| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * The SSL pseudo-random function |
| 4 | * |
| 5 | * (c) 2001 Straylight/Edgeware |
| 6 | */ |
| 7 | |
| 8 | /*----- Licensing notice --------------------------------------------------* |
| 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. |
| 16 | * |
| 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. |
| 21 | * |
| 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 | |
| 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 "ghash.h" |
| 36 | #include "grand.h" |
| 37 | #include "paranoia.h" |
| 38 | #include "sslprf.h" |
| 39 | |
| 40 | /*----- Main code ---------------------------------------------------------*/ |
| 41 | |
| 42 | /* --- @step@ --- * |
| 43 | * |
| 44 | * Arguments: @sslprf_ctx *c@ = pointer to context structure |
| 45 | * |
| 46 | * Returns: --- |
| 47 | * |
| 48 | * Use: Steps the generator. |
| 49 | */ |
| 50 | |
| 51 | static void step(sslprf_ctx *c) |
| 52 | { |
| 53 | octet buf[64]; |
| 54 | size_t n, sz; |
| 55 | octet x; |
| 56 | ghash *h, *hh; |
| 57 | octet *p; |
| 58 | |
| 59 | h = GH_INIT(c->ci); |
| 60 | x = 'A' + c->i - 1; |
| 61 | for (sz = c->i++; sz > 0; sz -= n) { |
| 62 | n = sz; |
| 63 | if (n > sizeof(buf)) |
| 64 | n = sizeof(buf); |
| 65 | memset(buf, x, n); |
| 66 | GH_HASH(h, buf, n); |
| 67 | } |
| 68 | GH_HASH(h, c->k, c->ksz); |
| 69 | GH_HASH(h, c->sd, c->sdsz); |
| 70 | p = GH_DONE(h, 0); |
| 71 | |
| 72 | hh = GH_INIT(c->co); |
| 73 | GH_HASH(hh, c->k, c->ksz); |
| 74 | GH_HASH(hh, p, c->ihashsz); |
| 75 | c->p = GH_DONE(hh, 0); |
| 76 | GH_DESTROY(h); |
| 77 | |
| 78 | c->h = hh; |
| 79 | c->sz = c->ohashsz; |
| 80 | } |
| 81 | |
| 82 | /* --- @sslprf_init@ --- * |
| 83 | * |
| 84 | * Arguments: @sslprf_ctx *c@ = pointer to a context structure |
| 85 | * @const gchash *hco, *hci@ = outer and inner hash functions |
| 86 | * @const void *k@ = pointer to secret buffer |
| 87 | * @size_t ksz@ = size of the secret |
| 88 | * @const void *sd@ = pointer to seed buffer |
| 89 | * @size_t sdsz@ = size of the seed |
| 90 | * |
| 91 | * Returns: --- |
| 92 | * |
| 93 | * Use: Initializes an SSL generator context. |
| 94 | */ |
| 95 | |
| 96 | void sslprf_init(sslprf_ctx *c, const gchash *hco, const gchash *hci, |
| 97 | const void *k, size_t ksz, |
| 98 | const void *sd, size_t sdsz) |
| 99 | { |
| 100 | c->co = hco; c->ci = hci; |
| 101 | c->ohashsz = hco->hashsz; c->ihashsz = hci->hashsz; |
| 102 | c->k = k; c->ksz = ksz; c->sd = sd; c->sdsz = sdsz; |
| 103 | c->i = 1; |
| 104 | step(c); |
| 105 | } |
| 106 | |
| 107 | /* --- @sslprf_encrypt@ --- * |
| 108 | * |
| 109 | * Arguments: @sslprf_ctx *c@ = pointer to a context structure |
| 110 | * @const void *src@ = pointer to source buffer |
| 111 | * @void *dest@ = pointer to destination buffer |
| 112 | * @size_t sz@ = size of the buffers |
| 113 | * |
| 114 | * Returns: --- |
| 115 | * |
| 116 | * Use: Encrypts data using the SSL pseudo-random function. If the |
| 117 | * destination pointer is null, the generator is spun and no |
| 118 | * output is produced; if the source pointer is null, raw output |
| 119 | * from the generator is written; otherwise, the source data is |
| 120 | * XORed with the generator output. |
| 121 | */ |
| 122 | |
