Posh-ACME

An ACME v2 (RFC 8555) client implemented as a Windows PowerShell module that enables you to generate publicly trusted SSL/TLS certificates from an ACME capable certificate authority such as Let's Encrypt.

Notable Features

• ACME v2 protocol support which allows generating wildcard certificates (*.example.com)
• Single command for new certs, New-PACertificate
• Easy renewals via Submit-Renewal
• RSA and ECC private keys supported for accounts and certificates
• Support for using existing certificate request (CSR)
• Account key rollover support
• OCSP Must-Staple support
• DNS challenge plugins for various DNS providers (pull requests welcome)
• DNS challenge CNAME support
• Help system for DNS plugins using Get-DnsPlugins and Get-DnsPluginHelp
• Multiple accounts supported per certificate authority which allows different certs to have different contact emails
• PEM and PFX output files
• No elevated Windows privileges required (unless using -Install switch)
• Cross platform PowerShell Core support! (FAQ)
• Manual HTTP challenge support (Guide)
• External Account Binding support for CAs that require it
• Preferred Chain support to use alternative CA trust chains

Install

Release

The latest release version can found in the PowerShell Gallery or the GitHub releases page. Installing from the gallery is easiest using Install-Module from the PowerShellGet module. See Installing PowerShellGet if you don't already have it installed.

# install for all users (requires elevated privs)
Install-Module -Name Posh-ACME -Scope AllUsers

# install for current user
Install-Module -Name Posh-ACME -Scope CurrentUser

NOTE: If you use PowerShell 5.1 or earlier, Install-Module may throw an error depending on your Windows and .NET version due to a change PowerShell Gallery made to their TLS settings. For more info and a workaround, see the official blog post.

Development

To install the latest development version from the git master branch, use the following PowerShell command. This method assumes a default PSModulePath environment variable.

# install latest dev version
iex (irm https://raw.githubusercontent.com/rmbolger/Posh-ACME/master/instdev.ps1)

Quick Start

On Windows, you may need to set a less restrictive PowerShell execution policy before you can import the module.

Set-ExecutionPolicy RemoteSigned -Scope CurrentUser -Force
Import-Module Posh-ACME

The minimum parameters you need for a cert are the domain name and the -AcceptTOS flag.

New-PACertificate example.com -AcceptTOS

This uses the default Manual DNS plugin which requires you to manually edit your DNS server to create the TXT records required for challenge validation. Here's a more complete example with a typical wildcard cert utilizing a hypothetical Flurbog DNS plugin that also adds a contact email address to the account for expiration notifications.

$certNames = '*.example.com','example.com'
$email = '[email protected]'
$pArgs = @{FBServer='fb.example.com'; FBCred=(Get-Credential)}

New-PACertificate $certNames -AcceptTOS -Contact $email -DnsPlugin Flurbog -PluginArgs $pArgs

To learn how to use the supported DNS plugins, check out Get-DnsPlugins and Get-DnsPluginHelp. There's also a tutorial for a more in-depth guide to using the module.

The output of New-PACertificate is an object that contains various properties about the certificate you generated. Only a subset of the properties are displayed by default. To see the full list including the filesystem paths to any certificate files that were generated, pipe the original output to Format-List or use Get-PACertificate | Format-List. The root config folder for all data saved by the module is either %LOCALAPPDATA%\Posh-ACME on Windows, ~/.config/Posh-ACME on Linux, or ~/Library/Preferences/Posh-ACME on Mac OS.

Requirements and Platform Support

• Supports Windows PowerShell 5.1 or later (Desktop edition) with .NET Framework 4.7.1 or later
• Supports PowerShell Core 6.0 or later (Core edition) on all supported OS platforms.
• Requires FullLanguage language mode

Changelog

See CHANGELOG.md