| 1 | #include <stdio.h> |
| 2 | #include <string.h> |
| 3 | #include <stdint.h> |
| 4 | |
| 5 | #include <openssl/opensslv.h> |
| 6 | #include <openssl/err.h> |
| 7 | #include <openssl/crypto.h> |
| 8 | #include <openssl/safestack.h> |
| 9 | #include <openssl/objects.h> |
| 10 | #include <openssl/x509.h> |
| 11 | #include <openssl/x509v3.h> |
| 12 | #include <openssl/evp.h> |
| 13 | |
| 14 | #if OPENSSL_VERSION_NUMBER < 0x1000000fL |
| 15 | # error "OpenSSL 1.0.0 or higher required" |
| 16 | #else /* remainder of file */ |
| 17 | |
| 18 | #include "danessl.h" |
| 19 | |
| 20 | #define DANE_F_ADD_SKID 100 |
| 21 | #define DANE_F_CHECK_END_ENTITY 101 |
| 22 | #define DANE_F_GROW_CHAIN 102 |
| 23 | #define DANE_F_LIST_ALLOC 103 |
| 24 | #define DANE_F_MATCH 104 |
| 25 | #define DANE_F_PUSH_EXT 105 |
| 26 | #define DANE_F_SET_TRUST_ANCHOR 106 |
| 27 | #define DANE_F_SSL_CTX_DANE_INIT 107 |
| 28 | #define DANE_F_SSL_DANE_ADD_TLSA 108 |
| 29 | #define DANE_F_SSL_DANE_INIT 109 |
| 30 | #define DANE_F_SSL_DANE_LIBRARY_INIT 110 |
| 31 | #define DANE_F_VERIFY_CERT 111 |
| 32 | #define DANE_F_WRAP_CERT 112 |
| 33 | |
| 34 | #define DANE_R_BAD_CERT 100 |
| 35 | #define DANE_R_BAD_CERT_PKEY 101 |
| 36 | #define DANE_R_BAD_DATA_LENGTH 102 |
| 37 | #define DANE_R_BAD_DIGEST 103 |
| 38 | #define DANE_R_BAD_NULL_DATA 104 |
| 39 | #define DANE_R_BAD_PKEY 105 |
| 40 | #define DANE_R_BAD_SELECTOR 106 |
| 41 | #define DANE_R_BAD_USAGE 107 |
| 42 | #define DANE_R_DANE_INIT 108 |
| 43 | #define DANE_R_DANE_SUPPORT 109 |
| 44 | #define DANE_R_LIBRARY_INIT 110 |
| 45 | #define DANE_R_NOSIGN_KEY 111 |
| 46 | #define DANE_R_SCTX_INIT 112 |
| 47 | |
| 48 | #ifndef OPENSSL_NO_ERR |
| 49 | # define DANE_F_PLACEHOLDER 0 /* FIRST! Value TBD */ |
| 50 | static ERR_STRING_DATA dane_str_functs[] = |
| 51 | { |
| 52 | {DANE_F_PLACEHOLDER, "DANE library"}, /* FIRST!!! */ |
| 53 | {DANE_F_ADD_SKID, "add_skid"}, |
| 54 | {DANE_F_CHECK_END_ENTITY, "check_end_entity"}, |
| 55 | {DANE_F_GROW_CHAIN, "grow_chain"}, |
| 56 | {DANE_F_LIST_ALLOC, "list_alloc"}, |
| 57 | {DANE_F_MATCH, "match"}, |
| 58 | {DANE_F_PUSH_EXT, "push_ext"}, |
| 59 | {DANE_F_SET_TRUST_ANCHOR, "set_trust_anchor"}, |
| 60 | {DANE_F_SSL_CTX_DANE_INIT, "SSL_CTX_dane_init"}, |
| 61 | {DANE_F_SSL_DANE_ADD_TLSA, "SSL_dane_add_tlsa"}, |
| 62 | {DANE_F_SSL_DANE_INIT, "SSL_dane_init"}, |
| 63 | {DANE_F_SSL_DANE_LIBRARY_INIT, "SSL_dane_library_init"}, |
| 64 | {DANE_F_VERIFY_CERT, "verify_cert"}, |
| 65 | {DANE_F_WRAP_CERT, "wrap_cert"}, |
| 66 | {0, NULL} |
| 67 | }; |
| 68 | static ERR_STRING_DATA dane_str_reasons[] = |
| 69 | { |
| 70 | {DANE_R_BAD_CERT, "Bad TLSA record certificate"}, |
| 71 | {DANE_R_BAD_CERT_PKEY, "Bad TLSA record certificate public key"}, |
| 72 | {DANE_R_BAD_DATA_LENGTH, "Bad TLSA record digest length"}, |
| 73 | {DANE_R_BAD_DIGEST, "Bad TLSA record digest"}, |
| 74 | {DANE_R_BAD_NULL_DATA, "Bad TLSA record null data"}, |
| 75 | {DANE_R_BAD_PKEY, "Bad TLSA record public key"}, |
| 76 | {DANE_R_BAD_SELECTOR, "Bad TLSA record selector"}, |
| 77 | {DANE_R_BAD_USAGE, "Bad TLSA record usage"}, |
| 78 | {DANE_R_DANE_INIT, "SSL_dane_init() required"}, |
| 79 | {DANE_R_DANE_SUPPORT, "DANE library features not supported"}, |
| 80 | {DANE_R_LIBRARY_INIT, "SSL_dane_library_init() required"}, |
| 81 | {DANE_R_SCTX_INIT, "SSL_CTX_dane_init() required"}, |
| 82 | {DANE_R_NOSIGN_KEY, "Certificate usage 2 requires EC support"}, |
| 83 | {0, NULL} |
| 84 | }; |
| 85 | #endif /*OPENSSL_NO_ERR*/ |
| 86 | |
| 87 | #define DANEerr(f, r) ERR_PUT_error(err_lib_dane, (f), (r), __FILE__, __LINE__) |
| 88 | |
| 89 | static int err_lib_dane = -1; |
| 90 | static int dane_idx = -1; |
| 91 | |
| 92 | #ifdef X509_V_FLAG_PARTIAL_CHAIN /* OpenSSL >= 1.0.2 */ |
| 93 | static int wrap_to_root = 0; |
| 94 | #else |
| 95 | static int wrap_to_root = 1; |
| 96 | #endif |
| 97 | |
| 98 | static void (*cert_free)(void *) = (void (*)(void *)) X509_free; |
| 99 | static void (*pkey_free)(void *) = (void (*)(void *)) EVP_PKEY_free; |
| 100 | |
| 101 | typedef struct dane_list |
| 102 | { |
| 103 | struct dane_list *next; |
| 104 | void *value; |
| 105 | } *dane_list; |
| 106 | |
| 107 | #define LINSERT(h, e) do { (e)->next = (h); (h) = (e); } while (0) |
| 108 | |
| 109 | typedef struct dane_host_list |
| 110 | { |
| 111 | struct dane_host_list *next; |
| 112 | char *value; |
| 113 | } *dane_host_list; |
| 114 | |
| 115 | typedef struct dane_data |
| 116 | { |
| 117 | size_t datalen; |
| 118 | unsigned char data[0]; |
| 119 | } *dane_data; |
| 120 | |
| 121 | typedef struct dane_data_list |
| 122 | { |
| 123 | struct dane_data_list *next; |
| 124 | dane_data value; |
| 125 | } *dane_data_list; |
| 126 | |
| 127 | typedef struct dane_mtype |
| 128 | { |
| 129 | int mdlen; |
| 130 | const EVP_MD *md; |
| 131 | dane_data_list data; |
| 132 | } *dane_mtype; |
| 133 | |
| 134 | typedef struct dane_mtype_list |
| 135 | { |
| 136 | struct dane_mtype_list *next; |
| 137 | dane_mtype value; |
| 138 | } *dane_mtype_list; |
| 139 | |
| 140 | typedef struct dane_selector |
| 141 | { |
| 142 | uint8_t selector; |
| 143 | dane_mtype_list mtype; |
| 144 | } *dane_selector; |
| 145 | |
| 146 | typedef struct dane_selector_list |
| 147 | { |
| 148 | struct dane_selector_list *next; |
| 149 | dane_selector value; |
| 150 | } *dane_selector_list; |
| 151 | |
| 152 | typedef struct dane_pkey_list |
| 153 | { |
| 154 | struct dane_pkey_list *next; |
| 155 | EVP_PKEY *value; |
| 156 | } *dane_pkey_list; |
| 157 | |
| 158 | typedef struct dane_cert_list |
| 159 | { |
| 160 | struct dane_cert_list *next; |
| 161 | X509 *value; |
| 162 | } *dane_cert_list; |
| 163 | |
| 164 | typedef struct ssl_dane |
| 165 | { |
| 166 | int (*verify)(X509_STORE_CTX *); |
| 167 | STACK_OF(X509) *roots; |
| 168 | STACK_OF(X509) *chain; |
| 169 | const char *thost; /* TLSA base domain */ |
| 170 | char *mhost; /* Matched, peer name */ |
| 171 | dane_pkey_list pkeys; |
| 172 | dane_cert_list certs; |
| 173 | dane_host_list hosts; |
| 174 | dane_selector_list selectors[SSL_DANE_USAGE_LAST + 1]; |
| 175 | int depth; |
| 176 | int multi; /* Multi-label wildcards? */ |
| 177 | int count; /* Number of TLSA records */ |
| 178 | } ssl_dane; |
