/**
* Decrypt using a private key
*
* @param string $msg
* @param string $privateKey
* @param string $passPhrase
* @param string $id
* @return string
* @throws RuntimeException
*/
public function decrypt($msg, $privateKey = null, $passPhrase = null, $id = null)
{
// get the session key
list($encKeys, $ciphertext) = explode(';', $msg, 2);
$keys = explode(':', $encKeys);
$pos = array_search(base64_encode($id), $keys);
if (false === $pos) {
throw new Exception\RuntimeException("This private key cannot be used for decryption");
}
if (!$privateKey instanceof PrivateKey && !is_string($privateKey)) {
throw new Exception\RuntimeException(sprintf("The private key must be a string in PEM format or an instance of %s", PrivateKey::class));
}
$privateKey = is_string($privateKey) ? new PrivateKey($privateKey, $passPhrase) : $privateKey;
// decrypt the session key with privateKey
$sessionKey = $this->rsa->decrypt(base64_decode($keys[$pos + 1]), $privateKey);
// decrypt the plaintext with the blockcipher algorithm
$this->bCipher->setKey($sessionKey);
return $this->bCipher->decrypt($ciphertext, $sessionKey);
}
public function testEncryptionUsingPrivateKeyBase64Encryption()
{
$rsa = new RSA(array('pemString' => $this->_testPemString));
$encrypted = $rsa->encrypt('1234567890', $rsa->getPrivateKey(), RSA::BASE64);
$this->assertEquals('1234567890', $rsa->decrypt($encrypted, $rsa->getPublicKey(), RSA::BASE64));
}
