summaryrefslogtreecommitdiff
path: root/src/lib/libcrypto/bn/bn_mont.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/lib/libcrypto/bn/bn_mont.c')
-rw-r--r--src/lib/libcrypto/bn/bn_mont.c538
1 files changed, 0 insertions, 538 deletions
diff --git a/src/lib/libcrypto/bn/bn_mont.c b/src/lib/libcrypto/bn/bn_mont.c
deleted file mode 100644
index 3eb9913a9e..0000000000
--- a/src/lib/libcrypto/bn/bn_mont.c
+++ /dev/null
@@ -1,538 +0,0 @@
1/* $OpenBSD: bn_mont.c,v 1.24 2015/02/09 15:49:22 jsing Exp $ */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 * must display the following acknowledgement:
33 * "This product includes cryptographic software written by
34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58/* ====================================================================
59 * Copyright (c) 1998-2006 The OpenSSL Project. All rights reserved.
60 *
61 * Redistribution and use in source and binary forms, with or without
62 * modification, are permitted provided that the following conditions
63 * are met:
64 *
65 * 1. Redistributions of source code must retain the above copyright
66 * notice, this list of conditions and the following disclaimer.
67 *
68 * 2. Redistributions in binary form must reproduce the above copyright
69 * notice, this list of conditions and the following disclaimer in
70 * the documentation and/or other materials provided with the
71 * distribution.
72 *
73 * 3. All advertising materials mentioning features or use of this
74 * software must display the following acknowledgment:
75 * "This product includes software developed by the OpenSSL Project
76 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
77 *
78 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
79 * endorse or promote products derived from this software without
80 * prior written permission. For written permission, please contact
81 * openssl-core@openssl.org.
82 *
83 * 5. Products derived from this software may not be called "OpenSSL"
84 * nor may "OpenSSL" appear in their names without prior written
85 * permission of the OpenSSL Project.
86 *
87 * 6. Redistributions of any form whatsoever must retain the following
88 * acknowledgment:
89 * "This product includes software developed by the OpenSSL Project
90 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
91 *
92 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
93 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
94 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
95 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
96 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
97 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
98 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
99 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
100 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
101 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
102 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
103 * OF THE POSSIBILITY OF SUCH DAMAGE.
104 * ====================================================================
105 *
106 * This product includes cryptographic software written by Eric Young
107 * (eay@cryptsoft.com). This product includes software written by Tim
108 * Hudson (tjh@cryptsoft.com).
109 *
110 */
111
112/*