| 123 | void sslprf_encrypt(sslprf_ctx *c, const void *src, void *dest, size_t sz) |
| 124 | { |
| 125 | const octet *s = src; |
| 126 | octet *d = dest; |
| 127 | size_t i, n; |
| 128 | |
| 129 | while (sz) { |
| 130 | if (!c->sz) { |
| 131 | GH_DESTROY(c->h); |
| 132 | step(c); |
| 133 | } |
| 134 | n = c->sz; |
| 135 | if (n > sz) |
| 136 | n = sz; |
| 137 | if (d) { |
| 138 | if (!s) |
| 139 | memcpy(d, c->p, n); |
| 140 | else { |
| 141 | for (i = 0; i < n; i++) d[i] = s[i] ^ c->p[i]; |
| 142 | s += n; |
| 143 | } |
| 144 | d += n; |
| 145 | } |
| 146 | c->p += n; |
| 147 | c->sz -= n; |
| 148 | sz -= n; |
| 149 | } |
| 150 | } |
| 151 | |
| 152 | /* --- @sslprf_free@ --- * |
| 153 | * |
| 154 | * Arguments: @sslprf_ctx@ = pointer to a context |
| 155 | * |
| 156 | * Returns: --- |
| 157 | * |
| 158 | * Use: Frees resources held in an SSL generator context. |
| 159 | */ |
| 160 | |
| 161 | void sslprf_free(sslprf_ctx *c) |
| 162 | { |
| 163 | GH_DESTROY(c->h); |
| 164 | } |
| 165 | |
| 166 | /* --- Generic random number generator --- */ |
| 167 | |
| 168 | typedef struct grctx { |
| 169 | grand r; |
| 170 | grand_ops ops; |
| 171 | sslprf_ctx prf; |
| 172 | } grctx; |
| 173 | |
| 174 | static void grdestroy(grand *r) |
| 175 | { |
| 176 | grctx *g = (grctx *)r; |
| 177 | xfree((char *)g->ops.name); |
| 178 | xfree((octet *)g->prf.sd); |
| 179 | sslprf_free(&g->prf); |
| 180 | BURN(*g); |
| 181 | S_DESTROY(g); |
| 182 | } |
| 183 | |
| 184 | static void seed(grctx *g, const void *p, size_t sz) |
| 185 | { |
| 186 | octet *q; |
| 187 | xfree((octet *)g->prf.sd); |
| 188 | g->prf.sd = q = xmalloc(sz); |
| 189 | memcpy(q, p, sz); |
| 190 | g->prf.sdsz = sz; |
| 191 | } |
| 192 | |
| 193 | static int grmisc(grand *r, unsigned op, ...) |
| 194 | { |
| 195 | grctx *g = (grctx *)r; |
| 196 | va_list ap; |
| 197 | int rc = 0; |
| 198 | uint32 i; |
| 199 | octet buf[4]; |
| 200 | va_start(ap, op); |
| 201 | |
| 202 | switch (op) { |
| 203 | case GRAND_CHECK: |
| 204 | switch (va_arg(ap, unsigned)) { |
| 205 | case GRAND_CHECK: |
| 206 | case GRAND_SEEDINT: |
| 207 | case GRAND_SEEDUINT32: |
| 208 | case GRAND_SEEDBLOCK: |
| 209 | case GRAND_SEEDRAND: |
| 210 | rc = 1; |
| 211 | break; |
| 212 | default: |
| 213 | rc = 0; |
| 214 | break; |
| 215 | } |
| 216 | break; |
| 217 | case GRAND_SEEDINT: |
| 218 | i = va_arg(ap, unsigned); |
| 219 | STORE32(buf, i); |
| 220 | seed(g, buf, sizeof(buf)); |
| 221 | break; |
| 222 | case GRAND_SEEDUINT32: |
| 223 | i = va_arg(ap, uint32); |
| 224 | STORE32(buf, i); |
| 225 | seed(g, buf, sizeof(buf)); |
| 226 | break; |
| 227 | case GRAND_SEEDBLOCK: { |
| 228 | const void *p = va_arg(ap, const void *); |
| 229 | size_t sz = va_arg(ap, size_t); |
| 230 | seed(g, p, sz); |
| 231 | } break; |
| 232 | case GRAND_SEEDRAND: { |
| 233 | grand *rr = va_arg(ap, grand *); |
| 234 | octet buf[16]; |
| 235 | rr->ops->fill(rr, buf, sizeof(buf)); |
| 236 | seed(g, buf, sizeof(buf)); |
| 237 | } break; |
| 238 | default: |
| 239 | GRAND_BADOP; |
| 240 | break; |
| 241 | } |
| 242 | |
| 243 | va_end(ap); |
| 244 | return (rc); |
| 245 | } |
| 246 | |
| 247 | static octet grbyte(grand *r) |
| 248 | { |
| 249 | grctx *g = (grctx *)r; |
| 250 | octet o; |
| 251 | sslprf_encrypt(&g->prf, 0, &o, 1); |
| 252 | return (o); |
| 253 | } |
| 254 | |
