fix(presets): harden preset URL installs against unsafe redirects (#2911)

* Harden preset URL installs against unsafe redirects

Preset URL installs already rejected non-HTTPS source URLs, but the authenticated opener follows redirects. Validate the final response URL before writing the ZIP, preserve GitHub release asset URL resolution after the preset command module split, stream the response to disk, and keep catalog config serialization on safe YAML output.

Constraint: open_url follows redirects, so source URL validation alone does not constrain the downloaded target

Rejected: Keep response.read() for simplicity | large preset downloads should not be buffered entirely in memory

Confidence: high

Scope-risk: narrow

Directive: Keep preset URL policy aligned with workflow installer redirect validation

Tested: uvx ruff check src/specify_cli/__init__.py src/specify_cli/presets/__init__.py src/specify_cli/presets/_commands.py tests/test_presets.py

Tested: uv run pytest tests/test_presets.py -q

Not-tested: Real network redirect integration against a live HTTP server

Co-authored-by: OmX <omx@oh-my-codex.dev>

* Reject malformed preset download URLs

Preset downloads should fail early when a URL lacks a hostname, even if the scheme is HTTPS. The redirect error now describes any disallowed target instead of implying that only non-HTTPS redirects are blocked.

* Prevent credentialed preset redirects from downgrading transport

Preset URL downloads already checked the final URL after urllib followed redirects, but that was too late for authenticated requests because same-host redirects could preserve Authorization during the redirect itself. The authenticated HTTP helper now supports an opt-in redirect validator, and preset downloads use it to reject disallowed redirect targets before following them. The redirect auth handlers also stop preserving credentials across HTTPS to non-HTTPS downgrades as defense in depth.

* test(presets): 修复 URL 解析测试 mock 缺少 redirect_validator 参数

重定向安全加固为 open_url 新增 redirect_validator 参数，
两处 fake_open_url mock 签名未同步导致 TypeError。
补齐参数后全部 3717 个测试通过。

---------

Co-authored-by: OmX <omx@oh-my-codex.dev>

src/specify_cli/authentication/http.py

@@ -14,6 +14,7 @@ from __future__ import annotations
 import urllib.error
 import urllib.request
 from fnmatch import fnmatch
+from typing import Callable
 from urllib.parse import urlparse
 
 from . import get_provider
@@ -56,22 +57,36 @@ def _hostname_in_hosts(hostname: str, hosts: tuple[str, ...]) -> bool:
     return any(p == hostname or fnmatch(hostname, p) for p in hosts)
 
 
-class _StripAuthOnRedirect(urllib.request.HTTPRedirectHandler):
-    """Drop ``Authorization`` when a redirect leaves the entry's declared hosts."""
+RedirectValidator = Callable[[str, str], None]
 
-    def __init__(self, hosts: tuple[str, ...]) -> None:
+
+class _StripAuthOnRedirect(urllib.request.HTTPRedirectHandler):
+    """Drop ``Authorization`` when a redirect leaves trusted hosts or downgrades."""
+
+    def __init__(
+        self,
+        hosts: tuple[str, ...],
+        redirect_validator: RedirectValidator | None = None,
+    ) -> None:
         super().__init__()
         self._hosts = hosts
+        self._redirect_validator = redirect_validator
 
     def redirect_request(self, req, fp, code, msg, headers, newurl):
+        if self._redirect_validator is not None:
+            self._redirect_validator(req.full_url, newurl)
+
         original_auth = (
             req.get_header("Authorization")
             or req.unredirected_hdrs.get("Authorization")
         )
         new_req = super().redirect_request(req, fp, code, msg, headers, newurl)
         if new_req is not None:
-            hostname = (urlparse(newurl).hostname or "").lower()
-            if _hostname_in_hosts(hostname, self._hosts):
+            old_scheme = urlparse(req.full_url).scheme
+            new_parsed = urlparse(newurl)
+            hostname = (new_parsed.hostname or "").lower()
+            is_https_downgrade = old_scheme == "https" and new_parsed.scheme != "https"
+            if _hostname_in_hosts(hostname, self._hosts) and not is_https_downgrade:
                 if original_auth:
                     new_req.add_unredirected_header("Authorization", original_auth)
             else:
@@ -103,7 +118,12 @@ def build_request(url: str, extra_headers: dict[str, str] | None = None) -> urll
     return urllib.request.Request(url, headers=headers)
 
 
-def open_url(url: str, timeout: int = 10, extra_headers: dict[str, str] | None = None):
+def open_url(
+    url: str,
+    timeout: int = 10,
+    extra_headers: dict[str, str] | None = None,
+    redirect_validator: RedirectValidator | None = None,
+):
     """Open *url* with config-driven auth, redirect stripping, and fallthrough.
 
     1. Find ``auth.json`` entries whose hosts match the URL.
@@ -113,6 +133,8 @@ def open_url(url: str, timeout: int = 10, extra_headers: dict[str, str] | None =
     5. Non-auth errors (404, 500, network) raise immediately.
 
     *extra_headers* (e.g. ``Accept``) are merged into every attempt.
+    *redirect_validator*, when provided, is called with ``(old_url, new_url)``
+    before following each redirect and may raise to reject the redirect.
     """
     entries = find_entries_for_url(url, _load_config())
 
@@ -135,7 +157,7 @@ def open_url(url: str, timeout: int = 10, extra_headers: dict[str, str] | None =
             continue
 
         req = _make_req(provider.auth_headers(token, entry.auth))
-        opener = urllib.request.build_opener(_StripAuthOnRedirect(entry.hosts))
+        opener = urllib.request.build_opener(_StripAuthOnRedirect(entry.hosts, redirect_validator))
         try:
             return opener.open(req, timeout=timeout)
         except urllib.error.HTTPError as exc:
@@ -146,4 +168,7 @@ def open_url(url: str, timeout: int = 10, extra_headers: dict[str, str] | None =
 
     # No entry worked (or none matched) — unauthenticated fallback
     req = _make_req({})
+    if redirect_validator is not None:
+        opener = urllib.request.build_opener(_StripAuthOnRedirect((), redirect_validator))
+        return opener.open(req, timeout=timeout)
     return urllib.request.urlopen(req, timeout=timeout)  # noqa: S310