Gitea setup: Core Rule Set blocks attacks, not ordinary Gitea traffic (closes #198)

The Gitea setup runs the Core Rule Set in block mode. Rules that refused
ordinary Gitea requests are switched off only where they misfired:

- deploy/gitea/crs-exclusions.conf, loaded through the new setting
  SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE before the Core Rule Set's rules,
  covers Gitea's search, file-name and branch-name fields, Referer, file
  paths, API attachment names and Actions artifact uploads;
- smallwebwaf's defaults gain a seventh change: the registry upload
  path's from parameter skips 932260.

A file that cannot be read, does not parse or names an id from 900000
to 900999 stops servewaf at start, in every mode. internal/waf's tests
and script/gitea-setup send the recorded requests in
internal/waf/testdata/gitea-requests.txt and three attacks.

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
-  it has no `_FILE` form, and no `SWRP_` setting has one, since `rproxy` never
-  touches disk.
+  forms stops the start. `SWWAF_LOG_REMOTE_TLS_CA_FILE` and
+  `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE` already name a file, so they have no
+  `_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; `deploy/gitea/crs-exclusions.conf` is gitea's.       |
 | `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 +637,14 @@ 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 seven 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
   [`SPEC.md`](SPEC.md) lists them.
+- `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE` switches single rules off for an app's
+  own fields or paths. gitea's exclusions, in
+  `deploy/gitea/crs-exclusions.conf`, let its searches, file names and branch
+  names through.
 - 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 seven 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`
-  already holds a file name, so it has no `_FILE` form. No `SWRP_` setting has
-  one, since `rproxy` never touches disk.
+  so does naming a file that cannot be read. `SWWAF_LOG_REMOTE_TLS_CA_FILE` and
+  `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE` already hold a file name, so they have
+  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.
+  `deploy/gitea/crs-exclusions.conf` 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 seven 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:
 
@@ -669,6 +689,10 @@ every app, and no setting undoes them:
       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.
 
 The parameter and cookie names in these changes are matched without regard to
 case, as Coraza matches them.

deploy/gitea/compose.yaml

@@ -104,11 +104,12 @@ services:
             # address of an automation fleet on another host here too; without
             # that, it is counted like any client.
             SWWAF_ALLOW_NETS: 10.99.0.128/25,fd10:99:0:0:8000::/65
-            # In block mode the Core Rule Set refuses everyday Gitea searches
-            # and file names, and 31 refusals in a minute ban the address.
-            SWWAF_WAF_MODE: detect
+            # The Core Rule Set's exclusions for Gitea's searches, file names
+            # and branch names.
+            SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE: /etc/smallwebwaf/crs-exclusions.conf
         volumes:
             - servewaf-state:/var/lib/smallwebwaf
+            - ./crs-exclusions.conf:/etc/smallwebwaf/crs-exclusions.conf:ro
         networks:
             - shared
         logging: *logging

