Encrypting and decrypting PGP using PowerShell

By Przemyslaw Klys PowerShell Windows September 12, 2021

Some time ago, I decided that having an easy-to-use PGP PowerShell module is a way to kill my boredom. Four months have passed, and I decided to share it with the world, as it may be helpful to some of you. Today I would like to introduce you to PSPGP – PowerShell module that provides PGP functionality in PowerShell.

PSPGP - Commands available

PSPGP is a fairly small PowerShell module that has only four commands at the moment of writing. Those are:

New-PGPKey – cmdlet to create public/private PGP keys

Protect-PGP – cmdlet to encrypt folder/files

Unprotect-PGP – decrypt PGP encrypted folder/file

Test-PGP – verify signed PGP file

While the module itself is tiny – that's what makes it very powerful and easy to use.

PSPGP - Create Private/Public PGP keys

PGP works based on public and private keys. Those can be generated using the New-PGPKey command, as shown below

New-PGPKey -FilePathPublic $PSScriptRoot\Keys\PublicPGP.asc -FilePathPrivate $PSScriptRoot\Keys\PrivatePGP.asc -UserName 'przemyslaw.klys' -Password 'ZielonaMila9!'

PSPGP - Encrypt files & folders with PGP

Once you have private and public keys generated, you're ready to encrypt the folder using someone's public key and send it over.

Protect-PGP -FilePathPublic $PSScriptRoot\Keys\PublicPGP.asc -FolderPath $PSScriptRoot\Test -OutputFolderPath $PSScriptRoot\Encoded

PSPGP - Decrypt PGP files

Similarly, if someone sends you content encrypted with a public key, you can now decrypt it with your own private key and password.

Unprotect-PGP -FilePathPrivate $PSScriptRoot\Keys\PrivatePGP.asc -Password 'ZielonaMila9!' -FolderPath $PSScriptRoot\Encoded -OutputFolderPath $PSScriptRoot\Decoded

Of course, PGP also supports a way to encrypt/decrypt strings.

$ProtectedString = Protect-PGP -FilePathPublic $PSScriptRoot\Keys\PublicPGP.asc -String "This is string to encrypt"
Unprotect-PGP -FilePathPrivate $PSScriptRoot\Keys\PrivatePGP.asc -Password 'ZielonaMila9!' -String $ProtectedString

PSPGP - Verify signature of PGP files

Finally, one can always verify signature by using Test-PGP command

$ProtectedString = Protect-PGP -FilePathPublic $PSScriptRoot\Keys\PublicPGP.asc -String "This is string to encrypt"
Test-PGP -FilePathPublic $PSScriptRoot\Keys\PublicPGP.asc -String $ProtectedString
Test-PGP -FilePathPublic $PSScriptRoot\Keys\PublicPGP.asc -FolderPath $PSScriptRoot\Encoded

PSPGP - Installing PGP PowerShell Module

To run it, just install it from PowerShellGallery, and you're good. If you are not an administrator, you can use this module within the scope of the current user.

Install-Module PSPGP -Force -Scope CurrentUser

If, however, you would like to make sure the module is available machine-wide, you can do this without providing scope.

Install-Module PSPGP -Force

All source codes are available on GitHub. If you have an issue, feature request, problem, please use GitHub as a way to reach for support. As I have limited time, reaching out via email doesn't bring many results. As with many of my other PowerShell modules, it's always a work in progress, and not everything is 100% finished. Please keep in mind this module works cross-platform on Windows/Linux and macOS. For PowerShell 5.1, it requires .NET Framework 4.7.2 at a minimum to work.

Przemyslaw Klys / About Author

System Architect with over 14 years of experience in the IT field. Skilled, among others, in Active Directory, Microsoft Exchange and Office 365. Profoundly interested in PowerShell. Software geek.

Encrypting and decrypting PGP using PowerShell

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