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