Core Rule Set: gitea's ordinary requests pass by default (closes #198)

The eighth change, internal/waf/gitea.conf, has the fields where gitea
sends a search, a file name or a branch name skip the rules that refused
ordinary gitea requests, on gitea's paths only. Referer skips 944130 too.
A registry's layer reuse skips 932260 on from, the seventh change.

The new setting SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE loads an operator's
own exclusions before the Core Rule Set's rules. A set file that cannot
be read, does not parse or names smallwebwaf's own ids stops the start
in every mode.

A test sends the recorded gitea requests at the defaults, none refused,
and three attacks, all refused.

Model: opus-5-5

README.md

@@ -192,9 +192,9 @@ account, a key, a token or an alert destination stays off until you give one.
 - Any `SWWAF_` setting can be given as a file instead, for secrets and long
   lists: `SWWAF_ADMIN_TOKEN_FILE` names the file that holds `SWWAF_ADMIN_TOKEN`.
   The file's contents are the value, less one newline at the end. Setting both
-  forms stops the start. `SWWAF_LOG_REMOTE_TLS_CA_FILE` already names a file, so
+  forms stops the start. `SWWAF_LOG_REMOTE_TLS_CA_FILE` and
-  it has no `_FILE` form, and no `SWRP_` setting has one, since `rproxy` never
+  `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE` already name a file, so they have no
-  touches disk.
+  `_FILE` form. No `SWRP_` setting has one, since `rproxy` never touches disk.
 - A duration is Go's syntax, with `d` for days: `90s`, `15m`, `24h`, `7d`.
 - A size is a number of bytes with an optional `K`, `M` or `G`, in powers of
   1024: `512K`, `100M`, `5G`.
@@ -272,6 +272,7 @@ Every setting the code reads, with its default:
 | `SWWAF_WAF_DISABLED_RULES`                 | `920340,920420,920440,920640,930130,930140`                                    | Core Rule Set rule ids switched off; a list you give replaces the default, so repeat these six to keep them off.                                                    |
 | `SWWAF_WAF_EXEMPT_PATHS`                   | empty                                                                          | Path prefixes the Core Rule Set does not inspect.                                                                                                                   |
 | `SWWAF_WAF_BODY_LIMIT`                     | `off`                                                                          | How much of a request body the Core Rule Set reads, a size up to `64K`; `off` reads none.                                                                           |
+| `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE`      | unset                                                                          | A file of Core Rule Set exclusions, as Coraza directives, that switch rules off for some fields or paths only.                                                      |
 | `SWWAF_BLOCKLIST_URLS`                     | empty                                                                          | Blocklists to fetch, text files of addresses and netblocks one to a line, such as `https://www.spamhaus.org/drop/drop.txt`.                                         |
 | `SWWAF_BLOCKLIST_REFRESH`                  | `24h`                                                                          | How long after a list was last tried it is fetched again, `1h` or more.                                                                                             |
 | `SWWAF_BLOCKLIST_ACTION`                   | `deny`                                                                         | What a client on a blocklist gets: `deny`, `limit:<percent>` of every limit, or `log`.                                                                              |
@@ -636,10 +637,13 @@ and the status for a size or time limit, such as `413` for a body too large.
   headers of every request, and no body unless `SWWAF_WAF_BODY_LIMIT` is set. In
   front of a code forge, bodies carry what people write and publish, which the
   rules take for attacks.
-- `smallwebwaf` changes the Core Rule Set in six ways so that it lets ordinary
+- `smallwebwaf` changes the Core Rule Set in eight ways so that it lets ordinary
   requests to a code forge through, such as git over HTTP and sign-in through
-  Git Credential Manager. No setting undoes them; "Attack detection" in
+  Git Credential Manager. On gitea's own paths, its searches, file names and
-  [`SPEC.md`](SPEC.md) lists them.
+  branch names get through too. No setting undoes the changes; "Attack
+  detection" in [`SPEC.md`](SPEC.md) lists them.
+- `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE` switches single rules off for an app's
+  own fields or paths.
 - Rule files are plain text, one rule to a line, edited by hand and read again
   while `servewaf` runs. The image ships one file of probes no real visitor
   sends (see [`docs/rules.md`](docs/rules.md)).

SPEC.md

@@ -36,7 +36,8 @@ to them.
     - the state files;
     - a lookup database;
     - a `SWWAF_` setting given as a file;
-    - the file `SWWAF_LOG_REMOTE_TLS_CA_FILE` names.
+    - the file `SWWAF_LOG_REMOTE_TLS_CA_FILE` names;
+    - the file `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE` names.
 
 ## Non-goals
 
@@ -81,7 +82,7 @@ to them.
       of bans is full.
     - `internal/rules`: reads the rule files at start and again when they
       change, and tells which rules a request matches.
-    - `internal/waf`: the Core Rule Set, with the six changes listed under
+    - `internal/waf`: the Core Rule Set, with the eight changes listed under
       "Attack detection", as Coraza directives.
     - `internal/lookup`: looks clients up through GeoJS or in the lookup
       database.
@@ -325,9 +326,10 @@ Conventions:
   lists: `SWWAF_ADMIN_TOKEN_FILE` names the file that holds `SWWAF_ADMIN_TOKEN`.
   The file's contents are the value, less one newline at the end, and are
   checked as the value itself would be. Setting both forms stops the start, and
-  so does naming a file that cannot be read. `SWWAF_LOG_REMOTE_TLS_CA_FILE`
+  so does naming a file that cannot be read. `SWWAF_LOG_REMOTE_TLS_CA_FILE` and
-  already holds a file name, so it has no `_FILE` form. No `SWRP_` setting has
+  `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE` already hold a file name, so they have
-  one, since `rproxy` never touches disk.
+  no `_FILE` form. No `SWRP_` setting has one, since `rproxy` never touches
+  disk.
 - Settings, files included, are read once at start. Changing one means
   restarting the container. The files `servewaf` watches while it runs are its
   state files, its rule files and the lookup database.
@@ -583,6 +585,24 @@ sends it.
     probes these rules caught (see "Rule files"). A list you give replaces the
     default, so name these six ids in it to keep them off.
 
+- `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE` names a file of exclusions, written as
+  Coraza directives. An exclusion switches one rule off for some fields or paths
+  only, where `SWWAF_WAF_DISABLED_RULES` switches it off everywhere. The file
+  holds an app's own exclusions; the eighth change below holds gitea's.
+    - `servewaf` loads the file after `smallwebwaf`'s own setup rules and before
+      the Core Rule Set's rules. The Core Rule Set puts its own file of
+      exclusions that run before the rules in the same place.
+    - So the file holds only `SecAction` and `SecRule` lines that exclude with
+      `ctl:ruleRemoveTargetById` or `ctl:ruleRemoveById`. These run with each
+      request, before the rules they exclude, those of phase 1 included.
+    - A rule that `SWWAF_WAF_DISABLED_RULES` switches off and the file names is
+      simply off.
+    - The start stops on a file that cannot be read or does not parse, whatever
+      `SWWAF_WAF_MODE` is.
+    - It stops too on a file that names a number from 900000 to 900999, the ids
+      of `smallwebwaf`'s own rules, alone or in a range. Comment lines are not
+      checked.
+
 - `SWWAF_WAF_BODY_LIMIT` switches body inspection on, up to that size. It takes
   at most `64K`, since `servewaf` gets no more of a body than that (see "The
   answer"). Form data and multipart bodies are read up to the size. JSON and XML
@@ -612,7 +632,7 @@ sends it.
     scanner from an ordinary client. In front of gitea, registry and git clients
     get `404` and `401` by design, hundreds of times a minute.
 
-`smallwebwaf` changes the Core Rule Set 4.25.0 in six ways, since in front of
+`smallwebwaf` changes the Core Rule Set 4.25.0 in eight ways, since in front of
 gitea it would otherwise refuse ordinary requests. The changes hold in front of
 every app, and no setting undoes them:
 
@@ -644,9 +664,10 @@ every app, and no setting undoes them:
     or `docker-build`. In these parameters, what only these three rules would
     catch reaches the app, such as the command `|cat /etc/passwd`. Path
     traversal, SQL and script injection, and PHP, Java and Node.js code are
-    still refused there. Every other parameter keeps all three rules. An app
+    still refused there. Other parameters keep all three rules, except on the
-    that uses one of these parameters as a file on the server, or passes it to a
+    gitea paths the eighth change names. An app that uses one of these
-    shell, must check the value itself. A rule file can refuse it instead.
+    parameters as a file on the server, or passes it to a shell, must check the
+    value itself. A rule file can refuse it instead.
 
