net/cert/cert_verify_proc_win.cc

   1 // Copyright (c) 2012 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/cert_verify_proc_win.h"
   6
   7 #include <string>
   8 #include <vector>
   9
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/sha1.h"
  12 #include "base/strings/string_util.h"
  13 #include "base/strings/utf_string_conversions.h"
  14 #include "crypto/capi_util.h"
  15 #include "crypto/scoped_capi_types.h"
  16 #include "crypto/sha2.h"
  17 #include "net/base/net_errors.h"
  18 #include "net/cert/asn1_util.h"
  19 #include "net/cert/cert_status_flags.h"
  20 #include "net/cert/cert_verifier.h"
  21 #include "net/cert/cert_verify_result.h"
  22 #include "net/cert/crl_set.h"
  23 #include "net/cert/ev_root_ca_metadata.h"
  24 #include "net/cert/test_root_certs.h"
  25 #include "net/cert/x509_certificate.h"
  26 #include "net/cert/x509_certificate_known_roots_win.h"
  27
  28 #pragma comment(lib, "crypt32.lib")
  29
  30 #if !defined(CERT_TRUST_HAS_WEAK_SIGNATURE)
  31 // This was introduced in Windows 8 / Windows Server 2012, but retroactively
  32 // ported as far back as Windows XP via system update.
  33 #define CERT_TRUST_HAS_WEAK_SIGNATURE 0x00100000
  34 #endif
  35
  36 namespace net {
  37
  38 namespace {
  39
  40 struct FreeChainEngineFunctor {
  41   void operator()(HCERTCHAINENGINE engine) const {
  42     if (engine)
  43       CertFreeCertificateChainEngine(engine);
  44   }
  45 };
  46
  47 struct FreeCertChainContextFunctor {
  48   void operator()(PCCERT_CHAIN_CONTEXT chain_context) const {
  49     if (chain_context)
  50       CertFreeCertificateChain(chain_context);
  51   }
  52 };
  53
  54 struct FreeCertContextFunctor {
  55   void operator()(PCCERT_CONTEXT context) const {
  56     if (context)
  57       CertFreeCertificateContext(context);
  58   }
  59 };
  60
  61 typedef crypto::ScopedCAPIHandle<HCERTCHAINENGINE, FreeChainEngineFunctor>
  62     ScopedHCERTCHAINENGINE;
  63
  64 typedef scoped_ptr_malloc<const CERT_CHAIN_CONTEXT,
  65                           FreeCertChainContextFunctor>
  66     ScopedPCCERT_CHAIN_CONTEXT;
  67
  68 typedef scoped_ptr_malloc<const CERT_CONTEXT,
  69                           FreeCertContextFunctor> ScopedPCCERT_CONTEXT;
  70
  71 //-----------------------------------------------------------------------------
  72
  73 int MapSecurityError(SECURITY_STATUS err) {
  74   // There are numerous security error codes, but these are the ones we thus
  75   // far find interesting.
  76   switch (err) {
  77     case SEC_E_WRONG_PRINCIPAL:  // Schannel
  78     case CERT_E_CN_NO_MATCH:  // CryptoAPI
  79       return ERR_CERT_COMMON_NAME_INVALID;
  80     case SEC_E_UNTRUSTED_ROOT:  // Schannel
  81     case CERT_E_UNTRUSTEDROOT:  // CryptoAPI
  82       return ERR_CERT_AUTHORITY_INVALID;
  83     case SEC_E_CERT_EXPIRED:  // Schannel
  84     case CERT_E_EXPIRED:  // CryptoAPI
  85       return ERR_CERT_DATE_INVALID;
  86     case CRYPT_E_NO_REVOCATION_CHECK:
  87       return ERR_CERT_NO_REVOCATION_MECHANISM;
  88     case CRYPT_E_REVOCATION_OFFLINE:
  89       return ERR_CERT_UNABLE_TO_CHECK_REVOCATION;
  90     case CRYPT_E_REVOKED:  // Schannel and CryptoAPI
  91       return ERR_CERT_REVOKED;
  92     case SEC_E_CERT_UNKNOWN:
  93     case CERT_E_ROLE:
  94       return ERR_CERT_INVALID;
  95     case CERT_E_WRONG_USAGE:
  96       // TODO(wtc): Should we add ERR_CERT_WRONG_USAGE?
  97       return ERR_CERT_INVALID;
  98     // We received an unexpected_message or illegal_parameter alert message
  99     // from the server.
 100     case SEC_E_ILLEGAL_MESSAGE:
 101       return ERR_SSL_PROTOCOL_ERROR;
 102     case SEC_E_ALGORITHM_MISMATCH:
 103       return ERR_SSL_VERSION_OR_CIPHER_MISMATCH;
 104     case SEC_E_INVALID_HANDLE:
 105       return ERR_UNEXPECTED;
 106     case SEC_E_OK:
 107       return OK;
 108     default:
 109       LOG(WARNING) << "Unknown error " << err << " mapped to net::ERR_FAILED";
 110       return ERR_FAILED;
 111   }
 112 }
 113
 114 // Map the errors in the chain_context->TrustStatus.dwErrorStatus returned by
 115 // CertGetCertificateChain to our certificate status flags.
