| // 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. |
| // |
| //////////////////////////////////////////////////////////////////////////////// |
| |
| package hybrid |
| |
| import ( |
| "errors" |
| "fmt" |
| "math/big" |
| |
| "github.com/golang/protobuf/proto" |
| "github.com/google/tink/go/core/registry" |
| "github.com/google/tink/go/keyset" |
| subtle "github.com/google/tink/go/subtle/hybrid" |
| eahpb "github.com/google/tink/proto/ecies_aead_hkdf_go_proto" |
| tinkpb "github.com/google/tink/proto/tink_go_proto" |
| ) |
| |
| const ( |
| eciesAEADHKDFPublicKeyKeyVersion = 0 |
| |
| eciesAEADHKDFPublicKeyTypeURL = "type.googleapis.com/google.crypto.tink.EciesAeadHkdfPublicKey" |
| ) |
| |
| // common errors |
| var errInvalidECIESAEADHKDFPublicKeyKey = fmt.Errorf("ecies_aead_hkdf_public_key_manager: invalid key") |
| var errInvalidECIESAEADHKDFPublicKeyKeyFormat = fmt.Errorf("ecies_aead_hkdf_public_key_manager: invalid key format") |
| |
| // eciesAEADHKDFPublicKeyKeyManager is an implementation of KeyManager interface. |
| // It generates new ECIESAEADHKDFPublicKeyKey keys and produces new instances of ECIESAEADHKDFPublicKey subtle. |
| type eciesAEADHKDFPublicKeyKeyManager struct{} |
| |
| // Assert that eciesAEADHKDFPublicKeyKeyManager implements the KeyManager interface. |
| var _ registry.KeyManager = (*eciesAEADHKDFPublicKeyKeyManager)(nil) |
| |
| // newECIESAEADHKDFPublicKeyKeyManager creates a new aesGcmKeyManager. |
| func newECIESAEADHKDFPublicKeyKeyManager() *eciesAEADHKDFPublicKeyKeyManager { |
| return new(eciesAEADHKDFPublicKeyKeyManager) |
| } |
| |
| // Primitive creates an ECIESAEADHKDFPublicKey subtle for the given serialized ECIESAEADHKDFPublicKey proto. |
| func (km *eciesAEADHKDFPublicKeyKeyManager) Primitive(serializedKey []byte) (interface{}, error) { |
| if len(serializedKey) == 0 { |
| return nil, errInvalidECIESAEADHKDFPublicKeyKey |
| } |
| key := new(eahpb.EciesAeadHkdfPublicKey) |
| if err := proto.Unmarshal(serializedKey, key); err != nil { |
| return nil, errInvalidECIESAEADHKDFPublicKeyKey |
| } |
| if err := km.validateKey(key); err != nil { |
| return nil, errInvalidECIESAEADHKDFPublicKeyKey |
| } |
| curve, err := subtle.GetCurve(key.Params.KemParams.CurveType.String()) |
| if err != nil { |
| return nil, err |
| } |
| pub := subtle.ECPublicKey{ |
| Curve: curve, |
| Point: subtle.ECPoint{ |
| X: new(big.Int).SetBytes(key.X), |
| Y: new(big.Int).SetBytes(key.Y), |
| }, |
| } |
| rDem, err := newRegisterECIESAEADHKDFDemHelper(key.Params.DemParams.AeadDem) |
| if err != nil { |
| return nil, err |
| } |
| salt := key.Params.KemParams.HkdfSalt |
| hash := key.Params.KemParams.HkdfHashType.String() |
| ptFormat := key.Params.EcPointFormat.String() |
| |
| return subtle.NewECIESAEADHKDFHybridEncrypt(&pub, salt, hash, ptFormat, rDem) |
| } |
| |
| // DoesSupport indicates if this key manager supports the given key type. |
| func (km *eciesAEADHKDFPublicKeyKeyManager) DoesSupport(typeURL string) bool { |
| return typeURL == eciesAEADHKDFPublicKeyTypeURL |
| } |
| |
| // TypeURL returns the key type of keys managed by this key manager. |
| func (km *eciesAEADHKDFPublicKeyKeyManager) TypeURL() string { |
| return eciesAEADHKDFPublicKeyTypeURL |
| } |
| |
| // validateKey validates the given ECDSAPrivateKey. |
| func (km *eciesAEADHKDFPublicKeyKeyManager) validateKey(key *eahpb.EciesAeadHkdfPublicKey) error { |
| if err := keyset.ValidateKeyVersion(key.Version, eciesAEADHKDFPublicKeyKeyVersion); err != nil { |
| return fmt.Errorf("ecies_aead_hkdf_public_key_manager: invalid key: %s", err) |
| } |
| return checkECIESAEADHKDFParams(key.Params) |
| } |
| |
| // NewKey is not implemented for public key manager. |
| func (km *eciesAEADHKDFPublicKeyKeyManager) NewKey(serializedKeyFormat []byte) (proto.Message, error) { |
| return nil, errors.New("public key manager does not implement NewKey") |
| } |
| |
| // NewKeyData is not implemented for public key manager. |
| func (km *eciesAEADHKDFPublicKeyKeyManager) NewKeyData(serializedKeyFormat []byte) (*tinkpb.KeyData, error) { |
| return nil, errors.New("public key manager does not implement NewKeyData") |
| } |