【Azure 存储服务】代码版 Azure Storage Blob 生成 SAS (Shared Access Signature: 共享访问签名)

2022-10-31 18:23:59

问题描述

在使用Azure存储服务，为了有效的保护Storage的Access Keys。可以使用另一种授权方式访问资源(Shared Access Signature: 共享访问签名), 它的好处可以控制允许访问的IP，过期时间，权限和服务等。Azure门户上提供了对Account级，Container级，Blob级的SAS生成服务。

那么使用代码如何来生成呢？

问题回答

以最常见的两种代码作为示例：.NET 和 Java

.NET

Blob SAS 将使用帐户访问密钥(Storage Account Key1 or Key2)进行签名。使用 StorageSharedKeyCredential 类创建用于为 SAS 签名的凭据。新建 BlobSasBuilder 对象，并调用 ToSasQueryParameters 以获取 SAS 令牌字符串。官方文档（https://docs.azure.cn/zh-cn/storage/blobs/sas-service-create?tabs=dotnet）中进行了详细介绍，直接使用以下部分代码即可生成Blob的SAS URL。

private static Uri GetServiceSasUriForBlob(BlobClient blobClient,

    string storedPolicyName = null)

{

    // Check whether this BlobClient object has been authorized with Shared Key.

    if (blobClient.CanGenerateSasUri)

    {

        // Create a SAS token that's valid for one hour.

        BlobSasBuilder sasBuilder = new BlobSasBuilder()

        {

            BlobContainerName = blobClient.GetParentBlobContainerClient().Name,

            BlobName = blobClient.Name,

            Resource = "b"

        };

        if (storedPolicyName == null)

        {

            sasBuilder.ExpiresOn = DateTimeOffset.UtcNow.AddHours(1);

            sasBuilder.SetPermissions(BlobSasPermissions.Read |

                BlobSasPermissions.Write);

        }

        else

        {

            sasBuilder.Identifier = storedPolicyName;

        }

        Uri sasUri = blobClient.GenerateSasUri(sasBuilder);

        Console.WriteLine("SAS URI for blob is: {0}", sasUri);

        Console.WriteLine();

        return sasUri;

    }

    else

    {

        Console.WriteLine(@"BlobClient must be authorized with Shared Key

                          credentials to create a service SAS.");

        return null;

    }

}

JAVA

而Java的示例代码在官网中并没有介绍，所以本文就Java生成SAS的代码进行讲解。

从Java新版的SDK（azure-storage-blob）中，可以发现 BlobServiceClient，BlobContainerClient ，BlobClient 对象中都包含 generateAccountSas 或 generateSas 方法来实现对Account， Container，Blob进行SAS Token生成，只需要根据它所需要的参数对

AccountSasSignatureValues 和 BlobServiceSasSignatureValues 初始化。示例代码(全部代码可在文末下载)：

    public static void GenerateSASstring(BlobServiceClient blobServiceClient, BlobContainerClient blobContainerClient,

            BlobClient blobClient) {

        /*

         * Generate an account sas. Other samples in this file will demonstrate how to

         * create a client with the sas token.

         */

        // Configure the sas parameters. This is the minimal set.

        OffsetDateTime startTime = OffsetDateTime.now();

        OffsetDateTime expiryTime = OffsetDateTime.now().plusDays(1);

        AccountSasService services = new AccountSasService().setBlobAccess(true);

        AccountSasResourceType resourceTypes = new AccountSasResourceType().setObject(true);

        SasProtocol protocol = SasProtocol.HTTPS_ONLY;

        SasIpRange sasIpRange = SasIpRange.parse("167.220.255.73");

        // Generate the account sas.

        AccountSasPermission accountSasPermission = new AccountSasPermission().setReadPermission(true);

        AccountSasSignatureValues accountSasValues = new AccountSasSignatureValues(expiryTime, accountSasPermission,

                services, resourceTypes);

        accountSasValues.setStartTime(startTime);

        accountSasValues.setProtocol(protocol);

        accountSasValues.setSasIpRange(sasIpRange);

        String accountSasToken = blobServiceClient.generateAccountSas(accountSasValues);

        System.out.println("\nGenerate the account sas & url is :::: \n\t" + accountSasToken + "\n\t"

                + blobServiceClient.getAccountUrl() + "?" + accountSasToken);

        // Generate a sas using a container client

        BlobContainerSasPermission containerSasPermission = new BlobContainerSasPermission().setCreatePermission(true);

        BlobServiceSasSignatureValues serviceSasValues = new BlobServiceSasSignatureValues(expiryTime,

                containerSasPermission);

        serviceSasValues.setStartTime(startTime);

        serviceSasValues.setProtocol(protocol);

        serviceSasValues.setSasIpRange(sasIpRange);

