51a0f805 |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: sslprf.c,v 1.1 2001/04/06 22:05:10 mdw Exp $ |
4 | * |
5 | * The SSL 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: sslprf.c,v $ |
33 | * Revision 1.1 2001/04/06 22:05:10 mdw |
34 | * Add support for SSL pseudo-random function. |
35 | * |
36 | */ |
37 | |
38 | /*----- Header files ------------------------------------------------------*/ |
39 | |
40 | #include <mLib/alloc.h> |
41 | #include <mLib/dstr.h> |
42 | #include <mLib/sub.h> |
43 | |
44 | #include "arena.h" |
45 | #include "ghash.h" |
46 | #include "grand.h" |
47 | #include "paranoia.h" |
48 | #include "sslprf.h" |
49 | |
50 | /*----- Main code ---------------------------------------------------------*/ |
51 | |
52 | /* --- @step@ --- * |
53 | * |
54 | * Arguments: @sslprf_ctx *c@ = pointer to context structure |
55 | * |
56 | * Returns: --- |
57 | * |
58 | * Use: Steps the generator. |
59 | */ |
60 | |
61 | static void step(sslprf_ctx *c) |
62 | { |
63 | octet buf[64]; |
64 | size_t n, sz; |
65 | octet x; |
66 | ghash *h, *hh; |
67 | octet *p; |
68 | |
69 | h = c->ci->init(); |
70 | x = 'A' + c->i - 1; |
71 | for (sz = c->i++; sz > 0; sz -= n) { |
72 | n = sz; |
73 | if (n > sizeof(buf)) |
74 | n = sizeof(buf); |
75 | memset(buf, x, n); |
76 | h->ops->hash(h, buf, n); |
77 | } |
78 | h->ops->hash(h, c->k, c->ksz); |
79 | h->ops->hash(h, c->sd, c->sdsz); |
80 | p = h->ops->done(h, 0); |
81 | |
82 | hh = c->co->init(); |
83 | hh->ops->hash(hh, c->k, c->ksz); |
84 | hh->ops->hash(hh, p, c->ihashsz); |
85 | c->p = hh->ops->done(hh, 0); |
86 | h->ops->destroy(h); |
87 | |
88 | c->h = hh; |
89 | c->sz = c->ohashsz; |
90 | } |
91 | |
92 | /* --- @sslprf_init@ --- * |
93 | * |
94 | * Arguments: @sslprf_ctx *c@ = pointer to a context structure |
95 | * @const gchash *hco, *hci@ = outer and inner hash functions |
96 | * @const void *k@ = pointer to secret buffer |
97 | * @size_t ksz@ = size of the secret |
98 | * @const void *sd@ = pointer to seed buffer |
99 | * @size_t sdsz@ = size of the seed |
100 | * |
101 | * Returns: --- |
102 | * |
103 | * Use: Initializes an SSL generator context. |
104 | */ |
105 | |
106 | void sslprf_init(sslprf_ctx *c, const gchash *hco, const gchash *hci, |
107 | const void *k, size_t ksz, |
108 | const void *sd, size_t sdsz) |
109 | { |
110 | c->co = hco; c->ci = hci; |
111 | c->ohashsz = hco->hashsz; c->ihashsz = hci->hashsz; |
112 | c->k = k; c->ksz = ksz; c->sd = sd; c->sdsz = sdsz; |
113 | c->i = 1; |
114 | step(c); |
115 | } |
116 | |
117 | /* --- @sslprf_encrypt@ --- * |
118 | * |
119 | * Arguments: @sslprf_ctx *c@ = pointer to a context structure |
120 | * @const void *src@ = pointer to source buffer |
121 | * @void *dest@ = pointer to destination buffer |
122 | * @size_t sz@ = size of the buffers |
123 | * |
124 | * Returns: --- |
125 | * |
126 | * Use: Encrypts data using the SSL pseudo-random function. If the |
127 | * destination pointer is null, the generator is spun and no |
128 | * output is produced; if the source pointer is null, raw output |
129 | * from the generator is written; otherwise, the source data is |
