gecko-dev/security/certverifier/CertVerifier.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef CertVerifier_h
#define CertVerifier_h

#include "BRNameMatchingPolicy.h"
#include "CTPolicyEnforcer.h"
#include "CTVerifyResult.h"
#include "OCSPCache.h"
#include "RootCertificateTelemetryUtils.h"
#include "ScopedNSSTypes.h"
#include "mozilla/Telemetry.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/UniquePtr.h"
#include "nsString.h"
#include "mozpkix/pkixtypes.h"

#if defined(_MSC_VER)
#pragma warning(push)
// Silence "RootingAPI.h(718): warning C4324: 'js::DispatchWrapper<T>':
// structure was padded due to alignment specifier with [ T=void * ]"
#pragma warning(disable : 4324)
#endif /* defined(_MSC_VER) */
#include "mozilla/BasePrincipal.h"
#if defined(_MSC_VER)
#pragma warning(pop) /* popping the pragma in this file */
#endif               /* defined(_MSC_VER) */

namespace mozilla {
namespace ct {

// Including the headers of the classes below would bring along all of their
// dependent headers and force us to export them in moz.build.
// Just forward-declare the classes here instead.
class MultiLogCTVerifier;
class CTDiversityPolicy;

}  // namespace ct
}  // namespace mozilla

namespace mozilla {
namespace psm {

typedef mozilla::pkix::Result Result;

// These values correspond to the CERT_CHAIN_KEY_SIZE_STATUS telemetry.
enum class KeySizeStatus {
  NeverChecked = 0,
  LargeMinimumSucceeded = 1,
  CompatibilityRisk = 2,
  AlreadyBad = 3,
};

// These values correspond to the CERT_CHAIN_SHA1_POLICY_STATUS telemetry.
enum class SHA1ModeResult {
  NeverChecked = 0,
  SucceededWithoutSHA1 = 1,
  SucceededWithImportedRoot = 2,
  SucceededWithImportedRootOrSHA1Before2016 = 3,
  SucceededWithSHA1 = 4,
  Failed = 5,
};

// Whether or not we are enforcing one of our CA distrust policies. For context,
// see Bug 1437754 and Bug 1409257.
enum DistrustedCAPolicy : uint32_t {
  Permit = 0b0000,
  DistrustSymantecRoots = 0b0001,
  DistrustSymantecRootsRegardlessOfDate = 0b0010,
};

// Bitmask by nsNSSComponent to check for wholly-invalid values; be sure to
// update this to account for new entries in DistrustedCAPolicy.
const uint32_t DistrustedCAPolicyMaxAllowedValueMask = 0b0011;

enum class NetscapeStepUpPolicy : uint32_t;

class PinningTelemetryInfo {
 public:
  PinningTelemetryInfo()
      : certPinningResultBucket(0), rootBucket(ROOT_CERTIFICATE_UNKNOWN) {
    Reset();
  }

  // Should we accumulate pinning telemetry for the result?
  bool accumulateResult;
  Maybe<Telemetry::HistogramID> certPinningResultHistogram;
  int32_t certPinningResultBucket;
  // Should we accumulate telemetry for the root?
  bool accumulateForRoot;
  int32_t rootBucket;

  void Reset() {
    accumulateForRoot = false;
    accumulateResult = false;
  }
};

class CertificateTransparencyInfo {
 public:
  CertificateTransparencyInfo()
      : enabled(false),
        policyCompliance(mozilla::ct::CTPolicyCompliance::Unknown) {
    Reset();
  }

  // Was CT enabled?
  bool enabled;
  // Verification result of the processed SCTs.
  mozilla::ct::CTVerifyResult verifyResult;
  // Connection compliance to the CT Policy.
  mozilla::ct::CTPolicyCompliance policyCompliance;

  void Reset();
};

class NSSCertDBTrustDomain;

class CertVerifier {
 public:
  typedef unsigned int Flags;
  // XXX: FLAG_LOCAL_ONLY is ignored in the classic verification case
  static const Flags FLAG_LOCAL_ONLY;
  // Don't perform fallback DV validation on EV validation failure.
  static const Flags FLAG_MUST_BE_EV;
  // TLS feature request_status should be ignored
  static const Flags FLAG_TLS_IGNORE_STATUS_REQUEST;

  // These values correspond to the SSL_OCSP_STAPLING telemetry.
  enum OCSPStaplingStatus {
    OCSP_STAPLING_NEVER_CHECKED = 0,
    OCSP_STAPLING_GOOD = 1,
    OCSP_STAPLING_NONE = 2,
    OCSP_STAPLING_EXPIRED = 3,
    OCSP_STAPLING_INVALID = 4,
  };

