1 /* $OpenBSD: rsa_crpt.c,v 1.19 2018/02/18 12:52:13 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 71 #ifndef OPENSSL_NO_ENGINE 72 #include <openssl/engine.h> 73 #endif 74 75 int 76 RSA_bits(const RSA *r) 77 { 78 return BN_num_bits(r->n); 79 } 80 81 int 82 RSA_size(const RSA *r) 83 { 84 return BN_num_bytes(r->n); 85 } 86 87 int 88 RSA_public_encrypt(int flen, const unsigned char *from, unsigned char *to, 89 RSA *rsa, int padding) 90 { 91 return rsa->meth->rsa_pub_enc(flen, from, to, rsa, padding); 92 } 93 94 int 95 RSA_private_encrypt(int flen, const unsigned char *from, unsigned char *to, 96 RSA *rsa, int padding) 97 { 98 return rsa->meth->rsa_priv_enc(flen, from, to, rsa, padding); 99 } 100 101 int 102 RSA_private_decrypt(int flen, const unsigned char *from, unsigned char *to, 103 RSA *rsa, int padding) 104 { 105 return rsa->meth->rsa_priv_dec(flen, from, to, rsa, padding); 106 } 107 108 int 109 RSA_public_decrypt(int flen, const unsigned char *from, unsigned char *to, 110 RSA *rsa, int padding) 111 { 112 return rsa->meth->rsa_pub_dec(flen, from, to, rsa, padding); 113 } 114 115 int 116 RSA_flags(const RSA *r) 117 { 118 return r == NULL ? 0 : r->meth->flags; 119 } 120 121 void 122 RSA_blinding_off(RSA *rsa) 123 { 124 BN_BLINDING_free(rsa->blinding); 125 rsa->blinding = NULL; 126 rsa->flags |= RSA_FLAG_NO_BLINDING; 127 } 128 129 int 130 RSA_blinding_on(RSA *rsa, BN_CTX *ctx) 131 { 132 int ret = 0; 133 134 if (rsa->blinding != NULL) 135 RSA_blinding_off(rsa); 136 137 rsa->blinding = RSA_setup_blinding(rsa, ctx); 138 if (rsa->blinding == NULL) 139 goto err; 140 141 rsa->flags &= ~RSA_FLAG_NO_BLINDING; 142 ret = 1; 143 err: 144 return (ret); 145 } 146 147 static BIGNUM * 148 rsa_get_public_exp(const BIGNUM *d, const BIGNUM *p, const BIGNUM *q, 149 BN_CTX *ctx) 150 { 151 BIGNUM *ret = NULL, *r0, *r1, *r2; 152 153 if (d == NULL || p == NULL || q == NULL) 154 return NULL; 155 156 BN_CTX_start(ctx); 157 if ((r0 = BN_CTX_get(ctx)) == NULL) 158 goto err; 159 if ((r1 = BN_CTX_get(ctx)) == NULL) 160 goto err; 161 if ((r2 = BN_CTX_get(ctx)) == NULL) 162 goto err; 163 164 if (!BN_sub(r1, p, BN_value_one())) 165 goto err; 166 if (!BN_sub(r2, q, BN_value_one())) 167 goto err; 168 if (!BN_mul(r0, r1, r2, ctx)) 169 goto err; 170 171 ret = BN_mod_inverse_ct(NULL, d, r0, ctx); 172 err: 173 BN_CTX_end(ctx); 174 return ret; 175 } 176 177 BN_BLINDING * 178 RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx) 179 { 180 BIGNUM *e; 181 BIGNUM n; 182 BN_CTX *ctx; 183 BN_BLINDING *ret = NULL; 184 185 if (in_ctx == NULL) { 186 if ((ctx = BN_CTX_new()) == NULL) 187 return 0; 188 } else 189 ctx = in_ctx; 190 191 BN_CTX_start(ctx); 192 193 if (rsa->e == NULL) { 194 e = rsa_get_public_exp(rsa->d, rsa->p, rsa->q, ctx); 195 if (e == NULL) { 196 RSAerror(RSA_R_NO_PUBLIC_EXPONENT); 197 goto err; 198 } 199 } else 200 e = rsa->e; 201 202 BN_init(&n); 203 BN_with_flags(&n, rsa->n, BN_FLG_CONSTTIME); 204 205 ret = BN_BLINDING_create_param(NULL, e, &n, ctx, rsa->meth->bn_mod_exp, 206 rsa->_method_mod_n); 207 208 if (ret == NULL) { 209 RSAerror(ERR_R_BN_LIB); 210 goto err; 211 } 212 CRYPTO_THREADID_current(BN_BLINDING_thread_id(ret)); 213 err: 214 BN_CTX_end(ctx); 215 if (in_ctx == NULL) 216 BN_CTX_free(ctx); 217 if (rsa->e == NULL) 218 BN_free(e); 219 220 return ret; 221 } 222