PHP ActiveX Requires Chilkat v11.0.0+

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. PHP ActiveX

<?php

$success = 0;

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

$ecc = new COM("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.
$fortuna = new COM("Chilkat.Prng");
$entropy = $fortuna->getEntropy(32,'base64');
$success = $fortuna->AddEntropy($entropy,'base64');

$privKey = new COM("Chilkat.PrivateKey");
$success = $ecc->GenKey('secp256k1',$fortuna,$privKey);
if ($success == 0) {
    print $ecc->LastErrorText . "\n";
    exit;
}

//  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.)

$asn = new COM("Chilkat.Asn");
$success = $asn->LoadEncoded($privKey->getPkcs1ENC('base64'),'base64');
if ($success != 1) {
    print $asn->LastErrorText . "\n";
    exit;
}

$xml = new COM("Chilkat.Xml");
$xml->LoadXml($asn->asnToXml());

print $xml->getXml() . "\n";

//  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.
$crypt = new COM("Chilkat.Crypt2");
$privKeyHex = $crypt->reEncode($xml->getChildContent('octets'),'base64','hex');

print 'EC private key as hex = ' . $privKeyHex . "\n";

?>