CreateCertificate.java

/*
 * 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
 *
 *     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 privateca;

// [START privateca_create_certificate]

import com.google.api.core.ApiFuture;
import com.google.cloud.kms.v1.CryptoKeyVersionName;
import com.google.cloud.kms.v1.KeyManagementServiceClient;
import com.google.cloud.security.privateca.v1.CaPoolName;
import com.google.cloud.security.privateca.v1.Certificate;
import com.google.cloud.security.privateca.v1.CertificateAuthorityServiceClient;
import com.google.cloud.security.privateca.v1.CertificateConfig;
import com.google.cloud.security.privateca.v1.CertificateConfig.SubjectConfig;
import com.google.cloud.security.privateca.v1.CreateCertificateRequest;
import com.google.cloud.security.privateca.v1.KeyUsage;
import com.google.cloud.security.privateca.v1.KeyUsage.ExtendedKeyUsageOptions;
import com.google.cloud.security.privateca.v1.KeyUsage.KeyUsageOptions;
import com.google.cloud.security.privateca.v1.PublicKey;
import com.google.cloud.security.privateca.v1.PublicKey.KeyFormat;
import com.google.cloud.security.privateca.v1.Subject;
import com.google.cloud.security.privateca.v1.SubjectAltNames;
import com.google.cloud.security.privateca.v1.X509Parameters;
import com.google.cloud.security.privateca.v1.X509Parameters.CaOptions;
import com.google.protobuf.ByteString;
import com.google.protobuf.Duration;
import java.io.IOException;
import java.util.concurrent.ExecutionException;

public class CreateCertificate {

  public static void main(String[] args)
      throws InterruptedException, ExecutionException, IOException {
    // TODO(developer): Replace these variables before running the sample.

    // To sign and issue a certificate, a public key is essential. Here, we are making use
    // of Cloud KMS to retrieve an already created public key. Specify the following details to
    // retrieve the key. For more info, see: https://cloud.google.com/kms/docs/retrieve-public-key
    String project = "your-project-id";
    String kmsLocation = "kms-location";
    String keyRingId = "your-ring-id";
    String keyId = "your-key-id";
    String keyVersionId = "your-version-id";

    // Retrieve the public key from Cloud KMS.
    ByteString publicKeyBytes =
        retrievePublicKey(project, kmsLocation, keyRingId, keyId, keyVersionId);

    // location: For a list of locations, see:
    // https://cloud.google.com/certificate-authority-service/docs/locations
    // caPoolName: Set a unique name for the CA pool.
    // certificateAuthorityName: The name of the certificate authority which issues the certificate.
    // certificateName: Set a unique name for the certificate.
    String location = "ca-location";
    String caPoolName = "ca-pool-name";
    String certificateAuthorityName = "certificate-authority-name";
    String certificateName = "certificate-name";

    createCertificate(
        project, location, caPoolName, certificateAuthorityName, certificateName, publicKeyBytes);
  }

  // Create a Certificate which is issued by the Certificate Authority present in the CA Pool.
  // The key used to sign the certificate is created by the Cloud KMS.
  public static void createCertificate(
      String project,
      String location,
      String caPoolName,
      String certificateAuthorityName,
      String certificateName,
      ByteString publicKeyBytes)
      throws InterruptedException, ExecutionException, IOException {
    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests. After completing all of your requests, call
    // the `certificateAuthorityServiceClient.close()` method on the client to safely
    // clean up any remaining background resources.
    try (CertificateAuthorityServiceClient certificateAuthorityServiceClient =
        CertificateAuthorityServiceClient.create()) {

      // commonName: Enter a title for your certificate.
      // orgName: Provide the name of your company.
      // domainName: List the fully qualified domain name.
      // certificateLifetime: The validity of the certificate in seconds.
      String commonName = "common-name";
      String orgName = "org-name";
      String domainName = "dnsname.com";
      long certificateLifetime = 1000L;

      // Set the Public Key and its format as obtained from the Cloud KMS.
      PublicKey publicKey =
          PublicKey.newBuilder().setKey(publicKeyBytes).setFormat(KeyFormat.PEM).build();

      SubjectConfig subjectConfig =
          SubjectConfig.newBuilder()
              // Set the common name and org name.
              .setSubject(
                  Subject.newBuilder().setCommonName(commonName).setOrganization(orgName).build())
              // Set the fully qualified domain name.
              .setSubjectAltName(SubjectAltNames.newBuilder().addDnsNames(domainName).build())
              .build();

      // Set the X.509 fields required for the certificate.
      X509Parameters x509Parameters =
          X509Parameters.newBuilder()
              .setKeyUsage(
                  KeyUsage.newBuilder()
                      .setBaseKeyUsage(
                          KeyUsageOptions.newBuilder()
                              .setDigitalSignature(true)
                              .setKeyEncipherment(true)
                              .setCertSign(true)
                              .build())
                      .setExtendedKeyUsage(
                          ExtendedKeyUsageOptions.newBuilder().setServerAuth(true).build())
                      .build())
              .setCaOptions(CaOptions.newBuilder().setIsCa(true).buildPartial())
              .build();

      // Create certificate.
      Certificate certificate =
          Certificate.newBuilder()
              .setConfig(
                  CertificateConfig.newBuilder()
                      .setPublicKey(publicKey)
                      .setSubjectConfig(subjectConfig)
                      .setX509Config(x509Parameters)
                      .build())
              .setLifetime(Duration.newBuilder().setSeconds(certificateLifetime).build())
              .build();

      // Create the Certificate Request.
      CreateCertificateRequest certificateRequest =
          CreateCertificateRequest.newBuilder()
              .setParent(CaPoolName.of(project, location, caPoolName).toString())
              .setCertificateId(certificateName)
              .setCertificate(certificate)
              .setIssuingCertificateAuthorityId(certificateAuthorityName)
              .build();

      // Get the Certificate response.
      ApiFuture<Certificate> future =
          certificateAuthorityServiceClient
              .createCertificateCallable()
              .futureCall(certificateRequest);

      Certificate response = future.get();
      // Get the PEM encoded, signed X.509 certificate.
      System.out.println(response.getPemCertificate());
      // To verify the obtained certificate, use this intermediate chain list.
      System.out.println(response.getPemCertificateChainList());
    }
  }

  // Get the public Key used for signing the certificate from Cloud KMS.
  public static ByteString retrievePublicKey(
      String project, String kmsLocation, String keyRingId, String keyId, String keyVersionId)
      throws IOException {
    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests. After completing all of your requests, call
    // the `client.close()` method on the client to safely
    // clean up any remaining background resources.
    try (KeyManagementServiceClient client = KeyManagementServiceClient.create()) {

      CryptoKeyVersionName keyVersionName =
          CryptoKeyVersionName.of(project, kmsLocation, keyRingId, keyId, keyVersionId);
      com.google.cloud.kms.v1.PublicKey publicKey = client.getPublicKey(keyVersionName);

      ByteString publicKeyBytes = publicKey.getPemBytes();
      return publicKeyBytes;
    }
  }
}
// [END privateca_create_certificate]