| 1 | /* |
| 2 | * Copyright (c) 2007-2016, Cameron Rich |
| 3 | * |
| 4 | * All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions are met: |
| 8 | * |
| 9 | * * Redistributions of source code must retain the above copyright notice, |
| 10 | * this list of conditions and the following disclaimer. |
| 11 | * * Redistributions in binary form must reproduce the above copyright notice, |
| 12 | * this list of conditions and the following disclaimer in the documentation |
| 13 | * and/or other materials provided with the distribution. |
| 14 | * * Neither the name of the axTLS project nor the names of its contributors |
| 15 | * may be used to endorse or promote products derived from this software |
| 16 | * without specific prior written permission. |
| 17 | * |
| 18 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 19 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 20 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 21 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| 22 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| 23 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 24 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| 25 | * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| 26 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| 27 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| 28 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 29 | */ |
| 30 | |
| 31 | /** |
| 32 | * @file x509.c |
| 33 | * |
| 34 | * Certificate processing. |
| 35 | */ |
| 36 | |
| 37 | #include <stdio.h> |
| 38 | #include <stdlib.h> |
| 39 | #include <string.h> |
| 40 | #include <time.h> |
| 41 | #include "os_port.h" |
| 42 | #include "crypto_misc.h" |
| 43 | |
| 44 | #ifdef CONFIG_SSL_CERT_VERIFICATION |
| 45 | static int x509_v3_subject_alt_name(const uint8_t *cert, int offset, |
| 46 | X509_CTX *x509_ctx); |
| 47 | static int x509_v3_basic_constraints(const uint8_t *cert, int offset, |
| 48 | X509_CTX *x509_ctx); |
| 49 | static int x509_v3_key_usage(const uint8_t *cert, int offset, |
| 50 | X509_CTX *x509_ctx); |
| 51 | |
| 52 | /** |
| 53 | * Retrieve the signature from a certificate. |
| 54 | */ |
| 55 | static const uint8_t *get_signature(const uint8_t *asn1_sig, int *len) |
| 56 | { |
| 57 | int offset = 0; |
| 58 | const uint8_t *ptr = NULL; |
| 59 | |
| 60 | if (asn1_next_obj(asn1_sig, &offset, ASN1_SEQUENCE) < 0 || |
| 61 | asn1_skip_obj(asn1_sig, &offset, ASN1_SEQUENCE)) |
| 62 | goto end_get_sig; |
| 63 | |
| 64 | if (asn1_sig[offset++] != ASN1_OCTET_STRING) |
| 65 | goto end_get_sig; |
| 66 | *len = get_asn1_length(asn1_sig, &offset); |
| 67 | ptr = &asn1_sig[offset]; /* all ok */ |
| 68 | |
| 69 | end_get_sig: |
| 70 | return ptr; |
| 71 | } |
| 72 | |
| 73 | #endif |
| 74 | |
| 75 | /** |
| 76 | * Construct a new x509 object. |
| 77 | * @return 0 if ok. < 0 if there was a problem. |
| 78 | */ |
| 79 | int x509_new(const uint8_t *cert, int *len, X509_CTX **ctx) |
| 80 | { |
| 81 | int begin_tbs, end_tbs; |
| 82 | int ret = X509_NOT_OK, offset = 0, cert_size = 0; |
| 83 | int version = 0; |
| 84 | X509_CTX *x509_ctx; |
| 85 | #ifdef CONFIG_SSL_CERT_VERIFICATION /* only care if doing verification */ |
| 86 | BI_CTX *bi_ctx; |
| 87 | #endif |
| 88 | |
| 89 | *ctx = (X509_CTX *)calloc(1, sizeof(X509_CTX)); |
| 90 | x509_ctx = *ctx; |
| 91 | |
| 92 | /* get the certificate size */ |
| 93 | asn1_skip_obj(cert, &cert_size, ASN1_SEQUENCE); |
| 94 | |
