Files
webhooker/internal/handlers/handlers_test.go
sneak 15ada44902
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Add an egress CIDR allowlist to the SSRF guard (closes #204)
The SSRF blocklist had no escape hatch, so the thing webhooker is
mostly for — taking a public webhook and forwarding it to something
on your own network — could not be configured at all. Every private
address, Docker sibling and loopback service was permanently
unreachable as a delivery destination.

ALLOWED_EGRESS_CIDRS (default empty) names blocks that delivery
targets may reach despite the default blocklist. It is an allowlist
and only ever adds destinations: there is no boolean, and no value
disables SSRF protection wholesale. Empty, the guard behaves exactly
as before.

A fixed set of addresses is refused before the allowlist is
consulted, so no supplied CIDR opens one — not the exact address,
not a supernet, not 0.0.0.0/0 or ::/0. It is the two link-local
blocks (169.254.0.0/16, fe80::/10) plus host routes for the cloud
metadata endpoints that sit outside them: AWS's IPv6 IMDS at
fd00:ec2::254, which lives in ordinary ULA space, and Alibaba's
100.100.100.200, which lives in CGNAT. Allowlisting fd00::/8 or
100.64.0.0/10 (Tailscale's range) is an ordinary thing for an
operator to do and must not reopen instance-credential theft. The
IPv4-compatible (::a9fe:a9fe) and NAT64 (64:ff9b::a9fe:a9fe)
spellings of 169.254.169.254 are listed too, because To4() does not
normalise them into the link-local block the way it does the
IPv4-mapped form. Reaching any of these is credential theft rather
than delivery to an internal service.

The policy now lives in one function, Guard.checkIP, which both
target-creation validation and the delivery dialer call. The two
paths previously decided separately, which is how they came to
disagree about a destination. The guard is built once from config
and injected via fx into both the handlers and the delivery engine,
so there is a single instance and a single answer.

A set-but-unparseable value aborts startup naming the variable,
reusing the existing envPrefixList parser. A non-empty list is
logged at startup with the blocks spelled out, not counted, so the
hole is visible in the log of any deployment that has one.

Tests: an allowlisted loopback CIDR both validates and delivers to a
live server (and the same URL still fails without the allowlist); a
private address outside the listed block stays refused on both
paths; every unconditionally blocked address stays refused on both
paths under an allowlist that covers it, and the set itself is
pinned entry by entry; public addresses are unaffected either way;
and config coverage for parsing, startup abort, and the warning's
contents.
2026-08-20 06:28:54 +00:00

