| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * Catcrypt signatures |
| 4 | * |
| 5 | * (c) 2004 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 | #define _FILE_OFFSET_BITS 64 |
| 31 | |
| 32 | #include <stdlib.h> |
| 33 | |
| 34 | #include <mLib/report.h> |
| 35 | |
| 36 | #include "rand.h" |
| 37 | #include "sha.h" |
| 38 | #include "has160.h" |
| 39 | |
| 40 | #include "ec.h" |
| 41 | #include "ec-keys.h" |
| 42 | #include "dh.h" |
| 43 | #include "gdsa.h" |
| 44 | #include "gkcdsa.h" |
| 45 | #include "rsa.h" |
| 46 | |
| 47 | #include "cc.h" |
| 48 | |
| 49 | /*----- Main code ---------------------------------------------------------*/ |
| 50 | |
| 51 | /* --- RSA PKCS1 --- */ |
| 52 | |
| 53 | typedef struct rsap1_sigctx { |
| 54 | sig s; |
| 55 | rsa_privctx rp; |
| 56 | pkcs1 p1; |
| 57 | } rsap1_sigctx; |
| 58 | |
| 59 | static sig *rsap1_siginit(key *k, void *kd, const gchash *hc) |
| 60 | { |
| 61 | rsap1_sigctx *rs = CREATE(rsap1_sigctx); |
| 62 | rsa_privcreate(&rs->rp, kd, &rand_global); |
| 63 | rs->p1.r = &rand_global; |
| 64 | rs->p1.ep = hc->name; |
| 65 | rs->p1.epsz = strlen(hc->name) + 1; |
| 66 | rs->s.h = 0; |
| 67 | return (&rs->s); |
| 68 | } |
| 69 | |
| 70 | static int rsap1_sigdoit(sig *s, dstr *d) |
| 71 | { |
| 72 | rsap1_sigctx *rs = (rsap1_sigctx *)s; |
| 73 | size_t n; |
| 74 | mp *m = rsa_sign(&rs->rp, MP_NEW, |
| 75 | GH_DONE(s->h, 0), GH_CLASS(s->h)->hashsz, |
| 76 | pkcs1_sigencode, &rs->p1); |
| 77 | if (!m) return (-1); |
| 78 | n = mp_octets(rs->rp.rp->n); dstr_ensure(d, n); mp_storeb(m, d->buf, n); |
| 79 | d->len += n; mp_drop(m); |
| 80 | return (0); |
| 81 | } |
| 82 | |
| 83 | static const char *rsa_lengthcheck(mp *n) |
| 84 | { |
| 85 | if (mp_bits(n) < 1024) return ("key too short"); |
| 86 | return (0); |
| 87 | } |
| 88 | |
| 89 | static const char *rsap1_sigcheck(sig *s) |
| 90 | { |
| 91 | rsap1_sigctx *rs = (rsap1_sigctx *)s; |
| 92 | const char *e; |
| 93 | if ((e = rsa_lengthcheck(rs->rp.rp->n)) != 0) return (e); |
| 94 | return (0); |
| 95 | } |
| 96 | |
| 97 | static void rsap1_sigdestroy(sig *s) |
| 98 | { |
| 99 | rsap1_sigctx *rs = (rsap1_sigctx *)s; |
| 100 | rsa_privdestroy(&rs->rp); |
| 101 | DESTROY(rs); |
| 102 | } |
| 103 | |
| 104 | static const sigops rsap1_sig = { |
| 105 | rsa_privfetch, sizeof(rsa_priv), |
| 106 | rsap1_siginit, rsap1_sigdoit, rsap1_sigcheck, rsap1_sigdestroy |
| 107 | }; |
| 108 | |
| 109 | typedef struct rsap1_vrfctx { |
| 110 | sig s; |
| 111 | rsa_pubctx rp; |
| 112 | pkcs1 p1; |
| 113 | } rsap1_vrfctx; |
| 114 | |
| 115 | static sig *rsap1_vrfinit(key *k, void *kd, const gchash *hc) |
| 116 | { |
| 117 | rsap1_vrfctx *rv = CREATE(rsap1_vrfctx); |
| 118 | rsa_pubcreate(&rv->rp, kd); |
| 119 | rv->p1.r = &rand_global; |
| 120 | rv->p1.ep = hc->name; |
| 121 | rv->p1.epsz = strlen(hc->name) + 1; |
| 122 | rv->s.h = 0; |
| 123 | return (&rv->s); |
| 124 | } |
| 125 | |
| 126 | static int rsap1_vrfdoit(sig *s, dstr *d) |
| 127 | { |
| 128 | rsap1_vrfctx *rv = (rsap1_vrfctx *)s; |
