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| 1 // Copyright 2013 The Chromium Authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 #include "net/cert/ct_objects_extractor.h" | |
| 6 | |
| 7 #include <cert.h> | |
| 8 #include <secasn1.h> | |
| 9 #include <secitem.h> | |
| 10 #include <secoid.h> | |
| 11 | |
| 12 #include "base/lazy_instance.h" | |
| 13 #include "base/macros.h" | |
| 14 #include "base/sha1.h" | |
| 15 #include "crypto/scoped_nss_types.h" | |
| 16 #include "crypto/sha2.h" | |
| 17 #include "net/cert/asn1_util.h" | |
| 18 #include "net/cert/scoped_nss_types.h" | |
| 19 #include "net/cert/signed_certificate_timestamp.h" | |
| 20 #include "net/der/input.h" | |
| 21 #include "net/der/parser.h" | |
| 22 | |
| 23 namespace net { | |
| 24 | |
| 25 namespace ct { | |
| 26 | |
| 27 namespace { | |
| 28 | |
| 29 // NSS black magic to get the address of externally defined template at runtime. | |
| 30 SEC_ASN1_MKSUB(SEC_IntegerTemplate) | |
| 31 SEC_ASN1_MKSUB(SECOID_AlgorithmIDTemplate) | |
| 32 SEC_ASN1_MKSUB(SEC_GeneralizedTimeTemplate) | |
| 33 SEC_ASN1_MKSUB(CERT_SequenceOfCertExtensionTemplate) | |
| 34 | |
| 35 // Wrapper class to convert a X509Certificate::OSCertHandle directly | |
| 36 // into a CERTCertificate* usable with other NSS functions. This is used for | |
| 37 // platforms where X509Certificate::OSCertHandle refers to a different type | |
| 38 // than a CERTCertificate*. | |
| 39 struct NSSCertWrapper { | |
| 40 explicit NSSCertWrapper(X509Certificate::OSCertHandle cert_handle); | |
| 41 ~NSSCertWrapper() {} | |
| 42 | |
| 43 ScopedCERTCertificate cert; | |
| 44 }; | |
| 45 | |
| 46 NSSCertWrapper::NSSCertWrapper(X509Certificate::OSCertHandle cert_handle) { | |
| 47 #if defined(USE_NSS_CERTS) | |
| 48 cert.reset(CERT_DupCertificate(cert_handle)); | |
| 49 #else | |
| 50 SECItem der_cert; | |
| 51 std::string der_data; | |
| 52 if (!X509Certificate::GetDEREncoded(cert_handle, &der_data)) | |
| 53 return; | |
| 54 der_cert.data = | |
| 55 reinterpret_cast<unsigned char*>(const_cast<char*>(der_data.data())); | |
| 56 der_cert.len = der_data.size(); | |
| 57 | |
| 58 // Note: CERT_NewTempCertificate may return NULL if the certificate | |
| 59 // shares a serial number with another cert issued by the same CA, | |
| 60 // which is not supposed to happen. | |
| 61 cert.reset(CERT_NewTempCertificate( | |
| 62 CERT_GetDefaultCertDB(), &der_cert, NULL, PR_FALSE, PR_TRUE)); | |
| 63 #endif | |
| 64 DCHECK(cert.get() != NULL); | |
| 65 } | |
| 66 | |
| 67 // The wire form of the OID 1.3.6.1.4.1.11129.2.4.2. See Section 3.3 of | |
| 68 // RFC6962. | |
| 69 const unsigned char kEmbeddedSCTOid[] = {0x2B, 0x06, 0x01, 0x04, 0x01, | |
| 70 0xD6, 0x79, 0x02, 0x04, 0x02}; | |
| 71 const char kEmbeddedSCTDescription[] = | |
| 72 "X.509v3 Certificate Transparency Embedded Signed Certificate Timestamp " | |
| 73 "List"; | |
| 74 | |
| 75 // The wire form of the OID 1.3.6.1.4.1.11129.2.4.5 - OCSP SingleExtension for | |
| 76 // X.509v3 Certificate Transparency Signed Certificate Timestamp List, see | |
| 77 // Section 3.3 of RFC6962. | |
| 78 const unsigned char kOCSPExtensionOid[] = {0x2B, 0x06, 0x01, 0x04, 0x01, | |