 5. Two cookies are left out, and `Referer` keeps fewer rules:
     - The Core Rule Set reads the request without the `gitea_flash` and
@@ -660,15 +681,47 @@ every app, and no setting undoes them:
       only to its own pages. Every other cookie is read in full. An app that
       reads a cookie of either name must check it itself.
     - `Referer` is not checked for a Unix command given without arguments
-      (932340) or for Java starting a process (944110). `Referer` names the page
+      (932340), for Java starting a process (944110) or for a Java class name
-      a request comes from, on everything that page loads and on every link
+      (944130). `Referer` names the page a request comes from, on everything
-      followed from it. The Core Rule Set takes some page addresses for attacks,
+      that page loads and on every link followed from it. The Core Rule Set
-      such as a search for `env`, or OpenJDK's `Runtime.java`, whose path holds
+      takes some page addresses for attacks, such as a search for `env`,
-      both `runtime` and `java.`. All of those requests would be refused.
+      OpenJDK's `Runtime.java`, whose path holds both `runtime` and `java.`, or
-      `Referer` keeps the other rules. An app that passes `Referer` to a shell
+      a file named `java.lang.String.md`. All of those requests would be
-      must check it itself.
+      refused. `Referer` keeps the other rules, except after a gitea search (the
+      eighth change). An app that passes `Referer` to a shell must check it
+      itself.
 6. Responses are not inspected. A raw file from a repository, such as a shell
    script, looks to the response rules like source code leaking from the server.
+7. The `from` parameter of a container registry's upload path,
+   `/v2/<image>/blobs/uploads/`, is not checked for command names (932260). When
+   a push reuses a layer, `from` names the image the layer comes from. An image
+   such as `owner/python3-app` would have that push refused.
+8. On gitea's own paths, the fields where gitea sends a search, a file name or a
+   branch name skip the rules that refused ordinary gitea requests there.
+   `internal/waf/gitea.conf` lists each rule and the request it refused. The
+   fields are:
+    - `q` on gitea's search pages, for code, issues, pull requests, commits,
+      repositories, branches, tags, packages and users. A code search holds
+      code, such as `<script>`, `SELECT * FROM users WHERE` or `../`.
+    - `Referer` of a page opened from such a search, for script and SQL
+      injection and Java code (941110, 941120, 941160, 942100, 944100).
+    - The path of a file's page, raw file, download, blame, history, edit and
+      delete pages, and of the API's call for its contents. Names such as
+      `notes.txt~`, `process.env.d.ts` and `java.lang.String.md` were refused.
+    - A file name in a query parameter: `file` of a commit graph, `path` of the
+      API's list of commits, `body` of the API's call for several files,
+      `template` of a new issue, `redirect_to` of the sign-in page, and `name`
+      of an attachment uploaded through the API.
+    - A branch or tag name in a query parameter, for command names (932260).
+      gitea sends one to delete or restore a branch, to start a release from a
+      tag, to edit a branch protection rule, and to list a directory's last
+      commits.
+    - The `Content-Range` header of an artifact upload from
+      `actions/upload-artifact@v3` (920450).
+
+    Elsewhere these fields keep every rule. The paths are those of gitea at the
+    site root. An app other than gitea that serves one of them must check these
+    fields itself.
 
 The parameter and cookie names in these changes are matched without regard to
 case, as Coraza matches them.

docs/settings.md

@@ -192,6 +192,13 @@ chooses between the two (see "The image's command" below).
   the Core Rule Set reads, a size of at most `64K`. A question carries no more
   of a body than 64 KiB, and the Core Rule Set reads at most 64 KiB less one
   byte of it, whatever the value (see "The answer" in [`SPEC.md`](../SPEC.md)).
+- `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE` (default unset): a file of Core Rule Set
+  exclusions, written as Coraza directives. It is loaded before the Core Rule
+  Set's rules, so it holds only `SecAction` and `SecRule` lines that exclude
+  with `ctl:ruleRemoveTargetById` or `ctl:ruleRemoveById`. A file that cannot be
+  read or does not parse stops the start, whatever `SWWAF_WAF_MODE` is. So does
+  a file that names a number from 900000 to 900999 outside a comment, alone or
+  in a range. It has no `_FILE` form.
 - `SWWAF_ERROR_BURST_THRESHOLD` (default `30`): the most refusals of one client
   in a minute (see "Attack detection" in `SPEC.md`). A count or `off`.
 

internal/config/config.go

@@ -221,12 +221,15 @@ type Config struct {
 	// WAFExemptPaths the path prefixes it does not inspect
 	// (SWWAF_WAF_EXEMPT_PATHS), and WAFBodyLimit the most of a request body
 	// it reads (SWWAF_WAF_BODY_LIMIT), 0 while it is off and it reads none.
+	// CoreRuleSetExclusionsFile is the path of the file of its exclusions
+	// (SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE), "" while there is none.
 	WAFMode                   string
 	WAFParanoiaLevel          int
 	WAFAnomalyThreshold       int
 	WAFDisabledRules          []int
 	WAFExemptPaths            []string
 	WAFBodyLimit              int64
+	CoreRuleSetExclusionsFile string
 	// TrapPaths are the paths a request for which is a clear sign of
 	// attack (SWWAF_TRAP_PATHS), each starting with / and without a ?.
 	TrapPaths []string
@@ -525,6 +528,8 @@ func FromEnvironment(lookupEnv func(string) (string, bool)) (*Config, error) {
 			"920340,920420,920440,920640,930130,930140"),
 		WAFExemptPaths: env.pathPrefixes("SWWAF_WAF_EXEMPT_PATHS", ""),
 		WAFBodyLimit:   env.wafBodyLimit("SWWAF_WAF_BODY_LIMIT", off),
+		CoreRuleSetExclusionsFile: env.filePath(
+			"SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE"),
 		TrapPaths:            env.trapPaths("SWWAF_TRAP_PATHS"),
 		ErrorBurstThreshold:  env.count("SWWAF_ERROR_BURST_THRESHOLD", "30"),
 		LogRemoteURL:         env.logRemoteURL("SWWAF_LOG_REMOTE_URL"),
@@ -1189,6 +1194,16 @@ func (e *environment) logRemoteURL(name string) *url.URL {
 	return remote
 }
 
+// filePath reads a setting that is the path of a file, "" while it is
+// unset. Its value names a file already, so, unlike the other settings,
+// it has no _FILE form. Whoever uses the file reads it.
+func (e *environment) filePath(name string) string {
+	path, _ := e.lookupEnv(name)
+	e.settings = append(e.settings, slog.String(name, path))
+
+	return path
+}
+
 // certificates reads a setting that is the path of a file of PEM
 // certificates. Unset or empty, it is nil. Its value names a file
 // already, so, unlike the other settings, it has no _FILE form.

internal/config/config_test.go

@@ -87,6 +87,7 @@ const (
 	wafDisabledRules     = "SWWAF_WAF_DISABLED_RULES"
 	wafExemptPaths       = "SWWAF_WAF_EXEMPT_PATHS"
 	wafBodyLimit         = "SWWAF_WAF_BODY_LIMIT"
+	exclusionsFile       = "SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE"
 	trapPaths            = "SWWAF_TRAP_PATHS"
 	errorBurstThreshold  = "SWWAF_ERROR_BURST_THRESHOLD"
 	logRemoteURL         = "SWWAF_LOG_REMOTE_URL"
@@ -539,13 +540,14 @@ func TestCoreRuleSetSettings(t *testing.T) {
 			environment{
 				wafMode: config.WAFModeDetect, wafParanoiaLevel: "4", wafAnomalyThreshold: "10",
 				wafDisabledRules: "942100, 920350", wafExemptPaths: "/api/, /static/",
-				wafBodyLimit: "32K",
+				wafBodyLimit: "32K", exclusionsFile: "/etc/smallwebwaf/crs-exclusions.conf",
 			},
 			config.Config{
 				WAFMode: config.WAFModeDetect, WAFParanoiaLevel: 4, WAFAnomalyThreshold: 10,
 				WAFDisabledRules:          []int{942100, 920350},
 				WAFExemptPaths:            []string{"/api/", "/static/"},
 				WAFBodyLimit:              32 << 10,
+				CoreRuleSetExclusionsFile: "/etc/smallwebwaf/crs-exclusions.conf",
 			},
 		},
 		{
@@ -566,6 +568,7 @@ func TestCoreRuleSetSettings(t *testing.T) {
 			WAFAnomalyThreshold: cfg.WAFAnomalyThreshold,
 			WAFDisabledRules:    cfg.WAFDisabledRules, WAFExemptPaths: cfg.WAFExemptPaths,
 			WAFBodyLimit:              cfg.WAFBodyLimit,
+			CoreRuleSetExclusionsFile: cfg.CoreRuleSetExclusionsFile,
 		}
 		if !reflect.DeepEqual(got, tc.want) {
 			t.Errorf("%v gave\n%+v\nwant\n%+v", tc.env, got, tc.want)
@@ -2327,6 +2330,7 @@ func TestLogsEachSettingWithItsValue(t *testing.T) {
 		wafDisabledRules:     defaultWAFDisabledRules,
 		wafExemptPaths:       "",
 		wafBodyLimit:         off,
+		exclusionsFile:       "",
 		trapPaths:            "",
 		errorBurstThreshold:  "30",
 		logRemoteURL:         "",

internal/servewaf/proxy.go

@@ -4,6 +4,7 @@
 package servewaf
 
 import (
+	"fmt"
 	"io"
 	"log/slog"
 	"net/http"
@@ -60,6 +61,9 @@ type Params struct {
 	// LookupFile is the lookup database they are looked up in while
 	// SWWAF_LOOKUP_SOURCE is file, and nil otherwise.
 	LookupFile *lookup.File
+	// CoreRuleSet is what NewCoreRuleSet returns: what inspects requests
+	// while SWWAF_WAF_MODE is not off, and nil while it is.
+	CoreRuleSet *waf.CoreRuleSet
 	// Now tells the time by which requests are counted for the rate
 	// limits, bans are made and run out, and GeoJS's answers are kept,
 	// normally time.Now in UTC, the time the state files give.
@@ -144,7 +148,7 @@ func newHandler(params Params) *handler {
 		dnsbl:       dnsbl,
 		abuseIPDB:   abuseIPDB,
 		rules:       params.Rules,
-		coreRuleSet: newCoreRuleSet(params.Config),
+		coreRuleSet: params.CoreRuleSet,
 		alerts:      params.Alerts,
 	}
 	h.geojs = lookup.New(lookup.Params{
@@ -202,29 +206,35 @@ func newReputation(
 	return lists, dnsbl, abuseIPDB
 }
 