| 129 | mp *m = mp_loadb(MP_NEW, d->buf, d->len); |
| 130 | int rc = rsa_verify(&rv->rp, m, |
| 131 | GH_DONE(s->h, 0), GH_CLASS(s->h)->hashsz, |
| 132 | 0, pkcs1_sigdecode, &rv->p1); |
| 133 | mp_drop(m); |
| 134 | return (rc); |
| 135 | } |
| 136 | |
| 137 | static const char *rsap1_vrfcheck(sig *s) |
| 138 | { |
| 139 | rsap1_vrfctx *rv = (rsap1_vrfctx *)s; |
| 140 | const char *e; |
| 141 | if ((e = rsa_lengthcheck(rv->rp.rp->n)) != 0) return (e); |
| 142 | return (0); |
| 143 | } |
| 144 | |
| 145 | static void rsap1_vrfdestroy(sig *s) |
| 146 | { |
| 147 | rsap1_vrfctx *rv = (rsap1_vrfctx *)s; |
| 148 | rsa_pubdestroy(&rv->rp); |
| 149 | DESTROY(rv); |
| 150 | } |
| 151 | |
| 152 | static const sigops rsap1_vrf = { |
| 153 | rsa_pubfetch, sizeof(rsa_pub), |
| 154 | rsap1_vrfinit, rsap1_vrfdoit, rsap1_vrfcheck, rsap1_vrfdestroy |
| 155 | }; |
| 156 | |
| 157 | /* --- RSA PSS --- */ |
| 158 | |
| 159 | static const gccipher *getmgf(key *k, const gchash *hc) |
| 160 | { |
| 161 | dstr d = DSTR_INIT; |
| 162 | const gccipher *gc; |
| 163 | const char *mm; |
| 164 | |
| 165 | if ((mm = key_getattr(0, k, "mgf")) == 0) { |
| 166 | dstr_putf(&d, "%s-mgf", hc->name); |
| 167 | mm = d.buf; |
| 168 | } |
| 169 | if ((gc = gcipher_byname(mm)) == 0) |
| 170 | die(EXIT_FAILURE, "unknown encryption scheme `%s'", mm); |
| 171 | dstr_destroy(&d); |
| 172 | return (gc); |
| 173 | } |
| 174 | |
| 175 | typedef struct rsapss_sigctx { |
| 176 | sig s; |
| 177 | rsa_privctx rp; |
| 178 | pss p; |
| 179 | } rsapss_sigctx; |
| 180 | |
| 181 | static sig *rsapss_siginit(key *k, void *kd, const gchash *hc) |
| 182 | { |
| 183 | rsapss_sigctx *rs = CREATE(rsapss_sigctx); |
| 184 | rsa_privcreate(&rs->rp, kd, &rand_global); |
| 185 | rs->p.r = &rand_global; |
| 186 | rs->p.cc = getmgf(k, hc); |
| 187 | rs->p.ch = hc; |
| 188 | rs->p.ssz = hc->hashsz; |
| 189 | rsa_privdestroy(&rs->rp); |
| 190 | return (&rs->s); |
| 191 | } |
| 192 | |
| 193 | static int rsapss_sigdoit(sig *s, dstr *d) |
| 194 | { |
| 195 | rsapss_sigctx *rs = (rsapss_sigctx *)s; |
| 196 | size_t n; |
| 197 | mp *m = rsa_sign(&rs->rp, MP_NEW, |
| 198 | GH_DONE(s->h, 0), GH_CLASS(s->h)->hashsz, |
| 199 | pss_encode, &rs->p); |
| 200 | if (!m) return (-1); |
| 201 | n = mp_octets(rs->rp.rp->n); dstr_ensure(d, n); mp_storeb(m, d->buf, n); |
| 202 | d->len += n; mp_drop(m); |
| 203 | return (0); |
| 204 | } |
| 205 | |
| 206 | static const char *rsapss_sigcheck(sig *s) |
| 207 | { |
| 208 | rsapss_sigctx *rs = (rsapss_sigctx *)s; |
| 209 | const char *e; |
| 210 | if ((e = rsa_lengthcheck(rs->rp.rp->n)) != 0) return (e); |
| 211 | return (0); |
| 212 | } |
| 213 | |
| 214 | static void rsapss_sigdestroy(sig *s) |
| 215 | { |
| 216 | rsapss_sigctx *rs = (rsapss_sigctx *)s; |
| 217 | rsa_privdestroy(&rs->rp); |
| 218 | DESTROY(rs); |
| 219 | } |
| 220 | |
| 221 | static const sigops rsapss_sig = { |
| 222 | rsa_privfetch, sizeof(rsa_priv), |
| 223 | rsapss_siginit, rsapss_sigdoit, rsapss_sigcheck, rsapss_sigdestroy |
| 224 | }; |
| 225 | |
| 226 | typedef struct rsapss_vrfctx { |
