| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * Diffie--Hellman groups |
| 4 | * |
| 5 | * (c) 2017 Straylight/Edgeware |
| 6 | */ |
| 7 | |
| 8 | /*----- Licensing notice --------------------------------------------------* |
| 9 | * |
| 10 | * This file is part of Trivial IP Encryption (TrIPE). |
| 11 | * |
| 12 | * TrIPE is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU General Public License as published by |
| 14 | * the Free Software Foundation; either version 2 of the License, or |
| 15 | * (at your option) any later version. |
| 16 | * |
| 17 | * TrIPE 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 General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU General Public License |
| 23 | * along with TrIPE; if not, write to the Free Software Foundation, |
| 24 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 25 | */ |
| 26 | |
| 27 | /*----- Header files ------------------------------------------------------*/ |
| 28 | |
| 29 | #include "tripe.h" |
| 30 | |
| 31 | /*----- Common utilities --------------------------------------------------*/ |
| 32 | |
| 33 | /* --- @KLOAD@ --- * |
| 34 | * |
| 35 | * Arguments: @pre@ = prefix for defined functions |
| 36 | * @ty@, @TY@ = key type name (lower- and upper-case) |
| 37 | * @setgroup@ = code to initialize @kd->g@ |
| 38 | * @setpriv@ = code to initialize @kd->kpriv@ |
| 39 | * @setpub@ = code to initialize @kd->kpub@ |
| 40 | * |
| 41 | * Use: Generates the body of one of the (rather tedious) key loading |
| 42 | * functions. See the description of @KEYTYPES@ below for the |
| 43 | * details. |
| 44 | */ |
| 45 | |
| 46 | #define KLOAD_HALF(pre, ty, TY, which, WHICH, setgroup, setpriv, setpub) \ |
| 47 | static int pre##_ld##which(key_file *kf, key *k, key_data *d, \ |
| 48 | kdata *kd, dstr *t, dstr *e) \ |
| 49 | { \ |
| 50 | key_packstruct kps[TY##_##WHICH##FETCHSZ]; \ |
| 51 | key_packdef *kp; \ |
| 52 | ty##_##which p; \ |
| 53 | int rc; \ |
| 54 | \ |
| 55 | /* --- Initialize things we've not set up yet --- */ \ |
| 56 | \ |
| 57 | kd->grp = 0; kd->k = 0; kd->K = 0; \ |
| 58 | \ |
| 59 | /* --- Unpack the key --- */ \ |
| 60 | \ |
| 61 | kp = key_fetchinit(ty##_##which##fetch, kps, &p); \ |
| 62 | if ((rc = key_unpack(kp, d, t)) != 0) { \ |
| 63 | a_format(e, "unpack-failed", "%s", key_strerror(rc), A_END); \ |
| 64 | goto fail; \ |
| 65 | } \ |
| 66 | \ |
| 67 | /* --- Extract the pieces of the key --- */ \ |
| 68 | \ |
| 69 | setgroup; \ |
| 70 | setpriv; \ |
| 71 | setpub; \ |
| 72 | \ |
| 73 | /* --- We win --- */ \ |
| 74 | \ |
| 75 | rc = 0; \ |
| 76 | goto done; \ |
| 77 | \ |
| 78 | fail: \ |
| 79 | if (kd->grp) { \ |
| 80 | if (kd->K) pre##_freege(kd->grp, kd->K); \ |
