blogspace/internal/web/handlers_auth.go, branch master

Security: Refuse form posts a browser marks as coming from another origin

2026-09-18T10:48:50+00:00

Every blog is a subdomain of the root domain, which makes a blog page
"same-site" to the dashboard: SameSite=Lax sends the session cookie
with a form a blog's custom HTML submits to example.com. The HMAC token
already stops those, but the login form had nothing (login CSRF), and
a second, independent check costs one header lookup. A POST whose
Sec-Fetch-Site is cross-site or same-site is now refused in guardPOST
and on login; old browsers without the header keep working under the
token alone.

Co-Authored-By: Claude Opus 5 
Claude-Session: https://claude.ai/code/session_01Sd8UPWrvyYCLj97JexNw3A

Security: Check the CSRF token on logout

2026-09-18T10:48:27+00:00

/logout was the one management POST without the token. A blog lives on
a subdomain of the root domain, which is same-site, so SameSite=Lax
does not keep the cookie off a form a blog page submits: any blogger's
custom HTML could log the superadmin out at will. The logout form
already carried _csrf; the handler now checks it through guardPOST.

Co-Authored-By: Claude Opus 5 
Claude-Session: https://claude.ai/code/session_01Sd8UPWrvyYCLj97JexNw3A

Security: Reject backslashes in post-login redirect targets

2026-09-18T10:48:02+00:00

safeNext only refused a second leading slash, but browsers treat
"/\evil.com" as "//evil.com", so ?next= was still an open redirect
after login. No path of ours contains a backslash, so any one is refused.

Co-Authored-By: Claude Opus 5 
Claude-Session: https://claude.ai/code/session_01Sd8UPWrvyYCLj97JexNw3A

Security: Add HTTPS and TRUST_PROXY settings

2026-09-18T10:47:49+00:00

The app only ever speaks plain HTTP, so it could not know the site was
served over TLS: generated links were http:// (the /webadmin bounce
from a blog host sent the login page over http), the session cookie
was never Secure and nothing sent HSTS. HTTPS=true fixes all three;
ClearSessionCookie now uses the same attributes as the set, since a
browser only replaces a cookie whose Secure flag matches.

TRUST_PROXY=true makes the client address the last X-Forwarded-For
entry — the one our proxy appended — so throttling and the log see
real addresses instead of the proxy's; earlier entries are whatever
the client sent and are ignored. Production startup warns when HTTPS
is off.

Co-Authored-By: Claude Opus 5 
Claude-Session: https://claude.ai/code/session_01Sd8UPWrvyYCLj97JexNw3A

Security: Cap the login body and log failed logins

2026-09-18T10:46:33+00:00

POST /webadmin is the one form outside guardPOST, so nothing bounded
its body: a multipart login could park 32 MB in memory or temp files
per request. It now reads at most 64 KB. Wrong passwords are logged
with the username and client address so an attack shows up in the log
(fail2ban can read it) instead of being invisible.

Co-Authored-By: Claude Opus 5 
Claude-Session: https://claude.ai/code/session_01Sd8UPWrvyYCLj97JexNw3A

Security: Throttle login attempts with a per-address, per-account token bucket

2026-09-18T10:46:11+00:00

Nothing stopped a bot from trying passwords against /webadmin as fast
as bcrypt would go. A small in-memory limiter (stdlib only, one
process) now refuses a login with 429 once an address, or an account,
has made ten attempts, and lets one more through every six seconds;
keying on both means many addresses guessing one account are throttled
too. Refusals are logged.

Co-Authored-By: Claude Opus 5 
Claude-Session: https://claude.ai/code/session_01Sd8UPWrvyYCLj97JexNw3A

Send a blogger to their own dashboard from another blog's /webadmin

2026-09-18T08:24:43+00:00

Typing /webadmin on someone else's blog while logged in (or logging in
from there) landed on /b// and a 403 "This is not your blog."
Both login paths now go through landing(), which swaps a next that points
at a blog the user cannot manage for /dashboard; superadmins keep going
where they asked.

Co-Authored-By: Claude Opus 5 
Claude-Session: https://claude.ai/code/session_01Sd8UPWrvyYCLj97JexNw3A

Add languages: English and Greek, chosen per blog on the Settings tab

2026-09-13T22:32:25+00:00

Every blog and its dashboard were hard-wired to English. A blogger can
now pick the language of their blog; it switches the whole dashboard and
the blog's fixed text — post dates, archive months, the RSS link, the
pager, the 404 page — while what the blogger wrote is left alone.

The new internal/i18n package keys translations by the English string,
so an untranslated key renders as English rather than blank, and
TestGreekCatalogComplete scans the templates and handlers to fail when
the Greek catalog misses a key or keeps a stale one. Templates are
compiled once per language with t/tf/date/postdate/month closed over the
language, so they need no data plumbing.

The language lives in settings.language (blog migration 00002), not in
the theme, so "Reset design" does not touch it. Public pages use the
blog's language; management pages use the logged-in user's own blog's,
so a superadmin editing someone else's blog keeps theirs; the login page
follows Accept-Language.

Co-Authored-By: Claude Opus 5 
Claude-Session: https://claude.ai/code/session_01Sd8UPWrvyYCLj97JexNw3A

Rename /login to /webadmin and reach it from every blog

2026-09-12T09:15:47+00:00

The login URL is less guessable, bloggers can type /webadmin on their own
blog and get bounced to the root login page (and back to their dashboard
after logging in), and the public root blog no longer advertises the
admin entry point in its footer.

Co-Authored-By: Claude Opus 5 
Claude-Session: https://claude.ai/code/session_01Sd8UPWrvyYCLj97JexNw3A

Serve the superadmin's blog on the root domain

2026-09-12T08:43:14+00:00

The base domain (and www.) now serves a regular blog owned by the first
superadmin, created automatically on startup, alongside the management
routes. Literal management paths take precedence over the blog's page
wildcards, and the slugs they would shadow are reserved.

Co-Authored-By: Claude Opus 5 
Claude-Session: https://claude.ai/code/session_01Sd8UPWrvyYCLj97JexNw3A