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 77 RSA_bits(const RSA *r) 78 { 79 return BN_num_bits(r->n); 80 } 81 82 int 83 RSA_size(const RSA *r) 84 { 85 return BN_num_bytes(r->n); 86 } 87 88 int 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 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 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 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 117 RSA_flags(const RSA *r) 118 { 119 return r == NULL ? 0 : r->meth->flags; 120 } 121 122 void 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 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 * 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 * 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