3 * The TLS pseudo-random function
5 * (c) 2001 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of Catacomb.
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.
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.
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,
28 /*----- Header files ------------------------------------------------------*/
30 #include <mLib/alloc.h>
31 #include <mLib/dstr.h>
40 /*----- The data expansion function ---------------------------------------*/
42 /* --- @tlsdx_init@ --- *
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
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.
56 void tlsdx_init(tlsdx_ctx *c, gmac *m, const void *sd, size_t sdsz)
59 c->hashsz = GM_CLASS(c->k)->hashsz;
60 c->sd = sd; c->sdsz = sdsz;
63 GH_HASH(c->i, sd, sdsz);
64 c->ai = GH_DONE(c->i, 0);
66 GH_HASH(c->o, c->ai, c->hashsz);
67 GH_HASH(c->o, sd, sdsz);
68 c->p = GH_DONE(c->o, 0);
72 /* --- @tlsdx_encrypt@ --- *
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
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.
88 void tlsdx_encrypt(tlsdx_ctx *c, const void *src, void *dest, size_t sz)
101 GH_HASH(h, c->ai, c->hashsz);
102 c->ai = GH_DONE(h, 0);
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);
110 c->sz = n = c->hashsz;
118 for (i = 0; i < n; i++) d[i] = s[i] ^ c->p[i];
129 /* --- @tlsdx_free@ --- *
131 * Arguments: @tlsdx_ctx *c@ = pointer to the context block
135 * Use: Frees a context for the TLS data expansion function
138 void tlsdx_free(tlsdx_ctx *c)
144 /* --- Generic random number generator --- */
146 typedef struct dx_grctx {
152 static void dx_grdestroy(grand *r)
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);
163 static void dx_seed(dx_grctx *g, const void *p, size_t sz)
166 xfree((octet *)g->dx.sd);
167 g->dx.sd = q = xmalloc(sz);
172 static int dx_grmisc(grand *r, unsigned op, ...)
174 dx_grctx *g = (dx_grctx *)r;
183 switch (va_arg(ap, unsigned)) {
186 case GRAND_SEEDUINT32:
187 case GRAND_SEEDBLOCK:
197 i = va_arg(ap, unsigned);
199 dx_seed(g, buf, sizeof(buf));
201 case GRAND_SEEDUINT32:
202 i = va_arg(ap, uint32);
204 dx_seed(g, buf, sizeof(buf));
206 case GRAND_SEEDBLOCK: {
207 const void *p = va_arg(ap, const void *);
208 size_t sz = va_arg(ap, size_t);
211 case GRAND_SEEDRAND: {
212 grand *rr = va_arg(ap, grand *);
214 rr->ops->fill(rr, buf, sizeof(buf));
215 dx_seed(g, buf, sizeof(buf));
226 static octet dx_grbyte(grand *r)
228 dx_grctx *g = (dx_grctx *)r;
230 tlsdx_encrypt(&g->dx, 0, &o, 1);
234 static uint32 dx_grword(grand *r)
236 dx_grctx *g = (dx_grctx *)r;
238 tlsdx_encrypt(&g->dx, 0, &b, sizeof(b));
242 static void dx_grfill(grand *r, void *p, size_t sz)
244 dx_grctx *g = (dx_grctx *)r;
245 tlsdx_encrypt(&g->dx, 0, p, sz);
248 static const grand_ops dx_grops = {
251 dx_grmisc, dx_grdestroy,
252 dx_grword, dx_grbyte, dx_grword, grand_defaultrange, dx_grfill
255 /* ---@tlsdx_rand@ --- *
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
263 * Returns: Pointer to generic random number generator interface.
265 * Use: Creates a generic generator which does TLS data expansion.
268 grand *tlsdx_rand(const gcmac *mc, const void *k, size_t ksz,
269 const void *sd, size_t sdsz)
271 dx_grctx *g = S_CREATE(dx_grctx);
273 gmac *m = GM_KEY(mc, k, ksz);
274 octet *q = xmalloc(sdsz);
276 dstr_putf(&d, "tlsdx(%s)", mc->name);
278 g->ops.name = xstrdup(d.buf);
281 tlsdx_init(&g->dx, m, q, sdsz);
285 /* --- The actual very paranoid PRF ---------------------------------------*/
287 /* --- @tlsprf_init@ --- *
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
298 * Use: Initializes a TLS PRF context.
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)
304 size_t n = (ksz + 1)/2;
306 tlsdx_init(&c->px, mcx->key(kk, n), sd, sdsz);
307 tlsdx_init(&c->py, mcy->key(kk + ksz - n, n), sd, sdsz);
310 /* --- @tlsprf_encrypt@ --- *
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
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.
