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

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 ] ||