1 /*
2 * Copyright 1995-2025 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 /*
11 * NB: these functions have been "upgraded", the deprecated versions (which
12 * are compatibility wrappers using these functions) are in rsa_depr.c. -
13 * Geoff
14 */
15
16 /*
17 * RSA low level APIs are deprecated for public use, but still ok for
18 * internal use.
19 */
20 #include "internal/deprecated.h"
21
22 #include <stdio.h>
23 #include <time.h>
24 #include "internal/cryptlib.h"
25 #include <openssl/bn.h>
26 #include <openssl/self_test.h>
27 #include "prov/providercommon.h"
28 #include "rsa_local.h"
29
30 static int rsa_keygen_pairwise_test(RSA *rsa, OSSL_CALLBACK *cb, void *cbarg);
31 static int rsa_keygen(OSSL_LIB_CTX *libctx, RSA *rsa, int bits, int primes,
32 BIGNUM *e_value, BN_GENCB *cb, int pairwise_test);
33
34 /*
35 * NB: this wrapper would normally be placed in rsa_lib.c and the static
36 * implementation would probably be in rsa_eay.c. Nonetheless, is kept here
37 * so that we don't introduce a new linker dependency. Eg. any application
38 * that wasn't previously linking object code related to key-generation won't
39 * have to now just because key-generation is part of RSA_METHOD.
40 */
RSA_generate_key_ex(RSA * rsa,int bits,BIGNUM * e_value,BN_GENCB * cb)41 int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
42 {
43 if (rsa->meth->rsa_keygen != NULL)
44 return rsa->meth->rsa_keygen(rsa, bits, e_value, cb);
45
46 return RSA_generate_multi_prime_key(rsa, bits, RSA_DEFAULT_PRIME_NUM,
47 e_value, cb);
48 }
49
RSA_generate_multi_prime_key(RSA * rsa,int bits,int primes,BIGNUM * e_value,BN_GENCB * cb)50 int RSA_generate_multi_prime_key(RSA *rsa, int bits, int primes,
51 BIGNUM *e_value, BN_GENCB *cb)
52 {
53 #ifndef FIPS_MODULE
54 /* multi-prime is only supported with the builtin key generation */
55 if (rsa->meth->rsa_multi_prime_keygen != NULL) {
56 return rsa->meth->rsa_multi_prime_keygen(rsa, bits, primes,
57 e_value, cb);
58 } else if (rsa->meth->rsa_keygen != NULL) {
59 /*
60 * However, if rsa->meth implements only rsa_keygen, then we
61 * have to honour it in 2-prime case and assume that it wouldn't
62 * know what to do with multi-prime key generated by builtin
63 * subroutine...
64 */
65 if (primes == 2)
66 return rsa->meth->rsa_keygen(rsa, bits, e_value, cb);
67 else
68 return 0;
69 }
70 #endif /* FIPS_MODULE */
71 return rsa_keygen(rsa->libctx, rsa, bits, primes, e_value, cb, 0);
72 }
73
DEFINE_STACK_OF(BIGNUM)74 DEFINE_STACK_OF(BIGNUM)
75
76 /*
77 * Given input values, q, p, n, d and e, derive the exponents
78 * and coefficients for each prime in this key, placing the result
79 * on their respective exps and coeffs stacks
80 */
81 #ifndef FIPS_MODULE
82 int ossl_rsa_multiprime_derive(RSA *rsa, int bits, int primes,
83 BIGNUM *e_value,
84 STACK_OF(BIGNUM) *factors,
85 STACK_OF(BIGNUM) *exps,
86 STACK_OF(BIGNUM) *coeffs)
87 {
88 STACK_OF(BIGNUM) *pplist = NULL, *pdlist = NULL;
89 BIGNUM *factor = NULL, *newpp = NULL, *newpd = NULL;
90 BIGNUM *dval = NULL, *newexp = NULL, *newcoeff = NULL;
91 BIGNUM *p = NULL, *q = NULL;
92 BIGNUM *dmp1 = NULL, *dmq1 = NULL, *iqmp = NULL;