| 179 | |
| 180 | #ifndef X509_V_ERR_HOSTNAME_MISMATCH |
| 181 | # define X509_V_ERR_HOSTNAME_MISMATCH X509_V_ERR_APPLICATION_VERIFICATION |
| 182 | #endif |
| 183 | |
| 184 | static int |
| 185 | match(dane_selector_list slist, X509 *cert, int depth) |
| 186 | { |
| 187 | int matched; |
| 188 | |
| 189 | /* |
| 190 | * Note, set_trust_anchor() needs to know whether the match was for a |
| 191 | * pkey digest or a certificate digest. We return MATCHED_PKEY or |
| 192 | * MATCHED_CERT accordingly. |
| 193 | */ |
| 194 | #define MATCHED_CERT (SSL_DANE_SELECTOR_CERT + 1) |
| 195 | #define MATCHED_PKEY (SSL_DANE_SELECTOR_SPKI + 1) |
| 196 | |
| 197 | /* |
| 198 | * Loop over each selector, mtype, and associated data element looking |
| 199 | * for a match. |
| 200 | */ |
| 201 | for(matched = 0; !matched && slist; slist = slist->next) |
| 202 | { |
| 203 | dane_mtype_list m; |
| 204 | unsigned char mdbuf[EVP_MAX_MD_SIZE]; |
| 205 | unsigned char *buf = NULL; |
| 206 | unsigned char *buf2; |
| 207 | unsigned int len = 0; |
| 208 | |
| 209 | /* |
| 210 | * Extract ASN.1 DER form of certificate or public key. |
| 211 | */ |
| 212 | switch(slist->value->selector) |
| 213 | { |
| 214 | case SSL_DANE_SELECTOR_CERT: |
| 215 | len = i2d_X509(cert, NULL); |
| 216 | buf2 = buf = (unsigned char *) OPENSSL_malloc(len); |
| 217 | if(buf) i2d_X509(cert, &buf2); |
| 218 | break; |
| 219 | case SSL_DANE_SELECTOR_SPKI: |
| 220 | len = i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), NULL); |
| 221 | buf2 = buf = (unsigned char *) OPENSSL_malloc(len); |
| 222 | if(buf) i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), &buf2); |
| 223 | break; |
| 224 | } |
| 225 | |
| 226 | if(!buf) |
| 227 | { |
| 228 | DANEerr(DANE_F_MATCH, ERR_R_MALLOC_FAILURE); |
| 229 | return 0; |
| 230 | } |
| 231 | OPENSSL_assert(buf2 - buf == len); |
| 232 | |
| 233 | /* |
| 234 | * Loop over each mtype and data element |
| 235 | */ |
| 236 | for(m = slist->value->mtype; !matched && m; m = m->next) |
| 237 | { |
| 238 | dane_data_list d; |
| 239 | unsigned char *cmpbuf = buf; |
| 240 | unsigned int cmplen = len; |
| 241 | |
| 242 | /* |
| 243 | * If it is a digest, compute the corresponding digest of the |
| 244 | * DER data for comparison, otherwise, use the full object. |
| 245 | */ |
| 246 | if(m->value->md) |
| 247 | { |
| 248 | cmpbuf = mdbuf; |
| 249 | if(!EVP_Digest(buf, len, cmpbuf, &cmplen, m->value->md, 0)) |
| 250 | matched = -1; |
| 251 | } |
| 252 | for(d = m->value->data; !matched && d; d = d->next) |
| 253 | if( cmplen == d->value->datalen |
| 254 | && memcmp(cmpbuf, d->value->data, cmplen) == 0) |
| 255 | matched = slist->value->selector + 1; |
| 256 | } |
| 257 | |
| 258 | OPENSSL_free(buf); |
| 259 | } |
| 260 | |
| 261 | return matched; |
| 262 | } |
| 263 | |
| 264 | static int |
| 265 | push_ext(X509 *cert, X509_EXTENSION *ext) |
| 266 | { |
| 267 | X509_EXTENSIONS *exts; |
| 268 | |
| 269 | if(ext) |
| 270 | { |
| 271 | if(!(exts = cert->cert_info->extensions)) |
| 272 | exts = cert->cert_info->extensions = sk_X509_EXTENSION_new_null(); |
| 273 | if (exts && sk_X509_EXTENSION_push(exts, ext)) |
| 274 | return 1; |
| 275 | X509_EXTENSION_free(ext); |
| 276 | } |
| 277 | DANEerr(DANE_F_PUSH_EXT, ERR_R_MALLOC_FAILURE); |
| 278 | return 0; |
| 279 | } |
| 280 | |
| 281 | static int |
| 282 | add_ext(X509 *issuer, X509 *subject, int ext_nid, char *ext_val) |
| 283 | { |
| 284 | X509V3_CTX v3ctx; |
| 285 | |
| 286 | X509V3_set_ctx(&v3ctx, issuer, subject, 0, 0, 0); |
| 287 | return push_ext(subject, X509V3_EXT_conf_nid(0, &v3ctx, ext_nid, ext_val)); |
| 288 | } |
| 289 | |
| 290 | static int |
| 291 | set_serial(X509 *cert, AUTHORITY_KEYID *akid, X509 *subject) |
| 292 | { |
| 293 | int ret = 0; |
| 294 | BIGNUM *bn; |
| 295 | |
| 296 | if(akid && akid->serial) |
| 297 | return (X509_set_serialNumber(cert, akid->serial)); |
| 298 | |
| 299 | /* |
| 300 | * Add one to subject's serial to avoid collisions between TA serial and |
| 301 | * serial of signing root. |
| 302 | */ |
| 303 | if( (bn = ASN1_INTEGER_to_BN(X509_get_serialNumber(subject), 0)) != 0 |
| 304 | && BN_add_word(bn, 1) |
| 305 | && BN_to_ASN1_INTEGER(bn, X509_get_serialNumber(cert))) |
| 306 | ret = 1; |
| 307 | |
| 308 | if(bn) |
| 309 | BN_free(bn); |
| 310 | return ret; |
| 311 | } |
| 312 | |
| 313 | static int |
| 314 | add_akid(X509 *cert, AUTHORITY_KEYID *akid) |
| 315 | { |
| 316 | int nid = NID_authority_key_identifier; |
| 317 | ASN1_STRING *id; |
| 318 | unsigned char c = 0; |
| 319 | int ret = 0; |
| 320 | |
| 321 | /* |
| 322 | * 0 will never be our subject keyid from a SHA-1 hash, but it could be |
| 323 | * our subject keyid if forced from child's akid. If so, set our |
| 324 | * authority keyid to 1. This way we are never self-signed, and thus |
| 325 | * exempt from any potential (off by default for now in OpenSSL) |
| 326 | * self-signature checks! |
| 327 | */ |
| 328 | id = (ASN1_STRING *) ((akid && akid->keyid) ? akid->keyid : 0); |
| 329 | if(id && M_ASN1_STRING_length(id) == 1 && *M_ASN1_STRING_data(id) == c) |
| 330 | c = 1; |
| 331 | |
| 332 | if( (akid = AUTHORITY_KEYID_new()) != 0 |
| 333 | && (akid->keyid = ASN1_OCTET_STRING_new()) != 0 |
| 334 | && M_ASN1_OCTET_STRING_set(akid->keyid, (void *) &c, 1) |
| 335 | && X509_add1_ext_i2d(cert, nid, akid, 0, X509V3_ADD_APPEND)) |
| 336 | ret = 1; |
| 337 | if(akid) |
| 338 | AUTHORITY_KEYID_free(akid); |
| 339 | return ret; |
| 340 | } |
| 341 | |
| 342 | static int |
| 343 | add_skid(X509 *cert, AUTHORITY_KEYID *akid) |
| 344 | { |
| 345 | int nid = NID_subject_key_identifier; |
| 346 | |
| 347 | if(!akid || !akid->keyid) |
| 348 | return add_ext(0, cert, nid, "hash"); |
| 349 | return X509_add1_ext_i2d(cert, nid, akid->keyid, 0, X509V3_ADD_APPEND) > 0; |
| 350 | } |
| 351 | |
| 352 | static X509_NAME * |
| 353 | akid_issuer_name(AUTHORITY_KEYID *akid) |
| 354 | { |
| 355 | if(akid && akid->issuer) |
| 356 | { |
| 357 | int i; |
| 358 | GENERAL_NAMES *gens = akid->issuer; |
| 359 | |
| 360 | for(i = 0; i < sk_GENERAL_NAME_num(gens); ++i) |
| 361 | { |
| 362 | GENERAL_NAME *gn = sk_GENERAL_NAME_value(gens, i); |
| 363 | |
| 364 | if(gn->type == GEN_DIRNAME) |
| 365 | return (gn->d.dirn); |
