1 /* $OpenBSD: ecdsatest.c,v 1.6 2018/07/17 17:10:04 tb Exp $ */ 2 /* 3 * Written by Nils Larsch for the OpenSSL project. 4 */ 5 /* ==================================================================== 6 * Copyright (c) 2000-2005 The OpenSSL Project. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in 17 * the documentation and/or other materials provided with the 18 * distribution. 19 * 20 * 3. All advertising materials mentioning features or use of this 21 * software must display the following acknowledgment: 22 * "This product includes software developed by the OpenSSL Project 23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 24 * 25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26 * endorse or promote products derived from this software without 27 * prior written permission. For written permission, please contact 28 * licensing@OpenSSL.org. 29 * 30 * 5. Products derived from this software may not be called "OpenSSL" 31 * nor may "OpenSSL" appear in their names without prior written 32 * permission of the OpenSSL Project. 33 * 34 * 6. Redistributions of any form whatsoever must retain the following 35 * acknowledgment: 36 * "This product includes software developed by the OpenSSL Project 37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 38 * 39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50 * OF THE POSSIBILITY OF SUCH DAMAGE. 51 * ==================================================================== 52 * 53 * This product includes cryptographic software written by Eric Young 54 * (eay@cryptsoft.com). This product includes software written by Tim 55 * Hudson (tjh@cryptsoft.com). 56 * 57 */ 58 /* ==================================================================== 59 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. 60 * 61 * Portions of the attached software ("Contribution") are developed by 62 * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project. 63 * 64 * The Contribution is licensed pursuant to the OpenSSL open source 65 * license provided above. 66 * 67 * The elliptic curve binary polynomial software is originally written by 68 * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems Laboratories. 69 * 70 */ 71 72 #include <stdio.h> 73 #include <stdlib.h> 74 #include <string.h> 75 76 #include <openssl/crypto.h> 77 #include <openssl/bio.h> 78 #include <openssl/evp.h> 79 #include <openssl/bn.h> 80 #include <openssl/ecdsa.h> 81 #ifndef OPENSSL_NO_ENGINE 82 #include <openssl/engine.h> 83 #endif 84 #include <openssl/err.h> 85 86 /* declaration of the test functions */ 87 int x9_62_test_internal(BIO *out, int nid, const char *r, const char *s); 88 int test_builtin(BIO *); 89 90 /* some tests from the X9.62 draft */ 91 int 92 x9_62_test_internal(BIO *out, int nid, const char *r_in, const char *s_in) 93 { 94 int ret = 0; 95 const char message[] = "abc"; 96 unsigned char digest[20]; 97 unsigned int dgst_len = 0; 98 EVP_MD_CTX md_ctx; 99 EC_KEY *key = NULL; 100 ECDSA_SIG *signature = NULL; 101 BIGNUM *r = NULL, *s = NULL; 102 103 EVP_MD_CTX_init(&md_ctx); 104 /* get the message digest */ 105 EVP_DigestInit(&md_ctx, EVP_ecdsa()); 106 EVP_DigestUpdate(&md_ctx, (const void*)message, 3); 107 EVP_DigestFinal(&md_ctx, digest, &dgst_len); 108 109 BIO_printf(out, "testing %s: ", OBJ_nid2sn(nid)); 110 /* create the key */ 111 if ((key = EC_KEY_new_by_curve_name(nid)) == NULL) 112 goto x962_int_err; 113 if (!EC_KEY_generate_key(key)) 114 goto x962_int_err; 115 BIO_printf(out, "."); 116 (void)BIO_flush(out); 117 /* create the signature */ 118 signature = ECDSA_do_sign(digest, 20, key); 119 if (signature == NULL) 120 goto x962_int_err; 121 BIO_printf(out, "."); 122 (void)BIO_flush(out); 123 /* compare the created signature with the expected signature */ 124 if ((r = BN_new()) == NULL || (s = BN_new()) == NULL) 