| 79 0xD6, 0x79, 0x02, 0x04, 0x05}; | |
| 80 | |
| 81 const SECItem kOCSPExtensionOidItem = { | |
| 82 siBuffer, const_cast<unsigned char*>(kOCSPExtensionOid), | |
| 83 sizeof(kOCSPExtensionOid) | |
| 84 }; | |
| 85 | |
| 86 // id-ad-ocsp: 1.3.6.1.5.5.7.48.1.1 | |
| 87 const unsigned char kBasicOCSPResponseOid[] = {0x2B, 0x06, 0x01, 0x05, 0x05, | |
| 88 0x07, 0x30, 0x01, 0x01}; | |
| 89 | |
| 90 const SECItem kBasicOCSPResponseOidItem = { | |
| 91 siBuffer, const_cast<unsigned char*>(kBasicOCSPResponseOid), | |
| 92 sizeof(kBasicOCSPResponseOid) | |
| 93 }; | |
| 94 | |
| 95 | |
| 96 // Initializes the necessary NSS internals for use with Certificate | |
| 97 // Transparency. | |
| 98 class CTInitSingleton { | |
| 99 public: | |
| 100 SECOidTag embedded_oid() const { return embedded_oid_; } | |
| 101 | |
| 102 private: | |
| 103 friend struct base::DefaultLazyInstanceTraits<CTInitSingleton>; | |
| 104 | |
| 105 CTInitSingleton() : embedded_oid_(SEC_OID_UNKNOWN) { | |
| 106 embedded_oid_ = RegisterOid( | |
| 107 kEmbeddedSCTOid, sizeof(kEmbeddedSCTOid), kEmbeddedSCTDescription); | |
| 108 } | |
| 109 | |
| 110 ~CTInitSingleton() {} | |
| 111 | |
| 112 SECOidTag RegisterOid(const unsigned char* oid, | |
| 113 unsigned int oid_len, | |
| 114 const char* description) { | |
| 115 SECOidData oid_data; | |
| 116 oid_data.oid.len = oid_len; | |
| 117 oid_data.oid.data = const_cast<unsigned char*>(oid); | |
| 118 oid_data.offset = SEC_OID_UNKNOWN; | |
| 119 oid_data.desc = description; | |
| 120 oid_data.mechanism = CKM_INVALID_MECHANISM; | |
| 121 // Setting this to SUPPORTED_CERT_EXTENSION ensures that if a certificate | |
| 122 // contains this extension with the critical bit set, NSS will not reject | |
| 123 // it. However, because verification of this extension happens after NSS, | |
| 124 // it is currently left as INVALID_CERT_EXTENSION. | |
| 125 oid_data.supportedExtension = INVALID_CERT_EXTENSION; | |
| 126 | |
| 127 SECOidTag result = SECOID_AddEntry(&oid_data); | |
| 128 CHECK_NE(SEC_OID_UNKNOWN, result); | |
| 129 | |
| 130 return result; | |
| 131 } | |
| 132 | |
| 133 SECOidTag embedded_oid_; | |
| 134 | |
| 135 DISALLOW_COPY_AND_ASSIGN(CTInitSingleton); | |
| 136 }; | |
| 137 | |
| 138 base::LazyInstance<CTInitSingleton>::Leaky g_ct_singleton = | |
| 139 LAZY_INSTANCE_INITIALIZER; | |
| 140 | |
| 141 // Obtains the data for an X.509v3 certificate extension identified by |oid| | |
| 142 // and encoded as an OCTET STRING. Returns true if the extension was found in | |
| 143 // the certificate, updating |ext_data| to be the extension data after removing | |
| 144 // the DER encoding of OCTET STRING. | |
| 145 bool GetCertOctetStringExtension(CERTCertificate* cert, | |
| 146 SECOidTag oid, | |
| 147 std::string* extension_data) { | |
| 148 SECItem extension; | |
| 149 SECStatus rv = CERT_FindCertExtension(cert, oid, &extension); | |
| 150 if (rv != SECSuccess) | |
| 151 return false; | |
| 152 | |
| 153 der::Parser parser(der::Input(extension.data, extension.len)); | |
| 154 der::Input parsed_extension; | |
| 155 if (!parser.ReadTag(der::kOctetString, &parsed_extension) || | |
