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我正在尝试访问存储在 Windows Azure 中的私有容器中的 blob。容器有一个共享访问签名，但是当我尝试访问 blob 时，我得到一个 StorgeClientException “服务器无法对请求进行身份验证。确保授权标头的格式正确，包括签名”。

创建容器并上传 blob 的代码如下所示：

// create the container, set a Shared Access Signature, and share it 

// first this to do is to create the connnection to the storage account
// this should be in app.config but as this isa test it will just be implemented
// here: 
// add a reference to Microsoft.WindowsAzure.StorageClient 
// and Microsoft.WindowsAzure.StorageClient set up the objects
//storageAccount = CloudStorageAccount.DevelopmentStorageAccount;

storageAccount = CloudStorageAccount.Parse(ConfigurationManager.AppSettings["ConnectionString"]);
blobClient = storageAccount.CreateCloudBlobClient();

// get a reference tot he container for the shared access signature
container = blobClient.GetContainerReference("blobcontainer");
container.CreateIfNotExist();

// now create the permissions policy to use and a public access setting
var permissions = container.GetPermissions();
permissions.SharedAccessPolicies.Remove("accesspolicy");
permissions.SharedAccessPolicies.Add("accesspolicy", new SharedAccessPolicy
                                                               {
                                                                   // this policy is live immediately
                                                                   // if the policy should be delatyed then use:
                                                                   //SharedAccessStartTime = DateTime.Now.Add(T); where T is some timespan
                                                                   SharedAccessExpiryTime =
                                                                       DateTime.UtcNow.AddYears(2),
                                                                   Permissions =
                                                                       SharedAccessPermissions.Read | SharedAccessPermissions.Write
                                                               });

// turn off public access
permissions.PublicAccess = BlobContainerPublicAccessType.Off;

// set the permission on the ocntianer
container.SetPermissions(permissions);

 var sas = container.GetSharedAccessSignature(new SharedAccessPolicy(), "accesspolicy");


StorageCredentialsSharedAccessSignature credentials = new StorageCredentialsSharedAccessSignature(sas);
CloudBlobClient client = new CloudBlobClient(storageAccount.BlobEndpoint,
                                             new StorageCredentialsSharedAccessSignature(sas));

CloudBlob sasblob = client.GetBlobReference("blobcontainer/someblob.txt");
sasblob.UploadText("I want to read this text via a rest call");

// write the SAS to file so I can use it later in other apps
using (var writer = new StreamWriter(@"C:\policy.txt"))
{
    writer.WriteLine(container.GetSharedAccessSignature(new SharedAccessPolicy(), "securedblobpolicy"));
}

我一直试图用来读取 blob 的代码如下所示：

// the storace credentials shared access signature is copied directly from the text file "c:\policy.txt"
CloudBlobClient client = new CloudBlobClient("https://my.azurestorage.windows.net/", new StorageCredentialsSharedAccessSignature("?sr=c&si=accesspolicy&sig=0PMoXpht2TF1Jr0uYPfUQnLaPMiXrqegmjYzeg69%2FCI%3D"));

CloudBlob blob = client.GetBlobReference("blobcontainer/someblob.txt");

Console.WriteLine(blob.DownloadText());
Console.ReadLine();

我可以通过添加帐户凭据来完成上述工作，但这正是我想要避免的。我不想要像我的帐户凭据那样敏感的东西只是坐在那里，而且我不知道如何在没有帐户凭据的情况下将签名导入客户端应用程序。

任何帮助是极大的赞赏。

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2 回答 2

4

为什么这个？

writer.WriteLine(container.GetSharedAccessSignature(new SharedAccessPolicy(), "securedblobpolicy"));

而不是写sas你已经创建的字符串？

已经很晚了，我很容易遗漏一些东西，但似乎您可能没有保存与最初用于写入文件的访问签名相同的访问签名。

在这里也可能不相关，但我相信您可以拥有的容器范围策略的数量是有限的。您是否使用此代码将多个文件上传到同一个容器并每次都创建一个新的容器 sas？

一般来说，我认为最好在需要时为单个 blob 请求 sas，并且到期时间很短。

于 2012-05-05T07:14:42.690 回答
1

“my.azurestorage.windows.net”只是一个错字吗？我希望那里有像“https://account.blob.core.windows.net”这样的东西。

否则，代码看起来与http://blog.smarx.com/posts/shared-access-signatures-are-easy-these-days中的代码非常相似，它可以工作。

于 2012-05-05T05:50:01.923 回答