1 /* $OpenBSD: dsa_lib.c,v 1.29 2018/04/14 07:09:21 tb 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 ENGINE_finish(dsa->engine); 112 dsa->engine = NULL; 113 #endif 114 dsa->meth = meth; 115 if (meth->init) 116 meth->init(dsa); 117 return 1; 118 } 119 120 DSA * 121 DSA_new_method(ENGINE *engine) 122 { 123 DSA *ret; 124 125 ret = malloc(sizeof(DSA)); 126 if (ret == NULL) { 127 DSAerror(ERR_R_MALLOC_FAILURE); 128 return NULL; 129 } 130 ret->meth = DSA_get_default_method(); 131 #ifndef OPENSSL_NO_ENGINE 132 if (engine) { 133 if (!ENGINE_init(engine)) { 134 DSAerror(ERR_R_ENGINE_LIB); 135 free(ret); 136 return NULL; 137 } 138 ret->engine = engine; 139 } else 140 ret->engine = ENGINE_get_default_DSA(); 141 if (ret->engine) { 142 ret->meth = ENGINE_get_DSA(ret->engine); 143 if (ret->meth == NULL) { 144 DSAerror(ERR_R_ENGINE_LIB); 145 ENGINE_finish(ret->engine); 146 free(ret); 147 return NULL; 148 } 149 } 150 #endif 151 152 ret->pad = 0; 153 ret->version = 0; 154 ret->write_params = 1; 155 ret->p = NULL; 156 ret->q = NULL; 157 ret->g = NULL; 158 159 ret->pub_key = NULL; 160 ret->priv_key = NULL; 161 162 ret->kinv = NULL; 163 ret->r = NULL; 164 ret->method_mont_p = NULL; 165 166 ret->references = 1; 167 ret->flags = ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW; 168 CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data); 169 if (ret->meth->init != NULL && !ret->meth->init(ret)) { 170 #ifndef OPENSSL_NO_ENGINE 171 ENGINE_finish(ret->engine); 172 #endif 173 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data); 174 free(ret); 175 ret = NULL; 176 } 177 178 return ret; 179 } 180 181 void 182 DSA_free(DSA *r) 183 { 184 int i; 185 186 if (r == NULL) 187 return; 188 189 i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DSA); 190 if (i > 0) 191 return; 192 193 if (r->meth->finish) 194 r->meth->finish(r); 195 #ifndef OPENSSL_NO_ENGINE 196 ENGINE_finish(r->engine); 197 #endif 198 199 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data); 200 201 BN_clear_free(r->p); 202 BN_clear_free(r->q); 203 BN_clear_free(r->g); 204 BN_clear_free(r->pub_key); 205 BN_clear_free(r->priv_key); 206 BN_clear_free(r->kinv); 207 BN_clear_free(r->r); 208 free(r); 209 } 210 211 int 212 DSA_up_ref(DSA *r) 213 { 214 int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DSA); 215 return i > 1 ? 1 : 0; 216 } 217 218 int 219 DSA_size(const DSA *r) 220 { 221 int ret, i; 222 ASN1_INTEGER bs; 223 unsigned char buf[4]; /* 4 bytes looks really small. 224 However, i2d_ASN1_INTEGER() will not look 225 beyond the first byte, as long as the second 226 parameter is NULL. */ 227 228 i = BN_num_bits(r->q); 229 bs.length = (i + 7) / 8; 230 bs.data = buf; 231 bs.type = V_ASN1_INTEGER; 232 /* If the top bit is set the asn1 encoding is 1 larger. */ 233 buf[0] = 0xff; 234 235 i = i2d_ASN1_INTEGER(&bs, NULL); 236 i += i; /* r and s */ 237 ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE); 238 return ret; 