1 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com) 2 * All rights reserved. 3 * 4 * This package is an SSL implementation written 5 * by Eric Young (eay (at) cryptsoft.com). 6 * The implementation was written so as to conform with Netscapes SSL. 7 * 8 * This library is free for commercial and non-commercial use as long as 9 * the following conditions are aheared to. The following conditions 10 * apply to all code found in this distribution, be it the RC4, RSA, 11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 12 * included with this distribution is covered by the same copyright terms 13 * except that the holder is Tim Hudson (tjh (at) cryptsoft.com). 14 * 15 * Copyright remains Eric Young's, and as such any Copyright notices in 16 * the code are not to be removed. 17 * If this package is used in a product, Eric Young should be given attribution 18 * as the author of the parts of the library used. 19 * This can be in the form of a textual message at program startup or 20 * in documentation (online or textual) provided with the package. 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 3. All advertising materials mentioning features or use of this software 31 * must display the following acknowledgement: 32 * "This product includes cryptographic software written by 33 * Eric Young (eay (at) cryptsoft.com)" 34 * The word 'cryptographic' can be left out if the rouines from the library 35 * being used are not cryptographic related :-). 36 * 4. If you include any Windows specific code (or a derivative thereof) from 37 * the apps directory (application code) you must include an acknowledgement: 38 * "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 50 * SUCH DAMAGE. 51 * 52 * The licence and distribution terms for any publically available version or 53 * derivative of this code cannot be changed. i.e. this code cannot simply be 54 * copied and put under another distribution licence 55 * [including the GNU Public Licence.] 56 * 57 * The DSS routines are based on patches supplied by 58 * Steven Schoch <schoch (at) sheba.arc.nasa.gov>. */ 59 60 #include <openssl/dsa.h> 61 62 #include <string.h> 63 64 #include <openssl/asn1.h> 65 #include <openssl/dh.h> 66 #include <openssl/engine.h> 67 #include <openssl/err.h> 68 #include <openssl/ex_data.h> 69 #include <openssl/mem.h> 70 #include <openssl/thread.h> 71 72 #include "internal.h" 73 #include "../internal.h" 74 75 76 extern const DSA_METHOD DSA_default_method; 77 78 static CRYPTO_EX_DATA_CLASS g_ex_data_class = CRYPTO_EX_DATA_CLASS_INIT; 79 80 DSA *DSA_new(void) { return DSA_new_method(NULL); } 81 82 DSA *DSA_new_method(const ENGINE *engine) { 83 DSA *dsa = (DSA *)OPENSSL_malloc(sizeof(DSA)); 84 if (dsa == NULL) { 85 OPENSSL_PUT_ERROR(DSA, DSA_new_method, ERR_R_MALLOC_FAILURE); 86 return NULL; 87 } 88 89 memset(dsa, 0, sizeof(DSA)); 90 91 if (engine) { 92 dsa->meth = ENGINE_get_DSA_method(engine); 93 } 94 95 if (dsa->meth == NULL) { 96 dsa->meth = (DSA_METHOD*) &DSA_default_method; 97 } 98 METHOD_ref(dsa->meth); 99 100 dsa->write_params = 1; 101 dsa->references = 1; 102 103 CRYPTO_MUTEX_init(&dsa->method_mont_p_lock); 104 105 if (!CRYPTO_new_ex_data(&g_ex_data_class, dsa, &dsa->ex_data)) { 106 METHOD_unref(dsa->meth); 107 OPENSSL_free(dsa); 108 return NULL; 109 } 110 111 if (dsa->meth->init && !dsa->meth->init(dsa)) { 112 CRYPTO_free_ex_data(&g_ex_data_class, dsa, &dsa->ex_data); 113 METHOD_unref(dsa->meth); 114 OPENSSL_free(dsa); 115 return NULL; 116 } 117 118 return dsa; 119 } 120 121 void DSA_free(DSA *dsa) { 122 if (dsa == NULL) { 123 return; 124 } 125 126 if (!CRYPTO_refcount_dec_and_test_zero(&dsa->references)) { 127 return; 128 } 129 130 if (dsa->meth->finish) { 131 dsa->meth->finish(dsa); 132 } 133 METHOD_unref(dsa->meth); 134 135 CRYPTO_free_ex_data(&g_ex_data_class, dsa, &dsa->ex_data); 136 137 BN_clear_free(dsa->p); 138 BN_clear_free(dsa->q); 139 BN_clear_free(dsa->g); 140 BN_clear_free(dsa->pub_key); 141 BN_clear_free(dsa->priv_key); 142 BN_clear_free(dsa->kinv); 143 BN_clear_free(dsa->r); 144 CRYPTO_MUTEX_cleanup(&dsa->method_mont_p_lock); 145 OPENSSL_free(dsa); 146 } 147 148 int DSA_up_ref(DSA *dsa) { 149 CRYPTO_refcount_inc(&dsa->references); 150 return 1; 151 } 152 153 int DSA_generate_parameters_ex(DSA *dsa, unsigned bits, const uint8_t *seed_in, 154 size_t seed_len, int *out_counter, 155 unsigned long *out_h, BN_GENCB *cb) { 156 if (dsa->meth->generate_parameters) { 157 return dsa->meth->generate_parameters(dsa, bits, seed_in, seed_len, 158 out_counter, out_h, cb); 159 } 160 return DSA_default_method.generate_parameters(dsa, bits, seed_in, seed_len, 161 out_counter, out_h, cb); 162 } 163 164 int DSA_generate_key(DSA *dsa) { 165 if (dsa->meth->keygen) { 166 return dsa->meth->keygen(dsa); 167 } 168 return DSA_default_method.keygen(dsa); 169 } 170 171 DSA_SIG *DSA_SIG_new(void) { 172 DSA_SIG *sig; 173 sig = OPENSSL_malloc(sizeof(DSA_SIG)); 174 if (!sig) { 175 return NULL; 176 } 177 sig->r = NULL; 178 sig->s = NULL; 179 return sig; 180 } 181 182 void DSA_SIG_free(DSA_SIG *sig) { 183 if (!sig) { 184 return; 185 } 186 187 BN_free(sig->r); 188 BN_free(sig->s); 189 OPENSSL_free(sig); 190 } 191 192 DSA_SIG *DSA_do_sign(const uint8_t *digest, size_t digest_len, DSA *dsa) { 193 if (dsa->meth->sign) { 194 return dsa->meth->sign(digest, digest_len, dsa); 195 } 196 return DSA_default_method.sign(digest, digest_len, dsa); 197 } 198 199 int DSA_do_verify(const uint8_t *digest, size_t digest_len, DSA_SIG *sig, 200 const DSA *dsa) { 201 int valid; 202 if (!DSA_do_check_signature(&valid, digest, digest_len, sig, dsa)) { 203 return -1; 204 } 205 return valid; 206 } 207 208 int DSA_do_check_signature(int *out_valid, const uint8_t *digest, 209 size_t digest_len, DSA_SIG *sig, const DSA *dsa) { 210 if (dsa->meth->verify) { 211 return dsa->meth->verify(out_valid, digest, digest_len, sig, dsa); 212 } 213 214 return DSA_default_method.verify(out_valid, digest, digest_len, sig, dsa); 215 } 216 217 int DSA_sign(int type, const uint8_t *digest, size_t digest_len, 218 uint8_t *out_sig, unsigned int *out_siglen, DSA *dsa) { 219 DSA_SIG *s; 220 221 s = DSA_do_sign(digest, digest_len, dsa); 222 if (s == NULL) { 223 *out_siglen = 0; 224 return 0; 225 } 226 227 *out_siglen = i2d_DSA_SIG(s, &out_sig); 228 DSA_SIG_free(s); 229 return 1; 230 } 231 232 