aws_auth

A low-level library for signing AWS API requests in Dart.

Using

Create AWSCredentialsProvider object. In order to set credentials programatically, you can use AWSStaticCredentialsProvider class:

final credentialsProvider = AWSCredentialsProvider(
  'AWS_ACCESS_KEY_ID',
  'AWS_SECRET_ACCESS_KEY',
  sessionToken: 'AWS_SESSION_TOKEN',  // this is optional
);

You can implement your own provider e.g. if you need to dynamically retrieve the credentials and refresh them periodically.

Initialize AWS4Signer for the given region and service:

final signer = AWS4Signer(
  credentialsProvider, 
  region: 'eu-central-1', 
  serviceName:'sts',
);

Create AWSRequest object and pass it to sign or presign method of the signer (see examples below). Signer will modify request in place and add required headers or query parameters (in case of presigning) with authentication information.

POST request with an authorization header

final req = AWSRequest.formData(
  'https://sts.eu-central-1.amazonaws.com/',
  body: {
    'Action': 'GetCallerIdentity',
    'Version': '2011-06-15',
  },
);
signer.sign(req);

print(req.headers['Authorization'])
print(req.headers['X-Amz-Date'])

GET request with authentication information in the query string (presigned url)

final req = AWSRequest(
  'https://sts.eu-central-1.amazonaws.com/',
  queryParameters: {
    'Action': 'GetCallerIdentity',
    'Version': '2011-06-15',
  },
);
signer.presign(req);

print(req.url);