93 BIGNUM *r0 = NULL, *r1 = NULL, *r2 = NULL;
94 BN_CTX *ctx = NULL;
95 BIGNUM *tmp = NULL;
96 int i;
97 int ret = 0;
98
99 ctx = BN_CTX_new_ex(rsa->libctx);
100 if (ctx == NULL)
101 goto err;
102
103 BN_CTX_start(ctx);
104
105 pplist = sk_BIGNUM_new_null();
106 if (pplist == NULL)
107 goto err;
108
109 pdlist = sk_BIGNUM_new_null();
110 if (pdlist == NULL)
111 goto err;
112
113 r0 = BN_CTX_get(ctx);
114 r1 = BN_CTX_get(ctx);
115 r2 = BN_CTX_get(ctx);
116
117 if (r2 == NULL)
118 goto err;
119
120 BN_set_flags(r0, BN_FLG_CONSTTIME);
121 BN_set_flags(r1, BN_FLG_CONSTTIME);
122 BN_set_flags(r2, BN_FLG_CONSTTIME);
123
124 if (BN_copy(r1, rsa->n) == NULL)
125 goto err;
126
127 p = sk_BIGNUM_value(factors, 0);
128 q = sk_BIGNUM_value(factors, 1);
129
130 /* Build list of partial products of primes */
131 for (i = 0; i < sk_BIGNUM_num(factors); i++) {
132 switch (i) {
133 case 0:
134 /* our first prime, p */
135 if (!BN_sub(r2, p, BN_value_one()))
136 goto err;
137 BN_set_flags(r2, BN_FLG_CONSTTIME);
138 if (BN_mod_inverse(r1, r2, rsa->e, ctx) == NULL)
139 goto err;
140 break;
141 case 1:
142 /* second prime q */
143 if (!BN_mul(r1, p, q, ctx))
144 goto err;
145 tmp = BN_dup(r1);
146 if (tmp == NULL)
147 goto err;
148 if (!sk_BIGNUM_insert(pplist, tmp, sk_BIGNUM_num(pplist)))
149 goto err;
150 tmp = NULL;
151 break;
152 default:
153 factor = sk_BIGNUM_value(factors, i);
154 /* all other primes */
155 if (!BN_mul(r1, r1, factor, ctx))
156 goto err;
157 tmp = BN_dup(r1);
158 if (tmp == NULL)
159 goto err;
160 if (!sk_BIGNUM_insert(pplist, tmp, sk_BIGNUM_num(pplist)))
161 goto err;
162 tmp = NULL;
163 break;
164 }
165 }
166
167 /* build list of relative d values */
168 /* p -1 */
169 if (!BN_sub(r1, p, BN_value_one()))
170 goto err;
171 if (!BN_sub(r2, q, BN_value_one()))
172 goto err;
173 if (!BN_mul(r0, r1, r2, ctx))
174 goto err;
175 for (i = 2; i < sk_BIGNUM_num(factors); i++) {
176 factor = sk_BIGNUM_value(factors, i);
177 dval = BN_new();
178 if (dval == NULL)
179 goto err;
180 BN_set_flags(dval, BN_FLG_CONSTTIME);
181 if (!BN_sub(dval, factor, BN_value_one()))
182 goto err;
183 if (!BN_mul(r0, r0, dval, ctx))
184 goto err;
185 if (!sk_BIGNUM_insert(pdlist, dval, sk_BIGNUM_num(pdlist)))
186 goto err;
187 dval = NULL;
188 }
189
190 /* Calculate dmp1, dmq1 and additional exponents */
191 dmp1 = BN_secure_new();
192 if (dmp1 == NULL)
193 goto err;
194 dmq1 = BN_secure_new();
195 if (dmq1 == NULL)
196 goto err;
197
198 if (!BN_mod(dmp1, rsa->d, r1, ctx))
199 goto err;
200 if (!sk_BIGNUM_insert(exps, dmp1, sk_BIGNUM_num(exps)))
201 goto err;
202 dmp1 = NULL;
203
204 if (!BN_mod(dmq1, rsa->d, r2, ctx))
205 goto err;
206 if (!sk_BIGNUM_insert(exps, dmq1, sk_BIGNUM_num(exps)))
207 goto err;
208 dmq1 = NULL;
209
210 for (i = 2; i < sk_BIGNUM_num(factors); i++) {
211 newpd = sk_BIGNUM_value(pdlist, i - 2);
212 newexp = BN_new();
213 if (newexp == NULL)
214 goto err;
215 if (!BN_mod(newexp, rsa->d, newpd, ctx))
216 goto err;
217 if (!sk_BIGNUM_insert(exps, newexp, sk_BIGNUM_num(exps)))
218 goto err;
219 newexp = NULL;
220 }
221
222 /* Calculate iqmp and additional coefficients */
