1 /* crypto/rsa/rsa_eay.c */
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 #include <stdio.h>
113 #include "cryptlib.h"
114 #include <openssl/bn.h>
115 #include <openssl/rsa.h>
116 #include <openssl/rand.h>
117
118 #ifndef RSA_NULL
119
120 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
121 unsigned char *to, RSA *rsa, int padding);
122 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
123 unsigned char *to, RSA *rsa, int padding);
124 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
125 unsigned char *to, RSA *rsa, int padding);
126 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
127 unsigned char *to, RSA *rsa, int padding);
128 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa,
129 BN_CTX *ctx);
130 static int RSA_eay_init(RSA *rsa);
131 static int RSA_eay_finish(RSA *rsa);
132 static RSA_METHOD rsa_pkcs1_eay_meth = {
133 "Eric Young's PKCS#1 RSA",
134 RSA_eay_public_encrypt,
135 RSA_eay_public_decrypt, /* signature verification */
136 RSA_eay_private_encrypt, /* signing */
137 RSA_eay_private_decrypt,
138 RSA_eay_mod_exp,
139 BN_mod_exp_mont, /* XXX probably we should not use Montgomery
140 * if e == 3 */
141 RSA_eay_init,
142 RSA_eay_finish,
143 0, /* flags */
144 NULL,
145 0, /* rsa_sign */
146 0, /* rsa_verify */
147 NULL /* rsa_keygen */
148 };
149
RSA_PKCS1_SSLeay(void)150 const RSA_METHOD *RSA_PKCS1_SSLeay(void)
151 {
152 return (&rsa_pkcs1_eay_meth);
153 }
154
RSA_eay_public_encrypt(int flen,const unsigned char * from,unsigned char * to,RSA * rsa,int padding)155 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
156 unsigned char *to, RSA *rsa, int padding)
157 {
158 BIGNUM *f, *ret;
159 int i, j, k, num = 0, r = -1;
160 unsigned char *buf = NULL;
161 BN_CTX *ctx = NULL;
162
163 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
164 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
165 return -1;
166 }
167
168 if (BN_ucmp(rsa->n, rsa->e) <= 0) {
169 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
170 return -1;
171 }
172
173 /* for large moduli, enforce exponent limit */
174 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
175 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
176 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
177 return -1;
178 }
179 }
180
181 if ((ctx = BN_CTX_new()) == NULL)
182 goto err;
183 BN_CTX_start(ctx);
184 f = BN_CTX_get(ctx);
185 ret = BN_CTX_get(ctx);
186 num = BN_num_bytes(rsa->n);
187 buf = OPENSSL_malloc(num);
188 if (!f || !ret || !buf) {
189 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, ERR_R_MALLOC_FAILURE);
190 goto err;
191 }
192
193 switch (padding) {
194 case RSA_PKCS1_PADDING:
195 i = RSA_padding_add_PKCS1_type_2(buf, num, from, flen);
196 break;
197 # ifndef OPENSSL_NO_SHA
198 case RSA_PKCS1_OAEP_PADDING:
199 i = RSA_padding_add_PKCS1_OAEP(buf, num, from, flen, NULL, 0);
200 break;
201 # endif
202 case RSA_SSLV23_PADDING:
203 i = RSA_padding_add_SSLv23(buf, num, from, flen);
204 break;
205 case RSA_NO_PADDING:
206 i = RSA_padding_add_none(buf, num, from, flen);
207 break;
208 default:
209 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
210 goto err;
211 }
212 if (i <= 0)
213 goto err;
214
215 if (BN_bin2bn(buf, num, f) == NULL)
216 goto err;
217
218 if (BN_ucmp(f, rsa->n) >= 0) {
219 /* usually the padding functions would catch this */
220 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,
221 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
222 goto err;
223 }
224
225 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
226 if (!BN_MONT_CTX_set_locked
227 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
228 goto err;
229
230 if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
231 rsa->_method_mod_n))
232 goto err;
233
234 /*
235 * put in leading 0 bytes if the number is less than the length of the
