1 /* $OpenBSD: rsa_crpt.c,v 1.15 2016/06/30 02:02:06 bcook 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 #ifndef OPENSSL_NO_ENGINE 70 #include <openssl/engine.h> 71 #endif 72 73 int 74 RSA_size(const RSA *r) 75 { 76 return BN_num_bytes(r->n); 77 } 78 79 int 80 RSA_public_encrypt(int flen, const unsigned char *from, unsigned char *to, 81 RSA *rsa, int padding) 82 { 83 return rsa->meth->rsa_pub_enc(flen, from, to, rsa, padding); 84 } 85 86 int 87 RSA_private_encrypt(int flen, const unsigned char *from, unsigned char *to, 88 RSA *rsa, int padding) 89 { 90 return rsa->meth->rsa_priv_enc(flen, from, to, rsa, padding); 91 } 92 93 int 94 RSA_private_decrypt(int flen, const unsigned char *from, unsigned char *to, 95 RSA *rsa, int padding) 96 { 97 return rsa->meth->rsa_priv_dec(flen, from, to, rsa, padding); 98 } 99 100 int 101 RSA_public_decrypt(int flen, const unsigned char *from, unsigned char *to, 102 RSA *rsa, int padding) 103 { 104 return rsa->meth->rsa_pub_dec(flen, from, to, rsa, padding); 105 } 106 107 int 108 RSA_flags(const RSA *r) 109 { 110 return r == NULL ? 0 : r->meth->flags; 111 } 112 113 void 114 RSA_blinding_off(RSA *rsa) 115 { 116 BN_BLINDING_free(rsa->blinding); 117 rsa->blinding = NULL; 118 rsa->flags |= RSA_FLAG_NO_BLINDING; 119 } 120 121 int 122 RSA_blinding_on(RSA *rsa, BN_CTX *ctx) 123 { 124 int ret = 0; 125 126 if (rsa->blinding != NULL) 127 RSA_blinding_off(rsa); 128 129 rsa->blinding = RSA_setup_blinding(rsa, ctx); 130 if (rsa->blinding == NULL) 131 goto err; 132 133 rsa->flags &= ~RSA_FLAG_NO_BLINDING; 134 ret = 1; 135 err: 136 return (ret); 137 } 138 139 static BIGNUM * 140 rsa_get_public_exp(const BIGNUM *d, const BIGNUM *p, const BIGNUM *q, 141 BN_CTX *ctx) 142 { 143 BIGNUM *ret = NULL, *r0, *r1, *r2; 144 145 if (d == NULL || p == NULL || q == NULL) 146 return NULL; 147 148 BN_CTX_start(ctx); 149 if ((r0 = BN_CTX_get(ctx)) == NULL) 150 goto err; 151 if ((r1 = BN_CTX_get(ctx)) == NULL) 152 goto err; 153 if ((r2 = BN_CTX_get(ctx)) == NULL) 154 goto err; 155 156 if (!BN_sub(r1, p, BN_value_one())) 157 goto err; 158 if (!BN_sub(r2, q, BN_value_one())) 159 goto err; 160 if (!BN_mul(r0, r1, r2, ctx)) 161 goto err; 162 163 ret = BN_mod_inverse(NULL, d, r0, ctx); 164 err: 165 BN_CTX_end(ctx); 166 return ret; 167 } 168 169 BN_BLINDING * 170 RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx) 171 { 172 BIGNUM *e; 173 BIGNUM n; 174 BN_CTX *ctx; 175 BN_BLINDING *ret = NULL; 176 177 if (in_ctx == NULL) { 178 if ((ctx = BN_CTX_new()) == NULL) 179 return 0; 180 } else 181 ctx = in_ctx; 182 183 BN_CTX_start(ctx); 184 185 if (rsa->e == NULL) { 186 e = rsa_get_public_exp(rsa->d, rsa->p, rsa->q, ctx); 187 if (e == NULL) { 188 RSAerr(RSA_F_RSA_SETUP_BLINDING, 189 RSA_R_NO_PUBLIC_EXPONENT); 190 goto err; 191 } 192 } else 193 e = rsa->e; 194 195 BN_init(&n); 196 BN_with_flags(&n, rsa->n, BN_FLG_CONSTTIME); 197 198 ret = BN_BLINDING_create_param(NULL, e, &n, ctx, rsa->meth->bn_mod_exp, 199 rsa->_method_mod_n); 200 201 if (ret == NULL) { 202 RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_BN_LIB); 203 goto err; 204 } 205 CRYPTO_THREADID_current(BN_BLINDING_thread_id(ret)); 206 err: 207 BN_CTX_end(ctx); 208 if (in_ctx == NULL) 209 BN_CTX_free(ctx); 210 if (rsa->e == NULL) 211 BN_free(e); 212 213 return ret; 214 } 215