Manage bucket ACLs by using OSS SDK for .NET - Object Storage Service

A bucket is a container for objects stored in Object Storage Service (OSS). All objects in OSS are stored in buckets. This topic describes how to configure and query the access control list (ACL) of a bucket.

Usage notes

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 the ACL of a bucket, you must have the oss:PutBucketAcl permission. To query the ACL of a bucket, you must have the oss:GetBucketAcl permission. For more information, see Attach a custom policy to a RAM user.

Configure the ACL of a bucket

The following table describes the bucket ACLs.

ACL	Description	Method
Private	Only the bucket owner and authorized users have read and write permissions on objects in the bucket. Other users cannot access objects in the bucket.	CannedAccessControlList.Private
Public-read	Only the bucket owner and authorized users have read and write permissions on objects in the bucket. Other users have only read permissions on objects in the bucket. Exercise caution when you set the bucket ACL to this value.	CannedAccessControlList.PublicRead
Public-read-write	All users have read and write permissions on the objects in the bucket. Exercise caution when you set the bucket ACL to this value.	CannedAccessControlList.PublicReadWrite

The following sample code provides an example on how to configure the ACL of a bucket:

using System;
using Aliyun.OSS;

namespace Samples
{
    public class Program
    {
        public static void Main(string[] args)
        {
            // Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. 
            var endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
            // Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
            var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
            var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
            // Specify the name of the bucket. Example: examplebucket. 
            var bucketName = "examplebucket";
            // Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
            const string region = "cn-hangzhou";
            // Create a ClientConfiguration instance and modify parameters as required.
            var conf = new ClientConfiguration();
            // Use the signature algorithm V4.
             conf.SignatureVersion = SignatureVersion.V4;
            
            // Create an OSSClient instance.
            var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
            try
            {
                // Set the ACL of the bucket to public-read. 
                client.SetBucketAcl(bucketName, CannedAccessControlList.PublicRead);
                Console.WriteLine("Set bucket ACL succeeded");
            }
            catch (Exception ex)
            {
                Console.WriteLine("Set bucket ACL failed. {0}", ex.Message);
            }
        }
    }
}

Query the ACL of a bucket

The following sample code provides an example on how to query the ACL of a bucket:

using System;
using Aliyun.OSS;

namespace Samples
{
    public class Program
    {
        public static void Main(string[] args)
        {
            // Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. 
            var endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
            // Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
            var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
            var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
            // Specify the name of the bucket. Example: examplebucket. 
            var bucketName = "examplebucket";
            // Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
            const string region = "cn-hangzhou";
            // Create a ClientConfiguration instance and modify parameters as required.
            var conf = new ClientConfiguration();
            // Use the signature algorithm V4.
             conf.SignatureVersion = SignatureVersion.V4;
            
            // Create an OSSClient instance.
            var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
            try
            {

                var acl = client.GetBucketAcl(bucketName);
                Console.WriteLine("Get bucket ACL success {0}", acl.ACL);
            }
            catch (Exception ex)
            {
                Console.WriteLine("Get bucket ACL failed. {0}", ex.Message);
            }
        }
    }
}

References

For the complete sample code that is used to configure the ACL of a bucket, visit GitHub.
For the complete sample code that is used to query the ACL of a bucket, visit GitHub.
For more information about the API operation that you can call to configure the ACL of a bucket, see PutBucketAcl.
For more information about the API operation that you can call to query the ACL of a bucket, see GetBucketAcl.