JAVA Code

package alias_directory_api;
//Doc: https://developer.novopayment.com/api/alias-directory-api/alias-info-api

import cards_api.CardAndAccountBundled;
import com.nimbusds.jose.*;
import com.nimbusds.jose.crypto.RSADecrypter;
import com.nimbusds.jose.crypto.RSAEncrypter;
import org.apache.http.HttpHeaders;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.client.methods.RequestBuilder;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.HttpClients;
import org.bouncycastle.util.io.pem.PemObject;
import org.bouncycastle.util.io.pem.PemReader;
import org.json.JSONObject;

import java.io.*;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.security.KeyFactory;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.logging.Logger;

public class AliasInfoAPI {

    private static Logger LOGGER = Logger.getLogger(CardAndAccountBundled.class.getName());
    final static private String CONST_TRUE = "TRUE";

    public static void main(String[] args) throws Exception {

        //Oauth2 token
        String token = "<BEARER_TOKEN>";

        //To indicate that the request is encrypted
        String encrypted = "TRUE";

        final HttpClient httpClient = HttpClients.custom().build();
        final String baseUrl = "https://sandbox-api.novopayment.com/aliasdirectory/v1";
        String bodyRequest = "{\n" +
                "  \"alias\": \"51934586958\"\n" +
                "}";

        JWEHeader header = null;
        Payload payload = null;

        if(encrypted.equalsIgnoreCase(CONST_TRUE))
        {
            header = new JWEHeader(JWEAlgorithm.RSA_OAEP_256, EncryptionMethod.A256CBC_HS512);
            payload = new Payload(bodyRequest);
            JWEObject jwe = new JWEObject(header, payload);
            RSAPublicKey publicRsaKey = readPublicKey(new File("jwe_public_key.pem"));
            jwe.encrypt(new RSAEncrypter(publicRsaKey));
            bodyRequest = "{\n" +
                    "       \"data\":\""+jwe.serialize()+"\"\n" +
                    "      }";
            System.out.println(bodyRequest);
        }

        StringEntity entity = new StringEntity(bodyRequest);
        HttpUriRequest request = RequestBuilder.post()
                .setUri(baseUrl+"/aliasinfo")
                .setHeader(HttpHeaders.CONTENT_TYPE, "application/json")
                .setHeader(HttpHeaders.AUTHORIZATION, "Bearer "+token)
                .setHeader("X-Encrypted", encrypted)
                .setEntity(entity)
                .build();

        HttpResponse response = null;
        response = httpClient.execute(request);

        BufferedReader reader = null;

        reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));

        String line = "";
        String bodyResponse = "";

        while (true) {
            if (!((line = reader.readLine()) != null)) break;
            bodyResponse+=line;
        }

        if(encrypted.equalsIgnoreCase(CONST_TRUE)) {

            LOGGER.info(bodyResponse);

            // create a decrypter with the specified private RSA key
            RSAPrivateKey privateRsaKey = readPrivateKey("jwe_private_key");
            RSADecrypter decrypter = new RSADecrypter(privateRsaKey);
            JSONObject json = new JSONObject(bodyResponse);
            JWEObject jwe = JWEObject.parse(json.getString("data"));
            // do the decryption
            jwe.decrypt(decrypter);
            json.put("data", jwe.getPayload().toString());
            bodyResponse = json.toString();
        }

        LOGGER.info(bodyResponse);

    }

    public static RSAPublicKey readPublicKey(File file) throws Exception {
        KeyFactory factory = KeyFactory.getInstance("RSA");

        try (FileReader keyReader = new FileReader(file);
             PemReader pemReader = new PemReader(keyReader)) {

            PemObject pemObject = pemReader.readPemObject();
            byte[] content = pemObject.getContent();
            X509EncodedKeySpec pubKeySpec = new X509EncodedKeySpec(content);
            return (RSAPublicKey) factory.generatePublic(pubKeySpec);
        }
    }

    public static RSAPrivateKey readPrivateKey(final String keyfile){
        try {
            Process p;
            p = Runtime.getRuntime().exec("openssl pkcs8 -nocrypt -topk8 -inform PEM " +
                    "-in " + keyfile + ".pem -outform DER -out " + keyfile + ".der");

            p.waitFor();
            System.out.println("Command executed" + (p.exitValue() == 0 ? " successfully" : " with error" ));
        } catch ( IOException | InterruptedException e) {
            e.printStackTrace();
            System.exit(1);
        }

        PrivateKey myPrivKey = null;
        try {
            byte[] keyArray = Files.readAllBytes(Paths.get(keyfile + ".der"));
            PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyArray);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            myPrivKey = keyFactory.generatePrivate(keySpec);
        } catch (IOException | NoSuchAlgorithmException | InvalidKeySpecException e){
            e.printStackTrace();
            System.exit(1);
        }
        RSAPrivateKey rsa = (RSAPrivateKey) myPrivKey;

        return rsa;
    }
}

JAVA Dependencies

plugins {
    // Apply the java plugin to add support for Java
    id 'java'

    // Apply the application plugin to add support for building a CLI application
    id 'application'
}

repositories {
    // Use jcenter for resolving dependencies.
    // You can declare any Maven/Ivy/file repository here.
    jcenter()
}

dependencies {
    // This dependency is used by the application.
    implementation 'com.google.guava:guava:28.0-jre'
    // https://mvnrepository.com/artifact/com.nimbusds/nimbus-jose-jwt
    implementation group: 'com.nimbusds', name: 'nimbus-jose-jwt', version: '9.10'
    // https://mvnrepository.com/artifact/org.bouncycastle/bcpkix-jdk15on
    implementation group: 'org.bouncycastle', name: 'bcpkix-jdk15on', version: '1.69'
    // https://mvnrepository.com/artifact/org.json/json
    implementation group: 'org.json', name: 'json', version: '20210307'

    // Use JUnit test framework
    testImplementation 'junit:junit:4.12'

    compile group: 'org.apache.httpcomponents', name: 'httpclient', version: '4.5.11'
    compile group: 'org.apache.logging.log4j', name: 'log4j-api', version: '2.14.1'
    compile group: 'org.apache.logging.log4j', name: 'log4j-core', version: '2.14.1'

}

application {
    // Define the main class for the application
    mainClassName = 'my_project.App'
}