| 366 | } |
| 367 | } |
| 368 | return 0; |
| 369 | } |
| 370 | |
| 371 | static int |
| 372 | set_issuer_name(X509 *cert, AUTHORITY_KEYID *akid) |
| 373 | { |
| 374 | X509_NAME *name = akid_issuer_name(akid); |
| 375 | |
| 376 | /* |
| 377 | * If subject's akid specifies an authority key identifer issuer name, we |
| 378 | * must use that. |
| 379 | */ |
| 380 | return X509_set_issuer_name(cert, |
| 381 | name ? name : X509_get_subject_name(cert)); |
| 382 | } |
| 383 | |
| 384 | static int |
| 385 | grow_chain(ssl_dane *dane, int trusted, X509 *cert) |
| 386 | { |
| 387 | STACK_OF(X509) **xs = trusted ? &dane->roots : &dane->chain; |
| 388 | static ASN1_OBJECT *serverAuth = 0; |
| 389 | |
| 390 | #define UNTRUSTED 0 |
| 391 | #define TRUSTED 1 |
| 392 | |
| 393 | if( trusted && !serverAuth |
| 394 | && !(serverAuth = OBJ_nid2obj(NID_server_auth))) |
| 395 | { |
| 396 | DANEerr(DANE_F_GROW_CHAIN, ERR_R_MALLOC_FAILURE); |
| 397 | return 0; |
| 398 | } |
| 399 | if(!*xs && !(*xs = sk_X509_new_null())) |
| 400 | { |
| 401 | DANEerr(DANE_F_GROW_CHAIN, ERR_R_MALLOC_FAILURE); |
| 402 | return 0; |
| 403 | } |
| 404 | |
| 405 | if(cert) |
| 406 | { |
| 407 | if(trusted && !X509_add1_trust_object(cert, serverAuth)) |
| 408 | return 0; |
| 409 | CRYPTO_add(&cert->references, 1, CRYPTO_LOCK_X509); |
| 410 | if (!sk_X509_push(*xs, cert)) |
| 411 | { |
| 412 | X509_free(cert); |
| 413 | DANEerr(DANE_F_GROW_CHAIN, ERR_R_MALLOC_FAILURE); |
| 414 | return 0; |
| 415 | } |
| 416 | } |
| 417 | return 1; |
| 418 | } |
| 419 | |
| 420 | static int |
| 421 | wrap_issuer(ssl_dane *dane, EVP_PKEY *key, X509 *subject, int depth, int top) |
| 422 | { |
| 423 | int ret = 1; |
| 424 | X509 *cert = 0; |
| 425 | AUTHORITY_KEYID *akid; |
| 426 | X509_NAME *name = X509_get_issuer_name(subject); |
| 427 | EVP_PKEY *newkey = key ? key : X509_get_pubkey(subject); |
| 428 | |
| 429 | #define WRAP_MID 0 /* Ensure intermediate. */ |
| 430 | #define WRAP_TOP 1 /* Ensure self-signed. */ |
| 431 | |
| 432 | if(!name || !newkey || !(cert = X509_new())) |
| 433 | return 0; |
| 434 | |
| 435 | /* |
| 436 | * Record the depth of the trust-anchor certificate. |
| 437 | */ |
| 438 | if(dane->depth < 0) |
| 439 | dane->depth = depth + 1; |
| 440 | |
| 441 | /* |
| 442 | * XXX: Uncaught error condition: |
| 443 | * |
| 444 | * The return value is NULL both when the extension is missing, and when |
| 445 | * OpenSSL rans out of memory while parsing the extension. |
| 446 | */ |
| 447 | ERR_clear_error(); |
| 448 | akid = X509_get_ext_d2i(subject, NID_authority_key_identifier, 0, 0); |
| 449 | /* XXX: Should we peek at the error stack here??? */ |
| 450 | |
| 451 | /* |
| 452 | * If top is true generate a self-issued root CA, otherwise an |
| 453 | * intermediate CA and possibly its self-signed issuer. |
| 454 | * |
| 455 | * CA cert valid for +/- 30 days |
| 456 | */ |
| 457 | if( !X509_set_version(cert, 2) |
| 458 | || !set_serial(cert, akid, subject) |
| 459 | || !X509_set_subject_name(cert, name) |
| 460 | || !set_issuer_name(cert, akid) |
| 461 | || !X509_gmtime_adj(X509_get_notBefore(cert), -30 * 86400L) |
| 462 | || !X509_gmtime_adj(X509_get_notAfter(cert), 30 * 86400L) |
| 463 | || !X509_set_pubkey(cert, newkey) |
| 464 | || !add_ext(0, cert, NID_basic_constraints, "CA:TRUE") |
| 465 | || (!top && !add_akid(cert, akid)) |
| 466 | || !add_skid(cert, akid) |
| 467 | || ( !top && wrap_to_root |
| 468 | && !wrap_issuer(dane, newkey, cert, depth, WRAP_TOP))) |
| 469 | ret = 0; |
| 470 | |
| 471 | if(akid) |
| 472 | AUTHORITY_KEYID_free(akid); |
| 473 | if(!key) |
| 474 | EVP_PKEY_free(newkey); |
| 475 | if(ret) |
| 476 | ret = grow_chain(dane, !top && wrap_to_root ? UNTRUSTED : TRUSTED, cert); |
| 477 | if(cert) |
| 478 | X509_free(cert); |
| 479 | return ret; |
| 480 | } |
| 481 | |
| 482 | static int |
| 483 | wrap_cert(ssl_dane *dane, X509 *tacert, int depth) |
| 484 | { |
| 485 | if(dane->depth < 0) |
| 486 | dane->depth = depth + 1; |
| 487 | |
| 488 | /* |
| 489 | * If the TA certificate is self-issued, or need not be, use it directly. |
| 490 | * Otherwise, synthesize requisuite ancestors. |
| 491 | */ |
| 492 | if( !wrap_to_root |
| 493 | || X509_check_issued(tacert, tacert) == X509_V_OK) |
| 494 | return grow_chain(dane, TRUSTED, tacert); |
| 495 | |
| 496 | if(wrap_issuer(dane, 0, tacert, depth, WRAP_MID)) |
| 497 | return grow_chain(dane, UNTRUSTED, tacert); |
| 498 | return 0; |
| 499 | } |
| 500 | |
| 501 | static int |
| 502 | ta_signed(ssl_dane *dane, X509 *cert, int depth) |
| 503 | { |
| 504 | dane_cert_list x; |
| 505 | dane_pkey_list k; |
| 506 | EVP_PKEY *pk; |
| 507 | int done = 0; |
| 508 | |
| 509 | /* |
| 510 | * First check whether issued and signed by a TA cert, this is cheaper |
| 511 | * than the bare-public key checks below, since we can determine whether |
| 512 | * the candidate TA certificate issued the certificate to be checked |
| 513 | * first (name comparisons), before we bother with signature checks |
| 514 | * (public key operations). |
| 515 | */ |
| 516 | for (x = dane->certs; !done && x; x = x->next) |
| 517 | { |
| 518 | if(X509_check_issued(x->value, cert) == X509_V_OK) |
| 519 | { |
| 520 | if(!(pk = X509_get_pubkey(x->value))) |
| 521 | { |
| 522 | /* |
| 523 | * The cert originally contained a valid pkey, which does |
| 524 | * not just vanish, so this is most likely a memory error. |
| 525 | */ |
| 526 | done = -1; |
| 527 | break; |
| 528 | } |
| 529 | /* Check signature, since some other TA may work if not this. */ |
| 530 | if(X509_verify(cert, pk) > 0) |
| 531 | done = wrap_cert(dane, x->value, depth) ? 1 : -1; |
| 532 | EVP_PKEY_free(pk); |
| 533 | } |
| 534 | } |
| 535 | |
| 536 | /* |
| 537 | * With bare TA public keys, we can't check whether the trust chain is |
| 538 | * issued by the key, but we can determine whether it is signed by the |
| 539 | * key, so we go with that. |
| 540 | * |
| 541 | * Ideally, the corresponding certificate was presented in the chain, and we |
| 542 | * matched it by its public key digest one level up. This code is here |
| 543 | * to handle adverse conditions imposed by sloppy administrators of |
| 544 | * receiving systems with poorly constructed chains. |
