri = 0x2000 + SEAL_R; |
266 | c->qsz = 0; |
267 | seal_reset(c); |
268 | } |
269 | |
270 | /* --- @seal_encrypt@ --- * |
271 | * |
272 | * Arguments: @seal_ctx *c@ = pointer to a SEAL context |
273 | * @const void *src@ = pointer to source data |
274 | * @void *dest@ = pointer to destination data |
275 | * @size_t sz@ = size of the data |
276 | * |
277 | * Returns: --- |
278 | * |
279 | * Use: Encrypts a block of data using SEAL. If @src@ is zero, |
280 | * @dest@ is filled with SEAL output. If @dest@ is zero, the |
281 | * SEAL generator is just spun around for a bit. This shouldn't |
282 | * be necessary, because SEAL isn't RC4. |
283 | */ |
284 | |
285 | void seal_encrypt(seal_ctx *c, const void *src, void *dest, size_t sz) |
286 | { |
287 | const octet *s = src; |
288 | octet *d = dest; |
289 | |
290 | /* --- Expect a big dollop of bytes --- */ |
291 | |
292 | if (sz > c->qsz) { |
293 | seal_key *k = c->k; |
294 | uint32 A = c->a, B = c->b, C = c->c, D = c->d; |
295 | uint32 n1 = c->n1, n2 = c->n2, n3 = c->n3, n4 = c->n4; |
296 | uint32 aa, bb, cc, dd; |
297 | unsigned j = c->i; |
298 | |
299 | /* --- Empty the queue first --- */ |
300 | |
301 | if (c->qsz) { |
302 | if (d) { |
303 | unsigned i; |
304 | octet *p = c->q + sizeof(c->q) - c->qsz; |
305 | for (i = 0; i < c->qsz; i++) |
306 | *d++ = (s ? *s++ ^ *p++ : *p++); |
307 | } |
308 | sz -= c->qsz; |
309 | } |
310 | |
311 | /* --- Main sequence --- */ |
312 | |
313 | for (;;) { |
314 | unsigned P, Q; |
315 | |
316 | /* --- Reset if we've run out of steam on this iteration --- */ |
317 | |
318 | if (j == 256) { |
319 | seal_reset(c); |
320 | A = c->a, B = c->b, C = c->c, D = c->d; |
321 | n1 = c->n1, n2 = c->n2, n3 = c->n3, n4 = c->n4; |
322 | j = 0; |
323 | } |
324 | |
325 | /* --- Make some new numbers --- */ |
326 | |
327 | P = A & 0x7fc; B += k->t[P >> 2]; A = ROR32(A, 9); B ^= A; |
328 | Q = B & 0x7fc; C ^= k->t[Q >> 2]; B = ROR32(B, 9); C += B; |
329 | P = (P + C) & 0x7fc; D += k->t[P >> 2]; C = ROR32(C, 9); D ^= C; |
330 | Q = (Q + D) & 0x7fc; A ^= k->t[Q >> 2]; D = ROR32(D, 9); A += D; |
331 | P = (P + A) & 0x7fc; B ^= k->t[P >> 2]; A = ROR32(A, 9); |
332 | Q = (Q + B) & 0x7fc; C += k->t[Q >> 2]; B = ROR32(B, 9); |
333 | P = (P + C) & 0x7fc; D ^= k->t[P >> 2]; C = ROR32(C, 9); |
334 | Q = (Q + D) & 0x7fc; A += k->t[Q >> 2]; D = ROR32(D, 9); |
335 | |
336 | /* --- Remember the output and set up the next round --- */ |
337 | |
338 | aa = B + k->s[j + 0]; |
339 | bb = C ^ k->s[j + 1]; |
340 | cc = D + k->s[j + 2]; |
341 | dd = A ^ k->s[j + 3]; |
342 | j += 4; |
343 | |
344 | if (j & 4) |
345 | A += n1, B += n2, C ^= n1, D ^= n2; |
346 | else |
347 | A += n3, B += n4, C ^= n3, D ^= n4; |
348 | |
349 | /* --- Bail out here if we need to do buffering --- */ |
350 | |
351 | if (sz < 16) |
352 | break; |
353 | |
354 | /* --- Write the next 16 bytes --- */ |
355 | |
356 | if (d) { |
357 | if (s) { |
358 | aa ^= LOAD32_L(s + 0); |
359 | bb ^= LOAD32_L(s + 4); |
360 | cc ^= LOAD32_L(s + 8); |
361 | dd ^= LOAD32_L(s + 12); |
362 | s += 16; |
363 | } |
364 | STORE32_L(d + 0, aa); |
365 | STORE32_L(d + 4, bb); |
366 | STORE32_L(d + 8, cc); |
367 | STORE32_L(d + 12, dd); |
368 | d += 16; |
369 | } |
370 | sz -= 16; |
371 | } |
372 | |
373 | /* --- Write the new queue --- */ |
