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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: tlsprf.c,v 1.2 2001/04/06 22:05:53 mdw Exp $ |
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4 | * |
5 | * The TLS pseudo-random function |
6 | * |
7 | * (c) 2001 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: tlsprf.c,v $ |
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33 | * Revision 1.2 2001/04/06 22:05:53 mdw |
34 | * Change dummy names in grand objects so that they say what sort of thing |
35 | * they are. |
36 | * |
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37 | * Revision 1.1 2001/04/04 20:10:52 mdw |
38 | * Add support for the TLS pseudo-random function. |
39 | * |
40 | */ |
41 | |
42 | /*----- Header files ------------------------------------------------------*/ |
43 | |
44 | #include <mLib/alloc.h> |
45 | #include <mLib/dstr.h> |
46 | #include <mLib/sub.h> |
47 | |
48 | #include "arena.h" |
49 | #include "gmac.h" |
50 | #include "grand.h" |
51 | #include "paranoia.h" |
52 | #include "tlsprf.h" |
53 | |
54 | /*----- The data expansion function ---------------------------------------*/ |
55 | |
56 | /* --- @tlsdx_init@ --- * |
57 | * |
58 | * Arguments: @tlsdx_ctx *c@ = pointer to a context |
59 | * @gmac *m@ = pointer to a generic MAC instance |
60 | * @const void *sd@ = pointer to the seed block |
61 | * @size_t sdsz@ = size of the seed block |
62 | * |
63 | * Returns: --- |
64 | * |
65 | * Use: Initializes a context for the TLS data expansion function. |
66 | * This doesn't take ownership of the MAC instance or the seed |
67 | * memory, nor does it allocate copies. |
68 | */ |
69 | |
70 | void tlsdx_init(tlsdx_ctx *c, gmac *m, const void *sd, size_t sdsz) |
71 | { |
72 | c->k = m; |
73 | c->hashsz = c->k->ops->c->hashsz; |
74 | c->sd = sd; c->sdsz = sdsz; |
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75 | |
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76 | c->i = c->k->ops->init(c->k); |
77 | c->i->ops->hash(c->i, sd, sdsz); |
78 | c->ai = c->i->ops->done(c->i, 0); |
79 | c->o = c->k->ops->init(c->k); |
80 | c->o->ops->hash(c->o, c->ai, c->hashsz); |
81 | c->o->ops->hash(c->o, sd, sdsz); |
82 | c->p = c->o->ops->done(c->o, 0); |
83 | c->sz = c->hashsz; |
84 | } |
85 | |
86 | /* --- @tlsdx_encrypt@ --- * |
87 | * |
88 | * Arguments: @tlsdx_ctx *c@ = pointer to a context |
89 | * @const void *src@ = pointer to source data |
90 | * @void *dest@ = pointer to destination buffer |
91 | * @size_t sz@ = size of buffer |
92 | * |
93 | * Returns: --- |
94 | * |
95 | * Use: Encrypts data using the TLS data expansion function. If the |
96 | * destination pointer is null, the generator is spun and no |
97 | * output is produced; if the source pointer is null, raw output |
98 | * from the generator is written; otherwise, the source data is |
99 | * XORed with the generator output. |
100 | */ |
101 | |
102 | void tlsdx_encrypt(tlsdx_ctx *c, const void *src, void *dest, size_t sz) |
103 | { |
104 | const octet *s = src; |
105 | octet *d = dest; |
106 | ghash *h; |
107 | size_t i; |
108 | size_t n; |
109 | |
110 | while (sz) { |
111 | if (c->sz) |
112 | n = c->sz; |
113 | else { |
