Caddy v2.11.9：修复破坏性回归与多项FastCGI安全漏洞

This is a quick follow-up on top of 2.11.8, to fix a regression it introduced and a few more security issues, mostly in FastCGI. It contains only fixes backported from master, plus a couple of small additions. If you're on 2.11.8 and serve PHP, we recommend upgrading.

Huge thank you to our sponsors for keeping the project alive with resources, and for our maintainers who triage and assist tirelessly in this relentless new age of AI.

Highlights

• Fixed: PHP directory indexes (regression in 2.11.8). A request for a directory with a trailing slash, like /wp-admin/, was matched by the directory itself instead of its index.php, so it never reached PHP and usually got a 404. This broke WordPress admin pages and other apps that serve an index through a trailing-slash URL. A try_files pattern now only matches a directory when it ends in /. Thanks @dunglas! (#8352)
• Path matchers with placeholders now work as expected: placeholders like {env.FOO} are no longer lower-cased into {env.foo} before they're looked up, and their values are compared case-insensitively against the request path, like static patterns. Thanks @BenMacha! (#8343)
• New plain_time_format option for file_server browse: sets the time layout of plain-text directory listings (Accept: text/plain). Thanks @steffenbusch! (#8084)
• Fewer allocations in path cleaning, header rewriting and weighted_round_robin selection. Thanks @jvoisin! (#7842)
• For plugin authors: new httpcaddyfile.Helper.IsNamedRoute() tells a directive whether it's being parsed inside a named route. (#8354)

⚠️ Breaking changes

• Conflicting client_auth is now a Caddyfile error. When two site blocks share TLS connection policies for the same hostname but set different client_auth, the adapter used to keep the first one and silently drop the other, which could quietly remove a stricter mTLS requirement. (#8306)
• FastCGI requests that are ambiguous about which script they run get 400:
• when the escaped path (which %-containing path matchers see) and the decoded path would select different scripts, e.g. /public/tool.php%2f..%2f..%2fadmin%2ftool.php (#8357)
• on Windows, script paths with an 8.3 short name component (like ADMINI~1) or a : (NTFS alternate data streams) (#8356)
• FastCGI env values now take precedence over request headers, so a client can no longer override HTTP_* variables you set with env (see below). (#8358)

Security fixes

Thank you to everyone who reported responsibly and helped with patches:

• fastcgi: A client could override any HTTP_* variable set with the FastCGI transport's (or php_fastcgi's) env subdirective by sending a matching request header, for example choosing the user an application sees in HTTP_X_AUTH_USER. Configured values now win. Reported by @JebeenLee and @Camel4, fixed by @dunglas. (GHSA-q34h-28rj-5hjm, #8358)
• fastcgi: On Windows, NTFS 8.3 short names and alternate data streams could run a script that a path rule was meant to deny, completing the FastCGI fix from 2.11.8. Thanks @dunglas. (GHSA-9cr8-wmhh-39pm, #8356)
• fastcgi: Encoded slashes and dot segments could make a %-containing path matcher approve one script while another one runs. Thanks @dunglas. (#8357)
• fastcgi: Over HTTP/2, a host field sent next to :authority could make the application see a different host (HTTP_HOST) than the one Caddy routed the request to. Thanks @dunglas. (#8355)
• httpcaddyfile: A stricter client_auth could be silently dropped when merging TLS connection policies (see above). Thanks @sam-kota. (#8306)
• Updated go-jose to v4.1.6 for GHSA-mgcc-cww5-fp2q. (#8299)

⚠️ These security patches may be breaking if your application relies on the buggy behaviors.

🚨 Notice for Caddy plugin maintainers: Dependabot will probably alert you to the security fixes in Caddy and urge you to upgrade it in your go.mod file. Please ONLY upgrade the Caddy dependency if there's a change to an exported API your plugin uses.

What's Changed

• caddyhttp: lower-case path patterns with placeholders at request time by @BenMacha in #8343
• httpcaddyfile: reject conflicting client_auth when merging TLS policies by @sam-kota in #8306
• build(deps): bump the actions-deps group across 1 directory with 10 updates by @dependabot[bot] in #8340
• build(deps): bump github.com/go-jose/go-jose/v4 from 4.1.5 to 4.1.6 by @dependabot[bot] in #8299
• fileserver: make plain-text browse time format configurable by @steffenbusch in #8084
• fileserver: only match a dir when the pattern ends by / by @dunglas in #8352
• httpcaddyfile: add Helper.IsNamedRoute by @dunglas in #8354
• fastcgi: take HTTP_HOST from the routed host only by @dunglas in #8355
• fastcgi: reject Win 8.3 aliases and alt data streams paths by @dunglas in #8356
• caddyhttp: presize buffers in hot paths to reduce allocations by @jvoisin in #7842
• fastcgi: let configured env variables override request headers by @dunglas in #8358
• fastcgi: reject paths whose escaped form selects another script by @dunglas in #8357

Full Changelog: v2.11.8...v2.11.9