369 lines
8.4 KiB
Go

package handlers_test
import (
"context"
"errors"
"html/template"
"net/http"
"net/http/httptest"
"sync"
"testing"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
"go.uber.org/fx"
"go.uber.org/fx/fxtest"
"sneak.berlin/go/webhooker/internal/config"
"sneak.berlin/go/webhooker/internal/database"
"sneak.berlin/go/webhooker/internal/delivery"
"sneak.berlin/go/webhooker/internal/globals"
"sneak.berlin/go/webhooker/internal/handlers"
"sneak.berlin/go/webhooker/internal/healthcheck"
"sneak.berlin/go/webhooker/internal/logger"
"sneak.berlin/go/webhooker/internal/middleware"
"sneak.berlin/go/webhooker/internal/session"
)
// recordingNotifier is a delivery.Notifier that records the tasks it
// was handed, so a test can prove a handler queued the delivery it
// claims to have queued — and, on the refusal paths, that it queued
// nothing.
type recordingNotifier struct {
mu sync.Mutex
tasks []delivery.Task
}
func (n *recordingNotifier) Notify(tasks []delivery.Task) {
n.mu.Lock()
defer n.mu.Unlock()
n.tasks = append(n.tasks, tasks...)
}
// Tasks returns a copy of the recorded tasks.
func (n *recordingNotifier) Tasks() []delivery.Task {
n.mu.Lock()
defer n.mu.Unlock()
out := make([]delivery.Task, len(n.tasks))
copy(out, n.tasks)
return out
}
// recordingEvictor is a delivery.WebhookEvictor that records
// the webhook ids it was asked to evict, so a test can prove
// that a deletion path reached the delivery engine.
type recordingEvictor struct {
mu sync.Mutex
evicted []string
}
func (r *recordingEvictor) EvictWebhook(webhookID string) {
r.mu.Lock()
defer r.mu.Unlock()
r.evicted = append(r.evicted, webhookID)
}
// Evicted returns a copy of the recorded webhook ids.
func (r *recordingEvictor) Evicted() []string {
r.mu.Lock()
defer r.mu.Unlock()
out := make([]string, len(r.evicted))
copy(out, r.evicted)
return out
}
func newTestApp(
t *testing.T,
targets ...any,
) *fxtest.App {
t.Helper()
return fxtest.New(
t,
fx.Provide(
globals.New,
logger.New,
func() *config.Config {
return &config.Config{
DataDir: t.TempDir(),
}
},
database.New,
database.NewWebhookDBManager,
healthcheck.New,
session.New,
func() *recordingNotifier {
return &recordingNotifier{}
},
func(n *recordingNotifier) delivery.Notifier {
return n
},
func() *recordingEvictor {
return &recordingEvictor{}
},
func(r *recordingEvictor) delivery.WebhookEvictor {
return r
},
middleware.New,
delivery.NewGuard,
handlers.New,
),
fx.Populate(targets...),
)
}
func TestHandleIndex_Unauthenticated(t *testing.T) {
t.Parallel()
var h *handlers.Handlers
app := newTestApp(t, &h)
app.RequireStart()
t.Cleanup(app.RequireStop)
req := httptest.NewRequestWithContext(
context.Background(), http.MethodGet, "/", nil)
w := httptest.NewRecorder()
handler := h.HandleIndex()
handler.ServeHTTP(w, req)
assert.Equal(t, http.StatusSeeOther, w.Code)
assert.Equal(
t, "/pages/login", w.Header().Get("Location"),
)
}
func TestHandleIndex_Authenticated(t *testing.T) {
t.Parallel()
var h *handlers.Handlers
var sess *session.Session
app := newTestApp(t, &h, &sess)
app.RequireStart()
t.Cleanup(app.RequireStop)
req := httptest.NewRequestWithContext(
context.Background(), http.MethodGet, "/", nil)
w := httptest.NewRecorder()
s, err := sess.Get(req)
require.NoError(t, err)
sess.SetUser(s, "test-user-id", "testuser")
err = sess.Save(req, w, s)
require.NoError(t, err)
req2 := httptest.NewRequestWithContext(
context.Background(), http.MethodGet, "/", nil)
for _, cookie := range w.Result().Cookies() {
req2.AddCookie(cookie)
}
w2 := httptest.NewRecorder()
h.HandleIndex().ServeHTTP(w2, req2)
assert.Equal(t, http.StatusSeeOther, w2.Code)
assert.Equal(
t, "/sources", w2.Header().Get("Location"),
)
}
func TestBuildSlackTargetConfig_AcceptsPublicURL(t *testing.T) {
t.Parallel()
var h *handlers.Handlers
app := newTestApp(t, &h)
app.RequireStart()
t.Cleanup(app.RequireStop)
req := httptest.NewRequestWithContext(
context.Background(), http.MethodPost, "/", nil)
w := httptest.NewRecorder()
cfg, err := h.BuildSlackTargetConfigForTest(
w, req, "http://93.184.216.34/services/T00/B00/xxx",
)