374 | |
375 | STORE32_L(c->q + 0, aa); |
376 | STORE32_L(c->q + 4, bb); |
377 | STORE32_L(c->q + 8, cc); |
378 | STORE32_L(c->q + 12, dd); |
379 | c->qsz = 16; |
380 | |
381 | c->a = A; c->b = B; c->c = C; c->d = D; |
382 | c->i = j; |
383 | } |
384 | |
385 | /* --- Deal with the rest from the queue --- */ |
386 | |
387 | if (sz) { |
388 | unsigned i; |
389 | octet *p = c->q + sizeof(c->q) - c->qsz; |
390 | if (d) { |
391 | for (i = 0; i < sz; i++) |
392 | *d++ = (s ? *s++ ^ *p++ : *p++); |
393 | } |
394 | c->qsz -= sz; |
395 | } |
396 | } |
397 | |
398 | /*----- Generic cipher interface ------------------------------------------*/ |
399 | |
400 | typedef struct gctx { |
401 | gcipher c; |
402 | seal_key k; |
403 | seal_ctx cc; |
404 | } gctx; |
405 | |
406 | static const gcipher_ops gops; |
407 | |
408 | static gcipher *ginit(const void *k, size_t sz) |
409 | { |
410 | gctx *g = S_CREATE(gctx); |
411 | g->c.ops = &gops; |
412 | seal_initkey(&g->k, k, sz); |
413 | seal_initctx(&g->cc, &g->k, 0); |
414 | return (&g->c); |
415 | } |
416 | |
417 | static void gencrypt(gcipher *c, const void *s, void *t, size_t sz) |
418 | { |
419 | gctx *g = (gctx *)c; |
420 | seal_encrypt(&g->cc, s, t, sz); |
421 | } |
422 | |
423 | static void gsetiv(gcipher *c, const void *iv) |
424 | { |
425 | gctx *g = (gctx *)c; |
426 | uint32 n = *(const uint32 *)iv; |
427 | seal_initctx(&g->cc, &g->k, n); |
428 | } |
429 | |
430 | static void gdestroy(gcipher *c) |
431 | { |
432 | gctx *g = (gctx *)c; |
433 | BURN(*g); |
434 | S_DESTROY(g); |
435 | } |
436 | |
437 | static const gcipher_ops gops = { |
438 | &seal, |
439 | gencrypt, gencrypt, gdestroy, gsetiv, 0 |
440 | }; |
441 | |
442 | const gccipher seal = { |
443 | "seal", seal_keysz, 0, |
444 | ginit |
445 | }; |
446 | |
447 | /*----- Generic random number generator interface -------------------------*/ |
448 | |
449 | typedef struct grctx { |
450 | grand r; |
451 | seal_key k; |
452 | seal_ctx cc; |
453 | } grctx; |
454 | |
455 | static void grdestroy(grand *r) |
456 | { |
457 | grctx *g = (grctx *)r; |
458 | BURN(*g); |
459 | S_DESTROY(g); |
460 | } |
461 | |
462 | static int grmisc(grand *r, unsigned op, ...) |
463 | { |
464 | grctx *g = (grctx *)r; |
465 | va_list ap; |
466 | int rc = 0; |
467 | va_start(ap, op); |
468 | |
469 | switch (op) { |
470 | case GRAND_CHECK: |
471 | switch (va_arg(ap, unsigned)) { |
472 | case GRAND_CHECK: |
473 | case GRAND_SEEDINT: |
474 | case GRAND_SEEDUINT32: |
475 | case GRAND_SEEDBLOCK: |
476 | case GRAND_SEEDRAND: |
477 | rc = 1; |
478 | break; |
479 | default: |
480 | rc = 0; |
481 | break; |
482 | } |
483 | break; |
484 | case GRAND_SEEDINT: |
485 | seal_initctx(&g->cc, &g->k, va_arg(ap, int)); |
486 | break; |
487 | case GRAND_SEEDUINT32: |
488 | seal_initctx(&g->cc, &g->k, va_arg(ap, uint32)); |
489 | break; |
490 | case GRAND_SEEDBLOCK: { |
491 | const void *p = va_arg(ap, const void *); |
492 | size_t sz = va_arg(ap, size_t); |
493 | uint32 n; |
494 | if (sz >= 4) |
495 | n = LOAD32_L(p); |
496 | else { |
497 | octet buf[4] = { 0 }; |
498 | memcpy(buf, p, sz); |
499 | n = LOAD32_L(p); |
500 | } |
501 | seal_initctx(&g->cc, &g->k, n); |
502 | } break; |
503 | case GRAND_SEEDRAND: { |
504 | grand *rr = va_arg(ap, grand *); |
