| // 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. |
| // |
| //////////////////////////////////////////////////////////////////////////////// |
| |
| package jwt |
| |
| import ( |
| "errors" |
| "fmt" |
| |
| "google.golang.org/protobuf/proto" |
| "github.com/google/tink/go/core/registry" |
| "github.com/google/tink/go/keyset" |
| "github.com/google/tink/go/signature/subtle" |
| jepb "github.com/google/tink/go/proto/jwt_ecdsa_go_proto" |
| tinkpb "github.com/google/tink/go/proto/tink_go_proto" |
| ) |
| |
| const ( |
| jwtECDSAVerifierKeyVersion = 0 |
| jwtECDSAVerifierTypeURL = "type.googleapis.com/google.crypto.tink.JwtEcdsaPublicKey" |
| jwtECDSAEncoding = "IEEE_P1363" |
| ) |
| |
| var ( |
| errECDSAInvalidAlgorithm = errors.New("invalid algorithm") |
| errECDSAVerifierNotImplemented = errors.New("not supported on verifier key manager") |
| ) |
| |
| // jwtECDSAVerifierKeyManager implements the KeyManager interface |
| // for JWT Verifier using the 'ES256', 'ES384', and 'ES512' JWA algorithm. |
| type jwtECDSAVerifierKeyManager struct{} |
| |
| var _ registry.KeyManager = (*jwtECDSAVerifierKeyManager)(nil) |
| |
| type ecdsaParams struct { |
| Curve string |
| Hash string |
| } |
| |
| var esAlgToParams = map[jepb.JwtEcdsaAlgorithm]ecdsaParams{ |
| jepb.JwtEcdsaAlgorithm_ES256: {Curve: "NIST_P256", Hash: "SHA256"}, |
| jepb.JwtEcdsaAlgorithm_ES384: {Curve: "NIST_P384", Hash: "SHA384"}, |
| jepb.JwtEcdsaAlgorithm_ES512: {Curve: "NIST_P521", Hash: "SHA512"}, |
| } |
| |
| func (km *jwtECDSAVerifierKeyManager) Primitive(serializedKey []byte) (interface{}, error) { |
| if serializedKey == nil || len(serializedKey) == 0 { |
| return nil, fmt.Errorf("invalid key") |
| } |
| pubKey := &jepb.JwtEcdsaPublicKey{} |
| if err := proto.Unmarshal(serializedKey, pubKey); err != nil { |
| return nil, err |
| } |
| if err := keyset.ValidateKeyVersion(pubKey.Version, jwtECDSAVerifierKeyVersion); err != nil { |
| return nil, fmt.Errorf("invalid key: %v", err) |
| } |
| params, ok := esAlgToParams[pubKey.GetAlgorithm()] |
| if !ok { |
| return nil, errECDSAInvalidAlgorithm |
| } |
| tv, err := subtle.NewECDSAVerifier(params.Hash, params.Curve, jwtECDSAEncoding, pubKey.GetX(), pubKey.GetY()) |
| if err != nil { |
| return nil, err |
| } |
| return newVerifierWithKID(tv, pubKey.GetAlgorithm().String(), ecdsaCustomKID(pubKey)) |
| } |
| |
| func (km *jwtECDSAVerifierKeyManager) NewKey(serializedKeyFormat []byte) (proto.Message, error) { |
| return nil, errECDSAVerifierNotImplemented |
| } |
| |
| func (km *jwtECDSAVerifierKeyManager) NewKeyData(serializedKeyFormat []byte) (*tinkpb.KeyData, error) { |
| return nil, errECDSAVerifierNotImplemented |
| } |
| |
| func (km *jwtECDSAVerifierKeyManager) DoesSupport(typeURL string) bool { |
| return typeURL == jwtECDSAVerifierTypeURL |
| } |
| |
| func (km *jwtECDSAVerifierKeyManager) TypeURL() string { |
| return jwtECDSAVerifierTypeURL |
| } |
| |
| func ecdsaCustomKID(pk *jepb.JwtEcdsaPublicKey) *string { |
| if pk.GetCustomKid() == nil { |
| return nil |
| } |
| k := pk.GetCustomKid().GetValue() |
| return &k |
| } |