130 | * XORed with the generator output. |
131 | */ |
132 | |
133 | void sslprf_encrypt(sslprf_ctx *c, const void *src, void *dest, size_t sz) |
134 | { |
135 | const octet *s = src; |
136 | octet *d = dest; |
137 | size_t i, n; |
138 | |
139 | while (sz) { |
140 | if (!c->sz) { |
141 | c->h->ops->destroy(c->h); |
142 | step(c); |
143 | } |
144 | n = c->sz; |
145 | if (n > sz) |
146 | n = sz; |
147 | if (d) { |
148 | if (!s) |
149 | memcpy(d, c->p, n); |
150 | else { |
151 | for (i = 0; i < n; i++) d[i] = s[i] ^ c->p[i]; |
152 | s += n; |
153 | } |
154 | d += n; |
155 | } |
156 | c->p += n; |
157 | c->sz -= n; |
158 | sz -= n; |
159 | } |
160 | } |
161 | |
162 | /* --- @sslprf_free@ --- * |
163 | * |
164 | * Arguments: @sslprf_ctx@ = pointer to a context |
165 | * |
166 | * Returns: --- |
167 | * |
168 | * Use: Frees resources held in an SSL generator context. |
169 | */ |
170 | |
171 | void sslprf_free(sslprf_ctx *c) |
172 | { |
173 | c->h->ops->destroy(c->h); |
174 | } |
175 | |
176 | /* --- Generic random number generator --- */ |
177 | |
178 | typedef struct grctx { |
179 | grand r; |
180 | grand_ops ops; |
181 | sslprf_ctx prf; |
182 | } grctx; |
183 | |
184 | static void grdestroy(grand *r) |
185 | { |
186 | grctx *g = (grctx *)r; |
187 | xfree((char *)g->ops.name); |
188 | xfree((octet *)g->prf.sd); |
189 | sslprf_free(&g->prf); |
190 | BURN(*g); |
191 | S_DESTROY(g); |
192 | } |
193 | |
194 | static void seed(grctx *g, const void *p, size_t sz) |
195 | { |
196 | octet *q; |
197 | xfree((octet *)g->prf.sd); |
198 | g->prf.sd = q = xmalloc(sz); |
199 | memcpy(q, p, sz); |
200 | g->prf.sdsz = sz; |
201 | } |
202 | |
203 | static int grmisc(grand *r, unsigned op, ...) |
204 | { |
205 | grctx *g = (grctx *)r; |
206 | va_list ap; |
207 | int rc = 0; |
208 | uint32 i; |
209 | octet buf[4]; |
210 | va_start(ap, op); |
211 | |
212 | switch (op) { |
213 | case GRAND_CHECK: |
214 | switch (va_arg(ap, unsigned)) { |
215 | case GRAND_CHECK: |
216 | case GRAND_SEEDINT: |
217 | case GRAND_SEEDUINT32: |
218 | case GRAND_SEEDBLOCK: |
219 | case GRAND_SEEDRAND: |
220 | rc = 1; |
221 | break; |
222 | default: |
223 | rc = 0; |
224 | break; |
225 | } |
226 | break; |
227 | case GRAND_SEEDINT: |
228 | i = va_arg(ap, unsigned); |
229 | STORE32(buf, i); |
230 | seed(g, buf, sizeof(buf)); |
231 | break; |
232 | case GRAND_SEEDUINT32: |
233 | i = va_arg(ap, uint32); |
234 | STORE32(buf, i); |
235 | seed(g, buf, sizeof(buf)); |
236 | break; |
237 | case GRAND_SEEDBLOCK: { |
238 | const void *p = va_arg(ap, const void *); |
239 | size_t sz = va_arg(ap, size_t); |
240 | seed(g, p, sz); |
241 | } break; |
242 | case GRAND_SEEDRAND: { |
243 | grand *rr = va_arg(ap, grand *); |
244 | octet buf[16]; |
245 | rr->ops->fill(rr, buf, sizeof(buf)); |
246 | seed(g, buf, sizeof(buf)); |
247 | } break; |
248 | default: |
249 | GRAND_BADOP; |
250 | break; |
251 | } |
252 | |
253 | va_end(ap); |
254 | return (rc); |
255 | } |
256 | |
257 | static octet grbyte(grand *r) |
258 | { |
259 | grctx *g = (grctx *)r; |
260 | octet o; |
261 | sslprf_encrypt(&g->prf, 0, &o, 1); |
262 | return (o); |