113 * Details about Montgomery multiplication algorithms can be found at
114 * http://security.ece.orst.edu/publications.html, e.g.
115 * http://security.ece.orst.edu/koc/papers/j37acmon.pdf and
116 * sections 3.8 and 4.2 in http://security.ece.orst.edu/koc/papers/r01rsasw.pdf
117 */
118
119#include <stdio.h>
120#include <stdint.h>
121
122#include "bn_lcl.h"
123
124#define MONT_WORD /* use the faster word-based algorithm */
125
126#ifdef MONT_WORD
127static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont);
128#endif
129
130int
131BN_mod_mul_montgomery(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
132 BN_MONT_CTX *mont, BN_CTX *ctx)
133{
134 BIGNUM *tmp;
135 int ret = 0;
136#if defined(OPENSSL_BN_ASM_MONT) && defined(MONT_WORD)
137 int num = mont->N.top;
138
139 if (num > 1 && a->top == num && b->top == num) {
140 if (bn_wexpand(r, num) == NULL)
141 return (0);
142 if (bn_mul_mont(r->d, a->d, b->d, mont->N.d, mont->n0, num)) {
143 r->neg = a->neg^b->neg;
144 r->top = num;
145 bn_correct_top(r);
146 return (1);
147 }
148 }
149#endif
150
151 BN_CTX_start(ctx);
152 if ((tmp = BN_CTX_get(ctx)) == NULL)
153 goto err;
154
155 bn_check_top(tmp);
156 if (a == b) {
157 if (!BN_sqr(tmp, a, ctx))
158 goto err;
159 } else {
160 if (!BN_mul(tmp, a,b, ctx))
161 goto err;
162 }
163 /* reduce from aRR to aR */
164#ifdef MONT_WORD
165 if (!BN_from_montgomery_word(r, tmp, mont))
166 goto err;
167#else
168 if (!BN_from_montgomery(r, tmp, mont, ctx))
169 goto err;
170#endif
171 bn_check_top(r);
172 ret = 1;
173err:
174 BN_CTX_end(ctx);
175 return (ret);
176}
177
178#ifdef MONT_WORD
179static int
180BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont)
181{
182 BIGNUM *n;
183 BN_ULONG *ap, *np, *rp, n0, v, carry;
184 int nl, max, i;
185
186 n = &(mont->N);
187 nl = n->top;
188 if (nl == 0) {
189 ret->top = 0;
190 return (1);
191 }
192
193 max = (2 * nl); /* carry is stored separately */
194 if (bn_wexpand(r, max) == NULL)
195 return (0);
196
197 r->neg ^= n->neg;
198 np = n->d;
199 rp = r->d;
200
201 /* clear the top words of T */
202#if 1
203 for (i=r->top; i<max; i++) /* memset? XXX */
204 rp[i] = 0;
205#else
206 memset(&(rp[r->top]), 0, (max - r->top) * sizeof(BN_ULONG));
207#endif
208
209 r->top = max;
210 n0 = mont->n0[0];
211
212#ifdef BN_COUNT
213 fprintf(stderr, "word BN_from_montgomery_word %d * %d\n", nl, nl);
214#endif
215 for (carry = 0, i = 0; i < nl; i++, rp++) {
216 v = bn_mul_add_words(rp, np, nl, (rp[0] * n0) & BN_MASK2);
217 v = (v + carry + rp[nl]) & BN_MASK2;
218 carry |= (v != rp[nl]);
219 carry &= (v <= rp[nl]);
220 rp[nl] = v;
221 }
222
223 if (bn_wexpand(ret, nl) == NULL)
224 return (0);
225 ret->top = nl;
226 ret->neg = r->neg;
227
228 rp = ret->d;
229 ap = &(r->d[nl]);
230
231#define BRANCH_FREE 1
232#if BRANCH_FREE
233 {
234 BN_ULONG *nrp;
235 size_t m;
236
237 v = bn_sub_words(rp, ap, np, nl) - carry;
238 /* if subtraction result is real, then
239 * trick unconditional memcpy below to perform in-place
240 * "refresh" instead of actual copy. */
241 m = (0 - (size_t)v);
242 nrp = (BN_ULONG *)(((uintptr_t)rp & ~m)|((uintptr_t)ap & m));
243
244 for (i = 0, nl -= 4; i < nl; i += 4) {
245 BN_ULONG t1, t2, t3, t4;
246
247 t1 = nrp[i + 0];
248 t2 = nrp[i + 1];
249 t3 = nrp[i + 2];
