Security hardening from the assessment; testing fixes

Security (ultimo-security-report.md):
- Security headers on every response, the app shell included: they lived at
  server level and nginx dropped them in any location with its own header.
  CSP, framing, nosniff, referrer, permissions (docker/nginx-security.conf).
- Plain HTTP forwarded by the reverse proxy is redirected to HTTPS; HSTS on
  HTTPS responses. server_tokens off.
- Cross-site state-changing /api requests refused (login CSRF), WebSocket too.
- Validation errors in the usual error shape, without the request model.
- New-password policy: max 128, common/own-address/repeated refused,
  breached-password check (HIBP k-anonymity, fails open).
- Message HTML: links keep only http(s)/mailto (sanitizer v6); the HTML
  endpoint carries its own no-script CSP.
- Outbound fetches pinned to the checked IP (DNS rebinding); external
  IMAP/SMTP servers re-checked before each connection; CGNAT and mapped
  addresses counted as non-public.

Fixes from testing:
- IDLE loop catches up before idling: mail that came while the worker was
  away no longer waits up to 10 minutes.
- Restore from Spam/Trash/Archive moves only the removed messages, not your
  reply in Sent.
- Narrow desktop list stacks sender/subject/snippet (subject was squeezed
  to nothing at the default width), with hover actions.
- Phone: wide emails scale to fit the screen.
- Singular forms ("1 message"); no zip button for a single attachment;
  app passwords no longer claim "never used" for mail apps.
- ruff format across the backend.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

This commit is contained in:

lukas

2026-10-14 22:08:06 +02:00

co-authored by

Claude Opus 5.5

parent 30b806e7da

commit addb2232a1

54 changed files with 1265 additions and 187 deletions

									
										docker-compose.yml
									
		+2
		
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				@@ -77,6 +77,8 @@ x-backend-env: &backend-env

				  MAX_ATTACHMENT_MB: ${MAX_ATTACHMENT_MB:-25}

				  TRASH_RETENTION_DAYS: ${TRASH_RETENTION_DAYS:-30}

				  SENDER_AVATARS_ENABLED: ${SENDER_AVATARS_ENABLED:-true}

				  # New passwords checked against Have I Been Pwned (k-anonymity; docs §5.2).

				  PASSWORD_BREACH_CHECK: ${PASSWORD_BREACH_CHECK:-true}

				  GOOGLE_OAUTH_ENABLED: ${GOOGLE_OAUTH_ENABLED:-false}

				  OAUTH_GOOGLE_CLIENT_ID: ${OAUTH_GOOGLE_CLIENT_ID:-}

				  OAUTH_GOOGLE_CLIENT_SECRET: ${OAUTH_GOOGLE_CLIENT_SECRET:-}