A wrapper for creating and exporting self-signed certs as PFX files. Useful if setting up sites which require HTTPS config ahead of getting a proper cert (e.g. to configure HTTPS for app gateway before configuring LetsEncrypt per https://intelequia.com/blog/post/1012/automating-azure-application-gateway-ssl-certificate-renewals-with-let-s-encryp…

New-SelfSignedCertPfx.ps1

Function New-SelfSignedCertPfx {
    [CmdletBinding(DefaultParameterSetName = 'PasswordAsSecureString')]
    Param (
        [Parameter()]
        [string[]]$SanList = @('localhost', '127.0.0.1')
        ,
        [Parameter(ParameterSetName = 'PasswordAsSecureString')]
        [SecureString]$ExportPassword = [System.Security.SecureString]::new()
        ,
        # note: using the secure string option is recommended... but tbh most real world cases where you'd use this script you're just looking for something quick and easy
        [Parameter(ParameterSetName = 'PasswordAsString', Mandatory)]
        [string]$PlaintextExportPassword 
        ,
        [Parameter()]
        [string]$CertStorePath = 'cert:\localmachine\my'
        ,
        [Parameter()]
        [string]$PfxOutputPath = '.\selfSignedCert.pfx'
        ,
        [Parameter()]
        [DateTime]$DateTo = (Get-Date).ToUniversalTime().AddYears(1)
        ,
        [Parameter()]
        [Int32]$KeyLength = 2048
        ,
        [Parameter()]
        [Switch]$KeepInKeyStore
    )
    if ($PSCmdlet.ParameterSetName -eq 'PasswordAsString') {
        $ExportPassword = $PlaintextExportPassword | ConvertTo-SecureString -AsPlainText -Force
    }
    [HashTable]$splat = @{
        DnsName = $SanList
        CertStoreLocation = $CertStorePath
        NotAfter = $DateTo
        KeyLength = $KeyLength
    }
    [System.Security.Cryptography.X509Certificates.X509Certificate2]$tempCert = New-SelfSignedCertificate @splat
    Export-PfxCertificate -Cert $tempCert -FilePath $PfxOutputPath -Password $ExportPassword | Out-Null
    if (!$KeepInKeyStore.IsPresent) {
        Remove-Item -Path $tempCert.PSPath
    }
    return ([PSCustomObject]@{
        Path = $PfxOutputPath
        SanList = $SanList
        ExportPassword = $ExportPassword
        Certificate = $tempCert
    })
}