在Azure Eventhub中发布数据时发生未经授权的错误

Question

我正在使用C#向Azure event hub发送数据。与Eventhub客户端不同，数据将通过http发布。根据需求，我创建了一个嵌入到http头中的SAStoken。但是当我发帖的时候得到501，未经授权的访问错误。不知道我哪里出了问题。下面是我写的代码

public static async Task<HttpResponseMessage> SendDataUsingHttp()
        {

            // Namespace info.
            var serviceNamespace = "myeventhubs";
            var hubName = "eventhub1";
            var url = string.Format("{0}/publishers/{1}/messages", hubName, 1);
            //var url = string.Format("{0}/messages", hubName);
            var baseUri = new 
             Uri(string.Format("https://{0}.servicebus.windows.net/" 
                          ,  serviceNamespace));
            var SharedAccessKeyName = "All";
            var SharedAccessKey = "<shared access key>";
            var sasToken = 
            createSasToken(baseUri.ToString(),SharedAccessKeyName, 
                           SharedAccessKey);
            var evtData = new
            {
                Temperature = new Random().Next(20, 50)
            };

            var payload = JsonConvert.SerializeObject(evtData);
            // Create client.
            var httpClient = new HttpClient
            {
                BaseAddress = baseUri
            };


            httpClient.DefaultRequestHeaders.Accept.Clear();
            httpClient.DefaultRequestHeaders.Authorization = new 

            System.Net.Http.Headers.AuthenticationHeaderValue   
             ("SharedAccessSignature", sasToken); 

           var content = new StringContent(payload, Encoding.UTF8);
           content.Headers.ContentType = new 
             System.Net.Http.Headers.MediaTypeHeaderValue("application/json");
            HttpResponseMessage result = null;
            try
            {
                result = await httpClient.PostAsync(url, content);
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex);
            }
            return result;
        }

         private static string createSasToken(string baseUri, string keyName, 
         string key)
        {
            TimeSpan sinceEpoch = DateTime.UtcNow - new DateTime(1970, 1, 1);
            var week = 60 * 60 * 24 * 7;
            var expiration = Convert.ToString((int)sinceEpoch.TotalSeconds + 
            week);
            string stringToSign = HttpUtility.UrlEncode(baseUri) + "\n" + 
            expiration;
            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(baseUri), HttpUtility.UrlEncode(signature), 
            expiration, keyName);
            return sasToken;
}

{statuscode:401，reasonprace:'unauthorization'，version:1.1，content:system.net.http.streamcontent，标头：{transfer-encoding:chunked strict-transport-security:microsoft-httpapi/2.0日期：Sun,2018年6月17日08:35:43 GMT server:microsoft-httpapi/2.0内容-类型：application/xml；charset=UTF-8
}}内容：{system.net.http.streamcontent}标头：{transfer-encoding:chunked

Answer 1

根据createSastoken方法，它将生成具有以下格式的授权标头值：

Authorization: SharedAccessSignature sr={0}&sig={1}&se={2}&skn={3}

对于请求，还可以指定以下代码：

System.Net.Http.Headers.AuthenticationHeaderValue("SharedAccessSignature", sasToken); 

使用Fiddler捕获网络跟踪，您会发现发送的请求中的授权头值如下所示：

Authorization: SharedAccessSignature SharedAccessSignature sr={0}&sig={1}&se={2}&skn={3}

对于您的代码，您需要在createsastoken方法下调整sastoken的格式。

此外，createsastoken方法的baseURI参数需要是您请求的完整请求路径。因此，您需要修改SendDatausInghttp下的相关代码以生成令牌，如下所示：

var sasToken =createSasToken(baseUri+url, SharedAccessKeyName, SharedAccessKey);