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1 | /* -*-c-*- |
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2 | * |
3 | * The TLS pseudo-random function |
4 | * |
5 | * (c) 2001 Straylight/Edgeware |
6 | */ |
7 | |
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8 | /*----- Licensing notice --------------------------------------------------* |
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9 | * |
10 | * This file is part of Catacomb. |
11 | * |
12 | * Catacomb is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU Library General Public License as |
14 | * published by the Free Software Foundation; either version 2 of the |
15 | * License, or (at your option) any later version. |
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16 | * |
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17 | * Catacomb 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 Library General Public License for more details. |
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21 | * |
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22 | * You should have received a copy of the GNU Library General Public |
23 | * License along with Catacomb; if not, write to the Free |
24 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
25 | * MA 02111-1307, USA. |
26 | */ |
27 | |
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28 | /*----- Header files ------------------------------------------------------*/ |
29 | |
30 | #include <mLib/alloc.h> |
31 | #include <mLib/dstr.h> |
32 | #include <mLib/sub.h> |
33 | |
34 | #include "arena.h" |
35 | #include "gmac.h" |
36 | #include "grand.h" |
37 | #include "paranoia.h" |
38 | #include "tlsprf.h" |
39 | |
40 | /*----- The data expansion function ---------------------------------------*/ |
41 | |
42 | /* --- @tlsdx_init@ --- * |
43 | * |
44 | * Arguments: @tlsdx_ctx *c@ = pointer to a context |
45 | * @gmac *m@ = pointer to a generic MAC instance |
46 | * @const void *sd@ = pointer to the seed block |
47 | * @size_t sdsz@ = size of the seed block |
48 | * |
49 | * Returns: --- |
50 | * |
51 | * Use: Initializes a context for the TLS data expansion function. |
52 | * This doesn't take ownership of the MAC instance or the seed |
53 | * memory, nor does it allocate copies. |
54 | */ |
55 | |
56 | void tlsdx_init(tlsdx_ctx *c, gmac *m, const void *sd, size_t sdsz) |
57 | { |
58 | c->k = m; |
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59 | c->hashsz = GM_CLASS(c->k)->hashsz; |
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60 | c->sd = sd; c->sdsz = sdsz; |
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61 | |
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62 | c->i = GM_INIT(c->k); |
63 | GH_HASH(c->i, sd, sdsz); |
64 | c->ai = GH_DONE(c->i, 0); |
65 | c->o = GM_INIT(c->k); |
66 | GH_HASH(c->o, c->ai, c->hashsz); |
67 | GH_HASH(c->o, sd, sdsz); |
68 | c->p = GH_DONE(c->o, 0); |
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69 | c->sz = c->hashsz; |
70 | } |
71 | |
72 | /* --- @tlsdx_encrypt@ --- * |
73 | * |
74 | * Arguments: @tlsdx_ctx *c@ = pointer to a context |
75 | * @const void *src@ = pointer to source data |
76 | * @void *dest@ = pointer to destination buffer |
77 | * @size_t sz@ = size of buffer |
78 | * |
79 | * Returns: --- |
80 | * |
81 | * Use: Encrypts data using the TLS data expansion function. If the |
82 | * destination pointer is null, the generator is spun and no |
83 | * output is produced; if the source pointer is null, raw output |
84 | * from the generator is written; otherwise, the source data is |
