使用 Powershell 从 Azure 存储中获取 blob，而不使用 Azure PowerShell 模块

Question

我已经尝试过this answer，但它适用于 Azure 表存储，我如何使用 Powershell 但不使用 Azure Powershell 模块从 Azure 存储中检索 blob？在documentation 中，它说我应该从

创建一个字符串

StringToSign = VERB + "\n" +  
           Content-MD5 + "\n" +  
           Content-Type + "\n" +  
           Date + "\n" +  
           CanonicalizedHeaders +   
           CanonicalizedResource;

但是当我将这些添加到前面提到的功能中时，它仍然不起作用，我做错了什么？

Answer 1

事实证明文档中有一个小错误，即使文档另有说明，您也需要在 CanonicalizedHeaders 之后换行。如果您仔细阅读文档中的下一个代码示例，他们实际上在那里有换行符：

PUT\n\ntext/plain; charset=UTF-8\n\nx-ms-date:Sun, 20 Sep 2009 20:36:40 GMT\nx-ms-meta-m1:v1\nx-ms-meta-m2:v2\n/testaccount1/mycontainer/hello.txt

无论如何，这是一个从 Azure Blob 存储中获取 Blob 的功能齐全的脚本：

function GenerateHeader(
    [string]$accountName,
    [string]$accountKey,
    [string]$verb,
    [string]$resource)
{
    $xmsversion = '2015-02-21'
    $xmsdate = Get-Date
    $xmsdate = $xmsdate.ToUniversalTime()
    $xmsdate = $xmsdate.toString('R')

    $newLine = "`n";

    $contentType = 'application/json'

    $headers = New-Object "System.Collections.Generic.Dictionary[[String],[String]]"
    $headers.Add("Content-Type", $contentType)
    $headers.Add("x-ms-date", $xmsdate)
    $headers.Add("x-ms-version", $xmsversion)

    $canonicalizedHeaders = "x-ms-date:$xmsdate"+$newLine+"x-ms-version:$xmsversion"
    $canonicalizedResource = $resource

    $stringToSign = $verb.ToUpper() + $newLine +`
                $contentMD5 + $newLine +`
                $contentType + $newLine +`
                $dateHeader + $newLine +`
                $canonicalizedHeaders + $newLine +`
                $canonicalizedResource;

    $hmacsha = New-Object System.Security.Cryptography.HMACSHA256
    $hmacsha.key = [Convert]::FromBase64String($accountKey)
    $signature = $hmacsha.ComputeHash([Text.Encoding]::UTF8.GetBytes($stringToSign))
    $signature = [Convert]::ToBase64String($signature)
    $headers.Add("Authorization", "SharedKeyLite " + $accountName + ":" + $signature)

    return $headers
}

$accountName = ''
$accountKey = ''
$container = ''
$fileName = ''

$blobUri = "https://$accountName.blob.core.windows.net/$container/$fileName"
$outputPath = "$PSScriptRoot\$fileName"
$headers = GenerateHeader $accountName $accountKey 'GET' "/$accountName/$container/$fileName"

$webClient = New-Object System.Net.WebClient

foreach ($key in $headers.Keys)
{
    $webClient.Headers.Add($key, $headers[$key])
}

$start_time = Get-Date
$webClient.DownloadFile($blobUri, $outputPath)
Write-Output "Time taken: $((Get-Date).Subtract($start_time).Seconds) second(s)"
Write-Output $stringToSign