(PowerShell) Export a Private Key from an MS Storage Provider

Demonstrates how to export a private key from a Microsoft Storage Provider.

Note: This example requires Chilkat v9.5.0.83 or greater.

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Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

# This example requires Chilkat v9.5.0.83 or greater.

# We'll export a certificate's private key from the MS storage provider.
# It is assumed the certificate + private key is already installed on the Windows system.
# The export does not remove the key from the Windows storage provider.

# First, let's get a certificate in one of the many ways we can do it.
# (I ran certmgr.msc, opened a certificate, and noted it's thumbprint.)
$cert = New-Object Chilkat.Cert
$success = $cert.LoadByThumbprint("ea5a129c1919a52d238ee28d9f3a8f345b768388","hex")
if ($success -eq $false) {
    $($cert.LastErrorText)
    exit
}

$("Found: " + $cert.SubjectDN)

# First export the private key the easy way.
$privKey = $cert.ExportPrivateKey()
if ($cert.LastMethodSuccess -eq $false) {
    $($cert.LastErrorText)
    exit
}

# OK.. we have the private key.  Do whatever we want with it..

# -------------------------------------------------------------
# Now let's export in a more roundabout way by getting information about the 
# storage provider and key name and then we'll export completely independent
# of the certificate.
# 
# Remember: The private key is not contained within the certificate.  An X.509 certificate
# embeds the public key, but the counterpart private key is stored elsewhere, such
# as in a .pfx/.p12, or as in this case, in the Windows "protected store", or perhaps on
# a smartcard or hardware token.  (But a private key stored on a smartcard or token cannot
# be exported.  It must remain on the hardware.)
# 

$storageProvider = $cert.CspName
$keyName = $cert.KeyContainerName

$("Information about the certificate's private key:")
$("Storage Provider: " + $storageProvider)
$("Key Name: " + $keyName)

# Export using just the name of the storage provider and key.
$keyCon = New-Object Chilkat.KeyContainer
$privKey2 = New-Object Chilkat.PrivateKey
$silentFlag = $false
$success = $keyCon.ExportKey($keyName,$storageProvider,$silentFlag,$privKey2)
if ($success -eq $false) {
    $($keyCon.LastErrorText)
    exit
}

# OK.. we have the private key in privKey2.  Do whatever we want with it..
# Perhaps we save as encrypted PKCS8 PEM.
$success = $privKey2.SavePkcs8EncryptedPemFile("myPassword","qa_output/privKey2.pem")
if ($success -eq $false) {
    $($privKey2.LastErrorText)
    exit
}

$("Success.")