(SQL Server) 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

// Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
//
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @cert int
    EXEC @hr = sp_OACreate 'Chilkat_9_5_0.Cert', @cert OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    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.
    DECLARE @success int
    EXEC sp_OAMethod @cert, 'LoadFromFile', @success OUT, 'qa_data/certs/testCert.cer'
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @cert, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @cert
        RETURN
      END

    -- Get the public key:
    DECLARE @pubKey int
    EXEC sp_OAMethod @cert, 'ExportPublicKey', @pubKey OUT
    EXEC sp_OAGetProperty @cert, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN
        EXEC sp_OAGetProperty @cert, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @cert
        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".

    EXEC sp_OAGetProperty @pubKey, 'KeyType', @sTmp0 OUT
    PRINT 'key type = ' + @sTmp0

    EXEC @hr = sp_OADestroy @pubKey


    EXEC @hr = sp_OADestroy @cert


END
GO