| 227 | sig s; |
| 228 | rsa_pubctx rp; |
| 229 | pss p; |
| 230 | } rsapss_vrfctx; |
| 231 | |
| 232 | static sig *rsapss_vrfinit(key *k, void *kd, const gchash *hc) |
| 233 | { |
| 234 | rsapss_vrfctx *rv = CREATE(rsapss_vrfctx); |
| 235 | rsa_pubcreate(&rv->rp, kd); |
| 236 | rv->p.r = &rand_global; |
| 237 | rv->p.cc = getmgf(k, hc); |
| 238 | rv->p.ch = hc; |
| 239 | rv->p.ssz = hc->hashsz; |
| 240 | return (&rv->s); |
| 241 | } |
| 242 | |
| 243 | static int rsapss_vrfdoit(sig *s, dstr *d) |
| 244 | { |
| 245 | rsapss_vrfctx *rv = (rsapss_vrfctx *)s; |
| 246 | mp *m = mp_loadb(MP_NEW, d->buf, d->len); |
| 247 | int rc = rsa_verify(&rv->rp, m, |
| 248 | GH_DONE(s->h, 0), GH_CLASS(s->h)->hashsz, |
| 249 | 0, pss_decode, &rv->p); |
| 250 | mp_drop(m); |
| 251 | return (rc); |
| 252 | } |
| 253 | |
| 254 | static const char *rsapss_vrfcheck(sig *s) |
| 255 | { |
| 256 | rsapss_vrfctx *rv = (rsapss_vrfctx *)s; |
| 257 | const char *e; |
| 258 | if ((e = rsa_lengthcheck(rv->rp.rp->n)) != 0) return (e); |
| 259 | return (0); |
| 260 | } |
| 261 | |
| 262 | static void rsapss_vrfdestroy(sig *s) |
| 263 | { |
| 264 | rsapss_vrfctx *rv = (rsapss_vrfctx *)s; |
| 265 | rsa_pubdestroy(&rv->rp); |
| 266 | DESTROY(rv); |
| 267 | } |
| 268 | |
| 269 | static const sigops rsapss_vrf = { |
| 270 | rsa_pubfetch, sizeof(rsa_pub), |
| 271 | rsapss_vrfinit, rsapss_vrfdoit, rsapss_vrfcheck, rsapss_vrfdestroy |
| 272 | }; |
| 273 | |
| 274 | /* --- DSA and ECDSA --- */ |
| 275 | |
| 276 | typedef struct dsa_sigctx { |
| 277 | sig s; |
| 278 | gdsa g; |
| 279 | } dsa_sigctx; |
| 280 | |
| 281 | static void dsa_initcommon(dsa_sigctx *ds, const gchash *hc, |
| 282 | const char *ktag) |
| 283 | { |
| 284 | ds->g.r = &rand_global; |
| 285 | ds->g.h = hc; |
| 286 | ds->g.u = MP_NEW; |
| 287 | ds->s.h = 0; |
| 288 | } |
| 289 | |
| 290 | static dsa_sigctx *dsa_doinit(key *k, const gprime_param *gp, |
| 291 | mp *y, const gchash *hc, |
| 292 | group *(*makegroup)(const gprime_param *), |
| 293 | const char *what) |
| 294 | { |
| 295 | dsa_sigctx *ds = CREATE(dsa_sigctx); |
| 296 | dstr t = DSTR_INIT; |
| 297 | |
| 298 | key_fulltag(k, &t); |
| 299 | if ((ds->g.g = makegroup(gp)) == 0) |
| 300 | die(EXIT_FAILURE, "bad %s group in key `%s'", what, t.buf); |
| 301 | ds->g.p = G_CREATE(ds->g.g); |
| 302 | if (G_FROMINT(ds->g.g, ds->g.p, y)) |
| 303 | die(EXIT_FAILURE, "bad public key in key `%s'", t.buf); |
| 304 | dsa_initcommon(ds, hc, t.buf); |
| 305 | dstr_destroy(&t); |
| 306 | return (ds); |
| 307 | } |
| 308 | |
| 309 | static dsa_sigctx *ecdsa_doinit(key *k, const char *cstr, |
| 310 | ec *y, const gchash *hc) |
| 311 | { |
| 312 | dsa_sigctx *ds = CREATE(dsa_sigctx); |
| 313 | ec_info ei; |
| 314 | const char *e; |
| 315 | dstr t = DSTR_INIT; |
| 316 | |
| 317 | key_fulltag(k, &t); |
| 318 | if ((e = ec_getinfo(&ei, cstr)) != 0) |
| 319 | die(EXIT_FAILURE, "bad curve in key `%s': %s", t.buf, e); |
| 320 | ds->g.g = group_ec(&ei); |
| 321 | ds->g.p = G_CREATE(ds->g.g); |
| 322 | if (G_FROMEC(ds->g.g, ds->g.p, y)) |
