# Create and activate a root CA programmatically
<a name="JavaApi-ActivateRootCA"></a>

This Java sample shows how to activate a root CA using the following AWS Private CA API actions:
+ [CreateCertificateAuthority](https://docs.aws.amazon.com/privateca/latest/APIReference/API_CreateCertificateAuthority.html)
+ [GetCertificateAuthorityCsr](https://docs.aws.amazon.com/privateca/latest/APIReference/API_GetCertificateAuthorityCsr.html)
+ [IssueCertificate](https://docs.aws.amazon.com/privateca/latest/APIReference/API_IssueCertificate.html)
+ [GetCertificate](https://docs.aws.amazon.com/privateca/latest/APIReference/API_GetCertificate.html)
+ [ImportCertificateAuthorityCertificate](https://docs.aws.amazon.com/privateca/latest/APIReference/API_ImportCertificateAuthorityCertificate.html)

```
package com.amazonaws.samples;

import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.profile.ProfileCredentialsProvider;
import com.amazonaws.client.builder.AwsClientBuilder;
import com.amazonaws.client.builder.AwsClientBuilder.EndpointConfiguration;
import com.amazonaws.samples.GetCertificateAuthorityCertificate;
import com.amazonaws.auth.AWSStaticCredentialsProvider;


import com.amazonaws.services.acmpca.AWSACMPCA;
import com.amazonaws.services.acmpca.AWSACMPCAClientBuilder;

import com.amazonaws.services.acmpca.model.ASN1Subject;
import com.amazonaws.services.acmpca.model.CertificateAuthorityConfiguration;
import com.amazonaws.services.acmpca.model.CertificateAuthorityType;
import com.amazonaws.services.acmpca.model.CreateCertificateAuthorityResult;
import com.amazonaws.services.acmpca.model.CreateCertificateAuthorityRequest;
import com.amazonaws.services.acmpca.model.CrlConfiguration;
import com.amazonaws.services.acmpca.model.KeyAlgorithm;
import com.amazonaws.services.acmpca.model.SigningAlgorithm;
import com.amazonaws.services.acmpca.model.Tag;

import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Objects;

import com.amazonaws.services.acmpca.model.GetCertificateAuthorityCsrRequest;
import com.amazonaws.services.acmpca.model.GetCertificateAuthorityCsrResult;
import com.amazonaws.services.acmpca.model.GetCertificateRequest;
import com.amazonaws.services.acmpca.model.GetCertificateResult;
import com.amazonaws.services.acmpca.model.ImportCertificateAuthorityCertificateRequest;
import com.amazonaws.services.acmpca.model.IssueCertificateRequest;
import com.amazonaws.services.acmpca.model.IssueCertificateResult;
import com.amazonaws.services.acmpca.model.SigningAlgorithm;
import com.amazonaws.services.acmpca.model.Validity;

import com.amazonaws.AmazonClientException;
import com.amazonaws.services.acmpca.model.CertificateMismatchException;
import com.amazonaws.services.acmpca.model.ConcurrentModificationException;
import com.amazonaws.services.acmpca.model.LimitExceededException;
import com.amazonaws.services.acmpca.model.InvalidArgsException;
import com.amazonaws.services.acmpca.model.InvalidArnException;
import com.amazonaws.services.acmpca.model.InvalidPolicyException;
import com.amazonaws.services.acmpca.model.InvalidStateException;
import com.amazonaws.services.acmpca.model.MalformedCertificateException;
import com.amazonaws.services.acmpca.model.MalformedCSRException;
import com.amazonaws.services.acmpca.model.RequestFailedException;
import com.amazonaws.services.acmpca.model.RequestInProgressException;
import com.amazonaws.services.acmpca.model.ResourceNotFoundException;
import com.amazonaws.services.acmpca.model.RevocationConfiguration;
import com.amazonaws.services.acmpca.model.AWSACMPCAException;

import com.amazonaws.waiters.Waiter;
import com.amazonaws.waiters.WaiterParameters;
import com.amazonaws.waiters.WaiterTimedOutException;
import com.amazonaws.waiters.WaiterUnrecoverableException;

public class RootCAActivation {
    public static void main(String[] args) throws Exception {
        // Define the endpoint region for your sample.
        String endpointRegion = "{{region}}"; // Substitute your region here, e.g. "us-west-2"

        // Define a CA subject.
        ASN1Subject subject = new ASN1Subject();
        subject.setOrganization("{{Example Organization}}");
        subject.setOrganizationalUnit("{{Example}}");
        subject.setCountry("{{US}}");
        subject.setState("{{Virginia}}");
        subject.setLocality("{{Arlington}}");
        subject.setCommonName("{{www.example.com}}");

        // Define the CA configuration.
        CertificateAuthorityConfiguration configCA = new CertificateAuthorityConfiguration();
        configCA.withKeyAlgorithm(KeyAlgorithm.RSA_2048);
        configCA.withSigningAlgorithm(SigningAlgorithm.SHA256WITHRSA);
        configCA.withSubject(subject);

        // Define a certificate revocation list configuration.
