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Bucket ACLs

Updated at: 2025-03-23 15:15
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This topic contains important information on necessary precautions. We recommend that you read this topic carefully before proceeding.

To implement coarse-grained access control on a bucket, such as the same read/write permissions on all objects in the bucket, you can configure an ACL for the bucket. The ACL of a bucket can be public-read, public-read-write, or private. You can configure the ACL of a bucket when you create the bucket or modify the ACL of an existing bucket based on your business requirements.

Usage notes

  • Only the owner of a bucket can modify the ACL of the bucket.

  • If you modify the ACL of a bucket, the ACLs of all objects that inherit the bucket ACL change accordingly.

  • If you do not specify an ACL for an object when you upload the object to a bucket, the ACL of the object inherits the ACL of the bucket.

ACL types

The following table describes the types of bucket ACLs.

ACL

Description

ACL

Description

public-read-write

All users, including anonymous users, can read data from and write data to the bucket.

Warning

If you set the ACL of a bucket to public read/write, all users can access the objects in the bucket and write data to the bucket over the Internet. This may result in unauthorized access to the data in your bucket and high costs. If a user uploads prohibited data or information, your legitimate interests and rights may be infringed. Therefore, we recommend that you do not set the ACL of a bucket to public-read-write unless necessary.

public-read

Only the bucket owner can write data to objects in the bucket. Other users, including anonymous users, can only read objects in the bucket.

Warning

This may result in unexpected access to the data in your bucket and unexpectedly high costs. Exercise caution when you set your bucket ACL to this value.

private

Only the bucket owner can read data from and write data to objects in the bucket. Other users cannot access the objects in the bucket. This is the default value.

Methods

Use the OSS console

  1. Log on to the OSS console.

  2. In the left-side navigation pane, click Buckets. On the Buckets page, find and click the desired bucket.

  3. In the left-side navigation tree, choose Permission Control > ACL.

  4. On the ACL tab, click Settings to modify the ACL of the bucket.

  5. Click Save.

Use ossbrowser

You can use ossbrowser to perform the same bucket-level operations that you can perform in the OSS console. You can follow the on-screen instructions in ossbrowser to modify the ACL of a bucket. For more information, see Use ossbrowser.

Use OSS SDKs

The following sample code provides examples on how to modify the ACL of a bucket by using OSS SDKs for common programming languages. For more information about how to modify the ACL of a bucket by using OSS SDKs for other programming languages, see Overview.

Java
PHP
Node.js
Python
C++
C
Ruby
Go
import com.aliyun.oss.ClientException;
import com.aliyun.oss.OSS;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.OSSException;
import com.aliyun.oss.model.CannedAccessControlList;

public class Demo {

    public static void main(String[] args) throws Exception {
        // In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
        String 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. 
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // Specify the name of the bucket. Example: examplebucket. 
        String 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.
        String region = "cn-hangzhou";

        // Create an OSSClient instance. 
        ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
        clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);        
        OSS ossClient = OSSClientBuilder.create()
        .endpoint(endpoint)
        .credentialsProvider(credentialsProvider)
        .clientConfiguration(clientBuilderConfiguration)
        .region(region)               
        .build();

        try {
            // Specify the ACL of the bucket. In this example, the ACL of the examplebucket bucket is set to private. 
            ossClient.setBucketAcl(bucketName, CannedAccessControlList.Private);
        } catch (OSSException oe) {
            System.out.println("Caught an OSSException, which means your request made it to OSS, "
                    + "but was rejected with an error response for some reason.");
            System.out.println("Error Message:" + oe.getErrorMessage());
            System.out.println("Error Code:" + oe.getErrorCode());
            System.out.println("Request ID:" + oe.getRequestId());
            System.out.println("Host ID:" + oe.getHostId());
        } catch (ClientException ce) {
            System.out.println("Caught an ClientException, which means the client encountered "
                    + "a serious internal problem while trying to communicate with OSS, "
                    + "such as not being able to access the network.");
            System.out.println("Error Message:" + ce.getMessage());
        } finally {
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }
    }
}
<?php
if (is_file(__DIR__ . '/../autoload.php')) {
    require_once __DIR__ . '/../autoload.php';
}
if (is_file(__DIR__ . '/../vendor/autoload.php')) {
    require_once __DIR__ . '/../vendor/autoload.php';
}
use OSS\Credentials\EnvironmentVariableCredentialsProvider;
use OSS\OssClient;
use OSS\Core\OssException;

// 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. 
$provider = new EnvironmentVariableCredentialsProvider();
// In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
$endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
// Specify the name of the bucket. 
$bucket= "yourBucketName";
// Set the ACL of the bucket to private. 
$acl = OssClient::OSS_ACL_TYPE_PRIVATE;
try {
    $config = array(
        "provider" => $provider,
        "endpoint" => $endpoint,
        "signatureVersion" => OssClient::OSS_SIGNATURE_VERSION_V4,
        "region"=> "cn-hangzhou"
    );
    $ossClient = new OssClient($config);

