キーを var に入れるだけの方がはるかに簡単です。
$public = "-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDfmlc2EgrdhvakQApmLCDOgP0n
NERInBheMh7J/r5aU8PUAIpGXET/8+kOGI1dSYjoux80AuHvkWp1EeHfMwC/SZ9t
6rF4sYqV5Lj9t32ELbh2VNbE/7QEVZnXRi5GdhozBZtS1gJHM2/Q+iToyh5dfTaA
U8bTnLEPMNC1h3qcUQIDAQAB
-----END PUBLIC KEY-----";
$private = "-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----";
if (!$privateKey = openssl_pkey_get_private($private)) die('Loading Private Key failed');
if (!$publicKey = openssl_pkey_get_public($public)) die('Loading Public Key failed');
小さなエンコード/デコードの例も含めます。
$encrypted = '';
$decrypted = '';
$plaintext = 'This is just some text to encrypt';
echo '<p>$plaintext = ' . $plaintext . '<p>';
if (!openssl_public_encrypt($plaintext, $encrypted, $publicKey)) die('Failed to encrypt data');
echo '<p>$encrypted = ' . $encrypted . '<p>';
if (!openssl_private_decrypt($encrypted, $decrypted, $privateKey)) die('Failed to decrypt data');
echo '<p>$decrypted = ' . $decrypted . '<p>';
または、php でキーを生成できる場合に備えて:
$NEW_KEY = openssl_pkey_new(array(
'private_key_bits' => 1024,
'private_key_type' => OPENSSL_KEYTYPE_RSA,
));
openssl_pkey_export_to_file($NEW_KEY, 'private.key');
$NEW_KEY_DETAILS = openssl_pkey_get_details($NEW_KEY);
file_put_contents('public.key', $NEW_KEY_DETAILS['key']);
openssl_free_key($NEW_KEY);