| 255 | static uint32 grword(grand *r) |
| 256 | { |
| 257 | grctx *g = (grctx *)r; |
| 258 | octet b[4]; |
| 259 | sslprf_encrypt(&g->prf, 0, &b, sizeof(b)); |
| 260 | return (LOAD32(b)); |
| 261 | } |
| 262 | |
| 263 | static void grfill(grand *r, void *p, size_t sz) |
| 264 | { |
| 265 | grctx *g = (grctx *)r; |
| 266 | sslprf_encrypt(&g->prf, 0, p, sz); |
| 267 | } |
| 268 | |
| 269 | static const grand_ops grops = { |
| 270 | "<sslprf-dummy>", |
| 271 | GRAND_CRYPTO, 0, |
| 272 | grmisc, grdestroy, |
| 273 | grword, grbyte, grword, grand_defaultrange, grfill |
| 274 | }; |
| 275 | |
| 276 | /* ---@sslprf_rand@ --- * |
| 277 | * |
| 278 | * Arguments: @const gchash *hco, const gchash *hci@ = hash functions |
| 279 | * @const void *k@ = pointer to the key material |
| 280 | * @size_t ksz@ = size of the key material |
| 281 | * @const void *sd@ = pointer to the seed material |
| 282 | * @size_t sdsz@ = size of the seed material |
| 283 | * |
| 284 | * Returns: Pointer to generic random number generator interface. |
| 285 | * |
| 286 | * Use: Creates a generic generator which does TLS data expansion. |
| 287 | */ |
| 288 | |
| 289 | grand *sslprf_rand(const gchash *hco, const gchash *hci, |
| 290 | const void *k, size_t ksz, |
| 291 | const void *sd, size_t sdsz) |
| 292 | { |
| 293 | grctx *g = S_CREATE(grctx); |
| 294 | dstr d = DSTR_INIT; |
| 295 | octet *q = xmalloc(sdsz); |
| 296 | memcpy(q, sd, sdsz); |
| 297 | dstr_putf(&d, "sslprf(%s,%s)", hco->name, hci->name); |
| 298 | g->ops = grops; |
| 299 | g->ops.name = xstrdup(d.buf); |
| 300 | g->r.ops = &g->ops; |
| 301 | dstr_destroy(&d); |
| 302 | sslprf_init(&g->prf, hco, hci, k, ksz, q, sdsz); |
| 303 | return (&g->r); |
| 304 | } |
| 305 | |
| 306 | /*----- Test rig ----------------------------------------------------------*/ |
| 307 | |
| 308 | #ifdef TEST_RIG |
| 309 | |
| 310 | #include <stdio.h> |
| 311 | #include <string.h> |
| 312 | |
| 313 | #include <mLib/quis.h> |
| 314 | #include <mLib/testrig.h> |
| 315 | |
| 316 | #include "sha.h" |
| 317 | #include "md5.h" |
| 318 | |
| 319 | static int v_generate(dstr *v) |
| 320 | { |
| 321 | grand *g; |
| 322 | dstr d = DSTR_INIT; |
| 323 | int ok = 1; |
| 324 | |
| 325 | g = sslprf_rand(&md5, &sha, v[0].buf, v[0].len, v[1].buf, v[1].len); |
| 326 | dstr_ensure(&d, v[2].len); |
| 327 | d.len = v[2].len; |
| 328 | g->ops->fill(g, d.buf, d.len); |
| 329 | g->ops->destroy(g); |
| 330 | if (memcmp(v[2].buf, d.buf, d.len) != 0) { |
| 331 | ok = 0; |
| 332 | printf("\nfail sslprf:" |
| 333 | "\n\tkey = "); |
| 334 | type_hex.dump(&v[0], stdout); |
| 335 | printf("\n\tseed = "); type_hex.dump(&v[1], stdout); |
| 336 | printf("\n\texpected = "); type_hex.dump(&v[2], stdout); |
| 337 | printf("\n\tcalculated = "); type_hex.dump(&d, stdout); |
| 338 | putchar('\n'); |
| 339 | } |
| 340 | return (ok); |
| 341 | } |
| 342 | |
| 343 | static test_chunk defs[] = { |
| 344 | { "sslprf", v_generate, { &type_hex, &type_hex, &type_hex, 0 } }, |
| 345 | { 0, 0, { 0 } } |
| 346 | }; |
| 347 | |
| 348 | int main(int argc, char *argv[]) |
| 349 | { |
| 350 | test_run(argc, argv, defs, SRCDIR"/t/sslprf"); |
| 351 | return (0); |
| 352 | } |
| 353 | |
| 354 | #endif |
| 355 | |
| 356 | /*----- That's all, folks -------------------------------------------------*/ |