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, covers Gitea's search, file-name
  and branch-name fields, Referer, and file paths;
- 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. 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 +585,14 @@ 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, which `servewaf` loads after the Core Rule Set and the
+  changes below. 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. The start stops on a file
+  that cannot be read or does not parse. It stops too on a file that names any
+  number from 900000 to 900999, the ids of `smallwebwaf`'s own rules.
+
 - `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 +622,7 @@ 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 +679,10 @@ 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). A
+   push that reuses a layer names there the image it takes the layer 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 +1,96 @@
+# The Core Rule Set's exclusions for Gitea, which servewaf loads from
+# SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE. Each switches one rule off for the
+# Gitea fields or paths where it refused ordinary Gitea requests. 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 ../
+SecRuleUpdateTargetById 930110 "!ARGS:q"
+# 931100: a search for http://127.0.0.1:8080
+SecRuleUpdateTargetById 931100 "!ARGS:q"
+# 932140: a search for if (a == b) {
+SecRuleUpdateTargetById 932140 "!ARGS:q"
+# 932235: a search for `make check`
+SecRuleUpdateTargetById 932235 "!ARGS:q"
+# 932250: a search for ls -la
+SecRuleUpdateTargetById 932250 "!ARGS:q"
+# 932380: a search for `whoami`
+SecRuleUpdateTargetById 932380 "!ARGS:q"
+# 933135: a search for ${VAR}
+SecRuleUpdateTargetById 933135 "!ARGS:q"
+# 934110: a search for http://127.0.0.1:8080
+SecRuleUpdateTargetById 934110 "!ARGS:q"
+# 941100: a search for <script>
+SecRuleUpdateTargetById 941100 "!ARGS:q"
+# 941110: a search for <script>, or a page opened from its results
+SecRuleUpdateTargetById 941110 "!ARGS:q|!REQUEST_HEADERS:Referer"
+# 941160: a search for <img src=, or a page opened from its results
+SecRuleUpdateTargetById 941160 "!ARGS:q|!REQUEST_HEADERS:Referer"
+# 941390: a search for fetch(
+SecRuleUpdateTargetById 941390 "!ARGS:q"
+# 942100: a search for SELECT * FROM users WHERE
+SecRuleUpdateTargetById 942100 "!ARGS:q"
+# 942190: a search for union select
+SecRuleUpdateTargetById 942190 "!ARGS:q"
+# 942230: a search for if (a == b) {
+SecRuleUpdateTargetById 942230 "!ARGS:q"
+# 944100: a search for java.lang.Runtime, or a page opened from its results
+SecRuleUpdateTargetById 944100 "!ARGS:q|!REQUEST_HEADERS:Referer"
+
+# Searches, and file, branch and tag names.
+# 930120: a search for package.json, or the commit graph of .gitignore
+SecRuleUpdateTargetById 930120 "!ARGS:q|!ARGS:file|!ARGS:template|!ARGS:body|\
+    !ARGS:refSubUrl|!ARGS:name|!ARGS:tag|!ARGS:rule_name"
+# 932160: a search for /bin/sh, or the API's contents of bin/docker-entrypoint
+SecRuleUpdateTargetById 932160 "!ARGS:q|!ARGS:file|!ARGS:template|!ARGS:body|\
+    !ARGS:refSubUrl|!ARGS:name|!ARGS:tag|!ARGS:rule_name"
+# 932260: a search for python3, or deleting the branch docker-build
+SecRuleUpdateTargetById 932260 "!ARGS:q|!ARGS:file|!ARGS:template|!ARGS:body|\
+    !ARGS:refSubUrl|!ARGS:name|!ARGS:tag|!ARGS:rule_name"
+
+# Searches, and file names in the query string.
+# 932120: a search for Invoke-WebRequest, or the commits of install-script.sh
+SecRuleUpdateTargetById 932120 "!ARGS:q|!ARGS:file|!ARGS:path|!ARGS:template|\
+    !ARGS:body|!ARGS:redirect_to"
+# 932130: a search for $(pwd), or an issue opened from the template [draft].md
+SecRuleUpdateTargetById 932130 "!ARGS:q|!ARGS:file|!ARGS:path|!ARGS:template|\
+    !ARGS:body|!ARGS:redirect_to"
+# 934100: a search for process.env, or the commits of process.env.d.ts
+SecRuleUpdateTargetById 934100 "!ARGS:q|!ARGS:file|!ARGS:path|!ARGS:template|\
+    !ARGS:body|!ARGS:redirect_to"
+# 934130: a search for __proto__, or the commits of __proto__.json
+SecRuleUpdateTargetById 934130 "!ARGS:q|!ARGS:file|!ARGS:path|!ARGS:template|\
+    !ARGS:body|!ARGS:redirect_to"
+# 941130: the commits of index.xhtml
+SecRuleUpdateTargetById 941130 "!ARGS:file|!ARGS:path|!ARGS:template|\
+    !ARGS:body|!ARGS:redirect_to"
+# 941180: a search for document.cookie, or the commits of document.write.js
+SecRuleUpdateTargetById 941180 "!ARGS:q|!ARGS:file|!ARGS:path|!ARGS:template|\
+    !ARGS:body|!ARGS:redirect_to"
+# 942140: the commits of information_schema.sql
+SecRuleUpdateTargetById 942140 "!ARGS:file|!ARGS:path|!ARGS:template|\
+    !ARGS:body|!ARGS:redirect_to"
+# 944110: a search for java.lang.Runtime, or the commits of Runtime.java
+SecRuleUpdateTargetById 944110 "!ARGS:q|!ARGS:file|!ARGS:path|!ARGS:template|\
+    !ARGS:body|!ARGS: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
+SecRuleUpdateTargetById 944130 "!ARGS:q|!ARGS:file|!ARGS:path|!ARGS:template|\
+    !ARGS:body|!ARGS:redirect_to|!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.
+# 934100: the page of process.env.d.ts
+SecRule REQUEST_FILENAME "@rx ^/(?:api/v1/repos/)?[^/]+/[^/]+/(?:src|raw|media|blame|commits|_edit|_delete|contents)/" \
+    "id:10001,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:10002,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:10003,phase:1,pass,nolog,ctl:ruleRemoveTargetById=944130;REQUEST_FILENAME"

