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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: tlsprf.c,v 1.3 2004/04/08 01:36:15 mdw Exp $ |
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4 | * |
5 | * The TLS pseudo-random function |
6 | * |
7 | * (c) 2001 Straylight/Edgeware |
8 | */ |
9 | |
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10 | /*----- Licensing notice --------------------------------------------------* |
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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. |
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18 | * |
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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. |
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23 | * |
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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 | |
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30 | /*----- Header files ------------------------------------------------------*/ |
31 | |
32 | #include <mLib/alloc.h> |
33 | #include <mLib/dstr.h> |
34 | #include <mLib/sub.h> |
35 | |
36 | #include "arena.h" |
37 | #include "gmac.h" |
38 | #include "grand.h" |
39 | #include "paranoia.h" |
40 | #include "tlsprf.h" |
41 | |
42 | /*----- The data expansion function ---------------------------------------*/ |
43 | |
44 | /* --- @tlsdx_init@ --- * |
45 | * |
46 | * Arguments: @tlsdx_ctx *c@ = pointer to a context |
47 | * @gmac *m@ = pointer to a generic MAC instance |
48 | * @const void *sd@ = pointer to the seed block |
49 | * @size_t sdsz@ = size of the seed block |
50 | * |
51 | * Returns: --- |
52 | * |
53 | * Use: Initializes a context for the TLS data expansion function. |
54 | * This doesn't take ownership of the MAC instance or the seed |
55 | * memory, nor does it allocate copies. |
56 | */ |
57 | |
58 | void tlsdx_init(tlsdx_ctx *c, gmac *m, const void *sd, size_t sdsz) |
59 | { |
60 | c->k = m; |
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61 | c->hashsz = GM_CLASS(c->k)->hashsz; |
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62 | c->sd = sd; c->sdsz = sdsz; |
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63 | |
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64 | c->i = GM_INIT(c->k); |
65 | GH_HASH(c->i, sd, sdsz); |
66 | c->ai = GH_DONE(c->i, 0); |
67 | c->o = GM_INIT(c->k); |
68 | GH_HASH(c->o, c->ai, c->hashsz); |
69 | GH_HASH(c->o, sd, sdsz); |
70 | c->p = GH_DONE(c->o, 0); |
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71 | c->sz = c->hashsz; |
72 | } |
73 | |
74 | /* --- @tlsdx_encrypt@ --- * |
75 | * |
76 | * Arguments: @tlsdx_ctx *c@ = pointer to a context |
77 | * @const void *src@ = pointer to source data |
78 | * @void *dest@ = pointer to destination buffer |
79 | * @size_t sz@ = size of buffer |
80 | * |
81 | * Returns: --- |
82 | * |
83 | * Use: Encrypts data using the TLS data expansion function. If the |
84 | * destination pointer is null, the generator is spun and no |
85 | * output is produced; if the source pointer is null, raw output |
86 | * from the generator is written; otherwise, the source data is |
87 | * XORed with the generator output. |
88 | */ |
89 | |
90 | void tlsdx_encrypt(tlsdx_ctx *c, const void *src, void *dest, size_t sz) |
91 | { |
92 | const octet *s = src; |
93 | octet *d = dest; |
94 | ghash *h; |