| 323 | die(EXIT_FAILURE, "bad public key in key `%s'", t.buf); |
| 324 | dsa_initcommon(ds, hc, t.buf); |
| 325 | dstr_destroy(&t); |
| 326 | return (ds); |
| 327 | } |
| 328 | |
| 329 | static sig *dsa_siginit(key *k, void *kd, const gchash *hc) |
| 330 | { |
| 331 | dh_priv *dp = kd; |
| 332 | dsa_sigctx *ds = dsa_doinit(k, &dp->dp, dp->y, hc, group_prime, "prime"); |
| 333 | ds->g.u = MP_COPY(dp->x); |
| 334 | return (&ds->s); |
| 335 | } |
| 336 | |
| 337 | static sig *bindsa_siginit(key *k, void *kd, const gchash *hc) |
| 338 | { |
| 339 | dh_priv *dp = kd; |
| 340 | dsa_sigctx *ds = dsa_doinit(k, &dp->dp, dp->y, hc, group_binary, "binary"); |
| 341 | ds->g.u = MP_COPY(dp->x); |
| 342 | return (&ds->s); |
| 343 | } |
| 344 | |
| 345 | static sig *ecdsa_siginit(key *k, void *kd, const gchash *hc) |
| 346 | { |
| 347 | ec_priv *ep = kd; |
| 348 | dsa_sigctx *ds = ecdsa_doinit(k, ep->cstr, &ep->p, hc); |
| 349 | ds->g.u = MP_COPY(ep->x); |
| 350 | return (&ds->s); |
| 351 | } |
| 352 | |
| 353 | static int dsa_sigdoit(sig *s, dstr *d) |
| 354 | { |
| 355 | dsa_sigctx *ds = (dsa_sigctx *)s; |
| 356 | gdsa_sig ss = GDSA_SIG_INIT; |
| 357 | size_t n = mp_octets(ds->g.g->r); |
| 358 | |
| 359 | gdsa_sign(&ds->g, &ss, GH_DONE(ds->s.h, 0), 0); |
| 360 | dstr_ensure(d, 2 * n); |
| 361 | mp_storeb(ss.r, d->buf, n); |
| 362 | mp_storeb(ss.s, d->buf + n, n); |
| 363 | d->len += 2 * n; |
| 364 | mp_drop(ss.r); mp_drop(ss.s); |
| 365 | return (0); |
| 366 | } |
| 367 | |
| 368 | static const char *dsa_sigcheck(sig *s) |
| 369 | { |
| 370 | dsa_sigctx *ds = (dsa_sigctx *)s; |
| 371 | const char *e; |
| 372 | if ((e = G_CHECK(ds->g.g, &rand_global)) != 0) |
| 373 | return (0); |
| 374 | if (group_check(ds->g.g, ds->g.p)) |
| 375 | return ("public key not in subgroup"); |
| 376 | return (0); |
| 377 | } |
| 378 | |
| 379 | static void dsa_sigdestroy(sig *s) |
| 380 | { |
| 381 | dsa_sigctx *ds = (dsa_sigctx *)s; |
| 382 | G_DESTROY(ds->g.g, ds->g.p); |
| 383 | mp_drop(ds->g.u); |
| 384 | G_DESTROYGROUP(ds->g.g); |
| 385 | DESTROY(ds); |
| 386 | } |
| 387 | |
| 388 | static const sigops dsa_sig = { |
| 389 | dh_privfetch, sizeof(dh_priv), |
| 390 | dsa_siginit, dsa_sigdoit, dsa_sigcheck, dsa_sigdestroy |
| 391 | }; |
| 392 | |
| 393 | static const sigops bindsa_sig = { |
| 394 | dh_privfetch, sizeof(dh_priv), |
| 395 | bindsa_siginit, dsa_sigdoit, dsa_sigcheck, dsa_sigdestroy |
| 396 | }; |
| 397 | |
| 398 | static const sigops ecdsa_sig = { |
| 399 | ec_privfetch, sizeof(ec_priv), |
| 400 | ecdsa_siginit, dsa_sigdoit, dsa_sigcheck, dsa_sigdestroy |
| 401 | }; |
| 402 | |
| 403 | static sig *dsa_vrfinit(key *k, void *kd, const gchash *hc) |
| 404 | { |
| 405 | dh_pub *dp = kd; |
| 406 | dsa_sigctx *ds = dsa_doinit(k, &dp->dp, dp->y, hc, group_prime, "prime"); |
| 407 | return (&ds->s); |
| 408 | } |
| 409 | |
| 410 | static sig *bindsa_vrfinit(key *k, void *kd, const gchash *hc) |
| 411 | { |
| 412 | dh_pub *dp = kd; |
| 413 | dsa_sigctx *ds = dsa_doinit(k, &dp->dp, dp->y, hc, group_binary, "binary"); |
