1/* crypto/rsa/rsa_lib.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#include <stdio.h>
60#include <openssl/crypto.h>
61#include "cryptlib.h"
62#include <openssl/lhash.h>
63#include <openssl/bn.h>
64#include <openssl/rsa.h>
65#include <openssl/rand.h>
66#ifndef OPENSSL_NO_ENGINE
67#include <openssl/engine.h>
68#endif
69
70int RSA_size(const RSA *r)
71	{
72	return(BN_num_bytes(r->n));
73	}
74
75int RSA_public_encrypt(int flen, const unsigned char *from, unsigned char *to,
76	     RSA *rsa, int padding)
77	{
78#ifdef OPENSSL_FIPS
79	if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)
80			&& !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW))
81		{
82		RSAerr(RSA_F_RSA_PUBLIC_ENCRYPT, RSA_R_NON_FIPS_RSA_METHOD);
83		return -1;
84		}
85#endif
86	return(rsa->meth->rsa_pub_enc(flen, from, to, rsa, padding));
87	}
88
89int RSA_private_encrypt(int flen, const unsigned char *from, unsigned char *to,
90	     RSA *rsa, int padding)
91	{
92#ifdef OPENSSL_FIPS
93	if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)
94			&& !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW))
95		{
96		RSAerr(RSA_F_RSA_PRIVATE_ENCRYPT, RSA_R_NON_FIPS_RSA_METHOD);
97		return -1;
98		}
99#endif
100	return(rsa->meth->rsa_priv_enc(flen, from, to, rsa, padding));
101	}
102
103int RSA_private_decrypt(int flen, const unsigned char *from, unsigned char *to,
104	     RSA *rsa, int padding)
105	{
106#ifdef OPENSSL_FIPS
107	if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)
108			&& !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW))
109		{
110		RSAerr(RSA_F_RSA_PRIVATE_DECRYPT, RSA_R_NON_FIPS_RSA_METHOD);
111		return -1;
112		}
113#endif
114	return(rsa->meth->rsa_priv_dec(flen, from, to, rsa, padding));
115	}
116
117int RSA_public_decrypt(int flen, const unsigned char *from, unsigned char *to,
118	     RSA *rsa, int padding)
119	{
120#ifdef OPENSSL_FIPS
121	if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)
122			&& !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW))
123		{
124		RSAerr(RSA_F_RSA_PUBLIC_DECRYPT, RSA_R_NON_FIPS_RSA_METHOD);
125		return -1;
126		}
127#endif
128	return(rsa->meth->rsa_pub_dec(flen, from, to, rsa, padding));
129	}
130
131int RSA_flags(const RSA *r)
132	{
133	return((r == NULL)?0:r->meth->flags);
134	}
135
136void RSA_blinding_off(RSA *rsa)
137	{
138	if (rsa->blinding != NULL)
139		{
140		BN_BLINDING_free(rsa->blinding);
141		rsa->blinding=NULL;
142		}
143	rsa->flags &= ~RSA_FLAG_BLINDING;
144	rsa->flags |= RSA_FLAG_NO_BLINDING;
145	}
146
147int RSA_blinding_on(RSA *rsa, BN_CTX *ctx)
148	{
149	int ret=0;
150
151	if (rsa->blinding != NULL)
152		RSA_blinding_off(rsa);
153
154	rsa->blinding = RSA_setup_blinding(rsa, ctx);
155	if (rsa->blinding == NULL)
156		goto err;
157
158	rsa->flags |= RSA_FLAG_BLINDING;
159	rsa->flags &= ~RSA_FLAG_NO_BLINDING;
160	ret=1;
161err:
162	return(ret);
163	}
164
165static BIGNUM *rsa_get_public_exp(const BIGNUM *d, const BIGNUM *p,
166	const BIGNUM *q, BN_CTX *ctx)
167{
168	BIGNUM *ret = NULL, *r0, *r1, *r2;
169
170	if (d == NULL || p == NULL || q == NULL)
171		return NULL;
172
173	BN_CTX_start(ctx);
174	r0 = BN_CTX_get(ctx);
175	r1 = BN_CTX_get(ctx);
176	r2 = BN_CTX_get(ctx);
177	if (r2 == NULL)
178		goto err;
179
180	if (!BN_sub(r1, p, BN_value_one())) goto err;
181	if (!BN_sub(r2, q, BN_value_one())) goto err;
182	if (!BN_mul(r0, r1, r2, ctx)) goto err;
183
184	ret = BN_mod_inverse(NULL, d, r0, ctx);
185err:
186	BN_CTX_end(ctx);
187	return ret;
188}
189
190BN_BLINDING *RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx)
191{
192	BIGNUM local_n;
193	BIGNUM *e,*n;
194	BN_CTX *ctx;
195	BN_BLINDING *ret = NULL;
196
197	if (in_ctx == NULL)
198		{
199		if ((ctx = BN_CTX_new()) == NULL) return 0;
200		}
201	else
202		ctx = in_ctx;
203
204	BN_CTX_start(ctx);
205	e  = BN_CTX_get(ctx);
206	if (e == NULL)
207		{
208		RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_MALLOC_FAILURE);
209		goto err;
210		}
211
212	if (rsa->e == NULL)
213		{
214		e = rsa_get_public_exp(rsa->d, rsa->p, rsa->q, ctx);
215		if (e == NULL)
216			{
217			RSAerr(RSA_F_RSA_SETUP_BLINDING, RSA_R_NO_PUBLIC_EXPONENT);
218			goto err;
219			}
220		}
221	else
222		e = rsa->e;
223
224
225	if ((RAND_status() == 0) && rsa->d != NULL && rsa->d->d != NULL)
226		{
227		/* if PRNG is not properly seeded, resort to secret
228		 * exponent as unpredictable seed */
229		RAND_add(rsa->d->d, rsa->d->dmax * sizeof rsa->d->d[0], 0.0);
230		}
231
232	if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
233		{
234		/* Set BN_FLG_CONSTTIME flag */
235		n = &local_n;
236		BN_with_flags(n, rsa->n, BN_FLG_CONSTTIME);
237		}
238	else
239		n = rsa->n;
240
241	ret = BN_BLINDING_create_param(NULL, e, n, ctx,
242			rsa->meth->bn_mod_exp, rsa->_method_mod_n);
243	if (ret == NULL)
244		{
245		RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_BN_LIB);
246		goto err;
247		}
248	CRYPTO_THREADID_current(BN_BLINDING_thread_id(ret));
249err:
250	BN_CTX_end(ctx);
251	if (in_ctx == NULL)
252		BN_CTX_free(ctx);
253	if(rsa->e == NULL)
254		BN_free(e);
255
256	return ret;
257}
258