(PHP Extension) Duplicate openssl dgst -sha256 -verify pubKey.pem -signature signature.sig in.dat

Demonstrates how to duplicate this OpenSSL command:

openssl dgst -sha256 -verify pubKey.pem -signature signature.sig in.dat

1. Creates a SHA256 digest of the contents of the input file.
2. Verifies the SHA256 digest using the public key.

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

<?php

include("chilkat.php");
// Use "chilkat_9_5_0.php" for versions of Chilkat < 10.0.0

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

$pubKey = new CkPublicKey();

// Load the public key from an PEM file:
$success = $pubKey->LoadFromFile('pubKey.pem');
if ($success != true) {
    print $pubKey->lastErrorText() . "\n";
    exit;
}

// Load the data of the original file that was signed.
$bdFileData = new CkBinData();
$success = $bdFileData->LoadFile('in.dat');

// Load the signature.
$bdSig = new CkBinData();
$success = $bdSig->LoadFile('signature.sig');

$rsa = new CkRsa();

// Import the public key into the RSA component:
$success = $rsa->ImportPublicKeyObj($pubKey);
if ($success != true) {
    print $rsa->lastErrorText() . "\n";
    exit;
}

// OpenSSL uses big-endian.
$rsa->put_LittleEndian(false);

$success = $rsa->VerifyBd($bdFileData,'sha256',$bdSig);
if ($success != true) {
    print $rsa->lastErrorText() . "\n";
    print 'The signature was invalid.' . "\n";
    exit;
}

print 'The signature was verified.' . "\n";

?>