85 | * XORed with the generator output. |
86 | */ |
87 | |
88 | void tlsdx_encrypt(tlsdx_ctx *c, const void *src, void *dest, size_t sz) |
89 | { |
90 | const octet *s = src; |
91 | octet *d = dest; |
92 | ghash *h; |
93 | size_t i; |
94 | size_t n; |
95 | |
96 | while (sz) { |
97 | if (c->sz) |
98 | n = c->sz; |
99 | else { |
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100 | h = GM_INIT(c->k); |
101 | GH_HASH(h, c->ai, c->hashsz); |
102 | c->ai = GH_DONE(h, 0); |
103 | GH_DESTROY(c->i); |
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104 | c->i = h; |
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105 | GH_DESTROY(c->o); |
106 | h = c->o = GM_INIT(c->k); |
107 | GH_HASH(h, c->ai, c->hashsz); |
108 | GH_HASH(h, c->sd, c->sdsz); |
109 | c->p = GH_DONE(h, 0); |
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110 | c->sz = n = c->hashsz; |
111 | } |
112 | if (n > sz) |
113 | n = sz; |
114 | if (d) { |
115 | if (!s) |
116 | memcpy(d, c->p, n); |
117 | else { |
118 | for (i = 0; i < n; i++) d[i] = s[i] ^ c->p[i]; |
119 | s += n; |
120 | } |
121 | d += n; |
122 | } |
123 | c->p += n; |
124 | c->sz -= n; |
125 | sz -= n; |
126 | } |
127 | } |
128 | |
129 | /* --- @tlsdx_free@ --- * |
130 | * |
131 | * Arguments: @tlsdx_ctx *c@ = pointer to the context block |
132 | * |
133 | * Returns: --- |
134 | * |
135 | * Use: Frees a context for the TLS data expansion function |
136 | */ |
137 | |
138 | void tlsdx_free(tlsdx_ctx *c) |
139 | { |
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140 | GH_DESTROY(c->i); |
141 | GH_DESTROY(c->o); |
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142 | } |
143 | |
144 | /* --- Generic random number generator --- */ |
145 | |
146 | typedef struct dx_grctx { |
147 | grand r; |
148 | grand_ops ops; |
149 | tlsdx_ctx dx; |
150 | } dx_grctx; |
151 | |
152 | static void dx_grdestroy(grand *r) |
153 | { |
154 | dx_grctx *g = (dx_grctx *)r; |
155 | xfree((char *)g->ops.name); |
156 | xfree((octet *)g->dx.sd); |
157 | g->dx.k->ops->destroy(g->dx.k); |
158 | tlsdx_free(&g->dx); |
159 | BURN(*g); |
160 | S_DESTROY(g); |
161 | } |
162 | |
163 | static void dx_seed(dx_grctx *g, const void *p, size_t sz) |
164 | { |
165 | octet *q; |
166 | xfree((octet *)g->dx.sd); |
167 | g->dx.sd = q = xmalloc(sz); |
168 | memcpy(q, p, sz); |
169 | g->dx.sdsz = sz; |
170 | } |
171 | |
172 | static int dx_grmisc(grand *r, unsigned op, ...) |
173 | { |
174 | dx_grctx *g = (dx_grctx *)r; |
175 | va_list ap; |
176 | int rc = 0; |
177 | uint32 i; |
178 | octet buf[4]; |
179 | va_start(ap, op); |
180 | |
181 | switch (op) { |
182 | case GRAND_CHECK: |
183 | switch (va_arg(ap, unsigned)) { |
184 | case GRAND_CHECK: |
185 | case GRAND_SEEDINT: |
186 | case GRAND_SEEDUINT32: |
187 | case GRAND_SEEDBLOCK: |
188 | case GRAND_SEEDRAND: |
189 | rc = 1; |
190 | break; |
191 | default: |
192 | rc = 0; |
193 | break; |
194 | } |
195 | break; |
196 | case GRAND_SEEDINT: |
197 | i = va_arg(ap, unsigned); |
198 | STORE32(buf, i); |
199 | dx_seed(g, buf, sizeof(buf)); |
200 | break; |
201 | case GRAND_SEEDUINT32: |
202 | i = va_arg(ap, uint32); |
203 | STORE32(buf, i); |
204 | dx_seed(g, buf, sizeof(buf)); |
205 | break; |
206 | case GRAND_SEEDBLOCK: { |
207 | const void *p = va_arg(ap, const void *); |
208 | size_t sz = va_arg(ap, size_t); |
209 | dx_seed(g, p, sz); |
210 | } break; |
211 | case GRAND_SEEDRAND: { |
212 | grand *rr = va_arg(ap, grand *); |
213 | octet buf[16]; |
214 | rr->ops->fill(rr, buf, sizeof(buf)); |
