(CkPython) Convert Java KeyStore to PKCS12 / PFX

Loads a Java keystore file and saves it as a PKCS12 / PFX. A Java keystore (JKS) can contain two types of entries: (1) trusted root certificates or (2) private keys + cert chains. Usually a JKS will contain all entries of one type or another (and thus a particular JKS serves one purpose or another; meaning that a JKS containing trusted roots is used as a source for verifying pre-trusted roots, and a JKS containing private keys (and cert chains) is used as a secure, encrypted store for private keys).

A PKCS12 / PFX typically contains one or more private keys, along with each private key's certificate chain. Therefore, it typically makes sense to only write the private key entries to a PKCS12 (and the associated certificate chains). If a JKS contains trusted root certificates, it makes more sense to conver it to a PEM file (such as the CA cert bundle in PEM format from mozilla.org).

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import sys
import chilkat

# This requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

jks = chilkat.CkJavaKeyStore()

jksPassword = "myJksPassword"

# Load the Java keystore from a file.  The JKS file password is used
# to verify the keyed digest that is found at the very end of the keystore.
# It verifies that the keystore has not been modified.
success = jks.LoadFile(jksPassword,"/someDir/keyStore.jks")
if (success != True):
    print(jks.lastErrorText())
    sys.exit()

# To convert, we'll access the private key entries
# from the JKS, add each to the PKCS12, and then save the PKCS12.
pkcs12 = chilkat.CkPfx()

numPrivateKeys = jks.get_NumPrivateKeys()

# For each private key entry, get the private key and
# the associated certificate chain.
# Each private key is password protected.  Usually it is the same
# password as used for the keyed digest of the entire JKS.  
# However, this does not have to be.  The password is passed
# here to handle the possibility of each private key requiring
# a different password.
i = 0
while i < numPrivateKeys :
    # privKey is a CkPrivateKey
    privKey = jks.GetPrivateKey(jksPassword,i)
    print(jks.getPrivateKeyAlias(i))
    # certChain is a CkCertChain
    certChain = jks.GetCertChain(i)

    # Add the private key and it's associated certificate chain to the PKCS12.
    success = pkcs12.AddPrivateKey(privKey,certChain)
    if (success != True):
        print(pkcs12.lastErrorText())

        sys.exit()

    i = i + 1

# Save the PKCS12 / PFX to a file.
# The password can be the same as the JKS password, or something new.
# (With the PKCS12 format, there is a single password for the entire contents
# of the file.  With the JKS format, there is flexibility in allowing each private key
# to have it's own password.)
pkcs12Password = "myNewPassword"
success = pkcs12.ToFile(pkcs12Password,"/pkcs12_files/myPfx.p12")
if (success != True):
    print(pkcs12.lastErrorText())
else:
    print("Successfully saved to PKCS12 format.")