236 * modulus
237 */
238 j = BN_num_bytes(ret);
239 i = BN_bn2bin(ret, &(to[num - j]));
240 for (k = 0; k < (num - i); k++)
241 to[k] = 0;
242
243 r = num;
244 err:
245 if (ctx != NULL) {
246 BN_CTX_end(ctx);
247 BN_CTX_free(ctx);
248 }
249 if (buf != NULL) {
250 OPENSSL_cleanse(buf, num);
251 OPENSSL_free(buf);
252 }
253 return (r);
254 }
255
rsa_get_blinding(RSA * rsa,int * local,BN_CTX * ctx)256 static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
257 {
258 BN_BLINDING *ret;
259 int got_write_lock = 0;
260 CRYPTO_THREADID cur;
261
262 CRYPTO_r_lock(CRYPTO_LOCK_RSA);
263
264 if (rsa->blinding == NULL) {
265 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
266 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
267 got_write_lock = 1;
268
269 if (rsa->blinding == NULL)
270 rsa->blinding = RSA_setup_blinding(rsa, ctx);
271 }
272
273 ret = rsa->blinding;
274 if (ret == NULL)
275 goto err;
276
277 CRYPTO_THREADID_current(&cur);
278 if (!CRYPTO_THREADID_cmp(&cur, BN_BLINDING_thread_id(ret))) {
279 /* rsa->blinding is ours! */
280
281 *local = 1;
282 } else {
283 /* resort to rsa->mt_blinding instead */
284
285 /*
286 * instructs rsa_blinding_convert(), rsa_blinding_invert() that the
287 * BN_BLINDING is shared, meaning that accesses require locks, and
288 * that the blinding factor must be stored outside the BN_BLINDING
289 */
290 *local = 0;
291
292 if (rsa->mt_blinding == NULL) {
293 if (!got_write_lock) {
294 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
295 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
296 got_write_lock = 1;
297 }
298
299 if (rsa->mt_blinding == NULL)
300 rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
301 }
302 ret = rsa->mt_blinding;
303 }
304
305 err:
306 if (got_write_lock)
307 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
308 else
309 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
310 return ret;
311 }
312
rsa_blinding_convert(BN_BLINDING * b,BIGNUM * f,BIGNUM * unblind,BN_CTX * ctx)313 static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
314 BN_CTX *ctx)
315 {
316 if (unblind == NULL)
317 /*
318 * Local blinding: store the unblinding factor in BN_BLINDING.
319 */
320 return BN_BLINDING_convert_ex(f, NULL, b, ctx);
321 else {
322 /*
323 * Shared blinding: store the unblinding factor outside BN_BLINDING.
324 */
325 int ret;
326 CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
327 ret = BN_BLINDING_convert_ex(f, unblind, b, ctx);
328 CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
329 return ret;
330 }
331 }
332
rsa_blinding_invert(BN_BLINDING * b,BIGNUM * f,BIGNUM * unblind,BN_CTX * ctx)333 static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
334 BN_CTX *ctx)
335 {
336 /*
337 * For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex
338 * will use the unblinding factor stored in BN_BLINDING. If BN_BLINDING
339 * is shared between threads, unblind must be non-null:
340 * BN_BLINDING_invert_ex will then use the local unblinding factor, and
341 * will only read the modulus from BN_BLINDING. In both cases it's safe
342 * to access the blinding without a lock.
343 */
344 return BN_BLINDING_invert_ex(f, unblind, b, ctx);
345 }
346
347 /* signing */
RSA_eay_private_encrypt(int flen,const unsigned char * from,unsigned char * to,RSA * rsa,int padding)348 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
349 unsigned char *to, RSA *rsa, int padding)
350 {
351 BIGNUM *f, *ret, *res;
352 int i, j, k, num = 0, r = -1;
353 unsigned char *buf = NULL;
354 BN_CTX *ctx = NULL;
355 int local_blinding = 0;
356 /*
357 * Used only if the blinding structure is shared. A non-NULL unblind
358 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
359 * the unblinding factor outside the blinding structure.
