PHP ActiveX

RSA Encrypt Bytes to Base64 and Reverse

See more RSA Examples

Demonstrates how to RSA encrypt bytes to base64 and the reverse. PHP ActiveX

<?php

$success = 0;

// The RSA public key is used for encryption, and the private key for decryption.

// The public key's role is to make encryption accessible to anyone while ensuring that
// only the private key holder can decrypt the messages.
// The public key is designed to be widely distributed so anyone can use it to encrypt messages
// intended for the owner of the private key.

// Load our 2048-bit RSA public key.
$pubKey = new COM("Chilkat.PublicKey");
// In all Chilkat methods expecting a path, you pass either absolute or relative paths.
$success = $pubKey->LoadFromFile('qa_data/rsaKeys/myTestRsaPublic.pem');
if ($success == 0) {
    print $pubKey->LastErrorText . "\n";
    exit;
}

$rsa = new COM("Chilkat.Rsa");

// Tell RSA to use the public key.
$rsa->UsePublicKey($pubKey);

// RSA encryption is for small amounts of data, on the order of 200 bytes or less.
// The maximum number of bytes that can be RSA encrypted depends
// on the RSA key size and padding scheme (OAEP padding vs PKCS#1 v1.5 padding).
// For specific limits, see: RSA Encryption Maximum Number of Bytes

// A typical use for RSA is to encrypt symmetric encryption keys, such as an AES key.
$prng = new COM("Chilkat.Prng");

$keyBytes = $prng->GenRandomBytes(32);

$rsa->EncodingMode = 'base64';
$encryptedB64 = $rsa->encryptBytesENC($keyBytes,0);

print 'Result:' . "\n";
print $encryptedB64 . "\n";

// Sample output:
// hTTV4Lbmm2V7NCw/HaoJL8Aq/MM/HXblQnjitrF9HY1zBlISwui2jGVVZDtZcZ/rICOpPw44w8Qb8AswFVE1sryydmNEvcIfYAp/xgdBPXBERAS0y4AoEzUfuC5TJmJFvnFkl2lX8GAclANfcTik38V+k3EXu5wPzHKNFb07c6jnwh3Jm4f3PRUhmmB2NO5kSWqHsx0dNglOTq5BUZx34nxlXL5G8d7mXqITsUtrOHXAO/Gb7IrvB81Xk2vc5p4yHhiY/rFTHTTmZyzte2qHGm7V6xPRNURjiivnMY2jQU0Um1JKQcAiSe8Suwvd2LXP5PIhl71VLgO+fokjnynfRg==

// ------------------------------------------------------------------------------------------------------------------------
// Let's decrypt, which requires the matching private key...

// Load the matching 2048-bit RSA private key.
$privKey = new COM("Chilkat.PrivateKey");
$password = 'secret';
$success = $privKey->LoadAnyFormatFile('qa_data/rsaKeys/myTestRsaPrivate.pem',$password);
if ($success == 0) {
    print $privKey->LastErrorText . "\n";
    exit;
}

// Tell the RSA object to use the private key.
$rsa->UsePrivateKey($privKey);

$decBytes = $rsa->DecryptBytesENC($encryptedB64,1);
if ($success == 0) {
    print $rsa->LastErrorText . "\n";
    exit;
}

print 'Success.' . "\n";

?>