| 414 | return (&ds->s); |
| 415 | } |
| 416 | |
| 417 | static sig *ecdsa_vrfinit(key *k, void *kd, const gchash *hc) |
| 418 | { |
| 419 | ec_pub *ep = kd; |
| 420 | dsa_sigctx *ds = ecdsa_doinit(k, ep->cstr, &ep->p, hc); |
| 421 | return (&ds->s); |
| 422 | } |
| 423 | |
| 424 | static int dsa_vrfdoit(sig *s, dstr *d) |
| 425 | { |
| 426 | dsa_sigctx *ds = (dsa_sigctx *)s; |
| 427 | gdsa_sig ss; |
| 428 | size_t n = d->len/2; |
| 429 | int rc; |
| 430 | |
| 431 | ss.r = mp_loadb(MP_NEW, d->buf, n); |
| 432 | ss.s = mp_loadb(MP_NEW, d->buf + n, d->len - n); |
| 433 | rc = gdsa_verify(&ds->g, &ss, GH_DONE(ds->s.h, 0)); |
| 434 | mp_drop(ss.r); mp_drop(ss.s); |
| 435 | return (rc); |
| 436 | } |
| 437 | |
| 438 | static const sigops dsa_vrf = { |
| 439 | dh_pubfetch, sizeof(dh_pub), |
| 440 | dsa_vrfinit, dsa_vrfdoit, dsa_sigcheck, dsa_sigdestroy |
| 441 | }; |
| 442 | |
| 443 | static const sigops bindsa_vrf = { |
| 444 | dh_pubfetch, sizeof(dh_pub), |
| 445 | bindsa_vrfinit, dsa_vrfdoit, dsa_sigcheck, dsa_sigdestroy |
| 446 | }; |
| 447 | |
| 448 | static const sigops ecdsa_vrf = { |
| 449 | ec_pubfetch, sizeof(ec_pub), |
| 450 | ecdsa_vrfinit, dsa_vrfdoit, dsa_sigcheck, dsa_sigdestroy |
| 451 | }; |
| 452 | |
| 453 | /* --- KCDSA and ECKCDSA --- */ |
| 454 | |
| 455 | static void kcdsa_privkey(dsa_sigctx *ds, mp *x) |
| 456 | { ds->g.u = mp_modinv(MP_NEW, x, ds->g.g->r); } |
| 457 | |
| 458 | static void kcdsa_sethash(dsa_sigctx *ds, const gchash *hc) |
| 459 | { ds->s.h = gkcdsa_beginhash(&ds->g); } |
| 460 | |
| 461 | static sig *kcdsa_siginit(key *k, void *kd, const gchash *hc) |
| 462 | { |
| 463 | dh_priv *dp = kd; |
| 464 | dsa_sigctx *ds = dsa_doinit(k, &dp->dp, dp->y, hc, group_prime, "prime"); |
| 465 | kcdsa_privkey(ds, dp->x); |
| 466 | kcdsa_sethash(ds, hc); |
| 467 | return (&ds->s); |
| 468 | } |
| 469 | |
| 470 | static sig *binkcdsa_siginit(key *k, void *kd, const gchash *hc) |
| 471 | { |
| 472 | dh_priv *dp = kd; |
| 473 | dsa_sigctx *ds = dsa_doinit(k, &dp->dp, dp->y, hc, group_binary, "binary"); |
| 474 | kcdsa_privkey(ds, dp->x); |
| 475 | kcdsa_sethash(ds, hc); |
| 476 | return (&ds->s); |
| 477 | } |
| 478 | |
| 479 | static sig *eckcdsa_siginit(key *k, void *kd, const gchash *hc) |
| 480 | { |
| 481 | ec_priv *ep = kd; |
| 482 | dsa_sigctx *ds = ecdsa_doinit(k, ep->cstr, &ep->p, hc); |
| 483 | kcdsa_privkey(ds, ep->x); |
| 484 | kcdsa_sethash(ds, hc); |
| 485 | return (&ds->s); |
| 486 | } |
| 487 | |
| 488 | static int kcdsa_sigdoit(sig *s, dstr *d) |
| 489 | { |
| 490 | dsa_sigctx *ds = (dsa_sigctx *)s; |
| 491 | gkcdsa_sig ss = GKCDSA_SIG_INIT; |
| 492 | size_t hsz = ds->g.h->hashsz, n = mp_octets(ds->g.g->r); |
| 493 | |
| 494 | gkcdsa_sign(&ds->g, &ss, GH_DONE(ds->s.h, 0), 0); |
| 495 | dstr_ensure(d, hsz + n); |
| 496 | memcpy(d->buf, ss.r, hsz); |
| 497 | mp_storeb(ss.s, d->buf + hsz, n); |
| 498 | d->len += hsz + n; |
| 499 | xfree(ss.r); mp_drop(ss.s); |
| 500 | return (0); |
| 501 | } |
| 502 | |
| 503 | static const sigops kcdsa_sig = { |
| 504 | dh_privfetch, sizeof(dh_priv), |