        String containerSasToken = blobContainerClient.generateSas(serviceSasValues);

        System.out.println("\nGenerate the Container sas & url is :::: \n\t" + containerSasToken + "\n\t"

                + blobContainerClient.getBlobContainerUrl() + "?" + containerSasToken);

        // Generate a sas using a blob client

        BlobSasPermission blobSasPermission = new BlobSasPermission().setReadPermission(true);

        serviceSasValues = new BlobServiceSasSignatureValues(expiryTime, blobSasPermission);

        serviceSasValues.setStartTime(startTime);

        serviceSasValues.setProtocol(protocol);

        serviceSasValues.setSasIpRange(sasIpRange);

        String blobSasToken = blobClient.generateSas(serviceSasValues);

        System.out.println("\nGenerate the Blob sas & url is :::: \n\t" + blobSasToken + "\n\t"

                + blobClient.getBlobUrl() + "?" + blobSasToken);

    }

在pom.xml 中所需要加载的依赖项：

    <dependency>

      <groupId>com.azure</groupId>

      <artifactId>azure-storage-blob</artifactId>

      <version>12.13.0</version>

    </dependency>

以上代码中的各部分设置项与 Azure门户上设置项的对应关系如下图：

【Azure 存储服务】代码版 Azure Storage Blob 生成 SAS (Shared Access Signature: 共享访问签名)

运行效果图

【Azure 存储服务】代码版 Azure Storage Blob 生成 SAS (Shared Access Signature: 共享访问签名)

附录一：Java Main函数全部代码：

package test;

import java.io.File;

import java.io.FileWriter;

import java.io.IOException;

import java.net.URISyntaxException;

import java.security.InvalidKeyException;

import java.time.OffsetDateTime;

import java.util.Iterator;

import com.azure.storage.blob.BlobClient;

import com.azure.storage.blob.BlobContainerClient;

import com.azure.storage.blob.BlobServiceClient;

import com.azure.storage.blob.BlobServiceClientBuilder;

import com.azure.storage.blob.models.BlobItem;

import com.azure.storage.blob.sas.BlobContainerSasPermission;

import com.azure.storage.blob.sas.BlobSasPermission;

import com.azure.storage.blob.sas.BlobServiceSasSignatureValues;

import com.azure.storage.common.sas.AccountSasPermission;

import com.azure.storage.common.sas.AccountSasResourceType;

import com.azure.storage.common.sas.AccountSasService;

import com.azure.storage.common.sas.AccountSasSignatureValues;

import com.azure.storage.common.sas.SasIpRange;

import com.azure.storage.common.sas.SasProtocol;

/**

 * Hello world!

 *

 */

public class App {

    public static void main(String[] args)

            throws URISyntaxException, InvalidKeyException, RuntimeException, IOException {

        System.out.println("Hello World!");

        String storageConnectionString = "DefaultEndpointsProtocol=https;AccountName=<your storage account name>;AccountKey=**************************;EndpointSuffix=core.chinacloudapi.cn";

        String blobContainerName = "test";

        String dirName = "";

        // Create a BlobServiceClient object which will be used to create a container

        System.out.println("\nCreate a BlobServiceClient Object to Connect Storage Account");

        BlobServiceClient blobServiceClient = new BlobServiceClientBuilder().connectionString(storageConnectionString)

                .buildClient();

        // Create a unique name for the container

        String containerName = blobContainerName + java.util.UUID.randomUUID();

        // Create the container and return a container client object

        System.out.println("\nCreate new Container : " + containerName);

        BlobContainerClient containerClient = blobServiceClient.createBlobContainer(containerName);

        // Create a local file in the ./data/ directory for uploading and downloading

        System.out.println("\nCreate a local file in the ./data/ directory for uploading and downloading");

        String localPath = "./data/";

        String fileName = "quickstart" + java.util.UUID.randomUUID() + ".txt";

        File localFile = new File(localPath + fileName);

        // Write text to the file

        FileWriter writer = new FileWriter(localPath + fileName, true);

        writer.write("Hello, World! This is test file to download by SAS. Also test upload");

        writer.close();

        // Get a reference to a blob

        BlobClient blobClient = containerClient.getBlobClient(fileName);

        System.out.println("\nUploading to Blob storage as blob:\n\t" + blobClient.getBlobUrl());

        // Upload the blob

        blobClient.uploadFromFile(localPath + fileName);

        System.out.println("\nUpload blob completed : " + blobClient.getBlobName());

        System.out.println("\nListing blobs...");

        // List the blob(s) in the container.

        for (BlobItem blobItem : containerClient.listBlobs()) {

            System.out.println("\t" + blobItem.getName());

        }

        // Download the blob to a local file

        // Append the string "DOWNLOAD" before the .txt extension so that you can see

        // both files.

