Client-Side Encryption APIs (SDK for Java)

import com.obs.services.ObsConfiguration;
import com.obs.services.crypto.CTRCipherGenerator;
import com.obs.services.crypto.CryptoObsClient;
import com.obs.services.crypto.CtrRSACipherGenerator;
import com.obs.services.exception.ObsException;
import com.obs.services.model.GetObjectRequest;
import com.obs.services.model.ObsObject;
import com.obs.services.model.PutObjectResult;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.InvalidKeySpecException;

public class CtrRSACipherGeneratorDemo001 {
    public static void main(String[] args) {
        // Obtain an AK/SK pair using environment variables or import the AK/SK pair in other ways. Using hard coding may result in leakage.
        // Obtain an AK/SK pair on the management console.
        String ak = System.getenv("ACCESS_KEY_ID");
        String sk = System.getenv("SECRET_ACCESS_KEY_ID");
        // (Optional) If you are using a temporary AK/SK pair and a security token to access OBS, you are advised not to use hard coding, which may result in information leakage.
        // Obtain an AK/SK pair and a security token using environment variables or import them in other ways.
        // String securityToken = System.getenv("SECURITY_TOKEN");
        // Enter the endpoint corresponding to the bucket. EU-Dublin is used here as an example. Replace it with the one currently in use.
        String endPoint = "https://obs.eu-west-101.myhuaweicloud.eu"; 
        // Obtain an endpoint using environment variables or import it in other ways.
        //String endPoint = System.getenv("ENDPOINT");
        CtrRSACipherGenerator ctrRSACipherGenerator = null;
        try {
            String examplePrivateKeyPath = "yourRSAPrivateKeyPath";
            String examplePublicKeyPath = "yourRSAPublicKeyPath";
            ObsConfiguration config = new ObsConfiguration();
            PrivateKey privateKeyObj = CtrRSACipherGenerator.importPKCS8PrivateKey(examplePrivateKeyPath);
            PublicKey publicKeyObj = CtrRSACipherGenerator.importPublicKey(examplePublicKeyPath);
            ctrRSACipherGenerator =
                    new CtrRSACipherGenerator(
                            "example_master_key_info", true, config.getSecureRandom(), privateKeyObj, publicKeyObj);

        } catch (IllegalArgumentException | IOException | NoSuchAlgorithmException | InvalidKeySpecException e) {
            e.printStackTrace();
        }
        assert ctrRSACipherGenerator != null;
        // Create an ObsClient instance.
        try (CryptoObsClient cryptoObsClient = new CryptoObsClient(ak, sk, securityToken, endPoint, ctrRSACipherGenerator)) {
            String exampleBucketName = "example-bucket";
            String exampleObjectKey = "exampleObjectKey";
            String examplePlainTextFilePath = "examplePlainTextFilePath";
            String exampleDecryptedFilePath = "exampleDecryptedFilePath";
            PutObjectResult putObjectResult =
                    cryptoObsClient.putObject(exampleBucketName, exampleObjectKey, new File(examplePlainTextFilePath));
            System.out.println("HTTP Code: " + putObjectResult.getStatusCode());
            System.out.println("Etag: " + putObjectResult.getEtag());
            // The object is successfully encrypted on the client and then uploaded.
            System.out.println("CtrRSACipherGeneratorDemo001 putObject successfully");

            GetObjectRequest getObjectRequest = new GetObjectRequest(exampleBucketName, exampleObjectKey);
            ObsObject obsObject = cryptoObsClient.getObject(getObjectRequest);
            InputStream input = obsObject.getObjectContent();
            byte[] b = new byte[1024];
            FileOutputStream fileOutputStream = new FileOutputStream(exampleDecryptedFilePath);
            int len;
            while ((len = input.read(b)) != -1) {
                fileOutputStream.write(b, 0, len);
            }
            fileOutputStream.close();
            input.close();

            System.out.println("HTTP Code: " + obsObject.getMetadata().getStatusCode());
            // The object is successfully decrypted on the client and then downloaded.
            System.out.println("CtrRSACipherGeneratorDemo001 getObject successfully");

            // Check whether the file remains the same before encryption and after decryption.
            byte[] plainTextFileSha256 = CTRCipherGenerator.getFileSha256Bytes(examplePlainTextFilePath);
            byte[] decryptedFileSha256 = CTRCipherGenerator.getFileSha256Bytes(exampleDecryptedFilePath);
            String plainTextFileSha256Base64Encoded = CTRCipherGenerator.getBase64Info(plainTextFileSha256);
            String decryptedFileSha256Base64Encoded = CTRCipherGenerator.getBase64Info(decryptedFileSha256);
            System.out.println("plainTextFileSha256 base64 encoded: " + plainTextFileSha256Base64Encoded);
            System.out.println("decryptedFileSha256 base64 encoded: " + decryptedFileSha256Base64Encoded);
            System.out.println(
                    "plainTextFileSha256 equals decryptedFileSha256 ? "
                            + decryptedFileSha256Base64Encoded.equals(plainTextFileSha256Base64Encoded));
            System.out.println("CtrRSACipherGeneratorDemo001 successfully");
        } catch (ObsException e) {
            System.out.println("CtrRSACipherGeneratorDemo001 failed");
            // Request failed. Print the HTTP status code.
            System.out.println("HTTP Code: " + e.getResponseCode());
            // Request failed. Print the server-side error code.
            System.out.println("Error Code:" + e.getErrorCode());
            // Request failed. Print the error details.
            System.out.println("Error Message: " + e.getErrorMessage());
            // Request failed. Print the request ID.
            System.out.println("Request ID:" + e.getErrorRequestId());
            System.out.println("Host ID:" + e.getErrorHostId());
        } catch (Exception e) {
            System.out.println("CtrRSACipherGeneratorDemo001 putObject failed");
            // Print other error details.
            e.printStackTrace();
        }
    }
}