(Ruby) 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.

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

# 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 = Chilkat::CkCert.new()
success = cert.LoadByThumbprint("ea5a129c1919a52d238ee28d9f3a8f345b768388","hex")
if (success == false)
    print cert.lastErrorText() + "\n";
    exit
end

print "Found: " + cert.subjectDN() + "\n";

# First export the private key the easy way.
# privKey is a CkPrivateKey
privKey = cert.ExportPrivateKey()
if (cert.get_LastMethodSuccess() == false)
    print cert.lastErrorText() + "\n";
    exit
end

# 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()

print "Information about the certificate's private key:" + "\n";
print "Storage Provider: " + storageProvider + "\n";
print "Key Name: " + keyName + "\n";

# Export using just the name of the storage provider and key.
keyCon = Chilkat::CkKeyContainer.new()
privKey2 = Chilkat::CkPrivateKey.new()
silentFlag = false
success = keyCon.ExportKey(keyName,storageProvider,silentFlag,privKey2)
if (success == false)
    print keyCon.lastErrorText() + "\n";
    exit
end

# 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 == false)
    print privKey2.lastErrorText() + "\n";
    exit
end

print "Success." + "\n";