95 | size_t i; |
96 | size_t n; |
97 | |
98 | while (sz) { |
99 | if (c->sz) |
100 | n = c->sz; |
101 | else { |
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102 | h = GM_INIT(c->k); |
103 | GH_HASH(h, c->ai, c->hashsz); |
104 | c->ai = GH_DONE(h, 0); |
105 | GH_DESTROY(c->i); |
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106 | c->i = h; |
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107 | GH_DESTROY(c->o); |
108 | h = c->o = GM_INIT(c->k); |
109 | GH_HASH(h, c->ai, c->hashsz); |
110 | GH_HASH(h, c->sd, c->sdsz); |
111 | c->p = GH_DONE(h, 0); |
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112 | c->sz = n = c->hashsz; |
113 | } |
114 | if (n > sz) |
115 | n = sz; |
116 | if (d) { |
117 | if (!s) |
118 | memcpy(d, c->p, n); |
119 | else { |
120 | for (i = 0; i < n; i++) d[i] = s[i] ^ c->p[i]; |
121 | s += n; |
122 | } |
123 | d += n; |
124 | } |
125 | c->p += n; |
126 | c->sz -= n; |
127 | sz -= n; |
128 | } |
129 | } |
130 | |
131 | /* --- @tlsdx_free@ --- * |
132 | * |
133 | * Arguments: @tlsdx_ctx *c@ = pointer to the context block |
134 | * |
135 | * Returns: --- |
136 | * |
137 | * Use: Frees a context for the TLS data expansion function |
138 | */ |
139 | |
140 | void tlsdx_free(tlsdx_ctx *c) |
141 | { |
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142 | GH_DESTROY(c->i); |
143 | GH_DESTROY(c->o); |
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144 | } |
145 | |
146 | /* --- Generic random number generator --- */ |
147 | |
148 | typedef struct dx_grctx { |
149 | grand r; |
150 | grand_ops ops; |
151 | tlsdx_ctx dx; |
152 | } dx_grctx; |
153 | |
154 | static void dx_grdestroy(grand *r) |
155 | { |
156 | dx_grctx *g = (dx_grctx *)r; |
157 | xfree((char *)g->ops.name); |
158 | xfree((octet *)g->dx.sd); |
159 | g->dx.k->ops->destroy(g->dx.k); |
160 | tlsdx_free(&g->dx); |
161 | BURN(*g); |
162 | S_DESTROY(g); |
163 | } |
164 | |
165 | static void dx_seed(dx_grctx *g, const void *p, size_t sz) |
166 | { |
167 | octet *q; |
168 | xfree((octet *)g->dx.sd); |
169 | g->dx.sd = q = xmalloc(sz); |
170 | memcpy(q, p, sz); |
171 | g->dx.sdsz = sz; |
172 | } |
173 | |
174 | static int dx_grmisc(grand *r, unsigned op, ...) |
175 | { |
176 | dx_grctx *g = (dx_grctx *)r; |
177 | va_list ap; |
178 | int rc = 0; |
179 | uint32 i; |
180 | octet buf[4]; |
181 | va_start(ap, op); |
182 | |
183 | switch (op) { |
184 | case GRAND_CHECK: |
185 | switch (va_arg(ap, unsigned)) { |
186 | case GRAND_CHECK: |
187 | case GRAND_SEEDINT: |
188 | case GRAND_SEEDUINT32: |
189 | case GRAND_SEEDBLOCK: |
190 | case GRAND_SEEDRAND: |
191 | rc = 1; |
192 | break; |
193 | default: |
194 | rc = 0; |
195 | break; |
196 | } |
197 | break; |
198 | case GRAND_SEEDINT: |
199 | i = va_arg(ap, unsigned); |
200 | STORE32(buf, i); |
201 | dx_seed(g, buf, sizeof(buf)); |
202 | break; |
203 | case GRAND_SEEDUINT32: |
204 | i = va_arg(ap, uint32); |
205 | STORE32(buf, i); |
206 | dx_seed(g, buf, sizeof(buf)); |
207 | break; |
208 | case GRAND_SEEDBLOCK: { |
209 | const void *p = va_arg(ap, const void *); |
210 | size_t sz = va_arg(ap, size_t); |
211 | dx_seed(g, p, sz); |
212 | } break; |
213 | case GRAND_SEEDRAND: { |
214 | grand *rr = va_arg(ap, grand *); |
215 | octet buf[16]; |
216 | rr->ops->fill(rr, buf, sizeof(buf)); |
217 | dx_seed(g, buf, sizeof(buf)); |
218 | } break; |
219 | default: |
220 | GRAND_BADOP; |