        CrlConfiguration crlConfigure = new CrlConfiguration();
        crlConfigure.withEnabled(true);
        crlConfigure.withExpirationInDays(365);
        crlConfigure.withCustomCname(null);
        crlConfigure.withS3BucketName("{{your-bucket-name}}");

        // Define a certificate authority type
        CertificateAuthorityType CAtype = CertificateAuthorityType.ROOT;

        // ** Execute core code samples for Root CA activation in sequence **
        AWSACMPCA client = ClientBuilder(endpointRegion);
        String rootCAArn = CreateCertificateAuthority(configCA, crlConfigure, CAtype, client);
        String csr = GetCertificateAuthorityCsr(rootCAArn, client);
        String rootCertificateArn = IssueCertificate(rootCAArn, csr, client);
        String rootCertificate = GetCertificate(rootCertificateArn, rootCAArn, client);
        ImportCertificateAuthorityCertificate(rootCertificate, rootCAArn, client);
    }

    private static AWSACMPCA ClientBuilder(String endpointRegion) {
        // Retrieve your credentials from the C:\Users\name\.aws\credentials file
        // in Windows or the .aws/credentials file in Linux.
        AWSCredentials credentials = null;
        try {
            credentials = new ProfileCredentialsProvider("default").getCredentials();
        } catch (Exception e) {
            throw new AmazonClientException(
                    "Cannot load the credentials from the credential profiles file. " +
                    "Please make sure that your credentials file is at the correct " +
                    "location (C:\\Users\\joneps\\.aws\\credentials), and is in valid format.",
                    e);
        }

        String endpointProtocol = "https://acm-pca." + endpointRegion + ".amazonaws.com/";
        EndpointConfiguration endpoint =
            new AwsClientBuilder.EndpointConfiguration(endpointProtocol, endpointRegion);
        
        // Create a client that you can use to make requests.
        AWSACMPCA client = AWSACMPCAClientBuilder.standard()
            .withEndpointConfiguration(endpoint)
            .withCredentials(new AWSStaticCredentialsProvider(credentials))
            .build();

        return client;
    }

    private static String CreateCertificateAuthority(CertificateAuthorityConfiguration configCA, CrlConfiguration crlConfigure, CertificateAuthorityType CAtype, AWSACMPCA client) {
        RevocationConfiguration revokeConfig = new RevocationConfiguration();
        revokeConfig.setCrlConfiguration(crlConfigure);

        // Create the request object.
        CreateCertificateAuthorityRequest createCARequest = new CreateCertificateAuthorityRequest();
        createCARequest.withCertificateAuthorityConfiguration(configCA);
        createCARequest.withRevocationConfiguration(revokeConfig);
        createCARequest.withIdempotencyToken("123987");
        createCARequest.withCertificateAuthorityType(CAtype);
        
        // Create the private CA.
        CreateCertificateAuthorityResult createCAResult = null;
        try {
            createCAResult = client.createCertificateAuthority(createCARequest);
        } catch (InvalidArgsException ex) {
            throw ex;
        } catch (InvalidPolicyException ex) {
            throw ex;
        } catch (LimitExceededException ex) {
            throw ex;
        }

        // Retrieve the ARN of the private CA.
        String rootCAArn = createCAResult.getCertificateAuthorityArn();
        System.out.println("Root CA Arn: " + rootCAArn);
        
        return rootCAArn;
    }

    private static String GetCertificateAuthorityCsr(String rootCAArn, AWSACMPCA client) {

        // Create the CSR request object and set the CA ARN.
        GetCertificateAuthorityCsrRequest csrRequest = new GetCertificateAuthorityCsrRequest();
        csrRequest.withCertificateAuthorityArn(rootCAArn);

        // Create waiter to wait on successful creation of the CSR file.
        Waiter<GetCertificateAuthorityCsrRequest> getCSRWaiter = client.waiters().certificateAuthorityCSRCreated();
        try {
            getCSRWaiter.run(new WaiterParameters<>(csrRequest));
        } catch (WaiterUnrecoverableException e) {
            //Explicit short circuit when the recourse transitions into
            //an undesired state.
        } catch (WaiterTimedOutException e) {
            //Failed to transition into desired state even after polling.
        } catch (AWSACMPCAException e) {
            //Unexpected service exception.
        }

        // Retrieve the CSR.
