function getRandomCiphertext($key, $iv)
{
$texts = ['MDAwMDAwTm93IHRoYXQgdGhlIHBhcnR5IGlzIGp1bXBpbmc=', 'MDAwMDAxV2l0aCB0aGUgYmFzcyBraWNrZWQgaW4gYW5kIHRoZSBWZWdhJ3MgYXJlIHB1bXBpbic=', 'MDAwMDAyUXVpY2sgdG8gdGhlIHBvaW50LCB0byB0aGUgcG9pbnQsIG5vIGZha2luZw==', 'MDAwMDAzQ29va2luZyBNQydzIGxpa2UgYSBwb3VuZCBvZiBiYWNvbg==', 'MDAwMDA0QnVybmluZyAnZW0sIGlmIHlvdSBhaW4ndCBxdWljayBhbmQgbmltYmxl', 'MDAwMDA1SSBnbyBjcmF6eSB3aGVuIEkgaGVhciBhIGN5bWJhbA==', 'MDAwMDA2QW5kIGEgaGlnaCBoYXQgd2l0aCBhIHNvdXBlZCB1cCB0ZW1wbw==', 'MDAwMDA3SSdtIG9uIGEgcm9sbCwgaXQncyB0aW1lIHRvIGdvIHNvbG8=', 'MDAwMDA4b2xsaW4nIGluIG15IGZpdmUgcG9pbnQgb2g=', 'MDAwMDA5aXRoIG15IHJhZy10b3AgZG93biBzbyBteSBoYWlyIGNhbiBibG93'];
$texts = array_map('base64_decode', $texts);
$text = $texts[rand(0, 9)];
// our implementation automatically PKCS7 pads
return encryptAES128CBC($text, $key, $iv);
}
function randomlyEncryptECBorCBC($data)
{
$key = getRandomBytes(16);
$pad1 = getRandomBytes(rand(5, 10));
$pad2 = getRandomBytes(rand(5, 10));
if (rand(0, 1)) {
return encryptAES128CBC("{$pad1}{$data}{$pad2}", $key, getRandomBytes(16));
}
return encryptAES128ECB("{$pad1}{$data}{$pad2}", $key);
}
function getQuery($userData, $key, $iv)
{
$data = http_build_query(['comment1' => 'cooking MCs', 'userdata' => $userData, 'comment2' => ' lke a pound of bacon'], null, ';', PHP_QUERY_RFC3986);
return encryptAES128CBC($data, $key, $iv);
}
function decryptAES128CBC($data, $key, $iv = "", $strictPadding = false)
{
$blocks = str_split($data, 16);
foreach ($blocks as &$block) {
$nextIV = $block;
$block = $iv ^ _decryptAES128ECB($block, $key);
$iv = $nextIV;
}
$plaintext = implode($blocks);
try {
return removePKCS7Padding($plaintext);
} catch (Exception $e) {
if ($strictPadding) {
throw $e;
}
return $plaintext;
}
}
// don't output if we're included into another script.
if (!debug_backtrace()) {
$encrypted = base64_decode(file_get_contents('10-data.txt'));
$key = 'YELLOW SUBMARINE';
$decrypted = decryptAES128CBC($encrypted, $key);
$homebrewEncrypted = encryptAES128CBC($decrypted, $key);
$homebrewDecrypted = decryptAES128CBC($homebrewEncrypted, $key);
print "Sanity check:\n";
$sanity = $decrypted === $homebrewDecrypted;
print $sanity ? "Success!\n\n" : "Failure :(\n\n";
print "Decrypted data:\n";
print "{$decrypted}\n";
}
function send($data)
{
$key = sha1($this->shared, true);
$iv = getRandomBytes(16);
$message = $iv . encryptAES128CBC($data, $key, $iv);
print "{$this->name}: sending: {$data}\n";
$func = $this->onSend;
$func($message);
}
function send($data)
{
$obj = new \stdClass();
$obj->msg = 'dat';
$obj->data = $data;
$data = json_encode($obj);
if (!is_null($this->shared)) {
$key = sha1($this->shared, true);
$iv = getRandomBytes(16);
$data = $iv . encryptAES128CBC($data, $key, $iv);
}
$dataLen = strlen($data);
print "{$this->name}: sending {$dataLen} bytes\n";
$func = $this->onSend;
$func($data);
}