rsa_crpt.c revision 331638 
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        RSAerr(RSA_F_RSA_PUBLIC_ENCRYPT, RSA_R_NON_FIPS_RSA_METHOD);
82        return -1;
83    }
84#endif
85    return (rsa->meth->rsa_pub_enc(flen, from, to, rsa, padding));
86}
87
88int RSA_private_encrypt(int flen, const unsigned char *from,
89                        unsigned char *to, RSA *rsa, int padding)
90{
91#ifdef OPENSSL_FIPS
92    if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)
93        && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) {
94        RSAerr(RSA_F_RSA_PRIVATE_ENCRYPT, RSA_R_NON_FIPS_RSA_METHOD);
95        return -1;
96    }
97#endif
98    return (rsa->meth->rsa_priv_enc(flen, from, to, rsa, padding));
99}
100
101int RSA_private_decrypt(int flen, const unsigned char *from,
102                        unsigned char *to, RSA *rsa, int padding)
103{
104#ifdef OPENSSL_FIPS
105    if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)
106        && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) {
107        RSAerr(RSA_F_RSA_PRIVATE_DECRYPT, RSA_R_NON_FIPS_RSA_METHOD);
108        return -1;
109    }
110#endif
111    return (rsa->meth->rsa_priv_dec(flen, from, to, rsa, padding));
112}
113
114int RSA_public_decrypt(int flen, const unsigned char *from, unsigned char *to,
115                       RSA *rsa, int padding)
116{
117#ifdef OPENSSL_FIPS
118    if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)
119        && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) {
120        RSAerr(RSA_F_RSA_PUBLIC_DECRYPT, RSA_R_NON_FIPS_RSA_METHOD);
121        return -1;
122    }
123#endif
124    return (rsa->meth->rsa_pub_dec(flen, from, to, rsa, padding));
125}
126
127int RSA_flags(const RSA *r)
128{
129    return ((r == NULL) ? 0 : r->meth->flags);
130}
131
132void RSA_blinding_off(RSA *rsa)
133{
134    if (rsa->blinding != NULL) {
135        BN_BLINDING_free(rsa->blinding);
136        rsa->blinding = NULL;
137    }
138    rsa->flags &= ~RSA_FLAG_BLINDING;
139    rsa->flags |= RSA_FLAG_NO_BLINDING;
140}
141
142int RSA_blinding_on(RSA *rsa, BN_CTX *ctx)
143{
144    int ret = 0;
145
146    if (rsa->blinding != NULL)
147        RSA_blinding_off(rsa);
148
149    rsa->blinding = RSA_setup_blinding(rsa, ctx);
150    if (rsa->blinding == NULL)
151        goto err;
152
153    rsa->flags |= RSA_FLAG_BLINDING;
154    rsa->flags &= ~RSA_FLAG_NO_BLINDING;
155    ret = 1;
156 err:
157    return (ret);
158}
159
160static BIGNUM *rsa_get_public_exp(const BIGNUM *d, const BIGNUM *p,
161                                  const BIGNUM *q, BN_CTX *ctx)
162{
163    BIGNUM *ret = NULL, *r0, *r1, *r2;
164
165    if (d == NULL || p == NULL || q == NULL)
166        return NULL;
167
168    BN_CTX_start(ctx);
169    r0 = BN_CTX_get(ctx);
170    r1 = BN_CTX_get(ctx);
171    r2 = BN_CTX_get(ctx);
172    if (r2 == NULL)
173        goto err;
174
175    if (!BN_sub(r1, p, BN_value_one()))
176        goto err;
177    if (!BN_sub(r2, q, BN_value_one()))
178        goto err;
179    if (!BN_mul(r0, r1, r2, ctx))
180        goto err;
181
182    ret = BN_mod_inverse(NULL, d, r0, ctx);
183 err:
184    BN_CTX_end(ctx);
185    return ret;
186}
187
188BN_BLINDING *RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx)
189{
190    BIGNUM local_n;
191    BIGNUM *e, *n;
192    BN_CTX *ctx;
193    BN_BLINDING *ret = NULL;
194
195    if (in_ctx == NULL) {
196        if ((ctx = BN_CTX_new()) == NULL)
197            return 0;
198    } else
199        ctx = in_ctx;
200
201    BN_CTX_start(ctx);
202    e = BN_CTX_get(ctx);
203    if (e == NULL) {
204        RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_MALLOC_FAILURE);
205        goto err;
206    }
207
208    if (rsa->e == NULL) {
209        e = rsa_get_public_exp(rsa->d, rsa->p, rsa->q, ctx);
210        if (e == NULL) {
211            RSAerr(RSA_F_RSA_SETUP_BLINDING, RSA_R_NO_PUBLIC_EXPONENT);
212            goto err;
213        }
214    } else
215        e = rsa->e;
216
217    if ((RAND_status() == 0) && rsa->d != NULL && rsa->d->d != NULL) {
218        /*
219         * if PRNG is not properly seeded, resort to secret exponent as
220         * unpredictable seed
221         */
222        RAND_add(rsa->d->d, rsa->d->dmax * sizeof(rsa->d->d[0]), 0.0);
223    }
224
225    if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
226        /* Set BN_FLG_CONSTTIME flag */
227        n = &local_n;
228        BN_with_flags(n, rsa->n, BN_FLG_CONSTTIME);
229    } else
230        n = rsa->n;
231
232    ret = BN_BLINDING_create_param(NULL, e, n, ctx,
233                                   rsa->meth->bn_mod_exp, rsa->_method_mod_n);
234    if (ret == NULL) {
235        RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_BN_LIB);
236        goto err;
237    }
238    CRYPTO_THREADID_current(BN_BLINDING_thread_id(ret));
239 err:
240    BN_CTX_end(ctx);
241    if (in_ctx == NULL)
242        BN_CTX_free(ctx);
243    if (rsa->e == NULL)
244        BN_free(e);
245
246    return ret;
247}
248