 116 int MapCertChainErrorStatusToCertStatus(DWORD error_status) {
 117   CertStatus cert_status = 0;
 118
 119   // We don't include CERT_TRUST_IS_NOT_TIME_NESTED because it's obsolete and
 120   // we wouldn't consider it an error anyway
 121   const DWORD kDateInvalidErrors = CERT_TRUST_IS_NOT_TIME_VALID |
 122                                    CERT_TRUST_CTL_IS_NOT_TIME_VALID;
 123   if (error_status & kDateInvalidErrors)
 124     cert_status |= CERT_STATUS_DATE_INVALID;
 125
 126   const DWORD kAuthorityInvalidErrors = CERT_TRUST_IS_UNTRUSTED_ROOT |
 127                                         CERT_TRUST_IS_EXPLICIT_DISTRUST |
 128                                         CERT_TRUST_IS_PARTIAL_CHAIN;
 129   if (error_status & kAuthorityInvalidErrors)
 130     cert_status |= CERT_STATUS_AUTHORITY_INVALID;
 131
 132   if ((error_status & CERT_TRUST_REVOCATION_STATUS_UNKNOWN) &&
 133       !(error_status & CERT_TRUST_IS_OFFLINE_REVOCATION))
 134     cert_status |= CERT_STATUS_NO_REVOCATION_MECHANISM;
 135
 136   if (error_status & CERT_TRUST_IS_OFFLINE_REVOCATION)
 137     cert_status |= CERT_STATUS_UNABLE_TO_CHECK_REVOCATION;
 138
 139   if (error_status & CERT_TRUST_IS_REVOKED)
 140     cert_status |= CERT_STATUS_REVOKED;
 141
 142   const DWORD kWrongUsageErrors = CERT_TRUST_IS_NOT_VALID_FOR_USAGE |
 143                                   CERT_TRUST_CTL_IS_NOT_VALID_FOR_USAGE;
 144   if (error_status & kWrongUsageErrors) {
 145     // TODO(wtc): Should we add CERT_STATUS_WRONG_USAGE?
 146     cert_status |= CERT_STATUS_INVALID;
 147   }
 148
 149   if (error_status & CERT_TRUST_IS_NOT_SIGNATURE_VALID) {
 150     // Check for a signature that does not meet the OS criteria for strong
 151     // signatures.
 152     // Note: These checks may be more restrictive than the current weak key
 153     // criteria implemented within CertVerifier, such as excluding SHA-1 or
 154     // excluding RSA keys < 2048 bits. However, if the user has configured
 155     // these more stringent checks, respect that configuration and err on the
 156     // more restrictive criteria.
 157     if (error_status & CERT_TRUST_HAS_WEAK_SIGNATURE) {
 158       cert_status |= CERT_STATUS_WEAK_KEY;
 159     } else {
 160       cert_status |= CERT_STATUS_INVALID;
 161     }
 162   }
 163
 164   // The rest of the errors.
 165   const DWORD kCertInvalidErrors =
 166       CERT_TRUST_IS_CYCLIC |
 167       CERT_TRUST_INVALID_EXTENSION |
 168       CERT_TRUST_INVALID_POLICY_CONSTRAINTS |
 169       CERT_TRUST_INVALID_BASIC_CONSTRAINTS |
 170       CERT_TRUST_INVALID_NAME_CONSTRAINTS |
 171       CERT_TRUST_CTL_IS_NOT_SIGNATURE_VALID |
 172       CERT_TRUST_HAS_NOT_SUPPORTED_NAME_CONSTRAINT |
 173       CERT_TRUST_HAS_NOT_DEFINED_NAME_CONSTRAINT |
 174       CERT_TRUST_HAS_NOT_PERMITTED_NAME_CONSTRAINT |
 175       CERT_TRUST_HAS_EXCLUDED_NAME_CONSTRAINT |
 176       CERT_TRUST_NO_ISSUANCE_CHAIN_POLICY |
 177       CERT_TRUST_HAS_NOT_SUPPORTED_CRITICAL_EXT;
 178   if (error_status & kCertInvalidErrors)
 179     cert_status |= CERT_STATUS_INVALID;
 180
 181   return cert_status;
 182 }
 183
 184 // Returns true if any common name in the certificate's Subject field contains
 185 // a NULL character.
 186 bool CertSubjectCommonNameHasNull(PCCERT_CONTEXT cert) {
 187   CRYPT_DECODE_PARA decode_para;
 188   decode_para.cbSize = sizeof(decode_para);
 189   decode_para.pfnAlloc = crypto::CryptAlloc;
 190   decode_para.pfnFree = crypto::CryptFree;
 191   CERT_NAME_INFO* name_info = NULL;
 192   DWORD name_info_size = 0;
 193   BOOL rv;
 194   rv = CryptDecodeObjectEx(X509_ASN_ENCODING | PKCS_7_ASN_ENCODING,
 195                            X509_NAME,
 196                            cert->pCertInfo->Subject.pbData,
 197                            cert->pCertInfo->Subject.cbData,
 198                            CRYPT_DECODE_ALLOC_FLAG | CRYPT_DECODE_NOCOPY_FLAG,
 199                            &decode_para,
 200                            &name_info,
 201                            &name_info_size);
 202   if (rv) {
 203     scoped_ptr_malloc<CERT_NAME_INFO> scoped_name_info(name_info);
 204
 205     // The Subject field may have multiple common names.  According to the
 206     // "PKI Layer Cake" paper, CryptoAPI uses every common name in the
 207     // Subject field, so we inspect every common name.
