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