Powershell http post REST API basic authentication


I have basic authentatication working with REST API using curl:

curl -X POST  -H 'Accept: application/json' -u user:password http://localhost/test/

But, when I try to do the same with powershell webRequest, I get 403(permission denied).
This script works fine when I disable authentication check in REST code.

What is the best way in powershell to pass credentials on POST request similar to curl or what can I do to fix following script.

Would really appreciate some guidance on this. Thanks.

Here is my powershell script:

function Execute-HTTPPostCommand() {
        [string] $target = $null

    $username = "user"
    $password = "pass"

    $webRequest = [System.Net.WebRequest]::Create($target)
    $webRequest.ContentType = "text/html"
    $PostStr = [System.Text.Encoding]::UTF8.GetBytes($Post)
    $webrequest.ContentLength = $PostStr.Length
    $webRequest.ServicePoint.Expect100Continue = $false
    $webRequest.Credentials = New-Object System.Net.NetworkCredential -ArgumentList $username, $password 

    $webRequest.PreAuthenticate = $true
    $webRequest.Method = "POST"

    $requestStream = $webRequest.GetRequestStream()
    $requestStream.Write($PostStr, 0,$PostStr.length)

    [System.Net.WebResponse] $resp = $webRequest.GetResponse();
    $rs = $resp.GetResponseStream();
    [System.IO.StreamReader] $sr = New-Object System.IO.StreamReader -argumentList $rs;
    [string] $results = $sr.ReadToEnd();

    return $results;


$post = "volume=6001F930010310000195000200000000&arrayendpoint=2000001F930010A4&hostendpoint=100000051ED4469C&lun=2"

$URL = "http://example.com/test/"

Execute-HTTPPostCommand $URL

Best Solution

I know this is an old thread, but for those who might stumble across this the invoke-restmethod is a much better, and simpler, vehicle for making API calls with PowerShell.

Build a parameter list as a hash table:

$params = @{uri = 'https:/api.trello.com/1/TheRestOfYourURIpath';
                   Method = 'Get'; #(or POST, or whatever)
                   Headers = @{Authorization = 'Basic ' + [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes("$($acctname):$($password)"));
           } #end headers hash table
   } #end $params hash table

$var = invoke-restmethod @params

Your parameter hash table may differ slightly.

I actually haven't gotten this to work with Trello, but I have with GitHub, Serena Business Manager and Jira.