putBucketCors method

Future<void> putBucketCors({ required String bucket, required CORSConfiguration cORSConfiguration, 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 Simple Storage Service Developer Guide.

Related Resources

• 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 Simple Storage Service Developer Guide.

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 AWS Command Line Interface (CLI) or AWS SDKs, this field is calculated automatically.

Parameter expectedBucketOwner : The account id of the expected bucket owner. If the bucket is owned by a different account, the request will fail with an HTTP 403 (Access Denied) error.

Implementation

Future<void> putBucketCors({
  required String bucket,
  required CORSConfiguration cORSConfiguration,
  String? contentMD5,
  String? expectedBucketOwner,
}) async {
  ArgumentError.checkNotNull(bucket, 'bucket');
  ArgumentError.checkNotNull(cORSConfiguration, 'cORSConfiguration');
  final headers = <String, String>{
    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,
  );
}