Lianja

Generate ECDSA Key and Get Details as XML

See more ECC Examples

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

llSuccess = .F.

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

loEcc = createobject("CkEcc")

// 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.
loFortuna = createobject("CkPrng")
lcEntropy = loFortuna.GetEntropy(32,"base64")
llSuccess = loFortuna.AddEntropy(lcEntropy,"base64")

loPrivKey = createobject("CkPrivateKey")
llSuccess = loEcc.GenKey("secp256k1",loFortuna,loPrivKey)
if (llSuccess = .F.) then
    ? loEcc.LastErrorText
    release loEcc
    release loFortuna
    release loPrivKey
    return
endif

// 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.)

loAsn = createobject("CkAsn")
llSuccess = loAsn.LoadEncoded(loPrivKey.GetPkcs1ENC("base64"),"base64")
if (llSuccess <> .T.) then
    ? loAsn.LastErrorText
    release loEcc
    release loFortuna
    release loPrivKey
    release loAsn
    return
endif

loXml = createobject("CkXml")
loXml.LoadXml(loAsn.AsnToXml())

? loXml.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.
loCrypt = createobject("CkCrypt2")
lcPrivKeyHex = loCrypt.ReEncode(loXml.GetChildContent("octets"),"base64","hex")

? "EC private key as hex = " + lcPrivKeyHex


release loEcc
release loFortuna
release loPrivKey
release loAsn
release loXml
release loCrypt