(PHP Extension) Get an EC Key in Raw Hex Format

Demonstrates how to get the private and public key parts of an EC (ECDSA) key in lowercase hex formmat.

Note: This example requires Chilkat v9.5.0.83 or greater.

Chilkat PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?php

// The version number (9_5_0) should match version of the Chilkat extension used, omitting the micro-version number.
// For example, if using Chilkat v9.5.0.48, then include as shown here:
include("chilkat_9_5_0.php");

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

// Load an EC key from some format..
$privKey = new CkPrivateKey();

// This loads an ECDSA key from an unencrypted PEM file (no password required).
$success = $privKey->LoadAnyFormatFile('qa_data/ecc/openssl_ecc_privKey.pem','');
if ($success == false) {
    print $privKey->lastErrorText() . "\n";
    exit;
}

// The key type should be "ecc" to indicate an EC key.
print 'key type = ' . $privKey->keyType() . "\n";

// What is the size of the private key in bits?
print 'size in bits = ' . $privKey->get_BitLength() . "\n";

// Get the private and public EC key parts in raw hex format:
$sbPubKeyHex = new CkStringBuilder();
$privKeyHex = $privKey->getRawHex($sbPubKeyHex);

// If the private key size in bits is 256, then we should have a 32-byte key (a 64 character hex string).
print 'private key = ' . $privKeyHex . "\n";

// The public key is composed of the "x" and "y" parts, and is composed like this:  04||HEX(x)||HEX(y)
print 'public key = ' . $sbPubKeyHex->getAsString() . "\n";

// Sample output:
// key type = ecc
// size in bits = 256
// private key = ced36f2ba3332be439f79143d69937fc52494cd38e45243c3ea05db183919f1b
// public key = 045b4edcd501831740895f5907feabb71587076a6314d9d5141f9f8c33a478b8ce08b8dfd2a091eb6355803d7e729876c790bc0b176f2015f3bb103813753f676a

?>