 208     //
 209     // From RFC 5280:
 210     // X520CommonName ::= CHOICE {
 211     //       teletexString     TeletexString   (SIZE (1..ub-common-name)),
 212     //       printableString   PrintableString (SIZE (1..ub-common-name)),
 213     //       universalString   UniversalString (SIZE (1..ub-common-name)),
 214     //       utf8String        UTF8String      (SIZE (1..ub-common-name)),
 215     //       bmpString         BMPString       (SIZE (1..ub-common-name)) }
 216     //
 217     // We also check IA5String and VisibleString.
 218     for (DWORD i = 0; i < name_info->cRDN; ++i) {
 219       PCERT_RDN rdn = &name_info->rgRDN[i];
 220       for (DWORD j = 0; j < rdn->cRDNAttr; ++j) {
 221         PCERT_RDN_ATTR rdn_attr = &rdn->rgRDNAttr[j];
 222         if (strcmp(rdn_attr->pszObjId, szOID_COMMON_NAME) == 0) {
 223           switch (rdn_attr->dwValueType) {
 224             // After the CryptoAPI ASN.1 security vulnerabilities described in
 225             // http://www.microsoft.com/technet/security/Bulletin/MS09-056.mspx
 226             // were patched, we get CERT_RDN_ENCODED_BLOB for a common name
 227             // that contains a NULL character.
 228             case CERT_RDN_ENCODED_BLOB:
 229               break;
 230             // Array of 8-bit characters.
 231             case CERT_RDN_PRINTABLE_STRING:
 232             case CERT_RDN_TELETEX_STRING:
 233             case CERT_RDN_IA5_STRING:
 234             case CERT_RDN_VISIBLE_STRING:
 235               for (DWORD k = 0; k < rdn_attr->Value.cbData; ++k) {
 236                 if (rdn_attr->Value.pbData[k] == '\0')
 237                   return true;
 238               }
 239               break;
 240             // Array of 16-bit characters.
 241             case CERT_RDN_BMP_STRING:
 242             case CERT_RDN_UTF8_STRING: {
 243               DWORD num_wchars = rdn_attr->Value.cbData / 2;
 244               wchar_t* common_name =
 245                   reinterpret_cast<wchar_t*>(rdn_attr->Value.pbData);
 246               for (DWORD k = 0; k < num_wchars; ++k) {
 247                 if (common_name[k] == L'\0')
 248                   return true;
 249               }
 250               break;
 251             }
 252             // Array of ints (32-bit).
 253             case CERT_RDN_UNIVERSAL_STRING: {
 254               DWORD num_ints = rdn_attr->Value.cbData / 4;
 255               int* common_name =
 256                   reinterpret_cast<int*>(rdn_attr->Value.pbData);
 257               for (DWORD k = 0; k < num_ints; ++k) {
 258                 if (common_name[k] == 0)
 259                   return true;
 260               }
 261               break;
 262             }
 263             default:
 264               NOTREACHED();
 265               break;
 266           }
 267         }
 268       }
 269     }
 270   }
 271   return false;
 272 }
 273
 274 // IsIssuedByKnownRoot returns true if the given chain is rooted at a root CA
 275 // which we recognise as a standard root.
 276 // static
 277 bool IsIssuedByKnownRoot(PCCERT_CHAIN_CONTEXT chain_context) {
 278   PCERT_SIMPLE_CHAIN first_chain = chain_context->rgpChain[0];
 279   int num_elements = first_chain->cElement;
 280   if (num_elements < 1)
 281     return false;
 282   PCERT_CHAIN_ELEMENT* element = first_chain->rgpElement;
 283   PCCERT_CONTEXT cert = element[num_elements - 1]->pCertContext;
 284
 285   SHA1HashValue hash = X509Certificate::CalculateFingerprint(cert);
 286   return IsSHA1HashInSortedArray(
 287       hash, &kKnownRootCertSHA1Hashes[0][0], sizeof(kKnownRootCertSHA1Hashes));
 288 }
 289
 290 // Saves some information about the certificate chain |chain_context| in
 291 // |*verify_result|. The caller MUST initialize |*verify_result| before
 292 // calling this function.
 293 void GetCertChainInfo(PCCERT_CHAIN_CONTEXT chain_context,
 294                       CertVerifyResult* verify_result) {
 295   if (chain_context->cChain == 0)
 296     return;
 297
 298   PCERT_SIMPLE_CHAIN first_chain = chain_context->rgpChain[0];
 299   int num_elements = first_chain->cElement;
 300   PCERT_CHAIN_ELEMENT* element = first_chain->rgpElement;
 301
 302   PCCERT_CONTEXT verified_cert = NULL;
 303   std::vector<PCCERT_CONTEXT> verified_chain;
 304
 305   bool has_root_ca = num_elements > 1 &&
 306       !(chain_context->TrustStatus.dwErrorStatus &
 307           CERT_TRUST_IS_PARTIAL_CHAIN);
 308
 309   // Each chain starts with the end entity certificate (i = 0) and ends with
 310   // either the root CA certificate or the last available intermediate. If a
 311   // root CA certificate is present, do not inspect the signature algorithm of
 312   // the root CA certificate because the signature on the trust anchor is not
 313   // important.