| 545 | * |
| 546 | * We'd like to optimize out keys that should not match when the cert's |
| 547 | * authority key id does not match the key id of this key computed via |
| 548 | * the RFC keyid algorithm (SHA-1 digest of public key bit-string sans |
| 549 | * ASN1 tag and length thus also excluding the unused bits field that is |
| 550 | * logically part of the length). However, some CAs have a non-standard |
| 551 | * authority keyid, so we lose. Too bad. |
| 552 | * |
| 553 | * This may push errors onto the stack when the certificate signature is |
| 554 | * not of the right type or length, throw these away, |
| 555 | */ |
| 556 | for(k = dane->pkeys; !done && k; k = k->next) |
| 557 | if(X509_verify(cert, k->value) > 0) |
| 558 | done = wrap_issuer(dane, k->value, cert, depth, WRAP_MID) ? 1 : -1; |
| 559 | else |
| 560 | ERR_clear_error(); |
| 561 | |
| 562 | return done; |
| 563 | } |
| 564 | |
| 565 | static int |
| 566 | set_trust_anchor(X509_STORE_CTX *ctx, ssl_dane *dane, X509 *cert) |
| 567 | { |
| 568 | int matched = 0; |
| 569 | int n; |
| 570 | int i; |
| 571 | int depth = 0; |
| 572 | EVP_PKEY *takey; |
| 573 | X509 *ca; |
| 574 | STACK_OF(X509) *in = ctx->untrusted; /* XXX: Accessor? */ |
| 575 | |
| 576 | if(!grow_chain(dane, UNTRUSTED, 0)) |
| 577 | return -1; |
| 578 | |
| 579 | /* |
| 580 | * Accept a degenerate case: depth 0 self-signed trust-anchor. |
| 581 | */ |
| 582 | if(X509_check_issued(cert, cert) == X509_V_OK) |
| 583 | { |
| 584 | dane->depth = 0; |
| 585 | matched = match(dane->selectors[SSL_DANE_USAGE_TRUSTED_CA], cert, 0); |
| 586 | if(matched > 0 && !grow_chain(dane, TRUSTED, cert)) |
| 587 | matched = -1; |
| 588 | return matched; |
| 589 | } |
| 590 | |
| 591 | /* Make a shallow copy of the input untrusted chain. */ |
| 592 | if(!(in = sk_X509_dup(in))) |
| 593 | { |
| 594 | DANEerr(DANE_F_SET_TRUST_ANCHOR, ERR_R_MALLOC_FAILURE); |
| 595 | return -1; |
| 596 | } |
| 597 | |
| 598 | /* |
| 599 | * At each iteration we consume the issuer of the current cert. This |
| 600 | * reduces the length of the "in" chain by one. If no issuer is found, |
| 601 | * we are done. We also stop when a certificate matches a TA in the |
| 602 | * peer's TLSA RRset. |
| 603 | * |
| 604 | * Caller ensures that the initial certificate is not self-signed. |
| 605 | */ |
| 606 | for(n = sk_X509_num(in); n > 0; --n, ++depth) |
| 607 | { |
| 608 | for(i = 0; i < n; ++i) |
| 609 | if(X509_check_issued(sk_X509_value(in, i), cert) == X509_V_OK) |
| 610 | break; |
| 611 | |
| 612 | /* |
| 613 | * Final untrusted element with no issuer in the peer's chain, it may |
| 614 | * however be signed by a pkey or cert obtained via a TLSA RR. |
| 615 | */ |
| 616 | if(i == n) |
| 617 | break; |
| 618 | |
| 619 | /* Peer's chain contains an issuer ca. */ |
| 620 | ca = sk_X509_delete(in, i); |
| 621 | |
| 622 | /* If not a trust anchor, record untrusted ca and continue. */ |
| 623 | if((matched = match(dane->selectors[SSL_DANE_USAGE_TRUSTED_CA], ca, depth+1)) |
| 624 | == 0) |
| 625 | { |
| 626 | if(grow_chain(dane, UNTRUSTED, ca)) |
| 627 | { |
| 628 | if(!X509_check_issued(ca, ca) == X509_V_OK) |
| 629 | { |
| 630 | /* Restart with issuer as subject */ |
| 631 | cert = ca; |
| 632 | continue; |
| 633 | } |
| 634 | /* Final self-signed element, skip ta_signed() check. */ |
| 635 | cert = 0; |
| 636 | } |
| 637 | else |
| 638 | matched = -1; |
| 639 | } |
| 640 | else if(matched == MATCHED_CERT) |
| 641 | { |
| 642 | if(!wrap_cert(dane, ca, depth)) |
| 643 | matched = -1; |
| 644 | } |
| 645 | else if(matched == MATCHED_PKEY) |
| 646 | { |
| 647 | if( !(takey = X509_get_pubkey(ca)) |
| 648 | || !wrap_issuer(dane, takey, cert, depth, WRAP_MID)) |
| 649 | { |
| 650 | if(takey) |
| 651 | EVP_PKEY_free(takey); |
| 652 | else |
| 653 | DANEerr(DANE_F_SET_TRUST_ANCHOR, ERR_R_MALLOC_FAILURE); |
| 654 | matched = -1; |
| 655 | } |
| 656 | } |
| 657 | break; |
| 658 | } |
| 659 | |
| 660 | /* Shallow free the duplicated input untrusted chain. */ |
| 661 | sk_X509_free(in); |
| 662 | |
| 663 | /* |
| 664 | * When the loop exits, if "cert" is set, it is not self-signed and has |
| 665 | * no issuer in the chain, we check for a possible signature via a DNS |
| 666 | * obtained TA cert or public key. |
| 667 | */ |
| 668 | if(matched == 0 && cert) |
| 669 | matched = ta_signed(dane, cert, depth); |
| 670 | |
| 671 | return matched; |
| 672 | } |
| 673 | |
| 674 | static int |
| 675 | check_end_entity(X509_STORE_CTX *ctx, ssl_dane *dane, X509 *cert) |
| 676 | { |
| 677 | int matched; |
| 678 | |
| 679 | matched = match(dane->selectors[SSL_DANE_USAGE_FIXED_LEAF], cert, 0); |
| 680 | if(matched > 0) |
| 681 | if(!ctx->chain) |
| 682 | { |
| 683 | if( (ctx->chain = sk_X509_new_null()) |
| 684 | && sk_X509_push(ctx->chain, cert)) |
| 685 | CRYPTO_add(&cert->references, 1, CRYPTO_LOCK_X509); |
| 686 | else |
| 687 | { |
| 688 | DANEerr(DANE_F_CHECK_END_ENTITY, ERR_R_MALLOC_FAILURE); |
| 689 | return -1; |
| 690 | } |
| 691 | } |
| 692 | return matched; |
| 693 | } |
| 694 | |
| 695 | static int |
| 696 | match_name(const char *certid, ssl_dane *dane) |
| 697 | { |
| 698 | int multi = dane->multi; |
| 699 | dane_host_list hosts; |
| 700 | |
| 701 | for(hosts = dane->hosts; hosts; hosts = hosts->next) |
| 702 | { |
| 703 | int match_subdomain = 0; |
| 704 | const char *domain = hosts->value; |
| 705 | const char *parent; |
| 706 | int idlen; |
| 707 | int domlen; |
| 708 | |
| 709 | if(*domain == '.' && domain[1] != '\0') |
| 710 | { |
| 711 | ++domain; |
| 712 | match_subdomain = 1; |
| 713 | } |
| 714 | |
| 715 | /* |
| 716 | * Sub-domain match: certid is any sub-domain of hostname. |
| 717 | */ |
| 718 | if(match_subdomain) |
| 719 | { |
| 720 | if( (idlen = strlen(certid)) > (domlen = strlen(domain)) + 1 |
| 721 | && certid[idlen - domlen - 1] == '.' |
| 722 | && !strcasecmp(certid + (idlen - domlen), domain)) |
| 723 | return 1; |
| 724 | else |
| 725 | continue; |
| 726 | } |
| 727 | |
| 728 | /* |
| 729 | * Exact match and initial "*" match. The initial "*" in a certid |
| 730 | * matches one (if multi is false) or more hostname components under |
| 731 | * the condition that the certid contains multiple hostname components. |