114 | h = c->k->ops->init(c->k); |
115 | h->ops->hash(h, c->ai, c->hashsz); |
116 | c->ai = h->ops->done(h, 0); |
117 | c->i->ops->destroy(c->i); |
118 | c->i = h; |
119 | c->o->ops->destroy(c->o); |
120 | h = c->o = c->k->ops->init(c->k); |
121 | h->ops->hash(h, c->ai, c->hashsz); |
122 | h->ops->hash(h, c->sd, c->sdsz); |
123 | c->p = h->ops->done(h, 0); |
124 | c->sz = n = c->hashsz; |
125 | } |
126 | if (n > sz) |
127 | n = sz; |
128 | if (d) { |
129 | if (!s) |
130 | memcpy(d, c->p, n); |
131 | else { |
132 | for (i = 0; i < n; i++) d[i] = s[i] ^ c->p[i]; |
133 | s += n; |
134 | } |
135 | d += n; |
136 | } |
137 | c->p += n; |
138 | c->sz -= n; |
139 | sz -= n; |
140 | } |
141 | } |
142 | |
143 | /* --- @tlsdx_free@ --- * |
144 | * |
145 | * Arguments: @tlsdx_ctx *c@ = pointer to the context block |
146 | * |
147 | * Returns: --- |
148 | * |
149 | * Use: Frees a context for the TLS data expansion function |
150 | */ |
151 | |
152 | void tlsdx_free(tlsdx_ctx *c) |
153 | { |
154 | c->i->ops->destroy(c->i); |
155 | c->o->ops->destroy(c->o); |
156 | } |
157 | |
158 | /* --- Generic random number generator --- */ |
159 | |
160 | typedef struct dx_grctx { |
161 | grand r; |
162 | grand_ops ops; |
163 | tlsdx_ctx dx; |
164 | } dx_grctx; |
165 | |
166 | static void dx_grdestroy(grand *r) |
167 | { |
168 | dx_grctx *g = (dx_grctx *)r; |
169 | xfree((char *)g->ops.name); |
170 | xfree((octet *)g->dx.sd); |
171 | g->dx.k->ops->destroy(g->dx.k); |
172 | tlsdx_free(&g->dx); |
173 | BURN(*g); |
174 | S_DESTROY(g); |
175 | } |
176 | |
177 | static void dx_seed(dx_grctx *g, const void *p, size_t sz) |
178 | { |
179 | octet *q; |
180 | xfree((octet *)g->dx.sd); |
181 | g->dx.sd = q = xmalloc(sz); |
182 | memcpy(q, p, sz); |
183 | g->dx.sdsz = sz; |
184 | } |
185 | |
186 | static int dx_grmisc(grand *r, unsigned op, ...) |
187 | { |
188 | dx_grctx *g = (dx_grctx *)r; |
189 | va_list ap; |
190 | int rc = 0; |
191 | uint32 i; |
192 | octet buf[4]; |
193 | va_start(ap, op); |
194 | |
195 | switch (op) { |
196 | case GRAND_CHECK: |
197 | switch (va_arg(ap, unsigned)) { |
198 | case GRAND_CHECK: |
199 | case GRAND_SEEDINT: |
200 | case GRAND_SEEDUINT32: |
201 | case GRAND_SEEDBLOCK: |
202 | case GRAND_SEEDRAND: |
203 | rc = 1; |
204 | break; |
205 | default: |
206 | rc = 0; |
207 | break; |
208 | } |
209 | break; |
210 | case GRAND_SEEDINT: |
211 | i = va_arg(ap, unsigned); |
212 | STORE32(buf, i); |
213 | dx_seed(g, buf, sizeof(buf)); |
214 | break; |
215 | case GRAND_SEEDUINT32: |
216 | i = va_arg(ap, uint32); |
217 | STORE32(buf, i); |
218 | dx_seed(g, buf, sizeof(buf)); |
219 | break; |
220 | case GRAND_SEEDBLOCK: { |
221 | const void *p = va_arg(ap, const void *); |
222 | size_t sz = va_arg(ap, size_t); |
223 | dx_seed(g, p, sz); |
224 | } break; |
225 | case GRAND_SEEDRAND: { |
226 | grand *rr = va_arg(ap, grand *); |
227 | octet buf[16]; |
228 | rr->ops->fill(rr, buf, sizeof(buf)); |
229 | dx_seed(g, buf, sizeof(buf)); |
230 | } break; |
231 | default: |
232 | GRAND_BADOP; |
233 | break; |
234 | } |
235 | |
236 | va_end(ap); |
237 | return (rc); |
238 | } |
239 | |
240 | static octet dx_grbyte(grand *r) |
241 | { |
242 | dx_grctx *g = (dx_grctx *)r; |
