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5b9f3d37 MW |
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 | ||
07bdda1f MW |
98 | enum { DHSER_V0, DHSER_CONSTLEN }; |
99 | ||
100 | static int get_serialization(key_file *kf, key *k, dstr *e) | |
101 | { | |
102 | const char *p = key_getattr(kf, k, "serialization"); | |
103 | if (!p || strcmp(p, "v0") == 0) return (DHSER_V0); | |
104 | else if (strcmp(p, "constlen") == 0) return (DHSER_CONSTLEN); | |
105 | else { | |
106 | a_format(e, "unknown-serialization-format", "%s", p, A_END); | |
107 | return (-1); | |
108 | } | |
109 | } | |
110 | ||
5b9f3d37 MW |
111 | #ifndef NTRACE |
112 | static void setupstr(mptext_stringctx *sc) | |
113 | { sc->buf = (char *)buf_u; sc->lim = sc->buf + sizeof(buf_u); } | |
114 | ||
115 | static const char *donestr(mptext_stringctx *sc) | |
116 | { *sc->buf = 0; return ((const char *)buf_u); } | |
117 | ||
118 | static void addlitstr(const char *p, mptext_stringctx *sc) | |
119 | { mptext_stringops.put(p, strlen(p), sc); } | |
120 | ||
121 | static void addmpstr(mp *x, int radix, mptext_stringctx *sc) | |
122 | { | |
123 | char b[12]; | |
124 | ||
125 | if (radix == 16) addlitstr("0x", sc); | |
126 | else if (radix == 8) addlitstr("0", sc); | |
127 | else if (radix != 10) { sprintf(b, "%d#", radix); addlitstr(b, sc); } | |
128 | mp_write(x, radix, &mptext_stringops, sc); | |
129 | } | |
130 | ||
131 | static const char *mpstr(mp *x, int radix) | |
132 | { | |
133 | mptext_stringctx sc; | |
134 | ||
135 | setupstr(&sc); | |
136 | addmpstr(x, radix, &sc); | |
137 | return (donestr(&sc)); | |
138 | } | |
139 | #endif | |
140 | ||
141 | /*----- Schnorr groups ----------------------------------------------------*/ | |
142 | ||
143 | typedef struct intdh_grp { | |
144 | dhgrp _g; | |
145 | mpmont mm; | |
146 | mp *q, *G; | |
147 | size_t gesz; | |
07bdda1f | 148 | int ser; |
5b9f3d37 MW |
149 | } intdh_grp; |
150 | ||
151 | typedef struct intdh_sc { mp *x; } intdh_sc; | |
152 | typedef struct intdh_ge { mp *X; } intdh_ge; | |
153 | ||
07bdda1f MW |
154 | static dhgrp *intdh_mkgroup(key_file *kf, key *k, |
155 | const dh_param *dp, dstr *e) | |
5b9f3d37 | 156 | { |
07bdda1f MW |
157 | intdh_grp *g; |
158 | int ser; | |
159 | ||
160 | if ((ser = get_serialization(kf, k, e)) < 0) return (0); | |
161 | g = CREATE(intdh_grp); | |
162 | g->ser = ser; | |
5b9f3d37 MW |
163 | g->_g.scsz = mp_octets(dp->q); |
164 | g->gesz = mp_octets(dp->p); | |
165 | mpmont_create(&g->mm, dp->p); | |
166 | g->q = MP_COPY(dp->q); | |
167 | g->G = mpmont_mul(&g->mm, MP_NEW, dp->g, g->mm.r2); | |
168 | return (&g->_g); | |
169 | } | |
170 | ||
171 | static dhsc *intdh_mptosc(const dhgrp *gg, mp *z) | |
172 | { | |
173 | const intdh_grp *g = (const intdh_grp *)gg; | |
174 | intdh_sc *x = CREATE(intdh_sc); | |
175 | x->x = MP_NEW; mp_div(0, &x->x, z, g->q); | |
176 | return ((dhsc *)x); | |
177 | } | |
178 | ||
179 | static dhge *intdh_mptoge(const dhgrp *gg, mp *z) | |
180 | { | |
181 | const intdh_grp *g = (const intdh_grp *)gg; | |
182 | intdh_ge *Y = CREATE(intdh_ge); | |
183 | mp *t = MP_NEW; mp_div(0, &t, z, g->mm.m); | |
184 | Y->X = mpmont_mul(&g->mm, t, t, g->mm.r2); | |
185 | return ((dhge *)Y); | |
