(DataFlex) 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

Use ChilkatAx-9.5.0-win32.pkg

Procedure Test
    Handle hoCert
    Boolean iSuccess
    Variant vPubKey
    Handle hoPubKey
    String sTemp1
    Boolean bTemp1

    Get Create (RefClass(cComChilkatCert)) To hoCert
    If (Not(IsComObjectCreated(hoCert))) Begin
        Send CreateComObject of hoCert
    End

    //  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.
    Get ComLoadFromFile Of hoCert "qa_data/certs/testCert.cer" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoCert To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Get the public key:
    Get ComExportPublicKey Of hoCert To vPubKey
    If (IsComObject(vPubKey)) Begin
        Get Create (RefClass(cComChilkatPublicKey)) To hoPubKey
        Set pvComObject Of hoPubKey To vPubKey
    End
    Get ComLastMethodSuccess Of hoCert To bTemp1
    If (bTemp1 <> True) Begin
        Get ComLastErrorText Of hoCert To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  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".
    Get ComKeyType Of hoPubKey To sTemp1
    Showln "key type = " sTemp1

    Send Destroy of hoPubKey


End_Procedure