PHP Extension

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 Extension

<?php

include("chilkat.php");

$success = false;

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

$ecc = new 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.
$fortuna = new CkPrng();
$entropy = $fortuna->getEntropy(32,'base64');
$success = $fortuna->AddEntropy($entropy,'base64');

$privKey = new CkPrivateKey();
$success = $ecc->GenKey('secp256k1',$fortuna,$privKey);
if ($success == false) {
    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 CkAsn();
$success = $asn->LoadEncoded($privKey->getPkcs1ENC('base64'),'base64');
if ($success != true) {
    print $asn->lastErrorText() . "\n";
    exit;
}

$xml = new CkXml();
$xml->LoadXml($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 CkCrypt2();
$privKeyHex = $crypt->reEncode($xml->getChildContent('octets'),'base64','hex');

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

?>