* Make backend tests wait on conditions instead of durations
The backend workflow has a long tail of runs that fail once and pass on
a rerun. Every one of them comes down to a test assuming an operation
finishes within some duration rather than waiting for the state it
needs. Three were reproducible and each was reproduced against the old
code before being changed: TestServerAuthHooks minted a token that lived
one second and never tested expiry, so a slow runner turned the first
POST into a 401; TestServerApp_AnonMode saw "connection refused" because
waitForHTTPServerStart returned silently after three seconds and left a
later assertion to fail with something unrelated; TestFsStore_Cleanup
slept 200ms against a 300ms ttl that Cleanup widens to 400ms with its
commit grace, so roughly 100ms of stall collected an image meant to
survive.
Fixed sleeps before asserting on asynchronous work are replaced with
polls on the condition itself, using require.Eventually and
require.EventuallyWithT, and require.Never where the assertion is that
something did not happen. Polling closures assert on the CollectT they
are handed rather than on t, since testify runs them on another
goroutine, and polls that issue HTTP requests stay under the rate limit
on the routes they poll through.
Where a test needs time to have passed, the clock input is pinned
instead: staging ages are stamped with os.Chtimes on both sides of the
cleanup boundary right before each call, which also makes the 100ms
commit grace an exact case rather than something no assertion reaches,
and the RSS tests set store.Comment.Timestamp explicitly rather than
racing the wall clock into the first 100ms of a second so pubDate
matches.
chooseUnusedPort takes a port from the kernel's ephemeral range. Picking
at random out of a fixed 10000-port window let two package binaries,
which go test ./... runs concurrently, land on the same number between
the probe closing and the server binding. The start helpers fail naming
the port they waited on, and the SSL tests wait on the redirect port as
well as the TLS one.
Arbitrary budgets that nothing tests are gone: ten HTTP clients with a
one-second timeout against bolt-backed import and export, the "should
take about 100msec" assertions, and a one-second bound on noticing an
already cancelled context. Shutdown stays bounded at ten seconds so a
hang is still caught.
Two assertions get stronger. TestServerAuthHooks accepted 403 or 401
from a blocked user, an alternative that existed only because the short
token could expire mid-test; it is deterministically 403 now.
TestAdmin_BlockedList asserted two users blocked while one carried the
same 150ms ttl the next step waits to lapse, so the halves raced each
other.
goleak stops reporting the regexp2 clock goroutine, which chroma pulls
in for syntax highlighting and which lives for up to a second after the
last match with a timeout; it ends on its own but a binary finishing
inside that window was reported as leaking, and this suite now finishes
sooner. The ignore for net/http.(*Server).Shutdown goes the other way:
it no longer matches anything, with both packages run fifteen times each
under CPU oversubscription to confirm.
Two gaps the change would otherwise have opened are covered directly
rather than left to the side effects that used to cover them. The
one-second token was the only thing exercising the authenticator's
ClaimsUpd hook on refresh, so TestServerApp_ClaimsUpd now calls the hook
itself and checks admin, blocked, email and restricted-name
impersonation, including the two pass-through cases. Lifting the
open-route limit removed the last incidental exercise of the rate
limiter, so TestRateLimiter drives a burst past the allowance and checks
the refusals and that the limit is per client. Both run without a wall
clock, and both were confirmed to fail when the behaviour they cover is
removed.
Production code is untouched. The two sleeps outside test code, the 429
backoff in cmd/cleanup.go and the submit poll in store/image/image.go,
are left alone: no CI failure implicates them.
