1 /* crypto/dsa/dsa_key.c */ 2 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com) 3 * All rights reserved. 4 * 5 * This package is an SSL implementation written 6 * by Eric Young (eay (at) 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 (at) 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 (at) 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 (at) 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 #include <time.h> 61 #include "cryptlib.h" 62 #ifndef OPENSSL_NO_SHA 63 #include <openssl/bn.h> 64 #include <openssl/dsa.h> 65 #include <openssl/rand.h> 66 67 static int dsa_builtin_keygen(DSA *dsa); 68 69 int DSA_generate_key(DSA *dsa) 70 { 71 if(dsa->meth->dsa_keygen) 72 return dsa->meth->dsa_keygen(dsa); 73 return dsa_builtin_keygen(dsa); 74 } 75 76 static int dsa_builtin_keygen(DSA *dsa) 77 { 78 int ok=0; 79 BN_CTX *ctx=NULL; 80 BIGNUM *pub_key=NULL,*priv_key=NULL; 81 82 if ((ctx=BN_CTX_new()) == NULL) goto err; 83 84 if (dsa->priv_key == NULL) 85 { 86 if ((priv_key=BN_new()) == NULL) goto err; 87 } 88 else 89 priv_key=dsa->priv_key; 90 91 do 92 if (!BN_rand_range(priv_key,dsa->q)) goto err; 93 while (BN_is_zero(priv_key)); 94 95 if (dsa->pub_key == NULL) 96 { 97 if ((pub_key=BN_new()) == NULL) goto err; 98 } 99 else 100 pub_key=dsa->pub_key; 101 102 { 103 BIGNUM local_prk; 104 BIGNUM *prk; 105 106 if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0) 107 { 108 BN_init(&local_prk); 109 prk = &local_prk; 110 BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME); 111 } 112 else 113 prk = priv_key; 114 115 if (!BN_mod_exp(pub_key,dsa->g,prk,dsa->p,ctx)) goto err; 116 } 117 118 dsa->priv_key=priv_key; 119 dsa->pub_key=pub_key; 120 ok=1; 121 122 err: 123 if ((pub_key != NULL) && (dsa->pub_key == NULL)) BN_free(pub_key); 124 if ((priv_key != NULL) && (dsa->priv_key == NULL)) BN_free(priv_key); 125 if (ctx != NULL) BN_CTX_free(ctx); 126 return(ok); 127 } 128 #endif 129
