Classic ASP
Create XML Signature with External Data Reference

See more XML Digital Signatures Examples
Demonstrates how to create an XML digital signature where the data is external. In this case, the data is a JPG file.
This example requires Chilkat v9.5.0.69 or greater.
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Classic ASP
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
success = 0

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

' This example inserts an XML signature in the following XML:

' <?xml version="1.0" encoding="UTF-8" standalone="no"?>
' <abc>
'   <xyz>
'     <jpg>
'         <name>starfish.jpg</name>
'         <url>https://www.chilkatsoft.com/images/starfish.jpg</url>
'     </jpg>
'   </xyz>
' </abc>

' The above XML is available at https://www.chilkatsoft.com/exampleData/addSignatureToThis.xml
' First fetch the XML:

url = "https://www.chilkatsoft.com/exampleData/addSignatureToThis.xml"
set http = Server.CreateObject("Chilkat.Http")
set sbXml = Server.CreateObject("Chilkat.StringBuilder")
success = http.QuickGetSb(url,sbXml)
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( http.LastErrorText) & "</pre>"
    Response.End
End If

' We'll use an RSA private key for signing.  
set rsaKey = Server.CreateObject("Chilkat.PrivateKey")
success = rsaKey.LoadPemFile("qa_data/rsa/rsaPrivKey_pkcs8.pem")
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( rsaKey.LastErrorText) & "</pre>"
    Response.End
End If

set xmlSigGen = Server.CreateObject("Chilkat.XmlDSigGen")

' Indicate were the Signature will be inserted:
xmlSigGen.SigLocation = "abc|xyz|jpg"

' Provide the RSA key to be used for signing:
success = xmlSigGen.SetPrivateKey(rsaKey)

' Fetch the JPG image data.
jpgUrl = "https://www.chilkatsoft.com/images/starfish.jpg"
set jpgData = Server.CreateObject("Chilkat.BinData")
success = http.QuickGetBd(jpgUrl,jpgData)
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( http.LastErrorText) & "</pre>"
    Response.End
End If

' Add the external data reference:
success = xmlSigGen.AddExternalBinaryRef(jpgUrl,jpgData,"sha256","")

' Create the XML digital signature:
success = xmlSigGen.CreateXmlDSigSb(sbXml)
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( xmlSigGen.LastErrorText) & "</pre>"
    Response.End
End If

' Examine the XML that now contains the Signature:
Response.Write "<pre>" & Server.HTMLEncode( sbXml.GetAsString()) & "</pre>"

' <?xml version="1.0" encoding="UTF-8" standalone="no"?>
' <abc>
'   <xyz>
'     <jpg>
'         <name>starfish.jpg</name>
'         <url>https://www.chilkatsoft.com/images/starfish.jpg</url>
'     <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#"><ds:SignedInfo><ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/><ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#rsa-sha256"/><ds:Reference URI="https://www.chilkatsoft.com/images/starfish.jpg"><ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/><ds:DigestValue>AOU810yJV5Np/DnO29qpObqiTSTTCDvxGsX5ayiTYXI=</ds:DigestValue></ds:Reference></ds:SignedInfo><ds:SignatureValue>ApHRr6nilNrzt3dLveC9zlPoSllaCMfHsbAwr+vYBPkHkJ4wD5LzDDhi1tSJZAAeTckmvSqIG3Wi0rgXQiSM644MD3coBFx4QgrY+GZ+XJJE2Y0Ye3VvaQBiRdUW3INGsW4GLubncgQk5JhuAQjo6O/GKpfEuYqUJj/6CLHLQwMPwbZ2043ykgzuPFoOZf6EydJMBAn1ORMvrpUn+zuA9UngOTGap6eWE4CeiNx23BRC2wSztbUjdCLcqXvgiYu/v0tBNaTcwy7b6+IFtwv/lNUUBUQJ/3p+aErzFn3wLeH3yeqpDCU0U6Dqu5SS1jYupcWWsLHJjYnj2066DPJi/g==</ds:SignatureValue><ds:KeyInfo><ds:KeyValue><ds:RSAKeyValue><ds:Modulus>sXeRhM55P13FbpNcXAMR3olbw2Wa6keZIHu5YTZYUBTlYWId+pNiwUz3zFIEo+0IfYR0H27ybIycQO+1IIzJofUFNMAL3tZps2OKPlsjuCPls6kXpXhv/gvhux8LrCtp4PcKWqJ6QVOZKChc7WAx40qFWzHi57ueqRTv3x0kESqGg/VjsqyTEvb55psJO2RsfhLT7+YVh3hImRM3RDaJdkTkPuOxeFyT6N7VXD09329sLuS3QkUbE9zEKDnz9X3d8dEQdJhSI9ba5fxl8R7fu8pB67ElfzFml96X1jLFtzy1pzOT5Fc4ROcaqlYckVzdBq9sxezm6MYmDBjNAcibRw==</ds:Modulus><ds:Exponent>AQAB</ds:Exponent></ds:RSAKeyValue></ds:KeyValue></ds:KeyInfo></ds:Signature></jpg>
'   </xyz>
' </abc>
' 

%>
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