[powershell] Use Invoke-WebRequest with a username and password for basic authentication on the GitHub API

With cURL, we can pass a username with an HTTP web request as follows:

$ curl -u <your_username> https://api.github.com/user

The -u flag accepts a username for authentication, and then cURL will request the password. The cURL example is for Basic authentication with the GitHub Api.

How do we similarly pass a username and password along with Invoke-WebRequest? The ultimate goal is to user PowerShell with Basic authentication in the GitHub API.

This is what worked for our particular situation.

Notes are from Wikipedia on Basic Auth from the Client Side. Thank you to @briantist's answer for the help!

Combine the username and password into a single string username:password

$user = "shaunluttin"
$pass = "super-strong-alpha-numeric-symbolic-long-password"
$pair = "${user}:${pass}"

Encode the string to the RFC2045-MIME variant of Base64, except not limited to 76 char/line.

$bytes = [System.Text.Encoding]::ASCII.GetBytes($pair)
$base64 = [System.Convert]::ToBase64String($bytes)

Create the Auth value as the method, a space, and then the encoded pair Method Base64String

$basicAuthValue = "Basic $base64"

Create the header Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==

$headers = @{ Authorization = $basicAuthValue }

Invoke the web-request

Invoke-WebRequest -uri "https://api.github.com/user" -Headers $headers

The PowerShell version of this is more verbose than the cURL version is. Why is that? @briantist pointed out that GitHub is breaking the RFC and PowerShell is sticking to it. Does that mean that cURL is also breaking with the standard?

Invoke-WebRequest follows the RFC2617 as @briantist noted, however there are some systems (e.g. JFrog Artifactory) that allow anonymous usage if the Authorization header is absent, but will respond with 401 Forbidden if the header contains invalid credentials.

This can be used to trigger the 401 Forbidden response and get -Credentials to work.

$login = Get-Credential -Message "Enter Credentials for Artifactory"

                              #Basic foo:bar
$headers = @{ Authorization = "Basic Zm9vOmJhcg==" }  

Invoke-WebRequest -Credential $login -Headers $headers -Uri "..."

This will send the invalid header the first time, which will be replaced with the valid credentials in the second request since -Credentials overrides the Authorization header.

Tested with Powershell 5.1

I had to do this to get it to work:

$pair = "$($user):$($pass)"
$encodedCredentials = [System.Convert]::ToBase64String([System.Text.Encoding]::ASCII.GetBytes($Pair))
$headers = @{ Authorization = "Basic $encodedCredentials" }
Invoke-WebRequest -Uri $url -Method Get -Headers $headers -OutFile Config.html

another way is to use certutil.exe save your username and password in a file e.g. in.txt as username:password

certutil -encode in.txt out.txt

Now you should be able to use auth value from out.txt

$headers = @{ Authorization = "Basic $((get-content out.txt)[1])" }
Invoke-WebRequest -Uri 'https://whatever' -Headers $Headers

Here is another way using WebRequest, I hope it will work for you

$user = 'whatever'
$pass = 'whatever'
$secpasswd = ConvertTo-SecureString $pass -AsPlainText -Force
$credential = New-Object System.Management.Automation.PSCredential($user, $secpasswd)
$headers = @{ Authorization = "Basic Zm9vOmJhcg==" }  
Invoke-WebRequest -Credential $credential -Headers $headers -Uri "https://dc01.test.local/"

I know this is a little off the OPs original request but I came across this while looking for a way to use Invoke-WebRequest against a site requiring basic authentication.

The difference is, I did not want to record the password in the script. Instead, I wanted to prompt the script runner for credentials for the site.

Here's how I handled it

$creds = Get-Credential

$basicCreds = [pscredential]::new($Creds.UserName,$Creds.Password)

Invoke-WebRequest -Uri $URL -Credential $basicCreds

The result is the script runner is prompted with a login dialog for the U/P then, Invoke-WebRequest is able to access the site with those credentials. This works because $Creds.Password is already an encrypted string.

I hope this helps someone looking for a similar solution to the above question but without saving the username or PW in the script

Use this:

$root = 'REST_SERVICE_URL'
$user = "user"
$pass= "password"
$secpasswd = ConvertTo-SecureString $pass -AsPlainText -Force
$credential = New-Object System.Management.Automation.PSCredential($user, $secpasswd)

$result = Invoke-RestMethod $root -Credential $credential

If someone would need a one liner:

iwr -Uri 'https://api.github.com/user' -Headers @{ Authorization = "Basic "+ [System.Convert]::ToBase64String([System.Text.Encoding]::ASCII.GetBytes("user:pass")) }