| 81 | if (kd->k) pre##_freesc(kd->grp, kd->k); \ |
| 82 | pre##_freegrp(kd->grp); \ |
| 83 | } \ |
| 84 | rc = -1; \ |
| 85 | \ |
| 86 | done: \ |
| 87 | key_fetchdone(kp); \ |
| 88 | return (rc); \ |
| 89 | } |
| 90 | |
| 91 | #define KLOAD(pre, ty, TY, setgroup, setpriv, setpub) \ |
| 92 | static void pre##_freegrp(dhgrp *); \ |
| 93 | static void pre##_freesc(const dhgrp *, dhsc *); \ |
| 94 | static void pre##_freege(const dhgrp *, dhge *); \ |
| 95 | KLOAD_HALF(pre, ty, TY, priv, PRIV, setgroup, setpriv, setpub) \ |
| 96 | KLOAD_HALF(pre, ty, TY, pub, PUB, setgroup, { kd->k = 0; }, setpub) |
| 97 | |
| 98 | #ifndef NTRACE |
| 99 | static void setupstr(mptext_stringctx *sc) |
| 100 | { sc->buf = (char *)buf_u; sc->lim = sc->buf + sizeof(buf_u); } |
| 101 | |
| 102 | static const char *donestr(mptext_stringctx *sc) |
| 103 | { *sc->buf = 0; return ((const char *)buf_u); } |
| 104 | |
| 105 | static void addlitstr(const char *p, mptext_stringctx *sc) |
| 106 | { mptext_stringops.put(p, strlen(p), sc); } |
| 107 | |
| 108 | static void addmpstr(mp *x, int radix, mptext_stringctx *sc) |
| 109 | { |
| 110 | char b[12]; |
| 111 | |
| 112 | if (radix == 16) addlitstr("0x", sc); |
| 113 | else if (radix == 8) addlitstr("0", sc); |
| 114 | else if (radix != 10) { sprintf(b, "%d#", radix); addlitstr(b, sc); } |
| 115 | mp_write(x, radix, &mptext_stringops, sc); |
| 116 | } |
| 117 | |
| 118 | static const char *mpstr(mp *x, int radix) |
| 119 | { |
| 120 | mptext_stringctx sc; |
| 121 | |
| 122 | setupstr(&sc); |
| 123 | addmpstr(x, radix, &sc); |
| 124 | return (donestr(&sc)); |
| 125 | } |
| 126 | #endif |
| 127 | |
| 128 | /*----- Schnorr groups ----------------------------------------------------*/ |
| 129 | |
| 130 | typedef struct intdh_grp { |
| 131 | dhgrp _g; |
| 132 | mpmont mm; |
| 133 | mp *q, *G; |
| 134 | size_t gesz; |
| 135 | } intdh_grp; |
| 136 | |
| 137 | typedef struct intdh_sc { mp *x; } intdh_sc; |
| 138 | typedef struct intdh_ge { mp *X; } intdh_ge; |
| 139 | |
| 140 | static dhgrp *intdh_mkgroup(const dh_param *dp) |
| 141 | { |
| 142 | intdh_grp *g = CREATE(intdh_grp); |
| 143 | g->_g.scsz = mp_octets(dp->q); |
| 144 | g->gesz = mp_octets(dp->p); |
| 145 | mpmont_create(&g->mm, dp->p); |
| 146 | g->q = MP_COPY(dp->q); |
| 147 | g->G = mpmont_mul(&g->mm, MP_NEW, dp->g, g->mm.r2); |
| 148 | return (&g->_g); |
| 149 | } |
| 150 | |
| 151 | static dhsc *intdh_mptosc(const dhgrp *gg, mp *z) |
| 152 | { |
| 153 | const intdh_grp *g = (const intdh_grp *)gg; |
| 154 | intdh_sc *x = CREATE(intdh_sc); |
| 155 | x->x = MP_NEW; mp_div(0, &x->x, z, g->q); |
| 156 | return ((dhsc *)x); |
| 157 | } |
| 158 | |
| 159 | static dhge *intdh_mptoge(const dhgrp *gg, mp *z) |
| 160 | { |