360 */
361 BIGNUM *unblind = NULL;
362 BN_BLINDING *blinding = NULL;
363
364 if ((ctx = BN_CTX_new()) == NULL)
365 goto err;
366 BN_CTX_start(ctx);
367 f = BN_CTX_get(ctx);
368 ret = BN_CTX_get(ctx);
369 num = BN_num_bytes(rsa->n);
370 buf = OPENSSL_malloc(num);
371 if (!f || !ret || !buf) {
372 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
373 goto err;
374 }
375
376 switch (padding) {
377 case RSA_PKCS1_PADDING:
378 i = RSA_padding_add_PKCS1_type_1(buf, num, from, flen);
379 break;
380 case RSA_X931_PADDING:
381 i = RSA_padding_add_X931(buf, num, from, flen);
382 break;
383 case RSA_NO_PADDING:
384 i = RSA_padding_add_none(buf, num, from, flen);
385 break;
386 case RSA_SSLV23_PADDING:
387 default:
388 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
389 goto err;
390 }
391 if (i <= 0)
392 goto err;
393
394 if (BN_bin2bn(buf, num, f) == NULL)
395 goto err;
396
397 if (BN_ucmp(f, rsa->n) >= 0) {
398 /* usually the padding functions would catch this */
399 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,
400 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
401 goto err;
402 }
403
404 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
405 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
406 if (blinding == NULL) {
407 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
408 goto err;
409 }
410 }
411
412 if (blinding != NULL) {
413 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
414 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
415 goto err;
416 }
417 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
418 goto err;
419 }
420
421 if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
422 ((rsa->p != NULL) &&
423 (rsa->q != NULL) &&
424 (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) {
425 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
426 goto err;
427 } else {
428 BIGNUM local_d;
429 BIGNUM *d = NULL;
430
431 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
432 BN_init(&local_d);
433 d = &local_d;
434 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
435 } else
436 d = rsa->d;
437
438 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
439 if (!BN_MONT_CTX_set_locked
440 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
441 goto err;
442
443 if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
444 rsa->_method_mod_n))
445 goto err;
446 }
447
448 if (blinding)
449 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
450 goto err;
451
452 if (padding == RSA_X931_PADDING) {
453 BN_sub(f, rsa->n, ret);
454 if (BN_cmp(ret, f) > 0)
455 res = f;
456 else
457 res = ret;
458 } else
459 res = ret;
460
461 /*
462 * put in leading 0 bytes if the number is less than the length of the
463 * modulus
464 */
465 j = BN_num_bytes(res);
466 i = BN_bn2bin(res, &(to[num - j]));
467 for (k = 0; k < (num - i); k++)
468 to[k] = 0;
469
470 r = num;
471 err:
472 if (ctx != NULL) {
473 BN_CTX_end(ctx);
474 BN_CTX_free(ctx);
475 }
476 if (buf != NULL) {
477 OPENSSL_cleanse(buf, num);
478 OPENSSL_free(buf);
479 }
480 return (r);
481 }
482
RSA_eay_private_decrypt(int flen,const unsigned char * from,unsigned char * to,RSA * rsa,int padding)483 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
484 unsigned char *to, RSA *rsa, int padding)
485 {
486 BIGNUM *f, *ret;
487 int j, num = 0, r = -1;
488 unsigned char *p;
489 unsigned char *buf = NULL;
490 BN_CTX *ctx = NULL;
491 int local_blinding = 0;
492 /*
493 * Used only if the blinding structure is shared. A non-NULL unblind
494 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
495 * the unblinding factor outside the blinding structure.
