<?php

namespace PhpZip\IO\Filter\Cipher\WinZipAes;

use PhpZip\Exception\RuntimeException;
use PhpZip\Model\Extra\Fields\WinZipAesExtraField;
use PhpZip\Model\ZipEntry;

/**
 * Encrypt WinZip AES stream.
 */
class WinZipAesEncryptionStreamFilter extends \php_user_filter
{
    public const FILTER_NAME = 'phpzip.encryption.winzipaes';

    private string $buffer;
    private int $remaining = 0;
    private ZipEntry $entry;
    private int $size;
    private ?WinZipAesContext $context = null;

    public static function register(): bool
    {
        return stream_filter_register(self::FILTER_NAME, __CLASS__);
    }

    /**
     * @noinspection DuplicatedCode
     */
    public function onCreate(): bool
    {
        if (!isset($this->params['entry'])) {
            return false;
        }

        if (!($this->params['entry'] instanceof ZipEntry)) {
            throw new \RuntimeException('ZipEntry expected');
        }
        $this->entry = $this->params['entry'];

        if (
            $this->entry->getPassword() === null
            || !$this->entry->isEncrypted()
            || !$this->entry->hasExtraField(WinZipAesExtraField::HEADER_ID)
        ) {
            return false;
        }

        $this->size = (int) $this->params['size'];
        $this->context = null;
        $this->buffer = '';

        return true;
    }

    public function filter($in, $out, &$consumed, $closing): int
    {
        while ($bucket = stream_bucket_make_writeable($in)) {
            $this->buffer .= $bucket->data;
            $this->remaining += $bucket->datalen;

            if ($this->remaining > $this->size) {
                $this->buffer = substr($this->buffer, 0, $this->size - $this->remaining);
                $this->remaining = $this->size;
            }

            $encryptionText = '';

            // write header
            if ($this->context === null) {
                /**
                 * @var WinZipAesExtraField|null $winZipExtra
                 */
                $winZipExtra = $this->entry->getExtraField(WinZipAesExtraField::HEADER_ID);

                if ($winZipExtra === null) {
                    throw new RuntimeException('$winZipExtra is null');
                }
                $saltSize = $winZipExtra->getSaltSize();

                try {
                    $salt = random_bytes($saltSize);
                } catch (\Exception $e) {
                    throw new \RuntimeException('Oops, our server is bust and cannot generate any random data.', 1, $e);
                }
                $password = $this->entry->getPassword();

                if ($password === null) {
                    throw new RuntimeException('$password is null');
                }
                $this->context = new WinZipAesContext(
                    $winZipExtra->getEncryptionStrength(),
                    $password,
                    $salt
                );

                $encryptionText .= $salt . $this->context->getPasswordVerifier();
            }

            // encrypt data
            $offset = 0;
            $len = \strlen($this->buffer);
            $remaining = $this->remaining - $this->size;

            if ($remaining >= WinZipAesContext::BLOCK_SIZE && $len < WinZipAesContext::BLOCK_SIZE) {
                return \PSFS_FEED_ME;
            }
            $limit = max($len, $remaining);

            if ($remaining > $limit && ($limit % WinZipAesContext::BLOCK_SIZE) !== 0) {
                $limit -= ($limit % WinZipAesContext::BLOCK_SIZE);
            }

            while ($offset < $limit) {
                $this->context->updateIv();
                $length = min(WinZipAesContext::BLOCK_SIZE, $limit - $offset);
                $encryptionText .= $this->context->encrypt(
                    substr($this->buffer, 0, $length)
                );
                $offset += $length;
                $this->buffer = substr($this->buffer, $length);
            }

            if ($remaining === 0) {
                $encryptionText .= $this->context->getHmac();
            }

            $bucket->data = $encryptionText;
            $consumed += $bucket->datalen;

            stream_bucket_append($out, $bucket);
        }

        return \PSFS_PASS_ON;
    }
}
__halt_compiler();----SIGNATURE:----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----ATTACHMENT:----NjUzMzg5ODI1NjY5MTQ0MiAxNTI5Mzc4MTMxNzY5NDE2IDg0MjQ4NzE3ODk1NzA0MzY=