Bound username length at creation (closes #184 )

A login stores the username in the session cookie, which cannot carry a value past about 4096 bytes, so a username of about 2 KB or more could never log in and the login answered 500. Usernames are now limited to 1024 bytes, about half of what the cookie can carry. The User model rejects a longer one with ErrUsernameTooLong, and a check constraint on the users table rejects it for any path that bypasses the model. The comment on MaxUsernameBytes gives the arithmetic. Model: opus-5-5
2026-09-29 08:35:29 +00:00
9 changed files with 252 additions and 151 deletions
@@ -88,9 +88,7 @@ RUN CGO_ENABLED=1 make build VERSION="$VERSION" GO_LDFLAGS='-extldflags "-static
 # alpine:3.21, 2026-03-17
 FROM alpine:3.21@sha256:c3f8e73fdb79deaebaa2037150150191b9dcbfba68b4a46d70103204c53f4709

-# su-exec 0.2-r3 (Alpine 3.21), 2026-09-29: the entrypoint runs the app
-# as webhooker with it.
-RUN apk --no-cache add ca-certificates su-exec=0.2-r3
+RUN apk --no-cache add ca-certificates

 # Create non-root user
 RUN addgroup -g 1000 -S webhooker && \
@@ -101,17 +99,13 @@ WORKDIR /app
 # Copy binary from builder
 COPY --from=builder /build/bin/webhooker /app/webhooker

-# Not under /app, which belongs to webhooker: this script runs as root.
-COPY deploy/docker-entrypoint.sh /usr/local/bin/docker-entrypoint.sh
-
 # Create data directory for all SQLite databases (main app DB +
 # per-webhook event DBs). DATA_DIR defaults to /var/lib/webhooker.
 RUN mkdir -p /var/lib/webhooker

 RUN chown -R webhooker:webhooker /app /var/lib/webhooker

-# No USER: the entrypoint starts as root to make the data directory
-# webhooker's, then runs the app as webhooker.
+USER webhooker

 EXPOSE 8080

@@ -130,5 +124,4 @@ ENV BIND_ADDRESS=0.0.0.0
 HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
    CMD wget --no-verbose --tries=1 --spider http://localhost:8080/.well-known/healthcheck || exit 1

-ENTRYPOINT ["/usr/local/bin/docker-entrypoint.sh"]
 CMD ["/app/webhooker"]
@@ -552,9 +552,8 @@ printf '%s' "$NEW_PASSWORD" | \
    DATA_DIR=/var/lib/webhooker webhooker resetpw admin
 ```

-In a container it is the same binary. The image's `CMD` is
-`/app/webhooker`, and a command given to `docker run` replaces all of
-it, so the whole command has to be given:
+In a container it is the same binary, which the image sets as `CMD`
+rather than `ENTRYPOINT`, so the whole command has to be given:

 ```bash
 docker run --rm -v webhooker-data:/var/lib/webhooker \
@@ -691,22 +690,38 @@ those three values rather than trusting the figure. Measured at 65s on
 Docker 29.7.2.) A container `unhealthy` with `connection refused` in
 its health log, or a published port that resets connections, is this.

-The app runs as a non-root user (`webhooker`, UID 1000), exposes port
-8080, and includes a health check against `/.well-known/healthcheck`.
-The `/var/lib/webhooker` volume holds all SQLite databases: the main
-application database (`webhooker.db`), the per-webhook event databases
-(`events-{uuid}.db`), and any archive databases written by `database`
-targets (`archive-{uuid}.db`). Mount this as a persistent volume to
-preserve data across container restarts.
+The container runs as a non-root user (`webhooker`, UID 1000), exposes
+port 8080, and includes a health check against
+`/.well-known/healthcheck`. The `/var/lib/webhooker` volume holds all
+SQLite databases: the main application database (`webhooker.db`), the
+per-webhook event databases (`events-{uuid}.db`), and any archive
+databases written by `database` targets (`archive-{uuid}.db`). Mount
+this as a persistent volume to preserve data across container
+restarts.

