web-base/core/Objects/AesStream.class.php
2021-12-08 16:54:53 +01:00

106 lines
2.5 KiB
PHP

<?php
namespace Objects;
class AesStream {
private string $key;
private string $iv;
private $callback;
private ?string $outputFile;
private ?string $inputFile;
public function __construct(string $key, string $iv) {
$this->key = $key;
$this->iv = $iv;
$this->inputFile = null;
$this->outputFile = null;
$this->callback = null;
if (!in_array(strlen($key), [16, 24, 32])) {
throw new \Exception("Invalid Key Size");
} else if (strlen($iv) !== 16) {
throw new \Exception("Invalid IV Size");
}
}
public function setInputFile(string $file) {
$this->inputFile = $file;
}
public function setOutput(callable $callback) {
$this->callback = $callback;
}
public function setOutputFile(string $file) {
$this->outputFile = $file;
}
public function start(): bool {
if (!$this->inputFile) {
return false;
}
$blockSize = 16;
$aesMode = $this->getCipherMode();
$outputHandle = null;
$inputHandle = fopen($this->inputFile, "rb");
if (!$inputHandle) {
return false;
}
if ($this->outputFile !== null) {
$outputHandle = fopen($this->outputFile, "wb");
if (!$outputHandle) {
fclose($inputHandle);
return false;
}
}
set_time_limit(0);
$ivCounter = $this->iv;
$modulo = \gmp_init("0x1" . str_repeat("00", $blockSize), 16);
while (!feof($inputHandle)) {
$chunk = fread($inputHandle, 65536);
$chunkSize = strlen($chunk);
if ($chunkSize > 0) {
$blockCount = intval(ceil($chunkSize / $blockSize));
$encrypted = openssl_encrypt($chunk, $aesMode, $this->key, OPENSSL_RAW_DATA | OPENSSL_NO_PADDING, $ivCounter);
$ivNumber = \gmp_init(bin2hex($ivCounter), 16);
$ivNumber = \gmp_add($ivNumber, $blockCount);
$ivNumber = \gmp_mod($ivNumber, $modulo);
$ivNumber = str_pad(\gmp_strval($ivNumber, 16), $blockSize * 2, "0", STR_PAD_LEFT);
$ivCounter = hex2bin($ivNumber);
if ($this->callback !== null) {
call_user_func($this->callback, $encrypted);
}
if ($outputHandle !== null) {
fwrite($outputHandle, $encrypted);
}
}
}
fclose($inputHandle);
if ($outputHandle) fclose($outputHandle);
return true;
}
public function getCipherMode(): string {
$bitStrength = strlen($this->key) * 8;
return "aes-$bitStrength-ctr";
}
public function getKey(): string {
return $this->key;
}
public function getIV(): string {
return $this->iv;
}
}