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221 | break; |
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222 | } |
223 | |
224 | va_end(ap); |
225 | return (rc); |
226 | } |
227 | |
228 | static octet dx_grbyte(grand *r) |
229 | { |
230 | dx_grctx *g = (dx_grctx *)r; |
231 | octet o; |
232 | tlsdx_encrypt(&g->dx, 0, &o, 1); |
233 | return (o); |
234 | } |
235 | |
236 | static uint32 dx_grword(grand *r) |
237 | { |
238 | dx_grctx *g = (dx_grctx *)r; |
239 | octet b[4]; |
240 | tlsdx_encrypt(&g->dx, 0, &b, sizeof(b)); |
241 | return (LOAD32(b)); |
242 | } |
243 | |
244 | static void dx_grfill(grand *r, void *p, size_t sz) |
245 | { |
246 | dx_grctx *g = (dx_grctx *)r; |
247 | tlsdx_encrypt(&g->dx, 0, p, sz); |
248 | } |
249 | |
250 | static const grand_ops dx_grops = { |
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251 | "<tlsdx-dummy>", |
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252 | GRAND_CRYPTO, 0, |
253 | dx_grmisc, dx_grdestroy, |
254 | dx_grword, dx_grbyte, dx_grword, grand_range, dx_grfill |
255 | }; |
256 | |
257 | /* ---@tlsdx_rand@ --- * |
258 | * |
259 | * Arguments: @const gcmac *mc@ = MAC function to use |
260 | * @const void *k@ = pointer to the key material |
261 | * @size_t ksz@ = size of the key material |
262 | * @const void *sd@ = pointer to the seed material |
263 | * @size_t sdsz@ = size of the seed material |
264 | * |
265 | * Returns: Pointer to generic random number generator interface. |
266 | * |
267 | * Use: Creates a generic generator which does TLS data expansion. |
268 | */ |
269 | |
270 | grand *tlsdx_rand(const gcmac *mc, const void *k, size_t ksz, |
271 | const void *sd, size_t sdsz) |
272 | { |
273 | dx_grctx *g = S_CREATE(dx_grctx); |
274 | dstr d = DSTR_INIT; |
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275 | gmac *m = GM_KEY(mc, k, ksz); |
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276 | octet *q = xmalloc(sdsz); |
277 | memcpy(q, sd, sdsz); |
278 | dstr_putf(&d, "tlsdx(%s)", mc->name); |
279 | g->ops = dx_grops; |
280 | g->ops.name = xstrdup(d.buf); |
281 | g->r.ops = &g->ops; |
282 | dstr_destroy(&d); |
283 | tlsdx_init(&g->dx, m, q, sdsz); |
284 | return (&g->r); |
285 | } |
286 | |
287 | /* --- The actual very paranoid PRF ---------------------------------------*/ |
288 | |
289 | /* --- @tlsprf_init@ --- * |
290 | * |
291 | * Arguments: @tlsprf_ctx *c@ = pointer to context block |
292 | * @const gcmac *mcx, *mcy@ = left and right MAC functions |
293 | * @const void *k@ = pointer to the key material |
294 | * @size_t ksz@ = size of the key material |
295 | * @const void *sd@ = pointer to the seed material |
296 | * @size_t sdsz@ = size of the seed material |
297 | * |
298 | * Returns: --- |
299 | * |
300 | * Use: Initializes a TLS PRF context. |
301 | */ |
302 | |
303 | void tlsprf_init(tlsprf_ctx *c, const gcmac *mcx, const gcmac *mcy, |
304 | const void *k, size_t ksz, const void *sd, size_t sdsz) |
305 | { |
306 | size_t n = (ksz + 1)/2; |
307 | const octet *kk = k; |
308 | tlsdx_init(&c->px, mcx->key(kk, n), sd, sdsz); |
309 | tlsdx_init(&c->py, mcy->key(kk + ksz - n, n), sd, sdsz); |
310 | } |
311 | |
312 | /* --- @tlsprf_encrypt@ --- * |
313 | * |
314 | * Arguments: @tlsprf_ctx *c@ = pointer to a context |
315 | * @const void *src@ = pointer to source data |
316 | * @void *dest@ = pointer to destination buffer |
317 | * @size_t sz@ = size of buffer |
