(SQL Server) Verify XML Signature having KeyInfo / X509Data / X509SKI

This example demonstrates how to verify an XML Digital Signature where the KeyInfo element contains an X509Data element,
which in turn contains an X509SKI element which contains only the signing certificate's Subject Key Identifier (SKI).

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
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    -- This example requires the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    -- The SOAP XML with digital signature verified in this example is available at 
    -- https://www.chilkatsoft.com/exampleData/sigWithX509SKI.xml

    DECLARE @signedSoapXmlUrl nvarchar(4000)
    SELECT @signedSoapXmlUrl = 'https://www.chilkatsoft.com/exampleData/sigWithX509SKI.xml'

    -- First, let's get the signed SOAP XML..
    DECLARE @http int
    -- Use "Chilkat_9_5_0.Http" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Http', @http OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @sbXml int
    -- Use "Chilkat_9_5_0.StringBuilder" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbXml OUT

    DECLARE @success int
    EXEC sp_OAMethod @http, 'QuickGetSb', @success OUT, @signedSoapXmlUrl, @sbXml
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @http, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @http
        EXEC @hr = sp_OADestroy @sbXml
        RETURN
      END

    -- The signed XML downloaded from the above URL contains the following.

    -- <?xml version="1.0" encoding="UTF-8" standalone="no" ?>
    -- <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
    --     <SOAP-ENV:Header>
    --         <wsse:Security xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" SOAP-ENV:mustUnderstand="1"><ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#"><ds:SignedInfo><ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"><InclusiveNamespaces xmlns="http://www.w3.org/2001/10/xml-exc-c14n#" PrefixList="wsse SOAP-ENV"/></ds:CanonicalizationMethod><ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#rsa-sha256"/><ds:Reference URI="#Body"><ds:Transforms><ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/></ds:Transforms><ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/><ds:DigestValue>PIiVPpuMc1jGpWaL8ftzTOcc4gc=</ds:DigestValue></ds:Reference></ds:SignedInfo><ds:SignatureValue>Rlta8LplnFH0q8L+UeVmh4Smdn6oVETi4RoUmpT/KQX3RNAIOdCVE3b7gjmx5+3vp3DhjphOsZvW6dXzkI46xt9pD5otp3b/ZppGqKzltggo9gyQtPvJ8ltJZqVKYOGo5uElRFF/xm/zcx5Y3E14t+LYVSlv2lbem/zZ5zQ7ai8DmGD33id7nGu+MXVwb3kGkJFYoB/GOXtwsep+bcilMglTp8/7SBfBaVFKxWVBp4N2NW7bGlyDct8FaCk9hXQDNm/kqne9GU87tgh8/rbsFCYgyqIRMIvMPvhRWr2EKdEKyLtlZ8w0KYJYpgsf4T7SDghemzXkJoJPrfUQmHudIw==</ds:SignatureValue><ds:KeyInfo><ds:X509Data><ds:X509SKI>bDMtm8bAimMlGLU2M/82W8+y3tM=</ds:X509SKI></ds:X509Data></ds:KeyInfo></ds:Signature></wsse:Security>
    --     </SOAP-ENV:Header>
    --     <SOAP-ENV:Body xmlns:SOAP-SEC="http://schemas.xmlsoap.org/soap/security/2000-12" SOAP-SEC:id="Body">
    --         <z:FooBar xmlns:z="http://example.com" />
    --     </SOAP-ENV:Body>
    -- </SOAP-ENV:Envelope>

    -- Note: We don't have everything we need to verify the signature.
    -- The KeyInfo part of the Signature contains only the signing cert's Subject Key Identifier.  
    -- We must obtain the certificate locally using this information.  
    -- 
    -- On a Windows system, if the matching certificate is already installed in the registry-based
    -- certificate stores, then your application does not need to do anything.  Chilkat will automatically
    -- locate and use the matching certificate installed on the Windows system.
    -- 
    -- This example will assume we're not on a Windows system, or that the matching certificate
    -- is not already installed on the system.
    -- 

    -- One strategy for providing certificates to the application doing the XML signature verification 
    -- is to load all possible certificates into an in-memory XmlCertVault beforehand, and then call
    -- UseCertVault to allow for Chilkat to automatically find the matching cert from the pre-loaded certificates.
    -- We'll do that here with the one certificate that we already know is the matching certificate.

    DECLARE @sbCertPem int
    -- Use "Chilkat_9_5_0.StringBuilder" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbCertPem OUT

    EXEC sp_OAMethod @http, 'QuickGetSb', @success OUT, 'https://chilkatdownload.com/example_data/testcertificate.pem', @sbCertPem
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @http, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @http
        EXEC @hr = sp_OADestroy @sbXml
        EXEC @hr = sp_OADestroy @sbCertPem
        RETURN
      END

    -- Create a cert vault and add the certificates.
    -- In this example, we're only adding a single certificate.  An application
    -- could load many certificates into the cert vault..
    DECLARE @certVault int
    -- Use "Chilkat_9_5_0.XmlCertVault" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.XmlCertVault', @certVault OUT

    EXEC sp_OAMethod @sbCertPem, 'GetAsString', @sTmp0 OUT
    EXEC sp_OAMethod @certVault, 'AddCertString', @success OUT, @sTmp0
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @certVault, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @http
        EXEC @hr = sp_OADestroy @sbXml
        EXEC @hr = sp_OADestroy @sbCertPem
        EXEC @hr = sp_OADestroy @certVault
        RETURN
      END

    DECLARE @verifier int
    -- Use "Chilkat_9_5_0.XmlDSig" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.XmlDSig', @verifier OUT

    -- Tell the verifier to use the certVault as a source for locating
    -- matching certificates.
    EXEC sp_OAMethod @verifier, 'UseCertVault', @success OUT, @certVault

    EXEC sp_OAMethod @verifier, 'LoadSignatureSb', @success OUT, @sbXml
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @verifier, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @http
        EXEC @hr = sp_OADestroy @sbXml
        EXEC @hr = sp_OADestroy @sbCertPem
        EXEC @hr = sp_OADestroy @certVault
        EXEC @hr = sp_OADestroy @verifier
        RETURN
      END

    DECLARE @bVerified int
    EXEC sp_OAMethod @verifier, 'VerifySignature', @bVerified OUT, 1
    IF @bVerified <> 1
      BEGIN
        EXEC sp_OAGetProperty @verifier, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @http
        EXEC @hr = sp_OADestroy @sbXml
        EXEC @hr = sp_OADestroy @sbCertPem
        EXEC @hr = sp_OADestroy @certVault
        EXEC @hr = sp_OADestroy @verifier
        RETURN
      END


    PRINT 'Signature verified!'

    EXEC @hr = sp_OADestroy @http
    EXEC @hr = sp_OADestroy @sbXml
    EXEC @hr = sp_OADestroy @sbCertPem
    EXEC @hr = sp_OADestroy @certVault
    EXEC @hr = sp_OADestroy @verifier


END
GO