1 /* 2 * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 #ifdef OPENSSL_NO_CT 11 # error "CT disabled" 12 #endif 13 14 #include <openssl/ct.h> 15 #include <openssl/err.h> 16 #include <openssl/evp.h> 17 #include <openssl/tls1.h> 18 #include <openssl/x509.h> 19 20 #include "ct_locl.h" 21 22 SCT *SCT_new(void) 23 { 24 SCT *sct = OPENSSL_zalloc(sizeof(*sct)); 25 26 if (sct == NULL) { 27 CTerr(CT_F_SCT_NEW, ERR_R_MALLOC_FAILURE); 28 return NULL; 29 } 30 31 sct->entry_type = CT_LOG_ENTRY_TYPE_NOT_SET; 32 sct->version = SCT_VERSION_NOT_SET; 33 return sct; 34 } 35 36 void SCT_free(SCT *sct) 37 { 38 if (sct == NULL) 39 return; 40 41 OPENSSL_free(sct->log_id); 42 OPENSSL_free(sct->ext); 43 OPENSSL_free(sct->sig); 44 OPENSSL_free(sct->sct); 45 OPENSSL_free(sct); 46 } 47 48 void SCT_LIST_free(STACK_OF(SCT) *a) 49 { 50 sk_SCT_pop_free(a, SCT_free); 51 } 52 53 int SCT_set_version(SCT *sct, sct_version_t version) 54 { 55 if (version != SCT_VERSION_V1) { 56 CTerr(CT_F_SCT_SET_VERSION, CT_R_UNSUPPORTED_VERSION); 57 return 0; 58 } 59 sct->version = version; 60 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET; 61 return 1; 62 } 63 64 int SCT_set_log_entry_type(SCT *sct, ct_log_entry_type_t entry_type) 65 { 66 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET; 67 68 switch (entry_type) { 69 case CT_LOG_ENTRY_TYPE_X509: 70 case CT_LOG_ENTRY_TYPE_PRECERT: 71 sct->entry_type = entry_type; 72 return 1; 73 case CT_LOG_ENTRY_TYPE_NOT_SET: 74 break; 75 } 76 CTerr(CT_F_SCT_SET_LOG_ENTRY_TYPE, CT_R_UNSUPPORTED_ENTRY_TYPE); 77 return 0; 78 } 79 80 int SCT_set0_log_id(SCT *sct, unsigned char *log_id, size_t log_id_len) 81 { 82 if (sct->version == SCT_VERSION_V1 && log_id_len != CT_V1_HASHLEN) { 83 CTerr(CT_F_SCT_SET0_LOG_ID, CT_R_INVALID_LOG_ID_LENGTH); 84 return 0; 85 } 86 87 OPENSSL_free(sct->log_id); 88 sct->log_id = log_id; 89 sct->log_id_len = log_id_len; 90 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET; 91 return 1; 92 } 93 94 int SCT_set1_log_id(SCT *sct, const unsigned char *log_id, size_t log_id_len) 95 { 96 if (sct->version == SCT_VERSION_V1 && log_id_len != CT_V1_HASHLEN) { 97 CTerr(CT_F_SCT_SET1_LOG_ID, CT_R_INVALID_LOG_ID_LENGTH); 98 return 0; 99 } 100 101 OPENSSL_free(sct->log_id); 102 sct->log_id = NULL; 103 sct->log_id_len = 0; 104 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET; 105 106 if (log_id != NULL && log_id_len > 0) { 107 sct->log_id = OPENSSL_memdup(log_id, log_id_len); 108 if (sct->log_id == NULL) { 109 CTerr(CT_F_SCT_SET1_LOG_ID, ERR_R_MALLOC_FAILURE); 110 return 0; 111 } 112 sct->log_id_len = log_id_len; 113 } 114 return 1; 115 } 116 117 118 void SCT_set_timestamp(SCT *sct, uint64_t timestamp) 119 { 120 sct->timestamp = timestamp; 121 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET; 122 } 123 124 int SCT_set_signature_nid(SCT *sct, int nid) 125 { 126 switch (nid) { 127 case NID_sha256WithRSAEncryption: 128 sct->hash_alg = TLSEXT_hash_sha256; 129 sct->sig_alg = TLSEXT_signature_rsa; 130 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET; 131 return 1; 132 case NID_ecdsa_with_SHA256: 133 sct->hash_alg = TLSEXT_hash_sha256; 134 sct->sig_alg = TLSEXT_signature_ecdsa; 135 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET; 136 return 1; 137 default: 138 CTerr(CT_F_SCT_SET_SIGNATURE_NID, CT_R_UNRECOGNIZED_SIGNATURE_NID); 139 return 0; 140 } 141 } 142 143 void SCT_set0_extensions(SCT *sct, unsigned char *ext, size_t ext_len) 144 { 145 OPENSSL_free(sct->ext); 146 sct->ext = ext; 147 sct->ext_len = ext_len; 148 