505 | seal_initctx(&g->cc, &g->k, rr->ops->word(rr)); |
506 | } break; |
507 | default: |
508 | GRAND_BADOP; |
509 | break; |
510 | } |
511 | |
512 | va_end(ap); |
513 | return (rc); |
514 | } |
515 | |
516 | static octet grbyte(grand *r) |
517 | { |
518 | grctx *g = (grctx *)r; |
519 | octet o; |
520 | seal_encrypt(&g->cc, 0, &o, 1); |
521 | return (o); |
522 | } |
523 | |
524 | static uint32 grword(grand *r) |
525 | { |
526 | grctx *g = (grctx *)r; |
527 | octet b[4]; |
528 | seal_encrypt(&g->cc, 0, b, 4); |
529 | return (LOAD32(b)); |
530 | } |
531 | |
532 | static void grfill(grand *r, void *p, size_t sz) |
533 | { |
534 | grctx *g = (grctx *)r; |
535 | seal_encrypt(&g->cc, 0, p, sz); |
536 | } |
537 | |
538 | static const grand_ops grops = { |
539 | "seal", |
540 | GRAND_CRYPTO, 0, |
541 | grmisc, grdestroy, |
542 | grword, grbyte, grword, grand_range, grfill |
543 | }; |
544 | |
545 | /* --- @seal_rand@ --- * |
546 | * |
547 | * Arguments: @const void *k@ = pointer to key material |
548 | * @size_t sz@ = size of key material |
549 | * @uint32 n@ = sequence number |
550 | * |
551 | * Returns: Pointer to generic random number generator interface. |
552 | * |
553 | * Use: Creates a random number interface wrapper around a SEAL |
554 | * pseudorandom function. |
555 | */ |
556 | |
557 | grand *seal_rand(const void *k, size_t sz, uint32 n) |
558 | { |
559 | grctx *g = S_CREATE(grctx); |
560 | g->r.ops = &grops; |
561 | seal_initkey(&g->k, k, sz); |
562 | seal_initctx(&g->cc, &g->k, n); |
563 | return (&g->r); |
564 | } |
565 | |
566 | /*----- Test rig ----------------------------------------------------------*/ |
567 | |
568 | #ifdef TEST_RIG |
569 | |
570 | #include <string.h> |
571 | |
572 | #include <mLib/testrig.h> |
573 | |
574 | static int verify(dstr *v) |
575 | { |
576 | seal_key k; |
577 | seal_ctx c; |
578 | uint32 n = *(uint32 *)v[1].buf; |
579 | dstr d = DSTR_INIT; |
580 | dstr z = DSTR_INIT; |
581 | int i; |
582 | int ok = 1; |
583 | |
584 | DENSURE(&d, v[2].len); |
585 | DENSURE(&z, v[2].len); |
586 | memset(z.buf, 0, v[2].len); |
587 | z.len = d.len = v[2].len; |
588 | seal_initkey(&k, v[0].buf, v[0].len); |
589 | |
590 | for (i = 0; i < v[2].len; i++) { |
591 | seal_initctx(&c, &k, n); |
592 | seal_encrypt(&c, 0, d.buf, i); |
593 | seal_encrypt(&c, z.buf, d.buf + i, d.len - i); |
594 | if (memcmp(d.buf, v[2].buf, d.len) != 0) { |
595 | ok = 0; |
596 | printf("*** seal failure\n"); |
597 | printf("*** k = "); type_hex.dump(&v[0], stdout); putchar('\n'); |
598 | printf("*** n = %08lx\n", (unsigned long)n); |
599 | printf("*** i = %i\n", i); |
600 | printf("*** expected = "); type_hex.dump(&v[2], stdout); putchar('\n'); |
601 | printf("*** computed = "); type_hex.dump(&d, stdout); putchar('\n'); |
602 | } |
603 | } |
604 | |
605 | dstr_destroy(&d); |
606 | dstr_destroy(&z); |
607 | |
608 | return (ok); |
609 | } |
610 | |
611 | static test_chunk defs[] = { |
612 | { "seal", verify, { &type_hex, &type_uint32, &type_hex, 0 } }, |
613 | { 0, 0, { 0 } } |
614 | }; |
615 | |
616 | int main(int argc, char *argv[]) |
617 | { |
618 | test_run(argc, argv, defs, SRCDIR"/tests/seal"); |
619 | return (0); |
620 | } |
621 | |
622 | #endif |
623 | |
624 | /*----- That's all, folks -------------------------------------------------*/ |