186 | } | |
187 | ||
188 | KLOAD(intdh, dh, DH, | |
07bdda1f | 189 | { if ((kd->grp = intdh_mkgroup(kf, k, &p.dp, e)) == 0) goto fail; }, |
5b9f3d37 MW |
190 | { kd->k = intdh_mptosc(kd->grp, p.x); }, |
191 | { kd->K = intdh_mptoge(kd->grp, p.y); }) | |
192 | ||
193 | static const char *intdh_checkgrp(const dhgrp *gg) | |
194 | { | |
195 | const intdh_grp *g = (const intdh_grp *)gg; | |
196 | mp *t = MP_NEW; | |
197 | ||
198 | if (!pgen_primep(g->mm.m, &rand_global)) return ("p is not prime"); | |
199 | if (!pgen_primep(g->q, &rand_global)) return ("q is not prime"); | |
200 | mp_div(0, &t, g->mm.m, g->q); | |
201 | if (!MP_EQ(t, MP_ONE)) return ("q is not a subgroup order"); | |
202 | t = mpmont_expr(&g->mm, t, g->G, g->q); | |
203 | if (!MP_EQ(t, g->mm.r)) return ("g not in the subgroup"); | |
204 | return (0); | |
205 | } | |
206 | ||
207 | static void intdh_grpinfo(const dhgrp *gg, admin *adm) | |
208 | { | |
209 | const intdh_grp *g = (const intdh_grp *)gg; | |
210 | a_info(adm, | |
211 | "kx-group=prime", | |
212 | "kx-group-order-bits=%lu", (unsigned long)mp_bits(g->q), | |
213 | "kx-group-elt-bits=%lu", (unsigned long)mp_bits(g->mm.m), | |
214 | A_END); | |
215 | } | |
216 | ||
217 | #ifndef NTRACE | |
218 | static void intdh_tracegrp(const dhgrp *gg) | |
219 | { | |
220 | const intdh_grp *g = (const intdh_grp *)gg; | |
221 | mp *t = MP_NEW; | |
222 | trace(T_CRYPTO, "crypto: group type `dh'"); | |
223 | trace(T_CRYPTO, "crypto: p = %s", mpstr(g->mm.m, 10)); | |
224 | trace(T_CRYPTO, "crypto: q = %s", mpstr(g->q, 10)); | |
225 | t = mpmont_reduce(&g->mm, t, g->G); | |
226 | trace(T_CRYPTO, "crypto: g = %s", mpstr(t, 10)); | |
227 | MP_DROP(t); | |
228 | } | |
229 | #endif | |
230 | ||
231 | static int intdh_samegrpp(const dhgrp *gg, const dhgrp *hh) | |
232 | { | |
233 | const intdh_grp *g = (const intdh_grp *)gg, *h = (const intdh_grp *)hh; | |
07bdda1f MW |
234 | return (MP_EQ(g->mm.m, h->mm.m) && |
235 | MP_EQ(g->q, h->q) && MP_EQ(g->G, h->G) && | |
236 | g->ser == h->ser); | |
5b9f3d37 MW |
237 | } |
238 | ||
239 | static void intdh_freegrp(dhgrp *gg) | |
240 | { | |
241 | intdh_grp *g = (intdh_grp *)gg; | |
242 | mpmont_destroy(&g->mm); MP_DROP(g->q); MP_DROP(g->G); | |
243 | DESTROY(g); | |
244 | } | |
245 | ||
246 | static dhsc *intdh_ldsc(const dhgrp *gg, const void *p, size_t sz) | |
247 | { const intdh_grp *g = (const intdh_grp *)gg; | |
248 | intdh_sc *x = CREATE(intdh_sc); | |
249 | mp *t = mp_loadb(MP_NEW, p, sz); | |
250 | mp_div(0, &t, t, g->q); x->x = t; | |
251 | return ((dhsc *)x); | |
252 | } | |
253 | ||
254 | static int intdh_stsc(const dhgrp *gg, void *p, size_t sz, const dhsc *xx) | |
255 | { | |
256 | const intdh_sc *x = (const intdh_sc *)xx; | |
257 | mp_storeb(x->x, p, sz); | |
258 | return (0); | |
259 | } | |
260 | ||
261 | static dhsc *intdh_randsc(const dhgrp *gg) | |
262 | { | |
263 | const intdh_grp *g = (const intdh_grp *)gg; | |
264 | intdh_sc *x = CREATE(intdh_sc); | |
265 | x->x = mprand_range(MP_NEW, g->q, &rand_global, 0); | |
266 | return ((dhsc *)x); | |
267 | } | |
268 | ||
269 | #ifndef NTRACE | |
270 | static const char *intdh_scstr(const dhgrp *gg, const dhsc *xx) | |
271 | { const intdh_sc *x = (const intdh_sc *)xx; return (mpstr(x->x, 10)); } | |