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 +48,11 @@ 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, nor an
+  API call with a JSON body, nor a file saved through the API;
+- 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 +86,8 @@ 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 +157,51 @@ 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`. 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.
 
-### What it lets through
+gitea reads these as text to search for, or as names in a repository. 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 `SecRuleUpdateTargetById` line naming the field it
+   matched, as the file's other lines do. For a path, copy one of the file's
+   `SecRule REQUEST_FILENAME` rules and 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 these gitea requests:
 
-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:
+- the page of a file whose name ends in `~`, such as an editor's backup file.
+  Rule 920500 checks the path before any exclusion takes effect.
+- the page of a file in a directory named `...`, which reads as path traversal;
+- an artifact upload from `actions/upload-artifact@v3`, which sends the header
+  `Content-Range`. `actions/upload-artifact@v4` does not.
 
-- 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`.
+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 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 +192,10 @@ 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, loaded after the Core Rule Set. A
+  file that cannot be read or does not parse stops the start. So does a file
+  that names any number from 900000 to 900999. 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.
-	WAFMode             string
-	WAFParanoiaLevel    int
-	WAFAnomalyThreshold int
-	WAFDisabledRules    []int
-	WAFExemptPaths      []string
-	WAFBodyLimit        int64
+	// 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
@@ -523,8 +526,10 @@ func FromEnvironment(lookupEnv func(string) (string, bool)) (*Config, error) {
 		WAFAnomalyThreshold: env.numberOrOff("SWWAF_WAF_ANOMALY_THRESHOLD", "5"),
 		WAFDisabledRules: env.ruleIDs("SWWAF_WAF_DISABLED_RULES",
 			"920340,920420,920440,920640,930130,930140"),
-		WAFExemptPaths:       env.pathPrefixes("SWWAF_WAF_EXEMPT_PATHS", ""),
-		WAFBodyLimit:         env.wafBodyLimit("SWWAF_WAF_BODY_LIMIT", off),
+		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,
+				WAFDisabledRules:          []int{942100, 920350},
+				WAFExemptPaths:            []string{"/api/", "/static/"},
+				WAFBodyLimit:              32 << 10,
+				CoreRuleSetExclusionsFile: "/etc/smallwebwaf/crs-exclusions.conf",
 			},
 		},
 		{
@@ -565,7 +567,8 @@ func TestCoreRuleSetSettings(t *testing.T) {
 			WAFMode: cfg.WAFMode, WAFParanoiaLevel: cfg.WAFParanoiaLevel,
 			WAFAnomalyThreshold: cfg.WAFAnomalyThreshold,
 			WAFDisabledRules:    cfg.WAFDisabledRules, WAFExemptPaths: cfg.WAFExemptPaths,
-			WAFBodyLimit: cfg.WAFBodyLimit,
+			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 +206,29 @@ 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 {
+// 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.
+func NewCoreRuleSet(cfg *config.Config) (*waf.CoreRuleSet, error) {
 	if cfg.WAFMode == config.WAFModeOff {
-		return nil
+		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),
+		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
+	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

@@ -551,6 +551,29 @@ 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 TestLookupDatabaseReplacedWhileRunningTakesEffect(t *testing.T) {
 	t.Parallel()
 

internal/waf/testdata/gitea-requests.txt

@@ -0,0 +1,288 @@
+# Ordinary gitea requests, one path and query per line, that the Core Rule Set
+# must let through with deploy/gitea/crs-exclusions.conf. The tests of
+# internal/waf inspect each, and script/gitea-setup sends each to gitea through
+# the setup.
+
+# 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
+/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
+
+# 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
+
+# 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"
@@ -29,9 +33,9 @@ import (
 // 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.
+// 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
@@ -100,6 +104,13 @@ 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
@@ -160,8 +171,20 @@ 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 after the
+	// rest (SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE), "" while there is none.
+	ExclusionsFile string
 }
 
