Merge pull request 'fix #63: require deletion token on DELETE /api/pastes/{id}' (#79) from issue-63-delete-auth into main

- DELETE now demands the create-time deletion token (Authorization
  header: Bearer/Token/bare, or ?token= query param), compared with
  the constant-time store.DeletionTokenEqual. 403 otherwise.
- Creator-browser deletes via the /mine button (matching vwr cookie,
  #37) remain allowed; other browsers and plain API clients get 403.
- Regression tests: no token, wrong token (header+query), correct
  token (header+query), creator-cookie path, token extraction.
- Adapted TestSoftDelete to pass the deletion token.
- docs/API.md delete section updated.
- Based on #58's SoftDelete (bool, error) signature.

docs/API.md

@@ -54,8 +54,10 @@ Raw reads count against a burn-after-read budget, same as page views.
 ## Delete
 
 ```bash
-# soft delete (creator browser only; plain API clients unaffected)
-curl -X DELETE http://localhost:8080/api/pastes/{id}
+# soft delete (requires the deletion token from the create response)
+curl -X DELETE -H "Authorization: Bearer TOKEN" http://localhost:8080/api/pastes/{id}
+# ...or via query param; the creator browser (viewer cookie) may also delete without a token
+curl -X DELETE "http://localhost:8080/api/pastes/{id}?token=TOKEN"
 
 # hard delete immediately (requires the one-time deletion token)
 curl -X DELETE "http://localhost:8080/api/pastes/{id}/redeem?token=TOKEN"

internal/api/delete_auth_test.go

@@ -0,0 +1,172 @@
+package api
+
+// Regression tests for #63: DELETE /api/pastes/{id} must require the
+// deletion token (Authorization header or ?token= query param, constant-time
+// compare). Without a token, or with a wrong token, the paste must survive
+// and the response must be 403.
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+// createTestPaste creates a paste via the API and returns id + deletion token.
+func createTestPaste(t *testing.T, h http.Handler) (string, string) {
+	t.Helper()
+	req := httptest.NewRequest("POST", "/api/pastes", strings.NewReader(`{"content":"delete me"}`))
+	req.Header.Set("Content-Type", "application/json")
+	rec := httptest.NewRecorder()
+	h.ServeHTTP(rec, req)
+	if rec.Code != 201 {
+		t.Fatalf("create: got %d want 201: %s", rec.Code, rec.Body.String())
+	}
+	var created struct {
+		ID            string `json:"id"`
+		DeletionToken string `json:"deletion_token"`
+	}
+	json.Unmarshal(rec.Body.Bytes(), &created)
+	if created.ID == "" || created.DeletionToken == "" {
+		t.Fatalf("create response missing id/deletion_token: %s", rec.Body.String())
+	}
+	return created.ID, created.DeletionToken
+}
+
+func pasteExists(t *testing.T, h http.Handler, id string) bool {
+	t.Helper()
+	req := httptest.NewRequest("GET", "/api/pastes/"+id, nil)
+	rec := httptest.NewRecorder()
+	h.ServeHTTP(rec, req)
+	if rec.Code == 200 {
+		return true
+	}
+	if rec.Code == 404 {
+		return false
+	}
+	t.Fatalf("get after delete: got %d", rec.Code)
+	return false
+}
+
+func TestDeleteWithoutTokenForbidden(t *testing.T) {
+	s := testServer(t)
+	h := s.routes()
+	id, _ := createTestPaste(t, h)
+
+	rec := doReq(t, h, "DELETE", "/api/pastes/"+id, "", "")
+	if rec.Code != http.StatusForbidden {
+		t.Fatalf("delete without token: got %d want 403", rec.Code)
+	}
+	if !pasteExists(t, h, id) {
+		t.Fatal("paste was deleted without a token")
+	}
+}
+
+func TestDeleteWithWrongTokenForbidden(t *testing.T) {
+	s := testServer(t)
+	h := s.routes()
+	id, _ := createTestPaste(t, h)
+
+	// query param
+	rec := doReq(t, h, "DELETE", "/api/pastes/"+id+"?token=wrong-token", "", "")
+	if rec.Code != http.StatusForbidden {
+		t.Fatalf("delete with wrong token (query): got %d want 403", rec.Code)
+	}
+	// header
+	req := httptest.NewRequest("DELETE", "/api/pastes/"+id, nil)
+	req.Header.Set("Authorization", "Bearer wrong-token")
+	rec = httptest.NewRecorder()
+	h.ServeHTTP(rec, req)
+	if rec.Code != http.StatusForbidden {
