如何使用 Azure 存储模拟器 blob 端点获取 blob？

Question

以下代码在指向真实的 Azure 存储帐户时将成功返回 blob 内容：

var path = $"{container}/{blob}";
var rfcDate = DateTime.UtcNow.ToString("R");
var headers =  "GET\n\n\n\n\n\n\n\n\n\n\n\n" +
               "x-ms-blob-type:Block\n" +
              $"x-ms-date:{rfcDate}\n" + 
              $"x-ms-version:{ServiceVersion}\n" +
              $"/{AccountName}/{path}";
var uri = new Uri(BlobEndpoint + path);
var request = new HttpRequestMessage(HttpMethod.Get, uri);
request.Headers.Add("x-ms-blob-type", "Block");
request.Headers.Add("x-ms-date", rfcDate);
request.Headers.Add("x-ms-version", ServiceVersion);

string signature = "";
using (var sha = new HMACSHA256(System.Convert.FromBase64String(AccountKey)))
{
  var data = Encoding.UTF8.GetBytes(headers);
  signature = System.Convert.ToBase64String(sha.ComputeHash(data));
}

var authHeader = $"SharedKey {AccountName}:{signature}";
request.Headers.Add("Authorization", authHeader);

using (var client = new HttpClient())
{
  var response = await client.SendAsync(request);
  return await response.Content.ReadAsStringAsync();
}

但是，如果我将其配置为使用 Azure 模拟器：

• 帐户名 = devstoreaccount1
• AccountKey = Eby8vdM02xNOcqFlqUwJPLlmEtlCDXJ1OUzFT50uSRZ6IFsuFq2UVErCz4I6tq/K1SZFPTOtr/KBHBeksoGMGw==
• BlobEndpoint = http://127.0.0.1:10000/
• 服务版本 = 2009-09-19

我总是得到 404。我使用的是 Azure Storage Emulator v4.6。代码或配置不正确还是模拟器不支持？

Answer 1

您的代码有两个问题：

1. 存储模拟器中的 Blob 服务侦听 http://127.0.0.1:1000，但基本 URI 是 http://127.0.0.1:1000/devstoreaccount1。
2. 在计算Signature String（代码中的header 变量）时，帐户名必须出现两次。这是因为帐户名称是资源 URI 路径的一部分（blob 的 URL 为 http://127.0.0.1:1000/devstoreaccount1/container-name/blob-name）。

基于这些，请尝试以下代码：

    static async Task<string> ReadBlobFromDevStorage()
    {
        var container = "temp";
        var blob = "test.txt";
        var ServiceVersion = "2009-09-19";
        var AccountName = "devstoreaccount1";
        var BlobEndpoint = "http://127.0.0.1:10000/devstoreaccount1";
        var path = $"{container}/{blob}";
        var AccountKey = "Eby8vdM02xNOcqFlqUwJPLlmEtlCDXJ1OUzFT50uSRZ6IFsuFq2UVErCz4I6tq/K1SZFPTOtr/KBHBeksoGMGw==";
        var rfcDate = DateTime.UtcNow.ToString("R");
        var headers = "GET\n\n\n\n\n\n\n\n\n\n\n\n" +
                       "x-ms-blob-type:Block\n" +
                      $"x-ms-date:{rfcDate}\n" +
                      $"x-ms-version:{ServiceVersion}\n" +
                      $"/{AccountName}/{AccountName}/{path}";
        var uri = new Uri(BlobEndpoint + "/" + path);
        var request = new HttpRequestMessage(HttpMethod.Get, uri);
        request.Headers.Add("x-ms-blob-type", "Block");
        request.Headers.Add("x-ms-date", rfcDate);
        request.Headers.Add("x-ms-version", ServiceVersion);

        string signature = "";
        using (var sha = new HMACSHA256(System.Convert.FromBase64String(AccountKey)))
        {
            var data = Encoding.UTF8.GetBytes(headers);
            signature = System.Convert.ToBase64String(sha.ComputeHash(data));
        }

        var authHeader = $"SharedKey {AccountName}:{signature}";
        request.Headers.Add("Authorization", authHeader);

        using (var client = new HttpClient())
        {
            var response = await client.SendAsync(request);
            var content = await response.Content.ReadAsStringAsync();
            Console.WriteLine(content);
            return content;
        }
    }