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET; 149 } 150 151 int SCT_set1_extensions(SCT *sct, const unsigned char *ext, size_t ext_len) 152 { 153 OPENSSL_free(sct->ext); 154 sct->ext = NULL; 155 sct->ext_len = 0; 156 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET; 157 158 if (ext != NULL && ext_len > 0) { 159 sct->ext = OPENSSL_memdup(ext, ext_len); 160 if (sct->ext == NULL) { 161 CTerr(CT_F_SCT_SET1_EXTENSIONS, ERR_R_MALLOC_FAILURE); 162 return 0; 163 } 164 sct->ext_len = ext_len; 165 } 166 return 1; 167 } 168 169 void SCT_set0_signature(SCT *sct, unsigned char *sig, size_t sig_len) 170 { 171 OPENSSL_free(sct->sig); 172 sct->sig = sig; 173 sct->sig_len = sig_len; 174 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET; 175 } 176 177 int SCT_set1_signature(SCT *sct, const unsigned char *sig, size_t sig_len) 178 { 179 OPENSSL_free(sct->sig); 180 sct->sig = NULL; 181 sct->sig_len = 0; 182 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET; 183 184 if (sig != NULL && sig_len > 0) { 185 sct->sig = OPENSSL_memdup(sig, sig_len); 186 if (sct->sig == NULL) { 187 CTerr(CT_F_SCT_SET1_SIGNATURE, ERR_R_MALLOC_FAILURE); 188 return 0; 189 } 190 sct->sig_len = sig_len; 191 } 192 return 1; 193 } 194 195 sct_version_t SCT_get_version(const SCT *sct) 196 { 197 return sct->version; 198 } 199 200 ct_log_entry_type_t SCT_get_log_entry_type(const SCT *sct) 201 { 202 return sct->entry_type; 203 } 204 205 size_t SCT_get0_log_id(const SCT *sct, unsigned char **log_id) 206 { 207 *log_id = sct->log_id; 208 return sct->log_id_len; 209 } 210 211 uint64_t SCT_get_timestamp(const SCT *sct) 212 { 213 return sct->timestamp; 214 } 215 216 int SCT_get_signature_nid(const SCT *sct) 217 { 218 if (sct->version == SCT_VERSION_V1) { 219 if (sct->hash_alg == TLSEXT_hash_sha256) { 220 switch (sct->sig_alg) { 221 case TLSEXT_signature_ecdsa: 222 return NID_ecdsa_with_SHA256; 223 case TLSEXT_signature_rsa: 224 return NID_sha256WithRSAEncryption; 225 default: 226 return NID_undef; 227 } 228 } 229 } 230 return NID_undef; 231 } 232 233 size_t SCT_get0_extensions(const SCT *sct, unsigned char **ext) 234 { 235 *ext = sct->ext; 236 return sct->ext_len; 237 } 238 239 size_t SCT_get0_signature(const SCT *sct, unsigned char **sig) 240 { 241 *sig = sct->sig; 242 return sct->sig_len; 243 } 244 245 int SCT_is_complete(const SCT *sct) 246 { 247 switch (sct->version) { 248 case SCT_VERSION_NOT_SET: 249 return 0; 250 case SCT_VERSION_V1: 251 return sct->log_id != NULL && SCT_signature_is_complete(sct); 252 default: 253 return sct->sct != NULL; /* Just need cached encoding */ 254 } 255 } 256 257 int SCT_signature_is_complete(const SCT *sct) 258 { 259 return SCT_get_signature_nid(sct) != NID_undef && 260 sct->sig != NULL && sct->sig_len > 0; 261 } 262 263 sct_source_t SCT_get_source(const SCT *sct) 264 { 265 return sct->source; 266 } 267 268 int SCT_set_source(SCT *sct, sct_source_t source) 269 { 270 sct->source = source; 271 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET; 272 switch (source) { 273 case SCT_SOURCE_TLS_EXTENSION: 274 case SCT_SOURCE_OCSP_STAPLED_RESPONSE: 275 return SCT_set_log_entry_type(sct, CT_LOG_ENTRY_TYPE_X509); 276 case SCT_SOURCE_X509V3_EXTENSION: 277 return SCT_set_log_entry_type(sct, CT_LOG_ENTRY_TYPE_PRECERT); 278 case SCT_SOURCE_UNKNOWN: 279 break; 280 } 281 /* if we aren't sure, leave the log entry type alone */ 282 return 1; 283 } 284 285 sct_validation_status_t SCT_get_validation_status(const SCT *sct) 286 { 287 return sct->validation_status; 288 } 289 290 int SCT_validate(SCT *sct, const CT_POLICY_EVAL_CTX *ctx) 291 { 292 int is_sct_valid = -1; 293 SCT_CTX *sctx = NULL; 294 X509_PUBKEY *pub = NULL, *log_pkey = NULL; 295 const CTLOG *log; 296 297 /* 298 * With an unrecognized SCT version we don't know what such an SCT means, 299 * let alone validate one. So we return validation failure (0). 