1 /* crypto/rsa/rsa_eay.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
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)"
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
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.]
61 #include <openssl/bn.h>
62 #include <openssl/rsa.h>
63 #include <openssl/rand.h>
64 #ifndef OPENSSL_NO_ENGINE
65 #include <openssl/engine.h>
70 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
71 unsigned char *to, RSA *rsa,int padding);
72 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
73 unsigned char *to, RSA *rsa,int padding);
74 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
75 unsigned char *to, RSA *rsa,int padding);
76 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
77 unsigned char *to, RSA *rsa,int padding);
78 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa);
79 static int RSA_eay_init(RSA *rsa);
80 static int RSA_eay_finish(RSA *rsa);
81 static RSA_METHOD rsa_pkcs1_eay_meth={
82 "Eric Young's PKCS#1 RSA",
83 RSA_eay_public_encrypt,
84 RSA_eay_public_decrypt, /* signature verification */
85 RSA_eay_private_encrypt, /* signing */
86 RSA_eay_private_decrypt,
88 BN_mod_exp_mont, /* XXX probably we should not use Montgomery if e == 3 */
98 const RSA_METHOD *RSA_PKCS1_SSLeay(void)
100 return(&rsa_pkcs1_eay_meth);
103 /* Static helper to reduce oodles of code duplication. As a slight
104 * optimisation, the "MONT_HELPER() macro must be used as front-end to this
105 * function, to prevent unnecessary function calls - there is an initial test
106 * that is performed by the macro-generated code. */
107 static int rsa_eay_mont_helper(BN_MONT_CTX **ptr, const BIGNUM *modulus, BN_CTX *ctx)
109 BN_MONT_CTX *bn_mont_ctx;
110 if((bn_mont_ctx = BN_MONT_CTX_new()) == NULL)
112 if(!BN_MONT_CTX_set(bn_mont_ctx, modulus, ctx))
114 BN_MONT_CTX_free(bn_mont_ctx);
117 if (*ptr == NULL) /* other thread may have finished first */
119 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
120 if (*ptr == NULL) /* check again in the lock to stop races */
125 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
128 BN_MONT_CTX_free(bn_mont_ctx);
132 * MONT_HELPER(rsa, bn_ctx, p, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
134 #define MONT_HELPER(rsa, ctx, m, pre_cond, err_instr) \
135 if((pre_cond) && ((rsa)->_method_mod_##m == NULL) && \
136 !rsa_eay_mont_helper(&((rsa)->_method_mod_##m), \
140 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
141 unsigned char *to, RSA *rsa, int padding)
144 int i,j,k,num=0,r= -1;
145 unsigned char *buf=NULL;
150 if ((ctx=BN_CTX_new()) == NULL) goto err;
151 num=BN_num_bytes(rsa->n);
152 if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
154 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);
160 case RSA_PKCS1_PADDING:
161 i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen);
163 #ifndef OPENSSL_NO_SHA
164 case RSA_PKCS1_OAEP_PADDING:
165 i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0);
168 case RSA_SSLV23_PADDING:
169 i=RSA_padding_add_SSLv23(buf,num,from,flen);
172 i=RSA_padding_add_none(buf,num,from,flen);
175 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
178 if (i <= 0) goto err;
180 if (BN_bin2bn(buf,num,&f) == NULL) goto err;
182 if (BN_ucmp(&f, rsa->n) >= 0)
184 /* usually the padding functions would catch this */
185 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
189 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
191 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->e,rsa->n,ctx,
192 rsa->_method_mod_n)) goto err;
194 /* put in leading 0 bytes if the number is less than the
195 * length of the modulus */
196 j=BN_num_bytes(&ret);
197 i=BN_bn2bin(&ret,&(to[num-j]));
198 for (k=0; k<(num-i); k++)
203 if (ctx != NULL) BN_CTX_free(ctx);
208 OPENSSL_cleanse(buf,num);
214 static int rsa_eay_blinding(RSA *rsa, BN_CTX *ctx)
217 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
218 /* Check again inside the lock - the macro's check is racey */
219 if(rsa->blinding == NULL)
220 ret = RSA_blinding_on(rsa, ctx);
221 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
225 #define BLINDING_HELPER(rsa, ctx, err_instr) \
