1 // Copyright 2017 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 #ifndef TINK_AEAD_AES_GCM_KEY_MANAGER_H_ 17 #define TINK_AEAD_AES_GCM_KEY_MANAGER_H_ 18 19 #include <stdint.h> 20 21 #include <memory> 22 #include <string> 23 #include <utility> 24 25 #include "absl/memory/memory.h" 26 #include "absl/status/status.h" 27 #include "absl/strings/str_cat.h" 28 #include "absl/strings/string_view.h" 29 #include "tink/aead.h" 30 #include "tink/aead/cord_aead.h" 31 #include "tink/aead/internal/cord_aes_gcm_boringssl.h" 32 #include "tink/core/key_type_manager.h" 33 #include "tink/core/template_util.h" 34 #include "tink/input_stream.h" 35 #include "tink/internal/fips_utils.h" 36 #include "tink/subtle/aes_gcm_boringssl.h" 37 #include "tink/subtle/random.h" 38 #include "tink/util/constants.h" 39 #include "tink/util/input_stream_util.h" 40 #include "tink/util/secret_data.h" 41 #include "tink/util/status.h" 42 #include "tink/util/statusor.h" 43 #include "tink/util/validation.h" 44 #include "proto/aes_gcm.pb.h" 45 #include "proto/tink.pb.h" 46 47 namespace crypto { 48 namespace tink { 49 50 class AesGcmKeyManager 51 : public KeyTypeManager<google::crypto::tink::AesGcmKey, 52 google::crypto::tink::AesGcmKeyFormat, 53 List<Aead, CordAead>> { 54 public: 55 class AeadFactory : public PrimitiveFactory<Aead> { Create(const google::crypto::tink::AesGcmKey & key)56 crypto::tink::util::StatusOr<std::unique_ptr<Aead>> Create( 57 const google::crypto::tink::AesGcmKey& key) const override { 58 auto aes_gcm_result = subtle::AesGcmBoringSsl::New( 59 util::SecretDataFromStringView(key.key_value())); 60 if (!aes_gcm_result.ok()) return aes_gcm_result.status(); 61 return {std::move(aes_gcm_result.value())}; 62 } 63 }; 64 class CordAeadFactory : public PrimitiveFactory<CordAead> { Create(const google::crypto::tink::AesGcmKey & key)65 crypto::tink::util::StatusOr<std::unique_ptr<CordAead>> Create( 66 const google::crypto::tink::AesGcmKey& key) const override { 67 auto cord_aes_gcm_result = 68 crypto::tink::internal::CordAesGcmBoringSsl::New( 69 util::SecretDataFromStringView(key.key_value())); 70 if (!cord_aes_gcm_result.ok()) return cord_aes_gcm_result.status(); 71 return {std::move(cord_aes_gcm_result.value())}; 72 } 73 }; 74 AesGcmKeyManager()75 AesGcmKeyManager() 76 : KeyTypeManager(absl::make_unique<AesGcmKeyManager::AeadFactory>(), 77 absl::make_unique<AesGcmKeyManager::CordAeadFactory>()) { 78 } 79 80 // Returns the version of this key manager. get_version()81 uint32_t get_version() const override { return 0; } 82 key_material_type()83 google::crypto::tink::KeyData::KeyMaterialType key_material_type() 84 const override { 85 return google::crypto::tink::KeyData::SYMMETRIC; 86 } 87 get_key_type()88 const std::string& get_key_type() const override { return key_type_; } 89 ValidateKey(const google::crypto::tink::AesGcmKey & key)90 crypto::tink::util::Status ValidateKey( 91 const google::crypto::tink::AesGcmKey& key) const override { 92 crypto::tink::util::Status status = 93 ValidateVersion(key.version(), get_version()); 94 if (!status.ok()) return status; 95 return ValidateAesKeySize(key.key_value().size()); 96 } 97 ValidateKeyFormat(const google::crypto::tink::AesGcmKeyFormat & key_format)98 crypto::tink::util::Status ValidateKeyFormat( 99 const google::crypto::tink::AesGcmKeyFormat& key_format) const override { 100 return ValidateAesKeySize(key_format.key_size()); 101 } 102 CreateKey(const google::crypto::tink::AesGcmKeyFormat & key_format)103 crypto::tink::util::StatusOr<google::crypto::tink::AesGcmKey> CreateKey( 104 const google::crypto::tink::AesGcmKeyFormat& key_format) const override { 105 google::crypto::tink::AesGcmKey key; 106 key.set_version(get_version()); 107 key.set_key_value( 108 crypto::tink::subtle::Random::GetRandomBytes(key_format.key_size())); 109 return key; 110 } 111 DeriveKey(const google::crypto::tink::AesGcmKeyFormat & key_format,InputStream * input_stream)112 crypto::tink::util::StatusOr<google::crypto::tink::AesGcmKey> DeriveKey( 113 const google::crypto::tink::AesGcmKeyFormat& key_format, 114 InputStream* input_stream) const override { 115 crypto::tink::util::Status status = 116 ValidateVersion(key_format.version(), get_version()); 117 if (!status.ok()) return status; 118 119 crypto::tink::util::StatusOr<std::string> randomness = 120 ReadBytesFromStream(key_format.key_size(), input_stream); 121 if (!randomness.ok()) { 122 if (randomness.status().code() == absl::StatusCode::kOutOfRange) { 123 return crypto::tink::util::Status( 124 absl::StatusCode::kInvalidArgument, 125 "Could not get enough pseudorandomness from input stream"); 126 } 127 return randomness.status(); 128 } 129 google::crypto::tink::AesGcmKey key; 130 key.set_version(get_version()); 131 key.set_key_value(randomness.value()); 132 return key; 133 } 134 FipsStatus()135 internal::FipsCompatibility FipsStatus() const override { 136 return internal::FipsCompatibility::kRequiresBoringCrypto; 137 } 138 139 private: 140 const std::string key_type_ = absl::StrCat( 141 kTypeGoogleapisCom, google::crypto::tink::AesGcmKey().GetTypeName()); 142 }; 143 144 } // namespace tink 145 } // namespace crypto 146 147 #endif // TINK_AEAD_AES_GCM_KEY_MANAGER_H_ 148