| 95 | if (asn1_next_obj(cert, &offset, ASN1_SEQUENCE) < 0) |
| 96 | goto end_cert; |
| 97 | |
| 98 | begin_tbs = offset; /* start of the tbs */ |
| 99 | end_tbs = begin_tbs; /* work out the end of the tbs */ |
| 100 | asn1_skip_obj(cert, &end_tbs, ASN1_SEQUENCE); |
| 101 | |
| 102 | if (asn1_next_obj(cert, &offset, ASN1_SEQUENCE) < 0) |
| 103 | goto end_cert; |
| 104 | |
| 105 | /* optional version */ |
| 106 | if (cert[offset] == ASN1_EXPLICIT_TAG && |
| 107 | asn1_version(cert, &offset, &version) == X509_NOT_OK) |
| 108 | goto end_cert; |
| 109 | |
| 110 | if (asn1_skip_obj(cert, &offset, ASN1_INTEGER) || /* serial number */ |
| 111 | asn1_next_obj(cert, &offset, ASN1_SEQUENCE) < 0) |
| 112 | goto end_cert; |
| 113 | |
| 114 | /* make sure the signature is ok */ |
| 115 | if (asn1_signature_type(cert, &offset, x509_ctx)) |
| 116 | { |
| 117 | ret = X509_VFY_ERROR_UNSUPPORTED_DIGEST; |
| 118 | goto end_cert; |
| 119 | } |
| 120 | |
| 121 | if (asn1_name(cert, &offset, x509_ctx->ca_cert_dn) || |
| 122 | asn1_validity(cert, &offset, x509_ctx) || |
| 123 | asn1_name(cert, &offset, x509_ctx->cert_dn) || |
| 124 | asn1_public_key(cert, &offset, x509_ctx)) |
| 125 | { |
| 126 | goto end_cert; |
| 127 | } |
| 128 | |
| 129 | #ifdef CONFIG_SSL_CERT_VERIFICATION /* only care if doing verification */ |
| 130 | bi_ctx = x509_ctx->rsa_ctx->bi_ctx; |
| 131 | |
| 132 | /* use the appropriate signature algorithm */ |
| 133 | switch (x509_ctx->sig_type) |
| 134 | { |
| 135 | case SIG_TYPE_MD5: |
| 136 | { |
| 137 | MD5_CTX md5_ctx; |
| 138 | uint8_t md5_dgst[MD5_SIZE]; |
| 139 | MD5_Init(&md5_ctx); |
| 140 | MD5_Update(&md5_ctx, &cert[begin_tbs], end_tbs-begin_tbs); |
| 141 | MD5_Final(md5_dgst, &md5_ctx); |
| 142 | x509_ctx->digest = bi_import(bi_ctx, md5_dgst, MD5_SIZE); |
| 143 | } |
| 144 | break; |
| 145 | |
| 146 | case SIG_TYPE_SHA1: |
| 147 | { |
| 148 | SHA1_CTX sha_ctx; |
| 149 | uint8_t sha_dgst[SHA1_SIZE]; |
| 150 | SHA1_Init(&sha_ctx); |
| 151 | SHA1_Update(&sha_ctx, &cert[begin_tbs], end_tbs-begin_tbs); |
| 152 | SHA1_Final(sha_dgst, &sha_ctx); |
| 153 | x509_ctx->digest = bi_import(bi_ctx, sha_dgst, SHA1_SIZE); |
| 154 | } |
| 155 | break; |
| 156 | |
| 157 | case SIG_TYPE_SHA256: |
| 158 | { |
| 159 | SHA256_CTX sha256_ctx; |
| 160 | uint8_t sha256_dgst[SHA256_SIZE]; |
| 161 | SHA256_Init(&sha256_ctx); |
| 162 | SHA256_Update(&sha256_ctx, &cert[begin_tbs], end_tbs-begin_tbs); |
| 163 | SHA256_Final(sha256_dgst, &sha256_ctx); |
| 164 | x509_ctx->digest = bi_import(bi_ctx, sha256_dgst, SHA256_SIZE); |
| 165 | } |
| 166 | break; |
| 167 | |
| 168 | case SIG_TYPE_SHA384: |
| 169 | { |
| 170 | SHA384_CTX sha384_ctx; |
| 171 | uint8_t sha384_dgst[SHA384_SIZE]; |
| 172 | SHA384_Init(&sha384_ctx); |
| 173 | SHA384_Update(&sha384_ctx, &cert[begin_tbs], end_tbs-begin_tbs); |
| 174 | SHA384_Final(sha384_dgst, &sha384_ctx); |
| 175 | x509_ctx->digest = bi_import(bi_ctx, sha384_dgst, SHA384_SIZE); |
| 176 | } |
| 177 | break; |
| 178 | |
| 179 | case SIG_TYPE_SHA512: |
| 180 | { |
| 181 | SHA512_CTX sha512_ctx; |
| 182 | uint8_t sha512_dgst[SHA512_SIZE]; |
| 183 | SHA512_Init(&sha512_ctx); |
| 184 | SHA512_Update(&sha512_ctx, &cert[begin_tbs], end_tbs-begin_tbs); |
| 185 | SHA512_Final(sha512_dgst, &sha512_ctx); |
| 186 | x509_ctx->digest = bi_import(bi_ctx, sha512_dgst, SHA512_SIZE); |
| 187 | } |
| 188 | break; |
| 189 | } |
| 190 | |
| 191 | if (version == 2 && asn1_next_obj(cert, &offset, ASN1_V3_DATA) > 0) |
| 192 | { |
