(SQL Server) Create XML Signature with External Data Reference

Demonstrates how to create an XML digital signature where the data is external. In this case, the data is a JPG file.

This example requires Chilkat v9.5.0.69 or greater.

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.

    -- This example inserts an XML signature in the following XML:

    -- <?xml version="1.0" encoding="UTF-8" standalone="no"?>
    -- <abc>
    --   <xyz>
    --     <jpg>
    --         <name>starfish.jpg</name>
    --         <url>https://www.chilkatsoft.com/images/starfish.jpg</url>
    --     </jpg>
    --   </xyz>
    -- </abc>

    -- The above XML is available at https://www.chilkatsoft.com/exampleData/addSignatureToThis.xml
    -- First fetch the XML:

    DECLARE @url nvarchar(4000)
    SELECT @url = 'https://www.chilkatsoft.com/exampleData/addSignatureToThis.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, @url, @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

    -- We'll use an RSA private key for signing.  
    DECLARE @rsaKey int
    -- Use "Chilkat_9_5_0.PrivateKey" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.PrivateKey', @rsaKey OUT

    EXEC sp_OAMethod @rsaKey, 'LoadPemFile', @success OUT, 'qa_data/rsa/rsaPrivKey_pkcs8.pem'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @rsaKey, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @http
        EXEC @hr = sp_OADestroy @sbXml
        EXEC @hr = sp_OADestroy @rsaKey
        RETURN
      END

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

    -- Indicate were the Signature will be inserted:
    EXEC sp_OASetProperty @xmlSigGen, 'SigLocation', 'abc|xyz|jpg'

    -- Provide the RSA key to be used for signing:
    EXEC sp_OAMethod @xmlSigGen, 'SetPrivateKey', @success OUT, @rsaKey

    -- Fetch the JPG image data.
    DECLARE @jpgUrl nvarchar(4000)
    SELECT @jpgUrl = 'https://www.chilkatsoft.com/images/starfish.jpg'
    DECLARE @jpgData int
    -- Use "Chilkat_9_5_0.BinData" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.BinData', @jpgData OUT

    EXEC sp_OAMethod @http, 'QuickGetBd', @success OUT, @jpgUrl, @jpgData
    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 @rsaKey
        EXEC @hr = sp_OADestroy @xmlSigGen
        EXEC @hr = sp_OADestroy @jpgData
        RETURN
      END

    -- Add the external data reference:
    EXEC sp_OAMethod @xmlSigGen, 'AddExternalBinaryRef', @success OUT, @jpgUrl, @jpgData, 'sha256', ''

    -- Create the XML digital signature:
    EXEC sp_OAMethod @xmlSigGen, 'CreateXmlDSigSb', @success OUT, @sbXml
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @xmlSigGen, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @http
        EXEC @hr = sp_OADestroy @sbXml
        EXEC @hr = sp_OADestroy @rsaKey
        EXEC @hr = sp_OADestroy @xmlSigGen
        EXEC @hr = sp_OADestroy @jpgData
        RETURN
      END

    -- Examine the XML that now contains the Signature:
    EXEC sp_OAMethod @sbXml, 'GetAsString', @sTmp0 OUT
    PRINT @sTmp0

    -- <?xml version="1.0" encoding="UTF-8" standalone="no"?>
    -- <abc>
    --   <xyz>
    --     <jpg>
    --         <name>starfish.jpg</name>
    --         <url>https://www.chilkatsoft.com/images/starfish.jpg</url>
    --     <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#"/><ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#rsa-sha256"/><ds:Reference URI="https://www.chilkatsoft.com/images/starfish.jpg"><ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/><ds:DigestValue>AOU810yJV5Np/DnO29qpObqiTSTTCDvxGsX5ayiTYXI=</ds:DigestValue></ds:Reference></ds:SignedInfo><ds:SignatureValue>ApHRr6nilNrzt3dLveC9zlPoSllaCMfHsbAwr+vYBPkHkJ4wD5LzDDhi1tSJZAAeTckmvSqIG3Wi0rgXQiSM644MD3coBFx4QgrY+GZ+XJJE2Y0Ye3VvaQBiRdUW3INGsW4GLubncgQk5JhuAQjo6O/GKpfEuYqUJj/6CLHLQwMPwbZ2043ykgzuPFoOZf6EydJMBAn1ORMvrpUn+zuA9UngOTGap6eWE4CeiNx23BRC2wSztbUjdCLcqXvgiYu/v0tBNaTcwy7b6+IFtwv/lNUUBUQJ/3p+aErzFn3wLeH3yeqpDCU0U6Dqu5SS1jYupcWWsLHJjYnj2066DPJi/g==</ds:SignatureValue><ds:KeyInfo><ds:KeyValue><ds:RSAKeyValue><ds:Modulus>sXeRhM55P13FbpNcXAMR3olbw2Wa6keZIHu5YTZYUBTlYWId+pNiwUz3zFIEo+0IfYR0H27ybIycQO+1IIzJofUFNMAL3tZps2OKPlsjuCPls6kXpXhv/gvhux8LrCtp4PcKWqJ6QVOZKChc7WAx40qFWzHi57ueqRTv3x0kESqGg/VjsqyTEvb55psJO2RsfhLT7+YVh3hImRM3RDaJdkTkPuOxeFyT6N7VXD09329sLuS3QkUbE9zEKDnz9X3d8dEQdJhSI9ba5fxl8R7fu8pB67ElfzFml96X1jLFtzy1pzOT5Fc4ROcaqlYckVzdBq9sxezm6MYmDBjNAcibRw==</ds:Modulus><ds:Exponent>AQAB</ds:Exponent></ds:RSAKeyValue></ds:KeyValue></ds:KeyInfo></ds:Signature></jpg>
    --   </xyz>
    -- </abc>
    -- 

    EXEC @hr = sp_OADestroy @http
    EXEC @hr = sp_OADestroy @sbXml
    EXEC @hr = sp_OADestroy @rsaKey
    EXEC @hr = sp_OADestroy @xmlSigGen
    EXEC @hr = sp_OADestroy @jpgData


END
GO