Xojo Plugin

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. Xojo Plugin

Dim success As Boolean
success = 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
    System.DebugLog("Failed to load initial XML file.")
    Return
End If

// Get a reference to the "DD" element
Dim ddXml As Chilkat.Xml
ddXml = xml.FindChild("Documento|TED|DD")
If (xml.LastMethodSuccess = False) Then
    System.DebugLog("Failed to find DD element")
    Return
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
success = 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
    System.DebugLog(privKey.LastErrorText)
    Return
End If

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

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

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

// See what we have:
xml.EmitCompact = False
xml.EmitXmlDecl = True
System.DebugLog(xml.GetXml())