| 193 | x509_v3_subject_alt_name(cert, offset, x509_ctx); |
| 194 | x509_v3_basic_constraints(cert, offset, x509_ctx); |
| 195 | x509_v3_key_usage(cert, offset, x509_ctx); |
| 196 | } |
| 197 | |
| 198 | offset = end_tbs; /* skip the rest of v3 data */ |
| 199 | if (asn1_skip_obj(cert, &offset, ASN1_SEQUENCE) || |
| 200 | asn1_signature(cert, &offset, x509_ctx)) |
| 201 | goto end_cert; |
| 202 | #endif |
| 203 | ret = X509_OK; |
| 204 | end_cert: |
| 205 | if (len) |
| 206 | { |
| 207 | *len = cert_size; |
| 208 | } |
| 209 | |
| 210 | if (ret) |
| 211 | { |
| 212 | #ifdef CONFIG_SSL_FULL_MODE |
| 213 | printf("Error: Invalid X509 ASN.1 file (%s)\n" , |
| 214 | x509_display_error(ret)); |
| 215 | #endif |
| 216 | x509_free(x509_ctx); |
| 217 | *ctx = NULL; |
| 218 | } |
| 219 | |
| 220 | return ret; |
| 221 | } |
| 222 | |
| 223 | #ifdef CONFIG_SSL_CERT_VERIFICATION /* only care if doing verification */ |
| 224 | static int x509_v3_subject_alt_name(const uint8_t *cert, int offset, |
| 225 | X509_CTX *x509_ctx) |
| 226 | { |
| 227 | if ((offset = asn1_is_subject_alt_name(cert, offset)) > 0) |
| 228 | { |
| 229 | x509_ctx->subject_alt_name_present = true; |
| 230 | x509_ctx->subject_alt_name_is_critical = |
| 231 | asn1_is_critical_ext(cert, &offset); |
| 232 | |
| 233 | if (asn1_next_obj(cert, &offset, ASN1_OCTET_STRING) > 0) |
| 234 | { |
| 235 | int altlen; |
| 236 | |
| 237 | if ((altlen = asn1_next_obj(cert, &offset, ASN1_SEQUENCE)) > 0) |
| 238 | { |
| 239 | int endalt = offset + altlen; |
| 240 | int totalnames = 0; |
| 241 | |
| 242 | while (offset < endalt) |
| 243 | { |
| 244 | int type = cert[offset++]; |
| 245 | int dnslen = get_asn1_length(cert, &offset); |
| 246 | |
| 247 | if (type == ASN1_CONTEXT_DNSNAME) |
| 248 | { |
| 249 | x509_ctx->subject_alt_dnsnames = (char**) |
| 250 | realloc(x509_ctx->subject_alt_dnsnames, |
| 251 | (totalnames + 2) * sizeof(char*)); |
| 252 | x509_ctx->subject_alt_dnsnames[totalnames] = |
| 253 | (char*)malloc(dnslen + 1); |
| 254 | x509_ctx->subject_alt_dnsnames[totalnames+1] = NULL; |
| 255 | memcpy(x509_ctx->subject_alt_dnsnames[totalnames], |
| 256 | cert + offset, dnslen); |
| 257 | x509_ctx->subject_alt_dnsnames[totalnames][dnslen] = 0; |
| 258 | totalnames++; |
| 259 | } |
| 260 | |
| 261 | offset += dnslen; |
| 262 | } |
| 263 | } |
| 264 | } |
| 265 | } |
| 266 | |
| 267 | return X509_OK; |
| 268 | } |
| 269 | |
| 270 | /** |
| 271 | * Basic constraints - see https://tools.ietf.org/html/rfc5280#page-39 |
| 272 | */ |
| 273 | static int x509_v3_basic_constraints(const uint8_t *cert, int offset, |
| 274 | X509_CTX *x509_ctx) |
| 275 | { |
| 276 | int ret = X509_OK; |
| 277 | |
| 278 | if ((offset = asn1_is_basic_constraints(cert, offset)) == 0) |
| 279 | goto end_contraints; |
| 280 | |
| 281 | x509_ctx->basic_constraint_present = true; |
| 282 | x509_ctx->basic_constraint_is_critical = |
| 283 | asn1_is_critical_ext(cert, &offset); |
| 284 | |
| 285 | if (asn1_next_obj(cert, &offset, ASN1_OCTET_STRING) < 0 || |
| 286 | asn1_next_obj(cert, &offset, ASN1_SEQUENCE) < 0 || |
| 287 | asn1_get_bool(cert, &offset, &x509_ctx->basic_constraint_cA) < 0 || |
| 288 | asn1_get_int(cert, &offset, |
| 289 | &x509_ctx->basic_constraint_pathLenConstraint) < 0) |
| 290 | { |
| 291 | ret = X509_NOT_OK; |
| 292 | } |
| 293 | |
| 294 | end_contraints: |
| 295 | return ret; |
| 296 | } |
| 297 | |
| 298 | /* |
| 299 | * Key usage - see https://tools.ietf.org/html/rfc5280#section-4.2.1.3 |
| 300 | */ |