int DSA_verify(int type, const uint8_t *digest, size_t digest_len, 233 const uint8_t *sig, size_t sig_len, const DSA *dsa) { 234 int valid; 235 if (!DSA_check_signature(&valid, digest, digest_len, sig, sig_len, dsa)) { 236 return -1; 237 } 238 return valid; 239 } 240 241 int DSA_check_signature(int *out_valid, const uint8_t *digest, 242 size_t digest_len, const uint8_t *sig, size_t sig_len, 243 const DSA *dsa) { 244 DSA_SIG *s = NULL; 245 int ret = 0; 246 uint8_t *der = NULL; 247 248 s = DSA_SIG_new(); 249 if (s == NULL) { 250 goto err; 251 } 252 253 const uint8_t *sigp = sig; 254 if (d2i_DSA_SIG(&s, &sigp, sig_len) == NULL || sigp != sig + sig_len) { 255 goto err; 256 } 257 258 /* Ensure that the signature uses DER and doesn't have trailing garbage. */ 259 int der_len = i2d_DSA_SIG(s, &der); 260 if (der_len < 0 || (size_t)der_len != sig_len || memcmp(sig, der, sig_len)) { 261 goto err; 262 } 263 264 ret = DSA_do_check_signature(out_valid, digest, digest_len, s, dsa); 265 266 err: 267 OPENSSL_free(der); 268 DSA_SIG_free(s); 269 return ret; 270 } 271 272 int DSA_size(const DSA *dsa) { 273 int ret, i; 274 ASN1_INTEGER bs; 275 unsigned char buf[4]; /* 4 bytes looks really small. 276 However, i2d_ASN1_INTEGER() will not look 277 beyond the first byte, as long as the second 278 parameter is NULL. */ 279 280 i = BN_num_bits(dsa->q); 281 bs.length = (i + 7) / 8; 282 bs.data = buf; 283 bs.type = V_ASN1_INTEGER; 284 /* If the top bit is set the asn1 encoding is 1 larger. */ 285 buf[0] = 0xff; 286 287 i = i2d_ASN1_INTEGER(&bs, NULL); 288 i += i; /* r and s */ 289 ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE); 290 return ret; 291 } 292 293 int DSA_sign_setup(const DSA *dsa, BN_CTX *ctx, BIGNUM **out_kinv, 294 BIGNUM **out_r) { 295 if (dsa->meth->sign_setup) { 296 return dsa->meth->sign_setup(dsa, ctx, out_kinv, out_r, NULL, 0); 297 } 298 299 return DSA_default_method.sign_setup(dsa, ctx, out_kinv, out_r, NULL, 0); 300 } 301 302 int DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func, 303 CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func) { 304 int index; 305 if (!CRYPTO_get_ex_new_index(&g_ex_data_class, &index, argl, argp, new_func, 306 dup_func, free_func)) { 307 return -1; 308 } 309 return index; 310 } 311 312 int DSA_set_ex_data(DSA *d, int idx, void *arg) { 313 return CRYPTO_set_ex_data(&d->ex_data, idx, arg); 314 } 315 316 void *DSA_get_ex_data(const DSA *d, int idx) { 317 return CRYPTO_get_ex_data(&d->ex_data, idx); 318 } 319 320 DH *DSA_dup_DH(const DSA *r) { 321 DH *ret = NULL; 322 323 if (r == NULL) { 324 goto err; 325 } 326 ret = DH_new(); 327 if (ret == NULL) { 328 goto err; 329 } 330 if (r->q != NULL) { 331 ret->priv_length = BN_num_bits(r->q); 332 if ((ret->q = BN_dup(r->q)) == NULL) { 333 goto err; 334 } 335 } 336 if ((r->p != NULL && (ret->p = BN_dup(r->p)) == NULL) || 337 (r->g != NULL && (ret->g = BN_dup(r->g)) == NULL) || 338 (r->pub_key != NULL && (ret->pub_key = BN_dup(r->pub_key)) == NULL) || 339 (r->priv_key != NULL && (ret->priv_key = BN_dup(r->priv_key)) == NULL)) { 340 goto err; 341 } 342 343 return ret; 344 345 err: 346 DH_free(ret); 347 return NULL; 348 } 349