| 505 | kcdsa_siginit, kcdsa_sigdoit, dsa_sigcheck, dsa_sigdestroy |
| 506 | }; |
| 507 | |
| 508 | static const sigops binkcdsa_sig = { |
| 509 | dh_privfetch, sizeof(dh_priv), |
| 510 | binkcdsa_siginit, kcdsa_sigdoit, dsa_sigcheck, dsa_sigdestroy |
| 511 | }; |
| 512 | |
| 513 | static const sigops eckcdsa_sig = { |
| 514 | ec_privfetch, sizeof(ec_priv), |
| 515 | eckcdsa_siginit, kcdsa_sigdoit, dsa_sigcheck, dsa_sigdestroy |
| 516 | }; |
| 517 | |
| 518 | static sig *kcdsa_vrfinit(key *k, void *kd, const gchash *hc) |
| 519 | { |
| 520 | dh_pub *dp = kd; |
| 521 | dsa_sigctx *ds = dsa_doinit(k, &dp->dp, dp->y, hc, group_prime, "prime"); |
| 522 | kcdsa_sethash(ds, hc); |
| 523 | return (&ds->s); |
| 524 | } |
| 525 | |
| 526 | static sig *binkcdsa_vrfinit(key *k, void *kd, const gchash *hc) |
| 527 | { |
| 528 | dh_pub *dp = kd; |
| 529 | dsa_sigctx *ds = dsa_doinit(k, &dp->dp, dp->y, hc, group_binary, "binary"); |
| 530 | kcdsa_sethash(ds, hc); |
| 531 | return (&ds->s); |
| 532 | } |
| 533 | |
| 534 | static sig *eckcdsa_vrfinit(key *k, void *kd, const gchash *hc) |
| 535 | { |
| 536 | ec_pub *ep = kd; |
| 537 | dsa_sigctx *ds = ecdsa_doinit(k, ep->cstr, &ep->p, hc); |
| 538 | kcdsa_sethash(ds, hc); |
| 539 | return (&ds->s); |
| 540 | } |
| 541 | |
| 542 | static int kcdsa_vrfdoit(sig *s, dstr *d) |
| 543 | { |
| 544 | dsa_sigctx *ds = (dsa_sigctx *)s; |
| 545 | gkcdsa_sig ss; |
| 546 | size_t hsz = ds->g.h->hashsz, n = d->len - hsz; |
| 547 | int rc; |
| 548 | |
| 549 | if (d->len < hsz) |
| 550 | return (-1); |
| 551 | ss.r = (octet *)d->buf; |
| 552 | ss.s = mp_loadb(MP_NEW, d->buf + hsz, n); |
| 553 | rc = gkcdsa_verify(&ds->g, &ss, GH_DONE(ds->s.h, 0)); |
| 554 | mp_drop(ss.s); |
| 555 | return (rc); |
| 556 | } |
| 557 | |
| 558 | static const sigops kcdsa_vrf = { |
| 559 | dh_pubfetch, sizeof(dh_pub), |
| 560 | kcdsa_vrfinit, kcdsa_vrfdoit, dsa_sigcheck, dsa_sigdestroy |
| 561 | }; |
| 562 | |
| 563 | static const sigops binkcdsa_vrf = { |
| 564 | dh_pubfetch, sizeof(dh_pub), |
| 565 | binkcdsa_vrfinit, kcdsa_vrfdoit, dsa_sigcheck, dsa_sigdestroy |
| 566 | }; |
| 567 | |
| 568 | static const sigops eckcdsa_vrf = { |
| 569 | ec_pubfetch, sizeof(ec_pub), |
| 570 | eckcdsa_vrfinit, kcdsa_vrfdoit, dsa_sigcheck, dsa_sigdestroy |
| 571 | }; |
| 572 | |
| 573 | /* --- Symmetric message authentication --- */ |
| 574 | |
| 575 | typedef struct mac_ctx { |
| 576 | sig s; |
| 577 | const gcmac *mc; |
| 578 | gmac *m; |
| 579 | key_packdef kp; |
| 580 | key_bin kb; |
| 581 | } mac_ctx; |
| 582 | |
| 583 | static sig *mac_init(key *k, void *kd, const gchash *hc) |
| 584 | { |
| 585 | mac_ctx *m; |
| 586 | dstr d = DSTR_INIT; |
| 587 | int err; |
| 588 | const char *mm; |
| 589 | |
| 590 | m = CREATE(mac_ctx); |
| 591 | |
| 592 | key_fulltag(k, &d); |
| 593 | m->kp.e = KENC_BINARY; |
| 594 | m->kp.p = &m->kb; |
| 595 | m->kp.kd = 0; |
| 596 | |
| 597 | if ((mm = key_getattr(0 /*yik*/, k, "mac")) == 0) { |
| 598 | dstr_putf(&d, "%s-hmac", hc->name); |
| 599 | mm = d.buf; |
| 600 | } |
