(VBScript) How to Parse a X.509 Certificate and Extract its Public Key

Demonstrates how to load an X.509 certificate and extract the public key. Chilkat supports many certificate encodings:

• DER (binary) encoded certificates (.crt/.cer)
• PEM (BASE64) encoded certificates (.pem)
• Load Certificates Directly from Windows Certificate Stores
• PFX/PKCS12 (.pfx/.p12)
• Java KeyStore (.jks)
• Cryptographic Message Syntax Standard - PKCS #7 Certificates (.P7B)

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Dim fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
'Create a Unicode (utf-16) output text file.
Set outFile = fso.CreateTextFile("output.txt", True, True)

' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.Cert")
set cert = CreateObject("Chilkat.Cert")

' Load a DER (binary) encoded certificate.
' To load from a .pem or .p7b, or any other file format that contains
' just one certificate, call LoadFromFile in exactly the same way.
' The LoadFromFile method automatically detects the format and loads the certificate.
success = cert.LoadFromFile("qa_data/certs/testCert.cer")
If (success = 0) Then
    outFile.WriteLine(cert.LastErrorText)
    WScript.Quit
End If

' Get the public key:
' pubKey is a Chilkat.PublicKey
Set pubKey = cert.ExportPublicKey()
If (cert.LastMethodSuccess <> 1) Then
    outFile.WriteLine(cert.LastErrorText)
    WScript.Quit
End If

' Examine the key type.
' A PublicKey object can contain an RSA, ECC, or DSA public key.
' The KeyType property will contain "rsa", "ecc", or "dsa".
outFile.WriteLine("key type = " & pubKey.KeyType)


outFile.Close