PHP

ECDSA Sign and Verify Data using Different Hash Algorithms

See more ECC Examples

Demonstrates how to create ECDSA signatures on data using different hash algorithms.

Note: This example requires Chilkat v9.5.0.85 or greater because the SignBd and VerifyBd methods were added in v9.5.0.85.

Chilkat2 PHP

<?php

use Chilkat2\BinData;
use Chilkat2\Ecc;
use Chilkat2\PrivateKey;
use Chilkat2\Prng;
use Chilkat2\PublicKey;

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

// First load an ECDSA private key to be used for signing.
$privKey = new PrivateKey();
try {
    $privKey->LoadEncryptedPemFile('qa_data/ecc/secp256r1-key-pkcs8-secret.pem', 'secret');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

// Load some data to be signed.
$bd = new BinData();
try {
    $bd->LoadFile('qa_data/hamlet.xml');
} catch (\Chilkat2\Exception $e) {
    echo "Failed to load file to be hashed.\n";
    exit;
}

$ecdsa = new Ecc();
$prng = new Prng();

// Sign the sha256 hash of the data.  Return the ECDSA signature in the base64 encoding.
echo "ECDSA signing the sha256 hash of the data...\n";
$sig = $ecdsa->SignBd($bd, 'sha256', 'base64', $privKey, $prng);
echo 'sig = ', $sig, "\n";

// Verify the signature against the original data.
// (We must use the same hash algorithm that was used when signing.)

// Load the public key that corresponds to the private key used for signing.
$pubKey = new PublicKey();
try {
    $pubKey->LoadFromFile('qa_data/ecc/secp256r1-pub.pem');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

$ecc2 = new Ecc();
$result = $ecc2->VerifyBd($bd, 'sha256', $sig, 'base64', $pubKey);
if ($result != 1) {
    echo $ecc2->LastErrorText, "\n";
    exit;
}

echo "Verified!\n";

// ----------------------------------------------------------------------------------------
// Let's do the same thing, but with sha384 hashing...

echo "--------------------------------------------\n";
echo "ECDSA signing the sha384 hash of the data...\n";

$sig = $ecdsa->SignBd($bd, 'sha384', 'base64', $privKey, $prng);
echo 'sig = ', $sig, "\n";

$result = $ecc2->VerifyBd($bd, 'sha384', $sig, 'base64', $pubKey);
if ($result != 1) {
    echo $ecc2->LastErrorText, "\n";
    exit;
}

echo "Verified!\n";