243 | octet o; |
244 | tlsdx_encrypt(&g->dx, 0, &o, 1); |
245 | return (o); |
246 | } |
247 | |
248 | static uint32 dx_grword(grand *r) |
249 | { |
250 | dx_grctx *g = (dx_grctx *)r; |
251 | octet b[4]; |
252 | tlsdx_encrypt(&g->dx, 0, &b, sizeof(b)); |
253 | return (LOAD32(b)); |
254 | } |
255 | |
256 | static void dx_grfill(grand *r, void *p, size_t sz) |
257 | { |
258 | dx_grctx *g = (dx_grctx *)r; |
259 | tlsdx_encrypt(&g->dx, 0, p, sz); |
260 | } |
261 | |
262 | static const grand_ops dx_grops = { |
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263 | "<tlsdx-dummy>", |
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264 | GRAND_CRYPTO, 0, |
265 | dx_grmisc, dx_grdestroy, |
266 | dx_grword, dx_grbyte, dx_grword, grand_range, dx_grfill |
267 | }; |
268 | |
269 | /* ---@tlsdx_rand@ --- * |
270 | * |
271 | * Arguments: @const gcmac *mc@ = MAC function to use |
272 | * @const void *k@ = pointer to the key material |
273 | * @size_t ksz@ = size of the key material |
274 | * @const void *sd@ = pointer to the seed material |
275 | * @size_t sdsz@ = size of the seed material |
276 | * |
277 | * Returns: Pointer to generic random number generator interface. |
278 | * |
279 | * Use: Creates a generic generator which does TLS data expansion. |
280 | */ |
281 | |
282 | grand *tlsdx_rand(const gcmac *mc, const void *k, size_t ksz, |
283 | const void *sd, size_t sdsz) |
284 | { |
285 | dx_grctx *g = S_CREATE(dx_grctx); |
286 | dstr d = DSTR_INIT; |
287 | gmac *m = mc->key(k, ksz); |
288 | octet *q = xmalloc(sdsz); |
289 | memcpy(q, sd, sdsz); |
290 | dstr_putf(&d, "tlsdx(%s)", mc->name); |
291 | g->ops = dx_grops; |
292 | g->ops.name = xstrdup(d.buf); |
293 | g->r.ops = &g->ops; |
294 | dstr_destroy(&d); |
295 | tlsdx_init(&g->dx, m, q, sdsz); |
296 | return (&g->r); |
297 | } |
298 | |
299 | /* --- The actual very paranoid PRF ---------------------------------------*/ |
300 | |
301 | /* --- @tlsprf_init@ --- * |
302 | * |
303 | * Arguments: @tlsprf_ctx *c@ = pointer to context block |
304 | * @const gcmac *mcx, *mcy@ = left and right MAC functions |
305 | * @const void *k@ = pointer to the key material |
306 | * @size_t ksz@ = size of the key material |
307 | * @const void *sd@ = pointer to the seed material |
308 | * @size_t sdsz@ = size of the seed material |
309 | * |
310 | * Returns: --- |
311 | * |
312 | * Use: Initializes a TLS PRF context. |
313 | */ |
314 | |
315 | void tlsprf_init(tlsprf_ctx *c, const gcmac *mcx, const gcmac *mcy, |
316 | const void *k, size_t ksz, const void *sd, size_t sdsz) |
317 | { |
318 | size_t n = (ksz + 1)/2; |
319 | const octet *kk = k; |
320 | tlsdx_init(&c->px, mcx->key(kk, n), sd, sdsz); |
321 | tlsdx_init(&c->py, mcy->key(kk + ksz - n, n), sd, sdsz); |
322 | } |
323 | |
324 | /* --- @tlsprf_encrypt@ --- * |
325 | * |
326 | * Arguments: @tlsprf_ctx *c@ = pointer to a context |
327 | * @const void *src@ = pointer to source data |
328 | * @void *dest@ = pointer to destination buffer |
329 | * @size_t sz@ = size of buffer |
330 | * |
331 | * Returns: --- |
332 | * |
333 | * Use: Encrypts data using the TLS pseudo-random function. If the |
334 | * destination pointer is null, the generator is spun and no |