272 | #endif | |
273 | ||
274 | static void intdh_freesc(const dhgrp *gg, dhsc *xx) | |
275 | { | |
276 | intdh_sc *x = (intdh_sc *)xx; | |
277 | MP_DROP(x->x); DESTROY(x); | |
278 | } | |
279 | ||
280 | static dhge *intdh_ldge(const dhgrp *gg, buf *b, int fmt) | |
281 | { | |
282 | const intdh_grp *g = (const intdh_grp *)gg; | |
283 | intdh_ge *Y; | |
284 | mp *t; | |
285 | const octet *p; | |
286 | ||
287 | switch (fmt) { | |
07bdda1f MW |
288 | case DHFMT_HASH: if (g->ser == DHSER_CONSTLEN) goto std; |
289 | case DHFMT_VAR: | |
5b9f3d37 MW |
290 | if ((t = buf_getmp(b)) == 0) return (0); |
291 | break; | |
07bdda1f | 292 | case DHFMT_STD: std: |
5b9f3d37 MW |
293 | if ((p = buf_get(b, g->gesz)) == 0) return (0); |
294 | t = mp_loadb(MP_NEW, p, g->gesz); | |
295 | break; | |
296 | default: | |
297 | abort(); | |
298 | } | |
299 | Y = CREATE(intdh_ge); | |
300 | mp_div(0, &t, t, g->mm.m); | |
301 | Y->X = mpmont_mul(&g->mm, t, t, g->mm.r2); | |
302 | return ((dhge *)Y); | |
303 | } | |
304 | ||
305 | static int intdh_stge(const dhgrp *gg, buf *b, const dhge *YY, int fmt) | |
306 | { | |
307 | const intdh_grp *g = (const intdh_grp *)gg; | |
308 | const intdh_ge *Y = (const intdh_ge *)YY; | |
309 | octet *p; | |
310 | mp *t; | |
311 | int rc; | |
312 | ||
313 | t = mpmont_reduce(&g->mm, MP_NEW, Y->X); | |
314 | switch (fmt) { | |
07bdda1f MW |
315 | case DHFMT_HASH: if (g->ser == DHSER_CONSTLEN) goto std; |
316 | case DHFMT_VAR: | |
5b9f3d37 MW |
317 | rc = buf_putmp(b, t); |
318 | break; | |
07bdda1f | 319 | case DHFMT_STD: std: |
5b9f3d37 MW |
320 | if ((p = buf_get(b, g->gesz)) == 0) |
321 | rc = -1; | |
322 | else { | |
323 | mp_storeb(t, p, g->gesz); | |
324 | rc = 0; | |
325 | } | |
326 | break; | |
327 | default: | |
328 | abort(); | |
329 | } | |
330 | MP_DROP(t); | |
331 | return (rc); | |
332 | } | |
333 | ||
334 | static int intdh_checkge(const dhgrp *gg, const dhge *YY) | |
335 | { | |
336 | const intdh_grp *g = (const intdh_grp *)gg; | |
337 | const intdh_ge *Y = (const intdh_ge *)YY; | |
338 | mp *T; | |
339 | int rc = 0; | |
340 | ||
341 | if (MP_EQ(Y->X, g->mm.r)) rc = -1; | |
342 | T = mpmont_expr(&g->mm, MP_NEW, Y->X, g->q); | |
343 | if (!MP_EQ(T, g->mm.r)) rc = -1; | |
344 | MP_DROP(T); | |
345 | return (rc); | |
346 | } | |
347 | ||
348 | static int intdh_eq(const dhgrp *gg, const dhge *YY, const dhge *ZZ) | |
349 | { | |
350 | const intdh_ge *Y = (const intdh_ge *)YY, *Z = (const intdh_ge *)ZZ; | |
351 | return (MP_EQ(Y->X, Z->X)); | |
352 | } | |
353 | ||
354 | static dhge *intdh_mul(const dhgrp *gg, const dhsc *xx, const dhge *YY) | |
355 | { | |
356 | const intdh_grp *g = (const intdh_grp *)gg; | |
357 | const intdh_sc *x = (const intdh_sc *)xx; | |
358 | const intdh_ge *Y = (const intdh_ge *)YY; | |
359 | intdh_ge *Z = CREATE(intdh_ge); | |
360 | ||
361 | Z->X = mpmont_expr(&g->mm, MP_NEW, Y ? Y->X : g->G, x->x); | |
362 | return ((dhge *)Z); | |
363 | } | |
364 | ||
365 | #ifndef NTRACE | |
366 | static const char *intdh_gestr(const dhgrp *gg, const dhge *YY) | |
367 | { | |
368 | const intdh_grp *g = (const intdh_grp *)gg; | |
369 | const intdh_ge *Y = (const intdh_ge *)YY; | |
370 | mp *t = mpmont_reduce(&g->mm, MP_NEW, Y->X); | |