| 161 | const intdh_grp *g = (const intdh_grp *)gg; |
| 162 | intdh_ge *Y = CREATE(intdh_ge); |
| 163 | mp *t = MP_NEW; mp_div(0, &t, z, g->mm.m); |
| 164 | Y->X = mpmont_mul(&g->mm, t, t, g->mm.r2); |
| 165 | return ((dhge *)Y); |
| 166 | } |
| 167 | |
| 168 | KLOAD(intdh, dh, DH, |
| 169 | { kd->grp = intdh_mkgroup(&p.dp); }, |
| 170 | { kd->k = intdh_mptosc(kd->grp, p.x); }, |
| 171 | { kd->K = intdh_mptoge(kd->grp, p.y); }) |
| 172 | |
| 173 | static const char *intdh_checkgrp(const dhgrp *gg) |
| 174 | { |
| 175 | const intdh_grp *g = (const intdh_grp *)gg; |
| 176 | mp *t = MP_NEW; |
| 177 | |
| 178 | if (!pgen_primep(g->mm.m, &rand_global)) return ("p is not prime"); |
| 179 | if (!pgen_primep(g->q, &rand_global)) return ("q is not prime"); |
| 180 | mp_div(0, &t, g->mm.m, g->q); |
| 181 | if (!MP_EQ(t, MP_ONE)) return ("q is not a subgroup order"); |
| 182 | t = mpmont_expr(&g->mm, t, g->G, g->q); |
| 183 | if (!MP_EQ(t, g->mm.r)) return ("g not in the subgroup"); |
| 184 | return (0); |
| 185 | } |
| 186 | |
| 187 | static void intdh_grpinfo(const dhgrp *gg, admin *adm) |
| 188 | { |
| 189 | const intdh_grp *g = (const intdh_grp *)gg; |
| 190 | a_info(adm, |
| 191 | "kx-group=prime", |
| 192 | "kx-group-order-bits=%lu", (unsigned long)mp_bits(g->q), |
| 193 | "kx-group-elt-bits=%lu", (unsigned long)mp_bits(g->mm.m), |
| 194 | A_END); |
| 195 | } |
| 196 | |
| 197 | #ifndef NTRACE |
| 198 | static void intdh_tracegrp(const dhgrp *gg) |
| 199 | { |
| 200 | const intdh_grp *g = (const intdh_grp *)gg; |
| 201 | mp *t = MP_NEW; |
| 202 | trace(T_CRYPTO, "crypto: group type `dh'"); |
| 203 | trace(T_CRYPTO, "crypto: p = %s", mpstr(g->mm.m, 10)); |
| 204 | trace(T_CRYPTO, "crypto: q = %s", mpstr(g->q, 10)); |
| 205 | t = mpmont_reduce(&g->mm, t, g->G); |
| 206 | trace(T_CRYPTO, "crypto: g = %s", mpstr(t, 10)); |
| 207 | MP_DROP(t); |
| 208 | } |
| 209 | #endif |
| 210 | |
| 211 | static int intdh_samegrpp(const dhgrp *gg, const dhgrp *hh) |
| 212 | { |
| 213 | const intdh_grp *g = (const intdh_grp *)gg, *h = (const intdh_grp *)hh; |
| 214 | return (MP_EQ(g->mm.m, h->mm.m) && MP_EQ(g->q, h->q) && MP_EQ(g->G, h->G)); |
| 215 | } |
| 216 | |
| 217 | static void intdh_freegrp(dhgrp *gg) |
| 218 | { |
| 219 | intdh_grp *g = (intdh_grp *)gg; |
| 220 | mpmont_destroy(&g->mm); MP_DROP(g->q); MP_DROP(g->G); |
| 221 | DESTROY(g); |
| 222 | } |
| 223 | |
| 224 | static dhsc *intdh_ldsc(const dhgrp *gg, const void *p, size_t sz) |
| 225 | { const intdh_grp *g = (const intdh_grp *)gg; |
| 226 | intdh_sc *x = CREATE(intdh_sc); |
| 227 | mp *t = mp_loadb(MP_NEW, p, sz); |
| 228 | mp_div(0, &t, t, g->q); x->x = t; |
| 229 | return ((dhsc *)x); |
| 230 | } |
| 231 | |