335 | * output is produced; if the source pointer is null, raw output |
336 | * from the generator is written; otherwise, the source data is |
337 | * XORed with the generator output. |
338 | */ |
339 | |
340 | void tlsprf_encrypt(tlsprf_ctx *c, const void *src, void *dest, size_t sz) |
341 | { |
342 | tlsdx_encrypt(&c->px, src, dest, sz); |
343 | tlsdx_encrypt(&c->py, dest, dest, sz); |
344 | } |
345 | |
346 | /* --- @tlsprf_free@ --- * |
347 | * |
348 | * Arguments: @tlsprf_ctx *c@ = pointer to a context |
349 | * |
350 | * Returns: --- |
351 | * |
352 | * Use: Frees a TLS PRF context. |
353 | */ |
354 | |
355 | void tlsprf_free(tlsprf_ctx *c) |
356 | { |
357 | c->px.k->ops->destroy(c->px.k); |
358 | c->py.k->ops->destroy(c->py.k); |
359 | tlsdx_free(&c->px); |
360 | tlsdx_free(&c->py); |
361 | } |
362 | |
363 | /* --- Generic random number generator --- */ |
364 | |
365 | typedef struct prf_grctx { |
366 | grand r; |
367 | grand_ops ops; |
368 | tlsprf_ctx prf; |
369 | } prf_grctx; |
370 | |
371 | static void prf_grdestroy(grand *r) |
372 | { |
373 | prf_grctx *g = (prf_grctx *)r; |
374 | xfree((char *)g->ops.name); |
375 | xfree((octet *)g->prf.px.sd); |
376 | tlsprf_free(&g->prf); |
377 | BURN(*g); |
378 | S_DESTROY(g); |
379 | } |
380 | |
381 | static void prf_seed(prf_grctx *g, const void *p, size_t sz) |
382 | { |
383 | octet *q; |
384 | |
385 | xfree((octet *)g->prf.px.sz); |
386 | g->prf.px.sd = g->prf.py.sd = q = xmalloc(sz); |
387 | memcpy(q, p, sz); |
388 | g->prf.px.sdsz = g->prf.py.sdsz = sz; |
389 | } |
390 | |
391 | static int prf_grmisc(grand *r, unsigned op, ...) |
392 | { |
393 | prf_grctx *g = (prf_grctx *)r; |
394 | va_list ap; |
395 | int rc = 0; |
396 | uint32 i; |
397 | octet buf[4]; |
398 | va_start(ap, op); |
399 | |
400 | switch (op) { |
401 | case GRAND_CHECK: |
402 | switch (va_arg(ap, unsigned)) { |
403 | case GRAND_CHECK: |
404 | case GRAND_SEEDINT: |
405 | case GRAND_SEEDUINT32: |
406 | case GRAND_SEEDBLOCK: |
407 | case GRAND_SEEDRAND: |
408 | rc = 1; |
409 | break; |
410 | default: |
411 | rc = 0; |
412 | break; |
413 | } |
414 | break; |
415 | case GRAND_SEEDINT: |
416 | i = va_arg(ap, unsigned); |
417 | STORE32(buf, i); |
418 | prf_seed(g, buf, sizeof(buf)); |
419 | break; |
420 | case GRAND_SEEDUINT32: |
421 | i = va_arg(ap, uint32); |
422 | STORE32(buf, i); |
423 | prf_seed(g, buf, sizeof(buf)); |
424 | break; |
425 | case GRAND_SEEDBLOCK: { |
426 | const void *p = va_arg(ap, const void *); |
427 | size_t sz = va_arg(ap, size_t); |
428 | prf_seed(g, p, sz); |
429 | } break; |
430 | case GRAND_SEEDRAND: { |
431 | grand *rr = va_arg(ap, grand *); |
432 | octet buf[16]; |
433 | rr->ops->fill(rr, buf, sizeof(buf)); |
434 | prf_seed(g, buf, sizeof(buf)); |
435 | } break; |
436 | default: |
437 | GRAND_BADOP; |
438 | break; |
439 | } |
440 | |
441 | va_end(ap); |
442 | return (rc); |
443 | } |
444 | |
445 | static octet prf_grbyte(grand *r) |
446 | { |
447 | prf_grctx *g = (prf_grctx *)r; |
448 | octet o; |
449 | tlsprf_encrypt(&g->prf, 0, &o, 1); |
450 | return (o); |
451 | } |
452 | |
453 | static uint32 prf_grword(grand *r) |
454 | { |
455 | prf_grctx *g = (prf_grctx *)r; |
