Download blob using PHP using shared access key

Question

I’m new to azure, I need to download a file from azure blob storage to local files using Share access key using php. I used below code to download but i’m getting invalid header.

$URL = "https://teststorage.blob.core.windows.net/$containerName/$blobName";

$Date = gmdate('D, d M Y H:i:s \G\M\T');

$headerResource = "x-ms-date:$Date\nx-ms-version:2017-11-09";

$urlResource = "/teststorage/$containerName/$blobName";

$arraysign = array();

$arraysign[] = 'GET';                          

$arraysign[] = $headerResource;     

$arraysign[] = $urlResource;     

$str2sign = implode("\n", $arraysign);

$sig = base64_encode(hash_hmac('sha256', urldecode(utf8_encode($str2sign)), base64_decode($accessKey), true));

$authHeader = "SharedKey teststorage:$sig";

$headers = [

    'Authorization: ' . $authHeader,

    'x-ms-date: ' . $Date,

    'x-ms-version: 2017-12-12',

];

Please help me with that provide me an answer.

I need to download file from azure blob storage using php.

Answer 1

I need to download a file from Azure blob storage to local files using the Share Access key using PHP. I used the below code to download but I’m getting an invalid header.

The error occurs maybe you were passing incorrect headers or invalid headers.

In my environment, I have a file name sample.png in the storage account.

Portal:

You can use the below code to download a file from Azure Blob storage to the local environment.

Code:

<?php

$storageAccountName = 'venkat123';
$accessKey = "xxxxxxxx";
$containerName = 'test';
$blobName = 'sample.png';

function downloadBlob($storageAccountName, $containerName, $blobName, $accessKey) {
    $URL = "https://$storageAccountName.blob.core.windows.net/$containerName/$blobName";

    $Date = gmdate('D, d M Y H:i:s \G\M\T');

    $headerResource = "x-ms-date:$Date\nx-ms-version:2019-12-12";
    $urlResource = "/$storageAccountName/$containerName/$blobName";

    $arraysign = array();
    $arraysign[] = 'GET';               /*HTTP Verb*/
    $arraysign[] = '';                  /*Content-Encoding*/
    $arraysign[] = '';                  /*Content-Language*/
    $arraysign[] = '';                  /*Content-Length (include value when zero)*/
    $arraysign[] = '';                  /*Content-MD5*/
    $arraysign[] = '';                  /*Content-Type*/
    $arraysign[] = '';                  /*Date*/
    $arraysign[] = '';                  /*If-Modified-Since */
    $arraysign[] = '';                  /*If-Match*/
    $arraysign[] = '';                  /*If-None-Match*/
    $arraysign[] = '';                  /*If-Unmodified-Since*/
    $arraysign[] = '';                  /*Range*/
    $arraysign[] = $headerResource;     /*CanonicalizedHeaders*/
    $arraysign[] = $urlResource;        /*CanonicalizedResource*/

    $str2sign = implode("\n", $arraysign);

    $sig = base64_encode(hash_hmac('sha256', urldecode(utf8_encode($str2sign)), base64_decode($accessKey), true));
    $authHeader = "SharedKey $storageAccountName:$sig";

    $headers = [
        'Authorization: ' . $authHeader,
        'x-ms-date: ' . $Date,
        'x-ms-version: 2019-12-12',
    ];

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $URL);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    $result = curl_exec($ch);

    if (curl_getinfo($ch, CURLINFO_HTTP_CODE) == 200) {
        file_put_contents('downloaded.png', $result);
        echo 'Downloaded successfully and saved as "downloaded.png".';
    } else {
        echo 'Download failed.';
    }

    curl_close($ch);
}

downloadBlob($storageAccountName, $containerName, $blobName, $accessKey);

Browser:

File:

Reference:

Get Blob (REST API) - Azure Storage | Microsoft Learn