371 | const char *p = mpstr(t, 10); | |
372 | MP_DROP(t); | |
373 | return (p); | |
374 | } | |
375 | #endif | |
376 | ||
377 | static void intdh_freege(const dhgrp *gg, dhge *YY) | |
378 | { intdh_ge *Y = (intdh_ge *)YY; MP_DROP(Y->X); DESTROY(Y); } | |
379 | ||
380 | /*----- Elliptic curve groups ---------------------------------------------*/ | |
381 | ||
382 | typedef struct ecdh_grp { | |
383 | dhgrp _g; | |
384 | ec_info ei; | |
385 | ec P; | |
07bdda1f | 386 | int ser; |
5b9f3d37 MW |
387 | } ecdh_grp; |
388 | ||
389 | typedef struct ecdh_sc { mp *x; } ecdh_sc; | |
390 | typedef struct ecdh_ge { ec Q; } ecdh_ge; | |
391 | ||
07bdda1f | 392 | static dhgrp *ecdh_mkgroup(key_file *kf, key *k, const char *cstr, dstr *e) |
5b9f3d37 MW |
393 | { |
394 | ecdh_grp *g; | |
395 | ec_info ei; | |
07bdda1f | 396 | int ser; |
5b9f3d37 MW |
397 | const char *err; |
398 | ||
07bdda1f | 399 | if ((ser = get_serialization(kf, k, e)) < 0) return (0); |
5b9f3d37 MW |
400 | if ((err = ec_getinfo(&ei, cstr)) != 0) { |
401 | a_format(e, "decode-failed", "%s", err, A_END); | |
402 | return (0); | |
403 | } | |
404 | g = CREATE(ecdh_grp); | |
07bdda1f | 405 | g->ser = ser; |
5b9f3d37 MW |
406 | g->ei = ei; |
407 | EC_CREATE(&g->P); EC_IN(g->ei.c, &g->P, &g->ei.g); | |
408 | g->_g.scsz = mp_octets(g->ei.r); | |
409 | return (&g->_g); | |
410 | } | |
411 | ||
412 | static dhsc *ecdh_mptosc(const dhgrp *gg, mp *z) | |
413 | { | |
414 | const ecdh_grp *g = (const ecdh_grp *)gg; | |
415 | ecdh_sc *x = CREATE(ecdh_sc); | |
416 | x->x = MP_NEW; mp_div(0, &x->x, z, g->ei.r); | |
417 | return ((dhsc *)x); | |
418 | } | |
419 | ||
420 | static dhge *ecdh_ectoge(const dhgrp *gg, ec *Q) | |
421 | { | |
422 | const ecdh_grp *g = (const ecdh_grp *)gg; | |
423 | ecdh_ge *Y = CREATE(ecdh_ge); EC_CREATE(&Y->Q); | |
424 | EC_IN(g->ei.c, &Y->Q, Q); | |
425 | if (EC_CHECK(g->ei.c, &Y->Q)) | |
426 | { EC_DESTROY(&Y->Q); DESTROY(Y); return (0); } | |
427 | return ((dhge *)Y); | |
428 | } | |
429 | ||
430 | KLOAD(ecdh, ec, EC, | |
07bdda1f | 431 | { if ((kd->grp = ecdh_mkgroup(kf, k, p.cstr, e)) == 0) goto fail; }, |
5b9f3d37 MW |
432 | { kd->k = ecdh_mptosc(kd->grp, p.x); }, |
433 | { if ((kd->K = ecdh_ectoge(kd->grp, &p.p)) == 0) { | |
434 | a_format(e, "bad-public-vector", A_END); | |
435 | goto fail; | |
436 | } | |
437 | }) | |
438 | ||
439 | static const char *ecdh_checkgrp(const dhgrp *gg) | |
440 | { | |
441 | const ecdh_grp *g = (const ecdh_grp *)gg; | |
442 | return (ec_checkinfo(&g->ei, &rand_global)); | |
443 | } | |
444 | ||
445 | static void ecdh_grpinfo(const dhgrp *gg, admin *adm) | |
446 | { | |
447 | const ecdh_grp *g = (const ecdh_grp *)gg; | |
448 | a_info(adm, | |
449 | "kx-group=ec", | |
450 | "kx-group-order-bits=%lu", (unsigned long)mp_bits(g->ei.r), | |
451 | "kx-group-elt-bits=%lu", (unsigned long)2*g->ei.c->f->nbits, | |
452 | A_END); | |
453 | } | |
454 | ||
455 | #ifndef NTRACE | |
456 | static void addfestr(field *f, mp *x, mptext_stringctx *sc) | |
457 | { addmpstr(x, F_TYPE(f) == FTY_PRIME ? 10 : 16, sc); } | |
458 | ||
459 | static void addintfestr(field *f, mp *x, mptext_stringctx *sc) | |
460 | { mp *t = F_OUT(f, MP_NEW, x); addfestr(f, x, sc); MP_DROP(t); } | |