| 301 | static int x509_v3_key_usage(const uint8_t *cert, int offset, |
| 302 | X509_CTX *x509_ctx) |
| 303 | { |
| 304 | int ret = X509_OK; |
| 305 | |
| 306 | if ((offset = asn1_is_key_usage(cert, offset)) == 0) |
| 307 | goto end_key_usage; |
| 308 | |
| 309 | x509_ctx->key_usage_present = true; |
| 310 | x509_ctx->key_usage_is_critical = asn1_is_critical_ext(cert, &offset); |
| 311 | |
| 312 | if (asn1_next_obj(cert, &offset, ASN1_OCTET_STRING) < 0 || |
| 313 | asn1_get_bit_string_as_int(cert, &offset, &x509_ctx->key_usage)) |
| 314 | { |
| 315 | ret = X509_NOT_OK; |
| 316 | } |
| 317 | |
| 318 | end_key_usage: |
| 319 | return ret; |
| 320 | } |
| 321 | #endif |
| 322 | |
| 323 | /** |
| 324 | * Free an X.509 object's resources. |
| 325 | */ |
| 326 | void x509_free(X509_CTX *x509_ctx) |
| 327 | { |
| 328 | X509_CTX *next; |
| 329 | int i; |
| 330 | |
| 331 | if (x509_ctx == NULL) /* if already null, then don't bother */ |
| 332 | return; |
| 333 | |
| 334 | for (i = 0; i < X509_NUM_DN_TYPES; i++) |
| 335 | { |
| 336 | free(x509_ctx->ca_cert_dn[i]); |
| 337 | free(x509_ctx->cert_dn[i]); |
| 338 | } |
| 339 | |
| 340 | free(x509_ctx->signature); |
| 341 | |
| 342 | #ifdef CONFIG_SSL_CERT_VERIFICATION |
| 343 | if (x509_ctx->digest) |
| 344 | { |
| 345 | bi_free(x509_ctx->rsa_ctx->bi_ctx, x509_ctx->digest); |
| 346 | } |
| 347 | |
| 348 | if (x509_ctx->subject_alt_dnsnames) |
| 349 | { |
| 350 | for (i = 0; x509_ctx->subject_alt_dnsnames[i]; ++i) |
| 351 | free(x509_ctx->subject_alt_dnsnames[i]); |
| 352 | |
| 353 | free(x509_ctx->subject_alt_dnsnames); |
| 354 | } |
| 355 | #endif |
| 356 | |
| 357 | RSA_free(x509_ctx->rsa_ctx); |
| 358 | next = x509_ctx->next; |
| 359 | free(x509_ctx); |
| 360 | x509_free(next); /* clear the chain */ |
| 361 | } |
| 362 | |
| 363 | #ifdef CONFIG_SSL_CERT_VERIFICATION |
| 364 | /** |
| 365 | * Take a signature and decrypt it. |
| 366 | */ |
| 367 | static bigint *sig_verify(BI_CTX *ctx, const uint8_t *sig, int sig_len, |
| 368 | bigint *modulus, bigint *pub_exp) |
| 369 | { |
| 370 | int i, size; |
| 371 | bigint *decrypted_bi, *dat_bi; |
| 372 | bigint *bir = NULL; |
| 373 | uint8_t *block = (uint8_t *)alloca(sig_len); |
| 374 | |
| 375 | /* decrypt */ |
| 376 | dat_bi = bi_import(ctx, sig, sig_len); |
| 377 | ctx->mod_offset = BIGINT_M_OFFSET; |
| 378 | |
| 379 | /* convert to a normal block */ |
| 380 | decrypted_bi = bi_mod_power2(ctx, dat_bi, modulus, pub_exp); |
| 381 | |
| 382 | bi_export(ctx, decrypted_bi, block, sig_len); |
| 383 | ctx->mod_offset = BIGINT_M_OFFSET; |
| 384 | |
| 385 | i = 10; /* start at the first possible non-padded byte */ |
| 386 | while (block[i++] && i < sig_len); |
| 387 | size = sig_len - i; |
| 388 | |
| 389 | /* get only the bit we want */ |
| 390 | if (size > 0) |
| 391 | { |
| 392 | int len; |
| 393 | const uint8_t *sig_ptr = get_signature(&block[i], &len); |
| 394 | |
| 395 | if (sig_ptr) |
| 396 | { |
| 397 | bir = bi_import(ctx, sig_ptr, len); |
| 398 | } |
| 399 | } |
| 400 | |
| 401 | /* save a few bytes of memory */ |
| 402 | bi_clear_cache(ctx); |
| 403 | return bir; |
| 404 | } |
| 405 | |
| 406 | /** |
| 407 | * Do some basic checks on the certificate chain. |
| 408 | * |
| 409 | * Certificate verification consists of a number of checks: |
| 410 | * - The date of the certificate is after the start date. |
| 411 | * - The date of the certificate is before the finish date. |
| 412 | * - A root certificate exists in the certificate store. |
