(Lianja) 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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// 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.)
loCert = createobject("CkCert")
llSuccess = loCert.LoadByThumbprint("ea5a129c1919a52d238ee28d9f3a8f345b768388","hex")
if (llSuccess = .F.) then
    ? loCert.LastErrorText
    release loCert
    return
endif

? "Found: " + loCert.SubjectDN

// First export the private key the easy way.
loPrivKey = loCert.ExportPrivateKey()
if (loCert.LastMethodSuccess = .F.) then
    ? loCert.LastErrorText
    release loCert
    return
endif

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

release loPrivKey

// -------------------------------------------------------------
// 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.)
// 

lcStorageProvider = loCert.CspName
lcKeyName = loCert.KeyContainerName

? "Information about the certificate's private key:"
? "Storage Provider: " + lcStorageProvider
? "Key Name: " + lcKeyName

// Export using just the name of the storage provider and key.
loKeyCon = createobject("CkKeyContainer")
loPrivKey2 = createobject("CkPrivateKey")
llSilentFlag = .F.
llSuccess = loKeyCon.ExportKey(lcKeyName,lcStorageProvider,llSilentFlag,loPrivKey2)
if (llSuccess = .F.) then
    ? loKeyCon.LastErrorText
    release loCert
    release loKeyCon
    release loPrivKey2
    return
endif

// OK.. we have the private key in privKey2.  Do whatever we want with it..
// Perhaps we save as encrypted PKCS8 PEM.
llSuccess = loPrivKey2.SavePkcs8EncryptedPemFile("myPassword","qa_output/privKey2.pem")
if (llSuccess = .F.) then
    ? loPrivKey2.LastErrorText
    release loCert
    release loKeyCon
    release loPrivKey2
    return
endif

? "Success."


release loCert
release loKeyCon
release loPrivKey2