1 /* crypto/dsa/dsa_key.c */ 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 #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 #ifndef OPENSSL_FIPS 68 69 static int dsa_builtin_keygen(DSA *dsa); 70 71 int DSA_generate_key(DSA *dsa) 72 { 73 if(dsa->meth->dsa_keygen) 74 return dsa->meth->dsa_keygen(dsa); 75 return dsa_builtin_keygen(dsa); 76 } 77 78 static int dsa_builtin_keygen(DSA *dsa) 79 { 80 int ok=0; 81 BN_CTX *ctx=NULL; 82 BIGNUM *pub_key=NULL,*priv_key=NULL; 83 84 if ((ctx=BN_CTX_new()) == NULL) goto err; 85 86 if (dsa->priv_key == NULL) 87 { 88 if ((priv_key=BN_new()) == NULL) goto err; 89 } 90 else 91 priv_key=dsa->priv_key; 92 93 do 94 if (!BN_rand_range(priv_key,dsa->q)) goto err; 95 while (BN_is_zero(priv_key)); 96 97 if (dsa->pub_key == NULL) 98 { 99 if ((pub_key=BN_new()) == NULL) goto err; 100 } 101 else 102 pub_key=dsa->pub_key; 103 104 { 105 BIGNUM local_prk; 106 BIGNUM *prk; 107 108 if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0) 109 { 110 BN_init(&local_prk); 111 prk = &local_prk; 112 BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME); 113 } 114 else 115 prk = priv_key; 116 117 if (!BN_mod_exp(pub_key,dsa->g,prk,dsa->p,ctx)) goto err; 118 } 119 120 dsa->priv_key=priv_key; 121 dsa->pub_key=pub_key; 122 ok=1; 123 124 err: 125 if ((pub_key != NULL) && (dsa->pub_key == NULL)) BN_free(pub_key); 126 if ((priv_key != NULL) && (dsa->priv_key == NULL)) BN_free(priv_key); 127 if (ctx != NULL) BN_CTX_free(ctx); 128 return(ok); 129 } 130 #endif 131 132 #endif 133