# Source code for scrapy.downloadermiddlewares.httpauth

    """
    HTTP basic auth downloader middleware

    See documentation in docs/topics/downloader-middleware.rst
    """

    from __future__ import annotations

    from typing import TYPE_CHECKING

    from w3lib.http import basic_auth_header

    from scrapy import Request, Spider, signals
    from scrapy.utils.decorators import _warn_spider_arg
    from scrapy.utils.url import url_is_from_any_domain

    if TYPE_CHECKING:
        # typing.Self requires Python 3.11
        from typing_extensions import Self

        from scrapy.crawler import Crawler
        from scrapy.http import Response

    class HttpAuthMiddleware:
        """Set Basic HTTP Authorization header
        (http_user and http_pass spider class attributes)"""

        @classmethod
        def from_crawler(cls, crawler: Crawler) -> Self:
            o = cls()
            crawler.signals.connect(o.spider_opened, signal=signals.spider_opened)
            return o

        def spider_opened(self, spider: Spider) -> None:
            usr = getattr(spider, "http_user", "")
            pwd = getattr(spider, "http_pass", "")
            if usr or pwd:
                self.auth = basic_auth_header(usr, pwd)
                self.domain = spider.http_auth_domain  # type: ignore[attr-defined]

        @_warn_spider_arg
        def process_request(
            self, request: Request, spider: Spider | None = None
        ) -> Request | Response | None:
            auth = getattr(self, "auth", None)
            if (
                auth
                and b"Authorization" not in request.headers
                and (not self.domain or url_is_from_any_domain(request.url, [self.domain]))
            ):
                request.headers[b"Authorization"] = auth
            return None