(VB.NET) Generate ECDSA Key and Get Details as XML

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

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

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

Dim ecc As New 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.
Dim fortuna As New Chilkat.Prng
Dim entropy As String = fortuna.GetEntropy(32,"base64")
Dim success As Boolean = fortuna.AddEntropy(entropy,"base64")

Dim privKey As Chilkat.PrivateKey = ecc.GenEccKey("secp256k1",fortuna)
If (ecc.LastMethodSuccess <> True) Then
    Debug.WriteLine(ecc.LastErrorText)
    Exit Sub
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.)


Dim asn As New Chilkat.Asn
success = asn.LoadEncoded(privKey.GetPkcs1ENC("base64"),"base64")
If (success <> True) Then
    Debug.WriteLine(asn.LastErrorText)
    Exit Sub
End If


Dim xml As New Chilkat.Xml
xml.LoadXml(asn.AsnToXml())

Debug.WriteLine(xml.GetXml())

'  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.
Dim crypt As New Chilkat.Crypt2
Dim privKeyHex As String = crypt.ReEncode(xml.GetChildContent("octets"),"base64","hex")

Debug.WriteLine("EC private key as hex = " & privKeyHex)