1/* 2 * Copyright (c) 2000-2002 Apple Computer, Inc. All Rights Reserved. 3 * 4 * The contents of this file constitute Original Code as defined in and are 5 * subject to the Apple Public Source License Version 1.2 (the 'License'). 6 * You may not use this file except in compliance with the License. Please obtain 7 * a copy of the License at http://www.apple.com/publicsource and read it before 8 * using this file. 9 * 10 * This Original Code and all software distributed under the License are 11 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS 12 * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT 13 * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR 14 * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the 15 * specific language governing rights and limitations under the License. 16 */ 17 18/* crypto/dh/dh_key.c */ 19/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 20 * All rights reserved. 21 * 22 * This package is an SSL implementation written 23 * by Eric Young (eay@cryptsoft.com). 24 * The implementation was written so as to conform with Netscapes SSL. 25 * 26 * This library is free for commercial and non-commercial use as long as 27 * the following conditions are aheared to. The following conditions 28 * apply to all code found in this distribution, be it the RC4, RSA, 29 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 30 * included with this distribution is covered by the same copyright terms 31 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 32 * 33 * Copyright remains Eric Young's, and as such any Copyright notices in 34 * the code are not to be removed. 35 * If this package is used in a product, Eric Young should be given attribution 36 * as the author of the parts of the library used. 37 * This can be in the form of a textual message at program startup or 38 * in documentation (online or textual) provided with the package. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 3. All advertising materials mentioning features or use of this software 49 * must display the following acknowledgement: 50 * "This product includes cryptographic software written by 51 * Eric Young (eay@cryptsoft.com)" 52 * The word 'cryptographic' can be left out if the rouines from the library 53 * being used are not cryptographic related :-). 54 * 4. If you include any Windows specific code (or a derivative thereof) from 55 * the apps directory (application code) you must include an acknowledgement: 56 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 57 * 58 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 59 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 60 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 61 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 62 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 63 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 64 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 65 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 66 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 67 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 68 * SUCH DAMAGE. 69 * 70 * The licence and distribution terms for any publically available version or 71 * derivative of this code cannot be changed. i.e. this code cannot simply be 72 * copied and put under another distribution licence 73 * [including the GNU Public Licence.] 74 */ 75 76#include <stdio.h> 77#include "cryptlib.h" 78#include <openssl/bn.h> 79#include <openssl/rand.h> 80#include <openssl/dh.h> 81 82static int generate_key(DH *dh); 83static int compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh); 84static int dh_bn_mod_exp(DH *dh, BIGNUM *r, BIGNUM *a, const BIGNUM *p, 85 const BIGNUM *m, BN_CTX *ctx, 86 BN_MONT_CTX *m_ctx); 87static int dh_init(DH *dh); 88static int dh_finish(DH *dh); 89 90int DH_generate_key(DH *dh) 91 { 92 return dh->meth->generate_key(dh); 93 } 94 95int DH_compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh) 96 { 97 return dh->meth->compute_key(key, pub_key, dh); 98 } 99 100static DH_METHOD dh_ossl = { 101"OpenSSL DH Method", 102generate_key, 103compute_key, 104dh_bn_mod_exp, 105dh_init, 106dh_finish, 1070, 108NULL 109}; 110 111DH_METHOD *DH_OpenSSL(void) 112{ 113 return &dh_ossl; 114} 115 116static int generate_key(DH *dh) 117 { 118 int ok=0; 119 BN_CTX ctx; 120 BN_MONT_CTX *mont; 121 BIGNUM *pub_key=NULL,*priv_key=NULL; 122 123 BN_CTX_init(&ctx); 124 125 if (dh->priv_key == NULL) 126 { 127 priv_key=BN_new(); 128 if (priv_key == NULL) goto err; 129 do 130 if (!BN_rand_range(priv_key, dh->p)) goto err; 131 while (BN_is_zero(priv_key)); 132 } 133 else 134 priv_key=dh->priv_key; 135 136 if (dh->pub_key == NULL) 137 { 138 pub_key=BN_new(); 139 if (pub_key == NULL) goto err; 140 } 141 else 142 pub_key=dh->pub_key; 143 144 if ((dh->method_mont_p == NULL) && (dh->flags & DH_FLAG_CACHE_MONT_P)) 145 { 146 if ((dh->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL) 147 if (!BN_MONT_CTX_set((BN_MONT_CTX *)dh->method_mont_p, 148 dh->p,&ctx)) goto err; 149 } 150 mont=(BN_MONT_CTX *)dh->method_mont_p; 151 152 if (!dh->meth->bn_mod_exp(dh, pub_key,dh->g,priv_key,dh->p,&ctx,mont)) 153 goto err; 154 155 dh->pub_key=pub_key; 156 dh->priv_key=priv_key; 157 ok=1; 158err: 159 if (ok != 1) 160 DHerr(DH_F_DH_GENERATE_KEY,ERR_R_BN_LIB); 161 162 if ((pub_key != NULL) && (dh->pub_key == NULL)) BN_free(pub_key); 163 if ((priv_key != NULL) && (dh->priv_key == NULL)) BN_free(priv_key); 164 BN_CTX_free(&ctx); 165 return(ok); 166 } 167 168static int compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh) 169 { 170 BN_CTX ctx; 171 BN_MONT_CTX *mont; 172 BIGNUM *tmp; 173 int ret= -1; 174 175 BN_CTX_init(&ctx); 176 BN_CTX_start(&ctx); 177 tmp = BN_CTX_get(&ctx); 178 179 if (dh->priv_key == NULL) 180 { 181 DHerr(DH_F_DH_COMPUTE_KEY,DH_R_NO_PRIVATE_VALUE); 182 goto err; 183 } 184 if ((dh->method_mont_p == NULL) && (dh->flags & DH_FLAG_CACHE_MONT_P)) 185 { 186 if ((dh->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL) 187 if (!BN_MONT_CTX_set((BN_MONT_CTX *)dh->method_mont_p, 188 dh->p,&ctx)) goto err; 189 } 190 191 mont=(BN_MONT_CTX *)dh->method_mont_p; 192 if (!dh->meth->bn_mod_exp(dh, tmp,pub_key,dh->priv_key,dh->p,&ctx,mont)) 193 { 194 DHerr(DH_F_DH_COMPUTE_KEY,ERR_R_BN_LIB); 195 goto err; 196 } 197 198 ret=BN_bn2bin(tmp,key); 199err: 200 BN_CTX_end(&ctx); 201 BN_CTX_free(&ctx); 202 return(ret); 203 } 204 205static int dh_bn_mod_exp(DH *dh, BIGNUM *r, BIGNUM *a, const BIGNUM *p, 206 const BIGNUM *m, BN_CTX *ctx, 207 BN_MONT_CTX *m_ctx) 208 { 209 if (a->top == 1) 210 { 211 BN_ULONG A = a->d[0]; 212 return BN_mod_exp_mont_word(r,A,p,m,ctx,m_ctx); 213 } 214 else 215 return BN_mod_exp_mont(r,a,p,m,ctx,m_ctx); 216 } 217 218 219static int dh_init(DH *dh) 220 { 221 dh->flags |= DH_FLAG_CACHE_MONT_P; 222 return(1); 223 } 224 225static int dh_finish(DH *dh) 226 { 227 if(dh->method_mont_p) 228 BN_MONT_CTX_free((BN_MONT_CTX *)dh->method_mont_p); 229 return(1); 230 } 231