deploy/gitea/crs-exclusions.conf

@@ -0,0 +1,150 @@
+# The Core Rule Set's exclusions for Gitea, which servewaf loads from
+# SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE. servewaf loads this file before the Core
+# Rule Set's rules, so it holds only exclusions made while a request is checked:
+# SecAction and SecRule lines with ctl:ruleRemoveTargetById or
+# ctl:ruleRemoveById. Each switches one rule off for the Gitea fields or paths
+# where it refused ordinary Gitea requests. A SecAction applies on every path, a
+# SecRule on the paths it matches. Gitea sends these in the query string:
+#   - q: the text of every search;
+#   - file, path, template, body and redirect_to: a file name, alone or in
+#     JSON or a link;
+#   - name, tag, rule_name and refSubUrl: a branch or tag name.
+# docs/gitea.md says how to add an exclusion.
+
+# Searches.
+# 930110: a search for ../
+SecAction "id:10001,phase:1,pass,nolog,ctl:ruleRemoveTargetById=930110;ARGS:q"
+# 931100: a search for http://127.0.0.1:8080
+SecAction "id:10002,phase:1,pass,nolog,ctl:ruleRemoveTargetById=931100;ARGS:q"
+# 932140: a search for if (a == b) {
+SecAction "id:10003,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932140;ARGS:q"
+# 932235: a search for `make check`
+SecAction "id:10004,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932235;ARGS:q"
+# 932250: a search for ls -la
+SecAction "id:10005,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932250;ARGS:q"
+# 932380: a search for `whoami`
+SecAction "id:10006,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932380;ARGS:q"
+# 933100: a search for <?php echo
+SecAction "id:10007,phase:1,pass,nolog,ctl:ruleRemoveTargetById=933100;ARGS:q"
+# 933130: a search for $_GET[
+SecAction "id:10008,phase:1,pass,nolog,ctl:ruleRemoveTargetById=933130;ARGS:q"
+# 933135: a search for ${VAR}
+SecAction "id:10009,phase:1,pass,nolog,ctl:ruleRemoveTargetById=933135;ARGS:q"
+# 934110: a search for http://127.0.0.1:8080
+SecAction "id:10010,phase:1,pass,nolog,ctl:ruleRemoveTargetById=934110;ARGS:q"
+# 941100: a search for <script>
+SecAction "id:10011,phase:1,pass,nolog,ctl:ruleRemoveTargetById=941100;ARGS:q"
+# 941110: a search for <script>, or a page opened from its results
+SecAction "id:10012,phase:1,pass,nolog,\
+    ctl:ruleRemoveTargetById=941110;ARGS:q,\
+    ctl:ruleRemoveTargetById=941110;REQUEST_HEADERS:Referer"
+# 941120: a page opened from the results of a search for onClick={
+SecAction "id:10013,phase:1,pass,nolog,\
+    ctl:ruleRemoveTargetById=941120;REQUEST_HEADERS:Referer"
+# 941160: a search for <img src=, or a page opened from its results
+SecAction "id:10014,phase:1,pass,nolog,\
+    ctl:ruleRemoveTargetById=941160;ARGS:q,\
+    ctl:ruleRemoveTargetById=941160;REQUEST_HEADERS:Referer"
+# 941390: a search for fetch(
+SecAction "id:10015,phase:1,pass,nolog,ctl:ruleRemoveTargetById=941390;ARGS:q"
+# 942100: a search for SELECT * FROM users WHERE, or a page opened from the
+# results of a search for LIKE '%foo%'
+SecAction "id:10016,phase:1,pass,nolog,\
+    ctl:ruleRemoveTargetById=942100;ARGS:q,\
+    ctl:ruleRemoveTargetById=942100;REQUEST_HEADERS:Referer"
+# 942190: a search for union select
+SecAction "id:10017,phase:1,pass,nolog,ctl:ruleRemoveTargetById=942190;ARGS:q"
+# 942230: a search for if (a == b) {
+SecAction "id:10018,phase:1,pass,nolog,ctl:ruleRemoveTargetById=942230;ARGS:q"
+# 944100: a search for java.lang.Runtime, or a page opened from its results
+SecAction "id:10019,phase:1,pass,nolog,\
+    ctl:ruleRemoveTargetById=944100;ARGS:q,\
+    ctl:ruleRemoveTargetById=944100;REQUEST_HEADERS:Referer"
+
+# Searches, and file, branch and tag names.
+# 930120: a search for package.json, or the commit graph of .gitignore
+SecAction "id:10020,phase:1,pass,nolog,ctl:ruleRemoveTargetById=930120;\
+    ARGS:/^(?:q|file|template|body|refsuburl|name|tag|rule_name)$/"
+# 932160: a search for /bin/sh, or the API's contents of bin/docker-entrypoint
+SecAction "id:10021,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932160;\
+    ARGS:/^(?:q|file|template|body|refsuburl|name|tag|rule_name)$/"
+# 932260: a search for python3, or deleting the branch docker-build
+SecAction "id:10022,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932260;\
+    ARGS:/^(?:q|file|template|body|refsuburl|name|tag|rule_name)$/"
+
+# Searches, and file names in the query string.
+# 932120: a search for Invoke-WebRequest, or the commits of install-script.sh
+SecAction "id:10023,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932120;\
+    ARGS:/^(?:q|file|path|template|body|redirect_to)$/"
+# 932130: a search for $(pwd), or an issue opened from the template [draft].md
+SecAction "id:10024,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932130;\
