Xojo Plugin

Get Certificate Authority Information Access

See more Certificates Examples

Demonstrates how to get a certificate's Authority Information Access extension data (if it exists).

Note: This example requires Chilkat v9.5.0.76 or greater.

Xojo Plugin

Dim success As Boolean
success = False

Dim cert As New Chilkat.Cert

success = cert.LoadFromFile("qa_data/certs/test_haswdt.cer")
If (success <> True) Then
    System.DebugLog(cert.LastErrorText)
    Return
End If

// Get the Authority Information Access extension, which is at OID 1.3.6.1.5.5.7.1.1
Dim extensionXmlStr As String
extensionXmlStr = cert.GetExtensionAsXml("1.3.6.1.5.5.7.1.1")
If (cert.LastMethodSuccess = False) Then
    System.DebugLog("Certificate does not have the AuthInfoAccess extension.")
    Return
End If

Dim xml As New Chilkat.Xml
success = xml.LoadXml(extensionXmlStr)

// See what we have..
System.DebugLog(xml.GetXml())

// We should get XML like this:

// <?xml version="1.0" encoding="utf-8" ?>
// <sequence>
//     <sequence>
//         <oid>1.3.6.1.5.5.7.48.2</oid>
//         <contextSpecific tag="6" constructed="0">aHR0cDovL2NydC5jb21vZG9jYS5jb20vQ09NT0RPUlNBQ2xpZW50QXV0aGVudGljYXRpb25hbmRTZWN1
// cmVFbWFpbENBLmNydA==</contextSpecific>
//     </sequence>
//     <sequence>
//         <oid>1.3.6.1.5.5.7.48.1</oid>
//         <contextSpecific tag="6" constructed="0">aHR0cDovL29jc3AuY29tb2RvY2EuY29t</contextSpecific>
//     </sequence>
// </sequence>

// Typically, a certificate AIA(Authority Information access) contains 2 parts:
// 
//     On-line Certificate Status Protocol (1.3.6.1.5.5.7.48.1)
//     Certification Authority Issuer (1.3.6.1.5.5.7.48.2)
// 
// The base64 content for each OID (in this case) is just a string.  
// The data can be accessed and decoded like this:

Dim sbOcsp As New Chilkat.StringBuilder
success = xml.GetChildContentSb("/C/oid,1.3.6.1.5.5.7.48.1|++",sbOcsp)
If (success = True) Then
    success = sbOcsp.Decode("base64","utf-8")
    System.DebugLog("1.3.6.1.5.5.7.48.1:  " + sbOcsp.GetAsString())
End If

Dim sbIssuer As New Chilkat.StringBuilder
success = xml.GetChildContentSb("/C/oid,1.3.6.1.5.5.7.48.2|++",sbIssuer)
If (success = True) Then
    success = sbIssuer.Decode("base64","utf-8")
    System.DebugLog("1.3.6.1.5.5.7.48.2:  " + sbIssuer.GetAsString())
End If

// The output looks like this:

// 1.3.6.1.5.5.7.48.1:  http://ocsp.comodoca.com
// 1.3.6.1.5.5.7.48.2:  http://crt.comodoca.com/COMODORSAClientAuthenticationandSecureEmailCA.crt

// -------------------------------------------------------------------------------
// Note: The Chilkat path passed to GetChildContentSb is composed of two commands:
// The first command is "/C/oid,1.3.6.1.5.5.7.48.1".   It says "traverse the XML tree from the caller
// node and stop at the 1st node having tag = "oid" and content = "1.3.6.1.5.5.7.48.1".
// The "|" char separates the 1st command from the 2nd.
// The 2nd command is "++" and says "move to the next sibling".