Visual FoxPro

Load .crl, Convert to XML, Get Revoked Serial Numbers and Dates

See more Certificates Examples

Load a binary .crl file (Certificate Revocation List), converts to XML, and then gets the revoked certificate serial numbers and revocation dates.

Note: This example requires Chilkat v9.5.0.77 or greater.

Visual FoxPro

LOCAL lnSuccess
LOCAL loBdCrl
LOCAL loAsn
LOCAL loXml
LOCAL i
LOCAL lnCount_i
LOCAL lcTagPath
LOCAL j
LOCAL lnCount_j
LOCAL k
LOCAL lnCount_k
LOCAL lcRevokedCertSerialHex
LOCAL lcDateRevoked
LOCAL loDt

lnSuccess = 0

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

* Load a binary .crl file.
loBdCrl = CreateObject('Chilkat.BinData')
lnSuccess = loBdCrl.LoadFile("qa_data/crl/ca1.crl")
IF (lnSuccess <> 1) THEN
    ? "Failed to load CRL file."
    RELEASE loBdCrl
    CANCEL
ENDIF

loAsn = CreateObject('Chilkat.Asn')
lnSuccess = loAsn.LoadBd(loBdCrl)
IF (lnSuccess <> 1) THEN
    ? loAsn.LastErrorText
    RELEASE loBdCrl
    RELEASE loAsn
    CANCEL
ENDIF

* Convert ASN.1 to XML and load into xml and re-emit for pretty printing..
loXml = CreateObject('Chilkat.Xml')
loXml.LoadXml(loAsn.AsnToXml())
lnSuccess = loXml.SaveXml("qa_output/crl.xml")

* Use this online tool to generate parsing code from CRL XML: 
* Generate Parsing Code from XML

* Here's code to parse the XML.  This code was generated by the above tool,
* and then we modified it by removing unneeded code and changing some names

loDt = CreateObject('Chilkat.CkDateTime')

i = 0
lnCount_i = loXml.NumChildrenHavingTag("sequence")
DO WHILE i < lnCount_i
    loXml.I = i

    j = 0
    lnCount_j = loXml.NumChildrenHavingTag("sequence[i]|sequence")
    DO WHILE j < lnCount_j
        loXml.J = j

        k = 0
        lnCount_k = loXml.NumChildrenHavingTag("sequence[i]|sequence[j]|sequence")
        DO WHILE k < lnCount_k
            loXml.K = k

            * Get the revoked certificate's serial number in uppercase hex.
            lcRevokedCertSerialHex = loXml.GetChildContent("sequence[i]|sequence[j]|sequence[k]|int")
            ? "serial number: " + lcRevokedCertSerialHex

            * Get the date/time revoked.  It will be a string formatted as "YYMMDDhhmmssZ", such as "181023093028Z"
            lcDateRevoked = loXml.GetChildContent("sequence[i]|sequence[j]|sequence[k]|utctime")

            * Starting in Chilkat v9.5.0.77, date/time strings formatted as YYMMDDhhmmssZ can be parsed as follows:
            loDt.SetFromTimestamp(lcDateRevoked)
            ? "date revoked: " + loDt.GetAsRfc822(0)

            k = k + 1
        ENDDO
        j = j + 1
    ENDDO
    i = i + 1
ENDDO

RELEASE loBdCrl
RELEASE loAsn
RELEASE loXml
RELEASE loDt