| 732 | */ |
| 733 | if( !strcasecmp(certid, domain) |
| 734 | || ( certid[0] == '*' && certid[1] == '.' && certid[2] != 0 |
| 735 | && (parent = strchr(domain, '.')) != 0 |
| 736 | && (idlen = strlen(certid + 1)) <= (domlen = strlen(parent)) |
| 737 | && strcasecmp(multi ? parent + domlen - idlen : parent, certid+1) == 0)) |
| 738 | return 1; |
| 739 | } |
| 740 | return 0; |
| 741 | } |
| 742 | |
| 743 | static char * |
| 744 | check_name(char *name, int len) |
| 745 | { |
| 746 | char *cp = name + len; |
| 747 | |
| 748 | while(len > 0 && !*--cp) |
| 749 | --len; /* Ignore trailing NULs */ |
| 750 | if(len <= 0) |
| 751 | return 0; |
| 752 | for(cp = name; *cp; cp++) |
| 753 | { |
| 754 | char c = *cp; |
| 755 | if (!((c >= 'a' && c <= 'z') || |
| 756 | (c >= '0' && c <= '9') || |
| 757 | (c >= 'A' && c <= 'Z') || |
| 758 | (c == '.' || c == '-') || |
| 759 | (c == '*'))) |
| 760 | return 0; /* Only LDH, '.' and '*' */ |
| 761 | } |
| 762 | if(cp - name != len) /* Guard against internal NULs */ |
| 763 | return 0; |
| 764 | return name; |
| 765 | } |
| 766 | |
| 767 | static char * |
| 768 | parse_dns_name(const GENERAL_NAME *gn) |
| 769 | { |
| 770 | if(gn->type != GEN_DNS) |
| 771 | return 0; |
| 772 | if(ASN1_STRING_type(gn->d.ia5) != V_ASN1_IA5STRING) |
| 773 | return 0; |
| 774 | return check_name((char *) ASN1_STRING_data(gn->d.ia5), |
| 775 | ASN1_STRING_length(gn->d.ia5)); |
| 776 | } |
| 777 | |
| 778 | static char * |
| 779 | parse_subject_name(X509 *cert) |
| 780 | { |
| 781 | X509_NAME *name = X509_get_subject_name(cert); |
| 782 | X509_NAME_ENTRY *entry; |
| 783 | ASN1_STRING *entry_str; |
| 784 | unsigned char *namebuf; |
| 785 | int nid = NID_commonName; |
| 786 | int len; |
| 787 | int i; |
| 788 | |
| 789 | if(!name || (i = X509_NAME_get_index_by_NID(name, nid, -1)) < 0) |
| 790 | return 0; |
| 791 | if(!(entry = X509_NAME_get_entry(name, i))) |
| 792 | return 0; |
| 793 | if(!(entry_str = X509_NAME_ENTRY_get_data(entry))) |
| 794 | return 0; |
| 795 | |
| 796 | if((len = ASN1_STRING_to_UTF8(&namebuf, entry_str)) < 0) |
| 797 | return 0; |
| 798 | if(len <= 0 || check_name((char *) namebuf, len) == 0) |
| 799 | { |
| 800 | OPENSSL_free(namebuf); |
| 801 | return 0; |
| 802 | } |
| 803 | return (char *) namebuf; |
| 804 | } |
| 805 | |
| 806 | static int |
| 807 | name_check(ssl_dane *dane, X509 *cert) |
| 808 | { |
| 809 | int matched = 0; |
| 810 | BOOL got_altname = FALSE; |
| 811 | GENERAL_NAMES *gens; |
| 812 | |
| 813 | gens = X509_get_ext_d2i(cert, NID_subject_alt_name, 0, 0); |
| 814 | if(gens) |
| 815 | { |
| 816 | int n = sk_GENERAL_NAME_num(gens); |
| 817 | int i; |
| 818 | |
| 819 | for(i = 0; i < n; ++i) |
| 820 | { |
| 821 | const GENERAL_NAME *gn = sk_GENERAL_NAME_value(gens, i); |
| 822 | const char *certid; |
| 823 | |
| 824 | if(gn->type != GEN_DNS) |
| 825 | continue; |
| 826 | got_altname = TRUE; |
| 827 | certid = parse_dns_name(gn); |
| 828 | if(certid && *certid) |
| 829 | { |
| 830 | if((matched = match_name(certid, dane)) == 0) |
| 831 | continue; |
| 832 | if(!(dane->mhost = OPENSSL_strdup(certid))) |
| 833 | matched = -1; |
| 834 | break; |
| 835 | } |
| 836 | } |
| 837 | GENERAL_NAMES_free(gens); |
| 838 | } |
| 839 | |
| 840 | /* |
| 841 | * XXX: Should the subjectName be skipped when *any* altnames are present, |
| 842 | * or only when DNS altnames are present? |
| 843 | */ |
| 844 | if(got_altname) |
| 845 | { |
| 846 | char *certid = parse_subject_name(cert); |
| 847 | if(certid != 0 && *certid && (matched = match_name(certid, dane)) != 0) |
| 848 | dane->mhost = certid; /* Already a copy */ |
| 849 | } |
| 850 | return matched; |
| 851 | } |
| 852 | |
| 853 | static int |
| 854 | verify_chain(X509_STORE_CTX *ctx) |
| 855 | { |
| 856 | dane_selector_list issuer_rrs; |
| 857 | dane_selector_list leaf_rrs; |
| 858 | int (*cb)(int, X509_STORE_CTX *) = ctx->verify_cb; |
| 859 | int ssl_idx = SSL_get_ex_data_X509_STORE_CTX_idx(); |
| 860 | SSL *ssl = X509_STORE_CTX_get_ex_data(ctx, ssl_idx); |
| 861 | ssl_dane *dane = SSL_get_ex_data(ssl, dane_idx); |
| 862 | X509 *cert = ctx->cert; /* XXX: accessor? */ |
| 863 | int matched = 0; |
| 864 | int chain_length = sk_X509_num(ctx->chain); |
| 865 | |
| 866 | DEBUG(D_tls) debug_printf("Dane verify-chain\n"); |
| 867 | |
| 868 | issuer_rrs = dane->selectors[SSL_DANE_USAGE_LIMIT_ISSUER]; |
| 869 | leaf_rrs = dane->selectors[SSL_DANE_USAGE_LIMIT_LEAF]; |
| 870 | ctx->verify = dane->verify; |
| 871 | |
| 872 | if((matched = name_check(dane, cert)) < 0) |
| 873 | { |
| 874 | X509_STORE_CTX_set_error(ctx, X509_V_ERR_OUT_OF_MEM); |
| 875 | return 0; |
| 876 | } |
| 877 | |
| 878 | if(!matched) |
| 879 | { |
| 880 | ctx->error_depth = 0; |
| 881 | ctx->current_cert = cert; |
| 882 | X509_STORE_CTX_set_error(ctx, X509_V_ERR_HOSTNAME_MISMATCH); |
| 883 | if(!cb(0, ctx)) |
| 884 | return 0; |
| 885 | } |
| 886 | matched = 0; |
| 887 | |
| 888 | /* |
| 889 | * Satisfy at least one usage 0 or 1 constraint, unless we've already |
| 890 | * matched a usage 2 trust anchor. |
| 891 | * |
| 892 | * XXX: internal_verify() doesn't callback with top certs that are not |
| 893 | * self-issued. This should be fixed in a future OpenSSL. |
| 894 | */ |
| 895 | if(dane->roots && sk_X509_num(dane->roots)) |
| 896 | { |
| 897 | #ifndef NO_CALLBACK_WORKAROUND |
| 898 | X509 *top = sk_X509_value(ctx->chain, dane->depth); |
| 899 | |
| 900 | if(X509_check_issued(top, top) != X509_V_OK) |
| 901 | { |
| 902 | ctx->error_depth = dane->depth; |
| 903 | ctx->current_cert = top; |
| 904 | if(!cb(1, ctx)) |
| 905 | return 0; |
| 906 | } |
| 907 | #endif |
| 908 | /* Pop synthetic trust-anchor ancestors off the chain! */ |
| 909 | while (--chain_length > dane->depth) |
| 910 | X509_free(sk_X509_pop(ctx->chain)); |
| 911 | } |
| 912 | else if(issuer_rrs || leaf_rrs) |
| 913 | { |
| 914 | int n = chain_length; |
| 915 | |
| 916 | /* |
| 917 | * Check for an EE match, then a CA match at depths > 0, and |
| 918 | * finally, if the EE cert is self-issued, for a depth 0 CA match. |
| 919 | */ |
| 920 | if(leaf_rrs) |
| 921 | matched = match(leaf_rrs, cert, 0); |
| 922 | while(!matched && issuer_rrs && --n >= 0) |
| 923 | { |