 314   if (has_root_ca) {
 315     // If a full chain was constructed, regardless of whether it was trusted,
 316     // don't inspect the root's signature algorithm.
 317     num_elements -= 1;
 318   }
 319
 320   for (int i = 0; i < num_elements; ++i) {
 321     PCCERT_CONTEXT cert = element[i]->pCertContext;
 322     if (i == 0) {
 323       verified_cert = cert;
 324     } else {
 325       verified_chain.push_back(cert);
 326     }
 327
 328     const char* algorithm = cert->pCertInfo->SignatureAlgorithm.pszObjId;
 329     if (strcmp(algorithm, szOID_RSA_MD5RSA) == 0) {
 330       // md5WithRSAEncryption: 1.2.840.113549.1.1.4
 331       verify_result->has_md5 = true;
 332     } else if (strcmp(algorithm, szOID_RSA_MD2RSA) == 0) {
 333       // md2WithRSAEncryption: 1.2.840.113549.1.1.2
 334       verify_result->has_md2 = true;
 335     } else if (strcmp(algorithm, szOID_RSA_MD4RSA) == 0) {
 336       // md4WithRSAEncryption: 1.2.840.113549.1.1.3
 337       verify_result->has_md4 = true;
 338     }
 339   }
 340
 341   if (verified_cert) {
 342     // Add the root certificate, if present, as it was not added above.
 343     if (has_root_ca)
 344       verified_chain.push_back(element[num_elements]->pCertContext);
 345     verify_result->verified_cert =
 346           X509Certificate::CreateFromHandle(verified_cert, verified_chain);
 347   }
 348 }
 349
 350 // Decodes the cert's certificatePolicies extension into a CERT_POLICIES_INFO
 351 // structure and stores it in *output.
 352 void GetCertPoliciesInfo(PCCERT_CONTEXT cert,
 353                          scoped_ptr_malloc<CERT_POLICIES_INFO>* output) {
 354   PCERT_EXTENSION extension = CertFindExtension(szOID_CERT_POLICIES,
 355                                                 cert->pCertInfo->cExtension,
 356                                                 cert->pCertInfo->rgExtension);
 357   if (!extension)
 358     return;
 359
 360   CRYPT_DECODE_PARA decode_para;
 361   decode_para.cbSize = sizeof(decode_para);
 362   decode_para.pfnAlloc = crypto::CryptAlloc;
 363   decode_para.pfnFree = crypto::CryptFree;
 364   CERT_POLICIES_INFO* policies_info = NULL;
 365   DWORD policies_info_size = 0;
 366   BOOL rv;
 367   rv = CryptDecodeObjectEx(X509_ASN_ENCODING | PKCS_7_ASN_ENCODING,
 368                            szOID_CERT_POLICIES,
 369                            extension->Value.pbData,
 370                            extension->Value.cbData,
 371                            CRYPT_DECODE_ALLOC_FLAG | CRYPT_DECODE_NOCOPY_FLAG,
 372                            &decode_para,
 373                            &policies_info,
 374                            &policies_info_size);
 375   if (rv)
 376     output->reset(policies_info);
 377 }
 378
 379 enum CRLSetResult {
 380   kCRLSetOk,
 381   kCRLSetUnknown,
 382   kCRLSetRevoked,
 383 };
 384
 385 // CheckRevocationWithCRLSet attempts to check each element of |chain|
 386 // against |crl_set|. It returns:
 387 //   kCRLSetRevoked: if any element of the chain is known to have been revoked.
 388 //   kCRLSetUnknown: if there is no fresh information about some element in
 389 //       the chain.
 390 //   kCRLSetOk: if every element in the chain is covered by a fresh CRLSet and
 391 //       is unrevoked.
 392 CRLSetResult CheckRevocationWithCRLSet(PCCERT_CHAIN_CONTEXT chain,
 393                                        CRLSet* crl_set) {
 394   if (chain->cChain == 0)
 395     return kCRLSetOk;
 396
 397   const PCERT_SIMPLE_CHAIN first_chain = chain->rgpChain[0];
 398   const PCERT_CHAIN_ELEMENT* element = first_chain->rgpElement;
 399
 400   const int num_elements = first_chain->cElement;
 401   if (num_elements == 0)
 402     return kCRLSetOk;
 403
 404   bool covered = true;
 405
 406   // We iterate from the root certificate down to the leaf, keeping track of
 407   // the issuer's SPKI at each step.
 408   std::string issuer_spki_hash;
 409   for (int i = num_elements - 1; i >= 0; i--) {
 410     PCCERT_CONTEXT cert = element[i]->pCertContext;
 411
 412     base::StringPiece der_bytes(
 413         reinterpret_cast<const char*>(cert->pbCertEncoded),
 414         cert->cbCertEncoded);
 415
 416     base::StringPiece spki;
 417     if (!asn1::ExtractSPKIFromDERCert(der_bytes, &spki)) {
 418       NOTREACHED();
 419       covered = false;
 420       continue;
 421     }
 422
 423     const std::string spki_hash = crypto::SHA256HashString(spki);
 424
 425     const CRYPT_INTEGER_BLOB* serial_blob = &cert->pCertInfo->SerialNumber;
 426     scoped_ptr<uint8[]> serial_bytes(new uint8[serial_blob->cbData]);
 427     // The bytes of the serial number are stored little-endian.