227 if((!((rsa)->flags & RSA_FLAG_NO_BLINDING)) && \
228 ((rsa)->blinding == NULL) && \
229 !rsa_eay_blinding(rsa, ctx)) \
233 static BN_BLINDING *setup_blinding(RSA *rsa, BN_CTX *ctx)
236 BN_BLINDING *ret = NULL;
238 /* added in OpenSSL 0.9.6j and 0.9.7b */
240 /* NB: similar code appears in RSA_blinding_on (rsa_lib.c);
241 * this should be placed in a new function of its own, but for reasons
242 * of binary compatibility can't */
246 if ((RAND_status() == 0) && rsa->d != NULL && rsa->d->d != NULL)
248 /* if PRNG is not properly seeded, resort to secret exponent as unpredictable seed */
249 RAND_add(rsa->d->d, rsa->d->dmax * sizeof rsa->d->d[0], 0);
250 if (!BN_pseudo_rand_range(A,rsa->n)) goto err;
254 if (!BN_rand_range(A,rsa->n)) goto err;
256 if ((Ai=BN_mod_inverse(NULL,A,rsa->n,ctx)) == NULL) goto err;
258 if (!rsa->meth->bn_mod_exp(A,A,rsa->e,rsa->n,ctx,rsa->_method_mod_n))
260 ret = BN_BLINDING_new(A,Ai,rsa->n);
268 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
269 unsigned char *to, RSA *rsa, int padding)
272 int i,j,k,num=0,r= -1;
273 unsigned char *buf=NULL;
275 int local_blinding = 0;
276 BN_BLINDING *blinding = NULL;
281 if ((ctx=BN_CTX_new()) == NULL) goto err;
282 num=BN_num_bytes(rsa->n);
283 if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
285 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
291 case RSA_PKCS1_PADDING:
292 i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen);
295 i=RSA_padding_add_none(buf,num,from,flen);
297 case RSA_SSLV23_PADDING:
299 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
302 if (i <= 0) goto err;
304 if (BN_bin2bn(buf,num,&f) == NULL) goto err;
306 if (BN_ucmp(&f, rsa->n) >= 0)
308 /* usually the padding functions would catch this */
309 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
313 BLINDING_HELPER(rsa, ctx, goto err;);
314 blinding = rsa->blinding;
316 /* Now unless blinding is disabled, 'blinding' is non-NULL.
317 * But the BN_BLINDING object may be owned by some other thread
318 * (we don't want to keep it constant and we don't want to use
319 * lots of locking to avoid race conditions, so only a single
320 * thread can use it; other threads have to use local blinding
322 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
324 if (blinding == NULL)
326 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
331 if (blinding != NULL)
333 if (blinding->thread_id != CRYPTO_thread_id())
335 /* we need a local one-time blinding factor */
337 blinding = setup_blinding(rsa, ctx);
338 if (blinding == NULL)
345 if (!BN_BLINDING_convert(&f, blinding, ctx)) goto err;
347 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
350 (rsa->dmp1 != NULL) &&
351 (rsa->dmq1 != NULL) &&
352 (rsa->iqmp != NULL)) )
353 { if (!rsa->meth->rsa_mod_exp(&ret,&f,rsa)) goto err; }
356 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
357 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->d,rsa->n,ctx,
358 rsa->_method_mod_n)) goto err;
362 if (!BN_BLINDING_invert(&ret, blinding, ctx)) goto err;
364 /* put in leading 0 bytes if the number is less than the
365 * length of the modulus */
366 j=BN_num_bytes(&ret);
367 i=BN_bn2bin(&ret,&(to[num-j]));
368 for (k=0; k<(num-i); k++)
373 if (ctx != NULL) BN_CTX_free(ctx);
377 BN_BLINDING_free(blinding);
380 OPENSSL_cleanse(buf,num);
386 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
387 unsigned char *to, RSA *rsa, int padding)
392 unsigned char *buf=NULL;
394 int local_blinding = 0;
395 BN_BLINDING *blinding = NULL;
400 if (ctx == NULL) goto err;
402 num=BN_num_bytes(rsa->n);
404 if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
406 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
410 /* This check was for equality but PGP does evil things
411 * and chops off the top '0' bytes */
414 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
418 /* make data into a big number */
419 if (BN_bin2bn(from,(int)flen,&f) == NULL) goto err;
421 if (BN_ucmp(&f, rsa->n) >= 0)
423 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
427 BLINDING_HELPER(rsa, ctx, goto err;);
428 blinding = rsa->blinding;
430 /* Now unless blinding is disabled, 'blinding' is non-NULL.