| 924 | X509 *xn = sk_X509_value(ctx->chain, n); |
| 925 | |
| 926 | if(n > 0 || X509_check_issued(xn, xn) == X509_V_OK) |
| 927 | matched = match(issuer_rrs, xn, n); |
| 928 | } |
| 929 | |
| 930 | if(matched < 0) |
| 931 | { |
| 932 | X509_STORE_CTX_set_error(ctx, X509_V_ERR_OUT_OF_MEM); |
| 933 | return 0; |
| 934 | } |
| 935 | |
| 936 | if(!matched) |
| 937 | { |
| 938 | ctx->current_cert = cert; |
| 939 | ctx->error_depth = 0; |
| 940 | X509_STORE_CTX_set_error(ctx, X509_V_ERR_CERT_UNTRUSTED); |
| 941 | if(!cb(0, ctx)) |
| 942 | return 0; |
| 943 | } |
| 944 | } |
| 945 | |
| 946 | return ctx->verify(ctx); |
| 947 | } |
| 948 | |
| 949 | static int |
| 950 | verify_cert(X509_STORE_CTX *ctx, void *unused_ctx) |
| 951 | { |
| 952 | static int ssl_idx = -1; |
| 953 | SSL *ssl; |
| 954 | ssl_dane *dane; |
| 955 | int (*cb)(int, X509_STORE_CTX *) = ctx->verify_cb; |
| 956 | int matched; |
| 957 | X509 *cert = ctx->cert; /* XXX: accessor? */ |
| 958 | |
| 959 | DEBUG(D_tls) debug_printf("Dane verify-cert\n"); |
| 960 | |
| 961 | if(ssl_idx < 0) |
| 962 | ssl_idx = SSL_get_ex_data_X509_STORE_CTX_idx(); |
| 963 | if(dane_idx < 0) |
| 964 | { |
| 965 | DANEerr(DANE_F_VERIFY_CERT, ERR_R_MALLOC_FAILURE); |
| 966 | return -1; |
| 967 | } |
| 968 | |
| 969 | ssl = X509_STORE_CTX_get_ex_data(ctx, ssl_idx); |
| 970 | if(!(dane = SSL_get_ex_data(ssl, dane_idx)) || !cert) |
| 971 | return X509_verify_cert(ctx); |
| 972 | |
| 973 | if(dane->selectors[SSL_DANE_USAGE_FIXED_LEAF]) |
| 974 | { |
| 975 | if((matched = check_end_entity(ctx, dane, cert)) > 0) |
| 976 | { |
| 977 | ctx->error_depth = 0; |
| 978 | ctx->current_cert = cert; |
| 979 | return cb(1, ctx); |
| 980 | } |
| 981 | if(matched < 0) |
| 982 | { |
| 983 | X509_STORE_CTX_set_error(ctx, X509_V_ERR_OUT_OF_MEM); |
| 984 | return -1; |
| 985 | } |
| 986 | } |
| 987 | |
| 988 | if(dane->selectors[SSL_DANE_USAGE_TRUSTED_CA]) |
| 989 | { |
| 990 | if((matched = set_trust_anchor(ctx, dane, cert)) < 0) |
| 991 | { |
| 992 | X509_STORE_CTX_set_error(ctx, X509_V_ERR_OUT_OF_MEM); |
| 993 | return -1; |
| 994 | } |
| 995 | if(matched) |
| 996 | { |
| 997 | /* |
| 998 | * Check that setting the untrusted chain updates the expected |
| 999 | * structure member at the expected offset. |
| 1000 | */ |
| 1001 | X509_STORE_CTX_trusted_stack(ctx, dane->roots); |
| 1002 | X509_STORE_CTX_set_chain(ctx, dane->chain); |
| 1003 | OPENSSL_assert(ctx->untrusted == dane->chain); |
| 1004 | } |
| 1005 | } |
| 1006 | |
| 1007 | /* |
| 1008 | * Name checks and usage 0/1 constraint enforcement are delayed until |
| 1009 | * X509_verify_cert() builds the full chain and calls our verify_chain() |
| 1010 | * wrapper. |
| 1011 | */ |
| 1012 | dane->verify = ctx->verify; |
| 1013 | ctx->verify = verify_chain; |
| 1014 | |
| 1015 | return X509_verify_cert(ctx); |
| 1016 | } |
| 1017 | |
| 1018 | static dane_list |
| 1019 | list_alloc(size_t vsize) |
| 1020 | { |
| 1021 | void *value = (void *) OPENSSL_malloc(vsize); |
| 1022 | dane_list l; |
| 1023 | |
| 1024 | if(!value) |
| 1025 | { |
| 1026 | DANEerr(DANE_F_LIST_ALLOC, ERR_R_MALLOC_FAILURE); |
| 1027 | return 0; |
| 1028 | } |
| 1029 | if(!(l = (dane_list) OPENSSL_malloc(sizeof(*l)))) |
| 1030 | { |
| 1031 | OPENSSL_free(value); |
| 1032 | DANEerr(DANE_F_LIST_ALLOC, ERR_R_MALLOC_FAILURE); |
| 1033 | return 0; |
| 1034 | } |
| 1035 | l->next = 0; |
| 1036 | l->value = value; |
| 1037 | return l; |
| 1038 | } |
| 1039 | |
| 1040 | static void |
| 1041 | list_free(void *list, void (*f)(void *)) |
| 1042 | { |
| 1043 | dane_list head; |
| 1044 | dane_list next; |
| 1045 | |
| 1046 | for(head = (dane_list) list; head; head = next) |
| 1047 | { |
| 1048 | next = head->next; |
| 1049 | if (f && head->value) |
| 1050 | f(head->value); |
| 1051 | OPENSSL_free(head); |
| 1052 | } |
| 1053 | } |
| 1054 | |
| 1055 | static void |
| 1056 | dane_mtype_free(void *p) |
| 1057 | { |
| 1058 | list_free(((dane_mtype) p)->data, OPENSSL_freeFunc); |
| 1059 | OPENSSL_free(p); |
| 1060 | } |
| 1061 | |
| 1062 | static void |
| 1063 | dane_selector_free(void *p) |
| 1064 | { |
| 1065 | list_free(((dane_selector) p)->mtype, dane_mtype_free); |
| 1066 | OPENSSL_free(p); |
| 1067 | } |
| 1068 | |
| 1069 | |
| 1070 | |
| 1071 | /* |
| 1072 | |
| 1073 | Tidy up once the connection is finished with. |
| 1074 | |
| 1075 | Arguments |
| 1076 | ssl The ssl connection handle |
| 1077 | |
| 1078 | => Before calling SSL_free() |
| 1079 | tls_close() and tls_getc() [the error path] are the obvious places. |
| 1080 | Could we do it earlier - right after verification? In tls_client_start() |
| 1081 | right after SSL_connect() returns, in that case. |
| 1082 | |
| 1083 | */ |
| 1084 | |
| 1085 | void |
| 1086 | DANESSL_cleanup(SSL *ssl) |
| 1087 | { |
| 1088 | ssl_dane *dane; |
| 1089 | int u; |
| 1090 | |
| 1091 | DEBUG(D_tls) debug_printf("Dane lib-cleanup\n"); |
| 1092 | |
| 1093 | if(dane_idx < 0 || !(dane = SSL_get_ex_data(ssl, dane_idx))) |
| 1094 | return; |
| 1095 | (void) SSL_set_ex_data(ssl, dane_idx, 0); |
| 1096 | |
| 1097 | if(dane->hosts) |
| 1098 | list_free(dane->hosts, OPENSSL_freeFunc); |
| 1099 | if(dane->mhost) |
| 1100 | OPENSSL_free(dane->mhost); |
| 1101 | for(u = 0; u <= SSL_DANE_USAGE_LAST; ++u) |
| 1102 | if(dane->selectors[u]) |
| 1103 | list_free(dane->selectors[u], dane_selector_free); |
| 1104 | if(dane->pkeys) |
| 1105 | list_free(dane->pkeys, pkey_free); |
| 1106 | if(dane->certs) |
| 1107 | list_free(dane->certs, cert_free); |
| 1108 | if(dane->roots) |
| 1109 | sk_X509_pop_free(dane->roots, X509_free); |
| 1110 | if(dane->chain) |
| 1111 | sk_X509_pop_free(dane->chain, X509_free); |
| 1112 | OPENSSL_free(dane); |
| 1113 | } |
| 1114 | |
| 1115 | static dane_host_list |
| 1116 | host_list_init(const char **src) |
| 1117 | { |
| 1118 | dane_host_list head = NULL; |
| 1119 | |
| 1120 | while(*src) |
| 1121 | { |
| 1122 | dane_host_list elem = (dane_host_list) OPENSSL_malloc(sizeof(*elem)); |
| 1123 | if(!elem) |
| 1124 | { |
| 1125 | list_free(head, OPENSSL_freeFunc); |
| 1126 | return 0; |
| 1127 | } |
| 1128 | elem->value = OPENSSL_strdup(*src++); |
| 1129 | LINSERT(head, elem); |
| 1130 | } |
| 1131 | return head; |
| 1132 | } |
| 1133 | |
| 1134 | |