263 | } |
264 | |
265 | static uint32 grword(grand *r) |
266 | { |
267 | grctx *g = (grctx *)r; |
268 | octet b[4]; |
269 | sslprf_encrypt(&g->prf, 0, &b, sizeof(b)); |
270 | return (LOAD32(b)); |
271 | } |
272 | |
273 | static void grfill(grand *r, void *p, size_t sz) |
274 | { |
275 | grctx *g = (grctx *)r; |
276 | sslprf_encrypt(&g->prf, 0, p, sz); |
277 | } |
278 | |
279 | static const grand_ops grops = { |
280 | "<sslprf-dummy>", |
281 | GRAND_CRYPTO, 0, |
282 | grmisc, grdestroy, |
283 | grword, grbyte, grword, grand_range, grfill |
284 | }; |
285 | |
286 | /* ---@sslprf_rand@ --- * |
287 | * |
288 | * Arguments: @const gchash *hco, const gchash *hci@ = hash functions |
289 | * @const void *k@ = pointer to the key material |
290 | * @size_t ksz@ = size of the key material |
291 | * @const void *sd@ = pointer to the seed material |
292 | * @size_t sdsz@ = size of the seed material |
293 | * |
294 | * Returns: Pointer to generic random number generator interface. |
295 | * |
296 | * Use: Creates a generic generator which does TLS data expansion. |
297 | */ |
298 | |
299 | grand *sslprf_rand(const gchash *hco, const gchash *hci, |
300 | const void *k, size_t ksz, |
301 | const void *sd, size_t sdsz) |
302 | { |
303 | grctx *g = S_CREATE(grctx); |
304 | dstr d = DSTR_INIT; |
305 | octet *q = xmalloc(sdsz); |
306 | memcpy(q, sd, sdsz); |
307 | dstr_putf(&d, "sslprf(%s,%s)", hco->name, hci->name); |
308 | g->ops = grops; |
309 | g->ops.name = xstrdup(d.buf); |
310 | g->r.ops = &g->ops; |
311 | dstr_destroy(&d); |
312 | sslprf_init(&g->prf, hco, hci, k, ksz, q, sdsz); |
313 | return (&g->r); |
314 | } |
315 | |
316 | /*----- Test rig ----------------------------------------------------------*/ |
317 | |
318 | #ifdef TEST_RIG |
319 | |
320 | #include <stdio.h> |
321 | #include <string.h> |
322 | |
323 | #include <mLib/quis.h> |
324 | #include <mLib/testrig.h> |
325 | |
326 | #include "sha.h" |
327 | #include "md5.h" |
328 | |
329 | static int v_generate(dstr *v) |
330 | { |
331 | grand *g; |
332 | dstr d = DSTR_INIT; |
333 | int ok = 1; |
334 | |
335 | g = sslprf_rand(&md5, &sha, v[0].buf, v[0].len, v[1].buf, v[1].len); |
336 | dstr_ensure(&d, v[2].len); |
337 | d.len = v[2].len; |
338 | g->ops->fill(g, d.buf, d.len); |
339 | g->ops->destroy(g); |
340 | if (memcmp(v[2].buf, d.buf, d.len) != 0) { |
341 | ok = 0; |
342 | printf("\nfail sslprf:" |
343 | "\n\tkey = "); |
344 | type_hex.dump(&v[0], stdout); |
345 | printf("\n\tseed = "); type_hex.dump(&v[1], stdout); |
346 | printf("\n\texpected = "); type_hex.dump(&v[2], stdout); |
347 | printf("\n\tcalculated = "); type_hex.dump(&d, stdout); |
348 | putchar('\n'); |
349 | } |
350 | return (ok); |
351 | } |
352 | |
353 | static test_chunk defs[] = { |
354 | { "sslprf", v_generate, { &type_hex, &type_hex, &type_hex, 0 } }, |
355 | { 0, 0, { 0 } } |
356 | }; |
357 | |
358 | int main(int argc, char *argv[]) |
359 | { |
360 | test_run(argc, argv, defs, SRCDIR"/tests/sslprf"); |
361 | return (0); |
362 | } |
363 | |
364 | #endif |
365 | |
366 | /*----- That's all, folks -------------------------------------------------*/ |