223 iqmp = BN_new();
224 if (iqmp == NULL)
225 goto err;
226
227 if (BN_mod_inverse(iqmp, sk_BIGNUM_value(factors, 1),
228 sk_BIGNUM_value(factors, 0), ctx)
229 == NULL)
230 goto err;
231 if (!sk_BIGNUM_insert(coeffs, iqmp, sk_BIGNUM_num(coeffs)))
232 goto err;
233 iqmp = NULL;
234
235 for (i = 2; i < sk_BIGNUM_num(factors); i++) {
236 newpp = sk_BIGNUM_value(pplist, i - 2);
237 newcoeff = BN_new();
238 if (newcoeff == NULL)
239 goto err;
240 if (BN_mod_inverse(newcoeff, newpp, sk_BIGNUM_value(factors, i),
241 ctx)
242 == NULL)
243 goto err;
244 if (!sk_BIGNUM_insert(coeffs, newcoeff, sk_BIGNUM_num(coeffs)))
245 goto err;
246 newcoeff = NULL;
247 }
248
249 ret = 1;
250 err:
251 BN_free(newcoeff);
252 BN_free(newexp);
253 BN_free(dval);
254 BN_free(tmp);
255 sk_BIGNUM_pop_free(pplist, BN_free);
256 sk_BIGNUM_pop_free(pdlist, BN_free);
257 BN_CTX_end(ctx);
258 BN_CTX_free(ctx);
259 BN_clear_free(dmp1);
260 BN_clear_free(dmq1);
261 BN_clear_free(iqmp);
262 return ret;
263 }
264
rsa_multiprime_keygen(RSA * rsa,int bits,int primes,BIGNUM * e_value,BN_GENCB * cb)265 static int rsa_multiprime_keygen(RSA *rsa, int bits, int primes,
266 BIGNUM *e_value, BN_GENCB *cb)
267 {
268 BIGNUM *r0 = NULL, *r1 = NULL, *r2 = NULL, *tmp, *tmp2, *prime;
269 int n = 0, bitsr[RSA_MAX_PRIME_NUM], bitse = 0;
270 int i = 0, quo = 0, rmd = 0, adj = 0, retries = 0;
271 RSA_PRIME_INFO *pinfo = NULL;
272 STACK_OF(RSA_PRIME_INFO) *prime_infos = NULL;
273 STACK_OF(BIGNUM) *factors = NULL;
274 STACK_OF(BIGNUM) *exps = NULL;
275 STACK_OF(BIGNUM) *coeffs = NULL;
276 BN_CTX *ctx = NULL;
277 BN_ULONG bitst = 0;
278 unsigned long error = 0;
279 int ok = -1;
280
281 if (bits < RSA_MIN_MODULUS_BITS) {
282 ERR_raise(ERR_LIB_RSA, RSA_R_KEY_SIZE_TOO_SMALL);
283 return 0;
284 }
285 if (e_value == NULL) {
286 ERR_raise(ERR_LIB_RSA, RSA_R_BAD_E_VALUE);
287 return 0;
288 }
289 /* A bad value for e can cause infinite loops */
290 if (!ossl_rsa_check_public_exponent(e_value)) {
291 ERR_raise(ERR_LIB_RSA, RSA_R_PUB_EXPONENT_OUT_OF_RANGE);
292 return 0;
293 }
294
295 if (primes < RSA_DEFAULT_PRIME_NUM || primes > ossl_rsa_multip_cap(bits)) {
296 ERR_raise(ERR_LIB_RSA, RSA_R_KEY_PRIME_NUM_INVALID);
297 return 0;
298 }
299
300 factors = sk_BIGNUM_new_null();
301 if (factors == NULL)
302 return 0;
303
304 exps = sk_BIGNUM_new_null();
305 if (exps == NULL)
306 goto err;
307
308 coeffs = sk_BIGNUM_new_null();
309 if (coeffs == NULL)
310 goto err;
311
312 ctx = BN_CTX_new_ex(rsa->libctx);
313 if (ctx == NULL)
314 goto err;
315 BN_CTX_start(ctx);
316 r0 = BN_CTX_get(ctx);
317 r1 = BN_CTX_get(ctx);
318 r2 = BN_CTX_get(ctx);
319 if (r2 == NULL)
320 goto err;
321
322 /* divide bits into 'primes' pieces evenly */
323 quo = bits / primes;
324 rmd = bits % primes;
325
326 for (i = 0; i < primes; i++)
327 bitsr[i] = (i < rmd) ? quo + 1 : quo;
328
329 rsa->dirty_cnt++;
330
331 /* We need the RSA components non-NULL */
332 if (!rsa->n && ((rsa->n = BN_new()) == NULL))
333 goto err;
334 if (!rsa->d && ((rsa->d = BN_secure_new()) == NULL))
335 goto err;
336 BN_set_flags(rsa->d, BN_FLG_CONSTTIME);
337 if (!rsa->e && ((rsa->e = BN_new()) == NULL))
