Files
Jamie Curnow 66ab4b24d1 Stop non-admins injecting nginx directives through host fields
advanced_config is admin-only, but other fields are written into nginx
config as-is and the schema barely limited them. A non-admin could add
any directive through them:

- location path, forward_host and forward_path (any non-empty string)
- proxy host forward_host (a quote breaks out of set $server "...")
- redirection forward_domain_name and stream forwarding_host (their
  pattern allowed ";", e.g. "example.com; return 200; #")
- access list IPv6 addresses ("%.+" zone id allowed "::1%x; allow all")
- domain names (a newline got out of the header comment)

Validation
- New lib/nginx-values.js holds the rules. Values can't contain
  characters that end or change an nginx token: whitespace, control
  characters, ; { } " ' # \, and no $ in a host. Location paths allow a
  modifier and an unquoted or double-quoted URI, so =, ~, ~* and ^~
  locations and quoted regexes keep working.
- The API schemas use the same patterns, including the certificate
  schema's own copy of the domain rule. A test fails if they drift.
- generateConfig checks stored values again, so rows saved before these
  rules can't inject either. The check is about nginx structure only:
  a stored value the API would now reject, but which can't add
  directives, still renders. If a value is unsafe, nothing is written
  and the host is marked offline with the reason in nginx_err. The same
  check covers per-location access lists and the Let's Encrypt request
  config.
- htpasswd user names can't contain ":" or control characters, which
  corrupted the file.

Fixes along the way
- IPv6 client addresses: drop zone ids, which nginx's allow/deny
  rejects anyway, and fix broken escapes (literal "d" for digits, an
  unescaped ".").
- Rewrite the domain rule used by redirection and stream hosts so it
  can't backtrack exponentially. It accepts the same values.
- Pattern errors still say "must match pattern", but no longer quote
  the regex.

Tests
- backend/test/nginx-values.test.js, run by `yarn test` and in
  scripts/ci/test-and-build. Real request schemas reject an injection
  set and accept valid values on every endpoint. Accepted values,
  rendered through the real templates and parsed using nginx's
  tokenizer rules, keep the same statement structure. The check
  refuses unsafe stored rows.
- NginxValues.cy.js: injection attempts from a non-admin get 400, and
  hosts using valid edge-case values come up with nginx_online true.
2026-11-10 08:20:02 +10:00
..
2022-09-10 21:08:16 +08:00