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Configure CORS on Bucket

Using this feature you can configure CORS on your bucket.

Components​

CORS Policies​

You can define a set of CORS policies as a list. Each of these policies can include the following keys:

  • AllowedHeaders
  • AllowedMethods (Mandatory)
  • AllowedOrigins (Mandatory)
  • ExposeHeaders
  • MaxAgeSeconds

For more information on how to enforce these policies, you can refer to the Managing CORS Settings documentation.

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX - License - Identifier: Apache - 2.0

namespace PutBucketCors
{
  using System;
  using System.Collections.Generic;
  using System.Threading.Tasks;
  using Amazon;
  using Amazon.S3;
  using Amazon.S3.Model;
  using System.Reflection;

  /// <summary>
  /// This example shows how to configure your bucket to allow cross-origin
  /// requests by creating a CORS configuration. This example was
  /// created using the AWS SDK for .NET 3.7 and .NET Core 5.0.
  /// </summary>
  public class PutBucketCors
  {
      // Remember to change the bucket name to the name of an Amazon Simple
      // Storage Service (Amazon S3) bucket that exists on your account.
      private const string BucketName = "<BUCKET_NAME>";

      /// <summary>
      /// The Main method creates the the bucket to be able to accept CORS
      /// requests.
      /// </summary>
      public static async Task Main()
      {
          var awsCredentials = new Amazon.Runtime.BasicAWSCredentials("<ACCESS-KEY>", "<SECRET-KEY>");
          var config = new AmazonS3Config { ServiceURL = "<ENDPOINT>" };
          var _s3Client = new AmazonS3Client(awsCredentials, config);

          CORSConfiguration configuration = new ()
          {
              Rules = new List<CORSRule>
              {
                  new CORSRule
                  {
                      Id = "CORSRule1",
                      AllowedMethods = new List<string> { "GET", "PUT", "POST", "DELETE" },
                      AllowedOrigins = new List<string> { "*" },
                      MaxAgeSeconds = 3000,
                      AllowedHeaders = new List<string> { "Authorization" },
                  },
              },
          };

          await PutCORSConfigurationAsync(_s3Client, configuration);
      }

      /// <summary>
      ///
      /// </summary>
      /// <param name="client"></param>
      /// <param name="configuration"></param>
      /// <returns></returns>
      private static async Task PutCORSConfigurationAsync(AmazonS3Client client, CORSConfiguration configuration)
      {
          try
          {
              PutCORSConfigurationRequest request = new ()
              {
                  BucketName = BucketName,
                  Configuration = configuration,
              };

              PutCORSConfigurationResponse response = await client.PutCORSConfigurationAsync(request);

              Console.WriteLine($"CORS configurations set on {BucketName} bucket");
          }
          catch (AmazonS3Exception amazonS3Exception)
          {
              Console.WriteLine("An AmazonS3Exception was thrown. Exception: " + amazonS3Exception.ToString());
          }
          catch (Exception e)
          {
              Console.WriteLine("Exception: " + e.ToString());
          }
      }
  }
}