        String downloadFileName = fileName.replace(".txt", "DOWNLOAD.txt");

        File downloadedFile = new File(localPath + downloadFileName);

        System.out.println("\nDownloading blob to\n\t " + localPath + downloadFileName);

        blobClient.downloadToFile(localPath + downloadFileName);

        // Generate SAS String for blob user..

        System.out.println("\nGenerate SAS String for blob user..");

        GenerateSASstring(blobServiceClient, containerClient, blobClient);

        // Clean up

        System.out.println("\nPress the Enter word 'Delete' to begin clean up");

        boolean isDelete = System.console().readLine().toLowerCase().trim().equals("delete");

        if (isDelete) {

            System.out.println("Deleting blob container...");

            containerClient.delete();

            System.out.println("Deleting the local source and downloaded files...");

            localFile.delete();

            downloadedFile.delete();

        } else {

            System.out.println("Skip to Clean up operation");

        }

        System.out.println("Done");

    }

    public static void GenerateSASstring(BlobServiceClient blobServiceClient, BlobContainerClient blobContainerClient,

            BlobClient blobClient) {

        /*

         * Generate an account sas. Other samples in this file will demonstrate how to

         * create a client with the sas token.

         */

        // Configure the sas parameters. This is the minimal set.

        OffsetDateTime startTime = OffsetDateTime.now();

        OffsetDateTime expiryTime = OffsetDateTime.now().plusDays(1);

        AccountSasService services = new AccountSasService().setBlobAccess(true);

        AccountSasResourceType resourceTypes = new AccountSasResourceType().setObject(true);

        SasProtocol protocol = SasProtocol.HTTPS_ONLY;

        SasIpRange sasIpRange = SasIpRange.parse("167.220.255.73");

        // Generate the account sas.

        AccountSasPermission accountSasPermission = new AccountSasPermission().setReadPermission(true);

        AccountSasSignatureValues accountSasValues = new AccountSasSignatureValues(expiryTime, accountSasPermission,

                services, resourceTypes);

        accountSasValues.setStartTime(startTime);

        accountSasValues.setProtocol(protocol);

        accountSasValues.setSasIpRange(sasIpRange);

        String accountSasToken = blobServiceClient.generateAccountSas(accountSasValues);

        System.out.println("\nGenerate the account sas & url is :::: \n\t" + accountSasToken + "\n\t"

                + blobServiceClient.getAccountUrl() + "?" + accountSasToken);

        // Generate a sas using a container client

        BlobContainerSasPermission containerSasPermission = new BlobContainerSasPermission().setCreatePermission(true);

        BlobServiceSasSignatureValues serviceSasValues = new BlobServiceSasSignatureValues(expiryTime,

                containerSasPermission);

        serviceSasValues.setStartTime(startTime);

        serviceSasValues.setProtocol(protocol);

        serviceSasValues.setSasIpRange(sasIpRange);

        String containerSasToken = blobContainerClient.generateSas(serviceSasValues);

        System.out.println("\nGenerate the Container sas & url is :::: \n\t" + containerSasToken + "\n\t"

                + blobContainerClient.getBlobContainerUrl() + "?" + containerSasToken);

        // Generate a sas using a blob client

        BlobSasPermission blobSasPermission = new BlobSasPermission().setReadPermission(true);

        serviceSasValues = new BlobServiceSasSignatureValues(expiryTime, blobSasPermission);

        serviceSasValues.setStartTime(startTime);

        serviceSasValues.setProtocol(protocol);

        serviceSasValues.setSasIpRange(sasIpRange);

        String blobSasToken = blobClient.generateSas(serviceSasValues);

        System.out.println("\nGenerate the Blob sas & url is :::: \n\t" + blobSasToken + "\n\t"

                + blobClient.getBlobUrl() + "?" + blobSasToken);

    }

}

参考资料

快速入门：使用 Java v12 SDK 管理 blob：https://docs.azure.cn/zh-cn/storage/blobs/storage-quickstart-blobs-java

Azure Storage Blob client library for Java：https://github.com/Azure/azure-sdk-for-java/tree/main/sdk/storage/azure-storage-blob#generate-a-sas-token

示例下载：

码农公寓

问题描述

问题回答

.NET

JAVA

运行效果图

附录一：Java Main函数全部代码：

参考资料

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