338 goto err;
339 if (!rsa->p && ((rsa->p = BN_secure_new()) == NULL))
340 goto err;
341 BN_set_flags(rsa->p, BN_FLG_CONSTTIME);
342 if (!rsa->q && ((rsa->q = BN_secure_new()) == NULL))
343 goto err;
344 BN_set_flags(rsa->q, BN_FLG_CONSTTIME);
345
346 /* initialize multi-prime components */
347 if (primes > RSA_DEFAULT_PRIME_NUM) {
348 rsa->version = RSA_ASN1_VERSION_MULTI;
349 prime_infos = sk_RSA_PRIME_INFO_new_reserve(NULL, primes - 2);
350 if (prime_infos == NULL)
351 goto err;
352 if (rsa->prime_infos != NULL) {
353 /* could this happen? */
354 sk_RSA_PRIME_INFO_pop_free(rsa->prime_infos,
355 ossl_rsa_multip_info_free);
356 }
357 rsa->prime_infos = prime_infos;
358
359 /* prime_info from 2 to |primes| -1 */
360 for (i = 2; i < primes; i++) {
361 pinfo = ossl_rsa_multip_info_new();
362 if (pinfo == NULL)
363 goto err;
364 (void)sk_RSA_PRIME_INFO_push(prime_infos, pinfo);
365 }
366 }
367
368 if (BN_copy(rsa->e, e_value) == NULL)
369 goto err;
370
371 /* generate p, q and other primes (if any) */
372 for (i = 0; i < primes; i++) {
373 adj = 0;
374 retries = 0;
375
376 if (i == 0) {
377 prime = rsa->p;
378 } else if (i == 1) {
379 prime = rsa->q;
380 } else {
381 pinfo = sk_RSA_PRIME_INFO_value(prime_infos, i - 2);
382 prime = pinfo->r;
383 }
384 BN_set_flags(prime, BN_FLG_CONSTTIME);
385
386 for (;;) {
387 redo:
388 if (!BN_generate_prime_ex2(prime, bitsr[i] + adj, 0, NULL, NULL,
389 cb, ctx))
390 goto err;
391 /*
392 * prime should not be equal to p, q, r_3...
393 * (those primes prior to this one)
394 */
395 {
396 int j;
397
398 for (j = 0; j < i; j++) {
399 BIGNUM *prev_prime;
400
401 if (j == 0)
402 prev_prime = rsa->p;
403 else if (j == 1)
404 prev_prime = rsa->q;
405 else
406 prev_prime = sk_RSA_PRIME_INFO_value(prime_infos,
407 j - 2)
408 ->r;
409
410 if (!BN_cmp(prime, prev_prime)) {
411 goto redo;
412 }
413 }
414 }
415 if (!BN_sub(r2, prime, BN_value_one()))
416 goto err;
417 ERR_set_mark();
418 BN_set_flags(r2, BN_FLG_CONSTTIME);
419 if (BN_mod_inverse(r1, r2, rsa->e, ctx) != NULL) {
420 /* GCD == 1 since inverse exists */
421 break;
422 }
423 error = ERR_peek_last_error();
424 if (ERR_GET_LIB(error) == ERR_LIB_BN
425 && ERR_GET_REASON(error) == BN_R_NO_INVERSE) {
426 /* GCD != 1 */
427 ERR_pop_to_mark();
428 } else {
429 goto err;
430 }
431 if (!BN_GENCB_call(cb, 2, n++))
432 goto err;
433 }
434
435 bitse += bitsr[i];
436
437 /* calculate n immediately to see if it's sufficient */
438 if (i == 1) {
439 /* we get at least 2 primes */
440 if (!BN_mul(r1, rsa->p, rsa->q, ctx))
441 goto err;
442 } else if (i != 0) {
443 /* modulus n = p * q * r_3 * r_4 ... */
444 if (!BN_mul(r1, rsa->n, prime, ctx))
445 goto err;
446 } else {
447 /* i == 0, do nothing */
448 if (!BN_GENCB_call(cb, 3, i))
449 goto err;
450 tmp = BN_dup(prime);
451 if (tmp == NULL)
452 goto err;
453 if (!sk_BIGNUM_insert(factors, tmp, sk_BIGNUM_num(factors)))
454 goto err;
455 continue;
456 }
457
458 /*
459 * if |r1|, product of factors so far, is not as long as expected
460 * (by checking the first 4 bits are less than 0x9 or greater than
461 * 0xF). If so, re-generate the last prime.