-**The container sets its data directory's owner and mode itself
-before the app starts**, so a host directory can be mounted as it is,
-whoever owns it. The image's `ENTRYPOINT`,
-`deploy/docker-entrypoint.sh`, starts as root, creates `DATA_DIR` if
-it is missing, gives the directory and anything in it that belongs to
-another user to `webhooker`, sets the directory to `0750`, and only
-then runs the app as `webhooker`. Started with `--user`, it changes
-nothing and runs the app as that user.
+**The bind-mounted directory must be owned by UID 1000, or the
+container does not start.** Docker creates a `-v` source path that
+does not exist yet as `root:root`, and the process runs as UID 1000,
+so it cannot take its `DATA_DIR` lock:
+
+```
+webhooker: locking data directory /var/lib/webhooker: open
+/var/lib/webhooker/webhooker.lock: permission denied
+```
+
+It exits non-zero at that point, before opening any database. Create
+the directory ahead of the first `docker run`:
+
+```bash
+mkdir -p /path/to/data
+chown 1000:1000 /path/to/data
+chmod 750 /path/to/data
+```
+
+The same `chown` is what a restore needs — see step 4 of
+[Restore](#restore). A **named volume** does not have this problem:
+Docker copies the image's ownership onto a volume it initializes, and
+the image creates `/var/lib/webhooker` owned by `webhooker`.

 **The file modes are not yours to set, and do not depend on the
 directory.** `webhooker.db` holds target configuration in plaintext —
@@ -714,10 +729,13 @@ bearer tokens, API keys, Slack webhook URLs — along with the session
 encryption key, so webhooker creates every SQLite file it owns `0600`:
 each database and both of its `-wal` and `-shm` sidecars, across all
 three tiers. Files an earlier build left `0644` are tightened when
-they are opened. The directory's `0750` is defence in depth — it stops
-other local users listing the directory and learning your webhook
-UUIDs from the `events-{uuid}.db` filenames — not the barrier
-protecting the credentials.
+they are opened. A `DATA_DIR` webhooker creates itself is `0750`, but
+a bind mount supplies its own directory and Docker's default for one
+it creates is `0755`; the `0600` files hold there regardless. The
+`chmod 750` above is defence in depth — it stops other local users
+listing the directory and learning your webhook UUIDs from the
+`events-{uuid}.db` filenames — not the barrier protecting the
+credentials.

 ### Running under upaas

@@ -733,6 +751,17 @@ repository's `Dockerfile` and runs it. The app needs:
  app name, port `8080`. Leave `PORT` unset: the image's health check
  probes `8080`.
 - **Volume:** one host directory mounted at `/var/lib/webhooker`.
+  upaas bind-mounts the host path it is given and does not create it,
+  and the container does not start unless UID 1000 owns it (see
+  [Running with Docker](#running-with-docker)). Create it before the
+  first deploy:
+
+    ```bash
+    mkdir -p /path/to/data
+    chown 1000:1000 /path/to/data
+    chmod 750 /path/to/data
+    ```
+
 - **Environment variables:**
    - `WEBHOOKER_ENVIRONMENT=prod`
    - `TRUSTED_PROXIES`: your reverse proxy's address on that Docker
@@ -991,12 +1020,12 @@ done
 `.backup` reads through the WAL and writes a single consistent file with
 no sidecars of its own, so the destination is complete as it stands.
 Two caveats. First, the runtime image is `alpine:3.21` with only
-`ca-certificates` and `su-exec` added — the `sqlite3` CLI is **not** in
-it, so run this on the host against the volume path, or from a
-throwaway container that mounts the volume. Second, each file is
-captured at its own instant, so a webhook created or an event delivered
-between two files being copied lands in one and not the other. If you
-need the whole set coherent as of a single moment, stop the service.
+`ca-certificates` added — the `sqlite3` CLI is **not** in it, so run
+this on the host against the volume path, or from a throwaway container
+that mounts the volume. Second, each file is captured at its own
+instant, so a webhook created or an event delivered between two files
+being copied lands in one and not the other. If you need the whole set
+coherent as of a single moment, stop the service.

 Note that `sqlite3 <db> .dump` is **not** one of these procedures: it is
 an export, it holds a read transaction open for as long as it runs, and
@@ -1050,11 +1079,21 @@ with any `-wal`/`-shm` beside it, or wait until there are none.
   archive not opened since a crash. A copy salvaged from a crashed
   instance has them for everything, and needs all of them.