+		t.Fatalf("delete with wrong token (header): got %d want 403", rec.Code)
+	}
+	if !pasteExists(t, h, id) {
+		t.Fatal("paste was deleted with a wrong token")
+	}
+}
+
+func TestDeleteWithCorrectToken(t *testing.T) {
+	s := testServer(t)
+	h := s.routes()
+	id, tok := createTestPaste(t, h)
+
+	// via Authorization header
+	req := httptest.NewRequest("DELETE", "/api/pastes/"+id, nil)
+	req.Header.Set("Authorization", "Bearer "+tok)
+	rec := httptest.NewRecorder()
+	h.ServeHTTP(rec, req)
+	if rec.Code != 200 {
+		t.Fatalf("delete with correct token (header): got %d want 200: %s", rec.Code, rec.Body.String())
+	}
+	if pasteExists(t, h, id) {
+		t.Fatal("paste still exists after authorized delete")
+	}
+
+	// via query param
+	id, tok = createTestPaste(t, h)
+	rec = doReq(t, h, "DELETE", "/api/pastes/"+id+"?token="+tok, "", "")
+	if rec.Code != 200 {
+		t.Fatalf("delete with correct token (query): got %d want 200", rec.Code)
+	}
+	if pasteExists(t, h, id) {
+		t.Fatal("paste still exists after authorized delete (query)")
+	}
+}
+
+func TestDeleteByCreatorViewerCookieStillAllowed(t *testing.T) {
+	s := testServer(t)
+	h := s.routes()
+	// create from a specific browser
+	req := httptest.NewRequest("POST", "/api/pastes", strings.NewReader(`{"content":"mine"}`))
+	req.Header.Set("Content-Type", "application/json")
+	req.AddCookie(&http.Cookie{Name: "vwr", Value: "creator-abc"})
+	rec := httptest.NewRecorder()
+	h.ServeHTTP(rec, req)
+	var created struct {
+		ID string `json:"id"`
+	}
+	json.Unmarshal(rec.Body.Bytes(), &created)
+
+	// creator browser deletes without a token: allowed (#37 /mine delete button)
+	rec = doReq(t, h, "DELETE", "/api/pastes/"+created.ID, "creator-abc", "")
+	if rec.Code != 200 {
+		t.Fatalf("creator delete: got %d want 200", rec.Code)
+	}
+
+	// a different browser is still forbidden
+	id, _ := createTestPaste(t, h)
+	rec = doReq(t, h, "DELETE", "/api/pastes/"+id, "someone-else", "")
+	if rec.Code != http.StatusForbidden {
+		t.Fatalf("other browser delete: got %d want 403", rec.Code)
+	}
+	if !pasteExists(t, h, id) {
+		t.Fatal("paste deleted by unrelated browser")
+	}
+}
+
+func TestDeletionAuthorizationExtract(t *testing.T) {
+	mk := func(hdr, q string) *http.Request {
+		req := httptest.NewRequest("DELETE", "/api/pastes/x"+q, nil)
+		if hdr != "" {
+			req.Header.Set("Authorization", hdr)
+		}
+		return req
+	}
+	cases := []struct {
+		hdr, q, want string
+	}{
+		{"", "", ""},
+		{"Bearer tok", "", "tok"},
+		{"bearer tok", "", "tok"},
+		{"Token tok", "", "tok"},
+		{"tok", "", "tok"},
+		{"", "?token=q", "q"},
+		{"Bearer hdr", "?token=q", "hdr"}, // header wins
+	}
+	for _, c := range cases {
+		if got := deletionAuthorization(mk(c.hdr, c.q)); got != c.want {
+			t.Errorf("deletionAuthorization(hdr=%q q=%q) = %q want %q", c.hdr, c.q, got, c.want)
+		}
+	}
+}

internal/api/main_test.go

@@ -42,7 +42,9 @@ func TestCreateAndGetPaste(t *testing.T) {
 	if rec.Code != 201 {
 		t.Fatalf("create: got %d want 201: %s", rec.Code, rec.Body.String())
 	}
-	var created struct{ ID string `json:"id"` }
+	var created struct {
+		ID string `json:"id"`
+	}
 	json.Unmarshal(rec.Body.Bytes(), &created)
 	if len(created.ID) != 6 {
 		t.Fatalf("unexpected id: %q", created.ID)
@@ -73,7 +75,9 @@ func TestPasswordProtection(t *testing.T) {
 	req := httptest.NewRequest("POST", "/api/pastes", strings.NewReader(body))
 	rec := httptest.NewRecorder()
 	h.ServeHTTP(rec, req)
-	var created struct{ ID string `json:"id"` }
+	var created struct {
+		ID string `json:"id"`
+	}
 	json.Unmarshal(rec.Body.Bytes(), &created)
 
 	// without password -> 401
@@ -133,10 +137,14 @@ func TestSoftDelete(t *testing.T) {
 	req := httptest.NewRequest("POST", "/api/pastes", strings.NewReader(`{"content":"bye"}`))
 	rec := httptest.NewRecorder()
 	h.ServeHTTP(rec, req)
-	var created struct{ ID string `json:"id"` }
+	var created struct {
+		ID            string `json:"id"`
+		DeletionToken string `json:"deletion_token"`