496 */
497 BIGNUM *unblind = NULL;
498 BN_BLINDING *blinding = NULL;
499
500 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
501 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
502 return -1;
503 }
504
505 if (BN_ucmp(rsa->n, rsa->e) <= 0) {
506 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
507 return -1;
508 }
509
510 /* for large moduli, enforce exponent limit */
511 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
512 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
513 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
514 return -1;
515 }
516 }
517
518 if ((ctx = BN_CTX_new()) == NULL)
519 goto err;
520 BN_CTX_start(ctx);
521 f = BN_CTX_get(ctx);
522 ret = BN_CTX_get(ctx);
523 num = BN_num_bytes(rsa->n);
524 buf = OPENSSL_malloc(num);
525 if (!f || !ret || !buf) {
526 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
527 goto err;
528 }
529
530 /*
531 * This check was for equality but PGP does evil things and chops off the
532 * top '0' bytes
533 */
534 if (flen > num) {
535 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,
536 RSA_R_DATA_GREATER_THAN_MOD_LEN);
537 goto err;
538 }
539
540 /* make data into a big number */
541 if (BN_bin2bn(from, (int)flen, f) == NULL)
542 goto err;
543
544 if (BN_ucmp(f, rsa->n) >= 0) {
545 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,
546 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
547 goto err;
548 }
549
550 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
551 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
552 if (blinding == NULL) {
553 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
554 goto err;
555 }
556 }
557
558 if (blinding != NULL) {
559 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
560 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
561 goto err;
562 }
563 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
564 goto err;
565 }
566
567 /* do the decrypt */
568 if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
569 ((rsa->p != NULL) &&
570 (rsa->q != NULL) &&
571 (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) {
572 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
573 goto err;
574 } else {
575 BIGNUM local_d;
576 BIGNUM *d = NULL;
577
578 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
579 d = &local_d;
580 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
581 } else
582 d = rsa->d;
583
584 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
585 if (!BN_MONT_CTX_set_locked
586 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
587 goto err;
588 if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
589 rsa->_method_mod_n))
590 goto err;
591 }
592
593 if (blinding)
594 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
595 goto err;
596
597 p = buf;
598 j = BN_bn2bin(ret, p); /* j is only used with no-padding mode */
599
600 switch (padding) {
601 case RSA_PKCS1_PADDING:
602 r = RSA_padding_check_PKCS1_type_2(to, num, buf, j, num);
603 break;
604 # ifndef OPENSSL_NO_SHA
605 case RSA_PKCS1_OAEP_PADDING:
606 r = RSA_padding_check_PKCS1_OAEP(to, num, buf, j, num, NULL, 0);
607 break;
608 # endif
609 case RSA_SSLV23_PADDING:
610 r = RSA_padding_check_SSLv23(to, num, buf, j, num);
611 break;
612 case RSA_NO_PADDING:
613 r = RSA_padding_check_none(to, num, buf, j, num);
614 break;
615 default:
616 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
617 goto err;
618 }
619 if (r < 0)
620 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, RSA_R_PADDING_CHECK_FAILED);
621
622 err:
623 if (ctx != NULL) {
624 BN_CTX_end(ctx);
625 BN_CTX_free(ctx);
626 }
627 if (buf != NULL) {
628 OPENSSL_cleanse(buf, num);
629 OPENSSL_free(buf);
630 }
631 return (r);
632 }
633
634 /* signature verification */
RSA_eay_public_decrypt(int flen,const unsigned char * from,unsigned char * to,RSA * rsa,int padding)635 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
636 unsigned char *to, RSA *rsa, int padding)
637 {