318 | * |
319 | * Returns: --- |
320 | * |
321 | * Use: Encrypts data using the TLS pseudo-random function. If the |
322 | * destination pointer is null, the generator is spun and no |
323 | * output is produced; if the source pointer is null, raw output |
324 | * from the generator is written; otherwise, the source data is |
325 | * XORed with the generator output. |
326 | */ |
327 | |
328 | void tlsprf_encrypt(tlsprf_ctx *c, const void *src, void *dest, size_t sz) |
329 | { |
330 | tlsdx_encrypt(&c->px, src, dest, sz); |
331 | tlsdx_encrypt(&c->py, dest, dest, sz); |
332 | } |
333 | |
334 | /* --- @tlsprf_free@ --- * |
335 | * |
336 | * Arguments: @tlsprf_ctx *c@ = pointer to a context |
337 | * |
338 | * Returns: --- |
339 | * |
340 | * Use: Frees a TLS PRF context. |
341 | */ |
342 | |
343 | void tlsprf_free(tlsprf_ctx *c) |
344 | { |
345 | c->px.k->ops->destroy(c->px.k); |
346 | c->py.k->ops->destroy(c->py.k); |
347 | tlsdx_free(&c->px); |
348 | tlsdx_free(&c->py); |
349 | } |
350 | |
351 | /* --- Generic random number generator --- */ |
352 | |
353 | typedef struct prf_grctx { |
354 | grand r; |
355 | grand_ops ops; |
356 | tlsprf_ctx prf; |
357 | } prf_grctx; |
358 | |
359 | static void prf_grdestroy(grand *r) |
360 | { |
361 | prf_grctx *g = (prf_grctx *)r; |
362 | xfree((char *)g->ops.name); |
363 | xfree((octet *)g->prf.px.sd); |
364 | tlsprf_free(&g->prf); |
365 | BURN(*g); |
366 | S_DESTROY(g); |
367 | } |
368 | |
369 | static void prf_seed(prf_grctx *g, const void *p, size_t sz) |
370 | { |
371 | octet *q; |
372 | |
373 | xfree((octet *)g->prf.px.sz); |
374 | g->prf.px.sd = g->prf.py.sd = q = xmalloc(sz); |
375 | memcpy(q, p, sz); |
376 | g->prf.px.sdsz = g->prf.py.sdsz = sz; |
377 | } |
378 | |
379 | static int prf_grmisc(grand *r, unsigned op, ...) |
380 | { |
381 | prf_grctx *g = (prf_grctx *)r; |
382 | va_list ap; |
383 | int rc = 0; |
384 | uint32 i; |
385 | octet buf[4]; |
386 | va_start(ap, op); |
387 | |
388 | switch (op) { |
389 | case GRAND_CHECK: |
390 | switch (va_arg(ap, unsigned)) { |
391 | case GRAND_CHECK: |
392 | case GRAND_SEEDINT: |
393 | case GRAND_SEEDUINT32: |
394 | case GRAND_SEEDBLOCK: |
395 | case GRAND_SEEDRAND: |
396 | rc = 1; |
397 | break; |
398 | default: |
399 | rc = 0; |
400 | break; |
401 | } |
402 | break; |
403 | case GRAND_SEEDINT: |
404 | i = va_arg(ap, unsigned); |
405 | STORE32(buf, i); |
406 | prf_seed(g, buf, sizeof(buf)); |
407 | break; |
408 | case GRAND_SEEDUINT32: |
409 | i = va_arg(ap, uint32); |
410 | STORE32(buf, i); |
411 | prf_seed(g, buf, sizeof(buf)); |
412 | break; |
413 | case GRAND_SEEDBLOCK: { |
414 | const void *p = va_arg(ap, const void *); |
415 | size_t sz = va_arg(ap, size_t); |
416 | prf_seed(g, p, sz); |
417 | } break; |
418 | case GRAND_SEEDRAND: { |
419 | grand *rr = va_arg(ap, grand *); |
420 | octet buf[16]; |
421 | rr->ops->fill(rr, buf, sizeof(buf)); |
422 | prf_seed(g, buf, sizeof(buf)); |
423 | } break; |
424 | default: |
425 | GRAND_BADOP; |
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426 | break; |
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427 | } |
428 | |
429 | va_end(ap); |
430 | return (rc); |
431 | } |
432 | |
433 | static octet prf_grbyte(grand *r) |
434 | { |
435 | prf_grctx *g = (prf_grctx *)r; |
436 | octet o; |
437 | tlsprf_encrypt(&g->prf, 0, &o, 1); |
438 | return (o); |
439 | } |
440 | |