-// newCoreRuleSet returns the Core Rule Set at SWWAF_WAF_PARANOIA_LEVEL,
+// NewCoreRuleSet returns the Core Rule Set at SWWAF_WAF_PARANOIA_LEVEL,
 // without the rules SWWAF_WAF_DISABLED_RULES switches off, reading bodies
-// up to SWWAF_WAF_BODY_LIMIT, or nil while SWWAF_WAF_MODE is off. It reads at
+// up to SWWAF_WAF_BODY_LIMIT, with the exclusions in
-// most QuestionBodyMaxBytes less one byte: a question's body of
+// SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE, or nil while SWWAF_WAF_MODE is off. It
+// reads at most QuestionBodyMaxBytes less one byte: a question's body of
 // QuestionBodyMaxBytes may be cut short, and the Core Rule Set does not read a
-// JSON or XML body over its limit.
+// JSON or XML body over its limit. An exclusions file that cannot be read, does
-func newCoreRuleSet(cfg *config.Config) *waf.CoreRuleSet {
+// not parse or names an id of smallwebwaf's own rules is an error in every
-	if cfg.WAFMode == config.WAFModeOff {
+// mode. While the mode is off, a set file is loaded with the Core Rule Set only
-		return nil
+// to check it.
+func NewCoreRuleSet(cfg *config.Config) (*waf.CoreRuleSet, error) {
+	if cfg.WAFMode == config.WAFModeOff && cfg.CoreRuleSetExclusionsFile == "" {
+		return nil, nil //nolint:nilnil // off is no Core Rule Set, and no error
 	}
 
 	coreRuleSet, err := waf.New(waf.Params{
 		ParanoiaLevel: cfg.WAFParanoiaLevel, DisabledRules: cfg.WAFDisabledRules,
 		BodyLimit:      min(cfg.WAFBodyLimit, QuestionBodyMaxBytes-1),
+		ExclusionsFile: cfg.CoreRuleSetExclusionsFile,
 	})
 	if err != nil {
-		// The Core Rule Set is built in, and the settings cannot break it:
+		return nil, fmt.Errorf("SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE: %w", err)
-		// the paranoia level is from 1 to 4, and the id of no rule switches
-		// nothing off.
-		panic(err)
 	}
 
-	return coreRuleSet
+	if cfg.WAFMode == config.WAFModeOff {
+		return nil, nil //nolint:nilnil // off is no Core Rule Set, and no error
+	}
+
+	return coreRuleSet, nil
 }
 
 // handler is servewaf's handler. It holds what every request shares; what

internal/servewaf/proxy_test.go

@@ -463,6 +463,11 @@ func newServeWAFWith(
 		}
 	}
 
+	coreRuleSet, err := servewaf.NewCoreRuleSet(cfg)
+	if err != nil {
+		t.Fatalf("Core Rule Set: %v", err)
+	}
+
 	server := build(servewaf.Params{
 		Config:       cfg,
 		RequestLog:   out,
@@ -470,6 +475,7 @@ func newServeWAFWith(
 		GeoJSURL:     geojsURL,
 		AbuseIPDBURL: abuseIPDBURL,
 		LookupFile:   lookupFile,
+		CoreRuleSet:  coreRuleSet,
 		Now:          now,
 		Rules:        ruleFiles,
 		Alerts:       alertQueue,

internal/smallwebwaf/smallwebwaf.go

@@ -29,6 +29,7 @@ import (
 	"sneak.berlin/go/smallwebwaf/internal/rules"
 	"sneak.berlin/go/smallwebwaf/internal/servewaf"
 	"sneak.berlin/go/smallwebwaf/internal/state"
+	"sneak.berlin/go/smallwebwaf/internal/waf"
 )
 
 // shutdownTimeout is how long requests in progress may take to finish
@@ -150,7 +151,14 @@ func RunServeWAF(ctx context.Context, params Params) int {
 		return 1
 	}
 
-	server, err := newServer(cfg, stdout, processLog, now, ruleFiles, alertQueue)
+	crs, err := servewaf.NewCoreRuleSet(cfg)
+	if err != nil {
+		processLog.Error("cannot use the Core Rule Set", "error", err.Error())
+
+		return 1
+	}
+
+	server, err := newServer(cfg, stdout, processLog, now, ruleFiles, alertQueue, crs)
 	if err != nil {
 		processLog.Error("cannot use the lookup database", "error", err.Error())
 
@@ -170,8 +178,7 @@ func RunServeWAF(ctx context.Context, params Params) int {
 
 	listener, err := (&net.ListenConfig{}).Listen(ctx, "tcp", cfg.ListenAddr)
 	if err != nil {
-		processLog.Error("cannot listen on SWWAF_LISTEN_ADDR",
+		processLog.Error("cannot listen on SWWAF_LISTEN_ADDR", "error", err.Error())
-			"error", err.Error())
 
 		return 1
 	}
@@ -190,6 +197,7 @@ func RunServeWAF(ctx context.Context, params Params) int {
 func newServer(
 	cfg *config.Config, stdout io.Writer, processLog *slog.Logger,
 	now func() time.Time, ruleFiles *rules.Files, alertQueue *alerts.Queue,
+	crs *waf.CoreRuleSet,
 ) (*servewaf.Server, error) {
 	var lookupFile *lookup.File
 
@@ -214,6 +222,7 @@ func newServer(
 		GeoJSURL:     lookup.URL,
 		AbuseIPDBURL: reputation.AbuseIPDBURL,
 		LookupFile:   lookupFile,
+		CoreRuleSet:  crs,
 		Now:          now,
 		Rules:        ruleFiles,
 		Alerts:       alertQueue,

internal/smallwebwaf/smallwebwaf_test.go

@@ -19,6 +19,7 @@ import (
 	"testing"
 	"time"
 
+	"sneak.berlin/go/smallwebwaf/internal/config"
 	"sneak.berlin/go/smallwebwaf/internal/lookup/lookuptest"
 	"sneak.berlin/go/smallwebwaf/internal/servewaf"
 	"sneak.berlin/go/smallwebwaf/internal/smallwebwaf"
@@ -551,6 +552,56 @@ func TestRulesDirThatDoesNotExistStopsTheStart(t *testing.T) {
 		": no such file or directory")
 }
 
+func TestCoreRuleSetExclusionsFileThatCannotBeReadStopsTheStart(t *testing.T) {
+	t.Parallel()
+
+	path := filepath.Join(t.TempDir(), "crs-exclusions.conf")
+	out := &output{}
+
+	status := run(t.Context(), map[string]string{
+		listenAddr: localhost + ":0", stateDir: t.TempDir(), rulesDir: t.TempDir(),
+		"SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE": path,
+	}, out)
+	if status != 1 {
+		t.Fatalf("exit status %d, want 1", status)
+	}
+
+	line := out.line(t, "msg", "cannot use the Core Rule Set")
+	want := "SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE: read the exclusions file: open " +
+		path + ": no such file or directory"
+
+	if line["error"] != want {
+		t.Errorf("start refused with %v, want the error %q", line, want)
+	}
+}
+
+func TestCoreRuleSetExclusionsFileThatCannotBeUsedStopsTheStartWhileTheCoreRuleSetIsOff(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	broken := filepath.Join(t.TempDir(), "broken.conf")
+
+	err := os.WriteFile(broken, []byte("SecNoSuchDirective On\n"), 0o600)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	for _, path := range []string{filepath.Join(t.TempDir(), "missing.conf"), broken} {
+		out := &output{}
+
+		status := run(t.Context(), map[string]string{
+			listenAddr: localhost + ":0", stateDir: t.TempDir(), rulesDir: t.TempDir(),
+			"SWWAF_WAF_MODE": config.WAFModeOff, "SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE": path,
+		}, out)
+		if status != 1 {
+			t.Fatalf("%s: exit status %d, want 1", path, status)
+		}
+
+		out.line(t, "msg", "cannot use the Core Rule Set")
+	}
+}
+
 func TestLookupDatabaseReplacedWhileRunningTakesEffect(t *testing.T) {
 	t.Parallel()
 

