| // Copyright 2015 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. |
| |
| #include "components/rappor/rappor_prefs.h" |
| |
| #include "base/base64.h" |
| #include "base/metrics/histogram_macros.h" |
| #include "base/prefs/pref_registry_simple.h" |
| #include "base/prefs/pref_service.h" |
| #include "base/rand_util.h" |
| #include "components/metrics/daily_event.h" |
| #include "components/rappor/byte_vector_utils.h" |
| #include "components/rappor/rappor_parameters.h" |
| #include "components/rappor/rappor_pref_names.h" |
| |
| namespace rappor { |
| |
| namespace internal { |
| |
| const char kLoadCohortHistogramName[] = "Rappor.LoadCohortResult"; |
| const char kLoadSecretHistogramName[] = "Rappor.LoadSecretResult"; |
| |
| namespace { |
| |
| void RecordLoadCohortResult(LoadResult reason) { |
| UMA_HISTOGRAM_ENUMERATION(kLoadCohortHistogramName, |
| reason, |
| NUM_LOAD_RESULTS); |
| } |
| |
| void RecordLoadSecretResult(LoadResult reason) { |
| UMA_HISTOGRAM_ENUMERATION(kLoadSecretHistogramName, |
| reason, |
| NUM_LOAD_RESULTS); |
| } |
| |
| } // namespace |
| |
| void RegisterPrefs(PrefRegistrySimple* registry) { |
| registry->RegisterStringPref(prefs::kRapporSecret, std::string()); |
| registry->RegisterIntegerPref(prefs::kRapporCohortDeprecated, -1); |
| registry->RegisterIntegerPref(prefs::kRapporCohortSeed, -1); |
| metrics::DailyEvent::RegisterPref(registry, prefs::kRapporLastDailySample); |
| } |
| |
| int32_t LoadCohort(PrefService* pref_service) { |
| // Ignore and delete old cohort parameter. |
| pref_service->ClearPref(prefs::kRapporCohortDeprecated); |
| |
| int32_t cohort = pref_service->GetInteger(prefs::kRapporCohortSeed); |
| // If the user is already assigned to a valid cohort, we're done. |
| if (cohort >= 0 && cohort < RapporParameters::kMaxCohorts) { |
| RecordLoadCohortResult(LOAD_SUCCESS); |
| DVLOG(2) << "Rappor cohort loaded."; |
| return cohort; |
| } |
| |
| // This is the first time the client has started the service (or their |
| // preferences were corrupted). Randomly assign them to a cohort. |
| RecordLoadCohortResult(cohort == -1 ? LOAD_EMPTY_VALUE : LOAD_CORRUPT_VALUE); |
| cohort = base::RandGenerator(RapporParameters::kMaxCohorts); |
| DVLOG(2) << "Selected a new Rappor cohort: " << cohort; |
| pref_service->SetInteger(prefs::kRapporCohortSeed, cohort); |
| return cohort; |
| } |
| |
| std::string LoadSecret(PrefService* pref_service) { |
| std::string secret; |
| std::string secret_base64 = pref_service->GetString(prefs::kRapporSecret); |
| if (!secret_base64.empty()) { |
| bool decoded = base::Base64Decode(secret_base64, &secret); |
| if (decoded && |
| secret.size() == HmacByteVectorGenerator::kEntropyInputSize) { |
| DVLOG(2) << "Rappor secret loaded."; |
| RecordLoadSecretResult(LOAD_SUCCESS); |
| return secret; |
| } |
| // If the preference fails to decode, or is the wrong size, it must be |
| // corrupt, so continue as though it didn't exist yet and generate a new |
| // one. |
| DVLOG(2) << "Corrupt Rappor secret found."; |
| RecordLoadSecretResult(LOAD_CORRUPT_VALUE); |
| } else { |
| DVLOG(2) << "No Rappor secret found."; |
| RecordLoadSecretResult(LOAD_EMPTY_VALUE); |
| } |
| |
| DVLOG(2) << "Generated a new Rappor secret."; |
| secret = HmacByteVectorGenerator::GenerateEntropyInput(); |
| base::Base64Encode(secret, &secret_base64); |
| pref_service->SetString(prefs::kRapporSecret, secret_base64); |
| return secret; |
| } |
| |
| } // namespace internal |
| |
| } // namespace rappor |