| 601 | if ((m->mc = gmac_byname(mm)) == 0) |
| 602 | die(EXIT_FAILURE, "unknown message authentication scheme `%s'", mm); |
| 603 | dstr_reset(&d); |
| 604 | |
| 605 | if ((err = key_unpack(&m->kp, kd, &d)) != 0) { |
| 606 | die(EXIT_FAILURE, "failed to unpack symmetric key `%s': %s", |
| 607 | d.buf, key_strerror(err)); |
| 608 | } |
| 609 | dstr_destroy(&d); |
| 610 | |
| 611 | if (keysz(m->kb.sz, m->mc->keysz) != m->kb.sz) { |
| 612 | die(EXIT_FAILURE, "bad key size %lu for `%s'", |
| 613 | (unsigned long)m->kb.sz, m->mc->name); |
| 614 | } |
| 615 | m->m = GM_KEY(m->mc, m->kb.k, m->kb.sz); |
| 616 | m->s.h = GM_INIT(m->m); |
| 617 | return (&m->s); |
| 618 | } |
| 619 | |
| 620 | static int mac_sigdoit(sig *s, dstr *d) |
| 621 | { |
| 622 | mac_ctx *m = (mac_ctx *)s; |
| 623 | |
| 624 | dstr_ensure(d, m->mc->hashsz); |
| 625 | GH_DONE(m->s.h, d->buf); |
| 626 | d->len += m->mc->hashsz; |
| 627 | return (0); |
| 628 | } |
| 629 | |
| 630 | static int mac_vrfdoit(sig *s, dstr *d) |
| 631 | { |
| 632 | mac_ctx *m = (mac_ctx *)s; |
| 633 | const octet *t; |
| 634 | |
| 635 | t = GH_DONE(m->s.h, 0); |
| 636 | if (d->len != m->mc->hashsz || memcmp(d->buf, t, d->len) != 0) |
| 637 | return (-1); |
| 638 | return (0); |
| 639 | } |
| 640 | |
| 641 | static const char *mac_check(sig *s) { return (0); } |
| 642 | |
| 643 | static void mac_destroy(sig *s) |
| 644 | { |
| 645 | mac_ctx *m = (mac_ctx *)s; |
| 646 | GM_DESTROY(m->m); |
| 647 | key_unpackdone(&m->kp); |
| 648 | } |
| 649 | |
| 650 | static const sigops mac_sig = { |
| 651 | 0, 0, |
| 652 | mac_init, mac_sigdoit, mac_check, mac_destroy |
| 653 | }; |
| 654 | |
| 655 | static const sigops mac_vrf = { |
| 656 | 0, 0, |
| 657 | mac_init, mac_vrfdoit, mac_check, mac_destroy |
| 658 | }; |
| 659 | |
| 660 | /* --- The switch table --- */ |
| 661 | |
| 662 | const struct sigtab sigtab[] = { |
| 663 | { "rsapkcs1", &rsap1_sig, &rsap1_vrf, &sha }, |
| 664 | { "rsapss", &rsapss_sig, &rsapss_vrf, &sha }, |
| 665 | { "dsa", &dsa_sig, &dsa_vrf, &sha }, |
| 666 | { "bindsa", &bindsa_sig, &bindsa_vrf, &sha }, |
| 667 | { "ecdsa", &ecdsa_sig, &ecdsa_vrf, &sha }, |
| 668 | { "kcdsa", &kcdsa_sig, &kcdsa_vrf, &has160 }, |
| 669 | { "binkcdsa", &binkcdsa_sig, &binkcdsa_vrf, &has160 }, |
| 670 | { "eckcdsa", &eckcdsa_sig, &eckcdsa_vrf, &has160 }, |
| 671 | { "mac", &mac_sig, &mac_vrf, &rmd160 }, |
| 672 | { 0, 0, 0 } |
| 673 | }; |
| 674 | |
| 675 | /* --- @getsig@ --- * |
| 676 | * |
| 677 | * Arguments: @key *k@ = the key to load |
| 678 | * @const char *app@ = application name |
| 679 | * @int wantpriv@ = nonzero if we want to sign |
| 680 | * |
| 681 | * Returns: A signature-making thing. |
| 682 | * |
| 683 | * Use: Loads a key and starts hashing. |
| 684 | */ |
| 685 | |
| 686 | sig *getsig(key *k, const char *app, int wantpriv) |
| 687 | { |
| 688 | const char *salg, *halg = 0; |
| 689 | dstr d = DSTR_INIT; |
| 690 | dstr t = DSTR_INIT; |
| 691 | char *p = 0; |
| 692 | const char *q; |
| 693 | sig *s; |
| 694 | size_t n; |
| 695 | const struct sigtab *st; |