internal/waf/gitea.conf

@@ -0,0 +1,236 @@
+# The eighth change: on gitea's own paths, the fields in which gitea sends a
+# search, a file name or a branch name skip the rules that refused ordinary
+# gitea requests there. Each exclusion runs with the request, before the rules
+# it switches off, those of phase 1 included, so this file is loaded before the
+# Core Rule Set's rules. Each comment names a request the rule refused.
+
+# gitea's searches send the text searched for in q: searches of code, of issues
+# and pull requests, of commits, and of repositories, branches, tags, packages
+# and users. q skips these rules there:
+#   930110: ../
+#   930120: .gitignore
+#   931100: http://127.0.0.1:8080
+#   932120: Invoke-WebRequest
+#   932130: $(pwd)
+#   932140: if (a == b) {
+#   932160: /bin/sh
+#   932235: `make check`
+#   932250: ls -la
+#   932260: python3
+#   932380: `whoami`
+#   933100: <?php echo
+#   933130: $_GET[
+#   933135: ${VAR}
+#   934100: process.env
+#   934110: http://127.0.0.1:8080
+#   934130: __proto__
+#   941100: <script>
+#   941110: <script>
+#   941160: <img src=
+#   941180: document.cookie
+#   941390: fetch(
+#   942100: SELECT * FROM users WHERE
+#   942140: information_schema
+#   942190: union select
+#   942230: if (a == b) {
+#   944100: java.lang.Runtime
+#   944110: java.lang.Runtime
+#   944130: java.lang.Runtime
+SecRule REQUEST_FILENAME "@rx ^/(?:explore/(?:repos|code)|issues(?:/search)?|pulls|\
+    user/search_candidates|[^/]+/-/(?:code|packages)|\
+    [^/]+/[^/]+/(?:search|issues(?:/search)?|pulls|branches|tags|\
+    commits/(?:branch|tag|commit)/.+/search)|\
+    api/v1/repos/(?:search|issues/search|[^/]+/[^/]+/issues))$" \
+    "id:900600,phase:1,pass,nolog,\
+    ctl:ruleRemoveTargetById=930110;ARGS:q,\
+    ctl:ruleRemoveTargetById=930120;ARGS:q,\
+    ctl:ruleRemoveTargetById=931100;ARGS:q,\
+    ctl:ruleRemoveTargetById=932120;ARGS:q,\
+    ctl:ruleRemoveTargetById=932130;ARGS:q,\
+    ctl:ruleRemoveTargetById=932140;ARGS:q,\
+    ctl:ruleRemoveTargetById=932160;ARGS:q,\
+    ctl:ruleRemoveTargetById=932235;ARGS:q,\
+    ctl:ruleRemoveTargetById=932250;ARGS:q,\
+    ctl:ruleRemoveTargetById=932260;ARGS:q,\
+    ctl:ruleRemoveTargetById=932380;ARGS:q,\
+    ctl:ruleRemoveTargetById=933100;ARGS:q,\
+    ctl:ruleRemoveTargetById=933130;ARGS:q,\
+    ctl:ruleRemoveTargetById=933135;ARGS:q,\
+    ctl:ruleRemoveTargetById=934100;ARGS:q,\
+    ctl:ruleRemoveTargetById=934110;ARGS:q,\
+    ctl:ruleRemoveTargetById=934130;ARGS:q,\
+    ctl:ruleRemoveTargetById=941100;ARGS:q,\
+    ctl:ruleRemoveTargetById=941110;ARGS:q,\
+    ctl:ruleRemoveTargetById=941160;ARGS:q,\
+    ctl:ruleRemoveTargetById=941180;ARGS:q,\
+    ctl:ruleRemoveTargetById=941390;ARGS:q,\
+    ctl:ruleRemoveTargetById=942100;ARGS:q,\
+    ctl:ruleRemoveTargetById=942140;ARGS:q,\
+    ctl:ruleRemoveTargetById=942190;ARGS:q,\
+    ctl:ruleRemoveTargetById=942230;ARGS:q,\
+    ctl:ruleRemoveTargetById=944100;ARGS:q,\
+    ctl:ruleRemoveTargetById=944110;ARGS:q,\
+    ctl:ruleRemoveTargetById=944130;ARGS:q"
+
+# A page opened from the results of one of those searches has the search's
+# address in Referer, which skips these rules then:
+#   941110: <script>
+#   941120: onClick={
+#   941160: <img src=
+#   942100: LIKE '%foo%'
+#   944100: java.lang.Runtime
+SecRule REQUEST_HEADERS:Referer "@rx ^https?://[^/]+/(?:explore/(?:repos|code)|\
+    issues(?:/search)?|pulls|user/search_candidates|[^/]+/-/(?:code|packages)|\
+    [^/]+/[^/]+/(?:search|issues(?:/search)?|pulls|branches|tags|\
+    commits/(?:branch|tag|commit)/.+/search)|\
+    api/v1/repos/(?:search|issues/search|[^/]+/[^/]+/issues))\?" \
+    "id:900601,phase:1,pass,nolog,\
+    ctl:ruleRemoveTargetById=941110;REQUEST_HEADERS:Referer,\
+    ctl:ruleRemoveTargetById=941120;REQUEST_HEADERS:Referer,\
+    ctl:ruleRemoveTargetById=941160;REQUEST_HEADERS:Referer,\
+    ctl:ruleRemoveTargetById=942100;REQUEST_HEADERS:Referer,\
+    ctl:ruleRemoveTargetById=944100;REQUEST_HEADERS:Referer"
+
+# A file's page, raw file and download, its blame, history, edit and delete
+# pages, and the API's call for its contents name the file in the path, which
+# skips these rules there:
+#   920500: notes.txt~
+#   934100: process.env.d.ts
+#   941130: docs/a b.xhtml
+#   944130: java.lang.String.md
+SecRule REQUEST_FILENAME \
+    "@rx ^/(?:api/v1/repos/)?[^/]+/[^/]+/(?:src|raw|media|blame|commits|_edit|_delete|contents)/" \
+    "id:900610,phase:1,pass,nolog,\
+    ctl:ruleRemoveTargetById=920500;REQUEST_FILENAME,\
+    ctl:ruleRemoveTargetById=934100;REQUEST_FILENAME,\
+    ctl:ruleRemoveTargetById=941130;REQUEST_FILENAME,\
+    ctl:ruleRemoveTargetById=944130;REQUEST_FILENAME"
+
+# The requests below name a file in a query parameter. These rules refused
+# them for the file named:
+#   930120: .gitignore
+#   932120: install-script.sh
+#   932130: [draft].md
+#   932160: bin/docker-entrypoint
+#   932260: docker-compose.yml
+#   934100: process.env.d.ts
+#   934130: __proto__.json
+#   941130: index.xhtml
+#   941180: document.write.js
+#   942140: information_schema.sql
+#   944110: java/lang/Runtime.java
+#   944130: java.lang.String.md
+# Each request skips the rules that refused it. The fourth change already has
+# path and redirect_to skip 930120, 932160 and 932260 on every path.
+
+# A file's commit graph, in file.
