minstrel/internal/server/hygiene_test.go

package server

import (
	"io"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"git.fabledsword.com/bvandeusen/minstrel/internal/auth"
)

func okHandler() http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Body != nil {
			if _, err := io.ReadAll(r.Body); err != nil {
				http.Error(w, "too large", http.StatusRequestEntityTooLarge)
				return
			}
		}
		w.WriteHeader(http.StatusNoContent)
	})
}

func TestLimitRequestBody_RejectsOversizedBody(t *testing.T) {
	h := limitRequestBody(okHandler())

	big := strings.NewReader(strings.Repeat("x", maxRequestBody+1))
	w := httptest.NewRecorder()
	h.ServeHTTP(w, httptest.NewRequest(http.MethodPost, "/api/playlists", big))
	if w.Code != http.StatusRequestEntityTooLarge {
		t.Errorf("oversized body: status = %d, want the handler's read to fail", w.Code)
	}

	small := strings.NewReader(`{"name":"ok"}`)
	w = httptest.NewRecorder()
	h.ServeHTTP(w, httptest.NewRequest(http.MethodPost, "/api/playlists", small))
	if w.Code != http.StatusNoContent {
		t.Errorf("small body: status = %d, want 204", w.Code)
	}
}

// The cases a cross-site form or no-preflight fetch could produce must be
// refused when the session cookie rides along; everything a real client
// sends must pass.
func TestRequireJSONForCookieWrites(t *testing.T) {
	cookie := &http.Cookie{Name: auth.SessionCookieName, Value: "tok"}
	tests := []struct {
		name        string
		method      string
		path        string
		contentType string
		body        string
		withCookie  bool
		want        int
	}{
		{"form post with cookie", http.MethodPost, "/api/me/password", "application/x-www-form-urlencoded", "a=b", true, http.StatusUnsupportedMediaType},
		{"text/plain post with cookie", http.MethodPost, "/api/me/password", "text/plain", `{"a":1}`, true, http.StatusUnsupportedMediaType},
		{"multipart with cookie", http.MethodPut, "/api/me/profile", "multipart/form-data; boundary=x", "--x--", true, http.StatusUnsupportedMediaType},
		{"body without content type", http.MethodPost, "/api/me/profile", "", `{"a":1}`, true, http.StatusUnsupportedMediaType},

		{"json with cookie", http.MethodPost, "/api/me/password", "application/json", `{}`, true, http.StatusNoContent},
		{"json with charset", http.MethodPost, "/api/me/password", "application/json; charset=utf-8", `{}`, true, http.StatusNoContent},
		{"bodiless delete with cookie", http.MethodDelete, "/api/me/sessions/1", "", "", true, http.StatusNoContent},
		{"form post without cookie (bearer client)", http.MethodPost, "/api/me/password", "text/plain", "x", false, http.StatusNoContent},
		{"subsonic post is not /api", http.MethodPost, "/rest/scrobble", "application/x-www-form-urlencoded", "id=1", true, http.StatusNoContent},
		{"GET is never checked", http.MethodGet, "/api/me", "text/plain", "", true, http.StatusNoContent},
	}
	h := requireJSONForCookieWrites(okHandler())
	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			var body io.Reader
			if tc.body != "" {
				body = strings.NewReader(tc.body)
			}
			req := httptest.NewRequest(tc.method, tc.path, body)
			if tc.contentType != "" {
				req.Header.Set("Content-Type", tc.contentType)
			}
			if tc.withCookie {
				req.AddCookie(cookie)
			}
			w := httptest.NewRecorder()
			h.ServeHTTP(w, req)
			if w.Code != tc.want {
				t.Errorf("status = %d, want %d", w.Code, tc.want)
			}
		})
	}
}

func TestSecurityHeaders(t *testing.T) {
	serve := func(hops int, proto string) http.Header {
		h := securityHeaders(func() int { return hops })(okHandler())
		req := httptest.NewRequest(http.MethodGet, "/api/me", nil)
		if proto != "" {
			req.Header.Set("X-Forwarded-Proto", proto)
		}
		w := httptest.NewRecorder()
		h.ServeHTTP(w, req)
		return w.Header()
	}

	base := serve(0, "")
	for key, want := range map[string]string{
		"X-Content-Type-Options": "nosniff",
		"Referrer-Policy":        "strict-origin-when-cross-origin",
		"X-Frame-Options":        "DENY",
	} {
		if got := base.Get(key); got != want {
			t.Errorf("%s = %q, want %q", key, got, want)
		}
	}
	if !strings.Contains(base.Get("Permissions-Policy"), "microphone=()") {
		t.Errorf("Permissions-Policy = %q", base.Get("Permissions-Policy"))
	}

	// HSTS with no trusted proxy, and through one saying https or http.
	if got := serve(0, "https").Get("Strict-Transport-Security"); got != "" {
		t.Errorf("hops 0 + forwarded https: HSTS = %q, want none", got)
	}
	if got := serve(1, "https").Get("Strict-Transport-Security"); got == "" {
		t.Error("hops 1 + forwarded https: want HSTS")
	}
	if got := serve(1, "").Get("Strict-Transport-Security"); got != "" {
		t.Errorf("plain request: HSTS = %q, want none", got)
	}
}