| 156 parser.HasMore()) { // Decoding failure or raw data left | |
| 157 rv = SECFailure; | |
| 158 } else { | |
| 159 *extension_data = parsed_extension.AsString(); | |
| 160 } | |
| 161 | |
| 162 SECITEM_FreeItem(&extension, PR_FALSE); | |
| 163 return rv == SECSuccess; | |
| 164 } | |
| 165 | |
| 166 // NSS offers CERT_FindCertExtension for certificates, but that only accepts | |
| 167 // CERTCertificate* inputs, so the method below extracts the SCT extension | |
| 168 // directly from the CERTCertExtension** of an OCSP response. | |
| 169 // | |
| 170 // Obtains the data for an OCSP extension identified by kOCSPExtensionOidItem | |
| 171 // and encoded as an OCTET STRING. Returns true if the extension was found in | |
| 172 // |extensions|, updating |extension_data| to be the extension data after | |
| 173 // removing the DER encoding of OCTET STRING. | |
| 174 bool GetSCTListFromOCSPExtension(PLArenaPool* arena, | |
| 175 const CERTCertExtension* const* extensions, | |
| 176 std::string* extension_data) { | |
| 177 if (!extensions) | |
| 178 return false; | |
| 179 | |
| 180 const CERTCertExtension* match = NULL; | |
| 181 | |
| 182 for (const CERTCertExtension* const* exts = extensions; *exts; ++exts) { | |
| 183 const CERTCertExtension* ext = *exts; | |
| 184 if (SECITEM_ItemsAreEqual(&kOCSPExtensionOidItem, &ext->id)) { | |
| 185 match = ext; | |
| 186 break; | |
| 187 } | |
| 188 } | |
| 189 | |
| 190 if (!match) | |
| 191 return false; | |
| 192 | |
| 193 SECItem contents; | |
| 194 // SEC_QuickDERDecodeItem sets |contents| to point to |match|, so it is not | |
| 195 // necessary to free the contents of |contents|. | |
| 196 SECStatus rv = SEC_QuickDERDecodeItem(arena, &contents, | |
| 197 SEC_ASN1_GET(SEC_OctetStringTemplate), | |
| 198 &match->value); | |
| 199 if (rv != SECSuccess) | |
| 200 return false; | |
| 201 | |
| 202 base::StringPiece parsed_data(reinterpret_cast<char*>(contents.data), | |
| 203 contents.len); | |
| 204 parsed_data.CopyToString(extension_data); | |
| 205 return true; | |
| 206 } | |
| 207 | |
| 208 // Given a |cert|, extract the TBSCertificate from this certificate, also | |
| 209 // removing the X.509 extension with OID 1.3.6.1.4.1.11129.2.4.2 (that is, | |
| 210 // the embedded SCT) | |
| 211 bool ExtractTBSCertWithoutSCTs(CERTCertificate* cert, | |
| 212 std::string* to_be_signed) { | |
| 213 SECOidData* oid = SECOID_FindOIDByTag(g_ct_singleton.Get().embedded_oid()); | |
| 214 if (!oid) | |
| 215 return false; | |
| 216 | |
| 217 // This is a giant hack, due to the fact that NSS does not expose a good API | |
| 218 // for simply removing certificate fields from existing certificates. | |
| 219 CERTCertificate temp_cert; | |
| 220 temp_cert = *cert; | |
| 221 temp_cert.extensions = NULL; | |
| 222 | |
| 223 // Strip out the embedded SCT OID from the new certificate by directly | |
| 224 // mutating the extensions in place. | |
| 225 std::vector<CERTCertExtension*> new_extensions; | |
| 226 if (cert->extensions) { | |
| 227 for (CERTCertExtension** exts = cert->extensions; *exts; ++exts) { | |
| 228 CERTCertExtension* ext = *exts; | |
| 229 SECComparison result = SECITEM_CompareItem(&oid->oid, &ext->id); | |