462 *
463 * NOTE: This actually can't happen in two-prime case, because of
464 * the way factors are generated.
465 *
466 * Besides, another consideration is, for multi-prime case, even the
467 * length modulus is as long as expected, the modulus could start at
468 * 0x8, which could be utilized to distinguish a multi-prime private
469 * key by using the modulus in a certificate. This is also covered
470 * by checking the length should not be less than 0x9.
471 */
472 if (!BN_rshift(r2, r1, bitse - 4))
473 goto err;
474 bitst = BN_get_word(r2);
475
476 if (bitst < 0x9 || bitst > 0xF) {
477 /*
478 * For keys with more than 4 primes, we attempt longer factor to
479 * meet length requirement.
480 *
481 * Otherwise, we just re-generate the prime with the same length.
482 *
483 * This strategy has the following goals:
484 *
485 * 1. 1024-bit factors are efficient when using 3072 and 4096-bit key
486 * 2. stay the same logic with normal 2-prime key
487 */
488 bitse -= bitsr[i];
489 if (!BN_GENCB_call(cb, 2, n++))
490 goto err;
491 if (primes > 4) {
492 if (bitst < 0x9)
493 adj++;
494 else
495 adj--;
496 } else if (retries == 4) {
497 /*
498 * re-generate all primes from scratch, mainly used
499 * in 4 prime case to avoid long loop. Max retry times
500 * is set to 4.
501 */
502 i = -1;
503 bitse = 0;
504 sk_BIGNUM_pop_free(factors, BN_clear_free);
505 factors = sk_BIGNUM_new_null();
506 if (factors == NULL)
507 goto err;
508 continue;
509 }
510 retries++;
511 goto redo;
512 }
513 /* save product of primes for further use, for multi-prime only */
514 if (i > 1 && BN_copy(pinfo->pp, rsa->n) == NULL)
515 goto err;
516 if (BN_copy(rsa->n, r1) == NULL)
517 goto err;
518 if (!BN_GENCB_call(cb, 3, i))
519 goto err;
520 tmp = BN_dup(prime);
521 if (tmp == NULL)
522 goto err;
523 if (!sk_BIGNUM_insert(factors, tmp, sk_BIGNUM_num(factors)))
524 goto err;
525 }
526
527 if (BN_cmp(rsa->p, rsa->q) < 0) {
528 tmp = rsa->p;
529 rsa->p = rsa->q;
530 rsa->q = tmp;
531 /* mirror this in our factor stack */
532 if (!sk_BIGNUM_insert(factors, sk_BIGNUM_delete(factors, 0), 1))
533 goto err;
534 }
535
536 /* calculate d */
537
538 /* p - 1 */
539 if (!BN_sub(r1, rsa->p, BN_value_one()))
540 goto err;
541 /* q - 1 */
542 if (!BN_sub(r2, rsa->q, BN_value_one()))
543 goto err;
544 /* (p - 1)(q - 1) */
545 if (!BN_mul(r0, r1, r2, ctx))
546 goto err;
547 /* multi-prime */
548 for (i = 2; i < primes; i++) {
549 pinfo = sk_RSA_PRIME_INFO_value(prime_infos, i - 2);
550 /* save r_i - 1 to pinfo->d temporarily */
551 if (!BN_sub(pinfo->d, pinfo->r, BN_value_one()))
552 goto err;
553 if (!BN_mul(r0, r0, pinfo->d, ctx))
554 goto err;
555 }
556
557 BN_set_flags(r0, BN_FLG_CONSTTIME);
558 if (BN_mod_inverse(rsa->d, rsa->e, r0, ctx) == NULL) {
559 goto err; /* d */
560 }
561
562 /* derive any missing exponents and coefficients */
563 if (!ossl_rsa_multiprime_derive(rsa, bits, primes, e_value,
564 factors, exps, coeffs))
565 goto err;
566
567 /*
568 * first 2 factors/exps are already tracked in p/q/dmq1/dmp1
569 * and the first coeff is in iqmp, so pop those off the stack
