(Classic ASP) Generate ECDSA Key and Get Details as XML

Demonstrates how to generate an ECDSA key and gets the parts as XML.

Note: This example requires Chilkat v11.0.0 or greater.

Chilkat ActiveX Downloads

ActiveX for 32-bit and 64-bit Windows

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
' This requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

set ecc = Server.CreateObject("Chilkat.Ecc")

' Generate a random ECC private key on the secp256k1 curve.
' Chilkat also supports other curves, such as secp384r1, secp521r1, and secp256r1.

' Create a Fortuna PRNG and seed it with system entropy.
' This will be our source of random data for generating the ECC private key.
set fortuna = Server.CreateObject("Chilkat.Prng")
entropy = fortuna.GetEntropy(32,"base64")
success = fortuna.AddEntropy(entropy,"base64")

set privKey = Server.CreateObject("Chilkat.PrivateKey")
success = ecc.GenKey("secp256k1",fortuna,privKey)
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( ecc.LastErrorText) & "</pre>"
    Response.End
End If

' An EC private key has this ASN.1
' ECPrivateKey ::= SEQUENCE {
'     version        INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
'     privateKey     OCTET STRING,
'     parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
'     publicKey  [1] BIT STRING OPTIONAL (This is the ANSI X9.63 public key format.)

set asn = Server.CreateObject("Chilkat.Asn")
success = asn.LoadEncoded(privKey.GetPkcs1ENC("base64"),"base64")
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( asn.LastErrorText) & "</pre>"
    Response.End
End If

set xml = Server.CreateObject("Chilkat.Xml")
success = xml.LoadXml(asn.AsnToXml())

Response.Write "<pre>" & Server.HTMLEncode( xml.GetXml()) & "</pre>"

' The XML looks like this:
' <?xml version="1.0" encoding="utf-8" ?>
' <sequence>
'     <int>01</int>
'     <octets>JgJvBG+3wletkJab8iXAkpz0O8/AgWZSpkYVcB7SpnU=</octets>
'     <contextSpecific tag="0" constructed="1">
'         <oid>1.3.132.0.10</oid>
'     </contextSpecific>
' </sequence>

' The 32-byte private key is in the octets..
' Get it as hex.
set crypt = Server.CreateObject("Chilkat.Crypt2")
privKeyHex = crypt.ReEncode(xml.GetChildContent("octets"),"base64","hex")

Response.Write "<pre>" & Server.HTMLEncode( "EC private key as hex = " & privKeyHex) & "</pre>"

%>
</body>
</html>