1*0Sstevel@tonic-gate /* crypto/dh/dh_key.c */ 2*0Sstevel@tonic-gate /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 3*0Sstevel@tonic-gate * All rights reserved. 4*0Sstevel@tonic-gate * 5*0Sstevel@tonic-gate * This package is an SSL implementation written 6*0Sstevel@tonic-gate * by Eric Young (eay@cryptsoft.com). 7*0Sstevel@tonic-gate * The implementation was written so as to conform with Netscapes SSL. 8*0Sstevel@tonic-gate * 9*0Sstevel@tonic-gate * This library is free for commercial and non-commercial use as long as 10*0Sstevel@tonic-gate * the following conditions are aheared to. The following conditions 11*0Sstevel@tonic-gate * apply to all code found in this distribution, be it the RC4, RSA, 12*0Sstevel@tonic-gate * lhash, DES, etc., code; not just the SSL code. The SSL documentation 13*0Sstevel@tonic-gate * included with this distribution is covered by the same copyright terms 14*0Sstevel@tonic-gate * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15*0Sstevel@tonic-gate * 16*0Sstevel@tonic-gate * Copyright remains Eric Young's, and as such any Copyright notices in 17*0Sstevel@tonic-gate * the code are not to be removed. 18*0Sstevel@tonic-gate * If this package is used in a product, Eric Young should be given attribution 19*0Sstevel@tonic-gate * as the author of the parts of the library used. 20*0Sstevel@tonic-gate * This can be in the form of a textual message at program startup or 21*0Sstevel@tonic-gate * in documentation (online or textual) provided with the package. 22*0Sstevel@tonic-gate * 23*0Sstevel@tonic-gate * Redistribution and use in source and binary forms, with or without 24*0Sstevel@tonic-gate * modification, are permitted provided that the following conditions 25*0Sstevel@tonic-gate * are met: 26*0Sstevel@tonic-gate * 1. Redistributions of source code must retain the copyright 27*0Sstevel@tonic-gate * notice, this list of conditions and the following disclaimer. 28*0Sstevel@tonic-gate * 2. Redistributions in binary form must reproduce the above copyright 29*0Sstevel@tonic-gate * notice, this list of conditions and the following disclaimer in the 30*0Sstevel@tonic-gate * documentation and/or other materials provided with the distribution. 31*0Sstevel@tonic-gate * 3. All advertising materials mentioning features or use of this software 32*0Sstevel@tonic-gate * must display the following acknowledgement: 33*0Sstevel@tonic-gate * "This product includes cryptographic software written by 34*0Sstevel@tonic-gate * Eric Young (eay@cryptsoft.com)" 35*0Sstevel@tonic-gate * The word 'cryptographic' can be left out if the rouines from the library 36*0Sstevel@tonic-gate * being used are not cryptographic related :-). 37*0Sstevel@tonic-gate * 4. If you include any Windows specific code (or a derivative thereof) from 38*0Sstevel@tonic-gate * the apps directory (application code) you must include an acknowledgement: 39*0Sstevel@tonic-gate * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40*0Sstevel@tonic-gate * 41*0Sstevel@tonic-gate * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 42*0Sstevel@tonic-gate * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 43*0Sstevel@tonic-gate * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 44*0Sstevel@tonic-gate * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 45*0Sstevel@tonic-gate * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 46*0Sstevel@tonic-gate * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 47*0Sstevel@tonic-gate * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48*0Sstevel@tonic-gate * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 49*0Sstevel@tonic-gate * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 50*0Sstevel@tonic-gate * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 51*0Sstevel@tonic-gate * SUCH DAMAGE. 