215 | dx_seed(g, buf, sizeof(buf)); |
216 | } break; |
217 | default: |
218 | GRAND_BADOP; |
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219 | break; |
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220 | } |
221 | |
222 | va_end(ap); |
223 | return (rc); |
224 | } |
225 | |
226 | static octet dx_grbyte(grand *r) |
227 | { |
228 | dx_grctx *g = (dx_grctx *)r; |
229 | octet o; |
230 | tlsdx_encrypt(&g->dx, 0, &o, 1); |
231 | return (o); |
232 | } |
233 | |
234 | static uint32 dx_grword(grand *r) |
235 | { |
236 | dx_grctx *g = (dx_grctx *)r; |
237 | octet b[4]; |
238 | tlsdx_encrypt(&g->dx, 0, &b, sizeof(b)); |
239 | return (LOAD32(b)); |
240 | } |
241 | |
242 | static void dx_grfill(grand *r, void *p, size_t sz) |
243 | { |
244 | dx_grctx *g = (dx_grctx *)r; |
245 | tlsdx_encrypt(&g->dx, 0, p, sz); |
246 | } |
247 | |
248 | static const grand_ops dx_grops = { |
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249 | "<tlsdx-dummy>", |
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250 | GRAND_CRYPTO, 0, |
251 | dx_grmisc, dx_grdestroy, |
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252 | dx_grword, dx_grbyte, dx_grword, grand_defaultrange, dx_grfill |
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253 | }; |
254 | |
255 | /* ---@tlsdx_rand@ --- * |
256 | * |
257 | * Arguments: @const gcmac *mc@ = MAC function to use |
258 | * @const void *k@ = pointer to the key material |
259 | * @size_t ksz@ = size of the key material |
260 | * @const void *sd@ = pointer to the seed material |
261 | * @size_t sdsz@ = size of the seed material |
262 | * |
263 | * Returns: Pointer to generic random number generator interface. |
264 | * |
265 | * Use: Creates a generic generator which does TLS data expansion. |
266 | */ |
267 | |
268 | grand *tlsdx_rand(const gcmac *mc, const void *k, size_t ksz, |
269 | const void *sd, size_t sdsz) |
270 | { |
271 | dx_grctx *g = S_CREATE(dx_grctx); |
272 | dstr d = DSTR_INIT; |
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273 | gmac *m = GM_KEY(mc, k, ksz); |
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274 | octet *q = xmalloc(sdsz); |
275 | memcpy(q, sd, sdsz); |
276 | dstr_putf(&d, "tlsdx(%s)", mc->name); |
277 | g->ops = dx_grops; |
278 | g->ops.name = xstrdup(d.buf); |
279 | g->r.ops = &g->ops; |
280 | dstr_destroy(&d); |
281 | tlsdx_init(&g->dx, m, q, sdsz); |
282 | return (&g->r); |
283 | } |
284 | |
285 | /* --- The actual very paranoid PRF ---------------------------------------*/ |
286 | |
287 | /* --- @tlsprf_init@ --- * |
288 | * |
289 | * Arguments: @tlsprf_ctx *c@ = pointer to context block |
290 | * @const gcmac *mcx, *mcy@ = left and right MAC functions |
291 | * @const void *k@ = pointer to the key material |
292 | * @size_t ksz@ = size of the key material |
293 | * @const void *sd@ = pointer to the seed material |
294 | * @size_t sdsz@ = size of the seed material |
295 | * |
296 | * Returns: --- |
297 | * |
298 | * Use: Initializes a TLS PRF context. |
299 | */ |
300 | |
301 | void tlsprf_init(tlsprf_ctx *c, const gcmac *mcx, const gcmac *mcy, |
302 | const void *k, size_t ksz, const void *sd, size_t sdsz) |
303 | { |
304 | size_t n = (ksz + 1)/2; |
305 | const octet *kk = k; |
306 | tlsdx_init(&c->px, mcx->key(kk, n), sd, sdsz); |
307 | tlsdx_init(&c->py, mcy->key(kk + ksz - n, n), sd, sdsz); |
308 | } |
309 | |
310 | /* --- @tlsprf_encrypt@ --- * |
311 | * |
312 | * Arguments: @tlsprf_ctx *c@ = pointer to a context |
313 | * @const void *src@ = pointer to source data |
314 | * @void *dest@ = pointer to destination buffer |
