(Excel) Download and Trust the DigiCert Global Root CA

Demonstrates how to download a root certificate and trust it.

For more information, see https://www.digicert.com/digicert-root-certificates.htm

Download Excel Class Modules Chilkat Excel Class Modules

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

' In this example, the URLs for the DigiCert root CA certs are available at this web page:
' https://www.digicert.com/digicert-root-certificates.htm

' This example downloads the "DigiCert Global Root G3"
' Valid until: 15/Jan/2038
' Serial #: 05:55:56:BC:F2:5E:A4:35:35:C3:A4:0F:D5:AB:45:72
' Thumbprint: 7E04DE896A3E666D00E687D33FFAD93BE83D349E


certUrl = "https://dl.cacerts.digicert.com/DigiCertGlobalRootG3.crt"

Dim http As Chilkat.Http
Set http = Chilkat.NewHttp
Dim bdCert As Chilkat.BinData
Set bdCert = Chilkat.NewBinData

success = http.DownloadBd(certUrl,bdCert)
If (success = False) Then
    Debug.Print http.LastErrorText
    Exit Sub
End If

' Load it into a Chilkat cert object.
Dim cert As Chilkat.Cert
Set cert = Chilkat.NewCert
success = cert.LoadFromBd(bdCert)
If (success = False) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

' Examine the common name,serial, and thumbprint:
Debug.Print "CN: "; cert.SubjectCN
Debug.Print "Serial: "; cert.SerialNumber
Debug.Print "Thumbprint: "; cert.Sha1Thumbprint

' Output from the above:
' CN: DigiCert Global Root G3
' Serial: 055556BCF25EA43535C3A40FD5AB4572
' Thumbprint: 7E04DE896A3E666D00E687D33FFAD93BE83D349E

' If desired, the certificate can be saved to a local file so it does not need
' to be downloaded from the website every time.  

certPath = "qa_data/certs/DigiCertGlobalRootG3.crt"
success = bdCert.WriteFile(certPath)

' To load the cert from a file...
success = cert.LoadFromFile(certPath)

' Do the following to add the cert to the collection of trusted roots
' for this application.  (Note:  The trust is not persisted.  Each time the
' application runs, it should load the cert (from whatever source, whether it is
' a file, a database,etc.) and do the following:
Dim troots As Chilkat.TrustedRoots
Set troots = Chilkat.NewTrustedRoots

Dim success As Boolean
success = troots.AddCert(cert)
success = troots.Activate()

Debug.Print cert.SubjectCN; " is now trusted for this run of this application."