250 ap[i + 0] = 0;
251 t4 = nrp[i + 3];
252 ap[i + 1] = 0;
253 rp[i + 0] = t1;
254 ap[i + 2] = 0;
255 rp[i + 1] = t2;
256 ap[i + 3] = 0;
257 rp[i + 2] = t3;
258 rp[i + 3] = t4;
259 }
260 for (nl += 4; i < nl; i++)
261 rp[i] = nrp[i], ap[i] = 0;
262 }
263#else
264 if (bn_sub_words (rp, ap, np, nl) - carry)
265 memcpy(rp, ap, nl*sizeof(BN_ULONG));
266#endif
267 bn_correct_top(r);
268 bn_correct_top(ret);
269 bn_check_top(ret);
270
271 return (1);
272}
273#endif /* MONT_WORD */
274
275int
276BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont, BN_CTX *ctx)
277{
278 int retn = 0;
279#ifdef MONT_WORD
280 BIGNUM *t;
281
282 BN_CTX_start(ctx);
283 if ((t = BN_CTX_get(ctx)) && BN_copy(t, a))
284 retn = BN_from_montgomery_word(ret, t, mont);
285 BN_CTX_end(ctx);
286#else /* !MONT_WORD */
287 BIGNUM *t1, *t2;
288
289 BN_CTX_start(ctx);
290 if ((t1 = BN_CTX_get(ctx)) == NULL)
291 goto err;
292 if ((t2 = BN_CTX_get(ctx)) == NULL)
293 goto err;
294
295 if (!BN_copy(t1, a))
296 goto err;
297 BN_mask_bits(t1, mont->ri);
298
299 if (!BN_mul(t2, t1, &mont->Ni, ctx))
300 goto err;
301 BN_mask_bits(t2, mont->ri);
302
303 if (!BN_mul(t1, t2, &mont->N, ctx))
304 goto err;
305 if (!BN_add(t2, a, t1))
306 goto err;
307 if (!BN_rshift(ret, t2, mont->ri))
308 goto err;
309
310 if (BN_ucmp(ret, &(mont->N)) >= 0) {
311 if (!BN_usub(ret, ret, &(mont->N)))
312 goto err;
313 }
314 retn = 1;
315 bn_check_top(ret);
316
317err:
318 BN_CTX_end(ctx);
319#endif /* MONT_WORD */
320 return (retn);
321}
322
323BN_MONT_CTX *
324BN_MONT_CTX_new(void)
325{
326 BN_MONT_CTX *ret;
327
328 if ((ret = malloc(sizeof(BN_MONT_CTX))) == NULL)
329 return (NULL);
330
331 BN_MONT_CTX_init(ret);
332 ret->flags = BN_FLG_MALLOCED;
333 return (ret);
334}
335
336void
337BN_MONT_CTX_init(BN_MONT_CTX *ctx)
338{
339 ctx->ri = 0;
340 BN_init(&(ctx->RR));
341 BN_init(&(ctx->N));
342 BN_init(&(ctx->Ni));
343 ctx->n0[0] = ctx->n0[1] = 0;
344 ctx->flags = 0;
345}
346
347void
348BN_MONT_CTX_free(BN_MONT_CTX *mont)
349{
350 if (mont == NULL)
351 return;
352
353 BN_clear_free(&(mont->RR));
354 BN_clear_free(&(mont->N));
355 BN_clear_free(&(mont->Ni));
356 if (mont->flags & BN_FLG_MALLOCED)
357 free(mont);
358}
359
360int
361BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
362{
363 int ret = 0;
364 BIGNUM *Ri, *R;
365
366 BN_CTX_start(ctx);
367 if ((Ri = BN_CTX_get(ctx)) == NULL)
368 goto err;
369 R = &(mont->RR); /* grab RR as a temp */
370 if (!BN_copy(&(mont->N), mod))
371 goto err; /* Set N */
372 mont->N.neg = 0;
373
374#ifdef MONT_WORD
375 {
376 BIGNUM tmod;
377 BN_ULONG buf[2];
378
379 BN_init(&tmod);
380 tmod.d = buf;
381 tmod.dmax = 2;
382 tmod.neg = 0;
383
384 mont->ri = (BN_num_bits(mod) +
385 (BN_BITS2 - 1)) / BN_BITS2 * BN_BITS2;
386
387#if defined(OPENSSL_BN_ASM_MONT) && (BN_BITS2<=32)
388 /* Only certain BN_BITS2<=32 platforms actually make use of
389 * n0[1], and we could use the #else case (with a shorter R
390 * value) for the others. However, currently only the assembler
391 * files do know which is which. */
392
393 BN_zero(R);
394 if (!(BN_set_bit(R, 2 * BN_BITS2)))
395 goto err;
396
397 tmod.top = 0;
398 if ((buf[0] = mod->d[0]))
399 tmod.top = 1;
400 if ((buf[1] = mod->top > 1 ? mod->d[1] : 0))
401 tmod.top = 2;
402