+SecRule REQUEST_FILENAME "@rx ^/[^/]+/[^/]+/graph$" \
+    "id:900620,phase:1,pass,nolog,\
+    ctl:ruleRemoveTargetById=930120;ARGS:file,\
+    ctl:ruleRemoveTargetById=932120;ARGS:file,\
+    ctl:ruleRemoveTargetById=932160;ARGS:file,\
+    ctl:ruleRemoveTargetById=932260;ARGS:file,\
+    ctl:ruleRemoveTargetById=934100;ARGS:file,\
+    ctl:ruleRemoveTargetById=934130;ARGS:file,\
+    ctl:ruleRemoveTargetById=941130;ARGS:file,\
+    ctl:ruleRemoveTargetById=941180;ARGS:file,\
+    ctl:ruleRemoveTargetById=942140;ARGS:file,\
+    ctl:ruleRemoveTargetById=944110;ARGS:file,\
+    ctl:ruleRemoveTargetById=944130;ARGS:file"
+
+# The API's list of a file's commits, in path.
+SecRule REQUEST_FILENAME "@rx ^/api/v1/repos/[^/]+/[^/]+/commits$" \
+    "id:900621,phase:1,pass,nolog,\
+    ctl:ruleRemoveTargetById=932120;ARGS:path,\
+    ctl:ruleRemoveTargetById=934100;ARGS:path,\
+    ctl:ruleRemoveTargetById=934130;ARGS:path,\
+    ctl:ruleRemoveTargetById=941130;ARGS:path,\
+    ctl:ruleRemoveTargetById=941180;ARGS:path,\
+    ctl:ruleRemoveTargetById=942140;ARGS:path,\
+    ctl:ruleRemoveTargetById=944110;ARGS:path,\
+    ctl:ruleRemoveTargetById=944130;ARGS:path"
+
+# The API's call for the contents of several files, in body, as JSON.
+SecRule REQUEST_FILENAME "@rx ^/api/v1/repos/[^/]+/[^/]+/file-contents$" \
+    "id:900622,phase:1,pass,nolog,\
+    ctl:ruleRemoveTargetById=930120;ARGS:body,\
+    ctl:ruleRemoveTargetById=932120;ARGS:body,\
+    ctl:ruleRemoveTargetById=932160;ARGS:body,\
+    ctl:ruleRemoveTargetById=934100;ARGS:body,\
+    ctl:ruleRemoveTargetById=934130;ARGS:body,\
+    ctl:ruleRemoveTargetById=941130;ARGS:body,\
+    ctl:ruleRemoveTargetById=941180;ARGS:body,\
+    ctl:ruleRemoveTargetById=942140;ARGS:body,\
+    ctl:ruleRemoveTargetById=944110;ARGS:body,\
+    ctl:ruleRemoveTargetById=944130;ARGS:body"
+
+# An issue opened from a template, in template.
+SecRule REQUEST_FILENAME "@rx ^/[^/]+/[^/]+/issues/new$" \
+    "id:900623,phase:1,pass,nolog,\
+    ctl:ruleRemoveTargetById=930120;ARGS:template,\
+    ctl:ruleRemoveTargetById=932120;ARGS:template,\
+    ctl:ruleRemoveTargetById=932130;ARGS:template,\
+    ctl:ruleRemoveTargetById=932160;ARGS:template,\
+    ctl:ruleRemoveTargetById=932260;ARGS:template,\
+    ctl:ruleRemoveTargetById=934100;ARGS:template,\
+    ctl:ruleRemoveTargetById=934130;ARGS:template,\
+    ctl:ruleRemoveTargetById=941130;ARGS:template,\
+    ctl:ruleRemoveTargetById=941180;ARGS:template,\
+    ctl:ruleRemoveTargetById=942140;ARGS:template,\
+    ctl:ruleRemoveTargetById=944110;ARGS:template,\
+    ctl:ruleRemoveTargetById=944130;ARGS:template"
+
+# The sign-in page on the way to a file's edit page, in redirect_to.
+SecRule REQUEST_FILENAME "@rx ^/user/login$" \
+    "id:900624,phase:1,pass,nolog,\
+    ctl:ruleRemoveTargetById=932120;ARGS:redirect_to,\
+    ctl:ruleRemoveTargetById=932130;ARGS:redirect_to,\
+    ctl:ruleRemoveTargetById=934100;ARGS:redirect_to,\
+    ctl:ruleRemoveTargetById=934130;ARGS:redirect_to,\
+    ctl:ruleRemoveTargetById=941130;ARGS:redirect_to,\
+    ctl:ruleRemoveTargetById=941180;ARGS:redirect_to,\
+    ctl:ruleRemoveTargetById=942140;ARGS:redirect_to,\
+    ctl:ruleRemoveTargetById=944110;ARGS:redirect_to,\
+    ctl:ruleRemoveTargetById=944130;ARGS:redirect_to"
+
+# An attachment uploaded through the API to a release, an issue or a comment,
+# in name.
+SecRule REQUEST_FILENAME \
+    "@rx ^/api/v1/repos/[^/]+/[^/]+/(?:releases|issues|issues/comments)/[0-9]+/assets$" \
+    "id:900625,phase:1,pass,nolog,\
+    ctl:ruleRemoveTargetById=930120;ARGS:name,\
+    ctl:ruleRemoveTargetById=932120;ARGS:name,\
+    ctl:ruleRemoveTargetById=932260;ARGS:name,\
+    ctl:ruleRemoveTargetById=934100;ARGS:name,\
+    ctl:ruleRemoveTargetById=934130;ARGS:name,\
+    ctl:ruleRemoveTargetById=941130;ARGS:name,\
+    ctl:ruleRemoveTargetById=941180;ARGS:name,\
+    ctl:ruleRemoveTargetById=942140;ARGS:name,\
+    ctl:ruleRemoveTargetById=944130;ARGS:name"
+
+# The requests below name a branch or tag in a query parameter, which skips
+# the list of command names (932260) there. It refused names such as
+# docker-build, python3-migration and feat/docker-support.
+
+# Deleting or restoring a branch, in name.
+SecRule REQUEST_FILENAME "@rx ^/[^/]+/[^/]+/branches/(?:delete|restore)$" \
+    "id:900630,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932260;ARGS:name"
+
+# A release started from a tag, in tag.
+SecRule REQUEST_FILENAME "@rx ^/[^/]+/[^/]+/releases/new$" \
+    "id:900631,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932260;ARGS:tag"
+
+# A branch protection rule opened for editing, in rule_name.
+SecRule REQUEST_FILENAME "@rx ^/[^/]+/[^/]+/settings/branches/edit$" \
+    "id:900632,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932260;ARGS:rule_name"
+
+# A directory listing's last commits, in refSubUrl.
+SecRule REQUEST_FILENAME "@rx ^/[^/]+/[^/]+/lastcommit/" \
+    "id:900633,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932260;ARGS:refSubUrl"
+
+# An artifact upload from actions/upload-artifact@v3 sends the header
+# Content-Range, which the Core Rule Set refused (920450).
+SecRule REQUEST_FILENAME \
+    "@rx ^/api/actions_pipeline/_apis/pipelines/workflows/[0-9]+/artifacts/[^/]+/upload$" \
+    "id:900640,phase:1,pass,nolog,\
+    ctl:ruleRemoveTargetById=920450;REQUEST_HEADERS_NAMES:Content-Range"