| 230 if (result != SECEqual) | |
| 231 new_extensions.push_back(ext); | |
| 232 } | |
| 233 } | |
| 234 if (!new_extensions.empty()) { | |
| 235 new_extensions.push_back(NULL); | |
| 236 temp_cert.extensions = &new_extensions[0]; | |
| 237 } | |
| 238 | |
| 239 crypto::ScopedPLArenaPool arena(PORT_NewArena(DER_DEFAULT_CHUNKSIZE)); | |
| 240 | |
| 241 SECItem tbs_data; | |
| 242 tbs_data.len = 0; | |
| 243 tbs_data.data = NULL; | |
| 244 void* result = SEC_ASN1EncodeItem(arena.get(), | |
| 245 &tbs_data, | |
| 246 &temp_cert, | |
| 247 SEC_ASN1_GET(CERT_CertificateTemplate)); | |
| 248 if (!result) | |
| 249 return false; | |
| 250 | |
| 251 to_be_signed->assign(reinterpret_cast<char*>(tbs_data.data), tbs_data.len); | |
| 252 return true; | |
| 253 } | |
| 254 | |
| 255 // The following code is adapted from the NSS OCSP module, in order to expose | |
| 256 // the internal structure of an OCSP response. | |
| 257 | |
| 258 // ResponseBytes ::= SEQUENCE { | |
| 259 // responseType OBJECT IDENTIFIER, | |
| 260 // response OCTET STRING } | |
| 261 struct ResponseBytes { | |
| 262 SECItem response_type; | |
| 263 SECItem der_response; | |
| 264 }; | |
| 265 | |
| 266 const SEC_ASN1Template kResponseBytesTemplate[] = { | |
| 267 { SEC_ASN1_SEQUENCE, 0, NULL, sizeof(ResponseBytes) }, | |
| 268 { SEC_ASN1_OBJECT_ID, offsetof(ResponseBytes, response_type) }, | |
| 269 { SEC_ASN1_OCTET_STRING, offsetof(ResponseBytes, der_response) }, | |
| 270 { 0 } | |
| 271 }; | |
| 272 | |
| 273 // OCSPResponse ::= SEQUENCE { | |
| 274 // responseStatus OCSPResponseStatus, | |
| 275 // responseBytes [0] EXPLICIT ResponseBytes OPTIONAL } | |
| 276 struct OCSPResponse { | |
| 277 SECItem response_status; | |
| 278 // This indirection is needed because |response_bytes| is an optional | |
| 279 // component and we need a way to determine if it is missing. | |
| 280 ResponseBytes* response_bytes; | |
| 281 }; | |
| 282 | |
| 283 const SEC_ASN1Template kPointerToResponseBytesTemplate[] = { | |
| 284 { SEC_ASN1_POINTER, 0, kResponseBytesTemplate } | |
| 285 }; | |
| 286 | |
| 287 const SEC_ASN1Template kOCSPResponseTemplate[] = { | |
| 288 { SEC_ASN1_SEQUENCE, 0, NULL, sizeof(OCSPResponse) }, | |
| 289 { SEC_ASN1_ENUMERATED, offsetof(OCSPResponse, response_status) }, | |
| 290 { SEC_ASN1_OPTIONAL | SEC_ASN1_EXPLICIT | SEC_ASN1_CONSTRUCTED | | |
| 291 SEC_ASN1_CONTEXT_SPECIFIC | 0, offsetof(OCSPResponse, response_bytes), | |
| 292 kPointerToResponseBytesTemplate }, | |
| 293 { 0 } | |
| 294 }; | |
| 295 | |
| 296 // CertID ::= SEQUENCE { | |
| 297 // hashAlgorithm AlgorithmIdentifier, | |
| 298 // issuerNameHash OCTET STRING, -- Hash of Issuer's DN | |
| 299 // issuerKeyHash OCTET STRING, -- Hash of Issuers public key | |
| 300 // serialNumber CertificateSerialNumber } | |
| 301 struct CertID { | |
| 302 SECAlgorithmID hash_algorithm; | |
| 303 SECItem issuer_name_hash; | |
| 304 SECItem issuer_key_hash; | |
| 305 SECItem serial_number; | |
| 306 }; | |
| 307 | |
| 308 const SEC_ASN1Template kCertIDTemplate[] = { | |
| 309 { SEC_ASN1_SEQUENCE, 0, NULL, sizeof(CertID) }, | |
| 310 { SEC_ASN1_INLINE | SEC_ASN1_XTRN, offsetof(CertID, hash_algorithm), | |
