1 /* $OpenBSD: dsa_lib.c,v 1.21 2014/07/12 16:03:37 miod 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 /* Original version from Steven Schoch <schoch@sheba.arc.nasa.gov> */ 60 61 #include <stdio.h> 62 63 #include <openssl/opensslconf.h> 64 65 #include <openssl/asn1.h> 66 #include <openssl/bn.h> 67 #include <openssl/dsa.h> 68 #include <openssl/err.h> 69 70 #ifndef OPENSSL_NO_DH 71 #include <openssl/dh.h> 72 #endif 73 #ifndef OPENSSL_NO_ENGINE 74 #include <openssl/engine.h> 75 #endif 76 77 static const DSA_METHOD *default_DSA_method = NULL; 78 79 void 80 DSA_set_default_method(const DSA_METHOD *meth) 81 { 82 default_DSA_method = meth; 83 } 84 85 const DSA_METHOD * 86 DSA_get_default_method(void) 87 { 88 if (!default_DSA_method) 89 default_DSA_method = DSA_OpenSSL(); 90 return default_DSA_method; 91 } 92 93 DSA * 94 DSA_new(void) 95 { 96 return DSA_new_method(NULL); 97 } 98 99 int 100 DSA_set_method(DSA *dsa, const DSA_METHOD *meth) 101 { 102 /* 103 * NB: The caller is specifically setting a method, so it's not up to us 104 * to deal with which ENGINE it comes from. 105 */ 106 const DSA_METHOD *mtmp; 107 mtmp = dsa->meth; 108 if (mtmp->finish) 109 mtmp->finish(dsa); 110 #ifndef OPENSSL_NO_ENGINE 111 if (dsa->engine) { 112 ENGINE_finish(dsa->engine); 113 dsa->engine = NULL; 114 } 115 #endif 116 dsa->meth = meth; 117 if (meth->init) 118 meth->init(dsa); 119 return 1; 120 } 121 122 DSA * 123 DSA_new_method(ENGINE *engine) 124 { 125 DSA *ret; 126 127 ret = malloc(sizeof(DSA)); 128 if (ret == NULL) { 129 DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_MALLOC_FAILURE); 130 return NULL; 131 } 132 ret->meth = DSA_get_default_method(); 133 #ifndef OPENSSL_NO_ENGINE 134 if (engine) { 135 if (!ENGINE_init(engine)) { 136 DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB); 137 free(ret); 138 return NULL; 139 } 140 ret->engine = engine; 141 } else 142 ret->engine = ENGINE_get_default_DSA(); 143 if (ret->engine) { 144 ret->meth = ENGINE_get_DSA(ret->engine); 145 if (!ret->meth) { 146 DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB); 147 ENGINE_finish(ret->engine); 148 free(ret); 149 return NULL; 150 } 151 } 152 #endif 153 154 ret->pad = 0; 155 ret->version = 0; 156 ret->write_params = 1; 157 ret->p = NULL; 158 ret->q = NULL; 159 ret->g = NULL; 160 161 ret->pub_key = NULL; 162 ret->priv_key = NULL; 163 164 ret->kinv = NULL; 165 ret->r = NULL; 166 ret->method_mont_p = NULL; 167 168 ret->references = 1; 169 ret->flags = ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW; 170 CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data); 171 if (ret->meth->init != NULL && !ret->meth->init(ret)) { 172 #ifndef OPENSSL_NO_ENGINE 173 if (ret->engine) 174 ENGINE_finish(ret->engine); 175 #endif 176 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data); 177 free(ret); 178 ret = NULL; 179 } 180 181 return ret; 182 } 183 184 void 185 DSA_free(DSA *r) 186 { 187 int i; 188 189 if (r == NULL) 190 return; 191 192 i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DSA); 193 if (i > 0) 194 return; 195 196 if (r->meth->finish) 197 r->meth->finish(r); 198 #ifndef OPENSSL_NO_ENGINE 199 if (r->engine) 200 ENGINE_finish(r->engine); 201 #endif 202 203 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data); 204 205 BN_clear_free(r->p); 206 BN_clear_free(r->q); 207 BN_clear_free(r->g); 208 BN_clear_free(r->pub_key); 209 BN_clear_free(r->priv_key); 210 BN_clear_free(r->kinv); 211 BN_clear_free(r->r); 212 free(r); 213 } 214 215 int 216 DSA_up_ref(DSA *r) 217 { 218 int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DSA); 219 return i > 1 ? 1 : 0; 220 } 221 222 int 223 DSA_size(const DSA *r) 224 { 225 int ret, i; 226 ASN1_INTEGER bs; 227 unsigned char buf[4]; /* 4 bytes looks really small. 228 However, i2d_ASN1_INTEGER() will not look 229 beyond the first byte, as long as the second 230 parameter is NULL. */ 231 232 i = BN_num_bits(r->q); 233 bs.length = (i + 7) / 8; 234 bs.data = buf; 235 bs.type = V_ASN1_INTEGER; 236 /* If the top bit is set the asn1 encoding is 1 larger. */ 237 buf[0] = 0xff; 238 239 i = i2d_ASN1_INTEGER(&bs, NULL); 240 i += i; /* r and s */ 241 ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE); 242 return ret; 243 } 244 245 int 246 DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func, 247 CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func) 248 { 249 return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DSA, argl, argp, 250 new_func, dup_func, free_func); 251 } 252 253 int 254 DSA_set_ex_data(DSA *d, int idx, void *arg) 255 { 256 return CRYPTO_set_ex_data(&d->ex_data, idx, arg); 257 } 258 259 void * 260 DSA_get_ex_data(DSA *d, int idx) 261 { 262 return CRYPTO_get_ex_data(&d->ex_data, idx); 263 } 264 265 #ifndef OPENSSL_NO_DH 266 DH * 267 DSA_dup_DH(const DSA *r) 268 { 269 /* 270 * DSA has p, q, g, optional pub_key, optional priv_key. 271 * DH has p, optional length, g, optional pub_key, optional priv_key, 272 * optional q. 273 */ 274 DH *ret = NULL; 275 276 if (r == NULL) 277 goto err; 278 ret = DH_new(); 279 if (ret == NULL) 280 goto err; 281 if (r->p != NULL) 282 if ((ret->p = BN_dup(r->p)) == NULL) 283 goto err; 284 if (r->q != NULL) { 285 ret->length = BN_num_bits(r->q); 286 if ((ret->q = BN_dup(r->q)) == NULL) 287 goto err; 288 } 289 if (r->g != NULL) 290 if ((ret->g = BN_dup(r->g)) == NULL) 291 goto err; 292 if (r->pub_key != NULL) 293 if ((ret->pub_key = BN_dup(r->pub_key)) == NULL) 294 goto err; 295 if (r->priv_key != NULL) 296 if ((ret->priv_key = BN_dup(r->priv_key)) == NULL) 297 goto err; 298 299 return ret; 300 301 err: 302 DH_free(ret); 303 return NULL; 304 } 305 #endif 306