Flutter http_auth headers contain "carrier return" and "new line" characters (\r\n) - flutter

Question

I am currently experimenting with flutter and tried to use http package. When I request a resource, which requires an authorization header (Authorization: Basic ) I create my request as follows:
import 'package:http/http.dart' as http;
void request() {
http.get('http://<my_url>', headers: {'Authorization': 'Basic <hash>'}).then( (resp) {
print('response status: ${resp.statusCode} ${resp.reasonPhrase}');
}
}
While executing this request, I was watching the request sent over Wireshark and noticed, that it contains carrier-return (\r) and new-line (\n) characters at the end:
Snapshot of Wireshark
After invoking my request function, I get a 401 Unauthorized message in my print statement. When I invoke the same request in Postman, everything is fine.
I assume, that my authentication failed, because of these characters (\r\n) at the end of each header entry. Can anyone help me with it or am I doing something wrong?
PS.: I have also tried the http_auth package but it also failed.
import 'package:http_auth/http_auth.dart' as http_auth;
void request(String user, String password) {
http_auth.BasicAuthClient(user, password).get('http://<my_url>', headers: {'Authorization': 'Basic <hash>'}).then( (resp) {
print('response status: ${resp.statusCode} ${resp.reasonPhrase}');
}
}

Answer 1

Those \r\n characters are meant to be there. They are the line separators between the headers. If you packet capture the wire bytes from curl --user foo:bar www.dart.dev you will see exactly the same thing.
You will notice that Dart has lower-cased the header name to authorization as is perfectly valid per the RFC. However, this sometimes catches out some servers that (incorrectly) treat the header names case sensitively.
Try your postman again (or a curl with a manually-created, lower-case header) with authorization. If the server doesn't accept that, contact the server maintainer.