| 1135 | |
| 1136 | |
| 1137 | /* |
| 1138 | |
| 1139 | Call this for each TLSA record found for the target, after the |
| 1140 | DANE setup has been done on the ssl connection handle. |
| 1141 | |
| 1142 | Arguments: |
| 1143 | ssl Connection handle |
| 1144 | usage TLSA record field |
| 1145 | selector TLSA record field |
| 1146 | mdname ??? message digest name? |
| 1147 | data ??? TLSA record megalump? |
| 1148 | dlen length of data |
| 1149 | |
| 1150 | Return |
| 1151 | -1 on error |
| 1152 | 0 action not taken |
| 1153 | 1 record accepted |
| 1154 | */ |
| 1155 | |
| 1156 | int |
| 1157 | DANESSL_add_tlsa(SSL *ssl, uint8_t usage, uint8_t selector, const char *mdname, |
| 1158 | unsigned const char *data, size_t dlen) |
| 1159 | { |
| 1160 | ssl_dane *dane; |
| 1161 | dane_selector_list s = 0; |
| 1162 | dane_mtype_list m = 0; |
| 1163 | dane_data_list d = 0; |
| 1164 | dane_cert_list xlist = 0; |
| 1165 | dane_pkey_list klist = 0; |
| 1166 | const EVP_MD *md = 0; |
| 1167 | |
| 1168 | DEBUG(D_tls) debug_printf("Dane add-tlsa: usage %u sel %u mdname \"%s\"\n", |
| 1169 | usage, selector, mdname); |
| 1170 | |
| 1171 | if(dane_idx < 0 || !(dane = SSL_get_ex_data(ssl, dane_idx))) |
| 1172 | { |
| 1173 | DANEerr(DANE_F_SSL_DANE_ADD_TLSA, DANE_R_DANE_INIT); |
| 1174 | return -1; |
| 1175 | } |
| 1176 | |
| 1177 | if(usage > SSL_DANE_USAGE_LAST) |
| 1178 | { |
| 1179 | DANEerr(DANE_F_SSL_DANE_ADD_TLSA, DANE_R_BAD_USAGE); |
| 1180 | return 0; |
| 1181 | } |
| 1182 | if(selector > SSL_DANE_SELECTOR_LAST) |
| 1183 | { |
| 1184 | DANEerr(DANE_F_SSL_DANE_ADD_TLSA, DANE_R_BAD_SELECTOR); |
| 1185 | return 0; |
| 1186 | } |
| 1187 | if(mdname && !(md = EVP_get_digestbyname(mdname))) |
| 1188 | { |
| 1189 | DANEerr(DANE_F_SSL_DANE_ADD_TLSA, DANE_R_BAD_DIGEST); |
| 1190 | return 0; |
| 1191 | } |
| 1192 | if(!data) |
| 1193 | { |
| 1194 | DANEerr(DANE_F_SSL_DANE_ADD_TLSA, DANE_R_BAD_NULL_DATA); |
| 1195 | return 0; |
| 1196 | } |
| 1197 | if(mdname && dlen != EVP_MD_size(md)) |
| 1198 | { |
| 1199 | DANEerr(DANE_F_SSL_DANE_ADD_TLSA, DANE_R_BAD_DATA_LENGTH); |
| 1200 | return 0; |
| 1201 | } |
| 1202 | |
| 1203 | if(!mdname) |
| 1204 | { |
| 1205 | X509 *x = 0; |
| 1206 | EVP_PKEY *k = 0; |
| 1207 | const unsigned char *p = data; |
| 1208 | |
| 1209 | #define xklistinit(lvar, ltype, var, freeFunc) do { \ |
| 1210 | (lvar) = (ltype) OPENSSL_malloc(sizeof(*(lvar))); \ |
| 1211 | if (!(lvar)) { \ |
| 1212 | DANEerr(DANE_F_SSL_DANE_ADD_TLSA, ERR_R_MALLOC_FAILURE); \ |
| 1213 | freeFunc((var)); \ |
| 1214 | return 0; \ |
| 1215 | } \ |
| 1216 | (lvar)->next = 0; \ |
| 1217 | lvar->value = var; \ |
| 1218 | } while (0) |
| 1219 | #define xkfreeret(ret) do { \ |
| 1220 | if (xlist) list_free(xlist, cert_free); \ |
| 1221 | if (klist) list_free(klist, pkey_free); \ |
| 1222 | return (ret); \ |
| 1223 | } while (0) |
| 1224 | |
| 1225 | switch(selector) |
| 1226 | { |
| 1227 | case SSL_DANE_SELECTOR_CERT: |
| 1228 | if(!d2i_X509(&x, &p, dlen) || dlen != p - data) |
| 1229 | { |
| 1230 | if (x) |
| 1231 | X509_free(x); |
| 1232 | DANEerr(DANE_F_SSL_DANE_ADD_TLSA, DANE_R_BAD_CERT); |
| 1233 | return 0; |
| 1234 | } |
| 1235 | k = X509_get_pubkey(x); |
| 1236 | EVP_PKEY_free(k); |
| 1237 | if(!k) |
| 1238 | { |
| 1239 | X509_free(x); |
| 1240 | DANEerr(DANE_F_SSL_DANE_ADD_TLSA, DANE_R_BAD_CERT_PKEY); |
| 1241 | return 0; |
| 1242 | } |
| 1243 | if(usage == SSL_DANE_USAGE_TRUSTED_CA) |
| 1244 | xklistinit(xlist, dane_cert_list, x, X509_free); |
| 1245 | break; |
| 1246 | |
| 1247 | case SSL_DANE_SELECTOR_SPKI: |
| 1248 | if(!d2i_PUBKEY(&k, &p, dlen) || dlen != p - data) |
| 1249 | { |
| 1250 | if(k) |
| 1251 | EVP_PKEY_free(k); |
| 1252 | DANEerr(DANE_F_SSL_DANE_ADD_TLSA, DANE_R_BAD_PKEY); |
| 1253 | return 0; |
| 1254 | } |
| 1255 | if(usage == SSL_DANE_USAGE_TRUSTED_CA) |
| 1256 | xklistinit(klist, dane_pkey_list, k, EVP_PKEY_free); |
| 1257 | break; |
| 1258 | } |
| 1259 | } |
| 1260 | |
| 1261 | /* Find insertion point and don't add duplicate elements. */ |
| 1262 | for(s = dane->selectors[usage]; s; s = s->next) |
| 1263 | if(s->value->selector == selector) |
| 1264 | for(m = s->value->mtype; m; m = m->next) |
| 1265 | if(m->value->md == md) |
| 1266 | for(d = m->value->data; d; d = d->next) |
| 1267 | if( d->value->datalen == dlen |
| 1268 | && memcmp(d->value->data, data, dlen) == 0) |
| 1269 | xkfreeret(1); |
| 1270 | |
| 1271 | if(!(d = (dane_data_list) list_alloc(sizeof(*d->value) + dlen))) |
| 1272 | xkfreeret(0); |
| 1273 | d->value->datalen = dlen; |
| 1274 | memcpy(d->value->data, data, dlen); |
| 1275 | if(!m) |
| 1276 | { |
| 1277 | if(!(m = (dane_mtype_list) list_alloc(sizeof(*m->value)))) |
| 1278 | { |
| 1279 | list_free(d, OPENSSL_freeFunc); |
| 1280 | xkfreeret(0); |
| 1281 | } |
| 1282 | m->value->data = 0; |
| 1283 | if((m->value->md = md) != 0) |
| 1284 | m->value->mdlen = dlen; |
| 1285 | if(!s) |
| 1286 | { |
| 1287 | if(!(s = (dane_selector_list) list_alloc(sizeof(*s->value)))) |
| 1288 | { |
| 1289 | list_free(m, dane_mtype_free); |
| 1290 | xkfreeret(0); |
| 1291 | } |
| 1292 | s->value->mtype = 0; |
| 1293 | s->value->selector = selector; |
| 1294 | LINSERT(dane->selectors[usage], s); |
| 1295 | } |
| 1296 | LINSERT(s->value->mtype, m); |
| 1297 | } |
| 1298 | LINSERT(m->value->data, d); |
| 1299 | |
| 1300 | if(xlist) |
| 1301 | LINSERT(dane->certs, xlist); |
| 1302 | else if(klist) |
| 1303 | LINSERT(dane->pkeys, klist); |
| 1304 | ++dane->count; |
| 1305 | return 1; |
| 1306 | } |
| 1307 | |
| 1308 | |
| 1309 | |
| 1310 | |
| 1311 | /* |
| 1312 | Call this once we have an ssl connection handle but before |
| 1313 | making the TLS connection. |
| 1314 | |
| 1315 | => In tls_client_start() after the call to SSL_new() |
| 1316 | and before the call to SSL_connect(). Exactly where |
| 1317 | probably does not matter. |
| 1318 | We probably want to keep our existing SNI handling; |
| 1319 | call this with NULL. |
| 1320 | |
| 1321 | Arguments: |
| 1322 | ssl Connection handle |
| 1323 | sni_domain Optional peer server name |
| 1324 | hostnames list of names to chack against peer cert |
| 1325 | |
| 1326 | Return |
| 1327 | -1 on fatal error |
| 1328 | 0 nonfatal error |
| 1329 | 1 success |
