1 // Copyright 2020 Google LLC
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 //
15 ///////////////////////////////////////////////////////////////////////////////
16 #include "tink/prf/prf_set_wrapper.h"
17
18 #include <cstdint>
19 #include <map>
20 #include <memory>
21 #include <string>
22 #include <utility>
23 #include <vector>
24
25 #include "absl/memory/memory.h"
26 #include "absl/status/status.h"
27 #include "absl/status/statusor.h"
28 #include "tink/internal/monitoring_util.h"
29 #include "tink/internal/registry_impl.h"
30 #include "tink/monitoring/monitoring.h"
31 #include "tink/prf/prf_set.h"
32 #include "tink/util/status.h"
33 #include "proto/tink.pb.h"
34
35 namespace crypto {
36 namespace tink {
37
38 using google::crypto::tink::OutputPrefixType;
39
40 namespace {
41
42 constexpr absl::string_view kPrimitive = "prf";
43 constexpr absl::string_view kComputeApi = "compute";
44
45 class MonitoredPrf : public Prf {
46 public:
MonitoredPrf(uint32_t key_id,const Prf * prf,MonitoringClient * monitoring_client)47 explicit MonitoredPrf(uint32_t key_id, const Prf* prf,
48 MonitoringClient* monitoring_client)
49 : key_id_(key_id), prf_(prf), monitoring_client_(monitoring_client) {}
50 ~MonitoredPrf() override = default;
51
52 MonitoredPrf(MonitoredPrf&& other) = default;
53 MonitoredPrf& operator=(MonitoredPrf&& other) = default;
54
55 MonitoredPrf(const MonitoredPrf&) = delete;
56 MonitoredPrf& operator=(const MonitoredPrf&) = delete;
57
Compute(absl::string_view input,size_t output_length) const58 util::StatusOr<std::string> Compute(absl::string_view input,
59 size_t output_length) const override {
60 util::StatusOr<std::string> result = prf_->Compute(input, output_length);
61 if (!result.ok()) {
62 if (monitoring_client_ != nullptr) {
63 monitoring_client_->LogFailure();
64 }
65 return result.status();
66 }
67
68 if (monitoring_client_ != nullptr) {
69 monitoring_client_->Log(key_id_, input.size());
70 }
71 return result.value();
72 }
73
74 private:
75 uint32_t key_id_;
76 const Prf* prf_;
77 MonitoringClient* monitoring_client_;
78 };
79
80 class PrfSetPrimitiveWrapper : public PrfSet {
81 public:
PrfSetPrimitiveWrapper(std::unique_ptr<PrimitiveSet<Prf>> prf_set,std::unique_ptr<MonitoringClient> monitoring_client=nullptr)82 explicit PrfSetPrimitiveWrapper(
83 std::unique_ptr<PrimitiveSet<Prf>> prf_set,
84 std::unique_ptr<MonitoringClient> monitoring_client = nullptr)
85 : prf_set_(std::move(prf_set)),
86 monitoring_client_(std::move(monitoring_client)) {
87 wrapped_prfs_.reserve(prf_set_->get_raw_primitives().value()->size());
88 for (const auto& prf : *prf_set_->get_raw_primitives().value()) {
89 std::unique_ptr<Prf> wrapped_prf = std::make_unique<MonitoredPrf>(
90 prf->get_key_id(), &prf->get_primitive(),
91 monitoring_client_.get());
92
93 prfs_.insert({prf->get_key_id(), wrapped_prf.get()});
94 wrapped_prfs_.push_back(std::move(wrapped_prf));
95 }
96 }
97
GetPrimaryId() const98 uint32_t GetPrimaryId() const override {
99 return prf_set_->get_primary()->get_key_id();
100 }
GetPrfs() const101 const std::map<uint32_t, Prf*>& GetPrfs() const override { return prfs_; }
102
103 ~PrfSetPrimitiveWrapper() override = default;
104
105 private:
106 std::unique_ptr<PrimitiveSet<Prf>> prf_set_;
107 std::unique_ptr<MonitoringClient> monitoring_client_;
108 std::vector<std::unique_ptr<Prf>> wrapped_prfs_;
109 std::map<uint32_t, Prf*> prfs_;
110 };
111
Validate(PrimitiveSet<Prf> * prf_set)112 util::Status Validate(PrimitiveSet<Prf>* prf_set) {
113 if (prf_set == nullptr) {
114 return util::Status(absl::StatusCode::kInternal,
115 "prf_set must be non-NULL");
116 }
117 if (prf_set->get_primary() == nullptr) {
118 return util::Status(absl::StatusCode::kInvalidArgument,
119 "prf_set has no primary");
120 }
121 for (auto prf : prf_set->get_all()) {
122 if (prf->get_output_prefix_type() != OutputPrefixType::RAW) {
123 return util::Status(absl::StatusCode::kInvalidArgument,
124 "PrfSet should only be used with prefix type RAW");
125 }
126 }
127 return util::OkStatus();
128 }
129
130 } // namespace
131
Wrap(std::unique_ptr<PrimitiveSet<Prf>> prf_set) const132 util::StatusOr<std::unique_ptr<PrfSet>> PrfSetWrapper::Wrap(
133 std::unique_ptr<PrimitiveSet<Prf>> prf_set) const {
134 util::Status status = Validate(prf_set.get());
135 if (!status.ok()) return status;
136
137 MonitoringClientFactory* const monitoring_factory =
138 internal::RegistryImpl::GlobalInstance().GetMonitoringClientFactory();
139 // Monitoring is not enabled. Create a wrapper without monitoring clients.
140 if (monitoring_factory == nullptr) {
141 return {absl::make_unique<PrfSetPrimitiveWrapper>(std::move(prf_set))};
142 }
143 util::StatusOr<MonitoringKeySetInfo> keyset_info =
144 internal::MonitoringKeySetInfoFromPrimitiveSet(*prf_set);
145 if (!keyset_info.ok()) {
146 return keyset_info.status();
147 }
148 util::StatusOr<std::unique_ptr<MonitoringClient>> monitoring_client =
149 monitoring_factory->New(
150 MonitoringContext(kPrimitive, kComputeApi, *keyset_info));
151 if (!monitoring_client.ok()) {
152 return monitoring_client.status();
153 }
154 return {absl::make_unique<PrfSetPrimitiveWrapper>(
155 std::move(prf_set), *std::move(monitoring_client))};
156 }
157
158 } // namespace tink
159 } // namespace crypto
160