1 /* $OpenBSD: ecdsatest.c,v 1.16 2023/05/04 13:49:29 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 int test_builtin(void); 87 88 int 89 test_builtin(void) 90 { 91 unsigned char digest[20], wrong_digest[20]; 92 EC_builtin_curve *curves = NULL; 93 size_t num_curves = 0, n = 0; 94 EC_KEY *eckey = NULL, *wrong_eckey = NULL; 95 EC_GROUP *group; 96 ECDSA_SIG *ecdsa_sig = NULL; 97 BIGNUM *r = NULL, *s = NULL; 98 unsigned char *signature = NULL; 99 const unsigned char *sig_ptr; 100 unsigned char *sig_ptr2; 101 unsigned char *raw_buf = NULL; 102 unsigned int sig_len, degree, r_len, s_len, bn_len, buf_len; 103 int nid; 104 int failed = 1; 105 106 /* fill digest values with some random data */ 107 arc4random_buf(digest, 20); 108 arc4random_buf(wrong_digest, 20); 109 110 /* create and verify a ecdsa signature with every available curve */ 111 printf("\ntesting ECDSA_sign() and ECDSA_verify() " 112 "with some internal curves:\n"); 113 114 /* get a list of all internal curves */ 115 num_curves = EC_get_builtin_curves(NULL, 0); 116 117 curves = reallocarray(NULL, sizeof(EC_builtin_curve), num_curves); 118 if (curves == NULL) { 119 printf("reallocarray error\n"); 120 goto err; 121 } 122 123 if (!EC_get_builtin_curves(curves, num_curves)) { 124 printf("unable to get internal curves\n"); 125 goto err; 126 } 127 128 /* now create and verify a signature for every curve */ 129 for (n = 0; n < num_curves; n++) { 130 unsigned char dirt, offset; 131 132 nid = curves[n].nid; 133 if (nid == NID_ipsec4) 134 continue; 135 136 if ((eckey = EC_KEY_new()) == NULL) 137 goto err; 138 group = EC_GROUP_new_by_curve_name(nid); 139 if (group == NULL) 140 goto err; 141 if (EC_KEY_set_group(eckey, group) == 0) 142 goto err; 143 degree = EC_GROUP_get_degree(group); 144 EC_GROUP_free(group); 145 if (degree < 160) { 146 /* drop the curve */ 147 EC_KEY_free(eckey); 148 eckey = NULL; 149 continue; 150 } 151 printf("%s: ", OBJ_nid2sn(nid)); 152 153 if (!EC_KEY_generate_key(eckey)) { 154 goto err; 155 } 156 157 /* Exercise ECParameters_dup() and let ASAN test for leaks. */ 158 if ((wrong_eckey = ECParameters_dup(key)) == NULL) 159 goto err; 160 group = EC_GROUP_new_by_curve_name(nid); 161 if (group == NULL) 162 goto err; 163 if (EC_KEY_set_group(wrong_eckey, group) == 0) 164 goto err; 165 EC_GROUP_free(group); 166 if (!EC_KEY_generate_key(wrong_eckey)) 167 goto err; 168 169 printf("."); 170 fflush(stdout); 171 172 if (!EC_KEY_check_key(eckey)) 173 goto err; 174 175 printf("."); 176 fflush(stdout); 177 178 if ((sig_len = ECDSA_size(eckey)) == 0) 179 goto err; 180 if ((signature = malloc(sig_len)) == NULL) 181 goto err; 182 if (!ECDSA_sign(0, digest, 20, signature, &sig_len, eckey)) 183 goto err; 184 185 printf("."); 186 fflush(stdout); 187 188 if (ECDSA_verify(0, digest, 20, signature, sig_len, eckey) != 1) 189 goto err; 190 191 printf("."); 192 fflush(stdout); 193 194 /* verify signature with the wrong key */ 195 if (ECDSA_verify(0, digest, 20, signature, sig_len, 196 wrong_eckey) == 1) 197 goto err; 198 199 printf("."); 200 fflush(stdout); 201 202 if (ECDSA_verify(0, wrong_digest, 20, signature, sig_len, 203 eckey) == 1) 204 goto err; 205 206 printf("."); 207 fflush(stdout); 208 209 if (ECDSA_verify(0, digest, 20, signature, sig_len - 1, 210 eckey) == 1) 211 goto err; 212 213 printf("."); 214 fflush(stdout); 215 216 /* 217 * Modify a single byte of the signature: to ensure we don't 218 * garble the ASN1 structure, we read the raw signature and 219 * modify a byte in one of the bignums directly. 