public function readBytes(int $num, bool $skipTests = false) : string
{
if ($num < 0) {
throw new CryptoException\CannotPerformOperation('num < 0');
} elseif ($num === 0) {
return '';
}
if ($this->pos + $num > $this->stat['size']) {
throw new CryptoException\CannotPerformOperation('Out-of-bounds read');
}
$buf = '';
$remaining = $num;
if (!$skipTests) {
$this->toctouTest();
}
do {
if ($remaining <= 0) {
break;
}
$read = \fread($this->fp, $remaining);
if ($read === false) {
throw new CryptoException\FileAccessDenied('Could not read from the file');
}
$buf .= $read;
$readSize = CryptoUtil::safeStrlen($read);
$this->pos += $readSize;
$remaining -= $readSize;
} while ($remaining > 0);
return $buf;
} public function testFileRead()
{
$filename = \tempnam('/tmp', 'x');
$buf = \Sodium\randombytes_buf(65537);
\file_put_contents($filename, $buf);
$fStream = new ReadOnlyFile($filename);
$this->assertSame($fStream->readBytes(65537), $buf);
$fStream->reset(0);
\file_put_contents($filename, Util::safeSubstr($buf, 0, 32768) . 'x' . Util::safeSubstr($buf, 32768));
try {
$fStream->readBytes(65537);
throw new \Exception('fail');
} catch (CryptoException\FileModified $ex) {
$this->assertTrue($ex instanceof CryptoException\FileModified);
}
}