 428     for (unsigned j = 0; j < serial_blob->cbData; j++)
 429       serial_bytes[j] = serial_blob->pbData[serial_blob->cbData - j - 1];
 430     base::StringPiece serial(reinterpret_cast<const char*>(serial_bytes.get()),
 431                              serial_blob->cbData);
 432
 433     CRLSet::Result result = crl_set->CheckSPKI(spki_hash);
 434
 435     if (result != CRLSet::REVOKED && !issuer_spki_hash.empty())
 436       result = crl_set->CheckSerial(serial, issuer_spki_hash);
 437
 438     issuer_spki_hash = spki_hash;
 439
 440     switch (result) {
 441       case CRLSet::REVOKED:
 442         return kCRLSetRevoked;
 443       case CRLSet::UNKNOWN:
 444         covered = false;
 445         continue;
 446       case CRLSet::GOOD:
 447         continue;
 448       default:
 449         NOTREACHED();
 450         covered = false;
 451         continue;
 452     }
 453   }
 454
 455   if (!covered || crl_set->IsExpired())
 456     return kCRLSetUnknown;
 457   return kCRLSetOk;
 458 }
 459
 460 void AppendPublicKeyHashes(PCCERT_CHAIN_CONTEXT chain,
 461                            HashValueVector* hashes) {
 462   if (chain->cChain == 0)
 463     return;
 464
 465   PCERT_SIMPLE_CHAIN first_chain = chain->rgpChain[0];
 466   PCERT_CHAIN_ELEMENT* const element = first_chain->rgpElement;
 467
 468   const DWORD num_elements = first_chain->cElement;
 469   for (DWORD i = 0; i < num_elements; i++) {
 470     PCCERT_CONTEXT cert = element[i]->pCertContext;
 471
 472     base::StringPiece der_bytes(
 473         reinterpret_cast<const char*>(cert->pbCertEncoded),
 474         cert->cbCertEncoded);
 475     base::StringPiece spki_bytes;
 476     if (!asn1::ExtractSPKIFromDERCert(der_bytes, &spki_bytes))
 477       continue;
 478
 479     HashValue sha1(HASH_VALUE_SHA1);
 480     base::SHA1HashBytes(reinterpret_cast<const uint8*>(spki_bytes.data()),
 481                         spki_bytes.size(), sha1.data());
 482     hashes->push_back(sha1);
 483
 484     HashValue sha256(HASH_VALUE_SHA256);
 485     crypto::SHA256HashString(spki_bytes, sha256.data(), crypto::kSHA256Length);
 486     hashes->push_back(sha256);
 487   }
 488 }
 489
 490 // Returns true if the certificate is an extended-validation certificate.
 491 //
 492 // This function checks the certificatePolicies extensions of the
 493 // certificates in the certificate chain according to Section 7 (pp. 11-12)
 494 // of the EV Certificate Guidelines Version 1.0 at
 495 // http://cabforum.org/EV_Certificate_Guidelines.pdf.
 496 bool CheckEV(PCCERT_CHAIN_CONTEXT chain_context,
 497              bool rev_checking_enabled,
 498              const char* policy_oid) {
 499   DCHECK_NE(static_cast<DWORD>(0), chain_context->cChain);
 500   // If the cert doesn't match any of the policies, the
 501   // CERT_TRUST_IS_NOT_VALID_FOR_USAGE bit (0x10) in
 502   // chain_context->TrustStatus.dwErrorStatus is set.
 503   DWORD error_status = chain_context->TrustStatus.dwErrorStatus;
 504
 505   if (!rev_checking_enabled) {
 506     // If online revocation checking is disabled then we will have still
 507     // requested that the revocation cache be checked. However, that will often
 508     // cause the following two error bits to be set. These error bits mean that
 509     // the local OCSP/CRL is stale or missing entries for these certificates.
 510     // Since they are expected, we mask them away.
 511     error_status &= ~(CERT_TRUST_IS_OFFLINE_REVOCATION |
 512                       CERT_TRUST_REVOCATION_STATUS_UNKNOWN);
 513   }
 514   if (!chain_context->cChain || error_status != CERT_TRUST_NO_ERROR)
 515     return false;
 516
 517   // Check the end certificate simple chain (chain_context->rgpChain[0]).
 518   // If the end certificate's certificatePolicies extension contains the
 519   // EV policy OID of the root CA, return true.
 520   PCERT_CHAIN_ELEMENT* element = chain_context->rgpChain[0]->rgpElement;
 521   int num_elements = chain_context->rgpChain[0]->cElement;
 522   if (num_elements < 2)
 523     return false;
 524
 525   // Look up the EV policy OID of the root CA.