        GetCertificateAuthorityCsrResult csrResult = null;
        try {
            csrResult = client.getCertificateAuthorityCsr(csrRequest);
        } catch (RequestInProgressException ex) {
            throw ex;
        } catch (ResourceNotFoundException ex) {
            throw ex;
        } catch (InvalidArnException ex) {
            throw ex;
        } catch (RequestFailedException ex) {
            throw ex;
        }

        // Retrieve and display the CSR;
        String csr = csrResult.getCsr();
        System.out.println(csr);

        return csr;
    }

    private static String IssueCertificate(String rootCAArn, String csr, AWSACMPCA client) {

        // Create a certificate request:
        IssueCertificateRequest issueRequest = new IssueCertificateRequest();

        // Set the CA ARN.
        issueRequest.withCertificateAuthorityArn(rootCAArn);

        // Set the template ARN.
        issueRequest.withTemplateArn("arn:aws:acm-pca:::template/RootCACertificate/V1");

        ByteBuffer csrByteBuffer = stringToByteBuffer(csr);
        issueRequest.setCsr(csrByteBuffer);

        // Set the signing algorithm.
        issueRequest.withSigningAlgorithm(SigningAlgorithm.SHA256WITHRSA);

        // Set the validity period for the certificate to be issued.
        Validity validity = new Validity();
        validity.withValue(3650L);
        validity.withType("DAYS");
        issueRequest.withValidity(validity);

        // Set the idempotency token.
        issueRequest.setIdempotencyToken("1234");

        // Issue the certificate.
        IssueCertificateResult issueResult = null;
        try {
            issueResult = client.issueCertificate(issueRequest);
        } catch (LimitExceededException ex) {
            throw ex;
        } catch (ResourceNotFoundException ex) {
            throw ex;
        } catch (InvalidStateException ex) {
            throw ex;
        } catch (InvalidArnException ex) {
            throw ex;
        } catch (InvalidArgsException ex) {
            throw ex;
        } catch (MalformedCSRException ex) {
            throw ex;
        }

        // Retrieve and display the certificate ARN.
        String rootCertificateArn = issueResult.getCertificateArn();
        System.out.println("Root Certificate Arn: " + rootCertificateArn);

        return rootCertificateArn;
    }
    
    private static String GetCertificate(String rootCertificateArn, String rootCAArn, AWSACMPCA client) {

        // Create a request object.
        GetCertificateRequest certificateRequest = new GetCertificateRequest();

        // Set the certificate ARN.
        certificateRequest.withCertificateArn(rootCertificateArn);

        // Set the certificate authority ARN.
        certificateRequest.withCertificateAuthorityArn(rootCAArn);
                
        // Create waiter to wait on successful creation of the certificate file.
        Waiter<GetCertificateRequest> getCertificateWaiter = client.waiters().certificateIssued();
        try {
            getCertificateWaiter.run(new WaiterParameters<>(certificateRequest));
        } catch (WaiterUnrecoverableException e) {
            //Explicit short circuit when the recourse transitions into
            //an undesired state.
        } catch (WaiterTimedOutException e) {
            //Failed to transition into desired state even after polling.
        } catch (AWSACMPCAException e) {
            //Unexpected service exception.
        }

        // Retrieve the certificate and certificate chain.
        GetCertificateResult certificateResult = null;
        try {
            certificateResult = client.getCertificate(certificateRequest);
        } catch (RequestInProgressException ex) {
            throw ex;
        } catch (RequestFailedException ex) {
            throw ex;
        } catch (ResourceNotFoundException ex) {
            throw ex;
        } catch (InvalidArnException ex) {
            throw ex;
        } catch (InvalidStateException ex) {
            throw ex;
        }

        // Get the certificate and certificate chain and display the result.
        String rootCertificate = certificateResult.getCertificate();
        System.out.println(rootCertificate);

        return rootCertificate;
    }

    private static void ImportCertificateAuthorityCertificate(String rootCertificate, String rootCAArn, AWSACMPCA client) {

        // Create the request object and set the signed certificate, chain and CA ARN.
        ImportCertificateAuthorityCertificateRequest importRequest =
            new ImportCertificateAuthorityCertificateRequest();

        ByteBuffer certByteBuffer = stringToByteBuffer(rootCertificate);
        importRequest.setCertificate(certByteBuffer);

        importRequest.setCertificateChain(null);

        // Set the certificate authority ARN.
        importRequest.withCertificateAuthorityArn(rootCAArn);

        // Import the certificate.
        try {
            client.importCertificateAuthorityCertificate(importRequest);
        } catch (CertificateMismatchException ex) {
            throw ex;
        } catch (MalformedCertificateException ex) {
            throw ex;
        } catch (InvalidArnException ex) {
            throw ex;
        } catch (ResourceNotFoundException ex) {
            throw ex;
        } catch (RequestInProgressException ex) {
            throw ex;
        } catch (ConcurrentModificationException ex) {
            throw ex;
        } catch (RequestFailedException ex) {
            throw ex;
        }

        System.out.println("Root CA certificate successfully imported.");
        System.out.println("Root CA activated successfully.");
    }
    
    private static ByteBuffer stringToByteBuffer(final String string) {
        if (Objects.isNull(string)) {
            return null;
        }
        byte[] bytes = string.getBytes(StandardCharsets.UTF_8);
        return ByteBuffer.wrap(bytes);
    }
}
```