| 413 | * - That the certificate(s) are not self-signed. |
| 414 | * - The certificate chain is valid. |
| 415 | * - The signature of the certificate is valid. |
| 416 | * - Basic constraints |
| 417 | */ |
| 418 | int x509_verify(const CA_CERT_CTX *ca_cert_ctx, const X509_CTX *cert, |
| 419 | int *pathLenConstraint) |
| 420 | { |
| 421 | int ret = X509_OK, i = 0; |
| 422 | bigint *cert_sig; |
| 423 | X509_CTX *next_cert = NULL; |
| 424 | BI_CTX *ctx = NULL; |
| 425 | bigint *mod = NULL, *expn = NULL; |
| 426 | int match_ca_cert = 0; |
| 427 | struct timeval tv; |
| 428 | uint8_t is_self_signed = 0; |
| 429 | |
| 430 | if (cert == NULL) |
| 431 | { |
| 432 | ret = X509_VFY_ERROR_NO_TRUSTED_CERT; |
| 433 | goto end_verify; |
| 434 | } |
| 435 | |
| 436 | /* a self-signed certificate that is not in the CA store - use this |
| 437 | to check the signature */ |
| 438 | if (asn1_compare_dn(cert->ca_cert_dn, cert->cert_dn) == 0) |
| 439 | { |
| 440 | is_self_signed = 1; |
| 441 | ctx = cert->rsa_ctx->bi_ctx; |
| 442 | mod = cert->rsa_ctx->m; |
| 443 | expn = cert->rsa_ctx->e; |
| 444 | } |
| 445 | |
| 446 | gettimeofday(&tv, NULL); |
| 447 | |
| 448 | /* check the not before date */ |
| 449 | if (tv.tv_sec < cert->not_before) |
| 450 | { |
| 451 | ret = X509_VFY_ERROR_NOT_YET_VALID; |
| 452 | goto end_verify; |
| 453 | } |
| 454 | |
| 455 | /* check the not after date */ |
| 456 | if (tv.tv_sec > cert->not_after) |
| 457 | { |
| 458 | ret = X509_VFY_ERROR_EXPIRED; |
| 459 | goto end_verify; |
| 460 | } |
| 461 | |
| 462 | if (cert->basic_constraint_present) |
| 463 | { |
| 464 | /* If the cA boolean is not asserted, |
| 465 | then the keyCertSign bit in the key usage extension MUST NOT be |
| 466 | asserted. */ |
| 467 | if (!cert->basic_constraint_cA && |
| 468 | IS_SET_KEY_USAGE_FLAG(cert, KEY_USAGE_KEY_CERT_SIGN)) |
| 469 | { |
| 470 | ret = X509_VFY_ERROR_BASIC_CONSTRAINT; |
| 471 | goto end_verify; |
| 472 | } |
| 473 | |
| 474 | /* The pathLenConstraint field is meaningful only if the cA boolean is |
| 475 | asserted and the key usage extension, if present, asserts the |
| 476 | keyCertSign bit. In this case, it gives the maximum number of |
| 477 | non-self-issued intermediate certificates that may follow this |
| 478 | certificate in a valid certification path. */ |
| 479 | if (cert->basic_constraint_cA && |
| 480 | (!cert->key_usage_present || |
| 481 | IS_SET_KEY_USAGE_FLAG(cert, KEY_USAGE_KEY_CERT_SIGN)) && |
| 482 | (cert->basic_constraint_pathLenConstraint+1) < *pathLenConstraint) |
| 483 | { |
| 484 | ret = X509_VFY_ERROR_BASIC_CONSTRAINT; |
| 485 | goto end_verify; |
| 486 | } |
| 487 | } |
| 488 | |
| 489 | next_cert = cert->next; |
| 490 | |
| 491 | /* last cert in the chain - look for a trusted cert */ |
| 492 | if (next_cert == NULL) |
| 493 | { |
| 494 | if (ca_cert_ctx != NULL) |
| 495 | { |
| 496 | /* go thru the CA store */ |
| 497 | while (i < CONFIG_X509_MAX_CA_CERTS && ca_cert_ctx->cert[i]) |
| 498 | { |
| 499 | /* the extension is present but the cA boolean is not |
| 500 | asserted, then the certified public key MUST NOT be used |
| 501 | to verify certificate signatures. */ |
| 502 | if (cert->basic_constraint_present && |
| 503 | !ca_cert_ctx->cert[i]->basic_constraint_cA) |
| 504 | continue; |
| 505 | |
| 506 | if (asn1_compare_dn(cert->ca_cert_dn, |
| 507 | ca_cert_ctx->cert[i]->cert_dn) == 0) |
| 508 | { |
| 509 | /* use this CA certificate for signature verification */ |