 526   PCCERT_CONTEXT root_cert = element[num_elements - 1]->pCertContext;
 527   SHA1HashValue fingerprint =
 528       X509Certificate::CalculateFingerprint(root_cert);
 529   EVRootCAMetadata* metadata = EVRootCAMetadata::GetInstance();
 530   return metadata->HasEVPolicyOID(fingerprint, policy_oid);
 531 }
 532
 533 }  // namespace
 534
 535 CertVerifyProcWin::CertVerifyProcWin() {}
 536
 537 CertVerifyProcWin::~CertVerifyProcWin() {}
 538
 539 bool CertVerifyProcWin::SupportsAdditionalTrustAnchors() const {
 540   return false;
 541 }
 542
 543 int CertVerifyProcWin::VerifyInternal(
 544     X509Certificate* cert,
 545     const std::string& hostname,
 546     int flags,
 547     CRLSet* crl_set,
 548     const CertificateList& additional_trust_anchors,
 549     CertVerifyResult* verify_result) {
 550   PCCERT_CONTEXT cert_handle = cert->os_cert_handle();
 551   if (!cert_handle)
 552     return ERR_UNEXPECTED;
 553
 554   // Build and validate certificate chain.
 555   CERT_CHAIN_PARA chain_para;
 556   memset(&chain_para, 0, sizeof(chain_para));
 557   chain_para.cbSize = sizeof(chain_para);
 558   // ExtendedKeyUsage.
 559   // We still need to request szOID_SERVER_GATED_CRYPTO and szOID_SGC_NETSCAPE
 560   // today because some certificate chains need them.  IE also requests these
 561   // two usages.
 562   static const LPSTR usage[] = {
 563     szOID_PKIX_KP_SERVER_AUTH,
 564     szOID_SERVER_GATED_CRYPTO,
 565     szOID_SGC_NETSCAPE
 566   };
 567   chain_para.RequestedUsage.dwType = USAGE_MATCH_TYPE_OR;
 568   chain_para.RequestedUsage.Usage.cUsageIdentifier = arraysize(usage);
 569   chain_para.RequestedUsage.Usage.rgpszUsageIdentifier =
 570       const_cast<LPSTR*>(usage);
 571
 572   // Get the certificatePolicies extension of the certificate.
 573   scoped_ptr_malloc<CERT_POLICIES_INFO> policies_info;
 574   LPSTR ev_policy_oid = NULL;
 575   if (flags & CertVerifier::VERIFY_EV_CERT) {
 576     GetCertPoliciesInfo(cert_handle, &policies_info);
 577     if (policies_info.get()) {
 578       EVRootCAMetadata* metadata = EVRootCAMetadata::GetInstance();
 579       for (DWORD i = 0; i < policies_info->cPolicyInfo; ++i) {
 580         LPSTR policy_oid = policies_info->rgPolicyInfo[i].pszPolicyIdentifier;
 581         if (metadata->IsEVPolicyOID(policy_oid)) {
 582           ev_policy_oid = policy_oid;
 583           chain_para.RequestedIssuancePolicy.dwType = USAGE_MATCH_TYPE_AND;
 584           chain_para.RequestedIssuancePolicy.Usage.cUsageIdentifier = 1;
 585           chain_para.RequestedIssuancePolicy.Usage.rgpszUsageIdentifier =
 586               &ev_policy_oid;
 587           break;
 588         }
 589       }
 590     }
 591   }
 592
 593   // We can set CERT_CHAIN_RETURN_LOWER_QUALITY_CONTEXTS to get more chains.
 594   DWORD chain_flags = CERT_CHAIN_CACHE_END_CERT |
 595                       CERT_CHAIN_REVOCATION_CHECK_CHAIN_EXCLUDE_ROOT;
 596   bool rev_checking_enabled =
 597       (flags & CertVerifier::VERIFY_REV_CHECKING_ENABLED);
 598
 599   if (rev_checking_enabled) {
 600     verify_result->cert_status |= CERT_STATUS_REV_CHECKING_ENABLED;
 601   } else {
 602     chain_flags |= CERT_CHAIN_REVOCATION_CHECK_CACHE_ONLY;
 603   }
 604
 605   // For non-test scenarios, use the default HCERTCHAINENGINE, NULL, which
 606   // corresponds to HCCE_CURRENT_USER and is is initialized as needed by
 607   // crypt32. However, when testing, it is necessary to create a new
 608   // HCERTCHAINENGINE and use that instead. This is because each
 609   // HCERTCHAINENGINE maintains a cache of information about certificates
 610   // encountered, and each test run may modify the trust status of a
 611   // certificate.
 612   ScopedHCERTCHAINENGINE chain_engine(NULL);
 613   if (TestRootCerts::HasInstance())
 614     chain_engine.reset(TestRootCerts::GetInstance()->GetChainEngine());
 615
 616   ScopedPCCERT_CONTEXT cert_list(cert->CreateOSCertChainForCert());
 617   PCCERT_CHAIN_CONTEXT chain_context;
 618   // IE passes a non-NULL pTime argument that specifies the current system
 619   // time.  IE passes CERT_CHAIN_REVOCATION_CHECK_CHAIN_EXCLUDE_ROOT as the
 620   // chain_flags argument.