+// smallwebwafRuleID matches an id from 900000 to 900999, which an
+// exclusions file may not name: those are the ids of smallwebwaf's own
+// rules.
+var smallwebwafRuleID = regexp.MustCompile(`\b900\d{3}\b`)
+
+// 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")
+
 // CoreRuleSet is the Core Rule Set, ready to inspect requests. It is safe
 // for concurrent use.
 type CoreRuleSet struct {
@@ -169,9 +192,11 @@ 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
+// last. 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 {
@@ -189,9 +214,23 @@ func New(params Params) (*CoreRuleSet, error) {
 		text += "SecRuleRemoveById " + strings.Join(ids, " ") + "\n"
 	}
 
-	waf, err := coraza.NewWAF(coraza.NewWAFConfig().
-		WithRootFS(coreruleset.FS).
-		WithDirectives(text))
+	config := coraza.NewWAFConfig().WithRootFS(coreruleset.FS).WithDirectives(text)
+
+	if params.ExclusionsFile != "" {
+		exclusions, err := os.ReadFile(params.ExclusionsFile)
+		if err != nil {
+			return nil, fmt.Errorf("read the exclusions file: %w", err)
+		}
+
+		if id := smallwebwafRuleID.Find(exclusions); id != nil {
+			return nil, fmt.Errorf("the exclusions file names %s: %w", id,
+				errSmallwebwafRuleID)
+		}
+
+		config = config.WithDirectives(string(exclusions))
+	}
+
+	waf, err := coraza.NewWAF(config)
 	if err != nil {
 		return nil, fmt.Errorf("load the Core Rule Set: %w", err)
 	}

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 +363,126 @@ 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
+}
+
+func TestExclusionsFileIsLoadedAfterTheCoreRuleSet(t *testing.T) {
+	t.Parallel()
+
+	crs, err := withExclusions(exclusionsFile(t,
+		"SecRuleUpdateTargetById 942100 \"!ARGS:id\"\n"))
+	if err != nil {
+		t.Fatalf("load the exclusions: %v", err)
+	}
+
+	wantChange(t, crs, get("/?id=1'%20OR%20'1'='1"), get("/?q=1'%20OR%20'1'='1"),
+		matched(942100))
+}
+
+func TestExclusionsFileThatCannotBeUsedIsAnError(t *testing.T) {
+	t.Parallel()
+
+	for _, path := range []string{
+		filepath.Join(t.TempDir(), "missing.conf"),
+		exclusionsFile(t, "SecNoSuchDirective On\n"),
+		// smallwebwaf's own rules may not be switched off or changed.
+		exclusionsFile(t, "SecRuleRemoveById 900300\n"),
+		exclusionsFile(t, "SecRuleUpdateTargetById 900500 \"!ARGS:x\"\n"),
+	} {
+		_, err := withExclusions(path)
+		if err == nil {
+			t.Errorf("%s loaded", path)
+		}
+	}
+}
+
+// giteaRequests returns the targets of the recorded ordinary gitea requests
+// in testdata, which script/gitea-setup sends too.
+func giteaRequests(t *testing.T) []string {
+	t.Helper()
+
+	text, err := os.ReadFile(filepath.Join("testdata", "gitea-requests.txt"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var targets []string
+
+	for line := range strings.Lines(string(text)) {
+		line = strings.TrimSpace(line)
+		if line != "" && !strings.HasPrefix(line, "#") {
+			targets = append(targets, line)
+		}
+	}
+
+	return targets
+}
+
+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
+
+	// Each with the Referer of a page that names the same, as a page
+	// opened from it has.
+	for _, target := range giteaRequests(t) {
+		r := get(target, "Referer: http://git.example"+target)
+		if got := inspect(t, crs, r); got.Score >= threshold {
+			t.Errorf("%s refused: %+v", target, 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 +5,11 @@
 #     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, nor a fetch, nor API calls with
+#     JSON bodies;
+#   - 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 +141,65 @@ 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 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 $status"
+
+    grep -v -e '^#' -e '^$' "$ROOT/internal/waf/testdata/gitea-requests.txt" |
+        while IFS= read -r target; do
+            send "$target" --globoff --cookie "$WORK/cookies" \
+                --header "Referer: https://$SITE$target" >/dev/null
+            sleep 1
+        done
+
+    # The last request's report is logged once its answer has ended.
+    send /api/v1/settings/api >/dev/null
+    wait_for "servewaf logged no report of the last ordinary request" logged servewaf \
+        '"servewaf_line":"report"' '"path":"/api/v1/settings/api"'
+    refusals="$(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 +268,12 @@ 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 ] ||