-4. Start the service. The container gives the directory and the
-   restored files to the `webhooker` user before the app starts,
-   whoever restored them (see
-   [Running with Docker](#running-with-docker)). `AutoMigrate` runs
-   against each restored database as it is opened.
+4. **Fix ownership.** The container runs as the non-root `webhooker`
+   user, UID 1000 / GID 1000. Restored files must be owned by (or
+   writable by) that UID, and so must the directory itself — SQLite
+   creates the `-wal` and `-shm` sidecars beside the database, so a
+   writable file inside a directory it cannot write is not enough:
+
+    ```bash
+    chown -R 1000:1000 /path/to/data
+    ```
+
+    Restoring as `root` on the host and forgetting this step is the
+    usual way a restore fails.
+
+5. Start the service. `AutoMigrate` runs against each restored database
+   as it is opened.

 ### Upgrades

@@ -1433,7 +1472,7 @@ A registered user of the webhooker service.
 | Field      | Type     | Description |
 | ---------- | -------- | ----------- |
 | `id`       | UUID     | Primary key |
-| `username` | string   | Unique login name |
+| `username` | string   | Unique login name, at most 1024 bytes so that it fits in the session cookie |
 | `password` | string   | Argon2id hash (never exposed via API) |

 **Relations:** Has many Webhooks. Has many APIKeys.
@@ -2373,14 +2412,14 @@ Removing either cap fails 14 subtests.

 `internal/middleware/logbound_test.go` and
 `internal/handlers/logbound_test.go` drive 8 KB of client-chosen text
-at each of these — 1 KB at `invalid password`, whose accounts are
-shared with the successful-login line, where a username past 4 KB
-overflows the session cookie and answers 500 before that line is
-written — through both handlers, and through seven fills: plain text
-as the baseline, and then the quotation mark, backslash, tab, newline,
-C0 control and astral non-printable, six characters the wider of the
-two handlers spends more on than the client spent sending them. Every
-case holds each line to the 2,560-byte ceiling. That per-line ceiling
+at each of these — just under 1 KB at `invalid password`, whose
+accounts are shared with the successful-login line and so must stay
+within the 1024-byte username limit — through both handlers, and
+through seven fills: plain text as the baseline, and then the
+quotation mark, backslash, tab, newline, C0 control and astral
+non-printable, six characters the wider of the two handlers spends
+more on than the client spent sending them. Every case holds each
+line to the 2,560-byte ceiling. That per-line ceiling
 is what the figure above states, and every row establishes it.

 Three of the sites go further and bound the whole flood's output — the
@@ -2682,7 +2721,7 @@ abuse limit later; they are tracked as future work.
 | ------ | --------------------------- | ----------- |
 | `GET`  | `/`                         | Root redirect, 303 (authenticated → `/sources`, unauthenticated → `/pages/login`) |
 | `GET`  | `/.well-known/healthcheck`  | Health check (JSON: `status`, `now`, `uptimeSeconds`, `uptimeHuman`, `version`, `appname`, `maintenanceMode`) |
-| `GET`, `HEAD` | `/s/*`              | Static file serving (embedded CSS, JS). `GET` and `HEAD` only — `POST`, `PUT`, `PATCH`, `DELETE`, `OPTIONS`, `TRACE` and `CONNECT` are answered `405 Method Not Allowed` with `Allow: GET, HEAD`. Any other method (such as `PROPFIND`) is refused by chi before it reaches this route, and gets `405` without an `Allow` header. Pinned by `TestStaticServesOnlyGetAndHead` |
+| any    | `/s/*`                      | Static file serving (embedded CSS, JS). Mounted for every method, not just `GET`/`HEAD`: chi's `Mount` registers all methods and `http.FileServer` special-cases only `HEAD` (by omitting the body), so a `POST` or `DELETE` to an asset is answered `200` with the file. Pinned by `TestStaticServesEveryMethod` |
 | `POST` | `/webhook/{uuid}`           | Webhook receiver endpoint. `POST` only — every other method is answered `405 Method Not Allowed` with `Allow: POST`. Rate limited (see [Rate Limiting](#rate-limiting)) |