 621   if (!CertGetCertificateChain(
 622            chain_engine,
 623            cert_list.get(),
 624            NULL,  // current system time
 625            cert_list->hCertStore,
 626            &chain_para,
 627            chain_flags,
 628            NULL,  // reserved
 629            &chain_context)) {
 630     verify_result->cert_status |= CERT_STATUS_INVALID;
 631     return MapSecurityError(GetLastError());
 632   }
 633
 634   CRLSetResult crl_set_result = kCRLSetUnknown;
 635   if (crl_set)
 636     crl_set_result = CheckRevocationWithCRLSet(chain_context, crl_set);
 637
 638   if (crl_set_result == kCRLSetRevoked) {
 639     verify_result->cert_status |= CERT_STATUS_REVOKED;
 640   } else if (crl_set_result == kCRLSetUnknown &&
 641              (flags & CertVerifier::VERIFY_REV_CHECKING_ENABLED_EV_ONLY) &&
 642              !rev_checking_enabled &&
 643              ev_policy_oid != NULL) {
 644     // We don't have fresh information about this chain from the CRLSet and
 645     // it's probably an EV certificate. Retry with online revocation checking.
 646     rev_checking_enabled = true;
 647     chain_flags &= ~CERT_CHAIN_REVOCATION_CHECK_CACHE_ONLY;
 648     verify_result->cert_status |= CERT_STATUS_REV_CHECKING_ENABLED;
 649
 650     if (!CertGetCertificateChain(
 651              chain_engine,
 652              cert_list.get(),
 653              NULL,  // current system time
 654              cert_list->hCertStore,
 655              &chain_para,
 656              chain_flags,
 657              NULL,  // reserved
 658              &chain_context)) {
 659       verify_result->cert_status |= CERT_STATUS_INVALID;
 660       return MapSecurityError(GetLastError());
 661     }
 662   }
 663
 664   if (chain_context->TrustStatus.dwErrorStatus &
 665       CERT_TRUST_IS_NOT_VALID_FOR_USAGE) {
 666     ev_policy_oid = NULL;
 667     chain_para.RequestedIssuancePolicy.Usage.cUsageIdentifier = 0;
 668     chain_para.RequestedIssuancePolicy.Usage.rgpszUsageIdentifier = NULL;
 669     CertFreeCertificateChain(chain_context);
 670     if (!CertGetCertificateChain(
 671              chain_engine,
 672              cert_list.get(),
 673              NULL,  // current system time
 674              cert_list->hCertStore,
 675              &chain_para,
 676              chain_flags,
 677              NULL,  // reserved
 678              &chain_context)) {
 679       verify_result->cert_status |= CERT_STATUS_INVALID;
 680       return MapSecurityError(GetLastError());
 681     }
 682   }
 683
 684   CertVerifyResult temp_verify_result = *verify_result;
 685   GetCertChainInfo(chain_context, verify_result);
 686   if (!verify_result->is_issued_by_known_root &&
 687       (flags & CertVerifier::VERIFY_REV_CHECKING_REQUIRED_LOCAL_ANCHORS)) {
 688     *verify_result = temp_verify_result;
 689
 690     rev_checking_enabled = true;
 691     verify_result->cert_status |= CERT_STATUS_REV_CHECKING_ENABLED;
 692     chain_flags &= ~CERT_CHAIN_REVOCATION_CHECK_CACHE_ONLY;
 693
 694     CertFreeCertificateChain(chain_context);
 695     if (!CertGetCertificateChain(
 696              chain_engine,
 697              cert_list.get(),
 698              NULL,  // current system time
 699              cert_list->hCertStore,
 700              &chain_para,
 701              chain_flags,
 702              NULL,  // reserved
 703              &chain_context)) {
 704       verify_result->cert_status |= CERT_STATUS_INVALID;
 705       return MapSecurityError(GetLastError());
 706     }
 707     GetCertChainInfo(chain_context, verify_result);
 708
 709     if (chain_context->TrustStatus.dwErrorStatus &
 710         CERT_TRUST_IS_OFFLINE_REVOCATION) {
 711       verify_result->cert_status |= CERT_STATUS_REVOKED;
 712     }
 713   }
 714
 715   ScopedPCCERT_CHAIN_CONTEXT scoped_chain_context(chain_context);
 716
 717   verify_result->cert_status |= MapCertChainErrorStatusToCertStatus(
 718       chain_context->TrustStatus.dwErrorStatus);
 719
 720   // Flag certificates that have a Subject common name with a NULL character.