+    ARGS:/^(?:q|file|path|template|body|redirect_to)$/"
+# 934100: a search for process.env, or the commits of process.env.d.ts
+SecAction "id:10025,phase:1,pass,nolog,ctl:ruleRemoveTargetById=934100;\
+    ARGS:/^(?:q|file|path|template|body|redirect_to)$/"
+# 934130: a search for __proto__, or the commits of __proto__.json
+SecAction "id:10026,phase:1,pass,nolog,ctl:ruleRemoveTargetById=934130;\
+    ARGS:/^(?:q|file|path|template|body|redirect_to)$/"
+# 941130: the commits of index.xhtml
+SecAction "id:10027,phase:1,pass,nolog,ctl:ruleRemoveTargetById=941130;\
+    ARGS:/^(?:file|path|template|body|redirect_to)$/"
+# 941180: a search for document.cookie, or the commits of document.write.js
+SecAction "id:10028,phase:1,pass,nolog,ctl:ruleRemoveTargetById=941180;\
+    ARGS:/^(?:q|file|path|template|body|redirect_to)$/"
+# 942140: a search for information_schema, or the commits of
+# information_schema.sql
+SecAction "id:10029,phase:1,pass,nolog,ctl:ruleRemoveTargetById=942140;\
+    ARGS:/^(?:q|file|path|template|body|redirect_to)$/"
+# 944110: a search for java.lang.Runtime, or the commits of Runtime.java
+SecAction "id:10030,phase:1,pass,nolog,ctl:ruleRemoveTargetById=944110;\
+    ARGS:/^(?:q|file|path|template|body|redirect_to)$/"
+# 944130: a search for java.lang.Runtime, the commits of java.lang.String.md,
+# or any page opened from that file's page, which names it in the Referer
+SecAction "id:10031,phase:1,pass,nolog,\
+    ctl:ruleRemoveTargetById=944130;\
+    ARGS:/^(?:q|file|path|template|body|redirect_to)$/,\
+    ctl:ruleRemoveTargetById=944130;REQUEST_HEADERS:Referer"
+
+# File names in the path of a file's page, raw file, blame, history and edit
+# page, and of the API's calls for its contents.
+# 920500: the page of notes.txt~
+SecRule REQUEST_FILENAME "@rx ^/(?:api/v1/repos/)?[^/]+/[^/]+/(?:src|raw|media|blame|commits|_edit|_delete|contents)/" \
+    "id:10032,phase:1,pass,nolog,ctl:ruleRemoveTargetById=920500;REQUEST_FILENAME"
+# 934100: the page of process.env.d.ts
+SecRule REQUEST_FILENAME "@rx ^/(?:api/v1/repos/)?[^/]+/[^/]+/(?:src|raw|media|blame|commits|_edit|_delete|contents)/" \
+    "id:10033,phase:1,pass,nolog,ctl:ruleRemoveTargetById=934100;REQUEST_FILENAME"
+# 941130: the page of docs/a b.xhtml
+SecRule REQUEST_FILENAME "@rx ^/(?:api/v1/repos/)?[^/]+/[^/]+/(?:src|raw|media|blame|commits|_edit|_delete|contents)/" \
+    "id:10034,phase:1,pass,nolog,ctl:ruleRemoveTargetById=941130;REQUEST_FILENAME"
+# 944130: the page of java.lang.String.md
+SecRule REQUEST_FILENAME "@rx ^/(?:api/v1/repos/)?[^/]+/[^/]+/(?:src|raw|media|blame|commits|_edit|_delete|contents)/" \
+    "id:10035,phase:1,pass,nolog,ctl:ruleRemoveTargetById=944130;REQUEST_FILENAME"
+
+# The file name, in name, of an attachment uploaded through the API to a
+# release, an issue or a comment.
+# 932120: the attachment install-script.sh
+SecRule REQUEST_FILENAME "@rx ^/api/v1/repos/[^/]+/[^/]+/(?:releases|issues|issues/comments)/[0-9]+/assets$" \
+    "id:10036,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932120;ARGS:name"
+# 934100: the attachment process.env.d.ts
+SecRule REQUEST_FILENAME "@rx ^/api/v1/repos/[^/]+/[^/]+/(?:releases|issues|issues/comments)/[0-9]+/assets$" \
+    "id:10037,phase:1,pass,nolog,ctl:ruleRemoveTargetById=934100;ARGS:name"
+# 934130: the attachment __proto__.json
+SecRule REQUEST_FILENAME "@rx ^/api/v1/repos/[^/]+/[^/]+/(?:releases|issues|issues/comments)/[0-9]+/assets$" \
+    "id:10038,phase:1,pass,nolog,ctl:ruleRemoveTargetById=934130;ARGS:name"
+# 941130: the attachment index.xhtml
+SecRule REQUEST_FILENAME "@rx ^/api/v1/repos/[^/]+/[^/]+/(?:releases|issues|issues/comments)/[0-9]+/assets$" \
+    "id:10039,phase:1,pass,nolog,ctl:ruleRemoveTargetById=941130;ARGS:name"
+# 941180: the attachment document.write.js
+SecRule REQUEST_FILENAME "@rx ^/api/v1/repos/[^/]+/[^/]+/(?:releases|issues|issues/comments)/[0-9]+/assets$" \
+    "id:10040,phase:1,pass,nolog,ctl:ruleRemoveTargetById=941180;ARGS:name"
+# 942140: the attachment information_schema.sql
+SecRule REQUEST_FILENAME "@rx ^/api/v1/repos/[^/]+/[^/]+/(?:releases|issues|issues/comments)/[0-9]+/assets$" \
+    "id:10041,phase:1,pass,nolog,ctl:ruleRemoveTargetById=942140;ARGS:name"
+# 944130: the attachment java.lang.String.md
+SecRule REQUEST_FILENAME "@rx ^/api/v1/repos/[^/]+/[^/]+/(?:releases|issues|issues/comments)/[0-9]+/assets$" \
+    "id:10042,phase:1,pass,nolog,ctl:ruleRemoveTargetById=944130;ARGS:name"
+
+# The header Content-Range of an artifact upload.
+# 920450: an artifact upload from actions/upload-artifact@v3
+SecRule REQUEST_FILENAME "@rx ^/api/actions_pipeline/_apis/pipelines/workflows/[0-9]+/artifacts/[^/]+/upload$" \
+    "id:10043,phase:1,pass,nolog,ctl:ruleRemoveTargetById=920450;REQUEST_HEADERS_NAMES:Content-Range"

docs/gitea.md

@@ -13,7 +13,8 @@ Four containers share one Docker network, the shared network:
   plain HTTP to HTTPS;
 - `rproxy`, in front of gitea;
 - gitea 1.27.3, as its image comes;
-- `servewaf`, with a volume for its state files.
+- `servewaf`, with a volume for its state files, and with
+  `deploy/gitea/crs-exclusions.conf` mounted read-only.
 
 To start it:
 
@@ -30,7 +31,8 @@ To start it:
    `docker run --rm <gitea's image> gitea generate secret SECRET_KEY`, with
    gitea's image as `deploy/gitea/compose.yaml` names it. Do this once per
    install, and keep the key.
-5. Run `docker compose up --detach` in `deploy/gitea`.
+5. Run `docker compose up --detach` in `deploy/gitea`, with
+   `crs-exclusions.conf` beside `compose.yaml`.
 6. Make gitea's first user with `gitea admin user create`, in gitea's container,
    as the user `git`.
 
@@ -46,6 +48,12 @@ under a name of its own, and checks:
   `rproxy`, and that `servewaf` checks them;
 - that gitea logs the visitor's address, not `rproxy`'s;
 - that a request from a container on the shared network skips the checks;
+- that the Core Rule Set refuses none of the ordinary gitea requests in
+  `internal/waf/testdata/gitea-requests.txt`, sent by a signed-in user;
+- that it refuses none of the API calls with JSON bodies;
+- that it refuses no fetch;
+- that it refuses SQL injection, path traversal and script injection in a query
+  string;
 - that with `servewaf` stopped, gitea still answers through `rproxy`.
 
 ## Uploads and downloads
@@ -79,11 +87,8 @@ GiB a day.
 
 ## The checks
 
-`SWWAF_WAF_MODE` is `detect`. The Core Rule Set then logs a match, with its rule
-ids, and refuses nothing. In `block` mode, the default, it refuses everyday
-gitea searches and file names. The section "What the Core Rule Set refuses in
-`block` mode" below lists them. Each such refusal counts toward the error burst,
-so 31 in one minute ban the address.
+The Core Rule Set runs in `block` mode, the default, with gitea's exclusions
+(see "The Core Rule Set's exclusions" below).
 
 Every other check stays at its default. A client may make 120 requests a minute,
 1,500 an hour and 6,000 a day. Archive downloads and blame and history pages are
@@ -153,188 +158,49 @@ within two minutes. Its address is then banned, its running jobs fail, and each
 repeat within a day makes the ban longer. Newer runners ask for work less often.
 Put the runners' addresses in `SWWAF_RATE_LIMIT_EXEMPT_NETS`.
 
-## What the Core Rule Set refuses in `block` mode
+## The Core Rule Set's exclusions
 
-These notes record what the Core Rule Set does in front of gitea in `block`
-mode, at the other defaults. They are observations, not requirements.
-`script/gitea-requests` runs gitea behind `rproxy` and `servewaf` at the
-defaults. It sends through them a sample of gitea's ordinary use and the
-requests named below. It reports each request the Core Rule Set refuses, so that
-these notes can be checked again when gitea or the Core Rule Set changes
-version. In `detect` mode, as the setup runs it, the same requests are logged
-with their rule ids, and pass.
+`deploy/gitea/crs-exclusions.conf` switches single Core Rule Set rules off where
+they refused ordinary gitea requests. `servewaf` loads it from
+`SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE`, before the Core Rule Set's rules. Each
+exclusion covers one rule, in these places only:
 
-Each refusal answers only that request ("Bans" in `SPEC.md` says what it counts
-toward). The request log names the rule in `waf_rule_ids`, which
-`SWWAF_WAF_DISABLED_RULES` can switch off.
+- `q`, the text of every search;
+- the query parameters that hold a file name: `file`, `path`, `template`, `body`
+  and `redirect_to`;
+- the query parameters that hold a branch or tag name: `name`, `tag`,
+  `rule_name` and `refSubUrl`;
+- `Referer`, on a page opened from search results or from a file's page;
+- the path of a file's page, raw file, blame, history and edit page, and of the
+  API's call for its contents;
+- `name`, the file name of an attachment uploaded through the API;
+- the header `Content-Range` of an Actions artifact upload.
 
-### What it lets through
+gitea reads these as text to search for, as names in a repository, or, for
+`Content-Range`, as the part of a file an upload carries. It never runs them as
+SQL, a command or a page's script. So an attack that only the excluded rules
+would catch there reaches gitea and does nothing. Every other field and path
+keeps every rule.
 
-The Core Rule Set lets gitea's ordinary use through, apart from the refusals in
-the sections after this one:
+To add an exclusion for a request the Core Rule Set refuses:
 
-- browsing and views of files in a repository, with their history, blame and the
-  file tree;
-- diffs, including their hidden lines and large files, and pull request review;
-- git's clone, fetch and push over HTTP;
-- signing in, including the return to the page a visitor came from, and sign-in
-  with Git Credential Manager, git-credential-oauth or tea;
-- the API's calls for a file and its commits;
-- pushing and pulling container images and packages;
-- Actions runners, and artifacts uploaded with `actions/upload-artifact@v4`;
-- posting issues, pull requests, comments, wiki pages and files saved in the web
-  editor, code included, since no body is read;
-- the page gitea shows after a change, with its message naming what was done.
+1. Find the request in `servewaf`'s log. Its line gives the path and query, and
+   names the rules in `waf_rule_ids`.
+2. For each rule, add a line with `ctl:ruleRemoveTargetById` for the field it
+   matched. For a field on every path, copy one of the file's `SecAction` lines.
+   For some paths only, copy one of its `SecRule REQUEST_FILENAME` lines. Give
+   it a new id. An id from 900000 to 900999 stops the start.
+3. Above it, write a one-line comment naming the request it refused.
+4. Add the request to `internal/waf/testdata/gitea-requests.txt`, and run
+   `make check`.
+5. Restart `servewaf`.
 
-### A query string that reads as an attack
+The Core Rule Set still refuses the page of a file in a directory named `...`,
+which reads as path traversal.
 
-Most often this is a search. A search term is a query parameter, which the Core
-Rule Set checks against its lists of system files and commands (see the fourth
-change under "Attack detection" in `SPEC.md`). A release attachment uploaded
-through the API as `docker-compose.yml` is refused the same way. Examples:
+With `SWWAF_WAF_BODY_LIMIT` set, it also refuses issue text, comments, wiki
+pages and files saved in the web editor that hold shell commands or code.
 
-- a name on those lists, such as `package.json`, `.gitignore` or
-  `docker-compose.yml`;
-- text that starts with a command name, such as `python3` or `ssh key`, or has
-  one right after a `/` in its first word, such as `feat/docker-support`;
-- a shell command with its options or a system path (`ls -la`, `sed -i`,
-  `/bin/sh`), or a command in backticks;
-- script code (`fetch(`, `${VAR}`, `process.env`), HTML (`<img src=`) or an SQL
-  statement (`SELECT * FROM users WHERE`);
-- a URL naming an IP address or `localhost`.
-
-### A branch, tag or file name that starts with a command name
-
-The Core Rule Set's list of commands (932260) holds names such as `docker-`,
-`python3`, `ansible`, `base64` and `whoami`. A query parameter holding a branch,
-tag or file name that starts with one is refused. So is one that has such a name
-right after a `/`, such as `feat/docker-support`, `fix/docker-build` or
-`renovate/docker-build-push-action-6.x`. gitea's own pages send the name in a
-query parameter that 930120, 932160 and 932260 still check:
-
-- `refSubUrl`, the branch or tag of a directory listing. A listing sends it when
-  it asks for its entries' last commits in a second request. It does so whenever
-  gitea takes more than a second to work them out;
-- `name`, when a branch is deleted or restored on the branches page;
-- `tag`, when a release is started from a tag;
-- `template`, the file of an issue template, when an issue is opened from it;
-- `rule_name`, when a branch protection rule is opened for editing in the
-  repository's settings or has just been saved.
-
-What a visitor sees, for a branch named `docker-build`:
-
-- A directory listing that makes that second request leaves those last commits
-  out and shows an error.
-- The branches page shows an error instead of deleting or restoring the branch.
-- A release started from such a tag gets the `403` answer of `smallwebwaf` in
-  place of its form. So does an issue opened from such a template, and such a
-  rule opened for editing.
-- Saving such a rule stores it. gitea then returns to the branch settings page,
-  which gets the `403` answer, so the save looks as if it failed.
-
-### A file name in a query parameter that trips the code rules
-
-The Core Rule Set's rules for Java, script, PowerShell and SQL find what they
-look for in some file names. This holds too in the ten query parameters that
-930120, 932160 and 932260 do not check (see the fourth change under "Attack
-detection" in `SPEC.md`). Examples:
-
-- `runtime` in OpenJDK's `src/java.base/share/classes/java/lang/Runtime.java`
-  (944110);
-- a Java class, as in `java.lang.String.md` (944130);
-- `document.write.js` (941180);
-- `process.env.d.ts` (934100);
-- `__proto__` (934130);
-- the PowerShell command `Install-Script`, as in `install-script.sh` (932120);
-- a database's name, as in PostgreSQL's `information_schema.sql` (942140).
-
-For such a file, these requests are refused:
-
-- the API's list of its commits (`path`);
-- the API's call for the contents of files that names it in its query (`body`);
-- the commit graph of that file alone (`file`);
-- the hidden lines of its diff (`path`), which stay hidden;
-- the sign-in page, for a visitor who opens a page of the file that needs
-  signing in, such as its edit page (`redirect_to`). The visitor can still sign
-  in by opening the sign-in page itself.
-
-### A path
-
-- A file name ending in `~`, or an `.xhtml` file whose path holds a space.
-- A path that holds what the Core Rule Set takes for a Java class (944130), as
-  `java.lang.String.md` and
-  `META-INF/services/org.apache.commons.logging.LogFactory` do.
-- A path that holds what it takes for Node.js code (934100), as
-  `process.env.d.ts` does.
-- A path with a directory named `...` (930100, 930110), such as `.../notes.txt`.
-
-For such a file, these are refused:
-
-- the page of the file;
-- its raw file;
-- its history and its blame;
-- its edit page.
-
-The directory that holds it lists it, and a clone carries it.
-
-### A container image push that reuses a layer
-
-A push can reuse a layer of an image docker has pushed to that gitea before.
-docker then asks gitea to take the layer from that image, naming it in the query
-parameter `from`, which 932260 checks. The request is refused when the image's
-owner starts with an entry on the list of commands. It is refused too when the
-image's name after the owner starts with one. Examples are `owner/python3-app`,
-`owner/docker-base`, and any image of an owner named `ansible` or `docker-team`.
-
-What happens next depends on docker's image store. A docker that keeps its
-images in containerd's image store fails the push, and fails each new try the
-same way. A new install of Docker Engine 29 does this. A docker that keeps them
-in its own older image store uploads the layer instead. The push then succeeds
-after one refusal for each layer it reuses, and each of those refusals counts
-toward the error burst ("Attack detection" in `SPEC.md`).
-
-### Artifact uploads from `actions/upload-artifact@v3`
-
-This action sends the header `Content-Range`, which the Core Rule Set refuses
-(920450). The action sends two files at a time, does not retry a `403`, and
-sends no further file once one is refused. So an upload is refused once or
-twice, however many files it holds, and the step fails. One upload does not ban
-the runner. The error burst ("Attack detection" in `SPEC.md`) bans it after more
-than 30 such refusals from its address in a minute, as when many jobs upload at
-once. `actions/upload-artifact@v4` does not send the header.
-
-### What body inspection refuses
-
-With `SWWAF_WAF_BODY_LIMIT` set, the Core Rule Set reads request bodies too. In
-front of gitea it then refuses these, until their rule ids, named in the request
-log, are added to `SWWAF_WAF_DISABLED_RULES`:
-
-- issue and comment text, wiki pages and files saved in the web editor that hold
-  shell commands or code (932125, 932235, 932250 and others);
-- package descriptions that show code;
-- PyPI uploads (922130);
-- attachments named like `debug.log` or `config.yml` (932180).
-
-### What `script/gitea-requests` sends
-
-Of the requests above, the script sends:
-
-- for each file named under "A file name in a query parameter that trips the
-  code rules", the API's list of its commits;
-- for `Runtime.java` alone, the commit graph of that file, the hidden lines of
-  its diff, and the API's call for the contents of files that names it;
-- the sign-in page for a visitor who opens the edit page of `document.write.js`;
-- the pages of `java.lang.String.md`,
-  `META-INF/services/org.apache.commons.logging.LogFactory`, `process.env.d.ts`
-  and `.../notes.txt`;
-- one container image push that reuses a layer, which it does not try again.
-
-It does not send the raw file, history, blame or edit page of those four files,
-or the pages of the directories `META-INF/services` and `...`. It also sends a
-short sample of gitea's ordinary use:
-
-- signing in;
-- pages of files and commits, and a diff;
-- the API;
-- a push, and clone and fetch over HTTP;
-- two container image pushes.
+`make gitea-requests` runs gitea behind `rproxy` and `servewaf` at the defaults,
+without these exclusions. It reports each request the Core Rule Set refuses
+there.

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
-// most QuestionBodyMaxBytes less one byte: a question's body of
+// up to SWWAF_WAF_BODY_LIMIT, with the exclusions in
+// 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.
-func newCoreRuleSet(cfg *config.Config) *waf.CoreRuleSet {
-	if cfg.WAFMode == config.WAFModeOff {
-		return nil
+// JSON or XML body over its limit. An exclusions file that cannot be read, does
+// not parse or names an id of smallwebwaf's own rules is an error in every
+// mode. While the mode is off, a set file is loaded with the Core Rule Set only
+// 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:
-		// the paranoia level is from 1 to 4, and the id of no rule switches
-		// nothing off.
-		panic(err)
+		return nil, fmt.Errorf("SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE: %w", 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",
-			"error", err.Error())
+		processLog.Error("cannot listen on SWWAF_LISTEN_ADDR", "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/testdata/gitea-requests.txt

@@ -0,0 +1,337 @@
+# Ordinary gitea requests that the Core Rule Set must let through with
+# deploy/gitea/crs-exclusions.conf. 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,
+# and script/gitea-setup sends each to gitea through the setup 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/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/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
+/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/wiki/search?q=SELECT%20%2A%20FROM%20users%20WHERE
+/owner/repo/wiki/search?q=%3Cimg%20src%3D
+/owner/repo/branches?q=SELECT%20%2A%20FROM%20users%20WHERE
+/owner/repo/branches?q=%3Cimg%20src%3D
+/owner/repo/releases?q=SELECT%20%2A%20FROM%20users%20WHERE
+/owner/repo/releases?q=%3Cimg%20src%3D
+/owner/-/packages?q=SELECT%20%2A%20FROM%20users%20WHERE
+/owner/-/packages?q=%3Cimg%20src%3D
+/user/search?q=SELECT%20%2A%20FROM%20users%20WHERE
+/user/search?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~
+
+# 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 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?name=docker-build
+/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?name=feat%2Fdocker-support
+/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?name=renovate%2Fdocker-build-push-action-6.x
+/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?name=python3-migration
+/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?name=ansible-roles
+/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?name=whoami
+/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
-// makes to it, as "Attack detection" under "Settings" in SPEC.md describes
-// them. It reads no response.
+// body while SWWAF_WAF_BODY_LIMIT is set, with the seven changes smallwebwaf
+// makes to it and the exclusions in SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE, as
+// "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 +12,13 @@
 package waf
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
 	"net/netip"
+	"os"
+	"regexp"
 	"slices"
 	"strconv"
 	"strings"
@@ -26,12 +30,13 @@ import (
 )
 
 // directives are the Core Rule Set as smallwebwaf runs it, with the
-// paranoia level for %d, and bodyDirectives for %s while
-// SWWAF_WAF_BODY_LIMIT is set. Each rule smallwebwaf adds has an id from
-// 900000 to 900999, the ids the Core Rule Set keeps for the rules that set
-// it up, which SWWAF_WAF_DISABLED_RULES refuses, 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.
+// paranoia level for %d, bodyDirectives for the first %s while
+// SWWAF_WAF_BODY_LIMIT is set, and the exclusions file for the second.
+// Each rule smallwebwaf adds has an id from 900000 to 900999, the ids the
+// Core Rule Set keeps for the rules that set it up, which
+// 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 +74,11 @@ 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 sixth: only the rules for requests are loaded, and no response is
 # inspected.
 Include @owasp_crs/REQUEST-*.conf
@@ -100,6 +110,13 @@ SecRuleUpdateTargetById 932260 "!ARGS:path|!ARGS:files|!ARGS:skip-to|\
 # Inspect.
 SecRuleUpdateTargetById 932340 "!REQUEST_HEADERS:Referer"
 SecRuleUpdateTargetById 944110 "!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
@@ -160,6 +177,51 @@ 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 +231,35 @@ type CoreRuleSet struct {
 	bodyLimit int64
 }
 
-// New returns the Core Rule Set with the six changes, at params'
-// paranoia level, without the rules it switches off, and reading request
-// bodies up to params' limit.
+// New returns the Core Rule Set with the seven changes, at params'
+// paranoia level, without the rules it switches off, reading request
+// 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)
 
 	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 seven 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,
@@ -362,6 +363,167 @@ 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,
+// which script/gitea-setup sends too. 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 TestGiteaExclusionsLetOrdinaryGiteaRequestsThroughAndRefuseAttacks(t *testing.T) {
+	t.Parallel()
+
+	crs, err := withExclusions(filepath.Join("..", "..", "deploy", "gitea",
+		"crs-exclusions.conf"))
+	if err != nil {
+		t.Fatalf("load gitea's exclusions: %v", err)
+	}
+
+	const threshold = 5 // SWWAF_WAF_ANOMALY_THRESHOLD's default
+
+	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)
+		}
+	}
+
+	for _, attack := range []string{
+		"/owner/repo?id=1'%20OR%20'1'='1",
+		"/owner/repo?id=..%2Fcustom%2Fconf%2Fapp.ini",
+		"/owner/repo?id=%3Cscript%3Ealert(1)%3C%2Fscript%3E",
+	} {
+		if got := inspect(t, crs, get(attack)); got.Score < threshold {
+			t.Errorf("%s let through: %+v", attack, got)
+		}
+	}
+}
+
 // bodyLimit is SWWAF_WAF_BODY_LIMIT in the tests that read bodies.
 const bodyLimit = 8 << 10
 

script/gitea-requests

@@ -4,7 +4,8 @@
 # default but these: SWRP_UPSTREAM_URL names gitea's container, SWRP_WAF_BACKEND
 # names servewaf's, and SWWAF_LOG_REQUEST_HEADERS adds the header that labels a
 # request. Then send through rproxy the gitea requests that reading gitea's
-# source found the Core Rule Set refuses, which docs/gitea.md records, and a
+# source found the Core Rule Set refuses without the exclusions in
+# deploy/gitea/crs-exclusions.conf, and a
 # short sample of gitea's ordinary use: signing in, pages of files and commits,
 # a diff, the API, a push, clone and fetch over HTTP, and two container image
 # pushes. Last, print each request servewaf logged, with what it did with it and

script/gitea-setup

@@ -5,6 +5,12 @@
 #     rproxy, and that servewaf checks them;
 #   - that gitea logs the visitor's address, not rproxy's;
 #   - that a request from a container on the shared network skips the checks;
+#   - that the Core Rule Set refuses none of the ordinary gitea requests in
+#     internal/waf/testdata/gitea-requests.txt;
+#   - that it refuses none of the API calls with JSON bodies;
+#   - that it refuses no fetch;
+#   - that it refuses SQL injection, path traversal and script injection in a
+#     query string;
 #   - that with servewaf stopped, gitea still answers through rproxy.
 # It publishes no port of traefik's, since this host's ports 80 and 443 may be
 # taken. It reaches traefik at its address on the shared network instead, so
@@ -136,6 +142,71 @@ passed_through() {
         "\"client_ip\":\"$gateway\"" '"action":"forward"' '"counts":' '"waf_score":'
 }
 
+# refused: print each request servewaf logged as refused, for any reason.
+refused() {
+    compose logs --no-color --no-log-prefix servewaf 2>&1 |
+        grep -F '"servewaf_line":"report"' | grep -v -F '"action":"forward"' || true
+}
+
+# ordinary_requests: sign in as the owner, save a file and open an issue
+# through the API with JSON bodies, then send, signed in, each request in
+# internal/waf/testdata/gitea-requests.txt, with the header its line ends with,
+# if any, and that request's own address as its Referer, as a page opened from it
+# has. One a second keeps them under the default limit of 120 requests a minute,
+# since a request refused for a limit is never inspected. Fail if servewaf
+# refuses any of them.
+ordinary_requests() {
+    send /user/login --cookie-jar "$WORK/cookies" >/dev/null
+    status="$(send /user/login --cookie "$WORK/cookies" --cookie-jar "$WORK/cookies" \
+        --header "Origin: https://$SITE" --data-urlencode user_name=owner \
+        --data-urlencode "password=$PASSWORD")"
+    [ "$status" = 303 ] || fail "signing in was answered $status"
+
+    content="$(printf 'declare const env: Record<string, string>;\n' | base64)"
+    status="$(send /api/v1/repos/owner/repo/contents/process.env.d.ts \
+        --user "owner:$PASSWORD" --header "Content-Type: application/json" \
+        --data "{\"message\":\"Add process.env.d.ts\",\"content\":\"$content\"}")"
+    [ "$status" = 201 ] || fail "saving a file through the API was answered $status"
+    status="$(send /api/v1/repos/owner/repo/issues --user "owner:$PASSWORD" \
+        --header "Content-Type: application/json" \
+        --data '{"title":"ls -la fails","body":"SELECT * FROM users; <img src=x>"}')"
+    [ "$status" = 201 ] || fail "opening an issue through the API was answered $status"
+
+    grep -v -e '^#' -e '^$' "$ROOT/internal/waf/testdata/gitea-requests.txt" |
+        while read -r target header; do
+            if [ -n "$header" ]; then
+                send "$target" --globoff --cookie "$WORK/cookies" \
+                    --header "Referer: https://$SITE$target" --header "$header" >/dev/null
+            else
+                send "$target" --globoff --cookie "$WORK/cookies" \
+                    --header "Referer: https://$SITE$target" >/dev/null
+            fi
+            sleep 1
+        done
+
+    # The last request's report is logged once its answer has ended.
+    send /api/v1/settings/api >/dev/null
+    wait_for "servewaf logged no report of the last ordinary request" logged servewaf \
+        '"servewaf_line":"report"' '"path":"/api/v1/settings/api"'
+    refusals="$(refused)"
+    [ -z "$refusals" ] || fail "servewaf refused ordinary requests:
+$refusals"
+}
+
+# attacks: send SQL injection, path traversal and script injection in a query
+# string, and fail unless the Core Rule Set refuses each.
+attacks() {
+    # The traversal climbs one directory: the default rule file refuses two or
+    # more first, before the Core Rule Set runs.
+    for query in "id=1'%20OR%20'1'%3D'1" "id=..%2Fcustom%2Fconf%2Fapp.ini" \
+        "id=%3Cscript%3Ealert(1)%3C%2Fscript%3E"; do
+        status="$(send "/owner/repo?$query")"
+        [ "$status" = 403 ] || fail "the attack ?$query was answered $status"
+        wait_for "servewaf logged no refusal of ?$query" logged servewaf \
+            '"servewaf_line":"report"' '"action":"waf_blocked"' "\"query\":\"$query\""
+    done
+}
+
 main() {
     cd "$ROOT"
     trap cleanup EXIT
@@ -204,6 +275,12 @@ main() {
     esac
     echo "gitea-setup: a request from the shared network skips the checks"
 
+    site_git -C "$WORK/clone" fetch --quiet || fail "the fetch failed"
+    ordinary_requests
+    echo "gitea-setup: the Core Rule Set refuses no ordinary gitea request"
+    attacks
+    echo "gitea-setup: the Core Rule Set refuses the attacks"
+
     compose stop servewaf >/dev/null 2>&1 || fail "servewaf did not stop"
     status="$(send /owner/repo)"
     [ "$status" = 200 ] ||