570 * Note, the first 2 factors/exponents are already tracked by p and q
571 * assign dmp1/dmq1 and iqmp
572 * the remaining pinfo values are separately allocated, so copy and delete
573 * those
574 */
575 BN_clear_free(sk_BIGNUM_delete(factors, 0));
576 BN_clear_free(sk_BIGNUM_delete(factors, 0));
577 rsa->dmp1 = sk_BIGNUM_delete(exps, 0);
578 rsa->dmq1 = sk_BIGNUM_delete(exps, 0);
579 rsa->iqmp = sk_BIGNUM_delete(coeffs, 0);
580 for (i = 2; i < primes; i++) {
581 pinfo = sk_RSA_PRIME_INFO_value(prime_infos, i - 2);
582 tmp = sk_BIGNUM_delete(factors, 0);
583 BN_copy(pinfo->r, tmp);
584 BN_clear_free(tmp);
585 tmp = sk_BIGNUM_delete(exps, 0);
586 tmp2 = BN_copy(pinfo->d, tmp);
587 BN_clear_free(tmp);
588 if (tmp2 == NULL)
589 goto err;
590 tmp = sk_BIGNUM_delete(coeffs, 0);
591 tmp2 = BN_copy(pinfo->t, tmp);
592 BN_clear_free(tmp);
593 if (tmp2 == NULL)
594 goto err;
595 }
596 ok = 1;
597 err:
598 sk_BIGNUM_free(factors);
599 sk_BIGNUM_free(exps);
600 sk_BIGNUM_free(coeffs);
601 if (ok == -1) {
602 ERR_raise(ERR_LIB_RSA, ERR_R_BN_LIB);
603 ok = 0;
604 }
605 BN_CTX_end(ctx);
606 BN_CTX_free(ctx);
607 return ok;
608 }
609 #endif /* FIPS_MODULE */
610
rsa_keygen(OSSL_LIB_CTX * libctx,RSA * rsa,int bits,int primes,BIGNUM * e_value,BN_GENCB * cb,int pairwise_test)611 static int rsa_keygen(OSSL_LIB_CTX *libctx, RSA *rsa, int bits, int primes,
612 BIGNUM *e_value, BN_GENCB *cb, int pairwise_test)
613 {
614 int ok = 0;
615
616 #ifdef FIPS_MODULE
617 ok = ossl_rsa_sp800_56b_generate_key(rsa, bits, e_value, cb);
618 pairwise_test = 1; /* FIPS MODE needs to always run the pairwise test */
619 #else
620 /*
621 * Only multi-prime keys or insecure keys with a small key length or a
622 * public exponent <= 2^16 will use the older rsa_multiprime_keygen().
623 */
624 if (primes == 2
625 && bits >= 2048
626 && (e_value == NULL || BN_num_bits(e_value) > 16))
627 ok = ossl_rsa_sp800_56b_generate_key(rsa, bits, e_value, cb);
628 else
629 ok = rsa_multiprime_keygen(rsa, bits, primes, e_value, cb);
630 #endif /* FIPS_MODULE */
631
632 if (pairwise_test && ok > 0) {
633 OSSL_CALLBACK *stcb = NULL;
634 void *stcbarg = NULL;
635
636 OSSL_SELF_TEST_get_callback(libctx, &stcb, &stcbarg);
637 ok = rsa_keygen_pairwise_test(rsa, stcb, stcbarg);
638 if (!ok) {
639 ossl_set_error_state(OSSL_SELF_TEST_TYPE_PCT);
640 /* Clear intermediate results */
641 BN_clear_free(rsa->d);
642 BN_clear_free(rsa->p);
643 BN_clear_free(rsa->q);
644 BN_clear_free(rsa->dmp1);
645 BN_clear_free(rsa->dmq1);
646 BN_clear_free(rsa->iqmp);
647 rsa->d = NULL;
648 rsa->p = NULL;
649 rsa->q = NULL;
650 rsa->dmp1 = NULL;
651 rsa->dmq1 = NULL;
652 rsa->iqmp = NULL;
653 }
654 }
655 return ok;
656 }
657
658 /*
659 * AS10.35 (and its VEs/TEs) of the FIPS 140-3 standard requires a PCT for every
660 * generated key pair. There are 3 options:
661 * 1) If the key pair is to be used for key transport (asymmetric cipher), the
662 * PCT consists of encrypting a plaintext, verifying that the result
663 * (ciphertext) is not equal to the plaintext, decrypting the ciphertext, and
664 * verifying that the result is equal to the plaintext.