 721   if (CertSubjectCommonNameHasNull(cert_handle))
 722     verify_result->cert_status |= CERT_STATUS_INVALID;
 723
 724   std::wstring wstr_hostname = ASCIIToWide(hostname);
 725
 726   SSL_EXTRA_CERT_CHAIN_POLICY_PARA extra_policy_para;
 727   memset(&extra_policy_para, 0, sizeof(extra_policy_para));
 728   extra_policy_para.cbSize = sizeof(extra_policy_para);
 729   extra_policy_para.dwAuthType = AUTHTYPE_SERVER;
 730   extra_policy_para.fdwChecks = 0;
 731   extra_policy_para.pwszServerName =
 732       const_cast<wchar_t*>(wstr_hostname.c_str());
 733
 734   CERT_CHAIN_POLICY_PARA policy_para;
 735   memset(&policy_para, 0, sizeof(policy_para));
 736   policy_para.cbSize = sizeof(policy_para);
 737   policy_para.dwFlags = 0;
 738   policy_para.pvExtraPolicyPara = &extra_policy_para;
 739
 740   CERT_CHAIN_POLICY_STATUS policy_status;
 741   memset(&policy_status, 0, sizeof(policy_status));
 742   policy_status.cbSize = sizeof(policy_status);
 743
 744   if (!CertVerifyCertificateChainPolicy(
 745            CERT_CHAIN_POLICY_SSL,
 746            chain_context,
 747            &policy_para,
 748            &policy_status)) {
 749     return MapSecurityError(GetLastError());
 750   }
 751
 752   if (policy_status.dwError) {
 753     verify_result->cert_status |= MapNetErrorToCertStatus(
 754         MapSecurityError(policy_status.dwError));
 755
 756     // CertVerifyCertificateChainPolicy reports only one error (in
 757     // policy_status.dwError) if the certificate has multiple errors.
 758     // CertGetCertificateChain doesn't report certificate name mismatch, so
 759     // CertVerifyCertificateChainPolicy is the only function that can report
 760     // certificate name mismatch.
 761     //
 762     // To prevent a potential certificate name mismatch from being hidden by
 763     // some other certificate error, if we get any other certificate error,
 764     // we call CertVerifyCertificateChainPolicy again, ignoring all other
 765     // certificate errors.  Both extra_policy_para.fdwChecks and
 766     // policy_para.dwFlags allow us to ignore certificate errors, so we set
 767     // them both.
 768     if (policy_status.dwError != CERT_E_CN_NO_MATCH) {
 769       const DWORD extra_ignore_flags =
 770           0x00000080 |  // SECURITY_FLAG_IGNORE_REVOCATION
 771           0x00000100 |  // SECURITY_FLAG_IGNORE_UNKNOWN_CA
 772           0x00002000 |  // SECURITY_FLAG_IGNORE_CERT_DATE_INVALID
 773           0x00000200;   // SECURITY_FLAG_IGNORE_WRONG_USAGE
 774       extra_policy_para.fdwChecks = extra_ignore_flags;
 775       const DWORD ignore_flags =
 776           CERT_CHAIN_POLICY_IGNORE_ALL_NOT_TIME_VALID_FLAGS |
 777           CERT_CHAIN_POLICY_IGNORE_INVALID_BASIC_CONSTRAINTS_FLAG |
 778           CERT_CHAIN_POLICY_ALLOW_UNKNOWN_CA_FLAG |
 779           CERT_CHAIN_POLICY_IGNORE_WRONG_USAGE_FLAG |
 780           CERT_CHAIN_POLICY_IGNORE_INVALID_NAME_FLAG |
 781           CERT_CHAIN_POLICY_IGNORE_INVALID_POLICY_FLAG |
 782           CERT_CHAIN_POLICY_IGNORE_ALL_REV_UNKNOWN_FLAGS |
 783           CERT_CHAIN_POLICY_ALLOW_TESTROOT_FLAG |
 784           CERT_CHAIN_POLICY_TRUST_TESTROOT_FLAG |
 785           CERT_CHAIN_POLICY_IGNORE_NOT_SUPPORTED_CRITICAL_EXT_FLAG |
 786           CERT_CHAIN_POLICY_IGNORE_PEER_TRUST_FLAG;
 787       policy_para.dwFlags = ignore_flags;
 788       if (!CertVerifyCertificateChainPolicy(
 789                CERT_CHAIN_POLICY_SSL,
 790                chain_context,
 791                &policy_para,
 792                &policy_status)) {
 793         return MapSecurityError(GetLastError());
 794       }
 795       if (policy_status.dwError) {
 796         verify_result->cert_status |= MapNetErrorToCertStatus(
 797             MapSecurityError(policy_status.dwError));
 798       }
 799     }
 800   }
 801
 802   // TODO(wtc): Suppress CERT_STATUS_NO_REVOCATION_MECHANISM for now to be
 803   // compatible with WinHTTP, which doesn't report this error (bug 3004).
 804   verify_result->cert_status &= ~CERT_STATUS_NO_REVOCATION_MECHANISM;
 805
 806   if (!rev_checking_enabled) {
 807     // If we didn't do online revocation checking then Windows will report
 808     // CERT_UNABLE_TO_CHECK_REVOCATION unless it had cached OCSP or CRL
 809     // information for every certificate. We only want to put up revoked
 810     // statuses from the offline checks so we squash this error.
 811     verify_result->cert_status &= ~CERT_STATUS_UNABLE_TO_CHECK_REVOCATION;
 812   }
 813
 814   AppendPublicKeyHashes(chain_context, &verify_result->public_key_hashes);
 815   verify_result->is_issued_by_known_root = IsIssuedByKnownRoot(chain_context);
 816
 817   if (IsCertStatusError(verify_result->cert_status))
 818     return MapCertStatusToNetError(verify_result->cert_status);
 819
 820   if (ev_policy_oid &&
 821       CheckEV(chain_context, rev_checking_enabled, ev_policy_oid)) {
 822     verify_result->cert_status |= CERT_STATUS_IS_EV;
 823   }
 824   return OK;
 825 }
 826
 827 }  // namespace net