Geek Answers Handbook

Signing a PowerShell script with self-signed certificates (without makecert.exe)

I am trying to sign .ps1using self-signed certificates (the use case is for scripts that I write on my own private dev station, so I don’t need to use or pay - this is a real CA). However, no matter how many instructions on the topic of creating certificates and digital signatures I read, I can not get it to work.

Here is what I have done so far:

# Create a certificate to use as trusted root of the signing chain
$root = New-SelfSignedCertificate `
    -Subject "CN=PowerShell Trusted Authority" `
    -FriendlyName "PowerShell Trusted Authority" `
    -KeyUsageProperty Sign `
    -KeyUsage CertSign, CRLSign, DigitalSignature `
    -CertStoreLocation Cert:\LocalMachine\My\ `
    -NotAfter (Get-Date).AddYears(10)

# Create a certificate to use for signing powershell scripts
New-SelfSignedCertificate `
    -Signer $root `
    -Subject "CN=PowerShell Code Signing" `
    -KeyAlgorithm RSA `
    -KeyLength 2048 `
    -Type CodeSigningCert `
    -CertStoreLocation Cert:\LocalMachine\My\

# Move the root cert into Trusted Root CAs
 Move-Item "Cert:\LocalMachine\My\$($root.Thumbprint)" Cert:\LocalMachine\Root

All of the above is done from an administrative powershell instance. After that, I can see both certificates in the expected places in the management console, and the path of the certificate of the signing certificate is verified as valid.

Then I open the regular PS prompt and try to sign the script:

# Obtain a reference to the signing certificate
PS> $cert = Get-ChildItem Cert:\LocalMachine\My\ -CodeSigningCert

# Attempt at signing
PS> Set-AuthenticodeSignature .\Microsoft.PowerShell_profile.ps1 $cert


    Directory: C:\Users\tomas\Documents\WindowsPowerShell


SignerCertificate          Status                Path
-----------------          ------                ----
                           UnknownError          Microsoft.PowerShell_profile.ps1

, . powershell, , script ​​.

, , , ; - script, Set-AuthenticodeSignature, UnknownError, AllSigned - .

# Output some info about the certificate:
PS> $cert | Format-List

Subject      : CN=PowerShell Code Signing
Issuer       : CN=PowerShell Trusted Authority
Thumbprint   : <omitted>
FriendlyName :
NotBefore    : 9/20/2017 10:48:59 PM
NotAfter     : 9/20/2018 11:08:59 PM
Extensions   : {System.Security.Cryptography.Oid, System.Security.Cryptography.Oid, 
                System.Security.Cryptography.Oid, System.Security.Cryptography.Oid}

New-SelfSignedCertificate, , (UnknownError).

, Set-ExecutionPolicy AllSigned , . , ?

+6
1

, , . Trusted Root, . , , , , "root" , .

SELF SIGNED CERTIFICATE

# Create a certificate to use for signing powershell scripts
$selfsigncert = New-SelfSignedCertificate `
                -Subject "CN=PowerShell Code Signing" `
                -KeyAlgorithm RSA `
                -KeyLength 2048 `
                -Type CodeSigningCert `
                -CertStoreLocation Cert:\LocalMachine\My\

# Move the root cert into Trusted Root CAs
Move-Item "Cert:\LocalMachine\My\$($selfsigncert.Thumbprint)" Cert:\LocalMachine\Root

# Obtain a reference to the code signing cert in Trusted Root
$selfsignrootcert = "Cert:\LocalMachine\Root\$($selfsigncert.Thumbprint)"

# Sign script
Set-AuthenticodeSignature C:\powershell.ps1 $selfsignrootcert

, , .

ROOT CA ( , ) - Root CA

# Get Enterprise Root CA thumbprint
$rootcert = get-childitem Cert:\LocalMachine\Root\XXXXXXXXXXXX


# Generate certificate
$fromrootcert = New-SelfSignedCertificate `
                -Signer $rootcert `
                -Subject "CN=PowerShell Code Signing" `
                -KeyAlgorithm RSA `
                -KeyLength 2048 `
                -Type CodeSigningCert `
                -CertStoreLocation Cert:\LocalMachine\My\

# Sign script
Set-AuthenticodeSignature C:\powershell.ps1 $fromrootcert

, .

+1

More articles:


All Articles