Test sleeps drop from 67 to 21, all of them either inside a
testing/synctest bubble or a poll interval. The suite runs in about 22
seconds instead of 46, mostly because
TestPublic_FindCommentsCtrl_ConsistentCount no longer paces a hundred
subtests with an 80ms sleep each to stay under the open route limit. The
300s per-package budget now matches across both workflows, the race_test
target and the documented command, and CLAUDE.md records the convention.
with '#' will be ignored, and an empty message aborts the commit. # #
Date: Sat Aug 22 01:12:31 2026 +0100 # # interactive rebase in progress;
onto 7c312da1 # Last command done (1 command done): # reword deb6cbf1 #
Make backend tests wait on conditions instead of durations # Next
command to do (1 remaining command): # reword 262e6dc2 # Apply go fix
under Go 1.27 # You are currently editing a commit while rebasing branch
'fix/backend-test-flakiness' on '7c312da1'. # # Changes to be committed:
.github/workflows/release.yml # modified: CLAUDE.md # modified: Makefile
modified: backend/_example/memory_store/server/rpc_test.go # modified:
backend/app/cmd/import_test.go # modified:
backend/app/cmd/server_test.go # modified: backend/app/main_test.go #
modified: backend/app/rest/api/admin_test.go # modified:
backend/app/rest/api/middleware_test.go # modified:
backend/app/rest/api/migrator_test.go # modified:
backend/app/rest/api/rest_private_test.go # modified:
backend/app/rest/api/rest_public_test.go # modified:
backend/app/rest/api/rest_test.go # modified:
backend/app/rest/api/rss_test.go # modified:
backend/app/rest/proxy/image_test.go # modified:
backend/app/store/image/fs_store_test.go # modified:
backend/app/store/service/service_test.go # modified:
docs/backlog/api-tests-deadlock-on-macos.md #
* Apply go fix under Go 1.27
Go 1.27 extends go fix with the modernizers, so `go fix ./...` now
rewrites patterns the language has since replaced. Running it across all
three modules produces this: legacy sync/atomic calls on plain integers
become the atomic types (notify.Service.closed, image.Service.term and
submitCount, and several test counters), reverse index loops become
slices.Backward, a Split-then-index becomes strings.Cut, counted loops
become range over an int, and interface{} becomes any in the e2e suite.
The example module needed no changes. The e2e module is behind a build
tag, so it only matches with `go fix -tags e2e ./...`.
One knock-on: prealloc can see the bound of a loop once it is written as
range over an int, so the slice it feeds is now preallocated.
with '#' will be ignored, and an empty message aborts the commit. # #
Date: Sat Aug 22 01:32:09 2026 +0100 # # interactive rebase in progress;
onto 7c312da1 # Last commands done (2 commands done): # reword deb6cbf1
262e6dc2 # Apply go fix under Go 1.27 # No commands remaining. # You are
currently editing a commit while rebasing branch
'fix/backend-test-flakiness' on '7c312da1'. # # Changes to be committed:
backend/app/migrator/native.go # modified: backend/app/notify/notify.go
backend/app/rest/api/rest_private_test.go # modified:
backend/app/store/comment.go # modified:
backend/app/store/image/image.go # modified:
backend/app/store/service/service_test.go # modified:
backend/app/store/service/title_test.go # modified: e2e/e2e_test.go #
modified: e2e/widgets_test.go #
* fix(security): reject non-image content-types in image proxy and /picture/ to prevent stored XSS
The /api/v1/img proxy and /api/v1/picture/{user}/{id} endpoints emitted
http.DetectContentType on the served bytes as the response Content-Type. A
controlled upstream serving Content-Type: image/png with an HTML body passed
the upstream check (only the response header was inspected, not the body),
and the body bytes then sniffed back to text/html — so the proxy served the
attacker's HTML from the remark42 origin. Browsers honoured the declared
text/html and executed the response as a document with access to cookies and
CSRF tokens. Affected from v1.6.0 (April 2020) through v1.15.0; verified live
via published docker images.
Layered defense applied to both handlers:
- rest.SafeImgContentType (in backend/app/rest/) validates sniffed content
against a strict allowlist: image/png, image/jpeg, image/gif, image/webp,
image/bmp, image/x-icon. Anything else (HTML, XML, SVG, plain text,
octet-stream, or any future image type the stdlib sniffer may learn) is
rejected with no body echo. SVG is implicitly excluded — it sniffs as
text/xml or text/plain, never image/svg+xml, and SVG can execute scripts
when navigated to top-level. The previous octet-stream → image/* fallback
is gone.
