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>
67 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
68 unsigned char *to, RSA *rsa,int padding);
69 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
70 unsigned char *to, RSA *rsa,int padding);
71 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
72 unsigned char *to, RSA *rsa,int padding);
73 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
74 unsigned char *to, RSA *rsa,int padding);
75 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa);
76 static int RSA_eay_init(RSA *rsa);
77 static int RSA_eay_finish(RSA *rsa);
78 static RSA_METHOD rsa_pkcs1_eay_meth={
79 "Eric Young's PKCS#1 RSA",
80 RSA_eay_public_encrypt,
81 RSA_eay_public_decrypt, /* signature verification */
82 RSA_eay_private_encrypt, /* signing */
83 RSA_eay_private_decrypt,
85 BN_mod_exp_mont, /* XXX probably we should not use Montgomery if e == 3 */
95 const RSA_METHOD *RSA_PKCS1_SSLeay(void)
97 return(&rsa_pkcs1_eay_meth);
100 /* Static helper to reduce oodles of code duplication. As a slight
101 * optimisation, the "MONT_HELPER() macro must be used as front-end to this
102 * function, to prevent unnecessary function calls - there is an initial test
103 * that is performed by the macro-generated code. */
104 static int rsa_eay_mont_helper(BN_MONT_CTX **ptr, const BIGNUM *modulus, BN_CTX *ctx)
106 BN_MONT_CTX *bn_mont_ctx;
107 if((bn_mont_ctx = BN_MONT_CTX_new()) == NULL)
109 if(!BN_MONT_CTX_set(bn_mont_ctx, modulus, ctx))
111 BN_MONT_CTX_free(bn_mont_ctx);
114 if (*ptr == NULL) /* other thread may have finished first */
116 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
117 if (*ptr == NULL) /* check again in the lock to stop races */
122 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
125 BN_MONT_CTX_free(bn_mont_ctx);
129 * MONT_HELPER(rsa, bn_ctx, p, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
131 #define MONT_HELPER(rsa, ctx, m, pre_cond, err_instr) \
132 if((pre_cond) && ((rsa)->_method_mod_##m == NULL) && \
133 !rsa_eay_mont_helper(&((rsa)->_method_mod_##m), \
137 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
138 unsigned char *to, RSA *rsa, int padding)
141 int i,j,k,num=0,r= -1;
142 unsigned char *buf=NULL;
147 if ((ctx=BN_CTX_new()) == NULL) goto err;
148 num=BN_num_bytes(rsa->n);
149 if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
151 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);
157 case RSA_PKCS1_PADDING:
158 i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen);
160 #ifndef OPENSSL_NO_SHA
161 case RSA_PKCS1_OAEP_PADDING:
162 i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0);
165 case RSA_SSLV23_PADDING:
166 i=RSA_padding_add_SSLv23(buf,num,from,flen);
169 i=RSA_padding_add_none(buf,num,from,flen);
172 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
175 if (i <= 0) goto err;
177 if (BN_bin2bn(buf,num,&f) == NULL) goto err;
179 if (BN_ucmp(&f, rsa->n) >= 0)
181 /* usually the padding functions would catch this */
182 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
186 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
188 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->e,rsa->n,ctx,
189 rsa->_method_mod_n)) goto err;
191 /* put in leading 0 bytes if the number is less than the
192 * length of the modulus */
193 j=BN_num_bytes(&ret);
194 i=BN_bn2bin(&ret,&(to[num-j]));
195 for (k=0; k<(num-i); k++)
200 if (ctx != NULL) BN_CTX_free(ctx);
205 OPENSSL_cleanse(buf,num);
211 static int rsa_eay_blinding(RSA *rsa, BN_CTX *ctx)
214 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
215 /* Check again inside the lock - the macro's check is racey */
216 if(rsa->blinding == NULL)
217 ret = RSA_blinding_on(rsa, ctx);
218 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
222 #define BLINDING_HELPER(rsa, ctx, err_instr) \
224 if((!((rsa)->flags & RSA_FLAG_NO_BLINDING)) && \
225 ((rsa)->blinding == NULL) && \
226 !rsa_eay_blinding(rsa, ctx)) \
230 static BN_BLINDING *setup_blinding(RSA *rsa, BN_CTX *ctx)
