Question

我只为API REST编写了4种方法，但我需要的最后一种方法不起作用。这是删除消息队列。我有这段代码：

public static string DeleteMessage(String queueName, string account, byte[] key, string endpoint, string popreceipt,string messageid)
    {
        string requestMethod = "DELETE";

        String urlPath = String.Format("{0}/messages/{1}?popreceipt={2}", queueName,Uri.EscapeDataString(messageid),Uri.EscapeDataString(popreceipt));

        String storageServiceVersion = "2009-09-19";
        String dateInRfc1123Format = DateTime.UtcNow.ToString("R", CultureInfo.InvariantCulture);
        String canonicalizedHeaders = String.Format(
              "x-ms-date:{0}\nx-ms-version:{1}",
              dateInRfc1123Format,
              storageServiceVersion);
        String canonicalizedResource = String.Format("/{0}/{1}", account, urlPath);
        //String canonicalizedResource = String.Format("/{0}/{1}\npopreceipt:{2}", account, urlPath, popreceipt);
        String stringToSign = String.Format(
              "{0}\n\n\n\n\n\n\n\n\n\n\n\n{1}\n{2}",
              requestMethod,
              canonicalizedHeaders,
              canonicalizedResource);
        String authorizationHeader = CreateAuthorizationHeader(stringToSign, account, key);

        Uri uri = new Uri(endpoint + urlPath);
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
        request.Method = requestMethod;
        request.Headers.Add("x-ms-date", dateInRfc1123Format);
        request.Headers.Add("x-ms-version", storageServiceVersion);
        request.Headers.Add("Authorization", authorizationHeader);

        using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
        {
            Stream dataStream = response.GetResponseStream();

            return response.StatusCode.ToString();

        }
    }

    public static string GetMessage(String queueName,string account, byte[] key,string endpoint)
    {
        string requestMethod = "GET";

        String urlPath = String.Format("{0}/messages", queueName);

        String storageServiceVersion = "2009-09-19";
        String dateInRfc1123Format = DateTime.UtcNow.ToString("R", CultureInfo.InvariantCulture);
        String canonicalizedHeaders = String.Format(
              "x-ms-date:{0}\nx-ms-version:{1}",
              dateInRfc1123Format,
              storageServiceVersion );
        String canonicalizedResource = String.Format("/{0}/{1}", account, urlPath);
        String stringToSign = String.Format(
              "{0}\n\n\n\n\n\n\n\n\n\n\n\n{1}\n{2}",
              requestMethod,
              canonicalizedHeaders,
              canonicalizedResource);
        String authorizationHeader = CreateAuthorizationHeader(stringToSign,account,key);

        Uri uri = new Uri(endpoint + urlPath);
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
        request.Method = requestMethod;
        request.Headers.Add("x-ms-date", dateInRfc1123Format);
        request.Headers.Add("x-ms-version", storageServiceVersion );
        request.Headers.Add("Authorization", authorizationHeader);
        request.Accept = "application/atom+xml,application/xml";

        using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
        {
            Stream dataStream = response.GetResponseStream();
            using (StreamReader reader = new StreamReader(dataStream))
            {
                String responseFromServer = reader.ReadToEnd();

                return responseFromServer;
            }
        }
    }

GetMessage正常工作且DeleteMessage无效，CreateAuthorithation Headers Code为：

     private static String CreateAuthorizationHeader(String canonicalizedString, string account, byte[] key)
    {
        String signature = string.Empty;
        using (HMACSHA256 hmacSha256 = new HMACSHA256(key))
        {
            Byte[] dataToHmac = System.Text.Encoding.UTF8.GetBytes(canonicalizedString);
            signature = Convert.ToBase64String(hmacSha256.ComputeHash(dataToHmac));
        }

        String authorizationHeader = String.Format(
              CultureInfo.InvariantCulture,
              "{0} {1}:{2}",
              "SharedKey",
              account,
              signature);

        return authorizationHeader;
    }

我使用“Convert.FromBase64String（AccountSharedKey）”传递KEY，它适用于GetMessage（以及put消息的另一种方法），但这不适用于删除消息。