638 BIGNUM *f, *ret;
639 int i, num = 0, r = -1;
640 unsigned char *p;
641 unsigned char *buf = NULL;
642 BN_CTX *ctx = NULL;
643
644 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
645 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
646 return -1;
647 }
648
649 if (BN_ucmp(rsa->n, rsa->e) <= 0) {
650 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
651 return -1;
652 }
653
654 /* for large moduli, enforce exponent limit */
655 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
656 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
657 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
658 return -1;
659 }
660 }
661
662 if ((ctx = BN_CTX_new()) == NULL)
663 goto err;
664 BN_CTX_start(ctx);
665 f = BN_CTX_get(ctx);
666 ret = BN_CTX_get(ctx);
667 num = BN_num_bytes(rsa->n);
668 buf = OPENSSL_malloc(num);
669 if (!f || !ret || !buf) {
670 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, ERR_R_MALLOC_FAILURE);
671 goto err;
672 }
673
674 /*
675 * This check was for equality but PGP does evil things and chops off the
676 * top '0' bytes
677 */
678 if (flen > num) {
679 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_DATA_GREATER_THAN_MOD_LEN);
680 goto err;
681 }
682
683 if (BN_bin2bn(from, flen, f) == NULL)
684 goto err;
685
686 if (BN_ucmp(f, rsa->n) >= 0) {
687 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,
688 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
689 goto err;
690 }
691
692 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
693 if (!BN_MONT_CTX_set_locked
694 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
695 goto err;
696
697 if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
698 rsa->_method_mod_n))
699 goto err;
700
701 if ((padding == RSA_X931_PADDING) && ((ret->d[0] & 0xf) != 12))
702 if (!BN_sub(ret, rsa->n, ret))
703 goto err;
704
705 p = buf;
706 i = BN_bn2bin(ret, p);
707
708 switch (padding) {
709 case RSA_PKCS1_PADDING:
710 r = RSA_padding_check_PKCS1_type_1(to, num, buf, i, num);
711 break;
712 case RSA_X931_PADDING:
713 r = RSA_padding_check_X931(to, num, buf, i, num);
714 break;
715 case RSA_NO_PADDING:
716 r = RSA_padding_check_none(to, num, buf, i, num);
717 break;
718 default:
719 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
720 goto err;
721 }
722 if (r < 0)
723 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_PADDING_CHECK_FAILED);
724
725 err:
726 if (ctx != NULL) {
727 BN_CTX_end(ctx);
728 BN_CTX_free(ctx);
729 }
730 if (buf != NULL) {
731 OPENSSL_cleanse(buf, num);
732 OPENSSL_free(buf);
733 }
734 return (r);
735 }
736
RSA_eay_mod_exp(BIGNUM * r0,const BIGNUM * I,RSA * rsa,BN_CTX * ctx)737 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
738 {
739 BIGNUM *r1, *m1, *vrfy;
740 BIGNUM local_dmp1, local_dmq1, local_c, local_r1;
741 BIGNUM *dmp1, *dmq1, *c, *pr1;
742 int ret = 0;
743
744 BN_CTX_start(ctx);
745 r1 = BN_CTX_get(ctx);
746 m1 = BN_CTX_get(ctx);
747 vrfy = BN_CTX_get(ctx);
748
749 {
750 BIGNUM local_p, local_q;
751 BIGNUM *p = NULL, *q = NULL;
752
753 /*
754 * Make sure BN_mod_inverse in Montgomery intialization uses the
755 * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
756 */
757 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
758 BN_init(&local_p);
759 p = &local_p;
760 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
761
762 BN_init(&local_q);
763 q = &local_q;
764 BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
765 } else {
766 p = rsa->p;
767 q = rsa->q;
768 }
769
770 if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) {
771 if (!BN_MONT_CTX_set_locked
772 (&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx))
773 goto err;
774 if (!BN_MONT_CTX_set_locked
775 (&rsa->_method_mod_q, CRYPTO_LOCK_RSA, q, ctx))
776 goto err;
777 }
778 }
779
780 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
781 if (!BN_MONT_CTX_set_locked
782 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
783 goto err;
784
785 /* compute I mod q */