125 goto x962_int_err; 126 if (!BN_dec2bn(&r, r_in) || 127 !BN_dec2bn(&s, s_in)) 128 goto x962_int_err; 129 if (BN_cmp(signature->r ,r) || BN_cmp(signature->s, s)) 130 goto x962_int_err; 131 BIO_printf(out, "."); 132 (void)BIO_flush(out); 133 /* verify the signature */ 134 if (ECDSA_do_verify(digest, 20, signature, key) != 1) 135 goto x962_int_err; 136 BIO_printf(out, "."); 137 (void)BIO_flush(out); 138 139 BIO_printf(out, " ok\n"); 140 ret = 1; 141 x962_int_err: 142 if (!ret) 143 BIO_printf(out, " failed\n"); 144 if (key) 145 EC_KEY_free(key); 146 if (signature) 147 ECDSA_SIG_free(signature); 148 if (r) 149 BN_free(r); 150 if (s) 151 BN_free(s); 152 EVP_MD_CTX_cleanup(&md_ctx); 153 return ret; 154 } 155 156 int 157 test_builtin(BIO *out) 158 { 159 EC_builtin_curve *curves = NULL; 160 size_t num_curves = 0, n = 0; 161 EC_KEY *eckey = NULL, *wrong_eckey = NULL; 162 EC_GROUP *group; 163 ECDSA_SIG *ecdsa_sig = NULL; 164 unsigned char digest[20], wrong_digest[20]; 165 unsigned char *signature = NULL; 166 const unsigned char *sig_ptr; 167 unsigned char *sig_ptr2; 168 unsigned char *raw_buf = NULL; 169 unsigned int sig_len, degree, r_len, s_len, bn_len, buf_len; 170 int nid, ret = 0; 171 172 /* fill digest values with some random data */ 173 arc4random_buf(digest, 20); 174 arc4random_buf(wrong_digest, 20); 175 176 /* create and verify a ecdsa signature with every available curve */ 177 BIO_printf(out, "\ntesting ECDSA_sign() and ECDSA_verify() " 178 "with some internal curves:\n"); 179 180 /* get a list of all internal curves */ 181 num_curves = EC_get_builtin_curves(NULL, 0); 182 183 curves = reallocarray(NULL, sizeof(EC_builtin_curve), num_curves); 184 185 if (curves == NULL) { 186 BIO_printf(out, "reallocarray error\n"); 187 goto builtin_err; 188 } 189 190 if (!EC_get_builtin_curves(curves, num_curves)) { 191 BIO_printf(out, "unable to get internal curves\n"); 192 goto builtin_err; 193 } 194 195 /* now create and verify a signature for every curve */ 196 for (n = 0; n < num_curves; n++) { 197 unsigned char dirt, offset; 198 199 nid = curves[n].nid; 200 if (nid == NID_ipsec4) 201 continue; 202 /* create new ecdsa key (== EC_KEY) */ 203 if ((eckey = EC_KEY_new()) == NULL) 204 goto builtin_err; 205 group = EC_GROUP_new_by_curve_name(nid); 206 if (group == NULL) 207 goto builtin_err; 208 if (EC_KEY_set_group(eckey, group) == 0) 209 goto builtin_err; 210 EC_GROUP_free(group); 211 degree = EC_GROUP_get_degree(EC_KEY_get0_group(eckey)); 212 if (degree < 160) { 213 /* drop the curve */ 214 EC_KEY_free(eckey); 215 eckey = NULL; 216 continue; 217 } 218 BIO_printf(out, "%s: ", OBJ_nid2sn(nid)); 219 /* create key */ 220 if (!EC_KEY_generate_key(eckey)) { 221 BIO_printf(out, " failed\n"); 222 goto builtin_err; 223 } 224 /* create second key */ 225 if ((wrong_eckey = EC_KEY_new()) == NULL) 226 goto builtin_err; 227 group = EC_GROUP_new_by_curve_name(nid); 228 if (group == NULL) 229 goto builtin_err; 230 if (EC_KEY_set_group(wrong_eckey, group) == 0) 231 goto builtin_err; 232 EC_GROUP_free(group); 233 if (!EC_KEY_generate_key(wrong_eckey)) { 234 BIO_printf(out, " failed\n"); 235 goto builtin_err; 236 } 237 238 BIO_printf(out, "."); 239 (void)BIO_flush(out); 240 /* check key */ 241 if (!EC_KEY_check_key(eckey)) { 242 BIO_printf(out, " failed\n"); 243 goto builtin_err; 244 } 245 BIO_printf(out, "."); 246 (void)BIO_flush(out); 247 /* create signature */ 248 sig_len = ECDSA_size(eckey); 249 if ((signature = malloc(sig_len)) == NULL) 250 goto builtin_err; 251 if (!ECDSA_sign(0, digest, 20, signature, &sig_len, eckey)) { 252 BIO_printf(out, " failed\n"); 253 goto builtin_err; 254 } 255 BIO_printf(out, "."); 256 (void)BIO_flush(out); 257 /* verify signature */ 258 if (ECDSA_verify(0, digest, 20, signature, sig_len, 259 eckey) != 1) { 260 BIO_printf(out, " failed\n"); 