| 696 | const sigops *so; |
| 697 | const gchash *ch; |
| 698 | void *kd; |
| 699 | int e; |
| 700 | key_packdef *kp; |
| 701 | |
| 702 | /* --- Setup stuff --- */ |
| 703 | |
| 704 | key_fulltag(k, &t); |
| 705 | |
| 706 | /* --- Get the signature algorithm --- * |
| 707 | * |
| 708 | * Take the attribute if it's there; otherwise use the key type. |
| 709 | */ |
| 710 | |
| 711 | n = strlen(app); |
| 712 | if ((q = key_getattr(0, k, "sig")) != 0) { |
| 713 | dstr_puts(&d, q); |
| 714 | p = d.buf; |
| 715 | } else if (strncmp(k->type, app, n) == 0 && k->type[n] == '-') { |
| 716 | dstr_puts(&d, k->type); |
| 717 | p = d.buf + n + 1; |
| 718 | } else |
| 719 | die(EXIT_FAILURE, "no signature algorithm for key `%s'", t.buf); |
| 720 | |
| 721 | /* --- Grab the hash algorithm --- * |
| 722 | * |
| 723 | * Grab it from the signature algorithm if it's there. But override that |
| 724 | * from the attribute. |
| 725 | */ |
| 726 | |
| 727 | salg = p; |
| 728 | if ((p = strchr(p, '/')) != 0) { |
| 729 | *p++ = 0; |
| 730 | halg = p; |
| 731 | } |
| 732 | if ((q = key_getattr(0, k, "hash")) != 0) |
| 733 | halg = q; |
| 734 | |
| 735 | /* --- Look up the algorithms in the table --- */ |
| 736 | |
| 737 | for (st = sigtab; st->name; st++) { |
| 738 | if (strcmp(st->name, salg) == 0) |
| 739 | goto s_found; |
| 740 | } |
| 741 | die(EXIT_FAILURE, "signature algorithm `%s' not found in key `%s'", |
| 742 | salg, t.buf); |
| 743 | s_found:; |
| 744 | if (!halg) |
| 745 | ch = st->ch; |
| 746 | else { |
| 747 | if ((ch = ghash_byname(halg)) == 0) { |
| 748 | die(EXIT_FAILURE, "hash algorithm `%s' not found in key `%s'", |
| 749 | halg, t.buf); |
| 750 | } |
| 751 | } |
| 752 | so = wantpriv ? st->signops : st->verifyops; |
| 753 | |
| 754 | /* --- Load the key --- */ |
| 755 | |
| 756 | if (!so->kf) { |
| 757 | kd = k->k; |
| 758 | key_incref(kd); |
| 759 | kp = 0; |
| 760 | } else { |
| 761 | kd = xmalloc(so->kdsz); |
| 762 | kp = key_fetchinit(so->kf, 0, kd); |
| 763 | if ((e = key_fetch(kp, k)) != 0) { |
| 764 | die(EXIT_FAILURE, "error fetching key `%s': %s", |
| 765 | t.buf, key_strerror(e)); |
| 766 | } |
| 767 | } |
| 768 | s = so->init(k, kd, ch); |
| 769 | if (!s->h) |
| 770 | s->h = GH_INIT(ch); |
| 771 | s->kp = kp; |
| 772 | s->ops = so; |
| 773 | s->kd = kd; |
| 774 | s->ch = ch; |
| 775 | |
| 776 | /* --- Free stuff up --- */ |
| 777 | |
| 778 | dstr_destroy(&d); |
| 779 | dstr_destroy(&t); |
| 780 | return (s); |
| 781 | } |
| 782 | |
| 783 | /* --- @freesig@ --- * |
| 784 | * |
| 785 | * Arguments: @sig *s@ = signature-making thing |
| 786 | * |
| 787 | * Returns: --- |
| 788 | * |
| 789 | * Use: Frees up a signature-making thing |
| 790 | */ |
| 791 | |
| 792 | void freesig(sig *s) |
| 793 | { |
| 794 | GH_DESTROY(s->h); |
| 795 | if (!s->ops->kf) |
| 796 | key_drop(s->kd); |
| 797 | else { |
| 798 | key_fetchdone(s->kp); |
| 799 | xfree(s->kd); |
| 800 | } |
| 801 | s->ops->destroy(s); |
| 802 | } |
| 803 | |
| 804 | /*----- That's all, folks -------------------------------------------------*/ |