+	}
 	json.Unmarshal(rec.Body.Bytes(), &created)
 
 	req = httptest.NewRequest("DELETE", "/api/pastes/"+created.ID, nil)
+	req.Header.Set("Authorization", "Bearer "+created.DeletionToken)
 	rec = httptest.NewRecorder()
 	h.ServeHTTP(rec, req)
 	if rec.Code != 200 {
@@ -182,7 +190,9 @@ func TestSweepSoftDeletesAfterGrace(t *testing.T) {
 	req := httptest.NewRequest("POST", "/api/pastes", strings.NewReader(`{"content":"gone soon"}`))
 	rec := httptest.NewRecorder()
 	h.ServeHTTP(rec, req)
-	var created struct{ ID string `json:"id"` }
+	var created struct {
+		ID string `json:"id"`
+	}
 	json.Unmarshal(rec.Body.Bytes(), &created)
 
 	s.store.SoftDelete(created.ID)
@@ -218,7 +228,9 @@ func TestRawEndpoint(t *testing.T) {
 	req := httptest.NewRequest("POST", "/api/pastes", strings.NewReader(`{"content":"raw content here"}`))
 	rec := httptest.NewRecorder()
 	h.ServeHTTP(rec, req)
-	var created struct{ ID string `json:"id"` }
+	var created struct {
+		ID string `json:"id"`
+	}
 	json.Unmarshal(rec.Body.Bytes(), &created)
 
 	req = httptest.NewRequest("GET", "/raw/"+created.ID, nil)

internal/api/server.go

@@ -237,12 +237,12 @@ func (a *apiServer) handleDeletePaste(w http.ResponseWriter, r *http.Request) {
 		writeErr(w, 404, "paste not found")
 		return
 	}
-	// viewer-cookie delete enforcement (#37): only the browser that created
-	// the paste (matching vwr) may delete it via this endpoint. Requests with
-	// no client-sent vwr cookie (plain API clients) are unaffected.
-	vid := currentViewerID(r)
-	if vid != "" && viewerSentCookie(r) && row.ViewerID.Valid && row.ViewerID.String != "" && row.ViewerID.String != vid {
-		writeErr(w, 403, "not your paste")
+	// #63: deletion requires authorization. Either the deletion token issued
+	// at create time (Authorization header or ?token= query param, matching
+	// the create response's "deletion_token" field), or the creator browser
+	// itself (client-sent vwr cookie matching the paste's viewer, #37).
+	if !a.deletionAuthorized(r, row) {
+		writeErr(w, 403, "deletion token required")
 		return
 	}
 	if _, err := a.store.SoftDelete(row.ID); err != nil {
@@ -252,6 +252,37 @@ func (a *apiServer) handleDeletePaste(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, 200, map[string]string{"status": "soft-deleted"})
 }
 
+// deletionAuthorization extracts the deletion token from the request: the
+// Authorization header ("Bearer <t>", "Token <t>", or a bare token) or the
+// token query parameter. Returns "" when absent.
+func deletionAuthorization(r *http.Request) string {
+	if h := r.Header.Get("Authorization"); h != "" {
+		for _, prefix := range []string{"Bearer ", "Token "} {
+			if len(h) > len(prefix) && strings.EqualFold(h[:len(prefix)], prefix) {
+				return strings.TrimSpace(h[len(prefix):])
+			}
+		}
+		return strings.TrimSpace(h)
+	}
+	return r.URL.Query().Get("token")
+}
+
+// deletionAuthorized reports whether the request may soft-delete the paste:
+// a valid constant-time-matched deletion token, or the creator browser's
+// viewer cookie (#37). Plain API clients with no token get false.
+func (a *apiServer) deletionAuthorized(r *http.Request, row *store.PasteRow) bool {
+	if tok := deletionAuthorization(r); tok != "" {
+		return row.DeletionToken.Valid && row.DeletionToken.String != "" &&
+			store.DeletionTokenEqual(row.DeletionToken.String, tok)
+	}
+	// viewer-cookie delete enforcement (#37): only the browser that created
+	// the paste (matching vwr) may delete it via this endpoint. Requests with
+	// no client-sent vwr cookie (plain API clients) are unaffected.
+	vid := currentViewerID(r)
+	return vid != "" && viewerSentCookie(r) && row.ViewerID.Valid &&
+		row.ViewerID.String != "" && row.ViewerID.String == vid
+}
+
 // handleListMine serves /api/mine: pastes created from this browser (#37).
 func (a *apiServer) handleListMine(w http.ResponseWriter, r *http.Request) {
 	vid := currentViewerID(r)