261 goto builtin_err; 262 } 263 BIO_printf(out, "."); 264 (void)BIO_flush(out); 265 /* verify signature with the wrong key */ 266 if (ECDSA_verify(0, digest, 20, signature, sig_len, 267 wrong_eckey) == 1) { 268 BIO_printf(out, " failed\n"); 269 goto builtin_err; 270 } 271 BIO_printf(out, "."); 272 (void)BIO_flush(out); 273 /* wrong digest */ 274 if (ECDSA_verify(0, wrong_digest, 20, signature, sig_len, 275 eckey) == 1) { 276 BIO_printf(out, " failed\n"); 277 goto builtin_err; 278 } 279 BIO_printf(out, "."); 280 (void)BIO_flush(out); 281 /* wrong length */ 282 if (ECDSA_verify(0, digest, 20, signature, sig_len - 1, 283 eckey) == 1) { 284 BIO_printf(out, " failed\n"); 285 goto builtin_err; 286 } 287 BIO_printf(out, "."); 288 (void)BIO_flush(out); 289 290 /* 291 * Modify a single byte of the signature: to ensure we don't 292 * garble the ASN1 structure, we read the raw signature and 293 * modify a byte in one of the bignums directly. 294 */ 295 sig_ptr = signature; 296 if ((ecdsa_sig = d2i_ECDSA_SIG(NULL, &sig_ptr, 297 sig_len)) == NULL) { 298 BIO_printf(out, " failed\n"); 299 goto builtin_err; 300 } 301 302 /* Store the two BIGNUMs in raw_buf. */ 303 r_len = BN_num_bytes(ecdsa_sig->r); 304 s_len = BN_num_bytes(ecdsa_sig->s); 305 bn_len = (degree + 7) / 8; 306 if ((r_len > bn_len) || (s_len > bn_len)) { 307 BIO_printf(out, " failed\n"); 308 goto builtin_err; 309 } 310 buf_len = 2 * bn_len; 311 if ((raw_buf = calloc(1, buf_len)) == NULL) 312 goto builtin_err; 313 BN_bn2bin(ecdsa_sig->r, raw_buf + bn_len - r_len); 314 BN_bn2bin(ecdsa_sig->s, raw_buf + buf_len - s_len); 315 316 /* Modify a single byte in the buffer. */ 317 offset = raw_buf[10] % buf_len; 318 dirt = raw_buf[11] ? raw_buf[11] : 1; 319 raw_buf[offset] ^= dirt; 320 /* Now read the BIGNUMs back in from raw_buf. */ 321 if ((BN_bin2bn(raw_buf, bn_len, ecdsa_sig->r) == NULL) || 322 (BN_bin2bn(raw_buf + bn_len, bn_len, ecdsa_sig->s) == NULL)) 323 goto builtin_err; 324 325 sig_ptr2 = signature; 326 sig_len = i2d_ECDSA_SIG(ecdsa_sig, &sig_ptr2); 327 if (ECDSA_verify(0, digest, 20, signature, sig_len, 328 eckey) == 1) { 329 BIO_printf(out, " failed\n"); 330 goto builtin_err; 331 } 332 /* Sanity check: undo the modification and verify signature. */ 333 raw_buf[offset] ^= dirt; 334 if ((BN_bin2bn(raw_buf, bn_len, ecdsa_sig->r) == NULL) || 335 (BN_bin2bn(raw_buf + bn_len, bn_len, ecdsa_sig->s) == NULL)) 336 goto builtin_err; 337 338 sig_ptr2 = signature; 339 sig_len = i2d_ECDSA_SIG(ecdsa_sig, &sig_ptr2); 340 if (ECDSA_verify(0, digest, 20, signature, sig_len, 341 eckey) != 1) { 342 BIO_printf(out, " failed\n"); 343 goto builtin_err; 344 } 345 BIO_printf(out, "."); 346 (void)BIO_flush(out); 347 348 BIO_printf(out, " ok\n"); 349 /* cleanup */ 350 /* clean bogus errors */ 351 ERR_clear_error(); 352 free(signature); 353 signature = NULL; 354 EC_KEY_free(eckey); 355 eckey = NULL; 356 EC_KEY_free(wrong_eckey); 357 wrong_eckey = NULL; 358 ECDSA_SIG_free(ecdsa_sig); 359 ecdsa_sig = NULL; 360 free(raw_buf); 361 raw_buf = NULL; 362 } 363 364 ret = 1; 365 builtin_err: 366 EC_KEY_free(eckey); 367 EC_KEY_free(wrong_eckey); 368 ECDSA_SIG_free(ecdsa_sig); 369 free(signature); 370 free(raw_buf); 371 free(curves); 372 373 return ret; 374 } 375 376 int 377 main(void) 378 { 379 int ret = 1; 380 BIO *out; 381 382 out = BIO_new_fp(stdout, BIO_NOCLOSE); 383 384 ERR_load_crypto_strings(); 385 386 /* the tests */ 387 if (!test_builtin(out)) 388 goto err; 389 390 ret = 0; 391 err: 392 if (ret) 393 BIO_printf(out, "\nECDSA test failed\n"); 394 else 395 BIO_printf(out, "\nECDSA test passed\n"); 396 if (ret) 397 ERR_print_errors(out); 398 CRYPTO_cleanup_all_ex_data(); 399 ERR_remove_thread_state(NULL); 400 ERR_free_strings(); 401 CRYPTO_mem_leaks(out); 402 if (out != NULL) 403 BIO_free(out); 404 return ret; 405 } 406