Get-ContentSecurityPolicy.ps1

<#
.SYNOPSIS
Returns the content security policy at from the given URL.

.INPUTS
Microsoft.PowerShell.Commands.WebResponseObject from Invoke-WebRequest
or
any object with a Uri or Url property

.OUTPUTS
System.Management.Automation.PSCustomObject containing the parsed policy.

.FUNCTIONALITY
HTTP

.LINK
https://content-security-policy.com/

.LINK
Invoke-WebRequest

.EXAMPLE
Invoke-WebRequest http://example.org/ |Get-ContentSecurityPolicy.ps1

default-src : {http://example.org, http://example.net, 'self'}
script-src  : {'self'}
img-src     : {'self'}
report-uri  : {http://example.com/csp}
#>

#Requires -Version 3
[CmdletBinding()][OutputType([Management.Automation.PSCustomObject])] Param(
# The URL to get the policy from.
[Parameter(ParameterSetName='Uri',Position=0,Mandatory=$true,ValueFromPipelineByPropertyName=$true)]
[Alias('Url')][Uri] $Uri,
# The output from Invoke-WebRequest to parse the policy from.
[Parameter(ParameterSetName='Response',Mandatory=$true,ValueFromPipeline=$true)]
[Microsoft.PowerShell.Commands.WebResponseObject] $Response
)
Process
{
    if($Uri){$Response = Invoke-WebRequest $Uri -UseBasicParsing}
    if(!$Response.Headers.ContainsKey('Content-Security-Policy')){return}
    $csp = @{}
    $Response.Headers['Content-Security-Policy'] -split '\s*;\s*' |
        ForEach-Object {$directive,$values=$_ -split '\s+'; $csp[$directive]=[string[]]$values}
    return [pscustomobject]$csp
}