431 * But the BN_BLINDING object may be owned by some other thread
432 * (we don't want to keep it constant and we don't want to use
433 * lots of locking to avoid race conditions, so only a single
434 * thread can use it; other threads have to use local blinding
436 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
438 if (blinding == NULL)
440 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
445 if (blinding != NULL)
447 if (blinding->thread_id != CRYPTO_thread_id())
449 /* we need a local one-time blinding factor */
451 blinding = setup_blinding(rsa, ctx);
452 if (blinding == NULL)
459 if (!BN_BLINDING_convert(&f, blinding, ctx)) goto err;
462 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
465 (rsa->dmp1 != NULL) &&
466 (rsa->dmq1 != NULL) &&
467 (rsa->iqmp != NULL)) )
468 { if (!rsa->meth->rsa_mod_exp(&ret,&f,rsa)) goto err; }
471 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
472 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->d,rsa->n,ctx,
478 if (!BN_BLINDING_invert(&ret, blinding, ctx)) goto err;
481 j=BN_bn2bin(&ret,p); /* j is only used with no-padding mode */
485 case RSA_PKCS1_PADDING:
486 r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);
488 #ifndef OPENSSL_NO_SHA
489 case RSA_PKCS1_OAEP_PADDING:
490 r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);
493 case RSA_SSLV23_PADDING:
494 r=RSA_padding_check_SSLv23(to,num,buf,j,num);
497 r=RSA_padding_check_none(to,num,buf,j,num);
500 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
504 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
507 if (ctx != NULL) BN_CTX_free(ctx);
512 OPENSSL_cleanse(buf,num);
518 /* signature verification */
519 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
520 unsigned char *to, RSA *rsa, int padding)
525 unsigned char *buf=NULL;
531 if (ctx == NULL) goto err;
533 num=BN_num_bytes(rsa->n);
534 buf=(unsigned char *)OPENSSL_malloc(num);
537 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
541 /* This check was for equality but PGP does evil things
542 * and chops off the top '0' bytes */
545 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
549 if (BN_bin2bn(from,flen,&f) == NULL) goto err;
551 if (BN_ucmp(&f, rsa->n) >= 0)
553 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
557 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
559 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->e,rsa->n,ctx,
560 rsa->_method_mod_n)) goto err;
567 case RSA_PKCS1_PADDING:
568 r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);
571 r=RSA_padding_check_none(to,num,buf,i,num);
574 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
578 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
581 if (ctx != NULL) BN_CTX_free(ctx);
586 OPENSSL_cleanse(buf,num);
592 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa)
601 if ((ctx=BN_CTX_new()) == NULL) goto err;
603 MONT_HELPER(rsa, ctx, p, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
604 MONT_HELPER(rsa, ctx, q, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
605 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
607 if (!BN_mod(&r1,I,rsa->q,ctx)) goto err;
608 if (!rsa->meth->bn_mod_exp(&m1,&r1,rsa->dmq1,rsa->q,ctx,
609 rsa->_method_mod_q)) goto err;
611 if (!BN_mod(&r1,I,rsa->p,ctx)) goto err;
612 if (!rsa->meth->bn_mod_exp(r0,&r1,rsa->dmp1,rsa->p,ctx,
613 rsa->_method_mod_p)) goto err;
615 if (!BN_sub(r0,r0,&m1)) goto err;
616 /* This will help stop the size of r0 increasing, which does
617 * affect the multiply if it optimised for a power of 2 size */
619 if (!BN_add(r0,r0,rsa->p)) goto err;
621 if (!BN_mul(&r1,r0,rsa->iqmp,ctx)) goto err;
622 if (!BN_mod(r0,&r1,rsa->p,ctx)) goto err;
623 /* If p < q it is occasionally possible for the correction of
624 * adding 'p' if r0 is negative above to leave the result still
625 * negative. This can break the private key operations: the following
626 * second correction should *always* correct this rare occurrence.
627 * This will *never* happen with OpenSSL generated keys because
628 * they ensure p > q [steve]
631 if (!BN_add(r0,r0,rsa->p)) goto err;
632 if (!BN_mul(&r1,r0,rsa->q,ctx)) goto err;
633 if (!BN_add(r0,&r1,&m1)) goto err;
635 if (rsa->e && rsa->n)
637 if (!rsa->meth->bn_mod_exp(&vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err;
638 /* If 'I' was greater than (or equal to) rsa->n, the operation
639 * will be equivalent to using 'I mod n'. However, the result of
640 * the verify will *always* be less than 'n' so we don't check
641 * for absolute equality, just congruency. */
642 if (!BN_sub(&vrfy, &vrfy, I)) goto err;
643 if (!BN_mod(&vrfy, &vrfy, rsa->n, ctx)) goto err;
644 if (BN_get_sign(&vrfy))
645 if (!BN_add(&vrfy, &vrfy, rsa->n)) goto err;
646 if (!BN_is_zero(&vrfy))
647 /* 'I' and 'vrfy' aren't congruent mod n. Don't leak
648 * miscalculated CRT output, just do a raw (slower)
649 * mod_exp and return that instead. */
650 if (!rsa->meth->bn_mod_exp(r0,I,rsa->d,rsa->n,ctx,
651 rsa->_method_mod_n)) goto err;
657 BN_clear_free(&vrfy);
662 static int RSA_eay_init(RSA *rsa)
664 rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE;
668 static int RSA_eay_finish(RSA *rsa)
670 if (rsa->_method_mod_n != NULL)
671 BN_MONT_CTX_free(rsa->_method_mod_n);
672 if (rsa->_method_mod_p != NULL)
673 BN_MONT_CTX_free(rsa->_method_mod_p);
674 if (rsa->_method_mod_q != NULL)
675 BN_MONT_CTX_free(rsa->_method_mod_q);