326 void tlsprf_encrypt(tlsprf_ctx *c, const void *src, void *dest, size_t sz)
328 tlsdx_encrypt(&c->px, src, dest, sz);
329 tlsdx_encrypt(&c->py, dest, dest, sz);
332 /* --- @tlsprf_free@ --- *
334 * Arguments: @tlsprf_ctx *c@ = pointer to a context
338 * Use: Frees a TLS PRF context.
341 void tlsprf_free(tlsprf_ctx *c)
343 c->px.k->ops->destroy(c->px.k);
344 c->py.k->ops->destroy(c->py.k);
349 /* --- Generic random number generator --- */
351 typedef struct prf_grctx {
357 static void prf_grdestroy(grand *r)
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);
367 static void prf_seed(prf_grctx *g, const void *p, size_t sz)
371 xfree((octet *)g->prf.px.sz);
372 g->prf.px.sd = g->prf.py.sd = q = xmalloc(sz);
374 g->prf.px.sdsz = g->prf.py.sdsz = sz;
377 static int prf_grmisc(grand *r, unsigned op, ...)
379 prf_grctx *g = (prf_grctx *)r;
388 switch (va_arg(ap, unsigned)) {
391 case GRAND_SEEDUINT32:
392 case GRAND_SEEDBLOCK:
402 i = va_arg(ap, unsigned);
404 prf_seed(g, buf, sizeof(buf));
406 case GRAND_SEEDUINT32:
407 i = va_arg(ap, uint32);
409 prf_seed(g, buf, sizeof(buf));
411 case GRAND_SEEDBLOCK: {
412 const void *p = va_arg(ap, const void *);
413 size_t sz = va_arg(ap, size_t);
416 case GRAND_SEEDRAND: {
417 grand *rr = va_arg(ap, grand *);
419 rr->ops->fill(rr, buf, sizeof(buf));
420 prf_seed(g, buf, sizeof(buf));
431 static octet prf_grbyte(grand *r)
433 prf_grctx *g = (prf_grctx *)r;
435 tlsprf_encrypt(&g->prf, 0, &o, 1);
439 static uint32 prf_grword(grand *r)
441 prf_grctx *g = (prf_grctx *)r;
443 tlsprf_encrypt(&g->prf, 0, &b, sizeof(b));
447 static void prf_grfill(grand *r, void *p, size_t sz)
449 prf_grctx *g = (prf_grctx *)r;
450 tlsprf_encrypt(&g->prf, 0, p, sz);
453 static const grand_ops prf_grops = {
456 prf_grmisc, prf_grdestroy,
457 prf_grword, prf_grbyte, prf_grword, grand_defaultrange, prf_grfill
460 /* ---@tlsprf_rand@ --- *
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
468 * Returns: Pointer to generic random number generator interface.
470 * Use: Creates a generic generator which does TLS data expansion.
473 grand *tlsprf_rand(const gcmac *mcx, const gcmac *mcy,
474 const void *k, size_t ksz, const void *sd, size_t sdsz)
476 prf_grctx *g = S_CREATE(prf_grctx);
478 octet *q = xmalloc(sdsz);
480 dstr_putf(&d, "tlsprf(%s,%s)", mcx->name, mcy->name);
482 g->ops.name = xstrdup(d.buf);
485 tlsprf_init(&g->prf, mcx, mcy, k, ksz, q, sdsz);
489 /*----- Test rig ----------------------------------------------------------*/
496 #include <mLib/quis.h>
497 #include <mLib/testrig.h>
499 #include "sha-hmac.h"
500 #include "md5-hmac.h"
502 static int v_generate(dstr *v)
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);
512 g->ops->fill(g, d.buf, d.len);
514 if (memcmp(v[2].buf, d.buf, d.len) != 0) {
516 printf("\nfail tlsprf:"
518 type_hex.dump(&v[0], stdout);
519 printf("\n\tseed = "); type_hex.dump(&v[1], stdout);
520 printf("\n\texpected = "); type_hex.dump(&v[2], stdout);
521 printf("\n\tcalculated = "); type_hex.dump(&d, stdout);
527 static test_chunk defs[] = {
528 { "tlsprf", v_generate, { &type_hex, &type_hex, &type_hex, 0 } },
532 int main(int argc, char *argv[])
534 test_run(argc, argv, defs, SRCDIR"/t/tlsprf");
540 /*----- That's all, folks -------------------------------------------------*/