461 | ||
462 | static const char *intfestr(field *f, mp *x) | |
463 | { | |
464 | mptext_stringctx sc; | |
465 | setupstr(&sc); | |
466 | addintfestr(f, x, &sc); | |
467 | return (donestr(&sc)); | |
468 | } | |
469 | ||
470 | static void ecdh_tracegrp(const dhgrp *gg) | |
471 | { | |
472 | const ecdh_grp *g = (const ecdh_grp *)gg; | |
473 | const ec_curve *c = g->ei.c; | |
474 | field *f = c->f; | |
475 | ||
476 | trace(T_CRYPTO, "crypto: group type `ec'"); | |
477 | switch (F_TYPE(f)) { | |
478 | case FTY_PRIME: | |
479 | trace(T_CRYPTO, "crypto: prime field `%s'", F_NAME(f)); | |
480 | trace(T_CRYPTO, "crypto: p = %s", mpstr(f->q, 10)); | |
481 | break; | |
482 | case FTY_BINARY: | |
483 | trace(T_CRYPTO, "crypto: binary field `%s'", F_NAME(f)); | |
484 | trace(T_CRYPTO, "crypto: degree = %lu", f->nbits - 1); | |
485 | break; | |
486 | default: | |
487 | trace(T_CRYPTO, "crypto: unknown field type! `%s'", F_NAME(f)); | |
488 | break; | |
489 | } | |
490 | trace(T_CRYPTO, "crypto: curve type `%s'", EC_NAME(c)); | |
491 | trace(T_CRYPTO, "crypto: curve a = %s", intfestr(f, c->a)); | |
492 | trace(T_CRYPTO, "crypto: curve b = %s", intfestr(f, c->b)); | |
493 | trace(T_CRYPTO, "crypto: n = %s", mpstr(g->ei.r, 10)); | |
494 | trace(T_CRYPTO, "crypto: h = %s", mpstr(g->ei.h, 10)); | |
495 | } | |
496 | #endif | |
497 | ||
498 | static int ecdh_samegrpp(const dhgrp *gg, const dhgrp *hh) | |
499 | { | |
500 | const ecdh_grp *g = (const ecdh_grp *)gg, *h = (const ecdh_grp *)hh; | |
07bdda1f MW |
501 | return (ec_sameinfop(&g->ei, &h->ei) && |
502 | g->ser == h->ser); | |
5b9f3d37 MW |
503 | } |
504 | ||
505 | static void ecdh_freegrp(dhgrp *gg) | |
506 | { | |
507 | ecdh_grp *g = (ecdh_grp *)gg; | |
508 | EC_DESTROY(&g->P); ec_freeinfo(&g->ei); | |
509 | DESTROY(g); | |
510 | } | |
511 | ||
512 | static dhsc *ecdh_ldsc(const dhgrp *gg, const void *p, size_t sz) | |
513 | { | |
514 | const ecdh_grp *g = (const ecdh_grp *)gg; | |
515 | ecdh_sc *x = CREATE(ecdh_sc); | |
516 | mp *t = mp_loadb(MP_NEW, p, sz); | |
517 | mp_div(0, &t, t, g->ei.r); x->x = t; | |
518 | return ((dhsc *)x); | |
519 | } | |
520 | ||
521 | static int ecdh_stsc(const dhgrp *gg, void *p, size_t sz, const dhsc *xx) | |
522 | { | |
523 | const ecdh_sc *x = (const ecdh_sc *)xx; | |
524 | mp_storeb(x->x, p, sz); | |
525 | return (0); | |
526 | } | |
527 | ||
528 | static dhsc *ecdh_randsc(const dhgrp *gg) | |
529 | { | |
530 | const ecdh_grp *g = (const ecdh_grp *)gg; | |
531 | ecdh_sc *x = CREATE(ecdh_sc); | |
532 | x->x = mprand_range(MP_NEW, g->ei.r, &rand_global, 0); | |
533 | return ((dhsc *)x); | |
534 | } | |
535 | ||
536 | #ifndef NTRACE | |
537 | static const char *ecdh_scstr(const dhgrp *gg, const dhsc *xx) | |
538 | { | |
539 | const ecdh_sc *x = (const ecdh_sc *)xx; | |
540 | return (mpstr(x->x, 10)); | |
541 | } | |
542 | #endif | |
543 | ||
544 | static void ecdh_freesc(const dhgrp *gg, dhsc *xx) | |
545 | { ecdh_sc *x = (ecdh_sc *)xx; MP_DROP(x->x); DESTROY(x); } | |
546 | ||
547 | static dhge *ecdh_ldge(const dhgrp *gg, buf *b, int fmt) | |
548 | { | |
549 | const ecdh_grp *g = (const ecdh_grp *)gg; | |
550 | ecdh_ge *Y; | |
551 | ec T = EC_INIT; | |
552 | ||
553 | switch (fmt) { | |