| 311 SEC_ASN1_SUB(SECOID_AlgorithmIDTemplate) }, | |
| 312 { SEC_ASN1_OCTET_STRING, offsetof(CertID, issuer_name_hash) }, | |
| 313 { SEC_ASN1_OCTET_STRING, offsetof(CertID, issuer_key_hash) }, | |
| 314 { SEC_ASN1_INTEGER, offsetof(CertID, serial_number) }, | |
| 315 { 0 } | |
| 316 }; | |
| 317 | |
| 318 // SingleResponse ::= SEQUENCE { | |
| 319 // certID CertID, | |
| 320 // certStatus CertStatus, | |
| 321 // thisUpdate GeneralizedTime, | |
| 322 // nextUpdate [0] EXPLICIT GeneralizedTime OPTIONAL, | |
| 323 // singleExtensions [1] EXPLICIT Extensions OPTIONAL } | |
| 324 struct SingleResponse { | |
| 325 CertID cert_id; | |
| 326 // The following three fields are not used. | |
| 327 SECItem der_cert_status; | |
| 328 SECItem this_update; | |
| 329 SECItem next_update; | |
| 330 CERTCertExtension** single_extensions; | |
| 331 }; | |
| 332 | |
| 333 const SEC_ASN1Template kSingleResponseTemplate[] = { | |
| 334 { SEC_ASN1_SEQUENCE, 0, NULL, sizeof(SingleResponse) }, | |
| 335 { SEC_ASN1_INLINE, offsetof(SingleResponse, cert_id), kCertIDTemplate }, | |
| 336 // Really a CHOICE but we make it an ANY because we don't care about the | |
| 337 // contents of this field. | |
| 338 // TODO(ekasper): use SEC_ASN1_CHOICE. | |
| 339 { SEC_ASN1_ANY, offsetof(SingleResponse, der_cert_status) }, | |
| 340 { SEC_ASN1_GENERALIZED_TIME, offsetof(SingleResponse, this_update) }, | |
| 341 { SEC_ASN1_OPTIONAL | SEC_ASN1_EXPLICIT | | |
| 342 SEC_ASN1_CONSTRUCTED | SEC_ASN1_CONTEXT_SPECIFIC | SEC_ASN1_XTRN | 0, | |
| 343 offsetof(SingleResponse, next_update), | |
| 344 SEC_ASN1_SUB(SEC_GeneralizedTimeTemplate) }, | |
| 345 { SEC_ASN1_OPTIONAL | SEC_ASN1_EXPLICIT | SEC_ASN1_CONSTRUCTED | | |
| 346 SEC_ASN1_CONTEXT_SPECIFIC | SEC_ASN1_XTRN | 1, | |
| 347 offsetof(SingleResponse, single_extensions), | |
| 348 SEC_ASN1_SUB(CERT_SequenceOfCertExtensionTemplate) }, | |
| 349 { 0 } | |
| 350 }; | |
| 351 | |
| 352 // ResponseData ::= SEQUENCE { | |
| 353 // version [0] EXPLICIT Version DEFAULT v1, | |
| 354 // responderID ResponderID, | |
| 355 // producedAt GeneralizedTime, | |
| 356 // responses SEQUENCE OF SingleResponse, | |
| 357 // responseExtensions [1] EXPLICIT Extensions OPTIONAL } | |
| 358 struct ResponseData { | |
| 359 // The first three fields are not used. | |
| 360 SECItem version; | |
| 361 SECItem der_responder_id; | |
| 362 SECItem produced_at; | |
| 363 SingleResponse** single_responses; | |
| 364 // Skip extensions. | |
| 365 }; | |
| 366 | |
| 367 const SEC_ASN1Template kResponseDataTemplate[] = { | |
| 368 { SEC_ASN1_SEQUENCE, 0, NULL, sizeof(ResponseData) }, | |
| 369 { SEC_ASN1_OPTIONAL | SEC_ASN1_EXPLICIT | SEC_ASN1_CONSTRUCTED | | |
| 370 SEC_ASN1_CONTEXT_SPECIFIC | SEC_ASN1_XTRN | 0, | |
| 371 offsetof(ResponseData, version), SEC_ASN1_SUB(SEC_IntegerTemplate) }, | |
| 372 // Really a CHOICE but we make it an ANY because we don't care about the | |
| 373 // contents of this field. | |
| 374 // TODO(ekasper): use SEC_ASN1_CHOICE. | |
| 375 { SEC_ASN1_ANY, offsetof(ResponseData, der_responder_id) }, | |
| 376 { SEC_ASN1_GENERALIZED_TIME, offsetof(ResponseData, produced_at) }, | |