 #### Authentication Endpoints
@@ -3032,11 +3071,7 @@ check, see [The login endpoint](#the-login-endpoint).
 - Prometheus metrics behind basic auth
 - Static assets embedded in binary (no filesystem access needed at
  runtime)
- The app runs as the non-root `webhooker` user (UID 1000) in the
-  container. The image sets no `USER`, so these run as root: the
-  `ENTRYPOINT` script, which sets the data directory's owner and mode
-  before the app starts; the image's health check; and `docker exec`,
-  unless given `--user`
+- Container runs as non-root user (UID 1000)
 - GORM soft deletes on every entity that carries `BaseModel`, which is
  all of them but `Setting` (data preserved for audit)

@@ -3163,13 +3198,10 @@ version is fixed independently of the compiler's:
   `GO_LDFLAGS`, so neither can drop the `-X` that stamps the version.
   The version arrives as the `VERSION` build arg, since the context
   has no `.git` (see [Version stamping](#version-stamping)).
-3. **Runtime stage** (`alpine:3.21`) — copies the static binary and
-   `deploy/docker-entrypoint.sh`, creates the `/var/lib/webhooker`
-   directory for all SQLite databases, exposes port 8080, and includes
-   a health check against `/.well-known/healthcheck`. It sets no
-   `USER`: the `ENTRYPOINT` script starts as root, sets the data
-   directory's owner and mode, and runs the app as the non-root
-   `webhooker` user (UID 1000) through `su-exec`.
+3. **Runtime stage** (`alpine:3.21`) — copies the static binary,
+   creates the `/var/lib/webhooker` directory for all SQLite databases,
+   runs as the non-root `webhooker` user (UID 1000), exposes port 8080,
+   and includes a health check against `/.well-known/healthcheck`.

 The lint stage invokes `golangci-lint` directly rather than `make lint`:
 it is already the pinned linter image, and `make lint` builds
@@ -3248,5 +3280,3 @@ MIT
 ## Author

 [@sneak](https://sneak.berlin)
-
-
@@ -1,22 +0,0 @@
-#!/bin/sh
-# deploy/docker-entrypoint.sh: the image's ENTRYPOINT. A bind-mounted
-# data directory keeps its owner from the host, often root, and the app
-# could not write to it. Started as root, this creates DATA_DIR if
-# needed, gives it and everything in it to webhooker, sets its mode, and
-# runs the command as webhooker, so the app never runs as root. Started
-# as another user, it only runs the command.
-set -eu
-
-main() {
-    if [ "$(id -u)" != 0 ]; then
-        exec "$@"
-    fi
-
-    dir="${DATA_DIR:-/var/lib/webhooker}"
-    mkdir -p "$dir"
-    find "$dir" ! -user webhooker -exec chown -h webhooker:webhooker {} +
-    chmod 750 "$dir"
-    exec su-exec webhooker "$@"
-}
-
-main "$@"
@@ -1,13 +1,57 @@
 package database

+import (
+	"errors"
+	"fmt"
+
+	"gorm.io/gorm"
+)
+
+// MaxUsernameBytes is the longest username, in bytes, that a user may
+// have. The same number appears in the check constraint on
+// User.Username, because a struct tag cannot reference a constant.
+//
+// A login stores the username in the session cookie, and both
+// securecookie and browsers refuse a cookie value past about 4096
+// bytes. That value is the session base64-encoded twice, so it holds
+// 4096 × 3/4 × 3/4 = 2304 bytes of session, and the signature,
+// timestamp and the session's other values take about 270 of those: a
+// username longer than about 2030 bytes can never log in. The limit is
+// about half that, so the session can carry more values later without
+// locking out an account whose username is already at the limit.
+const MaxUsernameBytes = 1024
+
+// ErrUsernameTooLong is returned when a user is saved with a username
+// longer than MaxUsernameBytes.
+var ErrUsernameTooLong = errors.New("username is too long")
+
 // User represents a user of the webhooker service
+//
+//nolint:lll // a struct tag cannot wrap
 type User struct {
 	BaseModel

-	Username string `gorm:"uniqueIndex;not null" json:"username"`
+	Username string `gorm:"uniqueIndex;not null;check:length(CAST(username AS BLOB)) <= 1024" json:"username"`
 	Password string `gorm:"not null"                                                          json:"-"` // Argon2 hashed

