(Ruby) SII Chile - FRMA Signature Computation and Add to XML

Compute the FRMA signature of a <DA> element enclosed inside a <CAF> element of the XML to be signed.

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

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

# Also see:  Compute the FRMT Signature and Add to XML

xml = Chilkat::CkXml.new()

# Load the unsigned XML that contains the following:

# <DTE version="1.0">
#   <Documento ID="F60T33">
#         <TED version="1.0">
#             <DD>
# 		...
#                 <CAF version="1.0">
#                     <DA>
# 			...
#                     </DA>
# 			... The FRMA will be added here ...
#                 </CAF>
#                 ...
#             </DD>
#             ... The FRMT will be added here in another example ...
#         </TED>
#   </Documento>
# </DTE>

success = xml.LoadXmlFile("qa_data/xml_dsig/sii_cl/test_0.xml")
if (success == false)
    print "Failed to load initial XML file." + "\n";
    exit
end

# Get a reference to the "DA" element
# daXml is a CkXml
daXml = xml.FindChild("Documento|TED|DD|CAF|DA")
if (xml.get_LastMethodSuccess() == false)
    print "Failed to find DA element" + "\n";
    exit
end

#  We need to get the "flattened" DA XML where:
#    - No whitespace between elements.
#    - The 5 pre-defined entities are converted.
#    - The text is encoded in the ISO-8859-1 character set (Latin-1), 
sbFlattened = Chilkat::CkStringBuilder.new()
daXml.put_EmitCompact(true)
daXml.put_EmitXmlDecl(false)
daXml.GetXmlSb(sbFlattened)

# Compute the SHA-1 message digest of the iso-8859-1 byte representation, 
# and sign it with our RSA private key, getting the result in base64 format.

privKey = Chilkat::CkPrivateKey.new()
success = privKey.LoadAnyFormatFile("qa_data/rsa/rsaPrivKey_pkcs8.pem","")
if (success == false)
    print privKey.lastErrorText() + "\n";
    exit
end

rsa = Chilkat::CkRsa.new()
rsa.ImportPrivateKeyObj(privKey)

rsa.put_EncodingMode("base64")
rsa.put_Charset("iso-8859-1")
sig = rsa.signStringENC(sbFlattened.getAsString(),"sha1")

# Add the FRMA signature element to the XML.
xml.UpdateChildContent("Documento|TED|DD|CAF|FRMA",sig)
xml.UpdateAttrAt("Documento|TED|DD|CAF|FRMA",true,"algoritmo","SHA1withRSA")

# See what we have:
xml.put_EmitCompact(false)
xml.put_EmitXmlDecl(true)
print xml.getXml() + "\n";

xml.SaveXml("qa_data/xml_dsig/sii_cl/test_1.xml")