| 377 { SEC_ASN1_SEQUENCE_OF, offsetof(ResponseData, single_responses), | |
| 378 kSingleResponseTemplate }, | |
| 379 { SEC_ASN1_SKIP_REST }, | |
| 380 { 0 } | |
| 381 }; | |
| 382 | |
| 383 // BasicOCSPResponse ::= SEQUENCE { | |
| 384 // tbsResponseData ResponseData, | |
| 385 // signatureAlgorithm AlgorithmIdentifier, | |
| 386 // signature BIT STRING, | |
| 387 // certs [0] EXPLICIT SEQUENCE OF Certificate OPTIONAL } | |
| 388 struct BasicOCSPResponse { | |
| 389 ResponseData tbs_response_data; | |
| 390 // We do not care about the rest. | |
| 391 }; | |
| 392 | |
| 393 const SEC_ASN1Template kBasicOCSPResponseTemplate[] = { | |
| 394 { SEC_ASN1_SEQUENCE, 0, NULL, sizeof(BasicOCSPResponse) }, | |
| 395 { SEC_ASN1_INLINE, offsetof(BasicOCSPResponse, tbs_response_data), | |
| 396 kResponseDataTemplate }, | |
| 397 { SEC_ASN1_SKIP_REST }, | |
| 398 { 0 } | |
| 399 }; | |
| 400 | |
| 401 bool StringEqualToSECItem(const std::string& value1, const SECItem& value2) { | |
| 402 if (value1.size() != value2.len) | |
| 403 return false; | |
| 404 return memcmp(value1.data(), value2.data, value2.len) == 0; | |
| 405 } | |
| 406 | |
| 407 // TODO(ekasper): also use the issuer name hash in matching. | |
| 408 bool CertIDMatches(const CertID& cert_id, | |
| 409 const std::string& serial_number, | |
| 410 const std::string& issuer_key_sha1_hash, | |
| 411 const std::string& issuer_key_sha256_hash) { | |
| 412 if (!StringEqualToSECItem(serial_number, cert_id.serial_number)) | |
| 413 return false; | |
| 414 | |
| 415 SECOidTag hash_alg = SECOID_FindOIDTag(&cert_id.hash_algorithm.algorithm); | |
| 416 switch (hash_alg) { | |
| 417 case SEC_OID_SHA1: | |
| 418 return StringEqualToSECItem(issuer_key_sha1_hash, | |
| 419 cert_id.issuer_key_hash); | |
| 420 case SEC_OID_SHA256: | |
| 421 return StringEqualToSECItem(issuer_key_sha256_hash, | |
| 422 cert_id.issuer_key_hash); | |
| 423 default: | |
| 424 return false; | |
| 425 } | |
| 426 } | |
| 427 | |
| 428 } // namespace | |
| 429 | |
| 430 bool ExtractEmbeddedSCTList(X509Certificate::OSCertHandle cert, | |
| 431 std::string* sct_list) { | |
| 432 DCHECK(cert); | |
| 433 | |
| 434 NSSCertWrapper leaf_cert(cert); | |
| 435 if (!leaf_cert.cert) | |
| 436 return false; | |
| 437 | |
| 438 return GetCertOctetStringExtension(leaf_cert.cert.get(), | |
| 439 g_ct_singleton.Get().embedded_oid(), | |
| 440 sct_list); | |
| 441 } | |
| 442 | |
| 443 bool GetPrecertLogEntry(X509Certificate::OSCertHandle leaf, | |
| 444 X509Certificate::OSCertHandle issuer, | |
| 445 LogEntry* result) { | |
| 446 DCHECK(leaf); | |
| 447 DCHECK(issuer); | |
| 448 | |
| 449 NSSCertWrapper leaf_cert(leaf); | |
| 450 NSSCertWrapper issuer_cert(issuer); | |
| 451 | |
| 452 result->Reset(); | |
| 453 // XXX(rsleevi): This check may be overkill, since we should be able to | |
| 454 // generate precerts for certs without the extension. For now, just a sanity | |
| 455 // check to match the reference implementation. | |
| 456 SECItem extension; | |
| 457 SECStatus rv = CERT_FindCertExtension( | |
| 458 leaf_cert.cert.get(), g_ct_singleton.Get().embedded_oid(), &extension); | |
| 459 if (rv != SECSuccess) | |
| 460 return false; | |
