1 /* $OpenBSD: rsa_crpt.c,v 1.20 2022/01/07 09:55:32 tb Exp $ */
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
61 #include <openssl/opensslconf.h>
62
63 #include <openssl/bn.h>
64 #include <openssl/crypto.h>
65 #include <openssl/err.h>
66 #include <openssl/lhash.h>
67 #include <openssl/rsa.h>
68
69 #include "bn_lcl.h"
70 #include "rsa_locl.h"
71
72 #ifndef OPENSSL_NO_ENGINE
73 #include <openssl/engine.h>
74 #endif
75
76 int
RSA_bits(const RSA * r)77 RSA_bits(const RSA *r)
78 {
79 return BN_num_bits(r->n);
80 }
81
82 int
RSA_size(const RSA * r)83 RSA_size(const RSA *r)
84 {
85 return BN_num_bytes(r->n);
86 }
87
88 int
RSA_public_encrypt(int flen,const unsigned char * from,unsigned char * to,RSA * rsa,int padding)89 RSA_public_encrypt(int flen, const unsigned char *from, unsigned char *to,
90 RSA *rsa, int padding)
91 {
92 return rsa->meth->rsa_pub_enc(flen, from, to, rsa, padding);
93 }
94
95 int
RSA_private_encrypt(int flen,const unsigned char * from,unsigned char * to,RSA * rsa,int padding)96 RSA_private_encrypt(int flen, const unsigned char *from, unsigned char *to,
97 RSA *rsa, int padding)
98 {
99 return rsa->meth->rsa_priv_enc(flen, from, to, rsa, padding);
100 }
101
102 int
RSA_private_decrypt(int flen,const unsigned char * from,unsigned char * to,RSA * rsa,int padding)103 RSA_private_decrypt(int flen, const unsigned char *from, unsigned char *to,
104 RSA *rsa, int padding)
105 {
106 return rsa->meth->rsa_priv_dec(flen, from, to, rsa, padding);
107 }
108
109 int
RSA_public_decrypt(int flen,const unsigned char * from,unsigned char * to,RSA * rsa,int padding)110 RSA_public_decrypt(int flen, const unsigned char *from, unsigned char *to,
111 RSA *rsa, int padding)
112 {
113 return rsa->meth->rsa_pub_dec(flen, from, to, rsa, padding);
114 }
115
116 int
RSA_flags(const RSA * r)117 RSA_flags(const RSA *r)
118 {
119 return r == NULL ? 0 : r->meth->flags;
120 }
121
122 void
RSA_blinding_off(RSA * rsa)123 RSA_blinding_off(RSA *rsa)
124 {
125 BN_BLINDING_free(rsa->blinding);
126 rsa->blinding = NULL;
127 rsa->flags |= RSA_FLAG_NO_BLINDING;
128 }
129
130 int
RSA_blinding_on(RSA * rsa,BN_CTX * ctx)131 RSA_blinding_on(RSA *rsa, BN_CTX *ctx)
132 {
133 int ret = 0;
134
135 if (rsa->blinding != NULL)
136 RSA_blinding_off(rsa);
137
138 rsa->blinding = RSA_setup_blinding(rsa, ctx);
139 if (rsa->blinding == NULL)
140 goto err;
141
142 rsa->flags &= ~RSA_FLAG_NO_BLINDING;
143 ret = 1;
144 err:
145 return (ret);
146 }
147
148 static BIGNUM *
rsa_get_public_exp(const BIGNUM * d,const BIGNUM * p,const BIGNUM * q,BN_CTX * ctx)149 rsa_get_public_exp(const BIGNUM *d, const BIGNUM *p, const BIGNUM *q,
150 BN_CTX *ctx)
151 {
152 BIGNUM *ret = NULL, *r0, *r1, *r2;
153
154 if (d == NULL || p == NULL || q == NULL)
155 return NULL;
156
157 BN_CTX_start(ctx);
158 if ((r0 = BN_CTX_get(ctx)) == NULL)
159 goto err;
160 if ((r1 = BN_CTX_get(ctx)) == NULL)
161 goto err;
162 if ((r2 = BN_CTX_get(ctx)) == NULL)
163 goto err;
164
165 if (!BN_sub(r1, p, BN_value_one()))
166 goto err;
167 if (!BN_sub(r2, q, BN_value_one()))
168 goto err;
169 if (!BN_mul(r0, r1, r2, ctx))
170 goto err;
171
172 ret = BN_mod_inverse_ct(NULL, d, r0, ctx);
173 err:
174 BN_CTX_end(ctx);
175 return ret;
176 }
177
178 BN_BLINDING *
RSA_setup_blinding(RSA * rsa,BN_CTX * in_ctx)179 RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx)
180 {
181 BIGNUM *e;
182 BIGNUM n;
183 BN_CTX *ctx;
184 BN_BLINDING *ret = NULL;
185
186 if (in_ctx == NULL) {
187 if ((ctx = BN_CTX_new()) == NULL)
188 return 0;
189 } else
190 ctx = in_ctx;
191
192 BN_CTX_start(ctx);
193
194 if (rsa->e == NULL) {
195 e = rsa_get_public_exp(rsa->d, rsa->p, rsa->q, ctx);
196 if (e == NULL) {
197 RSAerror(RSA_R_NO_PUBLIC_EXPONENT);
198 goto err;
199 }
200 } else
201 e = rsa->e;
202
203 BN_init(&n);
204 BN_with_flags(&n, rsa->n, BN_FLG_CONSTTIME);
205
206 ret = BN_BLINDING_create_param(NULL, e, &n, ctx, rsa->meth->bn_mod_exp,
207 rsa->_method_mod_n);
208
209 if (ret == NULL) {
210 RSAerror(ERR_R_BN_LIB);
211 goto err;
212 }
213 CRYPTO_THREADID_current(BN_BLINDING_thread_id(ret));
214 err:
215 BN_CTX_end(ctx);
216 if (in_ctx == NULL)
217 BN_CTX_free(ctx);
218 if (rsa->e == NULL)
219 BN_free(e);
220
221 return ret;
222 }
223