Export Public Key to RSA DER, OpenSSL DER/PEM, XML

Demonstrates how to export a digital certificate's public key to RSA DER, OpenSSL PEM or DER, or to XML format.

Dim fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
Set outFile = fso.CreateTextFile("output.txt", True)

set cert = CreateObject("Chilkat.Cert")

'  Th LoadByCommonName method searches the Windows
'  Current User Certificate Store and Local Machine Certificate
'  Store for a certificate whose common name (CN) matches
'  the argument:

success = cert.LoadByCommonName("Chilkat Software, Inc.")
If (success = 0) Then
    MsgBox "Failed to find certificate!"
Else

    '  Get the PublicKey object:

    Set pkey = cert.ExportPublicKey()
    If (Not (pkey Is Nothing )) Then

        '  Export the public key to an RSA DER file:
        pkey.SaveRsaDerFile "pubkey_rsa.der"

        '  Export to an OpenSSL DER file:
        pkey.SaveOpenSslDerFile "pubkey_openssl.der"

        '  Export to an OpenSSL PEM file:
        pkey.SaveOpenSslPemFile "pubkey_openssl.pem"

        '  Export to an XML file:
        pkey.SaveXmlFile "pubkey.xml"

        '  Get OpenSSL PEM string:
        outFile.WriteLine("OpenSSL PEM Public Key:")
        outFile.WriteLine(pkey.GetOpenSslPem())

    Else
        MsgBox "No public key found!"
    End If

End If

'  The Chilkat Certificate, Certificate Store, Private Key,
'  Public Key, and Key Container classes / objects are freeware.

'  They are used by and included with the Chilkat Email,
'  Crypt, S/MIME, and other commercial Chilkat components.

outFile.Close