07bdda1f MW |
554 | case DHFMT_HASH: if (g->ser == DHSER_CONSTLEN) goto std; |
555 | case DHFMT_VAR: if (buf_getec(b, &T)) return (0); break; | |
556 | case DHFMT_STD: std: if (ec_getraw(g->ei.c, b, &T)) return (0); break; | |
5b9f3d37 MW |
557 | default: |
558 | abort(); | |
559 | } | |
560 | EC_IN(g->ei.c, &T, &T); | |
561 | Y = CREATE(ecdh_ge); Y->Q = T; | |
562 | return ((dhge *)Y); | |
563 | } | |
564 | ||
565 | static int ecdh_stge(const dhgrp *gg, buf *b, const dhge *YY, int fmt) | |
566 | { | |
567 | const ecdh_grp *g = (const ecdh_grp *)gg; | |
568 | const ecdh_ge *Y = (const ecdh_ge *)YY; | |
569 | ec T = EC_INIT; | |
570 | int rc; | |
571 | ||
572 | EC_OUT(g->ei.c, &T, &Y->Q); | |
573 | switch (fmt) { | |
07bdda1f MW |
574 | case DHFMT_HASH: if (g->ser == DHSER_CONSTLEN) goto std; |
575 | case DHFMT_VAR: rc = buf_putec(b, &T); break; | |
576 | case DHFMT_STD: std: rc = ec_putraw(g->ei.c, b, &T); break; | |
5b9f3d37 MW |
577 | default: abort(); |
578 | } | |
579 | EC_DESTROY(&T); | |
580 | return (rc); | |
581 | } | |
582 | ||
583 | static int ecdh_checkge(const dhgrp *gg, const dhge *YY) | |
584 | { | |
585 | const ecdh_grp *g = (const ecdh_grp *)gg; | |
586 | const ecdh_ge *Y = (const ecdh_ge *)YY; | |
587 | ec T = EC_INIT; | |
588 | int rc = 0; | |
589 | ||
590 | if (EC_ATINF(&Y->Q)) rc = -1; | |
591 | ec_imul(g->ei.c, &T, &Y->Q, g->ei.r); | |
592 | if (!EC_ATINF(&T)) rc = -1; | |
593 | EC_DESTROY(&T); | |
594 | return (rc); | |
595 | } | |
596 | ||
597 | static int ecdh_eq(const dhgrp *gg, const dhge *YY, const dhge *ZZ) | |
598 | { | |
599 | const ecdh_grp *g = (const ecdh_grp *)gg; | |
600 | const ecdh_ge *Y = (const ecdh_ge *)YY, *Z = (const ecdh_ge *)ZZ; | |
601 | ec T = EC_INIT, U = EC_INIT; int rc; | |
602 | EC_FIX(g->ei.c, &T, &Y->Q); EC_FIX(g->ei.c, &U, &Z->Q); | |
603 | rc = EC_EQ(&T, &U); | |
604 | EC_DESTROY(&T); EC_DESTROY(&U); | |
605 | return (rc); | |
606 | } | |
607 | ||
608 | static dhge *ecdh_mul(const dhgrp *gg, const dhsc *xx, const dhge *YY) | |
609 | { | |
610 | const ecdh_grp *g = (const ecdh_grp *)gg; | |
611 | const ecdh_sc *x = (const ecdh_sc *)xx; | |
612 | const ecdh_ge *Y = (const ecdh_ge *)YY; | |
613 | ecdh_ge *Z = CREATE(ecdh_ge); EC_CREATE(&Z->Q); | |
614 | ||
615 | ec_imul(g->ei.c, &Z->Q, Y ? &Y->Q : &g->P, x->x); | |
616 | return ((dhge *)Z); | |
617 | } | |
618 | ||
619 | #ifndef NTRACE | |
620 | static const char *ecdh_gestr(const dhgrp *gg, const dhge *YY) | |
621 | { | |
622 | const ecdh_grp *g = (const ecdh_grp *)gg; | |
623 | const ecdh_ge *Y = (const ecdh_ge *)YY; | |
624 | ec T = EC_INIT; | |
625 | field *f = g->ei.c->f; | |
626 | mptext_stringctx sc; | |
627 | ||
628 | if (EC_ATINF(&Y->Q)) return ("inf"); | |
629 | setupstr(&sc); | |
630 | EC_OUT(g->ei.c, &T, &Y->Q); | |
631 | addfestr(f, T.x, &sc); | |
632 | addlitstr(", ", &sc); | |
633 | addfestr(f, T.y, &sc); | |
634 | EC_DESTROY(&T); | |
635 | return (donestr(&sc)); | |
636 | } | |
637 | #endif | |
638 | ||
639 | static void ecdh_freege(const dhgrp *gg, dhge *YY) | |
640 | { ecdh_ge *Y = (ecdh_ge *)YY; EC_DESTROY(&Y->Q); DESTROY(Y); } | |
641 | ||
26936c83 MW |
642 | /*----- The X25519 and similar groups -------------------------------------*/ |
643 | ||