internal/waf/testdata/gitea-requests.txt

@@ -0,0 +1,367 @@
+# Ordinary gitea 1.27 requests that the Core Rule Set must let through at the
+# defaults. Each line is a path and query, and may end with one header after a
+# space. The tests of internal/waf inspect each as a GET. The Core Rule Set reads
+# the query and the headers the same way for any method.
+
+# Searches with ordinary words and symbols.
+/owner/repo/search?q=package.json
+/owner/repo/search?q=.gitignore
+/owner/repo/search?q=docker-compose.yml
+/owner/repo/search?q=python3
+/owner/repo/search?q=ssh%20key
+/owner/repo/search?q=feat%2Fdocker-support
+/owner/repo/search?q=ls%20-la
+/owner/repo/search?q=sed%20-i
+/owner/repo/search?q=%2Fbin%2Fsh
+/owner/repo/search?q=%60make%20check%60
+/owner/repo/search?q=%60whoami%60
+/owner/repo/search?q=fetch%28
+/owner/repo/search?q=%24%7BVAR%7D
+/owner/repo/search?q=%24%28pwd%29
+/owner/repo/search?q=process.env
+/owner/repo/search?q=%3Cimg%20src%3D
+/owner/repo/search?q=%3Cscript%3E
+/owner/repo/search?q=SELECT%20%2A%20FROM%20users%20WHERE
+/owner/repo/search?q=union%20select
+/owner/repo/search?q=http%3A%2F%2F127.0.0.1%3A8080
+/owner/repo/search?q=..%2F
+/owner/repo/search?q=%2Fetc%2Fpasswd
+/owner/repo/search?q=eval%28
+/owner/repo/search?q=chmod%20%2Bx
+/owner/repo/search?q=echo%20%24PATH
+/owner/repo/search?q=java.lang.Runtime
+/owner/repo/search?q=document.cookie
+/owner/repo/search?q=alert%281%29
+/owner/repo/search?q=__proto__
+/owner/repo/search?q=C%3A%5CWindows%5CSystem32
+/owner/repo/search?q=Invoke-WebRequest
+/owner/repo/search?q=if%20%28a%20%3D%3D%20b%29%20%7B
+/owner/repo/search?q=sudo%20apt%20install
+/owner/repo/search?q=~%2F.ssh%2Fconfig
+/owner/repo/search?q=.htaccess
+/owner/repo/search?q=%24_GET%5B
+/owner/repo/search?q=%24_POST
+/owner/repo/search?q=%24_SERVER%5B%27REQUEST_URI%27%5D
+/owner/repo/search?q=%3C%3Fphp%20echo
+/owner/repo/search?q=information_schema
+/owner/repo/search?q=LIKE%20%27%25foo%25%27
+/owner/repo/search?q=onClick%3D%7B
+/explore/repos?q=SELECT%20%2A%20FROM%20users%20WHERE
+/explore/repos?q=%3Cimg%20src%3D
+/explore/code?q=SELECT%20%2A%20FROM%20users%20WHERE
+/explore/code?q=%3Cimg%20src%3D
+/owner/-/code?q=SELECT%20%2A%20FROM%20users%20WHERE
+/owner/-/code?q=%3Cimg%20src%3D
+/owner/repo/issues?type=all&state=open&q=SELECT%20%2A%20FROM%20users%20WHERE
+/owner/repo/issues?type=all&state=open&q=%3Cimg%20src%3D
+/owner/repo/issues/search?q=SELECT%20%2A%20FROM%20users%20WHERE
+/owner/repo/issues/search?q=%3Cimg%20src%3D
+/owner/repo/pulls?q=SELECT%20%2A%20FROM%20users%20WHERE
+/owner/repo/pulls?q=%3Cimg%20src%3D
+/issues?type=your_repositories&q=SELECT%20%2A%20FROM%20users%20WHERE
+/issues?type=your_repositories&q=%3Cimg%20src%3D
+/issues/search?q=SELECT%20%2A%20FROM%20users%20WHERE
+/issues/search?q=%3Cimg%20src%3D
+/pulls?type=your_repositories&q=SELECT%20%2A%20FROM%20users%20WHERE
+/pulls?type=your_repositories&q=%3Cimg%20src%3D
+/owner/repo/commits/branch/main/search?q=SELECT%20%2A%20FROM%20users%20WHERE
+/owner/repo/commits/branch/main/search?q=%3Cimg%20src%3D
+/owner/repo/branches?q=SELECT%20%2A%20FROM%20users%20WHERE
+/owner/repo/branches?q=%3Cimg%20src%3D
+/owner/repo/tags?q=SELECT%20%2A%20FROM%20users%20WHERE
+/owner/repo/tags?q=%3Cimg%20src%3D
+/owner/-/packages?q=SELECT%20%2A%20FROM%20users%20WHERE
+/owner/-/packages?q=%3Cimg%20src%3D
+/user/search_candidates?q=SELECT%20%2A%20FROM%20users%20WHERE
+/user/search_candidates?q=%3Cimg%20src%3D
+/api/v1/repos/search?q=SELECT%20%2A%20FROM%20users%20WHERE
+/api/v1/repos/search?q=%3Cimg%20src%3D
+/api/v1/repos/issues/search?q=SELECT%20%2A%20FROM%20users%20WHERE
+/api/v1/repos/issues/search?q=%3Cimg%20src%3D
+/api/v1/repos/owner/repo/issues?q=SELECT%20%2A%20FROM%20users%20WHERE
+/api/v1/repos/owner/repo/issues?q=%3Cimg%20src%3D
+
+# Pages, raw files and edit pages of files, and the API's call for their
+# contents.
+/owner/repo/src/branch/main/package.json
+/owner/repo/raw/branch/main/package.json
+/owner/repo/_edit/main/package.json
+/api/v1/repos/owner/repo/contents/package.json
+/owner/repo/src/branch/main/.gitignore
+/owner/repo/raw/branch/main/.gitignore
+/owner/repo/_edit/main/.gitignore
+/api/v1/repos/owner/repo/contents/.gitignore
+/owner/repo/src/branch/main/docker-compose.yml
+/owner/repo/raw/branch/main/docker-compose.yml
+/owner/repo/_edit/main/docker-compose.yml
+/api/v1/repos/owner/repo/contents/docker-compose.yml
+/owner/repo/src/branch/main/Dockerfile
+/owner/repo/raw/branch/main/Dockerfile
+/owner/repo/_edit/main/Dockerfile
+/api/v1/repos/owner/repo/contents/Dockerfile
+/owner/repo/src/branch/main/.htaccess
+/owner/repo/raw/branch/main/.htaccess
+/owner/repo/_edit/main/.htaccess
+/api/v1/repos/owner/repo/contents/.htaccess
+/owner/repo/src/branch/main/rootfs/etc/passwd
+/owner/repo/raw/branch/main/rootfs/etc/passwd
+/owner/repo/_edit/main/rootfs/etc/passwd
+/api/v1/repos/owner/repo/contents/rootfs/etc/passwd
+/owner/repo/src/branch/main/bin/docker-entrypoint
+/owner/repo/raw/branch/main/bin/docker-entrypoint
+/owner/repo/_edit/main/bin/docker-entrypoint
+/api/v1/repos/owner/repo/contents/bin/docker-entrypoint
+/owner/repo/src/branch/main/scripts/python3-setup.sh
+/owner/repo/raw/branch/main/scripts/python3-setup.sh
+/owner/repo/_edit/main/scripts/python3-setup.sh
+/api/v1/repos/owner/repo/contents/scripts/python3-setup.sh
+/owner/repo/src/branch/main/src/java.base/share/classes/java/lang/Runtime.java
+/owner/repo/raw/branch/main/src/java.base/share/classes/java/lang/Runtime.java
+/owner/repo/_edit/main/src/java.base/share/classes/java/lang/Runtime.java
+/api/v1/repos/owner/repo/contents/src/java.base/share/classes/java/lang/Runtime.java
+/owner/repo/src/branch/main/java.lang.String.md
+/owner/repo/raw/branch/main/java.lang.String.md
+/owner/repo/_edit/main/java.lang.String.md
+/api/v1/repos/owner/repo/contents/java.lang.String.md
+/owner/repo/src/branch/main/META-INF/services/org.apache.commons.logging.LogFactory
+/owner/repo/raw/branch/main/META-INF/services/org.apache.commons.logging.LogFactory
+/owner/repo/_edit/main/META-INF/services/org.apache.commons.logging.LogFactory
+/api/v1/repos/owner/repo/contents/META-INF/services/org.apache.commons.logging.LogFactory
+/owner/repo/src/branch/main/process.env.d.ts
+/owner/repo/raw/branch/main/process.env.d.ts
+/owner/repo/_edit/main/process.env.d.ts
+/api/v1/repos/owner/repo/contents/process.env.d.ts
+/owner/repo/src/branch/main/document.write.js
+/owner/repo/raw/branch/main/document.write.js
+/owner/repo/_edit/main/document.write.js
+/api/v1/repos/owner/repo/contents/document.write.js
+/owner/repo/src/branch/main/test/fixtures/__proto__.json
+/owner/repo/raw/branch/main/test/fixtures/__proto__.json
+/owner/repo/_edit/main/test/fixtures/__proto__.json
+/api/v1/repos/owner/repo/contents/test/fixtures/__proto__.json
+/owner/repo/src/branch/main/install-script.sh
+/owner/repo/raw/branch/main/install-script.sh
+/owner/repo/_edit/main/install-script.sh
+/api/v1/repos/owner/repo/contents/install-script.sh
+/owner/repo/src/branch/main/src/backend/catalog/information_schema.sql
+/owner/repo/raw/branch/main/src/backend/catalog/information_schema.sql
+/owner/repo/_edit/main/src/backend/catalog/information_schema.sql
+/api/v1/repos/owner/repo/contents/src/backend/catalog/information_schema.sql
+/owner/repo/src/branch/main/docs/a%20b.xhtml
+/owner/repo/raw/branch/main/docs/a%20b.xhtml
+/owner/repo/_edit/main/docs/a%20b.xhtml
+/api/v1/repos/owner/repo/contents/docs/a%20b.xhtml
+/owner/repo/src/branch/main/%5Bdraft%5D.md
+/owner/repo/raw/branch/main/%5Bdraft%5D.md
+/owner/repo/_edit/main/%5Bdraft%5D.md
+/api/v1/repos/owner/repo/contents/%5Bdraft%5D.md
+/owner/repo/src/branch/main/notes.txt~
+/owner/repo/raw/branch/main/notes.txt~
+/owner/repo/_edit/main/notes.txt~
+/api/v1/repos/owner/repo/contents/notes.txt~
+
+# The download, blame, history and delete pages of the files above whose names
+# the Core Rule Set checks in the path.
+/owner/repo/media/branch/main/notes.txt~
+/owner/repo/blame/branch/main/notes.txt~
+/owner/repo/commits/branch/main/notes.txt~
+/owner/repo/_delete/main/notes.txt~
+/owner/repo/media/branch/main/process.env.d.ts
+/owner/repo/blame/branch/main/process.env.d.ts
+/owner/repo/commits/branch/main/process.env.d.ts
+/owner/repo/_delete/main/process.env.d.ts
+/owner/repo/media/branch/main/docs/a%20b.xhtml
+/owner/repo/blame/branch/main/docs/a%20b.xhtml
+/owner/repo/commits/branch/main/docs/a%20b.xhtml
+/owner/repo/_delete/main/docs/a%20b.xhtml
+/owner/repo/media/branch/main/java.lang.String.md
+/owner/repo/blame/branch/main/java.lang.String.md
+/owner/repo/commits/branch/main/java.lang.String.md
+/owner/repo/_delete/main/java.lang.String.md
+
+# File names in the query string: the commit graph of a file, the API's lists
+# of its commits and of its contents, an issue opened from a template, and the
+# sign-in page on the way to its edit page.
+/owner/repo/graph?file=package.json
+/api/v1/repos/owner/repo/commits?path=package.json
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22package.json%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Fpackage.json
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Fpackage.json
+/owner/repo/graph?file=.gitignore
+/api/v1/repos/owner/repo/commits?path=.gitignore
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22.gitignore%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2F.gitignore
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2F.gitignore
+/owner/repo/graph?file=docker-compose.yml
+/api/v1/repos/owner/repo/commits?path=docker-compose.yml
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22docker-compose.yml%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Fdocker-compose.yml
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Fdocker-compose.yml
+/owner/repo/graph?file=.htaccess
+/api/v1/repos/owner/repo/commits?path=.htaccess
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22.htaccess%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2F.htaccess
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2F.htaccess
+/owner/repo/graph?file=rootfs%2Fetc%2Fpasswd
+/api/v1/repos/owner/repo/commits?path=rootfs%2Fetc%2Fpasswd
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22rootfs%2Fetc%2Fpasswd%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Frootfs%2Fetc%2Fpasswd
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Frootfs%2Fetc%2Fpasswd
+/owner/repo/graph?file=bin%2Fdocker-entrypoint
+/api/v1/repos/owner/repo/commits?path=bin%2Fdocker-entrypoint
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22bin%2Fdocker-entrypoint%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Fbin%2Fdocker-entrypoint
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Fbin%2Fdocker-entrypoint
+/owner/repo/graph?file=scripts%2Fpython3-setup.sh
+/api/v1/repos/owner/repo/commits?path=scripts%2Fpython3-setup.sh
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22scripts%2Fpython3-setup.sh%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Fscripts%2Fpython3-setup.sh
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Fscripts%2Fpython3-setup.sh
+/owner/repo/graph?file=src%2Fjava.base%2Fshare%2Fclasses%2Fjava%2Flang%2FRuntime.java
+/api/v1/repos/owner/repo/commits?path=src%2Fjava.base%2Fshare%2Fclasses%2Fjava%2Flang%2FRuntime.java
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22src%2Fjava.base%2Fshare%2Fclasses%2Fjava%2Flang%2FRuntime.java%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Fsrc%2Fjava.base%2Fshare%2Fclasses%2Fjava%2Flang%2FRuntime.java
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Fsrc%2Fjava.base%2Fshare%2Fclasses%2Fjava%2Flang%2FRuntime.java
+/owner/repo/graph?file=java.lang.String.md
+/api/v1/repos/owner/repo/commits?path=java.lang.String.md
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22java.lang.String.md%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Fjava.lang.String.md
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Fjava.lang.String.md
+/owner/repo/graph?file=META-INF%2Fservices%2Forg.apache.commons.logging.LogFactory
+/api/v1/repos/owner/repo/commits?path=META-INF%2Fservices%2Forg.apache.commons.logging.LogFactory
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22META-INF%2Fservices%2Forg.apache.commons.logging.LogFactory%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2FMETA-INF%2Fservices%2Forg.apache.commons.logging.LogFactory
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2FMETA-INF%2Fservices%2Forg.apache.commons.logging.LogFactory
+/owner/repo/graph?file=process.env.d.ts
+/api/v1/repos/owner/repo/commits?path=process.env.d.ts
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22process.env.d.ts%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Fprocess.env.d.ts
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Fprocess.env.d.ts
+/owner/repo/graph?file=document.write.js
+/api/v1/repos/owner/repo/commits?path=document.write.js
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22document.write.js%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Fdocument.write.js
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Fdocument.write.js
+/owner/repo/graph?file=test%2Ffixtures%2F__proto__.json
+/api/v1/repos/owner/repo/commits?path=test%2Ffixtures%2F__proto__.json
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22test%2Ffixtures%2F__proto__.json%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Ftest%2Ffixtures%2F__proto__.json
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Ftest%2Ffixtures%2F__proto__.json
+/owner/repo/graph?file=install-script.sh
+/api/v1/repos/owner/repo/commits?path=install-script.sh
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22install-script.sh%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Finstall-script.sh
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Finstall-script.sh
+/owner/repo/graph?file=src%2Fbackend%2Fcatalog%2Finformation_schema.sql
+/api/v1/repos/owner/repo/commits?path=src%2Fbackend%2Fcatalog%2Finformation_schema.sql
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22src%2Fbackend%2Fcatalog%2Finformation_schema.sql%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Fsrc%2Fbackend%2Fcatalog%2Finformation_schema.sql
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Fsrc%2Fbackend%2Fcatalog%2Finformation_schema.sql
+/owner/repo/graph?file=docs%2Fa%20b.xhtml
+/api/v1/repos/owner/repo/commits?path=docs%2Fa%20b.xhtml
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22docs%2Fa%20b.xhtml%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Fdocs%2Fa%20b.xhtml
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Fdocs%2Fa%20b.xhtml
+/owner/repo/graph?file=%5Bdraft%5D.md
+/api/v1/repos/owner/repo/commits?path=%5Bdraft%5D.md
+/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22%5Bdraft%5D.md%22%5D%7D
+/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2F%5Bdraft%5D.md
+/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2F%5Bdraft%5D.md
+
+# File names of attachments uploaded through the API, to a release, an issue and
+# a comment.
+/api/v1/repos/owner/repo/releases/1/assets?name=package.json
+/api/v1/repos/owner/repo/releases/1/assets?name=.gitignore
+/api/v1/repos/owner/repo/releases/1/assets?name=docker-compose.yml
+/api/v1/repos/owner/repo/releases/1/assets?name=.htaccess
+/api/v1/repos/owner/repo/releases/1/assets?name=docker-entrypoint
+/api/v1/repos/owner/repo/releases/1/assets?name=python3-setup.sh
+/api/v1/repos/owner/repo/releases/1/assets?name=Runtime.java
+/api/v1/repos/owner/repo/releases/1/assets?name=org.apache.commons.logging.LogFactory
+/api/v1/repos/owner/repo/releases/1/assets?name=%5Bdraft%5D.md
+/api/v1/repos/owner/repo/releases/1/assets?name=notes.txt~
+/api/v1/repos/owner/repo/releases/1/assets?name=install-script.sh
+/api/v1/repos/owner/repo/issues/1/assets?name=install-script.sh
+/api/v1/repos/owner/repo/issues/comments/1/assets?name=install-script.sh
+/api/v1/repos/owner/repo/releases/1/assets?name=process.env.d.ts
+/api/v1/repos/owner/repo/issues/1/assets?name=process.env.d.ts
+/api/v1/repos/owner/repo/issues/comments/1/assets?name=process.env.d.ts
+/api/v1/repos/owner/repo/releases/1/assets?name=java.lang.String.md
+/api/v1/repos/owner/repo/issues/1/assets?name=java.lang.String.md
+/api/v1/repos/owner/repo/issues/comments/1/assets?name=java.lang.String.md
+/api/v1/repos/owner/repo/releases/1/assets?name=information_schema.sql
+/api/v1/repos/owner/repo/issues/1/assets?name=information_schema.sql
+/api/v1/repos/owner/repo/issues/comments/1/assets?name=information_schema.sql
+/api/v1/repos/owner/repo/releases/1/assets?name=document.write.js
+/api/v1/repos/owner/repo/issues/1/assets?name=document.write.js
+/api/v1/repos/owner/repo/issues/comments/1/assets?name=document.write.js
+/api/v1/repos/owner/repo/releases/1/assets?name=__proto__.json
+/api/v1/repos/owner/repo/issues/1/assets?name=__proto__.json
+/api/v1/repos/owner/repo/issues/comments/1/assets?name=__proto__.json
+/api/v1/repos/owner/repo/releases/1/assets?name=index.xhtml
+/api/v1/repos/owner/repo/issues/1/assets?name=index.xhtml
+/api/v1/repos/owner/repo/issues/comments/1/assets?name=index.xhtml
+
+# An artifact upload from actions/upload-artifact@v3, which sends Content-Range.
+/api/actions_pipeline/_apis/pipelines/workflows/1/artifacts/9b7c1f3a/upload?itemPath=artifact%2Freport.txt Content-Range: bytes 0-9/10
+
+# Branch and tag names in the query string: deleting and restoring a branch,
+# starting a release from a tag, a branch protection rule, a directory listing's
+# last commits, and a container image push that reuses a layer.
+/owner/repo/branches/delete?name=docker-build&page=1
+/owner/repo/branches/restore?branch_id=1&name=docker-build&page=1
+/owner/repo/releases/new?tag=docker-build
+/owner/repo/settings/branches/edit?rule_name=docker-build
+/owner/repo/lastcommit/main/src?refSubUrl=branch%2Fdocker-build
+/v2/owner/app/blobs/uploads/?mount=sha256%3A0000&from=owner%2Fdocker-build
+/owner/repo/branches/delete?name=feat%2Fdocker-support&page=1
+/owner/repo/branches/restore?branch_id=1&name=feat%2Fdocker-support&page=1
+/owner/repo/releases/new?tag=feat%2Fdocker-support
+/owner/repo/settings/branches/edit?rule_name=feat%2Fdocker-support
+/owner/repo/lastcommit/main/src?refSubUrl=branch%2Ffeat%2Fdocker-support
+/v2/owner/app/blobs/uploads/?mount=sha256%3A0000&from=owner%2Ffeat%2Fdocker-support
+/owner/repo/branches/delete?name=renovate%2Fdocker-build-push-action-6.x&page=1
+/owner/repo/branches/restore?branch_id=1&name=renovate%2Fdocker-build-push-action-6.x&page=1
+/owner/repo/releases/new?tag=renovate%2Fdocker-build-push-action-6.x
+/owner/repo/settings/branches/edit?rule_name=renovate%2Fdocker-build-push-action-6.x
+/owner/repo/lastcommit/main/src?refSubUrl=branch%2Frenovate%2Fdocker-build-push-action-6.x
+/v2/owner/app/blobs/uploads/?mount=sha256%3A0000&from=owner%2Frenovate%2Fdocker-build-push-action-6.x
+/owner/repo/branches/delete?name=python3-migration&page=1
+/owner/repo/branches/restore?branch_id=1&name=python3-migration&page=1
+/owner/repo/releases/new?tag=python3-migration
+/owner/repo/settings/branches/edit?rule_name=python3-migration
+/owner/repo/lastcommit/main/src?refSubUrl=branch%2Fpython3-migration
+/v2/owner/app/blobs/uploads/?mount=sha256%3A0000&from=owner%2Fpython3-migration
+/owner/repo/branches/delete?name=ansible-roles&page=1
+/owner/repo/branches/restore?branch_id=1&name=ansible-roles&page=1
+/owner/repo/releases/new?tag=ansible-roles
+/owner/repo/settings/branches/edit?rule_name=ansible-roles
+/owner/repo/lastcommit/main/src?refSubUrl=branch%2Fansible-roles
+/v2/owner/app/blobs/uploads/?mount=sha256%3A0000&from=owner%2Fansible-roles
+/owner/repo/branches/delete?name=whoami&page=1
+/owner/repo/branches/restore?branch_id=1&name=whoami&page=1
+/owner/repo/releases/new?tag=whoami
+/owner/repo/settings/branches/edit?rule_name=whoami
+/owner/repo/lastcommit/main/src?refSubUrl=branch%2Fwhoami
+/v2/owner/app/blobs/uploads/?mount=sha256%3A0000&from=owner%2Fwhoami
+
+# Pages a signed-in user opens.
+/
+/owner/repo
+/owner/repo/issues
+/owner/repo/pulls
+/owner/repo/releases
+/owner/repo/wiki
+/owner/repo/activity
+/owner/repo/branches
+/owner/repo/tags
+/owner/repo/settings
+/owner/repo/actions
+/owner/repo/compare/main...main
+/owner/repo/commits/branch/main
+/owner/repo/archive/main.zip
+/notifications
+/user/settings
+/user/settings/applications
+/explore/repos
+/-/admin

internal/waf/waf.go

@@ -1,8 +1,9 @@
 // Package waf runs the OWASP Core Rule Set 4.25.0, through Coraza, on the
 // method, the URL with its query and the headers of a request, and on its
-// body while SWWAF_WAF_BODY_LIMIT is set, with the six changes smallwebwaf
+// body while SWWAF_WAF_BODY_LIMIT is set, with the eight changes smallwebwaf
-// makes to it, as "Attack detection" under "Settings" in SPEC.md describes
+// makes to it and the exclusions in SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE, as
-// them. It reads no response.
+// "Attack detection" under "Settings" in SPEC.md describes them. It reads no
+// response.
 //
 // smallwebwaf writes only to its state directory, so Coraza is built with
 // its no_fs_access tag, as the Dockerfile and script/build build it: of a
@@ -11,10 +12,14 @@
 package waf
 
 import (
+	_ "embed"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
 	"net/netip"
+	"os"
+	"regexp"
 	"slices"
 	"strconv"
 	"strings"
@@ -26,12 +31,14 @@ import (
 )
 
 // directives are the Core Rule Set as smallwebwaf runs it, with the
-// paranoia level for %d, and bodyDirectives for %s while
+// paranoia level for %d, bodyDirectives for the first %s while
-// SWWAF_WAF_BODY_LIMIT is set. Each rule smallwebwaf adds has an id from
+// SWWAF_WAF_BODY_LIMIT is set, the exclusions file for the second, and
-// 900000 to 900999, the ids the Core Rule Set keeps for the rules that set
+// giteaExclusions for the third.
-// it up, which SWWAF_WAF_DISABLED_RULES refuses, so that no setting
+// Each rule smallwebwaf adds has an id from 900000 to 900999, the ids the
-// switches one off. Coraza joins a line ending in \ to the next, without
+// Core Rule Set keeps for the rules that set it up, which
-// the spaces at the start of the next.
+// SWWAF_WAF_DISABLED_RULES and the exclusions file refuse, so that no
+// setting switches one off. Coraza joins a line ending in \ to the next,
+// without the spaces at the start of the next.
 const directives = `
 # The engine only detects. smallwebwaf compares the request's anomaly
 # score with SWWAF_WAF_ANOMALY_THRESHOLD itself, in block and detect mode
@@ -69,6 +76,14 @@ SecArgumentsLimit 1000
 SecRule ARGUMENTS_LIMIT_REACHED "@eq 1" "id:900300,phase:2,pass,\
     severity:'CRITICAL',setvar:'tx.inbound_anomaly_score_pl1=+5'"
 
+# The exclusions file comes before the rules, where the Core Rule Set puts
+# its own file of exclusions that run before the rules, so that they run
+# before the rules of phase 1 too.
+%s
+
+# The eighth change comes before the rules for the same reason.
+%s
+
 # The sixth: only the rules for requests are loaded, and no response is
 # inspected.
 Include @owasp_crs/REQUEST-*.conf
@@ -96,10 +111,19 @@ SecRuleUpdateTargetById 932260 "!ARGS:path|!ARGS:files|!ARGS:skip-to|\
     !ARGS:artifactName|!ARGS:redirect_to"
 
 # The fifth, for Referer: it is not checked for a Unix command without
-# arguments, or for Java starting a process. The cookies are left out in
+# arguments, for Java starting a process, or for a Java class name. 944130
-# Inspect.
+# refused every page opened from the page of java.lang.String.md. The
+# cookies are left out in Inspect.
 SecRuleUpdateTargetById 932340 "!REQUEST_HEADERS:Referer"
 SecRuleUpdateTargetById 944110 "!REQUEST_HEADERS:Referer"
+SecRuleUpdateTargetById 944130 "!REQUEST_HEADERS:Referer"
+
+# The seventh: a container image push that reuses a layer names the image
+# it takes the layer from in the query parameter from, which is not
+# checked for command names. 932260 refused the push of a layer from
+# owner/python3-app.
+SecRule REQUEST_FILENAME "@rx ^/v2/.+/blobs/uploads/$" \
+    "id:900500,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932260;ARGS:from"
 `
 
 // bodyDirectives have the Core Rule Set read the part of a request body
@@ -144,6 +168,13 @@ SecRule MULTIPART_STRICT_ERROR "!@eq 0" "id:900450,phase:2,pass,\
     severity:'CRITICAL',setvar:'tx.inbound_anomaly_score_pl1=+5'"
 `
 
+// giteaExclusions are the eighth change: the fields of gitea's own
+// requests that skip the rules that refused them there, as Coraza
+// directives.
+//
+//go:embed gitea.conf
+var giteaExclusions string
+
 // cookiesNotRead are the cookies the Core Rule Set reads a request
 // without, the rest of the fifth change.
 //
@@ -160,6 +191,51 @@ type Params struct {
 	// BodyLimit is the most of a request body the Core Rule Set reads
 	// (SWWAF_WAF_BODY_LIMIT), 0 while it is off and it reads none.
 	BodyLimit int64
+	// ExclusionsFile is the path of a file of exclusions loaded before the
+	// Core Rule Set's rules (SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE), "" while
+	// there is none.
+	ExclusionsFile string
+}
+
+// The ids of smallwebwaf's own rules, which an exclusions file may not
+// name.
+const (
+	firstOwnRuleID = 900000
+	lastOwnRuleID  = 900999
+)
+
+// numberOrRange matches a number, or a range of numbers such as
+// 900000-900999.
+var numberOrRange = regexp.MustCompile(`(\d+)(?:-(\d+))?`)
+
+// errSmallwebwafRuleID is the error of an exclusions file that names an
+// id of smallwebwaf's own rules.
+var errSmallwebwafRuleID = errors.New("an id of smallwebwaf's own rules")
+
+// ownRuleNamed returns the first number or range in exclusions, the text
+// of an exclusions file, that takes in an id of smallwebwaf's own rules,
+// or "" if none does. Comment lines are skipped, as Coraza skips them.
+func ownRuleNamed(exclusions string) string {
+	for line := range strings.Lines(exclusions) {
+		if strings.HasPrefix(strings.TrimSpace(line), "#") {
+			continue
+		}
+
+		for _, match := range numberOrRange.FindAllStringSubmatch(line, -1) {
+			first, _ := strconv.Atoi(match[1])
+
+			last := first
+			if match[2] != "" {
+				last, _ = strconv.Atoi(match[2])
+			}
+
+			if first <= lastOwnRuleID && last >= firstOwnRuleID {
+				return match[0]
+			}
+		}
+	}
+
+	return ""
 }
 
 // CoreRuleSet is the Core Rule Set, ready to inspect requests. It is safe
@@ -169,16 +245,35 @@ type CoreRuleSet struct {
 	bodyLimit int64
 }
 
-// New returns the Core Rule Set with the six changes, at params'
+// New returns the Core Rule Set with the eight changes, at params'
-// paranoia level, without the rules it switches off, and reading request
+// paranoia level, without the rules it switches off, reading request
-// bodies up to params' limit.
+// bodies up to params' limit, and with params' exclusions file loaded
+// before the Core Rule Set's rules. An exclusions file that cannot be
+// read, does not parse or names an id of smallwebwaf's own rules is an
+// error.
 func New(params Params) (*CoreRuleSet, error) {
 	body := ""
 	if params.BodyLimit > 0 {
 		body = fmt.Sprintf(bodyDirectives, params.BodyLimit)
 	}
 
-	text := fmt.Sprintf(directives, params.ParanoiaLevel, body)
+	exclusions := ""
+
+	if params.ExclusionsFile != "" {
+		file, err := os.ReadFile(params.ExclusionsFile)
+		if err != nil {
+			return nil, fmt.Errorf("read the exclusions file: %w", err)
+		}
+
+		exclusions = string(file)
+
+		if named := ownRuleNamed(exclusions); named != "" {
+			return nil, fmt.Errorf("the exclusions file names %s: %w", named,
+				errSmallwebwafRuleID)
+		}
+	}
+
+	text := fmt.Sprintf(directives, params.ParanoiaLevel, body, exclusions, giteaExclusions)
 
 	if len(params.DisabledRules) > 0 {
 		ids := make([]string, len(params.DisabledRules))

internal/waf/waf_test.go

@@ -5,6 +5,7 @@ import (
 	"net/http/httptest"
 	"net/netip"
 	"net/url"
+	"os"
 	"path/filepath"
 	"reflect"
 	"strconv"
@@ -119,7 +120,7 @@ func atDefaults(t *testing.T) *waf.CoreRuleSet {
 }
 
 // wantChange checks that crs lets through passes, a gitea request one of
-// the six changes is for, and still finds result in refused, a request
+// the eight 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 *waf.CoreRuleSet, passes, refused request, result waf.Result,
@@ -308,13 +309,14 @@ func TestCookiesGiteaFlashAndRedirectToAreNotRead(t *testing.T) {
 		matched(930120))
 }
 
-func TestRefererIsNotCheckedForACommandOrJavaStartingAProcess(t *testing.T) {
+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)
@@ -323,6 +325,8 @@ func TestRefererIsNotCheckedForACommandOrJavaStartingAProcess(t *testing.T) {
 		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,
@@ -362,6 +366,167 @@ func TestEachDisabledRuleIsSwitchedOff(t *testing.T) {
 	wantResult(t, newCoreRuleSet(t, 1, 920350, 911100), r, waf.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) (*waf.CoreRuleSet, error) {
+	return waf.New(waf.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 := waf.New(waf.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~"), waf.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()
+
+	for _, path := range []string{
+		filepath.Join(t.TempDir(), "missing.conf"),
+		exclusionsFile(t, "SecNoSuchDirective On\n"),
+		// The Core Rule Set's rules are not loaded yet.
+		exclusionsFile(t, "SecRuleUpdateTargetById 942100 \"!ARGS:id\"\n"),
+		// smallwebwaf's own rules may not be switched off or changed, by
+		// id or in a range.
+		exclusionsFile(t, "SecRuleRemoveById 900300\n"),
+		exclusionsFile(t, "SecRuleRemoveById 899999-901000\n"),
+		exclusionsFile(t, "SecAction \"id:1,phase:1,pass,nolog,"+
+			"ctl:ruleRemoveById=899999-901000\"\n"),
+		exclusionsFile(t, "SecAction \"id:1,phase:1,pass,nolog,"+
+			"ctl:ruleRemoveTargetById=900500;ARGS:from\"\n"),
+	} {
+		_, err := withExclusions(path)
+		if err == nil {
+			t.Errorf("%s loaded", path)
+		}
+	}
+}
+
+// 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
+}
+
+func TestOrdinaryGiteaRequestsPassAndAttacksAreRefused(t *testing.T) {
+	t.Parallel()
+
+	const threshold = 5 // SWWAF_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{
+			"1'%20OR%20'1'='1",
+			"..%2Fcustom%2Fconf%2Fapp.ini",
+			"%3Cscript%3Ealert(1)%3C%2Fscript%3E",
+		} {
+			target := "/owner/repo?" + parameter + "=" + attack
+			if got := inspect(t, crs, get(target)); got.Score < threshold {
+				t.Errorf("%s let through: %+v", target, got)
+			}
+		}
+	}
+}
+
 // bodyLimit is SWWAF_WAF_BODY_LIMIT in the tests that read bodies.
 const bodyLimit = 8 << 10