java/src/main/java/com/google/crypto/tink/signature/EcdsaVerifyKeyManager.java

// Copyright 2017 Google Inc.
//
// 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 com.google.crypto.tink.signature;

import com.google.crypto.tink.KeyTypeManager;
import com.google.crypto.tink.PublicKeyVerify;
import com.google.crypto.tink.proto.EcdsaPublicKey;
import com.google.crypto.tink.proto.KeyData.KeyMaterialType;
import com.google.crypto.tink.subtle.EcdsaVerifyJce;
import com.google.crypto.tink.subtle.EllipticCurves;
import com.google.crypto.tink.subtle.Validators;
import com.google.protobuf.ByteString;
import com.google.protobuf.InvalidProtocolBufferException;
import java.security.GeneralSecurityException;
import java.security.interfaces.ECPublicKey;

/**
 * This key manager produces new instances of {@code EcdsaVerifyJce}. It doesn't support key
 * generation.
 */
class EcdsaVerifyKeyManager extends KeyTypeManager<EcdsaPublicKey> {
  public EcdsaVerifyKeyManager() {
    super(
        EcdsaPublicKey.class,
        new PrimitiveFactory<PublicKeyVerify, EcdsaPublicKey>(PublicKeyVerify.class) {
          @Override
          public PublicKeyVerify getPrimitive(EcdsaPublicKey keyProto)
              throws GeneralSecurityException {
            ECPublicKey publicKey =
                EllipticCurves.getEcPublicKey(
                    SigUtil.toCurveType(keyProto.getParams().getCurve()),
                    keyProto.getX().toByteArray(),
                    keyProto.getY().toByteArray());
            return new EcdsaVerifyJce(
                publicKey,
                SigUtil.toHashType(keyProto.getParams().getHashType()),
                SigUtil.toEcdsaEncoding(keyProto.getParams().getEncoding()));
          }
        });
  }

  @Override
  public String getKeyType() {
    return "type.googleapis.com/google.crypto.tink.EcdsaPublicKey";
  }

  @Override
  public int getVersion() {
    return 0;
  }

  @Override
  public KeyMaterialType keyMaterialType() {
    return KeyMaterialType.ASYMMETRIC_PUBLIC;
  }

  @Override
  public EcdsaPublicKey parseKey(ByteString byteString) throws InvalidProtocolBufferException {
    return EcdsaPublicKey.parseFrom(byteString);
  }

  @Override
  public void validateKey(EcdsaPublicKey pubKey) throws GeneralSecurityException {
    Validators.validateVersion(pubKey.getVersion(), getVersion());
    SigUtil.validateEcdsaParams(pubKey.getParams());
  }
}