239 } 240 241 int 242 DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func, 243 CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func) 244 { 245 return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DSA, argl, argp, 246 new_func, dup_func, free_func); 247 } 248 249 int 250 DSA_set_ex_data(DSA *d, int idx, void *arg) 251 { 252 return CRYPTO_set_ex_data(&d->ex_data, idx, arg); 253 } 254 255 void * 256 DSA_get_ex_data(DSA *d, int idx) 257 { 258 return CRYPTO_get_ex_data(&d->ex_data, idx); 259 } 260 261 #ifndef OPENSSL_NO_DH 262 DH * 263 DSA_dup_DH(const DSA *r) 264 { 265 /* 266 * DSA has p, q, g, optional pub_key, optional priv_key. 267 * DH has p, optional length, g, optional pub_key, optional priv_key, 268 * optional q. 269 */ 270 DH *ret = NULL; 271 272 if (r == NULL) 273 goto err; 274 ret = DH_new(); 275 if (ret == NULL) 276 goto err; 277 if (r->p != NULL) 278 if ((ret->p = BN_dup(r->p)) == NULL) 279 goto err; 280 if (r->q != NULL) { 281 ret->length = BN_num_bits(r->q); 282 if ((ret->q = BN_dup(r->q)) == NULL) 283 goto err; 284 } 285 if (r->g != NULL) 286 if ((ret->g = BN_dup(r->g)) == NULL) 287 goto err; 288 if (r->pub_key != NULL) 289 if ((ret->pub_key = BN_dup(r->pub_key)) == NULL) 290 goto err; 291 if (r->priv_key != NULL) 292 if ((ret->priv_key = BN_dup(r->priv_key)) == NULL) 293 goto err; 294 295 return ret; 296 297 err: 298 DH_free(ret); 299 return NULL; 300 } 301 #endif 302 303 void 304 DSA_get0_pqg(const DSA *d, const BIGNUM **p, const BIGNUM **q, const BIGNUM **g) 305 { 306 if (p != NULL) 307 *p = d->p; 308 if (q != NULL) 309 *q = d->q; 310 if (g != NULL) 311 *g = d->g; 312 } 313 314 int 315 DSA_set0_pqg(DSA *d, BIGNUM *p, BIGNUM *q, BIGNUM *g) 316 { 317 if ((d->p == NULL && p == NULL) || (d->q == NULL && q == NULL) || 318 (d->g == NULL && g == NULL)) 319 return 0; 320 321 if (p != NULL) { 322 BN_free(d->p); 323 d->p = p; 324 } 325 if (q != NULL) { 326 BN_free(d->q); 327 d->q = q; 328 } 329 if (g != NULL) { 330 BN_free(d->g); 331 d->g = g; 332 } 333 334 return 1; 335 } 336 337 void 338 DSA_get0_key(const DSA *d, const BIGNUM **pub_key, const BIGNUM **priv_key) 339 { 340 if (pub_key != NULL) 341 *pub_key = d->pub_key; 342 if (priv_key != NULL) 343 *priv_key = d->priv_key; 344 } 345 346 int 347 DSA_set0_key(DSA *d, BIGNUM *pub_key, BIGNUM *priv_key) 348 { 349 if (d->pub_key == NULL && pub_key == NULL) 350 return 0; 351 352 if (pub_key != NULL) { 353 BN_free(d->pub_key); 354 d->pub_key = pub_key; 355 } 356 if (priv_key != NULL) { 357 BN_free(d->priv_key); 358 d->priv_key = priv_key; 359 } 360 361 return 1; 362 } 363 364 void 365 DSA_clear_flags(DSA *d, int flags) 366 { 367 d->flags &= ~flags; 368 } 369 370 int 371 DSA_test_flags(const DSA *d, int flags) 372 { 373 return d->flags & flags; 374 } 375 376 void 377 DSA_set_flags(DSA *d, int flags) 378 { 379 d->flags |= flags; 380 } 381 382 ENGINE * 383 DSA_get0_engine(DSA *d) 384 { 385 return d->engine; 386 } 387