- Per-endpoint Content-Security-Policy override sets
"default-src 'none'; sandbox; frame-ancestors 'none'" on every response
(success, 304, or error). Sandbox neuters scripts even if Content-Type
ever regresses. The same policy is also applied to all /api/v1/* via
apiCSPMiddleware as defense-in-depth.
- Content-Disposition: inline; filename="image" frames the response as a
file rather than a renderable document.
- /picture/ rejection paths set Cache-Control: no-store so 4xx responses
are never cached.
The defense headers and the strict ETag matcher are extracted as
rest.SetImageDefenseHeaders and rest.EtagMatches in the shared rest package
(consumed by both proxy/image and api/rest_public — no package cycle).
The /api/v1/img path additionally bumps the ETag to a versioned `"v2:..."`
so revalidating clients (top-level navigation, Ctrl+R, intermediaries) get
a fresh 200 instead of a 304 against poisoned pre-fix cached HTML.
DELIBERATE TRADEOFF: Cache-Control on /api/v1/img success responses remains
max-age=2592000 (30 days), unchanged from before. An aggressive "force
revalidate on every reuse" policy was prototyped during review but reverted
because the perf cost (a server round-trip on every image view, even with
304 saving the body bytes) outweighed the corner-case mitigation. The
realistic exposure of cache carryover is narrow: cache carryover only
affects users who navigated top-level to an attacker URL pre-fix and still
have it in their local cache — the normal <img> embed path cached text/html
but never executed it. Local browser caches that hold pre-fix bytes
continue to serve them until their 30-day TTL expires or are evicted under
memory pressure. The ETag bump reaches all clients that DO revalidate
during the cached lifetime (Ctrl+R, intermediaries, post-expiry use); for
the rest, exposure self-limits via cache expiry. Operators running a
CDN/edge cache in front of remark42 should purge /api/v1/img after deploy.
The /api/v1/img handler short-circuits on a matching current-version
If-None-Match before any store Load or upstream fetch, returning a bodyless
304 with the defense headers set. Safe because the 304 carries no body and
the client's cached bytes came from a prior validated 200; an attacker
fabricating an etag value can only short-circuit fetches for URLs they
themselves crafted. This avoids upstream DoS amplification when clients
revalidate on hot comment pages.
The /api/v1/img route was moved from the "open routes" group (which uses
middleware.NoCache, stripping If-None-Match from incoming requests) to the
"open routes, cached" group alongside /picture/ and /qr/telegram so the
304 revalidation path is no longer broken upstream of the handler.
The /picture/{user}/{id} endpoint does not need the v2 etag prefix. Upload
validates input format via readAndValidateImage and the serve path
re-validates the stored bytes via rest.SafeImgContentType. Bytes within
the resize dimension limits are preserved verbatim, so the browser defense
relies on the response headers (validated Content-Type + nosniff + strict
CSP + Content-Disposition: inline), not on byte normalization.
Global CSP: font-src data: → font-src 'none'. Audit confirmed no @font-face,
no base64 fonts, no icon-font library in the bundle. Drops an unnecessary
attack surface; no behavioural change.
Tests: TestImage_ContentTypeHandling table-tests a real PNG and attack
shapes (HTML claimed as image/png, image/jpeg, image/gif, image/svg+xml,
image/webp; svg with onload; html fragment; polyglot PNG+HTML), proving
the defense holds across arbitrary upstream Content-Type variation.
Polyglot case is intentionally served as image/png — the browser cannot
execute the trailing HTML when the response type is image/png with nosniff.
TestImage_ContentTypeHandling_CacheHit exercises the cache-hit branch with
attacker bytes preloaded into the store. TestImage_PerRequestRevalidation
alternates upstream PNG/HTML across four proxy calls to prove no trust
accumulates between requests. TestImage_RoutesUsingCachedImage asserts
cache-poisoning is caught at serve time. TestImage_EtagVersioned asserts
the v2 prefix invalidates pre-fix etags AND that the revalidation 304
triggers no store Load. TestImage_RevalidationSkipsIO proves the
short-circuit works even with no upstream reachable. TestSafeImgContentType
covers the allowlist directly. TestRest_LoadPictureDefenseHeaders and
TestRest_LoadPictureRejectsNonImage exercise the /picture/ endpoint.