644 | #define XDHS(_) \ | |
645 | _(x25519, X25519, "curve25519", 252, 255) \ | |
646 | _(x448, X448, "ed448-goldilocks", 446, 448) | |
647 | ||
648 | #ifdef NTRACE | |
649 | # define XDHTRACE(xdh, XDH, gname) | |
650 | #else | |
651 | ||
652 | static const char *binstr(const octet *p, size_t sz) | |
653 | { | |
654 | char *q; | |
655 | ||
656 | for (q = (char *)buf_u; sz--; p++, q += 2) sprintf(q, "%02x", *p); | |
657 | return ((const char *)buf_u); | |
658 | } | |
659 | ||
660 | # define XDHTRACE(xdh, XDH, gname) \ | |
661 | static void xdh##_tracegrp(const dhgrp *g) \ | |
662 | { trace(T_CRYPTO, "crypto: group type `" gname "'"); } \ | |
663 | \ | |
664 | static const char *xdh##_scstr(const dhgrp *g, const dhsc *xx) \ | |
665 | { \ | |
666 | const xdh##_sc *x = (const xdh##_sc *)xx; \ | |
667 | return (binstr(x->x, XDH##_KEYSZ)); \ | |
668 | } \ | |
669 | \ | |
670 | static const char *xdh##_gestr(const dhgrp *g, const dhge *YY) \ | |
671 | { \ | |
672 | const xdh##_ge *Y = (const xdh##_ge *)YY; \ | |
673 | return (binstr(Y->X, XDH##_PUBSZ)); \ | |
674 | } | |
675 | #endif | |
676 | ||
677 | #define XDHDEF(xdh, XDH, gname, groupbits, fieldbits) \ | |
678 | \ | |
679 | typedef struct xdh##_sc { octet x[XDH##_KEYSZ]; } xdh##_sc; \ | |
680 | typedef struct xdh##_ge { octet X[XDH##_PUBSZ]; } xdh##_ge; \ | |
681 | \ | |
682 | XDHTRACE(xdh, XDH, gname) \ | |
683 | \ | |
684 | static dhsc *xdh##_bintosc(const key_bin *b) \ | |
685 | { \ | |
686 | xdh##_sc *x; \ | |
687 | \ | |
688 | if (b->sz != XDH##_KEYSZ) return (0); \ | |
689 | x = CREATE(xdh##_sc); \ | |
690 | memcpy(x->x, b->k, XDH##_KEYSZ); \ | |
691 | return ((dhsc *)x); \ | |
692 | } \ | |
693 | \ | |
694 | static dhge *xdh##_bintoge(const key_bin *b) \ | |
695 | { \ | |
696 | xdh##_ge *Y; \ | |
697 | \ | |
698 | if (b->sz != XDH##_PUBSZ) return (0); \ | |
699 | Y = CREATE(xdh##_ge); \ | |
700 | memcpy(Y->X, b->k, XDH##_PUBSZ); \ | |
701 | return ((dhge *)Y); \ | |
702 | } \ | |
703 | \ | |
704 | KLOAD(xdh, xdh, XDH, \ | |
705 | { kd->grp = CREATE(dhgrp); kd->grp->scsz = 32; }, \ | |
706 | { if ((kd->k = xdh##_bintosc(&p.priv)) == 0) { \ | |
707 | a_format(e, "bad-private-key", A_END); \ | |
708 | goto fail; \ | |
709 | } \ | |
710 | }, \ | |
711 | { if ((kd->K = xdh##_bintoge(&p.pub)) == 0) { \ | |
712 | a_format(e, "bad-public-vector", A_END); \ | |
713 | goto fail; \ | |
714 | } \ | |
715 | }) \ | |
716 | \ | |
717 | static const char *xdh##_checkgrp(const dhgrp *g) \ | |
718 | { return (0); } \ | |
719 | \ | |
720 | static void xdh##_grpinfo(const dhgrp *g, admin *adm) \ | |
721 | { \ | |
722 | a_info(adm, \ | |
723 | "kx-group=" gname, \ | |
724 | "kx-group-order-bits=%d", (groupbits), \ | |
725 | "kx-group-elt-bits=%d", (fieldbits), \ | |
726 | A_END); \ | |
727 | } \ | |
728 | \ | |
729 | static int xdh##_samegrpp(const dhgrp *g, const dhgrp *hh) \ | |
730 | { return (1); } \ | |
731 | \ | |
732 | static void xdh##_freegrp(dhgrp *g) \ | |
733 | { DESTROY(g); } \ | |
734 | \ | |
735 | static dhsc *xdh##_ldsc(const dhgrp *g, const void *p, size_t sz) \ | |
736 | { \ | |
737 | xdh##_sc *x; \ | |
738 | if (sz != XDH##_KEYSZ) return (0); \ | |
739 | x = CREATE(xdh##_sc); \ | |
740 | memcpy(x->x, p, XDH##_KEYSZ); \ | |