| 461 SECITEM_FreeItem(&extension, PR_FALSE); | |
| 462 | |
| 463 std::string to_be_signed; | |
| 464 if (!ExtractTBSCertWithoutSCTs(leaf_cert.cert.get(), &to_be_signed)) | |
| 465 return false; | |
| 466 | |
| 467 if (!issuer_cert.cert) { | |
| 468 // This can happen when the issuer and leaf certs share the same serial | |
| 469 // number and are from the same CA, which should never be the case | |
| 470 // (but happened with bad test certs). | |
| 471 VLOG(1) << "Issuer cert is null, cannot generate Precert entry."; | |
| 472 return false; | |
| 473 } | |
| 474 | |
| 475 SECKEYPublicKey* issuer_pub_key = | |
| 476 SECKEY_ExtractPublicKey(&(issuer_cert.cert->subjectPublicKeyInfo)); | |
| 477 if (!issuer_pub_key) { | |
| 478 VLOG(1) << "Could not extract issuer public key, " | |
| 479 << "cannot generate Precert entry."; | |
| 480 return false; | |
| 481 } | |
| 482 | |
| 483 SECItem* encoded_issuer_pubKey = | |
| 484 SECKEY_EncodeDERSubjectPublicKeyInfo(issuer_pub_key); | |
| 485 if (!encoded_issuer_pubKey) { | |
| 486 SECKEY_DestroyPublicKey(issuer_pub_key); | |
| 487 return false; | |
| 488 } | |
| 489 | |
| 490 result->type = ct::LogEntry::LOG_ENTRY_TYPE_PRECERT; | |
| 491 result->tbs_certificate.swap(to_be_signed); | |
| 492 | |
| 493 crypto::SHA256HashString( | |
| 494 base::StringPiece(reinterpret_cast<char*>(encoded_issuer_pubKey->data), | |
| 495 encoded_issuer_pubKey->len), | |
| 496 result->issuer_key_hash.data, | |
| 497 sizeof(result->issuer_key_hash.data)); | |
| 498 | |
| 499 SECITEM_FreeItem(encoded_issuer_pubKey, PR_TRUE); | |
| 500 SECKEY_DestroyPublicKey(issuer_pub_key); | |
| 501 | |
| 502 return true; | |
| 503 } | |
| 504 | |
| 505 bool GetX509LogEntry(X509Certificate::OSCertHandle leaf, LogEntry* result) { | |
| 506 DCHECK(leaf); | |
| 507 | |
| 508 std::string encoded; | |
| 509 if (!X509Certificate::GetDEREncoded(leaf, &encoded)) | |
| 510 return false; | |
| 511 | |
| 512 result->Reset(); | |
| 513 result->type = ct::LogEntry::LOG_ENTRY_TYPE_X509; | |
| 514 result->leaf_certificate.swap(encoded); | |
| 515 return true; | |
| 516 } | |
| 517 | |
| 518 bool ExtractSCTListFromOCSPResponse(X509Certificate::OSCertHandle issuer, | |
| 519 const std::string& cert_serial_number, | |
| 520 const std::string& ocsp_response, | |
| 521 std::string* sct_list) { | |
| 522 DCHECK(issuer); | |
| 523 | |
| 524 // Any OCSP response is unlikely to be even close to 2^24 bytes; further, CT | |
| 525 // only uses stapled OCSP responses which have this limit imposed by the TLS | |
| 526 // protocol. | |
| 527 if (ocsp_response.size() > 0xffffff) | |
| 528 return false; | |
| 529 | |
| 530 crypto::ScopedPLArenaPool arena(PORT_NewArena(DER_DEFAULT_CHUNKSIZE)); | |
| 531 | |
| 532 OCSPResponse response; | |
| 533 memset(&response, 0, sizeof(response)); | |
| 534 | |
| 535 SECItem src = { siBuffer, | |
| 536 reinterpret_cast<unsigned char*>(const_cast<char*>( | |
| 537 ocsp_response.data())), | |
| 538 static_cast<unsigned int>(ocsp_response.size()) }; | |
| 539 | |
| 540 // |response| will point directly into |src|, so it's not necessary to | |
| 541 // free the |response| contents, but they may only be used while |src| | |
