hash_realtime_utils.h | Explore in Territory

// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_SAFE_BROWSING_CORE_COMMON_HASHPREFIX_REALTIME_HASH_REALTIME_UTILS_H_
#define COMPONENTS_SAFE_BROWSING_CORE_COMMON_HASHPREFIX_REALTIME_HASH_REALTIME_UTILS_H_

#include <optional>

#include "components/safe_browsing/core/common/proto/safebrowsingv5.pb.h"
#include "url/gurl.h"

class PrefService;

namespace variations {
class VariationsService;
}

// These are utils for hash-prefix real-time lookups.
namespace safe_browsing::hash_realtime_utils {
constexpr size_t kHashPrefixLength = …;  // bytes
constexpr size_t kFullHashLength = …;   // bytes

// Specifies which hash-prefix real-time lookup should be used.
enum class HashRealTimeSelection { … };

// Used only for tests. This is useful so that more than just
// GOOGLE_CHROME_BRANDING bots are capable of testing code that only runs when
// |IsHashRealTimeLookupEligibleInSession| returns true. To allow pretending
// that there is Google Chrome branding on unbranded builds, create an object
// of this type and keep it in scope for as long as the override should exist.
// The constructor will set the override, and the destructor will clear it. If
// necessary, the override can be cleared by calling |StopApplyingBranding|.
class GoogleChromeBrandingPretenderForTesting { … };

struct HashRealTimeSelectionConfiguringPrefs { … };

// Returns whether the |url| is eligible for hash-prefix real-time checks.
bool CanCheckUrl(const GURL& url);

// Returns whether the full hash detail is relevant for hash-prefix real-time
// lookups.
bool IsHashDetailRelevant(const V5::FullHash::FullHashDetail& detail);

// Returns the 4-byte prefix of the requested 32-byte full hash.
std::string GetHashPrefix(const std::string& full_hash);

// Specifies whether hash-prefix real-time lookups are possible for the browser
// session. For cases when the user's location should not influence the logic,
// This should be used over |IsHashRealTimeLookupEligibleInSessionAndLocation|,
// for example for determining the settings UI description of Standard Safe
// Browsing.
bool IsHashRealTimeLookupEligibleInSession();

// Based on the user's browser session and location, specifies whether
// hash-prefix real-time lookups are eligible. Outside of tests,
// |latest_country| should be determined with the helper function
// |hash_realtime_utils::GetCountryCode|. If it's passed in as std::nullopt,
// the location is considered eligible.
bool IsHashRealTimeLookupEligibleInSessionAndLocation(
    std::optional<std::string> latest_country);

// Returns the latest country. If |variations_service| is null, returns
// std::nullopt. This should be used only as a helper to determine the country
// code to pass into |IsHashRealTimeLookupEligibleInSessionAndLocation| and
// |DetermineHashRealTimeSelection|. This is separated out into a function
// to simplify tests.
std::optional<std::string> GetCountryCode(
    variations::VariationsService* variations_service);

// Based on the user's settings and session, determines which hash-prefix
// real-time lookup should be used, if any. If |log_usage_histograms| is true,
// this will log metrics related to whether hash real-time lookups were
// available or why not. Outside of tests, |latest_country| should be
// determined with the helper function |hash_realtime_utils::GetCountryCode|.
// If it's passed in as std::nullopt, the location is considered eligible.
HashRealTimeSelection DetermineHashRealTimeSelection(
    bool is_off_the_record,
    PrefService* prefs,
    std::optional<std::string> latest_country,
    bool log_usage_histograms = false);

// A helper for consumers that want to recompute
// |DetermineHashRealTimeSelection| when there are pref changes. This returns
// all prefs that modify the outcome of that method.
HashRealTimeSelectionConfiguringPrefs
GetHashRealTimeSelectionConfiguringPrefs();

}  // namespace safe_browsing::hash_realtime_utils

#endif  // COMPONENTS_SAFE_BROWSING_CORE_COMMON_HASHPREFIX_REALTIME_HASH_REALTIME_UTILS_H_
chromium/components/safe_browsing/core/common/hashprefix_realtime/hash_realtime_utils.h