| 232 | static int intdh_stsc(const dhgrp *gg, void *p, size_t sz, const dhsc *xx) |
| 233 | { |
| 234 | const intdh_sc *x = (const intdh_sc *)xx; |
| 235 | mp_storeb(x->x, p, sz); |
| 236 | return (0); |
| 237 | } |
| 238 | |
| 239 | static dhsc *intdh_randsc(const dhgrp *gg) |
| 240 | { |
| 241 | const intdh_grp *g = (const intdh_grp *)gg; |
| 242 | intdh_sc *x = CREATE(intdh_sc); |
| 243 | x->x = mprand_range(MP_NEW, g->q, &rand_global, 0); |
| 244 | return ((dhsc *)x); |
| 245 | } |
| 246 | |
| 247 | #ifndef NTRACE |
| 248 | static const char *intdh_scstr(const dhgrp *gg, const dhsc *xx) |
| 249 | { const intdh_sc *x = (const intdh_sc *)xx; return (mpstr(x->x, 10)); } |
| 250 | #endif |
| 251 | |
| 252 | static void intdh_freesc(const dhgrp *gg, dhsc *xx) |
| 253 | { |
| 254 | intdh_sc *x = (intdh_sc *)xx; |
| 255 | MP_DROP(x->x); DESTROY(x); |
| 256 | } |
| 257 | |
| 258 | static dhge *intdh_ldge(const dhgrp *gg, buf *b, int fmt) |
| 259 | { |
| 260 | const intdh_grp *g = (const intdh_grp *)gg; |
| 261 | intdh_ge *Y; |
| 262 | mp *t; |
| 263 | const octet *p; |
| 264 | |
| 265 | switch (fmt) { |
| 266 | case DHFMT_VAR: case DHFMT_HASH: |
| 267 | if ((t = buf_getmp(b)) == 0) return (0); |
| 268 | break; |
| 269 | case DHFMT_STD: |
| 270 | if ((p = buf_get(b, g->gesz)) == 0) return (0); |
| 271 | t = mp_loadb(MP_NEW, p, g->gesz); |
| 272 | break; |
| 273 | default: |
| 274 | abort(); |
| 275 | } |
| 276 | Y = CREATE(intdh_ge); |
| 277 | mp_div(0, &t, t, g->mm.m); |
| 278 | Y->X = mpmont_mul(&g->mm, t, t, g->mm.r2); |
| 279 | return ((dhge *)Y); |
| 280 | } |
| 281 | |
| 282 | static int intdh_stge(const dhgrp *gg, buf *b, const dhge *YY, int fmt) |
| 283 | { |
| 284 | const intdh_grp *g = (const intdh_grp *)gg; |
| 285 | const intdh_ge *Y = (const intdh_ge *)YY; |
| 286 | octet *p; |
| 287 | mp *t; |
| 288 | int rc; |
| 289 | |
| 290 | t = mpmont_reduce(&g->mm, MP_NEW, Y->X); |
| 291 | switch (fmt) { |
| 292 | case DHFMT_VAR: case DHFMT_HASH: |
| 293 | rc = buf_putmp(b, t); |
| 294 | break; |
| 295 | case DHFMT_STD: |
| 296 | if ((p = buf_get(b, g->gesz)) == 0) |
| 297 | rc = -1; |
| 298 | else { |
| 299 | mp_storeb(t, p, g->gesz); |
| 300 | rc = 0; |
| 301 | } |
| 302 | break; |
| 303 | default: |
| 304 | abort(); |
| 305 | } |
| 306 | MP_DROP(t); |
| 307 | return (rc); |
| 308 | } |
| 309 | |
| 310 | static int intdh_checkge(const dhgrp *gg, const dhge *YY) |
| 311 | { |
| 312 | const intdh_grp *g = (const intdh_grp *)gg; |
| 313 | const intdh_ge *Y = (const intdh_ge *)YY; |
| 314 | mp *T; |
| 315 | int rc = 0; |
| 316 | |
| 317 | if (MP_EQ(Y->X, g->mm.r)) rc = -1; |
| 318 | T = mpmont_expr(&g->mm, MP_NEW, Y->X, g->q); |
| 319 | if (!MP_EQ(T, g->mm.r)) rc = -1; |
| 320 | MP_DROP(T); |