  // *evOidPolicy == SEC_OID_UNKNOWN means the cert is NOT EV
  // Only one usage per verification is supported.
  mozilla::pkix::Result VerifyCert(
      CERTCertificate* cert, SECCertificateUsage usage,
      mozilla::pkix::Time time, void* pinArg, const char* hostname,
      /*out*/ UniqueCERTCertList& builtChain, Flags flags = 0,
      /*optional in*/ const SECItem* stapledOCSPResponse = nullptr,
      /*optional in*/ const SECItem* sctsFromTLS = nullptr,
      /*optional in*/ const OriginAttributes& originAttributes =
          OriginAttributes(),
      /*optional out*/ SECOidTag* evOidPolicy = nullptr,
      /*optional out*/ OCSPStaplingStatus* ocspStaplingStatus = nullptr,
      /*optional out*/ KeySizeStatus* keySizeStatus = nullptr,
      /*optional out*/ SHA1ModeResult* sha1ModeResult = nullptr,
      /*optional out*/ PinningTelemetryInfo* pinningTelemetryInfo = nullptr,
      /*optional out*/ CertificateTransparencyInfo* ctInfo = nullptr);

  mozilla::pkix::Result VerifySSLServerCert(
      const UniqueCERTCertificate& peerCert,
      /*optional*/ const SECItem* stapledOCSPResponse,
      /*optional*/ const SECItem* sctsFromTLS, mozilla::pkix::Time time,
      /*optional*/ void* pinarg, const nsACString& hostname,
      /*out*/ UniqueCERTCertList& builtChain,
      /*optional*/ bool saveIntermediatesInPermanentDatabase = false,
      /*optional*/ Flags flags = 0,
      /*optional*/ const OriginAttributes& originAttributes =
          OriginAttributes(),
      /*optional out*/ SECOidTag* evOidPolicy = nullptr,
      /*optional out*/ OCSPStaplingStatus* ocspStaplingStatus = nullptr,
      /*optional out*/ KeySizeStatus* keySizeStatus = nullptr,
      /*optional out*/ SHA1ModeResult* sha1ModeResult = nullptr,
      /*optional out*/ PinningTelemetryInfo* pinningTelemetryInfo = nullptr,
      /*optional out*/ CertificateTransparencyInfo* ctInfo = nullptr);

  enum PinningMode {
    pinningDisabled = 0,
    pinningAllowUserCAMITM = 1,
    pinningStrict = 2,
    pinningEnforceTestMode = 3
  };

  enum class SHA1Mode {
    Allowed = 0,
    Forbidden = 1,
    // There used to be a policy that only allowed SHA1 for certificates issued
    // before 2016. This is no longer available. If a user has selected this
    // policy in about:config, it now maps to Forbidden.
    UsedToBeBefore2016ButNowIsForbidden = 2,
    ImportedRoot = 3,
    ImportedRootOrBefore2016 = 4,
  };

  enum OcspDownloadConfig { ocspOff = 0, ocspOn = 1, ocspEVOnly = 2 };
  enum OcspStrictConfig { ocspRelaxed = 0, ocspStrict };

  enum class CertificateTransparencyMode {
    Disabled = 0,
    TelemetryOnly = 1,
  };

  CertVerifier(OcspDownloadConfig odc, OcspStrictConfig osc,
               mozilla::TimeDuration ocspTimeoutSoft,
               mozilla::TimeDuration ocspTimeoutHard,
               uint32_t certShortLifetimeInDays, PinningMode pinningMode,
               SHA1Mode sha1Mode, BRNameMatchingPolicy::Mode nameMatchingMode,
               NetscapeStepUpPolicy netscapeStepUpPolicy,
               CertificateTransparencyMode ctMode,
               DistrustedCAPolicy distrustedCAPolicy);
  ~CertVerifier();

  void ClearOCSPCache() { mOCSPCache.Clear(); }

  const OcspDownloadConfig mOCSPDownloadConfig;
  const bool mOCSPStrict;
  const mozilla::TimeDuration mOCSPTimeoutSoft;
  const mozilla::TimeDuration mOCSPTimeoutHard;
  const uint32_t mCertShortLifetimeInDays;
  const PinningMode mPinningMode;
  const SHA1Mode mSHA1Mode;
  const BRNameMatchingPolicy::Mode mNameMatchingMode;
  const NetscapeStepUpPolicy mNetscapeStepUpPolicy;
  const CertificateTransparencyMode mCTMode;
  const DistrustedCAPolicy mDistrustedCAPolicy;

 private:
  OCSPCache mOCSPCache;

  // We only have a forward declarations of these classes (see above)
  // so we must allocate dynamically.
  UniquePtr<mozilla::ct::MultiLogCTVerifier> mCTVerifier;
  UniquePtr<mozilla::ct::CTDiversityPolicy> mCTDiversityPolicy;

  void LoadKnownCTLogs();
  mozilla::pkix::Result VerifyCertificateTransparencyPolicy(
      NSSCertDBTrustDomain& trustDomain, const UniqueCERTCertList& builtChain,
      mozilla::pkix::Input sctsFromTLS, mozilla::pkix::Time time,
      /*optional out*/ CertificateTransparencyInfo* ctInfo);

  // Returns true if the configured SHA1 mode is more restrictive than the given
  // mode. SHA1Mode::Forbidden is more restrictive than any other mode except
  // Forbidden. Next is ImportedRoot, then ImportedRootOrBefore2016, then
  // Allowed. (A mode is never more restrictive than itself.)
  bool SHA1ModeMoreRestrictiveThanGivenMode(SHA1Mode mode);
};

mozilla::pkix::Result IsCertBuiltInRoot(CERTCertificate* cert, bool& result);
mozilla::pkix::Result CertListContainsExpectedKeys(
    const CERTCertList* certList, const char* hostname,
    mozilla::pkix::Time time, CertVerifier::PinningMode pinningMode);

}  // namespace psm
}  // namespace mozilla

#endif  // CertVerifier_h