(SQL Server) Canonicalize XML Fragment

Demonstrates how to canonicalize a fragment of an XML document. The fragment is identified by the element having an Id attribute equal to a specified value. (The Id attribute can have any namespace, and the attribute name is case-insensitive (thus "ID", "Id", "id", etc. match).

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.

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

    -- Use exclusive XML canonicalization.
    DECLARE @canonVersion nvarchar(4000)
    SELECT @canonVersion = 'EXCL_C14N'
    DECLARE @withComments int
    SELECT @withComments = 0
    -- The optional inclusive namespaces prefix list if using exclusive canonicalization.
    DECLARE @prefixList nvarchar(4000)
    SELECT @prefixList = ''

    DECLARE @url nvarchar(4000)
    SELECT @url = 'https://www.chilkatsoft.com/exampleData/canonicalizeFragmentTest.xml'
    DECLARE @success int
    EXEC sp_OAMethod @http, 'QuickGetSb', @success OUT, @url, @sbXml

    -- This is the input XML:

    -- <?xml version="1.0" encoding="UTF-8"?>
    -- <Signature xmlns="http://www.w3.org/2000/09/xmldsig#">
    -- <SignedInfo>
    --   <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" />
    --   <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" />
    --   <Reference URI="#object">
    --     <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" />
    --     <DigestValue>OPnpF/ZNLDxJ/I+1F3iHhlmSwgo=</DigestValue>
    --   </Reference>
    -- </SignedInfo>
    -- <SignatureValue>nihUFQg4mDhLgecvhIcKb9Gz8VRTOlw+adiZOBBXgK4JodEe5aFfCqm8WcRIT8GL
    -- LXSk8PsUP4//SsKqUBQkpotcAqQAhtz2v9kCWdoUDnAOtFZkd/CnsZ1sge0ndha4
    -- 0wWDV+nOWyJxkYgicvB8POYtSmldLLepPGMz+J7/Uws=</SignatureValue>
    -- <KeyInfo>
    --   <KeyValue>
    --     <RSAKeyValue>
    --       <Modulus>4IlzOY3Y9fXoh3Y5f06wBbtTg94Pt6vcfcd1KQ0FLm0S36aGJtTSb6pYKfyX7PqC
    --       UQ8wgL6xUJ5GRPEsu9gyz8ZobwfZsGCsvu40CWoT9fcFBZPfXro1Vtlh/xl/yYHm
    --       +Gzqh0Bw76xtLHSfLfpVOrmZdwKmSFKMTvNXOFd0V18=</Modulus>
    --       <Exponent>AQAB</Exponent>
    --     </RSAKeyValue>
    --   </KeyValue>
    -- </KeyInfo>
    -- <Object Id="object">some text
    --   with spaces and CR-LF.</Object>
    -- </Signature>

    -- Canonicalize and return the fragment of XML starting at the element where the Id attribute equals "object".
    DECLARE @xmlCanonFrag nvarchar(4000)
    EXEC sp_OAMethod @sbXml, 'GetAsString', @sTmp0 OUT
    EXEC sp_OAMethod @canon, 'CanonicalizeFragment', @xmlCanonFrag OUT, @sTmp0, 'object', @canonVersion, @prefixList, @withComments

    PRINT @xmlCanonFrag

    -- The output is:
    -- 
    -- <Object xmlns="http://www.w3.org/2000/09/xmldsig#" Id="object">some text
    --   with spaces and CR-LF.</Object>
    -- 

    EXEC @hr = sp_OADestroy @http
    EXEC @hr = sp_OADestroy @sbXml
    EXEC @hr = sp_OADestroy @canon


END
GO