| 321 | return (rc); |
| 322 | } |
| 323 | |
| 324 | static int intdh_eq(const dhgrp *gg, const dhge *YY, const dhge *ZZ) |
| 325 | { |
| 326 | const intdh_ge *Y = (const intdh_ge *)YY, *Z = (const intdh_ge *)ZZ; |
| 327 | return (MP_EQ(Y->X, Z->X)); |
| 328 | } |
| 329 | |
| 330 | static dhge *intdh_mul(const dhgrp *gg, const dhsc *xx, const dhge *YY) |
| 331 | { |
| 332 | const intdh_grp *g = (const intdh_grp *)gg; |
| 333 | const intdh_sc *x = (const intdh_sc *)xx; |
| 334 | const intdh_ge *Y = (const intdh_ge *)YY; |
| 335 | intdh_ge *Z = CREATE(intdh_ge); |
| 336 | |
| 337 | Z->X = mpmont_expr(&g->mm, MP_NEW, Y ? Y->X : g->G, x->x); |
| 338 | return ((dhge *)Z); |
| 339 | } |
| 340 | |
| 341 | #ifndef NTRACE |
| 342 | static const char *intdh_gestr(const dhgrp *gg, const dhge *YY) |
| 343 | { |
| 344 | const intdh_grp *g = (const intdh_grp *)gg; |
| 345 | const intdh_ge *Y = (const intdh_ge *)YY; |
| 346 | mp *t = mpmont_reduce(&g->mm, MP_NEW, Y->X); |
| 347 | const char *p = mpstr(t, 10); |
| 348 | MP_DROP(t); |
| 349 | return (p); |
| 350 | } |
| 351 | #endif |
| 352 | |
| 353 | static void intdh_freege(const dhgrp *gg, dhge *YY) |
| 354 | { intdh_ge *Y = (intdh_ge *)YY; MP_DROP(Y->X); DESTROY(Y); } |
| 355 | |
| 356 | /*----- Elliptic curve groups ---------------------------------------------*/ |
| 357 | |
| 358 | typedef struct ecdh_grp { |
| 359 | dhgrp _g; |
| 360 | ec_info ei; |
| 361 | ec P; |
| 362 | } ecdh_grp; |
| 363 | |
| 364 | typedef struct ecdh_sc { mp *x; } ecdh_sc; |
| 365 | typedef struct ecdh_ge { ec Q; } ecdh_ge; |
| 366 | |
| 367 | static dhgrp *ecdh_mkgroup(const char *cstr, dstr *e) |
| 368 | { |
| 369 | ecdh_grp *g; |
| 370 | ec_info ei; |
| 371 | const char *err; |
| 372 | |
| 373 | if ((err = ec_getinfo(&ei, cstr)) != 0) { |
| 374 | a_format(e, "decode-failed", "%s", err, A_END); |
| 375 | return (0); |
| 376 | } |
| 377 | g = CREATE(ecdh_grp); |
| 378 | g->ei = ei; |
| 379 | EC_CREATE(&g->P); EC_IN(g->ei.c, &g->P, &g->ei.g); |
| 380 | g->_g.scsz = mp_octets(g->ei.r); |
| 381 | return (&g->_g); |
| 382 | } |
| 383 | |
| 384 | static dhsc *ecdh_mptosc(const dhgrp *gg, mp *z) |
| 385 | { |
| 386 | const ecdh_grp *g = (const ecdh_grp *)gg; |
| 387 | ecdh_sc *x = CREATE(ecdh_sc); |
| 388 | x->x = MP_NEW; mp_div(0, &x->x, z, g->ei.r); |
| 389 | return ((dhsc *)x); |
| 390 | } |
| 391 | |
| 392 | static dhge *ecdh_ectoge(const dhgrp *gg, ec *Q) |
| 393 | { |
| 394 | const ecdh_grp *g = (const ecdh_grp *)gg; |
| 395 | ecdh_ge *Y = CREATE(ecdh_ge); EC_CREATE(&Y->Q); |
| 396 | EC_IN(g->ei.c, &Y->Q, Q); |
| 397 | if (EC_CHECK(g->ei.c, &Y->Q)) |
| 398 | { EC_DESTROY(&Y->Q); DESTROY(Y); return (0); } |
| 399 | return ((dhge *)Y); |
| 400 | } |
| 401 | |