| 1330 | */ |
| 1331 | |
| 1332 | int |
| 1333 | DANESSL_init(SSL *ssl, const char *sni_domain, const char **hostnames) |
| 1334 | { |
| 1335 | ssl_dane *dane; |
| 1336 | int i; |
| 1337 | #ifdef OPENSSL_INTERNAL |
| 1338 | SSL_CTX *sctx = SSL_get_SSL_CTX(ssl); |
| 1339 | |
| 1340 | |
| 1341 | if(sctx->app_verify_callback != verify_cert) |
| 1342 | { |
| 1343 | DANEerr(DANE_F_SSL_DANE_INIT, DANE_R_SCTX_INIT); |
| 1344 | return -1; |
| 1345 | } |
| 1346 | #else |
| 1347 | DEBUG(D_tls) debug_printf("Dane ssl-init\n"); |
| 1348 | if(dane_idx < 0) |
| 1349 | { |
| 1350 | DANEerr(DANE_F_SSL_DANE_INIT, DANE_R_LIBRARY_INIT); |
| 1351 | return -1; |
| 1352 | } |
| 1353 | #endif |
| 1354 | |
| 1355 | if(sni_domain && !SSL_set_tlsext_host_name(ssl, sni_domain)) |
| 1356 | return 0; |
| 1357 | |
| 1358 | if(!(dane = (ssl_dane *) OPENSSL_malloc(sizeof(ssl_dane)))) |
| 1359 | { |
| 1360 | DANEerr(DANE_F_SSL_DANE_INIT, ERR_R_MALLOC_FAILURE); |
| 1361 | return 0; |
| 1362 | } |
| 1363 | if(!SSL_set_ex_data(ssl, dane_idx, dane)) |
| 1364 | { |
| 1365 | DANEerr(DANE_F_SSL_DANE_INIT, ERR_R_MALLOC_FAILURE); |
| 1366 | OPENSSL_free(dane); |
| 1367 | return 0; |
| 1368 | } |
| 1369 | |
| 1370 | dane->verify = 0; |
| 1371 | dane->hosts = 0; |
| 1372 | dane->thost = 0; |
| 1373 | dane->pkeys = 0; |
| 1374 | dane->certs = 0; |
| 1375 | dane->chain = 0; |
| 1376 | dane->roots = 0; |
| 1377 | dane->depth = -1; |
| 1378 | dane->mhost = 0; /* Future SSL control interface */ |
| 1379 | dane->multi = 0; /* Future SSL control interface */ |
| 1380 | dane->count = 0; |
| 1381 | |
| 1382 | for(i = 0; i <= SSL_DANE_USAGE_LAST; ++i) |
| 1383 | dane->selectors[i] = 0; |
| 1384 | |
| 1385 | if(hostnames && !(dane->hosts = host_list_init(hostnames))) |
| 1386 | { |
| 1387 | DANEerr(DANE_F_SSL_DANE_INIT, ERR_R_MALLOC_FAILURE); |
| 1388 | DANESSL_cleanup(ssl); |
| 1389 | return 0; |
| 1390 | } |
| 1391 | |
| 1392 | return 1; |
| 1393 | } |
| 1394 | |
| 1395 | |
| 1396 | /* |
| 1397 | |
| 1398 | Call this once we have a context to work with, but |
| 1399 | before DANESSL_init() |
| 1400 | |
| 1401 | => in tls_client_start(), after tls_init() call gives us the ctx, |
| 1402 | if we decide we want to (policy) and can (TLSA records available) |
| 1403 | replacing (? what about fallback) everything from testing tls_verify_hosts |
| 1404 | down to just before calling SSL_new() for the conn handle. |
| 1405 | |
| 1406 | Arguments |
| 1407 | ctx SSL context |
| 1408 | |
| 1409 | Return |
| 1410 | -1 Error |
| 1411 | 1 Success |
| 1412 | */ |
| 1413 | |
| 1414 | int |
| 1415 | DANESSL_CTX_init(SSL_CTX *ctx) |
| 1416 | { |
| 1417 | DEBUG(D_tls) debug_printf("Dane ctx-init\n"); |
| 1418 | if(dane_idx >= 0) |
| 1419 | { |
| 1420 | SSL_CTX_set_cert_verify_callback(ctx, verify_cert, 0); |
| 1421 | return 1; |
| 1422 | } |
| 1423 | DANEerr(DANE_F_SSL_CTX_DANE_INIT, DANE_R_LIBRARY_INIT); |
| 1424 | return -1; |
| 1425 | } |
| 1426 | |
| 1427 | static int |
| 1428 | init_once(volatile int *value, int (*init)(void), void (*postinit)(void)) |
| 1429 | { |
| 1430 | int wlock = 0; |
| 1431 | |
| 1432 | CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX); |
| 1433 | if(*value < 0) |
| 1434 | { |
| 1435 | CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX); |
| 1436 | CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX); |
| 1437 | wlock = 1; |
| 1438 | if(*value < 0) |
| 1439 | { |
| 1440 | *value = init(); |
| 1441 | if(postinit) |
| 1442 | postinit(); |
| 1443 | } |
| 1444 | } |
| 1445 | if (wlock) |
| 1446 | CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX); |
| 1447 | else |
| 1448 | CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX); |
| 1449 | return *value; |
| 1450 | } |
| 1451 | |
| 1452 | static void |
| 1453 | dane_init(void) |
| 1454 | { |
| 1455 | /* |
| 1456 | * Store library id in zeroth function slot, used to locate the library |
| 1457 | * name. This must be done before we load the error strings. |
| 1458 | */ |
| 1459 | #ifndef OPENSSL_NO_ERR |
| 1460 | dane_str_functs[0].error |= ERR_PACK(err_lib_dane, 0, 0); |
| 1461 | ERR_load_strings(err_lib_dane, dane_str_functs); |
| 1462 | ERR_load_strings(err_lib_dane, dane_str_reasons); |
| 1463 | #endif |
| 1464 | |
| 1465 | /* |
| 1466 | * Register SHA-2 digests, if implemented and not already registered. |
| 1467 | */ |
| 1468 | #if defined(LN_sha256) && defined(NID_sha256) && !defined(OPENSSL_NO_SHA256) |
| 1469 | if(!EVP_get_digestbyname(LN_sha224)) EVP_add_digest(EVP_sha224()); |
| 1470 | if(!EVP_get_digestbyname(LN_sha256)) EVP_add_digest(EVP_sha256()); |
| 1471 | #endif |
| 1472 | #if defined(LN_sha512) && defined(NID_sha512) && !defined(OPENSSL_NO_SHA512) |
| 1473 | if(!EVP_get_digestbyname(LN_sha384)) EVP_add_digest(EVP_sha384()); |
| 1474 | if(!EVP_get_digestbyname(LN_sha512)) EVP_add_digest(EVP_sha512()); |
| 1475 | #endif |
| 1476 | |
| 1477 | /* |
| 1478 | * Register an SSL index for the connection-specific ssl_dane structure. |
| 1479 | * Using a separate index makes it possible to add DANE support to |
| 1480 | * existing OpenSSL releases that don't have a suitable pointer in the |
| 1481 | * SSL structure. |
| 1482 | */ |
| 1483 | dane_idx = SSL_get_ex_new_index(0, 0, 0, 0, 0); |
| 1484 | } |
| 1485 | |
| 1486 | |
| 1487 | |
| 1488 | /* |
| 1489 | |
| 1490 | Call this once. Probably early in startup will do; may need |
| 1491 | to be after SSL library init. |
| 1492 | |
| 1493 | => put after call to tls_init() for now |
| 1494 | |
| 1495 | Return |
| 1496 | 1 Success |
| 1497 | 0 Fail |
| 1498 | */ |
| 1499 | |
| 1500 | int |
| 1501 | DANESSL_library_init(void) |
| 1502 | { |
| 1503 | DEBUG(D_tls) debug_printf("Dane lib-init\n"); |
| 1504 | if(err_lib_dane < 0) |
| 1505 | init_once(&err_lib_dane, ERR_get_next_error_library, dane_init); |
| 1506 | |
| 1507 | #if defined(LN_sha256) |
| 1508 | /* No DANE without SHA256 support */ |
| 1509 | if(dane_idx >= 0 && EVP_get_digestbyname(LN_sha256) != 0) |
| 1510 | return 1; |
| 1511 | #endif |
| 1512 | |
| 1513 | DANEerr(DANE_F_SSL_DANE_LIBRARY_INIT, DANE_R_DANE_SUPPORT); |
| 1514 | return 0; |
| 1515 | } |
| 1516 | |
| 1517 | |
| 1518 | #endif /* OPENSSL_VERSION_NUMBER */ |
| 1519 | /* vi: aw ai sw=2 |
| 1520 | */ |