/*
    * Copyright 2024 The Netty Project
    *
    * The Netty Project licenses this file to you 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:
    *
    *   https://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 io.netty.pkitesting;
  
  import org.bouncycastle.asn1.ASN1Encodable;
  import org.bouncycastle.asn1.ASN1ObjectIdentifier;
  import org.bouncycastle.asn1.ASN1Primitive;
  import org.bouncycastle.asn1.DERBitString;
  import org.bouncycastle.asn1.DERSequence;
  import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
  
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.UncheckedIOException;
  import java.security.InvalidKeyException;
  import java.security.NoSuchAlgorithmException;
  import java.security.PrivateKey;
  import java.security.Signature;
  import java.security.SignatureException;
  import java.util.Objects;
  
  final class Signed {
      private final byte[] toBeSigned;
      private final String algorithmIdentifier;
      private final PrivateKey privateKey;
  
      Signed(byte[] toBeSigned, X509Bundle signer) {
          this(toBeSigned, signer.getCertificate().getSigAlgName(), signer.getKeyPair().getPrivate());
      }
  
      Signed(byte[] toBeSigned, String algorithmIdentifier, PrivateKey privateKey) {
          this.toBeSigned = Objects.requireNonNull(toBeSigned, "toBeSigned");
          this.algorithmIdentifier = Objects.requireNonNull(algorithmIdentifier, "algorithmIdentifier");
          this.privateKey = privateKey;
      }
  
      byte[] getEncoded() throws NoSuchAlgorithmException, InvalidKeyException, SignatureException {
          Signature signature = Algorithms.signature(algorithmIdentifier);
          signature.initSign(privateKey);
          signature.update(toBeSigned);
          byte[] signatureBytes = signature.sign();
          try {
              return new DERSequence(new ASN1Encodable[]{
                      ASN1Primitive.fromByteArray(toBeSigned),
                      new AlgorithmIdentifier(new ASN1ObjectIdentifier(
                              Algorithms.oidForAlgorithmName(algorithmIdentifier))),
                      new DERBitString(signatureBytes)
              }).getEncoded("DER");
          } catch (IOException e) {
              throw new UncheckedIOException(e);
          }
      }
  
      InputStream toInputStream() throws NoSuchAlgorithmException, SignatureException, InvalidKeyException {
          return new ByteArrayInputStream(getEncoded());
      }
  }