| 402 | KLOAD(ecdh, ec, EC, |
| 403 | { if ((kd->grp = ecdh_mkgroup(p.cstr, e)) == 0) goto fail; }, |
| 404 | { kd->k = ecdh_mptosc(kd->grp, p.x); }, |
| 405 | { if ((kd->K = ecdh_ectoge(kd->grp, &p.p)) == 0) { |
| 406 | a_format(e, "bad-public-vector", A_END); |
| 407 | goto fail; |
| 408 | } |
| 409 | }) |
| 410 | |
| 411 | static const char *ecdh_checkgrp(const dhgrp *gg) |
| 412 | { |
| 413 | const ecdh_grp *g = (const ecdh_grp *)gg; |
| 414 | return (ec_checkinfo(&g->ei, &rand_global)); |
| 415 | } |
| 416 | |
| 417 | static void ecdh_grpinfo(const dhgrp *gg, admin *adm) |
| 418 | { |
| 419 | const ecdh_grp *g = (const ecdh_grp *)gg; |
| 420 | a_info(adm, |
| 421 | "kx-group=ec", |
| 422 | "kx-group-order-bits=%lu", (unsigned long)mp_bits(g->ei.r), |
| 423 | "kx-group-elt-bits=%lu", (unsigned long)2*g->ei.c->f->nbits, |
| 424 | A_END); |
| 425 | } |
| 426 | |
| 427 | #ifndef NTRACE |
| 428 | static void addfestr(field *f, mp *x, mptext_stringctx *sc) |
| 429 | { addmpstr(x, F_TYPE(f) == FTY_PRIME ? 10 : 16, sc); } |
| 430 | |
| 431 | static void addintfestr(field *f, mp *x, mptext_stringctx *sc) |
| 432 | { mp *t = F_OUT(f, MP_NEW, x); addfestr(f, x, sc); MP_DROP(t); } |
| 433 | |
| 434 | static const char *intfestr(field *f, mp *x) |
| 435 | { |
| 436 | mptext_stringctx sc; |
| 437 | setupstr(&sc); |
| 438 | addintfestr(f, x, &sc); |
| 439 | return (donestr(&sc)); |
| 440 | } |
| 441 | |
| 442 | static void ecdh_tracegrp(const dhgrp *gg) |
| 443 | { |
| 444 | const ecdh_grp *g = (const ecdh_grp *)gg; |
| 445 | const ec_curve *c = g->ei.c; |
| 446 | field *f = c->f; |
| 447 | |
| 448 | trace(T_CRYPTO, "crypto: group type `ec'"); |
| 449 | switch (F_TYPE(f)) { |
| 450 | case FTY_PRIME: |
| 451 | trace(T_CRYPTO, "crypto: prime field `%s'", F_NAME(f)); |
| 452 | trace(T_CRYPTO, "crypto: p = %s", mpstr(f->q, 10)); |
| 453 | break; |
| 454 | case FTY_BINARY: |
| 455 | trace(T_CRYPTO, "crypto: binary field `%s'", F_NAME(f)); |
| 456 | trace(T_CRYPTO, "crypto: degree = %lu", f->nbits - 1); |
| 457 | break; |
| 458 | default: |
| 459 | trace(T_CRYPTO, "crypto: unknown field type! `%s'", F_NAME(f)); |
| 460 | break; |
| 461 | } |
| 462 | trace(T_CRYPTO, "crypto: curve type `%s'", EC_NAME(c)); |
| 463 | trace(T_CRYPTO, "crypto: curve a = %s", intfestr(f, c->a)); |
| 464 | trace(T_CRYPTO, "crypto: curve b = %s", intfestr(f, c->b)); |
| 465 | trace(T_CRYPTO, "crypto: n = %s", mpstr(g->ei.r, 10)); |
| 466 | trace(T_CRYPTO, "crypto: h = %s", mpstr(g->ei.h, 10)); |
| 467 | } |
| 468 | #endif |
| 469 | |
| 470 | static int ecdh_samegrpp(const dhgrp *gg, const dhgrp *hh) |
| 471 | { |
| 472 | const ecdh_grp *g = (const ecdh_grp *)gg, *h = (const ecdh_grp *)hh; |