315 | * @size_t sz@ = size of buffer |
316 | * |
317 | * Returns: --- |
318 | * |
319 | * Use: Encrypts data using the TLS pseudo-random function. If the |
320 | * destination pointer is null, the generator is spun and no |
321 | * output is produced; if the source pointer is null, raw output |
322 | * from the generator is written; otherwise, the source data is |
323 | * XORed with the generator output. |
324 | */ |
325 | |
326 | void tlsprf_encrypt(tlsprf_ctx *c, const void *src, void *dest, size_t sz) |
327 | { |
328 | tlsdx_encrypt(&c->px, src, dest, sz); |
329 | tlsdx_encrypt(&c->py, dest, dest, sz); |
330 | } |
331 | |
332 | /* --- @tlsprf_free@ --- * |
333 | * |
334 | * Arguments: @tlsprf_ctx *c@ = pointer to a context |
335 | * |
336 | * Returns: --- |
337 | * |
338 | * Use: Frees a TLS PRF context. |
339 | */ |
340 | |
341 | void tlsprf_free(tlsprf_ctx *c) |
342 | { |
343 | c->px.k->ops->destroy(c->px.k); |
344 | c->py.k->ops->destroy(c->py.k); |
345 | tlsdx_free(&c->px); |
346 | tlsdx_free(&c->py); |
347 | } |
348 | |
349 | /* --- Generic random number generator --- */ |
350 | |
351 | typedef struct prf_grctx { |
352 | grand r; |
353 | grand_ops ops; |
354 | tlsprf_ctx prf; |
355 | } prf_grctx; |
356 | |
357 | static void prf_grdestroy(grand *r) |
358 | { |
359 | prf_grctx *g = (prf_grctx *)r; |
360 | xfree((char *)g->ops.name); |
361 | xfree((octet *)g->prf.px.sd); |
362 | tlsprf_free(&g->prf); |
363 | BURN(*g); |
364 | S_DESTROY(g); |
365 | } |
366 | |
367 | static void prf_seed(prf_grctx *g, const void *p, size_t sz) |
368 | { |
369 | octet *q; |
370 | |
371 | xfree((octet *)g->prf.px.sz); |
372 | g->prf.px.sd = g->prf.py.sd = q = xmalloc(sz); |
373 | memcpy(q, p, sz); |
374 | g->prf.px.sdsz = g->prf.py.sdsz = sz; |
375 | } |
376 | |
377 | static int prf_grmisc(grand *r, unsigned op, ...) |
378 | { |
379 | prf_grctx *g = (prf_grctx *)r; |
380 | va_list ap; |
381 | int rc = 0; |
382 | uint32 i; |
383 | octet buf[4]; |
384 | va_start(ap, op); |
385 | |
386 | switch (op) { |
387 | case GRAND_CHECK: |
388 | switch (va_arg(ap, unsigned)) { |
389 | case GRAND_CHECK: |
390 | case GRAND_SEEDINT: |
391 | case GRAND_SEEDUINT32: |
392 | case GRAND_SEEDBLOCK: |
393 | case GRAND_SEEDRAND: |
394 | rc = 1; |
395 | break; |
396 | default: |
397 | rc = 0; |
398 | break; |
399 | } |
400 | break; |
401 | case GRAND_SEEDINT: |
402 | i = va_arg(ap, unsigned); |
403 | STORE32(buf, i); |
404 | prf_seed(g, buf, sizeof(buf)); |
405 | break; |
406 | case GRAND_SEEDUINT32: |
407 | i = va_arg(ap, uint32); |
408 | STORE32(buf, i); |
409 | prf_seed(g, buf, sizeof(buf)); |
410 | break; |
411 | case GRAND_SEEDBLOCK: { |
412 | const void *p = va_arg(ap, const void *); |
413 | size_t sz = va_arg(ap, size_t); |
414 | prf_seed(g, p, sz); |
415 | } break; |
416 | case GRAND_SEEDRAND: { |
417 | grand *rr = va_arg(ap, grand *); |
418 | octet buf[16]; |
419 | rr->ops->fill(rr, buf, sizeof(buf)); |
420 | prf_seed(g, buf, sizeof(buf)); |
421 | } break; |
422 | default: |
423 | GRAND_BADOP; |
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424 | break; |
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425 | } |
426 | |
427 | va_end(ap); |
428 | return (rc); |
429 | } |
430 | |
431 | static octet prf_grbyte(grand *r) |
432 | { |
433 | prf_grctx *g = (prf_grctx *)r; |
434 | octet o; |
435 | tlsprf_encrypt(&g->prf, 0, &o, 1); |
436 | return (o); |
437 | } |
438 | |
439 | static uint32 prf_grword(grand *r) |
440 | { |
441 | prf_grctx *g = (prf_grctx *)r; |
442 | octet b[4]; |