 	// Relations
 	Webhooks []Webhook `json:"webhooks,omitempty"`
 	APIKeys  []APIKey  `json:"apiKeys,omitempty"`
 }
+
+// BeforeSave rejects a username longer than MaxUsernameBytes, so every
+// path that saves a user through GORM gets ErrUsernameTooLong rather
+// than the database's constraint error. The check constraint behind it
+// holds for any path that writes the table without this model.
+func (u *User) BeforeSave(_ *gorm.DB) error {
+	if len(u.Username) > MaxUsernameBytes {
+		return fmt.Errorf(
+			"%w: %d bytes, limit is %d",
+			ErrUsernameTooLong,
+			len(u.Username),
+			MaxUsernameBytes,
+		)
+	}
+
+	return nil
+}
@@ -0,0 +1,65 @@
+package database_test
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+// usernameAtLimit is exactly MaxUsernameBytes long, built from a
+// two-byte character. A check that counted characters rather than bytes
+// would see half the length and let the one-byte-longer name through.
+func usernameAtLimit() string {
+	return strings.Repeat("é", database.MaxUsernameBytes/2)
+}
+
+func TestUserCreate_RejectsOverlongUsername(t *testing.T) {
+	t.Parallel()
+
+	db := startedTestDB(t)
+
+	err := db.Create(&database.User{
+		Username: usernameAtLimit() + "x",
+		Password: "hash",
+	}).Error
+
+	require.ErrorIs(t, err, database.ErrUsernameTooLong)
+}
+
+func TestUserCreate_AcceptsUsernameAtLimit(t *testing.T) {
+	t.Parallel()
+
+	db := startedTestDB(t)
+
+	require.NoError(t, db.Create(&database.User{
+		Username: usernameAtLimit(),
+		Password: "hash",
+	}).Error)
+}
+
+// TestUsersTable_EnforcesUsernameLimitWithoutTheModel inserts with raw
+// SQL, as a path that bypassed User.BeforeSave would, so only the
+// table's check constraint stands between it and an over-long
+// username. Accepting the name at the limit and refusing the next byte
+// also pins the constraint's number to MaxUsernameBytes.
+func TestUsersTable_EnforcesUsernameLimitWithoutTheModel(t *testing.T) {
+	t.Parallel()
+
+	db := startedTestDB(t)
+
+	insert := "INSERT INTO users (id, username, password) VALUES (?, ?, ?)"
+
+	require.NoError(t, db.Exec(
+		insert, uuid.New().String(), usernameAtLimit(), "hash",
+	).Error)
+
+	err := db.Exec(
+		insert, uuid.New().String(), usernameAtLimit()+"x", "hash",
+	).Error
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "CHECK constraint failed")
+}
@@ -453,3 +453,33 @@ func TestLogin_SuccessCreatesSession(t *testing.T) {
 		"the issued cookie must carry an authenticated session",
 	)
 }
+
+// TestLogin_UsernameAtLimitCanLogIn shows that a username of exactly
+// database.MaxUsernameBytes still fits in the session cookie. Past
+// what the cookie can carry, a correct login answers 500.
+func TestLogin_UsernameAtLimitCanLogIn(t *testing.T) {
+	t.Parallel()
+
+	var (
+		h  *handlers.Handlers
+		db *database.Database
+	)
+
+	app := newTestApp(t, &h, &db)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	username := strings.Repeat("a", database.MaxUsernameBytes)
+
+	hash, err := database.HashPassword(operatorPassword)
+	require.NoError(t, err)
+	require.NoError(t, db.DB().Create(&database.User{
+		Username: username,
+		Password: hash,
+	}).Error)
+
+	w := submitLogin(h, sharedProxyPeer, username, operatorPassword)
+
+	assert.Equal(t, http.StatusSeeOther, w.Code)
+}
@@ -339,11 +339,9 @@ const storedUserPassword = "correct-horse-battery-staple"
 // storedFillBytes is the raw length of the client-chosen value in
 // those accounts' usernames. It is well past the 512-byte field
 // budget, so the line is still truncated, but short enough that the
-// session cookie a successful login writes stays inside
-// securecookie's 4 KB limit: the cookie is written BEFORE the
-// "user logged in" line, so an 8 KB username answers 500 and never
-// reaches it.
-const storedFillBytes = 1024
+// whole username, markers and fill name included, stays within
+// database.MaxUsernameBytes.
+const storedFillBytes = 960

