text: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #ifndef NET_CERT_MULTI_THREADED_CERT_VERIFIER_H_
  #define NET_CERT_MULTI_THREADED_CERT_VERIFIER_H_
  
  #include <map>
  #include <string>
  #include <vector>
  
  #include "base/basictypes.h"
  #include "base/gtest_prod_util.h"
  #include "base/memory/ref_counted.h"
  #include "base/threading/non_thread_safe.h"
  #include "net/base/completion_callback.h"
  #include "net/base/expiring_cache.h"
  #include "net/base/hash_value.h"
  #include "net/base/net_export.h"
  #include "net/cert/cert_database.h"
  #include "net/cert/cert_verifier.h"
  #include "net/cert/cert_verify_result.h"
  #include "net/cert/x509_cert_types.h"
  
  namespace net {
  
  class CertTrustAnchorProvider;
  class CertVerifierJob;
  class CertVerifierRequest;
  class CertVerifierWorker;
  class CertVerifyProc;
  
  // MultiThreadedCertVerifier is a CertVerifier implementation that runs
  // synchronous CertVerifier implementations on worker threads.
  class NET_EXPORT_PRIVATE MultiThreadedCertVerifier
      : public CertVerifier,
        NON_EXPORTED_BASE(public base::NonThreadSafe),
        public CertDatabase::Observer {
   public:
    explicit MultiThreadedCertVerifier(CertVerifyProc* verify_proc);
  
    // When the verifier is destroyed, all certificate verifications requests are
    // canceled, and their completion callbacks will not be called.
    virtual ~MultiThreadedCertVerifier();
  
    // Configures a source of additional certificates that should be treated as
    // trust anchors during verification, provided that the underlying
    // CertVerifyProc supports additional trust beyond the default implementation.
    // The CertTrustAnchorProvider will only be accessed on the same
    // thread that Verify() is called on; that is, it will not be
    // accessed from worker threads.
    // It must outlive the MultiThreadedCertVerifier.
    void SetCertTrustAnchorProvider(
        CertTrustAnchorProvider* trust_anchor_provider);
  
    // CertVerifier implementation
    virtual int Verify(X509Certificate* cert,
                       const std::string& hostname,
                       int flags,
                       CRLSet* crl_set,
                       CertVerifyResult* verify_result,
                       const CompletionCallback& callback,
                       CertVerifier::RequestHandle* out_req,
                       const BoundNetLog& net_log) OVERRIDE;
  
    virtual void CancelRequest(CertVerifier::RequestHandle req) OVERRIDE;
  
   private:
    friend class CertVerifierWorker;  // Calls HandleResult.
    friend class CertVerifierRequest;
    friend class CertVerifierJob;
    friend class MultiThreadedCertVerifierTest;
    FRIEND_TEST_ALL_PREFIXES(MultiThreadedCertVerifierTest, CacheHit);
    FRIEND_TEST_ALL_PREFIXES(MultiThreadedCertVerifierTest, DifferentCACerts);
    FRIEND_TEST_ALL_PREFIXES(MultiThreadedCertVerifierTest, InflightJoin);
    FRIEND_TEST_ALL_PREFIXES(MultiThreadedCertVerifierTest, CancelRequest);
    FRIEND_TEST_ALL_PREFIXES(MultiThreadedCertVerifierTest,
                             RequestParamsComparators);
    FRIEND_TEST_ALL_PREFIXES(MultiThreadedCertVerifierTest,
                             CertTrustAnchorProvider);
  
    // Input parameters of a certificate verification request.
    struct NET_EXPORT_PRIVATE RequestParams {
      RequestParams(const SHA1HashValue& cert_fingerprint_arg,
                    const SHA1HashValue& ca_fingerprint_arg,
                    const std::string& hostname_arg,
                    int flags_arg,
                    const CertificateList& additional_trust_anchors);
      ~RequestParams();
  
      bool operator<(const RequestParams& other) const;
  
      std::string hostname;
      int flags;
      std::vector<SHA1HashValue> hash_values;
    };
  
    // CachedResult contains the result of a certificate verification.
    struct NET_EXPORT_PRIVATE CachedResult {
      CachedResult();
      ~CachedResult();
  
      int error;  // The return value of CertVerifier::Verify.
      CertVerifyResult result;  // The output of CertVerifier::Verify.
    };
  
    // Rather than having a single validity point along a monotonically increasing
    // timeline, certificate verification is based on falling within a range of
    // the certificate's NotBefore and NotAfter and based on what the current
    // system clock says (which may advance forwards or backwards as users correct
    // clock skew). CacheValidityPeriod and CacheExpirationFunctor are helpers to
    // ensure that expiration is measured both by the 'general' case (now + cache
    // TTL) and by whether or not significant enough clock skew was introduced
    // since the last verification.
    struct CacheValidityPeriod {
      explicit CacheValidityPeriod(const base::Time& now);
      CacheValidityPeriod(const base::Time& now, const base::Time& expiration);
  
      base::Time verification_time;
      base::Time expiration_time;
    };
  
    struct CacheExpirationFunctor {
      // Returns true iff |now| is within the validity period of |expiration|.
      bool operator()(const CacheValidityPeriod& now,
                      const CacheValidityPeriod& expiration) const;
    };
  
    typedef ExpiringCache<RequestParams, CachedResult, CacheValidityPeriod,
                          CacheExpirationFunctor> CertVerifierCache;
  
    void HandleResult(X509Certificate* cert,
                      const std::string& hostname,
                      int flags,
                      const CertificateList& additional_trust_anchors,
                      int error,
                      const CertVerifyResult& verify_result);
  
    // CertDatabase::Observer methods:
    virtual void OnCACertChanged(const X509Certificate* cert) OVERRIDE;
  
    // For unit testing.
    void ClearCache() { cache_.Clear(); }
    size_t GetCacheSize() const { return cache_.size(); }
    uint64 cache_hits() const { return cache_hits_; }
    uint64 requests() const { return requests_; }
    uint64 inflight_joins() const { return inflight_joins_; }
  
    // cache_ maps from a request to a cached result.
    CertVerifierCache cache_;
  
    // inflight_ maps from a request to an active verification which is taking
    // place.
    std::map<RequestParams, CertVerifierJob*> inflight_;
  
    // A non-owning pointer to the first job for histogramming.
    CertVerifierJob* first_job_;
  
    uint64 requests_;
    uint64 cache_hits_;
    uint64 inflight_joins_;
  
    scoped_refptr<CertVerifyProc> verify_proc_;
  
    CertTrustAnchorProvider* trust_anchor_provider_;
  
    DISALLOW_COPY_AND_ASSIGN(MultiThreadedCertVerifier);
  };
  
  }  // namespace net
  
  #endif  // NET_CERT_MULTI_THREADED_CERT_VERIFIER_H_
  