| 510 | match_ca_cert = true; |
| 511 | ctx = ca_cert_ctx->cert[i]->rsa_ctx->bi_ctx; |
| 512 | mod = ca_cert_ctx->cert[i]->rsa_ctx->m; |
| 513 | expn = ca_cert_ctx->cert[i]->rsa_ctx->e; |
| 514 | |
| 515 | |
| 516 | break; |
| 517 | } |
| 518 | |
| 519 | i++; |
| 520 | } |
| 521 | } |
| 522 | |
| 523 | /* couldn't find a trusted cert (& let self-signed errors |
| 524 | be returned) */ |
| 525 | if (!match_ca_cert && !is_self_signed) |
| 526 | { |
| 527 | ret = X509_VFY_ERROR_NO_TRUSTED_CERT; |
| 528 | goto end_verify; |
| 529 | } |
| 530 | } |
| 531 | else if (asn1_compare_dn(cert->ca_cert_dn, next_cert->cert_dn) != 0) |
| 532 | { |
| 533 | /* check the chain */ |
| 534 | ret = X509_VFY_ERROR_INVALID_CHAIN; |
| 535 | goto end_verify; |
| 536 | } |
| 537 | else /* use the next certificate in the chain for signature verify */ |
| 538 | { |
| 539 | ctx = next_cert->rsa_ctx->bi_ctx; |
| 540 | mod = next_cert->rsa_ctx->m; |
| 541 | expn = next_cert->rsa_ctx->e; |
| 542 | } |
| 543 | |
| 544 | /* cert is self signed */ |
| 545 | if (!match_ca_cert && is_self_signed) |
| 546 | { |
| 547 | ret = X509_VFY_ERROR_SELF_SIGNED; |
| 548 | goto end_verify; |
| 549 | } |
| 550 | |
| 551 | /* check the signature */ |
| 552 | cert_sig = sig_verify(ctx, cert->signature, cert->sig_len, |
| 553 | bi_clone(ctx, mod), bi_clone(ctx, expn)); |
| 554 | |
| 555 | if (cert_sig && cert->digest) |
| 556 | { |
| 557 | if (bi_compare(cert_sig, cert->digest) != 0) |
| 558 | ret = X509_VFY_ERROR_BAD_SIGNATURE; |
| 559 | |
| 560 | |
| 561 | bi_free(ctx, cert_sig); |
| 562 | } |
| 563 | else |
| 564 | { |
| 565 | ret = X509_VFY_ERROR_BAD_SIGNATURE; |
| 566 | } |
| 567 | |
| 568 | if (ret) |
| 569 | goto end_verify; |
| 570 | |
| 571 | /* go down the certificate chain using recursion. */ |
| 572 | if (next_cert != NULL) |
| 573 | { |
| 574 | (*pathLenConstraint)++; /* don't include last certificate */ |
| 575 | ret = x509_verify(ca_cert_ctx, next_cert, pathLenConstraint); |
| 576 | } |
| 577 | |
| 578 | end_verify: |
| 579 | return ret; |
| 580 | } |
| 581 | #endif |
| 582 | |
| 583 | #if defined (CONFIG_SSL_FULL_MODE) |
| 584 | /** |
| 585 | * Used for diagnostics. |
| 586 | */ |
| 587 | static const char *not_part_of_cert = "<Not Part Of Certificate>" ; |
| 588 | void x509_print(const X509_CTX *cert, CA_CERT_CTX *ca_cert_ctx) |
| 589 | { |
| 590 | if (cert == NULL) |
| 591 | return; |
| 592 | |
| 593 | printf("=== CERTIFICATE ISSUED TO ===\n" ); |
| 594 | printf("Common Name (CN):\t\t" ); |
| 595 | printf("%s\n" , cert->cert_dn[X509_COMMON_NAME] ? |
| 596 | cert->cert_dn[X509_COMMON_NAME] : not_part_of_cert); |
| 597 | |
| 598 | printf("Organization (O):\t\t" ); |
| 599 | printf("%s\n" , cert->cert_dn[X509_ORGANIZATION] ? |
| 600 | cert->cert_dn[X509_ORGANIZATION] : not_part_of_cert); |
| 601 | |
| 602 | if (cert->cert_dn[X509_ORGANIZATIONAL_UNIT]) |
| 603 | { |
| 604 | printf("Organizational Unit (OU):\t" ); |
| 605 | printf("%s\n" , cert->cert_dn[X509_ORGANIZATIONAL_UNIT]); |
| 606 | } |
| 607 | |
| 608 | if (cert->cert_dn[X509_LOCATION]) |
| 609 | { |
| 610 | printf("Location (L):\t\t\t" ); |
| 611 | printf("%s\n" , cert->cert_dn[X509_LOCATION]); |
| 612 | } |
| 613 | |
| 614 | if (cert->cert_dn[X509_COUNTRY]) |
| 615 | { |
| 616 | printf("Country (C):\t\t\t" ); |
| 617 | printf("%s\n" , cert->cert_dn[X509_COUNTRY]); |
| 618 | } |
| 619 | |
| 620 | if (cert->cert_dn[X509_STATE]) |
| 621 | { |
| 622 | printf("State (ST):\t\t\t" ); |
| 623 | printf("%s\n" , cert->cert_dn[X509_STATE]); |
| 624 | } |
| 625 | |
| 626 | if (cert->basic_constraint_present) |
| 627 | { |
| 628 | printf("Basic Constraints:\t\t%sCA:%s, pathlen:%d\n" , |
| 629 | cert->basic_constraint_is_critical ? |
| 630 | "critical, " : "" , |
| 631 | cert->basic_constraint_cA? "TRUE" : "FALSE" , |
| 632 | cert->basic_constraint_pathLenConstraint); |
| 633 | } |
| 634 | |
| 635 | if (cert->key_usage_present) |
| 636 | { |
| 637 | printf("Key Usage:\t\t\t%s" , cert->key_usage_is_critical ? |
| 638 | "critical, " : "" ); |
| 639 | bool has_started = false; |
| 640 | |
| 641 | if (IS_SET_KEY_USAGE_FLAG(cert, KEY_USAGE_DIGITAL_SIGNATURE)) |
| 642 | { |
| 643 | printf("Digital Signature" ); |
| 644 | has_started = true; |
| 645 | } |
| 646 | |
| 647 | if (IS_SET_KEY_USAGE_FLAG(cert, KEY_USAGE_NON_REPUDIATION)) |
| 648 | { |
| 649 | if (has_started) |
| 650 | printf(", " ); |
| 651 | |
| 652 | printf("Non Repudiation" ); |
| 653 | has_started = true; |
| 654 | } |
| 655 | |
| 656 | if (IS_SET_KEY_USAGE_FLAG(cert, KEY_USAGE_KEY_ENCIPHERMENT)) |
| 657 | { |
| 658 | if (has_started) |
| 659 | printf(", " ); |
| 660 | |
| 661 | printf("Key Encipherment" ); |
| 662 | has_started = true; |
| 663 | } |
| 664 | |
| 665 | if (IS_SET_KEY_USAGE_FLAG(cert, KEY_USAGE_DATA_ENCIPHERMENT)) |
| 666 | { |
| 667 | if (has_started) |
| 668 | printf(", " ); |
| 669 | |
| 670 | printf("Data Encipherment" ); |
| 671 | has_started = true; |
| 672 | } |
| 673 | |
| 674 | if (IS_SET_KEY_USAGE_FLAG(cert, KEY_USAGE_KEY_AGREEMENT)) |
| 675 | { |
| 676 | if (has_started) |
| 677 | printf(", " ); |
| 678 | |
| 679 | printf("Key Agreement" ); |
| 680 | has_started = true; |
| 681 | } |
| 682 | |
| 683 | if (IS_SET_KEY_USAGE_FLAG(cert, KEY_USAGE_KEY_CERT_SIGN)) |
| 684 | { |
| 685 | if (has_started) |
| 686 | printf(", " ); |
| 687 | |
| 688 | printf("Key Cert Sign" ); |
| 689 | has_started = true; |
| 690 | } |
| 691 | |
| 692 | if (IS_SET_KEY_USAGE_FLAG(cert, KEY_USAGE_CRL_SIGN)) |
| 693 | { |
| 694 | if (has_started) |
| 695 | printf(", " ); |
| 696 | |
| 697 | printf("CRL Sign" ); |
| 698 | has_started = true; |
| 699 | } |
| 700 | |
| 701 | if (IS_SET_KEY_USAGE_FLAG(cert, KEY_USAGE_ENCIPHER_ONLY)) |
| 702 | { |
| 703 | if (has_started) |
| 704 | printf(", " ); |
| 705 | |
| 706 | printf("Encipher Only" ); |
| 707 | has_started = true; |
| 708 | } |
| 709 | |
| 710 | if (IS_SET_KEY_USAGE_FLAG(cert, KEY_USAGE_DECIPHER_ONLY)) |
| 711 | { |
| 712 | if (has_started) |
| 713 | printf(", " ); |
| 714 | |
| 715 | printf("Decipher Only" ); |
| 716 | has_started = true; |
| 717 | } |
| 718 | |
| 719 | printf("\n" ); |
| 720 | } |
| 721 | |
| 722 | if (cert->subject_alt_name_present) |
| 723 | { |
| 724 | printf("Subject Alt Name:\t\t%s" , cert->subject_alt_name_is_critical |
| 725 | ? "critical, " : "" ); |
| 726 | if (cert->subject_alt_dnsnames) |
| 727 | { |
| 728 | int i = 0; |
| 729 | |
| 730 | while (cert->subject_alt_dnsnames[i]) |
| 731 | printf("%s " , cert->subject_alt_dnsnames[i++]); |
| 732 | } |
| 733 | printf("\n" ); |
| 734 | |
| 735 | } |
| 736 | |
| 737 | printf("=== CERTIFICATE ISSUED BY ===\n" ); |
| 738 | printf("Common Name (CN):\t\t" ); |
| 739 | printf("%s\n" , cert->ca_cert_dn[X509_COMMON_NAME] ? |
| 740 | cert->ca_cert_dn[X509_COMMON_NAME] : not_part_of_cert); |
| 741 | |
| 742 | printf("Organization (O):\t\t" ); |
| 743 | printf("%s\n" , cert->ca_cert_dn[X509_ORGANIZATION] ? |
| 744 | cert->ca_cert_dn[X509_ORGANIZATION] : not_part_of_cert); |
