Service Bus Send/Receive - REST API

Question

I need to use the Azure Service Bus REST API for sending messages to Service Bus Topics. On the receiving side I'm using the Azure Service Bus SDK.
Message on the sender side:
POST https://your-namespace.servicebus.windows.net/HttpClientSampleQueue/messages?timeout=60 HTTP/1.1
Authorization: SharedAccessSignature sr=your-namespace&sig=Fg8yUyR4MOmXfHfj55f5hY4jGb8x2Yc%2b3%2fULKZYxKZk%3d&se=1404256819&skn=RootManageSharedAccessKey
BrokerProperties: {"Label":"M1","State":"Active"}
Content-Type: application/atom+xml;type=entry;charset=utf-8
Host: your-namespace.servicebus.windows.net
This is a message.
When reading the message body as message.GetBody<string> an error message is given  serialization exception.
I already searched the web and found a possible solution:
Stream stream = message.GetBody<Stream>();
StreamReader reader = new StreamReader(stream);
string str = reader.ReadToEnd();
or as an alternative (instead of converting to string) converting the stream into an XmlDocument
Are hese recommended ways to handle this issue?
Thanks.

Answer 1

@Serkant & Paolo: Thanks for the answers.
The client I use is Postman (Chrome plug-in).
The message below works fine, but as I mentioned on the server side (.NET with Azure Service Bus SDK/API) until now I used:
Stream stream = message.GetBody<Stream>();
StreamReader reader = new StreamReader(stream);
string str = reader.ReadToEnd();
But I'll now try with 
var body = msg.GetBody<string>(new DataContractSerializer(typeof(string)));
POST /testtopic/messages HTTP/1.1
Host: namespace.servicebus.windows.net
Authorization: SharedAccessSignature sr=https%3a%2f%2namespace.servicebus.windows.net%2ftesttopic&sig=HUl2y3BTw%2bx3tSmUYZtpnfmzyxKfK1lqwIudfVY1UJg%3d&se=65025728850&skn=ManageAccessKey
Content-Type: application/atom+xml;type=entry;charset=utf-8
BrokerProperties: {"Label":"M1","State":"Active"}
MessageNumber: 1
Cache-Control: no-cache
Postman-Token: bf68bdef-2b5a-70ed-5fc3-96dbce720a7c
{"temp":40}