233 BN_BLINDING *ret = NULL;
235 /* added in OpenSSL 0.9.6j and 0.9.7b */
237 /* NB: similar code appears in RSA_blinding_on (rsa_lib.c);
238 * this should be placed in a new function of its own, but for reasons
239 * of binary compatibility can't */
243 if ((RAND_status() == 0) && rsa->d != NULL && rsa->d->d != NULL)
245 /* if PRNG is not properly seeded, resort to secret exponent as unpredictable seed */
246 RAND_add(rsa->d->d, rsa->d->dmax * sizeof rsa->d->d[0], 0);
247 if (!BN_pseudo_rand_range(A,rsa->n)) goto err;
251 if (!BN_rand_range(A,rsa->n)) goto err;
253 if ((Ai=BN_mod_inverse(NULL,A,rsa->n,ctx)) == NULL) goto err;
255 if (!rsa->meth->bn_mod_exp(A,A,rsa->e,rsa->n,ctx,rsa->_method_mod_n))
257 ret = BN_BLINDING_new(A,Ai,rsa->n);
265 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
266 unsigned char *to, RSA *rsa, int padding)
269 int i,j,k,num=0,r= -1;
270 unsigned char *buf=NULL;
272 int local_blinding = 0;
273 BN_BLINDING *blinding = NULL;
278 if ((ctx=BN_CTX_new()) == NULL) goto err;
279 num=BN_num_bytes(rsa->n);
280 if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
282 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
288 case RSA_PKCS1_PADDING:
289 i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen);
292 i=RSA_padding_add_none(buf,num,from,flen);
294 case RSA_SSLV23_PADDING:
296 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
299 if (i <= 0) goto err;
301 if (BN_bin2bn(buf,num,&f) == NULL) goto err;
303 if (BN_ucmp(&f, rsa->n) >= 0)
305 /* usually the padding functions would catch this */
306 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
310 BLINDING_HELPER(rsa, ctx, goto err;);
311 blinding = rsa->blinding;
313 /* Now unless blinding is disabled, 'blinding' is non-NULL.
314 * But the BN_BLINDING object may be owned by some other thread
315 * (we don't want to keep it constant and we don't want to use
316 * lots of locking to avoid race conditions, so only a single
317 * thread can use it; other threads have to use local blinding
319 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
321 if (blinding == NULL)
323 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
328 if (blinding != NULL)
330 if (blinding->thread_id != CRYPTO_thread_id())
332 /* we need a local one-time blinding factor */
334 blinding = setup_blinding(rsa, ctx);
335 if (blinding == NULL)
342 if (!BN_BLINDING_convert(&f, blinding, ctx)) goto err;
344 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
347 (rsa->dmp1 != NULL) &&
348 (rsa->dmq1 != NULL) &&
349 (rsa->iqmp != NULL)) )
350 { if (!rsa->meth->rsa_mod_exp(&ret,&f,rsa)) goto err; }
353 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
354 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->d,rsa->n,ctx,
355 rsa->_method_mod_n)) goto err;
359 if (!BN_BLINDING_invert(&ret, blinding, ctx)) goto err;
361 /* put in leading 0 bytes if the number is less than the
362 * length of the modulus */
363 j=BN_num_bytes(&ret);
364 i=BN_bn2bin(&ret,&(to[num-j]));
365 for (k=0; k<(num-i); k++)
370 if (ctx != NULL) BN_CTX_free(ctx);
374 BN_BLINDING_free(blinding);
377 OPENSSL_cleanse(buf,num);
383 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
384 unsigned char *to, RSA *rsa, int padding)
389 unsigned char *buf=NULL;
391 int local_blinding = 0;
392 BN_BLINDING *blinding = NULL;
397 if (ctx == NULL) goto err;
399 num=BN_num_bytes(rsa->n);
401 if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
403 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
407 /* This check was for equality but PGP does evil things
408 * and chops off the top '0' bytes */
411 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
415 /* make data into a big number */
416 if (BN_bin2bn(from,(int)flen,&f) == NULL) goto err;
418 if (BN_ucmp(&f, rsa->n) >= 0)
420 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
424 BLINDING_HELPER(rsa, ctx, goto err;);
425 blinding = rsa->blinding;
427 /* Now unless blinding is disabled, 'blinding' is non-NULL.
