PHP Requires Chilkat v11.0.0+

RSA Sign with PKCS8 Encrypted Key

See more RSA Examples

Demonstrates how to load a private key from an encrypted PKCS8 file and create an RSA digital signature (and then verify it). Chilkat2 PHP

<?php

use Chilkat2\Cert;
use Chilkat2\PrivateKey;
use Chilkat2\PublicKey;
use Chilkat2\Rsa;

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

$privKey = new PrivateKey();

// Load the private key from an RSA PEM file:
try {
    $privKey->LoadAnyFormatFile('raul_privateKey.key', 'a0123456789');

    $rsa = new Rsa();

    // Import the private key into the RSA component:
    $rsa->UsePrivateKey($privKey);

    // This example will sign a string, and receive the signature
    // in a hex-encoded string.  Therefore, set the encoding mode
    // to "hex":
    $rsa->EncodingMode = 'hex';

    $strData = 'This is the string to be signed.';

    // Sign the string using the sha256 hash algorithm.
    // Other valid choices are sha1, sha384, sha512 and others.
    $hexSig = $rsa->SignStringENC($strData, 'sha256');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

echo $hexSig, "\n";

// Now verify with the public key.
// This example shows how to use the public key from
// a digital certificate (.cer file)
$cert = new Cert();
try {
    $cert->LoadFromFile('raul_publicKey.cer');

    $pubKey = new PublicKey();
    $cert->GetPublicKey($pubKey);

    $rsa2 = new Rsa();
    $rsa2->UsePublicKey($pubKey);

    // Verify the signature against the original data:
    $rsa2->EncodingMode = 'hex';
    $rsa2->VerifyStringENC($strData, 'sha256', $hexSig);
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

echo "Signature verified!\n";

// Verify with incorrect data:
try {
    $rsa2->VerifyStringENC('something else', 'sha256', $hexSig);
    echo "Hmmm... that's not right...\n";
} catch (\Chilkat2\Exception $e) {
    echo "Signature not verified! (which was expected in this case)\n";
}