C# server-side encryption - Object Storage Service - Alibaba Cloud Documentation Center

Object Storage Service (OSS) can encrypt uploaded data on the server. This is called server-side encryption. When you upload data to OSS, OSS encrypts the uploaded data and then persistently stores the encrypted data. When you download data from OSS, OSS decrypts the data and returns the decrypted data. In addition, a header is added to the response to declare that the data is encrypted on the server.

Usage notes

Before you configure server-side encryption, make sure you understand the feature. For more information, see Server-side encryption.

In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS from other Alibaba Cloud services in the same region as OSS, use an internal endpoint. For more information about OSS regions and endpoints, see Regions and endpoints.
In this topic, an OSSClient instance is created by using an OSS endpoint. If you want to create an OSSClient instance by using custom domain names or Security Token Service (STS), see Initialization.
To configure server-side encryption for a bucket, you must have the oss:PutBucketEncryption permission. To query the server-side encryption configurations of a bucket, you must have the oss:GetBucketEncryption permission. To delete the server-side encryption configurations of a bucket, you must have the oss:DeleteBucketEncryption permission. For more information, see Attach a custom policy to a RAM user.

Configure bucket encryption

The following sample code provides examples on how to configure a default encryption method for a bucket. After you configure the default encryption method, all objects that are uploaded to the bucket without specifying an encryption method are encrypted by using the default encryption method.

using Aliyun.OSS;
using Aliyun.OSS.Common;
// Replace yourEndpoint with the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com.
var endpoint = "yourEndpoint";
// Obtain access credentials from environment variables. Before you run this sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set.
var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
// Specify the bucket name. For example, examplebucket.
var bucketName = "examplebucket";
// Specify the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou.
const string region = "cn-hangzhou";

// Create a ClientConfiguration instance and modify the default parameters as needed.
var conf = new ClientConfiguration();

// Set the signature version to V4.
conf.SignatureVersion = SignatureVersion.V4;

// Create an OssClient instance.
var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
client.SetRegion(region);
try
{
    // Configure bucket encryption.
    var request = new SetBucketEncryptionRequest(bucketName, "KMS", null);
    client.SetBucketEncryption(request);
    Console.WriteLine("Set bucket:{0} Encryption succeeded ", bucketName);
}
catch (OssException ex)
{
    Console.WriteLine("Failed with error code: {0}; Error info: {1}. \nRequestID:{2}\tHostID:{3}",
        ex.ErrorCode, ex.Message, ex.RequestId, ex.HostId);
}
catch (Exception ex)
{
    Console.WriteLine("Failed with error info: {0}", ex.Message);
}

Get bucket encryption configuration

The following sample code provides an example on how to query the server-side encryption configurations of a bucket:

using Aliyun.OSS;
using Aliyun.OSS.Common;
// Replace yourEndpoint with the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com.
var endpoint = "yourEndpoint";
// Obtain access credentials from environment variables. Before you run this sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set.
var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
// Specify the bucket name. For example, examplebucket.
var bucketName = "examplebucket";
// Specify the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou.
const string region = "cn-hangzhou";

// Create a ClientConfiguration instance and modify the default parameters as needed.
var conf = new ClientConfiguration();

// Set the signature version to V4.
conf.SignatureVersion = SignatureVersion.V4;

// Create an OssClient instance.
var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
client.SetRegion(region);
try
{
    // Get the bucket encryption configuration.
    var result = client.GetBucketEncryption(bucketName);
    Console.WriteLine("Get bucket:{0} Encryption succeeded ", bucketName);

    Console.WriteLine("SSEAlgorithm: {0}", result.SSEAlgorithm);
    Console.WriteLine("KMSMasterKeyID: {0}", result.KMSMasterKeyID);

}
catch (OssException ex)
{
    Console.WriteLine("Failed with error code: {0}; Error info: {1}. \nRequestID:{2}\tHostID:{3}",
        ex.ErrorCode, ex.Message, ex.RequestId, ex.HostId);
}
catch (Exception ex)
{
    Console.WriteLine("Failed with error info: {0}", ex.Message);
}

Delete bucket encryption configuration

The following sample code provides an example on how to delete the server-side encryption configurations of a bucket:

using Aliyun.OSS;
using Aliyun.OSS.Common;
// Replace yourEndpoint with the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com.
var endpoint = "yourEndpoint";
// Obtain access credentials from environment variables. Before you run this sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set.
var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
// Specify the bucket name. For example, examplebucket.
var bucketName = "examplebucket";
// Specify the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou.
const string region = "cn-hangzhou";

// Create a ClientConfiguration instance and modify the default parameters as needed.
var conf = new ClientConfiguration();

// Set the signature version to V4.
conf.SignatureVersion = SignatureVersion.V4;

// Create an OssClient instance.
var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
client.SetRegion(region);
try
{
    // Delete the bucket encryption configuration.
    client.DeleteBucketEncryption(bucketName);
    Console.WriteLine("Delete bucket:{0} Encryption succeeded ", bucketName);
}
catch (OssException ex)
{
    Console.WriteLine("Failed with error code: {0}; Error info: {1}. \nRequestID:{2}\tHostID:{3}",
        ex.ErrorCode, ex.Message, ex.RequestId, ex.HostId);
}
catch (Exception ex)
{
    Console.WriteLine("Failed with error info: {0}", ex.Message);
}

References

For more information about the API operation for setting server-side encryption, see PutBucketEncryption.
For more information about the API operation for retrieving the server-side encryption configuration, see GetBucketEncryption.
For more information about the API operation for deleting the server-side encryption configuration, see DeleteBucketEncryption.