DataFlex

Load PEM ASN.1 and Convert to XML

See more ASN.1 Examples

Loads a CSR (Certificate Signing Request) from PEM and converts the ASN.1 to XML format. The purpose of this example is to compare the ASN.1 format with the corresponding XML. One means for accessing a particular piece of information within any ASN.1 document is to convert to XML, and then use any XML API to extract the required data.

The PEM used in this example may be downloaded here: Sample CSR PEM

It contains ASN.1 with this format:

After converting, the XML looks like this:

<?xml version="1.0" encoding="utf-8" ?>
<sequence>
    <sequence>
        <int>00</int>
        <sequence>
            <set>
                <sequence>
                    <oid>2.5.4.6</oid>
                    <printable>US</printable>
                </sequence>
            </set>
            <set>
                <sequence>
                    <oid>2.5.4.8</oid>
                    <utf8>Utah</utf8>
                </sequence>
            </set>
            <set>
                <sequence>
                    <oid>2.5.4.7</oid>
                    <utf8>Lindon</utf8>
                </sequence>
            </set>
            <set>
                <sequence>
                    <oid>2.5.4.10</oid>
                    <utf8>DigiCert Inc.</utf8>
                </sequence>
            </set>
            <set>
                <sequence>
                    <oid>2.5.4.11</oid>
                    <utf8>DigiCert</utf8>
                </sequence>
            </set>
            <set>
                <sequence>
                    <oid>2.5.4.3</oid>
                    <utf8>example.digicert.com</utf8>
                </sequence>
            </set>
        </sequence>
        <sequence>
            <sequence>
                <oid>1.2.840.113549.1.1.1</oid>
                <null />
            </sequence>
            <bits n="2160">3082010A0282010... </bits>
        </sequence>
        <contextSpecific tag="0" constructed="1" />
    </sequence>
    <sequence>
        <oid>1.2.840.113549.1.1.5</oid>
        <null />
    </sequence>
    <bits n="2048">1D2472B15C7129850E6...  </bits>
</sequence>

DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoPem
    String sPassword
    String sItemType
    String sItemSubType
    String sEncoding
    Integer iIndex
    String sCsrBase64
    Handle hoAsnRoot
    String sAsnXml
    Handle hoXmlObj
    String sTemp1

    Move False To iSuccess

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

    Move False To iSuccess

    Get Create (RefClass(cComChilkatPem)) To hoPem
    If (Not(IsComObjectCreated(hoPem))) Begin
        Send CreateComObject of hoPem
    End

    // Load the PEM file.  The password is ignored because it is not an encrypted PEM.
    Move "notRequired" To sPassword
    Get ComLoadPemFile Of hoPem "qa_data/asn/sampleCsr.pem" sPassword To iSuccess

    // Get the CSR in base64 format:
    Move "csr" To sItemType
    Move "" To sItemSubType
    Move "base64" To sEncoding
    Move 0 To iIndex
    Get ComGetEncodedItem Of hoPem sItemType sItemSubType sEncoding iIndex To sCsrBase64

    // Load the CSR base64 string into the ASN object
    Get Create (RefClass(cComChilkatAsn)) To hoAsnRoot
    If (Not(IsComObjectCreated(hoAsnRoot))) Begin
        Send CreateComObject of hoAsnRoot
    End

    Get ComLoadEncoded Of hoAsnRoot sCsrBase64 "base64" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoAsnRoot To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Get the ASN.1 in (Chilkat's) XML format:
    Get ComAsnToXml Of hoAsnRoot To sAsnXml

    // The XML returned by AsnToXml is one long difficult-to-read string 
    // with no linebreaks.  It is meant to be compact.
    // To get the XML in pretty, human-readable, indented form,
    // load into the Chilkat XML object an then retrieve:
    Get Create (RefClass(cComChilkatXml)) To hoXmlObj
    If (Not(IsComObjectCreated(hoXmlObj))) Begin
        Send CreateComObject of hoXmlObj
    End
    Get ComLoadXml Of hoXmlObj sAsnXml To iSuccess
    Get ComGetXml Of hoXmlObj To sAsnXml

    Showln sAsnXml


End_Procedure