TestRest_apiCSP covers the strict CSP middleware on JSON API + RSS routes;
TestRest_securityHeaders confirms /web/ HTML pages keep the global CSP.
Verified end-to-end against the dev docker image: the original demo URL
(arbitrary HTML claimed as image/png) now returns 415 application/json with
CSP/nosniff/Content-Disposition set, no XSS in the browser.
* fix(security): set Cache-Control: no-store on image-proxy error paths, sync stale route comment
Addresses two review comments on #2067:
1. Cache-Control: max-age=2592000 and Etag were set before the
load/download/validation block, so 404/400/415 error responses inherited
the 30-day cache TTL and the versioned etag — a transient failure (or an
intentionally triggered 415) would be pinned in browser/intermediary
caches for that TTL, keeping users locked out even after the underlying
cause was resolved. Now: etag is computed but not set as a header until
after validation succeeds; error paths route through sendImageProxyError
which sets Cache-Control: no-store and never sets Etag. The 304
short-circuit still sets both because that path serves the same validated
content the client already has cached.
2. The comment at rest.go:282 still described the prototyped
no-cache/must-revalidate Cache-Control policy that was reverted before
the PR landed. Updated to match the actual 30-day max-age behavior.
Tests: TestImage_ContentTypeHandling now asserts reject paths carry
Cache-Control: no-store and have no Etag header, and accept paths carry
the max-age=2592000 + v2: etag.
Address review feedback on PR #2044.
safehttp.Transport():
* Clone http.DefaultTransport instead of building a bare &http.Transport{} so
Proxy, ForceAttemptHTTP2, MaxIdleConns, IdleConnTimeout, TLSHandshakeTimeout
and ExpectContinueTimeout are inherited (the bare struct loses them all).
Verified by new TestTransport_PreservesDefaultTransportSettings.
* TestTransport_AllowsPublic: bound the dial of TEST-NET-3 with a 100ms
context so the test does not depend on real-world routing of 203.0.113.0/24,
and drop the dead dialer var.
proxy/image.go:
* Document Image.Transport contract: nil installs safehttp.Transport (SSRF-safe);
caller-supplied transport is the caller's responsibility.
* Replace the misleading "SSRF mitigated by safehttp.Transport" nolint comments
with one that points at the documented contract above.
The image proxy got an ssrfSafeTransport in commit aca0cff3 that resolves
DNS first, blocks any IP in private/reserved CIDRs, then dials by IP to
defeat DNS rebinding. The TitleExtractor used to construct comments'
PostTitle from Locator.URL — a user-supplied field — was missed by that
fix and kept using http.DefaultTransport. The hostname allowlist there
checks the parsed URL host but never the IP it resolves to, so a domain
suffix-matching an allowed host (or 127.0.0.1 itself when AllowedHosts
is empty) reaches the metadata service or any other internal endpoint.
The same gosec rule (G704) was excluded globally in .golangci.yml as part
of aca0cff3, so this gap was not caught by the linter either.
Extract the transport into a new safehttp package so it lives in one
place and can be reused, then pass safehttp.Transport() into the
TitleExtractor's http.Client at construction (cmd/server.go). The image
proxy switches to safehttp.Transport() too — same behaviour, no longer
duplicated.
Reproduction in title_test.go uses the production-style client to hit
an httptest.Server (always 127.0.0.1) and asserts the dialer refuses
even though "127.0.0.1" is in the allowed-domains list. A control case
shows the same setup without safehttp.Transport returns the page —
making the original vulnerability explicit.
Apply go fix ./... analysers (Go 1.26) across backend and examples:
- interface{} → any (type alias, no behaviour change)
- for i := 0; i < N; i++ → for range N / for i := range N
- slices.Contains / slices.ContainsFunc replacing manual loops
- strings.SplitSeq replacing strings.Split in range (avoids allocation)
- strings.CutPrefix replacing HasPrefix+TrimPrefix
- min() replacing manual if/else
- fmt.Appendf replacing []byte(fmt.Sprintf(...))
