Object Storage Service:Bucket policies (C# SDK V1)

Usage notes

• Before you configure a bucket policy, make sure that you understand this feature. For more information, see Bucket policies.

• 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 set a bucket policy, you must have the oss:PutBucketPolicy permission. To get a bucket policy, you must have the oss:GetBucketPolicy permission. To delete a bucket policy, you must have the oss:DeleteBucketPolicy permission. For more information, see Attach a custom policy to a RAM user.

Set a bucket policy

Below is the sample code for setting a bucket policy:

using Aliyun.OSS;
using Aliyun.OSS.Common;
// Set yourEndpoint to the endpoint of the region where your bucket is located. For example, if your 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 the 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");
// Set the bucket name.
var bucketName = "examplebucket";
// Set Region to the ID of the region where your bucket is located. For example, if your bucket is in the China (Hangzhou) region, set Region to cn-hangzhou.
const string region = "cn-hangzhou";

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

// Use Signature V4.
conf.SignatureVersion = SignatureVersion.V4;

// Create an OssClient instance.
var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
client.SetRegion(region);
try
{
    // In this example, the bucket owner (UID 174649585760xxxx) uses a bucket policy to grant a specified RAM user (UID 20214760404935xxxx) the permissions to list all objects in the examplebucket bucket.
    string policy = "{\"Version\":\"1\",\"Statement\":[{\"Action\":[\"oss:ListObjects\",\"oss:GetObject\"], \"Principal": \"20214760404935xxxx"\, \"Resource\": \"acs:oss:*:174649585760xxxx:examplebucket\*",\"Effect\": \"Allow\"}]}\n";
    var request = new SetBucketPolicyRequest(bucketName, policy);
    client.SetBucketPolicy(request);
    Console.WriteLine("Set bucket:{0} Policy 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 a bucket policy

Below is the sample code for getting a bucket policy:

using Aliyun.OSS;
using Aliyun.OSS.Common;
// Set yourEndpoint to the endpoint of the region where your bucket is located. For example, if your 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 the 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");
// Set the bucket name.
var bucketName = "examplebucket";
// Set Region to the ID of the region where your bucket is located. For example, if your bucket is in the China (Hangzhou) region, set Region to cn-hangzhou.
const string region = "cn-hangzhou";

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

// Use Signature V4.
conf.SignatureVersion = SignatureVersion.V4;

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

    Console.WriteLine("Policy: {0}", result.Policy);
}
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 a bucket policy

Below is the sample code for deleting a bucket policy:

using Aliyun.OSS;
using Aliyun.OSS.Common;
// Set yourEndpoint to the endpoint of the region where your bucket is located. For example, if your 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 the 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");
// Set the bucket name.
var bucketName = "examplebucket";
// Set Region to the ID of the region where your bucket is located. For example, if your bucket is in the China (Hangzhou) region, set Region to cn-hangzhou.
const string region = "cn-hangzhou";

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

// Use Signature V4.
conf.SignatureVersion = SignatureVersion.V4;

// Create an OssClient instance.
var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
client.SetRegion(region);
try
{
    // Delete the bucket policy.
    client.DeleteBucketPolicy(bucketName);
    Console.WriteLine("Delete bucket:{0} Policy 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 a bucket policy, see PutBucketPolicy.

• For more information about the API operation for retrieving a bucket policy, see GetBucketPolicy.

• For more information about the API operation for deleting a bucket policy, see DeleteBucketPolicy.