456 | octet b[4]; |
457 | tlsprf_encrypt(&g->prf, 0, &b, sizeof(b)); |
458 | return (LOAD32(b)); |
459 | } |
460 | |
461 | static void prf_grfill(grand *r, void *p, size_t sz) |
462 | { |
463 | prf_grctx *g = (prf_grctx *)r; |
464 | tlsprf_encrypt(&g->prf, 0, p, sz); |
465 | } |
466 | |
467 | static const grand_ops prf_grops = { |
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468 | "<tlsprf-dummy>", |
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469 | GRAND_CRYPTO, 0, |
470 | prf_grmisc, prf_grdestroy, |
471 | prf_grword, prf_grbyte, prf_grword, grand_range, prf_grfill |
472 | }; |
473 | |
474 | /* ---@tlsprf_rand@ --- * |
475 | * |
476 | * Arguments: @const gcmac *mcx, *mcy@ = MAC function to use |
477 | * @const void *k@ = pointer to the key material |
478 | * @size_t ksz@ = size of the key material |
479 | * @const void *sd@ = pointer to the seed material |
480 | * @size_t sdsz@ = size of the seed material |
481 | * |
482 | * Returns: Pointer to generic random number generator interface. |
483 | * |
484 | * Use: Creates a generic generator which does TLS data expansion. |
485 | */ |
486 | |
487 | grand *tlsprf_rand(const gcmac *mcx, const gcmac *mcy, |
488 | const void *k, size_t ksz, const void *sd, size_t sdsz) |
489 | { |
490 | prf_grctx *g = S_CREATE(prf_grctx); |
491 | dstr d = DSTR_INIT; |
492 | octet *q = xmalloc(sdsz); |
493 | memcpy(q, sd, sdsz); |
494 | dstr_putf(&d, "tlsprf(%s,%s)", mcx->name, mcy->name); |
495 | g->ops = prf_grops; |
496 | g->ops.name = xstrdup(d.buf); |
497 | g->r.ops = &g->ops; |
498 | dstr_destroy(&d); |
499 | tlsprf_init(&g->prf, mcx, mcy, k, ksz, q, sdsz); |
500 | return (&g->r); |
501 | } |
502 | |
503 | /*----- Test rig ----------------------------------------------------------*/ |
504 | |
505 | #ifdef TEST_RIG |
506 | |
507 | #include <stdio.h> |
508 | #include <string.h> |
509 | |
510 | #include <mLib/quis.h> |
511 | #include <mLib/testrig.h> |
512 | |
513 | #include "sha-hmac.h" |
514 | #include "md5-hmac.h" |
515 | |
516 | static int v_generate(dstr *v) |
517 | { |
518 | grand *g; |
519 | dstr d = DSTR_INIT; |
520 | int ok = 1; |
521 | |
522 | g = tlsprf_rand(&md5_hmac, &sha_hmac, |
523 | v[0].buf, v[0].len, v[1].buf, v[1].len); |
524 | dstr_ensure(&d, v[2].len); |
525 | d.len = v[2].len; |
526 | g->ops->fill(g, d.buf, d.len); |
527 | g->ops->destroy(g); |
528 | if (memcmp(v[2].buf, d.buf, d.len) != 0) { |
529 | ok = 0; |
530 | printf("\nfail tlsprf:" |
531 | "\n\tkey = "); |
532 | type_hex.dump(&v[0], stdout); |
533 | printf("\n\tseed = "); type_hex.dump(&v[1], stdout); |
534 | printf("\n\texpected = "); type_hex.dump(&v[2], stdout); |
535 | printf("\n\tcalculated = "); type_hex.dump(&d, stdout); |
536 | putchar('\n'); |
537 | } |
538 | return (ok); |
539 | } |
540 | |
541 | static test_chunk defs[] = { |
542 | { "tlsprf", v_generate, { &type_hex, &type_hex, &type_hex, 0 } }, |
543 | { 0, 0, { 0 } } |
544 | }; |
545 | |
546 | int main(int argc, char *argv[]) |
547 | { |
548 | test_run(argc, argv, defs, SRCDIR"/tests/tlsprf"); |
549 | return (0); |
550 | } |
551 | |
552 | #endif |
553 | |
554 | /*----- That's all, folks -------------------------------------------------*/ |