// Copyright 2021 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.
//
////////////////////////////////////////////////////////////////////////////////

syntax = "proto3";

package google.crypto.tink;

option java_package = "com.google.crypto.tink.proto";
option java_multiple_files = true;
option go_package = "github.com/google/tink/go/proto/hpke_proto";

enum HpkeKem {
  KEM_UNKNOWN = 0;
  DHKEM_X25519_HKDF_SHA256 = 1;
  DHKEM_P256_HKDF_SHA256 = 2;
  DHKEM_P384_HKDF_SHA384 = 3;
  DHKEM_P521_HKDF_SHA512 = 4;
}

enum HpkeKdf {
  KDF_UNKNOWN = 0;
  HKDF_SHA256 = 1;
  HKDF_SHA384 = 2;
  HKDF_SHA512 = 3;
}

enum HpkeAead {
  AEAD_UNKNOWN = 0;
  AES_128_GCM = 1;
  AES_256_GCM = 2;
  CHACHA20_POLY1305 = 3;
}

message HpkeParams {
  HpkeKem kem = 1;
  HpkeKdf kdf = 2;
  HpkeAead aead = 3;
}

message HpkePublicKey {
  uint32 version = 1;
  HpkeParams params = 2;
  // KEM-encoding of public key (i.e., SerializePublicKey() ) as described in
  // https://www.rfc-editor.org/rfc/rfc9180.html#name-cryptographic-dependencies.
  bytes public_key = 3;
}

message HpkePrivateKey {
  uint32 version = 1;
  HpkePublicKey public_key = 2;
  // KEM-encoding of private key (i.e., SerializePrivateKey() ) as described in
  // https://www.rfc-editor.org/rfc/rfc9180.html#name-cryptographic-dependencies.
  bytes private_key = 3;
}

message HpkeKeyFormat {
  HpkeParams params = 1;
}