| 542 // is valid (i.e., in this method). | |
| 543 SECStatus rv = SEC_QuickDERDecodeItem(arena.get(), &response, | |
| 544 kOCSPResponseTemplate, &src); | |
| 545 if (rv != SECSuccess) | |
| 546 return false; | |
| 547 | |
| 548 if (!response.response_bytes) | |
| 549 return false; | |
| 550 | |
| 551 if (!SECITEM_ItemsAreEqual(&kBasicOCSPResponseOidItem, | |
| 552 &response.response_bytes->response_type)) { | |
| 553 return false; | |
| 554 } | |
| 555 | |
| 556 BasicOCSPResponse basic_response; | |
| 557 memset(&basic_response, 0, sizeof(basic_response)); | |
| 558 | |
| 559 rv = SEC_QuickDERDecodeItem(arena.get(), &basic_response, | |
| 560 kBasicOCSPResponseTemplate, | |
| 561 &response.response_bytes->der_response); | |
| 562 if (rv != SECSuccess) | |
| 563 return false; | |
| 564 | |
| 565 SingleResponse** responses = | |
| 566 basic_response.tbs_response_data.single_responses; | |
| 567 if (!responses) | |
| 568 return false; | |
| 569 | |
| 570 std::string issuer_der; | |
| 571 if (!X509Certificate::GetDEREncoded(issuer, &issuer_der)) | |
| 572 return false; | |
| 573 | |
| 574 base::StringPiece issuer_spki; | |
| 575 if (!asn1::ExtractSPKIFromDERCert(issuer_der, &issuer_spki)) | |
| 576 return false; | |
| 577 | |
| 578 // In OCSP, only the key itself is under hash. | |
| 579 base::StringPiece issuer_spk; | |
| 580 if (!asn1::ExtractSubjectPublicKeyFromSPKI(issuer_spki, &issuer_spk)) | |
| 581 return false; | |
| 582 | |
| 583 // ExtractSubjectPublicKey... does not remove the initial octet encoding the | |
| 584 // number of unused bits in the ASN.1 BIT STRING so we do it here. For public | |
| 585 // keys, the bitstring is in practice always byte-aligned. | |
| 586 if (issuer_spk.empty() || issuer_spk[0] != 0) | |
| 587 return false; | |
| 588 issuer_spk.remove_prefix(1); | |
| 589 | |
| 590 // NSS OCSP lib recognizes SHA1, MD5 and MD2; MD5 and MD2 are dead but | |
| 591 // https://bugzilla.mozilla.org/show_bug.cgi?id=663315 will add SHA-256 | |
| 592 // and SHA-384. | |
| 593 // TODO(ekasper): add SHA-384 to crypto/sha2.h and here if it proves | |
| 594 // necessary. | |
| 595 // TODO(ekasper): only compute the hashes on demand. | |
| 596 std::string issuer_key_sha256_hash = crypto::SHA256HashString(issuer_spk); | |
| 597 std::string issuer_key_sha1_hash = base::SHA1HashString( | |
| 598 issuer_spk.as_string()); | |
| 599 | |
| 600 const SingleResponse* match = NULL; | |
| 601 for (const SingleResponse* const* resps = responses; *resps; ++resps) { | |
| 602 const SingleResponse* resp = *resps; | |
| 603 if (CertIDMatches(resp->cert_id, cert_serial_number, | |
| 604 issuer_key_sha1_hash, issuer_key_sha256_hash)) { | |
| 605 match = resp; | |
| 606 break; | |
| 607 } | |
| 608 } | |
| 609 | |
| 610 if (!match) | |
| 611 return false; | |
| 612 | |
| 613 return GetSCTListFromOCSPExtension(arena.get(), match->single_extensions, | |
| 614 sct_list); | |
| 615 } | |
| 616 | |
| 617 } // namespace ct | |
| 618 | |
| 619 } // namespace net | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 1882433002:
Removing NSS files and USE_OPENSSL flag (Closed)
Base URL: https://chromium.googlesource.com/chromium/src.git@master