getCanonicalHeaders method

String getCanonicalHeaders()

Returns canonical headers

See: https://docs.aws.amazon.com/general/latest/gr/sigv4-create-canonical-request.html

Implementation

String getCanonicalHeaders() {
  var result = <String>[];

  var canonicalHeadersMap = headers
      .map((key, value) => MapEntry(key.toLowerCase(), trimAll(value)));
  var sortedKeys = canonicalHeadersMap.keys.toList()..sort();
  for (var key in sortedKeys) {
    var value = canonicalHeadersMap[key];
    result.add('$key:$value\n');
  }

  return result.join();
}