665 * 2) If the key pair is to be used for digital signatures, the PCT consists of
666 * computing and verifying a signature.
667 * 3) If the key pair is to be used for key agreement, the exact PCT is defined
668 * in the applicable standards. For RSA-based schemes, this is defined in
669 * SP 800-56Br2 (Section 6.4.1.1) as:
670 * "The owner shall perform a pair-wise consistency test by verifying that m
671 * = (m^e)^d mod n for some integer m satisfying 1 < m < (n - 1)."
672 *
673 * OpenSSL implements all three use cases: RSA-OAEP for key transport,
674 * RSA signatures with PKCS#1 v1.5 or PSS padding, and KAS-IFC-SSC (KAS1/KAS2)
675 * using RSASVE.
676 *
677 * According to FIPS 140-3 IG 10.3.A, if at the time when the PCT is performed
678 * the keys' intended usage is not known, then any of the three PCTs described
679 * in AS10.35 shall be performed on this key pair.
680 *
681 * Because of this allowance from the IG, the simplest option is 3, i.e.
682 * RSA_public_encrypt() and RSA_private_decrypt() with RSA_NO_PADDING.
683 */
rsa_keygen_pairwise_test(RSA * rsa,OSSL_CALLBACK * cb,void * cbarg)684 static int rsa_keygen_pairwise_test(RSA *rsa, OSSL_CALLBACK *cb, void *cbarg)
685 {
686 int ret = 0;
687 unsigned char *plaintxt = NULL;
688 unsigned char *ciphertxt = NULL;
689 unsigned char *decoded = NULL;
690 int plaintxt_len;
691 int ciphertxt_len;
692 int decoded_len;
693 int padding = RSA_NO_PADDING;
694 OSSL_SELF_TEST *st = NULL;
695
696 st = OSSL_SELF_TEST_new(cb, cbarg);
697 if (st == NULL)
698 goto err;
699 OSSL_SELF_TEST_onbegin(st, OSSL_SELF_TEST_TYPE_PCT,
700 OSSL_SELF_TEST_DESC_PCT_RSA);
701
702 /*
703 * For RSA_NO_PADDING, RSA_public_encrypt() and RSA_private_decrypt()
704 * require the 'to' and 'from' parameters to have equal length and a
705 * maximum of RSA_size() - allocate space for plaintxt, ciphertxt, and
706 * decoded.
707 */
708 plaintxt_len = RSA_size(rsa);
709 plaintxt = OPENSSL_zalloc(plaintxt_len * 3);
710 if (plaintxt == NULL)
711 goto err;
712 ciphertxt = plaintxt + plaintxt_len;
713 decoded = ciphertxt + plaintxt_len;
714
715 /* SP 800-56Br2 Section 6.4.1.1 requires that plaintext is greater than 1 */
716 plaintxt[plaintxt_len - 1] = 2;
717
718 ciphertxt_len = RSA_public_encrypt(plaintxt_len, plaintxt, ciphertxt, rsa,
719 padding);
720 if (ciphertxt_len <= 0)
721 goto err;
722
723 OSSL_SELF_TEST_oncorrupt_byte(st, ciphertxt);
724
725 decoded_len = RSA_private_decrypt(ciphertxt_len, ciphertxt, decoded, rsa,
726 padding);
727 if (decoded_len != plaintxt_len
728 || memcmp(decoded, plaintxt, decoded_len) != 0)
729 goto err;
730
731 ret = 1;
732 err:
733 OSSL_SELF_TEST_onend(st, ret);
734 OSSL_SELF_TEST_free(st);
735 OPENSSL_free(plaintxt);
736
737 return ret;
738 }
739