    $ossClient->putBucketAcl($bucket, $acl);
} catch (OssException $e) {
    printf(__FUNCTION__ . ": FAILED\n");
    printf($e->getMessage() . "\n");
    return;
}
print(__FUNCTION__ . ": OK" . "\n");
const OSS = require('ali-oss');

const client = new OSS({
  // 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 oss-cn-hangzhou. 
  region: '<Your region>',
  // 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. 
  accessKeyId: process.env.OSS_ACCESS_KEY_ID,
  accessKeySecret: process.env.OSS_ACCESS_KEY_SECRET,
  // Specify the name of the bucket. 
  bucket: 'yourBucketName',
});


async function putBucketACL() {
// Set the ACL of the bucket to private. 
  const acl = 'private'
  try {
    await client.putBucketACL('<Your Bucket Name>', acl)
  } catch (error) {
    console.log(error)
  }
}

putBucketACL()
# -*- coding: utf-8 -*-
import oss2
from oss2.credentials import EnvironmentVariableCredentialsProvider
# Obtain access credentials from the environment variables. Before you run the sample code, make sure that you have configured environment variables OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET. 
auth = oss2.ProviderAuthV4(EnvironmentVariableCredentialsProvider())

# 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. 
endpoint = "https://oss-cn-hangzhou.aliyuncs.com"

# Specify the ID of the region that maps to the endpoint. Example: cn-hangzhou. This parameter is required if you use the signature algorithm V4.
region = "cn-hangzhou"

# Specify the name of your bucket.
bucket = oss2.Bucket(auth, endpoint, "yourBucketName", region=region)

# Set the ACL of the bucket to private. 
bucket.put_bucket_acl(oss2.BUCKET_ACL_PRIVATE)
#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;

int main(void)
{
    /* Initialize information about the account that is used to access OSS. */
            
    /* 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. */
    std::string Endpoint = "yourEndpoint";
    /* 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. */
    std::string Region = "yourRegion";
    /* Specify the name of the bucket. Example: examplebucket. */
    std::string BucketName = "examplebucket";

    /* Initialize resources such as network resources. */
    InitializeSdk();

    ClientConfiguration conf;
    conf.signatureVersion = SignatureVersionType::V4;
    /* 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. */
    auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
    OssClient client(Endpoint, credentialsProvider, conf);
    client.SetRegion(Region);

    /* Set the ACL of the bucket to private. */
    SetBucketAclRequest request(BucketName, CannedAccessControlList::Private);
    auto outcome = client.SetBucketAcl(request);

    if (outcome.isSuccess()) {    
        std::cout << " setBucketAcl successfully " << std::endl;
    }
    else {
        /* Handle exceptions. */
        std::cout << "SetBucketAcl fail" <<
        ",code:" << outcome.error().Code() <<
        ",message:" << outcome.error().Message() <<
        ",requestId:" << outcome.error().RequestId() << std::endl;
        return -1;
    }

    /* Release resources such as network resources. */
    ShutdownSdk();
    return 0;
}
#include "oss_api.h"
#include "aos_http_io.h"
/* 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. */
const char *endpoint = "yourEndpoint";

/* Specify the name of the bucket. Example: examplebucket. */
const char *bucket_name = "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 char *region = "yourRegion";
void init_options(oss_request_options_t *options)
{

    options->config = oss_config_create(options->pool);
    /* Use a char* string to initialize data of the aos_string_t type. */
    aos_str_set(&options->config->endpoint, endpoint);
    /* 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. */    
    aos_str_set(&options->config->access_key_id, getenv("OSS_ACCESS_KEY_ID"));
    aos_str_set(&options->config->access_key_secret, getenv("OSS_ACCESS_KEY_SECRET"));
    // Specify two additional parameters.
    aos_str_set(&options->config->region, region);
    options->config->signature_version = 4;
    /* Specify whether to use CNAME to access OSS. The value 0 indicates that CNAME is not used. */
    options->config->is_cname = 0;
    /* Configure network parameters, such as the timeout period. */
    options->ctl = aos_http_controller_create(options->pool, 0);
}
int main(int argc, char *argv[])
{
    /* Call the aos_http_io_initialize method in main() to initialize global resources, such as network resources and memory resources. */
    if (aos_http_io_initialize(NULL, 0) != AOSE_OK) {
        exit(1);
    }
    /* Create a memory pool to manage memory. aos_pool_t is equivalent to apr_pool_t. The code used to create a memory pool is included in the APR library. */
    aos_pool_t *pool;
    /* Create a memory pool. The value of the second parameter is NULL. This value indicates that the pool does not inherit other memory pools. */
    aos_pool_create(&pool, NULL);
    /* Create and initialize options. This parameter includes global configuration information, such as endpoint, access_key_id, access_key_secret, is_cname, and curl. */
    oss_request_options_t *oss_client_options;
    /* Allocate the memory resources in the memory pool to the options. */
    oss_client_options = oss_request_options_create(pool);
    /* Initialize oss_client_options. */
    init_options(oss_client_options);
    /* Initialize the parameters. */
    aos_string_t bucket;
    aos_table_t *resp_headers = NULL; 
    aos_status_t *resp_status = NULL; 
    /* Assign char* data to a bucket of the aos_string_t type. */
    aos_str_set(&bucket, bucket_name);
    /* Set the ACL of the bucket to public-read (OSS_ACL_PUBLIC_READ). */
    resp_status = oss_put_bucket_acl(oss_client_options, &bucket, OSS_ACL_PUBLIC_READ, &resp_headers);
    if (aos_status_is_ok(resp_status)) {
        printf("set bucket acl succeeded\n");
    } else {
        printf("set bucket acl failed\n");
    }
    /* Release the memory pool. This operation releases the memory resources allocated for the request. */
    aos_pool_destroy(pool);
    /* Release the allocated global resources. */
    aos_http_io_deinitialize();
    return 0;
}
require 'aliyun/oss'