我在MSDN中看到API，DELETE和GET消息使用相同的参数，但查询字符串传递的参数除外。

解决

问题在于我不会将UriEscape用于Uri字符串中的参数，有时URL有效，有时不会。

Answer 1

我认为你构建“canonicalizedResource”字符串的方式存在问题。基于此处的文档：http://msdn.microsoft.com/en-us/library/windowsazure/dd179428.aspx（向下滚动到标题为“构造规范化资源字符串”的部分），您不应将Query String参数作为主规范化资源字符串的一部分传递。它们应该单独附上。

您能否看到使用以下作品：

            string canonicalizedResource = string.Format("/{0}/{1}/messages/{2}\npopreceipt:{3}", account, queueName, messageid, popreceipt);

希望这有帮助。

Answer 2

我尝试了以下代码，它对我来说很好。我创建了一个队列，插入一条消息做了一个“GET”消息就可以得到弹出收据然后删除了消息。我在代码中修改的东西只是基于我上面的答案的canonicalizedResource字符串：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Web;
using System.IO;
using System.Security.Cryptography;
using System.Globalization;

namespace ConsoleApplication15
{
    class Program
    {
        static void Main(string[] args)
        {
            string messageId = "<message id e.g. ba9bdbe6-cd10-465d-ab32-90756ea0471d>";
            string queueName = "<queue name e.g. abc>";
            string accountName = "<your account name>";
            string accountKey = "<you account key base64 encoded string>";
            string endpoint = "http://accountname.queue.core.windows.net/";
            string popreceipt = "<pop receipt e.g. AgAAAAEAAAAAAAAACuMLtGTIzQE=>";

            var result = DeleteMessage(queueName, accountName, Convert.FromBase64String(accountKey), endpoint,
                popreceipt, messageId);
        }

        public static string DeleteMessage(String queueName, string account, byte[] key, string endpoint, string popreceipt, string messageid)
        {
            string requestMethod = "DELETE";

            String urlPath = String.Format("{0}/messages/{1}?popreceipt={2}", queueName, Uri.EscapeDataString(messageid), Uri.EscapeDataString(popreceipt));

            String storageServiceVersion = "2009-09-19";
            String dateInRfc1123Format = DateTime.UtcNow.ToString("R", CultureInfo.InvariantCulture);
            String canonicalizedHeaders = String.Format(
                  "x-ms-date:{0}\nx-ms-version:{1}",
                  dateInRfc1123Format,
                  storageServiceVersion);
            String canonicalizedResource = string.Format("/{0}/{1}/messages/{2}\npopreceipt:{3}", account, queueName, messageid, popreceipt);
            String stringToSign = String.Format(
                  "{0}\n\n\n\n\n\n\n\n\n\n\n\n{1}\n{2}",
                  requestMethod,
                  canonicalizedHeaders,
                  canonicalizedResource);
            String authorizationHeader = CreateAuthorizationHeader(stringToSign, account, key);

            Uri uri = new Uri(endpoint + urlPath);
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
            request.Method = requestMethod;
            request.Headers.Add("x-ms-date", dateInRfc1123Format);
            request.Headers.Add("x-ms-version", storageServiceVersion);
            request.Headers.Add("Authorization", authorizationHeader);

            using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
            {
                Stream dataStream = response.GetResponseStream();

                return response.StatusCode.ToString();

            }
        }

        private static String CreateAuthorizationHeader(String canonicalizedString, string account, byte[] key)
        {
            String signature = string.Empty;
            using (HMACSHA256 hmacSha256 = new HMACSHA256(key))
            {
                Byte[] dataToHmac = System.Text.Encoding.UTF8.GetBytes(canonicalizedString);
                signature = Convert.ToBase64String(hmacSha256.ComputeHash(dataToHmac));
            }

            String authorizationHeader = String.Format(
                  CultureInfo.InvariantCulture,
                  "{0} {1}:{2}",
                  "SharedKey",
                  account,
                  signature);

            return authorizationHeader;
        }
    }
}

Azure Rest API从队列返回403删除消息（在其他方法中正常工作）

2 个答案: