适用于 PHP 的 Microsoft Azure 和 SAS

Question

我尝试使用 PHP 创建指向 blob 资源的 SAS 链接。不幸的是，目前在 azure SDK 中没有创建 SAS 签名的方法。 我编写了用于生成 SAS 的代码，但是当我尝试通过此方法生成的链接获取资源时，我收到以下消息：签名字段格式不正确。

    public function getSharedAccessSignatureURL($container, $blob)
{
    $signedStart = date('c', strtotime('-1 day'));
    $signedExpiry = date('c', strtotime('+1 day'));
    $signedResource = 'b';
    $signedPermission = 'r';
    $signedIdentifier = '';
    $responseContent = "file; attachment";
    $responseType = "binary";

    $canonicalizedResource = '/'.$this->account['accountName'].'/'.$container.'/'.$blob;
    $signedVersion = '2014-02-14';

    $stringToSign =
        $signedPermission."\n".
        $signedStart."\n".
        $signedExpiry."\n".
        $canonicalizedResource."\n".
        $signedIdentifier."\n".
        $signedVersion;

    $signature = base64_encode(
        hash_hmac(
            'sha256',
            urldecode(utf8_encode($stringToSign)),
            $this->account['primaryKey'],
            true
        )
    );

    $arrayToUrl = [
        'sv='.urlencode($signedVersion),
        'st='.urlencode($signedStart),
        'se='.urlencode($signedExpiry),
        'sr='.urlencode($signedResource),
        'sp='.urlencode($signedPermission),
        'rscd='.urlencode($responseContent),
        'rsct='.urlencode($responseType),
        'sig='.urlencode($signature)
    ];

    $url =  'https://'.$this->account['accountName'].'.blob.core.windows.net'.'/'
        .$container.'/'
        .$blob.'?'.implode('&', $arrayToUrl);

    return $url;
}

任何建议我做错了什么？我是 Microsoft Azure 的新手

Answer 1

我认为您的 $stringToSign 变量存在问题。根据此处的文档：http://msdn.microsoft.com/en-US/library/azure/dn140255.aspx，您要签名的字符串应构造如下：

StringToSign = signedpermissions + "\n"
               signedstart + "\n"
               signedexpiry + "\n"
               canonicalizedresource + "\n"
               signedidentifier + "\n"
               signedversion + "\n"
               rscc + "\n"
               rscd + "\n"
               rsce + "\n"
               rscl + "\n"
               rsct

考虑到您在 SAS 查询字符串中包含 rscd 和 rsct。请尝试以下方法，看看是否有所不同：

    $stringToSign =
            $signedPermission."\n".
            $signedStart."\n".
            $signedExpiry."\n".
            $canonicalizedResource."\n".
            $signedIdentifier."\n".
            $signedVersion."\n".
            "\n".
            $responseContent."\n".
            "\n".
            "\n".
            $responseType;

更新

请尝试以下代码。将帐户名称/密钥、容器名称和 blob 名称替换为适当的值：

<?php
$signedStart = gmdate('Y-m-d\TH:i:s\Z', strtotime('-1 day'));
echo $signedStart."\n";
$signedExpiry = gmdate('Y-m-d\TH:i:s\Z', strtotime('+1 day'));
echo $signedExpiry."\n";
$signedResource = 'b';
$signedPermission = 'r';
$signedIdentifier = '';
$accountName = "[account name]";
$accountKey = "[account key]";
$container = "[container name]";
$blob = "[blob name]";
$canonicalizedResource = '/'.$accountName.'/'.$container.'/'.$blob;
$signedVersion = '2014-02-14';  
echo $canonicalizedResource."\n";
$rscc = '';
$rscd = 'file; attachment';//Content disposition
$rsce = '';
$rscl = '';
$rsct = 'binary';//Content type
$stringToSign = 
                $signedPermission."\n".
                $signedStart."\n".
                $signedExpiry."\n".
                $canonicalizedResource."\n".
                $signedIdentifier."\n".
                $signedVersion."\n".
                $rscc."\n".
                $rscd."\n".
                $rsce."\n".
                $rscl."\n".
                $rsct;


echo $stringToSign."\n";

$signature = base64_encode(
        hash_hmac(
            'sha256',
            $stringToSign,
            base64_decode($accountKey),
            true
        )
    );

echo $signature."\n";


$arrayToUrl = [
        'sv='.urlencode($signedVersion),
        'st='.urlencode($signedStart),
        'se='.urlencode($signedExpiry),
        'sr='.urlencode($signedResource),
        'sp='.urlencode($signedPermission),
        'rscd='.urlencode($rscd),
        'rsct='.urlencode($rsct),
        'sig='.urlencode($signature)
    ];

    $url =  'https://'.$accountName.'.blob.core.windows.net'.'/'
        .$container.'/'
        .$blob.'?'.implode('&', $arrayToUrl);

echo $url."\n";
?>

基本上有两个问题（除了不正确的$stringToSign变量）：

1. 开始/结束日期时间格式不正确。
2. 我们需要base64_decode 计算签名的帐户密钥。

Answer 2

我遇到了完全相同的问题。但是现在您可以使用MicrosoftAzure\Storage\Common\SharedAccessSignatureHelper，它可以为您解决很多问题。 2 年前，我已在此 PR (https://github.com/Azure/azure-storage-php/pull/73/files) 中添加到公共库。

它应该像这样非常简单地解决：

$sasHelper = new SharedAccessSignatureHelper(
    'nameofyouraccount',
    'H...your-token...=='
);

$sas = $sasHelper->generateAccountSharedAccessSignatureToken(
    '2018-11-09',
    'rwl',
    'b',
    'sco',
    (new \DateTime())->modify('+10 minute'),
    (new \DateTime())->modify('-5 minute'),
    '',
    'https'
);

$connectionString = "BlobEndpoint=https://nameofyouraccount.blob.core.windows.net/;SharedAccessSignature={$sas}";

你得到了你的连接字符串！

Answer 3

从@Gaurav Mantri 修改并变成一个函数

function generateSasToken($bucket,$key, $accountName, $accountKey){

    $signedStart = gmdate('Y-m-d\TH:i:s\Z', time());
    $signedExpiry = gmdate('Y-m-d\TH:i:s\Z', time()+3600);
    $signedResource = 'b';
    $signedPermission = 'r';
    $signedIdentifier = '';
    $canonicalizedResource = '/' . $accountName . '/' . $bucket . '/' . $key;
    $signedVersion = '2014-02-14';
    $rscc = '';
    $rscd = 'file; attachment';//Content disposition
    $rsce = '';
    $rscl = '';
    $rsct = 'binary';//Content type

    $stringToSign =
        $signedPermission . "\n" .
        $signedStart . "\n" .
        $signedExpiry . "\n" .
        $canonicalizedResource . "\n" .
        $signedIdentifier . "\n" .
        $signedVersion . "\n" .
        $rscc . "\n" .
        $rscd . "\n" .
        $rsce . "\n" .
        $rscl . "\n" .
        $rsct;

    $signature = base64_encode(
        hash_hmac(
            'sha256',
            $stringToSign,
            base64_decode($accountKey),
            true
        )
    );

   $arrayToUrl = [
        'sv=' . urlencode($signedVersion),
        'st=' . urlencode($signedStart),
        'se=' . urlencode($signedExpiry),
        'sr=' . urlencode($signedResource),
        'sp=' . urlencode($signedPermission),
        'rscd=' . urlencode($rscd),
        'rsct=' . urlencode($rsct),
        'sig=' . urlencode($signature)
    ];

    $url = 'https://' . $accountName . '.blob.core.windows.net' . '/'
        . $bucket . '/'
        . $key . '?' . implode('&', $arrayToUrl);

    return $url;
}