(Tcl) 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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load ./chilkat.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.)
set cert [new_CkCert]

set success [CkCert_LoadByThumbprint $cert "ea5a129c1919a52d238ee28d9f3a8f345b768388" "hex"]
if {$success == 0} then {
    puts [CkCert_lastErrorText $cert]
    delete_CkCert $cert
    exit
}

puts "Found: [CkCert_subjectDN $cert]"

# First export the private key the easy way.
# privKey is a CkPrivateKey
set privKey [CkCert_ExportPrivateKey $cert]
if {[CkCert_get_LastMethodSuccess $cert] == 0} then {
    puts [CkCert_lastErrorText $cert]
    delete_CkCert $cert
    exit
}

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

delete_CkPrivateKey $privKey

# -------------------------------------------------------------
# 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.)
# 

set storageProvider [CkCert_cspName $cert]
set keyName [CkCert_keyContainerName $cert]

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

# Export using just the name of the storage provider and key.
set keyCon [new_CkKeyContainer]

set privKey2 [new_CkPrivateKey]

set silentFlag 0
set success [CkKeyContainer_ExportKey $keyCon $keyName $storageProvider $silentFlag $privKey2]
if {$success == 0} then {
    puts [CkKeyContainer_lastErrorText $keyCon]
    delete_CkCert $cert
    delete_CkKeyContainer $keyCon
    delete_CkPrivateKey $privKey2
    exit
}

# OK.. we have the private key in privKey2.  Do whatever we want with it..
# Perhaps we save as encrypted PKCS8 PEM.
set success [CkPrivateKey_SavePkcs8EncryptedPemFile $privKey2 "myPassword" "qa_output/privKey2.pem"]
if {$success == 0} then {
    puts [CkPrivateKey_lastErrorText $privKey2]
    delete_CkCert $cert
    delete_CkKeyContainer $keyCon
    delete_CkPrivateKey $privKey2
    exit
}

puts "Success."

delete_CkCert $cert
delete_CkKeyContainer $keyCon
delete_CkPrivateKey $privKey2