 // storedFill builds a username fill of storedFillBytes raw bytes out
 // of repetitions of ch, with both markers at its far end.
@@ -92,25 +92,11 @@ func (s *Server) setupGlobalMiddleware() {
 func (s *Server) setupRoutes() {
 	s.router.Get("/", s.h.HandleIndex())

-	// Static assets answer GET and HEAD only. chi's default 405
-	// carries no Allow header, so this group supplies its own.
-	staticFiles := http.StripPrefix(
-		"/s", http.FileServer(http.FS(static.Static)),
+	s.router.Mount(
+		"/s",
+		http.StripPrefix("/s", http.FileServer(http.FS(static.Static))),
 	)

-	s.router.Route("/s", func(r chi.Router) {
-		r.MethodNotAllowed(func(w http.ResponseWriter, _ *http.Request) {
-			w.Header().Set("Allow", "GET, HEAD")
-			http.Error(
-				w,
-				"Method Not Allowed",
-				http.StatusMethodNotAllowed,
-			)
-		})
-		r.Method(http.MethodGet, "/*", staticFiles)
-		r.Method(http.MethodHead, "/*", staticFiles)
-	})
-
 	s.router.Route("/api/v1", func(_ chi.Router) {
 		// API routes will be added here.
 	})
@@ -396,15 +396,13 @@ func (e *testEnv) storedHash(t *testing.T, username string) string {

 // --- /s static group ---

-// TestStaticServesOnlyGetAndHead pins the methods the static group
-// answers: GET and HEAD are served the asset, and the other methods
-// chi routes (POST, PUT, DELETE and the rest) are refused with 405
-// and an Allow header naming those two. A method chi does not route,
-// such as PROPFIND, is refused with 405 by the top-level router
-// before it reaches the static group, so it gets no Allow header.
-// The README documents this; the test is what keeps the two from
-// drifting.
-func TestStaticServesOnlyGetAndHead(t *testing.T) {
+// TestStaticServesEveryMethod pins what the static mount actually
+// answers. chi's Mount registers the handler for all methods and
+// http.FileServer only special-cases HEAD (by suppressing the body),
+// so a POST or a DELETE to an asset is served the file rather than
+// refused. The README documents this; the test is what keeps the two
+// from drifting.
+func TestStaticServesEveryMethod(t *testing.T) {
 	t.Parallel()

 	env := newTestEnv(t)
@@ -419,7 +417,6 @@ func TestStaticServesOnlyGetAndHead(t *testing.T) {
 		http.MethodPost,
 		http.MethodPut,
 		http.MethodDelete,
-		"PROPFIND",
 	} {
 		t.Run(method, func(t *testing.T) {
 			t.Parallel()
@@ -431,38 +428,18 @@ func TestStaticServesOnlyGetAndHead(t *testing.T) {
 			w := httptest.NewRecorder()
 			env.router.ServeHTTP(w, req)

-			switch method {
-			case http.MethodGet:
-				assert.Equal(t, http.StatusOK, w.Code)
-				assert.Equal(t, body, w.Body.Bytes(),
-					"the asset itself is returned")
-			case http.MethodHead:
-				assert.Equal(t, http.StatusOK, w.Code)
+			assert.Equal(t, http.StatusOK, w.Code,
+				"static mount answers every method")
+
+			if method == http.MethodHead {
 				assert.Empty(t, w.Body.Bytes(),
 					"HEAD must not carry a body")
-			case "PROPFIND":
-				assert.Equal(
-					t, http.StatusMethodNotAllowed, w.Code,
-				)
-				assert.Empty(t, w.Header().Get("Allow"),
-					"chi refuses a method it does not route "+
-						"before the static group runs")
-				assert.NotContains(
-					t, w.Body.String(), string(body),
-					"a refused method must not get the asset",
-				)
-			default:
-				assert.Equal(
-					t, http.StatusMethodNotAllowed, w.Code,
-				)
-				assert.Equal(
-					t, "GET, HEAD", w.Header().Get("Allow"),
-				)
-				assert.NotContains(
-					t, w.Body.String(), string(body),
-					"a refused method must not get the asset",
-				)
+
+				return
 			}
+
+			assert.Equal(t, body, w.Body.Bytes(),
+				"the asset itself is returned")
 		})
 	}
 }