require.NoError(t, err)
assert.Equal(t, http.StatusOK, w.Code)
assert.Contains(t, cfg, "webhookUrl")
}
func TestBuildSlackTargetConfig_RejectsReservedURL(t *testing.T) {
t.Parallel()
var h *handlers.Handlers
app := newTestApp(t, &h)
app.RequireStart()
t.Cleanup(app.RequireStop)
req := httptest.NewRequestWithContext(
context.Background(), http.MethodPost, "/", nil)
w := httptest.NewRecorder()
cfg, err := h.BuildSlackTargetConfigForTest(
w, req, "http://169.254.169.254/latest/meta-data/",
)
require.Error(t, err)
assert.Empty(t, cfg)
assert.Equal(t, http.StatusBadRequest, w.Code)
}
func TestRenderTemplate(t *testing.T) {
t.Parallel()
var h *handlers.Handlers
app := newTestApp(t, &h)
app.RequireStart()
t.Cleanup(app.RequireStop)
req := httptest.NewRequestWithContext(
context.Background(), http.MethodGet, "/", nil)
w := httptest.NewRecorder()
data := map[string]any{"Version": "1.0.0"}
h.RenderTemplateForTest(
w, req, "nonexistent.html", data,
)
assert.Equal(
t, http.StatusInternalServerError, w.Code,
)
}
// errMidRender is the failure a test template raises partway through
// rendering.
var errMidRender = errors.New("deliberate mid-render failure")
// midRenderFailure is template data whose first method renders and
// whose second fails, so the template aborts after output has
// already been produced.
type midRenderFailure struct{}
// Prefix is the output a streaming renderer would flush before the
// failure below aborts the template.
func (midRenderFailure) Prefix() string { return partialPageMarker }
// Boom aborts template execution.
func (midRenderFailure) Boom() (string, error) {
return "", errMidRender
}
// partialPageMarker is content the failing template emits before it
// aborts.
const partialPageMarker = "PARTIAL PAGE CONTENT"
// TestRenderTemplateMidRenderErrorSendsNoPartialBody proves the
// renderer does not commit output it cannot finish: a template that
// fails partway through must yield a 500 and a body carrying none of
// the content emitted before the failure. Against a renderer that
// executes straight into the ResponseWriter this fails on both
// counts, returning 200 with the prefix already flushed.
func TestRenderTemplateMidRenderErrorSendsNoPartialBody(t *testing.T) {
t.Parallel()
var h *handlers.Handlers
app := newTestApp(t, &h)
app.RequireStart()
t.Cleanup(app.RequireStop)
h.AddTemplateForTest("failing.html", template.Must(
template.New("failing").Parse(
`{{.Data.Prefix}}{{.Data.Boom}}TAIL`,
),
))
req := httptest.NewRequestWithContext(
context.Background(), http.MethodGet, "/", nil)
w := httptest.NewRecorder()
h.RenderTemplateForTest(
w, req, "failing.html", midRenderFailure{},
)
assert.Equal(
t, http.StatusInternalServerError, w.Code,
"a failed render must report a 500",
)
assert.Equal(
t, "Internal server error\n", w.Body.String(),
"the response must carry no part of the aborted page",
)
}
func TestBuildDatabaseTargetConfig_Valid(t *testing.T) {
t.Parallel()
var h *handlers.Handlers
app := newTestApp(t, &h)
app.RequireStart()
t.Cleanup(app.RequireStop)
// Empty expiry: the keep-forever default, empty config.
w := httptest.NewRecorder()
cfg, err := h.BuildDatabaseTargetConfigForTest(w, "")
require.NoError(t, err)
assert.Empty(t, cfg)
// Explicit never is stored as config.
w = httptest.NewRecorder()
cfg, err = h.BuildDatabaseTargetConfigForTest(w, "never")
require.NoError(t, err)
assert.JSONEq(t, `{"expiry":"never"}`, cfg)
// A positive duration is stored as config.
w = httptest.NewRecorder()
cfg, err = h.BuildDatabaseTargetConfigForTest(w, "720h")
require.NoError(t, err)
assert.JSONEq(t, `{"expiry":"720h"}`, cfg)
}
func TestBuildDatabaseTargetConfig_RejectsBadExpiry(
t *testing.T,
) {
t.Parallel()
var h *handlers.Handlers
app := newTestApp(t, &h)
app.RequireStart()
t.Cleanup(app.RequireStop)
for _, bad := range []string{"nonsense", "7d", "-5h"} {
w := httptest.NewRecorder()
cfg, err := h.BuildDatabaseTargetConfigForTest(w, bad)
require.Error(t, err, "expiry %q", bad)
assert.Empty(t, cfg)
assert.Equal(
t, http.StatusBadRequest, w.Code,
"expiry %q should be rejected with 400", bad,
)
}
}