Lua

Canonicalize XML Fragment

See more XML Digital Signatures Examples

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). Lua

local chilkat = require("chilkat")

-- This example requires the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.

local http = chilkat.Http.new()
local sbXml = chilkat.StringBuilder.new()
local canon = chilkat.XmlDSig.new()

-- Use exclusive XML canonicalization.
local canonVersion = "EXCL_C14N"
local withComments = false
-- The optional inclusive namespaces prefix list if using exclusive canonicalization.
local prefixList = ""

local url = "https://www.chilkatsoft.com/exampleData/canonicalizeFragmentTest.xml"
local success = http:quick_get_sb(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".
local xmlCanonFrag = canon:canonicalize_fragment(sbXml:get_as_string(), "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>
--