MAC Signature Not Same Error While Accessing Storage REST API - azure

Question

I trying to call the storage REST API using powershell but facing errors. PFB details-
Script
$version = "2017-04-17"
$storageAccount = "{storageAccountName}"
$accesskey= “{storageAccountAccessKey}"
$resource = "?comp=list"
$storage_url = "https://$storageAccount.blob.core.windows.net/$resource"
$GMTTime = (Get-Date).ToUniversalTime().toString('R')
$stringToSign = "GET`nx-ms-date:$GMTTime`nx-ms-version:2017-04-17`n/$storageAccount/$resource"
$hmacsha = New-Object System.Security.Cryptography.HMACSHA256
$hmacsha.key = [Convert]::FromBase64String($accesskey)
$signature = $hmacsha.ComputeHash([Text.Encoding]::UTF8.GetBytes($stringToSign))
$signature = [Convert]::ToBase64String($signature)
$headers = #{
'x-ms-date' = $GMTTime
'Authorization' = "SharedKeyLite " + $storageAccount + ":" + $signature
'x-ms-version' = $version
}
Invoke-RestMethod -Method GET -Uri $storage_url -Headers $headers
Error Message
Invoke-RestMethod : AuthenticationFailedServer failed to authenticate the request. Make sure the value of Authorization header is formed correctly including the
signature.
RequestId:ee5459f7-501e-004b-0426-46de36000000
Time:2020-06-19T10:45:36.7846714ZThe MAC signature found in the HTTP request <signature>' is not the same as any computed signature.
Server used following string to sign: 'GET
x-ms-date:Fri, 19 Jun 2020 10:37:00 GMT
x-ms-version:2017-04-17
/<storageAccount>/?comp=list'.
Can someone please help me understand what is missing here.
Documentation being followed for authorization- https://learn.microsoft.com/en-us/rest/api/storageservices/authorize-with-shared-key

Answer 1

Please use the following code:
$version = "2017-04-17"
$storageAccount = "{storageAccountName}"
$accesskey= “{storageAccountAccessKey}"
$resource = "?comp=list"
$storage_url = "https://$storageAccount.blob.core.windows.net/$resource"
$GMTTime = (Get-Date).ToUniversalTime().toString('R')
$ContentMd5 = ""
$ContentType = ""
$CanonicalizedHeaders = "x-ms-date:$GMTTime`nx-ms-version:$version`n"
$CanonicalizedResource = "/$storageAccount/$resource"
$stringToSign = "GET`n$ContentMd5`n$ContentType`n`n$CanonicalizedHeaders$CanonicalizedResource"
$hmacsha = New-Object System.Security.Cryptography.HMACSHA256
$hmacsha.key = [Convert]::FromBase64String($accesskey)
$signature = $hmacsha.ComputeHash([Text.Encoding]::UTF8.GetBytes($stringToSign))
$signature = [Convert]::ToBase64String($signature)
$headers = #{
'x-ms-date' = $GMTTime
'Authorization' = "SharedKeyLite " + $storageAccount + ":" + $signature
'x-ms-version' = $version
}
Invoke-RestMethod -Method GET -Uri $storage_url -Headers $headers