(VB.NET) Load .crl, Convert to XML, Get Revoked Serial Numbers and Dates

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.

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

' Load a binary .crl file.
Dim bdCrl As New Chilkat.BinData
Dim success As Boolean = bdCrl.LoadFile("qa_data/crl/ca1.crl")
If (success <> True) Then
    Debug.WriteLine("Failed to load CRL file.")
    Exit Sub
End If


Dim asn As New Chilkat.Asn
success = asn.LoadBd(bdCrl)
If (success <> True) Then
    Debug.WriteLine(asn.LastErrorText)
    Exit Sub
End If


' Convert ASN.1 to XML and load into xml and re-emit for pretty printing..
Dim xml As New Chilkat.Xml
xml.LoadXml(asn.AsnToXml())
success = xml.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
Dim i As Integer
Dim count_i As Integer
Dim tagPath As String
Dim j As Integer
Dim count_j As Integer
Dim k As Integer
Dim count_k As Integer

Dim revokedCertSerialHex As String
Dim dateRevoked As String

Dim dt As New Chilkat.CkDateTime

i = 0
count_i = xml.NumChildrenHavingTag("sequence")
While i < count_i
    xml.I = i

    j = 0
    count_j = xml.NumChildrenHavingTag("sequence[i]|sequence")
    While j < count_j
        xml.J = j

        k = 0
        count_k = xml.NumChildrenHavingTag("sequence[i]|sequence[j]|sequence")
        While k < count_k
            xml.K = k

            ' Get the revoked certificate's serial number in uppercase hex.
            revokedCertSerialHex = xml.GetChildContent("sequence[i]|sequence[j]|sequence[k]|int")
            Debug.WriteLine("serial number: " & revokedCertSerialHex)

            ' Get the date/time revoked.  It will be a string formatted as "YYMMDDhhmmssZ", such as "181023093028Z"
            dateRevoked = xml.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:
            dt.SetFromTimestamp(dateRevoked)
            Debug.WriteLine("date revoked: " & dt.GetAsRfc822(False))

            k = k + 1
        End While
        j = j + 1
    End While
    i = i + 1
End While