741 | return ((dhsc *)x); \ | |
742 | } \ | |
743 | \ | |
744 | static int xdh##_stsc(const dhgrp *g, void *p, size_t sz, \ | |
745 | const dhsc *xx) \ | |
746 | { \ | |
747 | const xdh##_sc *x = (const xdh##_sc *)xx; \ | |
748 | if (sz != XDH##_KEYSZ) return (-1); \ | |
749 | memcpy(p, x->x, XDH##_KEYSZ); \ | |
750 | return (0); \ | |
751 | } \ | |
752 | \ | |
753 | static dhsc *xdh##_randsc(const dhgrp *g) \ | |
754 | { \ | |
755 | xdh##_sc *x = CREATE(xdh##_sc); \ | |
756 | rand_get(RAND_GLOBAL, x->x, XDH##_KEYSZ); \ | |
757 | return ((dhsc *)x); \ | |
758 | } \ | |
759 | \ | |
760 | static void xdh##_freesc(const dhgrp *g, dhsc *xx) \ | |
761 | { xdh##_sc *x = (xdh##_sc *)xx; DESTROY(x); } \ | |
762 | \ | |
763 | static dhge *xdh##_ldge(const dhgrp *g, buf *b, int fmt) \ | |
764 | { \ | |
765 | xdh##_ge *Y; \ | |
766 | const octet *p; \ | |
767 | \ | |
768 | if ((p = buf_get(b, XDH##_PUBSZ)) == 0) return (0); \ | |
769 | Y = CREATE(xdh##_ge); memcpy(Y->X, p, XDH##_PUBSZ); \ | |
770 | return ((dhge *)Y); \ | |
771 | } \ | |
772 | \ | |
773 | static int xdh##_stge(const dhgrp *g, buf *b, \ | |
774 | const dhge *YY, int fmt) \ | |
775 | { \ | |
776 | const xdh##_ge *Y = (const xdh##_ge *)YY; \ | |
777 | return (buf_put(b, Y->X, XDH##_PUBSZ)); \ | |
778 | } \ | |
779 | \ | |
780 | static int xdh##_checkge(const dhgrp *g, const dhge *YY) \ | |
781 | { return (0); } \ | |
782 | \ | |
783 | static int xdh##_eq(const dhgrp *g, const dhge *YY, const dhge *ZZ) \ | |
784 | { \ | |
785 | const xdh##_ge \ | |
786 | *Y = (const xdh##_ge *)YY, *Z = (const xdh##_ge *)ZZ; \ | |
787 | return (ct_memeq(Y->X, Z->X, XDH##_PUBSZ)); \ | |
788 | } \ | |
789 | \ | |
790 | static dhge *xdh##_mul(const dhgrp *g, \ | |
791 | const dhsc *xx, const dhge *YY) \ | |
792 | { \ | |
793 | const xdh##_sc *x = (const xdh##_sc *)xx; \ | |
794 | const xdh##_ge *Y = (const xdh##_ge *)YY; \ | |
795 | xdh##_ge *Z = CREATE(xdh##_ge); \ | |
796 | \ | |
797 | xdh(Z->X, x->x, Y ? Y->X : xdh##_base); \ | |
798 | return ((dhge *)Z); \ | |
799 | } \ | |
800 | \ | |
801 | static void xdh##_freege(const dhgrp *g, dhge *YY) \ | |
802 | { xdh##_ge *Y = (xdh##_ge *)YY; DESTROY(Y); } | |
803 | ||
804 | XDHS(XDHDEF) | |
805 | ||
806 | #undef XDHDEF | |
807 | ||
5b9f3d37 MW |
808 | /*----- Diffie--Hellman group table ---------------------------------------*/ |
809 | ||
810 | const dhops dhtab[] = { | |
811 | ||
812 | #define COMMA , | |
813 | ||
814 | #define DH(name, pre) \ | |
815 | { name, pre##_ldpriv, pre##_ldpub, pre##_checkgrp, \ | |
816 | pre##_grpinfo, T( pre##_tracegrp COMMA ) pre##_samegrpp, \ | |
817 | pre##_freegrp, \ | |
818 | pre##_ldsc, pre##_stsc, pre##_randsc, T( pre##_scstr COMMA ) \ | |
819 | pre##_freesc, \ | |
820 | pre##_ldge, pre##_stge, pre##_checkge, pre##_eq, pre##_mul, \ | |
821 | T( pre##_gestr COMMA ) pre##_freege }, \ | |
822 | ||
823 | DH("dh", intdh) | |
824 | DH("ec", ecdh) | |
825 | ||
26936c83 MW |
826 | #define XDHDH(xdh, XDH, gname, groupbits, fieldbits) DH(#xdh, xdh) |
827 | XDHS(XDHDH) | |
828 | #undef XDHDH | |
829 | ||
5b9f3d37 MW |
830 | #undef DH |
831 | ||
832 | { 0 } | |
833 | }; | |
834 | ||
835 | /*----- That's all, folks -------------------------------------------------*/ |