441 | static uint32 prf_grword(grand *r) |
442 | { |
443 | prf_grctx *g = (prf_grctx *)r; |
444 | octet b[4]; |
445 | tlsprf_encrypt(&g->prf, 0, &b, sizeof(b)); |
446 | return (LOAD32(b)); |
447 | } |
448 | |
449 | static void prf_grfill(grand *r, void *p, size_t sz) |
450 | { |
451 | prf_grctx *g = (prf_grctx *)r; |
452 | tlsprf_encrypt(&g->prf, 0, p, sz); |
453 | } |
454 | |
455 | static const grand_ops prf_grops = { |
55fae6a7 |
456 | "<tlsprf-dummy>", |
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457 | GRAND_CRYPTO, 0, |
458 | prf_grmisc, prf_grdestroy, |
459 | prf_grword, prf_grbyte, prf_grword, grand_range, prf_grfill |
460 | }; |
461 | |
462 | /* ---@tlsprf_rand@ --- * |
463 | * |
464 | * Arguments: @const gcmac *mcx, *mcy@ = MAC function to use |
465 | * @const void *k@ = pointer to the key material |
466 | * @size_t ksz@ = size of the key material |
467 | * @const void *sd@ = pointer to the seed material |
468 | * @size_t sdsz@ = size of the seed material |
469 | * |
470 | * Returns: Pointer to generic random number generator interface. |
471 | * |
472 | * Use: Creates a generic generator which does TLS data expansion. |
473 | */ |
474 | |
475 | grand *tlsprf_rand(const gcmac *mcx, const gcmac *mcy, |
476 | const void *k, size_t ksz, const void *sd, size_t sdsz) |
477 | { |
478 | prf_grctx *g = S_CREATE(prf_grctx); |
479 | dstr d = DSTR_INIT; |
480 | octet *q = xmalloc(sdsz); |
481 | memcpy(q, sd, sdsz); |
482 | dstr_putf(&d, "tlsprf(%s,%s)", mcx->name, mcy->name); |
483 | g->ops = prf_grops; |
484 | g->ops.name = xstrdup(d.buf); |
485 | g->r.ops = &g->ops; |
486 | dstr_destroy(&d); |
487 | tlsprf_init(&g->prf, mcx, mcy, k, ksz, q, sdsz); |
488 | return (&g->r); |
489 | } |
490 | |
491 | /*----- Test rig ----------------------------------------------------------*/ |
492 | |
493 | #ifdef TEST_RIG |
494 | |
495 | #include <stdio.h> |
496 | #include <string.h> |
497 | |
498 | #include <mLib/quis.h> |
499 | #include <mLib/testrig.h> |
500 | |
501 | #include "sha-hmac.h" |
502 | #include "md5-hmac.h" |
503 | |
504 | static int v_generate(dstr *v) |
505 | { |
506 | grand *g; |
507 | dstr d = DSTR_INIT; |
508 | int ok = 1; |
509 | |
510 | g = tlsprf_rand(&md5_hmac, &sha_hmac, |
511 | v[0].buf, v[0].len, v[1].buf, v[1].len); |
512 | dstr_ensure(&d, v[2].len); |
513 | d.len = v[2].len; |
514 | g->ops->fill(g, d.buf, d.len); |
515 | g->ops->destroy(g); |
516 | if (memcmp(v[2].buf, d.buf, d.len) != 0) { |
517 | ok = 0; |
518 | printf("\nfail tlsprf:" |
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519 | "\n\tkey = "); |
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520 | type_hex.dump(&v[0], stdout); |
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521 | printf("\n\tseed = "); type_hex.dump(&v[1], stdout); |
d83a82be |
522 | printf("\n\texpected = "); type_hex.dump(&v[2], stdout); |
523 | printf("\n\tcalculated = "); type_hex.dump(&d, stdout); |
524 | putchar('\n'); |
525 | } |
526 | return (ok); |
527 | } |
528 | |
529 | static test_chunk defs[] = { |
530 | { "tlsprf", v_generate, { &type_hex, &type_hex, &type_hex, 0 } }, |
531 | { 0, 0, { 0 } } |
532 | }; |
533 | |
534 | int main(int argc, char *argv[]) |
535 | { |
536 | test_run(argc, argv, defs, SRCDIR"/tests/tlsprf"); |
537 | return (0); |
538 | } |
539 | |
540 | #endif |
541 | |
542 | /*----- That's all, folks -------------------------------------------------*/ |