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VB.NET Requires Chilkat v11.0.0+

SII Chile - FRMT Signature Computation and Add to XML

See more XML Digital Signatures Examples

Compute the FRMT signature and add to the XML. This is the RSA signature of the SHA-1 digest of the "flattened" DD element.

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VB.NET
Dim success As Boolean = False

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

'  Also see:  Compute the FRMA Signature and Add to XML

Dim xml As New Chilkat.Xml

'  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>
'                      <FRMA algoritmo="SHA1withRSA">...</FRMA>
'                  </CAF>
'                  ...
'              </DD>
'              ... The FRMT will be added here in another example ...
'          </TED>
'    </Documento>
'  </DTE>

success = xml.LoadXmlFile("qa_data/xml_dsig/sii_cl/test_1.xml")
If (success = False) Then
    Debug.WriteLine("Failed to load initial XML file.")
    Exit Sub
End If


'  Get a reference to the "DD" element
Dim ddXml As Chilkat.Xml = xml.FindChild("Documento|TED|DD")
If (xml.LastMethodSuccess = False) Then
    Debug.WriteLine("Failed to find DD element")
    Exit Sub
End If


'   We need to get the "flattened" DD 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), 
Dim sbFlattened As New Chilkat.StringBuilder
ddXml.EmitCompact = True
ddXml.EmitXmlDecl = False
ddXml.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.

Dim privKey As New Chilkat.PrivateKey
success = privKey.LoadAnyFormatFile("qa_data/rsa/rsaPrivKey_pkcs8.pem","")
If (success = False) Then
    Debug.WriteLine(privKey.LastErrorText)
    Exit Sub
End If


Dim rsa As New Chilkat.Rsa
rsa.UsePrivateKey(privKey)

rsa.EncodingMode = "base64"
rsa.Charset = "iso-8859-1"
Dim sig As String = rsa.SignStringENC(sbFlattened.GetAsString(),"sha1")

'  Add the FRMT signature element to the XML.
xml.UpdateChildContent("Documento|TED|FRMT",sig)
xml.UpdateAttrAt("Documento|TED|FRMT",True,"algoritmo","SHA1withRSA")



'  See what we have:
xml.EmitCompact = False
xml.EmitXmlDecl = True
Debug.WriteLine(xml.GetXml())