428 * But the BN_BLINDING object may be owned by some other thread
429 * (we don't want to keep it constant and we don't want to use
430 * lots of locking to avoid race conditions, so only a single
431 * thread can use it; other threads have to use local blinding
433 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
435 if (blinding == NULL)
437 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
442 if (blinding != NULL)
444 if (blinding->thread_id != CRYPTO_thread_id())
446 /* we need a local one-time blinding factor */
448 blinding = setup_blinding(rsa, ctx);
449 if (blinding == NULL)
456 if (!BN_BLINDING_convert(&f, blinding, ctx)) goto err;
459 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
462 (rsa->dmp1 != NULL) &&
463 (rsa->dmq1 != NULL) &&
464 (rsa->iqmp != NULL)) )
465 { if (!rsa->meth->rsa_mod_exp(&ret,&f,rsa)) goto err; }
468 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
469 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->d,rsa->n,ctx,
475 if (!BN_BLINDING_invert(&ret, blinding, ctx)) goto err;
478 j=BN_bn2bin(&ret,p); /* j is only used with no-padding mode */
482 case RSA_PKCS1_PADDING:
483 r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);
485 #ifndef OPENSSL_NO_SHA
486 case RSA_PKCS1_OAEP_PADDING:
487 r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);
490 case RSA_SSLV23_PADDING:
491 r=RSA_padding_check_SSLv23(to,num,buf,j,num);
494 r=RSA_padding_check_none(to,num,buf,j,num);
497 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
501 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
504 if (ctx != NULL) BN_CTX_free(ctx);
508 BN_BLINDING_free(blinding);
511 OPENSSL_cleanse(buf,num);
517 /* signature verification */
518 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
519 unsigned char *to, RSA *rsa, int padding)
524 unsigned char *buf=NULL;
530 if (ctx == NULL) goto err;
532 num=BN_num_bytes(rsa->n);
533 buf=(unsigned char *)OPENSSL_malloc(num);
536 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
540 /* This check was for equality but PGP does evil things
541 * and chops off the top '0' bytes */
544 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
548 if (BN_bin2bn(from,flen,&f) == NULL) goto err;
550 if (BN_ucmp(&f, rsa->n) >= 0)
552 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
556 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
558 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->e,rsa->n,ctx,
559 rsa->_method_mod_n)) goto err;
566 case RSA_PKCS1_PADDING:
567 r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);
570 r=RSA_padding_check_none(to,num,buf,i,num);
573 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
577 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
580 if (ctx != NULL) BN_CTX_free(ctx);
585 OPENSSL_cleanse(buf,num);
591 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa)
600 if ((ctx=BN_CTX_new()) == NULL) goto err;
602 MONT_HELPER(rsa, ctx, p, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
603 MONT_HELPER(rsa, ctx, q, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
604 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
606 if (!BN_mod(&r1,I,rsa->q,ctx)) goto err;
607 if (!rsa->meth->bn_mod_exp(&m1,&r1,rsa->dmq1,rsa->q,ctx,
608 rsa->_method_mod_q)) goto err;
610 if (!BN_mod(&r1,I,rsa->p,ctx)) goto err;
611 if (!rsa->meth->bn_mod_exp(r0,&r1,rsa->dmp1,rsa->p,ctx,
612 rsa->_method_mod_p)) goto err;
614 if (!BN_sub(r0,r0,&m1)) goto err;
615 /* This will help stop the size of r0 increasing, which does
616 * affect the multiply if it optimised for a power of 2 size */
618 if (!BN_add(r0,r0,rsa->p)) goto err;
620 if (!BN_mul(&r1,r0,rsa->iqmp,ctx)) goto err;
621 if (!BN_mod(r0,&r1,rsa->p,ctx)) goto err;
622 /* If p < q it is occasionally possible for the correction of
623 * adding 'p' if r0 is negative above to leave the result still
624 * negative. This can break the private key operations: the following
625 * second correction should *always* correct this rare occurrence.
626 * This will *never* happen with OpenSSL generated keys because
627 * they ensure p > q [steve]
630 if (!BN_add(r0,r0,rsa->p)) goto err;
631 if (!BN_mul(&r1,r0,rsa->q,ctx)) goto err;
632 if (!BN_add(r0,&r1,&m1)) goto err;
634 if (rsa->e && rsa->n)
636 if (!rsa->meth->bn_mod_exp(&vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err;
637 /* If 'I' was greater than (or equal to) rsa->n, the operation
638 * will be equivalent to using 'I mod n'. However, the result of
639 * the verify will *always* be less than 'n' so we don't check
640 * for absolute equality, just congruency. */
641 if (!BN_sub(&vrfy, &vrfy, I)) goto err;
642 if (!BN_mod(&vrfy, &vrfy, rsa->n, ctx)) goto err;
643 if (BN_get_sign(&vrfy))
644 if (!BN_add(&vrfy, &vrfy, rsa->n)) goto err;
645 if (!BN_is_zero(&vrfy))
646 /* 'I' and 'vrfy' aren't congruent mod n. Don't leak
647 * miscalculated CRT output, just do a raw (slower)
648 * mod_exp and return that instead. */
649 if (!rsa->meth->bn_mod_exp(r0,I,rsa->d,rsa->n,ctx,
650 rsa->_method_mod_n)) goto err;
656 BN_clear_free(&vrfy);
661 static int RSA_eay_init(RSA *rsa)
663 rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE;
667 static int RSA_eay_finish(RSA *rsa)
669 if (rsa->_method_mod_n != NULL)
670 BN_MONT_CTX_free(rsa->_method_mod_n);
671 if (rsa->_method_mod_p != NULL)
672 BN_MONT_CTX_free(rsa->_method_mod_p);
673 if (rsa->_method_mod_q != NULL)
674 BN_MONT_CTX_free(rsa->_method_mod_q);