220 */ 221 sig_ptr = signature; 222 if ((ecdsa_sig = d2i_ECDSA_SIG(NULL, &sig_ptr, 223 sig_len)) == NULL) 224 goto err; 225 226 /* Store the two BIGNUMs in raw_buf. */ 227 r_len = BN_num_bytes(ECDSA_SIG_get0_r(ecdsa_sig)); 228 s_len = BN_num_bytes(ECDSA_SIG_get0_s(ecdsa_sig)); 229 bn_len = (degree + 7) / 8; 230 if ((r_len > bn_len) || (s_len > bn_len)) 231 goto err; 232 233 buf_len = 2 * bn_len; 234 if ((raw_buf = calloc(1, buf_len)) == NULL) 235 goto err; 236 BN_bn2bin(ECDSA_SIG_get0_r(ecdsa_sig), 237 raw_buf + bn_len - r_len); 238 BN_bn2bin(ECDSA_SIG_get0_s(ecdsa_sig), 239 raw_buf + buf_len - s_len); 240 241 /* Modify a single byte in the buffer. */ 242 offset = raw_buf[10] % buf_len; 243 dirt = raw_buf[11] ? raw_buf[11] : 1; 244 raw_buf[offset] ^= dirt; 245 /* Now read the BIGNUMs back in from raw_buf. */ 246 if ((r = BN_bin2bn(raw_buf, bn_len, NULL)) == NULL || 247 (s = BN_bin2bn(raw_buf + bn_len, bn_len, NULL)) == NULL) 248 goto err; 249 if (!ECDSA_SIG_set0(ecdsa_sig, r, s)) 250 goto err; 251 r = NULL; 252 s = NULL; 253 254 if ((sig_len = i2d_ECDSA_SIG(ecdsa_sig, NULL)) <= 0) 255 goto err; 256 free(signature); 257 if ((signature = calloc(1, sig_len)) == NULL) 258 goto err; 259 260 sig_ptr2 = signature; 261 if ((sig_len = i2d_ECDSA_SIG(ecdsa_sig, &sig_ptr2)) <= 0) 262 goto err; 263 if (ECDSA_verify(0, digest, 20, signature, sig_len, eckey) == 1) 264 goto err; 265 266 /* Sanity check: undo the modification and verify signature. */ 267 raw_buf[offset] ^= dirt; 268 if ((r = BN_bin2bn(raw_buf, bn_len, NULL)) == NULL || 269 (s = BN_bin2bn(raw_buf + bn_len, bn_len, NULL)) == NULL) 270 goto err; 271 if (!ECDSA_SIG_set0(ecdsa_sig, r, s)) 272 goto err; 273 r = NULL; 274 s = NULL; 275 276 if ((sig_len = i2d_ECDSA_SIG(ecdsa_sig, NULL)) <= 0) 277 goto err; 278 free(signature); 279 if ((signature = calloc(1, sig_len)) == NULL) 280 goto err; 281 282 sig_ptr2 = signature; 283 if ((sig_len = i2d_ECDSA_SIG(ecdsa_sig, &sig_ptr2)) <= 0) 284 goto err; 285 if (ECDSA_verify(0, digest, 20, signature, sig_len, 286 eckey) != 1) 287 goto err; 288 289 printf("."); 290 fflush(stdout); 291 292 printf(" ok\n"); 293 294 ERR_clear_error(); 295 free(signature); 296 signature = NULL; 297 EC_KEY_free(eckey); 298 eckey = NULL; 299 EC_KEY_free(wrong_eckey); 300 wrong_eckey = NULL; 301 ECDSA_SIG_free(ecdsa_sig); 302 ecdsa_sig = NULL; 303 free(raw_buf); 304 raw_buf = NULL; 305 } 306 307 failed = 0; 308 309 err: 310 if (failed) 311 printf(" failed\n"); 312 313 BN_free(r); 314 BN_free(s); 315 EC_KEY_free(eckey); 316 EC_KEY_free(wrong_eckey); 317 ECDSA_SIG_free(ecdsa_sig); 318 free(signature); 319 free(raw_buf); 320 free(curves); 321 322 return failed; 323 } 324 325 int 326 main(void) 327 { 328 int failed = 1; 329 330 /* the tests */ 331 if (test_builtin()) 332 goto err; 333 334 printf("\nECDSA test passed\n"); 335 failed = 0; 336 337 err: 338 if (failed) { 339 printf("\nECDSA test failed\n"); 340 ERR_print_errors_fp(stdout); 341 } 342 343 CRYPTO_cleanup_all_ex_data(); 344 ERR_remove_thread_state(NULL); 345 ERR_free_strings(); 346 347 return failed; 348 } 349