52*0Sstevel@tonic-gate * 53*0Sstevel@tonic-gate * The licence and distribution terms for any publically available version or 54*0Sstevel@tonic-gate * derivative of this code cannot be changed. i.e. this code cannot simply be 55*0Sstevel@tonic-gate * copied and put under another distribution licence 56*0Sstevel@tonic-gate * [including the GNU Public Licence.] 57*0Sstevel@tonic-gate */ 58*0Sstevel@tonic-gate 59*0Sstevel@tonic-gate #include <stdio.h> 60*0Sstevel@tonic-gate #include "cryptlib.h" 61*0Sstevel@tonic-gate #include <openssl/bn.h> 62*0Sstevel@tonic-gate #include <openssl/rand.h> 63*0Sstevel@tonic-gate #include <openssl/dh.h> 64*0Sstevel@tonic-gate 65*0Sstevel@tonic-gate static int generate_key(DH *dh); 66*0Sstevel@tonic-gate static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh); 67*0Sstevel@tonic-gate static int dh_bn_mod_exp(const DH *dh, BIGNUM *r, 68*0Sstevel@tonic-gate const BIGNUM *a, const BIGNUM *p, 69*0Sstevel@tonic-gate const BIGNUM *m, BN_CTX *ctx, 70*0Sstevel@tonic-gate BN_MONT_CTX *m_ctx); 71*0Sstevel@tonic-gate static int dh_init(DH *dh); 72*0Sstevel@tonic-gate static int dh_finish(DH *dh); 73*0Sstevel@tonic-gate 74*0Sstevel@tonic-gate int DH_generate_key(DH *dh) 75*0Sstevel@tonic-gate { 76*0Sstevel@tonic-gate return dh->meth->generate_key(dh); 77*0Sstevel@tonic-gate } 78*0Sstevel@tonic-gate 79*0Sstevel@tonic-gate int DH_compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh) 80*0Sstevel@tonic-gate { 81*0Sstevel@tonic-gate return dh->meth->compute_key(key, pub_key, dh); 82*0Sstevel@tonic-gate } 83*0Sstevel@tonic-gate 84*0Sstevel@tonic-gate static DH_METHOD dh_ossl = { 85*0Sstevel@tonic-gate "OpenSSL DH Method", 86*0Sstevel@tonic-gate generate_key, 87*0Sstevel@tonic-gate compute_key, 88*0Sstevel@tonic-gate dh_bn_mod_exp, 89*0Sstevel@tonic-gate dh_init, 90*0Sstevel@tonic-gate dh_finish, 91*0Sstevel@tonic-gate 0, 92*0Sstevel@tonic-gate NULL 93*0Sstevel@tonic-gate }; 94*0Sstevel@tonic-gate 95*0Sstevel@tonic-gate const DH_METHOD *DH_OpenSSL(void) 96*0Sstevel@tonic-gate { 97*0Sstevel@tonic-gate return &dh_ossl; 98*0Sstevel@tonic-gate } 99*0Sstevel@tonic-gate 100*0Sstevel@tonic-gate static int generate_key(DH *dh) 101*0Sstevel@tonic-gate { 102*0Sstevel@tonic-gate int ok=0; 103*0Sstevel@tonic-gate int generate_new_key=0; 104*0Sstevel@tonic-gate unsigned l; 105*0Sstevel@tonic-gate BN_CTX *ctx; 106*0Sstevel@tonic-gate BN_MONT_CTX *mont; 107*0Sstevel@tonic-gate BIGNUM *pub_key=NULL,*priv_key=NULL; 108*0Sstevel@tonic-gate 109*0Sstevel@tonic-gate ctx = BN_CTX_new(); 110*0Sstevel@tonic-gate if (ctx == NULL) goto err; 111*0Sstevel@tonic-gate 112*0Sstevel@tonic-gate if (dh->priv_key == NULL) 113*0Sstevel@tonic-gate { 114*0Sstevel@tonic-gate priv_key=BN_new(); 115*0Sstevel@tonic-gate if (priv_key == NULL) goto err; 116*0Sstevel@tonic-gate generate_new_key=1; 117*0Sstevel@tonic-gate } 118*0Sstevel@tonic-gate else 119*0Sstevel@tonic-gate priv_key=dh->priv_key; 120*0Sstevel@tonic-gate 121*0Sstevel@tonic-gate if (dh->pub_key == NULL) 122*0Sstevel@tonic-gate { 123*0Sstevel@tonic-gate pub_key=BN_new(); 124*0Sstevel@tonic-gate if (pub_key == NULL) goto err; 125*0Sstevel@tonic-gate } 126*0Sstevel@tonic-gate else 127*0Sstevel@tonic-gate pub_key=dh->pub_key; 128*0Sstevel@tonic-gate 129*0Sstevel@tonic-gate if ((dh->method_mont_p == NULL) && (dh->flags & DH_FLAG_CACHE_MONT_P)) 130*0Sstevel@tonic-gate { 131*0Sstevel@tonic-gate if ((dh->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL) 132*0Sstevel@tonic-gate if (!BN_MONT_CTX_set((BN_MONT_CTX *)dh->method_mont_p, 133*0Sstevel@tonic-gate dh->p,ctx)) goto err; 134*0Sstevel@tonic-gate } 135*0Sstevel@tonic-gate mont=(BN_MONT_CTX *)dh->method_mont_p; 136*0Sstevel@tonic-gate 137*0Sstevel@tonic-gate if (generate_new_key) 