403 if ((BN_mod_inverse(Ri, R, &tmod, ctx)) == NULL)
404 goto err;
405 if (!BN_lshift(Ri, Ri, 2 * BN_BITS2))
406 goto err; /* R*Ri */
407 if (!BN_is_zero(Ri)) {
408 if (!BN_sub_word(Ri, 1))
409 goto err;
410 }
411 else /* if N mod word size == 1 */
412 {
413 if (bn_expand(Ri, (int)sizeof(BN_ULONG) * 2) == NULL)
414 goto err;
415 /* Ri-- (mod double word size) */
416 Ri->neg = 0;
417 Ri->d[0] = BN_MASK2;
418 Ri->d[1] = BN_MASK2;
419 Ri->top = 2;
420 }
421 if (!BN_div(Ri, NULL, Ri, &tmod, ctx))
422 goto err;
423 /* Ni = (R*Ri-1)/N,
424 * keep only couple of least significant words: */
425 mont->n0[0] = (Ri->top > 0) ? Ri->d[0] : 0;
426 mont->n0[1] = (Ri->top > 1) ? Ri->d[1] : 0;
427#else
428 BN_zero(R);
429 if (!(BN_set_bit(R, BN_BITS2)))
430 goto err; /* R */
431
432 buf[0] = mod->d[0]; /* tmod = N mod word size */
433 buf[1] = 0;
434 tmod.top = buf[0] != 0 ? 1 : 0;
435 /* Ri = R^-1 mod N*/
436 if ((BN_mod_inverse(Ri, R, &tmod, ctx)) == NULL)
437 goto err;
438 if (!BN_lshift(Ri, Ri, BN_BITS2))
439 goto err; /* R*Ri */
440 if (!BN_is_zero(Ri)) {
441 if (!BN_sub_word(Ri, 1))
442 goto err;
443 }
444 else /* if N mod word size == 1 */
445 {
446 if (!BN_set_word(Ri, BN_MASK2))
447 goto err; /* Ri-- (mod word size) */
448 }
449 if (!BN_div(Ri, NULL, Ri, &tmod, ctx))
450 goto err;
451 /* Ni = (R*Ri-1)/N,
452 * keep only least significant word: */
453 mont->n0[0] = (Ri->top > 0) ? Ri->d[0] : 0;
454 mont->n0[1] = 0;
455#endif
456 }
457#else /* !MONT_WORD */
458 { /* bignum version */
459 mont->ri = BN_num_bits(&mont->N);
460 BN_zero(R);
461 if (!BN_set_bit(R, mont->ri))
462 goto err; /* R = 2^ri */
463 /* Ri = R^-1 mod N*/
464 if ((BN_mod_inverse(Ri, R, &mont->N, ctx)) == NULL)
465 goto err;
466 if (!BN_lshift(Ri, Ri, mont->ri))
467 goto err; /* R*Ri */
468 if (!BN_sub_word(Ri, 1))
469 goto err;
470 /* Ni = (R*Ri-1) / N */
471 if (!BN_div(&(mont->Ni), NULL, Ri, &mont->N, ctx))
472 goto err;
473 }
474#endif
475
476 /* setup RR for conversions */
477 BN_zero(&(mont->RR));
478 if (!BN_set_bit(&(mont->RR), mont->ri*2))
479 goto err;
480 if (!BN_mod(&(mont->RR), &(mont->RR), &(mont->N), ctx))
481 goto err;
482
483 ret = 1;
484
485err:
486 BN_CTX_end(ctx);
487 return ret;
488}
489
490BN_MONT_CTX *
491BN_MONT_CTX_copy(BN_MONT_CTX *to, BN_MONT_CTX *from)
492{
493 if (to == from)
494 return (to);
495
496 if (!BN_copy(&(to->RR), &(from->RR)))
497 return NULL;
498 if (!BN_copy(&(to->N), &(from->N)))
499 return NULL;
500 if (!BN_copy(&(to->Ni), &(from->Ni)))
501 return NULL;
502 to->ri = from->ri;
503 to->n0[0] = from->n0[0];
504 to->n0[1] = from->n0[1];
505 return (to);
506}
507
508BN_MONT_CTX *
509BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, int lock, const BIGNUM *mod,
510 BN_CTX *ctx)
511{
512 int got_write_lock = 0;
513 BN_MONT_CTX *ret;
514
515 CRYPTO_r_lock(lock);
516 if (!*pmont) {
517 CRYPTO_r_unlock(lock);
518 CRYPTO_w_lock(lock);
519 got_write_lock = 1;
520
521 if (!*pmont) {
522 ret = BN_MONT_CTX_new();
523 if (ret && !BN_MONT_CTX_set(ret, mod, ctx))
524 BN_MONT_CTX_free(ret);
525 else
526 *pmont = ret;
527 }
528 }
529
530 ret = *pmont;
531
532 if (got_write_lock)
533 CRYPTO_w_unlock(lock);
534 else
535 CRYPTO_r_unlock(lock);
536
537 return ret;
538}
generated by cgit v1.2.3-55-g6feb (git 2.39.1) at 2025-08-14 20:31:48 +0000