Azure Service Bus Shared Access Signature Generation - azure

Question

I am trying to generate Shared Access signature for the Azure service bus queue. Here is the code snippnet through which I am generating SAS token.
using System;
using System.Globalization;
using System.Security.Cryptography;
using System.Text;
using System.Web;
namespace SASTokenGeneration
{
class Program
{
static void Main(string[] args)
{
string resourceUri = "sb://xxxservicequeue.servicebus.windows.net/;SharedAccessKeyName=xxxservicequeue;SharedAccessKey=xxxxxx";
string key = "token";
string keyName = "xxxservicequeue";
try
{
TimeSpan sinceEpoch = DateTime.UtcNow - new DateTime(1970, 1, 1);
var week = 60 * 60 * 24 * 7;
var expiry = Convert.ToString((int)sinceEpoch.TotalSeconds + week);
string stringToSign = HttpUtility.UrlEncode(resourceUri) + "\n" + expiry;
HMACSHA256 hmac = new HMACSHA256(Encoding.UTF8.GetBytes(key));
var signature = Convert.ToBase64String(hmac.ComputeHash(Encoding.UTF8.GetBytes(stringToSign)));
var sasToken = String.Format(CultureInfo.InvariantCulture, "SharedAccessSignature sr={0}&sig={1}&se={2}&skn={3}",
HttpUtility.UrlEncode(resourceUri), HttpUtility.UrlEncode(signature), expiry, keyName);
}
catch (Exception ex)
{
}
}
}
}
When I use this token in postman then sometime it gives
MalformedToken: Failed to parse simple web token. azure sevice Bus
and Now I am getting
401 40103: Invalid authorization token signature
From error, I know that I am doing something wrong with connection string but cannot figure out what. Can you please point me in right direction.
Thanks

Answer 1

Problems may locate at
string resourceUri = "sb://xxxservicequeue.servicebus.windows.net/;SharedAccessKeyName=xxxservicequeue;SharedAccessKey=xxxxxx";
string key = "token";
string keyName = "xxxservicequeue";
The resourceUri is the full URI of the Service Bus resource to which access is claimed, in the format of sb://xxxservicequeue.servicebus.windows.net/ or with specific entity you need to operate like sb://xxxservicequeue.servicebus.windows.net/queueName.
The key should be the value of SharedAccessKeyKey and keyName is SAS policy name like the default RootManageSharedAccessKey.
Have a look at doc for more details.