PowerShell signature function

Set-Signature.ps1

function Set-Signature {
    [CmdletBinding()]

    [Alias('sig')]

    param(

        [Parameter(
            Mandatory,
            Position = 0,
            ValueFromPipeline,
            ValueFromPipelineByPropertyName
        )]
        [ValidateScript({Test-Path -Path $PSItem})]
        [ValidateNotNullOrEmpty()]
        [string[]]$FilePath
    )

    BEGIN {
        $Certificate = Get-ChildItem -Path Cert:\CurrentUser\My -CodeSigningCert |
            Where-Object -Property NotAfter -GT (Get-Date) |
            Sort-Object -Property NotAfter -Descending |
            Select-Object -First 1
    }

    PROCESS {
        foreach ($Path in $FilePath) {
            $Params = @{
                Certificate     = $Certificate
                TimestampServer = 'http://timestamp.digicert.com'
                HashAlgorithm   = 'SHA256'
                FilePath        = $Path
                Verbose         = $True
            }
            Set-AuthenticodeSignature @Params
        }
    }
}