| 473 | return (ec_sameinfop(&g->ei, &h->ei)); |
| 474 | } |
| 475 | |
| 476 | static void ecdh_freegrp(dhgrp *gg) |
| 477 | { |
| 478 | ecdh_grp *g = (ecdh_grp *)gg; |
| 479 | EC_DESTROY(&g->P); ec_freeinfo(&g->ei); |
| 480 | DESTROY(g); |
| 481 | } |
| 482 | |
| 483 | static dhsc *ecdh_ldsc(const dhgrp *gg, const void *p, size_t sz) |
| 484 | { |
| 485 | const ecdh_grp *g = (const ecdh_grp *)gg; |
| 486 | ecdh_sc *x = CREATE(ecdh_sc); |
| 487 | mp *t = mp_loadb(MP_NEW, p, sz); |
| 488 | mp_div(0, &t, t, g->ei.r); x->x = t; |
| 489 | return ((dhsc *)x); |
| 490 | } |
| 491 | |
| 492 | static int ecdh_stsc(const dhgrp *gg, void *p, size_t sz, const dhsc *xx) |
| 493 | { |
| 494 | const ecdh_sc *x = (const ecdh_sc *)xx; |
| 495 | mp_storeb(x->x, p, sz); |
| 496 | return (0); |
| 497 | } |
| 498 | |
| 499 | static dhsc *ecdh_randsc(const dhgrp *gg) |
| 500 | { |
| 501 | const ecdh_grp *g = (const ecdh_grp *)gg; |
| 502 | ecdh_sc *x = CREATE(ecdh_sc); |
| 503 | x->x = mprand_range(MP_NEW, g->ei.r, &rand_global, 0); |
| 504 | return ((dhsc *)x); |
| 505 | } |
| 506 | |
| 507 | #ifndef NTRACE |
| 508 | static const char *ecdh_scstr(const dhgrp *gg, const dhsc *xx) |
| 509 | { |
| 510 | const ecdh_sc *x = (const ecdh_sc *)xx; |
| 511 | return (mpstr(x->x, 10)); |
| 512 | } |
| 513 | #endif |
| 514 | |
| 515 | static void ecdh_freesc(const dhgrp *gg, dhsc *xx) |
| 516 | { ecdh_sc *x = (ecdh_sc *)xx; MP_DROP(x->x); DESTROY(x); } |
| 517 | |
| 518 | static dhge *ecdh_ldge(const dhgrp *gg, buf *b, int fmt) |
| 519 | { |
| 520 | const ecdh_grp *g = (const ecdh_grp *)gg; |
| 521 | ecdh_ge *Y; |
| 522 | ec T = EC_INIT; |
| 523 | |
| 524 | switch (fmt) { |
| 525 | case DHFMT_VAR: case DHFMT_HASH: if (buf_getec(b, &T)) return (0); break; |
| 526 | case DHFMT_STD: if (ec_getraw(g->ei.c, b, &T)) return (0); break; |
| 527 | default: |
| 528 | abort(); |
| 529 | } |
| 530 | EC_IN(g->ei.c, &T, &T); |
| 531 | Y = CREATE(ecdh_ge); Y->Q = T; |
| 532 | return ((dhge *)Y); |
| 533 | } |
| 534 | |
| 535 | static int ecdh_stge(const dhgrp *gg, buf *b, const dhge *YY, int fmt) |
| 536 | { |
| 537 | const ecdh_grp *g = (const ecdh_grp *)gg; |
| 538 | const ecdh_ge *Y = (const ecdh_ge *)YY; |
| 539 | ec T = EC_INIT; |
| 540 | int rc; |
| 541 | |
| 542 | EC_OUT(g->ei.c, &T, &Y->Q); |
| 543 | switch (fmt) { |
| 544 | case DHFMT_VAR: case DHFMT_HASH: rc = buf_putec(b, &T); break; |
| 545 | case DHFMT_STD: rc = ec_putraw(g->ei.c, b, &T); break; |
| 546 | default: abort(); |
| 547 | } |
| 548 | EC_DESTROY(&T); |
| 549 | return (rc); |
| 550 | } |
| 551 | |
| 552 | static int ecdh_checkge(const dhgrp *gg, const dhge *YY) |
| 553 | { |
| 554 | const ecdh_grp *g = (const ecdh_grp *)gg; |
| 555 | const ecdh_ge *Y = (const ecdh_ge *)YY; |
