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

问题

Initial Question

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.

Edit (This is What Worked)

Notes are from Wikipedia on Basic Auth from the Client Side.

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

Thank you to @briantist for the help!

Discussion

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?

回答1:

I am assuming Basic authentication here.

$cred = Get-Credential
Invoke-WebRequest -Uri 'https://whatever' -Credential $cred

You can get your credential through other means (Import-Clixml, etc.), but it does have to be a [PSCredential] object.

Edit based on comments:

GitHub is breaking RFC as they explain in the link you provided:

The API supports Basic Authentication as defined in RFC2617 with a few slight differences. The main difference is that the RFC requires unauthenticated requests to be answered with 401 Unauthorized responses. In many places, this would disclose the existence of user data. Instead, the GitHub API responds with 404 Not Found. This may cause problems for HTTP libraries that assume a 401 Unauthorized response. The solution is to manually craft the Authorization header.

Powershell's Invoke-WebRequest does to my knowledge wait for a 401 response before sending the credentials, and since GitHub never provides one, your credentials will never be sent.

Manually build the headers

Instead you'll have to create the basic auth headers yourself.

Basic authentication takes a string that consists of the username and password separated by a colon user:pass and then sends the Base64 encoded result of that.

Code like this should work:

$user = 'user'
$pass = 'pass'

$pair = "$($user):$($pass)"

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

$basicAuthValue = "Basic $encodedCreds"

$Headers = @{
    Authorization = $basicAuthValue
}

Invoke-WebRequest -Uri 'https://whatever' -Headers $Headers

You could combine some of the string concatenation but I wanted to break it out to make it clearer.

回答2:

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

回答3:

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

回答4:

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

回答5:

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

来源：https://stackoverflow.com/questions/27951561/use-invoke-webrequest-with-a-username-and-password-for-basic-authentication-on-t