443 | tlsprf_encrypt(&g->prf, 0, &b, sizeof(b)); |
444 | return (LOAD32(b)); |
445 | } |
446 | |
447 | static void prf_grfill(grand *r, void *p, size_t sz) |
448 | { |
449 | prf_grctx *g = (prf_grctx *)r; |
450 | tlsprf_encrypt(&g->prf, 0, p, sz); |
451 | } |
452 | |
453 | static const grand_ops prf_grops = { |
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454 | "<tlsprf-dummy>", |
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455 | GRAND_CRYPTO, 0, |
456 | prf_grmisc, prf_grdestroy, |
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457 | prf_grword, prf_grbyte, prf_grword, grand_defaultrange, prf_grfill |
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458 | }; |
459 | |
460 | /* ---@tlsprf_rand@ --- * |
461 | * |
462 | * Arguments: @const gcmac *mcx, *mcy@ = MAC function to use |
463 | * @const void *k@ = pointer to the key material |
464 | * @size_t ksz@ = size of the key material |
465 | * @const void *sd@ = pointer to the seed material |
466 | * @size_t sdsz@ = size of the seed material |
467 | * |
468 | * Returns: Pointer to generic random number generator interface. |
469 | * |
470 | * Use: Creates a generic generator which does TLS data expansion. |
471 | */ |
472 | |
473 | grand *tlsprf_rand(const gcmac *mcx, const gcmac *mcy, |
474 | const void *k, size_t ksz, const void *sd, size_t sdsz) |
475 | { |
476 | prf_grctx *g = S_CREATE(prf_grctx); |
477 | dstr d = DSTR_INIT; |
478 | octet *q = xmalloc(sdsz); |
479 | memcpy(q, sd, sdsz); |
480 | dstr_putf(&d, "tlsprf(%s,%s)", mcx->name, mcy->name); |
481 | g->ops = prf_grops; |
482 | g->ops.name = xstrdup(d.buf); |
483 | g->r.ops = &g->ops; |
484 | dstr_destroy(&d); |
485 | tlsprf_init(&g->prf, mcx, mcy, k, ksz, q, sdsz); |
486 | return (&g->r); |
487 | } |
488 | |
489 | /*----- Test rig ----------------------------------------------------------*/ |
490 | |
491 | #ifdef TEST_RIG |
492 | |
493 | #include <stdio.h> |
494 | #include <string.h> |
495 | |
496 | #include <mLib/quis.h> |
497 | #include <mLib/testrig.h> |
498 | |
499 | #include "sha-hmac.h" |
500 | #include "md5-hmac.h" |
501 | |
502 | static int v_generate(dstr *v) |
503 | { |
504 | grand *g; |
505 | dstr d = DSTR_INIT; |
506 | int ok = 1; |
507 | |
508 | g = tlsprf_rand(&md5_hmac, &sha_hmac, |
509 | v[0].buf, v[0].len, v[1].buf, v[1].len); |
510 | dstr_ensure(&d, v[2].len); |
511 | d.len = v[2].len; |
512 | g->ops->fill(g, d.buf, d.len); |
513 | g->ops->destroy(g); |
514 | if (memcmp(v[2].buf, d.buf, d.len) != 0) { |
515 | ok = 0; |
516 | printf("\nfail tlsprf:" |
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517 | "\n\tkey = "); |
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518 | type_hex.dump(&v[0], stdout); |
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519 | printf("\n\tseed = "); type_hex.dump(&v[1], stdout); |
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520 | printf("\n\texpected = "); type_hex.dump(&v[2], stdout); |
521 | printf("\n\tcalculated = "); type_hex.dump(&d, stdout); |
522 | putchar('\n'); |
523 | } |
524 | return (ok); |
525 | } |
526 | |
527 | static test_chunk defs[] = { |
528 | { "tlsprf", v_generate, { &type_hex, &type_hex, &type_hex, 0 } }, |
529 | { 0, 0, { 0 } } |
530 | }; |
531 | |
532 | int main(int argc, char *argv[]) |
533 | { |
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534 | test_run(argc, argv, defs, SRCDIR"/t/tlsprf"); |
d83a82be |
535 | return (0); |
536 | } |
537 | |
538 | #endif |
539 | |
540 | /*----- That's all, folks -------------------------------------------------*/ |