138*0Sstevel@tonic-gate { 139*0Sstevel@tonic-gate l = dh->length ? dh->length : BN_num_bits(dh->p)-1; /* secret exponent length */ 140*0Sstevel@tonic-gate if (!BN_rand(priv_key, l, 0, 0)) goto err; 141*0Sstevel@tonic-gate } 142*0Sstevel@tonic-gate if (!dh->meth->bn_mod_exp(dh, pub_key, dh->g, priv_key,dh->p,ctx,mont)) 143*0Sstevel@tonic-gate goto err; 144*0Sstevel@tonic-gate 145*0Sstevel@tonic-gate dh->pub_key=pub_key; 146*0Sstevel@tonic-gate dh->priv_key=priv_key; 147*0Sstevel@tonic-gate ok=1; 148*0Sstevel@tonic-gate err: 149*0Sstevel@tonic-gate if (ok != 1) 150*0Sstevel@tonic-gate DHerr(DH_F_DH_GENERATE_KEY,ERR_R_BN_LIB); 151*0Sstevel@tonic-gate 152*0Sstevel@tonic-gate if ((pub_key != NULL) && (dh->pub_key == NULL)) BN_free(pub_key); 153*0Sstevel@tonic-gate if ((priv_key != NULL) && (dh->priv_key == NULL)) BN_free(priv_key); 154*0Sstevel@tonic-gate BN_CTX_free(ctx); 155*0Sstevel@tonic-gate return(ok); 156*0Sstevel@tonic-gate } 157*0Sstevel@tonic-gate 158*0Sstevel@tonic-gate static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh) 159*0Sstevel@tonic-gate { 160*0Sstevel@tonic-gate BN_CTX *ctx; 161*0Sstevel@tonic-gate BN_MONT_CTX *mont; 162*0Sstevel@tonic-gate BIGNUM *tmp; 163*0Sstevel@tonic-gate int ret= -1; 164*0Sstevel@tonic-gate 165*0Sstevel@tonic-gate ctx = BN_CTX_new(); 166*0Sstevel@tonic-gate if (ctx == NULL) goto err; 167*0Sstevel@tonic-gate BN_CTX_start(ctx); 168*0Sstevel@tonic-gate tmp = BN_CTX_get(ctx); 169*0Sstevel@tonic-gate 170*0Sstevel@tonic-gate if (dh->priv_key == NULL) 171*0Sstevel@tonic-gate { 172*0Sstevel@tonic-gate DHerr(DH_F_DH_COMPUTE_KEY,DH_R_NO_PRIVATE_VALUE); 173*0Sstevel@tonic-gate goto err; 174*0Sstevel@tonic-gate } 175*0Sstevel@tonic-gate if ((dh->method_mont_p == NULL) && (dh->flags & DH_FLAG_CACHE_MONT_P)) 176*0Sstevel@tonic-gate { 177*0Sstevel@tonic-gate if ((dh->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL) 178*0Sstevel@tonic-gate if (!BN_MONT_CTX_set((BN_MONT_CTX *)dh->method_mont_p, 179*0Sstevel@tonic-gate dh->p,ctx)) goto err; 180*0Sstevel@tonic-gate } 181*0Sstevel@tonic-gate 182*0Sstevel@tonic-gate mont=(BN_MONT_CTX *)dh->method_mont_p; 183*0Sstevel@tonic-gate if (!dh->meth->bn_mod_exp(dh, tmp, pub_key, dh->priv_key,dh->p,ctx,mont)) 184*0Sstevel@tonic-gate { 185*0Sstevel@tonic-gate DHerr(DH_F_DH_COMPUTE_KEY,ERR_R_BN_LIB); 186*0Sstevel@tonic-gate goto err; 187*0Sstevel@tonic-gate } 188*0Sstevel@tonic-gate 189*0Sstevel@tonic-gate ret=BN_bn2bin(tmp,key); 190*0Sstevel@tonic-gate err: 191*0Sstevel@tonic-gate BN_CTX_end(ctx); 192*0Sstevel@tonic-gate BN_CTX_free(ctx); 193*0Sstevel@tonic-gate return(ret); 194*0Sstevel@tonic-gate } 195*0Sstevel@tonic-gate 196*0Sstevel@tonic-gate static int dh_bn_mod_exp(const DH *dh, BIGNUM *r, 197*0Sstevel@tonic-gate const BIGNUM *a, const BIGNUM *p, 198*0Sstevel@tonic-gate const BIGNUM *m, BN_CTX *ctx, 199*0Sstevel@tonic-gate BN_MONT_CTX *m_ctx) 200*0Sstevel@tonic-gate { 201*0Sstevel@tonic-gate if (a->top == 1) 202*0Sstevel@tonic-gate { 203*0Sstevel@tonic-gate BN_ULONG A = a->d[0]; 204*0Sstevel@tonic-gate return BN_mod_exp_mont_word(r,A,p,m,ctx,m_ctx); 205*0Sstevel@tonic-gate } 206*0Sstevel@tonic-gate else 207*0Sstevel@tonic-gate return BN_mod_exp_mont(r,a,p,m,ctx,m_ctx); 208*0Sstevel@tonic-gate } 209*0Sstevel@tonic-gate 210*0Sstevel@tonic-gate 211*0Sstevel@tonic-gate static int dh_init(DH *dh) 212*0Sstevel@tonic-gate { 213*0Sstevel@tonic-gate dh->flags |= DH_FLAG_CACHE_MONT_P; 214*0Sstevel@tonic-gate return(1); 215*0Sstevel@tonic-gate } 216*0Sstevel@tonic-gate 217*0Sstevel@tonic-gate static int dh_finish(DH *dh) 218*0Sstevel@tonic-gate { 219*0Sstevel@tonic-gate if(dh->method_mont_p) 220*0Sstevel@tonic-gate BN_MONT_CTX_free((BN_MONT_CTX *)dh->method_mont_p); 221*0Sstevel@tonic-gate return(1); 222*0Sstevel@tonic-gate } 223