| // Copyright 2022 Google LLC |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| // |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| #include "tink/hybrid/internal/hpke_util.h" |
| |
| #include "absl/strings/str_cat.h" |
| #include "tink/internal/ec_util.h" |
| #include "tink/subtle/common_enums.h" |
| #include "proto/hpke.pb.h" |
| |
| namespace crypto { |
| namespace tink { |
| namespace internal { |
| namespace { |
| |
| util::StatusOr<HpkeKem> HpkeKemProtoToEnum(google::crypto::tink::HpkeKem kem) { |
| switch (kem) { |
| case google::crypto::tink::HpkeKem::DHKEM_X25519_HKDF_SHA256: |
| return HpkeKem::kX25519HkdfSha256; |
| default: |
| return util::Status( |
| absl::StatusCode::kInvalidArgument, |
| absl::StrCat("Unable to convert unsupported HPKE KEM: ", kem)); |
| } |
| } |
| |
| util::StatusOr<HpkeKdf> HpkeKdfProtoToEnum(google::crypto::tink::HpkeKdf kdf) { |
| switch (kdf) { |
| case google::crypto::tink::HpkeKdf::HKDF_SHA256: |
| return HpkeKdf::kHkdfSha256; |
| default: |
| return util::Status( |
| absl::StatusCode::kInvalidArgument, |
| absl::StrCat("Unable to convert unsupported HPKE KDF: ", kdf)); |
| } |
| } |
| |
| util::StatusOr<HpkeAead> HpkeAeadProtoToEnum( |
| google::crypto::tink::HpkeAead aead) { |
| switch (aead) { |
| case google::crypto::tink::HpkeAead::AES_128_GCM: |
| return HpkeAead::kAes128Gcm; |
| case google::crypto::tink::HpkeAead::AES_256_GCM: |
| return HpkeAead::kAes256Gcm; |
| case google::crypto::tink::HpkeAead::CHACHA20_POLY1305: |
| return HpkeAead::kChaCha20Poly1305; |
| default: |
| return util::Status( |
| absl::StatusCode::kInvalidArgument, |
| absl::StrCat("Unable to convert unsupported HPKE AEAD: ", aead)); |
| } |
| } |
| |
| } // namespace |
| |
| util::StatusOr<HpkeParams> HpkeParamsProtoToStruct( |
| google::crypto::tink::HpkeParams params) { |
| util::StatusOr<HpkeKem> kem = HpkeKemProtoToEnum(params.kem()); |
| if (!kem.ok()) return kem.status(); |
| util::StatusOr<HpkeKdf> kdf = HpkeKdfProtoToEnum(params.kdf()); |
| if (!kdf.ok()) return kdf.status(); |
| util::StatusOr<HpkeAead> aead = HpkeAeadProtoToEnum(params.aead()); |
| if (!aead.ok()) return aead.status(); |
| return HpkeParams{*kem, *kdf, *aead}; |
| } |
| |
| util::StatusOr<int32_t> HpkeEncapsulatedKeyLength( |
| google::crypto::tink::HpkeKem kem) { |
| switch (kem) { |
| case google::crypto::tink::HpkeKem::DHKEM_X25519_HKDF_SHA256: |
| return internal::EcPointEncodingSizeInBytes( |
| subtle::EllipticCurveType::CURVE25519, |
| subtle::EcPointFormat::UNCOMPRESSED); |
| default: |
| return util::Status( |
| absl::StatusCode::kInvalidArgument, |
| absl::StrCat("Unable to determine KEM-encoding length for ", kem)); |
| } |
| } |
| |
| } // namespace internal |
| } // namespace tink |
| } // namespace crypto |