PHP Requires Chilkat v11.0.0+

Duplicate openssl dgst -md5 -sign myKey.pem something.txt | openssl enc -base64 -A

See more RSA Examples

Demonstrates how to duplicate the creation of an RSA signature produced by this OpenSSL command:

openssl dgst -md5 -sign myKey.pem something.txt | openssl enc -base64 -A

Chilkat2 PHP

<?php

use Chilkat2\PrivateKey;
use Chilkat2\Rsa;

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

$pkey = new PrivateKey();

// Load the private key from an RSA PEM file:
$pkey->LoadPemFile('myKey.pem');

$rsa = new Rsa();

// Import the private key into the RSA component:
try {
    $rsa->UsePrivateKey($pkey);
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

// OpenSSL uses BigEndian byte ordering:
$rsa->LittleEndian = false;

// The resulting signature will be a Base64 string:
$rsa->EncodingMode = 'base64';

// For simplicity, we're not loading
// the data to be signed from a file.  We are instead simply
// using a literal string value.
$strData = 'This is the text to be signed.';

// Hash the input using MD5, and then sign the hash:
// Other valid hash algorithm choices are "md2" and "sha-1".
$base64Sig = $rsa->SignStringENC($strData, 'md5');

echo $base64Sig, "\n";

echo "Success!\n";