786 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
787 c = &local_c;
788 BN_with_flags(c, I, BN_FLG_CONSTTIME);
789 if (!BN_mod(r1, c, rsa->q, ctx))
790 goto err;
791 } else {
792 if (!BN_mod(r1, I, rsa->q, ctx))
793 goto err;
794 }
795
796 /* compute r1^dmq1 mod q */
797 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
798 dmq1 = &local_dmq1;
799 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
800 } else
801 dmq1 = rsa->dmq1;
802 if (!rsa->meth->bn_mod_exp(m1, r1, dmq1, rsa->q, ctx, rsa->_method_mod_q))
803 goto err;
804
805 /* compute I mod p */
806 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
807 c = &local_c;
808 BN_with_flags(c, I, BN_FLG_CONSTTIME);
809 if (!BN_mod(r1, c, rsa->p, ctx))
810 goto err;
811 } else {
812 if (!BN_mod(r1, I, rsa->p, ctx))
813 goto err;
814 }
815
816 /* compute r1^dmp1 mod p */
817 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
818 dmp1 = &local_dmp1;
819 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
820 } else
821 dmp1 = rsa->dmp1;
822 if (!rsa->meth->bn_mod_exp(r0, r1, dmp1, rsa->p, ctx, rsa->_method_mod_p))
823 goto err;
824
825 if (!BN_sub(r0, r0, m1))
826 goto err;
827 /*
828 * This will help stop the size of r0 increasing, which does affect the
829 * multiply if it optimised for a power of 2 size
830 */
831 if (BN_is_negative(r0))
832 if (!BN_add(r0, r0, rsa->p))
833 goto err;
834
835 if (!BN_mul(r1, r0, rsa->iqmp, ctx))
836 goto err;
837
838 /* Turn BN_FLG_CONSTTIME flag on before division operation */
839 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
840 pr1 = &local_r1;
841 BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
842 } else
843 pr1 = r1;
844 if (!BN_mod(r0, pr1, rsa->p, ctx))
845 goto err;
846
847 /*
848 * If p < q it is occasionally possible for the correction of adding 'p'
849 * if r0 is negative above to leave the result still negative. This can
850 * break the private key operations: the following second correction
851 * should *always* correct this rare occurrence. This will *never* happen
852 * with OpenSSL generated keys because they ensure p > q [steve]
853 */
854 if (BN_is_negative(r0))
855 if (!BN_add(r0, r0, rsa->p))
856 goto err;
857 if (!BN_mul(r1, r0, rsa->q, ctx))
858 goto err;
859 if (!BN_add(r0, r1, m1))
860 goto err;
861
862 if (rsa->e && rsa->n) {
863 if (!rsa->meth->bn_mod_exp(vrfy, r0, rsa->e, rsa->n, ctx,
864 rsa->_method_mod_n))
865 goto err;
866 /*
867 * If 'I' was greater than (or equal to) rsa->n, the operation will
868 * be equivalent to using 'I mod n'. However, the result of the
869 * verify will *always* be less than 'n' so we don't check for
870 * absolute equality, just congruency.
871 */
872 if (!BN_sub(vrfy, vrfy, I))
873 goto err;
874 if (!BN_mod(vrfy, vrfy, rsa->n, ctx))
875 goto err;
876 if (BN_is_negative(vrfy))
877 if (!BN_add(vrfy, vrfy, rsa->n))
878 goto err;
879 if (!BN_is_zero(vrfy)) {
880 /*
881 * 'I' and 'vrfy' aren't congruent mod n. Don't leak
882 * miscalculated CRT output, just do a raw (slower) mod_exp and
883 * return that instead.
884 */
885
886 BIGNUM local_d;
887 BIGNUM *d = NULL;
888
889 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
890 d = &local_d;
891 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
892 } else
893 d = rsa->d;
894 if (!rsa->meth->bn_mod_exp(r0, I, d, rsa->n, ctx,
895 rsa->_method_mod_n))
896 goto err;
897 }
898 }
899 ret = 1;
900 err:
901 BN_CTX_end(ctx);
902 return (ret);
903 }
904
RSA_eay_init(RSA * rsa)905 static int RSA_eay_init(RSA *rsa)
906 {
907 rsa->flags |= RSA_FLAG_CACHE_PUBLIC | RSA_FLAG_CACHE_PRIVATE;
908 return (1);
909 }
910
RSA_eay_finish(RSA * rsa)911 static int RSA_eay_finish(RSA *rsa)
912 {
913 if (rsa->_method_mod_n != NULL)
914 BN_MONT_CTX_free(rsa->_method_mod_n);
915 if (rsa->_method_mod_p != NULL)
916 BN_MONT_CTX_free(rsa->_method_mod_p);
917 if (rsa->_method_mod_q != NULL)
918 BN_MONT_CTX_free(rsa->_method_mod_q);
919 return (1);
920 }
921
922 #endif
923