(Visual FoxPro) 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).

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loJks
LOCAL lcJksPassword
LOCAL lnSuccess
LOCAL loPkcs12
LOCAL lnNumPrivateKeys
LOCAL i
LOCAL loPrivKey
LOCAL loCertChain
LOCAL lcPkcs12Password

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

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JavaKeyStore')
loJks = CreateObject('Chilkat.JavaKeyStore')

lcJksPassword = "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.
lnSuccess = loJks.LoadFile(lcJksPassword,"/someDir/keyStore.jks")
IF (lnSuccess <> 1) THEN
    ? loJks.LastErrorText
    RELEASE loJks
    CANCEL
ENDIF

* To convert, we'll access the private key entries
* from the JKS, add each to the PKCS12, and then save the PKCS12.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Pfx')
loPkcs12 = CreateObject('Chilkat.Pfx')

lnNumPrivateKeys = loJks.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
DO WHILE i < lnNumPrivateKeys
    loPrivKey = loJks.GetPrivateKey(lcJksPassword,i)
    ? loJks.GetPrivateKeyAlias(i)
    loCertChain = loJks.GetCertChain(i)

    * Add the private key and it's associated certificate chain to the PKCS12.
    lnSuccess = loPkcs12.AddPrivateKey(loPrivKey,loCertChain)
    IF (lnSuccess <> 1) THEN
        ? loPkcs12.LastErrorText
        RELEASE loCertChain
        RELEASE loPrivKey
        RELEASE loJks
        RELEASE loPkcs12
        CANCEL
    ENDIF

    RELEASE loCertChain
    RELEASE loPrivKey
    i = i + 1
ENDDO

* 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.)
lcPkcs12Password = "myNewPassword"
lnSuccess = loPkcs12.ToFile(lcPkcs12Password,"/pkcs12_files/myPfx.p12")
IF (lnSuccess <> 1) THEN
    ? loPkcs12.LastErrorText
ELSE
    ? "Successfully saved to PKCS12 format."
ENDIF

RELEASE loJks
RELEASE loPkcs12