cast_crl.cc | Explore in Territory

// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40285824): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif

#include "components/media_router/common/providers/cast/certificate/cast_crl.h"

#include <unordered_map>
#include <unordered_set>

#include <memory>

#include "base/build_time.h"
#include "base/containers/span.h"
#include "base/logging.h"
#include "base/memory/singleton.h"
#include "base/time/time.h"
#include "components/media_router/common/providers/cast/certificate/cast_fallback_crl.h"
#include "crypto/sha2.h"
#include "net/cert/time_conversions.h"
#include "net/cert/x509_util.h"
#include "third_party/boringssl/src/include/openssl/bytestring.h"
#include "third_party/boringssl/src/include/openssl/digest.h"
#include "third_party/boringssl/src/include/openssl/evp.h"
#include "third_party/boringssl/src/pki/cert_errors.h"
#include "third_party/boringssl/src/pki/input.h"
#include "third_party/boringssl/src/pki/parse_certificate.h"
#include "third_party/boringssl/src/pki/parse_values.h"
#include "third_party/boringssl/src/pki/parsed_certificate.h"
#include "third_party/boringssl/src/pki/path_builder.h"
#include "third_party/boringssl/src/pki/simple_path_builder_delegate.h"
#include "third_party/boringssl/src/pki/trust_store_in_memory.h"
#include "third_party/boringssl/src/pki/verify_certificate_chain.h"
#include "third_party/openscreen/src/cast/common/certificate/proto/revocation.pb.h"

namespace cast_certificate {

Crl;
CrlBundle;
TbsCrl;

namespace {

#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
// During fuzz testing, we won't have valid hashes for certificate revocation,
// so we use the empty string as a placeholder where a hash code is needed in
// production.  This allows us to test the revocation logic without needing the
// fuzzing engine to produce a valid hash code.
constexpr char kFakeHashForFuzzing[] = "fake_hash_code";
#endif

enum CrlVersion { … };

// -------------------------------------------------------------------------
// Cast CRL trust anchors.
// -------------------------------------------------------------------------

// There is one trusted root for Cast CRL certificate chains:
//
//   (1) CN=Cast CRL Root CA    (kCastCRLRootCaDer)
//
// These constants are defined by the file included next:

#include "components/media_router/common/providers/cast/certificate/cast_crl_root_ca_cert_der-inc.h"

// When the fallback Cast CRL is used, ignore the back-up Cast CRL’s validity
// range. Instead, use the Build Time as the not_before date and Build Time + 20
// weeks as the not_after time. This is a constant as 20 weeks in seconds
constexpr static int kFallbackCrlValidityInSeconds = …;

// Singleton for the Cast CRL trust store.
class CastCRLTrustStore { … };

// Converts a uint64_t unix timestamp to net::der::GeneralizedTime.
bool ConvertTimeSeconds(uint64_t seconds,
                        bssl::der::GeneralizedTime* generalized_time) { … }

// Verifies the CRL is signed by a trusted CRL authority at the time the CRL
// was issued. Verifies the signature of |tbs_crl| is valid based on the
// certificate and signature in |crl|. The validity of |tbs_crl| is verified
// at |time|. The validity period of the CRL is adjusted to be the earliest
// of the issuer certificate chain's expiration and the CRL's expiration and
// the result is stored in |overall_not_after|.
// |is_fallback_crl| states whether a fallback CRL is used. When true,
// ignore the validity range of the fallback CRL's issuer certificate.
bool VerifyCRL(const Crl& crl,
               const TbsCrl& tbs_crl,
               const base::Time& time,
               bssl::TrustStore* trust_store,
               bssl::der::GeneralizedTime* overall_not_after,
               bool is_fallback_crl) { … }

class CastCRLImpl : public CastCRL { … };

CastCRLImpl::CastCRLImpl(const TbsCrl& tbs_crl,
                         const bssl::der::GeneralizedTime& overall_not_after) { … }

CastCRLImpl::~CastCRLImpl() { … }

// Verifies the revocation status of the certificate chain, at the specified
// time.
bool CastCRLImpl::CheckRevocation(
    const bssl::ParsedCertificateList& trusted_chain,
    const base::Time& time) const { … }

}  // namespace

std::unique_ptr<CastCRL> ParseAndVerifyCRL(const std::string& crl_proto,
                                           const base::Time& time,
                                           const bool is_fallback_crl) { … }

std::unique_ptr<CastCRL> ParseAndVerifyCRLUsingCustomTrustStore(
    const std::string& crl_proto,
    const base::Time& time,
    bssl::TrustStore* trust_store,
    const bool is_fallback_crl) { … }

std::unique_ptr<CastCRL> ParseAndVerifyFallbackCRLUsingCustomTrustStore(
    const base::Time& time,
    bssl::TrustStore* trust_store) { … }

}  // namespace cast_certificate
chromium/components/media_router/common/providers/cast/certificate/cast_crl.cc