- strings.Builder replacing string += concatenation
- wg.Go(func(){}) replacing wg.Add(1)/go/wg.Done() pattern
- removed redundant ii := i loop variable copies (unnecessary since Go 1.22)
omitempty on struct-typed JSON fields: go fix removed omitempty from
struct-typed fields (time.Time, PostInfo, UserDetailEntry) because
encoding/json's omitempty never applied to struct types — it was always
a no-op. Kept as bare tags (no omitzero replacement) to preserve the
existing serialisation behaviour.
Replace strings.Split(RemoteAddr, ":") with net.SplitHostPort for correct
IPv6 address extraction in vote deduplication and comment IP tracking.
Harden image proxy: add SSRF-safe transport blocking private/reserved IPs
at connection time with DNS rebinding protection, sanitize error messages
to prevent information leakage, add response size limit via io.LimitReader.
Fix shadowed error variables in BlockedUsers, SetTitle, and Delete methods.
Exclude gosec taint analysis false positives at linter config level.
@paskal
* sort imports, add missing copyright
* regenerate engine mock
* make all image.Store interface functions public
* go mod tidy
* make image.Store.Load return []byte instead of io.ReadCloser
* separate memory_store example RPC server to multiple files by handlers groups
* fix potential race on close
* move validate inside
* demote commit and cleanup in image.Store to non-exposed functions.
* replace immediate image commit with delayed via Submit
* minor: remove error logging, rename tests
* minor: err wrapping, comments wording
* clarify FileSystem.Save code
* attempt to fix#584 by making submitted image commits on a half of TTL
Co-authored-by: Dmitry Verkhoturov <paskal.07@gmail.com>
* fresh vendor
* enforce vendor flag with env
* move tree to service package
* move controllers routing to rest.go, remove separate subrouters
* cleanup/formatting
* missing vendor packages
* move rss, img proxy, robots and getstarted to top-level routes
* simplify logger middleware usage
* randomize server test ports
* check for non-admin in admin tests
* lint: minor warns
* admin test to jwt admin
* support flags commands, move to cmd
* fix target name
* test for happy path importer
* add export cmd
* fix wrong import, lint warns
* increase test timeout
* add sellp to allow main test server to start
* implement all cmds
* handle backup/restore errors
* fix import status check, hide secret from logs
* backup cmd err tests
* randimize test port
* avoid dup code in Last controller
* add target to make all bin archives
* remove container in make
* add smiple scripts to simplify commands, update readme
* add docs on dockerless, enforce app user
* add restore info
* move last to lastCommentsScope const
* WIP: start mongo engine
* WIP: mongo accessor and admin
* integrate mongo store to main
* disable mongo tests by default, only in CI
* connection with constructor
* add mongo buffered writer
* buffered mongo writer
* fix nil responses on an empty list from mongo
* missing mongo index for scores
* cancelable store
* add gridfs implementation of avatar store
* fix race on mongo session copy
* gridfs avatars without tmp files
* move avatar store
* minor comments and refactoring for avatar store
* merged from current master
* simplify gridfs reader
* lint: fix minor warns
* test mongo against env defined url
* pass MONGO_REMARK_TEST to docker and travis
* set dockerfile env for mongo test url
* increase connect timeout in mongo tests
* pass MONGO_REMARK_TEST to drone build
* add MONGO_REMARK_TEST to branch stage of drone
* mass mongo test url via build_args_from_env
* populate mongo IP to docker build hosts
* test env
* pass mongo ip via .mongo
* remove .mongo temp from git
* add .mongo -> env to linter step
* allow more time to autoflush writer test
* default mongo tests to "mongo" if not in env
* merge fresh master into
* add test for mongo cleanup
* msg for a failed test
* lazy fix for failed test
* add an ability to skip all mongo tests
* add backend dev instructions
* remove unused code from mongo server
* move mongo testing to connection_test
* restore testing.go
* lint: minor warns for testing code
Dmitry VerkhoturovandGitHub
Anton PanferovandUmputun