putBucketCors method

Future<void> putBucketCors({ required String bucket, required CORSConfiguration cORSConfiguration, ChecksumAlgorithm? checksumAlgorithm, String? contentMD5, String? expectedBucketOwner, })

Sets the cors configuration for your bucket. If the configuration exists, Amazon S3 replaces it.

To use this operation, you must be allowed to perform the s3:PutBucketCORS action. By default, the bucket owner has this permission and can grant it to others.

You set this configuration on a bucket so that the bucket can service cross-origin requests. For example, you might want to enable a request whose origin is http://www.example.com to access your Amazon S3 bucket at my.example.bucket.com by using the browser's XMLHttpRequest capability.

To enable cross-origin resource sharing (CORS) on a bucket, you add the cors subresource to the bucket. The cors subresource is an XML document in which you configure rules that identify origins and the HTTP methods that can be executed on your bucket. The document is limited to 64 KB in size.

When Amazon S3 receives a cross-origin request (or a pre-flight OPTIONS request) against a bucket, it evaluates the cors configuration on the bucket and uses the first CORSRule rule that matches the incoming browser request to enable a cross-origin request. For a rule to match, the following conditions must be met:

• The request's Origin header must match AllowedOrigin elements.
• The request method (for example, GET, PUT, HEAD, and so on) or the Access-Control-Request-Method header in case of a pre-flight OPTIONS request must be one of the AllowedMethod elements.
• Every header specified in the Access-Control-Request-Headers request header of a pre-flight request must match an AllowedHeader element.

For more information about CORS, go to Enabling Cross-Origin Resource Sharing in the Amazon S3 User Guide.

The following operations are related to PutBucketCors:

• GetBucketCors
• DeleteBucketCors
• RESTOPTIONSobject

Parameter bucket : Specifies the bucket impacted by the corsconfiguration.

Parameter cORSConfiguration : Describes the cross-origin access configuration for objects in an Amazon S3 bucket. For more information, see Enabling Cross-Origin Resource Sharing in the Amazon S3 User Guide.

Parameter checksumAlgorithm : Indicates the algorithm used to create the checksum for the request when you use the SDK. This header will not provide any additional functionality if you don't use the SDK. When you send this header, there must be a corresponding x-amz-checksum or x-amz-trailer header sent. Otherwise, Amazon S3 fails the request with the HTTP status code 400 Bad Request. For more information, see Checking object integrity in the Amazon S3 User Guide.

If you provide an individual checksum, Amazon S3 ignores any provided ChecksumAlgorithm parameter.

Parameter contentMD5 : The Base64 encoded 128-bit MD5 digest of the data. This header must be used as a message integrity check to verify that the request body was not corrupted in transit. For more information, go to RFC 1864.

For requests made using the Amazon Web Services Command Line Interface (CLI) or Amazon Web Services SDKs, this field is calculated automatically.

Parameter expectedBucketOwner : The account ID of the expected bucket owner. If the account ID that you provide does not match the actual owner of the bucket, the request fails with the HTTP status code 403 Forbidden (access denied).

Implementation

Future<void> putBucketCors({
  required String bucket,
  required CORSConfiguration cORSConfiguration,
  ChecksumAlgorithm? checksumAlgorithm,
  String? contentMD5,
  String? expectedBucketOwner,
}) async {
  final headers = <String, String>{
    if (checksumAlgorithm != null)
      'x-amz-sdk-checksum-algorithm': checksumAlgorithm.value,
    if (contentMD5 != null) 'Content-MD5': contentMD5.toString(),
    if (expectedBucketOwner != null)
      'x-amz-expected-bucket-owner': expectedBucketOwner.toString(),
  };
  await _protocol.send(
    method: 'PUT',
    requestUri: '/${Uri.encodeComponent(bucket)}?cors',
    headers: headers,
    payload: cORSConfiguration.toXml('CORSConfiguration'),
    exceptionFnMap: _exceptionFns,
  );
}