300 */ 301 if (sct->version != SCT_VERSION_V1) { 302 sct->validation_status = SCT_VALIDATION_STATUS_UNKNOWN_VERSION; 303 return 0; 304 } 305 306 log = CTLOG_STORE_get0_log_by_id(ctx->log_store, 307 sct->log_id, sct->log_id_len); 308 309 /* Similarly, an SCT from an unknown log also cannot be validated. */ 310 if (log == NULL) { 311 sct->validation_status = SCT_VALIDATION_STATUS_UNKNOWN_LOG; 312 return 0; 313 } 314 315 sctx = SCT_CTX_new(); 316 if (sctx == NULL) 317 goto err; 318 319 if (X509_PUBKEY_set(&log_pkey, CTLOG_get0_public_key(log)) != 1) 320 goto err; 321 if (SCT_CTX_set1_pubkey(sctx, log_pkey) != 1) 322 goto err; 323 324 if (SCT_get_log_entry_type(sct) == CT_LOG_ENTRY_TYPE_PRECERT) { 325 EVP_PKEY *issuer_pkey; 326 327 if (ctx->issuer == NULL) { 328 sct->validation_status = SCT_VALIDATION_STATUS_UNVERIFIED; 329 goto end; 330 } 331 332 issuer_pkey = X509_get0_pubkey(ctx->issuer); 333 334 if (X509_PUBKEY_set(&pub, issuer_pkey) != 1) 335 goto err; 336 if (SCT_CTX_set1_issuer_pubkey(sctx, pub) != 1) 337 goto err; 338 } 339 340 SCT_CTX_set_time(sctx, ctx->epoch_time_in_ms); 341 342 /* 343 * XXX: Potential for optimization. This repeats some idempotent heavy 344 * lifting on the certificate for each candidate SCT, and appears to not 345 * use any information in the SCT itself, only the certificate is 346 * processed. So it may make more sense to to do this just once, perhaps 347 * associated with the shared (by all SCTs) policy eval ctx. 348 * 349 * XXX: Failure here is global (SCT independent) and represents either an 350 * issue with the certificate (e.g. duplicate extensions) or an out of 351 * memory condition. When the certificate is incompatible with CT, we just 352 * mark the SCTs invalid, rather than report a failure to determine the 353 * validation status. That way, callbacks that want to do "soft" SCT 354 * processing will not abort handshakes with false positive internal 355 * errors. Since the function does not distinguish between certificate 356 * issues (peer's fault) and internal problems (out fault) the safe thing 357 * to do is to report a validation failure and let the callback or 358 * application decide what to do. 359 */ 360 if (SCT_CTX_set1_cert(sctx, ctx->cert, NULL) != 1) 361 sct->validation_status = SCT_VALIDATION_STATUS_UNVERIFIED; 362 else 363 sct->validation_status = SCT_CTX_verify(sctx, sct) == 1 ? 364 SCT_VALIDATION_STATUS_VALID : SCT_VALIDATION_STATUS_INVALID; 365 366 end: 367 is_sct_valid = sct->validation_status == SCT_VALIDATION_STATUS_VALID; 368 err: 369 X509_PUBKEY_free(pub); 370 X509_PUBKEY_free(log_pkey); 371 SCT_CTX_free(sctx); 372 373 return is_sct_valid; 374 } 375 376 int SCT_LIST_validate(const STACK_OF(SCT) *scts, CT_POLICY_EVAL_CTX *ctx) 377 { 378 int are_scts_valid = 1; 379 int sct_count = scts != NULL ? sk_SCT_num(scts) : 0; 380 int i; 381 382 for (i = 0; i < sct_count; ++i) { 383 int is_sct_valid = -1; 384 SCT *sct = sk_SCT_value(scts, i); 385 386 if (sct == NULL) 387 continue; 388 389 is_sct_valid = SCT_validate(sct, ctx); 390 if (is_sct_valid < 0) 391 return is_sct_valid; 392 are_scts_valid &= is_sct_valid; 393 } 394 395 return are_scts_valid; 396 } 397