| 745 | |
| 746 | if (cert->ca_cert_dn[X509_ORGANIZATIONAL_UNIT]) |
| 747 | { |
| 748 | printf("Organizational Unit (OU):\t" ); |
| 749 | printf("%s\n" , cert->ca_cert_dn[X509_ORGANIZATIONAL_UNIT]); |
| 750 | } |
| 751 | |
| 752 | if (cert->ca_cert_dn[X509_LOCATION]) |
| 753 | { |
| 754 | printf("Location (L):\t\t\t" ); |
| 755 | printf("%s\n" , cert->ca_cert_dn[X509_LOCATION]); |
| 756 | } |
| 757 | |
| 758 | if (cert->ca_cert_dn[X509_COUNTRY]) |
| 759 | { |
| 760 | printf("Country (C):\t\t\t" ); |
| 761 | printf("%s\n" , cert->ca_cert_dn[X509_COUNTRY]); |
| 762 | } |
| 763 | |
| 764 | if (cert->ca_cert_dn[X509_STATE]) |
| 765 | { |
| 766 | printf("State (ST):\t\t\t" ); |
| 767 | printf("%s\n" , cert->ca_cert_dn[X509_STATE]); |
| 768 | } |
| 769 | |
| 770 | printf("Not Before:\t\t\t%s" , ctime(&cert->not_before)); |
| 771 | printf("Not After:\t\t\t%s" , ctime(&cert->not_after)); |
| 772 | printf("RSA bitsize:\t\t\t%d\n" , cert->rsa_ctx->num_octets*8); |
| 773 | printf("Sig Type:\t\t\t" ); |
| 774 | switch (cert->sig_type) |
| 775 | { |
| 776 | case SIG_TYPE_MD5: |
| 777 | printf("MD5\n" ); |
| 778 | break; |
| 779 | case SIG_TYPE_SHA1: |
| 780 | printf("SHA1\n" ); |
| 781 | break; |
| 782 | case SIG_TYPE_SHA256: |
| 783 | printf("SHA256\n" ); |
| 784 | break; |
| 785 | case SIG_TYPE_SHA384: |
| 786 | printf("SHA384\n" ); |
| 787 | break; |
| 788 | case SIG_TYPE_SHA512: |
| 789 | printf("SHA512\n" ); |
| 790 | break; |
| 791 | default: |
| 792 | printf("Unrecognized: %d\n" , cert->sig_type); |
| 793 | break; |
| 794 | } |
| 795 | |
| 796 | if (ca_cert_ctx) |
| 797 | { |
| 798 | int pathLenConstraint = 0; |
| 799 | printf("Verify:\t\t\t\t%s\n" , |
| 800 | x509_display_error(x509_verify(ca_cert_ctx, cert, |
| 801 | &pathLenConstraint))); |
| 802 | } |
| 803 | |
| 804 | #if 0 |
| 805 | print_blob("Signature" , cert->signature, cert->sig_len); |
| 806 | bi_print("Modulus" , cert->rsa_ctx->m); |
| 807 | bi_print("Pub Exp" , cert->rsa_ctx->e); |
| 808 | #endif |
| 809 | |
| 810 | if (ca_cert_ctx) |
| 811 | { |
| 812 | x509_print(cert->next, ca_cert_ctx); |
| 813 | } |
| 814 | |
| 815 | TTY_FLUSH(); |
| 816 | } |
| 817 | #endif |
| 818 | |
| 819 | const char * x509_display_error(int error) |
| 820 | { |
| 821 | switch (error) |
| 822 | { |
| 823 | case X509_OK: |
| 824 | return "Certificate verify successful" ; |
| 825 | |
| 826 | case X509_NOT_OK: |
| 827 | return "X509 not ok" ; |
| 828 | |
| 829 | case X509_VFY_ERROR_NO_TRUSTED_CERT: |
| 830 | return "No trusted cert is available" ; |
| 831 | |
| 832 | case X509_VFY_ERROR_BAD_SIGNATURE: |
| 833 | return "Bad signature" ; |
| 834 | |
| 835 | case X509_VFY_ERROR_NOT_YET_VALID: |
| 836 | return "Cert is not yet valid" ; |
| 837 | |
| 838 | case X509_VFY_ERROR_EXPIRED: |
| 839 | return "Cert has expired" ; |
| 840 | |
| 841 | case X509_VFY_ERROR_SELF_SIGNED: |
| 842 | return "Cert is self-signed" ; |
| 843 | |
| 844 | case X509_VFY_ERROR_INVALID_CHAIN: |
| 845 | return "Chain is invalid (check order of certs)" ; |
| 846 | |
| 847 | case X509_VFY_ERROR_UNSUPPORTED_DIGEST: |
| 848 | return "Unsupported digest" ; |
| 849 | |
| 850 | case X509_INVALID_PRIV_KEY: |
| 851 | return "Invalid private key" ; |
| 852 | |
| 853 | case X509_VFY_ERROR_BASIC_CONSTRAINT: |
| 854 | return "Basic constraint invalid" ; |
| 855 | |
| 856 | default: |
| 857 | return "Unknown" ; |
| 858 | } |
| 859 | } |
| 860 | //#endif /* CONFIG_SSL_FULL_MODE */ |
| 861 | |
| 862 | |