client = Aliyun::OSS::Client.new(
  # In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
  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. 
  access_key_id: ENV['OSS_ACCESS_KEY_ID'],
  access_key_secret: ENV['OSS_ACCESS_KEY_SECRET']
)
# Specify the name of the bucket. Example: examplebucket. 
bucket = client.get_bucket('examplebucket')
bucket.acl = Aliyun::OSS::ACL::PUBLIC_READ
puts bucket.acl
package main

import (
	"context"
	"flag"
	"log"

	"github.com/aliyun/alibabacloud-oss-go-sdk-v2/oss"
	"github.com/aliyun/alibabacloud-oss-go-sdk-v2/oss/credentials"
)

// Define global variables.
var (
	region     string // The region in which your bucket is located.
	bucketName string // The name of the bucket.
)

// Specify the init function used to initialize command line parameters.
func init() {
	flag.StringVar(&region, "region", "", "The region in which the bucket is located.")
	flag.StringVar(&bucketName, "bucket", "", "The name of the bucket.")
}

func main() {
	// Parse command line parameters.
	flag.Parse()

	// Check whether the name of the bucket is specified.
	if len(bucketName) == 0 {
		flag.PrintDefaults()
		log.Fatalf("invalid parameters, bucket name required")
	}

	// Check whether the region is specified.
	if len(region) == 0 {
		flag.PrintDefaults()
		log.Fatalf("invalid parameters, region required")
	}

	// Load the default configurations and specify the credential provider and region.
	cfg := oss.LoadDefaultConfig().
		WithCredentialsProvider(credentials.NewEnvironmentVariableCredentialsProvider()).
		WithRegion(region)

	// Create an OSS client.
	client := oss.NewClient(cfg)

	// Create a request to configure the ACL of the bucket.
	putRequest := &oss.PutBucketAclRequest{
		Bucket: oss.Ptr(bucketName),  // The name of the bucket.
		Acl:    oss.BucketACLPrivate, // Set the ACL to private.
	}

	// Perform the operation to configure the ACL.
	putResult, err := client.PutBucketAcl(context.TODO(), putRequest)
	if err != nil {
		log.Fatalf("failed to put bucket acl %v", err)
	}

	// Display the result.
	log.Printf("put bucket acl result: %#v\n", putResult)

	// Create a request to query the ACL.
	getRequest := &oss.GetBucketAclRequest{
		Bucket: oss.Ptr(bucketName), // The name of the bucket
	}

	// Perform the operation to query the ACL.
	getResult, err := client.GetBucketAcl(context.TODO(), getRequest)
	if err != nil {
		log.Fatalf("failed to get bucket acl %v", err)
	}

	// Display the result.
	log.Printf("get bucket acl result:%#v\n", getResult)
}

Use ossutil

You can use ossutil to configure the ACL of a bucket. For more information about how to install ossutil, see Install ossutil.

Run the following commands to set the ACL for the object to private.

ossutil api put-bucket-acl --bucket examplebucket --acl private

For more information, see put-bucket-acl.

Related API operation

The operations described above are fundamentally implemented based on the RESTful API, which you can directly call if your business requires a high level of customization. To directly call an API, you must include the signature calculation in your code. For more information, see PutBucketAcl.

FAQ

Are origin servers limited to public-read or public-read-write buckets for back-to-origin routing from Alibaba Cloud CDN to OSS?

No, origin servers are not limited to public-read or public-read-write buckets for back-to-origin routing from Alibaba Cloud CDN to OSS. You can also configure a private bucket as the origin server for back-to-origin routing from Alibaba Cloud CDN to OSS. For more information, see Configure access to private OSS buckets.

References

  • You can use bucket policies or RAM policies to grant users long-lived fine-grained permissions, such as the read-only or write-only permissions on objects whose names contain a specific prefix in a bucket. For more information, see Examples and Common examples of RAM policies.

  • You can use temporary access credentials provided by Security Token Service (STS) to grant users short-lived fine-grained permissions, such as the permissions to list all objects in a bucket. For more information, see Use temporary access credentials provided by STS to access OSS.

Previous: Block Public AccessNext: Object ACLs
  • On this page （1）
  • Usage notes
  • ACL types
  • Methods
  • Use the OSS console
  • Use ossbrowser
  • Use OSS SDKs
  • Use ossutil
  • Related API operation
  • FAQ
  • References
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