Visual FoxPro

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. Visual FoxPro

LOCAL lnSuccess
LOCAL loEcc
LOCAL loFortuna
LOCAL lcEntropy
LOCAL loPrivKey
LOCAL loAsn
LOCAL loXml
LOCAL loCrypt
LOCAL lcPrivKeyHex

lnSuccess = 0

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

loEcc = 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.
loFortuna = CreateObject('Chilkat.Prng')
lcEntropy = loFortuna.GetEntropy(32,"base64")
lnSuccess = loFortuna.AddEntropy(lcEntropy,"base64")

loPrivKey = CreateObject('Chilkat.PrivateKey')
lnSuccess = loEcc.GenKey("secp256k1",loFortuna,loPrivKey)
IF (lnSuccess = 0) THEN
    ? loEcc.LastErrorText
    RELEASE loEcc
    RELEASE loFortuna
    RELEASE loPrivKey
    CANCEL
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('Chilkat.Asn')
lnSuccess = loAsn.LoadEncoded(loPrivKey.GetPkcs1ENC("base64"),"base64")
IF (lnSuccess <> 1) THEN
    ? loAsn.LastErrorText
    RELEASE loEcc
    RELEASE loFortuna
    RELEASE loPrivKey
    RELEASE loAsn
    CANCEL
ENDIF

loXml = CreateObject('Chilkat.Xml')
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('Chilkat.Crypt2')
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