| 556 | ec T = EC_INIT; |
| 557 | int rc = 0; |
| 558 | |
| 559 | if (EC_ATINF(&Y->Q)) rc = -1; |
| 560 | ec_imul(g->ei.c, &T, &Y->Q, g->ei.r); |
| 561 | if (!EC_ATINF(&T)) rc = -1; |
| 562 | EC_DESTROY(&T); |
| 563 | return (rc); |
| 564 | } |
| 565 | |
| 566 | static int ecdh_eq(const dhgrp *gg, const dhge *YY, const dhge *ZZ) |
| 567 | { |
| 568 | const ecdh_grp *g = (const ecdh_grp *)gg; |
| 569 | const ecdh_ge *Y = (const ecdh_ge *)YY, *Z = (const ecdh_ge *)ZZ; |
| 570 | ec T = EC_INIT, U = EC_INIT; int rc; |
| 571 | EC_FIX(g->ei.c, &T, &Y->Q); EC_FIX(g->ei.c, &U, &Z->Q); |
| 572 | rc = EC_EQ(&T, &U); |
| 573 | EC_DESTROY(&T); EC_DESTROY(&U); |
| 574 | return (rc); |
| 575 | } |
| 576 | |
| 577 | static dhge *ecdh_mul(const dhgrp *gg, const dhsc *xx, const dhge *YY) |
| 578 | { |
| 579 | const ecdh_grp *g = (const ecdh_grp *)gg; |
| 580 | const ecdh_sc *x = (const ecdh_sc *)xx; |
| 581 | const ecdh_ge *Y = (const ecdh_ge *)YY; |
| 582 | ecdh_ge *Z = CREATE(ecdh_ge); EC_CREATE(&Z->Q); |
| 583 | |
| 584 | ec_imul(g->ei.c, &Z->Q, Y ? &Y->Q : &g->P, x->x); |
| 585 | return ((dhge *)Z); |
| 586 | } |
| 587 | |
| 588 | #ifndef NTRACE |
| 589 | static const char *ecdh_gestr(const dhgrp *gg, const dhge *YY) |
| 590 | { |
| 591 | const ecdh_grp *g = (const ecdh_grp *)gg; |
| 592 | const ecdh_ge *Y = (const ecdh_ge *)YY; |
| 593 | ec T = EC_INIT; |
| 594 | field *f = g->ei.c->f; |
| 595 | mptext_stringctx sc; |
| 596 | |
| 597 | if (EC_ATINF(&Y->Q)) return ("inf"); |
| 598 | setupstr(&sc); |
| 599 | EC_OUT(g->ei.c, &T, &Y->Q); |
| 600 | addfestr(f, T.x, &sc); |
| 601 | addlitstr(", ", &sc); |
| 602 | addfestr(f, T.y, &sc); |
| 603 | EC_DESTROY(&T); |
| 604 | return (donestr(&sc)); |
| 605 | } |
| 606 | #endif |
| 607 | |
| 608 | static void ecdh_freege(const dhgrp *gg, dhge *YY) |
| 609 | { ecdh_ge *Y = (ecdh_ge *)YY; EC_DESTROY(&Y->Q); DESTROY(Y); } |
| 610 | |
| 611 | /*----- Diffie--Hellman group table ---------------------------------------*/ |
| 612 | |
| 613 | const dhops dhtab[] = { |
| 614 | |
| 615 | #define COMMA , |
| 616 | |
| 617 | #define DH(name, pre) \ |
| 618 | { name, pre##_ldpriv, pre##_ldpub, pre##_checkgrp, \ |
| 619 | pre##_grpinfo, T( pre##_tracegrp COMMA ) pre##_samegrpp, \ |
| 620 | pre##_freegrp, \ |
| 621 | pre##_ldsc, pre##_stsc, pre##_randsc, T( pre##_scstr COMMA ) \ |
| 622 | pre##_freesc, \ |
| 623 | pre##_ldge, pre##_stge, pre##_checkge, pre##_eq, pre##_mul, \ |
| 624 | T( pre##_gestr COMMA ) pre##_freege }, \ |
| 625 | |
| 626 | DH("dh", intdh) |
| 627 | DH("ec", ecdh) |
| 628 | |
| 629 | #undef DH |
| 630 | |
| 631 | { 0 } |
| 632 | }; |
| 633 | |
| 634 | /*----- That's all, folks -------------------------------------------------*/ |